1 use rustc::ty::subst::SubstsRef;
2 use rustc::ty::{self, ClosureSubsts, GeneratorSubsts, Ty, TypeFoldable};
3 use rustc::mir::{Location, Body};
4 use rustc::mir::visit::{MutVisitor, TyContext};
5 use rustc::infer::{InferCtxt, NLLRegionVariableOrigin};
7 /// Replaces all free regions appearing in the MIR with fresh
8 /// inference variables, returning the number of variables created.
9 pub fn renumber_mir<'tcx>(infcx: &InferCtxt<'_, '_, 'tcx>, mir: &mut Body<'tcx>) {
10 debug!("renumber_mir()");
11 debug!("renumber_mir: mir.arg_count={:?}", mir.arg_count);
13 let mut visitor = NLLVisitor { infcx };
14 visitor.visit_body(mir);
17 /// Replaces all regions appearing in `value` with fresh inference
19 pub fn renumber_regions<'tcx, T>(
20 infcx: &InferCtxt<'_, '_, 'tcx>,
24 T: TypeFoldable<'tcx>,
26 debug!("renumber_regions(value={:?})", value);
30 .fold_regions(value, &mut false, |_region, _depth| {
31 let origin = NLLRegionVariableOrigin::Existential;
32 infcx.next_nll_region_var(origin)
36 struct NLLVisitor<'a, 'gcx: 'a + 'tcx, 'tcx: 'a> {
37 infcx: &'a InferCtxt<'a, 'gcx, 'tcx>,
40 impl<'a, 'gcx, 'tcx> NLLVisitor<'a, 'gcx, 'tcx> {
41 fn renumber_regions<T>(&mut self, value: &T) -> T
43 T: TypeFoldable<'tcx>,
45 renumber_regions(self.infcx, value)
49 impl<'a, 'gcx, 'tcx> MutVisitor<'tcx> for NLLVisitor<'a, 'gcx, 'tcx> {
50 fn visit_body(&mut self, mir: &mut Body<'tcx>) {
51 for promoted in mir.promoted.iter_mut() {
52 self.visit_body(promoted);
58 fn visit_ty(&mut self, ty: &mut Ty<'tcx>, ty_context: TyContext) {
59 debug!("visit_ty(ty={:?}, ty_context={:?})", ty, ty_context);
61 *ty = self.renumber_regions(ty);
63 debug!("visit_ty: ty={:?}", ty);
66 fn visit_substs(&mut self, substs: &mut SubstsRef<'tcx>, location: Location) {
67 debug!("visit_substs(substs={:?}, location={:?})", substs, location);
69 *substs = self.renumber_regions(&{ *substs });
71 debug!("visit_substs: substs={:?}", substs);
74 fn visit_region(&mut self, region: &mut ty::Region<'tcx>, location: Location) {
75 debug!("visit_region(region={:?}, location={:?})", region, location);
77 let old_region = *region;
78 *region = self.renumber_regions(&old_region);
80 debug!("visit_region: region={:?}", region);
83 fn visit_const(&mut self, constant: &mut &'tcx ty::Const<'tcx>, _location: Location) {
84 *constant = self.renumber_regions(&*constant);
87 fn visit_generator_substs(&mut self,
88 substs: &mut GeneratorSubsts<'tcx>,
91 "visit_generator_substs(substs={:?}, location={:?})",
96 *substs = self.renumber_regions(substs);
98 debug!("visit_generator_substs: substs={:?}", substs);
101 fn visit_closure_substs(&mut self, substs: &mut ClosureSubsts<'tcx>, location: Location) {
103 "visit_closure_substs(substs={:?}, location={:?})",
108 *substs = self.renumber_regions(substs);
110 debug!("visit_closure_substs: substs={:?}", substs);