Generate TargetPlatformAttribute, and use TargetPlatformMinVersion for SupportedOSPlatformAttribute

[dsplaisted]

We should update how we are generating the assembly-level platform attributes:

• We should generate a TargetPlatformAttribute with a value of $(TargetPlatformIdentifier)$(TargetPlatformVersion)
• The SupportedOSPlatformAttribute should use the TargetPlatformMinVersion value, ie $(TargetPlatformIdentifier)$(TargetPlatformMinVersion)
  • Currently this goes through the SupportedOSPlatform property (which defaults to TargetPlatformVersion, which is incorrect). However, we should probably just remove this property, to avoid confusion with SupportedPlatform.

@wli3 @terrajobst

[wli3]

I renamed the property TargetPlatformVersion to SupportedOSPlatform while the attribute name is changed. I don't know Windows used TargetPlatformVersion for a while. Then the rename to SupportedOSPlatformAttribute is weird.

@mhutch is it ok to have the attribute mismatch the msbuild property?

@dsplaisted could you drive the discussion and the code change? The test infra and the code are mostly there. It should be trivial to tweak it once we get a conclusion.

[wli3]

The spec is very out of date and it does not mention TargetPlatformAttribute. @mhutch please update it

[dsplaisted]

Update: Use SupportedOSPlatformVersion property to flow into SupportedOSPlatformAttribute. Default value (on Windows) should be TargetPlatformMinVersion.