| use super::Const; |
| use crate::mir; |
| use crate::ty::abstract_const::CastKind; |
| use crate::ty::GenericArgsRef; |
| use crate::ty::{self, visit::TypeVisitableExt as _, List, Ty, TyCtxt}; |
| use rustc_hir::def_id::DefId; |
| use rustc_macros::HashStable; |
| |
| /// An unevaluated (potentially generic) constant used in the type-system. |
| #[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord, TyEncodable, TyDecodable)] |
| #[derive(Hash, HashStable, TypeFoldable, TypeVisitable)] |
| pub struct UnevaluatedConst<'tcx> { |
| pub def: DefId, |
| pub args: GenericArgsRef<'tcx>, |
| } |
| |
| impl rustc_errors::IntoDiagArg for UnevaluatedConst<'_> { |
| fn into_diag_arg(self) -> rustc_errors::DiagArgValue { |
| format!("{self:?}").into_diag_arg() |
| } |
| } |
| |
| impl<'tcx> UnevaluatedConst<'tcx> { |
| /// FIXME(RalfJung): I cannot explain what this does or why it makes sense, but not doing this |
| /// hurts performance. |
| #[inline] |
| pub(crate) 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)) |
| } |
| } |
| } |
| |
| impl<'tcx> UnevaluatedConst<'tcx> { |
| #[inline] |
| pub fn new(def: DefId, args: GenericArgsRef<'tcx>) -> UnevaluatedConst<'tcx> { |
| UnevaluatedConst { def, args } |
| } |
| } |
| |
| #[derive(Copy, Clone, Eq, PartialEq, PartialOrd, Ord, 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(all(target_arch = "x86_64", target_pointer_width = "64"))] |
| static_assert_size!(Expr<'_>, 24); |
| |
| #[cfg(all(target_arch = "x86_64", target_pointer_width = "64"))] |
| static_assert_size!(super::ConstKind<'_>, 32); |