From ae3ad0ab21d4c42c760332c306722581e09c9ef7 Mon Sep 17 00:00:00 2001
From: KimMachineGun <geon0250@gmail.com>
Date: Mon, 30 Nov 2020 02:04:43 +0900
Subject: [PATCH 1/4] all: update references to symbols moved from io/ioutil to
 io

---
 misc/android/go_android_exec.go                  | 2 +-
 misc/cgo/testcarchive/testdata/libgo6/sigprof.go | 4 ++--
 misc/cgo/testsanitizers/testdata/tsan9.go        | 4 ++--
 misc/linkcheck/linkcheck.go                      | 4 ++--
 src/net/http/fs_test.go                          | 2 +-
 src/testing/fstest/testfs.go                     | 3 +--
 test/bench/go1/gob_test.go                       | 4 ++--
 test/bench/go1/gzip_test.go                      | 5 ++---
 test/bench/go1/http_test.go                      | 4 ++--
 test/bench/go1/json_test.go                      | 3 +--
 test/bench/go1/parser_test.go                    | 3 +--
 test/bench/go1/revcomp_test.go                   | 4 ++--
 test/bench/go1/template_test.go                  | 4 ++--
 test/stress/runstress.go                         | 3 +--
 14 files changed, 22 insertions(+), 27 deletions(-)

diff --git a/misc/android/go_android_exec.go b/misc/android/go_android_exec.go
index 7aa7fe56fc5e04..35b160fc9f0b04 100644
--- a/misc/android/go_android_exec.go
+++ b/misc/android/go_android_exec.go
@@ -276,7 +276,7 @@ func adbCopyGoroot() error {
 	if err := syscall.Flock(int(stat.Fd()), syscall.LOCK_EX); err != nil {
 		return err
 	}
-	s, err := ioutil.ReadAll(stat)
+	s, err := io.ReadAll(stat)
 	if err != nil {
 		return err
 	}
diff --git a/misc/cgo/testcarchive/testdata/libgo6/sigprof.go b/misc/cgo/testcarchive/testdata/libgo6/sigprof.go
index 4cb05dc61786ab..31527c59af1213 100644
--- a/misc/cgo/testcarchive/testdata/libgo6/sigprof.go
+++ b/misc/cgo/testcarchive/testdata/libgo6/sigprof.go
@@ -5,7 +5,7 @@
 package main
 
 import (
-	"io/ioutil"
+	"io"
 	"runtime/pprof"
 )
 
@@ -13,7 +13,7 @@ import "C"
 
 //export go_start_profile
 func go_start_profile() {
-	pprof.StartCPUProfile(ioutil.Discard)
+	pprof.StartCPUProfile(io.Discard)
 }
 
 //export go_stop_profile
diff --git a/misc/cgo/testsanitizers/testdata/tsan9.go b/misc/cgo/testsanitizers/testdata/tsan9.go
index f166d8b495ac45..06304be751b5e2 100644
--- a/misc/cgo/testsanitizers/testdata/tsan9.go
+++ b/misc/cgo/testsanitizers/testdata/tsan9.go
@@ -44,7 +44,7 @@ void spin() {
 import "C"
 
 import (
-	"io/ioutil"
+	"io"
 	"runtime/pprof"
 	"time"
 )
@@ -60,7 +60,7 @@ func goSpin() {
 }
 
 func main() {
-	pprof.StartCPUProfile(ioutil.Discard)
+	pprof.StartCPUProfile(io.Discard)
 	go C.spin()
 	goSpin()
 	pprof.StopCPUProfile()
diff --git a/misc/linkcheck/linkcheck.go b/misc/linkcheck/linkcheck.go
index d9bfd2f767eb19..570b430da4f1cb 100644
--- a/misc/linkcheck/linkcheck.go
+++ b/misc/linkcheck/linkcheck.go
@@ -11,7 +11,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
-	"io/ioutil"
+	"io"
 	"log"
 	"net/http"
 	"os"
@@ -144,7 +144,7 @@ func doCrawl(url string) error {
 	if res.StatusCode != 200 {
 		return errors.New(res.Status)
 	}
-	slurp, err := ioutil.ReadAll(res.Body)
+	slurp, err := io.ReadAll(res.Body)
 	res.Body.Close()
 	if err != nil {
 		log.Fatalf("Error reading %s body: %v", url, err)
diff --git a/src/net/http/fs_test.go b/src/net/http/fs_test.go
index 2499051625081b..f9cfa91d4b03d3 100644
--- a/src/net/http/fs_test.go
+++ b/src/net/http/fs_test.go
@@ -593,7 +593,7 @@ func TestServeIndexHtml(t *testing.T) {
 				if err != nil {
 					t.Fatal(err)
 				}
-				b, err := ioutil.ReadAll(res.Body)
+				b, err := io.ReadAll(res.Body)
 				if err != nil {
 					t.Fatal("reading Body:", err)
 				}
diff --git a/src/testing/fstest/testfs.go b/src/testing/fstest/testfs.go
index e0ad60a17b6a15..80ca0e9a1d7fde 100644
--- a/src/testing/fstest/testfs.go
+++ b/src/testing/fstest/testfs.go
@@ -10,7 +10,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"path"
 	"reflect"
 	"sort"
@@ -514,7 +513,7 @@ func (t *fsTester) checkFile(file string) {
 		return
 	}
 
