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

632 lines
24 KiB
C++

//===--- CGDecl.cpp - Emit LLVM Code for declarations ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code dealing with C++ code generation.
//
//===----------------------------------------------------------------------===//
// We might split this into multiple files if it gets too unwieldy
#include "CodeGenFunction.h"
#include "CodeGenModule.h"
#include "Mangle.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/DeclObjC.h"
#include "clang/AST/StmtCXX.h"
#include "clang/CodeGen/CodeGenOptions.h"
#include "llvm/ADT/StringExtras.h"
using namespace clang;
using namespace CodeGen;
/// Determines whether the given function has a trivial body that does
/// not require any specific codegen.
static bool HasTrivialBody(const FunctionDecl *FD) {
Stmt *S = FD->getBody();
if (!S)
return true;
if (isa<CompoundStmt>(S) && cast<CompoundStmt>(S)->body_empty())
return true;
return false;
}
/// Try to emit a base destructor as an alias to its primary
/// base-class destructor.
bool CodeGenModule::TryEmitBaseDestructorAsAlias(const CXXDestructorDecl *D) {
if (!getCodeGenOpts().CXXCtorDtorAliases)
return true;
// If the destructor doesn't have a trivial body, we have to emit it
// separately.
if (!HasTrivialBody(D))
return true;
const CXXRecordDecl *Class = D->getParent();
// If we need to manipulate a VTT parameter, give up.
if (Class->getNumVBases()) {
// Extra Credit: passing extra parameters is perfectly safe
// in many calling conventions, so only bail out if the ctor's
// calling convention is nonstandard.
return true;
}
// If any fields have a non-trivial destructor, we have to emit it
// separately.
for (CXXRecordDecl::field_iterator I = Class->field_begin(),
E = Class->field_end(); I != E; ++I)
if (const RecordType *RT = (*I)->getType()->getAs<RecordType>())
if (!cast<CXXRecordDecl>(RT->getDecl())->hasTrivialDestructor())
return true;
// Try to find a unique base class with a non-trivial destructor.
const CXXRecordDecl *UniqueBase = 0;
for (CXXRecordDecl::base_class_const_iterator I = Class->bases_begin(),
E = Class->bases_end(); I != E; ++I) {
// We're in the base destructor, so skip virtual bases.
if (I->isVirtual()) continue;
// Skip base classes with trivial destructors.
const CXXRecordDecl *Base
= cast<CXXRecordDecl>(I->getType()->getAs<RecordType>()->getDecl());
if (Base->hasTrivialDestructor()) continue;
// If we've already found a base class with a non-trivial
// destructor, give up.
if (UniqueBase) return true;
UniqueBase = Base;
}
// If we didn't find any bases with a non-trivial destructor, then
// the base destructor is actually effectively trivial, which can
// happen if it was needlessly user-defined or if there are virtual
// bases with non-trivial destructors.
if (!UniqueBase)
return true;
// If the base is at a non-zero offset, give up.
const ASTRecordLayout &ClassLayout = Context.getASTRecordLayout(Class);
if (ClassLayout.getBaseClassOffset(UniqueBase) != 0)
return true;
const CXXDestructorDecl *BaseD = UniqueBase->getDestructor(getContext());
return TryEmitDefinitionAsAlias(GlobalDecl(D, Dtor_Base),
GlobalDecl(BaseD, Dtor_Base));
}
/// Try to emit a definition as a global alias for another definition.
bool CodeGenModule::TryEmitDefinitionAsAlias(GlobalDecl AliasDecl,
GlobalDecl TargetDecl) {
if (!getCodeGenOpts().CXXCtorDtorAliases)
return true;
// The alias will use the linkage of the referrent. If we can't
// support aliases with that linkage, fail.
llvm::GlobalValue::LinkageTypes Linkage
= getFunctionLinkage(cast<FunctionDecl>(AliasDecl.getDecl()));
switch (Linkage) {
// We can definitely emit aliases to definitions with external linkage.
case llvm::GlobalValue::ExternalLinkage:
case llvm::GlobalValue::ExternalWeakLinkage:
break;
// Same with local linkage.
case llvm::GlobalValue::InternalLinkage:
case llvm::GlobalValue::PrivateLinkage:
case llvm::GlobalValue::LinkerPrivateLinkage:
break;
// We should try to support linkonce linkages.
