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 /// Remove the upper-level LValueToRValue cast from an expression.
31 static void removeLValueToRValueCast(Expr *E) {
33 Expr *ExprUnderCast = nullptr;
34 SmallVector<Expr *, 8> ParentsToUpdate;
37 ParentsToUpdate.push_back(Parent);
38 if (auto *ParenE = dyn_cast<ParenExpr>(Parent)) {
39 Parent = ParenE->getSubExpr();
43 Expr *Child = nullptr;
44 CastExpr *ParentCast = dyn_cast<CastExpr>(Parent);
46 Child = ParentCast->getSubExpr();
50 if (auto *CastE = dyn_cast<CastExpr>(Child))
51 if (CastE->getCastKind() == CK_LValueToRValue) {
52 ExprUnderCast = CastE->getSubExpr();
53 // LValueToRValue cast inside GCCAsmStmt requires an explicit cast.
54 ParentCast->setSubExpr(ExprUnderCast);
60 // Update parent expressions to have same ValueType as the underlying.
61 assert(ExprUnderCast &&
62 "Should be reachable only if LValueToRValue cast was found!");
63 auto ValueKind = ExprUnderCast->getValueKind();
64 for (Expr *E : ParentsToUpdate)
65 E->setValueKind(ValueKind);
68 /// Emit a warning about usage of "noop"-like casts for lvalues (GNU extension)
69 /// and fix the argument with removing LValueToRValue cast from the expression.
70 static void emitAndFixInvalidAsmCastLValue(const Expr *LVal, Expr *BadArgument,
72 if (!S.getLangOpts().HeinousExtensions) {
73 S.Diag(LVal->getBeginLoc(), diag::err_invalid_asm_cast_lvalue)
74 << BadArgument->getSourceRange();
76 S.Diag(LVal->getBeginLoc(), diag::warn_invalid_asm_cast_lvalue)
77 << BadArgument->getSourceRange();
79 removeLValueToRValueCast(BadArgument);
82 /// CheckAsmLValue - GNU C has an extremely ugly extension whereby they silently
83 /// ignore "noop" casts in places where an lvalue is required by an inline asm.
84 /// We emulate this behavior when -fheinous-gnu-extensions is specified, but
85 /// provide a strong guidance to not use it.
87 /// This method checks to see if the argument is an acceptable l-value and
88 /// returns false if it is a case we can handle.
89 static bool CheckAsmLValue(Expr *E, Sema &S) {
90 // Type dependent expressions will be checked during instantiation.
91 if (E->isTypeDependent())
95 return false; // Cool, this is an lvalue.
97 // Okay, this is not an lvalue, but perhaps it is the result of a cast that we
98 // are supposed to allow.
99 const Expr *E2 = E->IgnoreParenNoopCasts(S.Context);
100 if (E != E2 && E2->isLValue()) {
101 emitAndFixInvalidAsmCastLValue(E2, E, S);
102 // Accept, even if we emitted an error diagnostic.
106 // None of the above, just randomly invalid non-lvalue.
110 /// isOperandMentioned - Return true if the specified operand # is mentioned
111 /// anywhere in the decomposed asm string.
113 isOperandMentioned(unsigned OpNo,
114 ArrayRef<GCCAsmStmt::AsmStringPiece> AsmStrPieces) {
115 for (unsigned p = 0, e = AsmStrPieces.size(); p != e; ++p) {
116 const GCCAsmStmt::AsmStringPiece &Piece = AsmStrPieces[p];
117 if (!Piece.isOperand())
120 // If this is a reference to the input and if the input was the smaller
121 // one, then we have to reject this asm.
