This is a warning about using 'assign' instead of 'unsafe_unretained'
in Objective-C property declarations. It's off by default because there
isn't consensus in the Objective-C steering group that this is the right
thing to do, but we're nonetheless okay with adding it because there's a
substantial pool of Objective-C programmers who will appreciate the warning.
Patch by Alfred Zien!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@341489
91177308-0d34-0410-b5e6-
96231b3b80d8
def BadFunctionCast : DiagGroup<"bad-function-cast">;
def ObjCPropertyImpl : DiagGroup<"objc-property-implementation">;
def ObjCPropertyNoAttribute : DiagGroup<"objc-property-no-attribute">;
+def ObjCPropertyAssignOnObjectType : DiagGroup<"objc-property-assign-on-object-type">;
def ObjCProtocolQualifiers : DiagGroup<"objc-protocol-qualifiers">;
def ObjCMissingSuperCalls : DiagGroup<"objc-missing-super-calls">;
def ObjCDesignatedInit : DiagGroup<"objc-designated-initializers">;
"property attributes '%0' and '%1' are mutually exclusive">;
def err_objc_property_requires_object : Error<
"property with '%0' attribute must be of object type">;
+def warn_objc_property_assign_on_object : Warning<
+ "'assign' property of object type may become a dangling reference; consider using 'unsafe_unretained'">,
+ InGroup<ObjCPropertyAssignOnObjectType>, DefaultIgnore;
def warn_objc_property_no_assignment_attribute : Warning<
"no 'assign', 'retain', or 'copy' attribute is specified - "
"'assign' is assumed">,
PropertyDecl->setInvalidDecl();
}
+ // Check for assign on object types.
+ if ((Attributes & ObjCDeclSpec::DQ_PR_assign) &&
+ !(Attributes & ObjCDeclSpec::DQ_PR_unsafe_unretained) &&
+ PropertyTy->isObjCRetainableType() &&
+ !PropertyTy->isObjCARCImplicitlyUnretainedType()) {
+ Diag(Loc, diag::warn_objc_property_assign_on_object);
+ }
+
// Check for more than one of { assign, copy, retain }.
if (Attributes & ObjCDeclSpec::DQ_PR_assign) {
if (Attributes & ObjCDeclSpec::DQ_PR_copy) {
--- /dev/null
+// RUN: %clang_cc1 -fsyntax-only -verify -Wobjc-property-assign-on-object-type %s
+
+@interface Foo @end
+@protocol Prot @end
+
+@interface Bar
+@property(assign, readonly) Foo* o1; // expected-warning {{'assign' property of object type may become a dangling reference; consider using 'unsafe_unretained'}}
+@property(unsafe_unretained, readonly) Foo* o2;
+
+@property(assign) Class classProperty;
+@property(assign) Class<Prot> classWithProtocolProperty;
+@property(assign) int s1;
+@property(assign) int* s2;
+@end
+
+@interface Bar ()
+@property(readwrite) Foo* o1;
+@property(readwrite) Foo* o2;
+@end
-// RUN: %clang_cc1 -fsyntax-only -triple x86_64-apple-darwin11 -fobjc-runtime-has-weak -fobjc-weak -verify -Weverything %s
-// RUN: %clang_cc1 -x objective-c++ -triple x86_64-apple-darwin11 -fobjc-runtime-has-weak -fobjc-weak -fsyntax-only -verify -Weverything %s
+// RUN: %clang_cc1 -fsyntax-only -triple x86_64-apple-darwin11 -fobjc-runtime-has-weak -fobjc-weak -verify -Wproperty-attribute-mismatch %s
+// RUN: %clang_cc1 -x objective-c++ -triple x86_64-apple-darwin11 -fobjc-runtime-has-weak -fobjc-weak -fsyntax-only -verify -Wproperty-attribute-mismatch %s
// rdar://12103400
@class NSString;