Add waitid and related constants and types.

src/unix/bsd/apple/mod.rs

@@ -1363,6 +1363,11 @@ pub const LIO_READ: ::c_int = 1;
 pub const LIO_WAIT: ::c_int = 2;
 pub const LIO_NOWAIT: ::c_int = 1;
 
+pub const WEXITED: ::c_int = 0x00000004;
+pub const WSTOPPED: ::c_int = 0x00000008;
+pub const WCONTINUED: ::c_int = 0x00000010;
+pub const WNOWAIT: ::c_int = 0x00000020;
+
 f! {
     pub fn WSTOPSIG(status: ::c_int) -> ::c_int {
         status >> 8

src/unix/bsd/freebsdlike/mod.rs

@@ -693,6 +693,12 @@ pub const TIOCSWINSZ: ::c_ulong = 0x80087467;
 
 pub const SEM_FAILED: *mut sem_t = 0 as *mut sem_t;
 
+pub const WSTOPPED: ::c_int = 2; // same as WUNTRACED
+pub const WCONTINUED: ::c_int = 4;
+pub const WNOWAIT: ::c_int = 8;
+pub const WEXITED: ::c_int = 16;
+pub const WTRAPPED: ::c_int = 32;
+
 f! {
     pub fn WSTOPSIG(status: ::c_int) -> ::c_int {
         status >> 8

src/unix/bsd/netbsdlike/netbsd/mod.rs

@@ -583,6 +583,11 @@ pub const SIGEV_NONE: ::c_int = 0;
 pub const SIGEV_SIGNAL: ::c_int = 1;
 pub const SIGEV_THREAD: ::c_int = 2;
 
+pub const WSTOPPED: ::c_int = 0x00000002; // same as WUNTRACED
+pub const WCONTINUED: ::c_int = 0x00000010;
+pub const WEXITED: ::c_int = 0x000000020;
+pub const WNOWAIT: ::c_int = 0x00010000;
+
 extern {
     pub fn aio_read(aiocbp: *mut aiocb) -> ::c_int;
     pub fn aio_write(aiocbp: *mut aiocb) -> ::c_int;

src/unix/mod.rs

@@ -16,6 +16,20 @@ pub type cc_t = ::c_uchar;
 pub enum DIR {}
 pub enum locale_t {}
 
+// idtype_t is specified as a C enum:
+// http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/sys_wait.h.html
+// However, FFI doesn't currently know how to ABI-match a C enum
+// (rust#28925, rust#34641).
+cfg_if! {
+    if #[cfg(target_os = "openbsd")] {
+        // idtype_t is not available
+    } else if #[cfg(target_os = "android")] {
+        pub type idtype_t = ::c_int;
+    } else {
+        pub type idtype_t = ::c_uint;
+    }
+}
+
 s! {
     pub struct group {
         pub gr_name: *mut ::c_char,
@@ -203,6 +217,22 @@ pub const PRIO_USER: ::c_int = 2;
 pub const PRIO_MIN: ::c_int = -20;
 pub const PRIO_MAX: ::c_int = 20;
 
+cfg_if! {
+    if #[cfg(target_os = "openbsd")] {
+        // P_* constants are not available
+    } else if #[cfg(target_os = "freebsd")] {
+        // FreeBSD defines a great many more of these, and gives the
+        // standardized constants different values from everyone else.
+        pub const P_PID: idtype_t = 0;
+        pub const P_PGID: idtype_t = 2;
+        pub const P_ALL: idtype_t = 7;
+    } else {
+        pub const P_ALL: idtype_t = 0;
+        pub const P_PID: idtype_t = 1;
+        pub const P_PGID: idtype_t = 2;
+    }
+}
+
 cfg_if! {
     if #[cfg(dox)] {
         // on dox builds don't pull in anything
@@ -447,6 +477,11 @@ extern {
                link_name = "waitpid$UNIX2003")]
     pub fn waitpid(pid: pid_t, status: *mut ::c_int, options: ::c_int)
                    -> pid_t;
+    #[cfg(not(any(target_os = "openbsd", target_os = "netbsd")))] // " if "
+    #[cfg_attr(all(target_os = "macos", target_arch = "x86"),
+               link_name = "waitid$UNIX2003")]
+    pub fn waitid(idtype: idtype_t, id: id_t, infop: *mut ::siginfo_t,
+                  options: ::c_int) -> ::c_int;
     #[cfg_attr(all(target_os = "macos", target_arch = "x86"),
                link_name = "write$UNIX2003")]
     pub fn write(fd: ::c_int, buf: *const ::c_void, count: ::size_t)