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Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/SemaExpr.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/SemaExpr.cpp | 10737 |
1 files changed, 10737 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaExpr.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaExpr.cpp new file mode 100644 index 0000000..20b92b8 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/SemaExpr.cpp @@ -0,0 +1,10737 @@ +//===--- SemaExpr.cpp - Semantic Analysis for Expressions -----------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is distributed under the University of Illinois Open Source +// License. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// +// +// This file implements semantic analysis for expressions. +// +//===----------------------------------------------------------------------===// + +#include "clang/Sema/SemaInternal.h" +#include "clang/Sema/Initialization.h" +#include "clang/Sema/Lookup.h" +#include "clang/Sema/AnalysisBasedWarnings.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/ASTMutationListener.h" +#include "clang/AST/CXXInheritance.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/DeclTemplate.h" +#include "clang/AST/EvaluatedExprVisitor.h" +#include "clang/AST/Expr.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/ExprObjC.h" +#include "clang/AST/RecursiveASTVisitor.h" +#include "clang/AST/TypeLoc.h" +#include "clang/Basic/PartialDiagnostic.h" +#include "clang/Basic/SourceManager.h" +#include "clang/Basic/TargetInfo.h" +#include "clang/Lex/LiteralSupport.h" +#include "clang/Lex/Preprocessor.h" +#include "clang/Sema/DeclSpec.h" +#include "clang/Sema/Designator.h" +#include "clang/Sema/Scope.h" +#include "clang/Sema/ScopeInfo.h" +#include "clang/Sema/ParsedTemplate.h" +#include "clang/Sema/Template.h" +using namespace clang; +using namespace sema; + + +/// \brief Determine whether the use of this declaration is valid, and +/// emit any corresponding diagnostics. +/// +/// This routine diagnoses various problems with referencing +/// declarations that can occur when using a declaration. For example, +/// it might warn if a deprecated or unavailable declaration is being +/// used, or produce an error (and return true) if a C++0x deleted +/// function is being used. +/// +/// If IgnoreDeprecated is set to true, this should not warn about deprecated +/// decls. +/// +/// \returns true if there was an error (this declaration cannot be +/// referenced), false otherwise. +/// +bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc, + const ObjCInterfaceDecl *UnknownObjCClass) { + if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) { + // If there were any diagnostics suppressed by template argument deduction, + // emit them now. + llvm::DenseMap<Decl *, llvm::SmallVector<PartialDiagnosticAt, 1> >::iterator + Pos = SuppressedDiagnostics.find(D->getCanonicalDecl()); + if (Pos != SuppressedDiagnostics.end()) { + llvm::SmallVectorImpl<PartialDiagnosticAt> &Suppressed = Pos->second; + for (unsigned I = 0, N = Suppressed.size(); I != N; ++I) + Diag(Suppressed[I].first, Suppressed[I].second); + + // Clear out the list of suppressed diagnostics, so that we don't emit + // them again for this specialization. However, we don't obsolete this + // entry from the table, because we want to avoid ever emitting these + // diagnostics again. + Suppressed.clear(); + } + } + + // See if this is an auto-typed variable whose initializer we are parsing. + if (ParsingInitForAutoVars.count(D)) { + Diag(Loc, diag::err_auto_variable_cannot_appear_in_own_initializer) + << D->getDeclName(); + return true; + } + + // See if this is a deleted function. + if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { + if (FD->isDeleted()) { + Diag(Loc, diag::err_deleted_function_use); + Diag(D->getLocation(), diag::note_unavailable_here) << true; + return true; + } + } + + // See if this declaration is unavailable or deprecated. + std::string Message; + switch (D->getAvailability(&Message)) { + case AR_Available: + case AR_NotYetIntroduced: + break; + + case AR_Deprecated: + EmitDeprecationWarning(D, Message, Loc, UnknownObjCClass); + break; + + case AR_Unavailable: + if (Message.empty()) { + if (!UnknownObjCClass) + Diag(Loc, diag::err_unavailable) << D->getDeclName(); + else + Diag(Loc, diag::warn_unavailable_fwdclass_message) + << D->getDeclName(); + } + else + Diag(Loc, diag::err_unavailable_message) + << D->getDeclName() << Message; + Diag(D->getLocation(), diag::note_unavailable_here) << 0; + break; + } + + // Warn if this is used but marked unused. + if (D->hasAttr<UnusedAttr>()) + Diag(Loc, diag::warn_used_but_marked_unused) << D->getDeclName(); + + return false; +} + +/// \brief Retrieve the message suffix that should be added to a +/// diagnostic complaining about the given function being deleted or +/// unavailable. +std::string Sema::getDeletedOrUnavailableSuffix(const FunctionDecl *FD) { + // FIXME: C++0x implicitly-deleted special member functions could be + // detected here so that we could improve diagnostics to say, e.g., + // "base class 'A' had a deleted copy constructor". + if (FD->isDeleted()) + return std::string(); + + std::string Message; + if (FD->getAvailability(&Message)) + return ": " + Message; + + return std::string(); +} + +/// DiagnoseSentinelCalls - This routine checks on method dispatch calls +/// (and other functions in future), which have been declared with sentinel +/// attribute. It warns if call does not have the sentinel argument. +/// +void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc, + Expr **Args, unsigned NumArgs) { + const SentinelAttr *attr = D->getAttr<SentinelAttr>(); + if (!attr) + return; + + // FIXME: In C++0x, if any of the arguments are parameter pack + // expansions, we can't check for the sentinel now. + int sentinelPos = attr->getSentinel(); + int nullPos = attr->getNullPos(); + + // FIXME. ObjCMethodDecl and FunctionDecl need be derived from the same common + // base class. Then we won't be needing two versions of the same code. + unsigned int i = 0; + bool warnNotEnoughArgs = false; + int isMethod = 0; + if (ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(D)) { + // skip over named parameters. + ObjCMethodDecl::param_iterator P, E = MD->param_end(); + for (P = MD->param_begin(); (P != E && i < NumArgs); ++P) { + if (nullPos) + --nullPos; + else + ++i; + } + warnNotEnoughArgs = (P != E || i >= NumArgs); + isMethod = 1; + } else if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D)) { + // skip over named parameters. + ObjCMethodDecl::param_iterator P, E = FD->param_end(); + for (P = FD->param_begin(); (P != E && i < NumArgs); ++P) { + if (nullPos) + --nullPos; + else + ++i; + } + warnNotEnoughArgs = (P != E || i >= NumArgs); + } else if (VarDecl *V = dyn_cast<VarDecl>(D)) { + // block or function pointer call. + QualType Ty = V->getType(); + if (Ty->isBlockPointerType() || Ty->isFunctionPointerType()) { + const FunctionType *FT = Ty->isFunctionPointerType() + ? Ty->getAs<PointerType>()->getPointeeType()->getAs<FunctionType>() + : Ty->getAs<BlockPointerType>()->getPointeeType()->getAs<FunctionType>(); + if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FT)) { + unsigned NumArgsInProto = Proto->getNumArgs(); + unsigned k; + for (k = 0; (k != NumArgsInProto && i < NumArgs); k++) { + if (nullPos) + --nullPos; + else + ++i; + } + warnNotEnoughArgs = (k != NumArgsInProto || i >= NumArgs); + } + if (Ty->isBlockPointerType()) + isMethod = 2; + } else + return; + } else + return; + + if (warnNotEnoughArgs) { + Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); + Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; + return; + } + int sentinel = i; + while (sentinelPos > 0 && i < NumArgs-1) { + --sentinelPos; + ++i; + } + if (sentinelPos > 0) { + Diag(Loc, diag::warn_not_enough_argument) << D->getDeclName(); + Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; + return; + } + while (i < NumArgs-1) { + ++i; + ++sentinel; + } + Expr *sentinelExpr = Args[sentinel]; + if (!sentinelExpr) return; + if (sentinelExpr->isTypeDependent()) return; + if (sentinelExpr->isValueDependent()) return; + + // nullptr_t is always treated as null. + if (sentinelExpr->getType()->isNullPtrType()) return; + + if (sentinelExpr->getType()->isAnyPointerType() && + sentinelExpr->IgnoreParenCasts()->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNull)) + return; + + // Unfortunately, __null has type 'int'. + if (isa<GNUNullExpr>(sentinelExpr)) return; + + Diag(Loc, diag::warn_missing_sentinel) << isMethod; + Diag(D->getLocation(), diag::note_sentinel_here) << isMethod; +} + +SourceRange Sema::getExprRange(ExprTy *E) const { + Expr *Ex = (Expr *)E; + return Ex? Ex->getSourceRange() : SourceRange(); +} + +//===----------------------------------------------------------------------===// +// Standard Promotions and Conversions +//===----------------------------------------------------------------------===// + +/// DefaultFunctionArrayConversion (C99 6.3.2.1p3, C99 6.3.2.1p4). +ExprResult Sema::DefaultFunctionArrayConversion(Expr *E) { + QualType Ty = E->getType(); + assert(!Ty.isNull() && "DefaultFunctionArrayConversion - missing type"); + + if (Ty->isFunctionType()) + E = ImpCastExprToType(E, Context.getPointerType(Ty), + CK_FunctionToPointerDecay).take(); + else if (Ty->isArrayType()) { + // In C90 mode, arrays only promote to pointers if the array expression is + // an lvalue. The relevant legalese is C90 6.2.2.1p3: "an lvalue that has + // type 'array of type' is converted to an expression that has type 'pointer + // to type'...". In C99 this was changed to: C99 6.3.2.1p3: "an expression + // that has type 'array of type' ...". The relevant change is "an lvalue" + // (C90) to "an expression" (C99). + // + // C++ 4.2p1: + // An lvalue or rvalue of type "array of N T" or "array of unknown bound of + // T" can be converted to an rvalue of type "pointer to T". + // + if (getLangOptions().C99 || getLangOptions().CPlusPlus || E->isLValue()) + E = ImpCastExprToType(E, Context.getArrayDecayedType(Ty), + CK_ArrayToPointerDecay).take(); + } + return Owned(E); +} + +static void CheckForNullPointerDereference(Sema &S, Expr *E) { + // Check to see if we are dereferencing a null pointer. If so, + // and if not volatile-qualified, this is undefined behavior that the + // optimizer will delete, so warn about it. People sometimes try to use this + // to get a deterministic trap and are surprised by clang's behavior. This + // only handles the pattern "*null", which is a very syntactic check. + if (UnaryOperator *UO = dyn_cast<UnaryOperator>(E->IgnoreParenCasts())) + if (UO->getOpcode() == UO_Deref && + UO->getSubExpr()->IgnoreParenCasts()-> + isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNotNull) && + !UO->getType().isVolatileQualified()) { + S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO, + S.PDiag(diag::warn_indirection_through_null) + << UO->getSubExpr()->getSourceRange()); + S.DiagRuntimeBehavior(UO->getOperatorLoc(), UO, + S.PDiag(diag::note_indirection_through_null)); + } +} + +ExprResult Sema::DefaultLvalueConversion(Expr *E) { + // C++ [conv.lval]p1: + // A glvalue of a non-function, non-array type T can be + // converted to a prvalue. + if (!E->isGLValue()) return Owned(E); + + QualType T = E->getType(); + assert(!T.isNull() && "r-value conversion on typeless expression?"); + + // Create a load out of an ObjCProperty l-value, if necessary. + if (E->getObjectKind() == OK_ObjCProperty) { + ExprResult Res = ConvertPropertyForRValue(E); + if (Res.isInvalid()) + return Owned(E); + E = Res.take(); + if (!E->isGLValue()) + return Owned(E); + } + + // We don't want to throw lvalue-to-rvalue casts on top of + // expressions of certain types in C++. + if (getLangOptions().CPlusPlus && + (E->getType() == Context.OverloadTy || + T->isDependentType() || + T->isRecordType())) + return Owned(E); + + // The C standard is actually really unclear on this point, and + // DR106 tells us what the result should be but not why. It's + // generally best to say that void types just doesn't undergo + // lvalue-to-rvalue at all. Note that expressions of unqualified + // 'void' type are never l-values, but qualified void can be. + if (T->isVoidType()) + return Owned(E); + + CheckForNullPointerDereference(*this, E); + + // C++ [conv.lval]p1: + // [...] If T is a non-class type, the type of the prvalue is the + // cv-unqualified version of T. Otherwise, the type of the + // rvalue is T. + // + // C99 6.3.2.1p2: + // If the lvalue has qualified type, the value has the unqualified + // version of the type of the lvalue; otherwise, the value has the + // type of the lvalue. + if (T.hasQualifiers()) + T = T.getUnqualifiedType(); + + CheckArrayAccess(E); + + return Owned(ImplicitCastExpr::Create(Context, T, CK_LValueToRValue, + E, 0, VK_RValue)); +} + +ExprResult Sema::DefaultFunctionArrayLvalueConversion(Expr *E) { + ExprResult Res = DefaultFunctionArrayConversion(E); + if (Res.isInvalid()) + return ExprError(); + Res = DefaultLvalueConversion(Res.take()); + if (Res.isInvalid()) + return ExprError(); + return move(Res); +} + + +/// UsualUnaryConversions - Performs various conversions that are common to most +/// operators (C99 6.3). The conversions of array and function types are +/// sometimes suppressed. For example, the array->pointer conversion doesn't +/// apply if the array is an argument to the sizeof or address (&) operators. +/// In these instances, this routine should *not* be called. +ExprResult Sema::UsualUnaryConversions(Expr *E) { + // First, convert to an r-value. + ExprResult Res = DefaultFunctionArrayLvalueConversion(E); + if (Res.isInvalid()) + return Owned(E); + E = Res.take(); + + QualType Ty = E->getType(); + assert(!Ty.isNull() && "UsualUnaryConversions - missing type"); + + // Try to perform integral promotions if the object has a theoretically + // promotable type. + if (Ty->isIntegralOrUnscopedEnumerationType()) { + // C99 6.3.1.1p2: + // + // The following may be used in an expression wherever an int or + // unsigned int may be used: + // - an object or expression with an integer type whose integer + // conversion rank is less than or equal to the rank of int + // and unsigned int. + // - A bit-field of type _Bool, int, signed int, or unsigned int. + // + // If an int can represent all values of the original type, the + // value is converted to an int; otherwise, it is converted to an + // unsigned int. These are called the integer promotions. All + // other types are unchanged by the integer promotions. + + QualType PTy = Context.isPromotableBitField(E); + if (!PTy.isNull()) { + E = ImpCastExprToType(E, PTy, CK_IntegralCast).take(); + return Owned(E); + } + if (Ty->isPromotableIntegerType()) { + QualType PT = Context.getPromotedIntegerType(Ty); + E = ImpCastExprToType(E, PT, CK_IntegralCast).take(); + return Owned(E); + } + } + return Owned(E); +} + +/// DefaultArgumentPromotion (C99 6.5.2.2p6). Used for function calls that +/// do not have a prototype. Arguments that have type float are promoted to +/// double. All other argument types are converted by UsualUnaryConversions(). +ExprResult Sema::DefaultArgumentPromotion(Expr *E) { + QualType Ty = E->getType(); + assert(!Ty.isNull() && "DefaultArgumentPromotion - missing type"); + + ExprResult Res = UsualUnaryConversions(E); + if (Res.isInvalid()) + return Owned(E); + E = Res.take(); + + // If this is a 'float' (CVR qualified or typedef) promote to double. + if (Ty->isSpecificBuiltinType(BuiltinType::Float)) + E = ImpCastExprToType(E, Context.DoubleTy, CK_FloatingCast).take(); + + return Owned(E); +} + +/// DefaultVariadicArgumentPromotion - Like DefaultArgumentPromotion, but +/// will warn if the resulting type is not a POD type, and rejects ObjC +/// interfaces passed by value. +ExprResult Sema::DefaultVariadicArgumentPromotion(Expr *E, VariadicCallType CT, + FunctionDecl *FDecl) { + ExprResult ExprRes = DefaultArgumentPromotion(E); + if (ExprRes.isInvalid()) + return ExprError(); + E = ExprRes.take(); + + // __builtin_va_start takes the second argument as a "varargs" argument, but + // it doesn't actually do anything with it. It doesn't need to be non-pod + // etc. + if (FDecl && FDecl->getBuiltinID() == Builtin::BI__builtin_va_start) + return Owned(E); + + if (E->getType()->isObjCObjectType() && + DiagRuntimeBehavior(E->getLocStart(), 0, + PDiag(diag::err_cannot_pass_objc_interface_to_vararg) + << E->getType() << CT)) + return ExprError(); + + if (!E->getType()->isPODType() && + DiagRuntimeBehavior(E->getLocStart(), 0, + PDiag(diag::warn_cannot_pass_non_pod_arg_to_vararg) + << E->getType() << CT)) + return ExprError(); + + return Owned(E); +} + +/// UsualArithmeticConversions - Performs various conversions that are common to +/// binary operators (C99 6.3.1.8). If both operands aren't arithmetic, this +/// routine returns the first non-arithmetic type found. The client is +/// responsible for emitting appropriate error diagnostics. +/// FIXME: verify the conversion rules for "complex int" are consistent with +/// GCC. +QualType Sema::UsualArithmeticConversions(ExprResult &lhsExpr, ExprResult &rhsExpr, + bool isCompAssign) { + if (!isCompAssign) { + lhsExpr = UsualUnaryConversions(lhsExpr.take()); + if (lhsExpr.isInvalid()) + return QualType(); + } + + rhsExpr = UsualUnaryConversions(rhsExpr.take()); + if (rhsExpr.isInvalid()) + return QualType(); + + // For conversion purposes, we ignore any qualifiers. + // For example, "const float" and "float" are equivalent. + QualType lhs = + Context.getCanonicalType(lhsExpr.get()->getType()).getUnqualifiedType(); + QualType rhs = + Context.getCanonicalType(rhsExpr.get()->getType()).getUnqualifiedType(); + + // If both types are identical, no conversion is needed. + if (lhs == rhs) + return lhs; + + // If either side is a non-arithmetic type (e.g. a pointer), we are done. + // The caller can deal with this (e.g. pointer + int). + if (!lhs->isArithmeticType() || !rhs->isArithmeticType()) + return lhs; + + // Apply unary and bitfield promotions to the LHS's type. + QualType lhs_unpromoted = lhs; + if (lhs->isPromotableIntegerType()) + lhs = Context.getPromotedIntegerType(lhs); + QualType LHSBitfieldPromoteTy = Context.isPromotableBitField(lhsExpr.get()); + if (!LHSBitfieldPromoteTy.isNull()) + lhs = LHSBitfieldPromoteTy; + if (lhs != lhs_unpromoted && !isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), lhs, CK_IntegralCast); + + // If both types are identical, no conversion is needed. + if (lhs == rhs) + return lhs; + + // At this point, we have two different arithmetic types. + + // Handle complex types first (C99 6.3.1.8p1). + bool LHSComplexFloat = lhs->isComplexType(); + bool RHSComplexFloat = rhs->isComplexType(); + if (LHSComplexFloat || RHSComplexFloat) { + // if we have an integer operand, the result is the complex type. + + if (!RHSComplexFloat && !rhs->isRealFloatingType()) { + if (rhs->isIntegerType()) { + QualType fp = cast<ComplexType>(lhs)->getElementType(); + rhsExpr = ImpCastExprToType(rhsExpr.take(), fp, CK_IntegralToFloating); + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_FloatingRealToComplex); + } else { + assert(rhs->isComplexIntegerType()); + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_IntegralComplexToFloatingComplex); + } + return lhs; + } + + if (!LHSComplexFloat && !lhs->isRealFloatingType()) { + if (!isCompAssign) { + // int -> float -> _Complex float + if (lhs->isIntegerType()) { + QualType fp = cast<ComplexType>(rhs)->getElementType(); + lhsExpr = ImpCastExprToType(lhsExpr.take(), fp, CK_IntegralToFloating); + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_FloatingRealToComplex); + } else { + assert(lhs->isComplexIntegerType()); + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_IntegralComplexToFloatingComplex); + } + } + return rhs; + } + + // This handles complex/complex, complex/float, or float/complex. + // When both operands are complex, the shorter operand is converted to the + // type of the longer, and that is the type of the result. This corresponds + // to what is done when combining two real floating-point operands. + // The fun begins when size promotion occur across type domains. + // From H&S 6.3.4: When one operand is complex and the other is a real + // floating-point type, the less precise type is converted, within it's + // real or complex domain, to the precision of the other type. For example, + // when combining a "long double" with a "double _Complex", the + // "double _Complex" is promoted to "long double _Complex". + int order = Context.getFloatingTypeOrder(lhs, rhs); + + // If both are complex, just cast to the more precise type. + if (LHSComplexFloat && RHSComplexFloat) { + if (order > 0) { + // _Complex float -> _Complex double + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_FloatingComplexCast); + return lhs; + + } else if (order < 0) { + // _Complex float -> _Complex double + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_FloatingComplexCast); + return rhs; + } + return lhs; + } + + // If just the LHS is complex, the RHS needs to be converted, + // and the LHS might need to be promoted. + if (LHSComplexFloat) { + if (order > 0) { // LHS is wider + // float -> _Complex double + QualType fp = cast<ComplexType>(lhs)->getElementType(); + rhsExpr = ImpCastExprToType(rhsExpr.take(), fp, CK_FloatingCast); + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_FloatingRealToComplex); + return lhs; + } + + // RHS is at least as wide. Find its corresponding complex type. + QualType result = (order == 0 ? lhs : Context.getComplexType(rhs)); + + // double -> _Complex double + rhsExpr = ImpCastExprToType(rhsExpr.take(), result, CK_FloatingRealToComplex); + + // _Complex float -> _Complex double + if (!isCompAssign && order < 0) + lhsExpr = ImpCastExprToType(lhsExpr.take(), result, CK_FloatingComplexCast); + + return result; + } + + // Just the RHS is complex, so the LHS needs to be converted + // and the RHS might need to be promoted. + assert(RHSComplexFloat); + + if (order < 0) { // RHS is wider + // float -> _Complex double + if (!isCompAssign) { + QualType fp = cast<ComplexType>(rhs)->getElementType(); + lhsExpr = ImpCastExprToType(lhsExpr.take(), fp, CK_FloatingCast); + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_FloatingRealToComplex); + } + return rhs; + } + + // LHS is at least as wide. Find its corresponding complex type. + QualType result = (order == 0 ? rhs : Context.getComplexType(lhs)); + + // double -> _Complex double + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), result, CK_FloatingRealToComplex); + + // _Complex float -> _Complex double + if (order > 0) + rhsExpr = ImpCastExprToType(rhsExpr.take(), result, CK_FloatingComplexCast); + + return result; + } + + // Now handle "real" floating types (i.e. float, double, long double). + bool LHSFloat = lhs->isRealFloatingType(); + bool RHSFloat = rhs->isRealFloatingType(); + if (LHSFloat || RHSFloat) { + // If we have two real floating types, convert the smaller operand + // to the bigger result. + if (LHSFloat && RHSFloat) { + int order = Context.getFloatingTypeOrder(lhs, rhs); + if (order > 0) { + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_FloatingCast); + return lhs; + } + + assert(order < 0 && "illegal float comparison"); + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_FloatingCast); + return rhs; + } + + // If we have an integer operand, the result is the real floating type. + if (LHSFloat) { + if (rhs->isIntegerType()) { + // Convert rhs to the lhs floating point type. + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_IntegralToFloating); + return lhs; + } + + // Convert both sides to the appropriate complex float. + assert(rhs->isComplexIntegerType()); + QualType result = Context.getComplexType(lhs); + + // _Complex int -> _Complex float + rhsExpr = ImpCastExprToType(rhsExpr.take(), result, CK_IntegralComplexToFloatingComplex); + + // float -> _Complex float + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), result, CK_FloatingRealToComplex); + + return result; + } + + assert(RHSFloat); + if (lhs->isIntegerType()) { + // Convert lhs to the rhs floating point type. + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_IntegralToFloating); + return rhs; + } + + // Convert both sides to the appropriate complex float. + assert(lhs->isComplexIntegerType()); + QualType result = Context.getComplexType(rhs); + + // _Complex int -> _Complex float + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), result, CK_IntegralComplexToFloatingComplex); + + // float -> _Complex float + rhsExpr = ImpCastExprToType(rhsExpr.take(), result, CK_FloatingRealToComplex); + + return result; + } + + // Handle GCC complex int extension. + // FIXME: if the operands are (int, _Complex long), we currently + // don't promote the complex. Also, signedness? + const ComplexType *lhsComplexInt = lhs->getAsComplexIntegerType(); + const ComplexType *rhsComplexInt = rhs->getAsComplexIntegerType(); + if (lhsComplexInt && rhsComplexInt) { + int order = Context.getIntegerTypeOrder(lhsComplexInt->getElementType(), + rhsComplexInt->getElementType()); + assert(order && "inequal types with equal element ordering"); + if (order > 0) { + // _Complex int -> _Complex long + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_IntegralComplexCast); + return lhs; + } + + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_IntegralComplexCast); + return rhs; + } else if (lhsComplexInt) { + // int -> _Complex int + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_IntegralRealToComplex); + return lhs; + } else if (rhsComplexInt) { + // int -> _Complex int + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_IntegralRealToComplex); + return rhs; + } + + // Finally, we have two differing integer types. + // The rules for this case are in C99 6.3.1.8 + int compare = Context.getIntegerTypeOrder(lhs, rhs); + bool lhsSigned = lhs->hasSignedIntegerRepresentation(), + rhsSigned = rhs->hasSignedIntegerRepresentation(); + if (lhsSigned == rhsSigned) { + // Same signedness; use the higher-ranked type + if (compare >= 0) { + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_IntegralCast); + return lhs; + } else if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_IntegralCast); + return rhs; + } else if (compare != (lhsSigned ? 1 : -1)) { + // The unsigned type has greater than or equal rank to the + // signed type, so use the unsigned type + if (rhsSigned) { + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_IntegralCast); + return lhs; + } else if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_IntegralCast); + return rhs; + } else if (Context.getIntWidth(lhs) != Context.getIntWidth(rhs)) { + // The two types are different widths; if we are here, that + // means the signed type is larger than the unsigned type, so + // use the signed type. + if (lhsSigned) { + rhsExpr = ImpCastExprToType(rhsExpr.take(), lhs, CK_IntegralCast); + return lhs; + } else if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), rhs, CK_IntegralCast); + return rhs; + } else { + // The signed type is higher-ranked than the unsigned type, + // but isn't actually any bigger (like unsigned int and long + // on most 32-bit systems). Use the unsigned type corresponding + // to the signed type. + QualType result = + Context.getCorrespondingUnsignedType(lhsSigned ? lhs : rhs); + rhsExpr = ImpCastExprToType(rhsExpr.take(), result, CK_IntegralCast); + if (!isCompAssign) + lhsExpr = ImpCastExprToType(lhsExpr.take(), result, CK_IntegralCast); + return result; + } +} + +//===----------------------------------------------------------------------===// +// Semantic Analysis for various Expression Types +//===----------------------------------------------------------------------===// + + +ExprResult +Sema::ActOnGenericSelectionExpr(SourceLocation KeyLoc, + SourceLocation DefaultLoc, + SourceLocation RParenLoc, + Expr *ControllingExpr, + MultiTypeArg types, + MultiExprArg exprs) { + unsigned NumAssocs = types.size(); + assert(NumAssocs == exprs.size()); + + ParsedType *ParsedTypes = types.release(); + Expr **Exprs = exprs.release(); + + TypeSourceInfo **Types = new TypeSourceInfo*[NumAssocs]; + for (unsigned i = 0; i < NumAssocs; ++i) { + if (ParsedTypes[i]) + (void) GetTypeFromParser(ParsedTypes[i], &Types[i]); + else + Types[i] = 0; + } + + ExprResult ER = CreateGenericSelectionExpr(KeyLoc, DefaultLoc, RParenLoc, + ControllingExpr, Types, Exprs, + NumAssocs); + delete [] Types; + return ER; +} + +ExprResult +Sema::CreateGenericSelectionExpr(SourceLocation KeyLoc, + SourceLocation DefaultLoc, + SourceLocation RParenLoc, + Expr *ControllingExpr, + TypeSourceInfo **Types, + Expr **Exprs, + unsigned NumAssocs) { + bool TypeErrorFound = false, + IsResultDependent = ControllingExpr->isTypeDependent(), + ContainsUnexpandedParameterPack + = ControllingExpr->containsUnexpandedParameterPack(); + + for (unsigned i = 0; i < NumAssocs; ++i) { + if (Exprs[i]->containsUnexpandedParameterPack()) + ContainsUnexpandedParameterPack = true; + + if (Types[i]) { + if (Types[i]->getType()->containsUnexpandedParameterPack()) + ContainsUnexpandedParameterPack = true; + + if (Types[i]->getType()->isDependentType()) { + IsResultDependent = true; + } else { + // C1X 6.5.1.1p2 "The type name in a generic association shall specify a + // complete object type other than a variably modified type." + unsigned D = 0; + if (Types[i]->getType()->isIncompleteType()) + D = diag::err_assoc_type_incomplete; + else if (!Types[i]->getType()->isObjectType()) + D = diag::err_assoc_type_nonobject; + else if (Types[i]->getType()->isVariablyModifiedType()) + D = diag::err_assoc_type_variably_modified; + + if (D != 0) { + Diag(Types[i]->getTypeLoc().getBeginLoc(), D) + << Types[i]->getTypeLoc().getSourceRange() + << Types[i]->getType(); + TypeErrorFound = true; + } + + // C1X 6.5.1.1p2 "No two generic associations in the same generic + // selection shall specify compatible types." + for (unsigned j = i+1; j < NumAssocs; ++j) + if (Types[j] && !Types[j]->getType()->isDependentType() && + Context.typesAreCompatible(Types[i]->getType(), + Types[j]->getType())) { + Diag(Types[j]->getTypeLoc().getBeginLoc(), + diag::err_assoc_compatible_types) + << Types[j]->getTypeLoc().getSourceRange() + << Types[j]->getType() + << Types[i]->getType(); + Diag(Types[i]->getTypeLoc().getBeginLoc(), + diag::note_compat_assoc) + << Types[i]->getTypeLoc().getSourceRange() + << Types[i]->getType(); + TypeErrorFound = true; + } + } + } + } + if (TypeErrorFound) + return ExprError(); + + // If we determined that the generic selection is result-dependent, don't + // try to compute the result expression. + if (IsResultDependent) + return Owned(new (Context) GenericSelectionExpr( + Context, KeyLoc, ControllingExpr, + Types, Exprs, NumAssocs, DefaultLoc, + RParenLoc, ContainsUnexpandedParameterPack)); + + llvm::SmallVector<unsigned, 1> CompatIndices; + unsigned DefaultIndex = -1U; + for (unsigned i = 0; i < NumAssocs; ++i) { + if (!Types[i]) + DefaultIndex = i; + else if (Context.typesAreCompatible(ControllingExpr->getType(), + Types[i]->getType())) + CompatIndices.push_back(i); + } + + // C1X 6.5.1.1p2 "The controlling expression of a generic selection shall have + // type compatible with at most one of the types named in its generic + // association list." + if (CompatIndices.size() > 1) { + // We strip parens here because the controlling expression is typically + // parenthesized in macro definitions. + ControllingExpr = ControllingExpr->IgnoreParens(); + Diag(ControllingExpr->getLocStart(), diag::err_generic_sel_multi_match) + << ControllingExpr->getSourceRange() << ControllingExpr->getType() + << (unsigned) CompatIndices.size(); + for (llvm::SmallVector<unsigned, 1>::iterator I = CompatIndices.begin(), + E = CompatIndices.end(); I != E; ++I) { + Diag(Types[*I]->getTypeLoc().getBeginLoc(), + diag::note_compat_assoc) + << Types[*I]->getTypeLoc().getSourceRange() + << Types[*I]->getType(); + } + return ExprError(); + } + + // C1X 6.5.1.1p2 "If a generic selection has no default generic association, + // its controlling expression shall have type compatible with exactly one of + // the types named in its generic association list." + if (DefaultIndex == -1U && CompatIndices.size() == 0) { + // We strip parens here because the controlling expression is typically + // parenthesized in macro definitions. + ControllingExpr = ControllingExpr->IgnoreParens(); + Diag(ControllingExpr->getLocStart(), diag::err_generic_sel_no_match) + << ControllingExpr->getSourceRange() << ControllingExpr->getType(); + return ExprError(); + } + + // C1X 6.5.1.1p3 "If a generic selection has a generic association with a + // type name that is compatible with the type of the controlling expression, + // then the result expression of the generic selection is the expression + // in that generic association. Otherwise, the result expression of the + // generic selection is the expression in the default generic association." + unsigned ResultIndex = + CompatIndices.size() ? CompatIndices[0] : DefaultIndex; + + return Owned(new (Context) GenericSelectionExpr( + Context, KeyLoc, ControllingExpr, + Types, Exprs, NumAssocs, DefaultLoc, + RParenLoc, ContainsUnexpandedParameterPack, + ResultIndex)); +} + +/// ActOnStringLiteral - The specified tokens were lexed as pasted string +/// fragments (e.g. "foo" "bar" L"baz"). The result string has to handle string +/// concatenation ([C99 5.1.1.2, translation phase #6]), so it may come from +/// multiple tokens. However, the common case is that StringToks points to one +/// string. +/// +ExprResult +Sema::ActOnStringLiteral(const Token *StringToks, unsigned NumStringToks) { + assert(NumStringToks && "Must have at least one string!"); + + StringLiteralParser Literal(StringToks, NumStringToks, PP); + if (Literal.hadError) + return ExprError(); + + llvm::SmallVector<SourceLocation, 4> StringTokLocs; + for (unsigned i = 0; i != NumStringToks; ++i) + StringTokLocs.push_back(StringToks[i].getLocation()); + + QualType StrTy = Context.CharTy; + if (Literal.AnyWide) + StrTy = Context.getWCharType(); + else if (Literal.Pascal) + StrTy = Context.UnsignedCharTy; + + // A C++ string literal has a const-qualified element type (C++ 2.13.4p1). + if (getLangOptions().CPlusPlus || getLangOptions().ConstStrings) + StrTy.addConst(); + + // Get an array type for the string, according to C99 6.4.5. This includes + // the nul terminator character as well as the string length for pascal + // strings. + StrTy = Context.getConstantArrayType(StrTy, + llvm::APInt(32, Literal.GetNumStringChars()+1), + ArrayType::Normal, 0); + + // Pass &StringTokLocs[0], StringTokLocs.size() to factory! + return Owned(StringLiteral::Create(Context, Literal.GetString(), + Literal.GetStringLength(), + Literal.AnyWide, Literal.Pascal, StrTy, + &StringTokLocs[0], + StringTokLocs.size())); +} + +enum CaptureResult { + /// No capture is required. + CR_NoCapture, + + /// A capture is required. + CR_Capture, + + /// A by-ref capture is required. + CR_CaptureByRef, + + /// An error occurred when trying to capture the given variable. + CR_Error +}; + +/// Diagnose an uncapturable value reference. +/// +/// \param var - the variable referenced +/// \param DC - the context which we couldn't capture through +static CaptureResult +diagnoseUncapturableValueReference(Sema &S, SourceLocation loc, + VarDecl *var, DeclContext *DC) { + switch (S.ExprEvalContexts.back().Context) { + case Sema::Unevaluated: + // The argument will never be evaluated, so don't complain. + return CR_NoCapture; + + case Sema::PotentiallyEvaluated: + case Sema::PotentiallyEvaluatedIfUsed: + break; + + case Sema::PotentiallyPotentiallyEvaluated: + // FIXME: delay these! + break; + } + + // Don't diagnose about capture if we're not actually in code right + // now; in general, there are more appropriate places that will + // diagnose this. + if (!S.CurContext->isFunctionOrMethod()) return CR_NoCapture; + + // Certain madnesses can happen with parameter declarations, which + // we want to ignore. + if (isa<ParmVarDecl>(var)) { + // - If the parameter still belongs to the translation unit, then + // we're actually just using one parameter in the declaration of + // the next. This is useful in e.g. VLAs. + if (isa<TranslationUnitDecl>(var->getDeclContext())) + return CR_NoCapture; + + // - This particular madness can happen in ill-formed default + // arguments; claim it's okay and let downstream code handle it. + if (S.CurContext == var->getDeclContext()->getParent()) + return CR_NoCapture; + } + + DeclarationName functionName; + if (FunctionDecl *fn = dyn_cast<FunctionDecl>(var->getDeclContext())) + functionName = fn->getDeclName(); + // FIXME: variable from enclosing block that we couldn't capture from! + + S.Diag(loc, diag::err_reference_to_local_var_in_enclosing_function) + << var->getIdentifier() << functionName; + S.Diag(var->getLocation(), diag::note_local_variable_declared_here) + << var->getIdentifier(); + + return CR_Error; +} + +/// There is a well-formed capture at a particular scope level; +/// propagate it through all the nested blocks. +static CaptureResult propagateCapture(Sema &S, unsigned validScopeIndex, + const BlockDecl::Capture &capture) { + VarDecl *var = capture.getVariable(); + + // Update all the inner blocks with the capture information. + for (unsigned i = validScopeIndex + 1, e = S.FunctionScopes.size(); + i != e; ++i) { + BlockScopeInfo *innerBlock = cast<BlockScopeInfo>(S.FunctionScopes[i]); + innerBlock->Captures.push_back( + BlockDecl::Capture(capture.getVariable(), capture.isByRef(), + /*nested*/ true, capture.getCopyExpr())); + innerBlock->CaptureMap[var] = innerBlock->Captures.size(); // +1 + } + + return capture.isByRef() ? CR_CaptureByRef : CR_Capture; +} + +/// shouldCaptureValueReference - Determine if a reference to the +/// given value in the current context requires a variable capture. +/// +/// This also keeps the captures set in the BlockScopeInfo records +/// up-to-date. +static CaptureResult shouldCaptureValueReference(Sema &S, SourceLocation loc, + ValueDecl *value) { + // Only variables ever require capture. + VarDecl *var = dyn_cast<VarDecl>(value); + if (!var) return CR_NoCapture; + + // Fast path: variables from the current context never require capture. + DeclContext *DC = S.CurContext; + if (var->getDeclContext() == DC) return CR_NoCapture; + + // Only variables with local storage require capture. + // FIXME: What about 'const' variables in C++? + if (!var->hasLocalStorage()) return CR_NoCapture; + + // Otherwise, we need to capture. + + unsigned functionScopesIndex = S.FunctionScopes.size() - 1; + do { + // Only blocks (and eventually C++0x closures) can capture; other + // scopes don't work. + if (!isa<BlockDecl>(DC)) + return diagnoseUncapturableValueReference(S, loc, var, DC); + + BlockScopeInfo *blockScope = + cast<BlockScopeInfo>(S.FunctionScopes[functionScopesIndex]); + assert(blockScope->TheDecl == static_cast<BlockDecl*>(DC)); + + // Check whether we've already captured it in this block. If so, + // we're done. + if (unsigned indexPlus1 = blockScope->CaptureMap[var]) + return propagateCapture(S, functionScopesIndex, + blockScope->Captures[indexPlus1 - 1]); + + functionScopesIndex--; + DC = cast<BlockDecl>(DC)->getDeclContext(); + } while (var->getDeclContext() != DC); + + // Okay, we descended all the way to the block that defines the variable. + // Actually try to capture it. + QualType type = var->getType(); + + // Prohibit variably-modified types. + if (type->isVariablyModifiedType()) { + S.Diag(loc, diag::err_ref_vm_type); + S.Diag(var->getLocation(), diag::note_declared_at); + return CR_Error; + } + + // Prohibit arrays, even in __block variables, but not references to + // them. + if (type->isArrayType()) { + S.Diag(loc, diag::err_ref_array_type); + S.Diag(var->getLocation(), diag::note_declared_at); + return CR_Error; + } + + S.MarkDeclarationReferenced(loc, var); + + // The BlocksAttr indicates the variable is bound by-reference. + bool byRef = var->hasAttr<BlocksAttr>(); + + // Build a copy expression. + Expr *copyExpr = 0; + const RecordType *rtype; + if (!byRef && S.getLangOptions().CPlusPlus && !type->isDependentType() && + (rtype = type->getAs<RecordType>())) { + + // The capture logic needs the destructor, so make sure we mark it. + // Usually this is unnecessary because most local variables have + // their destructors marked at declaration time, but parameters are + // an exception because it's technically only the call site that + // actually requires the destructor. + if (isa<ParmVarDecl>(var)) + S.FinalizeVarWithDestructor(var, rtype); + + // According to the blocks spec, the capture of a variable from + // the stack requires a const copy constructor. This is not true + // of the copy/move done to move a __block variable to the heap. + type.addConst(); + + Expr *declRef = new (S.Context) DeclRefExpr(var, type, VK_LValue, loc); + ExprResult result = + S.PerformCopyInitialization( + InitializedEntity::InitializeBlock(var->getLocation(), + type, false), + loc, S.Owned(declRef)); + + // Build a full-expression copy expression if initialization + // succeeded and used a non-trivial constructor. Recover from + // errors by pretending that the copy isn't necessary. + if (!result.isInvalid() && + !cast<CXXConstructExpr>(result.get())->getConstructor()->isTrivial()) { + result = S.MaybeCreateExprWithCleanups(result); + copyExpr = result.take(); + } + } + + // We're currently at the declarer; go back to the closure. + functionScopesIndex++; + BlockScopeInfo *blockScope = + cast<BlockScopeInfo>(S.FunctionScopes[functionScopesIndex]); + + // Build a valid capture in this scope. + blockScope->Captures.push_back( + BlockDecl::Capture(var, byRef, /*nested*/ false, copyExpr)); + blockScope->CaptureMap[var] = blockScope->Captures.size(); // +1 + + // Propagate that to inner captures if necessary. + return propagateCapture(S, functionScopesIndex, + blockScope->Captures.back()); +} + +static ExprResult BuildBlockDeclRefExpr(Sema &S, ValueDecl *vd, + const DeclarationNameInfo &NameInfo, + bool byRef) { + assert(isa<VarDecl>(vd) && "capturing non-variable"); + + VarDecl *var = cast<VarDecl>(vd); + assert(var->hasLocalStorage() && "capturing non-local"); + assert(byRef == var->hasAttr<BlocksAttr>() && "byref set wrong"); + + QualType exprType = var->getType().getNonReferenceType(); + + BlockDeclRefExpr *BDRE; + if (!byRef) { + // The variable will be bound by copy; make it const within the + // closure, but record that this was done in the expression. + bool constAdded = !exprType.isConstQualified(); + exprType.addConst(); + + BDRE = new (S.Context) BlockDeclRefExpr(var, exprType, VK_LValue, + NameInfo.getLoc(), false, + constAdded); + } else { + BDRE = new (S.Context) BlockDeclRefExpr(var, exprType, VK_LValue, + NameInfo.getLoc(), true); + } + + return S.Owned(BDRE); +} + +ExprResult +Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, + SourceLocation Loc, + const CXXScopeSpec *SS) { + DeclarationNameInfo NameInfo(D->getDeclName(), Loc); + return BuildDeclRefExpr(D, Ty, VK, NameInfo, SS); +} + +/// BuildDeclRefExpr - Build an expression that references a +/// declaration that does not require a closure capture. +ExprResult +Sema::BuildDeclRefExpr(ValueDecl *D, QualType Ty, ExprValueKind VK, + const DeclarationNameInfo &NameInfo, + const CXXScopeSpec *SS) { + MarkDeclarationReferenced(NameInfo.getLoc(), D); + + Expr *E = DeclRefExpr::Create(Context, + SS? SS->getWithLocInContext(Context) + : NestedNameSpecifierLoc(), + D, NameInfo, Ty, VK); + + // Just in case we're building an illegal pointer-to-member. + if (isa<FieldDecl>(D) && cast<FieldDecl>(D)->getBitWidth()) + E->setObjectKind(OK_BitField); + + return Owned(E); +} + +static ExprResult +BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow, + const CXXScopeSpec &SS, FieldDecl *Field, + DeclAccessPair FoundDecl, + const DeclarationNameInfo &MemberNameInfo); + +ExprResult +Sema::BuildAnonymousStructUnionMemberReference(const CXXScopeSpec &SS, + SourceLocation loc, + IndirectFieldDecl *indirectField, + Expr *baseObjectExpr, + SourceLocation opLoc) { + // First, build the expression that refers to the base object. + + bool baseObjectIsPointer = false; + Qualifiers baseQuals; + + // Case 1: the base of the indirect field is not a field. + VarDecl *baseVariable = indirectField->getVarDecl(); + CXXScopeSpec EmptySS; + if (baseVariable) { + assert(baseVariable->getType()->isRecordType()); + + // In principle we could have a member access expression that + // accesses an anonymous struct/union that's a static member of + // the base object's class. However, under the current standard, + // static data members cannot be anonymous structs or unions. + // Supporting this is as easy as building a MemberExpr here. + assert(!baseObjectExpr && "anonymous struct/union is static data member?"); + + DeclarationNameInfo baseNameInfo(DeclarationName(), loc); + + ExprResult result = + BuildDeclarationNameExpr(EmptySS, baseNameInfo, baseVariable); + if (result.isInvalid()) return ExprError(); + + baseObjectExpr = result.take(); + baseObjectIsPointer = false; + baseQuals = baseObjectExpr->getType().getQualifiers(); + + // Case 2: the base of the indirect field is a field and the user + // wrote a member expression. + } else if (baseObjectExpr) { + // The caller provided the base object expression. Determine + // whether its a pointer and whether it adds any qualifiers to the + // anonymous struct/union fields we're looking into. + QualType objectType = baseObjectExpr->getType(); + + if (const PointerType *ptr = objectType->getAs<PointerType>()) { + baseObjectIsPointer = true; + objectType = ptr->getPointeeType(); + } else { + baseObjectIsPointer = false; + } + baseQuals = objectType.getQualifiers(); + + // Case 3: the base of the indirect field is a field and we should + // build an implicit member access. + } else { + // We've found a member of an anonymous struct/union that is + // inside a non-anonymous struct/union, so in a well-formed + // program our base object expression is "this". + CXXMethodDecl *method = tryCaptureCXXThis(); + if (!method) { + Diag(loc, diag::err_invalid_member_use_in_static_method) + << indirectField->getDeclName(); + return ExprError(); + } + + // Our base object expression is "this". + baseObjectExpr = + new (Context) CXXThisExpr(loc, method->getThisType(Context), + /*isImplicit=*/ true); + baseObjectIsPointer = true; + baseQuals = Qualifiers::fromCVRMask(method->getTypeQualifiers()); + } + + // Build the implicit member references to the field