122 if (Piece.getOperandNo() == OpNo)
128 static bool CheckNakedParmReference(Expr *E, Sema &S) {
129 FunctionDecl *Func = dyn_cast<FunctionDecl>(S.CurContext);
132 if (!Func->hasAttr<NakedAttr>())
135 SmallVector<Expr*, 4> WorkList;
136 WorkList.push_back(E);
137 while (WorkList.size()) {
138 Expr *E = WorkList.pop_back_val();
139 if (isa<CXXThisExpr>(E)) {
140 S.Diag(E->getBeginLoc(), diag::err_asm_naked_this_ref);
141 S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
144 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
145 if (isa<ParmVarDecl>(DRE->getDecl())) {
146 S.Diag(DRE->getBeginLoc(), diag::err_asm_naked_parm_ref);
147 S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
151 for (Stmt *Child : E->children()) {
152 if (Expr *E = dyn_cast_or_null<Expr>(Child))
153 WorkList.push_back(E);
159 /// Returns true if given expression is not compatible with inline
160 /// assembly's memory constraint; false otherwise.
161 static bool checkExprMemoryConstraintCompat(Sema &S, Expr *E,
162 TargetInfo::ConstraintInfo &Info,
163 bool is_input_expr) {
169 } EType = ExprSafeType;
171 // Bitfields, vector elements and global register variables are not
173 if (E->refersToBitField())
174 EType = ExprBitfield;
175 else if (E->refersToVectorElement())
176 EType = ExprVectorElt;
177 else if (E->refersToGlobalRegisterVar())
178 EType = ExprGlobalRegVar;
180 if (EType != ExprSafeType) {
181 S.Diag(E->getBeginLoc(), diag::err_asm_non_addr_value_in_memory_constraint)
182 << EType << is_input_expr << Info.getConstraintStr()
183 << E->getSourceRange();
190 // Extracting the register name from the Expression value,
191 // if there is no register name to extract, returns ""
192 static StringRef extractRegisterName(const Expr *Expression,
193 const TargetInfo &Target) {
194 Expression = Expression->IgnoreImpCasts();
195 if (const DeclRefExpr *AsmDeclRef = dyn_cast<DeclRefExpr>(Expression)) {
196 // Handle cases where the expression is a variable
197 const VarDecl *Variable = dyn_cast<VarDecl>(AsmDeclRef->getDecl());
198 if (Variable && Variable->getStorageClass() == SC_Register) {
199 if (AsmLabelAttr *Attr = Variable->getAttr<AsmLabelAttr>())
200 if (Target.isValidGCCRegisterName(Attr->getLabel()))
201 return Target.getNormalizedGCCRegisterName(Attr->getLabel(), true);
207 // Checks if there is a conflict between the input and output lists with the
208 // clobbers list. If there's a conflict, returns the location of the
209 // conflicted clobber, else returns nullptr
210 static SourceLocation
211 getClobberConflictLocation(MultiExprArg Exprs, StringLiteral **Constraints,
212 StringLiteral **Clobbers, int NumClobbers,
213 const TargetInfo &Target, ASTContext &Cont) {
214 llvm::StringSet<> InOutVars;
215 // Collect all the input and output registers from the extended asm
216 // statement in order to check for conflicts with the clobber list
217 for (unsigned int i = 0; i < Exprs.size(); ++i) {
218 StringRef Constraint = Constraints[i]->getString();
219 StringRef InOutReg = Target.getConstraintRegister(
220 Constraint, extractRegisterName(Exprs[i], Target));
222 InOutVars.insert(InOutReg);
224 // Check for each item in the clobber list if it conflicts with the input
226 for (int i = 0; i < NumClobbers; ++i) {
227 StringRef Clobber = Clobbers[i]->getString();
228 // We only check registers, therefore we don't check cc and memory
230 if (Clobber == "cc" || Clobber == "memory")
232 Clobber = Target.getNormalizedGCCRegisterName(Clobber, true);
233 // Go over the output's registers we collected
234 if (InOutVars.count(Clobber))
235 return Clobbers[i]->getBeginLoc();
237 return SourceLocation();
240 StmtResult Sema::ActOnGCCAsmStmt(SourceLocation AsmLoc, bool IsSimple,
241 bool IsVolatile, unsigned NumOutputs,
242 unsigned NumInputs, IdentifierInfo **Names,
243 MultiExprArg constraints, MultiExprArg Exprs,
244 Expr *asmString, MultiExprArg clobbers,
245 SourceLocation RParenLoc) {
246 unsigned NumClobbers = clobbers.size();
247 StringLiteral **Constraints =
248 reinterpret_cast<StringLiteral**>(constraints.data());
249 StringLiteral *AsmString = cast<StringLiteral>(asmString);
250 StringLiteral **Clobbers = reinterpret_cast<StringLiteral**>(clobbers.data());
252 SmallVector<TargetInfo::ConstraintInfo, 4> OutputConstraintInfos;
254 // The parser verifies that there is a string literal here.
