[llvm] 03f1516 - [MemoryBuffer] Revert unintended MemoryBuffer change from D86996

[Fangrui Song via llvm-commits]

Author: Fangrui Song
Date: 2020-09-15T10:21:05-07:00
New Revision: 03f1516d6075f42dce95bcf9fde3f6fde97abd35

URL: https://github.com/llvm/llvm-project/commit/03f1516d6075f42dce95bcf9fde3f6fde97abd35
DIFF: https://github.com/llvm/llvm-project/commit/03f1516d6075f42dce95bcf9fde3f6fde97abd35.diff

LOG: [MemoryBuffer] Revert unintended MemoryBuffer change from D86996

Fixes SupportsTest MemoryBufferTest.mmapVolatileNoNull

Added: 
    

Modified: 
    llvm/lib/Support/MemoryBuffer.cpp

Removed: 
    


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diff  --git a/llvm/lib/Support/MemoryBuffer.cpp b/llvm/lib/Support/MemoryBuffer.cpp
index e31c8e6b072d..248fb72c4968 100644
--- a/llvm/lib/Support/MemoryBuffer.cpp
+++ b/llvm/lib/Support/MemoryBuffer.cpp
@@ -457,7 +457,8 @@ getOpenFileImpl(sys::fs::file_t FD, const Twine &Filename, uint64_t FileSize,
     MapSize = FileSize;
   }
 
-  if (false) {
+  if (shouldUseMmap(FD, FileSize, MapSize, Offset, RequiresNullTerminator,
+                    PageSize, IsVolatile)) {
     std::error_code EC;
     std::unique_ptr<MB> Result(
         new (NamedBufferAlloc(Filename)) MemoryBufferMMapFile<MB>(