Re: [PATCH][gdb/symtab] Handle DW_AT_ranges with DW_FORM_sec_off in partial DIE

[Tom de Vries <tdevries@suse.de>]

On 1/25/21 4:27 PM, Simon Marchi wrote:
> 
> 
> On 2021-01-25 7:52 a.m., Bernd Edlinger wrote:
>> On 1/25/21 1:24 PM, Tom de Vries wrote:
>>> Hi,
>>>
>>> While looking into a failure in gdb.go/package.exp with gcc-11, I noticed that
>>> gdb shows some complaints when loading the executable (also with gcc-10, where
>>> the test-case passes):
>>> ...
>>> $ gdb -batch -iex "set complaints 100" package.10 -ex start
>>> During symbol reading: Attribute value is not a constant (DW_FORM_sec_offset)
>>> Temporary breakpoint 1 at 0x402ae6: file gdb.go/package1.go, line 8.
>>> During symbol reading: Attribute value is not a constant (DW_FORM_sec_offset)
>>> During symbol reading: Invalid .debug_rnglists data (no base address)
>>> ...
>>>
>>> Fix this by using as_unsigned () to read DW_AT_ranges in the partial DIE
>>> reader, similar to how that is done in dwarf2_get_pc_bounds.
>>>
>>> Tested on x86_64-linux.
>>>
>>> Any comments?
>>>
>>
>> Oh, interesting.
>>
>> This is exactly what I have posted here:
>>
>> https://sourceware.org/pipermail/gdb-patches/2021-January/174660.html
>>
>> but my test case shows the regression in the partial symbols.
>>
>>
>>
>> Maybe you can take my test case and merge it to your patch?
>>
>>

I've looked at it, but it's optimized code, which may be fragile in
terms of number of break locations.  I wouldn't mind a dwarf assembly
version of that one though.

>> Thanks
>> Bernd.
>>
> 
> Haha, I also wrote the same patch:
> 
> https://sourceware.org/pipermail/gdb-patches/2021-January/175225.html
> 

Heh, this starts to sound a lot like a "how many software engineers does
it take to fix one line of code" kind of joke :)

> Either of your patches is fine with me.  Note that the test that I add
> later in my series (written with the DWARF assembler) triggers the bug
> as well.

Ah, that's good to know.

I've push mine, and added you both as author in the ChangeLog.

Thanks,
- Tom