From bd146c72ac2faf6bbf189ad92d06e0bcd6cc92fc Mon Sep 17 00:00:00 2001 From: Michael Goulet Date: Wed, 26 Apr 2023 18:22:32 +0000 Subject: [PATCH] Explicitly reject negative and reservation drop impls --- compiler/rustc_hir_analysis/messages.ftl | 4 ++++ .../rustc_hir_analysis/src/check/dropck.rs | 17 ++++++++++++++++- compiler/rustc_hir_analysis/src/errors.rs | 14 ++++++++++++++ compiler/rustc_middle/src/ty/util.rs | 10 +++++----- tests/ui/consts/const-block-const-bound.rs | 6 ------ tests/ui/consts/const-block-const-bound.stderr | 18 ++---------------- tests/ui/dropck/negative.rs | 7 +++++++ tests/ui/dropck/negative.stderr | 8 ++++++++ tests/ui/dropck/reservation.rs | 10 ++++++++++ tests/ui/dropck/reservation.stderr | 8 ++++++++ 10 files changed, 74 insertions(+), 28 deletions(-) create mode 100644 tests/ui/dropck/negative.rs create mode 100644 tests/ui/dropck/negative.stderr create mode 100644 tests/ui/dropck/reservation.rs create mode 100644 tests/ui/dropck/reservation.stderr diff --git a/compiler/rustc_hir_analysis/messages.ftl b/compiler/rustc_hir_analysis/messages.ftl index 5d45d09797b..4c4af9b6908 100644 --- a/compiler/rustc_hir_analysis/messages.ftl +++ b/compiler/rustc_hir_analysis/messages.ftl @@ -276,3 +276,7 @@ hir_analysis_const_specialize = cannot specialize on const impl with non-const i hir_analysis_static_specialize = cannot specialize on `'static` lifetime hir_analysis_missing_tilde_const = missing `~const` qualifier for specialization + +hir_analysis_drop_impl_negative = negative `Drop` impls are not supported + +hir_analysis_drop_impl_reservation = reservation `Drop` impls are not supported diff --git a/compiler/rustc_hir_analysis/src/check/dropck.rs b/compiler/rustc_hir_analysis/src/check/dropck.rs index 111bf5e5455..703e389a838 100644 --- a/compiler/rustc_hir_analysis/src/check/dropck.rs +++ b/compiler/rustc_hir_analysis/src/check/dropck.rs @@ -1,7 +1,6 @@ // FIXME(@lcnr): Move this module out of `rustc_hir_analysis`. // // We don't do any drop checking during hir typeck. -use crate::hir::def_id::{DefId, LocalDefId}; use rustc_errors::{struct_span_err, ErrorGuaranteed}; use rustc_middle::ty::error::TypeError; use rustc_middle::ty::relate::{Relate, RelateResult, TypeRelation}; @@ -9,6 +8,9 @@ use rustc_middle::ty::util::IgnoreRegions; use rustc_middle::ty::{self, Predicate, Ty, TyCtxt}; +use crate::errors; +use crate::hir::def_id::{DefId, LocalDefId}; + /// This function confirms that the `Drop` implementation identified by /// `drop_impl_did` is not any more specialized than the type it is /// attached to (Issue #8142). @@ -27,6 +29,19 @@ /// cannot do `struct S; impl Drop for S { ... }`). /// pub fn check_drop_impl(tcx: TyCtxt<'_>, drop_impl_did: DefId) -> Result<(), ErrorGuaranteed> { + match tcx.impl_polarity(drop_impl_did) { + ty::ImplPolarity::Positive => {} + ty::ImplPolarity::Negative => { + return Err(tcx.sess.emit_err(errors::DropImplPolarity::Negative { + span: tcx.def_span(drop_impl_did), + })); + } + ty::ImplPolarity::Reservation => { + return Err(tcx.sess.emit_err(errors::DropImplPolarity::Reservation { + span: tcx.def_span(drop_impl_did), + })); + } + } let dtor_self_type = tcx.type_of(drop_impl_did).subst_identity(); let dtor_predicates = tcx.predicates_of(drop_impl_did); match dtor_self_type.kind() { diff --git a/compiler/rustc_hir_analysis/src/errors.rs b/compiler/rustc_hir_analysis/src/errors.rs index f82169dee98..ba3039272f5 100644 --- a/compiler/rustc_hir_analysis/src/errors.rs +++ b/compiler/rustc_hir_analysis/src/errors.rs @@ -815,3 +815,17 @@ pub(crate) struct MissingTildeConst { #[primary_span] pub span: Span, } + +#[derive(Diagnostic)] +pub(crate) enum DropImplPolarity { + #[diag(hir_analysis_drop_impl_negative)] + Negative { + #[primary_span] + span: Span, + }, + #[diag(hir_analysis_drop_impl_reservation)] + Reservation { + #[primary_span] + span: Span, + }, +} diff --git a/compiler/rustc_middle/src/ty/util.rs b/compiler/rustc_middle/src/ty/util.rs index