miri/shims/windows/
foreign_items.rs

1use std::ffi::OsStr;
2use std::path::{self, Path, PathBuf};
3use std::{io, iter, str};
4
5use rustc_abi::{Align, Size};
6use rustc_middle::ty::Ty;
7use rustc_span::Symbol;
8use rustc_target::callconv::FnAbi;
9use rustc_target::spec::Env;
10
11use self::shims::windows::handle::{Handle, PseudoHandle};
12use crate::shims::os_str::bytes_to_os_str;
13use crate::shims::windows::*;
14use crate::*;
15
16pub fn is_dyn_sym(name: &str) -> bool {
17    // std does dynamic detection for these symbols
18    matches!(
19        name,
20        "SetThreadDescription" | "GetThreadDescription" | "WaitOnAddress" | "WakeByAddressSingle"
21    )
22}
23
24#[cfg(windows)]
25fn win_get_full_path_name<'tcx>(path: &Path) -> InterpResult<'tcx, io::Result<PathBuf>> {
26    // We are on Windows so we can simply let the host do this.
27    interp_ok(path::absolute(path))
28}
29
30#[cfg(unix)]
31#[expect(clippy::get_first, clippy::arithmetic_side_effects)]
32fn win_get_full_path_name<'tcx>(path: &Path) -> InterpResult<'tcx, io::Result<PathBuf>> {
33    use std::sync::LazyLock;
34
35    use rustc_data_structures::fx::FxHashSet;
36
37    // We are on Unix, so we need to implement parts of the logic ourselves. `path` will use `/`
38    // separators, and the result should also use `/`.
39    // See <https://chrisdenton.github.io/omnipath/Overview.html#absolute-win32-paths> for more
40    // information about Windows paths.
41    // This does not handle all corner cases correctly, see
42    // <https://github.com/rust-lang/miri/pull/4262#issuecomment-2792168853> for more cursed
43    // examples.
44    let bytes = path.as_os_str().as_encoded_bytes();
45    // If it starts with `//./` or `//?/` then this is a magic special path, we just leave it
46    // unchanged.
47    if bytes.get(0).copied() == Some(b'/')
48        && bytes.get(1).copied() == Some(b'/')
49        && matches!(bytes.get(2), Some(b'.' | b'?'))
50        && bytes.get(3).copied() == Some(b'/')
51    {
52        return interp_ok(Ok(path.into()));
53    };
54    let is_unc = bytes.starts_with(b"//");
55    // Special treatment for Windows' magic filenames: they are treated as being relative to `//./`.
56    static MAGIC_FILENAMES: LazyLock<FxHashSet<&'static str>> = LazyLock::new(|| {
57        FxHashSet::from_iter([
58            "CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7",
59            "COM8", "COM9", "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
60        ])
61    });
62    if str::from_utf8(bytes).is_ok_and(|s| MAGIC_FILENAMES.contains(&*s.to_ascii_uppercase())) {
63        let mut result: Vec<u8> = b"//./".into();
64        result.extend(bytes);
65        return interp_ok(Ok(bytes_to_os_str(&result)?.into()));
66    }
67    // Otherwise we try to do something kind of close to what Windows does, but this is probably not
68    // right in all cases.
69    let mut result: Vec<&[u8]> = vec![]; // will be a vector of components, joined by `/`.
70    let mut bytes = bytes; // the remaining bytes to process
71    let mut stop = false;
72    while !stop {
73        // Find next component, and advance `bytes`.
74        let mut component = match bytes.iter().position(|&b| b == b'/') {
75            Some(pos) => {
76                let (component, tail) = bytes.split_at(pos);
77                bytes = &tail[1..]; // remove the `/`.
78                component
79            }
80            None => {
81                // There's no more `/`.
82                stop = true;
83                let component = bytes;
84                bytes = &[];
85                component
86            }
87        };
88        // `NUL` and only `NUL` also gets changed to be relative to `//./` later in the path.
89        // (This changed with Windows 11; previously, all magic filenames behaved like this.)
90        // Also, this does not apply to UNC paths.
91        if !is_unc && component.eq_ignore_ascii_case(b"NUL") {
92            let mut result: Vec<u8> = b"//./".into();
93            result.extend(component);
94            return interp_ok(Ok(bytes_to_os_str(&result)?.into()));
95        }
96        // Deal with `..` -- Windows handles this entirely syntactically.
97        if component == b".." {
98            // Remove previous component, unless we are at the "root" already, then just ignore the `..`.
99            let is_root = {
100                // Paths like `/C:`.
101                result.len() == 2 && matches!(result[0], []) && matches!(result[1], [_, b':'])
102            } || {
103                // Paths like `//server/share`
104                result.len() == 4 && matches!(result[0], []) && matches!(result[1], [])
105            };
106            if !is_root {
107                result.pop();
108            }
109            continue;
110        }
111        // Preserve this component.
112        // Strip trailing `.`, but preserve trailing `..`. But not for UNC paths!
113        let len = component.len();
114        if !is_unc && len >= 2 && component[len - 1] == b'.' && component[len - 2] != b'.' {
115            component = &component[..len - 1];
116        }
117        // Add this component to output.
118        result.push(component);
119    }
120    // Drive letters must be followed by a `/`.
121    if result.len() == 2 && matches!(result[0], []) && matches!(result[1], [_, b':']) {
122        result.push(&[]);
123    }
124    // Let the host `absolute` function do working-dir handling.
125    let result = result.join(&b'/');
126    interp_ok(path::absolute(bytes_to_os_str(&result)?))
127}
128
129impl<'tcx> EvalContextExt<'tcx> for crate::MiriInterpCx<'tcx> {}
130pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
131    fn emulate_foreign_item_inner(
132        &mut self,
133        link_name: Symbol,
134        abi: &FnAbi<'tcx, Ty<'tcx>>,
135        args: &[OpTy<'tcx>],
136        dest: &MPlaceTy<'tcx>,
137    ) -> InterpResult<'tcx, EmulateItemResult> {
138        let this = self.eval_context_mut();
139
140        // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
141
142        // Windows API stubs.
143        // HANDLE = *mut c_void (formerly: isize)
144        // NTSTATUS = LONG = i32
145        // DWORD = ULONG = u32
146        // BOOL = i32
147        // BOOLEAN = u8
148        match link_name.as_str() {
149            // Environment related shims
150            "GetEnvironmentVariableW" => {
151                // FIXME: This does not have a direct test (#3179).
