src/state.c

   1 /* Type definitions for nondeterministic finite state machine for bison,
   2    Copyright (C) 2001, 2002  Free Software Foundation, Inc.
   3
   4    This file is part of Bison, the GNU Compiler Compiler.
   5
   6    Bison is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    Bison is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with Bison; see the file COPYING.  If not, write to
  18    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21
  22 #include "system.h"
  23 #include "gram.h"
  24 #include "state.h"
  25
  26 /*---------------------------------.
  27 | Create a new array of N shitfs.  |
  28 `---------------------------------*/
  29
  30 #define SHIFTS_ALLOC(Nshifts)                                           \
  31   (shifts *) xcalloc ((unsigned) (sizeof (shifts)                       \
  32                                   + (Nshifts - 1) * sizeof (short)), 1)
  33
  34 shifts *
  35 shifts_new (int n)
  36 {
  37   shifts *res = SHIFTS_ALLOC (n);
  38   res->nshifts = n;
  39   return res;
  40 }
  41
  42
  43 /*-------------------------------.
  44 | Create a new array of N errs.  |
  45 `-------------------------------*/
  46
  47 #define ERRS_ALLOC(Nerrs)                                               \
  48   (errs *) xcalloc ((unsigned) (sizeof (errs)                           \
  49                                   + (Nerrs - 1) * sizeof (short)), 1)
  50
  51
  52 errs *
  53 errs_new (int n)
  54 {
  55   errs *res = ERRS_ALLOC (n);
  56   res->nerrs = n;
  57   return res;
  58 }
  59
  60
  61 errs *
  62 errs_dup (errs *src)
  63 {
  64   errs *res = errs_new (src->nerrs);
  65   memcpy (res->errs, src->errs, src->nerrs * sizeof (src->errs[0]));
  66   return res;
  67 }
  68
  69 /*-------------------------------------.
  70 | Create a new array of N reductions.  |
  71 `-------------------------------------*/
  72
  73 #define REDUCTIONS_ALLOC(Nreductions)                                   \
  74   (reductions *) xcalloc ((unsigned) (sizeof (reductions)               \
  75                                   + (Nreductions - 1) * sizeof (short)), 1)
  76
  77 reductions *
  78 reductions_new (int n)
  79 {
  80   reductions *res = REDUCTIONS_ALLOC (n);
  81   res->nreds = n;
  82   return res;
  83 }
  84
  85
  86 /*--------------------------------------------------------------.
  87 | Print on OUT all the lookaheads such that this STATE wants to |
  88 | reduce this RULE.                                             |
  89 `--------------------------------------------------------------*/
  90
  91 void
  92 state_rule_lookaheads_print (state_t *state, rule_t *rule, FILE *out)
  93 {
  94   int j, k;
  95   int nlookaheads = 0;
  96   /* Count the number of lookaheads corresponding to this rule.  */
  97   for (j = 0; j < state->nlookaheads; ++j)
  98     for (k = 0; k < ntokens; ++k)
  99       if (bitset_test (state->lookaheads[j], k)
 100           && state->lookaheads_rule[j]->number == rule->number)
 101         nlookaheads++;
 102
 103   /* Print them if there are.  */
 104   if (nlookaheads)
 105     {
 106       fprintf (out, "  [");
 107       for (j = 0; j < state->nlookaheads; ++j)
 108         for (k = 0; k < ntokens; ++k)
 109           if (bitset_test (state->lookaheads[j], k)
 110               && state->lookaheads_rule[j]->number == rule->number)
 111             fprintf (out, "%s%s",
 112                      symbol_tag_get (symbols[k]),
 113                      --nlookaheads ? ", " : "");
 114       fprintf (out, "]");
 115     }
 116 }