Auto merge of #89262 - Manishearth:rollup-vtkbetm, r=Manishearth

Rollup of 7 pull requests

Successful merges:

 - #88895 (rustdoc: Cleanup `clean` part 2)
 - #88973 (Expose the std_detect env_override feature)
 - #89010 (Add some intra doc links)
 - #89198 (rustdoc: Don't show hidden trait methods)
 - #89216 (Consistent big O notation)
 - #89224 (Change the order of imports suggestions)
 - #89256 (Fix typo in release notes)

Failed merges:

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

Author: bors

Diff for: RELEASES.md

@@ -17,7 +17,7 @@ Compiler
 
 - [Upgrade to LLVM 13.][rust#87570]
 - [Support memory, address, and thread sanitizers on aarch64-unknown-freebsd.][rust#88023]
-- [Allow specifying an deployment target version for all iOS targets][rust#87699]
+- [Allow specifying a deployment target version for all iOS targets][rust#87699]
 - [Warnings can be forced on with `--force-warn`.][rust#87472]
   This feature is primarily intended for usage by `cargo fix`, rather than end users.
 - [Promote `aarch64-apple-ios-sim` to Tier 2\*.][rust#87760]
@@ -5170,7 +5170,7 @@ Libraries
 - [Upgrade to Unicode 10.0.0][42999]
 - [Reimplemented `{f32, f64}::{min, max}` in Rust instead of using CMath.][42430]
 - [Skip the main thread's manual stack guard on Linux][43072]
-- [Iterator::nth for `ops::{Range, RangeFrom}` is now done in O(1) time][43077]
+- [Iterator::nth for `ops::{Range, RangeFrom}` is now done in *O*(1) time][43077]
 - [`#[repr(align(N))]` attribute max number is now 2^31 - 1.][43097] This was
   previously 2^15.
 - [`{OsStr, Path}::Display` now avoids allocations where possible][42613]
@@ -8473,7 +8473,7 @@ Libraries
   algorithm][s].
 * [`std::io::copy` allows `?Sized` arguments][cc].
 * The `Windows`, `Chunks`, and `ChunksMut` iterators over slices all
-  [override `count`, `nth` and `last` with an O(1)
+  [override `count`, `nth` and `last` with an *O*(1)
   implementation][it].
 * [`Default` is implemented for arrays up to `[T; 32]`][d].
 * [`IntoRawFd` has been added to the Unix-specific prelude,
@@ -8995,7 +8995,7 @@ Libraries
 * The `Default` implementation for `Arc` [no longer requires `Sync +
   Send`][arc].
 * [The `Iterator` methods `count`, `nth`, and `last` have been
-  overridden for slices to have O(1) performance instead of O(n)][si].
+  overridden for slices to have *O*(1) performance instead of *O*(*n*)][si].
 * Incorrect handling of paths on Windows has been improved in both the
   compiler and the standard library.
 * [`AtomicPtr` gained a `Default` implementation][ap].

Diff for: compiler/rustc_data_structures/src/graph/scc/mod.rs

@@ -3,7 +3,7 @@
 //! Also computes as the resulting DAG if each SCC is replaced with a
 //! node in the graph. This uses [Tarjan's algorithm](
 //! https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm)
-//! that completes in *O(n)* time.
+//! that completes in *O*(*n*) time.
 
 use crate::fx::FxHashSet;
 use crate::graph::vec_graph::VecGraph;

Diff for: compiler/rustc_data_structures/src/sorted_map.rs

@@ -9,7 +9,7 @@ mod index_map;
 pub use index_map::SortedIndexMultiMap;
 
 /// `SortedMap` is a data structure with similar characteristics as BTreeMap but
-/// slightly different trade-offs: lookup, insertion, and removal are O(log(N))
+/// slightly different trade-offs: lookup, insertion, and removal are *O*(log(*n*))
 /// and elements can be iterated in order cheaply.
 ///
 /// `SortedMap` can be faster than a `BTreeMap` for small sizes (<50) since it

