github.com/peggyl/go@v0.0.0-20151008231540-ae315999c2d5/src/syscall/syscall_windows.go (about)

     1  // Copyright 2009 The Go Authors.  All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  // Windows system calls.
     6  
     7  package syscall
     8  
     9  import (
    10  	errorspkg "errors"
    11  	"sync"
    12  	"unicode/utf16"
    13  	"unsafe"
    14  )
    15  
    16  //go:generate go run mksyscall_windows.go -output zsyscall_windows.go syscall_windows.go security_windows.go
    17  
    18  type Handle uintptr
    19  
    20  const InvalidHandle = ^Handle(0)
    21  
    22  // StringToUTF16 returns the UTF-16 encoding of the UTF-8 string s,
    23  // with a terminating NUL added. If s contains a NUL byte this
    24  // function panics instead of returning an error.
    25  //
    26  // Deprecated: Use UTF16FromString instead.
    27  func StringToUTF16(s string) []uint16 {
    28  	a, err := UTF16FromString(s)
    29  	if err != nil {
    30  		panic("syscall: string with NUL passed to StringToUTF16")
    31  	}
    32  	return a
    33  }
    34  
    35  // UTF16FromString returns the UTF-16 encoding of the UTF-8 string
    36  // s, with a terminating NUL added. If s contains a NUL byte at any
    37  // location, it returns (nil, EINVAL).
    38  func UTF16FromString(s string) ([]uint16, error) {
    39  	for i := 0; i < len(s); i++ {
    40  		if s[i] == 0 {
    41  			return nil, EINVAL
    42  		}
    43  	}
    44  	return utf16.Encode([]rune(s + "\x00")), nil
    45  }
    46  
    47  // UTF16ToString returns the UTF-8 encoding of the UTF-16 sequence s,
    48  // with a terminating NUL removed.
    49  func UTF16ToString(s []uint16) string {
    50  	for i, v := range s {
    51  		if v == 0 {
    52  			s = s[0:i]
    53  			break
    54  		}
    55  	}
    56  	return string(utf16.Decode(s))
    57  }
    58  
    59  // StringToUTF16Ptr returns pointer to the UTF-16 encoding of
    60  // the UTF-8 string s, with a terminating NUL added. If s
    61  // If s contains a NUL byte this function panics instead of
    62  // returning an error.
    63  //
    64  // Deprecated: Use UTF16PtrFromString instead.
    65  func StringToUTF16Ptr(s string) *uint16 { return &StringToUTF16(s)[0] }
    66  
    67  // UTF16PtrFromString returns pointer to the UTF-16 encoding of
    68  // the UTF-8 string s, with a terminating NUL added. If s
    69  // contains a NUL byte at any location, it returns (nil, EINVAL).
    70  func UTF16PtrFromString(s string) (*uint16, error) {
    71  	a, err := UTF16FromString(s)
    72  	if err != nil {
    73  		return nil, err
    74  	}
    75  	return &a[0], nil
    76  }
    77  
    78  func Getpagesize() int { return 4096 }
    79  
    80  // Errno is the Windows error number.
    81  type Errno uintptr
    82  
    83  func langid(pri, sub uint16) uint32 { return uint32(sub)<<10 | uint32(pri) }
    84  
    85  // FormatMessage is deprecated (msgsrc should be uintptr, not uint32, but can
    86  // not be changed due to the Go 1 compatibility guarantee).
    87  //
    88  // Deprecated: Use FormatMessage from golang.org/x/sys/windows instead.
    89  func FormatMessage(flags uint32, msgsrc uint32, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) {
    90  	return formatMessage(flags, uintptr(msgsrc), msgid, langid, buf, args)
    91  }
    92  
    93  func (e Errno) Error() string {
    94  	// deal with special go errors
    95  	idx := int(e - APPLICATION_ERROR)
    96  	if 0 <= idx && idx < len(errors) {
    97  		return errors[idx]
    98  	}
    99  	// ask windows for the remaining errors
   100  	var flags uint32 = FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_ARGUMENT_ARRAY | FORMAT_MESSAGE_IGNORE_INSERTS
   101  	b := make([]uint16, 300)
   102  	n, err := formatMessage(flags, 0, uint32(e), langid(LANG_ENGLISH, SUBLANG_ENGLISH_US), b, nil)
   103  	if err != nil {
   104  		n, err = formatMessage(flags, 0, uint32(e), 0, b, nil)
   105  		if err != nil {
   106  			return "winapi error #" + itoa(int(e))
   107  		}
   108  	}
   109  	// trim terminating \r and \n
   110  	for ; n > 0 && (b[n-1] == '\n' || b[n-1] == '\r'); n-- {
   111  	}
   112  	return string(utf16.Decode(b[:n]))
   113  }
   114  
   115  func (e Errno) Temporary() bool {
   116  	return e == EINTR || e == EMFILE || e.Timeout()
   117  }
   118  
   119  func (e Errno) Timeout() bool {
   120  	return e == EAGAIN || e == EWOULDBLOCK || e == ETIMEDOUT
   121  }
   122  
   123  // Implemented in runtime/syscall_windows.go.
   124  func compileCallback(fn interface{}, cleanstack bool) uintptr
   125  
   126  // Converts a Go function to a function pointer conforming
   127  // to the stdcall calling convention. This is useful when
   128  // interoperating with Windows code requiring callbacks.
   129  func NewCallback(fn interface{}) uintptr {
   130  	return compileCallback(fn, true)
   131  }
   132  
   133  // Converts a Go function to a function pointer conforming
   134  // to the cdecl calling convention. This is useful when
   135  // interoperating with Windows code requiring callbacks.
