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::sys::{AsInner, AsInnerMut, FromInner, IntoInner};
13use crate::{io, marker, process, ptr, sys};
14
15#[stable(feature = "process_extensions", since = "1.2.0")]
16impl FromRawHandle for process::Stdio {
17    unsafe fn from_raw_handle(handle: RawHandle) -> process::Stdio {
18        let handle = unsafe { sys::handle::Handle::from_raw_handle(handle as *mut _) };
19        let io = sys::process::Stdio::Handle(handle);
20        process::Stdio::from_inner(io)
21    }
22}
23
24#[stable(feature = "io_safety", since = "1.63.0")]
25impl From<OwnedHandle> for process::Stdio {
26    /// Takes ownership of a handle and returns a [`Stdio`](process::Stdio)
27    /// that can attach a stream to it.
28    fn from(handle: OwnedHandle) -> process::Stdio {
29        let handle = sys::handle::Handle::from_inner(handle);
30        let io = sys::process::Stdio::Handle(handle);
31        process::Stdio::from_inner(io)
32    }
33}
34
35#[stable(feature = "process_extensions", since = "1.2.0")]
36impl AsRawHandle for process::Child {
37    #[inline]
38    fn as_raw_handle(&self) -> RawHandle {
39        self.as_inner().handle().as_raw_handle() as *mut _
40    }
41}
42
43#[stable(feature = "io_safety", since = "1.63.0")]
44impl AsHandle for process::Child {
45    #[inline]
46    fn as_handle(&self) -> BorrowedHandle<'_> {
47        self.as_inner().handle().as_handle()
48    }
49}
50
51#[stable(feature = "into_raw_os", since = "1.4.0")]
52impl IntoRawHandle for process::Child {
53    fn into_raw_handle(self) -> RawHandle {
54        self.into_inner().into_handle().into_raw_handle() as *mut _
55    }
56}
57
58#[stable(feature = "io_safety", since = "1.63.0")]
59impl From<process::Child> for OwnedHandle {
60    /// Takes ownership of a [`Child`](process::Child)'s process handle.
61    fn from(child: process::Child) -> OwnedHandle {
62        child.into_inner().into_handle().into_inner()
63    }
64}
65
66#[stable(feature = "process_extensions", since = "1.2.0")]
67impl AsRawHandle for process::ChildStdin {
68    #[inline]
69    fn as_raw_handle(&self) -> RawHandle {
70        self.as_inner().handle().as_raw_handle() as *mut _
71    }
72}
73
74#[stable(feature = "process_extensions", since = "1.2.0")]
75impl AsRawHandle for process::ChildStdout {
76    #[inline]
77    fn as_raw_handle(&self) -> RawHandle {
78        self.as_inner().handle().as_raw_handle() as *mut _
79    }
80}
81
82#[stable(feature = "process_extensions", since = "1.2.0")]
83impl AsRawHandle for process::ChildStderr {
84    #[inline]
85    fn as_raw_handle(&self) -> RawHandle {
86        self.as_inner().handle().as_raw_handle() as *mut _
87    }
88}
89
90#[stable(feature = "into_raw_os", since = "1.4.0")]
91impl IntoRawHandle for process::ChildStdin {
92    fn into_raw_handle(self) -> RawHandle {
93        self.into_inner().into_handle().into_raw_handle() as *mut _
94    }
95}
96
97#[stable(feature = "into_raw_os", since = "1.4.0")]
98impl IntoRawHandle for process::ChildStdout {
99    fn into_raw_handle(self) -> RawHandle {
100        self.into_inner().into_handle().into_raw_handle() as *mut _
101    }
102}
103
104#[stable(feature = "into_raw_os", since = "1.4.0")]
105impl IntoRawHandle for process::ChildStderr {
106    fn into_raw_handle(self) -> RawHandle {
107        self.into_inner().into_handle().into_raw_handle() as *mut _
108    }
109}
110
111/// Creates a `ChildStdin` from the provided `OwnedHandle`.
112///
113/// The provided handle must be asynchronous, as reading and
114/// writing from and to it is implemented using asynchronous APIs.
