1 //! Check the validity invariant of a given value, and tell the user
2 //! where in the value it got violated.
3 //! In const context, this goes even further and tries to approximate const safety.
4 //! That's useful because it means other passes (e.g. promotion) can rely on `const`s
7 use std::convert::TryFrom;
9 use std::num::NonZeroUsize;
10 use std::ops::RangeInclusive;
12 use rustc_data_structures::fx::FxHashSet;
15 use rustc_middle::ty::layout::TyAndLayout;
16 use rustc_span::symbol::{sym, Symbol};
17 use rustc_target::abi::{Abi, LayoutOf, Scalar, VariantIdx, Variants};
22 CheckInAllocMsg, GlobalAlloc, InterpCx, InterpResult, MPlaceTy, Machine, MemPlaceMeta, OpTy,
26 macro_rules! throw_validation_failure {
27 ($what:expr, $where:expr $(, $details:expr )?) => {{
28 let mut msg = format!("encountered {}", $what);
30 if !where_.is_empty() {
32 write_path(&mut msg, where_);
34 $( write!(&mut msg, ", but expected {}", $details).unwrap(); )?
35 throw_ub!(ValidationFailure(msg))
39 macro_rules! try_validation {
40 ($e:expr, $what:expr, $where:expr $(, $details:expr )?) => {{
43 // We catch the error and turn it into a validation failure. We are okay with
44 // allocation here as this can only slow down builds that fail anyway.
45 Err(_) => throw_validation_failure!($what, $where $(, $details)?),
50 /// We want to show a nice path to the invalid field for diagnostics,
51 /// but avoid string operations in the happy case where no error happens.
52 /// So we track a `Vec<PathElem>` where `PathElem` contains all the data we
53 /// need to later print something for the user.
54 #[derive(Copy, Clone, Debug)]
58 GeneratorState(VariantIdx),
68 /// State for tracking recursive validation of references
69 pub struct RefTracking<T, PATH = ()> {
70 pub seen: FxHashSet<T>,
71 pub todo: Vec<(T, PATH)>,
74 impl<T: Copy + Eq + Hash + std::fmt::Debug, PATH: Default> RefTracking<T, PATH> {
75 pub fn empty() -> Self {
76 RefTracking { seen: FxHashSet::default(), todo: vec![] }
78 pub fn new(op: T) -> Self {
79 let mut ref_tracking_for_consts =
80 RefTracking { seen: FxHashSet::default(), todo: vec![(op, PATH::default())] };
81 ref_tracking_for_consts.seen.insert(op);
82 ref_tracking_for_consts
85 pub fn track(&mut self, op: T, path: impl FnOnce() -> PATH) {
86 if self.seen.insert(op) {
87 trace!("Recursing below ptr {:#?}", op);
89 // Remember to come back to this later.
90 self.todo.push((op, path));
96 fn write_path(out: &mut String, path: &Vec<PathElem>) {
97 use self::PathElem::*;
99 for elem in path.iter() {
101 Field(name) => write!(out, ".{}", name),
102 EnumTag => write!(out, ".<enum-tag>"),
103 Variant(name) => write!(out, ".<enum-variant({})>", name),
104 GeneratorTag => write!(out, ".<generator-tag>"),
105 GeneratorState(idx) => write!(out, ".<generator-state({})>", idx.index()),
106 CapturedVar(name) => write!(out, ".<captured-var({})>", name),
107 TupleElem(idx) => write!(out, ".{}", idx),
108 ArrayElem(idx) => write!(out, "[{}]", idx),
109 // `.<deref>` does not match Rust syntax, but it is more readable for long paths -- and
110 // some of the other items here also are not Rust syntax. Actually we can't
111 // even use the usual syntax because we are just showing the projections,
113 Deref => write!(out, ".<deref>"),
114 DynDowncast => write!(out, ".<dyn-downcast>"),
120 // Test if a range that wraps at overflow contains `test`
121 fn wrapping_range_contains(r: &RangeInclusive<u128>, test: u128) -> bool {
122 let (lo, hi) = r.clone().into_inner();
125 (..=hi).contains(&test) || (lo..).contains(&test)
132 // Formats such that a sentence like "expected something {}" to mean
133 // "expected something <in the given range>" makes sense.
