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.
66 isOperandMentioned(unsigned OpNo,
67 ArrayRef<GCCAsmStmt::AsmStringPiece> AsmStrPieces) {
68 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) {
69 const GCCAsmStmt::AsmStringPiece &Piece = AsmStrPieces[p];
70 if (!Piece.isOperand())
73 // If this is a reference to the input and if the input was the smaller
74 // one, then we have to reject this asm.
75 if (Piece.getOperandNo() == OpNo)
81 static bool CheckNakedParmReference(Expr *E, Sema &S) {
82 FunctionDecl *Func = dyn_cast<FunctionDecl>(S.CurContext);
85 if (!Func->hasAttr<NakedAttr>())
88 SmallVector<Expr*, 4> WorkList;
89 WorkList.push_back(E);
90 while (WorkList.size()) {
91 Expr *E = WorkList.pop_back_val();
92 if (isa<CXXThisExpr>(E)) {
93 S.Diag(E->getLocStart(), diag::err_asm_naked_this_ref);
94 S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
97 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
98 if (isa<ParmVarDecl>(DRE->getDecl())) {
99 S.Diag(DRE->getLocStart(), diag::err_asm_naked_parm_ref);
100 S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
104 for (Stmt *Child : E->children()) {
105 if (Expr *E = dyn_cast_or_null<Expr>(Child))
106 WorkList.push_back(E);
112 /// \brief Returns true if given expression is not compatible with inline
113 /// assembly's memory constraint; false otherwise.
114 static bool checkExprMemoryConstraintCompat(Sema &S, Expr *E,
115 TargetInfo::ConstraintInfo &Info,
116 bool is_input_expr) {
122 } EType = ExprSafeType;
124 // Bitfields, vector elements and global register variables are not
126 if (E->refersToBitField())
127 EType = ExprBitfield;
128 else if (E->refersToVectorElement())
129 EType = ExprVectorElt;
130 else if (E->refersToGlobalRegisterVar())
131 EType = ExprGlobalRegVar;
133 if (EType != ExprSafeType) {
134 S.Diag(E->getLocStart(), diag::err_asm_non_addr_value_in_memory_constraint)
135 << EType << is_input_expr << Info.getConstraintStr()
136 << E->getSourceRange();
143 // Extracting the register name from the Expression value,
144 // if there is no register name to extract, returns ""
145 static StringRef extractRegisterName(const Expr *Expression,
146 const TargetInfo &Target) {
147 Expression = Expression->IgnoreImpCasts();
148 if (const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(Expression)) {
149 // Handle cases where the expression is a variable
150 const VarDecl *Variable = dyn_cast<VarDecl>(AsmDeclRef->getDecl());
151 if (Variable && Variable->getStorageClass() == SC_Register) {
152 if (AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>())
153 if (Target.isValidGCCRegisterName(Attr->getLabel()))
154 return Target.getNormalizedGCCRegisterName(Attr->getLabel(), true);
160 // Checks if there is a conflict between the input and output lists with the
161 // clobbers list. If there's a conflict, returns the location of the
162 // conflicted clobber, else returns nullptr
163 static SourceLocation
164 getClobberConflictLocation(MultiExprArg Exprs, StringLiteral **Constraints,
165 StringLiteral **Clobbers, int NumClobbers,
166 const TargetInfo &Target, ASTContext &Cont) {
167 llvm::StringSet<> InOutVars;
168 // Collect all the input and output registers from the extended asm
169 // statement in order to check for conflicts with the clobber list
170 for (unsigned int i = 0; i < Exprs.size(); ++i) {
171 StringRef Constraint = Constraints[i]->getString();
172 StringRef InOutReg = Target.getConstraintRegister(
173 Constraint, extractRegisterName(Exprs[i], Target));
175 InOutVars.insert(InOutReg);
177 // Check for each item in the clobber list if it conflicts with the input
179 for (int i = 0; i < NumClobbers; ++i) {
180 StringRef Clobber = Clobbers[i]->getString();
181 // We only check registers, therefore we don't check cc and memory
183 if (Clobber == "cc" || Clobber == "memory")
185 Clobber = Target.getNormalizedGCCRegisterName(Clobber, true);
186 // Go over the output's registers we collected
187 if (InOutVars.count(Clobber))
188 return Clobbers[i]->getLocStart();
190 return SourceLocation();
193 StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
194 bool IsVolatile, unsigned NumOutputs,
195 unsigned NumInputs, IdentifierInfo **Names,
196 MultiExprArg constraints, MultiExprArg Exprs,
197 Expr *asmString, MultiExprArg clobbers,
198 SourceLocation RParenLoc) {
199 unsigned NumClobbers = clobbers.size();
200 StringLiteral **Constraints =
201 reinterpret_cast<StringLiteral**>(constraints.data());
202 StringLiteral *AsmString = cast<StringLiteral>(asmString);
203 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.data());
205 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
207 // The parser verifies that there is a string literal here.
