diff options
Diffstat (limited to 'compiler/rustc_middle')
| -rw-r--r-- | compiler/rustc_middle/src/mir/interpret/allocation.rs | 194 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs | 274 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/mir/interpret/mod.rs | 4 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/mir/interpret/pointer.rs | 25 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/mir/pretty.rs | 22 | ||||
| -rw-r--r-- | compiler/rustc_middle/src/ty/impls_ty.rs | 13 |
6 files changed, 328 insertions, 204 deletions
diff --git a/compiler/rustc_middle/src/mir/interpret/allocation.rs b/compiler/rustc_middle/src/mir/interpret/allocation.rs index 37ec04b07f8..ba64711ea28 100644 --- a/compiler/rustc_middle/src/mir/interpret/allocation.rs +++ b/compiler/rustc_middle/src/mir/interpret/allocation.rs @@ -1,16 +1,17 @@ //! The virtual memory representation of the MIR interpreter. +mod provenance_map; + use std::borrow::Cow; use std::convert::{TryFrom, TryInto}; use std::fmt; use std::hash; use std::iter; -use std::ops::{Deref, Range}; +use std::ops::Range; use std::ptr; use rustc_ast::Mutability; use rustc_data_structures::intern::Interned; -use rustc_data_structures::sorted_map::SortedMap; use rustc_span::DUMMY_SP; use rustc_target::abi::{Align, HasDataLayout, Size}; @@ -20,6 +21,7 @@ use super::{ UnsupportedOpInfo, }; use crate::ty; +use provenance_map::*; /// This type represents an Allocation in the Miri/CTFE core engine. /// @@ -271,10 +273,10 @@ impl Allocation { ) -> Result<Allocation<Prov, Extra>, Err> { // Compute new pointer provenance, which also adjusts the bytes. let mut bytes = self.bytes; - let mut new_provenance = Vec::with_capacity(self.provenance.0.len()); + let mut new_provenance = Vec::with_capacity(self.provenance.ptrs().len()); let ptr_size = cx.data_layout().pointer_size.bytes_usize(); let endian = cx.data_layout().endian; - for &(offset, alloc_id) in self.provenance.iter() { + for &(offset, alloc_id) in self.provenance.ptrs().iter() { let idx = offset.bytes_usize(); let ptr_bytes = &mut bytes[idx..idx + ptr_size]; let bits = read_target_uint(endian, ptr_bytes).unwrap(); @@ -286,7 +288,7 @@ impl Allocation { // Create allocation. Ok(Allocation { bytes, - provenance: ProvenanceMap::from_presorted(new_provenance), + provenance: ProvenanceMap::from_presorted_ptrs(new_provenance), init_mask: self.init_mask, align: self.align, mutability: self.mutability, @@ -351,7 +353,7 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { ) -> AllocResult<&[u8]> { self.check_init(range)?; if !Prov::OFFSET_IS_ADDR { - if self.range_has_provenance(cx, range) { + if !self.provenance.range_empty(range, cx) { return Err(AllocError::ReadPointerAsBytes); } } @@ -370,7 +372,7 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { range: AllocRange, ) -> AllocResult<&mut [u8]> { self.mark_init(range, true); - self.clear_provenance(cx, range)?; + self.provenance.clear(range, cx)?; Ok(&mut self.bytes[range.start.bytes_usize()..range.end().bytes_usize()]) } @@ -382,7 +384,7 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { range: AllocRange, ) -> AllocResult<*mut [u8]> { self.mark_init(range, true); - self.clear_provenance(cx, range)?; + self.provenance.clear(range, cx)?; assert!