Rollup merge of #135367 - Urgau:unreach_pub-std-3, r=Noratrieb

Enable `unreachable_pub` lint in `alloc`

This PR enables the [`unreachable_pub`](https://doc.rust-lang.org/rustc/lints/listing/allowed-by-default.html#unreachable-pub) lint as warn in the `alloc` crate.

Most of changes are in the btree implementation and in tests.

*The diff was mostly generated with `./x.py fix --stage 1 library/alloc/ -- --broken-code`, as well as manual edits for code in macros and in tests.*

Continuation of #134286 and #135366

r? libs

Author: matthiaskrgr

library/alloc/src/collections/btree/append.rs

@@ -16,7 +16,7 @@ impl<K, V> Root<K, V> {
     /// a `BTreeMap`, both iterators should produce keys in strictly ascending
     /// order, each greater than all keys in the tree, including any keys
     /// already in the tree upon entry.
-    pub fn append_from_sorted_iters<I, A: Allocator + Clone>(
+    pub(super) fn append_from_sorted_iters<I, A: Allocator + Clone>(
         &mut self,
         left: I,
         right: I,
@@ -36,8 +36,12 @@ impl<K, V> Root<K, V> {
     /// Pushes all key-value pairs to the end of the tree, incrementing a
     /// `length` variable along the way. The latter makes it easier for the
     /// caller to avoid a leak when the iterator panicks.
-    pub fn bulk_push<I, A: Allocator + Clone>(&mut self, iter: I, length: &mut usize, alloc: A)
-    where
+    pub(super) fn bulk_push<I, A: Allocator + Clone>(
+        &mut self,
+        iter: I,
+        length: &mut usize,
+        alloc: A,
+    ) where
         I: Iterator<Item = (K, V)>,
     {
         let mut cur_node = self.borrow_mut().last_leaf_edge().into_node();

library/alloc/src/collections/btree/borrow.rs

@@ -11,7 +11,7 @@ use core::ptr::NonNull;
 /// the compiler to follow. A `DormantMutRef` allows you to check borrowing
 /// yourself, while still expressing its stacked nature, and encapsulating
 /// the raw pointer code needed to do this without undefined behavior.
-pub struct DormantMutRef<'a, T> {
+pub(super) struct DormantMutRef<'a, T> {
     ptr: NonNull<T>,
     _marker: PhantomData<&'a mut T>,
 }
@@ -23,7 +23,7 @@ impl<'a, T> DormantMutRef<'a, T> {
     /// Capture a unique borrow, and immediately reborrow it. For the compiler,
     /// the lifetime of the new reference is the same as the lifetime of the
     /// original reference, but you promise to use it for a shorter period.
-    pub fn new(t: &'a mut T) -> (&'a mut T, Self) {
+    pub(super) fn new(t: &'a mut T) -> (&'a mut T, Self) {
         let ptr = NonNull::from(t);
         // SAFETY: we hold the borrow throughout 'a via `_marker`, and we expose
         // only this reference, so it is unique.
@@ -37,7 +37,7 @@ impl<'a, T> DormantMutRef<'a, T> {
     ///
     /// The reborrow must have ended, i.e., the reference returned by `new` and
     /// all pointers and references derived from it, must not be used anymore.
-    pub unsafe fn awaken(self) -> &'a mut T {
+    pub(super) unsafe fn awaken(self) -> &'a mut T {
         // SAFETY: our own safety conditions imply this reference is again unique.
         unsafe { &mut *self.ptr.as_ptr() }
     }
@@ -48,7 +48,7 @@ impl<'a, T> DormantMutRef<'a, T> {
     ///
     /// The reborrow must have ended, i.e., the reference returned by `new` and
     /// all pointers and references derived from it, must not be used anymore.
-    pub unsafe fn reborrow(&mut self) -> &'a mut T {
+    pub(super) unsafe fn reborrow(&mut self) -> &'a mut T {
         // SAFETY: our own safety conditions imply this reference is again unique.
         unsafe { &mut *self.ptr.as_ptr() }
     }
@@ -59,7 +59,7 @@ impl<'a, T> DormantMutRef<'a, T> {
     ///
     /// The reborrow must have ended, i.e., the reference returned by `new` and
     /// all pointers and references derived from it, must not be used anymore.
-    pub unsafe fn reborrow_shared(&self) -> &'a T {
+    pub(super) unsafe fn reborrow_shared(&self) -> &'a T {
         // SAFETY: our own safety conditions imply this reference is again unique.
         unsafe { &*self.ptr.as_ptr() }
     }

