3 files changed, 27 insertions, 5 deletions
diff --git a/include/clang/AST/Expr.h b/include/clang/AST/Expr.h
index 36644784c9..a17205c2b6 100644
--- a/include/clang/AST/Expr.h
+++ b/include/clang/AST/Expr.h
@@ -437,6 +437,22 @@ public:
   /// EvaluateAsLValue - Evaluate an expression to see if it's a lvalue.
   bool EvaluateAsAnyLValue(EvalResult &Result, const ASTContext &Ctx) const;
 
+  /// \brief Enumeration used to describe the kind of Null pointer constant
+  /// returned from \c isNullPointerConstant().
+  enum NullPointerConstantKind {
+    /// \brief Expression is not a Null pointer constant.
+    NPCK_NotNull = 0,
+
+    /// \brief Expression is a Null pointer constant built from a zero integer.
+    NPCK_ZeroInteger,
+
+    /// \brief Expression is a C++0X nullptr.
+    NPCK_CXX0X_nullptr,
+
+    /// \brief Expression is a GNU-style __null constant.
+    NPCK_GNUNull
+  };
+
   /// \brief Enumeration used to describe how \c isNullPointerConstant()
   /// should cope with value-dependent expressions.
   enum NullPointerConstantValueDependence {
@@ -452,11 +468,12 @@ public:
     NPC_ValueDependentIsNotNull
   };
   
-  /// isNullPointerConstant - C99 6.3.2.3p3 -  Return true if this is either an
-  /// integer constant expression with the value zero, or if this is one that is
-  /// cast to void*.
-  bool isNullPointerConstant(ASTContext &Ctx,
-                             NullPointerConstantValueDependence NPC) const;
+  /// isNullPointerConstant - C99 6.3.2.3p3 - Test if this reduces down to
+  /// a Null pointer constant. The return value can further distinguish the
+  /// kind of NULL pointer constant that was detected.
+  NullPointerConstantKind isNullPointerConstant(
+      ASTContext &Ctx,
+      NullPointerConstantValueDependence NPC) const;
 
   /// isOBJCGCCandidate - Return true if this expression may be used in a read/
   /// write barrier.
diff --git a/include/clang/Basic/DiagnosticSemaKinds.td b/include/clang/Basic/DiagnosticSemaKinds.td
index 7b28463349..9592cbb36f 100644
--- a/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3147,6 +3147,8 @@ def err_incomplete_type_used_in_type_trait_expr : Error<
   "incomplete type %0 used in type trait expression">;
 def err_expected_ident_or_lparen : Error<"expected identifier or '('">;
 
+def err_typecheck_cond_incompatible_operands_null : Error<
+  "non-pointer operand type %0 incompatible with %select{NULL|nullptr}1">;
 } // End of general sema category.
 
 // inline asm.
diff --git a/include/clang/Sema/Sema.h b/include/clang/Sema/Sema.h
index 8d8cf09912..4e3173ab09 100644
--- a/include/clang/Sema/Sema.h
+++ b/include/clang/Sema/Sema.h
@@ -4774,6 +4774,9 @@ public:
   QualType FindCompositeObjCPointerType(Expr *&LHS, Expr *&RHS,
                                         SourceLocation questionLoc);
 
+  bool DiagnoseConditionalForNull(Expr *LHS, Expr *RHS,
+                                  SourceLocation QuestionLoc);
+
   /// type checking for vector binary operators.
   QualType CheckVectorOperands(SourceLocation l, Expr *&lex, Expr *&rex);
   QualType CheckVectorCompareOperands(Expr *&lex, Expr *&rx,