all: replace package ioutil with os and io in src

For #45557

Change-Id: I56824135d86452603dd4ed4bab0e24c201bb0683
Reviewed-on: https://go-review.googlesource.com/c/go/+/426257
Run-TryBot: Ian Lance Taylor <iant@google.com>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Run-TryBot: Andy Pan <panjf2000@gmail.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@google.com>

3 files changed, 10 insertions, 12 deletions

diff --git a/src/cmd/compile/internal/syntax/error_test.go b/src/cmd/compile/internal/syntax/error_test.go
index 2f70b5278e..55ea6345b9 100644
--- a/src/cmd/compile/internal/syntax/error_test.go
+++ b/src/cmd/compile/internal/syntax/error_test.go
@@ -32,7 +32,6 @@ import (
 	"flag"
 	"fmt"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -178,7 +177,7 @@ func testSyntaxErrors(t *testing.T, filename string) {
 func TestSyntaxErrors(t *testing.T) {
 	testenv.MustHaveGoBuild(t) // we need access to source (testdata)
 
-	list, err := ioutil.ReadDir(testdata)
+	list, err := os.ReadDir(testdata)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/src/cmd/compile/internal/syntax/parser_test.go b/src/cmd/compile/internal/syntax/parser_test.go
index b3d4573935..74583ca903 100644
--- a/src/cmd/compile/internal/syntax/parser_test.go
+++ b/src/cmd/compile/internal/syntax/parser_test.go
@@ -9,7 +9,7 @@ import (
 	"flag"
 	"fmt"
 	"internal/testenv"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"regexp"
 	"runtime"
@@ -112,21 +112,21 @@ func TestStdLib(t *testing.T) {
 }
 
 func walkDirs(t *testing.T, dir string, action func(string)) {
-	fis, err := ioutil.ReadDir(dir)
+	entries, err := os.ReadDir(dir)
 	if err != nil {
 		t.Error(err)
 		return
 	}
 
 	var files, dirs []string
-	for _, fi := range fis {
-		if fi.Mode().IsRegular() {
-			if strings.HasSuffix(fi.Name(), ".go") {
-				path := filepath.Join(dir, fi.Name())
+	for _, entry := range entries {
+		if entry.Type().IsRegular() {
+			if strings.HasSuffix(entry.Name(), ".go") {
+				path := filepath.Join(dir, entry.Name())
 				files = append(files, path)
 			}
-		} else if fi.IsDir() && fi.Name() != "testdata" {
-			path := filepath.Join(dir, fi.Name())
+		} else if entry.IsDir() && entry.Name() != "testdata" {
+			path := filepath.Join(dir, entry.Name())
 			if !strings.HasSuffix(path, string(filepath.Separator)+"test") {
 				dirs = append(dirs, path)
 			}
diff --git a/src/cmd/compile/internal/syntax/printer_test.go b/src/cmd/compile/internal/syntax/printer_test.go
index 863713c12d..ceb512ef89 100644
--- a/src/cmd/compile/internal/syntax/printer_test.go
+++ b/src/cmd/compile/internal/syntax/printer_test.go
@@ -7,7 +7,6 @@ package syntax
 import (
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"strings"
 	"testing"
@@ -155,7 +154,7 @@ func testOut() io.Writer {
 	if testing.Verbose() {
 		return os.Stdout
 	}
-	return ioutil.Discard
+	return io.Discard
 }
 
 func dup(s string) [2]string { return [2]string{s, s} }