From b2dc2df7d2c8eccb1aecfc09726b69dcd9aba28f Mon Sep 17 00:00:00 2001
From: Stuart Hastings <stuart@apple.com>
Date: Tue, 23 Mar 2010 18:39:23 +0000
Subject: [PATCH] Test case for llvm-gcc r99305.  Radar 7659636.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99306 91177308-0d34-0410-b5e6-96231b3b80d8
---
 .../2010-03-22-empty-baseclass.cpp            | 134 ++++++++++++++++++
 1 file changed, 134 insertions(+)
 create mode 100644 test/FrontendC++/2010-03-22-empty-baseclass.cpp

diff --git a/test/FrontendC++/2010-03-22-empty-baseclass.cpp b/test/FrontendC++/2010-03-22-empty-baseclass.cpp
new file mode 100644
index 00000000000..b6bdea40c3f
--- /dev/null
+++ b/test/FrontendC++/2010-03-22-empty-baseclass.cpp
@@ -0,0 +1,134 @@
+// RUN: %llvmgxx -S -emit-llvm %s -o - -O2 | FileCheck %s
+namespace boost {
+  namespace detail {
+    template <typename T> struct cv_traits_imp {};
+    template <typename T> struct cv_traits_imp<T*> {typedef T unqualified_type;};
+  }
+}
+namespace mpl_ {}
+namespace boost {
+  namespace mpl {using namespace mpl_;}
+  template< typename T > struct remove_cv {typedef typename boost::detail::cv_traits_imp<T*>::unqualified_type type;};
+  namespace type_traits {
+    typedef char yes_type;
+    struct no_type {char padding[8];};
+  }
+}
+namespace mpl_ {
+  template< bool C_ > struct bool_;
+  typedef bool_<true> true_;
+  typedef bool_<false> false_;
+  template< bool C_ > struct bool_ {static const bool value = C_;};
+  template< typename T, T N > struct integral_c;
+}
+namespace boost{
+  template <class T, T val>   struct integral_constant :
+    public mpl::integral_c<T, val> {};
+  template<> struct integral_constant<bool,true> : public mpl::true_ {};
+  template<> struct integral_constant<bool,false> : public mpl::false_ {};
+  namespace type_traits {
+    template <bool b1, bool b2, bool b3 = false, bool b4 = false,
+              bool b5 = false, bool b6 = false, bool b7 = false> struct ice_or;
+    template <bool b1, bool b2, bool b3, bool b4, bool b5, bool b6, bool b7>
+    struct ice_or {static const bool value = true; };
+    template <> struct ice_or<false, false, false, false, false, false, false>
+    {static const bool value = false;};
+    template <bool b1, bool b2, bool b3 = true, bool b4 = true, bool b5 = true,
+              bool b6 = true, bool b7 = true> struct ice_and;
+    template <bool b1, bool b2, bool b3, bool b4, bool b5, bool b6, bool b7>
+    struct ice_and {static const bool value = false;};
+    template <> struct ice_and<true, true, true, true, true, true, true>
+    {static const bool value = true;};
+    template <bool b> struct ice_not {static const bool value = true;};
+  };
+  namespace detail {
+    template <typename T> struct is_union_impl {static const bool value = false;};
+  }
+  template< typename T > struct is_union :
+  ::boost::integral_constant<bool, ::boost::detail::is_union_impl<T>::value> {};
+  namespace detail {
+    template <class U> ::boost::type_traits::yes_type is_class_tester(void(U::*)(void));
+    template <class U> ::boost::type_traits::no_type is_class_tester(...);
+    template <typename T> struct is_class_impl {
+      static const bool value = (::boost::type_traits::ice_and< sizeof(is_class_tester<T>(0))
+                                 == sizeof(::boost::type_traits::yes_type),
+                                 ::boost::type_traits::ice_not< ::boost::is_union<T>::value >::value >::value);};
+}
+  template<typename T> struct is_class:
+  ::boost::integral_constant<bool,::boost::detail::is_class_impl<T>::value> {  };
+namespace detail {
+  template <typename T> struct empty_helper_t1: public T {int i[256];};
+  struct empty_helper_t2 {int i[256];};
+  template <typename T, bool is_a_class = false> struct empty_helper
+  {static const bool value = false;};
+  template <typename T> struct empty_helper<T, true>
+  {static const bool value = (sizeof(empty_helper_t1<T>) == sizeof(empty_helper_t2));};
+  template <typename T> struct is_empty_impl {
+    typedef typename remove_cv<T>::type cvt;
+    static const bool value = (::boost::type_traits::ice_or< ::boost::detail::empty_helper
+                               <cvt,::boost::is_class<T>::value>::value, false>::value);
+  };
+}
+template<typename T> struct is_empty:
+::boost::integral_constant<bool,::boost::detail::is_empty_impl<T>::value> {};
+template<typename T, typename U > struct is_same:
+::boost::integral_constant<bool,false> {};
+template<typename T> struct call_traits {typedef T& reference;};
+namespace details {
+  template <class T1, class T2, bool IsSame, bool FirstEmpty, bool SecondEmpty>
+  struct compressed_pair_switch;
+  template <class T1, class T2>
+  struct compressed_pair_switch<T1, T2, false, true, false>
+  {static const int value = 1;};
+  template <class T1, class T2, int Version> class compressed_pair_imp;
+  template <class T1, class T2> class compressed_pair_imp<T1, T2, 1>:
+  protected ::boost::remove_cv<T1>::type {
+  public:
+    typedef T1 first_type;
+    typedef T2 second_type;
+    typedef typename call_traits<first_type>::reference first_reference;
+    typedef typename call_traits<second_type>::reference second_reference;
+    first_reference first() {return *this;}
+    second_reference second() {return second_;}
+    second_type second_;
+  };
+}
+template <class T1, class T2> class compressed_pair:
+  private ::boost::details::compressed_pair_imp<T1, T2, ::boost::details::compressed_pair_switch<
+                                                          T1, T2, ::boost::is_same<typename remove_cv<T1>::type,
+                                                                                   typename remove_cv<T2>::type>::value,
+                                                          ::boost::is_empty<T1>::value, ::boost::is_empty<T2>::value>::value>
+  {
+  private:
+    typedef details::compressed_pair_imp<T1, T2, ::boost::details::compressed_pair_switch<
+                                                   T1, T2, ::boost::is_same<typename remove_cv<T1>::type,
+                                                                            typename remove_cv<T2>::type>::value,
+                                                                              ::boost::is_empty<T1>::value, ::boost::is_empty<T2>::value>::value> base;
+  public:
+    typedef T1 first_type;
+    typedef T2 second_type;
+    typedef typename call_traits<first_type>::reference first_reference;
+    typedef typename call_traits<second_type>::reference second_reference;
+    first_reference first() {return base::first();}
+    second_reference second() {return base::second();}
+  };
+}
+struct empty_base_t {};
+struct empty_t : empty_base_t {};
+typedef boost::compressed_pair<empty_t, int> data_t;
+extern "C" {int printf(const char * , ...);}
+extern "C" {void abort(void);}
+int main (int argc, char * const argv[]) {
+  data_t x;
+  x.second() = -3;
+  // This store should be elided:
+  x.first() = empty_t();
+  // If x.second() has been clobbered by the elided store, fail.
+  if (x.second() != -3) {
+    printf("x.second() was clobbered\n");
+    // CHECK-NOT: x.second() was clobbered
+    abort();
+  }
+  return 0;
+}
+// CHECK: ret i32