In the old backend, this was unnecessary because nested objects would
reference their lambdas' captures through the original this$0. On
JVM_IR, using loose capture fields means a name/descriptor clash can
occur on any level of nesting, not just the top.
Note that KT-30696 is fixed only in the single-module case, and KT-42012
is not fixed fully (see KT-44855).
#KT-30041
#KT-30629
#KT-30696
#KT-30933
#KT-32351
#KT-32749
#KT-38849
#KT-42012
#KT-42990
#KT-44234
#KT-44529
#KT-44631
#KT-44647
Not in the frontend or psi2ir, though, so this not a complete
implementation of KT-1436, but rather a part of it that is currently
useful to make other code compile. In particular, lambdas passed to
array constructors and JVM-style `assert` are inlined as IR returnable
blocks, which are then converted into `do { ... } while (false)` loops,
so non-local returns from them become non-local `break`s.
This is a hack to work around the fact that type mappings should not be
inherited by inlining contexts for lambdas called from anonymous
objects. As the lambda can call the inline function again, this could
produce a reference to the original object, which is remapped to a new
type in the parent context. Unfortunately, there are many redundant
`MethodRemapper`s between the lambda and the class file, so simply
editing `TypeRemapper` does not work. Hence, this hack. For now.
(Issue found by compiling IntelliJ IDEA BTW.)
If we do, the local variable table will not make sense. As as
example:
```
inline fun foo(getString: () -> String = { "OK" }) {
println(getString())
}
inline fun bar() {
}
fun main() {
bar()
foo()
}
```
leads to the following bytecode:
```
public static final void main();
descriptor: ()V
flags: ACC_PUBLIC, ACC_STATIC, ACC_FINAL
Code:
stack=2, locals=4, args_size=0
0: iconst_0
1: istore_0
2: nop
3: nop
4: iconst_0
5: istore_1
6: nop
7: ldc #53 // String OK
9: astore_2
10: iconst_0
11: istore_3
12: getstatic #30 // Field java/lang/System.out:Ljava/io/PrintStream;
15: aload_2
16: invokevirtual #36 // Method java/io/PrintStream.println:(Ljava/lang/Object;)V
19: nop
20: return
LineNumberTable:
line 9: 0
line 13: 2
line 10: 3
line 14: 4
line 15: 6
line 16: 7
line 17: 19
line 11: 20
LocalVariableTable:
Start Length Slot Name Signature
2 1 0 $i$f$bar I
6 14 1 $i$f$foo I
4 16 0 getString$iv Lkotlin/jvm/functions/Function0;
```
The `getString$iv` local should not be there. It has been inlined away.
Leaving it in the local variable table leads to inconsistent locals
info. Local 0 contains an int but we declare a local of type
Function0.
The main change here is in `JvmInlineClassLowering.visitFunctionAccess`,
where we now store the substituted return type of the function as the
type of the call expression. Without it, the call could have a
meaningless type, e.g. some `T` which is inaccessible at that place, and
that could backfire in subsequent lowerings in codegen. For example, in
the `stringPlus.kt` test, it would prevent the code in
`FlattenStringConcatenationLowering.isStringPlusCall` from recognizing
and replacing the `String.plus` call, leading to a codegen exception.
Other changes are mostly cosmetics to make the code similar to
`visitFunctionReference`, and preventive optimizations for the case when
the substitution map is empty.
The inline class is boxed when we pass it as lambda argument, now we
unbox it. If the underlying type is not Any or Any?, bridge method does
the unboxing.
#KT-32450 Fixed
#KT-39923 Fixed
#KT-32228 Fixed
#KT-40282 Fixed
When a suspend lambda does not capture crossinline lambda, it is
generated with as state-machine, since it does not inline anything.
However, when regenerating, the inliner used to remove all DebugMetadata
annotations to avoid duplication. This lead to missing annotation if
the lambda is regenerated, but state-machine is not regenerated.
This change fixes the blind spot by readding the annotation after
regeneration.
#KT-41789 Fixed
In box tests, only check that Java reflection does not crash on the
EnclosingMethod attribute generated in these classes. If it doesn't
crash, most likely it returns the value that can be read from the class
file by ASM, which is what the newly added bytecode listing tests are
checking now.
All tests on anonymous objects should use the NO_CHECK_LAMBDA_INLINING
directive, since the test framework can't tell an anonymous object from
a lambda and checking that anonymous objects are "inlined" makes no
sense.
In 1.3.x, for inline class member inline vals 'getFoo-impl' method was
generated in corresponding inline class.
Since 1.4.0, getters for properties returning inline class values are
mangled (so corresponding getters are named 'getFoo-<mangling_hash>'.
However, to maintain backward compatibility with libraries compiled with
1.3.x, inliner should be able to find 'getFoo-impl' method in the
bytecode.
Jinseong Jeon