4 use std::num::NonZeroUsize;
6 use std::time::Duration;
10 use rustc_hir::def_id::{DefId, CRATE_DEF_INDEX};
11 use rustc_middle::mir;
12 use rustc_middle::ty::{
14 layout::{LayoutOf, TyAndLayout},
17 use rustc_span::{def_id::CrateNum, sym, Symbol};
18 use rustc_target::abi::{Align, FieldsShape, Size, Variants};
19 use rustc_target::spec::abi::Abi;
25 impl<'mir, 'tcx: 'mir> EvalContextExt<'mir, 'tcx> for crate::MiriEvalContext<'mir, 'tcx> {}
27 const UNIX_IO_ERROR_TABLE: &[(std::io::ErrorKind, &str)] = {
28 use std::io::ErrorKind::*;
30 (ConnectionRefused, "ECONNREFUSED"),
31 (ConnectionReset, "ECONNRESET"),
32 (PermissionDenied, "EPERM"),
33 (BrokenPipe, "EPIPE"),
34 (NotConnected, "ENOTCONN"),
35 (ConnectionAborted, "ECONNABORTED"),
36 (AddrNotAvailable, "EADDRNOTAVAIL"),
37 (AddrInUse, "EADDRINUSE"),
39 (Interrupted, "EINTR"),
40 (InvalidInput, "EINVAL"),
41 (TimedOut, "ETIMEDOUT"),
42 (AlreadyExists, "EEXIST"),
43 (WouldBlock, "EWOULDBLOCK"),
44 (DirectoryNotEmpty, "ENOTEMPTY"),
48 /// Gets an instance for a path.
49 fn try_resolve_did<'tcx>(tcx: TyCtxt<'tcx>, path: &[&str]) -> Option<DefId> {
50 tcx.crates(()).iter().find(|&&krate| tcx.crate_name(krate).as_str() == path[0]).and_then(
52 let krate = DefId { krate: *krate, index: CRATE_DEF_INDEX };
53 let mut items = tcx.module_children(krate);
54 let mut path_it = path.iter().skip(1).peekable();
56 while let Some(segment) = path_it.next() {
57 for item in mem::take(&mut items).iter() {
58 if item.ident.name.as_str() == *segment {
59 if path_it.peek().is_none() {
60 return Some(item.res.def_id());
63 items = tcx.module_children(item.res.def_id());
73 pub trait EvalContextExt<'mir, 'tcx: 'mir>: crate::MiriEvalContextExt<'mir, 'tcx> {
74 /// Gets an instance for a path; fails gracefully if the path does not exist.
75 fn try_resolve_path(&self, path: &[&str]) -> Option<ty::Instance<'tcx>> {
76 let did = try_resolve_did(self.eval_context_ref().tcx.tcx, path)?;
77 Some(ty::Instance::mono(self.eval_context_ref().tcx.tcx, did))
80 /// Gets an instance for a path.
81 fn resolve_path(&self, path: &[&str]) -> ty::Instance<'tcx> {
82 self.try_resolve_path(path)
83 .unwrap_or_else(|| panic!("failed to find required Rust item: {:?}", path))
86 /// Evaluates the scalar at the specified path. Returns Some(val)
87 /// if the path could be resolved, and None otherwise
88 fn eval_path_scalar(&self, path: &[&str]) -> InterpResult<'tcx, Scalar<Tag>> {
89 let this = self.eval_context_ref();
90 let instance = this.resolve_path(path);
91 let cid = GlobalId { instance, promoted: None };
92 let const_val = this.eval_to_allocation(cid)?;
93 let const_val = this.read_scalar(&const_val.into())?;
94 const_val.check_init()
97 /// Helper function to get a `libc` constant as a `Scalar`.
98 fn eval_libc(&self, name: &str) -> InterpResult<'tcx, Scalar<Tag>> {
99 self.eval_path_scalar(&["libc", name])
102 /// Helper function to get a `libc` constant as an `i32`.
