[PATCH][debug] Add -gforce-named-dies

[Tom de Vries]

On 08/22/2018 08:56 AM, Tom de Vries wrote:
> This is an undocumented developer-only option, because using this option may
> change behaviour of dwarf consumers, f.i., gdb shows the artificial variables:
> ...
> (gdb) info locals
> a = 0x7fffffffda90 "\005"
> D.4278 = <optimized out>
> ...

I just found in the dwarf 5 spec the attribute DW_AT_description
(present since version 3):
...
2.20 Entity Descriptions
Some debugging information entries may describe entities in the program
that are artificial, or which otherwise have a “name” that is not a
valid identifier in the programming language.

This attribute provides a means for the producer to indicate the purpose
or usage of the containing debugging infor

Generally, any debugging information entry that has, or may have, a
DW_AT_name attribute, may also have a DW_AT_description attribute whose
value is a null-terminated string providing a description of the entity.

It is expected that a debugger will display these descriptions as part
of displaying other properties of an entity.
...

AFAICT, gdb currently does not explicitly handle this attribute, which I
think means it's ignored.

It seems applicable to use DW_AT_description at least for the artificial
decls.

Perhaps even for all cases that are added by the patch?

I'll rewrite the patch.

Thanks,
- Tom