1 //! The memory subsystem.
3 //! Generally, we use `Pointer` to denote memory addresses. However, some operations
4 //! have a "size"-like parameter, and they take `Scalar` for the address because
5 //! if the size is 0, then the pointer can also be a (properly aligned, non-NULL)
6 //! integer. It is crucial that these operations call `check_align` *before*
7 //! short-circuiting the empty case!
9 use std::collections::VecDeque;
13 use rustc::ty::{self, Instance, ParamEnv, query::TyCtxtAt};
14 use rustc::ty::layout::{Align, TargetDataLayout, Size, HasDataLayout};
15 use rustc_data_structures::fx::{FxHashSet, FxHashMap};
17 use syntax::ast::Mutability;
20 Pointer, AllocId, Allocation, GlobalId, AllocationExtra,
21 InterpResult, Scalar, GlobalAlloc, PointerArithmetic,
22 Machine, AllocMap, MayLeak, ErrorHandled, CheckInAllocMsg,
25 #[derive(Debug, PartialEq, Copy, Clone)]
26 pub enum MemoryKind<T> {
27 /// Stack memory. Error if deallocated except during a stack pop.
29 /// Memory backing vtables. Error if ever deallocated.
31 /// Memory allocated by `caller_location` intrinsic. Error if ever deallocated.
33 /// Additional memory kinds a machine wishes to distinguish from the builtin ones.
37 impl<T: MayLeak> MayLeak for MemoryKind<T> {
39 fn may_leak(self) -> bool {
41 MemoryKind::Stack => false,
42 MemoryKind::Vtable => true,
43 MemoryKind::CallerLocation => true,
44 MemoryKind::Machine(k) => k.may_leak()
49 /// Used by `get_size_and_align` to indicate whether the allocation needs to be live.
50 #[derive(Debug, Copy, Clone)]
52 /// Allocation must be live and not a function pointer.
54 /// Allocations needs to be live, but may be a function pointer.
56 /// Allocation may be dead.
60 /// The value of a function pointer.
61 #[derive(Debug, Copy, Clone)]
62 pub enum FnVal<'tcx, Other> {
63 Instance(Instance<'tcx>),
67 impl<'tcx, Other> FnVal<'tcx, Other> {
68 pub fn as_instance(self) -> InterpResult<'tcx, Instance<'tcx>> {
70 FnVal::Instance(instance) =>
72 FnVal::Other(_) => throw_unsup_format!(
73 "'foreign' function pointers are not supported in this context"
79 // `Memory` has to depend on the `Machine` because some of its operations
80 // (e.g., `get`) call a `Machine` hook.
81 pub struct Memory<'mir, 'tcx, M: Machine<'mir, 'tcx>> {
82 /// Allocations local to this instance of the miri engine. The kind
83 /// helps ensure that the same mechanism is used for allocation and
84 /// deallocation. When an allocation is not found here, it is a
85 /// static and looked up in the `tcx` for read access. Some machines may
86 /// have to mutate this map even on a read-only access to a static (because
87 /// they do pointer provenance tracking and the allocations in `tcx` have
88 /// the wrong type), so we let the machine override this type.
89 /// Either way, if the machine allows writing to a static, doing so will
90 /// create a copy of the static allocation here.
91 // FIXME: this should not be public, but interning currently needs access to it
92 pub(super) alloc_map: M::MemoryMap,
94 /// Map for "extra" function pointers.
95 extra_fn_ptr_map: FxHashMap<AllocId, M::ExtraFnVal>,
97 /// To be able to compare pointers with NULL, and to check alignment for accesses
98 /// to ZSTs (where pointers may dangle), we keep track of the size even for allocations
99 /// that do not exist any more.
100 // FIXME: this should not be public, but interning currently needs access to it
101 pub(super) dead_alloc_map: FxHashMap<AllocId, (Size, Align)>,
103 /// Extra data added by the machine.
104 pub extra: M::MemoryExtra,
106 /// Lets us implement `HasDataLayout`, which is awfully convenient.
