llvm-project/clang/lib/Sema/SemaStmtAsm.cpp
Alexander Musman 8e261be911 Fix assertion in inline assembler IR gen
Several inputs may not refer to one output constraint in inline assembler
insertions, clang was failing on assertion on such test case.

llvm-svn: 248158
2015-09-21 14:41:00 +00:00

754 lines
28 KiB
C++

//===--- 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/ExprCXX.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"
#include "llvm/MC/MCParser/MCAsmParser.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;
}
static bool CheckNakedParmReference(Expr *E, Sema &S) {
FunctionDecl *Func = dyn_cast<FunctionDecl>(S.CurContext);
if (!Func)
return false;
if (!Func->hasAttr<NakedAttr>())
return false;
SmallVector<Expr*, 4> WorkList;
WorkList.push_back(E);
while (WorkList.size()) {
Expr *E = WorkList.pop_back_val();
if (isa<CXXThisExpr>(E)) {
S.Diag(E->getLocStart(), diag::err_asm_naked_this_ref);
S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
return true;
}
if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
if (isa<ParmVarDecl>(DRE->getDecl())) {
S.Diag(DRE->getLocStart(), diag::err_asm_naked_parm_ref);
S.Diag(Func->getAttr<NakedAttr>()->getLocation(), diag::note_attribute);
return true;
}
}
for (Stmt *Child : E->children()) {
if (Expr *E = dyn_cast_or_null<Expr>(Child))
WorkList.push_back(E);
}
}
return false;
}
/// \brief Returns true if given expression is not compatible with inline
/// assembly's memory constraint; false otherwise.
static bool checkExprMemoryConstraintCompat(Sema &S, Expr *E,
TargetInfo::ConstraintInfo &Info,
bool is_input_expr) {
enum {
ExprBitfield = 0,
ExprVectorElt,
ExprGlobalRegVar,
ExprSafeType
} EType = ExprSafeType;
// Bitfields, vector elements and global register variables are not
// compatible.
if (E->refersToBitField())
EType = ExprBitfield;
else if (E->refersToVectorElement())
EType = ExprVectorElt;
else if (E->refersToGlobalRegisterVar())
EType = ExprGlobalRegVar;
if (EType != ExprSafeType) {
S.Diag(E->getLocStart(), diag::err_asm_non_addr_value_in_memory_constraint)
<< EType << is_input_expr << Info.getConstraintStr()
<< E->getSourceRange();
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.
assert(AsmString->isAscii());
// If we're compiling CUDA file and function attributes indicate that it's not
// for this compilation side, skip all the checks.
if (!DeclAttrsMatchCUDAMode(getLangOpts(), getCurFunctionDecl())) {
GCCAsmStmt *NS = new (Context) GCCAsmStmt(
Context, AsmLoc, IsSimple, IsVolatile, NumOutputs, NumInputs, Names,
Constraints, Exprs.data(), AsmString, NumClobbers, Clobbers, RParenLoc);
return NS;
}
for (unsigned i = 0; i != NumOutputs; i++) {
StringLiteral *Literal = Constraints[i];
assert(Literal->isAscii());
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());
ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
if (ER.isInvalid())
return StmtError();
Exprs[i] = ER.get();
// Check that the output exprs are valid lvalues.
Expr *OutputExpr = Exprs[i];
// Referring to parameters is not allowed in naked functions.
if (CheckNakedParmReference(OutputExpr, *this))
return StmtError();
// Check that the output expression is compatible with memory constraint.
if (Info.allowsMemory() &&
checkExprMemoryConstraintCompat(*this, OutputExpr, Info, false))
return StmtError();
OutputConstraintInfos.push_back(Info);
// If this is dependent, just continue.
if (OutputExpr->isTypeDependent())
continue;
Expr::isModifiableLvalueResult IsLV =
OutputExpr->isModifiableLvalue(Context, /*Loc=*/nullptr);
switch (IsLV) {
case Expr::MLV_Valid:
// Cool, this is an lvalue.
break;
case Expr::MLV_ArrayType:
// This is OK too.
break;
case Expr::MLV_LValueCast: {
const Expr *LVal = OutputExpr->IgnoreParenNoopCasts(Context);
if (!getLangOpts().HeinousExtensions) {
Diag(LVal->getLocStart(), diag::err_invalid_asm_cast_lvalue)
<< OutputExpr->getSourceRange();
} else {
Diag(LVal->getLocStart(), diag::warn_invalid_asm_cast_lvalue)
<< OutputExpr->getSourceRange();
}
// Accept, even if we emitted an error diagnostic.
