Auto merge of rust-lang#130701 - GuillaumeGomez:rollup-kktsdsv, r=GuillaumeGomez

Rollup of 5 pull requests

Successful merges:

 - rust-lang#129545 (rustdoc: redesign toolbar and disclosure widgets)
 - rust-lang#130658 (Fix docs of compare_bytes)
 - rust-lang#130670 (delay uncapping the max_read_size in File::read_to_end)
 - rust-lang#130690 (interpret: remove outdated FIXME)
 - rust-lang#130692 (make unstable Result::flatten a const fn)

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

Author: bors

compiler/rustc_const_eval/src/interpret/call.rs

@@ -221,7 +221,6 @@ impl<'tcx, M: Machine<'tcx>> InterpCx<'tcx, M> {
         }
 
         // Fall back to exact equality.
-        // FIXME: We are missing the rules for "repr(C) wrapping compatible types".
         Ok(caller == callee)
     }
 

library/core/src/intrinsics.rs

@@ -2733,7 +2733,7 @@ extern "rust-intrinsic" {
 
     /// Lexicographically compare `[left, left + bytes)` and `[right, right + bytes)`
     /// as unsigned bytes, returning negative if `left` is less, zero if all the
-    /// bytes match, or positive if `right` is greater.
+    /// bytes match, or positive if `left` is greater.
     ///
     /// This underlies things like `<[u8]>::cmp`, and will usually lower to `memcmp`.
     ///

library/core/src/option.rs

@@ -2538,6 +2538,7 @@ impl<T> Option<Option<T>> {
     #[stable(feature = "option_flattening", since = "1.40.0")]
     #[rustc_const_unstable(feature = "const_option", issue = "67441")]
     pub const fn flatten(self) -> Option<T> {
+        // FIXME(const-hack): could be written with `and_then`
         match self {
             Some(inner) => inner,
             None => None,

library/core/src/result.rs

@@ -1676,8 +1676,13 @@ impl<T, E> Result<Result<T, E>, E> {
     /// ```
     #[inline]
     #[unstable(feature = "result_flattening", issue = "70142")]
-    pub fn flatten(self) -> Result<T, E> {
-        self.and_then(convert::identity)
+    #[rustc_const_unstable(feature = "result_flattening", issue = "70142")]
+    pub const fn flatten(self) -> Result<T, E> {
+        // FIXME(const-hack): could be written with `and_then`
+        match self {
+            Ok(inner) => inner,
+            Err(e) => Err(e),
+        }
     }
 }
 

library/std/src/io/mod.rs

@@ -398,8 +398,7 @@ where
 // - avoid passing large buffers to readers that always initialize the free capacity if they perform short reads (#23815, #23820)
 // - pass large buffers to readers that do not initialize the spare capacity. this can amortize per-call overheads
 // - and finally pass not-too-small and not-too-large buffers to Windows read APIs because they manage to suffer from both problems
-//   at the same time, i.e. small reads suffer from syscall overhead, all reads incur initialization cost
-//   proportional to buffer size (#110650)
+//   at the same time, i.e. small reads suffer from syscall overhead, all reads incur costs proportional to buffer size (#110650)
 //
 pub(crate) fn default_read_to_end<R: Read + ?Sized>(
     r: &mut R,
@@ -444,6 +443,8 @@ pub(crate) fn default_read_to_end<R: Read + ?Sized>(
         }
     }
 
+    let mut consecutive_short_reads = 0;
+
     loop {
         if buf.len() == buf.capacity() && buf.capacity() == start_cap {
             // The buffer might be an exact fit. Let's read into a probe buffer
@@ -489,6 +490,12 @@ pub(crate) fn default_read_to_end<R: Read + ?Sized>(
             return Ok(buf.len() - start_len);
         }
 
+        if bytes_read < buf_len {
+            consecutive_short_reads += 1;
+        } else {
+            consecutive_short_reads = 0;
+        }
+
         // store how much was initialized but not filled
         initialized = unfilled_but_initialized;
 
@@ -503,7 +510,10 @@ pub(crate) fn default_read_to_end<R: Read + ?Sized>(
             // The reader is returning short reads but it doesn't call ensure_init().
             // In that case we no longer need to restrict read sizes to avoid
             // initialization costs.
-            if !was_fully_initialized {
+            // When reading from disk we usually don't get any short reads except at EOF.
+            // So we wait for at least 2 short reads before uncapping the read buffer;
+            // this helps with the Windows issue.
+            if !was_fully_initialized && consecutive_short_reads > 1 {
                 max_read_size = usize::MAX;
             }
 

library/std/src/lib.rs

@@ -32,13 +32,17 @@
 //!
 //! Once you are familiar with the contents of the standard library you may
 //! begin to find the verbosity of the prose distracting. At this stage in your
-//! development you may want to press the `[-]` button near the top of the
-//! page to collapse it into a more skimmable view.
-//!
-//! While you are looking at that `[-]` button also notice the `source`
-//! link. Rust's API documentation comes with the source code and you are
-//! encouraged to read it. The standard library source is generally high
-//! quality and a peek behind the curtains is often enlightening.
+//! development you may want to press the <code>
+//! <svg width="0.75rem" height="0.75rem" viewBox="0 0 12 12"
+//! stroke="currentColor" fill="none">
+//! <path d="M2,2l4,4l4,-4M2,6l4,4l4,-4"/></svg> Summary</code> button near the
+//! top of the page to collapse it into a more skimmable view.
+//!
+//! While you are looking at the top of the page, also notice the
+//! <code>source</code> link. Rust's API documentation comes with the source
+//! code and you are encouraged to read it. The standard library source is
+//! generally high quality and a peek behind the curtains is
+//! often enlightening.
 //!
 //! # What is in the standard library documentation?
 //!

