src/main.c

   1 /* Top level entry point of bison,
   2    Copyright 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 "output.h"
  33 #include "reader.h"
  34 #include "lalr.h"
  35 #include "reduce.h"
  36 #include "nullable.h"
  37 #include "print.h"
  38 #include "LR0.h"
  39 #include "conflicts.h"
  40 #include "print_graph.h"
  41 #include "muscle_tab.h"
  42
  43 /* The name this program was run with, for messages.  */
  44 char *program_name;
  45
  46 int
  47 main (int argc, char *argv[])
  48 {
  49   program_name = argv[0];
  50   setlocale (LC_ALL, "");
  51   bindtextdomain (PACKAGE, LOCALEDIR);
  52   textdomain (PACKAGE);
  53
  54   lineno = 0;
  55   getargs (argc, argv);
  56
  57   if (trace_flag)
  58     bitset_stats_enable ();
  59
  60   muscle_init ();
  61
  62   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  63      and FATTRS.  In file reader.c.  The other parts are recorded in
  64      the grammar; see gram.h.  */
  65   reader ();
  66   if (complain_message_count)
  67     exit (1);
  68
  69   /* Find useless nonterminals and productions and reduce the grammar. */
  70   reduce_grammar ();
  71
  72   /* Record other info about the grammar.  In files derives and
  73      nullable.  */
  74   set_derives ();
  75   set_nullable ();
  76
  77   /* Convert to nondeterministic finite state machine.  In file LR0.
  78      See state.h for more info.  */
  79   generate_states ();
  80
  81   /* make it deterministic.  In file lalr.  */
  82   lalr ();
  83
  84   /* Find and record any conflicts: places where one token of
  85      lookahead is not enough to disambiguate the parsing.  In file
  86      conflicts.  Also resolve s/r conflicts based on precedence
  87      declarations.  */
  88   conflicts_solve ();
  89   conflicts_print ();
  90
  91   /* Output file names. */
  92   compute_output_file_names ();
  93
  94   /* Output the detailed report on the grammar.  */
  95   if (report_flag)
  96     print_results ();
  97
  98   /* Stop if there were errors, to avoid trashing previous output
  99      files.  */
 100   if (complain_message_count)
 101     exit (1);
 102
 103   /* Output the VCG graph.  */
 104   if (graph_flag)
 105     print_graph ();
 106
 107   /* Output the tables and the parser to ftable.  In file output.  */
 108   output ();
 109
 110   states_free ();
 111   reduce_free ();
 112   conflicts_free ();
 113   free_nullable ();
 114   free_derives ();
 115   grammar_free ();
 116
 117   /* The scanner memory cannot be released right after parsing, as it
 118      contains things such as user actions, prologue, epilogue etc.  */
 119   scanner_free ();
 120   muscle_free ();
 121   /* If using alloca.c, flush the alloca'ed memory for the benefit of
 122      people running Bison as a library in IDEs.  */
 123 #if C_ALLOCA
 124     alloca (0);
 125 #endif
 126
 127     if (trace_flag)
 128       bitset_stats_dump (stderr);
 129
 130   return complain_message_count ? EXIT_FAILURE : EXIT_SUCCESS;
 131 }