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
25 pub struct DynamicLibrary { priv handle: *libc::c_void }
27 impl Drop for DynamicLibrary {
29 match do dl::check_for_errors_in {
31 dl::close(self.handle)
35 Err(str) => fail!(str)
41 /// Lazily open a dynamic library. When passed None it gives a
42 /// handle to the calling process
43 pub fn open(filename: Option<&path::Path>) -> Result<DynamicLibrary, ~str> {
44 do dl::check_for_errors_in {
46 DynamicLibrary { handle:
48 Some(name) => dl::open_external(name),
49 None => dl::open_internal()
56 /// Access the value at the symbol of the dynamic library
57 pub unsafe fn symbol<T>(&self, symbol: &str) -> Result<T, ~str> {
58 // This function should have a lifetime constraint of 'self on
59 // T but that feature is still unimplemented
61 do dl::check_for_errors_in {
62 let symbol_value = do symbol.as_c_str |raw_string| {
63 dl::symbol(self.handle, raw_string)
66 cast::transmute(symbol_value)
72 #[ignore(cfg(windows))]
73 priv fn test_loading_cosine () {
74 // The math library does not need to be loaded since it is already
75 // statically linked in
76 let libm = match DynamicLibrary::open(None) {
77 Err (error) => fail!("Could not load self as module: %s", error),
81 // Unfortunately due to issue #6194 it is not possible to call
82 // this as a C function
83 let cosine: extern fn(libc::c_double) -> libc::c_double = unsafe {
84 match libm.symbol("cos") {
85 Err (error) => fail!("Could not load function cos: %s", error),
91 let expected_result = 1.0;
92 let result = cosine(argument);
93 if result != expected_result {
94 fail!("cos(%?) != %? but equaled %? instead", argument,
95 expected_result, result)
99 #[cfg(target_os = "linux")]
100 #[cfg(target_os = "android")]
101 #[cfg(target_os = "macos")]
102 #[cfg(target_os = "freebsd")]
111 pub unsafe fn open_external(filename: &path::Path) -> *libc::c_void {
112 do filename.to_str().as_c_str |raw_name| {
113 dlopen(raw_name, Lazy as libc::c_int)
117 pub unsafe fn open_internal() -> *libc::c_void {
118 dlopen(ptr::null(), Lazy as libc::c_int)
121 pub fn check_for_errors_in<T>(f: &fn()->T) -> Result<T, ~str> {
123 do task::atomically {
124 let _old_error = dlerror();
128 let last_error = dlerror();
129 if ptr::null() == last_error {
132 Err(str::raw::from_c_str(last_error))
138 pub unsafe fn symbol(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void {
139 dlsym(handle, symbol)
141 pub unsafe fn close(handle: *libc::c_void) {
154 fn dlopen(filename: *libc::c_char, flag: libc::c_int) -> *libc::c_void;
155 fn dlerror() -> *libc::c_char;
156 fn dlsym(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void;
157 fn dlclose(handle: *libc::c_void) -> libc::c_int;
161 #[cfg(target_os = "win32")]
170 pub unsafe fn open_external(filename: &path::Path) -> *libc::c_void {
171 do os::win32::as_utf16_p(filename.to_str()) |raw_name| {
172 LoadLibraryW(raw_name)
176 pub unsafe fn open_internal() -> *libc::c_void {
177 let handle = ptr::null();
178 GetModuleHandleExW(0 as libc::DWORD, ptr::null(), &handle as **libc::c_void);
182 pub fn check_for_errors_in<T>(f: &fn()->T) -> Result<T, ~str> {
184 do task::atomically {
189 let error = os::errno();
193 Err(fmt!("Error code %?", error))
198 pub unsafe fn symbol(handle: *libc::c_void, symbol: *libc::c_char) -> *libc::c_void {
199 GetProcAddress(handle, symbol)
201 pub unsafe fn close(handle: *libc::c_void) {
202 FreeLibrary(handle); ()
205 #[link_name = "kernel32"]
207 fn SetLastError(error: u32);
208 fn LoadLibraryW(name: *u16) -> *libc::c_void;
209 fn GetModuleHandleExW(dwFlags: libc::DWORD, name: *u16,
210 handle: **libc::c_void) -> *libc::c_void;
211 fn GetProcAddress(handle: *libc::c_void, name: *libc::c_char) -> *libc::c_void;
212 fn FreeLibrary(handle: *libc::c_void);