134 fn wrapping_range_format(r: &RangeInclusive<u128>, max_hi: u128) -> String {
135 let (lo, hi) = r.clone().into_inner();
136 assert!(hi <= max_hi);
138 format!("less or equal to {}, or greater or equal to {}", hi, lo)
140 format!("equal to {}", lo)
142 assert!(hi < max_hi, "should not be printing if the range covers everything");
143 format!("less or equal to {}", hi)
144 } else if hi == max_hi {
145 assert!(lo > 0, "should not be printing if the range covers everything");
146 format!("greater or equal to {}", lo)
148 format!("in the range {:?}", r)
152 struct ValidityVisitor<'rt, 'mir, 'tcx, M: Machine<'mir, 'tcx>> {
153 /// The `path` may be pushed to, but the part that is present when a function
154 /// starts must not be changed! `visit_fields` and `visit_array` rely on
155 /// this stack discipline.
157 ref_tracking_for_consts:
158 Option<&'rt mut RefTracking<MPlaceTy<'tcx, M::PointerTag>, Vec<PathElem>>>,
159 may_ref_to_static: bool,
160 ecx: &'rt InterpCx<'mir, 'tcx, M>,
163 impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValidityVisitor<'rt, 'mir, 'tcx, M> {
164 fn aggregate_field_path_elem(&mut self, layout: TyAndLayout<'tcx>, field: usize) -> PathElem {
165 // First, check if we are projecting to a variant.
166 match layout.variants {
167 Variants::Multiple { discr_index, .. } => {
168 if discr_index == field {
169 return match layout.ty.kind {
170 ty::Adt(def, ..) if def.is_enum() => PathElem::EnumTag,
171 ty::Generator(..) => PathElem::GeneratorTag,
172 _ => bug!("non-variant type {:?}", layout.ty),
176 Variants::Single { .. } => {}
179 // Now we know we are projecting to a field, so figure out which one.
180 match layout.ty.kind {
181 // generators and closures.
182 ty::Closure(def_id, _) | ty::Generator(def_id, _, _) => {
184 if let Some(def_id) = def_id.as_local() {
185 let tables = self.ecx.tcx.typeck_tables_of(def_id);
186 if let Some(upvars) = tables.upvar_list.get(&def_id.to_def_id()) {
187 // Sometimes the index is beyond the number of upvars (seen
189 if let Some((&var_hir_id, _)) = upvars.get_index(field) {
190 let node = self.ecx.tcx.hir().get(var_hir_id);
191 if let hir::Node::Binding(pat) = node {
192 if let hir::PatKind::Binding(_, _, ident, _) = pat.kind {
193 name = Some(ident.name);
200 PathElem::CapturedVar(name.unwrap_or_else(|| {
201 // Fall back to showing the field index.
207 ty::Tuple(_) => PathElem::TupleElem(field),
210 ty::Adt(def, ..) if def.is_enum() => {
211 // we might be projecting *to* a variant, or to a field *in* a variant.
