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

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//===--- MicrosoftCXXABI.cpp - Emit LLVM Code from ASTs for a Module ------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This provides C++ code generation targeting the Microsoft Visual C++ ABI.
// The class in this file generates structures that follow the Microsoft
// Visual C++ ABI, which is actually not very well documented at all outside
// of Microsoft.
//
//===----------------------------------------------------------------------===//
#include "CGCXXABI.h"
#include "CodeGenModule.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
using namespace clang;
using namespace CodeGen;
namespace {
class MicrosoftCXXABI : public CGCXXABI {
public:
MicrosoftCXXABI(CodeGenModule &CGM) : CGCXXABI(CGM) {}
StringRef GetPureVirtualCallName() { return "_purecall"; }
// No known support for deleted functions in MSVC yet, so this choice is
// arbitrary.
StringRef GetDeletedVirtualCallName() { return "_purecall"; }
llvm::Value *adjustToCompleteObject(CodeGenFunction &CGF,
llvm::Value *ptr,
QualType type);
void BuildConstructorSignature(const CXXConstructorDecl *Ctor,
CXXCtorType Type,
CanQualType &ResTy,
SmallVectorImpl<CanQualType> &ArgTys);
llvm::BasicBlock *EmitCtorCompleteObjectHandler(CodeGenFunction &CGF);
void BuildDestructorSignature(const CXXDestructorDecl *Ctor,
CXXDtorType Type,
CanQualType &ResTy,
SmallVectorImpl<CanQualType> &ArgTys);
void BuildInstanceFunctionParams(CodeGenFunction &CGF,
QualType &ResTy,
FunctionArgList &Params);
void EmitInstanceFunctionProlog(CodeGenFunction &CGF);
llvm::Value *EmitConstructorCall(CodeGenFunction &CGF,
const CXXConstructorDecl *D,
CXXCtorType Type, bool ForVirtualBase,
bool Delegating,
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd);
RValue EmitVirtualDestructorCall(CodeGenFunction &CGF,
const CXXDestructorDecl *Dtor,
CXXDtorType DtorType,
SourceLocation CallLoc,
ReturnValueSlot ReturnValue,
llvm::Value *This);
void EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
llvm::GlobalVariable *DeclPtr,
bool PerformInit);
// ==== Notes on array cookies =========
//
// MSVC seems to only use cookies when the class has a destructor; a
// two-argument usual array deallocation function isn't sufficient.
//
// For example, this code prints "100" and "1":
// struct A {
// char x;
// void *operator new[](size_t sz) {
// printf("%u\n", sz);
// return malloc(sz);
// }
// void operator delete[](void *p, size_t sz) {
// printf("%u\n", sz);
// free(p);
// }
// };
// int main() {
// A *p = new A[100];
// delete[] p;
// }
// Whereas it prints "104" and "104" if you give A a destructor.
bool requiresArrayCookie(const CXXDeleteExpr *expr, QualType elementType);
bool requiresArrayCookie(const CXXNewExpr *expr);
CharUnits getArrayCookieSizeImpl(QualType type);
llvm::Value *InitializeArrayCookie(CodeGenFunction &CGF,
llvm::Value *NewPtr,
llvm::Value *NumElements,
const CXXNewExpr *expr,
QualType ElementType);
llvm::Value *readArrayCookieImpl(CodeGenFunction &CGF,
llvm::Value *allocPtr,
