bjoernager/rust
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Retroactively feature gate ConstArgKind::Path

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This commit is contained in:
Boxy 2024-08-19 01:14:09 +01:00
parent f04f6ca36d
commit b8eedfa3d2
41 changed files with 425 additions and 206 deletions
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32
compiler/rustc_middle/src/ty/consts.rs
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@ -240,7 +240,7 @@ impl<'tcx> Const<'tcx> {
let ty = tcx.type_of(def).no_bound_vars().expect("const parameter types cannot be generic");
match Self::try_from_lit(tcx, ty, expr) {
match Self::try_from_lit_or_param(tcx, ty, expr) {
Some(v) => v,
None => ty::Const::new_unevaluated(
tcx,
@ -281,7 +281,11 @@ impl<'tcx> Const<'tcx> {
}
#[instrument(skip(tcx), level = "debug")]
fn try_from_lit(tcx: TyCtxt<'tcx>, ty: Ty<'tcx>, expr: &'tcx hir::Expr<'tcx>) -> Option<Self> {
fn try_from_lit_or_param(
tcx: TyCtxt<'tcx>,
ty: Ty<'tcx>,
expr: &'tcx hir::Expr<'tcx>,
) -> Option<Self> {
// Unwrap a block, so that e.g. `{ P }` is recognised as a parameter. Const arguments
// currently have to be wrapped in curly brackets, so it's necessary to special-case.
let expr = match &expr.kind {
@ -291,6 +295,22 @@ impl<'tcx> Const<'tcx> {
_ => expr,
};
if let hir::ExprKind::Path(
qpath @ hir::QPath::Resolved(
_,
&hir::Path { res: Res::Def(DefKind::ConstParam, _), .. },
),
) = expr.kind
{
if tcx.features().const_arg_path {
span_bug!(
expr.span,
"try_from_lit: received const param which shouldn't be possible"
);
}
return Some(Const::from_param(tcx, qpath, expr.hir_id));
};
let lit_input = match expr.kind {
hir::ExprKind::Lit(lit) => Some(LitToConstInput { lit: &lit.node, ty, neg: false }),
hir::ExprKind::Unary(hir::UnOp::Neg, expr) => match expr.kind {
@ -318,14 +338,6 @@ impl<'tcx> Const<'tcx> {
}
}
if let hir::ExprKind::Path(hir::QPath::Resolved(
_,
&hir::Path { res: Res::Def(DefKind::ConstParam, _), .. },
)) = expr.kind
{
span_bug!(expr.span, "try_from_lit: received const param which shouldn't be possible")
}
None
}