all: update references to symbols moved from os to io/fs

The old os references are still valid, but update our code
to reflect best practices and get used to the new locations.

Code compiled with the bootstrap toolchain
(cmd/asm, cmd/dist, cmd/compile, debug/elf)
must remain Go 1.4-compatible and is excluded.

For #41190.

Change-Id: I8f9526977867c10a221e2f392f78d7dec073f1bd
Reviewed-on: https://go-review.googlesource.com/c/go/+/243907
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Rob Pike <r@golang.org>

6 files changed, 93 insertions, 91 deletions

diff --git a/src/archive/tar/common.go b/src/archive/tar/common.go
index dee9e47e4a..c667cfc872 100644
--- a/src/archive/tar/common.go
+++ b/src/archive/tar/common.go
@@ -13,8 +13,8 @@ package tar
 import (
 	"errors"
 	"fmt"
+	"io/fs"
 	"math"
-	"os"
 	"path"
 	"reflect"
 	"strconv"
@@ -525,12 +525,12 @@ func (h Header) allowedFormats() (format Format, paxHdrs map[string]string, err
 	return format, paxHdrs, err
 }
 
-// FileInfo returns an os.FileInfo for the Header.
-func (h *Header) FileInfo() os.FileInfo {
+// FileInfo returns an fs.FileInfo for the Header.
+func (h *Header) FileInfo() fs.FileInfo {
 	return headerFileInfo{h}
 }
 
-// headerFileInfo implements os.FileInfo.
+// headerFileInfo implements fs.FileInfo.
 type headerFileInfo struct {
 	h *Header
 }
@@ -549,57 +549,57 @@ func (fi headerFileInfo) Name() string {
 }
 
 // Mode returns the permission and mode bits for the headerFileInfo.
-func (fi headerFileInfo) Mode() (mode os.FileMode) {
+func (fi headerFileInfo) Mode() (mode fs.FileMode) {
 	// Set file permission bits.
-	mode = os.FileMode(fi.h.Mode).Perm()
+	mode = fs.FileMode(fi.h.Mode).Perm()
 
 	// Set setuid, setgid and sticky bits.
 	if fi.h.Mode&c_ISUID != 0 {
-		mode |= os.ModeSetuid
+		mode |= fs.ModeSetuid
 	}
 	if fi.h.Mode&c_ISGID != 0 {
-		mode |= os.ModeSetgid
+		mode |= fs.ModeSetgid
 	}
 	if fi.h.Mode&c_ISVTX != 0 {
-		mode |= os.ModeSticky
+		mode |= fs.ModeSticky
 	}
 
 	// Set file mode bits; clear perm, setuid, setgid, and sticky bits.
-	switch m := os.FileMode(fi.h.Mode) &^ 07777; m {
+	switch m := fs.FileMode(fi.h.Mode) &^ 07777; m {
 	case c_ISDIR:
-		mode |= os.ModeDir
+		mode |= fs.ModeDir
 	case c_ISFIFO:
-		mode |= os.ModeNamedPipe
+		mode |= fs.ModeNamedPipe
 	case c_ISLNK:
-		mode |= os.ModeSymlink
+		mode |= fs.ModeSymlink
 	case c_ISBLK:
-		mode |= os.ModeDevice
+		mode |= fs.ModeDevice
 	case c_ISCHR:
-		mode |= os.ModeDevice
-		mode |= os.ModeCharDevice
+		mode |= fs.ModeDevice
+		mode |= fs.ModeCharDevice
 	case c_ISSOCK:
-		mode |= os.ModeSocket
+		mode |= fs.ModeSocket
 	}
 
 	switch fi.h.Typeflag {
 	case TypeSymlink:
-		mode |= os.ModeSymlink
+		mode |= fs.ModeSymlink
 	case TypeChar:
-		mode |= os.ModeDevice
-		mode |= os.ModeCharDevice
+		mode |= fs.ModeDevice
+		mode |= fs.ModeCharDevice
 	case TypeBlock:
-		mode |= os.ModeDevice
+		mode |= fs.ModeDevice
 	case TypeDir:
-		mode |= os.ModeDir
+		mode |= fs.ModeDir
 	case TypeFifo:
-		mode |= os.ModeNamedPipe
+		mode |= fs.ModeNamedPipe
 	}
 
