Error: conflicting types for ‘sbrk’

[Larissa Braz]

Hi,

 I found the following compilation error:

xmalloc.c:51:14: error: conflicting types for ‘sbrk’
 extern char *sbrk();
              ^
In file included from xmalloc.c:29:0:
/usr/include/unistd.h:1043:14: note: previous declaration of ‘sbrk’ was here
 extern void *sbrk (intptr_t __delta) __THROW;
              ^

The code where it occurs is bellow.

//unistd.h
#if (defined __USE_XOPEN_EXTENDED && !defined __USE_XOPEN2K) \
    || defined __USE_MISC
extern void *sbrk (intptr_t __delta) __THROW;
#endif

//xmalloc.c
...
#if defined (HAVE_UNISTD_H)
#  include <unistd.h>
#endif
...
#if defined (HAVE_SBRK) && !HAVE_DECL_SBRK
extern char *sbrk();
#endif

I'm using gcc version 4.8.4 and Ubuntu 14.04 LTS.

Thank you,
-- 
Larissa Braz