Remember if a type has its visibility set explicitly or implicitly.

With that, centralize the way we merge visibility, always preferring explicit over
implicit and then picking the most restrictive one.
Fixes pr10113 and pr11690.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148163 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 26 insertions, 32 deletions

diff --git a/lib/AST/Decl.cpp b/lib/AST/Decl.cpp
index 738414e021..9132b0a190 100644
--- a/lib/AST/Decl.cpp
+++ b/lib/AST/Decl.cpp
@@ -67,17 +67,6 @@ static llvm::Optional<Visibility> getVisibilityOf(const Decl *D) {
 }
 
 typedef NamedDecl::LinkageInfo LinkageInfo;
-typedef std::pair<Linkage,Visibility> LVPair;
-
-static LVPair merge(LVPair L, LVPair R) {
-  return LVPair(minLinkage(L.first, R.first),
-                minVisibility(L.second, R.second));
-}
-
-static LVPair merge(LVPair L, LinkageInfo R) {
-  return LVPair(minLinkage(L.first, R.linkage()),
-                minVisibility(L.second, R.visibility()));
-}
 
 namespace {
 /// Flags controlling the computation of linkage and visibility.
@@ -113,11 +102,16 @@ struct LVFlags {
 }; 
 } // end anonymous namespace
 
+static LinkageInfo getLVForType(QualType T) {
+  std::pair<Linkage,Visibility> P = T->getLinkageAndVisibility();
+  return LinkageInfo(P.first, P.second, T->isVisibilityExplicit());
+}
+
 /// \brief Get the most restrictive linkage for the types in the given
 /// template parameter list.
-static LVPair
+static LinkageInfo
 getLVForTemplateParameterList(const TemplateParameterList *Params) {
-  LVPair LV(ExternalLinkage, DefaultVisibility);
+  LinkageInfo LV(ExternalLinkage, DefaultVisibility, false);
   for (TemplateParameterList::const_iterator P = Params->begin(),
                                           PEnd = Params->end();
        P != PEnd; ++P) {
@@ -126,20 +120,20 @@ getLVForTemplateParameterList(const TemplateParameterList *Params) {
         for (unsigned I = 0, N = NTTP->getNumExpansionTypes(); I != N; ++I) {
           QualType T = NTTP->getExpansionType(I);
           if (!T->isDependentType())
-            LV = merge(LV, T->getLinkageAndVisibility());
+            LV.merge(getLVForType(T));
         }
         continue;
       }
 
       if (!NTTP->getType()->isDependentType()) {
-        LV = merge(LV, NTTP->getType()->getLinkageAndVisibility());
+        LV.merge(getLVForType(NTTP->getType()));
         continue;
       }
     }
 
     if (TemplateTemplateParmDecl *TTP
                                    = dyn_cast<TemplateTemplateParmDecl>(*P)) {
-      LV = merge(LV, getLVForTemplateParameterList(TTP->getTemplateParameters()));
+      LV.merge(getLVForTemplateParameterList(TTP->getTemplateParameters()));
     }
   }
 
@@ -151,10 +145,10 @@ static LinkageInfo getLVForDecl(const NamedDecl *D, LVFlags F);
 
 /// \brief Get the most restrictive linkage for the types and
 /// declarations in the given template argument list.
-static LVPair getLVForTemplateArgumentList(const TemplateArgument *Args,
-                                           unsigned NumArgs,
-                                           LVFlags &F) {
-  LVPair LV(ExternalLinkage, DefaultVisibility);
+static LinkageInfo getLVForTemplateArgumentList(const TemplateArgument *Args,
+                                                unsigned NumArgs,
+                                                LVFlags &F) {
+  LinkageInfo LV(ExternalLinkage, DefaultVisibility, false);
 
   for (unsigned I = 0; I != NumArgs; ++I) {
     switch (Args[I].getKind()) {
@@ -164,7 +158,7 @@ static LVPair getLVForTemplateArgumentList(const TemplateArgument *Args,
       break;
 
     case TemplateArgument::Type:
-      LV = merge(LV, Args[I].getAsType()->getLinkageAndVisibility());
+      LV.merge(getLVForType(Args[I].getAsType()));
       break;
 
     case TemplateArgument::Declaration:
@@ -180,13 +174,13 @@ static LVPair getLVForTemplateArgumentList(const TemplateArgument *Args,
     case TemplateArgument::TemplateExpansion:
       if (TemplateDecl *Template
                 = Args[I].getAsTemplateOrTemplatePattern().getAsTemplateDecl())
-        LV = merge(LV, getLVForDecl(Template, F));
+        LV.merge(getLVForDecl(Template, F));
       break;
 
     case TemplateArgument::Pack:
-      LV = merge(LV, getLVForTemplateArgumentList(Args[I].pack_begin(),
-                                                  Args[I].pack_size(),
-                                                  F));
+      LV.merge(getLVForTemplateArgumentList(Args[I].pack_begin(),
+                                            Args[I].pack_size(),
+                                            F));
       break;
     }
   }
@@ -194,7 +188,7 @@ static LVPair getLVForTemplateArgumentList(const TemplateArgument *Args,
   return LV;
 }
 
-static LVPair
+static LinkageInfo
 getLVForTemplateArgumentList(const TemplateArgumentList &TArgs,
                              LVFlags &F) {
   return getLVForTemplateArgumentList(TArgs.data(), TArgs.size(), F);
@@ -337,11 +331,11 @@ static LinkageInfo getLVForNamespaceScopeDecl(const NamedDecl *D, LVFlags F) {
     // Note that we don't want to make the variable non-external
     // because of this, but unique-external linkage suits us.
     if (Context.getLangOptions().CPlusPlus && !Var->isExternC()) {
-      LVPair TypeLV = Var->getType()->getLinkageAndVisibility();
-      if (TypeLV.first != ExternalLinkage)
+      LinkageInfo TypeLV = getLVForType(Var->getType());
+      if (TypeLV.linkage() != ExternalLinkage)
         return LinkageInfo::uniqueExternal();
       if (!LV.visibilityExplicit())
-        LV.mergeVisibility(TypeLV.second);
+        LV.mergeVisibility(TypeLV.visibility(), TypeLV.visibilityExplicit());
     }
 
     if (Var->getStorageClass() == SC_PrivateExtern)
@@ -599,11 +593,11 @@ static LinkageInfo getLVForClassMember(const NamedDecl *D, LVFlags F) {
   } else if (const VarDecl *VD = dyn_cast<VarDecl>(D)) {
     // Modify the variable's linkage by its type, but ignore the
     // type's visibility unless it's a definition.
-    LVPair TypeLV = VD->getType()->getLinkageAndVisibility();
-    if (TypeLV.first != ExternalLinkage)
+    LinkageInfo TypeLV = getLVForType(VD->getType());
+    if (TypeLV.linkage() != ExternalLinkage)
       LV.mergeLinkage(UniqueExternalLinkage);
     if (!LV.visibilityExplicit())
-      LV.mergeVisibility(TypeLV.second);
+      LV.mergeVisibility(TypeLV.visibility(), TypeLV.visibilityExplicit());
   }
 
   F.ConsiderGlobalVisibility &= !LV.visibilityExplicit();