3 files changed, 45 insertions, 14 deletions

diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 58ee123688d..8090bec4fab 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -3213,22 +3213,43 @@ void Sema::addMethodToGlobalList(ObjCMethodList *List,
 
   // We've seen a method with this name, see if we have already seen this type
   // signature.
-  ObjCMethodList *Head = List;
   ObjCMethodList *Previous = List;
+  ObjCMethodList *ListWithSameDeclaration = nullptr;
   for (; List; Previous = List, List = List->getNext()) {
     // If we are building a module, keep all of the methods.
     if (getLangOpts().CompilingModule)
       continue;
 
+    bool SameDeclaration = MatchTwoMethodDeclarations(Method,
+                                                      List->getMethod());
     // Looking for method with a type bound requires the correct context exists.
-    // We need to insert this method into the list if the context is different.
-    if (!MatchTwoMethodDeclarations(Method, List->getMethod()) ||
+    // We need to insert a method into the list if the context is different.
+    // If the method's declaration matches the list
+    // a> the method belongs to a different context: we need to insert it, in
+    //    order to emit the availability message, we need to prioritize over
+    //    availability among the methods with the same declaration.
+    // b> the method belongs to the same context: there is no need to insert a
+    //    new entry.
+    // If the method's declaration does not match the list, we insert it to the
+    // end.
+    if (!SameDeclaration ||
         !isMethodContextSameForKindofLookup(Method, List->getMethod())) {
       // Even if two method types do not match, we would like to say
       // there is more than one declaration so unavailability/deprecated
       // warning is not too noisy.
       if (!Method->isDefined())
         List->setHasMoreThanOneDecl(true);
+
+      // For methods with the same declaration, the one that is deprecated
+      // should be put in the front for better diagnostics.
+      if (Method->isDeprecated() && SameDeclaration &&
+          !ListWithSameDeclaration && !List->getMethod()->isDeprecated())
+        ListWithSameDeclaration = List;
+
+      if (Method->isUnavailable() && SameDeclaration &&
+          !ListWithSameDeclaration &&
+          List->getMethod()->getAvailability() < AR_Deprecated)
+        ListWithSameDeclaration = List;
       continue;
     }
 
@@ -3265,15 +3286,12 @@ void Sema::addMethodToGlobalList(ObjCMethodList *List,
   // This is extremely rare. Only 1% of Cocoa selectors are "overloaded".
   ObjCMethodList *Mem = BumpAlloc.Allocate<ObjCMethodList>();
 
-  // We tried to prioritize the list by putting deprecated and unavailable
-  // methods in the front.
-  if ((Method->isDeprecated() && !Head->getMethod()->isDeprecated()) ||
-      (Method->isUnavailable() &&
-       Head->getMethod()->getAvailability() < AR_Deprecated)) {
-    auto *List = new (Mem) ObjCMethodList(*Head);
-    // FIXME: should we clear the other bits in Head?
-    Head->setMethod(Method);
-    Head->setNext(List);
+  // We insert it right before ListWithSameDeclaration.
+  if (ListWithSameDeclaration) {
+    auto *List = new (Mem) ObjCMethodList(*ListWithSameDeclaration);
+    // FIXME: should we clear the other bits in ListWithSameDeclaration?
+    ListWithSameDeclaration->setMethod(Method);
+    ListWithSameDeclaration->setNext(List);
     return;
   }
 
diff --git a/clang/test/SemaObjC/kindof.m b/clang/test/SemaObjC/kindof.m
index 95c7f993d17..919ca960a9d 100644
--- a/clang/test/SemaObjC/kindof.m
+++ b/clang/test/SemaObjC/kindof.m
@@ -25,6 +25,7 @@ __attribute__((objc_root_class))
 @end
 
 @interface NSString : NSObject <NSCopying> // expected-note{{receiver is instance of class declared here}}
+- (void)compare:(NSString *)string;
 - (NSString *)stringByAppendingString:(NSString *)string;
 + (instancetype)string;
 @end
@@ -289,6 +290,18 @@ void foo() {
   }
 }
 
+typedef const struct CGPath *CGPathRef;
+@interface C : NSObject
+@property (copy) NSString *path;
+@end
+@interface D : NSObject
+@property CGPathRef path __attribute__((availability(macosx,unavailable)));
+@end
+// Make sure we choose "NSString *path" for [s1 path].
+void bar(id s1, id s2) {
+  return [[s1 path] compare:[s2 path]];
+}
+
 // ---------------------------------------------------------------------------
 // __kindof within specialized types
 // ---------------------------------------------------------------------------
diff --git a/clang/test/SemaObjC/multiple-method-names.m b/clang/test/SemaObjC/multiple-method-names.m
index a8707904b56..9fd83b208ab 100644
--- a/clang/test/SemaObjC/multiple-method-names.m
+++ b/clang/test/SemaObjC/multiple-method-names.m
@@ -2,11 +2,11 @@
 // PR22047
 
 @interface Face0
-- (void)foo:(float)i; // expected-note {{also found}}
+- (void)foo:(float)i; // expected-note {{using}}
 @end
 
 @interface Face1
-- (void)foo:(int)i __attribute__((unavailable)); // expected-note {{using}}
+- (void)foo:(int)i __attribute__((unavailable));
 @end
 
 @interface Face2