The parameter, unlike other ones, should span the whole method, since
throughout the whole method it has some value and thus should be
visible.
This effectively rolls bb5a99ec back
#KT-64309 Fixed
Locals introduced in the body of a do-while loop are not
necessarily live at the do-while condition. For example,
if there is a continue in the body before the declaration:
do {
if (shouldContinue(x))
continue
val y = 32 // not always defined in the condition
doSomething(y)
} while (x < 2)
For locals referenced in the condition such code is rejected
by the frontend because a local referenced in the condition
must be always defined when you get there.
However, locals that are not used in the condition were always
put in the local variable table. This leads to invalid locals
information which can trip of debuggers and other build tools
such as the D8 dexer.
This patch only puts in locals information for locals actually
referenced in the local variable table for the condition.
^Fixes KT-51754
We are going to deprecate `WITH_RUNTIME` directive. The main reason
behind this change is that `WITH_STDLIB` directive better describes
its meaning, specifically it will add kotlin stdlib to test's classpath.
Putting them in the local variable table means that the debugger
needs to have special handling for parameters with specific names.
That forces us to generate mangled names for these.
Instead of also implementing the name mangling for FIR, this
change gets rid of the parameters from the LVT instead.
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.
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.
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 is the first step in a push to improve the test coverage of the
IR debugging experience. This commit improves on the sketch of local
variable table tests built on the new debugger stepping
infrastructure. As improvements on the existing
checkLocalVariableTableTest they:
- don't overspecify codegen strategy: no hard requirements on slots.
- test the observed lifespans of locals by stepping through code.
Ultimately this should enable us to bring over all existing tests for
improved coverage of both old and new JVM backends.
WIP list:
- Gracefully handle absent LVT: treat as empty Add type of local and
- type of value stored there to expectations Print values in local
- slots if primitive or java.lang.String Enable specifying
- expectations per backend Gracefully handle absent box methods
- Gracefully handle null values in slots of reference type
- Port a first LVT test
AbstractCheckLocalVariablesTableTest and fix
`checkLocalVariablesTable/localFun.kt` for JVM IR.
Also improved diagnosability of CheckLocalVariablesTableTest failures.
CheckLocalVariablesTableTests will now check the validity of
the locals table against types of locals computed based on the
bytecode.
These checks and the new destructuringInFor test act as a
regression test for the changes in
https://github.com/JetBrains/kotlin/pull/2613
These checks also caught a similar issue for destructuring
lambda parameters, where the local is introduced before the
value has been written to the local slot. This change also
fixes that.
Finally, this change fixes the asmLike tests to correctly
look up the name of parameters in the locals table.
This fixes slice rewrite stacktraces from RecordNamesForKotlinTypeMapper
which are printed out when running some JVM IR tests (even though
they're ignored), e.g. localClassSimpleName.kt
Context for determine if a value parameter is captured from outer
context is not directly available after lowering, hence introduce a new
IrDeclarationOrigin for captured receiver parameter to avoid duplicate
calculation.
This change also makes sure that no line numbers are generated
in the wrappers in the JVM_IR backend.
Change-Id: If6c37f8a20894455abddb526039df059e02015a3
Unlike ordinary lambdas, suspend lambdas do the computation in
doResume(Ljava/lang/Object;Ljava/lang/Throwable;)Ljava/lang/Object;
method. As you can see, there are no decomposed parameters. As a result,
they used not to be generated.
To fix the issue, I add decomposed parameters to value parameters while
generating local variables table.
In addition, when generating suspend lambda for inline, the codegen
does not take this kind of parameters into account. This is also fixed.
#KT-18576: Fixed
If the range expression is not a local variable (which can be updated in
the loop body affecting loop behavior, see KT-21354), we can cache the
array length, thus turning a for-in-array loop into a simple optimizable
counter loop.
#KT-21321 In Progress
Ilmir Usmanov