diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/SemaStmt.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/SemaStmt.cpp | 3307 |
1 files changed, 3307 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaStmt.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaStmt.cpp new file mode 100644 index 0000000..9bd8678 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/SemaStmt.cpp @@ -0,0 +1,3307 @@ +//===--- SemaStmt.cpp - Semantic Analysis for Statements ------------------===// +// +// 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 statements. +// +//===----------------------------------------------------------------------===// + +#include "clang/Sema/SemaInternal.h" +#include "clang/AST/ASTContext.h" +#include "clang/AST/ASTDiagnostic.h" +#include "clang/AST/CharUnits.h" +#include "clang/AST/DeclObjC.h" +#include "clang/AST/EvaluatedExprVisitor.h" +#include "clang/AST/ExprCXX.h" +#include "clang/AST/ExprObjC.h" +#include "clang/AST/StmtCXX.h" +#include "clang/AST/StmtObjC.h" +#include "clang/AST/TypeLoc.h" +#include "clang/Lex/Preprocessor.h" +#include "clang/Sema/Initialization.h" +#include "clang/Sema/Lookup.h" +#include "clang/Sema/Scope.h" +#include "clang/Sema/ScopeInfo.h" +#include "llvm/ADT/ArrayRef.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallString.h" +#include "llvm/ADT/SmallVector.h" +using namespace clang; +using namespace sema; + +StmtResult Sema::ActOnExprStmt(ExprResult FE) { + if (FE.isInvalid()) + return StmtError(); + + FE = ActOnFinishFullExpr(FE.get(), FE.get()->getExprLoc(), + /*DiscardedValue*/ true); + if (FE.isInvalid()) + return StmtError(); + + // C99 6.8.3p2: The expression in an expression statement is evaluated as a + // void expression for its side effects. Conversion to void allows any + // operand, even incomplete types. + + // Same thing in for stmt first clause (when expr) and third clause. + return Owned(static_cast<Stmt*>(FE.take())); +} + + +StmtResult Sema::ActOnExprStmtError() { + DiscardCleanupsInEvaluationContext(); + return StmtError(); +} + +StmtResult Sema::ActOnNullStmt(SourceLocation SemiLoc, + bool HasLeadingEmptyMacro) { + return Owned(new (Context) NullStmt(SemiLoc, HasLeadingEmptyMacro)); +} + +StmtResult Sema::ActOnDeclStmt(DeclGroupPtrTy dg, SourceLocation StartLoc, + SourceLocation EndLoc) { + DeclGroupRef DG = dg.get(); + + // If we have an invalid decl, just return an error. + if (DG.isNull()) return StmtError(); + + return Owned(new (Context) DeclStmt(DG, StartLoc, EndLoc)); +} + +void Sema::ActOnForEachDeclStmt(DeclGroupPtrTy dg) { + DeclGroupRef DG = dg.get(); + + // If we don't have a declaration, or we have an invalid declaration, + // just return. + if (DG.isNull() || !DG.isSingleDecl()) + return; + + Decl *decl = DG.getSingleDecl(); + if (!decl || decl->isInvalidDecl()) + return; + + // Only variable declarations are permitted. + VarDecl *var = dyn_cast<VarDecl>(decl); + if (!var) { + Diag(decl->getLocation(), diag::err_non_variable_decl_in_for); + decl->setInvalidDecl(); + return; + } + + // foreach variables are never actually initialized in the way that + // the parser came up with. + var->setInit(0); + + // In ARC, we don't need to retain the iteration variable of a fast + // enumeration loop. Rather than actually trying to catch that + // during declaration processing, we remove the consequences here. + if (getLangOpts().ObjCAutoRefCount) { + QualType type = var->getType(); + + // Only do this if we inferred the lifetime. Inferred lifetime + // will show up as a local qualifier because explicit lifetime + // should have shown up as an AttributedType instead. + if (type.getLocalQualifiers().getObjCLifetime() == Qualifiers::OCL_Strong) { + // Add 'const' and mark the variable as pseudo-strong. + var->setType(type.withConst()); + var->setARCPseudoStrong(true); + } + } +} + +/// \brief Diagnose unused '==' and '!=' as likely typos for '=' or '|='. +/// +/// Adding a cast to void (or other expression wrappers) will prevent the +/// warning from firing. +static bool DiagnoseUnusedComparison(Sema &S, const Expr *E) { + SourceLocation Loc; + bool IsNotEqual, CanAssign; + + if (const BinaryOperator *Op = dyn_cast<BinaryOperator>(E)) { + if (Op->getOpcode() != BO_EQ && Op->getOpcode() != BO_NE) + return false; + + Loc = Op->getOperatorLoc(); + IsNotEqual = Op->getOpcode() == BO_NE; + CanAssign = Op->getLHS()->IgnoreParenImpCasts()->isLValue(); + } else if (const CXXOperatorCallExpr *Op = dyn_cast<CXXOperatorCallExpr>(E)) { + if (Op->getOperator() != OO_EqualEqual && + Op->getOperator() != OO_ExclaimEqual) + return false; + + Loc = Op->getOperatorLoc(); + IsNotEqual = Op->getOperator() == OO_ExclaimEqual; + CanAssign = Op->getArg(0)->IgnoreParenImpCasts()->isLValue(); + } else { + // Not a typo-prone comparison. + return false; + } + + // Suppress warnings when the operator, suspicious as it may be, comes from + // a macro expansion. + if (S.SourceMgr.isMacroBodyExpansion(Loc)) + return false; + + S.Diag(Loc, diag::warn_unused_comparison) + << (unsigned)IsNotEqual << E->getSourceRange(); + + // If the LHS is a plausible entity to assign to, provide a fixit hint to + // correct common typos. + if (CanAssign) { + if (IsNotEqual) + S.Diag(Loc, diag::note_inequality_comparison_to_or_assign) + << FixItHint::CreateReplacement(Loc, "|="); + else + S.Diag(Loc, diag::note_equality_comparison_to_assign) + << FixItHint::CreateReplacement(Loc, "="); + } + + return true; +} + +void Sema::DiagnoseUnusedExprResult(const Stmt *S) { + if (const LabelStmt *Label = dyn_cast_or_null<LabelStmt>(S)) + return DiagnoseUnusedExprResult(Label->getSubStmt()); + + const Expr *E = dyn_cast_or_null<Expr>(S); + if (!E) + return; + SourceLocation ExprLoc = E->IgnoreParens()->getExprLoc(); + // In most cases, we don't want to warn if the expression is written in a + // macro body, or if the macro comes from a system header. If the offending + // expression is a call to a function with the warn_unused_result attribute, + // we warn no matter the location. Because of the order in which the various + // checks need to happen, we factor out the macro-related test here. + bool ShouldSuppress = + SourceMgr.isMacroBodyExpansion(ExprLoc) || + SourceMgr.isInSystemMacro(ExprLoc); + + const Expr *WarnExpr; + SourceLocation Loc; + SourceRange R1, R2; + if (!E->isUnusedResultAWarning(WarnExpr, Loc, R1, R2, Context)) + return; + + // If this is a GNU statement expression expanded from a macro, it is probably + // unused because it is a function-like macro that can be used as either an + // expression or statement. Don't warn, because it is almost certainly a + // false positive. + if (isa<StmtExpr>(E) && Loc.isMacroID()) + return; + + // Okay, we have an unused result. Depending on what the base expression is, + // we might want to make a more specific diagnostic. Check for one of these + // cases now. + unsigned DiagID = diag::warn_unused_expr; + if (const ExprWithCleanups *Temps = dyn_cast<ExprWithCleanups>(E)) + E = Temps->getSubExpr(); + if (const CXXBindTemporaryExpr *TempExpr = dyn_cast<CXXBindTemporaryExpr>(E)) + E = TempExpr->getSubExpr(); + + if (DiagnoseUnusedComparison(*this, E)) + return; + + E = WarnExpr; + if (const CallExpr *CE = dyn_cast<CallExpr>(E)) { + if (E->getType()->isVoidType()) + return; + + // If the callee has attribute pure, const, or warn_unused_result, warn with + // a more specific message to make it clear what is happening. If the call + // is written in a macro body, only warn if it has the warn_unused_result + // attribute. + if (const Decl *FD = CE->getCalleeDecl()) { + if (FD->getAttr<WarnUnusedResultAttr>()) { + Diag(Loc, diag::warn_unused_result) << R1 << R2; + return; + } + if (ShouldSuppress) + return; + if (FD->getAttr<PureAttr>()) { + Diag(Loc, diag::warn_unused_call) << R1 << R2 << "pure"; + return; + } + if (FD->getAttr<ConstAttr>()) { + Diag(Loc, diag::warn_unused_call) << R1 << R2 << "const"; + return; + } + } + } else if (ShouldSuppress) + return; + + if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) { + if (getLangOpts().ObjCAutoRefCount && ME->isDelegateInitCall()) { + Diag(Loc, diag::err_arc_unused_init_message) << R1; + return; + } + const ObjCMethodDecl *MD = ME->getMethodDecl(); + if (MD && MD->getAttr<WarnUnusedResultAttr>()) { + Diag(Loc, diag::warn_unused_result) << R1 << R2; + return; + } + } else if (const PseudoObjectExpr *POE = dyn_cast<PseudoObjectExpr>(E)) { + const Expr *Source = POE->getSyntacticForm(); + if (isa<ObjCSubscriptRefExpr>(Source)) + DiagID = diag::warn_unused_container_subscript_expr; + else + DiagID = diag::warn_unused_property_expr; + } else if (const CXXFunctionalCastExpr *FC + = dyn_cast<CXXFunctionalCastExpr>(E)) { + if (isa<CXXConstructExpr>(FC->getSubExpr()) || + isa<CXXTemporaryObjectExpr>(FC->getSubExpr())) + return; + } + // Diagnose "(void*) blah" as a typo for "(void) blah". + else if (const CStyleCastExpr *CE = dyn_cast<CStyleCastExpr>(E)) { + TypeSourceInfo *TI = CE->getTypeInfoAsWritten(); + QualType T = TI->getType(); + + // We really do want to use the non-canonical type here. + if (T == Context.VoidPtrTy) { + PointerTypeLoc TL = TI->getTypeLoc().castAs<PointerTypeLoc>(); + + Diag(Loc, diag::warn_unused_voidptr) + << FixItHint::CreateRemoval(TL.getStarLoc()); + return; + } + } + + if (E->isGLValue() && E->getType().isVolatileQualified()) { + Diag(Loc, diag::warn_unused_volatile) << R1 << R2; + return; + } + + DiagRuntimeBehavior(Loc, 0, PDiag(DiagID) << R1 << R2); +} + +void Sema::ActOnStartOfCompoundStmt() { + PushCompoundScope(); +} + +void Sema::ActOnFinishOfCompoundStmt() { + PopCompoundScope(); +} + +sema::CompoundScopeInfo &Sema::getCurCompoundScope() const { + return getCurFunction()->CompoundScopes.back(); +} + +StmtResult Sema::ActOnCompoundStmt(SourceLocation L, SourceLocation R, + ArrayRef<Stmt *> Elts, bool isStmtExpr) { + const unsigned NumElts = Elts.size(); + + // If we're in C89 mode, check that we don't have any decls after stmts. If + // so, emit an extension diagnostic. + if (!getLangOpts().C99 && !getLangOpts().CPlusPlus) { + // Note that __extension__ can be around a decl. + unsigned i = 0; + // Skip over all declarations. + for (; i != NumElts && isa<DeclStmt>(Elts[i]); ++i) + /*empty*/; + + // We found the end of the list or a statement. Scan for another declstmt. + for (; i != NumElts && !isa<DeclStmt>(Elts[i]); ++i) + /*empty*/; + + if (i != NumElts) { + Decl *D = *cast<DeclStmt>(Elts[i])->decl_begin(); + Diag(D->getLocation(), diag::ext_mixed_decls_code); + } + } + // Warn about unused expressions in statements. + for (unsigned i = 0; i != NumElts; ++i) { + // Ignore statements that are last in a statement expression. + if (isStmtExpr && i == NumElts - 1) + continue; + + DiagnoseUnusedExprResult(Elts[i]); + } + + // Check for suspicious empty body (null statement) in `for' and `while' + // statements. Don't do anything for template instantiations, this just adds + // noise. + if (NumElts != 0 && !CurrentInstantiationScope && + getCurCompoundScope().HasEmptyLoopBodies) { + for (unsigned i = 0; i != NumElts - 1; ++i) + DiagnoseEmptyLoopBody(Elts[i], Elts[i + 1]); + } + + return Owned(new (Context) CompoundStmt(Context, Elts, L, R)); +} + +StmtResult +Sema::ActOnCaseStmt(SourceLocation CaseLoc, Expr *LHSVal, + SourceLocation DotDotDotLoc, Expr *RHSVal, + SourceLocation ColonLoc) { + assert((LHSVal != 0) && "missing expression in case statement"); + + if (getCurFunction()->SwitchStack.empty()) { + Diag(CaseLoc, diag::err_case_not_in_switch); + return StmtError(); + } + + if (!getLangOpts().CPlusPlus11) { + // C99 6.8.4.2p3: The expression shall be an integer constant. + // However, GCC allows any evaluatable integer expression. + if (!LHSVal->isTypeDependent() && !LHSVal->isValueDependent()) { + LHSVal = VerifyIntegerConstantExpression(LHSVal).take(); + if (!LHSVal) + return StmtError(); + } + + // GCC extension: The expression shall be an integer constant. + + if (RHSVal && !RHSVal->isTypeDependent() && !RHSVal->isValueDependent()) { + RHSVal = VerifyIntegerConstantExpression(RHSVal).take(); + // Recover from an error by just forgetting about it. + } + } + + LHSVal = ActOnFinishFullExpr(LHSVal, LHSVal->getExprLoc(), false, + getLangOpts().CPlusPlus11).take(); + if (RHSVal) + RHSVal = ActOnFinishFullExpr(RHSVal, RHSVal->getExprLoc(), false, + getLangOpts().CPlusPlus11).take(); + + CaseStmt *CS = new (Context) CaseStmt(LHSVal, RHSVal, CaseLoc, DotDotDotLoc, + ColonLoc); + getCurFunction()->SwitchStack.back()->addSwitchCase(CS); + return Owned(CS); +} + +/// ActOnCaseStmtBody - This installs a statement as the body of a case. +void Sema::ActOnCaseStmtBody(Stmt *caseStmt, Stmt *SubStmt) { + DiagnoseUnusedExprResult(SubStmt); + + CaseStmt *CS = static_cast<CaseStmt*>(caseStmt); + CS->setSubStmt(SubStmt); +} + +StmtResult +Sema::ActOnDefaultStmt(SourceLocation DefaultLoc, SourceLocation ColonLoc, + Stmt *SubStmt, Scope *CurScope) { + DiagnoseUnusedExprResult(SubStmt); + + if (getCurFunction()->SwitchStack.empty()) { + Diag(DefaultLoc, diag::err_default_not_in_switch); + return Owned(SubStmt); + } + + DefaultStmt *DS = new (Context) DefaultStmt(DefaultLoc, ColonLoc, SubStmt); + getCurFunction()->SwitchStack.back()->addSwitchCase(DS); + return Owned(DS); +} + +StmtResult +Sema::ActOnLabelStmt(SourceLocation IdentLoc, LabelDecl *TheDecl, + SourceLocation ColonLoc, Stmt *SubStmt) { + // If the label was multiply defined, reject it now. + if (TheDecl->getStmt()) { + Diag(IdentLoc, diag::err_redefinition_of_label) << TheDecl->getDeclName(); + Diag(TheDecl->getLocation(), diag::note_previous_definition); + return Owned(SubStmt); + } + + // Otherwise, things are good. Fill in the declaration and return it. + LabelStmt *LS = new (Context) LabelStmt(IdentLoc, TheDecl, SubStmt); + TheDecl->setStmt(LS); + if (!TheDecl->isGnuLocal()) { + TheDecl->setLocStart(IdentLoc); + TheDecl->setLocation(IdentLoc); + } + return Owned(LS); +} + +StmtResult Sema::ActOnAttributedStmt(SourceLocation AttrLoc, + ArrayRef<const Attr*> Attrs, + Stmt *SubStmt) { + // Fill in the declaration and return it. + AttributedStmt *LS = AttributedStmt::Create(Context, AttrLoc, Attrs, SubStmt); + return Owned(LS); +} + +StmtResult +Sema::ActOnIfStmt(SourceLocation IfLoc, FullExprArg CondVal, Decl *CondVar, + Stmt *thenStmt, SourceLocation ElseLoc, + Stmt *elseStmt) { + // If the condition was invalid, discard the if statement. We could recover + // better by replacing it with a valid expr, but don't do that yet. + if (!CondVal.get() && !CondVar) { + getCurFunction()->setHasDroppedStmt(); + return StmtError(); + } + + ExprResult CondResult(CondVal.release()); + + VarDecl *ConditionVar = 0; + if (CondVar) { + ConditionVar = cast<VarDecl>(CondVar); + CondResult = CheckConditionVariable(ConditionVar, IfLoc, true); + if (CondResult.isInvalid()) + return StmtError(); + } + Expr *ConditionExpr = CondResult.takeAs<Expr>(); + if (!ConditionExpr) + return StmtError(); + + DiagnoseUnusedExprResult(thenStmt); + + if (!elseStmt) { + DiagnoseEmptyStmtBody(ConditionExpr->getLocEnd(), thenStmt, + diag::warn_empty_if_body); + } + + DiagnoseUnusedExprResult(elseStmt); + + return Owned(new (Context) IfStmt(Context, IfLoc, ConditionVar, ConditionExpr, + thenStmt, ElseLoc, elseStmt)); +} + +/// ConvertIntegerToTypeWarnOnOverflow - Convert the specified APInt to have +/// the specified width and sign. If an overflow occurs, detect it and emit +/// the specified diagnostic. +void Sema::ConvertIntegerToTypeWarnOnOverflow(llvm::APSInt &Val, + unsigned NewWidth, bool NewSign, + SourceLocation Loc, + unsigned DiagID) { + // Perform a conversion to the promoted condition type if needed. + if (NewWidth > Val.getBitWidth()) { + // If this is an extension, just do it. + Val = Val.extend(NewWidth); + Val.setIsSigned(NewSign); + + // If the input was signed and negative and the output is + // unsigned, don't bother to warn: this is implementation-defined + // behavior. + // FIXME: Introduce a second, default-ignored warning for this case? + } else if (NewWidth < Val.getBitWidth()) { + // If this is a truncation, check for overflow. + llvm::APSInt ConvVal(Val); + ConvVal = ConvVal.trunc(NewWidth); + ConvVal.setIsSigned(NewSign); + ConvVal = ConvVal.extend(Val.getBitWidth()); + ConvVal.setIsSigned(Val.isSigned()); + if (ConvVal != Val) + Diag(Loc, DiagID) << Val.toString(10) << ConvVal.toString(10); + + // Regardless of whether a diagnostic was emitted, really do the + // truncation. + Val = Val.trunc(NewWidth); + Val.setIsSigned(NewSign); + } else if (NewSign != Val.isSigned()) { + // Convert the sign to match the sign of the condition. This can cause + // overflow as well: unsigned(INTMIN) + // We don't diagnose this overflow, because it is implementation-defined + // behavior. + // FIXME: Introduce a second, default-ignored warning for this case? + llvm::APSInt OldVal(Val); + Val.setIsSigned(NewSign); + } +} + +namespace { + struct CaseCompareFunctor { + bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, + const llvm::APSInt &RHS) { + return LHS.first < RHS; + } + bool operator()(const std::pair<llvm::APSInt, CaseStmt*> &LHS, + const std::pair<llvm::APSInt, CaseStmt*> &RHS) { + return LHS.first < RHS.first; + } + bool operator()(const llvm::APSInt &LHS, + const std::pair<llvm::APSInt, CaseStmt*> &RHS) { + return LHS < RHS.first; + } + }; +} + +/// CmpCaseVals - Comparison predicate for sorting case values. +/// +static bool CmpCaseVals(const std::pair<llvm::APSInt, CaseStmt*>& lhs, + const std::pair<llvm::APSInt, CaseStmt*>& rhs) { + if (lhs.first < rhs.first) + return true; + + if (lhs.first == rhs.first && + lhs.second->getCaseLoc().getRawEncoding() + < rhs.second->getCaseLoc().getRawEncoding()) + return true; + return false; +} + +/// CmpEnumVals - Comparison predicate for sorting enumeration values. +/// +static bool CmpEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, + const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) +{ + return lhs.first < rhs.first; +} + +/// EqEnumVals - Comparison preficate for uniqing enumeration values. +/// +static bool EqEnumVals(const std::pair<llvm::APSInt, EnumConstantDecl*>& lhs, + const std::pair<llvm::APSInt, EnumConstantDecl*>& rhs) +{ + return lhs.first == rhs.first; +} + +/// GetTypeBeforeIntegralPromotion - Returns the pre-promotion type of +/// potentially integral-promoted expression @p expr. +static QualType GetTypeBeforeIntegralPromotion(Expr *&expr) { + if (ExprWithCleanups *cleanups = dyn_cast<ExprWithCleanups>(expr)) + expr = cleanups->getSubExpr(); + while (ImplicitCastExpr *impcast = dyn_cast<ImplicitCastExpr>(expr)) { + if (impcast->getCastKind() != CK_IntegralCast) break; + expr = impcast->getSubExpr(); + } + return expr->getType(); +} + +StmtResult +Sema::ActOnStartOfSwitchStmt(SourceLocation SwitchLoc, Expr *Cond, + Decl *CondVar) { + ExprResult CondResult; + + VarDecl *ConditionVar = 0; + if (CondVar) { + ConditionVar = cast<VarDecl>(CondVar); + CondResult = CheckConditionVariable(ConditionVar, SourceLocation(), false); + if (CondResult.isInvalid()) + return StmtError(); + + Cond = CondResult.release(); + } + + if (!Cond) + return StmtError(); + + class SwitchConvertDiagnoser : public ICEConvertDiagnoser { + Expr *Cond; + + public: + SwitchConvertDiagnoser(Expr *Cond) + : ICEConvertDiagnoser(/*AllowScopedEnumerations*/true, false, true), + Cond(Cond) {} + + virtual SemaDiagnosticBuilder diagnoseNotInt(Sema &S, SourceLocation Loc, + QualType T) { + return S.Diag(Loc, diag::err_typecheck_statement_requires_integer) << T; + } + + virtual SemaDiagnosticBuilder diagnoseIncomplete( + Sema &S, SourceLocation Loc, QualType T) { + return S.Diag(Loc, diag::err_switch_incomplete_class_type) + << T << Cond->getSourceRange(); + } + + virtual SemaDiagnosticBuilder diagnoseExplicitConv( + Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) { + return S.Diag(Loc, diag::err_switch_explicit_conversion) << T << ConvTy; + } + + virtual SemaDiagnosticBuilder noteExplicitConv( + Sema &S, CXXConversionDecl *Conv, QualType ConvTy) { + return S.Diag(Conv->getLocation(), diag::note_switch_conversion) + << ConvTy->isEnumeralType() << ConvTy; + } + + virtual SemaDiagnosticBuilder diagnoseAmbiguous(Sema &S, SourceLocation Loc, + QualType T) { + return S.Diag(Loc, diag::err_switch_multiple_conversions) << T; + } + + virtual SemaDiagnosticBuilder noteAmbiguous( + Sema &S, CXXConversionDecl *Conv, QualType ConvTy) { + return S.Diag(Conv->getLocation(), diag::note_switch_conversion) + << ConvTy->isEnumeralType() << ConvTy; + } + + virtual SemaDiagnosticBuilder diagnoseConversion( + Sema &S, SourceLocation Loc, QualType T, QualType ConvTy) { + llvm_unreachable("conversion functions are permitted"); + } + } SwitchDiagnoser(Cond); + + CondResult = + PerformContextualImplicitConversion(SwitchLoc, Cond, SwitchDiagnoser); + if (CondResult.isInvalid()) return StmtError(); + Cond = CondResult.take(); + + // C99 6.8.4.2p5 - Integer promotions are performed on the controlling expr. + CondResult = UsualUnaryConversions(Cond); + if (CondResult.isInvalid()) return StmtError(); + Cond = CondResult.take(); + + if (!CondVar) { + CondResult = ActOnFinishFullExpr(Cond, SwitchLoc); + if (CondResult.isInvalid()) + return StmtError(); + Cond = CondResult.take(); + } + + getCurFunction()->setHasBranchIntoScope(); + + SwitchStmt *SS = new (Context) SwitchStmt(Context, ConditionVar, Cond); + getCurFunction()->SwitchStack.push_back(SS); + return Owned(SS); +} + +static void AdjustAPSInt(llvm::APSInt &Val, unsigned BitWidth, bool IsSigned) { + if (Val.getBitWidth() < BitWidth) + Val = Val.extend(BitWidth); + else if (Val.getBitWidth() > BitWidth) + Val = Val.trunc(BitWidth); + Val.setIsSigned(IsSigned); +} + +StmtResult +Sema::ActOnFinishSwitchStmt(SourceLocation SwitchLoc, Stmt *Switch, + Stmt *BodyStmt) { + SwitchStmt *SS = cast<SwitchStmt>(Switch); + assert(SS == getCurFunction()->SwitchStack.back() && + "switch stack missing push/pop!"); + + SS->setBody(BodyStmt, SwitchLoc); + getCurFunction()->SwitchStack.pop_back(); + + Expr *CondExpr = SS->getCond(); + if (!CondExpr) return StmtError(); + + QualType CondType = CondExpr->getType(); + + Expr *CondExprBeforePromotion = CondExpr; + QualType CondTypeBeforePromotion = + GetTypeBeforeIntegralPromotion(CondExprBeforePromotion); + + // C++ 6.4.2.p2: + // Integral promotions are performed (on the switch condition). + // + // A case value unrepresentable by the original switch condition + // type (before the promotion) doesn't make sense, even when it can + // be represented by the promoted type. Therefore we need to find + // the pre-promotion type of the switch condition. + if (!CondExpr->isTypeDependent()) { + // We have already converted the expression to an integral or enumeration + // type, when we started the switch statement. If we don't have an + // appropriate type now, just return an error. + if (!CondType->isIntegralOrEnumerationType()) + return StmtError(); + + if (CondExpr->isKnownToHaveBooleanValue()) { + // switch(bool_expr) {...} is often a programmer error, e.g. + // switch(n && mask) { ... } // Doh - should be "n & mask". + // One can always use an if statement instead of switch(bool_expr). + Diag(SwitchLoc, diag::warn_bool_switch_condition) + << CondExpr->getSourceRange(); + } + } + + // Get the bitwidth of the switched-on value before promotions. We must + // convert the integer case values to this width before comparison. + bool HasDependentValue + = CondExpr->isTypeDependent() || CondExpr->isValueDependent(); + unsigned CondWidth + = HasDependentValue ? 0 : Context.getIntWidth(CondTypeBeforePromotion); + bool CondIsSigned + = CondTypeBeforePromotion->isSignedIntegerOrEnumerationType(); + + // Accumulate all of the case values in a vector so that we can sort them + // and detect duplicates. This vector contains the APInt for the case after + // it has been converted to the condition type. + typedef SmallVector<std::pair<llvm::APSInt, CaseStmt*>, 64> CaseValsTy; + CaseValsTy CaseVals; + + // Keep track of any GNU case ranges we see. The APSInt is the low value. + typedef std::vector<std::pair<llvm::APSInt, CaseStmt*> > CaseRangesTy; + CaseRangesTy CaseRanges; + + DefaultStmt *TheDefaultStmt = 0; + + bool CaseListIsErroneous = false; + + for (SwitchCase *SC = SS->getSwitchCaseList(); SC && !HasDependentValue; + SC = SC->getNextSwitchCase()) { + + if (DefaultStmt *DS = dyn_cast<DefaultStmt>(SC)) { + if (TheDefaultStmt) { + Diag(DS->getDefaultLoc(), diag::err_multiple_default_labels_defined); + Diag(TheDefaultStmt->getDefaultLoc(), diag::note_duplicate_case_prev); + + // FIXME: Remove the default statement from the switch block so that + // we'll return a valid AST. This requires recursing down the AST and + // finding it, not something we are set up to do right now. For now, + // just lop the entire switch stmt out of the AST. + CaseListIsErroneous = true; + } + TheDefaultStmt = DS; + + } else { + CaseStmt *CS = cast<CaseStmt>(SC); + + Expr *Lo = CS->getLHS(); + + if (Lo->isTypeDependent() || Lo->isValueDependent()) { + HasDependentValue = true; + break; + } + + llvm::APSInt LoVal; + + if (getLangOpts().CPlusPlus11) { + // C++11 [stmt.switch]p2: the constant-expression shall be a converted + // constant expression of the promoted type of the switch condition. + ExprResult ConvLo = + CheckConvertedConstantExpression(Lo, CondType, LoVal, CCEK_CaseValue); + if (ConvLo.isInvalid()) { + CaseListIsErroneous = true; + continue; + } + Lo = ConvLo.take(); + } else { + // We already verified that the expression has a i-c-e value (C99 + // 6.8.4.2p3) - get that value now. + LoVal = Lo->EvaluateKnownConstInt(Context); + + // If the LHS is not the same type as the condition, insert an implicit + // cast. + Lo = DefaultLvalueConversion(Lo).take(); + Lo = ImpCastExprToType(Lo, CondType, CK_IntegralCast).take(); + } + + // Convert the value to the same width/sign as the condition had prior to + // integral promotions. + // + // FIXME: This causes us to reject valid code: + // switch ((char)c) { case 256: case 0: return 0; } + // Here we claim there is a duplicated condition value, but there is not. + ConvertIntegerToTypeWarnOnOverflow(LoVal, CondWidth, CondIsSigned, + Lo->getLocStart(), + diag::warn_case_value_overflow); + + CS->setLHS(Lo); + + // If this is a case range, remember it in CaseRanges, otherwise CaseVals. + if (CS->getRHS()) { + if (CS->getRHS()->isTypeDependent() || + CS->getRHS()->isValueDependent()) { + HasDependentValue = true; + break; + } + CaseRanges.push_back(std::make_pair(LoVal, CS)); + } else + CaseVals.push_back(std::make_pair(LoVal, CS)); + } + } + + if (!HasDependentValue) { + // If we don't have a default statement, check whether the + // condition is constant. + llvm::APSInt ConstantCondValue; + bool HasConstantCond = false; + if (!HasDependentValue && !TheDefaultStmt) { + HasConstantCond + = CondExprBeforePromotion->EvaluateAsInt(ConstantCondValue, Context, + Expr::SE_AllowSideEffects); + assert(!HasConstantCond || + (ConstantCondValue.getBitWidth() == CondWidth && + ConstantCondValue.isSigned() == CondIsSigned)); + } + bool ShouldCheckConstantCond = HasConstantCond; + + // Sort all the scalar case values so we can easily detect duplicates. + std::stable_sort(CaseVals.begin(), CaseVals.end(), CmpCaseVals); + + if (!CaseVals.empty()) { + for (unsigned i = 0, e = CaseVals.size(); i != e; ++i) { + if (ShouldCheckConstantCond && + CaseVals[i].first == ConstantCondValue) + ShouldCheckConstantCond = false; + + if (i != 0 && CaseVals[i].first == CaseVals[i-1].first) { + // If we have a duplicate, report it. + // First, determine if either case value has a name + StringRef PrevString, CurrString; + Expr *PrevCase = CaseVals[i-1].second->getLHS()->IgnoreParenCasts(); + Expr *CurrCase = CaseVals[i].second->getLHS()->IgnoreParenCasts(); + if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(PrevCase)) { + PrevString = DeclRef->getDecl()->getName(); + } + if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(CurrCase)) { + CurrString = DeclRef->getDecl()->getName(); + } + SmallString<16> CaseValStr; + CaseVals[i-1].first.toString(CaseValStr); + + if (PrevString == CurrString) + Diag(CaseVals[i].second->getLHS()->getLocStart(), + diag::err_duplicate_case) << + (PrevString.empty() ? CaseValStr.str() : PrevString); + else + Diag(CaseVals[i].second->getLHS()->getLocStart(), + diag::err_duplicate_case_differing_expr) << + (PrevString.empty() ? CaseValStr.str() : PrevString) << + (CurrString.empty() ? CaseValStr.str() : CurrString) << + CaseValStr; + + Diag(CaseVals[i-1].second->getLHS()->getLocStart(), + diag::note_duplicate_case_prev); + // FIXME: We really want to remove the bogus case stmt from the + // substmt, but we have no way to do this right now. + CaseListIsErroneous = true; + } + } + } + + // Detect duplicate case ranges, which usually don't exist at all in + // the first place. + if (!CaseRanges.empty()) { + // Sort all the case ranges by their low value so we can easily detect + // overlaps between ranges. + std::stable_sort(CaseRanges.begin(), CaseRanges.end()); + + // Scan the ranges, computing the high values and removing empty ranges. + std::vector<llvm::APSInt> HiVals; + for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { + llvm::APSInt &LoVal = CaseRanges[i].first; + CaseStmt *CR = CaseRanges[i].second; + Expr *Hi = CR->getRHS(); + llvm::APSInt HiVal; + + if (getLangOpts().CPlusPlus11) { + // C++11 [stmt.switch]p2: the constant-expression shall be a converted + // constant expression of the promoted type of the switch condition. + ExprResult ConvHi = + CheckConvertedConstantExpression(Hi, CondType, HiVal, + CCEK_CaseValue); + if (ConvHi.isInvalid()) { + CaseListIsErroneous = true; + continue; + } + Hi = ConvHi.take(); + } else { + HiVal = Hi->EvaluateKnownConstInt(Context); + + // If the RHS is not the same type as the condition, insert an + // implicit cast. + Hi = DefaultLvalueConversion(Hi).take(); + Hi = ImpCastExprToType(Hi, CondType, CK_IntegralCast).take(); + } + + // Convert the value to the same width/sign as the condition. + ConvertIntegerToTypeWarnOnOverflow(HiVal, CondWidth, CondIsSigned, + Hi->getLocStart(), + diag::warn_case_value_overflow); + + CR->setRHS(Hi); + + // If the low value is bigger than the high value, the case is empty. + if (LoVal > HiVal) { + Diag(CR->getLHS()->getLocStart(), diag::warn_case_empty_range) + << SourceRange(CR->getLHS()->getLocStart(), + Hi->getLocEnd()); + CaseRanges.erase(CaseRanges.begin()+i); + --i, --e; + continue; + } + + if (ShouldCheckConstantCond && + LoVal <= ConstantCondValue && + ConstantCondValue <= HiVal) + ShouldCheckConstantCond = false; + + HiVals.push_back(HiVal); + } + + // Rescan the ranges, looking for overlap with singleton values and other + // ranges. Since the range list is sorted, we only need to compare case + // ranges with their neighbors. + for (unsigned i = 0, e = CaseRanges.size(); i != e; ++i) { + llvm::APSInt &CRLo = CaseRanges[i].first; + llvm::APSInt &CRHi = HiVals[i]; + CaseStmt *CR = CaseRanges[i].second; + + // Check to see whether the case range overlaps with any + // singleton cases. + CaseStmt *OverlapStmt = 0; + llvm::APSInt OverlapVal(32); + + // Find the smallest value >= the lower bound. If I is in the + // case range, then we have overlap. + CaseValsTy::iterator I = std::lower_bound(CaseVals.begin(), + CaseVals.end(), CRLo, + CaseCompareFunctor()); + if (I != CaseVals.end() && I->first < CRHi) { + OverlapVal = I->first; // Found overlap with scalar. + OverlapStmt = I->second; + } + + // Find the smallest value bigger than the upper bound. + I = std::upper_bound(I, CaseVals.end(), CRHi, CaseCompareFunctor()); + if (I != CaseVals.begin() && (I-1)->first >= CRLo) { + OverlapVal = (I-1)->first; // Found overlap with scalar. + OverlapStmt = (I-1)->second; + } + + // Check to see if this case stmt overlaps with the subsequent + // case range. + if (i && CRLo <= HiVals[i-1]) { + OverlapVal = HiVals[i-1]; // Found overlap with range. + OverlapStmt = CaseRanges[i-1].second; + } + + if (OverlapStmt) { + // If we have a duplicate, report it. + Diag(CR->getLHS()->getLocStart(), diag::err_duplicate_case) + << OverlapVal.toString(10); + Diag(OverlapStmt->getLHS()->getLocStart(), + diag::note_duplicate_case_prev); + // FIXME: We really want to remove the bogus case stmt from the + // substmt, but we have no way to do this right now. + CaseListIsErroneous = true; + } + } + } + + // Complain if we have a constant condition and we didn't find a match. + if (!CaseListIsErroneous && ShouldCheckConstantCond) { + // TODO: it would be nice if we printed enums as enums, chars as + // chars, etc. + Diag(CondExpr->getExprLoc(), diag::warn_missing_case_for_condition) + << ConstantCondValue.toString(10) + << CondExpr->getSourceRange(); + } + + // Check to see if switch is over an Enum and handles all of its + // values. We only issue a warning if there is not 'default:', but + // we still do the analysis to preserve this information in the AST + // (which can be used by flow-based analyes). + // + const EnumType *ET = CondTypeBeforePromotion->getAs<EnumType>(); + + // If switch has default case, then ignore it. + if (!CaseListIsErroneous && !HasConstantCond && ET) { + const EnumDecl *ED = ET->getDecl(); + typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl*>, 64> + EnumValsTy; + EnumValsTy EnumVals; + + // Gather all enum values, set their type and sort them, + // allowing easier comparison with CaseVals. + for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); + EDI != ED->enumerator_end(); ++EDI) { + llvm::APSInt Val = EDI->getInitVal(); + AdjustAPSInt(Val, CondWidth, CondIsSigned); + EnumVals.push_back(std::make_pair(Val, *EDI)); + } + std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); + EnumValsTy::iterator EIend = + std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); + + // See which case values aren't in enum. + EnumValsTy::const_iterator EI = EnumVals.begin(); + for (CaseValsTy::const_iterator CI = CaseVals.begin(); + CI != CaseVals.end(); CI++) { + while (EI != EIend && EI->first < CI->first) + EI++; + if (EI == EIend || EI->first > CI->first) + Diag(CI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) + << CondTypeBeforePromotion; + } + // See which of case ranges aren't in enum + EI = EnumVals.begin(); + for (CaseRangesTy::const_iterator RI = CaseRanges.begin(); + RI != CaseRanges.end() && EI != EIend; RI++) { + while (EI != EIend && EI->first < RI->first) + EI++; + + if (EI == EIend || EI->first != RI->first) { + Diag(RI->second->getLHS()->getExprLoc(), diag::warn_not_in_enum) + << CondTypeBeforePromotion; + } + + llvm::APSInt Hi = + RI->second->getRHS()->EvaluateKnownConstInt(Context); + AdjustAPSInt(Hi, CondWidth, CondIsSigned); + while (EI != EIend && EI->first < Hi) + EI++; + if (EI == EIend || EI->first != Hi) + Diag(RI->second->getRHS()->getExprLoc(), diag::warn_not_in_enum) + << CondTypeBeforePromotion; + } + + // Check which enum vals aren't in switch + CaseValsTy::const_iterator CI = CaseVals.begin(); + CaseRangesTy::const_iterator RI = CaseRanges.begin(); + bool hasCasesNotInSwitch = false; + + SmallVector<DeclarationName,8> UnhandledNames; + + for (EI = EnumVals.begin(); EI != EIend; EI++){ + // Drop unneeded case values + llvm::APSInt CIVal; + while (CI != CaseVals.end() && CI->first < EI->first) + CI++; + + if (CI != CaseVals.end() && CI->first == EI->first) + continue; + + // Drop unneeded case ranges + for (; RI != CaseRanges.end(); RI++) { + llvm::APSInt Hi = + RI->second->getRHS()->EvaluateKnownConstInt(Context); + AdjustAPSInt(Hi, CondWidth, CondIsSigned); + if (EI->first <= Hi) + break; + } + + if (RI == CaseRanges.end() || EI->first < RI->first) { + hasCasesNotInSwitch = true; + UnhandledNames.push_back(EI->second->getDeclName()); + } + } + + if (TheDefaultStmt && UnhandledNames.empty()) + Diag(TheDefaultStmt->getDefaultLoc(), diag::warn_unreachable_default); + + // Produce a nice diagnostic if multiple values aren't handled. + switch (UnhandledNames.size()) { + case 0: break; + case 1: + Diag(CondExpr->getExprLoc(), TheDefaultStmt + ? diag::warn_def_missing_case1 : diag::warn_missing_case1) + << UnhandledNames[0]; + break; + case 2: + Diag(CondExpr->getExprLoc(), TheDefaultStmt + ? diag::warn_def_missing_case2 : diag::warn_missing_case2) + << UnhandledNames[0] << UnhandledNames[1]; + break; + case 3: + Diag(CondExpr->getExprLoc(), TheDefaultStmt + ? diag::warn_def_missing_case3 : diag::warn_missing_case3) + << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; + break; + default: + Diag(CondExpr->getExprLoc(), TheDefaultStmt + ? diag::warn_def_missing_cases : diag::warn_missing_cases) + << (unsigned)UnhandledNames.size() + << UnhandledNames[0] << UnhandledNames[1] << UnhandledNames[2]; + break; + } + + if (!hasCasesNotInSwitch) + SS->setAllEnumCasesCovered(); + } + } + + DiagnoseEmptyStmtBody(CondExpr->getLocEnd(), BodyStmt, + diag::warn_empty_switch_body); + + // FIXME: If the case list was broken is some way, we don't have a good system + // to patch it up. Instead, just return the whole substmt as broken. + if (CaseListIsErroneous) + return StmtError(); + + return Owned(SS); +} + +void +Sema::DiagnoseAssignmentEnum(QualType DstType, QualType SrcType, + Expr *SrcExpr) { + if (Diags.getDiagnosticLevel(diag::warn_not_in_enum_assignment, + SrcExpr->getExprLoc()) == + DiagnosticsEngine::Ignored) + return; + + if (const EnumType *ET = DstType->getAs<EnumType>()) + if (!Context.hasSameType(SrcType, DstType) && + SrcType->isIntegerType()) { + if (!SrcExpr->isTypeDependent() && !SrcExpr->isValueDependent() && + SrcExpr->isIntegerConstantExpr(Context)) { + // Get the bitwidth of the enum value before promotions. + unsigned DstWidth = Context.getIntWidth(DstType); + bool DstIsSigned = DstType->isSignedIntegerOrEnumerationType(); + + llvm::APSInt RhsVal = SrcExpr->EvaluateKnownConstInt(Context); + AdjustAPSInt(RhsVal, DstWidth, DstIsSigned); + const EnumDecl *ED = ET->getDecl(); + typedef SmallVector<std::pair<llvm::APSInt, EnumConstantDecl *>, 64> + EnumValsTy; + EnumValsTy EnumVals; + + // Gather all enum values, set their type and sort them, + // allowing easier comparison with rhs constant. + for (EnumDecl::enumerator_iterator EDI = ED->enumerator_begin(); + EDI != ED->enumerator_end(); ++EDI) { + llvm::APSInt Val = EDI->getInitVal(); + AdjustAPSInt(Val, DstWidth, DstIsSigned); + EnumVals.push_back(std::make_pair(Val, *EDI)); + } + if (EnumVals.empty()) + return; + std::stable_sort(EnumVals.begin(), EnumVals.end(), CmpEnumVals); + EnumValsTy::iterator EIend = + std::unique(EnumVals.begin(), EnumVals.end(), EqEnumVals); + + // See which values aren't in the enum. + EnumValsTy::const_iterator EI = EnumVals.begin(); + while (EI != EIend && EI->first < RhsVal) + EI++; + if (EI == EIend || EI->first != RhsVal) { + Diag(SrcExpr->getExprLoc(), diag::warn_not_in_enum_assignment) + << DstType; + } + } + } +} + +StmtResult +Sema::ActOnWhileStmt(SourceLocation WhileLoc, FullExprArg Cond, + Decl *CondVar, Stmt *Body) { + ExprResult CondResult(Cond.release()); + + VarDecl *ConditionVar = 0; + if (CondVar) { + ConditionVar = cast<VarDecl>(CondVar); + CondResult = CheckConditionVariable(ConditionVar, WhileLoc, true); + if (CondResult.isInvalid()) + return StmtError(); + } + Expr *ConditionExpr = CondResult.take(); + if (!ConditionExpr) + return StmtError(); + + DiagnoseUnusedExprResult(Body); + + if (isa<NullStmt>(Body)) + getCurCompoundScope().setHasEmptyLoopBodies(); + + return Owned(new (Context) WhileStmt(Context, ConditionVar, ConditionExpr, + Body, WhileLoc)); +} + +StmtResult +Sema::ActOnDoStmt(SourceLocation DoLoc, Stmt *Body, + SourceLocation WhileLoc, SourceLocation CondLParen, + Expr *Cond, SourceLocation CondRParen) { + assert(Cond && "ActOnDoStmt(): missing expression"); + + ExprResult CondResult = CheckBooleanCondition(Cond, DoLoc); + if (CondResult.isInvalid()) + return StmtError(); + Cond = CondResult.take(); + + CondResult = ActOnFinishFullExpr(Cond, DoLoc); + if (CondResult.isInvalid()) + return StmtError(); + Cond = CondResult.take(); + + DiagnoseUnusedExprResult(Body); + + return Owned(new (Context) DoStmt(Body, Cond, DoLoc, WhileLoc, CondRParen)); +} + +namespace { + // This visitor will traverse a conditional statement and store all + // the evaluated decls into a vector. Simple is set to true if none + // of the excluded constructs are used. + class DeclExtractor : public EvaluatedExprVisitor<DeclExtractor> { + llvm::SmallPtrSet<VarDecl*, 8> &Decls; + SmallVectorImpl<SourceRange> &Ranges; + bool Simple; + public: + typedef EvaluatedExprVisitor<DeclExtractor> Inherited; + + DeclExtractor(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, + SmallVectorImpl<SourceRange> &Ranges) : + Inherited(S.Context), + Decls(Decls), + Ranges(Ranges), + Simple(true) {} + + bool isSimple() { return Simple; } + + // Replaces the method in EvaluatedExprVisitor. + void VisitMemberExpr(MemberExpr* E) { + Simple = false; + } + + // Any Stmt not whitelisted will cause the condition to be marked complex. + void VisitStmt(Stmt *S) { + Simple = false; + } + + void VisitBinaryOperator(BinaryOperator *E) { + Visit(E->getLHS()); + Visit(E->getRHS()); + } + + void VisitCastExpr(CastExpr *E) { + Visit(E->getSubExpr()); + } + + void VisitUnaryOperator(UnaryOperator *E) { + // Skip checking conditionals with derefernces. + if (E->getOpcode() == UO_Deref) + Simple = false; + else + Visit(E->getSubExpr()); + } + + void VisitConditionalOperator(ConditionalOperator *E) { + Visit(E->getCond()); + Visit(E->getTrueExpr()); + Visit(E->getFalseExpr()); + } + + void VisitParenExpr(ParenExpr *E) { + Visit(E->getSubExpr()); + } + + void VisitBinaryConditionalOperator(BinaryConditionalOperator *E) { + Visit(E->getOpaqueValue()->getSourceExpr()); + Visit(E->getFalseExpr()); + } + + void VisitIntegerLiteral(IntegerLiteral *E) { } + void VisitFloatingLiteral(FloatingLiteral *E) { } + void VisitCXXBoolLiteralExpr(CXXBoolLiteralExpr *E) { } + void VisitCharacterLiteral(CharacterLiteral *E) { } + void VisitGNUNullExpr(GNUNullExpr *E) { } + void VisitImaginaryLiteral(ImaginaryLiteral *E) { } + + void VisitDeclRefExpr(DeclRefExpr *E) { + VarDecl *VD = dyn_cast<VarDecl>(E->getDecl()); + if (!VD) return; + + Ranges.push_back(E->getSourceRange()); + + Decls.insert(VD); + } + + }; // end class DeclExtractor + + // DeclMatcher checks to see if the decls are used in a non-evauluated + // context. + class DeclMatcher : public EvaluatedExprVisitor<DeclMatcher> { + llvm::SmallPtrSet<VarDecl*, 8> &Decls; + bool FoundDecl; + + public: + typedef EvaluatedExprVisitor<DeclMatcher> Inherited; + + DeclMatcher(Sema &S, llvm::SmallPtrSet<VarDecl*, 8> &Decls, + Stmt *Statement) : + Inherited(S.Context), Decls(Decls), FoundDecl(false) { + if (!Statement) return; + + Visit(Statement); + } + + void VisitReturnStmt(ReturnStmt *S) { + FoundDecl = true; + } + + void VisitBreakStmt(BreakStmt *S) { + FoundDecl = true; + } + + void VisitGotoStmt(GotoStmt *S) { + FoundDecl = true; + } + + void VisitCastExpr(CastExpr *E) { + if (E->getCastKind() == CK_LValueToRValue) + CheckLValueToRValueCast(E->getSubExpr()); + else + Visit(E->getSubExpr()); + } + + void CheckLValueToRValueCast(Expr *E) { + E = E->IgnoreParenImpCasts(); + + if (isa<DeclRefExpr>(E)) { + return; + } + + if (ConditionalOperator *CO = dyn_cast<ConditionalOperator>(E)) { + Visit(CO->getCond()); + CheckLValueToRValueCast(CO->getTrueExpr()); + CheckLValueToRValueCast(CO->getFalseExpr()); + return; + } + + if (BinaryConditionalOperator *BCO = + dyn_cast<BinaryConditionalOperator>(E)) { + CheckLValueToRValueCast(BCO->getOpaqueValue()->getSourceExpr()); + CheckLValueToRValueCast(BCO->getFalseExpr()); + return; + } + + Visit(E); + } + + void VisitDeclRefExpr(DeclRefExpr *E) { + if (VarDecl *VD = dyn_cast<VarDecl>(E->getDecl())) + if (Decls.count(VD)) + FoundDecl = true; + } + + bool FoundDeclInUse() { return FoundDecl; } + + }; // end class DeclMatcher + + void CheckForLoopConditionalStatement(Sema &S, Expr *Second, + Expr *Third, Stmt *Body) { + // Condition is empty + if (!Second) return; + + if (S.Diags.getDiagnosticLevel(diag::warn_variables_not_in_loop_body, + Second->getLocStart()) + == DiagnosticsEngine::Ignored) + return; + + PartialDiagnostic PDiag = S.PDiag(diag::warn_variables_not_in_loop_body); + llvm::SmallPtrSet<VarDecl*, 8> Decls; + SmallVector<SourceRange, 10> Ranges; + DeclExtractor DE(S, Decls, Ranges); + DE.Visit(Second); + + // Don't analyze complex conditionals. + if (!DE.isSimple()) return; + + // No decls found. + if (Decls.size() == 0) return; + + // Don't warn on volatile, static, or global variables. + for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), + E = Decls.end(); + I != E; ++I) + if ((*I)->getType().isVolatileQualified() || + (*I)->hasGlobalStorage()) return; + + if (DeclMatcher(S, Decls, Second).FoundDeclInUse() || + DeclMatcher(S, Decls, Third).FoundDeclInUse() || + DeclMatcher(S, Decls, Body).FoundDeclInUse()) + return; + + // Load decl names into diagnostic. + if (Decls.size() > 4) + PDiag << 0; + else { + PDiag << Decls.size(); + for (llvm::SmallPtrSet<VarDecl*, 8>::iterator I = Decls.begin(), + E = Decls.end(); + I != E; ++I) + PDiag << (*I)->getDeclName(); + } + + // Load SourceRanges into diagnostic if there is room. + // Otherwise, load the SourceRange of the conditional expression. + if (Ranges.size() <= PartialDiagnostic::MaxArguments) + for (SmallVectorImpl<SourceRange>::iterator I = Ranges.begin(), + E = Ranges.end(); + I != E; ++I) + PDiag << *I; + else + PDiag << Second->getSourceRange(); + + S.Diag(Ranges.begin()->getBegin(), PDiag); + } + + // If Statement is an incemement or decrement, return true and sets the + // variables Increment and DRE. + bool ProcessIterationStmt(Sema &S, Stmt* Statement, bool &Increment, + DeclRefExpr *&DRE) { + if (UnaryOperator *UO = dyn_cast<UnaryOperator>(Statement)) { + switch (UO->getOpcode()) { + default: return false; + case UO_PostInc: + case UO_PreInc: + Increment = true; + break; + case UO_PostDec: + case UO_PreDec: + Increment = false; + break; + } + DRE = dyn_cast<DeclRefExpr>(UO->getSubExpr()); + return DRE; + } + + if (CXXOperatorCallExpr *Call = dyn_cast<CXXOperatorCallExpr>(Statement)) { + FunctionDecl *FD = Call->getDirectCallee(); + if (!FD || !FD->isOverloadedOperator()) return false; + switch (FD->getOverloadedOperator()) { + default: return false; + case OO_PlusPlus: + Increment = true; + break; + case OO_MinusMinus: + Increment = false; + break; + } + DRE = dyn_cast<DeclRefExpr>(Call->getArg(0)); + return DRE; + } + + return false; + } + + // A visitor to determine if a continue statement is a subexpression. + class ContinueFinder : public EvaluatedExprVisitor<ContinueFinder> { + bool Found; + public: + ContinueFinder(Sema &S, Stmt* Body) : + Inherited(S.Context), + Found(false) { + Visit(Body); + } + + typedef EvaluatedExprVisitor<ContinueFinder> Inherited; + + void VisitContinueStmt(ContinueStmt* E) { + Found = true; + } + + bool ContinueFound() { return Found; } + + }; // end class ContinueFinder + + // Emit a warning when a loop increment/decrement appears twice per loop + // iteration. The conditions which trigger this warning are: + // 1) The last statement in the loop body and the third expression in the + // for loop are both increment or both decrement of the same variable + // 2) No continue statements in the loop body. + void CheckForRedundantIteration(Sema &S, Expr *Third, Stmt *Body) { + // Return when there is nothing to check. + if (!Body || !Third) return; + + if (S.Diags.getDiagnosticLevel(diag::warn_redundant_loop_iteration, + Third->getLocStart()) + == DiagnosticsEngine::Ignored) + return; + + // Get the last statement from the loop body. + CompoundStmt *CS = dyn_cast<CompoundStmt>(Body); + if (!CS || CS->body_empty()) return; + Stmt *LastStmt = CS->body_back(); + if (!LastStmt) return; + + bool LoopIncrement, LastIncrement; + DeclRefExpr *LoopDRE, *LastDRE; + + if (!ProcessIterationStmt(S, Third, LoopIncrement, LoopDRE)) return; + if (!ProcessIterationStmt(S, LastStmt, LastIncrement, LastDRE)) return; + + // Check that the two statements are both increments or both decrements + // on the same varaible. + if (LoopIncrement != LastIncrement || + LoopDRE->getDecl() != LastDRE->getDecl()) return; + + if (ContinueFinder(S, Body).ContinueFound()) return; + + S.Diag(LastDRE->getLocation(), diag::warn_redundant_loop_iteration) + << LastDRE->getDecl() << LastIncrement; + S.Diag(LoopDRE->getLocation(), diag::note_loop_iteration_here) + << LoopIncrement; + } + +} // end namespace + +StmtResult +Sema::ActOnForStmt(SourceLocation ForLoc, SourceLocation LParenLoc, + Stmt *First, FullExprArg second, Decl *secondVar, + FullExprArg third, + SourceLocation RParenLoc, Stmt *Body) { + if (!getLangOpts().CPlusPlus) { + if (DeclStmt *DS = dyn_cast_or_null<DeclStmt>(First)) { + // C99 6.8.5p3: The declaration part of a 'for' statement shall only + // declare identifiers for objects having storage class 'auto' or + // 'register'. + for (DeclStmt::decl_iterator DI=DS->decl_begin(), DE=DS->decl_end(); + DI!=DE; ++DI) { + VarDecl *VD = dyn_cast<VarDecl>(*DI); + if (VD && VD->isLocalVarDecl() && !VD->hasLocalStorage()) + VD = 0; + if (VD == 0) { + Diag((*DI)->getLocation(), diag::err_non_local_variable_decl_in_for); + (*DI)->setInvalidDecl(); + } + } + } + } + + CheckForLoopConditionalStatement(*this, second.get(), third.get(), Body); + CheckForRedundantIteration(*this, third.get(), Body); + + ExprResult SecondResult(second.release()); + VarDecl *ConditionVar = 0; + if (secondVar) { + ConditionVar = cast<VarDecl>(secondVar); + SecondResult = CheckConditionVariable(ConditionVar, ForLoc, true); + if (SecondResult.isInvalid()) + return StmtError(); + } + + Expr *Third = third.release().takeAs<Expr>(); + + DiagnoseUnusedExprResult(First); + DiagnoseUnusedExprResult(Third); + DiagnoseUnusedExprResult(Body); + + if (isa<NullStmt>(Body)) + getCurCompoundScope().setHasEmptyLoopBodies(); + + return Owned(new (Context) ForStmt(Context, First, + SecondResult.take(), ConditionVar, + Third, Body, ForLoc, LParenLoc, + RParenLoc)); +} + +/// In an Objective C collection iteration statement: +/// for (x in y) +/// x can be an arbitrary l-value expression. Bind it up as a +/// full-expression. +StmtResult Sema::ActOnForEachLValueExpr(Expr *E) { + // Reduce placeholder expressions here. Note that this rejects the + // use of pseudo-object l-values in this position. + ExprResult result = CheckPlaceholderExpr(E); + if (result.isInvalid()) return StmtError(); + E = result.take(); + + ExprResult FullExpr = ActOnFinishFullExpr(E); + if (FullExpr.isInvalid()) + return StmtError(); + return StmtResult(static_cast<Stmt*>(FullExpr.take())); +} + +ExprResult +Sema::CheckObjCForCollectionOperand(SourceLocation forLoc, Expr *collection) { + if (!collection) + return ExprError(); + + // Bail out early if we've got a type-dependent expression. + if (collection->isTypeDependent()) return Owned(collection); + + // Perform normal l-value conversion. + ExprResult result = DefaultFunctionArrayLvalueConversion(collection); + if (result.isInvalid()) + return ExprError(); + collection = result.take(); + + // The operand needs to have object-pointer type. + // TODO: should we do a contextual conversion? + const ObjCObjectPointerType *pointerType = + collection->getType()->getAs<ObjCObjectPointerType>(); + if (!pointerType) + return Diag(forLoc, diag::err_collection_expr_type) + << collection->getType() << collection->getSourceRange(); + + // Check that the operand provides + // - countByEnumeratingWithState:objects:count: + const ObjCObjectType *objectType = pointerType->getObjectType(); + ObjCInterfaceDecl *iface = objectType->getInterface(); + + // If we have a forward-declared type, we can't do this check. + // Under ARC, it is an error not to have a forward-declared class. + if (iface && + RequireCompleteType(forLoc, QualType(objectType, 0), + getLangOpts().ObjCAutoRefCount + ? diag::err_arc_collection_forward + : 0, + collection)) { + // Otherwise, if we have any useful type information, check that + // the type declares the appropriate method. + } else if (iface || !objectType->qual_empty()) { + IdentifierInfo *selectorIdents[] = { + &Context.Idents.get("countByEnumeratingWithState"), + &Context.Idents.get("objects"), + &Context.Idents.get("count") + }; + Selector selector = Context.Selectors.getSelector(3, &selectorIdents[0]); + + ObjCMethodDecl *method = 0; + + // If there's an interface, look in both the public and private APIs. + if (iface) { + method = iface->lookupInstanceMethod(selector); + if (!method) method = iface->lookupPrivateMethod(selector); + } + + // Also check protocol qualifiers. + if (!method) + method = LookupMethodInQualifiedType(selector, pointerType, + /*instance*/ true); + + // If we didn't find it anywhere, give up. + if (!method) { + Diag(forLoc, diag::warn_collection_expr_type) + << collection->getType() << selector << collection->getSourceRange(); + } + + // TODO: check for an incompatible signature? + } + + // Wrap up any cleanups in the expression. + return Owned(collection); +} + +StmtResult +Sema::ActOnObjCForCollectionStmt(SourceLocation ForLoc, + Stmt *First, Expr *collection, + SourceLocation RParenLoc) { + + ExprResult CollectionExprResult = + CheckObjCForCollectionOperand(ForLoc, collection); + + if (First) { + QualType FirstType; + if (DeclStmt *DS = dyn_cast<DeclStmt>(First)) { + if (!DS->isSingleDecl()) + return StmtError(Diag((*DS->decl_begin())->getLocation(), + diag::err_toomany_element_decls)); + + VarDecl *D = dyn_cast<VarDecl>(DS->getSingleDecl()); + if (!D || D->isInvalidDecl()) + return StmtError(); + + FirstType = D->getType(); + // C99 6.8.5p3: The declaration part of a 'for' statement shall only + // declare identifiers for objects having storage class 'auto' or + // 'register'. + if (!D->hasLocalStorage()) + return StmtError(Diag(D->getLocation(), + diag::err_non_local_variable_decl_in_for)); + + // If the type contained 'auto', deduce the 'auto' to 'id'. + if (FirstType->getContainedAutoType()) { + OpaqueValueExpr OpaqueId(D->getLocation(), Context.getObjCIdType(), + VK_RValue); + Expr *DeducedInit = &OpaqueId; + if (DeduceAutoType(D->getTypeSourceInfo(), DeducedInit, FirstType) == + DAR_Failed) + DiagnoseAutoDeductionFailure(D, DeducedInit); + if (FirstType.isNull()) { + D->setInvalidDecl(); + return StmtError(); + } + + D->setType(FirstType); + + if (ActiveTemplateInstantiations.empty()) { + SourceLocation Loc = + D->getTypeSourceInfo()->getTypeLoc().getBeginLoc(); + Diag(Loc, diag::warn_auto_var_is_id) + << D->getDeclName(); + } + } + + } else { + Expr *FirstE = cast<Expr>(First); + if (!FirstE->isTypeDependent() && !FirstE->isLValue()) + return StmtError(Diag(First->getLocStart(), + diag::err_selector_element_not_lvalue) + << First->getSourceRange()); + + FirstType = static_cast<Expr*>(First)->getType(); + if (FirstType.isConstQualified()) + Diag(ForLoc, diag::err_selector_element_const_type) + << FirstType << First->getSourceRange(); + } + if (!FirstType->isDependentType() && + !FirstType->isObjCObjectPointerType() && + !FirstType->isBlockPointerType()) + return StmtError(Diag(ForLoc, diag::err_selector_element_type) + << FirstType << First->getSourceRange()); + } + + if (CollectionExprResult.isInvalid()) + return StmtError(); + + CollectionExprResult = ActOnFinishFullExpr(CollectionExprResult.take()); + if (CollectionExprResult.isInvalid()) + return StmtError(); + + return Owned(new (Context) ObjCForCollectionStmt(First, + CollectionExprResult.take(), 0, + ForLoc, RParenLoc)); +} + +/// Finish building a variable declaration for a for-range statement. +/// \return true if an error occurs. +static bool FinishForRangeVarDecl(Sema &SemaRef, VarDecl *Decl, Expr *Init, + SourceLocation Loc, int DiagID) { + // Deduce the type for the iterator variable now rather than leaving it to + // AddInitializerToDecl, so we can produce a more suitable diagnostic. + QualType InitType; + if ((!isa<InitListExpr>(Init) && Init->getType()->isVoidType()) || + SemaRef.DeduceAutoType(Decl->getTypeSourceInfo(), Init, InitType) == + Sema::DAR_Failed) + SemaRef.Diag(Loc, DiagID) << Init->getType(); + if (InitType.isNull()) { + Decl->setInvalidDecl(); + return true; + } + Decl->setType(InitType); + + // In ARC, infer lifetime. + // FIXME: ARC may want to turn this into 'const __unsafe_unretained' if + // we're doing the equivalent of fast iteration. + if (SemaRef.getLangOpts().ObjCAutoRefCount && + SemaRef.inferObjCARCLifetime(Decl)) + Decl->setInvalidDecl(); + + SemaRef.AddInitializerToDecl(Decl, Init, /*DirectInit=*/false, + /*TypeMayContainAuto=*/false); + SemaRef.FinalizeDeclaration(Decl); + SemaRef.CurContext->addHiddenDecl(Decl); + return false; +} + +namespace { + +/// Produce a note indicating which begin/end function was implicitly called +/// by a C++11 for-range statement. This is often not obvious from the code, +/// nor from the diagnostics produced when analysing the implicit expressions +/// required in a for-range statement. +void NoteForRangeBeginEndFunction(Sema &SemaRef, Expr *E, + Sema::BeginEndFunction BEF) { + CallExpr *CE = dyn_cast<CallExpr>(E); + if (!CE) + return; + FunctionDecl *D = dyn_cast<FunctionDecl>(CE->getCalleeDecl()); + if (!D) + return; + SourceLocation Loc = D->getLocation(); + + std::string Description; + bool IsTemplate = false; + if (FunctionTemplateDecl *FunTmpl = D->getPrimaryTemplate()) { + Description = SemaRef.getTemplateArgumentBindingsText( + FunTmpl->getTemplateParameters(), *D->getTemplateSpecializationArgs()); + IsTemplate = true; + } + + SemaRef.Diag(Loc, diag::note_for_range_begin_end) + << BEF << IsTemplate << Description << E->getType(); +} + +/// Build a variable declaration for a for-range statement. +VarDecl *BuildForRangeVarDecl(Sema &SemaRef, SourceLocation Loc, + QualType Type, const char *Name) { + DeclContext *DC = SemaRef.CurContext; + IdentifierInfo *II = &SemaRef.PP.getIdentifierTable().get(Name); + TypeSourceInfo *TInfo = SemaRef.Context.getTrivialTypeSourceInfo(Type, Loc); + VarDecl *Decl = VarDecl::Create(SemaRef.Context, DC, Loc, Loc, II, Type, + TInfo, SC_None); + Decl->setImplicit(); + return Decl; +} + +} + +static bool ObjCEnumerationCollection(Expr *Collection) { + return !Collection->isTypeDependent() + && Collection->getType()->getAs<ObjCObjectPointerType>() != 0; +} + +/// ActOnCXXForRangeStmt - Check and build a C++11 for-range statement. +/// +/// C++11 [stmt.ranged]: +/// A range-based for statement is equivalent to +/// +/// { +/// auto && __range = range-init; +/// for ( auto __begin = begin-expr, +/// __end = end-expr; +/// __begin != __end; +/// ++__begin ) { +/// for-range-declaration = *__begin; +/// statement +/// } +/// } +/// +/// The body of the loop is not available yet, since it cannot be analysed until +/// we have determined the type of the for-range-declaration. +StmtResult +Sema::ActOnCXXForRangeStmt(SourceLocation ForLoc, + Stmt *First, SourceLocation ColonLoc, Expr *Range, + SourceLocation RParenLoc, BuildForRangeKind Kind) { + if (!First) + return StmtError(); + + if (Range && ObjCEnumerationCollection(Range)) + return ActOnObjCForCollectionStmt(ForLoc, First, Range, RParenLoc); + + DeclStmt *DS = dyn_cast<DeclStmt>(First); + assert(DS && "first part of for range not a decl stmt"); + + if (!DS->isSingleDecl()) { + Diag(DS->getStartLoc(), diag::err_type_defined_in_for_range); + return StmtError(); + } + + Decl *LoopVar = DS->getSingleDecl(); + if (LoopVar->isInvalidDecl() || !Range || + DiagnoseUnexpandedParameterPack(Range, UPPC_Expression)) { + LoopVar->setInvalidDecl(); + return StmtError(); + } + + // Build auto && __range = range-init + SourceLocation RangeLoc = Range->getLocStart(); + VarDecl *RangeVar = BuildForRangeVarDecl(*this, RangeLoc, + Context.getAutoRRefDeductType(), + "__range"); + if (FinishForRangeVarDecl(*this, RangeVar, Range, RangeLoc, + diag::err_for_range_deduction_failure)) { + LoopVar->setInvalidDecl(); + return StmtError(); + } + + // Claim the type doesn't contain auto: we've already done the checking. + DeclGroupPtrTy RangeGroup = + BuildDeclaratorGroup(llvm::MutableArrayRef<Decl *>((Decl **)&RangeVar, 1), + /*TypeMayContainAuto=*/ false); + StmtResult RangeDecl = ActOnDeclStmt(RangeGroup, RangeLoc, RangeLoc); + if (RangeDecl.isInvalid()) { + LoopVar->setInvalidDecl(); + return StmtError(); + } + + return BuildCXXForRangeStmt(ForLoc, ColonLoc, RangeDecl.get(), + /*BeginEndDecl=*/0, /*Cond=*/0, /*Inc=*/0, DS, + RParenLoc, Kind); +} + +/// \brief Create the initialization, compare, and increment steps for +/// the range-based for loop expression. +/// This function does not handle array-based for loops, +/// which are created in Sema::BuildCXXForRangeStmt. +/// +/// \returns a ForRangeStatus indicating success or what kind of error occurred. +/// BeginExpr and EndExpr are set and FRS_Success is returned on success; +/// CandidateSet and BEF are set and some non-success value is returned on +/// failure. +static Sema::ForRangeStatus BuildNonArrayForRange(Sema &SemaRef, Scope *S, + Expr *BeginRange, Expr *EndRange, + QualType RangeType, + VarDecl *BeginVar, + VarDecl *EndVar, + SourceLocation ColonLoc, + OverloadCandidateSet *CandidateSet, + ExprResult *BeginExpr, + ExprResult *EndExpr, + Sema::BeginEndFunction *BEF) { + DeclarationNameInfo BeginNameInfo( + &SemaRef.PP.getIdentifierTable().get("begin"), ColonLoc); + DeclarationNameInfo EndNameInfo(&SemaRef.PP.getIdentifierTable().get("end"), + ColonLoc); + + LookupResult BeginMemberLookup(SemaRef, BeginNameInfo, + Sema::LookupMemberName); + LookupResult EndMemberLookup(SemaRef, EndNameInfo, Sema::LookupMemberName); + + if (CXXRecordDecl *D = RangeType->getAsCXXRecordDecl()) { + // - if _RangeT is a class type, the unqualified-ids begin and end are + // looked up in the scope of class _RangeT as if by class member access + // lookup (3.4.5), and if either (or both) finds at least one + // declaration, begin-expr and end-expr are __range.begin() and + // __range.end(), respectively; + SemaRef.LookupQualifiedName(BeginMemberLookup, D); + SemaRef.LookupQualifiedName(EndMemberLookup, D); + + if (BeginMemberLookup.empty() != EndMemberLookup.empty()) { + SourceLocation RangeLoc = BeginVar->getLocation(); + *BEF = BeginMemberLookup.empty() ? Sema::BEF_end : Sema::BEF_begin; + + SemaRef.Diag(RangeLoc, diag::err_for_range_member_begin_end_mismatch) + << RangeLoc << BeginRange->getType() << *BEF; + return Sema::FRS_DiagnosticIssued; + } + } else { + // - otherwise, begin-expr and end-expr are begin(__range) and + // end(__range), respectively, where begin and end are looked up with + // argument-dependent lookup (3.4.2). For the purposes of this name + // lookup, namespace std is an associated namespace. + + } + + *BEF = Sema::BEF_begin; + Sema::ForRangeStatus RangeStatus = + SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, BeginVar, + Sema::BEF_begin, BeginNameInfo, + BeginMemberLookup, CandidateSet, + BeginRange, BeginExpr); + + if (RangeStatus != Sema::FRS_Success) + return RangeStatus; + if (FinishForRangeVarDecl(SemaRef, BeginVar, BeginExpr->get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(SemaRef, BeginExpr->get(), *BEF); + return Sema::FRS_DiagnosticIssued; + } + + *BEF = Sema::BEF_end; + RangeStatus = + SemaRef.BuildForRangeBeginEndCall(S, ColonLoc, ColonLoc, EndVar, + Sema::BEF_end, EndNameInfo, + EndMemberLookup, CandidateSet, + EndRange, EndExpr); + if (RangeStatus != Sema::FRS_Success) + return RangeStatus; + if (FinishForRangeVarDecl(SemaRef, EndVar, EndExpr->get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(SemaRef, EndExpr->get(), *BEF); + return Sema::FRS_DiagnosticIssued; + } + return Sema::FRS_Success; +} + +/// Speculatively attempt to dereference an invalid range expression. +/// If the attempt fails, this function will return a valid, null StmtResult +/// and emit no diagnostics. +static StmtResult RebuildForRangeWithDereference(Sema &SemaRef, Scope *S, + SourceLocation ForLoc, + Stmt *LoopVarDecl, + SourceLocation ColonLoc, + Expr *Range, + SourceLocation RangeLoc, + SourceLocation RParenLoc) { + // Determine whether we can rebuild the for-range statement with a + // dereferenced range expression. + ExprResult AdjustedRange; + { + Sema::SFINAETrap Trap(SemaRef); + + AdjustedRange = SemaRef.BuildUnaryOp(S, RangeLoc, UO_Deref, Range); + if (AdjustedRange.isInvalid()) + return StmtResult(); + + StmtResult SR = + SemaRef.ActOnCXXForRangeStmt(ForLoc, LoopVarDecl, ColonLoc, + AdjustedRange.get(), RParenLoc, + Sema::BFRK_Check); + if (SR.isInvalid()) + return StmtResult(); + } + + // The attempt to dereference worked well enough that it could produce a valid + // loop. Produce a fixit, and rebuild the loop with diagnostics enabled, in + // case there are any other (non-fatal) problems with it. + SemaRef.Diag(RangeLoc, diag::err_for_range_dereference) + << Range->getType() << FixItHint::CreateInsertion(RangeLoc, "*"); + return SemaRef.ActOnCXXForRangeStmt(ForLoc, LoopVarDecl, ColonLoc, + AdjustedRange.get(), RParenLoc, + Sema::BFRK_Rebuild); +} + +namespace { +/// RAII object to automatically invalidate a declaration if an error occurs. +struct InvalidateOnErrorScope { + InvalidateOnErrorScope(Sema &SemaRef, Decl *D, bool Enabled) + : Trap(SemaRef.Diags), D(D), Enabled(Enabled) {} + ~InvalidateOnErrorScope() { + if (Enabled && Trap.hasErrorOccurred()) + D->setInvalidDecl(); + } + + DiagnosticErrorTrap Trap; + Decl *D; + bool Enabled; +}; +} + +/// BuildCXXForRangeStmt - Build or instantiate a C++11 for-range statement. +StmtResult +Sema::BuildCXXForRangeStmt(SourceLocation ForLoc, SourceLocation ColonLoc, + Stmt *RangeDecl, Stmt *BeginEnd, Expr *Cond, + Expr *Inc, Stmt *LoopVarDecl, + SourceLocation RParenLoc, BuildForRangeKind Kind) { + Scope *S = getCurScope(); + + DeclStmt *RangeDS = cast<DeclStmt>(RangeDecl); + VarDecl *RangeVar = cast<VarDecl>(RangeDS->getSingleDecl()); + QualType RangeVarType = RangeVar->getType(); + + DeclStmt *LoopVarDS = cast<DeclStmt>(LoopVarDecl); + VarDecl *LoopVar = cast<VarDecl>(LoopVarDS->getSingleDecl()); + + // If we hit any errors, mark the loop variable as invalid if its type + // contains 'auto'. + InvalidateOnErrorScope Invalidate(*this, LoopVar, + LoopVar->getType()->isUndeducedType()); + + StmtResult BeginEndDecl = BeginEnd; + ExprResult NotEqExpr = Cond, IncrExpr = Inc; + + if (RangeVarType->isDependentType()) { + // The range is implicitly used as a placeholder when it is dependent. + RangeVar->markUsed(Context); + + // Deduce any 'auto's in the loop variable as 'DependentTy'. We'll fill + // them in properly when we instantiate the loop. + if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) + LoopVar->setType(SubstAutoType(LoopVar->getType(), Context.DependentTy)); + } else if (!BeginEndDecl.get()) { + SourceLocation RangeLoc = RangeVar->getLocation(); + + const QualType RangeVarNonRefType = RangeVarType.getNonReferenceType(); + + ExprResult BeginRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, + VK_LValue, ColonLoc); + if (BeginRangeRef.isInvalid()) + return StmtError(); + + ExprResult EndRangeRef = BuildDeclRefExpr(RangeVar, RangeVarNonRefType, + VK_LValue, ColonLoc); + if (EndRangeRef.isInvalid()) + return StmtError(); + + QualType AutoType = Context.getAutoDeductType(); + Expr *Range = RangeVar->getInit(); + if (!Range) + return StmtError(); + QualType RangeType = Range->getType(); + + if (RequireCompleteType(RangeLoc, RangeType, + diag::err_for_range_incomplete_type)) + return StmtError(); + + // Build auto __begin = begin-expr, __end = end-expr. + VarDecl *BeginVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, + "__begin"); + VarDecl *EndVar = BuildForRangeVarDecl(*this, ColonLoc, AutoType, + "__end"); + + // Build begin-expr and end-expr and attach to __begin and __end variables. + ExprResult BeginExpr, EndExpr; + if (const ArrayType *UnqAT = RangeType->getAsArrayTypeUnsafe()) { + // - if _RangeT is an array type, begin-expr and end-expr are __range and + // __range + __bound, respectively, where __bound is the array bound. If + // _RangeT is an array of unknown size or an array of incomplete type, + // the program is ill-formed; + + // begin-expr is __range. + BeginExpr = BeginRangeRef; + if (FinishForRangeVarDecl(*this, BeginVar, BeginRangeRef.get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + return StmtError(); + } + + // Find the array bound. + ExprResult BoundExpr; + if (const ConstantArrayType *CAT = dyn_cast<ConstantArrayType>(UnqAT)) + BoundExpr = Owned(IntegerLiteral::Create(Context, CAT->getSize(), + Context.getPointerDiffType(), + RangeLoc)); + else if (const VariableArrayType *VAT = + dyn_cast<VariableArrayType>(UnqAT)) + BoundExpr = VAT->getSizeExpr(); + else { + // Can't be a DependentSizedArrayType or an IncompleteArrayType since + // UnqAT is not incomplete and Range is not type-dependent. + llvm_unreachable("Unexpected array type in for-range"); + } + + // end-expr is __range + __bound. + EndExpr = ActOnBinOp(S, ColonLoc, tok::plus, EndRangeRef.get(), + BoundExpr.get()); + if (EndExpr.isInvalid()) + return StmtError(); + if (FinishForRangeVarDecl(*this, EndVar, EndExpr.get(), ColonLoc, + diag::err_for_range_iter_deduction_failure)) { + NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); + return StmtError(); + } + } else { + OverloadCandidateSet CandidateSet(RangeLoc); + Sema::BeginEndFunction BEFFailure; + ForRangeStatus RangeStatus = + BuildNonArrayForRange(*this, S, BeginRangeRef.get(), + EndRangeRef.get(), RangeType, + BeginVar, EndVar, ColonLoc, &CandidateSet, + &BeginExpr, &EndExpr, &BEFFailure); + + if (Kind == BFRK_Build && RangeStatus == FRS_NoViableFunction && + BEFFailure == BEF_begin) { + // If the range is being built from an array parameter, emit a + // a diagnostic that it is being treated as a pointer. + if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Range)) { + if (ParmVarDecl *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) { + QualType ArrayTy = PVD->getOriginalType(); + QualType PointerTy = PVD->getType(); + if (PointerTy->isPointerType() && ArrayTy->isArrayType()) { + Diag(Range->getLocStart(), diag::err_range_on_array_parameter) + << RangeLoc << PVD << ArrayTy << PointerTy; + Diag(PVD->getLocation(), diag::note_declared_at); + return StmtError(); + } + } + } + + // If building the range failed, try dereferencing the range expression + // unless a diagnostic was issued or the end function is problematic. + StmtResult SR = RebuildForRangeWithDereference(*this, S, ForLoc, + LoopVarDecl, ColonLoc, + Range, RangeLoc, + RParenLoc); + if (SR.isInvalid() || SR.isUsable()) + return SR; + } + + // Otherwise, emit diagnostics if we haven't already. + if (RangeStatus == FRS_NoViableFunction) { + Expr *Range = BEFFailure ? EndRangeRef.get() : BeginRangeRef.get(); + Diag(Range->getLocStart(), diag::err_for_range_invalid) + << RangeLoc << Range->getType() << BEFFailure; + CandidateSet.NoteCandidates(*this, OCD_AllCandidates, Range); + } + // Return an error if no fix was discovered. + if (RangeStatus != FRS_Success) + return StmtError(); + } + + assert(!BeginExpr.isInvalid() && !EndExpr.isInvalid() && + "invalid range expression in for loop"); + + // C++11 [dcl.spec.auto]p7: BeginType and EndType must be the same. + QualType BeginType = BeginVar->getType(), EndType = EndVar->getType(); + if (!Context.hasSameType(BeginType, EndType)) { + Diag(RangeLoc, diag::err_for_range_begin_end_types_differ) + << BeginType << EndType; + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); + } + + Decl *BeginEndDecls[] = { BeginVar, EndVar }; + // Claim the type doesn't contain auto: we've already done the checking. + DeclGroupPtrTy BeginEndGroup = + BuildDeclaratorGroup(llvm::MutableArrayRef<Decl *>(BeginEndDecls, 2), + /*TypeMayContainAuto=*/ false); + BeginEndDecl = ActOnDeclStmt(BeginEndGroup, ColonLoc, ColonLoc); + + const QualType BeginRefNonRefType = BeginType.getNonReferenceType(); + ExprResult BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, + VK_LValue, ColonLoc); + if (BeginRef.isInvalid()) + return StmtError(); + + ExprResult EndRef = BuildDeclRefExpr(EndVar, EndType.getNonReferenceType(), + VK_LValue, ColonLoc); + if (EndRef.isInvalid()) + return StmtError(); + + // Build and check __begin != __end expression. + NotEqExpr = ActOnBinOp(S, ColonLoc, tok::exclaimequal, + BeginRef.get(), EndRef.get()); + NotEqExpr = ActOnBooleanCondition(S, ColonLoc, NotEqExpr.get()); + NotEqExpr = ActOnFinishFullExpr(NotEqExpr.get()); + if (NotEqExpr.isInvalid()) { + Diag(RangeLoc, diag::note_for_range_invalid_iterator) + << RangeLoc << 0 << BeginRangeRef.get()->getType(); + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + if (!Context.hasSameType(BeginType, EndType)) + NoteForRangeBeginEndFunction(*this, EndExpr.get(), BEF_end); + return StmtError(); + } + + // Build and check ++__begin expression. + BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, + VK_LValue, ColonLoc); + if (BeginRef.isInvalid()) + return StmtError(); + + IncrExpr = ActOnUnaryOp(S, ColonLoc, tok::plusplus, BeginRef.get()); + IncrExpr = ActOnFinishFullExpr(IncrExpr.get()); + if (IncrExpr.isInvalid()) { + Diag(RangeLoc, diag::note_for_range_invalid_iterator) + << RangeLoc << 2 << BeginRangeRef.get()->getType() ; + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + return StmtError(); + } + + // Build and check *__begin expression. + BeginRef = BuildDeclRefExpr(BeginVar, BeginRefNonRefType, + VK_LValue, ColonLoc); + if (BeginRef.isInvalid()) + return StmtError(); + + ExprResult DerefExpr = ActOnUnaryOp(S, ColonLoc, tok::star, BeginRef.get()); + if (DerefExpr.isInvalid()) { + Diag(RangeLoc, diag::note_for_range_invalid_iterator) + << RangeLoc << 1 << BeginRangeRef.get()->getType(); + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + return StmtError(); + } + + // Attach *__begin as initializer for VD. Don't touch it if we're just + // trying to determine whether this would be a valid range. + if (!LoopVar->isInvalidDecl() && Kind != BFRK_Check) { + AddInitializerToDecl(LoopVar, DerefExpr.get(), /*DirectInit=*/false, + /*TypeMayContainAuto=*/true); + if (LoopVar->isInvalidDecl()) + NoteForRangeBeginEndFunction(*this, BeginExpr.get(), BEF_begin); + } + } + + // Don't bother to actually allocate the result if we're just trying to + // determine whether it would be valid. + if (Kind == BFRK_Check) + return StmtResult(); + + return Owned(new (Context) CXXForRangeStmt(RangeDS, + cast_or_null<DeclStmt>(BeginEndDecl.get()), + NotEqExpr.take(), IncrExpr.take(), + LoopVarDS, /*Body=*/0, ForLoc, + ColonLoc, RParenLoc)); +} + +/// FinishObjCForCollectionStmt - Attach the body to a objective-C foreach +/// statement. +StmtResult Sema::FinishObjCForCollectionStmt(Stmt *S, Stmt *B) { + if (!S || !B) + return StmtError(); + ObjCForCollectionStmt * ForStmt = cast<ObjCForCollectionStmt>(S); + + ForStmt->setBody(B); + return S; +} + +/// FinishCXXForRangeStmt - Attach the body to a C++0x for-range statement. +/// This is a separate step from ActOnCXXForRangeStmt because analysis of the +/// body cannot be performed until after the type of the range variable is +/// determined. +StmtResult Sema::FinishCXXForRangeStmt(Stmt *S, Stmt *B) { + if (!S || !B) + return StmtError(); + + if (isa<ObjCForCollectionStmt>(S)) + return FinishObjCForCollectionStmt(S, B); + + CXXForRangeStmt *ForStmt = cast<CXXForRangeStmt>(S); + ForStmt->setBody(B); + + DiagnoseEmptyStmtBody(ForStmt->getRParenLoc(), B, + diag::warn_empty_range_based_for_body); + + return S; +} + +StmtResult Sema::ActOnGotoStmt(SourceLocation GotoLoc, + SourceLocation LabelLoc, + LabelDecl *TheDecl) { + getCurFunction()->setHasBranchIntoScope(); + TheDecl->markUsed(Context); + return Owned(new (Context) GotoStmt(TheDecl, GotoLoc, LabelLoc)); +} + +StmtResult +Sema::ActOnIndirectGotoStmt(SourceLocation GotoLoc, SourceLocation StarLoc, + Expr *E) { + // Convert operand to void* + if (!E->isTypeDependent()) { + QualType ETy = E->getType(); + QualType DestTy = Context.getPointerType(Context.VoidTy.withConst()); + ExprResult ExprRes = Owned(E); + AssignConvertType ConvTy = + CheckSingleAssignmentConstraints(DestTy, ExprRes); + if (ExprRes.isInvalid()) + return StmtError(); + E = ExprRes.take(); + if (DiagnoseAssignmentResult(ConvTy, StarLoc, DestTy, ETy, E, AA_Passing)) + return StmtError(); + } + + ExprResult ExprRes = ActOnFinishFullExpr(E); + if (ExprRes.isInvalid()) + return StmtError(); + E = ExprRes.take(); + + getCurFunction()->setHasIndirectGoto(); + + return Owned(new (Context) IndirectGotoStmt(GotoLoc, StarLoc, E)); +} + +StmtResult +Sema::ActOnContinueStmt(SourceLocation ContinueLoc, Scope *CurScope) { + Scope *S = CurScope->getContinueParent(); + if (!S) { + // C99 6.8.6.2p1: A break shall appear only in or as a loop body. + return StmtError(Diag(ContinueLoc, diag::err_continue_not_in_loop)); + } + + return Owned(new (Context) ContinueStmt(ContinueLoc)); +} + +StmtResult +Sema::ActOnBreakStmt(SourceLocation BreakLoc, Scope *CurScope) { + Scope *S = CurScope->getBreakParent(); + if (!S) { + // C99 6.8.6.3p1: A break shall appear only in or as a switch/loop body. + return StmtError(Diag(BreakLoc, diag::err_break_not_in_loop_or_switch)); + } + + return Owned(new (Context) BreakStmt(BreakLoc)); +} + +/// \brief Determine whether the given expression is a candidate for +/// copy elision in either a return statement or a throw expression. +/// +/// \param ReturnType If we're determining the copy elision candidate for +/// a return statement, this is the return type of the function. If we're +/// determining the copy elision candidate for a throw expression, this will +/// be a NULL type. +/// +/// \param E The expression being returned from the function or block, or +/// being thrown. +/// +/// \param AllowFunctionParameter Whether we allow function parameters to +/// be considered NRVO candidates. C++ prohibits this for NRVO itself, but +/// we re-use this logic to determine whether we should try to move as part of +/// a return or throw (which does allow function parameters). +/// +/// \returns The NRVO candidate variable, if the return statement may use the +/// NRVO, or NULL if there is no such candidate. +const VarDecl *Sema::getCopyElisionCandidate(QualType ReturnType, + Expr *E, + bool AllowFunctionParameter) { + QualType ExprType = E->getType(); + // - in a return statement in a function with ... + // ... a class return type ... + if (!ReturnType.isNull()) { + if (!ReturnType->isRecordType()) + return 0; + // ... the same cv-unqualified type as the function return type ... + if (!Context.hasSameUnqualifiedType(ReturnType, ExprType)) + return 0; + } + + // ... the expression is the name of a non-volatile automatic object + // (other than a function or catch-clause parameter)) ... + const DeclRefExpr *DR = dyn_cast<DeclRefExpr>(E->IgnoreParens()); + if (!DR || DR->refersToEnclosingLocal()) + return 0; + const VarDecl *VD = dyn_cast<VarDecl>(DR->getDecl()); + if (!VD) + return 0; + + // ...object (other than a function or catch-clause parameter)... + if (VD->getKind() != Decl::Var && + !(AllowFunctionParameter && VD->getKind() == Decl::ParmVar)) + return 0; + if (VD->isExceptionVariable()) return 0; + + // ...automatic... + if (!VD->hasLocalStorage()) return 0; + + // ...non-volatile... + if (VD->getType().isVolatileQualified()) return 0; + if (VD->getType()->isReferenceType()) return 0; + + // __block variables can't be allocated in a way that permits NRVO. + if (VD->hasAttr<BlocksAttr>()) return 0; + + // Variables with higher required alignment than their type's ABI + // alignment cannot use NRVO. + if (VD->hasAttr<AlignedAttr>() && + Context.getDeclAlign(VD) > Context.getTypeAlignInChars(VD->getType())) + return 0; + + return VD; +} + +/// \brief Perform the initialization of a potentially-movable value, which +/// is the result of return value. +/// +/// This routine implements C++0x [class.copy]p33, which attempts to treat +/// returned lvalues as rvalues in certain cases (to prefer move construction), +/// then falls back to treating them as lvalues if that failed. +ExprResult +Sema::PerformMoveOrCopyInitialization(const InitializedEntity &Entity, + const VarDecl *NRVOCandidate, + QualType ResultType, + Expr *Value, + bool AllowNRVO) { + // C++0x [class.copy]p33: + // When the criteria for elision of a copy operation are met or would + // be met save for the fact that the source object is a function + // parameter, and the object to be copied is designated by an lvalue, + // overload resolution to select the constructor for the copy is first + // performed as if the object were designated by an rvalue. + ExprResult Res = ExprError(); + if (AllowNRVO && + (NRVOCandidate || getCopyElisionCandidate(ResultType, Value, true))) { + ImplicitCastExpr AsRvalue(ImplicitCastExpr::OnStack, + Value->getType(), CK_NoOp, Value, VK_XValue); + + Expr *InitExpr = &AsRvalue; + InitializationKind Kind + = InitializationKind::CreateCopy(Value->getLocStart(), + Value->getLocStart()); + InitializationSequence Seq(*this, Entity, Kind, InitExpr); + + // [...] If overload resolution fails, or if the type of the first + // parameter of the selected constructor is not an rvalue reference + // to the object's type (possibly cv-qualified), overload resolution + // is performed again, considering the object as an lvalue. + if (Seq) { + for (InitializationSequence::step_iterator Step = Seq.step_begin(), + StepEnd = Seq.step_end(); + Step != StepEnd; ++Step) { + if (Step->Kind != InitializationSequence::SK_ConstructorInitialization) + continue; + + CXXConstructorDecl *Constructor + = cast<CXXConstructorDecl>(Step->Function.Function); + + const RValueReferenceType *RRefType + = Constructor->getParamDecl(0)->getType() + ->getAs<RValueReferenceType>(); + + // If we don't meet the criteria, break out now. + if (!RRefType || + !Context.hasSameUnqualifiedType(RRefType->getPointeeType(), + Context.getTypeDeclType(Constructor->getParent()))) + break; + + // Promote "AsRvalue" to the heap, since we now need this + // expression node to persist. + Value = ImplicitCastExpr::Create(Context, Value->getType(), + CK_NoOp, Value, 0, VK_XValue); + + // Complete type-checking the initialization of the return type + // using the constructor we found. + Res = Seq.Perform(*this, Entity, Kind, Value); + } + } + } + + // Either we didn't meet the criteria for treating an lvalue as an rvalue, + // above, or