diff options
Diffstat (limited to 'src/extract-magic')
| -rw-r--r-- | src/extract-magic | 162 |
1 files changed, 162 insertions, 0 deletions
diff --git a/src/extract-magic b/src/extract-magic new file mode 100644 index 0000000..8d135c3 --- /dev/null +++ b/src/extract-magic @@ -0,0 +1,162 @@ +#!/usr/bin/perl -w +# Derive #define directives from specially formatted 'case ...:' statements. + +# Copyright (C) 2003-2022 Free Software Foundation, Inc. + +# This program is free software: you can redistribute it and/or modify +# it under the terms of the GNU General Public License as published by +# the Free Software Foundation, either version 3 of the License, or +# (at your option) any later version. + +# This program is distributed in the hope that it will be useful, +# but WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +# GNU General Public License for more details. + +# You should have received a copy of the GNU General Public License +# along with this program. If not, see <https://www.gnu.org/licenses/>. + +use strict; + +use Getopt::Long; + +(my $VERSION = '$Revision: 1.5 $ ') =~ tr/[0-9].//cd; +(my $ME = $0) =~ s|.*/||; + +END +{ + # Nobody ever checks the status of print()s. That's okay, because + # if any do fail, we're guaranteed to get an indicator when we close() + # the filehandle. + # + # Close stdout now, and if there were no errors, return happy status. + # If stdout has already been closed by the script, though, do nothing. + defined fileno STDOUT + or return; + close STDOUT + and return; + + # Errors closing stdout. Indicate that, and hope stderr is OK. + warn "$ME: closing standard output: $!\n"; + + # Don't be so arrogant as to assume that we're the first END handler + # defined, and thus the last one invoked. There may be others yet + # to come. $? will be passed on to them, and to the final _exit(). + # + # If it isn't already an error, make it one (and if it _is_ an error, + # preserve the value: it might be important). + $? ||= 1; +} + +sub usage ($) +{ + my ($exit_code) = @_; + my $STREAM = ($exit_code == 0 ? *STDOUT : *STDERR); + if ($exit_code != 0) + { + print $STREAM "Try '$ME --help' for more information.\n"; + } + else + { + print $STREAM <<EOF; +Usage: $ME [OPTIONS] FILE + +FIXME: describe + +OPTIONS: + + There are two modes of operation, the default, which is to emit + #define directives derived from specially formatted 'case' statements, + and that with --local, which is to emit a static inline function + mapping S_MAGIC_* values to 1, 0, -1, corresponding to known-local, + known-remote/distributed/network and unknown, respectively. + + --local emit an is_local_fs_type function + --help display this help and exit + --version output version information and exit + +EOF + } + exit $exit_code; +} + +{ + # The default is to print S_MAGIC_* definitions. + my $emit_magic = 1; + + GetOptions + ( + local => sub { $emit_magic = 0 }, + help => sub { usage 0 }, + version => sub { print "$ME version $VERSION\n"; exit }, + ) or usage 1; + + my $fail = 0; + + @ARGV < 1 + and (warn "$ME: missing FILE arguments\n"), $fail = 1; + 1 < @ARGV + and (warn "$ME: too many arguments\n"), $fail = 1; + $fail + and usage 1; + + my $file = $ARGV[0]; + + open FH, $file + or die "$ME: can't open '$file' for reading: $!\n"; + + # For each line like this: + # case S_MAGIC_ROMFS: /* 0x7275 */ + # emit one like this: + # # define S_MAGIC_ROMFS 0x7275 + # Fail if there is a 'case S_MAGIC_.*' line without + # a properly formed comment. + + my $map_comment = <<EOF; +/* Map each S_MAGIC_* value to 1, 0 or -1. + 1 if it is known to be a remote file system type, + 0 if it is known to be a local file system type, or -1 otherwise. */ +EOF + my $magic_comment = <<EOF; +/* Define the magic numbers as given by statfs(2). + Please send additions to bug-coreutils\@gnu.org and meskes\@debian.org. + This file is generated automatically from $file. */ +EOF + print $emit_magic ? $magic_comment : $map_comment; + + $emit_magic + and print "\n#if defined __linux__ || defined __ANDROID__\n"; + $emit_magic + or print "static inline int\n" + . "is_local_fs_type (unsigned long int magic)\n" + . "{\n switch (magic)\n {\n"; + + while (defined (my $line = <FH>)) + { + $line =~ /^[ \t]+case S_MAGIC_/ + or next; + $line =~ + m!^[ \t]+case (S_MAGIC_\w+): /\* (0x[0-9A-Fa-f]+) (local|remote) \*/! + or (warn "$ME:$file:$.: malformed case S_MAGIC_... line"), + $fail = 1, next; + my $name = $1; + my $magic = $2; + my $local = $3 eq 'local' ? 1 : 0; + print $emit_magic + ? "# define $name $magic\n" + : " case $name: return $local;\n"; + } + + $emit_magic + and print <<\EOF; +#elif defined __GNU__ +# include <hurd/hurd_types.h> +#endif +EOF + $emit_magic + or printf " default: return -1;\n }\n}\n"; + + close FH; + + exit $fail; +} |