Objective-C. Change to method lookup rules to look

into primary class's named categories before looking 
into their protocols. This is because categories are
part of the public interface and , just as primary class,
preference should be given to them before class 
(and category) protocols.  // rdar://18013929


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@216610 91177308-0d34-0410-b5e6-96231b3b80d8

lib/AST/DeclObjC.cpp

@@ -558,36 +558,39 @@ ObjCMethodDecl *ObjCInterfaceDecl::lookupMethod(Selector Sel,
     LoadExternalDefinition();
 
   while (ClassDecl) {
+    // 1. Look through primary class.
     if ((MethodDecl = ClassDecl->getMethod(Sel, isInstance)))
       return MethodDecl;
-
-    // Didn't find one yet - look through protocols.
-    for (const auto *I : ClassDecl->protocols())
-      if ((MethodDecl = I->lookupMethod(Sel, isInstance)))
-        return MethodDecl;
     
-    // Didn't find one yet - now look through categories.
-    for (const auto *Cat : ClassDecl->visible_categories()) {
+    // 2. Didn't find one yet - now look through categories.
+    for (const auto *Cat : ClassDecl->visible_categories())
       if ((MethodDecl = Cat->getMethod(Sel, isInstance)))
         if (C != Cat || !MethodDecl->isImplicit())
           return MethodDecl;
 
-      if (!shallowCategoryLookup) {
+    // 3. Didn't find one yet - look through primary class's protocols.
+    for (const auto *I : ClassDecl->protocols())
+      if ((MethodDecl = I->lookupMethod(Sel, isInstance)))
+        return MethodDecl;
+    
+    // 4. Didn't find one yet - now look through categories' protocols
+    if (!shallowCategoryLookup)
+      for (const auto *Cat : ClassDecl->visible_categories()) {
         // Didn't find one yet - look through protocols.
         const ObjCList<ObjCProtocolDecl> &Protocols =
-        Cat->getReferencedProtocols();
+          Cat->getReferencedProtocols();
         for (ObjCList<ObjCProtocolDecl>::iterator I = Protocols.begin(),
              E = Protocols.end(); I != E; ++I)
           if ((MethodDecl = (*I)->lookupMethod(Sel, isInstance)))
             if (C != Cat || !MethodDecl->isImplicit())
               return MethodDecl;
       }
-    }
-
+    
+    
     if (!followSuper)
       return nullptr;
 
-    // Get the super class (if any).
+    // 5. Get to the super class (if any).
     ClassDecl = ClassDecl->getSuperClass();
   }
   return nullptr;

test/SemaObjC/warn-category-method-deprecated.m

@@ -0,0 +1,17 @@
+// RUN: %clang_cc1 -fsyntax-only -Wno-objc-root-class -verify %s
+// rdar://18013929
+
+@protocol P
+- (void)meth;
+@end
+
+@interface I <P>
+@end
+
+@interface I(cat)
+- (void)meth __attribute__((deprecated)); // expected-note {{'meth' has been explicitly marked deprecated here}}
+@end
+
+void foo(I *i) {
+  [i meth]; // expected-warning {{'meth' is deprecated}}
+}