break;
}
case Expr::MLV_IncompleteType:
case Expr::MLV_IncompleteVoidType:
if (RequireCompleteType(OutputExpr->getLocStart(), Exprs[i]->getType(),
diag::err_dereference_incomplete_type))
return StmtError();
default:
return StmtError(Diag(OutputExpr->getLocStart(),
diag::err_asm_invalid_lvalue_in_output)
<< OutputExpr->getSourceRange());
}
unsigned Size = Context.getTypeSize(OutputExpr->getType());
if (!Context.getTargetInfo().validateOutputSize(Literal->getString(),
Size))
return StmtError(Diag(OutputExpr->getLocStart(),
diag::err_asm_invalid_output_size)
<< Info.getConstraintStr());
}
SmallVector<TargetInfo::ConstraintInfo, 4> InputConstraintInfos;
for (unsigned i = NumOutputs, e = NumOutputs + NumInputs; i != e; i++) {
StringLiteral *Literal = Constraints[i];
assert(Literal->isAscii());
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());
}
ExprResult ER = CheckPlaceholderExpr(Exprs[i]);
if (ER.isInvalid())
return StmtError();
Exprs[i] = ER.get();
Expr *InputExpr = Exprs[i];
// Referring to parameters is not allowed in naked functions.
if (CheckNakedParmReference(InputExpr, *this))
return StmtError();
// Check that the input expression is compatible with memory constraint.
if (Info.allowsMemory() &&
checkExprMemoryConstraintCompat(*this, InputExpr, Info, true))
return StmtError();
// 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());
} else if (Info.requiresImmediateConstant() && !Info.allowsRegister()) {
if (!InputExpr->isValueDependent()) {
llvm::APSInt Result;
if (!InputExpr->EvaluateAsInt(Result, Context))
return StmtError(
Diag(InputExpr->getLocStart(), diag::err_asm_immediate_expected)
<< Info.getConstraintStr() << InputExpr->getSourceRange());
if (!Info.isValidAsmImmediate(Result))
return StmtError(Diag(InputExpr->getLocStart(),
diag::err_invalid_asm_value_for_constraint)
<< Result.toString(10) << Info.getConstraintStr()
<< InputExpr->getSourceRange());
}
} else {
ExprResult Result = DefaultFunctionArrayLvalueConversion(Exprs[i]);
if (Result.isInvalid())
return StmtError();
Exprs[i] = Result.get();
}
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());
}
}
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];
assert(Literal->isAscii());
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 ConstraintIdx = Piece.getOperandNo();
unsigned NumOperands = NS->getNumOutputs() + NS->getNumInputs();
// Look for the (ConstraintIdx - NumOperands + 1)th constraint with
// modifier '+'.
if (ConstraintIdx >= NumOperands) {
unsigned I = 0, E = NS->getNumOutputs();
for (unsigned Cnt = ConstraintIdx - NumOperands; I != E; ++I)
if (OutputConstraintInfos[I].isReadWrite() && Cnt-- == 0) {
ConstraintIdx = I;
break;
}
assert(I != E && "Invalid operand number should have been caught in "
" AnalyzeAsmString");
}
// 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);
std::string SuggestedModifier;
if (!Context.getTargetInfo().validateConstraintModifier(
Literal->getString(), Piece.getModifier(), Size,
SuggestedModifier)) {
Diag(Exprs[ConstraintIdx]->getLocStart(),
diag::warn_asm_mismatched_size_modifier);
if (!SuggestedModifier.empty()) {
auto B = Diag(Piece.getRange().getBegin(),
diag::note_asm_missing_constraint_modifier)
<< SuggestedModifier;
SuggestedModifier = "%" + SuggestedModifier + Piece.getString();
B.AddFixItHint(FixItHint::CreateReplacement(Piece.getRange(),
SuggestedModifier));
}
}
}
// Validate tied input operands for type mismatches.
unsigned NumAlternatives = ~0U;
for (unsigned i = 0, e = OutputConstraintInfos.size(); i != e; ++i) {
TargetInfo::ConstraintInfo &Info = OutputConstraintInfos[i];
StringRef ConstraintStr = Info.getConstraintStr();
unsigned AltCount = ConstraintStr.count(',') + 1;
if (NumAlternatives == ~0U)
NumAlternatives = AltCount;
else if (NumAlternatives != AltCount)
return StmtError(Diag(NS->getOutputExpr(i)->getLocStart(),
diag::err_asm_unexpected_constraint_alternatives)
<< NumAlternatives << AltCount);
}
SmallVector<size_t, 4> InputMatchedToOutput(OutputConstraintInfos.size(),
~0U);
for (unsigned i = 0, e = InputConstraintInfos.size(); i != e; ++i) {
TargetInfo::ConstraintInfo &Info = InputConstraintInfos[i];
StringRef ConstraintStr = Info.getConstraintStr();
unsigned AltCount = ConstraintStr.count(',') + 1;
if (NumAlternatives == ~0U)
NumAlternatives = AltCount;
else if (NumAlternatives != AltCount)
return StmtError(Diag(NS->getInputExpr(i)->getLocStart(),
diag::err_asm_unexpected_constraint_alternatives)
<< NumAlternatives << AltCount);
// 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];
// Make sure no more than one input constraint matches each output.