-	data, err := ioutil.ReadAll(f)
+	data, err := io.ReadAll(f)
 	if err != nil {
 		f.Close()
 		t.errorf("%s: Open+ReadAll: %v", file, err)
diff --git a/test/bench/go1/gob_test.go b/test/bench/go1/gob_test.go
index 224beff6801760..f289fcca7c7af2 100644
--- a/test/bench/go1/gob_test.go
+++ b/test/bench/go1/gob_test.go
@@ -10,7 +10,7 @@ import (
 	"bytes"
 	"encoding/gob"
 	"encoding/json"
-	"io/ioutil"
+	"io"
 	"log"
 	"reflect"
 	"testing"
@@ -73,7 +73,7 @@ func gobdec() {
 }
 
 func gobenc() {
-	if err := gob.NewEncoder(ioutil.Discard).Encode(&gobdata); err != nil {
+	if err := gob.NewEncoder(io.Discard).Encode(&gobdata); err != nil {
 		panic(err)
 	}
 }
diff --git a/test/bench/go1/gzip_test.go b/test/bench/go1/gzip_test.go
index 648eec5d457843..d3f98da11d81d6 100644
--- a/test/bench/go1/gzip_test.go
+++ b/test/bench/go1/gzip_test.go
@@ -10,7 +10,6 @@ import (
 	"bytes"
 	gz "compress/gzip"
 	"io"
-	"io/ioutil"
 	"testing"
 )
 
@@ -28,7 +27,7 @@ func init() {
 }
 
 func gzip() {
-	c := gz.NewWriter(ioutil.Discard)
+	c := gz.NewWriter(io.Discard)
 	if _, err := c.Write(jsongunz); err != nil {
 		panic(err)
 	}
@@ -42,7 +41,7 @@ func gunzip() {
 	if err != nil {
 		panic(err)
 	}
-	if _, err := io.Copy(ioutil.Discard, r); err != nil {
+	if _, err := io.Copy(io.Discard, r); err != nil {
 		panic(err)
 	}
 	r.Close()
diff --git a/test/bench/go1/http_test.go b/test/bench/go1/http_test.go
index 7ece9b2ac54878..08583d635da3a2 100644
--- a/test/bench/go1/http_test.go
+++ b/test/bench/go1/http_test.go
@@ -6,7 +6,7 @@ package go1
 
 import (
 	"bytes"
-	"io/ioutil"
+	"io"
 	"net/http"
 	"net/http/httptest"
 	"testing"
@@ -34,7 +34,7 @@ func BenchmarkHTTPClientServer(b *testing.B) {
 		if err != nil {
 			b.Fatal("Get:", err)
 		}
-		all, err := ioutil.ReadAll(res.Body)
+		all, err := io.ReadAll(res.Body)
 		if err != nil {
 			b.Fatal("ReadAll:", err)
 		}
diff --git a/test/bench/go1/json_test.go b/test/bench/go1/json_test.go
index 5ff1f8b6506874..782ef7674c1461 100644
--- a/test/bench/go1/json_test.go
+++ b/test/bench/go1/json_test.go
@@ -12,7 +12,6 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"io"
-	"io/ioutil"
 	"testing"
 )
 
@@ -26,7 +25,7 @@ func makeJsonBytes() []byte {
 	r = bytes.NewReader(bytes.Replace(jsonbz2_base64, []byte{'\n'}, nil, -1))
 	r = base64.NewDecoder(base64.StdEncoding, r)
 	r = bzip2.NewReader(r)
-	b, err := ioutil.ReadAll(r)
+	b, err := io.ReadAll(r)
 	if err != nil {
 		panic(err)
 	}
diff --git a/test/bench/go1/parser_test.go b/test/bench/go1/parser_test.go
index 7848cadd228e6d..8b7baa347963da 100644
--- a/test/bench/go1/parser_test.go
+++ b/test/bench/go1/parser_test.go
@@ -12,7 +12,6 @@ import (
 	"go/parser"
 	"go/token"
 	"io"
-	"io/ioutil"
 	"strings"
 	"testing"
 )
@@ -26,7 +25,7 @@ func makeParserBytes() []byte {
 	r = strings.NewReader(parserbz2_base64)
 	r = base64.NewDecoder(base64.StdEncoding, r)
 	r = bzip2.NewReader(r)
-	b, err := ioutil.ReadAll(r)
+	b, err := io.ReadAll(r)
 	if err != nil {
 		panic(err)
 	}
diff --git a/test/bench/go1/revcomp_test.go b/test/bench/go1/revcomp_test.go
index 7d57bd607b684d..c2e2c39baf736f 100644
--- a/test/bench/go1/revcomp_test.go
+++ b/test/bench/go1/revcomp_test.go
@@ -10,7 +10,7 @@ package go1
 import (
 	"bufio"
 	"bytes"
-	"io/ioutil"
+	"io"
 	"testing"
 )
 
