rustdoc: improve refdef handling in the unresolved link lint

compiler/rustc_resolve/src/rustdoc.rs

@@ -7,7 +7,7 @@ use pulldown_cmark::{
 use rustc_ast as ast;
 use rustc_ast::attr::AttributeExt;
 use rustc_ast::util::comments::beautify_doc_string;
-use rustc_data_structures::fx::FxIndexMap;
+use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
 use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::DefId;
 use rustc_span::{DUMMY_SP, InnerSpan, Span, Symbol, kw, sym};
@@ -422,9 +422,11 @@ fn parse_links<'md>(doc: &'md str) -> Vec<Box<str>> {
     );
     let mut links = Vec::new();
 
+    let mut refids = FxHashSet::default();
+
     while let Some(event) = event_iter.next() {
         match event {
-            Event::Start(Tag::Link { link_type, dest_url, title: _, id: _ })
+            Event::Start(Tag::Link { link_type, dest_url, title: _, id })
                 if may_be_doc_link(link_type) =>
             {
                 if matches!(
@@ -439,13 +441,25 @@ fn parse_links<'md>(doc: &'md str) -> Vec<Box<str>> {
                         links.push(display_text);
                     }
                 }
+                if matches!(
+                    link_type,
+                    LinkType::Reference | LinkType::Shortcut | LinkType::Collapsed
+                ) {
+                    refids.insert(id);
+                }
 
                 links.push(preprocess_link(&dest_url));
             }
             _ => {}
         }
     }
 
+    for (label, refdef) in event_iter.reference_definitions().iter() {
+        if !refids.contains(label) {
+            links.push(preprocess_link(&refdef.dest));
+        }
+    }
+
     links
 }
 

library/alloc/src/boxed.rs

@@ -1053,7 +1053,6 @@ impl<T: ?Sized> Box<T> {
     /// ```
     ///
     /// [memory layout]: self#memory-layout
-    /// [`Layout`]: crate::Layout
     #[stable(feature = "box_raw", since = "1.4.0")]
     #[inline]
     #[must_use = "call `drop(Box::from_raw(ptr))` if you intend to drop the `Box`"]
@@ -1108,7 +1107,6 @@ impl<T: ?Sized> Box<T> {
     /// ```
     ///
     /// [memory layout]: self#memory-layout
-    /// [`Layout`]: crate::Layout
     #[unstable(feature = "box_vec_non_null", reason = "new API", issue = "130364")]
     #[inline]
     #[must_use = "call `drop(Box::from_non_null(ptr))` if you intend to drop the `Box`"]
@@ -1165,7 +1163,6 @@ impl<T: ?Sized, A: Allocator> Box<T, A> {
     /// ```
     ///
     /// [memory layout]: self#memory-layout
-    /// [`Layout`]: crate::Layout
     #[unstable(feature = "allocator_api", issue = "32838")]
     #[rustc_const_unstable(feature = "const_box", issue = "92521")]
     #[inline]
@@ -1219,7 +1216,6 @@ impl<T: ?Sized, A: Allocator> Box<T, A> {
     /// ```
     ///
     /// [memory layout]: self#memory-layout
-    /// [`Layout`]: crate::Layout
     #[unstable(feature = "allocator_api", issue = "32838")]
     // #[unstable(feature = "box_vec_non_null", reason = "new API", issue = "130364")]
     #[rustc_const_unstable(feature = "const_box", issue = "92521")]

library/core/src/task/wake.rs

@@ -40,17 +40,14 @@ impl RawWaker {
     /// of the `vtable` as the first parameter.
     ///
     /// It is important to consider that the `data` pointer must point to a
-    /// thread safe type such as an `[Arc]<T: Send + Sync>`
+    /// thread safe type such as an `Arc<T: Send + Sync>`
     /// when used to construct a [`Waker`]. This restriction is lifted when
     /// constructing a [`LocalWaker`], which allows using types that do not implement
-    /// <code>[Send] + [Sync]</code> like `[Rc]<T>`.
+    /// <code>[Send] + [Sync]</code> like `Rc<T>`.
     ///
     /// The `vtable` customizes the behavior of a `Waker` which gets created
     /// from a `RawWaker`. For each operation on the `Waker`, the associated
     /// function in the `vtable` of the underlying `RawWaker` will be called.
-    ///
-    /// [`Arc`]: std::sync::Arc
-    /// [`Rc`]: std::rc::Rc
     #[inline]
     #[rustc_promotable]
     #[stable(feature = "futures_api", since = "1.36.0")]

src/librustdoc/html/markdown.rs

@@ -38,7 +38,7 @@ use std::sync::{Arc, Weak};
 use pulldown_cmark::{
     BrokenLink, CodeBlockKind, CowStr, Event, LinkType, Options, Parser, Tag, TagEnd, html,
 };
-use rustc_data_structures::fx::FxHashMap;
+use rustc_data_structures::fx::{FxHashMap, FxIndexMap};
 use rustc_errors::{Diag, DiagMessage};
 use rustc_hir::def_id::LocalDefId;
 use rustc_middle::ty::TyCtxt;
@@ -1763,6 +1763,46 @@ pub(crate) fn markdown_links<'md, R>(
         }
     };
 