115#[stable(feature = "child_stream_from_fd", since = "1.74.0")]
116impl From<OwnedHandle> for process::ChildStdin {
117    fn from(handle: OwnedHandle) -> process::ChildStdin {
118        let handle = sys::handle::Handle::from_inner(handle);
119        let pipe = sys::process::ChildPipe::from_inner(handle);
120        process::ChildStdin::from_inner(pipe)
121    }
122}
123
124/// Creates a `ChildStdout` from the provided `OwnedHandle`.
125///
126/// The provided handle must be asynchronous, as reading and
127/// writing from and to it is implemented using asynchronous APIs.
128#[stable(feature = "child_stream_from_fd", since = "1.74.0")]
129impl From<OwnedHandle> for process::ChildStdout {
130    fn from(handle: OwnedHandle) -> process::ChildStdout {
131        let handle = sys::handle::Handle::from_inner(handle);
132        let pipe = sys::process::ChildPipe::from_inner(handle);
133        process::ChildStdout::from_inner(pipe)
134    }
135}
136
137/// Creates a `ChildStderr` from the provided `OwnedHandle`.
138///
139/// The provided handle must be asynchronous, as reading and
140/// writing from and to it is implemented using asynchronous APIs.
141#[stable(feature = "child_stream_from_fd", since = "1.74.0")]
142impl From<OwnedHandle> for process::ChildStderr {
143    fn from(handle: OwnedHandle) -> process::ChildStderr {
144        let handle = sys::handle::Handle::from_inner(handle);
145        let pipe = sys::process::ChildPipe::from_inner(handle);
146        process::ChildStderr::from_inner(pipe)
147    }
148}
149
150/// Windows-specific extensions to [`process::ExitStatus`].
151#[stable(feature = "exit_status_from", since = "1.12.0")]
152pub impl(self) trait ExitStatusExt {
153    /// Creates a new `ExitStatus` from the raw underlying `u32` return value of
154    /// a process.
155    #[stable(feature = "exit_status_from", since = "1.12.0")]
156    fn from_raw(raw: u32) -> Self;
157}
158
159#[stable(feature = "exit_status_from", since = "1.12.0")]
160impl ExitStatusExt for process::ExitStatus {
161    fn from_raw(raw: u32) -> Self {
162        process::ExitStatus::from_inner(From::from(raw))
163    }
164}
165
166/// Windows-specific extensions to the [`process::Command`] builder.
167#[stable(feature = "windows_process_extensions", since = "1.16.0")]
168pub impl(self) trait CommandExt {
169    /// Sets the [process creation flags][1] to be passed to `CreateProcess`.
170    ///
171    /// These will always be ORed with `CREATE_UNICODE_ENVIRONMENT`.
172    ///
173    /// [1]: https://docs.microsoft.com/en-us/windows/win32/procthread/process-creation-flags
174    #[stable(feature = "windows_process_extensions", since = "1.16.0")]
175    fn creation_flags(&mut self, flags: u32) -> &mut process::Command;
176
177    /// Sets the field `wShowWindow` of [STARTUPINFO][1] that is passed to `CreateProcess`.
178    /// Allowed values are the ones listed in
179    /// <https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-showwindow>
180    ///
181    /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfow>
182    #[unstable(feature = "windows_process_extensions_show_window", issue = "127544")]
183    fn show_window(&mut self, cmd_show: u16) -> &mut process::Command;
184
185    /// Forces all arguments to be wrapped in quote (`"`) characters.
186    ///
187    /// This is useful for passing arguments to [MSYS2/Cygwin][1] based
188    /// executables: these programs will expand unquoted arguments containing
189    /// wildcard characters (`?` and `*`) by searching for any file paths
190    /// matching the wildcard pattern.
191    ///
192    /// Adding quotes has no effect when passing arguments to programs
193    /// that use [msvcrt][2]. This includes programs built with both
194    /// MinGW and MSVC.
195    ///
196    /// [1]: <https://github.com/msys2/MSYS2-packages/issues/2176>
197    /// [2]: <https://msdn.microsoft.com/en-us/library/17w5ykft.aspx>
198    #[unstable(feature = "windows_process_extensions_force_quotes", issue = "82227")]
199    fn force_quotes(&mut self, enabled: bool) -> &mut process::Command;
200
201    /// Append literal text to the command line without any quoting or escaping.
