#! /usr/bin/perl -w

=head1 NAME

dh_girepository - compute dependencies for GObject introspection packages

=cut

use strict;
use File::Find;
use Dpkg::Deps;
use Dpkg::Control;
use Debian::Debhelper::Dh_Lib;

=head1 SYNOPSIS

B<dh_girepository> [I<debhelper options>] [-lI<directory>] [-pI<directory>] [-XI<item>] [I<private [...]>]

=head1 DESCRIPTION

dh_girepository is a debhelper program to compute dependencies for packages
shipping GObject introspection data.

The dependencies are generated in the ${gir:Depends} substitution variable.

The minimal version of the generated dependencies is calculated by looking
first at the version of the packages declared in the build-dependencies of the
building package. If a package is not declared in the build-dependencies, the
minimal version of that package is calculated by looking at the version of the
package containing the corresponding .gir file defined in the
build-dependencies.

Note that dh_girepository will not be executed automatically by dh; you
need to use C<dh $@ --with gir> for C<dh> to include it.

=head1 OPTIONS

=over 4

=item B<-l>I<directory>

Specify a directory (or a colon-separated list of directories) where to look
for the .gir XML files that were used to generate the .typelib files that
are scanned. This option is only necessary if those files are not shipped in
another, architecture-dependent package.

=item B<-p>I<directory>

Specify a directory (or a colon-separated list of directories) where to look
for the dependencies. This is useful when a dependency ships the .typelib
in a private directory.

=item B<-X>I<item>

Exclude files that contain I<item> anywhere in their filename from being
analyzed.

=item I<private [...]>
List of directories where to look for typelibs and the corresponding .gir
files. Useful when the package installs its typelibs in a private
directory, such as /usr/lib/<package>. Library dependencies are also looked
there, in case your typelib depends on a library that you ship on a private
directory.

=back

=head1 CONFORMS TO

GObject introspection mini policy as of 2011-03-30.

=cut

# Initialisation code
init(options => {
    "l=s", => \$dh{L_PARAMS},
    "p=s", => \$dh{P_PARAMS},
});
my @paths_first = ();
my @privdirs = ();
if ($dh{L_PARAMS}) {
    push @paths_first, split /:/, $dh{L_PARAMS};
}
if ($dh{P_PARAMS}) {
    push @privdirs, split /:/, $dh{P_PARAMS};
}
isnative($dh{MAINPACKAGE}); # Necessary to have $dh{VERSION}
my $bin_version = $dh{VERSION};
my @archpackages = getpackages("arch");

my $triplet = `dpkg-architecture -qDEB_HOST_MULTIARCH`;
chomp $triplet;
my $typelib_multiarch_path = "/usr/lib/$triplet/girepository-1.0";
my $typelib_path = "/usr/lib/girepository-1.0";

my @typelibdirs = (@ARGV, $typelib_path, $typelib_multiarch_path);
my $gir_path = "/usr/share/gir-1.0";
my @girdirs = (@ARGV, $gir_path);
my $arch_triplet = `dpkg-architecture -qDEB_HOST_MULTIARCH`;
chomp $arch_triplet;
my @privlibdirs = (@ARGV);
my @libdirs = ("/lib/$arch_triplet", "/lib", "/usr/lib/$arch_triplet", "/usr/lib", @privlibdirs);
my $format;

# Get Build-Depends in an array
my @bdeps;

my $ctrl = Dpkg::Control->new(type => CTRL_INFO_SRC);
$ctrl->load('debian/control');
foreach my $field (qw(Build-Depends Build-Depends-Arch Build-Depends-Indep)) {
    if (defined $ctrl->{$field}) {
        my $value = deps_parse($ctrl->{$field}, build_dep => 1);
        push @bdeps, split ', ', $value->output;
    }
}

# We can’t parse .typelib files, so we need the corresponding .gir
# somewhere in the same source package (or with -l).

sub find_gir {
    my $req = shift;
    $req =~ s/\.typelib$//;
    my $f;
    foreach my $path (@paths_first) {
        $f = "$path/$req.gir";
        if (-f $f) {
            verbose_print ("Found $req.gir in $path");
            return $f;
        }
    }
    foreach my $otherpkg (@archpackages) {
        foreach my $girdir (@girdirs) {
            $f = tmpdir($otherpkg)."$girdir/$req.gir";
            if (-f $f) {
                verbose_print ("Found $req.gir in $otherpkg package");
                return $f;
            }
        }
    }
    error("Could not find gir file for $req.typelib");
}