212 match layout.variants {
213 Variants::Single { index } => {
215 PathElem::Field(def.variants[index].fields[field].ident.name)
217 Variants::Multiple { .. } => bug!("we handled variants above"),
222 ty::Adt(def, _) => PathElem::Field(def.non_enum_variant().fields[field].ident.name),
225 ty::Array(..) | ty::Slice(..) => PathElem::ArrayElem(field),
228 ty::Dynamic(..) => PathElem::DynDowncast,
230 // nothing else has an aggregate layout
231 _ => bug!("aggregate_field_path_elem: got non-aggregate type {:?}", layout.ty),
237 new_op: OpTy<'tcx, M::PointerTag>,
239 ) -> InterpResult<'tcx> {
240 // Remember the old state
241 let path_len = self.path.len();
243 self.path.push(elem);
244 self.visit_value(new_op)?;
246 self.path.truncate(path_len);
250 fn check_wide_ptr_meta(
252 meta: MemPlaceMeta<M::PointerTag>,
253 pointee: TyAndLayout<'tcx>,
254 ) -> InterpResult<'tcx> {
255 let tail = self.ecx.tcx.struct_tail_erasing_lifetimes(pointee.ty, self.ecx.param_env);
258 let vtable = meta.unwrap_meta();
260 self.ecx.memory.check_ptr_access(
262 3 * self.ecx.tcx.data_layout.pointer_size, // drop, size, align
263 self.ecx.tcx.data_layout.pointer_align.abi,
265 "dangling or unaligned vtable pointer in wide pointer or too small vtable",
269 self.ecx.read_drop_type_from_vtable(vtable),
270 "invalid drop fn in vtable",
274 self.ecx.read_size_and_align_from_vtable(vtable),
275 "invalid size or align in vtable",
278 // FIXME: More checks for the vtable.
280 ty::Slice(..) | ty::Str => {
281 let _len = try_validation!(
282 meta.unwrap_meta().to_machine_usize(self.ecx),
283 "non-integer slice length in wide pointer",
286 // We do not check that `len * elem_size <= isize::MAX`:
287 // that is only required for references, and there it falls out of the
288 // "dereferenceable" check performed by Stacked Borrows.
291 // Unsized, but not wide.
293 _ => bug!("Unexpected unsized type tail: {:?}", tail),
299 /// Check a reference or `Box`.
300 fn check_safe_pointer(
302 value: OpTy<'tcx, M::PointerTag>,
304 ) -> InterpResult<'tcx> {
305 let value = self.ecx.read_immediate(value)?;
306 // Handle wide pointers.
307 // Check metadata early, for better diagnostics
308 let place = try_validation!(
309 self.ecx.ref_to_mplace(value),
310 format_args!("uninitialized {}", kind),
313 if place.layout.is_unsized() {
314 self.check_wide_ptr_meta(place.meta, place.layout)?;
316 // Make sure this is dereferenceable and all.
317 let size_and_align = match self.ecx.size_and_align_of(place.meta, place.layout) {
319 Err(err) => match err.kind {
320 err_ub!(InvalidMeta(msg)) => throw_validation_failure!(
321 format_args!("invalid {} metadata: {}", kind, msg),
324 _ => bug!("unexpected error during ptr size_and_align_of: {}", err),
327 let (size, align) = size_and_align
328 // for the purpose of validity, consider foreign types to have
329 // alignment and size determined by the layout (size will be 0,
330 // alignment should take attributes into account).
331 .unwrap_or_else(|| (place.layout.size, place.layout.align.abi));
332 let ptr: Option<_> = match self.ecx.memory.check_ptr_access_align(
336 CheckInAllocMsg::InboundsTest,
341 "{:?} did not pass access check for size {:?}, align {:?}",
342 place.ptr, size, align
345 err_ub!(InvalidIntPointerUsage(0)) => {
346 throw_validation_failure!(format_args!("a NULL {}", kind), self.path)
348 err_ub!(InvalidIntPointerUsage(i)) => throw_validation_failure!(
349 format_args!("a {} to unallocated address {}", kind, i),
352 err_ub!(AlignmentCheckFailed { required, has }) => throw_validation_failure!(
354 "an unaligned {} (required {} byte alignment but found {})",
361 err_unsup!(ReadBytesAsPointer) => throw_validation_failure!(
362 format_args!("a dangling {} (created from integer)", kind),
365 err_ub!(PointerOutOfBounds { .. }) => throw_validation_failure!(
367 "a dangling {} (going beyond the bounds of its allocation)",
372 // This cannot happen during const-eval (because interning already detects
373 // dangling pointers), but it can happen in Miri.
