Teach template template argument pack expansions to keep track of the

number of expansions, when we know it, and propagate that information
through Sema.

llvm-svn: 123493

4 files changed, 16 insertions, 5 deletions

diff --git a/clang/lib/AST/ASTContext.cpp b/clang/lib/AST/ASTContext.cpp
index a98e0636d49..e1e6fd08aa2 100644
--- a/clang/lib/AST/ASTContext.cpp
+++ b/clang/lib/AST/ASTContext.cpp
@@ -2768,7 +2768,7 @@ ASTContext::getCanonicalTemplateArgument(const TemplateArgument &Arg) const {
     case TemplateArgument::TemplateExpansion:
       return TemplateArgument(getCanonicalTemplateName(
                                          Arg.getAsTemplateOrTemplatePattern()),
-                              true);
+                              Arg.getNumTemplateExpansions());
 
     case TemplateArgument::Integral:
       return TemplateArgument(*Arg.getAsIntegral(),
diff --git a/clang/lib/AST/ASTImporter.cpp b/clang/lib/AST/ASTImporter.cpp
index 7989b9f278b..f9fe18f5dfb 100644
--- a/clang/lib/AST/ASTImporter.cpp
+++ b/clang/lib/AST/ASTImporter.cpp
@@ -1823,7 +1823,7 @@ ASTNodeImporter::ImportTemplateArgument(const TemplateArgument &From) {
     if (ToTemplate.isNull())
       return TemplateArgument();
     
-    return TemplateArgument(ToTemplate, true);
+    return TemplateArgument(ToTemplate, From.getNumTemplateExpansions());
   }
 
   case TemplateArgument::Expression:
diff --git a/clang/lib/AST/DeclTemplate.cpp b/clang/lib/AST/DeclTemplate.cpp
index e7902e996a9..b6716b34bdf 100644
--- a/clang/lib/AST/DeclTemplate.cpp
+++ b/clang/lib/AST/DeclTemplate.cpp
@@ -337,7 +337,10 @@ ClassTemplateDecl::getInjectedClassNameSpecialization() {
       Arg = TemplateArgument(E);
     } else {
       TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(*Param);
-      Arg = TemplateArgument(TemplateName(TTP), TTP->isParameterPack());
+      if (TTP->isParameterPack())
+        Arg = TemplateArgument(TemplateName(TTP), llvm::Optional<unsigned>());
+      else
+        Arg = TemplateArgument(TemplateName(TTP));
     }
     
     if ((*Param)->isTemplateParameterPack())
diff --git a/clang/lib/AST/TemplateBase.cpp b/clang/lib/AST/TemplateBase.cpp
index 26c0c089718..f3def3eff2c 100644
--- a/clang/lib/AST/TemplateBase.cpp
+++ b/clang/lib/AST/TemplateBase.cpp
@@ -135,6 +135,14 @@ bool TemplateArgument::containsUnexpandedParameterPack() const {
   return false;
 }
 
+llvm::Optional<unsigned> TemplateArgument::getNumTemplateExpansions() const {
+  assert(Kind == TemplateExpansion);
+  if (TemplateArg.NumExpansions)
+    return TemplateArg.NumExpansions - 1;
+  
+  return llvm::Optional<unsigned>();
+}
+
 void TemplateArgument::Profile(llvm::FoldingSetNodeID &ID,
                                const ASTContext &Context) const {
   ID.AddInteger(Kind);
@@ -223,7 +231,7 @@ TemplateArgument TemplateArgument::getPackExpansionPattern() const {
     return cast<PackExpansionExpr>(getAsExpr())->getPattern();
     
   case TemplateExpansion:
-    return TemplateArgument(getAsTemplateOrTemplatePattern(), false);
+    return TemplateArgument(getAsTemplateOrTemplatePattern());
     
   case Declaration:
   case Integral:
@@ -389,8 +397,8 @@ TemplateArgumentLoc::getPackExpansionPattern(SourceLocation &Ellipsis,
   }
 
   case TemplateArgument::TemplateExpansion:
-    // FIXME: Variadic templates num expansions
     Ellipsis = getTemplateEllipsisLoc();
+    NumExpansions = Argument.getNumTemplateExpansions();
     return TemplateArgumentLoc(Argument.getPackExpansionPattern(),
                                getTemplateQualifierRange(),
                                getTemplateNameLoc());