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
  94   getargs (argc, argv);
  95
  96   timevar_enabled = trace_flag & trace_time;
  97   timevar_init ();
  98   timevar_start (tv_total);
  99
 100   if (trace_flag & trace_bitsets)
 101     bitset_stats_enable ();
 102
 103   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
 104      and FATTRS.  In file reader.c.  The other parts are recorded in
 105      the grammar; see gram.h.  */
 106
 107   timevar_push (tv_reader);
 108   reader (grammar_file);
 109   timevar_pop (tv_reader);
 110
 111   if (complaint_status == status_complaint)
 112     goto finish;
 113
 114   /* Find useless nonterminals and productions and reduce the grammar. */
 115   timevar_push (tv_reduce);
 116   reduce_grammar ();
 117   timevar_pop (tv_reduce);
 118
 119   /* Record other info about the grammar.  In files derives and
 120      nullable.  */
 121   timevar_push (tv_sets);
 122   derives_compute ();
 123   nullable_compute ();
 124   timevar_pop (tv_sets);
 125
 126   /* Compute LR(0) parser states.  See state.h for more info.  */
 127   timevar_push (tv_lr0);
 128   generate_states ();
 129   timevar_pop (tv_lr0);
 130
 131   /* Add lookahead sets to parser states.  Except when LALR(1) is
 132      requested, split states to eliminate LR(1)-relative
 133      inadequacies.  */
 134   ielr ();
 135
 136   /* Find and record any conflicts: places where one token of
 137      lookahead is not enough to disambiguate the parsing.  In file
 138      conflicts.  Also resolve s/r conflicts based on precedence
 139      declarations.  */
 140   timevar_push (tv_conflicts);
 141   conflicts_solve ();
 142   if (!muscle_percent_define_flag_if ("lr.keep-unreachable-state"))
 143     {
 144       state_number *old_to_new = xnmalloc (nstates, sizeof *old_to_new);
 145       state_number nstates_old = nstates;
 146       state_remove_unreachable_states (old_to_new);
 147       lalr_update_state_numbers (old_to_new, nstates_old);
 148       conflicts_update_state_numbers (old_to_new, nstates_old);
 149       free (old_to_new);
 150     }
 151   if (report_flag & report_cex
 152       || warning_is_enabled (Wcounterexamples))
 153     counterexample_init ();
 154   conflicts_print ();
 155   timevar_pop (tv_conflicts);
 156
 157   /* Compute the parser tables.  */
 158   timevar_push (tv_actions);
 159   tables_generate ();
 160   timevar_pop (tv_actions);
 161
 162   grammar_rules_useless_report (_("rule useless in parser due to conflicts"));
 163
 164   print_precedence_warnings ();
 165
 166   /* Whether to generate output files.  */
 167   bool generate = !(feature_flag & feature_syntax_only);
 168
 169   if (generate)
 170     {
 171       /* Output file names. */
 172       compute_output_file_names ();
 173
 174       /* Output the detailed report on the grammar.  */
 175       if (report_flag)
 176         {
 177           timevar_push (tv_report);
 178           print_results ();
 179           timevar_pop (tv_report);
 180         }
 181
 182       /* Output the graph.  */
 183       if (graph_flag)
 184         {
 185           timevar_push (tv_graph);
 186           print_graph ();
 187           timevar_pop (tv_graph);
 188         }
 189
 190       /* Output xml.  */
 191       if (xml_flag)
 192         {
 193           timevar_push (tv_xml);
 194           print_xml ();
 195           timevar_pop (tv_xml);
 196         }
 197     }
 198
 199   /* Stop if there were errors, to avoid trashing previous output
 200      files.  */
 201   if (complaint_status == status_complaint)
 202     goto finish;
 203
 204   /* Lookahead tokens are no longer needed. */
 205   timevar_push (tv_free);
 206   lalr_free ();
 207   timevar_pop (tv_free);
 208
 209   /* Output the tables and the parser to ftable.  In file output.  */
 210   if (generate)
 211     {
 212       timevar_push (tv_parser);
 213       output ();
 214       timevar_pop (tv_parser);
 215     }
 216
 217  finish:
 218
 219   timevar_push (tv_free);
 220   nullable_free ();
 221   derives_free ();
 222   tables_free ();
 223   states_free ();
 224   reduce_free ();
 225   conflicts_free ();
 226   grammar_free ();
 227   counterexample_free ();
 228   output_file_names_free ();
 229
 230   /* The scanner and parser memory cannot be released right after
 231      parsing, as it contains things such as user actions, prologue,
 232      epilogue etc.  */
 233   gram_scanner_free ();
 234   parser_free ();
 235
 236   muscle_free ();
 237   code_scanner_free ();
 238   skel_scanner_free ();
 239   timevar_pop (tv_free);
 240
 241   if (trace_flag & trace_bitsets)
 242     bitset_stats_dump (stderr);
 243
 244   /* Stop timing and print the times.  */
 245   timevar_stop (tv_total);
 246   timevar_print (stderr);
 247
 248   /* Fix input file now, even if there are errors: that's less
 249      warnings in the following runs.  */
 250   if (!fixits_empty ())
 251     {
 252       if (update_flag)
 253         fixits_run ();
 254       else
 255         complain (NULL, Wother,
 256                   _("fix-its can be applied.  Rerun with option '--update'."));
 257       fixits_free ();
 258     }
 259   uniqstrs_free ();
 260
 261   complain_free ();
 262   quotearg_free ();
 263
 264   return complaint_status ? EXIT_FAILURE : EXIT_SUCCESS;
 265 }