Automatically taint InferCtxt when errors are emitted

compiler/rustc_infer/src/infer/error_reporting/mod.rs

@@ -305,16 +305,17 @@ fn label_msg_span(
     }
 }
 
-#[instrument(level = "trace", skip(tcx))]
-pub fn unexpected_hidden_region_diagnostic<'tcx>(
-    tcx: TyCtxt<'tcx>,
+#[instrument(level = "trace", skip(infcx))]
+pub fn unexpected_hidden_region_diagnostic<'a, 'tcx>(
+    infcx: &'a InferCtxt<'tcx>,
     generic_param_scope: LocalDefId,
     span: Span,
     hidden_ty: Ty<'tcx>,
     hidden_region: ty::Region<'tcx>,
     opaque_ty_key: ty::OpaqueTypeKey<'tcx>,
-) -> Diag<'tcx> {
-    let mut err = tcx.dcx().create_err(errors::OpaqueCapturesLifetime {
+) -> Diag<'a> {
+    let tcx = infcx.tcx;
+    let mut err = infcx.dcx().create_err(errors::OpaqueCapturesLifetime {
         span,
         opaque_ty: Ty::new_opaque(tcx, opaque_ty_key.def_id.to_def_id(), opaque_ty_key.args),
         opaque_ty_span: tcx.def_span(opaque_ty_key.def_id),
@@ -2215,7 +2216,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
             span,
             self.type_error_additional_suggestions(&trace, terr),
         );
-        let mut diag = self.tcx.dcx().create_err(failure_code);
+        let mut diag = self.dcx().create_err(failure_code);
         self.note_type_err(&mut diag, &trace.cause, None, Some(trace.values), terr, false, false);
         diag
     }
@@ -2357,14 +2358,14 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
         origin: Option<SubregionOrigin<'tcx>>,
         bound_kind: GenericKind<'tcx>,
         sub: Region<'tcx>,
-    ) -> Diag<'tcx> {
+    ) -> Diag<'a> {
         if let Some(SubregionOrigin::CompareImplItemObligation {
             span,
             impl_item_def_id,
             trait_item_def_id,
         }) = origin
         {
-            return self.report_extra_impl_obligation(
+            return self.infcx.report_extra_impl_obligation(
                 span,
                 impl_item_def_id,
                 trait_item_def_id,
@@ -2790,7 +2791,7 @@ impl<'tcx> TypeRelation<TyCtxt<'tcx>> for SameTypeModuloInfer<'_, 'tcx> {
 }
 
 impl<'tcx> InferCtxt<'tcx> {
-    fn report_inference_failure(&self, var_origin: RegionVariableOrigin) -> Diag<'tcx> {
+    fn report_inference_failure(&self, var_origin: RegionVariableOrigin) -> Diag<'_> {
         let br_string = |br: ty::BoundRegionKind| {
             let mut s = match br {
                 ty::BrNamed(_, name) => name.to_string(),
@@ -2829,7 +2830,7 @@ impl<'tcx> InferCtxt<'tcx> {
         };
 
         struct_span_code_err!(
-            self.tcx.dcx(),
+            self.dcx(),
             var_origin.span(),
             E0495,
             "cannot infer an appropriate lifetime{} due to conflicting requirements",

compiler/rustc_infer/src/infer/error_reporting/note.rs

@@ -245,7 +245,7 @@ impl<'a, 'tcx> TypeErrCtxt<'a, 'tcx> {
                 })
             }
             infer::CompareImplItemObligation { span, impl_item_def_id, trait_item_def_id } => {
-                let mut err = self.report_extra_impl_obligation(
+                let mut err = self.infcx.report_extra_impl_obligation(
                     span,
                     impl_item_def_id,
                     trait_item_def_id,

compiler/rustc_infer/src/infer/mod.rs

@@ -685,7 +685,7 @@ impl<'tcx> InferOk<'tcx, ()> {
 
 impl<'tcx> InferCtxt<'tcx> {
     pub fn dcx(&self) -> DiagCtxtHandle<'_> {
-        self.tcx.dcx()
+        self.tcx.dcx().taintable_handle(&self.tainted_by_errors)
     }
 
     pub fn defining_opaque_types(&self) -> &'tcx ty::List<LocalDefId> {
@@ -1089,19 +1089,7 @@ impl<'tcx> InferCtxt<'tcx> {
     /// inference variables, regionck errors).
     #[must_use = "this method does not have any side effects"]
     pub fn tainted_by_errors(&self) -> Option<ErrorGuaranteed> {
-        if let Some(guar) = self.tainted_by_errors.get() {
-            Some(guar)
-        } else if self.dcx().err_count_excluding_lint_errs() > self.err_count_on_creation {
-            // Errors reported since this infcx was made. Lint errors are
-            // excluded to avoid some being swallowed in the presence of
-            // non-lint errors. (It's arguable whether or not this exclusion is
-            // important.)
-            let guar = self.dcx().has_errors().unwrap();
-            self.set_tainted_by_errors(guar);
-            Some(guar)
-        } else {
-            None
-        }
+        self.tainted_by_errors.get()
     }
 
     /// Set the "tainted by errors" flag to true. We call this when we
@@ -1328,8 +1316,7 @@ impl<'tcx> InferCtxt<'tcx> {
                     bug!("`{value:?}` is not fully resolved");
                 }
                 if value.has_infer_regions() {
-                    let guar =
-                        self.tcx.dcx().delayed_bug(format!("`{value:?}` is not fully resolved"));
+                    let guar = self.dcx().delayed_bug(format!("`{value:?}` is not fully resolved"));
                     Ok(self.tcx.fold_regions(value, |re, _| {
                         if re.is_var() { ty::Region::new_error(self.tcx, guar) } else { re }
                     }))

compiler/rustc_infer/src/infer/opaque_types/mod.rs

@@ -156,7 +156,7 @@ impl<'tcx> InferCtxt<'tcx> {
                     if self.can_define_opaque_ty(b_def_id)
                         && self.tcx.is_type_alias_impl_trait(b_def_id)
                     {
-                        self.tcx.dcx().emit_err(OpaqueHiddenTypeDiag {
+                        self.dcx().emit_err(OpaqueHiddenTypeDiag {
                             span,
                             hidden_type: self.tcx.def_span(b_def_id),
                             opaque_type: self.tcx.def_span(def_id),

compiler/rustc_infer/src/traits/error_reporting/mod.rs

@@ -12,15 +12,15 @@ use std::fmt;
 use std::iter;
 
 impl<'tcx> InferCtxt<'tcx> {
-    pub fn report_extra_impl_obligation(
-        &self,
+    pub fn report_extra_impl_obligation<'a>(
+        &'a self,
         error_span: Span,
         impl_item_def_id: LocalDefId,
         trait_item_def_id: DefId,
         requirement: &dyn fmt::Display,
-    ) -> Diag<'tcx> {
+    ) -> Diag<'a> {
         let mut err = struct_span_code_err!(
-            self.tcx.dcx(),
+            self.dcx(),
             error_span,
             E0276,
             "impl has stricter requirements than trait"