Bug 37102

Summary:	DerivedSources.make does not notice when FEATURE_DEFINES change
Product:	WebKit	Reporter:	Eric Seidel (no email) <eric>
Component:	Tools / Tests	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	abarth, darin, ddkilzer, mjs, mrowe
Priority:	P2
Version:	528+ (Nightly build)
Hardware:	All
OS:	All

Description Eric Seidel (no email) 2010-04-05 11:47:18 PDT

DerivedSources.make does not notice when FEATURE_DEFINES change

This caused:
https://bugs.webkit.org/show_bug.cgi?id=36961#c21

One possible solution would be for DerivedSources.make to write out some sort of FEATURE_DEFINES file in DerivedSources/ during a build, and then if the incoming FEATURE_DEFINES are ever different from that file, simply rebuild everything.

Comment 1 Maciej Stachowiak 2010-04-05 22:17:22 PDT

Sounds like a good idea to fix this.

Comment 2 Darin Adler 2010-04-06 08:35:20 PDT

I think this is critical to fix. I personally would fix it by eliminating FEATURE_DEFINES and using a file instead of an environment variable to communicate these settings. The build-webkit tool could generate the header file.

Comment 3 Darin Adler 2010-04-06 08:35:43 PDT

But I suppose the file would need to be a format that multiple tools could read, so perhaps it's impractical.

Comment 4 Eric Seidel (no email) 2012-05-14 14:21:15 PDT

I wonder if this old bug is still valid.  If it is, I wonder if landing bug 85456 will give us an easy way to fix it. :)