+    let span_for_refdef = |link: &CowStr<'_>, span: Range<usize>| {
+        // We want to underline the link's definition, but `span` will point at the entire refdef.
+        // Skip the label, then try to find the entire URL.
+        let mut square_brace_count = 0;
+        let mut iter = md.as_bytes()[span.start..span.end].iter().copied().enumerate();
+        for (_i, c) in &mut iter {
+            match c {
+                b':' if square_brace_count == 0 => break,
+                b'[' => square_brace_count += 1,
+                b']' => square_brace_count -= 1,
+                _ => {}
+            }
+        }
+        while let Some((i, c)) = iter.next() {
+            if c == b'<' {
+                while let Some((j, c)) = iter.next() {
+                    match c {
+                        b'\\' => {
+                            let _ = iter.next();
+                        }
+                        b'>' => {
+                            return MarkdownLinkRange::Destination(
+                                i + 1 + span.start..j + span.start,
+                            );
+                        }
+                        _ => {}
+                    }
+                }
+            } else if !c.is_ascii_whitespace() {
+                while let Some((j, c)) = iter.next() {
+                    if c.is_ascii_whitespace() {
+                        return MarkdownLinkRange::Destination(i + span.start..j + span.start);
+                    }
+                }
+                return MarkdownLinkRange::Destination(i + span.start..span.end);
+            }
+        }
+        span_for_link(link, span)
+    };
+
     let span_for_offset_backward = |span: Range<usize>, open: u8, close: u8| {
         let mut open_brace = !0;
         let mut close_brace = !0;
@@ -1844,9 +1884,16 @@ pub(crate) fn markdown_links<'md, R>(
     .into_offset_iter();
     let mut links = Vec::new();
 
+    let mut refdefs = FxIndexMap::default();
+    for (label, refdef) in event_iter.reference_definitions().iter() {
+        refdefs.insert(label.to_string(), (false, refdef.dest.to_string(), refdef.span.clone()));
+    }
+
     for (event, span) in event_iter {
         match event {
-            Event::Start(Tag::Link { link_type, dest_url, .. }) if may_be_doc_link(link_type) => {
+            Event::Start(Tag::Link { link_type, dest_url, id, .. })
+                if may_be_doc_link(link_type) =>
+            {
                 let range = match link_type {
                     // Link is pulled from the link itself.
                     LinkType::ReferenceUnknown | LinkType::ShortcutUnknown => {
@@ -1856,7 +1903,12 @@ pub(crate) fn markdown_links<'md, R>(
                     LinkType::Inline => span_for_offset_backward(span, b'(', b')'),
                     // Link is pulled from elsewhere in the document.
                     LinkType::Reference | LinkType::Collapsed | LinkType::Shortcut => {
-                        span_for_link(&dest_url, span)
+                        if let Some((is_used, dest_url, span)) = refdefs.get_mut(&id[..]) {
+                            *is_used = true;
+                            span_for_refdef(&CowStr::from(&dest_url[..]), span.clone())
+                        } else {
+                            span_for_link(&dest_url, span)
+                        }
                     }
                     LinkType::Autolink | LinkType::Email => unreachable!(),
                 };
@@ -1873,6 +1925,18 @@ pub(crate) fn markdown_links<'md, R>(
         }
     }
 
+    for (_label, (is_used, dest_url, span)) in refdefs.into_iter() {
+        if !is_used
+            && let Some(link) = preprocess_link(MarkdownLink {
+                kind: LinkType::Reference,
+                range: span_for_refdef(&CowStr::from(&dest_url[..]), span),
+                link: dest_url,
+            })
+        {
+            links.push(link);
+        }
+    }
+
     links
 }
 

tests/rustdoc-ui/intra-doc/weird-syntax.rs

@@ -117,24 +117,49 @@ pub struct WLinkToCloneWithUnmatchedEscapedCloseParenAndDoubleSpace;
 
 // References
 
-/// The [cln][] link here is going to be unresolved, because `Clone()` gets rejected //~ERROR link
-/// in Markdown for not being URL-shaped enough.
-///
-/// [cln]: Clone() //~ERROR link
+/// The [cln][] link here is going to be unresolved, because `Clone()` gets
+//~^ ERROR link
+/// rejected in Markdown for not being URL-shaped enough.
+/// [cln]: Clone()
+//~^ ERROR link
 pub struct LinkToCloneWithParensInReference;
 
-/// The [cln][] link here is going to be unresolved, because `struct@Clone` gets //~ERROR link
-/// rejected in Markdown for not being URL-shaped enough.
+/// The [cln][] link here is going to produce a good inline suggestion
 ///
-/// [cln]: struct@Clone //~ERROR link
+/// [cln]: struct@Clone
+//~^ ERROR link
 pub struct LinkToCloneWithWrongPrefix;
 
-/// The [cln][] link here will produce a plain text suggestion //~ERROR link
+/// The [cln][] link here will produce a good inline suggestion
 ///
 /// [cln]: Clone\(\)
+//~^ ERROR link
 pub struct LinkToCloneWithEscapedParensInReference;
 