208 assert(AsmString->isAscii());
210 // If we're compiling CUDA file and function attributes indicate that it's not
211 // for this compilation side, skip all the checks.
212 if (!DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl())) {
213 GCCAsmStmt *NS = new (Context) GCCAsmStmt(
214 Context, AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, Names,
215 Constraints, Exprs.data(), AsmString, NumClobbers, Clobbers, RParenLoc);
219 for (unsigned i = 0; i != NumOutputs; i++) {
220 StringLiteral *Literal = Constraints[i];
221 assert(Literal->isAscii());
223 StringRef OutputName;
225 OutputName = Names[i]->getName();
227 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName);
228 if (!Context.getTargetInfo().validateOutputConstraint(Info))
229 return StmtError(Diag(Literal->getLocStart(),
230 diag::err_asm_invalid_output_constraint)
231 << Info.getConstraintStr());
233 ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
238 // Check that the output exprs are valid lvalues.
239 Expr *OutputExpr = Exprs[i];
241 // Referring to parameters is not allowed in naked functions.
242 if (CheckNakedParmReference(OutputExpr, *this))
245 // Check that the output expression is compatible with memory constraint.
246 if (Info.allowsMemory() &&
247 checkExprMemoryConstraintCompat(*this, OutputExpr, Info, false))
250 OutputConstraintInfos.push_back(Info);
252 // If this is dependent, just continue.
253 if (OutputExpr->isTypeDependent())
256 Expr::isModifiableLvalueResult IsLV =
257 OutputExpr->isModifiableLvalue(Context, /*Loc=*/nullptr);
259 case Expr::MLV_Valid:
260 // Cool, this is an lvalue.
262 case Expr::MLV_ArrayType:
265 case Expr::MLV_LValueCast: {
266 const Expr *LVal = OutputExpr->IgnoreParenNoopCasts(Context);
267 if (!getLangOpts().HeinousExtensions) {
268 Diag(LVal->getLocStart(), diag::err_invalid_asm_cast_lvalue)
269 << OutputExpr->getSourceRange();
271 Diag(LVal->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
272 << OutputExpr->getSourceRange();
274 // Accept, even if we emitted an error diagnostic.
277 case Expr::MLV_IncompleteType:
278 case Expr::MLV_IncompleteVoidType:
279 if (RequireCompleteType(OutputExpr->getLocStart(), Exprs[i]->getType(),
280 diag::err_dereference_incomplete_type))
284 return StmtError(Diag(OutputExpr->getLocStart(),
285 diag::err_asm_invalid_lvalue_in_output)
286 << OutputExpr->getSourceRange());
289 unsigned Size = Context.getTypeSize(OutputExpr->getType());
290 if (!Context.getTargetInfo().validateOutputSize(Literal->getString(),
292 return StmtError(Diag(OutputExpr->getLocStart(),
293 diag::err_asm_invalid_output_size)
294 << Info.getConstraintStr());
297 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
299 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
300 StringLiteral *Literal = Constraints[i];
301 assert(Literal->isAscii());
305 InputName = Names[i]->getName();
307 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName);
308 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos,
310 return StmtError(Diag(Literal->getLocStart(),
311 diag::err_asm_invalid_input_constraint)
312 << Info.getConstraintStr());
315 ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
320 Expr *InputExpr = Exprs[i];
322 // Referring to parameters is not allowed in naked functions.
