parser.cc

a little DFA compiler.

  /* Shift the look-ahead token.  */
  YY_SYMBOL_PRINT ("Shifting", yytoken, &yylval, &yylloc);

  /* Discard the shifted token unless it is eof.  */
  if (yychar != YYEOF)
    yychar = YYEMPTY;

  yystate = yyn;
  *++yyvsp = yylval;

  goto yynewstate;


/*-----------------------------------------------------------.
| yydefault -- do the default action for the current state.  |
`-----------------------------------------------------------*/
yydefault:
  yyn = yydefact[yystate];
  if (yyn == 0)
    goto yyerrlab;
  goto yyreduce;


/*-----------------------------.
| yyreduce -- Do a reduction.  |
`-----------------------------*/
yyreduce:
  /* yyn is the number of a rule to reduce with.  */
  yylen = yyr2[yyn];

  /* If YYLEN is nonzero, implement the default value of the action:
     `$$ = $1'.

     Otherwise, the following line sets YYVAL to garbage.
     This behavior is undocumented and Bison
     users should not rely upon it.  Assigning to YYVAL
     unconditionally makes the parser a bit smaller, and it avoids a
     GCC warning that YYVAL may be used uninitialized.  */
  yyval = yyvsp[1-yylen];


  YY_REDUCE_PRINT (yyn);
  switch (yyn)
    {
        case 2:
#line 84 "./parser.y"
    { accept = 0;
		  spec = NULL; }
    break;

  case 3:
#line 87 "./parser.y"
    { spec = spec? mkAlt(spec, (yyvsp[(2) - (2)].regexp)) : (yyvsp[(2) - (2)].regexp); }
    break;

  case 5:
#line 92 "./parser.y"
    { if((yyvsp[(1) - (4)].symbol)->re)
		      in->fatal("sym already defined");
		  (yyvsp[(1) - (4)].symbol)->re = (yyvsp[(3) - (4)].regexp); }
    break;

  case 6:
#line 96 "./parser.y"
    { in->fatal("trailing contexts are not allowed in named definitions"); }
    break;

  case 7:
#line 98 "./parser.y"
    { in->config(*(yyvsp[(1) - (4)].str), *(yyvsp[(3) - (4)].str)); delete (yyvsp[(1) - (4)].str); delete (yyvsp[(3) - (4)].str); }
    break;

  case 8:
#line 100 "./parser.y"
    { in->config(*(yyvsp[(1) - (4)].str), (yyvsp[(3) - (4)].number)); delete (yyvsp[(1) - (4)].str); }
    break;

  case 9:
#line 104 "./parser.y"
    { (yyval.regexp) = new RuleOp((yyvsp[(1) - (3)].regexp), (yyvsp[(2) - (3)].regexp), (yyvsp[(3) - (3)].token), accept++); }
    break;

  case 10:
#line 108 "./parser.y"
    { (yyval.regexp) = new NullOp; }
    break;

  case 11:
#line 110 "./parser.y"
    { (yyval.regexp) = (yyvsp[(2) - (2)].regexp); }
    break;

  case 12:
#line 114 "./parser.y"
    { (yyval.regexp) = (yyvsp[(1) - (1)].regexp); }
    break;

  case 13:
#line 116 "./parser.y"
    { (yyval.regexp) =  mkAlt((yyvsp[(1) - (3)].regexp), (yyvsp[(3) - (3)].regexp)); }
    break;

  case 14:
#line 120 "./parser.y"
    { (yyval.regexp) = (yyvsp[(1) - (1)].regexp); }
    break;

  case 15:
#line 122 "./parser.y"
    { (yyval.regexp) =  mkDiff((yyvsp[(1) - (3)].regexp), (yyvsp[(3) - (3)].regexp));
		  if(!(yyval.regexp))
		       in->fatal("can only difference char sets");
		}
    break;

  case 16:
#line 129 "./parser.y"
    { (yyval.regexp) = (yyvsp[(1) - (1)].regexp); }
    break;

  case 17:
#line 131 "./parser.y"
    { (yyval.regexp) = new CatOp((yyvsp[(1) - (2)].regexp), (yyvsp[(2) - (2)].regexp)); }
    break;

  case 18:
#line 135 "./parser.y"
    { (yyval.regexp) = (yyvsp[(1) - (1)].regexp); }
    break;