152                let [name, buf, size] = this.check_shim_sig(
153                    shim_sig!(extern "system" fn(*const _, *mut _, u32) -> u32),
154                    link_name,
155                    abi,
156                    args,
157                )?;
158                let result = this.GetEnvironmentVariableW(name, buf, size)?;
159                this.write_scalar(result, dest)?;
160            }
161            "SetEnvironmentVariableW" => {
162                // FIXME: This does not have a direct test (#3179).
163                let [name, value] = this.check_shim_sig(
164                    shim_sig!(extern "system" fn(*const _, *const _) -> winapi::BOOL),
165                    link_name,
166                    abi,
167                    args,
168                )?;
169                let result = this.SetEnvironmentVariableW(name, value)?;
170                this.write_scalar(result, dest)?;
171            }
172            "GetEnvironmentStringsW" => {
173                // FIXME: This does not have a direct test (#3179).
174                let [] = this.check_shim_sig(
175                    shim_sig!(extern "system" fn() -> *mut _),
176                    link_name,
177                    abi,
178                    args,
179                )?;
180                let result = this.GetEnvironmentStringsW()?;
181                this.write_pointer(result, dest)?;
182            }
183            "FreeEnvironmentStringsW" => {
184                // FIXME: This does not have a direct test (#3179).
185                let [env_block] = this.check_shim_sig(
186                    shim_sig!(extern "system" fn(*mut _) -> winapi::BOOL),
187                    link_name,
188                    abi,
189                    args,
190                )?;
191                let result = this.FreeEnvironmentStringsW(env_block)?;
192                this.write_scalar(result, dest)?;
193            }
194            "GetCurrentDirectoryW" => {
195                // FIXME: This does not have a direct test (#3179).
196                let [size, buf] = this.check_shim_sig(
197                    shim_sig!(extern "system" fn(u32, *mut _) -> u32),
198                    link_name,
199                    abi,
200                    args,
201                )?;
202                let result = this.GetCurrentDirectoryW(size, buf)?;
203                this.write_scalar(result, dest)?;
204            }
205            "SetCurrentDirectoryW" => {
206                // FIXME: This does not have a direct test (#3179).
207                let [path] = this.check_shim_sig(
208                    shim_sig!(extern "system" fn(*const _) -> winapi::BOOL),
209                    link_name,
210                    abi,
211                    args,
212                )?;
213                let result = this.SetCurrentDirectoryW(path)?;
214                this.write_scalar(result, dest)?;
215            }
216            "GetUserProfileDirectoryW" => {
217                // FIXME: This does not have a direct test (#3179).
218                let [token, buf, size] = this.check_shim_sig(
219                    shim_sig!(extern "system" fn(winapi::HANDLE, *mut _, *mut _) -> winapi::BOOL),
220                    link_name,
221                    abi,
222                    args,
223                )?;
224                let result = this.GetUserProfileDirectoryW(token, buf, size)?;
225                this.write_scalar(result, dest)?;
226            }
227            "GetCurrentProcessId" => {
228                // FIXME: This does not have a direct test (#3179).
229                let [] = this.check_shim_sig(
230                    shim_sig!(extern "system" fn() -> u32),
231                    link_name,
232                    abi,
233                    args,
234                )?;
235                let result = this.GetCurrentProcessId()?;
236                this.write_scalar(result, dest)?;
237            }
238            "GetTempPathW" => {
239                // FIXME: This does not have a direct test (#3179).
240                let [bufferlength, buffer] = this.check_shim_sig(
241                    shim_sig!(extern "system" fn(u32, *mut _) -> u32),
242                    link_name,
243                    abi,
244                    args,
245                )?;
246                let result = this.GetTempPathW(bufferlength, buffer)?;
247                this.write_scalar(result, dest)?;
248            }
249
250            // File related shims
251            "NtWriteFile" => {
252                let [
253                    handle,
254                    event,
255                    apc_routine,
256                    apc_context,
257                    io_status_block,
258                    buf,
259                    n,
260                    byte_offset,
261                    key,
262                ] = this.check_shim_sig(
263                    shim_sig!(
264                        extern "system" fn(
265                            winapi::HANDLE,
266                            winapi::HANDLE,
267                            *mut _,
268                            *mut _,
269                            *mut _,
270                            *mut _,
271                            u32,
272                            *mut _,
273                            *mut _,
274                        ) -> i32
275                    ),
276                    link_name,
277                    abi,
278                    args,
279                )?;
280                this.NtWriteFile(
281                    handle,
282                    event,
283                    apc_routine,
284                    apc_context,
285                    io_status_block,
286                    buf,
287                    n,
288                    byte_offset,
289                    key,
290                    dest,
291                )?;
292            }
293            "NtReadFile" => {
294                let [
295                    handle,
296                    event,
297                    apc_routine,
298                    apc_context,
299                    io_status_block,
300                    buf,
301                    n,
302                    byte_offset,
303                    key,
304                ] = this.check_shim_sig(
305                    shim_sig!(
306                        extern "system" fn(
307                            winapi::HANDLE,
308                            winapi::HANDLE,
309                            *mut _,
310                            *mut _,
311                            *mut _,
312                            *mut _,
313                            u32,
314                            *mut _,
315                            *mut _,
316                        ) -> i32
317                    ),
318                    link_name,
319                    abi,
320                    args,
321                )?;
322                this.NtReadFile(
323                    handle,
324                    event,
325                    apc_routine,
326                    apc_context,
327                    io_status_block,
328                    buf,
329                    n,
330                    byte_offset,
331                    key,
332                    dest,
333                )?;
334            }
335            "GetFullPathNameW" => {
336                // FIXME: This does not have a direct test (#3179).
337                let [filename, size, buffer, filepart] = this.check_shim_sig(
338                    shim_sig!(extern "system" fn(*const _, u32, *mut _, *mut _) -> u32),
339                    link_name,
340                    abi,
341                    args,
342                )?;
343                this.check_no_isolation("`GetFullPathNameW`")?;
344
345                let filename = this.read_pointer(filename)?;
346                let size = this.read_scalar(size)?.to_u32()?;
347                let buffer = this.read_pointer(buffer)?;
348                let filepart = this.read_pointer(filepart)?;
349
350                if !this.ptr_is_null(filepart)? {
351                    throw_unsup_format!("GetFullPathNameW: non-null `lpFilePart` is not supported");
352                }
353
354                let filename = this.read_path_from_wide_str(filename)?;
355                let result = match win_get_full_path_name(&filename)? {
356                    Err(err) => {
357                        this.set_last_error(err)?;
358                        Scalar::from_u32(0) // return zero upon failure
359                    }
360                    Ok(abs_filename) => {
361                        Scalar::from_u32(helpers::windows_check_buffer_size(
362                            this.write_path_to_wide_str(&abs_filename, buffer, size.into())?,
363                        ))
364                        // This can in fact return 0. It is up to the caller to set last_error to 0
365                        // beforehand and check it afterwards to exclude that case.