@@ -35,7 +35,7 @@ var revCompTable = [256]uint8{
 
 func revcomp(data []byte) {
 	in := bufio.NewReader(bytes.NewBuffer(data))
-	out := ioutil.Discard
+	out := io.Discard
 	buf := make([]byte, 1024*1024)
 	line, err := in.ReadSlice('\n')
 	for err == nil {
diff --git a/test/bench/go1/template_test.go b/test/bench/go1/template_test.go
index 10dacaa35f6dc0..b7e98d5c2099e3 100644
--- a/test/bench/go1/template_test.go
+++ b/test/bench/go1/template_test.go
@@ -9,7 +9,7 @@ package go1
 
 import (
 	"bytes"
-	"io/ioutil"
+	"io"
 	"strings"
 	"testing"
 	"text/template"
@@ -63,7 +63,7 @@ func init() {
 }
 
 func tmplexec() {
-	if err := tmpl.Execute(ioutil.Discard, &jsondata); err != nil {
+	if err := tmpl.Execute(io.Discard, &jsondata); err != nil {
 		panic(err)
 	}
 }
diff --git a/test/stress/runstress.go b/test/stress/runstress.go
index 3f16fc9fb3fa87..b752fa8dbbc31f 100644
--- a/test/stress/runstress.go
+++ b/test/stress/runstress.go
@@ -12,7 +12,6 @@ import (
 	"flag"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"log"
 	"math/rand"
 	"net"
@@ -70,7 +69,7 @@ func stressNet() {
 		if res.StatusCode != 200 {
 			log.Fatalf("stressNet: Status code = %d", res.StatusCode)
 		}
-		n, err := io.Copy(ioutil.Discard, res.Body)
+		n, err := io.Copy(io.Discard, res.Body)
 		if err != nil {
 			log.Fatalf("stressNet: io.Copy: %v", err)
 		}

From 95457872e128192416873934526a124249d50fb1 Mon Sep 17 00:00:00 2001
From: KimMachineGun <geon0250@gmail.com>
Date: Fri, 19 Mar 2021 11:06:02 +0900
Subject: [PATCH 2/4] net/http: remove unused import

---
 src/net/http/fs_test.go | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/net/http/fs_test.go b/src/net/http/fs_test.go
index f9cfa91d4b03d3..0ebb511b5c5943 100644
--- a/src/net/http/fs_test.go
+++ b/src/net/http/fs_test.go
@@ -11,7 +11,6 @@ import (
 	"fmt"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"mime"
 	"mime/multipart"
 	"net"

From 05224305d24f1aa06cad17bdf4a50ad87135e038 Mon Sep 17 00:00:00 2001
From: KimMachineGun <geon0250@gmail.com>
Date: Fri, 19 Mar 2021 11:39:09 +0900
Subject: [PATCH 3/4] all: update references to symbols moved from io/ioutil to
 io

---
 misc/android/go_android_exec.go         |  3 +--
 misc/cgo/errors/badsym_test.go          |  7 +++---
 misc/cgo/errors/errors_test.go          |  5 ++--
 misc/cgo/errors/ptr_test.go             |  9 +++----
 misc/cgo/life/life_test.go              |  5 ++--
 misc/cgo/stdio/stdio_test.go            |  5 ++--
 misc/cgo/test/issue1435.go              |  6 ++---
 misc/cgo/test/pkg_test.go               |  5 ++--
 misc/cgo/testcarchive/carchive_test.go  | 11 ++++-----
 misc/cgo/testcshared/cshared_test.go    | 17 ++++++-------
 misc/cgo/testgodefs/testgodefs_test.go  | 11 ++++-----
 misc/cgo/testplugin/plugin_test.go      |  9 +++----
 misc/cgo/testsanitizers/cc_test.go      |  9 +++----
 misc/cgo/testsanitizers/cshared_test.go |  4 +--
 misc/cgo/testshared/shared_test.go      | 13 +++++-----
 misc/cgo/testso/so_test.go              |  5 ++--
 misc/cgo/testsovar/so_test.go           |  5 ++--
 misc/ios/detect.go                      |  3 +--
 misc/ios/go_ios_exec.go                 |  9 +++----
 misc/reboot/experiment_toolid_test.go   |  7 +++---
 misc/reboot/reboot_test.go              |  5 ++--
 src/go/build/build.go                   |  1 +
 src/go/types/check_test.go              |  3 +--
 src/internal/execabs/execabs_test.go    |  5 ++--
 src/syscall/exec_windows_test.go        |  3 +--
 test/const7.go                          |  3 +--
 test/fixedbugs/bug302.go                |  3 +--
 test/fixedbugs/bug369.go                |  3 +--
 test/fixedbugs/issue11771.go            |  5 ++--
 test/fixedbugs/issue13268.go            |  3 +--
 test/fixedbugs/issue16037_run.go        |  5 ++--
 test/fixedbugs/issue19658.go            |  5 ++--
 test/fixedbugs/issue21317.go            |  3 +--
 test/fixedbugs/issue21576.go            |  5 ++--
 test/fixedbugs/issue22660.go            |  5 ++--
 test/fixedbugs/issue22662b.go           |  5 ++--
 test/fixedbugs/issue26411.go            |  5 ++--
 test/fixedbugs/issue30908.dir/b.go      |  4 +--
 test/fixedbugs/issue33555.go            |  5 ++--
 test/fixedbugs/issue36437.go            |  3 +--
 test/fixedbugs/issue9355.go             |  3 +--
 test/linkmain_run.go                    |  3 +--
 test/linkobj.go                         |  9 +++----
 test/nosplit.go                         |  9 +++----
 test/run.go                             | 33 ++++++++++++-------------
 test/sinit_run.go                       |  3 +--
 test/winbatch.go                        |  3 +--
 47 files changed, 124 insertions(+), 166 deletions(-)

