M7-3-6: Refine detection of using within function/class scope

[lcartey]

Affected rules

• M7-3-6

Description

The rule states:

using-directives and using-declarations (excluding class scope or function scope using-declarations) shall not be used in header files.

However, we currently permit both using declarations and using directives in function/class scope - we should refine this.

In addition, some using directives/declarations appear to be "orphaned" in our model - i.e. be located within a function or class, but with a fake parent which is not otherwise connected to the AST. We should exclude these to avoid false positives.

Example

template<typename T>
void foo(T& t){
  using some_namespace::func; // COMPLIANT[FALSE_POSITIVE] - not directly reproducible today
  func(t);
}

template<typename T>
class base{
protected:
  void foo(T);
};

template<typename T>
class derived: base<T> {
public:
  using base::foo; // COMPLIANT[FALSE_POSITIVE]
  void foo(T,T);
};

[rvermeulen]

Resolved FN, but couldn't reproduce FPs in provided test case. No FPs were found in OpenPilot. Anymore information to construct a test case to trigger the second FP?

[knewbury01]

@lcartey thoughts on FP reproduction? I saw a note that you were able to reproduce the FP in the template class at least?

I was thinking maybe it was lack of instantiations in that, but adding this bit still did not allow for recreation

template class derived<int>;
extern derived<int> d;
void use_fun(){
  d.foo(1);
}