   136  func NewCallbackCDecl(fn interface{}) uintptr {
   137  	return compileCallback(fn, false)
   138  }
   139  
   140  // windows api calls
   141  
   142  //sys	GetLastError() (lasterr error)
   143  //sys	LoadLibrary(libname string) (handle Handle, err error) = LoadLibraryW
   144  //sys	FreeLibrary(handle Handle) (err error)
   145  //sys	GetProcAddress(module Handle, procname string) (proc uintptr, err error)
   146  //sys	GetVersion() (ver uint32, err error)
   147  //sys	formatMessage(flags uint32, msgsrc uintptr, msgid uint32, langid uint32, buf []uint16, args *byte) (n uint32, err error) = FormatMessageW
   148  //sys	ExitProcess(exitcode uint32)
   149  //sys	CreateFile(name *uint16, access uint32, mode uint32, sa *SecurityAttributes, createmode uint32, attrs uint32, templatefile int32) (handle Handle, err error) [failretval==InvalidHandle] = CreateFileW
   150  //sys	ReadFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error)
   151  //sys	WriteFile(handle Handle, buf []byte, done *uint32, overlapped *Overlapped) (err error)
   152  //sys	SetFilePointer(handle Handle, lowoffset int32, highoffsetptr *int32, whence uint32) (newlowoffset uint32, err error) [failretval==0xffffffff]
   153  //sys	CloseHandle(handle Handle) (err error)
   154  //sys	GetStdHandle(stdhandle int) (handle Handle, err error) [failretval==InvalidHandle]
   155  //sys	findFirstFile1(name *uint16, data *win32finddata1) (handle Handle, err error) [failretval==InvalidHandle] = FindFirstFileW
   156  //sys	findNextFile1(handle Handle, data *win32finddata1) (err error) = FindNextFileW
   157  //sys	FindClose(handle Handle) (err error)
   158  //sys	GetFileInformationByHandle(handle Handle, data *ByHandleFileInformation) (err error)
   159  //sys	GetCurrentDirectory(buflen uint32, buf *uint16) (n uint32, err error) = GetCurrentDirectoryW
   160  //sys	SetCurrentDirectory(path *uint16) (err error) = SetCurrentDirectoryW
   161  //sys	CreateDirectory(path *uint16, sa *SecurityAttributes) (err error) = CreateDirectoryW
   162  //sys	RemoveDirectory(path *uint16) (err error) = RemoveDirectoryW
   163  //sys	DeleteFile(path *uint16) (err error) = DeleteFileW
   164  //sys	MoveFile(from *uint16, to *uint16) (err error) = MoveFileW
   165  //sys	GetComputerName(buf *uint16, n *uint32) (err error) = GetComputerNameW
   166  //sys	SetEndOfFile(handle Handle) (err error)
   167  //sys	GetSystemTimeAsFileTime(time *Filetime)
   168  //sys	GetTimeZoneInformation(tzi *Timezoneinformation) (rc uint32, err error) [failretval==0xffffffff]
   169  //sys	CreateIoCompletionPort(filehandle Handle, cphandle Handle, key uint32, threadcnt uint32) (handle Handle, err error)
   170  //sys	GetQueuedCompletionStatus(cphandle Handle, qty *uint32, key *uint32, overlapped **Overlapped, timeout uint32) (err error)
   171  //sys	PostQueuedCompletionStatus(cphandle Handle, qty uint32, key uint32, overlapped *Overlapped) (err error)
   172  //sys	CancelIo(s Handle) (err error)
   173  //sys	CancelIoEx(s Handle, o *Overlapped) (err error)
   174  //sys	CreateProcess(appName *uint16, commandLine *uint16, procSecurity *SecurityAttributes, threadSecurity *SecurityAttributes, inheritHandles bool, creationFlags uint32, env *uint16, currentDir *uint16, startupInfo *StartupInfo, outProcInfo *ProcessInformation) (err error) = CreateProcessW
   175  //sys	OpenProcess(da uint32, inheritHandle bool, pid uint32) (handle Handle, err error)
   176  //sys	TerminateProcess(handle Handle, exitcode uint32) (err error)
   177  //sys	GetExitCodeProcess(handle Handle, exitcode *uint32) (err error)
   178  //sys	GetStartupInfo(startupInfo *StartupInfo) (err error) = GetStartupInfoW
   179  //sys	GetCurrentProcess() (pseudoHandle Handle, err error)
   180  //sys	GetProcessTimes(handle Handle, creationTime *Filetime, exitTime *Filetime, kernelTime *Filetime, userTime *Filetime) (err error)
   181  //sys	DuplicateHandle(hSourceProcessHandle Handle, hSourceHandle Handle, hTargetProcessHandle Handle, lpTargetHandle *Handle, dwDesiredAccess uint32, bInheritHandle bool, dwOptions uint32) (err error)
   182  //sys	WaitForSingleObject(handle Handle, waitMilliseconds uint32) (event uint32, err error) [failretval==0xffffffff]
   183  //sys	GetTempPath(buflen uint32, buf *uint16) (n uint32, err error) = GetTempPathW
   184  //sys	CreatePipe(readhandle *Handle, writehandle *Handle, sa *SecurityAttributes, size uint32) (err error)
   185  //sys	GetFileType(filehandle Handle) (n uint32, err error)
   186  //sys	CryptAcquireContext(provhandle *Handle, container *uint16, provider *uint16, provtype uint32, flags uint32) (err error) = advapi32.CryptAcquireContextW
   187  //sys	CryptReleaseContext(provhandle Handle, flags uint32) (err error) = advapi32.CryptReleaseContext
   188  //sys	CryptGenRandom(provhandle Handle, buflen uint32, buf *byte) (err error) = advapi32.CryptGenRandom
   189  //sys	GetEnvironmentStrings() (envs *uint16, err error) [failretval==nil] = kernel32.GetEnvironmentStringsW
   190  //sys	FreeEnvironmentStrings(envs *uint16) (err error) = kernel32.FreeEnvironmentStringsW
   191  //sys	GetEnvironmentVariable(name *uint16, buffer *uint16, size uint32) (n uint32, err error) = kernel32.GetEnvironmentVariableW
   192  //sys	SetEnvironmentVariable(name *uint16, value *uint16) (err error) = kernel32.SetEnvironmentVariableW
   193  //sys	SetFileTime(handle Handle, ctime *Filetime, atime *Filetime, wtime *Filetime) (err error)
   194  //sys	GetFileAttributes(name *uint16) (attrs uint32, err error) [failretval==INVALID_FILE_ATTRIBUTES] = kernel32.GetFileAttributesW
   195  //sys	SetFileAttributes(name *uint16, attrs uint32) (err error) = kernel32.SetFileAttributesW
