libgo: update to Go 1.13beta1 release

    
    Reviewed-on: https://go-review.googlesource.com/c/gofrontend/+/193497

From-SVN: r275473

1 files changed, 28 insertions, 13 deletions

diff --git a/libgo/go/os/file_unix.go b/libgo/go/os/file_unix.go
index 912ba5a..750771f 100644
--- a/libgo/go/os/file_unix.go
+++ b/libgo/go/os/file_unix.go
@@ -52,6 +52,7 @@ type file struct {
 	dirinfo     *dirInfo // nil unless directory being read
 	nonblock    bool     // whether we set nonblocking mode
 	stdoutOrErr bool     // whether this is stdout or stderr
+	appendMode  bool     // whether file is opened for appending
 }
 
 // Fd returns the integer Unix file descriptor referencing the open file.
@@ -121,33 +122,27 @@ func newFile(fd uintptr, name string, kind newFileKind) *File {
 	// we assume they know what they are doing so we allow it to be
 	// used with kqueue.
 	if kind == kindOpenFile {
-		var st syscall.Stat_t
 		switch runtime.GOOS {
-		case "freebsd":
-			// On FreeBSD before 10.4 it used to crash the
-			// system unpredictably while running all.bash.
-			// When we stop supporting FreeBSD 10 we can merge
-			// this into the dragonfly/netbsd/openbsd case.
-			// Issue 27619.
-			pollable = false
-
-		case "dragonfly", "netbsd", "openbsd":
+		case "darwin", "dragonfly", "freebsd", "netbsd", "openbsd":
+			var st syscall.Stat_t
+			err := syscall.Fstat(fdi, &st)
+			typ := st.Mode & syscall.S_IFMT
 			// Don't try to use kqueue with regular files on *BSDs.
 			// On FreeBSD a regular file is always
 			// reported as ready for writing.
 			// On Dragonfly, NetBSD and OpenBSD the fd is signaled
 			// only once as ready (both read and write).
 			// Issue 19093.
-			if err := syscall.Fstat(fdi, &st); err == nil && st.Mode&syscall.S_IFMT == syscall.S_IFREG {
+			// Also don't add directories to the netpoller.
+			if err == nil && (typ == syscall.S_IFREG || typ == syscall.S_IFDIR) {
 				pollable = false
 			}
 
-		case "darwin":
 			// In addition to the behavior described above for regular files,
 			// on Darwin, kqueue does not work properly with fifos:
 			// closing the last writer does not cause a kqueue event
 			// for any readers. See issue #24164.
-			if err := syscall.Fstat(fdi, &st); err == nil && (st.Mode&syscall.S_IFMT == syscall.S_IFIFO || st.Mode&syscall.S_IFMT == syscall.S_IFREG) {
+			if runtime.GOOS == "darwin" && typ == syscall.S_IFIFO {
 				pollable = false
 			}
 		}
@@ -236,6 +231,7 @@ func openFileNolog(name string, flag int, perm FileMode) (*File, error) {
 // Close closes the File, rendering it unusable for I/O.
 // On files that support SetDeadline, any pending I/O operations will
 // be canceled and return immediately with an error.
+// Close will return an error if it has already been called.
 func (f *File) Close() error {
 	if f == nil {
 		return ErrInvalid
@@ -413,3 +409,22 @@ func (f *File) readdir(n int) (fi []FileInfo, err error) {
 	}
 	return fi, err
 }
+
+// Readlink returns the destination of the named symbolic link.
+// If there is an error, it will be of type *PathError.
+func Readlink(name string) (string, error) {
+	for len := 128; ; len *= 2 {
+		b := make([]byte, len)
+		n, e := fixCount(syscall.Readlink(name, b))
+		// buffer too small
+		if runtime.GOOS == "aix" && e == syscall.ERANGE {
+			continue
+		}
+		if e != nil {
+			return "", &PathError{"readlink", name, e}
+		}
+		if n < len {
+			return string(b[0:n]), nil
+		}
+	}
+}