NAME
Module::Build::Using::PkgConfig - extend Module::Build to more easily
use platform libraries provided by pkg-config
SYNOPSIS
In Build.PL:
use Module::Build::Using::PkgConfig;
my $build = Module::Build::Using::PkgConfig->new(
module_name => "Module::Here",
... # other arguments as per Module::Build
);
# A platform library provided by pkg-config
$build->use_pkgconfig( "libfoo" );
# We need at least a given version
$build->use_pkgconfig( "libbar",
atleast_version => "0.5",
);
# A platform librariy that's also wrapped as an Alien module
$build->use_pkgconfig( "libsplot",
atleast_version => "1.0",
alien => "Alien::libsplot",
alien_version => "0.05", # Alien::libsplot 0.05 provides libsplot v1.0
);
$build->create_build_script;
DESCRIPTION
This subclass of Module::Build provides some handy methods to assist
the Build.PL script of XS-based module distributions that make use of
platform libraries managed by pkg-config.
As well as supporting libraries installed on a platform-wide basis and
thus visible to pkg-config itself, this subclass also assists with
Alien::-based wrappers of these system libraries, allowing them to be
dynamically installed at build time if the platform does not provide
them.
RPATH generation
This module also provides some helper code to generate the required
RPATH arguments needed to link against the libraries found by
inspecting the extra_linker_flags. This attempts to duplicate the same
logic performed by libtool when it would link a C program or library,
as we don't get to use its code when linking dynamic libraries for
Perl.
PROPERTIES
no_late_aliens => BOOL
If true, applies the no_late_alien option to every use of
use_pkgconfig that specifies an Alien module.
METHODS
use_pkgconfig
$build->use_pkgconfig( $modname, ... )
Requires the given pkg-config module of the given version, and extends
the compiler and linker arguments sufficient to build from it.
Takes the following named options:
atleast_version => $modver
If given, the pkg-config module is required to be at least the given
version. If unspecified, then any version is considered sufficient.
alien => $alien
If given and the pkg-config module does not exist, try to use the
given Alien:: module to provide it instead.
If this module is not yet available and the no_late_alien option is
not true, the Alien module is added to the requires dynamic
dependencies and checked again at build action time.
no_late_alien => BOOL
If true, suppresses the dynamic requires feature of Alien modules
described above.
alien_version => $version
If the Alien:: module is not available, gives the module version of
it that will be required to provide the pkg-config module of the
required version. This gets added to requires.
If neither the pkg-config module and no Alien:: module was requested
(or none was found and no_late_alien was set), this method dies with an
OS unsupported message, which is usually what is required for a
Build.PL script.
try_pkconfig
$ok = $build->try_pkconfig( $modname, ... )
Boolean-returning version of "use_pkgconfig". If successful, returns
true. If it fails it returns false rather than dying, allowing the
Build.PL script to take alternative action.
pkgconfig_atleast_version
$ok = $build->pkgconfig_atleast_version( $modname, $modver )
Returns true if the pkg-config module name exists and has at least the
given version.
add_cflags_libs_from_pkgconfig
$build->add_cflags_libs_from_pkgconfig( $modname )
Extend the extra_compiler_flags and extra_linker_flags arguments from
the --cflags and --libs from the given pkg-config module name.
alien_atleast_version
$ok = $build->alien_atleast_version( $alien, $modver )
Returns true if the given Alien:: module provides a pkg-config module
version at least the given version.
add_cflags_libs_from_alien
$build->add_cflags_libs_from_alien( $alien )
Extend the extra_compiler_flags and extra_linker_flags arguments from
the --cflags and --libs from the given Alien:: module name.
use_late_alien
$ok = $build->use_late_alien( $alien, ... )
Adds an Alien module directly to the requires hash, and makes a note to
use its cflags and libraries later at build time.
Normally this method would not be necessary as it is automatically
called from use_pkgconfig if required, but one use-case may be to
provide a final last-ditch attempt after trying some other possible
attempts, after an earlier call to use_pkgconfig with no_late_alien
set.
push_extra_compiler_flags
$build->push_extra_compiler_flags( @flags )
Appends more values onto the extra_compiler_flags.
push_extra_linker_flags
$build->push_extra_linker_flags( @flags )
Appends more values onto the extra_linker_flags.
TODO
* Consider a quiet option to suppress verbose printing
* Consider defining a constructor argument, perhaps
build_requires_pkgconfig, to neaten the common case of simple
requirements.
* Consider further stealing the various helper methods from
ExtUtils::CChecker and possibly splitting this class into a lower
"C-using XS modules" and higher-level pkg-config+Alien layer.
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>