202    ///
203    /// This is useful for passing arguments to applications that don't follow
204    /// the standard C run-time escaping rules, such as `cmd.exe /c`.
205    ///
206    /// # Batch files
207    ///
208    /// Note the `cmd /c` command line has slightly different escaping rules than batch files
209    /// themselves. If possible, it may be better to write complex arguments to a temporary
210    /// `.bat` file, with appropriate escaping, and simply run that using:
211    ///
212    /// ```no_run
213    /// # use std::process::Command;
214    /// # let temp_bat_file = "";
215    /// # #[allow(unused)]
216    /// let output = Command::new("cmd").args(["/c", &format!("\"{temp_bat_file}\"")]).output();
217    /// ```
218    ///
219    /// # Example
220    ///
221    /// Run a batch script using both trusted and untrusted arguments.
222    ///
223    /// ```no_run
224    /// #[cfg(windows)]
225    /// // `my_script_path` is a path to known bat file.
226    /// // `user_name` is an untrusted name given by the user.
227    /// fn run_script(
228    ///     my_script_path: &str,
229    ///     user_name: &str,
230    /// ) -> Result<std::process::Output, std::io::Error> {
231    ///     use std::io::{Error, ErrorKind};
232    ///     use std::os::windows::process::CommandExt;
233    ///     use std::process::Command;
234    ///
235    ///     // Create the command line, making sure to quote the script path.
236    ///     // This assumes the fixed arguments have been tested to work with the script we're using.
237    ///     let mut cmd_args = format!(r#""{my_script_path}" "--features=[a,b,c]""#);
238    ///
239    ///     // Make sure the user name is safe. In particular we need to be
240    ///     // cautious of ascii symbols that cmd may interpret specially.
241    ///     // Here we only allow alphanumeric characters.
242    ///     if !user_name.chars().all(|c| c.is_alphanumeric()) {
243    ///         return Err(Error::new(ErrorKind::InvalidInput, "invalid user name"));
244    ///     }
245    ///
246    ///     // now we have validated the user name, let's add that too.
247    ///     cmd_args.push_str(" --user ");
248    ///     cmd_args.push_str(user_name);
249    ///
250    ///     // call cmd.exe and return the output
251    ///     Command::new("cmd.exe")
252    ///         .arg("/c")
253    ///         // surround the entire command in an extra pair of quotes, as required by cmd.exe.
254    ///         .raw_arg(&format!("\"{cmd_args}\""))
255    ///         .output()
256    /// }
257    /// ````
258    #[stable(feature = "windows_process_extensions_raw_arg", since = "1.62.0")]
259    fn raw_arg<S: AsRef<OsStr>>(&mut self, text_to_append_as_is: S) -> &mut process::Command;
260
261    /// When [`process::Command`] creates pipes, request that our side is always async.
262    ///
263    /// By default [`process::Command`] may choose to use pipes where both ends
264    /// are opened for synchronous read or write operations. By using
265    /// `async_pipes(true)`, this behavior is overridden so that our side is
266    /// always async.
267    ///
268    /// This is important because if doing async I/O a pipe or a file has to be
269    /// opened for async access.
270    ///
271    /// The end of the pipe sent to the child process will always be synchronous
272    /// regardless of this option.
273    ///
274    /// # Example
275    ///
276    #[cfg_attr(windows, doc = "```")]
277    #[cfg_attr(not(windows), doc = "```ignore (needs windows)")]
278    /// #![feature(windows_process_extensions_async_pipes)]
279    /// use std::os::windows::process::CommandExt;
280    /// use std::process::{Command, Stdio};
281    ///
282    /// # let program = "";
283    ///
284    /// Command::new(program)
285    ///     .async_pipes(true)
286    ///     .stdin(Stdio::piped())
287    ///     .stdout(Stdio::piped())
288    ///     .stderr(Stdio::piped());
289    /// ```
290    #[unstable(feature = "windows_process_extensions_async_pipes", issue = "98289")]
291    fn async_pipes(&mut self, always_async: bool) -> &mut process::Command;
292
293    /// Executes the command as a child process with the given
294    /// [`ProcThreadAttributeList`], returning a handle to it.