   196  //sys	GetFileAttributesEx(name *uint16, level uint32, info *byte) (err error) = kernel32.GetFileAttributesExW
   197  //sys	GetCommandLine() (cmd *uint16) = kernel32.GetCommandLineW
   198  //sys	CommandLineToArgv(cmd *uint16, argc *int32) (argv *[8192]*[8192]uint16, err error) [failretval==nil] = shell32.CommandLineToArgvW
   199  //sys	LocalFree(hmem Handle) (handle Handle, err error) [failretval!=0]
   200  //sys	SetHandleInformation(handle Handle, mask uint32, flags uint32) (err error)
   201  //sys	FlushFileBuffers(handle Handle) (err error)
   202  //sys	GetFullPathName(path *uint16, buflen uint32, buf *uint16, fname **uint16) (n uint32, err error) = kernel32.GetFullPathNameW
   203  //sys	GetLongPathName(path *uint16, buf *uint16, buflen uint32) (n uint32, err error) = kernel32.GetLongPathNameW
   204  //sys	GetShortPathName(longpath *uint16, shortpath *uint16, buflen uint32) (n uint32, err error) = kernel32.GetShortPathNameW
   205  //sys	CreateFileMapping(fhandle Handle, sa *SecurityAttributes, prot uint32, maxSizeHigh uint32, maxSizeLow uint32, name *uint16) (handle Handle, err error) = kernel32.CreateFileMappingW
   206  //sys	MapViewOfFile(handle Handle, access uint32, offsetHigh uint32, offsetLow uint32, length uintptr) (addr uintptr, err error)
   207  //sys	UnmapViewOfFile(addr uintptr) (err error)
   208  //sys	FlushViewOfFile(addr uintptr, length uintptr) (err error)
   209  //sys	VirtualLock(addr uintptr, length uintptr) (err error)
   210  //sys	VirtualUnlock(addr uintptr, length uintptr) (err error)
   211  //sys	TransmitFile(s Handle, handle Handle, bytesToWrite uint32, bytsPerSend uint32, overlapped *Overlapped, transmitFileBuf *TransmitFileBuffers, flags uint32) (err error) = mswsock.TransmitFile
   212  //sys	ReadDirectoryChanges(handle Handle, buf *byte, buflen uint32, watchSubTree bool, mask uint32, retlen *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) = kernel32.ReadDirectoryChangesW
   213  //sys	CertOpenSystemStore(hprov Handle, name *uint16) (store Handle, err error) = crypt32.CertOpenSystemStoreW
   214  //sys   CertOpenStore(storeProvider uintptr, msgAndCertEncodingType uint32, cryptProv uintptr, flags uint32, para uintptr) (handle Handle, err error) [failretval==InvalidHandle] = crypt32.CertOpenStore
   215  //sys	CertEnumCertificatesInStore(store Handle, prevContext *CertContext) (context *CertContext, err error) [failretval==nil] = crypt32.CertEnumCertificatesInStore
   216  //sys   CertAddCertificateContextToStore(store Handle, certContext *CertContext, addDisposition uint32, storeContext **CertContext) (err error) = crypt32.CertAddCertificateContextToStore
   217  //sys	CertCloseStore(store Handle, flags uint32) (err error) = crypt32.CertCloseStore
   218  //sys   CertGetCertificateChain(engine Handle, leaf *CertContext, time *Filetime, additionalStore Handle, para *CertChainPara, flags uint32, reserved uintptr, chainCtx **CertChainContext) (err error) = crypt32.CertGetCertificateChain
   219  //sys   CertFreeCertificateChain(ctx *CertChainContext) = crypt32.CertFreeCertificateChain
   220  //sys   CertCreateCertificateContext(certEncodingType uint32, certEncoded *byte, encodedLen uint32) (context *CertContext, err error) [failretval==nil] = crypt32.CertCreateCertificateContext
   221  //sys   CertFreeCertificateContext(ctx *CertContext) (err error) = crypt32.CertFreeCertificateContext
   222  //sys   CertVerifyCertificateChainPolicy(policyOID uintptr, chain *CertChainContext, para *CertChainPolicyPara, status *CertChainPolicyStatus) (err error) = crypt32.CertVerifyCertificateChainPolicy
   223  //sys	RegOpenKeyEx(key Handle, subkey *uint16, options uint32, desiredAccess uint32, result *Handle) (regerrno error) = advapi32.RegOpenKeyExW
   224  //sys	RegCloseKey(key Handle) (regerrno error) = advapi32.RegCloseKey
   225  //sys	RegQueryInfoKey(key Handle, class *uint16, classLen *uint32, reserved *uint32, subkeysLen *uint32, maxSubkeyLen *uint32, maxClassLen *uint32, valuesLen *uint32, maxValueNameLen *uint32, maxValueLen *uint32, saLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegQueryInfoKeyW
   226  //sys	RegEnumKeyEx(key Handle, index uint32, name *uint16, nameLen *uint32, reserved *uint32, class *uint16, classLen *uint32, lastWriteTime *Filetime) (regerrno error) = advapi32.RegEnumKeyExW
   227  //sys	RegQueryValueEx(key Handle, name *uint16, reserved *uint32, valtype *uint32, buf *byte, buflen *uint32) (regerrno error) = advapi32.RegQueryValueExW
   228  //sys	getCurrentProcessId() (pid uint32) = kernel32.GetCurrentProcessId
   229  //sys	GetConsoleMode(console Handle, mode *uint32) (err error) = kernel32.GetConsoleMode
   230  //sys	WriteConsole(console Handle, buf *uint16, towrite uint32, written *uint32, reserved *byte) (err error) = kernel32.WriteConsoleW
   231  //sys	ReadConsole(console Handle, buf *uint16, toread uint32, read *uint32, inputControl *byte) (err error) = kernel32.ReadConsoleW
   232  //sys	CreateToolhelp32Snapshot(flags uint32, processId uint32) (handle Handle, err error) [failretval==InvalidHandle] = kernel32.CreateToolhelp32Snapshot
   233  //sys	Process32First(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32FirstW
   234  //sys	Process32Next(snapshot Handle, procEntry *ProcessEntry32) (err error) = kernel32.Process32NextW
   235  //sys	DeviceIoControl(handle Handle, ioControlCode uint32, inBuffer *byte, inBufferSize uint32, outBuffer *byte, outBufferSize uint32, bytesReturned *uint32, overlapped *Overlapped) (err error)
   236  // This function returns 1 byte BOOLEAN rather than the 4 byte BOOL.
