Struct rustc_mir::interpret::intern::InternVisitor

struct InternVisitor<'rt, 'mir, 'tcx, M: CompileTimeMachine<'mir, 'tcx, MemoryKind>> {
    ecx: &'rt mut InterpCx<'mir, 'tcx, M>,
    ref_tracking: &'rt mut RefTracking<(MPlaceTy<'tcx>, InternMode)>,
    leftover_allocations: &'rt mut FxHashSet<AllocId>,
    mode: InternMode,
    inside_unsafe_cell: bool,
}

Fields

ecx: &'rt mut InterpCx<'mir, 'tcx, M>

The ectx from which we intern.

ref_tracking: &'rt mut RefTracking<(MPlaceTy<'tcx>, InternMode)>

Previously encountered safe references.

leftover_allocations: &'rt mut FxHashSet<AllocId>

A list of all encountered allocations. After type-based interning, we traverse this list to also intern allocations that are only referenced by a raw pointer or inside a union.

mode: InternMode

The root kind of the value that we’re looking at. This field is never mutated for a particular allocation. It is primarily used to make as many allocations as possible read-only so LLVM can place them in const memory.

inside_unsafe_cell: bool

This field stores whether we are currently inside an UnsafeCell. This can affect the intern mode of references we encounter.

Implementations

impl<'rt, 'mir, 'tcx, M: CompileTimeMachine<'mir, 'tcx, MemoryKind>> InternVisitor<'rt, 'mir, 'tcx, M>

fn intern_shallow(
    &mut self,
    alloc_id: AllocId,
    mode: InternMode,
    ty: Option<Ty<'tcx>>
) -> Option<IsStaticOrFn>

Trait Implementations

impl<'rt, 'mir, 'tcx: 'mir, M: CompileTimeMachine<'mir, 'tcx, MemoryKind>> ValueVisitor<'mir, 'tcx, M> for InternVisitor<'rt, 'mir, 'tcx, M>

type V = MPlaceTy<'tcx>

fn ecx(&self) -> &InterpCx<'mir, 'tcx, M>

The visitor must have an InterpCx in it.

fn visit_aggregate(
    &mut self,
    mplace: &MPlaceTy<'tcx>,
    fields: impl Iterator<Item = InterpResult<'tcx, Self::V>>
) -> InterpResult<'tcx>

Visits this value as an aggregate, you are getting an iterator yielding all the fields (still in an InterpResult, you have to do error handling yourself). Recurses into the fields.

fn visit_value(&mut self, mplace: &MPlaceTy<'tcx>) -> InterpResult<'tcx>

Visits the given value, dispatching as appropriate to more specialized visitors.

fn read_discriminant(
    &mut self,
    op: &OpTy<'tcx, M::PointerTag>
) -> InterpResult<'tcx, VariantIdx>

read_discriminant can be hooked for better error messages.

fn visit_union(
    &mut self,
    _v: &Self::V,
    _fields: NonZeroUsize
) -> InterpResult<'tcx>

Visits the given value as a union. No automatic recursion can happen here.

fn visit_field(
    &mut self,
    _old_val: &Self::V,
    _field: usize,
    new_val: &Self::V
) -> InterpResult<'tcx>

Called each time we recurse down to a field of a “product-like” aggregate (structs, tuples, arrays and the like, but not enums), passing in old (outer) and new (inner) value. This gives the visitor the chance to track the stack of nested fields that we are descending through.

fn visit_variant(
    &mut self,
    _old_val: &Self::V,
    _variant: VariantIdx,
    new_val: &Self::V
) -> InterpResult<'tcx>

Called when recursing into an enum variant. This gives the visitor the chance to track the stack of nested fields that we are descending through.

fn walk_aggregate(
    &mut self,
    v: &Self::V,
    fields: impl Iterator<Item = InterpResult<'tcx, Self::V>>
) -> InterpResult<'tcx>

fn walk_value(&mut self, v: &Self::V) -> InterpResult<'tcx>