Diff for: compiler/rustc_resolve/src/diagnostics.rs

@@ -1706,6 +1706,9 @@ crate fn show_candidates(
         candidates.iter().map(|c| path_names_to_string(&c.path)).collect();
 
     path_strings.sort();
+    let core_path_strings =
+        path_strings.drain_filter(|p| p.starts_with("core::")).collect::<Vec<String>>();
+    path_strings.extend(core_path_strings);
     path_strings.dedup();
 
     let (determiner, kind) = if candidates.len() == 1 {

Diff for: compiler/rustc_resolve/src/lib.rs

@@ -10,6 +10,7 @@
 
 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/nightly-rustc/")]
 #![feature(box_patterns)]
+#![feature(drain_filter)]
 #![feature(bool_to_option)]
 #![feature(crate_visibility_modifier)]
 #![feature(format_args_capture)]

Diff for: library/alloc/src/collections/binary_heap.rs

@@ -3,7 +3,7 @@
 //! Insertion and popping the largest element have *O*(log(*n*)) time complexity.
 //! Checking the largest element is *O*(1). Converting a vector to a binary heap
 //! can be done in-place, and has *O*(*n*) complexity. A binary heap can also be
-//! converted to a sorted vector in-place, allowing it to be used for an *O*(*n* \* log(*n*))
+//! converted to a sorted vector in-place, allowing it to be used for an *O*(*n* * log(*n*))
 //! in-place heapsort.
 //!
 //! # Examples
@@ -159,9 +159,9 @@ use super::SpecExtend;
 /// This will be a max-heap.
 ///
 /// It is a logic error for an item to be modified in such a way that the
-/// item's ordering relative to any other item, as determined by the `Ord`
+/// item's ordering relative to any other item, as determined by the [`Ord`]
 /// trait, changes while it is in the heap. This is normally only possible
-/// through `Cell`, `RefCell`, global state, I/O, or unsafe code. The
+/// through [`Cell`], [`RefCell`], global state, I/O, or unsafe code. The
 /// behavior resulting from such a logic error is not specified, but will
 /// not result in undefined behavior. This could include panics, incorrect
 /// results, aborts, memory leaks, and non-termination.
@@ -219,7 +219,7 @@ use super::SpecExtend;
 ///
 /// ## Min-heap
 ///
-/// Either `std::cmp::Reverse` or a custom `Ord` implementation can be used to
+/// Either [`core::cmp::Reverse`] or a custom [`Ord`] implementation can be used to
 /// make `BinaryHeap` a min-heap. This makes `heap.pop()` return the smallest
 /// value instead of the greatest one.
 ///
@@ -243,13 +243,17 @@ use super::SpecExtend;
 ///
 /// # Time complexity
 ///
-/// | [push] | [pop]     | [peek]/[peek\_mut] |
-/// |--------|-----------|--------------------|
-/// | O(1)~  | *O*(log(*n*)) | *O*(1)               |
+/// | [push]  | [pop]         | [peek]/[peek\_mut] |
+/// |---------|---------------|--------------------|
+/// | *O*(1)~ | *O*(log(*n*)) | *O*(1)             |
 ///
 /// The value for `push` is an expected cost; the method documentation gives a
 /// more detailed analysis.
 ///
+/// [`core::cmp::Reverse`]: core::cmp::Reverse
+/// [`Ord`]: core::cmp::Ord
+/// [`Cell`]: core::cell::Cell
+/// [`RefCell`]: core::cell::RefCell
 /// [push]: BinaryHeap::push
 /// [pop]: BinaryHeap::pop
 /// [peek]: BinaryHeap::peek
@@ -1255,9 +1259,10 @@ impl<T> FusedIterator for Iter<'_, T> {}
 /// An owning iterator over the elements of a `BinaryHeap`.
 ///
 /// This `struct` is created by [`BinaryHeap::into_iter()`]
-/// (provided by the `IntoIterator` trait). See its documentation for more.
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
 ///
 /// [`into_iter`]: BinaryHeap::into_iter
+/// [`IntoIterator`]: core::iter::IntoIterator
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Clone)]
 pub struct IntoIter<T> {

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

@@ -326,9 +326,10 @@ impl<K: fmt::Debug, V: fmt::Debug> fmt::Debug for IterMut<'_, K, V> {
 /// An owning iterator over the entries of a `BTreeMap`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`BTreeMap`]
-/// (provided by the `IntoIterator` trait). See its documentation for more.
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
 ///
 /// [`into_iter`]: IntoIterator::into_iter
+/// [`IntoIterator`]: core::iter::IntoIterator
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<K, V> {
     range: LazyLeafRange<marker::Dying, K, V>,

