4 use std::num::NonZeroUsize;
5 use std::time::Duration;
9 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX};
10 use rustc_middle::mir;
11 use rustc_middle::ty::{
13 layout::{LayoutOf, TyAndLayout},
16 use rustc_span::{def_id::CrateNum, sym, Span, Symbol};
17 use rustc_target::abi::{Align, FieldsShape, Size, Variants};
18 use rustc_target::spec::abi::Abi;
24 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
26 const UNIX_IO_ERROR_TABLE: &[(std::io::ErrorKind, &str)] = {
27 use std::io::ErrorKind::*;
29 (ConnectionRefused, "ECONNREFUSED"),
30 (ConnectionReset, "ECONNRESET"),
31 (PermissionDenied, "EPERM"),
32 (BrokenPipe, "EPIPE"),
33 (NotConnected, "ENOTCONN"),
34 (ConnectionAborted, "ECONNABORTED"),
35 (AddrNotAvailable, "EADDRNOTAVAIL"),
36 (AddrInUse, "EADDRINUSE"),
38 (Interrupted, "EINTR"),
39 (InvalidInput, "EINVAL"),
40 (TimedOut, "ETIMEDOUT"),
41 (AlreadyExists, "EEXIST"),
42 (WouldBlock, "EWOULDBLOCK"),
43 (DirectoryNotEmpty, "ENOTEMPTY"),
47 /// Gets an instance for a path.
48 fn try_resolve_did<'tcx>(tcx: TyCtxt<'tcx>, path: &[&str]) -> Option<DefId> {
49 tcx.crates(()).iter().find(|&&krate| tcx.crate_name(krate).as_str() == path[0]).and_then(
51 let krate = DefId { krate: *krate, index: CRATE_DEF_INDEX };
52 let mut items = tcx.module_children(krate);
53 let mut path_it = path.iter().skip(1).peekable();
55 while let Some(segment) = path_it.next() {
56 for item in mem::take(&mut items).iter() {
57 if item.ident.name.as_str() == *segment {
58 if path_it.peek().is_none() {
59 return Some(item.res.def_id());
62 items = tcx.module_children(item.res.def_id());
72 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
73 /// Gets an instance for a path; fails gracefully if the path does not exist.
74 fn try_resolve_path(&self, path: &[&str]) -> Option<ty::Instance<'tcx>> {
75 let did = try_resolve_did(self.eval_context_ref().tcx.tcx, path)?;
76 Some(ty::Instance::mono(self.eval_context_ref().tcx.tcx, did))
79 /// Gets an instance for a path.
80 fn resolve_path(&self, path: &[&str]) -> ty::Instance<'tcx> {
81 self.try_resolve_path(path)
82 .unwrap_or_else(|| panic!("failed to find required Rust item: {:?}", path))
85 /// Evaluates the scalar at the specified path. Returns Some(val)
86 /// if the path could be resolved, and None otherwise
87 fn eval_path_scalar(&self, path: &[&str]) -> InterpResult<'tcx, Scalar<Provenance>> {
88 let this = self.eval_context_ref();
89 let instance = this.resolve_path(path);
90 let cid = GlobalId { instance, promoted: None };
91 let const_val = this.eval_to_allocation(cid)?;
92 let const_val = this.read_scalar(&const_val.into())?;
93 const_val.check_init()
96 /// Helper function to get a `libc` constant as a `Scalar`.
97 fn eval_libc(&self, name: &str) -> InterpResult<'tcx, Scalar<Provenance>> {
98 self.eval_path_scalar(&["libc", name])
101 /// Helper function to get a `libc` constant as an `i32`.
102 fn eval_libc_i32(&self, name: &str) -> InterpResult<'tcx, i32> {
103 // TODO: Cache the result.
104 self.eval_libc(name)?.to_i32()
107 /// Helper function to get a `windows` constant as a `Scalar`.
108 fn eval_windows(&self, module: &str, name: &str) -> InterpResult<'tcx, Scalar<Provenance>> {
109 self.eval_context_ref().eval_path_scalar(&["std", "sys", "windows", module, name])
112 /// Helper function to get a `windows` constant as a `u64`.
113 fn eval_windows_u64(&self, module: &str, name: &str) -> InterpResult<'tcx, u64> {
114 // TODO: Cache the result.
