//! Initialize wasi-libc's cwd for every program that the world toolchain builds.
#![no_std]

#[used]
#[unsafe(link_section = "component-type:sausage-exit")]
static EXIT_INTERFACE: [u8; include_bytes!("exit-meta.bin").len()] =
    *include_bytes!("exit-meta.bin");

unsafe extern "C" {
    fn getenv(name: *const u8) -> *const u8;
    fn chdir(path: *const u8) -> i32;
}

#[link(wasm_import_module = "wasi:cli/exit@0.2.12")]
unsafe extern "C" {
    #[link_name = "exit-with-code"]
    fn exit_with_code(code: u32);
}

/// Replace wasi-libc's success/failure conversion with the standard numeric exit interface.
#[unsafe(no_mangle)]
unsafe extern "C" fn _Exit(code: i32) -> ! {
    unsafe {
        exit_with_code((code as u32) & 255);
    }
    core::arch::wasm32::unreachable()
}

#[unsafe(no_mangle)]
unsafe extern "C" fn _exit(code: i32) -> ! {
    unsafe { _Exit(code) }
}

extern "C" fn initialize() {
    // PWD is supplied by the process table, never inferred from a host directory.
    unsafe {
        let cwd = getenv(c"PWD".as_ptr().cast());
        if !cwd.is_null() && chdir(cwd) != 0 {
            _exit(1);
        }
    }
}

#[used]
#[unsafe(link_section = ".init_array")]
static INITIALIZE: extern "C" fn() = initialize;