rustc_trait_selection/error_reporting/infer/nice_region_error/
mod.rs

1use rustc_errors::{Diag, ErrorGuaranteed};
2use rustc_hir::def_id::LocalDefId;
3use rustc_middle::ty::{self, TyCtxt};
4use rustc_span::Span;
5
6use crate::error_reporting::TypeErrCtxt;
7use crate::infer::RegionResolutionError;
8
9mod different_lifetimes;
10pub mod find_anon_type;
11mod mismatched_static_lifetime;
12mod named_anon_conflict;
13pub(crate) mod placeholder_error;
14mod placeholder_relation;
15mod static_impl_trait;
16mod trait_impl_difference;
17mod util;
18
19pub use different_lifetimes::suggest_adding_lifetime_params;
20pub use find_anon_type::find_anon_type;
21pub use static_impl_trait::{HirTraitObjectVisitor, TraitObjectVisitor, suggest_new_region_bound};
22pub use util::find_param_with_region;
23
24impl<'cx, 'tcx> TypeErrCtxt<'cx, 'tcx> {
25    pub fn try_report_nice_region_error(
26        &'cx self,
27        generic_param_scope: LocalDefId,
28        error: &RegionResolutionError<'tcx>,
29    ) -> Option<ErrorGuaranteed> {
30        NiceRegionError::new(self, generic_param_scope, error.clone()).try_report()
31    }
32}
33
34pub struct NiceRegionError<'cx, 'tcx> {
35    cx: &'cx TypeErrCtxt<'cx, 'tcx>,
36    /// The innermost definition that introduces generic parameters that may be involved in
37    /// the region errors we are dealing with.
38    generic_param_scope: LocalDefId,
39    error: Option<RegionResolutionError<'tcx>>,
40    regions: Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)>,
41}
42
43impl<'cx, 'tcx> NiceRegionError<'cx, 'tcx> {
44    pub fn new(
45        cx: &'cx TypeErrCtxt<'cx, 'tcx>,
46        generic_param_scope: LocalDefId,
47        error: RegionResolutionError<'tcx>,
48    ) -> Self {
49        Self { cx, error: Some(error), regions: None, generic_param_scope }
50    }
51
52    pub fn new_from_span(
53        cx: &'cx TypeErrCtxt<'cx, 'tcx>,
54        generic_param_scope: LocalDefId,
55        span: Span,
56        sub: ty::Region<'tcx>,
57        sup: ty::Region<'tcx>,
58    ) -> Self {
59        Self { cx, error: None, regions: Some((span, sub, sup)), generic_param_scope }
60    }
61
62    fn tcx(&self) -> TyCtxt<'tcx> {
63        self.cx.tcx
64    }
65
66    pub fn try_report_from_nll(&self) -> Option<Diag<'tcx>> {
67        // Due to the improved diagnostics returned by the MIR borrow checker, only a subset of
68        // the nice region errors are required when running under the MIR borrow checker.
69        self.try_report_named_anon_conflict()
70            .or_else(|| self.try_report_placeholder_conflict())
71            .or_else(|| self.try_report_placeholder_relation())
72    }
73
74    pub fn try_report(&self) -> Option<ErrorGuaranteed> {
75        self.try_report_from_nll()
76            .map(|diag| diag.emit())
77            .or_else(|| self.try_report_impl_not_conforming_to_trait())
78            .or_else(|| self.try_report_anon_anon_conflict())
79            .or_else(|| self.try_report_static_impl_trait())
80            .or_else(|| self.try_report_mismatched_static_lifetime())
81    }
82
83    pub(super) fn regions(&self) -> Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)> {
84        match (&self.error, self.regions) {
85            (Some(RegionResolutionError::ConcreteFailure(origin, sub, sup)), None) => {
86                Some((origin.span(), *sub, *sup))
87            }
88            (Some(RegionResolutionError::SubSupConflict(_, _, origin, sub, _, sup, _)), None) => {
89                Some((origin.span(), *sub, *sup))
90            }
91            (None, Some((span, sub, sup))) => Some((span, sub, sup)),
92            _ => None,
93        }
94    }
95}
rustc_trait_selection/error_reporting/infer/nice_region_error/mod.rs

rustc_trait_selection/error_reporting/infer/nice_region_error/
mod.rs