255 assert(AsmString->isAscii());
257 // If we're compiling CUDA file and function attributes indicate that it's not
258 // for this compilation side, skip all the checks.
259 if (!DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl())) {
260 GCCAsmStmt *NS = new (Context) GCCAsmStmt(
261 Context, AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, Names,
262 Constraints, Exprs.data(), AsmString, NumClobbers, Clobbers, RParenLoc);
266 for (unsigned i = 0; i != NumOutputs; i++) {
267 StringLiteral *Literal = Constraints[i];
268 assert(Literal->isAscii());
270 StringRef OutputName;
272 OutputName = Names[i]->getName();
274 TargetInfo::ConstraintInfo Info(Literal->getString(), OutputName);
275 if (!Context.getTargetInfo().validateOutputConstraint(Info))
277 Diag(Literal->getBeginLoc(), diag::err_asm_invalid_output_constraint)
278 << Info.getConstraintStr());
280 ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
285 // Check that the output exprs are valid lvalues.
286 Expr *OutputExpr = Exprs[i];
288 // Referring to parameters is not allowed in naked functions.
289 if (CheckNakedParmReference(OutputExpr, *this))
292 // Check that the output expression is compatible with memory constraint.
293 if (Info.allowsMemory() &&
294 checkExprMemoryConstraintCompat(*this, OutputExpr, Info, false))
297 OutputConstraintInfos.push_back(Info);
299 // If this is dependent, just continue.
300 if (OutputExpr->isTypeDependent())
303 Expr::isModifiableLvalueResult IsLV =
304 OutputExpr->isModifiableLvalue(Context, /*Loc=*/nullptr);
306 case Expr::MLV_Valid:
307 // Cool, this is an lvalue.
309 case Expr::MLV_ArrayType:
312 case Expr::MLV_LValueCast: {
313 const Expr *LVal = OutputExpr->IgnoreParenNoopCasts(Context);
314 emitAndFixInvalidAsmCastLValue(LVal, OutputExpr, *this);
315 // Accept, even if we emitted an error diagnostic.
318 case Expr::MLV_IncompleteType:
319 case Expr::MLV_IncompleteVoidType:
320 if (RequireCompleteType(OutputExpr->getBeginLoc(), Exprs[i]->getType(),
321 diag::err_dereference_incomplete_type))
325 return StmtError(Diag(OutputExpr->getBeginLoc(),
326 diag::err_asm_invalid_lvalue_in_output)
327 << OutputExpr->getSourceRange());
330 unsigned Size = Context.getTypeSize(OutputExpr->getType());
331 if (!Context.getTargetInfo().validateOutputSize(Literal->getString(),
334 Diag(OutputExpr->getBeginLoc(), diag::err_asm_invalid_output_size)
335 << Info.getConstraintStr());
338 SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
340 for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
341 StringLiteral *Literal = Constraints[i];
342 assert(Literal->isAscii());
346 InputName = Names[i]->getName();
348 TargetInfo::ConstraintInfo Info(Literal->getString(), InputName);
349 if (!Context.getTargetInfo().validateInputConstraint(OutputConstraintInfos,
352 Diag(Literal->getBeginLoc(), diag::err_asm_invalid_input_constraint)
353 << Info.getConstraintStr());
356 ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
361 Expr *InputExpr = Exprs[i];
363 // Referring to parameters is not allowed in naked functions.
364 if (CheckNakedParmReference(InputExpr, *this))
367 // Check that the input expression is compatible with memory constraint.
