wasmer/lib/emscripten/src/env/windows/mod.rs

/// NOTE: These syscalls only support wasm_32 for now because they take u32 offset
use libc::{c_int, c_long, getenv};

use std::ffi::CString;
use std::mem;
use std::os::raw::c_char;

use crate::env::call_malloc;
use crate::utils::{copy_cstr_into_wasm, read_string_from_wasm};
use wasmer_runtime_core::vm::Ctx;

extern "C" {
    #[link_name = "_putenv"]
    pub fn putenv(s: *const c_char) -> c_int;
}

// #[no_mangle]
/// emscripten: _getenv // (name: *const char) -> *const c_char;
pub fn _getenv(ctx: &mut Ctx, name: u32) -> u32 {
    debug!("emscripten::_getenv");
    let name_string = read_string_from_wasm(ctx.memory(0), name);
    debug!("=> name({:?})", name_string);
    let c_str = unsafe { getenv(name_string.as_ptr() as *const libc::c_char) };
    if c_str.is_null() {
        return 0;
    }
    unsafe { copy_cstr_into_wasm(ctx, c_str as *const c_char) }
}

/// emscripten: _setenv // (name: *const char, name: *const value, overwrite: int);
pub fn _setenv(ctx: &mut Ctx, name: u32, value: u32, _overwrite: u32) -> c_int {
    debug!("emscripten::_setenv");
    // setenv does not exist on windows, so we hack it with _putenv
    let name = read_string_from_wasm(ctx.memory(0), name);
    let value = read_string_from_wasm(ctx.memory(0), value);
    let putenv_string = format!("{}={}", name, value);
    let putenv_cstring = CString::new(putenv_string).unwrap();
    let putenv_raw_ptr = putenv_cstring.as_ptr();
    debug!("=> name({:?})", name);
    debug!("=> value({:?})", value);
    unsafe { putenv(putenv_raw_ptr) }
}

/// emscripten: _putenv // (name: *const char);
pub fn _putenv(ctx: &mut Ctx, name: c_int) -> c_int {
    debug!("emscripten::_putenv");
    let name_addr = emscripten_memory_pointer!(ctx.memory(0), name) as *const c_char;
    debug!("=> name({:?})", unsafe {
        std::ffi::CStr::from_ptr(name_addr)
    });
    unsafe { putenv(name_addr) }
}

/// emscripten: _unsetenv // (name: *const char);
pub fn _unsetenv(ctx: &mut Ctx, name: u32) -> c_int {
    debug!("emscripten::_unsetenv");
    let name = read_string_from_wasm(ctx.memory(0), name);
    // no unsetenv on windows, so use putenv with an empty value
    let unsetenv_string = format!("{}=", name);
    let unsetenv_cstring = CString::new(unsetenv_string).unwrap();
    let unsetenv_raw_ptr = unsetenv_cstring.as_ptr();
    debug!("=> name({:?})", name);
    unsafe { putenv(unsetenv_raw_ptr) }
}

#[allow(clippy::cast_ptr_alignment)]
pub fn _getpwnam(ctx: &mut Ctx, name_ptr: c_int) -> c_int {
    debug!("emscripten::_getpwnam {}", name_ptr);
    #[cfg(not(feature = "debug"))]
    let _ = name_ptr;

    #[repr(C)]
    struct GuestPasswd {
        pw_name: u32,
        pw_passwd: u32,
        pw_uid: u32,
        pw_gid: u32,
        pw_gecos: u32,
        pw_dir: u32,
        pw_shell: u32,
    }

    // stub this in windows as it is not valid
    unsafe {
        let passwd_struct_offset = call_malloc(ctx, mem::size_of::<GuestPasswd>() as _);
        let passwd_struct_ptr =
            emscripten_memory_pointer!(ctx.memory(0), passwd_struct_offset) as *mut GuestPasswd;
        (*passwd_struct_ptr).pw_name = 0;
        (*passwd_struct_ptr).pw_passwd = 0;
        (*passwd_struct_ptr).pw_gecos = 0;
        (*passwd_struct_ptr).pw_dir = 0;
        (*passwd_struct_ptr).pw_shell = 0;
        (*passwd_struct_ptr).pw_uid = 0;
        (*passwd_struct_ptr).pw_gid = 0;

        passwd_struct_offset as c_int
    }
}

#[allow(clippy::cast_ptr_alignment)]
pub fn _getgrnam(ctx: &mut Ctx, name_ptr: c_int) -> c_int {
    debug!("emscripten::_getgrnam {}", name_ptr);
    #[cfg(not(feature = "debug"))]
    let _ = name_ptr;

    #[repr(C)]
    struct GuestGroup {
        gr_name: u32,
        gr_passwd: u32,
        gr_gid: u32,
        gr_mem: u32,
    }

    // stub the group struct as it is not supported on windows
    unsafe {
        let group_struct_offset = call_malloc(ctx, mem::size_of::<GuestGroup>() as _);
        let group_struct_ptr =
            emscripten_memory_pointer!(ctx.memory(0), group_struct_offset) as *mut GuestGroup;
        (*group_struct_ptr).gr_name = 0;
        (*group_struct_ptr).gr_passwd = 0;
        (*group_struct_ptr).gr_gid = 0;
        (*group_struct_ptr).gr_mem = 0;
        group_struct_offset as c_int
    }
}

pub fn _sysconf(_ctx: &mut Ctx, name: c_int) -> c_long {
    debug!("emscripten::_sysconf {}", name);
    #[cfg(not(feature = "debug"))]
    let _ = name;
    // stub because sysconf is not valid on windows
    0
}