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, CanonAbi, Size, X86Call};
6use rustc_middle::ty::Ty;
7use rustc_span::Symbol;
8use rustc_target::callconv::FnAbi;
9
10use self::shims::windows::handle::{Handle, PseudoHandle};
11use crate::shims::os_str::bytes_to_os_str;
12use crate::shims::windows::*;
13use crate::*;
14
15pub fn is_dyn_sym(name: &str) -> bool {
16    // std does dynamic detection for these symbols
17    matches!(
18        name,
19        "SetThreadDescription" | "GetThreadDescription" | "WaitOnAddress" | "WakeByAddressSingle"
20    )
21}
22
23#[cfg(windows)]
24fn win_get_full_path_name<'tcx>(path: &Path) -> InterpResult<'tcx, io::Result<PathBuf>> {
25    // We are on Windows so we can simply let the host do this.
26    interp_ok(path::absolute(path))
27}
28
29#[cfg(unix)]
30#[expect(clippy::get_first, clippy::arithmetic_side_effects)]
31fn win_get_full_path_name<'tcx>(path: &Path) -> InterpResult<'tcx, io::Result<PathBuf>> {
32    use std::sync::LazyLock;
33
34    use rustc_data_structures::fx::FxHashSet;
35
36    // We are on Unix, so we need to implement parts of the logic ourselves. `path` will use `/`
37    // separators, and the result should also use `/`.
38    // See <https://chrisdenton.github.io/omnipath/Overview.html#absolute-win32-paths> for more
39    // information about Windows paths.
40    // This does not handle all corner cases correctly, see
41    // <https://github.com/rust-lang/miri/pull/4262#issuecomment-2792168853> for more cursed
42    // examples.
43    let bytes = path.as_os_str().as_encoded_bytes();
44    // If it starts with `//./` or `//?/` then this is a magic special path, we just leave it
45    // unchanged.
46    if bytes.get(0).copied() == Some(b'/')
47        && bytes.get(1).copied() == Some(b'/')
48        && matches!(bytes.get(2), Some(b'.' | b'?'))
49        && bytes.get(3).copied() == Some(b'/')
50    {
51        return interp_ok(Ok(path.into()));
52    };
53    let is_unc = bytes.starts_with(b"//");
54    // Special treatment for Windows' magic filenames: they are treated as being relative to `//./`.
55    static MAGIC_FILENAMES: LazyLock<FxHashSet<&'static str>> = LazyLock::new(|| {
56        FxHashSet::from_iter([
57            "CON", "PRN", "AUX", "NUL", "COM1", "COM2", "COM3", "COM4", "COM5", "COM6", "COM7",
58            "COM8", "COM9", "LPT1", "LPT2", "LPT3", "LPT4", "LPT5", "LPT6", "LPT7", "LPT8", "LPT9",
59        ])
60    });
61    if str::from_utf8(bytes).is_ok_and(|s| MAGIC_FILENAMES.contains(&*s.to_ascii_uppercase())) {
62        let mut result: Vec<u8> = b"//./".into();
63        result.extend(bytes);
64        return interp_ok(Ok(bytes_to_os_str(&result)?.into()));
65    }
66    // Otherwise we try to do something kind of close to what Windows does, but this is probably not
67    // right in all cases.
68    let mut result: Vec<&[u8]> = vec![]; // will be a vector of components, joined by `/`.
69    let mut bytes = bytes; // the remaining bytes to process
70    let mut stop = false;
71    while !stop {
72        // Find next component, and advance `bytes`.
73        let mut component = match bytes.iter().position(|&b| b == b'/') {
74            Some(pos) => {
75                let (component, tail) = bytes.split_at(pos);
76                bytes = &tail[1..]; // remove the `/`.
77                component
78            }
79            None => {
80                // There's no more `/`.
81                stop = true;
82                let component = bytes;
83                bytes = &[];
84                component
85            }
86        };
87        // `NUL` and only `NUL` also gets changed to be relative to `//./` later in the path.
88        // (This changed with Windows 11; previously, all magic filenames behaved like this.)
89        // Also, this does not apply to UNC paths.
90        if !is_unc && component.eq_ignore_ascii_case(b"NUL") {
91            let mut result: Vec<u8> = b"//./".into();
92            result.extend(component);
93            return interp_ok(Ok(bytes_to_os_str(&result)?.into()));
94        }
95        // Deal with `..` -- Windows handles this entirely syntactically.
96        if component == b".." {
97            // Remove previous component, unless we are at the "root" already, then just ignore the `..`.
98            let is_root = {
99                // Paths like `/C:`.
