Rollup merge of #61824 - rust-lang:single_derive, r=eddyb

in which we decline to lint single-use lifetimes in `derive`d impls

Resolves #53738.

r? @eddyb

1 files changed, 11 insertions, 0 deletions

diff --git a/src/librustc/middle/resolve_lifetime.rs b/src/librustc/middle/resolve_lifetime.rs
index 8bc3158bd3c..48d2a477a9a 100644
--- a/src/librustc/middle/resolve_lifetime.rs
+++ b/src/librustc/middle/resolve_lifetime.rs
@@ -1586,6 +1586,17 @@ impl<'a, 'tcx> LifetimeContext<'a, 'tcx> {
                             continue;
                         }
 
+                        if let Some(parent_def_id) = self.tcx.parent(def_id) {
+                            if let Some(parent_hir_id) = self.tcx.hir()
+                                .as_local_hir_id(parent_def_id) {
+                                    // lifetimes in `derive` expansions don't count (Issue #53738)
+                                    if self.tcx.hir().attrs_by_hir_id(parent_hir_id).iter()
+                                        .any(|attr| attr.check_name(sym::automatically_derived)) {
+                                            continue;
+                                        }
+                                }
+                        }
+
                         let mut err = self.tcx.struct_span_lint_hir(
                             lint::builtin::SINGLE_USE_LIFETIMES,
                             id,