unusedPrivateFunction and unusedFunction false positives

[Nikita Leontiev]

cppcheck 2.22.0 generates unusedPrivateFunction and unusedFunction for the following code:

#define CASE(msg, handler) \
    case msg: CASE_##msg((handler))
#define MSG1 1
#define CASE_MSG1(handler) handler()

class Object
{
private:
    int m_num;
public:
    Object() : m_num(0) {}
    static void msg_proc(int msg, void *context)
    {
        switch (msg)
        {
            CASE(MSG1, reinterpret_cast<Object*>(context)->msg1_handler);
        }
    }
private:
    void msg1_handler()
    {
        m_num = 1;
    }
};

int main()
{
    Object obj;
    Object::msg_proc(MSG1, reinterpret_cast<void*>(&obj));
    return 0;
}

test\main.cpp:20:7: style: Unused private function: 'Object::msg1_handler' [unusedPrivateFunction]
 void msg1_handler()
      ^
test\main.cpp:20:7: note: Unused private function: 'Object::msg1_handler'
 void msg1_handler()
      ^
test\main.cpp:20:7: note: Unused private function: 'Object::msg1_handler'
 void msg1_handler()
      ^
test\main.cpp:20:7: style: The function 'msg1_handler' is never used. [unusedFunction]
 void msg1_handler()
      ^

Without parentheses around handler, warnings are not generated:

#define CASE(msg, handler) \
    case msg: CASE_##msg(handler)

[CHR]

Added here: https://trac.cppcheck.net/ticket/15058