 	return mode
 }
 
 // sysStat, if non-nil, populates h from system-dependent fields of fi.
-var sysStat func(fi os.FileInfo, h *Header) error
+var sysStat func(fi fs.FileInfo, h *Header) error
 
 const (
 	// Mode constants from the USTAR spec:
@@ -623,10 +623,10 @@ const (
 // If fi describes a symlink, FileInfoHeader records link as the link target.
 // If fi describes a directory, a slash is appended to the name.
 //
-// Since os.FileInfo's Name method only returns the base name of
+// Since fs.FileInfo's Name method only returns the base name of
 // the file it describes, it may be necessary to modify Header.Name
 // to provide the full path name of the file.
-func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
+func FileInfoHeader(fi fs.FileInfo, link string) (*Header, error) {
 	if fi == nil {
 		return nil, errors.New("archive/tar: FileInfo is nil")
 	}
@@ -643,29 +643,29 @@ func FileInfoHeader(fi os.FileInfo, link string) (*Header, error) {
 	case fi.IsDir():
 		h.Typeflag = TypeDir
 		h.Name += "/"
-	case fm&os.ModeSymlink != 0:
+	case fm&fs.ModeSymlink != 0:
 		h.Typeflag = TypeSymlink
 		h.Linkname = link
-	case fm&os.ModeDevice != 0:
-		if fm&os.ModeCharDevice != 0 {
+	case fm&fs.ModeDevice != 0:
+		if fm&fs.ModeCharDevice != 0 {
 			h.Typeflag = TypeChar
 		} else {
 			h.Typeflag = TypeBlock
 		}
-	case fm&os.ModeNamedPipe != 0:
+	case fm&fs.ModeNamedPipe != 0:
 		h.Typeflag = TypeFifo
-	case fm&os.ModeSocket != 0:
+	case fm&fs.ModeSocket != 0:
 		return nil, fmt.Errorf("archive/tar: sockets not supported")
 	default:
 		return nil, fmt.Errorf("archive/tar: unknown file mode %v", fm)
 	}
-	if fm&os.ModeSetuid != 0 {
+	if fm&fs.ModeSetuid != 0 {
 		h.Mode |= c_ISUID
 	}
-	if fm&os.ModeSetgid != 0 {
+	if fm&fs.ModeSetgid != 0 {
 		h.Mode |= c_ISGID
 	}
-	if fm&os.ModeSticky != 0 {
+	if fm&fs.ModeSticky != 0 {
 		h.Mode |= c_ISVTX
 	}
 	// If possible, populate additional fields from OS-specific
diff --git a/src/archive/tar/stat_unix.go b/src/archive/tar/stat_unix.go
index 8df3616990..581d87dca9 100644
--- a/src/archive/tar/stat_unix.go
+++ b/src/archive/tar/stat_unix.go
@@ -7,7 +7,7 @@
 package tar
 
 import (
-	"os"
+	"io/fs"
 	"os/user"
 	"runtime"
 	"strconv"
@@ -23,7 +23,7 @@ func init() {
 // The downside is that renaming uname or gname by the OS never takes effect.
 var userMap, groupMap sync.Map // map[int]string
 
-func statUnix(fi os.FileInfo, h *Header) error {
+func statUnix(fi fs.FileInfo, h *Header) error {
 	sys, ok := fi.Sys().(*syscall.Stat_t)
 	if !ok {
 		return nil
diff --git a/src/archive/tar/tar_test.go b/src/archive/tar/tar_test.go
index 2676853122..f605dae904 100644
--- a/src/archive/tar/tar_test.go
+++ b/src/archive/tar/tar_test.go
@@ -10,6 +10,7 @@ import (
 	"fmt"
 	"internal/testenv"
 	"io"
+	"io/fs"
 	"io/ioutil"
 	"math"
 	"os"
@@ -338,7 +339,7 @@ func TestRoundTrip(t *testing.T) {
 
 type headerRoundTripTest struct {
 	h  *Header
-	fm os.FileMode
+	fm fs.FileMode
 }
 