of the + // anonymous struct/union. + Expr *result = baseObjectExpr; + IndirectFieldDecl::chain_iterator + FI = indirectField->chain_begin(), FEnd = indirectField->chain_end(); + + // Build the first member access in the chain with full information. + if (!baseVariable) { + FieldDecl *field = cast<FieldDecl>(*FI); + + // FIXME: use the real found-decl info! + DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess()); + + // Make a nameInfo that properly uses the anonymous name. + DeclarationNameInfo memberNameInfo(field->getDeclName(), loc); + + result = BuildFieldReferenceExpr(*this, result, baseObjectIsPointer, + EmptySS, field, foundDecl, + memberNameInfo).take(); + baseObjectIsPointer = false; + + // FIXME: check qualified member access + } + + // In all cases, we should now skip the first declaration in the chain. + ++FI; + + while (FI != FEnd) { + FieldDecl *field = cast<FieldDecl>(*FI++); + + // FIXME: these are somewhat meaningless + DeclarationNameInfo memberNameInfo(field->getDeclName(), loc); + DeclAccessPair foundDecl = DeclAccessPair::make(field, field->getAccess()); + + result = BuildFieldReferenceExpr(*this, result, /*isarrow*/ false, + (FI == FEnd? SS : EmptySS), field, + foundDecl, memberNameInfo) + .take(); + } + + return Owned(result); +} + +/// Decomposes the given name into a DeclarationNameInfo, its location, and +/// possibly a list of template arguments. +/// +/// If this produces template arguments, it is permitted to call +/// DecomposeTemplateName. +/// +/// This actually loses a lot of source location information for +/// non-standard name kinds; we should consider preserving that in +/// some way. +static void DecomposeUnqualifiedId(Sema &SemaRef, + const UnqualifiedId &Id, + TemplateArgumentListInfo &Buffer, + DeclarationNameInfo &NameInfo, + const TemplateArgumentListInfo *&TemplateArgs) { + if (Id.getKind() == UnqualifiedId::IK_TemplateId) { + Buffer.setLAngleLoc(Id.TemplateId->LAngleLoc); + Buffer.setRAngleLoc(Id.TemplateId->RAngleLoc); + + ASTTemplateArgsPtr TemplateArgsPtr(SemaRef, + Id.TemplateId->getTemplateArgs(), + Id.TemplateId->NumArgs); + SemaRef.translateTemplateArguments(TemplateArgsPtr, Buffer); + TemplateArgsPtr.release(); + + TemplateName TName = Id.TemplateId->Template.get(); + SourceLocation TNameLoc = Id.TemplateId->TemplateNameLoc; + NameInfo = SemaRef.Context.getNameForTemplate(TName, TNameLoc); + TemplateArgs = &Buffer; + } else { + NameInfo = SemaRef.GetNameFromUnqualifiedId(Id); + TemplateArgs = 0; + } +} + +/// Determines if the given class is provably not derived from all of +/// the prospective base classes. +static bool IsProvablyNotDerivedFrom(Sema &SemaRef, + CXXRecordDecl *Record, + const llvm::SmallPtrSet<CXXRecordDecl*, 4> &Bases) { + if (Bases.count(Record->getCanonicalDecl())) + return false; + + RecordDecl *RD = Record->getDefinition(); + if (!RD) return false; + Record = cast<CXXRecordDecl>(RD); + + for (CXXRecordDecl::base_class_iterator I = Record->bases_begin(), + E = Record->bases_end(); I != E; ++I) { + CanQualType BaseT = SemaRef.Context.getCanonicalType((*I).getType()); + CanQual<RecordType> BaseRT = BaseT->getAs<RecordType>(); + if (!BaseRT) return false; + + CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); + if (!IsProvablyNotDerivedFrom(SemaRef, BaseRecord, Bases)) + return false; + } + + return true; +} + +enum IMAKind { + /// The reference is definitely not an instance member access. + IMA_Static, + + /// The reference may be an implicit instance member access. + IMA_Mixed, + + /// The reference may be to an instance member, but it is invalid if + /// so, because the context is not an instance method. + IMA_Mixed_StaticContext, + + /// The reference may be to an instance member, but it is invalid if + /// so, because the context is from an unrelated class. + IMA_Mixed_Unrelated, + + /// The reference is definitely an implicit instance member access. + IMA_Instance, + + /// The reference may be to an unresolved using declaration. + IMA_Unresolved, + + /// The reference may be to an unresolved using declaration and the + /// context is not an instance method. + IMA_Unresolved_StaticContext, + + /// All possible referrents are instance members and the current + /// context is not an instance method. + IMA_Error_StaticContext, + + /// All possible referrents are instance members of an unrelated + /// class. + IMA_Error_Unrelated +}; + +/// The given lookup names class member(s) and is not being used for +/// an address-of-member expression. Classify the type of access +/// according to whether it's possible that this reference names an +/// instance member. This is best-effort; it is okay to +/// conservatively answer "yes", in which case some errors will simply +/// not be caught until template-instantiation. +static IMAKind ClassifyImplicitMemberAccess(Sema &SemaRef, + const LookupResult &R) { + assert(!R.empty() && (*R.begin())->isCXXClassMember()); + + DeclContext *DC = SemaRef.getFunctionLevelDeclContext(); + bool isStaticContext = + (!isa<CXXMethodDecl>(DC) || + cast<CXXMethodDecl>(DC)->isStatic()); + + if (R.isUnresolvableResult()) + return isStaticContext ? IMA_Unresolved_StaticContext : IMA_Unresolved; + + // Collect all the declaring classes of instance members we find. + bool hasNonInstance = false; + bool hasField = false; + llvm::SmallPtrSet<CXXRecordDecl*, 4> Classes; + for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { + NamedDecl *D = *I; + + if (D->isCXXInstanceMember()) { + if (dyn_cast<FieldDecl>(D)) + hasField = true; + + CXXRecordDecl *R = cast<CXXRecordDecl>(D->getDeclContext()); + Classes.insert(R->getCanonicalDecl()); + } + else + hasNonInstance = true; + } + + // If we didn't find any instance members, it can't be an implicit + // member reference. + if (Classes.empty()) + return IMA_Static; + + // If the current context is not an instance method, it can't be + // an implicit member reference. + if (isStaticContext) { + if (hasNonInstance) + return IMA_Mixed_StaticContext; + + if (SemaRef.getLangOptions().CPlusPlus0x && hasField) { + // C++0x [expr.prim.general]p10: + // An id-expression that denotes a non-static data member or non-static + // member function of a class can only be used: + // (...) + // - if that id-expression denotes a non-static data member and it appears in an unevaluated operand. + const Sema::ExpressionEvaluationContextRecord& record = SemaRef.ExprEvalContexts.back(); + bool isUnevaluatedExpression = record.Context == Sema::Unevaluated; + if (isUnevaluatedExpression) + return IMA_Mixed_StaticContext; + } + + return IMA_Error_StaticContext; + } + + CXXRecordDecl * + contextClass = cast<CXXMethodDecl>(DC)->getParent()->getCanonicalDecl(); + + // [class.mfct.non-static]p3: + // ...is used in the body of a non-static member function of class X, + // if name lookup (3.4.1) resolves the name in the id-expression to a + // non-static non-type member of some class C [...] + // ...if C is not X or a base class of X, the class member access expression + // is ill-formed. + if (R.getNamingClass() && + contextClass != R.getNamingClass()->getCanonicalDecl() && + contextClass->isProvablyNotDerivedFrom(R.getNamingClass())) + return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); + + // If we can prove that the current context is unrelated to all the + // declaring classes, it can't be an implicit member reference (in + // which case it's an error if any of those members are selected). + if (IsProvablyNotDerivedFrom(SemaRef, contextClass, Classes)) + return (hasNonInstance ? IMA_Mixed_Unrelated : IMA_Error_Unrelated); + + return (hasNonInstance ? IMA_Mixed : IMA_Instance); +} + +/// Diagnose a reference to a field with no object available. +static void DiagnoseInstanceReference(Sema &SemaRef, + const CXXScopeSpec &SS, + NamedDecl *rep, + const DeclarationNameInfo &nameInfo) { + SourceLocation Loc = nameInfo.getLoc(); + SourceRange Range(Loc); + if (SS.isSet()) Range.setBegin(SS.getRange().getBegin()); + + if (isa<FieldDecl>(rep) || isa<IndirectFieldDecl>(rep)) { + if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(SemaRef.CurContext)) { + if (MD->isStatic()) { + // "invalid use of member 'x' in static member function" + SemaRef.Diag(Loc, diag::err_invalid_member_use_in_static_method) + << Range << nameInfo.getName(); + return; + } + } + + SemaRef.Diag(Loc, diag::err_invalid_non_static_member_use) + << nameInfo.getName() << Range; + return; + } + + SemaRef.Diag(Loc, diag::err_member_call_without_object) << Range; +} + +/// Diagnose an empty lookup. +/// +/// \return false if new lookup candidates were found +bool Sema::DiagnoseEmptyLookup(Scope *S, CXXScopeSpec &SS, LookupResult &R, + CorrectTypoContext CTC) { + DeclarationName Name = R.getLookupName(); + + unsigned diagnostic = diag::err_undeclared_var_use; + unsigned diagnostic_suggest = diag::err_undeclared_var_use_suggest; + if (Name.getNameKind() == DeclarationName::CXXOperatorName || + Name.getNameKind() == DeclarationName::CXXLiteralOperatorName || + Name.getNameKind() == DeclarationName::CXXConversionFunctionName) { + diagnostic = diag::err_undeclared_use; + diagnostic_suggest = diag::err_undeclared_use_suggest; + } + + // If the original lookup was an unqualified lookup, fake an + // unqualified lookup. This is useful when (for example) the + // original lookup would not have found something because it was a + // dependent name. + for (DeclContext *DC = SS.isEmpty() ? CurContext : 0; + DC; DC = DC->getParent()) { + if (isa<CXXRecordDecl>(DC)) { + LookupQualifiedName(R, DC); + + if (!R.empty()) { + // Don't give errors about ambiguities in this lookup. + R.suppressDiagnostics(); + + CXXMethodDecl *CurMethod = dyn_cast<CXXMethodDecl>(CurContext); + bool isInstance = CurMethod && + CurMethod->isInstance() && + DC == CurMethod->getParent(); + + // Give a code modification hint to insert 'this->'. + // TODO: fixit for inserting 'Base<T>::' in the other cases. + // Actually quite difficult! + if (isInstance) { + UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>( + CallsUndergoingInstantiation.back()->getCallee()); + CXXMethodDecl *DepMethod = cast_or_null<CXXMethodDecl>( + CurMethod->getInstantiatedFromMemberFunction()); + if (DepMethod) { + Diag(R.getNameLoc(), diagnostic) << Name + << FixItHint::CreateInsertion(R.getNameLoc(), "this->"); + QualType DepThisType = DepMethod->getThisType(Context); + CXXThisExpr *DepThis = new (Context) CXXThisExpr( + R.getNameLoc(), DepThisType, false); + TemplateArgumentListInfo TList; + if (ULE->hasExplicitTemplateArgs()) + ULE->copyTemplateArgumentsInto(TList); + + CXXScopeSpec SS; + SS.Adopt(ULE->getQualifierLoc()); + CXXDependentScopeMemberExpr *DepExpr = + CXXDependentScopeMemberExpr::Create( + Context, DepThis, DepThisType, true, SourceLocation(), + SS.getWithLocInContext(Context), NULL, + R.getLookupNameInfo(), &TList); + CallsUndergoingInstantiation.back()->setCallee(DepExpr); + } else { + // FIXME: we should be able to handle this case too. It is correct + // to add this-> here. This is a workaround for PR7947. + Diag(R.getNameLoc(), diagnostic) << Name; + } + } else { + Diag(R.getNameLoc(), diagnostic) << Name; + } + + // Do we really want to note all of these? + for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) + Diag((*I)->getLocation(), diag::note_dependent_var_use); + + // Tell the callee to try to recover. + return false; + } + + R.clear(); + } + } + + // We didn't find anything, so try to correct for a typo. + DeclarationName Corrected; + if (S && (Corrected = CorrectTypo(R, S, &SS, 0, false, CTC))) { + if (!R.empty()) { + if (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin())) { + if (SS.isEmpty()) + Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName() + << FixItHint::CreateReplacement(R.getNameLoc(), + R.getLookupName().getAsString()); + else + Diag(R.getNameLoc(), diag::err_no_member_suggest) + << Name << computeDeclContext(SS, false) << R.getLookupName() + << SS.getRange() + << FixItHint::CreateReplacement(R.getNameLoc(), + R.getLookupName().getAsString()); + if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) + Diag(ND->getLocation(), diag::note_previous_decl) + << ND->getDeclName(); + + // Tell the callee to try to recover. + return false; + } + + if (isa<TypeDecl>(*R.begin()) || isa<ObjCInterfaceDecl>(*R.begin())) { + // FIXME: If we ended up with a typo for a type name or + // Objective-C class name, we're in trouble because the parser + // is in the wrong place to recover. Suggest the typo + // correction, but don't make it a fix-it since we're not going + // to recover well anyway. + if (SS.isEmpty()) + Diag(R.getNameLoc(), diagnostic_suggest) << Name << R.getLookupName(); + else + Diag(R.getNameLoc(), diag::err_no_member_suggest) + << Name << computeDeclContext(SS, false) << R.getLookupName() + << SS.getRange(); + + // Don't try to recover; it won't work. + return true; + } + } else { + // FIXME: We found a keyword. Suggest it, but don't provide a fix-it + // because we aren't able to recover. + if (SS.isEmpty()) + Diag(R.getNameLoc(), diagnostic_suggest) << Name << Corrected; + else + Diag(R.getNameLoc(), diag::err_no_member_suggest) + << Name << computeDeclContext(SS, false) << Corrected + << SS.getRange(); + return true; + } + R.clear(); + } + + // Emit a special diagnostic for failed member lookups. + // FIXME: computing the declaration context might fail here (?) + if (!SS.isEmpty()) { + Diag(R.getNameLoc(), diag::err_no_member) + << Name << computeDeclContext(SS, false) + << SS.getRange(); + return true; + } + + // Give up, we can't recover. + Diag(R.getNameLoc(), diagnostic) << Name; + return true; +} + +ObjCPropertyDecl *Sema::canSynthesizeProvisionalIvar(IdentifierInfo *II) { + ObjCMethodDecl *CurMeth = getCurMethodDecl(); + ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); + if (!IDecl) + return 0; + ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); + if (!ClassImpDecl) + return 0; + ObjCPropertyDecl *property = LookupPropertyDecl(IDecl, II); + if (!property) + return 0; + if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) + if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic || + PIDecl->getPropertyIvarDecl()) + return 0; + return property; +} + +bool Sema::canSynthesizeProvisionalIvar(ObjCPropertyDecl *Property) { + ObjCMethodDecl *CurMeth = getCurMethodDecl(); + ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); + if (!IDecl) + return false; + ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); + if (!ClassImpDecl) + return false; + if (ObjCPropertyImplDecl *PIDecl + = ClassImpDecl->FindPropertyImplDecl(Property->getIdentifier())) + if (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic || + PIDecl->getPropertyIvarDecl()) + return false; + + return true; +} + +ObjCIvarDecl *Sema::SynthesizeProvisionalIvar(LookupResult &Lookup, + IdentifierInfo *II, + SourceLocation NameLoc) { + ObjCMethodDecl *CurMeth = getCurMethodDecl(); + bool LookForIvars; + if (Lookup.empty()) + LookForIvars = true; + else if (CurMeth->isClassMethod()) + LookForIvars = false; + else + LookForIvars = (Lookup.isSingleResult() && + Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod() && + (Lookup.getAsSingle<VarDecl>() != 0)); + if (!LookForIvars) + return 0; + + ObjCInterfaceDecl *IDecl = CurMeth->getClassInterface(); + if (!IDecl) + return 0; + ObjCImplementationDecl *ClassImpDecl = IDecl->getImplementation(); + if (!ClassImpDecl) + return 0; + bool DynamicImplSeen = false; + ObjCPropertyDecl *property = LookupPropertyDecl(IDecl, II); + if (!property) + return 0; + if (ObjCPropertyImplDecl *PIDecl = ClassImpDecl->FindPropertyImplDecl(II)) { + DynamicImplSeen = + (PIDecl->getPropertyImplementation() == ObjCPropertyImplDecl::Dynamic); + // property implementation has a designated ivar. No need to assume a new + // one. + if (!DynamicImplSeen && PIDecl->getPropertyIvarDecl()) + return 0; + } + if (!DynamicImplSeen) { + QualType PropType = Context.getCanonicalType(property->getType()); + ObjCIvarDecl *Ivar = ObjCIvarDecl::Create(Context, ClassImpDecl, + NameLoc, NameLoc, + II, PropType, /*Dinfo=*/0, + ObjCIvarDecl::Private, + (Expr *)0, true); + ClassImpDecl->addDecl(Ivar); + IDecl->makeDeclVisibleInContext(Ivar, false); + property->setPropertyIvarDecl(Ivar); + return Ivar; + } + return 0; +} + +ExprResult Sema::ActOnIdExpression(Scope *S, + CXXScopeSpec &SS, + UnqualifiedId &Id, + bool HasTrailingLParen, + bool isAddressOfOperand) { + assert(!(isAddressOfOperand && HasTrailingLParen) && + "cannot be direct & operand and have a trailing lparen"); + + if (SS.isInvalid()) + return ExprError(); + + TemplateArgumentListInfo TemplateArgsBuffer; + + // Decompose the UnqualifiedId into the following data. + DeclarationNameInfo NameInfo; + const TemplateArgumentListInfo *TemplateArgs; + DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, NameInfo, TemplateArgs); + + DeclarationName Name = NameInfo.getName(); + IdentifierInfo *II = Name.getAsIdentifierInfo(); + SourceLocation NameLoc = NameInfo.getLoc(); + + // C++ [temp.dep.expr]p3: + // An id-expression is type-dependent if it contains: + // -- an identifier that was declared with a dependent type, + // (note: handled after lookup) + // -- a template-id that is dependent, + // (note: handled in BuildTemplateIdExpr) + // -- a conversion-function-id that specifies a dependent type, + // -- a nested-name-specifier that contains a class-name that + // names a dependent type. + // Determine whether this is a member of an unknown specialization; + // we need to handle these differently. + bool DependentID = false; + if (Name.getNameKind() == DeclarationName::CXXConversionFunctionName && + Name.getCXXNameType()->isDependentType()) { + DependentID = true; + } else if (SS.isSet()) { + if (DeclContext *DC = computeDeclContext(SS, false)) { + if (RequireCompleteDeclContext(SS, DC)) + return ExprError(); + } else { + DependentID = true; + } + } + + if (DependentID) + return ActOnDependentIdExpression(SS, NameInfo, isAddressOfOperand, + TemplateArgs); + + bool IvarLookupFollowUp = false; + // Perform the required lookup. + LookupResult R(*this, NameInfo, LookupOrdinaryName); + if (TemplateArgs) { + // Lookup the template name again to correctly establish the context in + // which it was found. This is really unfortunate as we already did the + // lookup to determine that it was a template name in the first place. If + // this becomes a performance hit, we can work harder to preserve those + // results until we get here but it's likely not worth it. + bool MemberOfUnknownSpecialization; + LookupTemplateName(R, S, SS, QualType(), /*EnteringContext=*/false, + MemberOfUnknownSpecialization); + + if (MemberOfUnknownSpecialization || + (R.getResultKind() == LookupResult::NotFoundInCurrentInstantiation)) + return ActOnDependentIdExpression(SS, NameInfo, isAddressOfOperand, + TemplateArgs); + } else { + IvarLookupFollowUp = (!SS.isSet() && II && getCurMethodDecl()); + LookupParsedName(R, S, &SS, !IvarLookupFollowUp); + + // If the result might be in a dependent base class, this is a dependent + // id-expression. + if (R.getResultKind() == LookupResult::NotFoundInCurrentInstantiation) + return ActOnDependentIdExpression(SS, NameInfo, isAddressOfOperand, + TemplateArgs); + + // If this reference is in an Objective-C method, then we need to do + // some special Objective-C lookup, too. + if (IvarLookupFollowUp) { + ExprResult E(LookupInObjCMethod(R, S, II, true)); + if (E.isInvalid()) + return ExprError(); + + if (Expr *Ex = E.takeAs<Expr>()) + return Owned(Ex); + + // Synthesize ivars lazily. + if (getLangOptions().ObjCDefaultSynthProperties && + getLangOptions().ObjCNonFragileABI2) { + if (SynthesizeProvisionalIvar(R, II, NameLoc)) { + if (const ObjCPropertyDecl *Property = + canSynthesizeProvisionalIvar(II)) { + Diag(NameLoc, diag::warn_synthesized_ivar_access) << II; + Diag(Property->getLocation(), diag::note_property_declare); + } + return ActOnIdExpression(S, SS, Id, HasTrailingLParen, + isAddressOfOperand); + } + } + // for further use, this must be set to false if in class method. + IvarLookupFollowUp = getCurMethodDecl()->isInstanceMethod(); + } + } + + if (R.isAmbiguous()) + return ExprError(); + + // Determine whether this name might be a candidate for + // argument-dependent lookup. + bool ADL = UseArgumentDependentLookup(SS, R, HasTrailingLParen); + + if (R.empty() && !ADL) { + // Otherwise, this could be an implicitly declared function reference (legal + // in C90, extension in C99, forbidden in C++). + if (HasTrailingLParen && II && !getLangOptions().CPlusPlus) { + NamedDecl *D = ImplicitlyDefineFunction(NameLoc, *II, S); + if (D) R.addDecl(D); + } + + // If this name wasn't predeclared and if this is not a function + // call, diagnose the problem. + if (R.empty()) { + if (DiagnoseEmptyLookup(S, SS, R, CTC_Unknown)) + return ExprError(); + + assert(!R.empty() && + "DiagnoseEmptyLookup returned false but added no results"); + + // If we found an Objective-C instance variable, let + // LookupInObjCMethod build the appropriate expression to + // reference the ivar. + if (ObjCIvarDecl *Ivar = R.getAsSingle<ObjCIvarDecl>()) { + R.clear(); + ExprResult E(LookupInObjCMethod(R, S, Ivar->getIdentifier())); + assert(E.isInvalid() || E.get()); + return move(E); + } + } + } + + // This is guaranteed from this point on. + assert(!R.empty() || ADL); + + // Check whether this might be a C++ implicit instance member access. + // C++ [class.mfct.non-static]p3: + // When an id-expression that is not part of a class member access + // syntax and not used to form a pointer to member is used in the + // body of a non-static member function of class X, if name lookup + // resolves the name in the id-expression to a non-static non-type + // member of some class C, the id-expression is transformed into a + // class member access expression using (*this) as the + // postfix-expression to the left of the . operator. + // + // But we don't actually need to do this for '&' operands if R + // resolved to a function or overloaded function set, because the + // expression is ill-formed if it actually works out to be a + // non-static member function: + // + // C++ [expr.ref]p4: + // Otherwise, if E1.E2 refers to a non-static member function. . . + // [t]he expression can be used only as the left-hand operand of a + // member function call. + // + // There are other safeguards against such uses, but it's important + // to get this right here so that we don't end up making a + // spuriously dependent expression if we're inside a dependent + // instance method. + if (!R.empty() && (*R.begin())->isCXXClassMember()) { + bool MightBeImplicitMember; + if (!isAddressOfOperand) + MightBeImplicitMember = true; + else if (!SS.isEmpty()) + MightBeImplicitMember = false; + else if (R.isOverloadedResult()) + MightBeImplicitMember = false; + else if (R.isUnresolvableResult()) + MightBeImplicitMember = true; + else + MightBeImplicitMember = isa<FieldDecl>(R.getFoundDecl()) || + isa<IndirectFieldDecl>(R.getFoundDecl()); + + if (MightBeImplicitMember) + return BuildPossibleImplicitMemberExpr(SS, R, TemplateArgs); + } + + if (TemplateArgs) + return BuildTemplateIdExpr(SS, R, ADL, *TemplateArgs); + + return BuildDeclarationNameExpr(SS, R, ADL); +} + +/// Builds an expression which might be an implicit member expression. +ExprResult +Sema::BuildPossibleImplicitMemberExpr(const CXXScopeSpec &SS, + LookupResult &R, + const TemplateArgumentListInfo *TemplateArgs) { + switch (ClassifyImplicitMemberAccess(*this, R)) { + case IMA_Instance: + return BuildImplicitMemberExpr(SS, R, TemplateArgs, true); + + case IMA_Mixed: + case IMA_Mixed_Unrelated: + case IMA_Unresolved: + return BuildImplicitMemberExpr(SS, R, TemplateArgs, false); + + case IMA_Static: + case IMA_Mixed_StaticContext: + case IMA_Unresolved_StaticContext: + if (TemplateArgs) + return BuildTemplateIdExpr(SS, R, false, *TemplateArgs); + return BuildDeclarationNameExpr(SS, R, false); + + case IMA_Error_StaticContext: + case IMA_Error_Unrelated: + DiagnoseInstanceReference(*this, SS, R.getRepresentativeDecl(), + R.getLookupNameInfo()); + return ExprError(); + } + + llvm_unreachable("unexpected instance member access kind"); + return ExprError(); +} + +/// BuildQualifiedDeclarationNameExpr - Build a C++ qualified +/// declaration name, generally during template instantiation. +/// There's a large number of things which don't need to be done along +/// this path. +ExprResult +Sema::BuildQualifiedDeclarationNameExpr(CXXScopeSpec &SS, + const DeclarationNameInfo &NameInfo) { + DeclContext *DC; + if (!(DC = computeDeclContext(SS, false)) || DC->isDependentContext()) + return BuildDependentDeclRefExpr(SS, NameInfo, 0); + + if (RequireCompleteDeclContext(SS, DC)) + return ExprError(); + + LookupResult R(*this, NameInfo, LookupOrdinaryName); + LookupQualifiedName(R, DC); + + if (R.isAmbiguous()) + return ExprError(); + + if (R.empty()) { + Diag(NameInfo.getLoc(), diag::err_no_member) + << NameInfo.getName() << DC << SS.getRange(); + return ExprError(); + } + + return BuildDeclarationNameExpr(SS, R, /*ADL*/ false); +} + +/// LookupInObjCMethod - The parser has read a name in, and Sema has +/// detected that we're currently inside an ObjC method. Perform some +/// additional lookup. +/// +/// Ideally, most of this would be done by lookup, but there's +/// actually quite a lot of extra work involved. +/// +/// Returns a null sentinel to indicate trivial success. +ExprResult +Sema::LookupInObjCMethod(LookupResult &Lookup, Scope *S, + IdentifierInfo *II, bool AllowBuiltinCreation) { + SourceLocation Loc = Lookup.getNameLoc(); + ObjCMethodDecl *CurMethod = getCurMethodDecl(); + + // There are two cases to handle here. 1) scoped lookup could have failed, + // in which case we should look for an ivar. 2) scoped lookup could have + // found a decl, but that decl is outside the current instance method (i.e. + // a global variable). In these two cases, we do a lookup for an ivar with + // this name, if the lookup sucedes, we replace it our current decl. + + // If we're in a class method, we don't normally want to look for + // ivars. But if we don't find anything else, and there's an + // ivar, that's an error. + bool IsClassMethod = CurMethod->isClassMethod(); + + bool LookForIvars; + if (Lookup.empty()) + LookForIvars = true; + else if (IsClassMethod) + LookForIvars = false; + else + LookForIvars = (Lookup.isSingleResult() && + Lookup.getFoundDecl()->isDefinedOutsideFunctionOrMethod()); + ObjCInterfaceDecl *IFace = 0; + if (LookForIvars) { + IFace = CurMethod->getClassInterface(); + ObjCInterfaceDecl *ClassDeclared; + if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { + // Diagnose using an ivar in a class method. + if (IsClassMethod) + return ExprError(Diag(Loc, diag::error_ivar_use_in_class_method) + << IV->getDeclName()); + + // If we're referencing an invalid decl, just return this as a silent + // error node. The error diagnostic was already emitted on the decl. + if (IV->isInvalidDecl()) + return ExprError(); + + // Check if referencing a field with __attribute__((deprecated)). + if (DiagnoseUseOfDecl(IV, Loc)) + return ExprError(); + + // Diagnose the use of an ivar outside of the declaring class. + if (IV->getAccessControl() == ObjCIvarDecl::Private && + ClassDeclared != IFace) + Diag(Loc, diag::error_private_ivar_access) << IV->getDeclName(); + + // FIXME: This should use a new expr for a direct reference, don't + // turn this into Self->ivar, just return a BareIVarExpr or something. + IdentifierInfo &II = Context.Idents.get("self"); + UnqualifiedId SelfName; + SelfName.setIdentifier(&II, SourceLocation()); + CXXScopeSpec SelfScopeSpec; + ExprResult SelfExpr = ActOnIdExpression(S, SelfScopeSpec, + SelfName, false, false); + if (SelfExpr.isInvalid()) + return ExprError(); + + SelfExpr = DefaultLvalueConversion(SelfExpr.take()); + if (SelfExpr.isInvalid()) + return ExprError(); + + MarkDeclarationReferenced(Loc, IV); + Expr *base = SelfExpr.take(); + base = base->IgnoreParenImpCasts(); + if (const DeclRefExpr *DE = dyn_cast<DeclRefExpr>(base)) { + const NamedDecl *ND = DE->getDecl(); + if (!isa<ImplicitParamDecl>(ND)) { + // relax the rule such that it is allowed to have a shadow 'self' + // where stand-alone ivar can be found in this 'self' object. + // This is to match gcc's behavior. + ObjCInterfaceDecl *selfIFace = 0; + if (const ObjCObjectPointerType *OPT = + base->getType()->getAsObjCInterfacePointerType()) + selfIFace = OPT->getInterfaceDecl(); + if (!selfIFace || + !selfIFace->lookupInstanceVariable(IV->getIdentifier())) { + Diag(Loc, diag::error_implicit_ivar_access) + << IV->getDeclName(); + Diag(ND->getLocation(), diag::note_declared_at); + return ExprError(); + } + } + } + return Owned(new (Context) + ObjCIvarRefExpr(IV, IV->getType(), Loc, + SelfExpr.take(), true, true)); + } + } else if (CurMethod->isInstanceMethod()) { + // We should warn if a local variable hides an ivar. + ObjCInterfaceDecl *IFace = CurMethod->getClassInterface(); + ObjCInterfaceDecl *ClassDeclared; + if (ObjCIvarDecl *IV = IFace->lookupInstanceVariable(II, ClassDeclared)) { + if (IV->getAccessControl() != ObjCIvarDecl::Private || + IFace == ClassDeclared) + Diag(Loc, diag::warn_ivar_use_hidden) << IV->getDeclName(); + } + } + + if (Lookup.empty() && II && AllowBuiltinCreation) { + // FIXME. Consolidate this with similar code in LookupName. + if (unsigned BuiltinID = II->getBuiltinID()) { + if (!(getLangOptions().CPlusPlus && + Context.BuiltinInfo.isPredefinedLibFunction(BuiltinID))) { + NamedDecl *D = LazilyCreateBuiltin((IdentifierInfo *)II, BuiltinID, + S, Lookup.isForRedeclaration(), + Lookup.getNameLoc()); + if (D) Lookup.addDecl(D); + } + } + } + // Sentinel value saying that we didn't do anything special. + return Owned((Expr*) 0); +} + +/// \brief Cast a base object to a member's actual type. +/// +/// Logically this happens in three phases: +/// +/// * First we cast from the base type to the naming class. +/// The naming class is the class into which we were looking +/// when we found the member; it's the qualifier type if a +/// qualifier was provided, and otherwise it's the base type. +/// +/// * Next we cast from the naming class to the declaring class. +/// If the member we found was brought into a class's scope by +/// a using declaration, this is that class; otherwise it's +/// the class declaring the member. +/// +/// * Finally we cast from the declaring class to the "true" +/// declaring class of the member. This conversion does not +/// obey access control. +ExprResult +Sema::PerformObjectMemberConversion(Expr *From, + NestedNameSpecifier *Qualifier, + NamedDecl *FoundDecl, + NamedDecl *Member) { + CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Member->getDeclContext()); + if (!RD) + return Owned(From); + + QualType DestRecordType; + QualType DestType; + QualType FromRecordType; + QualType FromType = From->getType(); + bool PointerConversions = false; + if (isa<FieldDecl>(Member)) { + DestRecordType = Context.getCanonicalType(Context.getTypeDeclType(RD)); + + if (FromType->getAs<PointerType>()) { + DestType = Context.getPointerType(DestRecordType); + FromRecordType = FromType->getPointeeType(); + PointerConversions = true; + } else { + DestType = DestRecordType; + FromRecordType = FromType; + } + } else if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Member)) { + if (Method->isStatic()) + return Owned(From); + + DestType = Method->getThisType(Context); + DestRecordType = DestType->getPointeeType(); + + if (FromType->getAs<PointerType>()) { + FromRecordType = FromType->getPointeeType(); + PointerConversions = true; + } else { + FromRecordType = FromType; + DestType = DestRecordType; + } + } else { + // No conversion necessary. + return Owned(From); + } + + if (DestType->isDependentType() || FromType->isDependentType()) + return Owned(From); + + // If the unqualified types are the same, no conversion is necessary. + if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) + return Owned(From); + + SourceRange FromRange = From->getSourceRange(); + SourceLocation FromLoc = FromRange.getBegin(); + + ExprValueKind VK = CastCategory(From); + + // C++ [class.member.lookup]p8: + // [...] Ambiguities can often be resolved by qualifying a name with its + // class name. + // + // If the member was a qualified name and the qualified referred to a + // specific base subobject type, we'll cast to that intermediate type + // first and then to the object in which the member is declared. That allows + // one to resolve ambiguities in, e.g., a diamond-shaped hierarchy such as: + // + // class Base { public: int x; }; + // class Derived1 : public Base { }; + // class Derived2 : public Base { }; + // class VeryDerived : public Derived1, public Derived2 { void f(); }; + // + // void VeryDerived::f() { + // x = 17; // error: ambiguous base subobjects + // Derived1::x = 17; // okay, pick the Base subobject of Derived1 + // } + if (Qualifier) { + QualType QType = QualType(Qualifier->getAsType(), 0); + assert(!QType.isNull() && "lookup done with dependent qualifier?"); + assert(QType->isRecordType() && "lookup done with non-record type"); + + QualType QRecordType = QualType(QType->getAs<RecordType>(), 0); + + // In C++98, the qualifier type doesn't actually have to be a base + // type of the object type, in which case we just ignore it. + // Otherwise build the appropriate casts. + if (IsDerivedFrom(FromRecordType, QRecordType)) { + CXXCastPath BasePath; + if (CheckDerivedToBaseConversion(FromRecordType, QRecordType, + FromLoc, FromRange, &BasePath)) + return ExprError(); + + if (PointerConversions) + QType = Context.getPointerType(QType); + From = ImpCastExprToType(From, QType, CK_UncheckedDerivedToBase, + VK, &BasePath).take(); + + FromType = QType; + FromRecordType = QRecordType; + + // If the qualifier type was the same as the destination type, + // we're done. + if (Context.hasSameUnqualifiedType(FromRecordType, DestRecordType)) + return Owned(From); + } + } + + bool IgnoreAccess = false; + + // If we actually found the member through a using declaration, cast + // down to the using declaration's type. + // + // Pointer equality is fine here because only one declaration of a + // class ever has member declarations. + if (FoundDecl->getDeclContext() != Member->getDeclContext()) { + assert(isa<UsingShadowDecl>(FoundDecl)); + QualType URecordType = Context.getTypeDeclType( + cast<CXXRecordDecl>(FoundDecl->getDeclContext())); + + // We only need to do this if the naming-class to declaring-class + // conversion is non-trivial. + if (!Context.hasSameUnqualifiedType(FromRecordType, URecordType)) { + assert(IsDerivedFrom(FromRecordType, URecordType)); + CXXCastPath BasePath; + if (CheckDerivedToBaseConversion(FromRecordType, URecordType, + FromLoc, FromRange, &BasePath)) + return ExprError(); + + QualType UType = URecordType; + if (PointerConversions) + UType = Context.getPointerType(UType); + From = ImpCastExprToType(From, UType, CK_UncheckedDerivedToBase, + VK, &BasePath).take(); + FromType = UType; + FromRecordType = URecordType; + } + + // We don't do access control for the conversion from the + // declaring class to the true declaring class. + IgnoreAccess = true; + } + + CXXCastPath BasePath; + if (CheckDerivedToBaseConversion(FromRecordType, DestRecordType, + FromLoc, FromRange, &BasePath, + IgnoreAccess)) + return ExprError(); + + return ImpCastExprToType(From, DestType, CK_UncheckedDerivedToBase, + VK, &BasePath); +} + +/// \brief Build a MemberExpr AST node. +static MemberExpr *BuildMemberExpr(ASTContext &C, Expr *Base, bool isArrow, + const CXXScopeSpec &SS, ValueDecl *Member, + DeclAccessPair FoundDecl, + const DeclarationNameInfo &MemberNameInfo, + QualType Ty, + ExprValueKind VK, ExprObjectKind OK, + const TemplateArgumentListInfo *TemplateArgs = 0) { + return MemberExpr::Create(C, Base, isArrow, SS.getWithLocInContext(C), + Member, FoundDecl, MemberNameInfo, + TemplateArgs, Ty, VK, OK); +} + +static ExprResult +BuildFieldReferenceExpr(Sema &S, Expr *BaseExpr, bool IsArrow, + const CXXScopeSpec &SS, FieldDecl *Field, + DeclAccessPair FoundDecl, + const DeclarationNameInfo &MemberNameInfo) { + // x.a is an l-value if 'a' has a reference type. Otherwise: + // x.a is an l-value/x-value/pr-value if the base is (and note + // that *x is always an l-value), except that if the base isn't + // an ordinary object then we must have an rvalue. + ExprValueKind VK = VK_LValue; + ExprObjectKind OK = OK_Ordinary; + if (!IsArrow) { + if (BaseExpr->getObjectKind() == OK_Ordinary) + VK = BaseExpr->getValueKind(); + else + VK = VK_RValue; + } + if (VK != VK_RValue && Field->isBitField()) + OK = OK_BitField; + + // Figure out the type of the member; see C99 6.5.2.3p3, C++ [expr.ref] + QualType MemberType = Field->getType(); + if (const ReferenceType *Ref = MemberType->getAs<ReferenceType>()) { + MemberType = Ref->getPointeeType(); + VK = VK_LValue; + } else { + QualType BaseType = BaseExpr->getType(); + if (IsArrow) BaseType = BaseType->getAs<PointerType>()->getPointeeType(); + + Qualifiers BaseQuals = BaseType.getQualifiers(); + + // GC attributes are never picked up by members. + BaseQuals.removeObjCGCAttr(); + + // CVR attributes from the base are picked up by members, + // except that 'mutable' members don't pick up 'const'. + if (Field->isMutable()) BaseQuals.removeConst(); + + Qualifiers MemberQuals + = S.Context.getCanonicalType(MemberType).getQualifiers(); + + // TR 18037 does not allow fields to be declared with address spaces. + assert(!MemberQuals.hasAddressSpace()); + + Qualifiers Combined = BaseQuals + MemberQuals; + if (Combined != MemberQuals) + MemberType = S.Context.getQualifiedType(MemberType, Combined); + } + + S.MarkDeclarationReferenced(MemberNameInfo.getLoc(), Field); + ExprResult Base = + S.PerformObjectMemberConversion(BaseExpr, SS.getScopeRep(), + FoundDecl, Field); + if (Base.isInvalid()) + return ExprError(); + return S.Owned(BuildMemberExpr(S.Context, Base.take(), IsArrow, SS, + Field, FoundDecl, MemberNameInfo, + MemberType, VK, OK)); +} + +/// Builds an implicit member access expression. The current context +/// is known to be an instance method, and the given unqualified lookup +/// set is known to contain only instance members, at least one of which +/// is from an appropriate type. +ExprResult +Sema::BuildImplicitMemberExpr(const CXXScopeSpec &SS, + LookupResult &R, + const TemplateArgumentListInfo *TemplateArgs, + bool IsKnownInstance) { + assert(!R.empty() && !R.isAmbiguous()); + + SourceLocation loc = R.getNameLoc(); + + // We may have found a field within an anonymous union or struct + // (C++ [class.union]). + // FIXME: template-ids inside anonymous structs? + if (IndirectFieldDecl *FD = R.getAsSingle<IndirectFieldDecl>()) + return BuildAnonymousStructUnionMemberReference(SS, R.getNameLoc(), FD); + + // If this is known to be an instance access, go ahead and build an + // implicit 'this' expression now. + // 'this' expression now. + CXXMethodDecl *method = tryCaptureCXXThis(); + assert(method && "didn't correctly pre-flight capture of 'this'"); + + QualType thisType = method->getThisType(Context); + Expr *baseExpr = 0; // null signifies implicit access + if (IsKnownInstance) { + SourceLocation Loc = R.getNameLoc(); + if (SS.getRange().isValid()) + Loc = SS.getRange().getBegin(); + baseExpr = new (Context) CXXThisExpr(loc, thisType, /*isImplicit=*/true); + } + + return BuildMemberReferenceExpr(baseExpr, thisType, + /*OpLoc*/ SourceLocation(), + /*IsArrow*/ true, + SS, + /*FirstQualifierInScope*/ 0, + R, TemplateArgs); +} + +bool Sema::UseArgumentDependentLookup(const CXXScopeSpec &SS, + const LookupResult &R, + bool HasTrailingLParen) { + // Only when used directly as the postfix-expression of a call. + if (!HasTrailingLParen) + return false; + + // Never if a scope specifier was provided. + if (SS.isSet()) + return false; + + // Only in C++ or ObjC++. + if (!getLangOptions().CPlusPlus) + return false; + + // Turn off ADL when we find certain kinds of declarations during + // normal lookup: + for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { + NamedDecl *D = *I; + + // C++0x [basic.lookup.argdep]p3: + // -- a declaration of a class member + // Since using decls preserve this property, we check this on the + // original decl. + if (D->isCXXClassMember()) + return false; + + // C++0x [basic.lookup.argdep]p3: + // -- a block-scope function declaration that is not a + // using-declaration + // NOTE: we also trigger this for function templates (in fact, we + // don't check the decl type at all, since all other decl types + // turn off ADL anyway). + if (isa<UsingShadowDecl>(D)) + D = cast<UsingShadowDecl>(D)->getTargetDecl(); + else if (D->getDeclContext()->isFunctionOrMethod()) + return false; + + // C++0x [basic.lookup.argdep]p3: + // -- a declaration that is neither a function or a function + // template + // And also for builtin functions. + if (isa<FunctionDecl>(D)) { + FunctionDecl *FDecl = cast<FunctionDecl>(D); + + // But also builtin functions. + if (FDecl->getBuiltinID() && FDecl->isImplicit()) + return false; + } else if (!isa<FunctionTemplateDecl>(D)) + return false; + } + + return true; +} + + +/// Diagnoses obvious problems with the use of the given declaration +/// as an expression. This is only actually called for lookups that +/// were not overloaded, and it doesn't promise that the declaration +/// will in fact be used. +static bool CheckDeclInExpr(Sema &S, SourceLocation Loc, NamedDecl *D) { + if (isa<TypedefNameDecl>(D)) { + S.Diag(Loc, diag::err_unexpected_typedef) << D->getDeclName(); + return true; + } + + if (isa<ObjCInterfaceDecl>(D)) { + S.Diag(Loc, diag::err_unexpected_interface) << D->getDeclName(); + return true; + } + + if (isa<NamespaceDecl>(D)) { + S.Diag(Loc, diag::err_unexpected_namespace) << D->getDeclName(); + return true; + } + + return false; +} + +ExprResult +Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, + LookupResult &R, + bool NeedsADL) { + // If this is a single, fully-resolved result and we don't need ADL, + // just build an ordinary singleton decl ref. + if (!NeedsADL && R.isSingleResult() && !R.getAsSingle<FunctionTemplateDecl>()) + return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), + R.getFoundDecl()); + + // We only need to check the declaration if there's exactly one + // result, because in the overloaded case the results can only be + // functions and function templates. + if (R.isSingleResult() && + CheckDeclInExpr(*this, R.getNameLoc(), R.getFoundDecl())) + return ExprError(); + + // Otherwise, just build an unresolved lookup expression. Suppress + // any lookup-related diagnostics; we'll hash these out later, when + // we've picked a target. + R.suppressDiagnostics(); + + UnresolvedLookupExpr *ULE + = UnresolvedLookupExpr::Create(Context, R.getNamingClass(), + SS.getWithLocInContext(Context), + R.getLookupNameInfo(), + NeedsADL, R.isOverloadedResult(), + R.begin(), R.end()); + + return Owned(ULE); +} + +/// \brief Complete semantic analysis for a reference to the given declaration. +ExprResult +Sema::BuildDeclarationNameExpr(const CXXScopeSpec &SS, + const DeclarationNameInfo &NameInfo, + NamedDecl *D) { + assert(D && "Cannot refer to a NULL declaration"); + assert(!isa<FunctionTemplateDecl>(D) && + "Cannot refer unambiguously to a function template"); + + SourceLocation Loc = NameInfo.getLoc(); + if (CheckDeclInExpr(*this, Loc, D)) + return ExprError(); + + if (TemplateDecl *Template = dyn_cast<TemplateDecl>(D)) { + // Specifically diagnose references to class templates that are missing + // a template argument list. + Diag(Loc, diag::err_template_decl_ref) + << Template << SS.getRange(); + Diag(Template->getLocation(), diag::note_template_decl_here); + return ExprError(); + } + + // Make sure that we're referring to a value. + ValueDecl *VD = dyn_cast<ValueDecl>(D); + if (!VD) { + Diag(Loc, diag::err_ref_non_value) + << D << SS.getRange(); + Diag(D->getLocation(), diag::note_declared_at); + return ExprError(); + } + + // Check whether this declaration can be used. Note that we suppress + // this check when we're going to perform argument-dependent lookup + // on this function name, because this might not be the function + // that overload resolution actually selects. + if (DiagnoseUseOfDecl(VD, Loc)) + return ExprError(); + + // Only create DeclRefExpr's for valid Decl's. + if (VD->isInvalidDecl()) + return ExprError(); + + // Handle members of anonymous structs and unions. If we got here, + // and the reference is to a class member indirect field, then this + // must be the subject of a pointer-to-member expression. + if (IndirectFieldDecl *indirectField = dyn_cast<IndirectFieldDecl>(VD)) + if (!indirectField->isCXXClassMember()) + return BuildAnonymousStructUnionMemberReference(SS, NameInfo.getLoc(), + indirectField); + + // If the identifier reference is inside a block, and it refers to a value + // that is outside the block, create a BlockDeclRefExpr instead of a + // DeclRefExpr. This ensures the value is treated as a copy-in snapshot when + // the block is formed. + // + // We do not do this for things like enum constants, global variables, etc, + // as they do not get snapshotted. + // + switch (shouldCaptureValueReference(*this, NameInfo.getLoc(), VD)) { + case CR_Error: + return ExprError(); + + case CR_Capture: + assert(!SS.isSet() && "referenced local variable with scope specifier?"); + return BuildBlockDeclRefExpr(*this, VD, NameInfo, /*byref*/ false); + + case CR_CaptureByRef: + assert(!SS.isSet() && "referenced local variable with scope specifier?"); + return BuildBlockDeclRefExpr(*this, VD, NameInfo, /*byref*/ true); + + case CR_NoCapture: { + // If this reference is not in a block or if the referenced + // variable is within the block, create a normal DeclRefExpr. + + QualType type = VD->getType(); + ExprValueKind valueKind = VK_RValue; + + switch (D->getKind()) { + // Ignore all the non-ValueDecl kinds. +#define ABSTRACT_DECL(kind) +#define VALUE(type, base) +#define DECL(type, base) \ + case Decl::type: +#include "clang/AST/DeclNodes.inc" + llvm_unreachable("invalid value decl kind"); + return ExprError(); + + // These shouldn't make it here. + case Decl::ObjCAtDefsField: + case Decl::ObjCIvar: + llvm_unreachable("forming non-member reference to ivar?"); + return ExprError(); + + // Enum constants are always r-values and never references. + // Unresolved using declarations are dependent. + case Decl::EnumConstant: + case Decl::UnresolvedUsingValue: + valueKind = VK_RValue; + break; + + // Fields and indirect fields that got here must be for + // pointer-to-member expressions; we just call them