115 self.eval_windows(module, name)?.to_u64()
118 /// Helper function to get the `TyAndLayout` of a `libc` type
119 fn libc_ty_layout(&self, name: &str) -> InterpResult<'tcx, TyAndLayout<'tcx>> {
120 let this = self.eval_context_ref();
121 let ty = this.resolve_path(&["libc", name]).ty(*this.tcx, ty::ParamEnv::reveal_all());
125 /// Helper function to get the `TyAndLayout` of a `windows` type
126 fn windows_ty_layout(&self, name: &str) -> InterpResult<'tcx, TyAndLayout<'tcx>> {
127 let this = self.eval_context_ref();
129 .resolve_path(&["std", "sys", "windows", "c", name])
130 .ty(*this.tcx, ty::ParamEnv::reveal_all());
134 /// Project to the given *named* field of the mplace (which must be a struct or union type).
135 fn mplace_field_named(
137 mplace: &MPlaceTy<'tcx, Provenance>,
139 ) -> InterpResult<'tcx, MPlaceTy<'tcx, Provenance>> {
140 let this = self.eval_context_ref();
141 let adt = mplace.layout.ty.ty_adt_def().unwrap();
142 for (idx, field) in adt.non_enum_variant().fields.iter().enumerate() {
143 if field.name.as_str() == name {
144 return this.mplace_field(mplace, idx);
147 bug!("No field named {} in type {}", name, mplace.layout.ty);
150 /// Write an int of the appropriate size to `dest`. The target type may be signed or unsigned,
151 /// we try to do the right thing anyway. `i128` can fit all integer types except for `u128` so
152 /// this method is fine for almost all integer types.
156 dest: &PlaceTy<'tcx, Provenance>,
157 ) -> InterpResult<'tcx> {
158 assert!(dest.layout.abi.is_scalar(), "write_int on non-scalar type {}", dest.layout.ty);
159 let val = if dest.layout.abi.is_signed() {
160 Scalar::from_int(i, dest.layout.size)
162 Scalar::from_uint(u64::try_from(i.into()).unwrap(), dest.layout.size)
164 self.eval_context_mut().write_scalar(val, dest)
167 /// Write the first N fields of the given place.
171 dest: &MPlaceTy<'tcx, Provenance>,
172 ) -> InterpResult<'tcx> {
173 let this = self.eval_context_mut();
174 for (idx, &val) in values.iter().enumerate() {
175 let field = this.mplace_field(dest, idx)?;
176 this.write_int(val, &field.into())?;
181 /// Write the given fields of the given place.
182 fn write_int_fields_named(
184 values: &[(&str, i128)],
185 dest: &MPlaceTy<'tcx, Provenance>,
186 ) -> InterpResult<'tcx> {
187 let this = self.eval_context_mut();
188 for &(name, val) in values.iter() {
189 let field = this.mplace_field_named(dest, name)?;
190 this.write_int(val, &field.into())?;
195 /// Write a 0 of the appropriate size to `dest`.
196 fn write_null(&mut self, dest: &PlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> {
197 self.write_int(0, dest)
200 /// Test if this pointer equals 0.
201 fn ptr_is_null(&self, ptr: Pointer<Option<Provenance>>) -> InterpResult<'tcx, bool> {
202 Ok(ptr.addr().bytes() == 0)
205 /// Get the `Place` for a local
206 fn local_place(&mut self, local: mir::Local) -> InterpResult<'tcx, PlaceTy<'tcx, Provenance>> {
207 let this = self.eval_context_mut();
208 let place = mir::Place { local, projection: List::empty() };
209 this.eval_place(place)
212 /// Generate some random bytes, and write them to `dest`.
213 fn gen_random(&mut self, ptr: Pointer<Option<Provenance>>, len: u64) -> InterpResult<'tcx> {
214 // Some programs pass in a null pointer and a length of 0
215 // to their platform's random-generation function (e.g. getrandom())
216 // on Linux. For compatibility with these programs, we don't perform
217 // any additional checks - it's okay if the pointer is invalid,
218 // since we wouldn't actually be writing to it.
222 let this = self.eval_context_mut();
224 let mut data = vec![0; usize::try_from(len).unwrap()];
226 if this.machine.communicate() {
227 // Fill the buffer using the host's rng.
