CodeGen: Clean up implementation of vtable initializer builder. NFC.
- Simplify signature of CreateVTableInitializer function.
- Move vtable component builder to a separate function.
- Remove unnecessary accessors from VTableLayout class.
This is in preparation for a future change that will alter the type of the
vtable initializer.
Differential Revision: https://reviews.llvm.org/D22642
llvm-svn: 280897
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index 32ebc08..e1bf1db 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -517,139 +517,121 @@
emitThunk(GD, Thunk, /*ForVTable=*/false);
}
-llvm::Constant *CodeGenVTables::CreateVTableInitializer(
- const CXXRecordDecl *RD, const VTableComponent *Components,
- unsigned NumComponents, const VTableLayout::VTableThunkTy *VTableThunks,
- unsigned NumVTableThunks, llvm::Constant *RTTI) {
- SmallVector<llvm::Constant *, 64> Inits;
+llvm::Constant *CodeGenVTables::CreateVTableComponent(
+ unsigned Idx, const VTableLayout &VTLayout, llvm::Constant *RTTI,
+ unsigned &NextVTableThunkIndex) {
+ VTableComponent Component = VTLayout.vtable_components()[Idx];
- llvm::Type *Int8PtrTy = CGM.Int8PtrTy;
-
- llvm::Type *PtrDiffTy =
- CGM.getTypes().ConvertType(CGM.getContext().getPointerDiffType());
+ auto OffsetConstant = [&](CharUnits Offset) {
+ return llvm::ConstantExpr::getIntToPtr(
+ llvm::ConstantInt::get(CGM.PtrDiffTy, Offset.getQuantity()),
+ CGM.Int8PtrTy);
+ };
- unsigned NextVTableThunkIndex = 0;
+ switch (Component.getKind()) {
+ case VTableComponent::CK_VCallOffset:
+ return OffsetConstant(Component.getVCallOffset());
- llvm::Constant *PureVirtualFn = nullptr, *DeletedVirtualFn = nullptr;
+ case VTableComponent::CK_VBaseOffset:
+ return OffsetConstant(Component.getVBaseOffset());
- for (unsigned I = 0; I != NumComponents; ++I) {
- VTableComponent Component = Components[I];
+ case VTableComponent::CK_OffsetToTop:
+ return OffsetConstant(Component.getOffsetToTop());
- llvm::Constant *Init = nullptr;
+ case VTableComponent::CK_RTTI:
+ return RTTI;
+ case VTableComponent::CK_FunctionPointer:
+ case VTableComponent::CK_CompleteDtorPointer:
+ case VTableComponent::CK_DeletingDtorPointer: {
+ GlobalDecl GD;
+
+ // Get the right global decl.
switch (Component.getKind()) {
- case VTableComponent::CK_VCallOffset:
- Init = llvm::ConstantInt::get(PtrDiffTy,
- Component.getVCallOffset().getQuantity());
- Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy);
- break;
- case VTableComponent::CK_VBaseOffset:
- Init = llvm::ConstantInt::get(PtrDiffTy,
- Component.getVBaseOffset().getQuantity());
- Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy);
- break;
- case VTableComponent::CK_OffsetToTop:
- Init = llvm::ConstantInt::get(PtrDiffTy,
- Component.getOffsetToTop().getQuantity());
- Init = llvm::ConstantExpr::getIntToPtr(Init, Int8PtrTy);
- break;
- case VTableComponent::CK_RTTI:
- Init = llvm::ConstantExpr::getBitCast(RTTI, Int8PtrTy);
- break;
+ default:
+ llvm_unreachable("Unexpected vtable component kind");
case VTableComponent::CK_FunctionPointer:
+ GD = Component.getFunctionDecl();
+ break;
case VTableComponent::CK_CompleteDtorPointer:
- case VTableComponent::CK_DeletingDtorPointer: {
- GlobalDecl GD;
-
- // Get the right global decl.
- switch (Component.getKind()) {
- default:
- llvm_unreachable("Unexpected vtable component kind");
- case VTableComponent::CK_FunctionPointer:
- GD = Component.getFunctionDecl();
- break;
- case VTableComponent::CK_CompleteDtorPointer:
- GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Complete);
- break;
- case VTableComponent::CK_DeletingDtorPointer:
- GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Deleting);
- break;
- }
-
- if (CGM.getLangOpts().CUDA) {
- // Emit NULL for methods we can't codegen on this
- // side. Otherwise we'd end up with vtable with unresolved
- // references.
