Make TypeComponentsCache trimmable #80726
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Contributes to dotnet#80165. The compiler is not able to get rid of the call to `PerNameQueryCache<M>.Factory` virtual method due to generic code sharing. Making this not shareable allows trimming it because now we can see `ConcurrentUnifier<StringKey, __Canon>.Factory` is never called (whereas `ConcurrentUnifier<__Canon, __Canon>.Factory` is called). This is a ~5 kB regression for apps that do use reflection. We could explore different strategies to make this trimmable and not be a size regression, but I'm not sure if it's really worth it. We'd like to get rid of this reflection stack implementation anyway and replace it with something more lightweight.
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Tagging subscribers to this area: @agocke, @MichalStrehovsky, @jkotas Issue DetailsContributes to #80165. The compiler is not able to get rid of the call to This is a ~5 kB regression for apps that do use reflection. We could explore different strategies to make this trimmable and not be a size regression, but I'm not sure if it's really worth it. We'd like to get rid of this reflection stack implementation anyway and replace it with something more lightweight. Cc @dotnet/ilc-contrib
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| // actually used in an app that is light on reflection use. But we do have other canonically equivalent | ||
| // ConcurrentUnifier instances in the program and their use could drag this implementation into the app. | ||
| // Making the ConcurrentUnifier instance unshareable gives the compiler the ability to unshare this. | ||
| private struct StringKey : IEquatable<StringKey> |
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Could this be a readonly record struct? Or is it not allowed in System.Private.CoreLib?
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We don't use records in CoreLib (or probably all of runtime repo in general). They add a lot more overhead than they're worth. Trading a couple lines of code for kilobytes of footprint for everyone who uses this is not a good tradeoff.
Recently: dotnet/aspnetcore#45604 (comment)
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My assumption was that this could be trimmed but I guess not. Time to read docs on trimming in more detail, thanks for the explanation.
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The problem is that a lot of the conveniences records bring is behind interfaces and virtual methods. E.g. ToString. It's hard to get rid of ToString.
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I'm marking this as no-review. As I was working on another piece of #80165 I came to realization that we'll probably need the components cache for nested types, but not the others, so this might require a different shape of the fix. |
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I've changed the way to do this and updated top-post with the description. This is ready for review. |
Follow up to dotnet#80726. Needed a bit more laziness to really get everything out of the picture.
Follow up to #80726. Needed a bit more laziness to really get everything out of the picture.
Contributes to dotnet#80165. Dispensing of reflection member infos is done through a member policies class. This is a generic class that has specialized implementations for each kind of member info. It used a clever trick to get to the specific implementations. Just access `MemberPolicies<EventInfo>.Default` to get one for events or `MemberPolicies<PropertyInfo>.Default` to get one for properties. It was also absolutely not trimming friendly. This change removes the clever trick and replaces it with good old fashioned parameter passing.
Follow up to dotnet#80726. Needed a bit more laziness to really get everything out of the picture.
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Contributes to #80165.
Dispensing of reflection member infos is done through a member policies class. This is a generic class that has specialized implementations for each kind of member info.
It used a clever trick to get to the specific implementations. Just access
MemberPolicies<EventInfo>.Defaultto get one for events orMemberPolicies<PropertyInfo>.Defaultto get one for properties. It was also absolutely not trimming friendly.This change removes the clever trick and replaces it with good old fashioned parameter passing.
Cc @dotnet/ilc-contrib