diff options
Diffstat (limited to 'compiler/rustc_borrowck/src/lib.rs')
| -rw-r--r-- | compiler/rustc_borrowck/src/lib.rs | 140 |
1 files changed, 62 insertions, 78 deletions
diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs index a4b285a34..a53ea100c 100644 --- a/compiler/rustc_borrowck/src/lib.rs +++ b/compiler/rustc_borrowck/src/lib.rs @@ -20,14 +20,14 @@ extern crate tracing; use rustc_data_structures::fx::{FxIndexMap, FxIndexSet}; use rustc_data_structures::graph::dominators::Dominators; use rustc_errors::{Diagnostic, DiagnosticBuilder, DiagnosticMessage, SubdiagnosticMessage}; +use rustc_fluent_macro::fluent_messages; use rustc_hir as hir; use rustc_hir::def_id::LocalDefId; use rustc_index::bit_set::ChunkedBitSet; -use rustc_index::vec::{IndexSlice, IndexVec}; +use rustc_index::{IndexSlice, IndexVec}; use rustc_infer::infer::{ - DefiningAnchor, InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin, TyCtxtInferExt, + InferCtxt, NllRegionVariableOrigin, RegionVariableOrigin, TyCtxtInferExt, }; -use rustc_macros::fluent_messages; use rustc_middle::mir::{ traversal, Body, ClearCrossCrate, Local, Location, Mutability, NonDivergingIntrinsic, Operand, Place, PlaceElem, PlaceRef, VarDebugInfoContents, @@ -35,7 +35,8 @@ use rustc_middle::mir::{ use rustc_middle::mir::{AggregateKind, BasicBlock, BorrowCheckResult, BorrowKind}; use rustc_middle::mir::{InlineAsmOperand, Terminator, TerminatorKind}; use rustc_middle::mir::{ProjectionElem, Promoted, Rvalue, Statement, StatementKind}; -use rustc_middle::ty::query::Providers; +use rustc_middle::query::Providers; +use rustc_middle::traits::DefiningAnchor; use rustc_middle::ty::{self, CapturedPlace, ParamEnv, RegionVid, TyCtxt}; use rustc_session::lint::builtin::UNUSED_MUT; use rustc_span::{Span, Symbol}; @@ -43,7 +44,6 @@ use rustc_target::abi::FieldIdx; use either::Either; use smallvec::SmallVec; -use std::cell::OnceCell; use std::cell::RefCell; use std::collections::BTreeMap; use std::ops::Deref; @@ -62,7 +62,7 @@ use crate::session_diagnostics::VarNeedNotMut; use self::diagnostics::{AccessKind, RegionName}; use self::location::LocationTable; use self::prefixes::PrefixSet; -use facts::AllFacts; +use consumers::{BodyWithBorrowckFacts, ConsumerOptions}; use self::path_utils::*; @@ -88,6 +88,7 @@ mod session_diagnostics; mod type_check; mod universal_regions; mod used_muts; +mod util; /// A public API provided for the Rust compiler consumers. pub mod consumers; @@ -118,24 +119,12 @@ impl<'tcx> TyCtxtConsts<'tcx> { } pub fn provide(providers: &mut Providers) { - *providers = Providers { - mir_borrowck: |tcx, did| { - if let Some(def) = ty::WithOptConstParam::try_lookup(did, tcx) { - tcx.mir_borrowck_const_arg(def) - } else { - mir_borrowck(tcx, ty::WithOptConstParam::unknown(did)) - } - }, - mir_borrowck_const_arg: |tcx, (did, param_did)| { - mir_borrowck(tcx, ty::WithOptConstParam { did, const_param_did: Some(param_did) }) - }, - ..*providers - }; + *providers = Providers { mir_borrowck, ..*providers }; } -fn mir_borrowck(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> &BorrowCheckResult<'_> { +fn mir_borrowck(tcx: TyCtxt<'_>, def: LocalDefId) -> &BorrowCheckResult<'_> { let (input_body, promoted) = tcx.mir_promoted(def); - debug!("run query mir_borrowck: {}", tcx.def_path_str(def.did.to_def_id())); + debug!("run query mir_borrowck: {}", tcx.def_path_str(def)); if input_body.borrow().should_skip() { debug!