diff options
Diffstat (limited to '')
| -rw-r--r-- | compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs | 104 |
1 files changed, 50 insertions, 54 deletions
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 c8a63c9c3..335992342 100644 --- a/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs +++ b/compiler/rustc_const_eval/src/transform/check_consts/qualifs.rs @@ -5,12 +5,11 @@ use rustc_errors::ErrorGuaranteed; use rustc_hir::LangItem; use rustc_infer::infer::TyCtxtInferExt; -use rustc_infer::traits::TraitEngine; +use rustc_middle::mir; use rustc_middle::mir::*; use rustc_middle::ty::{self, subst::SubstsRef, AdtDef, Ty}; -use rustc_span::DUMMY_SP; use rustc_trait_selection::traits::{ - self, ImplSource, Obligation, ObligationCause, SelectionContext, TraitEngineExt, + self, ImplSource, Obligation, ObligationCause, SelectionContext, }; use super::ConstCx; @@ -92,7 +91,7 @@ impl Qualif for HasMutInterior { } fn in_any_value_of_ty<'tcx>(cx: &ConstCx<'_, 'tcx>, ty: Ty<'tcx>) -> bool { - !ty.is_freeze(cx.tcx.at(DUMMY_SP), cx.param_env) + !ty.is_freeze(cx.tcx, cx.param_env) } fn in_adt_inherently<'tcx>( @@ -168,37 +167,28 @@ impl Qualif for NeedsNonConstDrop { }), ); - cx.tcx.infer_ctxt().enter(|infcx| { - let mut selcx = SelectionContext::new(&infcx); - let Some(impl_src) = selcx.select(&obligation).ok().flatten() else { - // If we couldn't select a const destruct candidate, then it's bad - return true; - }; - - if !matches!( - impl_src, - ImplSource::ConstDestruct(_) - | ImplSource::Param(_, ty::BoundConstness::ConstIfConst) - ) { - // If our const destruct candidate is not ConstDestruct or implied by the param env, - // then it's bad - return true; - } - - if impl_src.borrow_nested_obligations().is_empty() { - return false; - } + let infcx = cx.tcx.infer_ctxt().build(); + let mut selcx = SelectionContext::new(&infcx); + let Some(impl_src) = selcx.select(&obligation).ok().flatten() else { + // If we couldn't select a const destruct candidate, then it's bad + return true; + }; + + if !matches!( + impl_src, + ImplSource::ConstDestruct(_) | ImplSource::Param(_, ty::BoundConstness::ConstIfConst) + ) { + // If our const destruct candidate is not ConstDestruct or implied by the param env, + // then it's bad + return true; + } - // If we successfully found one, then select all of the predicates - // implied by our const drop impl. - let mut fcx = <dyn TraitEngine<'tcx>>::new(cx.tcx); - for nested in impl_src.nested_obligations() { - fcx.register_predicate_obligation(&infcx, nested); - } + if impl_src.borrow_nested_obligations().is_empty() { + return false; + } - // If we had any errors, then it's bad - !fcx.select_all_or_error(&infcx).is_empty() - }) + // If we had any errors, then it's bad + !traits::fully_solve_obligations(&infcx, impl_src.nested_obligations()).is_empty() } fn in_adt_inherently<'tcx>( @@ -316,6 +306,7 @@ where ProjectionElem::Deref | ProjectionElem::Field(_, _) + | ProjectionElem::OpaqueCast(_) | ProjectionElem::ConstantIndex { .. } | ProjectionElem::Subslice { .. } | ProjectionElem::Downcast(_, _) @@ -354,31 +345,36 @@ where }; // Check the qualifs of the value of `const` items. - if let Some(ct) = constant.literal.const_for_ty() { - if let ty::ConstKind::Unevaluated(ty::Unevaluated { def, substs: _, promoted }) = ct.kind() - { - // Use qualifs of the type for the promoted. Promoteds in MIR body should be possible - // only for `NeedsNonConstDrop` with precise drop checking. This is the only const - // check performed after the promotion. Verify that with an assertion. - assert!(promoted.is_none() || Q::ALLOW_PROMOTED); - // Don't peek inside trait associated constants. - if promoted.is_none() && cx.tcx.trait_of_item(def.did).is_none() { - let qualifs = if let Some((did, param_did)) = def.as_const_arg() { - cx.tcx.at(constant.span).mir_const_qualif_const_arg((did, param_did)) - } else { - cx.tcx.at(constant.span).mir_const_qualif(def.did) - }; - - if !Q::in_qualifs(&qualifs) { - return false; - } + // FIXME(valtrees): check whether const qualifs should behave the same + // way for type and mir constants. + let uneval = match constant.literal { + ConstantKind::Ty(ct) if matches!(ct.kind(), ty::ConstKind::Param(_)) => None, + ConstantKind::Ty(c) => bug!("expected ConstKind::Param here, found {:?}", c), + ConstantKind::Unevaluated(uv, _) => Some(uv), + ConstantKind::Val(..) => None, + }; + + if let Some(mir::UnevaluatedConst { def, substs: _, promoted }) = uneval { + // Use qualifs of the type for the promoted. Promoteds in MIR body should be possible + // only for `NeedsNonConstDrop` with precise drop checking. This is the only const + // check performed after the promotion. Verify that with an assertion. + assert!(promoted.is_none() || Q::ALLOW_PROMOTED); + + // Don't peek inside trait associated constants. + if promoted.is_none() && cx.tcx.trait_of_item(def.did).is_none() { + assert_eq!(def.const_param_did, None, "expected associated const: {def:?}"); + let qualifs = cx.tcx.at(constant.span).mir_const_qualif(def.did); - // Just in case the type is more specific than - // the definition, e.g., impl associated const - // with type parameters, take it into account. + if !Q::in_qualifs(&qualifs) { + return false; } + + // Just in case the type is more specific than + // the definition, e.g., impl associated const + // with type parameters, take it into account. } } + // Otherwise use the qualifs of the type. Q::in_any_value_of_ty(cx, constant.literal.ty()) } |