os: Plan 9, fix OpenFile & Chmod. Update tests.

Add Process.Kill.

R=rsc
CC=golang-dev
https://golang.org/cl/4571049

src/pkg/os/Makefile

@@ -73,6 +73,7 @@ GOFILES_plan9=\
 	path_plan9.go\
 	sys_plan9.go\
 	exec_plan9.go\
+	str.go\
 
 GOFILES+=$(GOFILES_$(GOOS))
 

src/pkg/os/exec_plan9.go

@@ -38,6 +38,17 @@ func StartProcess(name string, argv []string, attr *ProcAttr) (p *Process, err E
 	return newProcess(pid, h), nil
 }
 
+// Kill causes the Process to exit immediately.
+func (p *Process) Kill() Error {
+	f, e := OpenFile("/proc/"+itoa(p.Pid)+"/ctl", O_WRONLY, 0)
+	if iserror(e) {
+		return NewSyscallError("kill", e)
+	}
+	defer f.Close()
+	_, e = f.Write([]byte("kill"))
+	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.

src/pkg/os/file_plan9.go

@@ -30,14 +30,43 @@ const DevNull = "/dev/null"
 // methods on the returned File can be used for I/O.
 // It returns the File and an Error, if any.
 func OpenFile(name string, flag int, perm uint32) (file *File, err Error) {
-	var fd int
-	var e syscall.Error
+	var (
+		fd     int
+		e      syscall.Error
+		create bool
+		excl   bool
+		trunc  bool
+		append bool
+	)
+
+	if flag&O_CREATE == O_CREATE {
+		flag = flag & ^O_CREATE
+		create = true
+	}
+	if flag&O_EXCL == O_EXCL {
+		excl = true
+	}
+	if flag&O_TRUNC == O_TRUNC {
+		trunc = true
+	}
+	// O_APPEND is emulated on Plan 9
+	if flag&O_APPEND == O_APPEND {
+		flag = flag &^ O_APPEND
+		append = true
+	}
 
 	syscall.ForkLock.RLock()
-	if flag&O_CREATE == O_CREATE {
-		fd, e = syscall.Create(name, flag & ^O_CREATE, perm)
+	if (create && trunc) || excl {
+		fd, e = syscall.Create(name, flag, perm)
 	} else {
 		fd, e = syscall.Open(name, flag)
+		if e != nil && create {
+			var e1 syscall.Error
+			fd, e1 = syscall.Create(name, flag, perm)
+			if e1 == nil {
+				e = nil
+			}
+		}
 	}
 	syscall.ForkLock.RUnlock()
 
@@ -45,6 +74,12 @@ func OpenFile(name string, flag int, perm uint32) (file *File, err Error) {
 		return nil, &PathError{"open", name, e}
 	}
 
+	if append {
+		if _, e = syscall.Seek(fd, 0, SEEK_END); e != nil {
+			return nil, &PathError{"seek", name, e}
+		}
+	}
+
 	return NewFile(fd, name), nil
 }
 
@@ -69,8 +104,12 @@ func (file *File) Close() Error {
 
 // Stat returns the FileInfo structure describing file.
 // It returns the FileInfo and an error, if any.
-func (file *File) Stat() (fi *FileInfo, err Error) {
-	return dirstat(file)
+func (f *File) Stat() (fi *FileInfo, err Error) {
+	d, err := dirstat(f)
+	if iserror(err) {
+		return nil, err
+	}
+	return fileInfoFromStat(new(FileInfo), d), err
 }
 
 // Truncate changes the size of the file.
@@ -90,10 +129,15 @@ func (f *File) Truncate(size int64) Error {
 // Chmod changes the mode of the file to mode.
 func (f *File) Chmod(mode uint32) Error {
 	var d Dir
+	var mask = ^uint32(0777)
+
 	d.Null()
+	odir, e := dirstat(f)
+	if iserror(e) {
+		return &PathError{"chmod", f.name, e}
+	}
 
-	d.Mode = mode & 0777
-
+	d.Mode = (odir.Mode & mask) | (mode &^ mask)
 	if e := syscall.Fwstat(f.fd, pdir(nil, &d)); iserror(e) {
 		return &PathError{"chmod", f.name, e}
 	}
@@ -188,10 +232,15 @@ func Rename(oldname, newname string) Error {
 // Chmod changes the mode of the named file to mode.
 func Chmod(name string, mode uint32) Error {
 	var d Dir
+	var mask = ^uint32(0777)
+
 	d.Null()
+	odir, e := dirstat(name)
+	if iserror(e) {
+		return &PathError{"chmod", name, e}
+	}
 
