PR13890: Warn on abstract final classes.

llvm-svn: 164359

4 files changed, 16 insertions, 0 deletions

diff --git a/clang/include/clang/Basic/DiagnosticGroups.td b/clang/include/clang/Basic/DiagnosticGroups.td
index 3f0093e4c3a..223c6c5e29a 100644
--- a/clang/include/clang/Basic/DiagnosticGroups.td
+++ b/clang/include/clang/Basic/DiagnosticGroups.td
@@ -49,6 +49,7 @@ def DefaultArgSpecialMember : DiagGroup<"default-arg-special-member">;
 def GNUDesignator : DiagGroup<"gnu-designator">;
 
 def DeleteNonVirtualDtor : DiagGroup<"delete-non-virtual-dtor">;
+def AbstractFinalClass : DiagGroup<"abstract-final-class">;
 
 def DeprecatedDeclarations : DiagGroup<"deprecated-declarations">;
 def DeprecatedWritableStr : DiagGroup<"deprecated-writable-strings">;
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 111455a1755..0556e8adc53 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -1350,6 +1350,8 @@ def err_function_marked_override_not_overriding : Error<
   "%0 marked 'override' but does not override any member functions">;
 def err_class_marked_final_used_as_base : Error<
   "base %0 is marked 'final'">;
+def warn_abstract_final_class : Warning<
+  "abstract class is marked 'final'">, InGroup<AbstractFinalClass>;
 
 // C++11 attributes
 def err_repeat_attribute : Error<"'%0' attribute cannot be repeated">;
diff --git a/clang/lib/Sema/SemaDeclCXX.cpp b/clang/lib/Sema/SemaDeclCXX.cpp
index e0c655f879f..3191e3fb489 100644
--- a/clang/lib/Sema/SemaDeclCXX.cpp
+++ b/clang/lib/Sema/SemaDeclCXX.cpp
@@ -3840,6 +3840,11 @@ void Sema::CheckCompletedCXXClass(CXXRecordDecl *Record) {
            diag::warn_non_virtual_dtor) << Context.getRecordType(Record);
   }
 
+  if (Record->isAbstract() && Record->hasAttr<FinalAttr>()) {
+    Diag(Record->getLocation(), diag::warn_abstract_final_class);
+    DiagnoseAbstractType(Record);
+  }
+
   // See if a method overloads virtual methods in a base
   /// class without overriding any.
   if (!Record->isDependentType()) {
diff --git a/clang/test/CXX/class/p2-0x.cpp b/clang/test/CXX/class/p2-0x.cpp
index dbb01e5ad52..5b39e0ada7e 100644
--- a/clang/test/CXX/class/p2-0x.cpp
+++ b/clang/test/CXX/class/p2-0x.cpp
@@ -26,3 +26,11 @@ struct C : A<int> { }; // expected-error {{base 'A' is marked 'final'}}
 
 }
 
+namespace Test4 {
+
+struct A final { virtual void func() = 0; }; // expected-warning {{abstract class is marked 'final'}} expected-note {{unimplemented pure virtual method 'func' in 'A'}}
+struct B { virtual void func() = 0; }; // expected-note {{unimplemented pure virtual method 'func' in 'C'}}
+
+struct C final : B { }; // expected-warning {{abstract class is marked 'final'}}
+
+}