src/bison.hairy

   1                                                           /* -*- C -*- */
   2 extern int timeclock;
   3
   4
   5 int yyerror;            /*  Yyerror and yycost are set by guards.       */
   6 int yycost;             /*  If yyerror is set to a nonzero value by a   */
   7                         /*  guard, the reduction with which the guard   */
   8                         /*  is associated is not performed, and the     */
   9                         /*  error recovery mechanism is invoked.        */
  10                         /*  Yycost indicates the cost of performing     */
  11                         /*  the reduction given the attributes of the   */
  12                         /*  symbols.                                    */
  13
  14
  15 /*  YYMAXDEPTH indicates the size of the parser's state and value       */
  16 /*  stacks.                                                             */
  17
  18 #ifndef YYMAXDEPTH
  19 #define YYMAXDEPTH      500
  20 #endif
  21
  22 /*  YYMAXRULES must be at least as large as the number of rules that    */
  23 /*  could be placed in the rule queue.  That number could be determined */
  24 /*  from the grammar and the size of the stack, but, as yet, it is not. */
  25
  26 #ifndef YYMAXRULES
  27 #define YYMAXRULES      100
  28 #endif
  29
  30 #ifndef YYMAXBACKUP
  31 #define YYMAXBACKUP     100
  32 #endif
  33
  34
  35 short   yyss[YYMAXDEPTH];       /*  the state stack                     */
  36 YYSTYPE yyvs[YYMAXDEPTH];       /*  the semantic value stack            */
  37 YYLTYPE yyls[YYMAXDEPTH];       /*  the location stack                  */
  38 short   yyrq[YYMAXRULES];       /*  the rule queue                      */
  39 int     yychar;                 /*  the lookahead symbol                */
  40
  41 YYSTYPE yylval;                 /*  the semantic value of the           */
  42                                 /*  lookahead symbol                    */
  43
  44 YYSTYPE yytval;                 /*  the semantic value for the state    */
  45                                 /*  at the top of the state stack.      */
  46
  47 YYSTYPE yyval;                  /*  the variable used to return         */
  48                                 /*  semantic values from the action     */
  49                                 /*  routines                            */
  50
  51 YYLTYPE yylloc;         /*  location data for the lookahead     */
  52                                 /*  symbol                              */
  53
  54 YYLTYPE yytloc;         /*  location data for the state at the  */
  55                                 /*  top of the state stack              */
  56
  57
  58 int     yynunlexed;
  59 short   yyunchar[YYMAXBACKUP];
  60 YYSTYPE yyunval[YYMAXBACKUP];
  61 YYLTYPE yyunloc[YYMAXBACKUP];
  62
  63 short *yygssp;                  /*  a pointer to the top of the state   */
  64                                 /*  stack; only set during error        */
  65                                 /*  recovery.                           */
  66
  67 YYSTYPE *yygvsp;                /*  a pointer to the top of the value   */
  68                                 /*  stack; only set during error        */
  69                                 /*  recovery.                           */
  70
  71 YYLTYPE *yyglsp;                /*  a pointer to the top of the         */
  72                                 /*  location stack; only set during     */
  73                                 /*  error recovery.                     */
  74
  75
  76 /*  Yyget is an interface between the parser and the lexical analyzer.  */
  77 /*  It is costly to provide such an interface, but it avoids requiring  */
  78 /*  the lexical analyzer to be able to back up the scan.                */
  79
  80 yyget()
  81 {
  82   if (yynunlexed > 0)
  83     {
  84       yynunlexed--;
  85       yychar = yyunchar[yynunlexed];
  86       yylval = yyunval[yynunlexed];
  87       yylloc = yyunloc[yynunlexed];
  88     }
  89   else if (yychar <= 0)
  90     yychar = 0;
  91   else
  92     {
  93       yychar = yylex();
  94       if (yychar < 0)
  95         yychar = 0;
  96       else yychar = YYTRANSLATE(yychar);
  97     }
  98 }
  99
 100
 101
 102 yyunlex(chr, val, loc)
 103 int chr;
 104 YYSTYPE val;
 105 YYLTYPE loc;
 106 {
 107   yyunchar[yynunlexed] = chr;
 108   yyunval[yynunlexed] = val;
 109   yyunloc[yynunlexed] = loc;
 110   yynunlexed++;
 111 }
 112
 113
 114
 115 yyrestore(first, last)
 116 register short *first;
 117 register short *last;
 118 {
 119   register short *ssp;
 120   register short *rp;
 121   register int symbol;
 122   register int state;
 123   register int tvalsaved;
