Auto merge of #86527 - JohnTitor:rollup-cbu78g4, r=JohnTitor

Rollup of 11 pull requests

Successful merges:

 - #85054 (Revert SGX inline asm syntax)
 - #85182 (Move `available_concurrency` implementation to `sys`)
 - #86037 (Add `io::Cursor::{remaining, remaining_slice, is_empty}`)
 - #86114 (Reopen #79692 (Format symbols under shared frames))
 - #86297 (Allow to pass arguments to rustdoc-gui tool)
 - #86334 (Resolve type aliases to the type they point to in intra-doc links)
 - #86367 (Fix comment about rustc_inherit_overflow_checks in abs().)
 - #86381 (Add regression test for issue #39161)
 - #86387 (Remove `#[allow(unused_lifetimes)]` which is now unnecessary)
 - #86398 (Add regression test for issue #54685)
 - #86493 (Say "this enum variant takes"/"this struct takes" instead of "this function takes")

Failed merges:

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

2 files changed, 37 insertions, 162 deletions

diff --git a/library/std/src/thread/available_concurrency.rs b/library/std/src/thread/available_concurrency.rs
deleted file mode 100644
index e8cdde88014..00000000000
--- a/library/std/src/thread/available_concurrency.rs
+++ /dev/null
@@ -1,156 +0,0 @@
-use crate::io;
-use crate::num::NonZeroUsize;
-
-/// Returns the number of hardware threads available to the program.
-///
-/// This value should be considered only a hint.
-///
-/// # Platform-specific behavior
-///
-/// If interpreted as the number of actual hardware threads, it may undercount on
-/// Windows systems with more than 64 hardware threads. If interpreted as the
-/// available concurrency for that process, it may overcount on Windows systems
-/// when limited by a process wide affinity mask or job object limitations, and
-/// it may overcount on Linux systems when limited by a process wide affinity
-/// mask or affected by cgroups limits.
-///
-/// # Errors
-///
-/// This function will return an error in the following situations, but is not
-/// limited to just these cases:
-///
-/// - If the number of hardware threads is not known for the target platform.
-/// - The process lacks permissions to view the number of hardware threads
-///   available.
-///
-/// # Examples
-///
-/// ```
-/// # #![allow(dead_code)]
-/// #![feature(available_concurrency)]
-/// use std::thread;
-///
-/// let count = thread::available_concurrency().map(|n| n.get()).unwrap_or(1);
-/// ```
-#[unstable(feature = "available_concurrency", issue = "74479")]
-pub fn available_concurrency() -> io::Result<NonZeroUsize> {
-    available_concurrency_internal()
-}
-
-cfg_if::cfg_if! {
-    if #[cfg(windows)] {
-        #[allow(nonstandard_style)]
-        fn available_concurrency_internal() -> io::Result<NonZeroUsize> {
-            #[repr(C)]
-            struct SYSTEM_INFO {
-                wProcessorArchitecture: u16,
-                wReserved: u16,
-                dwPageSize: u32,
-                lpMinimumApplicationAddress: *mut u8,
-                lpMaximumApplicationAddress: *mut u8,
-                dwActiveProcessorMask: *mut u8,
-                dwNumberOfProcessors: u32,
-                dwProcessorType: u32,
-                dwAllocationGranularity: u32,
-                wProcessorLevel: u16,
-                wProcessorRevision: u16,
-            }
-            extern "system" {
-                fn GetSystemInfo(info: *mut SYSTEM_INFO) -> i32;
-            }
-            let res = unsafe {
-                let mut sysinfo = crate::mem::zeroed();
-                GetSystemInfo(&mut sysinfo);
-                sysinfo.dwNumberOfProcessors as usize
-            };
-            match res {
-                0 => Err(io::Error::new_const(io::ErrorKind::NotFound, &"The number of hardware threads is not known for the target platform")),
-                cpus => Ok(unsafe { NonZeroUsize::new_unchecked(cpus) }),
-            }
-        }
-    } else if #[cfg(any(
-        target_os = "android",
-        target_os = "emscripten",
-        target_os = "fuchsia",
-        target_os = "ios",
-        target_os = "linux",
-        target_os = "macos",
-        target_os = "solaris",
-        target_os = "illumos",
-    ))] {
-        fn available_concurrency_internal() -> io::Result<NonZeroUsize> {
-            match unsafe { libc::sysconf(libc::_SC_NPROCESSORS_ONLN) } {
-                -1 => Err(io::Error::last_os_error()),
-                0 => Err(io::Error::new_const(io::ErrorKind::NotFound, &"The number of hardware threads is not known for the target platform")),
-                cpus => Ok(unsafe { NonZeroUsize::new_unchecked(cpus as usize) }),
-            }
-        }
-    } else if #[cfg(any(target_os = "freebsd", target_os = "dragonfly", target_os = "netbsd"))] {
-        fn available_concurrency_internal() -> io::Result<NonZeroUsize> {
-            use crate::ptr;
-
-            let mut cpus: libc::c_uint = 0;
-            let mut cpus_size = crate::mem::size_of_val(&cpus);
-
-            unsafe {
-                cpus = libc::sysconf(libc::_SC_NPROCESSORS_ONLN) as libc::c_uint;
-            }
-
-            // Fallback approach in case of errors or no hardware threads.
-            if cpus < 1 {
-                let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
-                let res = unsafe {
-                    libc::sysctl(
-                        mib.as_mut_ptr(),
-                        2,
-                        &mut cpus as *mut _ as *mut _,
-                        &mut cpus_size as *mut _ as *mut _,
-                        ptr::null_mut(),
-                        0,
-                    )
-                };
-
-                // Handle errors if any.
-                if res == -1 {
-                    return Err(io::Error::last_os_error());
-                } else if cpus == 0 {
-                    return Err(io::Error::new_const(io::ErrorKind::NotFound, &"The number of hardware threads is not known for the target platform"));
-                }
-            }
-            Ok(unsafe { NonZeroUsize::new_unchecked(cpus as usize) })
-        }
-    } else if #[cfg(target_os = "openbsd")] {
-        fn available_concurrency_internal() -> io::Result<NonZeroUsize> {
-            use crate::ptr;
-
-            let mut cpus: libc::c_uint = 0;
-            let mut cpus_size = crate::mem::size_of_val(&cpus);
-            let mut mib = [libc::CTL_HW, libc::HW_NCPU, 0, 0];
-
-            let res = unsafe {
-                libc::sysctl(
-                    mib.as_mut_ptr(),
-                    2,
-                    &mut cpus as *mut _ as *mut _,
-                    &mut cpus_size as *mut _ as *mut _,
-                    ptr::null_mut(),
-                    0,
-                )
-            };
-
-            // Handle errors if any.
-            if res == -1 {
-                return Err(io::Error::last_os_error());
-            } else if cpus == 0 {
-                return Err(io::Error::new_const(io::ErrorKind::NotFound, &"The number of hardware threads is not known for the target platform"));
-            }
-
-            Ok(unsafe { NonZeroUsize::new_unchecked(cpus as usize) })
-        }
-    } else {
-        // FIXME: implement on vxWorks, Redox, HermitCore, Haiku, l4re
-        fn available_concurrency_internal() -> io::Result<NonZeroUsize> {
-            Err(io::Error::new_const(io::ErrorKind::NotFound, &"The number of hardware threads is not known for the target platform"))
-        }
-    }
-}
diff --git a/library/std/src/thread/mod.rs b/library/std/src/thread/mod.rs
index 30d8c2a1b6f..f7e79141903 100644
--- a/library/std/src/thread/mod.rs
+++ b/library/std/src/thread/mod.rs
@@ -155,6 +155,7 @@ use crate::fmt;
 use crate::io;
 use crate::mem;
 use crate::num::NonZeroU64;
+use crate::num::NonZeroUsize;
 use crate::panic;
 use crate::panicking;
 use crate::str;
@@ -174,15 +175,9 @@ use crate::time::Duration;
 #[macro_use]
 mod local;
 
