commit 8e1b9a17a692d428eeb16c0189ccbbaa741b366d
author Pete Cooper <peter_cooper@apple.com> Tue Mar 22 22:51:03 2016 +0000
committer Pete Cooper <peter_cooper@apple.com> Tue Mar 22 22:51:03 2016 +0000
tree 4b2734e00834943e30876d304e9426ec15e3f076
parent cd46960e6b93f07995e378534690c8ce3245fd53

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

llvm-svn: 264114

lld/lib/ReaderWriter/MachO/MachONormalizedFileBinaryWriter.cpp

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::writeFunctionStartsInfo() {
+  if (!_functionStartsSize)
+    return;
   memcpy(&_buffer[_startOfFunctionStarts], _file.functionStarts.data(),
          _functionStartsSize);
 }