-	d.Mode = mode & 0777
-
+	d.Mode = (odir.Mode & mask) | (mode &^ mask)
 	if e := syscall.Wstat(name, pdir(nil, &d)); iserror(e) {
 		return &PathError{"chmod", name, e}
 	}

src/pkg/os/os_test.go

@@ -359,8 +359,8 @@ func TestReaddirNValues(t *testing.T) {
 }
 
 func TestHardLink(t *testing.T) {
-	// Hardlinks are not supported under windows.
-	if syscall.OS == "windows" {
+	// Hardlinks are not supported under windows or Plan 9.
+	if syscall.OS == "windows" || syscall.OS == "plan9" {
 		return
 	}
 	from, to := "hardlinktestfrom", "hardlinktestto"
@@ -392,8 +392,8 @@ func TestHardLink(t *testing.T) {
 }
 
 func TestSymLink(t *testing.T) {
-	// Symlinks are not supported under windows.
-	if syscall.OS == "windows" {
+	// Symlinks are not supported under windows or Plan 9.
+	if syscall.OS == "windows" || syscall.OS == "plan9" {
 		return
 	}
 	from, to := "symlinktestfrom", "symlinktestto"
@@ -454,8 +454,8 @@ func TestSymLink(t *testing.T) {
 }
 
 func TestLongSymlink(t *testing.T) {
-	// Symlinks are not supported under windows.
-	if syscall.OS == "windows" {
+	// Symlinks are not supported under windows or Plan 9.
+	if syscall.OS == "windows" || syscall.OS == "plan9" {
 		return
 	}
 	s := "0123456789abcdef"
@@ -588,8 +588,9 @@ func checkUidGid(t *testing.T, path string, uid, gid int) {
 }
 
 func TestChown(t *testing.T) {
-	// Chown is not supported under windows.
-	if syscall.OS == "windows" {
+	// Chown is not supported under windows or Plan 9.
+	// Plan9 provides a native ChownPlan9 version instead.
+	if syscall.OS == "windows" || syscall.OS == "plan9" {
 		return
 	}
 	// Use TempDir() to make sure we're on a local file system,
@@ -708,7 +709,11 @@ func TestChtimes(t *testing.T) {
 		t.Fatalf("second Stat %s: %s", f.Name(), err)
 	}
 
-	if postStat.Atime_ns >= preStat.Atime_ns {
+	/* Plan 9:
+		Mtime is the time of the last change of content.  Similarly, atime is set whenever the
+	    contents are accessed; also, it is set whenever mtime is set.
+	*/
+	if postStat.Atime_ns >= preStat.Atime_ns && syscall.OS != "plan9" {
 		t.Errorf("Atime_ns didn't go backwards; was=%d, after=%d",
 			preStat.Atime_ns,
 			postStat.Atime_ns)
@@ -733,6 +738,10 @@ func TestChdirAndGetwd(t *testing.T) {
 	// These are chosen carefully not to be symlinks on a Mac
 	// (unlike, say, /var, /etc, and /tmp).
 	dirs := []string{"/", "/usr/bin"}
+	// /usr/bin does not usually exist on Plan 9.
+	if syscall.OS == "plan9" {
+		dirs = []string{"/", "/usr"}
+	}
 	for mode := 0; mode < 2; mode++ {
 		for _, d := range dirs {
 			if mode == 0 {
@@ -858,7 +867,15 @@ func TestOpenError(t *testing.T) {
 			t.Errorf("Open(%q, %d) returns error of %T type; want *os.PathError", tt.path, tt.mode, err)
 		}
 		if perr.Error != tt.error {
-			t.Errorf("Open(%q, %d) = _, %q; want %q", tt.path, tt.mode, perr.Error.String(), tt.error.String())
+			if syscall.OS == "plan9" {
+				syscallErrStr := perr.Error.String()
+				expectedErrStr := strings.Replace(tt.error.String(), "file ", "", 1)
+				if !strings.HasSuffix(syscallErrStr, expectedErrStr) {
+					t.Errorf("Open(%q, %d) = _, %q; want suffix %q", tt.path, tt.mode, syscallErrStr, expectedErrStr)
+				}
+			} else {
+				t.Errorf("Open(%q, %d) = _, %q; want %q", tt.path, tt.mode, perr.Error.String(), tt.error.String())
+			}
 		}
 	}
 }
@@ -893,7 +910,8 @@ func run(t *testing.T, cmd []string) string {
 
 func TestHostname(t *testing.T) {
 	// There is no other way to fetch hostname on windows, but via winapi.
-	if syscall.OS == "windows" {
+	// On Plan 9 it is can be taken from #c/sysname as Hostname() does.
+	if syscall.OS == "windows" || syscall.OS == "plan9" {
 		return
 	}
 	// Check internal Hostname() against the output of /bin/hostname.

src/pkg/os/path_test.go

@@ -166,8 +166,8 @@ func TestRemoveAll(t *testing.T) {
 }
 
 func TestMkdirAllWithSymlink(t *testing.T) {
-	if runtime.GOOS == "windows" {
-		t.Log("Skipping test: symlinks don't exist under Windows")
+	if runtime.GOOS == "windows" || runtime.GOOS == "plan9" {
+		t.Log("Skipping test: symlinks don't exist under Windows/Plan 9")
 		return
 	}
 
