From 3350edf8fdcab10b60bf8173bd3b1551f567cd44 Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Thu, 31 Oct 2024 11:02:22 +1100 Subject: [PATCH 1/2] Replace `BorrowckResults` with `Borrowck`. The results of most analyses end up in a `Results<'tcx, A>`, where `A` is the analysis. It's then possible to traverse the results via a `ResultsVisitor`, which relies on the `ResultsVisitable` trait. (That trait ends up using the same `apply_*` methods that were used when computing the analysis, albeit indirectly.) This pattern of "compute analysis results, then visit them" is common. But there is one exception. For borrow checking we compute three separate analyses (`Borrows`, `MaybeUninitializedPlaces`, and `EverInitializedPlaces`), combine them into a single `BorrowckResults`, and then do a single visit of that `BorrowckResults` with `MirBorrowckResults`. `BorrowckResults` is just different enough from `Results` that it requires the existence of `ResultsVisitable`, which abstracts over the traversal differences between `Results` and `BorrowckResults`. This commit changes things by introducing `Borrowck` and bundling the three borrowck analysis results into a standard `Results` instead of the exceptional `BorrowckResults`. Once that's done, the results can be visited like any other analysis results. `BorrowckResults` is removed, as is `impl ResultsVisitable for BorrowckResults`. (It's instructive to see how similar the added `impl Analysis for Borrowck` is to the removed `impl ResultsVisitable for BorrowckResults`. They're both doing exactly the same things.) Overall this increases the number of lines of code and might not seem like a win. But it enables the removal of `ResultsVisitable` in the next commit, which results in many simplifications. --- compiler/rustc_borrowck/src/dataflow.rs | 160 +++++++++++++----- compiler/rustc_borrowck/src/lib.rs | 79 +++++---- .../rustc_mir_dataflow/src/framework/mod.rs | 2 +- .../src/framework/results.rs | 4 +- compiler/rustc_mir_dataflow/src/lib.rs | 6 +- 5 files changed, 174 insertions(+), 77 deletions(-) diff --git a/compiler/rustc_borrowck/src/dataflow.rs b/compiler/rustc_borrowck/src/dataflow.rs index d832decc1708f..7adc7a8863e42 100644 --- a/compiler/rustc_borrowck/src/dataflow.rs +++ b/compiler/rustc_borrowck/src/dataflow.rs @@ -1,93 +1,171 @@ +use std::fmt; + use rustc_data_structures::fx::FxIndexMap; use rustc_data_structures::graph; use rustc_index::bit_set::BitSet; -use rustc_middle::mir::{self, BasicBlock, Body, Location, Place, TerminatorEdges}; +use rustc_middle::mir::{ + self, BasicBlock, Body, CallReturnPlaces, Location, Place, TerminatorEdges, +}; use rustc_middle::ty::{RegionVid, TyCtxt}; use rustc_mir_dataflow::fmt::DebugWithContext; use rustc_mir_dataflow::impls::{EverInitializedPlaces, MaybeUninitializedPlaces}; -use rustc_mir_dataflow::{Analysis, Forward, GenKill, Results, ResultsVisitable}; +use rustc_mir_dataflow::{Analysis, GenKill, JoinSemiLattice, SwitchIntEdgeEffects}; use tracing::debug; use crate::{BorrowSet, PlaceConflictBias, PlaceExt, RegionInferenceContext, places_conflict}; -/// The results of the dataflow analyses used by the borrow checker. -pub(crate) struct BorrowckResults<'a, 'tcx> { - pub(crate) borrows: Results<'tcx, Borrows<'a, 'tcx>>, - pub(crate) uninits: Results<'tcx, MaybeUninitializedPlaces<'a, 'tcx>>, - pub(crate) ever_inits: Results<'tcx, EverInitializedPlaces<'a, 'tcx>>, -} - -/// The transient state of the dataflow analyses used by the borrow checker. -#[derive(Debug)] -pub(crate) struct BorrowckDomain<'a, 'tcx> { - pub(crate) borrows: as Analysis<'tcx>>::Domain, - pub(crate) uninits: as Analysis<'tcx>>::Domain, - pub(crate) ever_inits: as Analysis<'tcx>>::Domain, +// This analysis is different to most others. Its results aren't computed with +// `iterate_to_fixpoint`, but are instead composed from the results of three sub-analyses that are +// computed individually with `iterate_to_fixpoint`. +pub(crate) struct Borrowck<'a, 'tcx> { + pub(crate) borrows: Borrows<'a, 'tcx>, + pub(crate) uninits: MaybeUninitializedPlaces<'a, 'tcx>, + pub(crate) ever_inits: EverInitializedPlaces<'a, 'tcx>, } -impl<'a, 'tcx> ResultsVisitable<'tcx> for BorrowckResults<'a, 'tcx> { - type Direction = Forward; +impl<'a, 'tcx> Analysis<'tcx> for Borrowck<'a, 'tcx> { type Domain = BorrowckDomain<'a, 'tcx>; + const NAME: &'static str = "borrowck"; + fn bottom_value(&self, body: &mir::Body<'tcx>) -> Self::Domain { BorrowckDomain { - borrows: self.borrows.analysis.bottom_value(body), - uninits: self.uninits.analysis.bottom_value(body), - ever_inits: self.ever_inits.analysis.bottom_value(body), + borrows: self.borrows.bottom_value(body), + uninits: self.uninits.bottom_value(body), + ever_inits: self.ever_inits.bottom_value(body), } } - fn reset_to_block_entry(&self, state: &mut Self::Domain, block: BasicBlock) { - state.borrows.clone_from(self.borrows.entry_set_for_block(block)); - state.uninits.clone_from(self.uninits.entry_set_for_block(block)); - state.ever_inits.clone_from(self.ever_inits.entry_set_for_block(block)); + fn initialize_start_block(&self, _body: &mir::Body<'tcx>, _state: &mut Self::Domain) { + // This is only reachable from `iterate_to_fixpoint`, which this analysis doesn't use. + unreachable!