diff options
Diffstat (limited to 'compiler/rustc_hir_typeck/src/generator_interior')
3 files changed, 136 insertions, 60 deletions
diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs index 122ad7009..fd8ea1ad7 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/cfg_build.rs @@ -9,9 +9,10 @@ use hir::{ use rustc_data_structures::fx::{FxHashMap, FxHashSet}; use rustc_hir as hir; use rustc_index::vec::IndexVec; +use rustc_infer::infer::InferCtxt; use rustc_middle::{ hir::map::Map, - ty::{TyCtxt, TypeckResults}, + ty::{ParamEnv, TyCtxt, TypeVisitable, TypeckResults}, }; use std::mem::swap; @@ -21,20 +22,29 @@ use std::mem::swap; /// The resulting structure still needs to be iterated to a fixed point, which /// can be done with propagate_to_fixpoint in cfg_propagate. pub(super) fn build_control_flow_graph<'tcx>( - hir: Map<'tcx>, - tcx: TyCtxt<'tcx>, + infcx: &InferCtxt<'tcx>, typeck_results: &TypeckResults<'tcx>, + param_env: ParamEnv<'tcx>, consumed_borrowed_places: ConsumedAndBorrowedPlaces, body: &'tcx Body<'tcx>, num_exprs: usize, ) -> (DropRangesBuilder, FxHashSet<HirId>) { - let mut drop_range_visitor = - DropRangeVisitor::new(hir, tcx, typeck_results, consumed_borrowed_places, num_exprs); + let mut drop_range_visitor = DropRangeVisitor::new( + infcx, + typeck_results, + param_env, + consumed_borrowed_places, + num_exprs, + ); intravisit::walk_body(&mut drop_range_visitor, body); drop_range_visitor.drop_ranges.process_deferred_edges(); - if let Some(filename) = &tcx.sess.opts.unstable_opts.dump_drop_tracking_cfg { - super::cfg_visualize::write_graph_to_file(&drop_range_visitor.drop_ranges, filename, tcx); + if let Some(filename) = &infcx.tcx.sess.opts.unstable_opts.dump_drop_tracking_cfg { + super::cfg_visualize::write_graph_to_file( + &drop_range_visitor.drop_ranges, + filename, + infcx.tcx, + ); } (drop_range_visitor.drop_ranges, drop_range_visitor.places.borrowed_temporaries) @@ -82,40 +92,44 @@ pub(super) fn build_control_flow_graph<'tcx>( /// ``` struct DropRangeVisitor<'a, 'tcx> { - hir: Map<'tcx>, + typeck_results: &'a TypeckResults<'tcx>, + infcx: &'a InferCtxt<'tcx>, + param_env: ParamEnv<'tcx>, places: ConsumedAndBorrowedPlaces, drop_ranges: DropRangesBuilder, expr_index: PostOrderId, - tcx: TyCtxt<'tcx>, - typeck_results: &'a TypeckResults<'tcx>, label_stack: Vec<(Option<rustc_ast::Label>, PostOrderId)>, } impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> { fn new( - hir: Map<'tcx>, - tcx: TyCtxt<'tcx>, + infcx: &'a InferCtxt<'tcx>, typeck_results: &'a TypeckResults<'tcx>, + param_env: ParamEnv<'tcx>, places: ConsumedAndBorrowedPlaces, num_exprs: usize, ) -> Self { debug!("consumed_places: {:?}", places.consumed); let drop_ranges = DropRangesBuilder::new( places.consumed.iter().flat_map(|(_, places)| places.iter().cloned()), - hir, + infcx.tcx.hir(), num_exprs, ); Self { - hir, + infcx, + typeck_results, + param_env, places, drop_ranges, expr_index: PostOrderId::from_u32(0), - typeck_results, - tcx, label_stack: vec![], } } + fn tcx(&self) -> TyCtxt<'tcx> { + self.infcx.tcx + } + fn record_drop(&mut self, value: TrackedValue) { if self.places.borrowed.contains(&value) { debug!("not marking {:?} as dropped because it is borrowed at some point", value); @@ -137,7 +151,7 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> { .map_or(vec![], |places| places.iter().cloned().collect()); for place in places { trace!