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.
Don't mangled functions annotated with @JvmName.
Annotate 'Result.success' and 'Result.failure' with @JvmName and
@Suppress("INAPPLICABLE_JVM_NAME").
NB this would require bootstrap.
If an inline parameter has a default value, its type is nullable.
There's already code to handle this in `IrInlineCodegen`, but it
really should be in `isInlineParameter` instead, otherwise e.g.
SyntheticAccessorLowering fails.
A follow-up for KT-35006:
fun f() = foo {
bar()
}
inline fun foo(crossinline x: () -> Unit) = { x() }()
inline fun bar() = TODO()
does not provide the option to navigate to bar's call site at all.
* a writing source mapper has `mapLineNumber(line, file, class)` that
inserts a new SMAP entry and returns a fake line number from it;
* a copying source mapper has `mapLineNumber(line)` that uses an
existing SMAP to resolve the line number and call the former method
on a different source mapper;
* those two types are disjoint.
When we inline an anonymous object which captures something such as
crossinline values or reified parameters, we copy and transform its
metadata in `AnonymousObjectTransformer.transformMetadata`. Basically we
read the metadata of the original class, add a minor protobuf extension
and write it to the new class.
This also includes copying the string table. We read the string table
into `JvmNameResolver` (a representation of string table used in
deserialization), then construct a `JvmStringTable` (a representation
used in _serialization_) and then write it back.
There's a few optimizations in the string table representation in JVM
metadata which allow to store less strings and thus take less space. See
`StringTableTypes.Record` in `jvm_metadata.proto` for more information.
One of the optimizations `Record.range` allows to avoid storing the same
record many times in a sequence. For example, if we have N different
strings in the string table but none of them require any operation (such
as substring, char replacement, etc.), then we only store the record
with all default values (no operation, no predefined string, etc.) and
set its `range` to N. Upon reading such optimized record list in
`JvmNameResolver`, we "expand" it back to normal, so that we could index
it quickly and figure out what operation needs to be performed on each
string from the string table.
The problem was that when we expanded this list, we didn't set the range
of the expanded record entry to 1. So each record in
`JvmNameResolver.records` still has its original range. It doesn't cause
any problems most of the time because the range in this expanded list is
almost unused. However, when copying/transforming metadata for anonymous
objects, we mistakenly passed this expanded list with incorrect ranges
to `JvmStringTable`. So the metadata in the copied anonymous object
ended up being incorrect: each record now was present the number of
times equal to its range. Copying such metadata once again led to
another multiplication of the record list size. Multiple copies resulted
in exponential increase in memory consumption and quickly led to OOM.
For the fix, we now take the original, unexpanded list of records when
creating `JvmStringTable` out of `JvmNameResolver` for transformation of
anonymous object metadata.
Note that another possible fix would be to make range for each record in
`JvmNameResolver.records` equal to 1. This is undesirable though, since
then we'd need to copy each `JvmProtoBuf.StringTableTypes.Record`
instance, of which there could be many, and use some memory for no
apparent gain (since ranges in that expanded list are now not used at
all).
#KT-38197 Fixed
In general, `InliningContext.findAnonymousTransformationInfo` was not
reliable because it mapped each type to *some* info for that type,
preferring ones with `shouldRegenerate == true` if those exist. Thus, it
returned incorrect results if one type was regenerated multiple times,
e.g. in a nested inlining context or because of a `finally` (which
duplicates anonymous objects). The solution is to avoid a global map and
attach the current transformation info directly to the current inlining
context.
Alexander Udalov