case llvm::GlobalValue::LinkOnceAnyLinkage:
case llvm::GlobalValue::LinkOnceODRLinkage:
return true;
// Other linkages will probably never be supported.
default:
return true;
}
// Derive the type for the alias.
const llvm::PointerType *AliasType
= getTypes().GetFunctionType(AliasDecl)->getPointerTo();
// Find the referrent. Some aliases might require a bitcast, in
// which case the caller is responsible for ensuring the soundness
// of these semantics.
llvm::GlobalValue *Ref = cast<llvm::GlobalValue>(GetAddrOfGlobal(TargetDecl));
llvm::Constant *Aliasee = Ref;
if (Ref->getType() != AliasType)
Aliasee = llvm::ConstantExpr::getBitCast(Ref, AliasType);
// Create the alias with no name.
llvm::GlobalAlias *Alias =
new llvm::GlobalAlias(AliasType, Linkage, "", Aliasee, &getModule());
// Switch any previous uses to the alias.
const char *MangledName = getMangledName(AliasDecl);
llvm::GlobalValue *&Entry = GlobalDeclMap[MangledName];
if (Entry) {
assert(Entry->isDeclaration() && "definition already exists for alias");
assert(Entry->getType() == AliasType &&
"declaration exists with different type");
Entry->replaceAllUsesWith(Alias);
Entry->eraseFromParent();
}
Entry = Alias;
// Finally, set up the alias with its proper name and attributes.
Alias->setName(MangledName);
SetCommonAttributes(AliasDecl.getDecl(), Alias);
return false;
}
void CodeGenModule::EmitCXXConstructors(const CXXConstructorDecl *D) {
// The constructor used for constructing this as a complete class;
// constucts the virtual bases, then calls the base constructor.
EmitGlobal(GlobalDecl(D, Ctor_Complete));
// The constructor used for constructing this as a base class;
// ignores virtual bases.
EmitGlobal(GlobalDecl(D, Ctor_Base));
}
void CodeGenModule::EmitCXXConstructor(const CXXConstructorDecl *D,
CXXCtorType Type) {
// The complete constructor is equivalent to the base constructor
// for classes with no virtual bases. Try to emit it as an alias.
if (Type == Ctor_Complete &&
!D->getParent()->getNumVBases() &&
!TryEmitDefinitionAsAlias(GlobalDecl(D, Ctor_Complete),
GlobalDecl(D, Ctor_Base)))
return;
llvm::Function *Fn = cast<llvm::Function>(GetAddrOfCXXConstructor(D, Type));
CodeGenFunction(*this).GenerateCode(GlobalDecl(D, Type), Fn);
SetFunctionDefinitionAttributes(D, Fn);
SetLLVMFunctionAttributesForDefinition(D, Fn);
}
llvm::GlobalValue *
CodeGenModule::GetAddrOfCXXConstructor(const CXXConstructorDecl *D,
CXXCtorType Type) {
const char *Name = getMangledCXXCtorName(D, Type);
if (llvm::GlobalValue *V = GlobalDeclMap[Name])
return V;
const FunctionProtoType *FPT = D->getType()->getAs<FunctionProtoType>();
const llvm::FunctionType *FTy =
getTypes().GetFunctionType(getTypes().getFunctionInfo(D, Type),
FPT->isVariadic());
return cast<llvm::Function>(
GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type)));
}
const char *CodeGenModule::getMangledCXXCtorName(const CXXConstructorDecl *D,
CXXCtorType Type) {
llvm::SmallString<256> Name;
getMangleContext().mangleCXXCtor(D, Type, Name);
Name += '\0';
return UniqueMangledName(Name.begin(), Name.end());
}
void CodeGenModule::EmitCXXDestructors(const CXXDestructorDecl *D) {
// The destructor in a virtual table is always a 'deleting'
// destructor, which calls the complete destructor and then uses the
// appropriate operator delete.
if (D->isVirtual())
EmitGlobal(GlobalDecl(D, Dtor_Deleting));
// The destructor used for destructing this as a most-derived class;
// call the base destructor and then destructs any virtual bases.
EmitGlobal(GlobalDecl(D, Dtor_Complete));
// The destructor used for destructing this as a base class; ignores
// virtual bases.
