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 libc_hidden_proto (__libc_alloca_cutoff)
  18
  19 #define __MAX_ALLOCA_CUTOFF     65536
  20
  21 #include <allocalim.h>
  22
  23 #ifndef stackinfo_alloca_round
  24 # define stackinfo_alloca_round(l) (((l) + 15) & -16)
  25 #endif
  26
  27 #if _STACK_GROWS_DOWN
  28 # define extend_alloca(buf, len, newlen) \
  29   (__typeof (buf)) ({ size_t __newlen = stackinfo_alloca_round (newlen);      \
  30                       char *__newbuf = __alloca (__newlen);                   \
  31                       if (__newbuf + __newlen == (char *) (buf))              \
  32                         len += __newlen;                                      \
  33                       else                                                    \
  34                         len = __newlen;                                       \
  35                       __newbuf; })
  36 #elif _STACK_GROWS_UP
  37 # define extend_alloca(buf, len, newlen) \
  38   (__typeof (buf)) ({ size_t __newlen = stackinfo_alloca_round (newlen);      \
  39                       char *__newbuf = __alloca (__newlen);                   \
  40                       char *__buf = (char *) (buf);                           \
  41                       if (__buf + len == __newbuf)                            \
  42                         {                                                     \
  43                           len += __newlen;                                    \
  44                           __newbuf = __buf;                                   \
  45                         }                                                     \
  46                       else                                                    \
  47                         len = __newlen;                                       \
  48                       __newbuf; })
  49 #else
  50 # define extend_alloca(buf, len, newlen) \
  51   __alloca (((len) = (newlen)))
  52 #endif
  53
  54 #if defined stackinfo_get_sp && defined stackinfo_sub_sp
  55 # define alloca_account(size, avar) \
  56   ({ void *old__ = stackinfo_get_sp ();                                       \
  57      void *m__ = __alloca (size);                                             \
  58      avar += stackinfo_sub_sp (old__);                                        \
  59      m__; })
  60 # define extend_alloca_account(buf, len, newlen, avar) \
  61   ({ void *old__ = stackinfo_get_sp ();                                       \
  62      void *m__ = extend_alloca (buf, len, newlen);                            \
  63      avar += stackinfo_sub_sp (old__);                                        \
  64      m__; })
  65 #else
  66 # define alloca_account(size, avar) \
  67   ({ size_t s__ = (size);                                                     \
  68      avar += s__;                                                             \
  69      __alloca (s__); })
  70 # define extend_alloca_account(buf, len, newlen, avar) \
  71   ({ size_t s__ = (newlen);                                                   \
  72      avar += s__;                                                             \
  73      extend_alloca (buf, len, s__); })
  74 #endif
  75
  76 #endif