1 // Copyright 2013-2015 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Dynamic library facilities.
13 //! A simple wrapper over the platform's dynamic library facilities
15 #![unstable(feature = "dynamic_lib",
16 reason
= "API has not been scrutinized and is highly likely to \
17 either disappear or change",
19 #![allow(missing_docs)]
25 use ffi
::{CString, OsString}
;
26 use path
::{Path, PathBuf}
;
28 #[unstable(feature = "dynamic_lib",
29 reason
= "API has not been scrutinized and is highly likely to \
30 either disappear or change",
32 #[rustc_deprecated(since = "1.5.0", reason = "replaced with 'dylib' on crates.io")]
33 pub struct DynamicLibrary
{
37 impl Drop
for DynamicLibrary
{
39 match dl
::check_for_errors_in(|| {
41 dl
::close(self.handle
)
45 Err(str) => panic
!("{}", str)
50 #[unstable(feature = "dynamic_lib",
51 reason
= "API has not been scrutinized and is highly likely to \
52 either disappear or change",
54 #[rustc_deprecated(since = "1.5.0", reason = "replaced with 'dylib' on crates.io")]
56 /// Lazily open a dynamic library. When passed None it gives a
57 /// handle to the calling process
58 pub fn open(filename
: Option
<&Path
>) -> Result
<DynamicLibrary
, String
> {
59 let maybe_library
= dl
::open(filename
.map(|path
| path
.as_os_str()));
61 // The dynamic library must not be constructed if there is
62 // an error opening the library so the destructor does not
66 Ok(handle
) => Ok(DynamicLibrary { handle: handle }
)
70 /// Prepends a path to this process's search path for dynamic libraries
71 pub fn prepend_search_path(path
: &Path
) {
72 let mut search_path
= DynamicLibrary
::search_path();
73 search_path
.insert(0, path
.to_path_buf());
74 env
::set_var(DynamicLibrary
::envvar(), &DynamicLibrary
::create_path(&search_path
));
77 /// From a slice of paths, create a new vector which is suitable to be an
78 /// environment variable for this platforms dylib search path.
79 pub fn create_path(path
: &[PathBuf
]) -> OsString
{
80 let mut newvar
= OsString
::new();
81 for (i
, path
) in path
.iter().enumerate() {
82 if i
> 0 { newvar.push(DynamicLibrary::separator()); }
88 /// Returns the environment variable for this process's dynamic library
90 pub fn envvar() -> &'
static str {
93 } else if cfg
!(target_os
= "macos") {
100 fn separator() -> &'
static str {
101 if cfg
!(windows
) { ";" }
else { ":" }
104 /// Returns the current search path for dynamic libraries being used by this
106 pub fn search_path() -> Vec
<PathBuf
> {
107 match env
::var_os(DynamicLibrary
::envvar()) {
108 Some(var
) => env
::split_paths(&var
).collect(),
113 /// Accesses the value at the symbol of the dynamic library.
114 pub unsafe fn symbol
<T
>(&self, symbol
: &str) -> Result
<*mut T
, String
> {
115 // This function should have a lifetime constraint of 'a on
116 // T but that feature is still unimplemented
118 let raw_string
= CString
::new(symbol
).unwrap();
119 let maybe_symbol_value
= dl
::check_for_errors_in(|| {
120 dl
::symbol(self.handle
, raw_string
.as_ptr())
123 // The value must not be constructed if there is an error so
124 // the destructor does not run.
125 match maybe_symbol_value
{
126 Err(err
) => Err(err
),
127 Ok(symbol_value
) => Ok(symbol_value
as *mut T
)
132 #[cfg(all(test, not(target_os = "ios"), not(target_os = "nacl")))]
140 #[cfg_attr(any(windows,
141 target_os
= "android", // FIXME #10379
142 target_env
= "musl"), ignore
)]
144 fn test_loading_cosine() {
145 // The math library does not need to be loaded since it is already
146 // statically linked in
147 let libm
= match DynamicLibrary
::open(None
) {
148 Err(error
) => panic
!("Could not load self as module: {}", error
),
152 let cosine
: extern fn(libc
::c_double
) -> libc
::c_double
= unsafe {
153 match libm
.symbol("cos") {
154 Err(error
) => panic
!("Could not load function cos: {}", error
),
155 Ok(cosine
) => mem
::transmute
::<*mut u8, _
>(cosine
)
160 let expected_result
= 1.0;
161 let result
= cosine(argument
);
162 if result
!= expected_result
{
163 panic
!("cos({}) != {} but equaled {} instead", argument
,
164 expected_result
, result
)
169 #[cfg(any(target_os = "linux",
171 target_os
= "freebsd",
172 target_os
= "dragonfly",
173 target_os
= "bitrig",
174 target_os
= "netbsd",
175 target_os
= "openbsd",
176 target_os
= "solaris"))]
178 fn test_errors_do_not_crash() {
181 // Open /dev/null as a library to get an error, and make sure
182 // that only causes an error, and not a crash.
183 let path
= Path
::new("/dev/null");
184 match DynamicLibrary
::open(Some(&path
)) {
186 Ok(_
) => panic
!("Successfully opened the empty library.")
