diff --git a/compiler/rustc_middle/src/ty/print/pretty.rs b/compiler/rustc_middle/src/ty/print/pretty.rs index f69ac0768204..ad76422ef661 100644 --- a/compiler/rustc_middle/src/ty/print/pretty.rs +++ b/compiler/rustc_middle/src/ty/print/pretty.rs @@ -2055,7 +2055,14 @@ struct RegionFolder<'a, 'tcx> { tcx: TyCtxt<'tcx>, current_index: ty::DebruijnIndex, region_map: BTreeMap>, - name: &'a mut (dyn FnMut(ty::BoundRegion) -> ty::Region<'tcx> + 'a), + name: &'a mut ( + dyn FnMut( + Option, + ty::DebruijnIndex, + ty::BoundRegion, + ) -> ty::Region<'tcx> + + 'a + ), } impl<'a, 'tcx> ty::TypeFolder<'tcx> for RegionFolder<'a, 'tcx> { @@ -2086,7 +2093,9 @@ impl<'a, 'tcx> ty::TypeFolder<'tcx> for RegionFolder<'a, 'tcx> { fn fold_region(&mut self, r: ty::Region<'tcx>) -> ty::Region<'tcx> { let name = &mut self.name; let region = match *r { - ty::ReLateBound(_, br) => *self.region_map.entry(br).or_insert_with(|| name(br)), + ty::ReLateBound(db, br) => { + *self.region_map.entry(br).or_insert_with(|| name(Some(db), self.current_index, br)) + } ty::RePlaceholder(ty::PlaceholderRegion { name: kind, .. }) => { // If this is an anonymous placeholder, don't rename. Otherwise, in some // async fns, we get a `for<'r> Send` bound @@ -2095,7 +2104,10 @@ impl<'a, 'tcx> ty::TypeFolder<'tcx> for RegionFolder<'a, 'tcx> { _ => { // Index doesn't matter, since this is just for naming and these never get bound let br = ty::BoundRegion { var: ty::BoundVar::from_u32(0), kind }; - *self.region_map.entry(br).or_insert_with(|| name(br)) + *self + .region_map + .entry(br) + .or_insert_with(|| name(None, self.current_index, br)) } } } @@ -2234,24 +2246,57 @@ impl<'tcx> FmtPrinter<'_, 'tcx> { }) } else { let tcx = self.tcx; - let mut name = |br: ty::BoundRegion| { - start_or_continue(&mut self, "for<", ", "); - let kind = match br.kind { + let mut name = |db: Option, + binder_level: ty::DebruijnIndex, + br: ty::BoundRegion| { + let (name, kind) = match br.kind { ty::BrAnon(_) | ty::BrEnv => { let name = next_name(&self); - do_continue(&mut self, name); - ty::BrNamed(CRATE_DEF_ID.to_def_id(), name) + + if let Some(db) = db { + if db > binder_level { + let kind = ty::BrNamed(CRATE_DEF_ID.to_def_id(), name); + return tcx.mk_region(ty::ReLateBound( + ty::INNERMOST, + ty::BoundRegion { var: br.var, kind }, + )); + } + } + + (name, ty::BrNamed(CRATE_DEF_ID.to_def_id(), name)) } ty::BrNamed(def_id, kw::UnderscoreLifetime) => { let name = next_name(&self); - do_continue(&mut self, name); - ty::BrNamed(def_id, name) + + if let Some(db) = db { + if db > binder_level { + let kind = ty::BrNamed(def_id, name); + return tcx.mk_region(ty::ReLateBound( + ty::INNERMOST, + ty::BoundRegion { var: br.var, kind }, + )); + } + } + + (name, ty::BrNamed(def_id, name)) } ty::BrNamed(_, name) => { - do_continue(&mut self, name); - br.kind + if let Some(db) = db { + if db > binder_level { + let kind = br.kind; + return tcx.mk_region(ty::ReLateBound( + ty::INNERMOST, + ty::BoundRegion { var: br.var, kind }, + )); + } + } + + (name, br.kind) } }; + + start_or_continue(&mut self, "for<", ", "); + do_continue(&mut self, name); tcx.mk_region(ty::ReLateBound(ty::INNERMOST, ty::BoundRegion { var: br.var, kind })) }; let mut folder = RegionFolder {