[PATCH v4 02/10] mtrace: Deprecate mallwatch and tr_break

[Siddhesh Poyarekar]

On 7/3/21 2:12 AM, Adhemerval Zanella wrote:
> 
> 
> On 02/07/2021 17:37, Tulio Magno Quites Machado Filho via Libc-alpha wrote:
>> Siddhesh Poyarekar via Libc-alpha <libc-alpha@sourceware.org> writes:
>>
>>> The variable and function pair appear to provide a way for users to
>>> set conditional breakpoints in mtrace when a specific address is
>>> returned by the allocator.  This can be achieved by using conditional
>>> breakpoints in gdb so it is redundant.  There is no documentation of
>>> this interface in the manual either, so it appears to have been a hack
>>> that got added to debug malloc.  Deprecate these symbols and do not
>>> call tr_break anymore.
>>
>> I noticed new build failures on ppc64le after this patch when using GCC 8 and 9.
>>
>> /tmp/ccg1QEe7.s: Assembler messages:
>> /tmp/ccg1QEe7.s: Error: `__SImallwatch_0' can't be equated to common symbol `mallwatch'
>>
>> I can't reproduce the issue when using GCC 10 or newer.
>>
> 
> I think we will need to use __attribute__ ((nocommon)) on mallwatch.
> 

Thanks for looking into it Adhemerval.  Tulio, can you please check if 
that fixes the build and if it does, push a patch with that?  x86_64 
continues to build fine with the attribute.

Thanks,
Siddhesh