include/alloca.h

   1 #ifndef _ALLOCA_H
   2
   3 #include <stdlib/alloca.h>
   4 #include <stackinfo.h>
   5
   6 #undef  __alloca
   7
   8 /* Now define the internal interfaces.  */
   9 extern void *__alloca (size_t __size);
  10
  11 #ifdef  __GNUC__
  12 # define __alloca(size) __builtin_alloca (size)
  13 #endif /* GCC.  */
  14
  15 extern int __libc_use_alloca (size_t size) __attribute__ ((const));
  16 extern int __libc_alloca_cutoff (size_t size) __attribute__ ((const));
  17
  18 #define __MAX_ALLOCA_CUTOFF     65536
  19
  20 #include <allocalim.h>
  21
  22 #if _STACK_GROWS_DOWN
  23 # define extend_alloca(buf, len, newlen) \
  24   (__typeof (buf)) ({ size_t __newlen = (newlen);                             \
  25                       char *__newbuf = __alloca (__newlen);                   \
  26                       if (__newbuf + __newlen == (char *) buf)                \
  27                         len += __newlen;                                      \
  28                       else                                                    \
  29                         len = __newlen;                                       \
  30                       __newbuf; })
  31 #elif _STACK_GROWS_UP
  32 # define extend_alloca(buf, len, newlen) \
  33   (__typeof (buf)) ({ size_t __newlen = (newlen);                             \
  34                       char *__newbuf = __alloca (__newlen);                   \
  35                       char *__buf = (buf);                                    \
  36                       if (__buf + __newlen == __newbuf)                       \
  37                         {                                                     \
  38                           len += __newlen;                                    \
  39                           __newbuf = __buf;                                   \
  40                         }                                                     \
  41                       else                                                    \
  42                         len = __newlen;                                       \
  43                       __newbuf; })
  44 #else
  45 # define extend_alloca(buf, len, newlen) \
  46   __alloca (((len) = (newlen)))
  47 #endif
  48
  49 #if defined stackinfo_get_sp && defined stackinfo_sub_sp
  50 # define alloca_account(size, avar) \
  51   ({ void *old__ = stackinfo_get_sp ();                 \
  52      void *m__ = __alloca (size);                       \
  53      avar += stackinfo_sub_sp (old__);                  \
  54      m__; })
  55 #else
  56 # define alloca_account(size, avar) \
  57   ({ size_t s__ = (size);                   \
  58      avar += s__;                           \
  59      __alloca (s__); })
  60 #endif
  61
  62 #endif