/azp run

After talking with @terrajobst , having the notion of a PrimaryAssembly is fine but we should not be explicit about what PrimaryAssembly we want. Instead, it should decide what the PrimaryAssembly is based on the given references and there are rules about it, which are described here for C#: http://sourceroslyn.io/#Microsoft.CodeAnalysis/ReferenceManager/CommonReferenceManager.Binding.cs,536628815dfdb8a2

IMHO, we should not expose PrimaryAssembly. Instead, we should be thinking about trying to remove PrimaryAssembly altogether and getting the compiler to be framework agnostic.

That's fair, however the scope of this PR is to bring the ast compiler on par with the cli arguments, as they currently stand.

Rebased on top of latest changes

Following conversations with @TIHan, I've changed the api surface so that PrimaryAssembly is no longer exposed. Until #8043 is merged, it will determine that value based on the current runtime.

@eiriktsarpalis is this work dependent on #8043?

@cartermp not exactly, but we decided it would be less work if we let #8043 merge first.

Makes sense.

Are you planning on merging #8043 for 5.0? If not I think I should just go ahead and merge this, since it fixes a broken component of the compiler.

I think that's @TIHan's call, but conservatively I'm going to estimate that it won't get in for F# 5.

I've rebased on top of latest master.

After talking with @terrajobst , having the notion of a PrimaryAssembly is fine but we should not be explicit about what PrimaryAssembly we want. Instead, it should decide what the PrimaryAssembly is based on the given references and there are rules about it, which are described here for C#: http://sourceroslyn.io/#Microsoft.CodeAnalysis/ReferenceManager/CommonReferenceManager.Binding.cs,536628815dfdb8a2

To expand on this: you should chat with @jaredpar and how Roslyn solved this. AFAIK the core assembly is determined by picking the assembly that in turn has no references. If checking that is expensive, you could try a fast pass by checking for mscorlib and System.Runtime first and see whether they have references and if they do, probe all references.

AFAIK the core assembly is determined by picking the assembly that in turn has no references.

The core assembly has no references and contains System.Object. There are completely valid cases where assemblies have no references but are not in fact the core assembly.

If checking that is expensive, you could try a fast pass by checking for mscorlib and System.Runtime first and see whether they have references and if they do, probe all references

FWIW: This check hasn't ever come up as a perf issue for us

Thanks for this @eiriktsarpalis