Address rust-lang/rust#111748

Author: smoelius

driver/src/lib.rs

@@ -1,4 +1,5 @@
 #![feature(rustc_private)]
+#![feature(string_leak)]
 #![deny(clippy::expect_used)]
 #![deny(clippy::unwrap_used)]
 #![deny(clippy::panic)]
@@ -119,14 +120,17 @@ impl Callbacks {
                 let lib = result.unwrap_or_else(|err| {
                     // smoelius: rust-lang/rust#111633 changed the type of `early_error`'s `msg`
                     // argument from `&str` to `impl Into<DiagnosticMessage>`.
+                    // smoelius: And rust-lang/rust#111748 made it that `msg` is borrowed for
+                    // `'static`. Since the program is about to exit, it's probably fine to leak the
+                    // string.
                     rustc_session::early_error(
                         rustc_session::config::ErrorOutputType::default(),
                         format!(
                             "could not load library `{}`: {}",
                             path.to_string_lossy(),
                             err
                         )
-                        .as_str(),
+                        .leak(),
                     );
                 });
 

utils/linting/src/lib.rs

@@ -168,6 +168,7 @@
 //! [examples]: ../../examples
 
 #![feature(rustc_private)]
+#![feature(string_leak)]
 #![warn(unused_extern_crates)]
 
 #[allow(unused_extern_crates)]
@@ -457,7 +458,7 @@ pub fn init_config(sess: &rustc_session::Session) {
     try_init_config(sess).unwrap_or_else(|err| {
         rustc_session::early_error(
             rustc_session::config::ErrorOutputType::default(),
-            format!("could not read configuration file: {err}").as_str(),
+            format!("could not read configuration file: {err}").leak(),
         );
     });
 }