diff options
Diffstat (limited to 'compiler/rustc_const_eval/src')
8 files changed, 50 insertions, 10 deletions
diff --git a/compiler/rustc_const_eval/src/interpret/eval_context.rs b/compiler/rustc_const_eval/src/interpret/eval_context.rs index 94a5cc67d31..af7dfbef2ff 100644 --- a/compiler/rustc_const_eval/src/interpret/eval_context.rs +++ b/compiler/rustc_const_eval/src/interpret/eval_context.rs @@ -13,7 +13,7 @@ use rustc_middle::ty::layout::{ self, FnAbiError, FnAbiOfHelpers, FnAbiRequest, LayoutError, LayoutOf, LayoutOfHelpers, TyAndLayout, }; -use rustc_middle::ty::{self, GenericArgsRef, ParamEnv, Ty, TyCtxt, TypeFoldable}; +use rustc_middle::ty::{self, GenericArgsRef, ParamEnv, Ty, TyCtxt, TypeFoldable, Variance}; use rustc_mir_dataflow::storage::always_storage_live_locals; use rustc_session::Limit; use rustc_span::Span; @@ -384,7 +384,7 @@ pub(super) fn mir_assign_valid_types<'tcx>( // all normal lifetimes are erased, higher-ranked types with their // late-bound lifetimes are still around and can lead to type // differences. - if util::is_subtype(tcx, param_env, src.ty, dest.ty) { + if util::relate_types(tcx, param_env, Variance::Covariant, src.ty, dest.ty) { // Make sure the layout is equal, too -- just to be safe. Miri really // needs layout equality. For performance reason we skip this check when // the types are equal. Equal types *can* have different layouts when diff --git a/compiler/rustc_const_eval/src/interpret/projection.rs b/compiler/rustc_const_eval/src/interpret/projection.rs index f462c13816e..70df3d8fd78 100644 --- a/compiler/rustc_const_eval/src/interpret/projection.rs +++ b/compiler/rustc_const_eval/src/interpret/projection.rs @@ -319,6 +319,8 @@ where OpaqueCast(ty) => { span_bug!(self.cur_span(), "OpaqueCast({ty}) encountered after borrowck") } + // We don't want anything happening here, this is here as a dummy. + Subtype(_) => base.transmute(base.layout(), self)?, Field(field, _) => self.project_field(base, field.index())?, Downcast(_, variant) => self.project_downcast(base, variant)?, Deref => self.deref_pointer(&base.to_op(self)?)?.into(), 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 9d00ade477a..d380849fefe 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/check.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/check.rs @@ -664,6 +664,7 @@ impl<'tcx> Visitor<'tcx> for Checker<'_, 'tcx> { | ProjectionElem::Downcast(..) | ProjectionElem::OpaqueCast(..) | ProjectionElem::Subslice { .. } + | ProjectionElem::Subtype(..) | ProjectionElem::Field(..) | ProjectionElem::Index(_) => {} } diff --git a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs index 34e9b76c484..de3186a53c1 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs @@ -306,6 +306,7 @@ where ProjectionElem::Index(index) if in_local(index) => return true, ProjectionElem::Deref + | ProjectionElem::Subtype(_) | ProjectionElem::Field(_, _) | ProjectionElem::OpaqueCast(_) | ProjectionElem::ConstantIndex { .. } diff --git a/compiler/rustc_const_eval/src/transform/promote_consts.rs b/compiler/rustc_const_eval/src/transform/promote_consts.rs index 4a9977add78..8ede3bdd2b6 100644 --- a/compiler/rustc_const_eval/src/transform/promote_consts.rs +++ b/compiler/rustc_const_eval/src/transform/promote_consts.rs @@ -357,7 +357,9 @@ impl<'tcx> Validator<'_, 'tcx> { return Err(Unpromotable); } - ProjectionElem::ConstantIndex { .. } | ProjectionElem::Subslice { .. } => {} + ProjectionElem::ConstantIndex { .. } + | ProjectionElem::Subtype(_) + | ProjectionElem::Subslice { .. } => {} ProjectionElem::Index(local) => { let mut promotable = false; diff --git a/compiler/rustc_const_eval/src/transform/validate.rs b/compiler/rustc_const_eval/src/transform/validate.rs index 18b22882e7d..4711f7b47cc 100644 --- a/compiler/rustc_const_eval/src/transform/validate.rs +++ b/compiler/rustc_const_eval/src/transform/validate.rs @@ -7,7 +7,7 @@ use rustc_infer::traits::Reveal; use rustc_middle::mir::interpret::Scalar; use rustc_middle::mir::visit::{NonUseContext, PlaceContext, Visitor}; use rustc_middle::mir::*; -use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt}; +use