zflecs wasm32-emscripten target

[dynnamitt]

I tried:

$ cd libs/zflecs
$ zig build test -Dtarget=wasm32-emscripten --sysroot $HOME/code/emsdk/upstream/

zig build-lib zflecs Debug wasm32-emscripten: error: error(compilation): clang failed with stderr: In file included from /home/kdm/code/zig/uber-graphen/zflecs/libs/flecs/flecs.c:19:
/home/kdm/code/zig/uber-graphen/zflecs/libs/flecs/flecs.h:580:10: fatal error: 'assert.h' file not found

zig build-lib zflecs Debug wasm32-emscripten: error: the following command failed with 1 compilation errors:
/snap/zig/8241/zig build-lib -cflags -fno-sanitize=undefined -DFLECS_NO_CPP -DFLECS_USE_OS_ALLOC -DFLECS_SANITIZE -- /home/kdm/code/zig/uber-graphen/zflecs/libs/flecs/flecs.c -lc --cache-dir /home/kdm/code/zig/uber-graphen/zflecs/zig-cache --global-cache-dir /home/kdm/.cache/zig --name zflecs -static -target wasm32-emscripten -mcpu generic -I /home/kdm/code/zig/uber-graphen/zflecs/libs/flecs --sysroot /home/kdm/code/emsdk/upstream/ --listen=- 
Build Summary: 0/4 steps succeeded; 1 failed (disable with --summary none)
test transitive failure
└─ run zflecs-tests transitive failure
   └─ zig test zflecs-tests Debug wasm32-emscripten transitive failure
      └─ zig build-lib zflecs Debug wasm32-emscripten 1 errors
/home/kdm/code/zig/uber-graphen/zflecs/libs/flecs/flecs.c:1:1: error: unable to build C object: clang exited with code 1

Has anyone tried wasm building on this lib alone ?

Others solving this:

1. https://www.reddit.com/r/Zig/comments/sdcafd/zig_emscripten/
2. Emscripten support: wasm & webgpu in browser #309 (still open, and far too complex for me)
3. https://github.com/bluesillybeard/ZigAndRaylibSetup
4. Building for WebAssembly Not-Nik/raylib-zig#24

[hazeycode]

I think your sysroot path is wrong, it should be something like --sysroot path/to/emsdk/upstream/emscripten/cache/sysroot

Also some changes to zflecs build.zig would be required to build flecs C lib for emscripten using zig cc. You could try the following additions:

zflecs_c_cpp.defineCMacro("__EMSCRIPTEN__", "1");
zflecs_c_cpp.addIncludePath(.{
    .path = try std.fs.path.join(b.allocator, &.{ b.sysroot.?, "include" }),
});

Note: I haven't tried this myself

[hazeycode]

Relevant info: #309 (comment)