Add a sanity check in MemoryBuffer::getOpenFile() to make sure we don't hang

if the passed in FileSize is inaccurate.

rdar://11034179

llvm-svn: 152662

1 files changed, 5 insertions, 1 deletions

diff --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp
index 4b15587db7a..911a03f8088 100644
--- a/llvm/lib/Support/MemoryBuffer.cpp
+++ b/llvm/lib/Support/MemoryBuffer.cpp
@@ -336,7 +336,11 @@ error_code MemoryBuffer::getOpenFile(int FD, const char *Filename,
       // Error while reading.
       return error_code(errno, posix_category());
     }
-    assert(NumRead != 0 && "fstat reported an invalid file size.");
+    if (NumRead == 0) {
+      assert(0 && "We got inaccurate FileSize value or fstat reported an "
+                   "invalid file size.");
+      break;
+    }
     BytesLeft -= NumRead;
     BufPtr += NumRead;
   }