228 getrandom::getrandom(&mut data)
229 .map_err(|err| err_unsup_format!("host getrandom failed: {}", err))?;
231 let rng = this.machine.rng.get_mut();
232 rng.fill_bytes(&mut data);
235 this.write_bytes_ptr(ptr, data.iter().copied())
238 /// Call a function: Push the stack frame and pass the arguments.
239 /// For now, arguments must be scalars (so that the caller does not have to know the layout).
241 /// If you do not provie a return place, a dangling zero-sized place will be created
242 /// for your convenience.
245 f: ty::Instance<'tcx>,
247 args: &[Immediate<Provenance>],
248 dest: Option<&PlaceTy<'tcx, Provenance>>,
249 stack_pop: StackPopCleanup,
250 ) -> InterpResult<'tcx> {
251 let this = self.eval_context_mut();
252 let param_env = ty::ParamEnv::reveal_all(); // in Miri this is always the param_env we use... and this.param_env is private.
253 let callee_abi = f.ty(*this.tcx, param_env).fn_sig(*this.tcx).abi();
254 if this.machine.enforce_abi && callee_abi != caller_abi {
256 "calling a function with ABI {} using caller ABI {}",
263 let mir = this.load_mir(f.def, None)?;
264 let dest = match dest {
265 Some(dest) => dest.clone(),
266 None => MPlaceTy::fake_alloc_zst(this.layout_of(mir.return_ty())?).into(),
268 this.push_stack_frame(f, mir, &dest, stack_pop)?;
270 // Initialize arguments.
271 let mut callee_args = this.frame().body.args_iter();
273 let callee_arg = this.local_place(
276 .ok_or_else(|| err_ub_format!("callee has fewer arguments than expected"))?,
278 this.write_immediate(*arg, &callee_arg)?;
280 if callee_args.next().is_some() {
281 throw_ub_format!("callee has more arguments than expected");
287 /// Visits the memory covered by `place`, sensitive to freezing: the 2nd parameter
288 /// of `action` will be true if this is frozen, false if this is in an `UnsafeCell`.
289 /// The range is relative to `place`.
290 fn visit_freeze_sensitive(
292 place: &MPlaceTy<'tcx, Provenance>,
294 mut action: impl FnMut(AllocRange, bool) -> InterpResult<'tcx>,
295 ) -> InterpResult<'tcx> {
296 let this = self.eval_context_ref();
297 trace!("visit_frozen(place={:?}, size={:?})", *place, size);
300 this.size_and_align_of_mplace(place)?
301 .map(|(size, _)| size)
302 .unwrap_or_else(|| place.layout.size)
304 // Store how far we proceeded into the place so far. Everything to the left of
305 // this offset has already been handled, in the sense that the frozen parts
306 // have had `action` called on them.
307 let start_addr = place.ptr.addr();
308 let mut cur_addr = start_addr;
309 // Called when we detected an `UnsafeCell` at the given offset and size.
310 // Calls `action` and advances `cur_ptr`.
311 let mut unsafe_cell_action = |unsafe_cell_ptr: &Pointer<Option<Provenance>>,
312 unsafe_cell_size: Size| {
313 // We assume that we are given the fields in increasing offset order,
314 // and nothing else changes.
315 let unsafe_cell_addr = unsafe_cell_ptr.addr();
316 assert!(unsafe_cell_addr >= cur_addr);
317 let frozen_size = unsafe_cell_addr - cur_addr;
318 // Everything between the cur_ptr and this `UnsafeCell` is frozen.
319 if frozen_size != Size::ZERO {
320 action(alloc_range(cur_addr - start_addr, frozen_size), /*frozen*/ true)?;
322 cur_addr += frozen_size;
323 // This `UnsafeCell` is NOT frozen.
324 if unsafe_cell_size != Size::ZERO {
326 alloc_range(cur_addr - start_addr, unsafe_cell_size),
330 cur_addr += unsafe_cell_size;
336 let mut visitor = UnsafeCellVisitor {
338 unsafe_cell_action: |place| {
339 trace!("unsafe_cell_action on {:?}", place.ptr);
340 // We need a size to go on.
341 let unsafe_cell_size = this
342 .size_and_align_of_mplace(place)?
