Auto merge of #76804 - tmandry:rollup-nwntt3q, r=tmandry

Rollup of 16 pull requests

Successful merges:

 - #75026 (Add array_windows fn)
 - #76642 (Do not lint ignored private doc tests)
 - #76719 (Change error message for ty param in const)
 - #76721 (Use intra-doc links in `core::mem`)
 - #76728 (Add a comment why `extern crate` is necessary for rustdoc)
 - #76735 (Remove unnecessary `clone()`s in bootstrap)
 - #76741 (Avoid printing dry run timings)
 - #76747 (Add missing code examples in libcore)
 - #76756 (fix a couple of stylistic clippy warnings)
 - #76758 ([fuchsia] Propagate the userspace UTC clock)
 - #76759 (Fix stabilization marker for future_readiness_fns)
 - #76760 (don't lazily evaluate some trivial values for Option::None replacements (clippy::unnecessary_lazy_evaluations))
 - #76764 (Update books)
 - #76775 (Strip a single leading tab when rendering dataflow diffs)
 - #76778 (Simplify iter fuse struct doc)
 - #76794 (Make graphviz font configurable)

Failed merges:

r? `@ghost`

compiler/rustc_graphviz/src/lib.rs

@@ -591,14 +591,14 @@ pub trait GraphWalk<'a> {
     fn target(&'a self, edge: &Self::Edge) -> Self::Node;
 }
 
-#[derive(Copy, Clone, PartialEq, Eq, Debug)]
+#[derive(Clone, PartialEq, Eq, Debug)]
 pub enum RenderOption {
     NoEdgeLabels,
     NoNodeLabels,
     NoEdgeStyles,
     NoNodeStyles,
 
-    Monospace,
+    Fontname(String),
     DarkTheme,
 }
 
@@ -633,11 +633,14 @@ where
     // Global graph properties
     let mut graph_attrs = Vec::new();
     let mut content_attrs = Vec::new();
-    if options.contains(&RenderOption::Monospace) {
-        let font = r#"fontname="Courier, monospace""#;
-        graph_attrs.push(font);
-        content_attrs.push(font);
-    };
+    let font;
+    if let Some(fontname) = options.iter().find_map(|option| {
+        if let RenderOption::Fontname(fontname) = option { Some(fontname) } else { None }
+    }) {
+        font = format!(r#"fontname="{}""#, fontname);
+        graph_attrs.push(&font[..]);
+        content_attrs.push(&font[..]);
+    }
     if options.contains(&RenderOption::DarkTheme) {
         graph_attrs.push(r#"bgcolor="black""#);
         content_attrs.push(r#"color="white""#);

compiler/rustc_infer/src/infer/error_reporting/nice_region_error/named_anon_conflict.rs

@@ -85,7 +85,7 @@ impl<'a, 'tcx> NiceRegionError<'a, 'tcx> {
 
                 debug!("try_report_named_anon_conflict: ret ty {:?}", ty);
                 if sub == &ty::ReStatic
-                    && v.0.into_iter().find(|t| t.span.desugaring_kind().is_none()).is_some()
+                    && v.0.into_iter().any(|t| t.span.desugaring_kind().is_none())
                 {
                     // If the failure is due to a `'static` requirement coming from a `dyn` or
                     // `impl` Trait that *isn't* caused by `async fn` desugaring, handle this case

compiler/rustc_lint/src/builtin.rs

@@ -961,7 +961,7 @@ fn warn_if_doc(cx: &EarlyContext<'_>, node_span: Span, node_kind: &str, attrs: &
             continue;
         }
 
-        let span = sugared_span.take().unwrap_or_else(|| attr.span);
+        let span = sugared_span.take().unwrap_or(attr.span);
 
         if attr.is_doc_comment() || cx.sess().check_name(attr, sym::doc) {
             cx.struct_span_lint(UNUSED_DOC_COMMENTS, span, |lint| {

compiler/rustc_metadata/src/native_libs.rs

@@ -170,7 +170,7 @@ impl Collector<'tcx> {
             feature_err(
                 &self.tcx.sess.parse_sess,
                 sym::static_nobundle,
-                span.unwrap_or_else(|| rustc_span::DUMMY_SP),
+                span.unwrap_or(rustc_span::DUMMY_SP),
                 "kind=\"static-nobundle\" is unstable",
             )
             .emit();
@@ -179,7 +179,7 @@ impl Collector<'tcx> {
             feature_err(
                 &self.tcx.sess.parse_sess,
                 sym::raw_dylib,
-                span.unwrap_or_else(|| rustc_span::DUMMY_SP),
+                span.unwrap_or(rustc_span::DUMMY_SP),
                 "kind=\"raw-dylib\" is unstable",
             )
             .emit();

