Work out how to deal with ComVisible and if it can be moved to csproj

[mungojam]

It would be good if this could be cleared out or moved to the csproj. Below is a very typical example based on the default project created by Visual Studio. I think without ComVisible(false), the default in the compiler is true.

// Setting ComVisible to false makes the types in this assembly not visible
// to COM components.  If you need to access a type in this assembly from
// COM, set the ComVisible attribute to true on that type.
[assembly: ComVisible(false)]

// The following GUID is for the ID of the typelib if this project is exposed to COM
[assembly: Guid("29644e8e-6ee0-4337-8658-c926dfa83f55")]

[andrew-boyarshin]

Yeah, ComVisible is still true by default in CPS I'm afraid. It's a known bad practice and even VS sets it to false by default in AssemblyInfo on project generation. I believe we must preserve default behavior (true), but make a diagnostic for that case.

[leotsarev]

At least

[assembly: Guid("29644e8e-6ee0-4337-8658-c926dfa83f55")]

could be dropped?

[HavenDV]

A related issue: https://github.com/Microsoft/msbuild/issues/2281

Perhaps after some time the following code will become available:

<ItemGroup>
  <AssemblyAttribute Include="System.Runtime.InteropServices.ComVisibleAttribute">
    <_Parameter1>false</_Parameter1>
    <_Treat_Parameter1AsLiteral>true</_Treat_Parameter1AsLiteral>
  </AssemblyAttribute>
</ItemGroup>

[commonsensesoftware]

@HavenDV ... I hope so. I'm still championing my proposed more succinct flavor of:

<ItemGroup>
  <AssemblyAttribute
    Include="System.Runtime.InteropServices.ComVisibleAttribute"
    IsLiteral="true"
    _Parameter1="false" />
</ItemGroup>

.. but I'll take a win however I can get it