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llvm-project/clang/lib/CodeGen/CGExprConstant.cpp

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//===--- CGExprConstant.cpp - Emit LLVM Code from Constant Expressions ----===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Constant Expr nodes as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "CGObjCRuntime.h"
#include "clang/AST/APValue.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/StmtVisitor.h"
#include "llvm/Constants.h"
#include "llvm/Function.h"
#include "llvm/GlobalVariable.h"
#include "llvm/Support/Compiler.h"
#include "llvm/Target/TargetData.h"
using namespace clang;
using namespace CodeGen;
namespace {
class VISIBILITY_HIDDEN ConstExprEmitter :
public StmtVisitor<ConstExprEmitter, llvm::Constant*> {
CodeGenModule &CGM;
CodeGenFunction *CGF;
public:
ConstExprEmitter(CodeGenModule &cgm, CodeGenFunction *cgf)
: CGM(cgm), CGF(cgf) {
}
//===--------------------------------------------------------------------===//
// Visitor Methods
//===--------------------------------------------------------------------===//
llvm::Constant *VisitStmt(Stmt *S) {
CGM.ErrorUnsupported(S, "constant expression");
QualType T = cast<Expr>(S)->getType();
return llvm::UndefValue::get(CGM.getTypes().ConvertType(T));
}
llvm::Constant *VisitParenExpr(ParenExpr *PE) {
return Visit(PE->getSubExpr());
}
llvm::Constant *VisitCompoundLiteralExpr(CompoundLiteralExpr *E) {
return Visit(E->getInitializer());
}
llvm::Constant *VisitCastExpr(CastExpr* E) {
// GCC cast to union extension
if (E->getType()->isUnionType()) {
const llvm::Type *Ty = ConvertType(E->getType());
return EmitUnion(CGM.EmitConstantExpr(E->getSubExpr(), CGF), Ty);
}
llvm::Constant *C = Visit(E->getSubExpr());
return EmitConversion(C, E->getSubExpr()->getType(), E->getType());
}
llvm::Constant *VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
return Visit(DAE->getExpr());
}
llvm::Constant *EmitArrayInitialization(InitListExpr *ILE) {
std::vector<llvm::Constant*> Elts;
const llvm::ArrayType *AType =
cast<llvm::ArrayType>(ConvertType(ILE->getType()));
unsigned NumInitElements = ILE->getNumInits();
// FIXME: Check for wide strings
if (NumInitElements > 0 && isa<StringLiteral>(ILE->getInit(0)) &&
ILE->getType()->getArrayElementTypeNoTypeQual()->isCharType())
return Visit(ILE->getInit(0));
const llvm::Type *ElemTy = AType->getElementType();
unsigned NumElements = AType->getNumElements();
// Initialising an array requires us to automatically
// initialise any elements that have not been initialised explicitly
unsigned NumInitableElts = std::min(NumInitElements, NumElements);
// Copy initializer elements.
unsigned i = 0;
bool RewriteType = false;
for (; i < NumInitableElts; ++i) {
llvm::Constant *C = CGM.EmitConstantExpr(ILE->getInit(i), CGF);
RewriteType |= (C->getType() != ElemTy);
Elts.push_back(C);
}
// Initialize remaining array elements.
