C#•13mo ago

❔ Roslyn analyzer test project can't compile `where T : unmanaged` type constraint

I've made a roslyn analyzer for some marshaling stuff. In my test project I try to analyze this source code:

    struct FooTest<T> where T : unmanaged
    {
        T good;
    }

    struct FooTest<T> where T : unmanaged
    {
        T good;
    }

but when I try to compile this code I get:

error CS0518: Predefined type 'System.Runtime.CompilerServices.IsUnmanagedAttribute' is not defined or imported

Why the error? I know there are similar issues with IsExternalInit, but my test project runs on .net 6.0 and the test code above is compiled with the latest C# version. AFAIK, the unmanaged constrain came with C# 7.3 / .net core 2.0.

16 Replies

swagrid•13mo ago

I've worked around it by injecting my own flag type into the compilation:

using System;
using Microsoft.CodeAnalysis;
using System.Runtime.CompilerServices;

namespace Microsoft.CodeAnalysis
{
    [CompilerGenerated]
    [Embedded]
    internal sealed class EmbeddedAttribute : Attribute
    {
    }
}

namespace System.Runtime.CompilerServices
{
    [CompilerGenerated]
    [Embedded]
    internal sealed class IsUnmanagedAttribute : Attribute
    {
    }
}

using System;
using Microsoft.CodeAnalysis;
using System.Runtime.CompilerServices;

namespace Microsoft.CodeAnalysis
{
    [CompilerGenerated]
    [Embedded]
    internal sealed class EmbeddedAttribute : Attribute
    {
    }
}

namespace System.Runtime.CompilerServices
{
    [CompilerGenerated]
    [Embedded]
    internal sealed class IsUnmanagedAttribute : Attribute
    {
    }
}

Thinker•13mo ago

Hold on, where exactly are you getting the error? In the analyzer project or in the test project?

swagrid•13mo ago

the test project or rather, during execution of the tests each test is building some source code that is then analyzed by the analyzer and when building that source code during test execution, that build fails

Thinker•13mo ago

Can you post the code for the tests? Sounds like you might not be adding the proper assembly references?

swagrid•13mo ago

That's what I'm suspecting as well, I had trouble with those in the past

swagrid•13mo ago

This file is used to generate the compilation

DiagnosticHelper.cs

swagrid•13mo ago

Should be largely copied from a sample project

333fred•13mo ago

Yeah, don't do that

swagrid•13mo ago

🙂

333fred•13mo ago

Use the testing framework For example, https://github.com/jmarolf/analyzer-start/blob/main/tests/TypesShouldBeUpperCaseTests.cs

swagrid•13mo ago

since when does the testing framework exist?

333fred•13mo ago

Quite a while

swagrid•13mo ago

Hmm, I've started using the analyzers basically when they were first introduced, and copy & pasted the testing for new analyzers from then probably shouldn't have done that

333fred•13mo ago

It's been around for 3 years at this point And in various incarnations before that

swagrid•13mo ago

🤷 maybe I've already missed it back then. Anyways thanks for the help This is sooo much better. Now I can delete this cursed helper.

Accord•13mo ago

Was this issue resolved? If so, run /close - otherwise I will mark this as stale and this post will be archived until there is new activity.

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❔ Roslyn analyzer test project can't compile `where T : unmanaged` type constraint