Merging upstream version 1.66.0+dfsg1.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 44 insertions, 79 deletions

diff --git a/src/doc/unstable-book/src/compiler-flags/dylib-lto.md b/src/doc/unstable-book/src/compiler-flags/dylib-lto.md
new file mode 100644
index 000000000..f69ea334f
--- /dev/null
+++ b/src/doc/unstable-book/src/compiler-flags/dylib-lto.md
@@ -0,0 +1,4 @@
+## `dylib-lto`
+
+This option enables using LTO for the `dylib` crate type. This is currently only used for compiling
+`rustc` itself (more specifically, the `librustc_driver` dylib).
diff --git a/src/doc/unstable-book/src/compiler-flags/self-profile-events.md b/src/doc/unstable-book/src/compiler-flags/self-profile-events.md
index 3ce18743b..3e644f786 100644
--- a/src/doc/unstable-book/src/compiler-flags/self-profile-events.md
+++ b/src/doc/unstable-book/src/compiler-flags/self-profile-events.md
@@ -41,7 +41,7 @@ $ rustc -Zself-profile -Zself-profile-events=default,args
 
 - `llvm`
   - Adds tracing information about LLVM passes and codegeneration.
-  - Disabled by default because this only works when `-Znew-llvm-pass-manager` is enabled.
+  - Disabled by default because this significantly increases the trace file size.
 
