From aff37b48f1362dd29cc481dadebf07900ce79248 Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Thu, 12 May 2011 00:06:17 +0000
Subject: [PATCH] Fix PR9902: correctly substitute alias templates within the
 template in which they are defined: provide an empty list of arguments for
 each containing template context during substitution.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@131211 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaTemplate.cpp |  3 +++
 test/SemaCXX/PR9902.cpp   | 28 ++++++++++++++++++++++++++++
 2 files changed, 31 insertions(+)
 create mode 100644 test/SemaCXX/PR9902.cpp

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index a9b8af28c7..5d93067a95 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -1855,6 +1855,9 @@ QualType Sema::CheckTemplateIdType(TemplateName Name,
 
     // Only substitute for the innermost template argument list.
     MultiLevelTemplateArgumentList TemplateArgLists;
+    unsigned Depth = AliasTemplate->getTemplateParameters()->getDepth();
+    for (unsigned I = 0; I < Depth; ++I)
+      TemplateArgLists.addOuterTemplateArguments(0, 0);
     TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
 
     InstantiatingTemplate Inst(*this, TemplateLoc, Template);
diff --git a/test/SemaCXX/PR9902.cpp b/test/SemaCXX/PR9902.cpp
new file mode 100644
index 0000000000..ec76789b96
--- /dev/null
+++ b/test/SemaCXX/PR9902.cpp
@@ -0,0 +1,28 @@
+// RUN: %clang_cc1 -fsyntax-only -verify -std=c++0x %s
+
+template <class _Tp, class _Up, bool = false>
+struct __allocator_traits_rebind
+{
+};
+
+template <template <class, class...> class _Alloc, class _Tp, class ..._Args,
+class _Up>
+struct __allocator_traits_rebind<_Alloc<_Tp, _Args...>, _Up, false>
+{
+   typedef _Alloc<_Up, _Args...> type;
+};
+
+template <class Alloc>
+struct allocator_traits
+{
+   template <class T> using rebind_alloc = typename __allocator_traits_rebind<Alloc, T>::type;
+   template <class T> using rebind_traits = allocator_traits<rebind_alloc<T>>;
+};
+
+template <class T>
+struct allocator {};
+
+int main()
+{
+   allocator_traits<allocator<char>>::rebind_alloc<int> a;
+}
-- 
2.40.0