Auto merge of rust-lang#103125 - matthiaskrgr:rollup-82xttcl, r=matthiaskrgr

Rollup of 5 pull requests

Successful merges:

 - rust-lang#103087 (Documentation BTreeMap::append's behavior for already existing keys)
 - rust-lang#103089 (Mark derived StructuralEq as automatically derived.)
 - rust-lang#103102 (Clarify the possible return values of `len_utf16`)
 - rust-lang#103109 (PhantomData: inline a macro that is used only once)
 - rust-lang#103120 (rustdoc: Do not expect `doc(primitive)` modules to always exist)

Failed merges:

r? `@ghost`
`@rustbot` modify labels: rollup

Author: bors

Diff for: compiler/rustc_builtin_macros/src/deriving/mod.rs

@@ -131,23 +131,27 @@ fn inject_impl_of_structural_trait(
     // Create generics param list for where clauses and impl headers
     let mut generics = generics.clone();
 
+    let ctxt = span.ctxt();
+
     // Create the type of `self`.
     //
     // in addition, remove defaults from generic params (impls cannot have them).
     let self_params: Vec<_> = generics
         .params
         .iter_mut()
         .map(|param| match &mut param.kind {
-            ast::GenericParamKind::Lifetime => {
-                ast::GenericArg::Lifetime(cx.lifetime(span, param.ident))
-            }
+            ast::GenericParamKind::Lifetime => ast::GenericArg::Lifetime(
+                cx.lifetime(param.ident.span.with_ctxt(ctxt), param.ident),
+            ),
             ast::GenericParamKind::Type { default } => {
                 *default = None;
-                ast::GenericArg::Type(cx.ty_ident(span, param.ident))
+                ast::GenericArg::Type(cx.ty_ident(param.ident.span.with_ctxt(ctxt), param.ident))
             }
             ast::GenericParamKind::Const { ty: _, kw_span: _, default } => {
                 *default = None;
-                ast::GenericArg::Const(cx.const_ident(span, param.ident))
+                ast::GenericArg::Const(
+                    cx.const_ident(param.ident.span.with_ctxt(ctxt), param.ident),
+                )
             }
         })
         .collect();
@@ -174,6 +178,8 @@ fn inject_impl_of_structural_trait(
             })
             .cloned(),
     );
+    // Mark as `automatically_derived` to avoid some silly lints.
+    attrs.push(cx.attribute(cx.meta_word(span, sym::automatically_derived)));
 
     let newitem = cx.item(
         span,

Diff for: library/alloc/src/collections/btree/map.rs

@@ -1093,6 +1093,9 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
 
     /// Moves all elements from `other` into `self`, leaving `other` empty.
     ///
+    /// If a key from `other` is already present in `self`, the respective
+    /// value from `self` will be overwritten with the respective value from `other`.
+    ///
     /// # Examples
     ///
     /// ```
@@ -1101,10 +1104,10 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     /// let mut a = BTreeMap::new();
     /// a.insert(1, "a");
     /// a.insert(2, "b");
-    /// a.insert(3, "c");
+    /// a.insert(3, "c"); // Note: Key (3) also present in b.
     ///
     /// let mut b = BTreeMap::new();
-    /// b.insert(3, "d");
+    /// b.insert(3, "d"); // Note: Key (3) also present in a.
     /// b.insert(4, "e");
     /// b.insert(5, "f");
     ///
@@ -1115,7 +1118,7 @@ impl<K, V, A: Allocator + Clone> BTreeMap<K, V, A> {
     ///
     /// assert_eq!(a[&1], "a");
     /// assert_eq!(a[&2], "b");
-    /// assert_eq!(a[&3], "d");
+    /// assert_eq!(a[&3], "d"); // Note: "c" has been overwritten.
     /// assert_eq!(a[&4], "e");
     /// assert_eq!(a[&5], "f");
     /// ```

