1 //===--- SemaStmtAsm.cpp - Semantic Analysis for Asm Statements -----------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements semantic analysis for inline asm statements.
12 //===----------------------------------------------------------------------===//
14 #include "clang/AST/ExprCXX.h"
15 #include "clang/AST/RecordLayout.h"
16 #include "clang/AST/TypeLoc.h"
17 #include "clang/Basic/TargetInfo.h"
18 #include "clang/Lex/Preprocessor.h"
19 #include "clang/Sema/Initialization.h"
20 #include "clang/Sema/Lookup.h"
21 #include "clang/Sema/Scope.h"
22 #include "clang/Sema/ScopeInfo.h"
23 #include "clang/Sema/SemaInternal.h"
24 #include "llvm/ADT/ArrayRef.h"
25 #include "llvm/ADT/StringSet.h"
26 #include "llvm/MC/MCParser/MCAsmParser.h"
27 using namespace clang;
30 /// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently
31 /// ignore "noop" casts in places where an lvalue is required by an inline asm.
32 /// We emulate this behavior when -fheinous-gnu-extensions is specified, but
33 /// provide a strong guidance to not use it.
35 /// This method checks to see if the argument is an acceptable l-value and
36 /// returns false if it is a case we can handle.
37 static bool CheckAsmLValue(const Expr *E, Sema &S) {
38 // Type dependent expressions will be checked during instantiation.
39 if (E->isTypeDependent())
43 return false; // Cool, this is an lvalue.
45 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we
46 // are supposed to allow.
47 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context);
48 if (E != E2 && E2->isLValue()) {
49 if (!S.getLangOpts().HeinousExtensions)
50 S.Diag(E2->getLocStart(), diag::err_invalid_asm_cast_lvalue)
51 << E->getSourceRange();
53 S.Diag(E2->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
54 << E->getSourceRange();
55 // Accept, even if we emitted an error diagnostic.
59 // None of the above, just randomly invalid non-lvalue.
63 /// isOperandMentioned - Return true if the specified operand # is mentioned
64 /// anywhere in the decomposed asm string.
65 static bool isOperandMentioned(unsigned OpNo,
66 ArrayRef<GCCAsmStmt::AsmStringPiece> AsmStrPieces) {
67 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) {
68 const GCCAsmStmt::AsmStringPiece &Piece = AsmStrPieces[p];
69 if (!Piece.isOperand()) continue;
71 // If this is a reference to the input and if the input was the smaller
72 // one, then we have to reject this asm.
73 if (Piece.getOperandNo() == OpNo)
79 static bool CheckNakedParmReference(Expr *E, Sema &S) {
80 FunctionDecl *Func = dyn_cast<FunctionDecl>(S.CurContext);
83 if (!Func->hasAttr<NakedAttr>())
86 SmallVector<Expr*, 4> WorkList;
87 WorkList.push_back(E);
88 while (WorkList.size()) {
89 Expr *E = WorkList.pop_back_val();
90 if (isa<CXXThisExpr>(E)) {
91 S.Diag(E->getLocStart(), diag::err_asm_naked_this_ref);
92 S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
95 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
96 if (isa<ParmVarDecl>(DRE->getDecl())) {
97 S.Diag(DRE->getLocStart(), diag::err_asm_naked_parm_ref);
98 S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
102 for (Stmt *Child : E->children()) {
103 if (Expr *E = dyn_cast_or_null<Expr>(Child))
104 WorkList.push_back(E);
110 /// \brief Returns true if given expression is not compatible with inline
111 /// assembly's memory constraint; false otherwise.
