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
  36 /* The name this program was run with, for messages.  */
  37 char *program_name;
  38
  39 extern void berror PARAMS((const char *));
  40
  41 extern char *printable_version PARAMS ((int));
  42
  43 int
  44 main (int argc, char *argv[])
  45 {
  46   program_name = argv[0];
  47   setlocale (LC_ALL, "");
  48   bindtextdomain (PACKAGE, LOCALEDIR);
  49   textdomain (PACKAGE);
  50
  51   lineno = 0;
  52   getargs (argc, argv);
  53
  54   /* Be ready to clean up if we exit. */
  55   atexit (done);
  56
  57   open_files ();
  58
  59   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  60      and FATTRS.  In file reader.c.  The other parts are recorded in
  61      the grammar; see gram.h.  */
  62   reader ();
  63   if (complain_message_count)
  64     exit (1);
  65
  66   /* find useless nonterminals and productions and reduce the grammar.  In
  67      file reduce.c */
  68   reduce_grammar ();
  69
  70   /* record other info about the grammar.  In files derives and nullable.  */
  71   set_derives ();
  72   set_nullable ();
  73
  74   /* convert to nondeterministic finite state machine.  In file LR0.
  75      See state.h for more info.  */
  76   generate_states ();
  77
  78   /* make it deterministic.  In file lalr.  */
  79   lalr ();
  80
  81   /* Find and record any conflicts: places where one token of
  82      lookahead is not enough to disambiguate the parsing.  In file
  83      conflicts.  Also resolve s/r conflicts based on precedence
  84      declarations.  */
  85   initialize_conflicts ();
  86
  87   /* Print information about results, if requested.  */
  88   print_results ();
  89
  90   /* Output the tables and the parser to ftable.  In file output.  */
  91   output ();
  92
  93   finalize_conflicts ();
  94   free_nullable ();
  95   free_derives ();
  96
  97   exit (complain_message_count ? 1 : 0);
  98 }
  99 \f
 100 /* Return a string containing a printable version of C:
 101    either C itself, or the corresponding \DDD code.  */
 102
 103 char *
 104 printable_version (int c)
 105 {
 106   static char buf[10];
 107   if (c < ' ' || c >= '\177')
 108     sprintf (buf, "\\%o", c);
 109   else
 110     {
 111       buf[0] = c;
 112       buf[1] = '\0';
 113     }
 114   return buf;
 115 }
 116
 117 /* Abort for an internal error denoted by string S.  */
 118
 119 void
 120 berror (const char *s)
 121 {
 122   fprintf (stderr, _("%s: internal error: %s\n"), program_name, s);
 123   abort ();
 124 }