src/gram.c

   1 /* Allocate input grammar variables for Bison.
   2
   3    Copyright (C) 1984, 1986, 1989, 2001-2003, 2005-2015, 2018 Free
   4    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 "complain.h"
  25 #include "getargs.h"
  26 #include "gram.h"
  27 #include "print-xml.h"
  28 #include "reader.h"
  29 #include "reduce.h"
  30 #include "symtab.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 bool
  50 rule_useful_in_grammar_p (rule const *r)
  51 {
  52   return r->number < nrules;
  53 }
  54
  55 bool
  56 rule_useless_in_grammar_p (rule const *r)
  57 {
  58   return !rule_useful_in_grammar_p (r);
  59 }
  60
  61 bool
  62 rule_useless_in_parser_p (rule const *r)
  63 {
  64   return !r->useful && rule_useful_in_grammar_p (r);
  65 }
  66
  67 void
  68 rule_lhs_print (rule const *r, sym_content const *previous_lhs, FILE *out)
  69 {
  70   fprintf (out, "  %3d ", r->number);
  71   if (previous_lhs != r->lhs)
  72     fprintf (out, "%s:", r->lhs->symbol->tag);
  73   else
  74     fprintf (out, "%*s|", (int) strlen (previous_lhs->symbol->tag), "");
  75 }
  76
  77 void
  78 rule_lhs_print_xml (rule const *r, FILE *out, int level)
  79 {
  80   xml_printf (out, level, "<lhs>%s</lhs>", r->lhs->symbol->tag);
  81 }
  82
  83 size_t
  84 rule_rhs_length (rule const *r)
  85 {
  86   size_t res = 0;
  87   item_number *rhsp;
  88   for (rhsp = r->rhs; *rhsp >= 0; ++rhsp)
  89     ++res;
  90   return res;
  91 }
  92
  93 void
  94 rule_rhs_print (rule const *r, FILE *out)
  95 {
  96   if (0 <= *r->rhs)
  97     {
  98       item_number *rp;
  99       for (rp = r->rhs; *rp >= 0; rp++)
 100         fprintf (out, " %s", symbols[*rp]->tag);
 101     }
 102   else
 103     fputs (" %empty", out);
 104 }
 105
 106 static void
 107 rule_rhs_print_xml (rule const *r, FILE *out, int level)
 108 {
 109   if (*r->rhs >= 0)
 110     {
 111       item_number *rp;
 112       xml_puts (out, level, "<rhs>");
 113       for (rp = r->rhs; *rp >= 0; rp++)
 114         xml_printf (out, level + 1, "<symbol>%s</symbol>",
 115                     xml_escape (symbols[*rp]->tag));
 116       xml_puts (out, level, "</rhs>");
 117     }
 118   else
 119     {
 120       xml_puts (out, level, "<rhs>");
 121       xml_puts (out, level + 1, "<empty/>");
 122       xml_puts (out, level, "</rhs>");
 123     }
 124 }
 125
 126 void
 127 ritem_print (FILE *out)
 128 {
 129   unsigned int i;
 130   fputs ("RITEM\n", out);
 131   for (i = 0; i < nritems; ++i)
 132     if (ritem[i] >= 0)
 133       fprintf (out, "  %s", symbols[ritem[i]]->tag);
 134     else
 135       fprintf (out, "  (rule %d)\n", item_number_as_rule_number (ritem[i]));
 136   fputs ("\n\n", out);
 137 }
 138
 139 size_t
 140 ritem_longest_rhs (void)
 141 {
 142   int max = 0;
 143   rule_number r;
 144
 145   for (r = 0; r < nrules; ++r)
 146     {
 147       int length = rule_rhs_length (&rules[r]);
 148       if (length > max)
 149         max = length;
 150     }
 151
 152   return max;
 153 }
 154
 155 void
 156 grammar_rules_partial_print (FILE *out, const char *title,
 157                              rule_filter filter)
 158 {
 159   rule_number r;
 160   bool first = true;
 161   sym_content *previous_lhs = NULL;
 162
 163   /* rule # : LHS -> RHS */
 164   for (r = 0; r < nrules + nuseless_productions; r++)
 165     {
 166       if (filter && !filter (&rules[r]))
 167         continue;
 168       if (first)
 169         fprintf (out, "%s\n\n", title);
 170       else if (previous_lhs && previous_lhs != rules[r].lhs)
 171         fputc ('\n', out);
 172       first = false;
 173       rule_lhs_print (&rules[r], previous_lhs, out);
 174       rule_rhs_print (&rules[r], out);
 175       fprintf (out, "\n");
 176       previous_lhs = rules[r].lhs;
 177     }
 178   if (!first)
 179     fputs ("\n\n", out);
 180 }
 181
 182 void
 183 grammar_rules_print (FILE *out)
 184 {
 185   grammar_rules_partial_print (out, _("Grammar"), rule_useful_in_grammar_p);
 186 }
 187
 188 void
 189 grammar_rules_print_xml (FILE *out, int level)
 190 {
 191   rule_number r;
 192   bool first = true;
 193