  case 19:
#line 137 "./parser.y"
    {
		    switch((yyvsp[(2) - (2)].op)){
		    case '*':
			(yyval.regexp) = mkAlt(new CloseOp((yyvsp[(1) - (2)].regexp)), new NullOp());
			break;
		    case '+':
			(yyval.regexp) = new CloseOp((yyvsp[(1) - (2)].regexp));
			break;
		    case '?':
			(yyval.regexp) = mkAlt((yyvsp[(1) - (2)].regexp), new NullOp());
			break;
		    }
		}
    break;

  case 20:
#line 151 "./parser.y"
    {
			(yyval.regexp) = new CloseVOp((yyvsp[(1) - (2)].regexp), (yyvsp[(2) - (2)].extop).minsize, (yyvsp[(2) - (2)].extop).maxsize);
		}
    break;

  case 21:
#line 157 "./parser.y"
    { (yyval.op) = (yyvsp[(1) - (1)].op); }
    break;

  case 22:
#line 159 "./parser.y"
    { (yyval.op) = ((yyvsp[(1) - (2)].op) == (yyvsp[(2) - (2)].op)) ? (yyvsp[(1) - (2)].op) : '*'; }
    break;

  case 23:
#line 163 "./parser.y"
    { if(!(yyvsp[(1) - (1)].symbol)->re)
		      in->fatal("can't find symbol");
		  (yyval.regexp) = (yyvsp[(1) - (1)].symbol)->re; }
    break;

  case 24:
#line 167 "./parser.y"
    { (yyval.regexp) = (yyvsp[(1) - (1)].regexp); }
    break;

  case 25:
#line 169 "./parser.y"
    { (yyval.regexp) = (yyvsp[(1) - (1)].regexp); }
    break;

  case 26:
#line 171 "./parser.y"
    { (yyval.regexp) = (yyvsp[(2) - (3)].regexp); }
    break;


/* Line 1267 of yacc.c.  */
#line 1553 "parser.cc"
      default: break;
    }
  YY_SYMBOL_PRINT ("-> $$ =", yyr1[yyn], &yyval, &yyloc);

  YYPOPSTACK (yylen);
  yylen = 0;
  YY_STACK_PRINT (yyss, yyssp);

  *++yyvsp = yyval;


  /* Now `shift' the result of the reduction.  Determine what state
     that goes to, based on the state we popped back to and the rule
     number reduced by.  */

  yyn = yyr1[yyn];

  yystate = yypgoto[yyn - YYNTOKENS] + *yyssp;
  if (0 <= yystate && yystate <= YYLAST && yycheck[yystate] == *yyssp)
    yystate = yytable[yystate];
  else
    yystate = yydefgoto[yyn - YYNTOKENS];

  goto yynewstate;


/*------------------------------------.
| yyerrlab -- here on detecting error |
`------------------------------------*/
yyerrlab:
  /* If not already recovering from an error, report this error.  */
  if (!yyerrstatus)
    {
      ++yynerrs;
#if ! YYERROR_VERBOSE
      yyerror (YY_("syntax error"));
#else
      {
	YYSIZE_T yysize = yysyntax_error (0, yystate, yychar);
	if (yymsg_alloc < yysize && yymsg_alloc < YYSTACK_ALLOC_MAXIMUM)
	  {
	    YYSIZE_T yyalloc = 2 * yysize;
	    if (! (yysize <= yyalloc && yyalloc <= YYSTACK_ALLOC_MAXIMUM))
	      yyalloc = YYSTACK_ALLOC_MAXIMUM;
	    if (yymsg != yymsgbuf)
	      YYSTACK_FREE (yymsg);
	    yymsg = (char *) YYSTACK_ALLOC (yyalloc);
	    if (yymsg)
	      yymsg_alloc = yyalloc;
	    else
	      {
		yymsg = yymsgbuf;
		yymsg_alloc = sizeof yymsgbuf;
	      }
	  }

	if (0 < yysize && yysize <= yymsg_alloc)
	  {
	    (void) yysyntax_error (yymsg, yystate, yychar);
	    yyerror (yymsg);
	  }
	else
	  {
	    yyerror (YY_("syntax error"));
	    if (yysize != 0)
	      goto yyexhaustedlab;
	  }
      }
#endif
    }



  if (yyerrstatus == 3)
    {
      /* If just tried and failed to reuse look-ahead token after an
	 error, discard it.  */

      if (yychar <= YYEOF)
	{
	  /* Return failure if at end of input.  */
	  if (yychar == YYEOF)
	    YYABORT;
	}
      else
	{
	  yydestruct ("Error: discarding",
		      yytoken, &yylval);
	  yychar = YYEMPTY;
	}
    }

