Struct cranelift_codegen::flowgraph::ControlFlowGraph

pub struct ControlFlowGraph { /* fields omitted */ }

The Control Flow Graph maintains a mapping of ebbs to their predecessors and successors where predecessors are basic blocks and successors are extended basic blocks.

Methods

impl ControlFlowGraph

pub fn new() -> Self

Allocate a new blank control flow graph.

pub fn clear(&mut self)

Clear all data structures in this control flow graph.

pub fn with_function(func: &Function) -> Self

Allocate and compute the control flow graph for func.

pub fn compute(&mut self, func: &Function)

Compute the control flow graph of func.

This will clear and overwrite any information already stored in this data structure.

pub fn recompute_ebb(&mut self, func: &Function, ebb: Ebb)

Recompute the control flow graph of ebb.

This is for use after modifying instructions within a specific EBB. It recomputes all edges from ebb while leaving edges to ebb intact. Its functionality a subset of that of the more expensive compute, and should be used when we know we don't need to recompute the CFG from scratch, but rather that our changes have been restricted to specific EBBs.

Important traits for PredIter<'a>

impl<'a> Iterator for PredIter<'a> type Item = BasicBlock;

pub fn pred_iter(&self, ebb: Ebb) -> PredIter

Get an iterator over the CFG predecessors to ebb.

pub fn succ_iter(&self, ebb: Ebb) -> SuccIter

Get an iterator over the CFG successors to ebb.

pub fn is_valid(&self) -> bool

Check if the CFG is in a valid state.

Note that this doesn't perform any kind of validity checks. It simply checks if the compute() method has been called since the last clear(). It does not check that the CFG is consistent with the function.