Facades and NotSupported assemblies are bloated with resources they don't use

[ericstj]

Often times we have builds that cross-compile and have very different implementations. Our resource conventions don't force folks to think about this, so the resources are often a superset of all configurations.

We should change the defaults so that this isn't the case.

I propose the following:

1. By default PartialFacades should not include any resources, unless a project opts-in. Folks should discover this relatively easily as SR.Foo will fail to work in the partial source. They can fix it by setting a flag and potentially providing specific resources for that build of the library.
2. By default NotSupported assemblies require a unique resx. We can change the path convention to something like Resources\NotSupported.resx instead of strings.resx

Across all our builds this will save over a MB of unused resources.

[joperezr]

Is this issue only to track those two cases? We also have the case where some resources are only used in a specific configuration but not in the rest. Of course fixing that issue would be harder than simply addressing the two cases you discussed above, but just wanted to know the scope of this issue.

[ericstj]

ATM this doesn't account for the per-configuration case since I imagine those have more nuanced requirements.

[danmoseley]

By default PartialFacades should not include any resources, unless a project opts-in. Folks should discover this relatively easily as SR.Foo will fail to work in the partial source. They can fix it by setting a flag and potentially providing specific resources for that build of the library.

Would this be done by setting to true (if not already explicitly set to false) if is true, then explicitly setting to false as needed to fix the build? Where would such a change go -- I could maybe do this if someone can give pointers.

[joperezr]

Fix for that is trivial, here is where we add the embedded resources to all projects when strings.resx exists:

runtime/eng/resources.targets

Lines 18 to 25 in 83d19de

	<ItemGroup Condition="'$(StringResourcesPath)' != '' and '$(OmitResources)' != 'true'">
	<EmbeddedResource Include="$(StringResourcesPath)">
	<Visible>true</Visible>
	<ManifestResourceName>$(StringResourcesName)</ManifestResourceName>
	<GenerateSource>true</GenerateSource>
	<ClassName>$(StringResourcesNamespace).$(StringResourcesClassName)</ClassName>
	</EmbeddedResource>
	</ItemGroup>

The way to fix what Eric suggests as point #1 above is to add a line in the property group before this line to say something like:

<OmitResources Condition=“'$(OmitResources)' == '' and '$(IsPartialFacadeAssembly)' == 'true'”>true</OmitResources>

[joperezr]

And of course after doing that for any partial facade that breaks the build would need to set OmitResources to false on the csproj for that tfm since it will mean that partial facade still requires the resources which is fine.