Rollup merge of #130595 - no1wudi:master, r=ibraheemdev

Initial std library support for NuttX

This PR add the initial libstd support for NuttX platform (Tier 3), currently it depends on https://github.com/rust-lang/libc/pull/3909 which provide the essential libc definitions.

11 files changed, 88 insertions, 21 deletions

diff --git a/library/std/src/sys/pal/unix/args.rs b/library/std/src/sys/pal/unix/args.rs
index a943e3a581a..8438a61e90f 100644
--- a/library/std/src/sys/pal/unix/args.rs
+++ b/library/std/src/sys/pal/unix/args.rs
@@ -113,6 +113,7 @@ impl DoubleEndedIterator for Args {
     target_os = "nto",
     target_os = "hurd",
     target_os = "rtems",
+    target_os = "nuttx",
 ))]
 mod imp {
     use crate::ffi::c_char;
diff --git a/library/std/src/sys/pal/unix/env.rs b/library/std/src/sys/pal/unix/env.rs
index b2d399b8791..2aee0b5d460 100644
--- a/library/std/src/sys/pal/unix/env.rs
+++ b/library/std/src/sys/pal/unix/env.rs
@@ -283,3 +283,14 @@ pub mod os {
     pub const EXE_SUFFIX: &str = "";
     pub const EXE_EXTENSION: &str = "";
 }
+
+#[cfg(target_os = "nuttx")]
+pub mod os {
+    pub const FAMILY: &str = "unix";
+    pub const OS: &str = "nuttx";
+    pub const DLL_PREFIX: &str = "lib";
+    pub const DLL_SUFFIX: &str = ".so";
+    pub const DLL_EXTENSION: &str = "so";
+    pub const EXE_SUFFIX: &str = "";
+    pub const EXE_EXTENSION: &str = "";
+}
diff --git a/library/std/src/sys/pal/unix/fd.rs b/library/std/src/sys/pal/unix/fd.rs
index 135042779ad..6a28799ca55 100644
--- a/library/std/src/sys/pal/unix/fd.rs
+++ b/library/std/src/sys/pal/unix/fd.rs
@@ -98,7 +98,12 @@ impl FileDesc {
         Ok(ret as usize)
     }
 
-    #[cfg(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita")))]
+    #[cfg(not(any(
+        target_os = "espidf",
+        target_os = "horizon",
+        target_os = "vita",
+        target_os = "nuttx"
+    )))]
     pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         let ret = cvt(unsafe {
             libc::readv(
@@ -110,14 +115,24 @@ impl FileDesc {
         Ok(ret as usize)
     }
 
-    #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))]
+    #[cfg(any(
+        target_os = "espidf",
+        target_os = "horizon",
+        target_os = "vita",
+        target_os = "nuttx"
+    ))]
     pub fn read_vectored(&self, bufs: &mut [IoSliceMut<'_>]) -> io::Result<usize> {
         io::default_read_vectored(|b| self.read(b), bufs)
     }
 
     #[inline]
     pub fn is_read_vectored(&self) -> bool {
-        cfg!(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita")))
+        cfg!(not(any(
+            target_os = "espidf",
+            target_os = "horizon",
+            target_os = "vita",
+            target_os = "nuttx"
+        )))
     }
 
     pub fn read_to_end(&self, buf: &mut Vec<u8>) -> io::Result<usize> {
@@ -297,7 +312,12 @@ impl FileDesc {
         Ok(ret as usize)
     }
 
-    #[cfg(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita")))]
+    #[cfg(not(any(
+        target_os = "espidf",
+        target_os = "horizon",
+        target_os = "vita",
+        target_os = "nuttx"
+    )))]
     pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         let ret = cvt(unsafe {
             libc::writev(
@@ -309,14 +329,24 @@ impl FileDesc {
         Ok(ret as usize)
     }
 
-    #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))]
+    #[cfg(any(
+        target_os = "espidf",
+        target_os = "horizon",
+        target_os = "vita",
+        target_os = "nuttx"
+    ))]
     pub fn write_vectored(&self, bufs: &[IoSlice<'_>]) -> io::Result<usize> {
         io::default_write_vectored(|b| self.write(b), bufs)
     }
 
