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    /// ```
277    /// #![feature(windows_process_extensions_async_pipes)]
278    /// use std::os::windows::process::CommandExt;
279    /// use std::process::{Command, Stdio};
280    ///
281    /// # let program = "";
282    ///
283    /// Command::new(program)
284    ///     .async_pipes(true)
285    ///     .stdin(Stdio::piped())
286    ///     .stdout(Stdio::piped())
287    ///     .stderr(Stdio::piped());
288    /// ```
289    #[unstable(feature = "windows_process_extensions_async_pipes", issue = "98289")]
290    fn async_pipes(&mut self, always_async: bool) -> &mut process::Command;
291
292    /// Executes the command as a child process with the given
293    /// [`ProcThreadAttributeList`], returning a handle to it.
294    ///
295    /// This method enables the customization of attributes for the spawned
296    /// child process on Windows systems.
297    /// Attributes offer extended configurability for process creation,
298    /// but their usage can be intricate and potentially unsafe.
299    ///
300    /// # Note
301    ///
302    /// By default, stdin, stdout, and stderr are inherited from the parent
303    /// process.
304    ///
305    /// # Example
306    ///
307    /// ```
308    /// #![feature(windows_process_extensions_raw_attribute)]
309    /// use std::os::windows::io::AsRawHandle;
310    /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
311    /// use std::process::Command;
312    ///
313    /// # struct ProcessDropGuard(std::process::Child);
314    /// # impl Drop for ProcessDropGuard {
315    /// #     fn drop(&mut self) {
316    /// #         let _ = self.0.kill();
317    /// #     }
318    /// # }
319    /// #
320    /// let parent = Command::new("cmd").spawn()?;
321    /// let parent_process_handle = parent.as_raw_handle();
322    /// # let parent = ProcessDropGuard(parent);
323    ///
324    /// const PROC_THREAD_ATTRIBUTE_PARENT_PROCESS: usize = 0x00020000;
325    /// let mut attribute_list = ProcThreadAttributeList::build()
326    ///     .attribute(PROC_THREAD_ATTRIBUTE_PARENT_PROCESS, &parent_process_handle)
327    ///     .finish()
328    ///     .unwrap();
329    ///
330    /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
331    /// #
332    /// # child.kill()?;
333    /// # Ok::<(), std::io::Error>(())
334    /// ```
335    #[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
336    fn spawn_with_attributes(
337        &mut self,
338        attribute_list: &ProcThreadAttributeList<'_>,
339    ) -> io::Result<process::Child>;
340
341    /// When true, sets the `STARTF_RUNFULLSCREEN` flag on the [STARTUPINFO][1] struct before passing it to `CreateProcess`.
342    ///
343    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
344    #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
345    fn startupinfo_fullscreen(&mut self, enabled: bool) -> &mut process::Command;
346
347    /// When true, sets the `STARTF_UNTRUSTEDSOURCE` flag on the [STARTUPINFO][1] struct before passing it to `CreateProcess`.
348    ///
349    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
350    #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
351    fn startupinfo_untrusted_source(&mut self, enabled: bool) -> &mut process::Command;
352
353    /// When specified, sets the following flags on the [STARTUPINFO][1] struct before passing it to `CreateProcess`:
354    /// - If `Some(true)`, sets `STARTF_FORCEONFEEDBACK`
355    /// - If `Some(false)`, sets `STARTF_FORCEOFFFEEDBACK`
356    /// - If `None`, does not set any flags
357    ///
358    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/ns-processthreadsapi-startupinfoa
359    #[unstable(feature = "windows_process_extensions_startupinfo", issue = "141010")]
360    fn startupinfo_force_feedback(&mut self, enabled: Option<bool>) -> &mut process::Command;
361
362    /// If this flag is set to `true`, each inheritable handle in the calling
363    /// process is inherited by the new process. If the flag is `false`, the
364    /// handles are not inherited.
365    ///
366    /// The default value for this flag is `true`.
367    ///
368    /// **Note** that inherited handles have the same value and access rights
369    /// as the original handles. For additional discussion of inheritable handles,
370    /// see the [Remarks][1] section of the `CreateProcessW` documentation.
