This solves no immediate deficiency, but is a to-do that arose as part
of an ongoing effort to port the old, slightly too restrictive
checkLocalVariableTable tests to the more "functional" debugger
infrastructure.
This just shaves a little bit of overhead off the test expectations
and couples them less tightly to the specifics of the test
infrastructure.
Reveals discrepancy in LVT presence on lambda implementations on the
old and new backend.
The generated code in the constructors of Suspend Lambda objects is
identical, but the IR backend generates an LVT with the constructor
parameters.
The user has to be very insistent to see this ("for step into" +
disabling "Show only kotlin variables"), but it is an observable
difference.
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 debug experiece of destructuring patterns in lambdas is different
across the two backends due to the IR backend moving local variables
to fields.
However, since the destructuring variable is never actually visible in
the debugger (no linenumbers in the live range of the variable), and
the variable is never used for anything other than hiding it from the
debugger, we propose that it is not actually necessary to include it
in the LVT (and in fact, could be left out of the LVT on the old
backend).
This commit unifies the expectation format between the stepping and
LVT tests in the new debugging test harness.
Furthermore, it introduces a compression of runs of locations without
linenumbers. These default to showing as bytecode offsets from
previous line number, which overspecifies the tests: the bytecodes
chosen should not be constrained by a debugging step test.
This commit enables the execution of suspend box tests in a separate
test. It's a QoL improvement in the existing bb tests but, motivating
these changes, enables the new debugger stepping tests to step
coroutine code.
Ilmir Usmanov