# # define YYFLAG -1000 # define YYERROR goto yyerrlab # define YYACCEPT return(0) # define YYABORT return(1) /* parser for yacc output */ int yydebug 0; /* 1 for debugging */ YYSTYPE yyv[YYMAXDEPTH]; /* where the values are stored */ int yychar -1; /* current input token number */ int yynerrs 0; /* number of errors */ int yyerrflag 0; /* error recovery flag */ yyparse() { int yys[YYMAXDEPTH]; int yyj, yym; register YYSTYPE *yypvt; register yystate, *yyps, yyn; register YYSTYPE *yypv; register *yyxi; yystate = 0; yychar = -1; yynerrs = 0; yyerrflag = 0; yyps= &yys[-1]; yypv= &yyv[-1]; yystack: /* put a state and value onto the stack */ if( yydebug ) printf( "state %d, value %d, char %d\n",yystate,yyval,yychar ); if( ++yyps> &yys[YYMAXDEPTH] ) yyerror( "yacc stack overflow" ); *yyps = yystate; ++yypv; YYVCOPY(*yypv,yyval); yynewstate: yyn = yypact[yystate]; if( yyn<= YYFLAG ) goto yydefault; /* simple state */ if( yychar<0 ) if( (yychar=yylex())<0 ) yychar=0; if( (yyn =+ yychar)<0 || yyn >= yylast ) goto yydefault; if( yychk[ yyn=yyact[ yyn ] ] == yychar ){ /* valid shift */ yychar = -1; YYVCOPY(yyval,yylval); yystate = yyn; if( yyerrflag > 0 ) --yyerrflag; goto yystack; } yydefault: /* default state action */ if( (yyn=yydef[yystate]) == -2 ) { if( yychar<0 ) if( (yychar=yylex())<0 ) yychar = 0; /* look through exception table */ for( yyxi=yyexca; (*yyxi!= (-1)) || (yyxi[1]!=yystate) ; yyxi =+ 2 ) ; /* VOID */ while( *(yyxi=+2) >= 0 ){ if( *yyxi == yychar ) break; } if( (yyn = yyxi[1]) < 0 ) return(0); /* accept */ } if( yyn == 0 ){ /* error */ /* error ... attempt to resume parsing */ switch( yyerrflag ){ case 0: /* brand new error */ yyerror( "syntax error" ); yyerrlab: ++yynerrs; case 1: case 2: /* incompletely recovered error ... try again */ yyerrflag = 3; /* find a state where "error" is a legal shift action */ while ( yyps >= yys ) { yyn = yypact[*yyps] + YYERRCODE; if( yyn>= 0 && yyn < yylast && yychk[yyact[yyn]] == YYERRCODE ){ yystate = yyact[yyn]; /* simulate a shift of "error" */ goto yystack; } yyn = yypact[*yyps]; /* the current yyps has no shift onn "error", pop stack */ if( yydebug ) printf( "error recovery pops state %d, uncovers %d\n", *yyps, yyps[-1] ); --yyps; --yypv; } /* there is no state on the stack with an error shift ... abort */ yyabort: return(1); case 3: /* no shift yet; clobber input char */ if( yydebug ) printf( "error recovery discards char %d\n", yychar ); if( yychar == 0 ) goto yyabort; /* don't discard EOF, quit */ yychar = -1; goto yynewstate; /* try again in the same state */ } } /* reduction by production yyn */ if( yydebug ) printf("reduce %d\n",yyn); yyps =- yyr2[yyn]; yypvt = yypv; yypv =- yyr2[yyn]; YYVCOPY(yyval,yypv[1]); yym=yyn; /* consult goto table to find next state */ yyn = yyr1[yyn]; yyj = yypgo[yyn] + *yyps + 1; if( yyj>=yylast || yychk[ yystate = yyact[yyj] ] != -yyn ) yystate = yyact[yypgo[yyn]]; switch(yym){ $A } goto yystack; /* stack new state and value */ }