Remove os::waitpid because:

- The return value meant different things on different
   platforms (on windows, it was the exit code, on unix it was
   the status information returned from waitpid).
 - It was undocumented.
 - There also exists run::waitpid, which does much the same
   thing but has a more consistent return value and also some
   documentation.

src/libcore/os.rs

@@ -60,7 +60,6 @@ pub mod rustrt {
         unsafe fn rust_get_argv() -> **c_char;
         unsafe fn rust_path_is_dir(path: *libc::c_char) -> c_int;
         unsafe fn rust_path_exists(path: *libc::c_char) -> c_int;
-        unsafe fn rust_process_wait(pid: c_int) -> c_int;
         unsafe fn rust_set_exit_status(code: libc::intptr_t);
     }
 }
@@ -352,31 +351,6 @@ pub fn fsync_fd(fd: c_int, _l: io::fsync::Level) -> c_int {
     }
 }
 
-
-#[cfg(windows)]
-pub fn waitpid(pid: pid_t) -> c_int {
-    unsafe {
-        let status = rustrt::rust_process_wait(pid);
-        if status < 0 {
-            fail!(fmt!("failure in rust_process_wait: %s", last_os_error()));
-        }
-        return status;
-    }
-}
-
-#[cfg(unix)]
-pub fn waitpid(pid: pid_t) -> c_int {
-    unsafe {
-        use libc::funcs::posix01::wait::*;
-        let mut status = 0 as c_int;
-
-        assert!((waitpid(pid, &mut status, 0 as c_int) !=
-                     (-1 as c_int)));
-        return status;
-    }
-}
-
-
 pub struct Pipe { mut in: c_int, mut out: c_int }
 
 #[cfg(unix)]

src/libcore/run.rs

@@ -36,6 +36,7 @@ pub mod rustrt {
                                    in_fd: c_int,
                                    out_fd: c_int,
                                    err_fd: c_int) -> run::RunProgramResult;
+        unsafe fn rust_process_wait(pid: c_int) -> c_int;
     }
 }
 
@@ -503,17 +504,27 @@ pub fn readclose(fd: c_int) -> ~str {
     }
 }
 
-/// Waits for a process to exit and returns the exit code
+/**
+ * Waits for a process to exit and returns the exit code, failing
+ * if there is no process with the specified id.
+ */
 pub fn waitpid(pid: pid_t) -> int {
     return waitpid_os(pid);
 
     #[cfg(windows)]
     fn waitpid_os(pid: pid_t) -> int {
-        os::waitpid(pid) as int
+        let status = unsafe { rustrt::rust_process_wait(pid) };
+        if status < 0 {
+            fail!(fmt!("failure in rust_process_wait: %s", os::last_os_error()));
+        }
+        return status as int;
     }
 
     #[cfg(unix)]
     fn waitpid_os(pid: pid_t) -> int {
+
+        use libc::funcs::posix01::wait::*;
+
         #[cfg(target_os = "linux")]
         #[cfg(target_os = "android")]
         fn WIFEXITED(status: i32) -> bool {
@@ -538,7 +549,11 @@ pub fn waitpid(pid: pid_t) -> int {
             status >> 8i32
         }
 
-        let status = os::waitpid(pid);
+        let mut status = 0 as c_int;
+        if unsafe { waitpid(pid, &mut status, 0) } == -1 {
+            fail!(fmt!("failure in waitpid: %s", os::last_os_error()));
+        }
+
         return if WIFEXITED(status) {
             WEXITSTATUS(status) as int
         } else {
@@ -584,7 +599,7 @@ mod tests {
         writeclose(pipe_in.out, copy expected);
         let actual = readclose(pipe_out.in);
         readclose(pipe_err.in);
-        os::waitpid(pid);
+        run::waitpid(pid);
 
         debug!(copy expected);
         debug!(copy actual);