library/alloc/src/collections/btree/dedup_sorted_iter.rs

@@ -6,7 +6,7 @@ use core::iter::Peekable;
 /// Used by [`BTreeMap::bulk_build_from_sorted_iter`][1].
 ///
 /// [1]: crate::collections::BTreeMap::bulk_build_from_sorted_iter
-pub struct DedupSortedIter<K, V, I>
+pub(super) struct DedupSortedIter<K, V, I>
 where
     I: Iterator<Item = (K, V)>,
 {
@@ -17,7 +17,7 @@ impl<K, V, I> DedupSortedIter<K, V, I>
 where
     I: Iterator<Item = (K, V)>,
 {
-    pub fn new(iter: I) -> Self {
+    pub(super) fn new(iter: I) -> Self {
         Self { iter: iter.peekable() }
     }
 }

library/alloc/src/collections/btree/fix.rs

@@ -57,7 +57,10 @@ impl<'a, K: 'a, V: 'a> NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal> {
     ///
     /// This method does not expect ancestors to already be underfull upon entry
     /// and panics if it encounters an empty ancestor.
-    pub fn fix_node_and_affected_ancestors<A: Allocator + Clone>(mut self, alloc: A) -> bool {
+    pub(super) fn fix_node_and_affected_ancestors<A: Allocator + Clone>(
+        mut self,
+        alloc: A,
+    ) -> bool {
         loop {
             match self.fix_node_through_parent(alloc.clone()) {
                 Ok(Some(parent)) => self = parent.forget_type(),
@@ -70,7 +73,7 @@ impl<'a, K: 'a, V: 'a> NodeRef<marker::Mut<'a>, K, V, marker::LeafOrInternal> {
 
 impl<K, V> Root<K, V> {
     /// Removes empty levels on the top, but keeps an empty leaf if the entire tree is empty.
-    pub fn fix_top<A: Allocator + Clone>(&mut self, alloc: A) {
+    pub(super) fn fix_top<A: Allocator + Clone>(&mut self, alloc: A) {
         while self.height() > 0 && self.len() == 0 {
             self.pop_internal_level(alloc.clone());
         }
@@ -79,7 +82,7 @@ impl<K, V> Root<K, V> {
     /// Stocks up or merge away any underfull nodes on the right border of the
     /// tree. The other nodes, those that are not the root nor a rightmost edge,
     /// must already have at least MIN_LEN elements.
-    pub fn fix_right_border<A: Allocator + Clone>(&mut self, alloc: A) {
+    pub(super) fn fix_right_border<A: Allocator + Clone>(&mut self, alloc: A) {
         self.fix_top(alloc.clone());
         if self.len() > 0 {
             self.borrow_mut().last_kv().fix_right_border_of_right_edge(alloc.clone());
@@ -88,7 +91,7 @@ impl<K, V> Root<K, V> {
     }
 
