Hi,

These weeks I finished implementing a template _d_newitemU. It creates an uninitialised struct object. It's used to lower expressions such as new S(args), where S is a struct.

The compiler introduces the required memset(p, 0, T.sizeof) (for what was previously _d_newitemT) or memcpy(p, T.init, T.sizeof) (for what was previously _d_newitemiT) itself. This helps reduce the number of templates defined in DRuntime in the attempt to "unify" some instantiations of _d_newitemU.

I am now working to get the final tests for new S(...) working, where S is a non-nested struct. I haven't touched on nested structs yet as they require copying vthis and vthis2, which is cumbersome to do in expressionsem.d. Currently, these fields are set in e2ir.d, where there is existing machinery for duplicating them. I am now trying to "port" this code to expressionsem.d, but I'm struggling with this because there is no 1:1 mapping between the backend and frontend constructions.

Regarding _d_arraycatnTX, I feel the work is nearly done. What's preventing buildkite to pass is that most likely there are cases in dmd where .ptr is used on strings that result from concatenations. These strings don't have a \0 character at the end, hence the seg fault. I can't reproduce the issue on my machine, so I'm kind of left in the dark here.

Do you have any suggestions about how to find the cause of this failure?

Thanks,
Teodor