[webkit-dev] Please welcome GYP to the our dysfunctional build family

[Mark Mentovai]

Generate Your Projects, or GYP, was designed around Chromium's needs.
Maintaining distinct project files for different build environments
and different platforms put a great burden on our team, and was never
intended to be a long-term solution.  We really wanted to have a
single canonical description of the build from which we could generate
the native project files that developers were accustomed to.

One proposed solution was to treat our SCons build as canonical and
have it generate native project files.  This integration never really
came to fruition.  We had SCons generating Visual Studio projects for
simpler projects, but mapping the flexible SCons input language to the
more restrictive descriptions used in IDE project files proved
difficult.

We also considered CMake, and had it demonstrably working for some of
our smaller projects as well.  Unfortunately, transitioning to CMake
would have required moving everything over at once, without allowing
for some existing projects to be maintained "by hand" during a
transition period.  CMake-generated files contain absolute paths, so a
.tar or .zip of the source tree could not be primed with CMake output,
complicating the "bootstrapping" process for new contributors.  A less
significant factor was that CMake introduced an additional binary
build prerequisite, which would have had to have been installed
everywhere.  Python is already a prerequisite for Chromium, so a
Python tool was easier to deploy.

The net result of all of this was GYP, which was designed specifically
to meet Chromium's needs.  We were able to get GYP to generate project
files on all three of our main platforms fairly rapidly, and we
designed for (and eventually executed on some platforms) a staged
transition from the existing build.  GYP helped Chromium solve more
problems in less time than any of the other options that we
experimented with, but it's important to remember that Chromium's
needs are not necessarily the same as those of other projects.  There
are several valid ways to solve the "too many build systems" problem,
and GYP just happens to be one that has worked well for us.

Mark
(Full disclosure: I'm the principal designer of GYP, and would be
happy to discuss it in further detail)

Brent Fulgham wrote:
> So Cmake seems equivalent to GYP. GYP probably has unique features that make
> it more desireable than Cmake for one reason or another (perhaps it's easier
> to add new platform support or something), but at the moment those benefits
> are not obvious to me.
> I'm afraid that as far as I can tell, GYP seems like a case of NIH syndrome.