for (; i < NumElements; ++i)
Elts.push_back(llvm::Constant::getNullValue(ElemTy));
if (RewriteType) {
// FIXME: Try to avoid packing the array
std::vector<const llvm::Type*> Types;
for (unsigned i = 0; i < Elts.size(); ++i)
Types.push_back(Elts[i]->getType());
const llvm::StructType *SType = llvm::StructType::get(Types, true);
return llvm::ConstantStruct::get(SType, Elts);
}
return llvm::ConstantArray::get(AType, Elts);
}
void InsertBitfieldIntoStruct(std::vector<llvm::Constant*>& Elts,
FieldDecl* Field, Expr* E) {
// Calculate the value to insert
llvm::Constant *C = CGM.EmitConstantExpr(E, CGF);
llvm::ConstantInt *CI = dyn_cast<llvm::ConstantInt>(C);
if (!CI) {
CGM.ErrorUnsupported(E, "bitfield initialization");
return;
}
llvm::APInt V = CI->getValue();
// Calculate information about the relevant field
const llvm::Type* Ty = CI->getType();
const llvm::TargetData &TD = CGM.getTypes().getTargetData();
unsigned size = TD.getTypePaddedSizeInBits(Ty);
unsigned fieldOffset = CGM.getTypes().getLLVMFieldNo(Field) * size;
CodeGenTypes::BitFieldInfo bitFieldInfo =
CGM.getTypes().getBitFieldInfo(Field);
fieldOffset += bitFieldInfo.Begin;
// Find where to start the insertion
// FIXME: This is O(n^2) in the number of bit-fields!
// FIXME: This won't work if the struct isn't completely packed!
unsigned offset = 0, i = 0;
while (offset < (fieldOffset & -8))
offset += TD.getTypePaddedSizeInBits(Elts[i++]->getType());
// Advance over 0 sized elements (must terminate in bounds since
// the bitfield must have a size).
while (TD.getTypePaddedSizeInBits(Elts[i]->getType()) == 0)
++i;
// Promote the size of V if necessary
// FIXME: This should never occur, but currently it can because
// initializer constants are cast to bool, and because clang is
// not enforcing bitfield width limits.
if (bitFieldInfo.Size > V.getBitWidth())
V.zext(bitFieldInfo.Size);
// Insert the bits into the struct
// FIXME: This algorthm is only correct on X86!
// FIXME: THis algorthm assumes bit-fields only have byte-size elements!
unsigned bitsToInsert = bitFieldInfo.Size;
unsigned curBits = std::min(8 - (fieldOffset & 7), bitsToInsert);
unsigned byte = V.getLoBits(curBits).getZExtValue() << (fieldOffset & 7);
do {
llvm::Constant* byteC = llvm::ConstantInt::get(llvm::Type::Int8Ty, byte);
Elts[i] = llvm::ConstantExpr::getOr(Elts[i], byteC);
++i;
V = V.lshr(curBits);
bitsToInsert -= curBits;
if (!bitsToInsert)
break;
curBits = bitsToInsert > 8 ? 8 : bitsToInsert;
byte = V.getLoBits(curBits).getZExtValue();
} while (true);
}
llvm::Constant *EmitStructInitialization(InitListExpr *ILE) {
const llvm::StructType *SType =
cast<llvm::StructType>(ConvertType(ILE->getType()));
RecordDecl *RD = ILE->getType()->getAsRecordType()->getDecl();
std::vector<llvm::Constant*> Elts;
// Initialize the whole structure to zero.
for (unsigned i = 0; i < SType->getNumElements(); ++i) {
const llvm::Type *FieldTy = SType->getElementType(i);
Elts.push_back(llvm::Constant::getNullValue(FieldTy));
}
// Copy initializer elements. Skip padding fields.
