getproperty(::Type,f::Symbol): type assert when f === :parameters
#57630
Conversation
It is common to access the `parameters` field of a `DataType` using `getproperties`. However, when the first argument is not inferred as `DataType`, the return type infers as `Any`, instead of as `Core.SimpleVector`. I believe this causes much type instability and invalidation. The proper fix would probably be to introduce a getter function, something like `_get_datatype_parameters(x::DataType) = x.parameters`, then use the getter instead of directly using `getproperties`. For `Compiler`, we may have to introduce a getter anyway, as `Compiler.getproperty === Core.getfield`, but outside of the compiler this seems like a good enough hacky fix.
nsajko
added
types and dispatch
This is meant to be a follow up PR. |
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Can we instead improve the precision of the compiler model? I don't really like adding these kinds of special cases |
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Out of curiosity, are you saying the compiler should exploit the fact that the subtypes of |
The PR only gets rid of 1% of the invalidations that happen when my package is loaded, so I misjudged. |
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I think I'll rather add |
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If inference didn't work, it seems probably likely the program is relying on implementation details that may not be stable. Typically applications should not access parameters field or rely on it (unless they are doing something to implement those type system details themselves) |
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The |
It is common to access the
parametersfield of aDataTypeusinggetproperties. However, when the first argument is not inferred asDataType, the return type infers asAny, instead of asCore.SimpleVector. I believe this causes much type instability and invalidation.The proper fix would probably be to introduce a getter function, something like
_get_datatype_parameters(x::DataType) = x.parameters, then use the getter instead of directly usinggetproperties. ForCompiler, we may have to introduce a getter anyway, asCompiler.getproperty === Core.getfield, but outside of the compiler this seems like a good enough hacky fix.