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Merge AnalysisDomain into Analysis.

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With `GenKillAnalysis` gone, there is no need for them to be separate.
This commit is contained in:
Nicholas Nethercote 2024-10-10 11:46:29 +11:00
parent 4dc1b4d0b1
commit ba13775319
11 changed files with 62 additions and 105 deletions
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5
compiler/rustc_mir_dataflow/src/framework/engine.rs
View file

@ -16,14 +16,13 @@ use {rustc_ast as ast, rustc_graphviz as dot};
use super::fmt::DebugWithContext;
use super::{
Analysis, AnalysisDomain, Direction, JoinSemiLattice, ResultsCursor, ResultsVisitor, graphviz,
visit_results,
Analysis, Direction, JoinSemiLattice, ResultsCursor, ResultsVisitor, graphviz, visit_results,
};
use crate::errors::{
DuplicateValuesFor, PathMustEndInFilename, RequiresAnArgument, UnknownFormatter,
};
type EntrySets<'tcx, A> = IndexVec<BasicBlock, <A as AnalysisDomain<'tcx>>::Domain>;
type EntrySets<'tcx, A> = IndexVec<BasicBlock, <A as Analysis<'tcx>>::Domain>;
/// A dataflow analysis that has converged to fixpoint.
#[derive(Clone)]

41
compiler/rustc_mir_dataflow/src/framework/mod.rs
View file

@ -89,11 +89,26 @@ impl<T: Idx> BitSetExt<T> for ChunkedBitSet<T> {
}
}
/// Defines the domain of a dataflow problem.
/// A dataflow problem with an arbitrarily complex transfer function.
///
/// This trait specifies the lattice on which this analysis operates (the domain) as well as its
/// initial value at the entry point of each basic block.
pub trait AnalysisDomain<'tcx> {
/// This trait specifies the lattice on which this analysis operates (the domain), its
/// initial value at the entry point of each basic block, and various operations.
///
/// # Convergence
///
/// When implementing this trait it's possible to choose a transfer function such that the analysis
/// does not reach fixpoint. To guarantee convergence, your transfer functions must maintain the
/// following invariant:
///
/// > If the dataflow state **before** some point in the program changes to be greater
/// than the prior state **before** that point, the dataflow state **after** that point must
/// also change to be greater than the prior state **after** that point.
///
/// This invariant guarantees that the dataflow state at a given point in the program increases
/// monotonically until fixpoint is reached. Note that this monotonicity requirement only applies
/// to the same point in the program at different points in time. The dataflow state at a given
/// point in the program may or may not be greater than the state at any preceding point.
pub trait Analysis<'tcx> {
/// The type that holds the dataflow state at any given point in the program.
type Domain: Clone + JoinSemiLattice;
@ -118,25 +133,7 @@ pub trait AnalysisDomain<'tcx> {
// block where control flow could exit the MIR body (e.g., those terminated with `return` or
// `resume`). It's not obvious how to handle `yield` points in coroutines, however.
fn initialize_start_block(&self, body: &mir::Body<'tcx>, state: &mut Self::Domain);
}
/// A dataflow problem with an arbitrarily complex transfer function.
///
/// # Convergence
///
/// When implementing this trait it's possible to choose a transfer function such that the analysis
/// does not reach fixpoint. To guarantee convergence, your transfer functions must maintain the
/// following invariant:
///
/// > If the dataflow state **before** some point in the program changes to be greater
/// than the prior state **before** that point, the dataflow state **after** that point must
/// also change to be greater than the prior state **after** that point.
///
/// This invariant guarantees that the dataflow state at a given point in the program increases
/// monotonically until fixpoint is reached. Note that this monotonicity requirement only applies
/// to the same point in the program at different points in time. The dataflow state at a given
/// point in the program may or may not be greater than the state at any preceding point.
pub trait Analysis<'tcx>: AnalysisDomain<'tcx> {
/// Updates the current dataflow state with the effect of evaluating a statement.
fn apply_statement_effect(
&mut self,

4
compiler/rustc_mir_dataflow/src/framework/tests.rs
View file

@ -154,7 +154,7 @@ impl<D: Direction> MockAnalysis<'_, D> {
}
}
impl<'tcx, D: Direction> AnalysisDomain<'tcx> for MockAnalysis<'tcx, D> {
impl<'tcx, D: Direction> Analysis<'tcx> for MockAnalysis<'tcx, D> {
type Domain = BitSet<usize>;
type Direction = D;
@ -167,9 +167,7 @@ impl<'tcx, D: Direction> AnalysisDomain<'tcx> for MockAnalysis<'tcx, D> {
fn initialize_start_block(&self, _: &mir::Body<'tcx>, _: &mut Self::Domain) {
unimplemented!("This is never called since `MockAnalysis` is never iterated to fixpoint");
}
}
impl<'tcx, D: Direction> Analysis<'tcx> for MockAnalysis<'tcx, D> {
fn apply_statement_effect(
&mut self,
state: &mut Self::Domain,

