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[debhelper.git] / Debian / Debhelper / Dh_Buildsystem.pm

# Defines debhelper buildsystem class interface and implementation
# of common functionality.
#
# Copyright: © 2008-2009 Modestas Vainius
# License: GPL-2+

package Debian::Debhelper::Dh_Buildsystem;

use strict;
use warnings;
use Cwd;
use File::Spec;
use Debian::Debhelper::Dh_Lib;

# Cache DEB_BUILD_GNU_TYPE value. Performance hit of multiple
# invocations is noticable when listing buildsystems.
our $DEB_BUILD_GNU_TYPE = dpkg_architecture_value("DEB_BUILD_GNU_TYPE");

# Build system name. Defaults to the last component of the class
# name. Do not override this method unless you know what you are
# doing.
sub NAME {
        my $self=shift;
        my $cls = ref($self) || $self;
        if ($cls =~ m/^.+::([^:]+)$/) {
                return $1;
        }
        else {
                error("ınvalid buildsystem class name: $cls");
        }
}

# Description of the build system to be shown to the users.
sub DESCRIPTION {
        "basic debhelper build system class (please provide description)";
}

# Default build directory. Can be overriden in the derived
# class if really needed.
sub DEFAULT_BUILD_DIRECTORY {
        "obj-" . $DEB_BUILD_GNU_TYPE;
}

# Constructs a new build system object. Named parameters:
# - builddir -     specifies build directory to use. If not specified,
#                  in-source build will be performed. If undef or empty,
#                  DEFAULT_BUILD_DIRECTORY will be used.
# - build_action - set this parameter to the name of the build action
#                  if you want the object to determine its is_buidable
#                  status automatically (with check_auto_buildable()).
#                  Do not pass this parameter if is_buildable flag should
#                  be forced to true or set this parameter to undef if
#                  is_buildable flag should be false.
# Derived class can override the constructor to initialize common object
# parameters and execute commands to configure build environment if
# is_buildable flag is set on the object.
sub new {
        my ($cls, %opts)=@_;

        my $self = bless({ builddir => undef, is_buildable => 1 }, $cls);
        if (exists $opts{builddir}) {
                if ($opts{builddir}) {
                        $self->{builddir} = $opts{builddir};
                }
                else {
                        $self->{builddir} = $self->DEFAULT_BUILD_DIRECTORY();
                }
        }
        if (exists $opts{build_action}) {
                if (defined $opts{build_action}) {
                        $self->{is_buildable} = $self->check_auto_buildable($opts{build_action});
                }
                else {
                        $self->{is_buildable} = 0;
                }
        }
        return $self;
}

# Test is_buildable flag of the object.
sub is_buildable {
        my $self=shift;
        return $self->{is_buildable};
}

# This instance method is called to check if the build system is capable
# to auto build a source package. Additional argument $action describes
# which operation the caller is going to perform (either configure,
# build, test, install or clean). You must override this method for the
# build system module to be ever picked up automatically. This method is
# used in conjuction with @Dh_Buildsystems::BUILDSYSTEMS.
#
# This method is supposed to be called with source root directory being
# working directory. Use $self->get_buildpath($path) method to get full
# path to the files in the build directory.
sub check_auto_buildable {
        my $self=shift;
        my ($action) = @_;
        return 0;
}

# Derived class can call this method in its constructor
# to enforce in-source building even if the user requested otherwise.
sub enforce_in_source_building {
        my $self=shift;
        if ($self->{builddir}) {
                # Do not emit warning unless the object is buildable.
                if ($self->is_buildable()) {
                        warning("warning: " . $self->NAME() .
                            " does not support building outside-source. In-source build enforced.");
                }
                $self->{builddir} = undef;
        }
}

# Derived class can call this method in its constructor to enforce
# outside-source building even if the user didn't request it.
sub enforce_outside_source_building {
        my ($self, $builddir) = @_;
        if (!defined $self->{builddir}) {
                $self->{builddir} = ($builddir && $builddir ne ".") ? $builddir : $self->DEFAULT_BUILD_DIRECTORY();
        }
}

