Add a way to get the raw fields out of a WaitStatus. (#1300)

Author: sunfishcode

src/backend/linux_raw/process/wait.rs

@@ -1,7 +1,7 @@
 // The functions replacing the C macros use the same names as in libc.
 #![allow(non_snake_case, unsafe_code)]
 
-use linux_raw_sys::ctypes::c_int;
+use crate::ffi::c_int;
 pub(crate) use linux_raw_sys::general::{
     siginfo_t, WCONTINUED, WEXITED, WNOHANG, WNOWAIT, WSTOPPED, WUNTRACED,
 };
@@ -42,11 +42,27 @@ pub(crate) fn WEXITSTATUS(status: u32) -> u32 {
 }
 
 pub(crate) trait SiginfoExt {
+    fn si_signo(&self) -> c_int;
+    fn si_errno(&self) -> c_int;
     fn si_code(&self) -> c_int;
     unsafe fn si_status(&self) -> c_int;
 }
 
 impl SiginfoExt for siginfo_t {
+    #[inline]
+    fn si_signo(&self) -> c_int {
+        // SAFETY: This is technically a union access, but it's only a union
+        // with padding.
+        unsafe { self.__bindgen_anon_1.__bindgen_anon_1.si_signo }
+    }
+
+    #[inline]
+    fn si_errno(&self) -> c_int {
+        // SAFETY: This is technically a union access, but it's only a union
+        // with padding.
+        unsafe { self.__bindgen_anon_1.__bindgen_anon_1.si_errno }
+    }
+
     #[inline]
     fn si_code(&self) -> c_int {
         // SAFETY: This is technically a union access, but it's only a union

src/process/wait.rs

@@ -142,39 +142,39 @@ impl WaitIdStatus {
     /// Returns whether the process is currently stopped.
     #[inline]
     pub fn stopped(&self) -> bool {
-        self.si_code() == backend::c::CLD_STOPPED
+        self.raw_code() == bitcast!(backend::c::CLD_STOPPED)
     }
 
     /// Returns whether the process is currently trapped.
     #[inline]
     pub fn trapped(&self) -> bool {
-        self.si_code() == backend::c::CLD_TRAPPED
+        self.raw_code() == bitcast!(backend::c::CLD_TRAPPED)
     }
 
     /// Returns whether the process has exited normally.
     #[inline]
     pub fn exited(&self) -> bool {
-        self.si_code() == backend::c::CLD_EXITED
+        self.raw_code() == bitcast!(backend::c::CLD_EXITED)
     }
 
     /// Returns whether the process was terminated by a signal and did not
     /// create a core file.
     #[inline]
     pub fn killed(&self) -> bool {
-        self.si_code() == backend::c::CLD_KILLED
+        self.raw_code() == bitcast!(backend::c::CLD_KILLED)
     }
 
     /// Returns whether the process was terminated by a signal and did create a
     /// core file.
     #[inline]
     pub fn dumped(&self) -> bool {
-        self.si_code() == backend::c::CLD_DUMPED
+        self.raw_code() == bitcast!(backend::c::CLD_DUMPED)
     }
 
     /// Returns whether the process has continued from a job control stop.
     #[inline]
     pub fn continued(&self) -> bool {
-        self.si_code() == backend::c::CLD_CONTINUED
+        self.raw_code() == bitcast!(backend::c::CLD_CONTINUED)
     }
 
     /// Returns the number of the signal that stopped the process, if the
@@ -225,19 +225,45 @@ impl WaitIdStatus {
         }
     }
 
+    /// Return the raw `si_signo` value returned from `waitid`.
     #[cfg(linux_raw)]
-    fn si_code(&self) -> u32 {
-        self.0.si_code() as u32 // CLD_ consts are unsigned
+    pub fn raw_signo(&self) -> crate::ffi::c_int {
+        self.0.si_signo()
     }
 
+    /// Return the raw `si_signo` value returned from `waitid`.
     #[cfg(not(linux_raw))]
-    fn si_code(&self) -> backend::c::c_int {
+    pub fn raw_signo(&self) -> crate::ffi::c_int {
+        self.0.si_signo
+    }
+
+    /// Return the raw `si_errno` value returned from `waitid`.
+    #[cfg(linux_raw)]
+    pub fn raw_errno(&self) -> crate::ffi::c_int {
+        self.0.si_errno()
+    }
+
+    /// Return the raw `si_errno` value returned from `waitid`.
+    #[cfg(not(linux_raw))]
+    pub fn raw_errno(&self) -> crate::ffi::c_int {
+        self.0.si_errno
+    }
+
+    /// Return the raw `si_code` value returned from `waitid`.
+    #[cfg(linux_raw)]
+    pub fn raw_code(&self) -> crate::ffi::c_int {
+        self.0.si_code()
+    }
+
+    /// Return the raw `si_code` value returned from `waitid`.
+    #[cfg(not(linux_raw))]
+    pub fn raw_code(&self) -> crate::ffi::c_int {
         self.0.si_code
     }
 
     #[cfg(not(any(target_os = "emscripten", target_os = "fuchsia", target_os = "netbsd")))]
     #[allow(unsafe_code)]
-    fn si_status(&self) -> backend::c::c_int {
+    fn si_status(&self) -> crate::ffi::c_int {
         // SAFETY: POSIX [specifies] that the `siginfo_t` returned by a
         // `waitid` call always has a valid `si_status` value.
         //

tests/process/wait.rs

@@ -23,6 +23,7 @@ fn test_waitpid_none() {
         .unwrap();
     assert_eq!(pid, process::Pid::from_child(&child));
     assert!(status.stopped());
+    assert_ne!(status.as_raw(), 0);
 
     // Clean up the child process.
     unsafe { kill(child.id() as _, SIGKILL) };
@@ -50,6 +51,7 @@ fn test_waitpid_some() {
         .unwrap();
     assert_eq!(rpid, pid);
     assert!(status.stopped());
+    assert_ne!(status.as_raw(), 0);
 
     // Clean up the child process.
     unsafe { kill(child.id() as _, SIGKILL) };
@@ -77,6 +79,7 @@ fn test_waitpgid() {
         .unwrap();
     assert_eq!(pid, process::Pid::from_child(&child));
     assert!(status.stopped());
+    assert_ne!(status.as_raw(), 0);
 
     // Clean up the child process.
     unsafe { kill(child.id() as _, SIGKILL) };
@@ -116,6 +119,9 @@ fn test_waitid() {
     assert!(status.stopped());
     #[cfg(not(any(target_os = "fuchsia", target_os = "netbsd")))]
     assert_eq!(status.stopping_signal(), Some(SIGSTOP as _));
+    assert_eq!(status.raw_signo(), libc::SIGCHLD);
+    assert_eq!(status.raw_errno(), 0);
+    assert_eq!(status.raw_code(), libc::CLD_STOPPED);
 
     unsafe { kill(child.id() as _, SIGCONT) };
 
@@ -139,6 +145,9 @@ fn test_waitid() {
     assert!(status.stopped());
     #[cfg(not(any(target_os = "fuchsia", target_os = "netbsd")))]
     assert_eq!(status.stopping_signal(), Some(SIGSTOP as _));
+    assert_eq!(status.raw_signo(), libc::SIGCHLD);
+    assert_eq!(status.raw_errno(), 0);
+    assert_eq!(status.raw_code(), libc::CLD_STOPPED);
 
     unsafe { kill(child.id() as _, SIGCONT) };