6
compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs
View file

@ -2,7 +2,7 @@ use rustc_index::bit_set::BitSet;
use rustc_middle::mir::visit::Visitor;
use rustc_middle::mir::*;
use crate::{Analysis, AnalysisDomain, GenKill};
use crate::{Analysis, GenKill};
/// A dataflow analysis that tracks whether a pointer or reference could possibly exist that points
/// to a given local. This analysis ignores fake borrows, so it should not be used by
@ -20,7 +20,7 @@ impl MaybeBorrowedLocals {
}
}
impl<'tcx> AnalysisDomain<'tcx> for MaybeBorrowedLocals {
impl<'tcx> Analysis<'tcx> for MaybeBorrowedLocals {
type Domain = BitSet<Local>;
const NAME: &'static str = "maybe_borrowed_locals";
@ -32,9 +32,7 @@ impl<'tcx> AnalysisDomain<'tcx> for MaybeBorrowedLocals {
fn initialize_start_block(&self, _: &Body<'tcx>, _: &mut Self::Domain) {
// No locals are aliased on function entry
}
}
impl<'tcx> Analysis<'tcx> for MaybeBorrowedLocals {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,

27
compiler/rustc_mir_dataflow/src/impls/initialized.rs
View file

@ -11,9 +11,8 @@ use crate::elaborate_drops::DropFlagState;
use crate::framework::SwitchIntEdgeEffects;
use crate::move_paths::{HasMoveData, InitIndex, InitKind, LookupResult, MoveData, MovePathIndex};
use crate::{
Analysis, AnalysisDomain, GenKill, MaybeReachable, drop_flag_effects,
drop_flag_effects_for_function_entry, drop_flag_effects_for_location, lattice,
on_all_children_bits, on_lookup_result_bits,
Analysis, GenKill, MaybeReachable, drop_flag_effects, drop_flag_effects_for_function_entry,
drop_flag_effects_for_location, lattice, on_all_children_bits, on_lookup_result_bits,
};
/// `MaybeInitializedPlaces` tracks all places that might be
@ -270,7 +269,7 @@ impl<'tcx> HasMoveData<'tcx> for EverInitializedPlaces<'_, 'tcx> {
impl<'a, 'tcx> MaybeInitializedPlaces<'a, 'tcx> {
fn update_bits(
trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
trans: &mut <Self as Analysis<'tcx>>::Domain,
path: MovePathIndex,
state: DropFlagState,
) {
@ -283,7 +282,7 @@ impl<'a, 'tcx> MaybeInitializedPlaces<'a, 'tcx> {
impl<'tcx> MaybeUninitializedPlaces<'_, 'tcx> {
fn update_bits(
trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
trans: &mut <Self as Analysis<'tcx>>::Domain,
path: MovePathIndex,
state: DropFlagState,
) {
@ -296,7 +295,7 @@ impl<'tcx> MaybeUninitializedPlaces<'_, 'tcx> {
impl<'a, 'tcx> DefinitelyInitializedPlaces<'a, 'tcx> {
fn update_bits(
trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
trans: &mut <Self as Analysis<'tcx>>::Domain,
path: MovePathIndex,
state: DropFlagState,
) {
@ -307,7 +306,7 @@ impl<'a, 'tcx> DefinitelyInitializedPlaces<'a, 'tcx> {
}
}
impl<'tcx> AnalysisDomain<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
impl<'tcx> Analysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
/// There can be many more `MovePathIndex` than there are locals in a MIR body.
/// We use a chunked bitset to avoid paying too high a memory footprint.
type Domain = MaybeReachable<ChunkedBitSet<MovePathIndex>>;
@ -327,9 +326,7 @@ impl<'tcx> AnalysisDomain<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
state.gen_(path);
});
}
}
impl<'tcx> Analysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,
@ -436,7 +433,7 @@ impl<'tcx> Analysis<'tcx> for MaybeInitializedPlaces<'_, 'tcx> {
}
}
impl<'tcx> AnalysisDomain<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
impl<'tcx> Analysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
/// There can be many more `MovePathIndex` than there are locals in a MIR body.
/// We use a chunked bitset to avoid paying too high a memory footprint.
type Domain = ChunkedBitSet<MovePathIndex>;
@ -458,9 +455,7 @@ impl<'tcx> AnalysisDomain<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
state.remove(path);
});
}
}
impl<'tcx> Analysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,
@ -559,7 +554,7 @@ impl<'tcx> Analysis<'tcx> for MaybeUninitializedPlaces<'_, 'tcx> {
}
}
impl<'a, 'tcx> AnalysisDomain<'tcx> for DefinitelyInitializedPlaces<'a, 'tcx> {
impl<'a, 'tcx> Analysis<'tcx> for DefinitelyInitializedPlaces<'a, 'tcx> {
/// Use set intersection as the join operator.
type Domain = lattice::Dual<BitSet<MovePathIndex>>;
@ -579,9 +574,7 @@ impl<'a, 'tcx> AnalysisDomain<'tcx> for DefinitelyInitializedPlaces<'a, 'tcx> {
state.0.insert(path);
});
}
}
impl<'tcx> Analysis<'tcx> for DefinitelyInitializedPlaces<'_, 'tcx> {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,
@ -625,7 +618,7 @@ impl<'tcx> Analysis<'tcx> for DefinitelyInitializedPlaces<'_, 'tcx> {
}
}
impl<'tcx> AnalysisDomain<'tcx> for EverInitializedPlaces<'_, 'tcx> {
impl<'tcx> Analysis<'tcx> for EverInitializedPlaces<'_, 'tcx> {
/// There can be many more `InitIndex` than there are locals in a MIR body.
/// We use a chunked bitset to avoid paying too high a memory footprint.
type Domain = ChunkedBitSet<InitIndex>;
@ -642,9 +635,7 @@ impl<'tcx> AnalysisDomain<'tcx> for EverInitializedPlaces<'_, 'tcx> {
state.insert(InitIndex::new(arg_init));
}
}
}
impl<'tcx> Analysis<'tcx> for EverInitializedPlaces<'_, 'tcx> {
#[instrument(skip(self, trans), level = "debug")]
fn apply_statement_effect(
&mut self,

