From e376441786f994d7d3f27817e163d226d31b641e Mon Sep 17 00:00:00 2001 From: Evgeniy Stepanov Date: Fri, 24 Oct 2014 23:34:15 +0000 Subject: [PATCH] [msan] Make -msan-check-constant-shadow a bit stronger. Allow (under the experimental flag) non-Instructions to participate in MSan checks. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@220601 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../Instrumentation/MemorySanitizer.cpp | 13 ++++++++++--- .../MemorySanitizer/check-constant-shadow.ll | 15 +++++++++++++++ 2 files changed, 25 insertions(+), 3 deletions(-) create mode 100644 test/Instrumentation/MemorySanitizer/check-constant-shadow.ll diff --git a/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/lib/Transforms/Instrumentation/MemorySanitizer.cpp index 9f20b66f7bb..4a7669fe5d0 100644 --- a/lib/Transforms/Instrumentation/MemorySanitizer.cpp +++ b/lib/Transforms/Instrumentation/MemorySanitizer.cpp @@ -1062,9 +1062,16 @@ struct MemorySanitizerVisitor : public InstVisitor { /// UMR warning in runtime if the value is not fully defined. void insertShadowCheck(Value *Val, Instruction *OrigIns) { assert(Val); - Instruction *Shadow = dyn_cast_or_null(getShadow(Val)); - if (!Shadow) return; - Instruction *Origin = dyn_cast_or_null(getOrigin(Val)); + Value *Shadow, *Origin; + if (ClCheckConstantShadow) { + Shadow = getShadow(Val); + if (!Shadow) return; + Origin = getOrigin(Val); + } else { + Shadow = dyn_cast_or_null(getShadow(Val)); + if (!Shadow) return; + Origin = dyn_cast_or_null(getOrigin(Val)); + } insertShadowCheck(Shadow, Origin, OrigIns); } diff --git a/test/Instrumentation/MemorySanitizer/check-constant-shadow.ll b/test/Instrumentation/MemorySanitizer/check-constant-shadow.ll new file mode 100644 index 00000000000..11e44106d8f --- /dev/null +++ b/test/Instrumentation/MemorySanitizer/check-constant-shadow.ll @@ -0,0 +1,15 @@ +; RUN: opt < %s -msan -msan-check-constant-shadow=1 -S | FileCheck %s + +target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128" +target triple = "x86_64-unknown-linux-gnu" + +; Test that returning a literal undef from main() triggers an MSan warning. + +define i32 @main() nounwind uwtable sanitize_memory { +entry: + ret i32 undef +} + +; CHECK-LABEL: @main +; CHECK: call void @__msan_warning_noreturn +; CHECK: ret i32 undef