Generate $delegate method as instance method in
PropertyReferenceDelegationLowering, and remove dispatch receiver later
in MakePropertyDelegateMethodsStatic. The method needs to be static to
be non-overridable (see delegateMethodIsNonOverridable.kt), and public
to be accessible in reflection.
Otherwise we generated incorrect IR where a static function accessed an
instance field of the containing class, which failed in multiple places
including LocalDeclarationsLowering.
#KT-48350 Fixed
Before this commit, we cached such IR properties by FIR property
which was created by Java field each time when we referenced it.
This led to signature clashes. Now we cache such IR properties
directly by associated FIR field.
The "free" in "createFreeFakeLambdaDescriptor" and such refers to the
fact that there are no references to type parameters from outside the
current declaration. This is necessary because at the point where the
metadata is written, the type parameters may not even be in scope (e.g.
local delegated properties are serialized at class level, but may refer
to function-scope type parameters).
Without the `-Xmultifile-parts-inherit` mode for now.
This is implemented as follows: FileClassLowering collects information
about multifile parts and the corresponding facades, which a later
GenerateMultifileFacades phase uses to generate new IrFile instances and
add it to the module fragment that's being compiled.
Note that GenerateMultifileFacades is in the end of lowering phases
because delegates in the facade should be generated for all additional
functions generated by certain lowerings (default arguments,
JvmOverloads, etc.). If GenerateMultifileFacades was right after
FileClassLowering, they would still be generated, but we'd then process
them in lowerings mentioned above, which would result in duplicated
logic in the bytecode. There's a new bytecode text test which checks
that this doesn't happen for functions with default arguments.
Delegated properties now have their $delegate fields recorded in the
metadata (in `ClassCodegen.generateField`). This part of metadata is
used by `KPropertyN.getDelegate` functions, so almost all tests on
getDelegate are now unmuted
* In blocks, discard the result of any statement that has a return
type other than void. This was previously done by wrapping each
statement into an "implicit Unit conversion" that was actually
compiled down to a stack pop instead. If an expression happened to
already have type Unit, however, such a conversion was not inserted,
resulting in a stray reference on the stack. These conversions are
now redundant and should probably be removed.
* In assignments and non-exhaustive conditionals, materialize a Unit
on the stack to avoid depth mismatches that trip up the bytecode
validator. Because such expressions are generally used at block level
(and, indeed, the frontend will reject a non-exhaustive conditional
used as an expression), combined with the above change this results
in no additional GETSTATIC opcodes, as they are immediately removed
by the peephole optimizer.
Introduce MetadataSource as a way to store the original descriptor for
any element (before any lowerings) and maintain it until the end of the
codegen where it's used in generating the metadata. Note that JVM
signatures written to the metadata are formed from the _resulting_
generated elements, not by mapping the original descriptors.
Some corner cases are not supported yet, namely properties declared in
companion objects, synthetic methods for property annotations,
JvmPackageName, etc.
#KT-29119 Fixed
IrDeclarationOrigin.FILE_CLASS is used in CallableReferenceLowering to
generate correct declaration owner.
Many reflection tests start to fail with this commit because they are
now treating callable references to top level declarations as Kotlin
symbols and fail because there's no JVM signature for them; this is
fixed in subsequent commits (previously, they worked because without
Kotlin metadata, these files were treated as Java classes)
The problem was that in JvmSerializerExtension.writeLocalProperties, we
only serialized metadata for local properties, but indices generated in
MemberCodegen.generatePropertyMetadataArrayFieldIfNeeded were among all
delegated properties in the class (not only local). This behaved
incorrectly as long as there was a local and a non-local delegated
property in the same class. For example, if there were 5 non-local
properties and then one local, that local property would get the index 5
and the synthetic signature "<v#5>". But there would only be one
Property entry in the metadata, and so reflection would fail here trying
to load the 5th element of the list which contains only one element.
Now, the index for a local delegated property is computed only as the
number of _local_ delegated properties above it in the class, i.e. the
first local delegated property gets index 0 (and synthetic signature
"<v#0>"), the next one -- index 1, and so on.
#KT-23413 Fixed
Alexander Udalov