[webkit-dev] Build File Maintenance (was Re: Please welcome GYP to the our dysfunctional build family)

[David Kilzer]

> At one point, I started on a script (located in 
> WebKitTools/Scripts/update-sources-list.py) whose idea
> was to take the list of common sources from one file,
> and make changes to MSVC, Qt, GTK, etc. build systems,
> so that WebKit devs need only add the file once, run
> the script, and commit the results. I got it as far as
> theoretically generating the Qt and GTK file lists, but
> I don't think anyone on those ports tried integrating
> it into their build system, and I sort of moved on to
> other things.

I should add that I haven't felt enough pain (maybe my threshold is too high?) to attempt to write a script that updates all of the build systems when adding a new source file.

Instead of regenerating parts of the build files, I though such a script should simply do in-place edits of each of the build files.  My current thinking was that if you could provide an "example" source file that would be in the same "group" as the new source file, then you could embed less knowledge about each build format in the tool and just make it smart enough to add new lines for the source file for each build file.  (For example, on Xcode project files, the only extra thing you'd need to do when adding a new file is to generate an ID for the new file(s) that didn't already exist in the current project file.)  I think this would probably handle the most common cases.

Dave



----- Original Message ----
> From: Kevin Ollivier <kevino at theolliviers.com>
> To: Dimitri Glazkov <dglazkov at chromium.org>
> Cc: Mark Mentovai <mark at chromium.org>; WebKit Development <webkit-dev at lists.webkit.org>
> Sent: Friday, July 10, 2009 8:52:57 AM
> Subject: [webkit-dev] Build File Maintenance (was Re: Please welcome GYP to the our dysfunctional build family)
> 
> Hi Dimitri and all,
> 
> Congrats on getting this into WebKit! Actually, I'm in the middle of a build 
> system switch as well - to waf, a re-write of scons that removed many of the 
> performance issues related to searching and calculating dependencies, and which 
> has added some nice features as well (such as .app bundle building). I haven't 
> completed the switch so I can't do preliminary benchmarks, but I'm pretty sure 
> it's actually as fast or faster than make on *nix/Mac. (And BTW, it will 
> probably make Apple devs happy to hear that I'm no longer using the horrid 
> build-wxwebkit bash script to manage the build, but instead have integrated 
> everything into build-webkit finally!)
> 
> The main reason I bring this up, though, is because I think this sort of thing 
> shows that we're unlikely to centralize our build systems any time soon, and I 
> feel a bit sorry for the core devs who, as they accept new ports, are probably 
> finding it more and more tedious, if not difficult, to make sure all the 
> projects get updated by a change to the common parts of the build. They've been 
> very helpful in terms of trying to keep the ports in shape when they make 
> changes, and I feel like I'd like to do what I can to make it easier and faster 
> to keep the other ports in sync.
> 
> At one point, I started on a script (located in 
> WebKitTools/Scripts/update-sources-list.py) whose idea was to take the list of 
> common sources from one file, and make changes to MSVC, Qt, GTK, etc. build 
> systems, so that WebKit devs need only add the file once, run the script, and 
> commit the results. I got it as far as theoretically generating the Qt and GTK 
> file lists, but I don't think anyone on those ports tried integrating it into 
> their build system, and I sort of moved on to other things.
> 
> Unfortunately, right now I'm really swamped (my build system rewrite was 
> prompted by WebKit exceeding internal, hardcoded, Bakefile limits, not by 
> choice), but if a common location for the source files list could be decided 
> upon, I really think a script would be a simple matter to write up (even in Perl 
> :P ), and I think it would probably save developers time and reduce build 
> breakages as well, which I think would add up to a lot of saved time for a lot 
> of people over the long term. The only format I'm not sure if we could automate 
> reliably would be the XCode format (at least, on non-Mac machines), because IIUC 
> we'd need some sort of parser for it, but Apple is the only port maintaining 
> those directly IIUC, as now Chromium will be using GYP to update their XCode 
> projects. So even if we couldn't solve the XCode issue, that would drop it to 
> updating two locations tops.
> 
> So, does anyone think this would be a bad idea, or have any alternate 
> suggestions on how to improve things? If not, is anyone willing to take the ball 
> and run with it? I'd be willing to invest some more time in it, but my ability 
> to commit to it over the next couple weeks at least would be very limited.
> 
> Thanks,
> 
> Kevin
> 
> On Jul 9, 2009, at 9:23 PM, Dimitri Glazkov wrote:
> 
> > Dear WebKiteurs,
> > 
> > In our persisting quest to be more like a common WebKit port, we have
> > added Chromium build files to the tree this afternoon. These files are
> > WebCore/WebCore.gypi and JavaScriptCore/JavaScriptCore.gypi and they
> > are the GYP include files. As you may know, we use GYP
> > (http://code.google.com/p/gyp) for generating MSVC, XCode, Scons, and
> > even Make projects for Chromium.
> > 
> > We are rather fond of GYP. Perhaps it is because it allows us to
> > maintain one set of project files for all three Chromium platforms;
> > 
> > or maybe because it lets us to do things like WebCore.gypi, where we
> > can just mindlessly add all project files to the list and then use
> > various neat GYP filtering facilities to narrow them down to sets that
> > are relevant for specific builds;
> > 
> > or maybe because it easifies creating cross-platform and
> > cross-build-system targets, actions, and rules;
> > 
> > or maybe because we just love saying "Gyp!"
> > 
> > I don't truthfully know.
> > 
> > What I do know is that starting now, we'd love for you to remember
> > WebCore.gypi and JavaScriptCore.gypi when you are adding or removing
> > files from WebCore or JavaScriptCore. Thanks to the power of GYP, you
> > don't have worry whether this file will be used by Chromium: the rule
> > is that if there's a project file change, it applies to the *.gypi
> > files. The format is very simple and intuitive, a simple Python/JSONey
> > list+dict.
> > 
> > Thank you for your attention, men and women of WebKit.
> > 
> > :DG<
> > _______________________________________________
> > webkit-dev mailing list
> > webkit-dev at lists.webkit.org
> > http://lists.webkit.org/mailman/listinfo.cgi/webkit-dev
> 
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