107 pub tcx: TyCtxtAt<'tcx>,
110 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> HasDataLayout for Memory<'mir, 'tcx, M> {
112 fn data_layout(&self) -> &TargetDataLayout {
113 &self.tcx.data_layout
117 // FIXME: Really we shouldn't clone memory, ever. Snapshot machinery should instead
118 // carefully copy only the reachable parts.
119 impl<'mir, 'tcx, M> Clone for Memory<'mir, 'tcx, M>
121 M: Machine<'mir, 'tcx, PointerTag = (), AllocExtra = (), MemoryExtra = ()>,
122 M::MemoryMap: AllocMap<AllocId, (MemoryKind<M::MemoryKinds>, Allocation)>,
124 fn clone(&self) -> Self {
126 alloc_map: self.alloc_map.clone(),
127 extra_fn_ptr_map: self.extra_fn_ptr_map.clone(),
128 dead_alloc_map: self.dead_alloc_map.clone(),
135 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
136 pub fn new(tcx: TyCtxtAt<'tcx>, extra: M::MemoryExtra) -> Self {
138 alloc_map: M::MemoryMap::default(),
139 extra_fn_ptr_map: FxHashMap::default(),
140 dead_alloc_map: FxHashMap::default(),
146 /// Call this to turn untagged "global" pointers (obtained via `tcx`) into
147 /// the *canonical* machine pointer to the allocation. Must never be used
148 /// for any other pointers!
150 /// This represents a *direct* access to that memory, as opposed to access
151 /// through a pointer that was created by the program.
153 pub fn tag_static_base_pointer(&self, ptr: Pointer) -> Pointer<M::PointerTag> {
154 ptr.with_tag(M::tag_static_base_pointer(&self.extra, ptr.alloc_id))
157 pub fn create_fn_alloc(
159 fn_val: FnVal<'tcx, M::ExtraFnVal>,
160 ) -> Pointer<M::PointerTag>
162 let id = match fn_val {
163 FnVal::Instance(instance) => self.tcx.alloc_map.lock().create_fn_alloc(instance),
164 FnVal::Other(extra) => {
165 // FIXME(RalfJung): Should we have a cache here?
166 let id = self.tcx.alloc_map.lock().reserve();
167 let old = self.extra_fn_ptr_map.insert(id, extra);
168 assert!(old.is_none());
172 self.tag_static_base_pointer(Pointer::from(id))
179 kind: MemoryKind<M::MemoryKinds>,
180 ) -> Pointer<M::PointerTag> {
181 let alloc = Allocation::undef(size, align);
182 self.allocate_with(alloc, kind)
185 pub fn allocate_static_bytes(
188 kind: MemoryKind<M::MemoryKinds>,
189 ) -> Pointer<M::PointerTag> {
190 let alloc = Allocation::from_byte_aligned_bytes(bytes);
191 self.allocate_with(alloc, kind)
194 pub fn allocate_with(
197 kind: MemoryKind<M::MemoryKinds>,
198 ) -> Pointer<M::PointerTag> {
199 let id = self.tcx.alloc_map.lock().reserve();
200 debug_assert_ne!(Some(kind), M::STATIC_KIND.map(MemoryKind::Machine),
201 "dynamically allocating static memory");
202 let (alloc, tag) = M::init_allocation_extra(&self.extra, id, Cow::Owned(alloc), Some(kind));
203 self.alloc_map.insert(id, (kind, alloc.into_owned()));
204 Pointer::from(id).with_tag(tag)
209 ptr: Pointer<M::PointerTag>,
210 old_size_and_align: Option<(Size, Align)>,
213 kind: MemoryKind<M::MemoryKinds>,
214 ) -> InterpResult<'tcx, Pointer<M::PointerTag>> {
215 if ptr.offset.bytes() != 0 {
216 throw_unsup!(ReallocateNonBasePtr)
219 // For simplicities' sake, we implement reallocate as "alloc, copy, dealloc".
220 // This happens so rarely, the perf advantage is outweighed by the maintenance cost.
221 let new_ptr = self.allocate(new_size, new_align, kind);
222 let old_size = match old_size_and_align {
223 Some((size, _align)) => size,
224 None => self.get_raw(ptr.alloc_id)?.size,
229 old_size.min(new_size),
230 /*nonoverlapping*/ true,
232 self.deallocate(ptr, old_size_and_align, kind)?;
237 /// Deallocate a local, or do nothing if that local has been made into a static
238 pub fn deallocate_local(&mut self, ptr: Pointer<M::PointerTag>) -> InterpResult<'tcx> {
239 // The allocation might be already removed by static interning.
