/rules_emscripten

Bazel rules for building C/C++ code into Javascript using the Emscripten toolset.

Primary LanguageStarlark

com_stevenengelhardt_rules_emscripten

Bazel rules for building C/C++ code into Javascript using the Emscripten toolset. Supports builds on Linux, OS X, and Windows.

Build Status

ci nightly release

Table of Contents

Quick Start Guide

Add the following stanza to WORKSPACE:

http_archive(
    name = "com_stevenengelhardt_rules_emscripten",
    sha256 = "d4e2f81085f27579609411c97989bb586f7b9ae0c555345a0617c96b7d1aa47e",
    urls = ["https://github.com/sengelha/rules_emscripten/releases/download/v1.5.2/rules_emscripten-1.5.2.zip"],
)

load("@com_stevenengelhardt_rules_emscripten//emscripten:deps.bzl", "emscripten_rules_dependencies", "emscripten_setup")
emscripten_rules_dependencies()
emscripten_setup()

Add the following stanza to BUILD, adjusting as needed:

load("@com_stevenengelhardt_rules_emscripten//emscripten:def.bzl", "emcc_binary")

emcc_binary(
    name = "hello_world",
    srcs = ["main.cpp"],
)

For more examples, see examples.

Repository Rules

emscripten_setup

Setup up com_stevenengelhardt_rules_emscripten, including registering appropriate toolchains.

emscripten_setup(version)

Attributes

Attribute Name Type Required? Description
version String optional The version of Emscripten to use. Set to host to use the emscripten SDK installed on the host machine. Defaults to the latest supported Emscripten SDK.

Build Rules

emcc_binary

Compiles a set of C/C++ files into a JavaScript "binary" (a .js and a .wasm file) and allows it be executed via bazel run.

Attributes

Attribute Name Type Required? Description
name Name required A unique name for this rule.
srcs List of files required A list of source files required to compile the binary.
emit_wasm Boolean Optional Whether to emit a WASM file as part of the build. Default = True.
emit_memory_init_file Boolean Optional Whether to emit a memory init file. Only applies if emit_wasm = False. Default = True.
configuration String optional The build configuration for the target (dbg, opt, or fastbuild). If not specified, uses the global -c option value.

emcc_module

Compiles a set of C/C++ files into a JavaScript module (a .js and a .wasm file).

Attributes

Attribute Name Type Required? Description
name Name required A unique name for this rule.
srcs List of files required A list of source files required to compile the module.
modularize Boolean optional Whether to output a JS module, as in the emcc -s MODULARIZE=1 option. Default = True.
emit_wasm Boolean Optional Whether to emit a WASM file as part of the build. Default = True.
emit_memory_init_file Boolean Optional Whether to emit a memory init file. Only applies if emit_wasm = False. Default = True.
pre_js File optional A JavaScript file to prepend to the output using emcc's --pre-js option.
post_js File optional A JavaScript file to append to the output using emcc's --post-js option.
extern_pre_js File optional A JavaScript file to prepend to the output using emcc's --extern-pre-js option.
extern_post_js File optional A JavaScript file to append to the output using emcc's --extern-post-js option.
linkopts List of strings optional Additional flags to add to emcc at link time
configuration String optional The build configuration for the target (dbg, opt, or fastbuild). If not specified, uses the global -c option value.