Auto merge of #126569 - jieyouxu:rollup-1uvkb2y, r=jieyouxu

Rollup of 8 pull requests

Successful merges:

 - #125258 (Resolve elided lifetimes in assoc const to static if no other lifetimes are in scope)
 - #126250 (docs(change): Don't mention a Cargo 2024 edition change for 1.79)
 - #126288 (doc: Added commas where needed)
 - #126346 (export std::os::fd module on HermitOS)
 - #126468 (div_euclid, rem_euclid: clarify/extend documentation)
 - #126531 (Add codegen test for `Request::provide_*`)
 - #126535 (coverage: Arrange span extraction/refinement as a series of passes)
 - #126538 (coverage: Several small improvements to graph code)

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

1 files changed, 46 insertions, 43 deletions

diff --git a/compiler/rustc_mir_transform/src/coverage/graph.rs b/compiler/rustc_mir_transform/src/coverage/graph.rs
index fd74a2a97e2..360dccb240d 100644
--- a/compiler/rustc_mir_transform/src/coverage/graph.rs
+++ b/compiler/rustc_mir_transform/src/coverage/graph.rs
@@ -14,16 +14,16 @@ use std::ops::{Index, IndexMut};
 /// A coverage-specific simplification of the MIR control flow graph (CFG). The `CoverageGraph`s
 /// nodes are `BasicCoverageBlock`s, which encompass one or more MIR `BasicBlock`s.
 #[derive(Debug)]
-pub(super) struct CoverageGraph {
+pub(crate) struct CoverageGraph {
     bcbs: IndexVec<BasicCoverageBlock, BasicCoverageBlockData>,
     bb_to_bcb: IndexVec<BasicBlock, Option<BasicCoverageBlock>>,
-    pub successors: IndexVec<BasicCoverageBlock, Vec<BasicCoverageBlock>>,
-    pub predecessors: IndexVec<BasicCoverageBlock, Vec<BasicCoverageBlock>>,
+    pub(crate) successors: IndexVec<BasicCoverageBlock, Vec<BasicCoverageBlock>>,
+    pub(crate) predecessors: IndexVec<BasicCoverageBlock, Vec<BasicCoverageBlock>>,
     dominators: Option<Dominators<BasicCoverageBlock>>,
 }
 
 impl CoverageGraph {
-    pub fn from_mir(mir_body: &mir::Body<'_>) -> Self {
+    pub(crate) fn from_mir(mir_body: &mir::Body<'_>) -> Self {
         let (bcbs, bb_to_bcb) = Self::compute_basic_coverage_blocks(mir_body);
 
         // Pre-transform MIR `BasicBlock` successors and predecessors into the BasicCoverageBlock
@@ -135,24 +135,28 @@ impl CoverageGraph {
     }
 
     #[inline(always)]
-    pub fn iter_enumerated(
+    pub(crate) fn iter_enumerated(
         &self,
     ) -> impl Iterator<Item = (BasicCoverageBlock, &BasicCoverageBlockData)> {
         self.bcbs.iter_enumerated()
     }
 
     #[inline(always)]
-    pub fn bcb_from_bb(&self, bb: BasicBlock) -> Option<BasicCoverageBlock> {
+    pub(crate) fn bcb_from_bb(&self, bb: BasicBlock) -> Option<BasicCoverageBlock> {
         if bb.index() < self.bb_to_bcb.len() { self.bb_to_bcb[bb] } else { None }
     }
 
     #[inline(always)]
-    pub fn dominates(&self, dom: BasicCoverageBlock, node: BasicCoverageBlock) -> bool {
+    pub(crate) fn dominates(&self, dom: BasicCoverageBlock, node: BasicCoverageBlock) -> bool {
         self.dominators.as_ref().unwrap().dominates(dom, node)
     }
 
     #[inline(always)]
-    pub fn cmp_in_dominator_order(&self, a: BasicCoverageBlock, b: BasicCoverageBlock) -> Ordering {
+    pub(crate) fn cmp_in_dominator_order(
+        &self,
+        a: BasicCoverageBlock,
+        b: BasicCoverageBlock,
+    ) -> Ordering {
         self.dominators.as_ref().unwrap().cmp_in_dominator_order(a, b)
     }
 
