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>

5 files changed, 18 insertions, 13 deletions

diff --git a/src/path/filepath/example_unix_walk_test.go b/src/path/filepath/example_unix_walk_test.go
index fa8b8e393b..66dc7f6b53 100644
--- a/src/path/filepath/example_unix_walk_test.go
+++ b/src/path/filepath/example_unix_walk_test.go
@@ -8,6 +8,7 @@ package filepath_test
 
 import (
 	"fmt"
+	"io/fs"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -40,7 +41,7 @@ func ExampleWalk() {
 	subDirToSkip := "skip"
 
 	fmt.Println("On Unix:")
-	err = filepath.Walk(".", func(path string, info os.FileInfo, err error) error {
+	err = filepath.Walk(".", func(path string, info fs.FileInfo, err error) error {
 		if err != nil {
 			fmt.Printf("prevent panic by handling failure accessing a path %q: %v\n", path, err)
 			return err
diff --git a/src/path/filepath/path.go b/src/path/filepath/path.go
index 26f1833189..dffd27db14 100644
--- a/src/path/filepath/path.go
+++ b/src/path/filepath/path.go
@@ -13,6 +13,7 @@ package filepath
 
 import (
 	"errors"
+	"io/fs"
 	"os"
 	"sort"
 	"strings"
@@ -339,7 +340,7 @@ var SkipDir = errors.New("skip this directory")
 // visited by Walk. The path argument contains the argument to Walk as a
 // prefix; that is, if Walk is called with "dir", which is a directory
 // containing the file "a", the walk function will be called with argument
-// "dir/a". The info argument is the os.FileInfo for the named path.
+// "dir/a". The info argument is the fs.FileInfo for the named path.
 //
 // If there was a problem walking to the file or directory named by path, the
 // incoming error will describe the problem and the function can decide how
@@ -350,12 +351,12 @@ var SkipDir = errors.New("skip this directory")
 // Walk skips the directory's contents entirely. If the function returns SkipDir
 // when invoked on a non-directory file, Walk skips the remaining files in the
 // containing directory.
-type WalkFunc func(path string, info os.FileInfo, err error) error
+type WalkFunc func(path string, info fs.FileInfo, err error) error
 
 var lstat = os.Lstat // for testing
 
 // walk recursively descends path, calling walkFn.
-func walk(path string, info os.FileInfo, walkFn WalkFunc) error {
+func walk(path string, info fs.FileInfo, walkFn WalkFunc) error {
 	if !info.IsDir() {
 		return walkFn(path, info, nil)
 	}
diff --git a/src/path/filepath/path_test.go b/src/path/filepath/path_test.go
index 6a8700e413..7dc8b60c28 100644
--- a/src/path/filepath/path_test.go
+++ b/src/path/filepath/path_test.go
@@ -8,6 +8,7 @@ import (
 	"errors"
 	"fmt"
 	"internal/testenv"
+	"io/fs"
 	"io/ioutil"
 	"os"
 	"path/filepath"
@@ -393,7 +394,7 @@ func checkMarks(t *testing.T, report bool) {
 // Assumes that each node name is unique. Good enough for a test.
 // If clear is true, any incoming error is cleared before return. The errors
 // are always accumulated, though.
-func mark(info os.FileInfo, err error, errors *[]error, clear bool) error {
+func mark(info fs.FileInfo, err error, errors *[]error, clear bool) error {
 	name := info.Name()
 	walkTree(tree, tree.name, func(path string, n *Node) {
 		if n.name == name {
@@ -454,7 +455,7 @@ func TestWalk(t *testing.T) {
 	makeTree(t)
 	errors := make([]error, 0, 10)
 	clear := true
-	markFn := func(path string, info os.FileInfo, err error) error {
+	markFn := func(path string, info fs.FileInfo, err error) error {
 		return mark(info, err, &errors, clear)
 	}
 	// Expect no errors.
@@ -543,7 +544,7 @@ func TestWalkSkipDirOnFile(t *testing.T) {
 	touch(t, filepath.Join(td, "dir/foo2"))
 
 	sawFoo2 := false
-	walker := func(path string, info os.FileInfo, err error) error {
+	walker := func(path string, info fs.FileInfo, err error) error {
 		if strings.HasSuffix(path, "foo2") {
 			sawFoo2 = true
 		}
@@ -589,14 +590,14 @@ func TestWalkFileError(t *testing.T) {
 		*filepath.LstatP = os.Lstat
 	}()
 	statErr := errors.New("some stat error")
-	*filepath.LstatP = func(path string) (os.FileInfo, error) {
+	*filepath.LstatP = func(path string) (fs.FileInfo, error) {
 		if strings.HasSuffix(path, "stat-error") {
 			return nil, statErr
 		}
 		return os.Lstat(path)
 	}
 	got := map[string]error{}
-	err = filepath.Walk(td, func(path string, fi os.FileInfo, err error) error {
+	err = filepath.Walk(td, func(path string, fi fs.FileInfo, err error) error {
 		rel, _ := filepath.Rel(td, path)
 		got[filepath.ToSlash(rel)] = err
 		return nil
@@ -1289,7 +1290,7 @@ func TestBug3486(t *testing.T) { // https://golang.org/issue/3486
 	ken := filepath.Join(root, "ken")
 	seenBugs := false
 	seenKen := false
-	err = filepath.Walk(root, func(pth string, info os.FileInfo, err error) error {
+	err = filepath.Walk(root, func(pth string, info fs.FileInfo, err error) error {
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -1338,7 +1339,7 @@ func testWalkSymlink(t *testing.T, mklink func(target, link string) error) {
 	}
 
 	var visited []string
-	err = filepath.Walk(tmpdir, func(path string, info os.FileInfo, err error) error {
+	err = filepath.Walk(tmpdir, func(path string, info fs.FileInfo, err error) error {
 		if err != nil {
 			t.Fatal(err)
 		}
diff --git a/src/path/filepath/path_windows_test.go b/src/path/filepath/path_windows_test.go
index f7c454bf65..990f18614d 100644
--- a/src/path/filepath/path_windows_test.go
+++ b/src/path/filepath/path_windows_test.go
@@ -8,6 +8,7 @@ import (
 	"flag"
 	"fmt"
 	"internal/testenv"
+	"io/fs"
 	"io/ioutil"
 	"os"
 	"os/exec"
@@ -34,7 +35,7 @@ func testWinSplitListTestIsValid(t *testing.T, ti int, tt SplitListTest,
 
 	const (
 		cmdfile             = `printdir.cmd`
-		perm    os.FileMode = 0700
+		perm    fs.FileMode = 0700
 	)
 
 	tmp, err := ioutil.TempDir("", "testWinSplitListTestIsValid")
diff --git a/src/path/filepath/symlink.go b/src/path/filepath/symlink.go
index 335b315a20..6fefd15977 100644
--- a/src/path/filepath/symlink.go
+++ b/src/path/filepath/symlink.go
@@ -6,6 +6,7 @@ package filepath
 
 import (
 	"errors"
+	"io/fs"
 	"os"
 	"runtime"
 	"syscall"
@@ -85,7 +86,7 @@ func walkSymlinks(path string) (string, error) {
 			return "", err
 		}
 
-		if fi.Mode()&os.ModeSymlink == 0 {
+		if fi.Mode()&fs.ModeSymlink == 0 {
 			if !fi.Mode().IsDir() && end < len(path) {
 				return "", syscall.ENOTDIR
 			}