Revert "Dead Virtual Function Elimination"
This reverts commit 9f6a873268e1ad9855873d9d8007086c0d01cf4f.
llvm-svn: 374844
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 8f9b164..2945dec 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -644,6 +644,8 @@
VTableOffset = Builder.CreateTrunc(VTableOffset, CGF.Int32Ty);
VTableOffset = Builder.CreateZExt(VTableOffset, CGM.PtrDiffTy);
}
+ // Compute the address of the virtual function pointer.
+ llvm::Value *VFPAddr = Builder.CreateGEP(VTable, VTableOffset);
// Check the address of the function pointer if CFI on member function
// pointers is enabled.
@@ -651,81 +653,44 @@
llvm::Constant *CheckTypeDesc;
bool ShouldEmitCFICheck = CGF.SanOpts.has(SanitizerKind::CFIMFCall) &&
CGM.HasHiddenLTOVisibility(RD);
- bool ShouldEmitVFEInfo = CGM.getCodeGenOpts().VirtualFunctionElimination &&
- CGM.HasHiddenLTOVisibility(RD);
- llvm::Value *VirtualFn = nullptr;
-
- {
+ if (ShouldEmitCFICheck) {
CodeGenFunction::SanitizerScope SanScope(&CGF);
- llvm::Value *TypeId = nullptr;
- llvm::Value *CheckResult = nullptr;
- if (ShouldEmitCFICheck || ShouldEmitVFEInfo) {
- // If doing CFI or VFE, we will need the metadata node to check against.
- llvm::Metadata *MD =
- CGM.CreateMetadataIdentifierForVirtualMemPtrType(QualType(MPT, 0));
- TypeId = llvm::MetadataAsValue::get(CGF.getLLVMContext(), MD);
- }
+ CheckSourceLocation = CGF.EmitCheckSourceLocation(E->getBeginLoc());
+ CheckTypeDesc = CGF.EmitCheckTypeDescriptor(QualType(MPT, 0));
+ llvm::Constant *StaticData[] = {
+ llvm::ConstantInt::get(CGF.Int8Ty, CodeGenFunction::CFITCK_VMFCall),
+ CheckSourceLocation,
+ CheckTypeDesc,
+ };
- llvm::Value *VFPAddr = Builder.CreateGEP(VTable, VTableOffset);
+ llvm::Metadata *MD =
+ CGM.CreateMetadataIdentifierForVirtualMemPtrType(QualType(MPT, 0));
+ llvm::Value *TypeId = llvm::MetadataAsValue::get(CGF.getLLVMContext(), MD);
- if (ShouldEmitVFEInfo) {
- // If doing VFE, load from the vtable with a type.checked.load intrinsic
- // call. Note that we use the GEP to calculate the address to load from
- // and pass 0 as the offset to the intrinsic. This is because every
- // vtable slot of the correct type is marked with matching metadata, and
- // we know that the load must be from one of these slots.
- llvm::Value *CheckedLoad = Builder.CreateCall(
- CGM.getIntrinsic(llvm::Intrinsic::type_checked_load),
- {VFPAddr, llvm::ConstantInt::get(CGM.Int32Ty, 0), TypeId});
- CheckResult = Builder.CreateExtractValue(CheckedLoad, 1);
- VirtualFn = Builder.CreateExtractValue(CheckedLoad, 0);
- VirtualFn = Builder.CreateBitCast(VirtualFn, FTy->getPointerTo(),
- "memptr.virtualfn");
+ llvm::Value *TypeTest = Builder.CreateCall(
+ CGM.getIntrinsic(llvm::Intrinsic::type_test), {VFPAddr, TypeId});
+
+ if (CGM.getCodeGenOpts().SanitizeTrap.has(SanitizerKind::CFIMFCall)) {
+ CGF.EmitTrapCheck(TypeTest);
} else {
- // When not doing VFE, emit a normal load, as it allows more
- // optimisations than type.checked.load.
- if (ShouldEmitCFICheck) {
- CheckResult = Builder.CreateCall(
- CGM.getIntrinsic(llvm::Intrinsic::type_test),
- {Builder.CreateBitCast(VFPAddr, CGF.Int8PtrTy), TypeId});
- }
- VFPAddr =
- Builder.CreateBitCast(VFPAddr, FTy->getPointerTo()->getPointerTo());
- VirtualFn = Builder.CreateAlignedLoad(VFPAddr, CGF.getPointerAlign(),
- "memptr.virtualfn");
+ llvm::Value *AllVtables = llvm::MetadataAsValue::get(
+ CGM.getLLVMContext(),
+ llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
+ llvm::Value *ValidVtable = Builder.CreateCall(
+ CGM.getIntrinsic(llvm::Intrinsic::type_test), {VTable, AllVtables});
+ CGF.EmitCheck(std::make_pair(TypeTest, SanitizerKind::CFIMFCall),
+ SanitizerHandler::CFICheckFail, StaticData,
+ {VTable, ValidVtable});
}
- assert(VirtualFn && "Virtual fuction pointer not created!");
- assert((!ShouldEmitCFICheck || !ShouldEmitVFEInfo || CheckResult) &&
- "Check result required but not created!");
- if (ShouldEmitCFICheck) {
- // If doing CFI, emit the check.
- CheckSourceLocation = CGF.EmitCheckSourceLocation(E->getBeginLoc());
- CheckTypeDesc = CGF.EmitCheckTypeDescriptor(QualType(MPT, 0));
- llvm::Constant *StaticData[] = {
- llvm::ConstantInt::get(CGF.Int8Ty, CodeGenFunction::CFITCK_VMFCall),
- CheckSourceLocation,
- CheckTypeDesc,
- };
+ FnVirtual = Builder.GetInsertBlock();
+ }
- if (CGM.getCodeGenOpts().SanitizeTrap.has(SanitizerKind::CFIMFCall)) {
- CGF.EmitTrapCheck(CheckResult);
- } else {
- llvm::Value *AllVtables = llvm::MetadataAsValue::get(
- CGM.getLLVMContext(),
- llvm::MDString::get(CGM.getLLVMContext(), "all-vtables"));
- llvm::Value *ValidVtable = Builder.CreateCall(
- CGM.getIntrinsic(llvm::Intrinsic::type_test), {VTable, AllVtables});
- CGF.EmitCheck(std::make_pair(CheckResult, SanitizerKind::CFIMFCall),
- SanitizerHandler::CFICheckFail, StaticData,
- {VTable, ValidVtable});
- }
-
- FnVirtual = Builder.GetInsertBlock();
- }
- } // End of sanitizer scope
-
+ // Load the virtual function to call.
+ VFPAddr = Builder.CreateBitCast(VFPAddr, FTy->getPointerTo()->getPointerTo());
+ llvm::Value *VirtualFn = Builder.CreateAlignedLoad(
+ VFPAddr, CGF.getPointerAlign(), "memptr.virtualfn");
CGF.EmitBranch(FnEnd);
// In the non-virtual path, the function pointer is actually a
@@ -1669,7 +1634,7 @@
EmitFundamentalRTTIDescriptors(RD);
if (!VTable->isDeclarationForLinker())
- CGM.EmitVTableTypeMetadata(RD, VTable, VTLayout);
+ CGM.EmitVTableTypeMetadata(VTable, VTLayout);
}
bool ItaniumCXXABI::isVirtualOffsetNeededForVTableField(