("Skipping borrowck because of injected body"); @@ -149,13 +138,13 @@ fn mir_borrowck(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> &Bor return tcx.arena.alloc(result); } - let hir_owner = tcx.hir().local_def_id_to_hir_id(def.did).owner; + let hir_owner = tcx.hir().local_def_id_to_hir_id(def).owner; let infcx = tcx.infer_ctxt().with_opaque_type_inference(DefiningAnchor::Bind(hir_owner.def_id)).build(); let input_body: &Body<'_> = &input_body.borrow(); let promoted: &IndexSlice<_, _> = &promoted.borrow(); - let opt_closure_req = do_mir_borrowck(&infcx, input_body, promoted, false).0; + let opt_closure_req = do_mir_borrowck(&infcx, input_body, promoted, None).0; debug!("mir_borrowck done"); tcx.arena.alloc(opt_closure_req) @@ -163,22 +152,22 @@ fn mir_borrowck(tcx: TyCtxt<'_>, def: ty::WithOptConstParam<LocalDefId>) -> &Bor /// Perform the actual borrow checking. /// -/// If `return_body_with_facts` is true, then return the body with non-erased -/// region ids on which the borrow checking was performed together with Polonius -/// facts. -#[instrument(skip(infcx, input_body, input_promoted), fields(id=?input_body.source.with_opt_param().as_local().unwrap()), level = "debug")] +/// Use `consumer_options: None` for the default behavior of returning +/// [`BorrowCheckResult`] only. Otherwise, return [`BodyWithBorrowckFacts`] according +/// to the given [`ConsumerOptions`]. +#[instrument(skip(infcx, input_body, input_promoted), fields(id=?input_body.source.def_id()), level = "debug")] fn do_mir_borrowck<'tcx>( infcx: &InferCtxt<'tcx>, input_body: &Body<'tcx>, input_promoted: &IndexSlice<Promoted, Body<'tcx>>, - return_body_with_facts: bool, + consumer_options: Option<ConsumerOptions>, ) -> (BorrowCheckResult<'tcx>, Option<Box<BodyWithBorrowckFacts<'tcx>>>) { - let def = input_body.source.with_opt_param().as_local().unwrap(); + let def = input_body.source.def_id().expect_local(); debug!(?def); let tcx = infcx.tcx; let infcx = BorrowckInferCtxt::new(infcx); - let param_env = tcx.param_env(def.did); + let param_env = tcx.param_env(def); let mut local_names = IndexVec::from_elem(None, &input_body.local_decls); for var_debug_info in &input_body.var_debug_info { @@ -206,7 +195,7 @@ fn do_mir_borrowck<'tcx>( errors.set_tainted_by_errors(e); } let upvars: Vec<_> = tcx - .closure_captures(def.did) + .closure_captures(def) .iter() .map(|&captured_place| { let capture = captured_place.info.capture_kind; @@ -248,12 +237,10 @@ fn do_mir_borrowck<'tcx>( .iterate_to_fixpoint() .into_results_cursor(&body); - let locals_are_invalidated_at_exit = tcx.hir().body_owner_kind(def.did).is_fn_or_closure(); + let locals_are_invalidated_at_exit = tcx.hir().body_owner_kind(def).is_fn_or_closure(); let borrow_set = Rc::new(BorrowSet::build(tcx, body, locals_are_invalidated_at_exit, &mdpe.move_data)); - let use_polonius = return_body_with_facts || infcx.tcx.sess.opts.unstable_opts.polonius; - // Compute non-lexical lifetimes. let nll::NllOutput { regioncx, @@ -273,7 +260,7 @@ fn do_mir_borrowck<'tcx>( &mdpe.move_data, &borrow_set, &upvars, - use_polonius, + consumer_options, ); // Dump MIR results into a file, if that is enabled. This let us @@ -342,7 +329,6 @@ fn do_mir_borrowck<'tcx>( used_mut: Default::default(), used_mut_upvars: SmallVec::new(), borrow_set: Rc::clone(&borrow_set), - dominators: Default::default(), upvars: Vec::new(), local_names: IndexVec::from_elem(None, &promoted_body.local_decls), region_names: RefCell::default(), @@ -371,7 +357,6 @@ fn do_mir_borrowck<'tcx>( used_mut: Default::default(), used_mut_upvars: SmallVec::new(), borrow_set: Rc::clone(&borrow_set), - dominators: Default::default(), upvars, local_names, region_names: RefCell::default(), @@ -455,13 +440,16 @@ fn do_mir_borrowck<'tcx>( tainted_by_errors, }; - let body_with_facts = if return_body_with_facts { - let output_facts = mbcx.polonius_output.expect("Polonius output was not computed"); + let body_with_facts = if consumer_options.is_some() { + let output_facts = mbcx.polonius_output; Some(Box::new(BodyWithBorrowckFacts { body: body_owned, - input_facts: *polonius_input.expect("Polonius input facts were not generated"), + promoted, + borrow_set, + region_inference_context: regioncx, + location_table: polonius_input.as_ref().map(|_| location_table_owned), + input_facts: polonius_input, output_facts, - location_table: location_table_owned, })) } else { None @@ -472,22 +460,6 @@ fn do_mir_borrowck<'tcx>( (result, body_with_facts) } -/// A `Body` with information computed by the borrow checker. This struct is -/// intended to be consumed by compiler consumers. -/// -/// We need to include the MIR body here because the region identifiers must -/// match the ones in the Polonius facts. -pub struct BodyWithBorrowckFacts<'tcx> { - /// A mir body that contains region identifiers. - pub body: Body<'tcx>, - /// Polonius input facts. - pub input_facts: AllFacts, - /// Polonius output facts. - pub output_facts: Rc<self::nll::PoloniusOutput>, - /// The table that maps Polonius points to locations in the table. - pub location_table: LocationTable, -} - pub struct BorrowckInferCtxt<'cx, 'tcx> { pub(crate) infcx: &'cx InferCtxt<'tcx>, pub(crate) reg_var_to_origin: RefCell<FxIndexMap<ty::RegionVid, RegionCtxt>>, @@ -509,11 +481,11 @@ impl<'cx, 'tcx> BorrowckInferCtxt<'cx, 'tcx> { let next_region = self.infcx.next_region_var(origin); let vid = next_region.as_var(); - if cfg!(debug_assertions) && !self.inside_canonicalization_ctxt() { + if cfg!(debug_assertions) { debug!("inserting vid {:?} with origin {:?} into var_to_origin", vid, origin); let ctxt = get_ctxt_fn(); let mut var_to_origin = self.reg_var_to_origin.borrow_mut(); - var_to_origin.insert(vid, ctxt); + assert_eq!(var_to_origin.insert(vid, ctxt), None); } next_region @@ -528,14 +500,14 @@ impl<'cx, 'tcx> BorrowckInferCtxt<'cx, 'tcx> { where F: Fn() -> RegionCtxt, { - let next_region = self.infcx.next_nll_region_var(origin.clone()); + let next_region = self.infcx.next_nll_region_var(origin); let vid = next_region.as_var(); - if cfg!(debug_assertions) && !self.inside_canonicalization_ctxt() { + if cfg!(debug_assertions) { debug!("inserting vid {:?} with origin {:?} into var_to_origin", vid, origin); let ctxt = get_ctxt_fn(); let mut var_to_origin = self.reg_var_to_origin.borrow_mut(); - var_to_origin.insert(vid, ctxt); + assert_eq!(var_to_origin.insert(vid, ctxt), None); } next_region @@ -602,9 +574,6 @@ struct MirBorrowckCtxt<'cx, 'tcx> { /// The set of borrows extracted from the MIR borrow_set: Rc<BorrowSet<'tcx>>, - /// Dominators for MIR - dominators: OnceCell<Dominators<BasicBlock>>, - /// Information about upvars not necessarily preserved in types or MIR upvars: Vec<Upvar<'tcx>>, @@ -676,7 +645,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx } // Only relevant for mir typeck StatementKind::AscribeUserType(..) - // Only relevant for unsafeck + // Only relevant for liveness and unsafeck | StatementKind::PlaceMention(..) // Doesn't have any language semantics | StatementKind::Coverage(..) @@ -716,17 +685,19 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx TerminatorKind::SwitchInt { discr, targets: _ } => { self.consume_operand(loc, (discr, span), flow_state); } - TerminatorKind::Drop { place, target: _, unwind: _ } => { + TerminatorKind::Drop { place, target: _, unwind: _, replace } => { debug!( "visit_terminator_drop \ loc: {:?} term: {:?} place: {:?} span: {:?