Objective-C. When multiple nullary selectors are found in

global pool in the course of method selection for
a messaging expression, select one with the most general
return type of 'id'. This is to remove type-mismatch 
warning (which is useless) as result of random selection of 
method with more restrictive return type. rdar://18095772

llvm-svn: 216560

2 files changed, 32 insertions, 1 deletions

diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp
index 7bc42bfe9cb..95b1dc09062 100644
--- a/clang/lib/Sema/SemaOverload.cpp
+++ b/clang/lib/Sema/SemaOverload.cpp
@@ -5743,10 +5743,20 @@ ObjCMethodDecl *Sema::SelectBestMethod(Selector Sel, MultiExprArg Args,
           break;
         }
       }
-    } else
+    } else {
       // Check for extra arguments to non-variadic methods.
       if (Args.size() != NumNamedArgs)
         Match = false;
+      else if (Match && NumNamedArgs == 0 && Methods.size() > 1) {
+        // Special case when selectors have no argument. In this case, select
+        // one with the most general result type of 'id'.
+        for (unsigned b = 0, e = Methods.size(); b < e; b++) {
+          QualType ReturnT = Methods[b]->getReturnType();
+          if (ReturnT->isObjCIdType())
+            return Methods[b];
+        }
+      }
+    }
 
     if (Match)
       return Method;
diff --git a/clang/test/SemaObjC/resolve-method-in-global-pool.m b/clang/test/SemaObjC/resolve-method-in-global-pool.m
index 2c5dde4cba9..523856d663f 100644
--- a/clang/test/SemaObjC/resolve-method-in-global-pool.m
+++ b/clang/test/SemaObjC/resolve-method-in-global-pool.m
@@ -40,3 +40,24 @@
 void func( Class c, float g ) {
     [c clsMethod: &g];
 }
+
+// rdar://18095772
+@protocol NSKeyedArchiverDelegate @end
+
+@interface NSKeyedArchiver
+@property (assign) id <NSKeyedArchiverDelegate> delegate;
+@end
+
+@interface NSConnection
+@property (assign) id delegate;
+@end
+
+extern id NSApp;
+
+@interface AppDelegate
+@end
+
+AppDelegate* GetDelegate()
+{
+    return [NSApp delegate];
+}