   237  //sys	CreateSymbolicLink(symlinkfilename *uint16, targetfilename *uint16, flags uint32) (err error) [failretval&0xff==0] = CreateSymbolicLinkW
   238  //sys	CreateHardLink(filename *uint16, existingfilename *uint16, reserved uintptr) (err error) [failretval&0xff==0] = CreateHardLinkW
   239  
   240  // syscall interface implementation for other packages
   241  
   242  func Exit(code int) { ExitProcess(uint32(code)) }
   243  
   244  func makeInheritSa() *SecurityAttributes {
   245  	var sa SecurityAttributes
   246  	sa.Length = uint32(unsafe.Sizeof(sa))
   247  	sa.InheritHandle = 1
   248  	return &sa
   249  }
   250  
   251  func Open(path string, mode int, perm uint32) (fd Handle, err error) {
   252  	if len(path) == 0 {
   253  		return InvalidHandle, ERROR_FILE_NOT_FOUND
   254  	}
   255  	pathp, err := UTF16PtrFromString(path)
   256  	if err != nil {
   257  		return InvalidHandle, err
   258  	}
   259  	var access uint32
   260  	switch mode & (O_RDONLY | O_WRONLY | O_RDWR) {
   261  	case O_RDONLY:
   262  		access = GENERIC_READ
   263  	case O_WRONLY:
   264  		access = GENERIC_WRITE
   265  	case O_RDWR:
   266  		access = GENERIC_READ | GENERIC_WRITE
   267  	}
   268  	if mode&O_CREAT != 0 {
   269  		access |= GENERIC_WRITE
   270  	}
   271  	if mode&O_APPEND != 0 {
   272  		access &^= GENERIC_WRITE
   273  		access |= FILE_APPEND_DATA
   274  	}
   275  	sharemode := uint32(FILE_SHARE_READ | FILE_SHARE_WRITE)
   276  	var sa *SecurityAttributes
   277  	if mode&O_CLOEXEC == 0 {
   278  		sa = makeInheritSa()
   279  	}
   280  	var createmode uint32
   281  	switch {
   282  	case mode&(O_CREAT|O_EXCL) == (O_CREAT | O_EXCL):
   283  		createmode = CREATE_NEW
   284  	case mode&(O_CREAT|O_TRUNC) == (O_CREAT | O_TRUNC):
   285  		createmode = CREATE_ALWAYS
   286  	case mode&O_CREAT == O_CREAT:
   287  		createmode = OPEN_ALWAYS
   288  	case mode&O_TRUNC == O_TRUNC:
   289  		createmode = TRUNCATE_EXISTING
   290  	default:
   291  		createmode = OPEN_EXISTING
   292  	}
   293  	h, e := CreateFile(pathp, access, sharemode, sa, createmode, FILE_ATTRIBUTE_NORMAL, 0)
   294  	return h, e
   295  }
   296  
   297  func Read(fd Handle, p []byte) (n int, err error) {
   298  	var done uint32
   299  	e := ReadFile(fd, p, &done, nil)
   300  	if e != nil {
   301  		if e == ERROR_BROKEN_PIPE {
   302  			// NOTE(brainman): work around ERROR_BROKEN_PIPE is returned on reading EOF from stdin
   303  			return 0, nil
   304  		}
   305  		return 0, e
   306  	}
   307  	if raceenabled {
   308  		if done > 0 {
   309  			raceWriteRange(unsafe.Pointer(&p[0]), int(done))
   310  		}
   311  		raceAcquire(unsafe.Pointer(&ioSync))
   312  	}
   313  	return int(done), nil
   314  }
   315  
   316  func Write(fd Handle, p []byte) (n int, err error) {
   317  	if raceenabled {
   318  		raceReleaseMerge(unsafe.Pointer(&ioSync))
   319  	}
   320  	var done uint32
   321  	e := WriteFile(fd, p, &done, nil)
   322  	if e != nil {
   323  		return 0, e
   324  	}
   325  	if raceenabled && done > 0 {
   326  		raceReadRange(unsafe.Pointer(&p[0]), int(done))
   327  	}
   328  	return int(done), nil
   329  }
   330  
   331  var ioSync int64
   332  
   333  func Seek(fd Handle, offset int64, whence int) (newoffset int64, err error) {
   334  	var w uint32
   335  	switch whence {
   336  	case 0:
   337  		w = FILE_BEGIN
   338  	case 1:
   339  		w = FILE_CURRENT
   340  	case 2:
   341  		w = FILE_END
   342  	}
   343  	hi := int32(offset >> 32)
   344  	lo := int32(offset)
   345  	// use GetFileType to check pipe, pipe can't do seek
   346  	ft, _ := GetFileType(fd)
   347  	if ft == FILE_TYPE_PIPE {
   348  		return 0, EPIPE
   349  	}
   350  	rlo, e := SetFilePointer(fd, lo, &hi, w)
   351  	if e != nil {
   352  		return 0, e
   353  	}
   354  	return int64(hi)<<32 + int64(rlo), nil
   355  }
   356  
   357  func Close(fd Handle) (err error) {
   358  	return CloseHandle(fd)
   359  }
   360  
   361  var (
   362  	Stdin  = getStdHandle(STD_INPUT_HANDLE)
   363  	Stdout = getStdHandle(STD_OUTPUT_HANDLE)
   364  	Stderr = getStdHandle(STD_ERROR_HANDLE)
   365  )
   366  
   367  func getStdHandle(h int) (fd Handle) {
   368  	r, _ := GetStdHandle(h)
   369  	CloseOnExec(r)
   370  	return r
   371  }
   372  
   373  const ImplementsGetwd = true
   374  
   375  func Getwd() (wd string, err error) {
   376  	b := make([]uint16, 300)
   377  	n, e := GetCurrentDirectory(uint32(len(b)), &b[0])
   378  	if e != nil {
   379  		return "", e
   380  	}
   381  	return string(utf16.Decode(b[0:n])), nil
   382  }
   383  
   384  func Chdir(path string) (err error) {
   385  	pathp, err := UTF16PtrFromString(path)
   386  	if err != nil {
   387  		return err
   388  	}
   389  	return SetCurrentDirectory(pathp)
   390  }
   391  
   392  func Mkdir(path string, mode uint32) (err error) {
   393  	pathp, err := UTF16PtrFromString(path)
   394  	if err != nil {
   395  		return err
   396  	}
   397  	return CreateDirectory(pathp, nil)
   398  }
   399  
   400  func Rmdir(path string) (err error) {
   401  	pathp, err := UTF16PtrFromString(path)
   402  	if err != nil {
   403  		return err
   404  	}
   405  	return RemoveDirectory(pathp)
   406  }
   407  
   408  func Unlink(path string) (err error) {
   409  	pathp, err := UTF16PtrFromString(path)
   410  	if err != nil {
   411  		return err
   412  	}
   413  	return DeleteFile(pathp)
   414  }
   415  
   416  func Rename(oldpath, newpath string) (err error) {
   417  	from, err := UTF16PtrFromString(oldpath)
   418  	if err != nil {
   419  		return err
   420  	}
   421  	to, err := UTF16PtrFromString(newpath)
   422  	if err != nil {
   423  		return err
   424  	}
   425  	return MoveFile(from, to)
   426  }
   427  
   428  func ComputerName() (name string, err error) {
   429  	var n uint32 = MAX_COMPUTERNAME_LENGTH + 1
   430  	b := make([]uint16, n)
   431  	e := GetComputerName(&b[0], &n)
   432  	if e != nil {
   433  		return "", e
   434  	}
   435  	return string(utf16.Decode(b[0:n])), nil
   436  }
   437  
   438  func Ftruncate(fd Handle, length int64) (err error) {
   439  	curoffset, e := Seek(fd, 0, 1)
   440  	if e != nil {
   441  		return e
   442  	}
   443  	defer Seek(fd, curoffset, 0)
   444  	_, e = Seek(fd, length, 0)
   445  	if e != nil {
   446  		return e
   447  	}
   448  	e = SetEndOfFile(fd)
   449  	if e != nil {
   450  		return e
   451  	}
   452  	return nil
   453  }
   454  
   455  func Gettimeofday(tv *Timeval) (err error) {
   456  	var ft Filetime
   457  	GetSystemTimeAsFileTime(&ft)
