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