5 files changed, 27 insertions, 0 deletions
diff --git a/lib/Frontend/PCHReaderDecl.cpp b/lib/Frontend/PCHReaderDecl.cpp
index e623b6f1d7..3db00ec1b7 100644
--- a/lib/Frontend/PCHReaderDecl.cpp
+++ b/lib/Frontend/PCHReaderDecl.cpp
@@ -452,6 +452,13 @@ Attr *PCHReader::ReadAttributes() {
       New = ::new (*Context) FormatAttr(Type, FormatIdx, FirstArg);
       break;
     }
+        
+    case Attr::Sentinel: {
+      int sentinel = Record[Idx++];
+      int nullPos = Record[Idx++];
+      New = ::new (*Context) SentinelAttr(sentinel, nullPos);
+      break;
+    }
 
     SIMPLE_ATTR(GNUInline);
     
diff --git a/lib/Frontend/PCHWriter.cpp b/lib/Frontend/PCHWriter.cpp
index dbe0e536e5..e05a73568f 100644
--- a/lib/Frontend/PCHWriter.cpp
+++ b/lib/Frontend/PCHWriter.cpp
@@ -1556,6 +1556,13 @@ void PCHWriter::WriteAttributeRecord(const Attr *Attr) {
       break;
     }
 
+    case Attr::Sentinel : {
+      const SentinelAttr *Sentinel = cast<SentinelAttr>(Attr);
+      Record.push_back(Sentinel->getSentinel());
+      Record.push_back(Sentinel->getNullPos());
+      break;
+    }
+        
     case Attr::GNUInline:
     case Attr::IBOutletKind:
     case Attr::NoReturn:
diff --git a/lib/Sema/Sema.h b/lib/Sema/Sema.h
index 2e617f573b..8c38c2bfd2 100644
--- a/lib/Sema/Sema.h
+++ b/lib/Sema/Sema.h
@@ -1274,6 +1274,8 @@ public:
   bool DiagnosePropertyAccessorMismatch(ObjCPropertyDecl *PD, 
                                         ObjCMethodDecl *Getter,
                                         SourceLocation Loc);
+  void DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc,
+                             Expr **Args, unsigned NumArgs);
 
   // Primary Expressions.
   virtual SourceRange getExprRange(ExprTy *E) const;
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index d2e84c10e2..f1da408669 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -88,6 +88,15 @@ bool Sema::DiagnoseUseOfDecl(NamedDecl *D, SourceLocation Loc) {
   return false;
 }
 
+/// DiagnoseSentinelCalls - This routine checks on method dispatch calls
+/// (and other functions in future), which have been declared with sentinel 
+/// attribute. It warns if call does not have the sentinel argument.
+///
+void Sema::DiagnoseSentinelCalls(NamedDecl *D, SourceLocation Loc,
+                                 Expr **Args, unsigned NumArgs)
+{
+}
+
 SourceRange Sema::getExprRange(ExprTy *E) const {
   Expr *Ex = (Expr *)E;
   return Ex? Ex->getSourceRange() : SourceRange();
diff --git a/lib/Sema/SemaExprObjC.cpp b/lib/Sema/SemaExprObjC.cpp
index de6b69f90f..0073fd9f28 100644
--- a/lib/Sema/SemaExprObjC.cpp
+++ b/lib/Sema/SemaExprObjC.cpp
@@ -626,6 +626,8 @@ Sema::ExprResult Sema::ActOnInstanceMessage(ExprTy *receiver, Selector Sel,
     return true;
   }
   
+  if (Method)
+    DiagnoseSentinelCalls(Method, receiverLoc, ArgExprs, NumArgs);
   if (CheckMessageArgumentTypes(ArgExprs, NumArgs, Sel, Method, false,
                                 lbrac, rbrac, returnType))
     return true;