Auto merge of #108934 - matthiaskrgr:rollup-vm414p5, r=matthiaskrgr

Rollup of 8 pull requests

Successful merges:

 - #106915 (Only load one CSS theme by default)
 - #108294 (Place binder correctly for arbitrary trait bound suggestion)
 - #108778 (x fmt: Don't print all modified files if there's more than 10)
 - #108854 (feat/refactor: improve errors in case of ident with number at start)
 - #108870 (Fix invalid inlining of reexport of reexport of private item)
 - #108917 (Consider target_family as pal)
 - #108922 (Add auto notification for changes to stable mir)
 - #108929 (Fix typo in span_map.rs)

Failed merges:

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

9 files changed, 198 insertions, 100 deletions

diff --git a/src/bootstrap/format.rs b/src/bootstrap/format.rs
index 5cb94c2f1d6..b79969663ca 100644
--- a/src/bootstrap/format.rs
+++ b/src/bootstrap/format.rs
@@ -165,8 +165,14 @@ pub fn format(build: &Builder<'_>, check: bool, paths: &[PathBuf]) {
             if !CiEnv::is_ci() && paths.is_empty() {
                 match get_modified_rs_files(build) {
                     Ok(Some(files)) => {
+                        if files.len() <= 10 {
+                            for file in &files {
+                                println!("formatting modified file {file}");
+                            }
+                        } else {
+                            println!("formatting {} modified files", files.len());
+                        }
                         for file in files {
-                            println!("formatting modified file {file}");
                             ignore_fmt.add(&format!("/{file}")).expect(&file);
                         }
                     }
diff --git a/src/librustdoc/clean/mod.rs b/src/librustdoc/clean/mod.rs
index bbd9f18973a..29c3afe0d95 100644
--- a/src/librustdoc/clean/mod.rs
+++ b/src/librustdoc/clean/mod.rs
@@ -2065,23 +2065,81 @@ fn clean_bare_fn_ty<'tcx>(
     BareFunctionDecl { unsafety: bare_fn.unsafety, abi: bare_fn.abi, decl, generic_params }
 }
 
-/// This visitor is used to go through only the "top level" of a item and not enter any sub
-/// item while looking for a given `Ident` which is stored into `item` if found.
-struct OneLevelVisitor<'hir> {
+/// Get DefId of of an item's user-visible parent.
+///
+/// "User-visible" should account for re-exporting and inlining, which is why this function isn't
+/// just `tcx.parent(def_id)`. If the provided `path` has more than one path element, the `DefId`
+/// of the second-to-last will be given.
+///
+/// ```text
+/// use crate::foo::Bar;
+///            ^^^ DefId of this item will be returned
+/// ```
+///
+/// If the provided path has only one item, `tcx.parent(def_id)` will be returned instead.
+fn get_path_parent_def_id(
+    tcx: TyCtxt<'_>,
+    def_id: DefId,
+    path: &hir::UsePath<'_>,
+) -> Option<DefId> {
+    if let [.., parent_segment, _] = &path.segments {
+        match parent_segment.res {
+            hir::def::Res::Def(_, parent_def_id) => Some(parent_def_id),
+            _ if parent_segment.ident.name == kw::Crate => {
+                // In case the "parent" is the crate, it'll give `Res::Err` so we need to
+                // circumvent it this way.
+                Some(tcx.parent(def_id))
+            }
+            _ => None,
+        }
+    } else {
+        // If the path doesn't have a parent, then the parent is the current module.
+        Some(tcx.parent(def_id))
+    }
+}
+
+/// This visitor is used to find an HIR Item based on its `use` path. This doesn't use the ordinary
+/// name resolver because it does not walk all the way through a chain of re-exports.
+pub(crate) struct OneLevelVisitor<'hir> {
     map: rustc_middle::hir::map::Map<'hir>,
-    item: Option<&'hir hir::Item<'hir>>,
+    pub(crate) item: Option<&'hir hir::Item<'hir>>,
     looking_for: Ident,
     target_def_id: LocalDefId,
 }
 
 impl<'hir> OneLevelVisitor<'hir> {
-    fn new(map: rustc_middle::hir::map::Map<'hir>, target_def_id: LocalDefId) -> Self {
+    pub(crate) fn new(map: rustc_middle::hir::map::Map<'hir>, target_def_id: LocalDefId) -> Self {
         Self { map, item: None, looking_for: Ident::empty(), target_def_id }
     }
 