103 fn eval_libc_i32(&self, name: &str) -> InterpResult<'tcx, i32> {
104 // TODO: Cache the result.
105 self.eval_libc(name)?.to_i32()
108 /// Helper function to get a `windows` constant as a `Scalar`.
109 fn eval_windows(&self, module: &str, name: &str) -> InterpResult<'tcx, Scalar<Tag>> {
110 self.eval_context_ref().eval_path_scalar(&["std", "sys", "windows", module, name])
113 /// Helper function to get a `windows` constant as a `u64`.
114 fn eval_windows_u64(&self, module: &str, name: &str) -> InterpResult<'tcx, u64> {
115 // TODO: Cache the result.
116 self.eval_windows(module, name)?.to_u64()
119 /// Helper function to get the `TyAndLayout` of a `libc` type
120 fn libc_ty_layout(&self, name: &str) -> InterpResult<'tcx, TyAndLayout<'tcx>> {
121 let this = self.eval_context_ref();
122 let ty = this.resolve_path(&["libc", name]).ty(*this.tcx, ty::ParamEnv::reveal_all());
126 /// Helper function to get the `TyAndLayout` of a `windows` type
127 fn windows_ty_layout(&self, name: &str) -> InterpResult<'tcx, TyAndLayout<'tcx>> {
128 let this = self.eval_context_ref();
130 .resolve_path(&["std", "sys", "windows", "c", name])
131 .ty(*this.tcx, ty::ParamEnv::reveal_all());
135 /// Project to the given *named* field of the mplace (which must be a struct or union type).
136 fn mplace_field_named(
138 mplace: &MPlaceTy<'tcx, Tag>,
140 ) -> InterpResult<'tcx, MPlaceTy<'tcx, Tag>> {
141 let this = self.eval_context_ref();
142 let adt = mplace.layout.ty.ty_adt_def().unwrap();
143 for (idx, field) in adt.non_enum_variant().fields.iter().enumerate() {
144 if field.name.as_str() == name {
145 return this.mplace_field(mplace, idx);
148 bug!("No field named {} in type {}", name, mplace.layout.ty);
151 /// Write an int of the appropriate size to `dest`. The target type may be signed or unsigned,
152 /// we try to do the right thing anyway. `i128` can fit all integer types except for `u128` so
153 /// this method is fine for almost all integer types.
154 fn write_int(&mut self, i: impl Into<i128>, dest: &PlaceTy<'tcx, Tag>) -> InterpResult<'tcx> {
155 assert!(dest.layout.abi.is_scalar(), "write_int on non-scalar type {}", dest.layout.ty);
156 let val = if dest.layout.abi.is_signed() {
157 Scalar::from_int(i, dest.layout.size)
159 Scalar::from_uint(u64::try_from(i.into()).unwrap(), dest.layout.size)
161 self.eval_context_mut().write_scalar(val, dest)
164 /// Write the first N fields of the given place.
168 dest: &MPlaceTy<'tcx, Tag>,
169 ) -> InterpResult<'tcx> {
170 let this = self.eval_context_mut();
171 for (idx, &val) in values.iter().enumerate() {
172 let field = this.mplace_field(dest, idx)?;
173 this.write_int(val, &field.into())?;
178 /// Write the given fields of the given place.
179 fn write_int_fields_named(
181 values: &[(&str, i128)],
182 dest: &MPlaceTy<'tcx, Tag>,
183 ) -> InterpResult<'tcx> {
184 let this = self.eval_context_mut();
185 for &(name, val) in values.iter() {
186 let field = this.mplace_field_named(dest, name)?;
187 this.write_int(val, &field.into())?;
192 /// Write a 0 of the appropriate size to `dest`.
193 fn write_null(&mut self, dest: &PlaceTy<'tcx, Tag>) -> InterpResult<'tcx> {
194 self.write_int(0, dest)
197 /// Test if this pointer equals 0.
