diff options
Diffstat (limited to 'contrib/llvm/tools/clang/lib/Sema/SemaStmtAsm.cpp')
| -rw-r--r-- | contrib/llvm/tools/clang/lib/Sema/SemaStmtAsm.cpp | 487 |
1 files changed, 487 insertions, 0 deletions
diff --git a/contrib/llvm/tools/clang/lib/Sema/SemaStmtAsm.cpp b/contrib/llvm/tools/clang/lib/Sema/SemaStmtAsm.cpp new file mode 100644 index 0000000..9169032 --- /dev/null +++ b/contrib/llvm/tools/clang/lib/Sema/SemaStmtAsm.cpp @@ -0,0 +1,487 @@ +//===--- SemaStmtAsm.cpp - Semantic Analysis for Asm 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 inline asm statements. +// +//===----------------------------------------------------------------------===// + +#include "clang/Sema/SemaInternal.h" +#include "clang/AST/RecordLayout.h" +#include "clang/AST/TypeLoc.h" +#include "clang/Basic/TargetInfo.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/BitVector.h" +using namespace clang; +using namespace sema; + +/// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently +/// ignore "noop" casts in places where an lvalue is required by an inline asm. +/// We emulate this behavior when -fheinous-gnu-extensions is specified, but +/// provide a strong guidance to not use it. +/// +/// This method checks to see if the argument is an acceptable l-value and +/// returns false if it is a case we can handle. +static bool CheckAsmLValue(const Expr *E, Sema &S) { + // Type dependent expressions will be checked during instantiation. + if (E->isTypeDependent()) + return false; + + if (E->isLValue()) + return false; // Cool, this is an lvalue. + + // Okay, this is not an lvalue, but perhaps it is the result of a cast that we + // are supposed to allow. + const Expr *E2 = E->IgnoreParenNoopCasts(S.Context); + if (E != E2 && E2->isLValue()) { + if (!S.getLangOpts().HeinousExtensions) + S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue) + << E->getSourceRange(); + else + S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue) + << E->getSourceRange(); + // Accept, even if we emitted an error diagnostic. + return false; + } + + // None of the above, just randomly invalid non-lvalue. + return true; +} + +/// isOperandMentioned - Return true if the specified operand # is mentioned +/// anywhere in the decomposed asm string. +static bool isOperandMentioned(unsigned OpNo, + ArrayRef<GCCAsmStmt::AsmStringPiece> AsmStrPieces) { + for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) { + const GCCAsmStmt::AsmStringPiece &Piece = AsmStrPieces[p]; + if (!Piece.isOperand()) continue; + + // If this is a reference to the input and if the input was the smaller + // one, then we have to reject this asm. + if (Piece.getOperandNo() == OpNo) + return true; + } + return false; +} + +StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple, + bool IsVolatile, unsigned NumOutputs, + unsigned NumInputs, IdentifierInfo **Names, + MultiExprArg constraints, MultiExprArg Exprs, + Expr *asmString, MultiExprArg clobbers, + SourceLocation RParenLoc) { + unsigned NumClobbers = clobbers.size(); + StringLiteral **Constraints = + reinterpret_cast<StringLiteral**>(constraints.data()); + StringLiteral *AsmString = cast<StringLiteral>(asmString); + StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.data()); + + SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos; + + // The parser verifies that there is a string literal here. + if (!AsmString->isAscii()) + return StmtError(Diag(AsmString->getLocStart(),diag::err_asm_wide_character) + << AsmString->getSourceRange()); + + for (unsigned i = 0; i != NumOutputs; i++) { + StringLiteral *Literal = Constraints[i]; + if (!Literal->isAscii()) + return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) + << Literal->getSourceRange()); + + StringRef OutputName; + if (Names[i]) + OutputName = Names[i]->getName(); + + TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName); + if (!Context.getTargetInfo().validateOutputConstraint(Info)) + return StmtError(Diag(Literal->getLocStart(), + diag::err_asm_invalid_output_constraint) + << Info.getConstraintStr()); + + // Check