[webkit-dev] Compiling WebKit up to 25% faster in Windows?

[Daniel Bratell]

Den 2013-03-26 19:21:32 skrev Daniel Bratell <bratell at opera.com>:

> As an experiment we took the (chromium) project webcore_dom, that  
> normally compiles in 56 seconds in Windows on a generic computer and  
> "fixed" it. Removing the many include paths in the build system and  
> instead specifying the path in the include directives changed that to 42  
> seconds, a 25% reduction.

I've looked some more at this today and it still looks promising.

On a Xeon W3550 (quad 3.06GHz), with plenty of RAM but a spinning disk and  
Windows 7:

webcore_dom: 58 seconds -> 38 seconds (-35%)
webcore_rendering: 106 seconds -> 73 seconds (-30%)
webcore_platform: 59 seconds -> 34 seconds (-43%)

(Yes, better than the 25% mentioned in the subject but this was on a  
different computer)

Just adding paths to the files cut a few percent of the compilation time.  
The big gain is from shrinking the list of include paths sent to the  
compiler. The data points reported here are the best times, but compile  
times were consistent over a number of attempts so now I trust them 100%.

There are some roadblocks though, and I wouldn't mind some pointers here.  
(This is my first deep dive into how the source generation/build system  
works in WebKit)

A lot of the source code, basically all WebCore projects I didn't list  
above, use files automatically generated by a number of massive perl  
scripts. The generated files include header files without any idea where  
they are. It would be good if they could generate something correct. Any  
suggestion there?

My easter celebrating colleague talked about trying the suggestion to  
symlink all headers in a single directory. I've not tried that though and  
I have no comparable data.

/Daniel