198 fn ptr_is_null(&self, ptr: Pointer<Option<Tag>>) -> InterpResult<'tcx, bool> {
199 let this = self.eval_context_ref();
200 let null = Scalar::null_ptr(this);
201 this.ptr_eq(Scalar::from_maybe_pointer(ptr, this), null)
204 /// Get the `Place` for a local
205 fn local_place(&mut self, local: mir::Local) -> InterpResult<'tcx, PlaceTy<'tcx, Tag>> {
206 let this = self.eval_context_mut();
207 let place = mir::Place { local, projection: List::empty() };
208 this.eval_place(place)
211 /// Generate some random bytes, and write them to `dest`.
212 fn gen_random(&mut self, ptr: Pointer<Option<Tag>>, len: u64) -> InterpResult<'tcx> {
213 // Some programs pass in a null pointer and a length of 0
214 // to their platform's random-generation function (e.g. getrandom())
215 // on Linux. For compatibility with these programs, we don't perform
216 // any additional checks - it's okay if the pointer is invalid,
217 // since we wouldn't actually be writing to it.
221 let this = self.eval_context_mut();
223 let mut data = vec![0; usize::try_from(len).unwrap()];
225 if this.machine.communicate() {
226 // Fill the buffer using the host's rng.
227 getrandom::getrandom(&mut data)
228 .map_err(|err| err_unsup_format!("host getrandom failed: {}", err))?;
230 let rng = this.machine.rng.get_mut();
231 rng.fill_bytes(&mut data);
234 this.write_bytes_ptr(ptr, data.iter().copied())
237 /// Call a function: Push the stack frame and pass the arguments.
238 /// For now, arguments must be scalars (so that the caller does not have to know the layout).
241 f: ty::Instance<'tcx>,
243 args: &[Immediate<Tag>],
244 dest: Option<&PlaceTy<'tcx, Tag>>,
245 stack_pop: StackPopCleanup,
246 ) -> InterpResult<'tcx> {
247 let this = self.eval_context_mut();
248 let param_env = ty::ParamEnv::reveal_all(); // in Miri this is always the param_env we use... and this.param_env is private.
249 let callee_abi = f.ty(*this.tcx, param_env).fn_sig(*this.tcx).abi();
250 if this.machine.enforce_abi && callee_abi != caller_abi {
252 "calling a function with ABI {} using caller ABI {}",
259 let mir = &*this.load_mir(f.def, None)?;
260 this.push_stack_frame(f, mir, dest, stack_pop)?;
262 // Initialize arguments.
263 let mut callee_args = this.frame().body.args_iter();
265 let callee_arg = this.local_place(
268 .ok_or_else(|| err_ub_format!("callee has fewer arguments than expected"))?,
270 this.write_immediate(*arg, &callee_arg)?;
272 if callee_args.next().is_some() {
273 throw_ub_format!("callee has more arguments than expected");
279 /// Visits the memory covered by `place`, sensitive to freezing: the 2nd parameter
280 /// of `action` will be true if this is frozen, false if this is in an `UnsafeCell`.
281 /// The range is relative to `place`.
282 fn visit_freeze_sensitive(
284 place: &MPlaceTy<'tcx, Tag>,
286 mut action: impl FnMut(AllocRange, bool) -> InterpResult<'tcx>,
287 ) -> InterpResult<'tcx> {
288 let this = self.eval_context_ref();
289 trace!("visit_frozen(place={:?}, size={:?})", *place, size);
292 this.size_and_align_of_mplace(place)?
293 .map(|(size, _)| size)
294 .unwrap_or_else(|| place.layout.size)
296 // Store how far we proceeded into the place so far. Everything to the left of
297 // this offset has already been handled, in the sense that the frozen parts
298 // have had `action` called on them.
299 let start_addr = place.ptr.addr();
300 let mut cur_addr = start_addr;
301 // Called when we detected an `UnsafeCell` at the given offset and size.
302 // Calls `action` and advances `cur_ptr`.
303 let mut unsafe_cell_action = |unsafe_cell_ptr: &Pointer<Option<Tag>>,
304 unsafe_cell_size: Size| {
305 // We assume that we are given the fields in increasing offset order,
306 // and nothing else changes.