(range.end().bytes_usize() <= self.bytes.len()); // need to do our own bounds-check let begin_ptr = self.bytes.as_mut_ptr().wrapping_add(range.start.bytes_usize()); @@ -423,7 +425,7 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { // When reading data with provenance, the easy case is finding provenance exactly where we // are reading, then we can put data and provenance back together and return that. - if let Some(&prov) = self.provenance.get(&range.start) { + if let Some(prov) = self.provenance.get_ptr(range.start) { // Now we can return the bits, with their appropriate provenance. let ptr = Pointer::new(prov, Size::from_bytes(bits)); return Ok(Scalar::from_pointer(ptr, cx)); @@ -431,10 +433,9 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { // If we can work on pointers byte-wise, join the byte-wise provenances. if Prov::OFFSET_IS_ADDR { - let mut prov = self.offset_get_provenance(cx, range.start); - for offset in 1..range.size.bytes() { - let this_prov = - self.offset_get_provenance(cx, range.start + Size::from_bytes(offset)); + let mut prov = self.provenance.get(range.start, cx); + for offset in Size::from_bytes(1)..range.size { + let this_prov = self.provenance.get(range.start + offset, cx); prov = Prov::join(prov, this_prov); } // Now use this provenance. @@ -452,7 +453,7 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { // Fallback path for when we cannot treat provenance bytewise or ignore it. assert!(!Prov::OFFSET_IS_ADDR); - if self.range_has_provenance(cx, range) { + if !self.provenance.range_empty(range, cx) { return Err(AllocError::ReadPointerAsBytes); } // There is no provenance, we can just return the bits. @@ -466,7 +467,6 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { /// /// It is the caller's responsibility to check bounds and alignment beforehand. /// Most likely, you want to call `InterpCx::write_scalar` instead of this method. - #[instrument(skip(self, cx), level = "debug")] pub fn write_scalar( &mut self, cx: &impl HasDataLayout, @@ -491,7 +491,8 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { // See if we have to also store some provenance. if let Some(provenance) = provenance { - self.provenance.0.insert(range.start, provenance); + assert_eq!(range.size, cx.data_layout().pointer_size); + self.provenance.insert_ptr(range.start, provenance, cx); } Ok(()) @@ -500,171 +501,18 @@ impl<Prov: Provenance, Extra> Allocation<Prov, Extra> { /// Write "uninit" to the given memory range. pub fn write_uninit(&mut self, cx: &impl HasDataLayout, range: AllocRange) -> AllocResult { self.mark_init(range, false); - self.clear_provenance(cx, range)?; + self.provenance.clear(range, cx)?; return Ok(()); } -} - -/// Provenance. -impl<Prov: Copy, Extra> Allocation<Prov, Extra> { - /// Returns all provenance overlapping with the given pointer-offset pair. - fn range_get_provenance(&self, cx: &impl HasDataLayout, range: AllocRange) -> &[(Size, Prov)] { - // We have to go back `pointer_size - 1` bytes, as that one would still overlap with - // the beginning of this range. - let start = range.start.bytes().saturating_sub(cx.data_layout().pointer_size.bytes() - 1); - self.provenance.range(Size::from_bytes(start)..range.end()) - } - - /// Get the provenance of a single byte. - fn offset_get_provenance(&self, cx: &impl HasDataLayout, offset: Size) -> Option<Prov> { - let prov = self.range_get_provenance(cx, alloc_range(offset, Size::from_bytes(1))); - assert!(prov.len() <= 1); - prov.first().map(|(_offset, prov)| *prov) - } - - /// Returns whether this allocation has progrnance overlapping with the given range. - /// - /// Note: this function exists to allow `range_get_provenance` to be private, in order to somewhat - /// limit access to provenance outside of the `Allocation` abstraction. - /// - pub fn range_has_provenance(&self, cx: &impl HasDataLayout, range: AllocRange) -> bool { - !self.range_get_provenance(cx, range).is_empty() - } - - /// Removes all provenance inside the given range. - /// If there is provenance overlapping with the edges, it - /// are removed as well *and* the bytes they cover are marked as - /// uninitialized. This is a somewhat odd "spooky