include/alloca.h

   1 #ifndef _ALLOCA_H
   2
   3 #include <stdlib/alloca.h>
   4
   5 # ifndef _ISOMAC
   6
   7 #include <stackinfo.h>
   8
   9 #undef  __alloca
  10
  11 /* Now define the internal interfaces.  */
  12 extern void *__alloca (size_t __size);
  13
  14 #ifdef  __GNUC__
  15 # define __alloca(size) __builtin_alloca (size)
  16 #endif /* GCC.  */
  17
  18 extern int __libc_use_alloca (size_t size) __attribute__ ((const));
  19 extern int __libc_alloca_cutoff (size_t size) __attribute__ ((const));
  20 libc_hidden_proto (__libc_alloca_cutoff)
  21
  22 #define __MAX_ALLOCA_CUTOFF     65536
  23
  24 #include <allocalim.h>
  25
  26 #ifndef stackinfo_alloca_round
  27 # define stackinfo_alloca_round(l) (((l) + 15) & -16)
  28 #endif
  29
  30 #if _STACK_GROWS_DOWN
  31 # define extend_alloca(buf, len, newlen) \
  32   (__typeof (buf)) ({ size_t __newlen = stackinfo_alloca_round (newlen);      \
  33                       char *__newbuf = __alloca (__newlen);                   \
  34                       if (__newbuf + __newlen == (char *) (buf))              \
  35                         len += __newlen;                                      \
  36                       else                                                    \
  37                         len = __newlen;                                       \
  38                       __newbuf; })
  39 #elif _STACK_GROWS_UP
  40 # define extend_alloca(buf, len, newlen) \
  41   (__typeof (buf)) ({ size_t __newlen = stackinfo_alloca_round (newlen);      \
  42                       char *__newbuf = __alloca (__newlen);                   \
  43                       char *__buf = (char *) (buf);                           \
  44                       if (__buf + len == __newbuf)                            \
  45                         {                                                     \
  46                           len += __newlen;                                    \
  47                           __newbuf = __buf;                                   \
  48                         }                                                     \
  49                       else                                                    \
  50                         len = __newlen;                                       \
  51                       __newbuf; })
  52 #else
  53 # define extend_alloca(buf, len, newlen) \
  54   __alloca (((len) = (newlen)))
  55 #endif
  56
  57 #if defined stackinfo_get_sp && defined stackinfo_sub_sp
  58 # define alloca_account(size, avar) \
  59   ({ void *old__ = stackinfo_get_sp ();                                       \
  60      void *m__ = __alloca (size);                                             \
  61      avar += stackinfo_sub_sp (old__);                                        \
  62      m__; })
  63 # define extend_alloca_account(buf, len, newlen, avar) \
  64   ({ void *old__ = stackinfo_get_sp ();                                       \
  65      void *m__ = extend_alloca (buf, len, newlen);                            \
  66      avar += stackinfo_sub_sp (old__);                                        \
  67      m__; })
  68 #else
  69 # define alloca_account(size, avar) \
  70   ({ size_t s__ = (size);                                                     \
  71      avar += s__;                                                             \
  72      __alloca (s__); })
  73 # define extend_alloca_account(buf, len, newlen, avar) \
  74   ({ size_t s__ = (newlen);                                                   \
  75      avar += s__;                                                             \
  76      extend_alloca (buf, len, s__); })
  77 #endif
  78
  79 # endif /* !_ISOMAC */
  80 #endif