std/os/windows/process.rs
1//! Windows-specific extensions to primitives in the [`std::process`] module.
2//!
3//! [`std::process`]: crate::process
4
5#![stable(feature = "process_extensions", since = "1.2.0")]
6
7use crate::ffi::{OsStr, c_void};
8use crate::mem::MaybeUninit;
9use crate::os::windows::io::{
10 AsHandle, AsRawHandle, BorrowedHandle, FromRawHandle, IntoRawHandle, OwnedHandle, RawHandle,
11};
12use crate::sealed::Sealed;
13use crate::sys_common::{AsInner, AsInnerMut, FromInner, IntoInner};
14use crate::{io, marker, process, ptr, sys};
15
16#[stable(feature = "process_extensions", since = "1.2.0")]
17impl FromRawHandle for process::Stdio {
18 unsafe fn from_raw_handle(handle: RawHandle) -> process::Stdio {
19 let handle = unsafe { sys::handle::Handle::from_raw_handle(handle as *mut _) };
20 let io = sys::process::Stdio::Handle(handle);
21 process::Stdio::from_inner(io)
22 }
23}
24
25#[stable(feature = "io_safety", since = "1.63.0")]
26impl From<OwnedHandle> for process::Stdio {
27 /// Takes ownership of a handle and returns a [`Stdio`](process::Stdio)
28 /// that can attach a stream to it.
29 fn from(handle: OwnedHandle) -> process::Stdio {
30 let handle = sys::handle::Handle::from_inner(handle);
31 let io = sys::process::Stdio::Handle(handle);
32 process::Stdio::from_inner(io)
33 }
34}
35
36#[stable(feature = "process_extensions", since = "1.2.0")]
37impl AsRawHandle for process::Child {
38 #[inline]
39 fn as_raw_handle(&self) -> RawHandle {
40 self.as_inner().handle().as_raw_handle() as *mut _
41 }
42}
43
44#[stable(feature = "io_safety", since = "1.63.0")]
45impl AsHandle for process::Child {
46 #[inline]
47 fn as_handle(&self) -> BorrowedHandle<'_> {
48 self.as_inner().handle().as_handle()
49 }
50}
51
52#[stable(feature = "into_raw_os", since = "1.4.0")]
53impl IntoRawHandle for process::Child {
54 fn into_raw_handle(self) -> RawHandle {
55 self.into_inner().into_handle().into_raw_handle() as *mut _
56 }
57}
58
59#[stable(feature = "io_safety", since = "1.63.0")]
60impl From<process::Child> for OwnedHandle {
61 /// Takes ownership of a [`Child`](process::Child)'s process handle.
62 fn from(child: process::Child) -> OwnedHandle {
63 child.into_inner().into_handle().into_inner()
64 }
65}
66
67#[stable(feature = "process_extensions", since = "1.2.0")]
68impl AsRawHandle for process::ChildStdin {
69 #[inline]
70 fn as_raw_handle(&self) -> RawHandle {
71 self.as_inner().handle().as_raw_handle() as *mut _
72 }
73}
74
75#[stable(feature = "process_extensions", since = "1.2.0")]
76impl AsRawHandle for process::ChildStdout {
77 #[inline]
78 fn as_raw_handle(&self) -> RawHandle {
79 self.as_inner().handle().as_raw_handle() as *mut _
80 }
81}
82
83#[stable(feature = "process_extensions", since = "1.2.0")]
84impl AsRawHandle for process::ChildStderr {
85 #[inline]
86 fn as_raw_handle(&self) -> RawHandle {
87 self.as_inner().handle().as_raw_handle() as *mut _
88 }
89}
90
91#[stable(feature = "into_raw_os", since = "1.4.0")]
92impl IntoRawHandle for process::ChildStdin {
93 fn into_raw_handle(self) -> RawHandle {
94 self.into_inner().into_handle().into_raw_handle() as *mut _
95 }
96}
97
98#[stable(feature = "into_raw_os", since = "1.4.0")]
99impl IntoRawHandle for process::ChildStdout {
100 fn into_raw_handle(self) -> RawHandle {
101 self.into_inner().into_handle().into_raw_handle() as *mut _
102 }
103}
104
105#[stable(feature = "into_raw_os", since = "1.4.0")]
106impl IntoRawHandle for process::ChildStderr {
107 fn into_raw_handle(self) -> RawHandle {
108 self.into_inner().into_handle().into_raw_handle() as *mut _
109 }
110}
111
112/// Creates a `ChildStdin` from the provided `OwnedHandle`.
