diff --git a/compiler/rustc_mir_dataflow/src/framework/mod.rs b/compiler/rustc_mir_dataflow/src/framework/mod.rs index 5ad05921b4fd1..8f81da8bb0499 100644 --- a/compiler/rustc_mir_dataflow/src/framework/mod.rs +++ b/compiler/rustc_mir_dataflow/src/framework/mod.rs @@ -33,25 +33,29 @@ use std::cmp::Ordering; -use rustc_index::Idx; +use rustc_data_structures::work_queue::WorkQueue; use rustc_index::bit_set::{BitSet, ChunkedBitSet, HybridBitSet}; -use rustc_middle::mir::{self, BasicBlock, CallReturnPlaces, Location, TerminatorEdges}; +use rustc_index::{Idx, IndexVec}; +use rustc_middle::bug; +use rustc_middle::mir::{self, BasicBlock, CallReturnPlaces, Location, TerminatorEdges, traversal}; use rustc_middle::ty::TyCtxt; +use tracing::error; +use self::results::write_graphviz_results; use super::fmt::DebugWithContext; mod cursor; mod direction; -mod engine; pub mod fmt; pub mod graphviz; pub mod lattice; +mod results; mod visitor; pub use self::cursor::ResultsCursor; pub use self::direction::{Backward, Direction, Forward}; -pub use self::engine::{Engine, Results}; pub use self::lattice::{JoinSemiLattice, MaybeReachable}; +pub use self::results::Results; pub use self::visitor::{ResultsVisitable, ResultsVisitor, visit_results}; /// Analysis domains are all bitsets of various kinds. This trait holds @@ -238,7 +242,7 @@ pub trait Analysis<'tcx> { /// Without a `pass_name` to differentiates them, only the results for the latest run will be /// saved. fn iterate_to_fixpoint<'mir>( - self, + mut self, tcx: TyCtxt<'tcx>, body: &'mir mir::Body<'tcx>, pass_name: Option<&'static str>, @@ -247,7 +251,69 @@ pub trait Analysis<'tcx> { Self: Sized, Self::Domain: DebugWithContext, { - Engine::iterate_to_fixpoint(tcx, body, self, pass_name) + let mut entry_sets = + IndexVec::from_fn_n(|_| self.bottom_value(body), body.basic_blocks.len()); + self.initialize_start_block(body, &mut entry_sets[mir::START_BLOCK]); + + if Self::Direction::IS_BACKWARD && entry_sets[mir::START_BLOCK] != self.bottom_value(body) { + bug!("`initialize_start_block` is not yet supported for backward dataflow analyses"); + } + + let mut dirty_queue: WorkQueue = WorkQueue::with_none(body.basic_blocks.len()); + + if Self::Direction::IS_FORWARD { + for (bb, _) in traversal::reverse_postorder(body) { + dirty_queue.insert(bb); + } + } else { + // Reverse post-order on the reverse CFG may generate a better iteration order for + // backward dataflow analyses, but probably not enough to matter. + for (bb, _) in traversal::postorder(body) { + dirty_queue.insert(bb); + } + } + + // `state` is not actually used between iterations; + // this is just an optimization to avoid reallocating + // every iteration. + let mut state = self.bottom_value(body); + while let Some(bb) = dirty_queue.pop() { + let bb_data = &body[bb]; + + // Set the state to the entry state of the block. + // This is equivalent to `state = entry_sets[bb].clone()`, + // but it saves an allocation, thus improving compile times. + state.clone_from(&entry_sets[bb]); + + // Apply the block transfer function, using the cached one if it exists. + let edges = Self::Direction::apply_effects_in_block(&mut self, &mut state, bb, bb_data); + + Self::Direction::join_state_into_successors_of( + &mut self, + body, + &mut state, + bb, + edges, + |target: BasicBlock, state: &Self::Domain| { + let set_changed = entry_sets[target].join(state); + if set_changed { + dirty_queue.insert(target); + } + }, + ); + } + + let results = Results { analysis: self, entry_sets }; + + if tcx.sess.opts.unstable_opts.dump_mir_dataflow { + let (res, results) = write_graphviz_results(tcx, body, results, pass_name); + if let Err(e) = res { + error!("Failed to write graphviz dataflow results: {}", e); + } + results + } else { + results + } } } diff --git a/compiler/rustc_mir_dataflow/src/framework/engine.rs b/compiler/rustc_mir_dataflow/src/framework/results.rs similarity index 66% rename from compiler/rustc_mir_dataflow/src/framework/engine.rs rename to compiler/rustc_mir_dataflow/src/framework/results.rs index 44fda84ce03ef..366fcbf33ba3c 100644 --- a/compiler/rustc_mir_dataflow/src/framework/engine.rs +++ b/compiler/rustc_mir_dataflow/src/framework/results.rs @@ -1,23 +1,19 @@ -//! A solver for dataflow problems. +//! Dataflow analysis results. use std::ffi::OsString; use std::path::PathBuf; -use rustc_data_structures::work_queue::WorkQueue; use rustc_hir::def_id::DefId; use