Auto merge of #67048 - RalfJung:rollup-drjnmt0, r=RalfJung

Rollup of 13 pull requests

Successful merges:

 - #66405 (Tweak `ObligationForest` `NodeState`s)
 - #66730 (remove dependency from libhermit)
 - #66764 (Tweak wording of `collect()` on bad target type)
 - #66899 (Standard library support for riscv64gc-unknown-linux-gnu)
 - #66900 (Clean up error codes)
 - #66974 ([CI] fix the `! isCI` check in src/ci/run.sh)
 - #66979 (Add long error for E0631 and update ui tests.)
 - #67005 (capitalize Rust)
 - #67010 (Accurately portray raw identifiers in error messages)
 - #67011 (Include a span in more `expected...found` notes)
 - #67017 (cleanup long error explanations)
 - #67021 (Fix docs for formatting delegations)
 - #67041 (add ExitStatusExt into prelude)

Failed merges:

r? @ghost

Cargo.lock

@@ -1823,9 +1823,9 @@ checksum = "b294d6fa9ee409a054354afc4352b0b9ef7ca222c69b8812cbea9e7d2bf3783f"
 
 [[package]]
 name = "libc"
-version = "0.2.64"
+version = "0.2.66"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "74dfca3d9957906e8d1e6a0b641dc9a59848e793f1da2165889fd4f62d10d79c"
+checksum = "d515b1f41455adea1313a4a2ac8a8a477634fbae63cc6100e3aebb207ce61558"
 dependencies = [
  "rustc-std-workspace-core",
 ]

src/ci/run.sh

@@ -23,7 +23,7 @@ fi
 ci_dir=`cd $(dirname $0) && pwd`
 source "$ci_dir/shared.sh"
 
-if [ ! isCI ] || isCiBranch auto || isCiBranch beta; then
+if ! isCI || isCiBranch auto || isCiBranch beta; then
     RUST_CONFIGURE_ARGS="$RUST_CONFIGURE_ARGS --set build.print-step-timings --enable-verbose-tests"
 fi
 

src/libcore/fmt/mod.rs

@@ -662,7 +662,7 @@ pub trait Display {
 ///     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 ///         let val = self.0;
 ///
-///         write!(f, "{:o}", val) // delegate to i32's implementation
+///         fmt::Octal::fmt(&val, f) // delegate to i32's implementation
 ///     }
 /// }
 ///
@@ -712,7 +712,7 @@ pub trait Octal {
 ///     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 ///         let val = self.0;
 ///
-///         write!(f, "{:b}", val) // delegate to i32's implementation
+///         fmt::Binary::fmt(&val, f) // delegate to i32's implementation
 ///     }
 /// }
 ///
@@ -771,7 +771,7 @@ pub trait Binary {
 ///     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 ///         let val = self.0;
 ///
-///         write!(f, "{:x}", val) // delegate to i32's implementation
+///         fmt::LowerHex::fmt(&val, f) // delegate to i32's implementation
 ///     }
 /// }
 ///
@@ -824,7 +824,7 @@ pub trait LowerHex {
 ///     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 ///         let val = self.0;
 ///
-///         write!(f, "{:X}", val) // delegate to i32's implementation
+///         fmt::UpperHex::fmt(&val, f) // delegate to i32's implementation
 ///     }
 /// }
 ///
@@ -869,7 +869,8 @@ pub trait UpperHex {
 ///     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
 ///         // use `as` to convert to a `*const T`, which implements Pointer, which we can use
 ///
-///         write!(f, "{:p}", self as *const Length)
+///         let ptr = self as *const Self;
+///         fmt::Pointer::fmt(&ptr, f)
 ///     }
 /// }
 ///

src/libcore/iter/traits/collect.rs

@@ -91,9 +91,9 @@
 /// ```
 #[stable(feature = "rust1", since = "1.0.0")]
 #[rustc_on_unimplemented(
-    message="a collection of type `{Self}` cannot be built from an iterator \
+    message="a value of type `{Self}` cannot be built from an iterator \
              over elements of type `{A}`",
-    label="a collection of type `{Self}` cannot be built from `std::iter::Iterator<Item={A}>`",
+    label="value of type `{Self}` cannot be built from `std::iter::Iterator<Item={A}>`",
 )]
 pub trait FromIterator<A>: Sized {
     /// Creates a value from an iterator.

