Struct rustc_mir::transform::promote_consts::Validator

struct Validator<'a, 'tcx> {
    ccx: &'a ConstCx<'a, 'tcx>,
    temps: &'a IndexVec<Local, TempState>,
    explicit: bool,
}

Checks whether locals that appear in a promotion context (Candidate) are actually promotable.

This wraps an Item, and has access to all fields of that Item via Deref coercion.

Fields

ccx: &'a ConstCx<'a, 'tcx>

temps: &'a IndexVec<Local, TempState>

explicit: bool

Explicit promotion happens e.g. for constant arguments declared via rustc_args_required_const. Implicit promotion has almost the same rules, except that disallows const fn except for those marked #[rustc_promotable]. This is to avoid changing a legitimate run-time operation into a failing compile-time operation e.g. due to addresses being compared inside the function.

Implementations

impl<'tcx> Validator<'_, 'tcx>

fn validate_candidate(&self, candidate: Candidate) -> Result<(), Unpromotable>

fn qualif_local<Q: Qualif>(&self, local: Local) -> bool

fn validate_local(&self, local: Local) -> Result<(), Unpromotable>

fn validate_place(&self, place: PlaceRef<'tcx>) -> Result<(), Unpromotable>

fn validate_operand(&self, operand: &Operand<'tcx>) -> Result<(), Unpromotable>

fn validate_ref(
    &self,
    kind: BorrowKind,
    place: &Place<'tcx>
) -> Result<(), Unpromotable>

fn validate_rvalue(&self, rvalue: &Rvalue<'tcx>) -> Result<(), Unpromotable>

fn validate_call(
    &self,
    callee: &Operand<'tcx>,
    args: &[Operand<'tcx>]
) -> Result<(), Unpromotable>

Methods from Deref<Target = ConstCx<'a, 'tcx>>

pub fn def_id(&self) -> LocalDefId

pub fn const_kind(&self) -> ConstContext

Returns the kind of const context this Item represents (const, static, etc.).

Panics if this Item is not const.

pub fn is_const_stable_const_fn(&self) -> bool

pub fn fn_sig(&self) -> Option<&'tcx FnSig<'tcx>>

Returns the function signature of the item being const-checked if it is a fn or const fn.

Trait Implementations

impl<'a, 'tcx> Deref for Validator<'a, 'tcx>

type Target = ConstCx<'a, 'tcx>

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.