src/librustc_target/spec/wasm32_unknown_emscripten.rs

use super::{LinkArgs, LinkerFlavor, Target, TargetOptions};

pub fn target() -> Result<Target, String> {
    // FIXME(nikic) BINARYEN_TRAP_MODE=clamp is needed to avoid trapping in our
    // -Zsaturating-float-casts implementation. This can be dropped if/when
    // we have native fpto[su]i.sat intrinsics, or the implementation otherwise
    // stops relying on non-trapping fpto[su]i.
    let mut post_link_args = LinkArgs::new();
    post_link_args.insert(LinkerFlavor::Em,
                          vec!["-s".to_string(),
                               "BINARYEN=1".to_string(),
                               "-s".to_string(),
                               "ERROR_ON_UNDEFINED_SYMBOLS=1".to_string(),
                               "-s".to_string(),
                               "BINARYEN_TRAP_MODE='clamp'".to_string()]);

    let opts = TargetOptions {
        dynamic_linking: false,
        executables: true,
        // Today emcc emits two files - a .js file to bootstrap and
        // possibly interpret the wasm, and a .wasm file
        exe_suffix: ".js".to_string(),
        linker_is_gnu: true,
        allow_asm: false,
        obj_is_bitcode: true,
        is_like_emscripten: true,
        max_atomic_width: Some(32),
        post_link_args,
        target_family: Some("unix".to_string()),
        codegen_backend: "emscripten".to_string(),
        .. Default::default()
    };
    Ok(Target {
        llvm_target: "asmjs-unknown-emscripten".to_string(),
        target_endian: "little".to_string(),
        target_pointer_width: "32".to_string(),
        target_c_int_width: "32".to_string(),
        target_os: "emscripten".to_string(),
        target_env: String::new(),
        target_vendor: "unknown".to_string(),
        data_layout: "e-p:32:32-i64:64-v128:32:128-n32-S128".to_string(),
        arch: "wasm32".to_string(),
        linker_flavor: LinkerFlavor::Em,
        options: opts,
    })
}