2 files changed, 16 insertions, 4 deletions
diff --git a/lib/AST/Expr.cpp b/lib/AST/Expr.cpp
index 5d22d144f4..5b511cc883 100644
--- a/lib/AST/Expr.cpp
+++ b/lib/AST/Expr.cpp
@@ -2728,11 +2728,18 @@ Expr::isNullPointerConstant(ASTContext &Ctx,
     return NPCK_NotNull;
 
   // If we have an integer constant expression, we need to *evaluate* it and
-  // test for the value 0.
-  llvm::APSInt Result;
-  bool IsNull = isIntegerConstantExpr(Result, Ctx) && Result == 0;
+  // test for the value 0. Don't use the C++11 constant expression semantics
+  // for this, for now; once the dust settles on core issue 903, we might only
+  // allow a literal 0 here in C++11 mode.
+  if (Ctx.getLangOptions().CPlusPlus0x) {
+    if (!isCXX98IntegralConstantExpr(Ctx))
+      return NPCK_NotNull;
+  } else {
+    if (!isIntegerConstantExpr(Ctx))
+      return NPCK_NotNull;
+  }
 
-  return (IsNull ? NPCK_ZeroInteger : NPCK_NotNull);
+  return (EvaluateKnownConstInt(Ctx) == 0) ? NPCK_ZeroInteger : NPCK_NotNull;
 }
 
 /// \brief If this expression is an l-value for an Objective C
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index c0fff5e478..787e722a7c 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -6435,12 +6435,17 @@ bool Expr::isIntegerConstantExpr(llvm::APSInt &Value, ASTContext &Ctx,
   return true;
 }
 
+bool Expr::isCXX98IntegralConstantExpr(ASTContext &Ctx) const {
+  return CheckICE(this, Ctx).Val == 0;
+}
+
 bool Expr::isCXX11ConstantExpr(ASTContext &Ctx, APValue *Result,
                                SourceLocation *Loc) const {
   // We support this checking in C++98 mode in order to diagnose compatibility
   // issues.
   assert(Ctx.getLangOptions().CPlusPlus);
 
+  // Build evaluation settings.
   Expr::EvalStatus Status;
   llvm::SmallVector<PartialDiagnosticAt, 8> Diags;
   Status.Diag = &Diags;