Implement the GNU __null extension

llvm-svn: 60235

1 files changed, 8 insertions, 1 deletions

diff --git a/clang/lib/AST/Expr.cpp b/clang/lib/AST/Expr.cpp
index 7a8119c5e3d..3c021c262d6 100644
--- a/clang/lib/AST/Expr.cpp
+++ b/clang/lib/AST/Expr.cpp
@@ -1031,8 +1031,11 @@ bool Expr::isNullPointerConstant(ASTContext &Ctx) const {
                = dyn_cast<CXXDefaultArgExpr>(this)) {
     // See through default argument expressions
     return DefaultArg->getExpr()->isNullPointerConstant(Ctx);
+  } else if (isa<GNUNullExpr>(this)) {
+    // The GNU __null extension is always a null pointer constant.
+    return true;
   }
-  
+
   // This expression must be an integer type.
   if (!getType()->isIntegerType())
     return false;
@@ -1383,6 +1386,10 @@ Stmt::child_iterator TypesCompatibleExpr::child_end() {
 Stmt::child_iterator ChooseExpr::child_begin() { return &SubExprs[0]; }
 Stmt::child_iterator ChooseExpr::child_end() { return &SubExprs[0]+END_EXPR; }
 
+// GNUNullExpr
+Stmt::child_iterator GNUNullExpr::child_begin() { return child_iterator(); }
+Stmt::child_iterator GNUNullExpr::child_end() { return child_iterator(); }
+
 // OverloadExpr
 Stmt::child_iterator OverloadExpr::child_begin() { return &SubExprs[0]; }
 Stmt::child_iterator OverloadExpr::child_end() { return &SubExprs[0]+NumExprs; }