action at a distance", - /// but it allows strictly more code to run than if we would just error - /// immediately in that case. - fn clear_provenance(&mut self, cx: &impl HasDataLayout, range: AllocRange) -> AllocResult - where - Prov: Provenance, - { - // Find the start and end of the given range and its outermost provenance. - let (first, last) = { - // Find all provenance overlapping the given range. - let provenance = self.range_get_provenance(cx, range); - if provenance.is_empty() { - return Ok(()); - } - - ( - provenance.first().unwrap().0, - provenance.last().unwrap().0 + cx.data_layout().pointer_size, - ) - }; - let start = range.start; - let end = range.end(); - - // We need to handle clearing the provenance from parts of a pointer. - // FIXME: Miri should preserve partial provenance; see - // https://github.com/rust-lang/miri/issues/2181. - if first < start { - if Prov::ERR_ON_PARTIAL_PTR_OVERWRITE { - return Err(AllocError::PartialPointerOverwrite(first)); - } - warn!( - "Partial pointer overwrite! De-initializing memory at offsets {first:?}..{start:?}." - ); - self.init_mask.set_range(first, start, false); - } - if last > end { - if Prov::ERR_ON_PARTIAL_PTR_OVERWRITE { - return Err(AllocError::PartialPointerOverwrite( - last - cx.data_layout().pointer_size, - )); - } - warn!( - "Partial pointer overwrite! De-initializing memory at offsets {end:?}..{last:?}." - ); - self.init_mask.set_range(end, last, false); - } - - // Forget all the provenance. - // Since provenance do not overlap, we know that removing until `last` (exclusive) is fine, - // i.e., this will not remove any other provenance just after the ones we care about. - self.provenance.0.remove_range(first..last); - - Ok(()) - } -} - -/// Stores the provenance information of pointers stored in memory. -#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)] -pub struct ProvenanceMap<Prov = AllocId>(SortedMap<Size, Prov>); - -impl<Prov> ProvenanceMap<Prov> { - pub fn new() -> Self { - ProvenanceMap(SortedMap::new()) - } - - // The caller must guarantee that the given provenance list is already sorted - // by address and contain no duplicates. - pub fn from_presorted(r: Vec<(Size, Prov)>) -> Self { - ProvenanceMap(SortedMap::from_presorted_elements(r)) - } -} - -impl<Prov> Deref for ProvenanceMap<Prov> { - type Target = SortedMap<Size, Prov>; - - fn deref(&self) -> &Self::Target { - &self.0 - } -} - -/// A partial, owned list of provenance to transfer into another allocation. -/// -/// Offsets are already adjusted to the destination allocation. -pub struct AllocationProvenance<Prov> { - dest_provenance: Vec<(Size, Prov)>, -} - -impl<Prov: Copy, Extra> Allocation<Prov, Extra> { - pub fn prepare_provenance_copy( - &self, - cx: &impl HasDataLayout, - src: AllocRange, - dest: Size, - count: u64, - ) -> AllocationProvenance<Prov> { - let provenance = self.range_get_provenance(cx, src); - if provenance.is_empty() { - return AllocationProvenance { dest_provenance: Vec::new() }; - } - - let size = src.size; - let mut new_provenance = Vec::with_capacity(provenance.len() * (count as usize)); - - // If `count` is large, this is rather wasteful -- we are allocating a big array here, which - // is mostly filled with redundant information since it's just N copies of the same `Prov`s - // at slightly adjusted offsets. The reason we do this is so that in `mark_provenance_range` - // we can use `insert_presorted`. That wouldn't work with an `Iterator` that just produces - // the right sequence of provenance for all N copies. - for i in 0..count { - new_provenance.extend(provenance.iter().map(|&(offset, reloc)| { - // compute offset for current repetition - let dest_offset = dest + size * i; // `Size` operations - ( - // shift offsets from source allocation to destination allocation - (offset + dest_offset) - src.start, // `Size` operations - reloc, - ) - })); - } - - AllocationProvenance { dest_provenance: new_provenance } - } /// Applies a provenance copy. - /// The affected range, as defined in the parameters to `prepare_provenance_copy` is expected + /// The affected range, as defined in the parameters to `provenance().prepare_copy` is expected /// to be clear of provenance. /// /// This is dangerous to use as it can violate internal `Allocation` invariants! /// It only exists to support an efficient implementation of `mem_copy_repeatedly`. - pub fn mark_provenance_range(&mut self, provenance: AllocationProvenance<Prov>) { - self.provenance.0.insert_presorted(provenance.dest_provenance); + pub fn provenance_apply_copy(&mut self, copy: ProvenanceCopy<Prov>) { + self.provenance.apply_copy(copy) } } diff --git a/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs b/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs new file mode 100644 index 00000000000..f0f990f4e9d --- /dev/null +++ b/compiler/rustc_middle/src/mir/interpret/allocation/provenance_map.rs @@ -0,0 +1,274 @@ +//! Store the provenance for each byte in the range, with a more efficient +//! representation for the common case where PTR_SIZE consecutive bytes have the same provenance. + +use std::cmp; + +use rustc_data_structures::sorted_map::SortedMap; +use rustc_target::abi::{HasDataLayout, Size}; + +use super::{alloc_range, AllocError, AllocId, AllocRange, AllocResult, Provenance}; + +/// Stores the provenance information of pointers stored in memory. +#[derive(Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Debug, TyEncodable, TyDecodable)] +#[derive(HashStable)] +pub struct ProvenanceMap<Prov = AllocId> { + /// Provenance in this map applies from the given offset for an entire pointer-size worth of + /// bytes. Two entires in this map are always at least a pointer size apart. + ptrs: SortedMap<Size, Prov>, + /// Provenance in this map only applies to the given single byte. + /// This map is disjoint from the previous. + bytes: SortedMap<Size, Prov>, +} + +impl<Prov> ProvenanceMap<Prov> { + pub fn new() -> Self { + ProvenanceMap { ptrs: SortedMap::new(), bytes: SortedMap::new() } + } + + /// The caller must guarantee that the given provenance list is already sorted + /// by address and contain no duplicates. + pub fn from_presorted_ptrs(r: Vec<(Size, Prov)>) -> Self { + ProvenanceMap { ptrs: SortedMap::from_presorted_elements(r), bytes: SortedMap::new() } + } +} + +impl ProvenanceMap { + /// Give access to the ptr-sized provenances (which can also be thought of as relocations, and + /// indeed that is how codegen treats them). + /// + /// Only exposed with `AllocId` provenance, since it panics if there is bytewise provenance. + pub fn ptrs(&self) -> &SortedMap<Size, AllocId> { + assert!(self.bytes.is_empty()); + &self.ptrs + } +} + +impl<Prov: Provenance> ProvenanceMap<Prov> { + /// Returns all ptr-sized provenance in the given range. + /// If the range has length 0, returns provenance that crosses the edge between `start-1` and + /// `start`. + fn range_get_ptrs(&self, range: AllocRange, cx: &impl HasDataLayout) -> &[(Size, Prov)] { + // We have to go back `pointer_size - 1` bytes, as that one would still overlap with + // the beginning of this range. + let adjusted_start = Size::from_bytes( + range.start.bytes().saturating_sub(cx.data_layout().pointer_size.bytes() - 1), + ); + self.ptrs.range(adjusted_start..range.end()) + } + + /// Returns all byte-wise provenance in the given range. + fn range_get_bytes(&self, range: AllocRange) -> &[(Size, Prov)] { + self.bytes.range(range.start..range.end()) + } + + /// Get the provenance of a single byte. + pub fn get(&self, offset: Size, cx: &impl HasDataLayout) -> Option<Prov> { + let prov = self.range_get_ptrs(alloc_range(offset, Size::from_bytes(1)), cx); + debug_assert!