NAME

       ExtUtils::Depends - Easily build XS extensions that depend on XS extensions

SYNOPSIS

               use ExtUtils::Depends;
               $package = new ExtUtils::Depends ('pkg::name', 'base::package')
               # set the flags and libraries to compile and link the module
               $package->set_inc("-I/opt/blahblah");
               $package->set_libs("-lmylib");
               # add a .c and an .xs file to compile
               $package->add_c('code.c');
               $package->add_xs('module-code.xs');
               # add the typemaps to use
               $package->add_typemaps("typemap");
               # install some extra data files and headers
               $package->install (qw/foo.h data.txt/);
               # save the info
               $package->save_config('Files.pm');

               WriteMakefile(
                       'NAME' => 'Mymodule',
                       $package->get_makefile_vars()
               );

DESCRIPTION

       This module tries to make it easy to build Perl extensions that use functions and typemaps
       provided by other perl extensions. This means that a perl extension is treated like a
       shared library that provides also a C and an XS interface besides the perl one.

       This works as long as the base extension is loaded with the RTLD_GLOBAL flag (usually done
       with a

               sub dl_load_flags {0x01}

       in the main .pm file) if you need to use functions defined in the module.

       The basic scheme of operation is to collect information about a module in the instance,
       and then store that data in the Perl library where it may be retrieved later.  The object
       can also reformat this information into the data structures required by
       ExtUtils::MakeMaker's WriteMakefile function.

       When creating a new Depends object, you give it a name, which is the name of the module
       you are building.   You can also specify the names of modules on which this module
       depends.  These dependencies will be loaded automatically, and their typemaps, header
       files, etc merged with your new object's stuff.  When you store the data for your object,
       the list of dependencies are stored with it, so that another module depending on your
       needn't know on exactly which modules yours depends.

       For example:

         Gtk2 depends on Glib

         Gnome2::Canvas depends on Gtk2

         ExtUtils::Depends->new ('Gnome2::Canvas', 'Gtk2');
            this command automatically brings in all the stuff needed
            for Glib, since Gtk2 depends on it.

METHODS

       $object = ExtUtils::Depends->new($name, @deps)
           Create a new depends object named $name.  Any modules listed in @deps (which may be
           empty) are added as dependencies and their dependency information is loaded.  An
           exception is raised if any dependency information cannot be loaded.

       $depends->add_deps (@deps)
           Add modules listed in @deps as dependencies.

       (hashes) = $depends->get_deps
           Fetch information on the dependencies of $depends as a hash of hashes, which are
           dependency information indexed by module name.  See "load".

       $depends->set_inc (@newinc)
           Add strings to the includes or cflags variables.

       $depends->set_libs (@newlibs)
           Add strings to the libs (linker flags) variable.

       $depends->add_pm (%pm_files)
           Add files to the hash to be passed through ExtUtils::WriteMakefile's PM key.

       $depends->add_xs (@xs_files)
           Add xs files to be compiled.

       $depends->add_c (@c_files)
           Add C files to be compiled.

       $depends->add_typemaps (@typemaps)
           Add typemap files to be used and installed.

       $depends->add_headers (list)
           No-op, for backward compatibility.

       $depends->install (@files)
           Install @files to the data directory for $depends.

           This actually works by adding them to the hash of pm files that gets passed through
           WriteMakefile's PM key.

       $depends->save_config ($filename)
           Save the important information from $depends to $filename, and set it up to be
           installed as name::Install::Files.

           Note: the actual value of $filename seems to be irrelevant, but its usage is kept for
           backward compatibility.

       hash = $depends->get_makefile_vars
           Return the information in $depends in a format digestible by WriteMakefile.

           This sets at least the following keys:

                   INC
                   LIBS
                   TYPEMAPS
                   PM

           And these if there is data to fill them:

                   clean
                   OBJECT
                   XS

       hashref = ExtUtils::Depends::load (name)
           Load and return dependency information for name.  Croaks if no such information can be
           found.  The information is returned as an anonymous hash containing these keys:

           instpath
               The absolute path to the data install directory for this module.

           typemaps
               List of absolute pathnames for this module's typemap files.

           inc CFLAGS string for this module.

           libs
               LIBS string for this module.

           deps
               List of modules on which this one depends.  This key will not exist when loading
               files created by old versions of ExtUtils::Depends.

       $depends->load_deps
           Load $depends dependencies, by calling "load" on each dependency module.  This is
           usually done for you, and should only be needed if you want to call "get_deps" after
           calling "add_deps" manually.

SUPPORT

   Bugs/Feature Requests
       Version 0.2 discards some of the more esoteric features provided by the older versions.
       As they were completely undocumented, and this module has yet to reach 1.0, this may not
       exactly be a bug.

       This module is tightly coupled to the ExtUtils::MakeMaker architecture.

       You can submit new bugs/feature requests by using one of two bug trackers (below).

       CPAN Request Tracker
           You can submit bugs/feature requests via the web by going to
           <https://rt.cpan.org/Public/Bug/Report.html?Queue=ExtUtils-Depends> (requires PAUSE ID
           or Bitcard), or by sending an e-mail to "bug-ExtUtils-Depends at rt.cpan.org".

       Gnome.org Bugzilla
           Report bugs/feature requests to the 'gnome-perl' product (requires login)
           <http://bugzilla.gnome.org/enter_bug.cgi?product=gnome-perl>

       Patches that implement new features with test cases, and/or test cases that exercise
       existing bugs are always welcome.

       The Gtk-Perl mailing list is at "gtk-perl-list at gnome dot org".

   Source Code
       The source code to ExtUtils::Depends is available at the Gnome.org Git repo
       (<https://git.gnome.org/browse/perl-ExtUtils-Depends/>).  Create your own copy of the Git
       repo with:

         git clone git://git.gnome.org/perl-ExtUtils-Depends (Git protocol)
         git clone https://git.gnome.org/browse/perl-ExtUtils-Depends/ (HTTPS)

SEE ALSO

       ExtUtils::MakeMaker.

AUTHOR

       Paolo Molaro <lupus at debian dot org> wrote the original version for Gtk-Perl.  muppet
       <scott at asofyet dot org> rewrote the innards for version 0.2, borrowing liberally from
       Paolo's code.

MAINTAINER

       The Gtk2 project, <http://gtk2-perl.sf.net>/"gtk-perl-list at gnome dot org".

LICENSE

       This library is free software; you may redistribute it and/or modify it under the same
       terms as Perl itself.