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Diffstat (limited to '')
| -rw-r--r-- | compiler/rustc_infer/src/errors/note_and_explain.rs | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/compiler/rustc_infer/src/errors/note_and_explain.rs b/compiler/rustc_infer/src/errors/note_and_explain.rs new file mode 100644 index 000000000..7e051835b --- /dev/null +++ b/compiler/rustc_infer/src/errors/note_and_explain.rs @@ -0,0 +1,172 @@ +use crate::infer::error_reporting::nice_region_error::find_anon_type; +use rustc_errors::{self, fluent, AddSubdiagnostic, IntoDiagnosticArg}; +use rustc_middle::ty::{self, TyCtxt}; +use rustc_span::{symbol::kw, Span}; + +#[derive(Default)] +struct DescriptionCtx<'a> { + span: Option<Span>, + kind: &'a str, + arg: String, + num_arg: u32, +} + +impl<'a> DescriptionCtx<'a> { + fn new<'tcx>( + tcx: TyCtxt<'tcx>, + region: ty::Region<'tcx>, + alt_span: Option<Span>, + ) -> Option<Self> { + let mut me = DescriptionCtx::default(); + me.span = alt_span; + match *region { + ty::ReEarlyBound(_) | ty::ReFree(_) => { + return Self::from_early_bound_and_free_regions(tcx, region); + } + ty::ReStatic => { + me.kind = "restatic"; + } + + ty::RePlaceholder(_) => return None, + + // FIXME(#13998) RePlaceholder should probably print like + // ReFree rather than dumping Debug output on the user. + // + // We shouldn't really be having unification failures with ReVar + // and ReLateBound though. + ty::ReVar(_) | ty::ReLateBound(..) | ty::ReErased => { + me.kind = "revar"; + me.arg = format!("{:?}", region); + } + }; + Some(me) + } + + fn from_early_bound_and_free_regions<'tcx>( + tcx: TyCtxt<'tcx>, + region: ty::Region<'tcx>, + ) -> Option<Self> { + let mut me = DescriptionCtx::default(); + let scope = region.free_region_binding_scope(tcx).expect_local(); + match *region { + ty::ReEarlyBound(ref br) => { + let mut sp = tcx.def_span(scope); + if let Some(param) = + tcx.hir().get_generics(scope).and_then(|generics| generics.get_named(br.name)) + { + sp = param.span; + } + if br.has_name() { + me.kind = "as_defined"; + me.arg = br.name.to_string(); + } else { + me.kind = "as_defined_anon"; + }; + me.span = Some(sp) + } + ty::ReFree(ref fr) => { + if !fr.bound_region.is_named() + && let Some((ty, _)) = find_anon_type(tcx, region, &fr.bound_region) + { + me.kind = "defined_here"; + me.span = Some(ty.span); + } else { + match fr.bound_region { + ty::BoundRegionKind::BrNamed(_, name) => { + let mut sp = tcx.def_span(scope); + if let Some(param) = + tcx.hir().get_generics(scope).and_then(|generics| generics.get_named(name)) + { + sp = param.span; + } + if name == kw::UnderscoreLifetime { + me.kind = "as_defined_anon"; + } else { + me.kind = "as_defined"; + me.arg = name.to_string(); + }; + me.span = Some(sp); + } + ty::BrAnon(idx) => { + me.kind = "anon_num_here"; + me.num_arg = idx+1; + me.span = Some(tcx.def_span(scope)); + }, + _ => { + me.kind = "defined_here_reg"; + me.arg = region.to_string(); + me.span = Some(tcx.def_span(scope)); + }, + } + } + } + _ => bug!(), + } + Some(me) + } + + fn add_to(self, diag: &mut rustc_errors::Diagnostic) { + diag.set_arg("desc_kind", self.kind); + diag.set_arg("desc_arg", self.arg); + diag.set_arg("desc_num_arg", self.num_arg); + } +} + +pub enum PrefixKind { + Empty, +} + +pub enum SuffixKind { + Continues, +} + +impl IntoDiagnosticArg for PrefixKind { + fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> { + let kind = match self { + Self::Empty => "empty", + } + .into(); + rustc_errors::DiagnosticArgValue::Str(kind) + } +} + +impl IntoDiagnosticArg for SuffixKind { + fn into_diagnostic_arg(self) -> rustc_errors::DiagnosticArgValue<'static> { + let kind = match self { + Self::Continues => "continues", + } + .into(); + rustc_errors::DiagnosticArgValue::Str(kind) + } +} + +pub struct RegionExplanation<'a> { + desc: DescriptionCtx<'a>, + prefix: PrefixKind, + suffix: SuffixKind, +} + +impl RegionExplanation<'_> { + pub fn new<'tcx>( + tcx: TyCtxt<'tcx>, + region: ty::Region<'tcx>, + alt_span: Option<Span>, + prefix: PrefixKind, + suffix: SuffixKind, + ) -> Option<Self> { + Some(Self { desc: DescriptionCtx::new(tcx, region, alt_span)?, prefix, suffix }) + } +} + +impl AddSubdiagnostic for RegionExplanation<'_> { + fn add_to_diagnostic(self, diag: &mut rustc_errors::Diagnostic) { + if let Some(span) = self.desc.span { + diag.span_note(span, fluent::infer::region_explanation); + } else { + diag.note(fluent::infer::region_explanation); + } + self.desc.add_to(diag); + diag.set_arg("pref_kind", self.prefix); + diag.set_arg("suff_kind", self.suffix); + } +} |