Namespace Functions not supported as EntryPoint

[taxmancw]

struct PSInput
{
    float4 color : COLOR;
};

namespace Pixel
{
    float4 Main(PSInput input) : SV_TARGET
    {
        return input.color;
    }    
}

In the following example, specifying Pixel::Main as the entry point fails to compile in Slang, but will work in HLSL compilers FXC and DXC.

[tangent-vector]

Thanks. This is definitely worth fixing.

Note for whatever contributor picks this up: our intention is to also support entry point functions as members of struct types, so we should try to ensure that when we write the code to handle the namespace case in this issue we also write code that is looking toward that option down the road.

[tangent-vector]

I am putting together a test case for this feature, but I cannot seem to get dxc (when driven via the dxcompiler.dll API) to recognize an entry point like the above. For a trivial compute shader, I get as output:

error: missing entry point definition

Can somebody confirm the expected versions of dxc for which entry points in namespaces work?

[taxmancw]

It appears that DXC is actually also lacking support for it and has yet to be addressed. https://github.com/Microsoft/DirectXShaderCompiler/issues/1854

[natduca]

Q3 language hardening