Rollup merge of rust-lang#124788 - madsmtm:reduce-target_os-macos, r=workingjubilee

Convert instances of `target_os = "macos"` to `target_vendor = "apple"`

rust-lang#124491 migrated towards using `target_vendor = "apple"` more, as there's very little difference between iOS, tvOS, watchOS and visionOS. In that PR, I only did the changes where the standard library already had fixes for iOS, that I could confidently apply to the other targets.

However, there's actually also not that big of a gap between macOS and the aforementioned platforms - so in this PR, I've gone through a few of the instances of `target_os = "macos"` and replaced it with `target_vendor = "apple"` to improve support on those platforms, see the commits for details.

r? workingjubilee

CC `@thomcc` `@simlay` (do tell me if I should stop pinging you on these Apple PRs)

`@rustbot` label O-apple

Author: workingjubilee

library/std/src/os/unix/net/listener.rs

@@ -81,21 +81,25 @@ impl UnixListener {
             ))]
             const backlog: core::ffi::c_int = 128;
             #[cfg(any(
+                // Silently capped to `/proc/sys/net/core/somaxconn`.
                 target_os = "linux",
+                // Silently capped to `kern.ipc.soacceptqueue`.
                 target_os = "freebsd",
+                // Silently capped to `kern.somaxconn sysctl`.
                 target_os = "openbsd",
-                target_os = "macos"
+                // Silently capped to the default 128.
+                target_vendor = "apple",
             ))]
             const backlog: core::ffi::c_int = -1;
             #[cfg(not(any(
                 target_os = "windows",
                 target_os = "redox",
+                target_os = "espidf",
+                target_os = "horizon",
                 target_os = "linux",
                 target_os = "freebsd",
                 target_os = "openbsd",
-                target_os = "macos",
-                target_os = "espidf",
-                target_os = "horizon"
+                target_vendor = "apple",
             )))]
             const backlog: libc::c_int = libc::SOMAXCONN;
 

library/std/src/sys/pal/unix/alloc.rs

@@ -13,7 +13,13 @@ unsafe impl GlobalAlloc for System {
         if layout.align() <= MIN_ALIGN && layout.align() <= layout.size() {
             libc::malloc(layout.size()) as *mut u8
         } else {
-            #[cfg(target_os = "macos")]
+            // `posix_memalign` returns a non-aligned value if supplied a very
+            // large alignment on older versions of Apple's platforms (unknown
+            // exactly which version range, but the issue is definitely
+            // present in macOS 10.14 and iOS 13.3).
+            //
+            // <https://github.com/rust-lang/rust/issues/30170>
+            #[cfg(target_vendor = "apple")]
             {
                 if layout.align() > (1 << 31) {
                     return ptr::null_mut();

library/std/src/sys/pal/unix/fd.rs

@@ -33,14 +33,15 @@ pub struct FileDesc(OwnedFd);
 // with the man page quoting that if the count of bytes to read is
 // greater than `SSIZE_MAX` the result is "unspecified".
 //
-// On macOS, however, apparently the 64-bit libc is either buggy or
+// On Apple targets however, apparently the 64-bit libc is either buggy or
 // intentionally showing odd behavior by rejecting any read with a size
 // larger than or equal to INT_MAX. To handle both of these the read
 // size is capped on both platforms.
-#[cfg(target_os = "macos")]
-const READ_LIMIT: usize = libc::c_int::MAX as usize - 1;
-#[cfg(not(target_os = "macos"))]
-const READ_LIMIT: usize = libc::ssize_t::MAX as usize;
+const READ_LIMIT: usize = if cfg!(target_vendor = "apple") {
+    libc::c_int::MAX as usize - 1
+} else {
+    libc::ssize_t::MAX as usize
+};
 
 #[cfg(any(
     target_os = "dragonfly",

library/std/src/sys/pal/unix/fs.rs

@@ -1493,11 +1493,11 @@ impl fmt::Debug for File {
             readlink(&p).ok()
         }
 
-        #[cfg(target_os = "macos")]
+        #[cfg(target_vendor = "apple")]
         fn get_path(fd: c_int) -> Option<PathBuf> {
             // FIXME: The use of PATH_MAX is generally not encouraged, but it
-            // is inevitable in this case because macOS defines `fcntl` with
-            // `F_GETPATH` in terms of `MAXPATHLEN`, and there are no
+            // is inevitable in this case because Apple targets define `fcntl`
+            // with `F_GETPATH` in terms of `MAXPATHLEN`, and there are no
             // alternatives. If a better method is invented, it should be used
             // instead.
             let mut buf = vec![0; libc::PATH_MAX as usize];
@@ -1538,12 +1538,12 @@ impl fmt::Debug for File {
 
         #[cfg(not(any(
             target_os = "linux",
-            target_os = "macos",
             target_os = "vxworks",
             all(target_os = "freebsd", target_arch = "x86_64"),
             target_os = "netbsd",
             target_os = "illumos",
-            target_os = "solaris"
+            target_os = "solaris",
+            target_vendor = "apple",
         )))]
         fn get_path(_fd: c_int) -> Option<PathBuf> {
             // FIXME(#24570): implement this for other Unix platforms
@@ -1552,12 +1552,12 @@ impl fmt::Debug for File {
 
         #[cfg(any(
             target_os = "linux",
-            target_os = "macos",
             target_os = "freebsd",
             target_os = "hurd",
             target_os = "netbsd",
             target_os = "openbsd",
-            target_os = "vxworks"
+            target_os = "vxworks",
+            target_vendor = "apple",
         ))]
         fn get_mode(fd: c_int) -> Option<(bool, bool)> {
             let mode = unsafe { libc::fcntl(fd, libc::F_GETFL) };
@@ -1574,12 +1574,12 @@ impl fmt::Debug for File {
 
         #[cfg(not(any(
             target_os = "linux",
-            target_os = "macos",
             target_os = "freebsd",
             target_os = "hurd",
             target_os = "netbsd",
             target_os = "openbsd",
-            target_os = "vxworks"
+            target_os = "vxworks",
+            target_vendor = "apple",
         )))]
         fn get_mode(_fd: c_int) -> Option<(bool, bool)> {
             // FIXME(#24570): implement this for other Unix platforms

library/std/src/sys/pal/unix/mod.rs

@@ -63,11 +63,11 @@ pub unsafe fn init(argc: isize, argv: *const *const u8, sigpipe: u8) {
     args::init(argc, argv);
 
     // Normally, `thread::spawn` will call `Thread::set_name` but since this thread
-    // already exists, we have to call it ourselves. We only do this on macos
+    // already exists, we have to call it ourselves. We only do this on Apple targets
     // because some unix-like operating systems such as Linux share process-id and
     // thread-id for the main thread and so renaming the main thread will rename the
     // process and we only want to enable this on platforms we've tested.
-    if cfg!(target_os = "macos") {
+    if cfg!(target_vendor = "apple") {
         thread::Thread::set_name(&c"main");
     }