CharUnits cookieSize);
static bool needThisReturn(GlobalDecl GD);
private:
llvm::Constant *getZeroInt() {
return llvm::ConstantInt::get(CGM.IntTy, 0);
}
llvm::Constant *getAllOnesInt() {
return llvm::Constant::getAllOnesValue(CGM.IntTy);
}
void
GetNullMemberPointerFields(const MemberPointerType *MPT,
llvm::SmallVectorImpl<llvm::Constant *> &fields);
llvm::Value *AdjustVirtualBase(CodeGenFunction &CGF, const CXXRecordDecl *RD,
llvm::Value *Base,
llvm::Value *VirtualBaseAdjustmentOffset,
llvm::Value *VBPtrOffset /* optional */);
public:
virtual llvm::Type *ConvertMemberPointerType(const MemberPointerType *MPT);
virtual bool isZeroInitializable(const MemberPointerType *MPT);
virtual llvm::Constant *EmitNullMemberPointer(const MemberPointerType *MPT);
virtual llvm::Constant *EmitMemberDataPointer(const MemberPointerType *MPT,
CharUnits offset);
virtual llvm::Value *EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
llvm::Value *MemPtr,
const MemberPointerType *MPT);
virtual llvm::Value *EmitMemberDataPointerAddress(CodeGenFunction &CGF,
llvm::Value *Base,
llvm::Value *MemPtr,
const MemberPointerType *MPT);
virtual llvm::Value *
EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
llvm::Value *&This,
llvm::Value *MemPtr,
const MemberPointerType *MPT);
};
}
llvm::Value *MicrosoftCXXABI::adjustToCompleteObject(CodeGenFunction &CGF,
llvm::Value *ptr,
QualType type) {
// FIXME: implement
return ptr;
}
bool MicrosoftCXXABI::needThisReturn(GlobalDecl GD) {
const CXXMethodDecl* MD = cast<CXXMethodDecl>(GD.getDecl());
return isa<CXXConstructorDecl>(MD);
}
void MicrosoftCXXABI::BuildConstructorSignature(const CXXConstructorDecl *Ctor,
CXXCtorType Type,
CanQualType &ResTy,
SmallVectorImpl<CanQualType> &ArgTys) {
// 'this' is already in place
// Ctor returns this ptr
ResTy = ArgTys[0];
const CXXRecordDecl *Class = Ctor->getParent();
if (Class->getNumVBases()) {
// Constructors of classes with virtual bases take an implicit parameter.
ArgTys.push_back(CGM.getContext().IntTy);
}
}
llvm::BasicBlock *MicrosoftCXXABI::EmitCtorCompleteObjectHandler(
CodeGenFunction &CGF) {
llvm::Value *IsMostDerivedClass = getStructorImplicitParamValue(CGF);
assert(IsMostDerivedClass &&
"ctor for a class with virtual bases must have an implicit parameter");
llvm::Value *IsCompleteObject
= CGF.Builder.CreateIsNotNull(IsMostDerivedClass, "is_complete_object");
llvm::BasicBlock *CallVbaseCtorsBB = CGF.createBasicBlock("ctor.init_vbases");
llvm::BasicBlock *SkipVbaseCtorsBB = CGF.createBasicBlock("ctor.skip_vbases");
CGF.Builder.CreateCondBr(IsCompleteObject,
CallVbaseCtorsBB, SkipVbaseCtorsBB);
CGF.EmitBlock(CallVbaseCtorsBB);
// FIXME: emit vbtables somewhere around here.
// CGF will put the base ctor calls in this basic block for us later.
return SkipVbaseCtorsBB;
}
void MicrosoftCXXABI::BuildDestructorSignature(const CXXDestructorDecl *Dtor,
CXXDtorType Type,
CanQualType &ResTy,
SmallVectorImpl<CanQualType> &ArgTys) {
// 'this' is already in place
// TODO: 'for base' flag
if (Type == Dtor_Deleting) {
// The scalar deleting destructor takes an implicit bool parameter.