unsigned EltNo = 0; // Element no in ILE
int FieldNo = 0; // Field no in RecordDecl
bool RewriteType = false;
for (RecordDecl::field_iterator Field = RD->field_begin(),
FieldEnd = RD->field_end();
EltNo < ILE->getNumInits() && Field != FieldEnd; ++Field) {
FieldNo++;
if (!Field->getIdentifier())
continue;
if (Field->isBitField()) {
InsertBitfieldIntoStruct(Elts, *Field, ILE->getInit(EltNo));
} else {
unsigned FieldNo = CGM.getTypes().getLLVMFieldNo(*Field);
llvm::Constant *C = CGM.EmitConstantExpr(ILE->getInit(EltNo), CGF);
RewriteType |= (C->getType() != Elts[FieldNo]->getType());
Elts[FieldNo] = C;
}
EltNo++;
}
if (RewriteType) {
// FIXME: Make this work for non-packed structs
assert(SType->isPacked() && "Cannot recreate unpacked structs");
std::vector<const llvm::Type*> Types;
for (unsigned i = 0; i < Elts.size(); ++i)
Types.push_back(Elts[i]->getType());
SType = llvm::StructType::get(Types, true);
}
return llvm::ConstantStruct::get(SType, Elts);
}
llvm::Constant *EmitUnion(llvm::Constant *C, const llvm::Type *Ty) {
// Build a struct with the union sub-element as the first member,
// and padded to the appropriate size
std::vector<llvm::Constant*> Elts;
std::vector<const llvm::Type*> Types;
Elts.push_back(C);
Types.push_back(C->getType());
unsigned CurSize = CGM.getTargetData().getTypePaddedSize(C->getType());
unsigned TotalSize = CGM.getTargetData().getTypePaddedSize(Ty);
while (CurSize < TotalSize) {
Elts.push_back(llvm::Constant::getNullValue(llvm::Type::Int8Ty));
Types.push_back(llvm::Type::Int8Ty);
CurSize++;
}
// This always generates a packed struct
// FIXME: Try to generate an unpacked struct when we can
llvm::StructType* STy = llvm::StructType::get(Types, true);
return llvm::ConstantStruct::get(STy, Elts);
}
llvm::Constant *EmitUnionInitialization(InitListExpr *ILE) {
const llvm::Type *Ty = ConvertType(ILE->getType());
// If this is an empty initializer list, we value-initialize the
// union.
if (ILE->getNumInits() == 0)
return llvm::Constant::getNullValue(Ty);
FieldDecl* curField = ILE->getInitializedFieldInUnion();
if (!curField) {
// There's no field to initialize, so value-initialize the union.
#ifndef NDEBUG
// Make sure that it's really an empty and not a failure of
// semantic analysis.
RecordDecl *RD = ILE->getType()->getAsRecordType()->getDecl();
for (RecordDecl::field_iterator Field = RD->field_begin(),
FieldEnd = RD->field_end();
Field != FieldEnd; ++Field)
assert(Field->isUnnamedBitfield() && "Only unnamed bitfields allowed");
#endif
return llvm::Constant::getNullValue(Ty);
}
if (curField->isBitField()) {
// Create a dummy struct for bit-field insertion
unsigned NumElts = CGM.getTargetData().getTypePaddedSize(Ty) / 8;
llvm::Constant* NV = llvm::Constant::getNullValue(llvm::Type::Int8Ty);
std::vector<llvm::Constant*> Elts(NumElts, NV);
InsertBitfieldIntoStruct(Elts, curField, ILE->getInit(0));
const llvm::ArrayType *RetTy =
llvm::ArrayType::get(NV->getType(), NumElts);
return llvm::ConstantArray::get(RetTy, Elts);
}
return EmitUnion(CGM.EmitConstantExpr(ILE->getInit(0), CGF), Ty);
}
llvm::Constant *EmitVectorInitialization(InitListExpr *ILE) {
const llvm::VectorType *VType =
cast<llvm::VectorType>(ConvertType(ILE->getType()));
const llvm::Type *ElemTy = VType->getElementType();
std::vector<llvm::Constant*> Elts;
unsigned NumElements = VType->getNumElements();
unsigned NumInitElements = ILE->getNumInits();
unsigned NumInitableElts = std::min(NumInitElements, NumElements);
// Copy initializer elements.
unsigned i = 0;
for (; i < NumInitableElts; ++i) {
llvm::Constant *C = CGM.EmitConstantExpr(ILE->getInit(i), CGF);
Elts.push_back(C);
}
for (; i < NumElements; ++i)
Elts.push_back(llvm::Constant::getNullValue(ElemTy));
return llvm::ConstantVector::get(VType, Elts);
}
llvm::Constant *VisitImplicitValueInitExpr(ImplicitValueInitExpr* E) {
const llvm::Type* RetTy = CGM.getTypes().ConvertType(E->getType());
return llvm::Constant::getNullValue(RetTy);
}
llvm::Constant *VisitInitListExpr(InitListExpr *ILE) {
if (ILE->getType()->isScalarType()) {
// We have a scalar in braces. Just use the first element.