10
compiler/rustc_mir_dataflow/src/impls/liveness.rs
View file

@ -4,7 +4,7 @@ use rustc_middle::mir::{
self, CallReturnPlaces, Local, Location, Place, StatementKind, TerminatorEdges,
};
use crate::{Analysis, AnalysisDomain, Backward, GenKill};
use crate::{Analysis, Backward, GenKill};
/// A [live-variable dataflow analysis][liveness].
///
@ -25,7 +25,7 @@ use crate::{Analysis, AnalysisDomain, Backward, GenKill};
/// [liveness]: https://en.wikipedia.org/wiki/Live_variable_analysis
pub struct MaybeLiveLocals;
impl<'tcx> AnalysisDomain<'tcx> for MaybeLiveLocals {
impl<'tcx> Analysis<'tcx> for MaybeLiveLocals {
type Domain = BitSet<Local>;
type Direction = Backward;
@ -39,9 +39,7 @@ impl<'tcx> AnalysisDomain<'tcx> for MaybeLiveLocals {
fn initialize_start_block(&self, _: &mir::Body<'tcx>, _: &mut Self::Domain) {
// No variables are live until we observe a use
}
}
impl<'tcx> Analysis<'tcx> for MaybeLiveLocals {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,
@ -219,7 +217,7 @@ impl<'a> MaybeTransitiveLiveLocals<'a> {
}
}
impl<'a, 'tcx> AnalysisDomain<'tcx> for MaybeTransitiveLiveLocals<'a> {
impl<'a, 'tcx> Analysis<'tcx> for MaybeTransitiveLiveLocals<'a> {
type Domain = BitSet<Local>;
type Direction = Backward;
@ -233,9 +231,7 @@ impl<'a, 'tcx> AnalysisDomain<'tcx> for MaybeTransitiveLiveLocals<'a> {
fn initialize_start_block(&self, _: &mir::Body<'tcx>, _: &mut Self::Domain) {
// No variables are live until we observe a use
}
}
impl<'a, 'tcx> Analysis<'tcx> for MaybeTransitiveLiveLocals<'a> {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,