343 .map(|(size, _)| size)
344 // for extern types, just cover what we can
345 .unwrap_or_else(|| place.layout.size);
346 // Now handle this `UnsafeCell`, unless it is empty.
347 if unsafe_cell_size != Size::ZERO {
348 unsafe_cell_action(&place.ptr, unsafe_cell_size)
354 visitor.visit_value(place)?;
356 // The part between the end_ptr and the end of the place is also frozen.
357 // So pretend there is a 0-sized `UnsafeCell` at the end.
358 unsafe_cell_action(&place.ptr.offset(size, this)?, Size::ZERO)?;
362 /// Visiting the memory covered by a `MemPlace`, being aware of
363 /// whether we are inside an `UnsafeCell` or not.
364 struct UnsafeCellVisitor<'ecx, 'mir, 'tcx, F>
366 F: FnMut(&MPlaceTy<'tcx, Provenance>) -> InterpResult<'tcx>,
368 ecx: &'ecx MiriEvalContext<'mir, 'tcx>,
369 unsafe_cell_action: F,
372 impl<'ecx, 'mir, 'tcx: 'mir, F> ValueVisitor<'mir, 'tcx, Evaluator<'mir, 'tcx>>
373 for UnsafeCellVisitor<'ecx, 'mir, 'tcx, F>
375 F: FnMut(&MPlaceTy<'tcx, Provenance>) -> InterpResult<'tcx>,
377 type V = MPlaceTy<'tcx, Provenance>;
380 fn ecx(&self) -> &MiriEvalContext<'mir, 'tcx> {
384 // Hook to detect `UnsafeCell`.
385 fn visit_value(&mut self, v: &MPlaceTy<'tcx, Provenance>) -> InterpResult<'tcx> {
386 trace!("UnsafeCellVisitor: {:?} {:?}", *v, v.layout.ty);
387 let is_unsafe_cell = match v.layout.ty.kind() {
389 Some(adt.did()) == self.ecx.tcx.lang_items().unsafe_cell_type(),
393 // We do not have to recurse further, this is an `UnsafeCell`.
394 (self.unsafe_cell_action)(v)
395 } else if self.ecx.type_is_freeze(v.layout.ty) {
396 // This is `Freeze`, there cannot be an `UnsafeCell`
398 } else if matches!(v.layout.fields, FieldsShape::Union(..)) {
399 // A (non-frozen) union. We fall back to whatever the type says.
400 (self.unsafe_cell_action)(v)
402 // We want to not actually read from memory for this visit. So, before
403 // walking this value, we have to make sure it is not a
404 // `Variants::Multiple`.
405 match v.layout.variants {
406 Variants::Multiple { .. } => {
407 // A multi-variant enum, or generator, or so.
408 // Treat this like a union: without reading from memory,
409 // we cannot determine the variant we are in. Reading from
410 // memory would be subject to Stacked Borrows rules, leading
411 // to all sorts of "funny" recursion.
412 // We only end up here if the type is *not* freeze, so we just call the
413 // `UnsafeCell` action.
414 (self.unsafe_cell_action)(v)
416 Variants::Single { .. } => {
417 // Proceed further, try to find where exactly that `UnsafeCell`
425 // Make sure we visit aggregrates in increasing offset order.
428 place: &MPlaceTy<'tcx, Provenance>,
429 fields: impl Iterator<Item = InterpResult<'tcx, MPlaceTy<'tcx, Provenance>>>,
430 ) -> InterpResult<'tcx> {
431 match place.layout.fields {
432 FieldsShape::Array { .. } => {
433 // For the array layout, we know the iterator will yield sorted elements so
434 // we can avoid the allocation.
435 self.walk_aggregate(place, fields)
437 FieldsShape::Arbitrary { .. } => {
438 // Gather the subplaces and sort them before visiting.
