[modules] Track all default template arguments for a given parameter across

modules, and allow use of a default template argument if any of the parameters
providing it is visible.

llvm-svn: 239485

1 files changed, 5 insertions, 12 deletions

diff --git a/clang/lib/Sema/SemaTemplate.cpp b/clang/lib/Sema/SemaTemplate.cpp
index 941672c6e39..6bb4be1d18b 100644
--- a/clang/lib/Sema/SemaTemplate.cpp
+++ b/clang/lib/Sema/SemaTemplate.cpp
@@ -1310,15 +1310,11 @@ bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
       // Merge default arguments for template type parameters.
       TemplateTypeParmDecl *OldTypeParm
           = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
-      // FIXME: There might be a visible declaration of this template parameter.
-      if (OldTypeParm && !LookupResult::isVisible(*this, OldTypeParm))
-        OldTypeParm = nullptr;
-
       if (NewTypeParm->isParameterPack()) {
         assert(!NewTypeParm->hasDefaultArgument() &&
                "Parameter packs can't have a default argument!");
         SawParameterPack = true;
-      } else if (OldTypeParm && OldTypeParm->hasDefaultArgument() &&
+      } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
                  NewTypeParm->hasDefaultArgument()) {
         OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
         NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
@@ -1357,14 +1353,12 @@ bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
       // Merge default arguments for non-type template parameters
       NonTypeTemplateParmDecl *OldNonTypeParm
         = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
-      if (OldNonTypeParm && !LookupResult::isVisible(*this, OldNonTypeParm))
-        OldNonTypeParm = nullptr;
       if (NewNonTypeParm->isParameterPack()) {
         assert(!NewNonTypeParm->hasDefaultArgument() &&
                "Parameter packs can't have a default argument!");
         if (!NewNonTypeParm->isPackExpansion())
           SawParameterPack = true;
-      } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument() &&
+      } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
                  NewNonTypeParm->hasDefaultArgument()) {
         OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
         NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
@@ -1401,15 +1395,14 @@ bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
       // Merge default arguments for template template parameters
       TemplateTemplateParmDecl *OldTemplateParm
         = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
-      if (OldTemplateParm && !LookupResult::isVisible(*this, OldTemplateParm))
-        OldTemplateParm = nullptr;
       if (NewTemplateParm->isParameterPack()) {
         assert(!NewTemplateParm->hasDefaultArgument() &&
                "Parameter packs can't have a default argument!");
         if (!NewTemplateParm->isPackExpansion())
           SawParameterPack = true;
-      } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument() &&
-          NewTemplateParm->hasDefaultArgument()) {
+      } else if (OldTemplateParm &&
+                 hasVisibleDefaultArgument(OldTemplateParm) &&
+                 NewTemplateParm->hasDefaultArgument()) {
         OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
         NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
         SawDefaultArgument = true;