(); } - fn reconstruct_before_statement_effect( + fn apply_before_statement_effect( &mut self, state: &mut Self::Domain, stmt: &mir::Statement<'tcx>, loc: Location, ) { - self.borrows.analysis.apply_before_statement_effect(&mut state.borrows, stmt, loc); - self.uninits.analysis.apply_before_statement_effect(&mut state.uninits, stmt, loc); - self.ever_inits.analysis.apply_before_statement_effect(&mut state.ever_inits, stmt, loc); + self.borrows.apply_before_statement_effect(&mut state.borrows, stmt, loc); + self.uninits.apply_before_statement_effect(&mut state.uninits, stmt, loc); + self.ever_inits.apply_before_statement_effect(&mut state.ever_inits, stmt, loc); } - fn reconstruct_statement_effect( + fn apply_statement_effect( &mut self, state: &mut Self::Domain, stmt: &mir::Statement<'tcx>, loc: Location, ) { - self.borrows.analysis.apply_statement_effect(&mut state.borrows, stmt, loc); - self.uninits.analysis.apply_statement_effect(&mut state.uninits, stmt, loc); - self.ever_inits.analysis.apply_statement_effect(&mut state.ever_inits, stmt, loc); + self.borrows.apply_statement_effect(&mut state.borrows, stmt, loc); + self.uninits.apply_statement_effect(&mut state.uninits, stmt, loc); + self.ever_inits.apply_statement_effect(&mut state.ever_inits, stmt, loc); } - fn reconstruct_before_terminator_effect( + fn apply_before_terminator_effect( &mut self, state: &mut Self::Domain, term: &mir::Terminator<'tcx>, loc: Location, ) { - self.borrows.analysis.apply_before_terminator_effect(&mut state.borrows, term, loc); - self.uninits.analysis.apply_before_terminator_effect(&mut state.uninits, term, loc); - self.ever_inits.analysis.apply_before_terminator_effect(&mut state.ever_inits, term, loc); + self.borrows.apply_before_terminator_effect(&mut state.borrows, term, loc); + self.uninits.apply_before_terminator_effect(&mut state.uninits, term, loc); + self.ever_inits.apply_before_terminator_effect(&mut state.ever_inits, term, loc); } - fn reconstruct_terminator_effect( + fn apply_terminator_effect<'mir>( &mut self, state: &mut Self::Domain, - term: &mir::Terminator<'tcx>, + term: &'mir mir::Terminator<'tcx>, loc: Location, + ) -> TerminatorEdges<'mir, 'tcx> { + self.borrows.apply_terminator_effect(&mut state.borrows, term, loc); + self.uninits.apply_terminator_effect(&mut state.uninits, term, loc); + self.ever_inits.apply_terminator_effect(&mut state.ever_inits, term, loc); + + // This return value doesn't matter. It's only used by `iterate_to_fixpoint`, which this + // analysis doesn't use. + TerminatorEdges::None + } + + fn apply_call_return_effect( + &mut self, + _state: &mut Self::Domain, + _block: BasicBlock, + _return_places: CallReturnPlaces<'_, 'tcx>, + ) { + // This is only reachable from `iterate_to_fixpoint`, which this analysis doesn't use. + unreachable!(); + } + + fn apply_switch_int_edge_effects( + &mut self, + _block: BasicBlock, + _discr: &mir::Operand<'tcx>, + _apply_edge_effects: &mut impl SwitchIntEdgeEffects, ) { - self.borrows.analysis.apply_terminator_effect(&mut state.borrows, term, loc); - self.uninits.analysis.apply_terminator_effect(&mut state.uninits, term, loc); - self.ever_inits.analysis.apply_terminator_effect(&mut state.ever_inits, term, loc); + // This is only reachable from `iterate_to_fixpoint`, which this analysis doesn't use. + unreachable!(); } } +impl JoinSemiLattice for BorrowckDomain<'_, '_> { + fn join(&mut self, _other: &Self) -> bool { + // This is only reachable from `iterate_to_fixpoint`, which this analysis doesn't use. + unreachable!(); + } +} + +impl<'tcx, C> DebugWithContext for BorrowckDomain<'_, 'tcx> +where + C: rustc_mir_dataflow::move_paths::HasMoveData<'tcx>, +{ + fn fmt_with(&self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result { + f.write_str("borrows: ")?; + self.borrows.fmt_with(ctxt, f)?; + f.write_str(" uninits: ")?; + self.uninits.fmt_with(ctxt, f)?; + f.write_str(" ever_inits: ")?; + self.ever_inits.fmt_with(ctxt, f)?; + Ok(()) + } + + fn fmt_diff_with(&self, old: &Self, ctxt: &C, f: &mut fmt::Formatter<'_>) -> fmt::Result { + if self == old { + return Ok(()); + } + + if self.borrows != old.borrows { + f.write_str("borrows: ")?; + self.borrows.fmt_diff_with(&old.borrows, ctxt, f)?; + f.write_str("\n")?; + } + + if self.uninits != old.uninits { + f.write_str("uninits: ")?; + self.uninits.fmt_diff_with(&old.uninits, ctxt, f)?; + f.write_str("\n")?; + } + + if self.ever_inits != old.ever_inits { + f.write_str("ever_inits: ")?; + self.ever_inits.fmt_diff_with(&old.ever_inits, ctxt, f)?; + f.write_str("\n")?; + } + + Ok(()) + } +} + +/// The transient state of the dataflow analyses used by the borrow checker. +#[derive(Clone, Debug, PartialEq, Eq)] +pub(crate) struct BorrowckDomain<'a, 'tcx> { + pub(crate) borrows: as Analysis<'tcx>>::Domain, + pub(crate) uninits: as Analysis<'tcx>>::Domain, + pub(crate) ever_inits: as Analysis<'tcx>>::Domain, +} + rustc_index::newtype_index! { #[orderable] #[debug_format = "bw{}"] diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs index 657e6e0907ca5..817d407c38cea 100644 --- a/compiler/rustc_borrowck/src/lib.rs +++ b/compiler/rustc_borrowck/src/lib.rs @@ -36,13 +36,13 @@ use rustc_middle::mir::*; use rustc_middle::query::Providers; use rustc_middle::ty::{self, ParamEnv, RegionVid, TyCtxt, TypingMode}; use rustc_middle::{bug, span_bug}; -use rustc_mir_dataflow::Analysis; use rustc_mir_dataflow::impls::{ EverInitializedPlaces, MaybeInitializedPlaces, MaybeUninitializedPlaces, }; use rustc_mir_dataflow::move_paths::{ InitIndex, InitLocation, LookupResult, MoveData, MoveOutIndex, MovePathIndex, }; +use rustc_mir_dataflow::{Analysis, EntrySets, Results}; use rustc_session::lint::builtin::UNUSED_MUT; use rustc_span::{Span, Symbol}; use smallvec::SmallVec; @@ -50,7 +50,7 @@ use tracing::{debug, instrument}; use crate::borrow_set::{BorrowData, BorrowSet}; use crate::consumers::{BodyWithBorrowckFacts, ConsumerOptions}; -use crate::dataflow::{BorrowIndex, BorrowckDomain, BorrowckResults, Borrows}; +use crate::dataflow::{BorrowIndex, Borrowck, BorrowckDomain, Borrows}; use crate::diagnostics::{AccessKind, IllegalMoveOriginKind, MoveError, RegionName}; use crate::location::LocationTable; use crate::nll::PoloniusOutput; @@ -221,6 +221,10 @@ fn do_mir_borrowck<'tcx>( consumer_options, ); + // `flow_inits` is large, so we drop it as soon as possible. This reduces + // peak memory usage significantly on some benchmarks. + drop(flow_inits); + // Dump MIR results into a file, if that is enabled. This let us // write unit-tests, as well as helping with debugging. nll::dump_nll_mir(&infcx, body, ®ioncx, &opt_closure_req, &borrow_set); @@ -229,27 +233,6 @@ fn do_mir_borrowck<'tcx>( // information. nll::dump_annotation(&infcx, body, ®ioncx, &opt_closure_req, &opaque_type_values, diags); - // The various `flow_*` structures can be large. We drop `flow_inits` here - // so it doesn't overlap with the others below. This reduces peak memory - // usage significantly on some benchmarks. - drop(flow_inits); - - let flow_borrows = Borrows::new(tcx, body, ®ioncx, &borrow_set).iterate_to_fixpoint( - tcx, - body, - Some("borrowck"), - ); - let flow_uninits = MaybeUninitializedPlaces::new(tcx, body, &move_data).iterate_to_fixpoint( - tcx, - body, - Some("borrowck"), - ); - let flow_ever_inits = EverInitializedPlaces::new(body, &move_data).iterate_to_fixpoint( - tcx, - body, - Some("borrowck"), - ); - let movable_coroutine = // The first argument is the coroutine type passed by value if let Some(local) = body.local_decls.raw.get(1) @@ -334,16 +317,11 @@ fn do_mir_borrowck<'tcx>( // Compute and report region errors, if any. mbcx.report_region_errors(nll_errors); - let mut results = BorrowckResults { - ever_inits: flow_ever_inits, - uninits: flow_uninits, - borrows: flow_borrows, - }; - + let mut flow_results = get_flow_results(tcx, body, &move_data, &borrow_set, ®ioncx); rustc_mir_dataflow::visit_results( body, traversal::reverse_postorder(body).map(|(bb, _)| bb), - &mut results, + &mut flow_results, &mut mbcx, ); @@ -426,6 +404,47 @@ fn do_mir_borrowck<'tcx>( (result, body_with_facts) } +fn get_flow_results<'a, 'tcx>( + tcx: TyCtxt<'tcx>, + body: &'a Body<'tcx>, + move_data: &'a MoveData<'tcx>, + borrow_set: &'a BorrowSet<'tcx>, + regioncx: &RegionInferenceContext<'tcx>, +) -> Results<'tcx, Borrowck<'a, 'tcx>> { + // We compute these three analyses individually, but them combine them into + // a single results so that `mbcx` can visit them all together. + let borrows = Borrows::new(tcx, body, regioncx, borrow_set).iterate_to_fixpoint( + tcx, + body, + Some("borrowck"), + ); + let uninits = MaybeUninitializedPlaces::new(tcx, body, move_data).iterate_to_fixpoint( + tcx, + body, + Some("borrowck"), + ); + let ever_inits = EverInitializedPlaces::new(body, move_data).iterate_to_fixpoint( + tcx, + body, + Some("borrowck"), + ); + + let analysis = Borrowck { + borrows: borrows.analysis, + uninits: uninits.analysis, + ever_inits: ever_inits.analysis, + }; + + assert_eq!(borrows.entry_sets.len(), uninits.entry_sets.len()); + assert_eq!(borrows.entry_sets.len(), ever_inits.entry_sets.len()); + let entry_sets: EntrySets<'_, Borrowck<'_, '_>> = + itertools::izip!(borrows.entry_sets, uninits.entry_sets, ever_inits.entry_sets) + .map(|(borrows, uninits, ever_inits)| BorrowckDomain { borrows, uninits, ever_inits }) + .collect(); + + Results { analysis, entry_sets } +} + pub(crate) struct BorrowckInferCtxt<'tcx> { pub(crate) infcx: InferCtxt<'tcx>, pub(crate) reg_var_to_origin: RefCell>, diff --git a/compiler/rustc_mir_dataflow/src/framework/mod.rs b/compiler/rustc_mir_dataflow/src/framework/mod.rs index 8f81da8bb0499..4ad681935285d 100644 --- a/compiler/rustc_mir_dataflow/src/framework/mod.rs +++ b/compiler/rustc_mir_dataflow/src/framework/mod.rs @@ -55,7 +55,7 @@ mod visitor; pub use self::cursor::ResultsCursor; pub use self::direction::{Backward, Direction, Forward}; pub use self::lattice::{JoinSemiLattice, MaybeReachable}; -pub use self::results::Results; +pub use self::results::{EntrySets, Results}; pub use self::visitor::{ResultsVisitable, ResultsVisitor, visit_results}; /// Analysis domains are all bitsets of various kinds. This trait holds diff --git a/compiler/rustc_mir_dataflow/src/framework/results.rs b/compiler/rustc_mir_dataflow/src/framework/results.rs