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

1 files changed, 125 insertions, 0 deletions

diff --git a/lib/TableGen/TGLexer.h b/lib/TableGen/TGLexer.h
new file mode 100644
index 00000000000..84d328b12d9
--- /dev/null
+++ b/lib/TableGen/TGLexer.h
@@ -0,0 +1,125 @@
+//===- TGLexer.h - Lexer for TableGen Files ---------------------*- C++ -*-===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This class represents the Lexer for tablegen files.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef TGLEXER_H
+#define TGLEXER_H
+
+#include "llvm/Support/DataTypes.h"
+#include <string>
+#include <vector>
+#include <cassert>
+
+namespace llvm {
+class MemoryBuffer;
+class SourceMgr;
+class SMLoc;
+class Twine;
+
+namespace tgtok {
+  enum TokKind {
+    // Markers
+    Eof, Error,
+    
+    // Tokens with no info.
+    minus, plus,        // - +
+    l_square, r_square, // [ ]
+    l_brace, r_brace,   // { }
+    l_paren, r_paren,   // ( )
+    less, greater,      // < >
+    colon, semi,        // : ;
+    comma, period,      // , .
+    equal, question,    // = ?
+    
+    // Keywords.
+    Bit, Bits, Class, Code, Dag, Def, Defm, Field, In, Int, Let, List,
+    MultiClass, String,
+    
+    // !keywords.
+    XConcat, XSRA, XSRL, XSHL, XStrConcat, XCast, XSubst,
+    XForEach, XHead, XTail, XEmpty, XIf, XEq,
+
+    // Integer value.
+    IntVal,
+    
+    // String valued tokens.
+    Id, StrVal, VarName, CodeFragment
+  };
+}
+
+/// TGLexer - TableGen Lexer class.
+class TGLexer {
+  SourceMgr &SrcMgr;
+  
+  const char *CurPtr;
+  const MemoryBuffer *CurBuf;
+
+  // Information about the current token.
+  const char *TokStart;
+  tgtok::TokKind CurCode;
+  std::string CurStrVal;  // This is valid for ID, STRVAL, VARNAME, CODEFRAGMENT
+  int64_t CurIntVal;      // This is valid for INTVAL.
+
+  /// CurBuffer - This is the current buffer index we're lexing from as managed
+  /// by the SourceMgr object.
+  int CurBuffer;
+  /// Dependencies - This is the list of all included files.
+  std::vector<std::string> Dependencies;
+  
+public:
+  TGLexer(SourceMgr &SrcMgr);
+  ~TGLexer() {}
+  
+  tgtok::TokKind Lex() {
+    return CurCode = LexToken();
+  }
+
+  const std::vector<std::string> &getDependencies() const {
+    return Dependencies;
+  }
+  
+  tgtok::TokKind getCode() const { return CurCode; }
+
+  const std::string &getCurStrVal() const {
+    assert((CurCode == tgtok::Id || CurCode == tgtok::StrVal || 
+            CurCode == tgtok::VarName || CurCode == tgtok::CodeFragment) &&
+           "This token doesn't have a string value");
+    return CurStrVal;
+  }
+  int64_t getCurIntVal() const {
+    assert(CurCode == tgtok::IntVal && "This token isn't an integer");
+    return CurIntVal;
+  }
+
+  SMLoc getLoc() const;
+  
+private:
+  /// LexToken - Read the next token and return its code.
+  tgtok::TokKind LexToken();
+  
+  tgtok::TokKind ReturnError(const char *Loc, const Twine &Msg);
+  
+  int getNextChar();
+  void SkipBCPLComment();
+  bool SkipCComment();
+  tgtok::TokKind LexIdentifier();
+  bool LexInclude();
+  tgtok::TokKind LexString();
+  tgtok::TokKind LexVarName();
+  tgtok::TokKind LexNumber();
+  tgtok::TokKind LexBracket();
+  tgtok::TokKind LexExclaim();
+};
+  
+} // end namespace llvm
+
+#endif