2 files changed, 57 insertions, 1 deletions
diff --git a/clang/test/CXX/temp/temp.spec/temp.explicit/p3.cpp b/clang/test/CXX/temp/temp.spec/temp.explicit/p3.cpp
index e9758bcdec2..48c42c399a4 100644
--- a/clang/test/CXX/temp/temp.spec/temp.explicit/p3.cpp
+++ b/clang/test/CXX/temp/temp.spec/temp.explicit/p3.cpp
@@ -2,8 +2,9 @@
 
 // A declaration of a function template shall be in scope at the point of the 
 // explicit instantiation of the function template.
-template<typename T> void f0(T) { }
+template<typename T> void f0(T);
 template void f0(int); // okay
+template<typename T> void f0(T) { }
 
 // A definition of the class or class template containing a member function 
 // template shall be in scope at the point of the explicit instantiation of 
@@ -47,3 +48,27 @@ template X2<int>::X2(); // expected-error{{not an instantiation}}
 template X2<int>::X2(const X2&); // expected-error{{not an instantiation}}
 template X2<int>::~X2(); // expected-error{{not an instantiation}}
 template X2<int> &X2<int>::operator=(const X2<int>&); // expected-error{{not an instantiation}}
+
+
+// A definition of a class template is sufficient to explicitly
+// instantiate a member of the class template which itself is not yet defined.
+namespace PR7979 {
+  template <typename T> struct S {
+    void f();
+    static void g();
+    static int i;
+    struct S2 {
+      void h();
+    };
+  };
+
+  template void S<int>::f();
+  template void S<int>::g();
+  template int S<int>::i;
+  template void S<int>::S2::h();
+
+  template <typename T> void S<T>::f() {}
+  template <typename T> void S<T>::g() {}
+  template <typename T> int S<T>::i;
+  template <typename T> void S<T>::S2::h() {}
+}
diff --git a/clang/test/CodeGenCXX/explicit-instantiation.cpp b/clang/test/CodeGenCXX/explicit-instantiation.cpp
index 24d1a673922..b82958568a8 100644
--- a/clang/test/CodeGenCXX/explicit-instantiation.cpp
+++ b/clang/test/CodeGenCXX/explicit-instantiation.cpp
@@ -1,5 +1,8 @@
 // RUN: %clang_cc1 -emit-llvm -triple i686-pc-linux-gnu -o - %s | FileCheck %s
 
+// This check logically is attached to 'template int S<int>::i;' below.
+// CHECK: @_ZN1SIiE1iE = weak global i32
+
 template<typename T, typename U, typename Result>
 struct plus {
   Result operator()(const T& t, const U& u) const;
@@ -12,3 +15,31 @@ Result plus<T, U, Result>::operator()(const T& t, const U& u) const {
 
 // CHECK: define weak_odr i32 @_ZNK4plusIillEclERKiRKl
 template struct plus<int, long, long>;
+
+// Check that we emit definitions from explicit instantiations even when they
+// occur prior to the definition itself.
+template <typename T> struct S {
+  void f();
+  static void g();
+  static int i;
+  struct S2 {
+    void h();
+  };
+};
+
+// CHECK: define weak_odr void @_ZN1SIiE1fEv
+template void S<int>::f();
+
+// CHECK: define weak_odr void @_ZN1SIiE1gEv
+template void S<int>::g();
+
+// See the check line at the top of the file.
+template int S<int>::i;
+
+// CHECK: define weak_odr void @_ZN1SIiE2S21hEv
+template void S<int>::S2::h();
+
+template <typename T> void S<T>::f() {}
+template <typename T> void S<T>::g() {}
+template <typename T> int S<T>::i;
+template <typename T> void S<T>::S2::h() {}