(prov.len() <= 1); + if let Some(entry) = prov.first() { + // If it overlaps with this byte, it is on this byte. + debug_assert!(self.bytes.get(&offset).is_none()); + Some(entry.1) + } else { + // Look up per-byte provenance. + self.bytes.get(&offset).copied() + } + } + + /// Check if here is ptr-sized provenance at the given index. + /// Does not mean anything for bytewise provenance! But can be useful as an optimization. + pub fn get_ptr(&self, offset: Size) -> Option<Prov> { + self.ptrs.get(&offset).copied() + } + + /// Returns whether this allocation has provenance overlapping with the given range. + /// + /// Note: this function exists to allow `range_get_provenance` to be private, in order to somewhat + /// limit access to provenance outside of the `Allocation` abstraction. + /// + pub fn range_empty(&self, range: AllocRange, cx: &impl HasDataLayout) -> bool { + self.range_get_ptrs(range, cx).is_empty() && self.range_get_bytes(range).is_empty() + } + + /// Yields all the provenances stored in this map. + pub fn provenances(&self) -> impl Iterator<Item = Prov> + '_ { + self.ptrs.values().chain(self.bytes.values()).copied() + } + + pub fn insert_ptr(&mut self, offset: Size, prov: Prov, cx: &impl HasDataLayout) { + debug_assert!(self.range_empty(alloc_range(offset, cx.data_layout().pointer_size), cx)); + self.ptrs.insert(offset, prov); + } + + /// Removes all provenance inside the given range. + /// If there is provenance overlapping with the edges, might result in an error. + pub fn clear(&mut self, range: AllocRange, cx: &impl HasDataLayout) -> AllocResult { + let start = range.start; + let end = range.end(); + // Clear the bytewise part -- this is easy. + self.bytes.remove_range(start..end); + + // For the ptr-sized part, find the first (inclusive) and last (exclusive) byte of + // provenance that overlaps with the given range. + let (first, last) = { + // Find all provenance overlapping the given range. + let provenance = self.range_get_ptrs(range, cx); + if provenance.is_empty() { + // No provenance in this range, we are done. + return Ok(()); + } + + ( + provenance.first().unwrap().0, + provenance.last().unwrap().0 + cx.data_layout().pointer_size, + ) + }; + + // We need to handle clearing the provenance from parts of a pointer. + if first < start { + if !Prov::OFFSET_IS_ADDR { + // We can't split up the provenance into less than a pointer. + return Err(AllocError::PartialPointerOverwrite(first)); + } + // Insert the remaining part in the bytewise provenance. + let prov = self.ptrs[&first]; + for offset in first..start { + self.bytes.insert(offset, prov); + } + } + if last > end { + let begin_of_last = last - cx.data_layout().pointer_size; + if !Prov::OFFSET_IS_ADDR { + // We can't split up the provenance into less than a pointer. + return Err(AllocError::PartialPointerOverwrite(begin_of_last)); + } + // Insert the remaining part in the bytewise provenance. + let prov = self.ptrs[&begin_of_last]; + for offset in end..last { + self.bytes.insert(offset, prov); + } + } + + // Forget all the provenance. + // Since provenance do not overlap, we know that removing until `last` (exclusive) is fine, + // i.e., this will not remove any other provenance just after the ones we care about. + self.ptrs.remove_range(first..last); + + Ok(()) + } +} + +/// A partial, owned list of provenance to transfer into another allocation. +/// +/// Offsets are already adjusted to the destination