Fix Type.IsPublic for pointer and byref types

[buyaa-n]

Fixes #12355

Type.IsPublic returns false for pointer and byref types generated from a public type. Because RuntimeTypeHandle::GetAttributes returns 0 (NotPublic) for TypeDesc types (except generic type variables). Updated the code to return attributes from underlying element type (for pointer and byref types only)

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Issue Details

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Fixes #12355

Type.IsPublic returns false for pointer and byref types generated from a public type. Because RuntimeTypeHandle::GetAttributes returns 0 (NotPublic) for TypeDesc types (except generic type variables). Updated the code to return attributes from underlying element type (for pointer and byref types only)

Author:	buyaa-n
Assignees:	-
Labels:	area-System.Reflection
Milestone:	-

[lambdageek]

Mono changes LGTM

[steveharter]

LGTM; some minor test feedback

[steveharter]

@buyaa-n note some CI failures with the new tests

[jkotas]

Does System.Reflection.MetadataLoadContext need this fix as well?

[buyaa-n]

@buyaa-n note some CI failures with the new tests

Looking, thanks

Does System.Reflection.MetadataLoadContext need this fix as well?

Will check, thanks

[buyaa-n]

A question about the CI test failure: for Assert.True(typeof(delegate*<string, int>).IsPublic); the mono and CoreCLR behavior was different even before this change, CoreCLR somehow always return Public for this function pointer
mono always return not public for function pointer:

runtime/src/mono/mono/metadata/icall.c

Lines 1805 to 1806 in f1337d9

	if (m_type_is_byref (type) || type->type == MONO_TYPE_PTR || type->type == MONO_TYPE_FNPTR)
	return TYPE_ATTRIBUTE_NOT_PUBLIC;

I beleive we need same behavior for this, but i am not sure which value is expected, I guess it should be public, but want to confirm, please let me know what you think @steveharter @jkotas @GrabYourPitchforks @lambdageek

[buyaa-n]

Does System.Reflection.MetadataLoadContext need this fix as well?

MLC just returning TypeAttributes.AnsiClass, should we change it @steveharter?

runtime/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/Types/RoPointerType.cs

Line 28 in ced5e7a

protected sealed override TypeAttributes ComputeAttributeFlags() => TypeAttributes.AnsiClass;

runtime/src/libraries/System.Reflection.MetadataLoadContext/src/System/Reflection/TypeLoading/Types/RoByRefType.cs

Line 28 in ced5e7a

protected sealed override TypeAttributes ComputeAttributeFlags() => TypeAttributes.AnsiClass;

[jkotas]

MLC just returning TypeAttributes.AnsiClass

The value of TypeAttributes.AnsiClass is 0. It is better to think about it as returning default. It would be actually better to write it as returning default instead TypeAttributes.AnsiClass.

[buyaa-n]

The value of TypeAttributes.AnsiClass is 0. It is better to think about it as returning default. It would be actually better to write it as returning default instead TypeAttributes.AnsiClass.

Right 0, so it was same as what GetAttributes() method was returning, so i need to update MLC, thanks !

runtime/src/coreclr/vm/runtimehandles.cpp

Lines 809 to 815 in 4c2ea7e

	if (typeHandle.IsTypeDesc()) {
	if (typeHandle.IsGenericVariable()) {
	return tdPublic;
	}
	return 0;

[jkotas]

LGTM. Thank you!

[buyaa-n]

Thank you all the your review and suggestions! Build failure unrelated, merging