1 // Copyright 2013 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.
13 Dynamic library facilities.
15 A simple wrapper over the platforms dynamic library facilities
26 pub struct DynamicLibrary { priv handle: *libc::c_void }
28 impl Drop for DynamicLibrary {
30 match do dl::check_for_errors_in {
32 dl::close(self.handle)
36 Err(str) => fail!(str)
42 /// Lazily open a dynamic library. When passed None it gives a
43 /// handle to the calling process
44 pub fn open(filename: Option<&path::Path>) -> Result<DynamicLibrary, ~str> {
46 let maybe_library = do dl::check_for_errors_in {
48 Some(name) => dl::open_external(name),
49 None => dl::open_internal()
53 // The dynamic library must not be constructed if there is
54 // an error opening the library so the destructor does not
58 Ok(handle) => Ok(DynamicLibrary { handle: handle })
63 /// Access the value at the symbol of the dynamic library
64 pub unsafe fn symbol<T>(&self, symbol: &str) -> Result<T, ~str> {
65 // This function should have a lifetime constraint of 'self on
66 // T but that feature is still unimplemented
68 let maybe_symbol_value = do dl::check_for_errors_in {
69 do symbol.to_c_str().with_ref |raw_string| {
70 dl::symbol(self.handle, raw_string)
74 // The value must not be constructed if there is an error so
75 // the destructor does not run.
76 match maybe_symbol_value {
78 Ok(symbol_value) => Ok(cast::transmute(symbol_value))
93 fn test_loading_cosine() {
94 // The math library does not need to be loaded since it is already
95 // statically linked in
96 let libm = match DynamicLibrary::open(None) {
97 Err(error) => fail!("Could not load self as module: %s", error),
101 // Unfortunately due to issue #6194 it is not possible to call
102 // this as a C function
103 let cosine: extern fn(libc::c_double) -> libc::c_double = unsafe {
104 match libm.symbol("cos") {
105 Err(error) => fail!("Could not load function cos: %s", error),
111 let expected_result = 1.0;
112 let result = cosine(argument);
113 if result != expected_result {
114 fail!("cos(%?) != %? but equaled %? instead", argument,
115 expected_result, result)
120 #[cfg(target_os = "linux")]
121 #[cfg(target_os = "macos")]
122 #[cfg(target_os = "freebsd")]
123 fn test_errors_do_not_crash() {
124 // Open /dev/null as a library to get an error, and make sure
125 // that only causes an error, and not a crash.
126 let path = GenericPath::from_str("/dev/null");
127 match DynamicLibrary::open(Some(&path)) {
129 Ok(_) => fail!("Successfully opened the empty library.")
134 #[cfg(target_os = "linux")]
135 #[cfg(target_os = "android")]
136 #[cfg(target_os = "macos")]
137 #[cfg(target_os = "freebsd")]
144 use unstable::sync::atomically;
147 pub unsafe fn open_external(filename: &path::Path) -> *libc::c_void {
148 do filename.to_c_str().with_ref |raw_name| {
149 dlopen(raw_name, Lazy as libc::c_int)
153 pub unsafe fn open_internal() -> *libc::c_void {
154 dlopen(ptr::null(), Lazy as libc::c_int)
157 pub fn check_for_errors_in<T>(f: &fn()->T) -> Result<T, ~str> {
160 let _old_error = dlerror();
164 let last_error = dlerror();
165 if ptr::null() == last_error {
168 Err(str::raw::from_c_str(last_error))
174 pub unsafe fn symbol(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void {
175 dlsym(handle, symbol)
177 pub unsafe fn close(handle: *libc::c_void) {
190 fn dlopen(filename: *libc::c_char, flag: libc::c_int) -> *libc::c_void;
191 fn dlerror() -> *libc::c_char;
192 fn dlsym(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void;
193 fn dlclose(handle: *libc::c_void) -> libc::c_int;
197 #[cfg(target_os = "win32")]
203 use unstable::sync::atomically;
206 pub unsafe fn open_external(filename: &path::Path) -> *libc::c_void {
207 do os::win32::as_utf16_p(filename.to_str()) |raw_name| {
208 LoadLibraryW(raw_name)
212 pub unsafe fn open_internal() -> *libc::c_void {
213 let handle = ptr::null();
214 GetModuleHandleExW(0 as libc::DWORD, ptr::null(), &handle as **libc::c_void);
218 pub fn check_for_errors_in<T>(f: &fn()->T) -> Result<T, ~str> {
225 let error = os::errno();
229 Err(fmt!("Error code %?", error))
234 pub unsafe fn symbol(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void {
235 GetProcAddress(handle, symbol)
237 pub unsafe fn close(handle: *libc::c_void) {
238 FreeLibrary(handle); ()
241 #[link_name = "kernel32"]
243 fn SetLastError(error: u32);
244 fn LoadLibraryW(name: *u16) -> *libc::c_void;
245 fn GetModuleHandleExW(dwFlags: libc::DWORD, name: *u16,
246 handle: **libc::c_void) -> *libc::c_void;
247 fn GetProcAddress(handle: *libc::c_void, name: *libc::c_char) -> *libc::c_void;
248 fn FreeLibrary(handle: *libc::c_void);