They are mostly necessary for argument mapping during resolution.
To support a couple checkers, we transform named args for varargs
into "fake" spread expressions.
Other than that, named arguments aren't needed for anything and often
lead to bugs where we forget to unwrap them for something, so it's
better to get rid of them.
#KT-66124
This fixes some cases where we infer some type variable inside one
of the branches to Nothing instead of the expected type because Nothing
appeared in some other branch.
Specifically, we add an equality instead of a subtype constraint during
completion of calls to synthetic functions for if/when, try and !!.
We don't do it when the call contains a (possibly nested) elvis or is
inside the RHS of an assignment.
Otherwise, we would prevent some smart-casts.
#KT-65882 Fixed
The primary constructor of a class needs to be the first subgraph of the
class control-flow graph. Based on the Kotlin specification, class
initialization order goes first primary constructor, in-place
declarations (properties and init blocks), and then secondary
constructors. If the class doesn't have a primary constructor, then it
is just skipped in the order.
Unfortunately, the class control-flow graph had in-place declarations
first and then all constructors. Instead, we should treat the primary
constructor as the first in-place declaration, and then continue with
the existing processing as secondary constructors. This will guarantee
that super constructor calls have the correct property initialization
information.
^KT-65093 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
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
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
Interpretation: a graph A is a subgraph of B if information available at
nodes of A depends on the paths taken in B. For example, local classes
are subgraphs of a graph in which they are declared, and members of
those classes are subgraphs of the local class itself - because these
members can reference captured values.
Consequences:
* if graph G is a subgraph of node N, then G is a subgraph of N's
owner;
* `ControlFlowAnalysisDiagnosticComponent` will only visit root graphs;
* `graph.traverse` will ignore subgraph boundaries, as if all subgraphs
are inlined into one huge root graph;
* if a control flow checker needs information from a declaration to
which a graph is attached, it must look at subgraphs explicitly.
For example, consider the `callsInPlace` checker. When a function
has a `callsInPlace` contract and a local declaration, the checker must
visit that local declaration to ensure it does not capture the allegedly
called-in-place argument - hence `graph.traverse` will look at the
nodes. However, the local declaration can also be a function with its
own `callsInPlace` contracts, so the checker should also run for it in
isolation. If that sounds quadratic, that's because unfortunately it is.
Quick quiz:
Q: In a CFG, what does `a -> b -> c -> d` mean?
A: `a`, then `b`, then `c`, then `d`.
Q: In a CFG, what does `a -> b -> d; a -> c -> d` mean?
A: `a`, then `b` or `c`, then `d`.
Q: So how do you encode "a, then (b, then c) or (c, then b), then d`?
A: You can't.
Problem is, you need to, because that's what `a; run2({ b }, { c }); d`
does when `run2` has a contract that it calls both its lambda arguments
in-place: `shuffle(listOf(block1, block2)).forEach { it() }` is a
perfectly valid implementation for it, as little sense as that makes.
So that's what union nodes solve. When a node implements
`UnionNodeMarker`, its inputs are interpreted as "all visited in some
order" instead of the normal "one of the inputs is visited".
Currently this is used for data flow. It *should* also be used for
control flow, but it isn't. But it should be. But that's not so easy.
BTW, `try` exit is NOT a union node; although lambdas in one branch can
be completed according to types' of lambdas in another, data does not
flow between the branches anyway (since we don't know how much of the
`try` executed before jumping into `catch`, and `catch`es are mutually
exclusive) so a `try` expression is more like `when` than a function
call with called-in-place-exactly-once arguments. The fact that
`exitTryExpression` used `processUnionOfArguments` in a weird way
should've hinted at that, but now we know for certain.
In this commit we upgrade FIR builder inference logic from
the compiler version to 1.7. FIR-based compiler now works with
"don't use builder inference" flag always ON and supports switching
the flag "use builder inference only if needed". To do it,
ContraintSystemCompleter (FIR) and KotlinConstraintSystemCompleter (FE 1.0)
are made similar with extracting some common parts into
ConstraintSystemCompletionContext.
Test status: one BB test fails after this commit (KT-49285).
Also we have a crush in DFA logic in FIR bootstrap test and somehow
questionable behavior in FIR diagnostic test. However,
two BB tests were fixed, the 3rd case from KT-49925 were also fixed.
#KT-49925 Fixed
In this commit we add nullability to upper type of a substituted
constraint in the situation like (Stub<_L> <: SomeType),
where _L is fixed to nullable Stub<_L>?.
We have to change this constraint to L <: SomeType? and not to
L <: SomeType as before, otherwise nullability become broken
(direct substitution of Stub<_L> to L is illegal here).
#KT-50470 Fixed
Some existing tests start failing after previous commits adding @Exact
attribute to `?:`
They have a form:
var x: String? = nullable()
if (x == null) {
x = nullable() ?: "" // considering @Exact the whole elvis is inferred to nullable from expect type
}
x.length // should be smart cast
- Add utilities to add new attribute to ConeAttributes
- Get rid of FlexibleNullability attribute (it can be easily inferred
for any flexible type at any moment)
- Fix determining of EnhancedNullability attribute
Update includes:
- Changing syntax of `OI/`NI` tags from `<!NI;TAG!>` to `<!TAG{NI}!>`
- Fix some incorrect directives
- Change order of diagnostics in some places
- Remove ignored diagnostics from FIR test data (previously `DIAGNOSTICS` didn't work)
- Update FIR dumps in some places and add `FIR_IDENTICAL` if needed
- Replace all JAVAC_SKIP with SKIP_JAVAC directive
Kirill Rakhman