assert(TiedTo < InputMatchedToOutput.size() && "TiedTo value out of range");
if (InputMatchedToOutput[TiedTo] != ~0U) {
Diag(NS->getInputExpr(i)->getLocStart(),
diag::err_asm_input_duplicate_match)
<< TiedTo;
Diag(NS->getInputExpr(InputMatchedToOutput[TiedTo])->getLocStart(),
diag::note_asm_input_duplicate_first)
<< TiedTo;
return StmtError();
}
InputMatchedToOutput[TiedTo] = i;
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).get();
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 NS;
}
static void fillInlineAsmTypeInfo(const ASTContext &Context, QualType T,
llvm::InlineAsmIdentifierInfo &Info) {
// 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;
}
}
ExprResult Sema::LookupInlineAsmIdentifier(CXXScopeSpec &SS,
SourceLocation TemplateKWLoc,
UnqualifiedId &Id,
llvm::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=*/nullptr,
/*IsInlineAsmIdentifier=*/ true);
if (IsUnevaluatedContext)
PopExpressionEvaluationContext();
if (!Result.isUsable()) return Result;
Result = CheckPlaceholderExpr(Result.get());
if (!Result.isUsable()) return Result;
// Referring to parameters is not allowed in naked functions.
if (CheckNakedParmReference(Result.get(), *this))
return ExprError();
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();
}
fillInlineAsmTypeInfo(Context, T, Info);
// 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 = nullptr;
NamedDecl *FoundDecl = BaseResult.getFoundDecl();
if (VarDecl *VD = dyn_cast<VarDecl>(FoundDecl))
RT = VD->getType()->getAs<RecordType>();
else if (TypedefNameDecl *TD = dyn_cast<TypedefNameDecl>(FoundDecl)) {
MarkAnyDeclReferenced(TD->getLocation(), TD, /*OdrUse=*/false);
RT = TD->getUnderlyingType()->getAs<RecordType>();
} else if (TypeDecl *TD = dyn_cast<TypeDecl>(FoundDecl))
RT = TD->getTypeForDecl()->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;
}
ExprResult
Sema::LookupInlineAsmVarDeclField(Expr *E, StringRef Member, unsigned &Offset,
llvm::InlineAsmIdentifierInfo &Info,
SourceLocation AsmLoc) {
Info.clear();
const RecordType *RT = E->getType()->getAs<RecordType>();
// FIXME: Diagnose this as field access into a scalar type.
if (!RT)
return ExprResult();
LookupResult FieldResult(*this, &Context.Idents.get(Member), AsmLoc,
LookupMemberName);
if (!LookupQualifiedName(FieldResult, RT->getDecl()))
return ExprResult();
// Only normal and indirect field results will work.
ValueDecl *FD = dyn_cast<FieldDecl>(FieldResult.getFoundDecl());
if (!FD)
FD = dyn_cast<IndirectFieldDecl>(FieldResult.getFoundDecl());
if (!FD)
return ExprResult();
Offset = (unsigned)Context.toCharUnitsFromBits(Context.getFieldOffset(FD))
.getQuantity();
// Make an Expr to thread through OpDecl.
ExprResult Result = BuildMemberReferenceExpr(
E, E->getType(), AsmLoc, /*IsArrow=*/false, CXXScopeSpec(),
SourceLocation(), nullptr, FieldResult, nullptr, nullptr);
if (Result.isInvalid())
return Result;
Info.OpDecl = Result.get();
fillInlineAsmTypeInfo(Context, Result.get()->getType(), Info);
// Fields are "variables" as far as inline assembly is concerned.
Info.IsVarDecl = true;
return Result;
}
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);
getCurFunction()->setHasBranchProtectedScope();
MSAsmStmt *NS =
new (Context) MSAsmStmt(Context, AsmLoc, LBraceLoc, IsSimple,
/*IsVolatile*/ true, AsmToks, NumOutputs, NumInputs,
Constraints, Exprs, AsmString,
Clobbers, EndLoc);
return NS;
}
LabelDecl *Sema::GetOrCreateMSAsmLabel(StringRef ExternalLabelName,
SourceLocation Location,
bool AlwaysCreate) {
LabelDecl* Label = LookupOrCreateLabel(PP.getIdentifierInfo(ExternalLabelName),
Location);
if (Label->isMSAsmLabel()) {
// If we have previously created this label implicitly, mark it as used.
Label->markUsed(Context);
} else {
// Otherwise, insert it, but only resolve it if we have seen the label itself.
std::string InternalName;
llvm::raw_string_ostream OS(InternalName);
// Create an internal name for the label. The name should not be a valid mangled
// name, and should be unique. We use a dot to make the name an invalid mangled
// name.
OS << "__MSASMLABEL_." << MSAsmLabelNameCounter++ << "__" << ExternalLabelName;
Label->setMSAsmLabel(OS.str());
}
if (AlwaysCreate) {
// The label might have been created implicitly from a previously encountered
// goto statement. So, for both newly created and looked up labels, we mark
// them as resolved.
Label->setMSAsmLabelResolved();
}
// Adjust their location for being able to generate accurate diagnostics.
Label->setLocation(Location);
return Label;
}