307 let unsafe_cell_addr = unsafe_cell_ptr.addr();
308 assert!(unsafe_cell_addr >= cur_addr);
309 let frozen_size = unsafe_cell_addr - cur_addr;
310 // Everything between the cur_ptr and this `UnsafeCell` is frozen.
311 if frozen_size != Size::ZERO {
312 action(alloc_range(cur_addr - start_addr, frozen_size), /*frozen*/ true)?;
314 cur_addr += frozen_size;
315 // This `UnsafeCell` is NOT frozen.
316 if unsafe_cell_size != Size::ZERO {
318 alloc_range(cur_addr - start_addr, unsafe_cell_size),
322 cur_addr += unsafe_cell_size;
328 let mut visitor = UnsafeCellVisitor {
330 unsafe_cell_action: |place| {
331 trace!("unsafe_cell_action on {:?}", place.ptr);
332 // We need a size to go on.
333 let unsafe_cell_size = this
334 .size_and_align_of_mplace(place)?
335 .map(|(size, _)| size)
336 // for extern types, just cover what we can
337 .unwrap_or_else(|| place.layout.size);
338 // Now handle this `UnsafeCell`, unless it is empty.
339 if unsafe_cell_size != Size::ZERO {
340 unsafe_cell_action(&place.ptr, unsafe_cell_size)
346 visitor.visit_value(place)?;
348 // The part between the end_ptr and the end of the place is also frozen.
349 // So pretend there is a 0-sized `UnsafeCell` at the end.
350 unsafe_cell_action(&place.ptr.offset(size, this)?, Size::ZERO)?;
354 /// Visiting the memory covered by a `MemPlace`, being aware of
355 /// whether we are inside an `UnsafeCell` or not.
356 struct UnsafeCellVisitor<'ecx, 'mir, 'tcx, F>
358 F: FnMut(&MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx>,
360 ecx: &'ecx MiriEvalContext<'mir, 'tcx>,
361 unsafe_cell_action: F,
364 impl<'ecx, 'mir, 'tcx: 'mir, F> ValueVisitor<'mir, 'tcx, Evaluator<'mir, 'tcx>>
365 for UnsafeCellVisitor<'ecx, 'mir, 'tcx, F>
367 F: FnMut(&MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx>,
369 type V = MPlaceTy<'tcx, Tag>;
372 fn ecx(&self) -> &MiriEvalContext<'mir, 'tcx> {
376 // Hook to detect `UnsafeCell`.
377 fn visit_value(&mut self, v: &MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx> {
378 trace!("UnsafeCellVisitor: {:?} {:?}", *v, v.layout.ty);
379 let is_unsafe_cell = match v.layout.ty.kind() {
381 Some(adt.did()) == self.ecx.tcx.lang_items().unsafe_cell_type(),
385 // We do not have to recurse further, this is an `UnsafeCell`.
386 (self.unsafe_cell_action)(v)
387 } else if self.ecx.type_is_freeze(v.layout.ty) {
388 // This is `Freeze`, there cannot be an `UnsafeCell`
390 } else if matches!(v.layout.fields, FieldsShape::Union(..)) {
391 // A (non-frozen) union. We fall back to whatever the type says.
392 (self.unsafe_cell_action)(v)
394 // We want to not actually read from memory for this visit. So, before
395 // walking this value, we have to make sure it is not a
396 // `Variants::Multiple`.
397 match v.layout.variants {
398 Variants::Multiple { .. } => {
399 // A multi-variant enum, or generator, or so.
400 // Treat this like a union: without reading from memory,
401 // we cannot determine the variant we are in. Reading from
402 // memory would be subject to Stacked Borrows rules, leading
403 // to all sorts of "funny" recursion.
404 // We only end up here if the type is *not* freeze, so we just call the
405 // `UnsafeCell` action.
