Class PostOrder

src/debug_utils/postorder.rs:17–32

Post-order traversal of the control flow graph. This also doubles as a reachability check to determine whether a basic block is reachable from any entry point.

/// This also doubles as a reachability check to determine whether a basic block
/// is reachable from any entry point.
pub struct PostOrder {
    /// Stack used to compute the post-order.
    stack: Vec<(Visit, Block)>,

    /// List of basic blocks in CFG post-order.
    postorder: Vec<Block>,

    /// Number of a basic block in the postorder traversal of the control
    /// flow graph. This number is guranteed to be monotonically increasing for
    /// each node of the graph but may not be contiguous.
    ///
    /// Unreahcable blocks get a value of `UNREACHABLE` (0). `SEEN` is used as a
    /// marker during processing, but this is later replaced with the actual
    /// number.
    po_number: SecondaryMap<Block, u32>,
}

/// Special value for `po_number` which indicates an unreachable block.
///