allocation. +pub struct ProvenanceCopy<Prov> { + dest_ptrs: Vec<(Size, Prov)>, + dest_bytes: Vec<(Size, Prov)>, +} + +impl<Prov: Provenance> ProvenanceMap<Prov> { + #[instrument(skip(self, cx), level = "debug")] + pub fn prepare_copy( + &self, + src: AllocRange, + dest: Size, + count: u64, + cx: &impl HasDataLayout, + ) -> AllocResult<ProvenanceCopy<Prov>> { + let shift_offset = move |idx, offset| { + // compute offset for current repetition + let dest_offset = dest + src.size * idx; // `Size` operations + // shift offsets from source allocation to destination allocation + (offset - src.start) + dest_offset // `Size` operations + }; + let ptr_size = cx.data_layout().pointer_size; + + // # Pointer-sized provenances + // Get the provenances that are entirely within this range. + // (Different from `range_get_ptrs` which asks if they overlap the range.) + let ptrs = if src.size < ptr_size { + // This isn't even large enough to contain a pointer. + &[] + } else { + let adjusted_end = + Size::from_bytes(src.end().bytes().saturating_sub(ptr_size.bytes() - 1)); + self.ptrs.range(src.start..adjusted_end) + }; + + // Buffer for the new list. + let mut dest_ptrs = Vec::with_capacity(ptrs.len() * (count as usize)); + // If `count` is large, this is rather wasteful -- we are allocating a big array here, which + // is mostly filled with redundant information since it's just N copies of the same `Prov`s + // at slightly adjusted offsets. The reason we do this is so that in `mark_provenance_range` + // we can use `insert_presorted`. That wouldn't work with an `Iterator` that just produces + // the right sequence of provenance for all N copies. + // Basically, this large array would have to be created anyway in the target allocation. + for i in 0..count { + dest_ptrs.extend(ptrs.iter().map(|&(offset, reloc)| (shift_offset(i, offset), reloc))); + } + + // # Byte-sized provenances + let mut bytes = Vec::new(); + // First, if there is a part of a pointer at the start, add that. + if let Some(entry) = self.range_get_ptrs(alloc_range(src.start, Size::ZERO), cx).first() { + if !Prov::OFFSET_IS_ADDR { + // We can't split up the provenance into less than a pointer. + return Err(AllocError::PartialPointerCopy(entry.0)); + } + trace!("start overlapping entry: {entry:?}"); + // For really small copies, make sure we don't run off the end of the `src` range. + let entry_end = cmp::min(entry.0 + ptr_size, src.end()); + for offset in src.start..entry_end { + bytes.push((offset, entry.1)); + } + } else { + trace!("no start overlapping entry"); + } + // Then the main part, bytewise provenance from `self.bytes`. + bytes.extend(self.bytes.range(src.start..src.end())); + // And finally possibly parts of a pointer at the end. + if let Some(entry) = self.range_get_ptrs(alloc_range(src.end(), Size::ZERO), cx).first() { + if !Prov::OFFSET_IS_ADDR { + // We can't split up the provenance into less than a pointer. + return Err(AllocError::PartialPointerCopy(entry.0)); + } + trace!("end overlapping entry: {entry:?}"); + // For really small copies, make sure we don't start before `src` does. + let entry_start = cmp::max(entry.0, src.start); + for offset in entry_start..src.end() { + if bytes.last().map_or(true, |bytes_entry| bytes_entry.0 < offset) { + // The last entry, if it exists, has a lower offset than us. + bytes.push((offset, entry.1)); + } else { + // There already is an entry for this offset in there! This can happen when the + // start and end range checks actually end up hitting the same pointer, so we + // already added this in the "pointer at the start" part above. + assert!(entry.0 <= src.start); + } + } + } else { + trace!("no end overlapping entry"); + } + trace!