Rollup merge of #98981 - pierwill:pierwill/dataflow-docs-edits, r=Dylan-DPC

Edit `rustc_mir_dataflow::framework` documentation

Some edits for clarity and consistency.
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Dylan DPC 2022-07-07 18:06:55 +05:30 committed by GitHub
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@ -1,7 +1,7 @@
//! A framework that can express both [gen-kill] and generic dataflow problems.
//!
//! To actually use this framework, you must implement either the `Analysis` or the
//! `GenKillAnalysis` trait. If your transfer function can be expressed with only gen/kill
//! To use this framework, implement either the [`Analysis`] or the
//! [`GenKillAnalysis`] trait. If your transfer function can be expressed with only gen/kill
//! operations, prefer `GenKillAnalysis` since it will run faster while iterating to fixpoint. The
//! `impls` module contains several examples of gen/kill dataflow analyses.
//!
@ -96,7 +96,7 @@ fn subtract(&mut self, other: &HybridBitSet<T>) {
}
}
/// Define the domain of a dataflow problem.
/// Defines the domain of a dataflow problem.
///
/// 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.
@ -113,12 +113,12 @@ pub trait AnalysisDomain<'tcx> {
/// suitable as part of a filename.
const NAME: &'static str;
/// The initial value of the dataflow state upon entry to each basic block.
/// Returns the initial value of the dataflow state upon entry to each basic block.
fn bottom_value(&self, body: &mir::Body<'tcx>) -> Self::Domain;
/// Mutates the initial value of the dataflow state upon entry to the `START_BLOCK`.
///
/// For backward analyses, initial state besides the bottom value is not yet supported. Trying
/// For backward analyses, initial state (besides the bottom value) is not yet supported. Trying
/// to mutate the initial state will result in a panic.
//
// FIXME: For backward dataflow analyses, the initial state should be applied to every basic
@ -155,9 +155,9 @@ fn apply_statement_effect(
/// Updates the current dataflow state with an effect that occurs immediately *before* the
/// given statement.
///
/// This method is useful if the consumer of the results of this analysis needs only to observe
/// This method is useful if the consumer of the results of this analysis only needs to observe
/// *part* of the effect of a statement (e.g. for two-phase borrows). As a general rule,
/// analyses should not implement this without implementing `apply_statement_effect`.
/// analyses should not implement this without also implementing `apply_statement_effect`.
fn apply_before_statement_effect(
&self,
_state: &mut Self::Domain,
@ -184,7 +184,7 @@ fn apply_terminator_effect(
///
/// This method is useful if the consumer of the results of this analysis needs only to observe
/// *part* of the effect of a terminator (e.g. for two-phase borrows). As a general rule,
/// analyses should not implement this without implementing `apply_terminator_effect`.
/// analyses should not implement this without also implementing `apply_terminator_effect`.
fn apply_before_terminator_effect(
&self,
_state: &mut Self::Domain,