src/main.c

   1 /* Top level entry point of bison,
   2    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000
   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 "getargs.h"
  25 #include "files.h"
  26 #include "complain.h"
  27 #include "derives.h"
  28 #include "output.h"
  29 #include "reader.h"
  30 #include "lalr.h"
  31 #include "reduce.h"
  32 #include "nullable.h"
  33 #include "print.h"
  34 #include "LR0.h"
  35 #include "conflicts.h"
  36
  37 /* The name this program was run with, for messages.  */
  38 char *program_name;
  39
  40 extern void berror PARAMS((const char *));
  41
  42 int
  43 main (int argc, char *argv[])
  44 {
  45   program_name = argv[0];
  46   setlocale (LC_ALL, "");
  47   bindtextdomain (PACKAGE, LOCALEDIR);
  48   textdomain (PACKAGE);
  49
  50   lineno = 0;
  51   getargs (argc, argv);
  52
  53   /* Be ready to clean up if we exit. */
  54   atexit (done);
  55
  56   open_files ();
  57
  58   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  59      and FATTRS.  In file reader.c.  The other parts are recorded in
  60      the grammar; see gram.h.  */
  61   reader ();
  62   if (complain_message_count)
  63     exit (1);
  64
  65   /* find useless nonterminals and productions and reduce the grammar.  In
  66      file reduce.c */
  67   reduce_grammar ();
  68
  69   /* record other info about the grammar.  In files derives and nullable.  */
  70   set_derives ();
  71   set_nullable ();
  72
  73   /* convert to nondeterministic finite state machine.  In file LR0.
  74      See state.h for more info.  */
  75   generate_states ();
  76
  77   /* make it deterministic.  In file lalr.  */
  78   lalr ();
  79
  80   /* Find and record any conflicts: places where one token of
  81      lookahead is not enough to disambiguate the parsing.  In file
  82      conflicts.  Also resolve s/r conflicts based on precedence
  83      declarations.  */
  84   initialize_conflicts ();
  85
  86   /* Print information about results, if requested.  */
  87   print_results ();
  88
  89   /* Output the tables and the parser to ftable.  In file output.  */
  90   output ();
  91
  92   finalize_conflicts ();
  93   free_nullable ();
  94   free_derives ();
  95
  96   exit (complain_message_count ? 1 : 0);
  97 }
  98 \f
  99 /* Abort for an internal error denoted by string S.  */
 100
 101 void
 102 berror (const char *s)
 103 {
 104   fprintf (stderr, _("%s: internal error: %s\n"), program_name, s);
 105   abort ();
 106 }