src/main.c

   1 /* Top level entry point of Bison.
   2
   3    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000, 2001, 2002, 2004,
   4    2005, 2006, 2007 Free Software Foundation, Inc.
   5
   6    This file is part of Bison, the GNU Compiler Compiler.
   7
   8    Bison 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 2, or (at your option)
  11    any later version.
  12
  13    Bison 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 Bison; see the file COPYING.  If not, write to
  20    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, USA.  */
  22
  23 #include <config.h>
  24 #include "system.h"
  25
  26 #include <bitset_stats.h>
  27 #include <bitset.h>
  28 #include <configmake.h>
  29 #include <quotearg.h>
  30 #include <timevar.h>
  31
  32 #include "LR0.h"
  33 #include "complain.h"
  34 #include "conflicts.h"
  35 #include "derives.h"
  36 #include "files.h"
  37 #include "getargs.h"
  38 #include "gram.h"
  39 #include "lalr.h"
  40 #include "muscle_tab.h"
  41 #include "nullable.h"
  42 #include "output.h"
  43 #include "print.h"
  44 #include "print_graph.h"
  45 #include "reader.h"
  46 #include "reduce.h"
  47 #include "scan-code.h"
  48 #include "scan-gram.h"
  49 #include "scan-skel.h"
  50 #include "symtab.h"
  51 #include "tables.h"
  52 #include "uniqstr.h"
  53
  54
  55
  56 int
  57 main (int argc, char *argv[])
  58 {
  59   program_name = argv[0];
  60   setlocale (LC_ALL, "");
  61   (void) bindtextdomain (PACKAGE, LOCALEDIR);
  62   (void) bindtextdomain ("bison-runtime", LOCALEDIR);
  63   (void) textdomain (PACKAGE);
  64
  65   uniqstrs_new ();
  66
  67   getargs (argc, argv);
  68
  69   timevar_report = trace_flag & trace_time;
  70   init_timevar ();
  71   timevar_start (TV_TOTAL);
  72
  73   if (trace_flag & trace_bitsets)
  74     bitset_stats_enable ();
  75
  76   muscle_init ();
  77
  78   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  79      and FATTRS.  In file reader.c.  The other parts are recorded in
  80      the grammar; see gram.h.  */
  81
  82   timevar_push (TV_READER);
  83   reader ();
  84   timevar_pop (TV_READER);
  85
  86   if (complaint_issued)
  87     goto finish;
  88
  89   /* Find useless nonterminals and productions and reduce the grammar. */
  90   timevar_push (TV_REDUCE);
  91   reduce_grammar ();
  92   timevar_pop (TV_REDUCE);
  93
  94   /* Record other info about the grammar.  In files derives and
  95      nullable.  */
  96   timevar_push (TV_SETS);
  97   derives_compute ();
  98   nullable_compute ();
  99   timevar_pop (TV_SETS);
 100
 101   /* Convert to nondeterministic finite state machine.  In file LR0.
 102      See state.h for more info.  */
 103   timevar_push (TV_LR0);
 104   generate_states ();
 105   timevar_pop (TV_LR0);
 106
 107   /* make it deterministic.  In file lalr.  */
 108   timevar_push (TV_LALR);
 109   lalr ();
 110   timevar_pop (TV_LALR);
 111
 112   /* Find and record any conflicts: places where one token of
 113      lookahead is not enough to disambiguate the parsing.  In file
 114      conflicts.  Also resolve s/r conflicts based on precedence
 115      declarations.  */
 116   timevar_push (TV_CONFLICTS);
 117   conflicts_solve ();
 118   {
 119     state_number *old_to_new = xnmalloc (nstates, sizeof *old_to_new);
 120     state_number nstates_old = nstates;
 121     state_remove_unreachable_states (old_to_new);
 122     lalr_update_state_numbers (old_to_new, nstates_old);
 123     conflicts_update_state_numbers (old_to_new, nstates_old);
 124     free (old_to_new);
 125   }
 126   conflicts_print ();
 127   timevar_pop (TV_CONFLICTS);
 128
 129   /* Compute the parser tables.  */
 130   timevar_push (TV_ACTIONS);
 131   tables_generate ();
 132   timevar_pop (TV_ACTIONS);
 133
 134   grammar_rules_never_reduced_report
 135     (_("rule never reduced because of conflicts"));
 136
 137   /* Output file names. */
 138   compute_output_file_names ();
 139
 140   /* Output the detailed report on the grammar.  */
 141   if (report_flag)
 142     {
 143       timevar_push (TV_REPORT);
 144       print_results ();
 145       timevar_pop (TV_REPORT);
 146     }
 147
 148   /* Output the graph.  */
 149   if (graph_flag)
 150     {
 151       timevar_push (TV_GRAPH);
 152       print_graph ();
 153       timevar_pop (TV_GRAPH);
 154     }
 155
 156   /* Stop if there were errors, to avoid trashing previous output
 157      files.  */
 158   if (complaint_issued)
 159     goto finish;
 160
 161   /* Lookahead tokens are no longer needed. */
 162   timevar_push (TV_FREE);
 163   lalr_free ();
 164   timevar_pop (TV_FREE);
 165
 166   /* Output the tables and the parser to ftable.  In file output.  */
 167   timevar_push (TV_PARSER);
 168   output ();
 169   timevar_pop (TV_PARSER);
 170
 171   timevar_push (TV_FREE);
 172   nullable_free ();
 173   derives_free ();
 174   tables_free ();
 175   states_free ();
 176   reduce_free ();
 177   conflicts_free ();
 178   grammar_free ();
 179   output_file_names_free ();
 180
 181   /* The scanner memory cannot be released right after parsing, as it
 182      contains things such as user actions, prologue, epilogue etc.  */
 183   gram_scanner_free ();
 184   muscle_free ();
 185   uniqstrs_free ();
 186   code_scanner_free ();
 187   skel_scanner_free ();
 188   quotearg_free ();
 189   timevar_pop (TV_FREE);
 190
 191   if (trace_flag & trace_bitsets)
 192     bitset_stats_dump (stderr);
 193
 194  finish:
 195
 196   /* Stop timing and print the times.  */
 197   timevar_stop (TV_TOTAL);
 198   timevar_print (stderr);
 199
 200   return complaint_issued ? EXIT_FAILURE : EXIT_SUCCESS;
 201 }