366                    }
367                };
368                this.write_scalar(result, dest)?;
369            }
370            "CreateFileW" => {
371                let [
372                    file_name,
373                    desired_access,
374                    share_mode,
375                    security_attributes,
376                    creation_disposition,
377                    flags_and_attributes,
378                    template_file,
379                ] = this.check_shim_sig(
380                    shim_sig!(
381                        extern "system" fn(
382                            *const _,
383                            u32,
384                            u32,
385                            *mut _,
386                            u32,
387                            u32,
388                            winapi::HANDLE,
389                        ) -> winapi::HANDLE
390                    ),
391                    link_name,
392                    abi,
393                    args,
394                )?;
395                let handle = this.CreateFileW(
396                    file_name,
397                    desired_access,
398                    share_mode,
399                    security_attributes,
400                    creation_disposition,
401                    flags_and_attributes,
402                    template_file,
403                )?;
404                this.write_scalar(handle.to_scalar(this), dest)?;
405            }
406            "GetFileInformationByHandle" => {
407                let [handle, info] = this.check_shim_sig(
408                    shim_sig!(extern "system" fn(winapi::HANDLE, *mut _) -> winapi::BOOL),
409                    link_name,
410                    abi,
411                    args,
412                )?;
413                let res = this.GetFileInformationByHandle(handle, info)?;
414                this.write_scalar(res, dest)?;
415            }
416            "SetFileInformationByHandle" => {
417                let [handle, class, info, size] = this.check_shim_sig(
418                    shim_sig!(
419                        extern "system" fn(
420                            winapi::HANDLE,
421                            winapi::FILE_INFO_BY_HANDLE_CLASS,
422                            *mut _,
423                            u32,
424                        ) -> winapi::BOOL
425                    ),
426                    link_name,
427                    abi,
428                    args,
429                )?;
430                let res = this.SetFileInformationByHandle(handle, class, info, size)?;
431                this.write_scalar(res, dest)?;
432            }
433            "FlushFileBuffers" => {
434                let [handle] = this.check_shim_sig(
435                    shim_sig!(extern "system" fn(winapi::HANDLE) -> winapi::BOOL),
436                    link_name,
437                    abi,
438                    args,
439                )?;
440                let res = this.FlushFileBuffers(handle)?;
441                this.write_scalar(res, dest)?;
442            }
443            "DeleteFileW" => {
444                let [file_name] = this.check_shim_sig(
445                    shim_sig!(extern "system" fn(*const _) -> winapi::BOOL),
446                    link_name,
447                    abi,
448                    args,
449                )?;
450                let res = this.DeleteFileW(file_name)?;
451                this.write_scalar(res, dest)?;
452            }
453            "SetFilePointerEx" => {
454                let [file, distance_to_move, new_file_pointer, move_method] = this.check_shim_sig(
455                    // i64 is actually a LARGE_INTEGER union of {u32, i32} and {i64}
456                    shim_sig!(extern "system" fn(winapi::HANDLE, i64, *mut _, u32) -> winapi::BOOL),
457                    link_name,
458                    abi,
459                    args,
460                )?;
461                let res =
462                    this.SetFilePointerEx(file, distance_to_move, new_file_pointer, move_method)?;
463                this.write_scalar(res, dest)?;
464            }
465            "MoveFileExW" => {
466                let [existing_name, new_name, flags] = this.check_shim_sig(
467                    shim_sig!(extern "system" fn(*const _, *const _, u32) -> winapi::BOOL),
468                    link_name,
469                    abi,
470                    args,
471                )?;
472                let res = this.MoveFileExW(existing_name, new_name, flags)?;
473                this.write_scalar(res, dest)?;
474            }
475
476            // Allocation
477            "HeapAlloc" => {
478                // FIXME: This does not have a direct test (#3179).
479                let [handle, flags, size] = this.check_shim_sig(
480                    shim_sig!(extern "system" fn(winapi::HANDLE, u32, usize) -> *mut _),
481                    link_name,
482                    abi,
483                    args,
484                )?;
485                this.read_target_isize(handle)?;
486                let flags = this.read_scalar(flags)?.to_u32()?;
487                let size = this.read_target_usize(size)?;
488                const HEAP_ZERO_MEMORY: u32 = 0x00000008;
489                let init = if (flags & HEAP_ZERO_MEMORY) == HEAP_ZERO_MEMORY {
490                    AllocInit::Zero
491                } else {
492                    AllocInit::Uninit
493                };
494                // Alignment is twice the pointer size.
495                // Source: <https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heapalloc>
496                let align = this.tcx.pointer_size().bytes().strict_mul(2);
497                let ptr = this.allocate_ptr(
498                    Size::from_bytes(size),
499                    Align::from_bytes(align).unwrap(),
500                    MiriMemoryKind::WinHeap.into(),
501                    init,
502                )?;
503                this.write_pointer(ptr, dest)?;
504            }
505            "HeapFree" => {
506                // FIXME: This does not have a direct test (#3179).
507                let [handle, flags, ptr] = this.check_shim_sig(
508                    shim_sig!(extern "system" fn(winapi::HANDLE, u32, *mut _) -> winapi::BOOL),
509                    link_name,
510                    abi,
511                    args,
512                )?;
513                this.read_target_isize(handle)?;
514                this.read_scalar(flags)?.to_u32()?;
515                let ptr = this.read_pointer(ptr)?;
516                // "This pointer can be NULL." It doesn't say what happens then, but presumably nothing.
517                // (https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heapfree)
518                if !this.ptr_is_null(ptr)? {
519                    this.deallocate_ptr(ptr, None, MiriMemoryKind::WinHeap.into())?;
520                }
521                this.write_scalar(Scalar::from_i32(1), dest)?;
522            }
523            "HeapReAlloc" => {
524                // FIXME: This does not have a direct test (#3179).
