syscall: take over env implementation

The environment is needed by package time, which
we want not to depend on os (so that os can use
time.Time), so push down into syscall.

Delete syscall.Sleep, now unnecessary.

The package os environment API is preserved;
it is only the implementation that is moving to syscall.

Delete os.Envs, which was undocumented,
uninitialized on Windows and Plan 9, and
not maintained by Setenv and Clearenv.
Code can call os.Environ instead.

R=golang-dev, r
CC=golang-dev
https://golang.org/cl/5370091

src/pkg/os/Makefile

@@ -20,7 +20,6 @@ GOFILES=\
 GOFILES_freebsd=\
 	dir_unix.go\
 	error_posix.go\
-	env_unix.go\
 	file_posix.go\
 	file_unix.go\
 	path_unix.go\
@@ -32,7 +31,6 @@ GOFILES_freebsd=\
 GOFILES_darwin=\
 	dir_unix.go\
 	error_posix.go\
-	env_unix.go\
 	file_posix.go\
 	file_unix.go\
 	path_unix.go\
@@ -44,7 +42,6 @@ GOFILES_darwin=\
 GOFILES_linux=\
 	dir_unix.go\
 	error_posix.go\
-	env_unix.go\
 	file_posix.go\
 	file_unix.go\
 	path_unix.go\
@@ -56,7 +53,6 @@ GOFILES_linux=\
 GOFILES_openbsd=\
 	dir_unix.go\
 	error_posix.go\
-	env_unix.go\
 	file_posix.go\
 	file_unix.go\
 	path_unix.go\
@@ -68,7 +64,6 @@ GOFILES_openbsd=\
 GOFILES_windows=\
 	dir_windows.go\
 	error_posix.go\
-	env_windows.go\
 	file_posix.go\
 	file_windows.go\
 	path_windows.go\
@@ -80,7 +75,6 @@ GOFILES_windows=\
 GOFILES_plan9=\
 	dir_plan9.go\
 	error_plan9.go\
-	env_plan9.go\
 	file_plan9.go\
 	path_plan9.go\
 	sys_plan9.go\

src/pkg/os/env.go

@@ -6,7 +6,10 @@
 
 package os
 
-func setenv_c(k, v string)
+import (
+	"errors"
+	"syscall"
+)
 
 // Expand replaces ${var} or $var in the string based on the mapping function.
 // Invocations of undefined variables are replaced with the empty string.
@@ -73,3 +76,47 @@ func getShellName(s string) (string, int) {
 	}
 	return s[:i], i
 }
+
+// ENOENV is the error indicating that an environment variable does not exist.
+var ENOENV = errors.New("no such environment variable")
+
+// Getenverror retrieves the value of the environment variable named by the key.
+// It returns the value and an error, if any.
+func Getenverror(key string) (value string, err error) {
+	if len(key) == 0 {
+		return "", EINVAL
+	}
+	val, found := syscall.Getenv(key)
+	if !found {
+		return "", ENOENV
+	}
+	return val, nil
+}
+
+// Getenv retrieves the value of the environment variable named by the key.
+// It returns the value, which will be empty if the variable is not present.
+func Getenv(key string) string {
+	v, _ := Getenverror(key)
+	return v
+}
+
+// Setenv sets the value of the environment variable named by the key.
+// It returns an error, if any.
+func Setenv(key, value string) error {
+	err := syscall.Setenv(key, value)
+	if err != nil {
+		return NewSyscallError("setenv", err)
+	}
+	return nil
+}
+
+// Clearenv deletes all environment variables.
+func Clearenv() {
+	syscall.Clearenv()
+}
+
+// Environ returns an array of strings representing the environment,
+// in the form "key=value".
+func Environ() []string {
+	return syscall.Environ()
+}

src/pkg/os/exec_windows.go

@@ -65,3 +65,17 @@ func FindProcess(pid int) (p *Process, err error) {
 	}
 	return newProcess(pid, int(h)), nil
 }
+
+func init() {
+	var argc int32
+	cmd := GetCommandLine()
+	argv, e := CommandLineToArgv(cmd, &argc)
+	if e != nil {
+		return
+	}
+	defer LocalFree(Handle(uintptr(unsafe.Pointer(argv))))
+	Args = make([]string, argc)
+	for i, v := range (*argv)[:argc] {
+		Args[i] = string(UTF16ToString((*v)[:]))
+	}
+}

