Split out `infalliable_detructuring_match`

[rust.git] / clippy_lints / src / tabs_in_doc_comments.rs

diff --git a/clippy_lints/src/tabs_in_doc_comments.rs b/clippy_lints/src/tabs_in_doc_comments.rs
index 3f9692540f70c95a6cce3dbd9c92204ddea7884d..15543b6a2627785bd303a948f911b1fb5bbe1cc1 100644 (file)
--- a/clippy_lints/src/tabs_in_doc_comments.rs
+++ b/clippy_lints/src/tabs_in_doc_comments.rs
@@ -7,16 +7,16 @@
 use std::convert::TryFrom;
 
 declare_clippy_lint! {
-    /// **What it does:** Checks doc comments for usage of tab characters.
+    /// ### What it does
+    /// Checks doc comments for usage of tab characters.
     ///
-    /// **Why is this bad?** The rust style-guide promotes spaces instead of tabs for indentation.
+    /// ### Why is this bad?
+    /// The rust style-guide promotes spaces instead of tabs for indentation.
     /// To keep a consistent view on the source, also doc comments should not have tabs.
     /// Also, explaining ascii-diagrams containing tabs can get displayed incorrectly when the
     /// display settings of the author and reader differ.
     ///
-    /// **Known problems:** None.
-    ///
-    /// **Example:**
+    /// ### Example
     /// ```rust
     /// ///
     /// /// Struct to hold two strings:
@@ -51,6 +51,7 @@
     ///    second_string: String,
     ///}
     /// ```
+    #[clippy::version = "1.41.0"]
     pub TABS_IN_DOC_COMMENTS,
     style,
     "using tabs in doc comments is not recommended"
@@ -63,12 +64,13 @@ fn warn_if_tabs_in_doc(cx: &EarlyContext<'_>, attr: &ast::Attribute) {
         if let ast::AttrKind::DocComment(_, comment) = attr.kind {
             let comment = comment.as_str();
 
-            for (lo, hi) in get_chunks_of_tabs(&comment) {
+            for (lo, hi) in get_chunks_of_tabs(comment) {
                 // +3 skips the opening delimiter
                 let new_span = Span::new(
                     attr.span.lo() + BytePos(3 + lo),
                     attr.span.lo() + BytePos(3 + hi),
                     attr.span.ctxt(),
+                    attr.span.parent(),
                 );
                 span_lint_and_sugg(
                     cx,
@@ -86,7 +88,7 @@ fn warn_if_tabs_in_doc(cx: &EarlyContext<'_>, attr: &ast::Attribute) {
 
 impl EarlyLintPass for TabsInDocComments {
     fn check_attribute(&mut self, cx: &EarlyContext<'_>, attribute: &ast::Attribute) {
-        Self::warn_if_tabs_in_doc(cx, &attribute);
+        Self::warn_if_tabs_in_doc(cx, attribute);
     }
 }
 
@@ -104,9 +106,12 @@ fn get_chunks_of_tabs(the_str: &str) -> Vec<(u32, u32)> {
     // tracker to decide if the last group of tabs is not closed by a non-tab character
     let mut is_active = false;
 
+    // Note that we specifically need the char _byte_ indices here, not the positional indexes
+    // within the char array to deal with multi-byte characters properly. `char_indices` does
+    // exactly that. It provides an iterator over tuples of the form `(byte position, char)`.
     let char_indices: Vec<_> = the_str.char_indices().collect();
 
-    if char_indices.len() == 1 && char_indices.first().unwrap().1 == '\t' {
+    if let [(_, '\t')] = char_indices.as_slice() {
         return vec![(0, 1)];
     }
 
@@ -121,12 +126,12 @@ fn get_chunks_of_tabs(the_str: &str) -> Vec<(u32, u32)> {
                 // as ['\t', '\t'] is excluded, this has to be a start of a tab group,
                 // set indices accordingly
                 is_active = true;
-                current_start = *index_b as u32;
+                current_start = u32::try_from(*index_b).unwrap();
             },
             [(_, '\t'), (index_b, _)] => {
                 // this now has to be an end of the group, hence we have to push a new tuple
                 is_active = false;
-                spans.push((current_start, *index_b as u32));
+                spans.push((current_start, u32::try_from(*index_b).unwrap()));
             },
             _ => {},
         }
@@ -149,7 +154,7 @@ mod tests_for_get_chunks_of_tabs {
 
     #[test]
     fn test_unicode_han_string() {
-        let res = get_chunks_of_tabs(" 位\t");
+        let res = get_chunks_of_tabs(" \u{4f4d}\t");
 
         assert_eq!(res, vec![(4, 5)]);
     }