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

@@ -107,9 +107,10 @@ impl<T: fmt::Debug> fmt::Debug for Iter<'_, T> {
 /// An owning iterator over the items of a `BTreeSet`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`BTreeSet`]
-/// (provided by the `IntoIterator` trait). See its documentation for more.
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
 ///
 /// [`into_iter`]: BTreeSet#method.into_iter
+/// [`IntoIterator`]: core::iter::IntoIterator
 #[stable(feature = "rust1", since = "1.0.0")]
 #[derive(Debug)]
 pub struct IntoIter<T> {

Diff for: library/alloc/src/collections/linked_list.rs

@@ -38,9 +38,12 @@ mod tests;
 /// let list = LinkedList::from([1, 2, 3]);
 /// ```
 ///
-/// NOTE: It is almost always better to use `Vec` or `VecDeque` because
+/// NOTE: It is almost always better to use [`Vec`] or [`VecDeque`] because
 /// array-based containers are generally faster,
 /// more memory efficient, and make better use of CPU cache.
+///
+/// [`Vec`]: crate::vec::Vec
+/// [`VecDeque`]: super::vec_deque::VecDeque
 #[stable(feature = "rust1", since = "1.0.0")]
 #[cfg_attr(not(test), rustc_diagnostic_item = "LinkedList")]
 pub struct LinkedList<T> {
@@ -121,9 +124,10 @@ impl<T: fmt::Debug> fmt::Debug for IterMut<'_, T> {
 /// An owning iterator over the elements of a `LinkedList`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`LinkedList`]
-/// (provided by the `IntoIterator` trait). See its documentation for more.
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
 ///
 /// [`into_iter`]: LinkedList::into_iter
+/// [`IntoIterator`]: core::iter::IntoIterator
 #[derive(Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<T> {

Diff for: library/alloc/src/collections/vec_deque/into_iter.rs

@@ -8,9 +8,10 @@ use super::VecDeque;
 /// An owning iterator over the elements of a `VecDeque`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`VecDeque`]
-/// (provided by the `IntoIterator` trait). See its documentation for more.
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
 ///
 /// [`into_iter`]: VecDeque::into_iter
+/// [`IntoIterator`]: core::iter::IntoIterator
 #[derive(Clone)]
 #[stable(feature = "rust1", since = "1.0.0")]
 pub struct IntoIter<

Diff for: library/alloc/src/vec/mod.rs

@@ -1,8 +1,8 @@
 //! A contiguous growable array type with heap-allocated contents, written
 //! `Vec<T>`.
 //!
-//! Vectors have `O(1)` indexing, amortized `O(1)` push (to the end) and
-//! `O(1)` pop (from the end).
+//! Vectors have *O*(1) indexing, amortized *O*(1) push (to the end) and
+//! *O*(1) pop (from the end).
 //!
 //! Vectors ensure they never allocate more than `isize::MAX` bytes.
 //!
@@ -1270,7 +1270,7 @@ impl<T, A: Allocator> Vec<T, A> {
     ///
     /// The removed element is replaced by the last element of the vector.
     ///
-    /// This does not preserve ordering, but is O(1).
+    /// This does not preserve ordering, but is *O*(1).
     ///
     /// # Panics
     ///

Diff for: library/core/src/iter/traits/iterator.rs

@@ -1795,10 +1795,11 @@ pub trait Iterator {
     /// The relative order of partitioned items is not maintained.
     ///
     /// # Current implementation
+    ///
     /// Current algorithms tries finding the first element for which the predicate evaluates
     /// to false, and the last element for which it evaluates to true and repeatedly swaps them.
     ///
-    /// Time Complexity: *O*(*N*)
+    /// Time complexity: *O*(*n*)
     ///
     /// See also [`is_partitioned()`] and [`partition()`].
     ///

Diff for: library/std/Cargo.toml

@@ -72,6 +72,7 @@ panic_immediate_abort = ["core/panic_immediate_abort"]
 # https://github.com/rust-lang/stdarch/blob/master/crates/std_detect/Cargo.toml
 std_detect_file_io = ["std_detect/std_detect_file_io"]
 std_detect_dlsym_getauxval = ["std_detect/std_detect_dlsym_getauxval"]
+std_detect_env_override = ["std_detect/std_detect_env_override"]
 
 [package.metadata.fortanix-sgx]
 # Maximum possible number of threads when testing