439 let mut places = fields
440 .collect::<InterpResult<'tcx, Vec<MPlaceTy<'tcx, Provenance>>>>()?;
441 // we just compare offsets, the abs. value never matters
442 places.sort_by_key(|place| place.ptr.addr());
443 self.walk_aggregate(place, places.into_iter().map(Ok))
445 FieldsShape::Union { .. } | FieldsShape::Primitive => {
447 bug!("unions/primitives are not aggregates we should ever visit")
454 _v: &MPlaceTy<'tcx, Provenance>,
455 _fields: NonZeroUsize,
456 ) -> InterpResult<'tcx> {
457 bug!("we should have already handled unions in `visit_value`")
462 /// Helper function used inside the shims of foreign functions to check that isolation is
463 /// disabled. It returns an error using the `name` of the foreign function if this is not the
465 fn check_no_isolation(&self, name: &str) -> InterpResult<'tcx> {
466 if !self.eval_context_ref().machine.communicate() {
467 self.reject_in_isolation(name, RejectOpWith::Abort)?;
472 /// Helper function used inside the shims of foreign functions which reject the op
473 /// when isolation is enabled. It is used to print a warning/backtrace about the rejection.
474 fn reject_in_isolation(&self, op_name: &str, reject_with: RejectOpWith) -> InterpResult<'tcx> {
475 let this = self.eval_context_ref();
477 RejectOpWith::Abort => isolation_abort_error(op_name),
478 RejectOpWith::WarningWithoutBacktrace => {
481 .warn(&format!("{} was made to return an error due to isolation", op_name));
484 RejectOpWith::Warning => {
485 register_diagnostic(NonHaltingDiagnostic::RejectedIsolatedOp(op_name.to_string()));
488 RejectOpWith::NoWarning => Ok(()), // no warning
492 /// Helper function used inside the shims of foreign functions to assert that the target OS
493 /// is `target_os`. It panics showing a message with the `name` of the foreign function
494 /// if this is not the case.
495 fn assert_target_os(&self, target_os: &str, name: &str) {
497 self.eval_context_ref().tcx.sess.target.os,
499 "`{}` is only available on the `{}` target OS",
505 /// Helper function used inside the shims of foreign functions to assert that the target OS
506 /// is part of the UNIX family. It panics showing a message with the `name` of the foreign function
507 /// if this is not the case.
508 fn assert_target_os_is_unix(&self, name: &str) {
510 target_os_is_unix(self.eval_context_ref().tcx.sess.target.os.as_ref()),
511 "`{}` is only available for supported UNIX family targets",
516 /// Get last error variable as a place, lazily allocating thread-local storage for it if
518 fn last_error_place(&mut self) -> InterpResult<'tcx, MPlaceTy<'tcx, Provenance>> {
519 let this = self.eval_context_mut();
520 if let Some(errno_place) = this.active_thread_ref().last_error {
523 // Allocate new place, set initial value to 0.
524 let errno_layout = this.machine.layouts.u32;
525 let errno_place = this.allocate(errno_layout, MiriMemoryKind::Machine.into())?;
526 this.write_scalar(Scalar::from_u32(0), &errno_place.into())?;
527 this.active_thread_mut().last_error = Some(errno_place);
532 /// Sets the last error variable.
533 fn set_last_error(&mut self, scalar: Scalar<Provenance>) -> InterpResult<'tcx> {
534 let this = self.eval_context_mut();
535 let errno_place = this.last_error_place()?;
536 this.write_scalar(scalar, &errno_place.into())
539 /// Gets the last error variable.
540 fn get_last_error(&mut self) -> InterpResult<'tcx, Scalar<Provenance>> {
541 let this = self.eval_context_mut();
542 let errno_place = this.last_error_place()?;
543 this.read_scalar(&errno_place.into())?.check_init()
546 /// This function tries to produce the most similar OS error from the `std::io::ErrorKind`
547 /// as a platform-specific errnum.
548 fn io_error_to_errnum(
550 err_kind: std::io::ErrorKind,
551 ) -> InterpResult<'tcx, Scalar<Provenance>> {
552 let this = self.eval_context_ref();
553 let target = &this.tcx.sess.target;
554 if target.families.iter().any(|f| f == "unix") {
555 for &(kind, name) in UNIX_IO_ERROR_TABLE {
556 if err_kind == kind {
557 return this.eval_libc(name);
560 throw_unsup_format!("io error {:?} cannot be translated into a raw os error", err_kind)
561 } else if target.families.iter().any(|f| f == "windows") {
562 // FIXME: we have to finish implementing the Windows equivalent of this.
