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, 8 insertions, 3 deletions

diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index cf7ddbce93..9538ddf941 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -3149,7 +3149,7 @@ bool Expr::isObjCSelfExpr() const {
   return M->getSelfDecl() == Param;
 }
 
-FieldDecl *Expr::getBitField() {
+FieldDecl *Expr::getSourceBitField() {
   Expr *E = this->IgnoreParens();
 
   while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(E)) {
@@ -3165,6 +3165,11 @@ FieldDecl *Expr::getBitField() {
       if (Field->isBitField())
         return Field;
 
+  if (ObjCIvarRefExpr *IvarRef = dyn_cast<ObjCIvarRefExpr>(E))
+    if (FieldDecl *Ivar = dyn_cast<FieldDecl>(IvarRef->getDecl()))
+      if (Ivar->isBitField())
+        return Ivar;
+
   if (DeclRefExpr *DeclRef = dyn_cast<DeclRefExpr>(E))
     if (FieldDecl *Field = dyn_cast<FieldDecl>(DeclRef->getDecl()))
       if (Field->isBitField())
@@ -3172,10 +3177,10 @@ FieldDecl *Expr::getBitField() {
 
   if (BinaryOperator *BinOp = dyn_cast<BinaryOperator>(E)) {
     if (BinOp->isAssignmentOp() && BinOp->getLHS())
-      return BinOp->getLHS()->getBitField();
+      return BinOp->getLHS()->getSourceBitField();
 
     if (BinOp->getOpcode() == BO_Comma && BinOp->getRHS())
-      return BinOp->getRHS()->getBitField();
+      return BinOp->getRHS()->getSourceBitField();
   }
 
   return 0;