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::{Conv, 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" { Conv::X86Stdcall } else { Conv::C };
144
145        // See `fn emulate_foreign_item_inner` in `shims/foreign_items.rs` for the general pattern.
146
147        // Windows API stubs.
148        // HANDLE = isize
149        // NTSTATUS = LONH = i32
150        // DWORD = ULONG = u32
151        // BOOL = i32
152        // BOOLEAN = u8
153        match link_name.as_str() {
154            // Environment related shims
155            "GetEnvironmentVariableW" => {
156                let [name, buf, size] = this.check_shim(abi, sys_conv, link_name, args)?;
157                let result = this.GetEnvironmentVariableW(name, buf, size)?;
158                this.write_scalar(result, dest)?;
159            }
160            "SetEnvironmentVariableW" => {
161                let [name, value] = this.check_shim(abi, sys_conv, link_name, args)?;
162                let result = this.SetEnvironmentVariableW(name, value)?;
163                this.write_scalar(result, dest)?;
164            }
165            "GetEnvironmentStringsW" => {
166                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
167                let result = this.GetEnvironmentStringsW()?;
168                this.write_pointer(result, dest)?;
169            }
170            "FreeEnvironmentStringsW" => {
171                let [env_block] = this.check_shim(abi, sys_conv, link_name, args)?;
172                let result = this.FreeEnvironmentStringsW(env_block)?;
173                this.write_scalar(result, dest)?;
174            }
175            "GetCurrentDirectoryW" => {
176                let [size, buf] = this.check_shim(abi, sys_conv, link_name, args)?;
177                let result = this.GetCurrentDirectoryW(size, buf)?;
178                this.write_scalar(result, dest)?;
179            }
180            "SetCurrentDirectoryW" => {
181                let [path] = this.check_shim(abi, sys_conv, link_name, args)?;
182                let result = this.SetCurrentDirectoryW(path)?;
183                this.write_scalar(result, dest)?;
184            }
185            "GetUserProfileDirectoryW" => {
186                let [token, buf, size] = this.check_shim(abi, sys_conv, link_name, args)?;
187                let result = this.GetUserProfileDirectoryW(token, buf, size)?;
188                this.write_scalar(result, dest)?;
189            }
190            "GetCurrentProcessId" => {
191                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
192                let result = this.GetCurrentProcessId()?;
193                this.write_scalar(result, dest)?;
194            }
195
196            // File related shims
197            "NtWriteFile" => {
198                let [
199                    handle,
200                    event,
201                    apc_routine,
202                    apc_context,
203                    io_status_block,
204                    buf,
205                    n,
206                    byte_offset,
207                    key,
208                ] = this.check_shim(abi, sys_conv, link_name, args)?;
209                this.NtWriteFile(
210                    handle,
211                    event,
212                    apc_routine,
213                    apc_context,
214                    io_status_block,
215                    buf,
216                    n,
217                    byte_offset,
218                    key,
219                    dest,
220                )?;
221            }
222            "NtReadFile" => {
223                let [
224                    handle,
225                    event,
226                    apc_routine,
227                    apc_context,
228                    io_status_block,
229                    buf,
230                    n,
231                    byte_offset,
232                    key,
233                ] = this.check_shim(abi, sys_conv, link_name, args)?;
234                this.NtReadFile(
235                    handle,
236                    event,
237                    apc_routine,
238                    apc_context,
239                    io_status_block,
240                    buf,
241                    n,
242                    byte_offset,
243                    key,
244                    dest,
245                )?;
246            }
247            "GetFullPathNameW" => {
248                let [filename, size, buffer, filepart] =
249                    this.check_shim(abi, sys_conv, link_name, args)?;
250                this.check_no_isolation("`GetFullPathNameW`")?;
251
252                let filename = this.read_pointer(filename)?;
253                let size = this.read_scalar(size)?.to_u32()?;
254                let buffer = this.read_pointer(buffer)?;
255                let filepart = this.read_pointer(filepart)?;
256
257                if !this.ptr_is_null(filepart)? {
258                    throw_unsup_format!("GetFullPathNameW: non-null `lpFilePart` is not supported");
259                }
260
261                let filename = this.read_path_from_wide_str(filename)?;
262                let result = match win_get_full_path_name(&filename)? {
263                    Err(err) => {
264                        this.set_last_error(err)?;
265                        Scalar::from_u32(0) // return zero upon failure
266                    }
267                    Ok(abs_filename) => {
268                        Scalar::from_u32(helpers::windows_check_buffer_size(
269                            this.write_path_to_wide_str(&abs_filename, buffer, size.into())?,
270                        ))
271                        // This can in fact return 0. It is up to the caller to set last_error to 0
272                        // beforehand and check it afterwards to exclude that case.