525                let [handle, flags, old_ptr, size] = this.check_shim_sig(
526                    shim_sig!(extern "system" fn(winapi::HANDLE, u32, *mut _, usize) -> *mut _),
527                    link_name,
528                    abi,
529                    args,
530                )?;
531                this.read_target_isize(handle)?;
532                this.read_scalar(flags)?.to_u32()?;
533                let old_ptr = this.read_pointer(old_ptr)?;
534                let size = this.read_target_usize(size)?;
535                let align = this.tcx.pointer_size().bytes().strict_mul(2); // same as above
536                // The docs say that `old_ptr` must come from an earlier HeapAlloc or HeapReAlloc,
537                // so unlike C `realloc` we do *not* allow a NULL here.
538                // (https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heaprealloc)
539                let new_ptr = this.reallocate_ptr(
540                    old_ptr,
541                    None,
542                    Size::from_bytes(size),
543                    Align::from_bytes(align).unwrap(),
544                    MiriMemoryKind::WinHeap.into(),
545                    AllocInit::Uninit,
546                )?;
547                this.write_pointer(new_ptr, dest)?;
548            }
549            "LocalFree" => {
550                // FIXME: This does not have a direct test (#3179).
551                let [ptr] = this.check_shim_sig(
552                    shim_sig!(extern "system" fn(winapi::HLOCAL) -> winapi::HLOCAL),
553                    link_name,
554                    abi,
555                    args,
556                )?;
557                let ptr = this.read_pointer(ptr)?;
558                // "If the hMem parameter is NULL, LocalFree ignores the parameter and returns NULL."
559                // (https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-localfree)
560                if !this.ptr_is_null(ptr)? {
561                    this.deallocate_ptr(ptr, None, MiriMemoryKind::WinLocal.into())?;
562                }
563                this.write_null(dest)?;
564            }
565
566            // errno
567            "SetLastError" => {
568                let [error] = this.check_shim_sig(
569                    shim_sig!(extern "system" fn(u32) -> ()),
570                    link_name,
571                    abi,
572                    args,
573                )?;
574                let error = this.read_scalar(error)?;
575                this.set_last_error(error)?;
576            }
577            "GetLastError" => {
578                let [] = this.check_shim_sig(
579                    shim_sig!(extern "system" fn() -> u32),
580                    link_name,
581                    abi,
582                    args,
583                )?;
584                let last_error = this.get_last_error()?;
585                this.write_scalar(last_error, dest)?;
586            }
587            "RtlNtStatusToDosError" => {
588                let [status] = this.check_shim_sig(
589                    shim_sig!(extern "system" fn(i32) -> u32),
590                    link_name,
591                    abi,
592                    args,
593                )?;
594                let status = this.read_scalar(status)?.to_u32()?;
595                let err = match status {
596                    // STATUS_MEDIA_WRITE_PROTECTED => ERROR_WRITE_PROTECT
597                    0xC00000A2 => 19,
598                    // STATUS_FILE_INVALID => ERROR_FILE_INVALID
599                    0xC0000098 => 1006,
600                    // STATUS_DISK_FULL => ERROR_DISK_FULL
601                    0xC000007F => 112,
602                    // STATUS_IO_DEVICE_ERROR => ERROR_IO_DEVICE
603                    0xC0000185 => 1117,
604                    // STATUS_ACCESS_DENIED => ERROR_ACCESS_DENIED
605                    0xC0000022 => 5,
606                    // Anything without an error code => ERROR_MR_MID_NOT_FOUND
607                    _ => 317,
608                };
609                this.write_scalar(Scalar::from_i32(err), dest)?;
610            }
611
612            // Querying system information
613            "GetSystemInfo" => {
614                // FIXME: This does not have a direct test (#3179).
615                // Also called from `page_size` crate.
616                let [system_info] = this.check_shim_sig(
617                    shim_sig!(extern "system" fn(*mut _) -> ()),
618                    link_name,
619                    abi,
620                    args,
621                )?;
622                let system_info =
623                    this.deref_pointer_as(system_info, this.windows_ty_layout("SYSTEM_INFO"))?;
624                // Initialize with `0`.
625                this.write_bytes_ptr(
626                    system_info.ptr(),
627                    iter::repeat_n(0u8, system_info.layout.size.bytes_usize()),
628                )?;
629                // Set selected fields.
630                this.write_int_fields_named(
631                    &[
632                        ("dwPageSize", this.machine.page_size.into()),
633                        ("dwNumberOfProcessors", this.machine.num_cpus.into()),
634                    ],
635                    &system_info,
636                )?;
637            }
638
639            // Thread-local storage
640            "TlsAlloc" => {
641                // This just creates a key; Windows does not natively support TLS destructors.
642
643                // Create key and return it.
644                let [] = this.check_shim_sig(
645                    shim_sig!(extern "system" fn() -> u32),
646                    link_name,
647                    abi,
648                    args,
649                )?;
650                let key = this.machine.tls.create_tls_key(None, dest.layout.size)?;
651                this.write_scalar(Scalar::from_uint(key, dest.layout.size), dest)?;
652            }
653            "TlsGetValue" => {
654                let [key] = this.check_shim_sig(
655                    shim_sig!(extern "system" fn(u32) -> *mut _),
656                    link_name,
657                    abi,
658                    args,
659                )?;
660                let key = u128::from(this.read_scalar(key)?.to_u32()?);
661                let active_thread = this.active_thread();
662                let ptr = this.machine.tls.load_tls(key, active_thread, this)?;
663                this.write_scalar(ptr, dest)?;
664            }
665            "TlsSetValue" => {
666                let [key, new_ptr] = this.check_shim_sig(
667                    shim_sig!(extern "system" fn(u32, *mut _) -> winapi::BOOL),
668                    link_name,
669                    abi,
670                    args,
671                )?;
672                let key = u128::from(this.read_scalar(key)?.to_u32()?);
673                let active_thread = this.active_thread();
674                let new_data = this.read_scalar(new_ptr)?;
675                this.machine.tls.store_tls(key, active_thread, new_data, &*this.tcx)?;
676
677                // Return success (`1`).
678                this.write_int(1, dest)?;
679            }
680            "TlsFree" => {
681                let [key] = this.check_shim_sig(
682                    shim_sig!(extern "system" fn(u32) -> winapi::BOOL),
683                    link_name,
684                    abi,
685                    args,
686                )?;
687                let key = u128::from(this.read_scalar(key)?.to_u32()?);
688                this.machine.tls.delete_tls_key(key)?;
689
690                // Return success (`1`).
