diff options
3 files changed, 33 insertions, 6 deletions
diff --git a/compiler/rustc_mir/src/transform/check_consts/ops.rs b/compiler/rustc_mir/src/transform/check_consts/ops.rs index 4af355310ae..032cbc23a3f 100644 --- a/compiler/rustc_mir/src/transform/check_consts/ops.rs +++ b/compiler/rustc_mir/src/transform/check_consts/ops.rs @@ -1,6 +1,6 @@ //! Concrete error types for all operations which may be invalid in a certain const context. -use rustc_errors::struct_span_err; +use rustc_errors::{struct_span_err, Applicability}; use rustc_hir as hir; use rustc_hir::def_id::DefId; use rustc_session::config::nightly_options; @@ -16,7 +16,29 @@ pub fn non_const<O: NonConstOp>(ccx: &ConstCx<'_, '_>, op: O, span: Span) { let gate = match op.status_in_item(ccx) { Status::Allowed => return, - Status::Unstable(gate) if ccx.tcx.features().enabled(gate) => return, + + Status::Unstable(gate) if ccx.tcx.features().enabled(gate) => { + let unstable_in_stable = ccx.const_kind() == hir::ConstContext::ConstFn + && ccx.tcx.features().enabled(sym::staged_api) + && !ccx.tcx.has_attr(ccx.def_id.to_def_id(), sym::rustc_const_unstable) + && !super::allow_internal_unstable(ccx.tcx, ccx.def_id.to_def_id(), gate); + + if unstable_in_stable { + ccx.tcx.sess + .struct_span_err(span, &format!("`#[feature({})]` cannot be depended on in a const-stable function", gate.as_str())) + .span_suggestion( + ccx.body.span, + "if it is not part of the public API, make this function unstably const", + concat!(r#"#[rustc_const_unstable(feature = "...", issue = "...")]"#, '\n').to_owned(), + Applicability::HasPlaceholders, + ) + .help("otherwise `#[allow_internal_unstable]` can be used to bypass stability checks") + .emit(); + } + + return; + } + Status::Unstable(gate) => Some(gate), Status::Forbidden => None, }; diff --git a/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs b/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs index a2e5c905612..0228f2d7de0 100644 --- a/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs +++ b/compiler/rustc_mir/src/transform/check_consts/post_drop_elaboration.rs @@ -2,7 +2,7 @@ use rustc_hir::def_id::LocalDefId; use rustc_middle::mir::visit::Visitor; use rustc_middle::mir::{self, BasicBlock, Location}; use rustc_middle::ty::TyCtxt; -use rustc_span::Span; +use rustc_span::{sym, Span}; use super::ops; use super::qualifs::{NeedsDrop, Qualif}; @@ -11,7 +11,12 @@ use super::ConstCx; /// Returns `true` if we should use the more precise live drop checker that runs after drop /// elaboration. -pub fn checking_enabled(tcx: TyCtxt<'tcx>) -> bool { +pub fn checking_enabled(tcx: TyCtxt<'tcx>, def_id: LocalDefId) -> bool { + // Const-stable functions must always use the stable live drop checker. + if tcx.features().staged_api && !tcx.has_attr(def_id.to_def_id(), sym::rustc_const_unstable) { + return false; + } + tcx.features().const_precise_live_drops } @@ -25,7 +30,7 @@ pub fn check_live_drops(tcx: TyCtxt<'tcx>, def_id: LocalDefId, body: &mir::Body< return; } - if !checking_enabled(tcx) { + if !checking_enabled(tcx, def_id) { return; } diff --git a/compiler/rustc_mir/src/transform/check_consts/validation.rs b/compiler/rustc_mir/src/transform/check_consts/validation.rs index ebba7f29663..0501302b761 100644 --- a/compiler/rustc_mir/src/transform/check_consts/validation.rs +++ b/compiler/rustc_mir/src/transform/check_consts/validation.rs @@ -551,7 +551,7 @@ impl Visitor<'tcx> for Validator<'mir, 'tcx> { | TerminatorKind::DropAndReplace { place: dropped_place, .. } => { // If we are checking live drops after drop-elaboration, don't emit duplicate // errors here. - if super::post_drop_elaboration::checking_enabled(self.tcx) { + if super::post_drop_elaboration::checking_enabled(self.tcx, self.def_id) { return; } |