clib namespace types undefined when compiling for wasm32-unknown-unknown with wasm-pack

[mattgreeley]

Bit of a newbie here... I'm not sure if this is the best place to put this... (I will probably cross post to wasm-pack, etc.)

I am trying to build rust-sdl2 v0.34.3 targeting wasm32-unknown-unknown with wasm-pack build...

But I am getting errors while compiling sdl2-sys v0.34.2...

Specifically certain types (eg. c_char) are not found in crate libc.

mac-machinename:wasm-lib-canvas mac-username$ wasm-pack build --scope clearair43
[INFO]: 🎯  Checking for the Wasm target...
[INFO]: 🌀  Compiling to Wasm...
   Compiling version-compare v0.0.10
   Compiling libc v0.2.76
   Compiling bitflags v1.2.1
   Compiling sdl2 v0.34.3
   Compiling lazy_static v1.4.0
   Compiling sdl2-sys v0.34.2   Compiling sdl2-sys v0.34.2
error[E0412]: cannot find type `c_char` in crate `libc`
   --> /Users/mac-username/repos/wasm-lib-canvas/target/wasm32-unknown-unknown/release/build/sdl2-sys-6a1b51b03ef58e2a/out/sdl_bindings.rs:917:46
    |
917 |     pub fn SDL_GetPlatform() -> *const libc::c_char;
    |                                              ^^^^^^ not found in `libc`

error[E0412]: cannot find type `c_ulong` in crate `libc`
   --> /Users/mac-username/repos/wasm-lib-canvas/target/wasm32-unknown-unknown/release/build/sdl2-sys-6a1b51b03ef58e2a/out/sdl_bindings.rs:919:25
    |
919 | pub type size_t = libc::c_ulong;
    |                         ^^^^^^^ not found in `libc`

error[E0412]: cannot find type `c_int` in crate `libc`
   --> /Users/mac-username/repos/wasm-lib-canvas/target/wasm32-unknown-unknown/release/build/sdl2-sys-6a1b51b03ef58e2a/out/sdl_bindings.rs:920:26
    |
920 | pub type wchar_t = libc::c_int;
    |                          ^^^^^ not found in `libc`

What have I tried to solve on my own?

Found this similar issue: rust-ndarray/ndarray-linalg#121

• "it looks like the libc crate doesn't define c_char, ...etc."
• https://github.com/rust-lang/libc/blob/5cc006652a242c35b6fe5b615ccd39d9356a2346/src/lib.rs#L128

Which links to this issue...sfackler/rust-openssl#1016 ... with these comments..

• "For the wasm target it's still an open question how Rust and C code interoperate."
• "for now we’d recommend using all-rust solutions (if they exist) fro the wasm32-unknown-unknown case..."
• "To be clear this likely has a path forwar to working with the {asmjs, wasm32}-unknown-emscripten targets..."

Found this repo but it looks like it relies on emscripten

• https://github.com/tanis2000/rust-sdl2-wasm
• Code using SDL 2.0 will not compile to WASM emscripten-core/emscripten#5097

My Specific Questions...

• Is Rust+SDL2==>WASM a non-starter today due to clib issues?
• Is the best path to 'fall back' to emscripten?
• Any other pointers because I am feeling pretty blocked?

[felipellrocha]

any luck here? Ran into the same issue today

[EriKWDev]

Still not resolved. Any reason libc::c_int is used over core::ffi::c_int?

I see in the build.rs for sdl-sys it is explicitly requested that libc be used