[webkit-dev] What goes in FeatureDefines.xcconfig

[Michael Catanzaro]

On Mon, Dec 10, 2018 at 5:49 PM, Don.Olmstead at sony.com wrote:
> Recently I did some work around syncing the contents of 
> FeatureDefines.xcconfig and WebKitFeatures.cmake, 
> https://bugs.webkit.org/show_bug.cgi?id=191167 . Michael mentioned 
> someone noticing that ENABLE(RESOURCE_LOAD_STATISTICS) didn’t end 
> up in that list. I did some digging and saw that it ended up in 
> Platform.h, https://bugs.webkit.org/show_bug.cgi?id=189959 . So what 
> I’m wondering is what is the criteria for something being in 
> FeatureDefines.xcconfig and whether ENABLE_RESOURCE_LOAD_STATISTICS 
> meets it

I just found wtf/FeatureDefines.h. Didn't know this existed.

Good grief, we have quite a mess here. Define your features in 
WebKitFeatures.cmake, FeatureList.pm, twenty FeatureDefines.xcconfig 
files, Platform.h, FeatureDefines.h....

I think we can get rid of FeatureDefines.h and the vast majority of the 
defines in Platform.h. (I guess some will need to be kept where the 
logic required is more than a simple boolean, too complex for XCode.) 
WebKitFeatures.cmake and FeatureDefines.xcconfig we are stuck with, 
because those are needed for users to be able to configure the build. 
Then FeatureList.pm is questionable. It's a convenience to be able to 
easily pass flags to build-webkit, but this can also be done at the 
CMake or XCode levels, and I don't think it's worth the cost at all. So 
ideally we would have just WebKitFeatures.cmake and the 
FeatureDefines.xcconfig family of files that have to be manually kept 
in sync.

...unless am I missing something? Thoughts?

Michael