if (ILE->getNumInits() > 0)
return CGM.EmitConstantExpr(ILE->getInit(0), CGF);
const llvm::Type* RetTy = CGM.getTypes().ConvertType(ILE->getType());
return llvm::Constant::getNullValue(RetTy);
}
if (ILE->getType()->isArrayType())
return EmitArrayInitialization(ILE);
if (ILE->getType()->isStructureType())
return EmitStructInitialization(ILE);
if (ILE->getType()->isUnionType())
return EmitUnionInitialization(ILE);
if (ILE->getType()->isVectorType())
return EmitVectorInitialization(ILE);
assert(0 && "Unable to handle InitListExpr");
// Get rid of control reaches end of void function warning.
// Not reached.
return 0;
}
llvm::Constant *VisitImplicitCastExpr(ImplicitCastExpr *ICExpr) {
Expr* SExpr = ICExpr->getSubExpr();
QualType SType = SExpr->getType();
llvm::Constant *C; // the intermediate expression
QualType T; // the type of the intermediate expression
if (SType->isArrayType()) {
// Arrays decay to a pointer to the first element
// VLAs would require special handling, but they can't occur here
C = EmitLValue(SExpr);
llvm::Constant *Idx0 = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
llvm::Constant *Ops[] = {Idx0, Idx0};
C = llvm::ConstantExpr::getGetElementPtr(C, Ops, 2);
T = CGM.getContext().getArrayDecayedType(SType);
} else if (SType->isFunctionType()) {
// Function types decay to a pointer to the function
C = EmitLValue(SExpr);
T = CGM.getContext().getPointerType(SType);
} else {
C = Visit(SExpr);
T = SType;
}
// Perform the conversion; note that an implicit cast can both promote
// and convert an array/function
return EmitConversion(C, T, ICExpr->getType());
}
llvm::Constant *VisitStringLiteral(StringLiteral *E) {
assert(!E->getType()->isPointerType() && "Strings are always arrays");
// Otherwise this must be a string initializing an array in a static
// initializer. Don't emit it as the address of the string, emit the string
// data itself as an inline array.
return llvm::ConstantArray::get(CGM.GetStringForStringLiteral(E), false);
}
llvm::Constant *VisitUnaryExtension(const UnaryOperator *E) {
return Visit(E->getSubExpr());
}
// Utility methods
const llvm::Type *ConvertType(QualType T) {
return CGM.getTypes().ConvertType(T);
}
llvm::Constant *EmitConversionToBool(llvm::Constant *Src, QualType SrcType) {
assert(SrcType->isCanonical() && "EmitConversion strips typedefs");
if (SrcType->isRealFloatingType()) {
// Compare against 0.0 for fp scalars.
llvm::Constant *Zero = llvm::Constant::getNullValue(Src->getType());
return llvm::ConstantExpr::getFCmp(llvm::FCmpInst::FCMP_UNE, Src, Zero);
}
assert((SrcType->isIntegerType() || SrcType->isPointerType()) &&
"Unknown scalar type to convert");
// Compare against an integer or pointer null.
llvm::Constant *Zero = llvm::Constant::getNullValue(Src->getType());
return llvm::ConstantExpr::getICmp(llvm::ICmpInst::ICMP_NE, Src, Zero);
}
llvm::Constant *EmitConversion(llvm::Constant *Src, QualType SrcType,
QualType DstType) {
SrcType = CGM.getContext().getCanonicalType(SrcType);
DstType = CGM.getContext().getCanonicalType(DstType);
if (SrcType == DstType) return Src;
// Handle conversions to bool first, they are special: comparisons against 0.
if (DstType->isBooleanType())
return EmitConversionToBool(Src, SrcType);
const llvm::Type *DstTy = ConvertType(DstType);
// Ignore conversions like int -> uint.