l-values for + // internal consistency, because this subexpression doesn't really + // exist in the high-level semantics. + case Decl::Field: + case Decl::IndirectField: + assert(getLangOptions().CPlusPlus && + "building reference to field in C?"); + + // These can't have reference type in well-formed programs, but + // for internal consistency we do this anyway. + type = type.getNonReferenceType(); + valueKind = VK_LValue; + break; + + // Non-type template parameters are either l-values or r-values + // depending on the type. + case Decl::NonTypeTemplateParm: { + if (const ReferenceType *reftype = type->getAs<ReferenceType>()) { + type = reftype->getPointeeType(); + valueKind = VK_LValue; // even if the parameter is an r-value reference + break; + } + + // For non-references, we need to strip qualifiers just in case + // the template parameter was declared as 'const int' or whatever. + valueKind = VK_RValue; + type = type.getUnqualifiedType(); + break; + } + + case Decl::Var: + // In C, "extern void blah;" is valid and is an r-value. + if (!getLangOptions().CPlusPlus && + !type.hasQualifiers() && + type->isVoidType()) { + valueKind = VK_RValue; + break; + } + // fallthrough + + case Decl::ImplicitParam: + case Decl::ParmVar: + // These are always l-values. + valueKind = VK_LValue; + type = type.getNonReferenceType(); + break; + + case Decl::Function: { + const FunctionType *fty = type->castAs<FunctionType>(); + + // If we're referring to a function with an __unknown_anytype + // result type, make the entire expression __unknown_anytype. + if (fty->getResultType() == Context.UnknownAnyTy) { + type = Context.UnknownAnyTy; + valueKind = VK_RValue; + break; + } + + // Functions are l-values in C++. + if (getLangOptions().CPlusPlus) { + valueKind = VK_LValue; + break; + } + + // C99 DR 316 says that, if a function type comes from a + // function definition (without a prototype), that type is only + // used for checking compatibility. Therefore, when referencing + // the function, we pretend that we don't have the full function + // type. + if (!cast<FunctionDecl>(VD)->hasPrototype() && + isa<FunctionProtoType>(fty)) + type = Context.getFunctionNoProtoType(fty->getResultType(), + fty->getExtInfo()); + + // Functions are r-values in C. + valueKind = VK_RValue; + break; + } + + case Decl::CXXMethod: + // If we're referring to a method with an __unknown_anytype + // result type, make the entire expression __unknown_anytype. + // This should only be possible with a type written directly. + if (const FunctionProtoType *proto = dyn_cast<FunctionProtoType>(VD->getType())) + if (proto->getResultType() == Context.UnknownAnyTy) { + type = Context.UnknownAnyTy; + valueKind = VK_RValue; + break; + } + + // C++ methods are l-values if static, r-values if non-static. + if (cast<CXXMethodDecl>(VD)->isStatic()) { + valueKind = VK_LValue; + break; + } + // fallthrough + + case Decl::CXXConversion: + case Decl::CXXDestructor: + case Decl::CXXConstructor: + valueKind = VK_RValue; + break; + } + + return BuildDeclRefExpr(VD, type, valueKind, NameInfo, &SS); + } + + } + + llvm_unreachable("unknown capture result"); + return ExprError(); +} + +ExprResult Sema::ActOnPredefinedExpr(SourceLocation Loc, tok::TokenKind Kind) { + PredefinedExpr::IdentType IT; + + switch (Kind) { + default: assert(0 && "Unknown simple primary expr!"); + case tok::kw___func__: IT = PredefinedExpr::Func; break; // [C99 6.4.2.2] + case tok::kw___FUNCTION__: IT = PredefinedExpr::Function; break; + case tok::kw___PRETTY_FUNCTION__: IT = PredefinedExpr::PrettyFunction; break; + } + + // Pre-defined identifiers are of type char[x], where x is the length of the + // string. + + Decl *currentDecl = getCurFunctionOrMethodDecl(); + if (!currentDecl && getCurBlock()) + currentDecl = getCurBlock()->TheDecl; + if (!currentDecl) { + Diag(Loc, diag::ext_predef_outside_function); + currentDecl = Context.getTranslationUnitDecl(); + } + + QualType ResTy; + if (cast<DeclContext>(currentDecl)->isDependentContext()) { + ResTy = Context.DependentTy; + } else { + unsigned Length = PredefinedExpr::ComputeName(IT, currentDecl).length(); + + llvm::APInt LengthI(32, Length + 1); + ResTy = Context.CharTy.withConst(); + ResTy = Context.getConstantArrayType(ResTy, LengthI, ArrayType::Normal, 0); + } + return Owned(new (Context) PredefinedExpr(Loc, ResTy, IT)); +} + +ExprResult Sema::ActOnCharacterConstant(const Token &Tok) { + llvm::SmallString<16> CharBuffer; + bool Invalid = false; + llvm::StringRef ThisTok = PP.getSpelling(Tok, CharBuffer, &Invalid); + if (Invalid) + return ExprError(); + + CharLiteralParser Literal(ThisTok.begin(), ThisTok.end(), Tok.getLocation(), + PP); + if (Literal.hadError()) + return ExprError(); + + QualType Ty; + if (!getLangOptions().CPlusPlus) + Ty = Context.IntTy; // 'x' and L'x' -> int in C. + else if (Literal.isWide()) + Ty = Context.WCharTy; // L'x' -> wchar_t in C++. + else if (Literal.isMultiChar()) + Ty = Context.IntTy; // 'wxyz' -> int in C++. + else + Ty = Context.CharTy; // 'x' -> char in C++ + + return Owned(new (Context) CharacterLiteral(Literal.getValue(), + Literal.isWide(), + Ty, Tok.getLocation())); +} + +ExprResult Sema::ActOnNumericConstant(const Token &Tok) { + // Fast path for a single digit (which is quite common). A single digit + // cannot have a trigraph, escaped newline, radix prefix, or type suffix. + if (Tok.getLength() == 1) { + const char Val = PP.getSpellingOfSingleCharacterNumericConstant(Tok); + unsigned IntSize = Context.Target.getIntWidth(); + return Owned(IntegerLiteral::Create(Context, llvm::APInt(IntSize, Val-'0'), + Context.IntTy, Tok.getLocation())); + } + + llvm::SmallString<512> IntegerBuffer; + // Add padding so that NumericLiteralParser can overread by one character. + IntegerBuffer.resize(Tok.getLength()+1); + const char *ThisTokBegin = &IntegerBuffer[0]; + + // Get the spelling of the token, which eliminates trigraphs, etc. + bool Invalid = false; + unsigned ActualLength = PP.getSpelling(Tok, ThisTokBegin, &Invalid); + if (Invalid) + return ExprError(); + + NumericLiteralParser Literal(ThisTokBegin, ThisTokBegin+ActualLength, + Tok.getLocation(), PP); + if (Literal.hadError) + return ExprError(); + + Expr *Res; + + if (Literal.isFloatingLiteral()) { + QualType Ty; + if (Literal.isFloat) + Ty = Context.FloatTy; + else if (!Literal.isLong) + Ty = Context.DoubleTy; + else + Ty = Context.LongDoubleTy; + + const llvm::fltSemantics &Format = Context.getFloatTypeSemantics(Ty); + + using llvm::APFloat; + APFloat Val(Format); + + APFloat::opStatus result = Literal.GetFloatValue(Val); + + // Overflow is always an error, but underflow is only an error if + // we underflowed to zero (APFloat reports denormals as underflow). + if ((result & APFloat::opOverflow) || + ((result & APFloat::opUnderflow) && Val.isZero())) { + unsigned diagnostic; + llvm::SmallString<20> buffer; + if (result & APFloat::opOverflow) { + diagnostic = diag::warn_float_overflow; + APFloat::getLargest(Format).toString(buffer); + } else { + diagnostic = diag::warn_float_underflow; + APFloat::getSmallest(Format).toString(buffer); + } + + Diag(Tok.getLocation(), diagnostic) + << Ty + << llvm::StringRef(buffer.data(), buffer.size()); + } + + bool isExact = (result == APFloat::opOK); + Res = FloatingLiteral::Create(Context, Val, isExact, Ty, Tok.getLocation()); + + if (Ty == Context.DoubleTy) { + if (getLangOptions().SinglePrecisionConstants) { + Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).take(); + } else if (getLangOptions().OpenCL && !getOpenCLOptions().cl_khr_fp64) { + Diag(Tok.getLocation(), diag::warn_double_const_requires_fp64); + Res = ImpCastExprToType(Res, Context.FloatTy, CK_FloatingCast).take(); + } + } + } else if (!Literal.isIntegerLiteral()) { + return ExprError(); + } else { + QualType Ty; + + // long long is a C99 feature. + if (!getLangOptions().C99 && !getLangOptions().CPlusPlus0x && + Literal.isLongLong) + Diag(Tok.getLocation(), diag::ext_longlong); + + // Get the value in the widest-possible width. + llvm::APInt ResultVal(Context.Target.getIntMaxTWidth(), 0); + + if (Literal.GetIntegerValue(ResultVal)) { + // If this value didn't fit into uintmax_t, warn and force to ull. + Diag(Tok.getLocation(), diag::warn_integer_too_large); + Ty = Context.UnsignedLongLongTy; + assert(Context.getTypeSize(Ty) == ResultVal.getBitWidth() && + "long long is not intmax_t?"); + } else { + // If this value fits into a ULL, try to figure out what else it fits into + // according to the rules of C99 6.4.4.1p5. + + // Octal, Hexadecimal, and integers with a U suffix are allowed to + // be an unsigned int. + bool AllowUnsigned = Literal.isUnsigned || Literal.getRadix() != 10; + + // Check from smallest to largest, picking the smallest type we can. + unsigned Width = 0; + if (!Literal.isLong && !Literal.isLongLong) { + // Are int/unsigned possibilities? + unsigned IntSize = Context.Target.getIntWidth(); + + // Does it fit in a unsigned int? + if (ResultVal.isIntN(IntSize)) { + // Does it fit in a signed int? + if (!Literal.isUnsigned && ResultVal[IntSize-1] == 0) + Ty = Context.IntTy; + else if (AllowUnsigned) + Ty = Context.UnsignedIntTy; + Width = IntSize; + } + } + + // Are long/unsigned long possibilities? + if (Ty.isNull() && !Literal.isLongLong) { + unsigned LongSize = Context.Target.getLongWidth(); + + // Does it fit in a unsigned long? + if (ResultVal.isIntN(LongSize)) { + // Does it fit in a signed long? + if (!Literal.isUnsigned && ResultVal[LongSize-1] == 0) + Ty = Context.LongTy; + else if (AllowUnsigned) + Ty = Context.UnsignedLongTy; + Width = LongSize; + } + } + + // Finally, check long long if needed. + if (Ty.isNull()) { + unsigned LongLongSize = Context.Target.getLongLongWidth(); + + // Does it fit in a unsigned long long? + if (ResultVal.isIntN(LongLongSize)) { + // Does it fit in a signed long long? + // To be compatible with MSVC, hex integer literals ending with the + // LL or i64 suffix are always signed in Microsoft mode. + if (!Literal.isUnsigned && (ResultVal[LongLongSize-1] == 0 || + (getLangOptions().Microsoft && Literal.isLongLong))) + Ty = Context.LongLongTy; + else if (AllowUnsigned) + Ty = Context.UnsignedLongLongTy; + Width = LongLongSize; + } + } + + // If we still couldn't decide a type, we probably have something that + // does not fit in a signed long long, but has no U suffix. + if (Ty.isNull()) { + Diag(Tok.getLocation(), diag::warn_integer_too_large_for_signed); + Ty = Context.UnsignedLongLongTy; + Width = Context.Target.getLongLongWidth(); + } + + if (ResultVal.getBitWidth() != Width) + ResultVal = ResultVal.trunc(Width); + } + Res = IntegerLiteral::Create(Context, ResultVal, Ty, Tok.getLocation()); + } + + // If this is an imaginary literal, create the ImaginaryLiteral wrapper. + if (Literal.isImaginary) + Res = new (Context) ImaginaryLiteral(Res, + Context.getComplexType(Res->getType())); + + return Owned(Res); +} + +ExprResult Sema::ActOnParenExpr(SourceLocation L, + SourceLocation R, Expr *E) { + assert((E != 0) && "ActOnParenExpr() missing expr"); + return Owned(new (Context) ParenExpr(L, R, E)); +} + +/// The UsualUnaryConversions() function is *not* called by this routine. +/// See C99 6.3.2.1p[2-4] for more details. +bool Sema::CheckUnaryExprOrTypeTraitOperand(QualType exprType, + SourceLocation OpLoc, + SourceRange ExprRange, + UnaryExprOrTypeTrait ExprKind) { + if (exprType->isDependentType()) + return false; + + // C++ [expr.sizeof]p2: "When applied to a reference or a reference type, + // the result is the size of the referenced type." + // C++ [expr.alignof]p3: "When alignof is applied to a reference type, the + // result shall be the alignment of the referenced type." + if (const ReferenceType *Ref = exprType->getAs<ReferenceType>()) + exprType = Ref->getPointeeType(); + + // [OpenCL 1.1 6.11.12] "The vec_step built-in function takes a built-in + // scalar or vector data type argument..." + // Every built-in scalar type (OpenCL 1.1 6.1.1) is either an arithmetic + // type (C99 6.2.5p18) or void. + if (ExprKind == UETT_VecStep) { + if (!(exprType->isArithmeticType() || exprType->isVoidType() || + exprType->isVectorType())) { + Diag(OpLoc, diag::err_vecstep_non_scalar_vector_type) + << exprType << ExprRange; + return true; + } + } + + // C99 6.5.3.4p1: + if (exprType->isFunctionType()) { + // alignof(function) is allowed as an extension. + if (ExprKind == UETT_SizeOf) + Diag(OpLoc, diag::ext_sizeof_function_type) + << ExprRange; + return false; + } + + // Allow sizeof(void)/alignof(void) as an extension. vec_step(void) is not + // an extension, as void is a built-in scalar type (OpenCL 1.1 6.1.1). + if (exprType->isVoidType()) { + if (ExprKind != UETT_VecStep) + Diag(OpLoc, diag::ext_sizeof_void_type) + << ExprKind << ExprRange; + return false; + } + + if (RequireCompleteType(OpLoc, exprType, + PDiag(diag::err_sizeof_alignof_incomplete_type) + << ExprKind << ExprRange)) + return true; + + // Reject sizeof(interface) and sizeof(interface<proto>) in 64-bit mode. + if (LangOpts.ObjCNonFragileABI && exprType->isObjCObjectType()) { + Diag(OpLoc, diag::err_sizeof_nonfragile_interface) + << exprType << (ExprKind == UETT_SizeOf) + << ExprRange; + return true; + } + + return false; +} + +static bool CheckAlignOfExpr(Sema &S, Expr *E, SourceLocation OpLoc, + SourceRange ExprRange) { + E = E->IgnoreParens(); + + // alignof decl is always ok. + if (isa<DeclRefExpr>(E)) + return false; + + // Cannot know anything else if the expression is dependent. + if (E->isTypeDependent()) + return false; + + if (E->getBitField()) { + S. Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 1 << ExprRange; + return true; + } + + // Alignment of a field access is always okay, so long as it isn't a + // bit-field. + if (MemberExpr *ME = dyn_cast<MemberExpr>(E)) + if (isa<FieldDecl>(ME->getMemberDecl())) + return false; + + return S.CheckUnaryExprOrTypeTraitOperand(E->getType(), OpLoc, ExprRange, + UETT_AlignOf); +} + +bool Sema::CheckVecStepExpr(Expr *E, SourceLocation OpLoc, + SourceRange ExprRange) { + E = E->IgnoreParens(); + + // Cannot know anything else if the expression is dependent. + if (E->isTypeDependent()) + return false; + + return CheckUnaryExprOrTypeTraitOperand(E->getType(), OpLoc, ExprRange, + UETT_VecStep); +} + +/// \brief Build a sizeof or alignof expression given a type operand. +ExprResult +Sema::CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo, + SourceLocation OpLoc, + UnaryExprOrTypeTrait ExprKind, + SourceRange R) { + if (!TInfo) + return ExprError(); + + QualType T = TInfo->getType(); + + if (!T->isDependentType() && + CheckUnaryExprOrTypeTraitOperand(T, OpLoc, R, ExprKind)) + return ExprError(); + + // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. + return Owned(new (Context) UnaryExprOrTypeTraitExpr(ExprKind, TInfo, + Context.getSizeType(), + OpLoc, R.getEnd())); +} + +/// \brief Build a sizeof or alignof expression given an expression +/// operand. +ExprResult +Sema::CreateUnaryExprOrTypeTraitExpr(Expr *E, SourceLocation OpLoc, + UnaryExprOrTypeTrait ExprKind, + SourceRange R) { + // Verify that the operand is valid. + bool isInvalid = false; + if (E->isTypeDependent()) { + // Delay type-checking for type-dependent expressions. + } else if (ExprKind == UETT_AlignOf) { + isInvalid = CheckAlignOfExpr(*this, E, OpLoc, R); + } else if (ExprKind == UETT_VecStep) { + isInvalid = CheckVecStepExpr(E, OpLoc, R); + } else if (E->getBitField()) { // C99 6.5.3.4p1. + Diag(OpLoc, diag::err_sizeof_alignof_bitfield) << 0; + isInvalid = true; + } else if (E->getType()->isPlaceholderType()) { + ExprResult PE = CheckPlaceholderExpr(E); + if (PE.isInvalid()) return ExprError(); + return CreateUnaryExprOrTypeTraitExpr(PE.take(), OpLoc, ExprKind, R); + } else { + isInvalid = CheckUnaryExprOrTypeTraitOperand(E->getType(), OpLoc, R, + UETT_SizeOf); + } + + if (isInvalid) + return ExprError(); + + // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. + return Owned(new (Context) UnaryExprOrTypeTraitExpr(ExprKind, E, + Context.getSizeType(), + OpLoc, R.getEnd())); +} + +/// ActOnUnaryExprOrTypeTraitExpr - Handle @c sizeof(type) and @c sizeof @c +/// expr and the same for @c alignof and @c __alignof +/// Note that the ArgRange is invalid if isType is false. +ExprResult +Sema::ActOnUnaryExprOrTypeTraitExpr(SourceLocation OpLoc, + UnaryExprOrTypeTrait ExprKind, bool isType, + void *TyOrEx, const SourceRange &ArgRange) { + // If error parsing type, ignore. + if (TyOrEx == 0) return ExprError(); + + if (isType) { + TypeSourceInfo *TInfo; + (void) GetTypeFromParser(ParsedType::getFromOpaquePtr(TyOrEx), &TInfo); + return CreateUnaryExprOrTypeTraitExpr(TInfo, OpLoc, ExprKind, ArgRange); + } + + Expr *ArgEx = (Expr *)TyOrEx; + ExprResult Result + = CreateUnaryExprOrTypeTraitExpr(ArgEx, OpLoc, ExprKind, + ArgEx->getSourceRange()); + + return move(Result); +} + +static QualType CheckRealImagOperand(Sema &S, ExprResult &V, SourceLocation Loc, + bool isReal) { + if (V.get()->isTypeDependent()) + return S.Context.DependentTy; + + // _Real and _Imag are only l-values for normal l-values. + if (V.get()->getObjectKind() != OK_Ordinary) { + V = S.DefaultLvalueConversion(V.take()); + if (V.isInvalid()) + return QualType(); + } + + // These operators return the element type of a complex type. + if (const ComplexType *CT = V.get()->getType()->getAs<ComplexType>()) + return CT->getElementType(); + + // Otherwise they pass through real integer and floating point types here. + if (V.get()->getType()->isArithmeticType()) + return V.get()->getType(); + + // Test for placeholders. + ExprResult PR = S.CheckPlaceholderExpr(V.get()); + if (PR.isInvalid()) return QualType(); + if (PR.get() != V.get()) { + V = move(PR); + return CheckRealImagOperand(S, V, Loc, isReal); + } + + // Reject anything else. + S.Diag(Loc, diag::err_realimag_invalid_type) << V.get()->getType() + << (isReal ? "__real" : "__imag"); + return QualType(); +} + + + +ExprResult +Sema::ActOnPostfixUnaryOp(Scope *S, SourceLocation OpLoc, + tok::TokenKind Kind, Expr *Input) { + UnaryOperatorKind Opc; + switch (Kind) { + default: assert(0 && "Unknown unary op!"); + case tok::plusplus: Opc = UO_PostInc; break; + case tok::minusminus: Opc = UO_PostDec; break; + } + + return BuildUnaryOp(S, OpLoc, Opc, Input); +} + +/// Expressions of certain arbitrary types are forbidden by C from +/// having l-value type. These are: +/// - 'void', but not qualified void +/// - function types +/// +/// The exact rule here is C99 6.3.2.1: +/// An lvalue is an expression with an object type or an incomplete +/// type other than void. +static bool IsCForbiddenLValueType(ASTContext &C, QualType T) { + return ((T->isVoidType() && !T.hasQualifiers()) || + T->isFunctionType()); +} + +ExprResult +Sema::ActOnArraySubscriptExpr(Scope *S, Expr *Base, SourceLocation LLoc, + Expr *Idx, SourceLocation RLoc) { + // Since this might be a postfix expression, get rid of ParenListExprs. + ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); + if (Result.isInvalid()) return ExprError(); + Base = Result.take(); + + Expr *LHSExp = Base, *RHSExp = Idx; + + if (getLangOptions().CPlusPlus && + (LHSExp->isTypeDependent() || RHSExp->isTypeDependent())) { + return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, + Context.DependentTy, + VK_LValue, OK_Ordinary, + RLoc)); + } + + if (getLangOptions().CPlusPlus && + (LHSExp->getType()->isRecordType() || + LHSExp->getType()->isEnumeralType() || + RHSExp->getType()->isRecordType() || + RHSExp->getType()->isEnumeralType())) { + return CreateOverloadedArraySubscriptExpr(LLoc, RLoc, Base, Idx); + } + + return CreateBuiltinArraySubscriptExpr(Base, LLoc, Idx, RLoc); +} + + +ExprResult +Sema::CreateBuiltinArraySubscriptExpr(Expr *Base, SourceLocation LLoc, + Expr *Idx, SourceLocation RLoc) { + Expr *LHSExp = Base; + Expr *RHSExp = Idx; + + // Perform default conversions. + if (!LHSExp->getType()->getAs<VectorType>()) { + ExprResult Result = DefaultFunctionArrayLvalueConversion(LHSExp); + if (Result.isInvalid()) + return ExprError(); + LHSExp = Result.take(); + } + ExprResult Result = DefaultFunctionArrayLvalueConversion(RHSExp); + if (Result.isInvalid()) + return ExprError(); + RHSExp = Result.take(); + + QualType LHSTy = LHSExp->getType(), RHSTy = RHSExp->getType(); + ExprValueKind VK = VK_LValue; + ExprObjectKind OK = OK_Ordinary; + + // C99 6.5.2.1p2: the expression e1[e2] is by definition precisely equivalent + // to the expression *((e1)+(e2)). This means the array "Base" may actually be + // in the subscript position. As a result, we need to derive the array base + // and index from the expression types. + Expr *BaseExpr, *IndexExpr; + QualType ResultType; + if (LHSTy->isDependentType() || RHSTy->isDependentType()) { + BaseExpr = LHSExp; + IndexExpr = RHSExp; + ResultType = Context.DependentTy; + } else if (const PointerType *PTy = LHSTy->getAs<PointerType>()) { + BaseExpr = LHSExp; + IndexExpr = RHSExp; + ResultType = PTy->getPointeeType(); + } else if (const PointerType *PTy = RHSTy->getAs<PointerType>()) { + // Handle the uncommon case of "123[Ptr]". + BaseExpr = RHSExp; + IndexExpr = LHSExp; + ResultType = PTy->getPointeeType(); + } else if (const ObjCObjectPointerType *PTy = + LHSTy->getAs<ObjCObjectPointerType>()) { + BaseExpr = LHSExp; + IndexExpr = RHSExp; + ResultType = PTy->getPointeeType(); + } else if (const ObjCObjectPointerType *PTy = + RHSTy->getAs<ObjCObjectPointerType>()) { + // Handle the uncommon case of "123[Ptr]". + BaseExpr = RHSExp; + IndexExpr = LHSExp; + ResultType = PTy->getPointeeType(); + } else if (const VectorType *VTy = LHSTy->getAs<VectorType>()) { + BaseExpr = LHSExp; // vectors: V[123] + IndexExpr = RHSExp; + VK = LHSExp->getValueKind(); + if (VK != VK_RValue) + OK = OK_VectorComponent; + + // FIXME: need to deal with const... + ResultType = VTy->getElementType(); + } else if (LHSTy->isArrayType()) { + // If we see an array that wasn't promoted by + // DefaultFunctionArrayLvalueConversion, it must be an array that + // wasn't promoted because of the C90 rule that doesn't + // allow promoting non-lvalue arrays. Warn, then + // force the promotion here. + Diag(LHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << + LHSExp->getSourceRange(); + LHSExp = ImpCastExprToType(LHSExp, Context.getArrayDecayedType(LHSTy), + CK_ArrayToPointerDecay).take(); + LHSTy = LHSExp->getType(); + + BaseExpr = LHSExp; + IndexExpr = RHSExp; + ResultType = LHSTy->getAs<PointerType>()->getPointeeType(); + } else if (RHSTy->isArrayType()) { + // Same as previous, except for 123[f().a] case + Diag(RHSExp->getLocStart(), diag::ext_subscript_non_lvalue) << + RHSExp->getSourceRange(); + RHSExp = ImpCastExprToType(RHSExp, Context.getArrayDecayedType(RHSTy), + CK_ArrayToPointerDecay).take(); + RHSTy = RHSExp->getType(); + + BaseExpr = RHSExp; + IndexExpr = LHSExp; + ResultType = RHSTy->getAs<PointerType>()->getPointeeType(); + } else { + return ExprError(Diag(LLoc, diag::err_typecheck_subscript_value) + << LHSExp->getSourceRange() << RHSExp->getSourceRange()); + } + // C99 6.5.2.1p1 + if (!IndexExpr->getType()->isIntegerType() && !IndexExpr->isTypeDependent()) + return ExprError(Diag(LLoc, diag::err_typecheck_subscript_not_integer) + << IndexExpr->getSourceRange()); + + if ((IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_S) || + IndexExpr->getType()->isSpecificBuiltinType(BuiltinType::Char_U)) + && !IndexExpr->isTypeDependent()) + Diag(LLoc, diag::warn_subscript_is_char) << IndexExpr->getSourceRange(); + + // C99 6.5.2.1p1: "shall have type "pointer to *object* type". Similarly, + // C++ [expr.sub]p1: The type "T" shall be a completely-defined object + // type. Note that Functions are not objects, and that (in C99 parlance) + // incomplete types are not object types. + if (ResultType->isFunctionType()) { + Diag(BaseExpr->getLocStart(), diag::err_subscript_function_type) + << ResultType << BaseExpr->getSourceRange(); + return ExprError(); + } + + if (ResultType->isVoidType() && !getLangOptions().CPlusPlus) { + // GNU extension: subscripting on pointer to void + Diag(LLoc, diag::ext_gnu_void_ptr) + << BaseExpr->getSourceRange(); + + // C forbids expressions of unqualified void type from being l-values. + // See IsCForbiddenLValueType. + if (!ResultType.hasQualifiers()) VK = VK_RValue; + } else if (!ResultType->isDependentType() && + RequireCompleteType(LLoc, ResultType, + PDiag(diag::err_subscript_incomplete_type) + << BaseExpr->getSourceRange())) + return ExprError(); + + // Diagnose bad cases where we step over interface counts. + if (ResultType->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { + Diag(LLoc, diag::err_subscript_nonfragile_interface) + << ResultType << BaseExpr->getSourceRange(); + return ExprError(); + } + + assert(VK == VK_RValue || LangOpts.CPlusPlus || + !IsCForbiddenLValueType(Context, ResultType)); + + return Owned(new (Context) ArraySubscriptExpr(LHSExp, RHSExp, + ResultType, VK, OK, RLoc)); +} + +/// Check an ext-vector component access expression. +/// +/// VK should be set in advance to the value kind of the base +/// expression. +static QualType +CheckExtVectorComponent(Sema &S, QualType baseType, ExprValueKind &VK, + SourceLocation OpLoc, const IdentifierInfo *CompName, + SourceLocation CompLoc) { + // FIXME: Share logic with ExtVectorElementExpr::containsDuplicateElements, + // see FIXME there. + // + // FIXME: This logic can be greatly simplified by splitting it along + // halving/not halving and reworking the component checking. + const ExtVectorType *vecType = baseType->getAs<ExtVectorType>(); + + // The vector accessor can't exceed the number of elements. + const char *compStr = CompName->getNameStart(); + + // This flag determines whether or not the component is one of the four + // special names that indicate a subset of exactly half the elements are + // to be selected. + bool HalvingSwizzle = false; + + // This flag determines whether or not CompName has an 's' char prefix, + // indicating that it is a string of hex values to be used as vector indices. + bool HexSwizzle = *compStr == 's' || *compStr == 'S'; + + bool HasRepeated = false; + bool HasIndex[16] = {}; + + int Idx; + + // Check that we've found one of the special components, or that the component + // names must come from the same set. + if (!strcmp(compStr, "hi") || !strcmp(compStr, "lo") || + !strcmp(compStr, "even") || !strcmp(compStr, "odd")) { + HalvingSwizzle = true; + } else if (!HexSwizzle && + (Idx = vecType->getPointAccessorIdx(*compStr)) != -1) { + do { + if (HasIndex[Idx]) HasRepeated = true; + HasIndex[Idx] = true; + compStr++; + } while (*compStr && (Idx = vecType->getPointAccessorIdx(*compStr)) != -1); + } else { + if (HexSwizzle) compStr++; + while ((Idx = vecType->getNumericAccessorIdx(*compStr)) != -1) { + if (HasIndex[Idx]) HasRepeated = true; + HasIndex[Idx] = true; + compStr++; + } + } + + if (!HalvingSwizzle && *compStr) { + // We didn't get to the end of the string. This means the component names + // didn't come from the same set *or* we encountered an illegal name. + S.Diag(OpLoc, diag::err_ext_vector_component_name_illegal) + << llvm::StringRef(compStr, 1) << SourceRange(CompLoc); + return QualType(); + } + + // Ensure no component accessor exceeds the width of the vector type it + // operates on. + if (!HalvingSwizzle) { + compStr = CompName->getNameStart(); + + if (HexSwizzle) + compStr++; + + while (*compStr) { + if (!vecType->isAccessorWithinNumElements(*compStr++)) { + S.Diag(OpLoc, diag::err_ext_vector_component_exceeds_length) + << baseType << SourceRange(CompLoc); + return QualType(); + } + } + } + + // The component accessor looks fine - now we need to compute the actual type. + // The vector type is implied by the component accessor. For example, + // vec4.b is a float, vec4.xy is a vec2, vec4.rgb is a vec3, etc. + // vec4.s0 is a float, vec4.s23 is a vec3, etc. + // vec4.hi, vec4.lo, vec4.e, and vec4.o all return vec2. + unsigned CompSize = HalvingSwizzle ? (vecType->getNumElements() + 1) / 2 + : CompName->getLength(); + if (HexSwizzle) + CompSize--; + + if (CompSize == 1) + return vecType->getElementType(); + + if (HasRepeated) VK = VK_RValue; + + QualType VT = S.Context.getExtVectorType(vecType->getElementType(), CompSize); + // Now look up the TypeDefDecl from the vector type. Without this, + // diagostics look bad. We want extended vector types to appear built-in. + for (unsigned i = 0, E = S.ExtVectorDecls.size(); i != E; ++i) { + if (S.ExtVectorDecls[i]->getUnderlyingType() == VT) + return S.Context.getTypedefType(S.ExtVectorDecls[i]); + } + return VT; // should never get here (a typedef type should always be found). +} + +static Decl *FindGetterSetterNameDeclFromProtocolList(const ObjCProtocolDecl*PDecl, + IdentifierInfo *Member, + const Selector &Sel, + ASTContext &Context) { + if (Member) + if (ObjCPropertyDecl *PD = PDecl->FindPropertyDeclaration(Member)) + return PD; + if (ObjCMethodDecl *OMD = PDecl->getInstanceMethod(Sel)) + return OMD; + + for (ObjCProtocolDecl::protocol_iterator I = PDecl->protocol_begin(), + E = PDecl->protocol_end(); I != E; ++I) { + if (Decl *D = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel, + Context)) + return D; + } + return 0; +} + +static Decl *FindGetterSetterNameDecl(const ObjCObjectPointerType *QIdTy, + IdentifierInfo *Member, + const Selector &Sel, + ASTContext &Context) { + // Check protocols on qualified interfaces. + Decl *GDecl = 0; + for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), + E = QIdTy->qual_end(); I != E; ++I) { + if (Member) + if (ObjCPropertyDecl *PD = (*I)->FindPropertyDeclaration(Member)) { + GDecl = PD; + break; + } + // Also must look for a getter or setter name which uses property syntax. + if (ObjCMethodDecl *OMD = (*I)->getInstanceMethod(Sel)) { + GDecl = OMD; + break; + } + } + if (!GDecl) { + for (ObjCObjectPointerType::qual_iterator I = QIdTy->qual_begin(), + E = QIdTy->qual_end(); I != E; ++I) { + // Search in the protocol-qualifier list of current protocol. + GDecl = FindGetterSetterNameDeclFromProtocolList(*I, Member, Sel, + Context); + if (GDecl) + return GDecl; + } + } + return GDecl; +} + +ExprResult +Sema::ActOnDependentMemberExpr(Expr *BaseExpr, QualType BaseType, + bool IsArrow, SourceLocation OpLoc, + const CXXScopeSpec &SS, + NamedDecl *FirstQualifierInScope, + const DeclarationNameInfo &NameInfo, + const TemplateArgumentListInfo *TemplateArgs) { + // Even in dependent contexts, try to diagnose base expressions with + // obviously wrong types, e.g.: + // + // T* t; + // t.f; + // + // In Obj-C++, however, the above expression is valid, since it could be + // accessing the 'f' property if T is an Obj-C interface. The extra check + // allows this, while still reporting an error if T is a struct pointer. + if (!IsArrow) { + const PointerType *PT = BaseType->getAs<PointerType>(); + if (PT && (!getLangOptions().ObjC1 || + PT->getPointeeType()->isRecordType())) { + assert(BaseExpr && "cannot happen with implicit member accesses"); + Diag(NameInfo.getLoc(), diag::err_typecheck_member_reference_struct_union) + << BaseType << BaseExpr->getSourceRange(); + return ExprError(); + } + } + + assert(BaseType->isDependentType() || + NameInfo.getName().isDependentName() || + isDependentScopeSpecifier(SS)); + + // Get the type being accessed in BaseType. If this is an arrow, the BaseExpr + // must have pointer type, and the accessed type is the pointee. + return Owned(CXXDependentScopeMemberExpr::Create(Context, BaseExpr, BaseType, + IsArrow, OpLoc, + SS.getWithLocInContext(Context), + FirstQualifierInScope, + NameInfo, TemplateArgs)); +} + +/// We know that the given qualified member reference points only to +/// declarations which do not belong to the static type of the base +/// expression. Diagnose the problem. +static void DiagnoseQualifiedMemberReference(Sema &SemaRef, + Expr *BaseExpr, + QualType BaseType, + const CXXScopeSpec &SS, + NamedDecl *rep, + const DeclarationNameInfo &nameInfo) { + // If this is an implicit member access, use a different set of + // diagnostics. + if (!BaseExpr) + return DiagnoseInstanceReference(SemaRef, SS, rep, nameInfo); + + SemaRef.Diag(nameInfo.getLoc(), diag::err_qualified_member_of_unrelated) + << SS.getRange() << rep << BaseType; +} + +// Check whether the declarations we found through a nested-name +// specifier in a member expression are actually members of the base +// type. The restriction here is: +// +// C++ [expr.ref]p2: +// ... In these cases, the id-expression shall name a +// member of the class or of one of its base classes. +// +// So it's perfectly legitimate for the nested-name specifier to name +// an unrelated class, and for us to find an overload set including +// decls from classes which are not superclasses, as long as the decl +// we actually pick through overload resolution is from a superclass. +bool Sema::CheckQualifiedMemberReference(Expr *BaseExpr, + QualType BaseType, + const CXXScopeSpec &SS, + const LookupResult &R) { + const RecordType *BaseRT = BaseType->getAs<RecordType>(); + if (!BaseRT) { + // We can't check this yet because the base type is still + // dependent. + assert(BaseType->isDependentType()); + return false; + } + CXXRecordDecl *BaseRecord = cast<CXXRecordDecl>(BaseRT->getDecl()); + + for (LookupResult::iterator I = R.begin(), E = R.end(); I != E; ++I) { + // If this is an implicit member reference and we find a + // non-instance member, it's not an error. + if (!BaseExpr && !(*I)->isCXXInstanceMember()) + return false; + + // Note that we use the DC of the decl, not the underlying decl. + DeclContext *DC = (*I)->getDeclContext(); + while (DC->isTransparentContext()) + DC = DC->getParent(); + + if (!DC->isRecord()) + continue; + + llvm::SmallPtrSet<CXXRecordDecl*,4> MemberRecord; + MemberRecord.insert(cast<CXXRecordDecl>(DC)->getCanonicalDecl()); + + if (!IsProvablyNotDerivedFrom(*this, BaseRecord, MemberRecord)) + return false; + } + + DiagnoseQualifiedMemberReference(*this, BaseExpr, BaseType, SS, + R.getRepresentativeDecl(), + R.getLookupNameInfo()); + return true; +} + +static bool +LookupMemberExprInRecord(Sema &SemaRef, LookupResult &R, + SourceRange BaseRange, const RecordType *RTy, + SourceLocation OpLoc, CXXScopeSpec &SS, + bool HasTemplateArgs) { + RecordDecl *RDecl = RTy->getDecl(); + if (SemaRef.RequireCompleteType(OpLoc, QualType(RTy, 0), + SemaRef.PDiag(diag::err_typecheck_incomplete_tag) + << BaseRange)) + return true; + + if (HasTemplateArgs) { + // LookupTemplateName doesn't expect these both to exist simultaneously. + QualType ObjectType = SS.isSet() ? QualType() : QualType(RTy, 0); + + bool MOUS; + SemaRef.LookupTemplateName(R, 0, SS, ObjectType, false, MOUS); + return false; + } + + DeclContext *DC = RDecl; + if (SS.isSet()) { + // If the member name was a qualified-id, look into the + // nested-name-specifier. + DC = SemaRef.computeDeclContext(SS, false); + + if (SemaRef.RequireCompleteDeclContext(SS, DC)) { + SemaRef.Diag(SS.getRange().getEnd(), diag::err_typecheck_incomplete_tag) + << SS.getRange() << DC; + return true; + } + + assert(DC && "Cannot handle non-computable dependent contexts in lookup"); + + if (!isa<TypeDecl>(DC)) { + SemaRef.Diag(R.getNameLoc(), diag::err_qualified_member_nonclass) + << DC << SS.getRange(); + return true; + } + } + + // The record definition is complete, now look up the member. + SemaRef.LookupQualifiedName(R, DC); + + if (!R.empty()) + return false; + + // We didn't find anything with the given name, so try to correct + // for typos. + DeclarationName Name = R.getLookupName(); + if (SemaRef.CorrectTypo(R, 0, &SS, DC, false, Sema::CTC_MemberLookup) && + !R.empty() && + (isa<ValueDecl>(*R.begin()) || isa<FunctionTemplateDecl>(*R.begin()))) { + SemaRef.Diag(R.getNameLoc(), diag::err_no_member_suggest) + << Name << DC << R.getLookupName() << SS.getRange() + << FixItHint::CreateReplacement(R.getNameLoc(), + R.getLookupName().getAsString()); + if (NamedDecl *ND = R.getAsSingle<NamedDecl>()) + SemaRef.Diag(ND->getLocation(), diag::note_previous_decl) + << ND->getDeclName(); + return false; + } else { + R.clear(); + R.setLookupName(Name); + } + + return false; +} + +ExprResult +Sema::BuildMemberReferenceExpr(Expr *Base, QualType BaseType, + SourceLocation OpLoc, bool IsArrow, + CXXScopeSpec &SS, + NamedDecl *FirstQualifierInScope, + const DeclarationNameInfo &NameInfo, + const TemplateArgumentListInfo *TemplateArgs) { + if (BaseType->isDependentType() || + (SS.isSet() && isDependentScopeSpecifier(SS))) + return ActOnDependentMemberExpr(Base, BaseType, + IsArrow, OpLoc, + SS, FirstQualifierInScope, + NameInfo, TemplateArgs); + + LookupResult R(*this, NameInfo, LookupMemberName); + + // Implicit member accesses. + if (!Base) { + QualType RecordTy = BaseType; + if (IsArrow) RecordTy = RecordTy->getAs<PointerType>()->getPointeeType(); + if (LookupMemberExprInRecord(*this, R, SourceRange(), + RecordTy->getAs<RecordType>(), + OpLoc, SS, TemplateArgs != 0)) + return ExprError(); + + // Explicit member accesses. + } else { + ExprResult BaseResult = Owned(Base); + ExprResult Result = + LookupMemberExpr(R, BaseResult, IsArrow, OpLoc, + SS, /*ObjCImpDecl*/ 0, TemplateArgs != 0); + + if (BaseResult.isInvalid()) + return ExprError(); + Base = BaseResult.take(); + + if (Result.isInvalid()) { + Owned(Base); + return ExprError(); + } + + if (Result.get()) + return move(Result); + + // LookupMemberExpr can modify Base, and thus change BaseType + BaseType = Base->getType(); + } + + return BuildMemberReferenceExpr(Base, BaseType, + OpLoc, IsArrow, SS, FirstQualifierInScope, + R, TemplateArgs); +} + +ExprResult +Sema::BuildMemberReferenceExpr(Expr *BaseExpr, QualType BaseExprType, + SourceLocation OpLoc, bool IsArrow, + const CXXScopeSpec &SS, + NamedDecl *FirstQualifierInScope, + LookupResult &R, + const TemplateArgumentListInfo *TemplateArgs, + bool SuppressQualifierCheck) { + QualType BaseType = BaseExprType; + if (IsArrow) { + assert(BaseType->isPointerType()); + BaseType = BaseType->getAs<PointerType>()->getPointeeType(); + } + R.setBaseObjectType(BaseType); + + const DeclarationNameInfo &MemberNameInfo = R.getLookupNameInfo(); + DeclarationName MemberName = MemberNameInfo.getName(); + SourceLocation MemberLoc = MemberNameInfo.getLoc(); + + if (R.isAmbiguous()) + return ExprError(); + + if (R.empty()) { + // Rederive where we looked up. + DeclContext *DC = (SS.isSet() + ? computeDeclContext(SS, false) + : BaseType->getAs<RecordType>()->getDecl()); + + Diag(R.getNameLoc(), diag::err_no_member) + << MemberName << DC + << (BaseExpr ? BaseExpr->getSourceRange() : SourceRange()); + return ExprError(); + } + + // Diagnose lookups that find only declarations from a non-base + // type. This is possible for either qualified lookups (which may + // have been qualified with an unrelated type) or implicit member + // expressions (which were found with unqualified lookup and thus + // may have come from an enclosing scope). Note that it's okay for + // lookup to find declarations from a non-base type as long as those + // aren't the ones picked by overload resolution. + if ((SS.isSet() || !BaseExpr || + (isa<CXXThisExpr>(BaseExpr) && + cast<CXXThisExpr>(BaseExpr)->isImplicit())) && + !SuppressQualifierCheck && + CheckQualifiedMemberReference(BaseExpr, BaseType, SS, R)) + return ExprError(); + + // Construct an unresolved result if we in fact got an unresolved + // result. + if (R.isOverloadedResult() || R.isUnresolvableResult()) { + // Suppress any lookup-related diagnostics; we'll do these when we + // pick a member. + R.suppressDiagnostics(); + + UnresolvedMemberExpr *MemExpr + = UnresolvedMemberExpr::Create(Context, R.isUnresolvableResult(), + BaseExpr, BaseExprType, + IsArrow, OpLoc, + SS.getWithLocInContext(Context), + MemberNameInfo, + TemplateArgs, R.begin(), R.end()); + + return Owned(MemExpr); + } + + assert(R.isSingleResult()); + DeclAccessPair FoundDecl = R.begin().getPair(); + NamedDecl *MemberDecl = R.getFoundDecl(); + + // FIXME: diagnose the presence of template arguments now. + + // If the decl being referenced had an error, return an error for this + // sub-expr without emitting another error, in order to avoid cascading + // error cases. + if (MemberDecl->isInvalidDecl()) + return ExprError(); + + // Handle the implicit-member-access case. + if (!BaseExpr) { + // If this is not an instance member, convert to a non-member access. + if (!MemberDecl->isCXXInstanceMember()) + return BuildDeclarationNameExpr(SS, R.getLookupNameInfo(), MemberDecl); + + SourceLocation Loc = R.getNameLoc(); + if (SS.getRange().isValid()) + Loc = SS.getRange().getBegin(); + BaseExpr = new (Context) CXXThisExpr(Loc, BaseExprType,/*isImplicit=*/true); + } + + bool ShouldCheckUse = true; + if (CXXMethodDecl *MD = dyn_cast<CXXMethodDecl>(MemberDecl)) { + // Don't diagnose the use of a virtual member function unless it's + // explicitly qualified. + if (MD->isVirtual() && !SS.isSet()) + ShouldCheckUse = false; + } + + // Check the use of this member. + if (ShouldCheckUse && DiagnoseUseOfDecl(MemberDecl, MemberLoc)) { + Owned(BaseExpr); + return ExprError(); + } + + // Perform a property load on the base regardless of whether we + // actually need it for the declaration. + if (BaseExpr->getObjectKind() == OK_ObjCProperty) { + ExprResult Result = ConvertPropertyForRValue(BaseExpr); + if (Result.isInvalid()) + return ExprError(); + BaseExpr = Result.take(); + } + + if (FieldDecl *FD = dyn_cast<FieldDecl>(MemberDecl)) + return BuildFieldReferenceExpr(*this, BaseExpr, IsArrow, + SS, FD, FoundDecl, MemberNameInfo); + + if (IndirectFieldDecl *FD = dyn_cast<IndirectFieldDecl>(MemberDecl)) + // We may have found a field within an anonymous union or struct + // (C++ [class.union]). + return BuildAnonymousStructUnionMemberReference(SS, MemberLoc, FD, + BaseExpr, OpLoc); + + if (VarDecl *Var = dyn_cast<VarDecl>(MemberDecl)) { + MarkDeclarationReferenced(MemberLoc, Var); + return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, + Var, FoundDecl, MemberNameInfo, + Var->getType().getNonReferenceType(), + VK_LValue, OK_Ordinary)); + } + + if (CXXMethodDecl *MemberFn = dyn_cast<CXXMethodDecl>(MemberDecl)) { + ExprValueKind valueKind; + QualType type; + if (MemberFn->isInstance()) { + valueKind = VK_RValue; + type = Context.BoundMemberTy; + } else { + valueKind = VK_LValue; + type = MemberFn->getType(); + } + + MarkDeclarationReferenced(MemberLoc, MemberDecl); + return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, + MemberFn, FoundDecl, MemberNameInfo, + type, valueKind, OK_Ordinary)); + } + assert(!isa<FunctionDecl>(MemberDecl) && "member function not C++ method?"); + + if (EnumConstantDecl *Enum = dyn_cast<EnumConstantDecl>(MemberDecl)) { + MarkDeclarationReferenced(MemberLoc, MemberDecl); + return Owned(BuildMemberExpr(Context, BaseExpr, IsArrow, SS, + Enum, FoundDecl, MemberNameInfo, + Enum->getType(), VK_RValue, OK_Ordinary)); + } + + Owned(BaseExpr); + + // We found something that we didn't expect. Complain. + if (isa<TypeDecl>(MemberDecl)) + Diag(MemberLoc, diag::err_typecheck_member_reference_type) + << MemberName << BaseType << int(IsArrow); + else + Diag(MemberLoc, diag::err_typecheck_member_reference_unknown) + << MemberName << BaseType << int(IsArrow); + + Diag(MemberDecl->getLocation(), diag::note_member_declared_here) + << MemberName; + R.suppressDiagnostics(); + return ExprError(); +} + +/// Given that normal member access failed on the given expression, +/// and given that the expression's type involves builtin-id or +/// builtin-Class, decide whether substituting in the redefinition +/// types would be profitable. The redefinition type is whatever +/// this translation unit tried to typedef to id/Class; we store +/// it to the side and then re-use it in places like this. +static bool ShouldTryAgainWithRedefinitionType(Sema &S, ExprResult &base) { + const ObjCObjectPointerType *opty + = base.get()->getType()->getAs<ObjCObjectPointerType>(); + if (!opty) return false; + + const ObjCObjectType *ty = opty->getObjectType(); + + QualType redef; + if (ty->isObjCId()) { + redef = S.Context.ObjCIdRedefinitionType; + } else if (ty->isObjCClass()) { + redef = S.Context.ObjCClassRedefinitionType; + } else { + return false; + } + + // Do the substitution as long as the redefinition type isn't just a + // possibly-qualified pointer to builtin-id or builtin-Class again. + opty = redef->getAs<ObjCObjectPointerType>(); + if (opty && !opty->getObjectType()->getInterface() != 0) + return false; + + base = S.ImpCastExprToType(base.take(), redef, CK_BitCast); + return true; +} + +/// Look up the given member of the given non-type-dependent +/// expression. This can return in one of two ways: +/// * If it returns a sentinel null-but-valid result, the caller will +/// assume that lookup was performed and the results written into +/// the provided structure. It will take over from there. +/// * Otherwise, the returned expression will be produced in place of +/// an ordinary member expression. +/// +/// The ObjCImpDecl bit is a gross hack that will need to be properly +/// fixed for ObjC++. +ExprResult +Sema::LookupMemberExpr(LookupResult &R, ExprResult &BaseExpr, + bool &IsArrow, SourceLocation OpLoc, + CXXScopeSpec &SS, + Decl *ObjCImpDecl, bool HasTemplateArgs) { + assert(BaseExpr.get() && "no base expression"); + + // Perform default conversions. + BaseExpr = DefaultFunctionArrayConversion(BaseExpr.take()); + + if (IsArrow) { + BaseExpr = DefaultLvalueConversion(BaseExpr.take()); + if (BaseExpr.isInvalid()) + return ExprError(); + } + + QualType BaseType = BaseExpr.get()->getType(); + assert(!BaseType->isDependentType()); + + DeclarationName MemberName = R.getLookupName(); + SourceLocation MemberLoc = R.getNameLoc(); + + // For later type-checking purposes, turn arrow accesses into dot + // accesses. The only access type we support that doesn't follow + // the C equivalence "a->b === (*a).b" is ObjC property accesses, + // and those never use arrows, so this is unaffected. + if (IsArrow) { + if (const PointerType *Ptr = BaseType->getAs<PointerType>()) + BaseType = Ptr->getPointeeType(); + else if (const ObjCObjectPointerType *Ptr + = BaseType->getAs<ObjCObjectPointerType>()) + BaseType = Ptr->getPointeeType(); + else if (BaseType->isRecordType()) { + // Recover from arrow accesses to records, e.g.: + // struct MyRecord foo; + // foo->bar + // This is actually well-formed in C++ if MyRecord has an + // overloaded operator->, but that should have been dealt with + // by now. + Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) + << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange() + << FixItHint::CreateReplacement(OpLoc, "."); + IsArrow = false; + } else if (BaseType == Context.BoundMemberTy) { + goto fail; + } else { + Diag(MemberLoc, diag::err_typecheck_member_reference_arrow) + << BaseType << BaseExpr.get()->getSourceRange(); + return ExprError(); + } + } + + // Handle field access to simple records. + if (const RecordType *RTy = BaseType->getAs<RecordType>()) { + if (LookupMemberExprInRecord(*this, R, BaseExpr.get()->getSourceRange(), + RTy, OpLoc, SS, HasTemplateArgs)) + return ExprError(); + + // Returning valid-but-null is how we indicate to the caller that + // the lookup result was filled in. + return Owned((Expr*) 0); + } + + // Handle ivar access to Objective-C objects. + if (const ObjCObjectType *OTy = BaseType->getAs<ObjCObjectType>()) { + IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); + + // There are three cases for the base type: + // - builtin id (qualified or unqualified) + // - builtin Class (qualified or unqualified) + // - an interface + ObjCInterfaceDecl *IDecl = OTy->getInterface(); + if (!IDecl) { + // There's an implicit 'isa' ivar on all objects. + // But we only actually find it this way on objects of type 'id', + // apparently. + if (OTy->isObjCId() && Member->isStr("isa")) + return Owned(new (Context) ObjCIsaExpr(BaseExpr.take(), IsArrow, MemberLoc, + Context.getObjCClassType())); + + if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) + return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, + ObjCImpDecl, HasTemplateArgs); + goto fail; + } + + ObjCInterfaceDecl *ClassDeclared; + ObjCIvarDecl *IV = IDecl->lookupInstanceVariable(Member, ClassDeclared); + + if (!IV) { + // Attempt to correct for typos in ivar names. + LookupResult Res(*this, R.getLookupName(), R.getNameLoc(), + LookupMemberName); + if (CorrectTypo(Res, 0, 0, IDecl, false, + IsArrow ? CTC_ObjCIvarLookup + : CTC_ObjCPropertyLookup) && + (IV = Res.getAsSingle<ObjCIvarDecl>())) { + Diag(R.getNameLoc(), + diag::err_typecheck_member_reference_ivar_suggest) + << IDecl->getDeclName() << MemberName << IV->getDeclName() + << FixItHint::CreateReplacement(R.getNameLoc(), + IV->getNameAsString()); + Diag(IV->getLocation(), diag::note_previous_decl) + << IV->getDeclName(); + } else { + Res.clear(); + Res.setLookupName(Member); + + Diag(MemberLoc, diag::err_typecheck_member_reference_ivar) + << IDecl->getDeclName() << MemberName + << BaseExpr.get()->getSourceRange(); + return ExprError(); + } + } + + // If the decl being referenced had an error, return an error for this + // sub-expr without emitting another error, in order to avoid cascading + // error cases. + if (IV->isInvalidDecl()) + return ExprError(); + + // Check whether we can reference this field. + if (DiagnoseUseOfDecl(IV, MemberLoc)) + return ExprError(); + if (IV->getAccessControl() != ObjCIvarDecl::Public && + IV->getAccessControl() != ObjCIvarDecl::Package) { + ObjCInterfaceDecl *ClassOfMethodDecl = 0; + if (ObjCMethodDecl *MD = getCurMethodDecl()) + ClassOfMethodDecl = MD->getClassInterface(); + else if (ObjCImpDecl && getCurFunctionDecl()) { + // Case of a c-function declared inside an objc implementation. + // FIXME: For a c-style function nested inside an objc implementation + // class, there is no implementation context available, so we pass + // down the context as argument to this routine. Ideally, this context + // need be passed down in the AST node and somehow calculated from the + // AST for a function decl. + if (ObjCImplementationDecl *IMPD = + dyn_cast<ObjCImplementationDecl>(ObjCImpDecl)) + ClassOfMethodDecl = IMPD->getClassInterface(); + else if (ObjCCategoryImplDecl* CatImplClass = + dyn_cast<ObjCCategoryImplDecl>(ObjCImpDecl)) + ClassOfMethodDecl = CatImplClass->getClassInterface(); + } + + if (IV->getAccessControl() == ObjCIvarDecl::Private) { + if (ClassDeclared != IDecl || + ClassOfMethodDecl != ClassDeclared) + Diag(MemberLoc, diag::error_private_ivar_access) + << IV->getDeclName(); + } else if (!IDecl->isSuperClassOf(ClassOfMethodDecl)) + // @protected + Diag(MemberLoc, diag::error_protected_ivar_access) + << IV->getDeclName(); + } + + return Owned(new (Context) ObjCIvarRefExpr(IV, IV->getType(), + MemberLoc, BaseExpr.take(), + IsArrow)); + } + + // Objective-C property access. + const ObjCObjectPointerType *OPT; + if (!IsArrow && (OPT = BaseType->getAs<ObjCObjectPointerType>())) { + // This actually uses the base as an r-value. + BaseExpr = DefaultLvalueConversion(BaseExpr.take()); + if (BaseExpr.isInvalid()) + return ExprError(); + + assert(Context.hasSameUnqualifiedType(BaseType, BaseExpr.get()->getType())); + + IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); + + const ObjCObjectType *OT = OPT->getObjectType(); + + // id, with and without qualifiers. + if (OT->isObjCId()) { + // Check protocols on qualified interfaces. + Selector Sel = PP.getSelectorTable().getNullarySelector(Member); + if (Decl *PMDecl = FindGetterSetterNameDecl(OPT, Member, Sel, Context)) { + if (ObjCPropertyDecl *PD = dyn_cast<ObjCPropertyDecl>(PMDecl)) { + // Check the use of this declaration + if (DiagnoseUseOfDecl(PD, MemberLoc)) + return ExprError(); + + return Owned(new (Context) ObjCPropertyRefExpr(PD, PD->getType(), + VK_LValue, + OK_ObjCProperty, + MemberLoc, + BaseExpr.take())); + } + + if (ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(PMDecl)) { + // Check the use of this method. + if (DiagnoseUseOfDecl(OMD, MemberLoc)) + return ExprError(); + Selector SetterSel = + SelectorTable::constructSetterName(PP.getIdentifierTable(), + PP.getSelectorTable(), Member); + ObjCMethodDecl *SMD = 0; + if (Decl *SDecl = FindGetterSetterNameDecl(OPT, /*Property id*/0, + SetterSel, Context)) + SMD = dyn_cast<ObjCMethodDecl>(SDecl); + QualType PType = OMD->getSendResultType(); + + ExprValueKind VK = VK_LValue; + if (!getLangOptions().CPlusPlus && + IsCForbiddenLValueType(Context, PType)) + VK = VK_RValue; + ExprObjectKind OK = (VK == VK_RValue ? OK_Ordinary : OK_ObjCProperty); + + return Owned(new (Context) ObjCPropertyRefExpr(OMD, SMD, PType, + VK, OK, + MemberLoc, BaseExpr.take())); + } + } + // Use of id.member can only be for a property reference. Do not + // use the 'id' redefinition in this case. + if (IsArrow && ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) + return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, + ObjCImpDecl, HasTemplateArgs); + + return ExprError(Diag(MemberLoc, diag::err_property_not_found) + << MemberName << BaseType); + } + + // 'Class', unqualified only. + if (OT->isObjCClass()) { + // Only works in a method declaration (??!). + ObjCMethodDecl *MD = getCurMethodDecl(); + if (!MD) { + if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) + return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, + ObjCImpDecl, HasTemplateArgs); + + goto fail; + } + + // Also must look for a getter name which uses property syntax. + Selector Sel = PP.getSelectorTable().getNullarySelector(Member); + ObjCInterfaceDecl *IFace = MD->getClassInterface(); + ObjCMethodDecl *Getter; + if ((Getter = IFace->lookupClassMethod(Sel))) { + // Check the use of this method. + if (DiagnoseUseOfDecl(Getter, MemberLoc)) + return ExprError(); + } else + Getter = IFace->lookupPrivateMethod(Sel, false); + // If we found a getter then this may be a valid dot-reference, we + // will look for the matching setter, in case it is needed. + Selector SetterSel = + SelectorTable::constructSetterName(PP.getIdentifierTable(), + PP.getSelectorTable(), Member); + ObjCMethodDecl *Setter = IFace->lookupClassMethod(SetterSel); + if (!Setter) { + // If this reference is in an @implementation, also check for 'private' + // methods. + Setter = IFace->lookupPrivateMethod(SetterSel, false); + } + // Look through local category implementations associated with the class. + if (!Setter) + Setter = IFace->getCategoryClassMethod(SetterSel); + + if (Setter && DiagnoseUseOfDecl(Setter, MemberLoc)) + return ExprError(); + + if (Getter || Setter) { + QualType PType; + + ExprValueKind VK = VK_LValue; + if (Getter) { + PType = Getter->getSendResultType(); + if (!getLangOptions().CPlusPlus && + IsCForbiddenLValueType(Context, PType)) + VK = VK_RValue; + } else { + // Get the expression type from Setter's incoming parameter. + PType = (*(Setter->param_end() -1))->getType(); + } + ExprObjectKind OK = (VK == VK_RValue ? OK_Ordinary : OK_ObjCProperty); + + // FIXME: we must check that the setter has property type. + return Owned(new (Context) ObjCPropertyRefExpr(Getter, Setter, + PType, VK, OK, + MemberLoc, BaseExpr.take())); + } + + if (ShouldTryAgainWithRedefinitionType(*this, BaseExpr)) + return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, + ObjCImpDecl, HasTemplateArgs); + + return ExprError(Diag(MemberLoc, diag::err_property_not_found) + << MemberName << BaseType); + } + + // Normal property access. + return HandleExprPropertyRefExpr(OPT, BaseExpr.get(), MemberName, MemberLoc, + SourceLocation(), QualType(), false); + } + + // Handle 'field access' to vectors, such as 'V.xx'. + if (BaseType->isExtVectorType()) { + // FIXME: this expr should store IsArrow. + IdentifierInfo *Member = MemberName.getAsIdentifierInfo(); + ExprValueKind VK = (IsArrow ? VK_LValue : BaseExpr.get()->getValueKind()); + QualType ret = CheckExtVectorComponent(*this, BaseType, VK, OpLoc, + Member, MemberLoc); + if (ret.isNull()) + return ExprError(); + + return Owned(new (Context) ExtVectorElementExpr(ret, VK, BaseExpr.take(), + *Member, MemberLoc)); + } + + // Adjust builtin-sel to the appropriate redefinition type if that's + // not just a pointer to builtin-sel again. + if (IsArrow && + BaseType->isSpecificBuiltinType(BuiltinType::ObjCSel) && + !Context.ObjCSelRedefinitionType->isObjCSelType()) { + BaseExpr = ImpCastExprToType(BaseExpr.take(), Context.ObjCSelRedefinitionType, + CK_BitCast); + return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, + ObjCImpDecl, HasTemplateArgs); + } + + // Failure cases. + fail: + + // Recover from dot accesses to pointers, e.g.: + // type *foo; + // foo.bar + // This is actually well-formed in two cases: + // - 'type' is an Objective C type + // - 'bar' is a pseudo-destructor name which happens to refer to + // the appropriate pointer type + if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { + if (!IsArrow && Ptr->getPointeeType()->isRecordType() && + MemberName.getNameKind() != DeclarationName::CXXDestructorName) { + Diag(OpLoc, diag::err_typecheck_member_reference_suggestion) + << BaseType << int(IsArrow) << BaseExpr.get()->getSourceRange() + << FixItHint::CreateReplacement(OpLoc, "->"); + + // Recurse as an -> access. + IsArrow = true; + return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, + ObjCImpDecl, HasTemplateArgs); + } + } + + // If the user is trying to apply -> or . to a function name, it's probably + // because they forgot parentheses to call that function. + bool TryCall = false; + bool Overloaded = false; + UnresolvedSet<8> AllOverloads; + if (const OverloadExpr *Overloads = dyn_cast<OverloadExpr>(BaseExpr.get())) { + AllOverloads.append(Overloads->decls_begin(), Overloads->decls_end()); + TryCall = true; + Overloaded = true; + } else if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(BaseExpr.get())) { + if (FunctionDecl* Fun = dyn_cast<FunctionDecl>(DeclRef->getDecl())) { + AllOverloads.addDecl(Fun); + TryCall = true; + } + } + + if (TryCall) { + // Plunder the overload set for something that would make the member + // expression valid. + UnresolvedSet<4> ViableOverloads; + bool HasViableZeroArgOverload = false; + for (OverloadExpr::decls_iterator it = AllOverloads.begin(), + DeclsEnd = AllOverloads.end(); it != DeclsEnd; ++it) { + // Our overload set may include TemplateDecls, which we'll ignore for the + // purposes of determining whether we can issue a '()' fixit. + if (const FunctionDecl *OverloadDecl = dyn_cast<FunctionDecl>(*it)) { + QualType ResultTy = OverloadDecl->getResultType(); + if ((!IsArrow && ResultTy->isRecordType()) || + (IsArrow && ResultTy->isPointerType() && + ResultTy->getPointeeType()->isRecordType())) { + ViableOverloads.addDecl(*it); + if (OverloadDecl->getMinRequiredArguments() == 0) { + HasViableZeroArgOverload = true; + } + } + } + } + + if (!HasViableZeroArgOverload || ViableOverloads.size() != 1) { + Diag(BaseExpr.get()->getExprLoc(), diag::err_member_reference_needs_call) + << (AllOverloads.size() > 1) << 0 + << BaseExpr.get()->getSourceRange(); + int ViableOverloadCount = ViableOverloads.size(); + int I; + for (I = 0; I < ViableOverloadCount; ++I) { + // FIXME: Magic number for max shown overloads stolen from + // OverloadCandidateSet::NoteCandidates. + if (I >= 4 && Diags.getShowOverloads() == Diagnostic::Ovl_Best) { + break; + } + Diag(ViableOverloads[I].getDecl()->getSourceRange().getBegin(), + diag::note_member_ref_possible_intended_overload); + } + if (I != ViableOverloadCount) { + Diag(BaseExpr.get()->getExprLoc(), diag::note_ovl_too_many_candidates) + << int(ViableOverloadCount - I); + } + return ExprError(); + } + } else { + // We don't have an expression that's convenient to get a Decl from, but we + // can at least check if the type is "function of 0 arguments which returns + // an acceptable type". + const FunctionType *Fun = NULL; + if (const PointerType *Ptr = BaseType->getAs<PointerType>()) { + if ((Fun = Ptr->getPointeeType()->getAs<FunctionType>())) { + TryCall = true; + } + } else if ((Fun = BaseType->getAs<FunctionType>())) { + TryCall = true; + } else if (BaseType == Context.BoundMemberTy) { + // Look for the bound-member type. If it's still overloaded, + // give up, although we probably should have fallen into the + // OverloadExpr case above if we actually have an overloaded + // bound member. + QualType fnType = Expr::findBoundMemberType(BaseExpr.get()); + if (!fnType.isNull()) { + TryCall = true; + Fun = fnType->castAs<FunctionType>(); + } + } + + if (TryCall) { + if (const FunctionProtoType *FPT = dyn_cast<FunctionProtoType>(Fun)) { + if (FPT->getNumArgs() == 0) { + QualType ResultTy = Fun->getResultType(); + TryCall = (!IsArrow && ResultTy->isRecordType()) || + (IsArrow && ResultTy->isPointerType() && + ResultTy->getPointeeType()->isRecordType()); + } + } + } + } + + if (TryCall) { + // At this point, we know BaseExpr looks like it's potentially callable with + // 0 arguments, and that it returns something of a reasonable type, so we + // can emit a fixit and carry on pretending that BaseExpr was actually a + // CallExpr. + SourceLocation ParenInsertionLoc = + PP.getLocForEndOfToken(BaseExpr.get()->getLocEnd()); + Diag(BaseExpr.get()->getExprLoc(), diag::err_member_reference_needs_call) + << int(Overloaded) << 1 + << BaseExpr.get()->getSourceRange() + << FixItHint::CreateInsertion(ParenInsertionLoc, "()"); + ExprResult NewBase = ActOnCallExpr(0, BaseExpr.take(), ParenInsertionLoc, + MultiExprArg(*this, 0, 0), + ParenInsertionLoc); + if (NewBase.isInvalid()) + return ExprError(); + BaseExpr = NewBase; + BaseExpr = DefaultFunctionArrayConversion(BaseExpr.take()); + return LookupMemberExpr(R, BaseExpr, IsArrow, OpLoc, SS, + ObjCImpDecl, HasTemplateArgs); + } + + Diag(MemberLoc, diag::err_typecheck_member_reference_struct_union) + << BaseType << BaseExpr.get()->getSourceRange(); + + return ExprError(); +} + +/// The main callback when the parser finds something like +/// expression . [nested-name-specifier] identifier +/// expression -> [nested-name-specifier] identifier +/// where 'identifier' encompasses a fairly broad spectrum of +/// possibilities, including destructor and operator references. +/// +/// \param OpKind either tok::arrow or tok::period +/// \param HasTrailingLParen whether the next token is '(', which +/// is used to diagnose mis-uses of special members that can +/// only be called +/// \param ObjCImpDecl the current ObjC @implementation decl; +/// this is an ugly hack around the fact that ObjC @implementations +/// aren't properly put in the context chain +ExprResult Sema::ActOnMemberAccessExpr(Scope *S, Expr *Base, + SourceLocation OpLoc, + tok::TokenKind OpKind, + CXXScopeSpec &SS, + UnqualifiedId &Id, + Decl *ObjCImpDecl, + bool HasTrailingLParen) { + if (SS.isSet() && SS.isInvalid()) + return ExprError(); + + // Warn about the explicit constructor calls Microsoft extension. + if (getLangOptions().Microsoft && + Id.getKind() == UnqualifiedId::IK_ConstructorName) + Diag(Id.getSourceRange().getBegin(), + diag::ext_ms_explicit_constructor_call); + + TemplateArgumentListInfo TemplateArgsBuffer; + + // Decompose the name into its component parts. + DeclarationNameInfo NameInfo; + const TemplateArgumentListInfo *TemplateArgs; + DecomposeUnqualifiedId(*this, Id, TemplateArgsBuffer, + NameInfo, TemplateArgs); + + DeclarationName Name = NameInfo.getName(); + bool IsArrow = (OpKind == tok::arrow); + + NamedDecl *FirstQualifierInScope + = (!SS.isSet() ? 0 : FindFirstQualifierInScope(S, + static_cast<NestedNameSpecifier*>(SS.getScopeRep()))); + + // This is a postfix expression, so get rid of ParenListExprs. + ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Base); + if (Result.isInvalid()) return ExprError(); + Base = Result.take(); + + if (Base->getType()->isDependentType() || Name.isDependentName() || + isDependentScopeSpecifier(SS)) { + Result = ActOnDependentMemberExpr(Base, Base->getType(), + IsArrow, OpLoc, + SS, FirstQualifierInScope, + NameInfo, TemplateArgs); + } else { + LookupResult R(*this, NameInfo, LookupMemberName); + ExprResult BaseResult = Owned(Base); + Result = LookupMemberExpr(R, BaseResult, IsArrow, OpLoc, + SS, ObjCImpDecl, TemplateArgs != 0); + if (BaseResult.isInvalid()) + return ExprError(); + Base = BaseResult.take(); + + if (Result.isInvalid()) { + Owned(Base); + return ExprError(); + } + + if (Result.get()) { + // The only way a reference to a destructor can be used is to + // immediately call it, which falls into this case. If the + // next token is not a '(', produce a diagnostic and build the + // call now. + if (!HasTrailingLParen && + Id.getKind() == UnqualifiedId::IK_DestructorName) + return DiagnoseDtorReference(NameInfo.getLoc(), Result.get()); + + return move(Result); + } + + Result = BuildMemberReferenceExpr(Base, Base->getType(), + OpLoc, IsArrow, SS, FirstQualifierInScope, + R, TemplateArgs); + } + + return move(Result); +} + +ExprResult Sema::BuildCXXDefaultArgExpr(SourceLocation CallLoc, + FunctionDecl *FD, + ParmVarDecl *Param) { + if (Param->hasUnparsedDefaultArg()) { + Diag(CallLoc, + diag::err_use_of_default_argument_to_function_declared_later) << + FD << cast<CXXRecordDecl>(FD->getDeclContext())->getDeclName(); + Diag(UnparsedDefaultArgLocs[Param], + diag::note_default_argument_declared_here); + return ExprError(); + } + + if (Param->hasUninstantiatedDefaultArg()) { + Expr *UninstExpr = Param->getUninstantiatedDefaultArg(); + + // Instantiate the expression. + MultiLevelTemplateArgumentList ArgList + = getTemplateInstantiationArgs(FD, 0, /*RelativeToPrimary=*/true); + + std::pair<const TemplateArgument *, unsigned> Innermost + = ArgList.getInnermost(); + InstantiatingTemplate Inst(*this, CallLoc, Param, Innermost.first, + Innermost.second); + + ExprResult Result; + { + // C++ [dcl.fct.default]p5: + // The names in the [default argument] expression are bound, and + // the semantic constraints are checked, at the point where the + // default argument expression appears. + ContextRAII SavedContext(*this, FD); + Result = SubstExpr(UninstExpr, ArgList); + } + if (Result.isInvalid()) + return ExprError(); + + // Check the expression as an initializer for the parameter. + InitializedEntity Entity + = InitializedEntity::InitializeParameter(Context, Param); + InitializationKind Kind + = InitializationKind::CreateCopy(Param->getLocation(), + /*FIXME:EqualLoc*/UninstExpr->getSourceRange().getBegin()); + Expr *ResultE = Result.takeAs<Expr>(); + + InitializationSequence InitSeq(*this, Entity, Kind, &ResultE, 1); + Result = InitSeq.Perform(*this, Entity, Kind, + MultiExprArg(*this, &ResultE, 1)); + if (Result.isInvalid()) + return ExprError(); + + // Build the default argument expression. + return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param, + Result.takeAs<Expr>())); + } + + // If the default expression creates temporaries, we need to + // push them to the current stack of expression temporaries so they'll + // be properly destroyed. + // FIXME: We should really be rebuilding the default argument with new + // bound temporaries; see the comment in PR5810. + for (unsigned i = 0, e = Param->getNumDefaultArgTemporaries(); i != e; ++i) { + CXXTemporary *Temporary = Param->getDefaultArgTemporary(i); + MarkDeclarationReferenced(Param->getDefaultArg()->getLocStart(), + const_cast<CXXDestructorDecl*>(Temporary->getDestructor())); + ExprTemporaries.push_back(Temporary); + } + + // We already type-checked the argument, so we know it works. + // Just mark all of the declarations in this potentially-evaluated expression + // as being "referenced". + MarkDeclarationsReferencedInExpr(Param->getDefaultArg()); + return Owned(CXXDefaultArgExpr::Create(Context, CallLoc, Param)); +} + +/// ConvertArgumentsForCall - Converts the arguments specified in +/// Args/NumArgs to the parameter types of the function FDecl with +/// function prototype Proto. Call is the call expression itself, and +/// Fn is the function expression. For a C++ member function, this +/// routine does not attempt to convert the object argument. Returns +/// true if the call is ill-formed. +bool +Sema::ConvertArgumentsForCall(CallExpr *Call, Expr *Fn, + FunctionDecl *FDecl, + const FunctionProtoType *Proto, + Expr **Args, unsigned NumArgs, + SourceLocation RParenLoc) { + // Bail out early if calling a builtin with custom typechecking. + // We don't need to do this in the + if (FDecl) + if (unsigned ID = FDecl->getBuiltinID()) + if (Context.BuiltinInfo.hasCustomTypechecking(ID)) + return false; + + // C99 6.5.2.2p7 - the arguments are implicitly converted, as if by + // assignment, to the types of the corresponding parameter, ... + unsigned NumArgsInProto = Proto->getNumArgs(); + bool Invalid = false; + + // If too few arguments are available (and we don't have default + // arguments for the remaining parameters), don't make the call. + if (NumArgs < NumArgsInProto) { + if (!FDecl || NumArgs < FDecl->getMinRequiredArguments()) + return Diag(RParenLoc, diag::err_typecheck_call_too_few_args) + << Fn->getType()->isBlockPointerType() + << NumArgsInProto << NumArgs << Fn->getSourceRange(); + Call->setNumArgs(Context, NumArgsInProto); + } + + // If too many are passed and not variadic, error on the extras and drop + // them. + if (NumArgs > NumArgsInProto) { + if (!Proto->isVariadic()) { + Diag(Args[NumArgsInProto]->getLocStart(), + diag::err_typecheck_call_too_many_args) + << Fn->getType()->isBlockPointerType() + << NumArgsInProto << NumArgs << Fn->getSourceRange() + << SourceRange(Args[NumArgsInProto]->getLocStart(), + Args[NumArgs-1]->getLocEnd()); + + // Emit the location of the prototype. + if (FDecl && !FDecl->getBuiltinID()) + Diag(FDecl->getLocStart(), + diag::note_typecheck_call_too_many_args) + << FDecl; + + // This deletes the extra arguments. + Call->setNumArgs(Context, NumArgsInProto); + return true; + } + } + llvm::SmallVector<Expr *, 8> AllArgs; + VariadicCallType CallType = + Proto->isVariadic() ? VariadicFunction : VariadicDoesNotApply; + if (Fn->getType()->isBlockPointerType()) + CallType = VariadicBlock; // Block + else if (isa<MemberExpr>(Fn)) + CallType = VariadicMethod; + Invalid = GatherArgumentsForCall(Call->getSourceRange().getBegin(), FDecl, + Proto, 0, Args, NumArgs, AllArgs, CallType); + if (Invalid) + return true; + unsigned TotalNumArgs = AllArgs.size(); + for (unsigned i = 0; i < TotalNumArgs; ++i) + Call->setArg(i, AllArgs[i]); + + return false; +} + +bool Sema::GatherArgumentsForCall(SourceLocation CallLoc, + FunctionDecl *FDecl, + const FunctionProtoType *Proto, + unsigned FirstProtoArg, + Expr **Args, unsigned NumArgs, + llvm::SmallVector<Expr *, 8> &AllArgs, + VariadicCallType CallType) { + unsigned NumArgsInProto = Proto->getNumArgs(); + unsigned NumArgsToCheck = NumArgs; + bool Invalid = false; + if (NumArgs != NumArgsInProto) + // Use default arguments for missing arguments + NumArgsToCheck = NumArgsInProto; + unsigned ArgIx = 0; + // Continue to check argument types (even if we have too few/many args). + for (unsigned i = FirstProtoArg; i != NumArgsToCheck; i++) { + QualType ProtoArgType = Proto->getArgType(i); + + Expr *Arg; + if (ArgIx < NumArgs) { + Arg = Args[ArgIx++]; + + if (RequireCompleteType(Arg->getSourceRange().getBegin(), + ProtoArgType, + PDiag(diag::err_call_incomplete_argument) + << Arg->getSourceRange())) + return true; + + // Pass the argument + ParmVarDecl *Param = 0; + if (FDecl && i < FDecl->getNumParams()) + Param = FDecl->getParamDecl(i); + + InitializedEntity Entity = + Param? InitializedEntity::InitializeParameter(Context, Param) + : InitializedEntity::InitializeParameter(Context, ProtoArgType); + ExprResult ArgE = PerformCopyInitialization(Entity, + SourceLocation(), + Owned(Arg)); + if (ArgE.isInvalid()) + return true; + + Arg = ArgE.takeAs<Expr>(); + } else { + ParmVarDecl *Param = FDecl->getParamDecl(i); + + ExprResult ArgExpr = + BuildCXXDefaultArgExpr(CallLoc, FDecl, Param); + if (ArgExpr.isInvalid()) + return true; + + Arg = ArgExpr.takeAs<Expr>(); + } + AllArgs.push_back(Arg); + } + + // If this is a variadic call, handle args passed through "...". + if (CallType != VariadicDoesNotApply) { + + // Assume that extern "C" functions with variadic arguments that + // return __unknown_anytype aren't *really* variadic. + if (Proto->getResultType() == Context.UnknownAnyTy && + FDecl && FDecl->isExternC()) { + for (unsigned i = ArgIx; i != NumArgs; ++i) { + ExprResult arg; + if (isa<ExplicitCastExpr>(Args[i]->IgnoreParens())) + arg = DefaultFunctionArrayLvalueConversion(Args[i]); + else + arg = DefaultVariadicArgumentPromotion(Args[i], CallType, FDecl); + Invalid |= arg.isInvalid(); + AllArgs.push_back(arg.take()); + } + + // Otherwise do argument promotion, (C99 6.5.2.2p7). + } else { + for (unsigned i = ArgIx; i != NumArgs; ++i) { + ExprResult Arg = DefaultVariadicArgumentPromotion(Args[i], CallType, FDecl); + Invalid |= Arg.isInvalid(); + AllArgs.push_back(Arg.take()); + } + } + } + return Invalid; +} + +/// Given a function expression of unknown-any type, try to rebuild it +/// to have a function type. +static ExprResult rebuildUnknownAnyFunction(Sema &S, Expr *fn); + +/// ActOnCallExpr - Handle a call to Fn with the specified array of arguments. +/// This provides the location of the left/right parens and a list of comma +/// locations. +ExprResult +Sema::ActOnCallExpr(Scope *S, Expr *Fn, SourceLocation LParenLoc, + MultiExprArg args, SourceLocation RParenLoc, + Expr *ExecConfig) { + unsigned NumArgs = args.size(); + + // Since this might be a postfix expression, get rid of ParenListExprs. + ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Fn); + if (Result.isInvalid()) return ExprError(); + Fn = Result.take(); + + Expr **Args = args.release(); + + if (getLangOptions().CPlusPlus) { + // If this is a pseudo-destructor expression, build the call immediately. + if (isa<CXXPseudoDestructorExpr>(Fn)) { + if (NumArgs > 0) { + // Pseudo-destructor calls should not have any arguments. + Diag(Fn->getLocStart(), diag::err_pseudo_dtor_call_with_args) + << FixItHint::CreateRemoval( + SourceRange(Args[0]->getLocStart(), + Args[NumArgs-1]->getLocEnd())); + + NumArgs = 0; + } + + return Owned(new (Context) CallExpr(Context, Fn, 0, 0, Context.VoidTy, + VK_RValue, RParenLoc)); + } + + // Determine whether this is a dependent call inside a C++ template, + // in which case we won't do any semantic analysis now. + // FIXME: Will need to cache the results of name lookup (including ADL) in + // Fn. + bool Dependent = false; + if (Fn->isTypeDependent()) + Dependent = true; + else if (Expr::hasAnyTypeDependentArguments(Args, NumArgs)) + Dependent = true; + + if (Dependent) { + if (ExecConfig) { + return Owned(new (Context) CUDAKernelCallExpr( + Context, Fn, cast<CallExpr>(ExecConfig), Args, NumArgs, + Context.DependentTy, VK_RValue, RParenLoc)); + } else { + return Owned(new (Context) CallExpr(Context, Fn, Args, NumArgs, + Context.DependentTy, VK_RValue, + RParenLoc)); + } + } + + // Determine whether this is a call to an object (C++ [over.call.object]). + if (Fn->getType()->isRecordType()) + return Owned(BuildCallToObjectOfClassType(S, Fn, LParenLoc, Args, NumArgs, + RParenLoc)); + + if (Fn->getType() == Context.UnknownAnyTy) { + ExprResult result = rebuildUnknownAnyFunction(*this, Fn); + if (result.isInvalid()) return ExprError(); + Fn = result.take(); + } + + if (Fn->getType() == Context.BoundMemberTy) { + return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, + RParenLoc); + } + } + + // Check for overloaded calls. This can happen even in C due to extensions. + if (Fn->getType() == Context.OverloadTy) { + OverloadExpr::FindResult find = OverloadExpr::find(Fn); + + // We aren't supposed to apply this logic if there's an '&' involved. + if (!find.IsAddressOfOperand) { + OverloadExpr *ovl = find.Expression; + if (isa<UnresolvedLookupExpr>(ovl)) { + UnresolvedLookupExpr *ULE = cast<UnresolvedLookupExpr>(ovl); + return BuildOverloadedCallExpr(S, Fn, ULE, LParenLoc, Args, NumArgs, + RParenLoc, ExecConfig); + } else { + return BuildCallToMemberFunction(S, Fn, LParenLoc, Args, NumArgs, + RParenLoc); + } + } + } + + // If we're directly calling a function, get the appropriate declaration. + + Expr *NakedFn = Fn->IgnoreParens(); + + NamedDecl *NDecl = 0; + if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(NakedFn)) + if (UnOp->getOpcode() == UO_AddrOf) + NakedFn = UnOp->getSubExpr()->IgnoreParens(); + + if (isa<DeclRefExpr>(NakedFn)) + NDecl = cast<DeclRefExpr>(NakedFn)->getDecl(); + else if (isa<MemberExpr>(NakedFn)) + NDecl = cast<MemberExpr>(NakedFn)->getMemberDecl(); + + return BuildResolvedCallExpr(Fn, NDecl, LParenLoc, Args, NumArgs, RParenLoc, + ExecConfig); +} + +ExprResult +Sema::ActOnCUDAExecConfigExpr(Scope *S, SourceLocation LLLLoc, + MultiExprArg execConfig, SourceLocation GGGLoc) { + FunctionDecl *ConfigDecl = Context.getcudaConfigureCallDecl(); + if (!ConfigDecl) + return ExprError(Diag(LLLLoc, diag::err_undeclared_var_use) + << "cudaConfigureCall"); + QualType ConfigQTy = ConfigDecl->getType(); + + DeclRefExpr *ConfigDR = new (Context) DeclRefExpr( + ConfigDecl, ConfigQTy, VK_LValue, LLLLoc); + + return ActOnCallExpr(S, ConfigDR, LLLLoc, execConfig, GGGLoc, 0); +} + +/// BuildResolvedCallExpr - Build a call to a resolved expression, +/// i.e. an expression not of \p OverloadTy. The expression should +/// unary-convert to an expression of function-pointer or +/// block-pointer type. +/// +/// \param NDecl the declaration being called, if available +ExprResult +Sema::BuildResolvedCallExpr(Expr *Fn, NamedDecl *NDecl, + SourceLocation LParenLoc, + Expr **Args, unsigned NumArgs, + SourceLocation RParenLoc, + Expr *Config) { + FunctionDecl *FDecl = dyn_cast_or_null<FunctionDecl>(NDecl); + + // Promote the function operand. + ExprResult Result = UsualUnaryConversions(Fn); + if (Result.isInvalid()) + return ExprError(); + Fn = Result.take(); + + // Make the call expr early, before semantic checks. This guarantees cleanup + // of arguments and function on error. + CallExpr *TheCall; + if (Config) { + TheCall = new (Context) CUDAKernelCallExpr(Context, Fn, + cast<CallExpr>(Config), + Args, NumArgs, + Context.BoolTy, + VK_RValue, + RParenLoc); + } else { + TheCall = new (Context) CallExpr(Context, Fn, + Args, NumArgs, + Context.BoolTy, + VK_RValue, + RParenLoc); + } + + unsigned BuiltinID = (FDecl ? FDecl->getBuiltinID() : 0); + + // Bail out early if calling a builtin with custom typechecking. + if (BuiltinID && Context.BuiltinInfo.hasCustomTypechecking(BuiltinID)) + return CheckBuiltinFunctionCall(BuiltinID, TheCall); + + retry: + const FunctionType *FuncT; + if (const PointerType *PT = Fn->getType()->getAs<PointerType>()) { + // C99 6.5.2.2p1 - "The expression that denotes the called function shall + // have type pointer to function". + FuncT = PT->getPointeeType()->getAs<FunctionType>(); + if (FuncT == 0) + return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) + << Fn->getType() << Fn->getSourceRange()); + } else if (const BlockPointerType *BPT = + Fn->getType()->getAs<BlockPointerType>()) { + FuncT = BPT->getPointeeType()->castAs<FunctionType>(); + } else { + // Handle calls to expressions of unknown-any type. + if (Fn->getType() == Context.UnknownAnyTy) { + ExprResult rewrite = rebuildUnknownAnyFunction(*this, Fn); + if (rewrite.isInvalid()) return ExprError(); + Fn = rewrite.take(); + TheCall->setCallee(Fn); + goto retry; + } + + return ExprError(Diag(LParenLoc, diag::err_typecheck_call_not_function) + << Fn->getType() << Fn->getSourceRange()); + } + + if (getLangOptions().CUDA) { + if (Config) { + // CUDA: Kernel calls must be to global functions + if (FDecl && !FDecl->hasAttr<CUDAGlobalAttr>()) + return ExprError(Diag(LParenLoc,diag::err_kern_call_not_global_function) + << FDecl->getName() << Fn->getSourceRange()); + + // CUDA: Kernel function must have 'void' return type + if (!FuncT->getResultType()->isVoidType()) + return ExprError(Diag(LParenLoc, diag::err_kern_type_not_void_return) + << Fn->getType() << Fn->getSourceRange()); + } + } + + // Check for a valid return type + if (CheckCallReturnType(FuncT->getResultType(), + Fn->getSourceRange().getBegin(), TheCall, + FDecl)) + return ExprError(); + + // We know the result type of the call, set it. + TheCall->setType(FuncT->getCallResultType(Context)); + TheCall->setValueKind(Expr::getValueKindForType(FuncT->getResultType())); + + if (const FunctionProtoType *Proto = dyn_cast<FunctionProtoType>(FuncT)) { + if (ConvertArgumentsForCall(TheCall, Fn, FDecl, Proto, Args, NumArgs, + RParenLoc)) + return ExprError(); + } else { + assert(isa<FunctionNoProtoType>(FuncT) && "Unknown FunctionType!"); + + if (FDecl) { + // Check if we have too few/too many template arguments, based + // on our knowledge of the function definition. + const FunctionDecl *Def = 0; + if (FDecl->hasBody(Def) && NumArgs != Def->param_size()) { + const FunctionProtoType *Proto + = Def->getType()->getAs<FunctionProtoType>(); + if (!Proto || !(Proto->isVariadic() && NumArgs >= Def->param_size())) + Diag(RParenLoc, diag::warn_call_wrong_number_of_arguments) + << (NumArgs > Def->param_size()) << FDecl << Fn->getSourceRange(); + } + + // If the function we're calling isn't a function prototype, but we have + // a function prototype from a prior declaratiom, use that prototype. + if (!FDecl->hasPrototype()) + Proto = FDecl->getType()->getAs<FunctionProtoType>(); + } + + // Promote the arguments (C99 6.5.2.2p6). + for (unsigned i = 0; i != NumArgs; i++) { + Expr *Arg = Args[i]; + + if (Proto && i < Proto->getNumArgs()) { + InitializedEntity Entity + = InitializedEntity::InitializeParameter(Context, + Proto->getArgType(i)); + ExprResult ArgE = PerformCopyInitialization(Entity, + SourceLocation(), + Owned(Arg)); + if (ArgE.isInvalid()) + return true; + + Arg = ArgE.takeAs<Expr>(); + + } else { + ExprResult ArgE = DefaultArgumentPromotion(Arg); + + if (ArgE.isInvalid()) + return true; + + Arg = ArgE.takeAs<Expr>(); + } + + if (RequireCompleteType(Arg->getSourceRange().getBegin(), + Arg->getType(), + PDiag(diag::err_call_incomplete_argument) + << Arg->getSourceRange())) + return ExprError(); + + TheCall->setArg(i, Arg); + } + } + + if (CXXMethodDecl *Method = dyn_cast_or_null<CXXMethodDecl>(FDecl)) + if (!Method->isStatic()) + return ExprError(Diag(LParenLoc, diag::err_member_call_without_object) + << Fn->getSourceRange()); + + // Check for sentinels + if (NDecl) + DiagnoseSentinelCalls(NDecl, LParenLoc, Args, NumArgs); + + // Do special checking on direct calls to functions. + if (FDecl) { + if (CheckFunctionCall(FDecl, TheCall)) + return ExprError(); + + if (BuiltinID) + return CheckBuiltinFunctionCall(BuiltinID, TheCall); + } else if (NDecl) { + if (CheckBlockCall(NDecl, TheCall)) + return ExprError(); + } + + return MaybeBindToTemporary(TheCall); +} + +ExprResult +Sema::ActOnCompoundLiteral(SourceLocation LParenLoc, ParsedType Ty, + SourceLocation RParenLoc, Expr *InitExpr) { + assert((Ty != 0) && "ActOnCompoundLiteral(): missing type"); + // FIXME: put back this assert when initializers are worked out. + //assert((InitExpr != 0) && "ActOnCompoundLiteral(): missing expression"); + + TypeSourceInfo *TInfo; + QualType literalType = GetTypeFromParser(Ty, &TInfo); + if (!TInfo) + TInfo = Context.getTrivialTypeSourceInfo(literalType); + + return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, InitExpr); +} + +ExprResult +Sema::BuildCompoundLiteralExpr(SourceLocation LParenLoc, TypeSourceInfo *TInfo, + SourceLocation RParenLoc, Expr *literalExpr) { + QualType literalType = TInfo->getType(); + + if (literalType->isArrayType()) { + if (RequireCompleteType(LParenLoc, Context.getBaseElementType(literalType), + PDiag(diag::err_illegal_decl_array_incomplete_type) + << SourceRange(LParenLoc, + literalExpr->getSourceRange().getEnd()))) + return ExprError(); + if (literalType->isVariableArrayType()) + return ExprError(Diag(LParenLoc, diag::err_variable_object_no_init) + << SourceRange(LParenLoc, literalExpr->getSourceRange().getEnd())); + } else if (!literalType->isDependentType() && + RequireCompleteType(LParenLoc, literalType, + PDiag(diag::err_typecheck_decl_incomplete_type) + << SourceRange(LParenLoc, + literalExpr->getSourceRange().getEnd()))) + return ExprError(); + + InitializedEntity Entity + = InitializedEntity::InitializeTemporary(literalType); + InitializationKind Kind + = InitializationKind::CreateCast(SourceRange(LParenLoc, RParenLoc), + /*IsCStyleCast=*/true); + InitializationSequence InitSeq(*this, Entity, Kind, &literalExpr, 1); + ExprResult Result = InitSeq.Perform(*this, Entity, Kind, + MultiExprArg(*this, &literalExpr, 1), + &literalType); + if (Result.isInvalid()) + return ExprError(); + literalExpr = Result.get(); + + bool isFileScope = getCurFunctionOrMethodDecl() == 0; + if (isFileScope) { // 6.5.2.5p3 + if (CheckForConstantInitializer(literalExpr, literalType)) + return ExprError(); + } + + // In C, compound literals are l-values for some reason. + ExprValueKind VK = getLangOptions().CPlusPlus ? VK_RValue : VK_LValue; + + return Owned(new (Context) CompoundLiteralExpr(LParenLoc, TInfo, literalType, + VK, literalExpr, isFileScope)); +} + +ExprResult +Sema::ActOnInitList(SourceLocation LBraceLoc, MultiExprArg initlist, + SourceLocation RBraceLoc) { + unsigned NumInit = initlist.size(); + Expr **InitList = initlist.release(); + + // Semantic analysis for initializers is done by ActOnDeclarator() and + // CheckInitializer() - it requires knowledge of the object being intialized. + + InitListExpr *E = new (Context) InitListExpr(Context, LBraceLoc, InitList, + NumInit, RBraceLoc); + E->setType(Context.VoidTy); // FIXME: just a place holder for now. + return Owned(E); +} + +/// Prepares for a scalar cast, performing all the necessary stages +/// except the final cast and returning the kind required. +static CastKind PrepareScalarCast(Sema &S, ExprResult &Src, QualType DestTy) { + // Both Src and Dest are scalar types, i.e. arithmetic or pointer. + // Also, callers should have filtered out the invalid cases with + // pointers. Everything else should be possible. + + QualType SrcTy = Src.get()->getType(); + if (S.Context.hasSameUnqualifiedType(SrcTy, DestTy)) + return CK_NoOp; + + switch (SrcTy->getScalarTypeKind()) { + case Type::STK_MemberPointer: + llvm_unreachable("member pointer type in C"); + + case Type::STK_Pointer: + switch (DestTy->getScalarTypeKind()) { + case Type::STK_Pointer: + return DestTy->isObjCObjectPointerType() ? + CK_AnyPointerToObjCPointerCast : + CK_BitCast; + case Type::STK_Bool: + return CK_PointerToBoolean; + case Type::STK_Integral: + return CK_PointerToIntegral; + case Type::STK_Floating: + case Type::STK_FloatingComplex: + case Type::STK_IntegralComplex: + case Type::STK_MemberPointer: + llvm_unreachable("illegal cast from pointer"); + } + break; + + case Type::STK_Bool: // casting from bool is like casting from an integer + case Type::STK_Integral: + switch (DestTy->getScalarTypeKind()) { + case Type::STK_Pointer: + if (Src.get()->isNullPointerConstant(S.Context, Expr::NPC_ValueDependentIsNull)) + return CK_NullToPointer; + return CK_IntegralToPointer; + case Type::STK_Bool: + return CK_IntegralToBoolean; + case Type::STK_Integral: + return CK_IntegralCast; + case Type::STK_Floating: + return CK_IntegralToFloating; + case Type::STK_IntegralComplex: + Src = S.ImpCastExprToType(Src.take(), DestTy->getAs<ComplexType>()->getElementType(), + CK_IntegralCast); + return CK_IntegralRealToComplex; + case Type::STK_FloatingComplex: + Src = S.ImpCastExprToType(Src.take(), DestTy->getAs<ComplexType>()->getElementType(), + CK_IntegralToFloating); + return CK_FloatingRealToComplex; + case Type::STK_MemberPointer: + llvm_unreachable("member pointer type in C"); + } + break; + + case Type::STK_Floating: + switch (DestTy->getScalarTypeKind()) { + case Type::STK_Floating: + return CK_FloatingCast; + case Type::STK_Bool: + return CK_FloatingToBoolean; + case Type::STK_Integral: + return CK_FloatingToIntegral; + case Type::STK_FloatingComplex: + Src = S.ImpCastExprToType(Src.take(), DestTy->getAs<ComplexType>()->getElementType(), + CK_FloatingCast); + return CK_FloatingRealToComplex; + case Type::STK_IntegralComplex: + Src = S.ImpCastExprToType(Src.take(), DestTy->getAs<ComplexType>()->getElementType(), + CK_FloatingToIntegral); + return CK_IntegralRealToComplex; + case Type::STK_Pointer: + llvm_unreachable("valid float->pointer cast?"); + case Type::STK_MemberPointer: + llvm_unreachable("member pointer type in C"); + } + break; + + case Type::STK_FloatingComplex: + switch (DestTy->getScalarTypeKind()) { + case Type::STK_FloatingComplex: + return CK_FloatingComplexCast; + case Type::STK_IntegralComplex: + return CK_FloatingComplexToIntegralComplex; + case Type::STK_Floating: { + QualType ET = SrcTy->getAs<ComplexType>()->getElementType(); + if (S.Context.hasSameType(ET, DestTy)) + return CK_FloatingComplexToReal; + Src = S.ImpCastExprToType(Src.take(), ET, CK_FloatingComplexToReal); + return CK_FloatingCast; + } + case Type::STK_Bool: + return CK_FloatingComplexToBoolean; + case Type::STK_Integral: + Src = S.ImpCastExprToType(Src.take(), SrcTy->getAs<ComplexType>()->getElementType(), + CK_FloatingComplexToReal); + return CK_FloatingToIntegral; + case Type::STK_Pointer: + llvm_unreachable("valid complex float->pointer cast?"); + case Type::STK_MemberPointer: + llvm_unreachable("member pointer type in C"); + } + break; + + case Type::STK_IntegralComplex: + switch (DestTy->getScalarTypeKind()) { + case Type::STK_FloatingComplex: + return CK_IntegralComplexToFloatingComplex; + case Type::STK_IntegralComplex: + return CK_IntegralComplexCast; + case Type::STK_Integral: { + QualType ET = SrcTy->getAs<ComplexType>()->getElementType(); + if (S.Context.hasSameType(ET, DestTy)) + return CK_IntegralComplexToReal; + Src = S.ImpCastExprToType(Src.take(), ET, CK_IntegralComplexToReal); + return CK_IntegralCast; + } + case Type::STK_Bool: + return CK_IntegralComplexToBoolean; + case Type::STK_Floating: + Src = S.ImpCastExprToType(Src.take(), SrcTy->getAs<ComplexType>()->getElementType(), + CK_IntegralComplexToReal); + return CK_IntegralToFloating; + case Type::STK_Pointer: + llvm_unreachable("valid complex int->pointer cast?"); + case Type::STK_MemberPointer: + llvm_unreachable("member pointer type in C"); + } + break; + } + + llvm_unreachable("Unhandled scalar cast"); + return CK_BitCast; +} + +/// CheckCastTypes - Check type constraints for casting between types. +ExprResult Sema::CheckCastTypes(SourceRange TyR, QualType castType, + Expr *castExpr, CastKind& Kind, ExprValueKind &VK, + CXXCastPath &BasePath, bool FunctionalStyle) { + if (castExpr->getType() == Context.UnknownAnyTy) + return checkUnknownAnyCast(TyR, castType, castExpr, Kind, VK, BasePath); + + if (getLangOptions().CPlusPlus) + return CXXCheckCStyleCast(SourceRange(TyR.getBegin(), + castExpr->getLocEnd()), + castType, VK, castExpr, Kind, BasePath, + FunctionalStyle); + + assert(!castExpr->getType()->isPlaceholderType()); + + // We only support r-value casts in C. + VK = VK_RValue; + + // C99 6.5.4p2: the cast type needs to be void or scalar and the expression + // type needs to be scalar. + if (castType->isVoidType()) { + // We don't necessarily do lvalue-to-rvalue conversions on this. + ExprResult castExprRes = IgnoredValueConversions(castExpr); + if (castExprRes.isInvalid()) + return ExprError(); + castExpr = castExprRes.take(); + + // Cast to void allows any expr type. + Kind = CK_ToVoid; + return Owned(castExpr); + } + + ExprResult castExprRes = DefaultFunctionArrayLvalueConversion(castExpr); + if (castExprRes.isInvalid()) + return ExprError(); + castExpr = castExprRes.take(); + + if (RequireCompleteType(TyR.getBegin(), castType, + diag::err_typecheck_cast_to_incomplete)) + return ExprError(); + + if (!castType->isScalarType() && !castType->isVectorType()) { + if (Context.hasSameUnqualifiedType(castType, castExpr->getType()) && + (castType->isStructureType() || castType->isUnionType())) { + // GCC struct/union extension: allow cast to self. + // FIXME: Check that the cast destination type is complete. + Diag(TyR.getBegin(), diag::ext_typecheck_cast_nonscalar) + << castType << castExpr->getSourceRange(); + Kind = CK_NoOp; + return Owned(castExpr); + } + + if (castType->isUnionType()) { + // GCC cast to union extension + RecordDecl *RD = castType->getAs<RecordType>()->getDecl(); + RecordDecl::field_iterator Field, FieldEnd; + for (Field = RD->field_begin(), FieldEnd = RD->field_end(); + Field != FieldEnd; ++Field) { + if (Context.hasSameUnqualifiedType(Field->getType(), + castExpr->getType()) && + !Field->isUnnamedBitfield()) { + Diag(TyR.getBegin(), diag::ext_typecheck_cast_to_union) + << castExpr->getSourceRange(); + break; + } + } + if (Field == FieldEnd) { + Diag(TyR.getBegin(), diag::err_typecheck_cast_to_union_no_type) + << castExpr->getType() << castExpr->getSourceRange(); + return ExprError(); + } + Kind = CK_ToUnion; + return Owned(castExpr); + } + + // Reject any other conversions to non-scalar types. + Diag(TyR.getBegin(), diag::err_typecheck_cond_expect_scalar) + << castType << castExpr->getSourceRange(); + return ExprError(); + } + + // The type we're casting to is known to be a scalar or vector. + + // Require the operand to be a scalar or vector. + if (!castExpr->getType()->isScalarType() && + !castExpr->getType()->isVectorType()) { + Diag(castExpr->getLocStart(), + diag::err_typecheck_expect_scalar_operand) + << castExpr->getType() << castExpr->getSourceRange(); + return