src/main.c

   1 /* Top level entry point of bison,
   2    Copyright (C) 1984, 1986, 1989 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20
  21 #include <stdio.h>
  22 #include "system.h"
  23 #include "machine.h"    /* JF for MAXSHORT */
  24
  25 extern  int lineno;
  26 extern  int verboseflag;
  27
  28 /* Nonzero means failure has been detected; don't write a parser file.  */
  29 int failure;
  30
  31 /* The name this program was run with, for messages. */
  32 char *program_name;
  33
  34 extern void getargs(), openfiles(), reader(), reduce_grammar();
  35 extern void set_derives(), set_nullable(), generate_states();
  36 extern void lalr(), initialize_conflicts(), verbose(), terse();
  37 extern void output(), done();
  38
  39
  40 /* VMS complained about using `int'.  */
  41 int
  42 main(argc, argv)
  43 int argc;
  44 char *argv[];
  45 {
  46   program_name = argv[0];
  47   failure = 0;
  48   lineno = 0;
  49   getargs(argc, argv);
  50   openfiles();
  51
  52   /* read the input.  Copy some parts of it to fguard, faction, ftable and fattrs.
  53      In file reader.c.
  54      The other parts are recorded in the grammar; see gram.h.  */
  55   reader();
  56
  57   /* find useless nonterminals and productions and reduce the grammar.  In
  58      file reduce.c */
  59   reduce_grammar();
  60
  61   /* record other info about the grammar.  In files derives and nullable.  */
  62   set_derives();
  63   set_nullable();
  64
  65   /* convert to nondeterministic finite state machine.  In file LR0.
  66      See state.h for more info.  */
  67   generate_states();
  68
  69   /* make it deterministic.  In file lalr.  */
  70   lalr();
  71
  72   /* Find and record any conflicts: places where one token of lookahead is not
  73      enough to disambiguate the parsing.  In file conflicts.
  74      Currently this does not do anything to resolve them;
  75      the trivial form of conflict resolution that exists is done in output.  */
  76   initialize_conflicts();
  77
  78   /* print information about results, if requested.  In file print. */
  79   if (verboseflag)
  80     verbose();
  81   else
  82     terse();
  83
  84   /* output the tables and the parser to ftable.  In file output. */
  85   output();
  86   done(failure);
  87 }
  88
  89 /* functions to report errors which prevent a parser from being generated */
  90
  91 void
  92 fatal(s)
  93 char *s;
  94 {
  95   extern char *infile;
  96
  97   if (infile == 0)
  98     fprintf(stderr, "fatal error: %s\n", s);
  99   else
 100     fprintf(stderr, "\"%s\", line %d: %s\n", infile, lineno, s);
 101   done(1);
 102 }
 103
 104
 105 /* JF changed to accept/deal with variable args.
 106    DO NOT change this to use varargs.  It will appear to work
 107    but will break on systems that don't have the necessary library
 108    functions.  This is the ONLY safe way to write such a function.  */
 109 /*VARARGS1*/
 110
 111 void
 112 fatals(fmt,x1,x2,x3,x4,x5,x6,x7,x8)
 113 char *fmt;
 114 {
 115   char buffer[200];
 116
 117   sprintf(buffer, fmt, x1,x2,x3,x4,x5,x6,x7,x8);
 118   fatal(buffer);
 119 }
 120
 121
 122 void
 123 toomany(s)
 124 char *s;
 125 {
 126   char buffer[200];
 127
 128         /* JF new msg */
 129   sprintf(buffer, "limit of %d exceeded, too many %s", MAXSHORT, s);
 130   fatal(buffer);
 131 }
 132
 133
 134 void
 135 berror(s)
 136 char *s;
 137 {
 138   fprintf(stderr, "internal error, %s\n", s);
 139   abort();
 140 }