ArgTys.push_back(CGM.getContext().BoolTy);
}
}
static bool IsDeletingDtor(GlobalDecl GD) {
const CXXMethodDecl* MD = cast<CXXMethodDecl>(GD.getDecl());
if (isa<CXXDestructorDecl>(MD)) {
return GD.getDtorType() == Dtor_Deleting;
}
return false;
}
void MicrosoftCXXABI::BuildInstanceFunctionParams(CodeGenFunction &CGF,
QualType &ResTy,
FunctionArgList &Params) {
BuildThisParam(CGF, Params);
if (needThisReturn(CGF.CurGD)) {
ResTy = Params[0]->getType();
}
ASTContext &Context = getContext();
const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
ImplicitParamDecl *IsMostDerived
= ImplicitParamDecl::Create(Context, 0,
CGF.CurGD.getDecl()->getLocation(),
&Context.Idents.get("is_most_derived"),
Context.IntTy);
Params.push_back(IsMostDerived);
getStructorImplicitParamDecl(CGF) = IsMostDerived;
} else if (IsDeletingDtor(CGF.CurGD)) {
ImplicitParamDecl *ShouldDelete
= ImplicitParamDecl::Create(Context, 0,
CGF.CurGD.getDecl()->getLocation(),
&Context.Idents.get("should_call_delete"),
Context.BoolTy);
Params.push_back(ShouldDelete);
getStructorImplicitParamDecl(CGF) = ShouldDelete;
}
}
void MicrosoftCXXABI::EmitInstanceFunctionProlog(CodeGenFunction &CGF) {
EmitThisParam(CGF);
if (needThisReturn(CGF.CurGD)) {
CGF.Builder.CreateStore(getThisValue(CGF), CGF.ReturnValue);
}
const CXXMethodDecl *MD = cast<CXXMethodDecl>(CGF.CurGD.getDecl());
if (isa<CXXConstructorDecl>(MD) && MD->getParent()->getNumVBases()) {
assert(getStructorImplicitParamDecl(CGF) &&
"no implicit parameter for a constructor with virtual bases?");
getStructorImplicitParamValue(CGF)
= CGF.Builder.CreateLoad(
CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
"is_most_derived");
}
if (IsDeletingDtor(CGF.CurGD)) {
assert(getStructorImplicitParamDecl(CGF) &&
"no implicit parameter for a deleting destructor?");
getStructorImplicitParamValue(CGF)
= CGF.Builder.CreateLoad(
CGF.GetAddrOfLocalVar(getStructorImplicitParamDecl(CGF)),
"should_call_delete");
}
}
llvm::Value *MicrosoftCXXABI::EmitConstructorCall(CodeGenFunction &CGF,
const CXXConstructorDecl *D,
CXXCtorType Type, bool ForVirtualBase,
bool Delegating,
llvm::Value *This,
CallExpr::const_arg_iterator ArgBeg,
CallExpr::const_arg_iterator ArgEnd) {
assert(Type == Ctor_Complete || Type == Ctor_Base);
llvm::Value *Callee = CGM.GetAddrOfCXXConstructor(D, Ctor_Complete);
llvm::Value *ImplicitParam = 0;
QualType ImplicitParamTy;
if (D->getParent()->getNumVBases()) {
ImplicitParam = llvm::ConstantInt::get(CGM.Int32Ty, Type == Ctor_Complete);
ImplicitParamTy = getContext().IntTy;
}
// FIXME: Provide a source location here.
CGF.EmitCXXMemberCall(D, SourceLocation(), Callee, ReturnValueSlot(), This,
ImplicitParam, ImplicitParamTy,
ArgBeg, ArgEnd);
return Callee;
}
RValue MicrosoftCXXABI::EmitVirtualDestructorCall(CodeGenFunction &CGF,
const CXXDestructorDecl *Dtor,
CXXDtorType DtorType,
SourceLocation CallLoc,
ReturnValueSlot ReturnValue,
llvm::Value *This) {
assert(DtorType == Dtor_Deleting || DtorType == Dtor_Complete);
// We have only one destructor in the vftable but can get both behaviors
// by passing an implicit bool parameter.
const CGFunctionInfo *FInfo
= &CGM.getTypes().arrangeCXXDestructor(Dtor, Dtor_Deleting);
llvm::Type *Ty = CGF.CGM.getTypes().GetFunctionType(*FInfo);
llvm::Value *Callee = CGF.BuildVirtualCall(Dtor, Dtor_Deleting, This, Ty);
ASTContext &Context = CGF.getContext();
llvm::Value *ImplicitParam
= llvm::ConstantInt::get(llvm::IntegerType::getInt1Ty(CGF.getLLVMContext()),
DtorType == Dtor_Deleting);
return CGF.EmitCXXMemberCall(Dtor, CallLoc, Callee, ReturnValue, This,
ImplicitParam, Context.BoolTy, 0, 0);
}
bool MicrosoftCXXABI::requiresArrayCookie(const CXXDeleteExpr *expr,
QualType elementType) {
// Microsoft seems to completely ignore the possibility of a
// two-argument usual deallocation function.
return elementType.isDestructedType();
}
bool MicrosoftCXXABI::requiresArrayCookie(const CXXNewExpr *expr) {
// Microsoft seems to completely ignore the possibility of a
// two-argument usual deallocation function.
return expr->getAllocatedType().isDestructedType();
}
CharUnits MicrosoftCXXABI::getArrayCookieSizeImpl(QualType type) {
// The array cookie is always a size_t; we then pad that out to the
// alignment of the element type.