ExprError(); + } + + if (castType->isExtVectorType()) + return CheckExtVectorCast(TyR, castType, castExpr, Kind); + + if (castType->isVectorType()) { + if (castType->getAs<VectorType>()->getVectorKind() == + VectorType::AltiVecVector && + (castExpr->getType()->isIntegerType() || + castExpr->getType()->isFloatingType())) { + Kind = CK_VectorSplat; + return Owned(castExpr); + } else if (CheckVectorCast(TyR, castType, castExpr->getType(), Kind)) { + return ExprError(); + } else + return Owned(castExpr); + } + if (castExpr->getType()->isVectorType()) { + if (CheckVectorCast(TyR, castExpr->getType(), castType, Kind)) + return ExprError(); + else + return Owned(castExpr); + } + + // The source and target types are both scalars, i.e. + // - arithmetic types (fundamental, enum, and complex) + // - all kinds of pointers + // Note that member pointers were filtered out with C++, above. + + if (isa<ObjCSelectorExpr>(castExpr)) { + Diag(castExpr->getLocStart(), diag::err_cast_selector_expr); + return ExprError(); + } + + // If either type is a pointer, the other type has to be either an + // integer or a pointer. + if (!castType->isArithmeticType()) { + QualType castExprType = castExpr->getType(); + if (!castExprType->isIntegralType(Context) && + castExprType->isArithmeticType()) { + Diag(castExpr->getLocStart(), + diag::err_cast_pointer_from_non_pointer_int) + << castExprType << castExpr->getSourceRange(); + return ExprError(); + } + } else if (!castExpr->getType()->isArithmeticType()) { + if (!castType->isIntegralType(Context) && castType->isArithmeticType()) { + Diag(castExpr->getLocStart(), diag::err_cast_pointer_to_non_pointer_int) + << castType << castExpr->getSourceRange(); + return ExprError(); + } + } + + castExprRes = Owned(castExpr); + Kind = PrepareScalarCast(*this, castExprRes, castType); + if (castExprRes.isInvalid()) + return ExprError(); + castExpr = castExprRes.take(); + + if (Kind == CK_BitCast) + CheckCastAlign(castExpr, castType, TyR); + + return Owned(castExpr); +} + +bool Sema::CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, + CastKind &Kind) { + assert(VectorTy->isVectorType() && "Not a vector type!"); + + if (Ty->isVectorType() || Ty->isIntegerType()) { + if (Context.getTypeSize(VectorTy) != Context.getTypeSize(Ty)) + return Diag(R.getBegin(), + Ty->isVectorType() ? + diag::err_invalid_conversion_between_vectors : + diag::err_invalid_conversion_between_vector_and_integer) + << VectorTy << Ty << R; + } else + return Diag(R.getBegin(), + diag::err_invalid_conversion_between_vector_and_scalar) + << VectorTy << Ty << R; + + Kind = CK_BitCast; + return false; +} + +ExprResult Sema::CheckExtVectorCast(SourceRange R, QualType DestTy, + Expr *CastExpr, CastKind &Kind) { + assert(DestTy->isExtVectorType() && "Not an extended vector type!"); + + QualType SrcTy = CastExpr->getType(); + + // If SrcTy is a VectorType, the total size must match to explicitly cast to + // an ExtVectorType. + if (SrcTy->isVectorType()) { + if (Context.getTypeSize(DestTy) != Context.getTypeSize(SrcTy)) { + Diag(R.getBegin(),diag::err_invalid_conversion_between_ext_vectors) + << DestTy << SrcTy << R; + return ExprError(); + } + Kind = CK_BitCast; + return Owned(CastExpr); + } + + // All non-pointer scalars can be cast to ExtVector type. The appropriate + // conversion will take place first from scalar to elt type, and then + // splat from elt type to vector. + if (SrcTy->isPointerType()) + return Diag(R.getBegin(), + diag::err_invalid_conversion_between_vector_and_scalar) + << DestTy << SrcTy << R; + + QualType DestElemTy = DestTy->getAs<ExtVectorType>()->getElementType(); + ExprResult CastExprRes = Owned(CastExpr); + CastKind CK = PrepareScalarCast(*this, CastExprRes, DestElemTy); + if (CastExprRes.isInvalid()) + return ExprError(); + CastExpr = ImpCastExprToType(CastExprRes.take(), DestElemTy, CK).take(); + + Kind = CK_VectorSplat; + return Owned(CastExpr); +} + +ExprResult +Sema::ActOnCastExpr(Scope *S, SourceLocation LParenLoc, ParsedType Ty, + SourceLocation RParenLoc, Expr *castExpr) { + assert((Ty != 0) && (castExpr != 0) && + "ActOnCastExpr(): missing type or expr"); + + TypeSourceInfo *castTInfo; + QualType castType = GetTypeFromParser(Ty, &castTInfo); + if (!castTInfo) + castTInfo = Context.getTrivialTypeSourceInfo(castType); + + // If the Expr being casted is a ParenListExpr, handle it specially. + if (isa<ParenListExpr>(castExpr)) + return ActOnCastOfParenListExpr(S, LParenLoc, RParenLoc, castExpr, + castTInfo); + + return BuildCStyleCastExpr(LParenLoc, castTInfo, RParenLoc, castExpr); +} + +ExprResult +Sema::BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, + SourceLocation RParenLoc, Expr *castExpr) { + CastKind Kind = CK_Invalid; + ExprValueKind VK = VK_RValue; + CXXCastPath BasePath; + ExprResult CastResult = + CheckCastTypes(SourceRange(LParenLoc, RParenLoc), Ty->getType(), castExpr, + Kind, VK, BasePath); + if (CastResult.isInvalid()) + return ExprError(); + castExpr = CastResult.take(); + + return Owned(CStyleCastExpr::Create(Context, + Ty->getType().getNonLValueExprType(Context), + VK, Kind, castExpr, &BasePath, Ty, + LParenLoc, RParenLoc)); +} + +/// This is not an AltiVec-style cast, so turn the ParenListExpr into a sequence +/// of comma binary operators. +ExprResult +Sema::MaybeConvertParenListExprToParenExpr(Scope *S, Expr *expr) { + ParenListExpr *E = dyn_cast<ParenListExpr>(expr); + if (!E) + return Owned(expr); + + ExprResult Result(E->getExpr(0)); + + for (unsigned i = 1, e = E->getNumExprs(); i != e && !Result.isInvalid(); ++i) + Result = ActOnBinOp(S, E->getExprLoc(), tok::comma, Result.get(), + E->getExpr(i)); + + if (Result.isInvalid()) return ExprError(); + + return ActOnParenExpr(E->getLParenLoc(), E->getRParenLoc(), Result.get()); +} + +ExprResult +Sema::ActOnCastOfParenListExpr(Scope *S, SourceLocation LParenLoc, + SourceLocation RParenLoc, Expr *Op, + TypeSourceInfo *TInfo) { + ParenListExpr *PE = cast<ParenListExpr>(Op); + QualType Ty = TInfo->getType(); + bool isVectorLiteral = false; + + // Check for an altivec or OpenCL literal, + // i.e. all the elements are integer constants. + if (getLangOptions().AltiVec && Ty->isVectorType()) { + if (PE->getNumExprs() == 0) { + Diag(PE->getExprLoc(), diag::err_altivec_empty_initializer); + return ExprError(); + } + if (PE->getNumExprs() == 1) { + if (!PE->getExpr(0)->getType()->isVectorType()) + isVectorLiteral = true; + } + else + isVectorLiteral = true; + } + + // If this is a vector initializer, '(' type ')' '(' init, ..., init ')' + // then handle it as such. + if (isVectorLiteral) { + llvm::SmallVector<Expr *, 8> initExprs; + // '(...)' form of vector initialization in AltiVec: the number of + // initializers must be one or must match the size of the vector. + // If a single value is specified in the initializer then it will be + // replicated to all the components of the vector + if (Ty->getAs<VectorType>()->getVectorKind() == + VectorType::AltiVecVector) { + unsigned numElems = Ty->getAs<VectorType>()->getNumElements(); + // The number of initializers must be one or must match the size of the + // vector. If a single value is specified in the initializer then it will + // be replicated to all the components of the vector + if (PE->getNumExprs() == 1) { + QualType ElemTy = Ty->getAs<VectorType>()->getElementType(); + ExprResult Literal = Owned(PE->getExpr(0)); + Literal = ImpCastExprToType(Literal.take(), ElemTy, + PrepareScalarCast(*this, Literal, ElemTy)); + return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Literal.take()); + } + else if (PE->getNumExprs() < numElems) { + Diag(PE->getExprLoc(), + diag::err_incorrect_number_of_vector_initializers); + return ExprError(); + } + else + for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) + initExprs.push_back(PE->getExpr(i)); + } + else + for (unsigned i = 0, e = PE->getNumExprs(); i != e; ++i) + initExprs.push_back(PE->getExpr(i)); + + // FIXME: This means that pretty-printing the final AST will produce curly + // braces instead of the original commas. + InitListExpr *E = new (Context) InitListExpr(Context, LParenLoc, + &initExprs[0], + initExprs.size(), RParenLoc); + E->setType(Ty); + return BuildCompoundLiteralExpr(LParenLoc, TInfo, RParenLoc, E); + } else { + // This is not an AltiVec-style cast, so turn the ParenListExpr into a + // sequence of BinOp comma operators. + ExprResult Result = MaybeConvertParenListExprToParenExpr(S, Op); + if (Result.isInvalid()) return ExprError(); + return BuildCStyleCastExpr(LParenLoc, TInfo, RParenLoc, Result.take()); + } +} + +ExprResult Sema::ActOnParenOrParenListExpr(SourceLocation L, + SourceLocation R, + MultiExprArg Val, + ParsedType TypeOfCast) { + unsigned nexprs = Val.size(); + Expr **exprs = reinterpret_cast<Expr**>(Val.release()); + assert((exprs != 0) && "ActOnParenOrParenListExpr() missing expr list"); + Expr *expr; + if (nexprs == 1 && TypeOfCast && !TypeIsVectorType(TypeOfCast)) + expr = new (Context) ParenExpr(L, R, exprs[0]); + else + expr = new (Context) ParenListExpr(Context, L, exprs, nexprs, R); + return Owned(expr); +} + +/// \brief Emit a specialized diagnostic when one expression is a null pointer +/// constant and the other is not a pointer. +bool Sema::DiagnoseConditionalForNull(Expr *LHS, Expr *RHS, + SourceLocation QuestionLoc) { + Expr *NullExpr = LHS; + Expr *NonPointerExpr = RHS; + Expr::NullPointerConstantKind NullKind = + NullExpr->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNotNull); + + if (NullKind == Expr::NPCK_NotNull) { + NullExpr = RHS; + NonPointerExpr = LHS; + NullKind = + NullExpr->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNotNull); + } + + if (NullKind == Expr::NPCK_NotNull) + return false; + + if (NullKind == Expr::NPCK_ZeroInteger) { + // In this case, check to make sure that we got here from a "NULL" + // string in the source code. + NullExpr = NullExpr->IgnoreParenImpCasts(); + SourceLocation loc = NullExpr->getExprLoc(); + if (!findMacroSpelling(loc, "NULL")) + return false; + } + + int DiagType = (NullKind == Expr::NPCK_CXX0X_nullptr); + Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands_null) + << NonPointerExpr->getType() << DiagType + << NonPointerExpr->getSourceRange(); + return true; +} + +/// Note that lhs is not null here, even if this is the gnu "x ?: y" extension. +/// In that case, lhs = cond. +/// C99 6.5.15 +QualType Sema::CheckConditionalOperands(ExprResult &Cond, ExprResult &LHS, ExprResult &RHS, + ExprValueKind &VK, ExprObjectKind &OK, + SourceLocation QuestionLoc) { + + ExprResult lhsResult = CheckPlaceholderExpr(LHS.get()); + if (!lhsResult.isUsable()) return QualType(); + LHS = move(lhsResult); + + ExprResult rhsResult = CheckPlaceholderExpr(RHS.get()); + if (!rhsResult.isUsable()) return QualType(); + RHS = move(rhsResult); + + // C++ is sufficiently different to merit its own checker. + if (getLangOptions().CPlusPlus) + return CXXCheckConditionalOperands(Cond, LHS, RHS, VK, OK, QuestionLoc); + + VK = VK_RValue; + OK = OK_Ordinary; + + Cond = UsualUnaryConversions(Cond.take()); + if (Cond.isInvalid()) + return QualType(); + LHS = UsualUnaryConversions(LHS.take()); + if (LHS.isInvalid()) + return QualType(); + RHS = UsualUnaryConversions(RHS.take()); + if (RHS.isInvalid()) + return QualType(); + + QualType CondTy = Cond.get()->getType(); + QualType LHSTy = LHS.get()->getType(); + QualType RHSTy = RHS.get()->getType(); + + // first, check the condition. + if (!CondTy->isScalarType()) { // C99 6.5.15p2 + // OpenCL: Sec 6.3.i says the condition is allowed to be a vector or scalar. + // Throw an error if its not either. + if (getLangOptions().OpenCL) { + if (!CondTy->isVectorType()) { + Diag(Cond.get()->getLocStart(), + diag::err_typecheck_cond_expect_scalar_or_vector) + << CondTy; + return QualType(); + } + } + else { + Diag(Cond.get()->getLocStart(), diag::err_typecheck_cond_expect_scalar) + << CondTy; + return QualType(); + } + } + + // Now check the two expressions. + if (LHSTy->isVectorType() || RHSTy->isVectorType()) + return CheckVectorOperands(QuestionLoc, LHS, RHS); + + // OpenCL: If the condition is a vector, and both operands are scalar, + // attempt to implicity convert them to the vector type to act like the + // built in select. + if (getLangOptions().OpenCL && CondTy->isVectorType()) { + // Both operands should be of scalar type. + if (!LHSTy->isScalarType()) { + Diag(LHS.get()->getLocStart(), diag::err_typecheck_cond_expect_scalar) + << CondTy; + return QualType(); + } + if (!RHSTy->isScalarType()) { + Diag(RHS.get()->getLocStart(), diag::err_typecheck_cond_expect_scalar) + << CondTy; + return QualType(); + } + // Implicity convert these scalars to the type of the condition. + LHS = ImpCastExprToType(LHS.take(), CondTy, CK_IntegralCast); + RHS = ImpCastExprToType(RHS.take(), CondTy, CK_IntegralCast); + } + + // If both operands have arithmetic type, do the usual arithmetic conversions + // to find a common type: C99 6.5.15p3,5. + if (LHSTy->isArithmeticType() && RHSTy->isArithmeticType()) { + UsualArithmeticConversions(LHS, RHS); + if (LHS.isInvalid() || RHS.isInvalid()) + return QualType(); + return LHS.get()->getType(); + } + + // If both operands are the same structure or union type, the result is that + // type. + if (const RecordType *LHSRT = LHSTy->getAs<RecordType>()) { // C99 6.5.15p3 + if (const RecordType *RHSRT = RHSTy->getAs<RecordType>()) + if (LHSRT->getDecl() == RHSRT->getDecl()) + // "If both the operands have structure or union type, the result has + // that type." This implies that CV qualifiers are dropped. + return LHSTy.getUnqualifiedType(); + // FIXME: Type of conditional expression must be complete in C mode. + } + + // C99 6.5.15p5: "If both operands have void type, the result has void type." + // The following || allows only one side to be void (a GCC-ism). + if (LHSTy->isVoidType() || RHSTy->isVoidType()) { + if (!LHSTy->isVoidType()) + Diag(RHS.get()->getLocStart(), diag::ext_typecheck_cond_one_void) + << RHS.get()->getSourceRange(); + if (!RHSTy->isVoidType()) + Diag(LHS.get()->getLocStart(), diag::ext_typecheck_cond_one_void) + << LHS.get()->getSourceRange(); + LHS = ImpCastExprToType(LHS.take(), Context.VoidTy, CK_ToVoid); + RHS = ImpCastExprToType(RHS.take(), Context.VoidTy, CK_ToVoid); + return Context.VoidTy; + } + // C99 6.5.15p6 - "if one operand is a null pointer constant, the result has + // the type of the other operand." + if ((LHSTy->isAnyPointerType() || LHSTy->isBlockPointerType()) && + RHS.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { + // promote the null to a pointer. + RHS = ImpCastExprToType(RHS.take(), LHSTy, CK_NullToPointer); + return LHSTy; + } + if ((RHSTy->isAnyPointerType() || RHSTy->isBlockPointerType()) && + LHS.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNull)) { + LHS = ImpCastExprToType(LHS.take(), RHSTy, CK_NullToPointer); + return RHSTy; + } + + // All objective-c pointer type analysis is done here. + QualType compositeType = FindCompositeObjCPointerType(LHS, RHS, + QuestionLoc); + if (LHS.isInvalid() || RHS.isInvalid()) + return QualType(); + if (!compositeType.isNull()) + return compositeType; + + + // Handle block pointer types. + if (LHSTy->isBlockPointerType() || RHSTy->isBlockPointerType()) { + if (!LHSTy->isBlockPointerType() || !RHSTy->isBlockPointerType()) { + if (LHSTy->isVoidPointerType() || RHSTy->isVoidPointerType()) { + QualType destType = Context.getPointerType(Context.VoidTy); + LHS = ImpCastExprToType(LHS.take(), destType, CK_BitCast); + RHS = ImpCastExprToType(RHS.take(), destType, CK_BitCast); + return destType; + } + Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) + << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + return QualType(); + } + // We have 2 block pointer types. + if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { + // Two identical block pointer types are always compatible. + return LHSTy; + } + // The block pointer types aren't identical, continue checking. + QualType lhptee = LHSTy->getAs<BlockPointerType>()->getPointeeType(); + QualType rhptee = RHSTy->getAs<BlockPointerType>()->getPointeeType(); + + if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), + rhptee.getUnqualifiedType())) { + Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) + << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + // In this situation, we assume void* type. No especially good + // reason, but this is what gcc does, and we do have to pick + // to get a consistent AST. + QualType incompatTy = Context.getPointerType(Context.VoidTy); + LHS = ImpCastExprToType(LHS.take(), incompatTy, CK_BitCast); + RHS = ImpCastExprToType(RHS.take(), incompatTy, CK_BitCast); + return incompatTy; + } + // The block pointer types are compatible. + LHS = ImpCastExprToType(LHS.take(), LHSTy, CK_BitCast); + RHS = ImpCastExprToType(RHS.take(), LHSTy, CK_BitCast); + return LHSTy; + } + + // Check constraints for C object pointers types (C99 6.5.15p3,6). + if (LHSTy->isPointerType() && RHSTy->isPointerType()) { + // get the "pointed to" types + QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); + QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); + + // ignore qualifiers on void (C99 6.5.15p3, clause 6) + if (lhptee->isVoidType() && rhptee->isIncompleteOrObjectType()) { + // Figure out necessary qualifiers (C99 6.5.15p6) + QualType destPointee + = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); + QualType destType = Context.getPointerType(destPointee); + // Add qualifiers if necessary. + LHS = ImpCastExprToType(LHS.take(), destType, CK_NoOp); + // Promote to void*. + RHS = ImpCastExprToType(RHS.take(), destType, CK_BitCast); + return destType; + } + if (rhptee->isVoidType() && lhptee->isIncompleteOrObjectType()) { + QualType destPointee + = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); + QualType destType = Context.getPointerType(destPointee); + // Add qualifiers if necessary. + RHS = ImpCastExprToType(RHS.take(), destType, CK_NoOp); + // Promote to void*. + LHS = ImpCastExprToType(LHS.take(), destType, CK_BitCast); + return destType; + } + + if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { + // Two identical pointer types are always compatible. + return LHSTy; + } + if (!Context.typesAreCompatible(lhptee.getUnqualifiedType(), + rhptee.getUnqualifiedType())) { + Diag(QuestionLoc, diag::warn_typecheck_cond_incompatible_pointers) + << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + // In this situation, we assume void* type. No especially good + // reason, but this is what gcc does, and we do have to pick + // to get a consistent AST. + QualType incompatTy = Context.getPointerType(Context.VoidTy); + LHS = ImpCastExprToType(LHS.take(), incompatTy, CK_BitCast); + RHS = ImpCastExprToType(RHS.take(), incompatTy, CK_BitCast); + return incompatTy; + } + // The pointer types are compatible. + // C99 6.5.15p6: If both operands are pointers to compatible types *or* to + // differently qualified versions of compatible types, the result type is + // a pointer to an appropriately qualified version of the *composite* + // type. + // FIXME: Need to calculate the composite type. + // FIXME: Need to add qualifiers + LHS = ImpCastExprToType(LHS.take(), LHSTy, CK_BitCast); + RHS = ImpCastExprToType(RHS.take(), LHSTy, CK_BitCast); + return LHSTy; + } + + // GCC compatibility: soften pointer/integer mismatch. Note that + // null pointers have been filtered out by this point. + if (RHSTy->isPointerType() && LHSTy->isIntegerType()) { + Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) + << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + LHS = ImpCastExprToType(LHS.take(), RHSTy, CK_IntegralToPointer); + return RHSTy; + } + if (LHSTy->isPointerType() && RHSTy->isIntegerType()) { + Diag(QuestionLoc, diag::warn_typecheck_cond_pointer_integer_mismatch) + << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + RHS = ImpCastExprToType(RHS.take(), LHSTy, CK_IntegralToPointer); + return LHSTy; + } + + // Emit a better diagnostic if one of the expressions is a null pointer + // constant and the other is not a pointer type. In this case, the user most + // likely forgot to take the address of the other expression. + if (DiagnoseConditionalForNull(LHS.get(), RHS.get(), QuestionLoc)) + return QualType(); + + // Otherwise, the operands are not compatible. + Diag(QuestionLoc, diag::err_typecheck_cond_incompatible_operands) + << LHSTy << RHSTy << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + return QualType(); +} + +/// FindCompositeObjCPointerType - Helper method to find composite type of +/// two objective-c pointer types of the two input expressions. +QualType Sema::FindCompositeObjCPointerType(ExprResult &LHS, ExprResult &RHS, + SourceLocation QuestionLoc) { + QualType LHSTy = LHS.get()->getType(); + QualType RHSTy = RHS.get()->getType(); + + // Handle things like Class and struct objc_class*. Here we case the result + // to the pseudo-builtin, because that will be implicitly cast back to the + // redefinition type if an attempt is made to access its fields. + if (LHSTy->isObjCClassType() && + (Context.hasSameType(RHSTy, Context.ObjCClassRedefinitionType))) { + RHS = ImpCastExprToType(RHS.take(), LHSTy, CK_BitCast); + return LHSTy; + } + if (RHSTy->isObjCClassType() && + (Context.hasSameType(LHSTy, Context.ObjCClassRedefinitionType))) { + LHS = ImpCastExprToType(LHS.take(), RHSTy, CK_BitCast); + return RHSTy; + } + // And the same for struct objc_object* / id + if (LHSTy->isObjCIdType() && + (Context.hasSameType(RHSTy, Context.ObjCIdRedefinitionType))) { + RHS = ImpCastExprToType(RHS.take(), LHSTy, CK_BitCast); + return LHSTy; + } + if (RHSTy->isObjCIdType() && + (Context.hasSameType(LHSTy, Context.ObjCIdRedefinitionType))) { + LHS = ImpCastExprToType(LHS.take(), RHSTy, CK_BitCast); + return RHSTy; + } + // And the same for struct objc_selector* / SEL + if (Context.isObjCSelType(LHSTy) && + (Context.hasSameType(RHSTy, Context.ObjCSelRedefinitionType))) { + RHS = ImpCastExprToType(RHS.take(), LHSTy, CK_BitCast); + return LHSTy; + } + if (Context.isObjCSelType(RHSTy) && + (Context.hasSameType(LHSTy, Context.ObjCSelRedefinitionType))) { + LHS = ImpCastExprToType(LHS.take(), RHSTy, CK_BitCast); + return RHSTy; + } + // Check constraints for Objective-C object pointers types. + if (LHSTy->isObjCObjectPointerType() && RHSTy->isObjCObjectPointerType()) { + + if (Context.getCanonicalType(LHSTy) == Context.getCanonicalType(RHSTy)) { + // Two identical object pointer types are always compatible. + return LHSTy; + } + const ObjCObjectPointerType *LHSOPT = LHSTy->getAs<ObjCObjectPointerType>(); + const ObjCObjectPointerType *RHSOPT = RHSTy->getAs<ObjCObjectPointerType>(); + QualType compositeType = LHSTy; + + // If both operands are interfaces and either operand can be + // assigned to the other, use that type as the composite + // type. This allows + // xxx ? (A*) a : (B*) b + // where B is a subclass of A. + // + // Additionally, as for assignment, if either type is 'id' + // allow silent coercion. Finally, if the types are + // incompatible then make sure to use 'id' as the composite + // type so the result is acceptable for sending messages to. + + // FIXME: Consider unifying with 'areComparableObjCPointerTypes'. + // It could return the composite type. + if (Context.canAssignObjCInterfaces(LHSOPT, RHSOPT)) { + compositeType = RHSOPT->isObjCBuiltinType() ? RHSTy : LHSTy; + } else if (Context.canAssignObjCInterfaces(RHSOPT, LHSOPT)) { + compositeType = LHSOPT->isObjCBuiltinType() ? LHSTy : RHSTy; + } else if ((LHSTy->isObjCQualifiedIdType() || + RHSTy->isObjCQualifiedIdType()) && + Context.ObjCQualifiedIdTypesAreCompatible(LHSTy, RHSTy, true)) { + // Need to handle "id<xx>" explicitly. + // GCC allows qualified id and any Objective-C type to devolve to + // id. Currently localizing to here until clear this should be + // part of ObjCQualifiedIdTypesAreCompatible. + compositeType = Context.getObjCIdType(); + } else if (LHSTy->isObjCIdType() || RHSTy->isObjCIdType()) { + compositeType = Context.getObjCIdType(); + } else if (!(compositeType = + Context.areCommonBaseCompatible(LHSOPT, RHSOPT)).isNull()) + ; + else { + Diag(QuestionLoc, diag::ext_typecheck_cond_incompatible_operands) + << LHSTy << RHSTy + << LHS.get()->getSourceRange() << RHS.get()->getSourceRange(); + QualType incompatTy = Context.getObjCIdType(); + LHS = ImpCastExprToType(LHS.take(), incompatTy, CK_BitCast); + RHS = ImpCastExprToType(RHS.take(), incompatTy, CK_BitCast); + return incompatTy; + } + // The object pointer types are compatible. + LHS = ImpCastExprToType(LHS.take(), compositeType, CK_BitCast); + RHS = ImpCastExprToType(RHS.take(), compositeType, CK_BitCast); + return compositeType; + } + // Check Objective-C object pointer types and 'void *' + if (LHSTy->isVoidPointerType() && RHSTy->isObjCObjectPointerType()) { + QualType lhptee = LHSTy->getAs<PointerType>()->getPointeeType(); + QualType rhptee = RHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); + QualType destPointee + = Context.getQualifiedType(lhptee, rhptee.getQualifiers()); + QualType destType = Context.getPointerType(destPointee); + // Add qualifiers if necessary. + LHS = ImpCastExprToType(LHS.take(), destType, CK_NoOp); + // Promote to void*. + RHS = ImpCastExprToType(RHS.take(), destType, CK_BitCast); + return destType; + } + if (LHSTy->isObjCObjectPointerType() && RHSTy->isVoidPointerType()) { + QualType lhptee = LHSTy->getAs<ObjCObjectPointerType>()->getPointeeType(); + QualType rhptee = RHSTy->getAs<PointerType>()->getPointeeType(); + QualType destPointee + = Context.getQualifiedType(rhptee, lhptee.getQualifiers()); + QualType destType = Context.getPointerType(destPointee); + // Add qualifiers if necessary. + RHS = ImpCastExprToType(RHS.take(), destType, CK_NoOp); + // Promote to void*. + LHS = ImpCastExprToType(LHS.take(), destType, CK_BitCast); + return destType; + } + return QualType(); +} + +/// ActOnConditionalOp - Parse a ?: operation. Note that 'LHS' may be null +/// in the case of a the GNU conditional expr extension. +ExprResult Sema::ActOnConditionalOp(SourceLocation QuestionLoc, + SourceLocation ColonLoc, + Expr *CondExpr, Expr *LHSExpr, + Expr *RHSExpr) { + // If this is the gnu "x ?: y" extension, analyze the types as though the LHS + // was the condition. + OpaqueValueExpr *opaqueValue = 0; + Expr *commonExpr = 0; + if (LHSExpr == 0) { + commonExpr = CondExpr; + + // We usually want to apply unary conversions *before* saving, except + // in the special case of a C++ l-value conditional. + if (!(getLangOptions().CPlusPlus + && !commonExpr->isTypeDependent() + && commonExpr->getValueKind() == RHSExpr->getValueKind() + && commonExpr->isGLValue() + && commonExpr->isOrdinaryOrBitFieldObject() + && RHSExpr->isOrdinaryOrBitFieldObject() + && Context.hasSameType(commonExpr->getType(), RHSExpr->getType()))) { + ExprResult commonRes = UsualUnaryConversions(commonExpr); + if (commonRes.isInvalid()) + return ExprError(); + commonExpr = commonRes.take(); + } + + opaqueValue = new (Context) OpaqueValueExpr(commonExpr->getExprLoc(), + commonExpr->getType(), + commonExpr->getValueKind(), + commonExpr->getObjectKind()); + LHSExpr = CondExpr = opaqueValue; + } + + ExprValueKind VK = VK_RValue; + ExprObjectKind OK = OK_Ordinary; + ExprResult Cond = Owned(CondExpr), LHS = Owned(LHSExpr), RHS = Owned(RHSExpr); + QualType result = CheckConditionalOperands(Cond, LHS, RHS, + VK, OK, QuestionLoc); + if (result.isNull() || Cond.isInvalid() || LHS.isInvalid() || + RHS.isInvalid()) + return ExprError(); + + if (!commonExpr) + return Owned(new (Context) ConditionalOperator(Cond.take(), QuestionLoc, + LHS.take(), ColonLoc, + RHS.take(), result, VK, OK)); + + return Owned(new (Context) + BinaryConditionalOperator(commonExpr, opaqueValue, Cond.take(), LHS.take(), + RHS.take(), QuestionLoc, ColonLoc, result, VK, OK)); +} + +// checkPointerTypesForAssignment - This is a very tricky routine (despite +// being closely modeled after the C99 spec:-). The odd characteristic of this +// routine is it effectively iqnores the qualifiers on the top level pointee. +// This circumvents the usual type rules specified in 6.2.7p1 & 6.7.5.[1-3]. +// FIXME: add a couple examples in this comment. +static Sema::AssignConvertType +checkPointerTypesForAssignment(Sema &S, QualType lhsType, QualType rhsType) { + assert(lhsType.isCanonical() && "LHS not canonicalized!"); + assert(rhsType.isCanonical() && "RHS not canonicalized!"); + + // get the "pointed to" type (ignoring qualifiers at the top level) + const Type *lhptee, *rhptee; + Qualifiers lhq, rhq; + llvm::tie(lhptee, lhq) = cast<PointerType>(lhsType)->getPointeeType().split(); + llvm::tie(rhptee, rhq) = cast<PointerType>(rhsType)->getPointeeType().split(); + + Sema::AssignConvertType ConvTy = Sema::Compatible; + + // C99 6.5.16.1p1: This following citation is common to constraints + // 3 & 4 (below). ...and the type *pointed to* by the left has all the + // qualifiers of the type *pointed to* by the right; + Qualifiers lq; + + if (!lhq.compatiblyIncludes(rhq)) { + // Treat address-space mismatches as fatal. TODO: address subspaces + if (lhq.getAddressSpace() != rhq.getAddressSpace()) + ConvTy = Sema::IncompatiblePointerDiscardsQualifiers; + + // It's okay to add or remove GC qualifiers when converting to + // and from void*. + else if (lhq.withoutObjCGCAttr().compatiblyIncludes(rhq.withoutObjCGCAttr()) + && (lhptee->isVoidType() || rhptee->isVoidType())) + ; // keep old + + // For GCC compatibility, other qualifier mismatches are treated + // as still compatible in C. + else ConvTy = Sema::CompatiblePointerDiscardsQualifiers; + } + + // C99 6.5.16.1p1 (constraint 4): If one operand is a pointer to an object or + // incomplete type and the other is a pointer to a qualified or unqualified + // version of void... + if (lhptee->isVoidType()) { + if (rhptee->isIncompleteOrObjectType()) + return ConvTy; + + // As an extension, we allow cast to/from void* to function pointer. + assert(rhptee->isFunctionType()); + return Sema::FunctionVoidPointer; + } + + if (rhptee->isVoidType()) { + if (lhptee->isIncompleteOrObjectType()) + return ConvTy; + + // As an extension, we allow cast to/from void* to function pointer. + assert(lhptee->isFunctionType()); + return Sema::FunctionVoidPointer; + } + + // C99 6.5.16.1p1 (constraint 3): both operands are pointers to qualified or + // unqualified versions of compatible types, ... + QualType ltrans = QualType(lhptee, 0), rtrans = QualType(rhptee, 0); + if (!S.Context.typesAreCompatible(ltrans, rtrans)) { + // Check if the pointee types are compatible ignoring the sign. + // We explicitly check for char so that we catch "char" vs + // "unsigned char" on systems where "char" is unsigned. + if (lhptee->isCharType()) + ltrans = S.Context.UnsignedCharTy; + else if (lhptee->hasSignedIntegerRepresentation()) + ltrans = S.Context.getCorrespondingUnsignedType(ltrans); + + if (rhptee->isCharType()) + rtrans = S.Context.UnsignedCharTy; + else if (rhptee->hasSignedIntegerRepresentation()) + rtrans = S.Context.getCorrespondingUnsignedType(rtrans); + + if (ltrans == rtrans) { + // Types are compatible ignoring the sign. Qualifier incompatibility + // takes priority over sign incompatibility because the sign + // warning can be disabled. + if (ConvTy != Sema::Compatible) + return ConvTy; + + return Sema::IncompatiblePointerSign; + } + + // If we are a multi-level pointer, it's possible that our issue is simply + // one of qualification - e.g. char ** -> const char ** is not allowed. If + // the eventual target type is the same and the pointers have the same + // level of indirection, this must be the issue. + if (isa<PointerType>(lhptee) && isa<PointerType>(rhptee)) { + do { + lhptee = cast<PointerType>(lhptee)->getPointeeType().getTypePtr(); + rhptee = cast<PointerType>(rhptee)->getPointeeType().getTypePtr(); + } while (isa<PointerType>(lhptee) && isa<PointerType>(rhptee)); + + if (lhptee == rhptee) + return Sema::IncompatibleNestedPointerQualifiers; + } + + // General pointer incompatibility takes priority over qualifiers. + return Sema::IncompatiblePointer; + } + return ConvTy; +} + +/// checkBlockPointerTypesForAssignment - This routine determines whether two +/// block pointer types are compatible or whether a block and normal pointer +/// are compatible. It is more restrict than comparing two function pointer +// types. +static Sema::AssignConvertType +checkBlockPointerTypesForAssignment(Sema &S, QualType lhsType, + QualType rhsType) { + assert(lhsType.isCanonical() && "LHS not canonicalized!"); + assert(rhsType.isCanonical() && "RHS not canonicalized!"); + + QualType lhptee, rhptee; + + // get the "pointed to" type (ignoring qualifiers at the top level) + lhptee = cast<BlockPointerType>(lhsType)->getPointeeType(); + rhptee = cast<BlockPointerType>(rhsType)->getPointeeType(); + + // In C++, the types have to match exactly. + if (S.getLangOptions().CPlusPlus) + return Sema::IncompatibleBlockPointer; + + Sema::AssignConvertType ConvTy = Sema::Compatible; + + // For blocks we enforce that qualifiers are identical. + if (lhptee.getLocalQualifiers() != rhptee.getLocalQualifiers()) + ConvTy = Sema::CompatiblePointerDiscardsQualifiers; + + if (!S.Context.typesAreBlockPointerCompatible(lhsType, rhsType)) + return Sema::IncompatibleBlockPointer; + + return ConvTy; +} + +/// checkObjCPointerTypesForAssignment - Compares two objective-c pointer types +/// for assignment compatibility. +static Sema::AssignConvertType +checkObjCPointerTypesForAssignment(Sema &S, QualType lhsType, QualType rhsType) { + assert(lhsType.isCanonical() && "LHS was not canonicalized!"); + assert(rhsType.isCanonical() && "RHS was not canonicalized!"); + + if (lhsType->isObjCBuiltinType()) { + // Class is not compatible with ObjC object pointers. + if (lhsType->isObjCClassType() && !rhsType->isObjCBuiltinType() && + !rhsType->isObjCQualifiedClassType()) + return Sema::IncompatiblePointer; + return Sema::Compatible; + } + if (rhsType->isObjCBuiltinType()) { + // Class is not compatible with ObjC object pointers. + if (rhsType->isObjCClassType() && !lhsType->isObjCBuiltinType() && + !lhsType->isObjCQualifiedClassType()) + return Sema::IncompatiblePointer; + return Sema::Compatible; + } + QualType lhptee = + lhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); + QualType rhptee = + rhsType->getAs<ObjCObjectPointerType>()->getPointeeType(); + + if (!lhptee.isAtLeastAsQualifiedAs(rhptee)) + return Sema::CompatiblePointerDiscardsQualifiers; + + if (S.Context.typesAreCompatible(lhsType, rhsType)) + return Sema::Compatible; + if (lhsType->isObjCQualifiedIdType() || rhsType->isObjCQualifiedIdType()) + return Sema::IncompatibleObjCQualifiedId; + return Sema::IncompatiblePointer; +} + +Sema::AssignConvertType +Sema::CheckAssignmentConstraints(SourceLocation Loc, + QualType lhsType, QualType rhsType) { + // Fake up an opaque expression. We don't actually care about what + // cast operations are required, so if CheckAssignmentConstraints + // adds casts to this they'll be wasted, but fortunately that doesn't + // usually happen on valid code. + OpaqueValueExpr rhs(Loc, rhsType, VK_RValue); + ExprResult rhsPtr = &rhs; + CastKind K = CK_Invalid; + + return CheckAssignmentConstraints(lhsType, rhsPtr, K); +} + +/// CheckAssignmentConstraints (C99 6.5.16) - This routine currently +/// has code to accommodate several GCC extensions when type checking +/// pointers. Here are some objectionable examples that GCC considers warnings: +/// +/// int a, *pint; +/// short *pshort; +/// struct foo *pfoo; +/// +/// pint = pshort; // warning: assignment from incompatible pointer type +/// a = pint; // warning: assignment makes integer from pointer without a cast +/// pint = a; // warning: assignment makes pointer from integer without a cast +/// pint = pfoo; // warning: assignment from incompatible pointer type +/// +/// As a result, the code for dealing with pointers is more complex than the +/// C99 spec dictates. +/// +/// Sets 'Kind' for any result kind except Incompatible. +Sema::AssignConvertType +Sema::CheckAssignmentConstraints(QualType lhsType, ExprResult &rhs, + CastKind &Kind) { + QualType rhsType = rhs.get()->getType(); + + // Get canonical types. We're not formatting these types, just comparing + // them. + lhsType = Context.getCanonicalType(lhsType).getUnqualifiedType(); + rhsType = Context.getCanonicalType(rhsType).getUnqualifiedType(); + + // Common case: no conversion required. + if (lhsType == rhsType) { + Kind = CK_NoOp; + return Compatible; + } + + // If the left-hand side is a reference type, then we are in a + // (rare!) case where we've allowed the use of references in C, + // e.g., as a parameter type in a built-in function. In this case, + // just make sure that the type referenced is compatible with the + // right-hand side type. The caller is responsible for adjusting + // lhsType so that the resulting expression does not have reference + // type. + if (const ReferenceType *lhsTypeRef = lhsType->getAs<ReferenceType>()) { + if (Context.typesAreCompatible(lhsTypeRef->getPointeeType(), rhsType)) { + Kind = CK_LValueBitCast; + return Compatible; + } + return Incompatible; + } + + // Allow scalar to ExtVector assignments, and assignments of an ExtVector type + // to the same ExtVector type. + if (lhsType->isExtVectorType()) { + if (rhsType->isExtVectorType()) + return Incompatible; + if (rhsType->isArithmeticType()) { + // CK_VectorSplat does T -> vector T, so first cast to the + // element type. + QualType elType = cast<ExtVectorType>(lhsType)->getElementType(); + if (elType != rhsType) { + Kind = PrepareScalarCast(*this, rhs, elType); + rhs = ImpCastExprToType(rhs.take(), elType, Kind); + } + Kind = CK_VectorSplat; + return Compatible; + } + } + + // Conversions to or from vector type. + if (lhsType->isVectorType() || rhsType->isVectorType()) { + if (lhsType->isVectorType() && rhsType->isVectorType()) { + // Allow assignments of an AltiVec vector type to an equivalent GCC + // vector type and vice versa + if (Context.areCompatibleVectorTypes(lhsType, rhsType)) { + Kind = CK_BitCast; + return Compatible; + } + + // If we are allowing lax vector conversions, and LHS and RHS are both + // vectors, the total size only needs to be the same. This is a bitcast; + // no bits are changed but the result type is different. + if (getLangOptions().LaxVectorConversions && + (Context.getTypeSize(lhsType) == Context.getTypeSize(rhsType))) { + Kind = CK_BitCast; + return IncompatibleVectors; + } + } + return Incompatible; + } + + // Arithmetic conversions. + if (lhsType->isArithmeticType() && rhsType->isArithmeticType() && + !(getLangOptions().CPlusPlus && lhsType->isEnumeralType())) { + Kind = PrepareScalarCast(*this, rhs, lhsType); + return Compatible; + } + + // Conversions to normal pointers. + if (const PointerType *lhsPointer = dyn_cast<PointerType>(lhsType)) { + // U* -> T* + if (isa<PointerType>(rhsType)) { + Kind = CK_BitCast; + return checkPointerTypesForAssignment(*this, lhsType, rhsType); + } + + // int -> T* + if (rhsType->isIntegerType()) { + Kind = CK_IntegralToPointer; // FIXME: null? + return IntToPointer; + } + + // C pointers are not compatible with ObjC object pointers, + // with two exceptions: + if (isa<ObjCObjectPointerType>(rhsType)) { + // - conversions to void* + if (lhsPointer->getPointeeType()->isVoidType()) { + Kind = CK_AnyPointerToObjCPointerCast; + return Compatible; + } + + // - conversions from 'Class' to the redefinition type + if (rhsType->isObjCClassType() && + Context.hasSameType(lhsType, Context.ObjCClassRedefinitionType)) { + Kind = CK_BitCast; + return Compatible; + } + + Kind = CK_BitCast; + return IncompatiblePointer; + } + + // U^ -> void* + if (rhsType->getAs<BlockPointerType>()) { + if (lhsPointer->getPointeeType()->isVoidType()) { + Kind = CK_BitCast; + return Compatible; + } + } + + return Incompatible; + } + + // Conversions to block pointers. + if (isa<BlockPointerType>(lhsType)) { + // U^ -> T^ + if (rhsType->isBlockPointerType()) { + Kind = CK_AnyPointerToBlockPointerCast; + return checkBlockPointerTypesForAssignment(*this, lhsType, rhsType); + } + + // int or null -> T^ + if (rhsType->isIntegerType()) { + Kind = CK_IntegralToPointer; // FIXME: null + return IntToBlockPointer; + } + + // id -> T^ + if (getLangOptions().ObjC1 && rhsType->isObjCIdType()) { + Kind = CK_AnyPointerToBlockPointerCast; + return Compatible; + } + + // void* -> T^ + if (const PointerType *RHSPT = rhsType->getAs<PointerType>()) + if (RHSPT->getPointeeType()->isVoidType()) { + Kind = CK_AnyPointerToBlockPointerCast; + return Compatible; + } + + return Incompatible; + } + + // Conversions to Objective-C pointers. + if (isa<ObjCObjectPointerType>(lhsType)) { + // A* -> B* + if (rhsType->isObjCObjectPointerType()) { + Kind = CK_BitCast; + return checkObjCPointerTypesForAssignment(*this, lhsType, rhsType); + } + + // int or null -> A* + if (rhsType->isIntegerType()) { + Kind = CK_IntegralToPointer; // FIXME: null + return IntToPointer; + } + + // In general, C pointers are not compatible with ObjC object pointers, + // with two exceptions: + if (isa<PointerType>(rhsType)) { + // - conversions from 'void*' + if (rhsType->isVoidPointerType()) { + Kind = CK_AnyPointerToObjCPointerCast; + return Compatible; + } + + // - conversions to 'Class' from its redefinition type + if (lhsType->isObjCClassType() && + Context.hasSameType(rhsType, Context.ObjCClassRedefinitionType)) { + Kind = CK_BitCast; + return Compatible; + } + + Kind = CK_AnyPointerToObjCPointerCast; + return IncompatiblePointer; + } + + // T^ -> A* + if (rhsType->isBlockPointerType()) { + Kind = CK_AnyPointerToObjCPointerCast; + return Compatible; + } + + return Incompatible; + } + + // Conversions from pointers that are not covered by the above. + if (isa<PointerType>(rhsType)) { + // T* -> _Bool + if (lhsType == Context.BoolTy) { + Kind = CK_PointerToBoolean; + return Compatible; + } + + // T* -> int + if (lhsType->isIntegerType()) { + Kind = CK_PointerToIntegral; + return PointerToInt; + } + + return Incompatible; + } + + // Conversions from Objective-C pointers that are not covered by the above. + if (isa<ObjCObjectPointerType>(rhsType)) { + // T* -> _Bool + if (lhsType == Context.BoolTy) { + Kind = CK_PointerToBoolean; + return Compatible; + } + + // T* -> int + if (lhsType->isIntegerType()) { + Kind = CK_PointerToIntegral; + return PointerToInt; + } + + return Incompatible; + } + + // struct A -> struct B + if (isa<TagType>(lhsType) && isa<TagType>(rhsType)) { + if (Context.typesAreCompatible(lhsType, rhsType)) { + Kind = CK_NoOp; + return Compatible; + } + } + + return Incompatible; +} + +/// \brief Constructs a transparent union from an expression that is +/// used to initialize the transparent union. +static void ConstructTransparentUnion(Sema &S, ASTContext &C, ExprResult &EResult, + QualType UnionType, FieldDecl *Field) { + // Build an initializer list that designates the appropriate member + // of the transparent union. + Expr *E = EResult.take(); + InitListExpr *Initializer = new (C) InitListExpr(C, SourceLocation(), + &E, 1, + SourceLocation()); + Initializer->setType(UnionType); + Initializer->setInitializedFieldInUnion(Field); + + // Build a compound literal constructing a value of the transparent + // union type from this initializer list. + TypeSourceInfo *unionTInfo = C.getTrivialTypeSourceInfo(UnionType); + EResult = S.Owned( + new (C) CompoundLiteralExpr(SourceLocation(), unionTInfo, UnionType, + VK_RValue, Initializer, false)); +} + +Sema::AssignConvertType +Sema::CheckTransparentUnionArgumentConstraints(QualType ArgType, ExprResult &rExpr) { + QualType FromType = rExpr.get()->getType(); + + // If the ArgType is a Union type, we want to handle a potential + // transparent_union GCC extension. + const RecordType *UT = ArgType->getAsUnionType(); + if (!UT || !UT->getDecl()->hasAttr<TransparentUnionAttr>()) + return Incompatible; + + // The field to initialize within the transparent union. + RecordDecl *UD = UT->getDecl(); + FieldDecl *InitField = 0; + // It's compatible if the expression matches any of the fields. + for (RecordDecl::field_iterator it = UD->field_begin(), + itend = UD->field_end(); + it != itend; ++it) { + if (it->getType()->isPointerType()) { + // If the transparent union contains a pointer type, we allow: + // 1) void pointer + // 2) null pointer constant + if (FromType->isPointerType()) + if (FromType->getAs<PointerType>()->getPointeeType()->isVoidType()) { + rExpr = ImpCastExprToType(rExpr.take(), it->getType(), CK_BitCast); + InitField = *it; + break; + } + + if (rExpr.get()->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNull)) { + rExpr = ImpCastExprToType(rExpr.take(), it->getType(), CK_NullToPointer); + InitField = *it; + break; + } + } + + CastKind Kind = CK_Invalid; + if (CheckAssignmentConstraints(it->getType(), rExpr, Kind) + == Compatible) { + rExpr = ImpCastExprToType(rExpr.take(), it->getType(), Kind); + InitField = *it; + break; + } + } + + if (!InitField) + return Incompatible; + + ConstructTransparentUnion(*this, Context, rExpr, ArgType, InitField); + return Compatible; +} + +Sema::AssignConvertType +Sema::CheckSingleAssignmentConstraints(QualType lhsType, ExprResult &rExpr) { + if (getLangOptions().CPlusPlus) { + if (!lhsType->isRecordType()) { + // C++ 5.17p3: If the left operand is not of class type, the + // expression is implicitly converted (C++ 4) to the + // cv-unqualified type of the left operand. + ExprResult Res = PerformImplicitConversion(rExpr.get(), + lhsType.getUnqualifiedType(), + AA_Assigning); + if (Res.isInvalid()) + return Incompatible; + rExpr = move(Res); + return Compatible; + } + + // FIXME: Currently, we fall through and treat C++ classes like C + // structures. + } + + // C99 6.5.16.1p1: the left operand is a pointer and the right is + // a null pointer constant. + if ((lhsType->isPointerType() || + lhsType->isObjCObjectPointerType() || + lhsType->isBlockPointerType()) + && rExpr.get()->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNull)) { + rExpr = ImpCastExprToType(rExpr.take(), lhsType, CK_NullToPointer); + return Compatible; + } + + // This check seems unnatural, however it is necessary to ensure the proper + // conversion of functions/arrays. If the conversion were done for all + // DeclExpr's (created by ActOnIdExpression), it would mess up the unary + // expressions that suppress this implicit conversion (&, sizeof). + // + // Suppress this for references: C++ 8.5.3p5. + if (!lhsType->isReferenceType()) { + rExpr = DefaultFunctionArrayLvalueConversion(rExpr.take()); + if (rExpr.isInvalid()) + return Incompatible; + } + + CastKind Kind = CK_Invalid; + Sema::AssignConvertType result = + CheckAssignmentConstraints(lhsType, rExpr, Kind); + + // C99 6.5.16.1p2: The value of the right operand is converted to the + // type of the assignment expression. + // CheckAssignmentConstraints allows the left-hand side to be a reference, + // so that we can use references in built-in functions even in C. + // The getNonReferenceType() call makes sure that the resulting expression + // does not have reference type. + if (result != Incompatible && rExpr.get()->getType() != lhsType) + rExpr = ImpCastExprToType(rExpr.take(), lhsType.getNonLValueExprType(Context), Kind); + return result; +} + +QualType Sema::InvalidOperands(SourceLocation Loc, ExprResult &lex, ExprResult &rex) { + Diag(Loc, diag::err_typecheck_invalid_operands) + << lex.get()->getType() << rex.get()->getType() + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); +} + +QualType Sema::CheckVectorOperands(SourceLocation Loc, ExprResult &lex, ExprResult &rex) { + // For conversion purposes, we ignore any qualifiers. + // For example, "const float" and "float" are equivalent. + QualType lhsType = + Context.getCanonicalType(lex.get()->getType()).getUnqualifiedType(); + QualType rhsType = + Context.getCanonicalType(rex.get()->getType()).getUnqualifiedType(); + + // If the vector types are identical, return. + if (lhsType == rhsType) + return lhsType; + + // Handle the case of a vector & extvector type of the same size and element + // type. It would be nice if we only had one vector type someday. + if (getLangOptions().LaxVectorConversions) { + if (const VectorType *LV = lhsType->getAs<VectorType>()) { + if (const VectorType *RV = rhsType->getAs<VectorType>()) { + if (LV->getElementType() == RV->getElementType() && + LV->getNumElements() == RV->getNumElements()) { + if (lhsType->isExtVectorType()) { + rex = ImpCastExprToType(rex.take(), lhsType, CK_BitCast); + return lhsType; + } + + lex = ImpCastExprToType(lex.take(), rhsType, CK_BitCast); + return rhsType; + } else if (Context.getTypeSize(lhsType) ==Context.getTypeSize(rhsType)){ + // If we are allowing lax vector conversions, and LHS and RHS are both + // vectors, the total size only needs to be the same. This is a + // bitcast; no bits are changed but the result type is different. + rex = ImpCastExprToType(rex.take(), lhsType, CK_BitCast); + return lhsType; + } + } + } + } + + // Handle the case of equivalent AltiVec and GCC vector types + if (lhsType->isVectorType() && rhsType->isVectorType() && + Context.areCompatibleVectorTypes(lhsType, rhsType)) { + lex = ImpCastExprToType(lex.take(), rhsType, CK_BitCast); + return rhsType; + } + + // Canonicalize the ExtVector to the LHS, remember if we swapped so we can + // swap back (so that we don't reverse the inputs to a subtract, for instance. + bool swapped = false; + if (rhsType->isExtVectorType()) { + swapped = true; + std::swap(rex, lex); + std::swap(rhsType, lhsType); + } + + // Handle the case of an ext vector and scalar. + if (const ExtVectorType *LV = lhsType->getAs<ExtVectorType>()) { + QualType EltTy = LV->getElementType(); + if (EltTy->isIntegralType(Context) && rhsType->isIntegralType(Context)) { + int order = Context.getIntegerTypeOrder(EltTy, rhsType); + if (order > 0) + rex = ImpCastExprToType(rex.take(), EltTy, CK_IntegralCast); + if (order >= 0) { + rex = ImpCastExprToType(rex.take(), lhsType, CK_VectorSplat); + if (swapped) std::swap(rex, lex); + return lhsType; + } + } + if (EltTy->isRealFloatingType() && rhsType->isScalarType() && + rhsType->isRealFloatingType()) { + int order = Context.getFloatingTypeOrder(EltTy, rhsType); + if (order > 0) + rex = ImpCastExprToType(rex.take(), EltTy, CK_FloatingCast); + if (order >= 0) { + rex = ImpCastExprToType(rex.take(), lhsType, CK_VectorSplat); + if (swapped) std::swap(rex, lex); + return lhsType; + } + } + } + + // Vectors of different size or scalar and non-ext-vector are errors. + Diag(Loc, diag::err_typecheck_vector_not_convertable) + << lex.get()->getType() << rex.get()->getType() + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); +} + +QualType Sema::CheckMultiplyDivideOperands( + ExprResult &lex, ExprResult &rex, SourceLocation Loc, bool isCompAssign, bool isDiv) { + if (lex.get()->getType()->isVectorType() || rex.get()->getType()->isVectorType()) + return CheckVectorOperands(Loc, lex, rex); + + QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); + if (lex.isInvalid() || rex.isInvalid()) + return QualType(); + + if (!lex.get()->getType()->isArithmeticType() || + !rex.get()->getType()->isArithmeticType()) + return InvalidOperands(Loc, lex, rex); + + // Check for division by zero. + if (isDiv && + rex.