Implement DR257 / fix PR16659:

  A constructor for an abstract class does not call constructors for virtual
  base classes, so it is not an error if no initializer is present for the
  virtual base and the virtual base cannot be default initialized.

Also provide a (disabled by default, for now) warning for the case where a
virtual base class's initializer is ignored in an abstract class's constructor,
and address a defect in DR257 where it was not carried through to C++11's rules
for implicit deletion of special member functions.

Based on a patch by Maurice Bos.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@186803 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 8 insertions, 1 deletions

diff --git a/include/clang/Basic/Diagnostic.h b/include/clang/Basic/Diagnostic.h
index 1354120ea5..0fcfdf7cb3 100644
--- a/include/clang/Basic/Diagnostic.h
+++ b/include/clang/Basic/Diagnostic.h
@@ -490,7 +490,14 @@ public:
       FatalErrorOccurred = true;
     LastDiagLevel = DiagnosticIDs::Ignored;
   }
-  
+
+  /// \brief Determine whether the previous diagnostic was ignored. This can
+  /// be used by clients that want to determine whether notes attached to a
+  /// diagnostic will be suppressed.
+  bool isLastDiagnosticIgnored() const {
+    return LastDiagLevel == DiagnosticIDs::Ignored;
+  }
+
   /// \brief Controls whether otherwise-unmapped extension diagnostics are
   /// mapped onto ignore/warning/error. 
   ///