323 if (CheckNakedParmReference(InputExpr, *this))
326 // Check that the input expression is compatible with memory constraint.
327 if (Info.allowsMemory() &&
328 checkExprMemoryConstraintCompat(*this, InputExpr, Info, true))
331 // Only allow void types for memory constraints.
332 if (Info.allowsMemory() && !Info.allowsRegister()) {
333 if (CheckAsmLValue(InputExpr, *this))
334 return StmtError(Diag(InputExpr->getLocStart(),
335 diag::err_asm_invalid_lvalue_in_input)
336 << Info.getConstraintStr()
337 << InputExpr->getSourceRange());
338 } else if (Info.requiresImmediateConstant() && !Info.allowsRegister()) {
339 if (!InputExpr->isValueDependent()) {
341 if (!InputExpr->EvaluateAsInt(Result, Context))
343 Diag(InputExpr->getLocStart(), diag::err_asm_immediate_expected)
344 << Info.getConstraintStr() << InputExpr->getSourceRange());
345 if (!Info.isValidAsmImmediate(Result))
346 return StmtError(Diag(InputExpr->getLocStart(),
347 diag::err_invalid_asm_value_for_constraint)
348 << Result.toString(10) << Info.getConstraintStr()
349 << InputExpr->getSourceRange());
353 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]);
354 if (Result.isInvalid())
357 Exprs[i] = Result.get();
360 if (Info.allowsRegister()) {
361 if (InputExpr->getType()->isVoidType()) {
362 return StmtError(Diag(InputExpr->getLocStart(),
363 diag::err_asm_invalid_type_in_input)
364 << InputExpr->getType() << Info.getConstraintStr()
365 << InputExpr->getSourceRange());
369 InputConstraintInfos.push_back(Info);
371 const Type *Ty = Exprs[i]->getType().getTypePtr();
372 if (Ty->isDependentType())
375 if (!Ty->isVoidType() || !Info.allowsMemory())
376 if (RequireCompleteType(InputExpr->getLocStart(), Exprs[i]->getType(),
377 diag::err_dereference_incomplete_type))
380 unsigned Size = Context.getTypeSize(Ty);
381 if (!Context.getTargetInfo().validateInputSize(Literal->getString(),
383 return StmtError(Diag(InputExpr->getLocStart(),
384 diag::err_asm_invalid_input_size)
385 << Info.getConstraintStr());
388 // Check that the clobbers are valid.
389 for (unsigned i = 0; i != NumClobbers; i++) {
390 StringLiteral *Literal = Clobbers[i];
391 assert(Literal->isAscii());
393 StringRef Clobber = Literal->getString();
395 if (!Context.getTargetInfo().isValidClobber(Clobber))
396 return StmtError(Diag(Literal->getLocStart(),
397 diag::err_asm_unknown_register_name) << Clobber);
401 new (Context) GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
402 NumInputs, Names, Constraints, Exprs.data(),
403 AsmString, NumClobbers, Clobbers, RParenLoc);
404 // Validate the asm string, ensuring it makes sense given the operands we
406 SmallVector<GCCAsmStmt::AsmStringPiece, 8> Pieces;
408 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) {
409 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID)
410 << AsmString->getSourceRange();
414 // Validate constraints and modifiers.
415 for (unsigned i = 0, e = Pieces.size(); i != e; ++i) {
416 GCCAsmStmt::AsmStringPiece &Piece = Pieces[i];
417 if (!Piece.isOperand()) continue;
419 // Look for the correct constraint index.
