Any access to a function from a multi-file part needs to be replaced
with the access to the corresponding public method (if it exists) from
the facade class. Note that this has no immediate effect because we use
KotlinTypeMapper for mapping calls, and it understands that a call to a
function from the part must actually be generated into a call to the
function from the facade in the bytecode. This commit merely changes the
IR to better reflect what's generated in the final bytecode, and to be
able to use simplified IR-based method signature mapping instead of the
legacy KotlinTypeMapper in the future.
Note: this currently results in invalid IR (but valid bytecode) if the
@JvmStatic function is imported, because its IR representation is
unlowered and therefore has a dispatch receiver, but the call will not.
Previously it was linear scan, failing on unbalanced suspension markers.
Now, I use CFG to find end markers, which are reachable from start
markers. Using CFG allows to walk through suspension point instructions
only, since they form region.
If, for some reason, end marker does not exist (inliner or unreachable
code elimination pass remove unreachable code) or is unreachable,
just ignore the whole suspension point, as before.
#KT-33172 Fixed
#KT-28507 Fixed
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.
Unlike previously, this optimisation works on every callee return type.
Tail-calls inside unit functions can be either
INVOKE...
ARETURN
or
INVOKE
POP
GETSTATIC kotlin/Unit.INSTANCE
ARETURN
The first pattern is already covered. The second one is a bit tricky,
since we cannot just assume than the function is tail-call, we also need
to check whether the callee returned COROUTINE_SUSPENDED marker.
Thus, resulting bytecode of function's 'epilogue' look like
DUP
INVOKESTATIC getCOROUTINE_SUSPENDED
IF_ACMPNE LN
ARETURN
LN:
POP
#KT-28938 Fixed
re-ordering the lowering phases.
The changes in InterfaceLowering are necessary so that IrElements that
target the removed functions are re-targeted to the new functions in
DefaultImpls. This affects local functions in interface functions since
now LocalDeclarationsLowering comes before InterfaceLowering.
It uses isStaticMethod to determine whether to set ACC_STATIC, which is
not correct (see PR #2341). This results in using incorrectly typed
opcodes (as all arguments are shifted by 1) when modifying the inlined
lambda's bytecode. For example, in the test added by this commit, these
opcodes are inserted to spill the stack into locals before calling
another inline function.
Because getMethodAsmFlags is used by the non-IR backend (see PR #2341
again for why changing stuff might not be a good idea), the proposed
solution is to ditch it completely and override generateLambdaBody in
IrExpressionLambdaImpl to use FunctionCodegen's IR-based flag
computation logic.
in OUTERCLASS field.
The inliner generates two versions of suspend functions/lambdas in
inline functions: with state-machine and without. The former is used
to call the function from Java or via reflection and have ordinary
name, while the latter is used by inliner and have $$forInline suffix.
The inliner throws the state-machine version away, duplicates
$$forInline version and then call state-machine generator.
If these suspend functions/lambdas are not going to be inlined,
$$forInline version is not generated. However, all objects, which are
used in these suspend functions/lambdas, have $$forInline version
written to OUTERCLASS field. This leads to errors by proguard.
Since they are used in both state-machine version and for-inline ones,
we can simply remove $$forInline suffix from OUTERCLASS field and this
fixes the issue.
#KT-31242 Fixed
if they are not inlined, but directly called.
Previously, all inline and crossinline lambda calls were treated by
codegen as if they are always going to be inlined. However, this is not
always the case.
Note, that we cannot generate these markers during codegen, since we
can inline code with no suspension points, but the whole inlined code
will become one giant suspension point. This, of course, breaks
tail-call optimization and, hence, slows down cold streams.
Because of that, we generate these markers, when we are sure, that they
are not going to be inlined. The only place, in which we know that, is
the inliner. During inlining of the inline function, we check, whether
the parameter is inline or crossinline and whether it is not an inline
lambda. If these checks pass, we generate the markers. Noinline
parameters are already covered by the codegen.
#KT-30706 Fixed
#KT-26925 Fixed
#KT-26418 Fixed