From: Pete Cooper <peter_cooper@apple.com>
Date: Tue, 22 Mar 2016 22:51:03 +0000 (+0000)
Subject: Don't memcpy from a null source.  Found by UBSan
X-Git-Tag: llvmorg-3.9.0-rc1~11199
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=8e1b9a17a692d428eeb16c0189ccbbaa741b366d;p=platform%2Fupstream%2Fllvm.git

Don't memcpy from a null source.  Found by UBSan

llvm-svn: 264114
---

diff --git a/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp b/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
index 34c48a5..03e081a 100644
--- a/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
+++ b/lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp
@@ -1066,6 +1066,8 @@ void MachOFileLayout::appendSymbols(const std::vector<Symbol> &symbols,
 }
 
 void MachOFileLayout::writeFunctionStartsInfo() {
+  if (!_functionStartsSize)
+    return;
   memcpy(&_buffer[_startOfFunctionStarts], _file.functionStarts.data(),
          _functionStartsSize);
 }