# Function used for dependencies on other .typelib files

sub require_typelib {
    my $req = shift;
    my $package = shift;
    my $fullpath = "";
    foreach my $typelibdir (@typelibdirs) {
        $fullpath = "$typelibdir/$req";

        verbose_print ("Dependency: $req");
        foreach my $typelibdir (@typelibdirs) {
            if (-f tmpdir($package)."$typelibdir/$req") {
                verbose_print("  found in the same package");
                return;
            }
        }
        foreach my $otherpkg (@archpackages) {
            if (-f tmpdir($otherpkg)."$fullpath") {
                error("Dependency on $otherpkg with a different format than $format") unless $otherpkg =~ /^gir$format/;
                addsubstvar ($package, "gir:Depends", $otherpkg, "= $bin_version");
                return;
            }
        }
        foreach my $privpath (@privdirs) {
            if (-f "$privpath/$req") {
                verbose_print ("  found in $privpath");
                $fullpath = "$privpath/$req";
                last;
            }
        }

        if (-f "$fullpath") {
            my @output = (split ':', `dpkg -S $fullpath 2>/dev/null`);
            error("$fullpath does not belong to any package") unless @output;
            my $deppkg = $output[0];
            error("Dependency on $deppkg with a different format than $format") unless $deppkg =~ /^gir$format/;
            # Look for version information in build-dependencies
            my $found = 0;
            foreach my $bdep (@bdeps) {
                if ($bdep =~ /^\s*([a-z0-9\._\-\+]+)\s*\((.*)\)/) {
                    if ($1 eq $deppkg) {
                        addsubstvar ($package, "gir:Depends", $1, $2);
                        $found = 1;
                    }
                }
            }
            if (! $found) {
                my $fullpath_gir = "";
                (my $req_gir = $req) =~ s/\.typelib$/\.gir/;
                foreach my $girdir (@girdirs) {
                    if (-f "$girdir/$req_gir") {
                        $fullpath_gir = "$gir_path/$req_gir";
                        my @output_gir = (split ':', `dpkg -S $fullpath_gir 2>/dev/null`);
                        error("$fullpath_gir does not belong to any package") unless @output_gir;
                        my $deppkg_gir = $output_gir[0];
                        foreach my $bdep (@bdeps) {
                            if ($bdep =~ /^\s*([a-z0-9\._\-\+]+)\s*\((.*)\)/) {
                                if ($1 eq $deppkg_gir) {
                                    addsubstvar ($package, "gir:Depends", $deppkg, $2);
                                    $found = 1;
                                }
                            }
                        }
                    }
                }
            }
            if (! $found) {
                addsubstvar ($package, "gir:Depends", $deppkg);
            }
            return;
        }
    }
    error("Could not find $req dependency");
}


sub find_library_in_package {
    my $req = shift;
    my $package = shift;
    my $tmp = "";
    if ($package) {
        $tmp = tmpdir ($package);
    }
    my @loclibdirs = grep -d, map "$tmp$_", @libdirs;
    foreach my $libdir (@loclibdirs) {
        if (-f "$libdir/$req" or -l "$libdir/$req") {
            return "$libdir/$req";
        }
    }
}

sub find_library {
    my $req = shift;
    my $package = shift;

    my $file = find_library_in_package ($req, $package);
    if ($file) {
        verbose_print ("    found in the same package");
    } else {
        foreach my $otherpkg (@archpackages) {
            $file = find_library_in_package ($req, $otherpkg);
            if ($file) {
                verbose_print ("    found in $otherpkg");
                last;
            }
        }
    }
    if (!$file) {
        $file = find_library_in_package ($req);
        if ($file) {
            verbose_print ("    found on filesystem");
        } else {
            error ("Could not find library $req");
        }
    }

    if (-l $file and not -f $file) {
        # We have a symbolic link that points to another package
        verbose_print ("    ... it's a symlink ...");
        return find_library (readlink ($file), $package);
    }
    return $file;
}

foreach my $package (@{$dh{DOPACKAGES}}) {
    my $tmp = tmpdir($package);
    my $ext = pkgext($package);
    my @bin_files = ();
    my @c_files = ();
    my @typelib_deps = ();
    my $multiarch_required = 0;