273                    }
274                };
275                this.write_scalar(result, dest)?;
276            }
277            "CreateFileW" => {
278                let [
279                    file_name,
280                    desired_access,
281                    share_mode,
282                    security_attributes,
283                    creation_disposition,
284                    flags_and_attributes,
285                    template_file,
286                ] = this.check_shim(abi, sys_conv, link_name, args)?;
287                let handle = this.CreateFileW(
288                    file_name,
289                    desired_access,
290                    share_mode,
291                    security_attributes,
292                    creation_disposition,
293                    flags_and_attributes,
294                    template_file,
295                )?;
296                this.write_scalar(handle.to_scalar(this), dest)?;
297            }
298            "GetFileInformationByHandle" => {
299                let [handle, info] = this.check_shim(abi, sys_conv, link_name, args)?;
300                let res = this.GetFileInformationByHandle(handle, info)?;
301                this.write_scalar(res, dest)?;
302            }
303            "DeleteFileW" => {
304                let [file_name] = this.check_shim(abi, sys_conv, link_name, args)?;
305                let res = this.DeleteFileW(file_name)?;
306                this.write_scalar(res, dest)?;
307            }
308            "SetFilePointerEx" => {
309                let [file, distance_to_move, new_file_pointer, move_method] =
310                    this.check_shim(abi, sys_conv, link_name, args)?;
311                let res =
312                    this.SetFilePointerEx(file, distance_to_move, new_file_pointer, move_method)?;
313                this.write_scalar(res, dest)?;
314            }
315
316            // Allocation
317            "HeapAlloc" => {
318                let [handle, flags, size] = this.check_shim(abi, sys_conv, link_name, args)?;
319                this.read_target_isize(handle)?;
320                let flags = this.read_scalar(flags)?.to_u32()?;
321                let size = this.read_target_usize(size)?;
322                const HEAP_ZERO_MEMORY: u32 = 0x00000008;
323                let init = if (flags & HEAP_ZERO_MEMORY) == HEAP_ZERO_MEMORY {
324                    AllocInit::Zero
325                } else {
326                    AllocInit::Uninit
327                };
328                // Alignment is twice the pointer size.
329                // Source: <https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heapalloc>
330                let align = this.tcx.pointer_size().bytes().strict_mul(2);
331                let ptr = this.allocate_ptr(
332                    Size::from_bytes(size),
333                    Align::from_bytes(align).unwrap(),
334                    MiriMemoryKind::WinHeap.into(),
335                    init,
336                )?;
337                this.write_pointer(ptr, dest)?;
338            }
339            "HeapFree" => {
340                let [handle, flags, ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
341                this.read_target_isize(handle)?;
342                this.read_scalar(flags)?.to_u32()?;
343                let ptr = this.read_pointer(ptr)?;
344                // "This pointer can be NULL." It doesn't say what happens then, but presumably nothing.