374 err_ub!(PointerUseAfterFree(_)) => throw_validation_failure!(
375 format_args!("a dangling {} (use-after-free)", kind),
378 _ => bug!("Unexpected error during ptr inbounds test: {}", err),
382 // Recursive checking
383 if let Some(ref mut ref_tracking) = self.ref_tracking_for_consts {
384 if let Some(ptr) = ptr {
386 // Skip validation entirely for some external statics
387 let alloc_kind = self.ecx.tcx.alloc_map.lock().get(ptr.alloc_id);
388 if let Some(GlobalAlloc::Static(did)) = alloc_kind {
389 // See const_eval::machine::MemoryExtra::can_access_statics for why
390 // this check is so important.
391 // This check is reachable when the const just referenced the static,
392 // but never read it (so we never entered `before_access_global`).
393 // We also need to do it here instead of going on to avoid running
394 // into the `before_access_global` check during validation.
395 if !self.may_ref_to_static && self.ecx.tcx.is_static(did) {
396 throw_validation_failure!(
397 format_args!("a {} pointing to a static variable", kind),
401 // `extern static` cannot be validated as they have no body.
402 // FIXME: Statics from other crates are also skipped.
403 // They might be checked at a different type, but for now we
404 // want to avoid recursing too deeply. We might miss const-invalid data,
405 // but things are still sound otherwise (in particular re: consts
406 // referring to statics).
407 if !did.is_local() || self.ecx.tcx.is_foreign_item(did) {
412 // Proceed recursively even for ZST, no reason to skip them!
413 // `!` is a ZST and we want to validate it.
414 // Normalize before handing `place` to tracking because that will
415 // check for duplicates.
416 let place = if size.bytes() > 0 {
417 self.ecx.force_mplace_ptr(place).expect("we already bounds-checked")
421 let path = &self.path;
422 ref_tracking.track(place, || {
423 // We need to clone the path anyway, make sure it gets created
424 // with enough space for the additional `Deref`.
425 let mut new_path = Vec::with_capacity(path.len() + 1);
426 new_path.clone_from(path);
427 new_path.push(PathElem::Deref);
434 /// Check if this is a value of primitive type, and if yes check the validity of the value
435 /// at that type. Return `true` if the type is indeed primitive.
436 fn try_visit_primitive(
438 value: OpTy<'tcx, M::PointerTag>,
439 ) -> InterpResult<'tcx, bool> {
440 // Go over all the primitive types
441 let ty = value.layout.ty;
444 let value = self.ecx.read_scalar(value)?;
445 try_validation!(value.to_bool(), value, self.path, "a boolean");
449 let value = self.ecx.read_scalar(value)?;
450 try_validation!(value.to_char(), value, self.path, "a valid unicode codepoint");
453 ty::Float(_) | ty::Int(_) | ty::Uint(_) => {
454 let value = self.ecx.read_scalar(value)?;
455 // NOTE: Keep this in sync with the array optimization for int/float
457 if self.ref_tracking_for_consts.is_some() {
458 // Integers/floats in CTFE: Must be scalar bits, pointers are dangerous
459 let is_bits = value.not_undef().map_or(false, |v| v.is_bits());
461 throw_validation_failure!(
464 "initialized plain (non-pointer) bytes"
468 // At run-time, for now, we accept *anything* for these types, including
469 // undef. We should fix that, but let's start low.
474 // We are conservative with undef for integers, but try to
475 // actually enforce the strict rules for raw pointers (mostly because
476 // that lets us re-use `ref_to_mplace`).
