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

include/llvm/TableGen/Error.h

@@ -0,0 +1,43 @@
+//===- llvm/TableGen/Error.h - tblgen error handling helpers ----*- 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.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_ERROR_H
+#define LLVM_TABLEGEN_ERROR_H
+
+#include "llvm/Support/SourceMgr.h"
+
+namespace llvm {
+
+class TGError {
+  SMLoc Loc;
+  std::string Message;
+public:
+  TGError(SMLoc loc, const std::string &message) : Loc(loc), Message(message) {}
+
+  SMLoc getLoc() const { return Loc; }
+  const std::string &getMessage() const { return Message; }
+};
+
+void PrintError(SMLoc ErrorLoc, const Twine &Msg);
+void PrintError(const char *Loc, const Twine &Msg);
+void PrintError(const Twine &Msg);
+void PrintError(const TGError &Error);
+
+
+extern SourceMgr SrcMgr;
+
+
+} // end namespace "llvm"
+
+#endif

include/llvm/TableGen/Main.h

@@ -0,0 +1,26 @@
+//===- llvm/TableGen/Main.h - tblgen entry point ----------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file declares the common entry point for tblgen tools.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_MAIN_H
+#define LLVM_TABLEGEN_MAIN_H
+
+namespace llvm {
+
+class TableGenAction;
+
+/// Run the table generator, performing the specified Action on parsed records.
+int TableGenMain(char *argv0, TableGenAction &Action);
+
+}
+
+#endif

include/llvm/TableGen/TableGenAction.h

@@ -0,0 +1,34 @@
+//===- llvm/TableGen/TableGenAction.h - defines TableGenAction --*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines the TableGenAction base class to be derived from by
+// tblgen tools.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_TABLEGENACTION_H
+#define LLVM_TABLEGEN_TABLEGENACTION_H
+
+namespace llvm {
+
+class raw_ostream;
+class RecordKeeper;
+
+class TableGenAction {
+public:
+  virtual ~TableGenAction() {}
+
+  /// Perform the action using Records, and write output to OS.
+  /// @returns true on error, false otherwise
+  virtual bool operator()(raw_ostream &OS, RecordKeeper &Records) = 0;
+};
+
+}
+
+#endif

include/llvm/TableGen/TableGenBackend.h

@@ -0,0 +1,43 @@
+//===- llvm/TableGen/TableGenBackend.h - Backend base class -----*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// The TableGenBackend class is provided as a common interface for all TableGen
+// backends.  It provides useful services and an standardized interface.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef LLVM_TABLEGEN_TABLEGENBACKEND_H
+#define LLVM_TABLEGEN_TABLEGENBACKEND_H
+
+#include "llvm/Support/raw_ostream.h"
+#include <string>
+
+namespace llvm {
+
+class Record;
+class RecordKeeper;
+
+struct TableGenBackend {
+  virtual ~TableGenBackend() {}
+
+  // run - All TableGen backends should implement the run method, which should
+  // be the main entry point.
+  virtual void run(raw_ostream &OS) = 0;
+
+
+public:   // Useful helper routines...
+  /// EmitSourceFileHeader - Output a LLVM style file header to the specified
+  /// ostream.
+  void EmitSourceFileHeader(const std::string &Desc, raw_ostream &OS) const;
+
+};
+
+} // End llvm namespace
+
+#endif