EmitGlobal(GlobalDecl(D, Dtor_Base));
}
void CodeGenModule::EmitCXXDestructor(const CXXDestructorDecl *D,
CXXDtorType Type) {
// The complete destructor is equivalent to the base destructor for
// classes with no virtual bases, so try to emit it as an alias.
if (Type == Dtor_Complete &&
!D->getParent()->getNumVBases() &&
!TryEmitDefinitionAsAlias(GlobalDecl(D, Dtor_Complete),
GlobalDecl(D, Dtor_Base)))
return;
// The base destructor is equivalent to the base destructor of its
// base class if there is exactly one non-virtual base class with a
// non-trivial destructor, there are no fields with a non-trivial
// destructor, and the body of the destructor is trivial.
if (Type == Dtor_Base && !TryEmitBaseDestructorAsAlias(D))
return;
llvm::Function *Fn = cast<llvm::Function>(GetAddrOfCXXDestructor(D, Type));
CodeGenFunction(*this).GenerateCode(GlobalDecl(D, Type), Fn);
SetFunctionDefinitionAttributes(D, Fn);
SetLLVMFunctionAttributesForDefinition(D, Fn);
}
llvm::GlobalValue *
CodeGenModule::GetAddrOfCXXDestructor(const CXXDestructorDecl *D,
CXXDtorType Type) {
const char *Name = getMangledCXXDtorName(D, Type);
if (llvm::GlobalValue *V = GlobalDeclMap[Name])
return V;
const llvm::FunctionType *FTy =
getTypes().GetFunctionType(getTypes().getFunctionInfo(D, Type), false);
return cast<llvm::Function>(
GetOrCreateLLVMFunction(Name, FTy, GlobalDecl(D, Type)));
}
const char *CodeGenModule::getMangledCXXDtorName(const CXXDestructorDecl *D,
CXXDtorType Type) {
llvm::SmallString<256> Name;
getMangleContext().mangleCXXDtor(D, Type, Name);
Name += '\0';
return UniqueMangledName(Name.begin(), Name.end());
}
llvm::Constant *
CodeGenFunction::GenerateThunk(llvm::Function *Fn, GlobalDecl GD,
bool Extern,
const ThunkAdjustment &ThisAdjustment) {
return GenerateCovariantThunk(Fn, GD, Extern,
CovariantThunkAdjustment(ThisAdjustment,
ThunkAdjustment()));
}
llvm::Value *
CodeGenFunction::DynamicTypeAdjust(llvm::Value *V,
const ThunkAdjustment &Adjustment) {
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(VMContext);
const llvm::Type *OrigTy = V->getType();
if (Adjustment.NonVirtual) {
// Do the non-virtual adjustment
V = Builder.CreateBitCast(V, Int8PtrTy);
V = Builder.CreateConstInBoundsGEP1_64(V, Adjustment.NonVirtual);
V = Builder.CreateBitCast(V, OrigTy);
}
if (!Adjustment.Virtual)
return V;
assert(Adjustment.Virtual % (LLVMPointerWidth / 8) == 0 &&
"vtable entry unaligned");
// Do the virtual this adjustment
const llvm::Type *PtrDiffTy = ConvertType(getContext().getPointerDiffType());
const llvm::Type *PtrDiffPtrTy = PtrDiffTy->getPointerTo();
llvm::Value *ThisVal = Builder.CreateBitCast(V, Int8PtrTy);
V = Builder.CreateBitCast(V, PtrDiffPtrTy->getPointerTo());
V = Builder.CreateLoad(V, "vtable");
llvm::Value *VTablePtr = V;
uint64_t VirtualAdjustment = Adjustment.Virtual / (LLVMPointerWidth / 8);
V = Builder.CreateConstInBoundsGEP1_64(VTablePtr, VirtualAdjustment);
V = Builder.CreateLoad(V);
V = Builder.CreateGEP(ThisVal, V);
return Builder.CreateBitCast(V, OrigTy);
}
llvm::Constant *
CodeGenFunction::GenerateCovariantThunk(llvm::Function *Fn,
GlobalDecl GD, bool Extern,
const CovariantThunkAdjustment &Adjustment) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
QualType ResultType = FPT->getResultType();
FunctionArgList Args;
ImplicitParamDecl *ThisDecl =
ImplicitParamDecl::Create(getContext(), 0, SourceLocation(), 0,
MD->getThisType(getContext()));
Args.push_back(std::make_pair(ThisDecl, ThisDecl->getType()));
for (FunctionDecl::param_const_iterator i = MD->param_begin(),
e = MD->param_end();
i != e; ++i) {
ParmVarDecl *D = *i;
Args.push_back(std::make_pair(D, D->getType()));
}
IdentifierInfo *II
= &CGM.getContext().Idents.get("__thunk_named_foo_");
FunctionDecl *FD = FunctionDecl::Create(getContext(),
getContext().getTranslationUnitDecl(),
SourceLocation(), II, ResultType, 0,
Extern
? FunctionDecl::Extern
: FunctionDecl::Static,
false, true);
StartFunction(FD, ResultType, Fn, Args, SourceLocation());
// generate body
const llvm::Type *Ty =
CGM.getTypes().GetFunctionType(CGM.getTypes().getFunctionInfo(MD),
FPT->isVariadic());
llvm::Value *Callee = CGM.GetAddrOfFunction(GD, Ty);
CallArgList CallArgs;
bool ShouldAdjustReturnPointer = true;
QualType ArgType = MD->getThisType(getContext());
llvm::Value *Arg = Builder.CreateLoad(LocalDeclMap[ThisDecl], "this");
if (!Adjustment.ThisAdjustment.isEmpty()) {
// Do the this adjustment.