191 #[cfg(any(target_os = "linux",
192 target_os
= "android",
195 target_os
= "freebsd",
196 target_os
= "dragonfly",
197 target_os
= "bitrig",
198 target_os
= "netbsd",
199 target_os
= "openbsd",
200 target_os
= "solaris",
201 target_os
= "emscripten"))]
205 use ffi
::{CStr, OsStr}
;
210 pub fn open(filename
: Option
<&OsStr
>) -> Result
<*mut u8, String
> {
211 check_for_errors_in(|| {
214 Some(filename
) => open_external(filename
),
215 None
=> open_internal(),
221 const LAZY
: libc
::c_int
= 1;
223 unsafe fn open_external(filename
: &OsStr
) -> *mut u8 {
224 let s
= filename
.to_cstring().unwrap();
225 libc
::dlopen(s
.as_ptr(), LAZY
) as *mut u8
228 unsafe fn open_internal() -> *mut u8 {
229 libc
::dlopen(ptr
::null(), LAZY
) as *mut u8
232 pub fn check_for_errors_in
<T
, F
>(f
: F
) -> Result
<T
, String
> where
235 use sync
::StaticMutex
;
236 static LOCK
: StaticMutex
= StaticMutex
::new();
238 // dlerror isn't thread safe, so we need to lock around this entire
240 let _guard
= LOCK
.lock();
241 let _old_error
= libc
::dlerror();
245 let last_error
= libc
::dlerror() as *const _
;
246 let ret
= if ptr
::null() == last_error
{
249 let s
= CStr
::from_ptr(last_error
).to_bytes();
250 Err(str::from_utf8(s
).unwrap().to_owned())
257 pub unsafe fn symbol(handle
: *mut u8,
258 symbol
: *const libc
::c_char
) -> *mut u8 {
259 libc
::dlsym(handle
as *mut libc
::c_void
, symbol
) as *mut u8
261 pub unsafe fn close(handle
: *mut u8) {
262 libc
::dlclose(handle
as *mut libc
::c_void
); ()
266 #[cfg(target_os = "windows")]
272 use os
::windows
::prelude
::*;
277 pub fn open(filename
: Option
<&OsStr
>) -> Result
<*mut u8, String
> {
278 // disable "dll load failed" error dialog.
279 let mut use_thread_mode
= true;
280 let prev_error_mode
= unsafe {
281 // SEM_FAILCRITICALERRORS 0x01
282 let new_error_mode
= 1;
283 let mut prev_error_mode
= 0;
284 // Windows >= 7 supports thread error mode.
285 let result
= c
::SetThreadErrorMode(new_error_mode
,
286 &mut prev_error_mode
);
288 let err
= os
::errno();
289 if err
== c
::ERROR_CALL_NOT_IMPLEMENTED
as i32 {
290 use_thread_mode
= false;
291 // SetThreadErrorMode not found. use fallback solution:
292 // SetErrorMode() Note that SetErrorMode is process-wide so
293 // this can cause race condition! However, since even
294 // Windows APIs do not care of such problem (#20650), we
295 // just assume SetErrorMode race is not a great deal.
296 prev_error_mode
= c
::SetErrorMode(new_error_mode
);
306 let result
= match filename
{
308 let filename_str
: Vec
<_
> =
309 filename
.encode_wide().chain(Some(0)).collect();
310 let result
= unsafe {
311 c
::LoadLibraryW(filename_str
.as_ptr())
313 // beware: Vec/String may change errno during drop!
314 // so we get error here.
315 if result
== ptr
::null_mut() {
316 let errno
= os
::errno();
317 Err(os
::error_string(errno
))
319 Ok(result
as *mut u8)
323 let mut handle
= ptr
::null_mut();
324 let succeeded
= unsafe {
325 c
::GetModuleHandleExW(0 as c
::DWORD
, ptr
::null(),
328 if succeeded
== c
::FALSE
{
329 let errno
= os
::errno();
330 Err(os
::error_string(errno
))
332 Ok(handle
as *mut u8)
339 c
::SetThreadErrorMode(prev_error_mode
, ptr
::null_mut());
341 c
::SetErrorMode(prev_error_mode
);
348 pub fn check_for_errors_in
<T
, F
>(f
: F
) -> Result
<T
, String
> where
356 let error
= os
::errno();
360 Err(format
!("Error code {}", error
))
365 pub unsafe fn symbol(handle
: *mut u8, symbol
: *const libc
::c_char
) -> *mut u8 {
366 c
::GetProcAddress(handle
as c
::HMODULE
, symbol
) as *mut u8
368 pub unsafe fn close(handle
: *mut u8) {
369 c
::FreeLibrary(handle
as c
::HMODULE
);
373 #[cfg(target_os = "nacl")]
378 use result
::Result
::Err
;
384 pub fn open(_filename
: Option
<&OsStr
>) -> Result
<*mut u8, String
> {
385 Err(format
!("NaCl + Newlib doesn't impl loading shared objects"))
388 pub fn check_for_errors_in
<T
, F
>(_f
: F
) -> Result
<T
, String
>
389 where F
: FnOnce() -> T
,
391 Err(format
!("NaCl doesn't support shared objects"))
394 pub unsafe fn symbol(_handle
: *mut u8, _symbol
: *const libc
::c_char
) -> *mut u8 {
397 pub unsafe fn close(_handle
: *mut u8) { }