#![allow(missing_docs)]
use std::env;
use std::ffi::{CString, OsString};
use std::mem;
use std::path::{Path, PathBuf};
pub struct DynamicLibrary {
handle: *mut u8
}
impl Drop for DynamicLibrary {
fn drop(&mut self) {
match dl::check_for_errors_in(|| {
unsafe {
dl::close(self.handle)
}
}) {
Ok(()) => {},
Err(str) => panic!("{}", str)
}
}
}
impl DynamicLibrary {
pub fn open(filename: Option<&Path>) -> Result<DynamicLibrary, String> {
let maybe_library = dl::open(filename.map(|path| path.as_os_str()));
match maybe_library {
Err(err) => Err(err),
Ok(handle) => Ok(DynamicLibrary { handle: handle })
}
}
pub fn prepend_search_path(path: &Path) {
let mut search_path = DynamicLibrary::search_path();
search_path.insert(0, path.to_path_buf());
env::set_var(DynamicLibrary::envvar(), &DynamicLibrary::create_path(&search_path));
}
pub fn create_path(path: &[PathBuf]) -> OsString {
let mut newvar = OsString::new();
for (i, path) in path.iter().enumerate() {
if i > 0 { newvar.push(DynamicLibrary::separator()); }
newvar.push(path);
}
return newvar;
}
pub fn envvar() -> &'static str {
if cfg!(windows) {
"PATH"
} else if cfg!(target_os = "macos") {
"DYLD_LIBRARY_PATH"
} else {
"LD_LIBRARY_PATH"
}
}
fn separator() -> &'static str {
if cfg!(windows) { ";" } else { ":" }
}
pub fn search_path() -> Vec<PathBuf> {
match env::var_os(DynamicLibrary::envvar()) {
Some(var) => env::split_paths(&var).collect(),
None => Vec::new(),
}
}
pub unsafe fn symbol<T>(&self, symbol: &str) -> Result<*mut T, String> {
let raw_string = CString::new(symbol).unwrap();
let maybe_symbol_value = dl::check_for_errors_in(|| {
dl::symbol(self.handle, raw_string.as_ptr())
});
match maybe_symbol_value {
Err(err) => Err(err),
Ok(symbol_value) => Ok(mem::transmute(symbol_value))
}
}
}
#[cfg(all(test, not(target_os = "ios")))]
mod test {
use super::*;
use libc;
use std::mem;
use std::path::Path;
#[test]
#[cfg_attr(any(windows, target_os = "android"), ignore)] fn test_loading_cosine() {
let libm = match DynamicLibrary::open(None) {
Err(error) => panic!("Could not load self as module: {}", error),
Ok(libm) => libm
};
let cosine: extern fn(libc::c_double) -> libc::c_double = unsafe {
match libm.symbol("cos") {
Err(error) => panic!("Could not load function cos: {}", error),
Ok(cosine) => mem::transmute::<*mut u8, _>(cosine)
}
};
let argument = 0.0;
let expected_result = 1.0;
let result = cosine(argument);
if result != expected_result {
panic!("cos({}) != {} but equaled {} instead", argument,
expected_result, result)
}
}
#[test]
#[cfg(any(target_os = "linux",
target_os = "macos",
target_os = "freebsd",
target_os = "dragonfly",
target_os = "bitrig",
target_os = "openbsd"))]
fn test_errors_do_not_crash() {
let path = Path::new("/dev/null");
match DynamicLibrary::open(Some(&path)) {
Err(_) => {}
Ok(_) => panic!("Successfully opened the empty library.")