const llvm::Type *OrigTy = Callee->getType();
Arg = DynamicTypeAdjust(Arg, Adjustment.ThisAdjustment);
if (!Adjustment.ReturnAdjustment.isEmpty()) {
const CovariantThunkAdjustment &ReturnAdjustment =
CovariantThunkAdjustment(ThunkAdjustment(),
Adjustment.ReturnAdjustment);
Callee = CGM.BuildCovariantThunk(GD, Extern, ReturnAdjustment);
Callee = Builder.CreateBitCast(Callee, OrigTy);
ShouldAdjustReturnPointer = false;
}
}
CallArgs.push_back(std::make_pair(RValue::get(Arg), ArgType));
for (FunctionDecl::param_const_iterator i = MD->param_begin(),
e = MD->param_end();
i != e; ++i) {
ParmVarDecl *D = *i;
QualType ArgType = D->getType();
// llvm::Value *Arg = CGF.GetAddrOfLocalVar(Dst);
Expr *Arg = new (getContext()) DeclRefExpr(D, ArgType.getNonReferenceType(),
SourceLocation());
CallArgs.push_back(std::make_pair(EmitCallArg(Arg, ArgType), ArgType));
}
RValue RV = EmitCall(CGM.getTypes().getFunctionInfo(ResultType, CallArgs,
FPT->getCallConv(),
FPT->getNoReturnAttr()),
Callee, ReturnValueSlot(), CallArgs, MD);
if (ShouldAdjustReturnPointer && !Adjustment.ReturnAdjustment.isEmpty()) {
bool CanBeZero = !(ResultType->isReferenceType()
// FIXME: attr nonnull can't be zero either
/* || ResultType->hasAttr<NonNullAttr>() */ );
// Do the return result adjustment.
if (CanBeZero) {
llvm::BasicBlock *NonZeroBlock = createBasicBlock();
llvm::BasicBlock *ZeroBlock = createBasicBlock();
llvm::BasicBlock *ContBlock = createBasicBlock();
const llvm::Type *Ty = RV.getScalarVal()->getType();
llvm::Value *Zero = llvm::Constant::getNullValue(Ty);
Builder.CreateCondBr(Builder.CreateICmpNE(RV.getScalarVal(), Zero),
NonZeroBlock, ZeroBlock);
EmitBlock(NonZeroBlock);
llvm::Value *NZ =
DynamicTypeAdjust(RV.getScalarVal(), Adjustment.ReturnAdjustment);
EmitBranch(ContBlock);
EmitBlock(ZeroBlock);
llvm::Value *Z = RV.getScalarVal();
EmitBlock(ContBlock);
llvm::PHINode *RVOrZero = Builder.CreatePHI(Ty);
RVOrZero->reserveOperandSpace(2);
RVOrZero->addIncoming(NZ, NonZeroBlock);
RVOrZero->addIncoming(Z, ZeroBlock);
RV = RValue::get(RVOrZero);
} else
RV = RValue::get(DynamicTypeAdjust(RV.getScalarVal(),
Adjustment.ReturnAdjustment));
}
if (!ResultType->isVoidType())
EmitReturnOfRValue(RV, ResultType);
FinishFunction();
return Fn;
}
llvm::Constant *
CodeGenModule::GetAddrOfThunk(GlobalDecl GD,
const ThunkAdjustment &ThisAdjustment) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
// Compute mangled name
llvm::SmallString<256> OutName;
if (const CXXDestructorDecl* DD = dyn_cast<CXXDestructorDecl>(MD))
getMangleContext().mangleCXXDtorThunk(DD, GD.getDtorType(), ThisAdjustment,
OutName);
else
getMangleContext().mangleThunk(MD, ThisAdjustment, OutName);
OutName += '\0';
const char* Name = UniqueMangledName(OutName.begin(), OutName.end());
// Get function for mangled name
const llvm::Type *Ty = getTypes().GetFunctionTypeForVtable(MD);
return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl());
}
llvm::Constant *
CodeGenModule::GetAddrOfCovariantThunk(GlobalDecl GD,