406 (self.unsafe_cell_action)(v)
408 Variants::Single { .. } => {
409 // Proceed further, try to find where exactly that `UnsafeCell`
417 // Make sure we visit aggregrates in increasing offset order.
420 place: &MPlaceTy<'tcx, Tag>,
421 fields: impl Iterator<Item = InterpResult<'tcx, MPlaceTy<'tcx, Tag>>>,
422 ) -> InterpResult<'tcx> {
423 match place.layout.fields {
424 FieldsShape::Array { .. } => {
425 // For the array layout, we know the iterator will yield sorted elements so
426 // we can avoid the allocation.
427 self.walk_aggregate(place, fields)
429 FieldsShape::Arbitrary { .. } => {
430 // Gather the subplaces and sort them before visiting.
432 fields.collect::<InterpResult<'tcx, Vec<MPlaceTy<'tcx, Tag>>>>()?;
433 // we just compare offsets, the abs. value never matters
434 places.sort_by_key(|place| place.ptr.addr());
435 self.walk_aggregate(place, places.into_iter().map(Ok))
437 FieldsShape::Union { .. } | FieldsShape::Primitive => {
439 bug!("unions/primitives are not aggregates we should ever visit")
446 _v: &MPlaceTy<'tcx, Tag>,
447 _fields: NonZeroUsize,
448 ) -> InterpResult<'tcx> {
449 bug!("we should have already handled unions in `visit_value`")
454 /// Helper function used inside the shims of foreign functions to check that isolation is
455 /// disabled. It returns an error using the `name` of the foreign function if this is not the
457 fn check_no_isolation(&self, name: &str) -> InterpResult<'tcx> {
458 if !self.eval_context_ref().machine.communicate() {
459 self.reject_in_isolation(name, RejectOpWith::Abort)?;
464 /// Helper function used inside the shims of foreign functions which reject the op
465 /// when isolation is enabled. It is used to print a warning/backtrace about the rejection.
466 fn reject_in_isolation(&self, op_name: &str, reject_with: RejectOpWith) -> InterpResult<'tcx> {
467 let this = self.eval_context_ref();
469 RejectOpWith::Abort => isolation_abort_error(op_name),
470 RejectOpWith::WarningWithoutBacktrace => {
473 .warn(&format!("{} was made to return an error due to isolation", op_name));
476 RejectOpWith::Warning => {
477 register_diagnostic(NonHaltingDiagnostic::RejectedIsolatedOp(op_name.to_string()));
480 RejectOpWith::NoWarning => Ok(()), // no warning
484 /// Helper function used inside the shims of foreign functions to assert that the target OS
485 /// is `target_os`. It panics showing a message with the `name` of the foreign function
486 /// if this is not the case.
487 fn assert_target_os(&self, target_os: &str, name: &str) {
489 self.eval_context_ref().tcx.sess.target.os,
491 "`{}` is only available on the `{}` target OS",
497 /// Get last error variable as a place, lazily allocating thread-local storage for it if
499 fn last_error_place(&mut self) -> InterpResult<'tcx, MPlaceTy<'tcx, Tag>> {
500 let this = self.eval_context_mut();
501 if let Some(errno_place) = this.active_thread_ref().last_error {
504 // Allocate new place, set initial value to 0.
505 let errno_layout = this.machine.layouts.u32;
506 let errno_place = this.allocate(errno_layout, MiriMemoryKind::Machine.into())?;
507 this.write_scalar(Scalar::from_u32(0), &errno_place.into())?;
508 this.active_thread_mut().last_error = Some(errno_place);
513 /// Sets the last error variable.
514 fn set_last_error(&mut self, scalar: Scalar<Tag>) -> InterpResult<'tcx> {
515 let this = self.eval_context_mut();
516 let errno_place = this.last_error_place()?;
517 this.write_scalar(scalar, &errno_place.into())
520 /// Gets the last error variable.