 func TestHeaderRoundTrip(t *testing.T) {
@@ -361,7 +362,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1360600852, 0),
 			Typeflag: TypeSymlink,
 		},
-		fm: 0777 | os.ModeSymlink,
+		fm: 0777 | fs.ModeSymlink,
 	}, {
 		// character device node.
 		h: &Header{
@@ -371,7 +372,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1360578951, 0),
 			Typeflag: TypeChar,
 		},
-		fm: 0666 | os.ModeDevice | os.ModeCharDevice,
+		fm: 0666 | fs.ModeDevice | fs.ModeCharDevice,
 	}, {
 		// block device node.
 		h: &Header{
@@ -381,7 +382,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1360578954, 0),
 			Typeflag: TypeBlock,
 		},
-		fm: 0660 | os.ModeDevice,
+		fm: 0660 | fs.ModeDevice,
 	}, {
 		// directory.
 		h: &Header{
@@ -391,7 +392,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1360601116, 0),
 			Typeflag: TypeDir,
 		},
-		fm: 0755 | os.ModeDir,
+		fm: 0755 | fs.ModeDir,
 	}, {
 		// fifo node.
 		h: &Header{
@@ -401,7 +402,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1360578949, 0),
 			Typeflag: TypeFifo,
 		},
-		fm: 0600 | os.ModeNamedPipe,
+		fm: 0600 | fs.ModeNamedPipe,
 	}, {
 		// setuid.
 		h: &Header{
@@ -411,7 +412,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1355405093, 0),
 			Typeflag: TypeReg,
 		},
-		fm: 0755 | os.ModeSetuid,
+		fm: 0755 | fs.ModeSetuid,
 	}, {
 		// setguid.
 		h: &Header{
@@ -421,7 +422,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1360602346, 0),
 			Typeflag: TypeReg,
 		},
-		fm: 0750 | os.ModeSetgid,
+		fm: 0750 | fs.ModeSetgid,
 	}, {
 		// sticky.
 		h: &Header{
@@ -431,7 +432,7 @@ func TestHeaderRoundTrip(t *testing.T) {
 			ModTime:  time.Unix(1360602540, 0),
 			Typeflag: TypeReg,
 		},
-		fm: 0600 | os.ModeSticky,
+		fm: 0600 | fs.ModeSticky,
 	}, {
 		// hard link.
 		h: &Header{
diff --git a/src/archive/zip/reader_test.go b/src/archive/zip/reader_test.go
index adca87a8b3..8a32d9c7dc 100644
--- a/src/archive/zip/reader_test.go
+++ b/src/archive/zip/reader_test.go
@@ -10,6 +10,7 @@ import (
 	"encoding/hex"
 	"internal/obscuretestdata"
 	"io"
+	"io/fs"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -30,7 +31,7 @@ type ZipTest struct {
 
 type ZipTestFile struct {
 	Name     string
-	Mode     os.FileMode
+	Mode     fs.FileMode
 	NonUTF8  bool
 	ModTime  time.Time
 	Modified time.Time
@@ -107,7 +108,7 @@ var tests = []ZipTest{
 				Name:     "symlink",
 				Content:  []byte("../target"),
 				Modified: time.Date(2012, 2, 3, 19, 56, 48, 0, timeZone(-2*time.Hour)),
-				Mode:     0777 | os.ModeSymlink,
+				Mode:     0777 | fs.ModeSymlink,
 			},
 		},
 	},
@@ -149,7 +150,7 @@ var tests = []ZipTest{
 				Name:     "dir/empty/",
 				Content:  []byte{},
 				Modified: time.Date(2011, 12, 8, 10, 8, 6, 0, time.UTC),
-				Mode:     os.ModeDir | 0777,
+				Mode:     fs.ModeDir | 0777,
 			},
 			{
 				Name:     "readonly",
@@ -179,7 +180,7 @@ var tests = []ZipTest{
 				Name:     "dir/empty/",
 				Content:  []byte{},
 				Modified: time.Date(2011, 12, 8, 10, 8, 6, 0, timeZone(0)),
-				Mode:     os.ModeDir | 0777,
+				Mode:     fs.ModeDir | 0777,
 			},
 			{
 				Name:     "readonly",
@@ -645,7 +646,7 @@ func readTestFile(t *testing.T, zt ZipTest, ft ZipTestFile, f *File) {
 	}
 }
 