Diff for: library/std/src/collections/hash/map.rs

@@ -1257,9 +1257,10 @@ impl<'a, K, V> IterMut<'a, K, V> {
 /// An owning iterator over the entries of a `HashMap`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`HashMap`]
-/// (provided by the `IntoIterator` trait). See its documentation for more.
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
 ///
 /// [`into_iter`]: IntoIterator::into_iter
+/// [`IntoIterator`]: crate::iter::IntoIterator
 ///
 /// # Example
 ///

Diff for: library/std/src/collections/hash/set.rs

@@ -1237,9 +1237,10 @@ pub struct Iter<'a, K: 'a> {
 /// An owning iterator over the items of a `HashSet`.
 ///
 /// This `struct` is created by the [`into_iter`] method on [`HashSet`]
-/// (provided by the `IntoIterator` trait). See its documentation for more.
+/// (provided by the [`IntoIterator`] trait). See its documentation for more.
 ///
 /// [`into_iter`]: IntoIterator::into_iter
+/// [`IntoIterator`]: crate::iter::IntoIterator
 ///
 /// # Examples
 ///

Diff for: library/std/src/collections/mod.rs

@@ -97,11 +97,11 @@
 //!
 //! ## Sequences
 //!
-//! |                | get(i)         | insert(i)       | remove(i)      | append | split_off(i)   |
-//! |----------------|----------------|-----------------|----------------|--------|----------------|
-//! | [`Vec`]        | O(1)           | O(n-i)*         | O(n-i)         | O(m)*  | O(n-i)         |
-//! | [`VecDeque`]   | O(1)           | O(min(i, n-i))* | O(min(i, n-i)) | O(m)*  | O(min(i, n-i)) |
-//! | [`LinkedList`] | O(min(i, n-i)) | O(min(i, n-i))  | O(min(i, n-i)) | O(1)   | O(min(i, n-i)) |
+//! |                | get(i)                 | insert(i)               | remove(i)              | append    | split_off(i)           |
+//! |----------------|------------------------|-------------------------|------------------------|-----------|------------------------|
+//! | [`Vec`]        | *O*(1)                 | *O*(*n*-*i*)*           | *O*(*n*-*i*)           | *O*(*m*)* | *O*(*n*-*i*)           |
+//! | [`VecDeque`]   | *O*(1)                 | *O*(min(*i*, *n*-*i*))* | *O*(min(*i*, *n*-*i*)) | *O*(*m*)* | *O*(min(*i*, *n*-*i*)) |
+//! | [`LinkedList`] | *O*(min(*i*, *n*-*i*)) | *O*(min(*i*, *n*-*i*))  | *O*(min(*i*, *n*-*i*)) | *O*(1)    | *O*(min(*i*, *n*-*i*)) |
 //!
 //! Note that where ties occur, [`Vec`] is generally going to be faster than [`VecDeque`], and
 //! [`VecDeque`] is generally going to be faster than [`LinkedList`].
@@ -110,10 +110,10 @@
 //!
 //! For Sets, all operations have the cost of the equivalent Map operation.
 //!
-//! |              | get       | insert    | remove    | range     | append |
-//! |--------------|-----------|-----------|-----------|-----------|--------|
-//! | [`HashMap`]  | O(1)~     | O(1)~*    | O(1)~     | N/A       | N/A    |
-//! | [`BTreeMap`] | O(log(n)) | O(log(n)) | O(log(n)) | O(log(n)) | O(n+m) |
+//! |              | get           | insert        | remove        | range         | append       |
+//! |--------------|---------------|---------------|---------------|---------------|--------------|
+//! | [`HashMap`]  | *O*(1)~       | *O*(1)~*      | *O*(1)~       | N/A           | N/A          |
+//! | [`BTreeMap`] | *O*(log(*n*)) | *O*(log(*n*)) | *O*(log(*n*)) | *O*(log(*n*)) | *O*(*n*+*m*) |
 //!
 //! # Correct and Efficient Usage of Collections
 //!

Diff for: library/std/src/ffi/mod.rs

@@ -43,8 +43,8 @@
 //! terminator, so the buffer length is really `len+1` characters.
 //! Rust strings don't have a nul terminator; their length is always
 //! stored and does not need to be calculated. While in Rust
-//! accessing a string's length is a `O(1)` operation (because the
-//! length is stored); in C it is an `O(length)` operation because the
+//! accessing a string's length is an *O*(1) operation (because the
+//! length is stored); in C it is an *O*(*n*) operation because the
 //! length needs to be computed by scanning the string for the nul
 //! terminator.
 //!

