Auto merge of #2468 - unrelentingtech:fbsd-efd, r=JohnTitor

FreeBSD: add eventfd (since 13)

This already exposes constants in the non-versioned code like #2465 so this should wait on #2465…

Author: bors

libc-test/build.rs

@@ -1764,8 +1764,13 @@ fn test_freebsd(target: &str) {
         _ => cfg.define("_WANT_FREEBSD11_STAT", None),
     };
 
-    let freebsdlast = match freebsd_ver {
-        Some(12) | Some(13) => true,
+    let freebsd12 = match freebsd_ver {
+        Some(n) if n >= 12 => true,
+        _ => false,
+    };
+
+    let freebsd13 = match freebsd_ver {
+        Some(n) if n >= 13 => true,
         _ => false,
     };
 
@@ -1818,10 +1823,11 @@ fn test_freebsd(target: &str) {
                 "stdlib.h",
                 "string.h",
                 "sys/capsicum.h",
-                [freebsdlast]:"sys/auxv.h",
+                [freebsd12]:"sys/auxv.h",
                 "sys/cpuset.h",
-                [freebsdlast]:"sys/domainset.h",
+                [freebsd12]:"sys/domainset.h",
                 "sys/event.h",
+                [freebsd13]:"sys/eventfd.h",
                 "sys/extattr.h",
                 "sys/file.h",
                 "sys/ioctl.h",
@@ -1914,6 +1920,9 @@ fn test_freebsd(target: &str) {
                 true
             }
 
+            // These constants were introduced in FreeBSD 13:
+            "EFD_CLOEXEC" | "EFD_NONBLOCK" | "EFD_SEMAPHORE" if Some(13) > freebsd_ver => true,
+
             // These constants were introduced in FreeBSD 12:
             "SF_USER_READAHEAD"
             | "EVFILT_EMPTY"

src/unix/bsd/freebsdlike/freebsd/freebsd13/mod.rs

@@ -265,6 +265,8 @@ extern "C" {
         rmtp: *mut ::timespec,
     ) -> ::c_int;
 
+    pub fn eventfd(init: ::c_uint, flags: ::c_int) -> ::c_int;
+
     pub fn fdatasync(fd: ::c_int) -> ::c_int;
 
     pub fn getrandom(buf: *mut ::c_void, buflen: ::size_t, flags: ::c_uint) -> ::ssize_t;

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

@@ -1717,6 +1717,11 @@ pub const RFLINUXTHPN: ::c_int = 65536;
 pub const RFTSIGZMB: ::c_int = 524288;
 pub const RFSPAWN: ::c_int = 2147483648;
 
+// For eventfd
+pub const EFD_SEMAPHORE: ::c_int = 0x1;
+pub const EFD_NONBLOCK: ::c_int = 0x4;
+pub const EFD_CLOEXEC: ::c_int = 0x100000;
+
 pub const MALLOCX_ZERO: ::c_int = 0x40;
 
 /// size of returned wchan message