Cocoa availability macros are not working for non-WebKit sources on buildbots After running configure-xcode-for-embedded-development, the Cocoa WebKit OpenSource SDK is left in following state: - Correct code does not build with the WebKit OpenSource SDK - Incorrect code builds with the SDK, but does not build on real, unmodified SDK This is because WebKit erases the availability macros from the SDK. Consider case: enum A { CommonOption, MacOSOption API_UNAVAILABLE(ios) }; bool correctFunc(A a) { switch (a) { case CommonOption: return true; #if defined(TARGET_OS_MAC) case MacOSOption: return false; #endif } } bool incorrectFunc(A a) { switch (a) { case CommonOption: return true; case MacOSOption: return false; } } bool incorrectAndConfusingButCompilingFunc(A a) { switch (a) { case CommonOption: return true; #if defined(TARGET_OS_MAC) case MacOSOption: return false; #endif default: UNREACHABLE(); return false; } } - correctFunc does not compile on WebKit SDK. This the bug we want to fix. - WebKit code needs to use incorrectFunc. This is the bug we want to fix. - incorrectFunc does not compile on unmodified SDK. This is the feature we want to preserve. This becomes a problem when contributing to ANGLE: - If we contribute incorrect code to ANGLE, it doesn't compile for the rest of the world. - If we contribute correct code to ANGLE, it doesn't compile for WebKit. - Currently we have to use the workaround incorrectAndConfusingButCompilingFunc