Diff for: library/core/src/char/methods.rs

@@ -597,9 +597,14 @@ impl char {
     /// Returns the number of 16-bit code units this `char` would need if
     /// encoded in UTF-16.
     ///
+    /// That number of code units is always either 1 or 2, for unicode scalar values in
+    /// the [basic multilingual plane] or [supplementary planes] respectively.
+    ///
     /// See the documentation for [`len_utf8()`] for more explanation of this
     /// concept. This function is a mirror, but for UTF-16 instead of UTF-8.
     ///
+    /// [basic multilingual plane]: http://www.unicode.org/glossary/#basic_multilingual_plane
+    /// [supplementary planes]: http://www.unicode.org/glossary/#supplementary_planes
     /// [`len_utf8()`]: #method.len_utf8
     ///
     /// # Examples

Diff for: library/core/src/marker.rs

@@ -483,64 +483,6 @@ impl<T: ?Sized> !Sync for *const T {}
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<T: ?Sized> !Sync for *mut T {}
 
-macro_rules! impls {
-    ($t: ident) => {
-        #[stable(feature = "rust1", since = "1.0.0")]
-        impl<T: ?Sized> Hash for $t<T> {
-            #[inline]
-            fn hash<H: Hasher>(&self, _: &mut H) {}
-        }
-
-        #[stable(feature = "rust1", since = "1.0.0")]
-        impl<T: ?Sized> cmp::PartialEq for $t<T> {
-            fn eq(&self, _other: &$t<T>) -> bool {
-                true
-            }
-        }
-
-        #[stable(feature = "rust1", since = "1.0.0")]
-        impl<T: ?Sized> cmp::Eq for $t<T> {}
-
-        #[stable(feature = "rust1", since = "1.0.0")]
-        impl<T: ?Sized> cmp::PartialOrd for $t<T> {
-            fn partial_cmp(&self, _other: &$t<T>) -> Option<cmp::Ordering> {
-                Option::Some(cmp::Ordering::Equal)
-            }
-        }
-
-        #[stable(feature = "rust1", since = "1.0.0")]
-        impl<T: ?Sized> cmp::Ord for $t<T> {
-            fn cmp(&self, _other: &$t<T>) -> cmp::Ordering {
-                cmp::Ordering::Equal
-            }
-        }
-
-        #[stable(feature = "rust1", since = "1.0.0")]
-        impl<T: ?Sized> Copy for $t<T> {}
-
-        #[stable(feature = "rust1", since = "1.0.0")]
-        impl<T: ?Sized> Clone for $t<T> {
-            fn clone(&self) -> Self {
-                Self
-            }
-        }
-
-        #[stable(feature = "rust1", since = "1.0.0")]
-        #[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
-        impl<T: ?Sized> const Default for $t<T> {
-            fn default() -> Self {
-                Self
-            }
-        }
-
-        #[unstable(feature = "structural_match", issue = "31434")]
-        impl<T: ?Sized> StructuralPartialEq for $t<T> {}
-
-        #[unstable(feature = "structural_match", issue = "31434")]
-        impl<T: ?Sized> StructuralEq for $t<T> {}
-    };
-}
-
 /// Zero-sized type used to mark things that "act like" they own a `T`.
 ///
 /// Adding a `PhantomData<T>` field to your type tells the compiler that your
@@ -678,7 +620,59 @@ macro_rules! impls {
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct PhantomData<T: ?Sized>;
 
