<div class="blog">
<h1 id="NAME">
-Updates and Design Decisions
+The Build Process of SDL Perl
</h1>
<div class="CONTENT">
-<div align="right"><i><br />Storm clouds loom,<br />Thunder cracks,<br />Lightning blinds,<br />Farmers rejoice.<br /></i></div><br /><b>Some quick updates:</b><br />After someone bugged me to update the Ohloh site for <a href="https://www.ohloh.net/p/sdlpl/">SDL perl</a>, I finally got around to doing it. <br /><br /><br /><b>Some good news:</b><br />v2.2.2.11 seems to be doing a good job considering it has been started to be picked up <a href="http://ftp.debian.org/pool/main/s/sdlperl/">Debian</a>, Mandriva and other packager maintainers. The <a href="http://search.cpan.org/dist/SDL_Perl/">stats</a> are currently at <span style="font-size: x-small;">[PASS(11) FAIL(6) NA(1) UNKNOWN(35)]</span>.<br /><br /><b>Some OK news:</b><br />As you can see we have some fails occurring in the smoke tests. This is occurring due to the <a href="http://cpansearch.perl.org/src/KTHAKORE/SDL_Perl-v2.2.2.11/t/mixerpm.t">test</a> on Mixer.pm. Mixer.pm depends on a <a href="http://www.nntp.perl.org/group/perl.cpan.testers/2009/09/msg5250346.html">sound card being available</a> to the user running the test. This can be fixed by adjusting the test to check for sound cards before it runs but I am at a lost on how to do that.<br />In regards to the unknowns occurring it is due to the *nixes and macs not having SDL libs installed. The will be fixed when Alien::SDL downloads and compiles sources.<br /><br /><b>Some not-so-great news:</b><br />Currently the XS code simplification work requires redesign and there are several different ways of redesigning. This may break backwards compatibility, hopefully we can work around this. Soon we will present the two arguments for the designs in the <a href="mailto:sdl-devel@perl.org">mailing list</a>. <br /><br /><br />Until next time here is a hint of something coming soon (credits go to garu):<br /><div class="separator" style="clear: both; text-align: center;"><a href="http://imgur.com/B0a1y.png" imageanchor="1" style="margin-left: 1em; margin-right: 1em;"><img border="0" height="150" src="http://imgur.com/B0a1y.png" width="200" /></a></div><i><br /></i><br /><i>--yapgh</i><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/3102167581424744259-1014994097230880621?l=yapgh.blogspot.com'/></div></div>
\ No newline at end of file
+<p>A while ago I had a long chat with mst on why SDL uses Module::Build rather then Make. I told him it is a simple matter of code inertia. The existing Module::Build system has worked well for us so far. Never the less, he convinced me that switching to Make will improve debugging the Build system. But to be able to switch we will need to completely replace the Build system. I am not prepared to do that so I will just present the requirements so mst or someone else can at least attempt to switch.</p><br />
+<br />
+<h3>The Build Process </h3><br />
+<b> Alien::SDL </b><br />
+<br />
+<p>SDL Perl depends on a few C libraries for a complete install. This is handled by Alien::SDL. First we look for existing SDL libraries and dependencies by doing a <a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L581">File::Find</a> for headers. If these headers are found we present and option for the user to use those. We then store these locations in Alien::SDL->config options 'cflags', 'prefix' and 'libs'. If we do not have libraries available even for a minimum SDL installed ( SDL.h is not found). We provide several platform specific options. </p><br />
+<p>For windows we have a simpler process. We download<a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L7"> prebuilt </a>binaries ( and checksum ) based on the user's selection and just copy them in to the right location. Again the 'prefix', 'cflags', and 'libs' is saved in Alien::SDL->config. </p><br />
+<p>For *nix/MacOSX we download sources and attempt to compile them. To be able to do this we download several other dependencies like libpng, jpeg and pango. You can see how we do this using hashes <a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L404">here</a>. During the compile process we also apply patches as needed for the <a href="http://github.com/kthakore/Alien_SDL/blob/master/inc/My/Utility.pm#L430">sources</a>. Once this is done we can head to SDL Build.PL </p><br />
+<b> SDL Perl dependency resolution </b><br />
+<br />
+SDL's Build is responsible for linking the right libraries to the correct XS. If libraries are missing it will disable the component (not put it in SDL->config). <br />
+<br />
+<p>For example to build <a href="http://github.com/kthakore/SDL_perl/blob/master/Build.PL#L342">Image.xs</a> we require libsdl, libsdl_image and lib[jpg|png|tiff]. So we would check for these headers in the prefix provided by Alien::SDL->config. If they are not provided we will disable the SDL::Image module. </p><br />
+<p>More over the availability of each library is specified as a -DMACRO to the gcc compiler. This way we can prevent XS failures due to missing libraries using #DEFINES. Here the SDL_image macro is <a href="http://github.com/kthakore/SDL_perl/blob/master/Build.PL#L422">defined</a> and <a href="http://github.com/kthakore/SDL_perl/blob/master/src/Image.xs#L13">used</a>. The availability of the module is then available from <a href="http://github.com/kthakore/SDL_perl/blob/master/t/image.t#L20">SDL::Config->has()</a> <br />
+<br />
+<br />
+<b> Conclusion </b> <br />
+<p>This is a high level overview of our Build process, because frankly I hate traumatizing my brain with this again. Credits have to go to FROGGS and kmx for helping with this Build scheme. Hopefully my post have helped people at the very least appreciate the problem scope of this Build system. That said I believe a fresh written build system, with these requirements in mind, will be more then welcome.<br />
+</p><div class="blogger-post-footer"><img width='1' height='1' src='https://blogger.googleusercontent.com/tracker/3102167581424744259-4514794130108689562?l=yapgh.blogspot.com' alt='' /></div>
+<p><a href="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/0/da"><img src="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/0/di" border="0" ismap="true"></img></a><br/>
+<a href="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/1/da"><img src="http://feedads.g.doubleclick.net/~a/SHI8waMCUMOT4LmhUSkV3-Y1cK8/1/di" border="0" ismap="true"></img></a></p><img src="http://feeds.feedburner.com/~r/YetAnotherPerlGameHackeryapgh/~4/fTwVmM222rA" height="1" width="1"/></div></div>
\ No newline at end of file
projects / sdlgit/SDL-Site.git / blobdiff