From 912783402fe2f0d1fff41b047b0918e7e58e18ae Mon Sep 17 00:00:00 2001 From: David Wood Date: Wed, 8 Feb 2023 13:25:38 +0000 Subject: const_eval: `implies_by` in `rustc_const_unstable` Extend support for `implies_by` (from `#[stable]` and `#[unstable]`) to `#[rustc_const_stable]` and `#[rustc_const_unstable]`. Signed-off-by: David Wood --- compiler/rustc_const_eval/src/const_eval/fn_queries.rs | 13 ++++++++++--- .../rustc_const_eval/src/transform/check_consts/check.rs | 16 ++++++++++++---- 2 files changed, 22 insertions(+), 7 deletions(-) (limited to 'compiler/rustc_const_eval/src') diff --git a/compiler/rustc_const_eval/src/const_eval/fn_queries.rs b/compiler/rustc_const_eval/src/const_eval/fn_queries.rs index f92277b1113..b7e05376c0e 100644 --- a/compiler/rustc_const_eval/src/const_eval/fn_queries.rs +++ b/compiler/rustc_const_eval/src/const_eval/fn_queries.rs @@ -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 { +/// 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)> { 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 } diff --git a/compiler/rustc_const_eval/src/transform/check_consts/check.rs b/compiler/rustc_const_eval/src/transform/check_consts/check.rs index 1a23b06d2e8..d11cc65da16 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -926,15 +926,24 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> { // If the `const fn` we are trying to call is not const-stable, ensure that we have // the proper feature gate enabled. - if let Some(gate) = is_unstable_const_fn(tcx, callee) { + if let Some((gate, implied_by)) = is_unstable_const_fn(tcx, callee) { trace!(?gate, "calling unstable const fn"); if self.span.allows_unstable(gate) { return; } + if let Some(implied_by_gate) = implied_by && self.span.allows_unstable(implied_by_gate) { + return; + } // Calling an unstable function *always* requires that the corresponding gate - // be enabled, even if the function has `#[rustc_allow_const_fn_unstable(the_gate)]`. - if !tcx.features().declared_lib_features.iter().any(|&(sym, _)| sym == gate) { + // (or implied gate) be enabled, even if the function has + // `#[rustc_allow_const_fn_unstable(the_gate)]`. + let gate_declared = |gate| { + tcx.features().declared_lib_features.iter().any(|&(sym, _)| sym == gate) + }; + let feature_gate_declared = gate_declared(gate); + let implied_gate_declared = implied_by.map(gate_declared).unwrap_or(false); + if !feature_gate_declared && !implied_gate_declared { self.check_op(ops::FnCallUnstable(callee, Some(gate))); return; } @@ -947,7 +956,6 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> { } // Otherwise, we are something const-stable calling a const-unstable fn. - if super::rustc_allow_const_fn_unstable(tcx, caller, gate) { trace!("rustc_allow_const_fn_unstable gate active"); return; -- cgit 1.4.1-3-g733a5