-    fn reset(&mut self, looking_for: Ident) {
-        self.looking_for = looking_for;
+    pub(crate) fn find_target(
+        &mut self,
+        tcx: TyCtxt<'_>,
+        def_id: DefId,
+        path: &hir::UsePath<'_>,
+    ) -> Option<&'hir hir::Item<'hir>> {
+        let parent_def_id = get_path_parent_def_id(tcx, def_id, path)?;
+        let parent = self.map.get_if_local(parent_def_id)?;
+
+        // We get the `Ident` we will be looking for into `item`.
+        self.looking_for = path.segments[path.segments.len() - 1].ident;
+        // We reset the `item`.
         self.item = None;
+
+        match parent {
+            hir::Node::Item(parent_item) => {
+                hir::intravisit::walk_item(self, parent_item);
+            }
+            hir::Node::Crate(m) => {
+                hir::intravisit::walk_mod(
+                    self,
+                    m,
+                    tcx.local_def_id_to_hir_id(parent_def_id.as_local().unwrap()),
+                );
+            }
+            _ => return None,
+        }
+        self.item
     }
 }
 
@@ -2129,41 +2187,7 @@ fn get_all_import_attributes<'hir>(
             add_without_unwanted_attributes(attributes, hir_map.attrs(item.hir_id()), is_inline);
         }
 
-        let def_id = if let [.., parent_segment, _] = &path.segments {
-            match parent_segment.res {
-                hir::def::Res::Def(_, def_id) => def_id,
-                _ if parent_segment.ident.name == kw::Crate => {
-                    // In case the "parent" is the crate, it'll give `Res::Err` so we need to
-                    // circumvent it this way.
-                    tcx.parent(item.owner_id.def_id.to_def_id())
-                }
-                _ => break,
-            }
-        } else {
-            // If the path doesn't have a parent, then the parent is the current module.
-            tcx.parent(item.owner_id.def_id.to_def_id())
-        };
-
-        let Some(parent) = hir_map.get_if_local(def_id) else { break };
-
-        // We get the `Ident` we will be looking for into `item`.
-        let looking_for = path.segments[path.segments.len() - 1].ident;
-        visitor.reset(looking_for);
-
-        match parent {
-            hir::Node::Item(parent_item) => {
-                hir::intravisit::walk_item(&mut visitor, parent_item);
-            }
-            hir::Node::Crate(m) => {
-                hir::intravisit::walk_mod(
-                    &mut visitor,
-                    m,
-                    tcx.local_def_id_to_hir_id(def_id.as_local().unwrap()),
-                );
-            }
-            _ => break,
-        }
-        if let Some(i) = visitor.item {
+        if let Some(i) = visitor.find_target(tcx, item.owner_id.def_id.to_def_id(), path) {
             item = i;
         } else {
             break;
diff --git a/src/librustdoc/html/render/context.rs b/src/librustdoc/html/render/context.rs
index 1030fe74747..ed1eb66b97c 100644
--- a/src/librustdoc/html/render/context.rs
+++ b/src/librustdoc/html/render/context.rs
@@ -647,11 +647,35 @@ impl<'tcx> FormatRenderer<'tcx> for Context<'tcx> {
                      </noscript>\
                      <link rel=\"stylesheet\" \
                          href=\"{static_root_path}{settings_css}\">\
-                     <script defer src=\"{static_root_path}{settings_js}\"></script>",
+                     <script defer src=\"{static_root_path}{settings_js}\"></script>\
+                     <link rel=\"preload\" href=\"{static_root_path}{theme_light_css}\" \
+                         as=\"style\">\
+                     <link rel=\"preload\" href=\"{static_root_path}{theme_dark_css}\" \
+                         as=\"style\">\
+                     <link rel=\"preload\" href=\"{static_root_path}{theme_ayu_css}\" \
+                         as=\"style\">",
                     static_root_path = page.get_static_root_path(),
                     settings_css = static_files::STATIC_FILES.settings_css,
                     settings_js = static_files::STATIC_FILES.settings_js,
-                )
+                    theme_light_css = static_files::STATIC_FILES.theme_light_css,
+                    theme_dark_css = static_files::STATIC_FILES.theme_dark_css,
+                    theme_ayu_css = static_files::STATIC_FILES.theme_ayu_css,
+                );
+                // Pre-load all theme CSS files, so that switching feels seamless.
+                //
+                // When loading settings.html as a popover, the equivalent HTML is
+                // generated in main.js.
+                for file in &shared.style_files {
+                    if let Ok(theme) = file.basename() {
+                        write!(
+                            buf,
+                            "<link rel=\"preload\" href=\"{root_path}{theme}{suffix}.css\" \
+                                as=\"style\">",
+                            root_path = page.static_root_path.unwrap_or(""),
+                            suffix = page.resource_suffix,
+                        );
+                    }
+                }
             },
             &shared.style_files,
         );
diff --git a/src/librustdoc/html/render/span_map.rs b/src/librustdoc/html/render/span_map.rs
index 4514894cabe..eb9262f472b 100644
--- a/src/librustdoc/html/render/span_map.rs
+++ b/src/librustdoc/html/render/span_map.rs
@@ -29,12 +29,12 @@ pub(crate) enum LinkFromSrc {
 