691                this.write_int(1, dest)?;
692            }
693
694            // Access to command-line arguments
695            "GetCommandLineW" => {
696                // FIXME: This does not have a direct test (#3179).
697                let [] = this.check_shim_sig(
698                    shim_sig!(extern "system" fn() -> *mut _),
699                    link_name,
700                    abi,
701                    args,
702                )?;
703                this.write_pointer(
704                    this.machine.cmd_line.expect("machine must be initialized"),
705                    dest,
706                )?;
707            }
708
709            // Time related shims
710            "GetSystemTimeAsFileTime" | "GetSystemTimePreciseAsFileTime" => {
711                // FIXME: This does not have a direct test (#3179).
712                let [filetime] = this.check_shim_sig(
713                    shim_sig!(extern "system" fn(*mut _) -> ()),
714                    link_name,
715                    abi,
716                    args,
717                )?;
718                this.GetSystemTimeAsFileTime(link_name.as_str(), filetime)?;
719            }
720            "QueryPerformanceCounter" => {
721                // FIXME: This does not have a direct test (#3179).
722                let [performance_count] = this.check_shim_sig(
723                    shim_sig!(extern "system" fn(*mut _) -> winapi::BOOL),
724                    link_name,
725                    abi,
726                    args,
727                )?;
728                let result = this.QueryPerformanceCounter(performance_count)?;
729                this.write_scalar(result, dest)?;
730            }
731            "QueryPerformanceFrequency" => {
732                // FIXME: This does not have a direct test (#3179).
733                let [frequency] = this.check_shim_sig(
734                    shim_sig!(extern "system" fn(*mut _) -> winapi::BOOL),
735                    link_name,
736                    abi,
737                    args,
738                )?;
739                let result = this.QueryPerformanceFrequency(frequency)?;
740                this.write_scalar(result, dest)?;
741            }
742            "Sleep" => {
743                // FIXME: This does not have a direct test (#3179).
744                let [timeout] = this.check_shim_sig(
745                    shim_sig!(extern "system" fn(u32) -> ()),
746                    link_name,
747                    abi,
748                    args,
749                )?;
750
751                this.Sleep(timeout)?;
752            }
753            "CreateWaitableTimerExW" => {
754                // FIXME: This does not have a direct test (#3179).
755                let [attributes, name, flags, access] = this.check_shim_sig(
756                    shim_sig!(extern "system" fn(*mut _, *const _, u32, u32) -> winapi::HANDLE),
757                    link_name,
758                    abi,
759                    args,
760                )?;
761                this.read_pointer(attributes)?;
762                this.read_pointer(name)?;
763                this.read_scalar(flags)?.to_u32()?;
764                this.read_scalar(access)?.to_u32()?;
765                // Unimplemented. Always return failure.
766                let not_supported = this.eval_windows("c", "ERROR_NOT_SUPPORTED");
767                this.set_last_error(not_supported)?;
768                this.write_null(dest)?;
769            }
770
771            // Synchronization primitives
772            "InitOnceBeginInitialize" => {
773                let [ptr, flags, pending, context] = this.check_shim_sig(
774                    shim_sig!(extern "system" fn(*mut _, u32, *mut _, *mut _) -> winapi::BOOL),
775                    link_name,
776                    abi,
777                    args,
778                )?;
779                this.InitOnceBeginInitialize(ptr, flags, pending, context, dest)?;
780            }
781            "InitOnceComplete" => {
782                let [ptr, flags, context] = this.check_shim_sig(
783                    shim_sig!(extern "system" fn(*mut _, u32, *mut _) -> winapi::BOOL),
784                    link_name,
785                    abi,
786                    args,
787                )?;
788                let result = this.InitOnceComplete(ptr, flags, context)?;
789                this.write_scalar(result, dest)?;
790            }
791            "WaitOnAddress" => {
792                // FIXME: This does not have a direct test (#3179).
793                let [ptr_op, compare_op, size_op, timeout_op] = this.check_shim_sig(
794                    // First pointer is volatile
795                    shim_sig!(extern "system" fn(*mut _, *mut _, usize, u32) -> winapi::BOOL),
796                    link_name,
797                    abi,
798                    args,
799                )?;
800
801                this.WaitOnAddress(ptr_op, compare_op, size_op, timeout_op, dest)?;
802            }
803            "WakeByAddressSingle" => {
804                // FIXME: This does not have a direct test (#3179).
805                let [ptr_op] = this.check_shim_sig(
806                    shim_sig!(extern "system" fn(*mut _) -> ()),
807                    link_name,
808                    abi,
809                    args,
810                )?;
811
812                this.WakeByAddressSingle(ptr_op)?;
813            }
814            "WakeByAddressAll" => {
815                // FIXME: This does not have a direct test (#3179).
816                let [ptr_op] = this.check_shim_sig(
817                    shim_sig!(extern "system" fn(*mut _) -> ()),
818                    link_name,
819                    abi,
820                    args,
821                )?;
822
823                this.WakeByAddressAll(ptr_op)?;
824            }
825
826            // Dynamic symbol loading
827            "GetProcAddress" => {
828                // FIXME: This does not have a direct test (#3179).