# Get path to the specified build directory
sub get_builddir {
        my $self=shift;
        return $self->{builddir};
}

# Construct absolute path to the file from the given path that is relative
# to the build directory.
sub get_buildpath {
        my ($self, $path) = @_;
        if ($self->get_builddir()) {
                return File::Spec->catfile($self->get_builddir(), $path);
        }
        else {
                return File::Spec->catfile('.', $path);
        }
}

# When given a relative path in the source tree, converts it
# to the path that is relative to the build directory.
# If $path is not given, returns relative path to the root of the
# source tree from the build directory.
sub get_rel2builddir_path {
        my $self=shift;
        my $path=shift;

        if (defined $path) {
                $path = File::Spec->catfile(Cwd::getcwd(), $path);
        }
        else {
                $path = Cwd::getcwd();
        }
        if ($self->get_builddir()) {
                return File::Spec->abs2rel($path, Cwd::abs_path($self->get_builddir()));
        }
        return $path;
}

sub _mkdir {
        my ($cls, $dir)=@_;
        # XXX JEH is there any reason not to just doit("mkdir") ?
        # XXX MDX Replaced below part. This call is there to be
        # more verbose about errors (if accidently $dir in
        # non-dir form and to test for ! -d $dir.
        if (-e $dir && ! -d $dir) {
                error("error: unable to create '$dir': object already exists and is not a directory");
        }
        elsif (! -d $dir) {
                doit("mkdir", $dir);
                return 1;
        }
        return 0;
}

sub _cd {
        my ($cls, $dir)=@_;
        if (! $dh{NO_ACT}) {
                verbose_print("cd $dir");
                chdir $dir or error("error: unable to chdir to $dir");
        }
}

# Creates a build directory. Returns 1 if the directory was created
# or 0 if it already exists or there is no need to create it.
sub mkdir_builddir {
        my $self=shift;
        if ($self->get_builddir()) {
                return $self->_mkdir($self->get_builddir());
        }
        return 0;
}

# Changes working directory the build directory (if needed), calls doit(@_)
# and changes working directory back to the source directory.
sub doit_in_builddir {
        my $self=shift;
        if ($self->get_builddir()) {
                my $builddir = $self->get_builddir();
                my $sourcedir = $self->get_rel2builddir_path();
                $self->_cd($builddir);
                doit(@_);
                $self->_cd($sourcedir);
        }
        else {
                doit(@_);
        }
        return 1;
}

# In case of outside-source tree building, whole build directory
# gets wiped (if it exists) and 1 is returned. Otherwise, nothing
# is done and 0 is returned.
sub clean_builddir {
        my $self=shift;
        if ($self->get_builddir()) {
                if (-d $self->get_builddir()) {
                        doit("rm", "-rf", $self->get_builddir());
                }
                return 1;
        }
        return 0;
}


# Instance method that is called before performing any action (see below).
# Action name is passed as an argument. Derived classes overriding this
# method should also call SUPER implementation of it.
sub pre_action {
        my $self=shift;
        my ($action)=@_;
}

# Instance method that is called after performing any action (see below).
# Action name is passed as an argument. Derived classes overriding this
# method should also call SUPER implementation of it.
sub post_action {
        my $self=shift;
        my ($action)=@_;
}

# The instance methods below provide support for configuring,
# building, testing, install and cleaning source packages.
# In case of failure, the method may just error() out.
#
# These methods should be overriden by derived classes to
# implement buildsystem specific actions needed to build the
# source. Arbitary number of custom action arguments might be
# passed. Default implementations do nothing.
sub configure {
        my $self=shift;
}

sub build {
        my $self=shift;
}

sub test {
        my $self=shift;
}

# destdir parameter specifies where to install files.
sub install {
        my $self=shift;
        my $destdir=shift;
}

sub clean {
        my $self=shift;
}

1;