ASTContext &Ctx = getContext();
return std::max(Ctx.getTypeSizeInChars(Ctx.getSizeType()),
Ctx.getTypeAlignInChars(type));
}
llvm::Value *MicrosoftCXXABI::readArrayCookieImpl(CodeGenFunction &CGF,
llvm::Value *allocPtr,
CharUnits cookieSize) {
unsigned AS = allocPtr->getType()->getPointerAddressSpace();
llvm::Value *numElementsPtr =
CGF.Builder.CreateBitCast(allocPtr, CGF.SizeTy->getPointerTo(AS));
return CGF.Builder.CreateLoad(numElementsPtr);
}
llvm::Value* MicrosoftCXXABI::InitializeArrayCookie(CodeGenFunction &CGF,
llvm::Value *newPtr,
llvm::Value *numElements,
const CXXNewExpr *expr,
QualType elementType) {
assert(requiresArrayCookie(expr));
// The size of the cookie.
CharUnits cookieSize = getArrayCookieSizeImpl(elementType);
// Compute an offset to the cookie.
llvm::Value *cookiePtr = newPtr;
// Write the number of elements into the appropriate slot.
unsigned AS = newPtr->getType()->getPointerAddressSpace();
llvm::Value *numElementsPtr
= CGF.Builder.CreateBitCast(cookiePtr, CGF.SizeTy->getPointerTo(AS));
CGF.Builder.CreateStore(numElements, numElementsPtr);
// Finally, compute a pointer to the actual data buffer by skipping
// over the cookie completely.
return CGF.Builder.CreateConstInBoundsGEP1_64(newPtr,
cookieSize.getQuantity());
}
void MicrosoftCXXABI::EmitGuardedInit(CodeGenFunction &CGF, const VarDecl &D,
llvm::GlobalVariable *DeclPtr,
bool PerformInit) {
// FIXME: this code was only tested for global initialization.
// Not sure whether we want thread-safe static local variables as VS
// doesn't make them thread-safe.
if (D.getTLSKind())
CGM.ErrorUnsupported(&D, "dynamic TLS initialization");
// Emit the initializer and add a global destructor if appropriate.
CGF.EmitCXXGlobalVarDeclInit(D, DeclPtr, PerformInit);
}
// Member pointer helpers.
static bool hasVBPtrOffsetField(MSInheritanceModel Inheritance) {
return Inheritance == MSIM_Unspecified;
}
// Only member pointers to functions need a this adjustment, since it can be
// combined with the field offset for data pointers.
static bool hasNonVirtualBaseAdjustmentField(const MemberPointerType *MPT,
MSInheritanceModel Inheritance) {
return (MPT->isMemberFunctionPointer() &&
Inheritance >= MSIM_Multiple);
}
static bool hasVirtualBaseAdjustmentField(MSInheritanceModel Inheritance) {
return Inheritance >= MSIM_Virtual;
}
// Use zero for the field offset of a null data member pointer if we can
// guarantee that zero is not a valid field offset, or if the member pointer has
// multiple fields. Polymorphic classes have a vfptr at offset zero, so we can
// use zero for null. If there are multiple fields, we can use zero even if it
// is a valid field offset because null-ness testing will check the other
// fields.
static bool nullFieldOffsetIsZero(MSInheritanceModel Inheritance) {
return Inheritance != MSIM_Multiple && Inheritance != MSIM_Single;
}
bool MicrosoftCXXABI::isZeroInitializable(const MemberPointerType *MPT) {
// Null-ness for function memptrs only depends on the first field, which is
// the function pointer. The rest don't matter, so we can zero initialize.
