summaryrefslogtreecommitdiffstats
path: root/src/extract-magic
diff options
context:
space:
mode:
Diffstat (limited to 'src/extract-magic')
-rw-r--r--src/extract-magic162
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;
+}