Auto merge of #131368 - GuillaumeGomez:rustdoc-dead-code, r=notriddle

[rustdoc] Remove intra-doc links dead code

While working on https://github.com/rust-lang/rust/pull/130278, I wondered what `resolve_display_text` was doing. I removed it and ran all rustdoc tests, and nothing failed. Are some intra-doc links tests missing or is it really dead code? Couldn't figure it out.

r? `@notriddle`

src/librustdoc/html/markdown.rs

@@ -35,8 +35,7 @@ use std::str::{self, CharIndices};
 use std::sync::OnceLock;
 
 use pulldown_cmark::{
-    BrokenLink, BrokenLinkCallback, CodeBlockKind, CowStr, Event, LinkType, OffsetIter, Options,
+    BrokenLink, CodeBlockKind, CowStr, Event, LinkType, Options, Parser, Tag, TagEnd, html,
-    Parser, Tag, TagEnd, html,
 };
 use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_errors::{Diag, DiagMessage};
@@ -1686,7 +1685,6 @@ pub(crate) fn html_text_from_events<'a>(
 pub(crate) struct MarkdownLink {
     pub kind: LinkType,
     pub link: String,
-    pub display_text: Option<String>,
     pub range: MarkdownLinkRange,
 }
 
@@ -1848,23 +1846,9 @@ pub(crate) fn markdown_links<'md, R>(
                     LinkType::Autolink | LinkType::Email => unreachable!(),
                 };
 
-                let display_text = if matches!(
-                    link_type,
-                    LinkType::Inline
-                        | LinkType::ReferenceUnknown
-                        | LinkType::Reference
-                        | LinkType::Shortcut
-                        | LinkType::ShortcutUnknown
-                ) {
-                    collect_link_data(&mut event_iter)
-                } else {
-                    None
-                };
-
                 if let Some(link) = preprocess_link(MarkdownLink {
                     kind: link_type,
                     link: dest_url.into_string(),
-                    display_text,
                     range,
                 }) {
                     links.push(link);
@@ -1877,37 +1861,6 @@ pub(crate) fn markdown_links<'md, R>(
     links
 }
 
-/// Collects additional data of link.
-fn collect_link_data<'input, F: BrokenLinkCallback<'input>>(
-    event_iter: &mut OffsetIter<'input, F>,
-) -> Option<String> {
-    let mut display_text: Option<String> = None;
-    let mut append_text = |text: CowStr<'_>| {
-        if let Some(display_text) = &mut display_text {
-            display_text.push_str(&text);
-        } else {
-            display_text = Some(text.to_string());
-        }
-    };
-
-    while let Some((event, _span)) = event_iter.next() {
-        match event {
-            Event::Text(text) => {
-                append_text(text);
-            }
-            Event::Code(code) => {
-                append_text(code);
-            }
-            Event::End(_) => {
-                break;
-            }
-            _ => {}
-        }
-    }
-
-    display_text
-}
-
 #[derive(Debug)]
 pub(crate) struct RustCodeBlock {
     /// The range in the markdown that the code block occupies. Note that this includes the fences

src/librustdoc/passes/collect_intra_doc_links.rs

@@ -1040,21 +1040,6 @@ impl LinkCollector<'_, '_> {
             false,
         )?;
 
-        if ori_link.display_text.is_some() {
-            self.resolve_display_text(
-                path_str,
-                ResolutionInfo {
-                    item_id,
-                    module_id,
-                    dis: disambiguator,
-                    path_str: ori_link.display_text.clone()?.into_boxed_str(),
-                    extra_fragment: extra_fragment.clone(),
-                },
-                &ori_link,
-                &diag_info,
-            );
-        }
-
         // Check for a primitive which might conflict with a module
         // Report the ambiguity and require that the user specify which one they meant.
         // FIXME: could there ever be a primitive not in the type namespace?
@@ -1398,58 +1383,6 @@ impl LinkCollector<'_, '_> {
             }
         }
     }
-
-    /// Resolve display text if the provided link has separated parts of links.
-    ///
-    /// For example:
-    /// Inline link `[display_text](dest_link)` and reference link `[display_text][reference_link]` has
-    /// separated parts of links.
-    fn resolve_display_text(
-        &mut self,
-        explicit_link: &Box<str>,
-        display_res_info: ResolutionInfo,
-        ori_link: &MarkdownLink,
-        diag_info: &DiagnosticInfo<'_>,
-    ) {
-        // Check if explicit resolution's path is same as resolution of original link's display text path, see
-        // tests/rustdoc-ui/lint/redundant_explicit_links.rs for more cases.
-        //
-        // To avoid disambiguator from panicking, we check if display text path is possible to be disambiguated
-        // into explicit path.
-        if !matches!(
-            ori_link.kind,
-            LinkType::Inline | LinkType::Reference | LinkType::ReferenceUnknown
-        ) {
-            return;
-        }
-
-        // Algorithm to check if display text could possibly be the explicit link:
-        //
-        // Consider 2 links which are display text and explicit link, pick the shorter
-        // one as symbol and longer one as full qualified path, and tries to match symbol
-        // to the full qualified path's last symbol.
-        //
-        // Otherwise, check if 2 links are same, if so, skip the resolve process.
-        //
-        // Notice that this algorithm is passive, might possibly miss actual redundant cases.
-        let explicit_link = explicit_link.to_string();
-        let display_text = ori_link.display_text.as_ref().unwrap();
-
-        if display_text.len() == explicit_link.len() {
-            // Whether they are same or not, skip the resolve process.
-            return;
-        }
-
-        if explicit_link.ends_with(&display_text[..]) || display_text.ends_with(&explicit_link[..])
-        {
-            self.resolve_with_disambiguator_cached(
-                display_res_info,
-                diag_info.clone(), // this struct should really be Copy, but Range is not :(
-                false,
-                true,
-            );
-        }
-    }
 }
 
 /// Get the section of a link between the backticks,