Rollup merge of #133405 - Zalathar:style-file, r=jieyouxu

tidy: Distinguish between two different meanings of "style file"

This file contains code that uses “style file” to mean “CSS file”, and other code that uses “style file” to mean “this file, which implements the style checker”.

That's very confusing, so it's easier to just say *CSS file* or *this file* as appropriate.

No functional change.

src/tools/tidy/src/style.rs

@@ -337,12 +337,16 @@ pub fn check(path: &Path, bad: &mut bool) {
         .case_insensitive(true)
         .build()
         .unwrap();
-    let style_file = Path::new(file!());
+
+    // In some cases, a style check would be triggered by its own implementation
+    // or comments. A simple workaround is to just allowlist this file.
+    let this_file = Path::new(file!());
+
     walk(path, skip, &mut |entry, contents| {
         let file = entry.path();
         let filename = file.file_name().unwrap().to_string_lossy();
 
-        let is_style_file = filename.ends_with(".css");
+        let is_css_file = filename.ends_with(".css");
         let under_rustfmt = filename.ends_with(".rs") &&
             // This list should ideally be sourced from rustfmt.toml but we don't want to add a toml
             // parser to tidy.
@@ -405,13 +409,13 @@ pub fn check(path: &Path, bad: &mut bool) {
         let mut comment_block: Option<(usize, usize)> = None;
         let is_test = file.components().any(|c| c.as_os_str() == "tests")
             || file.file_stem().unwrap() == "tests";
-        let is_style = file.ends_with(style_file) || style_file.ends_with(file);
-        let is_style_test =
-            is_test && file.parent().unwrap().ends_with(style_file.with_extension(""));
+        let is_this_file = file.ends_with(this_file) || this_file.ends_with(file);
+        let is_test_for_this_file =
+            is_test && file.parent().unwrap().ends_with(this_file.with_extension(""));
         // scanning the whole file for multiple needles at once is more efficient than
         // executing lines times needles separate searches.
         let any_problematic_line =
-            !is_style && !is_style_test && problematic_regex.is_match(contents);
+            !is_this_file && !is_test_for_this_file && problematic_regex.is_match(contents);
         for (i, line) in contents.split('\n').enumerate() {
             if line.is_empty() {
                 if i == 0 {
@@ -458,19 +462,19 @@ pub fn check(path: &Path, bad: &mut bool) {
                     "line longer than {max_columns} chars"
                 );
             }
-            if !is_style_file && line.contains('\t') {
+            if !is_css_file && line.contains('\t') {
                 suppressible_tidy_err!(err, skip_tab, "tab character");
             }
             if line.ends_with(' ') || line.ends_with('\t') {
                 suppressible_tidy_err!(err, skip_end_whitespace, "trailing whitespace");
             }
-            if is_style_file && line.starts_with(' ') {
+            if is_css_file && line.starts_with(' ') {
                 err("CSS files use tabs for indent");
             }
             if line.contains('\r') {
                 suppressible_tidy_err!(err, skip_cr, "CR character");
             }
-            if !is_style {
+            if !is_this_file {
                 // Allow using TODO in diagnostic suggestions by marking the
                 // relevant line with `// ignore-tidy-todo`.
                 if trimmed.contains("TODO") && !trimmed.contains("ignore-tidy-todo") {