diff --git a/misc/android/go_android_exec.go b/misc/android/go_android_exec.go
index 35b160fc9f0b04..3af2bee5839b93 100644
--- a/misc/android/go_android_exec.go
+++ b/misc/android/go_android_exec.go
@@ -14,7 +14,6 @@ import (
 	"fmt"
 	"go/build"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -294,7 +293,7 @@ func adbCopyGoroot() error {
 	goroot := runtime.GOROOT()
 	// Build go for android.
 	goCmd := filepath.Join(goroot, "bin", "go")
-	tmpGo, err := ioutil.TempFile("", "go_android_exec-cmd-go-*")
+	tmpGo, err := os.CreateTemp("", "go_android_exec-cmd-go-*")
 	if err != nil {
 		return err
 	}
diff --git a/misc/cgo/errors/badsym_test.go b/misc/cgo/errors/badsym_test.go
index b2701bf922e529..fc687567bf71b2 100644
--- a/misc/cgo/errors/badsym_test.go
+++ b/misc/cgo/errors/badsym_test.go
@@ -6,7 +6,6 @@ package errorstest
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -55,7 +54,7 @@ func TestBadSymbol(t *testing.T) {
 
 	makeFile := func(mdir, base, source string) string {
 		ret := filepath.Join(mdir, base)
-		if err := ioutil.WriteFile(ret, []byte(source), 0644); err != nil {
+		if err := os.WriteFile(ret, []byte(source), 0644); err != nil {
 			t.Fatal(err)
 		}
 		return ret
@@ -100,7 +99,7 @@ func TestBadSymbol(t *testing.T) {
 	// _cgo_import.go.
 
 	rewrite := func(from, to string) {
-		obj, err := ioutil.ReadFile(from)
+		obj, err := os.ReadFile(from)
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -115,7 +114,7 @@ func TestBadSymbol(t *testing.T) {
 
 		obj = bytes.ReplaceAll(obj, []byte(magicInput), []byte(magicReplace))
 
-		if err := ioutil.WriteFile(to, obj, 0644); err != nil {
+		if err := os.WriteFile(to, obj, 0644); err != nil {
 			t.Fatal(err)
 		}
 	}
diff --git a/misc/cgo/errors/errors_test.go b/misc/cgo/errors/errors_test.go
index 1bdf843451d366..a077b594786213 100644
--- a/misc/cgo/errors/errors_test.go
+++ b/misc/cgo/errors/errors_test.go
@@ -7,7 +7,6 @@ package errorstest
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -25,7 +24,7 @@ func check(t *testing.T, file string) {
 	t.Run(file, func(t *testing.T) {
 		t.Parallel()
 
-		contents, err := ioutil.ReadFile(path(file))
+		contents, err := os.ReadFile(path(file))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -56,7 +55,7 @@ func check(t *testing.T, file string) {
 }
 
 func expect(t *testing.T, file string, errors []*regexp.Regexp) {
-	dir, err := ioutil.TempDir("", filepath.Base(t.Name()))
+	dir, err := os.MkdirTemp("", filepath.Base(t.Name()))
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/misc/cgo/errors/ptr_test.go b/misc/cgo/errors/ptr_test.go
index 4a46b6023bb510..0f39dc8e547ed0 100644
--- a/misc/cgo/errors/ptr_test.go
+++ b/misc/cgo/errors/ptr_test.go
@@ -10,7 +10,6 @@ import (
 	"bytes"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -463,7 +462,7 @@ func buildPtrTests(t *testing.T) (dir, exe string) {
 		gopath = *tmp
 		dir = ""
 	} else {
-		d, err := ioutil.TempDir("", filepath.Base(t.Name()))
+		d, err := os.MkdirTemp("", filepath.Base(t.Name()))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -475,7 +474,7 @@ func buildPtrTests(t *testing.T) (dir, exe string) {
 	if err := os.MkdirAll(src, 0777); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(src, "go.mod"), []byte("module ptrtest"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(src, "go.mod"), []byte("module ptrtest"), 0666); err != nil {
 		t.Fatal(err)
 	}
 
@@ -535,10 +534,10 @@ func buildPtrTests(t *testing.T) (dir, exe string) {
 	fmt.Fprintf(&cgo1, "}\n\n")
 	fmt.Fprintf(&cgo1, "%s\n", ptrTestMain)
 
-	if err := ioutil.WriteFile(filepath.Join(src, "cgo1.go"), cgo1.Bytes(), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(src, "cgo1.go"), cgo1.Bytes(), 0666); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(src, "cgo2.go"), cgo2.Bytes(), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(src, "cgo2.go"), cgo2.Bytes(), 0666); err != nil {
 		t.Fatal(err)
 	}
 
diff --git a/misc/cgo/life/life_test.go b/misc/cgo/life/life_test.go
index 3c95d87d8ade05..0becb262b43e9a 100644
--- a/misc/cgo/life/life_test.go
+++ b/misc/cgo/life/life_test.go
@@ -6,7 +6,6 @@ package life_test
 
 import (
 	"bytes"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -21,7 +20,7 @@ func TestMain(m *testing.M) {
 }
 