(?place, "consuming place"); - for_each_consumable(self.hir, place, |value| self.record_drop(value)); + for_each_consumable(self.tcx().hir(), place, |value| self.record_drop(value)); } } @@ -214,10 +228,15 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> { /// return. fn handle_uninhabited_return(&mut self, expr: &Expr<'tcx>) { let ty = self.typeck_results.expr_ty(expr); - let ty = self.tcx.erase_regions(ty); - let m = self.tcx.parent_module(expr.hir_id).to_def_id(); - let param_env = self.tcx.param_env(m.expect_local()); - if self.tcx.is_ty_uninhabited_from(m, ty, param_env) { + let ty = self.infcx.resolve_vars_if_possible(ty); + if ty.has_non_region_infer() { + self.tcx() + .sess + .delay_span_bug(expr.span, format!("could not resolve infer vars in `{ty}`")); + } + let ty = self.tcx().erase_regions(ty); + let m = self.tcx().parent_module(expr.hir_id).to_def_id(); + if !ty.is_inhabited_from(self.tcx(), m, self.param_env) { // This function will not return. We model this fact as an infinite loop. self.drop_ranges.add_control_edge(self.expr_index + 1, self.expr_index + 1); } @@ -238,7 +257,7 @@ impl<'a, 'tcx> DropRangeVisitor<'a, 'tcx> { destination: hir::Destination, ) -> Result<HirId, LoopIdError> { destination.target_id.map(|target| { - let node = self.hir.get(target); + let node = self.tcx().hir().get(target); match node { hir::Node::Expr(_) => target, hir::Node::Block(b) => find_last_block_expression(b), diff --git a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs index 4f3bdfbe7..2abcadcc9 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/drop_ranges/mod.rs @@ -43,9 +43,9 @@ pub fn compute_drop_ranges<'a, 'tcx>( let typeck_results = &fcx.typeck_results.borrow(); let num_exprs = fcx.tcx.region_scope_tree(def_id).body_expr_count(body.id()).unwrap_or(0); let (mut drop_ranges, borrowed_temporaries) = build_control_flow_graph( - fcx.tcx.hir(), - fcx.tcx, + &fcx, typeck_results, + fcx.param_env, consumed_borrowed_places, body, num_exprs, diff --git a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs index b7dd599cd..3b1518ff7 100644 --- a/compiler/rustc_hir_typeck/src/generator_interior/mod.rs +++ b/compiler/rustc_hir_typeck/src/generator_interior/mod.rs @@ -13,10 +13,13 @@ use rustc_hir::def_id::DefId; use rustc_hir::hir_id::HirIdSet; use rustc_hir::intravisit::{self, Visitor}; use rustc_hir::{Arm, Expr, ExprKind, Guard, HirId, Pat, PatKind}; +use rustc_infer::infer::RegionVariableOrigin; use rustc_middle::middle::region::{self, Scope, ScopeData, YieldData}; -use rustc_middle::ty::{self, RvalueScopes, Ty, TyCtxt, TypeVisitable}; +use rustc_middle::ty::fold::FnMutDelegate; +use rustc_middle::ty::{self, BoundVariableKind, RvalueScopes, Ty, TyCtxt, TypeVisitable}; use rustc_span::symbol::sym; use rustc_span::Span; +use smallvec::{smallvec, SmallVec}; mod drop_ranges; @@ -95,8 +98,8 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> { expr, scope, ty, self.expr_count, yield_data.span ); - if let Some((unresolved_type, unresolved_type_span)) = - self.fcx.unresolved_type_vars(&ty) + if let Some((unresolved_term, unresolved_type_span)) = + self.fcx.first_unresolved_const_or_ty_var(&ty) { // If unresolved type isn't a ty_var then unresolved_type_span is None let span = self @@ -105,21 +108,22 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> { // If we encounter an int/float variable, then inference fallback didn't // finish due to some other error. Don't emit spurious additional errors. - if let ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(_)) = - unresolved_type.kind() + if let Some(unresolved_ty) = unresolved_term.ty() + && let ty::Infer(ty::InferTy::IntVar(_) | ty::InferTy::FloatVar(_)) = unresolved_ty.kind() { self.fcx .tcx .sess - .delay_span_bug(span, &format!