113///
114/// The provided handle must be asynchronous, as reading and
115/// writing from and to it is implemented using asynchronous APIs.
116#[stable(feature = "child_stream_from_fd", since = "1.74.0")]
117impl From<OwnedHandle> for process::ChildStdin {
118 fn from(handle: OwnedHandle) -> process::ChildStdin {
119 let handle = sys::handle::Handle::from_inner(handle);
120 let pipe = sys::pipe::AnonPipe::from_inner(handle);
121 process::ChildStdin::from_inner(pipe)
122 }
123}
124
125/// Creates a `ChildStdout` from the provided `OwnedHandle`.
126///
127/// The provided handle must be asynchronous, as reading and
128/// writing from and to it is implemented using asynchronous APIs.
129#[stable(feature = "child_stream_from_fd", since = "1.74.0")]
130impl From<OwnedHandle> for process::ChildStdout {
131 fn from(handle: OwnedHandle) -> process::ChildStdout {
132 let handle = sys::handle::Handle::from_inner(handle);
133 let pipe = sys::pipe::AnonPipe::from_inner(handle);
134 process::ChildStdout::from_inner(pipe)
135 }
136}
137
138/// Creates a `ChildStderr` from the provided `OwnedHandle`.
139///
140/// The provided handle must be asynchronous, as reading and
141/// writing from and to it is implemented using asynchronous APIs.
142#[stable(feature = "child_stream_from_fd", since = "1.74.0")]
143impl From<OwnedHandle> for process::ChildStderr {
144 fn from(handle: OwnedHandle) -> process::ChildStderr {
145 let handle = sys::handle::Handle::from_inner(handle);
146 let pipe = sys::pipe::AnonPipe::from_inner(handle);
147 process::ChildStderr::from_inner(pipe)
148 }
149}
150
151/// Windows-specific extensions to [`process::ExitStatus`].
152///
153/// This trait is sealed: it cannot be implemented outside the standard library.
154/// This is so that future additional methods are not breaking changes.
155#[stable(feature = "exit_status_from", since = "1.12.0")]
156pub trait ExitStatusExt: Sealed {
157 /// Creates a new `ExitStatus` from the raw underlying `u32` return value of
158 /// a process.
159 #[stable(feature = "exit_status_from", since = "1.12.0")]
160 fn from_raw(raw: u32) -> Self;
161}
162
163#[stable(feature = "exit_status_from", since = "1.12.0")]
164impl ExitStatusExt for process::ExitStatus {
165 fn from_raw(raw: u32) -> Self {
166 process::ExitStatus::from_inner(From::from(raw))
167 }
168}
169
170/// Windows-specific extensions to the [`process::Command`] builder.
171///
172/// This trait is sealed: it cannot be implemented outside the standard library.
173/// This is so that future additional methods are not breaking changes.
174#[stable(feature = "windows_process_extensions", since = "1.16.0")]
175pub trait CommandExt: Sealed {
176 /// Sets the [process creation flags][1] to be passed to `CreateProcess`.
177 ///
178 /// These will always be ORed with `CREATE_UNICODE_ENVIRONMENT`.
179 ///
180 /// [1]: https://docs.microsoft.com/en-us/windows/win32/procthread/process-creation-flags
181 #[stable(feature = "windows_process_extensions", since = "1.16.0")]
182 fn creation_flags(&mut self, flags: u32) -> &mut process::Command;
183
184 /// Sets the field `wShowWindow` of [STARTUPINFO][1] that is passed to `CreateProcess`.
185 /// Allowed values are the ones listed in
186 /// <https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-showwindow>
187 ///
188 /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfow>
189 #[unstable(feature = "windows_process_extensions_show_window", issue = "127544")]
190 fn show_window(&mut self, cmd_show: u16) -> &mut process::Command;
191
192 /// Forces all arguments to be wrapped in quote (`"`) characters.
