os: delete Exec, NewFile takes uintptr, rename ShellExpand, doc fixes

Delete O_NDELAY, O_NONBLOCK, O_NOCTTY, O_ASYNC.

Clean up some docs.

Rename ShellExpand -> ExpandEnv.

Make NewFile take a uintptr; change File.Fd to return one.
(for API compatibility between Unix and Windows)

Fixes #2947

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5655045

Author: bradfitz

doc/go1.html

@@ -1353,10 +1353,19 @@ <h3 id="os">The os package</h3>
 the <a href="/pkg/time/#Time"><code>Time</code></a> type from the
 <code>time</code> package.</p>
 
-<p>
-<em>Updating</em>:
-Code that uses <code>os.Time</code> will fail to compile and must be updated by hand.
-</p>
+<p>The <code>Exec</code> function has been removed; callers should use
+<code>Exec</code> from the <code>syscall</code> package, where available.</p>
+
+<p>The <code>ShellExpand</code> function has been renamed to <a
+href="/pkg/os/#ExpandEnv"><code>ExpandEnv</code></a>.</p>
+
+<p>The <a href="/pkg/os/#NewFile"><code>NewFile</code></a> function
+now takes a <code>uintptr</code> fd, instead of an <code>int</code>.
+The <a href="/pkg/os/#File.Fd"><code>Fd</code></a> method on files now
+also returns a <code>uintptr</code>.</p>
+
+<p><em>Updating</em>: Code will fail to compile and must be updated
+by hand.  </p>
 
 <h4 id="os_fileinfo">The os.FileInfo type</h4>
 

doc/go1.tmpl

@@ -1256,10 +1256,19 @@ The semantic change makes it difficult for the fix tool to update automatically.
 the <a href="/pkg/time/#Time"><code>Time</code></a> type from the
 <code>time</code> package.</p>
 
-<p>
-<em>Updating</em>:
-Code that uses <code>os.Time</code> will fail to compile and must be updated by hand.
-</p>
+<p>The <code>Exec</code> function has been removed; callers should use
+<code>Exec</code> from the <code>syscall</code> package, where available.</p>
+
+<p>The <code>ShellExpand</code> function has been renamed to <a
+href="/pkg/os/#ExpandEnv"><code>ExpandEnv</code></a>.</p>
+
+<p>The <a href="/pkg/os/#NewFile"><code>NewFile</code></a> function
+now takes a <code>uintptr</code> fd, instead of an <code>int</code>.
+The <a href="/pkg/os/#File.Fd"><code>Fd</code></a> method on files now
+also returns a <code>uintptr</code>.</p>
+
+<p><em>Updating</em>: Code will fail to compile and must be updated
+by hand.  </p>
 
 <h4 id="os_fileinfo">The os.FileInfo type</h4>
 

src/pkg/net/fd.go

@@ -228,7 +228,7 @@ func (s *pollServer) Run() {
 			s.CheckDeadlines()
 			continue
 		}
-		if fd == s.pr.Fd() {
+		if fd == int(s.pr.Fd()) {
 			// Drain our wakeup pipe (we could loop here,
 			// but it's unlikely that there are more than
 			// len(scratch) wakeup calls).
@@ -295,7 +295,7 @@ func (fd *netFD) setAddr(laddr, raddr Addr) {
 	if raddr != nil {
 		rs = raddr.String()
 	}
-	fd.sysfile = os.NewFile(fd.sysfd, fd.net+":"+ls+"->"+rs)
+	fd.sysfile = os.NewFile(uintptr(fd.sysfd), fd.net+":"+ls+"->"+rs)
 }
 
 func (fd *netFD) connect(ra syscall.Sockaddr) error {
@@ -382,7 +382,7 @@ func (fd *netFD) Read(p []byte) (n int, err error) {
 		return 0, os.EINVAL
 	}
 	for {
-		n, err = syscall.Read(fd.sysfile.Fd(), p)
+		n, err = syscall.Read(int(fd.sysfile.Fd()), p)
 		if err == syscall.EAGAIN {
 			if fd.rdeadline >= 0 {
 				pollserver.WaitRead(fd)
@@ -476,7 +476,7 @@ func (fd *netFD) Write(p []byte) (int, error) {
 	nn := 0
 	for {
 		var n int
-		n, err = syscall.Write(fd.sysfile.Fd(), p[nn:])
+		n, err = syscall.Write(int(fd.sysfile.Fd()), p[nn:])
 		if n > 0 {
 			nn += n
 		}
@@ -615,7 +615,7 @@ func (fd *netFD) dup() (f *os.File, err error) {
 		return nil, &OpError{"setnonblock", fd.net, fd.laddr, err}
 	}
 
