From 0b910bfbcda6b6c64afee2462018139ac9cef715 Mon Sep 17 00:00:00 2001
From: Richard Smith <richard-llvm@metafoo.co.uk>
Date: Tue, 24 May 2016 00:01:49 +0000
Subject: [PATCH] Properly track the found declaration (possibly a
 using-declaration) when handling an explicit member specialization.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@270514 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Sema/SemaTemplate.cpp | 9 +++++++--
 test/SemaCXX/friend.cpp   | 4 +++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index fd0dc6fca7..59e984dd93 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -7035,6 +7035,7 @@ Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
   assert(!isa<TemplateDecl>(Member) && "Only for non-template members");
 
   // Try to find the member we are instantiating.
+  NamedDecl *FoundInstantiation = nullptr;
   NamedDecl *Instantiation = nullptr;
   NamedDecl *InstantiatedFrom = nullptr;
   MemberSpecializationInfo *MSInfo = nullptr;
@@ -7050,6 +7051,7 @@ Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
         if (!hasExplicitCallingConv(Adjusted))
           Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
         if (Context.hasSameType(Adjusted, Method->getType())) {
+          FoundInstantiation = *I;
           Instantiation = Method;
           InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
           MSInfo = Method->getMemberSpecializationInfo();
@@ -7062,6 +7064,7 @@ Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
     if (Previous.isSingleResult() &&
         (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
       if (PrevVar->isStaticDataMember()) {
+        FoundInstantiation = Previous.getRepresentativeDecl();
         Instantiation = PrevVar;
         InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
         MSInfo = PrevVar->getMemberSpecializationInfo();
@@ -7070,6 +7073,7 @@ Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
     CXXRecordDecl *PrevRecord;
     if (Previous.isSingleResult() &&
         (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
+      FoundInstantiation = Previous.getRepresentativeDecl();
       Instantiation = PrevRecord;
       InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
       MSInfo = PrevRecord->getMemberSpecializationInfo();
@@ -7078,6 +7082,7 @@ Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
     EnumDecl *PrevEnum;
     if (Previous.isSingleResult() &&
         (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
+      FoundInstantiation = Previous.getRepresentativeDecl();
       Instantiation = PrevEnum;
       InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
       MSInfo = PrevEnum->getMemberSpecializationInfo();
@@ -7106,7 +7111,7 @@ Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
     }
 
     Previous.clear();
-    Previous.addDecl(Instantiation);
+    Previous.addDecl(FoundInstantiation);
     return false;
   }
 
@@ -7207,7 +7212,7 @@ Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
   // Save the caller the trouble of having to figure out which declaration
   // this specialization matches.
   Previous.clear();
-  Previous.addDecl(Instantiation);
+  Previous.addDecl(FoundInstantiation);
   return false;
 }
 
diff --git a/test/SemaCXX/friend.cpp b/test/SemaCXX/friend.cpp
index c90ce74616..4f27f4df6c 100644
--- a/test/SemaCXX/friend.cpp
+++ b/test/SemaCXX/friend.cpp
@@ -147,11 +147,13 @@ namespace test8 {
     }
     using ns2::f; // expected-note {{using declaration}}
   }
-  struct A { void f(); }; // expected-note {{target of using declaration}}
+  struct A { void f(); }; // expected-note 2{{target of using declaration}}
   struct B : public A { using A::f; }; // expected-note {{using declaration}}
+  template<typename T> struct C : A { using A::f; }; // expected-note {{using declaration}}
   struct X {
     template<class T> friend void ns1::f(T t); // expected-error {{cannot befriend target of using declaration}}
     friend void B::f(); // expected-error {{cannot befriend target of using declaration}}
+    friend void C<int>::f(); // expected-error {{cannot befriend target of using declaration}}
   };
 }
 
-- 
2.40.0