Recursion carries with it the danger of exceeding available stack space, which can lead to a serious failure. Unless recursion is very tightly controlled, it is not possible to determine before execution what the worst-case stack usage could be.

MISRA-C 2004 Rule 16.2 (required): Functions shall not call themselves, either directly or indirectly.

Recursive function.

This means that recursive function calls cannot be used in safety-related systems. Recursion carries with it the danger of exceeding available stack space, which can be a serious error. Unless recursion is very tightly controlled, it is not possible to determine before execution what the worst-case stack usage could be.

MISRA-C++ 2008 Rule 7-5-4 (advisory): Functions should not call themselves, either directly or indirectly.

Rationale

Unbounded recursion is likely to lead to a stack over-flow and may impact system timings. This is also the case for an iterative algorithm.

Example

int32_t fn ( int32_t x )
{
   if ( x > 0 )
   {
      x = x * fn ( x — 1 ); // Non-compliant
   }
   return ( x );
}
// File1.cpp
int32_t fn_2 ( int32_t x )
{
   if ( x > 0 )
   {
      x = x * fn_3 ( x — 1 ); // Non-compliant
   }
   return ( x );
}
// File2.cpp
int32_t fn_3 ( int32_t x )
{
   if ( x == 0 )
   {
       x = x * fn_2 ( x — 1 ); // Non-compliant
   }
   return ( x );
}