100                result.len() == 2 && matches!(result[0], []) && matches!(result[1], [_, b':'])
101            } || {
102                // Paths like `//server/share`
103                result.len() == 4 && matches!(result[0], []) && matches!(result[1], [])
104            };
105            if !is_root {
106                result.pop();
107            }
108            continue;
109        }
110        // Preserve this component.
111        // Strip trailing `.`, but preserve trailing `..`. But not for UNC paths!
112        let len = component.len();
113        if !is_unc && len >= 2 && component[len - 1] == b'.' && component[len - 2] != b'.' {
114            component = &component[..len - 1];
115        }
116        // Add this component to output.
117        result.push(component);
118    }
119    // Drive letters must be followed by a `/`.
120    if result.len() == 2 && matches!(result[0], []) && matches!(result[1], [_, b':']) {
121        result.push(&[]);
122    }
123    // Let the host `absolute` function do working-dir handling.
124    let result = result.join(&b'/');
125    interp_ok(path::absolute(bytes_to_os_str(&result)?))
126}
127
128impl<'tcx> EvalContextExt<'tcx> for crate::MiriInterpCx<'tcx> {}
129pub trait EvalContextExt<'tcx>: crate::MiriInterpCxExt<'tcx> {
130    fn emulate_foreign_item_inner(
131        &mut self,
132        link_name: Symbol,
133        abi: &FnAbi<'tcx, Ty<'tcx>>,
134        args: &[OpTy<'tcx>],
135        dest: &MPlaceTy<'tcx>,
136    ) -> InterpResult<'tcx, EmulateItemResult> {
137        let this = self.eval_context_mut();
138
139        // According to
140        // https://github.com/rust-lang/rust/blob/fb00adbdb69266f10df95a4527b767b0ad35ea48/compiler/rustc_target/src/spec/mod.rs#L2766-L2768,
141        // x86-32 Windows uses a different calling convention than other Windows targets
142        // for the "system" ABI.
143        let sys_conv = if this.tcx.sess.target.arch == "x86" {
144            CanonAbi::X86(X86Call::Stdcall)
145        } else {
146            CanonAbi::C
147        };
148
149        // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
150
151        // Windows API stubs.
152        // HANDLE = isize
153        // NTSTATUS = LONH = i32
154        // DWORD = ULONG = u32
155        // BOOL = i32
156        // BOOLEAN = u8
157        match link_name.as_str() {
158            // Environment related shims
159            "GetEnvironmentVariableW" => {
160                let [name, buf, size] = this.check_shim(abi, sys_conv, link_name, args)?;
161                let result = this.GetEnvironmentVariableW(name, buf, size)?;
162                this.write_scalar(result, dest)?;
163            }
164            "SetEnvironmentVariableW" => {
165                let [name, value] = this.check_shim(abi, sys_conv, link_name, args)?;
166                let result = this.SetEnvironmentVariableW(name, value)?;
167                this.write_scalar(result, dest)?;
168            }
169            "GetEnvironmentStringsW" => {
170                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
171                let result = this.GetEnvironmentStringsW()?;
172                this.write_pointer(result, dest)?;
173            }
174            "FreeEnvironmentStringsW" => {
175                let [env_block] = this.check_shim(abi, sys_conv, link_name, args)?;
176                let result = this.FreeEnvironmentStringsW(env_block)?;
177                this.write_scalar(result, dest)?;
178            }
179            "GetCurrentDirectoryW" => {
180                let [size, buf] = this.check_shim(abi, sys_conv, link_name, args)?;
181                let result = this.GetCurrentDirectoryW(size, buf)?;
182                this.write_scalar(result, dest)?;
183            }
184            "SetCurrentDirectoryW" => {
185                let [path] = this.check_shim(abi, sys_conv, link_name, args)?;
186                let result = this.SetCurrentDirectoryW(path)?;
187                this.write_scalar(result, dest)?;
188            }
189            "GetUserProfileDirectoryW" => {
190                let [token, buf, size] = this.check_shim(abi, sys_conv, link_name, args)?;
191                let result = this.GetUserProfileDirectoryW(token, buf, size)?;
192                this.write_scalar(result, dest)?;
193            }
194            "GetCurrentProcessId" => {
195                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
196                let result = this.GetCurrentProcessId()?;
197                this.write_scalar(result, dest)?;
198            }
199
200            // File related shims
201            "NtWriteFile" => {
202                let [
203                    handle,
204                    event,
205                    apc_routine,
206                    apc_context,
207                    io_status_block,
208                    buf,
209                    n,
210                    byte_offset,
211                    key,
212                ] = this.check_shim(abi, sys_conv, link_name, args)?;
213                this.NtWriteFile(
214                    handle,
215                    event,
216                    apc_routine,
217                    apc_context,
218                    io_status_block,
219                    buf,
220                    n,
221                    byte_offset,
222                    key,
223                    dest,
224                )?;
225            }
226            "NtReadFile" => {
227                let [
228                    handle,
229                    event,
230                    apc_routine,