rustc_middle::ty::{self, InstanceDef, ParamEnv, Ty, TyCtxt, TypeVisitableExt, Variance}; use rustc_mir_dataflow::impls::MaybeStorageLive; use rustc_mir_dataflow::storage::always_storage_live_locals; use rustc_mir_dataflow::{Analysis, ResultsCursor}; @@ -16,6 +16,8 @@ use rustc_target::spec::abi::Abi; use crate::util::is_within_packed; +use crate::util::relate_types; + #[derive(Copy, Clone, Debug, PartialEq, Eq)] enum EdgeKind { Unwind, @@ -602,7 +604,15 @@ impl<'a, 'tcx> TypeChecker<'a, 'tcx> { return true; } - crate::util::is_subtype(self.tcx, self.param_env, src, dest) + // After borrowck subtyping should be fully explicit via + // `Subtype` projections. + let variance = if self.mir_phase >= MirPhase::Runtime(RuntimePhase::Initial) { + Variance::Invariant + } else { + Variance::Covariant + }; + + crate::util::relate_types(self.tcx, self.param_env, variance, src, dest) } } @@ -753,6 +763,23 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { } } } + ProjectionElem::Subtype(ty) => { + if !relate_types( + self.tcx, + self.param_env, + Variance::Covariant, + ty, + place_ref.ty(&self.body.local_decls, self.tcx).ty, + ) { + self.fail( + location, + format!( + "Failed subtyping {ty:#?} and {:#?}", + place_ref.ty(&self.body.local_decls, self.tcx).ty + ), + ) + } + } _ => {} } self.super_projection_elem(place_ref, elem, context, location); @@ -1088,6 +1115,7 @@ impl<'a, 'tcx> Visitor<'tcx> for TypeChecker<'a, 'tcx> { // LHS and RHS of the assignment must have the same type. let left_ty = dest.ty(&self.body.local_decls, self.tcx).ty; let right_ty = rvalue.ty(&self.body.local_decls, self.tcx); + if !self.mir_assign_valid_types(right_ty, left_ty) { self.fail( location, diff --git a/compiler/rustc_const_eval/src/util/compare_types.rs b/compiler/rustc_const_eval/src/util/compare_types.rs index 83376c8e992..265ca0c7884 100644 --- a/compiler/rustc_const_eval/src/util/compare_types.rs +++ b/compiler/rustc_const_eval/src/util/compare_types.rs @@ -5,7 +5,7 @@ use rustc_infer::infer::TyCtxtInferExt; use rustc_middle::traits::{DefiningAnchor, ObligationCause}; -use rustc_middle::ty::{ParamEnv, Ty, TyCtxt}; +use rustc_middle::ty::{ParamEnv, Ty, TyCtxt, Variance}; use rustc_trait_selection::traits::ObligationCtxt; /// Returns whether the two types are equal up to subtyping. @@ -24,16 +24,22 @@ pub fn is_equal_up_to_subtyping<'tcx>( } // Check for subtyping in either direction. - is_subtype(tcx, param_env, src, dest) || is_subtype(tcx, param_env, dest, src) + relate_types(tcx, param_env, Variance::Covariant, src, dest) + || relate_types(tcx, param_env, Variance::Covariant, dest, src) } /// Returns whether `src` is a subtype of `dest`, i.e. `src <: dest`. /// +/// When validating assignments, the variance should be `Covariant`. When checking +/// during `MirPhase` >= `MirPhase::Runtime(RuntimePhase::Initial)` variance should be `Invariant` +/// because we want to check for type equality. +/// /// This mostly ignores opaque types as it can be used in constraining contexts /// while still computing the final underlying type. -pub fn is_subtype<'tcx>( +pub fn relate_types<'tcx>( tcx: TyCtxt<'tcx>, param_env: ParamEnv<'tcx>, + variance: Variance, src: Ty<'tcx>, dest: Ty<'tcx>, ) -> bool { @@ -48,7 +54,7 @@ pub fn is_subtype<'tcx>( let cause = ObligationCause::dummy(); let src = ocx.normalize(&cause, param_env, src); let dest = ocx.normalize(&cause, param_env, dest); - match ocx.sub(&cause, param_env, src, dest) { + match ocx.relate(&cause, param_env, variance, src, dest) { Ok(()) => {} Err(_) => return false, }; diff --git a/compiler/rustc_const_eval/src/util/mod.rs b/compiler/rustc_const_eval/src/util/mod.rs index 0aef7fa469e..040b3071e6f 100644 --- a/compiler/rustc_const_eval/src/util/mod.rs +++ b/compiler/rustc_const_eval/src/util/mod.rs @@ -7,7 +7,7 @@ mod type_name; pub use self::alignment::{is_disaligned, is_within_packed}; pub use self::check_validity_requirement::check_validity_requirement; -pub use self::compare_types::{is_equal_up_to_subtyping, is_subtype}; +pub use self::compare_types::{is_equal_up_to_subtyping, relate_types}; pub use self::type_name::type_name; /// Classify whether an operator is "left-homogeneous", i.e., the LHS has the |