rustdoc: Cleanup doc link extraction

compiler/rustc_resolve/src/rustdoc.rs

@@ -1,11 +1,10 @@
-use pulldown_cmark::{BrokenLink, Event, Options, Parser, Tag};
+use pulldown_cmark::{BrokenLink, Event, LinkType, Options, Parser, Tag};
 use rustc_ast as ast;
 use rustc_ast::util::comments::beautify_doc_string;
 use rustc_data_structures::fx::FxHashMap;
 use rustc_span::def_id::DefId;
 use rustc_span::symbol::{kw, Symbol};
 use rustc_span::Span;
-use std::cell::RefCell;
 use std::{cmp, mem};
 
 #[derive(Clone, Copy, PartialEq, Eq, Debug)]
@@ -348,22 +347,37 @@ fn preprocess_link(link: &str) -> String {
     strip_generics_from_path(link).unwrap_or_else(|_| link.to_string())
 }
 
+/// Keep inline and reference links `[]`,
+/// but skip autolinks `<>` which we never consider to be intra-doc links.
+pub fn may_be_doc_link(link_type: LinkType) -> bool {
+    match link_type {
+        LinkType::Inline
+        | LinkType::Reference
+        | LinkType::ReferenceUnknown
+        | LinkType::Collapsed
+        | LinkType::CollapsedUnknown
+        | LinkType::Shortcut
+        | LinkType::ShortcutUnknown => true,
+        LinkType::Autolink | LinkType::Email => false,
+    }
+}
+
 /// Simplified version of `preprocessed_markdown_links` from rustdoc.
 /// Must return at least the same links as it, but may add some more links on top of that.
 pub(crate) fn attrs_to_preprocessed_links(attrs: &[ast::Attribute]) -> Vec<String> {
     let (doc_fragments, _) = attrs_to_doc_fragments(attrs.iter().map(|attr| (attr, None)), true);
     let doc = prepare_to_doc_link_resolution(&doc_fragments).into_values().next().unwrap();
 
-    let links = RefCell::new(Vec::new());
-    let mut callback = |link: BrokenLink<'_>| {
-        links.borrow_mut().push(preprocess_link(&link.reference));
-        None
-    };
-    for event in Parser::new_with_broken_link_callback(&doc, main_body_opts(), Some(&mut callback))
-    {
-        if let Event::Start(Tag::Link(_, dest, _)) = event {
-            links.borrow_mut().push(preprocess_link(&dest));
+    Parser::new_with_broken_link_callback(
+        &doc,
+        main_body_opts(),
+        Some(&mut |link: BrokenLink<'_>| Some((link.reference, "".into()))),
+    )
+    .filter_map(|event| match event {
+        Event::Start(Tag::Link(link_type, dest, _)) if may_be_doc_link(link_type) => {
+            Some(preprocess_link(&dest))
         }
-    }
-    links.into_inner()
+        _ => None,
+    })
+    .collect()
 }

src/librustdoc/html/markdown.rs

@@ -29,12 +29,12 @@ use rustc_data_structures::fx::FxHashMap;
 use rustc_hir::def_id::DefId;
 use rustc_middle::ty::TyCtxt;
 pub(crate) use rustc_resolve::rustdoc::main_body_opts;
+use rustc_resolve::rustdoc::may_be_doc_link;
 use rustc_span::edition::Edition;
 use rustc_span::{Span, Symbol};
 
 use once_cell::sync::Lazy;
 use std::borrow::Cow;
-use std::cell::RefCell;
 use std::collections::VecDeque;
 use std::default::Default;
 use std::fmt::Write;
@@ -1226,14 +1226,12 @@ pub(crate) struct MarkdownLink {
 
 pub(crate) fn markdown_links<R>(
     md: &str,
-    filter_map: impl Fn(MarkdownLink) -> Option<R>,
+    preprocess_link: impl Fn(MarkdownLink) -> Option<R>,
 ) -> Vec<R> {
     if md.is_empty() {
         return vec![];
     }
 
-    let links = RefCell::new(vec![]);
-
     // FIXME: remove this function once pulldown_cmark can provide spans for link definitions.
     let locate = |s: &str, fallback: Range<usize>| unsafe {
         let s_start = s.as_ptr();
@@ -1265,46 +1263,23 @@ pub(crate) fn markdown_links<R>(
         }
     };
 