-	return os.NewFile(ns, fd.sysfile.Name()), nil
+	return os.NewFile(uintptr(ns), fd.sysfile.Name()), nil
 }
 
 func closesocket(s int) error {

src/pkg/net/file.go

@@ -12,7 +12,7 @@ import (
 )
 
 func newFileFD(f *os.File) (*netFD, error) {
-	fd, err := syscall.Dup(f.Fd())
+	fd, err := syscall.Dup(int(f.Fd()))
 	if err != nil {
 		return nil, os.NewSyscallError("dup", err)
 	}

src/pkg/net/newpollserver.go

@@ -18,16 +18,16 @@ func newPollServer() (s *pollServer, err error) {
 	if s.pr, s.pw, err = os.Pipe(); err != nil {
 		return nil, err
 	}
-	if err = syscall.SetNonblock(s.pr.Fd(), true); err != nil {
+	if err = syscall.SetNonblock(int(s.pr.Fd()), true); err != nil {
 		goto Errno
 	}
-	if err = syscall.SetNonblock(s.pw.Fd(), true); err != nil {
+	if err = syscall.SetNonblock(int(s.pw.Fd()), true); err != nil {
 		goto Errno
 	}
 	if s.poll, err = newpollster(); err != nil {
 		goto Error
 	}
-	if _, err = s.poll.AddFD(s.pr.Fd(), 'r', true); err != nil {
+	if _, err = s.poll.AddFD(int(s.pr.Fd()), 'r', true); err != nil {
 		s.poll.Close()
 		goto Error
 	}

src/pkg/net/sendfile_linux.go

@@ -42,7 +42,7 @@ func sendFile(c *netFD, r io.Reader) (written int64, err error, handled bool) {
 	defer c.decref()
 
 	dst := c.sysfd
-	src := f.Fd()
+	src := int(f.Fd())
 	for remain > 0 {
 		n := maxSendfileSize
 		if int64(n) > remain {

src/pkg/os/env.go

@@ -29,10 +29,10 @@ func Expand(s string, mapping func(string) string) string {
 	return string(buf) + s[i:]
 }
 
-// ShellExpand replaces ${var} or $var in the string according to the values
-// of the operating system's environment variables.  References to undefined
+// ExpandEnv replaces ${var} or $var in the string according to the values
+// of the current environment variables.  References to undefined
 // variables are replaced by the empty string.
-func ShellExpand(s string) string {
+func ExpandEnv(s string) string {
 	return Expand(s, Getenv)
 }
 
@@ -115,7 +115,7 @@ func Clearenv() {
 	syscall.Clearenv()
 }
 
-// Environ returns an array of strings representing the environment,
+// Environ returns a copy of strings representing the environment,
 // in the form "key=value".
 func Environ() []string {
 	return syscall.Environ()

src/pkg/os/error_posix.go

@@ -15,7 +15,6 @@ var (
 	ESRCH        error = syscall.ESRCH
 	EINTR        error = syscall.EINTR
 	EIO          error = syscall.EIO
-	ENXIO        error = syscall.ENXIO
 	E2BIG        error = syscall.E2BIG
 	ENOEXEC      error = syscall.ENOEXEC
 	EBADF        error = syscall.EBADF

src/pkg/os/exec/exec_test.go

@@ -153,7 +153,7 @@ func TestExtraFiles(t *testing.T) {
 
 	// Ensure that file descriptors have not already been leaked into
 	// our environment.
-	for fd := os.Stderr.Fd() + 1; fd <= 101; fd++ {
+	for fd := int(os.Stderr.Fd()) + 1; fd <= 101; fd++ {
 		err := syscall.Close(fd)
 		if err == nil {
 			t.Logf("Something already leaked - closed fd %d", fd)