 /// This function will do at most two things:
 ///
-/// 1. Generate a `span` correspondance map which links an item `span` to its definition `span`.
+/// 1. Generate a `span` correspondence map which links an item `span` to its definition `span`.
 /// 2. Collect the source code files.
 ///
-/// It returns the `krate`, the source code files and the `span` correspondance map.
+/// It returns the `krate`, the source code files and the `span` correspondence map.
 ///
-/// Note about the `span` correspondance map: the keys are actually `(lo, hi)` of `span`s. We don't
+/// Note about the `span` correspondence map: the keys are actually `(lo, hi)` of `span`s. We don't
 /// need the `span` context later on, only their position, so instead of keep a whole `Span`, we
 /// only keep the `lo` and `hi`.
 pub(crate) fn collect_spans_and_sources(
diff --git a/src/librustdoc/html/static/js/main.js b/src/librustdoc/html/static/js/main.js
index 5e8c0e8d10c..403b5004d65 100644
--- a/src/librustdoc/html/static/js/main.js
+++ b/src/librustdoc/html/static/js/main.js
@@ -1,20 +1,9 @@
 // Local js definitions:
 /* global addClass, getSettingValue, hasClass, searchState */
-/* global onEach, onEachLazy, removeClass */
+/* global onEach, onEachLazy, removeClass, getVar */
 
 "use strict";
 
-// Get a value from the rustdoc-vars div, which is used to convey data from
-// Rust to the JS. If there is no such element, return null.
-function getVar(name) {
-    const el = document.getElementById("rustdoc-vars");
-    if (el) {
-        return el.attributes["data-" + name].value;
-    } else {
-        return null;
-    }
-}
-
 // Given a basename (e.g. "storage") and an extension (e.g. ".js"), return a URL
 // for a resource under the root-path, with the resource-suffix.
 function resourcePath(basename, extension) {
@@ -187,6 +176,15 @@ function loadCss(cssUrl) {
     document.getElementsByTagName("head")[0].appendChild(link);
 }
 
+function preLoadCss(cssUrl) {
+    // https://developer.mozilla.org/en-US/docs/Web/HTML/Link_types/preload
+    const link = document.createElement("link");
+    link.href = cssUrl;
+    link.rel = "preload";
+    link.as = "style";
+    document.getElementsByTagName("head")[0].appendChild(link);
+}
+
 (function() {
     const isHelpPage = window.location.pathname.endsWith("/help.html");
 
