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 /* Nonzero means failure has been detected; don't write a parser file.  */
  31 int failure;
  32
  33 /* The name this program was run with, for messages.  */
  34 char *program_name;
  35
  36 char *printable_version PARAMS((int));
  37 void toomany PARAMS((char *));
  38 void berror PARAMS((char *));
  39
  40 extern void getargs PARAMS((int, char *[]));
  41 extern void openfiles PARAMS((void));
  42 extern void reader PARAMS((void));
  43 extern void reduce_grammar PARAMS((void));
  44 extern void set_derives PARAMS((void));
  45 extern void set_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 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 and fattrs.
  73      In file reader.c.
  74      The other parts are recorded in 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 lookahead is not
  95      enough to disambiguate the parsing.  In file conflicts.
  96      Also resolve s/r conflicts based on precedence declarations.  */
  97   initialize_conflicts();
  98
  99   /* print information about results, if requested.  In file print. */
 100   if (verboseflag)
 101     verbose();
 102   else
 103     terse();
 104
 105   /* output the tables and the parser to ftable.  In file output. */
 106   output();
 107   done ();
 108
 109   exit (complain_message_count ? 1 : 0);
 110 }
 111 \f
 112 /* functions to report errors which prevent a parser from being generated */
 113
 114
 115 /* Return a string containing a printable version of C:
 116    either C itself, or the corresponding \DDD code.  */
 117
 118 char *
 119 printable_version (int c)
 120 {
 121   static char buf[10];
 122   if (c < ' ' || c >= '\177')
 123     sprintf(buf, "\\%o", c);
 124   else
 125     {
 126       buf[0] = c;
 127       buf[1] = '\0';
 128     }
 129   return buf;
 130 }
 131
 132 /* Abort for an internal error denoted by string S.  */
 133
 134 void
 135 berror (char *s)
 136 {
 137   fprintf (stderr, _("%s: internal error: %s\n"), program_name, s);
 138   abort();
 139 }