295    ///
296    /// This method enables the customization of attributes for the spawned
297    /// child process on Windows systems.
298    /// Attributes offer extended configurability for process creation,
299    /// but their usage can be intricate and potentially unsafe.
300    ///
301    /// # Note
302    ///
303    /// By default, stdin, stdout, and stderr are inherited from the parent
304    /// process.
305    ///
306    /// # Example
307    ///
308    #[cfg_attr(windows, doc = "```")]
309    #[cfg_attr(not(windows), doc = "```ignore (needs windows)")]
310    /// #![feature(windows_process_extensions_raw_attribute)]
311    /// use std::os::windows::io::AsRawHandle;
312    /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
313    /// use std::process::Command;
314    ///
315    /// # struct ProcessDropGuard(std::process::Child);
316    /// # impl Drop for ProcessDropGuard {
317    /// #     fn drop(&mut self) {
318    /// #         let _ = self.0.kill();
319    /// #     }
320    /// # }
321    /// #
322    /// let parent = Command::new("cmd").spawn()?;
323    /// let parent_process_handle = parent.as_raw_handle();
324    /// # let parent = ProcessDropGuard(parent);
325    ///
326    /// const PROC_THREAD_ATTRIBUTE_PARENT_PROCESS: usize = 0x00020000;
327    /// let mut attribute_list = ProcThreadAttributeList::build()
328    ///     .attribute(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, &parent_process_handle)
329    ///     .finish()
330    ///     .unwrap();
331    ///
332    /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
333    /// #
334    /// # child.kill()?;
335    /// # Ok::<(), std::io::Error>(())
336    /// ```
337    #[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
338    fn spawn_with_attributes(
339        &mut self,
340        attribute_list: &ProcThreadAttributeList<'_>,
341    ) -> io::Result<process::Child>;
342
343    /// When true, sets the `STARTF_RUNFULLSCREEN` flag on the [STARTUPINFO][1] struct before passing it to `CreateProcess`.
344    ///
345    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
346    #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
347    fn startupinfo_fullscreen(&mut self, enabled: bool) -> &mut process::Command;
348
349    /// When true, sets the `STARTF_UNTRUSTEDSOURCE` flag on the [STARTUPINFO][1] struct before passing it to `CreateProcess`.
350    ///
351    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
352    #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
353    fn startupinfo_untrusted_source(&mut self, enabled: bool) -> &mut process::Command;
354
355    /// When specified, sets the following flags on the [STARTUPINFO][1] struct before passing it to `CreateProcess`:
356    /// - If `Some(true)`, sets `STARTF_FORCEONFEEDBACK`
357    /// - If `Some(false)`, sets `STARTF_FORCEOFFFEEDBACK`
358    /// - If `None`, does not set any flags
359    ///
360    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
361    #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
362    fn startupinfo_force_feedback(&mut self, enabled: Option<bool>) -> &mut process::Command;
363
364    /// If this flag is set to `true`, each inheritable handle in the calling
365    /// process is inherited by the new process. If the flag is `false`, the
366    /// handles are not inherited.
367    ///
368    /// The default value for this flag is `true`.
369    ///
370    /// **Note** that inherited handles have the same value and access rights
371    /// as the original handles. For additional discussion of inheritable handles,
372    /// see the [Remarks][1] section of the `CreateProcessW` documentation.
373    ///
374    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw#remarks
375    #[unstable(feature = "windows_process_extensions_inherit_handles", issue = "146407")]
376    fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command;
377}
378
379#[stable(feature = "windows_process_extensions", since = "1.16.0")]
380impl CommandExt for process::Command {
381    fn creation_flags(&mut self, flags: u32) -> &mut process::Command {
382        self.as_inner_mut().creation_flags(flags);
383        self
384    }
385
386    fn show_window(&mut self, cmd_show: u16) -> &mut process::Command {
387        self.as_inner_mut().show_window(Some(cmd_show));
388        self
389    }
390
391    fn force_quotes(&mut self, enabled: bool) -> &mut process::Command {
392        self.as_inner_mut().force_quotes(enabled);
393        self
394    }
395
396    fn raw_arg<S: AsRef<OsStr>>(&mut self, raw_text: S) -> &mut process::Command {
397        self.as_inner_mut().raw_arg(raw_text.as_ref());
398        self
399    }
400
401    fn async_pipes(&mut self, always_async: bool) -> &mut process::Command {
402        // FIXME: This currently has an intentional no-op implementation.
