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
  28 #if 0                           /* XXX currently unused.  */
  29 /* Nonzero means failure has been detected; don't write a parser file.  */
  30 static int failure;
  31 #endif
  32
  33 /* The name this program was run with, for messages.  */
  34 char *program_name;
  35
  36 extern char *printable_version PARAMS((int));
  37 extern void berror PARAMS((const char *));
  38
  39 extern void openfiles PARAMS((void));
  40 extern void reader PARAMS((void));
  41 extern void reduce_grammar PARAMS((void));
  42 extern void set_derives PARAMS((void));
  43 extern void free_derives PARAMS((void));
  44 extern void set_nullable PARAMS((void));
  45 extern void free_nullable PARAMS((void));
  46 extern void generate_states PARAMS((void));
  47 extern void lalr PARAMS((void));
  48 extern void initialize_conflicts PARAMS((void));
  49 extern void finalize_conflicts PARAMS((void));
  50 extern void verbose PARAMS((void));
  51 extern void terse PARAMS((void));
  52 extern void output 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 and fattrs.
  74      In file reader.c.
  75      The other parts are recorded in 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 lookahead is not
  96      enough to disambiguate the parsing.  In file conflicts.
  97      Also resolve s/r conflicts based on precedence declarations.  */
  98   initialize_conflicts();
  99
 100   /* print information about results, if requested.  In file print. */
 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 /* functions to report errors which prevent a parser from being generated */
 117
 118
 119 /* Return a string containing a printable version of C:
 120    either C itself, or the corresponding \DDD code.  */
 121
 122 char *
 123 printable_version (int c)
 124 {
 125   static char buf[10];
 126   if (c < ' ' || c >= '\177')
 127     sprintf(buf, "\\%o", c);
 128   else
 129     {
 130       buf[0] = c;
 131       buf[1] = '\0';
 132     }
 133   return buf;
 134 }
 135
 136 /* Abort for an internal error denoted by string S.  */
 137
 138 void
 139 berror (const char *s)
 140 {
 141   fprintf (stderr, _("%s: internal error: %s\n"), program_name, s);
 142   abort();
 143 }