grcypt.h should use __alloc_size__ attribute.

[Kant]

http://gcc.gnu.org/onlinedocs/gcc-4.7.0/gcc/Function-Attributes.html#Function-Attributes

i.e

#define _GCRY_GCC_ATTR_ALLOC_SIZE(params) __attribute__
((__alloc_size__ params))

void *gcry_malloc (size_t n) _GCRY_GCC_ATTR_MALLOC
_GCRY_GCC_ATTR_ALLOC_SIZE ((1));

and so on.