Add Support for 'warn_unused_result" attribute on
objective-c methods. (radar 7418262).

llvm-svn: 99903
diff --git a/clang/lib/Sema/SemaStmt.cpp b/clang/lib/Sema/SemaStmt.cpp
index 733022a..1e37bb0 100644
--- a/clang/lib/Sema/SemaStmt.cpp
+++ b/clang/lib/Sema/SemaStmt.cpp
@@ -119,7 +119,13 @@
       }
     }        
   }
-
+  else if (const ObjCMessageExpr *ME = dyn_cast<ObjCMessageExpr>(E)) {
+    const ObjCMethodDecl *MD = ME->getMethodDecl();
+    if (MD && MD->getAttr<WarnUnusedResultAttr>()) {
+      Diag(Loc, diag::warn_unused_call) << R1 << R2 << "warn_unused_result";
+      return;
+    }
+  }
   Diag(Loc, DiagID) << R1 << R2;
 }