@@ -166,7 +170,7 @@ impl CoverageGraph {
     ///
     /// FIXME: That assumption might not be true for [`TerminatorKind::Yield`]?
     #[inline(always)]
-    pub(super) fn bcb_has_multiple_in_edges(&self, bcb: BasicCoverageBlock) -> bool {
+    pub(crate) fn bcb_has_multiple_in_edges(&self, bcb: BasicCoverageBlock) -> bool {
         // Even though bcb0 conceptually has an extra virtual in-edge due to
         // being the entry point, we've already asserted that it has no _other_
         // in-edges, so there's no possibility of it having _multiple_ in-edges.
@@ -212,7 +216,7 @@ impl graph::StartNode for CoverageGraph {
 impl graph::Successors for CoverageGraph {
     #[inline]
     fn successors(&self, node: Self::Node) -> impl Iterator<Item = Self::Node> {
-        self.successors[node].iter().cloned()
+        self.successors[node].iter().copied()
     }
 }
 
@@ -227,7 +231,7 @@ rustc_index::newtype_index! {
     /// A node in the control-flow graph of CoverageGraph.
     #[orderable]
     #[debug_format = "bcb{}"]
-    pub(super) struct BasicCoverageBlock {
+    pub(crate) struct BasicCoverageBlock {
         const START_BCB = 0;
     }
 }
@@ -259,23 +263,23 @@ rustc_index::newtype_index! {
 /// queries (`dominates()`, `predecessors`, `successors`, etc.) have branch (control flow)
 /// significance.
 #[derive(Debug, Clone)]
-pub(super) struct BasicCoverageBlockData {
-    pub basic_blocks: Vec<BasicBlock>,
+pub(crate) struct BasicCoverageBlockData {
+    pub(crate) basic_blocks: Vec<BasicBlock>,
 }
 
 impl BasicCoverageBlockData {
-    pub fn from(basic_blocks: Vec<BasicBlock>) -> Self {
+    fn from(basic_blocks: Vec<BasicBlock>) -> Self {
         assert!(basic_blocks.len() > 0);
         Self { basic_blocks }
     }
 
     #[inline(always)]
-    pub fn leader_bb(&self) -> BasicBlock {
+    pub(crate) fn leader_bb(&self) -> BasicBlock {
         self.basic_blocks[0]
     }
 
     #[inline(always)]
-    pub fn last_bb(&self) -> BasicBlock {
+    pub(crate) fn last_bb(&self) -> BasicBlock {
         *self.basic_blocks.last().unwrap()
     }
 }
@@ -364,7 +368,7 @@ fn bcb_filtered_successors<'a, 'tcx>(terminator: &'a Terminator<'tcx>) -> Covera
 /// CoverageGraph outside all loops. This supports traversing the BCB CFG in a way that
 /// ensures a loop is completely traversed before processing Blocks after the end of the loop.
 #[derive(Debug)]
-pub(super) struct TraversalContext {
+struct TraversalContext {
     /// BCB with one or more incoming loop backedges, indicating which loop
     /// this context is for.
     ///
@@ -375,7 +379,7 @@ pub(super) struct TraversalContext {
     worklist: VecDeque<BasicCoverageBlock>,
 }
 
-pub(super) struct TraverseCoverageGraphWithLoops<'a> {
+pub(crate) struct TraverseCoverageGraphWithLoops<'a> {
     basic_coverage_blocks: &'a CoverageGraph,
 
     backedges: IndexVec<BasicCoverageBlock, Vec<BasicCoverageBlock>>,
@@ -384,7 +388,7 @@ pub(super) struct TraverseCoverageGraphWithLoops<'a> {
 }
 
 impl<'a> TraverseCoverageGraphWithLoops<'a> {
-    pub(super) fn new(basic_coverage_blocks: &'a CoverageGraph) -> Self {
+    pub(crate) fn new(basic_coverage_blocks: &'a CoverageGraph) -> Self {
         let backedges = find_loop_backedges(basic_coverage_blocks);
 
         let worklist = VecDeque::from([basic_coverage_blocks.start_node()]);
@@ -400,7 +404,7 @@ impl<'a> TraverseCoverageGraphWithLoops<'a> {
 
