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test allowing types in symchoices by giving them typedesc type #23966

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@metagn metagn commented Aug 16, 2024

Not sure what this solves/breaks but we might need it later, CI seems to pass

Araq pushed a commit that referenced this pull request Aug 25, 2024
…le types in symchoices (#23997)

fixes #23898, supersedes #23966 and #23990

Since #20631 ambiguous type symbols in templates are rejected outright,
now we generate a symchoice for type nodes if they're ambiguous, a
generalization of what was done in #22375. This is done for generics as
well. Symchoices also handle type symbols better now, ensuring their
type is a `typedesc` type; this probably isn't necessary for everything
to work but it makes the logic more robust.

Similar to #23989, we have to prepare for the fact that ambiguous type
symbols behave differently than normal type symbols and either error
normally or relegate to other routine symbols if the symbol is being
called. Generating a symchoice emulates this behavior, `semExpr` will
find the type symbol first, but since the symchoice has other symbols,
it will count as an ambiguous type symbol.

I know it seems spammy to carry around an ambiguity flag everywhere, but
in the future when we have something like #23104 we could just always
generate a symchoice, and the symchoice itself would carry the info of
whether the first symbol was ambiguous. But this could harm compiler
performance/memory use, it might be better to generate it only when we
have to, which in the case of type symbols is only when they're
ambiguous.
@metagn metagn closed this Aug 26, 2024
narimiran pushed a commit that referenced this pull request Sep 16, 2024
…le types in symchoices (#23997)

fixes #23898, supersedes #23966 and #23990

Since #20631 ambiguous type symbols in templates are rejected outright,
now we generate a symchoice for type nodes if they're ambiguous, a
generalization of what was done in #22375. This is done for generics as
well. Symchoices also handle type symbols better now, ensuring their
type is a `typedesc` type; this probably isn't necessary for everything
to work but it makes the logic more robust.

Similar to #23989, we have to prepare for the fact that ambiguous type
symbols behave differently than normal type symbols and either error
normally or relegate to other routine symbols if the symbol is being
called. Generating a symchoice emulates this behavior, `semExpr` will
find the type symbol first, but since the symchoice has other symbols,
it will count as an ambiguous type symbol.

I know it seems spammy to carry around an ambiguity flag everywhere, but
in the future when we have something like #23104 we could just always
generate a symchoice, and the symchoice itself would carry the info of
whether the first symbol was ambiguous. But this could harm compiler
performance/memory use, it might be better to generate it only when we
have to, which in the case of type symbols is only when they're
ambiguous.

(cherry picked from commit 09dcff7)
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