src/pkg/os/exec_plan9.go

@@ -72,20 +72,6 @@ func (p *Process) Kill() error {
 	return e
 }
 
-// Exec replaces the current process with an execution of the
-// named binary, with arguments argv and environment envv.
-// If successful, Exec never returns.  If it fails, it returns an error.
-// ForkExec is almost always a better way to execute a program.
-// If there is an error, it will be of type *PathError.
-func Exec(name string, argv []string, envv []string) error {
-	e := syscall.Exec(name, argv, envv)
-	if e != nil {
-		return &PathError{"exec", name, e}
-	}
-
-	return nil
-}
-
 // Waitmsg stores the information about an exited process as reported by Wait.
 type Waitmsg struct {
 	syscall.Waitmsg

src/pkg/os/exec_posix.go

@@ -38,7 +38,7 @@ func StartProcess(name string, argv []string, attr *ProcAttr) (p *Process, err e
 		sysattr.Env = Environ()
 	}
 	for _, f := range attr.Files {
-		sysattr.Files = append(sysattr.Files, f.Fd())
+		sysattr.Files = append(sysattr.Files, int(f.Fd()))
 	}
 
 	pid, h, e := syscall.StartProcess(name, argv, sysattr)
@@ -53,25 +53,6 @@ func (p *Process) Kill() error {
 	return p.Signal(UnixSignal(syscall.SIGKILL))
 }
 
-// Exec replaces the current process with an execution of the
-// named binary, with arguments argv and environment envv.
-// If successful, Exec never returns.  If it fails, it returns an error.
-//
-// To run a child process, see StartProcess (for a low-level interface)
-// or the os/exec package (for higher-level interfaces).
-//
-// If there is an error, it will be of type *PathError.
-func Exec(name string, argv []string, envv []string) error {
-	if envv == nil {
-		envv = Environ()
-	}
-	e := syscall.Exec(name, argv, envv)
-	if e != nil {
-		return &PathError{"exec", name, e}
-	}
-	return nil
-}
-
 // TODO(rsc): Should os implement its own syscall.WaitStatus
 // wrapper with the methods, or is exposing the underlying one enough?
 //

src/pkg/os/file.go

@@ -25,26 +25,22 @@ func (f *File) Name() string { return f.name }
 // Stdin, Stdout, and Stderr are open Files pointing to the standard input,
 // standard output, and standard error file descriptors.
 var (
-	Stdin  = NewFile(syscall.Stdin, "/dev/stdin")
-	Stdout = NewFile(syscall.Stdout, "/dev/stdout")
-	Stderr = NewFile(syscall.Stderr, "/dev/stderr")
+	Stdin  = NewFile(uintptr(syscall.Stdin), "/dev/stdin")
+	Stdout = NewFile(uintptr(syscall.Stdout), "/dev/stdout")
+	Stderr = NewFile(uintptr(syscall.Stderr), "/dev/stderr")
 )
 
 // Flags to Open wrapping those of the underlying system. Not all flags
 // may be implemented on a given system.
 const (
-	O_RDONLY   int = syscall.O_RDONLY   // open the file read-only.
-	O_WRONLY   int = syscall.O_WRONLY   // open the file write-only.
-	O_RDWR     int = syscall.O_RDWR     // open the file read-write.
-	O_APPEND   int = syscall.O_APPEND   // append data to the file when writing.
-	O_ASYNC    int = syscall.O_ASYNC    // generate a signal when I/O is available.
-	O_CREATE   int = syscall.O_CREAT    // create a new file if none exists.
-	O_EXCL     int = syscall.O_EXCL     // used with O_CREATE, file must not exist
-	O_NOCTTY   int = syscall.O_NOCTTY   // do not make file the controlling tty.
-	O_NONBLOCK int = syscall.O_NONBLOCK // open in non-blocking mode.
-	O_NDELAY   int = O_NONBLOCK         // synonym for O_NONBLOCK
-	O_SYNC     int = syscall.O_SYNC     // open for synchronous I/O.
-	O_TRUNC    int = syscall.O_TRUNC    // if possible, truncate file when opened.
+	O_RDONLY int = syscall.O_RDONLY // open the file read-only.
+	O_WRONLY int = syscall.O_WRONLY // open the file write-only.
+	O_RDWR   int = syscall.O_RDWR   // open the file read-write.
+	O_APPEND int = syscall.O_APPEND // append data to the file when writing.
+	O_CREATE int = syscall.O_CREAT  // create a new file if none exists.
+	O_EXCL   int = syscall.O_EXCL   // used with O_CREATE, file must not exist
+	O_SYNC   int = syscall.O_SYNC   // open for synchronous I/O.
+	O_TRUNC  int = syscall.O_TRUNC  // if possible, truncate file when opened.
 )
 
