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Suppress linker warnings properly #84272

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merged 7 commits into from
Apr 4, 2023
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buyaa-n
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@buyaa-n buyaa-n commented Apr 3, 2023

The Linker warnings were incorrectly suppressed in #83554 and causing a build failure in dotnet/sdk#31571 (comment)

The method will be referenced for loading all .NET primitive types from user provided Core assembly. I assumed core primitive types are trimmer safe, but it seems unreferenced primitive type could be trimmed, therefore propagating the linker warning for the method. And suppressing the warning for the usages as I think it is safe to suppress these warnings for System.Object and System.Void types.

In order to unblock build failure caused by this raising this PR with the quick fix. Will reiterate the handling of other primitive types separately

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ghost commented Apr 3, 2023

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The Linker warnings were incorrectly suppressed in #83554 and causing a build failure in dotnet/sdk#31571 (comment)

The method will be referenced for loading all .NET primitive types from user provided Core assembly. I assumed core primitive types are trimmer safe, but it seems unreferenced primitive type could be trimmed, therefore propagating the linker warning for the method. And suppressing the warning for the usages as I think it is safe to suppress these warnings for System.Object and System.Void types.

In order to unblock build failure caused by this raising this PR with the quick fix. Will reiterate the handling of other primitive types separately

Author: buyaa-n
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area-System.Reflection.Emit

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@jkotas
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jkotas commented Apr 3, 2023

causing a build failure in dotnet/sdk#31571 (comment)

What is the build configuration where this is causing a build failure? I would expect that the new Reflection.Emit implementation is always going to be trimmed for now, and thus it should not produce any warnings. The warning can be a symptom of some more fundamental problem.


default: throw new NotSupportedException(SR.Format(SR.NotSupported_Signature, type.FullName));
// We need to translate from Reflection.Type to SignatureTypeEncoder.
if (id > -1)
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Why the extra if?

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module.GetTypeIdFromCoreTypes(type) returns -1 in case it is not core type or the type not found

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Right but why do you optimizing for exception code path?

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@buyaa-n buyaa-n Apr 4, 2023

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For now we only support core types, eventually that path will be updated to support other types

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Yep but even in that case they would better be handled via default: than this if

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What would a default signature option do?

The existing PrimitiveTypeCode defined by System.Reflection.Metadata looks very similar for the CoreTypeId. Maybe we should just use PrimitiveTypeCode.

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we should just use PrimitiveTypeCode.

Thoughts about this one?

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@buyaa-n buyaa-n Apr 4, 2023

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Thoughts about this one?

Tried, PrimitiveTypeCode uses SignatureTypeCode values that are not matching by the index, specifically the value of IntPtr is 24, UIntPtr is 25, Object value is 28, leaving a gap in the array indexes

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I checked why the warnings were not caught by the runtime build originally.
The reason is that there's a difference in what the runtime does and SDK.
Runtime runs the linker on all framework assemblies in the "library" mode - so it trims things down to only code accessible through public APIs of each assembly.
But SDK runs the linker on all framework in the "copy" mode - so all code is kept.

In this case, the offending code is not connected to any public API (yet I assume), so in the "library" mode it gets trimmed away. But SDK will still see it.

@sbomer for ideas - the SDK is effectively testing "more" than runtime.

I create #84297 to track the "infra" issue.

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Hope the suggested edits make sense

@buyaa-n
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buyaa-n commented Apr 4, 2023

Hope the suggested edits make sense

Yes, it makes sense, thank you!

@buyaa-n
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buyaa-n commented Apr 4, 2023

The failure unrelated and known, merging

@buyaa-n buyaa-n merged commit 3e6ad47 into dotnet:main Apr 4, 2023
@buyaa-n buyaa-n deleted the suppress-warning branch April 4, 2023 23:22
@ghost ghost locked as resolved and limited conversation to collaborators May 5, 2023
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5 participants