Struct rustc_const_eval::interpret::Memory

pub struct Memory<'mir, 'tcx, M: Machine<'mir, 'tcx>> {
    pub(super) alloc_map: M::MemoryMap,
    extra_fn_ptr_map: FxHashMap<AllocId, M::ExtraFnVal>,
    pub(super) dead_alloc_map: FxHashMap<AllocId, (Size, Align)>,
    pub extra: M::MemoryExtra,
    pub tcx: TyCtxt<'tcx>,
}

Fields

alloc_map: M::MemoryMap

Allocations local to this instance of the miri engine. The kind helps ensure that the same mechanism is used for allocation and deallocation. When an allocation is not found here, it is a global and looked up in the tcx for read access. Some machines may have to mutate this map even on a read-only access to a global (because they do pointer provenance tracking and the allocations in tcx have the wrong type), so we let the machine override this type. Either way, if the machine allows writing to a global, doing so will create a copy of the global allocation here.

extra_fn_ptr_map: FxHashMap<AllocId, M::ExtraFnVal>

Map for “extra” function pointers.

dead_alloc_map: FxHashMap<AllocId, (Size, Align)>

To be able to compare pointers with null, and to check alignment for accesses to ZSTs (where pointers may dangle), we keep track of the size even for allocations that do not exist any more.

extra: M::MemoryExtra

Extra data added by the machine.

tcx: TyCtxt<'tcx>

Lets us implement HasDataLayout, which is awfully convenient.

Implementations

impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M>

pub fn new(tcx: TyCtxt<'tcx>, extra: M::MemoryExtra) -> Self

pub fn global_base_pointer(
    &self,
    ptr: Pointer<AllocId>
) -> InterpResult<'tcx, Pointer<M::PointerTag>>

Call this to turn untagged “global” pointers (obtained via tcx) into the machine pointer to the allocation. Must never be used for any other pointers, nor for TLS statics.

Using the resulting pointer represents a direct access to that memory (e.g. by directly using a static), as opposed to access through a pointer that was created by the program.

This function can fail only if ptr points to an extern static.

pub fn create_fn_alloc(
    &mut self,
    fn_val: FnVal<'tcx, M::ExtraFnVal>
) -> Pointer<M::PointerTag>

pub fn allocate(
    &mut self,
    size: Size,
    align: Align,
    kind: MemoryKind<M::MemoryKind>
) -> InterpResult<'static, Pointer<M::PointerTag>>

pub fn allocate_bytes(
    &mut self,
    bytes: &[u8],
    align: Align,
    kind: MemoryKind<M::MemoryKind>,
    mutability: Mutability
) -> Pointer<M::PointerTag>

pub fn allocate_with(
    &mut self,
    alloc: Allocation,
    kind: MemoryKind<M::MemoryKind>
) -> Pointer<M::PointerTag>

pub fn reallocate(
    &mut self,
    ptr: Pointer<Option<M::PointerTag>>,
    old_size_and_align: Option<(Size, Align)>,
    new_size: Size,
    new_align: Align,
    kind: MemoryKind<M::MemoryKind>
) -> InterpResult<'tcx, Pointer<M::PointerTag>>

pub fn deallocate(
    &mut self,
    ptr: Pointer<Option<M::PointerTag>>,
    old_size_and_align: Option<(Size, Align)>,
    kind: MemoryKind<M::MemoryKind>
) -> InterpResult<'tcx>

fn get_ptr_access(
    &self,
    ptr: Pointer<Option<M::PointerTag>>,
    size: Size,
    align: Align
) -> InterpResult<'tcx, Option<(AllocId, Size, Pointer<M::PointerTag>)>>

Internal helper function to determine the allocation and offset of a pointer (if any).

pub fn check_ptr_access_align(
    &self,
    ptr: Pointer<Option<M::PointerTag>>,
    size: Size,
    align: Align,
    msg: CheckInAllocMsg
) -> InterpResult<'tcx>

Check if the given pointer points to live memory of given size and align (ignoring M::enforce_alignment). The caller can control the error message for the out-of-bounds case.

fn check_and_deref_ptr<T>(
    &self,
    ptr: Pointer<Option<M::PointerTag>>,
    size: Size,
    align: Option<Align>,
    msg: CheckInAllocMsg,
    alloc_size: impl FnOnce(AllocId, Size, Pointer<M::PointerTag>) -> InterpResult<'tcx, (Size, Align, T)>
) -> InterpResult<'tcx, Option<T>>

Low-level helper function to check if a ptr is in-bounds and potentially return a reference to the allocation it points to. Supports both shared and mutable references, as the actual checking is offloaded to a helper closure. align defines whether and which alignment check is done. Returns None for size 0, and otherwise Some of what alloc_size returned.

pub fn ptr_may_be_null(&self, ptr: Pointer<Option<M::PointerTag>>) -> bool

Test if the pointer might be null.

impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M>

Allocation accessors

fn get_global_alloc(
    &self,
    id: AllocId,
    is_write: bool
) -> InterpResult<'tcx, Cow<'tcx, Allocation<M::PointerTag, M::AllocExtra>>>

Helper function to obtain a global (tcx) allocation. This attempts to return a reference to an existing allocation if one can be found in tcx. That, however, is only possible if tcx and this machine use the same pointer tag, so it is indirected through M::tag_allocation.

fn get_raw(
    &self,
    id: AllocId
) -> InterpResult<'tcx, &Allocation<M::PointerTag, M::AllocExtra>>

