rustdoc: Add more semantic information to impl ids

Instead of generating `#impl`, `#impl-1`, etc., generate IDs like `#impl-Foo<M>`. Co-authored-by: Noah Lev <camelidcamel@gmail.com>

Author: 2 people

src/librustdoc/html/render/mod.rs

@@ -634,7 +634,6 @@ fn render_impls(
  &[],
  ImplRenderingParameters {
  show_def_docs: true,
- is_on_foreign_type: false,
  show_default_items: true,
  show_non_assoc_items: true,
  toggle_open_by_default,
@@ -1071,7 +1070,6 @@ fn render_assoc_items_inner(
  &[],
  ImplRenderingParameters {
  show_def_docs: true,
- is_on_foreign_type: false,
  show_default_items: true,
  show_non_assoc_items: true,
  toggle_open_by_default: true,
@@ -1287,7 +1285,6 @@ fn notable_traits_decl(decl: &clean::FnDecl, cx: &Context<'_>) -> String {
 #[derive(Clone, Copy, Debug)]
 struct ImplRenderingParameters {
  show_def_docs: bool,
- is_on_foreign_type: bool,
  show_default_items: bool,
  /// Whether or not to show methods.
  show_non_assoc_items: bool,
@@ -1603,7 +1600,6 @@ fn render_impl(
  parent,
  rendering_params.show_def_docs,
  use_absolute,
- rendering_params.is_on_foreign_type,
  aliases,
  );
  if toggled {
@@ -1688,21 +1684,12 @@ pub(crate) fn render_impl_summary(
  containing_item: &clean::Item,
  show_def_docs: bool,
  use_absolute: Option<bool>,
- is_on_foreign_type: bool,
  // This argument is used to reference same type with different paths to avoid duplication
  // in documentation pages for trait with automatic implementations like "Send" and "Sync".
  aliases: &[String],
 ) {
- let id = cx.derive_id(match i.inner_impl().trait_ {
- Some(ref t) => {
- if is_on_foreign_type {
- get_id_for_impl_on_foreign_type(&i.inner_impl().for_, t, cx)
- } else {
- format!("impl-{}", small_url_encode(format!("{:#}", t.print(cx))))
- }
- }
- None => "impl".to_string(),
- });
+ let id =
+ cx.derive_id(get_id_for_impl(&i.inner_impl().for_, i.inner_impl().trait_.as_ref(), cx));
  let aliases = if aliases.is_empty() {
  String::new()
  } else {
@@ -2147,12 +2134,11 @@ fn sidebar_struct(cx: &Context<'_>, buf: &mut Buffer, it: &clean::Item, s: &clea
  }
 }
 
-fn get_id_for_impl_on_foreign_type(
- for_: &clean::Type,
- trait_: &clean::Path,
- cx: &Context<'_>,
-) -> String {
- small_url_encode(format!("impl-{:#}-for-{:#}", trait_.print(cx), for_.print(cx)))
+fn get_id_for_impl(for_: &clean::Type, trait_: Option<&clean::Path>, cx: &Context<'_>) -> String {
+ match trait_ {
+ Some(t) => small_url_encode(format!("impl-{:#}-for-{:#}", t.print(cx), for_.print(cx))),
+ None => small_url_encode(format!("impl-{:#}", for_.print(cx))),
+ }
 }
 
 fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String, String)> {
@@ -2161,10 +2147,7 @@ fn extract_for_impl_name(item: &clean::Item, cx: &Context<'_>) -> Option<(String
  i.trait_.as_ref().map(|trait_| {
  // Alternative format produces no URLs,
  // so this parameter does nothing.
- (
- format!("{:#}", i.for_.print(cx)),
- get_id_for_impl_on_foreign_type(&i.for_, trait_, cx),
- )
+ (format!("{:#}", i.for_.print(cx)), get_id_for_impl(&i.for_, Some(trait_), cx))
  })
  }
  _ => None,

