C++ (Cpp) __CPROVER_POINTER_OFFSET Examples

Example #1

File: new.c Project: danpoe/cbmc

inline void __delete(void *ptr)
{
  __CPROVER_HIDE:;
  // If ptr is NULL, no operation is performed.
  // This is a requirement by the standard, not generosity!
  if(ptr!=0)
  {
    // is it dynamic?
    __CPROVER_assert(__CPROVER_DYNAMIC_OBJECT(ptr),
                     "delete argument must be dynamic object");
    __CPROVER_assert(__CPROVER_POINTER_OFFSET(ptr)==0,
                     "delete argument must have offset zero");

    // catch double delete
    __CPROVER_assert(__CPROVER_deallocated!=ptr, "double delete");

    // catch people who call delete for objects allocated with new[]
    __CPROVER_assert(__CPROVER_malloc_object!=ptr ||
                     !__CPROVER_malloc_is_new_array,
                     "delete of array object");

    // non-deterministically record as deallocated
    __CPROVER_bool record=__VERIFIER_nondet___CPROVER_bool();
    __CPROVER_deallocated=record?ptr:__CPROVER_deallocated;

    // detect memory leaks
    if(__CPROVER_memory_leak==ptr) __CPROVER_memory_leak=0;
  }
}

Example #2

File: stdlib.c Project: ashokkelur/CBMC-With-DSP-C

inline void free(void *ptr)
{
  __CPROVER_HIDE:;
  // If ptr is NULL, no operation is performed.
  if(ptr!=0)
  {
    // is it dynamic?
    __CPROVER_assert(__CPROVER_DYNAMIC_OBJECT(ptr),
                     "free argument is dynamic object");
    __CPROVER_assert(__CPROVER_POINTER_OFFSET(ptr)==0,
                     "free argument has offset zero");

    // catch double free
    if(__CPROVER_deallocated==ptr)
      __CPROVER_assert(0, "double free");
      
    // catch people who try to use free(...) for stuff
    // allocated with new[]
    __CPROVER_assert(__CPROVER_malloc_object!=ptr ||
                     !__CPROVER_malloc_is_new_array,
                     "free called for new[] object");
    
    // non-deterministically record as deallocated
    _Bool record;
    if(record) __CPROVER_deallocated=ptr;
  }
}