345                // (https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heapfree)
346                if !this.ptr_is_null(ptr)? {
347                    this.deallocate_ptr(ptr, None, MiriMemoryKind::WinHeap.into())?;
348                }
349                this.write_scalar(Scalar::from_i32(1), dest)?;
350            }
351            "HeapReAlloc" => {
352                let [handle, flags, old_ptr, size] =
353                    this.check_shim(abi, sys_conv, link_name, args)?;
354                this.read_target_isize(handle)?;
355                this.read_scalar(flags)?.to_u32()?;
356                let old_ptr = this.read_pointer(old_ptr)?;
357                let size = this.read_target_usize(size)?;
358                let align = this.tcx.pointer_size().bytes().strict_mul(2); // same as above
359                // The docs say that `old_ptr` must come from an earlier HeapAlloc or HeapReAlloc,
360                // so unlike C `realloc` we do *not* allow a NULL here.
361                // (https://learn.microsoft.com/en-us/windows/win32/api/heapapi/nf-heapapi-heaprealloc)
362                let new_ptr = this.reallocate_ptr(
363                    old_ptr,
364                    None,
365                    Size::from_bytes(size),
366                    Align::from_bytes(align).unwrap(),
367                    MiriMemoryKind::WinHeap.into(),
368                    AllocInit::Uninit,
369                )?;
370                this.write_pointer(new_ptr, dest)?;
371            }
372            "LocalFree" => {
373                let [ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
374                let ptr = this.read_pointer(ptr)?;
375                // "If the hMem parameter is NULL, LocalFree ignores the parameter and returns NULL."
376                // (https://learn.microsoft.com/en-us/windows/win32/api/winbase/nf-winbase-localfree)
377                if !this.ptr_is_null(ptr)? {
378                    this.deallocate_ptr(ptr, None, MiriMemoryKind::WinLocal.into())?;
379                }
380                this.write_null(dest)?;
381            }
382
383            // errno
384            "SetLastError" => {
385                let [error] = this.check_shim(abi, sys_conv, link_name, args)?;
386                let error = this.read_scalar(error)?;
387                this.set_last_error(error)?;
388            }
389            "GetLastError" => {
390                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
391                let last_error = this.get_last_error()?;
392                this.write_scalar(last_error, dest)?;
393            }
394            "RtlNtStatusToDosError" => {
395                let [status] = this.check_shim(abi, sys_conv, link_name, args)?;
396                let status = this.read_scalar(status)?.to_u32()?;
397                let err = match status {
398                    // STATUS_MEDIA_WRITE_PROTECTED => ERROR_WRITE_PROTECT
399                    0xC00000A2 => 19,
400                    // STATUS_FILE_INVALID => ERROR_FILE_INVALID
401                    0xC0000098 => 1006,
402                    // STATUS_DISK_FULL => ERROR_DISK_FULL
403                    0xC000007F => 112,
404                    // STATUS_IO_DEVICE_ERROR => ERROR_IO_DEVICE
405                    0xC0000185 => 1117,
406                    // STATUS_ACCESS_DENIED => ERROR_ACCESS_DENIED
407                    0xC0000022 => 5,
408                    // Anything without an error code => ERROR_MR_MID_NOT_FOUND
409                    _ => 317,
410                };
411                this.write_scalar(Scalar::from_i32(err), dest)?;
412            }
413
414            // Querying system information
415            "GetSystemInfo" => {
416                // Also called from `page_size` crate.
417                let [system_info] = this.check_shim(abi, sys_conv, link_name, args)?;
418                let system_info =
419                    this.deref_pointer_as(system_info, this.windows_ty_layout("SYSTEM_INFO"))?;
420                // Initialize with `0`.
421                this.write_bytes_ptr(
422                    system_info.ptr(),
423                    iter::repeat_n(0u8, system_info.layout.size.bytes_usize()),
424                )?;
425                // Set selected fields.