     /// The symmetric clone of `fix_right_border`.
-    pub fn fix_left_border<A: Allocator + Clone>(&mut self, alloc: A) {
+    pub(super) fn fix_left_border<A: Allocator + Clone>(&mut self, alloc: A) {
         self.fix_top(alloc.clone());
         if self.len() > 0 {
             self.borrow_mut().first_kv().fix_left_border_of_left_edge(alloc.clone());
@@ -99,7 +102,7 @@ impl<K, V> Root<K, V> {
     /// Stocks up any underfull nodes on the right border of the tree.
     /// The other nodes, those that are neither the root nor a rightmost edge,
     /// must be prepared to have up to MIN_LEN elements stolen.
-    pub fn fix_right_border_of_plentiful(&mut self) {
+    pub(super) fn fix_right_border_of_plentiful(&mut self) {
         let mut cur_node = self.borrow_mut();
         while let Internal(internal) = cur_node.force() {
             // Check if rightmost child is underfull.

library/alloc/src/collections/btree/mem.rs

@@ -6,7 +6,7 @@ use core::{intrinsics, mem, ptr};
 /// If a panic occurs in the `change` closure, the entire process will be aborted.
 #[allow(dead_code)] // keep as illustration and for future use
 #[inline]
-pub fn take_mut<T>(v: &mut T, change: impl FnOnce(T) -> T) {
+pub(super) fn take_mut<T>(v: &mut T, change: impl FnOnce(T) -> T) {
     replace(v, |value| (change(value), ()))
 }
 
@@ -15,7 +15,7 @@ pub fn take_mut<T>(v: &mut T, change: impl FnOnce(T) -> T) {
 ///
 /// If a panic occurs in the `change` closure, the entire process will be aborted.
 #[inline]
-pub fn replace<T, R>(v: &mut T, change: impl FnOnce(T) -> (T, R)) -> R {
+pub(super) fn replace<T, R>(v: &mut T, change: impl FnOnce(T) -> (T, R)) -> R {
     struct PanicGuard;
     impl Drop for PanicGuard {
         fn drop(&mut self) {

library/alloc/src/collections/btree/merge_iter.rs

@@ -4,7 +4,7 @@ use core::iter::FusedIterator;
 
 /// Core of an iterator that merges the output of two strictly ascending iterators,
 /// for instance a union or a symmetric difference.
-pub struct MergeIterInner<I: Iterator> {
+pub(super) struct MergeIterInner<I: Iterator> {
     a: I,
     b: I,
     peeked: Option<Peeked<I>>,
@@ -40,7 +40,7 @@ where
 
 impl<I: Iterator> MergeIterInner<I> {
     /// Creates a new core for an iterator merging a pair of sources.
-    pub fn new(a: I, b: I) -> Self {
+    pub(super) fn new(a: I, b: I) -> Self {
         MergeIterInner { a, b, peeked: None }
     }
 
@@ -51,7 +51,7 @@ impl<I: Iterator> MergeIterInner<I> {
     /// the sources are not strictly ascending). If neither returned option
     /// contains a value, iteration has finished and subsequent calls will
     /// return the same empty pair.
-    pub fn nexts<Cmp: Fn(&I::Item, &I::Item) -> Ordering>(
+    pub(super) fn nexts<Cmp: Fn(&I::Item, &I::Item) -> Ordering>(
         &mut self,
         cmp: Cmp,
     ) -> (Option<I::Item>, Option<I::Item>)
@@ -85,7 +85,7 @@ impl<I: Iterator> MergeIterInner<I> {
     }
 
     /// Returns a pair of upper bounds for the `size_hint` of the final iterator.
-    pub fn lens(&self) -> (usize, usize)
+    pub(super) fn lens(&self) -> (usize, usize)
     where
         I: ExactSizeIterator,
     {

library/alloc/src/collections/btree/mod.rs

@@ -2,13 +2,13 @@ mod append;
 mod borrow;
 mod dedup_sorted_iter;
 mod fix;
-pub mod map;
+pub(super) mod map;
 mod mem;
 mod merge_iter;
 mod navigate;
 mod node;
 mod remove;
 mod search;
-pub mod set;
+pub(super) mod set;
 mod set_val;
 mod split;