240 // This can only really happen in the CTFE instance, not in miri.
241 if self.alloc_map.contains_key(&ptr.alloc_id) {
242 self.deallocate(ptr, None, MemoryKind::Stack)
250 ptr: Pointer<M::PointerTag>,
251 old_size_and_align: Option<(Size, Align)>,
252 kind: MemoryKind<M::MemoryKinds>,
253 ) -> InterpResult<'tcx> {
254 trace!("deallocating: {}", ptr.alloc_id);
256 if ptr.offset.bytes() != 0 {
257 throw_unsup!(DeallocateNonBasePtr)
260 let (alloc_kind, mut alloc) = match self.alloc_map.remove(&ptr.alloc_id) {
261 Some(alloc) => alloc,
263 // Deallocating static memory -- always an error
264 return Err(match self.tcx.alloc_map.lock().get(ptr.alloc_id) {
265 Some(GlobalAlloc::Function(..)) => err_unsup!(DeallocatedWrongMemoryKind(
266 "function".to_string(),
267 format!("{:?}", kind),
269 Some(GlobalAlloc::Static(..)) | Some(GlobalAlloc::Memory(..)) => err_unsup!(
270 DeallocatedWrongMemoryKind("static".to_string(), format!("{:?}", kind))
272 None => err_unsup!(DoubleFree),
278 if alloc_kind != kind {
279 throw_unsup!(DeallocatedWrongMemoryKind(
280 format!("{:?}", alloc_kind),
281 format!("{:?}", kind),
284 if let Some((size, align)) = old_size_and_align {
285 if size != alloc.size || align != alloc.align {
286 let bytes = alloc.size;
287 throw_unsup!(IncorrectAllocationInformation(size, bytes, align, alloc.align))
291 // Let the machine take some extra action
292 let size = alloc.size;
293 AllocationExtra::memory_deallocated(&mut alloc, ptr, size)?;
295 // Don't forget to remember size and align of this now-dead allocation
296 let old = self.dead_alloc_map.insert(
298 (alloc.size, alloc.align)
301 bug!("Nothing can be deallocated twice");
307 /// Check if the given scalar is allowed to do a memory access of given `size`
308 /// and `align`. On success, returns `None` for zero-sized accesses (where
309 /// nothing else is left to do) and a `Pointer` to use for the actual access otherwise.
310 /// Crucially, if the input is a `Pointer`, we will test it for liveness
311 /// *even if* the size is 0.
313 /// Everyone accessing memory based on a `Scalar` should use this method to get the
314 /// `Pointer` they need. And even if you already have a `Pointer`, call this method
315 /// to make sure it is sufficiently aligned and not dangling. Not doing that may
318 /// Most of the time you should use `check_mplace_access`, but when you just have a pointer,
319 /// this method is still appropriate.
321 pub fn check_ptr_access(
323 sptr: Scalar<M::PointerTag>,
326 ) -> InterpResult<'tcx, Option<Pointer<M::PointerTag>>> {
327 let align = if M::CHECK_ALIGN { Some(align) } else { None };
328 self.check_ptr_access_align(sptr, size, align, CheckInAllocMsg::MemoryAccessTest)
331 /// Like `check_ptr_access`, but *definitely* checks alignment when `align`
332 /// is `Some` (overriding `M::CHECK_ALIGN`). Also lets the caller control
333 /// the error message for the out-of-bounds case.
334 pub fn check_ptr_access_align(
336 sptr: Scalar<M::PointerTag>,
338 align: Option<Align>,
339 msg: CheckInAllocMsg,
340 ) -> InterpResult<'tcx, Option<Pointer<M::PointerTag>>> {
341 fn check_offset_align(offset: u64, align: Align) -> InterpResult<'static> {
342 if offset % align.bytes() == 0 {
345 // The biggest power of two through which `offset` is divisible.
