Sema: Do not allow template declarations inside local classes

Summary:
Enforce the rule in C++11 [temp.mem]p2 that local classes cannot have
member templates.

This fixes PR16947.

N.B.  C++14 has slightly different wording to afford generic lambdas
declared inside of functions.

Fun fact:  Some formulations of local classes with member templates
would cause clang to crash during Itanium mangling, such as the
following:

void outer_mem() {
  struct Inner {
    template <typename = void>
    struct InnerTemplateClass {
      static void itc_mem() {}
    };
  };
  Inner::InnerTemplateClass<>::itc_mem();
}

Reviewers: eli.friedman, rsmith, doug.gregor, faisalv

Reviewed By: doug.gregor

CC: cfe-commits, ygao

Differential Revision: http://llvm-reviews.chandlerc.com/D1866

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193144 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 7 insertions, 105 deletions

diff --git a/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp b/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
index 97bf00303b..5f43ea2c27 100644
--- a/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
+++ b/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
@@ -44,13 +44,14 @@ namespace dr1330_example {
     A<int>().f(42);
   }
 
+  struct S {
+    template<typename T>
+    static int f() noexcept(noexcept(A<T>().f("boo!"))) { return 0; } // \
+    // expected-note {{instantiation of exception spec}}
+    typedef decltype(f<S>()) X;
+  };
+
   int test2() {
-    struct S {
-      template<typename T>
-      static int f() noexcept(noexcept(A<T>().f("boo!"))) { return 0; } // \
-      // expected-note {{instantiation of exception spec}}
-      typedef decltype(f<S>()) X;
-    };
     S().f<S>(); // ok
     S().f<int>(); // expected-note {{instantiation of exception spec}}
   }
diff --git a/test/SemaTemplate/local-member-templates.cpp b/test/SemaTemplate/local-member-templates.cpp
deleted file mode 100644
index 847d483a00..0000000000
--- a/test/SemaTemplate/local-member-templates.cpp
+++ /dev/null
@@ -1,99 +0,0 @@
-// RUN: %clang_cc1 -std=c++1y -verify %s
-// RUN: %clang_cc1 -std=c++1y -verify %s -fdelayed-template-parsing
-
-namespace nested_local_templates_1 {
-
-template <class T> struct Outer {
-  template <class U> int outer_mem(T t, U u) {
-    struct Inner {
-      template <class V> int inner_mem(T t, U u, V v) {
-        struct InnerInner {
-          template <class W> int inner_inner_mem(W w, T t, U u, V v) {
-            return 0;
-          }
-        };
-        InnerInner().inner_inner_mem("abc", t, u, v);
-        return 0;
-      }
-    };
-    Inner i;
-    i.inner_mem(t, u, 3.14);
-    return 0;
-  }
-
-  template <class U> int outer_mem(T t, U *u);
-};
-
-template int Outer<int>::outer_mem(int, char);
-
-template <class T> template <class U> int Outer<T>::outer_mem(T t, U *u) {
-  struct Inner {
-    template <class V>
-    int inner_mem(T t, U u, V v) { //expected-note{{candidate function}}
-      struct InnerInner {
-        template <class W> int inner_inner_mem(W w, T t, U u, V v) { return 0; }
-      };
-      InnerInner().inner_inner_mem("abc", t, u, v);
-      return 0;
-    }
-  };
-  Inner i;
-  i.inner_mem(t, U{}, i);
-  i.inner_mem(t, u, 3.14); //expected-error{{no matching member function for call to 'inner}}
-  return 0;
-}
-
-template int Outer<int>::outer_mem(int, char *); //expected-note{{in instantiation of function}}
-
-} // end ns
-
-namespace nested_local_templates_2 {
-
-template <class T> struct Outer {
-  template <class U> void outer_mem(T t, U u) {
-    struct Inner {
-      template <class V> struct InnerTemplateClass {
-        template <class W>
-        void itc_mem(T t, U u, V v, W w) { //expected-note{{candidate function}}
-          struct InnerInnerInner {
-            template <class X> void iii_mem(X x) {}
-          };
-          InnerInnerInner i;
-          i.iii_mem("abc");
-        }
-      };
-    };
-    Inner i;
-    typename Inner::template InnerTemplateClass<Inner> ii;
-    ii.itc_mem(t, u, i, "jim");
-    ii.itc_mem(t, u, 0, "abd"); //expected-error{{no matching member function}}
-  }
-};
-
-template void
-Outer<int>::outer_mem(int, char); //expected-note{{in instantiation of}}
-
-}
-
-namespace more_nested_local_templates {
-
-int test() {
-  struct Local {
-    template<class U> void foo(U u) {
-      struct Inner {
-        template<class A> 
-        auto operator()(A a, U u2) -> U {
-          return u2;
-        };
-      };
-      Inner GL; 
-      GL('a', u );
-      GL(3.14, u );
-    }
-  };
-  Local l;
-  l.foo("nmabc");
-  return 0;
-}
-int t = test();
-}
\ No newline at end of file