Auto merge of #107853 - Dylan-DPC:rollup-macf1qo, r=Dylan-DPC

Rollup of 6 pull requests

Successful merges:

 - #107648 (unused-lifetimes: don't warn about lifetimes originating from expanded code)
 - #107655 (rustdoc: use the same URL escape rules for fragments as for examples)
 - #107659 (test: snapshot for derive suggestion in diff files)
 - #107786 (Implement some tweaks in the new solver)
 - #107803 (Do not bring trait alias supertraits into scope)
 - #107815 (Disqualify `auto trait` built-in impl in new solver if explicit `impl` exists)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

1 files changed, 16 insertions, 12 deletions

diff --git a/compiler/rustc_resolve/src/late/diagnostics.rs b/compiler/rustc_resolve/src/late/diagnostics.rs
index cee0a7f3c20..a9dbb3ca131 100644
--- a/compiler/rustc_resolve/src/late/diagnostics.rs
+++ b/compiler/rustc_resolve/src/late/diagnostics.rs
@@ -2244,19 +2244,23 @@ impl<'a: 'ast, 'ast> LateResolutionVisitor<'a, '_, 'ast> {
                 }
                 None => {
                     debug!(?param.ident, ?param.ident.span);
-
                     let deletion_span = deletion_span();
-                    self.r.lint_buffer.buffer_lint_with_diagnostic(
-                        lint::builtin::UNUSED_LIFETIMES,
-                        param.id,
-                        param.ident.span,
-                        &format!("lifetime parameter `{}` never used", param.ident),
-                        lint::BuiltinLintDiagnostics::SingleUseLifetime {
-                            param_span: param.ident.span,
-                            use_span: None,
-                            deletion_span,
-                        },
-                    );
+                    // the give lifetime originates from expanded code so we won't be able to remove it #104432
+                    let lifetime_only_in_expanded_code =
+                        deletion_span.map(|sp| sp.in_derive_expansion()).unwrap_or(true);
+                    if !lifetime_only_in_expanded_code {
+                        self.r.lint_buffer.buffer_lint_with_diagnostic(
+                            lint::builtin::UNUSED_LIFETIMES,
+                            param.id,
+                            param.ident.span,
+                            &format!("lifetime parameter `{}` never used", param.ident),
+                            lint::BuiltinLintDiagnostics::SingleUseLifetime {
+                                param_span: param.ident.span,
+                                use_span: None,
+                                deletion_span,
+                            },
+                        );
+                    }
                 }
             }
         }