   458  	*tv = NsecToTimeval(ft.Nanoseconds())
   459  	return nil
   460  }
   461  
   462  func Pipe(p []Handle) (err error) {
   463  	if len(p) != 2 {
   464  		return EINVAL
   465  	}
   466  	var r, w Handle
   467  	e := CreatePipe(&r, &w, makeInheritSa(), 0)
   468  	if e != nil {
   469  		return e
   470  	}
   471  	p[0] = r
   472  	p[1] = w
   473  	return nil
   474  }
   475  
   476  func Utimes(path string, tv []Timeval) (err error) {
   477  	if len(tv) != 2 {
   478  		return EINVAL
   479  	}
   480  	pathp, e := UTF16PtrFromString(path)
   481  	if e != nil {
   482  		return e
   483  	}
   484  	h, e := CreateFile(pathp,
   485  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   486  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   487  	if e != nil {
   488  		return e
   489  	}
   490  	defer Close(h)
   491  	a := NsecToFiletime(tv[0].Nanoseconds())
   492  	w := NsecToFiletime(tv[1].Nanoseconds())
   493  	return SetFileTime(h, nil, &a, &w)
   494  }
   495  
   496  func UtimesNano(path string, ts []Timespec) (err error) {
   497  	if len(ts) != 2 {
   498  		return EINVAL
   499  	}
   500  	pathp, e := UTF16PtrFromString(path)
   501  	if e != nil {
   502  		return e
   503  	}
   504  	h, e := CreateFile(pathp,
   505  		FILE_WRITE_ATTRIBUTES, FILE_SHARE_WRITE, nil,
   506  		OPEN_EXISTING, FILE_FLAG_BACKUP_SEMANTICS, 0)
   507  	if e != nil {
   508  		return e
   509  	}
   510  	defer Close(h)
   511  	a := NsecToFiletime(TimespecToNsec(ts[0]))
   512  	w := NsecToFiletime(TimespecToNsec(ts[1]))
   513  	return SetFileTime(h, nil, &a, &w)
   514  }
   515  
   516  func Fsync(fd Handle) (err error) {
   517  	return FlushFileBuffers(fd)
   518  }
   519  
   520  func Chmod(path string, mode uint32) (err error) {
   521  	if mode == 0 {
   522  		return EINVAL
   523  	}
   524  	p, e := UTF16PtrFromString(path)
   525  	if e != nil {
   526  		return e
   527  	}
   528  	attrs, e := GetFileAttributes(p)
   529  	if e != nil {
   530  		return e
   531  	}
   532  	if mode&S_IWRITE != 0 {
   533  		attrs &^= FILE_ATTRIBUTE_READONLY
   534  	} else {
   535  		attrs |= FILE_ATTRIBUTE_READONLY
   536  	}
   537  	return SetFileAttributes(p, attrs)
   538  }
   539  
   540  func LoadCancelIoEx() error {
   541  	return procCancelIoEx.Find()
   542  }
   543  
   544  func LoadSetFileCompletionNotificationModes() error {
   545  	return procSetFileCompletionNotificationModes.Find()
   546  }
   547  
   548  // net api calls
   549  
   550  const socket_error = uintptr(^uint32(0))
   551  
   552  //sys	WSAStartup(verreq uint32, data *WSAData) (sockerr error) = ws2_32.WSAStartup
   553  //sys	WSACleanup() (err error) [failretval==socket_error] = ws2_32.WSACleanup
   554  //sys	WSAIoctl(s Handle, iocc uint32, inbuf *byte, cbif uint32, outbuf *byte, cbob uint32, cbbr *uint32, overlapped *Overlapped, completionRoutine uintptr) (err error) [failretval==socket_error] = ws2_32.WSAIoctl
   555  //sys	socket(af int32, typ int32, protocol int32) (handle Handle, err error) [failretval==InvalidHandle] = ws2_32.socket
   556  //sys	Setsockopt(s Handle, level int32, optname int32, optval *byte, optlen int32) (err error) [failretval==socket_error] = ws2_32.setsockopt
   557  //sys	Getsockopt(s Handle, level int32, optname int32, optval *byte, optlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockopt
   558  //sys	bind(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.bind
   559  //sys	connect(s Handle, name unsafe.Pointer, namelen int32) (err error) [failretval==socket_error] = ws2_32.connect
   560  //sys	getsockname(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getsockname
   561  //sys	getpeername(s Handle, rsa *RawSockaddrAny, addrlen *int32) (err error) [failretval==socket_error] = ws2_32.getpeername
   562  //sys	listen(s Handle, backlog int32) (err error) [failretval==socket_error] = ws2_32.listen
   563  //sys	shutdown(s Handle, how int32) (err error) [failretval==socket_error] = ws2_32.shutdown
   564  //sys	Closesocket(s Handle) (err error) [failretval==socket_error] = ws2_32.closesocket
   565  //sys	AcceptEx(ls Handle, as Handle, buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, recvd *uint32, overlapped *Overlapped) (err error) = mswsock.AcceptEx
   566  //sys	GetAcceptExSockaddrs(buf *byte, rxdatalen uint32, laddrlen uint32, raddrlen uint32, lrsa **RawSockaddrAny, lrsalen *int32, rrsa **RawSockaddrAny, rrsalen *int32) = mswsock.GetAcceptExSockaddrs
   567  //sys	WSARecv(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecv
   568  //sys	WSASend(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASend
   569  //sys	WSARecvFrom(s Handle, bufs *WSABuf, bufcnt uint32, recvd *uint32, flags *uint32,  from *RawSockaddrAny, fromlen *int32, overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSARecvFrom
   570  //sys	WSASendTo(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to *RawSockaddrAny, tolen int32,  overlapped *Overlapped, croutine *byte) (err error) [failretval==socket_error] = ws2_32.WSASendTo
   571  //sys	GetHostByName(name string) (h *Hostent, err error) [failretval==nil] = ws2_32.gethostbyname
   572  //sys	GetServByName(name string, proto string) (s *Servent, err error) [failretval==nil] = ws2_32.getservbyname
   573  //sys	Ntohs(netshort uint16) (u uint16) = ws2_32.ntohs
   574  //sys	GetProtoByName(name string) (p *Protoent, err error) [failretval==nil] = ws2_32.getprotobyname
   575  //sys	DnsQuery(name string, qtype uint16, options uint32, extra *byte, qrs **DNSRecord, pr *byte) (status error) = dnsapi.DnsQuery_W
   576  //sys	DnsRecordListFree(rl *DNSRecord, freetype uint32) = dnsapi.DnsRecordListFree
   577  //sys	DnsNameCompare(name1 *uint16, name2 *uint16) (same bool) = dnsapi.DnsNameCompare_W
   578  //sys	GetAddrInfoW(nodename *uint16, servicename *uint16, hints *AddrinfoW, result **AddrinfoW) (sockerr error) = ws2_32.GetAddrInfoW
   579  //sys	FreeAddrInfoW(addrinfo *AddrinfoW) = ws2_32.FreeAddrInfoW
   580  //sys	GetIfEntry(pIfRow *MibIfRow) (errcode error) = iphlpapi.GetIfEntry
   581  //sys	GetAdaptersInfo(ai *IpAdapterInfo, ol *uint32) (errcode error) = iphlpapi.GetAdaptersInfo
   582  //sys	SetFileCompletionNotificationModes(handle Handle, flags uint8) (err error) = kernel32.SetFileCompletionNotificationModes
   583  //sys	WSAEnumProtocols(protocols *int32, protocolBuffer *WSAProtocolInfo, bufferLength *uint32) (n int32, err error) [failretval==-1] = ws2_32.WSAEnumProtocolsW
   584  
   585  // For testing: clients can set this flag to force
   586  // creation of IPv6 sockets to return EAFNOSUPPORT.