     #[inline]
     pub fn is_write_vectored(&self) -> bool {
-        cfg!(not(any(target_os = "espidf", target_os = "horizon", target_os = "vita")))
+        cfg!(not(any(
+            target_os = "espidf",
+            target_os = "horizon",
+            target_os = "vita",
+            target_os = "nuttx"
+        )))
     }
 
     #[cfg_attr(target_os = "vxworks", allow(unused_unsafe))]
diff --git a/library/std/src/sys/pal/unix/fs.rs b/library/std/src/sys/pal/unix/fs.rs
index dade6d6bbae..86342c2add0 100644
--- a/library/std/src/sys/pal/unix/fs.rs
+++ b/library/std/src/sys/pal/unix/fs.rs
@@ -479,6 +479,7 @@ impl FileAttr {
         target_os = "vita",
         target_os = "hurd",
         target_os = "rtems",
+        target_os = "nuttx",
     )))]
     pub fn modified(&self) -> io::Result<SystemTime> {
         #[cfg(target_pointer_width = "32")]
@@ -501,7 +502,7 @@ impl FileAttr {
         SystemTime::new(self.stat.st_mtime as i64, 0)
     }
 
-    #[cfg(any(target_os = "horizon", target_os = "hurd"))]
+    #[cfg(any(target_os = "horizon", target_os = "hurd", target_os = "nuttx"))]
     pub fn modified(&self) -> io::Result<SystemTime> {
         SystemTime::new(self.stat.st_mtim.tv_sec as i64, self.stat.st_mtim.tv_nsec as i64)
     }
@@ -513,6 +514,7 @@ impl FileAttr {
         target_os = "vita",
         target_os = "hurd",
         target_os = "rtems",
+        target_os = "nuttx",
     )))]
     pub fn accessed(&self) -> io::Result<SystemTime> {
         #[cfg(target_pointer_width = "32")]
@@ -535,7 +537,7 @@ impl FileAttr {
         SystemTime::new(self.stat.st_atime as i64, 0)
     }
 
-    #[cfg(any(target_os = "horizon", target_os = "hurd"))]
+    #[cfg(any(target_os = "horizon", target_os = "hurd", target_os = "nuttx"))]
     pub fn accessed(&self) -> io::Result<SystemTime> {
         SystemTime::new(self.stat.st_atim.tv_sec as i64, self.stat.st_atim.tv_nsec as i64)
     }
@@ -866,6 +868,7 @@ impl Drop for Dir {
             target_os = "horizon",
             target_os = "vxworks",
             target_os = "rtems",
+            target_os = "nuttx",
         )))]
         {
             let fd = unsafe { libc::dirfd(self.0) };
@@ -1000,6 +1003,13 @@ impl DirEntry {
         self.entry.d_fileno as u64
     }
 
+    #[cfg(target_os = "nuttx")]
+    pub fn ino(&self) -> u64 {
+        // Leave this 0 for now, as NuttX does not provide an inode number
+        // in its directory entries.
+        0
+    }
+
     #[cfg(any(
         target_os = "netbsd",
         target_os = "openbsd",
@@ -1327,7 +1337,8 @@ impl File {
             target_os = "redox",
             target_os = "espidf",
             target_os = "horizon",
-            target_os = "vxworks"
+            target_os = "vxworks",
+            target_os = "nuttx",
         )))]
         let to_timespec = |time: Option<SystemTime>| match time {
             Some(time) if let Some(ts) = time.t.to_timespec() => Ok(ts),
@@ -1342,7 +1353,7 @@ impl File {
             None => Ok(libc::timespec { tv_sec: 0, tv_nsec: libc::UTIME_OMIT as _ }),
         };
         cfg_if::cfg_if! {
-            if #[cfg(any(target_os = "redox", target_os = "espidf", target_os = "horizon", target_os = "vxworks"))] {
+            if #[cfg(any(target_os = "redox", target_os = "espidf", target_os = "horizon", target_os = "vxworks", target_os = "nuttx"))] {
                 // Redox doesn't appear to support `UTIME_OMIT`.
                 // ESP-IDF and HorizonOS do not support `futimens` at all and the behavior for those OS is therefore
                 // the same as for Redox.
diff --git a/library/std/src/sys/pal/unix/mod.rs b/library/std/src/sys/pal/unix/mod.rs
index 0d63b1119d5..4fe18daa204 100644
--- a/library/std/src/sys/pal/unix/mod.rs
+++ b/library/std/src/sys/pal/unix/mod.rs
@@ -222,6 +222,7 @@ static ON_BROKEN_PIPE_FLAG_USED: crate::sync::atomic::AtomicBool =
     target_os = "horizon",
     target_os = "vxworks",
     target_os = "vita",
+    target_os = "nuttx",
 )))]
 pub(crate) fn on_broken_pipe_flag_used() -> bool {
     ON_BROKEN_PIPE_FLAG_USED.load(crate::sync::atomic::Ordering::Relaxed)
@@ -425,7 +426,7 @@ cfg_if::cfg_if! {
     }
 }
 
