compiler/rustc_mir_transform/src/remove_false_edges.rs

   1 use rustc_middle::mir::{Body, TerminatorKind};
   2 use rustc_middle::ty::TyCtxt;
   3
   4 use crate::MirPass;
   5
   6 /// Removes `FalseEdge` and `FalseUnwind` terminators from the MIR.
   7 ///
   8 /// These are only needed for borrow checking, and can be removed afterwards.
   9 ///
  10 /// FIXME: This should probably have its own MIR phase.
  11 pub struct RemoveFalseEdges;
  12
  13 impl<'tcx> MirPass<'tcx> for RemoveFalseEdges {
  14     fn run_pass(&self, _: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
  15         for block in body.basic_blocks_mut() {
  16             let terminator = block.terminator_mut();
  17             terminator.kind = match terminator.kind {
  18                 TerminatorKind::FalseEdge { real_target, .. } => {
  19                     TerminatorKind::Goto { target: real_target }
  20                 }
  21                 TerminatorKind::FalseUnwind { real_target, .. } => {
  22                     TerminatorKind::Goto { target: real_target }
  23                 }
  24
  25                 _ => continue,
  26             }
  27         }
  28     }
  29 }