    foreach my $dir (@typelibdirs) {
        my $typelibdir = "$tmp$dir";
        next unless -d $typelibdir;
        opendir(DIRHANDLE, $typelibdir);
        while (my $typelib = readdir(DIRHANDLE)) {
            next unless $typelib =~ /\.typelib$/;
            next if excludefile ($typelib);
            my $girfile = find_gir ($typelib);
            error("Unable to open $girfile") unless open (my $f, "<", $girfile);
            verbose_print ("$girfile...");
            my @libraries = ();
            my @symbols = ();
            my $infunction = 0;
            while (<$f>) {
                # "Parse" the XML file
                chomp;
                if (/<repository.+?version="(.*?)"/) {
                    # gir format version
                    $format="$1";
                } elsif (/<include\s+name="(.*?)"\s+version="(.*?)"\/>/) {
                    # Dependency on another typelib file
                    my $deptypelib="$1-$2.typelib";
                    verbose_print ("  Dependency: $deptypelib");
                    if (! grep { $_ eq $deptypelib } @typelib_deps) {
                        push @typelib_deps, $deptypelib;
                    }
                } elsif (/shared-library="(.*?)"/) {
                    # Dependency on a shared library
                    foreach my $shlibname (split ",", $1) {
                        if ($shlibname !~ /\.so/) {
                            $shlibname = "lib$shlibname.so"
                        }
                        verbose_print ("  Library: $shlibname");
                        push @libraries, find_library ($shlibname, $package);
                    }
                } elsif (/<(method|constructor|function)\s.*c:identifier="(.*?)"/) {
                    push @symbols, $2;
                } elsif (/<(method|constructor|function)/) {
                    $infunction = 1;
                } elsif ($infunction and /c:identifier="(.*?)"/) {
                    push @symbols, $1;
                }
                if (/>$/) {
                    $infunction = 0;
                }
            }
            close $f;
            error("Unable to determine gir format") unless $format;
            error("Package name $package doesn't match gir format $format")
                unless $package =~ /^gir$format/
                or not $typelibdir =~ /usr\/lib\/girepository/;
            verbose_print(sprintf("  %d symbols found", $#symbols+1));
            if (@libraries or @symbols) {
                my $c_file = "$typelibdir/$typelib.c";
                my $bin_file = "$typelibdir/$typelib.so";
                verbose_print ("  writing $c_file");
                if (!$dh{NO_ACT}){
                    error("Unable to open $girfile") unless open (F, ">", $c_file);
                    print F "void gir_dummy_function () {\n";
                    foreach my $symbol (@symbols) {
                        print F "$symbol ();\n";
                    }
                    print F "}";
                    close F;
                }
                push @c_files, $c_file;

                # Build a dummy binary using all referenced symbols and libraries
                # We use -shared so that gcc doesn’t try to resolve references
                verbose_print ("  building $bin_file");
                doit (("gcc", "-Wno-implicit-function-declaration", "-shared", "-fPIC", "-o", $bin_file, $c_file, @libraries));
                push @bin_files, $bin_file;
            }
            if ($typelibdir =~ $typelib_multiarch_path) {
                $multiarch_required = 1;
            }
        }
    }
    if (@bin_files) {
        # dpkg-shlibdeps expects this directory to exist
        if (! -d "$tmp/DEBIAN") {
            install_dir("$tmp/DEBIAN");
        }

        # Let dpkg-shlibdeps generate the corresponding dependencies
        # It must run first since otherwise it overwrites the variable
        push @privlibdirs, $ENV{"LD_LIBRARY_PATH"} if $ENV{"LD_LIBRARY_PATH"};
        my $llp = join (":", @privlibdirs);
        complex_doit ("LD_LIBRARY_PATH=$llp dpkg-shlibdeps -pgir -Tdebian/${ext}substvars -xlibc6 -xlibc0 @bin_files");
    }
    doit (("rm", "-f", @c_files, @bin_files));

    # Generate dependencies on other .typelib files
    foreach my $dep (@typelib_deps) {
        require_typelib ($dep, $package);
    }
}

=head1 SEE ALSO

L<debhelper(7)>

This program is a part of gobject-introspection but is made to work with 
debhelper.

=head1 AUTHOR

Josselin Mouette <joss@debian.org>

=cut