@@ -191,7 +191,7 @@ func TestMkdirAllWithSymlink(t *testing.T) {
 }
 
 func TestMkdirAllAtSlash(t *testing.T) {
-	if runtime.GOOS == "windows" {
+	if runtime.GOOS == "windows" || runtime.GOOS == "plan9" {
 		return
 	}
 	RemoveAll("/_go_os_test")

src/pkg/os/stat_plan9.go

@@ -26,7 +26,7 @@ func fileInfoFromStat(fi *FileInfo, d *Dir) *FileInfo {
 }
 
 // arg is an open *File or a path string. 
-func dirstat(arg interface{}) (fi *FileInfo, err Error) {
+func dirstat(arg interface{}) (d *Dir, err Error) {
 	var name string
 	nd := syscall.STATFIXLEN + 16*4
 
@@ -62,8 +62,7 @@ func dirstat(arg interface{}) (fi *FileInfo, err Error) {
 			if e != nil {
 				return nil, &PathError{"stat", name, e}
 			}
-
-			return fileInfoFromStat(new(FileInfo), d), nil
+			return d, e
 		}
 	}
 
@@ -73,12 +72,20 @@ func dirstat(arg interface{}) (fi *FileInfo, err Error) {
 
 // Stat returns a FileInfo structure describing the named file and an error, if any.
 func Stat(name string) (fi *FileInfo, err Error) {
-	return dirstat(name)
+	d, err := dirstat(name)
+	if iserror(err) {
+		return nil, err
+	}
+	return fileInfoFromStat(new(FileInfo), d), err
 }
 
 // Lstat returns the FileInfo structure describing the named file and an
 // error, if any.  If the file is a symbolic link (though Plan 9 does not have symbolic links), 
 // the returned FileInfo describes the symbolic link.  Lstat makes no attempt to follow the link.
 func Lstat(name string) (fi *FileInfo, err Error) {
-	return dirstat(name)
+	d, err := dirstat(name)
+	if iserror(err) {
+		return nil, err
+	}
+	return fileInfoFromStat(new(FileInfo), d), err
 }

src/pkg/os/str.go

@@ -0,0 +1,20 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package os
+
+func itoa(val int) string { // do it here rather than with fmt to avoid dependency
+	if val < 0 {
+		return "-" + itoa(-val)
+	}
+	var buf [32]byte // big enough for int64
+	i := len(buf) - 1
+	for val >= 10 {
+		buf[i] = byte(val%10 + '0')
+		i--
+		val /= 10
+	}
+	buf[i] = byte(val + '0')
+	return string(buf[i:])
+}

src/pkg/syscall/types_plan9.c

@@ -19,20 +19,18 @@ enum {
 	OREAD	= 0,	// open for read
 	OWRITE	= 1,	// write
 	ORDWR	= 2,	// read and write
+	OEXEC	= 3,	// execute, == read but check execute permission
+	OTRUNC	= 16,	// or'ed in (except for exec), truncate file first
+	OCEXEC	= 32,	// or'ed in, close on exec
+	ORCLOSE	= 64,		// or'ed in, remove on close
+	OEXCL	= 0x1000,	// or'ed in, exclusive use (create only)
 
 	$O_RDONLY	= OREAD,
 	$O_WRONLY	= OWRITE,
 	$O_RDWR		= ORDWR,
-
-	OEXEC	= 3,	// execute, == read but check execute permission
-	OTRUNC	= 16,	// or'ed in (except for exec), truncate file first
-	OCEXEC	= 32,	// or'ed in, close on exec
-
-	$O_CLOEXEC  = OCEXEC,
-
-	ORCLOSE	= 64,		// or'ed in, remove on close
-	OEXCL	= 0x1000,	// or'ed in, exclusive use (create only)
-	$O_EXCL	= OEXCL,
+	$O_TRUNC	= OTRUNC,
+	$O_CLOEXEC	= OCEXEC,
+	$O_EXCL		= OEXCL,
 
 	$STATMAX	= 65535U,
 	$ERRMAX		= 128,

src/pkg/syscall/zerrors_plan9_386.go

@@ -4,10 +4,9 @@ package syscall
 const (
 	// Invented values to support what package os expects.
 	O_CREAT    = 0x02000
+	O_APPEND   = 0x00400
 	O_NOCTTY   = 0x00000
-	O_TRUNC    = 0x00000
 	O_NONBLOCK = 0x00000
-	O_APPEND   = 0x00000
 	O_SYNC     = 0x00000
 	O_ASYNC    = 0x00000
 

src/pkg/syscall/ztypes_plan9_386.go

@@ -9,6 +9,7 @@ const (
 	O_RDONLY   = 0
 	O_WRONLY   = 0x1
 	O_RDWR     = 0x2
+	O_TRUNC    = 0x10
 	O_CLOEXEC  = 0x20
 	O_EXCL     = 0x1000
 	STATMAX    = 0xffff