src/main.c

   1 /* Top level entry point of bison,
   2    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000, 2001, 2002
   3    Free Software Foundation, Inc.
   4
   5    This file is part of Bison, the GNU Compiler Compiler.
   6
   7    Bison is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2, or (at your option)
  10    any later version.
  11
  12    Bison is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with Bison; see the file COPYING.  If not, write to
  19    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22
  23 #include "system.h"
  24 #include "bitset_stats.h"
  25 #include "bitset.h"
  26 #include "getargs.h"
  27 #include "symtab.h"
  28 #include "gram.h"
  29 #include "files.h"
  30 #include "complain.h"
  31 #include "derives.h"
  32 #include "tables.h"
  33 #include "output.h"
  34 #include "reader.h"
  35 #include "lalr.h"
  36 #include "reduce.h"
  37 #include "nullable.h"
  38 #include "print.h"
  39 #include "LR0.h"
  40 #include "conflicts.h"
  41 #include "print_graph.h"
  42 #include "muscle_tab.h"
  43
  44 /* The name this program was run with, for messages.  */
  45 char *program_name;
  46
  47
  48
  49 int
  50 main (int argc, char *argv[])
  51 {
  52   program_name = argv[0];
  53   setlocale (LC_ALL, "");
  54   (void) bindtextdomain (PACKAGE, LOCALEDIR);
  55   (void) textdomain (PACKAGE);
  56
  57   getargs (argc, argv);
  58
  59   time_report = trace_flag & trace_time;
  60   init_timevar ();
  61   timevar_start (TV_TOTAL);
  62
  63   if (trace_flag & trace_bitsets)
  64     bitset_stats_enable ();
  65
  66   muscle_init ();
  67
  68   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  69      and FATTRS.  In file reader.c.  The other parts are recorded in
  70      the grammar; see gram.h.  */
  71
  72   timevar_push (TV_READER);
  73   reader ();
  74   timevar_pop (TV_READER);
  75
  76   if (complaint_issued)
  77     exit (EXIT_FAILURE);
  78
  79   /* Find useless nonterminals and productions and reduce the grammar. */
  80   timevar_push (TV_REDUCE);
  81   reduce_grammar ();
  82   timevar_pop (TV_REDUCE);
  83
  84   /* Record other info about the grammar.  In files derives and
  85      nullable.  */
  86   timevar_push (TV_SETS);
  87   derives_compute ();
  88   nullable_compute ();
  89   timevar_pop (TV_SETS);
  90
  91   /* Convert to nondeterministic finite state machine.  In file LR0.
  92      See state.h for more info.  */
  93   timevar_push (TV_LR0);
  94   generate_states ();
  95   timevar_pop (TV_LR0);
  96
  97   /* make it deterministic.  In file lalr.  */
  98   timevar_push (TV_LALR);
  99   lalr ();
 100   timevar_pop (TV_LALR);
 101
 102   /* Find and record any conflicts: places where one token of
 103      lookahead is not enough to disambiguate the parsing.  In file
 104      conflicts.  Also resolve s/r conflicts based on precedence
 105      declarations.  */
 106   timevar_push (TV_CONFLICTS);
 107   conflicts_solve ();
 108   conflicts_print ();
 109   timevar_pop (TV_CONFLICTS);
 110
 111   /* Compute the parser tables.  */
 112   timevar_push (TV_ACTIONS);
 113   tables_generate ();
 114   timevar_pop (TV_ACTIONS);
 115
 116   grammar_rules_never_reduced_report
 117     (_("rule never reduced because of conflicts"));
 118
 119   /* Output file names. */
 120   compute_output_file_names ();
 121
 122   /* Output the detailed report on the grammar.  */
 123   if (report_flag)
 124     {
 125       timevar_push (TV_REPORT);
 126       print_results ();
 127       timevar_pop (TV_REPORT);
 128     }
 129
 130   /* Output the VCG graph.  */
 131   if (graph_flag)
 132     {
 133       timevar_push (TV_GRAPH);
 134       print_graph ();
 135       timevar_pop (TV_GRAPH);
 136     }
 137
 138   /* Stop if there were errors, to avoid trashing previous output
 139      files.  */
 140   if (complaint_issued)
 141     exit (EXIT_FAILURE);
 142
 143   /* Lookaheads are no longer needed. */
 144   timevar_push (TV_FREE);
 145   lalr_free ();
 146   timevar_pop (TV_FREE);
 147
 148   /* Output the tables and the parser to ftable.  In file output.  */
 149   timevar_push (TV_PARSER);
 150   output ();
 151   timevar_pop (TV_PARSER);
 152
 153   timevar_push (TV_FREE);
 154   nullable_free ();
 155   derives_free ();
 156   tables_free ();
 157   states_free ();
 158   reduce_free ();
 159   conflicts_free ();
 160   grammar_free ();
 161
 162   /* The scanner memory cannot be released right after parsing, as it
 163      contains things such as user actions, prologue, epilogue etc.  */
 164   scanner_free ();
 165   muscle_free ();
 166   /* If using alloca.c, flush the alloca'ed memory for the benefit of
 167      people running Bison as a library in IDEs.  */
 168 #if C_ALLOCA
 169   alloca (0);
 170 #endif
 171   timevar_pop (TV_FREE);
 172
 173   if (trace_flag & trace_bitsets)
 174     bitset_stats_dump (stderr);
 175
 176   /* Stop timing and print the times.  */
 177   timevar_stop (TV_TOTAL);
 178   timevar_print (stderr);
 179
 180   /* Some ancient SunOS versions exit (0) if main returns, so use
 181      `exit' to exit with nonzero status.  */
 182   if (complaint_issued)
 183     exit (EXIT_FAILURE);
 184
 185   return EXIT_SUCCESS;
 186 }