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a93c5d79b9
fixes #16700, fixes #20916, refs #24010 Fixes the instantiation issues for proc param default values encountered in #24010 by: 1. semchecking generic default param values with `inGenericContext` for #22029 and followups to apply (the bigger change in semtypes), 2. rejecting explicit generic instantiations with unresolved generic types inside `inGenericContext` (sigmatch change), 3. instantiating the default param values using `prepareNode` rather than an insufficient manual method (the bigger change in seminst). This had an important side effect of references to other parameters not working since they would be resolved as a symbol belonging to the uninstantiated original generic proc rather than the later instantiated proc. There is a more radical way to fix this which is generating ident nodes with `tyFromExpr` in specifically this context, but instead we just count them as belonging to the same proc in `hoistParamsUsedInDefault`. Other minor bugfixes: * To make the error message in t20883 make sense, we now give a "cannot instantiate" error when trying to instantiate a proc generic param with `tyFromExpr`. * Object constructors as default param values generated default values of private fields going through `evalConstExpr` more than once, but the VM doesn't mark the object fields as `nfSkipFieldChecking` which gives a "cannot access field" error. So the VM now marks object fields it generates as `nfSkipFieldChecking`. Not sure if this affects VM performance, don't see why it would. * The nkRecWhen changes in #24042 didn't cover the case where all conditions are constantly false correctly, this is fixed with a minor change. This isn't needed for this PR now but I encountered it after forgetting to `dec c.inGenericContext`.
14 lines
227 B
Nim
14 lines
227 B
Nim
discard """
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action: reject
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nimout: '''
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t20883.nim(13, 4) template/generic instantiation of `foo` from here
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t20883.nim(9, 11) Error: cannot instantiate: 'U'
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'''
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"""
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proc foo*[U](x: U = U(1e-6)) =
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echo x
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foo[float]()
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foo()
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