   587  var SocketDisableIPv6 bool
   588  
   589  type RawSockaddrInet4 struct {
   590  	Family uint16
   591  	Port   uint16
   592  	Addr   [4]byte /* in_addr */
   593  	Zero   [8]uint8
   594  }
   595  
   596  type RawSockaddrInet6 struct {
   597  	Family   uint16
   598  	Port     uint16
   599  	Flowinfo uint32
   600  	Addr     [16]byte /* in6_addr */
   601  	Scope_id uint32
   602  }
   603  
   604  type RawSockaddr struct {
   605  	Family uint16
   606  	Data   [14]int8
   607  }
   608  
   609  type RawSockaddrAny struct {
   610  	Addr RawSockaddr
   611  	Pad  [96]int8
   612  }
   613  
   614  type Sockaddr interface {
   615  	sockaddr() (ptr unsafe.Pointer, len int32, err error) // lowercase; only we can define Sockaddrs
   616  }
   617  
   618  type SockaddrInet4 struct {
   619  	Port int
   620  	Addr [4]byte
   621  	raw  RawSockaddrInet4
   622  }
   623  
   624  func (sa *SockaddrInet4) sockaddr() (unsafe.Pointer, int32, error) {
   625  	if sa.Port < 0 || sa.Port > 0xFFFF {
   626  		return nil, 0, EINVAL
   627  	}
   628  	sa.raw.Family = AF_INET
   629  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   630  	p[0] = byte(sa.Port >> 8)
   631  	p[1] = byte(sa.Port)
   632  	for i := 0; i < len(sa.Addr); i++ {
   633  		sa.raw.Addr[i] = sa.Addr[i]
   634  	}
   635  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   636  }
   637  
   638  type SockaddrInet6 struct {
   639  	Port   int
   640  	ZoneId uint32
   641  	Addr   [16]byte
   642  	raw    RawSockaddrInet6
   643  }
   644  
   645  func (sa *SockaddrInet6) sockaddr() (unsafe.Pointer, int32, error) {
   646  	if sa.Port < 0 || sa.Port > 0xFFFF {
   647  		return nil, 0, EINVAL
   648  	}
   649  	sa.raw.Family = AF_INET6
   650  	p := (*[2]byte)(unsafe.Pointer(&sa.raw.Port))
   651  	p[0] = byte(sa.Port >> 8)
   652  	p[1] = byte(sa.Port)
   653  	sa.raw.Scope_id = sa.ZoneId
   654  	for i := 0; i < len(sa.Addr); i++ {
   655  		sa.raw.Addr[i] = sa.Addr[i]
   656  	}
   657  	return unsafe.Pointer(&sa.raw), int32(unsafe.Sizeof(sa.raw)), nil
   658  }
   659  
   660  type SockaddrUnix struct {
   661  	Name string
   662  }
   663  
   664  func (sa *SockaddrUnix) sockaddr() (unsafe.Pointer, int32, error) {
   665  	// TODO(brainman): implement SockaddrUnix.sockaddr()
   666  	return nil, 0, EWINDOWS
   667  }
   668  
   669  func (rsa *RawSockaddrAny) Sockaddr() (Sockaddr, error) {
   670  	switch rsa.Addr.Family {
   671  	case AF_UNIX:
   672  		return nil, EWINDOWS
   673  
   674  	case AF_INET:
   675  		pp := (*RawSockaddrInet4)(unsafe.Pointer(rsa))
   676  		sa := new(SockaddrInet4)
   677  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   678  		sa.Port = int(p[0])<<8 + int(p[1])
   679  		for i := 0; i < len(sa.Addr); i++ {
   680  			sa.Addr[i] = pp.Addr[i]
   681  		}
   682  		return sa, nil
   683  
   684  	case AF_INET6:
   685  		pp := (*RawSockaddrInet6)(unsafe.Pointer(rsa))
   686  		sa := new(SockaddrInet6)
   687  		p := (*[2]byte)(unsafe.Pointer(&pp.Port))
   688  		sa.Port = int(p[0])<<8 + int(p[1])
   689  		sa.ZoneId = pp.Scope_id
   690  		for i := 0; i < len(sa.Addr); i++ {
   691  			sa.Addr[i] = pp.Addr[i]
   692  		}
   693  		return sa, nil
   694  	}
   695  	return nil, EAFNOSUPPORT
   696  }
   697  
   698  func Socket(domain, typ, proto int) (fd Handle, err error) {
   699  	if domain == AF_INET6 && SocketDisableIPv6 {
   700  		return InvalidHandle, EAFNOSUPPORT
   701  	}
   702  	return socket(int32(domain), int32(typ), int32(proto))
   703  }
   704  
   705  func SetsockoptInt(fd Handle, level, opt int, value int) (err error) {
   706  	v := int32(value)
   707  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&v)), int32(unsafe.Sizeof(v)))
   708  }
   709  
   710  func Bind(fd Handle, sa Sockaddr) (err error) {
   711  	ptr, n, err := sa.sockaddr()
   712  	if err != nil {
   713  		return err
   714  	}
   715  	return bind(fd, ptr, n)
   716  }
   717  
   718  func Connect(fd Handle, sa Sockaddr) (err error) {
   719  	ptr, n, err := sa.sockaddr()
   720  	if err != nil {
   721  		return err
   722  	}
   723  	return connect(fd, ptr, n)
   724  }
   725  
   726  func Getsockname(fd Handle) (sa Sockaddr, err error) {
   727  	var rsa RawSockaddrAny
   728  	l := int32(unsafe.Sizeof(rsa))
   729  	if err = getsockname(fd, &rsa, &l); err != nil {
   730  		return
   731  	}
   732  	return rsa.Sockaddr()
   733  }
   734  
   735  func Getpeername(fd Handle) (sa Sockaddr, err error) {
   736  	var rsa RawSockaddrAny
   737  	l := int32(unsafe.Sizeof(rsa))
   738  	if err = getpeername(fd, &rsa, &l); err != nil {
   739  		return
   740  	}
   741  	return rsa.Sockaddr()
   742  }
   743  
   744  func Listen(s Handle, n int) (err error) {