     /// For each loop on the loop context stack (top-down), yields a list of BCBs
     /// within that loop that have an outgoing edge back to the loop header.
-    pub(super) fn reloop_bcbs_per_loop(&self) -> impl Iterator<Item = &[BasicCoverageBlock]> {
+    pub(crate) fn reloop_bcbs_per_loop(&self) -> impl Iterator<Item = &[BasicCoverageBlock]> {
         self.context_stack
             .iter()
             .rev()
@@ -408,39 +412,38 @@ impl<'a> TraverseCoverageGraphWithLoops<'a> {
             .map(|header_bcb| self.backedges[header_bcb].as_slice())
     }
 
-    pub(super) fn next(&mut self) -> Option<BasicCoverageBlock> {
+    pub(crate) fn next(&mut self) -> Option<BasicCoverageBlock> {
         debug!(
             "TraverseCoverageGraphWithLoops::next - context_stack: {:?}",
             self.context_stack.iter().rev().collect::<Vec<_>>()
         );
 
         while let Some(context) = self.context_stack.last_mut() {
-            if let Some(bcb) = context.worklist.pop_front() {
-                if !self.visited.insert(bcb) {
-                    debug!("Already visited: {bcb:?}");
-                    continue;
-                }
-                debug!("Visiting {bcb:?}");
-
-                if self.backedges[bcb].len() > 0 {
-                    debug!("{bcb:?} is a loop header! Start a new TraversalContext...");
-                    self.context_stack.push(TraversalContext {
-                        loop_header: Some(bcb),
-                        worklist: VecDeque::new(),
-                    });
-                }
-                self.add_successors_to_worklists(bcb);
-                return Some(bcb);
-            } else {
-                // Strip contexts with empty worklists from the top of the stack
+            let Some(bcb) = context.worklist.pop_front() else {
+                // This stack level is exhausted; pop it and try the next one.
                 self.context_stack.pop();
+                continue;
+            };
+
+            if !self.visited.insert(bcb) {
+                debug!("Already visited: {bcb:?}");
+                continue;
+            }
+            debug!("Visiting {bcb:?}");
+
+            if self.backedges[bcb].len() > 0 {
+                debug!("{bcb:?} is a loop header! Start a new TraversalContext...");
+                self.context_stack
+                    .push(TraversalContext { loop_header: Some(bcb), worklist: VecDeque::new() });
             }
+            self.add_successors_to_worklists(bcb);
+            return Some(bcb);
         }
 
         None
     }
 
-    pub fn add_successors_to_worklists(&mut self, bcb: BasicCoverageBlock) {
+    fn add_successors_to_worklists(&mut self, bcb: BasicCoverageBlock) {
         let successors = &self.basic_coverage_blocks.successors[bcb];
         debug!("{:?} has {} successors:", bcb, successors.len());
 
@@ -494,11 +497,11 @@ impl<'a> TraverseCoverageGraphWithLoops<'a> {
         }
     }
 
-    pub fn is_complete(&self) -> bool {
+    pub(crate) fn is_complete(&self) -> bool {
         self.visited.count() == self.visited.domain_size()
     }
 
-    pub fn unvisited(&self) -> Vec<BasicCoverageBlock> {
+    pub(crate) fn unvisited(&self) -> Vec<BasicCoverageBlock> {
         let mut unvisited_set: BitSet<BasicCoverageBlock> =
             BitSet::new_filled(self.visited.domain_size());
         unvisited_set.subtract(&self.visited);
@@ -506,7 +509,7 @@ impl<'a> TraverseCoverageGraphWithLoops<'a> {
     }
 }
 
-pub(super) fn find_loop_backedges(
+fn find_loop_backedges(
     basic_coverage_blocks: &CoverageGraph,
 ) -> IndexVec<BasicCoverageBlock, Vec<BasicCoverageBlock>> {
     let num_bcbs = basic_coverage_blocks.num_nodes();