rustc_index::IndexVec; -use rustc_middle::bug; use rustc_middle::mir::{self, BasicBlock, create_dump_file, dump_enabled, traversal}; use rustc_middle::ty::TyCtxt; use rustc_middle::ty::print::with_no_trimmed_paths; use rustc_span::symbol::{Symbol, sym}; -use tracing::{debug, error}; +use tracing::debug; use {rustc_ast as ast, rustc_graphviz as dot}; use super::fmt::DebugWithContext; -use super::{ - Analysis, Direction, JoinSemiLattice, ResultsCursor, ResultsVisitor, graphviz, visit_results, -}; +use super::{Analysis, ResultsCursor, ResultsVisitor, graphviz, visit_results}; use crate::errors::{ DuplicateValuesFor, PathMustEndInFilename, RequiresAnArgument, UnknownFormatter, }; @@ -65,101 +61,17 @@ where body: &'mir mir::Body<'tcx>, vis: &mut impl ResultsVisitor<'mir, 'tcx, Self, Domain = A::Domain>, ) { - let blocks = mir::traversal::reachable(body); + let blocks = traversal::reachable(body); visit_results(body, blocks.map(|(bb, _)| bb), self, vis) } } -/// A solver for dataflow problems. -pub struct Engine; - -impl Engine { - /// Creates a new `Engine` to solve a dataflow problem with an arbitrary transfer - /// function. - pub(crate) fn iterate_to_fixpoint<'mir, 'tcx, A>( - tcx: TyCtxt<'tcx>, - body: &'mir mir::Body<'tcx>, - mut analysis: A, - pass_name: Option<&'static str>, - ) -> Results<'tcx, A> - where - A: Analysis<'tcx>, - A::Domain: DebugWithContext + Clone + JoinSemiLattice, - { - let mut entry_sets = - IndexVec::from_fn_n(|_| analysis.bottom_value(body), body.basic_blocks.len()); - analysis.initialize_start_block(body, &mut entry_sets[mir::START_BLOCK]); - - if A::Direction::IS_BACKWARD && entry_sets[mir::START_BLOCK] != analysis.bottom_value(body) - { - bug!("`initialize_start_block` is not yet supported for backward dataflow analyses"); - } - - let mut dirty_queue: WorkQueue = WorkQueue::with_none(body.basic_blocks.len()); - - if A::Direction::IS_FORWARD { - for (bb, _) in traversal::reverse_postorder(body) { - dirty_queue.insert(bb); - } - } else { - // Reverse post-order on the reverse CFG may generate a better iteration order for - // backward dataflow analyses, but probably not enough to matter. - for (bb, _) in traversal::postorder(body) { - dirty_queue.insert(bb); - } - } - - // `state` is not actually used between iterations; - // this is just an optimization to avoid reallocating - // every iteration. - let mut state = analysis.bottom_value(body); - while let Some(bb) = dirty_queue.pop() { - let bb_data = &body[bb]; - - // Set the state to the entry state of the block. - // This is equivalent to `state = entry_sets[bb].clone()`, - // but it saves an allocation, thus improving compile times. - state.clone_from(&entry_sets[bb]); - - // Apply the block transfer function, using the cached one if it exists. - let edges = - A::Direction::apply_effects_in_block(&mut analysis, &mut state, bb, bb_data); - - A::Direction::join_state_into_successors_of( - &mut analysis, - body, - &mut state, - bb, - edges, - |target: BasicBlock, state: &A::Domain| { - let set_changed = entry_sets[target].join(state); - if set_changed { - dirty_queue.insert(target); - } - }, - ); - } - - let results = Results { analysis, entry_sets }; - - if tcx.sess.opts.unstable_opts.dump_mir_dataflow { - let (res, results) = write_graphviz_results(tcx, body, results, pass_name); - if let Err(e) = res { - error!("Failed to write graphviz dataflow results: {}", e); - } - results - } else { - results - } - } -} - // Graphviz /// Writes a DOT file containing the results of a dataflow analysis if the user requested it via /// `rustc_mir` attributes and `-Z dump-mir-dataflow`. The `Result` in and the `Results` out are /// the same. -fn write_graphviz_results<'tcx, A>( +pub(super) fn write_graphviz_results<'tcx, A>( tcx: TyCtxt<'tcx>, body: &mir::Body<'tcx>, results: Results<'tcx, A>, diff --git a/compiler/rustc_mir_dataflow/src/lib.rs b/compiler/rustc_mir_dataflow/src/lib.rs index b284f0308f979..b404e3bfb72c3 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, Engine, Forward, GenKill, JoinSemiLattice, MaybeReachable, - Results, ResultsCursor, ResultsVisitable, ResultsVisitor, SwitchIntEdgeEffects, fmt, graphviz, - lattice, visit_results, + Analysis, Backward, Direction, Forward, GenKill, JoinSemiLattice, MaybeReachable, Results, + ResultsCursor, ResultsVisitable, ResultsVisitor, SwitchIntEdgeEffects, fmt, graphviz, lattice, + visit_results, }; use self::move_paths::MoveData;