521 fn get_last_error(&mut self) -> InterpResult<'tcx, Scalar<Tag>> {
522 let this = self.eval_context_mut();
523 let errno_place = this.last_error_place()?;
524 this.read_scalar(&errno_place.into())?.check_init()
527 /// This function tries to produce the most similar OS error from the `std::io::ErrorKind`
528 /// as a platform-specific errnum.
529 fn io_error_to_errnum(&self, err_kind: std::io::ErrorKind) -> InterpResult<'tcx, Scalar<Tag>> {
530 let this = self.eval_context_ref();
531 let target = &this.tcx.sess.target;
532 if target.families.iter().any(|f| f == "unix") {
533 for &(kind, name) in UNIX_IO_ERROR_TABLE {
534 if err_kind == kind {
535 return this.eval_libc(name);
538 throw_unsup_format!("io error {:?} cannot be translated into a raw os error", err_kind)
539 } else if target.families.iter().any(|f| f == "windows") {
540 // FIXME: we have to finish implementing the Windows equivalent of this.
541 use std::io::ErrorKind::*;
545 NotFound => "ERROR_FILE_NOT_FOUND",
546 PermissionDenied => "ERROR_ACCESS_DENIED",
549 "io error {:?} cannot be translated into a raw os error",
556 "converting io::Error into errnum is unsupported for OS {}",
562 /// The inverse of `io_error_to_errnum`.
563 fn errnum_to_io_error(&self, errnum: Scalar<Tag>) -> InterpResult<'tcx, std::io::ErrorKind> {
564 let this = self.eval_context_ref();
565 let target = &this.tcx.sess.target;
566 if target.families.iter().any(|f| f == "unix") {
567 let errnum = errnum.to_i32()?;
568 for &(kind, name) in UNIX_IO_ERROR_TABLE {
569 if errnum == this.eval_libc_i32(name)? {
573 throw_unsup_format!("raw errnum {:?} cannot be translated into io::Error", errnum)
576 "converting errnum into io::Error is unsupported for OS {}",
582 /// Sets the last OS error using a `std::io::ErrorKind`.
583 fn set_last_error_from_io_error(&mut self, err_kind: std::io::ErrorKind) -> InterpResult<'tcx> {
584 self.set_last_error(self.io_error_to_errnum(err_kind)?)
587 /// Helper function that consumes an `std::io::Result<T>` and returns an
588 /// `InterpResult<'tcx,T>::Ok` instead. In case the result is an error, this function returns
589 /// `Ok(-1)` and sets the last OS error accordingly.
591 /// This function uses `T: From<i32>` instead of `i32` directly because some IO related
592 /// functions return different integer types (like `read`, that returns an `i64`).
593 fn try_unwrap_io_result<T: From<i32>>(
595 result: std::io::Result<T>,
596 ) -> InterpResult<'tcx, T> {
600 self.eval_context_mut().set_last_error_from_io_error(e.kind())?;
606 /// Calculates the MPlaceTy given the offset and layout of an access on an operand
607 fn deref_operand_and_offset(
609 op: &OpTy<'tcx, Tag>,
611 layout: TyAndLayout<'tcx>,
612 ) -> InterpResult<'tcx, MPlaceTy<'tcx, Tag>> {
613 let this = self.eval_context_ref();
614 let op_place = this.deref_operand(op)?;
615 let offset = Size::from_bytes(offset);
617 // Ensure that the access is within bounds.
618 assert!(op_place.layout.size >= offset + layout.size);
619 let value_place = op_place.offset(offset, MemPlaceMeta::None, layout, this)?;
623 fn read_scalar_at_offset(
625 op: &OpTy<'tcx, Tag>,
627 layout: TyAndLayout<'tcx>,
628 ) -> InterpResult<'tcx, ScalarMaybeUninit<Tag>> {
629 let this = self.eval_context_ref();
630 let value_place = this.deref_operand_and_offset(op, offset, layout)?;
631 this.read_scalar(&value_place.into())
634 fn write_scalar_at_offset(
636 op: &OpTy<'tcx, Tag>,
638 value: impl Into<ScalarMaybeUninit<Tag>>,
639 layout: TyAndLayout<'tcx>,
640 ) -> InterpResult<'tcx, ()> {
641 let this = self.eval_context_mut();
642 let value_place = this.deref_operand_and_offset(op, offset, layout)?;
643 this.write_scalar(value, &value_place.into())
646 /// Parse a `timespec` struct and return it as a `std::time::Duration`. It returns `None`
647 /// if the value in the `timespec` struct is invalid. Some libc functions will return
648 /// `EINVAL` in this case.