193 ///
194 /// This is useful for passing arguments to [MSYS2/Cygwin][1] based
195 /// executables: these programs will expand unquoted arguments containing
196 /// wildcard characters (`?` and `*`) by searching for any file paths
197 /// matching the wildcard pattern.
198 ///
199 /// Adding quotes has no effect when passing arguments to programs
200 /// that use [msvcrt][2]. This includes programs built with both
201 /// MinGW and MSVC.
202 ///
203 /// [1]: <https://github.com/msys2/MSYS2-packages/issues/2176>
204 /// [2]: <https://msdn.microsoft.com/en-us/library/17w5ykft.aspx>
205 #[unstable(feature = "windows_process_extensions_force_quotes", issue = "82227")]
206 fn force_quotes(&mut self, enabled: bool) -> &mut process::Command;
207
208 /// Append literal text to the command line without any quoting or escaping.
209 ///
210 /// This is useful for passing arguments to applications that don't follow
211 /// the standard C run-time escaping rules, such as `cmd.exe /c`.
212 ///
213 /// # Batch files
214 ///
215 /// Note the `cmd /c` command line has slightly different escaping rules than batch files
216 /// themselves. If possible, it may be better to write complex arguments to a temporary
217 /// `.bat` file, with appropriate escaping, and simply run that using:
218 ///
219 /// ```no_run
220 /// # use std::process::Command;
221 /// # let temp_bat_file = "";
222 /// # #[allow(unused)]
223 /// let output = Command::new("cmd").args(["/c", &format!("\"{temp_bat_file}\"")]).output();
224 /// ```
225 ///
226 /// # Example
227 ///
228 /// Run a batch script using both trusted and untrusted arguments.
229 ///
230 /// ```no_run
231 /// #[cfg(windows)]
232 /// // `my_script_path` is a path to known bat file.
233 /// // `user_name` is an untrusted name given by the user.
234 /// fn run_script(
235 /// my_script_path: &str,
236 /// user_name: &str,
237 /// ) -> Result<std::process::Output, std::io::Error> {
238 /// use std::io::{Error, ErrorKind};
239 /// use std::os::windows::process::CommandExt;
240 /// use std::process::Command;
241 ///
242 /// // Create the command line, making sure to quote the script path.
243 /// // This assumes the fixed arguments have been tested to work with the script we're using.
244 /// let mut cmd_args = format!(r#""{my_script_path}" "--features=[a,b,c]""#);
245 ///
246 /// // Make sure the user name is safe. In particular we need to be
247 /// // cautious of ascii symbols that cmd may interpret specially.
248 /// // Here we only allow alphanumeric characters.
249 /// if !user_name.chars().all(|c| c.is_alphanumeric()) {
250 /// return Err(Error::new(ErrorKind::InvalidInput, "invalid user name"));
251 /// }
252 ///
253 /// // now we have validated the user name, let's add that too.
254 /// cmd_args.push_str(" --user ");
255 /// cmd_args.push_str(user_name);
256 ///
257 /// // call cmd.exe and return the output
258 /// Command::new("cmd.exe")
259 /// .arg("/c")
260 /// // surround the entire command in an extra pair of quotes, as required by cmd.exe.
261 /// .raw_arg(&format!("\"{cmd_args}\""))
262 /// .output()
263 /// }
264 /// ````
265 #[stable(feature = "windows_process_extensions_raw_arg", since = "1.62.0")]
266 fn raw_arg<S: AsRef<OsStr>>(&mut self, text_to_append_as_is: S) -> &mut process::Command;
267
268 /// When [`process::Command`] creates pipes, request that our side is always async.
269 ///
270 /// By default [`process::Command`] may choose to use pipes where both ends
271 /// are opened for synchronous read or write operations. By using
272 /// `async_pipes(true)`, this behavior is overridden so that our side is
273 /// always async.
274 ///
275 /// This is important because if doing async I/O a pipe or a file has to be
276 /// opened for async access.
277 ///
278 /// The end of the pipe sent to the child process will always be synchronous
279 /// regardless of this option.