563 use std::io::ErrorKind::*;
567 NotFound => "ERROR_FILE_NOT_FOUND",
568 PermissionDenied => "ERROR_ACCESS_DENIED",
571 "io error {:?} cannot be translated into a raw os error",
578 "converting io::Error into errnum is unsupported for OS {}",
584 /// The inverse of `io_error_to_errnum`.
585 fn errnum_to_io_error(
587 errnum: Scalar<Provenance>,
588 ) -> InterpResult<'tcx, std::io::ErrorKind> {
589 let this = self.eval_context_ref();
590 let target = &this.tcx.sess.target;
591 if target.families.iter().any(|f| f == "unix") {
592 let errnum = errnum.to_i32()?;
593 for &(kind, name) in UNIX_IO_ERROR_TABLE {
594 if errnum == this.eval_libc_i32(name)? {
598 throw_unsup_format!("raw errnum {:?} cannot be translated into io::Error", errnum)
601 "converting errnum into io::Error is unsupported for OS {}",
607 /// Sets the last OS error using a `std::io::ErrorKind`.
608 fn set_last_error_from_io_error(&mut self, err_kind: std::io::ErrorKind) -> InterpResult<'tcx> {
609 self.set_last_error(self.io_error_to_errnum(err_kind)?)
612 /// Helper function that consumes an `std::io::Result<T>` and returns an
613 /// `InterpResult<'tcx,T>::Ok` instead. In case the result is an error, this function returns
614 /// `Ok(-1)` and sets the last OS error accordingly.
616 /// This function uses `T: From<i32>` instead of `i32` directly because some IO related
617 /// functions return different integer types (like `read`, that returns an `i64`).
618 fn try_unwrap_io_result<T: From<i32>>(
620 result: std::io::Result<T>,
621 ) -> InterpResult<'tcx, T> {
625 self.eval_context_mut().set_last_error_from_io_error(e.kind())?;
631 /// Calculates the MPlaceTy given the offset and layout of an access on an operand
632 fn deref_operand_and_offset(
634 op: &OpTy<'tcx, Provenance>,
636 layout: TyAndLayout<'tcx>,
637 ) -> InterpResult<'tcx, MPlaceTy<'tcx, Provenance>> {
638 let this = self.eval_context_ref();
639 let op_place = this.deref_operand(op)?;
640 let offset = Size::from_bytes(offset);
642 // Ensure that the access is within bounds.
643 assert!(op_place.layout.size >= offset + layout.size);
644 let value_place = op_place.offset(offset, layout, this)?;
648 fn read_scalar_at_offset(
650 op: &OpTy<'tcx, Provenance>,
652 layout: TyAndLayout<'tcx>,
653 ) -> InterpResult<'tcx, ScalarMaybeUninit<Provenance>> {
654 let this = self.eval_context_ref();
655 let value_place = this.deref_operand_and_offset(op, offset, layout)?;
656 this.read_scalar(&value_place.into())
659 fn write_scalar_at_offset(
661 op: &OpTy<'tcx, Provenance>,
663 value: impl Into<ScalarMaybeUninit<Provenance>>,
664 layout: TyAndLayout<'tcx>,
665 ) -> InterpResult<'tcx, ()> {
666 let this = self.eval_context_mut();
667 let value_place = this.deref_operand_and_offset(op, offset, layout)?;
668 this.write_scalar(value, &value_place.into())
671 /// Parse a `timespec` struct and return it as a `std::time::Duration`. It returns `None`
672 /// if the value in the `timespec` struct is invalid. Some libc functions will return
673 /// `EINVAL` in this case.
676 tp: &MPlaceTy<'tcx, Provenance>,
677 ) -> InterpResult<'tcx, Option<Duration>> {
678 let this = self.eval_context_mut();
679 let seconds_place = this.mplace_field(tp, 0)?;
680 let seconds_scalar = this.read_scalar(&seconds_place.into())?;
681 let seconds = seconds_scalar.to_machine_isize(this)?;
682 let nanoseconds_place = this.mplace_field(tp, 1)?;
683 let nanoseconds_scalar = this.read_scalar(&nanoseconds_place.into())?;
684 let nanoseconds = nanoseconds_scalar.to_machine_isize(this)?;
687 // tv_sec must be non-negative.
688 let seconds: u64 = seconds.try_into().ok()?;
689 // tv_nsec must be non-negative.