112 static bool checkExprMemoryConstraintCompat(Sema &S, Expr *E,
113 TargetInfo::ConstraintInfo &Info,
114 bool is_input_expr) {
120 } EType = ExprSafeType;
122 // Bitfields, vector elements and global register variables are not
124 if (E->refersToBitField())
125 EType = ExprBitfield;
126 else if (E->refersToVectorElement())
127 EType = ExprVectorElt;
128 else if (E->refersToGlobalRegisterVar())
129 EType = ExprGlobalRegVar;
131 if (EType != ExprSafeType) {
132 S.Diag(E->getLocStart(), diag::err_asm_non_addr_value_in_memory_constraint)
133 << EType << is_input_expr << Info.getConstraintStr()
134 << E->getSourceRange();
141 // Extracting the register name from the Expression value,
142 // if there is no register name to extract, returns ""
143 static StringRef extractRegisterName(const Expr *Expression,
144 const TargetInfo &Target) {
145 Expression = Expression->IgnoreImpCasts();
146 if (const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(Expression)) {
147 // Handle cases where the expression is a variable
148 const VarDecl *Variable = dyn_cast<VarDecl>(AsmDeclRef->getDecl());
149 if (Variable && Variable->getStorageClass() == SC_Register) {
150 if (AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>())
151 if (Target.isValidGCCRegisterName(Attr->getLabel()))
152 return Target.getNormalizedGCCRegisterName(Attr->getLabel(), true);
158 // Checks if there is a conflict between the input and output lists with the
159 // clobbers list. If there's a conflict, returns the location of the
160 // conflicted clobber, else returns nullptr
161 static SourceLocation
162 getClobberConflictLocation(MultiExprArg Exprs, StringLiteral **Constraints,
163 StringLiteral **Clobbers, int NumClobbers,
164 const TargetInfo &Target, ASTContext &Cont) {
165 llvm::StringSet<> InOutVars;
166 // Collect all the input and output registers from the extended asm
167 // statement in order to check for conflicts with the clobber list
168 for (unsigned int i = 0; i < Exprs.size(); ++i) {
169 StringRef Constraint = Constraints[i]->getString();
170 StringRef InOutReg = Target.getConstraintRegister(
171 Constraint, extractRegisterName(Exprs[i], Target));
173 InOutVars.insert(InOutReg);
175 // Check for each item in the clobber list if it conflicts with the input
177 for (int i = 0; i < NumClobbers; ++i) {
178 StringRef Clobber = Clobbers[i]->getString();
179 // We only check registers, therefore we don't check cc and memory
181 if (Clobber == "cc" || Clobber == "memory")
183 Clobber = Target.getNormalizedGCCRegisterName(Clobber, true);
184 // Go over the output's registers we collected
185 if (InOutVars.count(Clobber))
186 return Clobbers[i]->getLocStart();
188 return SourceLocation();
191 StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
192 bool IsVolatile, unsigned NumOutputs,
193 unsigned NumInputs, IdentifierInfo **Names,
194 MultiExprArg constraints, MultiExprArg Exprs,
195 Expr *asmString, MultiExprArg clobbers,
196 SourceLocation RParenLoc) {
197 unsigned NumClobbers = clobbers.size();
198 StringLiteral **Constraints =
199 reinterpret_cast<StringLiteral**>(constraints.data());
200 StringLiteral *AsmString = cast<StringLiteral>(asmString);
201 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.data());
203 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
205 // The parser verifies that there is a string literal here.
206 assert(AsmString->isAscii());
208 // If we're compiling CUDA file and function attributes indicate that it's not
209 // for this compilation side, skip all the checks.
210 if (!DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl())) {
211 GCCAsmStmt *NS = new (Context) GCCAsmStmt(
212 Context, AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, Names,
213 Constraints, Exprs.data(), AsmString, NumClobbers, Clobbers, RParenLoc);
217 for (unsigned i = 0; i != NumOutputs; i++) {
218 StringLiteral *Literal = Constraints[i];
219 assert(Literal->isAscii());
221 StringRef OutputName;
223 OutputName = Names[i]->getName();
225 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName);
226 if (!Context.getTargetInfo().validateOutputConstraint(Info))
227 return StmtError(Diag(Literal->getLocStart(),
228 diag::err_asm_invalid_output_constraint)
229 << Info.getConstraintStr());
231 ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
236 // Check that the output exprs are valid lvalues.
237 Expr *OutputExpr = Exprs[i];
239 // Referring to parameters is not allowed in naked functions.
240 if (CheckNakedParmReference(OutputExpr, *this))
243 // Check that the output expression is compatible with memory constraint.
244 if (Info.allowsMemory() &&
245 checkExprMemoryConstraintCompat(*this, OutputExpr, Info, false))
248 OutputConstraintInfos.push_back(Info);
250 // If this is dependent, just continue.