src/libcore/sync/atomic.rs

@@ -27,7 +27,7 @@
 //!
 //! Atomic variables are safe to share between threads (they implement [`Sync`])
 //! but they do not themselves provide the mechanism for sharing and follow the
-//! [threading model](../../../std/thread/index.html#the-threading-model) of rust.
+//! [threading model](../../../std/thread/index.html#the-threading-model) of Rust.
 //! The most common way to share an atomic variable is to put it into an [`Arc`][arc] (an
 //! atomically-reference-counted shared pointer).
 //!

src/libpanic_unwind/gcc.rs

@@ -129,6 +129,9 @@ const UNWIND_DATA_REG: (i32, i32) = (24, 25); // I0, I1
 #[cfg(target_arch = "hexagon")]
 const UNWIND_DATA_REG: (i32, i32) = (0, 1); // R0, R1
 
+#[cfg(target_arch = "riscv64")]
+const UNWIND_DATA_REG: (i32, i32) = (10, 11); // x10, x11
+
 // The following code is based on GCC's C and C++ personality routines.  For reference, see:
 // https://github.com/gcc-mirror/gcc/blob/master/libstdc++-v3/libsupc++/eh_personality.cc
 // https://github.com/gcc-mirror/gcc/blob/trunk/libgcc/unwind-c.c

src/librustc/infer/error_reporting/mod.rs

@@ -1809,12 +1809,17 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
                             sub_region,
                             "...",
                         );
-                        err.note(&format!(
-                            "...so that the {}:\nexpected {}\n   found {}",
-                            sup_trace.cause.as_requirement_str(),
-                            sup_expected.content(),
-                            sup_found.content()
+                        err.span_note(sup_trace.cause.span, &format!(
+                            "...so that the {}",
+                            sup_trace.cause.as_requirement_str()
                         ));
+
+                        err.note_expected_found(
+                            &"",
+                            sup_expected,
+                            &"",
+                            sup_found
+                        );
                         err.emit();
                         return;
                     }

src/librustc/infer/error_reporting/note.rs

@@ -13,12 +13,20 @@ impl<'a, 'tcx> InferCtxt<'a, 'tcx> {
         match *origin {
             infer::Subtype(ref trace) => {
                 if let Some((expected, found)) = self.values_str(&trace.values) {
-                    let expected = expected.content();
-                    let found = found.content();
-                    err.note(&format!("...so that the {}:\nexpected {}\n   found {}",
-                                      trace.cause.as_requirement_str(),
-                                      expected,
-                                      found));
+                    err.span_note(
+                        trace.cause.span,
+                        &format!(
+                            "...so that the {}",
+                            trace.cause.as_requirement_str()
+                        )
+                    );
+
+                    err.note_expected_found(
+                        &"",
+                        expected,
+                        &"",
+                        found
+                    );
                 } else {
                     // FIXME: this really should be handled at some earlier stage. Our
                     // handling of region checking when type errors are present is

src/librustc/ty/print/pretty.rs

@@ -1282,6 +1282,9 @@ impl<F: fmt::Write> Printer<'tcx> for FmtPrinter<'_, 'tcx, F> {
             if !self.empty_path {
                 write!(self, "::")?;
             }
+            if ast::Ident::from_str(&name).is_raw_guess() {
+                write!(self, "r#")?;
+            }
             write!(self, "{}", name)?;
 
