- NaCL/PNaCl, asm.js: too slow
- wasm:
- fast
- all major tech companies in support
- overcomes many disadvantages of pure javascript (compilation, optimization, size, ...)
- does not matter anymore which language you pick
- still making specs based on proposals
- reports a lot of improvement on speed
- recent movements
- off-the-browser: WASI
- Photoshop, AutoCAD, Google Earth, ...
- involvement in blockchain
- danger (binary)
- advent of wasm standalone runtimes like
wasmtime
Help link: https://emscripten.org/docs/getting_started/downloads.html
# Get the emsdk repo
git clone https://github.com/emscripten-core/emsdk.git
# Enter that directory
cd emsdk
# Fetch the latest version of the emsdk (not needed the first time you clone)
git pull
# Download and install the latest SDK tools.
./emsdk install latest
# Make the "latest" SDK "active" for the current user. (writes ~/.emscripten file)
./emsdk activate latest
# Activate PATH and other environment variables in the current terminal
source ./emsdk_env.shNavigate with the command prompt to the emscripten directory under the SDK. This is a folder below the emsdk root directory, typically
<emsdk root directory>/fastcomp/emscripten/(for the older “fastcomp” compiler; for the newer upstream LLVM wasm backend it will be<emsdk root directory>/upstream/emscripten/). The examples below will depend on finding files relative to that location.
Help link: https://emscripten.org/docs/getting_started/Tutorial.html
$ cd <emsdk root directory>/upstream/emscripten/
$ ls
AUTHORS emconfigure.py
CONTRIBUTING.md emlink.py
ChangeLog.md emmake
LICENSE emmake.bat
README.md emmake.py
__pycache__ emranlib
cmake emranlib.bat
docs emrun
em++ emrun.bat
em++.bat emrun.py
em++.py emscons
em-config emscons.py
em-config.bat emscripten-version.txt
emar emscripten.py
emar.bat emscripten.pyc
emar.py media
embuilder.py package-lock.json
emcc package.json
emcc.bat site
emcc.py src
emcmake system
emcmake.bat tests
emcmake.py third_party
emconfigure tools
emconfigure.bat(base) ➜ emscripten git:(master) ./emcc -v
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 1.39.0
clang version 10.0.0 (/b/s/w/ir/cache/git/chromium.googlesource.com-external-github.com-llvm-llvm--project e44524736c4a97ae4fb37193e58647f838f6d36a)
Target: x86_64-apple-darwin18.7.0
Thread model: posix
InstalledDir: /Users/jm/Documents/Code/emsdk/upstream/bin
shared:INFO: (Emscripten: Running sanity checks)$ vim ~/.profile (or .zshrc or whatever)
... at the end of .profile, perhaps:
alias emcc="<path-to-emsdk>/upstream/emscripten/emcc"
$ source ~/.profiletouch hello-world.cpp
echo "#include <iostream>
int main() {
std::cout << "hello, world!\n";
return 0;
}" >> hello-world.cpp
$ emcc hello-world.cpp -o hello-world.js # this is going to generate
(base) ➜ tutorial git:(master) ✗ emcc hello-world.cpp
cache:INFO: generating system library: libcompiler_rt.a... (this will be cached in "/Users/jm/.emscripten_cache/wasm-obj/libcompiler_rt.a" for subsequent builds)
cache:INFO: - ok
cache:INFO: generating system library: libc-wasm.a... (this will be cached in "/Users/jm/.emscripten_cache/wasm-obj/libc-wasm.a" for subsequent builds)
cache:INFO: - ok
cache:INFO: generating system library: libc++-noexcept.a... (this will be cached in "/Users/jm/.emscripten_cache/wasm-obj/libc++-noexcept.a" for subsequent builds)
cache:INFO: - ok
cache:INFO: generating system library: libc++abi-noexcept.a... (this will be cached in "/Users/jm/.emscripten_cache/wasm-obj/libc++abi-noexcept.a" for subsequent builds)
cache:INFO: - ok
cache:INFO: generating system library: libdlmalloc.a... (this will be cached in "/Users/jm/.emscripten_cache/wasm-obj/libdlmalloc.a" for subsequent builds)
cache:INFO: - ok
cache:INFO: generating system library: libpthread_stub.a... (this will be cached in "/Users/jm/.emscripten_cache/wasm-obj/libpthread_stub.a" for subsequent builds)
cache:INFO: - ok
cache:INFO: generating system library: libc_rt_wasm.a... (this will be cached in "/Users/jm/.emscripten_cache/wasm-obj/libc_rt_wasm.a" for subsequent builds)
cache:INFO: - ok
(base) ➜ tutorial git:(master) ✗ ls tests/results
hello-world hello-world.js hello-world.wasmNow you know that emcc is working well.
npm i -g http-server
http-server --cors . # current directory should have .wasm file<html>
<head>
<script>
window.onload = () => {
const importObject = { imports: { imported_func: arg => console.log(arg) } };
WebAssembly.instantiateStreaming(fetch('localhost:8000/hello-world.wasm'), importObject)
.then(obj => obj.instance.exports.exported_func());
}
</script>
</head>
<body>
</body>
</html>npm install --save-dev assemblyscript
npx asinit .