251 if (OutputExpr->isTypeDependent())
254 Expr::isModifiableLvalueResult IsLV =
255 OutputExpr->isModifiableLvalue(Context, /*Loc=*/nullptr);
257 case Expr::MLV_Valid:
258 // Cool, this is an lvalue.
260 case Expr::MLV_ArrayType:
263 case Expr::MLV_LValueCast: {
264 const Expr *LVal = OutputExpr->IgnoreParenNoopCasts(Context);
265 if (!getLangOpts().HeinousExtensions) {
266 Diag(LVal->getLocStart(), diag::err_invalid_asm_cast_lvalue)
267 << OutputExpr->getSourceRange();
269 Diag(LVal->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
270 << OutputExpr->getSourceRange();
272 // Accept, even if we emitted an error diagnostic.
275 case Expr::MLV_IncompleteType:
276 case Expr::MLV_IncompleteVoidType:
277 if (RequireCompleteType(OutputExpr->getLocStart(), Exprs[i]->getType(),
278 diag::err_dereference_incomplete_type))
281 return StmtError(Diag(OutputExpr->getLocStart(),
282 diag::err_asm_invalid_lvalue_in_output)
283 << OutputExpr->getSourceRange());
286 unsigned Size = Context.getTypeSize(OutputExpr->getType());
287 if (!Context.getTargetInfo().validateOutputSize(Literal->getString(),
289 return StmtError(Diag(OutputExpr->getLocStart(),
290 diag::err_asm_invalid_output_size)
291 << Info.getConstraintStr());
294 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
296 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
297 StringLiteral *Literal = Constraints[i];
298 assert(Literal->isAscii());
302 InputName = Names[i]->getName();
304 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName);
305 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos,
307 return StmtError(Diag(Literal->getLocStart(),
308 diag::err_asm_invalid_input_constraint)
309 << Info.getConstraintStr());
312 ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
317 Expr *InputExpr = Exprs[i];
319 // Referring to parameters is not allowed in naked functions.
320 if (CheckNakedParmReference(InputExpr, *this))
323 // Check that the input expression is compatible with memory constraint.
324 if (Info.allowsMemory() &&
325 checkExprMemoryConstraintCompat(*this, InputExpr, Info, true))
328 // Only allow void types for memory constraints.
329 if (Info.allowsMemory() && !Info.allowsRegister()) {
330 if (CheckAsmLValue(InputExpr, *this))
331 return StmtError(Diag(InputExpr->getLocStart(),
332 diag::err_asm_invalid_lvalue_in_input)
333 << Info.getConstraintStr()
334 << InputExpr->getSourceRange());
335 } else if (Info.requiresImmediateConstant() && !Info.allowsRegister()) {
336 if (!InputExpr->isValueDependent()) {
338 if (!InputExpr->EvaluateAsInt(Result, Context))
340 Diag(InputExpr->getLocStart(), diag::err_asm_immediate_expected)
341 << Info.getConstraintStr() << InputExpr->getSourceRange());
342 if (!Info.isValidAsmImmediate(Result))
343 return StmtError(Diag(InputExpr->getLocStart(),
344 diag::err_invalid_asm_value_for_constraint)
345 << Result.toString(10) << Info.getConstraintStr()
346 << InputExpr->getSourceRange());
350 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]);
351 if (Result.isInvalid())
354 Exprs[i] = Result.get();
357 if (Info.allowsRegister()) {
358 if (InputExpr->getType()->isVoidType()) {
359 return StmtError(Diag(InputExpr->getLocStart(),
360 diag::err_asm_invalid_type_in_input)
361 << InputExpr->getType() << Info.getConstraintStr()
362 << InputExpr->getSourceRange());
366 InputConstraintInfos.push_back(Info);
368 const Type *Ty = Exprs[i]->getType().getTypePtr();
369 if (Ty->isDependentType())
372 if (!Ty->isVoidType() || !Info.allowsMemory())
373 if (RequireCompleteType(InputExpr->getLocStart(), Exprs[i]->getType(),
374 diag::err_dereference_incomplete_type))
377 unsigned Size = Context.getTypeSize(Ty);
378 if (!Context.getTargetInfo().validateInputSize(Literal->getString(),
380 return StmtError(Diag(InputExpr->getLocStart(),
381 diag::err_asm_invalid_input_size)
382 << Info.getConstraintStr());
385 // Check that the clobbers are valid.
