Auto merge of #121800 - GuillaumeGomez:rollup-wob2qcz, r=GuillaumeGomez

Rollup of 10 pull requests

Successful merges:

 - #118217 (Document which methods on `f64` are precise)
 - #119748 (Increase visibility of `join_path` and `split_paths`)
 - #121412 (platform docs: clarify hexagon-unknown-none-elf example, add hexagon-unknown-linux-musl)
 - #121654 (Fix `async Fn` confirmation for `FnDef`/`FnPtr`/`Closure` types)
 - #121700 (CFI: Don't compress user-defined builtin types)
 - #121765 (add platform-specific function to get the error number for HermitOS)
 - #121781 (bootstrap/format: send larger batches to rustfmt)
 - #121788 (bootstrap: fix clap deprecated warnings)
 - #121792 (Improve renaming suggestion when item starts with underscore)
 - #121793 (Document which methods on `f32` are precise)

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

7 files changed, 142 insertions, 26 deletions

diff --git a/src/bootstrap/src/core/build_steps/format.rs b/src/bootstrap/src/core/build_steps/format.rs
index 69c8792b031..700c3ee4fda 100644
--- a/src/bootstrap/src/core/build_steps/format.rs
+++ b/src/bootstrap/src/core/build_steps/format.rs
@@ -279,8 +279,8 @@ pub fn format(build: &Builder<'_>, check: bool, paths: &[PathBuf]) {
     let thread = std::thread::spawn(move || {
         let mut children = VecDeque::new();
         while let Ok(path) = rx.recv() {
-            // try getting a few more paths from the channel to amortize the overhead of spawning processes
-            let paths: Vec<_> = rx.try_iter().take(7).chain(std::iter::once(path)).collect();
+            // try getting more paths from the channel to amortize the overhead of spawning processes
+            let paths: Vec<_> = rx.try_iter().take(63).chain(std::iter::once(path)).collect();
 
             let child = rustfmt(&src, &rustfmt_path, paths.as_slice(), check);
             children.push_back(child);
diff --git a/src/bootstrap/src/core/builder.rs b/src/bootstrap/src/core/builder.rs
index e169cba3c13..8223a80c931 100644
--- a/src/bootstrap/src/core/builder.rs
+++ b/src/bootstrap/src/core/builder.rs
@@ -642,22 +642,22 @@ impl<'a> ShouldRun<'a> {
 
 #[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, ValueEnum)]
 pub enum Kind {
-    #[clap(alias = "b")]
+    #[value(alias = "b")]
     Build,
-    #[clap(alias = "c")]
+    #[value(alias = "c")]
     Check,
     Clippy,
     Fix,
     Format,
-    #[clap(alias = "t")]
+    #[value(alias = "t")]
     Test,
     Bench,
-    #[clap(alias = "d")]
+    #[value(alias = "d")]
     Doc,
     Clean,
     Dist,
     Install,
-    #[clap(alias = "r")]
+    #[value(alias = "r")]
     Run,
     Setup,
     Suggest,
diff --git a/src/bootstrap/src/core/config/flags.rs b/src/bootstrap/src/core/config/flags.rs
index 8af454001a6..7262b785ee0 100644
--- a/src/bootstrap/src/core/config/flags.rs
+++ b/src/bootstrap/src/core/config/flags.rs
@@ -31,7 +31,7 @@ pub enum Warnings {
 
 /// Deserialized version of all flags for this compile.
 #[derive(Debug, Parser)]
-#[clap(
+#[command(
     override_usage = "x.py <subcommand> [options] [<paths>...]",
     disable_help_subcommand(true),
     about = "",
@@ -118,7 +118,7 @@ pub struct Flags {
     // This overrides the deny-warnings configuration option,
     // which passes -Dwarnings to the compiler invocations.
     #[arg(global(true), long)]
-    #[clap(value_enum, default_value_t=Warnings::Default, value_name = "deny|warn")]
+    #[arg(value_enum, default_value_t=Warnings::Default, value_name = "deny|warn")]
     /// if value is deny, will deny warnings
     /// if value is warn, will emit warnings
     /// otherwise, use the default configured behaviour
@@ -132,7 +132,7 @@ pub struct Flags {
     pub json_output: bool,
 
     #[arg(global(true), long, value_name = "STYLE")]
-    #[clap(value_enum, default_value_t = Color::Auto)]
+    #[arg(value_enum, default_value_t = Color::Auto)]
     /// whether to use color in cargo and rustc output
     pub color: Color,
 