426                this.write_int_fields_named(
427                    &[
428                        ("dwPageSize", this.machine.page_size.into()),
429                        ("dwNumberOfProcessors", this.machine.num_cpus.into()),
430                    ],
431                    &system_info,
432                )?;
433            }
434
435            // Thread-local storage
436            "TlsAlloc" => {
437                // This just creates a key; Windows does not natively support TLS destructors.
438
439                // Create key and return it.
440                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
441                let key = this.machine.tls.create_tls_key(None, dest.layout.size)?;
442                this.write_scalar(Scalar::from_uint(key, dest.layout.size), dest)?;
443            }
444            "TlsGetValue" => {
445                let [key] = this.check_shim(abi, sys_conv, link_name, args)?;
446                let key = u128::from(this.read_scalar(key)?.to_u32()?);
447                let active_thread = this.active_thread();
448                let ptr = this.machine.tls.load_tls(key, active_thread, this)?;
449                this.write_scalar(ptr, dest)?;
450            }
451            "TlsSetValue" => {
452                let [key, new_ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
453                let key = u128::from(this.read_scalar(key)?.to_u32()?);
454                let active_thread = this.active_thread();
455                let new_data = this.read_scalar(new_ptr)?;
456                this.machine.tls.store_tls(key, active_thread, new_data, &*this.tcx)?;
457
458                // Return success (`1`).
459                this.write_int(1, dest)?;
460            }
461            "TlsFree" => {
462                let [key] = this.check_shim(abi, sys_conv, link_name, args)?;
463                let key = u128::from(this.read_scalar(key)?.to_u32()?);
464                this.machine.tls.delete_tls_key(key)?;
465
466                // Return success (`1`).
467                this.write_int(1, dest)?;
468            }
469
470            // Access to command-line arguments
471            "GetCommandLineW" => {
472                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
473                this.write_pointer(
474                    this.machine.cmd_line.expect("machine must be initialized"),
475                    dest,
476                )?;
477            }
478
479            // Time related shims
480            "GetSystemTimeAsFileTime" | "GetSystemTimePreciseAsFileTime" => {
481                #[allow(non_snake_case)]
482                let [LPFILETIME] = this.check_shim(abi, sys_conv, link_name, args)?;
483                this.GetSystemTimeAsFileTime(link_name.as_str(), LPFILETIME)?;
484            }
485            "QueryPerformanceCounter" => {
486                #[allow(non_snake_case)]
487                let [lpPerformanceCount] = this.check_shim(abi, sys_conv, link_name, args)?;
488                let result = this.QueryPerformanceCounter(lpPerformanceCount)?;
489                this.write_scalar(result, dest)?;
490            }
491            "QueryPerformanceFrequency" => {
492                #[allow(non_snake_case)]
493                let [lpFrequency] = this.check_shim(abi, sys_conv, link_name, args)?;
494                let result = this.QueryPerformanceFrequency(lpFrequency)?;
495                this.write_scalar(result, dest)?;
496            }
497            "Sleep" => {
498                let [timeout] = this.check_shim(abi, sys_conv, link_name, args)?;
499
500                this.Sleep(timeout)?;
501            }
502            "CreateWaitableTimerExW" => {
503                let [attributes, name, flags, access] =
504                    this.check_shim(abi, sys_conv, link_name, args)?;
505                this.read_pointer(attributes)?;
506                this.read_pointer(name)?;
507                this.read_scalar(flags)?.to_u32()?;
508                this.read_scalar(access)?.to_u32()?;
509                // Unimplemented. Always return failure.