src/pkg/os/file_plan9.go

@@ -329,3 +329,8 @@ func Lchown(name string, uid, gid int) error {
 func (f *File) Chown(uid, gid int) error {
 	return EPLAN9
 }
+
+// TempDir returns the default directory to use for temporary files.
+func TempDir() string {
+	return "/tmp"
+}

src/pkg/os/file_unix.go

@@ -241,3 +241,12 @@ func Pipe() (r *File, w *File, err error) {
 
 	return NewFile(p[0], "|0"), NewFile(p[1], "|1"), nil
 }
+
+// TempDir returns the default directory to use for temporary files.
+func TempDir() string {
+	dir := Getenv("TMPDIR")
+	if dir == "" {
+		dir = "/tmp"
+	}
+	return dir
+}

src/pkg/os/file_windows.go

@@ -283,3 +283,21 @@ func Pipe() (r *File, w *File, err error) {
 
 	return NewFile(p[0], "|0"), NewFile(p[1], "|1"), nil
 }
+
+// TempDir returns the default directory to use for temporary files.
+func TempDir() string {
+	const pathSep = '\\'
+	dirw := make([]uint16, MAX_PATH)
+	n, _ := syscall.GetTempPath(uint32(len(dirw)), &dirw[0])
+	if n > uint32(len(dirw)) {
+		dirw = make([]uint16, n)
+		n, _ = syscall.GetTempPath(uint32(len(dirw)), &dirw[0])
+		if n > uint32(len(dirw)) {
+			n = 0
+		}
+	}
+	if n > 0 && dirw[n-1] == pathSep {
+		n--
+	}
+	return string(utf16.Decode(dirw[0:n]))
+}

src/pkg/os/os_test.go

@@ -18,7 +18,7 @@ import (
 
 var dot = []string{
 	"dir_unix.go",
-	"env_unix.go",
+	"env.go",
 	"error.go",
 	"file.go",
 	"os_test.go",

src/pkg/os/proc.go

@@ -8,8 +8,8 @@ package os
 
 import "syscall"
 
-var Args []string // provided by runtime
-var Envs []string // provided by runtime
+// Args is the command-line arguments, starting with the program name.
+var Args []string
 
 // Getuid returns the numeric user id of the caller.
 func Getuid() int { return syscall.Getuid() }

src/pkg/runtime/proc.c

@@ -1723,9 +1723,9 @@ runtime·setcpuprofilerate(void (*fn)(uintptr*, int32), int32 hz)
 void (*libcgo_setenv)(byte**);
 
 // Update the C environment if cgo is loaded.
-// Called from os.Setenv.
+// Called from syscall.Setenv.
 void
-os·setenv_c(String k, String v)
+syscall·setenv_c(String k, String v)
 {
 	byte *arg[2];
 

src/pkg/runtime/runtime.c

@@ -172,7 +172,7 @@ static int32	argc;
 static uint8**	argv;
 
 Slice os·Args;
-Slice os·Envs;
+Slice syscall·envs;
 
 void
 runtime·args(int32 c, uint8 **v)
@@ -214,9 +214,9 @@ runtime·goenvs_unix(void)
 	s = runtime·malloc(n*sizeof s[0]);
 	for(i=0; i<n; i++)
 		s[i] = runtime·gostringnocopy(argv[argc+1+i]);
-	os·Envs.array = (byte*)s;
-	os·Envs.len = n;
-	os·Envs.cap = n;
+	syscall·envs.array = (byte*)s;
+	syscall·envs.len = n;
+	syscall·envs.cap = n;
 }
 
 byte*
@@ -229,8 +229,8 @@ runtime·getenv(int8 *s)
 
 	bs = (byte*)s;
 	len = runtime·findnull(bs);
-	envv = (String*)os·Envs.array;
-	envc = os·Envs.len;
+	envv = (String*)syscall·envs.array;
+	envc = syscall·envs.len;
 	for(i=0; i<envc; i++){
 		if(envv[i].len <= len)
 			continue;

src/pkg/syscall/Makefile

@@ -18,6 +18,7 @@ GOFILES=\
 
 GOFILES_freebsd=\
 	bpf_bsd.go\
+	env_unix.go\
 	exec_unix.go\
 	route_bsd.go\
 	route_freebsd.go\
@@ -27,6 +28,7 @@ GOFILES_freebsd=\
 