368 if (Info.allowsMemory() &&
369 checkExprMemoryConstraintCompat(*this, InputExpr, Info, true))
372 // Only allow void types for memory constraints.
373 if (Info.allowsMemory() && !Info.allowsRegister()) {
374 if (CheckAsmLValue(InputExpr, *this))
375 return StmtError(Diag(InputExpr->getBeginLoc(),
376 diag::err_asm_invalid_lvalue_in_input)
377 << Info.getConstraintStr()
378 << InputExpr->getSourceRange());
379 } else if (Info.requiresImmediateConstant() && !Info.allowsRegister()) {
380 if (!InputExpr->isValueDependent()) {
381 Expr::EvalResult EVResult;
382 if (!InputExpr->EvaluateAsRValue(EVResult, Context, true))
384 Diag(InputExpr->getBeginLoc(), diag::err_asm_immediate_expected)
385 << Info.getConstraintStr() << InputExpr->getSourceRange());
387 // For compatibility with GCC, we also allow pointers that would be
388 // integral constant expressions if they were cast to int.
389 llvm::APSInt IntResult;
390 if (!EVResult.Val.toIntegralConstant(IntResult, InputExpr->getType(),
393 Diag(InputExpr->getBeginLoc(), diag::err_asm_immediate_expected)
394 << Info.getConstraintStr() << InputExpr->getSourceRange());
396 if (!Info.isValidAsmImmediate(IntResult))
397 return StmtError(Diag(InputExpr->getBeginLoc(),
398 diag::err_invalid_asm_value_for_constraint)
399 << IntResult.toString(10) << Info.getConstraintStr()
400 << InputExpr->getSourceRange());
404 ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]);
405 if (Result.isInvalid())
408 Exprs[i] = Result.get();
411 if (Info.allowsRegister()) {
412 if (InputExpr->getType()->isVoidType()) {
414 Diag(InputExpr->getBeginLoc(), diag::err_asm_invalid_type_in_input)
415 << InputExpr->getType() << Info.getConstraintStr()
416 << InputExpr->getSourceRange());
420 InputConstraintInfos.push_back(Info);
422 const Type *Ty = Exprs[i]->getType().getTypePtr();
423 if (Ty->isDependentType())
426 if (!Ty->isVoidType() || !Info.allowsMemory())
427 if (RequireCompleteType(InputExpr->getBeginLoc(), Exprs[i]->getType(),
428 diag::err_dereference_incomplete_type))
431 unsigned Size = Context.getTypeSize(Ty);
432 if (!Context.getTargetInfo().validateInputSize(Literal->getString(),
435 Diag(InputExpr->getBeginLoc(), diag::err_asm_invalid_input_size)
436 << Info.getConstraintStr());
439 // Check that the clobbers are valid.
440 for (unsigned i = 0; i != NumClobbers; i++) {
441 StringLiteral *Literal = Clobbers[i];
442 assert(Literal->isAscii());
444 StringRef Clobber = Literal->getString();
446 if (!Context.getTargetInfo().isValidClobber(Clobber))
448 Diag(Literal->getBeginLoc(), diag::err_asm_unknown_register_name)
453 new (Context) GCCAsmStmt(Context, AsmLoc, IsSimple, IsVolatile, NumOutputs,
454 NumInputs, Names, Constraints, Exprs.data(),
455 AsmString, NumClobbers, Clobbers, RParenLoc);
456 // Validate the asm string, ensuring it makes sense given the operands we
458 SmallVector<GCCAsmStmt::AsmStringPiece, 8> Pieces;
460 if (unsigned DiagID = NS->AnalyzeAsmString(Pieces, Context, DiagOffs)) {
461 Diag(getLocationOfStringLiteralByte(AsmString, DiagOffs), DiagID)
462 << AsmString->getSourceRange();
466 // Validate constraints and modifiers.
467 for (unsigned i = 0, e = Pieces.size(); i != e; ++i) {
468 GCCAsmStmt::AsmStringPiece &Piece = Pieces[i];
469 if (!Piece.isOperand()) continue;
471 // Look for the correct constraint index.
