This change improves the debugging experience around local functions
on the IR backend. The changes include moving old
checkLocalVariablesTable (cLVT) tests to the new stepping/local variable
infrastructure in order to refine the tests and further define the
behavior of the two JVM backends, and their differences.
The primary ported test case is cLVT/localFun.kt that documents the
discrepancy in implementation strategy for local functions on the two
backends. The old backend implements local functions as lambdas
assigned to a local variable while the IR backend lifts them out as
static funtions on the surrounding class. The discrepancies and their
consequences are documented in bytecodeListing, idea-stepping,
localVariableTable and debugStepping tests.
The only _code change_ is disabling the captured variable name
mangling for captured variables on the IR backend. Captured variables
are passed as arguments to the static function, so in the debugger,
they really just are local variables. For them to show properly in the
debugger and be detectable by evaluate expression, they simply need no
mangling.
Finally, this change cleans 3 redundant cLVT tests, copyFunction.kt
and destructuringInlineLambda.kt and destructuringInFor.kt, that are
all covered in the new suite. The stepping behavior needs to be made
precise around for loops, but that is an entirely seperate issue.
Reimplement the same hacky approach used in the old backend (see
cc2fe6b0c6).
Previously, the debugger incorrectly stepped into Collections.kt on
"step over" inline function calls from stdlib like 'any'.
Since `if` and `when` expressions are represented the same way in IR,
the behavior is fixed for both of them. It's not the case in the old JVM
backend, where stepping over `when` conditions still suffers from the
same problem, which the newly added test checks.
Loads of temporary variables that contain constants are replaced
with a copy of the constant. This avoids locals loads and stores.
However, the copy of the constant needs to have the offset of
the load and not of the original constant.
Fixes KT-41963.
Bytecode generated by JVM IR ensures that on multiline expressions,
every call is stepped over, which seems better than in the old backend.
Also remove kt34905.kt since it duplicates this test case.
Adds a synthetic line number just before the original function call.
The new line number is recognized by the debugger which replaces the
'step over' action with 'step into' and stops.
The main goal is to make behavior similar to what happens in Java. For instance, now we always skip lambdas.
Also, we can reliably use '$i$f' and '$i$a' synthetic local variables. There is no need in complicated hacks any more.
Mikhael Bogdanov