From 1ef49218b31145c6b0d1d1095a4be2103c93e4ce Mon Sep 17 00:00:00 2001 From: Reid Kleckner Date: Thu, 23 Apr 2015 18:07:13 +0000 Subject: [PATCH] Don't emit lifetime markers when msan is enabled In r235553, Clang started emitting lifetime markers more often. This caused false negative in MSan, because MSan only poisons all allocas once at function entry. Eventually, MSan should poison allocas at lifetime start and probably also lifetime end, but until then, let's not emit markers that aren't going to be useful. llvm-svn: 235613 --- clang/lib/CodeGen/CGDecl.cpp | 5 +++++ clang/test/CodeGen/cleanup-destslot-simple.c | 10 +++++++--- 2 files changed, 12 insertions(+), 3 deletions(-) diff --git a/clang/lib/CodeGen/CGDecl.cpp b/clang/lib/CodeGen/CGDecl.cpp index 29c631514661..874cf6938090 100644 --- a/clang/lib/CodeGen/CGDecl.cpp +++ b/clang/lib/CodeGen/CGDecl.cpp @@ -856,6 +856,11 @@ llvm::Value *CodeGenFunction::EmitLifetimeStart(uint64_t Size, if (CGM.getCodeGenOpts().OptimizationLevel == 0) return nullptr; + // Disable lifetime markers in msan builds. + // FIXME: Remove this when msan works with lifetime markers. + if (getLangOpts().Sanitize.has(SanitizerKind::Memory)) + return nullptr; + llvm::Value *SizeV = llvm::ConstantInt::get(Int64Ty, Size); llvm::Value *Args[] = { SizeV, diff --git a/clang/test/CodeGen/cleanup-destslot-simple.c b/clang/test/CodeGen/cleanup-destslot-simple.c index 0ee52e1d9fa9..bae97c81cbba 100644 --- a/clang/test/CodeGen/cleanup-destslot-simple.c +++ b/clang/test/CodeGen/cleanup-destslot-simple.c @@ -1,4 +1,8 @@ -// RUN: %clang_cc1 -O1 -triple x86_64-none-linux-gnu -emit-llvm -gline-tables-only %s -o - | FileCheck %s +// RUN: %clang_cc1 -O1 -triple x86_64-none-linux-gnu -emit-llvm -gline-tables-only %s -o - | FileCheck %s --check-prefix=CHECK --check-prefix=LIFETIME + +// We shouldn't have markers at -O0 or with msan. +// RUN: %clang_cc1 -O0 -triple x86_64-none-linux-gnu -emit-llvm -gline-tables-only %s -o - | FileCheck %s --check-prefix=CHECK +// RUN: %clang_cc1 -O1 -triple x86_64-none-linux-gnu -emit-llvm -gline-tables-only %s -o - -fsanitize=memory | FileCheck %s --check-prefix=CHECK // There is no exception to handle here, lifetime.end is not a destructor, // so there is no need have cleanup dest slot related code @@ -9,7 +13,7 @@ int test() { return *p; // CHECK: [[X:%.*]] = alloca i32 // CHECK: [[P:%.*]] = alloca i32* -// CHECK: call void @llvm.lifetime.start(i64 4, i8* %{{.*}}) -// CHECK: call void @llvm.lifetime.start(i64 8, i8* %{{.*}}) +// LIFETIME: call void @llvm.lifetime.start(i64 4, i8* %{{.*}}) +// LIFETIME: call void @llvm.lifetime.start(i64 8, i8* %{{.*}}) // CHECK-NOT: store i32 %{{.*}}, i32* %cleanup.dest.slot }