AUTOSAR C++14 Rule M7-5-2

char * ptr;
 
void foo (void) {
    char varInFoo;
    ptr = &varInFoo; //Noncompliant
}

void bar (void) {
    char varInBar = *ptr;
}

void main() {
    foo();
    bar();
}

The assignment ptr = &varInFoo is noncompliant because the global pointer ptr might be dereferenced outside the function foo, where the variable varInFoo is no longer in scope. For instance, in this example, ptr is dereferenced in the function bar, which is called after foo completes execution.

In this example, address of local objects in the inner scope is assigned to the pointer pointer_outer_scope, which has a greater lifetime.

#include <cstdint>

void foo()
{
	int8_t *pointer_outer_scope;
	{
		int8_t local_var;
		int8_t local_array[ 10 ];
		int8_t *pointer_inner_scope = nullptr;
		pointer_outer_scope = &local_var;                  // Noncompliant
		pointer_outer_scope = local_array;             // Noncompliant
		pointer_inner_scope = &local_var;                  //Compliant
		pointer_outer_scope = pointer_inner_scope;     // Rule does not apply

	}
}

This rule checks trivial and specific instances of potentially danging pointers and references. For example, the assignment pointer_outer_scope = pointer_inner_scope results in a dangling pointer. Because this assignment does not specifically assign the address of a local object to pointer_outer_scope, this rule does not apply.