Commit 9d18df142c2b1583fcf0d59982b571699a63223e | zig

author	LemonBoy <thatlemon@gmail.com> 2021-01-18 13:24:06+01:00
committer	LemonBoy <thatlemon@gmail.com> 2021-01-18 14:52:35+01:00
log	9d18df142c2b1583fcf0d59982b571699a63223e
tree	e728f42a2f7b21482267847141638b62fc3e1833
parent	81183365852e7f871500a3f71810ae3b468f0027

std: Fixed pipe2 fallback

Use both F_SETFD and F_SETFL depending on what flag we're setting.

Closes #7760

1 files changed, 42 insertions(+), 19 deletions(-)

lib
- std
  - os.zig

lib/std/os.zig+42-19

 @@ -3755,31 +3755,54 @@ pub fn pipe() PipeError![2]fd_t {
 }
 pub fn pipe2(flags: u32) PipeError![2]fd_t {
-    if (comptime std.Target.current.isDarwin()) {
+    if (@hasDecl(system, "pipe2")) {
-        var fds: [2]fd_t = try pipe();
+        var fds: [2]fd_t = undefined;
-        if (flags == 0) return fds;
+        switch (errno(system.pipe2(&fds, flags))) {
-        errdefer {
+            0 => return fds,
-            close(fds[0]);
-            close(fds[1]);
-        }
-        for (fds) |fd| switch (errno(system.fcntl(fd, F_SETFL, flags))) {
-            0 => {},
             EINVAL => unreachable, // Invalid flags
-            EBADF => unreachable, // Always a race condition
+            EFAULT => unreachable, // Invalid fds pointer
+            ENFILE => return error.SystemFdQuotaExceeded,
+            EMFILE => return error.ProcessFdQuotaExceeded,
             else => |err| return unexpectedErrno(err),
-        };
+        }
+    }
+    var fds: [2]fd_t = try pipe();
+    errdefer {
+        close(fds[0]);
+        close(fds[1]);
+    }
+    if (flags == 0)
         return fds;
+    // O_CLOEXEC is special, it's a file descriptor flag and must be set using
+    // F_SETFD.
+    if (flags & O_CLOEXEC != 0) {
+        for (fds) |fd| {
+            switch (errno(system.fcntl(fd, F_SETFD, FD_CLOEXEC))) {
+                0 => {},
+                EINVAL => unreachable, // Invalid flags
+                EBADF => unreachable, // Always a race condition
+                else => |err| return unexpectedErrno(err),
+            }
+        }
     }
-    var fds: [2]fd_t = undefined;
+    const new_flags = flags & ~@as(u32, O_CLOEXEC);
-    switch (errno(system.pipe2(&fds, flags))) {
+    // Set every other flag affecting the file status using F_SETFL.
-        0 => return fds,
+    if (new_flags != 0) {
-        EINVAL => unreachable, // Invalid flags
+        for (fds) |fd| {
-        EFAULT => unreachable, // Invalid fds pointer
+            switch (errno(system.fcntl(fd, F_SETFL, new_flags))) {
-        ENFILE => return error.SystemFdQuotaExceeded,
+                0 => {},
-        EMFILE => return error.ProcessFdQuotaExceeded,
+                EINVAL => unreachable, // Invalid flags
-        else => |err| return unexpectedErrno(err),
+                EBADF => unreachable, // Always a race condition
+                else => |err| return unexpectedErrno(err),
+            }
+        }
     }
+    return fds;
 }
 pub const SysCtlError = error{