1 files changed, 39 insertions, 0 deletions
diff --git a/llvm/lib/TableGen/Parser.cpp b/llvm/lib/TableGen/Parser.cpp
new file mode 100644
index 000000000000..818ded19432b
--- /dev/null
+++ b/llvm/lib/TableGen/Parser.cpp
@@ -0,0 +1,39 @@
+//===- Parser.cpp - Top-Level TableGen Parser implementation --------------===//
+//
+// 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
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/TableGen/Parser.h"
+#include "TGParser.h"
+#include "llvm/Support/MemoryBuffer.h"
+#include "llvm/TableGen/Record.h"
+
+using namespace llvm;
+
+bool llvm::TableGenParseFile(SourceMgr &InputSrcMgr, RecordKeeper &Records) {
+  // Initialize the global TableGen source manager by temporarily taking control
+  // of the input buffer in `SrcMgr`. This is kind of a hack, but allows for
+  // preserving TableGen's current awkward diagnostic behavior. If we can remove
+  // this reliance, we could drop all of this.
+  SrcMgr = SourceMgr();
+  SrcMgr.takeSourceBuffersFrom(InputSrcMgr);
+  SrcMgr.setIncludeDirs(InputSrcMgr.getIncludeDirs());
+  SrcMgr.setDiagHandler(InputSrcMgr.getDiagHandler(),
+                        InputSrcMgr.getDiagContext());
+
+  // Setup the record keeper and try to parse the file.
+  auto *MainFileBuffer = SrcMgr.getMemoryBuffer(SrcMgr.getMainFileID());
+  Records.saveInputFilename(MainFileBuffer->getBufferIdentifier().str());
+
+  TGParser Parser(SrcMgr, /*Macros=*/None, Records);
+  bool ParseResult = Parser.ParseFile();
+
+  // After parsing, reclaim the source manager buffers from TableGen's global
+  // manager.
+  InputSrcMgr.takeSourceBuffersFrom(SrcMgr);
+  SrcMgr = SourceMgr();
+  return ParseResult;
+}