DLexer.cpp

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/* DLexer.c
 *
 * SOFTWARE RIGHTS
 *
 * We reserve no LEGAL rights to the Purdue Compiler Construction Tool
 * Set (PCCTS) -- PCCTS is in the public domain.  An individual or
 * company may do whatever they wish with source code distributed with
 * PCCTS or the code generated by PCCTS, including the incorporation of
 * PCCTS, or its output, into commerical software.
 *
 * We encourage users to develop software with PCCTS.  However, we do ask
 * that credit is given to us for developing PCCTS.  By "credit",
 * we mean that if you incorporate our source code into one of your
 * programs (commercial product, research project, or otherwise) that you
 * acknowledge this fact somewhere in the documentation, research report,
 * etc...  If you like PCCTS and have developed a nice tool with the
 * output, please mention that you developed it using PCCTS.  In
 * addition, we ask that this header remain intact in our source code.
 * As long as these guidelines are kept, we expect to continue enhancing
 * this system and expect to make other tools available as they are
 * completed.
 *
 * ANTLR 1.33
 * Terence Parr
 * Parr Research Corporation
 * with Purdue University and AHPCRC, University of Minnesota
 * 1989-1998
 */

#define ZZINC {if ( track_columns ) (++_endcol);}

#define ZZGETC {ch = input->nextChar(); cl = ZZSHIFT(ch);}

#define ZZNEWSTATE      (newstate = dfa[state][cl])

#ifndef ZZCOPY
#define ZZCOPY  \
        /* Truncate matching buffer to size (not an error) */   \
        if (nextpos < lastpos){                         \
                *(nextpos++) = ch;                      \
        }else{                                                  \
                bufovf = 1;                                     \
        }
#endif

void DLGLexer::
mode( int m )
{
        /* points to base of dfa table */
        if (m<MAX_MODE){
                automaton = m;
                /* have to redo class since using different compression */
                cl = ZZSHIFT(ch);
        }else{
                sprintf((char *)ebuf,"Invalid automaton mode = %d ",m);
                errstd(ebuf);
        }
}

ANTLRTokenType DLGLexer::
nextTokenType(void)
{
        register int state, newstate;
        /* last space reserved for the null char */
        register DLGChar *lastpos;
        ANTLRTokenType tk;

skip:
        bufovf = 0;
        lastpos = &_lextext[_bufsize-1];
        nextpos = _lextext;
        _begcol = _endcol+1;
more:
        _begexpr = nextpos;
        if ( interactive ) {
                /* interactive version of automaton */
                /* if there is something in ch, process it */
                state = newstate = dfa_base[automaton];
                if (charfull){
                        ZZINC;
                        ZZCOPY;
                        ZZNEWSTATE;
                }
                while (alternatives[newstate]){
                        state = newstate;
                        ZZGETC;
                        ZZINC;
                        ZZCOPY;
                        ZZNEWSTATE;
                }
                /* figure out if last character really part of token */
                if ((state != dfa_base[automaton]) && (newstate == DfaStates)){
                        charfull = 1;
                        --nextpos;
                }else{
                        charfull = 0;
                        state = newstate;
                }
                *(nextpos) = '\0';
                /* Able to transition out of start state to some non err state?*/
                if ( state == dfa_base[automaton] ){
                        /* make sure doesn't get stuck */
                        advance();
                }
        }
        else { /* non-interactive version of automaton */
                if (!charfull)
                        advance();
                else
                        ZZINC;
                state = dfa_base[automaton];
                while (ZZNEWSTATE != DfaStates) {
                        state = newstate;
                        ZZCOPY;
                        ZZGETC;
                        ZZINC;
                }
                charfull = 1;
                if ( state == dfa_base[automaton] ){
                        if (nextpos < lastpos){
                                *(nextpos++) = ch;
                        }else{
                                bufovf = 1;
                        }
                        *nextpos = '\0';
                        /* make sure doesn't get stuck */
                        advance();
                }else{
                        *nextpos = '\0';
                }
        }
        if ( track_columns ) _endcol -= charfull;
        _endexpr = nextpos -1;
        add_erase = 0;
#ifdef OLD
        tk = (ANTLRTokenType)
                 (*actions[accepts[state]])(this);      // must pass this manually
                                                                                        // actions is not a [] of pointers
                                                                                        // to member functions.
#endif
        tk = (this->*actions[accepts[state]])();

// MR1
// MR1 11-Apr-97  Help for tracking DLG results
// MR1

#ifdef DEBUG_LEXER

/* MR1 */        if (debugLexerFlag) {
/* MR1 */          if (parser != NULL) {
/* MR1 */            printf("\ntoken name=%s",parser->parserTokenName(tk));
/* MR1 */          } else {
/* MR1 */            printf("\ntoken nnumber=%d",tk);
/* MR1 */          };
/* MR1 */          printf(" lextext=(%s) mode=%d",
/* MR1 */                (_lextext[0]=='\n' && _lextext[1]==0) ?
/* MR1 */                       "newline" : _lextext,
/* MR1 */                               automaton);
/* MR1 */          if (interactive && !charfull) {
/* MR1 */            printf(" char=empty");
/* MR1 */          } else {
/* MR1 */            if (ch=='\n') {
/* MR1 */              printf(" char=newline");
/* MR1 */            } else {
/* MR1 */              printf(" char=(%c)",ch);
/* MR1 */            };
/* MR1 */          };
/* MR1 */          printf(" %s\n",
/* MR1 */                (add_erase==1 ? "skip()" :
/* MR1 */                 add_erase==2 ? "more()" :
/* MR1 */                 ""));
/* MR1 */        };

#endif

        switch (add_erase) {
                case 1: goto skip;
                case 2: goto more;
        }
        return tk;
}

void DLGLexer::
advance()
{
        if ( input==NULL ) err_in();
        ZZGETC; charfull = 1; ZZINC;
}