829                let [module, proc_name] = this.check_shim_sig(
830                    shim_sig!(extern "system" fn(winapi::HMODULE, *const _) -> winapi::FARPROC),
831                    link_name,
832                    abi,
833                    args,
834                )?;
835                this.read_target_isize(module)?;
836                let name = this.read_c_str(this.read_pointer(proc_name)?)?;
837                if let Ok(name) = str::from_utf8(name)
838                    && is_dyn_sym(name)
839                {
840                    let ptr = this.fn_ptr(FnVal::Other(DynSym::from_str(name)));
841                    this.write_pointer(ptr, dest)?;
842                } else {
843                    this.write_null(dest)?;
844                }
845            }
846
847            // Threading
848            "CreateThread" => {
849                let [security, stacksize, start, arg, flags, thread] = this.check_shim_sig(
850                    shim_sig!(
851                        extern "system" fn(
852                            *mut _,
853                            usize,
854                            *mut _,
855                            *mut _,
856                            u32,
857                            *mut _,
858                        ) -> winapi::HANDLE
859                    ),
860                    link_name,
861                    abi,
862                    args,
863                )?;
864
865                let thread_id =
866                    this.CreateThread(security, stacksize, start, arg, flags, thread)?;
867
868                this.write_scalar(Handle::Thread(thread_id).to_scalar(this), dest)?;
869            }
870            "WaitForSingleObject" => {
871                let [handle, timeout] = this.check_shim_sig(
872                    shim_sig!(extern "system" fn(winapi::HANDLE, u32) -> u32),
873                    link_name,
874                    abi,
875                    args,
876                )?;
877
878                this.WaitForSingleObject(handle, timeout, dest)?;
879            }
880            "GetCurrentProcess" => {
881                let [] = this.check_shim_sig(
882                    shim_sig!(extern "system" fn() -> winapi::HANDLE),
883                    link_name,
884                    abi,
885                    args,
886                )?;
887
888                this.write_scalar(
889                    Handle::Pseudo(PseudoHandle::CurrentProcess).to_scalar(this),
890                    dest,
891                )?;
892            }
893            "GetCurrentThread" => {
894                let [] = this.check_shim_sig(
895                    shim_sig!(extern "system" fn() -> winapi::HANDLE),
896                    link_name,
897                    abi,
898                    args,
899                )?;
900
901                this.write_scalar(
902                    Handle::Pseudo(PseudoHandle::CurrentThread).to_scalar(this),
903                    dest,
904                )?;
905            }
906            "SetThreadDescription" => {
907                let [handle, name] = this.check_shim_sig(
908                    shim_sig!(extern "system" fn(winapi::HANDLE, *const _) -> i32),
909                    link_name,
910                    abi,
911                    args,
912                )?;
913
914                let handle = this.read_handle(handle, "SetThreadDescription")?;
915                let name = this.read_wide_str(this.read_pointer(name)?)?;
916
917                let thread = match handle {
918                    Handle::Thread(thread) => thread,
919                    Handle::Pseudo(PseudoHandle::CurrentThread) => this.active_thread(),
920                    _ => this.invalid_handle("SetThreadDescription")?,
921                };
922                // FIXME: use non-lossy conversion
923                this.set_thread_name(thread, String::from_utf16_lossy(&name).into_bytes());
924                this.write_scalar(Scalar::from_u32(0), dest)?;
925            }
926            "GetThreadDescription" => {
927                let [handle, name_ptr] = this.check_shim_sig(
928                    shim_sig!(extern "system" fn(winapi::HANDLE, *mut _) -> i32),
929                    link_name,
930                    abi,
931                    args,
932                )?;
933
934                let handle = this.read_handle(handle, "GetThreadDescription")?;
935                let name_ptr = this.deref_pointer_as(name_ptr, this.machine.layouts.mut_raw_ptr)?; // the pointer where we should store the ptr to the name
936
937                let thread = match handle {
938                    Handle::Thread(thread) => thread,
939                    Handle::Pseudo(PseudoHandle::CurrentThread) => this.active_thread(),
940                    _ => this.invalid_handle("GetThreadDescription")?,
941                };
942                // Looks like the default thread name is empty.
943                let name = this.get_thread_name(thread).unwrap_or(b"").to_owned();
944                let name = this.alloc_os_str_as_wide_str(
945                    bytes_to_os_str(&name)?,
946                    MiriMemoryKind::WinLocal.into(),
947                )?;
948                let name = Scalar::from_maybe_pointer(name, this);
949                let res = Scalar::from_u32(0);
950
951                this.write_scalar(name, &name_ptr)?;
952                this.write_scalar(res, dest)?;
953            }
954            "GetThreadId" => {
955                let [handle] = this.check_shim_sig(
956                    shim_sig!(extern "system" fn(winapi::HANDLE) -> u32),
957                    link_name,
958                    abi,
959                    args,
960                )?;
961                let handle = this.read_handle(handle, "GetThreadId")?;
962                let thread = match handle {
963                    Handle::Thread(thread) => thread,
964                    Handle::Pseudo(PseudoHandle::CurrentThread) => this.active_thread(),
965                    _ => this.invalid_handle("GetThreadDescription")?,
966                };
967                this.write_scalar(Scalar::from_u32(thread.to_u32()), dest)?;
968            }
969            "GetCurrentThreadId" => {
970                let [] = this.check_shim_sig(
971                    shim_sig!(extern "system" fn() -> u32),
972                    link_name,
973                    abi,
974                    args,
975                )?;
976                this.write_scalar(Scalar::from_u32(this.active_thread().to_u32()), dest)?;
977            }
978
979            // Miscellaneous
980            "ExitProcess" => {
981                // FIXME: This does not have a direct test (#3179).
982                let [code] = this.check_shim_sig(
983                    shim_sig!(extern "system" fn(u32) -> ()),
984                    link_name,
985                    abi,
986                    args,
987                )?;
988                // Windows technically uses u32, but we unify everything to a Unix-style i32.
989                let code = this.read_scalar(code)?.to_i32()?;
990                throw_machine_stop!(TerminationInfo::Exit { code, leak_check: false });
991            }
992            "SystemFunction036" => {
993                // used by getrandom 0.1
994                // This is really 'RtlGenRandom'.
995                let [ptr, len] = this.check_shim_sig(
996                    // Returns winapi::BOOLEAN, which is a byte
997                    shim_sig!(extern "system" fn(*mut _, u32) -> u8),
998                    link_name,
999                    abi,
1000                    args,
1001                )?;
1002                let ptr = this.read_pointer(ptr)?;
1003                let len = this.read_scalar(len)?.to_u32()?;
1004                this.gen_random(ptr, len.into())?;
1005                this.write_scalar(Scalar::from_bool(true), dest)?;
1006            }
1007            "ProcessPrng" => {
1008                // FIXME: This does not have a direct test (#3179).
