all: update to use os.ReadDir where appropriate

os.ReadDir is a replacement for ioutil.ReadDir that returns
a slice of fs.DirEntry instead of fs.FileInfo, meaning it is the
more efficient form.

This CL updates call sites throughout the Go source tree
wherever possible. As usual, code built using the Go 1.4
bootstrap toolchain is not included. There is also a use in
go/build that appears in the public API and can't be changed,
at least not without additional changes.

Fixes #42026.

Change-Id: Icfc9dd52c6045020f6830e22c72128499462d561
Reviewed-on: https://go-review.googlesource.com/c/go/+/266366
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

1 files changed, 5 insertions, 6 deletions

diff --git a/src/cmd/go/internal/modcmd/vendor.go b/src/cmd/go/internal/modcmd/vendor.go
index 390a195547..1bbb57d353 100644
--- a/src/cmd/go/internal/modcmd/vendor.go
+++ b/src/cmd/go/internal/modcmd/vendor.go
@@ -10,7 +10,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -244,7 +243,7 @@ var metaPrefixes = []string{
 }
 
 // matchMetadata reports whether info is a metadata file.
-func matchMetadata(dir string, info fs.FileInfo) bool {
+func matchMetadata(dir string, info fs.DirEntry) bool {
 	name := info.Name()
 	for _, p := range metaPrefixes {
 		if strings.HasPrefix(name, p) {
@@ -255,7 +254,7 @@ func matchMetadata(dir string, info fs.FileInfo) bool {
 }
 
 // matchPotentialSourceFile reports whether info may be relevant to a build operation.
-func matchPotentialSourceFile(dir string, info fs.FileInfo) bool {
+func matchPotentialSourceFile(dir string, info fs.DirEntry) bool {
 	if strings.HasSuffix(info.Name(), "_test.go") {
 		return false
 	}
@@ -281,8 +280,8 @@ func matchPotentialSourceFile(dir string, info fs.FileInfo) bool {
 }
 
 // copyDir copies all regular files satisfying match(info) from src to dst.
-func copyDir(dst, src string, match func(dir string, info fs.FileInfo) bool) {
-	files, err := ioutil.ReadDir(src)
+func copyDir(dst, src string, match func(dir string, info fs.DirEntry) bool) {
+	files, err := os.ReadDir(src)
 	if err != nil {
 		base.Fatalf("go mod vendor: %v", err)
 	}
@@ -290,7 +289,7 @@ func copyDir(dst, src string, match func(dir string, info fs.FileInfo) bool) {
 		base.Fatalf("go mod vendor: %v", err)
 	}
 	for _, file := range files {
-		if file.IsDir() || !file.Mode().IsRegular() || !match(src, file) {
+		if file.IsDir() || !file.Type().IsRegular() || !match(src, file) {
 			continue
 		}
 		r, err := os.Open(filepath.Join(src, file.Name()))