 func testMain(m *testing.M) int {
-	GOPATH, err := ioutil.TempDir("", "cgolife")
+	GOPATH, err := os.MkdirTemp("", "cgolife")
 	if err != nil {
 		log.Panic(err)
 	}
@@ -38,7 +37,7 @@ func testMain(m *testing.M) int {
 		log.Panic(err)
 	}
 	os.Setenv("PWD", modRoot)
-	if err := ioutil.WriteFile("go.mod", []byte("module cgolife\n"), 0666); err != nil {
+	if err := os.WriteFile("go.mod", []byte("module cgolife\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
diff --git a/misc/cgo/stdio/stdio_test.go b/misc/cgo/stdio/stdio_test.go
index ab5d328f676cd5..675418f98d026e 100644
--- a/misc/cgo/stdio/stdio_test.go
+++ b/misc/cgo/stdio/stdio_test.go
@@ -6,7 +6,6 @@ package stdio_test
 
 import (
 	"bytes"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -21,7 +20,7 @@ func TestMain(m *testing.M) {
 }
 
 func testMain(m *testing.M) int {
-	GOPATH, err := ioutil.TempDir("", "cgostdio")
+	GOPATH, err := os.MkdirTemp("", "cgostdio")
 	if err != nil {
 		log.Panic(err)
 	}
@@ -38,7 +37,7 @@ func testMain(m *testing.M) int {
 		log.Panic(err)
 	}
 	os.Setenv("PWD", modRoot)
-	if err := ioutil.WriteFile("go.mod", []byte("module cgostdio\n"), 0666); err != nil {
+	if err := os.WriteFile("go.mod", []byte("module cgostdio\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
diff --git a/misc/cgo/test/issue1435.go b/misc/cgo/test/issue1435.go
index a1c7cacde73844..cf34ce8db6ccb0 100644
--- a/misc/cgo/test/issue1435.go
+++ b/misc/cgo/test/issue1435.go
@@ -8,7 +8,7 @@ package cgotest
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"strings"
 	"syscall"
 	"testing"
@@ -64,7 +64,7 @@ import "C"
 func compareStatus(filter, expect string) error {
 	expected := filter + expect
 	pid := syscall.Getpid()
-	fs, err := ioutil.ReadDir(fmt.Sprintf("/proc/%d/task", pid))
+	fs, err := os.ReadDir(fmt.Sprintf("/proc/%d/task", pid))
 	if err != nil {
 		return fmt.Errorf("unable to find %d tasks: %v", pid, err)
 	}
@@ -72,7 +72,7 @@ func compareStatus(filter, expect string) error {
 	foundAThread := false
 	for _, f := range fs {
 		tf := fmt.Sprintf("/proc/%s/status", f.Name())
-		d, err := ioutil.ReadFile(tf)
+		d, err := os.ReadFile(tf)
 		if err != nil {
 			// There are a surprising number of ways this
 			// can error out on linux.  We've seen all of
diff --git a/misc/cgo/test/pkg_test.go b/misc/cgo/test/pkg_test.go
index 94abaa03e8d4b9..14013a4cd962b6 100644
--- a/misc/cgo/test/pkg_test.go
+++ b/misc/cgo/test/pkg_test.go
@@ -5,7 +5,6 @@
 package cgotest
 
 import (
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -37,7 +36,7 @@ func TestCrossPackageTests(t *testing.T) {
 		}
 	}
 
-	GOPATH, err := ioutil.TempDir("", "cgotest")
+	GOPATH, err := os.MkdirTemp("", "cgotest")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -47,7 +46,7 @@ func TestCrossPackageTests(t *testing.T) {
 	if err := overlayDir(modRoot, "testdata"); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgotest\n"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgotest\n"), 0666); err != nil {
 		t.Fatal(err)
 	}
 
diff --git a/misc/cgo/testcarchive/carchive_test.go b/misc/cgo/testcarchive/carchive_test.go
index 6a5adf79ca05bb..ec717c4f8b2c53 100644
--- a/misc/cgo/testcarchive/carchive_test.go
+++ b/misc/cgo/testcarchive/carchive_test.go
@@ -10,7 +10,6 @@ import (
 	"debug/elf"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -53,7 +52,7 @@ func testMain(m *testing.M) int {
 	// We need a writable GOPATH in which to run the tests.
 	// Construct one in a temporary directory.
 	var err error
-	GOPATH, err = ioutil.TempDir("", "carchive_test")
+	GOPATH, err = os.MkdirTemp("", "carchive_test")
 	if err != nil {
 		log.Panic(err)
 	}
@@ -74,7 +73,7 @@ func testMain(m *testing.M) int {
 		log.Panic(err)
 	}
 	os.Setenv("PWD", modRoot)
-	if err := ioutil.WriteFile("go.mod", []byte("module testcarchive\n"), 0666); err != nil {
+	if err := os.WriteFile("go.mod", []byte("module testcarchive\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
@@ -176,7 +175,7 @@ func genHeader(t *testing.T, header, dir string) {
 	// The 'cgo' command generates a number of additional artifacts,
 	// but we're only interested in the header.
 	// Shunt the rest of the outputs to a temporary directory.
-	objDir, err := ioutil.TempDir(GOPATH, "_obj")
+	objDir, err := os.MkdirTemp(GOPATH, "_obj")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -252,7 +251,7 @@ var badLineRegexp = regexp.MustCompile(`(?m)^#line [0-9]+ "/.*$`)
 // the user and make the files change based on details of the location
 // of GOPATH.
 func checkLineComments(t *testing.T, hdrname string) {
-	hdr, err := ioutil.ReadFile(hdrname)
+	hdr, err := os.ReadFile(hdrname)
 	if err != nil {
 		if !os.IsNotExist(err) {
 			t.Error(err)
@@ -618,7 +617,7 @@ func TestExtar(t *testing.T) {
 		t.Fatal(err)
 	}
 	s := strings.Replace(testar, "PWD", dir, 1)
-	if err := ioutil.WriteFile("testar", []byte(s), 0777); err != nil {
+	if err := os.WriteFile("testar", []byte(s), 0777); err != nil {
 		t.Fatal(err)
 	}
 
