Rollup merge of #40317 - malbarbo:update-libc, r=alexcrichton

Update libc to 0.2.21

Update to include android aarch64 and x86 improvements.

src/liblibc

@@ -1 +1 @@
-Subproject commit 64d954c6a76e896fbf7ed5c17e77c40e388abe84
+Subproject commit 05a2d197356ef253dfd985166576619ac9b6947f

src/libstd/os/raw.rs

@@ -14,22 +14,24 @@
 
 use fmt;
 
-#[cfg(any(target_os = "android",
-          target_os = "emscripten",
+#[cfg(any(target_os = "emscripten",
           all(target_os = "linux", any(target_arch = "aarch64",
                                        target_arch = "arm",
                                        target_arch = "powerpc",
                                        target_arch = "powerpc64",
                                        target_arch = "s390x")),
+          all(target_os = "android", any(target_arch = "aarch64",
+                                         target_arch = "arm")),
           all(target_os = "fuchsia", target_arch = "aarch64")))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_char = u8;
-#[cfg(not(any(target_os = "android",
-              target_os = "emscripten",
+#[cfg(not(any(target_os = "emscripten",
               all(target_os = "linux", any(target_arch = "aarch64",
                                            target_arch = "arm",
                                            target_arch = "powerpc",
                                            target_arch = "powerpc64",
                                            target_arch = "s390x")),
+              all(target_os = "android", any(target_arch = "aarch64",
+                                             target_arch = "arm")),
               all(target_os = "fuchsia", target_arch = "aarch64"))))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_char = i8;
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_schar = i8;

src/libstd/sys/unix/ext/net.rs

@@ -641,7 +641,7 @@ impl UnixListener {
                 let inner = Socket::new_raw(libc::AF_UNIX, libc::SOCK_STREAM)?;
                 let (addr, len) = sockaddr_un(path)?;
 
-                cvt(libc::bind(*inner.as_inner(), &addr as *const _ as *const _, len))?;
+                cvt(libc::bind(*inner.as_inner(), &addr as *const _ as *const _, len as _))?;
                 cvt(libc::listen(*inner.as_inner(), 128))?;
 
                 Ok(UnixListener(inner))
@@ -920,7 +920,7 @@ impl UnixDatagram {
                 let socket = UnixDatagram::unbound()?;
                 let (addr, len) = sockaddr_un(path)?;
 
-                cvt(libc::bind(*socket.0.as_inner(), &addr as *const _ as *const _, len))?;
+                cvt(libc::bind(*socket.0.as_inner(), &addr as *const _ as *const _, len as _))?;
 
                 Ok(socket)
             }

src/libstd/sys/unix/process/process_common.rs

@@ -417,12 +417,26 @@ mod tests {
         }
     }
 
+    // Android with api less than 21 define sig* functions inline, so it is not
+    // available for dynamic link. Implementing sigemptyset and sigaddset allow us
+    // to support older Android version (independent of libc version).
+    // The following implementations are based on https://git.io/vSkNf
+
     #[cfg(not(target_os = "android"))]
     extern {
+        #[cfg_attr(target_os = "netbsd", link_name = "__sigemptyset14")]
+        fn sigemptyset(set: *mut libc::sigset_t) -> libc::c_int;
+
         #[cfg_attr(target_os = "netbsd", link_name = "__sigaddset14")]
         fn sigaddset(set: *mut libc::sigset_t, signum: libc::c_int) -> libc::c_int;
     }
 
+    #[cfg(target_os = "android")]
+    unsafe fn sigemptyset(set: *mut libc::sigset_t) -> libc::c_int {
+        libc::memset(set as *mut _, 0, mem::size_of::<libc::sigset_t>());
+        return 0;
+    }
+
     #[cfg(target_os = "android")]
     unsafe fn sigaddset(set: *mut libc::sigset_t, signum: libc::c_int) -> libc::c_int {
         use slice;
@@ -450,7 +464,7 @@ mod tests {
 
             let mut set: libc::sigset_t = mem::uninitialized();
             let mut old_set: libc::sigset_t = mem::uninitialized();
-            t!(cvt(libc::sigemptyset(&mut set)));
+            t!(cvt(sigemptyset(&mut set)));
             t!(cvt(sigaddset(&mut set, libc::SIGINT)));
             t!(cvt(libc::pthread_sigmask(libc::SIG_SETMASK, &set, &mut old_set)));
 

src/libstd/sys/unix/process/process_unix.rs

@@ -193,7 +193,16 @@ impl Command {
             // need to clean things up now to avoid confusing the program
             // we're about to run.
             let mut set: libc::sigset_t = mem::uninitialized();
-            t!(cvt(libc::sigemptyset(&mut set)));
+            if cfg!(target_os = "android") {
+                // Implementing sigemptyset allow us to support older Android
+                // versions. See the comment about Android and sig* functions in
+                // process_common.rs
+                libc::memset(&mut set as *mut _ as *mut _,
+                             0,
+                             mem::size_of::<libc::sigset_t>());
+            } else {
+                t!(cvt(libc::sigemptyset(&mut set)));
+            }
             t!(cvt(libc::pthread_sigmask(libc::SIG_SETMASK, &set,
                                          ptr::null_mut())));
             let ret = sys::signal(libc::SIGPIPE, libc::SIG_DFL);

src/libstd/sys_common/net.rs

@@ -339,7 +339,7 @@ impl TcpListener {
 
         // Bind our new socket
         let (addrp, len) = addr.into_inner();
-        cvt(unsafe { c::bind(*sock.as_inner(), addrp, len) })?;
+        cvt(unsafe { c::bind(*sock.as_inner(), addrp, len as _) })?;
 
         // Start listening
         cvt(unsafe { c::listen(*sock.as_inner(), 128) })?;
@@ -430,7 +430,7 @@ impl UdpSocket {
 
         let sock = Socket::new(addr, c::SOCK_DGRAM)?;
         let (addrp, len) = addr.into_inner();
-        cvt(unsafe { c::bind(*sock.as_inner(), addrp, len) })?;
+        cvt(unsafe { c::bind(*sock.as_inner(), addrp, len as _) })?;
         Ok(UdpSocket { inner: sock })
     }