Silently drop dependent friend function template specializations,

since we have absolutely no way to match them when they are declared
nor do we have a way to represent these parsed-but-not-checked friend
declarations.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@99407 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 22 insertions, 5 deletions

diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp
index e802018c9f..e4c930e2f8 100644
--- a/lib/Sema/SemaDecl.cpp
+++ b/lib/Sema/SemaDecl.cpp
@@ -3130,10 +3130,17 @@ Sema::ActOnFunctionDeclarator(Scope* S, Declarator& D, DeclContext* DC,
   }
 
   if (isFunctionTemplateSpecialization) {
-      if (CheckFunctionTemplateSpecialization(NewFD,
-                               (HasExplicitTemplateArgs ? &TemplateArgs : 0),
-                                              Previous))
-        NewFD->setInvalidDecl();
+    if (isFriend && NewFD->getType()->isDependentType()) {
+      // FIXME: When we see a friend of a function template
+      // specialization with a dependent type, we can't match it now;
+      // for now, we just drop it, until we have a reasonable way to
+      // represent the parsed-but-not-matched friend function template
+      // specialization in the AST.
+      return 0;
+    } else if (CheckFunctionTemplateSpecialization(NewFD,
+                                   (HasExplicitTemplateArgs ? &TemplateArgs : 0),
+                                                 Previous))
+      NewFD->setInvalidDecl();
   } else if (isExplicitSpecialization && isa<CXXMethodDecl>(NewFD) &&
              CheckMemberSpecialization(NewFD, Previous))
     NewFD->setInvalidDecl();
diff --git a/test/CXX/temp/temp.decls/temp.friend/p1.cpp b/test/CXX/temp/temp.decls/temp.friend/p1.cpp
index 0f18e76f52..277106c2bd 100644
--- a/test/CXX/temp/temp.decls/temp.friend/p1.cpp
+++ b/test/CXX/temp/temp.decls/temp.friend/p1.cpp
@@ -1,5 +1,4 @@
 // RUN: %clang_cc1 -faccess-control -verify -emit-llvm-only %s
-
 template <typename T> struct Num {
   T value_;
 
@@ -117,3 +116,14 @@ namespace test3 {
   template class User<int>; // expected-note {{requested here}}
 
 }
+
+namespace Dependent {
+  template<typename T, typename Traits> class X;
+  template<typename T, typename Traits> 
+  X<T, Traits> operator+(const X<T, Traits>&, const T*);
+
+  template<typename T, typename Traits> class X {
+    typedef typename Traits::value_type value_type;
+    friend X operator+<>(const X&, const value_type*);
+  };
+}