index 366fcbf33ba3c..2269c4ec22696 100644 --- a/compiler/rustc_mir_dataflow/src/framework/results.rs +++ b/compiler/rustc_mir_dataflow/src/framework/results.rs @@ -18,7 +18,7 @@ use crate::errors::{ DuplicateValuesFor, PathMustEndInFilename, RequiresAnArgument, UnknownFormatter, }; -type EntrySets<'tcx, A> = IndexVec>::Domain>; +pub type EntrySets<'tcx, A> = IndexVec>::Domain>; /// A dataflow analysis that has converged to fixpoint. #[derive(Clone)] @@ -27,7 +27,7 @@ where A: Analysis<'tcx>, { pub analysis: A, - pub(super) entry_sets: EntrySets<'tcx, A>, + pub entry_sets: EntrySets<'tcx, A>, } impl<'tcx, A> Results<'tcx, A> diff --git a/compiler/rustc_mir_dataflow/src/lib.rs b/compiler/rustc_mir_dataflow/src/lib.rs index b404e3bfb72c3..8ebe7d593094e 100644 --- a/compiler/rustc_mir_dataflow/src/lib.rs +++ b/compiler/rustc_mir_dataflow/src/lib.rs @@ -18,9 +18,9 @@ pub use self::drop_flag_effects::{ move_path_children_matching, on_all_children_bits, on_lookup_result_bits, }; pub use self::framework::{ - Analysis, Backward, Direction, Forward, GenKill, JoinSemiLattice, MaybeReachable, Results, - ResultsCursor, ResultsVisitable, ResultsVisitor, SwitchIntEdgeEffects, fmt, graphviz, lattice, - visit_results, + Analysis, Backward, Direction, EntrySets, Forward, GenKill, JoinSemiLattice, MaybeReachable, + Results, ResultsCursor, ResultsVisitable, ResultsVisitor, SwitchIntEdgeEffects, fmt, graphviz, + lattice, visit_results, }; use self::move_paths::MoveData; From c904c6aaffa10f92e8f203f69bd8b87b0b0f4353 Mon Sep 17 00:00:00 2001 From: Nicholas Nethercote Date: Thu, 31 Oct 2024 12:33:12 +1100 Subject: [PATCH 2/2] Remove `ResultsVisitable`. Now that `Results` is the only impl of `ResultsVisitable`, the trait can be removed. This simplifies things by removining unnecessary layers of indirection and abstraction. - `ResultsVisitor` is simpler. - Its type parameter changes from `R` (an analysis result) to the simpler `A` (an analysis). - It no longer needs the `Domain` associated type, because it can use `A::Domain`. - Occurrences of `R` become `Results<'tcx, A>`, because there is now only one kind of analysis results. - `save_as_intervals` also changes type parameter from `R` to `A`. - The `results.reconstruct_*` method calls are replaced with `results.analysis.apply_*` method calls, which are equivalent. - `Direction::visit_results_in_block` is simpler, with a single generic param (`A`) instead of two (`D` and `R`/`F`, with a bound connecting them). Likewise for `visit_results`. - The `ResultsVisitor` impls for `MirBorrowCtxt` and `StorageConflictVisitor` are now specific about the type of the analysis results they work with. They both used to have a type param `R` but they weren't genuinely generic. In both cases there was only a single results type that made sense to instantiate them with. --- compiler/rustc_borrowck/src/lib.rs | 16 +- .../src/framework/direction.rs | 56 +++---- .../src/framework/graphviz.rs | 16 +- .../rustc_mir_dataflow/src/framework/mod.rs | 2 +- .../src/framework/results.rs | 4 +- .../src/framework/visitor.rs | 143 +++--------------- compiler/rustc_mir_dataflow/src/lib.rs | 4 +- compiler/rustc_mir_dataflow/src/points.rs | 21 ++- compiler/rustc_mir_transform/src/coroutine.rs | 18 +-- .../src/dataflow_const_prop.rs | 12 +- 10 files changed, 91 insertions(+), 201 deletions(-) diff --git a/compiler/rustc_borrowck/src/lib.rs b/compiler/rustc_borrowck/src/lib.rs index 817d407c38cea..7eaf265d41016 100644 --- a/compiler/rustc_borrowck/src/lib.rs +++ b/compiler/rustc_borrowck/src/lib.rs @@ -42,7 +42,7 @@ use rustc_mir_dataflow::impls::{ use rustc_mir_dataflow::move_paths::{ InitIndex, InitLocation, LookupResult, MoveData, MoveOutIndex, MovePathIndex, }; -use rustc_mir_dataflow::{Analysis, EntrySets, Results}; +use rustc_mir_dataflow::{Analysis, EntrySets, Results, ResultsVisitor, visit_results}; use rustc_session::lint::builtin::UNUSED_MUT; use rustc_span::{Span, Symbol}; use smallvec::SmallVec; @@ -318,7 +318,7 @@ fn do_mir_borrowck<'tcx>( mbcx.report_region_errors(nll_errors); let mut flow_results = get_flow_results(tcx, body, &move_data, &borrow_set, ®ioncx); - rustc_mir_dataflow::visit_results( + visit_results( body, traversal::reverse_postorder(body).map(|(bb, _)| bb), &mut flow_results, @@ -607,14 +607,10 @@ struct MirBorrowckCtxt<'a, 'infcx, 'tcx> { // 2. loans made in overlapping scopes do not conflict // 3. assignments do not affect things loaned out as immutable // 4. moves do not affect things loaned out in any way -impl<'a, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'a, 'tcx, R> - for MirBorrowckCtxt<'a, '_, 'tcx> -{ - type Domain = BorrowckDomain<'a, 'tcx>; - +impl<'a, 'tcx> ResultsVisitor<'a, 'tcx, Borrowck<'a, 'tcx>> for MirBorrowckCtxt<'a, '_, 'tcx> { fn visit_statement_before_primary_effect( &mut self, - _results: &mut R, + _results: &mut Results<'tcx, Borrowck<'a, 'tcx>>, state: &BorrowckDomain<'a, 'tcx>, stmt: &'a Statement<'tcx>, location: Location, @@ -686,7 +682,7 @@ impl<'a, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'a, 'tcx, R> fn visit_terminator_before_primary_effect( &mut self, - _results: &mut R, + _results: &mut Results<'tcx, Borrowck<'a, 