Fix PCH bug with member templates of local classes in nontemplate functions.

As noted by Richard in the post:
http://lists.cs.uiuc.edu/pipermail/cfe-commits/Week-of-Mon-20130624/082605.html, the following code should not add an entry
into PendingLocalImplicitInstantiations, since local instantiations
should only occur within the context of other instantiations:

int foo(double y) {
   struct Lambda {
      template<class T> T operator()(T t) const { return t; };
   } lambda;
   return lambda(y);
}

Hence the attached code does the following:
  1) In MarkFunctionReferenced, check if ActiveInstantiations.size() 
      is non-zero before adding to PendingLocalImplicitInstantiations.
  2) In InstantiateFunctionDefinition, we swap out/in
      PendingLocalImplicitInstantiations so that only those 
      pending local instantiations that are added during the instantiation
      of the current function are instantiated recursively.

llvm-svn: 184903

1 files changed, 6 insertions, 0 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
index c947bcc9f2a..21a4cb12591 100644
--- a/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiateDecl.cpp
@@ -2918,6 +2918,10 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
   // while we're still within our own instantiation context.
   SmallVector<VTableUse, 16> SavedVTableUses;
   std::deque<PendingImplicitInstantiation> SavedPendingInstantiations;
+  std::deque<PendingImplicitInstantiation> 
+                              SavedPendingLocalImplicitInstantiations;
+  SavedPendingLocalImplicitInstantiations.swap(
+                                  PendingLocalImplicitInstantiations);
   if (Recursive) {
     VTableUses.swap(SavedVTableUses);
     PendingInstantiations.swap(SavedPendingInstantiations);
@@ -2998,6 +3002,8 @@ void Sema::InstantiateFunctionDefinition(SourceLocation PointOfInstantiation,
            "PendingInstantiations should be empty before it is discarded.");
     PendingInstantiations.swap(SavedPendingInstantiations);
   }
+  SavedPendingLocalImplicitInstantiations.swap(
+                            PendingLocalImplicitInstantiations);
 }
 
 /// \brief Instantiate the definition of the given variable from its