Apply `mismatched-lifetime-syntaxes` to trait and extern functions

2 files changed, 105 insertions, 1 deletions

diff --git a/tests/ui/lifetimes/mismatched-lifetime-syntaxes.rs b/tests/ui/lifetimes/mismatched-lifetime-syntaxes.rs
index 6d8487b99c6..b98423afb17 100644
--- a/tests/ui/lifetimes/mismatched-lifetime-syntaxes.rs
+++ b/tests/ui/lifetimes/mismatched-lifetime-syntaxes.rs
@@ -220,6 +220,45 @@ mod diagnostic_output {
     }
 }
 
+/// Trait functions are represented differently in the HIR. Make sure
+/// we visit them.
+mod trait_functions {
+    #[derive(Copy, Clone)]
+    struct ContainsLifetime<'a>(&'a u8);
+
+    trait TheTrait {
+        fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime;
+        //~^ ERROR lifetime flowing from input to output with different syntax
+
+        fn method_implicit_ref_to_implicit_path(&self) -> ContainsLifetime;
+        //~^ ERROR lifetime flowing from input to output with different syntax
+    }
+
+    impl TheTrait for &u8 {
+        fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime {
+            //~^ ERROR lifetime flowing from input to output with different syntax
+            ContainsLifetime(v)
+        }
+
+        fn method_implicit_ref_to_implicit_path(&self) -> ContainsLifetime {
+            //~^ ERROR lifetime flowing from input to output with different syntax
+            ContainsLifetime(self)
+        }
+    }
+}
+
+/// Extern functions are represented differently in the HIR. Make sure
+/// we visit them.
+mod foreign_functions {
+    #[derive(Copy, Clone)]
+    struct ContainsLifetime<'a>(&'a u8);
+
+    extern "Rust" {
+        fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime;
+        //~^ ERROR lifetime flowing from input to output with different syntax
+    }
+}
+
 /// These usages are expected to **not** trigger the lint
 mod acceptable_uses {
     #[derive(Copy, Clone)]
diff --git a/tests/ui/lifetimes/mismatched-lifetime-syntaxes.stderr b/tests/ui/lifetimes/mismatched-lifetime-syntaxes.stderr
index 0ec16a266b6..108b3f14169 100644
--- a/tests/ui/lifetimes/mismatched-lifetime-syntaxes.stderr
+++ b/tests/ui/lifetimes/mismatched-lifetime-syntaxes.stderr
@@ -469,5 +469,70 @@ help: one option is to consistently use `'a`
 LL |     fn multiple_outputs<'a>(v: &'a u8) -> (&'a u8, &'a u8) {
    |                                             ++      ++
 
-error: aborting due to 34 previous errors
+error: lifetime flowing from input to output with different syntax can be confusing
+  --> $DIR/mismatched-lifetime-syntaxes.rs:230:45
+   |
+LL |         fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime;
+   |                                             ^^^     ---------------- the lifetime gets resolved as `'_`
+   |                                             |
+   |                                             this lifetime flows to the output
+   |
+help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
+   |
+LL |         fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime<'_>;
+   |                                                                     ++++
+
+error: lifetime flowing from input to output with different syntax can be confusing
+  --> $DIR/mismatched-lifetime-syntaxes.rs:233:49
+   |
+LL |         fn method_implicit_ref_to_implicit_path(&self) -> ContainsLifetime;
+   |                                                 ^^^^^     ---------------- the lifetime gets resolved as `'_`
+   |                                                 |
+   |                                                 this lifetime flows to the output
+   |
+help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
+   |
+LL |         fn method_implicit_ref_to_implicit_path(&self) -> ContainsLifetime<'_>;
+   |                                                                           ++++
+
+error: lifetime flowing from input to output with different syntax can be confusing
+  --> $DIR/mismatched-lifetime-syntaxes.rs:238:45
+   |
+LL |         fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime {
+   |                                             ^^^     ---------------- the lifetime gets resolved as `'_`
+   |                                             |
+   |                                             this lifetime flows to the output
+   |
+help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
+   |
+LL |         fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime<'_> {
+   |                                                                     ++++
+
+error: lifetime flowing from input to output with different syntax can be confusing
+  --> $DIR/mismatched-lifetime-syntaxes.rs:243:49
+   |
+LL |         fn method_implicit_ref_to_implicit_path(&self) -> ContainsLifetime {
+   |                                                 ^^^^^     ---------------- the lifetime gets resolved as `'_`
+   |                                                 |
+   |                                                 this lifetime flows to the output
+   |
+help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
+   |
+LL |         fn method_implicit_ref_to_implicit_path(&self) -> ContainsLifetime<'_> {
+   |                                                                           ++++
+
+error: lifetime flowing from input to output with different syntax can be confusing
+  --> $DIR/mismatched-lifetime-syntaxes.rs:257:45
+   |
+LL |         fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime;
+   |                                             ^^^     ---------------- the lifetime gets resolved as `'_`
+   |                                             |
+   |                                             this lifetime flows to the output
+   |
+help: one option is to remove the lifetime for references and use the anonymous lifetime for paths
+   |
+LL |         fn implicit_ref_to_implicit_path(v: &u8) -> ContainsLifetime<'_>;
+   |                                                                     ++++
+
+error: aborting due to 39 previous errors