("Encountered var {:?}", unresolved_type)); + .delay_span_bug(span, &format!("Encountered var {:?}", unresolved_term)); } else { let note = format!( "the type is part of the {} because of this {}", - self.kind, yield_data.source + self.kind.descr(), + yield_data.source ); self.fcx - .need_type_info_err_in_generator(self.kind, span, unresolved_type) + .need_type_info_err_in_generator(self.kind, span, unresolved_term) .span_note(yield_data.span, &*note) .emit(); } @@ -159,7 +163,7 @@ impl<'a, 'tcx> InteriorVisitor<'a, 'tcx> { expr.map(|e| e.span) ); if let Some((unresolved_type, unresolved_type_span)) = - self.fcx.unresolved_type_vars(&ty) + self.fcx.first_unresolved_const_or_ty_var(&ty) { debug!( "remained unresolved_type = {:?}, unresolved_type_span: {:?}", @@ -211,31 +215,57 @@ pub fn resolve_interior<'a, 'tcx>( debug!("types in generator {:?}, span = {:?}", types, body.value.span); - let mut counter = 0; + // We want to deduplicate if the lifetimes are the same modulo some non-informative counter. + // So, we need to actually do two passes: first by type to anonymize (preserving information + // required for diagnostics), then a second pass over all captured types to reassign disjoint + // region indices. let mut captured_tys = FxHashSet::default(); let type_causes: Vec<_> = types .into_iter() .filter_map(|mut cause| { - // Erase regions and canonicalize late-bound regions to deduplicate as many types as we - // can. - let ty = fcx.normalize_associated_types_in(cause.span, cause.ty); - let erased = fcx.tcx.erase_regions(ty); - if captured_tys.insert(erased) { - // Replace all regions inside the generator interior with late bound regions. - // Note that each region slot in the types gets a new fresh late bound region, - // which means that none of the regions inside relate to any other, even if - // typeck had previously found constraints that would cause them to be related. - let folded = fcx.tcx.fold_regions(erased, |_, current_depth| { - let br = ty::BoundRegion { - var: ty::BoundVar::from_u32(counter), - kind: ty::BrAnon(counter), - }; - let r = fcx.tcx.mk_region(ty::ReLateBound(current_depth, br)); - counter += 1; - r - }); - - cause.ty = folded; + // Replace all regions inside the generator interior with late bound regions. + // Note that each region slot in the types gets a new fresh late bound region, + // which means that none of the regions inside relate to any other, even if + // typeck had previously found constraints that would cause them to be related. + + let mut counter = 0; + let mut mk_bound_region = |span| { + let kind = ty::BrAnon(counter, span); + let var = ty::BoundVar::from_u32(counter); + counter += 1; + ty::BoundRegion { var, kind } + }; + let ty = fcx.normalize(cause.span, cause.ty); + let ty = fcx.tcx.fold_regions(ty, |region, current_depth| { + let br = match region.kind() { + ty::ReVar(vid) => { + let origin = fcx.region_var_origin(vid); + match origin { + RegionVariableOrigin::EarlyBoundRegion(span, _) => { + mk_bound_region(Some(span)) + } + _ => mk_bound_region(None), + } + } + // FIXME: these should use `BrNamed` + ty::ReEarlyBound(region) => { + mk_bound_region(Some(fcx.tcx.def_span(region.def_id))) + } + ty::ReLateBound(_, ty::BoundRegion { kind, .. }) + | ty::ReFree(ty::FreeRegion { bound_region: kind, .. }) => match kind { + ty::BoundRegionKind::BrAnon(_, span) => mk_bound_region(span), + ty::BoundRegionKind::BrNamed(def_id, _) => { + mk_bound_region(Some(fcx.tcx.def_span(def_id))) + } + ty::BoundRegionKind::BrEnv => mk_bound_region(None), + }, + _ => mk_bound_region(None), + }; + let r = fcx.tcx.mk_region(ty::ReLateBound(current_depth, br)); + r + }); + if captured_tys.insert(ty) { + cause.ty = ty; Some(cause) } else { None @@ -243,11 +273,38 @@ pub fn resolve_interior<'a, 'tcx>( }) .collect(); + let mut bound_vars: SmallVec<[BoundVariableKind; 4]> = smallvec![]; + let mut counter = 0; + // Optimization: If there is only one captured type, then we don't actually + // need to fold and reindex (since the first type doesn't change). + let type_causes = if captured_tys.len() > 0 { + // Optimization: Use `replace_escaping_bound_vars_uncached` instead of + // `fold_regions`, since we only have late bound regions, and it skips + // types without bound regions. + fcx.tcx.replace_escaping_bound_vars_uncached( + type_causes, + FnMutDelegate { + regions: &mut |br| { + let kind = match br.kind { + ty::BrAnon(_, span) => ty::BrAnon(counter, span), + _ => br.kind, + }; + let var = ty::BoundVar::from_usize(bound_vars.len()); + bound_vars.push(ty::BoundVariableKind::Region(kind)); + counter += 1; + fcx.tcx.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BoundRegion { var, kind })) + }, + types: &mut |b| bug!("unexpected bound ty in binder: {b:?}"), + consts: &mut |b, ty| bug!("unexpected bound ct in binder: {b:?} {ty}"), + }, + ) + } else { + type_causes + }; + // Extract type components to build the witness type. let type_list = fcx.tcx.mk_type_list(type_causes.iter().map(|cause| cause.ty)); - let bound_vars = fcx.tcx.mk_bound_variable_kinds( - (0..counter).map(|i| ty::BoundVariableKind::Region(ty::BrAnon(i))), - ); + let bound_vars = fcx.tcx.mk_bound_variable_kinds(bound_vars.iter()); let witness = fcx.tcx.mk_generator_witness(ty::Binder::bind_with_vars(type_list, bound_vars.clone())); @@ -486,10 +543,10 @@ fn check_must_not_suspend_ty<'tcx>( data: SuspendCheckData<'_, 'tcx>, ) -> bool { if ty.is_unit() - // FIXME: should this check `is_ty_uninhabited_from`. This query is not available in this stage + // FIXME: should this check `Ty::is_inhabited_from`. This query is not available in this stage // of typeck (before ReVar and RePlaceholder are removed), but may remove noise, like in // `must_use` - // || fcx.tcx.is_ty_uninhabited_from(fcx.tcx.parent_module(hir_id).to_def_id(), ty, fcx.param_env) + // || !ty.is_inhabited_from(fcx.tcx, fcx.tcx.parent_module(hir_id).to_def_id(), fcx.param_env) { return false; } @@ -510,7 +567,7 @@ fn check_must_not_suspend_ty<'tcx>( let mut has_emitted = false; for &(predicate, _) in fcx.tcx.explicit_item_bounds(def) { // We only look at the `DefId`, so it is safe to skip the binder here. - if let ty::PredicateKind::Trait(ref poly_trait_predicate) = + if let ty::PredicateKind::Clause(ty::Clause::Trait(ref poly_trait_predicate)) = predicate.kind().skip_binder() { let def_id = poly_trait_predicate.trait_ref.def_id; |