Auto merge of #88143 - GuillaumeGomez:rollup-sgh318f, r=GuillaumeGomez

Rollup of 10 pull requests

Successful merges:

 - #87818 (Fix anchors display in rustdoc)
 - #87983 (Use more accurate spans when proposing adding lifetime to item)
 - #88012 (Change WASI's `RawFd` from `u32` to `c_int` (`i32`).)
 - #88031 (Make `BuildHasher` object safe)
 - #88036 (Fix dead code warning when inline const is used in pattern)
 - #88082 (Take into account jobs number for rustdoc GUI tests)
 - #88109 (Fix environment variable getter docs)
 - #88111 (Add background-color on clickable definitions in source code)
 - #88129 (Fix dataflow graphviz bug, make dataflow graphviz modules public)
 - #88136 (Move private_unused.rs test to impl-trait)

Failed merges:

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

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

@@ -33,7 +33,7 @@ pub trait DebugWithContext<C>: Eq + fmt::Debug {
         }
 
         write!(f, "\u{001f}-")?;
-        self.fmt_with(ctxt, f)
+        old.fmt_with(ctxt, f)
     }
 }
 

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

@@ -42,7 +42,7 @@ mod cursor;
 mod direction;
 mod engine;
 pub mod fmt;
-mod graphviz;
+pub mod graphviz;
 pub mod lattice;
 mod visitor;
 

compiler/rustc_mir/src/dataflow/mod.rs

@@ -5,7 +5,7 @@ use rustc_span::symbol::{sym, Symbol};
 
 pub(crate) use self::drop_flag_effects::*;
 pub use self::framework::{
-    fmt, lattice, visit_results, Analysis, AnalysisDomain, Backward, BorrowckFlowState,
+    fmt, graphviz, lattice, visit_results, Analysis, AnalysisDomain, Backward, BorrowckFlowState,
     BorrowckResults, Engine, Forward, GenKill, GenKillAnalysis, JoinSemiLattice, Results,
     ResultsCursor, ResultsRefCursor, ResultsVisitor, SwitchIntEdgeEffects,
 };

compiler/rustc_mir/src/util/mod.rs

@@ -18,4 +18,4 @@ pub use self::alignment::is_disaligned;
 pub use self::find_self_call::find_self_call;
 pub use self::generic_graph::graphviz_safe_def_name;
 pub use self::graphviz::write_mir_graphviz;
-pub use self::pretty::{dump_enabled, dump_mir, write_mir_pretty, PassWhere};
+pub use self::pretty::{dump_enabled, dump_mir, write_mir_fn, write_mir_pretty, PassWhere};

compiler/rustc_passes/src/dead.rs

@@ -15,6 +15,7 @@ use rustc_middle::middle::privacy;
 use rustc_middle::ty::{self, DefIdTree, TyCtxt};
 use rustc_session::lint;
 use rustc_span::symbol::{sym, Symbol};
+use std::mem;
 
 // Any local node that may call something in its body block should be
 // explored. For example, if it's a live Node::Item that is a
@@ -395,8 +396,14 @@ impl<'tcx> Visitor<'tcx> for MarkSymbolVisitor<'tcx> {
     }
 
     fn visit_anon_const(&mut self, c: &'tcx hir::AnonConst) {
+        // When inline const blocks are used in pattern position, paths
+        // referenced by it should be considered as used.
+        let in_pat = mem::replace(&mut self.in_pat, false);
+
         self.live_symbols.insert(self.tcx.hir().local_def_id(c.hir_id));
         intravisit::walk_anon_const(self, c);
+
+        self.in_pat = in_pat;
     }
 }
 

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -2073,20 +2073,85 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
                         continue;
                     }
                 });
+
+                struct Lifetime(Span, String);
+                impl Lifetime {
+                    fn is_unnamed(&self) -> bool {
+                        self.1.starts_with('&') && !self.1.starts_with("&'")
+                    }
+                    fn is_underscore(&self) -> bool {
+                        self.1.starts_with("&'_ ")
+                    }
+                    fn is_named(&self) -> bool {
+                        self.1.starts_with("&'")
+                    }
+                    fn suggestion(&self, sugg: String) -> Option<(Span, String)> {
+                        Some(
+                            match (
+                                self.is_unnamed(),
+                                self.is_underscore(),
+                                self.is_named(),
+                                sugg.starts_with("&"),
+                            ) {
+                                (true, _, _, false) => (self.span_unnamed_borrow(), sugg),
+                                (true, _, _, true) => {
+                                    (self.span_unnamed_borrow(), sugg[1..].to_string())
+                                }
+                                (_, true, _, false) => {
+                                    (self.span_underscore_borrow(), sugg.trim().to_string())
+                                }
+                                (_, true, _, true) => {
+                                    (self.span_underscore_borrow(), sugg[1..].trim().to_string())
+                                }
+                                (_, _, true, false) => {
+                                    (self.span_named_borrow(), sugg.trim().to_string())
+                                }
+                                (_, _, true, true) => {
+                                    (self.span_named_borrow(), sugg[1..].trim().to_string())
+                                }
+                                _ => return None,
+                            },
+                        )
+                    }
+                    fn span_unnamed_borrow(&self) -> Span {
+                        let lo = self.0.lo() + BytePos(1);
+                        self.0.with_lo(lo).with_hi(lo)
+                    }
+                    fn span_named_borrow(&self) -> Span {
+                        let lo = self.0.lo() + BytePos(1);
+                        self.0.with_lo(lo)
+                    }
+                    fn span_underscore_borrow(&self) -> Span {
+                        let lo = self.0.lo() + BytePos(1);
+                        let hi = lo + BytePos(2);
+                        self.0.with_lo(lo).with_hi(hi)
+                    }
+                }
+
                 for param in params {
                     if let Ok(snippet) = self.tcx.sess.source_map().span_to_snippet(param.span) {
-                        if snippet.starts_with('&') && !snippet.starts_with("&'") {
-                            introduce_suggestion
-                                .push((param.span, format!("&'a {}", &snippet[1..])));
-                        } else if let Some(stripped) = snippet.strip_prefix("&'_ ") {
-                            introduce_suggestion.push((param.span, format!("&'a {}", &stripped)));
+                        if let Some((span, sugg)) =
+                            Lifetime(param.span, snippet).suggestion("'a ".to_string())
+                        {
+                            introduce_suggestion.push((span, sugg));
                         }
                     }
                 }
-                for ((span, _), sugg) in spans_with_counts.iter().copied().zip(suggs.iter()) {
-                    if let Some(sugg) = sugg {
-                        introduce_suggestion.push((span, sugg.to_string()));
-                    }
+                for (span, sugg) in spans_with_counts.iter().copied().zip(suggs.iter()).filter_map(
+                    |((span, _), sugg)| match &sugg {
+                        Some(sugg) => Some((span, sugg.to_string())),
+                        _ => None,
+                    },
+                ) {
+                    let (span, sugg) = self
+                        .tcx
+                        .sess
+                        .source_map()
+                        .span_to_snippet(span)
+                        .ok()
+                        .and_then(|snippet| Lifetime(span, snippet).suggestion(sugg.clone()))
+                        .unwrap_or((span, sugg));
+                    introduce_suggestion.push((span, sugg.to_string()));
                 }
                 err.multipart_suggestion_with_style(
                     &msg,
@@ -2159,7 +2224,8 @@ impl<'tcx> LifetimeContext<'_, 'tcx> {
                 for ((span, _), snippet) in spans_with_counts.iter().copied().zip(snippets.iter()) {
                     match snippet.as_deref() {
                         Some("") => spans_suggs.push((span, "'lifetime, ".to_string())),
-                        Some("&") => spans_suggs.push((span, "&'lifetime ".to_string())),
+                        Some("&") => spans_suggs
+                            .push((span.with_lo(span.lo() + BytePos(1)), "'lifetime ".to_string())),
                         _ => {}
                     }
                 }