- const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
- // OK on device side: functions w/ __device__ attribute
- // OK on host side: anything except __device__-only functions.
- bool CanEmitMethod = CGM.getLangOpts().CUDAIsDevice
- ? MD->hasAttr<CUDADeviceAttr>()
- : (MD->hasAttr<CUDAHostAttr>() ||
- !MD->hasAttr<CUDADeviceAttr>());
- if (!CanEmitMethod) {
- Init = llvm::ConstantExpr::getNullValue(Int8PtrTy);
- break;
- }
- // Method is acceptable, continue processing as usual.
- }
-
- if (cast<CXXMethodDecl>(GD.getDecl())->isPure()) {
- // We have a pure virtual member function.
- if (!PureVirtualFn) {
- llvm::FunctionType *Ty =
- llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
- StringRef PureCallName = CGM.getCXXABI().GetPureVirtualCallName();
- PureVirtualFn = CGM.CreateRuntimeFunction(Ty, PureCallName);
- if (auto *F = dyn_cast<llvm::Function>(PureVirtualFn))
- F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
- PureVirtualFn = llvm::ConstantExpr::getBitCast(PureVirtualFn,
- CGM.Int8PtrTy);
- }
- Init = PureVirtualFn;
- } else if (cast<CXXMethodDecl>(GD.getDecl())->isDeleted()) {
- if (!DeletedVirtualFn) {
- llvm::FunctionType *Ty =
- llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
- StringRef DeletedCallName =
- CGM.getCXXABI().GetDeletedVirtualCallName();
- DeletedVirtualFn = CGM.CreateRuntimeFunction(Ty, DeletedCallName);
- if (auto *F = dyn_cast<llvm::Function>(DeletedVirtualFn))
- F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
- DeletedVirtualFn = llvm::ConstantExpr::getBitCast(DeletedVirtualFn,
- CGM.Int8PtrTy);
- }
- Init = DeletedVirtualFn;
- } else {
- // Check if we should use a thunk.
- if (NextVTableThunkIndex < NumVTableThunks &&
- VTableThunks[NextVTableThunkIndex].first == I) {
- const ThunkInfo &Thunk = VTableThunks[NextVTableThunkIndex].second;
-
- maybeEmitThunkForVTable(GD, Thunk);
- Init = CGM.GetAddrOfThunk(GD, Thunk);
-
- NextVTableThunkIndex++;
- } else {
- llvm::Type *Ty = CGM.getTypes().GetFunctionTypeForVTable(GD);
-
- Init = CGM.GetAddrOfFunction(GD, Ty, /*ForVTable=*/true);
- }
-
- Init = llvm::ConstantExpr::getBitCast(Init, Int8PtrTy);
- }
+ GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Complete);
+ break;
+ case VTableComponent::CK_DeletingDtorPointer:
+ GD = GlobalDecl(Component.getDestructorDecl(), Dtor_Deleting);
break;
}
- case VTableComponent::CK_UnusedFunctionPointer:
- Init = llvm::ConstantExpr::getNullValue(Int8PtrTy);
- break;
+ if (CGM.getLangOpts().CUDA) {
+ // Emit NULL for methods we can't codegen on this
+ // side. Otherwise we'd end up with vtable with unresolved
+ // references.
+ const CXXMethodDecl *MD = cast<CXXMethodDecl>(GD.getDecl());
+ // OK on device side: functions w/ __device__ attribute
+ // OK on host side: anything except __device__-only functions.
+ bool CanEmitMethod =
+ CGM.getLangOpts().CUDAIsDevice
+ ? MD->hasAttr<CUDADeviceAttr>()
+ : (MD->hasAttr<CUDAHostAttr>() || !MD->hasAttr<CUDADeviceAttr>());
+ if (!CanEmitMethod)
+ return llvm::ConstantExpr::getNullValue(CGM.Int8PtrTy);
+ // Method is acceptable, continue processing as usual.
