diff options
Diffstat (limited to 'compiler/rustc_trait_selection/src')
| -rw-r--r-- | compiler/rustc_trait_selection/src/errors.rs | 11 | ||||
| -rw-r--r-- | compiler/rustc_trait_selection/src/traits/vtable.rs | 175 |
2 files changed, 64 insertions, 122 deletions
diff --git a/compiler/rustc_trait_selection/src/errors.rs b/compiler/rustc_trait_selection/src/errors.rs index c8672b9dbd2..c5ab8a71c78 100644 --- a/compiler/rustc_trait_selection/src/errors.rs +++ b/compiler/rustc_trait_selection/src/errors.rs @@ -12,7 +12,7 @@ use rustc_hir::intravisit::{Visitor, VisitorExt, walk_ty}; use rustc_hir::{self as hir, AmbigArg, FnRetTy, GenericParamKind, Node}; use rustc_macros::{Diagnostic, Subdiagnostic}; use rustc_middle::ty::print::{PrintTraitRefExt as _, TraitRefPrintOnlyTraitPath}; -use rustc_middle::ty::{self, Binder, ClosureKind, FnSig, PolyTraitRef, Region, Ty, TyCtxt}; +use rustc_middle::ty::{self, Binder, ClosureKind, FnSig, Region, Ty, TyCtxt}; use rustc_span::{BytePos, Ident, Span, Symbol, kw}; use crate::error_reporting::infer::ObligationCauseAsDiagArg; @@ -23,15 +23,6 @@ use crate::fluent_generated as fluent; pub mod note_and_explain; #[derive(Diagnostic)] -#[diag(trait_selection_dump_vtable_entries)] -pub struct DumpVTableEntries<'a> { - #[primary_span] - pub span: Span, - pub trait_ref: PolyTraitRef<'a>, - pub entries: String, -} - -#[derive(Diagnostic)] #[diag(trait_selection_unable_to_construct_constant_value)] pub struct UnableToConstructConstantValue<'a> { #[primary_span] diff --git a/compiler/rustc_trait_selection/src/traits/vtable.rs b/compiler/rustc_trait_selection/src/traits/vtable.rs index b5bc8364c7b..000e6a765d3 100644 --- a/compiler/rustc_trait_selection/src/traits/vtable.rs +++ b/compiler/rustc_trait_selection/src/traits/vtable.rs @@ -2,26 +2,22 @@ use std::fmt::Debug; use std::ops::ControlFlow; use rustc_hir::def_id::DefId; -use rustc_infer::infer::at::ToTrace; -use rustc_infer::infer::{BoundRegionConversionTime, TyCtxtInferExt}; -use rustc_infer::traits::ObligationCause; use rustc_infer::traits::util::PredicateSet; use rustc_middle::bug; use rustc_middle::query::Providers; use rustc_middle::ty::{ self, GenericArgs, GenericParamDefKind, Ty, TyCtxt, TypeVisitableExt, Upcast, VtblEntry, }; -use rustc_span::{DUMMY_SP, Span, sym}; +use rustc_span::DUMMY_SP; use smallvec::{SmallVec, smallvec}; use tracing::debug; -use crate::errors::DumpVTableEntries; -use crate::traits::{ObligationCtxt, impossible_predicates, is_vtable_safe_method}; +use crate::traits::{impossible_predicates, is_vtable_safe_method}; #[derive(Clone, Debug)] pub enum VtblSegment<'tcx> { MetadataDSA, - TraitOwnEntries { trait_ref: ty::PolyTraitRef<'tcx>, emit_vptr: bool }, + TraitOwnEntries { trait_ref: ty::TraitRef<'tcx>, emit_vptr: bool }, } /// Prepare the segments for a vtable @@ -29,7 +25,7 @@ pub enum VtblSegment<'tcx> { // about our `Self` type here. pub fn prepare_vtable_segments<'tcx, T>( tcx: TyCtxt<'tcx>, - trait_ref: ty::PolyTraitRef<'tcx>, + trait_ref: ty::TraitRef<'tcx>, segment_visitor: impl FnMut(VtblSegment<'tcx>) -> ControlFlow<T>, ) -> Option<T> { prepare_vtable_segments_inner(tcx, trait_ref, segment_visitor).break_value() @@ -39,7 +35,7 @@ pub fn prepare_vtable_segments<'tcx, T>( /// such that we can use `?