Always emit bitfield properties using expression behavior, even if they're

atomic.  This is probably something we should warn about.

llvm-svn: 139584

clang/lib/CodeGen/CGObjC.cpp

@@ -495,6 +495,13 @@ PropertyImplStrategy::PropertyImplStrategy(CodeGenModule &CGM,
     return;
   }
 
+  // Properties on bitfield ivars need to be emitted using expression
+  // accesses even if they're nominally atomic.
+  if (ivar->isBitField()) {
+    Kind = Expression;
+    return;
+  }
+
   // GC-qualified or ARC-qualified ivars need to be emitted as
   // expressions.  This actually works out to being atomic anyway,
   // except for ARC __strong, but that should trigger the above code.

clang/test/CodeGenObjC/property.m

@@ -103,3 +103,12 @@ void test4(Test4 *t) {
   // CHECK-NEXT: ret void
   test4_printf("%.2f", t.f);
 }
+
+@interface Test5 {
+  unsigned _x : 5;
+}
+@property unsigned x;
+@end
+@implementation Test5
+@synthesize x = _x;
+@end