src/main.c

   1 /* Top level entry point of Bison.
   2
   3    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000-2002, 2004-2015,
   4    2018-2021 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 <https://www.gnu.org/licenses/>.  */
  20
  21 #include <config.h>
  22 #include "system.h"
  23
  24 #include <bitset.h>
  25 #include <bitset/stats.h>
  26 #include <closeout.h>
  27 #include <configmake.h>
  28 #include <progname.h>
  29 #include <quote.h>
  30 #include <quotearg.h>
  31 #include <relocatable.h> /* relocate2 */
  32 #include <timevar.h>
  33
  34 #include "complain.h"
  35 #include "conflicts.h"
  36 #include "counterexample.h"
  37 #include "derives.h"
  38 #include "files.h"
  39 #include "fixits.h"
  40 #include "getargs.h"
  41 #include "glyphs.h"
  42 #include "gram.h"
  43 #include "ielr.h"
  44 #include "lalr.h"
  45 #include "lr0.h"
  46 #include "muscle-tab.h"
  47 #include "nullable.h"
  48 #include "output.h"
  49 #include "parse-gram.h"
  50 #include "print-graph.h"
  51 #include "print-xml.h"
  52 #include "print.h"
  53 #include "reader.h"
  54 #include "reduce.h"
  55 #include "scan-code.h"
  56 #include "scan-gram.h"
  57 #include "scan-skel.h"
  58 #include "symtab.h"
  59 #include "tables.h"
  60 #include "uniqstr.h"
  61
  62
  63 int
  64 main (int argc, char *argv[])
  65 {
  66 #define DEPENDS_ON_LIBINTL 1
  67   set_program_name (argv[0]);
  68   setlocale (LC_ALL, "");
  69   {
  70     char *cp = NULL;
  71     char const *localedir = relocate2 (LOCALEDIR, &cp);
  72     bindtextdomain ("bison", localedir);
  73     bindtextdomain ("bison-gnulib", localedir);
  74     bindtextdomain ("bison-runtime", localedir);
  75     free (cp);
  76   }
  77   textdomain ("bison");
  78
  79   {
  80     char const *cp = getenv ("LC_CTYPE");
  81     if (cp && STREQ (cp, "C"))
  82       set_custom_quoting (&quote_quoting_options, "'", "'");
  83     else
  84       set_quoting_style (&quote_quoting_options, locale_quoting_style);
  85   }
  86
  87   atexit (close_stdout);
  88
  89   glyphs_init ();
  90   uniqstrs_new ();
  91   muscle_init ();
  92   complain_init ();
  93   code_scanner_init ();
  94
  95   getargs (argc, argv);
  96
  97   if (trace_flag)
  98     fprintf (stderr, "bison (GNU Bison) %s\n", VERSION);
  99
 100   timevar_enabled = trace_flag & trace_time;
 101   timevar_init ();
 102   timevar_start (tv_total);
 103
 104   if (trace_flag & trace_bitsets)
 105     bitset_stats_enable ();
 106
 107   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
 108      and FATTRS.  In file reader.c.  The other parts are recorded in
 109      the grammar; see gram.h.  */
 110
 111   timevar_push (tv_reader);
 112   reader (grammar_file);
 113   timevar_pop (tv_reader);
 114
 115   if (complaint_status == status_complaint)
 116     goto finish;
 117
 118   /* Find useless nonterminals and productions and reduce the grammar. */
 119   timevar_push (tv_reduce);
 120   reduce_grammar ();
 121   timevar_pop (tv_reduce);
 122
 123   /* Record other info about the grammar.  In files derives and
 124      nullable.  */
 125   timevar_push (tv_sets);
 126   derives_compute ();
 127   nullable_compute ();
 128   timevar_pop (tv_sets);
 129
 130   /* Compute LR(0) parser states.  See state.h for more info.  */
 131   timevar_push (tv_lr0);
 132   generate_states ();
 133   timevar_pop (tv_lr0);
 134
 135   /* Add lookahead sets to parser states.  Except when LALR(1) is
 136      requested, split states to eliminate LR(1)-relative
 137      inadequacies.  */
 138   ielr ();
 139
 140   /* Find and record any conflicts: places where one token of
 141      lookahead is not enough to disambiguate the parsing.  In file
 142      conflicts.  Also resolve s/r conflicts based on precedence
 143      declarations.  */
 144   timevar_push (tv_conflicts);
 145   conflicts_solve ();
