--- layout: fc_discuss_archives title: Message 23 from Frama-C-discuss on December 2009 ---
This is a re-implementation of the memset function. It uses void-pointers as in C. typedef unsigned int size_t; typedef unsigned char uint8; /*! * \brief Standard Libc memset() function. * \param[out] pDest Pointer to target buffer of length * \a num bytes. * \param[in] value Value to set in each byte of \a pDest. * \param[in] num Number of bytes in \a pDest to * set to \a value. * \return Pointer to target buffer. */ /*@ requires (\valid((uint8*)pDest +(0..num-1))) && @ (0 <= value <= 255) && @ (0 < num); @ ensures (\forall int i; 0 <= i < num @ ==> (((uint8*)pDest)[i] == value)) && @ (\result == pDest); @*/ void *memset( void *pDest, const int value, const size_t num ) { size_t i; /*@ loop invariant \forall int k; 0 <= k < i @ ==> ((uint8 *)pDest)[k] == (uint8)value; @*/ for( i=0; i < num; i++ ) { ((uint8 *)pDest)[i] = (uint8)value; } return pDest; } When I try to verify it, Jessie reports string.c:31:[jessie] user error: Casting from type struct char_P * to type struct unsigned_char_P * not allowed in logic string.c:31:[jessie] warning: Dropping definition of function memset string.c:19:[jessie] user error: Casting from type struct char_P * to type struct unsigned_char_P * not allowed in logic [jessie] warning: Unsupported feature(s). Jessie plugin can not be used on your code. This error message puzzles me as there are no structs. Can a function that is equivalent to the memset function built into C be verified with Jessie? -Boris