 GOFILES_darwin=\
 	bpf_bsd.go\
+	env_unix.go\
 	exec_unix.go\
 	route_bsd.go\
 	route_darwin.go\
@@ -35,6 +37,7 @@ GOFILES_darwin=\
 	syscall_unix.go\
 
 GOFILES_linux=\
+	env_unix.go\
 	exec_unix.go\
 	lsf_linux.go\
 	netlink_linux.go\
@@ -44,6 +47,7 @@ GOFILES_linux=\
 
 GOFILES_openbsd=\
 	bpf_bsd.go\
+	env_unix.go\
 	exec_unix.go\
 	route_bsd.go\
 	route_openbsd.go\
@@ -52,12 +56,14 @@ GOFILES_openbsd=\
 	syscall_unix.go\
 
 GOFILES_windows=\
+	env_windows.go\
 	exec_windows.go\
 	dll_windows.go\
 	zerrors_windows.go\
 	ztypes_windows.go\
 
 GOFILES_plan9=\
+	env_plan9.go\
 	exec_plan9.go\
 
 OFILES=\

src/pkg/os/env_plan9.go → src/pkg/syscall/env_plan9.go

@@ -4,19 +4,11 @@
 
 // Plan 9 environment variables.
 
-package os
+package syscall
 
-import (
-	"errors"
-	"syscall"
-)
+import "errors"
 
-// ENOENV is the error indicating that an environment variable does not exist.
-var ENOENV = errors.New("no such environment variable")
-
-// Getenverror retrieves the value of the environment variable named by the key.
-// It returns the value and an error, if any.
-func Getenverror(key string) (value string, err error) {
+func Getenv(key string) (value string, found bool) {
 	if len(key) == 0 {
 		return "", EINVAL
 	}
@@ -40,15 +32,6 @@ func Getenverror(key string) (value string, err error) {
 	return string(buf), nil
 }
 
-// Getenv retrieves the value of the environment variable named by the key.
-// It returns the value, which will be empty if the variable is not present.
-func Getenv(key string) string {
-	v, _ := Getenverror(key)
-	return v
-}
-
-// Setenv sets the value of the environment variable named by the key.
-// It returns an error, if any.
 func Setenv(key, value string) error {
 	if len(key) == 0 {
 		return EINVAL
@@ -64,13 +47,10 @@ func Setenv(key, value string) error {
 	return nil
 }
 
-// Clearenv deletes all environment variables.
 func Clearenv() {
-	syscall.RawSyscall(syscall.SYS_RFORK, syscall.RFCENVG, 0, 0)
+	RawSyscall(SYS_RFORK, RFCENVG, 0, 0)
 }
 
-// Environ returns an array of strings representing the environment,
-// in the form "key=value".
 func Environ() []string {
 	env := make([]string, 0, 100)
 
@@ -86,14 +66,9 @@ func Environ() []string {
 	}
 
 	for _, k := range names {
-		if v, e := Getenverror(k); e == nil {
+		if v, ok := Getenv(k); ok {
 			env = append(env, k+"="+v)
 		}
 	}
 	return env[0:len(env)]
 }
-
-// TempDir returns the default directory to use for temporary files.
-func TempDir() string {
-	return "/tmp"
-}

src/pkg/os/env_unix.go → src/pkg/syscall/env_unix.go

@@ -6,22 +6,19 @@
 
 // Unix environment variables.
 
