The first change here is swapping the isCompatibility and hasJvmDefault
checks. Otherwise behavior could be different depending on -Xjvm-default
mode even for non-JvmDefault declarations, which makes little sense.
Another change is avoiding generating $default stubs for fake overrides
in interfaces, which replicates the behavior of the current backend.
(Note that this change also fixes the first problem on the newly added
tests, but the first change seems useful anyway.)
Alternatively, we could improve the lookup utilities and their usages to
always find the exact override of a symbol from
Collection/Iterable/CharSequence/etc, but since we need to load the
original symbol anyway in cases when the loop subject's type is a type
parameter, we might as well simplify everything and always reference the
original symbol.
Also improve exception message and removed unused declarations in
IrBackendUtils.kt.
This corresponds to the ABI generated by the old backend. Moreover, when
compiling the module 'ir.tree' with JVM IR (could not reproduce on a
small sample), this led to a codegen crash when trying to reassign
parameter value to the default stub, which is an error expression and
can't be generated by ExpressionCodegen.
- introduce a scoped counter instead of a global one for name
generation for accessors. Naive solution not working.
- Introduced hardcoded "jd" suffix for accessors on interfaces, under
the assumption that the only such accessors are due to JvmDefault
and their bridges from `$DefaultImpls`. Removed all associated
templated tests, so the old and IR backend correspond on this matter
again.
- Respecialized writeFlags from regexps to string-equality: we are
going for exact matches now!
- Fixed package calculation in `IrUtils.kt`.
- Accessors for static members must be due to accessing super
classes. Actual super-qualified calls are naturally also accessing
super classes. Hence the `$s+{hashcode(superClassName)}`
suffix. Added test to affirm this naming scheme.
- Field getters/setters for static fields must be companion accessors,
otherwise just labelled as accessors. They are also tagged with `s`
suffix when accessing static fields.
- For naming of accessors to coincide with the old backend, field
renaming to avoid JVM signature clashes must be done _after_
generation of accessors for those fields.
Change the treatment of default implementations on interfaces in JVM
compatibility mode. Previously, the IR backend moved the actual
default implementation to the DefaultImpls class, and then bridged to
it from the interface default. The old backend did the reverse, at the
cost of an additional accessor, in order to gain better binary
compatibility properties. See #2612 for discussion.
The accessor needs to call a specific implementation, so must be
performed through an `invokespecial`. We trick the
SyntheticAccessorLowering into doing this for us, by marking the
bridging call as a super call. We do this in want of an explicit
`invokespecial` Ir Node.
InterfaceDefaultCallsPhase previously assumed the old behaviour of the
IR backend (that calls to default implementations, e.g. `foo$default`
should target `DefaultImpls.foo$default`). But now the bridge to
foo$default resides on `DefaultImpls` already, causing that pass to
create a recursive loop. We cut that loop with a simple check.
Had to edit some bytecodeText tests to account for the fact that JVM_IR
no longer generates explicit initializations for ConstantValue fields,
but NoConstantValueAttributeForNonConstVals is not the default yet.
Resolves the interaction of @JvmOverloads annotations and
parameterless main methods.
In the following code, both mechanisms generate methods that
ultimately produce the signature `public static void main(String[] args)`
of which there can be only one (true in general of any signature).
```
fun main() { }
@JvmOverloads
fun main(Array<String> args, x: Int = 42) { }
```
This PR simply shuffles the lowerings around, letting parameterless
main methods detect the presence of the default overload produced by
the annotation.
Additionally, this PR improves the testing of parameterless main
methods by actual bytecode patterns, and not simple check for
successful compilation (as @sfs and I discovered, there are issues in
flagging an error on duplicate signatures on the IR backend).
For example, a lambda `{ param -> captured }` of type `E.(T) -> U` will
be transformed by LocalDeclarationsLowering into a private static method
fun f$lambda-0($this: E, $captured: U, param: T) = $captured
The reason for such an ordering is that a lambda looks the same as a
local function, and local function can have default arguments, and those
arguments can reference captured variables; thus, captured variables
must come before actual declared arguments.
However, this is not the order that the inliner wants. Moreover, since
it was written to handle lambdas represented as `invoke` methods of
anonymous objects, it does not expect the actual callable method to have
any parameters corresponding to captured variables at all. This results
in it attempting to generate a temporary node with descriptor
(LE;LU;LT;LU;)LU;
while still using locals 1 and 2 as `param` and `$captured` respectively.
In the example above, this is not critical, as they both have reference
type and the lambda will eventually be pasted into a different node
anyway; however, if it happens that one of them is a primitive, or both
are primitives of different types, the bytecode will use incorrect
instructions, causing verification errors. The correct descriptor is
(LE;LT;LU;)LU;
This directory is skipped in JVM IR test generator, so they won't show
up as failed anymore.
Note that only failing tests are moved to oldLanguageVersions/. Tests
which already pass are still being run. It may be useful not to break
them in case we _do_ need to support some pre-1.3 language feature
switches in JVM IR.
Namely, anonymous objects defined in lambdas that have all captured
variables as loose fields instead of a single reference to the parent.
The question is, when a lambda inside an inline function defines an
anonymous object, and that object is not regenerated during codegen for
the inline function itself, but then has to be regenerated at call site
anyway, do we use an outer `this` or loose capture fields? For example,
before KT-28064:
inline fun f1(g: () -> Unit) = object { g() }
// -> f1$1 { $g: () -> Unit }
inline fun f2(g: () -> Unit) = f1 { object { g() } }
// -> f2$$inlined$f1$1 { $g: () -> Unit }
// f2$$inlined$f1$1$lambda$1 { this$0: f2$$inlined$f1$1 }
inline fun f3(g: () -> Unit) = f2 { object { g() } }
// -> f3$$inlined$f2$1 { $g: () -> Unit }
// f3$$inlined$f2$1$1 { this$0: f3$$inlined$f2$1 }
// f3$$inlined$f2$1$1$lambda$1 { this$0: f3$$inlined$f2$1$1 }
After KT-28064:
inline fun f2(g: () -> Unit) = f1 { object { g() } }
// -> f2$$inlined$f1$1 { $g: () -> Unit }
// f2$1$1 { $g: () -> Unit }
inline fun f3(g: () -> Unit) = f2 { object { g() } }
// -> f3$$inlined$f2$1 { $g: () -> Unit }
// f3$$inlined$f2$2 { ??? }
// f3$1$1 { $g: () -> Unit }
Should `???` be `this$0: f3$$inlined$f2$1` or `$g: () -> Unit`? This
commit chooses the latter for KT-28064 bytecode and keeps `this$0` when
inlining the old bytecode.
- Extract all backend codegen tests that specifically target behaviour
in to-be-deprecated functionality from language versions < 1.3"
- Remove those tests from the JVM IR test suite.
Given the strict pattern-matching in the inliner, this is the only way
to make it not crash when attempting to inline these stubs. Note that
the IR backend does not currently use the inliner's default method stub
handling; the crash only occurs when a module compiled with the non-IR
JVM backend is attempting to call an inline function with default
arguments defined in a module that was compiled with the IR backend.
NOTE: jvmCrossinlineLambdaDeclarationSite.kt is muted because the
inliner does not remap references to an anonymous object's parent
class after regenerating it. Unlike the JVM backend, JVM_IR uses the
top level named class' assertion status for all inner classes. (The
test used to pass because the lambda in `inline fun call` read the
`$assertionsDisabled` field of `CrossinlineLambdaContainer`, which
was not reloaded after changing the assertion status of package `test`.)
