Add "better" edition handling on lint-docs tool

compiler/rustc_lint/src/async_fn_in_trait.rs

@@ -11,7 +11,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust
+    /// ```rust,edition2018
     /// pub trait Trait {
     ///     async fn method(&self);
     /// }
@@ -32,7 +32,7 @@ declare_lint! {
     ///
     /// For example, this code is invalid:
     ///
-    /// ```rust,compile_fail
+    /// ```rust,edition2018,compile_fail
     /// pub trait Trait {
     ///     async fn method(&self) {}
     /// }
@@ -49,7 +49,7 @@ declare_lint! {
     ///
     /// For example, instead of:
     ///
-    /// ```rust
+    /// ```rust,edition2018
     /// pub trait Trait {
     ///     async fn method(&self) {}
     /// }

compiler/rustc_lint/src/builtin.rs

@@ -1290,7 +1290,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust
+    /// ```rust,edition2018
     /// #[track_caller]
     /// async fn foo() {}
     /// ```

compiler/rustc_lint/src/deref_into_dyn_supertrait.rs

@@ -19,7 +19,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust,compile_fail
+    /// ```rust,edition2018,compile_fail
     /// #![deny(deref_into_dyn_supertrait)]
     /// #![allow(dead_code)]
     ///

compiler/rustc_lint/src/types.rs

@@ -1899,7 +1899,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust,compile_fail
+    /// ```rust,edition2018,compile_fail
     /// # use core::sync::atomic::{AtomicU8, Ordering};
     /// let atom = AtomicU8::new(0);
     /// let value = atom.load(Ordering::Release);

compiler/rustc_lint_defs/src/builtin.rs

@@ -428,7 +428,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust
+    /// ```rust,edition2018
     /// #![feature(must_not_suspend)]
     /// #![warn(must_not_suspend)]
     ///
@@ -1195,7 +1195,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust,compile_fail
+    /// ```rust,edition2018,compile_fail
     /// extern crate core;
     /// pub use core as reexported_core;
     /// ```
@@ -4514,7 +4514,7 @@ declare_lint! {
     ///
     /// ### Example
     ///
-    /// ```rust,compile_fail
+    /// ```rust,edition2018,compile_fail
     /// #![deny(ambiguous_glob_imports)]
     /// pub fn foo() -> u32 {
     ///     use sub::*;

src/tools/lint-docs/src/lib.rs

@@ -441,10 +441,14 @@ impl<'a> LintExtractor<'a> {
         fs::write(&tempfile, source)
             .map_err(|e| format!("failed to write {}: {}", tempfile.display(), e))?;
         let mut cmd = Command::new(self.rustc_path);
-        if options.contains(&"edition2015") {
-            cmd.arg("--edition=2015");
-        } else {
+        if options.contains(&"edition2024") {
+            cmd.arg("--edition=2024");
+        } else if options.contains(&"edition2021") {
+            cmd.arg("--edition=2021");
+        } else if options.contains(&"edition2018") {
             cmd.arg("--edition=2018");
+        } else {
+            cmd.arg("--edition=2015");
         }
         cmd.arg("--error-format=json");
         cmd.arg("--target").arg(self.rustc_target);