 ## Event synonyms
 
diff --git a/src/doc/unstable-book/src/language-features/arbitrary-enum-discriminant.md b/src/doc/unstable-book/src/language-features/arbitrary-enum-discriminant.md
deleted file mode 100644
index e0bb78227..000000000
--- a/src/doc/unstable-book/src/language-features/arbitrary-enum-discriminant.md
+++ /dev/null
@@ -1,37 +0,0 @@
-# `arbitrary_enum_discriminant`
-
-The tracking issue for this feature is: [#60553]
-
-[#60553]: https://github.com/rust-lang/rust/issues/60553
-
-------------------------
-
-The `arbitrary_enum_discriminant` feature permits tuple-like and
-struct-like enum variants with `#[repr(<int-type>)]` to have explicit discriminants.
-
-## Examples
-
-```rust
-#![feature(arbitrary_enum_discriminant)]
-
-#[allow(dead_code)]
-#[repr(u8)]
-enum Enum {
-    Unit = 3,
-    Tuple(u16) = 2,
-    Struct {
-        a: u8,
-        b: u16,
-    } = 1,
-}
-
-impl Enum {
-    fn tag(&self) -> u8 {
-        unsafe { *(self as *const Self as *const u8) }
-    }
-}
-
-assert_eq!(3, Enum::Unit.tag());
-assert_eq!(2, Enum::Tuple(5).tag());
-assert_eq!(1, Enum::Struct{a: 7, b: 11}.tag());
-```
diff --git a/src/doc/unstable-book/src/language-features/asm-sym.md b/src/doc/unstable-book/src/language-features/asm-sym.md
deleted file mode 100644
index 103d91caf..000000000
--- a/src/doc/unstable-book/src/language-features/asm-sym.md
+++ /dev/null
@@ -1,13 +0,0 @@
-# `asm_sym`
-
-The tracking issue for this feature is: [#93333]
-
-[#93333]: https://github.com/rust-lang/rust/issues/93333
-
-------------------------
-
-This feature adds a `sym <path>` operand type to `asm!` and `global_asm!`.
-- `<path>` must refer to a `fn` or `static`.
-- A mangled symbol name referring to the item is substituted into the asm template string.
-- The substituted string does not include any modifiers (e.g. GOT, PLT, relocations, etc).
-- `<path>` is allowed to point to a `#[thread_local]` static, in which case the asm code can combine the symbol with relocations (e.g. `@plt`, `@TPOFF`) to read from thread-local data.
diff --git a/src/doc/unstable-book/src/language-features/half-open-range-patterns-in-slices.md b/src/doc/unstable-book/src/language-features/half-open-range-patterns-in-slices.md
new file mode 100644
index 000000000..56a1a97df
--- /dev/null
+++ b/src/doc/unstable-book/src/language-features/half-open-range-patterns-in-slices.md
@@ -0,0 +1,30 @@
+# `half_open_range_patterns_in_slices`
+
+The tracking issue for this feature is: [#67264]
+It is part of the `exclusive_range_pattern` feature,
+tracked at [#37854].
+
+[#67264]: https://github.com/rust-lang/rust/issues/67264
+[#37854]: https://github.com/rust-lang/rust/issues/37854
+-----
+
+This feature allow using top-level half-open range patterns in slices.
+
+```rust
+#![feature(half_open_range_patterns_in_slices)]
+#![feature(exclusive_range_pattern)]
+
+fn main() {
+    let xs = [13, 1, 5, 2, 3, 1, 21, 8];
+    let [a @ 3.., b @ ..3, c @ 4..6, ..] = xs else { return; };
+}
+```
+
+Note that this feature is not required if the patterns are wrapped between parenthesis.
+
+```rust
+fn main() {
+    let xs = [13, 1];
+    let [(a @ 3..), c] = xs else { return; };
+}
+```
diff --git a/src/doc/unstable-book/src/language-features/half-open-range-patterns.md b/src/doc/unstable-book/src/language-features/half-open-range-patterns.md
deleted file mode 100644
index 3b16dd049..000000000
--- a/src/doc/unstable-book/src/language-features/half-open-range-patterns.md
+++ /dev/null
@@ -1,27 +0,0 @@
-# `half_open_range_patterns`
-
-The tracking issue for this feature is: [#67264]
-It is part of the `#![exclusive_range_pattern]` feature,
-tracked at [#37854].
-
-[#67264]: https://github.com/rust-lang/rust/issues/67264
-[#37854]: https://github.com/rust-lang/rust/issues/37854
------
-
-The `half_open_range_patterns` feature allows RangeTo patterns
-(`..10`) to be used in appropriate pattern matching contexts.
-This requires also enabling the `exclusive_range_pattern` feature.
-
-It also enabled RangeFrom patterns but that has since been
-stabilized.
-
-```rust
-#![feature(half_open_range_patterns)]
-#![feature(exclusive_range_pattern)]
-    let x = 5;
-    match x {
-        ..0 => println!("negative!"), // "RangeTo" pattern. Unstable.
-        0 => println!("zero!"),
-        1.. => println!("positive!"), // "RangeFrom" pattern. Stable.
-    }
-```
diff --git a/src/doc/unstable-book/src/language-features/unix-sigpipe.md b/src/doc/unstable-book/src/language-features/unix-sigpipe.md
index aa39b6eb2..7ed6a7de8 100644
--- a/src/doc/unstable-book/src/language-features/unix-sigpipe.md
+++ b/src/doc/unstable-book/src/language-features/unix-sigpipe.md
@@ -36,7 +36,7 @@ hello world
 
 Set the `SIGPIPE` handler to `SIG_IGN` before invoking `fn main()`. This will result in `ErrorKind::BrokenPipe` errors if you program tries to write to a closed pipe. This is normally what you want if you for example write socket servers, socket clients, or pipe peers.
 
-This is what libstd has done by default since 2014. Omitting `#[unix_sigpipe = "..."]` is the same as having `#[unix_sigpipe = "sig_ign"]`.
+This is what libstd has done by default since 2014. (However, see the note on child processes below.)
 
 ### Example
 
@@ -52,3 +52,11 @@ hello world
 thread 'main' panicked at 'failed printing to stdout: Broken pipe (os error 32)', library/std/src/io/stdio.rs:1016:9
 note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace
 ```
+
+### Note on child processes
+
+When spawning child processes, the legacy Rust behavior if `#[unix_sigpipe]` is not specified is to
+reset `SIGPIPE` to `SIG_DFL`.
+
+If `#[unix_sigpipe = "..."]` is specified, no matter what its value is, the signal disposition of
+`SIGPIPE` is no longer reset. This means that the child inherits the parent's `SIGPIPE` behavior.