library/core/src/hash/mod.rs

@@ -520,7 +520,10 @@ pub trait BuildHasher {
     /// );
     /// ```
     #[unstable(feature = "build_hasher_simple_hash_one", issue = "86161")]
-    fn hash_one<T: Hash>(&self, x: T) -> u64 {
+    fn hash_one<T: Hash>(&self, x: T) -> u64
+    where
+        Self: Sized,
+    {
         let mut hasher = self.build_hasher();
         x.hash(&mut hasher);
         hasher.finish()

library/core/tests/hash/mod.rs

@@ -1,7 +1,7 @@
 mod sip;
 
 use std::default::Default;
-use std::hash::{Hash, Hasher};
+use std::hash::{BuildHasher, Hash, Hasher};
 use std::rc::Rc;
 
 struct MyHasher {
@@ -139,3 +139,10 @@ fn test_indirect_hasher() {
     }
     assert_eq!(hasher.hash, 5);
 }
+
+#[test]
+fn test_build_hasher_object_safe() {
+    use std::collections::hash_map::{DefaultHasher, RandomState};
+
+    let _: &dyn BuildHasher<Hasher = DefaultHasher> = &RandomState::new();
+}

library/std/src/env.rs

@@ -185,9 +185,13 @@ impl fmt::Debug for VarsOs {
 ///
 /// # Errors
 ///
-/// Returns `[None]` if the environment variable isn't set.
-/// Returns `[None]` if the environment variable is not valid Unicode. If this is not
-/// desired, consider using [`var_os`].
+/// This function will return an error if the environment variable isn't set.
+///
+/// This function may return an error if the environment variable's name contains
+/// the equal sign character (`=`) or the NUL character.
+///
+/// This function will return an error if the environment variable's value is
+/// not valid Unicode. If this is not desired, consider using [`var_os`].
 ///
 /// # Examples
 ///
@@ -221,8 +225,13 @@ fn _var(key: &OsStr) -> Result<String, VarError> {
 ///
 /// # Errors
 ///
-/// Returns `[None]` if the variable isn't set.
-/// May return `[None]` if the variable value contains the NUL character.
+/// This function returns an error if the environment variable isn't set.
+///
+/// This function may return an error if the environment variable's name contains
+/// the equal sign character (`=`) or the NUL character.
+///
+/// This function may return an error if the environment variable's value contains
+/// the NUL character.
 ///
 /// # Examples
 ///

library/std/src/os/wasi/io.rs

@@ -6,11 +6,18 @@
 use crate::fs;
 use crate::io;
 use crate::net;
+use crate::os::raw;
 use crate::sys;
 use crate::sys_common::{AsInner, FromInner, IntoInner};
 
 /// Raw file descriptors.
-pub type RawFd = u32;
+///
+/// This has type `c_int` to ease compatibility with code that also compiles on
+/// Unix configurations, however unlike Unix and POSIX, in WASI negative file
+/// descriptors are valid. Only `-1` is reserved for indicating errors. Code
+/// intending to be portable across Unix platforms and WASI should avoid
+/// assuming that negative file descriptors are invalid.
+pub type RawFd = raw::c_int;
 
 /// A trait to extract the raw WASI file descriptor from an underlying
 /// object.
@@ -161,41 +168,41 @@ impl IntoRawFd for fs::File {
 impl AsRawFd for io::Stdin {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDIN_FILENO as RawFd
+        libc::STDIN_FILENO
     }
 }
 
 impl AsRawFd for io::Stdout {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDOUT_FILENO as RawFd
+        libc::STDOUT_FILENO
     }
 }
 
 impl AsRawFd for io::Stderr {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDERR_FILENO as RawFd
+        libc::STDERR_FILENO
     }
 }
 
 impl<'a> AsRawFd for io::StdinLock<'a> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDIN_FILENO as RawFd
+        libc::STDIN_FILENO
     }
 }
 
 impl<'a> AsRawFd for io::StdoutLock<'a> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDOUT_FILENO as RawFd
+        libc::STDOUT_FILENO
     }
 }
 
 impl<'a> AsRawFd for io::StderrLock<'a> {
     #[inline]
     fn as_raw_fd(&self) -> RawFd {
-        libc::STDERR_FILENO as RawFd
+        libc::STDERR_FILENO
     }
 }