diff --git a/misc/cgo/testcshared/cshared_test.go b/misc/cgo/testcshared/cshared_test.go
index 3a4886cf30a88b..90d8c365e6d2ca 100644
--- a/misc/cgo/testcshared/cshared_test.go
+++ b/misc/cgo/testcshared/cshared_test.go
@@ -11,7 +11,6 @@ import (
 	"encoding/binary"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -125,7 +124,7 @@ func testMain(m *testing.M) int {
 	// Copy testdata into GOPATH/src/testcshared, along with a go.mod file
 	// declaring the same path.
 
-	GOPATH, err := ioutil.TempDir("", "cshared_test")
+	GOPATH, err := os.MkdirTemp("", "cshared_test")
 	if err != nil {
 		log.Panic(err)
 	}
@@ -140,7 +139,7 @@ func testMain(m *testing.M) int {
 		log.Panic(err)
 	}
 	os.Setenv("PWD", modRoot)
-	if err := ioutil.WriteFile("go.mod", []byte("module testcshared\n"), 0666); err != nil {
+	if err := os.WriteFile("go.mod", []byte("module testcshared\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
@@ -260,7 +259,7 @@ func createHeaders() error {
 	// The 'cgo' command generates a number of additional artifacts,
 	// but we're only interested in the header.
 	// Shunt the rest of the outputs to a temporary directory.
-	objDir, err := ioutil.TempDir("", "testcshared_obj")
+	objDir, err := os.MkdirTemp("", "testcshared_obj")
 	if err != nil {
 		return err
 	}
@@ -381,7 +380,7 @@ func main() {
 
 	srcfile := filepath.Join(tmpdir, "test.go")
 	objfile := filepath.Join(tmpdir, "test.dll")
-	if err := ioutil.WriteFile(srcfile, []byte(prog), 0666); err != nil {
+	if err := os.WriteFile(srcfile, []byte(prog), 0666); err != nil {
 		t.Fatal(err)
 	}
 	argv := []string{"build", "-buildmode=c-shared"}
@@ -643,7 +642,7 @@ func TestPIE(t *testing.T) {
 
 // Test that installing a second time recreates the header file.
 func TestCachedInstall(t *testing.T) {
-	tmpdir, err := ioutil.TempDir("", "cshared")
+	tmpdir, err := os.MkdirTemp("", "cshared")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -719,14 +718,14 @@ func TestCachedInstall(t *testing.T) {
 // copyFile copies src to dst.
 func copyFile(t *testing.T, dst, src string) {
 	t.Helper()
-	data, err := ioutil.ReadFile(src)
+	data, err := os.ReadFile(src)
 	if err != nil {
 		t.Fatal(err)
 	}
 	if err := os.MkdirAll(filepath.Dir(dst), 0777); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(dst, data, 0666); err != nil {
+	if err := os.WriteFile(dst, data, 0666); err != nil {
 		t.Fatal(err)
 	}
 }
@@ -743,7 +742,7 @@ func TestGo2C2Go(t *testing.T) {
 
 	t.Parallel()
 
-	tmpdir, err := ioutil.TempDir("", "cshared-TestGo2C2Go")
+	tmpdir, err := os.MkdirTemp("", "cshared-TestGo2C2Go")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/misc/cgo/testgodefs/testgodefs_test.go b/misc/cgo/testgodefs/testgodefs_test.go
index 4c2312c1c89633..aae34043605d34 100644
--- a/misc/cgo/testgodefs/testgodefs_test.go
+++ b/misc/cgo/testgodefs/testgodefs_test.go
@@ -6,7 +6,6 @@ package testgodefs
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -34,7 +33,7 @@ func TestGoDefs(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	gopath, err := ioutil.TempDir("", "testgodefs-gopath")
+	gopath, err := os.MkdirTemp("", "testgodefs-gopath")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -58,20 +57,20 @@ func TestGoDefs(t *testing.T) {
 			t.Fatalf("%s: %v\n%s", strings.Join(cmd.Args, " "), err, cmd.Stderr)
 		}
 
-		if err := ioutil.WriteFile(filepath.Join(dir, fp+"_defs.go"), out, 0644); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, fp+"_defs.go"), out, 0644); err != nil {
 			t.Fatal(err)
 		}
 	}
 
-	main, err := ioutil.ReadFile(filepath.Join("testdata", "main.go"))
+	main, err := os.ReadFile(filepath.Join("testdata", "main.go"))
 	if err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(dir, "main.go"), main, 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(dir, "main.go"), main, 0644); err != nil {
 		t.Fatal(err)
 	}
 
-	if err := ioutil.WriteFile(filepath.Join(dir, "go.mod"), []byte("module testgodefs\ngo 1.14\n"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module testgodefs\ngo 1.14\n"), 0644); err != nil {
 		t.Fatal(err)
 	}
 
diff --git a/misc/cgo/testplugin/plugin_test.go b/misc/cgo/testplugin/plugin_test.go
index 8869528015d86d..b894e8d30d0ca2 100644
--- a/misc/cgo/testplugin/plugin_test.go
+++ b/misc/cgo/testplugin/plugin_test.go
@@ -9,7 +9,6 @@ import (
 	"context"
 	"flag"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -35,7 +34,7 @@ func testMain(m *testing.M) int {
 	// Copy testdata into GOPATH/src/testplugin, along with a go.mod file
 	// declaring the same path.
 