Diff for: library/test/Cargo.toml

@@ -33,3 +33,4 @@ panic_immediate_abort = ["std/panic_immediate_abort"]
 profiler = ["std/profiler"]
 std_detect_file_io = ["std/std_detect_file_io"]
 std_detect_dlsym_getauxval = ["std/std_detect_dlsym_getauxval"]
+std_detect_env_override = ["std/std_detect_env_override"]

Diff for: src/librustdoc/clean/auto_trait.rs

@@ -354,7 +354,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                     let (poly_trait, output) =
                         (data.0.as_ref().unwrap().clone(), data.1.as_ref().cloned().map(Box::new));
                     let new_ty = match poly_trait.trait_ {
-                        Type::ResolvedPath { ref path, ref did, ref is_generic } => {
+                        Type::ResolvedPath { ref path, ref did } => {
                             let mut new_path = path.clone();
                             let last_segment =
                                 new_path.segments.pop().expect("segments were empty");
@@ -389,11 +389,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                                 .segments
                                 .push(PathSegment { name: last_segment.name, args: new_params });
 
-                            Type::ResolvedPath {
-                                path: new_path,
-                                did: *did,
-                                is_generic: *is_generic,
-                            }
+                            Type::ResolvedPath { path: new_path, did: *did }
                         }
                         _ => panic!("Unexpected data: {:?}, {:?}", ty, data),
                     };
@@ -563,11 +559,7 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                         Type::QPath { name: left_name, ref self_type, ref trait_, .. } => {
                             let ty = &*self_type;
                             match **trait_ {
-                                Type::ResolvedPath {
-                                    path: ref trait_path,
-                                    ref did,
-                                    ref is_generic,
-                                } => {
+                                Type::ResolvedPath { path: ref trait_path, ref did } => {
                                     let mut new_trait_path = trait_path.clone();
 
                                     if self.is_fn_ty(trait_) && left_name == sym::Output {
@@ -612,7 +604,6 @@ impl<'a, 'tcx> AutoTraitFinder<'a, 'tcx> {
                                             trait_: Type::ResolvedPath {
                                                 path: new_trait_path,
                                                 did: *did,
-                                                is_generic: *is_generic,
                                             },
                                             generic_params: Vec::new(),
                                         },

Diff for: src/librustdoc/clean/inline.rs

@@ -389,13 +389,45 @@ crate fn build_impl(
         }
     }
 
+    let document_hidden = cx.render_options.document_hidden;
     let predicates = tcx.explicit_predicates_of(did);
     let (trait_items, generics) = match impl_item {
         Some(impl_) => (
             impl_
                 .items
                 .iter()
-                .map(|item| tcx.hir().impl_item(item.id).clean(cx))
+                .map(|item| tcx.hir().impl_item(item.id))
+                .filter(|item| {
+                    // Filter out impl items whose corresponding trait item has `doc(hidden)`
+                    // not to document such impl items.
+                    // For inherent impls, we don't do any filtering, because that's already done in strip_hidden.rs.
+
+                    // When `--document-hidden-items` is passed, we don't
+                    // do any filtering, too.
+                    if document_hidden {
+                        return true;
+                    }
+                    if let Some(associated_trait) = associated_trait {
+                        let assoc_kind = match item.kind {
+                            hir::ImplItemKind::Const(..) => ty::AssocKind::Const,
+                            hir::ImplItemKind::Fn(..) => ty::AssocKind::Fn,
+                            hir::ImplItemKind::TyAlias(..) => ty::AssocKind::Type,
+                        };
+                        let trait_item = tcx
+                            .associated_items(associated_trait.def_id)
+                            .find_by_name_and_kind(
+                                tcx,
+                                item.ident,
+                                assoc_kind,
+                                associated_trait.def_id,
+                            )
+                            .unwrap(); // SAFETY: For all impl items there exists trait item that has the same name.
+                        !tcx.get_attrs(trait_item.def_id).lists(sym::doc).has_word(sym::hidden)
+                    } else {
+                        true
+                    }
+                })
+                .map(|item| item.clean(cx))
                 .collect::<Vec<_>>(),
             impl_.generics.clean(cx),
         ),