[Development] [heads up] Build dependencies for the WebKit build on Windows

[Simon Hausmann]

Hi,

This is a heads-up regarding the build of WebKit on Windows:

Building WebKit on Windows always comes with the extra difficulty of having to 
install build support tools that don't come with the platform. The build makes 
heavy use of python and perl for automating the generation of various pieces 
of source code. In that context there are two changes coming up:

    1) For WebGL, CSS shaders and WebKit2 (GL TextureMapper) we do need to 
include the shader (re-)compiler of ANGLE in the build. The sources are part 
of WebKit (so no issue here), but the build requires a somewhat recent version 
of flex. Unfortunately the version of flex that the GnuWin32 project 
conveniently distributes with installers is too old to build the lexer of 
ANGLEs shader compiler. As a consequence I'm changing the dependency on 
Windows to another distribution of flex called Win Flex-Bison ( 
http://sourceforge.net/projects/winflexbison/ ). To keep things simple I'm 
adding a copy of the binary needed to qt5.git's gnuwin32\bin directory and 
will modify the WebKit build to pick it up automatically form there, if it can 
be found. If however for whatever reason you're building without qt5.git or 
otherwise see the build failing when it tries to call win_flex, then you need 
to install winflexbison and put it into your PATH.

    2) Due to changes in JavaScriptCore's non-JITted code path (1) the build 
is also soon going to require an installation of Ruby (2).



Simon

(1) http://lists.webkit.org/pipermail/webkit-dev/2012-September/022157.html

(2) That means the build will depend on Perl, Ruby and Python scripting run-
times. I personally find these rather main-stream and would like to see more 
exotic languages to be used for build assistance, such as Lua, Lisp or perhaps 
we can even find a use-case for BASIC :-)