src/librustdoc/html/sources.rs

@@ -26,8 +26,11 @@ pub(crate) fn render(cx: &mut Context<'_>, krate: &clean::Crate) -> Result<(), E
 
     let dst = cx.dst.join("src").join(krate.name(cx.tcx()).as_str());
     cx.shared.ensure_dir(&dst)?;
+    let crate_name = krate.name(cx.tcx());
+    let crate_name = crate_name.as_str();
 
-    let mut collector = SourceCollector { dst, cx, emitted_local_sources: FxHashSet::default() };
+    let mut collector =
+        SourceCollector { dst, cx, emitted_local_sources: FxHashSet::default(), crate_name };
     collector.visit_crate(krate);
     Ok(())
 }
@@ -115,6 +118,8 @@ struct SourceCollector<'a, 'tcx> {
     /// Root destination to place all HTML output into
     dst: PathBuf,
     emitted_local_sources: FxHashSet<PathBuf>,
+
+    crate_name: &'a str,
 }
 
 impl DocVisitor for SourceCollector<'_, '_> {
@@ -210,19 +215,22 @@ impl SourceCollector<'_, '_> {
             },
         );
 
+        let src_fname = p.file_name().expect("source has no filename").to_os_string();
+        let mut fname = src_fname.clone();
+
         let root_path = PathBuf::from("../../").join(root_path.into_inner());
         let mut root_path = root_path.to_string_lossy();
         if let Some(c) = root_path.as_bytes().last()
             && *c != b'/'
         {
             root_path += "/";
         }
+        let mut file_path = Path::new(&self.crate_name).join(&*cur.borrow());
+        file_path.push(&fname);
+        fname.push(".html");
         let mut cur = self.dst.join(cur.into_inner());
         shared.ensure_dir(&cur)?;
 
-        let src_fname = p.file_name().expect("source has no filename").to_os_string();
-        let mut fname = src_fname.clone();
-        fname.push(".html");
         cur.push(&fname);
 
         let title = format!("{} - source", src_fname.to_string_lossy());
@@ -250,7 +258,7 @@ impl SourceCollector<'_, '_> {
                     cx,
                     &root_path,
                     highlight::DecorationInfo::default(),
-                    SourceContext::Standalone,
+                    SourceContext::Standalone { file_path },
                 )
             },
             &shared.style_files,
@@ -312,10 +320,11 @@ struct ScrapedSource<'a, Code: std::fmt::Display> {
 struct Source<Code: std::fmt::Display> {
     lines: RangeInclusive<usize>,
     code_html: Code,
+    file_path: Option<(String, String)>,
 }
 
 pub(crate) enum SourceContext<'a> {
-    Standalone,
+    Standalone { file_path: PathBuf },
     Embedded(ScrapedInfo<'a>),
 }
 
@@ -344,9 +353,19 @@ pub(crate) fn print_src(
     });
     let lines = s.lines().count();
     match source_context {
-        SourceContext::Standalone => {
-            Source { lines: (1..=lines), code_html: code }.render_into(&mut writer).unwrap()
+        SourceContext::Standalone { file_path } => Source {
+            lines: (1..=lines),
+            code_html: code,
+            file_path: if let Some(file_name) = file_path.file_name()
+                && let Some(file_path) = file_path.parent()
+            {
+                Some((file_path.display().to_string(), file_name.display().to_string()))
+            } else {
+                None
+            },
         }
+        .render_into(&mut writer)
+        .unwrap(),
         SourceContext::Embedded(info) => {
             let lines = (1 + info.offset)..=(lines + info.offset);
             ScrapedSource { info, lines, code_html: code }.render_into(&mut writer).unwrap();

src/librustdoc/html/static/css/noscript.css

@@ -61,6 +61,8 @@ nav.sub {
 	--copy-path-img-hover-filter: invert(35%);
 	--code-example-button-color: #7f7f7f;
 	--code-example-button-hover-color: #595959;
+	--settings-menu-filter: invert(50%);
+	--settings-menu-hover-filter: invert(35%);
 	--codeblock-error-hover-color: rgb(255, 0, 0);
 	--codeblock-error-color: rgba(255, 0, 0, .5);
 	--codeblock-ignore-hover-color: rgb(255, 142, 0);
@@ -87,7 +89,6 @@ nav.sub {
 	--search-tab-button-not-selected-background: #e6e6e6;
 	--search-tab-button-selected-border-top-color: #0089ff;
 	--search-tab-button-selected-background: #fff;
-	--settings-menu-filter: none;
 	--stab-background-color: #fff5d6;
 	--stab-code-color: #000;
 	--code-highlight-kw-color: #8959a8;
@@ -192,6 +193,8 @@ nav.sub {
 		--search-tab-button-not-selected-background: #252525;
 		--search-tab-button-selected-border-top-color: #0089ff;
 		--search-tab-button-selected-background: #353535;
+		--settings-menu-filter: invert(50%);
+		--settings-menu-hover-filter: invert(65%);
 		--stab-background-color: #314559;
 		--stab-code-color: #e6e1cf;
 		--code-highlight-kw-color: #ab8ac1;