Author: pcc Date: Mon Jul 31 13:45:14 2017 New Revision: 309622 URL: http://llvm.org/viewvc/llvm-project?rev=309622&view=rev Log: Fix logic for generating llvm.type.test()s
CodeGenFunction::EmitTypeMetadataCodeForVCall() could output an llvm.assume(llvm.type.test())when CFI was enabled, optimizing out the vcall check. This case was only reached when: 1) CFI-vcall was enabled, 2) -fwhole-program-tables was specified, and 3) -fno-sanitize-trap=cfi-vcall was specified. Patch by Vlad Tsyrklevich! Differential Revision: https://reviews.llvm.org/D36013 Added: cfe/trunk/test/CodeGenCXX/cfi-vcall-no-trap.cpp Modified: cfe/trunk/lib/CodeGen/CGClass.cpp Modified: cfe/trunk/lib/CodeGen/CGClass.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGClass.cpp?rev=309622&r1=309621&r2=309622&view=diff ============================================================================== --- cfe/trunk/lib/CodeGen/CGClass.cpp (original) +++ cfe/trunk/lib/CodeGen/CGClass.cpp Mon Jul 31 13:45:14 2017 @@ -2523,8 +2523,10 @@ LeastDerivedClassWithSameLayout(const CX void CodeGenFunction::EmitTypeMetadataCodeForVCall(const CXXRecordDecl *RD, llvm::Value *VTable, SourceLocation Loc) { - if (CGM.getCodeGenOpts().WholeProgramVTables && - CGM.HasHiddenLTOVisibility(RD)) { + if (SanOpts.has(SanitizerKind::CFIVCall)) + EmitVTablePtrCheckForCall(RD, VTable, CodeGenFunction::CFITCK_VCall, Loc); + else if (CGM.getCodeGenOpts().WholeProgramVTables && + CGM.HasHiddenLTOVisibility(RD)) { llvm::Metadata *MD = CGM.CreateMetadataIdentifierForType(QualType(RD->getTypeForDecl(), 0)); llvm::Value *TypeId = @@ -2536,9 +2538,6 @@ void CodeGenFunction::EmitTypeMetadataCo {CastedVTable, TypeId}); Builder.CreateCall(CGM.getIntrinsic(llvm::Intrinsic::assume), TypeTest); } - - if (SanOpts.has(SanitizerKind::CFIVCall)) - EmitVTablePtrCheckForCall(RD, VTable, CodeGenFunction::CFITCK_VCall, Loc); } void CodeGenFunction::EmitVTablePtrCheckForCall(const CXXRecordDecl *RD, Added: cfe/trunk/test/CodeGenCXX/cfi-vcall-no-trap.cpp URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/cfi-vcall-no-trap.cpp?rev=309622&view=auto ============================================================================== --- cfe/trunk/test/CodeGenCXX/cfi-vcall-no-trap.cpp (added) +++ cfe/trunk/test/CodeGenCXX/cfi-vcall-no-trap.cpp Mon Jul 31 13:45:14 2017 @@ -0,0 +1,15 @@ +// Only output llvm.assume(llvm.type.test()) if cfi-vcall is disabled and whole-program-vtables is enabled +// RUN: %clang_cc1 -fvisibility hidden -fsanitize=cfi-vcall -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CHECK --check-prefix=CFI %s +// RUN: %clang_cc1 -fvisibility hidden -fwhole-program-vtables -emit-llvm -o - %s | FileCheck --check-prefix=CHECK --check-prefix=NOCFI %s + +struct S1 { + virtual void f(); +}; + +// CHECK: define{{.*}}s1f +// CHECK: llvm.type.test +// CFI-NOT: llvm.assume +// NOCFI: llvm.assume +void s1f(S1 *s1) { + s1->f(); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits