From df41f18936693f7c62e457eefb9fad5b2d2fe3cd Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Tue, 12 Oct 2010 19:40:14 +0000
Subject: [PATCH] Enter the context of the declared function template when
 performing deduction and the final substitution, but not while substituting
 the explicit template arguments.  Fixes rdar://problem/8537391

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@116332 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaTemplateDeduction.cpp |  8 ++++++--
 test/SemaTemplate/deduction.cpp    | 16 ++++++++++++++++
 2 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 6237610c09..ce3748b901 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -1218,8 +1218,6 @@ Sema::SubstituteExplicitTemplateArguments(
   if (Inst)
     return TDK_InstantiationDepth;
 
-  ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl());
-
   if (CheckTemplateArgumentList(FunctionTemplate,
                                 SourceLocation(),
                                 ExplicitTemplateArgs,
@@ -1238,6 +1236,12 @@ Sema::SubstituteExplicitTemplateArguments(
     = new (Context) TemplateArgumentList(Context, Builder, /*TakeArgs=*/true);
   Info.reset(ExplicitArgumentList);
 
+  // Template argument deduction and the final substitution should be
+  // done in the context of the templated declaration.  Explicit
+  // argument substitution, on the other hand, needs to happen in the
+  // calling context.
+  ContextRAII SavedContext(*this, FunctionTemplate->getTemplatedDecl());
+
   // Instantiate the types of each of the function parameters given the
   // explicitly-specified template arguments.
   for (FunctionDecl::param_iterator P = Function->param_begin(),
diff --git a/test/SemaTemplate/deduction.cpp b/test/SemaTemplate/deduction.cpp
index 9400a0aba9..cf98d6e0ac 100644
--- a/test/SemaTemplate/deduction.cpp
+++ b/test/SemaTemplate/deduction.cpp
@@ -134,3 +134,19 @@ namespace test2 {
     f(0, p);
   }
 }
+
+// rdar://problem/8537391
+namespace test3 {
+  struct Foo {
+    template <void F(char)> static inline void foo();
+  };
+
+  class Bar {
+    template<typename T> static inline void wobble(T ch);
+
+  public:
+    static void madness() {
+      Foo::foo<wobble<char> >();
+    }
+  };
+}
-- 
2.40.0