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

[Adhemerval Zanella]

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.