src/librustdoc/html/render/print_item.rs

@@ -853,7 +853,6 @@ fn item_trait(w: &mut Buffer, cx: &mut Context<'_>, it: &clean::Item, t: &clean:
  &[],
  ImplRenderingParameters {
  show_def_docs: false,
- is_on_foreign_type: true,
  show_default_items: false,
  show_non_assoc_items: true,
  toggle_open_by_default: false,
@@ -1627,7 +1626,6 @@ fn render_implementor(
  aliases,
  ImplRenderingParameters {
  show_def_docs: false,
- is_on_foreign_type: false,
  show_default_items: false,
  show_non_assoc_items: false,
  toggle_open_by_default: false,

src/test/rustdoc-gui/anchors.goml

@@ -28,7 +28,7 @@ move-cursor-to: "h2#implementations"
 assert-css: ("h2#implementations a.anchor", {"color": "rgb(0, 0, 0)"})
 
 // Same thing with the impl block title.
-move-cursor-to: "#impl"
-assert-css: ("#impl a.anchor", {"color": "rgb(0, 0, 0)"})
+move-cursor-to: "#impl-HeavilyDocumentedStruct"
+assert-css: ("#impl-HeavilyDocumentedStruct a.anchor", {"color": "rgb(0, 0, 0)"})
 
 assert-css: ("#title-for-struct-impl-item-doc", {"margin-left": "0px"})

src/test/rustdoc-gui/headers-color.goml

@@ -23,9 +23,9 @@ assert-css: (
  ALL,
 )
 
-goto: file://|DOC_PATH|/test_docs/struct.Foo.html#impl
+goto: file://|DOC_PATH|/test_docs/struct.Foo.html#impl-Foo
 assert-css: (
- "#impl",
+ "#impl-Foo",
  {"color": "rgb(197, 197, 197)", "background-color": "rgba(255, 236, 164, 0.06)"},
 )
 
@@ -62,9 +62,9 @@ assert-css: (
  ALL,
 )
 
-goto: file://|DOC_PATH|/test_docs/struct.Foo.html#impl
+goto: file://|DOC_PATH|/test_docs/struct.Foo.html#impl-Foo
 assert-css: (
- "#impl",
+ "#impl-Foo",
  {"color": "rgb(221, 221, 221)", "background-color": "rgb(73, 74, 61)"},
 )
 
@@ -99,8 +99,8 @@ assert-css: (
  ALL,
 )
 
-goto: file://|DOC_PATH|/test_docs/struct.Foo.html#impl
-assert-css: ("#impl", {"color": "rgb(0, 0, 0)", "background-color": "rgb(253, 255, 211)"})
+goto: file://|DOC_PATH|/test_docs/struct.Foo.html#impl-Foo
+assert-css: ("#impl-Foo", {"color": "rgb(0, 0, 0)", "background-color": "rgb(253, 255, 211)"})
 
 goto: file://|DOC_PATH|/test_docs/struct.Foo.html#method.must_use
 assert-css: (

src/test/rustdoc-gui/headings.goml

@@ -32,8 +32,8 @@ assert-css: ("h4#sub-heading-for-field", {"border-bottom-width": "0px"})
 assert-css: ("h2#implementations", {"font-size": "22px"})
 assert-css: ("h2#implementations", {"border-bottom-width": "1px"})
 
-assert-css: ("#impl > h3.code-header", {"font-size": "18px"})
-assert-css: ("#impl > h3.code-header", {"border-bottom-width": "0px"})
+assert-css: ("#impl-HeavilyDocumentedStruct > h3.code-header", {"font-size": "18px"})
+assert-css: ("#impl-HeavilyDocumentedStruct > h3.code-header", {"border-bottom-width": "0px"})
 assert-css: ("#method\.do_nothing > h4.code-header", {"font-size": "16px"})
 assert-css: ("#method\.do_nothing > h4.code-header", {"border-bottom-width": "0px"})
 
@@ -87,8 +87,8 @@ assert-css: ("h6#structy-prose-sub-heading", {"border-bottom-width": "0px"})
 assert-css: ("h2#implementations", {"font-size": "22px"})
 assert-css: ("h2#implementations", {"border-bottom-width": "1px"})
 
