[llvm] [CGData] llvm-cgdata (PR #89884)

[Kyungwoo Lee via llvm-commits]

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@@ -0,0 +1,174 @@
+//===- CodeGenDataReader.cpp ----------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains support for reading codegen data.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/CodeGenData/CodeGenDataReader.h"
+#include "llvm/CodeGenData/OutlinedHashTreeRecord.h"
+#include "llvm/Support/MemoryBuffer.h"
+
+#define DEBUG_TYPE "cg-data-reader"
+
+using namespace llvm;
+
+namespace llvm {
+
+static Expected<std::unique_ptr<MemoryBuffer>>
+setupMemoryBuffer(const Twine &Filename, vfs::FileSystem &FS) {
+  auto BufferOrErr = Filename.str() == "-" ? MemoryBuffer::getSTDIN()
+                                           : FS.getBufferForFile(Filename);
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kyulee-com wrote:

Similar to the IRPGO case https://github.com/llvm/llvm-project/blob/main/llvm/lib/ProfileData/InstrProfReader.cpp#L73-L74, I want to keep `FS` in case a custom file system is needed.

https://github.com/llvm/llvm-project/pull/89884