overload resolution failed. Either way, we need to try + // (again) now with the return value expression as written. + if (Res.isInvalid()) + Res = PerformCopyInitialization(Entity, SourceLocation(), Value); + + return Res; +} + +/// \brief Determine whether the declared return type of the specified function +/// contains 'auto'. +static bool hasDeducedReturnType(FunctionDecl *FD) { + const FunctionProtoType *FPT = + FD->getTypeSourceInfo()->getType()->castAs<FunctionProtoType>(); + return FPT->getResultType()->isUndeducedType(); +} + +/// ActOnCapScopeReturnStmt - Utility routine to type-check return statements +/// for capturing scopes. +/// +StmtResult +Sema::ActOnCapScopeReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { + // If this is the first return we've seen, infer the return type. + // [expr.prim.lambda]p4 in C++11; block literals follow the same rules. + CapturingScopeInfo *CurCap = cast<CapturingScopeInfo>(getCurFunction()); + QualType FnRetType = CurCap->ReturnType; + LambdaScopeInfo *CurLambda = dyn_cast<LambdaScopeInfo>(CurCap); + + if (CurLambda && hasDeducedReturnType(CurLambda->CallOperator)) { + // In C++1y, the return type may involve 'auto'. + // FIXME: Blocks might have a return type of 'auto' explicitly specified. + FunctionDecl *FD = CurLambda->CallOperator; + if (CurCap->ReturnType.isNull()) + CurCap->ReturnType = FD->getResultType(); + + AutoType *AT = CurCap->ReturnType->getContainedAutoType(); + assert(AT && "lost auto type from lambda return type"); + if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) { + FD->setInvalidDecl(); + return StmtError(); + } + CurCap->ReturnType = FnRetType = FD->getResultType(); + } else if (CurCap->HasImplicitReturnType) { + // For blocks/lambdas with implicit return types, we check each return + // statement individually, and deduce the common return type when the block + // or lambda is completed. + // FIXME: Fold this into the 'auto' codepath above. + if (RetValExp && !isa<InitListExpr>(RetValExp)) { + ExprResult Result = DefaultFunctionArrayLvalueConversion(RetValExp); + if (Result.isInvalid()) + return StmtError(); + RetValExp = Result.take(); + + if (!CurContext->isDependentContext()) + FnRetType = RetValExp->getType(); + else + FnRetType = CurCap->ReturnType = Context.DependentTy; + } else { + if (RetValExp) { + // C++11 [expr.lambda.prim]p4 bans inferring the result from an + // initializer list, because it is not an expression (even + // though we represent it as one). We still deduce 'void'. + Diag(ReturnLoc, diag::err_lambda_return_init_list) + << RetValExp->getSourceRange(); + } + + FnRetType = Context.VoidTy; + } + + // Although we'll properly infer the type of the block once it's completed, + // make sure we provide a return type now for better error recovery. + if (CurCap->ReturnType.isNull()) + CurCap->ReturnType = FnRetType; + } + assert(!FnRetType.isNull()); + + if (BlockScopeInfo *CurBlock = dyn_cast<BlockScopeInfo>(CurCap)) { + if (CurBlock->FunctionType->getAs<FunctionType>()->getNoReturnAttr()) { + Diag(ReturnLoc, diag::err_noreturn_block_has_return_expr); + return StmtError(); + } + } else if (CapturedRegionScopeInfo *CurRegion = + dyn_cast<CapturedRegionScopeInfo>(CurCap)) { + Diag(ReturnLoc, diag::err_return_in_captured_stmt) << CurRegion->getRegionName(); + return StmtError(); + } else { + assert(CurLambda && "unknown kind of captured scope"); + if (CurLambda->CallOperator->getType()->getAs<FunctionType>() + ->getNoReturnAttr()) { + Diag(ReturnLoc, diag::err_noreturn_lambda_has_return_expr); + return StmtError(); + } + } + + // Otherwise, verify that this result type matches the previous one. We are + // pickier with blocks than for normal functions because we don't have GCC + // compatibility to worry about here. + const VarDecl *NRVOCandidate = 0; + if (FnRetType->isDependentType()) { + // Delay processing for now. TODO: there are lots of dependent + // types we can conclusively prove aren't void. + } else if (FnRetType->isVoidType()) { + if (RetValExp && !isa<InitListExpr>(RetValExp) && + !(getLangOpts().CPlusPlus && + (RetValExp->isTypeDependent() || + RetValExp->getType()->isVoidType()))) { + if (!getLangOpts().CPlusPlus && + RetValExp->getType()->isVoidType()) + Diag(ReturnLoc, diag::ext_return_has_void_expr) << "literal" << 2; + else { + Diag(ReturnLoc, diag::err_return_block_has_expr); + RetValExp = 0; + } + } + } else if (!RetValExp) { + return StmtError(Diag(ReturnLoc, diag::err_block_return_missing_expr)); + } else if (!RetValExp->isTypeDependent()) { + // we have a non-void block with an expression, continue checking + + // C99 6.8.6.4p3(136): The return statement is not an assignment. The + // overlap restriction of subclause 6.5.16.1 does not apply to the case of + // function return. + + // In C++ the return statement is handled via a copy initialization. + // the C version of which boils down to CheckSingleAssignmentConstraints. + NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); + InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, + FnRetType, + NRVOCandidate != 0); + ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, + FnRetType, RetValExp); + if (Res.isInvalid()) { + // FIXME: Cleanup temporaries here, anyway? + return StmtError(); + } + RetValExp = Res.take(); + CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); + } + + if (RetValExp) { + ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.take(); + } + ReturnStmt *Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, + NRVOCandidate); + + // If we need to check for the named return value optimization, + // or if we need to infer the return type, + // save the return statement in our scope for later processing. + if (CurCap->HasImplicitReturnType || + (getLangOpts().CPlusPlus && FnRetType->isRecordType() && + !CurContext->isDependentContext())) + FunctionScopes.back()->Returns.push_back(Result); + + return Owned(Result); +} + +/// Deduce the return type for a function from a returned expression, per +/// C++1y [dcl.spec.auto]p6. +bool Sema::DeduceFunctionTypeFromReturnExpr(FunctionDecl *FD, + SourceLocation ReturnLoc, + Expr *&RetExpr, + AutoType *AT) { + TypeLoc OrigResultType = FD->getTypeSourceInfo()->getTypeLoc(). + IgnoreParens().castAs<FunctionProtoTypeLoc>().getResultLoc(); + QualType Deduced; + + if (RetExpr && isa<InitListExpr>(RetExpr)) { + // If the deduction is for a return statement and the initializer is + // a braced-init-list, the program is ill-formed. + Diag(RetExpr->getExprLoc(), + getCurLambda() ? diag::err_lambda_return_init_list + : diag::err_auto_fn_return_init_list) + << RetExpr->getSourceRange(); + return true; + } + + if (FD->isDependentContext()) { + // C++1y [dcl.spec.auto]p12: + // Return type deduction [...] occurs when the definition is + // instantiated even if the function body contains a return + // statement with a non-type-dependent operand. + assert(AT->isDeduced() && "should have deduced to dependent type"); + return false; + } else if (RetExpr) { + // If the deduction is for a return statement and the initializer is + // a braced-init-list, the program is ill-formed. + if (isa<InitListExpr>(RetExpr)) { + Diag(RetExpr->getExprLoc(), diag::err_auto_fn_return_init_list); + return true; + } + + // Otherwise, [...] deduce a value for U using the rules of template + // argument deduction. + DeduceAutoResult DAR = DeduceAutoType(OrigResultType, RetExpr, Deduced); + + if (DAR == DAR_Failed && !FD->isInvalidDecl()) + Diag(RetExpr->getExprLoc(), diag::err_auto_fn_deduction_failure) + << OrigResultType.getType() << RetExpr->getType(); + + if (DAR != DAR_Succeeded) + return true; + } else { + // In the case of a return with no operand, the initializer is considered + // to be void(). + // + // Deduction here can only succeed if the return type is exactly 'cv auto' + // or 'decltype(auto)', so just check for that case directly. + if (!OrigResultType.getType()->getAs<AutoType>()) { + Diag(ReturnLoc, diag::err_auto_fn_return_void_but_not_auto) + << OrigResultType.getType(); + return true; + } + // We always deduce U = void in this case. + Deduced = SubstAutoType(OrigResultType.getType(), Context.VoidTy); + if (Deduced.isNull()) + return true; + } + + // If a function with a declared return type that contains a placeholder type + // has multiple return statements, the return type is deduced for each return + // statement. [...] if the type deduced is not the same in each deduction, + // the program is ill-formed. + if (AT->isDeduced() && !FD->isInvalidDecl()) { + AutoType *NewAT = Deduced->getContainedAutoType(); + if (!FD->isDependentContext() && + !Context.hasSameType(AT->getDeducedType(), NewAT->getDeducedType())) { + const LambdaScopeInfo *LambdaSI = getCurLambda(); + if (LambdaSI && LambdaSI->HasImplicitReturnType) { + Diag(ReturnLoc, diag::err_typecheck_missing_return_type_incompatible) + << NewAT->getDeducedType() << AT->getDeducedType() + << true /*IsLambda*/; + } else { + Diag(ReturnLoc, diag::err_auto_fn_different_deductions) + << (AT->isDecltypeAuto() ? 1 : 0) + << NewAT->getDeducedType() << AT->getDeducedType(); + } + return true; + } + } else if (!FD->isInvalidDecl()) { + // Update all declarations of the function to have the deduced return type. + Context.adjustDeducedFunctionResultType(FD, Deduced); + } + + return false; +} + +StmtResult +Sema::ActOnReturnStmt(SourceLocation ReturnLoc, Expr *RetValExp) { + // Check for unexpanded parameter packs. + if (RetValExp && DiagnoseUnexpandedParameterPack(RetValExp)) + return StmtError(); + + if (isa<CapturingScopeInfo>(getCurFunction())) + return ActOnCapScopeReturnStmt(ReturnLoc, RetValExp); + + QualType FnRetType; + QualType RelatedRetType; + if (const FunctionDecl *FD = getCurFunctionDecl()) { + FnRetType = FD->getResultType(); + if (FD->isNoReturn()) + Diag(ReturnLoc, diag::warn_noreturn_function_has_return_expr) + << FD->getDeclName(); + } else if (ObjCMethodDecl *MD = getCurMethodDecl()) { + FnRetType = MD->getResultType(); + if (MD->hasRelatedResultType() && MD->getClassInterface()) { + // In the implementation of a method with a related return type, the + // type used to type-check the validity of return statements within the + // method body is a pointer to the type of the class being implemented. + RelatedRetType = Context.getObjCInterfaceType(MD->getClassInterface()); + RelatedRetType = Context.getObjCObjectPointerType(RelatedRetType); + } + } else // If we don't have a function/method context, bail. + return StmtError(); + + // FIXME: Add a flag to the ScopeInfo to indicate whether we're performing + // deduction. + if (getLangOpts().CPlusPlus1y) { + if (AutoType *AT = FnRetType->getContainedAutoType()) { + FunctionDecl *FD = cast<FunctionDecl>(CurContext); + if (DeduceFunctionTypeFromReturnExpr(FD, ReturnLoc, RetValExp, AT)) { + FD->setInvalidDecl(); + return StmtError(); + } else { + FnRetType = FD->getResultType(); + } + } + } + + bool HasDependentReturnType = FnRetType->isDependentType(); + + ReturnStmt *Result = 0; + if (FnRetType->isVoidType()) { + if (RetValExp) { + if (isa<InitListExpr>(RetValExp)) { + // We simply never allow init lists as the return value of void + // functions. This is compatible because this was never allowed before, + // so there's no legacy code to deal with. + NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); + int FunctionKind = 0; + if (isa<ObjCMethodDecl>(CurDecl)) + FunctionKind = 1; + else if (isa<CXXConstructorDecl>(CurDecl)) + FunctionKind = 2; + else if (isa<CXXDestructorDecl>(CurDecl)) + FunctionKind = 3; + + Diag(ReturnLoc, diag::err_return_init_list) + << CurDecl->getDeclName() << FunctionKind + << RetValExp->getSourceRange(); + + // Drop the expression. + RetValExp = 0; + } else if (!RetValExp->isTypeDependent()) { + // C99 6.8.6.4p1 (ext_ since GCC warns) + unsigned D = diag::ext_return_has_expr; + if (RetValExp->getType()->isVoidType()) + D = diag::ext_return_has_void_expr; + else { + ExprResult Result = Owned(RetValExp); + Result = IgnoredValueConversions(Result.take()); + if (Result.isInvalid()) + return StmtError(); + RetValExp = Result.take(); + RetValExp = ImpCastExprToType(RetValExp, + Context.VoidTy, CK_ToVoid).take(); + } + + // return (some void expression); is legal in C++. + if (D != diag::ext_return_has_void_expr || + !getLangOpts().CPlusPlus) { + NamedDecl *CurDecl = getCurFunctionOrMethodDecl(); + + int FunctionKind = 0; + if (isa<ObjCMethodDecl>(CurDecl)) + FunctionKind = 1; + else if (isa<CXXConstructorDecl>(CurDecl)) + FunctionKind = 2; + else if (isa<CXXDestructorDecl>(CurDecl)) + FunctionKind = 3; + + Diag(ReturnLoc, D) + << CurDecl->getDeclName() << FunctionKind + << RetValExp->getSourceRange(); + } + } + + if (RetValExp) { + ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.take(); + } + } + + Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, 0); + } else if (!RetValExp && !HasDependentReturnType) { + unsigned DiagID = diag::warn_return_missing_expr; // C90 6.6.6.4p4 + // C99 6.8.6.4p1 (ext_ since GCC warns) + if (getLangOpts().C99) DiagID = diag::ext_return_missing_expr; + + if (FunctionDecl *FD = getCurFunctionDecl()) + Diag(ReturnLoc, DiagID) << FD->getIdentifier() << 0/*fn*/; + else + Diag(ReturnLoc, DiagID) << getCurMethodDecl()->getDeclName() << 1/*meth*/; + Result = new (Context) ReturnStmt(ReturnLoc); + } else { + assert(RetValExp || HasDependentReturnType); + const VarDecl *NRVOCandidate = 0; + if (!HasDependentReturnType && !RetValExp->isTypeDependent()) { + // we have a non-void function with an expression, continue checking + + QualType RetType = (RelatedRetType.isNull() ? FnRetType : RelatedRetType); + + // C99 6.8.6.4p3(136): The return statement is not an assignment. The + // overlap restriction of subclause 6.5.16.1 does not