}
}
}
#[cfg(any(target_os = "linux",
target_os = "android",
target_os = "macos",
target_os = "ios",
target_os = "freebsd",
target_os = "dragonfly",
target_os = "bitrig",
target_os = "openbsd"))]
mod dl {
use std::ffi::{CString, CStr, OsStr};
use std::os::unix::ffi::OsStrExt;
use std::str;
use libc;
use std::ptr;
use std::sync::Mutex;
lazy_static! {
static ref LOCK: Mutex<()> = Mutex::new(());
}
pub fn open(filename: Option<&OsStr>) -> Result<*mut u8, String> {
check_for_errors_in(|| {
unsafe {
match filename {
Some(filename) => open_external(filename),
None => open_internal(),
}
}
})
}
const LAZY: libc::c_int = 1;
unsafe fn open_external(filename: &OsStr) -> *mut u8 {
let s = CString::new(filename.as_bytes().to_vec()).unwrap();
dlopen(s.as_ptr(), LAZY) as *mut u8
}
unsafe fn open_internal() -> *mut u8 {
dlopen(ptr::null(), LAZY) as *mut u8
}
pub fn check_for_errors_in<T, F>(f: F) -> Result<T, String> where
F: FnOnce() -> T,
{
unsafe {
let _guard = LOCK.lock();
let _old_error = dlerror();
let result = f();
let last_error = dlerror() as *const _;
let ret = if ptr::null() == last_error {
Ok(result)
} else {
let s = CStr::from_ptr(last_error).to_bytes();
Err(str::from_utf8(s).unwrap().to_string())
};
ret
}
}
pub unsafe fn symbol(handle: *mut u8,
symbol: *const libc::c_char) -> *mut u8 {
dlsym(handle as *mut libc::c_void, symbol) as *mut u8
}
pub unsafe fn close(handle: *mut u8) {
dlclose(handle as *mut libc::c_void); ()
}
extern {
fn dlopen(filename: *const libc::c_char,
flag: libc::c_int) -> *mut libc::c_void;
fn dlerror() -> *mut libc::c_char;
fn dlsym(handle: *mut libc::c_void,
symbol: *const libc::c_char) -> *mut libc::c_void;
fn dlclose(handle: *mut libc::c_void) -> libc::c_int;
}
}
#[cfg(target_os = "windows")]
mod dl {
use std::ffi::OsStr;
use std::iter::Iterator;
use libc;
use std::ops::FnOnce;
use std::io::Error as IoError;
use std::os::windows::prelude::*;
use std::option::Option::{self, Some, None};
use std::ptr;
use std::result::Result;
use std::result::Result::{Ok, Err};
use std::string::String;
use std::vec::Vec;
pub fn open(filename: Option<&OsStr>) -> Result<*mut u8, String> {
let prev_error_mode = unsafe {
let new_error_mode = 1;
SetErrorMode(new_error_mode)
};
unsafe {
SetLastError(0);
}
let result = match filename {
Some(filename) => {
let filename_str: Vec<_> =
filename.encode_wide().chain(Some(0).into_iter()).collect();
let result = unsafe {
LoadLibraryW(filename_str.as_ptr() as *const libc::c_void)
};
if result == ptr::null_mut() {
Err(format!("{}", IoError::last_os_error()))
} else {
Ok(result as *mut u8)
}
}
None => {
let mut handle = ptr::null_mut();
let succeeded = unsafe {
GetModuleHandleExW(0 as libc::DWORD, ptr::null(), &mut handle)
};
if succeeded == libc::FALSE {
Err(format!("{}", IoError::last_os_error()))
} else {
Ok(handle as *mut u8)
}
}
};
unsafe {
SetErrorMode(prev_error_mode);
}
result
}
pub fn check_for_errors_in<T, F>(f: F) -> Result<T, String> where
F: FnOnce() -> T,
{
unsafe {
SetLastError(0);
let result = f();
let error = IoError::last_os_error();
if 0 == error.raw_os_error().unwrap() {
Ok(result)
} else {
Err(format!("{}", error))
}
}
}
pub unsafe fn symbol(handle: *mut u8, symbol: *const libc::c_char) -> *mut u8 {
GetProcAddress(handle as *mut libc::c_void, symbol) as *mut u8
}
pub unsafe fn close(handle: *mut u8) {
FreeLibrary(handle as *mut libc::c_void); ()
}
#[allow(non_snake_case)]
extern "system" {
fn SetLastError(error: libc::size_t);
fn LoadLibraryW(name: *const libc::c_void) -> *mut libc::c_void;
fn GetModuleHandleExW(dwFlags: libc::DWORD, name: *const u16,
handle: *mut *mut libc::c_void) -> libc::BOOL;
fn GetProcAddress(handle: *mut libc::c_void,
name: *const libc::c_char) -> *mut libc::c_void;
fn FreeLibrary(handle: *mut libc::c_void);
fn SetErrorMode(uMode: libc::c_uint) -> libc::c_uint;
}
}