@@ -188,7 +188,7 @@ impl Flags {
         let it = std::iter::once(&first).chain(args.iter());
         // We need to check for `<cmd> -h -v`, in which case we list the paths
         #[derive(Parser)]
-        #[clap(disable_help_flag(true))]
+        #[command(disable_help_flag(true))]
         struct HelpVerboseOnly {
             #[arg(short, long)]
             help: bool,
@@ -218,7 +218,7 @@ impl Flags {
 
 #[derive(Debug, Clone, Default, clap::Subcommand)]
 pub enum Subcommand {
-    #[clap(aliases = ["b"], long_about = "\n
+    #[command(aliases = ["b"], long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to directories to the crates
         and/or artifacts to compile. For example, for a quick build of a usable
@@ -233,7 +233,7 @@ pub enum Subcommand {
     /// Compile either the compiler or libraries
     #[default]
     Build,
-    #[clap(aliases = ["c"], long_about = "\n
+    #[command(aliases = ["c"], long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to directories to the crates
         and/or artifacts to compile. For example:
@@ -246,7 +246,7 @@ pub enum Subcommand {
         all_targets: bool,
     },
     /// Run Clippy (uses rustup/cargo-installed clippy binary)
-    #[clap(long_about = "\n
+    #[command(long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to directories to the crates
         and/or artifacts to run clippy against. For example:
@@ -273,14 +273,14 @@ pub enum Subcommand {
         forbid: Vec<String>,
     },
     /// Run cargo fix
-    #[clap(long_about = "\n
+    #[command(long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to directories to the crates
         and/or artifacts to run `cargo fix` against. For example:
             ./x.py fix library/core
             ./x.py fix library/core library/proc_macro")]
     Fix,
-    #[clap(
+    #[command(
         name = "fmt",
         long_about = "\n
     Arguments:
@@ -295,7 +295,7 @@ pub enum Subcommand {
         #[arg(long)]
         check: bool,
     },
-    #[clap(aliases = ["d"], long_about = "\n
+    #[command(aliases = ["d"], long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to directories of documentation
         to build. For example:
@@ -316,7 +316,7 @@ pub enum Subcommand {
         /// render the documentation in JSON format in addition to the usual HTML format
         json: bool,
     },
-    #[clap(aliases = ["t"], long_about = "\n
+    #[command(aliases = ["t"], long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to test directories that
         should be compiled and run. For example:
@@ -400,7 +400,7 @@ pub enum Subcommand {
     Dist,
     /// Install distribution artifacts
     Install,
-    #[clap(aliases = ["r"], long_about = "\n
+    #[command(aliases = ["r"], long_about = "\n
     Arguments:
         This subcommand accepts a number of paths to tools to build and run. For
         example:
@@ -413,7 +413,7 @@ pub enum Subcommand {
         args: Vec<String>,
     },
     /// Set up the environment for development
-    #[clap(long_about = format!(
+    #[command(long_about = format!(
         "\n
 x.py setup creates a `config.toml` which changes the defaults for x.py itself,
 as well as setting up a git pre-push hook, VS Code config and toolchain link.
@@ -434,7 +434,7 @@ Arguments:
         profile: Option<PathBuf>,
     },
     /// Suggest a subset of tests to run, based on modified files
-    #[clap(long_about = "\n")]
+    #[command(long_about = "\n")]
     Suggest {
         /// run suggested tests
         #[arg(long)]
diff --git a/src/doc/rustc/src/SUMMARY.md b/src/doc/rustc/src/SUMMARY.md
index d4ca91977a6..90ac97f35f6 100644
--- a/src/doc/rustc/src/SUMMARY.md
+++ b/src/doc/rustc/src/SUMMARY.md
@@ -39,6 +39,7 @@
