i18n support

V8 optionally implements the ECMAScript 402 specification. The API is enabled by default, but can be turned off at compile time.

Prerequisites #

The i18n implementation adds a dependency on ICU. As of v7.2, V8 requires at least ICU version 63. The exact dependency is specified in V8’s DEPS file.

Run the following command to check out a suitable version of ICU into third_party/icu:

gclient sync

See “staying up to date” for more details.

Alternative ICU checkout #

You can check out the ICU sources at a different location and define the gyp variable icu_gyp_path to point at the icu.gyp file.

System ICU #

Last but not least, you can compile V8 against a version of ICU installed in your system. To do so, specify the GYP variable use_system_icu=1. If you also have want_separate_host_toolset enabled, the bundled ICU is still compiled to generate the V8 snapshot. The system ICU is only used for the target architecture.

Embedding V8 #

If you embed V8 in your application, but your application itself doesn’t use ICU, you need to initialize ICU before calling into V8 by executing:


It is safe to invoke this method if ICU was not compiled in, then it does nothing.

Compiling without i18n support #

To build V8 without i18n support, use gn args to set v8_enable_i18n_support = false before compiling.