compiler/rustc_middle/src/ty/print/pretty.rs

@@ -273,10 +273,10 @@ pub trait PrettyPrinter<'tcx>:
         }
 
         match self.tcx().trimmed_def_paths(LOCAL_CRATE).get(&def_id) {
-            None => return Ok((self, false)),
+            None => Ok((self, false)),
             Some(symbol) => {
                 self.write_str(&symbol.as_str())?;
-                return Ok((self, true));
+                Ok((self, true))
             }
         }
     }

compiler/rustc_mir/src/borrow_check/diagnostics/region_errors.rs

@@ -387,7 +387,7 @@ impl<'a, 'tcx> MirBorrowckCtxt<'a, 'tcx> {
         if let ReturnConstraint::ClosureUpvar(upvar) = kind {
             let def_id = match self.regioncx.universal_regions().defining_ty {
                 DefiningTy::Closure(def_id, _) => def_id,
-                ty @ _ => bug!("unexpected DefiningTy {:?}", ty),
+                ty => bug!("unexpected DefiningTy {:?}", ty),
             };
 
             let upvar_def_span = self.infcx.tcx.hir().span(upvar);

compiler/rustc_mir/src/dataflow/framework/engine.rs

@@ -306,7 +306,8 @@ where
     let mut buf = Vec::new();
 
     let graphviz = graphviz::Formatter::new(body, def_id, results, style);
-    let mut render_opts = vec![dot::RenderOption::Monospace];
+    let mut render_opts =
+        vec![dot::RenderOption::Fontname(tcx.sess.opts.debugging_opts.graphviz_font.clone())];
     if tcx.sess.opts.debugging_opts.graphviz_dark_mode {
         render_opts.push(dot::RenderOption::DarkTheme);
     }

compiler/rustc_mir/src/dataflow/framework/graphviz.rs

@@ -578,7 +578,7 @@ where
         return String::new();
     }
 
-    let re = Regex::new("\u{001f}([+-])").unwrap();
+    let re = Regex::new("\t?\u{001f}([+-])").unwrap();
 
     let raw_diff = format!("{:#?}", DebugDiffWithAdapter { new, old, ctxt });
 

compiler/rustc_mir/src/transform/instcombine.rs

@@ -126,7 +126,7 @@ impl OptimizationFinder<'b, 'tcx> {
             }
         }
 
-        return None;
+        None
     }
 }
 

compiler/rustc_mir/src/util/graphviz.rs

@@ -55,9 +55,9 @@ where
     writeln!(w, "{} {}Mir_{} {{", kind, cluster, def_name)?;
 
     // Global graph properties
-    let font = r#"fontname="Courier, monospace""#;
-    let mut graph_attrs = vec![font];
-    let mut content_attrs = vec![font];
+    let font = format!(r#"fontname="{}""#, tcx.sess.opts.debugging_opts.graphviz_font);
+    let mut graph_attrs = vec![&font[..]];
+    let mut content_attrs = vec![&font[..]];
 
     let dark_mode = tcx.sess.opts.debugging_opts.graphviz_dark_mode;
     if dark_mode {

compiler/rustc_resolve/src/diagnostics.rs

@@ -466,7 +466,7 @@ impl<'a> Resolver<'a> {
                 );
                 err
             }
-            ResolutionError::ParamInNonTrivialAnonConst(name) => {
+            ResolutionError::ParamInNonTrivialAnonConst { name, is_type } => {
                 let mut err = self.session.struct_span_err(
                     span,
                     "generic parameters must not be used inside of non trivial constant values",
@@ -478,9 +478,17 @@ impl<'a> Resolver<'a> {
                         name
                     ),
                 );
-                err.help(
-                    &format!("it is currently only allowed to use either `{0}` or `{{ {0} }}` as generic constants", name)
-                );
+
+                if is_type {
+                    err.note("type parameters are currently not permitted in anonymous constants");
+                } else {
+                    err.help(
+                        &format!("it is currently only allowed to use either `{0}` or `{{ {0} }}` as generic constants",
+                                 name
+                        )
+                    );
+                }
+
                 err
             }
             ResolutionError::SelfInTyParamDefault => {

