src/main.c

   1 /* Top level entry point of bison,
   2    Copyright (C) 1984, 1986, 1989, 1992, 1995, 2000 Free Software Foundation, Inc.
   3
   4    This file is part of Bison, the GNU Compiler Compiler.
   5
   6    Bison is free software; you can redistribute it and/or modify
   7    it under the terms of the GNU General Public License as published by
   8    the Free Software Foundation; either version 2, or (at your option)
   9    any later version.
  10
  11    Bison is distributed in the hope that it will be useful,
  12    but WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14    GNU General Public License for more details.
  15
  16    You should have received a copy of the GNU General Public License
  17    along with Bison; see the file COPYING.  If not, write to
  18    the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19    Boston, MA 02111-1307, USA.  */
  20
  21
  22 #include <stdio.h>
  23 #include "system.h"
  24 #include "machine.h"    /* for MAXSHORT */
  25 #include "files.h"
  26 #include "complain.h"
  27
  28 extern  int verboseflag;
  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 char *printable_version PARAMS((int));
  39 extern void berror PARAMS((const char *));
  40
  41 extern void getargs PARAMS((int, char *[]));
  42 extern void openfiles PARAMS((void));
  43 extern void reader PARAMS((void));
  44 extern void reduce_grammar PARAMS((void));
  45 extern void set_derives PARAMS((void));
  46 extern void free_derives PARAMS((void));
  47 extern void set_nullable PARAMS((void));
  48 extern void generate_states PARAMS((void));
  49 extern void lalr PARAMS((void));
  50 extern void initialize_conflicts PARAMS((void));
  51 extern void finalize_conflicts PARAMS((void));
  52 extern void verbose PARAMS((void));
  53 extern void terse PARAMS((void));
  54 extern void output PARAMS((void));
  55
  56
  57 /* VMS complained about using `int'.  */
  58
  59 int
  60 main (int argc, char *argv[])
  61 {
  62   program_name = argv[0];
  63   setlocale (LC_ALL, "");
  64   bindtextdomain (PACKAGE, LOCALEDIR);
  65   textdomain (PACKAGE);
  66
  67   lineno = 0;
  68   getargs(argc, argv);
  69
  70   /* Be ready to clean up if we exit.*/
  71   atexit (done);
  72
  73   openfiles();
  74
  75   /* read the input.  Copy some parts of it to fguard, faction, ftable and fattrs.
  76      In file reader.c.
  77      The other parts are recorded in the grammar; see gram.h.  */
  78   reader ();
  79   if (complain_message_count)
  80     exit (1);
  81
  82   /* find useless nonterminals and productions and reduce the grammar.  In
  83      file reduce.c */
  84   reduce_grammar();
  85
  86   /* record other info about the grammar.  In files derives and nullable.  */
  87   set_derives();
  88   set_nullable();
  89
  90   /* convert to nondeterministic finite state machine.  In file LR0.
  91      See state.h for more info.  */
  92   generate_states();
  93
  94   /* make it deterministic.  In file lalr.  */
  95   lalr();
  96
  97   /* Find and record any conflicts: places where one token of lookahead is not
  98      enough to disambiguate the parsing.  In file conflicts.
  99      Also resolve s/r conflicts based on precedence declarations.  */
 100   initialize_conflicts();
 101
 102   /* print information about results, if requested.  In file print. */
 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_derives();
 113
 114   exit (complain_message_count ? 1 : 0);
 115 }
 116 \f
 117 /* functions to report errors which prevent a parser from being generated */
 118
 119
 120 /* Return a string containing a printable version of C:
 121    either C itself, or the corresponding \DDD code.  */
 122
 123 char *
 124 printable_version (int c)
 125 {
 126   static char buf[10];
 127   if (c < ' ' || c >= '\177')
 128     sprintf(buf, "\\%o", c);
 129   else
 130     {
 131       buf[0] = c;
 132       buf[1] = '\0';
 133     }
 134   return buf;
 135 }
 136
 137 /* Abort for an internal error denoted by string S.  */
 138
 139 void
 140 berror (const char *s)
 141 {
 142   fprintf (stderr, _("%s: internal error: %s\n"), program_name, s);
 143   abort();
 144 }