Page MenuHomePhabricator
Differential D71913 Diff 240042 clang/lib/CodeGen/ItaniumCXXABI.cpp

Changeset View

Standalone View

View Options

clang/lib/CodeGen/ItaniumCXXABI.cpp

Show First 20 Lines • Show All 664 Lines • ▼ Show 20 LinesCGCallee ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(
// Check the address of the function pointer if CFI on member function // Check the address of the function pointer if CFI on member function
// pointers is enabled. // pointers is enabled.
llvm::Constant *CheckSourceLocation; llvm::Constant *CheckSourceLocation;
llvm::Constant *CheckTypeDesc; llvm::Constant *CheckTypeDesc;
bool ShouldEmitCFICheck = CGF.SanOpts.has(SanitizerKind::CFIMFCall) && bool ShouldEmitCFICheck = CGF.SanOpts.has(SanitizerKind::CFIMFCall) &&
CGM.HasHiddenLTOVisibility(RD); CGM.HasHiddenLTOVisibility(RD);
bool ShouldEmitVFEInfo = CGM.getCodeGenOpts().VirtualFunctionElimination && bool ShouldEmitVFEInfo = CGM.getCodeGenOpts().VirtualFunctionElimination &&
CGM.HasHiddenLTOVisibility(RD); CGM.HasHiddenLTOVisibility(RD);
bool ShouldEmitWPDInfo =
CGM.getCodeGenOpts().WholeProgramVTables &&
// Don't insert type tests if we are forcing public std visibility.
!CGM.HasLTOVisibilityPublicStd(RD);
llvm::Value *VirtualFn = nullptr; llvm::Value *VirtualFn = nullptr;
{ {
CodeGenFunction::SanitizerScope SanScope(&CGF); CodeGenFunction::SanitizerScope SanScope(&CGF);
llvm::Value *TypeId = nullptr; llvm::Value *TypeId = nullptr;
llvm::Value *CheckResult = nullptr; llvm::Value *CheckResult = nullptr;
if (ShouldEmitCFICheck || ShouldEmitVFEInfo) { if (ShouldEmitCFICheck || ShouldEmitVFEInfo || ShouldEmitWPDInfo) {
// If doing CFI or VFE, we will need the metadata node to check against. // If doing CFI, VFE or WPD, we will need the metadata node to check
// against.
llvm::Metadata *MD = llvm::Metadata *MD =
CGM.CreateMetadataIdentifierForVirtualMemPtrType(QualType(MPT, 0)); CGM.CreateMetadataIdentifierForVirtualMemPtrType(QualType(MPT, 0));
TypeId = llvm::MetadataAsValue::get(CGF.getLLVMContext(), MD); TypeId = llvm::MetadataAsValue::get(CGF.getLLVMContext(), MD);
} }
llvm::Value *VFPAddr = Builder.CreateGEP(VTable, VTableOffset); llvm::Value *VFPAddr = Builder.CreateGEP(VTable, VTableOffset);
if (ShouldEmitVFEInfo) { if (ShouldEmitVFEInfo) {
// If doing VFE, load from the vtable with a type.checked.load intrinsic // 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 // 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 // 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 // vtable slot of the correct type is marked with matching metadata, and
// we know that the load must be from one of these slots. // we know that the load must be from one of these slots.
llvm::Value *CheckedLoad = Builder.CreateCall( llvm::Value *CheckedLoad = Builder.CreateCall(
CGM.getIntrinsic(llvm::Intrinsic::type_checked_load), CGM.getIntrinsic(llvm::Intrinsic::type_checked_load),
{VFPAddr, llvm::ConstantInt::get(CGM.Int32Ty, 0), TypeId}); {VFPAddr, llvm::ConstantInt::get(CGM.Int32Ty, 0), TypeId});
CheckResult = Builder.CreateExtractValue(CheckedLoad, 1); CheckResult = Builder.CreateExtractValue(CheckedLoad, 1);
VirtualFn = Builder.CreateExtractValue(CheckedLoad, 0); VirtualFn = Builder.CreateExtractValue(CheckedLoad, 0);
VirtualFn = Builder.CreateBitCast(VirtualFn, FTy->getPointerTo(), VirtualFn = Builder.CreateBitCast(VirtualFn, FTy->getPointerTo(),
"memptr.virtualfn"); "memptr.virtualfn");
} else { } else {
// When not doing VFE, emit a normal load, as it allows more // When not doing VFE, emit a normal load, as it allows more
// optimisations than type.checked.load. // optimisations than type.checked.load.
if (ShouldEmitCFICheck) { if (ShouldEmitCFICheck || ShouldEmitWPDInfo) {
CheckResult = Builder.CreateCall( CheckResult = Builder.CreateCall(
CGM.getIntrinsic(llvm::Intrinsic::type_test), CGM.getIntrinsic(llvm::Intrinsic::type_test),
{Builder.CreateBitCast(VFPAddr, CGF.Int8PtrTy), TypeId}); {Builder.CreateBitCast(VFPAddr, CGF.Int8PtrTy), TypeId});
} }
VFPAddr = VFPAddr =
Builder.CreateBitCast(VFPAddr, FTy->getPointerTo()->getPointerTo()); Builder.CreateBitCast(VFPAddr, FTy->getPointerTo()->getPointerTo());
VirtualFn = Builder.CreateAlignedLoad(VFPAddr, CGF.getPointerAlign(), VirtualFn = Builder.CreateAlignedLoad(VFPAddr, CGF.getPointerAlign(),
"memptr.virtualfn"); "memptr.virtualfn");
} }
assert(VirtualFn && "Virtual fuction pointer not created!"); assert(VirtualFn && "Virtual fuction pointer not created!");
assert((!ShouldEmitCFICheck || !ShouldEmitVFEInfo || CheckResult) && assert((!ShouldEmitCFICheck || !ShouldEmitVFEInfo || !ShouldEmitWPDInfo ||
CheckResult) &&
"Check result required but not created!"); "Check result required but not created!");
if (ShouldEmitCFICheck) { if (ShouldEmitCFICheck) {
// If doing CFI, emit the check. // If doing CFI, emit the check.
CheckSourceLocation = CGF.EmitCheckSourceLocation(E->getBeginLoc()); CheckSourceLocation = CGF.EmitCheckSourceLocation(E->getBeginLoc());
CheckTypeDesc = CGF.EmitCheckTypeDescriptor(QualType(MPT, 0)); CheckTypeDesc = CGF.EmitCheckTypeDescriptor(QualType(MPT, 0));
llvm::Constant *StaticData[] = { llvm::Constant *StaticData[] = {
llvm::ConstantInt::get(CGF.Int8Ty, CodeGenFunction::CFITCK_VMFCall), llvm::ConstantInt::get(CGF.Int8Ty, CodeGenFunction::CFITCK_VMFCall),
▲ Show 20 Lines • Show All 3,679 Lines • Show Last 20 Lines