3 files changed, 35 insertions, 18 deletions

diff --git a/lib/Sema/Sema.cpp b/lib/Sema/Sema.cpp
index dc1270243d..c954c64e7d 100644
--- a/lib/Sema/Sema.cpp
+++ b/lib/Sema/Sema.cpp
@@ -373,22 +373,30 @@ void Sema::ActOnEndOfTranslationUnit() {
       }
     }
 
-    // If DefinedUsedVTables ends up marking any virtual member functions it
-    // might lead to more pending template instantiations, which we then need
-    // to instantiate.
-    DefineUsedVTables();
-
-    // C++: Perform implicit template instantiations.
-    //
-    // FIXME: When we perform these implicit instantiations, we do not
-    // carefully keep track of the point of instantiation (C++ [temp.point]).
-    // This means that name lookup that occurs within the template
-    // instantiation will always happen at the end of the translation unit,
-    // so it will find some names that should not be found. Although this is
-    // common behavior for C++ compilers, it is technically wrong. In the
-    // future, we either need to be able to filter the results of name lookup
-    // or we need to perform template instantiations earlier.
-    PerformPendingInstantiations();
+    bool SomethingChanged;
+    do {
+      SomethingChanged = false;
+      
+      // If DefinedUsedVTables ends up marking any virtual member functions it
+      // might lead to more pending template instantiations, which we then need
+      // to instantiate.
+      if (DefineUsedVTables())
+        SomethingChanged = true;
+
+      // C++: Perform implicit template instantiations.
+      //
+      // FIXME: When we perform these implicit instantiations, we do not
+      // carefully keep track of the point of instantiation (C++ [temp.point]).
+      // This means that name lookup that occurs within the template
+      // instantiation will always happen at the end of the translation unit,
+      // so it will find some names that should not be found. Although this is
+      // common behavior for C++ compilers, it is technically wrong. In the
+      // future, we either need to be able to filter the results of name lookup
+      // or we need to perform template instantiations earlier.
+      if (PerformPendingInstantiations())
+        SomethingChanged = true;
+      
+    } while (SomethingChanged);
   }
   
   // Remove file scoped decls that turned out to be used.
diff --git a/lib/Sema/SemaDeclCXX.cpp b/lib/Sema/SemaDeclCXX.cpp
index 5f3f600c8c..3a87cfd966 100644
--- a/lib/Sema/SemaDeclCXX.cpp
+++ b/lib/Sema/SemaDeclCXX.cpp
@@ -7751,6 +7751,7 @@ bool Sema::DefineUsedVTables() {
   // the members of a class as "used", so we check the size each
   // time through the loop and prefer indices (with are stable) to
   // iterators (which are not).
+  bool DefinedAnything = false;
   for (unsigned I = 0; I != VTableUses.size(); ++I) {
     CXXRecordDecl *Class = VTableUses[I].first->getDefinition();
     if (!Class)
@@ -7803,6 +7804,7 @@ bool Sema::DefineUsedVTables() {
     // Mark all of the virtual members of this class as referenced, so
     // that we can build a vtable. Then, tell the AST consumer that a
     // vtable for this class is required.
+    DefinedAnything = true;
     MarkVirtualMembersReferenced(Loc, Class);
     CXXRecordDecl *Canonical = cast<CXXRecordDecl>(Class->getCanonicalDecl());
     Consumer.HandleVTable(Class, VTablesUsed[Canonical]);
@@ -7816,7 +7818,7 @@ bool Sema::DefineUsedVTables() {
   }
   VTableUses.clear();
 
-  return true;
+  return DefinedAnything;
 }
 
 void Sema::MarkVirtualMembersReferenced(SourceLocation Loc,
diff --git a/lib/Sema/SemaTemplateInstantiateDecl.cpp b/lib/Sema/SemaTemplateInstantiateDecl.cpp
index 588501f50e..c972c6602e 100644
--- a/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -3109,7 +3109,10 @@ NamedDecl *Sema::FindInstantiatedDecl(SourceLocation Loc, NamedDecl *D,
 
 /// \brief Performs template instantiation for all implicit template
 /// instantiations we have seen until this point.
-void Sema::PerformPendingInstantiations(bool LocalOnly) {
+///
+/// \returns true if anything was instantiated.
+bool Sema::PerformPendingInstantiations(bool LocalOnly) {
+  bool InstantiatedAnything = false;
   while (!PendingLocalImplicitInstantiations.empty() ||
          (!LocalOnly && !PendingInstantiations.empty())) {
     PendingImplicitInstantiation Inst;
@@ -3130,6 +3133,7 @@ void Sema::PerformPendingInstantiations(bool LocalOnly) {
                                 TSK_ExplicitInstantiationDefinition;
       InstantiateFunctionDefinition(/*FIXME:*/Inst.second, Function, true,
                                     DefinitionRequired);
+      InstantiatedAnything = true;
       continue;
     }
 
@@ -3166,7 +3170,10 @@ void Sema::PerformPendingInstantiations(bool LocalOnly) {
                               TSK_ExplicitInstantiationDefinition;
     InstantiateStaticDataMemberDefinition(/*FIXME:*/Inst.second, Var, true,
                                           DefinitionRequired);
+    InstantiatedAnything = true;
   }
+  
+  return InstantiatedAnything;
 }
 
 void Sema::PerformDependentDiagnostics(const DeclContext *Pattern,