Vendor import of clang trunk r242221:vendor/clang/clang-trunk-r242221

https://llvm.org/svn/llvm-project/cfe/trunk@242221

1 files changed, 32 insertions, 7 deletions

diff --git a/lib/Sema/SemaTemplate.cpp b/lib/Sema/SemaTemplate.cpp
index f4740a5cd855..035c37cfe6e9 100644
--- a/lib/Sema/SemaTemplate.cpp
+++ b/lib/Sema/SemaTemplate.cpp
@@ -893,6 +893,16 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
     LookupQualifiedName(Previous, SemanticContext);
   } else {
     SemanticContext = CurContext;
+
+    // C++14 [class.mem]p14:
+    //   If T is the name of a class, then each of the following shall have a
+    //   name different from T:
+    //    -- every member template of class T
+    if (TUK != TUK_Friend &&
+        DiagnoseClassNameShadow(SemanticContext,
+                                DeclarationNameInfo(Name, NameLoc)))
+      return true;
+
     LookupName(Previous, S);
   }
 
@@ -947,8 +957,7 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
 
         // Check that the chosen semantic context doesn't already contain a
         // declaration of this name as a non-tag type.
-        LookupResult Previous(*this, Name, NameLoc, LookupOrdinaryName,
-                              ForRedeclaration);
+        Previous.clear(LookupOrdinaryName);
         DeclContext *LookupContext = SemanticContext;
         while (LookupContext->isTransparentContext())
           LookupContext = LookupContext->getLookupParent();
@@ -962,9 +971,25 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
       }
     }
   } else if (PrevDecl &&
-             !isDeclInScope(PrevDecl, SemanticContext, S, SS.isValid()))
+             !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
+                            S, SS.isValid()))
     PrevDecl = PrevClassTemplate = nullptr;
 
+  if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
+          PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
+    if (SS.isEmpty() &&
+        !(PrevClassTemplate &&
+          PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
+              SemanticContext->getRedeclContext()))) {
+      Diag(KWLoc, diag::err_using_decl_conflict_reverse);
+      Diag(Shadow->getTargetDecl()->getLocation(),
+           diag::note_using_decl_target);
+      Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
+      // Recover by ignoring the old declaration.
+      PrevDecl = PrevClassTemplate = nullptr;
+    }
+  }
+
   if (PrevClassTemplate) {
     // Ensure that the template parameter lists are compatible. Skip this check
     // for a friend in a dependent context: the template parameter list itself
@@ -983,7 +1008,7 @@ Sema::CheckClassTemplate(Scope *S, unsigned TagSpec, TagUseKind TUK,
     //   template declaration (7.1.5.3).
     RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
     if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
-                                      TUK == TUK_Definition,  KWLoc, *Name)) {
+                                      TUK == TUK_Definition,  KWLoc, Name)) {
       Diag(KWLoc, diag::err_use_with_wrong_tag)
         << Name
         << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
@@ -2285,7 +2310,7 @@ TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
     assert(Id && "templated class must have an identifier");
     
     if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
-                                      TagLoc, *Id)) {
+                                      TagLoc, Id)) {
       Diag(TagLoc, diag::err_use_with_wrong_tag)
         << Result
         << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
@@ -6174,7 +6199,7 @@ Sema::ActOnClassTemplateSpecialization(Scope *S, unsigned TagSpec,
   assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!");
   if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
                                     Kind, TUK == TUK_Definition, KWLoc,
-                                    *ClassTemplate->getIdentifier())) {
+                                    ClassTemplate->getIdentifier())) {
     Diag(KWLoc, diag::err_use_with_wrong_tag)
       << ClassTemplate
       << FixItHint::CreateReplacement(KWLoc,
@@ -7210,7 +7235,7 @@ Sema::ActOnExplicitInstantiation(Scope *S,
 
   if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
                                     Kind, /*isDefinition*/false, KWLoc,
-                                    *ClassTemplate->getIdentifier())) {
+                                    ClassTemplate->getIdentifier())) {
     Diag(KWLoc, diag::err_use_with_wrong_tag)
       << ClassTemplate
       << FixItHint::CreateReplacement(KWLoc,