@@ -207,6 +205,23 @@ function loadCss(cssUrl) {
         // hopefully be loaded when the JS will generate the settings content.
         loadCss(getVar("static-root-path") + getVar("settings-css"));
         loadScript(getVar("static-root-path") + getVar("settings-js"));
+        preLoadCss(getVar("static-root-path") + getVar("theme-light-css"));
+        preLoadCss(getVar("static-root-path") + getVar("theme-dark-css"));
+        preLoadCss(getVar("static-root-path") + getVar("theme-ayu-css"));
+        // Pre-load all theme CSS files, so that switching feels seamless.
+        //
+        // When loading settings.html as a standalone page, the equivalent HTML is
+        // generated in context.rs.
+        setTimeout(() => {
+            const themes = getVar("themes").split(",");
+            for (const theme of themes) {
+                // if there are no themes, do nothing
+                // "".split(",") == [""]
+                if (theme !== "") {
+                    preLoadCss(getVar("root-path") + theme + ".css");
+                }
+            }
+        }, 0);
     };
 
     window.searchState = {
diff --git a/src/librustdoc/html/static/js/storage.js b/src/librustdoc/html/static/js/storage.js
index c72ac254fc0..c3fed9a72d4 100644
--- a/src/librustdoc/html/static/js/storage.js
+++ b/src/librustdoc/html/static/js/storage.js
@@ -7,7 +7,6 @@
 
 const darkThemes = ["dark", "ayu"];
 window.currentTheme = document.getElementById("themeStyle");
-window.mainTheme = document.getElementById("mainThemeStyle");
 
 // WARNING: RUSTDOC_MOBILE_BREAKPOINT MEDIA QUERY
 // If you update this line, then you also need to update the media query with the same
@@ -44,8 +43,6 @@ function getSettingValue(settingName) {
 
 const localStoredTheme = getSettingValue("theme");
 
-const savedHref = [];
-
 // eslint-disable-next-line no-unused-vars
 function hasClass(elem, className) {
     return elem && elem.classList && elem.classList.contains(className);
@@ -102,6 +99,7 @@ function onEach(arr, func, reversed) {
  * @param {function(?)}                   func       - The callback
  * @param {boolean}                       [reversed] - Whether to iterate in reverse
  */
+// eslint-disable-next-line no-unused-vars
 function onEachLazy(lazyArray, func, reversed) {
     return onEach(
         Array.prototype.slice.call(lazyArray),
@@ -125,30 +123,37 @@ function getCurrentValue(name) {
     }
 }
 
-function switchTheme(styleElem, mainStyleElem, newThemeName, saveTheme) {
+// Get a value from the rustdoc-vars div, which is used to convey data from
+// Rust to the JS. If there is no such element, return null.
+const getVar = (function getVar(name) {
+    const el = document.getElementById("rustdoc-vars");
+    if (el) {
+        return el.attributes["data-" + name].value;
+    } else {
+        return null;
+    }
+});
+
+function switchTheme(newThemeName, saveTheme) {
     // If this new value comes from a system setting or from the previously
     // saved theme, no need to save it.
     if (saveTheme) {
         updateLocalStorage("theme", newThemeName);
     }
 
-    if (savedHref.length === 0) {
-        onEachLazy(document.getElementsByTagName("link"), el => {
-            savedHref.push(el.href);
-        });
+    let newHref;
+
+    if (newThemeName === "light" || newThemeName === "dark" || newThemeName === "ayu") {
+        newHref = getVar("static-root-path") + getVar("theme-" + newThemeName + "-css");
+    } else {
+        newHref = getVar("root-path") + newThemeName + getVar("resource-suffix") + ".css";
     }
-    const newHref = savedHref.find(url => {
-        const m = url.match(/static\.files\/(.*)-[a-f0-9]{16}\.css$/);
-        if (m && m[1] === newThemeName) {
-            return true;
-        }
-        const m2 = url.match(/\/([^/]*)\.css$/);
-        if (m2 && m2[1].startsWith(newThemeName)) {
-            return true;
-        }
-    });
-    if (newHref && newHref !== styleElem.href) {
-        styleElem.href = newHref;
+
+    if (!window.currentTheme) {
+        document.write(`<link rel="stylesheet" id="themeStyle" href="${newHref}">`);
+        window.currentTheme = document.getElementById("themeStyle");
+    } else if (newHref !== window.currentTheme.href) {
+        window.currentTheme.href = newHref;
     }
 }
 