-func testFileMode(t *testing.T, f *File, want os.FileMode) {
+func testFileMode(t *testing.T, f *File, want fs.FileMode) {
 	mode := f.Mode()
 	if want == 0 {
 		t.Errorf("%s mode: got %v, want none", f.Name, mode)
diff --git a/src/archive/zip/struct.go b/src/archive/zip/struct.go
index 686e79781a..355c57051b 100644
--- a/src/archive/zip/struct.go
+++ b/src/archive/zip/struct.go
@@ -20,7 +20,7 @@ fields must be used instead.
 package zip
 
 import (
-	"os"
+	"io/fs"
 	"path"
 	"time"
 )
@@ -137,12 +137,12 @@ type FileHeader struct {
 	ExternalAttrs      uint32 // Meaning depends on CreatorVersion
 }
 
-// FileInfo returns an os.FileInfo for the FileHeader.
-func (h *FileHeader) FileInfo() os.FileInfo {
+// FileInfo returns an fs.FileInfo for the FileHeader.
+func (h *FileHeader) FileInfo() fs.FileInfo {
 	return headerFileInfo{h}
 }
 
-// headerFileInfo implements os.FileInfo.
+// headerFileInfo implements fs.FileInfo.
 type headerFileInfo struct {
 	fh *FileHeader
 }
@@ -161,17 +161,17 @@ func (fi headerFileInfo) ModTime() time.Time {
 	}
 	return fi.fh.Modified.UTC()
 }
-func (fi headerFileInfo) Mode() os.FileMode { return fi.fh.Mode() }
+func (fi headerFileInfo) Mode() fs.FileMode { return fi.fh.Mode() }
 func (fi headerFileInfo) Sys() interface{}  { return fi.fh }
 
 // FileInfoHeader creates a partially-populated FileHeader from an
-// os.FileInfo.
-// Because os.FileInfo's Name method returns only the base name of
+// fs.FileInfo.
+// Because fs.FileInfo's Name method returns only the base name of
 // the file it describes, it may be necessary to modify the Name field
 // of the returned header to provide the full path name of the file.
 // If compression is desired, callers should set the FileHeader.Method
 // field; it is unset by default.
-func FileInfoHeader(fi os.FileInfo) (*FileHeader, error) {
+func FileInfoHeader(fi fs.FileInfo) (*FileHeader, error) {
 	size := fi.Size()
 	fh := &FileHeader{
 		Name:               fi.Name(),
@@ -280,7 +280,7 @@ const (
 )
 
 // Mode returns the permission and mode bits for the FileHeader.
-func (h *FileHeader) Mode() (mode os.FileMode) {
+func (h *FileHeader) Mode() (mode fs.FileMode) {
 	switch h.CreatorVersion >> 8 {
 	case creatorUnix, creatorMacOSX:
 		mode = unixModeToFileMode(h.ExternalAttrs >> 16)
@@ -288,18 +288,18 @@ func (h *FileHeader) Mode() (mode os.FileMode) {
 		mode = msdosModeToFileMode(h.ExternalAttrs)
 	}
 	if len(h.Name) > 0 && h.Name[len(h.Name)-1] == '/' {
-		mode |= os.ModeDir
+		mode |= fs.ModeDir
 	}
 	return mode
 }
 
 // SetMode changes the permission and mode bits for the FileHeader.
-func (h *FileHeader) SetMode(mode os.FileMode) {
+func (h *FileHeader) SetMode(mode fs.FileMode) {
 	h.CreatorVersion = h.CreatorVersion&0xff | creatorUnix<<8
 	h.ExternalAttrs = fileModeToUnixMode(mode) << 16
 
 	// set MSDOS attributes too, as the original zip does.
-	if mode&os.ModeDir != 0 {
+	if mode&fs.ModeDir != 0 {
 		h.ExternalAttrs |= msdosDir
 	}
 	if mode&0200 == 0 {
@@ -312,9 +312,9 @@ func (h *FileHeader) isZip64() bool {
 	return h.CompressedSize64 >= uint32max || h.UncompressedSize64 >= uint32max
 }
 
-func msdosModeToFileMode(m uint32) (mode os.FileMode) {
+func msdosModeToFileMode(m uint32) (mode fs.FileMode) {
 	if m&msdosDir != 0 {
-		mode = os.ModeDir | 0777
+		mode = fs.ModeDir | 0777
 	} else {
 		mode = 0666
 	}
@@ -324,64 +324,64 @@ func msdosModeToFileMode(m uint32) (mode os.FileMode) {
 	return mode
 }
 