const CovariantThunkAdjustment &Adjustment) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
// Compute mangled name
llvm::SmallString<256> OutName;
getMangleContext().mangleCovariantThunk(MD, Adjustment, OutName);
OutName += '\0';
const char* Name = UniqueMangledName(OutName.begin(), OutName.end());
// Get function for mangled name
const llvm::Type *Ty = getTypes().GetFunctionTypeForVtable(MD);
return GetOrCreateLLVMFunction(Name, Ty, GlobalDecl());
}
void CodeGenModule::BuildThunksForVirtual(GlobalDecl GD) {
CGVtableInfo::AdjustmentVectorTy *AdjPtr = getVtableInfo().getAdjustments(GD);
if (!AdjPtr)
return;
CGVtableInfo::AdjustmentVectorTy &Adj = *AdjPtr;
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
for (unsigned i = 0; i < Adj.size(); i++) {
GlobalDecl OGD = Adj[i].first;
const CXXMethodDecl *OMD = cast<CXXMethodDecl>(OGD.getDecl());
QualType nc_oret = OMD->getType()->getAs<FunctionType>()->getResultType();
CanQualType oret = getContext().getCanonicalType(nc_oret);
QualType nc_ret = MD->getType()->getAs<FunctionType>()->getResultType();
CanQualType ret = getContext().getCanonicalType(nc_ret);
ThunkAdjustment ReturnAdjustment;
if (oret != ret) {
QualType qD = nc_ret->getPointeeType();
QualType qB = nc_oret->getPointeeType();
CXXRecordDecl *D = cast<CXXRecordDecl>(qD->getAs<RecordType>()->getDecl());
CXXRecordDecl *B = cast<CXXRecordDecl>(qB->getAs<RecordType>()->getDecl());
ReturnAdjustment = ComputeThunkAdjustment(D, B);
}
ThunkAdjustment ThisAdjustment = Adj[i].second;
bool Extern = !cast<CXXRecordDecl>(OMD->getDeclContext())->isInAnonymousNamespace();
if (!ReturnAdjustment.isEmpty() || !ThisAdjustment.isEmpty()) {
CovariantThunkAdjustment CoAdj(ThisAdjustment, ReturnAdjustment);
llvm::Constant *FnConst;
if (!ReturnAdjustment.isEmpty())
FnConst = GetAddrOfCovariantThunk(GD, CoAdj);
else
FnConst = GetAddrOfThunk(GD, ThisAdjustment);
if (!isa<llvm::Function>(FnConst)) {
llvm::Constant *SubExpr =
cast<llvm::ConstantExpr>(FnConst)->getOperand(0);
llvm::Function *OldFn = cast<llvm::Function>(SubExpr);
std::string Name = OldFn->getNameStr();
GlobalDeclMap.erase(UniqueMangledName(Name.data(),
Name.data() + Name.size() + 1));
llvm::Constant *NewFnConst;
if (!ReturnAdjustment.isEmpty())
NewFnConst = GetAddrOfCovariantThunk(GD, CoAdj);
else
NewFnConst = GetAddrOfThunk(GD, ThisAdjustment);
llvm::Function *NewFn = cast<llvm::Function>(NewFnConst);
NewFn->takeName(OldFn);
llvm::Constant *NewPtrForOldDecl =
llvm::ConstantExpr::getBitCast(NewFn, OldFn->getType());
OldFn->replaceAllUsesWith(NewPtrForOldDecl);
OldFn->eraseFromParent();
FnConst = NewFn;
}
llvm::Function *Fn = cast<llvm::Function>(FnConst);
if (Fn->isDeclaration()) {
llvm::GlobalVariable::LinkageTypes linktype;
linktype = llvm::GlobalValue::WeakAnyLinkage;
if (!Extern)
linktype = llvm::GlobalValue::InternalLinkage;
Fn->setLinkage(linktype);
if (!Features.Exceptions && !Features.ObjCNonFragileABI)
Fn->addFnAttr(llvm::Attribute::NoUnwind);
Fn->setAlignment(2);
CodeGenFunction(*this).GenerateCovariantThunk(Fn, GD, Extern, CoAdj);