472 unsigned ConstraintIdx = Piece.getOperandNo();
473 unsigned NumOperands = NS->getNumOutputs() + NS->getNumInputs();
475 // Look for the (ConstraintIdx - NumOperands + 1)th constraint with
477 if (ConstraintIdx >= NumOperands) {
478 unsigned I = 0, E = NS->getNumOutputs();
480 for (unsigned Cnt = ConstraintIdx - NumOperands; I != E; ++I)
481 if (OutputConstraintInfos[I].isReadWrite() && Cnt-- == 0) {
486 assert(I != E && "Invalid operand number should have been caught in "
487 " AnalyzeAsmString");
490 // Now that we have the right indexes go ahead and check.
491 StringLiteral *Literal = Constraints[ConstraintIdx];
492 const Type *Ty = Exprs[ConstraintIdx]->getType().getTypePtr();
493 if (Ty->isDependentType() || Ty->isIncompleteType())
496 unsigned Size = Context.getTypeSize(Ty);
497 std::string SuggestedModifier;
498 if (!Context.getTargetInfo().validateConstraintModifier(
499 Literal->getString(), Piece.getModifier(), Size,
500 SuggestedModifier)) {
501 Diag(Exprs[ConstraintIdx]->getBeginLoc(),
502 diag::warn_asm_mismatched_size_modifier);
504 if (!SuggestedModifier.empty()) {
505 auto B = Diag(Piece.getRange().getBegin(),
506 diag::note_asm_missing_constraint_modifier)
507 << SuggestedModifier;
508 SuggestedModifier = "%" + SuggestedModifier + Piece.getString();
509 B.AddFixItHint(FixItHint::CreateReplacement(Piece.getRange(),
515 // Validate tied input operands for type mismatches.
516 unsigned NumAlternatives = ~0U;
517 for (unsigned i = 0, e = OutputConstraintInfos.size(); i != e; ++i) {
518 TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i];
519 StringRef ConstraintStr = Info.getConstraintStr();
520 unsigned AltCount = ConstraintStr.count(',') + 1;
521 if (NumAlternatives == ~0U)
522 NumAlternatives = AltCount;
523 else if (NumAlternatives != AltCount)
524 return StmtError(Diag(NS->getOutputExpr(i)->getBeginLoc(),
525 diag::err_asm_unexpected_constraint_alternatives)
526 << NumAlternatives << AltCount);
528 SmallVector<size_t, 4> InputMatchedToOutput(OutputConstraintInfos.size(),
530 for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
531 TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
532 StringRef ConstraintStr = Info.getConstraintStr();
533 unsigned AltCount = ConstraintStr.count(',') + 1;
534 if (NumAlternatives == ~0U)
535 NumAlternatives = AltCount;
536 else if (NumAlternatives != AltCount)
537 return StmtError(Diag(NS->getInputExpr(i)->getBeginLoc(),
538 diag::err_asm_unexpected_constraint_alternatives)
539 << NumAlternatives << AltCount);
541 // If this is a tied constraint, verify that the output and input have
542 // either exactly the same type, or that they are int/ptr operands with the
543 // same size (int/long, int*/long, are ok etc).
544 if (!Info.hasTiedOperand()) continue;
546 unsigned TiedTo = Info.getTiedOperand();
547 unsigned InputOpNo = i+NumOutputs;
548 Expr *OutputExpr = Exprs[TiedTo];
549 Expr *InputExpr = Exprs[InputOpNo];
551 // Make sure no more than one input constraint matches each output.
552 assert(TiedTo < InputMatchedToOutput.size() && "TiedTo value out of range");
553 if (InputMatchedToOutput[TiedTo] != ~0U) {
554 Diag(NS->getInputExpr(i)->getBeginLoc(),
555 diag::err_asm_input_duplicate_match)
557 Diag(NS->getInputExpr(InputMatchedToOutput[TiedTo])->getBeginLoc(),
558 diag::note_asm_input_duplicate_first)
562 InputMatchedToOutput[TiedTo] = i;
564 if (OutputExpr->isTypeDependent() || InputExpr->isTypeDependent())
567 QualType InTy = InputExpr->getType();
568 QualType OutTy = OutputExpr->getType();
569 if (Context.hasSameType(InTy, OutTy))
570 continue; // All types can be tied to themselves.
