Questions: is there any ways to compile to wasm with emscripten?

[lee88688]

I want to simulate some code with jerryscript using wasm through emscripten. but I found build options without config for emscripten. so there is any ideas to build with emscripten?

[akosthekiss]

Quite some time ago (in 2016, yikes!), I managed to build JerryScript for emscripten. Here are the notes from those days:

Environment:

• OS X 10.11.6 (Darwin 15.6.0)
• Emscripten 1.35.0 with Node.js v4.1.1 (from: http://kripken.github.io/emscripten-site/docs/getting_started/downloads.html)
• JerryScript commit 9915307 (Tue Oct 4 11:51:03 2016 +0200)

Commands:

cmake -H. -Bbuild -DJERRY_LIBC=OFF -DJERRY_LIBM=OFF -DCMAKE_C_COMPILER=emcc -DENABLE_LTO=OFF -DENABLE_ALL_IN_ONE=ON -DENABLE_STRIP=OFF -DCMAKE_EXECUTABLE_SUFFIX_C=.js
make -C build
cd build/bin && cat ../../tests/hello.js | node jerry.js --no-prompt

Note:

• Only REPL works. Passing JS files as arguments (e.g., node jerry.js ../../tests/hello.js) fails with "Error: failed to open file".

Since then, quite some things have changed: sources, build system, emcc, node, ... The above will not work out of the box for sure. I'd start the experiment with the following build configuration:

rm -rf build/
cmake -H. -Bbuild -DCMAKE_C_COMPILER=emcc -DENABLE_LTO=OFF -DENABLE_AMALGAM=ON -DENABLE_STRIP=OFF -DCMAKE_EXECUTABLE_SUFFIX_C=.js
make -C build VERBOSE=1

The above commands get me quite far, but linking fails as I don't have emsdk installed, and the Ubuntu-provided emcc has llvm triplet issues. I hope that someone can pick it up from here.

[lee88688]

there is any way to make a toolchain to build? I make a toolchain file and config in command line in build.py, but when I build, it always use windows build tools, here is my toolchain code

set(CMAKE_SYSTEM_NAME emscripten)
set(CMAKE_SYSTEM_PROCESSOR wasm)

set(CMAKE_C_COMPILER emcc)

[lee88688]

and I found any other toolchain in windows don't work either。

[akosthekiss]

More details are needed to find the root of the problem. How did you invoke build.py? What was the output?

Moreover, finding the correct configuration options for an emscripten build is independent from using a toolchain file. So, I suggest to try and configure cmake directly and when the build finally works, move the cmake command line options into a toolchain file.

[lee88688]

currently I can successfully use emscripten sdk to build lib, here is my code

emcmake cmake -Bbuild -DJERRY_DEBUGGER=ON -DJERRY_LINE_INFO=ON  -DJERRY_CPOINTER_32_BIT=ON -DJERRY_SYSTEM_ALLOCATOR=ON
emmake make -C build

but I have not tested yet.