DWARF doesn't distinguish struct, tuple, and tuple struct

[tromey]

Currently the DWARF generated by rustc doesn't distinguish a struct, a tuple, or a tuple struct. They are all represented by DW_TAG_structure_type.

In gdb I handle this by examining the type name and assume that if it starts with "(" then it is a tuple. A tuple struct is detected by seeing if the first field is named "__0". Neither of these methods are really very good -- they work ok with today's debuginfo but are not really in the spirit of DWARF.

This requires a DWARF addition. In the short term it would be possible to pick an extension value in the DW_AT user space (this must be done carefully to avoid clashing with other known extensions).

[steveklabnik]

Triage: not sure if anything has changed here, but I don't think so.

[wesleywiser]

Visited during wg-debugging triage. We're not aware of any changes here or ongoing work to add this support in DWARF. For anyone interested, the first step is likely deciding how these kinds of types should be represented in DWARF (perhaps another attribute on the DW_TAG_structure_type entry?) and then working with the standard maintainers to incorporate it into the spec.