Systematically recompute denotations when needed in rechecker phases #24302
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Fixes scala#23582 But it is quite a hack. We should try to find a more principled solution.
To recompute a denotation of a NamedType in a new phase we have a subtle logic that sometimes recomputes the denotation from the prefix and the symbol or name, and at other times recomputes it by transforming the previous denotation with `current`. This logic was wrong for capturing types. We sometimes recomputed by transforming the previous denotation where this led to wrong denotation. We "fixed" problems this caused before by sometimes doing an explicit `recomputeDenot`. But that's unsatisfactory since we can never know whether we do that in all cases where it's needed. This commit is a more principled fix where fix the logic that determines how to recompute a NamedType's denotation by consulting sometimes the rechecker's advice. recomputed by transforming the previous denotation where this led
collectCapturedMutVars was moved to Setup since it needs to run at Setup phase in order not to force NamedType denotations prematurely. But then we don't need a second tree traversal, we can integrate it with the main Setup traversal instead.
odersky
changed the title
bracevac
approved these changes
Nov 4, 2025
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Fixes #23582
The first commit was a quick hack.
The second commit implements a more principled solution.