371    ///
372    /// [1]: https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-createprocessw#remarks
373    #[unstable(feature = "windows_process_extensions_inherit_handles", issue = "146407")]
374    fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command;
375}
376
377#[stable(feature = "windows_process_extensions", since = "1.16.0")]
378impl CommandExt for process::Command {
379    fn creation_flags(&mut self, flags: u32) -> &mut process::Command {
380        self.as_inner_mut().creation_flags(flags);
381        self
382    }
383
384    fn show_window(&mut self, cmd_show: u16) -> &mut process::Command {
385        self.as_inner_mut().show_window(Some(cmd_show));
386        self
387    }
388
389    fn force_quotes(&mut self, enabled: bool) -> &mut process::Command {
390        self.as_inner_mut().force_quotes(enabled);
391        self
392    }
393
394    fn raw_arg<S: AsRef<OsStr>>(&mut self, raw_text: S) -> &mut process::Command {
395        self.as_inner_mut().raw_arg(raw_text.as_ref());
396        self
397    }
398
399    fn async_pipes(&mut self, always_async: bool) -> &mut process::Command {
400        // FIXME: This currently has an intentional no-op implementation.
401        // For the time being our side of the pipes will always be async.
402        // Once the ecosystem has adjusted, we may then be able to start making
403        // use of synchronous pipes within the standard library.
404        let _ = always_async;
405        self
406    }
407
408    fn spawn_with_attributes(
409        &mut self,
410        attribute_list: &ProcThreadAttributeList<'_>,
411    ) -> io::Result<process::Child> {
412        self.as_inner_mut()
413            .spawn_with_attributes(sys::process::Stdio::Inherit, true, Some(attribute_list))
414            .map(process::Child::from_inner)
415    }
416
417    fn startupinfo_fullscreen(&mut self, enabled: bool) -> &mut process::Command {
418        self.as_inner_mut().startupinfo_fullscreen(enabled);
419        self
420    }
421
422    fn startupinfo_untrusted_source(&mut self, enabled: bool) -> &mut process::Command {
423        self.as_inner_mut().startupinfo_untrusted_source(enabled);
424        self
425    }
426
427    fn startupinfo_force_feedback(&mut self, enabled: Option<bool>) -> &mut process::Command {
428        self.as_inner_mut().startupinfo_force_feedback(enabled);
429        self
430    }
431
432    fn inherit_handles(&mut self, inherit_handles: bool) -> &mut process::Command {
433        self.as_inner_mut().inherit_handles(inherit_handles);
434        self
435    }
436}
437
438#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
439pub impl(self) trait ChildExt {
440    /// Extracts the main thread raw handle, without taking ownership
441    #[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
442    fn main_thread_handle(&self) -> BorrowedHandle<'_>;
443}
444
445#[unstable(feature = "windows_process_extensions_main_thread_handle", issue = "96723")]
446impl ChildExt for process::Child {
447    fn main_thread_handle(&self) -> BorrowedHandle<'_> {
448        self.handle.main_thread_handle()
449    }
450}
451
452/// Windows-specific extensions to [`process::ExitCode`].
453#[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
454pub impl(self) trait ExitCodeExt {
455    /// Creates a new `ExitCode` from the raw underlying `u32` return value of
456    /// a process.
457    ///
458    /// The exit code should not be 259, as this conflicts with the `STILL_ACTIVE`
459    /// macro returned from the `GetExitCodeProcess` function to signal that the
460    /// process has yet to run to completion.
461    #[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
462    fn from_raw(raw: u32) -> Self;
463}
464
465#[unstable(feature = "windows_process_exit_code_from", issue = "111688")]
466impl ExitCodeExt for process::ExitCode {
467    fn from_raw(raw: u32) -> Self {
468        process::ExitCode::from_inner(From::from(raw))
469    }
470}
471
472/// A wrapper around windows [`ProcThreadAttributeList`][1].
473///
474/// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-initializeprocthreadattributelist>
475#[derive(Debug)]
476#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
477pub struct ProcThreadAttributeList<'a> {
478    attribute_list: Box<[MaybeUninit<u8>]>,
479    _lifetime_marker: marker::PhantomData<&'a ()>,
480}
481
482#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
483impl<'a> ProcThreadAttributeList<'a> {
484    /// Creates a new builder for constructing a [`ProcThreadAttributeList`].
485    pub fn build() -> ProcThreadAttributeListBuilder<'a> {
486        ProcThreadAttributeListBuilder::new()
487    }
488
489    /// Returns a pointer to the underling attribute list.
