| //! Manages the dataflow bits required for borrowck. |
| //! |
| //! FIXME: this might be better as a "generic" fixed-point combinator, |
| //! but is not as ugly as it is right now. |
| |
| use rustc::mir::{BasicBlock, Location}; |
| use rustc::ty::RegionVid; |
| use rustc_data_structures::bit_set::BitIter; |
| |
| use crate::borrow_check::location::LocationIndex; |
| |
| use polonius_engine::Output; |
| |
| use crate::dataflow::move_paths::indexes::BorrowIndex; |
| use crate::dataflow::move_paths::HasMoveData; |
| use crate::dataflow::Borrows; |
| use crate::dataflow::EverInitializedPlaces; |
| use crate::dataflow::{FlowAtLocation, FlowsAtLocation}; |
| use crate::dataflow::MaybeUninitializedPlaces; |
| use either::Either; |
| use std::fmt; |
| use std::rc::Rc; |
| |
| // (forced to be `pub` due to its use as an associated type below.) |
| crate struct Flows<'b, 'gcx: 'tcx, 'tcx: 'b> { |
| borrows: FlowAtLocation<'tcx, Borrows<'b, 'gcx, 'tcx>>, |
| pub uninits: FlowAtLocation<'tcx, MaybeUninitializedPlaces<'b, 'gcx, 'tcx>>, |
| pub ever_inits: FlowAtLocation<'tcx, EverInitializedPlaces<'b, 'gcx, 'tcx>>, |
| |
| /// Polonius Output |
| pub polonius_output: Option<Rc<Output<RegionVid, BorrowIndex, LocationIndex>>>, |
| } |
| |
| impl<'b, 'gcx, 'tcx> Flows<'b, 'gcx, 'tcx> { |
| crate fn new( |
| borrows: FlowAtLocation<'tcx, Borrows<'b, 'gcx, 'tcx>>, |
| uninits: FlowAtLocation<'tcx, MaybeUninitializedPlaces<'b, 'gcx, 'tcx>>, |
| ever_inits: FlowAtLocation<'tcx, EverInitializedPlaces<'b, 'gcx, 'tcx>>, |
| polonius_output: Option<Rc<Output<RegionVid, BorrowIndex, LocationIndex>>>, |
| ) -> Self { |
| Flows { |
| borrows, |
| uninits, |
| ever_inits, |
| polonius_output, |
| } |
| } |
| |
| crate fn borrows_in_scope( |
| &self, |
| location: LocationIndex, |
| ) -> impl Iterator<Item = BorrowIndex> + '_ { |
| if let Some(ref polonius) = self.polonius_output { |
| Either::Left(polonius.errors_at(location).iter().cloned()) |
| } else { |
| Either::Right(self.borrows.iter_incoming()) |
| } |
| } |
| |
| crate fn with_outgoing_borrows(&self, op: impl FnOnce(BitIter<'_, BorrowIndex>)) { |
| self.borrows.with_iter_outgoing(op) |
| } |
| } |
| |
| macro_rules! each_flow { |
| ($this:ident, $meth:ident($arg:ident)) => { |
| FlowAtLocation::$meth(&mut $this.borrows, $arg); |
| FlowAtLocation::$meth(&mut $this.uninits, $arg); |
| FlowAtLocation::$meth(&mut $this.ever_inits, $arg); |
| }; |
| } |
| |
| impl<'b, 'gcx, 'tcx> FlowsAtLocation for Flows<'b, 'gcx, 'tcx> { |
| fn reset_to_entry_of(&mut self, bb: BasicBlock) { |
| each_flow!(self, reset_to_entry_of(bb)); |
| } |
| |
| fn reset_to_exit_of(&mut self, bb: BasicBlock) { |
| each_flow!(self, reset_to_exit_of(bb)); |
| } |
| |
| fn reconstruct_statement_effect(&mut self, location: Location) { |
| each_flow!(self, reconstruct_statement_effect(location)); |
| } |
| |
| fn reconstruct_terminator_effect(&mut self, location: Location) { |
| each_flow!(self, reconstruct_terminator_effect(location)); |
| } |
| |
| fn apply_local_effect(&mut self, location: Location) { |
| each_flow!(self, apply_local_effect(location)); |
| } |
| } |
| |
| impl<'b, 'gcx, 'tcx> fmt::Display for Flows<'b, 'gcx, 'tcx> { |
| fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result { |
| let mut s = String::new(); |
| |
| s.push_str("borrows in effect: ["); |
| let mut saw_one = false; |
| self.borrows.each_state_bit(|borrow| { |
| if saw_one { |
| s.push_str(", "); |
| }; |
| saw_one = true; |
| let borrow_data = &self.borrows.operator().borrows()[borrow]; |
| s.push_str(&borrow_data.to_string()); |
| }); |
| s.push_str("] "); |
| |
| s.push_str("borrows generated: ["); |
| let mut saw_one = false; |
| self.borrows.each_gen_bit(|borrow| { |
| if saw_one { |
| s.push_str(", "); |
| }; |
| saw_one = true; |
| let borrow_data = &self.borrows.operator().borrows()[borrow]; |
| s.push_str(&borrow_data.to_string()); |
| }); |
| s.push_str("] "); |
| |
| s.push_str("uninits: ["); |
| let mut saw_one = false; |
| self.uninits.each_state_bit(|mpi_uninit| { |
| if saw_one { |
| s.push_str(", "); |
| }; |
| saw_one = true; |
| let move_path = &self.uninits.operator().move_data().move_paths[mpi_uninit]; |
| s.push_str(&move_path.to_string()); |
| }); |
| s.push_str("] "); |
| |
| s.push_str("ever_init: ["); |
| let mut saw_one = false; |
| self.ever_inits.each_state_bit(|mpi_ever_init| { |
| if saw_one { |
| s.push_str(", "); |
| }; |
| saw_one = true; |
| let ever_init = &self.ever_inits.operator().move_data().inits[mpi_ever_init]; |
| s.push_str(&format!("{:?}", ever_init)); |
| }); |
| s.push_str("]"); |
| |
| fmt::Display::fmt(&s, fmt) |
| } |
| } |