510                let not_supported = this.eval_windows("c", "ERROR_NOT_SUPPORTED");
511                this.set_last_error(not_supported)?;
512                this.write_null(dest)?;
513            }
514
515            // Synchronization primitives
516            "InitOnceBeginInitialize" => {
517                let [ptr, flags, pending, context] =
518                    this.check_shim(abi, sys_conv, link_name, args)?;
519                this.InitOnceBeginInitialize(ptr, flags, pending, context, dest)?;
520            }
521            "InitOnceComplete" => {
522                let [ptr, flags, context] = this.check_shim(abi, sys_conv, link_name, args)?;
523                let result = this.InitOnceComplete(ptr, flags, context)?;
524                this.write_scalar(result, dest)?;
525            }
526            "WaitOnAddress" => {
527                let [ptr_op, compare_op, size_op, timeout_op] =
528                    this.check_shim(abi, sys_conv, link_name, args)?;
529
530                this.WaitOnAddress(ptr_op, compare_op, size_op, timeout_op, dest)?;
531            }
532            "WakeByAddressSingle" => {
533                let [ptr_op] = this.check_shim(abi, sys_conv, link_name, args)?;
534
535                this.WakeByAddressSingle(ptr_op)?;
536            }
537            "WakeByAddressAll" => {
538                let [ptr_op] = this.check_shim(abi, sys_conv, link_name, args)?;
539
540                this.WakeByAddressAll(ptr_op)?;
541            }
542
543            // Dynamic symbol loading
544            "GetProcAddress" => {
545                #[allow(non_snake_case)]
546                let [hModule, lpProcName] = this.check_shim(abi, sys_conv, link_name, args)?;
547                this.read_target_isize(hModule)?;
548                let name = this.read_c_str(this.read_pointer(lpProcName)?)?;
549                if let Ok(name) = str::from_utf8(name)
550                    && is_dyn_sym(name)
551                {
552                    let ptr = this.fn_ptr(FnVal::Other(DynSym::from_str(name)));
553                    this.write_pointer(ptr, dest)?;
554                } else {
555                    this.write_null(dest)?;
556                }
557            }
558
559            // Threading
560            "CreateThread" => {
561                let [security, stacksize, start, arg, flags, thread] =
562                    this.check_shim(abi, sys_conv, link_name, args)?;
563
564                let thread_id =
565                    this.CreateThread(security, stacksize, start, arg, flags, thread)?;
566
567                this.write_scalar(Handle::Thread(thread_id).to_scalar(this), dest)?;
568            }
569            "WaitForSingleObject" => {
570                let [handle, timeout] = this.check_shim(abi, sys_conv, link_name, args)?;
571
572                let ret = this.WaitForSingleObject(handle, timeout)?;
573                this.write_scalar(ret, dest)?;
574            }
575            "GetCurrentProcess" => {
576                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
577
578                this.write_scalar(
579                    Handle::Pseudo(PseudoHandle::CurrentProcess).to_scalar(this),
580                    dest,
581                )?;
582            }
583            "GetCurrentThread" => {
584                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
585
586                this.write_scalar(
587                    Handle::Pseudo(PseudoHandle::CurrentThread).to_scalar(this),
588                    dest,
589                )?;
590            }
591            "SetThreadDescription" => {
592                let [handle, name] = this.check_shim(abi, sys_conv, link_name, args)?;
593
594                let handle = this.read_handle(handle, "SetThreadDescription")?;
595                let name = this.read_wide_str(this.read_pointer(name)?)?;
596
597                let thread = match handle {
598                    Handle::Thread(thread) => thread,
599                    Handle::Pseudo(PseudoHandle::CurrentThread) => this.active_thread(),
600                    _ => this.invalid_handle("SetThreadDescription")?,
601                };
602                // FIXME: use non-lossy conversion
603                this.set_thread_name(thread, String::from_utf16_lossy(&name).into_bytes());
604                this.write_scalar(Scalar::from_u32(0), dest)?;
605            }
606            "GetThreadDescription" => {
607                let [handle, name_ptr] = this.check_shim(abi, sys_conv, link_name, args)?;
608
609                let handle = this.read_handle(handle, "GetThreadDescription")?;
610                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
611
612                let thread = match handle {
613                    Handle::Thread(thread) => thread,
614                    Handle::Pseudo(PseudoHandle::CurrentThread) => this.active_thread(),
615                    _ => this.invalid_handle("GetThreadDescription")?,
616                };
617                // Looks like the default thread name is empty.