     - [\*-unknown-fuchsia](platform-support/fuchsia.md)
     - [\*-kmc-solid_\*](platform-support/kmc-solid.md)
     - [csky-unknown-linux-gnuabiv2\*](platform-support/csky-unknown-linux-gnuabiv2.md)
+    - [hexagon-unknown-linux-musl](platform-support/hexagon-unknown-linux-musl.md)
     - [hexagon-unknown-none-elf](platform-support/hexagon-unknown-none-elf.md)
     - [loongarch\*-unknown-linux-\*](platform-support/loongarch-linux.md)
     - [loongarch\*-unknown-none\*](platform-support/loongarch-none.md)
diff --git a/src/doc/rustc/src/platform-support.md b/src/doc/rustc/src/platform-support.md
index 984cb13f790..f1e3ad81b85 100644
--- a/src/doc/rustc/src/platform-support.md
+++ b/src/doc/rustc/src/platform-support.md
@@ -286,8 +286,8 @@ target | std | host | notes
 `bpfel-unknown-none` | * |  | BPF (little endian)
 `csky-unknown-linux-gnuabiv2` | ✓ |  | C-SKY abiv2 Linux (little endian)
 `csky-unknown-linux-gnuabiv2hf` | ✓ |  | C-SKY abiv2 Linux, hardfloat (little endian)
-[`hexagon-unknown-none-elf`](platform-support/hexagon-unknown-none-elf.md)| * | Bare Hexagon (v60+, HVX)
-`hexagon-unknown-linux-musl` | ? |  |
+[`hexagon-unknown-none-elf`](platform-support/hexagon-unknown-none-elf.md)| * | | Bare Hexagon (v60+, HVX)
+[`hexagon-unknown-linux-musl`](platform-support/hexagon-unknown-linux-musl.md) | ✓ | | Hexagon Linux
 `i386-apple-ios` | ✓ |  | 32-bit x86 iOS [^x86_32-floats-return-ABI]
 [`i586-pc-nto-qnx700`](platform-support/nto-qnx.md) | * |  | 32-bit x86 QNX Neutrino 7.0 RTOS  [^x86_32-floats-return-ABI]
 [`i586-unknown-netbsd`](platform-support/netbsd.md) | ✓ |  | 32-bit x86, restricted to Pentium
diff --git a/src/doc/rustc/src/platform-support/hexagon-unknown-linux-musl.md b/src/doc/rustc/src/platform-support/hexagon-unknown-linux-musl.md
new file mode 100644
index 00000000000..c1372726a35
--- /dev/null
+++ b/src/doc/rustc/src/platform-support/hexagon-unknown-linux-musl.md
@@ -0,0 +1,102 @@
+# `hexagon-unknown-linux-musl`
+
+**Tier: 3**
+
+Target for cross-compiling Linux user-mode applications targeting the Hexagon
+DSP architecture.
+
+| Target                   | Descriptions                              |
+| ------------------------ | ----------------------------------------- |
+| hexagon-unknown-linux-musl | Hexagon 32-bit Linux |
+
+## Target maintainers
+
+- [Brian Cain](https://github.com/androm3da), `bcain@quicinc.com`
+
+## Requirements
+The target is cross-compiled. This target supports `std`.  By default, code
+generated with this target should run on Hexagon DSP hardware.
+
+- `-Ctarget-cpu=hexagonv73` adds support for instructions defined up to Hexagon V73.
+
+Binaries can be run using QEMU user emulation. On Debian-based systems, it should be
+sufficient to install the package `qemu-user-static` to be able to run simple static
+binaries:
+
+```text
+# apt install qemu-user-static
+# qemu-hexagon-static ./hello
+```
+
+In order to build linux programs with Rust, you will require a linker capable
+of targeting hexagon.  You can use `clang`/`lld` from the [hexagon toolchain
+using exclusively public open source repos](https://github.com/quic/toolchain_for_hexagon/releases).
+
+Also included in that toolchain is the C library that can be used when creating
+dynamically linked executables.
+
+```text
+# /opt/clang+llvm-18.1.0-cross-hexagon-unknown-linux-musl/x86_64-linux-gnu/bin/qemu-hexagon -L /opt/clang+llvm-18.1.0-cross-hexagon-unknown-linux-musl/x86_64-linux-gnu/target/hexagon-unknown-linux-musl/usr/ ./hello
+```
+
+## Building the target
+Because it is Tier 3, rust does not yet ship pre-compiled artifacts for this
+target.
+
+Therefore, you can build Rust with support for the target by adding it to the
+target list in `config.toml`, a sample configuration is shown below.
+
+```toml
+[build]
