rust/src/librustc/infer/error_reporting/nice_region_error/mod.rs

92 lines
3.3 KiB
Rust

use crate::infer::lexical_region_resolve::RegionResolutionError;
use crate::infer::lexical_region_resolve::RegionResolutionError::*;
use crate::infer::InferCtxt;
use crate::ty::{self, TyCtxt};
use crate::util::common::ErrorReported;
use rustc_errors::DiagnosticBuilder;
use rustc_span::source_map::Span;
mod different_lifetimes;
mod find_anon_type;
mod named_anon_conflict;
mod outlives_closure;
mod placeholder_error;
mod static_impl_trait;
mod trait_impl_difference;
mod util;
impl<'cx, 'tcx> InferCtxt<'cx, 'tcx> {
pub fn try_report_nice_region_error(&self, error: &RegionResolutionError<'tcx>) -> bool {
match *error {
ConcreteFailure(..) | SubSupConflict(..) => {}
_ => return false, // inapplicable
}
if let Some(tables) = self.in_progress_tables {
let tables = tables.borrow();
NiceRegionError::new(self, error.clone(), Some(&tables)).try_report().is_some()
} else {
NiceRegionError::new(self, error.clone(), None).try_report().is_some()
}
}
}
pub struct NiceRegionError<'cx, 'tcx> {
infcx: &'cx InferCtxt<'cx, 'tcx>,
error: Option<RegionResolutionError<'tcx>>,
regions: Option<(Span, ty::Region<'tcx>, ty::Region<'tcx>)>,
tables: Option<&'cx ty::TypeckTables<'tcx>>,
}
impl<'cx, 'tcx> NiceRegionError<'cx, 'tcx> {
pub fn new(
infcx: &'cx InferCtxt<'cx, 'tcx>,
error: RegionResolutionError<'tcx>,
tables: Option<&'cx ty::TypeckTables<'tcx>>,
) -> Self {
Self { infcx, error: Some(error), regions: None, tables }
}
pub fn new_from_span(
infcx: &'cx InferCtxt<'cx, 'tcx>,
span: Span,
sub: ty::Region<'tcx>,
sup: ty::Region<'tcx>,
tables: Option<&'cx ty::TypeckTables<'tcx>>,
) -> Self {
Self { infcx, error: None, regions: Some((span, sub, sup)), tables }
}
fn tcx(&self) -> TyCtxt<'tcx> {
self.infcx.tcx
}
pub fn try_report_from_nll(&self) -> Option<DiagnosticBuilder<'cx>> {
// Due to the improved diagnostics returned by the MIR borrow checker, only a subset of
// the nice region errors are required when running under the MIR borrow checker.
self.try_report_named_anon_conflict().or_else(|| self.try_report_placeholder_conflict())
}
pub fn try_report(&self) -> Option<ErrorReported> {
self.try_report_from_nll()
.map(|mut diag| {
diag.emit();
ErrorReported
})
.or_else(|| self.try_report_anon_anon_conflict())
.or_else(|| self.try_report_outlives_closure())
.or_else(|| self.try_report_static_impl_trait())
.or_else(|| self.try_report_impl_not_conforming_to_trait())
}
pub fn regions(&self) -> (Span, ty::Region<'tcx>, ty::Region<'tcx>) {
match (&self.error, self.regions) {
(Some(ConcreteFailure(origin, sub, sup)), None) => (origin.span(), sub, sup),
(Some(SubSupConflict(_, _, origin, sub, _, sup)), None) => (origin.span(), sub, sup),
(None, Some((span, sub, sup))) => (span, sub, sup),
(Some(_), Some(_)) => panic!("incorrectly built NiceRegionError"),
_ => panic!("trying to report on an incorrect lifetime failure"),
}
}
}