Support or ignore attributes on type parameters

[jskeet]

C# 8 uses attributes on type parameters for nullability, and this causes problems for the tool at the moment.

Example:

Foo.csproj:

<Project Sdk="Microsoft.NET.Sdk">
  <PropertyGroup>
    <TargetFramework>netstandard2.0</TargetFramework>
    <LangVersion>preview</LangVersion>
    <NullableContextOptions>enable</NullableContextOptions>
  </PropertyGroup>
</Project>

Class1.cs:

namespace Foo
{
    public class Class1<T> where T : class
    {
    }
}

Invocation:

$ generate-public-api --project-path Foo.csproj --target-frameworks netcoreapp3.0 --assembly Foo.dll

Error:

Failed: System.Exception: dotnet exit code -532462766. Directory: C:\Users\skeet\AppData\Local\Temp\evz1pbfi.oin. Args: run --configuration Release --framework netcoreapp3.0 -- C:\Users\skeet\AppData\Local\Temp\evz1pbfi.oin\bin\Release\netcoreapp3.0\Foo.dll C:\Users\skeet\AppData\Local\Temp\evz1pbfi.oin\bin\Release\netcoreapp3.0\Foo.netcoreapp3.0.received.txt c:\Users\jon\Test\Foo. Output: . Error:
Unhandled Exception: System.NotImplementedException: Attributes on type parameters is not supported. And weird
   at PublicApiGenerator.ApiGenerator.PopulateGenericParameters(IGenericParameterProvider publicType, CodeTypeParameterCollection parameters)
   at PublicApiGenerator.ApiGenerator.CreateTypeDeclaration(TypeDefinition publicType, String[] whitelistedNamespacePrefixes, HashSet`1 excludeAttributes)
   at PublicApiGenerator.ApiGenerator.CreatePublicApiForAssembly(AssemblyDefinition assembly, Func`2 shouldIncludeType, Boolean shouldIncludeAssemblyAttributes, String[] whitelistedNamespacePrefixes, HashSet`1 excludeAttributes)
   at PublicApiGenerator.ApiGenerator.GeneratePublicApi(Assembly assembly, Type[] includeTypes, Boolean shouldIncludeAssemblyAttributes, String[] whitelistedNamespacePrefixes, String[] excludeAttributes)
   at Program.Main(String[] args) in C:\Users\skeet\AppData\Local\Temp\evz1pbfi.oin\Program.cs:line 14

   at PublicApiGenerator.Tool.Program.RunDotnet(String workingArea, Boolean verbose, String arguments) in C:\projects\apiapprover\src\PublicApiGenerator.Tool\Program.cs:line 136
   at PublicApiGenerator.Tool.Program.GeneratePublicApi(String assembly, String package, String workingArea, String framework, String outputDirectory, Boolean verbose) in C:\projects\apiapprover\src\PublicApiGenerator.Tool\Program.cs:line 93
   at PublicApiGenerator.Tool.Program.Main(String targetFrameworks, String assembly, String projectPath, String package, String packageVersion, String generatorVersion, String workingDirectory, String outputDirectory, Boolean verbose, Boolean leaveArtifacts) in C:\projects\apiapprover\src\PublicApiGenerator.Tool\Program.cs:line 56

[danielmarbach]

You are such a troublemaker 😉🤣 I hope I can give this a look before my long vacation break

[jskeet]

No hurry!

[danielmarbach]

Looks like Mono.Cecil is working on this

jbevain/cecil#594

related to

dotnet/roslyn#29997

[danielmarbach]

Ok I have a workaround that I can push soon and I also found a way of at least presenting, for now, the nullable attributes. After that, we can start looking into pretty printing those attributes

[danielmarbach]

This enables for now support of Type attributes

#65

I can release this as a minor soon

[danielmarbach]

Done. Should be available on nuget soonish

[jskeet]

Thanks, you're a star :)