-	GOPATH, err := ioutil.TempDir("", "plugin_test")
+	GOPATH, err := os.MkdirTemp("", "plugin_test")
 	if err != nil {
 		log.Panic(err)
 	}
@@ -50,7 +49,7 @@ func testMain(m *testing.M) int {
 		if err := overlayDir(dstRoot, srcRoot); err != nil {
 			log.Panic(err)
 		}
-		if err := ioutil.WriteFile(filepath.Join(dstRoot, "go.mod"), []byte("module testplugin\n"), 0666); err != nil {
+		if err := os.WriteFile(filepath.Join(dstRoot, "go.mod"), []byte("module testplugin\n"), 0666); err != nil {
 			log.Panic(err)
 		}
 	}
@@ -72,11 +71,11 @@ func testMain(m *testing.M) int {
 
 	goCmd(nil, "build", "-buildmode=plugin", "./plugin1")
 	goCmd(nil, "build", "-buildmode=plugin", "./plugin2")
-	so, err := ioutil.ReadFile("plugin2.so")
+	so, err := os.ReadFile("plugin2.so")
 	if err != nil {
 		log.Panic(err)
 	}
-	if err := ioutil.WriteFile("plugin2-dup.so", so, 0444); err != nil {
+	if err := os.WriteFile("plugin2-dup.so", so, 0444); err != nil {
 		log.Panic(err)
 	}
 
diff --git a/misc/cgo/testsanitizers/cc_test.go b/misc/cgo/testsanitizers/cc_test.go
index dab13364b862b4..384b6250e1ef16 100644
--- a/misc/cgo/testsanitizers/cc_test.go
+++ b/misc/cgo/testsanitizers/cc_test.go
@@ -11,7 +11,6 @@ import (
 	"encoding/json"
 	"errors"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -36,7 +35,7 @@ func requireOvercommit(t *testing.T) {
 
 	overcommit.Once.Do(func() {
 		var out []byte
-		out, overcommit.err = ioutil.ReadFile("/proc/sys/vm/overcommit_memory")
+		out, overcommit.err = os.ReadFile("/proc/sys/vm/overcommit_memory")
 		if overcommit.err != nil {
 			return
 		}
@@ -313,14 +312,14 @@ int main() {
 `)
 
 func (c *config) checkCSanitizer() (skip bool, err error) {
-	dir, err := ioutil.TempDir("", c.sanitizer)
+	dir, err := os.MkdirTemp("", c.sanitizer)
 	if err != nil {
 		return false, fmt.Errorf("failed to create temp directory: %v", err)
 	}
 	defer os.RemoveAll(dir)
 
 	src := filepath.Join(dir, "return0.c")
-	if err := ioutil.WriteFile(src, cMain, 0600); err != nil {
+	if err := os.WriteFile(src, cMain, 0600); err != nil {
 		return false, fmt.Errorf("failed to write C source file: %v", err)
 	}
 
@@ -418,7 +417,7 @@ func (d *tempDir) Join(name string) string {
 
 func newTempDir(t *testing.T) *tempDir {
 	t.Helper()
-	dir, err := ioutil.TempDir("", filepath.Dir(t.Name()))
+	dir, err := os.MkdirTemp("", filepath.Dir(t.Name()))
 	if err != nil {
 		t.Fatalf("Failed to create temp dir: %v", err)
 	}
diff --git a/misc/cgo/testsanitizers/cshared_test.go b/misc/cgo/testsanitizers/cshared_test.go
index b98360c4ae34d3..8fd03715a11bd8 100644
--- a/misc/cgo/testsanitizers/cshared_test.go
+++ b/misc/cgo/testsanitizers/cshared_test.go
@@ -6,7 +6,7 @@ package sanitizers_test
 
 import (
 	"fmt"
-	"io/ioutil"
+	"os"
 	"strings"
 	"testing"
 )
@@ -64,7 +64,7 @@ func TestShared(t *testing.T) {
 			mustRun(t, config.goCmd("build", "-buildmode=c-shared", "-o", lib, srcPath(tc.src)))
 
 			cSrc := dir.Join("main.c")
-			if err := ioutil.WriteFile(cSrc, cMain, 0600); err != nil {
+			if err := os.WriteFile(cSrc, cMain, 0600); err != nil {
 				t.Fatalf("failed to write C source file: %v", err)
 			}
 
diff --git a/misc/cgo/testshared/shared_test.go b/misc/cgo/testshared/shared_test.go
index f52391c6f6c6ab..e77f84891543f5 100644
--- a/misc/cgo/testshared/shared_test.go
+++ b/misc/cgo/testshared/shared_test.go
@@ -13,7 +13,6 @@ import (
 	"fmt"
 	"go/build"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -90,7 +89,7 @@ func goCmd(t *testing.T, args ...string) string {
 
