Invoke the game using MethodHandle

Currently the minecraft game provider invokes the game by using reflection. Reflection leaves a bunch of useless stack frames that will be present in most stacktraces given it’ll always be at the top.

MethodHandle stacktraces are hidden, therefore if loader would invoke the game using one of them it would prevent these useless frames from being printed to all those logs, crash reports or profiles.

I tried implementing this a while ago, but ran into an issue with proguard complaining about something, and I haven’t tried since.

Relevant code:

https://github.com/FabricMC/fabric-loader/blob/7c83b2604cd678bcb6dd29312e438cd09b8671ca/minecraft/src/main/java/net/fabricmc/loader/impl/game/minecraft/MinecraftGameProvider.java#L450-L452

[altrisi]

Yes, I know there is no performance benefit with this (even if the handle was made constant, I doubt it’d have any noticeable performance benefit anyway given, as you said, it’s only called once. Initializing it may even be more expensive than any potential optimization). The only reason I mentioned it is because of the stack reduction.

We don’t know if/when Mojang will update Java again, and if they don’t (which is likely at least until the next LTS), I think hiding those is quite nice. They’re just noise that gives no information.

Not only that, from some quick testing it seems like the implementation of JEP 416 still has some non-hidden frames (java.base/java.lang.reflect.Method.invoke and java.base/jdk.internal.reflect.DirectMethodHandleAccessor.invoke), while a MethodHandle implementation has none. Tested with the panama JDK 19 build.

[warjort]

Although proguard seems to think the bug is requiring a more precise warning, rather than the warning not being appropriate.

“ProGuard should probably provide a more accurate warning for this particular case. I’ll consider it. Your thoughts are welcome.”