Why is this an issue?
This rule leads to greater precision in the definition of the function interface. The const qualification shall be applied to the
object pointed to, not to the pointer, since it is the object itself that is being protected.
Noncompliant code example
void myfunc ( int * param1, // object is modified
const int * param2,
int * param3, // Noncompliant
int * param4) // Noncompliant
{
*param1 = *param2 + *param3 + *param4;
}
int main (int argc,
const char * * argv) // Noncompliant
{
return argc;
}
Compliant solution
void myfunc ( int * param1, // object is modified
const int * param2,
const int * param3,
const int * param4)
{
*param1 = *param2 + *param3 + *param4;
}
int main (int argc,
const char * const * argv)
{
return argc;
}
Resources
- MISRA C:2004, 16.7 - A pointer parameter in a function prototype should be declared as pointer to const if the pointer is not used to modify
the addressed object.
- MISRA C++:2008, 7-1-2 - A pointer or reference parameter in a function shall be declared as pointer to const or reference to const if the
corresponding object is not modified.
- MISRA C:2012, 8.13 - A pointer should point to a const-qualified type whenever possible
