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      1 //===- TGLexer.h - Lexer for TableGen Files ---------------------*- C++ -*-===//
      2 //
      3 //                     The LLVM Compiler Infrastructure
      4 //
      5 // This file is distributed under the University of Illinois Open Source
      6 // License. See LICENSE.TXT for details.
      7 //
      8 //===----------------------------------------------------------------------===//
      9 //
     10 // This class represents the Lexer for tablegen files.
     11 //
     12 //===----------------------------------------------------------------------===//
     13 
     14 #ifndef TGLEXER_H
     15 #define TGLEXER_H
     16 
     17 #include "llvm/Support/DataTypes.h"
     18 #include "llvm/Support/SMLoc.h"
     19 #include <cassert>
     20 #include <map>
     21 #include <string>
     22 
     23 namespace llvm {
     24 class MemoryBuffer;
     25 class SourceMgr;
     26 class SMLoc;
     27 class Twine;
     28 
     29 namespace tgtok {
     30   enum TokKind {
     31     // Markers
     32     Eof, Error,
     33 
     34     // Tokens with no info.
     35     minus, plus,        // - +
     36     l_square, r_square, // [ ]
     37     l_brace, r_brace,   // { }
     38     l_paren, r_paren,   // ( )
     39     less, greater,      // < >
     40     colon, semi,        // : ;
     41     comma, period,      // , .
     42     equal, question,    // = ?
     43     paste,              // #
     44 
     45     // Keywords.
     46     Bit, Bits, Class, Code, Dag, Def, Foreach, Defm, Field, In, Int, Let, List,
     47     MultiClass, String,
     48 
     49     // !keywords.
     50     XConcat, XADD, XSRA, XSRL, XSHL, XStrConcat, XCast, XSubst,
     51     XForEach, XHead, XTail, XEmpty, XIf, XEq,
     52 
     53     // Integer value.
     54     IntVal,
     55 
     56     // String valued tokens.
     57     Id, StrVal, VarName, CodeFragment
     58   };
     59 }
     60 
     61 /// TGLexer - TableGen Lexer class.
     62 class TGLexer {
     63   SourceMgr &SrcMgr;
     64 
     65   const char *CurPtr;
     66   const MemoryBuffer *CurBuf;
     67 
     68   // Information about the current token.
     69   const char *TokStart;
     70   tgtok::TokKind CurCode;
     71   std::string CurStrVal;  // This is valid for ID, STRVAL, VARNAME, CODEFRAGMENT
     72   int64_t CurIntVal;      // This is valid for INTVAL.
     73 
     74   /// CurBuffer - This is the current buffer index we're lexing from as managed
     75   /// by the SourceMgr object.
     76   int CurBuffer;
     77 
     78 public:
     79   typedef std::map<std::string, SMLoc> DependenciesMapTy;
     80 private:
     81   /// Dependencies - This is the list of all included files.
     82   DependenciesMapTy Dependencies;
     83 
     84 public:
     85   TGLexer(SourceMgr &SrcMgr);
     86   ~TGLexer() {}
     87 
     88   tgtok::TokKind Lex() {
     89     return CurCode = LexToken();
     90   }
     91 
     92   const DependenciesMapTy &getDependencies() const {
     93     return Dependencies;
     94   }
     95 
     96   tgtok::TokKind getCode() const { return CurCode; }
     97 
     98   const std::string &getCurStrVal() const {
     99     assert((CurCode == tgtok::Id || CurCode == tgtok::StrVal ||
    100             CurCode == tgtok::VarName || CurCode == tgtok::CodeFragment) &&
    101            "This token doesn't have a string value");
    102     return CurStrVal;
    103   }
    104   int64_t getCurIntVal() const {
    105     assert(CurCode == tgtok::IntVal && "This token isn't an integer");
    106     return CurIntVal;
    107   }
    108 
    109   SMLoc getLoc() const;
    110 
    111 private:
    112   /// LexToken - Read the next token and return its code.
    113   tgtok::TokKind LexToken();
    114 
    115   tgtok::TokKind ReturnError(const char *Loc, const Twine &Msg);
    116 
    117   int getNextChar();
    118   int peekNextChar(int Index);
    119   void SkipBCPLComment();
    120   bool SkipCComment();
    121   tgtok::TokKind LexIdentifier();
    122   bool LexInclude();
    123   tgtok::TokKind LexString();
    124   tgtok::TokKind LexVarName();
    125   tgtok::TokKind LexNumber();
    126   tgtok::TokKind LexBracket();
    127   tgtok::TokKind LexExclaim();
    128 };
    129 
    130 } // end namespace llvm
    131 
    132 #endif
    133