Example: if C is a Kotlin class and there is an import of C.Companion.f,
a call to f will need to check if it is a constructor, for which
it will attempt to load C.Companion.f as a Java class. This involves
loading all outer classes, including C itself, as BinaryJavaClass - see
KotlinCliJavaFileManagerImpl - despite the fact that C and C.Companion
have both already been loaded from their Metadata annotations as Kotlin
classes, wasting cycles and polluting caches.
Thus the theoretical motivation for this change is to marginally speed
up FIR.
The real motivation is that with the -Xemit-jvm-type-annotations option,
kotlinc sometimes generates invalid annotations, and reading them with
BinaryJavaClass throws an exception (the Kotlin metadata however is
valid):
// MODULE: lib
// FILE: C.kt
// The constructor has an argument of type
// List<? extends Function1<? super String, Integer>>
// and a ParameterName type annotation with path
// TYPE_ARGUMENT(0), TYPE_ARGUMENT(0)
// which is missing a WILDCARD between the two TYPE_ARGUMENTs
class C(val x: List<(name: String) -> Int>) {
companion object {
fun foo() {}
}
}
// MODULE: main(lib)
// FILE: main.kt
import C.Companion.f
fun bar() = foo() // crashes FIR
The parameter annotation should obviously be fixed too, but invalid
bytecode may already exist in the wild. Also, did I mention that this
change marginally speeds up FIR?
pyos
ecdd80769e