280 ///
281 /// # Example
282 ///
283 /// ```
284 /// #![feature(windows_process_extensions_async_pipes)]
285 /// use std::os::windows::process::CommandExt;
286 /// use std::process::{Command, Stdio};
287 ///
288 /// # let program = "";
289 ///
290 /// Command::new(program)
291 /// .async_pipes(true)
292 /// .stdin(Stdio::piped())
293 /// .stdout(Stdio::piped())
294 /// .stderr(Stdio::piped());
295 /// ```
296 #[unstable(feature = "windows_process_extensions_async_pipes", issue = "98289")]
297 fn async_pipes(&mut self, always_async: bool) -> &mut process::Command;
298
299 /// Executes the command as a child process with the given
300 /// [`ProcThreadAttributeList`], returning a handle to it.
301 ///
302 /// This method enables the customization of attributes for the spawned
303 /// child process on Windows systems.
304 /// Attributes offer extended configurability for process creation,
305 /// but their usage can be intricate and potentially unsafe.
306 ///
307 /// # Note
308 ///
309 /// By default, stdin, stdout, and stderr are inherited from the parent
310 /// process.
311 ///
312 /// # Example
313 ///
314 /// ```
315 /// #![feature(windows_process_extensions_raw_attribute)]
316 /// use std::os::windows::io::AsRawHandle;
317 /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
318 /// use std::process::Command;
319 ///
320 /// # struct ProcessDropGuard(std::process::Child);
321 /// # impl Drop for ProcessDropGuard {
322 /// # fn drop(&mut self) {
323 /// # let _ = self.0.kill();
324 /// # }
325 /// # }
326 /// #
327 /// let parent = Command::new("cmd").spawn()?;
328 /// let parent_process_handle = parent.as_raw_handle();
329 /// # let parent = ProcessDropGuard(parent);
330 ///
331 /// const PROC_THREAD_ATTRIBUTE_PARENT_PROCESS: usize = 0x00020000;
332 /// let mut attribute_list = ProcThreadAttributeList::build()
333 /// .attribute(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, &parent_process_handle)
334 /// .finish()
335 /// .unwrap();
336 ///
337 /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
338 /// #
339 /// # child.kill()?;
340 /// # Ok::<(), std::io::Error>(())
341 /// ```
342 #[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
343 fn spawn_with_attributes(
344 &mut self,
345 attribute_list: &ProcThreadAttributeList<'_>,
346 ) -> io::Result<process::Child>;
347
348 /// When true, sets the `STARTF_RUNFULLSCREEN` flag on the [STARTUPINFO][1] struct before passing it to `CreateProcess`.
349 ///
350 /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
351 #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
352 fn startupinfo_fullscreen(&mut self, enabled: bool) -> &mut process::Command;
353
354 /// When true, sets the `STARTF_UNTRUSTEDSOURCE` flag on the [STARTUPINFO][1] struct before passing it to `CreateProcess`.
355 ///
356 /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
357 #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
358 fn startupinfo_untrusted_source(&mut self, enabled: bool) -> &mut process::Command;
359
360 /// When specified, sets the following flags on the [STARTUPINFO][1] struct before passing it to `CreateProcess`:
361 /// - If `Some(true)`, sets `STARTF_FORCEONFEEDBACK`
362 /// - If `Some(false)`, sets `STARTF_FORCEOFFFEEDBACK`
363 /// - If `None`, does not set any flags
364 ///
365 /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
366 #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
367 fn startupinfo_force_feedback(&mut self, enabled: Option<bool>) -> &mut process::Command;
368
369 /// If this flag is set to `true`, each inheritable handle in the calling
370 /// process is inherited by the new process. If the flag is `false`, the
371 /// handles are not inherited.
372 ///
373 /// The default value for this flag is `true`.
374 ///
375 /// **Note** that inherited handles have the same value and access rights
376 /// as the original handles. For additional discussion of inheritable handles,
377 /// see the [Remarks][1] section of the `CreateProcessW` documentation.