("byte provenances: {bytes:?}"); + + // And again a buffer for the new list on the target side. + let mut dest_bytes = Vec::with_capacity(bytes.len() * (count as usize)); + for i in 0..count { + dest_bytes + .extend(bytes.iter().map(|&(offset, reloc)| (shift_offset(i, offset), reloc))); + } + + Ok(ProvenanceCopy { dest_ptrs, dest_bytes }) + } + + /// Applies a provenance copy. + /// The affected range, as defined in the parameters to `prepare_copy` is expected + /// to be clear of provenance. + /// + /// This is dangerous to use as it can violate internal `Allocation` invariants! + /// It only exists to support an efficient implementation of `mem_copy_repeatedly`. + pub fn apply_copy(&mut self, copy: ProvenanceCopy<Prov>) { + self.ptrs.insert_presorted(copy.dest_ptrs); + self.bytes.insert_presorted(copy.dest_bytes); + } +} diff --git a/compiler/rustc_middle/src/mir/interpret/mod.rs b/compiler/rustc_middle/src/mir/interpret/mod.rs index 5e3dfcbcc49..9c8ab44cfd6 100644 --- a/compiler/rustc_middle/src/mir/interpret/mod.rs +++ b/compiler/rustc_middle/src/mir/interpret/mod.rs @@ -127,8 +127,8 @@ pub use self::error::{ pub use self::value::{get_slice_bytes, ConstAlloc, ConstValue, Scalar}; pub use self::allocation::{ - alloc_range, AllocRange, Allocation, ConstAllocation, InitChunk, InitChunkIter, InitMask, - ProvenanceMap, + alloc_range, AllocError, AllocRange, AllocResult, Allocation, ConstAllocation, InitChunk, + InitChunkIter, InitMask, }; pub use self::pointer::{Pointer, PointerArithmetic, Provenance}; diff --git a/compiler/rustc_middle/src/mir/interpret/pointer.rs b/compiler/rustc_middle/src/mir/interpret/pointer.rs index 23c2ce6474c..4e59f1b2482 100644 --- a/compiler/rustc_middle/src/mir/interpret/pointer.rs +++ b/compiler/rustc_middle/src/mir/interpret/pointer.rs @@ -103,8 +103,7 @@ impl<T: HasDataLayout> PointerArithmetic for T {} /// This trait abstracts over the kind of provenance that is associated with a `Pointer`. It is /// mostly opaque; the `Machine` trait extends it with some more operations that also have access to /// some global state. -/// We don't actually care about this `Debug` bound (we use `Provenance::fmt` to format the entire -/// pointer), but `derive` adds some unnecessary bounds. +/// The `Debug` rendering is used to distplay bare provenance, and for the default impl of `fmt`. pub trait Provenance: Copy + fmt::Debug { /// Says whether the `offset` field of `Pointer`s with this provenance is the actual physical address. /// - If `false`, the offset *must* be relative. This means the bytes representing a pointer are @@ -115,14 +114,23 @@ pub trait Provenance: Copy + fmt::Debug { /// pointer, and implement ptr-to-int transmutation by stripping provenance. const OFFSET_IS_ADDR: bool; - /// We also use this trait to control whether to abort execution when a pointer is being partially overwritten - /// (this avoids a separate trait in `allocation.rs` just for this purpose). - const ERR_ON_PARTIAL_PTR_OVERWRITE: bool; - /// Determines how a pointer should be printed. + /// + /// Default impl is only good for when `OFFSET_IS_ADDR == true`. fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result where - Self: Sized; + Self: Sized, + { + assert!(Self::OFFSET_IS_ADDR); + let (prov, addr) = ptr.into_parts(); // address is absolute + write!(f, "{:#x}", addr.bytes())?; + if f.alternate() { + write!(f, "{prov:#?}")?; + } else { + write!(f, "{prov:?