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>, body: &mut Body<'tcx>) {
10 debug!("renumber_mir()");
11 debug!("renumber_mir: body.arg_count={:?}", body.arg_count);
13 let mut visitor = NLLVisitor { infcx };
14 visitor.visit_body(body);
17 /// Replaces all regions appearing in `value` with fresh inference
19 pub fn renumber_regions<'tcx, T>(infcx: &InferCtxt<'_, 'tcx>, value: &T) -> T
21 T: TypeFoldable<'tcx>,
23 debug!("renumber_regions(value={:?})", value);
27 .fold_regions(value, &mut false, |_region, _depth| {
28 let origin = NLLRegionVariableOrigin::Existential;
29 infcx.next_nll_region_var(origin)
33 struct NLLVisitor<'a, 'tcx> {
34 infcx: &'a InferCtxt<'a, 'tcx>,
37 impl<'a, 'tcx> NLLVisitor<'a, 'tcx> {
38 fn renumber_regions<T>(&mut self, value: &T) -> T
40 T: TypeFoldable<'tcx>,
42 renumber_regions(self.infcx, value)
46 impl<'a, 'tcx> MutVisitor<'tcx> for NLLVisitor<'a, 'tcx> {
47 fn visit_body(&mut self, body: &mut Body<'tcx>) {
48 for promoted in body.promoted.iter_mut() {
49 self.visit_body(promoted);
52 self.super_body(body);
55 fn visit_ty(&mut self, ty: &mut Ty<'tcx>, ty_context: TyContext) {
56 debug!("visit_ty(ty={:?}, ty_context={:?})", ty, ty_context);
58 *ty = self.renumber_regions(ty);
60 debug!("visit_ty: ty={:?}", ty);
63 fn visit_substs(&mut self, substs: &mut SubstsRef<'tcx>, location: Location) {
64 debug!("visit_substs(substs={:?}, location={:?})", substs, location);
66 *substs = self.renumber_regions(&{ *substs });
68 debug!("visit_substs: substs={:?}", substs);
71 fn visit_region(&mut self, region: &mut ty::Region<'tcx>, location: Location) {
72 debug!("visit_region(region={:?}, location={:?})", region, location);
74 let old_region = *region;
75 *region = self.renumber_regions(&old_region);
77 debug!("visit_region: region={:?}", region);
80 fn visit_const(&mut self, constant: &mut &'tcx ty::Const<'tcx>, _location: Location) {
81 *constant = self.renumber_regions(&*constant);
84 fn visit_generator_substs(&mut self,
85 substs: &mut GeneratorSubsts<'tcx>,
88 "visit_generator_substs(substs={:?}, location={:?})",
93 *substs = self.renumber_regions(substs);
95 debug!("visit_generator_substs: substs={:?}", substs);
98 fn visit_closure_substs(&mut self, substs: &mut ClosureSubsts<'tcx>, location: Location) {
100 "visit_closure_substs(substs={:?}, location={:?})",
105 *substs = self.renumber_regions(substs);
107 debug!("visit_closure_substs: substs={:?}", substs);