403        // For the time being our side of the pipes will always be async.
404        // Once the ecosystem has adjusted, we may then be able to start making
405        // use of synchronous pipes within the standard library.
406        let _ = always_async;
407        self
408    }
409
410    fn spawn_with_attributes(
411        &mut self,
412        attribute_list: &ProcThreadAttributeList<'_>,
413    ) -> io::Result<process::Child> {
414        self.as_inner_mut()
415            .spawn_with_attributes(sys::process::Stdio::Inherit, true, Some(attribute_list))
416            .map(process::Child::from_inner)
417    }
418
419    fn startupinfo_fullscreen(&mut self, enabled: bool) -> &mut process::Command {
420        self.as_inner_mut().startupinfo_fullscreen(enabled);
421        self
422    }
423
424    fn startupinfo_untrusted_source(&mut self, enabled: bool) -> &mut process::Command {
425        self.as_inner_mut().startupinfo_untrusted_source(enabled);
426        self
427    }
428
429    fn startupinfo_force_feedback(&mut self, enabled: Option<bool>) -> &mut process::Command {
430        self.as_inner_mut().startupinfo_force_feedback(enabled);
431        self
432    }
433
434    fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command {
435        self.as_inner_mut().inherit_handles(inherit_handles);
436        self
437    }
438}
439
440#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
441pub impl(self) trait ChildExt {
442    /// Extracts the main thread raw handle, without taking ownership
443    #[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
444    fn main_thread_handle(&self) -> BorrowedHandle<'_>;
445}
446
447#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
448impl ChildExt for process::Child {
449    fn main_thread_handle(&self) -> BorrowedHandle<'_> {
450        self.handle.main_thread_handle()
451    }
452}
453
454/// Windows-specific extensions to [`process::ExitCode`].
455#[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
456pub impl(self) trait ExitCodeExt {
457    /// Creates a new `ExitCode` from the raw underlying `u32` return value of
458    /// a process.
459    ///
460    /// The exit code should not be 259, as this conflicts with the `STILL_ACTIVE`
461    /// macro returned from the `GetExitCodeProcess` function to signal that the
462    /// process has yet to run to completion.
463    #[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
464    fn from_raw(raw: u32) -> Self;
465}
466
467#[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
468impl ExitCodeExt for process::ExitCode {
469    fn from_raw(raw: u32) -> Self {
470        process::ExitCode::from_inner(From::from(raw))
471    }
472}
473
474/// A wrapper around windows [`ProcThreadAttributeList`][1].
475///
476/// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-initializeprocthreadattributelist>
477#[derive(Debug)]
478#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
479pub struct ProcThreadAttributeList<'a> {
480    attribute_list: Box<[MaybeUninit<u8>]>,
481    _lifetime_marker: marker::PhantomData<&'a ()>,
482}
483
484#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
485impl<'a> ProcThreadAttributeList<'a> {
486    /// Creates a new builder for constructing a [`ProcThreadAttributeList`].
487    pub fn build() -> ProcThreadAttributeListBuilder<'a> {
488        ProcThreadAttributeListBuilder::new()
489    }
490
491    /// Returns a pointer to the underling attribute list.
492    #[doc(hidden)]
493    pub fn as_ptr(&self) -> *const MaybeUninit<u8> {
494        self.attribute_list.as_ptr()
495    }
496}
497
498#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
499impl<'a> Drop for ProcThreadAttributeList<'a> {
500    /// Deletes the attribute list.
501    ///
502    /// This method calls [`DeleteProcThreadAttributeList`][1] to delete the
503    /// underlying attribute list.