             // FIXME(eddyb) this will print e.g. `{{closure}}#3`, but it

src/librustc_data_structures/obligation_forest/mod.rs

@@ -130,12 +130,11 @@ type ObligationTreeIdGenerator =
 pub struct ObligationForest<O: ForestObligation> {
     /// The list of obligations. In between calls to
     /// `process_obligations`, this list only contains nodes in the
-    /// `Pending` or `Success` state (with a non-zero number of
+    /// `Pending` or `Waiting` state (with a non-zero number of
     /// incomplete children). During processing, some of those nodes
     /// may be changed to the error state, or we may find that they
-    /// are completed (That is, `num_incomplete_children` drops to 0).
-    /// At the end of processing, those nodes will be removed by a
-    /// call to `compress`.
+    /// are completed. At the end of processing, those nodes will be
+    /// removed by a call to `compress`.
     ///
     /// `usize` indices are used here and throughout this module, rather than
     /// `rustc_index::newtype_index!` indices, because this code is hot enough that the
@@ -211,28 +210,56 @@ impl<O> Node<O> {
 /// represents the current state of processing for the obligation (of
 /// type `O`) associated with this node.
 ///
-/// Outside of ObligationForest methods, nodes should be either Pending
-/// or Waiting.
+/// The non-`Error` state transitions are as follows.
+/// ```
+/// (Pre-creation)
+///  |
+///  |     register_obligation_at() (called by process_obligations() and
+///  v                               from outside the crate)
+/// Pending
+///  |
+///  |     process_obligations()
+///  v
+/// Success
+///  |  ^
+///  |  |  update_waiting_and_success_states()
+///  |  v
+///  | Waiting
+///  |
+///  |     process_cycles()
+///  v
+/// Done
+///  |
+///  |     compress()
+///  v
+/// (Removed)
+/// ```
+/// The `Error` state can be introduced in several places, via `error_at()`.
+///
+/// Outside of `ObligationForest` methods, nodes should be either `Pending` or
+/// `Waiting`.
 #[derive(Debug, Copy, Clone, PartialEq, Eq)]
 enum NodeState {
-    /// Obligations for which selection had not yet returned a
-    /// non-ambiguous result.
+    /// This obligation has not yet been selected successfully. Cannot have
+    /// subobligations.
     Pending,
 
-    /// This obligation was selected successfully, but may or
-    /// may not have subobligations.
+    /// This obligation was selected successfully, but the state of any
+    /// subobligations are current unknown. It will be converted to `Waiting`
+    /// or `Done` once the states of the subobligations become known.
     Success,
 
-    /// This obligation was selected successfully, but it has
-    /// a pending subobligation.
+    /// This obligation was selected successfully, but it has one or more
+    /// pending subobligations.
     Waiting,
 
-    /// This obligation, along with its subobligations, are complete,
-    /// and will be removed in the next collection.
+    /// This obligation was selected successfully, as were all of its
+    /// subobligations (of which there may be none). It will be removed by the
+    /// next compression step.
     Done,
 
-    /// This obligation was resolved to an error. Error nodes are
-    /// removed from the vector by the compression step.
+    /// This obligation was resolved to an error. It will be removed by the
+    /// next compression step.
     Error,
 }
 
@@ -464,7 +491,7 @@ impl<O: ForestObligation> ObligationForest<O> {
             };
         }
 
-        self.mark_as_waiting();
+        self.update_waiting_and_success_states();
         self.process_cycles(processor);
         let completed = self.compress(do_completed);
 
@@ -477,10 +504,9 @@ impl<O: ForestObligation> ObligationForest<O> {
         }
     }
 
-    /// Mark all `NodeState::Success` nodes as `NodeState::Done` and
-    /// report all cycles between them. This should be called
-    /// after `mark_as_waiting` marks all nodes with pending
-    /// subobligations as NodeState::Waiting.
+    /// Mark all `Success` nodes as `Done` and report all cycles between them.
+    /// This should be called after `update_waiting_and_success_states` updates
+    /// the status of all `Waiting` and `Success` nodes.
     fn process_cycles<P>(&self, processor: &mut P)
         where P: ObligationProcessor<Obligation=O>
     {
@@ -562,42 +588,47 @@ impl<O: ForestObligation> ObligationForest<O> {
 
     // This always-inlined function is for the hot call site.
     #[inline(always)]
-    fn inlined_mark_neighbors_as_waiting_from(&self, node: &Node<O>) {
+    fn inlined_mark_dependents_as_waiting(&self, node: &Node<O>) {
         for &index in node.dependents.iter() {
             let node = &self.nodes[index];
             match node.state.get() {
                 NodeState::Waiting | NodeState::Error => {}
                 NodeState::Success => {
                     node.state.set(NodeState::Waiting);
                     // This call site is cold.
-                    self.uninlined_mark_neighbors_as_waiting_from(node);
+                    self.uninlined_mark_dependents_as_waiting(node);
                 }
                 NodeState::Pending | NodeState::Done => {
                     // This call site is cold.
-                    self.uninlined_mark_neighbors_as_waiting_from(node);
+                    self.uninlined_mark_dependents_as_waiting(node);
                 }
             }
         }
     }
 
     // This never-inlined function is for the cold call site.
     #[inline(never)]
-    fn uninlined_mark_neighbors_as_waiting_from(&self, node: &Node<O>) {
-        self.inlined_mark_neighbors_as_waiting_from(node)
+    fn uninlined_mark_dependents_as_waiting(&self, node: &Node<O>) {
+        self.inlined_mark_dependents_as_waiting(node)
     }
 