if (Src->getType() == DstTy)
return Src;
// Handle pointer conversions next: pointers can only be converted to/from
// other pointers and integers.
if (isa<llvm::PointerType>(DstTy)) {
// The source value may be an integer, or a pointer.
if (isa<llvm::PointerType>(Src->getType()))
return llvm::ConstantExpr::getBitCast(Src, DstTy);
assert(SrcType->isIntegerType() &&"Not ptr->ptr or int->ptr conversion?");
return llvm::ConstantExpr::getIntToPtr(Src, DstTy);
}
if (isa<llvm::PointerType>(Src->getType())) {
// Must be an ptr to int cast.
assert(isa<llvm::IntegerType>(DstTy) && "not ptr->int?");
return llvm::ConstantExpr::getPtrToInt(Src, DstTy);
}
// A scalar source can be splatted to a vector of the same element type
if (isa<llvm::VectorType>(DstTy) && !isa<VectorType>(SrcType)) {
assert((cast<llvm::VectorType>(DstTy)->getElementType()
== Src->getType()) &&
"Vector element type must match scalar type to splat.");
unsigned NumElements = DstType->getAsVectorType()->getNumElements();
llvm::SmallVector<llvm::Constant*, 16> Elements;
for (unsigned i = 0; i < NumElements; i++)
Elements.push_back(Src);
return llvm::ConstantVector::get(&Elements[0], NumElements);
}
if (isa<llvm::VectorType>(Src->getType()) ||
isa<llvm::VectorType>(DstTy)) {
return llvm::ConstantExpr::getBitCast(Src, DstTy);
}
// Finally, we have the arithmetic types: real int/float.
if (isa<llvm::IntegerType>(Src->getType())) {
bool InputSigned = SrcType->isSignedIntegerType();
if (isa<llvm::IntegerType>(DstTy))
return llvm::ConstantExpr::getIntegerCast(Src, DstTy, InputSigned);
else if (InputSigned)
return llvm::ConstantExpr::getSIToFP(Src, DstTy);
else
return llvm::ConstantExpr::getUIToFP(Src, DstTy);
}
assert(Src->getType()->isFloatingPoint() && "Unknown real conversion");
if (isa<llvm::IntegerType>(DstTy)) {
if (DstType->isSignedIntegerType())
return llvm::ConstantExpr::getFPToSI(Src, DstTy);
else
return llvm::ConstantExpr::getFPToUI(Src, DstTy);
}
assert(DstTy->isFloatingPoint() && "Unknown real conversion");
if (DstTy->getTypeID() < Src->getType()->getTypeID())
return llvm::ConstantExpr::getFPTrunc(Src, DstTy);
else
return llvm::ConstantExpr::getFPExtend(Src, DstTy);
}
public:
llvm::Constant *EmitLValue(Expr *E) {
switch (E->getStmtClass()) {
default: break;
case Expr::ParenExprClass:
// Elide parenthesis
return EmitLValue(cast<ParenExpr>(E)->getSubExpr());
case Expr::CompoundLiteralExprClass: {
// Note that due to the nature of compound literals, this is guaranteed
// to be the only use of the variable, so we just generate it here.
CompoundLiteralExpr *CLE = cast<CompoundLiteralExpr>(E);
llvm::Constant* C = Visit(CLE->getInitializer());
C = new llvm::GlobalVariable(C->getType(),E->getType().isConstQualified(),
llvm::GlobalValue::InternalLinkage,
C, ".compoundliteral", &CGM.getModule());
return C;
}
case Expr::DeclRefExprClass:
case Expr::QualifiedDeclRefExprClass: {
NamedDecl *Decl = cast<DeclRefExpr>(E)->getDecl();
if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(Decl))
return CGM.GetAddrOfFunction(FD);
if (const VarDecl* VD = dyn_cast<VarDecl>(Decl)) {
if (VD->isFileVarDecl())
return CGM.GetAddrOfGlobalVar(VD);
else if (VD->isBlockVarDecl()) {
assert(CGF && "Can't access static local vars without CGF");
return CGF->GetAddrOfStaticLocalVar(VD);
}
}
break;
}
case Expr::MemberExprClass: {
MemberExpr* ME = cast<MemberExpr>(E);
llvm::Constant *Base;
if (ME->isArrow())
Base = Visit(ME->getBase());
else
Base = EmitLValue(ME->getBase());
FieldDecl *Field = dyn_cast<FieldDecl>(ME->getMemberDecl());
// FIXME: Handle other kinds of member expressions.