649 fn read_timespec(&mut self, tp: &MPlaceTy<'tcx, Tag>) -> InterpResult<'tcx, Option<Duration>> {
650 let this = self.eval_context_mut();
651 let seconds_place = this.mplace_field(tp, 0)?;
652 let seconds_scalar = this.read_scalar(&seconds_place.into())?;
653 let seconds = seconds_scalar.to_machine_isize(this)?;
654 let nanoseconds_place = this.mplace_field(tp, 1)?;
655 let nanoseconds_scalar = this.read_scalar(&nanoseconds_place.into())?;
656 let nanoseconds = nanoseconds_scalar.to_machine_isize(this)?;
659 // tv_sec must be non-negative.
660 let seconds: u64 = seconds.try_into().ok()?;
661 // tv_nsec must be non-negative.
662 let nanoseconds: u32 = nanoseconds.try_into().ok()?;
663 if nanoseconds >= 1_000_000_000 {
664 // tv_nsec must not be greater than 999,999,999.
667 Duration::new(seconds, nanoseconds)
671 fn read_c_str<'a>(&'a self, ptr: Pointer<Option<Tag>>) -> InterpResult<'tcx, &'a [u8]>
676 let this = self.eval_context_ref();
677 let size1 = Size::from_bytes(1);
679 // Step 1: determine the length.
680 let mut len = Size::ZERO;
682 // FIXME: We are re-getting the allocation each time around the loop.
683 // Would be nice if we could somehow "extend" an existing AllocRange.
684 let alloc = this.get_ptr_alloc(ptr.offset(len, this)?, size1, Align::ONE)?.unwrap(); // not a ZST, so we will get a result
685 let byte = alloc.read_scalar(alloc_range(Size::ZERO, size1))?.to_u8()?;
693 // Step 2: get the bytes.
694 this.read_bytes_ptr(ptr, len)
697 fn read_wide_str(&self, mut ptr: Pointer<Option<Tag>>) -> InterpResult<'tcx, Vec<u16>> {
698 let this = self.eval_context_ref();
699 let size2 = Size::from_bytes(2);
700 let align2 = Align::from_bytes(2).unwrap();
702 let mut wchars = Vec::new();
704 // FIXME: We are re-getting the allocation each time around the loop.
705 // Would be nice if we could somehow "extend" an existing AllocRange.
706 let alloc = this.get_ptr_alloc(ptr, size2, align2)?.unwrap(); // not a ZST, so we will get a result
707 let wchar = alloc.read_scalar(alloc_range(Size::ZERO, size2))?.to_u16()?;
712 ptr = ptr.offset(size2, this)?;
719 /// Check that the ABI is what we expect.
720 fn check_abi<'a>(&self, abi: Abi, exp_abi: Abi) -> InterpResult<'a, ()> {
721 if self.eval_context_ref().machine.enforce_abi && abi != exp_abi {
723 "calling a function with ABI {} using caller ABI {}",
731 fn frame_in_std(&self) -> bool {
732 let this = self.eval_context_ref();
733 this.tcx.lang_items().start_fn().map_or(false, |start_fn| {
734 this.tcx.def_path(this.frame().instance.def_id()).krate
735 == this.tcx.def_path(start_fn).krate
739 /// Handler that should be called when unsupported functionality is encountered.
740 /// This function will either panic within the context of the emulated application
741 /// or return an error in the Miri process context
743 /// Return value of `Ok(bool)` indicates whether execution should continue.
