fixed diagnostic

Author: Kivooeo

compiler/rustc_mir_build/src/check_tail_calls.rs

@@ -132,7 +132,11 @@ impl<'tcx> TailCallCkVisitor<'_, 'tcx> {
 
         if caller_sig.inputs_and_output != callee_sig.inputs_and_output {
             if caller_sig.inputs() != callee_sig.inputs() {
-                self.report_arguments_mismatch(expr.span, caller_sig, callee_sig);
+                self.report_arguments_mismatch(
+                    expr.span,
+                    self.caller_ty.fn_sig(self.tcx).skip_binder(),
+                    ty.fn_sig(self.tcx).skip_binder(),
+                );
             }
 
             // FIXME(explicit_tail_calls): this currently fails for cases where opaques are used.

tests/ui/explicit-tail-calls/caller-lifetime-presence.rs

@@ -0,0 +1,39 @@
+//! Regression test for: https://github.com/rust-lang/rust/issues/144957
+//!
+//! This test ensures that lifetime information is included in diagnostics.
+//!
+//! Specifically, it checks that the `become` call produces an error with lifetimes shown
+//! in both caller and callee signatures.
+//!
+//! If the test fails:
+//! - Lifetimes may be missing (fix the diagnostic), or
+//! - The message format changed (update the test).
+
+#![feature(explicit_tail_calls)]
+#![allow(incomplete_features)]
+
+fn foo<'a>(_: fn(&'a ())) {
+    become bar(dummy);
+    //~^ ERROR mismatched signatures
+    //~| NOTE `become` requires caller and callee to have matching signatures
+    //~| NOTE caller signature: `fn(fn(&'a ()))`
+    //~| NOTE callee signature: `fn(for<'a> fn(&'a ()))`
+}
+
+fn bar(_: fn(&())) {}
+
+fn dummy(_: &()) {}
+
+fn foo_(_: fn(&())) {
+    become bar1(dummy2);
+    //~^ ERROR mismatched signatures
+    //~| NOTE `become` requires caller and callee to have matching signatures
+    //~| NOTE caller signature: `fn(for<'a> fn(&'a ()))`
+    //~| NOTE callee signature: `fn(fn(&'a ()))`
+}
+
+fn bar1<'a>(_: fn(&'a ())) {}
+
+fn dummy2(_: &()) {}
+
+fn main() {}

tests/ui/explicit-tail-calls/caller-lifetime-presence.stderr

@@ -0,0 +1,22 @@
+error: mismatched signatures
+  --> $DIR/caller-lifetime-presence.rs:16:5
+   |
+LL |     become bar(dummy);
+   |     ^^^^^^^^^^^^^^^^^
+   |
+   = note: `become` requires caller and callee to have matching signatures
+   = note: caller signature: `fn(fn(&'a ()))`
+   = note: callee signature: `fn(for<'a> fn(&'a ()))`
+
+error: mismatched signatures
+  --> $DIR/caller-lifetime-presence.rs:28:5
+   |
+LL |     become bar1(dummy2);
+   |     ^^^^^^^^^^^^^^^^^^^
+   |
+   = note: `become` requires caller and callee to have matching signatures
+   = note: caller signature: `fn(for<'a> fn(&'a ()))`
+   = note: callee signature: `fn(fn(&'a ()))`
+
+error: aborting due to 2 previous errors
+