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      Also resolve s/r conflicts based on precedence declarations.  */
  75   initialize_conflicts();
  76
  77   /* print information about results, if requested.  In file print. */
  78   if (verboseflag)
  79     verbose();
  80   else
  81     terse();
  82
  83   /* output the tables and the parser to ftable.  In file output. */
  84   output();
  85   done(failure);
  86 }
  87
  88 /* functions to report errors which prevent a parser from being generated */
  89
  90 void
  91 fatal(s)
  92 char *s;
  93 {
  94   extern char *infile;
  95
  96   if (infile == 0)
  97     fprintf(stderr, "fatal error: %s\n", s);
  98   else
  99     fprintf(stderr, "\"%s\", line %d: %s\n", infile, lineno, s);
 100   done(1);
 101 }
 102
 103
 104 /* JF changed to accept/deal with variable args.
 105    DO NOT change this to use varargs.  It will appear to work
 106    but will break on systems that don't have the necessary library
 107    functions.  This is the ONLY safe way to write such a function.  */
 108 /*VARARGS1*/
 109
 110 void
 111 fatals(fmt,x1,x2,x3,x4,x5,x6,x7,x8)
 112 char *fmt;
 113 {
 114   char buffer[200];
 115
 116   sprintf(buffer, fmt, x1,x2,x3,x4,x5,x6,x7,x8);
 117   fatal(buffer);
 118 }
 119
 120
 121 void
 122 toomany(s)
 123 char *s;
 124 {
 125   char buffer[200];
 126
 127         /* JF new msg */
 128   sprintf(buffer, "limit of %d exceeded, too many %s", MAXSHORT, s);
 129   fatal(buffer);
 130 }
 131
 132
 133 void
 134 berror(s)
 135 char *s;
 136 {
 137   fprintf(stderr, "internal error, %s\n", s);
 138   abort();
 139 }