test/CXX/symex/libc++/dynamic_cast.cpp


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// REQUIRES: not-msan
// Disabling msan because it times out on CI
// REQUIRES: libcxx
// REQUIRES: uclibc
// RUN: %clangxx %s -emit-llvm %O0opt -c -std=c++11 -I "%libcxx_include" -g -nostdinc++ -o %t1.bc
// RUN: rm -rf %t.klee-out
// RUN: %klee --output-dir=%t.klee-out --libc=uclibc --libcxx %t1.bc

// Copied from 'http://en.cppreference.com/w/cpp/language/dynamic_cast'

struct V {
  virtual void f(){}; // must be polymorphic to use runtime-checked dynamic_cast
};
struct A : virtual V {};
struct B : virtual V {
  B(V *v, A *a) {
    // casts during construction (see the call in the constructor of D below)
    dynamic_cast<B *>(v); // well-defined: v of type V*, V base of B, results in B*
    dynamic_cast<B *>(a); // undefined behavior: a has type A*, A not a base of B
  }
};
struct D : A, B {
  D() : B((A *)this, this) {}
};

struct Base {
  virtual ~Base() {}
};

struct Derived : Base {
  virtual void name() {}
};

int main() {
  D d;                             // the most derived object
  A &a = d;                        // upcast, dynamic_cast may be used, but unnecessary
  D &new_d = dynamic_cast<D &>(a); // downcast
  B &new_b = dynamic_cast<B &>(a); // sidecast

  Base *b1 = new Base;
  if (Derived *d = dynamic_cast<Derived *>(b1)) {
    d->name(); // safe to call
  }

  Base *b2 = new Derived;
  if (Derived *d = dynamic_cast<Derived *>(b2)) {
    d->name(); // safe to call
  }

  delete b1;
  delete b2;
}