572 // Decide if the input and output are in the same domain (integer/ptr or
575 AD_Int, AD_FP, AD_Other
576 } InputDomain, OutputDomain;
578 if (InTy->isIntegerType() || InTy->isPointerType())
579 InputDomain = AD_Int;
580 else if (InTy->isRealFloatingType())
583 InputDomain = AD_Other;
585 if (OutTy->isIntegerType() || OutTy->isPointerType())
586 OutputDomain = AD_Int;
587 else if (OutTy->isRealFloatingType())
588 OutputDomain = AD_FP;
590 OutputDomain = AD_Other;
592 // They are ok if they are the same size and in the same domain. This
593 // allows tying things like:
595 // void* to int if they are the same size.
596 // double to long double if they are the same size.
598 uint64_t OutSize = Context.getTypeSize(OutTy);
599 uint64_t InSize = Context.getTypeSize(InTy);
600 if (OutSize == InSize && InputDomain == OutputDomain &&
601 InputDomain != AD_Other)
604 // If the smaller input/output operand is not mentioned in the asm string,
605 // then we can promote the smaller one to a larger input and the asm string
607 bool SmallerValueMentioned = false;
609 // If this is a reference to the input and if the input was the smaller
610 // one, then we have to reject this asm.
611 if (isOperandMentioned(InputOpNo, Pieces)) {
612 // This is a use in the asm string of the smaller operand. Since we
613 // codegen this by promoting to a wider value, the asm will get printed
615 SmallerValueMentioned |= InSize < OutSize;
617 if (isOperandMentioned(TiedTo, Pieces)) {
618 // If this is a reference to the output, and if the output is the larger
619 // value, then it's ok because we'll promote the input to the larger type.
620 SmallerValueMentioned |= OutSize < InSize;
623 // If the smaller value wasn't mentioned in the asm string, and if the
624 // output was a register, just extend the shorter one to the size of the
626 if (!SmallerValueMentioned && InputDomain != AD_Other &&
627 OutputConstraintInfos[TiedTo].allowsRegister())
630 // Either both of the operands were mentioned or the smaller one was
631 // mentioned. One more special case that we'll allow: if the tied input is
632 // integer, unmentioned, and is a constant, then we'll allow truncating it
633 // down to the size of the destination.
634 if (InputDomain == AD_Int && OutputDomain == AD_Int &&
635 !isOperandMentioned(InputOpNo, Pieces) &&
636 InputExpr->isEvaluatable(Context)) {
638 (OutTy->isBooleanType() ? CK_IntegralToBoolean : CK_IntegralCast);
639 InputExpr = ImpCastExprToType(InputExpr, OutTy, castKind).get();
640 Exprs[InputOpNo] = InputExpr;
641 NS->setInputExpr(i, InputExpr);
645 Diag(InputExpr->getBeginLoc(), diag::err_asm_tying_incompatible_types)
646 << InTy << OutTy << OutputExpr->getSourceRange()
647 << InputExpr->getSourceRange();
651 // Check for conflicts between clobber list and input or output lists
652 SourceLocation ConstraintLoc =
653 getClobberConflictLocation(Exprs, Constraints, Clobbers, NumClobbers,
654 Context.getTargetInfo(), Context);
655 if (ConstraintLoc.isValid())
656 return Diag(ConstraintLoc, diag::error_inoutput_conflict_with_clobber);
661 void Sema::FillInlineAsmIdentifierInfo(Expr *Res,
662 llvm::InlineAsmIdentifierInfo &Info) {
663 QualType T = Res->getType();
664 Expr::EvalResult Eval;
665 if (T->isFunctionType() || T->isDependentType())
666 return Info.setLabel(Res);
667 if (Res->isRValue()) {
668 if (isa<clang::EnumType>(T) && Res->EvaluateAsRValue(Eval, Context))