` in the body. fn prepare_vtable_segments_inner<'tcx, T>( tcx: TyCtxt<'tcx>, - trait_ref: ty::PolyTraitRef<'tcx>, + trait_ref: ty::TraitRef<'tcx>, mut segment_visitor: impl FnMut(VtblSegment<'tcx>) -> ControlFlow<T>, ) -> ControlFlow<T> { // The following constraints holds for the final arrangement. @@ -92,7 +88,7 @@ fn prepare_vtable_segments_inner<'tcx, T>( let mut emit_vptr_on_new_entry = false; let mut visited = PredicateSet::new(tcx); let predicate = trait_ref.upcast(tcx); - let mut stack: SmallVec<[(ty::PolyTraitRef<'tcx>, _, _); 5]> = + let mut stack: SmallVec<[(ty::TraitRef<'tcx>, _, _); 5]> = smallvec![(trait_ref, emit_vptr_on_new_entry, maybe_iter(None))]; visited.insert(predicate); @@ -125,10 +121,18 @@ fn prepare_vtable_segments_inner<'tcx, T>( let &(inner_most_trait_ref, _, _) = stack.last().unwrap(); let mut direct_super_traits_iter = tcx - .explicit_super_predicates_of(inner_most_trait_ref.def_id()) + .explicit_super_predicates_of(inner_most_trait_ref.def_id) .iter_identity_copied() .filter_map(move |(pred, _)| { - pred.instantiate_supertrait(tcx, inner_most_trait_ref).as_trait_clause() + pred.instantiate_supertrait(tcx, ty::Binder::dummy(inner_most_trait_ref)) + .as_trait_clause() + }) + .map(move |pred| { + tcx.normalize_erasing_late_bound_regions( + ty::TypingEnv::fully_monomorphized(), + pred, + ) + .trait_ref }); // Find an unvisited supertrait @@ -136,16 +140,11 @@ fn prepare_vtable_segments_inner<'tcx, T>( .find(|&super_trait| visited.insert(super_trait.upcast(tcx))) { // Push it to the stack for the next iteration of 'diving_in to pick up - Some(unvisited_super_trait) => { - // We're throwing away potential constness of super traits here. - // FIXME: handle ~const super traits - let next_super_trait = unvisited_super_trait.map_bound(|t| t.trait_ref); - stack.push(( - next_super_trait, - emit_vptr_on_new_entry, - maybe_iter(Some(direct_super_traits_iter)), - )) - } + Some(next_super_trait) => stack.push(( + next_super_trait, + emit_vptr_on_new_entry, + maybe_iter(Some(direct_super_traits_iter)), + )), // There are no more unvisited direct super traits, dive-in finished None => break 'diving_in, @@ -154,8 +153,7 @@ fn prepare_vtable_segments_inner<'tcx, T>( // emit innermost item, move to next sibling and stop there if possible, otherwise jump to outer level. while let Some((inner_most_trait_ref, emit_vptr, mut siblings)) = stack.pop() { - let has_entries = - has_own_existential_vtable_entries(tcx, inner_most_trait_ref.def_id()); + let has_entries = has_own_existential_vtable_entries(tcx, inner_most_trait_ref.def_id); segment_visitor(VtblSegment::TraitOwnEntries { trait_ref: inner_most_trait_ref, @@ -169,11 +167,6 @@ fn prepare_vtable_segments_inner<'tcx, T>( if let Some(next_inner_most_trait_ref) = siblings.find(|&sibling| visited.insert(sibling.upcast(tcx))) { - // We're throwing away potential constness of super traits here. - // FIXME: handle ~const super traits - let next_inner_most_trait_ref = - next_inner_most_trait_ref.map_bound(|t| t.trait_ref); - stack.push((next_inner_most_trait_ref, emit_vptr_on_new_entry, siblings)); // just pushed a new trait onto the stack, so we need to go through its super traits @@ -192,15 +185,6 @@ fn maybe_iter<I: Iterator>(i: Option<I>) -> impl Iterator<Item = I::Item> { i.into_iter().flatten() } -fn dump_vtable_entries<'tcx>( - tcx: TyCtxt<'tcx>, - sp: Span, - trait_ref: ty::PolyTraitRef<'tcx>, - entries: &[VtblEntry<'tcx>], -) { - tcx.dcx().emit_err(DumpVTableEntries { span: sp, trait_ref, entries: format!("{entries:#?}") }); -} - fn has_own_existential_vtable_entries(tcx: TyCtxt<'_>, trait_def_id: DefId) -> bool { own_existential_vtable_entries_iter(tcx, trait_def_id).next().is_some() } @@ -239,8 +223,15 @@ fn own_existential_vtable_entries_iter( /// that come from `trait_ref`, including its supertraits. fn vtable_entries<'tcx>( tcx: TyCtxt<'tcx>, - trait_ref: ty::PolyTraitRef<'tcx>, + trait_ref: ty::TraitRef<'tcx>, ) -> &'tcx [VtblEntry<'tcx>] { + debug_assert!