Fix undefined behaviour reported by the new --enable-expensive-checks option.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@37829 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp
index 0e857021a486915304e68ddde5a22de6ac5ad6f7..43eb1813ad6c06575f7dd76590d627e3f665792c 100644 (file)
--- a/lib/Support/MemoryBuffer.cpp
+++ b/lib/Support/MemoryBuffer.cpp
@@ -251,8 +251,9 @@ MemoryBuffer *MemoryBuffer::getSTDIN() {
   while (size_t ReadBytes = fread(Buffer, 1, 4096*4, stdin))
     FileData.insert(FileData.end(), Buffer, Buffer+ReadBytes);
   
+  FileData.push_back(0); // &FileData[Size] is invalid. So is &*FileData.end().
   size_t Size = FileData.size();
   MemoryBuffer *B = new STDINBufferFile();
-  B->initCopyOf(&FileData[0], &FileData[Size]);
+  B->initCopyOf(&FileData[0], &FileData[Size-1]);
   return B;
 }