386 for (unsigned i = 0; i != NumClobbers; i++) {
387 StringLiteral *Literal = Clobbers[i];
388 assert(Literal->isAscii());
390 StringRef Clobber = Literal->getString();
392 if (!Context.getTargetInfo().isValidClobber(Clobber))
393 return StmtError(Diag(Literal->getLocStart(),
394 diag::err_asm_unknown_register_name) << Clobber);
398 new (Context) GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
399 NumInputs, Names, Constraints, Exprs.data(),
400 AsmString, NumClobbers, Clobbers, RParenLoc);
401 // Validate the asm string, ensuring it makes sense given the operands we
403 SmallVector<GCCAsmStmt::AsmStringPiece, 8> Pieces;
405 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) {
406 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID)
407 << AsmString->getSourceRange();
411 // Validate constraints and modifiers.
412 for (unsigned i = 0, e = Pieces.size(); i != e; ++i) {
413 GCCAsmStmt::AsmStringPiece &Piece = Pieces[i];
414 if (!Piece.isOperand()) continue;
416 // Look for the correct constraint index.
417 unsigned ConstraintIdx = Piece.getOperandNo();
418 unsigned NumOperands = NS->getNumOutputs() + NS->getNumInputs();
420 // Look for the (ConstraintIdx - NumOperands + 1)th constraint with
422 if (ConstraintIdx >= NumOperands) {
423 unsigned I = 0, E = NS->getNumOutputs();
425 for (unsigned Cnt = ConstraintIdx - NumOperands; I != E; ++I)
426 if (OutputConstraintInfos[I].isReadWrite() && Cnt-- == 0) {
431 assert(I != E && "Invalid operand number should have been caught in "
432 " AnalyzeAsmString");
435 // Now that we have the right indexes go ahead and check.
436 StringLiteral *Literal = Constraints[ConstraintIdx];
437 const Type *Ty = Exprs[ConstraintIdx]->getType().getTypePtr();
438 if (Ty->isDependentType() || Ty->isIncompleteType())
441 unsigned Size = Context.getTypeSize(Ty);
442 std::string SuggestedModifier;
443 if (!Context.getTargetInfo().validateConstraintModifier(
444 Literal->getString(), Piece.getModifier(), Size,
445 SuggestedModifier)) {
446 Diag(Exprs[ConstraintIdx]->getLocStart(),
447 diag::warn_asm_mismatched_size_modifier);
449 if (!SuggestedModifier.empty()) {
450 auto B = Diag(Piece.getRange().getBegin(),
451 diag::note_asm_missing_constraint_modifier)
452 << SuggestedModifier;
453 SuggestedModifier = "%" + SuggestedModifier + Piece.getString();
454 B.AddFixItHint(FixItHint::CreateReplacement(Piece.getRange(),
460 // Validate tied input operands for type mismatches.
461 unsigned NumAlternatives = ~0U;
462 for (unsigned i = 0, e = OutputConstraintInfos.size(); i != e; ++i) {
463 TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i];
464 StringRef ConstraintStr = Info.getConstraintStr();
465 unsigned AltCount = ConstraintStr.count(',') + 1;
466 if (NumAlternatives == ~0U)
467 NumAlternatives = AltCount;
468 else if (NumAlternatives != AltCount)
469 return StmtError(Diag(NS->getOutputExpr(i)->getLocStart(),
470 diag::err_asm_unexpected_constraint_alternatives)
471 << NumAlternatives << AltCount);
473 SmallVector<size_t, 4> InputMatchedToOutput(OutputConstraintInfos.size(),
475 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
476 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
477 StringRef ConstraintStr = Info.getConstraintStr();
478 unsigned AltCount = ConstraintStr.count(',') + 1;
479 if (NumAlternatives == ~0U)
480 NumAlternatives = AltCount;
481 else if (NumAlternatives != AltCount)
482 return StmtError(Diag(NS->getInputExpr(i)->getLocStart(),
483 diag::err_asm_unexpected_constraint_alternatives)
484 << NumAlternatives << AltCount);
486 // If this is a tied constraint, verify that the output and input have
487 // either exactly the same type, or that they are int/ptr operands with the
488 // same size (int/long, int*/long, are ok etc).
