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Make emitting a VTT a two-step process, much like emitting a VTable. You first get the address of the VTT, and then pass it to EmitVTTDefinition. 

llvm-svn: 124539
This commit is contained in:
Anders Carlsson 2011-01-29 19:16:51 +00:00
parent 93be9a90cc
commit 883fc72c3c
6 changed files with 49 additions and 54 deletions
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2
clang/lib/CodeGen/CGClass.cpp
View File

@ -318,7 +318,7 @@ static llvm::Value *GetVTTParameter(CodeGenFunction &CGF, GlobalDecl GD,
VTT = CGF.Builder.CreateConstInBoundsGEP1_64(VTT, SubVTTIndex);
} else {
// We're the complete constructor, so get the VTT by name.
VTT = CGF.CGM.getVTables().getVTT(RD);
VTT = CGF.CGM.getVTables().GetAddrOfVTT(RD);
VTT = CGF.Builder.CreateConstInBoundsGEP2_64(VTT, 0, SubVTTIndex);
}

63
clang/lib/CodeGen/CGVTT.cpp
View File

@ -366,58 +366,47 @@ void VTTBuilder::LayoutVTT(BaseSubobject Base, bool BaseIsVirtual) {
}
llvm::GlobalVariable *
CodeGenVTables::GenerateVTT(llvm::GlobalVariable::LinkageTypes Linkage,
bool GenerateDefinition,
void
CodeGenVTables::EmitVTTDefinition(llvm::GlobalVariable *VTT,
llvm::GlobalVariable::LinkageTypes Linkage,
const CXXRecordDecl *RD) {
// Only classes that have virtual bases need a VTT.
if (RD->getNumVBases() == 0)
return 0;
VTTBuilder Builder(CGM, RD, /*GenerateDefinition=*/true);
const llvm::Type *Int8PtrTy = llvm::Type::getInt8PtrTy(CGM.getLLVMContext());
const llvm::ArrayType *ArrayType =
llvm::ArrayType::get(Int8PtrTy, Builder.getVTTComponents().size());
llvm::Constant *Init =
llvm::ConstantArray::get(ArrayType, Builder.getVTTComponents().data(),
Builder.getVTTComponents().size());
VTT->setInitializer(Init);
// Set the correct linkage.
VTT->setLinkage(Linkage);
}
llvm::GlobalVariable *CodeGenVTables::GetAddrOfVTT(const CXXRecordDecl *RD) {
assert(RD->getNumVBases() && "Only classes with virtual bases need a VTT");
llvm::SmallString<256> OutName;
CGM.getCXXABI().getMangleContext().mangleCXXVTT(RD, OutName);
llvm::StringRef Name = OutName.str();
D1(printf("vtt %s\n", RD->getNameAsCString()));
VTTBuilder Builder(CGM, RD, /*GenerateDefinition=*/false);
llvm::GlobalVariable *GV = CGM.getModule().getGlobalVariable(Name, true);
if (GV == 0 || GV->isDeclaration()) {
const llvm::Type *Int8PtrTy =
llvm::Type::getInt8PtrTy(CGM.getLLVMContext());
VTTBuilder Builder(CGM, RD, GenerateDefinition);
const llvm::ArrayType *Type =
const llvm::ArrayType *ArrayType =
llvm::ArrayType::get(Int8PtrTy, Builder.getVTTComponents().size());
llvm::Constant *Init = 0;
if (GenerateDefinition)
Init = llvm::ConstantArray::get(Type, Builder.getVTTComponents().data(),
Builder.getVTTComponents().size());
llvm::GlobalVariable *OldGV = GV;
GV = new llvm::GlobalVariable(CGM.getModule(), Type, /*isConstant=*/true,
Linkage, Init, Name);
CGM.setGlobalVisibility(GV, RD, /*ForDefinition*/ GenerateDefinition);
llvm::GlobalVariable *GV =
CGM.CreateOrReplaceCXXRuntimeVariable(Name, ArrayType,
llvm::GlobalValue::ExternalLinkage);
GV->setUnnamedAddr(true);
if (OldGV) {
GV->takeName(OldGV);
llvm::Constant *NewPtr =
llvm::ConstantExpr::getBitCast(GV, OldGV->getType());
OldGV->replaceAllUsesWith(NewPtr);
OldGV->eraseFromParent();
}
}
return GV;
}
llvm::GlobalVariable *CodeGenVTables::getVTT(const CXXRecordDecl *RD) {
return GenerateVTT(llvm::GlobalValue::ExternalLinkage,
/*GenerateDefinition=*/false, RD);
}
bool CodeGenVTables::needsVTTParameter(GlobalDecl GD) {
const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());

5
clang/lib/CodeGen/CGVTables.cpp
View File

@ -3040,7 +3040,10 @@ CodeGenVTables::GenerateClassData(llvm::GlobalVariable::LinkageTypes Linkage,
VTable = GetAddrOfVTable(RD);
EmitVTableDefinition(VTable, Linkage, RD);
GenerateVTT(Linkage, /*GenerateDefinition=*/true, RD);
if (RD->getNumVBases()) {
llvm::GlobalVariable *VTT = GetAddrOfVTT(RD);
EmitVTTDefinition(VTT, Linkage, RD);
}
// If this is the magic class __cxxabiv1::__fundamental_type_info,
// we will emit the typeinfo for the fundamental types. This is the

13
clang/lib/CodeGen/CGVTables.h
View File

@ -182,10 +182,6 @@ class CodeGenVTables {
void ComputeMethodVTableIndices(const CXXRecordDecl *RD);
llvm::GlobalVariable *GenerateVTT(llvm::GlobalVariable::LinkageTypes Linkage,
bool GenerateDefinition,
const CXXRecordDecl *RD);
/// EmitThunk - Emit a single thunk.
void EmitThunk(GlobalDecl GD, const ThunkInfo &Thunk);
@ -258,7 +254,14 @@ public:
bool BaseIsVirtual,
VTableAddressPointsMapTy& AddressPoints);
llvm::GlobalVariable *getVTT(const CXXRecordDecl *RD);
/// GetAddrOfVTable - Get the address of the VTT for the given record decl.
llvm::GlobalVariable *GetAddrOfVTT(const CXXRecordDecl *RD);
/// EmitVTTDefinition - Emit the definition of the given vtable.
void EmitVTTDefinition(llvm::GlobalVariable *VTT,
llvm::GlobalVariable::LinkageTypes Linkage,
const CXXRecordDecl *RD);
/// EmitThunks - Emit the associated thunks for the given global decl.
void EmitThunks(GlobalDecl GD);

6
clang/test/CodeGenCXX/mangle-subst-std.cpp
View File

@ -3,14 +3,14 @@
// Check mangling of Vtables, VTTs, and construction vtables that
// involve standard substitutions.
// CHECK: @_ZTTSd = linkonce_odr unnamed_addr constant
// CHECK: @_ZTVSd = linkonce_odr unnamed_addr constant
// CHECK: @_ZTCSd0_Si = internal constant
// CHECK: @_ZTCSd16_So = internal constant
// CHECK: @_ZTTSd = linkonce_odr unnamed_addr constant
// CHECK: @_ZTVSo = linkonce_odr unnamed_addr constant
// CHECK: @_ZTTSo = linkonce_odr unnamed_addr constant
// CHECK: @_ZTVSi = linkonce_odr unnamed_addr constant
// CHECK: @_ZTVSo = linkonce_odr unnamed_addr constant
// CHECK: @_ZTTSi = linkonce_odr unnamed_addr constant
// CHECK: @_ZTVSi = linkonce_odr unnamed_addr constant
namespace std {
struct A { A(); };