1009                // used by `std`
1010                let [ptr, len] = this.check_shim_sig(
1011                    shim_sig!(extern "system" fn(*mut _, usize) -> winapi::BOOL),
1012                    link_name,
1013                    abi,
1014                    args,
1015                )?;
1016                let ptr = this.read_pointer(ptr)?;
1017                let len = this.read_target_usize(len)?;
1018                this.gen_random(ptr, len)?;
1019                this.write_int(1, dest)?;
1020            }
1021            "BCryptGenRandom" => {
1022                // used by getrandom 0.2
1023                let [algorithm, ptr, len, flags] = this.check_shim_sig(
1024                    shim_sig!(extern "system" fn(*mut _, *mut _, u32, u32) -> i32),
1025                    link_name,
1026                    abi,
1027                    args,
1028                )?;
1029                let algorithm = this.read_scalar(algorithm)?;
1030                let algorithm = algorithm.to_target_usize(this)?;
1031                let ptr = this.read_pointer(ptr)?;
1032                let len = this.read_scalar(len)?.to_u32()?;
1033                let flags = this.read_scalar(flags)?.to_u32()?;
1034                match flags {
1035                    0 => {
1036                        if algorithm != 0x81 {
1037                            // BCRYPT_RNG_ALG_HANDLE
1038                            throw_unsup_format!(
1039                                "BCryptGenRandom algorithm must be BCRYPT_RNG_ALG_HANDLE when the flag is 0"
1040                            );
1041                        }
1042                    }
1043                    2 => {
1044                        // BCRYPT_USE_SYSTEM_PREFERRED_RNG
1045                        if algorithm != 0 {
1046                            throw_unsup_format!(
1047                                "BCryptGenRandom algorithm must be NULL when the flag is BCRYPT_USE_SYSTEM_PREFERRED_RNG"
1048                            );
1049                        }
1050                    }
1051                    _ => {
1052                        throw_unsup_format!(
1053                            "BCryptGenRandom is only supported with BCRYPT_USE_SYSTEM_PREFERRED_RNG or BCRYPT_RNG_ALG_HANDLE"
1054                        );
1055                    }
1056                }
1057                this.gen_random(ptr, len.into())?;
1058                this.write_null(dest)?; // STATUS_SUCCESS
1059            }
1060            "GetConsoleScreenBufferInfo" => {
1061                // FIXME: This does not have a direct test (#3179).
1062                // `term` needs this, so we fake it.
1063                let [console, buffer_info] = this.check_shim_sig(
1064                    shim_sig!(extern "system" fn(winapi::HANDLE, *mut _) -> winapi::BOOL),
1065                    link_name,
1066                    abi,
1067                    args,
1068                )?;
1069                this.read_target_isize(console)?;
1070                // FIXME: this should use deref_pointer_as, but CONSOLE_SCREEN_BUFFER_INFO is not in std
1071                this.deref_pointer(buffer_info)?;
1072                // Indicate an error.
1073                // FIXME: we should set last_error, but to what?
1074                this.write_null(dest)?;
1075            }
1076            "GetStdHandle" => {
1077                // FIXME: This does not have a direct test (#3179).
1078                let [which] = this.check_shim_sig(
1079                    shim_sig!(extern "system" fn(u32) -> winapi::HANDLE),
1080                    link_name,
1081                    abi,
1082                    args,
1083                )?;
1084                let res = this.GetStdHandle(which)?;
1085                this.write_scalar(res, dest)?;
1086            }
1087            "DuplicateHandle" => {
1088                let [src_proc, src_handle, target_proc, target_handle, access, inherit, options] =
1089                    this.check_shim_sig(
1090                        shim_sig!(
1091                            extern "system" fn(
1092                                winapi::HANDLE,
1093                                winapi::HANDLE,
1094                                winapi::HANDLE,
1095                                *mut _,
1096                                u32,
1097                                winapi::BOOL,
1098                                u32,
1099                            ) -> winapi::BOOL
1100                        ),
1101                        link_name,
1102                        abi,
1103                        args,
1104                    )?;
1105                let res = this.DuplicateHandle(
1106                    src_proc,
1107                    src_handle,
1108                    target_proc,
1109                    target_handle,
1110                    access,
1111                    inherit,
1112                    options,
1113                )?;
1114                this.write_scalar(res, dest)?;
1115            }
1116            "CloseHandle" => {
1117                let [handle] = this.check_shim_sig(
1118                    shim_sig!(extern "system" fn(winapi::HANDLE) -> winapi::BOOL),
1119                    link_name,
1120                    abi,
1121                    args,
1122                )?;
1123
1124                let ret = this.CloseHandle(handle)?;
1125
1126                this.write_scalar(ret, dest)?;
1127            }
1128            "GetModuleFileNameW" => {
1129                // FIXME: This does not have a direct test (#3179).
1130                let [handle, filename, size] = this.check_shim_sig(
1131                    shim_sig!(extern "system" fn(winapi::HMODULE, *mut _, u32) -> u32),
1132                    link_name,
1133                    abi,
1134                    args,
1135                )?;
1136                this.check_no_isolation("`GetModuleFileNameW`")?;
1137
1138                let handle = this.read_handle(handle, "GetModuleFileNameW")?;
1139                let filename = this.read_pointer(filename)?;
1140                let size = this.read_scalar(size)?.to_u32()?;
1141
1142                if handle != Handle::Null {
1143                    throw_unsup_format!("`GetModuleFileNameW` only supports the NULL handle");
1144                }
1145
1146                // Using the host current_exe is a bit off, but consistent with Linux
1147                // (where stdlib reads /proc/self/exe).
1148                let path = std::env::current_exe().unwrap();
1149                let (all_written, size_needed) =
1150                    this.write_path_to_wide_str_truncated(&path, filename, size.into())?;
1151
1152                if all_written {
1153                    // If the function succeeds, the return value is the length of the string that
1154                    // is copied to the buffer, in characters, not including the terminating null
1155                    // character.
1156                    this.write_int(size_needed.strict_sub(1), dest)?;
1157                } else {
1158                    // If the buffer is too small to hold the module name, the string is truncated
1159                    // to nSize characters including the terminating null character, the function
1160                    // returns nSize, and the function sets the last error to
1161                    // ERROR_INSUFFICIENT_BUFFER.
1162                    this.write_int(size, dest)?;
1163                    let insufficient_buffer = this.eval_windows("c", "ERROR_INSUFFICIENT_BUFFER");
1164                    this.set_last_error(insufficient_buffer)?;
1165                }
1166            }
1167            "FormatMessageW" => {
1168                // FIXME: This does not have a direct test (#3179).
