summaryrefslogtreecommitdiffstats
path: root/clang/lib/CodeGen
diff options
context:
space:
mode:
Diffstat (limited to 'clang/lib/CodeGen')
-rw-r--r--clang/lib/CodeGen/CGClass.cpp18
-rw-r--r--clang/lib/CodeGen/CGVTables.cpp35
-rw-r--r--clang/lib/CodeGen/CodeGenModule.h10
-rw-r--r--clang/lib/CodeGen/ItaniumCXXABI.cpp105
4 files changed, 126 insertions, 42 deletions
diff --git a/clang/lib/CodeGen/CGClass.cpp b/clang/lib/CodeGen/CGClass.cpp
index ab8588303d2..7cff6210c29 100644
--- a/clang/lib/CodeGen/CGClass.cpp
+++ b/clang/lib/CodeGen/CGClass.cpp
@@ -2784,11 +2784,16 @@ void CodeGenFunction::EmitVTablePtrCheck(const CXXRecordDecl *RD,
bool CodeGenFunction::ShouldEmitVTableTypeCheckedLoad(const CXXRecordDecl *RD) {
if (!CGM.getCodeGenOpts().WholeProgramVTables ||
- !SanOpts.has(SanitizerKind::CFIVCall) ||
- !CGM.getCodeGenOpts().SanitizeTrap.has(SanitizerKind::CFIVCall) ||
!CGM.HasHiddenLTOVisibility(RD))
return false;
+ if (CGM.getCodeGenOpts().VirtualFunctionElimination)
+ return true;
+
+ if (!SanOpts.has(SanitizerKind::CFIVCall) ||
+ !CGM.getCodeGenOpts().SanitizeTrap.has(SanitizerKind::CFIVCall))
+ return false;
+
std::string TypeName = RD->getQualifiedNameAsString();
return !getContext().getSanitizerBlacklist().isBlacklistedType(
SanitizerKind::CFIVCall, TypeName);
@@ -2811,8 +2816,13 @@ llvm::Value *CodeGenFunction::EmitVTableTypeCheckedLoad(
TypeId});
llvm::Value *CheckResult = Builder.CreateExtractValue(CheckedLoad, 1);
- EmitCheck(std::make_pair(CheckResult, SanitizerKind::CFIVCall),
- SanitizerHandler::CFICheckFail, nullptr, nullptr);
+ std::string TypeName = RD->getQualifiedNameAsString();
+ if (SanOpts.has(SanitizerKind::CFIVCall) &&
+ !getContext().getSanitizerBlacklist().isBlacklistedType(
+ SanitizerKind::CFIVCall, TypeName)) {
+ EmitCheck(std::make_pair(CheckResult, SanitizerKind::CFIVCall),
+ SanitizerHandler::CFICheckFail, {}, {});
+ }
return Builder.CreateBitCast(
Builder.CreateExtractValue(CheckedLoad, 0),
diff --git a/clang/lib/CodeGen/CGVTables.cpp b/clang/lib/CodeGen/CGVTables.cpp
index a74905fd70f..f9f25e7e57a 100644
--- a/clang/lib/CodeGen/CGVTables.cpp
+++ b/clang/lib/CodeGen/CGVTables.cpp
@@ -808,7 +808,7 @@ CodeGenVTables::GenerateConstructionVTable(const CXXRecordDecl *RD,
assert(!VTable->isDeclaration() && "Shouldn't set properties on declaration");
CGM.setGVProperties(VTable, RD);
- CGM.EmitVTableTypeMetadata(VTable, *VTLayout.get());
+ CGM.EmitVTableTypeMetadata(RD, VTable, *VTLayout.get());
return VTable;
}
@@ -1039,7 +1039,32 @@ bool CodeGenModule::HasHiddenLTOVisibility(const CXXRecordDecl *RD) {
return true;
}
-void CodeGenModule::EmitVTableTypeMetadata(llvm::GlobalVariable *VTable,
+llvm::GlobalObject::VCallVisibility
+CodeGenModule::GetVCallVisibilityLevel(const CXXRecordDecl *RD) {
+ LinkageInfo LV = RD->getLinkageAndVisibility();
+ llvm::GlobalObject::VCallVisibility TypeVis;
+ if (!isExternallyVisible(LV.getLinkage()))
+ TypeVis = llvm::GlobalObject::VCallVisibilityTranslationUnit;
+ else if (HasHiddenLTOVisibility(RD))
+ TypeVis = llvm::GlobalObject::VCallVisibilityLinkageUnit;
+ else
+ TypeVis = llvm::GlobalObject::VCallVisibilityPublic;
+
+ for (auto B : RD->bases())
+ if (B.getType()->getAsCXXRecordDecl()->isDynamicClass())
+ TypeVis = std::min(TypeVis,
+ GetVCallVisibilityLevel(B.getType()->getAsCXXRecordDecl()));
+
+ for (auto B : RD->vbases())
+ if (B.getType()->getAsCXXRecordDecl()->isDynamicClass())
+ TypeVis = std::min(TypeVis,
+ GetVCallVisibilityLevel(B.getType()->getAsCXXRecordDecl()));
+
+ return TypeVis;
+}
+
+void CodeGenModule::EmitVTableTypeMetadata(const CXXRecordDecl *RD,
+ llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout) {
if (!getCodeGenOpts().LTOUnit)
return;
@@ -1099,4 +1124,10 @@ void CodeGenModule::EmitVTableTypeMetadata(llvm::GlobalVariable *VTable,
VTable->addTypeMetadata((PointerWidth * I).getQuantity(), MD);
}
}
+
+ if (getCodeGenOpts().VirtualFunctionElimination) {
+ llvm::GlobalObject::VCallVisibility TypeVis = GetVCallVisibilityLevel(RD);
+ if (TypeVis != llvm::GlobalObject::VCallVisibilityPublic)
+ VTable->addVCallVisibilityMetadata(TypeVis);
+ }
}
diff --git a/clang/lib/CodeGen/CodeGenModule.h b/clang/lib/CodeGen/CodeGenModule.h
index 597b8d712ca..73f81adae35 100644
--- a/clang/lib/CodeGen/CodeGenModule.h
+++ b/clang/lib/CodeGen/CodeGenModule.h
@@ -1280,8 +1280,16 @@ public:
/// optimization.