231                    apc_context,
232                    io_status_block,
233                    buf,
234                    n,
235                    byte_offset,
236                    key,
237                ] = this.check_shim(abi, sys_conv, link_name, args)?;
238                this.NtReadFile(
239                    handle,
240                    event,
241                    apc_routine,
242                    apc_context,
243                    io_status_block,
244                    buf,
245                    n,
246                    byte_offset,
247                    key,
248                    dest,
249                )?;
250            }
251            "GetFullPathNameW" => {
252                let [filename, size, buffer, filepart] =
253                    this.check_shim(abi, sys_conv, link_name, args)?;
254                this.check_no_isolation("`GetFullPathNameW`")?;
255
256                let filename = this.read_pointer(filename)?;
257                let size = this.read_scalar(size)?.to_u32()?;
258                let buffer = this.read_pointer(buffer)?;
259                let filepart = this.read_pointer(filepart)?;
260
261                if !this.ptr_is_null(filepart)? {
262                    throw_unsup_format!("GetFullPathNameW: non-null `lpFilePart` is not supported");
263                }
264
265                let filename = this.read_path_from_wide_str(filename)?;
266                let result = match win_get_full_path_name(&filename)? {
267                    Err(err) => {
268                        this.set_last_error(err)?;
269                        Scalar::from_u32(0) // return zero upon failure
270                    }
271                    Ok(abs_filename) => {
272                        Scalar::from_u32(helpers::windows_check_buffer_size(
273                            this.write_path_to_wide_str(&abs_filename, buffer, size.into())?,
274                        ))
275                        // This can in fact return 0. It is up to the caller to set last_error to 0
276                        // beforehand and check it afterwards to exclude that case.
277                    }
278                };
279                this.write_scalar(result, dest)?;
280            }
281            "CreateFileW" => {
282                let [
283                    file_name,
284                    desired_access,
285                    share_mode,
286                    security_attributes,
287                    creation_disposition,
288                    flags_and_attributes,
289                    template_file,
290                ] = this.check_shim(abi, sys_conv, link_name, args)?;
291                let handle = this.CreateFileW(
292                    file_name,
293                    desired_access,
294                    share_mode,
295                    security_attributes,
296                    creation_disposition,
297                    flags_and_attributes,
298                    template_file,
299                )?;
300                this.write_scalar(handle.to_scalar(this), dest)?;
301            }
302            "GetFileInformationByHandle" => {
303                let [handle, info] = this.check_shim(abi, sys_conv, link_name, args)?;
304                let res = this.GetFileInformationByHandle(handle, info)?;
305                this.write_scalar(res, dest)?;
306            }
307            "DeleteFileW" => {
308                let [file_name] = this.check_shim(abi, sys_conv, link_name, args)?;
309                let res = this.DeleteFileW(file_name)?;
310                this.write_scalar(res, dest)?;
311            }
312            "SetFilePointerEx" => {
313                let [file, distance_to_move, new_file_pointer, move_method] =
314                    this.check_shim(abi, sys_conv, link_name, args)?;
315                let res =
316                    this.SetFilePointerEx(file, distance_to_move, new_file_pointer, move_method)?;
317                this.write_scalar(res, dest)?;
318            }
319
320            // Allocation
321            "HeapAlloc" => {
322                let [handle, flags, size] = this.check_shim(abi, sys_conv, link_name, args)?;
323                this.read_target_isize(handle)?;
324                let flags = this.read_scalar(flags)?.to_u32()?;
325                let size = this.read_target_usize(size)?;
326                const HEAP_ZERO_MEMORY: u32 = 0x00000008;
327                let init = if (flags & HEAP_ZERO_MEMORY) == HEAP_ZERO_MEMORY {
328                    AllocInit::Zero
329                } else {
330                    AllocInit::Uninit
331                };
332                // Alignment is twice the pointer size.
333                // Source: <https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heapalloc>
334                let align = this.tcx.pointer_size().bytes().strict_mul(2);
335                let ptr = this.allocate_ptr(
336                    Size::from_bytes(size),
337                    Align::from_bytes(align).unwrap(),
338                    MiriMemoryKind::WinHeap.into(),
339                    init,
340                )?;
341                this.write_pointer(ptr, dest)?;
342            }
343            "HeapFree" => {
344                let [handle, flags, ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
345                this.read_target_isize(handle)?;
346                this.read_scalar(flags)?.to_u32()?;
347                let ptr = this.read_pointer(ptr)?;
348                // "This pointer can be NULL." It doesn't say what happens then, but presumably nothing.