-    /// Marks all nodes that depend on a pending node as `NodeState::Waiting`.
-    fn mark_as_waiting(&self) {
+    /// Updates the states of all `Waiting` and `Success` nodes. Upon
+    /// completion, all such nodes that depend on a pending node will be marked
+    /// as `Waiting`, and all others will be marked as `Success`.
+    fn update_waiting_and_success_states(&self) {
+        // Optimistically mark all `Waiting` nodes as `Success`.
         for node in &self.nodes {
             if node.state.get() == NodeState::Waiting {
                 node.state.set(NodeState::Success);
             }
         }
 
+        // Convert all `Success` nodes that still depend on a pending node to
+        // `Waiting`. This may undo some of the changes done in the loop above.
         for node in &self.nodes {
             if node.state.get() == NodeState::Pending {
                 // This call site is hot.
-                self.inlined_mark_neighbors_as_waiting_from(node);
+                self.inlined_mark_dependents_as_waiting(node);
             }
         }
     }

src/librustc_error_codes/error_codes.rs

@@ -347,6 +347,7 @@ E0622: include_str!("./error_codes/E0622.md"),
 E0623: include_str!("./error_codes/E0623.md"),
 E0624: include_str!("./error_codes/E0624.md"),
 E0626: include_str!("./error_codes/E0626.md"),
+E0631: include_str!("./error_codes/E0631.md"),
 E0633: include_str!("./error_codes/E0633.md"),
 E0635: include_str!("./error_codes/E0635.md"),
 E0636: include_str!("./error_codes/E0636.md"),
@@ -580,7 +581,6 @@ E0745: include_str!("./error_codes/E0745.md"),
     // rustc_const_unstable attribute must be paired with stable/unstable
     // attribute
     E0630,
-    E0631, // type mismatch in closure arguments
     E0632, // cannot provide explicit generic arguments when `impl Trait` is
            // used in argument position
     E0634, // type has conflicting packed representaton hints

src/librustc_error_codes/error_codes/E0092.md

@@ -1,4 +1,5 @@
-You tried to declare an undefined atomic operation function.
+An undefined atomic operation function was declared.
+
 Erroneous code example:
 
 ```compile_fail,E0092
@@ -11,8 +12,8 @@ extern "rust-intrinsic" {
 ```
 
 Please check you didn't make a mistake in the function's name. All intrinsic
-functions are defined in librustc_codegen_llvm/intrinsic.rs and in
-libcore/intrinsics.rs in the Rust source code. Example:
+functions are defined in `librustc_codegen_llvm/intrinsic.rs` and in
+`libcore/intrinsics.rs` in the Rust source code. Example:
 
 ```
 #![feature(intrinsics)]

src/librustc_error_codes/error_codes/E0093.md

@@ -1,4 +1,6 @@
-You declared an unknown intrinsic function. Erroneous code example:
+An unknown intrinsic function was declared.
+
+Erroneous code example:
 
 ```compile_fail,E0093
 #![feature(intrinsics)]
@@ -15,8 +17,8 @@ fn main() {
 ```
 
 Please check you didn't make a mistake in the function's name. All intrinsic
-functions are defined in librustc_codegen_llvm/intrinsic.rs and in
-libcore/intrinsics.rs in the Rust source code. Example:
+functions are defined in `librustc_codegen_llvm/intrinsic.rs` and in
+`libcore/intrinsics.rs` in the Rust source code. Example:
 
 ```
 #![feature(intrinsics)]

src/librustc_error_codes/error_codes/E0094.md

@@ -1,4 +1,5 @@
-You gave an invalid number of type parameters to an intrinsic function.
+An invalid number of type parameters was given to an intrinsic function.
+
 Erroneous code example:
 
 ```compile_fail,E0094

src/librustc_error_codes/error_codes/E0106.md

@@ -2,7 +2,7 @@ This error indicates that a lifetime is missing from a type. If it is an error
 inside a function signature, the problem may be with failing to adhere to the
 lifetime elision rules (see below).
 
-Here are some simple examples of where you'll run into this error:
+Erroneous code examples:
 
 ```compile_fail,E0106
 struct Foo1 { x: &bool }
@@ -27,7 +27,7 @@ function signatures which allows you to leave out lifetimes in certain cases.
 For more background on lifetime elision see [the book][book-le].
 
 The lifetime elision rules require that any function signature with an elided
-output lifetime must either have
+output lifetime must either have:
 
  - exactly one input lifetime
  - or, multiple input lifetimes, but the function must also be a method with a