Allow identification of OSLogMessage by a @_semantics attribute instead of just name

[kubamracek]

OSLogOptimization currently special-cases the type name "OSLogMessage" and applies special treatment to it (skips over synthesized witness methods). Let's allow explicitly annotating types with @_semantics("oslog.message.type") to trigger the same treatment. This will be useful for custom implementations of OSLog-like APIs.

rdar://83325012

[ravikandhadai]

@kubamracek Thanks Kuba for making the PR. Is semantics attributes now possible on types?

[ravikandhadai]

I wonder if it may be better to rename the OSLogMessage type in the OSLogTestHelper module apply this semantics attribute. This may enable testing this change.

[kubamracek]

Semantics attributes on types were added via 454dd00, yes.

[kubamracek]

I wonder if it may be better to rename the OSLogMessage type in the OSLogTestHelper module apply this semantics attribute. This may enable testing this change.

I tried that, and it ended being a bit invasive on the code OSLogTestHelper. Let's see if you prefer that, but I can also perhaps revert and switch only the AnimationFormatString.OSLogMessage type, which can be done as a minimally invasive change.

[kubamracek]

@swift-ci please test

[swift-ci]

Build failed
Swift Test OS X Platform
Git Sha - 3a74ea5d87183256e18bee93d048d3551691943d

[kubamracek]

@swift-ci please test

[kubamracek]

@ravikandhadai This is what only changing the type name on AnimationFormatString.OSLogMessage looks like: kubamracek@668b204

Let me know if you'd prefer that.

[ravikandhadai]

@ravikandhadai This is what only changing the type name on AnimationFormatString.OSLogMessage looks like: kubamracek@668b204

Let me know if you'd prefer that.

Yes. Changing AnimationFormatString.OSLogMessage instead of the OSLogMessage type sounds great. Thanks Kuba!

On a slightly different note, if you are only interested in converting a string interpolation to a static format string and not very concerned about optimizing varargs lmk. There is a very small design change possible on the client side, compared to the current implementation of OSLogMessage and os_log, that would enable creating a very general custom string interpolation type that can be used in any context and create a static format string.

[kubamracek]

@swift-ci please test

[kubamracek]

On a slightly different note, if you are only interested in converting a string interpolation to a static format string and not very concerned about optimizing varargs lmk. There is a very small design change possible on the client side, compared to the current implementation of OSLogMessage and os_log, that would enable creating a very general custom string interpolation type that can be used in any context and create a static format string.

I'm not sure, TBH. Maybe @Catfish-Man does?

[Catfish-Man]

I'm not sure either tbh. It sounds interesting at least!

[kubamracek]

@swift-ci please test Windows platform

[ravikandhadai]

LGTM!

[ravikandhadai]

I'm not sure either tbh. It sounds interesting at least!

No worries. Feel free to cc me on the PR you create for that.