-assert-css: ("#impl > h3.code-header", {"font-size": "18px"})
-assert-css: ("#impl > h3.code-header", {"border-bottom-width": "0px"})
+assert-css: ("#impl-HeavilyDocumentedEnum > h3.code-header", {"font-size": "18px"})
+assert-css: ("#impl-HeavilyDocumentedEnum > h3.code-header", {"border-bottom-width": "0px"})
 assert-css: ("#method\.do_nothing > h4.code-header", {"font-size": "16px"})
 assert-css: ("#method\.do_nothing > h4.code-header", {"border-bottom-width": "0px"})
 
@@ -129,8 +129,8 @@ assert-css: ("h4#sub-heading-for-union-variant", {"border-bottom-width": "0px"})
 assert-css: ("h2#implementations", {"font-size": "22px"})
 assert-css: ("h2#implementations", {"border-bottom-width": "1px"})
 
-assert-css: ("#impl > h3.code-header", {"font-size": "18px"})
-assert-css: ("#impl > h3.code-header", {"border-bottom-width": "0px"})
+assert-css: ("#impl-HeavilyDocumentedUnion > h3.code-header", {"font-size": "18px"})
+assert-css: ("#impl-HeavilyDocumentedUnion > h3.code-header", {"border-bottom-width": "0px"})
 assert-css: ("h4#title-for-union-impl-doc", {"font-size": "16px"})
 assert-css: ("h4#title-for-union-impl-doc", {"border-bottom-width": "0px"})
 assert-css: ("h5#sub-heading-for-union-impl-doc", {"font-size": "16px"})

src/test/rustdoc-gui/implementors.goml

@@ -6,8 +6,8 @@ assert: "#implementors-list"
 assert-count: ("#implementors-list .impl", 2)
 // Now we check that both implementors have an anchor, an ID and a similar DOM.
 assert: ("#implementors-list .impl:nth-child(1) > a.anchor")
-assert-attribute: ("#implementors-list .impl:nth-child(1)", {"id": "impl-Whatever"})
-assert-attribute: ("#implementors-list .impl:nth-child(1) > a.anchor", {"href": "#impl-Whatever"})
+assert-attribute: ("#implementors-list .impl:nth-child(1)", {"id": "impl-Whatever-for-Struct"})
+assert-attribute: ("#implementors-list .impl:nth-child(1) > a.anchor", {"href": "#impl-Whatever-for-Struct"})
 assert: "#implementors-list .impl:nth-child(1) > .code-header.in-band"
 
 assert: ("#implementors-list .impl:nth-child(2) > a.anchor")

src/test/rustdoc-gui/toggle-click-deadspace.goml

@@ -8,5 +8,5 @@ click: ".impl-items .rustdoc-toggle summary::before" // This is the position of
 assert-attribute-false: (".impl-items .rustdoc-toggle", {"open": ""})
 
 // Click the "Trait" part of "impl Trait" and verify it navigates.
-click: "#impl-Trait h3 a:first-of-type"
+click: "#impl-Trait-for-Foo h3 a:first-of-type"
 assert-text: (".fqn .in-band", "Trait lib2::Trait")

src/test/rustdoc/blanket-reexport-item.rs

@@ -1,6 +1,6 @@
 #![crate_name = "foo"]
 
-// @has foo/struct.S.html '//*[@id="impl-Into%3CU%3E"]//h3[@class="code-header in-band"]' 'impl<T, U> Into<U> for T'
+// @has foo/struct.S.html '//*[@id="impl-Into%3CU%3E-for-S"]//h3[@class="code-header in-band"]' 'impl<T, U> Into<U> for T'
 pub struct S2 {}
 mod m {
  pub struct S {}

src/test/rustdoc/const-generics/const-generics-docs.rs

@@ -36,7 +36,7 @@ pub struct Foo<const N: usize> where u8: Trait<N>;
 // @has foo/struct.Bar.html '//pre[@class="rust struct"]' 'pub struct Bar<T, const N: usize>(_)'
 pub struct Bar<T, const N: usize>([T; N]);
 