-/// The [cln][] link here will produce a plain text suggestion //~ERROR link
+/// The [cln][] link here will produce a good inline suggestion
 ///
 /// [cln]: struct\@Clone
+//~^ ERROR link
 pub struct LinkToCloneWithEscapedAtsInReference;
+
+
+/// This link reference definition isn't used, but since it is still parsed,
+/// it should still produce a warning.
+///
+/// [cln]: struct\@Clone
+//~^ ERROR link
+pub struct UnusedLinkToCloneReferenceDefinition;
+
+/// <https://github.com/rust-lang/rust/issues/133150>
+///
+/// - [`SDL_PROP_WINDOW_CREATE_COCOA_WINDOW_POINTER`]: the
+//~^ ERROR link
+///   `(__unsafe_unretained)` NSWindow associated with the window, if you want
+///   to wrap an existing window.
+/// - [`SDL_PROP_WINDOW_CREATE_COCOA_VIEW_POINTER`]: the `(__unsafe_unretained)`
+///   NSView associated with the window, defaults to `[window contentView]`
+pub fn a() {}
+#[allow(nonstandard_style)]
+pub struct SDL_PROP_WINDOW_CREATE_COCOA_WINDOW_POINTER;
+#[allow(nonstandard_style)]
+pub struct SDL_PROP_WINDOW_CREATE_COCOA_VIEW_POINTER;

tests/rustdoc-ui/intra-doc/weird-syntax.stderr

@@ -230,7 +230,7 @@ LL | /// [w](Clone  \))
 error: unresolved link to `cln`
   --> $DIR/weird-syntax.rs:120:10
    |
-LL | /// The [cln][] link here is going to be unresolved, because `Clone()` gets rejected
+LL | /// The [cln][] link here is going to be unresolved, because `Clone()` gets
    |          ^^^ no item named `cln` in scope
    |
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
@@ -243,37 +243,61 @@ LL | /// [cln]: Clone()
    |
    = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
 
-error: unresolved link to `cln`
-  --> $DIR/weird-syntax.rs:126:10
+error: incompatible link kind for `Clone`
+  --> $DIR/weird-syntax.rs:129:12
    |
-LL | /// The [cln][] link here is going to be unresolved, because `struct@Clone` gets
-   |          ^^^ no item named `cln` in scope
+LL | /// [cln]: struct@Clone
+   |            ^^^^^^^^^^^^ this link resolved to a trait, which is not a struct
    |
-   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
-
-error: unresolved link to `cln`
-  --> $DIR/weird-syntax.rs:129:6
+help: to link to the trait, prefix with `trait@`
    |
-LL | /// [cln]: struct@Clone
-   |      ^^^ no item named `cln` in scope
+LL - /// [cln]: struct@Clone
+LL + /// [cln]: trait@Clone
    |
-   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
 
 error: unresolved link to `Clone`
-  --> $DIR/weird-syntax.rs:132:9
+  --> $DIR/weird-syntax.rs:135:12
+   |
+LL | /// [cln]: Clone\(\)
+   |            ^^^^^^^^^ this link resolves to the trait `Clone`, which is not a function
+   |
+help: to link to the trait, prefix with `trait@`
    |
-LL | /// The [cln][] link here will produce a plain text suggestion
-   |         ^^^^^ this link resolves to the trait `Clone`, which is not a function
+LL - /// [cln]: Clone\(\)
+LL + /// [cln]: trait@Clone
    |
-   = help: to link to the trait, prefix with `trait@`: trait@Clone
 
 error: incompatible link kind for `Clone`
-  --> $DIR/weird-syntax.rs:137:9
+  --> $DIR/weird-syntax.rs:141:12
    |
-LL | /// The [cln][] link here will produce a plain text suggestion
-   |         ^^^^^ this link resolved to a trait, which is not a struct
+LL | /// [cln]: struct\@Clone
+   |            ^^^^^^^^^^^^^ this link resolved to a trait, which is not a struct
    |
-   = help: to link to the trait, prefix with `trait@`: trait@Clone
+help: to link to the trait, prefix with `trait@`
+   |
+LL - /// [cln]: struct\@Clone
+LL + /// [cln]: trait@struct
+   |
+
+error: incompatible link kind for `Clone`
+  --> $DIR/weird-syntax.rs:149:12
+   |
+LL | /// [cln]: struct\@Clone
+   |            ^^^^^^^^^^^^^ this link resolved to a trait, which is not a struct
+   |
+help: to link to the trait, prefix with `trait@`
+   |
+LL - /// [cln]: struct\@Clone
+LL + /// [cln]: trait@struct
+   |
+
+error: unresolved link to `the`
+  --> $DIR/weird-syntax.rs:155:56
+   |
+LL | /// - [`SDL_PROP_WINDOW_CREATE_COCOA_WINDOW_POINTER`]: the
+   |                                                        ^^^ no item named `the` in scope
+   |
+   = help: to escape `[` and `]` characters, add '\' before them like `\[` or `\]`
 
-error: aborting due to 26 previous errors
+error: aborting due to 27 previous errors