On 19-05-2020 22:32, Tom Tromey wrote:
>>>>>> "Tom" == Tom de Vries <tdevries@suse.de> writes:
> 
> Tom> Fix the inconsistency by completing implementation of
> Tom> dw2_map_matching_symbols.
> 
> Thanks for doing this.
> 
> Tom> Tested on x86_64-linux, both with native and target board
> Tom> cc-with-debug-index.
> 
> Tom> Any comments?
> 
> This may be the only barrier to supporting Ada in .gdb_index.
> So, it seems like the Ada check in dwarf2/index-write.c should probably
> be removed as well...?
> 
> I'm not 100% sure whether it will work or not.

Using this patch, I managed to get it working.

The patch does the following:
- enable ada .gdb_index by removing the ada check in write_psymbols
- copy some ada-specific code from debug_names::insert to
  write_psymbols
- disable a workaround for gold/15646 in dw2_expand_marked_cus

As for the disabled workaround, I ran into trouble in
gdb.ada/access_tagged_param.exp, where setting a breakpoint on foo failed.

The index shows that there are two entries for foo, one variable, one
function:
...
[3733] foo:
        3 [global, variable]
        5 [global, function]
...
The workaround skips the function, so disabling the workaround allows
the test to pass (my guess atm is that the workaround is not precise
enough).

FWIW, if I use .debug_names instead, I see the same pattern:
...
[445] #0b887389 foo:
        <6> DW_TAG_subprogram DW_IDX_compile_unit=5 DW_IDX_GNU_external=1
        <2> DW_TAG_variable DW_IDX_compile_unit=3 DW_IDX_GNU_external=1
...

Thanks,
- Tom