(!trait_ref.has_non_region_infer() && !trait_ref.has_non_region_param()); + debug_assert_eq!( + tcx.normalize_erasing_regions(ty::TypingEnv::fully_monomorphized(), trait_ref), + trait_ref, + "vtable trait ref should be normalized" + ); + debug!("vtable_entries({:?})", trait_ref); let mut entries = vec![]; @@ -251,33 +242,26 @@ fn vtable_entries<'tcx>( entries.extend(TyCtxt::COMMON_VTABLE_ENTRIES); } VtblSegment::TraitOwnEntries { trait_ref, emit_vptr } => { - let existential_trait_ref = trait_ref - .map_bound(|trait_ref| ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref)); + let existential_trait_ref = ty::ExistentialTraitRef::erase_self_ty(tcx, trait_ref); // Lookup the shape of vtable for the trait. let own_existential_entries = - tcx.own_existential_vtable_entries(existential_trait_ref.def_id()); + tcx.own_existential_vtable_entries(existential_trait_ref.def_id); let own_entries = own_existential_entries.iter().copied().map(|def_id| { debug!("vtable_entries: trait_method={:?}", def_id); // The method may have some early-bound lifetimes; add regions for those. - let args = trait_ref.map_bound(|trait_ref| { + // FIXME: Is this normalize needed? + let args = tcx.normalize_erasing_regions( + ty::TypingEnv::fully_monomorphized(), GenericArgs::for_item(tcx, def_id, |param, _| match param.kind { GenericParamDefKind::Lifetime => tcx.lifetimes.re_erased.into(), GenericParamDefKind::Type { .. } | GenericParamDefKind::Const { .. } => { trait_ref.args[param.index as usize] } - }) - }); - - // The trait type may have higher-ranked lifetimes in it; - // erase them if they appear, so that we get the type - // at some particular call site. - let args = tcx.normalize_erasing_late_bound_regions( - ty::TypingEnv::fully_monomorphized(), - args, + }), ); // It's possible that the method relies on where-clauses that @@ -317,11 +301,6 @@ fn vtable_entries<'tcx>( let _ = prepare_vtable_segments(tcx, trait_ref, vtable_segment_callback); - if tcx.has_attr(trait_ref.def_id(), sym::rustc_dump_vtable) { - let sp = tcx.def_span(trait_ref.def_id()); - dump_vtable_entries(tcx, sp, trait_ref, &entries); - } - tcx.arena.alloc_from_iter(entries) } @@ -329,14 +308,20 @@ fn vtable_entries<'tcx>( // for `Supertrait`'s methods in the vtable of `Subtrait`. pub(crate) fn first_method_vtable_slot<'tcx>(tcx: TyCtxt<'tcx>, key: ty::TraitRef<'tcx>) -> usize { debug_assert!(!key.has_non_region_infer() && !key.has_non_region_param()); + debug_assert_eq!( + tcx.normalize_erasing_regions(ty::TypingEnv::fully_monomorphized(), key), + key, + "vtable trait ref should be normalized" + ); let ty::Dynamic(source, _, _) = *key.self_ty().kind() else { bug!(); }; - let source_principal = - source.principal().unwrap().with_self_ty(tcx, tcx.types.trait_object_dummy_self); + let source_principal = tcx.instantiate_bound_regions_with_erased( + source.principal().unwrap().with_self_ty(tcx, tcx.types.trait_object_dummy_self), + ); - let target_principal = ty::Binder::dummy(ty::ExistentialTraitRef::erase_self_ty(tcx, key)); + let target_principal = ty::ExistentialTraitRef::erase_self_ty(tcx, key); let vtable_segment_callback = { let mut vptr_offset = 0; @@ -346,17 +331,14 @@ pub(crate) fn first_method_vtable_slot<'tcx>(tcx: TyCtxt<'tcx>, key: ty::TraitRe vptr_offset += TyCtxt::COMMON_VTABLE_ENTRIES.len(); } VtblSegment::TraitOwnEntries { trait_ref: vtable_principal, emit_vptr } => { - if