490    #[doc(hidden)]
491    pub fn as_ptr(&self) -> *const MaybeUninit<u8> {
492        self.attribute_list.as_ptr()
493    }
494}
495
496#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
497impl<'a> Drop for ProcThreadAttributeList<'a> {
498    /// Deletes the attribute list.
499    ///
500    /// This method calls [`DeleteProcThreadAttributeList`][1] to delete the
501    /// underlying attribute list.
502    ///
503    /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-deleteprocthreadattributelist>
504    fn drop(&mut self) {
505        let lp_attribute_list = self.attribute_list.as_mut_ptr().cast::<c_void>();
506        unsafe { sys::c::DeleteProcThreadAttributeList(lp_attribute_list) }
507    }
508}
509
510/// Builder for constructing a [`ProcThreadAttributeList`].
511#[derive(Clone, Debug)]
512#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
513pub struct ProcThreadAttributeListBuilder<'a> {
514    attributes: alloc::collections::BTreeMap<usize, ProcThreadAttributeValue>,
515    _lifetime_marker: marker::PhantomData<&'a ()>,
516}
517
518#[unstable(feature = "windows_process_extensions_raw_attribute", issue = "114854")]
519impl<'a> ProcThreadAttributeListBuilder<'a> {
520    fn new() -> Self {
521        ProcThreadAttributeListBuilder {
522            attributes: alloc::collections::BTreeMap::new(),
523            _lifetime_marker: marker::PhantomData,
524        }
525    }
526
527    /// Sets an attribute on the attribute list.
528    ///
529    /// The `attribute` parameter specifies the raw attribute to be set, while
530    /// the `value` parameter holds the value associated with that attribute.
531    /// Please refer to the [Windows documentation][1] for a list of valid attributes.
532    ///
533    /// # Note
534    ///
535    /// The maximum number of attributes is the value of [`u32::MAX`]. If this
536    /// limit is exceeded, the call to [`Self::finish`] will return an `Error`
537    /// indicating that the maximum number of attributes has been exceeded.
538    ///
539    /// # Safety Note
540    ///
541    /// Remember that improper use of attributes can lead to undefined behavior
542    /// or security vulnerabilities. Always consult the documentation and ensure
543    /// proper attribute values are used.
544    ///
545    /// [1]: <https://learn.microsoft.com/en-us/windows/win32/api/processthreadsapi/nf-processthreadsapi-updateprocthreadattribute#parameters>
546    pub fn attribute<T>(self, attribute: usize, value: &'a T) -> Self {
547        unsafe {
548            self.raw_attribute(attribute, ptr::addr_of!(*value).cast::<c_void>(), size_of::<T>())
549        }
550    }
551
552    /// Sets a raw attribute on the attribute list.
553    ///
554    /// This function is useful for setting attributes with pointers or sizes
555    /// that cannot be derived directly from their values.
556    ///
557    /// # Safety
558    ///
559    /// This function is marked as `unsafe` because it deals with raw pointers
560    /// and sizes. It is the responsibility of the caller to ensure the value
561    /// lives longer than the resulting [`ProcThreadAttributeList`] as well as
562    /// the validity of the size parameter.
563    ///
564    /// # Example
565    ///
566    #[cfg_attr(target_vendor = "win7", doc = "```no_run")]
567    #[cfg_attr(not(target_vendor = "win7"), doc = "```")]
568    /// #![feature(windows_process_extensions_raw_attribute)]
569    /// use std::ffi::c_void;
570    /// use std::os::windows::process::{CommandExt, ProcThreadAttributeList};
571    /// use std::os::windows::raw::HANDLE;
572    /// use std::process::Command;
573    ///
574    /// #[repr(C)]
575    /// pub struct COORD {
576    ///     pub X: i16,
577    ///     pub Y: i16,
578    /// }
579    ///
580    /// unsafe extern "system" {
581    ///     fn CreatePipe(
582    ///         hreadpipe: *mut HANDLE,
583    ///         hwritepipe: *mut HANDLE,
584    ///         lppipeattributes: *const c_void,
585    ///         nsize: u32,
586    ///     ) -> i32;
587    ///     fn CreatePseudoConsole(
588    ///         size: COORD,
589    ///         hinput: HANDLE,
590    ///         houtput: HANDLE,
591    ///         dwflags: u32,
592    ///         phpc: *mut isize,
593    ///     ) -> i32;
594    ///     fn CloseHandle(hobject: HANDLE) -> i32;
595    /// }
596    ///
597    /// let [mut input_read_side, mut output_write_side, mut output_read_side, mut input_write_side] =
598    ///     [unsafe { std::mem::zeroed::<HANDLE>() }; 4];
599    ///
600    /// unsafe {
601    ///     CreatePipe(&mut input_read_side, &mut input_write_side, std::ptr::null(), 0);
602    ///     CreatePipe(&mut output_read_side, &mut output_write_side, std::ptr::null(), 0);
603    /// }
604    ///
605    /// let size = COORD { X: 60, Y: 40 };
606    /// let mut h_pc = unsafe { std::mem::zeroed() };
607    /// unsafe { CreatePseudoConsole(size, input_read_side, output_write_side, 0, &mut h_pc) };
608    ///
609    /// unsafe { CloseHandle(input_read_side) };
610    /// unsafe { CloseHandle(output_write_side) };
611    ///
612    /// const PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE: usize = 131094;
613    ///
614    /// let attribute_list = unsafe {
615    ///     ProcThreadAttributeList::build()
616    ///         .raw_attribute(
617    ///             PROC_THREAD_ATTRIBUTE_PSEUDOCONSOLE,
618    ///             h_pc as *const c_void,
619    ///             size_of::<isize>(),
620    ///         )
621    ///         .finish()?