378 ///
379 /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw#remarks
380 #[unstable(feature = "windows_process_extensions_inherit_handles", issue = "146407")]
381 fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command;
382}
383
384#[stable(feature = "windows_process_extensions", since = "1.16.0")]
385impl CommandExt for process::Command {
386 fn creation_flags(&mut self, flags: u32) -> &mut process::Command {
387 self.as_inner_mut().creation_flags(flags);
388 self
389 }
390
391 fn show_window(&mut self, cmd_show: u16) -> &mut process::Command {
392 self.as_inner_mut().show_window(Some(cmd_show));
393 self
394 }
395
396 fn force_quotes(&mut self, enabled: bool) -> &mut process::Command {
397 self.as_inner_mut().force_quotes(enabled);
398 self
399 }
400
401 fn raw_arg<S: AsRef<OsStr>>(&mut self, raw_text: S) -> &mut process::Command {
402 self.as_inner_mut().raw_arg(raw_text.as_ref());
403 self
404 }
405
406 fn async_pipes(&mut self, always_async: bool) -> &mut process::Command {
407 // FIXME: This currently has an intentional no-op implementation.
408 // For the time being our side of the pipes will always be async.
409 // Once the ecosystem has adjusted, we may then be able to start making
410 // use of synchronous pipes within the standard library.
411 let _ = always_async;
412 self
413 }
414
415 fn spawn_with_attributes(
416 &mut self,
417 attribute_list: &ProcThreadAttributeList<'_>,
418 ) -> io::Result<process::Child> {
419 self.as_inner_mut()
420 .spawn_with_attributes(sys::process::Stdio::Inherit, true, Some(attribute_list))
421 .map(process::Child::from_inner)
422 }
423
424 fn startupinfo_fullscreen(&mut self, enabled: bool) -> &mut process::Command {
425 self.as_inner_mut().startupinfo_fullscreen(enabled);
426 self
427 }
428
429 fn startupinfo_untrusted_source(&mut self, enabled: bool) -> &mut process::Command {
430 self.as_inner_mut().startupinfo_untrusted_source(enabled);
431 self
432 }
433
434 fn startupinfo_force_feedback(&mut self, enabled: Option<bool>) -> &mut process::Command {
435 self.as_inner_mut().startupinfo_force_feedback(enabled);
436 self
437 }
438
439 fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command {
440 self.as_inner_mut().inherit_handles(inherit_handles);
441 self
442 }
443}
444
445#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
446pub trait ChildExt: Sealed {
447 /// Extracts the main thread raw handle, without taking ownership
448 #[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
449 fn main_thread_handle(&self) -> BorrowedHandle<'_>;
450}
451
452#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
453impl ChildExt for process::Child {
454 fn main_thread_handle(&self) -> BorrowedHandle<'_> {
455 self.handle.main_thread_handle()
456 }
457}
458
459/// Windows-specific extensions to [`process::ExitCode`].
460///
461/// This trait is sealed: it cannot be implemented outside the standard library.
462/// This is so that future additional methods are not breaking changes.
463#[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
464pub trait ExitCodeExt: Sealed {
465 /// Creates a new `ExitCode` from the raw underlying `u32` return value of
466 /// a process.
467 ///
468 /// The exit code should not be 259, as this conflicts with the `STILL_ACTIVE`
469 /// macro returned from the `GetExitCodeProcess` function to signal that the
470 /// process has yet to run to completion.
471 #[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
472 fn from_raw(raw: u32) -> Self;
473}
474
475#[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
476impl ExitCodeExt for process::ExitCode {
477 fn from_raw(raw: u32) -> Self {
478 process::ExitCode::from_inner(From::from(raw))
479 }
480}
481
482/// A wrapper around windows [`ProcThreadAttributeList`][1].
483///
484/// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-initializeprocthreadattributelist>
485#[derive(Debug)]
486#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
487pub struct ProcThreadAttributeList<'a> {
488 attribute_list: Box<[MaybeUninit<u8>]>,
489 _lifetime_marker: marker::PhantomData<&'a ()>,
490}
491
492#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
493impl<'a> ProcThreadAttributeList<'a> {
494 /// Creates a new builder for constructing a [`ProcThreadAttributeList`].
495 pub fn build() -> ProcThreadAttributeListBuilder<'a> {
496 ProcThreadAttributeListBuilder::new()
497 }
498
499 /// Returns a pointer to the underling attribute list.