-package os
+package syscall
 
-import (
-	"errors"
-	"sync"
-)
-
-// ENOENV is the error indicating that an environment variable does not exist.
-var ENOENV = errors.New("no such environment variable")
+import "sync"
 
 var env map[string]string
-var once sync.Once
+var envOnce sync.Once
+var envs []string // provided by runtime
+
+func setenv_c(k, v string)
 
 func copyenv() {
 	env = make(map[string]string)
-	for _, s := range Envs {
+	for _, s := range envs {
 		for j := 0; j < len(s); j++ {
 			if s[j] == '=' {
 				env[s[0:j]] = s[j+1:]
@@ -33,13 +30,10 @@ func copyenv() {
 
 var envLock sync.RWMutex
 
-// Getenverror retrieves the value of the environment variable named by the key.
-// It returns the value and an error, if any.
-func Getenverror(key string) (value string, err error) {
-	once.Do(copyenv)
-
+func Getenv(key string) (value string, found bool) {
+	envOnce.Do(copyenv)
 	if len(key) == 0 {
-		return "", EINVAL
+		return "", false
 	}
 
 	envLock.RLock()
@@ -47,22 +41,13 @@ func Getenverror(key string) (value string, err error) {
 
 	v, ok := env[key]
 	if !ok {
-		return "", ENOENV
+		return "", false
 	}
-	return v, nil
-}
-
-// Getenv retrieves the value of the environment variable named by the key.
-// It returns the value, which will be empty if the variable is not present.
-func Getenv(key string) string {
-	v, _ := Getenverror(key)
-	return v
+	return v, true
 }
 
-// Setenv sets the value of the environment variable named by the key.
-// It returns an error, if any.
 func Setenv(key, value string) error {
-	once.Do(copyenv)
+	envOnce.Do(copyenv)
 	if len(key) == 0 {
 		return EINVAL
 	}
@@ -75,9 +60,8 @@ func Setenv(key, value string) error {
 	return nil
 }
 
-// Clearenv deletes all environment variables.
 func Clearenv() {
-	once.Do(copyenv) // prevent copyenv in Getenv/Setenv
+	envOnce.Do(copyenv) // prevent copyenv in Getenv/Setenv
 
 	envLock.Lock()
 	defer envLock.Unlock()
@@ -87,10 +71,8 @@ func Clearenv() {
 	// TODO(bradfitz): pass through to C
 }
 
-// Environ returns an array of strings representing the environment,
-// in the form "key=value".
 func Environ() []string {
-	once.Do(copyenv)
+	envOnce.Do(copyenv)
 	envLock.RLock()
 	defer envLock.RUnlock()
 	a := make([]string, len(env))
@@ -101,12 +83,3 @@ func Environ() []string {
 	}
 	return a
 }
-
-// TempDir returns the default directory to use for temporary files.
-func TempDir() string {
-	dir := Getenv("TMPDIR")
-	if dir == "" {
-		dir = "/tmp"
-	}
-	return dir
-}

src/pkg/os/env_windows.go → src/pkg/syscall/env_windows.go

@@ -4,61 +4,45 @@
 
 // Windows environment variables.
 
-package os
+package syscall
 
 import (
 	"errors"
-	"syscall"
 	"unicode/utf16"
 	"unsafe"
 )
 
-// ENOENV is the error indicating that an environment variable does not exist.
-var ENOENV = errors.New("no such environment variable")
-
-// Getenverror retrieves the value of the environment variable named by the key.
-// It returns the value and an error, if any.
-func Getenverror(key string) (value string, err error) {
+func Getenv(key string) (value string, found bool) {
 	b := make([]uint16, 100)
-	n, e := syscall.GetEnvironmentVariable(syscall.StringToUTF16Ptr(key), &b[0], uint32(len(b)))
-	if n == 0 && e == syscall.ERROR_ENVVAR_NOT_FOUND {
-		return "", ENOENV
+	n, e := GetEnvironmentVariable(StringToUTF16Ptr(key), &b[0], uint32(len(b)))
+	if n == 0 && e == ERROR_ENVVAR_NOT_FOUND {
+		return "", false
 	}
 	if n > uint32(len(b)) {
 		b = make([]uint16, n)
-		n, e = syscall.GetEnvironmentVariable(syscall.StringToUTF16Ptr(key), &b[0], uint32(len(b)))
+		n, e = GetEnvironmentVariable(StringToUTF16Ptr(key), &b[0], uint32(len(b)))
 		if n > uint32(len(b)) {
 			n = 0
 		}
 	}
 	if n == 0 {
-		return "", NewSyscallError("GetEnvironmentVariable", e)
+		return "", false
 	}
-	return string(utf16.Decode(b[0:n])), nil
-}
-
-// Getenv retrieves the value of the environment variable named by the key.
-// It returns the value, which will be empty if the variable is not present.
-func Getenv(key string) string {
-	v, _ := Getenverror(key)
-	return v
+	return string(utf16.Decode(b[0:n])), true
 }
 