}")?; + } + Ok(()) + } /// If `OFFSET_IS_ADDR == false`, provenance must always be able to /// identify the allocation this ptr points to (i.e., this must return `Some`). @@ -139,9 +147,6 @@ impl Provenance for AllocId { // so ptr-to-int casts are not possible (since we do not know the global physical offset). const OFFSET_IS_ADDR: bool = false; - // For now, do not allow this, so that we keep our options open. - const ERR_ON_PARTIAL_PTR_OVERWRITE: bool = true; - fn fmt(ptr: &Pointer<Self>, f: &mut fmt::Formatter<'_>) -> fmt::Result { // Forward `alternate` flag to `alloc_id` printing. if f.alternate() { diff --git a/compiler/rustc_middle/src/mir/pretty.rs b/compiler/rustc_middle/src/mir/pretty.rs index 05dcfba77b2..7965a9499a1 100644 --- a/compiler/rustc_middle/src/mir/pretty.rs +++ b/compiler/rustc_middle/src/mir/pretty.rs @@ -685,7 +685,7 @@ pub fn write_allocations<'tcx>( fn alloc_ids_from_alloc( alloc: ConstAllocation<'_>, ) -> impl DoubleEndedIterator<Item = AllocId> + '_ { - alloc.inner().provenance().values().map(|id| *id) + alloc.inner().provenance().ptrs().values().map(|id| *id) } fn alloc_ids_from_const_val(val: ConstValue<'_>) -> impl Iterator<Item = AllocId> + '_ { @@ -882,7 +882,7 @@ fn write_allocation_bytes<'tcx, Prov: Provenance, Extra>( if i != line_start { write!(w, " ")?; } - if let Some(&prov) = alloc.provenance().get(&i) { + if let Some(prov) = alloc.provenance().get_ptr(i) { // Memory with provenance must be defined assert!(alloc.init_mask().is_range_initialized(i, i + ptr_size).is_ok()); let j = i.bytes_usize(); @@ -904,9 +904,9 @@ fn write_allocation_bytes<'tcx, Prov: Provenance, Extra>( let overflow = ptr_size - remainder; let remainder_width = provenance_width(remainder.bytes_usize()) - 2; let overflow_width = provenance_width(overflow.bytes_usize() - 1) + 1; - ascii.push('╾'); - for _ in 0..remainder.bytes() - 1 { - ascii.push('─'); + ascii.push('╾'); // HEAVY LEFT AND LIGHT RIGHT + for _ in 1..remainder.bytes() { + ascii.push('─'); // LIGHT HORIZONTAL } if overflow_width > remainder_width && overflow_width >= target.len() { // The case where the provenance fits into the part in the next line @@ -926,7 +926,7 @@ fn write_allocation_bytes<'tcx, Prov: Provenance, Extra>( for _ in 0..overflow.bytes() - 1 { ascii.push('─'); } - ascii.push('╼'); + ascii.push('╼'); // LIGHT LEFT AND HEAVY RIGHT i += ptr_size; continue; } else { @@ -941,6 +941,16 @@ fn write_allocation_bytes<'tcx, Prov: Provenance, Extra>( ascii.push('╼'); i += ptr_size; } + } else if let Some(prov) = alloc.provenance().get(i, &tcx) { + // Memory with provenance must be defined + assert!(alloc.init_mask().is_range_initialized(i, i + Size::from_bytes(1)).is_ok()); + ascii.push('━'); // HEAVY HORIZONTAL + // We have two characters to display this, which is obviously not enough. + // Format is similar to "oversized" above. + let j = i.bytes_usize(); + let c = alloc.inspect_with_uninit_and_ptr_outside_interpreter(j..j + 1)[0]; + write!(w, "╾{:02x}{:#?} (1 ptr byte)╼", c, prov)?; + i += Size::from_bytes(1); } else if alloc.init_mask().is_range_initialized(i, i + Size::from_bytes(1)).is_ok() { let j = i.bytes_usize(); diff --git a/compiler/rustc_middle/src/ty/impls_ty.rs b/compiler/rustc_middle/src/ty/impls_ty.rs index d1c0d62ac6e..3e59c0b967c 100644 --- a/compiler/rustc_middle/src/ty/impls_ty.rs +++ b/compiler/rustc_middle/src/ty/impls_ty.rs @@ -112,19 +112,6 @@ impl<'a> HashStable<StableHashingContext<'a>> for mir::interpret::AllocId { } } -// `Relocations` with default type parameters is a sorted map. -impl<'a, Prov> HashStable<StableHashingContext<'a>> for mir::interpret::ProvenanceMap<Prov> -where - Prov: HashStable<StableHashingContext<'a>>, -{ - fn hash_stable(&self, hcx: &mut StableHashingContext<'a>, hasher: &mut StableHasher) { - self.len().hash_stable(hcx, hasher); - for reloc in self.iter() { - reloc.hash_stable(hcx, hasher); - } - } -} - impl<'a> ToStableHashKey<StableHashingContext<'a>> for region::Scope { type KeyType = region::Scope; |