   745  	return listen(s, int32(n))
   746  }
   747  
   748  func Shutdown(fd Handle, how int) (err error) {
   749  	return shutdown(fd, int32(how))
   750  }
   751  
   752  func WSASendto(s Handle, bufs *WSABuf, bufcnt uint32, sent *uint32, flags uint32, to Sockaddr, overlapped *Overlapped, croutine *byte) (err error) {
   753  	rsa, l, err := to.sockaddr()
   754  	if err != nil {
   755  		return err
   756  	}
   757  	return WSASendTo(s, bufs, bufcnt, sent, flags, (*RawSockaddrAny)(unsafe.Pointer(rsa)), l, overlapped, croutine)
   758  }
   759  
   760  func LoadGetAddrInfo() error {
   761  	return procGetAddrInfoW.Find()
   762  }
   763  
   764  var connectExFunc struct {
   765  	once sync.Once
   766  	addr uintptr
   767  	err  error
   768  }
   769  
   770  func LoadConnectEx() error {
   771  	connectExFunc.once.Do(func() {
   772  		var s Handle
   773  		s, connectExFunc.err = Socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)
   774  		if connectExFunc.err != nil {
   775  			return
   776  		}
   777  		defer CloseHandle(s)
   778  		var n uint32
   779  		connectExFunc.err = WSAIoctl(s,
   780  			SIO_GET_EXTENSION_FUNCTION_POINTER,
   781  			(*byte)(unsafe.Pointer(&WSAID_CONNECTEX)),
   782  			uint32(unsafe.Sizeof(WSAID_CONNECTEX)),
   783  			(*byte)(unsafe.Pointer(&connectExFunc.addr)),
   784  			uint32(unsafe.Sizeof(connectExFunc.addr)),
   785  			&n, nil, 0)
   786  	})
   787  	return connectExFunc.err
   788  }
   789  
   790  func connectEx(s Handle, name unsafe.Pointer, namelen int32, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) (err error) {
   791  	r1, _, e1 := Syscall9(connectExFunc.addr, 7, uintptr(s), uintptr(name), uintptr(namelen), uintptr(unsafe.Pointer(sendBuf)), uintptr(sendDataLen), uintptr(unsafe.Pointer(bytesSent)), uintptr(unsafe.Pointer(overlapped)), 0, 0)
   792  	if r1 == 0 {
   793  		if e1 != 0 {
   794  			err = error(e1)
   795  		} else {
   796  			err = EINVAL
   797  		}
   798  	}
   799  	return
   800  }
   801  
   802  func ConnectEx(fd Handle, sa Sockaddr, sendBuf *byte, sendDataLen uint32, bytesSent *uint32, overlapped *Overlapped) error {
   803  	err := LoadConnectEx()
   804  	if err != nil {
   805  		return errorspkg.New("failed to find ConnectEx: " + err.Error())
   806  	}
   807  	ptr, n, err := sa.sockaddr()
   808  	if err != nil {
   809  		return err
   810  	}
   811  	return connectEx(fd, ptr, n, sendBuf, sendDataLen, bytesSent, overlapped)
   812  }
   813  
   814  // Invented structures to support what package os expects.
   815  type Rusage struct {
   816  	CreationTime Filetime
   817  	ExitTime     Filetime
   818  	KernelTime   Filetime
   819  	UserTime     Filetime
   820  }
   821  
   822  type WaitStatus struct {
   823  	ExitCode uint32
   824  }
   825  
   826  func (w WaitStatus) Exited() bool { return true }
   827  
   828  func (w WaitStatus) ExitStatus() int { return int(w.ExitCode) }
   829  
   830  func (w WaitStatus) Signal() Signal { return -1 }
   831  
   832  func (w WaitStatus) CoreDump() bool { return false }
   833  
   834  func (w WaitStatus) Stopped() bool { return false }
   835  
   836  func (w WaitStatus) Continued() bool { return false }
   837  
   838  func (w WaitStatus) StopSignal() Signal { return -1 }
   839  
   840  func (w WaitStatus) Signaled() bool { return false }
   841  
   842  func (w WaitStatus) TrapCause() int { return -1 }
   843  
   844  // Timespec is an invented structure on Windows, but here for
   845  // consistency with the syscall package for other operating systems.
   846  type Timespec struct {
   847  	Sec  int64
   848  	Nsec int64
   849  }
   850  
   851  func TimespecToNsec(ts Timespec) int64 { return int64(ts.Sec)*1e9 + int64(ts.Nsec) }
   852  
   853  func NsecToTimespec(nsec int64) (ts Timespec) {
   854  	ts.Sec = nsec / 1e9
   855  	ts.Nsec = nsec % 1e9
   856  	return
   857  }
   858  
   859  // TODO(brainman): fix all needed for net
   860  
   861  func Accept(fd Handle) (nfd Handle, sa Sockaddr, err error) { return 0, nil, EWINDOWS }
   862  func Recvfrom(fd Handle, p []byte, flags int) (n int, from Sockaddr, err error) {
   863  	return 0, nil, EWINDOWS
   864  }
   865  func Sendto(fd Handle, p []byte, flags int, to Sockaddr) (err error)       { return EWINDOWS }
   866  func SetsockoptTimeval(fd Handle, level, opt int, tv *Timeval) (err error) { return EWINDOWS }
   867  
   868  // The Linger struct is wrong but we only noticed after Go 1.
   869  // sysLinger is the real system call structure.
   870  
   871  // BUG(brainman): The definition of Linger is not appropriate for direct use
   872  // with Setsockopt and Getsockopt.
   873  // Use SetsockoptLinger instead.
