Auto merge of rust-lang#139054 - matthiaskrgr:rollup-2bk2fb4, r=matthiaskrgr

Rollup of 7 pull requests

Successful merges:

 - rust-lang#137889 (update outdated doc with new example)
 - rust-lang#138104 (Greatly simplify doctest parsing and information extraction)
 - rust-lang#138678 (rustc_resolve: fix instability in lib.rmeta contents)
 - rust-lang#138986 (feat(config): Add ChangeId enum for suppressing warnings)
 - rust-lang#139038 (Update target maintainers for thumb targets to reflect new REWG Arm team name)
 - rust-lang#139045 (bootstrap: update `test_find` test)
 - rust-lang#139047 (Remove ScopeDepth)

Failed merges:

 - rust-lang#139044 (bootstrap: Avoid cloning `change-id` list)

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

Author: bors

Diff for: Cargo.lock

@@ -4300,6 +4300,7 @@ name = "rustc_resolve"
 version = "0.0.0"
 dependencies = [
  "bitflags",
+ "itertools",
  "pulldown-cmark 0.11.3",
  "rustc_arena",
  "rustc_ast",

Diff for: bootstrap.example.toml

@@ -28,8 +28,9 @@
 #  - A new option
 #  - A change in the default values
 #
-# If `change-id` does not match the version that is currently running,
-# `x.py` will inform you about the changes made on bootstrap.
+# If the change-id does not match the version currently in use, x.py will 
+# display the changes made to the bootstrap.
+# To suppress these warnings, you can set change-id = "ignore".
 #change-id = <latest change id in src/bootstrap/src/utils/change_tracker.rs>
 
 # =============================================================================

Diff for: compiler/rustc_hir_analysis/src/check/region.rs

@@ -23,18 +23,11 @@ use tracing::debug;
 
 #[derive(Debug, Copy, Clone)]
 struct Context {
-    /// The scope that contains any new variables declared, plus its depth in
-    /// the scope tree.
+    /// The scope that contains any new variables declared.
     var_parent: Option<Scope>,
 
-    /// Region parent of expressions, etc., plus its depth in the scope tree.
-    parent: Option<(Scope, ScopeDepth)>,
-}
-
-impl Context {
-    fn set_var_parent(&mut self) {
-        self.var_parent = self.parent.map(|(p, _)| p);
-    }
+    /// Region parent of expressions, etc.
+    parent: Option<Scope>,
 }
 
 struct ScopeResolutionVisitor<'tcx> {
@@ -119,7 +112,7 @@ fn resolve_block<'tcx>(visitor: &mut ScopeResolutionVisitor<'tcx>, blk: &'tcx hi
     // itself has returned.
 
     visitor.enter_node_scope_with_dtor(blk.hir_id.local_id);
-    visitor.cx.set_var_parent();
+    visitor.cx.var_parent = visitor.cx.parent;
 
     {
         // This block should be kept approximately in sync with
@@ -138,7 +131,7 @@ fn resolve_block<'tcx>(visitor: &mut ScopeResolutionVisitor<'tcx>, blk: &'tcx hi
                         local_id: blk.hir_id.local_id,
                         data: ScopeData::Remainder(FirstStatementIndex::new(i)),
                     });
-                    visitor.cx.set_var_parent();
+                    visitor.cx.var_parent = visitor.cx.parent;
                     visitor.visit_stmt(statement);
                     // We need to back out temporarily to the last enclosing scope
                     // for the `else` block, so that even the temporaries receiving
@@ -163,7 +156,7 @@ fn resolve_block<'tcx>(visitor: &mut ScopeResolutionVisitor<'tcx>, blk: &'tcx hi
                         local_id: blk.hir_id.local_id,
                         data: ScopeData::Remainder(FirstStatementIndex::new(i)),
                     });
-                    visitor.cx.set_var_parent();
+                    visitor.cx.var_parent = visitor.cx.parent;
                     visitor.visit_stmt(statement)
                 }
                 hir::StmtKind::Item(..) => {
@@ -213,7 +206,7 @@ fn resolve_arm<'tcx>(visitor: &mut ScopeResolutionVisitor<'tcx>, arm: &'tcx hir:
     visitor.terminating_scopes.insert(arm.hir_id.local_id);
 
     visitor.enter_node_scope_with_dtor(arm.hir_id.local_id);
-    visitor.cx.set_var_parent();
+    visitor.cx.var_parent = visitor.cx.parent;
 
