#!/usr/bin/perl -w

=head1 NAME

dh_autoreconf - Call autoreconf -f -i and keep track of the changed files.

=cut

use strict;
use Debian::Debhelper::Dh_Lib;

=head1 SYNOPSIS

B<dh_autoreconf> [S<I<debhelper options>>] [B<-X>I<item>] [B<--mode=>I<mode>]
[S<I<program> B<--> I<params>>]

=head1 DESCRIPTION

dh_autoreconf is responsible for calling autoreconf and creating the files
debian/autoreconf.before and debian/autoreconf.after which contain checksums
of all files before/after the build. It is complemented by dh_autoreconf_clean
which creates a list of all changed and added files and removes them.

Please note that dh_autoreconf can only be run once. Thus, if you need to
run multiple commands, use a script or similar. An example is given in
L<dh-autoreconf(7)>.

=head1 FILES

=over 4

=item debian/autoreconf

This file can contain a list of directories. If present, dh_autoreconf will
only scan the given directories for changes. If no special command is given
to dh_autoreconf, it will also forward the directory list to autoreconf
which causes it to be run only on those sub directories.

=back

=head1 OPTIONS

=over 4

=item B<-X>I<item> B<--exclude=>I<item>

Exclude files that contain "item" anywhere in their filename from being
checked for changes. This means that those files won't be deleted by
C<dh_autoreconf_clean> even if there are changes. You may use this option
multiple times to build up a list of things to exclude.

Starting with version 3, the directories of common version control systems
such as cvs, git, hg, svn, and bzr are excluded automatically.

=item B<--mode=>I<mode>

Change the way in which modifications to files are detected. The default mode
is I<md5> for using MD5 checksums, but there is also I<timesize> for using
the time of the last modification and the file size.

=item B<--as-needed>

Enable support for -Wl,--as-needed in all ltmain.sh files identical to
the one of the libtool package. This only works in the MD5 mode (the
default one). The changes are reverted in dh_autoreconf_clean. You should
not prevent LIBTOOLIZE from running with this, as it only works correctly
with libtoolize running.

=item I<program> B<--> I<params>

Run the program given by I<program> with the arguments given by I<params>
instead of autoreconf -f -i. If you need to run multiple commands, put them in
a script and pass the script instead (or add a target to debian/rules).

=back

=head1 ENVIRONMENT

For each tool executed by L<autoreconf(1)>, one can export a variable with
the uppercase name of the tool to the specific program which shall be run,
including B<true> to prevent the tool in question from being run. The following
example shows the beginning of a debian/rules for a package where automake
1.10 shall be run instead of the default automake version and libtoolize
shall not be run:

    #!/usr/bin/make -f
    export AUTOMAKE = automake1.10
    export LIBTOOLIZE = true

=cut

init(options => { "mode=s" => \$dh{MODE},
                  "as-needed" => \$dh{AS_NEEDED}});

my $exception;
my @directories;
my $find_options='! -ipath "./debian/*" -a ';
my @exclude_default = ("'*/.git/*'", "'*/.hg/*'", "'*/.bzr/*'", "'*/.svn/*'",
                       "'*/CVS/*'");

$find_options .= ("! \\( -path " . join(" -o -path ", @exclude_default) .
                      " \\) -a ");

if (defined($dh{EXCLUDE_FIND}) && $dh{EXCLUDE_FIND} ne '') {
    $find_options .= "! \\( $dh{EXCLUDE_FIND} \\) -a ";
}

if ($dh{AS_NEEDED}) {
    $find_options = "/usr/share/libtool/config/ltmain.sh . " . $find_options;
}

if (-e "debian/autoreconf") {
    @directories=filearray("debian/autoreconf", ".");
    $find_options = join(" ",@directories)." ".$find_options;
}

if (-e "debian/autoreconf.before" || -e "debian/autoreconf.after") {
    error("Can only be run once, see dh-autoreconf(7)");
}

my %modes = (
    'md5' => "find $find_options -type f -exec md5sum {} \\;",
    'timesize' => "find $find_options -type f -printf \"%s|%T@  %p\n\""
);

my $find = $modes{$dh{MODE} || "md5"} ||
    error("Unknown value $dh{MODE} passed to --mode");

complex_doit("$find > debian/autoreconf.before");

eval {
    # Run autoreconf to recreate the needed files.
    @ARGV ? doit(@ARGV, @{$dh{U_PARAMS}}) : doit('autoreconf', '-f', '-i', @directories);
    1;
} or do {
    $exception = $@;
};

complex_doit("$find > debian/autoreconf.after");

# Let's fail here if autoreconf failed.
die $exception if (defined $exception);

# Fix ltmain.sh to support -Wl,--as-needed
if ($dh{AS_NEEDED}) {
    open(FILE, 'debian/autoreconf.after') or die($!);
    my $ltcheck = "";
    while(<FILE>) {
        chomp($_);
        my ($checksum, $filename) = split;
        if ($filename eq "/usr/share/libtool/config/ltmain.sh") {
            $ltcheck = $checksum;
        } elsif ($filename =~ m/\/ltmain.sh$/ and $checksum eq $ltcheck) {
            doit("patch", "-f", "--no-backup-if-mismatch", "-i",
                 "/usr/share/dh-autoreconf/ltmain-as-needed.diff",
                 $filename);
        }
    }
    close(FILE);
}

=head1 SEE ALSO

L<debhelper(7)>, L<dh_autoreconf_clean(1)>, L<dh-autoreconf(7)>

=head1 AUTHOR

Julian Andres Klode <jak@debian.org>

=cut