When a lambda captures a local variable without a contract, future
assignments can impact the smartcast stability for that variable within
the lambda. Because future assignments can appear in both resolved and
unresolved code, track each assignment as encountered. To determine if
a smartcast can be considered stable, check that all future assignments
are resolved and do not revert variable to a super type.
^KT-58191 Fixed
^KT-62547 Fixed
I also tested the commit by disabling DfaBooleanVariables in all tests
and checking what tests will fail
I didn't find anything that worked in K1, but doesn't work in K2 with
DfaBooleanVariables disabled
Related tests:
- DiagnosticCompilerTestFirTestdataTestGenerated$Resolve$Smartcasts
- LLFirPreresolvedReversedDiagnosticCompilerFirTestDataTestGenerated$Resolve$Smartcasts
- PreFirIdeSpecTestGenerated$NotLinked$Dfa
- DiagnosticCompilerTestFE10TestdataTestGenerated$Tests$SmartCasts
- FirPsiDiagnosticTestGenerated$Resolve$Expresssions.testSyntheticSmartCast
Handle case with FirField properly. Previously the code was returning
STABLE_VALUE in that case.
Note that in fact the changed 'when' branch expects only FirJavaField,
as FirFieldImpl should be handled by FirBackingFieldSymbol-check at
the beginning of the method. However, it is impossible to refer to
FirJavaField directly due to module visibility
Enumerate all cases more carefully via exhaustive 'when',
it's more readable and will prevent potential issues in future in case
more subclasses are added.
^KT-58279 Fixed
When applying function contracts to arguments, make sure the argument
variable hasn't been reassigned within a lambda. Contracts can only be
applied to unchanged variables, otherwise outdated type statements could
be added to the variable.
^KT-63151 Fixed
Postponed lambdas introduce a host of challenges in data-flow analysis.
While inheriting type statements was disabled while these challenges are
being considered, we must still copy type statements from non-postponed
lambda edges. It seems the same is true for implications.
Implications are copied from previous flows when there is only a single
previous flow. That is because it never seemed to be required based on
test results. However, a recent test case revealed that copying is
required when there are multiple previous flows, but only one flow is
from a non-postponed-lambda node.
Combining implications from multiple non-postponed-lambda nodes did not
have an impact on test results, so until such a test case can be
created, the overhead of calculating common implications from multiple
flows will be avoided.
^KT-63351 Fixed
This reverts commit bb6f466162.
Reverting the fix for KT-57417 as it causes failures in IntelliJ and
Space projects. May reintroduce fix after failures are investigated and
resolved.
When a property is implemented via class delegation, it should be
considered unstable for smart-casting. This is because it is unknown
what kind of stability the underlying class delegate property has. It
could be a stable property, or it could be implemented via a custom
getter and unstable.
^KT-57417 Fixed
It was decided to leave this code as is, because supporting
it would probably require introducing Implication-statements,
but this is not a good-enough use-case for such work.
When performing lookahead for local variable assignments, make sure
assignments taking place within loops are being propagated before loops.
This makes sure smartcasts within non-inline declarations before the
loop are disallowed.
^KT-63867 Fixed
There are many complications with the current design of passing data
from within in-place lambdas to surrounding code. Solving these
complications will involve more time to investigation than is available
within the K2 release. So we are disabling passing type statement
information from lambdas for the time being until more time can be
devoted to a more complete solution.
^KT-60958 Fixed
^KT-63530 Fixed
If the right-hand side of an equality comparison contains an assignment
to the variable used in the left-hand side, then implications about the
equality comparison within data-flow analysis cannot be applied, as the
value of the variable will be different after the comparison.
^KT-55096 Fixed
When the left-hand side of an equality comparison is known to be a
String, and the equality condition resolves to true, then the right-hand
side can be smart-cast to a String as well. This was working for String
expressions on the left-hand side but not for String constants.
^KT-57513 Fixed
When computing the conversion type for a type operator call, the
argument needs to be fully unwrapped before getting the resolved type.
This avoids the situation when the argument is a when-subject and the
assumed original type is not correct. Before, only smart-casts were
unwrapped, and this change will also unwrap when-subjects (as well as a
few other FirExpressions).
