Improve our handling of local instantiation scopes in two related ways:

  - When substituting template arguments as part of template argument
    deduction, introduce a new local instantiation scope.
  - When substituting into a function prototype type, introduce a new
    "temporary" local instantiation scope that merges with its outer
    scope but also keeps track of any additions it makes, removing
    them when we exit that scope.

Fixes PR6700, where we were getting too much mixing of local
instantiation scopes due to template argument deduction that
substituted results into function types.

llvm-svn: 99509

1 files changed, 5 insertions, 2 deletions

diff --git a/clang/lib/Sema/SemaTemplateInstantiate.cpp b/clang/lib/Sema/SemaTemplateInstantiate.cpp
index ac1bf7219c5..89a660c79f9 100644
--- a/clang/lib/Sema/SemaTemplateInstantiate.cpp
+++ b/clang/lib/Sema/SemaTemplateInstantiate.cpp
@@ -873,8 +873,11 @@ TemplateInstantiator::TransformFunctionTypeParams(FunctionProtoTypeLoc TL,
                                   llvm::SmallVectorImpl<QualType> &PTypes,
                                llvm::SmallVectorImpl<ParmVarDecl*> &PVars) {
   // Create a local instantiation scope for the parameters.
-  Sema::LocalInstantiationScope
-    Scope(SemaRef, SemaRef.CurrentInstantiationScope != 0);
+  // FIXME: When we implement the C++0x late-specified return type, 
+  // we will need to move this scope out to the function type itself.
+  bool IsTemporaryScope = (SemaRef.CurrentInstantiationScope != 0);
+  Sema::LocalInstantiationScope Scope(SemaRef, IsTemporaryScope, 
+                                      IsTemporaryScope);
 
   if (TreeTransform<TemplateInstantiator>::
         TransformFunctionTypeParams(TL, PTypes, PVars))