504    ///
505    /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-deleteprocthreadattributelist>
506    fn drop(&mut self) {
507        let lp_attribute_list = self.attribute_list.as_mut_ptr().cast::<c_void>();
508        unsafe { sys::c::DeleteProcThreadAttributeList(lp_attribute_list) }
509    }
510}
511
512/// Builder for constructing a [`ProcThreadAttributeList`].
513#[derive(Clone, Debug)]
514#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
515pub struct ProcThreadAttributeListBuilder<'a> {
516    attributes: alloc::collections::BTreeMap<usize, ProcThreadAttributeValue>,
517    _lifetime_marker: marker::PhantomData<&'a ()>,
518}
519
520#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
521impl<'a> ProcThreadAttributeListBuilder<'a> {
522    fn new() -> Self {
523        ProcThreadAttributeListBuilder {
524            attributes: alloc::collections::BTreeMap::new(),
525            _lifetime_marker: marker::PhantomData,
526        }
527    }
528
529    /// Sets an attribute on the attribute list.
530    ///
531    /// The `attribute` parameter specifies the raw attribute to be set, while
532    /// the `value` parameter holds the value associated with that attribute.
533    /// Please refer to the [Windows documentation][1] for a list of valid attributes.
534    ///
535    /// # Note
536    ///
537    /// The maximum number of attributes is the value of [`u32::MAX`]. If this
538    /// limit is exceeded, the call to [`Self::finish`] will return an `Error`
539    /// indicating that the maximum number of attributes has been exceeded.
540    ///
541    /// # Safety Note
542    ///
543    /// Remember that improper use of attributes can lead to undefined behavior
544    /// or security vulnerabilities. Always consult the documentation and ensure
545    /// proper attribute values are used.
546    ///
547    /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-updateprocthreadattribute#parameters>
548    pub fn attribute<T>(self, attribute: usize, value: &'a T) -> Self {
549        unsafe {
550            self.raw_attribute(attribute, ptr::addr_of!(*value).cast::<c_void>(), size_of::<T>())
551        }
552    }
553
554    /// Sets a raw attribute on the attribute list.
555    ///
556    /// This function is useful for setting attributes with pointers or sizes
557    /// that cannot be derived directly from their values.
558    ///
559    /// # Safety
560    ///
561    /// This function is marked as `unsafe` because it deals with raw pointers
562    /// and sizes. It is the responsibility of the caller to ensure the value
563    /// lives longer than the resulting [`ProcThreadAttributeList`] as well as
564    /// the validity of the size parameter.
565    ///
566    /// # Example
567    ///
568    #[cfg_attr(not(windows), doc = "```ignore (needs windows)")]
569    #[cfg_attr(all(windows, target_vendor = "win7"), doc = "```no_run")]
570    #[cfg_attr(all(windows, not(target_vendor = "win7")), doc = "```")]
571    /// #![feature(windows_process_extensions_raw_attribute)]
572    /// use std::ffi::c_void;
573    /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
574    /// use std::os::windows::raw::HANDLE;
575    /// use std::process::Command;
576    ///
577    /// #[repr(C)]
578    /// pub struct COORD {
579    ///     pub X: i16,
580    ///     pub Y: i16,
581    /// }
582    ///
583    /// unsafe extern "system" {
584    ///     fn CreatePipe(
585    ///         hreadpipe: *mut HANDLE,
586    ///         hwritepipe: *mut HANDLE,
587    ///         lppipeattributes: *const c_void,
588    ///         nsize: u32,
589    ///     ) -> i32;
590    ///     fn CreatePseudoConsole(
591    ///         size: COORD,
592    ///         hinput: HANDLE,
593    ///         houtput: HANDLE,
594    ///         dwflags: u32,
595    ///         phpc: *mut isize,
596    ///     ) -> i32;
597    ///     fn CloseHandle(hobject: HANDLE) -> i32;
598    /// }
599    ///
600    /// let [mut input_read_side, mut output_write_side, mut output_read_side, mut input_write_side] =
601    ///     [unsafe { std::mem::zeroed::<HANDLE>() }; 4];
602    ///
603    /// unsafe {
604    ///     CreatePipe(&mut input_read_side, &mut input_write_side, std::ptr::null(), 0);
605    ///     CreatePipe(&mut output_read_side, &mut output_write_side, std::ptr::null(), 0);
606    /// }
607    ///
608    /// let size = COORD { X: 60, Y: 40 };
609    /// let mut h_pc = unsafe { std::mem::zeroed() };
610    /// unsafe { CreatePseudoConsole(size, input_read_side, output_write_side, 0, &mut h_pc) };
611    ///
612    /// unsafe { CloseHandle(input_read_side) };
613    /// unsafe { CloseHandle(output_write_side) };
614    ///
615    /// const PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE: usize = 131094;
616    ///
617    /// let attribute_list = unsafe {
618    ///     ProcThreadAttributeList::build()
619    ///         .raw_attribute(
620    ///             PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE,
621    ///             h_pc as *const c_void,
622    ///             size_of::<isize>(),
623    ///         )
624    ///         .finish()?
