Bug 212444 – New build system causing full WebCore recompiles

• Component: Tools / Tests
• Status: RESOLVED DUPLICATE

[Kenneth Russell]

Created attachment 400403 [details]
zip archive of build output

After the switch to the new build system, touching a single .cc file in for example Source/ThirdParty/ANGLE and running:

./Tools/Scripts/build-webkit --release --ios-simulator > build-log.txt 2>&1

seems to cause some timestamp in JavaScriptCore to be modified, causing headers to be regenerated, and a lot of WebCore to be rebuilt.

Attached is the (aborted) output after touching Source/ThirdParty/ANGLE/src/libANGLE/formatutils.cpp and running that command. (WebKit was completely built in this configuration before touching that file and attempting a rebuild.)

This drastically increases incremental build times and basically destroys our ability to contribute to WebKit. Can this regression please be investigated?

[Radar WebKit Bug Importer]

<rdar://problem/63696405>

[Kenneth Russell]

Note: I might have broken something in Bug 212428.

[Kenneth Russell]

Undoing my change to WebKit.xcworkspace/xcshareddata/WorkspaceSettings.xcsettings from Bug 212428, touching a file in Source/ThirdParty/ANGLE and running:

./Tools/Scripts/build-webkit --debug --ios-simulator

still does a huge rebuild of lots of JavaScriptCore, WebCore, and WebKit. Incremental builds aren't working any more in WebKit.

[Kenneth Russell]

The switch to XCBuild was reverted in Bug 212530 so reducing the priority to P2, Major. Keith, may I assign this to you to follow up on later? I can help fix ANGLE so that it doesn't regenerate its headers all the time (originally fixed in Bug 199212, but seems it will need a new solution that doesn't generate a timestamp but is instead based on the file's contents).

[Keith Rollin]

*** This bug has been marked as a duplicate of bug 217371 ***