[sourcekitd-test] Don't cache memory buffers

If we cache the buffers between multiple requests we don’t pick up if the source file has changed on disk since we last read it.

Author: ahoppen

tools/SourceKit/tools/sourcekitd-test/sourcekitd-test.cpp

@@ -2655,8 +2655,6 @@ static unsigned resolveFromLineCol(unsigned Line, unsigned Col,
   exit(1);
 }
 
-static llvm::StringMap<llvm::MemoryBuffer*> Buffers;
-
 /// Opens \p Filename, first checking \p VFSFiles and then falling back to the
 /// filesystem otherwise. If the file could not be opened and \p ExitOnError is
 /// true, the process exits with an error message. Otherwise a buffer
@@ -2669,10 +2667,6 @@ getBufferForFilename(StringRef Filename,
   auto MappedFilename =
       VFSFileIt == VFSFiles.end() ? Filename : StringRef(VFSFileIt->second.path);
 
-  auto It = Buffers.find(MappedFilename);
-  if (It != Buffers.end())
-    return It->second;
-
   auto FileBufOrErr = llvm::MemoryBuffer::getFile(MappedFilename);
   std::unique_ptr<llvm::MemoryBuffer> Buffer;
   if (!FileBufOrErr) {
@@ -2687,5 +2681,5 @@ getBufferForFilename(StringRef Filename,
     Buffer = std::move(FileBufOrErr.get());
   }
 
-  return Buffers[MappedFilename] = Buffer.release();
+  return Buffer.release();
 }