744 fn handle_unsupported<S: AsRef<str>>(&mut self, error_msg: S) -> InterpResult<'tcx, ()> {
745 let this = self.eval_context_mut();
746 if this.machine.panic_on_unsupported {
747 // message is slightly different here to make automated analysis easier
748 let error_msg = format!("unsupported Miri functionality: {}", error_msg.as_ref());
749 this.start_panic(error_msg.as_ref(), StackPopUnwind::Skip)?;
752 throw_unsup_format!("{}", error_msg.as_ref());
756 fn check_abi_and_shim_symbol_clash(
761 ) -> InterpResult<'tcx, ()> {
762 self.check_abi(abi, exp_abi)?;
763 if let Some((body, _)) = self.eval_context_mut().lookup_exported_symbol(link_name)? {
764 throw_machine_stop!(TerminationInfo::SymbolShimClashing {
766 span: body.span.data(),
772 fn check_shim<'a, const N: usize>(
777 args: &'a [OpTy<'tcx, Tag>],
778 ) -> InterpResult<'tcx, &'a [OpTy<'tcx, Tag>; N]>
780 &'a [OpTy<'tcx, Tag>; N]: TryFrom<&'a [OpTy<'tcx, Tag>]>,
782 self.check_abi_and_shim_symbol_clash(abi, exp_abi, link_name)?;
783 check_arg_count(args)
786 /// Mark a machine allocation that was just created as immutable.
787 fn mark_immutable(&mut self, mplace: &MemPlace<Tag>) {
788 let this = self.eval_context_mut();
789 // This got just allocated, so there definitely is a pointer here.
790 this.alloc_mark_immutable(mplace.ptr.into_pointer_or_addr().unwrap().provenance.alloc_id)
794 fn item_link_name(&self, def_id: DefId) -> Symbol {
795 let tcx = self.eval_context_ref().tcx;
796 match tcx.get_attrs(def_id, sym::link_name).filter_map(|a| a.value_str()).next() {
798 None => tcx.item_name(def_id),
803 /// Check that the number of args is what we expect.
804 pub fn check_arg_count<'a, 'tcx, const N: usize>(
805 args: &'a [OpTy<'tcx, Tag>],
806 ) -> InterpResult<'tcx, &'a [OpTy<'tcx, Tag>; N]>
808 &'a [OpTy<'tcx, Tag>; N]: TryFrom<&'a [OpTy<'tcx, Tag>]>,
810 if let Ok(ops) = args.try_into() {
813 throw_ub_format!("incorrect number of arguments: got {}, expected {}", args.len(), N)
816 pub fn isolation_abort_error(name: &str) -> InterpResult<'static> {
817 throw_machine_stop!(TerminationInfo::UnsupportedInIsolation(format!(
818 "{} not available when isolation is enabled",
823 /// Retrieve the list of local crates that should have been passed by cargo-miri in
824 /// MIRI_LOCAL_CRATES and turn them into `CrateNum`s.
825 pub fn get_local_crates(tcx: &TyCtxt<'_>) -> Rc<[CrateNum]> {
826 // Convert the local crate names from the passed-in config into CrateNums so that they can
827 // be looked up quickly during execution
828 let local_crate_names = std::env::var("MIRI_LOCAL_CRATES")
829 .map(|crates| crates.split(',').map(|krate| krate.to_string()).collect::<Vec<_>>())
830 .unwrap_or_default();
831 let mut local_crates = Vec::new();
832 for &crate_num in tcx.crates(()) {
833 let name = tcx.crate_name(crate_num);
834 let name = name.as_str();
835 if local_crate_names.iter().any(|local_name| local_name == name) {
836 local_crates.push(crate_num);
839 Rc::from(local_crates.as_slice())
842 /// Formats an AllocRange like [0x1..0x3], for use in diagnostics.
843 pub struct HexRange(pub AllocRange);
845 impl std::fmt::Display for HexRange {
846 fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
847 write!(f, "[{:#x}..{:#x}]", self.0.start.bytes(), self.0.end().bytes())