From d4598a2cc7576c06f69d3cf64d0e2c9783ddf529 Mon Sep 17 00:00:00 2001
From: Douglas Gregor <dgregor@apple.com>
Date: Wed, 28 Apr 2010 04:52:24 +0000
Subject: [PATCH] When instantiating a function template specialization
 following template argument deduction, use the lexical declaration context as
 the owner for friend function templates. Fixes 2 failures in Boost.Graph.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@102489 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaTemplateDeduction.cpp    |  6 ++++--
 test/SemaTemplate/friend-template.cpp | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/lib/Sema/SemaTemplateDeduction.cpp b/lib/Sema/SemaTemplateDeduction.cpp
index 7154d62d6c..0a2c5ae00e 100644
--- a/lib/Sema/SemaTemplateDeduction.cpp
+++ b/lib/Sema/SemaTemplateDeduction.cpp
@@ -1417,9 +1417,11 @@ Sema::FinishTemplateArgumentDeduction(FunctionTemplateDecl *FunctionTemplate,
 
   // Substitute the deduced template arguments into the function template
   // declaration to produce the function template specialization.
+  DeclContext *Owner = FunctionTemplate->getDeclContext();
+  if (FunctionTemplate->getFriendObjectKind())
+    Owner = FunctionTemplate->getLexicalDeclContext();
   Specialization = cast_or_null<FunctionDecl>(
-                      SubstDecl(FunctionTemplate->getTemplatedDecl(),
-                                FunctionTemplate->getDeclContext(),
+                      SubstDecl(FunctionTemplate->getTemplatedDecl(), Owner,
                          MultiLevelTemplateArgumentList(*DeducedArgumentList)));
   if (!Specialization)
     return TDK_SubstitutionFailure;
diff --git a/test/SemaTemplate/friend-template.cpp b/test/SemaTemplate/friend-template.cpp
index 6ee30aa777..4b60a3db05 100644
--- a/test/SemaTemplate/friend-template.cpp
+++ b/test/SemaTemplate/friend-template.cpp
@@ -127,3 +127,18 @@ namespace PR6022 {
   };
 }
 
+namespace FriendTemplateDefinition {
+  template<unsigned > struct int_c { };
+
+  template<typename T>
+  struct X {
+    template<unsigned N>
+    friend void f(X, int_c<N>) {
+      int value = N;
+    };
+  };
+
+  void test_X(X<int> x, int_c<5> i5) {
+    f(x, i5);
+  }
+}