Rollup merge of #146413 - GuillaumeGomez:rustdoc-bare-urls, r=lolbinarycat

Improve suggestion in case a bare URL is surrounded by brackets

Fixes https://github.com/rust-lang/rust/issues/146162.

With this change, output looks like this:

```
  |
1 | //! [https://github.com]
  |     ^^^^^^^^^^^^^^^^^^^^ help: use an automatic link instead: `<https://github.com>`
  |
  = note: bare URLs are not automatically turned into clickable links
  = note: `#[warn(rustdoc::bare_urls)]` on by default
```

cc ```@fmease```
r? ```@lolbinarycat```

1 files changed, 39 insertions, 18 deletions

diff --git a/src/librustdoc/passes/lint/bare_urls.rs b/src/librustdoc/passes/lint/bare_urls.rs
index f70bdf4e4fe..06256d61151 100644
--- a/src/librustdoc/passes/lint/bare_urls.rs
+++ b/src/librustdoc/passes/lint/bare_urls.rs
@@ -17,7 +17,10 @@ use crate::core::DocContext;
 use crate::html::markdown::main_body_opts;
 
 pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item, hir_id: HirId, dox: &str) {
-    let report_diag = |cx: &DocContext<'_>, msg: &'static str, range: Range<usize>| {
+    let report_diag = |cx: &DocContext<'_>,
+                       msg: &'static str,
+                       range: Range<usize>,
+                       without_brackets: Option<&str>| {
         let maybe_sp = source_span_for_markdown_range(cx.tcx, dox, &range, &item.attrs.doc_strings)
             .map(|(sp, _)| sp);
         let sp = maybe_sp.unwrap_or_else(|| item.attr_span(cx.tcx));
@@ -27,14 +30,22 @@ pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item, hir_id: HirId, dox: &
             // The fallback of using the attribute span is suitable for
             // highlighting where the error is, but not for placing the < and >
             if let Some(sp) = maybe_sp {
-                lint.multipart_suggestion(
-                    "use an automatic link instead",
-                    vec![
-                        (sp.shrink_to_lo(), "<".to_string()),
-                        (sp.shrink_to_hi(), ">".to_string()),
-                    ],
-                    Applicability::MachineApplicable,
-                );
+                if let Some(without_brackets) = without_brackets {
+                    lint.multipart_suggestion(
+                        "use an automatic link instead",
+                        vec![(sp, format!("<{without_brackets}>"))],
+                        Applicability::MachineApplicable,
+                    );
+                } else {
+                    lint.multipart_suggestion(
+                        "use an automatic link instead",
+                        vec![
+                            (sp.shrink_to_lo(), "<".to_string()),
+                            (sp.shrink_to_hi(), ">".to_string()),
+                        ],
+                        Applicability::MachineApplicable,
+                    );
+                }
             }
         });
     };
@@ -43,7 +54,7 @@ pub(super) fn visit_item(cx: &DocContext<'_>, item: &Item, hir_id: HirId, dox: &
 
     while let Some((event, range)) = p.next() {
         match event {
-            Event::Text(s) => find_raw_urls(cx, &s, range, &report_diag),
+            Event::Text(s) => find_raw_urls(cx, dox, &s, range, &report_diag),
             // We don't want to check the text inside code blocks or links.
             Event::Start(tag @ (Tag::CodeBlock(_) | Tag::Link { .. })) => {
                 for (event, _) in p.by_ref() {
@@ -67,25 +78,35 @@ static URL_REGEX: LazyLock<Regex> = LazyLock::new(|| {
         r"https?://",                          // url scheme
         r"([-a-zA-Z0-9@:%._\+~#=]{2,256}\.)+", // one or more subdomains
         r"[a-zA-Z]{2,63}",                     // root domain
-        r"\b([-a-zA-Z0-9@:%_\+.~#?&/=]*)"      // optional query or url fragments
+        r"\b([-a-zA-Z0-9@:%_\+.~#?&/=]*)",     // optional query or url fragments
     ))
     .expect("failed to build regex")
 });
 
 fn find_raw_urls(
     cx: &DocContext<'_>,
+    dox: &str,
     text: &str,
     range: Range<usize>,
-    f: &impl Fn(&DocContext<'_>, &'static str, Range<usize>),
+    f: &impl Fn(&DocContext<'_>, &'static str, Range<usize>, Option<&str>),
 ) {
     trace!("looking for raw urls in {text}");
     // For now, we only check "full" URLs (meaning, starting with "http://" or "https://").
     for match_ in URL_REGEX.find_iter(text) {
-        let url_range = match_.range();
-        f(
-            cx,
-            "this URL is not a hyperlink",
-            Range { start: range.start + url_range.start, end: range.start + url_range.end },
-        );
+        let mut url_range = match_.range();
+        url_range.start += range.start;
+        url_range.end += range.start;
+        let mut without_brackets = None;
+        // If the link is contained inside `[]`, then we need to replace the brackets and
+        // not just add `<>`.
+        if dox[..url_range.start].ends_with('[')
+            && url_range.end <= dox.len()
+            && dox[url_range.end..].starts_with(']')
+        {
+            url_range.start -= 1;
+            url_range.end += 1;
+            without_brackets = Some(match_.as_str());
+        }
+        f(cx, "this URL is not a hyperlink", url_range, without_brackets);
     }
 }