489 if (!Info.hasTiedOperand()) continue;
491 unsigned TiedTo = Info.getTiedOperand();
492 unsigned InputOpNo = i+NumOutputs;
493 Expr *OutputExpr = Exprs[TiedTo];
494 Expr *InputExpr = Exprs[InputOpNo];
496 // Make sure no more than one input constraint matches each output.
497 assert(TiedTo < InputMatchedToOutput.size() && "TiedTo value out of range");
498 if (InputMatchedToOutput[TiedTo] != ~0U) {
499 Diag(NS->getInputExpr(i)->getLocStart(),
500 diag::err_asm_input_duplicate_match)
502 Diag(NS->getInputExpr(InputMatchedToOutput[TiedTo])->getLocStart(),
503 diag::note_asm_input_duplicate_first)
507 InputMatchedToOutput[TiedTo] = i;
509 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent())
512 QualType InTy = InputExpr->getType();
513 QualType OutTy = OutputExpr->getType();
514 if (Context.hasSameType(InTy, OutTy))
515 continue; // All types can be tied to themselves.
517 // Decide if the input and output are in the same domain (integer/ptr or
520 AD_Int, AD_FP, AD_Other
521 } InputDomain, OutputDomain;
523 if (InTy->isIntegerType() || InTy->isPointerType())
524 InputDomain = AD_Int;
525 else if (InTy->isRealFloatingType())
528 InputDomain = AD_Other;
530 if (OutTy->isIntegerType() || OutTy->isPointerType())
531 OutputDomain = AD_Int;
532 else if (OutTy->isRealFloatingType())
533 OutputDomain = AD_FP;
535 OutputDomain = AD_Other;
537 // They are ok if they are the same size and in the same domain. This
538 // allows tying things like:
540 // void* to int if they are the same size.
541 // double to long double if they are the same size.
543 uint64_t OutSize = Context.getTypeSize(OutTy);
544 uint64_t InSize = Context.getTypeSize(InTy);
545 if (OutSize == InSize && InputDomain == OutputDomain &&
546 InputDomain != AD_Other)
549 // If the smaller input/output operand is not mentioned in the asm string,
550 // then we can promote the smaller one to a larger input and the asm string
552 bool SmallerValueMentioned = false;
554 // If this is a reference to the input and if the input was the smaller
555 // one, then we have to reject this asm.
556 if (isOperandMentioned(InputOpNo, Pieces)) {
557 // This is a use in the asm string of the smaller operand. Since we
558 // codegen this by promoting to a wider value, the asm will get printed
560 SmallerValueMentioned |= InSize < OutSize;
562 if (isOperandMentioned(TiedTo, Pieces)) {
563 // If this is a reference to the output, and if the output is the larger
564 // value, then it's ok because we'll promote the input to the larger type.
565 SmallerValueMentioned |= OutSize < InSize;
568 // If the smaller value wasn't mentioned in the asm string, and if the
569 // output was a register, just extend the shorter one to the size of the
571 if (!SmallerValueMentioned && InputDomain != AD_Other &&
572 OutputConstraintInfos[TiedTo].allowsRegister())
575 // Either both of the operands were mentioned or the smaller one was
576 // mentioned. One more special case that we'll allow: if the tied input is
577 // integer, unmentioned, and is a constant, then we'll allow truncating it
578 // down to the size of the destination.