'tcx>>, state: &BorrowckDomain<'a, 'tcx>, term: &'a Terminator<'tcx>, loc: Location, @@ -799,7 +795,7 @@ impl<'a, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'a, 'tcx, R> fn visit_terminator_after_primary_effect( &mut self, - _results: &mut R, + _results: &mut Results<'tcx, Borrowck<'a, 'tcx>>, state: &BorrowckDomain<'a, 'tcx>, term: &'a Terminator<'tcx>, loc: Location, diff --git a/compiler/rustc_mir_dataflow/src/framework/direction.rs b/compiler/rustc_mir_dataflow/src/framework/direction.rs index 3e01f0512c46f..9a5cf9d4e84ff 100644 --- a/compiler/rustc_mir_dataflow/src/framework/direction.rs +++ b/compiler/rustc_mir_dataflow/src/framework/direction.rs @@ -4,8 +4,8 @@ use rustc_middle::mir::{ self, BasicBlock, CallReturnPlaces, Location, SwitchTargets, TerminatorEdges, }; -use super::visitor::{ResultsVisitable, ResultsVisitor}; -use super::{Analysis, Effect, EffectIndex, SwitchIntTarget}; +use super::visitor::ResultsVisitor; +use super::{Analysis, Effect, EffectIndex, Results, SwitchIntTarget}; pub trait Direction { const IS_FORWARD: bool; @@ -33,14 +33,14 @@ pub trait Direction { where A: Analysis<'tcx>; - fn visit_results_in_block<'mir, 'tcx, D, R>( - state: &mut D, + fn visit_results_in_block<'mir, 'tcx, A>( + state: &mut A::Domain, block: BasicBlock, block_data: &'mir mir::BasicBlockData<'tcx>, - results: &mut R, - vis: &mut impl ResultsVisitor<'mir, 'tcx, R, Domain = D>, + results: &mut Results<'tcx, A>, + vis: &mut impl ResultsVisitor<'mir, 'tcx, A>, ) where - R: ResultsVisitable<'tcx, Domain = D>; + A: Analysis<'tcx>; fn join_state_into_successors_of<'tcx, A>( analysis: &mut A, @@ -53,7 +53,7 @@ pub trait Direction { A: Analysis<'tcx>; } -/// Dataflow that runs from the exit of a block (the terminator), to its entry (the first statement). +/// Dataflow that runs from the exit of a block (terminator), to its entry (the first statement). pub struct Backward; impl Direction for Backward { @@ -157,32 +157,32 @@ impl Direction for Backward { analysis.apply_statement_effect(state, statement, location); } - fn visit_results_in_block<'mir, 'tcx, D, R>( - state: &mut D, + fn visit_results_in_block<'mir, 'tcx, A>( + state: &mut A::Domain, block: BasicBlock, block_data: &'mir mir::BasicBlockData<'tcx>, - results: &mut R, - vis: &mut impl ResultsVisitor<'mir, 'tcx, R, Domain = D>, + results: &mut Results<'tcx, A>, + vis: &mut impl ResultsVisitor<'mir, 'tcx, A>, ) where - R: ResultsVisitable<'tcx, Domain = D>, + A: Analysis<'tcx>, { - results.reset_to_block_entry(state, block); + state.clone_from(results.entry_set_for_block(block)); vis.visit_block_end(state); // Terminator let loc = Location { block, statement_index: block_data.statements.len() }; let term = block_data.terminator(); - results.reconstruct_before_terminator_effect(state, term, loc); + results.analysis.apply_before_terminator_effect(state, term, loc); vis.visit_terminator_before_primary_effect(results, state, term, loc); - results.reconstruct_terminator_effect(state, term, loc); + results.analysis.apply_terminator_effect(state, term, loc); vis.visit_terminator_after_primary_effect(results, state, term, loc); for (statement_index, stmt) in block_data.statements.iter().enumerate().rev() { let loc = Location { block, statement_index }; - results.reconstruct_before_statement_effect(state, stmt, loc); + results.analysis.apply_before_statement_effect(state, stmt, loc); vis.visit_statement_before_primary_effect(results, state, stmt, loc); - results.reconstruct_statement_effect(state, stmt, loc); + results.analysis.apply_statement_effect(state, stmt, loc); vis.visit_statement_after_primary_effect(results, state, stmt, loc); } @@ -389,32 +389,32 @@ impl Direction for Forward { } } - fn visit_results_in_block<'mir, 'tcx, F, R>( - state: &mut F, + fn visit_results_in_block<'mir, 'tcx, A>( + state: &mut A::Domain, block: BasicBlock, block_data: &'mir mir::BasicBlockData<'tcx>, - results: &mut R, - vis: &mut impl ResultsVisitor<'mir, 'tcx, R, Domain = F>, + results: &mut Results<'tcx, A>, + vis: &mut impl ResultsVisitor<'mir, 'tcx, A>, ) where - R: ResultsVisitable<'tcx, Domain = F>, + A: Analysis<'tcx>, { - results.reset_to_block_entry(state, block); + state.clone_from(results.entry_set_for_block(block)); vis.visit_block_start(state); for (statement_index, stmt) in block_data.statements.iter().enumerate() { let loc = Location { block, statement_index }; - results.reconstruct_before_statement_effect(state, stmt, loc); + results.analysis.apply_before_statement_effect(state, stmt, loc); vis.visit_statement_before_primary_effect(results, state, stmt, loc); - results.reconstruct_statement_effect(state, stmt, loc); + results.analysis.apply_statement_effect(state, stmt, loc); vis.visit_statement_after_primary_effect(results, state, stmt, loc); } let loc = Location { block, statement_index: block_data.statements.len() }; let term = block_data.terminator(); - results.reconstruct_before_terminator_effect(state, term, loc); + results.analysis.apply_before_terminator_effect(state, term, loc); vis.visit_terminator_before_primary_effect(results, state, term, loc); - results.reconstruct_terminator_effect(state, term, loc); + results.analysis.apply_terminator_effect(state, term, loc); vis.visit_terminator_after_primary_effect(results, state, term, loc); vis.visit_block_end(state); diff --git a/compiler/rustc_mir_dataflow/src/framework/graphviz.rs b/compiler/rustc_mir_dataflow/src/framework/graphviz.rs index bac75b972f9b1..98a4f58cb5dc3 100644 --- a/compiler/rustc_mir_dataflow/src/framework/graphviz.rs +++ b/compiler/rustc_mir_dataflow/src/framework/graphviz.rs @@ -544,20 +544,18 @@ impl StateDiffCollector { } } -impl<'tcx, A> ResultsVisitor<'_, 'tcx, Results<'tcx, A>> for StateDiffCollector +impl<'tcx, A> ResultsVisitor<'_, 'tcx, A> for StateDiffCollector where A: Analysis<'tcx>, A::Domain: DebugWithContext, { - type Domain = A::Domain; - - fn visit_block_start(&mut self, state: &Self::Domain) { + fn visit_block_start(&mut self, state: &A::Domain) { if A::Direction::IS_FORWARD { self.prev_state.clone_from(state); } } - fn visit_block_end(&mut self, state: &Self::Domain) { + fn visit_block_end(&mut self, state: &A::Domain) { if A::Direction::IS_BACKWARD { self.prev_state.clone_from(state); } @@ -566,7 +564,7 @@ where fn visit_statement_before_primary_effect( &mut self, results: &mut Results<'tcx, A>, - state: &Self::Domain, + state: &A::Domain, _statement: &mir::Statement<'tcx>, _location: Location, ) { @@ -579,7 +577,7 @@ where fn visit_statement_after_primary_effect( &mut self, results: &mut Results<'tcx, A>, - state: &Self::Domain, + state: &A::Domain, _statement: &mir::Statement<'tcx>, _location: Location, ) { @@ -590,7 +588,7 @@ where fn visit_terminator_before_primary_effect( &mut self, results: &mut Results<'tcx, A>, - state: &Self::Domain, + state: &A::Domain, _terminator: &mir::Terminator<'tcx>, _location: Location, ) { @@ -603,7 +601,7 @@ where fn visit_terminator_after_primary_effect( &mut self, results: &mut Results<'tcx, A>, - state: &Self::Domain, + state: &A::Domain, _terminator: &mir::Terminator<'tcx>, _location: Location, ) { diff --git a/compiler/rustc_mir_dataflow/src/framework/mod.rs b/compiler/rustc_mir_dataflow/src/framework/mod.rs index 4ad681935285d..244dfe26ad362 100644 --- a/compiler/rustc_mir_dataflow/src/framework/mod.rs +++ b/compiler/rustc_mir_dataflow/src/framework/mod.rs @@ -56,7 +56,7 @@ pub use self::cursor::ResultsCursor; pub use self::direction::{Backward, Direction, Forward}; pub use self::lattice::{JoinSemiLattice, MaybeReachable}; pub use self::results::{EntrySets, Results}; -pub use self::visitor::{ResultsVisitable, ResultsVisitor, visit_results}; +pub use self::visitor::{ResultsVisitor, visit_results}; /// Analysis domains are all bitsets of various kinds. This trait holds /// operations needed by all of them. diff --git a/compiler/rustc_mir_dataflow/src/framework/results.rs b/compiler/rustc_mir_dataflow/src/framework/results.rs index 2269c4ec22696..ff6cafbfbaee6 100644 --- a/compiler/rustc_mir_dataflow/src/framework/results.rs +++ b/compiler/rustc_mir_dataflow/src/framework/results.rs @@ -51,7 +51,7 @@ where &mut self, body: &'mir mir::Body<'tcx>, blocks: impl IntoIterator, - vis: &mut impl ResultsVisitor<'mir, 'tcx, Self, Domain = A::Domain>, + vis: &mut impl ResultsVisitor<'mir, 'tcx, A>, ) { visit_results(body, blocks, self, vis) } @@ -59,7 +59,7 @@ where pub fn visit_reachable_with<'mir>( &mut self, body: &'mir mir::Body<'tcx>, - vis: &mut impl ResultsVisitor<'mir, 'tcx, Self, Domain = A::Domain>, + vis: &mut impl ResultsVisitor<'mir, 'tcx, A>, ) { let blocks = traversal::reachable(body); visit_results(body, blocks.map(|(bb, _)| bb), self, vis) diff --git a/compiler/rustc_mir_dataflow/src/framework/visitor.rs b/compiler/rustc_mir_dataflow/src/framework/visitor.rs index 3d6b008a6846d..5c7539eed4d6a 100644 --- a/compiler/rustc_mir_dataflow/src/framework/visitor.rs +++ b/compiler/rustc_mir_dataflow/src/framework/visitor.rs @@ -4,15 +4,15 @@ use super::{Analysis, Direction, Results}; /// Calls the corresponding method in `ResultsVisitor` for every location in a `mir::Body` with the /// dataflow state at that location. -pub fn visit_results<'mir, 'tcx, D, R>( +pub fn visit_results<'mir, 'tcx, A>( body: &'mir mir::Body<'tcx>, blocks: impl IntoIterator, - results: &mut R, - vis: &mut impl ResultsVisitor<'mir, 'tcx, R, Domain = D>, + results: &mut Results<'tcx, A>, + vis: &mut impl ResultsVisitor<'mir, 'tcx, A>, ) where - R: ResultsVisitable<'tcx, Domain = D>, + A: Analysis<'tcx>, { - let mut state = results.bottom_value(body); + let mut state = results.analysis.bottom_value(body); #[cfg(debug_assertions)] let reachable_blocks = mir::traversal::reachable_as_bitset(body); @@ -22,23 +22,23 @@ pub fn visit_results<'mir, 'tcx, D, R>( assert!