apply to the case of + // function return. + + // In C++ the return statement is handled via a copy initialization, + // the C version of which boils down to CheckSingleAssignmentConstraints. + NRVOCandidate = getCopyElisionCandidate(FnRetType, RetValExp, false); + InitializedEntity Entity = InitializedEntity::InitializeResult(ReturnLoc, + RetType, + NRVOCandidate != 0); + ExprResult Res = PerformMoveOrCopyInitialization(Entity, NRVOCandidate, + RetType, RetValExp); + if (Res.isInvalid()) { + // FIXME: Clean up temporaries here anyway? + return StmtError(); + } + RetValExp = Res.takeAs<Expr>(); + + // If we have a related result type, we need to implicitly + // convert back to the formal result type. We can't pretend to + // initialize the result again --- we might end double-retaining + // --- so instead we initialize a notional temporary. + if (!RelatedRetType.isNull()) { + Entity = InitializedEntity::InitializeRelatedResult(getCurMethodDecl(), + FnRetType); + Res = PerformCopyInitialization(Entity, ReturnLoc, RetValExp); + if (Res.isInvalid()) { + // FIXME: Clean up temporaries here anyway? + return StmtError(); + } + RetValExp = Res.takeAs<Expr>(); + } + + CheckReturnStackAddr(RetValExp, FnRetType, ReturnLoc); + } + + if (RetValExp) { + ExprResult ER = ActOnFinishFullExpr(RetValExp, ReturnLoc); + if (ER.isInvalid()) + return StmtError(); + RetValExp = ER.take(); + } + Result = new (Context) ReturnStmt(ReturnLoc, RetValExp, NRVOCandidate); + } + + // If we need to check for the named return value optimization, save the + // return statement in our scope for later processing. + if (getLangOpts().CPlusPlus && FnRetType->isRecordType() && + !CurContext->isDependentContext()) + FunctionScopes.back()->Returns.push_back(Result); + + return Owned(Result); +} + +StmtResult +Sema::ActOnObjCAtCatchStmt(SourceLocation AtLoc, + SourceLocation RParen, Decl *Parm, + Stmt *Body) { + VarDecl *Var = cast_or_null<VarDecl>(Parm); + if (Var && Var->isInvalidDecl()) + return StmtError(); + + return Owned(new (Context) ObjCAtCatchStmt(AtLoc, RParen, Var, Body)); +} + +StmtResult +Sema::ActOnObjCAtFinallyStmt(SourceLocation AtLoc, Stmt *Body) { + return Owned(new (Context) ObjCAtFinallyStmt(AtLoc, Body)); +} + +StmtResult +Sema::ActOnObjCAtTryStmt(SourceLocation AtLoc, Stmt *Try, + MultiStmtArg CatchStmts, Stmt *Finally) { + if (!getLangOpts().ObjCExceptions) + Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@try"; + + getCurFunction()->setHasBranchProtectedScope(); + unsigned NumCatchStmts = CatchStmts.size(); + return Owned(ObjCAtTryStmt::Create(Context, AtLoc, Try, + CatchStmts.data(), + NumCatchStmts, + Finally)); +} + +StmtResult Sema::BuildObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw) { + if (Throw) { + ExprResult Result = DefaultLvalueConversion(Throw); + if (Result.isInvalid()) + return StmtError(); + + Result = ActOnFinishFullExpr(Result.take()); + if (Result.isInvalid()) + return StmtError(); + Throw = Result.take(); + + QualType ThrowType = Throw->getType(); + // Make sure the expression type is an ObjC pointer or "void *". + if (!ThrowType->isDependentType() && + !ThrowType->isObjCObjectPointerType()) { + const PointerType *PT = ThrowType->getAs<PointerType>(); + if (!PT || !PT->getPointeeType()->isVoidType()) + return StmtError(Diag(AtLoc, diag::error_objc_throw_expects_object) + << Throw->getType() << Throw->getSourceRange()); + } + } + + return Owned(new (Context) ObjCAtThrowStmt(AtLoc, Throw)); +} + +StmtResult +Sema::ActOnObjCAtThrowStmt(SourceLocation AtLoc, Expr *Throw, + Scope *CurScope) { + if (!getLangOpts().ObjCExceptions) + Diag(AtLoc, diag::err_objc_exceptions_disabled) << "@throw"; + + if (!Throw) { + // @throw without an expression designates a rethrow (which much occur + // in the context of an @catch clause). + Scope *AtCatchParent = CurScope; + while (AtCatchParent && !AtCatchParent->isAtCatchScope()) + AtCatchParent = AtCatchParent->getParent(); + if (!AtCatchParent) + return StmtError(Diag(AtLoc, diag::error_rethrow_used_outside_catch)); + } + return BuildObjCAtThrowStmt(AtLoc, Throw); +} + +ExprResult +Sema::ActOnObjCAtSynchronizedOperand(SourceLocation atLoc, Expr *operand) { + ExprResult result = DefaultLvalueConversion(operand); + if (result.isInvalid()) + return ExprError(); + operand = result.take(); + + // Make sure the expression type is an ObjC pointer or "void *". + QualType type = operand->getType(); + if (!type->isDependentType() && + !type->isObjCObjectPointerType()) { + const PointerType *pointerType = type->getAs<PointerType>(); + if (!pointerType || !pointerType->getPointeeType()->isVoidType()) + return Diag(atLoc, diag::error_objc_synchronized_expects_object) + << type << operand->getSourceRange(); + } + + // The operand to @synchronized is a full-expression. + return ActOnFinishFullExpr(operand); +} + +StmtResult +Sema::ActOnObjCAtSynchronizedStmt(SourceLocation AtLoc, Expr *SyncExpr, + Stmt *SyncBody) { + // We can't jump into or indirect-jump out of a @synchronized block. + getCurFunction()->setHasBranchProtectedScope(); + return Owned(new (Context) ObjCAtSynchronizedStmt(AtLoc, SyncExpr, SyncBody)); +} + +/// ActOnCXXCatchBlock - Takes an exception declaration and a handler block +/// and creates a proper catch handler from them. +StmtResult +Sema::ActOnCXXCatchBlock(SourceLocation CatchLoc, Decl *ExDecl, + Stmt *HandlerBlock) { + // There's nothing to test that ActOnExceptionDecl didn't already test. + return Owned(new (Context) CXXCatchStmt(CatchLoc, + cast_or_null<VarDecl>(ExDecl), + HandlerBlock)); +} + +StmtResult +Sema::ActOnObjCAutoreleasePoolStmt(SourceLocation AtLoc, Stmt *Body) { + getCurFunction()->setHasBranchProtectedScope(); + return Owned(new (Context) ObjCAutoreleasePoolStmt(AtLoc, Body)); +} + +namespace { + +class TypeWithHandler { + QualType t; + CXXCatchStmt *stmt; +public: + TypeWithHandler(const QualType &type, CXXCatchStmt *statement) + : t(type), stmt(statement) {} + + // An arbitrary order is fine as long as it places identical + // types next to each other. + bool operator<(const TypeWithHandler &y) const { + if (t.getAsOpaquePtr() < y.t.getAsOpaquePtr()) + return true; + if (t.getAsOpaquePtr() > y.t.getAsOpaquePtr()) + return false; + else + return getTypeSpecStartLoc() < y.getTypeSpecStartLoc(); + } + + bool operator==(const TypeWithHandler& other) const { + return t == other.t; + } + + CXXCatchStmt *getCatchStmt() const { return stmt; } + SourceLocation getTypeSpecStartLoc() const { + return stmt->getExceptionDecl()->getTypeSpecStartLoc(); + } +}; + +} + +/// ActOnCXXTryBlock - Takes a try compound-statement and a number of +/// handlers and creates a try statement from them. +StmtResult Sema::ActOnCXXTryBlock(SourceLocation TryLoc, Stmt *TryBlock, + ArrayRef<Stmt *> Handlers) { + // Don't report an error if 'try' is used in system headers. + if (!getLangOpts().CXXExceptions && + !getSourceManager().isInSystemHeader(TryLoc)) + Diag(TryLoc, diag::err_exceptions_disabled) << "try"; + + const unsigned NumHandlers = Handlers.size(); + assert(NumHandlers > 0 && + "The parser shouldn't call this if there are no handlers."); + + SmallVector<TypeWithHandler, 8> TypesWithHandlers; + + for (unsigned i = 0; i < NumHandlers; ++i) { + CXXCatchStmt *Handler = cast<CXXCatchStmt>(Handlers[i]); + if (!Handler->getExceptionDecl()) { + if (i < NumHandlers - 1) + return StmtError(Diag(Handler->getLocStart(), + diag::err_early_catch_all)); + + continue; + } + + const QualType CaughtType = Handler->getCaughtType(); + const QualType CanonicalCaughtType = Context.getCanonicalType(CaughtType); + TypesWithHandlers.push_back(TypeWithHandler(CanonicalCaughtType, Handler)); + } + + // Detect handlers for the same type as an earlier one. + if (NumHandlers > 1) { + llvm::array_pod_sort(TypesWithHandlers.begin(), TypesWithHandlers.end()); + + TypeWithHandler prev = TypesWithHandlers[0]; + for (unsigned i = 1; i < TypesWithHandlers.size(); ++i) { + TypeWithHandler curr = TypesWithHandlers[i]; + + if (curr == prev) { + Diag(curr.getTypeSpecStartLoc(), + diag::warn_exception_caught_by_earlier_handler) + << curr.getCatchStmt()->getCaughtType().getAsString(); + Diag(prev.getTypeSpecStartLoc(), + diag::note_previous_exception_handler) + << prev.getCatchStmt()->getCaughtType().getAsString(); + } + + prev = curr; + } + } + + getCurFunction()->setHasBranchProtectedScope(); + + // FIXME: We should detect handlers that cannot catch anything because an + // earlier handler catches a superclass. Need to find a method that is not + // quadratic for this. + // Neither of these are explicitly forbidden, but every compiler detects them + // and warns. + + return Owned(CXXTryStmt::Create(Context, TryLoc, TryBlock, Handlers)); +} + +StmtResult +Sema::ActOnSEHTryBlock(bool IsCXXTry, + SourceLocation TryLoc, + Stmt *TryBlock, + Stmt *Handler) { + assert(TryBlock && Handler); + + getCurFunction()->setHasBranchProtectedScope(); + + return Owned(SEHTryStmt::Create(Context,IsCXXTry,TryLoc,TryBlock,Handler)); +} + +StmtResult +Sema::ActOnSEHExceptBlock(SourceLocation Loc, + Expr *FilterExpr, + Stmt *Block) { + assert(FilterExpr && Block); + + if(!FilterExpr->getType()->isIntegerType()) { + return StmtError(Diag(FilterExpr->getExprLoc(), + diag::err_filter_expression_integral) + << FilterExpr->getType()); + } + + return Owned(SEHExceptStmt::Create(Context,Loc,FilterExpr,Block)); +} + +StmtResult +Sema::ActOnSEHFinallyBlock(SourceLocation Loc, + Stmt *Block) { + assert(Block); + return Owned(SEHFinallyStmt::Create(Context,Loc,Block)); +} + +StmtResult Sema::BuildMSDependentExistsStmt(SourceLocation KeywordLoc, + bool IsIfExists, + NestedNameSpecifierLoc QualifierLoc, + DeclarationNameInfo NameInfo, + Stmt *Nested) +{ + return new (Context) MSDependentExistsStmt(KeywordLoc, IsIfExists, + QualifierLoc, NameInfo, + cast<CompoundStmt>(Nested)); +} + + +StmtResult Sema::ActOnMSDependentExistsStmt(SourceLocation KeywordLoc, + bool IsIfExists, + CXXScopeSpec &SS, + UnqualifiedId &Name, + Stmt *Nested) { + return BuildMSDependentExistsStmt(KeywordLoc, IsIfExists, + SS.getWithLocInContext(Context), + GetNameFromUnqualifiedId(Name), + Nested); +} + +RecordDecl* +Sema::CreateCapturedStmtRecordDecl(CapturedDecl *&CD, SourceLocation Loc, + unsigned NumParams) { + DeclContext *DC = CurContext; + while (!(DC->isFunctionOrMethod() || DC->isRecord() || DC->isFileContext())) + DC = DC->getParent(); + + RecordDecl *RD = 0; + if (getLangOpts().CPlusPlus) + RD = CXXRecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc, /*Id=*/0); + else + RD = RecordDecl::Create(Context, TTK_Struct, DC, Loc, Loc, /*Id=*/0); + + DC->addDecl(RD); + RD->setImplicit(); + RD->startDefinition(); + + CD = CapturedDecl::Create(Context, CurContext, NumParams); + DC->addDecl(CD); + + // Build the context parameter + assert(NumParams > 0 && "CapturedStmt requires context parameter"); + DC = CapturedDecl::castToDeclContext(CD); + IdentifierInfo *VarName = &Context.Idents.get("__context"); + QualType ParamType = Context.getPointerType(Context.getTagDeclType(RD)); + ImplicitParamDecl *Param + = ImplicitParamDecl::Create(Context, DC, Loc, VarName, ParamType); + DC->addDecl(Param); + + CD->setContextParam(Param); + + return RD; +} + +static void buildCapturedStmtCaptureList( + SmallVectorImpl<CapturedStmt::Capture> &Captures, + SmallVectorImpl<Expr *> &CaptureInits, + ArrayRef<CapturingScopeInfo::Capture> Candidates) { + + typedef ArrayRef<CapturingScopeInfo::Capture>::const_iterator CaptureIter; + for (CaptureIter Cap = Candidates.begin(); Cap != Candidates.end(); ++Cap) { + + if (Cap->isThisCapture()) { + Captures.push_back(CapturedStmt::Capture(Cap->getLocation(), + CapturedStmt::VCK_This)); + CaptureInits.push_back(Cap->getInitExpr()); + continue; + } + + assert(Cap->isReferenceCapture() && + "non-reference capture not yet implemented"); + + Captures.push_back(CapturedStmt::Capture(Cap->getLocation(), + CapturedStmt::VCK_ByRef, + Cap->getVariable())); + CaptureInits.push_back(Cap->getInitExpr()); + } +} + +void Sema::ActOnCapturedRegionStart(SourceLocation Loc, Scope *CurScope, + CapturedRegionKind Kind, + unsigned NumParams) { + CapturedDecl *CD = 0; + RecordDecl *RD = CreateCapturedStmtRecordDecl(CD, Loc, NumParams); + + // Enter the capturing scope for this captured region. + PushCapturedRegionScope(CurScope, CD, RD, Kind); + + if (CurScope) + PushDeclContext(CurScope, CD); + else + CurContext = CD; + + PushExpressionEvaluationContext(PotentiallyEvaluated); +} + +void Sema::ActOnCapturedRegionError() { + DiscardCleanupsInEvaluationContext(); + PopExpressionEvaluationContext(); + + CapturedRegionScopeInfo *RSI = getCurCapturedRegion(); + RecordDecl *Record = RSI->TheRecordDecl; + Record->setInvalidDecl(); + + SmallVector<Decl*, 4> Fields; + for (RecordDecl::field_iterator I = Record->field_begin(), + E = Record->field_end(); I != E; ++I) + Fields.push_back(*I); + ActOnFields(/*Scope=*/0, Record->getLocation(), Record, Fields, + SourceLocation(), SourceLocation(), /*AttributeList=*/0); + + PopDeclContext(); + PopFunctionScopeInfo(); +} + +StmtResult Sema::ActOnCapturedRegionEnd(Stmt *S) { + CapturedRegionScopeInfo *RSI = getCurCapturedRegion(); + + SmallVector<CapturedStmt::Capture, 4> Captures; + SmallVector<Expr *, 4> CaptureInits; + buildCapturedStmtCaptureList(Captures, CaptureInits, RSI->Captures); + + CapturedDecl *CD = RSI->TheCapturedDecl; + RecordDecl *RD = RSI->TheRecordDecl; + + CapturedStmt *Res = CapturedStmt::Create(getASTContext(), S, + RSI->CapRegionKind, Captures, + CaptureInits, CD, RD); + + CD->setBody(Res->getCapturedStmt()); + RD->completeDefinition(); + + DiscardCleanupsInEvaluationContext(); + PopExpressionEvaluationContext(); + + PopDeclContext(); + PopFunctionScopeInfo(); + + return Owned(Res); +} |
