rustc_trait_selection/error_reporting/infer/nice_region_error/
named_anon_conflict.rs1use rustc_errors::Diag;
5use rustc_middle::ty;
6use rustc_span::kw;
7use tracing::debug;
8
9use crate::error_reporting::infer::nice_region_error::NiceRegionError;
10use crate::error_reporting::infer::nice_region_error::find_anon_type::find_anon_type;
11use crate::errors::ExplicitLifetimeRequired;
12
13impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
14 pub(super) fn try_report_named_anon_conflict(&self) -> Option<Diag<'tcx>> {
17 let (span, sub, sup) = self.regions()?;
18
19 debug!(
20 "try_report_named_anon_conflict(sub={:?}, sup={:?}, error={:?})",
21 sub, sup, self.error,
22 );
23
24 let (named, anon, anon_param_info, region_info) = if sub.has_name()
31 && let Some(region_info) = self.tcx().is_suitable_region(self.generic_param_scope, sup)
32 && let Some(anon_param_info) = self.find_param_with_region(sup, sub)
33 {
34 (sub, sup, anon_param_info, region_info)
35 } else if sup.has_name()
36 && let Some(region_info) = self.tcx().is_suitable_region(self.generic_param_scope, sub)
37 && let Some(anon_param_info) = self.find_param_with_region(sub, sup)
38 {
39 (sup, sub, anon_param_info, region_info)
40 } else {
41 return None; };
43
44 if named.is_static() {
47 return None;
48 }
49
50 debug!("try_report_named_anon_conflict: named = {:?}", named);
51 debug!("try_report_named_anon_conflict: anon_param_info = {:?}", anon_param_info);
52 debug!("try_report_named_anon_conflict: region_info = {:?}", region_info);
53
54 let param = anon_param_info.param;
55 let new_ty = anon_param_info.param_ty;
56 let new_ty_span = anon_param_info.param_ty_span;
57 let is_first = anon_param_info.is_first;
58 let scope_def_id = region_info.scope;
59 let is_impl_item = region_info.is_impl_item;
60
61 match anon_param_info.kind {
62 ty::LateParamRegionKind::Named(_, kw::UnderscoreLifetime)
63 | ty::LateParamRegionKind::Anon(_) => {}
64 _ => {
65 debug!("try_report_named_anon_conflict: not an anonymous region");
67 return None;
68 }
69 }
70
71 if is_impl_item {
72 debug!("try_report_named_anon_conflict: impl item, bail out");
73 return None;
74 }
75
76 if find_anon_type(self.tcx(), self.generic_param_scope, anon).is_some()
77 && self.is_self_anon(is_first, scope_def_id)
78 {
79 return None;
80 }
81 let named = named.to_string();
82 let err = match param.pat.simple_ident() {
83 Some(simple_ident) => ExplicitLifetimeRequired::WithIdent {
84 span,
85 simple_ident,
86 named,
87 new_ty_span,
88 new_ty,
89 },
90 None => ExplicitLifetimeRequired::WithParamType { span, named, new_ty_span, new_ty },
91 };
92 Some(self.tcx().sess.dcx().create_err(err))
93 }
94}