-#[unstable(feature = "available_concurrency", issue = "74479")]
-mod available_concurrency;
-
 #[stable(feature = "rust1", since = "1.0.0")]
 pub use self::local::{AccessError, LocalKey};
 
-#[unstable(feature = "available_concurrency", issue = "74479")]
-pub use available_concurrency::available_concurrency;
-
 // The types used by the thread_local! macro to access TLS keys. Note that there
 // are two types, the "OS" type and the "fast" type. The OS thread local key
 // type is accessed via platform-specific API calls and is slow, while the fast
@@ -1422,3 +1417,39 @@ fn _assert_sync_and_send() {
     _assert_both::<JoinHandle<()>>();
     _assert_both::<Thread>();
 }
+
+/// Returns the number of hardware threads available to the program.
+///
+/// This value should be considered only a hint.
+///
+/// # Platform-specific behavior
+///
+/// If interpreted as the number of actual hardware threads, it may undercount on
+/// Windows systems with more than 64 hardware threads. If interpreted as the
+/// available concurrency for that process, it may overcount on Windows systems
+/// when limited by a process wide affinity mask or job object limitations, and
+/// it may overcount on Linux systems when limited by a process wide affinity
+/// mask or affected by cgroups limits.
+///
+/// # Errors
+///
+/// This function will return an error in the following situations, but is not
+/// limited to just these cases:
+///
+/// - If the number of hardware threads is not known for the target platform.
+/// - The process lacks permissions to view the number of hardware threads
+///   available.
+///
+/// # Examples
+///
+/// ```
+/// # #![allow(dead_code)]
+/// #![feature(available_concurrency)]
+/// use std::thread;
+///
+/// let count = thread::available_concurrency().map(|n| n.get()).unwrap_or(1);
+/// ```
+#[unstable(feature = "available_concurrency", issue = "74479")]
+pub fn available_concurrency() -> io::Result<NonZeroUsize> {
+    imp::available_concurrency()
+}