^KT-62114 Fixed
UncaughtExceptionPath edges are used to influence smart-casting within
catch and finally blocks. Previously these edges were added from every
node which could throw an exception. But only assignment nodes influence
smart-casts by resetting inference back to some less specific type.
Therefore, instead of tracking every possible node which could throw an
exception - even though almost every statement node can - only add edges
from assignment nodes to catch and finally blocks. This fixes many
missing exception cases and also reduces the total number of incoming
edges to catch and finally blocks.
#KT-56872 Fixed
In order to properly analyze top-level property initialization, a
control-flow graph must be created for FirFiles. This change adds the
foundation for the file CFG and updates body resolve to create the CFG.
Checking the CFG for proper initialization is separated into a following
change to ease code review.
KT-56683
Entering a `finally` block can happen from many different places:
through an exception, a jump, or normal exit from the `try` block. When
in the `finally` block, all DFA flows must be merged to have correct
smart casting. However, after the `finally` block, if exiting normally
or because of a jump, the combined flow from within the `finally` block
should not be used, but rather an alternate flow which combines the
correct flows from before the `finally` block.
```
try {
str as String // Potential cast exception
} finally {
str.length // Shouldn`t be resolved
}
str.length // Should be resolved
```
When building DFA flows, track the start of possible alternate flows,
and continue building them until they end. Both of these situations are
now marked on CFGNodes via interfaces.
When building the default DFA flow, and the source node is the end node
of alternate flows, attempt to use the alternate flow with the same edge
label instead of the default flow of the source node.
#KT-56888 Fixed
Jump edge targets are maintained globally within the CFG builder and are
added indiscriminately to `finally` exit nodes. This means that a
`finally` exit node could have a jump edge added which doesn't match how
the `finally` block was entered. Make sure edges are only added to the
exit node if they also exist on the enter node.
#KT-60723 Fixed
FIR expressions rendered by FirRenderer don't look very nice in error
messages anyway, and additionally, they can become arbitrarily large,
so we shouldn't use them in messages.
#KT-59449 Fixed
Previously, when a candidate was found with an applicability that is
better than the current best applicability, all previous candidates were
thrown away. Now we keep them, unless the new applicability is
successful. If no successful candidates are found, we fully resolve all
the unsuccessful ones and select the ones with the least bad
applicability. This improves diagnostics for unresolved calls.
#KT-57844 Fixed
The change is needed for the parallel resolution (^KT-55750), so we can resolve the declaration
under a lock that is specific to this declaration.
Previously, if LL FIR was resolving some FirClass, LL FIR resolved all its children too, and it had no control over what parts of the FIR tree were modified.
The same applied to the designation path, sometimes the classes on the designation path
might be unexpectedly (and without lock) modified.
This commit introduces LLFirResolveTarget, which specifies which exact declarations should be resolved during the lazy resolution of the declaration.
All elements outside the declarations specified for resolve in LLFirResolveTarget, should not be modified.
The logic of lazy transformers is the following:
- Go to target declaration collecting all scopes from the file and containing classes
- Resolve only declarations that are specified by the LLFirResolveTarget, performing the resolve under a separate lock for each declaration
^KT-56543
^KT-57619 Fixed
It's necessary because even for stable a.b.c.d we can't guarantee that
this reference will always point to the same symbol because
different capture type instantiations generate different scopes
with different resulting symbol instances.
This is mostly a revert of 2f61a2f56f
There, we erroneously assumed that we may take captured types as equal
if they are based on the same-typed projections.
Each instance of capturing defines its own captured type,
that should not be equal to any other type captured in other place.
Initial motivation was brought by FP Ultimate, where a piece of code
from the new test was found that started working differently after
recent changes.
The most obvious consequence is the change in addAllProjection.fir.kt:
one cannot use an instance as an argument when expected type
is captured type based on the same instance.
Otherwise, it would lead to CCE if we allowed to put arbitrary charsequences
to the list that initially was a MutableList<String>
All other test data changes (but addAllProjection.fir.kt and differentCapturedTypes.kt)
are irrelevant and will be fixed in the subsequent commits
Brian Norman