[builtins] Move StringNormalize to a cpp builtin.

src/builtins/builtins-string.cc

Index: src/builtins/builtins-string.cc
diff --git a/src/builtins/builtins-string.cc b/src/builtins/builtins-string.cc
index d38f6b069d50f5e751d7dfb3147f602a25b2d4f6..612b70a9c696977ee95f70ad0dd5d01fb2bded40 100644
--- a/src/builtins/builtins-string.cc
+++ b/src/builtins/builtins-string.cc
@@ -477,6 +477,37 @@ void Builtins::Generate_StringPrototypeCharCodeAt(
   assembler->Return(result);
 }
 
+// ECMA-262 v6, section 21.1.3.12 String.prototype.normalize ( [form] )
+//
+// For now we do nothing, as proper normalization requires big tables.
+// If Intl is enabled, then i18n.js will override it and provide the the
+// proper functionality.
+BUILTIN(StringPrototypeNormalize) {
+  HandleScope handle_scope(isolate);
+  TO_THIS_STRING(string, "String.prototype.trim");

[Franzi, 2016/09/09 12:51:04]

trim?

+
+  Handle<String> form;
+
+  if (args.atOrUndefined(isolate, 1)->IsUndefined(isolate)) {
+    return *string;
+  }
+  MaybeHandle<String> maybe_form(Object::ToString(isolate, args.at<Object>(1)));

[Benedikt Meurer, 2016/09/08 04:41:30]

This is not correct, as the ToString can throw and thus the MaybeHandle may be
null, and form would also be null then. You need to use soemthing along the
lines of

Handle<Object> form = args.atOrUndefined(isolate, 1);
if (form->IsUndefined(isolate)) return *string;
Handle<String> form_string;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, form_string,
Object::ToString(isolate, form));

[petermarshall, 2016/09/09 11:41:07]

Done.

+  maybe_form.ToHandle(&form);
+
+  if (!(form->Equals(*isolate->factory()->NewStringFromStaticChars("NFC")) ||
+        form->Equals(*isolate->factory()->NewStringFromStaticChars("NFD")) ||
+        form->Equals(*isolate->factory()->NewStringFromStaticChars("NFKC")) ||
+        form->Equals(*isolate->factory()->NewStringFromStaticChars("NFKD")))) {
+    Handle<String> validForms =
+        isolate->factory()->NewStringFromStaticChars("NFC, NFD, NFKC, NFKD");
+    THROW_NEW_ERROR_RETURN_FAILURE(
+        isolate,
+        NewRangeError(MessageTemplate::kNormalizationForm, validForms));
+  }
+
+  return *string;
+}
+
 // ES6 section 21.1.3.25 String.prototype.toString ()
 void Builtins::Generate_StringPrototypeToString(CodeStubAssembler* assembler) {
   typedef compiler::Node Node;