if (MPT->isMemberFunctionPointer())
return true;
// The virtual base adjustment field is always -1 for null, so if we have one
// we can't zero initialize. The field offset is sometimes also -1 if 0 is a
// valid field offset.
const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
return (!hasVirtualBaseAdjustmentField(Inheritance) &&
nullFieldOffsetIsZero(Inheritance));
}
llvm::Type *
MicrosoftCXXABI::ConvertMemberPointerType(const MemberPointerType *MPT) {
const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
llvm::SmallVector<llvm::Type *, 4> fields;
if (MPT->isMemberFunctionPointer())
fields.push_back(CGM.VoidPtrTy); // FunctionPointerOrVirtualThunk
else
fields.push_back(CGM.IntTy); // FieldOffset
if (hasVBPtrOffsetField(Inheritance))
fields.push_back(CGM.IntTy);
if (hasNonVirtualBaseAdjustmentField(MPT, Inheritance))
fields.push_back(CGM.IntTy);
if (hasVirtualBaseAdjustmentField(Inheritance))
fields.push_back(CGM.IntTy); // VirtualBaseAdjustmentOffset
if (fields.size() == 1)
return fields[0];
return llvm::StructType::get(CGM.getLLVMContext(), fields);
}
void MicrosoftCXXABI::
GetNullMemberPointerFields(const MemberPointerType *MPT,
llvm::SmallVectorImpl<llvm::Constant *> &fields) {
assert(fields.empty());
const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
if (MPT->isMemberFunctionPointer()) {
// FunctionPointerOrVirtualThunk
fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
} else {
if (nullFieldOffsetIsZero(Inheritance))
fields.push_back(getZeroInt()); // FieldOffset
else
fields.push_back(getAllOnesInt()); // FieldOffset
}
if (hasVBPtrOffsetField(Inheritance))
fields.push_back(getZeroInt());
if (hasNonVirtualBaseAdjustmentField(MPT, Inheritance))
fields.push_back(getZeroInt());
if (hasVirtualBaseAdjustmentField(Inheritance))
fields.push_back(getAllOnesInt());
}
llvm::Constant *
MicrosoftCXXABI::EmitNullMemberPointer(const MemberPointerType *MPT) {
llvm::SmallVector<llvm::Constant *, 4> fields;
GetNullMemberPointerFields(MPT, fields);
if (fields.size() == 1)
return fields[0];
llvm::Constant *Res = llvm::ConstantStruct::getAnon(fields);
assert(Res->getType() == ConvertMemberPointerType(MPT));
return Res;
}
llvm::Constant *
MicrosoftCXXABI::EmitMemberDataPointer(const MemberPointerType *MPT,
CharUnits offset) {
const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
llvm::SmallVector<llvm::Constant *, 4> fields;
fields.push_back(llvm::ConstantInt::get(CGM.IntTy, offset.getQuantity()));
if (hasVBPtrOffsetField(Inheritance)) {
int64_t VBPtrOffset =
getContext().getASTRecordLayout(RD).getVBPtrOffset().getQuantity();
fields.push_back(llvm::ConstantInt::get(CGM.IntTy, VBPtrOffset));
}
assert(!hasNonVirtualBaseAdjustmentField(MPT, Inheritance));
// The virtual base field starts out zero. It is adjusted by conversions to
// member pointer types of a more derived class. See http://llvm.org/PR15713
if (hasVirtualBaseAdjustmentField(Inheritance))
fields.push_back(getZeroInt());
if (fields.size() == 1)
return fields[0];
return llvm::ConstantStruct::getAnon(fields);
}
llvm::Value *
MicrosoftCXXABI::EmitMemberPointerIsNotNull(CodeGenFunction &CGF,
llvm::Value *MemPtr,
const MemberPointerType *MPT) {
CGBuilderTy &Builder = CGF.Builder;
llvm::SmallVector<llvm::Constant *, 4> fields;
// We only need one field for member functions.
