src/main.c

   1 /* Top level entry point of Bison.
   2
   3    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000-2002, 2004-2012 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 "closeout.h"
  32 #include "complain.h"
  33 #include "conflicts.h"
  34 #include "derives.h"
  35 #include "files.h"
  36 #include "getargs.h"
  37 #include "gram.h"
  38 #include "lalr.h"
  39 #include "ielr.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 "print-xml.h"
  46 #include "reader.h"
  47 #include "reduce.h"
  48 #include "scan-code.h"
  49 #include "scan-gram.h"
  50 #include "scan-skel.h"
  51 #include "symtab.h"
  52 #include "tables.h"
  53 #include "uniqstr.h"
  54
  55
  56
  57 int
  58 main (int argc, char *argv[])
  59 {
  60   program_name = argv[0];
  61   setlocale (LC_ALL, "");
  62   (void) bindtextdomain (PACKAGE, LOCALEDIR);
  63   (void) bindtextdomain ("bison-runtime", LOCALEDIR);
  64   (void) textdomain (PACKAGE);
  65
  66   atexit (close_stdout);
  67
  68   uniqstrs_new ();
  69   muscle_init ();
  70
  71   getargs (argc, argv);
  72
  73   timevar_report = trace_flag & trace_time;
  74   init_timevar ();
  75   timevar_start (TV_TOTAL);
  76
  77   if (trace_flag & trace_bitsets)
  78     bitset_stats_enable ();
  79
  80   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  81      and FATTRS.  In file reader.c.  The other parts are recorded in
  82      the grammar; see gram.h.  */
  83
  84   timevar_push (TV_READER);
  85   reader ();
  86   timevar_pop (TV_READER);
  87
  88   if (complaint_issued)
  89     goto finish;
  90
  91   /* Find useless nonterminals and productions and reduce the grammar. */
  92   timevar_push (TV_REDUCE);
  93   reduce_grammar ();
  94   timevar_pop (TV_REDUCE);
  95
  96   /* Record other info about the grammar.  In files derives and
  97      nullable.  */
  98   timevar_push (TV_SETS);
  99   derives_compute ();
 100   nullable_compute ();
 101   timevar_pop (TV_SETS);
 102
 103   /* Compute LR(0) parser states.  See state.h for more info.  */
 104   timevar_push (TV_LR0);
 105   generate_states ();
 106   timevar_pop (TV_LR0);
 107
 108   /* Add lookahead sets to parser states.  Except when LALR(1) is
 109      requested, split states to eliminate LR(1)-relative
 110      inadequacies.  */
 111   ielr ();
 112
 113   /* Find and record any conflicts: places where one token of
 114      lookahead is not enough to disambiguate the parsing.  In file
 115      conflicts.  Also resolve s/r conflicts based on precedence
 116      declarations.  */
 117   timevar_push (TV_CONFLICTS);
 118   conflicts_solve ();
 119   if (!muscle_percent_define_flag_if ("lr.keep-unreachable-states"))
 120     {
 121       state_number *old_to_new = xnmalloc (nstates, sizeof *old_to_new);
 122       state_number nstates_old = nstates;
 123       state_remove_unreachable_states (old_to_new);
 124       lalr_update_state_numbers (old_to_new, nstates_old);
 125       conflicts_update_state_numbers (old_to_new, nstates_old);
 126       free (old_to_new);
 127     }
 128   conflicts_print ();
 129   timevar_pop (TV_CONFLICTS);
 130
 131   /* Compute the parser tables.  */
 132   timevar_push (TV_ACTIONS);
 133   tables_generate ();
 134   timevar_pop (TV_ACTIONS);
 135
 136   grammar_rules_useless_report
 137     (_("rule useless in parser due to conflicts"));
 138
 139   /* Output file names. */
 140   compute_output_file_names ();
 141
 142   /* Output the detailed report on the grammar.  */
 143   if (report_flag)
 144     {
 145       timevar_push (TV_REPORT);
 146       print_results ();
 147       timevar_pop (TV_REPORT);
 148     }
 149
 150   /* Output the graph.  */
 151   if (graph_flag)
 152     {
 153       timevar_push (TV_GRAPH);
 154       print_graph ();
 155       timevar_pop (TV_GRAPH);
 156     }
 157
 158   /* Output xml.  */
 159   if (xml_flag)
 160     {
 161       timevar_push (TV_XML);
 162       print_xml ();
 163       timevar_pop (TV_XML);
 164     }
 165
 166   /* Stop if there were errors, to avoid trashing previous output
 167      files.  */
 168   if (complaint_issued)
 169     goto finish;
 170
 171   /* Lookahead tokens are no longer needed. */
 172   timevar_push (TV_FREE);
 173   lalr_free ();
 174   timevar_pop (TV_FREE);
 175
 176   /* Output the tables and the parser to ftable.  In file output.  */
 177   timevar_push (TV_PARSER);
 178   output ();
 179   timevar_pop (TV_PARSER);
 180
 181   timevar_push (TV_FREE);
 182   nullable_free ();
 183   derives_free ();
 184   tables_free ();
 185   states_free ();
 186   reduce_free ();
 187   conflicts_free ();
 188   grammar_free ();
 189   output_file_names_free ();
 190
 191   /* The scanner memory cannot be released right after parsing, as it
 192      contains things such as user actions, prologue, epilogue etc.  */
 193   gram_scanner_free ();
 194   muscle_free ();
 195   uniqstrs_free ();
 196   code_scanner_free ();
 197   skel_scanner_free ();
 198   quotearg_free ();
 199   timevar_pop (TV_FREE);
 200
 201   if (trace_flag & trace_bitsets)
 202     bitset_stats_dump (stderr);
 203
 204  finish:
 205
 206   /* Stop timing and print the times.  */
 207   timevar_stop (TV_TOTAL);
 208   timevar_print (stderr);
 209
 210   return complaint_issued ? EXIT_FAILURE : EXIT_SUCCESS;
 211 }