669 return Info.setEnum(Eval.Val.getInt().getSExtValue());
670 return Info.setLabel(Res);
672 unsigned Size = Context.getTypeSizeInChars(T).getQuantity();
673 unsigned Type = Size;
674 if (const auto *ATy = Context.getAsArrayType(T))
675 Type = Context.getTypeSizeInChars(ATy->getElementType()).getQuantity();
676 bool IsGlobalLV = false;
677 if (Res->EvaluateAsLValue(Eval, Context))
678 IsGlobalLV = Eval.isGlobalLValue();
679 Info.setVar(Res, IsGlobalLV, Size, Type);
682 ExprResult Sema::LookupInlineAsmIdentifier(CXXScopeSpec &SS,
683 SourceLocation TemplateKWLoc,
685 bool IsUnevaluatedContext) {
687 if (IsUnevaluatedContext)
688 PushExpressionEvaluationContext(
689 ExpressionEvaluationContext::UnevaluatedAbstract,
690 ReuseLambdaContextDecl);
692 ExprResult Result = ActOnIdExpression(getCurScope(), SS, TemplateKWLoc, Id,
693 /*trailing lparen*/ false,
694 /*is & operand*/ false,
695 /*CorrectionCandidateCallback=*/nullptr,
696 /*IsInlineAsmIdentifier=*/ true);
698 if (IsUnevaluatedContext)
699 PopExpressionEvaluationContext();
701 if (!Result.isUsable()) return Result;
703 Result = CheckPlaceholderExpr(Result.get());
704 if (!Result.isUsable()) return Result;
706 // Referring to parameters is not allowed in naked functions.
707 if (CheckNakedParmReference(Result.get(), *this))
710 QualType T = Result.get()->getType();
712 if (T->isDependentType()) {
716 // Any sort of function type is fine.
717 if (T->isFunctionType()) {
721 // Otherwise, it needs to be a complete type.
722 if (RequireCompleteExprType(Result.get(), diag::err_asm_incomplete_type)) {
729 bool Sema::LookupInlineAsmField(StringRef Base, StringRef Member,
730 unsigned &Offset, SourceLocation AsmLoc) {
732 SmallVector<StringRef, 2> Members;
733 Member.split(Members, ".");
735 NamedDecl *FoundDecl = nullptr;
737 // MS InlineAsm uses 'this' as a base
738 if (getLangOpts().CPlusPlus && Base.equals("this")) {
739 if (const Type *PT = getCurrentThisType().getTypePtrOrNull())
740 FoundDecl = PT->getPointeeType()->getAsTagDecl();
742 LookupResult BaseResult(*this, &Context.Idents.get(Base), SourceLocation(),
744 if (LookupName(BaseResult, getCurScope()) && BaseResult.isSingleResult())
745 FoundDecl = BaseResult.getFoundDecl();
751 for (StringRef NextMember : Members) {
752 const RecordType *RT = nullptr;
753 if (VarDecl *VD = dyn_cast<VarDecl>(FoundDecl))
754 RT = VD->getType()->getAs<RecordType>();
755 else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(FoundDecl)) {
756 MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
757 // MS InlineAsm often uses struct pointer aliases as a base
758 QualType QT = TD->getUnderlyingType();
759 if (const auto *PT = QT->getAs<PointerType>())
760 QT = PT->getPointeeType();
761 RT = QT->getAs<RecordType>();
762 } else if (TypeDecl *TD = dyn_cast<TypeDecl>(FoundDecl))
763 RT = TD->getTypeForDecl()->getAs<RecordType>();
764 else if (FieldDecl *TD = dyn_cast<FieldDecl>(FoundDecl))
765 RT = TD->getType()->getAs<RecordType>();
769 if (RequireCompleteType(AsmLoc, QualType(RT, 0),
770 diag::err_asm_incomplete_type))
773 LookupResult FieldResult(*this, &Context.Idents.get(NextMember),
774 SourceLocation(), LookupMemberName);
776 if (!LookupQualifiedName(FieldResult, RT->getDecl()))
779 if (!FieldResult.isSingleResult())
781 FoundDecl = FieldResult.getFoundDecl();
783 // FIXME: Handle IndirectFieldDecl?
