test/SemaCXX/warn-pure-virtual-call-from-ctor-dtor.cpp

// RUN: %clang_cc1 %s -fsyntax-only -verify -Wcall-to-pure-virtual-from-ctor-dtor
struct A {
  A() { f(); } // expected-warning {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the constructor of 'A'}}
  ~A() { f(); } // expected-warning {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the destructor of 'A'}}

  virtual void f() = 0; // expected-note 2 {{'f' declared here}}
};

// Don't warn (or note) when calling the function on a pointer. (PR10195)
struct B {
  A *a;
  B() { a->f(); };
  ~B() { a->f(); };
};

// Don't warn if the call is fully qualified. (PR23215)
struct C {
    virtual void f() = 0;
    C() {
        C::f();
    }
};

template <typename T> struct TA {
  TA() { f(); }  // expected-warning {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the constructor of 'TA<float>'}}
  ~TA() { f(); } // expected-warning {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the destructor of 'TA<float>'}}

  virtual void f() = 0; // expected-note 2{{'f' declared here}}
};

template <> struct TA<int> {
  TA() { f(); }
  ~TA() { f(); }
  void f();
};

template <> struct TA<long> {
  TA() { f(); }         // expected-warning {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the constructor of 'TA<long>'}}
  ~TA() { f(); }        // expected-warning {{call to pure virtual member function 'f' has undefined behavior; overrides of 'f' in subclasses are not available in the destructor of 'TA<long>'}}
  virtual void f() = 0; // expected-note 2{{'f' declared here}}
};

struct TB : TA<float> { // expected-note {{in instantiation of member function 'TA<float>::TA' requested here}}
  void f() override;    // expected-note@-1 {{in instantiation of member function 'TA<float>::~TA' requested here}}
};
TB tb;

struct TC : TA<int> {}; // ok
TC tc; // ok

struct TD : TA<long> {
  void f() override;
};
TD td;