     if let Some(expr) = arm.guard
         && !has_let_expr(expr)
@@ -490,7 +483,7 @@ fn resolve_expr<'tcx>(visitor: &mut ScopeResolutionVisitor<'tcx>, expr: &'tcx hi
                 ScopeData::IfThen
             };
             visitor.enter_scope(Scope { local_id: then.hir_id.local_id, data });
-            visitor.cx.set_var_parent();
+            visitor.cx.var_parent = visitor.cx.parent;
             visitor.visit_expr(cond);
             visitor.visit_expr(then);
             visitor.cx = expr_cx;
@@ -505,7 +498,7 @@ fn resolve_expr<'tcx>(visitor: &mut ScopeResolutionVisitor<'tcx>, expr: &'tcx hi
                 ScopeData::IfThen
             };
             visitor.enter_scope(Scope { local_id: then.hir_id.local_id, data });
-            visitor.cx.set_var_parent();
+            visitor.cx.var_parent = visitor.cx.parent;
             visitor.visit_expr(cond);
             visitor.visit_expr(then);
             visitor.cx = expr_cx;
@@ -545,7 +538,7 @@ fn resolve_expr<'tcx>(visitor: &mut ScopeResolutionVisitor<'tcx>, expr: &'tcx hi
             // Keep traversing up while we can.
             match visitor.scope_tree.parent_map.get(&scope) {
                 // Don't cross from closure bodies to their parent.
-                Some(&(superscope, _)) => match superscope.data {
+                Some(&superscope) => match superscope.data {
                     ScopeData::CallSite => break,
                     _ => scope = superscope,
                 },
@@ -781,20 +774,16 @@ fn resolve_local<'tcx>(
 
 impl<'tcx> ScopeResolutionVisitor<'tcx> {
     /// Records the current parent (if any) as the parent of `child_scope`.
-    /// Returns the depth of `child_scope`.
-    fn record_child_scope(&mut self, child_scope: Scope) -> ScopeDepth {
+    fn record_child_scope(&mut self, child_scope: Scope) {
         let parent = self.cx.parent;
         self.scope_tree.record_scope_parent(child_scope, parent);
-        // If `child_scope` has no parent, it must be the root node, and so has
-        // a depth of 1. Otherwise, its depth is one more than its parent's.
-        parent.map_or(1, |(_p, d)| d + 1)
     }
 
     /// Records the current parent (if any) as the parent of `child_scope`,
     /// and sets `child_scope` as the new current parent.
     fn enter_scope(&mut self, child_scope: Scope) {
-        let child_depth = self.record_child_scope(child_scope);
-        self.cx.parent = Some((child_scope, child_depth));
+        self.record_child_scope(child_scope);
+        self.cx.parent = Some(child_scope);
     }
 
     fn enter_node_scope_with_dtor(&mut self, id: hir::ItemLocalId) {
@@ -855,7 +844,7 @@ impl<'tcx> Visitor<'tcx> for ScopeResolutionVisitor<'tcx> {
         self.enter_body(body.value.hir_id, |this| {
             if this.tcx.hir_body_owner_kind(owner_id).is_fn_or_closure() {
                 // The arguments and `self` are parented to the fn.
-                this.cx.set_var_parent();
+                this.cx.var_parent = this.cx.parent;
                 for param in body.params {
                     this.visit_pat(param.pat);
                 }

Diff for: compiler/rustc_hir_analysis/src/check/wfcheck.rs

@@ -188,10 +188,10 @@ fn check_well_formed(tcx: TyCtxt<'_>, def_id: LocalDefId) -> Result<(), ErrorGua
 /// definition itself. For example, this definition would be illegal:
 ///
 /// ```rust
-/// struct Ref<'a, T> { x: &'a T }
+/// struct StaticRef<T> { x: &'static T }
 /// ```
 ///
-/// because the type did not declare that `T:'a`.
+/// because the type did not declare that `T: 'static`.
 ///
 /// We do this check as a pre-pass before checking fn bodies because if these constraints are
 /// not included it frequently leads to confusing errors in fn bodies. So it's better to check

