src/main.c

   1 /* Top level entry point of Bison.
   2
   3    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000-2002, 2004-2011 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 <bitset_stats.h>
  25 #include <bitset.h>
  26 #include <configmake.h>
  27 #include <quotearg.h>
  28 #include <timevar.h>
  29
  30 #include "LR0.h"
  31 #include "complain.h"
  32 #include "conflicts.h"
  33 #include "derives.h"
  34 #include "files.h"
  35 #include "getargs.h"
  36 #include "gram.h"
  37 #include "lalr.h"
  38 #include "ielr.h"
  39 #include "muscle-tab.h"
  40 #include "nullable.h"
  41 #include "output.h"
  42 #include "print.h"
  43 #include "print_graph.h"
  44 #include "print-xml.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   muscle_init ();
  67
  68   getargs (argc, argv);
  69
  70   timevar_report = trace_flag & trace_time;
  71   init_timevar ();
  72   timevar_start (TV_TOTAL);
  73
  74   if (trace_flag & trace_bitsets)
  75     bitset_stats_enable ();
  76
  77   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  78      and FATTRS.  In file reader.c.  The other parts are recorded in
  79      the grammar; see gram.h.  */
  80
  81   timevar_push (TV_READER);
  82   reader ();
  83   timevar_pop (TV_READER);
  84
  85   if (complaint_issued)
  86     goto finish;
  87
  88   /* Find useless nonterminals and productions and reduce the grammar. */
  89   timevar_push (TV_REDUCE);
  90   reduce_grammar ();
  91   timevar_pop (TV_REDUCE);
  92
  93   /* Record other info about the grammar.  In files derives and
  94      nullable.  */
  95   timevar_push (TV_SETS);
  96   derives_compute ();
  97   nullable_compute ();
  98   timevar_pop (TV_SETS);
  99
 100   /* Compute LR(0) parser states.  See state.h for more info.  */
 101   timevar_push (TV_LR0);
 102   generate_states ();
 103   timevar_pop (TV_LR0);
 104
 105   /* Add lookahead sets to parser states.  Except when LALR(1) is
 106      requested, split states to eliminate LR(1)-relative
 107      inadequacies.  */
 108   ielr ();
 109
 110   /* Find and record any conflicts: places where one token of
 111      lookahead is not enough to disambiguate the parsing.  In file
 112      conflicts.  Also resolve s/r conflicts based on precedence
 113      declarations.  */
 114   timevar_push (TV_CONFLICTS);
 115   conflicts_solve ();
 116   if (!muscle_percent_define_flag_if ("lr.keep-unreachable-states"))
 117     {
 118       state_number *old_to_new = xnmalloc (nstates, sizeof *old_to_new);
 119       state_number nstates_old = nstates;
 120       state_remove_unreachable_states (old_to_new);
 121       lalr_update_state_numbers (old_to_new, nstates_old);
 122       conflicts_update_state_numbers (old_to_new, nstates_old);
 123       free (old_to_new);
 124     }
 125   conflicts_print ();
 126   timevar_pop (TV_CONFLICTS);
 127
 128   /* Compute the parser tables.  */
 129   timevar_push (TV_ACTIONS);
 130   tables_generate ();
 131   timevar_pop (TV_ACTIONS);
 132
 133   grammar_rules_useless_report
 134     (_("rule useless in parser due to conflicts"));
 135
 136   /* Output file names. */
 137   compute_output_file_names ();
 138
 139   /* Output the detailed report on the grammar.  */
 140   if (report_flag)
 141     {
 142       timevar_push (TV_REPORT);
 143       print_results ();
 144       timevar_pop (TV_REPORT);
 145     }
 146
 147   /* Output the graph.  */
 148   if (graph_flag)
 149     {
 150       timevar_push (TV_GRAPH);
 151       print_graph ();
 152       timevar_pop (TV_GRAPH);
 153     }
 154
 155   /* Output xml.  */
 156   if (xml_flag)
 157     {
 158       timevar_push (TV_XML);
 159       print_xml ();
 160       timevar_pop (TV_XML);
 161     }
 162
 163   /* Stop if there were errors, to avoid trashing previous output
 164      files.  */
 165   if (complaint_issued)
 166     goto finish;
 167
 168   /* Lookahead tokens are no longer needed. */
 169   timevar_push (TV_FREE);
 170   lalr_free ();
 171   timevar_pop (TV_FREE);
 172
 173   /* Output the tables and the parser to ftable.  In file output.  */
 174   timevar_push (TV_PARSER);
 175   output ();
 176   timevar_pop (TV_PARSER);
 177
 178   timevar_push (TV_FREE);
 179   nullable_free ();
 180   derives_free ();
 181   tables_free ();
 182   states_free ();
 183   reduce_free ();
 184   conflicts_free ();
 185   grammar_free ();
 186   output_file_names_free ();
 187
 188   /* The scanner memory cannot be released right after parsing, as it
 189      contains things such as user actions, prologue, epilogue etc.  */
 190   gram_scanner_free ();
 191   muscle_free ();
 192   uniqstrs_free ();
 193   code_scanner_free ();
 194   skel_scanner_free ();
 195   quotearg_free ();
 196   timevar_pop (TV_FREE);
 197
 198   if (trace_flag & trace_bitsets)
 199     bitset_stats_dump (stderr);
 200
 201  finish:
 202
 203   /* Stop timing and print the times.  */
 204   timevar_stop (TV_TOTAL);
 205   timevar_print (stderr);
 206
 207   return complaint_issued ? EXIT_FAILURE : EXIT_SUCCESS;
 208 }