Implement the 'null_resettable' attribute for Objective-C properties.

'null_resettable' properties are those whose getters return nonnull
but whose setters take nil, to "reset" the property to some
default. Implements rdar://problem/19051334.

llvm-svn: 240155

1 files changed, 8 insertions, 2 deletions

diff --git a/clang/lib/AST/DeclPrinter.cpp b/clang/lib/AST/DeclPrinter.cpp
index 609cc08545a..d6c03169d9c 100644
--- a/clang/lib/AST/DeclPrinter.cpp
+++ b/clang/lib/AST/DeclPrinter.cpp
@@ -1213,8 +1213,14 @@ void DeclPrinter::VisitObjCPropertyDecl(ObjCPropertyDecl *PDecl) {
     if (PDecl->getPropertyAttributes() &
         ObjCPropertyDecl::OBJC_PR_nullability) {
       if (auto nullability = stripOuterNullability(T)) {
-        Out << (first ? ' ' : ',') 
-            << getNullabilitySpelling(*nullability).substr(2);
+        if (*nullability == NullabilityKind::Unspecified &&
+            (PDecl->getPropertyAttributes() &
+               ObjCPropertyDecl::OBJC_PR_null_resettable)) {
+          Out << (first ? ' ' : ',') << "null_resettable";
+        } else {
+          Out << (first ? ' ' : ',')
+              << getNullabilitySpelling(*nullability).substr(2);
+        }
         first = false;
       }
     }