Gives raw access to the Allocation, without bounds or alignment checks. The caller is responsible for calling the access hooks!

pub fn get<'a>(
    &'a self,
    ptr: Pointer<Option<M::PointerTag>>,
    size: Size,
    align: Align
) -> InterpResult<'tcx, Option<AllocRef<'a, 'tcx, M::PointerTag, M::AllocExtra>>>

“Safe” (bounds and align-checked) allocation access.

pub fn get_alloc_extra<'a>(
    &'a self,
    id: AllocId
) -> InterpResult<'tcx, &'a M::AllocExtra>

Return the extra field of the given allocation.

fn get_raw_mut(
    &mut self,
    id: AllocId
) -> InterpResult<'tcx, (&mut Allocation<M::PointerTag, M::AllocExtra>, &mut M::MemoryExtra)>

Gives raw mutable access to the Allocation, without bounds or alignment checks. The caller is responsible for calling the access hooks!

Also returns a ptr to self.extra so that the caller can use it in parallel with the allocation.

pub fn get_mut<'a>(
    &'a mut self,
    ptr: Pointer<Option<M::PointerTag>>,
    size: Size,
    align: Align
) -> InterpResult<'tcx, Option<AllocRefMut<'a, 'tcx, M::PointerTag, M::AllocExtra>>>

“Safe” (bounds and align-checked) allocation access.

pub fn get_alloc_extra_mut<'a>(
    &'a mut self,
    id: AllocId
) -> InterpResult<'tcx, (&'a mut M::AllocExtra, &'a mut M::MemoryExtra)>

Return the extra field of the given allocation.

pub fn get_size_and_align(
    &self,
    id: AllocId,
    liveness: AllocCheck
) -> InterpResult<'static, (Size, Align)>

Obtain the size and alignment of an allocation, even if that allocation has been deallocated.

If liveness is AllocCheck::MaybeDead, this function always returns Ok.

fn get_fn_alloc(&self, id: AllocId) -> Option<FnVal<'tcx, M::ExtraFnVal>>

pub fn get_fn(
    &self,
    ptr: Pointer<Option<M::PointerTag>>
) -> InterpResult<'tcx, FnVal<'tcx, M::ExtraFnVal>>

pub fn mark_immutable(&mut self, id: AllocId) -> InterpResult<'tcx>

pub fn dump_alloc<'a>(&'a self, id: AllocId) -> DumpAllocs<'a, 'mir, 'tcx, M>

Create a lazy debug printer that prints the given allocation and all allocations it points to, recursively.

pub fn dump_allocs<'a>(
    &'a self,
    allocs: Vec<AllocId>
) -> DumpAllocs<'a, 'mir, 'tcx, M>

Create a lazy debug printer for a list of allocations and all allocations they point to, recursively.

pub fn leak_report(&self, static_roots: &[AllocId]) -> usize

Print leaked memory. Allocations reachable from static_roots or a Global allocation are not considered leaked. Leaks whose kind may_leak() returns true are not reported.

pub fn alloc_map(&self) -> &M::MemoryMap

This is used by priroda

impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M>

pub fn read_bytes(
    &self,
    ptr: Pointer<Option<M::PointerTag>>,
    size: Size
) -> InterpResult<'tcx, &[u8]>

Reads the given number of bytes from memory. Returns them as a slice.

Performs appropriate bounds checks.

pub fn write_bytes(
    &mut self,
    ptr: Pointer<Option<M::PointerTag>>,
    src: impl IntoIterator<Item = u8>
) -> InterpResult<'tcx>

Writes the given stream of bytes into memory.

Performs appropriate bounds checks.

pub fn copy(
    &mut self,
    src: Pointer<Option<M::PointerTag>>,
    src_align: Align,
    dest: Pointer<Option<M::PointerTag>>,
    dest_align: Align,
    size: Size,
    nonoverlapping: bool
) -> InterpResult<'tcx>

pub fn copy_repeatedly(
    &mut self,
    src: Pointer<Option<M::PointerTag>>,
    src_align: Align,
    dest: Pointer<Option<M::PointerTag>>,
    dest_align: Align,
    size: Size,
    num_copies: u64,
    nonoverlapping: bool
) -> InterpResult<'tcx>

impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> Memory<'mir, 'tcx, M>

Machine pointer introspection.

pub fn scalar_to_ptr(
    &self,
    scalar: Scalar<M::PointerTag>
) -> Pointer<Option<M::PointerTag>>

pub fn ptr_try_get_alloc(
    &self,
    ptr: Pointer<Option<M::PointerTag>>
) -> Result<(AllocId, Size, Pointer<M::PointerTag>), u64>

Turning a “maybe pointer” into a proper pointer (and some information about where it points), or an absolute address.

pub fn ptr_get_alloc(
    &self,
    ptr: Pointer<Option<M::PointerTag>>
) -> InterpResult<'tcx, (AllocId, Size, Pointer<M::PointerTag>)>

Turning a “maybe pointer” into a proper pointer (and some information about where it points).

Trait Implementations

impl<'mir, 'tcx, M: Machine<'mir, 'tcx>> HasDataLayout for Memory<'mir, 'tcx, M>

fn data_layout(&self) -> &TargetDataLayout

Layout

Note: Unable to compute type layout, possibly due to this type having generic parameters. Layout can only be computed for concrete, fully-instantiated types.