WIP [dwarf] Emit all imported modules and declarations in debug

[ibuclaw]

Complimentary PR for #4746

Needs suggestions from those who have a better understanding of DMD's backend. @yebblies @WalterBright ?

I'm looking for an ideal way to generate a symbol of some kind for an Import declaration for dwarf.c to handle, need at least following the information:

• Real module name (ie: foo.bar)
• The alias given to the module, if such exists (ie: baz)
• Whether or not it is an output module (eg: set extern for modules not being emitted)

I guess this should be in a Symbol so the same routine can handle both module imports and declaration imports.

Requirements for declaration imports:

• Real declaration name
• The alias given to the declaration, if such exists

However, it would be a nice-to-have to also handle type imports too (structs, classes, enums). For this a stub type declaration of sorts could be used.

[ibuclaw]

@WalterBright - ping. I would like to know the best way to represent an Import as a Symbol with the information I've requested for.

Thanks

[ibuclaw]

It seems like it was a mistake to remove ModuleInfoDeclaration two years ago, as now I need mod->toSymbol() to generate a real Module symbol, not a ModuleInfo symbol.

[ibuclaw]

Still can't make use of the scope and imports lookup feature of gdb using programs built by dmd. I don't really have the willpower to make you fix this.

[WalterBright]

I wish you wouldn't delete things like this.

[ibuclaw]

Why, patch is still available for anyone who wants to give it a try. https://patch-diff.githubusercontent.com/raw/dlang/dmd/pull/4750.diff

If you would like a rundown on what the structure should look like in dwarf, I'm always here to help.