src/gram.c

   1 /* Allocate input grammar variables for Bison.
   2
   3    Copyright (C) 1984, 1986, 1989, 2001, 2002, 2003, 2005, 2006
   4    2007 Free Software Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    This program is free software: you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation, either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include <config.h>
  22 #include "system.h"
  23
  24 #include <quotearg.h>
  25
  26 #include "gram.h"
  27 #include "reader.h"
  28 #include "reduce.h"
  29 #include "symtab.h"
  30 #include "print-xml.h"
  31
  32 /* Comments for these variables are in gram.h.  */
  33
  34 item_number *ritem = NULL;
  35 unsigned int nritems = 0;
  36
  37 rule *rules = NULL;
  38 rule_number nrules = 0;
  39
  40 symbol **symbols = NULL;
  41 int nsyms = 0;
  42 int ntokens = 1;
  43 int nvars = 0;
  44
  45 symbol_number *token_translations = NULL;
  46
  47 int max_user_token_number = 256;
  48
  49 /*--------------------------------------------------------------.
  50 | Return true IFF the rule has a `number' smaller than NRULES.  |
  51 `--------------------------------------------------------------*/
  52
  53 bool
  54 rule_useful_p (rule *r)
  55 {
  56   return r->number < nrules;
  57 }
  58
  59
  60 /*-------------------------------------------------------------.
  61 | Return true IFF the rule has a `number' higher than NRULES.  |
  62 `-------------------------------------------------------------*/
  63
  64 bool
  65 rule_useless_p (rule *r)
  66 {
  67   return !rule_useful_p (r);
  68 }
  69
  70
  71 /*--------------------------------------------------------------------.
  72 | Return true IFF the rule is not flagged as useful *and* is useful.  |
  73 | In other words, it was discarded because of conflicts.              |
  74 `--------------------------------------------------------------------*/
  75
  76 bool
  77 rule_never_reduced_p (rule *r)
  78 {
  79   return !r->useful && rule_useful_p (r);
  80 }
  81
  82
  83 /*----------------------------------------------------------------.
  84 | Print this RULE's number and lhs on OUT.  If a PREVIOUS_LHS was |
  85 | already displayed (by a previous call for another rule), avoid  |
  86 | useless repetitions.                                            |
  87 `----------------------------------------------------------------*/
  88
  89 void
  90 rule_lhs_print (rule *r, symbol *previous_lhs, FILE *out)
  91 {
  92   fprintf (out, "  %3d ", r->number);
  93   if (previous_lhs != r->lhs)
  94     {
  95       fprintf (out, "%s:", r->lhs->tag);
  96     }
  97   else
  98     {
  99       int n;
 100       for (n = strlen (previous_lhs->tag); n > 0; --n)
 101         fputc (' ', out);
 102       fputc ('|', out);
 103     }
 104 }
 105
 106 void
 107 rule_lhs_print_xml (rule *r, FILE *out, int level)
 108 {
 109   xml_printf (out, level, "<lhs>%s</lhs>", r->lhs->tag);
 110 }
 111
 112
 113 /*--------------------------------------.
 114 | Return the number of symbols in RHS.  |
 115 `--------------------------------------*/
 116
 117 int
 118 rule_rhs_length (rule *r)
 119 {
 120   int res = 0;
 121   item_number *rhsp;
 122   for (rhsp = r->rhs; *rhsp >= 0; ++rhsp)
 123     ++res;
 124   return res;
 125 }
 126
 127
 128 /*-------------------------------.
 129 | Print this rule's RHS on OUT.  |
 130 `-------------------------------*/
 131
 132 void
 133 rule_rhs_print (rule *r, FILE *out)
 134 {
 135   if (*r->rhs >= 0)
 136     {
 137       item_number *rp;
 138       for (rp = r->rhs; *rp >= 0; rp++)
 139         fprintf (out, " %s", symbols[*rp]->tag);
 140       fputc ('\n', out);
 141     }
 142   else
 143     {
 144       fprintf (out, " /* %s */\n", _("empty"));
 145     }
 146 }
 147
 148 static void
 149 rule_rhs_print_xml (rule *r, FILE *out, int level)
 150 {
 151   if (*r->rhs >= 0)
 152     {
 153       item_number *rp;
 154       xml_puts (out, level, "<rhs>");
 155       for (rp = r->rhs; *rp >= 0; rp++)
 156         xml_printf (out, level + 1, "<symbol class=\"%s\">%s</symbol>",
 157                     symbol_class_get_string (symbols[*rp]),
 158                     xml_escape (symbols[*rp]->tag));
 159       xml_puts (out, level, "</rhs>");
 160     }
 161   else
 162     {
 163       xml_puts (out, level, "<rhs>");
 164       xml_puts (out, level + 1, "<empty/>");
 165       xml_puts (out, level, "</rhs>");
 166     }
 167 }
 168
 169 /*-------------------------.