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) + DiagRuntimeBehavior(Loc, rex.get(), PDiag(diag::warn_division_by_zero) + << rex.get()->getSourceRange()); + + return compType; +} + +QualType Sema::CheckRemainderOperands( + ExprResult &lex, ExprResult &rex, SourceLocation Loc, bool isCompAssign) { + if (lex.get()->getType()->isVectorType() || rex.get()->getType()->isVectorType()) { + if (lex.get()->getType()->hasIntegerRepresentation() && + rex.get()->getType()->hasIntegerRepresentation()) + return CheckVectorOperands(Loc, lex, rex); + return InvalidOperands(Loc, lex, rex); + } + + QualType compType = UsualArithmeticConversions(lex, rex, isCompAssign); + if (lex.isInvalid() || rex.isInvalid()) + return QualType(); + + if (!lex.get()->getType()->isIntegerType() || !rex.get()->getType()->isIntegerType()) + return InvalidOperands(Loc, lex, rex); + + // Check for remainder by zero. + if (rex.get()->isNullPointerConstant(Context, Expr::NPC_ValueDependentIsNotNull)) + DiagRuntimeBehavior(Loc, rex.get(), PDiag(diag::warn_remainder_by_zero) + << rex.get()->getSourceRange()); + + return compType; +} + +QualType Sema::CheckAdditionOperands( // C99 6.5.6 + ExprResult &lex, ExprResult &rex, SourceLocation Loc, QualType* CompLHSTy) { + if (lex.get()->getType()->isVectorType() || rex.get()->getType()->isVectorType()) { + QualType compType = CheckVectorOperands(Loc, lex, rex); + if (CompLHSTy) *CompLHSTy = compType; + return compType; + } + + QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); + if (lex.isInvalid() || rex.isInvalid()) + return QualType(); + + // handle the common case first (both operands are arithmetic). + if (lex.get()->getType()->isArithmeticType() && + rex.get()->getType()->isArithmeticType()) { + if (CompLHSTy) *CompLHSTy = compType; + return compType; + } + + // Put any potential pointer into PExp + Expr* PExp = lex.get(), *IExp = rex.get(); + if (IExp->getType()->isAnyPointerType()) + std::swap(PExp, IExp); + + if (PExp->getType()->isAnyPointerType()) { + + if (IExp->getType()->isIntegerType()) { + QualType PointeeTy = PExp->getType()->getPointeeType(); + + // Check for arithmetic on pointers to incomplete types. + if (PointeeTy->isVoidType()) { + if (getLangOptions().CPlusPlus) { + Diag(Loc, diag::err_typecheck_pointer_arith_void_type) + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); + } + + // GNU extension: arithmetic on pointer to void + Diag(Loc, diag::ext_gnu_void_ptr) + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } else if (PointeeTy->isFunctionType()) { + if (getLangOptions().CPlusPlus) { + Diag(Loc, diag::err_typecheck_pointer_arith_function_type) + << lex.get()->getType() << lex.get()->getSourceRange(); + return QualType(); + } + + // GNU extension: arithmetic on pointer to function + Diag(Loc, diag::ext_gnu_ptr_func_arith) + << lex.get()->getType() << lex.get()->getSourceRange(); + } else { + // Check if we require a complete type. + if (((PExp->getType()->isPointerType() && + !PExp->getType()->isDependentType()) || + PExp->getType()->isObjCObjectPointerType()) && + RequireCompleteType(Loc, PointeeTy, + PDiag(diag::err_typecheck_arithmetic_incomplete_type) + << PExp->getSourceRange() + << PExp->getType())) + return QualType(); + } + // Diagnose bad cases where we step over interface counts. + if (PointeeTy->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { + Diag(Loc, diag::err_arithmetic_nonfragile_interface) + << PointeeTy << PExp->getSourceRange(); + return QualType(); + } + + if (CompLHSTy) { + QualType LHSTy = Context.isPromotableBitField(lex.get()); + if (LHSTy.isNull()) { + LHSTy = lex.get()->getType(); + if (LHSTy->isPromotableIntegerType()) + LHSTy = Context.getPromotedIntegerType(LHSTy); + } + *CompLHSTy = LHSTy; + } + return PExp->getType(); + } + } + + return InvalidOperands(Loc, lex, rex); +} + +// C99 6.5.6 +QualType Sema::CheckSubtractionOperands(ExprResult &lex, ExprResult &rex, + SourceLocation Loc, QualType* CompLHSTy) { + if (lex.get()->getType()->isVectorType() || rex.get()->getType()->isVectorType()) { + QualType compType = CheckVectorOperands(Loc, lex, rex); + if (CompLHSTy) *CompLHSTy = compType; + return compType; + } + + QualType compType = UsualArithmeticConversions(lex, rex, CompLHSTy); + if (lex.isInvalid() || rex.isInvalid()) + return QualType(); + + // Enforce type constraints: C99 6.5.6p3. + + // Handle the common case first (both operands are arithmetic). + if (lex.get()->getType()->isArithmeticType() && + rex.get()->getType()->isArithmeticType()) { + if (CompLHSTy) *CompLHSTy = compType; + return compType; + } + + // Either ptr - int or ptr - ptr. + if (lex.get()->getType()->isAnyPointerType()) { + QualType lpointee = lex.get()->getType()->getPointeeType(); + + // The LHS must be an completely-defined object type. + + bool ComplainAboutVoid = false; + Expr *ComplainAboutFunc = 0; + if (lpointee->isVoidType()) { + if (getLangOptions().CPlusPlus) { + Diag(Loc, diag::err_typecheck_pointer_arith_void_type) + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); + } + + // GNU C extension: arithmetic on pointer to void + ComplainAboutVoid = true; + } else if (lpointee->isFunctionType()) { + if (getLangOptions().CPlusPlus) { + Diag(Loc, diag::err_typecheck_pointer_arith_function_type) + << lex.get()->getType() << lex.get()->getSourceRange(); + return QualType(); + } + + // GNU C extension: arithmetic on pointer to function + ComplainAboutFunc = lex.get(); + } else if (!lpointee->isDependentType() && + RequireCompleteType(Loc, lpointee, + PDiag(diag::err_typecheck_sub_ptr_object) + << lex.get()->getSourceRange() + << lex.get()->getType())) + return QualType(); + + // Diagnose bad cases where we step over interface counts. + if (lpointee->isObjCObjectType() && LangOpts.ObjCNonFragileABI) { + Diag(Loc, diag::err_arithmetic_nonfragile_interface) + << lpointee << lex.get()->getSourceRange(); + return QualType(); + } + + // The result type of a pointer-int computation is the pointer type. + if (rex.get()->getType()->isIntegerType()) { + if (ComplainAboutVoid) + Diag(Loc, diag::ext_gnu_void_ptr) + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + if (ComplainAboutFunc) + Diag(Loc, diag::ext_gnu_ptr_func_arith) + << ComplainAboutFunc->getType() + << ComplainAboutFunc->getSourceRange(); + + if (CompLHSTy) *CompLHSTy = lex.get()->getType(); + return lex.get()->getType(); + } + + // Handle pointer-pointer subtractions. + if (const PointerType *RHSPTy = rex.get()->getType()->getAs<PointerType>()) { + QualType rpointee = RHSPTy->getPointeeType(); + + // RHS must be a completely-type object type. + // Handle the GNU void* extension. + if (rpointee->isVoidType()) { + if (getLangOptions().CPlusPlus) { + Diag(Loc, diag::err_typecheck_pointer_arith_void_type) + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); + } + + ComplainAboutVoid = true; + } else if (rpointee->isFunctionType()) { + if (getLangOptions().CPlusPlus) { + Diag(Loc, diag::err_typecheck_pointer_arith_function_type) + << rex.get()->getType() << rex.get()->getSourceRange(); + return QualType(); + } + + // GNU extension: arithmetic on pointer to function + if (!ComplainAboutFunc) + ComplainAboutFunc = rex.get(); + } else if (!rpointee->isDependentType() && + RequireCompleteType(Loc, rpointee, + PDiag(diag::err_typecheck_sub_ptr_object) + << rex.get()->getSourceRange() + << rex.get()->getType())) + return QualType(); + + if (getLangOptions().CPlusPlus) { + // Pointee types must be the same: C++ [expr.add] + if (!Context.hasSameUnqualifiedType(lpointee, rpointee)) { + Diag(Loc, diag::err_typecheck_sub_ptr_compatible) + << lex.get()->getType() << rex.get()->getType() + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); + } + } else { + // Pointee types must be compatible C99 6.5.6p3 + if (!Context.typesAreCompatible( + Context.getCanonicalType(lpointee).getUnqualifiedType(), + Context.getCanonicalType(rpointee).getUnqualifiedType())) { + Diag(Loc, diag::err_typecheck_sub_ptr_compatible) + << lex.get()->getType() << rex.get()->getType() + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); + } + } + + if (ComplainAboutVoid) + Diag(Loc, diag::ext_gnu_void_ptr) + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + if (ComplainAboutFunc) + Diag(Loc, diag::ext_gnu_ptr_func_arith) + << ComplainAboutFunc->getType() + << ComplainAboutFunc->getSourceRange(); + + if (CompLHSTy) *CompLHSTy = lex.get()->getType(); + return Context.getPointerDiffType(); + } + } + + return InvalidOperands(Loc, lex, rex); +} + +static bool isScopedEnumerationType(QualType T) { + if (const EnumType *ET = dyn_cast<EnumType>(T)) + return ET->getDecl()->isScoped(); + return false; +} + +static void DiagnoseBadShiftValues(Sema& S, ExprResult &lex, ExprResult &rex, + SourceLocation Loc, unsigned Opc, + QualType LHSTy) { + llvm::APSInt Right; + // Check right/shifter operand + if (rex.get()->isValueDependent() || !rex.get()->isIntegerConstantExpr(Right, S.Context)) + return; + + if (Right.isNegative()) { + S.DiagRuntimeBehavior(Loc, rex.get(), + S.PDiag(diag::warn_shift_negative) + << rex.get()->getSourceRange()); + return; + } + llvm::APInt LeftBits(Right.getBitWidth(), + S.Context.getTypeSize(lex.get()->getType())); + if (Right.uge(LeftBits)) { + S.DiagRuntimeBehavior(Loc, rex.get(), + S.PDiag(diag::warn_shift_gt_typewidth) + << rex.get()->getSourceRange()); + return; + } + if (Opc != BO_Shl) + return; + + // When left shifting an ICE which is signed, we can check for overflow which + // according to C++ has undefined behavior ([expr.shift] 5.8/2). Unsigned + // integers have defined behavior modulo one more than the maximum value + // representable in the result type, so never warn for those. + llvm::APSInt Left; + if (lex.get()->isValueDependent() || !lex.get()->isIntegerConstantExpr(Left, S.Context) || + LHSTy->hasUnsignedIntegerRepresentation()) + return; + llvm::APInt ResultBits = + static_cast<llvm::APInt&>(Right) + Left.getMinSignedBits(); + if (LeftBits.uge(ResultBits)) + return; + llvm::APSInt Result = Left.extend(ResultBits.getLimitedValue()); + Result = Result.shl(Right); + + // If we are only missing a sign bit, this is less likely to result in actual + // bugs -- if the result is cast back to an unsigned type, it will have the + // expected value. Thus we place this behind a different warning that can be + // turned off separately if needed. + if (LeftBits == ResultBits - 1) { + S.Diag(Loc, diag::warn_shift_result_overrides_sign_bit) + << Result.toString(10) << LHSTy + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return; + } + + S.Diag(Loc, diag::warn_shift_result_gt_typewidth) + << Result.toString(10) << Result.getMinSignedBits() << LHSTy + << Left.getBitWidth() << lex.get()->getSourceRange() << rex.get()->getSourceRange(); +} + +// C99 6.5.7 +QualType Sema::CheckShiftOperands(ExprResult &lex, ExprResult &rex, SourceLocation Loc, + unsigned Opc, bool isCompAssign) { + // C99 6.5.7p2: Each of the operands shall have integer type. + if (!lex.get()->getType()->hasIntegerRepresentation() || + !rex.get()->getType()->hasIntegerRepresentation()) + return InvalidOperands(Loc, lex, rex); + + // C++0x: Don't allow scoped enums. FIXME: Use something better than + // hasIntegerRepresentation() above instead of this. + if (isScopedEnumerationType(lex.get()->getType()) || + isScopedEnumerationType(rex.get()->getType())) { + return InvalidOperands(Loc, lex, rex); + } + + // Vector shifts promote their scalar inputs to vector type. + if (lex.get()->getType()->isVectorType() || rex.get()->getType()->isVectorType()) + return CheckVectorOperands(Loc, lex, rex); + + // Shifts don't perform usual arithmetic conversions, they just do integer + // promotions on each operand. C99 6.5.7p3 + + // For the LHS, do usual unary conversions, but then reset them away + // if this is a compound assignment. + ExprResult old_lex = lex; + lex = UsualUnaryConversions(lex.take()); + if (lex.isInvalid()) + return QualType(); + QualType LHSTy = lex.get()->getType(); + if (isCompAssign) lex = old_lex; + + // The RHS is simpler. + rex = UsualUnaryConversions(rex.take()); + if (rex.isInvalid()) + return QualType(); + + // Sanity-check shift operands + DiagnoseBadShiftValues(*this, lex, rex, Loc, Opc, LHSTy); + + // "The type of the result is that of the promoted left operand." + return LHSTy; +} + +static bool IsWithinTemplateSpecialization(Decl *D) { + if (DeclContext *DC = D->getDeclContext()) { + if (isa<ClassTemplateSpecializationDecl>(DC)) + return true; + if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) + return FD->isFunctionTemplateSpecialization(); + } + return false; +} + +// C99 6.5.8, C++ [expr.rel] +QualType Sema::CheckCompareOperands(ExprResult &lex, ExprResult &rex, SourceLocation Loc, + unsigned OpaqueOpc, bool isRelational) { + BinaryOperatorKind Opc = (BinaryOperatorKind) OpaqueOpc; + + // Handle vector comparisons separately. + if (lex.get()->getType()->isVectorType() || rex.get()->getType()->isVectorType()) + return CheckVectorCompareOperands(lex, rex, Loc, isRelational); + + QualType lType = lex.get()->getType(); + QualType rType = rex.get()->getType(); + + Expr *LHSStripped = lex.get()->IgnoreParenImpCasts(); + Expr *RHSStripped = rex.get()->IgnoreParenImpCasts(); + QualType LHSStrippedType = LHSStripped->getType(); + QualType RHSStrippedType = RHSStripped->getType(); + + + + // Two different enums will raise a warning when compared. + if (const EnumType *LHSEnumType = LHSStrippedType->getAs<EnumType>()) { + if (const EnumType *RHSEnumType = RHSStrippedType->getAs<EnumType>()) { + if (LHSEnumType->getDecl()->getIdentifier() && + RHSEnumType->getDecl()->getIdentifier() && + !Context.hasSameUnqualifiedType(LHSStrippedType, RHSStrippedType)) { + Diag(Loc, diag::warn_comparison_of_mixed_enum_types) + << LHSStrippedType << RHSStrippedType + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + } + } + + if (!lType->hasFloatingRepresentation() && + !(lType->isBlockPointerType() && isRelational) && + !lex.get()->getLocStart().isMacroID() && + !rex.get()->getLocStart().isMacroID()) { + // For non-floating point types, check for self-comparisons of the form + // x == x, x != x, x < x, etc. These always evaluate to a constant, and + // often indicate logic errors in the program. + // + // NOTE: Don't warn about comparison expressions resulting from macro + // expansion. Also don't warn about comparisons which are only self + // comparisons within a template specialization. The warnings should catch + // obvious cases in the definition of the template anyways. The idea is to + // warn when the typed comparison operator will always evaluate to the same + // result. + if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(LHSStripped)) { + if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(RHSStripped)) { + if (DRL->getDecl() == DRR->getDecl() && + !IsWithinTemplateSpecialization(DRL->getDecl())) { + DiagRuntimeBehavior(Loc, 0, PDiag(diag::warn_comparison_always) + << 0 // self- + << (Opc == BO_EQ + || Opc == BO_LE + || Opc == BO_GE)); + } else if (lType->isArrayType() && rType->isArrayType() && + !DRL->getDecl()->getType()->isReferenceType() && + !DRR->getDecl()->getType()->isReferenceType()) { + // what is it always going to eval to? + char always_evals_to; + switch(Opc) { + case BO_EQ: // e.g. array1 == array2 + always_evals_to = 0; // false + break; + case BO_NE: // e.g. array1 != array2 + always_evals_to = 1; // true + break; + default: + // best we can say is 'a constant' + always_evals_to = 2; // e.g. array1 <= array2 + break; + } + DiagRuntimeBehavior(Loc, 0, PDiag(diag::warn_comparison_always) + << 1 // array + << always_evals_to); + } + } + } + + if (isa<CastExpr>(LHSStripped)) + LHSStripped = LHSStripped->IgnoreParenCasts(); + if (isa<CastExpr>(RHSStripped)) + RHSStripped = RHSStripped->IgnoreParenCasts(); + + // Warn about comparisons against a string constant (unless the other + // operand is null), the user probably wants strcmp. + Expr *literalString = 0; + Expr *literalStringStripped = 0; + if ((isa<StringLiteral>(LHSStripped) || isa<ObjCEncodeExpr>(LHSStripped)) && + !RHSStripped->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNull)) { + literalString = lex.get(); + literalStringStripped = LHSStripped; + } else if ((isa<StringLiteral>(RHSStripped) || + isa<ObjCEncodeExpr>(RHSStripped)) && + !LHSStripped->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNull)) { + literalString = rex.get(); + literalStringStripped = RHSStripped; + } + + if (literalString) { + std::string resultComparison; + switch (Opc) { + case BO_LT: resultComparison = ") < 0"; break; + case BO_GT: resultComparison = ") > 0"; break; + case BO_LE: resultComparison = ") <= 0"; break; + case BO_GE: resultComparison = ") >= 0"; break; + case BO_EQ: resultComparison = ") == 0"; break; + case BO_NE: resultComparison = ") != 0"; break; + default: assert(false && "Invalid comparison operator"); + } + + DiagRuntimeBehavior(Loc, 0, + PDiag(diag::warn_stringcompare) + << isa<ObjCEncodeExpr>(literalStringStripped) + << literalString->getSourceRange()); + } + } + + // C99 6.5.8p3 / C99 6.5.9p4 + if (lex.get()->getType()->isArithmeticType() && rex.get()->getType()->isArithmeticType()) { + UsualArithmeticConversions(lex, rex); + if (lex.isInvalid() || rex.isInvalid()) + return QualType(); + } + else { + lex = UsualUnaryConversions(lex.take()); + if (lex.isInvalid()) + return QualType(); + + rex = UsualUnaryConversions(rex.take()); + if (rex.isInvalid()) + return QualType(); + } + + lType = lex.get()->getType(); + rType = rex.get()->getType(); + + // The result of comparisons is 'bool' in C++, 'int' in C. + QualType ResultTy = Context.getLogicalOperationType(); + + if (isRelational) { + if (lType->isRealType() && rType->isRealType()) + return ResultTy; + } else { + // Check for comparisons of floating point operands using != and ==. + if (lType->hasFloatingRepresentation()) + CheckFloatComparison(Loc, lex.get(), rex.get()); + + if (lType->isArithmeticType() && rType->isArithmeticType()) + return ResultTy; + } + + bool LHSIsNull = lex.get()->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNull); + bool RHSIsNull = rex.get()->isNullPointerConstant(Context, + Expr::NPC_ValueDependentIsNull); + + // All of the following pointer-related warnings are GCC extensions, except + // when handling null pointer constants. + if (lType->isPointerType() && rType->isPointerType()) { // C99 6.5.8p2 + QualType LCanPointeeTy = + Context.getCanonicalType(lType->getAs<PointerType>()->getPointeeType()); + QualType RCanPointeeTy = + Context.getCanonicalType(rType->getAs<PointerType>()->getPointeeType()); + + if (getLangOptions().CPlusPlus) { + if (LCanPointeeTy == RCanPointeeTy) + return ResultTy; + if (!isRelational && + (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { + // Valid unless comparison between non-null pointer and function pointer + // This is a gcc extension compatibility comparison. + // In a SFINAE context, we treat this as a hard error to maintain + // conformance with the C++ standard. + if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) + && !LHSIsNull && !RHSIsNull) { + Diag(Loc, + isSFINAEContext()? + diag::err_typecheck_comparison_of_fptr_to_void + : diag::ext_typecheck_comparison_of_fptr_to_void) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + + if (isSFINAEContext()) + return QualType(); + + rex = ImpCastExprToType(rex.take(), lType, CK_BitCast); + return ResultTy; + } + } + + // C++ [expr.rel]p2: + // [...] Pointer conversions (4.10) and qualification + // conversions (4.4) are performed on pointer operands (or on + // a pointer operand and a null pointer constant) to bring + // them to their composite pointer type. [...] + // + // C++ [expr.eq]p1 uses the same notion for (in)equality + // comparisons of pointers. + bool NonStandardCompositeType = false; + QualType T = FindCompositePointerType(Loc, lex, rex, + isSFINAEContext()? 0 : &NonStandardCompositeType); + if (T.isNull()) { + Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); + } else if (NonStandardCompositeType) { + Diag(Loc, + diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) + << lType << rType << T + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + + lex = ImpCastExprToType(lex.take(), T, CK_BitCast); + rex = ImpCastExprToType(rex.take(), T, CK_BitCast); + return ResultTy; + } + // C99 6.5.9p2 and C99 6.5.8p2 + if (Context.typesAreCompatible(LCanPointeeTy.getUnqualifiedType(), + RCanPointeeTy.getUnqualifiedType())) { + // Valid unless a relational comparison of function pointers + if (isRelational && LCanPointeeTy->isFunctionType()) { + Diag(Loc, diag::ext_typecheck_ordered_comparison_of_function_pointers) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + } else if (!isRelational && + (LCanPointeeTy->isVoidType() || RCanPointeeTy->isVoidType())) { + // Valid unless comparison between non-null pointer and function pointer + if ((LCanPointeeTy->isFunctionType() || RCanPointeeTy->isFunctionType()) + && !LHSIsNull && !RHSIsNull) { + Diag(Loc, diag::ext_typecheck_comparison_of_fptr_to_void) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + } else { + // Invalid + Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + if (LCanPointeeTy != RCanPointeeTy) { + if (LHSIsNull && !RHSIsNull) + lex = ImpCastExprToType(lex.take(), rType, CK_BitCast); + else + rex = ImpCastExprToType(rex.take(), lType, CK_BitCast); + } + return ResultTy; + } + + if (getLangOptions().CPlusPlus) { + // Comparison of nullptr_t with itself. + if (lType->isNullPtrType() && rType->isNullPtrType()) + return ResultTy; + + // Comparison of pointers with null pointer constants and equality + // comparisons of member pointers to null pointer constants. + if (RHSIsNull && + ((lType->isPointerType() || lType->isNullPtrType()) || + (!isRelational && lType->isMemberPointerType()))) { + rex = ImpCastExprToType(rex.take(), lType, + lType->isMemberPointerType() + ? CK_NullToMemberPointer + : CK_NullToPointer); + return ResultTy; + } + if (LHSIsNull && + ((rType->isPointerType() || rType->isNullPtrType()) || + (!isRelational && rType->isMemberPointerType()))) { + lex = ImpCastExprToType(lex.take(), rType, + rType->isMemberPointerType() + ? CK_NullToMemberPointer + : CK_NullToPointer); + return ResultTy; + } + + // Comparison of member pointers. + if (!isRelational && + lType->isMemberPointerType() && rType->isMemberPointerType()) { + // C++ [expr.eq]p2: + // In addition, pointers to members can be compared, or a pointer to + // member and a null pointer constant. Pointer to member conversions + // (4.11) and qualification conversions (4.4) are performed to bring + // them to a common type. If one operand is a null pointer constant, + // the common type is the type of the other operand. Otherwise, the + // common type is a pointer to member type similar (4.4) to the type + // of one of the operands, with a cv-qualification signature (4.4) + // that is the union of the cv-qualification signatures of the operand + // types. + bool NonStandardCompositeType = false; + QualType T = FindCompositePointerType(Loc, lex, rex, + isSFINAEContext()? 0 : &NonStandardCompositeType); + if (T.isNull()) { + Diag(Loc, diag::err_typecheck_comparison_of_distinct_pointers) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + return QualType(); + } else if (NonStandardCompositeType) { + Diag(Loc, + diag::ext_typecheck_comparison_of_distinct_pointers_nonstandard) + << lType << rType << T + << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + + lex = ImpCastExprToType(lex.take(), T, CK_BitCast); + rex = ImpCastExprToType(rex.take(), T, CK_BitCast); + return ResultTy; + } + + // Handle scoped enumeration types specifically, since they don't promote + // to integers. + if (lex.get()->getType()->isEnumeralType() && + Context.hasSameUnqualifiedType(lex.get()->getType(), rex.get()->getType())) + return ResultTy; + } + + // Handle block pointer types. + if (!isRelational && lType->isBlockPointerType() && rType->isBlockPointerType()) { + QualType lpointee = lType->getAs<BlockPointerType>()->getPointeeType(); + QualType rpointee = rType->getAs<BlockPointerType>()->getPointeeType(); + + if (!LHSIsNull && !RHSIsNull && + !Context.typesAreCompatible(lpointee, rpointee)) { + Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + rex = ImpCastExprToType(rex.take(), lType, CK_BitCast); + return ResultTy; + } + + // Allow block pointers to be compared with null pointer constants. + if (!isRelational + && ((lType->isBlockPointerType() && rType->isPointerType()) + || (lType->isPointerType() && rType->isBlockPointerType()))) { + if (!LHSIsNull && !RHSIsNull) { + if (!((rType->isPointerType() && rType->castAs<PointerType>() + ->getPointeeType()->isVoidType()) + || (lType->isPointerType() && lType->castAs<PointerType>() + ->getPointeeType()->isVoidType()))) + Diag(Loc, diag::err_typecheck_comparison_of_distinct_blocks) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + if (LHSIsNull && !RHSIsNull) + lex = ImpCastExprToType(lex.take(), rType, CK_BitCast); + else + rex = ImpCastExprToType(rex.take(), lType, CK_BitCast); + return ResultTy; + } + + if (lType->isObjCObjectPointerType() || rType->isObjCObjectPointerType()) { + const PointerType *LPT = lType->getAs<PointerType>(); + const PointerType *RPT = rType->getAs<PointerType>(); + if (LPT || RPT) { + bool LPtrToVoid = LPT ? LPT->getPointeeType()->isVoidType() : false; + bool RPtrToVoid = RPT ? RPT->getPointeeType()->isVoidType() : false; + + if (!LPtrToVoid && !RPtrToVoid && + !Context.typesAreCompatible(lType, rType)) { + Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + } + if (LHSIsNull && !RHSIsNull) + lex = ImpCastExprToType(lex.take(), rType, CK_BitCast); + else + rex = ImpCastExprToType(rex.take(), lType, CK_BitCast); + return ResultTy; + } + if (lType->isObjCObjectPointerType() && rType->isObjCObjectPointerType()) { + if (!Context.areComparableObjCPointerTypes(lType, rType)) + Diag(Loc, diag::ext_typecheck_comparison_of_distinct_pointers) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + if (LHSIsNull && !RHSIsNull) + lex = ImpCastExprToType(lex.take(), rType, CK_BitCast); + else + rex = ImpCastExprToType(rex.take(), lType, CK_BitCast); + return ResultTy; + } + } + if ((lType->isAnyPointerType() && rType->isIntegerType()) || + (lType->isIntegerType() && rType->isAnyPointerType())) { + unsigned DiagID = 0; + bool isError = false; + if ((LHSIsNull && lType->isIntegerType()) || + (RHSIsNull && rType->isIntegerType())) { + if (isRelational && !getLangOptions().CPlusPlus) + DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_and_zero; + } else if (isRelational && !getLangOptions().CPlusPlus) + DiagID = diag::ext_typecheck_ordered_comparison_of_pointer_integer; + else if (getLangOptions().CPlusPlus) { + DiagID = diag::err_typecheck_comparison_of_pointer_integer; + isError = true; + } else + DiagID = diag::ext_typecheck_comparison_of_pointer_integer; + + if (DiagID) { + Diag(Loc, DiagID) + << lType << rType << lex.get()->getSourceRange() << rex.get()->getSourceRange(); + if (isError) + return QualType(); + } + + if (lType->isIntegerType()) + lex = ImpCastExprToType(lex.take(), rType, + LHSIsNull ? CK_NullToPointer : CK_IntegralToPointer); + else + rex = ImpCastExprToType(rex.take(), lType, + RHSIsNull ? CK_NullToPointer : CK_IntegralToPointer); + return ResultTy; + } + + // Handle block pointers. + if (!isRelational && RHSIsNull + && lType->isBlockPointerType() && rType->isIntegerType()) { + rex = ImpCastExprToType(rex.take(), lType, CK_NullToPointer); + return ResultTy; + } + if (!isRelational && LHSIsNull + && lType->isIntegerType() && rType->isBlockPointerType()) { + lex = ImpCastExprToType(lex.take(), rType, CK_NullToPointer); + return ResultTy; + } + + return InvalidOperands(Loc, lex, rex); +} + +/// CheckVectorCompareOperands - vector comparisons are a clang extension that +/// operates on extended vector types. Instead of producing an IntTy result, +/// like a scalar comparison, a vector comparison produces a vector of integer +/// types. +QualType Sema::CheckVectorCompareOperands(ExprResult &lex, ExprResult &rex, + SourceLocation Loc, + bool isRelational) { + // Check to make sure we're operating on vectors of the same type and width, + // Allowing one side to be a scalar of element type. + QualType vType = CheckVectorOperands(Loc, lex, rex); + if (vType.isNull()) + return vType; + + QualType lType = lex.get()->getType(); + QualType rType = rex.get()->getType(); + + // If AltiVec, the comparison results in a numeric type, i.e. + // bool for C++, int for C + if (vType->getAs<VectorType>()->getVectorKind() == VectorType::AltiVecVector) + return Context.getLogicalOperationType(); + + // For non-floating point types, check for self-comparisons of the form + // x == x, x != x, x < x, etc. These always evaluate to a constant, and + // often indicate logic errors in the program. + if (!lType->hasFloatingRepresentation()) { + if (DeclRefExpr* DRL = dyn_cast<DeclRefExpr>(lex.get()->IgnoreParens())) + if (DeclRefExpr* DRR = dyn_cast<DeclRefExpr>(rex.get()->IgnoreParens())) + if (DRL->getDecl() == DRR->getDecl()) + DiagRuntimeBehavior(Loc, 0, + PDiag(diag::warn_comparison_always) + << 0 // self- + << 2 // "a constant" + ); + } + + // Check for comparisons of floating point operands using != and ==. + if (!isRelational && lType->hasFloatingRepresentation()) { + assert (rType->hasFloatingRepresentation()); + CheckFloatComparison(Loc, lex.get(), rex.get()); + } + + // Return the type for the comparison, which is the same as vector type for + // integer vectors, or an integer type of identical size and number of + // elements for floating point vectors. + if (lType->hasIntegerRepresentation()) + return lType; + + const VectorType *VTy = lType->getAs<VectorType>(); + unsigned TypeSize = Context.getTypeSize(VTy->getElementType()); + if (TypeSize == Context.getTypeSize(Context.IntTy)) + return Context.getExtVectorType(Context.IntTy, VTy->getNumElements()); + if (TypeSize == Context.getTypeSize(Context.LongTy)) + return Context.getExtVectorType(Context.LongTy, VTy->getNumElements()); + + assert(TypeSize == Context.getTypeSize(Context.LongLongTy) && + "Unhandled vector element size in vector compare"); + return Context.getExtVectorType(Context.LongLongTy, VTy->getNumElements()); +} + +inline QualType Sema::CheckBitwiseOperands( + ExprResult &lex, ExprResult &rex, SourceLocation Loc, bool isCompAssign) { + if (lex.get()->getType()->isVectorType() || rex.get()->getType()->isVectorType()) { + if (lex.get()->getType()->hasIntegerRepresentation() && + rex.get()->getType()->hasIntegerRepresentation()) + return CheckVectorOperands(Loc, lex, rex); + + return InvalidOperands(Loc, lex, rex); + } + + ExprResult lexResult = Owned(lex), rexResult = Owned(rex); + QualType compType = UsualArithmeticConversions(lexResult, rexResult, isCompAssign); + if (lexResult.isInvalid() || rexResult.isInvalid()) + return QualType(); + lex = lexResult.take(); + rex = rexResult.take(); + + if (lex.get()->getType()->isIntegralOrUnscopedEnumerationType() && + rex.get()->getType()->isIntegralOrUnscopedEnumerationType()) + return compType; + return InvalidOperands(Loc, lex, rex); +} + +inline QualType Sema::CheckLogicalOperands( // C99 6.5.[13,14] + ExprResult &lex, ExprResult &rex, SourceLocation Loc, unsigned Opc) { + + // Diagnose cases where the user write a logical and/or but probably meant a + // bitwise one. We do this when the LHS is a non-bool integer and the RHS + // is a constant. + if (lex.get()->getType()->isIntegerType() && !lex.get()->getType()->isBooleanType() && + rex.get()->getType()->isIntegerType() && !rex.get()->isValueDependent() && + // Don't warn in macros. + !Loc.isMacroID()) { + // If the RHS can be constant folded, and if it constant folds to something + // that isn't 0 or 1 (which indicate a potential logical operation that + // happened to fold to true/false) then warn. + Expr::EvalResult Result; + if (rex.get()->Evaluate(Result, Context) && !Result.HasSideEffects && + Result.Val.getInt() != 0 && Result.Val.getInt() != 1) { + Diag(Loc, diag::warn_logical_instead_of_bitwise) + << rex.get()->getSourceRange() + << (Opc == BO_LAnd ? "&&" : "||") + << (Opc == BO_LAnd ? "&" : "|"); + } + } + + if (!Context.getLangOptions().CPlusPlus) { + lex = UsualUnaryConversions(lex.take()); + if (lex.isInvalid()) + return QualType(); + + rex = UsualUnaryConversions(rex.take()); + if (rex.isInvalid()) + return QualType(); + + if (!lex.get()->getType()->isScalarType() || !rex.get()->getType()->isScalarType()) + return InvalidOperands(Loc, lex, rex); + + return Context.IntTy; + } + + // The following is safe because we only use this method for + // non-overloadable operands. + + // C++ [expr.log.and]p1 + // C++ [expr.log.or]p1 + // The operands are both contextually converted to type bool. + ExprResult lexRes = PerformContextuallyConvertToBool(lex.get()); + if (lexRes.isInvalid()) + return InvalidOperands(Loc, lex, rex); + lex = move(lexRes); + + ExprResult rexRes = PerformContextuallyConvertToBool(rex.get()); + if (rexRes.isInvalid()) + return InvalidOperands(Loc, lex, rex); + rex = move(rexRes); + + // C++ [expr.log.and]p2 + // C++ [expr.log.or]p2 + // The result is a bool. + return Context.BoolTy; +} + +/// IsReadonlyProperty - Verify that otherwise a valid l-value expression +/// is a read-only property; return true if so. A readonly property expression +/// depends on various declarations and thus must be treated specially. +/// +static bool IsReadonlyProperty(Expr *E, Sema &S) { + if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { + const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); + if (PropExpr->isImplicitProperty()) return false; + + ObjCPropertyDecl *PDecl = PropExpr->getExplicitProperty(); + QualType BaseType = PropExpr->isSuperReceiver() ? + PropExpr->getSuperReceiverType() : + PropExpr->getBase()->getType(); + + if (const ObjCObjectPointerType *OPT = + BaseType->getAsObjCInterfacePointerType()) + if (ObjCInterfaceDecl *IFace = OPT->getInterfaceDecl()) + if (S.isPropertyReadonly(PDecl, IFace)) + return true; + } + return false; +} + +static bool IsConstProperty(Expr *E, Sema &S) { + if (E->getStmtClass() == Expr::ObjCPropertyRefExprClass) { + const ObjCPropertyRefExpr* PropExpr = cast<ObjCPropertyRefExpr>(E); + if (PropExpr->isImplicitProperty()) return false; + + ObjCPropertyDecl *PDecl = PropExpr->getExplicitProperty(); + QualType T = PDecl->getType(); + if (T->isReferenceType()) + T = T->getAs<ReferenceType>()->getPointeeType(); + CanQualType CT = S.Context.getCanonicalType(T); + return CT.isConstQualified(); + } + return false; +} + +static bool IsReadonlyMessage(Expr *E, Sema &S) { + if (E->getStmtClass() != Expr::MemberExprClass) + return false; + const MemberExpr *ME = cast<MemberExpr>(E); + NamedDecl *Member = ME->getMemberDecl(); + if (isa<FieldDecl>(Member)) { + Expr *Base = ME->getBase()->IgnoreParenImpCasts(); + if (Base->getStmtClass() != Expr::ObjCMessageExprClass) + return false; + return cast<ObjCMessageExpr>(Base)->getMethodDecl() != 0; + } + return false; +} + +/// CheckForModifiableLvalue - Verify that E is a modifiable lvalue. If not, +/// emit an error and return true. If so, return false. +static bool CheckForModifiableLvalue(Expr *E, SourceLocation Loc, Sema &S) { + SourceLocation OrigLoc = Loc; + Expr::isModifiableLvalueResult IsLV = E->isModifiableLvalue(S.Context, + &Loc); + if (IsLV == Expr::MLV_Valid && IsReadonlyProperty(E, S)) + IsLV = Expr::MLV_ReadonlyProperty; + else if (Expr::MLV_ConstQualified && IsConstProperty(E, S)) + IsLV = Expr::MLV_Valid; + else if (IsLV == Expr::MLV_ClassTemporary && IsReadonlyMessage(E, S)) + IsLV = Expr::MLV_InvalidMessageExpression; + if (IsLV == Expr::MLV_Valid) + return false; + + unsigned Diag = 0; + bool NeedType = false; + switch (IsLV) { // C99 6.5.16p2 + case Expr::MLV_ConstQualified: Diag = diag::err_typecheck_assign_const; break; + case Expr::MLV_ArrayType: + Diag = diag::err_typecheck_array_not_modifiable_lvalue; + NeedType = true; + break; + case Expr::MLV_NotObjectType: + Diag = diag::err_typecheck_non_object_not_modifiable_lvalue; + NeedType = true; + break; + case Expr::MLV_LValueCast: + Diag = diag::err_typecheck_lvalue_casts_not_supported; + break; + case Expr::MLV_Valid: + llvm_unreachable("did not take early return for MLV_Valid"); + case Expr::MLV_InvalidExpression: + case Expr::MLV_MemberFunction: + case Expr::MLV_ClassTemporary: + Diag = diag::err_typecheck_expression_not_modifiable_lvalue; + break; + case Expr::MLV_IncompleteType: + case Expr::MLV_IncompleteVoidType: + return S.RequireCompleteType(Loc, E->getType(), + S.PDiag(diag::err_typecheck_incomplete_type_not_modifiable_lvalue) + << E->getSourceRange()); + case Expr::MLV_DuplicateVectorComponents: + Diag = diag::err_typecheck_duplicate_vector_components_not_mlvalue; + break; + case Expr::MLV_NotBlockQualified: + Diag = diag::err_block_decl_ref_not_modifiable_lvalue; + break; + case Expr::MLV_ReadonlyProperty: + Diag = diag::error_readonly_property_assignment; + break; + case Expr::MLV_NoSetterProperty: + Diag = diag::error_nosetter_property_assignment; + break; + case Expr::MLV_InvalidMessageExpression: + Diag = diag::error_readonly_message_assignment; + break; + case Expr::MLV_SubObjCPropertySetting: + Diag = diag::error_no_subobject_property_setting; + break; + } + + SourceRange Assign; + if (Loc != OrigLoc) + Assign = SourceRange(OrigLoc, OrigLoc); + if (NeedType) + S.Diag(Loc, Diag) << E->getType() << E->getSourceRange() << Assign; + else + S.Diag(Loc, Diag) << E->getSourceRange() << Assign; + return true; +} + + + +// C99 6.5.16.1 +QualType Sema::CheckAssignmentOperands(Expr *LHS, ExprResult &RHS, + SourceLocation Loc, + QualType CompoundType) { + // Verify that LHS is a modifiable lvalue, and emit error if not. + if (CheckForModifiableLvalue(LHS, Loc, *this)) + return QualType(); + + QualType LHSType = LHS->getType(); + QualType RHSType = CompoundType.isNull() ? RHS.get()->getType() : CompoundType; + AssignConvertType ConvTy; + if (CompoundType.isNull()) { + QualType LHSTy(LHSType); + // Simple assignment "x = y". + if (LHS->getObjectKind() == OK_ObjCProperty) { + ExprResult LHSResult = Owned(LHS); + ConvertPropertyForLValue(LHSResult, RHS, LHSTy); + if (LHSResult.isInvalid()) + return QualType(); + LHS = LHSResult.take(); + } + ConvTy = CheckSingleAssignmentConstraints(LHSTy, RHS); + if (RHS.isInvalid()) + return QualType(); + // Special case of NSObject attributes on c-style pointer types. + if (ConvTy == IncompatiblePointer && + ((Context.isObjCNSObjectType(LHSType) && + RHSType->isObjCObjectPointerType()) || + (Context.isObjCNSObjectType(RHSType) && + LHSType->isObjCObjectPointerType()))) + ConvTy = Compatible; + + if (ConvTy == Compatible && + getLangOptions().ObjCNonFragileABI && + LHSType->isObjCObjectType()) + Diag(Loc, diag::err_assignment_requires_nonfragile_object) + << LHSType; + + // If the RHS is a unary plus or minus, check to see if they = and + are + // right next to each other. If so, the user may have typo'd "x =+ 4" + // instead of "x += 4". + Expr *RHSCheck = RHS.get(); + if (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(RHSCheck)) + RHSCheck = ICE->getSubExpr(); + if (UnaryOperator *UO = dyn_cast<UnaryOperator>(RHSCheck)) { + if ((UO->getOpcode() == UO_Plus || + UO->getOpcode() == UO_Minus) && + Loc.isFileID() && UO->getOperatorLoc().isFileID() && + // Only if the two operators are exactly adjacent. + Loc.getFileLocWithOffset(1) == UO->getOperatorLoc() && + // And there is a space or other character before the subexpr of the + // unary +/-. We don't want to warn on "x=-1". + Loc.getFileLocWithOffset(2) != UO->getSubExpr()->getLocStart() && + UO->getSubExpr()->getLocStart().isFileID()) { + Diag(Loc, diag::warn_not_compound_assign) + << (UO->getOpcode() == UO_Plus ? "+" : "-") + << SourceRange(UO->getOperatorLoc(), UO->getOperatorLoc()); + } + } + } else { + // Compound assignment "x += y" + ConvTy = CheckAssignmentConstraints(Loc, LHSType, RHSType); + } + + if (DiagnoseAssignmentResult(ConvTy, Loc, LHSType, RHSType, + RHS.get(), AA_Assigning)) + return QualType(); + + CheckForNullPointerDereference(*this, LHS); + // Check for trivial buffer overflows. + CheckArrayAccess(LHS->IgnoreParenCasts()); + + // C99 6.5.16p3: The type of an assignment expression is the type of the + // left operand unless the left operand has qualified type, in which case + // it is the unqualified version of the type of the left operand. + // C99 6.5.16.1p2: In simple assignment, the value of the right operand + // is converted to the type of the assignment expression (above). + // C++ 5.17p1: the type of the assignment expression is that of its left + // operand. + return (getLangOptions().CPlusPlus + ? LHSType : LHSType.getUnqualifiedType()); +} + +// C99 6.5.17 +static QualType CheckCommaOperands(Sema &S, ExprResult &LHS, ExprResult &RHS, + SourceLocation Loc) { + S.DiagnoseUnusedExprResult(LHS.get()); + + LHS = S.CheckPlaceholderExpr(LHS.take()); + RHS = S.CheckPlaceholderExpr(RHS.take()); + if (LHS.isInvalid() || RHS.isInvalid()) + return QualType(); + + // C's comma performs lvalue conversion (C99 6.3.2.1) on both its + // operands, but not unary promotions. + // C++'s comma does not do any conversions at all (C++ [expr.comma]p1). + + // So we treat the LHS as a ignored value, and in C++ we allow the + // containing site to determine what should be done with the RHS. + LHS = S.IgnoredValueConversions(LHS.take()); + if (LHS.isInvalid()) + return QualType(); + + if (!S.getLangOptions().CPlusPlus) { + RHS = S.DefaultFunctionArrayLvalueConversion(RHS.take()); + if (RHS.isInvalid()) + return QualType(); + if (!RHS.get()->getType()->isVoidType()) + S.RequireCompleteType(Loc, RHS.get()->getType(), diag::err_incomplete_type); + } + + return RHS.get()->getType(); +} + +/// CheckIncrementDecrementOperand - unlike most "Check" methods, this routine +/// doesn't need to call UsualUnaryConversions