618                let name = this.get_thread_name(thread).unwrap_or(b"").to_owned();
619                let name = this.alloc_os_str_as_wide_str(
620                    bytes_to_os_str(&name)?,
621                    MiriMemoryKind::WinLocal.into(),
622                )?;
623                let name = Scalar::from_maybe_pointer(name, this);
624                let res = Scalar::from_u32(0);
625
626                this.write_scalar(name, &name_ptr)?;
627                this.write_scalar(res, dest)?;
628            }
629
630            // Miscellaneous
631            "ExitProcess" => {
632                let [code] = this.check_shim(abi, sys_conv, link_name, args)?;
633                // Windows technically uses u32, but we unify everything to a Unix-style i32.
634                let code = this.read_scalar(code)?.to_i32()?;
635                throw_machine_stop!(TerminationInfo::Exit { code, leak_check: false });
636            }
637            "SystemFunction036" => {
638                // used by getrandom 0.1
639                // This is really 'RtlGenRandom'.
640                let [ptr, len] = this.check_shim(abi, sys_conv, link_name, args)?;
641                let ptr = this.read_pointer(ptr)?;
642                let len = this.read_scalar(len)?.to_u32()?;
643                this.gen_random(ptr, len.into())?;
644                this.write_scalar(Scalar::from_bool(true), dest)?;
645            }
646            "ProcessPrng" => {
647                // used by `std`
648                let [ptr, len] = this.check_shim(abi, sys_conv, link_name, args)?;
649                let ptr = this.read_pointer(ptr)?;
650                let len = this.read_target_usize(len)?;
651                this.gen_random(ptr, len)?;
652                this.write_int(1, dest)?;
653            }
654            "BCryptGenRandom" => {
655                // used by getrandom 0.2
656                let [algorithm, ptr, len, flags] =
657                    this.check_shim(abi, sys_conv, link_name, args)?;
658                let algorithm = this.read_scalar(algorithm)?;
659                let algorithm = algorithm.to_target_usize(this)?;
660                let ptr = this.read_pointer(ptr)?;
661                let len = this.read_scalar(len)?.to_u32()?;
662                let flags = this.read_scalar(flags)?.to_u32()?;
663                match flags {
664                    0 => {
665                        if algorithm != 0x81 {
666                            // BCRYPT_RNG_ALG_HANDLE
667                            throw_unsup_format!(
668                                "BCryptGenRandom algorithm must be BCRYPT_RNG_ALG_HANDLE when the flag is 0"
669                            );
670                        }
671                    }
672                    2 => {
673                        // BCRYPT_USE_SYSTEM_PREFERRED_RNG
674                        if algorithm != 0 {
675                            throw_unsup_format!(
676                                "BCryptGenRandom algorithm must be NULL when the flag is BCRYPT_USE_SYSTEM_PREFERRED_RNG"
677                            );
678                        }
679                    }
680                    _ => {
681                        throw_unsup_format!(
682                            "BCryptGenRandom is only supported with BCRYPT_USE_SYSTEM_PREFERRED_RNG or BCRYPT_RNG_ALG_HANDLE"
683                        );
684                    }
685                }
686                this.gen_random(ptr, len.into())?;
687                this.write_null(dest)?; // STATUS_SUCCESS
688            }
689            "GetConsoleScreenBufferInfo" => {
690                // `term` needs this, so we fake it.
691                let [console, buffer_info] = this.check_shim(abi, sys_conv, link_name, args)?;
692                this.read_target_isize(console)?;
693                // FIXME: this should use deref_pointer_as, but CONSOLE_SCREEN_BUFFER_INFO is not in std
694                this.deref_pointer(buffer_info)?;
695                // Indicate an error.
696                // FIXME: we should set last_error, but to what?