+target = [ "hexagon-unknown-linux-musl"]
+
+[target.hexagon-unknown-linux-musl]
+
+cc = "hexagon-unknown-linux-musl-clang"
+cxx = "hexagon-unknown-linux-musl-clang++"
+linker = "hexagon-unknown-linux-musl-clang"
+ar = "hexagon-unknown-linux-musl-ar"
+ranlib = "hexagon-unknown-linux-musl-ranlib"
+musl-root = "/opt/clang+llvm-18.1.0-cross-hexagon-unknown-linux-musl/x86_64-linux-gnu/target/hexagon-unknown-linux-musl/usr"
+llvm-libunwind = 'in-tree'
+qemu-rootfs = "/opt/clang+llvm-18.1.0-cross-hexagon-unknown-linux-musl/x86_64-linux-gnu/target/hexagon-unknown-linux-musl/usr"
+```
+
+
+## Testing
+
+Currently there is no support to run the rustc test suite for this target.
+
+
+## Building Rust programs
+
+Download and install the hexagon open source toolchain from https://github.com/quic/toolchain_for_hexagon/releases
+
+The following `.cargo/config` is needed inside any project directory to build
+for the Hexagon Linux target:
+
+```toml
+[build]
+target = "hexagon-unknown-linux-musl"
+
+[target.hexagon-unknown-linux-musl]
+linker = "hexagon-unknown-linux-musl-clang"
+ar = "hexagon-unknown-linux-musl-ar"
+runner = "qemu-hexagon -L /opt/clang+llvm-18.1.0-cross-hexagon-unknown-linux-musl/x86_64-linux-gnu/target/hexagon-unknown-linux-musl/usr"
+```
+
+Edit the "runner" in `.cargo/config` to point to the path to your toolchain's
+C library.
+
+```text
+...
+runner = "qemu-hexagon -L /path/to/my/inst/clang+llvm-18.1.0-cross-hexagon-unknown-linux-musl/x86_64-linux-gnu/target/hexagon-unknown-linux-musl/usr"
+...
+```
+
+Build/run your rust program with `qemu-hexagon` in your `PATH`:
+
+```text
+export PATH=/path/to/my/inst/clang+llvm-18.1.0-cross-hexagon-unknown-linux-musl/x86_64-linux-gnu/bin/:$PATH
+cargo run -Zbuild-std -Zbuild-std-features=llvm-libunwind
+```
diff --git a/src/doc/rustc/src/platform-support/hexagon-unknown-none-elf.md b/src/doc/rustc/src/platform-support/hexagon-unknown-none-elf.md
index 3ac1d2c2460..a0e26b798ac 100644
--- a/src/doc/rustc/src/platform-support/hexagon-unknown-none-elf.md
+++ b/src/doc/rustc/src/platform-support/hexagon-unknown-none-elf.md
@@ -41,6 +41,8 @@ target = ["<target for your host>", "hexagon-unknown-none-elf"]
 cc = "hexagon-unknown-none-elf-clang"
 cxx = "hexagon-unknown-none-elf-clang++"
 linker = "hexagon-unknown-none-elf-clang"
+ranlib = "hexagon-unknown-none-elf-ranlib"
+ar = "hexagon-unknown-none-elf-ar"
 llvm-libunwind = 'in-tree'
 ```
 
@@ -142,7 +144,7 @@ ${cc} --target=hexagon-unknown-none-elf -o testit \
     ${g0_lib_path}/init.o \
     -L${sdk_libs}/${q6_arch}/ \
     -L${sdk_libs}/ \
-    testit.c \
+    wrap.c \
     target/hexagon-unknown-none-elf/${build_cfg}/libdemo1_hexagon.rlib \
     target/hexagon-unknown-none-elf/${build_cfg}/deps/libcore-*.rlib \
     target/hexagon-unknown-none-elf/${build_cfg}/deps/libcompiler_builtins-*.rlib \
@@ -217,7 +219,18 @@ fn rust_eh_personality() {}
 
 ```
 
-Next, save the script below as `build.sh` and edit it to suit your
+Next, create a C program as an entry point, save the content below as
+`wrap.c`:
+
+```C
+int hello();
+
+int main() {
+    hello();
+}
+```
+
+Then, save the script below as `build.sh` and edit it to suit your
 environment.  The script below will build a shared object against the QuRT
 RTOS which is suitable for emulation or on-device testing when loaded via
 the fastrpc-shell.
@@ -248,7 +261,7 @@ ${cc} --target=hexagon-unknown-none-elf -o testit.so \
       -Wl,--wrap=realloc \
       -Wl,--wrap=memalign \
     -m${q6_arch} \
-    testit.c \
+    wrap.c \
     target/hexagon-unknown-none-elf/${build_cfg}/libdemo2_hexagon.rlib \
     target/hexagon-unknown-none-elf/${build_cfg}/deps/libcore-*.rlib \
     target/hexagon-unknown-none-elf/${build_cfg}/deps/libcompiler_builtins-*.rlib \