349                // (https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heapfree)
350                if !this.ptr_is_null(ptr)? {
351                    this.deallocate_ptr(ptr, None, MiriMemoryKind::WinHeap.into())?;
352                }
353                this.write_scalar(Scalar::from_i32(1), dest)?;
354            }
355            "HeapReAlloc" => {
356                let [handle, flags, old_ptr, size] =
357                    this.check_shim(abi, sys_conv, link_name, args)?;
358                this.read_target_isize(handle)?;
359                this.read_scalar(flags)?.to_u32()?;
360                let old_ptr = this.read_pointer(old_ptr)?;
361                let size = this.read_target_usize(size)?;
362                let align = this.tcx.pointer_size().bytes().strict_mul(2); // same as above
363                // The docs say that `old_ptr` must come from an earlier HeapAlloc or HeapReAlloc,
364                // so unlike C `realloc` we do *not* allow a NULL here.
365                // (https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heaprealloc)
366                let new_ptr = this.reallocate_ptr(
367                    old_ptr,
368                    None,
369                    Size::from_bytes(size),
370                    Align::from_bytes(align).unwrap(),
371                    MiriMemoryKind::WinHeap.into(),
372                    AllocInit::Uninit,
373                )?;
374                this.write_pointer(new_ptr, dest)?;
375            }
376            "LocalFree" => {
377                let [ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
378                let ptr = this.read_pointer(ptr)?;
379                // "If the hMem parameter is NULL, LocalFree ignores the parameter and returns NULL."
380                // (https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-localfree)
381                if !this.ptr_is_null(ptr)? {
382                    this.deallocate_ptr(ptr, None, MiriMemoryKind::WinLocal.into())?;
383                }
384                this.write_null(dest)?;
385            }
386
387            // errno
388            "SetLastError" => {
389                let [error] = this.check_shim(abi, sys_conv, link_name, args)?;
390                let error = this.read_scalar(error)?;
391                this.set_last_error(error)?;
392            }
393            "GetLastError" => {
394                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
395                let last_error = this.get_last_error()?;
396                this.write_scalar(last_error, dest)?;
397            }
398            "RtlNtStatusToDosError" => {
399                let [status] = this.check_shim(abi, sys_conv, link_name, args)?;
400                let status = this.read_scalar(status)?.to_u32()?;
401                let err = match status {
402                    // STATUS_MEDIA_WRITE_PROTECTED => ERROR_WRITE_PROTECT
403                    0xC00000A2 => 19,
404                    // STATUS_FILE_INVALID => ERROR_FILE_INVALID
405                    0xC0000098 => 1006,
406                    // STATUS_DISK_FULL => ERROR_DISK_FULL
407                    0xC000007F => 112,
408                    // STATUS_IO_DEVICE_ERROR => ERROR_IO_DEVICE
409                    0xC0000185 => 1117,
410                    // STATUS_ACCESS_DENIED => ERROR_ACCESS_DENIED
411                    0xC0000022 => 5,
412                    // Anything without an error code => ERROR_MR_MID_NOT_FOUND
413                    _ => 317,
414                };
415                this.write_scalar(Scalar::from_i32(err), dest)?;
416            }
417
418            // Querying system information
419            "GetSystemInfo" => {
420                // Also called from `page_size` crate.
421                let [system_info] = this.check_shim(abi, sys_conv, link_name, args)?;
422                let system_info =
423                    this.deref_pointer_as(system_info, this.windows_ty_layout("SYSTEM_INFO"))?;
424                // Initialize with `0`.
425                this.write_bytes_ptr(
426                    system_info.ptr(),
427                    iter::repeat_n(0u8, system_info.layout.size.bytes_usize()),
428                )?;
429                // Set selected fields.
430                this.write_int_fields_named(
431                    &[
432                        ("dwPageSize", this.machine.page_size.into()),
433                        ("dwNumberOfProcessors", this.machine.num_cpus.into()),
434                    ],
435                    &system_info,
436                )?;
437            }
438
439            // Thread-local storage
440            "TlsAlloc" => {
441                // This just creates a key; Windows does not natively support TLS destructors.
442
443                // Create key and return it.