-impls! { PhantomData }
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: ?Sized> Hash for PhantomData<T> {
+    #[inline]
+    fn hash<H: Hasher>(&self, _: &mut H) {}
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: ?Sized> cmp::PartialEq for PhantomData<T> {
+    fn eq(&self, _other: &PhantomData<T>) -> bool {
+        true
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: ?Sized> cmp::Eq for PhantomData<T> {}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: ?Sized> cmp::PartialOrd for PhantomData<T> {
+    fn partial_cmp(&self, _other: &PhantomData<T>) -> Option<cmp::Ordering> {
+        Option::Some(cmp::Ordering::Equal)
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: ?Sized> cmp::Ord for PhantomData<T> {
+    fn cmp(&self, _other: &PhantomData<T>) -> cmp::Ordering {
+        cmp::Ordering::Equal
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: ?Sized> Copy for PhantomData<T> {}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+impl<T: ?Sized> Clone for PhantomData<T> {
+    fn clone(&self) -> Self {
+        Self
+    }
+}
+
+#[stable(feature = "rust1", since = "1.0.0")]
+#[rustc_const_unstable(feature = "const_default_impls", issue = "87864")]
+impl<T: ?Sized> const Default for PhantomData<T> {
+    fn default() -> Self {
+        Self
+    }
+}
+
+#[unstable(feature = "structural_match", issue = "31434")]
+impl<T: ?Sized> StructuralPartialEq for PhantomData<T> {}
+
+#[unstable(feature = "structural_match", issue = "31434")]
+impl<T: ?Sized> StructuralEq for PhantomData<T> {}
 
 mod impls {
     #[stable(feature = "rust1", since = "1.0.0")]

Diff for: src/librustdoc/passes/collect_intra_doc_links.rs

@@ -80,10 +80,10 @@ impl Res {
         }
     }
 
-    fn def_id(self, tcx: TyCtxt<'_>) -> DefId {
+    fn def_id(self, tcx: TyCtxt<'_>) -> Option<DefId> {
         match self {
-            Res::Def(_, id) => id,
-            Res::Primitive(prim) => *PrimitiveType::primitive_locations(tcx).get(&prim).unwrap(),
+            Res::Def(_, id) => Some(id),
+            Res::Primitive(prim) => PrimitiveType::primitive_locations(tcx).get(&prim).copied(),
         }
     }
 
@@ -1127,10 +1127,10 @@ impl LinkCollector<'_, '_> {
                     }
                 }
 
-                Some(ItemLink {
+                res.def_id(self.cx.tcx).map(|page_id| ItemLink {
                     link: ori_link.link.clone(),
                     link_text: link_text.clone(),
-                    page_id: res.def_id(self.cx.tcx),
+                    page_id,
                     fragment,
                 })
             }

Diff for: src/librustdoc/passes/collect_intra_doc_links/early.rs

@@ -48,7 +48,6 @@ pub(crate) fn early_resolve_intra_doc_links(
     link_resolver.resolve_doc_links_local(&krate.attrs);
     link_resolver.process_module_children_or_reexports(CRATE_DEF_ID.to_def_id());
     visit::walk_crate(&mut link_resolver, krate);
-    link_resolver.process_extern_impls();
 
     // FIXME: somehow rustdoc is still missing crates even though we loaded all
     // the known necessary crates. Load them all unconditionally until we find a way to fix this.
@@ -58,6 +57,8 @@ pub(crate) fn early_resolve_intra_doc_links(
         link_resolver.resolver.resolve_rustdoc_path(extern_name, TypeNS, parent_scope);
     }
 
+    link_resolver.process_extern_impls();
+
     ResolverCaches {
         markdown_links: Some(link_resolver.markdown_links),
         doc_link_resolutions: link_resolver.doc_link_resolutions,

Diff for: src/test/rustdoc/intra-doc/no-doc-primitive.rs

@@ -0,0 +1,15 @@
+// Crate tree without a `doc(primitive)` module for primitive type linked to by a doc link.
+
+#![deny(rustdoc::broken_intra_doc_links)]
+#![feature(no_core, lang_items, rustc_attrs)]
+#![no_core]
+#![rustc_coherence_is_core]
+#![crate_type = "rlib"]
+
+// @has no_doc_primitive/index.html
+//! A [`char`] and its [`char::len_utf8`].
+impl char {
+    pub fn len_utf8(self) -> usize {
+        42
+    }
+}