Objective-C. Do not issue warning when 'readonly'

property declaration has a memory management
attribute (retain, copy, etc.). Sich properties
are usually overridden to become 'readwrite'
via a class extension (which require the memory
management attribute specified). In the absence of class
extension override, memory management attribute is
needed to produce correct Code Gen. for the
property getter in any case and this warning becomes
confusing to user. // rdar://15641300

llvm-svn: 197251

clang/include/clang/Basic/DiagnosticGroups.td

@@ -365,7 +365,6 @@ def UnusedVariable : DiagGroup<"unused-variable",
 def UnusedPropertyIvar :  DiagGroup<"unused-property-ivar">;
 def UsedButMarkedUnused : DiagGroup<"used-but-marked-unused">;
 def UserDefinedLiterals : DiagGroup<"user-defined-literals">;
-def ReadOnlySetterAttrs : DiagGroup<"readonly-setter-attrs">;
 def Reorder : DiagGroup<"reorder">;
 def UndeclaredSelector : DiagGroup<"undeclared-selector">;
 def ImplicitAtomic : DiagGroup<"implicit-atomic-properties">;

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -822,9 +822,6 @@ def error_dynamic_property_ivar_decl : Error<
 def error_duplicate_ivar_use : Error<
   "synthesized properties %0 and %1 both claim instance variable %2">;
 def error_property_implemented : Error<"property %0 is already implemented">;
-def warn_objc_property_attr_mutually_exclusive : Warning<
-  "property attributes '%0' and '%1' are mutually exclusive">,
-  InGroup<ReadOnlySetterAttrs>, DefaultIgnore;
 def warn_objc_missing_super_call : Warning<
   "method possibly missing a [super %0] call">,
   InGroup<ObjCMissingSuperCalls>;

clang/lib/Sema/SemaObjCProperty.cpp

@@ -321,21 +321,6 @@ static unsigned getOwnershipRule(unsigned attr) {
                  ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
 }
 
-static const char *NameOfOwnershipAttribute(unsigned attr) {
-  if (attr & ObjCPropertyDecl::OBJC_PR_assign)
-    return "assign";
-  if (attr & ObjCPropertyDecl::OBJC_PR_retain )
-    return "retain";
-  if (attr & ObjCPropertyDecl::OBJC_PR_copy)
-    return "copy";
-  if (attr & ObjCPropertyDecl::OBJC_PR_weak)
-    return "weak";
-  if (attr & ObjCPropertyDecl::OBJC_PR_strong)
-    return "strong";
-  assert(attr & ObjCPropertyDecl::OBJC_PR_unsafe_unretained);
-  return "unsafe_unretained";
-}
-
 ObjCPropertyDecl *
 Sema::HandlePropertyInClassExtension(Scope *S,
                                      SourceLocation AtLoc,
@@ -2057,21 +2042,13 @@ void Sema::CheckObjCPropertyAttributes(Decl *PDecl,
   QualType PropertyTy = PropertyDecl->getType();
   unsigned PropertyOwnership = getOwnershipRule(Attributes);
 
-  if (Attributes & ObjCDeclSpec::DQ_PR_readonly) {
+  // 'readonly' property with no obvious lifetime.
-    if (getLangOpts().ObjCAutoRefCount &&
+  // its life time will be determined by its backing ivar.
-        PropertyTy->isObjCRetainableType() &&
+  if (getLangOpts().ObjCAutoRefCount &&
-        !PropertyOwnership) {
+      Attributes & ObjCDeclSpec::DQ_PR_readonly &&
-      // 'readonly' property with no obvious lifetime.
+      PropertyTy->isObjCRetainableType() &&
-      // its life time will be determined by its backing ivar.
+      !PropertyOwnership)
-      return;
+    return;
-    }
-    else if (PropertyOwnership) {
-      if (!getSourceManager().isInSystemHeader(Loc))
-        Diag(Loc, diag::warn_objc_property_attr_mutually_exclusive)
-          << "readonly" << NameOfOwnershipAttribute(Attributes);
-      return;
-    }
-  }
 