444                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
445                let key = this.machine.tls.create_tls_key(None, dest.layout.size)?;
446                this.write_scalar(Scalar::from_uint(key, dest.layout.size), dest)?;
447            }
448            "TlsGetValue" => {
449                let [key] = this.check_shim(abi, sys_conv, link_name, args)?;
450                let key = u128::from(this.read_scalar(key)?.to_u32()?);
451                let active_thread = this.active_thread();
452                let ptr = this.machine.tls.load_tls(key, active_thread, this)?;
453                this.write_scalar(ptr, dest)?;
454            }
455            "TlsSetValue" => {
456                let [key, new_ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
457                let key = u128::from(this.read_scalar(key)?.to_u32()?);
458                let active_thread = this.active_thread();
459                let new_data = this.read_scalar(new_ptr)?;
460                this.machine.tls.store_tls(key, active_thread, new_data, &*this.tcx)?;
461
462                // Return success (`1`).
463                this.write_int(1, dest)?;
464            }
465            "TlsFree" => {
466                let [key] = this.check_shim(abi, sys_conv, link_name, args)?;
467                let key = u128::from(this.read_scalar(key)?.to_u32()?);
468                this.machine.tls.delete_tls_key(key)?;
469
470                // Return success (`1`).
471                this.write_int(1, dest)?;
472            }
473
474            // Access to command-line arguments
475            "GetCommandLineW" => {
476                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
477                this.write_pointer(
478                    this.machine.cmd_line.expect("machine must be initialized"),
479                    dest,
480                )?;
481            }
482
483            // Time related shims
484            "GetSystemTimeAsFileTime" | "GetSystemTimePreciseAsFileTime" => {
485                #[allow(non_snake_case)]
486                let [LPFILETIME] = this.check_shim(abi, sys_conv, link_name, args)?;
487                this.GetSystemTimeAsFileTime(link_name.as_str(), LPFILETIME)?;
488            }
489            "QueryPerformanceCounter" => {
490                #[allow(non_snake_case)]
491                let [lpPerformanceCount] = this.check_shim(abi, sys_conv, link_name, args)?;
492                let result = this.QueryPerformanceCounter(lpPerformanceCount)?;
493                this.write_scalar(result, dest)?;
494            }
495            "QueryPerformanceFrequency" => {
496                #[allow(non_snake_case)]
497                let [lpFrequency] = this.check_shim(abi, sys_conv, link_name, args)?;
498                let result = this.QueryPerformanceFrequency(lpFrequency)?;
499                this.write_scalar(result, dest)?;
500            }
501            "Sleep" => {
502                let [timeout] = this.check_shim(abi, sys_conv, link_name, args)?;
503
504                this.Sleep(timeout)?;
505            }
506            "CreateWaitableTimerExW" => {
507                let [attributes, name, flags, access] =
508                    this.check_shim(abi, sys_conv, link_name, args)?;
509                this.read_pointer(attributes)?;
510                this.read_pointer(name)?;
511                this.read_scalar(flags)?.to_u32()?;
512                this.read_scalar(access)?.to_u32()?;
513                // Unimplemented. Always return failure.
514                let not_supported = this.eval_windows("c", "ERROR_NOT_SUPPORTED");
515                this.set_last_error(not_supported)?;
516                this.write_null(dest)?;
517            }
518
519            // Synchronization primitives
520            "InitOnceBeginInitialize" => {
521                let [ptr, flags, pending, context] =
522                    this.check_shim(abi, sys_conv, link_name, args)?;
523                this.InitOnceBeginInitialize(ptr, flags, pending, context, dest)?;
524            }
525            "InitOnceComplete" => {
526                let [ptr, flags, context] = this.check_shim(abi, sys_conv, link_name, args)?;
527                let result = this.InitOnceComplete(ptr, flags, context)?;
528                this.write_scalar(result, dest)?;
529            }
530            "WaitOnAddress" => {
531                let [ptr_op, compare_op, size_op, timeout_op] =
532                    this.check_shim(abi, sys_conv, link_name, args)?;
533
534                this.WaitOnAddress(ptr_op, compare_op, size_op, timeout_op, dest)?;
535            }
536            "WakeByAddressSingle" => {
537                let [ptr_op] = this.check_shim(abi, sys_conv, link_name, args)?;
538
539                this.WakeByAddressSingle(ptr_op)?;