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -1534,7 +1534,7 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
             }
         };
 
-        let lifetime_names: Vec<_> = lifetime_names.into_iter().collect();
+        let lifetime_names: Vec<_> = lifetime_names.iter().collect();
         match (&lifetime_names[..], snippet.as_deref()) {
             ([name], Some("&")) => {
                 suggest_existing(err, &name.as_str()[..], &|name| format!("&{} ", name));

compiler/rustc_resolve/src/lib.rs

@@ -221,7 +221,7 @@ enum ResolutionError<'a> {
     /// generic parameters must not be used inside of non trivial constant values.
     ///
     /// This error is only emitted when using `min_const_generics`.
-    ParamInNonTrivialAnonConst(Symbol),
+    ParamInNonTrivialAnonConst { name: Symbol, is_type: bool },
     /// Error E0735: type parameters with a default cannot use `Self`
     SelfInTyParamDefault,
     /// Error E0767: use of unreachable label
@@ -2638,9 +2638,10 @@ impl<'a> Resolver<'a> {
                                     if record_used {
                                         self.report_error(
                                             span,
-                                            ResolutionError::ParamInNonTrivialAnonConst(
-                                                rib_ident.name,
-                                            ),
+                                            ResolutionError::ParamInNonTrivialAnonConst {
+                                                name: rib_ident.name,
+                                                is_type: true,
+                                            },
                                         );
                                     }
                                     return Res::Err;
@@ -2718,7 +2719,10 @@ impl<'a> Resolver<'a> {
                                 if record_used {
                                     self.report_error(
                                         span,
-                                        ResolutionError::ParamInNonTrivialAnonConst(rib_ident.name),
+                                        ResolutionError::ParamInNonTrivialAnonConst {
+                                            name: rib_ident.name,
+                                            is_type: false,
+                                        },
                                     );
                                 }
                                 return Res::Err;

compiler/rustc_session/src/config.rs

@@ -1762,6 +1762,10 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         debugging_opts.symbol_mangling_version = SymbolManglingVersion::V0;
     }
 
+    if let Ok(graphviz_font) = std::env::var("RUSTC_GRAPHVIZ_FONT") {
+        debugging_opts.graphviz_font = graphviz_font;
+    }
+
     if !cg.embed_bitcode {
         match cg.lto {
             LtoCli::No | LtoCli::Unspecified => {}

compiler/rustc_session/src/options.rs

@@ -911,6 +911,9 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "set the optimization fuel quota for a crate"),
     graphviz_dark_mode: bool = (false, parse_bool, [UNTRACKED],
         "use dark-themed colors in graphviz output (default: no)"),
+    graphviz_font: String = ("Courier, monospace".to_string(), parse_string, [UNTRACKED],
+        "use the given `fontname` in graphviz output; can be overridden by setting \
+        environment variable `RUSTC_GRAPHVIZ_FONT` (default: `Courier, monospace`)"),
     hir_stats: bool = (false, parse_bool, [UNTRACKED],
         "print some statistics about AST and HIR (default: no)"),
     human_readable_cgu_names: bool = (false, parse_bool, [TRACKED],

compiler/rustc_trait_selection/src/traits/coherence.rs

@@ -182,7 +182,7 @@ fn overlap_within_probe(
     }
 
     if !skip_leak_check.is_yes() {
-        if let Err(_) = infcx.leak_check(true, snapshot) {
+        if infcx.leak_check(true, snapshot).is_err() {
             debug!("overlap: leak check failed");
             return None;
         }

compiler/rustc_typeck/src/check/_match.rs

@@ -164,7 +164,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
                     }
                     // If all the obligations hold (or there are no obligations) the tail expression
                     // we can suggest to return a boxed trait object instead of an opaque type.
-                    if suggest_box { self.ret_type_span.clone() } else { None }
+                    if suggest_box { self.ret_type_span } else { None }
                 }
                 _ => None,
             };

compiler/rustc_typeck/src/check/expr.rs

@@ -1243,10 +1243,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else if check_completeness && !error_happened && !remaining_fields.is_empty() {
             let no_accessible_remaining_fields = remaining_fields
                 .iter()
-                .filter(|(_, (_, field))| {
+                .find(|(_, (_, field))| {
                     field.vis.is_accessible_from(tcx.parent_module(expr_id).to_def_id(), tcx)
                 })
-                .next()
                 .is_none();
 
