Implement semantic checking of static_cast and dynamic_cast.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@58509 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/test/SemaCXX/static-cast.cpp b/test/SemaCXX/static-cast.cpp
new file mode 100644
index 0000000..44b4921
--- /dev/null
+++ b/test/SemaCXX/static-cast.cpp
@@ -0,0 +1,120 @@
+// RUN: clang -fsyntax-only -verify %s
+
+struct A {};
+struct B : public A {};             // Single public base.
+struct C1 : public virtual B {};    // Single virtual base.
+struct C2 : public virtual B {};
+struct D : public C1, public C2 {}; // Diamond
+struct E : private A {};            // Single private base.
+struct F : public C1 {};            // Single path to B with virtual.
+struct G1 : public B {};
+struct G2 : public B {};
+struct H : public G1, public G2 {}; // Ambiguous path to B.
+
+enum Enum { En1, En2 };
+enum Onom { On1, On2 };
+
+// Explicit implicits
+void t_529_2()
+{
+  int i = 1;
+  (void)static_cast<float>(i);
+  double d = 1.0;
+  (void)static_cast<float>(d);
+  (void)static_cast<int>(d);
+  (void)static_cast<char>(i);
+  (void)static_cast<unsigned long>(i);
+  (void)static_cast<int>(En1);
+  (void)static_cast<double>(En1);
+  (void)static_cast<int&>(i);
+  (void)static_cast<const int&>(i);
+
+  int ar[1];
+  (void)static_cast<const int*>(ar);
+  (void)static_cast<void (*)()>(t_529_2);
+
+  (void)static_cast<void*>(0);
+  (void)static_cast<void*>((int*)0);
+  (void)static_cast<volatile const void*>((const int*)0);
+  (void)static_cast<A*>((B*)0);
+  // TryCopyInitialization doesn't handle references yet.
+  (void)static_cast<A&>(*((B*)0));
+  (void)static_cast<const B*>((C1*)0);
+  (void)static_cast<B&>(*((C1*)0));
+  (void)static_cast<A*>((D*)0);
+  (void)static_cast<const A&>(*((D*)0));
+
+  // TODO: User-defined conversions
+
+  // Bad code below
+
+  (void)static_cast<void*>((const int*)0); // expected-error {{static_cast from 'int const *' to 'void *' is not allowed}}
+  //(void)static_cast<A*>((E*)0); // {{static_cast from 'struct E *' to 'struct A *' is not allowed}}
+  //(void)static_cast<A*>((H*)0); // {{static_cast from 'struct H *' to 'struct A *' is not allowed}}
+  (void)static_cast<int>((int*)0); // expected-error {{static_cast from 'int *' to 'int' is not allowed}}
+  (void)static_cast<A**>((B**)0); // expected-error {{static_cast from 'struct B **' to 'struct A **' is not allowed}}
+  (void)static_cast<char&>(i); // expected-error {{static_cast from 'int' to 'char &' is not allowed}}
+}
+
+// Anything to void
+void t_529_4()
+{
+  static_cast<void>(1);
+  static_cast<void>(t_529_4);
+}
+
+// Static downcasts
+void t_529_5_8()
+{
+  (void)static_cast<B*>((A*)0);
+  (void)static_cast<B&>(*((A*)0));
+  (void)static_cast<const G1*>((A*)0);
+  (void)static_cast<const G1&>(*((A*)0));
+
+  // Bad code below
+
+  (void)static_cast<C1*>((A*)0); // expected-error {{static_cast from 'struct A *' to 'struct C1 *' is not allowed}}
+  (void)static_cast<C1&>(*((A*)0)); // expected-error {{static_cast from 'struct A' to 'struct C1 &' is not allowed}}
+  (void)static_cast<D*>((A*)0); // expected-error {{static_cast from 'struct A *' to 'struct D *' is not allowed}}
+  (void)static_cast<D&>(*((A*)0)); // expected-error {{static_cast from 'struct A' to 'struct D &' is not allowed}}
+  (void)static_cast<B*>((const A*)0); // expected-error {{static_cast from 'struct A const *' to 'struct B *' is not allowed}}
+  (void)static_cast<B&>(*((const A*)0)); // expected-error {{static_cast from 'struct A const' to 'struct B &' is not allowed}}
+  // Accessibility is not yet tested
+  //(void)static_cast<E*>((A*)0); // {{static_cast from 'struct A *' to 'struct E *' is not allowed}}
+  //(void)static_cast<E&>(*((A*)0)); // {{static_cast from 'struct A' to 'struct E &' is not allowed}}
+  (void)static_cast<H*>((A*)0); // expected-error {{static_cast from 'struct A *' to 'struct H *' is not allowed}}
+  (void)static_cast<H&>(*((A*)0)); // expected-error {{static_cast from 'struct A' to 'struct H &' is not allowed}}
+  (void)static_cast<E*>((B*)0); // expected-error {{static_cast from 'struct B *' to 'struct E *' is not allowed}}
+  (void)static_cast<E&>(*((B*)0)); // expected-error {{static_cast from 'struct B' to 'struct E &' is not allowed}}
+
+  // TODO: Test inaccessible base in context where it's accessible, i.e.
+  // member function and friend.
+
+  // TODO: Test DR427. This requires user-defined conversions, though.
+}
+
+// Enum conversions
+void t_529_7()
+{
+  (void)static_cast<Enum>(1);
+  (void)static_cast<Enum>(1.0);
+  (void)static_cast<Onom>(En1);
+
+  // Bad code below
+
+  (void)static_cast<Enum>((int*)0); // expected-error {{static_cast from 'int *' to 'enum Enum' is not allowed}}
+}
+
+// Void pointer to object pointer
+void t_529_10()
+{
+  (void)static_cast<int*>((void*)0);
+  (void)static_cast<const A*>((void*)0);
+
+  // Bad code below
+
+  (void)static_cast<int*>((const void*)0); // expected-error {{static_cast from 'void const *' to 'int *' is not allowed}}
+  (void)static_cast<void (*)()>((void*)0); // expected-error {{static_cast from 'void *' to 'void (*)(void)' is not allowed}}
+}
+
+// TODO: Test member pointers.