Port PlaceholderRelationLfNotSatisfied diagnostic

Author: IntQuant

compiler/rustc_error_messages/locales/en-US/infer.ftl

@@ -338,4 +338,10 @@ infer_srs_add_one = consider returning one of these bindings
 
 infer_await_both_futures = consider `await`ing on both `Future`s
 infer_await_future = consider `await`ing on the `Future`
-infer_await_note = calling an async function returns a future
+infer_await_note = calling an async function returns a future
+
+infer_prlf_defined_with_sub = the lifetime `{$sub_symbol}` defined here...
+infer_prlf_defined_without_sub = the lifetime defined here...
+infer_prlf_must_oultive_with_sup = ...must outlive the lifetime `{$sup_symbol}` defined here
+infer_prlf_must_oultive_without_sup = ...must outlive the lifetime defined here
+infer_prlf_known_limitation = this is a known limitation that will be removed in the future (see issue #100013 <https://github.com/rust-lang/rust/issues/100013> for more information)

compiler/rustc_infer/src/errors/mod.rs

@@ -1093,3 +1093,62 @@ pub enum ConsiderAddingAwait {
         spans: Vec<Span>,
     },
 }
+
+#[derive(Diagnostic)]
+pub enum PlaceholderRelationLfNotSatisfied {
+    #[diag(infer_lf_bound_not_satisfied)]
+    HasBoth {
+        #[primary_span]
+        span: Span,
+        #[note(infer_prlf_defined_with_sub)]
+        sub_span: Span,
+        #[note(infer_prlf_must_oultive_with_sup)]
+        sup_span: Span,
+        sub_symbol: Symbol,
+        sup_symbol: Symbol,
+        #[note(infer_prlf_known_limitation)]
+        note: (),
+    },
+    #[diag(infer_lf_bound_not_satisfied)]
+    HasSub {
+        #[primary_span]
+        span: Span,
+        #[note(infer_prlf_defined_with_sub)]
+        sub_span: Span,
+        #[note(infer_prlf_must_oultive_without_sup)]
+        sup_span: Span,
+        sub_symbol: Symbol,
+        #[note(infer_prlf_known_limitation)]
+        note: (),
+    },
+    #[diag(infer_lf_bound_not_satisfied)]
+    HasSup {
+        #[primary_span]
+        span: Span,
+        #[note(infer_prlf_defined_without_sub)]
+        sub_span: Span,
+        #[note(infer_prlf_must_oultive_with_sup)]
+        sup_span: Span,
+        sup_symbol: Symbol,
+        #[note(infer_prlf_known_limitation)]
+        note: (),
+    },
+    #[diag(infer_lf_bound_not_satisfied)]
+    HasNone {
+        #[primary_span]
+        span: Span,
+        #[note(infer_prlf_defined_without_sub)]
+        sub_span: Span,
+        #[note(infer_prlf_must_oultive_without_sup)]
+        sup_span: Span,
+        #[note(infer_prlf_known_limitation)]
+        note: (),
+    },
+    #[diag(infer_lf_bound_not_satisfied)]
+    OnlyPrimarySpan {
+        #[primary_span]
+        span: Span,
+        #[note(infer_prlf_known_limitation)]
+        note: (),
+    },
+}

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/placeholder_relation.rs

@@ -1,5 +1,8 @@
-use crate::infer::{
-    error_reporting::nice_region_error::NiceRegionError, RegionResolutionError, SubregionOrigin,
+use crate::{
+    errors::PlaceholderRelationLfNotSatisfied,
+    infer::{
+        error_reporting::nice_region_error::NiceRegionError, RegionResolutionError, SubregionOrigin,
+    },
 };
 use rustc_data_structures::intern::Interned;
 use rustc_errors::{DiagnosticBuilder, ErrorGuaranteed};
@@ -16,8 +19,7 @@ impl<'tcx> NiceRegionError<'_, 'tcx> {
                 Region(Interned(RePlaceholder(ty::Placeholder { name: sub_name, .. }), _)),
                 Region(Interned(RePlaceholder(ty::Placeholder { name: sup_name, .. }), _)),
             )) => {
-                let msg = "lifetime bound not satisfied";
-                let mut err = self.tcx().sess.struct_span_err(*span, msg);
+                let span = *span;
                 let (sub_span, sub_symbol) = match sub_name {
                     ty::BrNamed(def_id, symbol) => {
                         (Some(self.tcx().def_span(def_id)), Some(symbol))
@@ -32,41 +34,47 @@ impl<'tcx> NiceRegionError<'_, 'tcx> {
                     ty::BrAnon(_, span) => (*span, None),
                     ty::BrEnv => (None, None),
                 };
-                match (sub_span, sup_span, sub_symbol, sup_symbol) {
-                    (Some(sub_span), Some(sup_span), Some(sub_symbol), Some(sup_symbol)) => {
-                        err.span_note(
+                let diag = match (sub_span, sup_span, sub_symbol, sup_symbol) {
+                    (Some(sub_span), Some(sup_span), Some(&sub_symbol), Some(&sup_symbol)) => {
+                        PlaceholderRelationLfNotSatisfied::HasBoth {
+                            span,
                             sub_span,
-                            format!("the lifetime `{sub_symbol}` defined here..."),
-                        );
-                        err.span_note(
                             sup_span,
-                            format!("...must outlive the lifetime `{sup_symbol}` defined here"),
-                        );
+                            sub_symbol,
+                            sup_symbol,
+                            note: (),
+                        }
                     }
-                    (Some(sub_span), Some(sup_span), _, Some(sup_symbol)) => {
-                        err.span_note(sub_span, "the lifetime defined here...");
-                        err.span_note(
+                    (Some(sub_span), Some(sup_span), _, Some(&sup_symbol)) => {
+                        PlaceholderRelationLfNotSatisfied::HasSup {
+                            span,
+                            sub_span,
                             sup_span,
-                            format!("...must outlive the lifetime `{sup_symbol}` defined here"),
-                        );
+                            sup_symbol,
+                            note: (),
+                        }
                     }
-                    (Some(sub_span), Some(sup_span), Some(sub_symbol), _) => {
-                        err.span_note(
+                    (Some(sub_span), Some(sup_span), Some(&sub_symbol), _) => {
+                        PlaceholderRelationLfNotSatisfied::HasSub {
+                            span,
                             sub_span,
-                            format!("the lifetime `{sub_symbol}` defined here..."),
-                        );
-                        err.span_note(sup_span, "...must outlive the lifetime defined here");
+                            sup_span,
+                            sub_symbol,
+                            note: (),
+                        }
                     }
                     (Some(sub_span), Some(sup_span), _, _) => {
-                        err.span_note(sub_span, "the lifetime defined here...");
-                        err.span_note(sup_span, "...must outlive the lifetime defined here");
+                        PlaceholderRelationLfNotSatisfied::HasNone {
+                            span,
+                            sub_span,
+                            sup_span,
+                            note: (),
+                        }
                     }
-                    _ => {}
-                }
-                err.note("this is a known limitation that will be removed in the future (see issue #100013 <https://github.com/rust-lang/rust/issues/100013> for more information)");
-                Some(err)
+                    _ => PlaceholderRelationLfNotSatisfied::OnlyPrimarySpan { span, note: () },
+                };
+                Some(self.tcx().sess.create_err(diag))
             }
-
             _ => None,
         }
     }