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
  30 #if 0                           /* XXX currently unused.  */
  31 /* Nonzero means failure has been detected; don't write a parser file.  */
  32 static int failure;
  33 #endif
  34
  35 /* The name this program was run with, for messages.  */
  36 char *program_name;
  37
  38 extern void berror PARAMS((const char *));
  39
  40 extern char *printable_version PARAMS ((int));
  41
  42 extern void openfiles PARAMS ((void));
  43 extern void reader PARAMS ((void));
  44 extern void reduce_grammar PARAMS ((void));
  45 extern void set_nullable PARAMS ((void));
  46 extern void free_nullable PARAMS ((void));
  47 extern void generate_states PARAMS ((void));
  48 extern void lalr PARAMS ((void));
  49 extern void initialize_conflicts PARAMS ((void));
  50 extern void finalize_conflicts PARAMS ((void));
  51 extern void verbose PARAMS ((void));
  52 extern void terse PARAMS ((void));
  53
  54
  55 /* VMS complained about using `int'.  */
  56
  57 int
  58 main (int argc, char *argv[])
  59 {
  60   program_name = argv[0];
  61   setlocale (LC_ALL, "");
  62   bindtextdomain (PACKAGE, LOCALEDIR);
  63   textdomain (PACKAGE);
  64
  65   lineno = 0;
  66   getargs (argc, argv);
  67
  68   /* Be ready to clean up if we exit. */
  69   atexit (done);
  70
  71   openfiles ();
  72
  73   /* Read the input.  Copy some parts of it to FGUARD, FACTION, FTABLE
  74      and FATTRS.  In file reader.c.  The other parts are recorded in
  75      the grammar; see gram.h.  */
  76   reader ();
  77   if (complain_message_count)
  78     exit (1);
  79
  80   /* find useless nonterminals and productions and reduce the grammar.  In
  81      file reduce.c */
  82   reduce_grammar ();
  83
  84   /* record other info about the grammar.  In files derives and nullable.  */
  85   set_derives ();
  86   set_nullable ();
  87
  88   /* convert to nondeterministic finite state machine.  In file LR0.
  89      See state.h for more info.  */
  90   generate_states ();
  91
  92   /* make it deterministic.  In file lalr.  */
  93   lalr ();
  94
  95   /* Find and record any conflicts: places where one token of
  96      lookahead is not enough to disambiguate the parsing.  In file
  97      conflicts.  Also resolve s/r conflicts based on precedence
  98      declarations.  */
  99   initialize_conflicts ();
 100
 101   /* Print information about results, if requested.  In file print.
 102      */
 103   if (verboseflag)
 104     verbose ();
 105   else
 106     terse ();
 107
 108   /* Output the tables and the parser to ftable.  In file output.  */
 109   output ();
 110
 111   finalize_conflicts ();
 112   free_nullable ();
 113   free_derives ();
 114
 115   exit (complain_message_count ? 1 : 0);
 116 }
 117 \f
 118 /* Return a string containing a printable version of C:
 119    either C itself, or the corresponding \DDD code.  */
 120
 121 char *
 122 printable_version (int c)
 123 {
 124   static char buf[10];
 125   if (c < ' ' || c >= '\177')
 126     sprintf (buf, "\\%o", c);
 127   else
 128     {
 129       buf[0] = c;
 130       buf[1] = '\0';
 131     }
 132   return buf;
 133 }
 134
 135 /* Abort for an internal error denoted by string S.  */
 136
 137 void
 138 berror (const char *s)
 139 {
 140   fprintf (stderr, _("%s: internal error: %s\n"), program_name, s);
 141   abort ();
 142 }