 124
 125   ssp = yygssp;
 126   yyunlex(yychar, yylval, yylloc);
 127
 128   tvalsaved = 0;
 129   while (first != last)
 130     {
 131       symbol = yystos[*ssp];
 132       if (symbol < YYNTBASE)
 133         {
 134           yyunlex(symbol, yytval, yytloc);
 135           tvalsaved = 1;
 136           ssp--;
 137         }
 138
 139       ssp--;
 140
 141       if (first == yyrq)
 142         first = yyrq + YYMAXRULES;
 143
 144       first--;
 145
 146       for (rp = yyrhs + yyprhs[*first]; symbol = *rp; rp++)
 147         {
 148           if (symbol < YYNTBASE)
 149             state = yytable[yypact[*ssp] + symbol];
 150           else
 151             {
 152               state = yypgoto[symbol - YYNTBASE] + *ssp;
 153
 154               if (state >= 0 && state <= YYLAST && yycheck[state] == *ssp)
 155                 state = yytable[state];
 156               else
 157                 state = yydefgoto[symbol - YYNTBASE];
 158             }
 159
 160           *++ssp = state;
 161         }
 162     }
 163
 164   if ( ! tvalsaved && ssp > yyss)
 165     {
 166       yyunlex(yystos[*ssp], yytval, yytloc);
 167       ssp--;
 168     }
 169
 170   yygssp = ssp;
 171 }
 172
 173
 174
 175 int
 176 yyparse()
 177 {
 178   register int yystate;
 179   register int yyn;
 180   register short *yyssp;
 181   register short *yyrq0;
 182   register short *yyptr;
 183   register YYSTYPE *yyvsp;
 184
 185   int yylen;
 186   YYLTYPE *yylsp;
 187   short *yyrq1;
 188   short *yyrq2;
 189
 190   yystate = 0;
 191   yyssp = yyss - 1;
 192   yyvsp = yyvs - 1;
 193   yylsp = yyls - 1;
 194   yyrq0 = yyrq;
 195   yyrq1 = yyrq0;
 196   yyrq2 = yyrq0;
 197
 198   yychar = yylex();
 199   if (yychar < 0)
 200     yychar = 0;
 201   else yychar = YYTRANSLATE(yychar);
 202
 203 yynewstate:
 204
 205   if (yyssp >= yyss + YYMAXDEPTH - 1)
 206     {
 207       yyabort("Parser Stack Overflow");
 208       YYABORT;
 209     }
 210
 211   *++yyssp = yystate;
 212
 213 yyresume:
 214
 215   yyn = yypact[yystate];
 216   if (yyn == YYFLAG)
 217     goto yydefault;
 218
 219   yyn += yychar;
 220   if (yyn < 0 || yyn > YYLAST || yycheck[yyn] != yychar)
 221     goto yydefault;
 222
 223   yyn = yytable[yyn];
 224   if (yyn < 0)
 225     {
 226       yyn = -yyn;
 227       goto yyreduce;
 228     }
 229   else if (yyn == 0)
 230     goto yyerrlab;
 231
 232   yystate = yyn;
 233
 234   yyptr = yyrq2;
 235   while (yyptr != yyrq1)
 236     {
 237       yyn = *yyptr++;
 238       yylen = yyr2[yyn];
 239       yyvsp -= yylen;
 240       yylsp -= yylen;
 241
 242       yyguard(yyn, yyvsp, yylsp);
 243       if (yyerror)
 244         goto yysemerr;
 245
 246       yyaction(yyn, yyvsp, yylsp);
 247       *++yyvsp = yyval;
 248
 249       yylsp++;
 250       if (yylen == 0)
 251         {
 252           yylsp->timestamp = timeclock;
 253           yylsp->first_line = yytloc.first_line;
 254           yylsp->first_column = yytloc.first_column;
 255           yylsp->last_line = (yylsp-1)->last_line;
 256           yylsp->last_column = (yylsp-1)->last_column;
 257           yylsp->text = 0;
 258         }
 259       else
 260         {
 261           yylsp->last_line = (yylsp+yylen-1)->last_line;
 262           yylsp->last_column = (yylsp+yylen-1)->last_column;
 263         }
 264
 265       if (yyptr == yyrq + YYMAXRULES)
 266         yyptr = yyrq;
 267     }
 268
 269   if (yystate == YYFINAL)
 270     YYACCEPT;
 271
 272   yyrq2 = yyptr;
 273   yyrq1 = yyrq0;
 274
 275   *++yyvsp = yytval;
 276   *++yylsp = yytloc;
 277   yytval = yylval;
 278   yytloc = yylloc;
 279   yyget();
 280
 281   goto yynewstate;
 282
 283 yydefault:
 284
 285   yyn = yydefact[yystate];
 286   if (yyn == 0)
 287     goto yyerrlab;
 288
 289 yyreduce:
 290
 291   *yyrq0++ = yyn;
 292
 293   if (yyrq0 == yyrq + YYMAXRULES)
 294     yyrq0 = yyrq;
 295
 296   if (yyrq0 == yyrq2)
 297     {
 298       yyabort("Parser Rule Queue Overflow");
 299       YYABORT;
 300     }
 301
 302   yyssp -= yyr2[yyn];
 303   yyn = yyr1[yyn];
 304
 305   yystate = yypgoto[yyn - YYNTBASE] + *yyssp;
 306   if (yystate >= 0 && yystate <= YYLAST && yycheck[yystate] == *yyssp)
 307     yystate = yytable[yystate];
 308   else
 309     yystate = yydefgoto[yyn - YYNTBASE];
 310
 311   goto yynewstate;
 312
 313 yysemerr:
 314   *--yyptr = yyn;
 315   yyrq2 = yyptr;
 316   yyvsp += yyr2[yyn];
 317
 318 yyerrlab:
 319
 320   yygssp = yyssp;
 321   yygvsp = yyvsp;
 322   yyglsp = yylsp;
 323   yyrestore(yyrq0, yyrq2);
 324   yyrecover();
 325   yystate = *yygssp;
 326   yyssp = yygssp;
 327   yyvsp = yygvsp;
 328   yyrq0 = yyrq;
 329   yyrq1 = yyrq0;
 330   yyrq2 = yyrq0;
 331   goto yyresume;
 332 }
 333
 334 %% actions