-// Setenv sets the value of the environment variable named by the key.
-// It returns an error, if any.
 func Setenv(key, value string) error {
 	var v *uint16
 	if len(value) > 0 {
-		v = syscall.StringToUTF16Ptr(value)
+		v = StringToUTF16Ptr(value)
 	}
-	e := syscall.SetEnvironmentVariable(syscall.StringToUTF16Ptr(key), v)
+	e := SetEnvironmentVariable(StringToUTF16Ptr(key), v)
 	if e != nil {
-		return NewSyscallError("SetEnvironmentVariable", e)
+		return e
 	}
 	return nil
 }
 
-// Clearenv deletes all environment variables.
 func Clearenv() {
 	for _, s := range Environ() {
 		// Environment variables can begin with =
@@ -73,14 +57,12 @@ func Clearenv() {
 	}
 }
 
-// Environ returns an array of strings representing the environment,
-// in the form "key=value".
 func Environ() []string {
-	s, e := syscall.GetEnvironmentStrings()
+	s, e := GetEnvironmentStrings()
 	if e != nil {
 		return nil
 	}
-	defer syscall.FreeEnvironmentStrings(s)
+	defer FreeEnvironmentStrings(s)
 	r := make([]string, 0, 50) // Empty with room to grow.
 	for from, i, p := 0, 0, (*[1 << 24]uint16)(unsafe.Pointer(s)); true; i++ {
 		if p[i] == 0 {
@@ -94,35 +76,3 @@ func Environ() []string {
 	}
 	return r
 }
-
-// TempDir returns the default directory to use for temporary files.
-func TempDir() string {
-	const pathSep = '\\'
-	dirw := make([]uint16, syscall.MAX_PATH)
-	n, _ := syscall.GetTempPath(uint32(len(dirw)), &dirw[0])
-	if n > uint32(len(dirw)) {
-		dirw = make([]uint16, n)
-		n, _ = syscall.GetTempPath(uint32(len(dirw)), &dirw[0])
-		if n > uint32(len(dirw)) {
-			n = 0
-		}
-	}
-	if n > 0 && dirw[n-1] == pathSep {
-		n--
-	}
-	return string(utf16.Decode(dirw[0:n]))
-}
-
-func init() {
-	var argc int32
-	cmd := syscall.GetCommandLine()
-	argv, e := syscall.CommandLineToArgv(cmd, &argc)
-	if e != nil {
-		return
-	}
-	defer syscall.LocalFree(syscall.Handle(uintptr(unsafe.Pointer(argv))))
-	Args = make([]string, argc)
-	for i, v := range (*argv)[:argc] {
-		Args[i] = string(syscall.UTF16ToString((*v)[:]))
-	}
-}

src/pkg/syscall/syscall_bsd.go

@@ -137,11 +137,6 @@ func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int,
 	return
 }
 
-func Sleep(ns int64) (err error) {
-	tv := NsecToTimeval(ns)
-	return Select(0, nil, nil, nil, &tv)
-}
-
 //sys	accept(s int, rsa *RawSockaddrAny, addrlen *_Socklen) (fd int, err error)
 //sys	bind(s int, addr uintptr, addrlen _Socklen) (err error)
 //sys	connect(s int, addr uintptr, addrlen _Socklen) (err error)

src/pkg/syscall/syscall_linux.go

@@ -184,12 +184,6 @@ func Wait4(pid int, wstatus *WaitStatus, options int, rusage *Rusage) (wpid int,
 	return
 }
 
