Re: [PATCH][gdb/testsuite] Generate .debug_aranges entry for dummy CU

[Tom de Vries via Gdb-patches <gdb-patches@sourceware.org>]

On 8/27/21 3:42 PM, Tom Tromey wrote:
>>>>>> "Tom" == Tom de Vries via Gdb-patches <gdb-patches@sourceware.org> writes:
> 
> Tom> A best practise for DWARF [1] is to generate .debug_aranges entries for CUs
> Tom> even if they have no address range.
> 
> Tom> Generate .debug_arange entries for the dummy CUs added by the DWARF assembler.
> 
> Tom> Tested on x86_64-linux.
> 
> Tom> [1] http://wiki.dwarfstd.org/index.php?title=Best_Practices
> 
> Tom> Any comments?
> 
> Tom> +	declare_labels dummy_cu
> 

[ FWIW, with the committed "[gdb/testsuite] Add label option to proc cu"
there's also no longer a need for declare_labels. ]

> If there are two dummy CUs, won't the labels clash?

No, due to the way cu labels are defined in "[gdb/testsuite] Add label
option to proc cu".

So, for say test-case gdb.dwarf2/dw2-ranges-base.exp we have these
references:
...
$ grep "Offset" outputs/gdb.dwarf2/dw2-ranges-base/dw2-ranges-base-dw.S
        .4byte        .Lcu0_begin       /* Offset into .debug_info */
        .4byte        .Lcu1_begin       /* Offset into .debug_info */
        .4byte        .Lcu2_begin       /* Offset into .debug_info */
...
where .Lcu0_begin is a dummy CU, .Lcu1_begin is the one specified by the
.exp file and .Lcu2_begin is another dummy CU.

Thanks,
- Tom