  /* Else will try to reuse look-ahead token after shifting the error
     token.  */
  goto yyerrlab1;


/*---------------------------------------------------.
| yyerrorlab -- error raised explicitly by YYERROR.  |
`---------------------------------------------------*/
yyerrorlab:

  /* Pacify compilers like GCC when the user code never invokes
     YYERROR and the label yyerrorlab therefore never appears in user
     code.  */
  if (/*CONSTCOND*/ 0)
     goto yyerrorlab;

  /* Do not reclaim the symbols of the rule which action triggered
     this YYERROR.  */
  YYPOPSTACK (yylen);
  yylen = 0;
  YY_STACK_PRINT (yyss, yyssp);
  yystate = *yyssp;
  goto yyerrlab1;


/*-------------------------------------------------------------.
| yyerrlab1 -- common code for both syntax error and YYERROR.  |
`-------------------------------------------------------------*/
yyerrlab1:
  yyerrstatus = 3;	/* Each real token shifted decrements this.  */

  for (;;)
    {
      yyn = yypact[yystate];
      if (yyn != YYPACT_NINF)
	{
	  yyn += YYTERROR;
	  if (0 <= yyn && yyn <= YYLAST && yycheck[yyn] == YYTERROR)
	    {
	      yyn = yytable[yyn];
	      if (0 < yyn)
		break;
	    }
	}

      /* Pop the current state because it cannot handle the error token.  */
      if (yyssp == yyss)
	YYABORT;


      yydestruct ("Error: popping",
		  yystos[yystate], yyvsp);
      YYPOPSTACK (1);
      yystate = *yyssp;
      YY_STACK_PRINT (yyss, yyssp);
    }

  if (yyn == YYFINAL)
    YYACCEPT;

  *++yyvsp = yylval;


  /* Shift the error token.  */
  YY_SYMBOL_PRINT ("Shifting", yystos[yyn], yyvsp, yylsp);

  yystate = yyn;
  goto yynewstate;


/*-------------------------------------.
| yyacceptlab -- YYACCEPT comes here.  |
`-------------------------------------*/
yyacceptlab:
  yyresult = 0;
  goto yyreturn;

/*-----------------------------------.
| yyabortlab -- YYABORT comes here.  |
`-----------------------------------*/
yyabortlab:
  yyresult = 1;
  goto yyreturn;

#ifndef yyoverflow
/*-------------------------------------------------.
| yyexhaustedlab -- memory exhaustion comes here.  |
`-------------------------------------------------*/
yyexhaustedlab:
  yyerror (YY_("memory exhausted"));
  yyresult = 2;
  /* Fall through.  */
#endif

yyreturn:
  if (yychar != YYEOF && yychar != YYEMPTY)
     yydestruct ("Cleanup: discarding lookahead",
		 yytoken, &yylval);
  /* Do not reclaim the symbols of the rule which action triggered
     this YYABORT or YYACCEPT.  */
  YYPOPSTACK (yylen);
  YY_STACK_PRINT (yyss, yyssp);
  while (yyssp != yyss)
    {
      yydestruct ("Cleanup: popping",
		  yystos[*yyssp], yyvsp);
      YYPOPSTACK (1);
    }
#ifndef yyoverflow
  if (yyss != yyssa)
    YYSTACK_FREE (yyss);
#endif
#if YYERROR_VERBOSE
  if (yymsg != yymsgbuf)
    YYSTACK_FREE (yymsg);
#endif
  /* Make sure YYID is used.  */
  return YYID (yyresult);
}


#line 174 "./parser.y"


extern "C" {
void yyerror(const char* s)
{
    in->fatal(s);
}

int yylex(){
    return in ? in->scan() : 0;
}
} // end extern "C"

namespace re2c
{

void parse(Scanner& i, std::ostream& o)
{
	in = &i;

	o << "/* Generated by re2c " PACKAGE_VERSION;
	if (!bNoGenerationDate)
	{
		o << " on ";
		time_t now = time(&now);
		o.write(ctime(&now), 24);
	}
	o << " */\n";
	o << sourceFileInfo;
	
	while(i.echo())
	{
		yyparse();
		if(spec)
		{
			genCode(o, topIndent, spec);
		}
		o << sourceFileInfo;
	}

	RegExp::vFreeList.clear();
	Range::vFreeList.clear();
	Symbol::ClearTable();
	in = NULL;
}

} // end namespace re2c