(reachable_blocks.contains(block)); let block_data = &body[block]; - R::Direction::visit_results_in_block(&mut state, block, block_data, results, vis); + A::Direction::visit_results_in_block(&mut state, block, block_data, results, vis); } } -/// A visitor over the results of an `Analysis`. The type parameter `R` is the results type being -/// visited. -pub trait ResultsVisitor<'mir, 'tcx, R> { - type Domain; - - fn visit_block_start(&mut self, _state: &Self::Domain) {} +/// A visitor over the results of an `Analysis`. +pub trait ResultsVisitor<'mir, 'tcx, A> +where + A: Analysis<'tcx>, +{ + fn visit_block_start(&mut self, _state: &A::Domain) {} /// Called with the `before_statement_effect` of the given statement applied to `state` but not /// its `statement_effect`. fn visit_statement_before_primary_effect( &mut self, - _results: &mut R, - _state: &Self::Domain, + _results: &mut Results<'tcx, A>, + _state: &A::Domain, _statement: &'mir mir::Statement<'tcx>, _location: Location, ) { @@ -48,19 +48,19 @@ pub trait ResultsVisitor<'mir, 'tcx, R> { /// statement applied to `state`. fn visit_statement_after_primary_effect( &mut self, - _results: &mut R, - _state: &Self::Domain, + _results: &mut Results<'tcx, A>, + _state: &A::Domain, _statement: &'mir mir::Statement<'tcx>, _location: Location, ) { } - /// Called with the `before_terminator_effect` of the given terminator applied to `state` but not - /// its `terminator_effect`. + /// Called with the `before_terminator_effect` of the given terminator applied to `state` but + /// not its `terminator_effect`. fn visit_terminator_before_primary_effect( &mut self, - _results: &mut R, - _state: &Self::Domain, + _results: &mut Results<'tcx, A>, + _state: &A::Domain, _terminator: &'mir mir::Terminator<'tcx>, _location: Location, ) { @@ -72,109 +72,12 @@ pub trait ResultsVisitor<'mir, 'tcx, R> { /// The `call_return_effect` (if one exists) will *not* be applied to `state`. fn visit_terminator_after_primary_effect( &mut self, - _results: &mut R, - _state: &Self::Domain, + _results: &mut Results<'tcx, A>, + _state: &A::Domain, _terminator: &'mir mir::Terminator<'tcx>, _location: Location, ) { } - fn visit_block_end(&mut self, _state: &Self::Domain) {} -} - -/// Things that can be visited by a `ResultsVisitor`. -/// -/// This trait exists so that we can visit the results of one or more dataflow analyses -/// simultaneously. -pub trait ResultsVisitable<'tcx> { - type Direction: Direction; - type Domain; - - /// Creates an empty `Domain` to hold the transient state for these dataflow results. - /// - /// The value of the newly created `Domain` will be overwritten by `reset_to_block_entry` - /// before it can be observed by a `ResultsVisitor`. - fn bottom_value(&self, body: &mir::Body<'tcx>) -> Self::Domain; - - fn reset_to_block_entry(&self, state: &mut Self::Domain, block: BasicBlock); - - fn reconstruct_before_statement_effect( - &mut self, - state: &mut Self::Domain, - statement: &mir::Statement<'tcx>, - location: Location, - ); - - fn reconstruct_statement_effect( - &mut self, - state: &mut Self::Domain, - statement: &mir::Statement<'tcx>, - location: Location, - ); - - fn reconstruct_before_terminator_effect( - &mut self, - state: &mut Self::Domain, - terminator: &mir::Terminator<'tcx>, - location: Location, - ); - - fn reconstruct_terminator_effect( - &mut self, - state: &mut Self::Domain, - terminator: &mir::Terminator<'tcx>, - location: Location, - ); -} - -impl<'tcx, A> ResultsVisitable<'tcx> for Results<'tcx, A> -where - A: Analysis<'tcx>, -{ - type Domain = A::Domain; - type Direction = A::Direction; - - fn bottom_value(&self, body: &mir::Body<'tcx>) -> Self::Domain { - self.analysis.bottom_value(body) - } - - fn reset_to_block_entry(&self, state: &mut Self::Domain, block: BasicBlock) { - state.clone_from(self.entry_set_for_block(block)); - } - - fn reconstruct_before_statement_effect( - &mut self, - state: &mut Self::Domain, - stmt: &mir::Statement<'tcx>, - loc: Location, - ) { - self.analysis.apply_before_statement_effect(state, stmt, loc); - } - - fn reconstruct_statement_effect( - &mut self, - state: &mut Self::Domain, - stmt: &mir::Statement<'tcx>, - loc: Location, - ) { - self.analysis.apply_statement_effect(state, stmt, loc); - } - - fn reconstruct_before_terminator_effect( - &mut self, - state: &mut Self::Domain, - term: &mir::Terminator<'tcx>, - loc: Location, - ) { - self.analysis.apply_before_terminator_effect(state, term, loc); - } - - fn reconstruct_terminator_effect( - &mut self, - state: &mut Self::Domain, - term: &mir::Terminator<'tcx>, - loc: Location, - ) { - self.analysis.apply_terminator_effect(state, term, loc); - } + fn visit_block_end(&mut self, _state: &A::Domain) {} } diff --git a/compiler/rustc_mir_dataflow/src/lib.rs b/compiler/rustc_mir_dataflow/src/lib.rs index 8ebe7d593094e..ab1453f1ed091 100644 --- a/compiler/rustc_mir_dataflow/src/lib.rs +++ b/compiler/rustc_mir_dataflow/src/lib.rs @@ -19,8 +19,8 @@ pub use self::drop_flag_effects::{ }; pub use self::framework::{ Analysis, Backward, Direction, EntrySets, Forward, GenKill, JoinSemiLattice, MaybeReachable, - Results, ResultsCursor, ResultsVisitable, ResultsVisitor, SwitchIntEdgeEffects, fmt, graphviz, - lattice, visit_results, + Results, ResultsCursor, ResultsVisitor, SwitchIntEdgeEffects, fmt, graphviz, lattice, + visit_results, }; use self::move_paths::MoveData; diff --git a/compiler/rustc_mir_dataflow/src/points.rs b/compiler/rustc_mir_dataflow/src/points.rs index 73abb669a1117..10f1e00985504 100644 --- a/compiler/rustc_mir_dataflow/src/points.rs +++ b/compiler/rustc_mir_dataflow/src/points.rs @@ -3,7 +3,7 @@ use rustc_index::interval::SparseIntervalMatrix; use rustc_index::{Idx, IndexVec}; use rustc_middle::mir::{self, BasicBlock, Body, Location}; -use