420 unsigned ConstraintIdx = Piece.getOperandNo();
421 unsigned NumOperands = NS->getNumOutputs() + NS->getNumInputs();
423 // Look for the (ConstraintIdx - NumOperands + 1)th constraint with
425 if (ConstraintIdx >= NumOperands) {
426 unsigned I = 0, E = NS->getNumOutputs();
428 for (unsigned Cnt = ConstraintIdx - NumOperands; I != E; ++I)
429 if (OutputConstraintInfos[I].isReadWrite() && Cnt-- == 0) {
434 assert(I != E && "Invalid operand number should have been caught in "
435 " AnalyzeAsmString");
438 // Now that we have the right indexes go ahead and check.
439 StringLiteral *Literal = Constraints[ConstraintIdx];
440 const Type *Ty = Exprs[ConstraintIdx]->getType().getTypePtr();
441 if (Ty->isDependentType() || Ty->isIncompleteType())
444 unsigned Size = Context.getTypeSize(Ty);
445 std::string SuggestedModifier;
446 if (!Context.getTargetInfo().validateConstraintModifier(
447 Literal->getString(), Piece.getModifier(), Size,
448 SuggestedModifier)) {
449 Diag(Exprs[ConstraintIdx]->getLocStart(),
450 diag::warn_asm_mismatched_size_modifier);
452 if (!SuggestedModifier.empty()) {
453 auto B = Diag(Piece.getRange().getBegin(),
454 diag::note_asm_missing_constraint_modifier)
455 << SuggestedModifier;
456 SuggestedModifier = "%" + SuggestedModifier + Piece.getString();
457 B.AddFixItHint(FixItHint::CreateReplacement(Piece.getRange(),
463 // Validate tied input operands for type mismatches.
464 unsigned NumAlternatives = ~0U;
465 for (unsigned i = 0, e = OutputConstraintInfos.size(); i != e; ++i) {
466 TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i];
467 StringRef ConstraintStr = Info.getConstraintStr();
468 unsigned AltCount = ConstraintStr.count(',') + 1;
469 if (NumAlternatives == ~0U)
470 NumAlternatives = AltCount;
471 else if (NumAlternatives != AltCount)
472 return StmtError(Diag(NS->getOutputExpr(i)->getLocStart(),
473 diag::err_asm_unexpected_constraint_alternatives)
474 << NumAlternatives << AltCount);
476 SmallVector<size_t, 4> InputMatchedToOutput(OutputConstraintInfos.size(),
478 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
479 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
480 StringRef ConstraintStr = Info.getConstraintStr();
481 unsigned AltCount = ConstraintStr.count(',') + 1;
482 if (NumAlternatives == ~0U)
483 NumAlternatives = AltCount;
484 else if (NumAlternatives != AltCount)
485 return StmtError(Diag(NS->getInputExpr(i)->getLocStart(),
486 diag::err_asm_unexpected_constraint_alternatives)
487 << NumAlternatives << AltCount);
489 // If this is a tied constraint, verify that the output and input have
490 // either exactly the same type, or that they are int/ptr operands with the
491 // same size (int/long, int*/long, are ok etc).
492 if (!Info.hasTiedOperand()) continue;
494 unsigned TiedTo = Info.getTiedOperand();
495 unsigned InputOpNo = i+NumOutputs;
496 Expr *OutputExpr = Exprs[TiedTo];
497 Expr *InputExpr = Exprs[InputOpNo];
499 // Make sure no more than one input constraint matches each output.
500 assert(TiedTo < InputMatchedToOutput.size() && "TiedTo value out of range");
501 if (InputMatchedToOutput[TiedTo] != ~0U) {
502 Diag(NS->getInputExpr(i)->getLocStart(),
503 diag::err_asm_input_duplicate_match)
505 Diag(NS->getInputExpr(InputMatchedToOutput[TiedTo])->getLocStart(),
506 diag::note_asm_input_duplicate_first)
510 InputMatchedToOutput[TiedTo] = i;
512 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent())
515 QualType InTy = InputExpr->getType();
516 QualType OutTy = OutputExpr->getType();
517 if (Context.hasSameType(InTy, OutTy))
518 continue; // All types can be tied to themselves.