346 let offset_pow2 = 1 << offset.trailing_zeros();
347 throw_unsup!(AlignmentCheckFailed {
348 has: Align::from_bytes(offset_pow2).unwrap(),
354 // Normalize to a `Pointer` if we definitely need one.
355 let normalized = if size.bytes() == 0 {
356 // Can be an integer, just take what we got. We do NOT `force_bits` here;
357 // if this is already a `Pointer` we want to do the bounds checks!
360 // A "real" access, we must get a pointer.
361 Scalar::from(self.force_ptr(sptr)?)
363 Ok(match normalized.to_bits_or_ptr(self.pointer_size(), self) {
365 let bits = bits as u64; // it's ptr-sized
366 assert!(size.bytes() == 0);
369 throw_unsup!(InvalidNullPointerUsage)
372 if let Some(align) = align {
373 check_offset_align(bits, align)?;
378 let (allocation_size, alloc_align) =
379 self.get_size_and_align(ptr.alloc_id, AllocCheck::Dereferenceable)?;
380 // Test bounds. This also ensures non-NULL.
381 // It is sufficient to check this for the end pointer. The addition
382 // checks for overflow.
383 let end_ptr = ptr.offset(size, self)?;
384 end_ptr.check_inbounds_alloc(allocation_size, msg)?;
385 // Test align. Check this last; if both bounds and alignment are violated
386 // we want the error to be about the bounds.
387 if let Some(align) = align {
388 if alloc_align.bytes() < align.bytes() {
389 // The allocation itself is not aligned enough.
390 // FIXME: Alignment check is too strict, depending on the base address that
391 // got picked we might be aligned even if this check fails.
392 // We instead have to fall back to converting to an integer and checking
393 // the "real" alignment.
394 throw_unsup!(AlignmentCheckFailed {
399 check_offset_align(ptr.offset.bytes(), align)?;
402 // We can still be zero-sized in this branch, in which case we have to
404 if size.bytes() == 0 { None } else { Some(ptr) }
409 /// Test if the pointer might be NULL.
410 pub fn ptr_may_be_null(
412 ptr: Pointer<M::PointerTag>,
414 let (size, _align) = self.get_size_and_align(ptr.alloc_id, AllocCheck::MaybeDead)
415 .expect("alloc info with MaybeDead cannot fail");
416 ptr.check_inbounds_alloc(size, CheckInAllocMsg::NullPointerTest).is_err()
420 /// Allocation accessors
421 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
422 /// Helper function to obtain the global (tcx) allocation for a static.
423 /// This attempts to return a reference to an existing allocation if
424 /// one can be found in `tcx`. That, however, is only possible if `tcx` and
425 /// this machine use the same pointer tag, so it is indirected through
426 /// `M::tag_allocation`.
428 /// Notice that every static has two `AllocId` that will resolve to the same
429 /// thing here: one maps to `GlobalAlloc::Static`, this is the "lazy" ID,
430 /// and the other one is maps to `GlobalAlloc::Memory`, this is returned by
431 /// `const_eval_raw` and it is the "resolved" ID.
432 /// The resolved ID is never used by the interpreted progrma, it is hidden.
433 /// The `GlobalAlloc::Memory` branch here is still reachable though; when a static
434 /// contains a reference to memory that was created during its evaluation (i.e., not to
435 /// another static), those inner references only exist in "resolved" form.
437 memory_extra: &M::MemoryExtra,
440 ) -> InterpResult<'tcx, Cow<'tcx, Allocation<M::PointerTag, M::AllocExtra>>> {
441 let alloc = tcx.alloc_map.lock().get(id);
442 let alloc = match alloc {
443 Some(GlobalAlloc::Memory(mem)) =>
445 Some(GlobalAlloc::Function(..)) =>
446 throw_unsup!(DerefFunctionPointer),
448 throw_unsup!(DanglingPointerDeref),
449 Some(GlobalAlloc::Static(def_id)) => {
450 // We got a "lazy" static that has not been computed yet.
