[api] add v8::Isolate::GetDefaultLocale()

joyeecheung · V8 LUCI CQ · commit e74d0f437fcd · 2024-08-16T18:50:46.000Z
This allows embedders to query the default locale used by Intl APIs. This information is already available to user land via Intl?.Collator().resolvedOptions().locale, the issue with this is that it's a lot slower and requires dynamic access to Intl API, which is subject to patching and prototype pollution so it's not as reliable for embedders than having a V8 API to query the default locale directly. Refs: nodejs/node#54279 Change-Id: I5a1823993c9ae79f8f61f54c6464daf882a09ba3 Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/5772938 Reviewed-by: Leszek Swirski <leszeks@chromium.org> Commit-Queue: Joyee Cheung <joyee@igalia.com> Cr-Commit-Position: refs/heads/main@{#95678}
diff --git a/include/v8-isolate.h b/include/v8-isolate.h
@@ -9,6 +9,7 @@
 #include <stdint.h>
 
 #include <memory>
+#include <string>
 #include <utility>
 
 #include "cppgc/common.h"
@@ -1723,6 +1724,12 @@ class V8_EXPORT Isolate {
    */
   void LocaleConfigurationChangeNotification();
 
+  /**
+   * Returns the default locale in a string if Intl support is enabled.
+   * Otherwise returns an empty string.
+   */
+  std::string GetDefaultLocale();
+
   Isolate() = delete;
   ~Isolate() = delete;
   Isolate(const Isolate&) = delete;
diff --git a/src/api/api.cc b/src/api/api.cc
@@ -10774,6 +10774,17 @@ void v8::Isolate::LocaleConfigurationChangeNotification() {
 #endif  // V8_INTL_SUPPORT
 }
 
+std::string Isolate::GetDefaultLocale() {
+  i::Isolate* i_isolate = reinterpret_cast<i::Isolate*>(this);
+  ENTER_V8_NO_SCRIPT_NO_EXCEPTION(i_isolate);
+
+#ifdef V8_INTL_SUPPORT
+  return i_isolate->DefaultLocale();
+#else
+  return std::string();
+#endif
+}
+
 #if defined(V8_OS_WIN) && defined(V8_ENABLE_ETW_STACK_WALKING)
 void Isolate::SetFilterETWSessionByURLCallback(
     FilterETWSessionByURLCallback callback) {