697                this.write_null(dest)?;
698            }
699            "GetStdHandle" => {
700                let [which] = this.check_shim(abi, sys_conv, link_name, args)?;
701                let res = this.GetStdHandle(which)?;
702                this.write_scalar(res, dest)?;
703            }
704            "DuplicateHandle" => {
705                let [src_proc, src_handle, target_proc, target_handle, access, inherit, options] =
706                    this.check_shim(abi, sys_conv, link_name, args)?;
707                let res = this.DuplicateHandle(
708                    src_proc,
709                    src_handle,
710                    target_proc,
711                    target_handle,
712                    access,
713                    inherit,
714                    options,
715                )?;
716                this.write_scalar(res, dest)?;
717            }
718            "CloseHandle" => {
719                let [handle] = this.check_shim(abi, sys_conv, link_name, args)?;
720
721                let ret = this.CloseHandle(handle)?;
722
723                this.write_scalar(ret, dest)?;
724            }
725            "GetModuleFileNameW" => {
726                let [handle, filename, size] = this.check_shim(abi, sys_conv, link_name, args)?;
727                this.check_no_isolation("`GetModuleFileNameW`")?;
728
729                let handle = this.read_handle(handle, "GetModuleFileNameW")?;
730                let filename = this.read_pointer(filename)?;
731                let size = this.read_scalar(size)?.to_u32()?;
732
733                if handle != Handle::Null {
734                    throw_unsup_format!("`GetModuleFileNameW` only supports the NULL handle");
735                }
736
737                // Using the host current_exe is a bit off, but consistent with Linux
738                // (where stdlib reads /proc/self/exe).
739                let path = std::env::current_exe().unwrap();
740                let (all_written, size_needed) =
741                    this.write_path_to_wide_str_truncated(&path, filename, size.into())?;
742
743                if all_written {
744                    // If the function succeeds, the return value is the length of the string that
745                    // is copied to the buffer, in characters, not including the terminating null
746                    // character.
747                    this.write_int(size_needed.strict_sub(1), dest)?;
748                } else {
749                    // If the buffer is too small to hold the module name, the string is truncated
750                    // to nSize characters including the terminating null character, the function
751                    // returns nSize, and the function sets the last error to
752                    // ERROR_INSUFFICIENT_BUFFER.
753                    this.write_int(size, dest)?;
754                    let insufficient_buffer = this.eval_windows("c", "ERROR_INSUFFICIENT_BUFFER");
755                    this.set_last_error(insufficient_buffer)?;
756                }
757            }
758            "FormatMessageW" => {
759                let [flags, module, message_id, language_id, buffer, size, arguments] =
760                    this.check_shim(abi, sys_conv, link_name, args)?;
761
762                let flags = this.read_scalar(flags)?.to_u32()?;
763                let _module = this.read_pointer(module)?; // seems to contain a module name
764                let message_id = this.read_scalar(message_id)?;
765                let _language_id = this.read_scalar(language_id)?.to_u32()?;
766                let buffer = this.read_pointer(buffer)?;
767                let size = this.read_scalar(size)?.to_u32()?;
768                let _arguments = this.read_pointer(arguments)?;
769
770                // We only support `FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS`
771                // This also means `arguments` can be ignored.
772                if flags != 4096u32 | 512u32 {
773                    throw_unsup_format!("FormatMessageW: unsupported flags {flags:#x}");
774                }
775
776                let error = this.try_errnum_to_io_error(message_id)?;
777                let formatted = match error {
778                    Some(err) => format!("{err}"),
779                    None => format!("<unknown error in FormatMessageW: {message_id}>"),
780                };
781                let (complete, length) =
782                    this.write_os_str_to_wide_str(OsStr::new(&formatted), buffer, size.into())?;
783                if !complete {
784                    // The API docs don't say what happens when the buffer is not big enough...
785                    // Let's just bail.
786                    throw_unsup_format!("FormatMessageW: buffer not big enough");
787                }
788                // The return value is the number of characters stored *excluding* the null terminator.