or UsualArithmeticConversions. +static QualType CheckIncrementDecrementOperand(Sema &S, Expr *Op, + ExprValueKind &VK, + SourceLocation OpLoc, + bool isInc, bool isPrefix) { + if (Op->isTypeDependent()) + return S.Context.DependentTy; + + QualType ResType = Op->getType(); + assert(!ResType.isNull() && "no type for increment/decrement expression"); + + if (S.getLangOptions().CPlusPlus && ResType->isBooleanType()) { + // Decrement of bool is not allowed. + if (!isInc) { + S.Diag(OpLoc, diag::err_decrement_bool) << Op->getSourceRange(); + return QualType(); + } + // Increment of bool sets it to true, but is deprecated. + S.Diag(OpLoc, diag::warn_increment_bool) << Op->getSourceRange(); + } else if (ResType->isRealType()) { + // OK! + } else if (ResType->isAnyPointerType()) { + QualType PointeeTy = ResType->getPointeeType(); + + // C99 6.5.2.4p2, 6.5.6p2 + if (PointeeTy->isVoidType()) { + if (S.getLangOptions().CPlusPlus) { + S.Diag(OpLoc, diag::err_typecheck_pointer_arith_void_type) + << Op->getSourceRange(); + return QualType(); + } + + // Pointer to void is a GNU extension in C. + S.Diag(OpLoc, diag::ext_gnu_void_ptr) << Op->getSourceRange(); + } else if (PointeeTy->isFunctionType()) { + if (S.getLangOptions().CPlusPlus) { + S.Diag(OpLoc, diag::err_typecheck_pointer_arith_function_type) + << Op->getType() << Op->getSourceRange(); + return QualType(); + } + + S.Diag(OpLoc, diag::ext_gnu_ptr_func_arith) + << ResType << Op->getSourceRange(); + } else if (S.RequireCompleteType(OpLoc, PointeeTy, + S.PDiag(diag::err_typecheck_arithmetic_incomplete_type) + << Op->getSourceRange() + << ResType)) + return QualType(); + // Diagnose bad cases where we step over interface counts. + else if (PointeeTy->isObjCObjectType() && S.LangOpts.ObjCNonFragileABI) { + S.Diag(OpLoc, diag::err_arithmetic_nonfragile_interface) + << PointeeTy << Op->getSourceRange(); + return QualType(); + } + } else if (ResType->isAnyComplexType()) { + // C99 does not support ++/-- on complex types, we allow as an extension. + S.Diag(OpLoc, diag::ext_integer_increment_complex) + << ResType << Op->getSourceRange(); + } else if (ResType->isPlaceholderType()) { + ExprResult PR = S.CheckPlaceholderExpr(Op); + if (PR.isInvalid()) return QualType(); + return CheckIncrementDecrementOperand(S, PR.take(), VK, OpLoc, + isInc, isPrefix); + } else if (S.getLangOptions().AltiVec && ResType->isVectorType()) { + // OK! ( C/C++ Language Extensions for CBEA(Version 2.6) 10.3 ) + } else { + S.Diag(OpLoc, diag::err_typecheck_illegal_increment_decrement) + << ResType << int(isInc) << Op->getSourceRange(); + return QualType(); + } + // At this point, we know we have a real, complex or pointer type. + // Now make sure the operand is a modifiable lvalue. + if (CheckForModifiableLvalue(Op, OpLoc, S)) + return QualType(); + // In C++, a prefix increment is the same type as the operand. Otherwise + // (in C or with postfix), the increment is the unqualified type of the + // operand. + if (isPrefix && S.getLangOptions().CPlusPlus) { + VK = VK_LValue; + return ResType; + } else { + VK = VK_RValue; + return ResType.getUnqualifiedType(); + } +} + +ExprResult Sema::ConvertPropertyForRValue(Expr *E) { + assert(E->getValueKind() == VK_LValue && + E->getObjectKind() == OK_ObjCProperty); + const ObjCPropertyRefExpr *PRE = E->getObjCProperty(); + + ExprValueKind VK = VK_RValue; + if (PRE->isImplicitProperty()) { + if (const ObjCMethodDecl *GetterMethod = + PRE->getImplicitPropertyGetter()) { + QualType Result = GetterMethod->getResultType(); + VK = Expr::getValueKindForType(Result); + } + else { + Diag(PRE->getLocation(), diag::err_getter_not_found) + << PRE->getBase()->getType(); + } + } + + E = ImplicitCastExpr::Create(Context, E->getType(), CK_GetObjCProperty, + E, 0, VK); + + ExprResult Result = MaybeBindToTemporary(E); + if (!Result.isInvalid()) + E = Result.take(); + + return Owned(E); +} + +void Sema::ConvertPropertyForLValue(ExprResult &LHS, ExprResult &RHS, QualType &LHSTy) { + assert(LHS.get()->getValueKind() == VK_LValue && + LHS.get()->getObjectKind() == OK_ObjCProperty); + const ObjCPropertyRefExpr *PropRef = LHS.get()->getObjCProperty(); + + if (PropRef->isImplicitProperty()) { + // If using property-dot syntax notation for assignment, and there is a + // setter, RHS expression is being passed to the setter argument. So, + // type conversion (and comparison) is RHS to setter's argument type. + if (const ObjCMethodDecl *SetterMD = PropRef->getImplicitPropertySetter()) { + ObjCMethodDecl::param_iterator P = SetterMD->param_begin(); + LHSTy = (*P)->getType(); + + // Otherwise, if the getter returns an l-value, just call that. + } else { + QualType Result = PropRef->getImplicitPropertyGetter()->getResultType(); + ExprValueKind VK = Expr::getValueKindForType(Result); + if (VK == VK_LValue) { + LHS = ImplicitCastExpr::Create(Context, LHS.get()->getType(), + CK_GetObjCProperty, LHS.take(), 0, VK); + return; + } + } + } + + if (getLangOptions().CPlusPlus && LHSTy->isRecordType()) { + InitializedEntity Entity = + InitializedEntity::InitializeParameter(Context, LHSTy); + ExprResult ArgE = PerformCopyInitialization(Entity, SourceLocation(), RHS); + if (!ArgE.isInvalid()) + RHS = ArgE; + } +} + + +/// getPrimaryDecl - Helper function for CheckAddressOfOperand(). +/// This routine allows us to typecheck complex/recursive expressions +/// where the declaration is needed for type checking. We only need to +/// handle cases when the expression references a function designator +/// or is an lvalue. Here are some examples: +/// - &(x) => x +/// - &*****f => f for f a function designator. +/// - &s.xx => s +/// - &s.zz[1].yy -> s, if zz is an array +/// - *(x + 1) -> x, if x is an array +/// - &"123"[2] -> 0 +/// - & __real__ x -> x +static ValueDecl *getPrimaryDecl(Expr *E) { + switch (E->getStmtClass()) { + case Stmt::DeclRefExprClass: + return cast<DeclRefExpr>(E)->getDecl(); + case Stmt::MemberExprClass: + // If this is an arrow operator, the address is an offset from + // the base's value, so the object the base refers to is + // irrelevant. + if (cast<MemberExpr>(E)->isArrow()) + return 0; + // Otherwise, the expression refers to a part of the base + return getPrimaryDecl(cast<MemberExpr>(E)->getBase()); + case Stmt::ArraySubscriptExprClass: { + // FIXME: This code shouldn't be necessary! We should catch the implicit + // promotion of register arrays earlier. + Expr* Base = cast<ArraySubscriptExpr>(E)->getBase(); + if (ImplicitCastExpr* ICE = dyn_cast<ImplicitCastExpr>(Base)) { + if (ICE->getSubExpr()->getType()->isArrayType()) + return getPrimaryDecl(ICE->getSubExpr()); + } + return 0; + } + case Stmt::UnaryOperatorClass: { + UnaryOperator *UO = cast<UnaryOperator>(E); + + switch(UO->getOpcode()) { + case UO_Real: + case UO_Imag: + case UO_Extension: + return getPrimaryDecl(UO->getSubExpr()); + default: + return 0; + } + } + case Stmt::ParenExprClass: + return getPrimaryDecl(cast<ParenExpr>(E)->getSubExpr()); + case Stmt::ImplicitCastExprClass: + // If the result of an implicit cast is an l-value, we care about + // the sub-expression; otherwise, the result here doesn't matter. + return getPrimaryDecl(cast<ImplicitCastExpr>(E)->getSubExpr()); + default: + return 0; + } +} + +/// CheckAddressOfOperand - The operand of & must be either a function +/// designator or an lvalue designating an object. If it is an lvalue, the +/// object cannot be declared with storage class register or be a bit field. +/// Note: The usual conversions are *not* applied to the operand of the & +/// operator (C99 6.3.2.1p[2-4]), and its result is never an lvalue. +/// In C++, the operand might be an overloaded function name, in which case +/// we allow the '&' but retain the overloaded-function type. +static QualType CheckAddressOfOperand(Sema &S, Expr *OrigOp, + SourceLocation OpLoc) { + if (OrigOp->isTypeDependent()) + return S.Context.DependentTy; + if (OrigOp->getType() == S.Context.OverloadTy) + return S.Context.OverloadTy; + if (OrigOp->getType() == S.Context.UnknownAnyTy) + return S.Context.UnknownAnyTy; + if (OrigOp->getType() == S.Context.BoundMemberTy) { + S.Diag(OpLoc, diag::err_invalid_form_pointer_member_function) + << OrigOp->getSourceRange(); + return QualType(); + } + + assert(!OrigOp->getType()->isPlaceholderType()); + + // Make sure to ignore parentheses in subsequent checks + Expr *op = OrigOp->IgnoreParens(); + + if (S.getLangOptions().C99) { + // Implement C99-only parts of addressof rules. + if (UnaryOperator* uOp = dyn_cast<UnaryOperator>(op)) { + if (uOp->getOpcode() == UO_Deref) + // Per C99 6.5.3.2, the address of a deref always returns a valid result + // (assuming the deref expression is valid). + return uOp->getSubExpr()->getType(); + } + // Technically, there should be a check for array subscript + // expressions here, but the result of one is always an lvalue anyway. + } + ValueDecl *dcl = getPrimaryDecl(op); + Expr::LValueClassification lval = op->ClassifyLValue(S.Context); + + if (lval == Expr::LV_ClassTemporary) { + bool sfinae = S.isSFINAEContext(); + S.Diag(OpLoc, sfinae ? diag::err_typecheck_addrof_class_temporary + : diag::ext_typecheck_addrof_class_temporary) + << op->getType() << op->getSourceRange(); + if (sfinae) + return QualType(); + } else if (isa<ObjCSelectorExpr>(op)) { + return S.Context.getPointerType(op->getType()); + } else if (lval == Expr::LV_MemberFunction) { + // If it's an instance method, make a member pointer. + // The expression must have exactly the form &A::foo. + + // If the underlying expression isn't a decl ref, give up. + if (!isa<DeclRefExpr>(op)) { + S.Diag(OpLoc, diag::err_invalid_form_pointer_member_function) + << OrigOp->getSourceRange(); + return QualType(); + } + DeclRefExpr *DRE = cast<DeclRefExpr>(op); + CXXMethodDecl *MD = cast<CXXMethodDecl>(DRE->getDecl()); + + // The id-expression was parenthesized. + if (OrigOp != DRE) { + S.Diag(OpLoc, diag::err_parens_pointer_member_function) + << OrigOp->getSourceRange(); + + // The method was named without a qualifier. + } else if (!DRE->getQualifier()) { + S.Diag(OpLoc, diag::err_unqualified_pointer_member_function) + << op->getSourceRange(); + } + + return S.Context.getMemberPointerType(op->getType(), + S.Context.getTypeDeclType(MD->getParent()).getTypePtr()); + } else if (lval != Expr::LV_Valid && lval != Expr::LV_IncompleteVoidType) { + // C99 6.5.3.2p1 + // The operand must be either an l-value or a function designator + if (!op->getType()->isFunctionType()) { + // FIXME: emit more specific diag... + S.Diag(OpLoc, diag::err_typecheck_invalid_lvalue_addrof) + << op->getSourceRange(); + return QualType(); + } + } else if (op->getObjectKind() == OK_BitField) { // C99 6.5.3.2p1 + // The operand cannot be a bit-field + S.Diag(OpLoc, diag::err_typecheck_address_of) + << "bit-field" << op->getSourceRange(); + return QualType(); + } else if (op->getObjectKind() == OK_VectorComponent) { + // The operand cannot be an element of a vector + S.Diag(OpLoc, diag::err_typecheck_address_of) + << "vector element" << op->getSourceRange(); + return QualType(); + } else if (op->getObjectKind() == OK_ObjCProperty) { + // cannot take address of a property expression. + S.Diag(OpLoc, diag::err_typecheck_address_of) + << "property expression" << op->getSourceRange(); + return QualType(); + } else if (dcl) { // C99 6.5.3.2p1 + // We have an lvalue with a decl. Make sure the decl is not declared + // with the register storage-class specifier. + if (const VarDecl *vd = dyn_cast<VarDecl>(dcl)) { + // in C++ it is not error to take address of a register + // variable (c++03 7.1.1P3) + if (vd->getStorageClass() == SC_Register && + !S.getLangOptions().CPlusPlus) { + S.Diag(OpLoc, diag::err_typecheck_address_of) + << "register variable" << op->getSourceRange(); + return QualType(); + } + } else if (isa<FunctionTemplateDecl>(dcl)) { + return S.Context.OverloadTy; + } else if (isa<FieldDecl>(dcl) || isa<IndirectFieldDecl>(dcl)) { + // Okay: we can take the address of a field. + // Could be a pointer to member, though, if there is an explicit + // scope qualifier for the class. + if (isa<DeclRefExpr>(op) && cast<DeclRefExpr>(op)->getQualifier()) { + DeclContext *Ctx = dcl->getDeclContext(); + if (Ctx && Ctx->isRecord()) { + if (dcl->getType()->isReferenceType()) { + S.Diag(OpLoc, + diag::err_cannot_form_pointer_to_member_of_reference_type) + << dcl->getDeclName() << dcl->getType(); + return QualType(); + } + + while (cast<RecordDecl>(Ctx)->isAnonymousStructOrUnion()) + Ctx = Ctx->getParent(); + return S.Context.getMemberPointerType(op->getType(), + S.Context.getTypeDeclType(cast<RecordDecl>(Ctx)).getTypePtr()); + } + } + } else if (!isa<FunctionDecl>(dcl)) + assert(0 && "Unknown/unexpected decl type"); + } + + if (lval == Expr::LV_IncompleteVoidType) { + // Taking the address of a void variable is technically illegal, but we + // allow it in cases which are otherwise valid. + // Example: "extern void x; void* y = &x;". + S.Diag(OpLoc, diag::ext_typecheck_addrof_void) << op->getSourceRange(); + } + + // If the operand has type "type", the result has type "pointer to type". + if (op->getType()->isObjCObjectType()) + return S.Context.getObjCObjectPointerType(op->getType()); + return S.Context.getPointerType(op->getType()); +} + +/// CheckIndirectionOperand - Type check unary indirection (prefix '*'). +static QualType CheckIndirectionOperand(Sema &S, Expr *Op, ExprValueKind &VK, + SourceLocation OpLoc) { + if (Op->isTypeDependent()) + return S.Context.DependentTy; + + ExprResult ConvResult = S.UsualUnaryConversions(Op); + if (ConvResult.isInvalid()) + return QualType(); + Op = ConvResult.take(); + QualType OpTy = Op->getType(); + QualType Result; + + // Note that per both C89 and C99, indirection is always legal, even if OpTy + // is an incomplete type or void. It would be possible to warn about + // dereferencing a void pointer, but it's completely well-defined, and such a + // warning is unlikely to catch any mistakes. + if (const PointerType *PT = OpTy->getAs<PointerType>()) + Result = PT->getPointeeType(); + else if (const ObjCObjectPointerType *OPT = + OpTy->getAs<ObjCObjectPointerType>()) + Result = OPT->getPointeeType(); + else { + ExprResult PR = S.CheckPlaceholderExpr(Op); + if (PR.isInvalid()) return QualType(); + if (PR.take() != Op) + return CheckIndirectionOperand(S, PR.take(), VK, OpLoc); + } + + if (Result.isNull()) { + S.Diag(OpLoc, diag::err_typecheck_indirection_requires_pointer) + << OpTy << Op->getSourceRange(); + return QualType(); + } + + // Dereferences are usually l-values... + VK = VK_LValue; + + // ...except that certain expressions are never l-values in C. + if (!S.getLangOptions().CPlusPlus && + IsCForbiddenLValueType(S.Context, Result)) + VK = VK_RValue; + + return Result; +} + +static inline BinaryOperatorKind ConvertTokenKindToBinaryOpcode( + tok::TokenKind Kind) { + BinaryOperatorKind Opc; + switch (Kind) { + default: assert(0 && "Unknown binop!"); + case tok::periodstar: Opc = BO_PtrMemD; break; + case tok::arrowstar: Opc = BO_PtrMemI; break; + case tok::star: Opc = BO_Mul; break; + case tok::slash: Opc = BO_Div; break; + case tok::percent: Opc = BO_Rem; break; + case tok::plus: Opc = BO_Add; break; + case tok::minus: Opc = BO_Sub; break; + case tok::lessless: Opc = BO_Shl; break; + case tok::greatergreater: Opc = BO_Shr; break; + case tok::lessequal: Opc = BO_LE; break; + case tok::less: Opc = BO_LT; break; + case tok::greaterequal: Opc = BO_GE; break; + case tok::greater: Opc = BO_GT; break; + case tok::exclaimequal: Opc = BO_NE; break; + case tok::equalequal: Opc = BO_EQ; break; + case tok::amp: Opc = BO_And; break; + case tok::caret: Opc = BO_Xor; break; + case tok::pipe: Opc = BO_Or; break; + case tok::ampamp: Opc = BO_LAnd; break; + case tok::pipepipe: Opc = BO_LOr; break; + case tok::equal: Opc = BO_Assign; break; + case tok::starequal: Opc = BO_MulAssign; break; + case tok::slashequal: Opc = BO_DivAssign; break; + case tok::percentequal: Opc = BO_RemAssign; break; + case tok::plusequal: Opc = BO_AddAssign; break; + case tok::minusequal: Opc = BO_SubAssign; break; + case tok::lesslessequal: Opc = BO_ShlAssign; break; + case tok::greatergreaterequal: Opc = BO_ShrAssign; break; + case tok::ampequal: Opc = BO_AndAssign; break; + case tok::caretequal: Opc = BO_XorAssign; break; + case tok::pipeequal: Opc = BO_OrAssign; break; + case tok::comma: Opc = BO_Comma; break; + } + return Opc; +} + +static inline UnaryOperatorKind ConvertTokenKindToUnaryOpcode( + tok::TokenKind Kind) { + UnaryOperatorKind Opc; + switch (Kind) { + default: assert(0 && "Unknown unary op!"); + case tok::plusplus: Opc = UO_PreInc; break; + case tok::minusminus: Opc = UO_PreDec; break; + case tok::amp: Opc = UO_AddrOf; break; + case tok::star: Opc = UO_Deref; break; + case tok::plus: Opc = UO_Plus; break; + case tok::minus: Opc = UO_Minus; break; + case tok::tilde: Opc = UO_Not; break; + case tok::exclaim: Opc = UO_LNot; break; + case tok::kw___real: Opc = UO_Real; break; + case tok::kw___imag: Opc = UO_Imag; break; + case tok::kw___extension__: Opc = UO_Extension; break; + } + return Opc; +} + +/// DiagnoseSelfAssignment - Emits a warning if a value is assigned to itself. +/// This warning is only emitted for builtin assignment operations. It is also +/// suppressed in the event of macro expansions. +static void DiagnoseSelfAssignment(Sema &S, Expr *lhs, Expr *rhs, + SourceLocation OpLoc) { + if (!S.ActiveTemplateInstantiations.empty()) + return; + if (OpLoc.isInvalid() || OpLoc.isMacroID()) + return; + lhs = lhs->IgnoreParenImpCasts(); + rhs = rhs->IgnoreParenImpCasts(); + const DeclRefExpr *LeftDeclRef = dyn_cast<DeclRefExpr>(lhs); + const DeclRefExpr *RightDeclRef = dyn_cast<DeclRefExpr>(rhs); + if (!LeftDeclRef || !RightDeclRef || + LeftDeclRef->getLocation().isMacroID() || + RightDeclRef->getLocation().isMacroID()) + return; + const ValueDecl *LeftDecl = + cast<ValueDecl>(LeftDeclRef->getDecl()->getCanonicalDecl()); + const ValueDecl *RightDecl = + cast<ValueDecl>(RightDeclRef->getDecl()->getCanonicalDecl()); + if (LeftDecl != RightDecl) + return; + if (LeftDecl->getType().isVolatileQualified()) + return; + if (const ReferenceType *RefTy = LeftDecl->getType()->getAs<ReferenceType>()) + if (RefTy->getPointeeType().isVolatileQualified()) + return; + + S.Diag(OpLoc, diag::warn_self_assignment) + << LeftDeclRef->getType() + << lhs->getSourceRange() << rhs->getSourceRange(); +} + +/// CreateBuiltinBinOp - Creates a new built-in binary operation with +/// operator @p Opc at location @c TokLoc. This routine only supports +/// built-in operations; ActOnBinOp handles overloaded operators. +ExprResult Sema::CreateBuiltinBinOp(SourceLocation OpLoc, + BinaryOperatorKind Opc, + Expr *lhsExpr, Expr *rhsExpr) { + ExprResult lhs = Owned(lhsExpr), rhs = Owned(rhsExpr); + QualType ResultTy; // Result type of the binary operator. + // The following two variables are used for compound assignment operators + QualType CompLHSTy; // Type of LHS after promotions for computation + QualType CompResultTy; // Type of computation result + ExprValueKind VK = VK_RValue; + ExprObjectKind OK = OK_Ordinary; + + // Check if a 'foo<int>' involved in a binary op, identifies a single + // function unambiguously (i.e. an lvalue ala 13.4) + // But since an assignment can trigger target based overload, exclude it in + // our blind search. i.e: + // template<class T> void f(); template<class T, class U> void f(U); + // f<int> == 0; // resolve f<int> blindly + // void (*p)(int); p = f<int>; // resolve f<int> using target + if (Opc != BO_Assign) { + ExprResult resolvedLHS = CheckPlaceholderExpr(lhs.get()); + if (!resolvedLHS.isUsable()) return ExprError(); + lhs = move(resolvedLHS); + + ExprResult resolvedRHS = CheckPlaceholderExpr(rhs.get()); + if (!resolvedRHS.isUsable()) return ExprError(); + rhs = move(resolvedRHS); + } + + switch (Opc) { + case BO_Assign: + ResultTy = CheckAssignmentOperands(lhs.get(), rhs, OpLoc, QualType()); + if (getLangOptions().CPlusPlus && + lhs.get()->getObjectKind() != OK_ObjCProperty) { + VK = lhs.get()->getValueKind(); + OK = lhs.get()->getObjectKind(); + } + if (!ResultTy.isNull()) + DiagnoseSelfAssignment(*this, lhs.get(), rhs.get(), OpLoc); + break; + case BO_PtrMemD: + case BO_PtrMemI: + ResultTy = CheckPointerToMemberOperands(lhs, rhs, VK, OpLoc, + Opc == BO_PtrMemI); + break; + case BO_Mul: + case BO_Div: + ResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, false, + Opc == BO_Div); + break; + case BO_Rem: + ResultTy = CheckRemainderOperands(lhs, rhs, OpLoc); + break; + case BO_Add: + ResultTy = CheckAdditionOperands(lhs, rhs, OpLoc); + break; + case BO_Sub: + ResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc); + break; + case BO_Shl: + case BO_Shr: + ResultTy = CheckShiftOperands(lhs, rhs, OpLoc, Opc); + break; + case BO_LE: + case BO_LT: + case BO_GE: + case BO_GT: + ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, true); + break; + case BO_EQ: + case BO_NE: + ResultTy = CheckCompareOperands(lhs, rhs, OpLoc, Opc, false); + break; + case BO_And: + case BO_Xor: + case BO_Or: + ResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc); + break; + case BO_LAnd: + case BO_LOr: + ResultTy = CheckLogicalOperands(lhs, rhs, OpLoc, Opc); + break; + case BO_MulAssign: + case BO_DivAssign: + CompResultTy = CheckMultiplyDivideOperands(lhs, rhs, OpLoc, true, + Opc == BO_DivAssign); + CompLHSTy = CompResultTy; + if (!CompResultTy.isNull() && !lhs.isInvalid() && !rhs.isInvalid()) + ResultTy = CheckAssignmentOperands(lhs.get(), rhs, OpLoc, CompResultTy); + break; + case BO_RemAssign: + CompResultTy = CheckRemainderOperands(lhs, rhs, OpLoc, true); + CompLHSTy = CompResultTy; + if (!CompResultTy.isNull() && !lhs.isInvalid() && !rhs.isInvalid()) + ResultTy = CheckAssignmentOperands(lhs.get(), rhs, OpLoc, CompResultTy); + break; + case BO_AddAssign: + CompResultTy = CheckAdditionOperands(lhs, rhs, OpLoc, &CompLHSTy); + if (!CompResultTy.isNull() && !lhs.isInvalid() && !rhs.isInvalid()) + ResultTy = CheckAssignmentOperands(lhs.get(), rhs, OpLoc, CompResultTy); + break; + case BO_SubAssign: + CompResultTy = CheckSubtractionOperands(lhs, rhs, OpLoc, &CompLHSTy); + if (!CompResultTy.isNull() && !lhs.isInvalid() && !rhs.isInvalid()) + ResultTy = CheckAssignmentOperands(lhs.get(), rhs, OpLoc, CompResultTy); + break; + case BO_ShlAssign: + case BO_ShrAssign: + CompResultTy = CheckShiftOperands(lhs, rhs, OpLoc, Opc, true); + CompLHSTy = CompResultTy; + if (!CompResultTy.isNull() && !lhs.isInvalid() && !rhs.isInvalid()) + ResultTy = CheckAssignmentOperands(lhs.get(), rhs, OpLoc, CompResultTy); + break; + case BO_AndAssign: + case BO_XorAssign: + case BO_OrAssign: + CompResultTy = CheckBitwiseOperands(lhs, rhs, OpLoc, true); + CompLHSTy = CompResultTy; + if (!CompResultTy.isNull() && !lhs.isInvalid() && !rhs.isInvalid()) + ResultTy = CheckAssignmentOperands(lhs.get(), rhs, OpLoc, CompResultTy); + break; + case BO_Comma: + ResultTy = CheckCommaOperands(*this, lhs, rhs, OpLoc); + if (getLangOptions().CPlusPlus && !rhs.isInvalid()) { + VK = rhs.get()->getValueKind(); + OK = rhs.get()->getObjectKind(); + } + break; + } + if (ResultTy.isNull() || lhs.isInvalid() || rhs.isInvalid()) + return ExprError(); + if (CompResultTy.isNull()) + return Owned(new (Context) BinaryOperator(lhs.take(), rhs.take(), Opc, + ResultTy, VK, OK, OpLoc)); + if (getLangOptions().CPlusPlus && lhs.get()->getObjectKind() != OK_ObjCProperty) { + VK = VK_LValue; + OK = lhs.get()->getObjectKind(); + } + return Owned(new (Context) CompoundAssignOperator(lhs.take(), rhs.take(), Opc, + ResultTy, VK, OK, CompLHSTy, + CompResultTy, OpLoc)); +} + +/// SuggestParentheses - Emit a diagnostic together with a fixit hint that wraps +/// ParenRange in parentheses. +static void SuggestParentheses(Sema &Self, SourceLocation Loc, + const PartialDiagnostic &PD, + const PartialDiagnostic &FirstNote, + SourceRange FirstParenRange, + const PartialDiagnostic &SecondNote, + SourceRange SecondParenRange) { + Self.Diag(Loc, PD); + + if (!FirstNote.getDiagID()) + return; + + SourceLocation EndLoc = Self.PP.getLocForEndOfToken(FirstParenRange.getEnd()); + if (!FirstParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { + // We can't display the parentheses, so just return. + return; + } + + Self.Diag(Loc, FirstNote) + << FixItHint::CreateInsertion(FirstParenRange.getBegin(), "(") + << FixItHint::CreateInsertion(EndLoc, ")"); + + if (!SecondNote.getDiagID()) + return; + + EndLoc = Self.PP.getLocForEndOfToken(SecondParenRange.getEnd()); + if (!SecondParenRange.getEnd().isFileID() || EndLoc.isInvalid()) { + // We can't display the parentheses, so just dig the + // warning/error and return. + Self.Diag(Loc, SecondNote); + return; + } + + Self.Diag(Loc, SecondNote) + << FixItHint::CreateInsertion(SecondParenRange.getBegin(), "(") + << FixItHint::CreateInsertion(EndLoc, ")"); +} + +/// DiagnoseBitwisePrecedence - Emit a warning when bitwise and comparison +/// operators are mixed in a way that suggests that the programmer forgot that +/// comparison operators have higher precedence. The most typical example of +/// such code is "flags & 0x0020 != 0", which is equivalent to "flags & 1". +static void DiagnoseBitwisePrecedence(Sema &Self, BinaryOperatorKind Opc, + SourceLocation OpLoc,Expr *lhs,Expr *rhs){ + typedef BinaryOperator BinOp; + BinOp::Opcode lhsopc = static_cast<BinOp::Opcode>(-1), + rhsopc = static_cast<BinOp::Opcode>(-1); + if (BinOp *BO = dyn_cast<BinOp>(lhs)) + lhsopc = BO->getOpcode(); + if (BinOp *BO = dyn_cast<BinOp>(rhs)) + rhsopc = BO->getOpcode(); + + // Subs are not binary operators. + if (lhsopc == -1 && rhsopc == -1) + return; + + // Bitwise operations are sometimes used as eager logical ops. + // Don't diagnose this. + if ((BinOp::isComparisonOp(lhsopc) || BinOp::isBitwiseOp(lhsopc)) && + (BinOp::isComparisonOp(rhsopc) || BinOp::isBitwiseOp(rhsopc))) + return; + + if (BinOp::isComparisonOp(lhsopc)) + SuggestParentheses(Self, OpLoc, + Self.PDiag(diag::warn_precedence_bitwise_rel) + << SourceRange(lhs->getLocStart(), OpLoc) + << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(lhsopc), + Self.PDiag(diag::note_precedence_bitwise_silence) + << BinOp::getOpcodeStr(lhsopc), + lhs->getSourceRange(), + Self.PDiag(diag::note_precedence_bitwise_first) + << BinOp::getOpcodeStr(Opc), + SourceRange(cast<BinOp>(lhs)->getRHS()->getLocStart(), rhs->getLocEnd())); + else if (BinOp::isComparisonOp(rhsopc)) + SuggestParentheses(Self, OpLoc, + Self.PDiag(diag::warn_precedence_bitwise_rel) + << SourceRange(OpLoc, rhs->getLocEnd()) + << BinOp::getOpcodeStr(Opc) << BinOp::getOpcodeStr(rhsopc), + Self.PDiag(diag::note_precedence_bitwise_silence) + << BinOp::getOpcodeStr(rhsopc), + rhs->getSourceRange(), + Self.PDiag(diag::note_precedence_bitwise_first) + << BinOp::getOpcodeStr(Opc), + SourceRange(lhs->getLocEnd(), cast<BinOp>(rhs)->getLHS()->getLocStart())); +} + +/// \brief It accepts a '&&' expr that is inside a '||' one. +/// Emit a diagnostic together with a fixit hint that wraps the '&&' expression +/// in parentheses. +static void +EmitDiagnosticForLogicalAndInLogicalOr(Sema &Self, SourceLocation OpLoc, + BinaryOperator *Bop) { + assert(Bop->getOpcode() == BO_LAnd); + SuggestParentheses(Self, Bop->getOperatorLoc(), + Self.PDiag(diag::warn_logical_and_in_logical_or) + << Bop->getSourceRange() << OpLoc, + Self.PDiag(diag::note_logical_and_in_logical_or_silence), + Bop->getSourceRange(), + Self.PDiag(0), SourceRange()); +} + +/// \brief Returns true if the given expression can be evaluated as a constant +/// 'true'. +static bool EvaluatesAsTrue(Sema &S, Expr *E) { + bool Res; + return E->EvaluateAsBooleanCondition(Res, S.getASTContext()) && Res; +} + +/// \brief Returns true if the given expression can be evaluated as a constant +/// 'false'. +static bool EvaluatesAsFalse(Sema &S, Expr *E) { + bool Res; + return E->EvaluateAsBooleanCondition(Res, S.getASTContext()) && !Res; +} + +/// \brief Look for '&&' in the left hand of a '||' expr. +static void DiagnoseLogicalAndInLogicalOrLHS(Sema &S, SourceLocation OpLoc, + Expr *OrLHS, Expr *OrRHS) { + if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(OrLHS)) { + if (Bop->getOpcode() == BO_LAnd) { + // If it's "a && b || 0" don't warn since the precedence doesn't matter. + if (EvaluatesAsFalse(S, OrRHS)) + return; + // If it's "1 && a || b" don't warn since the precedence doesn't matter. + if (!EvaluatesAsTrue(S, Bop->getLHS())) + return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop); + } else if (Bop->getOpcode() == BO_LOr) { + if (BinaryOperator *RBop = dyn_cast<BinaryOperator>(Bop->getRHS())) { + // If it's "a || b && 1 || c" we didn't warn earlier for + // "a || b && 1", but warn now. + if (RBop->getOpcode() == BO_LAnd && EvaluatesAsTrue(S, RBop->getRHS())) + return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, RBop); + } + } + } +} + +/// \brief Look for '&&' in the right hand of a '||' expr. +static void DiagnoseLogicalAndInLogicalOrRHS(Sema &S, SourceLocation OpLoc, + Expr *OrLHS, Expr *OrRHS) { + if (BinaryOperator *Bop = dyn_cast<BinaryOperator>(OrRHS)) { + if (Bop->getOpcode() == BO_LAnd) { + // If it's "0 || a && b" don't warn since the precedence doesn't matter. + if (EvaluatesAsFalse(S, OrLHS)) + return; + // If it's "a || b && 1" don't warn since the precedence doesn't matter. + if (!EvaluatesAsTrue(S, Bop->getRHS())) + return EmitDiagnosticForLogicalAndInLogicalOr(S, OpLoc, Bop); + } + } +} + +/// DiagnoseBinOpPrecedence - Emit warnings for expressions with tricky +/// precedence. +static void DiagnoseBinOpPrecedence(Sema &Self, BinaryOperatorKind Opc, + SourceLocation OpLoc, Expr *lhs, Expr *rhs){ + // Diagnose "arg1 'bitwise' arg2 'eq' arg3". + if (BinaryOperator::isBitwiseOp(Opc)) + return DiagnoseBitwisePrecedence(Self, Opc, OpLoc, lhs, rhs); + + // Warn about arg1 || arg2 && arg3, as GCC 4.3+ does. + // We don't warn for 'assert(a || b && "bad")' since this is safe. + if (Opc == BO_LOr && !OpLoc.isMacroID()/* Don't warn in macros. */) { + DiagnoseLogicalAndInLogicalOrLHS(Self, OpLoc, lhs, rhs); + DiagnoseLogicalAndInLogicalOrRHS(Self, OpLoc, lhs, rhs); + } +} + +// Binary Operators. 'Tok' is the token for the operator. +ExprResult Sema::ActOnBinOp(Scope *S, SourceLocation TokLoc, + tok::TokenKind Kind, + Expr *lhs, Expr *rhs) { + BinaryOperatorKind Opc = ConvertTokenKindToBinaryOpcode(Kind); + assert((lhs != 0) && "ActOnBinOp(): missing left expression"); + assert((rhs != 0) && "ActOnBinOp(): missing right expression"); + + // Emit warnings for tricky precedence issues, e.g. "bitfield & 0x4 == 0" + DiagnoseBinOpPrecedence(*this, Opc, TokLoc, lhs, rhs); + + return BuildBinOp(S, TokLoc, Opc, lhs, rhs); +} + +ExprResult Sema::BuildBinOp(Scope *S, SourceLocation OpLoc, + BinaryOperatorKind Opc, + Expr *lhs, Expr *rhs) { + if (getLangOptions().CPlusPlus) { + bool UseBuiltinOperator; + + if (lhs->isTypeDependent() || rhs->isTypeDependent()) { + UseBuiltinOperator = false; + } else if (Opc == BO_Assign && lhs->getObjectKind() == OK_ObjCProperty) { + UseBuiltinOperator = true; + } else { + UseBuiltinOperator = !lhs->getType()->isOverloadableType() && + !rhs->getType()->isOverloadableType(); + } + + if (!UseBuiltinOperator) { + // Find all of the overloaded operators visible from this + // point. We perform both an operator-name lookup from the local + // scope and an argument-dependent lookup based on the types of + // the arguments. + UnresolvedSet<16> Functions; + OverloadedOperatorKind OverOp + = BinaryOperator::getOverloadedOperator(Opc); + if (S && OverOp != OO_None) + LookupOverloadedOperatorName(OverOp, S, lhs->getType(), rhs->getType(), + Functions); + + // Build the (potentially-overloaded, potentially-dependent) + // binary operation. + return CreateOverloadedBinOp(OpLoc, Opc, Functions, lhs, rhs); + } + } + + // Build a built-in binary operation. + return CreateBuiltinBinOp(OpLoc, Opc, lhs, rhs); +} + +ExprResult Sema::CreateBuiltinUnaryOp(SourceLocation OpLoc, + UnaryOperatorKind Opc, + Expr *InputExpr) { + ExprResult Input = Owned(InputExpr); + ExprValueKind VK = VK_RValue; + ExprObjectKind OK = OK_Ordinary; + QualType resultType; + switch (Opc) { + case UO_PreInc: + case UO_PreDec: + case UO_PostInc: + case UO_PostDec: + resultType = CheckIncrementDecrementOperand(*this, Input.get(), VK, OpLoc, + Opc == UO_PreInc || + Opc == UO_PostInc, + Opc == UO_PreInc || + Opc == UO_PreDec); + break; + case UO_AddrOf: + resultType = CheckAddressOfOperand(*this, Input.get(), OpLoc); + break; + case UO_Deref: { + ExprResult resolved = CheckPlaceholderExpr(Input.get()); + if (!resolved.isUsable()) return ExprError(); + Input = move(resolved); + Input = DefaultFunctionArrayLvalueConversion(Input.take()); + resultType = CheckIndirectionOperand(*this, Input.get(), VK, OpLoc); + break; + } + case UO_Plus: + case UO_Minus: + Input = UsualUnaryConversions(Input.take()); + if (Input.isInvalid()) return ExprError(); + resultType = Input.get()->getType(); + if (resultType->isDependentType()) + break; + if (resultType->isArithmeticType() || // C99 6.5.3.3p1 + resultType->isVectorType()) + break; + else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6-7 + resultType->isEnumeralType()) + break; + else if (getLangOptions().CPlusPlus && // C++ [expr.unary.op]p6 + Opc == UO_Plus && + resultType->isPointerType()) + break; + else if (resultType->isPlaceholderType()) { + Input = CheckPlaceholderExpr(Input.take()); + if (Input.isInvalid()) return ExprError(); + return CreateBuiltinUnaryOp(OpLoc, Opc, Input.take()); + } + + return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) + << resultType << Input.get()->getSourceRange()); + + case UO_Not: // bitwise complement + Input = UsualUnaryConversions(Input.take()); + if (Input.isInvalid()) return ExprError(); + resultType = Input.get()->getType(); + if (resultType->isDependentType()) + break; + // C99 6.5.3.3p1. We allow complex int and float as a GCC extension. + if (resultType->isComplexType() || resultType->isComplexIntegerType()) + // C99 does not support '~' for complex conjugation. + Diag(OpLoc, diag::ext_integer_complement_complex) + << resultType << Input.get()->getSourceRange(); + else if (resultType->hasIntegerRepresentation()) + break; + else if (resultType->isPlaceholderType()) { + Input = CheckPlaceholderExpr(Input.take()); + if (Input.isInvalid()) return ExprError(); + return CreateBuiltinUnaryOp(OpLoc, Opc, Input.take()); + } else { + return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) + << resultType << Input.get()->getSourceRange()); + } + break; + + case UO_LNot: // logical negation + // Unlike +/-/~, integer promotions aren't done here (C99 6.5.3.3p5). + Input = DefaultFunctionArrayLvalueConversion(Input.take()); + if (Input.isInvalid()) return ExprError(); + resultType = Input.get()->getType(); + if (resultType->isDependentType()) + break; + if (resultType->isScalarType()) { + // C99 6.5.3.3p1: ok, fallthrough; + if (Context.getLangOptions().CPlusPlus) { + // C++03 [expr.unary.op]p8, C++0x [expr.unary.op]p9: + // operand contextually converted to bool. + Input = ImpCastExprToType(Input.take(), Context.BoolTy, + ScalarTypeToBooleanCastKind(resultType)); + } + } else if (resultType->isPlaceholderType()) { + Input = CheckPlaceholderExpr(Input.take()); + if (Input.isInvalid()) return ExprError(); + return CreateBuiltinUnaryOp(OpLoc, Opc, Input.take()); + } else { + return ExprError(Diag(OpLoc, diag::err_typecheck_unary_expr) + << resultType << Input.get()->getSourceRange()); + } + + // LNot always has type int. C99 6.5.3.3p5. + // In C++, it's bool. C++ 5.3.1p8 + resultType = Context.getLogicalOperationType(); + break; + case UO_Real: + case UO_Imag: + resultType = CheckRealImagOperand(*this, Input, OpLoc, Opc == UO_Real); + // _Real and _Imag map ordinary l-values into ordinary l-values. + if (Input.isInvalid()) return ExprError(); + if (Input.get()->getValueKind() != VK_RValue && + Input.get()->getObjectKind() == OK_Ordinary) + VK = Input.get()->getValueKind(); + break; + case UO_Extension: + resultType = Input.get()->getType(); + VK = Input.get()->getValueKind(); + OK = Input.get()->getObjectKind(); + break; + } + if (resultType.isNull() || Input.isInvalid()) + return ExprError(); + + return Owned(new (Context) UnaryOperator(Input.take(), Opc, resultType, + VK, OK, OpLoc)); +} + +ExprResult Sema::BuildUnaryOp(Scope *S, SourceLocation OpLoc, + UnaryOperatorKind Opc, + Expr *Input) { + if (getLangOptions().CPlusPlus && Input->getType()->isOverloadableType() && + UnaryOperator::getOverloadedOperator(Opc) != OO_None) { + // Find all of the overloaded operators visible from this + // point. We perform both an operator-name lookup from the local + // scope and an argument-dependent lookup based on the types of + // the arguments. + UnresolvedSet<16> Functions; + OverloadedOperatorKind OverOp = UnaryOperator::getOverloadedOperator(Opc); + if (S && OverOp != OO_None) + LookupOverloadedOperatorName(OverOp, S, Input->getType(), QualType(), + Functions); + + return CreateOverloadedUnaryOp(OpLoc, Opc, Functions, Input); + } + + return CreateBuiltinUnaryOp(OpLoc, Opc, Input); +} + +// Unary Operators. 'Tok' is the token for the operator. +ExprResult Sema::ActOnUnaryOp(Scope *S, SourceLocation OpLoc, + tok::TokenKind Op, Expr *Input) { + return BuildUnaryOp(S, OpLoc, ConvertTokenKindToUnaryOpcode(Op), Input); +} + +/// ActOnAddrLabel - Parse the GNU address of label extension: "&&foo". +ExprResult Sema::ActOnAddrLabel(SourceLocation OpLoc, SourceLocation LabLoc, + LabelDecl *TheDecl) { + TheDecl->setUsed(); + // Create the AST node. The address of a label always has type 'void*'. + return Owned(new (Context) AddrLabelExpr(OpLoc, LabLoc, TheDecl, + Context.getPointerType(Context.VoidTy))); +} + +ExprResult +Sema::ActOnStmtExpr(SourceLocation LPLoc, Stmt *SubStmt, + SourceLocation RPLoc) { // "({..})" + assert(SubStmt && isa<CompoundStmt>(SubStmt) && "Invalid action invocation!"); + CompoundStmt *Compound = cast<CompoundStmt>(SubStmt); + + bool isFileScope + = (getCurFunctionOrMethodDecl() == 0) && (getCurBlock() == 0); + if (isFileScope) + return ExprError(Diag(LPLoc, diag::err_stmtexpr_file_scope)); + + // FIXME: there are a variety of strange constraints to enforce here, for + // example, it is not possible to goto into a stmt expression apparently. + // More semantic analysis is needed. + + // If there are sub stmts in the compound stmt, take the type of the last one + // as the type of the stmtexpr. + QualType Ty = Context.VoidTy; + bool StmtExprMayBindToTemp = false; + if (!Compound->body_empty()) { + Stmt *LastStmt = Compound->body_back(); + LabelStmt *LastLabelStmt = 0; + // If LastStmt is a label, skip down through into the body. + while (LabelStmt *Label = dyn_cast<LabelStmt>(LastStmt)) { + LastLabelStmt = Label; + LastStmt = Label->getSubStmt(); + } + if (Expr *LastE = dyn_cast<Expr>(LastStmt)) { + // Do function/array conversion on the last expression, but not + // lvalue-to-rvalue. However, initialize an unqualified type. + ExprResult LastExpr = DefaultFunctionArrayConversion(LastE); + if (LastExpr.isInvalid()) + return ExprError(); + Ty = LastExpr.get()->getType().getUnqualifiedType(); + + if (!Ty->isDependentType() && !LastExpr.get()->isTypeDependent()) { + LastExpr = PerformCopyInitialization( + InitializedEntity::InitializeResult(LPLoc, + Ty, + false), + SourceLocation(), + LastExpr); + if (LastExpr.isInvalid()) + return ExprError(); + if (LastExpr.get() != 0) { + if (!LastLabelStmt) + Compound->setLastStmt(LastExpr.take()); + else + LastLabelStmt->setSubStmt(LastExpr.take()); + StmtExprMayBindToTemp = true; + } + } + } + } + + // FIXME: Check that expression type is complete/non-abstract; statement + // expressions are not lvalues. + Expr *ResStmtExpr = new (Context) StmtExpr(Compound, Ty, LPLoc, RPLoc); + if (StmtExprMayBindToTemp) + return MaybeBindToTemporary(ResStmtExpr); + return Owned(ResStmtExpr); +} + +ExprResult Sema::BuildBuiltinOffsetOf(SourceLocation BuiltinLoc, + TypeSourceInfo *TInfo, + OffsetOfComponent *CompPtr, + unsigned NumComponents, + SourceLocation RParenLoc) { + QualType ArgTy = TInfo->getType(); + bool Dependent = ArgTy->isDependentType(); + SourceRange TypeRange = TInfo->getTypeLoc().getLocalSourceRange(); + + // We must have at least one component that refers to the type, and the first + // one is known to be a field designator. Verify that the ArgTy represents + // a struct/union/class. + if (!Dependent && !ArgTy->isRecordType()) + return ExprError(Diag(BuiltinLoc, diag::err_offsetof_record_type) + << ArgTy << TypeRange); + + // Type must be complete per C99 7.17p3 because a declaring a variable + // with an incomplete type would be ill-formed. + if (!Dependent + && RequireCompleteType(BuiltinLoc, ArgTy, + PDiag(diag::err_offsetof_incomplete_type) + << TypeRange)) + return ExprError(); + + // offsetof with non-identifier designators (e.g. "offsetof(x, a.b[c])") are a + // GCC extension, diagnose them. + // FIXME: This diagnostic isn't actually visible because the location is in + // a system header! + if (NumComponents != 1) + Diag(BuiltinLoc, diag::ext_offsetof_extended_field_designator) + << SourceRange(CompPtr[1].LocStart, CompPtr[NumComponents-1].LocEnd); + + bool DidWarnAboutNonPOD = false; + QualType CurrentType = ArgTy; + typedef OffsetOfExpr::OffsetOfNode OffsetOfNode; + llvm::SmallVector<OffsetOfNode, 4> Comps; + llvm::SmallVector<Expr*, 4> Exprs; + for (unsigned i = 0; i != NumComponents; ++i) { + const OffsetOfComponent &OC = CompPtr[i]; + if (OC.isBrackets) { + // Offset of an array sub-field. TODO: Should we allow vector elements? + if (!CurrentType->isDependentType()) { + const ArrayType *AT = Context.getAsArrayType(CurrentType); + if(!AT) + return ExprError(Diag(OC.LocEnd, diag::err_offsetof_array_type) + << CurrentType); + CurrentType = AT->getElementType(); + } else + CurrentType = Context.DependentTy; + + // The expression must be an integral expression. + // FIXME: An integral constant expression? + Expr *Idx = static_cast<Expr*>(OC.U.E); + if (!Idx->isTypeDependent() && !Idx->isValueDependent() && + !Idx->getType()->isIntegerType()) + return ExprError(Diag(Idx->getLocStart(), + diag::err_typecheck_subscript_not_integer) + << Idx->getSourceRange()); + + // Record this array index. + Comps.push_back(OffsetOfNode(OC.LocStart, Exprs.size(), OC.LocEnd)); + Exprs.push_back(Idx); + continue; + } + + // Offset of a field. + if (CurrentType->isDependentType()) { + // We have the offset of a field, but we can't look into the dependent + // type. Just record the identifier of the field. + Comps.push_back(OffsetOfNode(OC.LocStart, OC.U.IdentInfo, OC.LocEnd)); + CurrentType = Context.DependentTy; + continue; + } + + // We need to have a complete type to look into. + if (RequireCompleteType(OC.LocStart, CurrentType, + diag::err_offsetof_incomplete_type)) + return ExprError(); + + // Look for the designated field. + const RecordType *RC = CurrentType->getAs<RecordType>(); + if (!RC) + return ExprError(Diag(OC.LocEnd, diag::err_offsetof_record_type) + << CurrentType); + RecordDecl *RD = RC->getDecl(); + + // C++ [lib.support.types]p5: + // The macro offsetof accepts a restricted set of type arguments in this + // International Standard. type shall be a POD structure or a POD union + // (clause 9). + if (CXXRecordDecl *CRD = dyn_cast<CXXRecordDecl>(RD)) { + if (!CRD->isPOD() && !DidWarnAboutNonPOD && + DiagRuntimeBehavior(BuiltinLoc, 0, + PDiag(diag::warn_offsetof_non_pod_type) + << SourceRange(CompPtr[0].LocStart, OC.LocEnd) + << CurrentType)) + DidWarnAboutNonPOD = true; + } + + // Look for the field. + LookupResult R(*this, OC.U.IdentInfo, OC.LocStart, LookupMemberName); + LookupQualifiedName(R, RD); + FieldDecl *MemberDecl = R.getAsSingle<FieldDecl>(); + IndirectFieldDecl *IndirectMemberDecl = 0; + if (!MemberDecl) { + if ((IndirectMemberDecl = R.getAsSingle<IndirectFieldDecl>())) + MemberDecl = IndirectMemberDecl->getAnonField(); + } + + if (!MemberDecl) + return ExprError(Diag(BuiltinLoc, diag::err_no_member) + << OC.U.IdentInfo << RD << SourceRange(OC.LocStart, + OC.LocEnd)); + + // C99 7.17p3: + // (If the specified member is a bit-field, the behavior is undefined.) + // + // We diagnose this as an error. + if (MemberDecl->getBitWidth()) { + Diag(OC.LocEnd, diag::err_offsetof_bitfield) + << MemberDecl->getDeclName() + << SourceRange(BuiltinLoc, RParenLoc); + Diag(MemberDecl->getLocation(), diag::note_bitfield_decl); + return ExprError(); + } + + RecordDecl *Parent = MemberDecl->getParent(); + if (IndirectMemberDecl) + Parent = cast<RecordDecl>(IndirectMemberDecl->getDeclContext()); + + // If the member was found in a base class, introduce OffsetOfNodes for + // the base class indirections. + CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true, + /*DetectVirtual=*/false); + if (IsDerivedFrom(CurrentType, Context.getTypeDeclType(Parent), Paths)) { + CXXBasePath &Path = Paths.front(); + for (CXXBasePath::iterator B = Path.begin(), BEnd = Path.end(); + B != BEnd; ++B) + Comps.push_back(OffsetOfNode(B->Base)); + } + + if (IndirectMemberDecl) { + for (IndirectFieldDecl::chain_iterator FI = + IndirectMemberDecl->chain_begin(), + FEnd = IndirectMemberDecl->chain_end(); FI != FEnd; FI++) { + assert(isa<FieldDecl>(*FI)); + Comps.push_back(OffsetOfNode(OC.LocStart, + cast<FieldDecl>(*FI), OC.LocEnd)); + } + } else + Comps.push_back(OffsetOfNode(OC.LocStart, MemberDecl, OC.LocEnd)); + + CurrentType = MemberDecl->getType().getNonReferenceType(); + } + + return Owned(OffsetOfExpr::Create(Context, Context.getSizeType(), BuiltinLoc, + TInfo, Comps.data(), Comps.size(), + Exprs.data(), Exprs.size(), RParenLoc)); +} + +ExprResult Sema::ActOnBuiltinOffsetOf(Scope *S, + SourceLocation BuiltinLoc, + SourceLocation TypeLoc, + ParsedType argty, + OffsetOfComponent *CompPtr, + unsigned NumComponents, + SourceLocation RPLoc) { + + TypeSourceInfo *ArgTInfo; + QualType ArgTy = GetTypeFromParser(argty, &ArgTInfo); + if (ArgTy.isNull()) + return ExprError(); + + if (!ArgTInfo) + ArgTInfo = Context.getTrivialTypeSourceInfo(ArgTy, TypeLoc); + + return BuildBuiltinOffsetOf(BuiltinLoc, ArgTInfo, CompPtr, NumComponents, + RPLoc); +} + + +ExprResult Sema::ActOnChooseExpr(SourceLocation BuiltinLoc, + Expr *CondExpr, + Expr *LHSExpr, Expr *RHSExpr, + SourceLocation RPLoc) { + assert((CondExpr && LHSExpr && RHSExpr) && "Missing type argument(s)"); + + ExprValueKind VK = VK_RValue; + ExprObjectKind OK = OK_Ordinary; + QualType resType; + bool ValueDependent = false; + if (CondExpr->isTypeDependent() || CondExpr->isValueDependent()) { + resType = Context.DependentTy; + ValueDependent = true; + } else { + // The conditional expression is required to be a constant expression. + llvm::APSInt condEval(32); + SourceLocation ExpLoc; + if (!CondExpr->isIntegerConstantExpr(condEval, Context, &ExpLoc)) + return ExprError(Diag(ExpLoc, + diag::err_typecheck_choose_expr_requires_constant) + << CondExpr->getSourceRange()); + + // If the condition is > zero, then the AST type is the same as the LSHExpr. + Expr *ActiveExpr = condEval.getZExtValue() ? LHSExpr : RHSExpr; + + resType = ActiveExpr->getType(); + ValueDependent = ActiveExpr->isValueDependent(); + VK = ActiveExpr->getValueKind(); + OK = ActiveExpr->getObjectKind(); + } + + return Owned(new (Context) ChooseExpr(BuiltinLoc, CondExpr, LHSExpr, RHSExpr, + resType, VK, OK, RPLoc, + resType->isDependentType(), + ValueDependent)); +} + +//===----------------------------------------------------------------------===// +// Clang Extensions. +//===----------------------------------------------------------------------===// + +/// ActOnBlockStart - This callback is invoked when a block literal is started. +void Sema::ActOnBlockStart(SourceLocation CaretLoc, Scope *BlockScope) { + BlockDecl *Block = BlockDecl::Create(Context, CurContext, CaretLoc); + PushBlockScope(BlockScope, Block); + CurContext->addDecl(Block); + if (BlockScope) + PushDeclContext(BlockScope, Block); + else + CurContext = Block; +} + +void Sema::ActOnBlockArguments(Declarator &ParamInfo, Scope *CurScope) { + assert(ParamInfo.getIdentifier()==0 && "block-id should have no identifier!"); + assert(ParamInfo.getContext() == Declarator::BlockLiteralContext); + BlockScopeInfo *CurBlock = getCurBlock(); + + TypeSourceInfo *Sig = GetTypeForDeclarator(ParamInfo, CurScope); + QualType T = Sig->getType(); + + // GetTypeForDeclarator always produces a function type for a block + // literal signature. Furthermore, it is always a FunctionProtoType + // unless the function was written with a typedef. + assert(T->isFunctionType() && + "GetTypeForDeclarator made a non-function block signature"); + + // Look for an explicit signature in that function type. + FunctionProtoTypeLoc ExplicitSignature; + + TypeLoc tmp = Sig->getTypeLoc().IgnoreParens(); + if (isa<FunctionProtoTypeLoc>(tmp)) { + ExplicitSignature = cast<FunctionProtoTypeLoc>(tmp); + + // Check whether that explicit signature was synthesized by + // GetTypeForDeclarator. If so, don't save that as part of the + // written signature. + if (ExplicitSignature.getLocalRangeBegin() == + ExplicitSignature.getLocalRangeEnd()) { + // This would be much cheaper if we stored TypeLocs instead of + // TypeSourceInfos. + TypeLoc Result = ExplicitSignature.getResultLoc(); + unsigned Size = Result.getFullDataSize(); + Sig = Context.CreateTypeSourceInfo(Result.getType(), Size); + Sig->getTypeLoc().initializeFullCopy(Result, Size); + + ExplicitSignature = FunctionProtoTypeLoc(); + } + } + + CurBlock->TheDecl->setSignatureAsWritten(Sig); + CurBlock->FunctionType = T; + + const FunctionType *Fn = T->getAs<FunctionType>(); + QualType RetTy = Fn->getResultType(); + bool isVariadic = + (isa<FunctionProtoType>(Fn) && cast<FunctionProtoType>(Fn)->isVariadic()); + + CurBlock->TheDecl->setIsVariadic(isVariadic); + + // Don't allow returning a objc interface by value. + if (RetTy->isObjCObjectType()) { + Diag(ParamInfo.getSourceRange().getBegin(), + diag::err_object_cannot_be_passed_returned_by_value) << 0 << RetTy; + return; + } + + // Context.DependentTy is used as a placeholder for a missing block + // return type. TODO: what should we do with declarators like: + // ^ * { ... } + // If the answer is "apply template argument deduction".... + if (RetTy != Context.DependentTy) + CurBlock->ReturnType = RetTy; + + // Push block parameters from the declarator if we had them. + llvm::SmallVector<ParmVarDecl*, 8> Params; + if (ExplicitSignature) { + for (unsigned I = 0, E = ExplicitSignature.getNumArgs(); I != E; ++I) { + ParmVarDecl *Param = ExplicitSignature.getArg(I); + if (Param->getIdentifier() == 0 && + !Param->isImplicit() && + !Param->isInvalidDecl() && + !getLangOptions().CPlusPlus) + Diag(Param->getLocation(), diag::err_parameter_name_omitted); + Params.push_back(Param); + } + + // Fake up parameter variables if we have a typedef, like + // ^ fntype { ... } + } else if (const FunctionProtoType *Fn = T->getAs<FunctionProtoType>()) { + for (FunctionProtoType::arg_type_iterator + I = Fn->arg_type_begin(), E = Fn->arg_type_end(); I != E; ++I) { + ParmVarDecl *Param = + BuildParmVarDeclForTypedef(CurBlock->TheDecl, + ParamInfo.getSourceRange().getBegin(), + *I); + Params.push_back(Param); + } + } + + // Set the parameters on the block decl. + if (!Params.empty()) { + CurBlock->TheDecl->setParams(Params.data(), Params.size()); + CheckParmsForFunctionDef(CurBlock->TheDecl->param_begin(), + CurBlock->TheDecl->param_end(), + /*CheckParameterNames=*/false); + } + + // Finally we can process decl attributes. + ProcessDeclAttributes(CurScope, CurBlock->TheDecl, ParamInfo); + + if (!isVariadic && CurBlock->TheDecl->getAttr<SentinelAttr>()) { + Diag(ParamInfo.getAttributes()->getLoc(), + diag::warn_attribute_sentinel_not_variadic) << 1; + // FIXME: remove the attribute. + } + + // Put the parameter variables in scope. We can bail out immediately + // if we don't have any. + if (Params.empty()) + return; + + for (BlockDecl::param_iterator AI = CurBlock->TheDecl->param_begin(), + E = CurBlock->TheDecl->param_end(); AI != E; ++AI) { + (*AI)->setOwningFunction(CurBlock->TheDecl); + + // If this has an identifier, add it to the scope stack. + if ((*AI)->getIdentifier()) { + CheckShadow(CurBlock->TheScope, *AI); + + PushOnScopeChains(*AI, CurBlock->TheScope); + } + } +} + +/// ActOnBlockError - If there is an error parsing a block, this callback +/// is invoked to pop the information about the block from the action impl. +void Sema::ActOnBlockError(SourceLocation CaretLoc, Scope *CurScope) { + // Pop off CurBlock, handle nested blocks. + PopDeclContext(); + PopFunctionOrBlockScope(); +} + +/// ActOnBlockStmtExpr - This is called when the body of a block statement +/// literal was successfully completed. ^(int x){...