that the output exprs are valid lvalues. + Expr *OutputExpr = Exprs[i]; + if (CheckAsmLValue(OutputExpr, *this)) + return StmtError(Diag(OutputExpr->getLocStart(), + diag::err_asm_invalid_lvalue_in_output) + << OutputExpr->getSourceRange()); + + if (RequireCompleteType(OutputExpr->getLocStart(), Exprs[i]->getType(), + diag::err_dereference_incomplete_type)) + return StmtError(); + + OutputConstraintInfos.push_back(Info); + } + + SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos; + + for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) { + StringLiteral *Literal = Constraints[i]; + if (!Literal->isAscii()) + return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) + << Literal->getSourceRange()); + + StringRef InputName; + if (Names[i]) + InputName = Names[i]->getName(); + + TargetInfo::ConstraintInfo Info(Literal->getString(), InputName); + if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos.data(), + NumOutputs, Info)) { + return StmtError(Diag(Literal->getLocStart(), + diag::err_asm_invalid_input_constraint) + << Info.getConstraintStr()); + } + + Expr *InputExpr = Exprs[i]; + + // Only allow void types for memory constraints. + if (Info.allowsMemory() && !Info.allowsRegister()) { + if (CheckAsmLValue(InputExpr, *this)) + return StmtError(Diag(InputExpr->getLocStart(), + diag::err_asm_invalid_lvalue_in_input) + << Info.getConstraintStr() + << InputExpr->getSourceRange()); + } + + if (Info.allowsRegister()) { + if (InputExpr->getType()->isVoidType()) { + return StmtError(Diag(InputExpr->getLocStart(), + diag::err_asm_invalid_type_in_input) + << InputExpr->getType() << Info.getConstraintStr() + << InputExpr->getSourceRange()); + } + } + + ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]); + if (Result.isInvalid()) + return StmtError(); + + Exprs[i] = Result.take(); + InputConstraintInfos.push_back(Info); + + const Type *Ty = Exprs[i]->getType().getTypePtr(); + if (Ty->isDependentType()) + continue; + + if (!Ty->isVoidType() || !Info.allowsMemory()) + if (RequireCompleteType(InputExpr->getLocStart(), Exprs[i]->getType(), + diag::err_dereference_incomplete_type)) + return StmtError(); + + unsigned Size = Context.getTypeSize(Ty); + if (!Context.getTargetInfo().validateInputSize(Literal->getString(), + Size)) + return StmtError(Diag(InputExpr->getLocStart(), + diag::err_asm_invalid_input_size) + << Info.getConstraintStr()); + } + + // Check that the clobbers are valid. + for (unsigned i = 0; i != NumClobbers; i++) { + StringLiteral *Literal = Clobbers[i]; + if (!Literal->isAscii()) + return StmtError(Diag(Literal->getLocStart(),diag::err_asm_wide_character) + << Literal->getSourceRange()); + + StringRef Clobber = Literal->getString(); + + if (!Context.getTargetInfo().isValidClobber(Clobber)) + return StmtError(Diag(Literal->getLocStart(), + diag::err_asm_unknown_register_name) << Clobber); + } + + GCCAsmStmt *NS = + new (Context) GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs, + NumInputs, Names, Constraints, Exprs.data(), + AsmString, NumClobbers, Clobbers, RParenLoc); + // Validate the asm string, ensuring it makes sense given the operands we + // have. + SmallVector<GCCAsmStmt::AsmStringPiece, 8> Pieces; + unsigned DiagOffs; + if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) { + Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID) + << AsmString->getSourceRange(); + return StmtError(); + } + + // Validate constraints and modifiers. + for (unsigned i = 0, e = Pieces.size(); i != e; ++i) { + GCCAsmStmt::AsmStringPiece &Piece = Pieces[i]; + if (!Piece.isOperand()) continue; + + // Look for the correct constraint index. + unsigned Idx = 0; + unsigned ConstraintIdx = 0; + for (unsigned i = 0, e = NS->getNumOutputs(); i != e; ++i, ++ConstraintIdx) { + TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i]; + if (Idx == Piece.getOperandNo()) + break; + ++Idx; + + if (Info.isReadWrite()) { + if (Idx == Piece.getOperandNo()) + break; + ++Idx; + } + } + + for (unsigned i = 0, e = NS->getNumInputs(); i != e; ++i, ++ConstraintIdx) { + TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; + if (Idx == Piece.getOperandNo()) + break; + ++Idx; + + if (Info.isReadWrite()) { + if (Idx == Piece.getOperandNo()) + break; + ++Idx; + } + } + + // Now that we have the right indexes go ahead and check. + StringLiteral *Literal = Constraints[ConstraintIdx]; + const Type *Ty = Exprs[ConstraintIdx]->getType().getTypePtr(); + if (Ty->isDependentType() || Ty->isIncompleteType()) + continue; + + unsigned Size = Context.getTypeSize(Ty); + if (!Context.getTargetInfo() + .validateConstraintModifier(Literal->getString(), Piece.getModifier(), + Size)) + Diag(Exprs[ConstraintIdx]->getLocStart(), + diag::warn_asm_mismatched_size_modifier); + } + + // Validate tied input operands for type mismatches. + for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) { + TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i]; + + // If this is a tied constraint, verify that the output and input have + // either exactly the same type, or that they are int/ptr operands with the + // same size (int/long, int*/long, are ok etc). + if (!Info.hasTiedOperand()) continue; + + unsigned TiedTo = Info.getTiedOperand(); + unsigned InputOpNo = i+NumOutputs; + Expr *OutputExpr = Exprs[TiedTo]; + Expr *InputExpr = Exprs[InputOpNo]; + + if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent()) + continue; + + QualType InTy = InputExpr->getType(); + QualType OutTy = OutputExpr->getType(); + if (Context.hasSameType(InTy, OutTy)) + continue; // All types can be tied to themselves. + + // Decide if the input and output are in the same domain (integer/ptr or + // floating point. + enum AsmDomain { + AD_Int, AD_FP, AD_Other + } InputDomain, OutputDomain; + + if (InTy->isIntegerType() || InTy->isPointerType()) + InputDomain = AD_Int; + else if (InTy->isRealFloatingType()) + InputDomain = AD_FP; + else + InputDomain = AD_Other; + + if (OutTy->isIntegerType() || OutTy->isPointerType()) + OutputDomain = AD_Int; + else if (OutTy->isRealFloatingType()) + OutputDomain = AD_FP; + else + OutputDomain = AD_Other; + + // They are ok if they are the same size and in the same domain. This + // allows tying things like: + // void* to int* + // void* to int if they are the same size. + // double to long double if they are the same size. + // + uint64_t OutSize = Context.getTypeSize(OutTy); + uint64_t InSize = Context.getTypeSize(InTy); + if (OutSize == InSize && InputDomain == OutputDomain && + InputDomain != AD_Other) + continue; + + // If the smaller input/output operand is not mentioned in the asm string, + // then we can promote the smaller one to a larger input and the asm string + // won't notice. + bool SmallerValueMentioned = false; + + // If this is a reference to the input and if the input was the smaller + // one, then we have to reject this asm. + if (isOperandMentioned(InputOpNo, Pieces)) { + // This is a use in the asm string of the smaller operand. Since we + // codegen this by promoting to a wider value, the asm will get printed + // "wrong". + SmallerValueMentioned |= InSize < OutSize; + } + if (isOperandMentioned(TiedTo, Pieces)) { + // If this is a reference to the output, and if the output is the larger + // value, then it's ok because we'll promote the input to the larger type. + SmallerValueMentioned |= OutSize < InSize; + } + + // If the smaller value wasn't mentioned in the asm string, and if the + // output was a register, just extend the shorter one to the size of the + // larger one. + if (!SmallerValueMentioned && InputDomain != AD_Other && + OutputConstraintInfos[TiedTo].allowsRegister()) + continue; + + // Either both of the operands were mentioned or the smaller one was + // mentioned. One more special case that we'll allow: if the tied input is + // integer, unmentioned, and is a constant, then we'll allow truncating it + // down to the size of the destination. + if (InputDomain == AD_Int && OutputDomain == AD_Int && + !isOperandMentioned(InputOpNo, Pieces) && + InputExpr->isEvaluatable(Context)) { + CastKind castKind = + (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast); + InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).take(); + Exprs[InputOpNo] = InputExpr; + NS->setInputExpr(i, InputExpr); + continue; + } + + Diag(InputExpr->getLocStart(), + diag::err_asm_tying_incompatible_types) + << InTy << OutTy << OutputExpr->getSourceRange() + << InputExpr->getSourceRange(); + return StmtError(); + } + + return Owned(NS); +} + +ExprResult Sema::LookupInlineAsmIdentifier(CXXScopeSpec &SS, + SourceLocation TemplateKWLoc, + UnqualifiedId &Id, + InlineAsmIdentifierInfo &Info, + bool IsUnevaluatedContext) { + Info.clear(); + + if (IsUnevaluatedContext) + PushExpressionEvaluationContext(UnevaluatedAbstract, + ReuseLambdaContextDecl); + + ExprResult Result = ActOnIdExpression(getCurScope(), SS, TemplateKWLoc, Id, + /*trailing lparen*/ false, + /*is & operand*/ false, + /*CorrectionCandidateCallback=*/0, + /*IsInlineAsmIdentifier=*/ true); + + if (IsUnevaluatedContext) + PopExpressionEvaluationContext(); + + if (!Result.isUsable()) return Result; + + Result = CheckPlaceholderExpr(Result.take()); + if (!Result.isUsable()) return Result; + + QualType T = Result.get()->getType(); + + // For now, reject dependent types. + if (T->isDependentType()) { + Diag(Id.getLocStart(), diag::err_asm_incomplete_type) << T; + return ExprError(); + } + + // Any sort of function type is fine. + if (T->isFunctionType()) { + return Result; + } + + // Otherwise, it needs to be a complete type. + if (RequireCompleteExprType(Result.get(), diag::err_asm_incomplete_type)) { + return ExprError(); + } + + // Compute the type size (and array length if applicable?). + Info.Type = Info.Size = Context.getTypeSizeInChars(T).getQuantity(); + if (T->isArrayType()) { + const ArrayType *ATy = Context.getAsArrayType(T); + Info.Type = Context.getTypeSizeInChars(ATy->getElementType()).getQuantity(); + Info.Length = Info.Size / Info.Type; + } + + // We can work with the expression as long as it's not an r-value. + if (!Result.get()->isRValue()) + Info.IsVarDecl = true; + + return Result; +} + +bool Sema::LookupInlineAsmField(StringRef Base, StringRef Member, + unsigned &Offset, SourceLocation AsmLoc) { + Offset = 0; + LookupResult BaseResult(*this, &Context.Idents.get(Base), SourceLocation(), + LookupOrdinaryName); + + if (!LookupName(BaseResult, getCurScope())) + return true; + + if (!BaseResult.isSingleResult()) + return true; + + const RecordType *RT = 0; + NamedDecl *FoundDecl = BaseResult.getFoundDecl(); + if (VarDecl *VD = dyn_cast<VarDecl>(FoundDecl)) + RT = VD->getType()->getAs<RecordType>(); + else if (TypedefDecl *TD = dyn_cast<TypedefDecl>(FoundDecl)) + RT = TD->getUnderlyingType()->getAs<RecordType>(); + if (!RT) + return true; + + if (RequireCompleteType(AsmLoc, QualType(RT, 0), 0)) + return true; + + LookupResult FieldResult(*this, &Context.Idents.get(Member), SourceLocation(), + LookupMemberName); + + if (!LookupQualifiedName(FieldResult, RT->getDecl())) + return true; + + // FIXME: Handle IndirectFieldDecl? + FieldDecl *FD = dyn_cast<FieldDecl>(FieldResult.getFoundDecl()); + if (!FD) + return true; + + const ASTRecordLayout &RL = Context.getASTRecordLayout(RT->getDecl()); + unsigned i = FD->getFieldIndex(); + CharUnits Result = Context.toCharUnitsFromBits(RL.getFieldOffset(i)); + Offset = (unsigned)Result.getQuantity(); + + return false; +} + +StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc, + ArrayRef<Token> AsmToks, + StringRef AsmString, + unsigned NumOutputs, unsigned NumInputs, + ArrayRef<StringRef> Constraints, + ArrayRef<StringRef> Clobbers, + ArrayRef<Expr*> Exprs, + SourceLocation EndLoc) { + bool IsSimple = (NumOutputs != 0 || NumInputs != 0); + MSAsmStmt *NS = + new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, IsSimple, + /*IsVolatile*/ true, AsmToks, NumOutputs, NumInputs, + Constraints, Exprs, AsmString, + Clobbers, EndLoc); + return Owned(NS); +} |
