Implement support for non-type template parameter packs whose type is

a pack expansion, e.g., the parameter pack Values in:

  template<typename ...Types>
  struct Outer {
    template<Types ...Values>
    struct Inner;
  };

This new implementation approach introduces the notion of an
"expanded" non-type template parameter pack, for which we have already
expanded the types of the parameter pack (to, say, "int*, float*",
for Outer<int*, float*>) but have not yet expanded the values. Aside
from creating these expanded non-type template parameter packs, this
patch updates template argument checking and non-type template
parameter pack instantiation to make use of the appropriate types in
the parameter pack.



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@123845 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 11 insertions, 1 deletions

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 156b8496c4..9e2e8763f8 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -133,11 +133,21 @@ getLVForTemplateParameterList(const TemplateParameterList *Params) {
   for (TemplateParameterList::const_iterator P = Params->begin(),
                                           PEnd = Params->end();
        P != PEnd; ++P) {
-    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P))
+    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(*P)) {
+      if (NTTP->isExpandedParameterPack()) {
+        for (unsigned I = 0, N = NTTP->getNumExpansionTypes(); I != N; ++I) {
+          QualType T = NTTP->getExpansionType(I);
+          if (!T->isDependentType())
+            LV = merge(LV, T->getLinkageAndVisibility());
+        }
+        continue;
+      }
+      
       if (!NTTP->getType()->isDependentType()) {
         LV = merge(LV, NTTP->getType()->getLinkageAndVisibility());
         continue;
       }
+    }
 
     if (TemplateTemplateParmDecl *TTP
                                    = dyn_cast<TemplateTemplateParmDecl>(*P)) {