540            }
541            "WakeByAddressAll" => {
542                let [ptr_op] = this.check_shim(abi, sys_conv, link_name, args)?;
543
544                this.WakeByAddressAll(ptr_op)?;
545            }
546
547            // Dynamic symbol loading
548            "GetProcAddress" => {
549                #[allow(non_snake_case)]
550                let [hModule, lpProcName] = this.check_shim(abi, sys_conv, link_name, args)?;
551                this.read_target_isize(hModule)?;
552                let name = this.read_c_str(this.read_pointer(lpProcName)?)?;
553                if let Ok(name) = str::from_utf8(name)
554                    && is_dyn_sym(name)
555                {
556                    let ptr = this.fn_ptr(FnVal::Other(DynSym::from_str(name)));
557                    this.write_pointer(ptr, dest)?;
558                } else {
559                    this.write_null(dest)?;
560                }
561            }
562
563            // Threading
564            "CreateThread" => {
565                let [security, stacksize, start, arg, flags, thread] =
566                    this.check_shim(abi, sys_conv, link_name, args)?;
567
568                let thread_id =
569                    this.CreateThread(security, stacksize, start, arg, flags, thread)?;
570
571                this.write_scalar(Handle::Thread(thread_id).to_scalar(this), dest)?;
572            }
573            "WaitForSingleObject" => {
574                let [handle, timeout] = this.check_shim(abi, sys_conv, link_name, args)?;
575
576                this.WaitForSingleObject(handle, timeout, dest)?;
577            }
578            "GetCurrentProcess" => {
579                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
580
581                this.write_scalar(
582                    Handle::Pseudo(PseudoHandle::CurrentProcess).to_scalar(this),
583                    dest,
584                )?;
585            }
586            "GetCurrentThread" => {
587                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
588
589                this.write_scalar(
590                    Handle::Pseudo(PseudoHandle::CurrentThread).to_scalar(this),
591                    dest,
592                )?;
593            }
594            "SetThreadDescription" => {
595                let [handle, name] = this.check_shim(abi, sys_conv, link_name, args)?;
596
597                let handle = this.read_handle(handle, "SetThreadDescription")?;
598                let name = this.read_wide_str(this.read_pointer(name)?)?;
599
600                let thread = match handle {
601                    Handle::Thread(thread) => thread,
602                    Handle::Pseudo(PseudoHandle::CurrentThread) => this.active_thread(),
603                    _ => this.invalid_handle("SetThreadDescription")?,
604                };
605                // FIXME: use non-lossy conversion
606                this.set_thread_name(thread, String::from_utf16_lossy(&name).into_bytes());
607                this.write_scalar(Scalar::from_u32(0), dest)?;
608            }
609            "GetThreadDescription" => {
610                let [handle, name_ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
611
612                let handle = this.read_handle(handle, "GetThreadDescription")?;
613                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
614
615                let thread = match handle {
616                    Handle::Thread(thread) => thread,
617                    Handle::Pseudo(PseudoHandle::CurrentThread) => this.active_thread(),
618                    _ => this.invalid_handle("GetThreadDescription")?,
619                };
620                // Looks like the default thread name is empty.
621                let name = this.get_thread_name(thread).unwrap_or(b"").to_owned();
622                let name = this.alloc_os_str_as_wide_str(
623                    bytes_to_os_str(&name)?,
624                    MiriMemoryKind::WinLocal.into(),
625                )?;
626                let name = Scalar::from_maybe_pointer(name, this);
627                let res = Scalar::from_u32(0);
628
629                this.write_scalar(name, &name_ptr)?;
630                this.write_scalar(res, dest)?;
631            }
632
633            // Miscellaneous
634            "ExitProcess" => {
635                let [code] = this.check_shim(abi, sys_conv, link_name, args)?;
636                // Windows technically uses u32, but we unify everything to a Unix-style i32.
637                let code = this.read_scalar(code)?.to_i32()?;
638                throw_machine_stop!(TerminationInfo::Exit { code, leak_check: false });
639            }
640            "SystemFunction036" => {
641                // used by getrandom 0.1
642                // This is really 'RtlGenRandom'.
