rspec/rules/S2324/rule.adoc

Flexible array members are most likely to be used in conjunction with dynamic memory allocation.

The presence of flexible array members modifies the behaviour of the ``++sizeof++`` operator in ways that might not be expected by a programmer. The assignment of a structure that contains a flexible array member to another structure of the same type may not behave in the expected manner as it copies only those elements up to but not including the start of the flexible array member.


== Noncompliant Code Example

----
#include <stdlib.h>
struct s
{
  uint16_t len;
  uint32_t data[ ]; // Noncompliant - flexible array member
} str;

struct s *copy ( struct s *s1 )
{
  struct s *s2 = malloc ( sizeof ( struct s ) + ( s1->len * sizeof ( uint32_t ) ) );
  /* Omit malloc ( ) return check for brevity */
  *s2 = *s1; /* Only copies s1->len */
  return s2;
}
----


== See

* MISRA C:2012, 18.7 - Flexible array members shall not be declared.