Diff for: compiler/rustc_middle/src/middle/region.rs

@@ -199,8 +199,6 @@ impl Scope {
     }
 }
 
-pub type ScopeDepth = u32;
-
 /// The region scope tree encodes information about region relationships.
 #[derive(Default, Debug, HashStable)]
 pub struct ScopeTree {
@@ -213,7 +211,7 @@ pub struct ScopeTree {
     /// conditional expression or repeating block. (Note that the
     /// enclosing scope ID for the block associated with a closure is
     /// the closure itself.)
-    pub parent_map: FxIndexMap<Scope, (Scope, ScopeDepth)>,
+    pub parent_map: FxIndexMap<Scope, Scope>,
 
     /// Maps from a variable or binding ID to the block in which that
     /// variable is declared.
@@ -328,7 +326,7 @@ pub struct YieldData {
 }
 
 impl ScopeTree {
-    pub fn record_scope_parent(&mut self, child: Scope, parent: Option<(Scope, ScopeDepth)>) {
+    pub fn record_scope_parent(&mut self, child: Scope, parent: Option<Scope>) {
         debug!("{:?}.parent = {:?}", child, parent);
 
         if let Some(p) = parent {
@@ -353,7 +351,7 @@ impl ScopeTree {
 
     /// Returns the narrowest scope that encloses `id`, if any.
     pub fn opt_encl_scope(&self, id: Scope) -> Option<Scope> {
-        self.parent_map.get(&id).cloned().map(|(p, _)| p)
+        self.parent_map.get(&id).cloned()
     }
 
     /// Returns the lifetime of the local variable `var_id`, if any.

Diff for: compiler/rustc_middle/src/ty/rvalue_scopes.rs

@@ -38,7 +38,7 @@ impl RvalueScopes {
         let mut id = Scope { local_id: expr_id, data: ScopeData::Node };
         let mut backwards_incompatible = None;
 
-        while let Some(&(p, _)) = region_scope_tree.parent_map.get(&id) {
+        while let Some(&p) = region_scope_tree.parent_map.get(&id) {
             match p.data {
                 ScopeData::Destruction => {
                     debug!("temporary_scope({expr_id:?}) = {id:?} [enclosing]");

Diff for: compiler/rustc_resolve/Cargo.toml

@@ -6,6 +6,7 @@ edition = "2024"
 [dependencies]
 # tidy-alphabetical-start
 bitflags = "2.4.1"
+itertools = "0.12"
 pulldown-cmark = { version = "0.11", features = ["html"], default-features = false }
 rustc_arena = { path = "../rustc_arena" }
 rustc_ast = { path = "../rustc_ast" }

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

@@ -1,13 +1,15 @@
 use std::mem;
 use std::ops::Range;
 
+use itertools::Itertools;
 use pulldown_cmark::{
     BrokenLink, BrokenLinkCallback, CowStr, Event, LinkType, Options, Parser, Tag,
 };
 use rustc_ast as ast;
 use rustc_ast::attr::AttributeExt;
 use rustc_ast::util::comments::beautify_doc_string;
-use rustc_data_structures::fx::{FxHashSet, FxIndexMap};
+use rustc_data_structures::fx::FxIndexMap;
+use rustc_data_structures::unord::UnordSet;
 use rustc_middle::ty::TyCtxt;
 use rustc_span::def_id::DefId;
 use rustc_span::{DUMMY_SP, InnerSpan, Span, Symbol, kw, sym};
@@ -422,7 +424,7 @@ fn parse_links<'md>(doc: &'md str) -> Vec<Box<str>> {
     );
     let mut links = Vec::new();
 
-    let mut refids = FxHashSet::default();
+    let mut refids = UnordSet::default();
 
     while let Some(event) = event_iter.next() {
         match event {
@@ -454,7 +456,7 @@ fn parse_links<'md>(doc: &'md str) -> Vec<Box<str>> {
         }
     }
 
-    for (label, refdef) in event_iter.reference_definitions().iter() {
+    for (label, refdef) in event_iter.reference_definitions().iter().sorted_by_key(|x| x.0) {
         if !refids.contains(label) {
             links.push(preprocess_link(&refdef.dest));
         }

Diff for: src/bootstrap/src/bin/main.rs

@@ -11,8 +11,8 @@ use std::str::FromStr;
 use std::{env, process};
 
 use bootstrap::{
-    Build, CONFIG_CHANGE_HISTORY, Config, Flags, Subcommand, debug, find_recent_config_change_ids,
-    human_readable_changes, t,
+    Build, CONFIG_CHANGE_HISTORY, ChangeId, Config, Flags, Subcommand, debug,
+    find_recent_config_change_ids, human_readable_changes, t,
 };
 #[cfg(feature = "tracing")]
 use tracing::instrument;
@@ -155,50 +155,52 @@ fn check_version(config: &Config) -> Option<String> {
     let latest_change_id = CONFIG_CHANGE_HISTORY.last().unwrap().change_id;
     let warned_id_path = config.out.join("bootstrap").join(".last-warned-change-id");
 
