ObjC kindof: check the context when inserting methods to global pool.

To make kindof lookup work, we need to insert methods with different
context into the global pool, even though they have the same siganture.

Since diagnosis of availability is performed on the best candidate,
which is often the first candidate from the global pool, we prioritize
the methods that are unavaible or deprecated to the head of the list.

Since we now have more methods in the global pool, we need to watch
out for performance impact.

rdar://25635831

llvm-svn: 265877

6 files changed, 59 insertions, 5 deletions

diff --git a/clang/include/clang/Sema/ObjCMethodList.h b/clang/include/clang/Sema/ObjCMethodList.h
index 2c9350df742..80ccd363d27 100644
--- a/clang/include/clang/Sema/ObjCMethodList.h
+++ b/clang/include/clang/Sema/ObjCMethodList.h
@@ -33,6 +33,9 @@ struct ObjCMethodList {
   ObjCMethodList() { }
   ObjCMethodList(ObjCMethodDecl *M)
       : MethodAndHasMoreThanOneDecl(M, 0) {}
+  ObjCMethodList(const ObjCMethodList &L)
+      : MethodAndHasMoreThanOneDecl(L.MethodAndHasMoreThanOneDecl),
+        NextAndExtraBits(L.NextAndExtraBits) {}
 
   ObjCMethodList *getNext() const { return NextAndExtraBits.getPointer(); }
   unsigned getBits() const { return NextAndExtraBits.getInt(); }
diff --git a/clang/lib/Sema/SemaDeclObjC.cpp b/clang/lib/Sema/SemaDeclObjC.cpp
index 32244e9e195..a9cc0d61be9 100644
--- a/clang/lib/Sema/SemaDeclObjC.cpp
+++ b/clang/lib/Sema/SemaDeclObjC.cpp
@@ -3167,6 +3167,26 @@ bool Sema::MatchTwoMethodDeclarations(const ObjCMethodDecl *left,
   return true;
 }
 
+static bool isMethodContextSameForKindofLookup(ObjCMethodDecl *Method,
+                                               ObjCMethodDecl *MethodInList) {
+  auto *MethodProtocol = dyn_cast<ObjCProtocolDecl>(Method->getDeclContext());
+  auto *MethodInListProtocol =
+      dyn_cast<ObjCProtocolDecl>(MethodInList->getDeclContext());
+  // If this method belongs to a protocol but the method in list does not, or
+  // vice versa, we say the context is not the same.
+  if ((MethodProtocol && !MethodInListProtocol) ||
+      (!MethodProtocol && MethodInListProtocol))
+    return false;
+
+  if (MethodProtocol && MethodInListProtocol)
+    return true;
+
+  ObjCInterfaceDecl *MethodInterface = Method->getClassInterface();
+  ObjCInterfaceDecl *MethodInListInterface =
+      MethodInList->getClassInterface();
+  return MethodInterface == MethodInListInterface;
+}
+
 void Sema::addMethodToGlobalList(ObjCMethodList *List,
                                  ObjCMethodDecl *Method) {
   // Record at the head of the list whether there were 0, 1, or >= 2 methods
@@ -3185,13 +3205,17 @@ 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;
   for (; List; Previous = List, List = List->getNext()) {
     // If we are building a module, keep all of the methods.
     if (getLangOpts().CompilingModule)
       continue;
 
-    if (!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()) ||
+        !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.
@@ -3232,6 +3256,19 @@ void Sema::addMethodToGlobalList(ObjCMethodList *List,
   // We have a new signature for an existing method - add it.
   // 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);
+    return;
+  }
+
   Previous->setNext(new (Mem) ObjCMethodList(Method));
 }
 
diff --git a/clang/test/FixIt/typo.m b/clang/test/FixIt/typo.m
index 381233f95c2..143d026b2be 100644
--- a/clang/test/FixIt/typo.m
+++ b/clang/test/FixIt/typo.m
@@ -103,7 +103,7 @@ void test2(Collide *a) {
 @end
 
 @interface Sub : Super
-- (int)method;
+- (int)method; // expected-note{{also found}}
 @end
 
 @implementation Sub
diff --git a/clang/test/SemaObjC/kindof.m b/clang/test/SemaObjC/kindof.m
index 36c9b8f0a2b..95c7f993d17 100644
--- a/clang/test/SemaObjC/kindof.m
+++ b/clang/test/SemaObjC/kindof.m
@@ -275,6 +275,20 @@ void test(__kindof Bar *kBar) {
     [kBar test];
 }
 
+// Make sure we don't emit warning about no method found.
+typedef signed char BOOL;
+@interface A : NSObject
+@property (readonly, getter=isActive) BOOL active;
+@end
+@interface B : NSObject
+@property (getter=isActive, readonly) BOOL active;
+@end
+void foo() {
+  __kindof B *NSApp;
+  if ([NSApp isActive]) {
+  }
+}
+
 // ---------------------------------------------------------------------------
 // __kindof within specialized types
 // ---------------------------------------------------------------------------
diff --git a/clang/test/SemaObjC/multiple-method-names.m b/clang/test/SemaObjC/multiple-method-names.m
index 9fd83b208ab..a8707904b56 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 {{using}}
+- (void)foo:(float)i; // expected-note {{also found}}
 @end
 
 @interface Face1
-- (void)foo:(int)i __attribute__((unavailable));
+- (void)foo:(int)i __attribute__((unavailable)); // expected-note {{using}}
 @end
 
 @interface Face2
diff --git a/clang/test/SemaObjC/warn-strict-selector-match.m b/clang/test/SemaObjC/warn-strict-selector-match.m
index 13e9bac462f..6b92cb805df 100644
--- a/clang/test/SemaObjC/warn-strict-selector-match.m
+++ b/clang/test/SemaObjC/warn-strict-selector-match.m
@@ -49,7 +49,7 @@ id foo(void) {
 @end
 
 @implementation NTGridDataObject
-- (id)initWithData:(id<MyObject, MyCoding>)data {
+- (id)initWithData:(id<MyObject, MyCoding>)data { // expected-note {{also found}}
   return data;
 }
 + (NTGridDataObject*)dataObject:(id<MyObject, MyCoding>)data