Since this function is being called from the constraint solver now, we
need to generalize the way it obtains the Type of an Expression, as the
expression itself may not know its own type, only the solver does.
resolves rdar://134371893 / https://github.com/swiftlang/swift/issues/75999
Previously, the constraint solver would first attempt member lookup that
excluded members from transitively imported modules. If there were no viable
candidates, it would perform a second lookup that included the previously
excluded members, treating any candidates as unviable. This meant that if the
member reference did resolve to one of the unviable candidates the resulting
AST would be broken, which could cause unwanted knock-on diagnostics.
Now, members from transitively imported modules are always returned in the set
of viable candidates. However, scoring will always prioritize candidates from
directly imported modules over members from transitive imports. This solves the
ambiguities that `MemberImportVisibility` is designed to prevent. If the only
viable candidates are from transitively imported modules, though, then the
reference will be resolved successfully and diagnosed later in
`MiscDiagnostics.cpp`. The resulting AST will not contain any errors, which
ensures that necessary access levels can be computed correctly for the imports
suggested by `MemberImportVisibility` fix-its.
Resolves rdar://126637855.
`participatesInInference` is now always true for
a non-empty body, remove it along with the separate
type-checking logic such that empty bodies are
type-checked together with the context.
We used to detect partial applications based on member locators
and parent expressions, but using function reference kind +
check to see if self is applied is such simpler and hits both
uses of `isPartialApplication`.
Control enforcement of member import visibility requirements via a new option,
instead of piggy-backing on the existing IgnoreAccessControl option. Adopt the
option when doing fallback lookups for unviable members so that the compiler
can diagnose the reason that a member is inaccessible more reliably.
Previously, with MemberImportVisibility enabled decls with the package access
level could be mis-diagnosed as inaccessible due to their access level when
really they were inaccessible due to a missing import.
Resolves rdar://131501862.