@@ -164,7 +169,7 @@ const updateTheme = (function() {
      */
     function updateTheme() {
         const use = (theme, saveTheme) => {
-            switchTheme(window.currentTheme, window.mainTheme, theme, saveTheme);
+            switchTheme(theme, saveTheme);
         };
 
         // maybe the user has disabled the setting in the meantime!
diff --git a/src/librustdoc/html/templates/page.html b/src/librustdoc/html/templates/page.html
index e896850fab6..532660e3d33 100644
--- a/src/librustdoc/html/templates/page.html
+++ b/src/librustdoc/html/templates/page.html
@@ -17,12 +17,6 @@
     <link rel="stylesheet" {#+ #}
           href="{{static_root_path|safe}}{{files.rustdoc_css}}" {#+ #}
           id="mainThemeStyle"> {# #}
-    <link rel="stylesheet" id="themeStyle" href="{{static_root_path|safe}}{{files.theme_light_css}}"> {# #}
-    <link rel="stylesheet" disabled href="{{static_root_path|safe}}{{files.theme_dark_css}}"> {# #}
-    <link rel="stylesheet" disabled href="{{static_root_path|safe}}{{files.theme_ayu_css}}"> {# #}
-    {% for theme in themes %}
-        <link rel="stylesheet" disabled href="{{page.root_path|safe}}{{theme}}{{page.resource_suffix}}.css"> {# #}
-    {% endfor %}
     {% if !layout.default_settings.is_empty() %}
     <script id="default-settings" {#+ #}
       {%~ for (k, v) in layout.default_settings ~%}
@@ -30,6 +24,21 @@
       {% endfor %}
     ></script> {# #}
     {% endif %}
+    <div id="rustdoc-vars" {#+ #}
+         data-root-path="{{page.root_path|safe}}" {#+ #}
+         data-static-root-path="{{static_root_path|safe}}" {#+ #}
+         data-current-crate="{{layout.krate}}" {#+ #}
+         data-themes="{{themes|join(",") }}" {#+ #}
+         data-resource-suffix="{{page.resource_suffix}}" {#+ #}
+         data-rustdoc-version="{{rustdoc_version}}" {#+ #}
+         data-search-js="{{files.search_js}}" {#+ #}
+         data-settings-js="{{files.settings_js}}" {#+ #}
+         data-settings-css="{{files.settings_css}}" {#+ #}
+         data-theme-light-css="{{files.theme_light_css}}" {#+ #}
+         data-theme-dark-css="{{files.theme_dark_css}}" {#+ #}
+         data-theme-ayu-css="{{files.theme_ayu_css}}" {#+ #}
+    > {# #}
+    </div> {# #}
     <script src="{{static_root_path|safe}}{{files.storage_js}}"></script> {# #}
     {% if page.css_class.contains("crate") %}
     <script defer src="{{page.root_path|safe}}crates{{page.resource_suffix}}.js"></script> {# #}
@@ -45,6 +54,12 @@
     {% endif %}
     <noscript> {# #}
         <link rel="stylesheet" {#+ #}
+           media="(prefers-color-scheme:light)" {#+ #}
+           href="{{static_root_path|safe}}{{files.theme_light_css}}"> {# #}
+        <link rel="stylesheet" {#+ #}
+           media="(prefers-color-scheme:dark)" {#+ #}
+           href="{{static_root_path|safe}}{{files.theme_dark_css}}"> {# #}
+        <link rel="stylesheet" {#+ #}
            href="{{static_root_path|safe}}{{files.noscript_css}}"> {# #}
     </noscript> {# #}
     {% if layout.css_file_extension.is_some() %}
@@ -132,17 +147,5 @@
         {% if page.css_class != "source" %}</div>{% endif %}
     </main> {# #}
     {{ layout.external_html.after_content|safe }}
-    <div id="rustdoc-vars" {#+ #}
-         data-root-path="{{page.root_path|safe}}" {#+ #}
-         data-static-root-path="{{static_root_path|safe}}" {#+ #}
-         data-current-crate="{{layout.krate}}" {#+ #}
-         data-themes="{{themes|join(",") }}" {#+ #}
-         data-resource-suffix="{{page.resource_suffix}}" {#+ #}
-         data-rustdoc-version="{{rustdoc_version}}" {#+ #}
-         data-search-js="{{files.search_js}}" {#+ #}
-         data-settings-js="{{files.settings_js}}" {#+ #}
-         data-settings-css="{{files.settings_css}}" {#+ #}
-    > {# #}
-    </div> {# #}
 </body> {# #}
 </html> {# #}
diff --git a/src/librustdoc/visit_ast.rs b/src/librustdoc/visit_ast.rs
index 5bbbff175cf..44e9b49f82a 100644
--- a/src/librustdoc/visit_ast.rs
+++ b/src/librustdoc/visit_ast.rs
@@ -15,7 +15,7 @@ use rustc_span::Span;
 