 // Seek whence values.

src/pkg/os/file_unix.go

@@ -28,19 +28,20 @@ type file struct {
 }
 
 // Fd returns the integer Unix file descriptor referencing the open file.
-func (f *File) Fd() int {
+func (f *File) Fd() uintptr {
 	if f == nil {
-		return -1
+		return ^(uintptr(0))
 	}
-	return f.fd
+	return uintptr(f.fd)
 }
 
 // NewFile returns a new File with the given file descriptor and name.
-func NewFile(fd int, name string) *File {
-	if fd < 0 {
+func NewFile(fd uintptr, name string) *File {
+	fdi := int(fd)
+	if fdi < 0 {
 		return nil
 	}
-	f := &File{&file{fd: fd, name: name}}
+	f := &File{&file{fd: fdi, name: name}}
 	runtime.SetFinalizer(f.file, (*file).close)
 	return f
 }
@@ -78,7 +79,7 @@ func OpenFile(name string, flag int, perm FileMode) (file *File, err error) {
 		syscall.CloseOnExec(r)
 	}
 
-	return NewFile(r, name), nil
+	return NewFile(uintptr(r), name), nil
 }
 
 // Close closes the File, rendering it unusable for I/O.
@@ -114,10 +115,6 @@ func (f *File) Stat() (fi FileInfo, err error) {
 }
 
 // Stat returns a FileInfo describing the named file.
-// If name names a valid symbolic link, the returned FileInfo describes
-// the file pointed at by the link and has fi.FollowedSymlink set to true.
-// If name names an invalid symbolic link, the returned FileInfo describes
-// the link itself and has fi.FollowedSymlink set to false.
 // If there is an error, it will be of type *PathError.
 func Stat(name string) (fi FileInfo, err error) {
 	var stat syscall.Stat_t
@@ -268,7 +265,7 @@ func Pipe() (r *File, w *File, err error) {
 	syscall.CloseOnExec(p[1])
 	syscall.ForkLock.RUnlock()
 
-	return NewFile(p[0], "|0"), NewFile(p[1], "|1"), nil
+	return NewFile(uintptr(p[0]), "|0"), NewFile(uintptr(p[1]), "|1"), nil
 }
 
 // TempDir returns the default directory to use for temporary files.

src/pkg/os/file_windows.go

@@ -30,19 +30,20 @@ type file struct {
 }
 
 // Fd returns the Windows handle referencing the open file.
-func (file *File) Fd() syscall.Handle {
+func (file *File) Fd() uintptr {
 	if file == nil {
-		return syscall.InvalidHandle
+		return uintptr(syscall.InvalidHandle)
 	}
-	return file.fd
+	return uintptr(file.fd)
 }
 
 // NewFile returns a new File with the given file descriptor and name.
-func NewFile(fd syscall.Handle, name string) *File {
-	if fd == syscall.InvalidHandle {
+func NewFile(fd uintptr, name string) *File {
+	h := syscall.Handle(fd)
+	if h == syscall.InvalidHandle {
 		return nil
 	}
-	f := &File{&file{fd: fd, name: name}}
+	f := &File{&file{fd: h, name: name}}
 	runtime.SetFinalizer(f.file, (*file).close)
 	return f
 }

src/pkg/os/stat_windows.go

@@ -29,10 +29,6 @@ func (file *File) Stat() (fi FileInfo, err error) {
 }
 
 // Stat returns a FileInfo structure describing the named file.
-// If name names a valid symbolic link, the returned FileInfo describes
-// the file pointed at by the link and has fi.FollowedSymlink set to true.
-// If name names an invalid symbolic link, the returned FileInfo describes
-// the link itself and has fi.FollowedSymlink set to false.
 // If there is an error, it will be of type *PathError.
 func Stat(name string) (fi FileInfo, err error) {
 	if len(name) == 0 {