Grab-bag of bit-field fixes:

  - References to ObjC bit-field ivars are bit-field lvalues;
    fixes rdar://13794269, which got me started down this.
  - Introduce Expr::refersToBitField, switch a couple users to
    it where semantically important, and comment the difference
    between this and the existing API.
  - Discourage Expr::getBitField by making it a bit longer and
    less general-sounding.
  - Lock down on const_casts of bit-field gl-values until we
    hear back from the committee as to whether they're allowed.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@181252 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 10 insertions, 5 deletions

diff --git a/lib/Sema/SemaInit.cpp b/lib/Sema/SemaInit.cpp
index de93adb6be..9e8936e17b 100644
--- a/lib/Sema/SemaInit.cpp
+++ b/lib/Sema/SemaInit.cpp
@@ -3440,7 +3440,7 @@ convertQualifiersAndValueKindIfNecessary(Sema &S,
                                          Qualifiers T1Quals,
                                          Qualifiers T2Quals,
                                          bool IsLValueRef) {
-  bool IsNonAddressableType = Initializer->getBitField() ||
+  bool IsNonAddressableType = Initializer->refersToBitField() ||
                               Initializer->refersToVectorElement();
 
   if (IsNonAddressableType) {
@@ -5225,13 +5225,18 @@ InitializationSequence::Perform(Sema &S,
     }
 
     case SK_BindReference:
-      if (FieldDecl *BitField = CurInit.get()->getBitField()) {
-        // References cannot bind to bit fields (C++ [dcl.init.ref]p5).
+      // References cannot bind to bit-fields (C++ [dcl.init.ref]p5).
+      if (CurInit.get()->refersToBitField()) {
+        // We don't necessarily have an unambiguous source bit-field.
+        FieldDecl *BitField = CurInit.get()->getSourceBitField();
         S.Diag(Kind.getLocation(), diag::err_reference_bind_to_bitfield)
           << Entity.getType().isVolatileQualified()
-          << BitField->getDeclName()
+          << (BitField ? BitField->getDeclName() : DeclarationName())
+          << (BitField != NULL)
           << CurInit.get()->getSourceRange();
-        S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
+        if (BitField)
+          S.Diag(BitField->getLocation(), diag::note_bitfield_decl);
+
         return ExprError();
       }