Rollup merge of #141781 - matthewjasper:unused-unsafe-lifetimes, r=compiler-errors

Fix spans for unsafe binders

closes rust-lang/rust#141758

r? ``@compiler-errors``

compiler/rustc_resolve/src/late.rs

@@ -934,8 +934,7 @@ impl<'ra: 'ast, 'ast, 'tcx> Visitor<'ast> for LateResolutionVisitor<'_, 'ast, 'r
                 )
             }
             TyKind::UnsafeBinder(unsafe_binder) => {
-                // FIXME(unsafe_binder): Better span
+                let span = ty.span.shrink_to_lo().to(unsafe_binder.inner_ty.span.shrink_to_lo());
-                let span = ty.span;
                 self.with_generic_param_rib(
                     &unsafe_binder.generic_params,
                     RibKind::Normal,

tests/ui/unsafe-binders/unused-lifetimes-2.fixed

@@ -0,0 +1,20 @@
+// regression test for #141758
+//@ run-rustfix
+//@ check-pass
+
+#![warn(unused_lifetimes)]
+#![allow(incomplete_features, unused_imports, dead_code)]
+#![feature(unsafe_binders)]
+
+use std::unsafe_binder::unwrap_binder;
+
+#[derive(Copy, Clone)]
+pub struct S([usize; 8]);
+
+// Regression test for <https://github.com/rust-lang/rust/issues/141418>.
+pub fn by_value(_x: unsafe<'a> &'a S) -> usize {
+    //~^ WARN lifetime parameter `'b` never used
+    0
+}
+
+fn main() {}

tests/ui/unsafe-binders/unused-lifetimes-2.rs

@@ -0,0 +1,20 @@
+// regression test for #141758
+//@ run-rustfix
+//@ check-pass
+
+#![warn(unused_lifetimes)]
+#![allow(incomplete_features, unused_imports, dead_code)]
+#![feature(unsafe_binders)]
+
+use std::unsafe_binder::unwrap_binder;
+
+#[derive(Copy, Clone)]
+pub struct S([usize; 8]);
+
+// Regression test for <https://github.com/rust-lang/rust/issues/141418>.
+pub fn by_value(_x: unsafe<'a, 'b> &'a S) -> usize {
+    //~^ WARN lifetime parameter `'b` never used
+    0
+}
+
+fn main() {}

tests/ui/unsafe-binders/unused-lifetimes-2.stderr

@@ -0,0 +1,16 @@
+warning: lifetime parameter `'b` never used
+  --> $DIR/unused-lifetimes-2.rs:15:32
+   |
+LL | pub fn by_value(_x: unsafe<'a, 'b> &'a S) -> usize {
+   |                              --^^
+   |                              |
+   |                              help: elide the unused lifetime
+   |
+note: the lint level is defined here
+  --> $DIR/unused-lifetimes-2.rs:5:9
+   |
+LL | #![warn(unused_lifetimes)]
+   |         ^^^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+

tests/ui/unsafe-binders/unused-lifetimes.fixed

@@ -0,0 +1,20 @@
+// regression test for #141758
+//@ run-rustfix
+//@ check-pass
+
+#![warn(unused_lifetimes)]
+#![allow(incomplete_features, unused_imports, dead_code)]
+#![feature(unsafe_binders)]
+
+use std::unsafe_binder::unwrap_binder;
+
+#[derive(Copy, Clone)]
+pub struct S([usize; 8]);
+
+// Regression test for <https://github.com/rust-lang/rust/issues/141418>.
+pub fn by_value(_x: S) -> usize {
+    //~^ WARN lifetime parameter `'a` never used
+    0
+}
+
+fn main() {}

tests/ui/unsafe-binders/unused-lifetimes.rs

@@ -0,0 +1,20 @@
+// regression test for #141758
+//@ run-rustfix
+//@ check-pass
+
+#![warn(unused_lifetimes)]
+#![allow(incomplete_features, unused_imports, dead_code)]
+#![feature(unsafe_binders)]
+
+use std::unsafe_binder::unwrap_binder;
+
+#[derive(Copy, Clone)]
+pub struct S([usize; 8]);
+
+// Regression test for <https://github.com/rust-lang/rust/issues/141418>.
+pub fn by_value(_x: unsafe<'a> S) -> usize {
+    //~^ WARN lifetime parameter `'a` never used
+    0
+}
+
+fn main() {}

tests/ui/unsafe-binders/unused-lifetimes.stderr

@@ -0,0 +1,14 @@
+warning: lifetime parameter `'a` never used
+  --> $DIR/unused-lifetimes.rs:15:28
+   |
+LL | pub fn by_value(_x: unsafe<'a> S) -> usize {
+   |                     -------^^-- help: elide the unused lifetime
+   |
+note: the lint level is defined here
+  --> $DIR/unused-lifetimes.rs:5:9
+   |
+LL | #![warn(unused_lifetimes)]
+   |         ^^^^^^^^^^^^^^^^
+
+warning: 1 warning emitted
+