-    if let Some(mut id) = config.change_id {
-        if id == latest_change_id {
-            return None;
+    let mut id = match config.change_id {
+        Some(ChangeId::Id(id)) if id == latest_change_id => return None,
+        Some(ChangeId::Ignore) => return None,
+        Some(ChangeId::Id(id)) => id,
+        None => {
+            msg.push_str("WARNING: The `change-id` is missing in the `bootstrap.toml`. This means that you will not be able to track the major changes made to the bootstrap configurations.\n");
+            msg.push_str("NOTE: to silence this warning, ");
+            msg.push_str(&format!(
+                "add `change-id = {latest_change_id}` or change-id = \"ignore\" at the top of `bootstrap.toml`"
+            ));
+            return Some(msg);
         }
+    };
 
-        // Always try to use `change-id` from .last-warned-change-id first. If it doesn't exist,
-        // then use the one from the bootstrap.toml. This way we never show the same warnings
-        // more than once.
-        if let Ok(t) = fs::read_to_string(&warned_id_path) {
-            let last_warned_id = usize::from_str(&t)
-                .unwrap_or_else(|_| panic!("{} is corrupted.", warned_id_path.display()));
-
-            // We only use the last_warned_id if it exists in `CONFIG_CHANGE_HISTORY`.
-            // Otherwise, we may retrieve all the changes if it's not the highest value.
-            // For better understanding, refer to `change_tracker::find_recent_config_change_ids`.
-            if CONFIG_CHANGE_HISTORY.iter().any(|config| config.change_id == last_warned_id) {
-                id = last_warned_id;
-            }
-        };
+    // Always try to use `change-id` from .last-warned-change-id first. If it doesn't exist,
+    // then use the one from the bootstrap.toml. This way we never show the same warnings
+    // more than once.
+    if let Ok(t) = fs::read_to_string(&warned_id_path) {
+        let last_warned_id = usize::from_str(&t)
+            .unwrap_or_else(|_| panic!("{} is corrupted.", warned_id_path.display()));
+
+        // We only use the last_warned_id if it exists in `CONFIG_CHANGE_HISTORY`.
+        // Otherwise, we may retrieve all the changes if it's not the highest value.
+        // For better understanding, refer to `change_tracker::find_recent_config_change_ids`.
+        if CONFIG_CHANGE_HISTORY.iter().any(|config| config.change_id == last_warned_id) {
+            id = last_warned_id;
+        }
+    };
 
-        let changes = find_recent_config_change_ids(id);
+    let changes = find_recent_config_change_ids(id);
 
-        if changes.is_empty() {
-            return None;
-        }
+    if changes.is_empty() {
+        return None;
+    }
 
-        msg.push_str("There have been changes to x.py since you last updated:\n");
-        msg.push_str(&human_readable_changes(&changes));
+    msg.push_str("There have been changes to x.py since you last updated:\n");
+    msg.push_str(&human_readable_changes(&changes));
 
-        msg.push_str("NOTE: to silence this warning, ");
-        msg.push_str(&format!(
-            "update `bootstrap.toml` to use `change-id = {latest_change_id}` instead"
-        ));
+    msg.push_str("NOTE: to silence this warning, ");
+    msg.push_str(&format!(
+        "update `bootstrap.toml` to use `change-id = {latest_change_id}` or change-id = \"ignore\" instead"
+    ));
 
-        if io::stdout().is_terminal() {
-            t!(fs::write(warned_id_path, latest_change_id.to_string()));
-        }
-    } else {
-        msg.push_str("WARNING: The `change-id` is missing in the `bootstrap.toml`. This means that you will not be able to track the major changes made to the bootstrap configurations.\n");
-        msg.push_str("NOTE: to silence this warning, ");
-        msg.push_str(&format!(
-            "add `change-id = {latest_change_id}` at the top of `bootstrap.toml`"
-        ));
-    };
+    if io::stdout().is_terminal() {
+        t!(fs::write(warned_id_path, latest_change_id.to_string()));
+    }
 
     Some(msg)
 }