projects / unix-history / blame
| Commit | Line | Data |
|---|---|---|
| 5e74fd0a KT |
1 | # |
| 2 | # define YYFLAG -1000 | |
| 3 | # define YYERROR goto yyerrlab | |
| 4 | # define YYACCEPT return(0) | |
| 5 | # define YYABORT return(1) | |
| 6 | ||
| 7 | /* parser for yacc output */ | |
| 8 | ||
| 9 | int yydebug = 0; /* 1 for debugging */ | |
| 10 | YYSTYPE yyv[YYMAXDEPTH]; /* where the values are stored */ | |
| 11 | int yychar = -1; /* current input token number */ | |
| 12 | int yynerrs = 0; /* number of errors */ | |
| 13 | short yyerrflag = 0; /* error recovery flag */ | |
| 14 | ||
| 15 | yyparse() { | |
| 16 | ||
| 17 | short yys[YYMAXDEPTH]; | |
| 18 | short yyj, yym; | |
| 19 | register YYSTYPE *yypvt; | |
| 20 | register short yystate, *yyps, yyn; | |
| 21 | register YYSTYPE *yypv; | |
| 22 | register short *yyxi; | |
| 23 | ||
| 24 | yystate = 0; | |
| 25 | yychar = -1; | |
| 26 | yynerrs = 0; | |
| 27 | yyerrflag = 0; | |
| 28 | yyps= &yys[-1]; | |
| 29 | yypv= &yyv[-1]; | |
| 30 | ||
| 31 | yystack: /* put a state and value onto the stack */ | |
| 32 | ||
| 33 | if( yydebug ) printf( "state %d, char 0%o\n", yystate, yychar ); | |
| 34 | if( ++yyps> &yys[YYMAXDEPTH] ) { yyerror( "yacc stack overflow" ); return(1); } | |
| 35 | *yyps = yystate; | |
| 36 | ++yypv; | |
| 37 | *yypv = yyval; | |
| 38 | ||
| 39 | yynewstate: | |
| 40 | ||
| 41 | yyn = yypact[yystate]; | |
| 42 | ||
| 43 | if( yyn<= YYFLAG ) goto yydefault; /* simple state */ | |
| 44 | ||
| 45 | if( yychar<0 ) if( (yychar=yylex())<0 ) yychar=0; | |
| 46 | if( (yyn += yychar)<0 || yyn >= YYLAST ) goto yydefault; | |
| 47 | ||
| 48 | if( yychk[ yyn=yyact[ yyn ] ] == yychar ){ /* valid shift */ | |
| 49 | yychar = -1; | |
| 50 | yyval = yylval; | |
| 51 | yystate = yyn; | |
| 52 | if( yyerrflag > 0 ) --yyerrflag; | |
| 53 | goto yystack; | |
| 54 | } | |
| 55 | ||
| 56 | yydefault: | |
| 57 | /* default state action */ | |
| 58 | ||
| 59 | if( (yyn=yydef[yystate]) == -2 ) { | |
| 60 | if( yychar<0 ) if( (yychar=yylex())<0 ) yychar = 0; | |
| 61 | /* look through exception table */ | |
| 62 | ||
| 63 | for( yyxi=yyexca; (*yyxi!= (-1)) || (yyxi[1]!=yystate) ; yyxi += 2 ) ; /* VOID */ | |
| 64 | ||
| 65 | while( *(yyxi+=2) >= 0 ){ | |
| 66 | if( *yyxi == yychar ) break; | |
| 67 | } | |
| 68 | if( (yyn = yyxi[1]) < 0 ) return(0); /* accept */ | |
| 69 | } | |
| 70 | ||
| 71 | if( yyn == 0 ){ /* error */ | |
| 72 | /* error ... attempt to resume parsing */ | |
| 73 | ||
| 74 | switch( yyerrflag ){ | |
| 75 | ||
| 76 | case 0: /* brand new error */ | |
| 77 | ||
| 78 | yyerror( "syntax error" ); | |
| 79 | yyerrlab: | |
| 80 | ++yynerrs; | |
| 81 | ||
| 82 | case 1: | |
| 83 | case 2: /* incompletely recovered error ... try again */ | |
| 84 | ||
| 85 | yyerrflag = 3; | |
| 86 | ||
| 87 | /* find a state where "error" is a legal shift action */ | |
| 88 | ||
| 89 | while ( yyps >= yys ) { | |
| 90 | yyn = yypact[*yyps] + YYERRCODE; | |
| 91 | if( yyn>= 0 && yyn < YYLAST && yychk[yyact[yyn]] == YYERRCODE ){ | |
| 92 | yystate = yyact[yyn]; /* simulate a shift of "error" */ | |
| 93 | goto yystack; | |
| 94 | } | |
| 95 | yyn = yypact[*yyps]; | |
| 96 | ||
| 97 | /* the current yyps has no shift onn "error", pop stack */ | |
| 98 | ||
| 99 | if( yydebug ) printf( "error recovery pops state %d, uncovers %d\n", *yyps, yyps[-1] ); | |
| 100 | --yyps; | |
| 101 | --yypv; | |
| 102 | } | |
| 103 | ||
| 104 | /* there is no state on the stack with an error shift ... abort */ | |
| 105 | ||
| 106 | yyabort: | |
| 107 | return(1); | |
| 108 | ||
| 109 | ||
| 110 | case 3: /* no shift yet; clobber input char */ | |
| 111 | ||
| 112 | if( yydebug ) printf( "error recovery discards char %d\n", yychar ); | |
| 113 | ||
| 114 | if( yychar == 0 ) goto yyabort; /* don't discard EOF, quit */ | |
| 115 | yychar = -1; | |
| 116 | goto yynewstate; /* try again in the same state */ | |
| 117 | ||
| 118 | } | |
| 119 | ||
| 120 | } | |
| 121 | ||
| 122 | /* reduction by production yyn */ | |
| 123 | ||
| 124 | if( yydebug ) printf("reduce %d\n",yyn); | |
| 125 | yyps -= yyr2[yyn]; | |
| 126 | yypvt = yypv; | |
| 127 | yypv -= yyr2[yyn]; | |
| 128 | yyval = yypv[1]; | |
| 129 | yym=yyn; | |
| 130 | /* consult goto table to find next state */ | |
| 131 | yyn = yyr1[yyn]; | |
| 132 | yyj = yypgo[yyn] + *yyps + 1; | |
| 133 | if( yyj>=YYLAST || yychk[ yystate = yyact[yyj] ] != -yyn ) yystate = yyact[yypgo[yyn]]; | |
| 134 | switch(yym){ | |
| 135 | $A | |
| 136 | } | |
| 137 | goto yystack; /* stack new state and value */ | |
| 138 | ||
| 139 | } |