451 if tcx.is_foreign_item(def_id) {
452 trace!("static_alloc: foreign item {:?}", def_id);
453 M::find_foreign_static(tcx.tcx, def_id)?
455 trace!("static_alloc: Need to compute {:?}", def_id);
456 let instance = Instance::mono(tcx.tcx, def_id);
461 // use the raw query here to break validation cycles. Later uses of the static
462 // will call the full query anyway
463 let raw_const = tcx.const_eval_raw(ty::ParamEnv::reveal_all().and(gid))
465 // no need to report anything, the const_eval call takes care of that
467 assert!(tcx.is_static(def_id));
469 ErrorHandled::Reported =>
470 err_inval!(ReferencedConstant),
471 ErrorHandled::TooGeneric =>
472 err_inval!(TooGeneric),
475 // Make sure we use the ID of the resolved memory, not the lazy one!
476 let id = raw_const.alloc_id;
477 let allocation = tcx.alloc_map.lock().unwrap_memory(id);
479 M::before_access_static(allocation)?;
480 Cow::Borrowed(allocation)
484 // We got tcx memory. Let the machine initialize its "extra" stuff.
485 let (alloc, tag) = M::init_allocation_extra(
487 id, // always use the ID we got as input, not the "hidden" one.
489 M::STATIC_KIND.map(MemoryKind::Machine),
491 debug_assert_eq!(tag, M::tag_static_base_pointer(memory_extra, id));
495 /// Gives raw access to the `Allocation`, without bounds or alignment checks.
496 /// Use the higher-level, `PlaceTy`- and `OpTy`-based APIs in `InterpCtx` instead!
500 ) -> InterpResult<'tcx, &Allocation<M::PointerTag, M::AllocExtra>> {
501 // The error type of the inner closure here is somewhat funny. We have two
502 // ways of "erroring": An actual error, or because we got a reference from
503 // `get_static_alloc` that we can actually use directly without inserting anything anywhere.
504 // So the error type is `InterpResult<'tcx, &Allocation<M::PointerTag>>`.
505 let a = self.alloc_map.get_or(id, || {
506 let alloc = Self::get_static_alloc(&self.extra, self.tcx, id).map_err(Err)?;
508 Cow::Borrowed(alloc) => {
509 // We got a ref, cheaply return that as an "error" so that the
510 // map does not get mutated.
513 Cow::Owned(alloc) => {
514 // Need to put it into the map and return a ref to that
515 let kind = M::STATIC_KIND.expect(
516 "I got an owned allocation that I have to copy but the machine does \
517 not expect that to happen"
519 Ok((MemoryKind::Machine(kind), alloc))
523 // Now unpack that funny error type
530 /// Gives raw mutable access to the `Allocation`, without bounds or alignment checks.
531 /// Use the higher-level, `PlaceTy`- and `OpTy`-based APIs in `InterpCtx` instead!
535 ) -> InterpResult<'tcx, &mut Allocation<M::PointerTag, M::AllocExtra>> {
537 let memory_extra = &self.extra;
538 let a = self.alloc_map.get_mut_or(id, || {
539 // Need to make a copy, even if `get_static_alloc` is able
540 // to give us a cheap reference.
541 let alloc = Self::get_static_alloc(memory_extra, tcx, id)?;
542 if alloc.mutability == Mutability::Immutable {
543 throw_unsup!(ModifiedConstantMemory)
545 match M::STATIC_KIND {
546 Some(kind) => Ok((MemoryKind::Machine(kind), alloc.into_owned())),
547 None => throw_unsup!(ModifiedStatic),
550 // Unpack the error type manually because type inference doesn't
551 // work otherwise (and we cannot help it because `impl Trait`)
556 if a.mutability == Mutability::Immutable {
557 throw_unsup!(ModifiedConstantMemory)
564 /// Obtain the size and alignment of an allocation, even if that allocation has
565 /// been deallocated.
567 /// If `liveness` is `AllocCheck::MaybeDead`, this function always returns `Ok`.
568 pub fn get_size_and_align(
571 liveness: AllocCheck,
572 ) -> InterpResult<'static, (Size, Align)> {
573 // # Regular allocations
574 // Don't use `self.get_raw` here as that will
575 // a) cause cycles in case `id` refers to a static
576 // b) duplicate a static's allocation in miri
577 if let Some((_, alloc)) = self.alloc_map.get(id) {
578 return Ok((alloc.size, alloc.align));
581 // # Function pointers
582 // (both global from `alloc_map` and local from `extra_fn_ptr_map`)
583 if let Ok(_) = self.get_fn_alloc(id) {
584 return if let AllocCheck::Dereferenceable = liveness {
585 // The caller requested no function pointers.