   874  
   875  type Linger struct {
   876  	Onoff  int32
   877  	Linger int32
   878  }
   879  
   880  type sysLinger struct {
   881  	Onoff  uint16
   882  	Linger uint16
   883  }
   884  
   885  type IPMreq struct {
   886  	Multiaddr [4]byte /* in_addr */
   887  	Interface [4]byte /* in_addr */
   888  }
   889  
   890  type IPv6Mreq struct {
   891  	Multiaddr [16]byte /* in6_addr */
   892  	Interface uint32
   893  }
   894  
   895  func GetsockoptInt(fd Handle, level, opt int) (int, error) { return -1, EWINDOWS }
   896  
   897  func SetsockoptLinger(fd Handle, level, opt int, l *Linger) (err error) {
   898  	sys := sysLinger{Onoff: uint16(l.Onoff), Linger: uint16(l.Linger)}
   899  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&sys)), int32(unsafe.Sizeof(sys)))
   900  }
   901  
   902  func SetsockoptInet4Addr(fd Handle, level, opt int, value [4]byte) (err error) {
   903  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(&value[0])), 4)
   904  }
   905  func SetsockoptIPMreq(fd Handle, level, opt int, mreq *IPMreq) (err error) {
   906  	return Setsockopt(fd, int32(level), int32(opt), (*byte)(unsafe.Pointer(mreq)), int32(unsafe.Sizeof(*mreq)))
   907  }
   908  func SetsockoptIPv6Mreq(fd Handle, level, opt int, mreq *IPv6Mreq) (err error) { return EWINDOWS }
   909  
   910  func Getpid() (pid int) { return int(getCurrentProcessId()) }
   911  
   912  func FindFirstFile(name *uint16, data *Win32finddata) (handle Handle, err error) {
   913  	// NOTE(rsc): The Win32finddata struct is wrong for the system call:
   914  	// the two paths are each one uint16 short. Use the correct struct,
   915  	// a win32finddata1, and then copy the results out.
   916  	// There is no loss of expressivity here, because the final
   917  	// uint16, if it is used, is supposed to be a NUL, and Go doesn't need that.
   918  	// For Go 1.1, we might avoid the allocation of win32finddata1 here
   919  	// by adding a final Bug [2]uint16 field to the struct and then
   920  	// adjusting the fields in the result directly.
   921  	var data1 win32finddata1
   922  	handle, err = findFirstFile1(name, &data1)
   923  	if err == nil {
   924  		copyFindData(data, &data1)
   925  	}
   926  	return
   927  }
   928  
   929  func FindNextFile(handle Handle, data *Win32finddata) (err error) {
   930  	var data1 win32finddata1
   931  	err = findNextFile1(handle, &data1)
   932  	if err == nil {
   933  		copyFindData(data, &data1)
   934  	}
   935  	return
   936  }
   937  
   938  func getProcessEntry(pid int) (*ProcessEntry32, error) {
   939  	snapshot, err := CreateToolhelp32Snapshot(TH32CS_SNAPPROCESS, 0)
   940  	if err != nil {
   941  		return nil, err
   942  	}
   943  	defer CloseHandle(snapshot)
   944  	var procEntry ProcessEntry32
   945  	procEntry.Size = uint32(unsafe.Sizeof(procEntry))
   946  	if err = Process32First(snapshot, &procEntry); err != nil {
   947  		return nil, err
   948  	}
   949  	for {
   950  		if procEntry.ProcessID == uint32(pid) {
   951  			return &procEntry, nil
   952  		}
   953  		err = Process32Next(snapshot, &procEntry)
   954  		if err != nil {
   955  			return nil, err
   956  		}
   957  	}
   958  }
   959  
   960  func Getppid() (ppid int) {
   961  	pe, err := getProcessEntry(Getpid())
   962  	if err != nil {
   963  		return -1
   964  	}
   965  	return int(pe.ParentProcessID)
   966  }
   967  
   968  // TODO(brainman): fix all needed for os
   969  func Fchdir(fd Handle) (err error)             { return EWINDOWS }
   970  func Link(oldpath, newpath string) (err error) { return EWINDOWS }
   971  func Symlink(path, link string) (err error)    { return EWINDOWS }
   972  
   973  func Fchmod(fd Handle, mode uint32) (err error)        { return EWINDOWS }
   974  func Chown(path string, uid int, gid int) (err error)  { return EWINDOWS }
   975  func Lchown(path string, uid int, gid int) (err error) { return EWINDOWS }
   976  func Fchown(fd Handle, uid int, gid int) (err error)   { return EWINDOWS }
   977  
   978  func Getuid() (uid int)                  { return -1 }
   979  func Geteuid() (euid int)                { return -1 }
   980  func Getgid() (gid int)                  { return -1 }
   981  func Getegid() (egid int)                { return -1 }
   982  func Getgroups() (gids []int, err error) { return nil, EWINDOWS }
   983  
   984  type Signal int
   985  
   986  func (s Signal) Signal() {}
   987  
   988  func (s Signal) String() string {
   989  	if 0 <= s && int(s) < len(signals) {
   990  		str := signals[s]
   991  		if str != "" {
   992  			return str
   993  		}
   994  	}
   995  	return "signal " + itoa(int(s))
   996  }
   997  
   998  func LoadCreateSymbolicLink() error {
   999  	return procCreateSymbolicLinkW.Find()
  1000  }
  1001  
  1002  // Readlink returns the destination of the named symbolic link.
  1003  func Readlink(path string, buf []byte) (n int, err error) {
  1004  	fd, err := CreateFile(StringToUTF16Ptr(path), GENERIC_READ, 0, nil, OPEN_EXISTING,
  1005  		FILE_FLAG_OPEN_REPARSE_POINT|FILE_FLAG_BACKUP_SEMANTICS, 0)
  1006  	if err != nil {
  1007  		return -1, err
  1008  	}
  1009  	defer CloseHandle(fd)
  1010  
  1011  	rdbbuf := make([]byte, MAXIMUM_REPARSE_DATA_BUFFER_SIZE)
  1012  	var bytesReturned uint32
  1013  	err = DeviceIoControl(fd, FSCTL_GET_REPARSE_POINT, nil, 0, &rdbbuf[0], uint32(len(rdbbuf)), &bytesReturned, nil)
  1014  	if err != nil {
  1015  		return -1, err
  1016  	}
  1017  
  1018  	rdb := (*reparseDataBuffer)(unsafe.Pointer(&rdbbuf[0]))
  1019  	var s string
  1020  	switch rdb.ReparseTag {
  1021  	case IO_REPARSE_TAG_SYMLINK:
  1022  		data := (*symbolicLinkReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1023  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1024  		s = UTF16ToString(p[data.PrintNameOffset/2 : (data.PrintNameLength-data.PrintNameOffset)/2])
  1025  	case _IO_REPARSE_TAG_MOUNT_POINT:
  1026  		data := (*mountPointReparseBuffer)(unsafe.Pointer(&rdb.reparseBuffer))
  1027  		p := (*[0xffff]uint16)(unsafe.Pointer(&data.PathBuffer[0]))
  1028  		s = UTF16ToString(p[data.PrintNameOffset/2 : (data.PrintNameLength-data.PrintNameOffset)/2])
  1029  	default:
  1030  		// the path is not a symlink or junction but another type of reparse
  1031  		// point
  1032  		return -1, ENOENT
  1033  	}
  1034  	n = copy(buf, []byte(s))
  1035  
  1036  	return n, nil
  1037  }