-#[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))]
+#[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita", target_os = "nuttx"))]
 mod unsupported {
     use crate::io;
 
diff --git a/library/std/src/sys/pal/unix/net.rs b/library/std/src/sys/pal/unix/net.rs
index e98232ba89a..0f2e015bbcd 100644
--- a/library/std/src/sys/pal/unix/net.rs
+++ b/library/std/src/sys/pal/unix/net.rs
@@ -38,19 +38,19 @@ pub fn cvt_gai(err: c_int) -> io::Result<()> {
     // We may need to trigger a glibc workaround. See on_resolver_failure() for details.
     on_resolver_failure();
 
-    #[cfg(not(target_os = "espidf"))]
+    #[cfg(not(any(target_os = "espidf", target_os = "nuttx")))]
     if err == libc::EAI_SYSTEM {
         return Err(io::Error::last_os_error());
     }
 
-    #[cfg(not(target_os = "espidf"))]
+    #[cfg(not(any(target_os = "espidf", target_os = "nuttx")))]
     let detail = unsafe {
         // We can't always expect a UTF-8 environment. When we don't get that luxury,
         // it's better to give a low-quality error message than none at all.
         CStr::from_ptr(libc::gai_strerror(err)).to_string_lossy()
     };
 
-    #[cfg(target_os = "espidf")]
+    #[cfg(any(target_os = "espidf", target_os = "nuttx"))]
     let detail = "";
 
     Err(io::Error::new(
diff --git a/library/std/src/sys/pal/unix/os.rs b/library/std/src/sys/pal/unix/os.rs
index 503f8915256..d99bde2f9a5 100644
--- a/library/std/src/sys/pal/unix/os.rs
+++ b/library/std/src/sys/pal/unix/os.rs
@@ -48,6 +48,7 @@ extern "C" {
             target_os = "openbsd",
             target_os = "android",
             target_os = "redox",
+            target_os = "nuttx",
             target_env = "newlib"
         ),
         link_name = "__errno"
@@ -399,6 +400,7 @@ pub fn current_exe() -> io::Result<PathBuf> {
     target_os = "linux",
     target_os = "hurd",
     target_os = "android",
+    target_os = "nuttx",
     target_os = "emscripten"
 ))]
 pub fn current_exe() -> io::Result<PathBuf> {
@@ -717,6 +719,7 @@ pub fn home_dir() -> Option<PathBuf> {
         target_os = "espidf",
         target_os = "horizon",
         target_os = "vita",
+        target_os = "nuttx",
         all(target_vendor = "apple", not(target_os = "macos")),
     ))]
     unsafe fn fallback() -> Option<OsString> {
@@ -730,6 +733,7 @@ pub fn home_dir() -> Option<PathBuf> {
         target_os = "espidf",
         target_os = "horizon",
         target_os = "vita",
+        target_os = "nuttx",
         all(target_vendor = "apple", not(target_os = "macos")),
     )))]
     unsafe fn fallback() -> Option<OsString> {
diff --git a/library/std/src/sys/pal/unix/process/mod.rs b/library/std/src/sys/pal/unix/process/mod.rs
index 074f0a105e3..2751d51c44d 100644
--- a/library/std/src/sys/pal/unix/process/mod.rs
+++ b/library/std/src/sys/pal/unix/process/mod.rs
@@ -2,10 +2,10 @@ pub use self::process_common::{Command, CommandArgs, ExitCode, Stdio, StdioPipes
 pub use self::process_inner::{ExitStatus, ExitStatusError, Process};
 pub use crate::ffi::OsString as EnvKey;
 