586 throw_unsup!(DerefFunctionPointer)
588 Ok((Size::ZERO, Align::from_bytes(1).unwrap()))
593 // Can't do this in the match argument, we may get cycle errors since the lock would
594 // be held throughout the match.
595 let alloc = self.tcx.alloc_map.lock().get(id);
597 Some(GlobalAlloc::Static(did)) => {
598 // Use size and align of the type.
599 let ty = self.tcx.type_of(did);
600 let layout = self.tcx.layout_of(ParamEnv::empty().and(ty)).unwrap();
601 Ok((layout.size, layout.align.abi))
603 Some(GlobalAlloc::Memory(alloc)) =>
604 // Need to duplicate the logic here, because the global allocations have
605 // different associated types than the interpreter-local ones.
606 Ok((alloc.size, alloc.align)),
607 Some(GlobalAlloc::Function(_)) =>
608 bug!("We already checked function pointers above"),
609 // The rest must be dead.
610 None => if let AllocCheck::MaybeDead = liveness {
611 // Deallocated pointers are allowed, we should be able to find
613 Ok(*self.dead_alloc_map.get(&id)
614 .expect("deallocated pointers should all be recorded in \
617 throw_unsup!(DanglingPointerDeref)
622 fn get_fn_alloc(&self, id: AllocId) -> InterpResult<'tcx, FnVal<'tcx, M::ExtraFnVal>> {
623 trace!("reading fn ptr: {}", id);
624 if let Some(extra) = self.extra_fn_ptr_map.get(&id) {
625 Ok(FnVal::Other(*extra))
627 match self.tcx.alloc_map.lock().get(id) {
628 Some(GlobalAlloc::Function(instance)) => Ok(FnVal::Instance(instance)),
629 _ => throw_unsup!(ExecuteMemory),
636 ptr: Scalar<M::PointerTag>,
637 ) -> InterpResult<'tcx, FnVal<'tcx, M::ExtraFnVal>> {
638 let ptr = self.force_ptr(ptr)?; // We definitely need a pointer value.
639 if ptr.offset.bytes() != 0 {
640 throw_unsup!(InvalidFunctionPointer)
642 self.get_fn_alloc(ptr.alloc_id)
645 pub fn mark_immutable(&mut self, id: AllocId) -> InterpResult<'tcx> {
646 self.get_raw_mut(id)?.mutability = Mutability::Immutable;
650 /// Print an allocation and all allocations it points to, recursively.
651 /// This prints directly to stderr, ignoring RUSTC_LOG! It is up to the caller to
652 /// control for this.
653 pub fn dump_alloc(&self, id: AllocId) {
654 self.dump_allocs(vec![id]);
657 fn dump_alloc_helper<Tag, Extra>(
659 allocs_seen: &mut FxHashSet<AllocId>,
660 allocs_to_print: &mut VecDeque<AllocId>,
662 alloc: &Allocation<Tag, Extra>,
667 let prefix_len = msg.len();
668 let mut relocations = vec![];
670 for i in 0..alloc.size.bytes() {
671 let i = Size::from_bytes(i);
672 if let Some(&(_, target_id)) = alloc.relocations().get(&i) {
673 if allocs_seen.insert(target_id) {
674 allocs_to_print.push_back(target_id);
676 relocations.push((i, target_id));
678 if alloc.undef_mask().is_range_defined(i, i + Size::from_bytes(1)).is_ok() {
679 // this `as usize` is fine, since `i` came from a `usize`
680 let i = i.bytes() as usize;
682 // Checked definedness (and thus range) and relocations. This access also doesn't
683 // influence interpreter execution but is only for debugging.
684 let bytes = alloc.inspect_with_undef_and_ptr_outside_interpreter(i..i+1);
685 write!(msg, "{:02x} ", bytes[0]).unwrap();
692 "{}({} bytes, alignment {}){}",
699 if !relocations.is_empty() {
701 write!(msg, "{:1$}", "", prefix_len).unwrap(); // Print spaces.
