module dl

pub const version = 1

pub const dl_ext = get_shared_library_extension()

pub const rtld_next = voidptr(-1)

// get_shared_library_extension returns the platform dependent shared library extension
// i.e. .dll on windows, .so on most unixes, .dylib on macos.
[inline]
pub fn get_shared_library_extension() string {
    return $if windows {
        '.dll'
    } $else $if macos {
        '.dylib'
    } $else {
        '.so'
    }
}

// get_libname returns a library name with the operating system specific extension for
// shared libraries.
[inline]
pub fn get_libname(libname string) string {
    return '${libname}${dl.dl_ext}'
}

// open_opt tries to load a given dynamic shared object.
pub fn open_opt(filename string, flags int) !voidptr {
    shared_object_handle := open(filename, flags)
    if shared_object_handle == 0 {
        e := dlerror()
        return error(e)
    }
    return shared_object_handle
}

// sym_opt returns the address of a symbol in a given shared object, if found.
// Unlike sym, sym_opt returns an option.
pub fn sym_opt(shared_object_handle voidptr, symbol string) !voidptr {
    sym_handle := sym(shared_object_handle, symbol)
    if sym_handle == 0 {
        e := dlerror()
        return error(e)
    }
    return sym_handle
}