690 let nanoseconds: u32 = nanoseconds.try_into().ok()?;
691 if nanoseconds >= 1_000_000_000 {
692 // tv_nsec must not be greater than 999,999,999.
695 Duration::new(seconds, nanoseconds)
699 fn read_c_str<'a>(&'a self, ptr: Pointer<Option<Provenance>>) -> InterpResult<'tcx, &'a [u8]>
704 let this = self.eval_context_ref();
705 let size1 = Size::from_bytes(1);
707 // Step 1: determine the length.
708 let mut len = Size::ZERO;
710 // FIXME: We are re-getting the allocation each time around the loop.
711 // Would be nice if we could somehow "extend" an existing AllocRange.
712 let alloc = this.get_ptr_alloc(ptr.offset(len, this)?, size1, Align::ONE)?.unwrap(); // not a ZST, so we will get a result
713 let byte = alloc.read_integer(alloc_range(Size::ZERO, size1))?.to_u8()?;
721 // Step 2: get the bytes.
722 this.read_bytes_ptr(ptr, len)
725 fn read_wide_str(&self, mut ptr: Pointer<Option<Provenance>>) -> InterpResult<'tcx, Vec<u16>> {
726 let this = self.eval_context_ref();
727 let size2 = Size::from_bytes(2);
728 let align2 = Align::from_bytes(2).unwrap();
730 let mut wchars = Vec::new();
732 // FIXME: We are re-getting the allocation each time around the loop.
733 // Would be nice if we could somehow "extend" an existing AllocRange.
734 let alloc = this.get_ptr_alloc(ptr, size2, align2)?.unwrap(); // not a ZST, so we will get a result
735 let wchar = alloc.read_integer(alloc_range(Size::ZERO, size2))?.to_u16()?;
740 ptr = ptr.offset(size2, this)?;
747 /// Check that the ABI is what we expect.
748 fn check_abi<'a>(&self, abi: Abi, exp_abi: Abi) -> InterpResult<'a, ()> {
749 if self.eval_context_ref().machine.enforce_abi && abi != exp_abi {
751 "calling a function with ABI {} using caller ABI {}",
759 fn frame_in_std(&self) -> bool {
760 let this = self.eval_context_ref();
761 let Some(start_fn) = this.tcx.lang_items().start_fn() else {
765 let frame = this.frame();
766 // Make an attempt to get at the instance of the function this is inlined from.
767 let instance: Option<_> = try {
768 let scope = frame.current_source_info()?.scope;
769 let inlined_parent = frame.body.source_scopes[scope].inlined_parent_scope?;
770 let source = &frame.body.source_scopes[inlined_parent];
771 source.inlined.expect("inlined_parent_scope points to scope without inline info").0
773 // Fall back to the instance of the function itself.
774 let instance = instance.unwrap_or(frame.instance);
775 // Now check if this is in the same crate as start_fn.
776 this.tcx.def_path(instance.def_id()).krate == this.tcx.def_path(start_fn).krate
779 /// Handler that should be called when unsupported functionality is encountered.
780 /// This function will either panic within the context of the emulated application
781 /// or return an error in the Miri process context
783 /// Return value of `Ok(bool)` indicates whether execution should continue.
784 fn handle_unsupported<S: AsRef<str>>(&mut self, error_msg: S) -> InterpResult<'tcx, ()> {
785 let this = self.eval_context_mut();
786 if this.machine.panic_on_unsupported {
787 // message is slightly different here to make automated analysis easier
788 let error_msg = format!("unsupported Miri functionality: {}", error_msg.as_ref());
789 this.start_panic(error_msg.as_ref(), StackPopUnwind::Skip)?;
792 throw_unsup_format!("{}", error_msg.as_ref());
796 fn check_abi_and_shim_symbol_clash(
801 ) -> InterpResult<'tcx, ()> {
802 self.check_abi(abi, exp_abi)?;
803 if let Some((body, _)) = self.eval_context_mut().lookup_exported_symbol(link_name)? {
804 throw_machine_stop!(TerminationInfo::SymbolShimClashing {
806 span: body.span.data(),
812 fn check_shim<'a, const N: usize>(
817 args: &'a [OpTy<'tcx, Provenance>],
818 ) -> InterpResult<'tcx, &'a [OpTy<'tcx, Provenance>; N]>
820 &'a [OpTy<'tcx, Provenance>; N]: TryFrom<&'a [OpTy<'tcx, Provenance>]>,
822 self.check_abi_and_shim_symbol_clash(abi, exp_abi, link_name)?;
823 check_arg_count(args)
826 /// Mark a machine allocation that was just created as immutable.