1169                let [flags, module, message_id, language_id, buffer, size, arguments] = this
1170                    .check_shim_sig(
1171                        shim_sig!(
1172                            extern "system" fn(u32, *const _, u32, u32, *mut _, u32, *mut _) -> u32
1173                        ),
1174                        link_name,
1175                        abi,
1176                        args,
1177                    )?;
1178
1179                let flags = this.read_scalar(flags)?.to_u32()?;
1180                let _module = this.read_pointer(module)?; // seems to contain a module name
1181                let message_id = this.read_scalar(message_id)?;
1182                let _language_id = this.read_scalar(language_id)?.to_u32()?;
1183                let buffer = this.read_pointer(buffer)?;
1184                let size = this.read_scalar(size)?.to_u32()?;
1185                let _arguments = this.read_pointer(arguments)?;
1186
1187                // We only support `FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS`
1188                // This also means `arguments` can be ignored.
1189                if flags != 4096u32 | 512u32 {
1190                    throw_unsup_format!("FormatMessageW: unsupported flags {flags:#x}");
1191                }
1192
1193                let error = this.try_errnum_to_io_error(message_id)?;
1194                let formatted = match error {
1195                    Some(err) => format!("{err}"),
1196                    None => format!("<unknown error in FormatMessageW: {message_id}>"),
1197                };
1198                let (complete, length) =
1199                    this.write_os_str_to_wide_str(OsStr::new(&formatted), buffer, size.into())?;
1200                if !complete {
1201                    // The API docs don't say what happens when the buffer is not big enough...
1202                    // Let's just bail.
1203                    throw_unsup_format!("FormatMessageW: buffer not big enough");
1204                }
1205                // The return value is the number of characters stored *excluding* the null terminator.
1206                this.write_int(length.strict_sub(1), dest)?;
1207            }
1208
1209            "_Unwind_RaiseException" => {
1210                // FIXME: This does not have a direct test (#3179).
1211                // This is not formally part of POSIX, but it is very wide-spread on POSIX systems.
1212                // It was originally specified as part of the Itanium C++ ABI:
1213                // https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html#base-throw.
1214                // MinGW implements _Unwind_RaiseException on top of SEH exceptions.
1215                if this.tcx.sess.target.env != Env::Gnu {
1216                    throw_unsup_format!(
1217                        "`_Unwind_RaiseException` is not supported on non-MinGW Windows",
1218                    );
1219                }
1220                // This function looks and behaves exactly like miri_start_unwind.
1221                let [payload] = this.check_shim_sig(
1222                    shim_sig!(extern "C" fn(*mut _) -> unwind::libunwind::_Unwind_Reason_Code),
1223                    link_name,
1224                    abi,
1225                    args,
1226                )?;
1227                this.handle_miri_start_unwind(payload)?;
1228                return interp_ok(EmulateItemResult::NeedsUnwind);
1229            }
1230
1231            // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
1232            // These shims are enabled only when the caller is in the standard library.
1233            "GetProcessHeap" if this.frame_in_std() => {
1234                let [] = this.check_shim_sig(
1235                    shim_sig!(extern "system" fn() -> winapi::HANDLE),
1236                    link_name,
1237                    abi,
1238                    args,
1239                )?;
1240                // Just fake a HANDLE
1241                // It's fine to not use the Handle type here because its a stub
1242                this.write_int(1, dest)?;
1243            }
1244            "GetModuleHandleA" if this.frame_in_std() => {
1245                let [_module_name] = this.check_shim_sig(
1246                    shim_sig!(extern "system" fn(*const _) -> winapi::HMODULE),
1247                    link_name,
1248                    abi,
1249                    args,
1250                )?;
1251                // We need to return something non-null here to make `compat_fn!` work.
1252                this.write_int(1, dest)?;
1253            }
1254            "SetConsoleTextAttribute" if this.frame_in_std() => {
1255                let [_console_output, _attribute] = this.check_shim_sig(
1256                    shim_sig!(extern "system" fn(winapi::HANDLE, u16) -> winapi::BOOL),
1257                    link_name,
1258                    abi,
1259                    args,
1260                )?;
1261                // Pretend these does not exist / nothing happened, by returning zero.
1262                this.write_null(dest)?;
1263            }
1264            "GetConsoleMode" if this.frame_in_std() => {
1265                let [console, mode] = this.check_shim_sig(
1266                    shim_sig!(extern "system" fn(winapi::HANDLE, *mut _) -> winapi::BOOL),
1267                    link_name,
1268                    abi,
1269                    args,
1270                )?;
1271                this.read_target_isize(console)?;
1272                this.deref_pointer_as(mode, this.machine.layouts.u32)?;
1273                // Indicate an error.
1274                this.write_null(dest)?;
1275            }
1276            "GetFileType" if this.frame_in_std() => {
1277                let [_file] = this.check_shim_sig(
1278                    shim_sig!(extern "system" fn(winapi::HANDLE) -> u32),
1279                    link_name,
1280                    abi,
1281                    args,
1282                )?;
1283                // Return unknown file type.
1284                this.write_null(dest)?;
1285            }
1286            "AddVectoredExceptionHandler" if this.frame_in_std() => {
1287                let [_first, _handler] = this.check_shim_sig(
1288                    shim_sig!(extern "system" fn(u32, *mut _) -> *mut _),
1289                    link_name,
1290                    abi,
1291                    args,
1292                )?;
1293                // Any non zero value works for the stdlib. This is just used for stack overflows anyway.
1294                this.write_int(1, dest)?;
1295            }
1296            "SetThreadStackGuarantee" if this.frame_in_std() => {
1297                let [_stack_size_in_bytes] = this.check_shim_sig(
1298                    shim_sig!(extern "system" fn(*mut _) -> winapi::BOOL),
1299                    link_name,
1300                    abi,
1301                    args,
1302                )?;
1303                // Any non zero value works for the stdlib. This is just used for stack overflows anyway.
1304                this.write_int(1, dest)?;
1305            }
1306            // this is only callable from std because we know that std ignores the return value
1307            "SwitchToThread" if this.frame_in_std() => {
1308                let [] = this.check_shim_sig(
1309                    shim_sig!(extern "system" fn() -> winapi::BOOL),
1310                    link_name,
1311                    abi,
1312                    args,
1313                )?;
1314
1315                this.yield_active_thread();
1316
1317                // FIXME: this should return a nonzero value if this call does result in switching to another thread.
1318                this.write_null(dest)?;
1319            }
1320
1321            _ => return interp_ok(EmulateItemResult::NotSupported),
1322        }
1323
1324        interp_ok(EmulateItemResult::NeedsReturn)
1325    }
1326}
miri/shims/windows/foreign_items.rs

miri/shims/windows/
foreign_items.rs