} +ExprResult Sema::ActOnBlockStmtExpr(SourceLocation CaretLoc, + Stmt *Body, Scope *CurScope) { + // If blocks are disabled, emit an error. + if (!LangOpts.Blocks) + Diag(CaretLoc, diag::err_blocks_disable); + + BlockScopeInfo *BSI = cast<BlockScopeInfo>(FunctionScopes.back()); + + PopDeclContext(); + + QualType RetTy = Context.VoidTy; + if (!BSI->ReturnType.isNull()) + RetTy = BSI->ReturnType; + + bool NoReturn = BSI->TheDecl->getAttr<NoReturnAttr>(); + QualType BlockTy; + + // Set the captured variables on the block. + BSI->TheDecl->setCaptures(Context, BSI->Captures.begin(), BSI->Captures.end(), + BSI->CapturesCXXThis); + + // If the user wrote a function type in some form, try to use that. + if (!BSI->FunctionType.isNull()) { + const FunctionType *FTy = BSI->FunctionType->getAs<FunctionType>(); + + FunctionType::ExtInfo Ext = FTy->getExtInfo(); + if (NoReturn && !Ext.getNoReturn()) Ext = Ext.withNoReturn(true); + + // Turn protoless block types into nullary block types. + if (isa<FunctionNoProtoType>(FTy)) { + FunctionProtoType::ExtProtoInfo EPI; + EPI.ExtInfo = Ext; + BlockTy = Context.getFunctionType(RetTy, 0, 0, EPI); + + // Otherwise, if we don't need to change anything about the function type, + // preserve its sugar structure. + } else if (FTy->getResultType() == RetTy && + (!NoReturn || FTy->getNoReturnAttr())) { + BlockTy = BSI->FunctionType; + + // Otherwise, make the minimal modifications to the function type. + } else { + const FunctionProtoType *FPT = cast<FunctionProtoType>(FTy); + FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo(); + EPI.TypeQuals = 0; // FIXME: silently? + EPI.ExtInfo = Ext; + BlockTy = Context.getFunctionType(RetTy, + FPT->arg_type_begin(), + FPT->getNumArgs(), + EPI); + } + + // If we don't have a function type, just build one from nothing. + } else { + FunctionProtoType::ExtProtoInfo EPI; + EPI.ExtInfo = FunctionType::ExtInfo(NoReturn, false, 0, CC_Default); + BlockTy = Context.getFunctionType(RetTy, 0, 0, EPI); + } + + DiagnoseUnusedParameters(BSI->TheDecl->param_begin(), + BSI->TheDecl->param_end()); + BlockTy = Context.getBlockPointerType(BlockTy); + + // If needed, diagnose invalid gotos and switches in the block. + if (getCurFunction()->NeedsScopeChecking() && !hasAnyErrorsInThisFunction()) + DiagnoseInvalidJumps(cast<CompoundStmt>(Body)); + + BSI->TheDecl->setBody(cast<CompoundStmt>(Body)); + + BlockExpr *Result = new (Context) BlockExpr(BSI->TheDecl, BlockTy); + + const AnalysisBasedWarnings::Policy &WP = AnalysisWarnings.getDefaultPolicy(); + PopFunctionOrBlockScope(&WP, Result->getBlockDecl(), Result); + return Owned(Result); +} + +ExprResult Sema::ActOnVAArg(SourceLocation BuiltinLoc, + Expr *expr, ParsedType type, + SourceLocation RPLoc) { + TypeSourceInfo *TInfo; + GetTypeFromParser(type, &TInfo); + return BuildVAArgExpr(BuiltinLoc, expr, TInfo, RPLoc); +} + +ExprResult Sema::BuildVAArgExpr(SourceLocation BuiltinLoc, + Expr *E, TypeSourceInfo *TInfo, + SourceLocation RPLoc) { + Expr *OrigExpr = E; + + // Get the va_list type + QualType VaListType = Context.getBuiltinVaListType(); + if (VaListType->isArrayType()) { + // Deal with implicit array decay; for example, on x86-64, + // va_list is an array, but it's supposed to decay to + // a pointer for va_arg. + VaListType = Context.getArrayDecayedType(VaListType); + // Make sure the input expression also decays appropriately. + ExprResult Result = UsualUnaryConversions(E); + if (Result.isInvalid()) + return ExprError(); + E = Result.take(); + } else { + // Otherwise, the va_list argument must be an l-value because + // it is modified by va_arg. + if (!E->isTypeDependent() && + CheckForModifiableLvalue(E, BuiltinLoc, *this)) + return ExprError(); + } + + if (!E->isTypeDependent() && + !Context.hasSameType(VaListType, E->getType())) { + return ExprError(Diag(E->getLocStart(), + diag::err_first_argument_to_va_arg_not_of_type_va_list) + << OrigExpr->getType() << E->getSourceRange()); + } + + // FIXME: Check that type is complete/non-abstract + // FIXME: Warn if a non-POD type is passed in. + + QualType T = TInfo->getType().getNonLValueExprType(Context); + return Owned(new (Context) VAArgExpr(BuiltinLoc, E, TInfo, RPLoc, T)); +} + +ExprResult Sema::ActOnGNUNullExpr(SourceLocation TokenLoc) { + // The type of __null will be int or long, depending on the size of + // pointers on the target. + QualType Ty; + unsigned pw = Context.Target.getPointerWidth(0); + if (pw == Context.Target.getIntWidth()) + Ty = Context.IntTy; + else if (pw == Context.Target.getLongWidth()) + Ty = Context.LongTy; + else if (pw == Context.Target.getLongLongWidth()) + Ty = Context.LongLongTy; + else { + assert(!"I don't know size of pointer!"); + Ty = Context.IntTy; + } + + return Owned(new (Context) GNUNullExpr(Ty, TokenLoc)); +} + +static void MakeObjCStringLiteralFixItHint(Sema& SemaRef, QualType DstType, + Expr *SrcExpr, FixItHint &Hint) { + if (!SemaRef.getLangOptions().ObjC1) + return; + + const ObjCObjectPointerType *PT = DstType->getAs<ObjCObjectPointerType>(); + if (!PT) + return; + + // Check if the destination is of type 'id'. + if (!PT->isObjCIdType()) { + // Check if the destination is the 'NSString' interface. + const ObjCInterfaceDecl *ID = PT->getInterfaceDecl(); + if (!ID || !ID->getIdentifier()->isStr("NSString")) + return; + } + + // Strip off any parens and casts. + StringLiteral *SL = dyn_cast<StringLiteral>(SrcExpr->IgnoreParenCasts()); + if (!SL || SL->isWide()) + return; + + Hint = FixItHint::CreateInsertion(SL->getLocStart(), "@"); +} + +bool Sema::DiagnoseAssignmentResult(AssignConvertType ConvTy, + SourceLocation Loc, + QualType DstType, QualType SrcType, + Expr *SrcExpr, AssignmentAction Action, + bool *Complained) { + if (Complained) + *Complained = false; + + // Decode the result (notice that AST's are still created for extensions). + bool isInvalid = false; + unsigned DiagKind; + FixItHint Hint; + + switch (ConvTy) { + default: assert(0 && "Unknown conversion type"); + case Compatible: return false; + case PointerToInt: + DiagKind = diag::ext_typecheck_convert_pointer_int; + break; + case IntToPointer: + DiagKind = diag::ext_typecheck_convert_int_pointer; + break; + case IncompatiblePointer: + MakeObjCStringLiteralFixItHint(*this, DstType, SrcExpr, Hint); + DiagKind = diag::ext_typecheck_convert_incompatible_pointer; + break; + case IncompatiblePointerSign: + DiagKind = diag::ext_typecheck_convert_incompatible_pointer_sign; + break; + case FunctionVoidPointer: + DiagKind = diag::ext_typecheck_convert_pointer_void_func; + break; + case IncompatiblePointerDiscardsQualifiers: { + // Perform array-to-pointer decay if necessary. + if (SrcType->isArrayType()) SrcType = Context.getArrayDecayedType(SrcType); + + Qualifiers lhq = SrcType->getPointeeType().getQualifiers(); + Qualifiers rhq = DstType->getPointeeType().getQualifiers(); + if (lhq.getAddressSpace() != rhq.getAddressSpace()) { + DiagKind = diag::err_typecheck_incompatible_address_space; + break; + } + + llvm_unreachable("unknown error case for discarding qualifiers!"); + // fallthrough + } + case CompatiblePointerDiscardsQualifiers: + // If the qualifiers lost were because we were applying the + // (deprecated) C++ conversion from a string literal to a char* + // (or wchar_t*), then there was no error (C++ 4.2p2). FIXME: + // Ideally, this check would be performed in + // checkPointerTypesForAssignment. However, that would require a + // bit of refactoring (so that the second argument is an + // expression, rather than a type), which should be done as part + // of a larger effort to fix checkPointerTypesForAssignment for + // C++ semantics. + if (getLangOptions().CPlusPlus && + IsStringLiteralToNonConstPointerConversion(SrcExpr, DstType)) + return false; + DiagKind = diag::ext_typecheck_convert_discards_qualifiers; + break; + case IncompatibleNestedPointerQualifiers: + DiagKind = diag::ext_nested_pointer_qualifier_mismatch; + break; + case IntToBlockPointer: + DiagKind = diag::err_int_to_block_pointer; + break; + case IncompatibleBlockPointer: + DiagKind = diag::err_typecheck_convert_incompatible_block_pointer; + break; + case IncompatibleObjCQualifiedId: + // FIXME: Diagnose the problem in ObjCQualifiedIdTypesAreCompatible, since + // it can give a more specific diagnostic. + DiagKind = diag::warn_incompatible_qualified_id; + break; + case IncompatibleVectors: + DiagKind = diag::warn_incompatible_vectors; + break; + case Incompatible: + DiagKind = diag::err_typecheck_convert_incompatible; + isInvalid = true; + break; + } + + QualType FirstType, SecondType; + switch (Action) { + case AA_Assigning: + case AA_Initializing: + // The destination type comes first. + FirstType = DstType; + SecondType = SrcType; + break; + + case AA_Returning: + case AA_Passing: + case AA_Converting: + case AA_Sending: + case AA_Casting: + // The source type comes first. + FirstType = SrcType; + SecondType = DstType; + break; + } + + Diag(Loc, DiagKind) << FirstType << SecondType << Action + << SrcExpr->getSourceRange() << Hint; + if (Complained) + *Complained = true; + return isInvalid; +} + +bool Sema::VerifyIntegerConstantExpression(const Expr *E, llvm::APSInt *Result){ + llvm::APSInt ICEResult; + if (E->isIntegerConstantExpr(ICEResult, Context)) { + if (Result) + *Result = ICEResult; + return false; + } + + Expr::EvalResult EvalResult; + + if (!E->Evaluate(EvalResult, Context) || !EvalResult.Val.isInt() || + EvalResult.HasSideEffects) { + Diag(E->getExprLoc(), diag::err_expr_not_ice) << E->getSourceRange(); + + if (EvalResult.Diag) { + // We only show the note if it's not the usual "invalid subexpression" + // or if it's actually in a subexpression. + if (EvalResult.Diag != diag::note_invalid_subexpr_in_ice || + E->IgnoreParens() != EvalResult.DiagExpr->IgnoreParens()) + Diag(EvalResult.DiagLoc, EvalResult.Diag); + } + + return true; + } + + Diag(E->getExprLoc(), diag::ext_expr_not_ice) << + E->getSourceRange(); + + if (EvalResult.Diag && + Diags.getDiagnosticLevel(diag::ext_expr_not_ice, EvalResult.DiagLoc) + != Diagnostic::Ignored) + Diag(EvalResult.DiagLoc, EvalResult.Diag); + + if (Result) + *Result = EvalResult.Val.getInt(); + return false; +} + +void +Sema::PushExpressionEvaluationContext(ExpressionEvaluationContext NewContext) { + ExprEvalContexts.push_back( + ExpressionEvaluationContextRecord(NewContext, ExprTemporaries.size())); +} + +void +Sema::PopExpressionEvaluationContext() { + // Pop the current expression evaluation context off the stack. + ExpressionEvaluationContextRecord Rec = ExprEvalContexts.back(); + ExprEvalContexts.pop_back(); + + if (Rec.Context == PotentiallyPotentiallyEvaluated) { + if (Rec.PotentiallyReferenced) { + // Mark any remaining declarations in the current position of the stack + // as "referenced". If they were not meant to be referenced, semantic + // analysis would have eliminated them (e.g., in ActOnCXXTypeId). + for (PotentiallyReferencedDecls::iterator + I = Rec.PotentiallyReferenced->begin(), + IEnd = Rec.PotentiallyReferenced->end(); + I != IEnd; ++I) + MarkDeclarationReferenced(I->first, I->second); + } + + if (Rec.PotentiallyDiagnosed) { + // Emit any pending diagnostics. + for (PotentiallyEmittedDiagnostics::iterator + I = Rec.PotentiallyDiagnosed->begin(), + IEnd = Rec.PotentiallyDiagnosed->end(); + I != IEnd; ++I) + Diag(I->first, I->second); + } + } + + // When are coming out of an unevaluated context, clear out any + // temporaries that we may have created as part of the evaluation of + // the expression in that context: they aren't relevant because they + // will never be constructed. + if (Rec.Context == Unevaluated && + ExprTemporaries.size() > Rec.NumTemporaries) + ExprTemporaries.erase(ExprTemporaries.begin() + Rec.NumTemporaries, + ExprTemporaries.end()); + + // Destroy the popped expression evaluation record. + Rec.Destroy(); +} + +/// \brief Note that the given declaration was referenced in the source code. +/// +/// This routine should be invoke whenever a given declaration is referenced +/// in the source code, and where that reference occurred. If this declaration +/// reference means that the the declaration is used (C++ [basic.def.odr]p2, +/// C99 6.9p3), then the declaration will be marked as used. +/// +/// \param Loc the location where the declaration was referenced. +/// +/// \param D the declaration that has been referenced by the source code. +void Sema::MarkDeclarationReferenced(SourceLocation Loc, Decl *D) { + assert(D && "No declaration?"); + + D->setReferenced(); + + if (D->isUsed(false)) + return; + + // Mark a parameter or variable declaration "used", regardless of whether we're in a + // template or not. The reason for this is that unevaluated expressions + // (e.g. (void)sizeof()) constitute a use for warning purposes (-Wunused-variables and + // -Wunused-parameters) + if (isa<ParmVarDecl>(D) || + (isa<VarDecl>(D) && D->getDeclContext()->isFunctionOrMethod())) { + D->setUsed(); + return; + } + + if (!isa<VarDecl>(D) && !isa<FunctionDecl>(D)) + return; + + // Do not mark anything as "used" within a dependent context; wait for + // an instantiation. + if (CurContext->isDependentContext()) + return; + + switch (ExprEvalContexts.back().Context) { + case Unevaluated: + // We are in an expression that is not potentially evaluated; do nothing. + return; + + case PotentiallyEvaluated: + // We are in a potentially-evaluated expression, so this declaration is + // "used"; handle this below. + break; + + case PotentiallyPotentiallyEvaluated: + // We are in an expression that may be potentially evaluated; queue this + // declaration reference until we know whether the expression is + // potentially evaluated. + ExprEvalContexts.back().addReferencedDecl(Loc, D); + return; + + case PotentiallyEvaluatedIfUsed: + // Referenced declarations will only be used if the construct in the + // containing expression is used. + return; + } + + // Note that this declaration has been used. + if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) { + unsigned TypeQuals; + if (Constructor->isImplicit() && Constructor->isDefaultConstructor()) { + if (Constructor->getParent()->hasTrivialConstructor()) + return; + if (!Constructor->isUsed(false)) + DefineImplicitDefaultConstructor(Loc, Constructor); + } else if (Constructor->isImplicit() && + Constructor->isCopyConstructor(TypeQuals)) { + if (!Constructor->isUsed(false)) + DefineImplicitCopyConstructor(Loc, Constructor, TypeQuals); + } + + MarkVTableUsed(Loc, Constructor->getParent()); + } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) { + if (Destructor->isImplicit() && !Destructor->isUsed(false)) + DefineImplicitDestructor(Loc, Destructor); + if (Destructor->isVirtual()) + MarkVTableUsed(Loc, Destructor->getParent()); + } else if (CXXMethodDecl *MethodDecl = dyn_cast<CXXMethodDecl>(D)) { + if (MethodDecl->isImplicit() && MethodDecl->isOverloadedOperator() && + MethodDecl->getOverloadedOperator() == OO_Equal) { + if (!MethodDecl->isUsed(false)) + DefineImplicitCopyAssignment(Loc, MethodDecl); + } else if (MethodDecl->isVirtual()) + MarkVTableUsed(Loc, MethodDecl->getParent()); + } + if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D)) { + // Recursive functions should be marked when used from another function. + if (CurContext == Function) return; + + // Implicit instantiation of function templates and member functions of + // class templates. + if (Function->isImplicitlyInstantiable()) { + bool AlreadyInstantiated = false; + if (FunctionTemplateSpecializationInfo *SpecInfo + = Function->getTemplateSpecializationInfo()) { + if (SpecInfo->getPointOfInstantiation().isInvalid()) + SpecInfo->setPointOfInstantiation(Loc); + else if (SpecInfo->getTemplateSpecializationKind() + == TSK_ImplicitInstantiation) + AlreadyInstantiated = true; + } else if (MemberSpecializationInfo *MSInfo + = Function->getMemberSpecializationInfo()) { + if (MSInfo->getPointOfInstantiation().isInvalid()) + MSInfo->setPointOfInstantiation(Loc); + else if (MSInfo->getTemplateSpecializationKind() + == TSK_ImplicitInstantiation) + AlreadyInstantiated = true; + } + + if (!AlreadyInstantiated) { + if (isa<CXXRecordDecl>(Function->getDeclContext()) && + cast<CXXRecordDecl>(Function->getDeclContext())->isLocalClass()) + PendingLocalImplicitInstantiations.push_back(std::make_pair(Function, + Loc)); + else + PendingInstantiations.push_back(std::make_pair(Function, Loc)); + } + } else { + // Walk redefinitions, as some of them may be instantiable. + for (FunctionDecl::redecl_iterator i(Function->redecls_begin()), + e(Function->redecls_end()); i != e; ++i) { + if (!i->isUsed(false) && i->isImplicitlyInstantiable()) + MarkDeclarationReferenced(Loc, *i); + } + } + + // Keep track of used but undefined functions. + if (!Function->isPure() && !Function->hasBody() && + Function->getLinkage() != ExternalLinkage) { + SourceLocation &old = UndefinedInternals[Function->getCanonicalDecl()]; + if (old.isInvalid()) old = Loc; + } + + Function->setUsed(true); + return; + } + + if (VarDecl *Var = dyn_cast<VarDecl>(D)) { + // Implicit instantiation of static data members of class templates. + if (Var->isStaticDataMember() && + Var->getInstantiatedFromStaticDataMember()) { + MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo(); + assert(MSInfo && "Missing member specialization information?"); + if (MSInfo->getPointOfInstantiation().isInvalid() && + MSInfo->getTemplateSpecializationKind()== TSK_ImplicitInstantiation) { + MSInfo->setPointOfInstantiation(Loc); + // This is a modification of an existing AST node. Notify listeners. + if (ASTMutationListener *L = getASTMutationListener()) + L->StaticDataMemberInstantiated(Var); + PendingInstantiations.push_back(std::make_pair(Var, Loc)); + } + } + + // Keep track of used but undefined variables. We make a hole in + // the warning for static const data members with in-line + // initializers. + if (Var->hasDefinition() == VarDecl::DeclarationOnly + && Var->getLinkage() != ExternalLinkage + && !(Var->isStaticDataMember() && Var->hasInit())) { + SourceLocation &old = UndefinedInternals[Var->getCanonicalDecl()]; + if (old.isInvalid()) old = Loc; + } + + D->setUsed(true); + return; + } +} + +namespace { + // Mark all of the declarations referenced + // FIXME: Not fully implemented yet! We need to have a better understanding + // of when we're entering + class MarkReferencedDecls : public RecursiveASTVisitor<MarkReferencedDecls> { + Sema &S; + SourceLocation Loc; + + public: + typedef RecursiveASTVisitor<MarkReferencedDecls> Inherited; + + MarkReferencedDecls(Sema &S, SourceLocation Loc) : S(S), Loc(Loc) { } + + bool TraverseTemplateArgument(const TemplateArgument &Arg); + bool TraverseRecordType(RecordType *T); + }; +} + +bool MarkReferencedDecls::TraverseTemplateArgument( + const TemplateArgument &Arg) { + if (Arg.getKind() == TemplateArgument::Declaration) { + S.MarkDeclarationReferenced(Loc, Arg.getAsDecl()); + } + + return Inherited::TraverseTemplateArgument(Arg); +} + +bool MarkReferencedDecls::TraverseRecordType(RecordType *T) { + if (ClassTemplateSpecializationDecl *Spec + = dyn_cast<ClassTemplateSpecializationDecl>(T->getDecl())) { + const TemplateArgumentList &Args = Spec->getTemplateArgs(); + return TraverseTemplateArguments(Args.data(), Args.size()); + } + + return true; +} + +void Sema::MarkDeclarationsReferencedInType(SourceLocation Loc, QualType T) { + MarkReferencedDecls Marker(*this, Loc); + Marker.TraverseType(Context.getCanonicalType(T)); +} + +namespace { + /// \brief Helper class that marks all of the declarations referenced by + /// potentially-evaluated subexpressions as "referenced". + class EvaluatedExprMarker : public EvaluatedExprVisitor<EvaluatedExprMarker> { + Sema &S; + + public: + typedef EvaluatedExprVisitor<EvaluatedExprMarker> Inherited; + + explicit EvaluatedExprMarker(Sema &S) : Inherited(S.Context), S(S) { } + + void VisitDeclRefExpr(DeclRefExpr *E) { + S.MarkDeclarationReferenced(E->getLocation(), E->getDecl()); + } + + void VisitMemberExpr(MemberExpr *E) { + S.MarkDeclarationReferenced(E->getMemberLoc(), E->getMemberDecl()); + Inherited::VisitMemberExpr(E); + } + + void VisitCXXNewExpr(CXXNewExpr *E) { + if (E->getConstructor()) + S.MarkDeclarationReferenced(E->getLocStart(), E->getConstructor()); + if (E->getOperatorNew()) + S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorNew()); + if (E->getOperatorDelete()) + S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorDelete()); + Inherited::VisitCXXNewExpr(E); + } + + void VisitCXXDeleteExpr(CXXDeleteExpr *E) { + if (E->getOperatorDelete()) + S.MarkDeclarationReferenced(E->getLocStart(), E->getOperatorDelete()); + QualType Destroyed = S.Context.getBaseElementType(E->getDestroyedType()); + if (const RecordType *DestroyedRec = Destroyed->getAs<RecordType>()) { + CXXRecordDecl *Record = cast<CXXRecordDecl>(DestroyedRec->getDecl()); + S.MarkDeclarationReferenced(E->getLocStart(), + S.LookupDestructor(Record)); + } + + Inherited::VisitCXXDeleteExpr(E); + } + + void VisitCXXConstructExpr(CXXConstructExpr *E) { + S.MarkDeclarationReferenced(E->getLocStart(), E->getConstructor()); + Inherited::VisitCXXConstructExpr(E); + } + + void VisitBlockDeclRefExpr(BlockDeclRefExpr *E) { + S.MarkDeclarationReferenced(E->getLocation(), E->getDecl()); + } + + void VisitCXXDefaultArgExpr(CXXDefaultArgExpr *E) { + Visit(E->getExpr()); + } + }; +} + +/// \brief Mark any declarations that appear within this expression or any +/// potentially-evaluated subexpressions as "referenced". +void Sema::MarkDeclarationsReferencedInExpr(Expr *E) { + EvaluatedExprMarker(*this).Visit(E); +} + +/// \brief Emit a diagnostic that describes an effect on the run-time behavior +/// of the program being compiled. +/// +/// This routine emits the given diagnostic when the code currently being +/// type-checked is "potentially evaluated", meaning that there is a +/// possibility that the code will actually be executable. Code in sizeof() +/// expressions, code used only during overload resolution, etc., are not +/// potentially evaluated. This routine will suppress such diagnostics or, +/// in the absolutely nutty case of potentially potentially evaluated +/// expressions (C++ typeid), queue the diagnostic to potentially emit it +/// later. +/// +/// This routine should be used for all diagnostics that describe the run-time +/// behavior of a program, such as passing a non-POD value through an ellipsis. +/// Failure to do so will likely result in spurious diagnostics or failures +/// during overload resolution or within sizeof/alignof/typeof/typeid. +bool Sema::DiagRuntimeBehavior(SourceLocation Loc, const Stmt *stmt, + const PartialDiagnostic &PD) { + switch (ExprEvalContexts.back().Context ) { + case Unevaluated: + // The argument will never be evaluated, so don't complain. + break; + + case PotentiallyEvaluated: + case PotentiallyEvaluatedIfUsed: + if (stmt && getCurFunctionOrMethodDecl()) { + FunctionScopes.back()->PossiblyUnreachableDiags. + push_back(sema::PossiblyUnreachableDiag(PD, Loc, stmt)); + } + else + Diag(Loc, PD); + + return true; + + case PotentiallyPotentiallyEvaluated: + ExprEvalContexts.back().addDiagnostic(Loc, PD); + break; + } + + return false; +} + +bool Sema::CheckCallReturnType(QualType ReturnType, SourceLocation Loc, + CallExpr *CE, FunctionDecl *FD) { + if (ReturnType->isVoidType() || !ReturnType->isIncompleteType()) + return false; + + PartialDiagnostic Note = + FD ? PDiag(diag::note_function_with_incomplete_return_type_declared_here) + << FD->getDeclName() : PDiag(); + SourceLocation NoteLoc = FD ? FD->getLocation() : SourceLocation(); + + if (RequireCompleteType(Loc, ReturnType, + FD ? + PDiag(diag::err_call_function_incomplete_return) + << CE->getSourceRange() << FD->getDeclName() : + PDiag(diag::err_call_incomplete_return) + << CE->getSourceRange(), + std::make_pair(NoteLoc, Note))) + return true; + + return false; +} + +// Diagnose the s/=/==/ and s/\|=/!=/ typos. Note that adding parentheses +// will prevent this condition from triggering, which is what we want. +void Sema::DiagnoseAssignmentAsCondition(Expr *E) { + SourceLocation Loc; + + unsigned diagnostic = diag::warn_condition_is_assignment; + bool IsOrAssign = false; + + if (isa<BinaryOperator>(E)) { + BinaryOperator *Op = cast<BinaryOperator>(E); + if (Op->getOpcode() != BO_Assign && Op->getOpcode() != BO_OrAssign) + return; + + IsOrAssign = Op->getOpcode() == BO_OrAssign; + + // Greylist some idioms by putting them into a warning subcategory. + if (ObjCMessageExpr *ME + = dyn_cast<ObjCMessageExpr>(Op->getRHS()->IgnoreParenCasts())) { + Selector Sel = ME->getSelector(); + + // self = [<foo> init...] + if (isSelfExpr(Op->getLHS()) && Sel.getNameForSlot(0).startswith("init")) + diagnostic = diag::warn_condition_is_idiomatic_assignment; + + // <foo> = [<bar> nextObject] + else if (Sel.isUnarySelector() && Sel.getNameForSlot(0) == "nextObject") + diagnostic = diag::warn_condition_is_idiomatic_assignment; + } + + Loc = Op->getOperatorLoc(); + } else if (isa<CXXOperatorCallExpr>(E)) { + CXXOperatorCallExpr *Op = cast<CXXOperatorCallExpr>(E); + if (Op->getOperator() != OO_Equal && Op->getOperator() != OO_PipeEqual) + return; + + IsOrAssign = Op->getOperator() == OO_PipeEqual; + Loc = Op->getOperatorLoc(); + } else { + // Not an assignment. + return; + } + + Diag(Loc, diagnostic) << E->getSourceRange(); + + SourceLocation Open = E->getSourceRange().getBegin(); + SourceLocation Close = PP.getLocForEndOfToken(E->getSourceRange().getEnd()); + Diag(Loc, diag::note_condition_assign_silence) + << FixItHint::CreateInsertion(Open, "(") + << FixItHint::CreateInsertion(Close, ")"); + + if (IsOrAssign) + Diag(Loc, diag::note_condition_or_assign_to_comparison) + << FixItHint::CreateReplacement(Loc, "!="); + else + Diag(Loc, diag::note_condition_assign_to_comparison) + << FixItHint::CreateReplacement(Loc, "=="); +} + +/// \brief Redundant parentheses over an equality comparison can indicate +/// that the user intended an assignment used as condition. +void Sema::DiagnoseEqualityWithExtraParens(ParenExpr *parenE) { + // Don't warn if the parens came from a macro. + SourceLocation parenLoc = parenE->getLocStart(); + if (parenLoc.isInvalid() || parenLoc.isMacroID()) + return; + // Don't warn for dependent expressions. + if (parenE->isTypeDependent()) + return; + + Expr *E = parenE->IgnoreParens(); + + if (BinaryOperator *opE = dyn_cast<BinaryOperator>(E)) + if (opE->getOpcode() == BO_EQ && + opE->getLHS()->IgnoreParenImpCasts()->isModifiableLvalue(Context) + == Expr::MLV_Valid) { + SourceLocation Loc = opE->getOperatorLoc(); + + Diag(Loc, diag::warn_equality_with_extra_parens) << E->getSourceRange(); + Diag(Loc, diag::note_equality_comparison_silence) + << FixItHint::CreateRemoval(parenE->getSourceRange().getBegin()) + << FixItHint::CreateRemoval(parenE->getSourceRange().getEnd()); + Diag(Loc, diag::note_equality_comparison_to_assign) + << FixItHint::CreateReplacement(Loc, "="); + } +} + +ExprResult Sema::CheckBooleanCondition(Expr *E, SourceLocation Loc) { + DiagnoseAssignmentAsCondition(E); + if (ParenExpr *parenE = dyn_cast<ParenExpr>(E)) + DiagnoseEqualityWithExtraParens(parenE); + + ExprResult result = CheckPlaceholderExpr(E); + if (result.isInvalid()) return ExprError(); + E = result.take(); + + if (!E->isTypeDependent()) { + if (getLangOptions().CPlusPlus) + return CheckCXXBooleanCondition(E); // C++ 6.4p4 + + ExprResult ERes = DefaultFunctionArrayLvalueConversion(E); + if (ERes.isInvalid()) + return ExprError(); + E = ERes.take(); + + QualType T = E->getType(); + if (!T->isScalarType()) { // C99 6.8.4.1p1 + Diag(Loc, diag::err_typecheck_statement_requires_scalar) + << T << E->getSourceRange(); + return ExprError(); + } + } + + return Owned(E); +} + +ExprResult Sema::ActOnBooleanCondition(Scope *S, SourceLocation Loc, + Expr *Sub) { + if (!Sub) + return ExprError(); + + return CheckBooleanCondition(Sub, Loc); +} + +namespace { + /// A visitor for rebuilding a call to an __unknown_any expression + /// to have an appropriate type. + struct RebuildUnknownAnyFunction + : StmtVisitor<RebuildUnknownAnyFunction, ExprResult> { + + Sema &S; + + RebuildUnknownAnyFunction(Sema &S) : S(S) {} + + ExprResult VisitStmt(Stmt *S) { + llvm_unreachable("unexpected statement!"); + return ExprError(); + } + + ExprResult VisitExpr(Expr *expr) { + S.Diag(expr->getExprLoc(), diag::err_unsupported_unknown_any_call) + << expr->getSourceRange(); + return ExprError(); + } + + /// Rebuild an expression which simply semantically wraps another + /// expression which it shares the type and value kind of. + template <class T> ExprResult rebuildSugarExpr(T *expr) { + ExprResult subResult = Visit(expr->getSubExpr()); + if (subResult.isInvalid()) return ExprError(); + + Expr *subExpr = subResult.take(); + expr->setSubExpr(subExpr); + expr->setType(subExpr->getType()); + expr->setValueKind(subExpr->getValueKind()); + assert(expr->getObjectKind() == OK_Ordinary); + return expr; + } + + ExprResult VisitParenExpr(ParenExpr *paren) { + return rebuildSugarExpr(paren); + } + + ExprResult VisitUnaryExtension(UnaryOperator *op) { + return rebuildSugarExpr(op); + } + + ExprResult VisitUnaryAddrOf(UnaryOperator *op) { + ExprResult subResult = Visit(op->getSubExpr()); + if (subResult.isInvalid()) return ExprError(); + + Expr *subExpr = subResult.take(); + op->setSubExpr(subExpr); + op->setType(S.Context.getPointerType(subExpr->getType())); + assert(op->getValueKind() == VK_RValue); + assert(op->getObjectKind() == OK_Ordinary); + return op; + } + + ExprResult resolveDecl(Expr *expr, ValueDecl *decl) { + if (!isa<FunctionDecl>(decl)) return VisitExpr(expr); + + expr->setType(decl->getType()); + + assert(expr->getValueKind() == VK_RValue); + if (S.getLangOptions().CPlusPlus && + !(isa<CXXMethodDecl>(decl) && + cast<CXXMethodDecl>(decl)->isInstance())) + expr->setValueKind(VK_LValue); + + return expr; + } + + ExprResult VisitMemberExpr(MemberExpr *mem) { + return resolveDecl(mem, mem->getMemberDecl()); + } + + ExprResult VisitDeclRefExpr(DeclRefExpr *ref) { + return resolveDecl(ref, ref->getDecl()); + } + }; +} + +/// Given a function expression of unknown-any type, try to rebuild it +/// to have a function type. +static ExprResult rebuildUnknownAnyFunction(Sema &S, Expr *fn) { + ExprResult result = RebuildUnknownAnyFunction(S).Visit(fn); + if (result.isInvalid()) return ExprError(); + return S.DefaultFunctionArrayConversion(result.take()); +} + +namespace { + /// A visitor for rebuilding an expression of type __unknown_anytype + /// into one which resolves the type directly on the referring + /// expression. Strict preservation of the original source + /// structure is not a goal. + struct RebuildUnknownAnyExpr + : StmtVisitor<RebuildUnknownAnyExpr, ExprResult> { + + Sema &S; + + /// The current destination type. + QualType DestType; + + RebuildUnknownAnyExpr(Sema &S, QualType castType) + : S(S), DestType(castType) {} + + ExprResult VisitStmt(Stmt *S) { + llvm_unreachable("unexpected statement!"); + return ExprError(); + } + + ExprResult VisitExpr(Expr *expr) { + S.Diag(expr->getExprLoc(), diag::err_unsupported_unknown_any_expr) + << expr->getSourceRange(); + return ExprError(); + } + + ExprResult VisitCallExpr(CallExpr *call); + ExprResult VisitObjCMessageExpr(ObjCMessageExpr *message); + + /// Rebuild an expression which simply semantically wraps another + /// expression which it shares the type and value kind of. + template <class T> ExprResult rebuildSugarExpr(T *expr) { + ExprResult subResult = Visit(expr->getSubExpr()); + if (subResult.isInvalid()) return ExprError(); + Expr *subExpr = subResult.take(); + expr->setSubExpr(subExpr); + expr->setType(subExpr->getType()); + expr->setValueKind(subExpr->getValueKind()); + assert(expr->getObjectKind() == OK_Ordinary); + return expr; + } + + ExprResult VisitParenExpr(ParenExpr *paren) { + return rebuildSugarExpr(paren); + } + + ExprResult VisitUnaryExtension(UnaryOperator *op) { + return rebuildSugarExpr(op); + } + + ExprResult VisitUnaryAddrOf(UnaryOperator *op) { + const PointerType *ptr = DestType->getAs<PointerType>(); + if (!ptr) { + S.Diag(op->getOperatorLoc(), diag::err_unknown_any_addrof) + << op->getSourceRange(); + return ExprError(); + } + assert(op->getValueKind() == VK_RValue); + assert(op->getObjectKind() == OK_Ordinary); + op->setType(DestType); + + // Build the sub-expression as if it were an object of the pointee type. + DestType = ptr->getPointeeType(); + ExprResult subResult = Visit(op->getSubExpr()); + if (subResult.isInvalid()) return ExprError(); + op->setSubExpr(subResult.take()); + return op; + } + + ExprResult VisitImplicitCastExpr(ImplicitCastExpr *ice); + + ExprResult resolveDecl(Expr *expr, ValueDecl *decl); + + ExprResult VisitMemberExpr(MemberExpr *mem) { + return resolveDecl(mem, mem->getMemberDecl()); + } + + ExprResult VisitDeclRefExpr(DeclRefExpr *ref) { + return resolveDecl(ref, ref->getDecl()); + } + }; +} + +/// Rebuilds a call expression which yielded __unknown_anytype. +ExprResult RebuildUnknownAnyExpr::VisitCallExpr(CallExpr *call) { + Expr *callee = call->getCallee(); + + enum FnKind { + FK_MemberFunction, + FK_FunctionPointer, + FK_BlockPointer + }; + + FnKind kind; + QualType type = callee->getType(); + if (type == S.Context.BoundMemberTy) { + assert(isa<CXXMemberCallExpr>(call) || isa<CXXOperatorCallExpr>(call)); + kind = FK_MemberFunction; + type = Expr::findBoundMemberType(callee); + } else if (const PointerType *ptr = type->getAs<PointerType>()) { + type = ptr->getPointeeType(); + kind = FK_FunctionPointer; + } else { + type = type->castAs<BlockPointerType>()->getPointeeType(); + kind = FK_BlockPointer; + } + const FunctionType *fnType = type->castAs<FunctionType>(); + + // Verify that this is a legal result type of a function. + if (DestType->isArrayType() || DestType->isFunctionType()) { + unsigned diagID = diag::err_func_returning_array_function; + if (kind == FK_BlockPointer) + diagID = diag::err_block_returning_array_function; + + S.Diag(call->getExprLoc(), diagID) + << DestType->isFunctionType() << DestType; + return ExprError(); + } + + // Otherwise, go ahead and set DestType as the call's result. + call->setType(DestType.getNonLValueExprType(S.Context)); + call->setValueKind(Expr::getValueKindForType(DestType)); + assert(call->getObjectKind() == OK_Ordinary); + + // Rebuild the function type, replacing the result type with DestType. + if (const FunctionProtoType *proto = dyn_cast<FunctionProtoType>(fnType)) + DestType = S.Context.getFunctionType(DestType, + proto->arg_type_begin(), + proto->getNumArgs(), + proto->getExtProtoInfo()); + else + DestType = S.Context.getFunctionNoProtoType(DestType, + fnType->getExtInfo()); + + // Rebuild the appropriate pointer-to-function type. + switch (kind) { + case FK_MemberFunction: + // Nothing to do. + break; + + case FK_FunctionPointer: + DestType = S.Context.getPointerType(DestType); + break; + + case FK_BlockPointer: + DestType = S.Context.getBlockPointerType(DestType); + break; + } + + // Finally, we can recurse. + ExprResult calleeResult = Visit(callee); + if (!calleeResult.isUsable()) return ExprError(); + call->setCallee(calleeResult.take()); + + // Bind a temporary if necessary. + return S.MaybeBindToTemporary(call); +} + +ExprResult RebuildUnknownAnyExpr::VisitObjCMessageExpr(ObjCMessageExpr *msg) { + ObjCMethodDecl *method = msg->getMethodDecl(); + assert(method && "__unknown_anytype message without result type?"); + + // Verify that this is a legal result type of a call. + if (DestType->isArrayType() || DestType->isFunctionType()) { + S.Diag(msg->getExprLoc(), diag::err_func_returning_array_function) + << DestType->isFunctionType() << DestType; + return ExprError(); + } + + assert(method->getResultType() == S.Context.UnknownAnyTy); + method->setResultType(DestType); + + // Change the type of the message. + msg->setType(DestType.getNonReferenceType()); + msg->setValueKind(Expr::getValueKindForType(DestType)); + + return S.MaybeBindToTemporary(msg); +} + +ExprResult RebuildUnknownAnyExpr::VisitImplicitCastExpr(ImplicitCastExpr *ice) { + // The only case we should ever see here is a function-to-pointer decay. + assert(ice->getCastKind() == CK_FunctionToPointerDecay); + assert(ice->getValueKind() == VK_RValue); + assert(ice->getObjectKind() == OK_Ordinary); + + ice->setType(DestType); + + // Rebuild the sub-expression as the pointee (function) type. + DestType = DestType->castAs<PointerType>()->getPointeeType(); + + ExprResult result = Visit(ice->getSubExpr()); + if (!result.isUsable()) return ExprError(); + + ice->setSubExpr(result.take()); + return S.Owned(ice); +} + +ExprResult RebuildUnknownAnyExpr::resolveDecl(Expr *expr, ValueDecl *decl) { + ExprValueKind valueKind = VK_LValue; + QualType type = DestType; + + // We know how to make this work for certain kinds of decls: + + // - functions + if (FunctionDecl *fn = dyn_cast<FunctionDecl>(decl)) { + // This is true because FunctionDecls must always have function + // type, so we can't be resolving the entire thing at once. + assert(type->isFunctionType()); + + if (CXXMethodDecl *method = dyn_cast<CXXMethodDecl>(fn)) + if (method->isInstance()) { + valueKind = VK_RValue; + type = S.Context.BoundMemberTy; + } + + // Function references aren't l-values in C. + if (!S.getLangOptions().CPlusPlus) + valueKind = VK_RValue; + + // - variables + } else if (isa<VarDecl>(decl)) { + if (const ReferenceType *refTy = type->getAs<ReferenceType>()) { + type = refTy->getPointeeType(); + } else if (type->isFunctionType()) { + S.Diag(expr->getExprLoc(), diag::err_unknown_any_var_function_type) + << decl << expr->getSourceRange(); + return ExprError(); + } + + // - nothing else + } else { + S.Diag(expr->getExprLoc(), diag::err_unsupported_unknown_any_decl) + << decl << expr->getSourceRange(); + return ExprError(); + } + + decl->setType(DestType); + expr->setType(type); + expr->setValueKind(valueKind); + return S.Owned(expr); +} + +/// Check a cast of an unknown-any type. We intentionally only +/// trigger this for C-style casts. +ExprResult Sema::checkUnknownAnyCast(SourceRange typeRange, QualType castType, + Expr *castExpr, CastKind &castKind, + ExprValueKind &VK, CXXCastPath &path) { + // Rewrite the casted expression from scratch. + ExprResult result = RebuildUnknownAnyExpr(*this, castType).Visit(castExpr); + if (!result.isUsable()) return ExprError(); + + castExpr = result.take(); + VK = castExpr->getValueKind(); + castKind = CK_NoOp; + + return castExpr; +} + +static ExprResult diagnoseUnknownAnyExpr(Sema &S, Expr *e) { + Expr *orig = e; + unsigned diagID = diag::err_uncasted_use_of_unknown_any; + while (true) { + e = e->IgnoreParenImpCasts(); + if (CallExpr *call = dyn_cast<CallExpr>(e)) { + e = call->getCallee(); + diagID = diag::err_uncasted_call_of_unknown_any; + } else { + break; + } + } + + SourceLocation loc; + NamedDecl *d; + if (DeclRefExpr *ref = dyn_cast<DeclRefExpr>(e)) { + loc = ref->getLocation(); + d = ref->getDecl(); + } else if (MemberExpr *mem = dyn_cast<MemberExpr>(e)) { + loc = mem->getMemberLoc(); + d = mem->getMemberDecl(); + } else if (ObjCMessageExpr *msg = dyn_cast<ObjCMessageExpr>(e)) { + diagID = diag::err_uncasted_call_of_unknown_any; + loc = msg->getSelectorLoc(); + d = msg->getMethodDecl(); + assert(d && "unknown method returning __unknown_any?"); + } else { + S.Diag(e->getExprLoc(), diag::err_unsupported_unknown_any_expr) + << e->getSourceRange(); + return ExprError(); + } + + S.Diag(loc, diagID) << d << orig->getSourceRange(); + + // Never recoverable. + return ExprError(); +} + +/// Check for operands with placeholder types and complain if found. +/// Returns true if there was an error and no recovery was possible. +ExprResult Sema::CheckPlaceholderExpr(Expr *E) { + // Placeholder types are always *exactly* the appropriate builtin type. + QualType type = E->getType(); + + // Overloaded expressions. + if (type == Context.OverloadTy) + return ResolveAndFixSingleFunctionTemplateSpecialization(E, false, true, + E->getSourceRange(), + QualType(), + diag::err_ovl_unresolvable); + + // Bound member functions. + if (type == Context.BoundMemberTy) { + Diag(E->getLocStart(), diag::err_invalid_use_of_bound_member_func) + << E->getSourceRange(); + return ExprError(); + } + + // Expressions of unknown type. + if (type == Context.UnknownAnyTy) + return diagnoseUnknownAnyExpr(*this, E); + + assert(!type->isPlaceholderType()); + return Owned(E); +} + +bool Sema::CheckCaseExpression(Expr *expr) { + if (expr->isTypeDependent()) + return true; + if (expr->isValueDependent() || expr->isIntegerConstantExpr(Context)) + return expr->getType()->isIntegralOrEnumerationType(); + return false; +} |
