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 #if _STACK_GROWS_DOWN
  24 # define extend_alloca(buf, len, newlen) \
  25   (__typeof (buf)) ({ size_t __newlen = (newlen);                             \
  26                       char *__newbuf = __alloca (__newlen);                   \
  27                       if (__newbuf + __newlen == (char *) buf)                \
  28                         len += __newlen;                                      \
  29                       else                                                    \
  30                         len = __newlen;                                       \
  31                       __newbuf; })
  32 #elif _STACK_GROWS_UP
  33 # define extend_alloca(buf, len, newlen) \
  34   (__typeof (buf)) ({ size_t __newlen = (newlen);                             \
  35                       char *__newbuf = __alloca (__newlen);                   \
  36                       char *__buf = (buf);                                    \
  37                       if (__buf + __newlen == __newbuf)                       \
  38                         {                                                     \
  39                           len += __newlen;                                    \
  40                           __newbuf = __buf;                                   \
  41                         }                                                     \
  42                       else                                                    \
  43                         len = __newlen;                                       \
  44                       __newbuf; })
  45 #else
  46 # define extend_alloca(buf, len, newlen) \
  47   __alloca (((len) = (newlen)))
  48 #endif
  49
  50 #if defined stackinfo_get_sp && defined stackinfo_sub_sp
  51 # define alloca_account(size, avar) \
  52   ({ void *old__ = stackinfo_get_sp ();                                       \
  53      void *m__ = __alloca (size);                                             \
  54      avar += stackinfo_sub_sp (old__);                                        \
  55      m__; })
  56 # define extend_alloca_account(buf, len, newlen, avar) \
  57   ({ void *old__ = stackinfo_get_sp ();                                       \
  58      void *m__ = extend_alloca (buf, len, newlen);                            \
  59      avar += stackinfo_sub_sp (old__);                                        \
  60      m__; })
  61 #else
  62 # define alloca_account(size, avar) \
  63   ({ size_t s__ = (size);                                                     \
  64      avar += s__;                                                             \
  65      __alloca (s__); })
  66 # define extend_alloca_account(buf, len, newlen, avar) \
  67   ({ size_t s__ = (newlen);                                                   \
  68      avar += s__;                                                             \
  69      extend_alloca (buf, len, s__); })
  70 #endif
  71
  72 #endif