-#[cfg_attr(any(target_os = "espidf", target_os = "horizon"), allow(unused))]
+#[cfg_attr(any(target_os = "espidf", target_os = "horizon", target_os = "nuttx"), allow(unused))]
 mod process_common;
 
-#[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))]
+#[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita", target_os = "nuttx"))]
 mod process_unsupported;
 
 cfg_if::cfg_if! {
@@ -16,7 +16,7 @@ cfg_if::cfg_if! {
     } else if #[cfg(target_os = "vxworks")] {
         #[path = "process_vxworks.rs"]
         mod process_inner;
-    } else if #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita"))] {
+    } else if #[cfg(any(target_os = "espidf", target_os = "horizon", target_os = "vita", target_os = "nuttx"))] {
         mod process_inner {
             pub use super::process_unsupported::*;
         }
diff --git a/library/std/src/sys/pal/unix/thread.rs b/library/std/src/sys/pal/unix/thread.rs
index 7fe9b6c3e52..a0cf3b32103 100644
--- a/library/std/src/sys/pal/unix/thread.rs
+++ b/library/std/src/sys/pal/unix/thread.rs
@@ -140,7 +140,12 @@ impl Thread {
         }
     }
 
-    #[cfg(any(target_os = "freebsd", target_os = "dragonfly", target_os = "openbsd"))]
+    #[cfg(any(
+        target_os = "freebsd",
+        target_os = "dragonfly",
+        target_os = "openbsd",
+        target_os = "nuttx"
+    ))]
     pub fn set_name(name: &CStr) {
         unsafe {
             libc::pthread_set_name_np(libc::pthread_self(), name.as_ptr());
@@ -747,12 +752,15 @@ unsafe fn min_stack_size(attr: *const libc::pthread_attr_t) -> usize {
 }
 
 // No point in looking up __pthread_get_minstack() on non-glibc platforms.
-#[cfg(all(not(all(target_os = "linux", target_env = "gnu")), not(target_os = "netbsd")))]
+#[cfg(all(
+    not(all(target_os = "linux", target_env = "gnu")),
+    not(any(target_os = "netbsd", target_os = "nuttx"))
+))]
 unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
     libc::PTHREAD_STACK_MIN
 }
 
-#[cfg(target_os = "netbsd")]
+#[cfg(any(target_os = "netbsd", target_os = "nuttx"))]
 unsafe fn min_stack_size(_: *const libc::pthread_attr_t) -> usize {
     static STACK: crate::sync::OnceLock<usize> = crate::sync::OnceLock::new();
 
diff --git a/library/std/src/sys/personality/mod.rs b/library/std/src/sys/personality/mod.rs
index 68085d026c4..9754e840d15 100644
--- a/library/std/src/sys/personality/mod.rs
+++ b/library/std/src/sys/personality/mod.rs
@@ -31,7 +31,7 @@ cfg_if::cfg_if! {
         target_os = "psp",
         target_os = "xous",
         target_os = "solid_asp3",
-        all(target_family = "unix", not(target_os = "espidf"), not(target_os = "l4re"), not(target_os = "rtems")),
+        all(target_family = "unix", not(target_os = "espidf"), not(target_os = "l4re"), not(target_os = "rtems"), not(target_os = "nuttx")),
         all(target_vendor = "fortanix", target_env = "sgx"),
     ))] {
         mod gcc;
diff --git a/library/std/src/sys/random/mod.rs b/library/std/src/sys/random/mod.rs
index 16fb8c64c9b..d625814d15b 100644
--- a/library/std/src/sys/random/mod.rs
+++ b/library/std/src/sys/random/mod.rs
@@ -42,6 +42,7 @@ cfg_if::cfg_if! {
         target_os = "hurd",
         target_os = "l4re",
         target_os = "nto",
+        target_os = "nuttx",
     ))] {
         mod unix_legacy;
         pub use unix_legacy::fill_bytes;