r328384 - [libFuzzer] Use OptForFuzzing attribute with -fsanitize=fuzzer.

[Matt Morehouse via cfe-commits]

Author: morehouse
Date: Fri Mar 23 16:35:28 2018
New Revision: 328384

URL: http://llvm.org/viewvc/llvm-project?rev=328384&view=rev
Log:
[libFuzzer] Use OptForFuzzing attribute with -fsanitize=fuzzer.

Summary:
Disables certain CMP optimizations to improve fuzzing signal under -O1
and -O2.

Switches all fuzzer tests to -O2 except for a few leak tests where the
leak is optimized out under -O2.

Reviewers: kcc, vitalybuka

Reviewed By: vitalybuka

Subscribers: cfe-commits, llvm-commits

Differential Revision: https://reviews.llvm.org/D44798

Modified:
    cfe/trunk/lib/CodeGen/CodeGenFunction.cpp

Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.cpp?rev=328384&r1=328383&r2=328384&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.cpp Fri Mar 23 16:35:28 2018
@@ -862,6 +862,10 @@ void CodeGenFunction::StartFunction(Glob
   if (SanOpts.has(SanitizerKind::SafeStack))
     Fn->addFnAttr(llvm::Attribute::SafeStack);
 
+  // Apply fuzzing attribute to the function.
+  if (SanOpts.hasOneOf(SanitizerKind::Fuzzer | SanitizerKind::FuzzerNoLink))
+    Fn->addFnAttr(llvm::Attribute::OptForFuzzing);
+
   // Ignore TSan memory acesses from within ObjC/ObjC++ dealloc, initialize,
   // .cxx_destruct, __destroy_helper_block_ and all of their calees at run time.
   if (SanOpts.has(SanitizerKind::Thread)) {