477 let place = try_validation!(
478 self.ecx.ref_to_mplace(self.ecx.read_immediate(value)?),
479 "uninitialized raw pointer",
482 if place.layout.is_unsized() {
483 self.check_wide_ptr_meta(place.meta, place.layout)?;
488 self.check_safe_pointer(value, "reference")?;
491 ty::Adt(def, ..) if def.is_box() => {
492 self.check_safe_pointer(value, "box")?;
496 let value = self.ecx.read_scalar(value)?;
497 let _fn = try_validation!(
498 value.not_undef().and_then(|ptr| self.ecx.memory.get_fn(ptr)),
503 // FIXME: Check if the signature matches
506 ty::Never => throw_validation_failure!("a value of the never type `!`", self.path),
507 ty::Foreign(..) | ty::FnDef(..) => {
511 // The above should be all the (inhabited) primitive types. The rest is compound, we
512 // check them by visiting their fields/variants.
513 // (`Str` UTF-8 check happens in `visit_aggregate`, too.)
521 | ty::Generator(..) => Ok(false),
522 // Some types only occur during typechecking, they have no layout.
523 // We should not see them here and we could not check them anyway.
526 | ty::Placeholder(..)
530 | ty::UnnormalizedProjection(..)
532 | ty::GeneratorWitness(..) => bug!("Encountered invalid type {:?}", ty),
538 op: OpTy<'tcx, M::PointerTag>,
539 scalar_layout: &Scalar,
540 ) -> InterpResult<'tcx> {
541 let value = self.ecx.read_scalar(op)?;
542 let valid_range = &scalar_layout.valid_range;
543 let (lo, hi) = valid_range.clone().into_inner();
544 // Determine the allowed range
545 // `max_hi` is as big as the size fits
546 let max_hi = u128::MAX >> (128 - op.layout.size.bits());
547 assert!(hi <= max_hi);
548 // We could also write `(hi + 1) % (max_hi + 1) == lo` but `max_hi + 1` overflows for `u128`
549 if (lo == 0 && hi == max_hi) || (hi + 1 == lo) {
553 // At least one value is excluded. Get the bits.
554 let value = try_validation!(
558 format_args!("something {}", wrapping_range_format(valid_range, max_hi),)
560 let bits = match value.to_bits_or_ptr(op.layout.size, self.ecx) {
562 if lo == 1 && hi == max_hi {
563 // Only NULL is the niche. So make sure the ptr is NOT NULL.
564 if self.ecx.memory.ptr_may_be_null(ptr) {
565 throw_validation_failure!(
566 "a potentially NULL pointer",
569 "something that cannot possibly fail to be {}",
570 wrapping_range_format(valid_range, max_hi)
576 // Conservatively, we reject, because the pointer *could* have a bad
578 throw_validation_failure!(
582 "something that cannot possibly fail to be {}",
583 wrapping_range_format(valid_range, max_hi)
590 // Now compare. This is slightly subtle because this is a special "wrap-around" range.
591 if wrapping_range_contains(&valid_range, bits) {
594 throw_validation_failure!(
597 format_args!("something {}", wrapping_range_format(valid_range, max_hi))
603 impl<'rt, 'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> ValueVisitor<'mir, 'tcx, M>
604 for ValidityVisitor<'rt, 'mir, 'tcx, M>
606 type V = OpTy<'tcx, M::PointerTag>;
609 fn ecx(&self) -> &InterpCx<'mir, 'tcx, M> {
616 old_op: OpTy<'tcx, M::PointerTag>,
618 new_op: OpTy<'tcx, M::PointerTag>,
619 ) -> InterpResult<'tcx> {
620 let elem = self.aggregate_field_path_elem(old_op.layout, field);
621 self.visit_elem(new_op, elem)
627 old_op: OpTy<'tcx, M::PointerTag>,
628 variant_id: VariantIdx,
629 new_op: OpTy<'tcx, M::PointerTag>,
630 ) -> InterpResult<'tcx> {
631 let name = match old_op.layout.ty.kind {
632 ty::Adt(adt, _) => PathElem::Variant(adt.variants[variant_id].ident.name),
633 // Generators also have variants
634 ty::Generator(..) => PathElem::GeneratorState(variant_id),
635 _ => bug!("Unexpected type with variant: {:?}", old_op.layout.ty),
637 self.visit_elem(new_op, name)
643 _op: OpTy<'tcx, M::PointerTag>,
644 _fields: NonZeroUsize,
645 ) -> InterpResult<'tcx> {
650 fn visit_value(&mut self, op: OpTy<'tcx, M::PointerTag>) -> InterpResult<'tcx> {
651 trace!("visit_value: {:?}, {:?}", *op, op.layout);
653 // Check primitive types -- the leafs of our recursive descend.