643                let [ptr, len] = this.check_shim(abi, sys_conv, link_name, args)?;
644                let ptr = this.read_pointer(ptr)?;
645                let len = this.read_scalar(len)?.to_u32()?;
646                this.gen_random(ptr, len.into())?;
647                this.write_scalar(Scalar::from_bool(true), dest)?;
648            }
649            "ProcessPrng" => {
650                // used by `std`
651                let [ptr, len] = this.check_shim(abi, sys_conv, link_name, args)?;
652                let ptr = this.read_pointer(ptr)?;
653                let len = this.read_target_usize(len)?;
654                this.gen_random(ptr, len)?;
655                this.write_int(1, dest)?;
656            }
657            "BCryptGenRandom" => {
658                // used by getrandom 0.2
659                let [algorithm, ptr, len, flags] =
660                    this.check_shim(abi, sys_conv, link_name, args)?;
661                let algorithm = this.read_scalar(algorithm)?;
662                let algorithm = algorithm.to_target_usize(this)?;
663                let ptr = this.read_pointer(ptr)?;
664                let len = this.read_scalar(len)?.to_u32()?;
665                let flags = this.read_scalar(flags)?.to_u32()?;
666                match flags {
667                    0 => {
668                        if algorithm != 0x81 {
669                            // BCRYPT_RNG_ALG_HANDLE
670                            throw_unsup_format!(
671                                "BCryptGenRandom algorithm must be BCRYPT_RNG_ALG_HANDLE when the flag is 0"
672                            );
673                        }
674                    }
675                    2 => {
676                        // BCRYPT_USE_SYSTEM_PREFERRED_RNG
677                        if algorithm != 0 {
678                            throw_unsup_format!(
679                                "BCryptGenRandom algorithm must be NULL when the flag is BCRYPT_USE_SYSTEM_PREFERRED_RNG"
680                            );
681                        }
682                    }
683                    _ => {
684                        throw_unsup_format!(
685                            "BCryptGenRandom is only supported with BCRYPT_USE_SYSTEM_PREFERRED_RNG or BCRYPT_RNG_ALG_HANDLE"
686                        );
687                    }
688                }
689                this.gen_random(ptr, len.into())?;
690                this.write_null(dest)?; // STATUS_SUCCESS
691            }
692            "GetConsoleScreenBufferInfo" => {
693                // `term` needs this, so we fake it.
694                let [console, buffer_info] = this.check_shim(abi, sys_conv, link_name, args)?;
695                this.read_target_isize(console)?;
696                // FIXME: this should use deref_pointer_as, but CONSOLE_SCREEN_BUFFER_INFO is not in std
697                this.deref_pointer(buffer_info)?;
698                // Indicate an error.
699                // FIXME: we should set last_error, but to what?
700                this.write_null(dest)?;
701            }
702            "GetStdHandle" => {
703                let [which] = this.check_shim(abi, sys_conv, link_name, args)?;
704                let res = this.GetStdHandle(which)?;
705                this.write_scalar(res, dest)?;
706            }
707            "DuplicateHandle" => {
708                let [src_proc, src_handle, target_proc, target_handle, access, inherit, options] =
709                    this.check_shim(abi, sys_conv, link_name, args)?;
710                let res = this.DuplicateHandle(
711                    src_proc,
712                    src_handle,
713                    target_proc,
714                    target_handle,
715                    access,
716                    inherit,
717                    options,
718                )?;
719                this.write_scalar(res, dest)?;
720            }
721            "CloseHandle" => {
722                let [handle] = this.check_shim(abi, sys_conv, link_name, args)?;
723
724                let ret = this.CloseHandle(handle)?;
725
726                this.write_scalar(ret, dest)?;
727            }
728            "GetModuleFileNameW" => {
729                let [handle, filename, size] = this.check_shim(abi, sys_conv, link_name, args)?;
730                this.check_no_isolation("`GetModuleFileNameW`")?;
731
732                let handle = this.read_handle(handle, "GetModuleFileNameW")?;
733                let filename = this.read_pointer(filename)?;
734                let size = this.read_scalar(size)?.to_u32()?;
735
736                if handle != Handle::Null {
737                    throw_unsup_format!("`GetModuleFileNameW` only supports the NULL handle");
738                }
739
740                // Using the host current_exe is a bit off, but consistent with Linux
741                // (where stdlib reads /proc/self/exe).
742                let path = std::env::current_exe().unwrap();
743                let (all_written, size_needed) =
744                    this.write_path_to_wide_str_truncated(&path, filename, size.into())?;
745
746                if all_written {
747                    // If the function succeeds, the return value is the length of the string that
748                    // is copied to the buffer, in characters, not including the terminating null
749                    // character.
750                    this.write_int(size_needed.strict_sub(1), dest)?;
751                } else {
752                    // If the buffer is too small to hold the module name, the string is truncated
753                    // to nSize characters including the terminating null character, the function
754                    // returns nSize, and the function sets the last error to
755                    // ERROR_INSUFFICIENT_BUFFER.
756                    this.write_int(size, dest)?;
757                    let insufficient_buffer = this.eval_windows("c", "ERROR_INSUFFICIENT_BUFFER");
758                    this.set_last_error(insufficient_buffer)?;
759                }
760            }
761            "FormatMessageW" => {
762                let [flags, module, message_id, language_id, buffer, size, arguments] =
763                    this.check_shim(abi, sys_conv, link_name, args)?;
764
765                let flags = this.read_scalar(flags)?.to_u32()?;
766                let _module = this.read_pointer(module)?; // seems to contain a module name
767                let message_id = this.read_scalar(message_id)?;
768                let _language_id = this.read_scalar(language_id)?.to_u32()?;
769                let buffer = this.read_pointer(buffer)?;
770                let size = this.read_scalar(size)?.to_u32()?;
771                let _arguments = this.read_pointer(arguments)?;
772
773                // We only support `FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS`
774                // This also means `arguments` can be ignored.
