From a8f68240d391dd885c13766e6152a79d758c1440 Mon Sep 17 00:00:00 2001
From: dswij <dswijj@gmail.com>
Date: Fri, 24 Jun 2022 18:00:06 +0800
Subject: [PATCH] Add test for `extra_unused_lifetimes` FP on derive

This commit adds test for a `extra_unused_lifetimes` false positive from derive (#9014).

The fix for the FP is introduced in #9037.
---
 tests/ui/auxiliary/proc_macro_derive.rs | 14 ++++++++++++++
 tests/ui/extra_unused_lifetimes.rs      | 12 ++++++++++++
 tests/ui/extra_unused_lifetimes.stderr  | 12 ++++++------
 3 files changed, 32 insertions(+), 6 deletions(-)

diff --git a/tests/ui/auxiliary/proc_macro_derive.rs b/tests/ui/auxiliary/proc_macro_derive.rs
index ed7b17651e675..a89a06308d093 100644
--- a/tests/ui/auxiliary/proc_macro_derive.rs
+++ b/tests/ui/auxiliary/proc_macro_derive.rs
@@ -72,3 +72,17 @@ pub fn mini_macro(_: TokenStream) -> TokenStream {
         }
     )
 }
+
+#[proc_macro_derive(ExtraLifetimeDerive)]
+#[allow(unused)]
+pub fn extra_lifetime(_input: TokenStream) -> TokenStream {
+    quote!(
+        pub struct ExtraLifetime;
+
+        impl<'b> ExtraLifetime {
+            pub fn something<'c>() -> Self {
+                Self
+            }
+        }
+    )
+}
diff --git a/tests/ui/extra_unused_lifetimes.rs b/tests/ui/extra_unused_lifetimes.rs
index f76127a7105fd..d6631e0129000 100644
--- a/tests/ui/extra_unused_lifetimes.rs
+++ b/tests/ui/extra_unused_lifetimes.rs
@@ -1,3 +1,5 @@
+// aux-build:proc_macro_derive.rs
+
 #![allow(
     unused,
     dead_code,
@@ -7,6 +9,9 @@
 )]
 #![warn(clippy::extra_unused_lifetimes)]
 
+#[macro_use]
+extern crate proc_macro_derive;
+
 fn empty() {}
 
 fn used_lt<'a>(x: &'a u8) {}
@@ -114,4 +119,11 @@ mod second_case {
     }
 }
 
+// Should not lint
+#[derive(ExtraLifetimeDerive)]
+struct Human<'a> {
+    pub bones: i32,
+    pub name: &'a str,
+}
+
 fn main() {}
diff --git a/tests/ui/extra_unused_lifetimes.stderr b/tests/ui/extra_unused_lifetimes.stderr
index fcc12d4ce14b9..26ebc3976dfca 100644
--- a/tests/ui/extra_unused_lifetimes.stderr
+++ b/tests/ui/extra_unused_lifetimes.stderr
@@ -1,5 +1,5 @@
 error: this lifetime isn't used in the function definition
-  --> $DIR/extra_unused_lifetimes.rs:14:14
+  --> $DIR/extra_unused_lifetimes.rs:19:14
    |
 LL | fn unused_lt<'a>(x: u8) {}
    |              ^^
@@ -7,31 +7,31 @@ LL | fn unused_lt<'a>(x: u8) {}
    = note: `-D clippy::extra-unused-lifetimes` implied by `-D warnings`
 
 error: this lifetime isn't used in the function definition
-  --> $DIR/extra_unused_lifetimes.rs:41:10
+  --> $DIR/extra_unused_lifetimes.rs:46:10
    |
 LL |     fn x<'a>(&self) {}
    |          ^^
 
 error: this lifetime isn't used in the function definition
-  --> $DIR/extra_unused_lifetimes.rs:67:22
+  --> $DIR/extra_unused_lifetimes.rs:72:22
    |
 LL |         fn unused_lt<'a>(x: u8) {}
    |                      ^^
 
 error: this lifetime isn't used in the impl
-  --> $DIR/extra_unused_lifetimes.rs:78:10
+  --> $DIR/extra_unused_lifetimes.rs:83:10
    |
 LL |     impl<'a> std::ops::AddAssign<&Scalar> for &mut Scalar {
    |          ^^
 
 error: this lifetime isn't used in the impl
-  --> $DIR/extra_unused_lifetimes.rs:84:10
+  --> $DIR/extra_unused_lifetimes.rs:89:10
    |
 LL |     impl<'b> Scalar {
    |          ^^
 
 error: this lifetime isn't used in the function definition
-  --> $DIR/extra_unused_lifetimes.rs:85:26
+  --> $DIR/extra_unused_lifetimes.rs:90:26
    |
 LL |         pub fn something<'c>() -> Self {
    |                          ^^