Move report_elision_failure in diagnostics.rs.

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1871,6 +1871,85 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
         err.emit();
     }
 
+    /// Returns whether to add `'static` lifetime to the suggested lifetime list.
+    crate fn report_elision_failure(
+        &mut self,
+        db: &mut DiagnosticBuilder<'_>,
+        params: &[ElisionFailureInfo],
+    ) -> bool {
+        let mut m = String::new();
+        let len = params.len();
+
+        let elided_params: Vec<_> =
+            params.iter().cloned().filter(|info| info.lifetime_count > 0).collect();
+
+        let elided_len = elided_params.len();
+
+        for (i, info) in elided_params.into_iter().enumerate() {
+            let ElisionFailureInfo { parent, index, lifetime_count: n, have_bound_regions, span } =
+                info;
+
+            db.span_label(span, "");
+            let help_name = if let Some(ident) =
+                parent.and_then(|body| self.tcx.hir().body(body).params[index].pat.simple_ident())
+            {
+                format!("`{}`", ident)
+            } else {
+                format!("argument {}", index + 1)
+            };
+
+            m.push_str(
+                &(if n == 1 {
+                    help_name
+                } else {
+                    format!(
+                        "one of {}'s {} {}lifetimes",
+                        help_name,
+                        n,
+                        if have_bound_regions { "free " } else { "" }
+                    )
+                })[..],
+            );
+
+            if elided_len == 2 && i == 0 {
+                m.push_str(" or ");
+            } else if i + 2 == elided_len {
+                m.push_str(", or ");
+            } else if i != elided_len - 1 {
+                m.push_str(", ");
+            }
+        }
+
+        if len == 0 {
+            db.help(
+                "this function's return type contains a borrowed value, \
+                 but there is no value for it to be borrowed from",
+            );
+            true
+        } else if elided_len == 0 {
+            db.help(
+                "this function's return type contains a borrowed value with \
+                 an elided lifetime, but the lifetime cannot be derived from \
+                 the arguments",
+            );
+            true
+        } else if elided_len == 1 {
+            db.help(&format!(
+                "this function's return type contains a borrowed value, \
+                 but the signature does not say which {} it is borrowed from",
+                m
+            ));
+            false
+        } else {
+            db.help(&format!(
+                "this function's return type contains a borrowed value, \
+                 but the signature does not say whether it is borrowed from {}",
+                m
+            ));
+            false
+        }
+    }
+
     // FIXME(const_generics): This patches over an ICE caused by non-'static lifetimes in const
     // generics. We are disallowing this until we can decide on how we want to handle non-'static
     // lifetimes in const generics. See issue #74052 for discussion.

compiler/rustc_resolve/src/late/lifetimes.rs

@@ -357,11 +357,11 @@ enum Elide {
 #[derive(Clone, Debug)]
 crate struct ElisionFailureInfo {
     /// Where we can find the argument pattern.
-    parent: Option<hir::BodyId>,
+    crate parent: Option<hir::BodyId>,
     /// The index of the argument in the original definition.
-    index: usize,
+    crate index: usize,
-    lifetime_count: usize,
+    crate lifetime_count: usize,
-    have_bound_regions: bool,
+    crate have_bound_regions: bool,
     crate span: Span,
 }
 
@@ -3166,84 +3166,6 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
         err.emit();
     }
 
-    fn report_elision_failure(
-        &mut self,
-        db: &mut DiagnosticBuilder<'_>,
-        params: &[ElisionFailureInfo],
-    ) -> bool /* add `'static` lifetime to lifetime list */ {
-        let mut m = String::new();
-        let len = params.len();
-
-        let elided_params: Vec<_> =
-            params.iter().cloned().filter(|info| info.lifetime_count > 0).collect();
-
-        let elided_len = elided_params.len();
-
-        for (i, info) in elided_params.into_iter().enumerate() {
-            let ElisionFailureInfo { parent, index, lifetime_count: n, have_bound_regions, span } =
-                info;
-
-            db.span_label(span, "");
-            let help_name = if let Some(ident) =
-                parent.and_then(|body| self.tcx.hir().body(body).params[index].pat.simple_ident())
-            {
-                format!("`{}`", ident)
-            } else {
-                format!("argument {}", index + 1)
-            };
-
-            m.push_str(
-                &(if n == 1 {
-                    help_name
-                } else {
-                    format!(
-                        "one of {}'s {} {}lifetimes",
-                        help_name,
-                        n,
-                        if have_bound_regions { "free " } else { "" }
-                    )
-                })[..],
-            );
-
-            if elided_len == 2 && i == 0 {
-                m.push_str(" or ");
-            } else if i + 2 == elided_len {
-                m.push_str(", or ");
-            } else if i != elided_len - 1 {
-                m.push_str(", ");
-            }
-        }
-
-        if len == 0 {
-            db.help(
-                "this function's return type contains a borrowed value, \
-                 but there is no value for it to be borrowed from",
-            );
-            true
-        } else if elided_len == 0 {
-            db.help(
-                "this function's return type contains a borrowed value with \
-                 an elided lifetime, but the lifetime cannot be derived from \
-                 the arguments",
-            );
-            true
-        } else if elided_len == 1 {
-            db.help(&format!(
-                "this function's return type contains a borrowed value, \
-                 but the signature does not say which {} it is borrowed from",
-                m
-            ));
-            false
-        } else {
-            db.help(&format!(
-                "this function's return type contains a borrowed value, \
-                 but the signature does not say whether it is borrowed from {}",
-                m
-            ));
-            false
-        }
-    }
-
     fn resolve_object_lifetime_default(&mut self, lifetime_ref: &'tcx hir::Lifetime) {
         debug!("resolve_object_lifetime_default(lifetime_ref={:?})", lifetime_ref);
         let mut late_depth = 0;