500 #[doc(hidden)]
501 pub fn as_ptr(&self) -> *const MaybeUninit<u8> {
502 self.attribute_list.as_ptr()
503 }
504}
505
506#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
507impl<'a> Drop for ProcThreadAttributeList<'a> {
508 /// Deletes the attribute list.
509 ///
510 /// This method calls [`DeleteProcThreadAttributeList`][1] to delete the
511 /// underlying attribute list.
512 ///
513 /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-deleteprocthreadattributelist>
514 fn drop(&mut self) {
515 let lp_attribute_list = self.attribute_list.as_mut_ptr().cast::<c_void>();
516 unsafe { sys::c::DeleteProcThreadAttributeList(lp_attribute_list) }
517 }
518}
519
520/// Builder for constructing a [`ProcThreadAttributeList`].
521#[derive(Clone, Debug)]
522#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
523pub struct ProcThreadAttributeListBuilder<'a> {
524 attributes: alloc::collections::BTreeMap<usize, ProcThreadAttributeValue>,
525 _lifetime_marker: marker::PhantomData<&'a ()>,
526}
527
528#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
529impl<'a> ProcThreadAttributeListBuilder<'a> {
530 fn new() -> Self {
531 ProcThreadAttributeListBuilder {
532 attributes: alloc::collections::BTreeMap::new(),
533 _lifetime_marker: marker::PhantomData,
534 }
535 }
536
537 /// Sets an attribute on the attribute list.
538 ///
539 /// The `attribute` parameter specifies the raw attribute to be set, while
540 /// the `value` parameter holds the value associated with that attribute.
541 /// Please refer to the [Windows documentation][1] for a list of valid attributes.
542 ///
543 /// # Note
544 ///
545 /// The maximum number of attributes is the value of [`u32::MAX`]. If this
546 /// limit is exceeded, the call to [`Self::finish`] will return an `Error`
547 /// indicating that the maximum number of attributes has been exceeded.
548 ///
549 /// # Safety Note
550 ///
551 /// Remember that improper use of attributes can lead to undefined behavior
552 /// or security vulnerabilities. Always consult the documentation and ensure
553 /// proper attribute values are used.
554 ///
555 /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-updateprocthreadattribute#parameters>
556 pub fn attribute<T>(self, attribute: usize, value: &'a T) -> Self {
557 unsafe {
558 self.raw_attribute(attribute, ptr::addr_of!(*value).cast::<c_void>(), size_of::<T>())
559 }
560 }
561
562 /// Sets a raw attribute on the attribute list.
563 ///
564 /// This function is useful for setting attributes with pointers or sizes
565 /// that cannot be derived directly from their values.
566 ///
567 /// # Safety
568 ///
569 /// This function is marked as `unsafe` because it deals with raw pointers
570 /// and sizes. It is the responsibility of the caller to ensure the value
571 /// lives longer than the resulting [`ProcThreadAttributeList`] as well as
572 /// the validity of the size parameter.
573 ///
574 /// # Example
575 ///
576 /// ```
577 /// #![feature(windows_process_extensions_raw_attribute)]
578 /// use std::ffi::c_void;
579 /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
580 /// use std::os::windows::raw::HANDLE;
581 /// use std::process::Command;
582 ///
583 /// #[repr(C)]
584 /// pub struct COORD {
585 /// pub X: i16,
586 /// pub Y: i16,
587 /// }
588 ///
589 /// unsafe extern "system" {
590 /// fn CreatePipe(
591 /// hreadpipe: *mut HANDLE,
592 /// hwritepipe: *mut HANDLE,
593 /// lppipeattributes: *const c_void,
594 /// nsize: u32,
595 /// ) -> i32;
596 /// fn CreatePseudoConsole(
597 /// size: COORD,
598 /// hinput: HANDLE,
599 /// houtput: HANDLE,
600 /// dwflags: u32,
601 /// phpc: *mut isize,
602 /// ) -> i32;
603 /// fn CloseHandle(hobject: HANDLE) -> i32;
604 /// }
605 ///
606 /// let [mut input_read_side, mut output_write_side, mut output_read_side, mut input_write_side] =
607 /// [unsafe { std::mem::zeroed::<HANDLE>() }; 4];
608 ///
609 /// unsafe {
610 /// CreatePipe(&mut input_read_side, &mut input_write_side, std::ptr::null(), 0);
611 /// CreatePipe(&mut output_read_side, &mut output_write_side, std::ptr::null(), 0);
612 /// }
613 ///
614 /// let size = COORD { X: 60, Y: 40 };
615 /// let mut h_pc = unsafe { std::mem::zeroed() };
616 /// unsafe { CreatePseudoConsole(size, input_read_side, output_write_side, 0, &mut h_pc) };
617 ///
618 /// unsafe { CloseHandle(input_read_side) };
619 /// unsafe { CloseHandle(output_write_side) };
620 ///
621 /// const PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE: usize = 131094;
622 ///
623 /// let attribute_list = unsafe {
624 /// ProcThreadAttributeList::build()
625 /// .raw_attribute(
626 /// PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE,
627 /// h_pc as *const c_void,
628 /// size_of::<isize>(),
629 /// )
630 /// .finish()?
