Re: [PATCH 1/5] Remove call to dwarf2_per_objfile::adjust from ranges readers

[Andrew Burgess <aburgess@redhat.com>]

Andrew Burgess <aburgess@redhat.com> writes:

> Hi Tom,
>
> So, I don't know the details of the DWARF reader too well, so my attempt
> to review this patch might be just wasting your time.  But I didn't
> really understand what was going on here, so...
>
> Tom Tromey <tom@tromey.com> writes:
>
>> dwarf2_per_objfile::adjust applies gdbarch_adjust_dwarf2_addr to an
>> address, leaving the result unrelocated.  However, this adjustment is
>> only needed for text-section symbols -- it isn't needed for any sort
>
> I didn't know if the use of the word 'symbols' here was significant.
> gdbarch_adjust_dwarf2_addr operates on addresses, and I guess symbol
> could be a synonym for address in some contexts.  But the addresses here
> do seem to be .text addresses, so clearly there's some important
> distinction that I'm not understanding.
>
>> of address mapping.  Therefore, these calls can be removed from
>
> gdbarch_adjust_dwarf2_addr seems to be relevant for .text addresses,
> which is what you're handling here, but you are creating a map, but it's
> not clear _why_ those addresses wouldn't need to be updated.

A follow on question.  Looking through gdb/dwarf/ there seem to be
several other places where the addrmap_mutable::set_empty is called, and
in at least some of those places the addresses are still being
adjusted.  E.g.:

  dwarf2_ranges_read
  cooked_indexer::check_bounds
  cooked_indexer::scan_attributes

Why do these not need changing?

Thanks,
Andrew



>
> Sorry to ask what are probably obvious questions...
>
> Thanks,
> Andrew
>
>> read_addrmap_from_aranges and create_addrmap_from_gdb_index.
>> ---
>>  gdb/dwarf2/aranges.c        | 2 --
>>  gdb/dwarf2/read-gdb-index.c | 2 --
>>  2 files changed, 4 deletions(-)
>>
>> diff --git a/gdb/dwarf2/aranges.c b/gdb/dwarf2/aranges.c
>> index d577db62726..0d1dc11e27a 100644
>> --- a/gdb/dwarf2/aranges.c
>> +++ b/gdb/dwarf2/aranges.c
>> @@ -190,8 +190,6 @@ read_addrmap_from_aranges (dwarf2_per_objfile *per_objfile,
>>  	      continue;
>>  	    }
>>  	  ULONGEST end = start + length;
>> -	  start = (ULONGEST) per_objfile->adjust ((unrelocated_addr) start);
>> -	  end = (ULONGEST) per_objfile->adjust ((unrelocated_addr) end);
>>  	  mutable_map->set_empty (start, end - 1, per_cu);
>>  	}
>>  
>> diff --git a/gdb/dwarf2/read-gdb-index.c b/gdb/dwarf2/read-gdb-index.c
>> index 8c0895b9639..cc6361674e8 100644
>> --- a/gdb/dwarf2/read-gdb-index.c
>> +++ b/gdb/dwarf2/read-gdb-index.c
>> @@ -566,8 +566,6 @@ create_addrmap_from_gdb_index (dwarf2_per_objfile *per_objfile,
>>  	  continue;
>>  	}
>>  
>> -      lo = (ULONGEST) per_objfile->adjust ((unrelocated_addr) lo);
>> -      hi = (ULONGEST) per_objfile->adjust ((unrelocated_addr) hi);
>>        mutable_map.set_empty (lo, hi - 1, per_bfd->get_cu (cu_index));
>>      }
>>  
>>
>> -- 
>> 2.43.0