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use super::Const;
use crate::mir;
use crate::ty::abstract_const::CastKind;
use crate::ty::{self, visit::TypeVisitableExt as _, List, Ty, TyCtxt};
use rustc_macros::{extension, HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable};
#[extension(pub(crate) trait UnevaluatedConstEvalExt<'tcx>)]
impl<'tcx> ty::UnevaluatedConst<'tcx> {
/// FIXME(RalfJung): I cannot explain what this does or why it makes sense, but not doing this
/// hurts performance.
#[inline]
fn prepare_for_eval(
self,
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
) -> (ty::ParamEnv<'tcx>, Self) {
// HACK(eddyb) this erases lifetimes even though `const_eval_resolve`
// also does later, but we want to do it before checking for
// inference variables.
// Note that we erase regions *before* calling `with_reveal_all_normalized`,
// so that we don't try to invoke this query with
// any region variables.
// HACK(eddyb) when the query key would contain inference variables,
// attempt using identity args and `ParamEnv` instead, that will succeed
// when the expression doesn't depend on any parameters.
// FIXME(eddyb, skinny121) pass `InferCtxt` into here when it's available, so that
// we can call `infcx.const_eval_resolve` which handles inference variables.
if (param_env, self).has_non_region_infer() {
(
tcx.param_env(self.def),
ty::UnevaluatedConst {
def: self.def,
args: ty::GenericArgs::identity_for_item(tcx, self.def),
},
)
} else {
(tcx.erase_regions(param_env).with_reveal_all_normalized(tcx), tcx.erase_regions(self))
}
}
}
#[derive(Copy, Clone, Eq, PartialEq, Hash)]
#[derive(HashStable, TyEncodable, TyDecodable, TypeVisitable, TypeFoldable)]
pub enum Expr<'tcx> {
Binop(mir::BinOp, Const<'tcx>, Const<'tcx>),
UnOp(mir::UnOp, Const<'tcx>),
FunctionCall(Const<'tcx>, &'tcx List<Const<'tcx>>),
Cast(CastKind, Const<'tcx>, Ty<'tcx>),
}
#[cfg(target_pointer_width = "64")]
rustc_data_structures::static_assert_size!(Expr<'_>, 24);
|
