bjoernager/rust
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const_eval: implies_by in rustc_const_unstable

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Extend support for `implies_by` (from `#[stable]` and `#[unstable]`)
to `#[rustc_const_stable]` and `#[rustc_const_unstable]`.

Signed-off-by: David Wood <david.wood@huawei.com>
This commit is contained in:
David Wood 2023-02-08 13:25:38 +00:00
parent 6eb9f2dd67
commit 912783402f
12 changed files with 177 additions and 7 deletions
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13
compiler/rustc_const_eval/src/const_eval/fn_queries.rs
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@ -1,3 +1,4 @@
use rustc_attr as attr;
use rustc_hir as hir;
use rustc_hir::def::DefKind;
use rustc_hir::def_id::{DefId, LocalDefId};
@ -5,11 +6,17 @@ use rustc_middle::ty::query::Providers;
use rustc_middle::ty::{DefIdTree, TyCtxt};
use rustc_span::symbol::Symbol;
/// Whether the `def_id` is an unstable const fn and what feature gate is necessary to enable it
pub fn is_unstable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<Symbol> {
/// Whether the `def_id` is an unstable const fn and what feature gate(s) are necessary to enable
/// it.
pub fn is_unstable_const_fn(tcx: TyCtxt<'_>, def_id: DefId) -> Option<(Symbol, Option<Symbol>)> {
if tcx.is_const_fn_raw(def_id) {
let const_stab = tcx.lookup_const_stability(def_id)?;
if const_stab.is_const_unstable() { Some(const_stab.feature) } else { None }
match const_stab.level {
attr::StabilityLevel::Unstable { implied_by, .. } => {
Some((const_stab.feature, implied_by))
}
attr::StabilityLevel::Stable { .. } => None,
}
} else {
None
}