520 // Decide if the input and output are in the same domain (integer/ptr or
523 AD_Int, AD_FP, AD_Other
524 } InputDomain, OutputDomain;
526 if (InTy->isIntegerType() || InTy->isPointerType())
527 InputDomain = AD_Int;
528 else if (InTy->isRealFloatingType())
531 InputDomain = AD_Other;
533 if (OutTy->isIntegerType() || OutTy->isPointerType())
534 OutputDomain = AD_Int;
535 else if (OutTy->isRealFloatingType())
536 OutputDomain = AD_FP;
538 OutputDomain = AD_Other;
540 // They are ok if they are the same size and in the same domain. This
541 // allows tying things like:
543 // void* to int if they are the same size.
544 // double to long double if they are the same size.
546 uint64_t OutSize = Context.getTypeSize(OutTy);
547 uint64_t InSize = Context.getTypeSize(InTy);
548 if (OutSize == InSize && InputDomain == OutputDomain &&
549 InputDomain != AD_Other)
552 // If the smaller input/output operand is not mentioned in the asm string,
553 // then we can promote the smaller one to a larger input and the asm string
555 bool SmallerValueMentioned = false;
557 // If this is a reference to the input and if the input was the smaller
558 // one, then we have to reject this asm.
559 if (isOperandMentioned(InputOpNo, Pieces)) {
560 // This is a use in the asm string of the smaller operand. Since we
561 // codegen this by promoting to a wider value, the asm will get printed
563 SmallerValueMentioned |= InSize < OutSize;
565 if (isOperandMentioned(TiedTo, Pieces)) {
566 // If this is a reference to the output, and if the output is the larger
567 // value, then it's ok because we'll promote the input to the larger type.
568 SmallerValueMentioned |= OutSize < InSize;
571 // If the smaller value wasn't mentioned in the asm string, and if the
572 // output was a register, just extend the shorter one to the size of the
574 if (!SmallerValueMentioned && InputDomain != AD_Other &&
575 OutputConstraintInfos[TiedTo].allowsRegister())
578 // Either both of the operands were mentioned or the smaller one was
579 // mentioned. One more special case that we'll allow: if the tied input is
580 // integer, unmentioned, and is a constant, then we'll allow truncating it
581 // down to the size of the destination.
582 if (InputDomain == AD_Int && OutputDomain == AD_Int &&
583 !isOperandMentioned(InputOpNo, Pieces) &&
584 InputExpr->isEvaluatable(Context)) {
586 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast);
587 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).get();
588 Exprs[InputOpNo] = InputExpr;
589 NS->setInputExpr(i, InputExpr);
593 Diag(InputExpr->getLocStart(),
594 diag::err_asm_tying_incompatible_types)
595 << InTy << OutTy << OutputExpr->getSourceRange()
596 << InputExpr->getSourceRange();
600 // Check for conflicts between clobber list and input or output lists
601 SourceLocation ConstraintLoc =
602 getClobberConflictLocation(Exprs, Constraints, Clobbers, NumClobbers,
603 Context.getTargetInfo(), Context);
604 if (ConstraintLoc.isValid())
605 return Diag(ConstraintLoc, diag::error_inoutput_conflict_with_clobber);
610 void Sema::FillInlineAsmIdentifierInfo(Expr *Res,
611 llvm::InlineAsmIdentifierInfo &Info) {
612 QualType T = Res->getType();
613 Expr::EvalResult Eval;
614 if (T->isFunctionType() || T->isDependentType())
615 return Info.setLabel(Res);
616 if (Res->isRValue()) {
617 if (isa<clang::EnumType>(T) && Res->EvaluateAsRValue(Eval, Context))