   // Check for copy or retain on non-object types.
   if ((Attributes & (ObjCDeclSpec::DQ_PR_weak | ObjCDeclSpec::DQ_PR_copy |

clang/test/SemaObjC/overriding-property-in-class-extension.m

@@ -1,4 +1,5 @@
 // RUN: %clang_cc1  -fsyntax-only -verify -Weverything %s
+// expected-no-diagnostics
 // rdar://12103434
 
 @class NSString;
@@ -7,7 +8,7 @@
 
 @interface MyClass  : NSObject
 
-@property (nonatomic, copy, readonly) NSString* name; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property (nonatomic, copy, readonly) NSString* name;
 
 @end
 

clang/test/SemaObjC/property-12.m

@@ -1,15 +1,15 @@
-// RUN: %clang_cc1 -fsyntax-only -Wno-objc-root-class -Wreadonly-setter-attrs -verify %s
+// RUN: %clang_cc1 -fsyntax-only -Wno-objc-root-class -verify %s
 
 @protocol P0
-@property(readonly,assign) id X; // expected-warning {{property attributes 'readonly' and 'assign' are mutually exclusive}}
+@property(readonly,assign) id X;
 @end
 
 @protocol P1
-@property(readonly,retain) id X; // expected-warning {{property attributes 'readonly' and 'retain' are mutually exclusive}}
+@property(readonly,retain) id X;
 @end
 
 @protocol P2
-@property(readonly,copy) id X; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property(readonly,copy) id X;
 @end
 
 @protocol P3

clang/test/SemaObjC/property-in-class-extension-1.m

@@ -8,20 +8,19 @@
 
 @property (nonatomic, readonly) NSString* addingMemoryModel;
 
-@property (nonatomic, copy, readonly) NSString* matchingMemoryModel; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property (nonatomic, copy, readonly) NSString* matchingMemoryModel;
 
-@property (nonatomic, retain, readonly) NSString* addingNoNewMemoryModel; // expected-warning {{property attributes 'readonly' and 'retain' are mutually exclusive}}
+@property (nonatomic, retain, readonly) NSString* addingNoNewMemoryModel;
 
 @property (readonly) NSString* none;
 @property (readonly) NSString* none1;
 
-@property (assign, readonly) NSString* changeMemoryModel; // expected-note {{property declared here}} \
+@property (assign, readonly) NSString* changeMemoryModel; // expected-note {{property declared here}}
-                                                          // expected-warning {{property attributes 'readonly' and 'assign' are mutually exclusive}}
 
 @property (readonly) __weak id weak_prop;
 @property (readonly) __weak id weak_prop1;
 
-@property (assign, readonly) NSString* assignProperty; // expected-warning {{property attributes 'readonly' and 'assign' are mutually exclusive}}
+@property (assign, readonly) NSString* assignProperty;
 
 @property (readonly) NSString* readonlyProp;
 

clang/test/SemaObjC/tentative-property-decl.m

@@ -1,10 +1,11 @@
 // RUN: %clang_cc1 -fsyntax-only -Weverything -verify %s
+// expected-no-diagnostics
 // rdar://11656982
-/** Normally, a property cannot be both 'readonly' and having a "write" attribute
+/** A property may not be both 'readonly' and having a memory management attribute
     (copy/retain/etc.). But, property declaration in primary class and protcols
     are tentative as they may be overridden into a 'readwrite' property in class 
-    extensions. Postpone diagnosing such warnings until the class implementation 
+    extensions. So, do not issue any warning on 'readonly' and memory management
-    is seen.
+    attributes in a property.
 */
 
 @interface Super {
@@ -14,8 +15,8 @@
 @class NSString;
 
 @interface MyClass : Super
-@property(nonatomic, copy, readonly) NSString *prop; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property(nonatomic, copy, readonly) NSString *prop;
-@property(nonatomic, copy, readonly) id warnProp; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property(nonatomic, copy, readonly) id warnProp;
 @end
 
 @interface MyClass ()
@@ -29,8 +30,8 @@
 
 
 @protocol P
-@property(nonatomic, copy, readonly) NSString *prop; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property(nonatomic, copy, readonly) NSString *prop;
-@property(nonatomic, copy, readonly) id warnProp; // expected-warning {{property attributes 'readonly' and 'copy' are mutually exclusive}}
+@property(nonatomic, copy, readonly) id warnProp;
 @end
 
 @interface YourClass : Super <P>