631 /// };
632 ///
633 /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
634 /// #
635 /// # child.kill()?;
636 /// # Ok::<(), std::io::Error>(())
637 /// ```
638 pub unsafe fn raw_attribute<T>(
639 mut self,
640 attribute: usize,
641 value_ptr: *const T,
642 value_size: usize,
643 ) -> Self {
644 self.attributes.insert(
645 attribute,
646 ProcThreadAttributeValue { ptr: value_ptr.cast::<c_void>(), size: value_size },
647 );
648 self
649 }
650
651 /// Finalizes the construction of the `ProcThreadAttributeList`.
652 ///
653 /// # Errors
654 ///
655 /// Returns an error if the maximum number of attributes is exceeded
656 /// or if there is an I/O error during initialization.
657 pub fn finish(&self) -> io::Result<ProcThreadAttributeList<'a>> {
658 // To initialize our ProcThreadAttributeList, we need to determine
659 // how many bytes to allocate for it. The Windows API simplifies this
660 // process by allowing us to call `InitializeProcThreadAttributeList`
661 // with a null pointer to retrieve the required size.
662 let mut required_size = 0;
663 let Ok(attribute_count) = self.attributes.len().try_into() else {
664 return Err(io::const_error!(
665 io::ErrorKind::InvalidInput,
666 "maximum number of ProcThreadAttributes exceeded",
667 ));
668 };
669 unsafe {
670 sys::c::InitializeProcThreadAttributeList(
671 ptr::null_mut(),
672 attribute_count,
673 0,
674 &mut required_size,
675 )
676 };
677
678 let mut attribute_list = vec![MaybeUninit::uninit(); required_size].into_boxed_slice();
679
680 // Once we've allocated the necessary memory, it's safe to invoke
681 // `InitializeProcThreadAttributeList` to properly initialize the list.
682 sys::cvt(unsafe {
683 sys::c::InitializeProcThreadAttributeList(
684 attribute_list.as_mut_ptr().cast::<c_void>(),
685 attribute_count,
686 0,
687 &mut required_size,
688 )
689 })?;
690
691 // # Add our attributes to the buffer.
692 // It's theoretically possible for the attribute count to exceed a u32
693 // value. Therefore, we ensure that we don't add more attributes than
694 // the buffer was initialized for.
695 for (&attribute, value) in self.attributes.iter().take(attribute_count as usize) {
696 sys::cvt(unsafe {
697 sys::c::UpdateProcThreadAttribute(
698 attribute_list.as_mut_ptr().cast::<c_void>(),
699 0,
700 attribute,
701 value.ptr,
702 value.size,
703 ptr::null_mut(),
704 ptr::null_mut(),
705 )
706 })?;
707 }
708
709 Ok(ProcThreadAttributeList { attribute_list, _lifetime_marker: marker::PhantomData })
710 }
711}
712
713/// Wrapper around the value data to be used as a Process Thread Attribute.
714#[derive(Clone, Debug)]
715struct ProcThreadAttributeValue {
716 ptr: *const c_void,
717 size: usize,
718}