784 FieldDecl *FD = dyn_cast<FieldDecl>(FoundDecl);
788 const ASTRecordLayout &RL = Context.getASTRecordLayout(RT->getDecl());
789 unsigned i = FD->getFieldIndex();
790 CharUnits Result = Context.toCharUnitsFromBits(RL.getFieldOffset(i));
791 Offset += (unsigned)Result.getQuantity();
798 Sema::LookupInlineAsmVarDeclField(Expr *E, StringRef Member,
799 SourceLocation AsmLoc) {
801 QualType T = E->getType();
802 if (T->isDependentType()) {
803 DeclarationNameInfo NameInfo;
804 NameInfo.setLoc(AsmLoc);
805 NameInfo.setName(&Context.Idents.get(Member));
806 return CXXDependentScopeMemberExpr::Create(
807 Context, E, T, /*IsArrow=*/false, AsmLoc, NestedNameSpecifierLoc(),
809 /*FirstQualifierInScope=*/nullptr, NameInfo, /*TemplateArgs=*/nullptr);
812 const RecordType *RT = T->getAs<RecordType>();
813 // FIXME: Diagnose this as field access into a scalar type.
817 LookupResult FieldResult(*this, &Context.Idents.get(Member), AsmLoc,
820 if (!LookupQualifiedName(FieldResult, RT->getDecl()))
823 // Only normal and indirect field results will work.
824 ValueDecl *FD = dyn_cast<FieldDecl>(FieldResult.getFoundDecl());
826 FD = dyn_cast<IndirectFieldDecl>(FieldResult.getFoundDecl());
830 // Make an Expr to thread through OpDecl.
831 ExprResult Result = BuildMemberReferenceExpr(
832 E, E->getType(), AsmLoc, /*IsArrow=*/false, CXXScopeSpec(),
833 SourceLocation(), nullptr, FieldResult, nullptr, nullptr);
838 StmtResult Sema::ActOnMSAsmStmt(SourceLocation AsmLoc, SourceLocation LBraceLoc,
839 ArrayRef<Token> AsmToks,
841 unsigned NumOutputs, unsigned NumInputs,
842 ArrayRef<StringRef> Constraints,
843 ArrayRef<StringRef> Clobbers,
844 ArrayRef<Expr*> Exprs,
845 SourceLocation EndLoc) {
846 bool IsSimple = (NumOutputs != 0 || NumInputs != 0);
847 setFunctionHasBranchProtectedScope();
849 new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, IsSimple,
850 /*IsVolatile*/ true, AsmToks, NumOutputs, NumInputs,
851 Constraints, Exprs, AsmString,
856 LabelDecl *Sema::GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
857 SourceLocation Location,
859 LabelDecl* Label = LookupOrCreateLabel(PP.getIdentifierInfo(ExternalLabelName),
862 if (Label->isMSAsmLabel()) {
863 // If we have previously created this label implicitly, mark it as used.
864 Label->markUsed(Context);
866 // Otherwise, insert it, but only resolve it if we have seen the label itself.
867 std::string InternalName;
868 llvm::raw_string_ostream OS(InternalName);
869 // Create an internal name for the label. The name should not be a valid
870 // mangled name, and should be unique. We use a dot to make the name an
871 // invalid mangled name. We use LLVM's inline asm ${:uid} escape so that a
872 // unique label is generated each time this blob is emitted, even after
874 OS << "__MSASMLABEL_.${:uid}__";
875 for (char C : ExternalLabelName) {
877 // We escape '$' in asm strings by replacing it with "$$"
881 Label->setMSAsmLabel(OS.str());
884 // The label might have been created implicitly from a previously encountered
885 // goto statement. So, for both newly created and looked up labels, we mark
887 Label->setMSAsmLabelResolved();
889 // Adjust their location for being able to generate accurate diagnostics.
890 Label->setLocation(Location);