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.
The existing backend restores LVs and parameters from the suspend lambda
fields used for spilling between suspension points, hence they are
visible in the debugger as local variables, plain and simple.
This PR introduces the same pattern to the IR backend, to bring the
debugging experience in line with the existing backend.
Both backends are still at the mercy of the liveness analysis
performed in the coroutine transformer where a liveness analysis
minimizes live ranges of entries in the LVT. E.g. an unused parameter
will be dropped entirely.
Adjusted existing test expectations accounting for the differences in
LV behavior.
The current backend does that for some bridges. We do it consistently
for all bridges.
The line number used differs. For the JVM_IR backend, we use the
line number of the class to which the bridge is added. For the
JVM backend, that does not appear to be the case for bridges
in lambdas. I prefer the line number for a lambda invoke bridge
to be the line for the lambda instead os some surrounding class.
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.
This fixes smart step into for delegated member functions.
Additionally, we align on the string "memberFunctionName(...)"
for expression non-null checks for both JVM_IR and JVM
backends.
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.
The only difference seems to be that step into IImpl.fooOverride is
actually supported in JVM_IR. Also fix slightly incorrect line numbers
in the comments.
The difference is that JVM_IR generates line numbers for the
constructor field initialization.
In this case:
```
29: class B {
30: // comment
31: val bPropVal: Int,
32: // comment
33: var bProbVar: Int
34: ) {
```
the line numbers for the field initializations are 31 and 33 where
in the current backend the whole constructor has line number 29.
JVM_IR has consistent stepping behavior for secondary constructors
and init blocks. This change fixes the expectations for tests that
expect the less consistent JVM backend behavior.
Temporary variable loads in when expressions had the offsets
of the variable declaration. That leads to hacks during codegen
for line number generation.
Instead of those hacks, give the variable loads the offsets of
the context in which they occur. That avoids the codegen hacks
and fixes stepping behavior for more when expressions.
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.
Note: neither the new nor the old data is actually correct, as the
debugger needs to stop on line 7 twice (once for the call, once for the
lambda) but ignore the synthetic line number in between.
Ilmir Usmanov