-    let mut push = |link: BrokenLink<'_>| {
-        let span = span_for_link(&link.reference, link.span);
-        filter_map(MarkdownLink {
-            kind: LinkType::ShortcutUnknown,
-            link: link.reference.to_string(),
-            range: span,
-        })
-        .map(|link| links.borrow_mut().push(link));
-        None
-    };
-    let p = Parser::new_with_broken_link_callback(md, main_body_opts(), Some(&mut push))
-        .into_offset_iter();
-
-    // There's no need to thread an IdMap through to here because
-    // the IDs generated aren't going to be emitted anywhere.
-    let mut ids = IdMap::new();
-    let iter = Footnotes::new(HeadingLinks::new(p, None, &mut ids, HeadingOffset::H1));
-
-    for ev in iter {
-        if let Event::Start(Tag::Link(
-            // `<>` links cannot be intra-doc links so we skip them.
-            kind @ (LinkType::Inline
-            | LinkType::Reference
-            | LinkType::ReferenceUnknown
-            | LinkType::Collapsed
-            | LinkType::CollapsedUnknown
-            | LinkType::Shortcut
-            | LinkType::ShortcutUnknown),
-            dest,
-            _,
-        )) = ev.0
-        {
-            debug!("found link: {dest}");
-            let span = span_for_link(&dest, ev.1);
-            filter_map(MarkdownLink { kind, link: dest.into_string(), range: span })
-                .map(|link| links.borrow_mut().push(link));
+    Parser::new_with_broken_link_callback(
+        md,
+        main_body_opts(),
+        Some(&mut |link: BrokenLink<'_>| Some((link.reference, "".into()))),
+    )
+    .into_offset_iter()
+    .filter_map(|(event, span)| match event {
+        Event::Start(Tag::Link(link_type, dest, _)) if may_be_doc_link(link_type) => {
+            preprocess_link(MarkdownLink {
+                kind: link_type,
+                range: span_for_link(&dest, span),
+                link: dest.into_string(),
+            })
         }
-    }
-
-    links.into_inner()
+        _ => None,
+    })
+    .collect()
 }
 
 #[derive(Debug)]

tests/rustdoc-ui/intra-doc/unknown-disambiguator.stderr

@@ -20,22 +20,6 @@ LL | //! Linking to [foo@banana] and [`bar@banana!()`].
    |
    = note: see https://doc.rust-lang.org/$CHANNEL/rustdoc/write-documentation/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators
 
-error: unknown disambiguator `foo`
-  --> $DIR/unknown-disambiguator.rs:10:34
-   |
-LL | //! And with weird backticks: [``foo@hello``] [foo`@`hello].
-   |                                  ^^^
-   |
-   = note: see https://doc.rust-lang.org/$CHANNEL/rustdoc/write-documentation/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators
-
-error: unknown disambiguator `foo`
-  --> $DIR/unknown-disambiguator.rs:10:48
-   |
-LL | //! And with weird backticks: [``foo@hello``] [foo`@`hello].
-   |                                                ^^^
-   |
-   = note: see https://doc.rust-lang.org/$CHANNEL/rustdoc/write-documentation/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators
-
 error: unknown disambiguator ``
   --> $DIR/unknown-disambiguator.rs:7:31
    |
@@ -52,5 +36,21 @@ LL | //! And to [no disambiguator](@nectarine) and [another](@apricot!()).
    |
    = note: see https://doc.rust-lang.org/$CHANNEL/rustdoc/write-documentation/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators
 
+error: unknown disambiguator `foo`
+  --> $DIR/unknown-disambiguator.rs:10:34
+   |
+LL | //! And with weird backticks: [``foo@hello``] [foo`@`hello].
+   |                                  ^^^
+   |
+   = note: see https://doc.rust-lang.org/$CHANNEL/rustdoc/write-documentation/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators
+
+error: unknown disambiguator `foo`
+  --> $DIR/unknown-disambiguator.rs:10:48
+   |
+LL | //! And with weird backticks: [``foo@hello``] [foo`@`hello].
+   |                                                ^^^
+   |
+   = note: see https://doc.rust-lang.org/$CHANNEL/rustdoc/write-documentation/linking-to-items-by-name.html#namespaces-and-disambiguators for more info about disambiguators
+
 error: aborting due to 6 previous errors