1. if an argument of a `pop` cannot be removed, then all other potential
arguments of that `pop` can't be removed either, and the same applies
to other `pop`s that touch them;
2. the same is true for primitive conversions, but this is even trickier
to implement correctly, so I simply did the same thing as with
boxing operators: replace the conversion itself with a `pop` and keep
the argument as-is.
Somehow this actually removes *more* redundant primitive type conversions
than the old code in a couple bytecode text tests, so I've patched them
to kind of use the value, forcing the instructions to stay.
#KT-46921 Fixed
CoroutineTransformermethodVisitor attempts to extend the ranges
of local variables in various situations. Probably in an attempt
to give a better debugging experience. However, all of these
range extensions lead to invalid local variable tables where
something is in the local variable table where nothing is in the
corresponding slot.
The code that extends variables to the next suspension point
instead of ending them when they are no longer live has issues
with loops. When resuming and reentering the loop, the locals
table will mention a local that we did not spill and which
is therefore not restored when resuming.
The code that extends local variable table entries if there
are no suspension points between two entries doesn't work
for code such as:
```
var s: String
if (suspendHere() == "OK") {
s = "OK"
} else {
s = "FAIL"
}
```
If the local variable ranges are collapsed into one, one of
the branches will have the local defined in the local variable
table before the slot is initialized.
Old compiler versions still won't be able to load default lambdas
generated by JVM_IR, but this way we avoid incorrect behavior of
function references taking inline class types that unbox to Any.
#KT-46601 Fixed
Also, produce more correct results in IrDefaultLambda's
`invokeMethodParameters` and `invokeMethodReturnType`. This affects
whether the inliner inserts inline class boxings/unboxings around lambda
calls; while this doesn't matter now due to KT-46601, it would if the
naming was fixed.
The coroutine transformation would leave locals in the local
variable table across the code that reloads local variables from
the continuation on reentry. However, when reentering the function
the local has no value until after the reloads from the
continuation.
This change splits the locals in the local variable table to
avoid such uninitialized locals. A local alive across a
suspension point has its range split in two. One that goes
from the original start to the state label for the restart
after the suspension. The other goes from after the local
has been reloaded from the continuation until the previous
end of the local.
Also, do not try to use invokedynamic on SAM calls with intersection
types, because intersection type is not allowed as an immediate type
projection of a supertype, and constructing a fake override in
LambdaMetafactoryArgumentsBuilder led to an exception. This fixes the
problem which was worked around earlier in e6c089ef, effectively
reverting that commit.
The main motivation for this change is that LambdaMetafactory also
doesn't generate generic signature for SAM wrapper classes at runtime.
Since these classes are synthetic, nobody should rely on the fact that
they have generic supertypes, which was observable only via Java
reflection.
#KT-46149 Fixed
#KT-46238 Fixed
Coroutine transform would occasionally *extend* the range of a
local instead of shrinking it (if the next suspension point
is after the end point for the local). That leads to the local
variable table having a local that covers code where it is not
defined. That is invalid and leads to D8 removing the locals
table from the code.
Commonize (in terms of TypeSystemCommonBackendContext implementations
for KotlinType/IrType) code that computes optimal TypeMappingMode to
apply to different positions where inline class types can be present.
KotlinTypeMapper.mapInlineClassTypeAsDeclaration and
mapUnderlyingTypeOfInlineClassType invoked mapType which is defined in
descriptorBasedTypeSignatureMapping.kt and works on KotlinType.
It didn't lead to any problems, other than the fact that we were
constructing IrBasedClassDescriptor in JVM IR, and then KotlinType to
pass it to mapType, on each call to StackValue.boxInlineClass or
unboxInlineClass, which seems wasteful.
Instead of this, refactor these utilities to use type markers instead,
pass IrType and IrTypeMapper directly from JVM IR, and move the "static
type mapper" logic (which is used only in the old backend) out of
KotlinTypeMapper.
When a suspension point is inlined, the inlining local spans
unspilling code where the local slot has not been initialized.
The transformer already inserted initialization code for the local,
however, it did not split the local variable table. Therefore,
the inlining local is defined on instructions where the local
slot has no value (namely the instructions that initialize
the local slot on the unspilling path).
This change adds splitting of the local variable table as well.
When updating to a new version of D8, the uninitialized local
slot showed up. D8 will repair it in this case, but it is
better to not generate such code.
pyos