c77985c6bd6..e5b2d342452 100644 --- a/compiler/rustc_middle/src/ty/util.rs +++ b/compiler/rustc_middle/src/ty/util.rs @@ -360,16 +360,16 @@ pub fn calculate_dtor( let ty = self.type_of(adt_did).subst_identity(); let mut dtor_candidate = None; self.for_each_relevant_impl(drop_trait, ty, |impl_did| { - let Some(item_id) = self.associated_item_def_ids(impl_did).first() else { - self.sess.delay_span_bug(self.def_span(impl_did), "Drop impl without drop function"); - return; - }; - if validate(self, impl_did).is_err() { // Already `ErrorGuaranteed`, no need to delay a span bug here. return; } + let Some(item_id) = self.associated_item_def_ids(impl_did).first() else { + self.sess.delay_span_bug(self.def_span(impl_did), "Drop impl without drop function"); + return; + }; + if let Some((old_item_id, _)) = dtor_candidate { self.sess .struct_span_err(self.def_span(item_id), "multiple drop impls found") diff --git a/tests/ui/consts/const-block-const-bound.rs b/tests/ui/consts/const-block-const-bound.rs index 42aa0216b87..3704a1a5a39 100644 --- a/tests/ui/consts/const-block-const-bound.rs +++ b/tests/ui/consts/const-block-const-bound.rs @@ -11,15 +11,9 @@ impl Drop for UnconstDrop { fn drop(&mut self) {} } -struct NonDrop; - -impl !Drop for NonDrop {} - fn main() { const { f(UnconstDrop); //~^ ERROR can't drop - f(NonDrop); - //~^ ERROR can't drop } } diff --git a/tests/ui/consts/const-block-const-bound.stderr b/tests/ui/consts/const-block-const-bound.stderr index fef4914fad5..caf24e7afcf 100644 --- a/tests/ui/consts/const-block-const-bound.stderr +++ b/tests/ui/consts/const-block-const-bound.stderr @@ -1,5 +1,5 @@ error[E0277]: can't drop `UnconstDrop` in const contexts - --> $DIR/const-block-const-bound.rs:20:9 + --> $DIR/const-block-const-bound.rs:16:9 | LL | f(UnconstDrop); | ^^^^^^^^^^^^^^ the trait `~const Destruct` is not implemented for `UnconstDrop` @@ -12,20 +12,6 @@ LL | &f(UnconstDrop); LL | &mut f(UnconstDrop); | ++++ -error[E0277]: can't drop `NonDrop` in const contexts - --> $DIR/const-block-const-bound.rs:22:9 - | -LL | f(NonDrop); - | ^^^^^^^^^^ the trait `~const Destruct` is not implemented for `NonDrop` - | - = note: the trait bound `NonDrop: ~const Destruct` is not satisfied -help: consider borrowing here - | -LL | &f(NonDrop); - | + -LL | &mut f(NonDrop); - | ++++ - -error: aborting due to 2 previous errors +error: aborting due to previous error For more information about this error, try `rustc --explain E0277`. diff --git a/tests/ui/dropck/negative.rs b/tests/ui/dropck/negative.rs new file mode 100644 index 00000000000..ae63632b55e --- /dev/null +++ b/tests/ui/dropck/negative.rs @@ -0,0 +1,7 @@ +#![feature(negative_impls)] + +struct NonDrop; +impl !Drop for NonDrop {} +//~^ ERROR negative `Drop` impls are not supported + +fn main() {} diff --git a/tests/ui/dropck/negative.stderr b/tests/ui/dropck/negative.stderr new file mode 100644 index 00000000000..d613e30b5ea --- /dev/null +++ b/tests/ui/dropck/negative.stderr @@ -0,0 +1,8 @@ +error: negative `Drop` impls are not supported + --> $DIR/negative.rs:4:1 + | +LL | impl !Drop for NonDrop {} + | ^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to previous error + diff --git a/tests/ui/dropck/reservation.rs b/tests/ui/dropck/reservation.rs new file mode 100644 index 00000000000..f7199d4ec44 --- /dev/null +++ b/tests/ui/dropck/reservation.rs @@ -0,0 +1,10 @@ +#![feature(rustc_attrs)] + +struct ReservedDrop; +#[rustc_reservation_impl = "message"] +impl Drop for ReservedDrop { +//~^ ERROR reservation `Drop` impls are not supported + fn drop(&mut self) {} +} + +fn main() {} diff --git a/tests/ui/dropck/reservation.stderr b/tests/ui/dropck/reservation.stderr new file mode 100644 index 00000000000..19325d6ed44 --- /dev/null +++ b/tests/ui/dropck/reservation.stderr @@ -0,0 +1,8 @@ +error: reservation `Drop` impls are not supported + --> $DIR/reservation.rs:5:1 + | +LL | impl Drop for ReservedDrop { + | ^^^^^^^^^^^^^^^^^^^^^^^^^^ + +error: aborting due to previous error +