toolchain/gcc/newlib/libc/reent/sbrkr.c

   1 /* Reentrant version of sbrk system call. */
   2
   3 #include <reent.h>
   4 #include <unistd.h>
   5 #include <_syslist.h>
   6
   7 /* Some targets provides their own versions of these functions.  Those
   8    targets should define REENTRANT_SYSCALLS_PROVIDED in TARGET_CFLAGS.  */
   9
  10 #ifdef _REENT_ONLY
  11 #ifndef REENTRANT_SYSCALLS_PROVIDED
  12 #define REENTRANT_SYSCALLS_PROVIDED
  13 #endif
  14 #endif
  15
  16 /* If MALLOC_PROVIDED is defined, we don't need this function.  */
  17
  18 #if defined (REENTRANT_SYSCALLS_PROVIDED) || defined (MALLOC_PROVIDED)
  19
  20 int _dummy_sbrk_syscalls = 1;
  21
  22 #else
  23
  24 /* We use the errno variable used by the system dependent layer.  */
  25 #undef errno
  26 extern int errno;
  27
  28 /*
  29 FUNCTION
  30         <<_sbrk_r>>---Reentrant version of sbrk
  31
  32 INDEX
  33         _sbrk_r
  34
  35 ANSI_SYNOPSIS
  36         #include <reent.h>
  37         void *_sbrk_r(struct _reent *<[ptr]>, ptrdiff_t <[incr]>);
  38
  39 TRAD_SYNOPSIS
  40         #include <reent.h>
  41         void *_sbrk_r(<[ptr]>, <[incr]>)
  42         struct _reent *<[ptr]>;
  43         ptrdiff_t <[incr]>;
  44
  45 DESCRIPTION
  46         This is a reentrant version of <<sbrk>>.  It
  47         takes a pointer to the global data block, which holds
  48         <<errno>>.
  49 */
  50
  51 void *
  52 _DEFUN (_sbrk_r, (ptr, incr),
  53      struct _reent *ptr _AND
  54      ptrdiff_t incr)
  55 {
  56   char *ret;
  57   void *_sbrk(ptrdiff_t);
  58
  59   errno = 0;
  60   if ((ret = (char *)(_sbrk (incr))) == (void *) -1 && errno != 0)
  61     ptr->_errno = errno;
  62   return ret;
  63 }
  64
  65 #endif /* ! defined (REENTRANT_SYSCALLS_PROVIDED) */