827 fn mark_immutable(&mut self, mplace: &MemPlace<Provenance>) {
828 let this = self.eval_context_mut();
829 // This got just allocated, so there definitely is a pointer here.
830 let provenance = mplace.ptr.into_pointer_or_addr().unwrap().provenance;
831 this.alloc_mark_immutable(provenance.get_alloc_id().unwrap()).unwrap();
834 fn item_link_name(&self, def_id: DefId) -> Symbol {
835 let tcx = self.eval_context_ref().tcx;
836 match tcx.get_attrs(def_id, sym::link_name).filter_map(|a| a.value_str()).next() {
838 None => tcx.item_name(def_id),
843 impl<'mir, 'tcx> Evaluator<'mir, 'tcx> {
844 pub fn current_span(&self) -> CurrentSpan<'_, 'mir, 'tcx> {
845 CurrentSpan { span: None, machine: self }
849 /// A `CurrentSpan` should be created infrequently (ideally once) per interpreter step. It does
850 /// nothing on creation, but when `CurrentSpan::get` is called, searches the current stack for the
851 /// topmost frame which corresponds to a local crate, and returns the current span in that frame.
852 /// The result of that search is cached so that later calls are approximately free.
854 pub struct CurrentSpan<'a, 'mir, 'tcx> {
856 machine: &'a Evaluator<'mir, 'tcx>,
859 impl<'a, 'mir, 'tcx> CurrentSpan<'a, 'mir, 'tcx> {
860 pub fn get(&mut self) -> Span {
861 *self.span.get_or_insert_with(|| Self::current_span(self.machine))
865 fn current_span(machine: &Evaluator<'_, '_>) -> Span {
868 .active_thread_stack()
872 let def_id = frame.instance.def_id();
873 def_id.is_local() || machine.local_crates.contains(&def_id.krate)
875 .map(|frame| frame.current_span())
876 .unwrap_or(rustc_span::DUMMY_SP)
880 /// Check that the number of args is what we expect.
881 pub fn check_arg_count<'a, 'tcx, const N: usize>(
882 args: &'a [OpTy<'tcx, Provenance>],
883 ) -> InterpResult<'tcx, &'a [OpTy<'tcx, Provenance>; N]>
885 &'a [OpTy<'tcx, Provenance>; N]: TryFrom<&'a [OpTy<'tcx, Provenance>]>,
887 if let Ok(ops) = args.try_into() {
890 throw_ub_format!("incorrect number of arguments: got {}, expected {}", args.len(), N)
893 pub fn isolation_abort_error<'tcx>(name: &str) -> InterpResult<'tcx> {
894 throw_machine_stop!(TerminationInfo::UnsupportedInIsolation(format!(
895 "{} not available when isolation is enabled",
900 /// Retrieve the list of local crates that should have been passed by cargo-miri in
901 /// MIRI_LOCAL_CRATES and turn them into `CrateNum`s.
902 pub fn get_local_crates(tcx: TyCtxt<'_>) -> Vec<CrateNum> {
903 // Convert the local crate names from the passed-in config into CrateNums so that they can
904 // be looked up quickly during execution
905 let local_crate_names = std::env::var("MIRI_LOCAL_CRATES")
906 .map(|crates| crates.split(',').map(|krate| krate.to_string()).collect::<Vec<_>>())
907 .unwrap_or_default();
908 let mut local_crates = Vec::new();
909 for &crate_num in tcx.crates(()) {
910 let name = tcx.crate_name(crate_num);
911 let name = name.as_str();
912 if local_crate_names.iter().any(|local_name| local_name == name) {
913 local_crates.push(crate_num);
919 /// Helper function used inside the shims of foreign functions to check that
920 /// `target_os` is a supported UNIX OS.
921 pub fn target_os_is_unix(target_os: &str) -> bool {
922 matches!(target_os, "linux" | "macos" | "freebsd")