             if no_accessible_remaining_fields {

compiler/rustc_typeck/src/check/pat.rs

@@ -1141,10 +1141,9 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
         } else if !etc && !unmentioned_fields.is_empty() {
             let no_accessible_unmentioned_fields = unmentioned_fields
                 .iter()
-                .filter(|(field, _)| {
+                .find(|(field, _)| {
                     field.vis.is_accessible_from(tcx.parent_module(pat.hir_id).to_def_id(), tcx)
                 })
-                .next()
                 .is_none();
 
             if no_accessible_unmentioned_fields {

library/alloc/src/lib.rs

@@ -76,6 +76,7 @@
 #![cfg_attr(test, feature(test))]
 #![feature(allocator_api)]
 #![feature(array_chunks)]
+#![feature(array_windows)]
 #![feature(allow_internal_unstable)]
 #![feature(arbitrary_self_types)]
 #![feature(box_patterns)]

library/alloc/src/slice.rs

@@ -97,6 +97,8 @@ pub use core::slice::check_range;
 pub use core::slice::ArrayChunks;
 #[unstable(feature = "array_chunks", issue = "74985")]
 pub use core::slice::ArrayChunksMut;
+#[unstable(feature = "array_windows", issue = "75027")]
+pub use core::slice::ArrayWindows;
 #[stable(feature = "slice_get_slice", since = "1.28.0")]
 pub use core::slice::SliceIndex;
 #[stable(feature = "from_ref", since = "1.28.0")]

library/core/src/future/mod.rs

@@ -21,9 +21,9 @@ pub use self::future::Future;
 #[unstable(feature = "into_future", issue = "67644")]
 pub use into_future::IntoFuture;
 
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 pub use pending::{pending, Pending};
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 pub use ready::{ready, Ready};
 
 #[unstable(feature = "future_poll_fn", issue = "72302")]

library/core/src/future/pending.rs

@@ -11,7 +11,7 @@ use crate::task::{Context, Poll};
 /// documentation for more.
 ///
 /// [`pending`]: fn.pending.html
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Pending<T> {
     _data: marker::PhantomData<T>,
@@ -31,12 +31,12 @@ pub struct Pending<T> {
 /// unreachable!();
 /// # }
 /// ```
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 pub fn pending<T>() -> Pending<T> {
     Pending { _data: marker::PhantomData }
 }
 
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 impl<T> Future for Pending<T> {
     type Output = T;
 
@@ -45,17 +45,17 @@ impl<T> Future for Pending<T> {
     }
 }
 
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 impl<T> Unpin for Pending<T> {}
 
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 impl<T> Debug for Pending<T> {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
         f.debug_struct("Pending").finish()
     }
 }
 
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 impl<T> Clone for Pending<T> {
     fn clone(&self) -> Self {
         pending()

library/core/src/future/ready.rs

@@ -8,15 +8,15 @@ use crate::task::{Context, Poll};
 /// documentation for more.
 ///
 /// [`ready`]: fn.ready.html
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 #[derive(Debug, Clone)]
 #[must_use = "futures do nothing unless you `.await` or poll them"]
 pub struct Ready<T>(Option<T>);
 
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 impl<T> Unpin for Ready<T> {}
 
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 impl<T> Future for Ready<T> {
     type Output = T;
 
@@ -42,7 +42,7 @@ impl<T> Future for Ready<T> {
 /// assert_eq!(a.await, 1);
 /// # }
 /// ```
-#[stable(feature = "future_readiness_fns", since = "1.47.0")]
+#[stable(feature = "future_readiness_fns", since = "1.48.0")]
 pub fn ready<T>(t: T) -> Ready<T> {
     Ready(Some(t))
 }

library/core/src/iter/adapters/fuse.rs

@@ -9,11 +9,8 @@ use crate::ops::Try;
 /// An iterator that yields `None` forever after the underlying iterator
 /// yields `None` once.
 ///
-/// This `struct` is created by the [`fuse`] method on [`Iterator`]. See its
-/// documentation for more.
-///
-/// [`fuse`]: trait.Iterator.html#method.fuse
-/// [`Iterator`]: trait.Iterator.html
+/// This `struct` is created by [`Iterator::fuse`]. See its documentation
+/// for more.
 #[derive(Clone, Debug)]
 #[must_use = "iterators are lazy and do nothing unless consumed"]
 #[stable(feature = "rust1", since = "1.0.0")]