bool HasHiddenLTOVisibility(const CXXRecordDecl *RD);
+ /// Returns the vcall visibility of the given type. This is the scope in which
+ /// a virtual function call could be made which ends up being dispatched to a
+ /// member function of this class. This scope can be wider than the visibility
+ /// of the class itself when the class has a more-visible dynamic base class.
+ llvm::GlobalObject::VCallVisibility
+ GetVCallVisibilityLevel(const CXXRecordDecl *RD);
+
/// Emit type metadata for the given vtable using the given layout.
- void EmitVTableTypeMetadata(llvm::GlobalVariable *VTable,
+ void EmitVTableTypeMetadata(const CXXRecordDecl *RD,
+ llvm::GlobalVariable *VTable,
const VTableLayout &VTLayout);
/// Generate a cross-DSO type identifier for MD.
diff --git a/clang/lib/CodeGen/ItaniumCXXABI.cpp b/clang/lib/CodeGen/ItaniumCXXABI.cpp
index 2945dec0bd7..8f9b16470b6 100644
--- a/clang/lib/CodeGen/ItaniumCXXABI.cpp
+++ b/clang/lib/CodeGen/ItaniumCXXABI.cpp
@@ -644,8 +644,6 @@ CGCallee ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(
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.
@@ -653,44 +651,81 @@ CGCallee ItaniumCXXABI::EmitLoadOfMemberFunctionPointer(
llvm::Constant *CheckTypeDesc;
bool ShouldEmitCFICheck = CGF.SanOpts.has(SanitizerKind::CFIMFCall) &&
CGM.HasHiddenLTOVisibility(RD);
- if (ShouldEmitCFICheck) {
- CodeGenFunction::SanitizerScope SanScope(&CGF);
-
- 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::Metadata *MD =
- CGM.CreateMetadataIdentifierForVirtualMemPtrType(QualType(MPT, 0));
- llvm::Value *TypeId = llvm::MetadataAsValue::get(CGF.getLLVMContext(), MD);
+ bool ShouldEmitVFEInfo = CGM.getCodeGenOpts().VirtualFunctionElimination &&
+ CGM.HasHiddenLTOVisibility(RD);
+ llvm::Value *VirtualFn = nullptr;
- llvm::Value *TypeTest = Builder.CreateCall(
- CGM.getIntrinsic(llvm::Intrinsic::type_test), {VFPAddr, TypeId});
+ {
+ 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);
+ }
- if (CGM.getCodeGenOpts().SanitizeTrap.has(SanitizerKind::CFIMFCall)) {
- CGF.EmitTrapCheck(TypeTest);
+ llvm::Value *VFPAddr = Builder.CreateGEP(VTable, VTableOffset);
+
+ 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");
} 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(TypeTest, SanitizerKind::CFIMFCall),
- SanitizerHandler::CFICheckFail, StaticData,
- {VTable, ValidVtable});
+ // 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");
}
+ 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
@@ -1634,7 +1669,7 @@ void ItaniumCXXABI::emitVTableDefinitions(CodeGenVTables &CGVT,
EmitFundamentalRTTIDescriptors(RD);
if (!VTable->isDeclarationForLinker())
- CGM.EmitVTableTypeMetadata(VTable, VTLayout);
+ CGM.EmitVTableTypeMetadata(RD, VTable, VTLayout);
}
bool ItaniumCXXABI::isVirtualOffsetNeededForVTableField(
OpenPOWER on IntegriCloud