 170 | Print this rule on OUT.  |
 171 `-------------------------*/
 172
 173 void
 174 rule_print (rule *r, FILE *out)
 175 {
 176   fprintf (out, "%s:", r->lhs->tag);
 177   rule_rhs_print (r, out);
 178 }
 179
 180
 181 /*------------------------.
 182 | Dump RITEM for traces.  |
 183 `------------------------*/
 184
 185 void
 186 ritem_print (FILE *out)
 187 {
 188   unsigned int i;
 189   fputs ("RITEM\n", out);
 190   for (i = 0; i < nritems; ++i)
 191     if (ritem[i] >= 0)
 192       fprintf (out, "  %s", symbols[ritem[i]]->tag);
 193     else
 194       fprintf (out, "  (rule %d)\n", item_number_as_rule_number (ritem[i]));
 195   fputs ("\n\n", out);
 196 }
 197
 198
 199 /*------------------------------------------.
 200 | Return the size of the longest rule RHS.  |
 201 `------------------------------------------*/
 202
 203 size_t
 204 ritem_longest_rhs (void)
 205 {
 206   int max = 0;
 207   rule_number r;
 208
 209   for (r = 0; r < nrules; ++r)
 210     {
 211       int length = rule_rhs_length (&rules[r]);
 212       if (length > max)
 213         max = length;
 214     }
 215
 216   return max;
 217 }
 218
 219
 220 /*-----------------------------------------------------------------.
 221 | Print the grammar's rules that match FILTER on OUT under TITLE.  |
 222 `-----------------------------------------------------------------*/
 223
 224 void
 225 grammar_rules_partial_print (FILE *out, const char *title,
 226                              rule_filter filter)
 227 {
 228   rule_number r;
 229   bool first = true;
 230   symbol *previous_lhs = NULL;
 231
 232   /* rule # : LHS -> RHS */
 233   for (r = 0; r < nrules + nuseless_productions; r++)
 234     {
 235       if (filter && !filter (&rules[r]))
 236         continue;
 237       if (first)
 238         fprintf (out, "%s\n\n", title);
 239       else if (previous_lhs && previous_lhs != rules[r].lhs)
 240         fputc ('\n', out);
 241       first = false;
 242       rule_lhs_print (&rules[r], previous_lhs, out);
 243       rule_rhs_print (&rules[r], out);
 244       previous_lhs = rules[r].lhs;
 245     }
 246   if (!first)
 247     fputs ("\n\n", out);
 248 }
 249
 250
 251 /*----------------------------------------------------------.
 252 | Print the grammar's rules that match FILTER on OUT (XML). |
 253 `-----------------------------------------------------------*/
 254
 255 void
 256 grammar_rules_partial_print_xml (FILE *out, int level, bool rtag,
 257                                  rule_filter filter)
 258 {
 259   rule_number r;
 260   bool first = true;
 261
 262   for (r = 0; r < nrules + nuseless_productions; r++)
 263     {
 264       if (filter && !filter (&rules[r]))
 265         continue;
 266       if (rtag && first)
 267         xml_puts (out, level + 1, "<rules>");
 268       first = false;
 269
 270       xml_printf (out, level + 2, "<rule number=\"%d\">",
 271                   rules[r].number);
 272       rule_lhs_print_xml (&rules[r], out, level + 3);
 273       rule_rhs_print_xml (&rules[r], out, level + 3);
 274       xml_puts (out, level + 2, "</rule>");
 275     }
 276   if (rtag)
 277     {
 278       if (!first)
 279         xml_puts (out, level + 1, "</rules>");
 280       else
 281         xml_puts (out, level + 1, "<rules/>");
 282     }
 283 }
 284
 285 /*------------------------------------------.