618 return Info.setEnum(Eval.Val.getInt().getSExtValue());
619 return Info.setLabel(Res);
621 unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
622 unsigned Type = Size;
623 if (const auto *ATy = Context.getAsArrayType(T))
624 Type = Context.getTypeSizeInChars(ATy->getElementType()).getQuantity();
625 bool IsGlobalLV = false;
626 if (Res->EvaluateAsLValue(Eval, Context))
627 IsGlobalLV = Eval.isGlobalLValue();
628 Info.setVar(Res, IsGlobalLV, Size, Type);
631 ExprResult Sema::LookupInlineAsmIdentifier(CXXScopeSpec &SS,
632 SourceLocation TemplateKWLoc,
634 bool IsUnevaluatedContext) {
636 if (IsUnevaluatedContext)
637 PushExpressionEvaluationContext(
638 ExpressionEvaluationContext::UnevaluatedAbstract,
639 ReuseLambdaContextDecl);
641 ExprResult Result = ActOnIdExpression(getCurScope(), SS, TemplateKWLoc, Id,
642 /*trailing lparen*/ false,
643 /*is & operand*/ false,
644 /*CorrectionCandidateCallback=*/nullptr,
645 /*IsInlineAsmIdentifier=*/ true);
647 if (IsUnevaluatedContext)
648 PopExpressionEvaluationContext();
650 if (!Result.isUsable()) return Result;
652 Result = CheckPlaceholderExpr(Result.get());
653 if (!Result.isUsable()) return Result;
655 // Referring to parameters is not allowed in naked functions.
656 if (CheckNakedParmReference(Result.get(), *this))
659 QualType T = Result.get()->getType();
661 if (T->isDependentType()) {
665 // Any sort of function type is fine.
666 if (T->isFunctionType()) {
670 // Otherwise, it needs to be a complete type.
671 if (RequireCompleteExprType(Result.get(), diag::err_asm_incomplete_type)) {
678 bool Sema::LookupInlineAsmField(StringRef Base, StringRef Member,
679 unsigned &Offset, SourceLocation AsmLoc) {
681 SmallVector<StringRef, 2> Members;
682 Member.split(Members, ".");
684 NamedDecl *FoundDecl = nullptr;
686 // MS InlineAsm uses 'this' as a base
687 if (getLangOpts().CPlusPlus && Base.equals("this")) {
688 if (const Type *PT = getCurrentThisType().getTypePtrOrNull())
689 FoundDecl = PT->getPointeeType()->getAsTagDecl();
691 LookupResult BaseResult(*this, &Context.Idents.get(Base), SourceLocation(),
693 if (LookupName(BaseResult, getCurScope()) && BaseResult.isSingleResult())
694 FoundDecl = BaseResult.getFoundDecl();
700 for (StringRef NextMember : Members) {
701 const RecordType *RT = nullptr;
702 if (VarDecl *VD = dyn_cast<VarDecl>(FoundDecl))
703 RT = VD->getType()->getAs<RecordType>();
704 else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(FoundDecl)) {
705 MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
706 // MS InlineAsm often uses struct pointer aliases as a base
707 QualType QT = TD->getUnderlyingType();
708 if (const auto *PT = QT->getAs<PointerType>())
709 QT = PT->getPointeeType();
710 RT = QT->getAs<RecordType>();
711 } else if (TypeDecl *TD = dyn_cast<TypeDecl>(FoundDecl))
712 RT = TD->getTypeForDecl()->getAs<RecordType>();
713 else if (FieldDecl *TD = dyn_cast<FieldDecl>(FoundDecl))
714 RT = TD->getType()->getAs<RecordType>();
718 if (RequireCompleteType(AsmLoc, QualType(RT, 0),
719 diag::err_asm_incomplete_type))
722 LookupResult FieldResult(*this, &Context.Idents.get(NextMember),
723 SourceLocation(), LookupMemberName);
725 if (!LookupQualifiedName(FieldResult, RT->getDecl()))
728 if (!FieldResult.isSingleResult())
730 FoundDecl = FieldResult.getFoundDecl();
732 // FIXME: Handle IndirectFieldDecl?
