Re: [PATCH 6/6] compat/nedmalloc: Fix compiler warnings on linux

> Ramsay Jones <ramsay@ramsay1.demon.co.uk> writes:
> 
>> On linux, when the build variable USE_NED_ALLOCATOR is set, gcc
>> issues the following warnings:
>>
>>     In file included from compat/nedmalloc/nedmalloc.c:63:
>>     .../malloc.c.h: In function 'mmap_resize':
>>     .../malloc.c.h:3762: warning: implicit declaration of function 'mremap'
>>     .../malloc.c.h: In function 'sys_trim':
>>     .../malloc.c.h:4195: warning: comparison between pointer and integer
>>
>> The warnings are caused by the <sys/mman.h> header not enabling the
>> (conditional) declaration of the mremap() function.  The declaration
>> can be enabled by defining the _GNU_SOURCE symbol prior to including
>> certain system header files. In particular, it may not be sufficient
>> to simply define _GNU_SOURCE just prior to including the <sys/mman.h>
>> header. (e.g. defining the symbol after including <sys/types.h> will
>> be completely ineffective.)
>>
>> In order to suppress the warnings, we define the _GNU_SOURCE symbol
>> at the start of the malloc.c.h header file.
>>
>> Signed-off-by: Ramsay Jones <ramsay@ramsay1.demon.co.uk>
>> ---
> 
> Hmmmm, is this even worth worrying about?  I somehow thought this
> was only meant to replace malloc on non GNU systems...