+ }
+
+ auto SpecialVirtualFn = [&](llvm::Constant *&Cache, StringRef Name) {
+ if (!Cache) {
+ llvm::FunctionType *Ty =
+ llvm::FunctionType::get(CGM.VoidTy, /*isVarArg=*/false);
+ Cache = CGM.CreateRuntimeFunction(Ty, Name);
+ if (auto *F = dyn_cast<llvm::Function>(Cache))
+ F->setUnnamedAddr(llvm::GlobalValue::UnnamedAddr::Global);
+ Cache = llvm::ConstantExpr::getBitCast(Cache, CGM.Int8PtrTy);
+ }
+ return Cache;
};
-
- Inits.push_back(Init);
+
+ if (cast<CXXMethodDecl>(GD.getDecl())->isPure())
+ // We have a pure virtual member function.
+ return SpecialVirtualFn(PureVirtualFn,
+ CGM.getCXXABI().GetPureVirtualCallName());
+
+ if (cast<CXXMethodDecl>(GD.getDecl())->isDeleted())
+ return SpecialVirtualFn(DeletedVirtualFn,
+ CGM.getCXXABI().GetDeletedVirtualCallName());
+
+ // Check if we should use a thunk.
+ if (NextVTableThunkIndex < VTLayout.vtable_thunks().size() &&
+ VTLayout.vtable_thunks()[NextVTableThunkIndex].first == Idx) {
+ const ThunkInfo &Thunk =
+ VTLayout.vtable_thunks()[NextVTableThunkIndex].second;
+
+ maybeEmitThunkForVTable(GD, Thunk);
+ NextVTableThunkIndex++;
+ return CGM.GetAddrOfThunk(GD, Thunk);
+ }
+
+ llvm::Type *Ty = CGM.getTypes().GetFunctionTypeForVTable(GD);
+ return CGM.GetAddrOfFunction(GD, Ty, /*ForVTable=*/true);
}
-
- llvm::ArrayType *ArrayType = llvm::ArrayType::get(Int8PtrTy, NumComponents);
+
+ case VTableComponent::CK_UnusedFunctionPointer:
+ return llvm::ConstantExpr::getNullValue(CGM.Int8PtrTy);
+ }
+}
+
+llvm::Constant *
+CodeGenVTables::CreateVTableInitializer(const VTableLayout &VTLayout,
+ llvm::Constant *RTTI) {
+ SmallVector<llvm::Constant *, 64> Inits;
+ unsigned NextVTableThunkIndex = 0;
+
+ for (unsigned I = 0, E = VTLayout.vtable_components().size(); I != E; ++I) {
+ llvm::Constant *Init =
+ CreateVTableComponent(I, VTLayout, RTTI, NextVTableThunkIndex);
+ Inits.push_back(llvm::ConstantExpr::getBitCast(Init, CGM.Int8PtrTy));
+ }
+
+ llvm::ArrayType *ArrayType =
+ llvm::ArrayType::get(CGM.Int8PtrTy, VTLayout.vtable_components().size());
return llvm::ConstantArray::get(ArrayType, Inits);
}
@@ -677,8 +659,8 @@
Base.getBase(), Out);
StringRef Name = OutName.str();
- llvm::ArrayType *ArrayType =
- llvm::ArrayType::get(CGM.Int8PtrTy, VTLayout->getNumVTableComponents());
+ llvm::ArrayType *ArrayType =
+ llvm::ArrayType::get(CGM.Int8PtrTy, VTLayout->vtable_components().size());
// Construction vtable symbols are not part of the Itanium ABI, so we cannot
// guarantee that they actually will be available externally. Instead, when
@@ -700,10 +682,7 @@
CGM.getContext().getTagDeclType(Base.getBase()));
// Create and set the initializer.
- llvm::Constant *Init = CreateVTableInitializer(
- Base.getBase(), VTLayout->vtable_component_begin(),
- VTLayout->getNumVTableComponents(), VTLayout->vtable_thunk_begin(),
- VTLayout->getNumVTableThunks(), RTTI);
+ llvm::Constant *Init = CreateVTableInitializer(*VTLayout, RTTI);
VTable->setInitializer(Init);
CGM.EmitVTableTypeMetadata(VTable, *VTLayout.get());