# ArkCompiler JS Runtime

### Introduction

ArkCompiler JS Runtime is the default JS runtime on OpenHarmony. It supports ECMAScript libraries and efficient container libraries. It also provides a set of native APIs for C++ and JS interaction and a variety of garbage collectors that features high performance.

For more information, see [ArkCompiler JS Runtime](https://gitee.com/openharmony/docs/blob/master/en/readme/ARK-Runtime-Subsystem.md).

**ArkCompiler JS Runtime architecture**

![](/docs/figures/en-us_image_ark-js-arch.png)

## Directory Structure

```
/arkcompiler/ets_runtime
├─ ecmascript             # Implementation of ArkCompiler JS Runtime, including the ECMAScript library, interpreter, and memory management
│   ├─ base               # Base helper class
│   ├─ builtins           # ECMAScript libraries
│   ├─ compiler           # JS compiler
│   ├─ containers         # Non-ECMAScript containers
│   ├─ dfx                # Memory and profiling tool
│   ├─ ic                 # Inline cache module
│   ├─ interpreter        # JS interpreter
│   ├─ jobs               # Queue of jobs
│   ├─ js_vm              # Command line tool
│   ├─ jspandafile        # abc file management module
│   ├─ mem                # Memory management module
│   ├─ module             # ECMAScript module
│   ├─ napi               # C++ API module
│   ├─ taskpool           # Task pool
│   ├─ regexp             # Regular expression engine module
│   ├─ snapshot           # Snapshot module
│   ├─ stubs              # Runtime stub functions
│   ├─ tests              # Unit test cases
│   ├─ debugger           # JS debugger
│   ├─ trampoline         # Trampoline function
│   ├─ ts_type            # TS type management module
└─ test                   # Module test cases    
```

## Constraints

* Only the ArkCompiler bytecode files generated by ts2abc, which is the ArkCompiler JS frontend toolchain, can be run.
* Only the ES2021 standard and strict modes are supported.
* Functions cannot be dynamically created using strings, such as new Function("console.log(1);")).

## Building

```
$./build.sh --product-name hispark_taurus_standard --build-target ark_js_host_linux_tools_packages
```

### Available APIs

See [NAPI](https://gitee.com/openharmony/ace_napi/blob/master/README.md).

### Usage

For details about how to generate JS bytecodes, see [Using the Toolchain](docs/using-the-toolchain.md).

To run bytecodes: 
```
LD_LIBRARY_PATH=out/hispark_taurus/clang_x64/arkcompiler/ets_runtime:out/hispark_taurus/clang_x64/thirdparty/icu:prebuilts/clang/ohos/linux-x86_64/llvm/lib ./out/hispark_taurus/clang_x64/arkcompiler/ets_runtime/ark_js_vm helloworld.abc

```

For more information, see [ARK Runtime Usage Guide](https://gitee.com/openharmony/arkcompiler_ets_runtime/blob/master/
docs/ARK-Runtime-Usage-Guide.md).

## Repositories Involved

[arkcompiler\_runtime\_core](https://gitee.com/openharmony/arkcompiler_runtime_core)

**[arkcompiler\_ets\_runtime](https://gitee.com/openharmony/arkcompiler_ets_runtime)**

[arkcompiler\_ets\_frontend](https://gitee.com/openharmony/arkcompiler_ets_frontend)