Generate Swift Testing code with Macros

[grynspan (Jonathan Grynspan)]

@adammcarter

As far as I can see the container should sit in the same scope as @Test, both inside of MySuite, but I'm assuming there's some implementation details here that means this doesn't work in my Macro

I believe this is a constraint, in some form, of how macros are expanded. @Douglas_Gregor are you able to provide any insight?

@adammcarter

having a glance at the Swift Testing library there's a __TestContainer enum generated which might not have the right access?

The __TestContainer-conforming enum is a side effect of how we currently emit test metadata into the binary. This type will go away in the future and be replaced by some in situ symbols, but we're not there yet.

Boring ABI plans/details here

• I discussed the current design and future plans a bit in this older forum post.
• We have documented our prospective "permanent" ABI here, which needs to be reviewed and approved by the testing workgroup once that's up and running. Note this design isn't finalized yet.
• Emission of data conforming to the "new" ABI is dependent on the @section attribute which is being pitched here.