Move TableGen's parser and entry point into a library

This is the first step towards splitting LLVM and Clang's tblgen executables.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140951 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/TableGen/Error.cpp b/lib/TableGen/Error.cpp
new file mode 100644
index 0000000..5b2cbbf
--- /dev/null
+++ b/lib/TableGen/Error.cpp
@@ -0,0 +1,39 @@
+//===- Error.cpp - tblgen error handling helper routines --------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains error handling helper routines to pretty-print diagnostic
+// messages from tblgen.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/TableGen/Error.h"
+#include "llvm/ADT/Twine.h"
+#include "llvm/Support/raw_ostream.h"
+
+namespace llvm {
+
+SourceMgr SrcMgr;
+
+void PrintError(SMLoc ErrorLoc, const Twine &Msg) {
+  SrcMgr.PrintMessage(ErrorLoc, Msg, "error");
+}
+
+void PrintError(const char *Loc, const Twine &Msg) {
+  SrcMgr.PrintMessage(SMLoc::getFromPointer(Loc), Msg, "error");
+}
+
+void PrintError(const Twine &Msg) {
+  errs() << "error:" << Msg << "\n";
+}
+
+void PrintError(const TGError &Error) {
+  PrintError(Error.getLoc(), Error.getMessage());
+}
+
+} // end namespace llvm