if (MPT->isMemberFunctionPointer())
fields.push_back(llvm::Constant::getNullValue(CGM.VoidPtrTy));
else
GetNullMemberPointerFields(MPT, fields);
assert(!fields.empty());
llvm::Value *FirstField = MemPtr;
if (MemPtr->getType()->isStructTy())
FirstField = Builder.CreateExtractValue(MemPtr, 0);
llvm::Value *Res = Builder.CreateICmpNE(FirstField, fields[0], "memptr.cmp0");
// For function member pointers, we only need to test the function pointer
// field. The other fields if any can be garbage.
if (MPT->isMemberFunctionPointer())
return Res;
// Otherwise, emit a series of compares and combine the results.
for (int I = 1, E = fields.size(); I < E; ++I) {
llvm::Value *Field = Builder.CreateExtractValue(MemPtr, I);
llvm::Value *Next = Builder.CreateICmpNE(Field, fields[I], "memptr.cmp");
Res = Builder.CreateAnd(Res, Next, "memptr.tobool");
}
return Res;
}
// Returns an adjusted base cast to i8*, since we do more address arithmetic on
// it.
llvm::Value *
MicrosoftCXXABI::AdjustVirtualBase(CodeGenFunction &CGF,
const CXXRecordDecl *RD, llvm::Value *Base,
llvm::Value *VirtualBaseAdjustmentOffset,
llvm::Value *VBPtrOffset) {
CGBuilderTy &Builder = CGF.Builder;
Base = Builder.CreateBitCast(Base, CGM.Int8PtrTy);
llvm::BasicBlock *OriginalBB = 0;
llvm::BasicBlock *SkipAdjustBB = 0;
llvm::BasicBlock *VBaseAdjustBB = 0;
// In the unspecified inheritance model, there might not be a vbtable at all,
// in which case we need to skip the virtual base lookup. If there is a
// vbtable, the first entry is a no-op entry that gives back the original
// base, so look for a virtual base adjustment offset of zero.
if (VBPtrOffset) {
OriginalBB = Builder.GetInsertBlock();
VBaseAdjustBB = CGF.createBasicBlock("memptr.vadjust");
SkipAdjustBB = CGF.createBasicBlock("memptr.skip_vadjust");
llvm::Value *IsVirtual =
Builder.CreateICmpNE(VirtualBaseAdjustmentOffset, getZeroInt(),
"memptr.is_vbase");
Builder.CreateCondBr(IsVirtual, VBaseAdjustBB, SkipAdjustBB);
CGF.EmitBlock(VBaseAdjustBB);
}
// If we weren't given a dynamic vbptr offset, RD should be complete and we'll
// know the vbptr offset.
if (!VBPtrOffset) {
CharUnits offs = getContext().getASTRecordLayout(RD).getVBPtrOffset();
VBPtrOffset = llvm::ConstantInt::get(CGM.IntTy, offs.getQuantity());
}
// Load the vbtable pointer from the vbtable offset in the instance.
llvm::Value *VBPtr =
Builder.CreateInBoundsGEP(Base, VBPtrOffset, "memptr.vbptr");
llvm::Value *VBTable =
Builder.CreateBitCast(VBPtr, CGM.Int8PtrTy->getPointerTo(0));
VBTable = Builder.CreateLoad(VBTable, "memptr.vbtable");
// Load an i32 offset from the vb-table.
llvm::Value *VBaseOffs =
Builder.CreateInBoundsGEP(VBTable, VirtualBaseAdjustmentOffset);
VBaseOffs = Builder.CreateBitCast(VBaseOffs, CGM.Int32Ty->getPointerTo(0));
VBaseOffs = Builder.CreateLoad(VBaseOffs, "memptr.vbase_offs");
// Add it to VBPtr. GEP will sign extend the i32 value for us.
llvm::Value *AdjustedBase = Builder.CreateInBoundsGEP(VBPtr, VBaseOffs);
// Merge control flow with the case where we didn't have to adjust.