-func Sleep(nsec int64) (err error) {
-	tv := NsecToTimeval(nsec)
-	_, err = Select(0, nil, nil, nil, &tv)
-	return err
-}
-
 func Mkfifo(path string, mode uint32) (err error) {
 	return Mknod(path, mode|S_IFIFO, 0)
 }

src/pkg/syscall/syscall_plan9.go

@@ -163,11 +163,6 @@ func Pipe(p []int) (err Error) {
 	return
 }
 
-//sys	sleep(millisecs int32) (err Error)
-func Sleep(nsec int64) (err Error) {
-	return sleep(int32((nsec + 999) / 1e6)) // round up to microsecond
-}
-
 // Underlying system call writes to newoffset via pointer.
 // Implemented in assembly to avoid allocation.
 func seek(placeholder uintptr, fd int, offset int64, whence int) (newoffset int64, err string)

src/pkg/syscall/syscall_windows.go

@@ -110,7 +110,6 @@ func NewCallback(fn interface{}) uintptr
 //sys	GetComputerName(buf *uint16, n *uint32) (err error) = GetComputerNameW
 //sys	SetEndOfFile(handle Handle) (err error)
 //sys	GetSystemTimeAsFileTime(time *Filetime)
-//sys	sleep(msec uint32) = Sleep
 //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
 //sys	CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (handle Handle, err error)
 //sys	GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) (err error)

src/pkg/syscall/zsyscall_windows_386.go

@@ -41,7 +41,6 @@ var (
 	procGetComputerNameW            = modkernel32.NewProc("GetComputerNameW")
 	procSetEndOfFile                = modkernel32.NewProc("SetEndOfFile")
 	procGetSystemTimeAsFileTime     = modkernel32.NewProc("GetSystemTimeAsFileTime")
-	procSleep                       = modkernel32.NewProc("Sleep")
 	procGetTimeZoneInformation      = modkernel32.NewProc("GetTimeZoneInformation")
 	procCreateIoCompletionPort      = modkernel32.NewProc("CreateIoCompletionPort")
 	procGetQueuedCompletionStatus   = modkernel32.NewProc("GetQueuedCompletionStatus")
@@ -427,11 +426,6 @@ func GetSystemTimeAsFileTime(time *Filetime) {
 	return
 }
 
-func sleep(msec uint32) {
-	Syscall(procSleep.Addr(), 1, uintptr(msec), 0, 0)
-	return
-}
-
 func GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) {
 	r0, _, e1 := Syscall(procGetTimeZoneInformation.Addr(), 1, uintptr(unsafe.Pointer(tzi)), 0, 0)
 	rc = uint32(r0)

src/pkg/syscall/zsyscall_windows_amd64.go

@@ -41,7 +41,6 @@ var (
 	procGetComputerNameW            = modkernel32.NewProc("GetComputerNameW")
 	procSetEndOfFile                = modkernel32.NewProc("SetEndOfFile")
 	procGetSystemTimeAsFileTime     = modkernel32.NewProc("GetSystemTimeAsFileTime")
-	procSleep                       = modkernel32.NewProc("Sleep")
 	procGetTimeZoneInformation      = modkernel32.NewProc("GetTimeZoneInformation")
 	procCreateIoCompletionPort      = modkernel32.NewProc("CreateIoCompletionPort")
 	procGetQueuedCompletionStatus   = modkernel32.NewProc("GetQueuedCompletionStatus")
@@ -427,11 +426,6 @@ func GetSystemTimeAsFileTime(time *Filetime) {
 	return
 }
 
-func sleep(msec uint32) {
-	Syscall(procSleep.Addr(), 1, uintptr(msec), 0, 0)
-	return
-}
-
 func GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) {
 	r0, _, e1 := Syscall(procGetTimeZoneInformation.Addr(), 1, uintptr(unsafe.Pointer(tzi)), 0, 0)
 	rc = uint32(r0)