This document describes how to build and run Hermes as a standalone compiler and VM. To use Hermes in the context of a React Native app, see the React Native documentation.
The Hermes REPL will also use libreadline, if available.
To install dependencies on Ubuntu:
On Arch Linux:
On Mac via Homebrew:
Hermes will place its build files in the current directory by default.
You can also give explicit source and build directories, use
--help on the build scripts to see how.
Create a base directory to work in, e.g.
~/workspace, and cd into it.
(Tip: avoid naming it
hermes will be one of several subdirectories in the workspace).
cding, follow the steps below to generate the Hermes build system:
The build system has now been generated in the
build directory. To perform the build:
The above instructions create an unoptimized debug build. The
--distribute flag will enable a release build, in the
build_release directory. Example:
The Windows build depends on which particular combination of GitBash/Cygwin/WSL and Visual Studio is used.
The primary binary is the
hermes tool, which will be found at
To run the Hermes test suite:
To automatically format all your changes, you will need
In addition to
hermes, the following tools will be built:
hbcdump: Hermes bytecode disassembler
hvm: Standalone Hermes VM. This can execute Hermes bytecode, but does not support compiling it.