}", loc, term, place, span ); + let write_kind = + if *replace { WriteKind::Replace } else { WriteKind::StorageDeadOrDrop }; self.access_place( loc, (*place, span), - (AccessDepth::Drop, Write(WriteKind::StorageDeadOrDrop)), + (AccessDepth::Drop, Write(write_kind)), LocalMutationIsAllowed::Yes, flow_state, ); @@ -749,7 +720,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx TerminatorKind::Assert { cond, expected: _, msg, target: _, unwind: _ } => { self.consume_operand(loc, (cond, span), flow_state); use rustc_middle::mir::AssertKind; - if let AssertKind::BoundsCheck { len, index } = msg { + if let AssertKind::BoundsCheck { len, index } = &**msg { self.consume_operand(loc, (len, span), flow_state); self.consume_operand(loc, (index, span), flow_state); } @@ -916,6 +887,7 @@ enum ReadKind { #[derive(Copy, Clone, PartialEq, Eq, Debug)] enum WriteKind { StorageDeadOrDrop, + Replace, MutableBorrow(BorrowKind), Mutate, Move, @@ -946,6 +918,7 @@ enum InitializationRequiringAction { PartialAssignment, } +#[derive(Debug)] struct RootPlace<'tcx> { place_local: Local, place_projection: &'tcx [PlaceElem<'tcx>], @@ -1162,13 +1135,21 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { this.buffer_error(err); } WriteKind::StorageDeadOrDrop => this - .report_storage_dead_or_drop_of_borrowed(location, place_span, borrow), + .report_borrowed_value_does_not_live_long_enough( + location, + borrow, + place_span, + Some(WriteKind::StorageDeadOrDrop), + ), WriteKind::Mutate => { this.report_illegal_mutation_of_borrowed(location, place_span, borrow) } WriteKind::Move => { this.report_move_out_while_borrowed(location, place_span, borrow) } + WriteKind::Replace => { + this.report_illegal_mutation_of_borrowed(location, place_span, borrow) + } } Control::Break } @@ -1859,11 +1840,6 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { // is allowed, remove this match arm. ty::Adt(..) | ty::Tuple(..) => { check_parent_of_field(self, location, place_base, span, flow_state); - - // rust-lang/rust#21232, #54499, #54986: during period where we reject - // partial initialization, do not complain about unnecessary `mut` on - // an attempt to do a partial initialization. - self.used_mut.insert(place.local); } _ => {} @@ -1951,6 +1927,11 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { (prefix, base, span), mpi, ); + + // rust-lang/rust#21232, #54499, #54986: during period where we reject + // partial initialization, do not complain about unnecessary `mut` on + // an attempt to do a partial initialization. + this.used_mut.insert(base.local); } } } @@ -2012,12 +1993,14 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { Reservation( WriteKind::Move + | WriteKind::Replace | WriteKind::StorageDeadOrDrop | WriteKind::MutableBorrow(BorrowKind::Shared) | WriteKind::MutableBorrow(BorrowKind::Shallow), ) | Write( WriteKind::Move + | WriteKind::Replace | WriteKind::StorageDeadOrDrop | WriteKind::MutableBorrow(BorrowKind::Shared) | WriteKind::MutableBorrow(BorrowKind::Shallow), @@ -2032,7 +2015,7 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { // been emitted (#52262). self.infcx.tcx.sess.delay_span_bug( span, - &format!( + format!( "Accessing `{:?}` with the kind `{:?}` shouldn't be possible", place, kind, ), @@ -2279,7 +2262,8 @@ impl<'cx, 'tcx> MirBorrowckCtxt<'cx, 'tcx> { } fn dominators(&self) -> &Dominators<BasicBlock> { - self.dominators.get_or_init(|| self.body.basic_blocks.dominators()) + // `BasicBlocks` computes dominators on-demand and caches them. + self.body.basic_blocks.dominators() } } @@ -2393,7 +2377,7 @@ mod error { } for (_, (mut diag, count)) in std::mem::take(&mut self.errors.buffered_mut_errors) { if count > 10 { - diag.note(&format!("...and {} other attempted mutable borrows", count - 10)); + diag.note(format!("...and {} other attempted mutable borrows", count - 10)); } diag.buffer(&mut self.errors.buffered); } |