-// @has foo/struct.Foo.html '//*[@id="impl"]/h3[@class="code-header in-band"]' 'impl<const M: usize> Foo<M> where u8: Trait<M>'
+// @has foo/struct.Foo.html '//*[@id="impl-Foo%3CM%3E"]/h3[@class="code-header in-band"]' 'impl<const M: usize> Foo<M> where u8: Trait<M>'
 impl<const M: usize> Foo<M> where u8: Trait<M> {
  // @has - '//*[@id="associatedconstant.FOO_ASSOC"]' 'pub const FOO_ASSOC: usize'
  pub const FOO_ASSOC: usize = M + 13;
@@ -47,7 +47,7 @@ impl<const M: usize> Foo<M> where u8: Trait<M> {
  }
 }
 
-// @has foo/struct.Bar.html '//*[@id="impl"]/h3[@class="code-header in-band"]' 'impl<const M: usize> Bar<u8, M>'
+// @has foo/struct.Bar.html '//*[@id="impl-Bar%3Cu8%2C%20M%3E"]/h3[@class="code-header in-band"]' 'impl<const M: usize> Bar<u8, M>'
 impl<const M: usize> Bar<u8, M> {
  // @has - '//*[@id="method.hey"]' \
  // 'pub fn hey<const N: usize>(&self) -> Foo<N> where u8: Trait<N>'

src/test/rustdoc/const-generics/const-impl.rs

@@ -9,20 +9,20 @@ pub enum Order {
 }
 
 // @has foo/struct.VSet.html '//pre[@class="rust struct"]' 'pub struct VSet<T, const ORDER: Order>'
-// @has foo/struct.VSet.html '//*[@id="impl-Send"]/h3[@class="code-header in-band"]' 'impl<T, const ORDER: Order> Send for VSet<T, ORDER>'
-// @has foo/struct.VSet.html '//*[@id="impl-Sync"]/h3[@class="code-header in-band"]' 'impl<T, const ORDER: Order> Sync for VSet<T, ORDER>'
+// @has foo/struct.VSet.html '//*[@id="impl-Send-for-VSet%3CT%2C%20ORDER%3E"]/h3[@class="code-header in-band"]' 'impl<T, const ORDER: Order> Send for VSet<T, ORDER>'
+// @has foo/struct.VSet.html '//*[@id="impl-Sync-for-VSet%3CT%2C%20ORDER%3E"]/h3[@class="code-header in-band"]' 'impl<T, const ORDER: Order> Sync for VSet<T, ORDER>'
 pub struct VSet<T, const ORDER: Order> {
  inner: Vec<T>,
 }
 
-// @has foo/struct.VSet.html '//*[@id="impl"]/h3[@class="code-header in-band"]' 'impl<T> VSet<T, { Order::Sorted }>'
+// @has foo/struct.VSet.html '//*[@id="impl-VSet%3CT%2C%20{%20Order%3A%3ASorted%20}%3E"]/h3[@class="code-header in-band"]' 'impl<T> VSet<T, { Order::Sorted }>'
 impl<T> VSet<T, { Order::Sorted }> {
  pub fn new() -> Self {
  Self { inner: Vec::new() }
  }
 }
 
-// @has foo/struct.VSet.html '//*[@id="impl-1"]/h3[@class="code-header in-band"]' 'impl<T> VSet<T, { Order::Unsorted }>'
+// @has foo/struct.VSet.html '//*[@id="impl-VSet%3CT%2C%20{%20Order%3A%3AUnsorted%20}%3E"]/h3[@class="code-header in-band"]' 'impl<T> VSet<T, { Order::Unsorted }>'
 impl<T> VSet<T, { Order::Unsorted }> {
  pub fn new() -> Self {
  Self { inner: Vec::new() }
@@ -31,7 +31,7 @@ impl<T> VSet<T, { Order::Unsorted }> {
 
 pub struct Escape<const S: &'static str>;
 
-// @has foo/struct.Escape.html '//*[@id="impl"]/h3[@class="code-header in-band"]' 'impl Escape<r#"<script>alert("Escape");</script>"#>'
+// @has foo/struct.Escape.html '//*[@id="impl-Escape%3Cr#%22%3Cscript%3Ealert(%22Escape%22)%3B%3C/script%3E%22#%3E"]/h3[@class="code-header in-band"]' 'impl Escape<r#"<script>alert("Escape");</script>"#>'
 impl Escape<r#"<script>alert("Escape");</script>"#> {
  pub fn f() {}
 }