assert(Field && "No code generation for non-field member expressions");
unsigned FieldNumber = CGM.getTypes().getLLVMFieldNo(Field);
llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
llvm::Constant *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty,
FieldNumber);
llvm::Value *Ops[] = {Zero, Idx};
return llvm::ConstantExpr::getGetElementPtr(Base, Ops, 2);
}
case Expr::ArraySubscriptExprClass: {
ArraySubscriptExpr* ASExpr = cast<ArraySubscriptExpr>(E);
llvm::Constant *Base = Visit(ASExpr->getBase());
llvm::Constant *Index = Visit(ASExpr->getIdx());
assert(!ASExpr->getBase()->getType()->isVectorType() &&
"Taking the address of a vector component is illegal!");
return llvm::ConstantExpr::getGetElementPtr(Base, &Index, 1);
}
case Expr::StringLiteralClass:
return CGM.GetAddrOfConstantStringFromLiteral(cast<StringLiteral>(E));
case Expr::ObjCStringLiteralClass: {
ObjCStringLiteral* SL = cast<ObjCStringLiteral>(E);
std::string S(SL->getString()->getStrData(),
SL->getString()->getByteLength());
llvm::Constant *C = CGM.getObjCRuntime().GenerateConstantString(S);
return llvm::ConstantExpr::getBitCast(C, ConvertType(E->getType()));
}
case Expr::UnaryOperatorClass: {
UnaryOperator *Exp = cast<UnaryOperator>(E);
switch (Exp->getOpcode()) {
default: break;
case UnaryOperator::Extension:
// Extension is just a wrapper for expressions
return EmitLValue(Exp->getSubExpr());
case UnaryOperator::Real:
case UnaryOperator::Imag: {
// The address of __real or __imag is just a GEP off the address
// of the internal expression
llvm::Constant* C = EmitLValue(Exp->getSubExpr());
llvm::Constant *Zero = llvm::ConstantInt::get(llvm::Type::Int32Ty, 0);
llvm::Constant *Idx = llvm::ConstantInt::get(llvm::Type::Int32Ty,
Exp->getOpcode() == UnaryOperator::Imag);
llvm::Value *Ops[] = {Zero, Idx};
return llvm::ConstantExpr::getGetElementPtr(C, Ops, 2);
}
case UnaryOperator::Deref:
// The address of a deref is just the value of the expression
return Visit(Exp->getSubExpr());
}
break;
}
case Expr::PredefinedExprClass: {
// __func__/__FUNCTION__ -> "". __PRETTY_FUNCTION__ -> "top level".
std::string Str;
if (cast<PredefinedExpr>(E)->getIdentType() ==
PredefinedExpr::PrettyFunction)
Str = "top level";
return CGM.GetAddrOfConstantCString(Str, ".tmp");
}
case Expr::AddrLabelExprClass: {
assert(CGF && "Invalid address of label expression outside function.");
unsigned id = CGF->GetIDForAddrOfLabel(cast<AddrLabelExpr>(E)->getLabel());
llvm::Constant *C = llvm::ConstantInt::get(llvm::Type::Int32Ty, id);
return llvm::ConstantExpr::getIntToPtr(C, ConvertType(E->getType()));
}
case Expr::CallExprClass: {
CallExpr* CE = cast<CallExpr>(E);
if (CE->isBuiltinCall() != Builtin::BI__builtin___CFStringMakeConstantString)
break;
const Expr *Arg = CE->getArg(0)->IgnoreParenCasts();
const StringLiteral *Literal = cast<StringLiteral>(Arg);
std::string S(Literal->getStrData(), Literal->getByteLength());
return CGM.GetAddrOfConstantCFString(S);
}
}
CGM.ErrorUnsupported(E, "constant l-value expression");
llvm::Type *Ty = llvm::PointerType::getUnqual(ConvertType(E->getType()));
return llvm::UndefValue::get(Ty);
}
};
} // end anonymous namespace.