579 if (InputDomain == AD_Int && OutputDomain == AD_Int &&
580 !isOperandMentioned(InputOpNo, Pieces) &&
581 InputExpr->isEvaluatable(Context)) {
583 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast);
584 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).get();
585 Exprs[InputOpNo] = InputExpr;
586 NS->setInputExpr(i, InputExpr);
590 Diag(InputExpr->getLocStart(),
591 diag::err_asm_tying_incompatible_types)
592 << InTy << OutTy << OutputExpr->getSourceRange()
593 << InputExpr->getSourceRange();
597 // Check for conflicts between clobber list and input or output lists
598 SourceLocation ConstraintLoc =
599 getClobberConflictLocation(Exprs, Constraints, Clobbers, NumClobbers,
600 Context.getTargetInfo(), Context);
601 if (ConstraintLoc.isValid())
602 return Diag(ConstraintLoc, diag::error_inoutput_conflict_with_clobber);
607 static void fillInlineAsmTypeInfo(const ASTContext &Context, QualType T,
608 llvm::InlineAsmIdentifierInfo &Info) {
609 // Compute the type size (and array length if applicable?).
610 Info.Type = Info.Size = Context.getTypeSizeInChars(T).getQuantity();
611 if (T->isArrayType()) {
612 const ArrayType *ATy = Context.getAsArrayType(T);
613 Info.Type = Context.getTypeSizeInChars(ATy->getElementType()).getQuantity();
614 Info.Length = Info.Size / Info.Type;
618 ExprResult Sema::LookupInlineAsmIdentifier(CXXScopeSpec &SS,
619 SourceLocation TemplateKWLoc,
621 llvm::InlineAsmIdentifierInfo &Info,
622 bool IsUnevaluatedContext) {
625 if (IsUnevaluatedContext)
626 PushExpressionEvaluationContext(UnevaluatedAbstract,
627 ReuseLambdaContextDecl);
629 ExprResult Result = ActOnIdExpression(getCurScope(), SS, TemplateKWLoc, Id,
630 /*trailing lparen*/ false,
631 /*is & operand*/ false,
632 /*CorrectionCandidateCallback=*/nullptr,
633 /*IsInlineAsmIdentifier=*/ true);
635 if (IsUnevaluatedContext)
636 PopExpressionEvaluationContext();
638 if (!Result.isUsable()) return Result;
640 Result = CheckPlaceholderExpr(Result.get());
641 if (!Result.isUsable()) return Result;
643 // Referring to parameters is not allowed in naked functions.
644 if (CheckNakedParmReference(Result.get(), *this))
647 QualType T = Result.get()->getType();
649 if (T->isDependentType()) {
653 // Any sort of function type is fine.
654 if (T->isFunctionType()) {
658 // Otherwise, it needs to be a complete type.
659 if (RequireCompleteExprType(Result.get(), diag::err_asm_incomplete_type)) {
663 fillInlineAsmTypeInfo(Context, T, Info);
665 // We can work with the expression as long as it's not an r-value.
666 if (!Result.get()->isRValue())
667 Info.IsVarDecl = true;
672 bool Sema::LookupInlineAsmField(StringRef Base, StringRef Member,
673 unsigned &Offset, SourceLocation AsmLoc) {
675 SmallVector<StringRef, 2> Members;
676 Member.split(Members, ".");
678 LookupResult BaseResult(*this, &Context.Idents.get(Base), SourceLocation(),
681 if (!LookupName(BaseResult, getCurScope()))
684 if(!BaseResult.isSingleResult())
686 NamedDecl *FoundDecl = BaseResult.getFoundDecl();
687 for (StringRef NextMember : Members) {
688 const RecordType *RT = nullptr;
689 if (VarDecl *VD = dyn_cast<VarDecl>(FoundDecl))
690 RT = VD->getType()->getAs<RecordType>();
691 else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(FoundDecl)) {
692 MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
693 RT = TD->getUnderlyingType()->getAs<RecordType>();
694 } else if (TypeDecl *TD = dyn_cast<TypeDecl>(FoundDecl))
695 RT = TD->getTypeForDecl()->getAs<RecordType>();
696 else if (FieldDecl *TD = dyn_cast<FieldDecl>(FoundDecl))
697 RT = TD->getType()->getAs<RecordType>();
701 if (RequireCompleteType(AsmLoc, QualType(RT, 0),
702 diag::err_asm_incomplete_type))
705 LookupResult FieldResult(*this, &Context.Idents.get(NextMember),
706 SourceLocation(), LookupMemberName);
708 if (!LookupQualifiedName(FieldResult, RT->getDecl()))
711 if (!FieldResult.isSingleResult())
713 FoundDecl = FieldResult.getFoundDecl();
715 // FIXME: Handle IndirectFieldDecl?
