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