llvm::Constant *CodeGenModule::EmitConstantExpr(const Expr *E,
CodeGenFunction *CGF) {
QualType type = Context.getCanonicalType(E->getType());
Expr::EvalResult Result;
if (E->Evaluate(Result, Context)) {
assert(!Result.HasSideEffects &&
"Constant expr should not have any side effects!");
switch (Result.Val.getKind()) {
case APValue::Uninitialized:
assert(0 && "Constant expressions should be uninitialized.");
return llvm::UndefValue::get(getTypes().ConvertType(type));
case APValue::LValue: {
llvm::Constant *Offset =
llvm::ConstantInt::get(llvm::Type::Int64Ty,
Result.Val.getLValueOffset());
if (const Expr *LVBase = Result.Val.getLValueBase()) {
llvm::Constant *C =
ConstExprEmitter(*this, CGF).EmitLValue(const_cast<Expr*>(LVBase));
const llvm::Type *Type =
llvm::PointerType::getUnqual(llvm::Type::Int8Ty);
const llvm::Type *DestType = getTypes().ConvertTypeForMem(E->getType());
// FIXME: It's a little ugly that we need to cast to a pointer,
// apply the GEP and then cast back.
C = llvm::ConstantExpr::getBitCast(C, Type);
C = llvm::ConstantExpr::getGetElementPtr(C, &Offset, 1);
return llvm::ConstantExpr::getBitCast(C, DestType);
}
return llvm::ConstantExpr::getIntToPtr(Offset,
getTypes().ConvertType(type));
}
case APValue::Int: {
llvm::Constant *C = llvm::ConstantInt::get(Result.Val.getInt());
if (C->getType() == llvm::Type::Int1Ty) {
const llvm::Type *BoolTy = getTypes().ConvertTypeForMem(E->getType());
C = llvm::ConstantExpr::getZExt(C, BoolTy);
}
return C;
}
case APValue::ComplexInt: {
llvm::Constant *Complex[2];
Complex[0] = llvm::ConstantInt::get(Result.Val.getComplexIntReal());
Complex[1] = llvm::ConstantInt::get(Result.Val.getComplexIntImag());
return llvm::ConstantStruct::get(Complex, 2);
}
case APValue::Float:
return llvm::ConstantFP::get(Result.Val.getFloat());
case APValue::ComplexFloat: {
llvm::Constant *Complex[2];
Complex[0] = llvm::ConstantFP::get(Result.Val.getComplexFloatReal());
Complex[1] = llvm::ConstantFP::get(Result.Val.getComplexFloatImag());
return llvm::ConstantStruct::get(Complex, 2);
}
case APValue::Vector: {
llvm::SmallVector<llvm::Constant *, 4> Inits;
unsigned NumElts = Result.Val.getVectorLength();
for (unsigned i = 0; i != NumElts; ++i) {
APValue &Elt = Result.Val.getVectorElt(i);
if (Elt.isInt())
Inits.push_back(llvm::ConstantInt::get(Elt.getInt()));
else
Inits.push_back(llvm::ConstantFP::get(Elt.getFloat()));
}
return llvm::ConstantVector::get(&Inits[0], Inits.size());
}
}
}
llvm::Constant* C = ConstExprEmitter(*this, CGF).Visit(const_cast<Expr*>(E));
if (C->getType() == llvm::Type::Int1Ty) {
const llvm::Type *BoolTy = getTypes().ConvertTypeForMem(E->getType());
C = llvm::ConstantExpr::getZExt(C, BoolTy);
}
return C;
}
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