-func fileModeToUnixMode(mode os.FileMode) uint32 {
+func fileModeToUnixMode(mode fs.FileMode) uint32 {
 	var m uint32
-	switch mode & os.ModeType {
+	switch mode & fs.ModeType {
 	default:
 		m = s_IFREG
-	case os.ModeDir:
+	case fs.ModeDir:
 		m = s_IFDIR
-	case os.ModeSymlink:
+	case fs.ModeSymlink:
 		m = s_IFLNK
-	case os.ModeNamedPipe:
+	case fs.ModeNamedPipe:
 		m = s_IFIFO
-	case os.ModeSocket:
+	case fs.ModeSocket:
 		m = s_IFSOCK
-	case os.ModeDevice:
-		if mode&os.ModeCharDevice != 0 {
+	case fs.ModeDevice:
+		if mode&fs.ModeCharDevice != 0 {
 			m = s_IFCHR
 		} else {
 			m = s_IFBLK
 		}
 	}
-	if mode&os.ModeSetuid != 0 {
+	if mode&fs.ModeSetuid != 0 {
 		m |= s_ISUID
 	}
-	if mode&os.ModeSetgid != 0 {
+	if mode&fs.ModeSetgid != 0 {
 		m |= s_ISGID
 	}
-	if mode&os.ModeSticky != 0 {
+	if mode&fs.ModeSticky != 0 {
 		m |= s_ISVTX
 	}
 	return m | uint32(mode&0777)
 }
 
-func unixModeToFileMode(m uint32) os.FileMode {
-	mode := os.FileMode(m & 0777)
+func unixModeToFileMode(m uint32) fs.FileMode {
+	mode := fs.FileMode(m & 0777)
 	switch m & s_IFMT {
 	case s_IFBLK:
-		mode |= os.ModeDevice
+		mode |= fs.ModeDevice
 	case s_IFCHR:
-		mode |= os.ModeDevice | os.ModeCharDevice
+		mode |= fs.ModeDevice | fs.ModeCharDevice
 	case s_IFDIR:
-		mode |= os.ModeDir
+		mode |= fs.ModeDir
 	case s_IFIFO:
-		mode |= os.ModeNamedPipe
+		mode |= fs.ModeNamedPipe
 	case s_IFLNK:
-		mode |= os.ModeSymlink
+		mode |= fs.ModeSymlink
 	case s_IFREG:
 		// nothing to do
 	case s_IFSOCK:
-		mode |= os.ModeSocket
+		mode |= fs.ModeSocket
 	}
 	if m&s_ISGID != 0 {
-		mode |= os.ModeSetgid
+		mode |= fs.ModeSetgid
 	}
 	if m&s_ISUID != 0 {
-		mode |= os.ModeSetuid
+		mode |= fs.ModeSetuid
 	}
 	if m&s_ISVTX != 0 {
-		mode |= os.ModeSticky
+		mode |= fs.ModeSticky
 	}
 	return mode
 }
diff --git a/src/archive/zip/writer_test.go b/src/archive/zip/writer_test.go
index 1fedfd85e8..282f9ec216 100644
--- a/src/archive/zip/writer_test.go
+++ b/src/archive/zip/writer_test.go
@@ -9,9 +9,9 @@ import (
 	"encoding/binary"
 	"fmt"
 	"io"
+	"io/fs"
 	"io/ioutil"
 	"math/rand"
-	"os"
 	"strings"
 	"testing"
 	"time"
@@ -23,7 +23,7 @@ type WriteTest struct {
 	Name   string
 	Data   []byte
 	Method uint16
-	Mode   os.FileMode
+	Mode   fs.FileMode
 }
 
 var writeTests = []WriteTest{
@@ -43,19 +43,19 @@ var writeTests = []WriteTest{
 		Name:   "setuid",
 		Data:   []byte("setuid file"),
 		Method: Deflate,
-		Mode:   0755 | os.ModeSetuid,
+		Mode:   0755 | fs.ModeSetuid,
 	},
 	{
 		Name:   "setgid",
 		Data:   []byte("setgid file"),
 		Method: Deflate,
-		Mode:   0755 | os.ModeSetgid,
+		Mode:   0755 | fs.ModeSetgid,
 	},
 	{
 		Name:   "symlink",
 		Data:   []byte("../link/target"),
 		Method: Deflate,
-		Mode:   0755 | os.ModeSymlink,
+		Mode:   0755 | fs.ModeSymlink,
 	},
 }