Ensure that symbols list stays sorted

Author: samueltardieu

clippy_dev/src/fmt.rs

@@ -225,6 +225,31 @@ fn fmt_conf(check: bool) -> Result<(), Error> {
     Ok(())
 }
 
+/// Format the symbols list
+fn fmt_syms(check: bool) -> Result<(), Error> {
+    let path = "clippy_utils/src/sym.rs";
+    let text = fs::read_to_string(path)?;
+
+    let (pre, conf) = text.split_once("generate! {\n").expect("can't find generate! call");
+    let (conf, post) = conf.split_once("\n}\n").expect("can't find end of generate! call");
+    let mut lines = conf
+        .lines()
+        .map(|line| {
+            let line = line.trim();
+            line.strip_suffix(',').unwrap_or(line).trim_end()
+        })
+        .collect::<Vec<_>>();
+    lines.sort_by_cached_key(|a| a.to_uppercase());
+    let new_text = format!("{pre}generate! {{\n    {},\n}}\n{post}", lines.join(",\n    "),);
+    if text != new_text {
+        if check {
+            return Err(Error::CheckFailed);
+        }
+        fs::write(path, new_text.as_bytes())?;
+    }
+    Ok(())
+}
+
 fn run_rustfmt(clippy: &ClippyInfo, update_mode: UpdateMode) {
     let mut rustfmt_path = String::from_utf8(run_with_output(
         "rustup which rustfmt",
@@ -337,7 +362,7 @@ pub fn run(clippy: &ClippyInfo, update_mode: UpdateMode) {
     }
     run_rustfmt(clippy, update_mode);
 
-    if let Err(e) = fmt_conf(update_mode.is_check()) {
+    if let Err(e) = fmt_conf(update_mode.is_check()).and_then(|()| fmt_syms(update_mode.is_check())) {
         e.display();
         process::exit(1);
     }

clippy_utils/src/sym.rs

@@ -31,6 +31,8 @@ macro_rules! generate {
 
 // List of extra symbols to be included in Clippy (for example, as `sym::ambiguous_glob_reexports`).
 // An alternative content can be specified using a colon after the symbol name.
+//
+// `cargo dev fmt` ensures that the content of the `generate!()` macro call stays sorted.
 generate! {
     abs,
     align_of,