702 let mut pos = Size::ZERO;
703 let relocation_width = (self.pointer_size().bytes() - 1) * 3;
704 for (i, target_id) in relocations {
705 // this `as usize` is fine, since we can't print more chars than `usize::MAX`
706 write!(msg, "{:1$}", "", ((i - pos) * 3).bytes() as usize).unwrap();
707 let target = format!("({})", target_id);
708 // this `as usize` is fine, since we can't print more chars than `usize::MAX`
709 write!(msg, "└{0:─^1$}┘ ", target, relocation_width as usize).unwrap();
710 pos = i + self.pointer_size();
712 eprintln!("{}", msg);
716 /// Print a list of allocations and all allocations they point to, recursively.
717 /// This prints directly to stderr, ignoring RUSTC_LOG! It is up to the caller to
718 /// control for this.
719 pub fn dump_allocs(&self, mut allocs: Vec<AllocId>) {
722 let mut allocs_to_print = VecDeque::from(allocs);
723 let mut allocs_seen = FxHashSet::default();
725 while let Some(id) = allocs_to_print.pop_front() {
726 let msg = format!("Alloc {:<5} ", format!("{}:", id));
729 match self.alloc_map.get_or(id, || Err(())) {
730 Ok((kind, alloc)) => {
731 let extra = match kind {
732 MemoryKind::Stack => " (stack)".to_owned(),
733 MemoryKind::Vtable => " (vtable)".to_owned(),
734 MemoryKind::CallerLocation => " (caller_location)".to_owned(),
735 MemoryKind::Machine(m) => format!(" ({:?})", m),
737 self.dump_alloc_helper(
738 &mut allocs_seen, &mut allocs_to_print,
744 match self.tcx.alloc_map.lock().get(id) {
745 Some(GlobalAlloc::Memory(alloc)) => {
746 self.dump_alloc_helper(
747 &mut allocs_seen, &mut allocs_to_print,
748 msg, alloc, " (immutable)".to_owned()
751 Some(GlobalAlloc::Function(func)) => {
752 eprintln!("{} {}", msg, func);
754 Some(GlobalAlloc::Static(did)) => {
755 eprintln!("{} {:?}", msg, did);
758 eprintln!("{} (deallocated)", msg);
767 pub fn leak_report(&self) -> usize {
768 let leaks: Vec<_> = self.alloc_map.filter_map_collect(|&id, &(kind, _)| {
769 if kind.may_leak() { None } else { Some(id) }
773 eprintln!("### LEAK REPORT ###");
774 self.dump_allocs(leaks);
779 /// This is used by [priroda](https://github.com/oli-obk/priroda)
780 pub fn alloc_map(&self) -> &M::MemoryMap {
785 /// Reading and writing.
786 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
787 /// Reads the given number of bytes from memory. Returns them as a slice.
789 /// Performs appropriate bounds checks.
792 ptr: Scalar<M::PointerTag>,
794 ) -> InterpResult<'tcx, &[u8]> {
795 let ptr = match self.check_ptr_access(ptr, size, Align::from_bytes(1).unwrap())? {
797 None => return Ok(&[]), // zero-sized access
799 self.get_raw(ptr.alloc_id)?.get_bytes(self, ptr, size)
802 /// Reads a 0-terminated sequence of bytes from memory. Returns them as a slice.
804 /// Performs appropriate bounds checks.
805 pub fn read_c_str(&self, ptr: Scalar<M::PointerTag>) -> InterpResult<'tcx, &[u8]> {
806 let ptr = self.force_ptr(ptr)?; // We need to read at least 1 byte, so we *need* a ptr.
807 self.get_raw(ptr.alloc_id)?.read_c_str(self, ptr)
810 /// Writes the given stream of bytes into memory.
812 /// Performs appropriate bounds checks.
815 ptr: Scalar<M::PointerTag>,
816 src: impl IntoIterator<Item=u8>,
817 ) -> InterpResult<'tcx>
819 let src = src.into_iter();
820 let size = Size::from_bytes(src.size_hint().0 as u64);
821 // `write_bytes` checks that this lower bound matches the upper bound matches reality.
