Warn when message is sent to receiver of

unknown type and there is a possibility that
at runtime method is resolved to a deprecated or 
unavailable method.  Addreses // rdar://8769853


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@122294 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 40 insertions, 13 deletions

diff --git a/lib/Sema/SemaDeclAttr.cpp b/lib/Sema/SemaDeclAttr.cpp
index e77a660ada..06cb42ec0e 100644
--- a/lib/Sema/SemaDeclAttr.cpp
+++ b/lib/Sema/SemaDeclAttr.cpp
@@ -2903,7 +2903,8 @@ void Sema::HandleDelayedDeprecationCheck(DelayedDiagnostic &DD,
 }
 
 void Sema::EmitDeprecationWarning(NamedDecl *D, llvm::StringRef Message,
-                                  SourceLocation Loc) {
+                                  SourceLocation Loc,
+                                  bool UnkownObjCClass) {
   // Delay if we're currently parsing a declaration.
   if (ParsingDeclDepth) {
     DelayedDiagnostics.push_back(DelayedDiagnostic::makeDeprecation(Loc, D, 
@@ -2917,6 +2918,10 @@ void Sema::EmitDeprecationWarning(NamedDecl *D, llvm::StringRef Message,
   if (!Message.empty())
     Diag(Loc, diag::warn_deprecated_message) << D->getDeclName() 
                                              << Message;
-  else
-    Diag(Loc, diag::warn_deprecated) << D->getDeclName();
+  else {
+    if (!UnkownObjCClass)
+      Diag(Loc, diag::warn_deprecated) << D->getDeclName();
+    else
+      Diag(Loc, diag::warn_deprecated_fwdclass_message) << D->getDeclName();
+  }
 }
diff --git a/lib/Sema/SemaDeclObjC.cpp b/lib/Sema/SemaDeclObjC.cpp
index 38e91465d2..5d9a924ed8 100644
--- a/lib/Sema/SemaDeclObjC.cpp
+++ b/lib/Sema/SemaDeclObjC.cpp
@@ -1302,7 +1302,21 @@ void Sema::AddMethodToGlobalPool(ObjCMethodDecl *Method, bool impl,
   // signature.
   for (ObjCMethodList *List = &Entry; List; List = List->Next)
     if (MatchTwoMethodDeclarations(Method, List->Method)) {
-      List->Method->setDefined(impl);
+      ObjCMethodDecl *PrevObjCMethod = List->Method;
+      PrevObjCMethod->setDefined(impl);
+      // If a method is deprecated, push it in the global pool.
+      // This is used for better diagnostics.
+      if (Method->getAttr<DeprecatedAttr>()) {
+        if (!PrevObjCMethod->getAttr<DeprecatedAttr>())
+          List->Method = Method;
+      }
+      // If new method is unavailable, push it into global pool
+      // unless previous one is deprecated.
+      if (Method->getAttr<UnavailableAttr>()) {
+        if (!PrevObjCMethod->getAttr<UnavailableAttr>() &&
+            !PrevObjCMethod->getAttr<DeprecatedAttr>())
+          List->Method = Method;
+      }
       return;
     }
 
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 01a505bb08..56ad9b4241 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -49,13 +49,14 @@ using namespace sema;
 /// used, or produce an error (and return true) if a C++0x deleted
 /// function is being used.
 ///
-/// If IgnoreDeprecated is set to true, this should not want about deprecated
+/// If IgnoreDeprecated is set to true, this should not warn about deprecated
 /// decls.
 ///
 /// \returns true if there was an error (this declaration cannot be
 /// referenced), false otherwise.
 ///
-bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) {
+bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc,
+                             bool UnkownObjCClass) {
   if (getLangOptions().CPlusPlus && isa<FunctionDecl>(D)) {
     // If there were any diagnostics suppressed by template argument deduction,
     // emit them now.
@@ -76,13 +77,18 @@ bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) {
 
   // See if the decl is deprecated.
   if (const DeprecatedAttr *DA = D->getAttr<DeprecatedAttr>())
-    EmitDeprecationWarning(D, DA->getMessage(), Loc);
+    EmitDeprecationWarning(D, DA->getMessage(), Loc, UnkownObjCClass);
 
   // See if the decl is unavailable
   if (const UnavailableAttr *UA = D->getAttr<UnavailableAttr>()) {
-    if (UA->getMessage().empty())
-      Diag(Loc, diag::err_unavailable) << D->getDeclName();
-    else
+    if (UA->getMessage().empty()) {
+      if (!UnkownObjCClass)
+        Diag(Loc, diag::err_unavailable) << D->getDeclName();
+      else
+        Diag(Loc, diag::warn_unavailable_fwdclass_message) 
+             << D->getDeclName();
+    }
+    else 
       Diag(Loc, diag::err_unavailable_message) 
         << D->getDeclName() << UA->getMessage();
     Diag(D->getLocation(), diag::note_unavailable_here) << 0;
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index baa34f9ce8..bbb047990b 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -1023,6 +1023,7 @@ ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
               break;
           }
         }
+        bool forwardClass = false;
         if (!Method) {
           // If we have implementations in scope, check "private" methods.
           Method = LookupPrivateInstanceMethod(Sel, ClassDecl);
@@ -1033,14 +1034,15 @@ ExprResult Sema::BuildInstanceMessage(Expr *Receiver,
             // compatibility. FIXME: should we deviate??
             if (OCIType->qual_empty()) {
               Method = LookupInstanceMethodInGlobalPool(Sel,
-                                                 SourceRange(LBracLoc, RBracLoc)); 
-              if (Method && !OCIType->getInterfaceDecl()->isForwardDecl())
+                                                 SourceRange(LBracLoc, RBracLoc));
+              forwardClass = OCIType->getInterfaceDecl()->isForwardDecl();
+              if (Method && !forwardClass)
                 Diag(Loc, diag::warn_maynot_respond)
                   << OCIType->getInterfaceDecl()->getIdentifier() << Sel;
             }
           }
         }
-        if (Method && DiagnoseUseOfDecl(Method, Loc))
+        if (Method && DiagnoseUseOfDecl(Method, Loc, forwardClass))
           return ExprError();
       } else if (!Context.getObjCIdType().isNull() &&
                  (ReceiverType->isPointerType() ||