Auto merge of #2526 - devnexen:sem_fbsd, r=Amanieu

freebsd sem api addition

libc-test/build.rs

@@ -1845,6 +1845,7 @@ fn test_freebsd(target: &str) {
                 "sys/random.h",
                 "sys/resource.h",
                 "sys/rtprio.h",
+                "sys/sem.h",
                 "sys/shm.h",
                 "sys/socket.h",
                 "sys/stat.h",
@@ -2176,6 +2177,9 @@ fn test_freebsd(target: &str) {
             // We ignore this field because we needed to use a hack in order to make rust 1.19
             // happy...
             ("kinfo_proc", "ki_sparestrings") => true,
+
+            // `__sem_base` is a private struct field
+            ("semid_ds", "__sem_base") => true,
             _ => false,
         }
     });

libc-test/semver/freebsd.txt

@@ -1735,6 +1735,11 @@ sem_init
 sem_open
 sem_timedwait
 sem_unlink
+sembuf
+semctl
+semget
+semid_ds
+semop
 sendfile
 sendmmsg
 sendmsg

src/unix/bsd/freebsdlike/freebsd/mod.rs

@@ -87,6 +87,11 @@ s! {
     pub struct _sem {
         data: [u32; 4],
     }
+    pub struct sembuf {
+        pub sem_num: ::c_ushort,
+        pub sem_op: ::c_short,
+        pub sem_flg: ::c_short,
+    }
 
     pub struct msqid_ds {
         pub msg_perm: ::ipc_perm,
@@ -445,6 +450,18 @@ s! {
         pub n_type: ::c_uchar,
         pub n_value: ::kvaddr_t,
     }
+
+    pub struct __c_anonymous_sem {
+        _priv: ::uintptr_t,
+    }
+
+    pub struct semid_ds {
+        pub sem_perm: ::ipc_perm,
+        pub __sem_base: *mut __c_anonymous_sem,
+        pub sem_nsems: ::c_ushort,
+        pub sem_otime: ::time_t,
+        pub sem_ctime: ::time_t,
+    }
 }
 
 s_no_extra_traits! {
@@ -2196,6 +2213,9 @@ extern "C" {
     pub fn shmat(shmid: ::c_int, shmaddr: *const ::c_void, shmflg: ::c_int) -> *mut ::c_void;
     pub fn shmdt(shmaddr: *const ::c_void) -> ::c_int;
     pub fn shmctl(shmid: ::c_int, cmd: ::c_int, buf: *mut ::shmid_ds) -> ::c_int;
+    pub fn semget(key: ::key_t, nsems: ::c_int, semflg: ::c_int) -> ::c_int;
+    pub fn semctl(semid: ::c_int, semnum: ::c_int, cmd: ::c_int, ...) -> ::c_int;
+    pub fn semop(semid: ::c_int, sops: *mut sembuf, nsops: ::size_t) -> ::c_int;
     pub fn msgctl(msqid: ::c_int, cmd: ::c_int, buf: *mut ::msqid_ds) -> ::c_int;
     pub fn msgget(key: ::key_t, msgflg: ::c_int) -> ::c_int;
     pub fn msgsnd(