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

llvm-svn: 193144

1 files changed, 7 insertions, 6 deletions

diff --git a/clang/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp b/clang/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
index 97bf00303bb..5f43ea2c27a 100644
--- a/clang/test/SemaTemplate/instantiate-exception-spec-cxx11.cpp
+++ b/clang/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}}
   }