if (VBaseAdjustBB) {
Builder.CreateBr(SkipAdjustBB);
CGF.EmitBlock(SkipAdjustBB);
llvm::PHINode *Phi = Builder.CreatePHI(CGM.Int8PtrTy, 2, "memptr.base");
Phi->addIncoming(Base, OriginalBB);
Phi->addIncoming(AdjustedBase, VBaseAdjustBB);
return Phi;
}
return AdjustedBase;
}
llvm::Value *
MicrosoftCXXABI::EmitMemberDataPointerAddress(CodeGenFunction &CGF,
llvm::Value *Base,
llvm::Value *MemPtr,
const MemberPointerType *MPT) {
assert(MPT->isMemberDataPointer());
unsigned AS = Base->getType()->getPointerAddressSpace();
llvm::Type *PType =
CGF.ConvertTypeForMem(MPT->getPointeeType())->getPointerTo(AS);
CGBuilderTy &Builder = CGF.Builder;
const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
// Extract the fields we need, regardless of model. We'll apply them if we
// have them.
llvm::Value *FieldOffset = MemPtr;
llvm::Value *VirtualBaseAdjustmentOffset = 0;
llvm::Value *VBPtrOffset = 0;
if (MemPtr->getType()->isStructTy()) {
// We need to extract values.
unsigned I = 0;
FieldOffset = Builder.CreateExtractValue(MemPtr, I++);
if (hasVBPtrOffsetField(Inheritance))
VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
if (hasVirtualBaseAdjustmentField(Inheritance))
VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
}
if (VirtualBaseAdjustmentOffset) {
Base = AdjustVirtualBase(CGF, RD, Base, VirtualBaseAdjustmentOffset,
VBPtrOffset);
}
llvm::Value *Addr =
Builder.CreateInBoundsGEP(Base, FieldOffset, "memptr.offset");
// Cast the address to the appropriate pointer type, adopting the address
// space of the base pointer.
return Builder.CreateBitCast(Addr, PType);
}
llvm::Value *
MicrosoftCXXABI::EmitLoadOfMemberFunctionPointer(CodeGenFunction &CGF,
llvm::Value *&This,
llvm::Value *MemPtr,
const MemberPointerType *MPT) {
assert(MPT->isMemberFunctionPointer());
const FunctionProtoType *FPT =
MPT->getPointeeType()->castAs<FunctionProtoType>();
const CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
llvm::FunctionType *FTy =
CGM.getTypes().GetFunctionType(
CGM.getTypes().arrangeCXXMethodType(RD, FPT));
CGBuilderTy &Builder = CGF.Builder;
MSInheritanceModel Inheritance = RD->getMSInheritanceModel();
// Extract the fields we need, regardless of model. We'll apply them if we
// have them.
llvm::Value *FunctionPointer = MemPtr;
llvm::Value *NonVirtualBaseAdjustment = NULL;
llvm::Value *VirtualBaseAdjustmentOffset = NULL;
llvm::Value *VBPtrOffset = NULL;
if (MemPtr->getType()->isStructTy()) {
// We need to extract values.
unsigned I = 0;
FunctionPointer = Builder.CreateExtractValue(MemPtr, I++);
if (hasVBPtrOffsetField(Inheritance))
VBPtrOffset = Builder.CreateExtractValue(MemPtr, I++);
if (hasNonVirtualBaseAdjustmentField(MPT, Inheritance))
NonVirtualBaseAdjustment = Builder.CreateExtractValue(MemPtr, I++);
if (hasVirtualBaseAdjustmentField(Inheritance))
VirtualBaseAdjustmentOffset = Builder.CreateExtractValue(MemPtr, I++);
}
if (VirtualBaseAdjustmentOffset) {
This = AdjustVirtualBase(CGF, RD, This, VirtualBaseAdjustmentOffset,
VBPtrOffset);
}
if (NonVirtualBaseAdjustment) {
// Apply the adjustment and cast back to the original struct type.
llvm::Value *Ptr = Builder.CreateBitCast(This, Builder.getInt8PtrTy());
Ptr = Builder.CreateInBoundsGEP(Ptr, NonVirtualBaseAdjustment);
This = Builder.CreateBitCast(Ptr, This->getType(), "this.adjusted");
}
return Builder.CreateBitCast(FunctionPointer, FTy->getPointerTo());
}
CGCXXABI *clang::CodeGen::CreateMicrosoftCXXABI(CodeGenModule &CGM) {
return new MicrosoftCXXABI(CGM);
}
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