716 FieldDecl *FD = dyn_cast<FieldDecl>(FoundDecl);
720 const ASTRecordLayout &RL = Context.getASTRecordLayout(RT->getDecl());
721 unsigned i = FD->getFieldIndex();
722 CharUnits Result = Context.toCharUnitsFromBits(RL.getFieldOffset(i));
723 Offset += (unsigned)Result.getQuantity();
730 Sema::LookupInlineAsmVarDeclField(Expr *E, StringRef Member,
731 llvm::InlineAsmIdentifierInfo &Info,
732 SourceLocation AsmLoc) {
735 QualType T = E->getType();
736 if (T->isDependentType()) {
737 DeclarationNameInfo NameInfo;
738 NameInfo.setLoc(AsmLoc);
739 NameInfo.setName(&Context.Idents.get(Member));
740 return CXXDependentScopeMemberExpr::Create(
741 Context, E, T, /*IsArrow=*/false, AsmLoc, NestedNameSpecifierLoc(),
743 /*FirstQualifierInScope=*/nullptr, NameInfo, /*TemplateArgs=*/nullptr);
746 const RecordType *RT = T->getAs<RecordType>();
747 // FIXME: Diagnose this as field access into a scalar type.
751 LookupResult FieldResult(*this, &Context.Idents.get(Member), AsmLoc,
754 if (!LookupQualifiedName(FieldResult, RT->getDecl()))
757 // Only normal and indirect field results will work.
758 ValueDecl *FD = dyn_cast<FieldDecl>(FieldResult.getFoundDecl());
760 FD = dyn_cast<IndirectFieldDecl>(FieldResult.getFoundDecl());
764 // Make an Expr to thread through OpDecl.
765 ExprResult Result = BuildMemberReferenceExpr(
766 E, E->getType(), AsmLoc, /*IsArrow=*/false, CXXScopeSpec(),
767 SourceLocation(), nullptr, FieldResult, nullptr, nullptr);
768 if (Result.isInvalid())
770 Info.OpDecl = Result.get();
772 fillInlineAsmTypeInfo(Context, Result.get()->getType(), Info);
774 // Fields are "variables" as far as inline assembly is concerned.
775 Info.IsVarDecl = true;
780 StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
781 ArrayRef<Token> AsmToks,
783 unsigned NumOutputs, unsigned NumInputs,
784 ArrayRef<StringRef> Constraints,
785 ArrayRef<StringRef> Clobbers,
786 ArrayRef<Expr*> Exprs,
787 SourceLocation EndLoc) {
788 bool IsSimple = (NumOutputs != 0 || NumInputs != 0);
789 getCurFunction()->setHasBranchProtectedScope();
791 new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, IsSimple,
792 /*IsVolatile*/ true, AsmToks, NumOutputs, NumInputs,
793 Constraints, Exprs, AsmString,
798 LabelDecl *Sema::GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
799 SourceLocation Location,
801 LabelDecl* Label = LookupOrCreateLabel(PP.getIdentifierInfo(ExternalLabelName),
804 if (Label->isMSAsmLabel()) {
805 // If we have previously created this label implicitly, mark it as used.
806 Label->markUsed(Context);
808 // Otherwise, insert it, but only resolve it if we have seen the label itself.
809 std::string InternalName;
810 llvm::raw_string_ostream OS(InternalName);
811 // Create an internal name for the label. The name should not be a valid
812 // mangled name, and should be unique. We use a dot to make the name an
813 // invalid mangled name. We use LLVM's inline asm ${:uid} escape so that a
814 // unique label is generated each time this blob is emitted, even after
816 OS << "__MSASMLABEL_.${:uid}__";
817 for (char C : ExternalLabelName) {
819 // We escape '$' in asm strings by replacing it with "$$"
823 Label->setMSAsmLabel(OS.str());
826 // The label might have been created implicitly from a previously encountered
827 // goto statement. So, for both newly created and looked up labels, we mark
829 Label->setMSAsmLabelResolved();
831 // Adjust their location for being able to generate accurate diagnostics.
832 Label->setLocation(Location);