use std::assert_matches::assert_matches;
use rustc_macros::{HashStable, TyDecodable, TyEncodable, TypeFoldable, TypeVisitable, extension};
use super::Const;
use crate::mir;
use crate::ty::abstract_const::CastKind;
use crate::ty::visit::TypeVisitableExt as _;
use crate::ty::{self, Ty, TyCtxt};
#[extension(pub(crate) trait UnevaluatedConstEvalExt<'tcx>)]
impl<'tcx> ty::UnevaluatedConst<'tcx> {
#[inline]
fn prepare_for_eval(
self,
tcx: TyCtxt<'tcx>,
param_env: ty::ParamEnv<'tcx>,
) -> (ty::ParamEnv<'tcx>, Self) {
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, Debug)]
#[derive(HashStable, TyEncodable, TyDecodable, TypeVisitable, TypeFoldable)]
pub enum ExprKind {
Binop(mir::BinOp),
UnOp(mir::UnOp),
FunctionCall,
Cast(CastKind),
}
#[derive(Copy, Clone, Eq, PartialEq, Hash)]
#[derive(HashStable, TyEncodable, TyDecodable, TypeVisitable, TypeFoldable)]
pub struct Expr<'tcx> {
pub kind: ExprKind,
args: ty::GenericArgsRef<'tcx>,
}
impl<'tcx> rustc_type_ir::inherent::ExprConst<TyCtxt<'tcx>> for Expr<'tcx> {
fn args(self) -> ty::GenericArgsRef<'tcx> {
self.args
}
}
impl<'tcx> Expr<'tcx> {
pub fn new_binop(
tcx: TyCtxt<'tcx>,
binop: mir::BinOp,
lhs_ty: Ty<'tcx>,
rhs_ty: Ty<'tcx>,
lhs_ct: Const<'tcx>,
rhs_ct: Const<'tcx>,
) -> Self {
let args = tcx.mk_args_from_iter::<_, ty::GenericArg<'tcx>>(
[lhs_ty.into(), rhs_ty.into(), lhs_ct.into(), rhs_ct.into()].into_iter(),
);
Self { kind: ExprKind::Binop(binop), args }
}
pub fn binop_args(self) -> (Ty<'tcx>, Ty<'tcx>, Const<'tcx>, Const<'tcx>) {
assert_matches!(self.kind, ExprKind::Binop(_));
match self.args().as_slice() {
[lhs_ty, rhs_ty, lhs_ct, rhs_ct] => (
lhs_ty.expect_ty(),
rhs_ty.expect_ty(),
lhs_ct.expect_const(),
rhs_ct.expect_const(),
),
_ => bug!("Invalid args for `Binop` expr {self:?}"),
}
}
pub fn new_unop(tcx: TyCtxt<'tcx>, unop: mir::UnOp, ty: Ty<'tcx>, ct: Const<'tcx>) -> Self {
let args =
tcx.mk_args_from_iter::<_, ty::GenericArg<'tcx>>([ty.into(), ct.into()].into_iter());
Self { kind: ExprKind::UnOp(unop), args }
}
pub fn unop_args(self) -> (Ty<'tcx>, Const<'tcx>) {
assert_matches!(self.kind, ExprKind::UnOp(_));
match self.args().as_slice() {
[ty, ct] => (ty.expect_ty(), ct.expect_const()),
_ => bug!("Invalid args for `UnOp` expr {self:?}"),
}
}
pub fn new_call(
tcx: TyCtxt<'tcx>,
func_ty: Ty<'tcx>,
func_expr: Const<'tcx>,
arguments: impl IntoIterator<Item = Const<'tcx>>,
) -> Self {
let args = tcx.mk_args_from_iter::<_, ty::GenericArg<'tcx>>(
[func_ty.into(), func_expr.into()]
.into_iter()
.chain(arguments.into_iter().map(|ct| ct.into())),
);
Self { kind: ExprKind::FunctionCall, args }
}
pub fn call_args(self) -> (Ty<'tcx>, Const<'tcx>, impl Iterator<Item = Const<'tcx>>) {
assert_matches!(self.kind, ExprKind::FunctionCall);
match self.args().as_slice() {
[func_ty, func, rest @ ..] => (
func_ty.expect_ty(),
func.expect_const(),
rest.iter().map(|arg| arg.expect_const()),
),
_ => bug!("Invalid args for `Call` expr {self:?}"),
}
}
pub fn new_cast(
tcx: TyCtxt<'tcx>,
cast: CastKind,
value_ty: Ty<'tcx>,
value: Const<'tcx>,
to_ty: Ty<'tcx>,
) -> Self {
let args = tcx.mk_args_from_iter::<_, ty::GenericArg<'tcx>>(
[value_ty.into(), value.into(), to_ty.into()].into_iter(),
);
Self { kind: ExprKind::Cast(cast), args }
}
pub fn cast_args(self) -> (Ty<'tcx>, Const<'tcx>, Ty<'tcx>) {
assert_matches!(self.kind, ExprKind::Cast(_));
match self.args().as_slice() {
[value_ty, value, to_ty] => {
(value_ty.expect_ty(), value.expect_const(), to_ty.expect_ty())
}
_ => bug!("Invalid args for `Cast` expr {self:?}"),
}
}
pub fn new(kind: ExprKind, args: ty::GenericArgsRef<'tcx>) -> Self {
Self { kind, args }
}
pub fn args(self) -> ty::GenericArgsRef<'tcx> {
self.args
}
}
#[cfg(target_pointer_width = "64")]
rustc_data_structures::static_assert_size!(Expr<'_>, 16);