654 if self.try_visit_primitive(op)? {
657 // Sanity check: `builtin_deref` does not know any pointers that are not primitive.
658 assert!(op.layout.ty.builtin_deref(true).is_none());
660 // Recursively walk the type. Translate some possible errors to something nicer.
661 match self.walk_value(op) {
663 Err(err) => match err.kind {
664 err_ub!(InvalidDiscriminant(val)) => {
665 throw_validation_failure!(val, self.path, "a valid enum discriminant")
667 err_unsup!(ReadPointerAsBytes) => {
668 throw_validation_failure!("a pointer", self.path, "plain (non-pointer) bytes")
670 // Propagate upwards (that will also check for unexpected errors).
671 _ => return Err(err),
675 // *After* all of this, check the ABI. We need to check the ABI to handle
676 // types like `NonNull` where the `Scalar` info is more restrictive than what
677 // the fields say (`rustc_layout_scalar_valid_range_start`).
678 // But in most cases, this will just propagate what the fields say,
679 // and then we want the error to point at the field -- so, first recurse,
682 // FIXME: We could avoid some redundant checks here. For newtypes wrapping
683 // scalars, we do the same check on every "level" (e.g., first we check
684 // MyNewtype and then the scalar in there).
685 match op.layout.abi {
686 Abi::Uninhabited => {
687 throw_validation_failure!(
688 format_args!("a value of uninhabited type {:?}", op.layout.ty),
692 Abi::Scalar(ref scalar_layout) => {
693 self.visit_scalar(op, scalar_layout)?;
695 Abi::ScalarPair { .. } | Abi::Vector { .. } => {
696 // These have fields that we already visited above, so we already checked
697 // all their scalar-level restrictions.
698 // There is also no equivalent to `rustc_layout_scalar_valid_range_start`
699 // that would make skipping them here an issue.
701 Abi::Aggregate { .. } => {
711 op: OpTy<'tcx, M::PointerTag>,
712 fields: impl Iterator<Item = InterpResult<'tcx, Self::V>>,
713 ) -> InterpResult<'tcx> {
714 match op.layout.ty.kind {
716 let mplace = op.assert_mem_place(self.ecx); // strings are never immediate
718 self.ecx.read_str(mplace),
719 "uninitialized or non-UTF-8 data in str",
723 ty::Array(tys, ..) | ty::Slice(tys)
725 // This optimization applies for types that can hold arbitrary bytes (such as
726 // integer and floating point types) or for structs or tuples with no fields.
727 // FIXME(wesleywiser) This logic could be extended further to arbitrary structs
728 // or tuples made up of integer/floating point types or inhabited ZSTs with no
731 ty::Int(..) | ty::Uint(..) | ty::Float(..) => true,
736 // Optimized handling for arrays of integer/float type.
738 // Arrays cannot be immediate, slices are never immediate.
739 let mplace = op.assert_mem_place(self.ecx);
740 // This is the length of the array/slice.
741 let len = mplace.len(self.ecx)?;
742 // Zero length slices have nothing to be checked.
746 // This is the element type size.
747 let layout = self.ecx.layout_of(tys)?;
748 // This is the size in bytes of the whole array. (This checks for overflow.)
749 let size = layout.size * len;
750 // Size is not 0, get a pointer.
751 let ptr = self.ecx.force_ptr(mplace.ptr)?;
753 // Optimization: we just check the entire range at once.
754 // NOTE: Keep this in sync with the handling of integer and float
755 // types above, in `visit_primitive`.