 use std::mem;
 
-use crate::clean::{cfg::Cfg, AttributesExt, NestedAttributesExt};
+use crate::clean::{cfg::Cfg, AttributesExt, NestedAttributesExt, OneLevelVisitor};
 use crate::core;
 
 /// This module is used to store stuff from Rust's AST in a more convenient
@@ -220,6 +220,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
         renamed: Option<Symbol>,
         glob: bool,
         please_inline: bool,
+        path: &hir::UsePath<'_>,
     ) -> bool {
         debug!("maybe_inline_local res: {:?}", res);
 
@@ -263,6 +264,22 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
             return false;
         }
 
+        if !please_inline &&
+            let mut visitor = OneLevelVisitor::new(self.cx.tcx.hir(), res_did) &&
+            let Some(item) = visitor.find_target(self.cx.tcx, def_id.to_def_id(), path) &&
+            let item_def_id = item.owner_id.def_id &&
+            item_def_id != def_id &&
+            self
+                .cx
+                .cache
+                .effective_visibilities
+                .is_directly_public(self.cx.tcx, item_def_id.to_def_id()) &&
+            !inherits_doc_hidden(self.cx.tcx, item_def_id)
+        {
+            // The imported item is public and not `doc(hidden)` so no need to inline it.
+            return false;
+        }
+
         let ret = match tcx.hir().get_by_def_id(res_did) {
             Node::Item(&hir::Item { kind: hir::ItemKind::Mod(ref m), .. }) if glob => {
                 let prev = mem::replace(&mut self.inlining, true);
@@ -361,6 +378,7 @@ impl<'a, 'tcx> RustdocVisitor<'a, 'tcx> {
                             ident,
                             is_glob,
                             please_inline,
+                            path,
                         ) {
                             continue;
                         }
diff --git a/src/tools/tidy/src/pal.rs b/src/tools/tidy/src/pal.rs
index 33938ac9a0a..6d6d3c89a3c 100644
--- a/src/tools/tidy/src/pal.rs
+++ b/src/tools/tidy/src/pal.rs
@@ -62,6 +62,8 @@ const EXCEPTION_PATHS: &[&str] = &[
     "library/std/src/panic.rs",   // fuchsia-specific panic backtrace handling
     "library/std/src/personality.rs",
     "library/std/src/personality/",
+    "library/std/src/thread/mod.rs",
+    "library/std/src/thread/local.rs",
 ];
 
 pub fn check(path: &Path, bad: &mut bool) {
@@ -128,6 +130,7 @@ fn check_cfgs(
             || cfg.contains("target_env")
             || cfg.contains("target_abi")
             || cfg.contains("target_vendor")
+            || cfg.contains("target_family")
             || cfg.contains("unix")
             || cfg.contains("windows");