733 FieldDecl *FD = dyn_cast<FieldDecl>(FoundDecl);
737 const ASTRecordLayout &RL = Context.getASTRecordLayout(RT->getDecl());
738 unsigned i = FD->getFieldIndex();
739 CharUnits Result = Context.toCharUnitsFromBits(RL.getFieldOffset(i));
740 Offset += (unsigned)Result.getQuantity();
747 Sema::LookupInlineAsmVarDeclField(Expr *E, StringRef Member,
748 SourceLocation AsmLoc) {
750 QualType T = E->getType();
751 if (T->isDependentType()) {
752 DeclarationNameInfo NameInfo;
753 NameInfo.setLoc(AsmLoc);
754 NameInfo.setName(&Context.Idents.get(Member));
755 return CXXDependentScopeMemberExpr::Create(
756 Context, E, T, /*IsArrow=*/false, AsmLoc, NestedNameSpecifierLoc(),
758 /*FirstQualifierInScope=*/nullptr, NameInfo, /*TemplateArgs=*/nullptr);
761 const RecordType *RT = T->getAs<RecordType>();
762 // FIXME: Diagnose this as field access into a scalar type.
766 LookupResult FieldResult(*this, &Context.Idents.get(Member), AsmLoc,
769 if (!LookupQualifiedName(FieldResult, RT->getDecl()))
772 // Only normal and indirect field results will work.
773 ValueDecl *FD = dyn_cast<FieldDecl>(FieldResult.getFoundDecl());
775 FD = dyn_cast<IndirectFieldDecl>(FieldResult.getFoundDecl());
779 // Make an Expr to thread through OpDecl.
780 ExprResult Result = BuildMemberReferenceExpr(
781 E, E->getType(), AsmLoc, /*IsArrow=*/false, CXXScopeSpec(),
782 SourceLocation(), nullptr, FieldResult, nullptr, nullptr);
787 StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
788 ArrayRef<Token> AsmToks,
790 unsigned NumOutputs, unsigned NumInputs,
791 ArrayRef<StringRef> Constraints,
792 ArrayRef<StringRef> Clobbers,
793 ArrayRef<Expr*> Exprs,
794 SourceLocation EndLoc) {
795 bool IsSimple = (NumOutputs != 0 || NumInputs != 0);
796 getCurFunction()->setHasBranchProtectedScope();
798 new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, IsSimple,
799 /*IsVolatile*/ true, AsmToks, NumOutputs, NumInputs,
800 Constraints, Exprs, AsmString,
805 LabelDecl *Sema::GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
806 SourceLocation Location,
808 LabelDecl* Label = LookupOrCreateLabel(PP.getIdentifierInfo(ExternalLabelName),
811 if (Label->isMSAsmLabel()) {
812 // If we have previously created this label implicitly, mark it as used.
813 Label->markUsed(Context);
815 // Otherwise, insert it, but only resolve it if we have seen the label itself.
816 std::string InternalName;
817 llvm::raw_string_ostream OS(InternalName);
818 // Create an internal name for the label. The name should not be a valid
819 // mangled name, and should be unique. We use a dot to make the name an
820 // invalid mangled name. We use LLVM's inline asm ${:uid} escape so that a
821 // unique label is generated each time this blob is emitted, even after
823 OS << "__MSASMLABEL_.${:uid}__";
824 for (char C : ExternalLabelName) {
826 // We escape '$' in asm strings by replacing it with "$$"
830 Label->setMSAsmLabel(OS.str());
833 // The label might have been created implicitly from a previously encountered
834 // goto statement. So, for both newly created and looked up labels, we mark
836 Label->setMSAsmLabelResolved();
838 // Adjust their location for being able to generate accurate diagnostics.
839 Label->setLocation(Location);