fix dual aspect of PR8007,

namely when the friend function prototype is already used
at the point of the template definition that is supposed
to inject the friend function. Testcase verifies four
scenarios.
I would like receive some code review for this.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112524 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 37 insertions, 11 deletions

diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index e2dfb29c1b..6653e2e8ca 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -1166,7 +1166,9 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
 
     PrincipalDecl->setObjectOfFriendDecl(PrevDecl != 0);
     DC->makeDeclVisibleInContext(PrincipalDecl, /*Recoverable=*/ false);
-    
+
+		bool queuedInstantiation = false;
+
     if (!SemaRef.getLangOptions().CPlusPlus0x &&
         D->isThisDeclarationADefinition()) {
       // Check for a function body.
@@ -1185,7 +1187,22 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
                 R != REnd; ++R) {
         if (*R == Function)
           continue;
-        if (R->getFriendObjectKind() != Decl::FOK_None) {
+        switch (R->getFriendObjectKind()) {
+        case Decl::FOK_None:
+          if (!queuedInstantiation && R->isUsed(false)) {
+            if (MemberSpecializationInfo *MSInfo
+                = Function->getMemberSpecializationInfo()) {
+              if (MSInfo->getPointOfInstantiation().isInvalid()) {
+                SourceLocation Loc = R->getLocation(); // FIXME
+                MSInfo->setPointOfInstantiation(Loc);
+                SemaRef.PendingLocalImplicitInstantiations.push_back(
+                                                 std::make_pair(Function, Loc));
+                queuedInstantiation = true;
+              }
+            }
+          }
+          break;
+        default:
           if (const FunctionDecl *RPattern
               = R->getTemplateInstantiationPattern())
             if (RPattern->hasBody(RPattern)) {
@@ -1198,7 +1215,6 @@ Decl *TemplateDeclInstantiator::VisitFunctionDecl(FunctionDecl *D,
         }
       }
     }
-      
   }
 
   if (Function->isOverloadedOperator() && !DC->isRecord() &&
diff --git a/test/SemaTemplate/inject-templated-friend-post.cpp b/test/SemaTemplate/inject-templated-friend-post.cpp
index bbb80d15fc..aae7c01681 100644
--- a/test/SemaTemplate/inject-templated-friend-post.cpp
+++ b/test/SemaTemplate/inject-templated-friend-post.cpp
@@ -1,8 +1,9 @@
 // RUN: %clang %s -S -emit-llvm -o - | grep -e "define linkonce_odr.*_ZlsR11std_ostreamRK8StreamerI3FooE"
+// RUN: %clang %s -S -emit-llvm -o - -DPROTOTYPE | grep -e "define linkonce_odr.*_ZlsR11std_ostreamRK8StreamerI3FooE"
 // RUN: %clang -cc1 %s -DREDEFINE -verify
+// RUN: %clang -cc1 %s -DPROTOTYPE -DREDEFINE -verify
 // PR8007: friend function not instantiated, reordered version.
 // Corresponds to http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38392
-// XFAIL: *
 
 struct std_ostream
 {
@@ -17,6 +18,7 @@ struct Streamer;
 typedef struct Foo {} Foo;
 
 std_ostream& operator << (std_ostream&, const Streamer<Foo>&);
+
 void test(const Streamer<Foo>& foo)
 {
     cout << foo;
@@ -38,6 +40,21 @@ struct Streamer
     void operator () (std_ostream&) const;
 };
 
+#ifdef PROTOTYPE
+std_ostream& operator << (std_ostream&, const Streamer<Foo>&);
+#endif
+
+#ifdef INSTANTIATE
+template struct Streamer<Foo>;
+#endif
+
+#ifdef REDEFINE
+std_ostream& operator << (std_ostream& o, const Streamer<Foo>&) // expected-note{{is here}}
+{
+  return o;
+}
+#endif
+
 template <>
 void Streamer<Foo>::operator () (std_ostream& o) const // expected-note{{requested here}}
 {
@@ -49,10 +66,3 @@ int main(void)
     test(foo);
 }
 
-#ifdef REDEFINE
-std_ostream& operator << (std_ostream& o, const Streamer<Foo>&) // expected-note{{is here}}
-{
-  // Sema should flag this as a redefinition
-  return o;
-}
-#endif