Added forgotten noexcept.

[oota-llvm.git] / lib / Support / MemoryBuffer.cpp

diff --git a/lib/Support/MemoryBuffer.cpp b/lib/Support/MemoryBuffer.cpp
index 5f4b7daae53d162affc9dd71d9cccaba140b4312..9506da77704aa5cae39ab25b41a4abc03f094829 100644 (file)
--- a/lib/Support/MemoryBuffer.cpp
+++ b/lib/Support/MemoryBuffer.cpp
@@ -141,10 +141,9 @@ MemoryBuffer *MemoryBuffer::getNewUninitMemBuffer(size_t Size,
   return new (Mem) MemoryBufferMem(StringRef(Buf, Size), true);
 }
 
-/// getNewMemBuffer - Allocate a new MemoryBuffer of the specified size that
-/// is completely initialized to zeros.  Note that the caller should
-/// initialize the memory allocated by this method.  The memory is owned by
-/// the MemoryBuffer object.
+/// getNewMemBuffer - Allocate a new zero-initialized MemoryBuffer of the
+/// specified size. Note that the caller need not initialize the memory
+/// allocated by this method.  The memory is owned by the MemoryBuffer object.
 MemoryBuffer *MemoryBuffer::getNewMemBuffer(size_t Size, StringRef BufferName) {
   MemoryBuffer *SB = getNewUninitMemBuffer(Size, BufferName);
   if (!SB) return nullptr;
@@ -305,6 +304,14 @@ static bool shouldUseMmap(int FD,
   if ((FileSize & (PageSize -1)) == 0)
     return false;
 
+#if defined(__CYGWIN__)
+  // Don't try to map files that are exactly a multiple of the physical page size
+  // if we need a null terminator.
+  // FIXME: We should reorganize again getPageSize() on Win32.
+  if ((FileSize & (4096 - 1)) == 0)
+    return false;
+#endif
+
   return true;
 }