src/main.c

   1 /* Top level entry point of Bison.
   2
   3    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000, 2001, 2002, 2004
   4    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
  24 #include "system.h"
  25
  26 #include <bitset_stats.h>
  27 #include <bitset.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 "muscle_tab.h"
  39 #include "nullable.h"
  40 #include "output.h"
  41 #include "print.h"
  42 #include "print_graph.h"
  43 #include "reader.h"
  44 #include "reduce.h"
  45 #include "symtab.h"
  46 #include "tables.h"
  47 #include "uniqstr.h"
  48
  49 /* The name this program was run with, for messages.  */
  50 char *program_name;
  51
  52
  53
  54 int
  55 main (int argc, char *argv[])
  56 {
  57   program_name = argv[0];
  58   setlocale (LC_ALL, "");
  59   (void) bindtextdomain (PACKAGE, LOCALEDIR);
  60   (void) textdomain (PACKAGE);
  61
  62   uniqstrs_new ();
  63
  64   getargs (argc, argv);
  65
  66   timevar_report = trace_flag & trace_time;
  67   init_timevar ();
  68   timevar_start (TV_TOTAL);
  69
  70   if (trace_flag & trace_bitsets)
  71     bitset_stats_enable ();
  72
  73   muscle_init ();
  74
  75   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  76      and FATTRS.  In file reader.c.  The other parts are recorded in
  77      the grammar; see gram.h.  */
  78
  79   timevar_push (TV_READER);
  80   reader ();
  81   timevar_pop (TV_READER);
  82
  83   if (complaint_issued)
  84     goto finish;
  85
  86   /* Find useless nonterminals and productions and reduce the grammar. */
  87   timevar_push (TV_REDUCE);
  88   reduce_grammar ();
  89   timevar_pop (TV_REDUCE);
  90
  91   /* Record other info about the grammar.  In files derives and
  92      nullable.  */
  93   timevar_push (TV_SETS);
  94   derives_compute ();
  95   nullable_compute ();
  96   timevar_pop (TV_SETS);
  97
  98   /* Convert to nondeterministic finite state machine.  In file LR0.
  99      See state.h for more info.  */
 100   timevar_push (TV_LR0);
 101   generate_states ();
 102   timevar_pop (TV_LR0);
 103
 104   /* make it deterministic.  In file lalr.  */
 105   timevar_push (TV_LALR);
 106   lalr ();
 107   timevar_pop (TV_LALR);
 108
 109   /* Find and record any conflicts: places where one token of
 110      look-ahead is not enough to disambiguate the parsing.  In file
 111      conflicts.  Also resolve s/r conflicts based on precedence
 112      declarations.  */
 113   timevar_push (TV_CONFLICTS);
 114   conflicts_solve ();
 115   conflicts_print ();
 116   timevar_pop (TV_CONFLICTS);
 117
 118   /* Compute the parser tables.  */
 119   timevar_push (TV_ACTIONS);
 120   tables_generate ();
 121   timevar_pop (TV_ACTIONS);
 122
 123   grammar_rules_never_reduced_report
 124     (_("rule never reduced because of conflicts"));
 125
 126   /* Output file names. */
 127   compute_output_file_names ();
 128
 129   /* Output the detailed report on the grammar.  */
 130   if (report_flag)
 131     {
 132       timevar_push (TV_REPORT);
 133       print_results ();
 134       timevar_pop (TV_REPORT);
 135     }
 136
 137   /* Output the VCG graph.  */
 138   if (graph_flag)
 139     {
 140       timevar_push (TV_GRAPH);
 141       print_graph ();
 142       timevar_pop (TV_GRAPH);
 143     }
 144
 145   /* Stop if there were errors, to avoid trashing previous output
 146      files.  */
 147   if (complaint_issued)
 148     goto finish;
 149
 150   /* Look-ahead tokens are no longer needed. */
 151   timevar_push (TV_FREE);
 152   lalr_free ();
 153   timevar_pop (TV_FREE);
 154
 155   /* Output the tables and the parser to ftable.  In file output.  */
 156   timevar_push (TV_PARSER);
 157   output ();
 158   timevar_pop (TV_PARSER);
 159
 160   timevar_push (TV_FREE);
 161   nullable_free ();
 162   derives_free ();
 163   tables_free ();
 164   states_free ();
 165   reduce_free ();
 166   conflicts_free ();
 167   grammar_free ();
 168
 169   /* The scanner memory cannot be released right after parsing, as it
 170      contains things such as user actions, prologue, epilogue etc.  */
 171   scanner_free ();
 172   muscle_free ();
 173   uniqstrs_free ();
 174   /* If using alloca.c, flush the alloca'ed memory for the benefit of
 175      people running Bison as a library in IDEs.  */
 176 #if C_ALLOCA
 177   {
 178     extern void *alloca (size_t);
 179     alloca (0);
 180   }
 181 #endif
 182   timevar_pop (TV_FREE);
 183
 184   if (trace_flag & trace_bitsets)
 185     bitset_stats_dump (stderr);
 186
 187  finish:
 188
 189   /* Stop timing and print the times.  */
 190   timevar_stop (TV_TOTAL);
 191   timevar_print (stderr);
 192
 193   return complaint_issued ? EXIT_FAILURE : EXIT_SUCCESS;
 194 }