622    /// };
623    ///
624    /// let mut child = Command::new("cmd").spawn_with_attributes(&attribute_list)?;
625    /// #
626    /// # child.kill()?;
627    /// # Ok::<(), std::io::Error>(())
628    /// ```
629    pub unsafe fn raw_attribute<T>(
630        mut self,
631        attribute: usize,
632        value_ptr: *const T,
633        value_size: usize,
634    ) -> Self {
635        self.attributes.insert(
636            attribute,
637            ProcThreadAttributeValue { ptr: value_ptr.cast::<c_void>(), size: value_size },
638        );
639        self
640    }
641
642    /// Finalizes the construction of the `ProcThreadAttributeList`.
643    ///
644    /// # Errors
645    ///
646    /// Returns an error if the maximum number of attributes is exceeded
647    /// or if there is an I/O error during initialization.
648    pub fn finish(&self) -> io::Result<ProcThreadAttributeList<'a>> {
649        // To initialize our ProcThreadAttributeList, we need to determine
650        // how many bytes to allocate for it. The Windows API simplifies this
651        // process by allowing us to call `InitializeProcThreadAttributeList`
652        // with a null pointer to retrieve the required size.
653        let mut required_size = 0;
654        let Ok(attribute_count) = self.attributes.len().try_into() else {
655            return Err(io::const_error!(
656                io::ErrorKind::InvalidInput,
657                "maximum number of ProcThreadAttributes exceeded",
658            ));
659        };
660        unsafe {
661            sys::c::InitializeProcThreadAttributeList(
662                ptr::null_mut(),
663                attribute_count,
664                0,
665                &mut required_size,
666            )
667        };
668
669        let mut attribute_list = vec![MaybeUninit::uninit(); required_size].into_boxed_slice();
670
671        // Once we've allocated the necessary memory, it's safe to invoke
672        // `InitializeProcThreadAttributeList` to properly initialize the list.
673        sys::cvt(unsafe {
674            sys::c::InitializeProcThreadAttributeList(
675                attribute_list.as_mut_ptr().cast::<c_void>(),
676                attribute_count,
677                0,
678                &mut required_size,
679            )
680        })?;
681
682        // # Add our attributes to the buffer.
683        // It's theoretically possible for the attribute count to exceed a u32
684        // value. Therefore, we ensure that we don't add more attributes than
685        // the buffer was initialized for.
686        for (&attribute, value) in self.attributes.iter().take(attribute_count as usize) {
687            sys::cvt(unsafe {
688                sys::c::UpdateProcThreadAttribute(
689                    attribute_list.as_mut_ptr().cast::<c_void>(),
690                    0,
691                    attribute,
692                    value.ptr,
693                    value.size,
694                    ptr::null_mut(),
695                    ptr::null_mut(),
696                )
697            })?;
698        }
699
700        Ok(ProcThreadAttributeList { attribute_list, _lifetime_marker: marker::PhantomData })
701    }
702}
703
704/// Wrapper around the value data to be used as a Process Thread Attribute.
705#[derive(Clone, Debug)]
706struct ProcThreadAttributeValue {
707    ptr: *const c_void,
708    size: usize,
709}
std/os/windows/process.rs

std/os/windows/
process.rs