822 let ptr = match self.check_ptr_access(ptr, size, Align::from_bytes(1).unwrap())? {
824 None => return Ok(()), // zero-sized access
826 let tcx = self.tcx.tcx;
827 self.get_raw_mut(ptr.alloc_id)?.write_bytes(&tcx, ptr, src)
830 /// Expects the caller to have checked bounds and alignment.
833 src: Pointer<M::PointerTag>,
834 dest: Pointer<M::PointerTag>,
836 nonoverlapping: bool,
837 ) -> InterpResult<'tcx> {
838 self.copy_repeatedly(src, dest, size, 1, nonoverlapping)
841 /// Expects the caller to have checked bounds and alignment.
842 pub fn copy_repeatedly(
844 src: Pointer<M::PointerTag>,
845 dest: Pointer<M::PointerTag>,
848 nonoverlapping: bool,
849 ) -> InterpResult<'tcx> {
850 // first copy the relocations to a temporary buffer, because
851 // `get_bytes_mut` will clear the relocations, which is correct,
852 // since we don't want to keep any relocations at the target.
853 // (`get_bytes_with_undef_and_ptr` below checks that there are no
854 // relocations overlapping the edges; those would not be handled correctly).
855 let relocations = self.get_raw(src.alloc_id)?
856 .prepare_relocation_copy(self, src, size, dest, length);
858 let tcx = self.tcx.tcx;
860 // This checks relocation edges on the src.
861 let src_bytes = self.get_raw(src.alloc_id)?
862 .get_bytes_with_undef_and_ptr(&tcx, src, size)?
864 let dest_bytes = self.get_raw_mut(dest.alloc_id)?
865 .get_bytes_mut(&tcx, dest, size * length)?
868 // SAFE: The above indexing would have panicked if there weren't at least `size` bytes
869 // behind `src` and `dest`. Also, we use the overlapping-safe `ptr::copy` if `src` and
870 // `dest` could possibly overlap.
871 // The pointers above remain valid even if the `HashMap` table is moved around because they
872 // point into the `Vec` storing the bytes.
874 assert_eq!(size.bytes() as usize as u64, size.bytes());
875 if src.alloc_id == dest.alloc_id {
877 if (src.offset <= dest.offset && src.offset + size > dest.offset) ||
878 (dest.offset <= src.offset && dest.offset + size > src.offset)
881 "copy_nonoverlapping called on overlapping ranges"
888 dest_bytes.offset((size.bytes() * i) as isize),
889 size.bytes() as usize);
893 ptr::copy_nonoverlapping(src_bytes,
894 dest_bytes.offset((size.bytes() * i) as isize),
895 size.bytes() as usize);
900 // copy definedness to the destination
901 self.copy_undef_mask(src, dest, size, length)?;
902 // copy the relocations to the destination
903 self.get_raw_mut(dest.alloc_id)?.mark_relocation_range(relocations);
910 impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M> {
911 // FIXME: Add a fast version for the common, nonoverlapping case
914 src: Pointer<M::PointerTag>,
915 dest: Pointer<M::PointerTag>,
918 ) -> InterpResult<'tcx> {
919 // The bits have to be saved locally before writing to dest in case src and dest overlap.
920 assert_eq!(size.bytes() as usize as u64, size.bytes());
922 let src_alloc = self.get_raw(src.alloc_id)?;
923 let compressed = src_alloc.compress_undef_range(src, size);
925 // now fill in all the data
926 let dest_allocation = self.get_raw_mut(dest.alloc_id)?;
927 dest_allocation.mark_compressed_undef_range(&compressed, dest, size, repeat);
934 scalar: Scalar<M::PointerTag>,
935 ) -> InterpResult<'tcx, Pointer<M::PointerTag>> {
937 Scalar::Ptr(ptr) => Ok(ptr),
938 _ => M::int_to_ptr(&self, scalar.to_machine_usize(self)?)
944 scalar: Scalar<M::PointerTag>,
946 ) -> InterpResult<'tcx, u128> {
947 match scalar.to_bits_or_ptr(size, self) {
948 Ok(bits) => Ok(bits),
949 Err(ptr) => Ok(M::ptr_to_int(&self, ptr)? as u128)