625    /// };
626    ///
627    /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
628    /// #
629    /// # child.kill()?;
630    /// # Ok::<(), std::io::Error>(())
631    /// ```
632    pub unsafe fn raw_attribute<T>(
633        mut self,
634        attribute: usize,
635        value_ptr: *const T,
636        value_size: usize,
637    ) -> Self {
638        self.attributes.insert(
639            attribute,
640            ProcThreadAttributeValue { ptr: value_ptr.cast::<c_void>(), size: value_size },
641        );
642        self
643    }
644
645    /// Finalizes the construction of the `ProcThreadAttributeList`.
646    ///
647    /// # Errors
648    ///
649    /// Returns an error if the maximum number of attributes is exceeded
650    /// or if there is an I/O error during initialization.
651    pub fn finish(&self) -> io::Result<ProcThreadAttributeList<'a>> {
652        // To initialize our ProcThreadAttributeList, we need to determine
653        // how many bytes to allocate for it. The Windows API simplifies this
654        // process by allowing us to call `InitializeProcThreadAttributeList`
655        // with a null pointer to retrieve the required size.
656        let mut required_size = 0;
657        let Ok(attribute_count) = self.attributes.len().try_into() else {
658            return Err(io::const_error!(
659                io::ErrorKind::InvalidInput,
660                "maximum number of ProcThreadAttributes exceeded",
661            ));
662        };
663        unsafe {
664            sys::c::InitializeProcThreadAttributeList(
665                ptr::null_mut(),
666                attribute_count,
667                0,
668                &mut required_size,
669            )
670        };
671
672        let mut attribute_list = vec![MaybeUninit::uninit(); required_size].into_boxed_slice();
673
674        // Once we've allocated the necessary memory, it's safe to invoke
675        // `InitializeProcThreadAttributeList` to properly initialize the list.
676        sys::cvt(unsafe {
677            sys::c::InitializeProcThreadAttributeList(
678                attribute_list.as_mut_ptr().cast::<c_void>(),
679                attribute_count,
680                0,
681                &mut required_size,
682            )
683        })?;
684
685        // # Add our attributes to the buffer.
686        // It's theoretically possible for the attribute count to exceed a u32
687        // value. Therefore, we ensure that we don't add more attributes than
688        // the buffer was initialized for.
689        for (&attribute, value) in self.attributes.iter().take(attribute_count as usize) {
690            sys::cvt(unsafe {
691                sys::c::UpdateProcThreadAttribute(
692                    attribute_list.as_mut_ptr().cast::<c_void>(),
693                    0,
694                    attribute,
695                    value.ptr,
696                    value.size,
697                    ptr::null_mut(),
698                    ptr::null_mut(),
699                )
700            })?;
701        }
702
703        Ok(ProcThreadAttributeList { attribute_list, _lifetime_marker: marker::PhantomData })
704    }
705}
706
707/// Wrapper around the value data to be used as a Process Thread Attribute.
708#[derive(Clone, Debug)]
709struct ProcThreadAttributeValue {
710    ptr: *const c_void,
711    size: usize,
712}
std/os/windows/process.rs

std/os/windows/
process.rs
