Merge AnalysisDomain into Analysis.

With `GenKillAnalysis` gone, there is no need for them to be separate.

Author: nnethercote

compiler/rustc_borrowck/src/dataflow.rs

@@ -7,7 +7,7 @@ use rustc_middle::mir::{
 use rustc_middle::ty::{RegionVid, TyCtxt};
 use rustc_mir_dataflow::fmt::DebugWithContext;
 use rustc_mir_dataflow::impls::{EverInitializedPlaces, MaybeUninitializedPlaces};
-use rustc_mir_dataflow::{Analysis, AnalysisDomain, Forward, GenKill, Results, ResultsVisitable};
+use rustc_mir_dataflow::{Analysis, Forward, GenKill, Results, ResultsVisitable};
 use tracing::debug;
 
 use crate::{BorrowSet, PlaceConflictBias, PlaceExt, RegionInferenceContext, places_conflict};
@@ -22,9 +22,9 @@ pub(crate) struct BorrowckResults<'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: <Borrows<'a, 'tcx> as AnalysisDomain<'tcx>>::Domain,
-    pub(crate) uninits: <MaybeUninitializedPlaces<'a, 'tcx> as AnalysisDomain<'tcx>>::Domain,
-    pub(crate) ever_inits: <EverInitializedPlaces<'a, 'tcx> as AnalysisDomain<'tcx>>::Domain,
+    pub(crate) borrows: <Borrows<'a, 'tcx> as Analysis<'tcx>>::Domain,
+    pub(crate) uninits: <MaybeUninitializedPlaces<'a, 'tcx> as Analysis<'tcx>>::Domain,
+    pub(crate) ever_inits: <EverInitializedPlaces<'a, 'tcx> as Analysis<'tcx>>::Domain,
 }
 
 impl<'a, 'tcx> ResultsVisitable<'tcx> for BorrowckResults<'a, 'tcx> {
@@ -427,7 +427,7 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     /// That means they went out of a nonlexical scope
     fn kill_loans_out_of_scope_at_location(
         &self,
-        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
+        trans: &mut <Self as Analysis<'tcx>>::Domain,
         location: Location,
     ) {
         // NOTE: The state associated with a given `location`
@@ -449,7 +449,7 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     /// Kill any borrows that conflict with `place`.
     fn kill_borrows_on_place(
         &self,
-        trans: &mut <Self as AnalysisDomain<'tcx>>::Domain,
+        trans: &mut <Self as Analysis<'tcx>>::Domain,
         place: Place<'tcx>,
     ) {
         debug!("kill_borrows_on_place: place={:?}", place);
@@ -490,7 +490,14 @@ impl<'a, 'tcx> Borrows<'a, 'tcx> {
     }
 }
 
-impl<'tcx> rustc_mir_dataflow::AnalysisDomain<'tcx> for Borrows<'_, 'tcx> {
+/// Forward dataflow computation of the set of borrows that are in scope at a particular location.
+/// - we gen the introduced loans
+/// - we kill loans on locals going out of (regular) scope
+/// - we kill the loans going out of their region's NLL scope: in NLL terms, the frontier where a
+///   region stops containing the CFG points reachable from the issuing location.
+/// - we also kill loans of conflicting places when overwriting a shared path: e.g. borrows of
+///   `a.b.c` when `a` is overwritten.
+impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
     type Domain = BitSet<BorrowIndex>;
 
     const NAME: &'static str = "borrows";
@@ -504,16 +511,7 @@ impl<'tcx> rustc_mir_dataflow::AnalysisDomain<'tcx> for Borrows<'_, 'tcx> {
         // no borrows of code region_scopes have been taken prior to
         // function execution, so this method has no effect.
     }
-}
 
-/// Forward dataflow computation of the set of borrows that are in scope at a particular location.
-/// - we gen the introduced loans
-/// - we kill loans on locals going out of (regular) scope
-/// - we kill the loans going out of their region's NLL scope: in NLL terms, the frontier where a
-///   region stops containing the CFG points reachable from the issuing location.
-/// - we also kill loans of conflicting places when overwriting a shared path: e.g. borrows of
-///   `a.b.c` when `a` is overwritten.
-impl<'tcx> rustc_mir_dataflow::Analysis<'tcx> for Borrows<'_, 'tcx> {
     fn apply_before_statement_effect(
         &mut self,
         trans: &mut Self::Domain,

compiler/rustc_const_eval/src/check_consts/resolver.rs

@@ -11,7 +11,7 @@ use rustc_middle::mir::{
     self, BasicBlock, CallReturnPlaces, Local, Location, Statement, StatementKind, TerminatorEdges,
 };
 use rustc_mir_dataflow::fmt::DebugWithContext;
-use rustc_mir_dataflow::{Analysis, AnalysisDomain, JoinSemiLattice};
+use rustc_mir_dataflow::{Analysis, JoinSemiLattice};
 
 use super::{ConstCx, Qualif, qualifs};
 
@@ -310,7 +310,7 @@ impl JoinSemiLattice for State {
     }
 }
 
-impl<'tcx, Q> AnalysisDomain<'tcx> for FlowSensitiveAnalysis<'_, '_, 'tcx, Q>
+impl<'tcx, Q> Analysis<'tcx> for FlowSensitiveAnalysis<'_, '_, 'tcx, Q>
 where
     Q: Qualif,
 {
@@ -328,12 +328,7 @@ where
     fn initialize_start_block(&self, _body: &mir::Body<'tcx>, state: &mut Self::Domain) {
         self.transfer_function(state).initialize_state();
     }
-}
 
-impl<'tcx, Q> Analysis<'tcx> for FlowSensitiveAnalysis<'_, '_, 'tcx, Q>
-where
-    Q: Qualif,
-{
     fn apply_statement_effect(
         &mut self,
         state: &mut Self::Domain,

compiler/rustc_mir_dataflow/src/framework/engine.rs

@@ -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)]

compiler/rustc_mir_dataflow/src/framework/mod.rs

@@ -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), its
+/// initial value at the entry point of each basic block, and various operations.
 ///
-/// 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> {
+/// # 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,

compiler/rustc_mir_dataflow/src/framework/tests.rs

@@ -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,

compiler/rustc_mir_dataflow/src/impls/borrowed_locals.rs

@@ -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,

compiler/rustc_mir_dataflow/src/impls/initialized.rs

@@ -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,

compiler/rustc_mir_dataflow/src/impls/liveness.rs

@@ -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,