789                this.write_int(length.strict_sub(1), dest)?;
790            }
791
792            // Incomplete shims that we "stub out" just to get pre-main initialization code to work.
793            // These shims are enabled only when the caller is in the standard library.
794            "GetProcessHeap" if this.frame_in_std() => {
795                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
796                // Just fake a HANDLE
797                // It's fine to not use the Handle type here because its a stub
798                this.write_int(1, dest)?;
799            }
800            "GetModuleHandleA" if this.frame_in_std() => {
801                #[allow(non_snake_case)]
802                let [_lpModuleName] = this.check_shim(abi, sys_conv, link_name, args)?;
803                // We need to return something non-null here to make `compat_fn!` work.
804                this.write_int(1, dest)?;
805            }
806            "SetConsoleTextAttribute" if this.frame_in_std() => {
807                #[allow(non_snake_case)]
808                let [_hConsoleOutput, _wAttribute] =
809                    this.check_shim(abi, sys_conv, link_name, args)?;
810                // Pretend these does not exist / nothing happened, by returning zero.
811                this.write_null(dest)?;
812            }
813            "GetConsoleMode" if this.frame_in_std() => {
814                let [console, mode] = this.check_shim(abi, sys_conv, link_name, args)?;
815                this.read_target_isize(console)?;
816                this.deref_pointer_as(mode, this.machine.layouts.u32)?;
817                // Indicate an error.
818                this.write_null(dest)?;
819            }
820            "GetFileType" if this.frame_in_std() => {
821                #[allow(non_snake_case)]
822                let [_hFile] = this.check_shim(abi, sys_conv, link_name, args)?;
823                // Return unknown file type.
824                this.write_null(dest)?;
825            }
826            "AddVectoredExceptionHandler" if this.frame_in_std() => {
827                #[allow(non_snake_case)]
828                let [_First, _Handler] = this.check_shim(abi, sys_conv, link_name, args)?;
829                // Any non zero value works for the stdlib. This is just used for stack overflows anyway.
830                this.write_int(1, dest)?;
831            }
832            "SetThreadStackGuarantee" if this.frame_in_std() => {
833                #[allow(non_snake_case)]
834                let [_StackSizeInBytes] = this.check_shim(abi, sys_conv, link_name, args)?;
835                // Any non zero value works for the stdlib. This is just used for stack overflows anyway.
836                this.write_int(1, dest)?;
837            }
838            // this is only callable from std because we know that std ignores the return value
839            "SwitchToThread" if this.frame_in_std() => {
840                let [] = this.check_shim(abi, sys_conv, link_name, args)?;
841
842                this.yield_active_thread();
843
844                // FIXME: this should return a nonzero value if this call does result in switching to another thread.
845                this.write_null(dest)?;
846            }
847
848            "_Unwind_RaiseException" => {
849                // This is not formally part of POSIX, but it is very wide-spread on POSIX systems.
850                // It was originally specified as part of the Itanium C++ ABI:
851                // https://itanium-cxx-abi.github.io/cxx-abi/abi-eh.html#base-throw.
852                // MinGW implements _Unwind_RaiseException on top of SEH exceptions.
853                if this.tcx.sess.target.env != "gnu" {
854                    throw_unsup_format!(
855                        "`_Unwind_RaiseException` is not supported on non-MinGW Windows",
856                    );
857                }
858                // This function looks and behaves excatly like miri_start_unwind.
859                let [payload] = this.check_shim(abi, Conv::C, link_name, args)?;
860                this.handle_miri_start_unwind(payload)?;
861                return interp_ok(EmulateItemResult::NeedsUnwind);
862            }
863
864            _ => return interp_ok(EmulateItemResult::NotSupported),
865        }
866
867        interp_ok(EmulateItemResult::NeedsReturn)
868    }
869}
miri/shims/windows/foreign_items.rs

miri/shims/windows/
foreign_items.rs
