r176889 - Objective-C: Issue warning in couple of obscure cases

[Fariborz Jahanian]

Author: fjahanian
Date: Tue Mar 12 14:46:17 2013
New Revision: 176889

URL: http://llvm.org/viewvc/llvm-project?rev=176889&view=rev
Log:
Objective-C: Issue warning in couple of obscure cases
when property autosynthesis does not synthesize a property.
When property is declared 'readonly' in a super class and
is redeclared 'readwrite' in a subclass. When a property
autosynthesis causes it to share 'ivar' with another property.
// rdar://13388503

Modified:
    cfe/trunk/include/clang/Basic/DiagnosticGroups.td
    cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
    cfe/trunk/lib/Sema/SemaObjCProperty.cpp
    cfe/trunk/test/SemaObjC/default-synthesize-3.m

Modified: cfe/trunk/include/clang/Basic/DiagnosticGroups.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticGroups.td?rev=176889&r1=176888&r2=176889&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticGroups.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticGroups.td Tue Mar 12 14:46:17 2013
@@ -490,6 +490,8 @@ def ObjCNonUnifiedException : DiagGroup<
 
 def ObjCProtocolMethodImpl : DiagGroup<"objc-protocol-method-implementation">;
 
+def ObjCNoPropertyAuthoSynthesis : DiagGroup<"objc-property-synthesis">;
+
 // ObjC API warning groups.
 def ObjCRedundantLiteralUse : DiagGroup<"objc-redundant-literal-use">;
 def ObjCRedundantAPIUse : DiagGroup<"objc-redundant-api-use", [

Modified: cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td?rev=176889&r1=176888&r2=176889&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td (original)
+++ cfe/trunk/include/clang/Basic/DiagnosticSemaKinds.td Tue Mar 12 14:46:17 2013
@@ -666,6 +666,15 @@ def warn_auto_synthesizing_protocol_prop
   "auto property synthesis will not synthesize property"
   " declared in a protocol">,
   InGroup<DiagGroup<"objc-protocol-property-synthesis">>;
+def warn_no_autosynthesis_shared_ivar_property : Warning <
+  "auto property synthesis will not synthesize property "
+  "'%0' because it cannot share an ivar with another synthesized property">,
+  InGroup<ObjCNoPropertyAuthoSynthesis>;
+def warn_no_autosynthesis_property : Warning<
+  "auto property synthesis will not synthesize property "
+  "'%0' because it is 'readwrite' but it will be synthesized 'readonly' "
+  "via another property">,
+  InGroup<ObjCNoPropertyAuthoSynthesis>;
 def warn_autosynthesis_property_ivar_match :Warning<
   "autosynthesized property %0 will use %select{|synthesized}1 instance variable "
   "%2, not existing instance variable %3">,

Modified: cfe/trunk/lib/Sema/SemaObjCProperty.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaObjCProperty.cpp?rev=176889&r1=176888&r2=176889&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaObjCProperty.cpp (original)
+++ cfe/trunk/lib/Sema/SemaObjCProperty.cpp Tue Mar 12 14:46:17 2013
@@ -1585,13 +1585,31 @@ void Sema::DefaultSynthesizeProperties(S
   for (unsigned i = 0, e = PropertyOrder.size(); i != e; i++) {
     ObjCPropertyDecl *Prop = PropertyOrder[i];
     // If property to be implemented in the super class, ignore.
-    if (SuperPropMap[Prop->getIdentifier()])
+    if (SuperPropMap[Prop->getIdentifier()]) {
+      ObjCPropertyDecl *PropInSuperClass = SuperPropMap[Prop->getIdentifier()];
+      if ((Prop->getPropertyAttributes() & ObjCPropertyDecl::OBJC_PR_readwrite) &&
+          (PropInSuperClass->getPropertyAttributes() &
+           ObjCPropertyDecl::OBJC_PR_readonly)) {
+            Diag(Prop->getLocation(), diag::warn_no_autosynthesis_property)
+              << Prop->getIdentifier()->getName();
+            Diag(PropInSuperClass->getLocation(), diag::note_property_declare);
+      }
       continue;
+    }
     // Is there a matching property synthesize/dynamic?
     if (Prop->isInvalidDecl() ||
-        Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional ||
-        IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier()))
+        Prop->getPropertyImplementation() == ObjCPropertyDecl::Optional)
       continue;
+    if (ObjCPropertyImplDecl *PID =
+          IMPDecl->FindPropertyImplIvarDecl(Prop->getIdentifier())) {
+      if (PID->getPropertyDecl() != Prop) {
+        Diag(Prop->getLocation(), diag::warn_no_autosynthesis_shared_ivar_property)
+          << Prop->getIdentifier()->getName();
+        if (!PID->getLocation().isInvalid())
+          Diag(PID->getLocation(), diag::note_property_synthesize);
+      }
+      continue;
+    }
     // Property may have been synthesized by user.
     if (IMPDecl->FindPropertyImplDecl(Prop->getIdentifier()))
       continue;

Modified: cfe/trunk/test/SemaObjC/default-synthesize-3.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/default-synthesize-3.m?rev=176889&r1=176888&r2=176889&view=diff
==============================================================================
--- cfe/trunk/test/SemaObjC/default-synthesize-3.m (original)
+++ cfe/trunk/test/SemaObjC/default-synthesize-3.m Tue Mar 12 14:46:17 2013
@@ -39,3 +39,33 @@ __attribute ((objc_requires_property_def
 
 __attribute ((objc_requires_property_definitions)) // expected-error {{objc_requires_property_definitions attribute may only be specified on a class}} 
 @protocol P @end
+
+// rdar://13388503
+ at interface NSObject @end
+ at protocol Foo
+ at property (readonly) char isFoo; // expected-note {{property declared here}}
+ at end
+
+ at interface Bar : NSObject <Foo>
+ at end
+
+ at implementation Bar
+- (char)isFoo {
+    return 0;
+}
+ at end
+
+ at interface Baz : Bar
+ at end
+
+ at interface Baz ()
+ at property (readwrite) char isFoo; // expected-warning {{auto property synthesis will not synthesize property 'isFoo' because it is 'readwrite' but it will be synthesized 'readonly' via another property}}
+ at property char Property1; // expected-warning {{auto property synthesis will not synthesize property 'Property1' because it cannot share an ivar with another synthesized property}}
+ at property char Property2;
+ at end
+
+ at implementation Baz {
+    char _isFoo;
+}
+ at synthesize Property2 = Property1; // expected-note {{property synthesized here}}
+ at end