756 // In run-time mode, we accept pointers in here. This is actually more
757 // permissive than a per-element check would be, e.g., we accept
758 // an &[u8] that contains a pointer even though bytewise checking would
759 // reject it. However, that's good: We don't inherently want
760 // to reject those pointers, we just do not have the machinery to
761 // talk about parts of a pointer.
762 // We also accept undef, for consistency with the slow path.
763 match self.ecx.memory.get_raw(ptr.alloc_id)?.check_bytes(
767 /*allow_ptr_and_undef*/ self.ref_tracking_for_consts.is_none(),
769 // In the happy case, we needn't check anything else.
771 // Some error happened, try to provide a more detailed description.
773 // For some errors we might be able to provide extra information
775 err_ub!(InvalidUndefBytes(Some(ptr))) => {
776 // Some byte was uninitialized, determine which
777 // element that byte belongs to so we can
779 let i = usize::try_from(ptr.offset.bytes() / layout.size.bytes())
781 self.path.push(PathElem::ArrayElem(i));
783 throw_validation_failure!("uninitialized bytes", self.path)
785 // Other errors shouldn't be possible
786 _ => return Err(err),
791 // Fast path for arrays and slices of ZSTs. We only need to check a single ZST element
792 // of an array and not all of them, because there's only a single value of a specific
793 // ZST type, so either validation fails for all elements or none.
794 ty::Array(tys, ..) | ty::Slice(tys) if self.ecx.layout_of(tys)?.is_zst() => {
795 // Validate just the first element
796 self.walk_aggregate(op, fields.take(1))?
799 self.walk_aggregate(op, fields)? // default handler
806 impl<'mir, 'tcx: 'mir, M: Machine<'mir, 'tcx>> InterpCx<'mir, 'tcx, M> {
807 fn validate_operand_internal(
809 op: OpTy<'tcx, M::PointerTag>,
811 ref_tracking_for_consts: Option<
812 &mut RefTracking<MPlaceTy<'tcx, M::PointerTag>, Vec<PathElem>>,
814 may_ref_to_static: bool,
815 ) -> InterpResult<'tcx> {
816 trace!("validate_operand_internal: {:?}, {:?}", *op, op.layout.ty);
818 // Construct a visitor
820 ValidityVisitor { path, ref_tracking_for_consts, may_ref_to_static, ecx: self };
822 // Try to cast to ptr *once* instead of all the time.
823 let op = self.force_op_ptr(op).unwrap_or(op);
826 match visitor.visit_value(op) {
828 // We should only get validation errors here. Avoid other errors as
829 // those do not show *where* in the value the issue lies.
830 Err(err) if matches!(err.kind, err_ub!(ValidationFailure { .. })) => Err(err),
831 Err(err) => bug!("Unexpected error during validation: {}", err),
835 /// This function checks the data at `op` to be const-valid.
836 /// `op` is assumed to cover valid memory if it is an indirect operand.
837 /// It will error if the bits at the destination do not match the ones described by the layout.
839 /// `ref_tracking` is used to record references that we encounter so that they
840 /// can be checked recursively by an outside driving loop.
842 /// `may_ref_to_static` controls whether references are allowed to point to statics.
844 pub fn const_validate_operand(
846 op: OpTy<'tcx, M::PointerTag>,
848 ref_tracking: &mut RefTracking<MPlaceTy<'tcx, M::PointerTag>, Vec<PathElem>>,
849 may_ref_to_static: bool,
850 ) -> InterpResult<'tcx> {
851 self.validate_operand_internal(op, path, Some(ref_tracking), may_ref_to_static)
854 /// This function checks the data at `op` to be runtime-valid.
855 /// `op` is assumed to cover valid memory if it is an indirect operand.
856 /// It will error if the bits at the destination do not match the ones described by the layout.
858 pub fn validate_operand(&self, op: OpTy<'tcx, M::PointerTag>) -> InterpResult<'tcx> {
859 self.validate_operand_internal(op, vec![], None, false)