}
}
}
}
llvm::Constant *
CodeGenModule::BuildThunk(GlobalDecl GD, bool Extern,
const ThunkAdjustment &ThisAdjustment) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
llvm::SmallString<256> OutName;
if (const CXXDestructorDecl *D = dyn_cast<CXXDestructorDecl>(MD)) {
getMangleContext().mangleCXXDtorThunk(D, GD.getDtorType(), ThisAdjustment,
OutName);
} else
getMangleContext().mangleThunk(MD, ThisAdjustment, OutName);
llvm::GlobalVariable::LinkageTypes linktype;
linktype = llvm::GlobalValue::WeakAnyLinkage;
if (!Extern)
linktype = llvm::GlobalValue::InternalLinkage;
llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0);
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
const llvm::FunctionType *FTy =
getTypes().GetFunctionType(getTypes().getFunctionInfo(MD),
FPT->isVariadic());
llvm::Function *Fn = llvm::Function::Create(FTy, linktype, OutName.str(),
&getModule());
CodeGenFunction(*this).GenerateThunk(Fn, GD, Extern, ThisAdjustment);
llvm::Constant *m = llvm::ConstantExpr::getBitCast(Fn, Ptr8Ty);
return m;
}
llvm::Constant *
CodeGenModule::BuildCovariantThunk(const GlobalDecl &GD, bool Extern,
const CovariantThunkAdjustment &Adjustment) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
llvm::SmallString<256> OutName;
getMangleContext().mangleCovariantThunk(MD, Adjustment, OutName);
llvm::GlobalVariable::LinkageTypes linktype;
linktype = llvm::GlobalValue::WeakAnyLinkage;
if (!Extern)
linktype = llvm::GlobalValue::InternalLinkage;
llvm::Type *Ptr8Ty=llvm::PointerType::get(llvm::Type::getInt8Ty(VMContext),0);
const FunctionProtoType *FPT = MD->getType()->getAs<FunctionProtoType>();
const llvm::FunctionType *FTy =
getTypes().GetFunctionType(getTypes().getFunctionInfo(MD),
FPT->isVariadic());
llvm::Function *Fn = llvm::Function::Create(FTy, linktype, OutName.str(),
&getModule());
CodeGenFunction(*this).GenerateCovariantThunk(Fn, MD, Extern, Adjustment);
llvm::Constant *m = llvm::ConstantExpr::getBitCast(Fn, Ptr8Ty);
return m;
}
static llvm::Value *BuildVirtualCall(CodeGenFunction &CGF, uint64_t VtableIndex,
llvm::Value *This, const llvm::Type *Ty) {
Ty = Ty->getPointerTo()->getPointerTo()->getPointerTo();
llvm::Value *Vtable = CGF.Builder.CreateBitCast(This, Ty);
Vtable = CGF.Builder.CreateLoad(Vtable);
llvm::Value *VFuncPtr =
CGF.Builder.CreateConstInBoundsGEP1_64(Vtable, VtableIndex, "vfn");
return CGF.Builder.CreateLoad(VFuncPtr);
}
llvm::Value *
CodeGenFunction::BuildVirtualCall(const CXXMethodDecl *MD, llvm::Value *This,
const llvm::Type *Ty) {
MD = MD->getCanonicalDecl();
uint64_t VtableIndex = CGM.getVtableInfo().getMethodVtableIndex(MD);
return ::BuildVirtualCall(*this, VtableIndex, This, Ty);
}
llvm::Value *
CodeGenFunction::BuildVirtualCall(const CXXDestructorDecl *DD, CXXDtorType Type,
llvm::Value *&This, const llvm::Type *Ty) {
DD = cast<CXXDestructorDecl>(DD->getCanonicalDecl());
uint64_t VtableIndex =
CGM.getVtableInfo().getMethodVtableIndex(GlobalDecl(DD, Type));
return ::BuildVirtualCall(*this, VtableIndex, This, Ty);
}