r198726 - RP18408: If a member template is used as a template template argument, it does

[Richard Smith]

Author: rsmith
Date: Tue Jan  7 19:51:59 2014
New Revision: 198726

URL: http://llvm.org/viewvc/llvm-project?rev=198726&view=rev
Log:
RP18408: If a member template is used as a template template argument, it does
not cause the template specialization to have no linkage.

Modified:
    cfe/trunk/lib/AST/Decl.cpp
    cfe/trunk/test/CodeGenCXX/linkage.cpp

Modified: cfe/trunk/lib/AST/Decl.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/Decl.cpp?rev=198726&r1=198725&r2=198726&view=diff
==============================================================================
--- cfe/trunk/lib/AST/Decl.cpp (original)
+++ cfe/trunk/lib/AST/Decl.cpp Tue Jan  7 19:51:59 2014
@@ -782,11 +782,18 @@ static LinkageInfo getLVForClassMember(c
   // really have linkage, but it's convenient to say they do for the
   // purposes of calculating linkage of pointer-to-data-member
   // template arguments.
+  //
+  // Templates also don't officially have linkage, but since we ignore
+  // the C++ standard and look at template arguments when determining
+  // linkage and visibility of a template specialization, we might hit
+  // a template template argument that way. If we do, we need to
+  // consider its linkage.
   if (!(isa<CXXMethodDecl>(D) ||
         isa<VarDecl>(D) ||
         isa<FieldDecl>(D) ||
         isa<IndirectFieldDecl>(D) ||
-        isa<TagDecl>(D)))
+        isa<TagDecl>(D) ||
+        isa<TemplateDecl>(D)))
     return LinkageInfo::none();
 
   LinkageInfo LV;

Modified: cfe/trunk/test/CodeGenCXX/linkage.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGenCXX/linkage.cpp?rev=198726&r1=198725&r2=198726&view=diff
==============================================================================
--- cfe/trunk/test/CodeGenCXX/linkage.cpp (original)
+++ cfe/trunk/test/CodeGenCXX/linkage.cpp Tue Jan  7 19:51:59 2014
@@ -220,3 +220,11 @@ namespace test17 {
   }
   template int *foo<42>();
 }
+
+// PR18408
+namespace test18 {
+  template<template<typename> class> struct A {};
+  struct B { template<typename> struct C; };
+  void f(A<B::C>) {}
+  // CHECK-DAG: define void @_ZN6test181fENS_1AINS_1B1CEEE(
+}