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