Struct EqualityAnalysis 

pub struct EqualityAnalysis<'a, 'db> { /* private fields */ }

Variable equality analysis.

This analyzer tracks snapshot/desnap, box/unbox, and array construct relationships as data flows through the program. At merge points (after match arms converge), we conservatively intersect the equivalence classes, keeping only equalities that hold on all paths.

Implementations

impl<'a, 'db> EqualityAnalysis<'a, 'db>

pub fn new(db: &'db dyn Database, lowered: &'a Lowered<'db>) -> Self

Creates a new equality analysis instance.

pub fn analyze( db: &'db dyn Database, lowered: &'a Lowered<'db>, ) -> Vec<Option<EqualityState<'db>>>

Runs equality analysis on a lowered function. Returns the equality state at the exit of each block.

Trait Implementations

impl<'db, 'a> DataflowAnalyzer<'db, 'a> for EqualityAnalysis<'a, 'db>

const DIRECTION: Direction = Direction::Forward

The direction of this analysis.

type Info = EqualityState<'db>

The analysis state/info type.

fn initial_info( &mut self, _block_id: BlockId, _block_end: &'a BlockEnd<'db>, ) -> Self::Info

Create the initial analysis state at a terminal block.

fn merge( &mut self, _lowered: &Lowered<'db>, _statement_location: StatementLocation, info1: Self::Info, info2: Self::Info, ) -> Self::Info

Merge/join states from multiple control flow paths. Called at join points (match merge for backward, block entry for forward).

fn transfer_stmt( &mut self, info: &mut Self::Info, _statement_location: StatementLocation, stmt: &'a Statement<'db>, )

Transfer function for a single statement.

fn transfer_edge( &mut self, info: &Self::Info, edge: &Edge<'db, 'a>, ) -> Self::Info

Transfer state along a CFG edge. Called when traversing between blocks via control flow edges.

fn transfer_block( &mut self, info: &mut Self::Info, block_id: BlockId, block: &'a Block<'db>, )

Transfer function for an entire block.

fn visit_block_start( &mut self, _info: &mut Self::Info, _block_id: BlockId, _block: &Block<'db>, )

Called when entering a block during traversal (before transfer_block).

fn block_entry_location( &self, lowered: &Lowered<'db>, block_id: BlockId, ) -> LocationId<'db>

Block entry location. For Backward it is the merge location. For Forward it is the block entry location, if there is a statement. If not statement exists it will look at block end. This might recurse to next block if we have a goto with no remappings.