775                if flags != 4096u32 | 512u32 {
776                    throw_unsup_format!("FormatMessageW: unsupported flags {flags:#x}");
777                }
778
779                let error = this.try_errnum_to_io_error(message_id)?;
780                let formatted = match error {
781                    Some(err) => format!("{err}"),
782                    None => format!("<unknown error in FormatMessageW: {message_id}>"),
783                };
784                let (complete, length) =
785                    this.write_os_str_to_wide_str(OsStr::new(&formatted), buffer, size.into())?;
786                if !complete {
787                    // The API docs don't say what happens when the buffer is not big enough...
788                    // Let's just bail.
789                    throw_unsup_format!("FormatMessageW: buffer not big enough");
790                }
791                // The return value is the number of characters stored *excluding* the null terminator.
792                this.write_int(length.strict_sub(1), dest)?;
793            }
794
795            // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
796            // These shims are enabled only when the caller is in the standard library.
797            "GetProcessHeap" if this.frame_in_std() => {
798                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
799                // Just fake a HANDLE
800                // It's fine to not use the Handle type here because its a stub
801                this.write_int(1, dest)?;
802            }
803            "GetModuleHandleA" if this.frame_in_std() => {
804                #[allow(non_snake_case)]
805                let [_lpModuleName] = this.check_shim(abi, sys_conv, link_name, args)?;
806                // We need to return something non-null here to make `compat_fn!` work.
807                this.write_int(1, dest)?;
808            }
809            "SetConsoleTextAttribute" if this.frame_in_std() => {
810                #[allow(non_snake_case)]
811                let [_hConsoleOutput, _wAttribute] =
812                    this.check_shim(abi, sys_conv, link_name, args)?;
813                // Pretend these does not exist / nothing happened, by returning zero.
814                this.write_null(dest)?;
815            }
816            "GetConsoleMode" if this.frame_in_std() => {
817                let [console, mode] = this.check_shim(abi, sys_conv, link_name, args)?;
818                this.read_target_isize(console)?;
819                this.deref_pointer_as(mode, this.machine.layouts.u32)?;
820                // Indicate an error.
821                this.write_null(dest)?;
822            }
823            "GetFileType" if this.frame_in_std() => {
824                #[allow(non_snake_case)]
825                let [_hFile] = this.check_shim(abi, sys_conv, link_name, args)?;
826                // Return unknown file type.
827                this.write_null(dest)?;
828            }
829            "AddVectoredExceptionHandler" if this.frame_in_std() => {
830                #[allow(non_snake_case)]
831                let [_First, _Handler] = this.check_shim(abi, sys_conv, link_name, args)?;
832                // Any non zero value works for the stdlib. This is just used for stack overflows anyway.
833                this.write_int(1, dest)?;
834            }
835            "SetThreadStackGuarantee" if this.frame_in_std() => {
836                #[allow(non_snake_case)]
837                let [_StackSizeInBytes] = this.check_shim(abi, sys_conv, link_name, args)?;
838                // Any non zero value works for the stdlib. This is just used for stack overflows anyway.
839                this.write_int(1, dest)?;
840            }
841            // this is only callable from std because we know that std ignores the return value
842            "SwitchToThread" if this.frame_in_std() => {
843                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
844
845                this.yield_active_thread();
846
847                // FIXME: this should return a nonzero value if this call does result in switching to another thread.
848                this.write_null(dest)?;
849            }
850
851            "_Unwind_RaiseException" => {
852                // This is not formally part of POSIX, but it is very wide-spread on POSIX systems.
853                // It was originally specified as part of the Itanium C++ ABI:
854                // https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html#base-throw.
855                // MinGW implements _Unwind_RaiseException on top of SEH exceptions.
856                if this.tcx.sess.target.env != "gnu" {
857                    throw_unsup_format!(
858                        "`_Unwind_RaiseException` is not supported on non-MinGW Windows",
859                    );
860                }
861                // This function looks and behaves excatly like miri_start_unwind.
862                let [payload] = this.check_shim(abi, CanonAbi::C, link_name, args)?;
863                this.handle_miri_start_unwind(payload)?;
864                return interp_ok(EmulateItemResult::NeedsUnwind);
865            }
866
867            _ => return interp_ok(EmulateItemResult::NotSupported),
868        }
869
870        interp_ok(EmulateItemResult::NeedsReturn)
871    }
872}
miri/shims/windows/foreign_items.rs

miri/shims/windows/
foreign_items.rs