20
compiler/rustc_mir_dataflow/src/impls/storage_liveness.rs
View file

@ -5,7 +5,7 @@ use rustc_middle::mir::visit::{NonMutatingUseContext, PlaceContext, Visitor};
use rustc_middle::mir::*;
use super::MaybeBorrowedLocals;
use crate::{Analysis, AnalysisDomain, GenKill, ResultsCursor};
use crate::{Analysis, GenKill, ResultsCursor};
pub struct MaybeStorageLive<'a> {
always_live_locals: Cow<'a, BitSet<Local>>,
@ -17,7 +17,7 @@ impl<'a> MaybeStorageLive<'a> {
}
}
impl<'a, 'tcx> AnalysisDomain<'tcx> for MaybeStorageLive<'a> {
impl<'a, 'tcx> Analysis<'tcx> for MaybeStorageLive<'a> {
type Domain = BitSet<Local>;
const NAME: &'static str = "maybe_storage_live";
@ -37,9 +37,7 @@ impl<'a, 'tcx> AnalysisDomain<'tcx> for MaybeStorageLive<'a> {
on_entry.insert(arg);
}
}
}
impl<'a, 'tcx> Analysis<'tcx> for MaybeStorageLive<'a> {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,
@ -83,7 +81,7 @@ impl<'a> MaybeStorageDead<'a> {
}
}
impl<'a, 'tcx> AnalysisDomain<'tcx> for MaybeStorageDead<'a> {
impl<'a, 'tcx> Analysis<'tcx> for MaybeStorageDead<'a> {
type Domain = BitSet<Local>;
const NAME: &'static str = "maybe_storage_dead";
@ -102,9 +100,7 @@ impl<'a, 'tcx> AnalysisDomain<'tcx> for MaybeStorageDead<'a> {
}
}
}
}
impl<'a, 'tcx> Analysis<'tcx> for MaybeStorageDead<'a> {
fn apply_statement_effect(
&mut self,
trans: &mut Self::Domain,
@ -152,7 +148,7 @@ impl<'mir, 'tcx> MaybeRequiresStorage<'mir, 'tcx> {
}
}
impl<'tcx> AnalysisDomain<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
impl<'tcx> Analysis<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
type Domain = BitSet<Local>;
const NAME: &'static str = "requires_storage";
@ -169,9 +165,7 @@ impl<'tcx> AnalysisDomain<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
on_entry.insert(arg);
}
}
}
impl<'tcx> Analysis<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
fn apply_before_statement_effect(
&mut self,
trans: &mut Self::Domain,
@ -327,11 +321,7 @@ impl<'tcx> Analysis<'tcx> for MaybeRequiresStorage<'_, 'tcx> {
impl<'tcx> MaybeRequiresStorage<'_, 'tcx> {
/// Kill locals that are fully moved and have not been borrowed.
fn check_for_move(
&mut self,
trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
loc: Location,
) {
fn check_for_move(&mut self, trans: &mut <Self as Analysis<'tcx>>::Domain, loc: Location) {
let body = self.borrowed_locals.body();
let mut visitor = MoveVisitor { trans, borrowed_locals: &mut self.borrowed_locals };
visitor.visit_location(body, loc);

6
compiler/rustc_mir_dataflow/src/lib.rs
View file

@ -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, AnalysisDomain, Backward, Direction, Engine, Forward, GenKill, JoinSemiLattice,
MaybeReachable, Results, ResultsCursor, ResultsVisitable, ResultsVisitor, SwitchIntEdgeEffects,
fmt, graphviz, lattice, visit_results,
Analysis, Backward, Direction, Engine, Forward, GenKill, JoinSemiLattice, MaybeReachable,
Results, ResultsCursor, ResultsVisitable, ResultsVisitor, SwitchIntEdgeEffects, fmt, graphviz,
lattice, visit_results,
};
use self::move_paths::MoveData;

9
compiler/rustc_mir_dataflow/src/value_analysis.rs
View file

@ -51,7 +51,7 @@ use tracing::debug;
use crate::fmt::DebugWithContext;
use crate::lattice::{HasBottom, HasTop};
use crate::{Analysis, AnalysisDomain, JoinSemiLattice, SwitchIntEdgeEffects};
use crate::{Analysis, JoinSemiLattice, SwitchIntEdgeEffects};
pub trait ValueAnalysis<'tcx> {
/// For each place of interest, the analysis tracks a value of the given type.
@ -334,7 +334,7 @@ pub trait ValueAnalysis<'tcx> {
pub struct ValueAnalysisWrapper<T>(pub T);
impl<'tcx, T: ValueAnalysis<'tcx>> AnalysisDomain<'tcx> for ValueAnalysisWrapper<T> {
impl<'tcx, T: ValueAnalysis<'tcx>> Analysis<'tcx> for ValueAnalysisWrapper<T> {
type Domain = State<T::Value>;
const NAME: &'static str = T::NAME;
@ -351,12 +351,7 @@ impl<'tcx, T: ValueAnalysis<'tcx>> AnalysisDomain<'tcx> for ValueAnalysisWrapper
state.flood(PlaceRef { local: arg, projection: &[] }, self.0.map());
}
}
}
impl<'tcx, T> Analysis<'tcx> for ValueAnalysisWrapper<T>
where
T: ValueAnalysis<'tcx>,
{
fn apply_statement_effect(
&mut self,
state: &mut Self::Domain,