diff options
| -rw-r--r-- | llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp | 13 | ||||
| -rw-r--r-- | llvm/test/Instrumentation/MemorySanitizer/check-constant-shadow.ll | 15 |
2 files changed, 25 insertions, 3 deletions
diff --git a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp index 9f20b66f7bb..4a7669fe5d0 100644 --- a/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp +++ b/llvm/lib/Transforms/Instrumentation/MemorySanitizer.cpp @@ -1062,9 +1062,16 @@ struct MemorySanitizerVisitor : public InstVisitor<MemorySanitizerVisitor> { /// 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<Instruction>(getShadow(Val)); - if (!Shadow) return; - Instruction *Origin = dyn_cast_or_null<Instruction>(getOrigin(Val)); + Value *Shadow, *Origin; + if (ClCheckConstantShadow) { + Shadow = getShadow(Val); + if (!Shadow) return; + Origin = getOrigin(Val); + } else { + Shadow = dyn_cast_or_null<Instruction>(getShadow(Val)); + if (!Shadow) return; + Origin = dyn_cast_or_null<Instruction>(getOrigin(Val)); + } insertShadowCheck(Shadow, Origin, OrigIns); } diff --git a/llvm/test/Instrumentation/MemorySanitizer/check-constant-shadow.ll b/llvm/test/Instrumentation/MemorySanitizer/check-constant-shadow.ll new file mode 100644 index 00000000000..11e44106d8f --- /dev/null +++ b/llvm/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 |