 286 | Print the grammar's useful rules on OUT.  |
 287 `------------------------------------------*/
 288
 289 void
 290 grammar_rules_print (FILE *out)
 291 {
 292   grammar_rules_partial_print (out, _("Grammar"), rule_useful_p);
 293 }
 294
 295 void
 296 grammar_rules_print_xml (FILE *out, int level)
 297 {
 298   grammar_rules_partial_print_xml (out, level, true, rule_useful_p);
 299 }
 300
 301
 302 /*-------------------.
 303 | Dump the grammar.  |
 304 `-------------------*/
 305
 306 void
 307 grammar_dump (FILE *out, const char *title)
 308 {
 309   fprintf (out, "%s\n\n", title);
 310   fprintf (out,
 311            "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nritems = %d\n\n",
 312            ntokens, nvars, nsyms, nrules, nritems);
 313
 314
 315   fprintf (out, "Variables\n---------\n\n");
 316   {
 317     symbol_number i;
 318     fprintf (out, "Value  Sprec  Sassoc  Tag\n");
 319
 320     for (i = ntokens; i < nsyms; i++)
 321       fprintf (out, "%5d  %5d   %5d  %s\n",
 322                i,
 323                symbols[i]->prec, symbols[i]->assoc,
 324                symbols[i]->tag);
 325     fprintf (out, "\n\n");
 326   }
 327
 328   fprintf (out, "Rules\n-----\n\n");
 329   {
 330     rule_number i;
 331     fprintf (out, "Num (Prec, Assoc, Useful, Ritem Range) Lhs -> Rhs (Ritem range) [Num]\n");
 332     for (i = 0; i < nrules + nuseless_productions; i++)
 333       {
 334         rule *rule_i = &rules[i];
 335         item_number *rp = NULL;
 336         unsigned int rhs_itemno = rule_i->rhs - ritem;
 337         unsigned int rhs_count = 0;
 338         /* Find the last RHS index in ritems. */
 339         for (rp = rule_i->rhs; *rp >= 0; ++rp)
 340           ++rhs_count;
 341         fprintf (out, "%3d (%2d, %2d, %2d, %2u-%2u)   %2d ->",
 342                  i,
 343                  rule_i->prec ? rule_i->prec->prec : 0,
 344                  rule_i->prec ? rule_i->prec->assoc : 0,
 345                  rule_i->useful,
 346                  rhs_itemno,
 347                  rhs_itemno + rhs_count - 1,
 348                  rule_i->lhs->number);
 349         /* Dumped the RHS. */
 350         for (rp = rule_i->rhs; *rp >= 0; rp++)
 351           fprintf (out, " %3d", *rp);
 352         fprintf (out, "  [%d]\n", item_number_as_rule_number (*rp));
 353       }
 354   }
 355   fprintf (out, "\n\n");
 356
 357   fprintf (out, "Rules interpreted\n-----------------\n\n");
 358   {
 359     rule_number r;
 360     for (r = 0; r < nrules + nuseless_productions; r++)
 361       {
 362         fprintf (out, "%-5d  ", r);
 363         rule_print (&rules[r], out);
 364       }
 365   }
 366   fprintf (out, "\n\n");
 367 }
 368
 369
 370 /*------------------------------------------------------------------.
 371 | Report on STDERR the rules that are not flagged USEFUL, using the |
 372 | MESSAGE (which can be `useless rule' when invoked after grammar   |
 373 | reduction, or `never reduced' after conflicts were taken into     |
 374 | account).                                                         |
 375 `------------------------------------------------------------------*/
 376
 377 void
 378 grammar_rules_never_reduced_report (const char *message)
 379 {
 380   rule_number r;
 381   for (r = 0; r < nrules ; ++r)
 382     if (!rules[r].useful)
 383       {
 384         location_print (stderr, rules[r].location);
 385         fprintf (stderr, ": %s: %s: ", _("warning"), message);
 386         rule_print (&rules[r], stderr);
 387       }
 388 }
 389
 390 void
 391 grammar_free (void)
 392 {
 393   if (ritem)
 394     free (ritem - 1);
 395   free (rules);
 396   free (token_translations);
 397   /* Free the symbol table data structure.  */
 398   symbols_free ();
 399   free_merger_functions ();
 400 }