trait_refs_are_compatible( - tcx, - vtable_principal - .map_bound(|t| ty::ExistentialTraitRef::erase_self_ty(tcx, t)), - target_principal, - ) { + if ty::ExistentialTraitRef::erase_self_ty(tcx, vtable_principal) + == target_principal + { return ControlFlow::Break(vptr_offset); } vptr_offset += - tcx.own_existential_vtable_entries(vtable_principal.def_id()).len(); + tcx.own_existential_vtable_entries(vtable_principal.def_id).len(); if emit_vptr { vptr_offset += 1; @@ -382,20 +364,27 @@ pub(crate) fn supertrait_vtable_slot<'tcx>( ), ) -> Option<usize> { debug_assert!(!key.has_non_region_infer() && !key.has_non_region_param()); + debug_assert_eq!( + tcx.normalize_erasing_regions(ty::TypingEnv::fully_monomorphized(), key), + key, + "upcasting trait refs should be normalized" + ); + let (source, target) = key; // If the target principal is `None`, we can just return `None`. let ty::Dynamic(target, _, _) = *target.kind() else { bug!(); }; - let target_principal = target.principal()?; + let target_principal = tcx.instantiate_bound_regions_with_erased(target.principal()?); // Given that we have a target principal, it is a bug for there not to be a source principal. let ty::Dynamic(source, _, _) = *source.kind() else { bug!(); }; - let source_principal = - source.principal().unwrap().with_self_ty(tcx, tcx.types.trait_object_dummy_self); + let source_principal = tcx.instantiate_bound_regions_with_erased( + source.principal().unwrap().with_self_ty(tcx, tcx.types.trait_object_dummy_self), + ); let vtable_segment_callback = { let mut vptr_offset = 0; @@ -406,13 +395,10 @@ pub(crate) fn supertrait_vtable_slot<'tcx>( } VtblSegment::TraitOwnEntries { trait_ref: vtable_principal, emit_vptr } => { vptr_offset += - tcx.own_existential_vtable_entries(vtable_principal.def_id()).len(); - if trait_refs_are_compatible( - tcx, - vtable_principal - .map_bound(|t| ty::ExistentialTraitRef::erase_self_ty(tcx, t)), - target_principal, - ) { + tcx.own_existential_vtable_entries(vtable_principal.def_id).len(); + if ty::ExistentialTraitRef::erase_self_ty(tcx, vtable_principal) + == target_principal + { if emit_vptr { return ControlFlow::Break(Some(vptr_offset)); } else { @@ -432,41 +418,6 @@ pub(crate) fn supertrait_vtable_slot<'tcx>( prepare_vtable_segments(tcx, source_principal, vtable_segment_callback).unwrap() } -fn trait_refs_are_compatible<'tcx>( - tcx: TyCtxt<'tcx>, - hr_vtable_principal: ty::PolyExistentialTraitRef<'tcx>, - hr_target_principal: ty::PolyExistentialTraitRef<'tcx>, -) -> bool { - if hr_vtable_principal.def_id() != hr_target_principal.def_id() { - return false; - } - - let (infcx, param_env) = - tcx.infer_ctxt().build_with_typing_env(ty::TypingEnv::fully_monomorphized()); - let ocx = ObligationCtxt::new(&infcx); - let hr_source_principal = - ocx.normalize(&ObligationCause::dummy(), param_env, hr_vtable_principal); - let hr_target_principal = - ocx.normalize(&ObligationCause::dummy(), param_env, hr_target_principal); - infcx.enter_forall(hr_target_principal, |target_principal| { - let source_principal = infcx.instantiate_binder_with_fresh_vars( - DUMMY_SP, - BoundRegionConversionTime::HigherRankedType, - hr_source_principal, - ); - let Ok(()) = ocx.eq_trace( - &ObligationCause::dummy(), - param_env, - ToTrace::to_trace(&ObligationCause::dummy(), hr_target_principal, hr_source_principal), - target_principal, - source_principal, - ) else { - return false; - }; - ocx.select_all_or_error().is_empty() - }) -} - pub(super) fn provide(providers: &mut Providers) { *providers = Providers { own_existential_vtable_entries, |