Instead of generating these annotation classes as package-private on
JVM, serialize their metadata to the .kotlin_module file, and load it
when compiling dependent multiplatform modules.
The problem with generating them as package-private was that
kotlin-stdlib for JVM would end up declaring symbols from other
platforms, which would include some annotations from package
kotlin.native. But using that package is discouraged by some tools
because it has a Java keyword in its name. In particular, jlink refused
to work with such artifact altogether (KT-21266).
#KT-38652 Fixed
Since LocalDeclarationsLowering is a BodyLoweringPass, local
functions inside one declaration are handled independently of local
functions in the other declaration. This can lead to name clashes, in
case a local function with the same name and signature is declared in
overloads in the same container, which results in a signature clash
error in JVM IR.
The issue became more common with the introduction of adapted function
references, where psi2ir generates a local adapter-function with a
predefined name, which can easily clash with another reference to the
same target in an overload. This led to a compilation error when
bootstrapping Kotlin with JVM IR, for example in GradleIRBuilder.kt
where there are a lot of references to the same function.
comparisons.
Having those conversions leads to unnecesary boxing and null checks.
This change does it only for JVM in the optimization lowering. It
is unclear to me if the other backends can get away with something
similar.
The reason for this is that this flag is used right now in 'cli-common'
to workaround the problem that this module is compiled with API version
1.4, but runs with stdlib of version 1.3 (bundled to Gradle). The same
problem would appear with adapted function references, since we use
kotlin/jvm/internal/AdaptedFunctionReference in the bytecode, only
available since 1.4.
The fix is to generate adapted references in this case as subclasses of
the already existing kotlin/jvm/internal/FunctionReference. This can
change behavior in some extreme corner cases (because such references
can now be observed to have reflection capabilities), but it's an -X
argument anyway.
Another option would be to introduce another compiler argument
specifically for this, but it looks like it would only complicate things
without much benefit.
Mark Punzalan