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


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// REQUIRES: libcxx
// 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 --exit-on-error --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;
}