 194   for (r = 0; r < nrules + nuseless_productions; r++)
 195     {
 196       if (first)
 197         xml_puts (out, level + 1, "<rules>");
 198       first = false;
 199       {
 200         char const *usefulness;
 201         if (rule_useless_in_grammar_p (&rules[r]))
 202           usefulness = "useless-in-grammar";
 203         else if (rule_useless_in_parser_p (&rules[r]))
 204           usefulness = "useless-in-parser";
 205         else
 206           usefulness = "useful";
 207         xml_indent (out, level + 2);
 208         fprintf (out, "<rule number=\"%d\" usefulness=\"%s\"",
 209                  rules[r].number, usefulness);
 210         if (rules[r].precsym)
 211           fprintf (out, " percent_prec=\"%s\"",
 212                    xml_escape (rules[r].precsym->symbol->tag));
 213         fputs (">\n", out);
 214       }
 215       rule_lhs_print_xml (&rules[r], out, level + 3);
 216       rule_rhs_print_xml (&rules[r], out, level + 3);
 217       xml_puts (out, level + 2, "</rule>");
 218     }
 219   if (!first)
 220     xml_puts (out, level + 1, "</rules>");
 221   else
 222    xml_puts (out, level + 1, "<rules/>");
 223 }
 224
 225 void
 226 grammar_dump (FILE *out, const char *title)
 227 {
 228   fprintf (out, "%s\n\n", title);
 229   fprintf (out,
 230            "ntokens = %d, nvars = %d, nsyms = %d, nrules = %d, nritems = %d\n\n",
 231            ntokens, nvars, nsyms, nrules, nritems);
 232
 233
 234   fprintf (out, "Variables\n---------\n\n");
 235   {
 236     symbol_number i;
 237     fprintf (out, "Value  Sprec  Sassoc  Tag\n");
 238
 239     for (i = ntokens; i < nsyms; i++)
 240       fprintf (out, "%5d  %5d   %5d  %s\n",
 241                i,
 242                symbols[i]->content->prec, symbols[i]->content->assoc,
 243                symbols[i]->tag);
 244     fprintf (out, "\n\n");
 245   }
 246
 247   fprintf (out, "Rules\n-----\n\n");
 248   {
 249     rule_number i;
 250     fprintf (out,
 251              "Num (Prec, Assoc, Useful, Ritem Range) Lhs"
 252              " -> Rhs (Ritem range) [Num]\n");
 253     for (i = 0; i < nrules + nuseless_productions; i++)
 254       {
 255         rule const *rule_i = &rules[i];
 256         item_number *rp = NULL;
 257         unsigned int rhs_itemno = rule_i->rhs - ritem;
 258         unsigned int rhs_count = 0;
 259         /* Find the last RHS index in ritems. */
 260         for (rp = rule_i->rhs; *rp >= 0; ++rp)
 261           ++rhs_count;
 262         fprintf (out, "%3d (%2d, %2d, %2d, %2u-%2u)   %2d ->",
 263                  i,
 264                  rule_i->prec ? rule_i->prec->prec : 0,
 265                  rule_i->prec ? rule_i->prec->assoc : 0,
 266                  rule_i->useful,
 267                  rhs_itemno,
 268                  rhs_itemno + rhs_count - 1,
 269                  rule_i->lhs->number);
 270         /* Dumped the RHS. */
 271         for (rp = rule_i->rhs; *rp >= 0; rp++)
 272           fprintf (out, " %3d", *rp);
 273         fprintf (out, "  [%d]\n", item_number_as_rule_number (*rp));
 274       }
 275   }
 276   fprintf (out, "\n\n");
 277
 278   fprintf (out, "Rules interpreted\n-----------------\n\n");
 279   {
 280     rule_number r;
 281     for (r = 0; r < nrules + nuseless_productions; r++)
 282       {
 283         fprintf (out, "%-5d  %s:", r, rules[r].lhs->symbol->tag);
 284         rule_rhs_print (&rules[r], out);
 285         fprintf (out, "\n");
 286       }
 287   }
 288   fprintf (out, "\n\n");
 289 }
 290
 291 void
 292 grammar_rules_useless_report (const char *message)
 293 {
 294   rule_number r;
 295   for (r = 0; r < nrules ; ++r)
 296     /* Don't complain about rules whose LHS is useless, we already
 297        complained about it.  */
 298     if (!reduce_nonterminal_useless_in_grammar (rules[r].lhs)
 299         && !rules[r].useful)
 300       complain (&rules[r].location, Wother, "%s", message);
 301 }
 302
 303 void
 304 grammar_free (void)
 305 {
 306   if (ritem)
 307     free (ritem - 1);
 308   free (rules);
 309   free (token_translations);
 310   /* Free the symbol table data structure.  */
 311   symbols_free ();
 312   free_merger_functions ();
 313 }