Eliminate a race condition with the global module index.

Essentially, a module file on disk could change size between the time
we stat() it and the time we open it, and we need to be robust against
such a problem.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@174529 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 2 insertions, 1 deletions

diff --git a/lib/Serialization/GlobalModuleIndex.cpp b/lib/Serialization/GlobalModuleIndex.cpp
index 72165bcfc5..5b2ab913fa 100644
--- a/lib/Serialization/GlobalModuleIndex.cpp
+++ b/lib/Serialization/GlobalModuleIndex.cpp
@@ -536,7 +536,8 @@ namespace {
 bool GlobalModuleIndexBuilder::loadModuleFile(const FileEntry *File) {
   // Open the module file.
   OwningPtr<llvm::MemoryBuffer> Buffer;
-  Buffer.reset(FileMgr.getBufferForFile(File));
+  std::string ErrorStr;
+  Buffer.reset(FileMgr.getBufferForFile(File, &ErrorStr, /*isVolatile=*/true));
   if (!Buffer) {
     return true;
   }