crate::framework::{ResultsVisitable, ResultsVisitor, visit_results}; +use crate::framework::{Analysis, Results, ResultsVisitor, visit_results}; /// Maps between a `Location` and a `PointIndex` (and vice versa). pub struct DenseLocationMap { @@ -95,14 +95,14 @@ rustc_index::newtype_index! { } /// Add points depending on the result of the given dataflow analysis. -pub fn save_as_intervals<'tcx, N, R>( +pub fn save_as_intervals<'tcx, N, A>( elements: &DenseLocationMap, body: &mir::Body<'tcx>, - mut results: R, + mut results: Results<'tcx, A>, ) -> SparseIntervalMatrix where N: Idx, - R: ResultsVisitable<'tcx, Domain = BitSet>, + A: Analysis<'tcx, Domain = BitSet>, { let values = SparseIntervalMatrix::new(elements.num_points()); let mut visitor = Visitor { elements, values }; @@ -120,16 +120,15 @@ struct Visitor<'a, N: Idx> { values: SparseIntervalMatrix, } -impl<'mir, 'tcx, R, N> ResultsVisitor<'mir, 'tcx, R> for Visitor<'_, N> +impl<'mir, 'tcx, A, N> ResultsVisitor<'mir, 'tcx, A> for Visitor<'_, N> where + A: Analysis<'tcx, Domain = BitSet>, N: Idx, { - type Domain = BitSet; - fn visit_statement_after_primary_effect( &mut self, - _results: &mut R, - state: &Self::Domain, + _results: &mut Results<'tcx, A>, + state: &A::Domain, _statement: &'mir mir::Statement<'tcx>, location: Location, ) { @@ -142,8 +141,8 @@ where fn visit_terminator_after_primary_effect( &mut self, - _results: &mut R, - state: &Self::Domain, + _results: &mut Results<'tcx, A>, + state: &A::Domain, _terminator: &'mir mir::Terminator<'tcx>, location: Location, ) { diff --git a/compiler/rustc_mir_transform/src/coroutine.rs b/compiler/rustc_mir_transform/src/coroutine.rs index 063f220501f80..c2666caa1e875 100644 --- a/compiler/rustc_mir_transform/src/coroutine.rs +++ b/compiler/rustc_mir_transform/src/coroutine.rs @@ -68,11 +68,11 @@ use rustc_middle::ty::{ self, CoroutineArgs, CoroutineArgsExt, GenericArgsRef, InstanceKind, Ty, TyCtxt, TypingMode, }; use rustc_middle::{bug, span_bug}; -use rustc_mir_dataflow::Analysis; use rustc_mir_dataflow::impls::{ MaybeBorrowedLocals, MaybeLiveLocals, MaybeRequiresStorage, MaybeStorageLive, }; use rustc_mir_dataflow::storage::always_storage_live_locals; +use rustc_mir_dataflow::{Analysis, Results, ResultsVisitor}; use rustc_span::Span; use rustc_span::def_id::{DefId, LocalDefId}; use rustc_span::symbol::sym; @@ -817,9 +817,9 @@ impl ops::Deref for CoroutineSavedLocals { /// computation; see `CoroutineLayout` for more. fn compute_storage_conflicts<'mir, 'tcx>( body: &'mir Body<'tcx>, - saved_locals: &CoroutineSavedLocals, + saved_locals: &'mir CoroutineSavedLocals, always_live_locals: BitSet, - mut requires_storage: rustc_mir_dataflow::Results<'tcx, MaybeRequiresStorage<'mir, 'tcx>>, + mut requires_storage: Results<'tcx, MaybeRequiresStorage<'mir, 'tcx>>, ) -> BitMatrix { assert_eq!(body.local_decls.len(), saved_locals.domain_size()); @@ -877,15 +877,13 @@ struct StorageConflictVisitor<'a, 'tcx> { eligible_storage_live: BitSet, } -impl<'a, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'a, 'tcx, R> +impl<'a, 'tcx> ResultsVisitor<'a, 'tcx, MaybeRequiresStorage<'a, 'tcx>> for StorageConflictVisitor<'a, 'tcx> { - type Domain = BitSet; - fn visit_statement_before_primary_effect( &mut self, - _results: &mut R, - state: &Self::Domain, + _results: &mut Results<'tcx, MaybeRequiresStorage<'a, 'tcx>>, + state: &BitSet, _statement: &'a Statement<'tcx>, loc: Location, ) { @@ -894,8 +892,8 @@ impl<'a, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'a, 'tcx, R> fn visit_terminator_before_primary_effect( &mut self, - _results: &mut R, - state: &Self::Domain, + _results: &mut Results<'tcx, MaybeRequiresStorage<'a, 'tcx>>, + state: &BitSet, _terminator: &'a Terminator<'tcx>, loc: Location, ) { diff --git a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs index 7d073f1fa5794..ab6460c490b84 100644 --- a/compiler/rustc_mir_transform/src/dataflow_const_prop.rs +++ b/compiler/rustc_mir_transform/src/dataflow_const_prop.rs @@ -941,16 +941,12 @@ fn try_write_constant<'tcx>( interp_ok(()) } -impl<'mir, 'tcx> ResultsVisitor<'mir, 'tcx, Results<'tcx, ConstAnalysis<'_, 'tcx>>> - for Collector<'_, 'tcx> -{ - type Domain = State>; - +impl<'mir, 'tcx> ResultsVisitor<'mir, 'tcx, ConstAnalysis<'_, 'tcx>> for Collector<'_, 'tcx> { #[instrument(level = "trace", skip(self, results, statement))] fn visit_statement_before_primary_effect( &mut self, results: &mut Results<'tcx, ConstAnalysis<'_, 'tcx>>, - state: &Self::Domain, + state: &State>, statement: &'mir Statement<'tcx>, location: Location, ) { @@ -972,7 +968,7 @@ impl<'mir, 'tcx> ResultsVisitor<'mir, 'tcx, Results<'tcx, ConstAnalysis<'_, 'tcx fn visit_statement_after_primary_effect( &mut self, results: &mut Results<'tcx, ConstAnalysis<'_, 'tcx>>, - state: &Self::Domain, + state: &State>, statement: &'mir Statement<'tcx>, location: Location, ) { @@ -997,7 +993,7 @@ impl<'mir, 'tcx> ResultsVisitor<'mir, 'tcx, Results<'tcx, ConstAnalysis<'_, 'tcx fn visit_terminator_before_primary_effect( &mut self, results: &mut Results<'tcx, ConstAnalysis<'_, 'tcx>>, - state: &Self::Domain, + state: &State>, terminator: &'mir Terminator<'tcx>, location: Location, ) {