From: Matt Morehouse <mascasa@google.com>
Date: Fri, 23 Mar 2018 23:35:28 +0000 (+0000)
Subject: [libFuzzer] Use OptForFuzzing attribute with -fsanitize=fuzzer.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=3fe656f58661055a10ee1cc3d131b5b683f4bcb7;p=clang

[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

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@328384 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index c5de16bc6e..3d7b906587 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -862,6 +862,10 @@ void CodeGenFunction::StartFunction(GlobalDecl GD,
   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)) {