 146   if (!muscle_percent_define_flag_if ("lr.keep-unreachable-state"))
 147     {
 148       state_number *old_to_new = xnmalloc (nstates, sizeof *old_to_new);
 149       state_number nstates_old = nstates;
 150       state_remove_unreachable_states (old_to_new);
 151       lalr_update_state_numbers (old_to_new, nstates_old);
 152       conflicts_update_state_numbers (old_to_new, nstates_old);
 153       free (old_to_new);
 154     }
 155   if (report_flag & report_cex
 156       || warning_is_enabled (Wcounterexamples))
 157     counterexample_init ();
 158   conflicts_print ();
 159   timevar_pop (tv_conflicts);
 160
 161   /* Compute the parser tables.  */
 162   timevar_push (tv_actions);
 163   tables_generate ();
 164   timevar_pop (tv_actions);
 165
 166   grammar_rules_useless_report (_("rule useless in parser due to conflicts"));
 167
 168   print_precedence_warnings ();
 169
 170   /* Whether to generate output files.  */
 171   bool generate = !(feature_flag & feature_syntax_only);
 172
 173   if (generate)
 174     {
 175       /* Output file names. */
 176       compute_output_file_names ();
 177
 178       /* Output the detailed report on the grammar.  */
 179       if (report_flag)
 180         {
 181           timevar_push (tv_report);
 182           print_results ();
 183           timevar_pop (tv_report);
 184         }
 185
 186       /* Output the graph.  */
 187       if (graph_flag)
 188         {
 189           timevar_push (tv_graph);
 190           print_graph ();
 191           timevar_pop (tv_graph);
 192         }
 193
 194       /* Output xml.  */
 195       if (html_flag || xml_flag)
 196         {
 197           timevar_push (tv_xml);
 198           print_xml ();
 199           timevar_pop (tv_xml);
 200         }
 201
 202       /* Output html.  */
 203       if (html_flag)
 204         {
 205           timevar_push (tv_html);
 206           print_html ();
 207           timevar_pop (tv_html);
 208         }
 209     }
 210
 211   /* Stop if there were errors, to avoid trashing previous output
 212      files.  */
 213   if (complaint_status == status_complaint)
 214     goto finish;
 215
 216   /* Lookahead tokens are no longer needed. */
 217   timevar_push (tv_free);
 218   lalr_free ();
 219   timevar_pop (tv_free);
 220
 221   /* Output the tables and the parser to ftable.  In file output.  */
 222   if (generate)
 223     {
 224       timevar_push (tv_parser);
 225       output ();
 226       timevar_pop (tv_parser);
 227     }
 228
 229  finish:
 230
 231   timevar_push (tv_free);
 232   nullable_free ();
 233   derives_free ();
 234   tables_free ();
 235   states_free ();
 236   reduce_free ();
 237   conflicts_free ();
 238   grammar_free ();
 239   counterexample_free ();
 240   output_file_names_free ();
 241
 242   /* The scanner and parser memory cannot be released right after
 243      parsing, as it contains things such as user actions, prologue,
 244      epilogue etc.  */
 245   gram_scanner_free ();
 246   parser_free ();
 247
 248   muscle_free ();
 249   code_scanner_free ();
 250   skel_scanner_free ();
 251   timevar_pop (tv_free);
 252
 253   if (trace_flag & trace_bitsets)
 254     bitset_stats_dump (stderr);
 255
 256   /* Stop timing and print the times.  */
 257   timevar_stop (tv_total);
 258   timevar_print (stderr);
 259
 260   /* Fix input file now, even if there are errors: that's less
 261      warnings in the following runs.  */
 262   if (!fixits_empty ())
 263     {
 264       if (update_flag)
 265         fixits_run ();
 266       else
 267         complain (NULL, Wother,
 268                   _("fix-its can be applied.  Rerun with option '--update'."));
 269       fixits_free ();
 270     }
 271   uniqstrs_free ();
 272
 273   complain_free ();
 274   quotearg_free ();
 275
 276   return complaint_status ? EXIT_FAILURE : EXIT_SUCCESS;
 277 }