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 free_nullable PARAMS((void));
  49 extern void generate_states PARAMS((void));
  50 extern void lalr PARAMS((void));
  51 extern void initialize_conflicts PARAMS((void));
  52 extern void finalize_conflicts PARAMS((void));
  53 extern void verbose PARAMS((void));
  54 extern void terse PARAMS((void));
  55 extern void output PARAMS((void));
  56
  57
  58 /* VMS complained about using `int'.  */
  59
  60 int
  61 main (int argc, char *argv[])
  62 {
  63   program_name = argv[0];
  64   setlocale (LC_ALL, "");
  65   bindtextdomain (PACKAGE, LOCALEDIR);
  66   textdomain (PACKAGE);
  67
  68   lineno = 0;
  69   getargs(argc, argv);
  70
  71   /* Be ready to clean up if we exit.*/
  72   atexit (done);
  73
  74   openfiles();
  75
  76   /* read the input.  Copy some parts of it to fguard, faction, ftable and fattrs.
  77      In file reader.c.
  78      The other parts are recorded in the grammar; see gram.h.  */
  79   reader ();
  80   if (complain_message_count)
  81     exit (1);
  82
  83   /* find useless nonterminals and productions and reduce the grammar.  In
  84      file reduce.c */
  85   reduce_grammar();
  86
  87   /* record other info about the grammar.  In files derives and nullable.  */
  88   set_derives();
  89   set_nullable();
  90
  91   /* convert to nondeterministic finite state machine.  In file LR0.
  92      See state.h for more info.  */
  93   generate_states();
  94
  95   /* make it deterministic.  In file lalr.  */
  96   lalr();
  97
  98   /* Find and record any conflicts: places where one token of lookahead is not
  99      enough to disambiguate the parsing.  In file conflicts.
 100      Also resolve s/r conflicts based on precedence declarations.  */
 101   initialize_conflicts();
 102
 103   /* print information about results, if requested.  In file print. */
 104   if (verboseflag)
 105     verbose();
 106   else
 107     terse();
 108
 109   /* output the tables and the parser to ftable.  In file output. */
 110   output();
 111
 112   finalize_conflicts();
 113   free_nullable();
 114   free_derives();
 115
 116   exit (complain_message_count ? 1 : 0);
 117 }
 118 \f
 119 /* functions to report errors which prevent a parser from being generated */
 120
 121
 122 /* Return a string containing a printable version of C:
 123    either C itself, or the corresponding \DDD code.  */
 124
 125 char *
 126 printable_version (int c)
 127 {
 128   static char buf[10];
 129   if (c < ' ' || c >= '\177')
 130     sprintf(buf, "\\%o", c);
 131   else
 132     {
 133       buf[0] = c;
 134       buf[1] = '\0';
 135     }
 136   return buf;
 137 }
 138
 139 /* Abort for an internal error denoted by string S.  */
 140
 141 void
 142 berror (const char *s)
 143 {
 144   fprintf (stderr, _("%s: internal error: %s\n"), program_name, s);
 145   abort();
 146 }