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, 7 deletions

diff --git a/clang/lib/Sema/SemaTemplateDeduction.cpp b/clang/lib/Sema/SemaTemplateDeduction.cpp
index 326519d3a37..3a8ed508942 100644
--- a/clang/lib/Sema/SemaTemplateDeduction.cpp
+++ b/clang/lib/Sema/SemaTemplateDeduction.cpp
@@ -987,13 +987,7 @@ Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
       Decl *Param
         = const_cast<NamedDecl *>(
                                 Partial->getTemplateParameters()->getParam(I));
-      if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
-        Info.Param = TTP;
-      else if (NonTypeTemplateParmDecl *NTTP
-                 = dyn_cast<NonTypeTemplateParmDecl>(Param))
-        Info.Param = NTTP;
-      else
-        Info.Param = cast<TemplateTemplateParmDecl>(Param);
+      Info.Param = makeTemplateParameter(Param);
       return TDK_Incomplete;
     }
 
@@ -1010,6 +1004,7 @@ Sema::DeduceTemplateArguments(ClassTemplatePartialSpecializationDecl *Partial,
   // verify that the instantiated template arguments are both valid
   // and are equivalent to the template arguments originally provided
   // to the class template.
+  Sema::LocalInstantiationScope InstScope(*this);
   ClassTemplateDecl *ClassTemplate = Partial->getSpecializedTemplate();
   const TemplateArgumentLoc *PartialTemplateArgs
     = Partial->getTemplateArgsAsWritten();
@@ -1458,6 +1453,7 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
 
   // The types of the parameters from which we will perform template argument
   // deduction.
+  Sema::LocalInstantiationScope InstScope(*this);
   TemplateParameterList *TemplateParams
     = FunctionTemplate->getTemplateParameters();
   llvm::SmallVector<TemplateArgument, 4> Deduced;
@@ -1612,6 +1608,7 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
   QualType FunctionType = Function->getType();
 
   // Substitute any explicit template arguments.
+  Sema::LocalInstantiationScope InstScope(*this);
   llvm::SmallVector<TemplateArgument, 4> Deduced;
   llvm::SmallVector<QualType, 4> ParamTypes;
   if (ExplicitTemplateArgs) {
@@ -1739,6 +1736,7 @@ Sema::DeduceTemplateArguments(FunctionTemplateDecl *FunctionTemplate,
   // modulo the various allowed differences.
 
   // Finish template argument deduction.
+  Sema::LocalInstantiationScope InstScope(*this);
   FunctionDecl *Spec = 0;
   TemplateDeductionResult Result
     = FinishTemplateArgumentDeduction(FunctionTemplate, Deduced, Spec, Info);