Consolidate ObjC lookupPrivateMethod methods from Sema and DeclObjC.

Also, fix a subtle bug, which occurred due to lookupPrivateMethod
defined in DeclObjC.h not looking up the method inside parent's
categories.

Note, the code assumes that Class's parent object has the same methods
as what's in the Root class of a the hierarchy, which is a heuristic
that might not hold for hierarchies which do not descend from NSObject.
Would be great to fix this in the future.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160885 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 20 insertions, 1 deletions

diff --git a/lib/AST/DeclObjC.cpp b/lib/AST/DeclObjC.cpp
index 39f09063e9..cbd15240b1 100644
--- a/lib/AST/DeclObjC.cpp
+++ b/lib/AST/DeclObjC.cpp
@@ -363,6 +363,9 @@ ObjCMethodDecl *ObjCInterfaceDecl::lookupMethod(Selector Sel,
   return NULL;
 }
 
+// Will search "local" class/category implementations for a method decl.
+// If failed, then we search in class's root for an instance method.
+// Returns 0 if no method is found.
 ObjCMethodDecl *ObjCInterfaceDecl::lookupPrivateMethod(
                                    const Selector &Sel,
                                    bool Instance) {
@@ -377,7 +380,23 @@ ObjCMethodDecl *ObjCInterfaceDecl::lookupPrivateMethod(
   if (ObjCImplementationDecl *ImpDecl = getImplementation())
     Method = Instance ? ImpDecl->getInstanceMethod(Sel) 
                       : ImpDecl->getClassMethod(Sel);
-  
+
+  // Look through local category implementations associated with the class.
+  if (!Method)
+    Method = Instance ? getCategoryInstanceMethod(Sel)
+                      : getCategoryClassMethod(Sel);
+
+  // Before we give up, check if the selector is an instance method.
+  // But only in the root. This matches gcc's behavior and what the
+  // runtime expects.
+  if (!Instance && !Method && !getSuperClass()) {
+    Method = lookupInstanceMethod(Sel);
+    // Look through local category implementations associated
+    // with the root class.
+    if (!Method)
+      Method = lookupPrivateMethod(Sel, true);
+  }
+
   if (!Method && getSuperClass())
     return getSuperClass()->lookupPrivateMethod(Sel, Instance);
   return Method;