 // TestMain calls testMain so that the latter can use defer (TestMain exits with os.Exit).
 func testMain(m *testing.M) (int, error) {
-	workDir, err := ioutil.TempDir("", "shared_test")
+	workDir, err := os.MkdirTemp("", "shared_test")
 	if err != nil {
 		return 0, err
 	}
@@ -177,7 +176,7 @@ func cloneTestdataModule(gopath string) (string, error) {
 	if err := overlayDir(modRoot, "testdata"); err != nil {
 		return "", err
 	}
-	if err := ioutil.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module testshared\n"), 0644); err != nil {
+	if err := os.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module testshared\n"), 0644); err != nil {
 		return "", err
 	}
 	return modRoot, nil
@@ -318,7 +317,7 @@ func TestShlibnameFiles(t *testing.T) {
 	}
 	for _, pkg := range pkgs {
 		shlibnamefile := filepath.Join(gorootInstallDir, pkg+".shlibname")
-		contentsb, err := ioutil.ReadFile(shlibnamefile)
+		contentsb, err := os.ReadFile(shlibnamefile)
 		if err != nil {
 			t.Errorf("error reading shlibnamefile for %s: %v", pkg, err)
 			continue
@@ -791,7 +790,7 @@ func resetFileStamps() {
 // It also sets the time of the file, so that we can see if it is rewritten.
 func touch(t *testing.T, path string) (cleanup func()) {
 	t.Helper()
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -837,14 +836,14 @@ func touch(t *testing.T, path string) (cleanup func()) {
 	// user-writable.
 	perm := fi.Mode().Perm() | 0200
 
-	if err := ioutil.WriteFile(path, data, perm); err != nil {
+	if err := os.WriteFile(path, data, perm); err != nil {
 		t.Fatal(err)
 	}
 	if err := os.Chtimes(path, nearlyNew, nearlyNew); err != nil {
 		t.Fatal(err)
 	}
 	return func() {
-		if err := ioutil.WriteFile(path, old, perm); err != nil {
+		if err := os.WriteFile(path, old, perm); err != nil {
 			t.Fatal(err)
 		}
 	}
diff --git a/misc/cgo/testso/so_test.go b/misc/cgo/testso/so_test.go
index 57f0fd34f78aca..1c97ae9bcb2562 100644
--- a/misc/cgo/testso/so_test.go
+++ b/misc/cgo/testso/so_test.go
@@ -7,7 +7,6 @@
 package so_test
 
 import (
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -37,7 +36,7 @@ func requireTestSOSupported(t *testing.T) {
 func TestSO(t *testing.T) {
 	requireTestSOSupported(t)
 
-	GOPATH, err := ioutil.TempDir("", "cgosotest")
+	GOPATH, err := os.MkdirTemp("", "cgosotest")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -47,7 +46,7 @@ func TestSO(t *testing.T) {
 	if err := overlayDir(modRoot, "testdata"); err != nil {
 		log.Panic(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgosotest\n"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgosotest\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
diff --git a/misc/cgo/testsovar/so_test.go b/misc/cgo/testsovar/so_test.go
index 57f0fd34f78aca..1c97ae9bcb2562 100644
--- a/misc/cgo/testsovar/so_test.go
+++ b/misc/cgo/testsovar/so_test.go
@@ -7,7 +7,6 @@
 package so_test
 
 import (
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -37,7 +36,7 @@ func requireTestSOSupported(t *testing.T) {
 func TestSO(t *testing.T) {
 	requireTestSOSupported(t)
 
-	GOPATH, err := ioutil.TempDir("", "cgosotest")
+	GOPATH, err := os.MkdirTemp("", "cgosotest")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -47,7 +46,7 @@ func TestSO(t *testing.T) {
 	if err := overlayDir(modRoot, "testdata"); err != nil {
 		log.Panic(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgosotest\n"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(modRoot, "go.mod"), []byte("module cgosotest\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
diff --git a/misc/ios/detect.go b/misc/ios/detect.go
index d32bcc3202a443..cde57238923be6 100644
--- a/misc/ios/detect.go
+++ b/misc/ios/detect.go
@@ -16,7 +16,6 @@ import (
 	"bytes"
 	"crypto/x509"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"strings"
@@ -38,7 +37,7 @@ func main() {
 	fmt.Println("# will be overwritten when running Go programs.")
 	for _, mp := range mps {
 		fmt.Println()
-		f, err := ioutil.TempFile("", "go_ios_detect_")
+		f, err := os.CreateTemp("", "go_ios_detect_")
 		check(err)
 		fname := f.Name()
 		defer os.Remove(fname)
diff --git a/misc/ios/go_ios_exec.go b/misc/ios/go_ios_exec.go
index 0acf1b259c0451..9e63717d9214d6 100644
--- a/misc/ios/go_ios_exec.go
+++ b/misc/ios/go_ios_exec.go
@@ -26,7 +26,6 @@ import (
 	"fmt"
 	"go/build"
 	"io"
-	"io/ioutil"
 	"log"
 	"net"
 	"os"
@@ -79,7 +78,7 @@ func main() {
 
 func runMain() (int, error) {
 	var err error
-	tmpdir, err = ioutil.TempDir("", "go_ios_exec_")
+	tmpdir, err = os.MkdirTemp("", "go_ios_exec_")
 	if err != nil {
 		return 1, err
 	}
@@ -205,13 +204,13 @@ func assembleApp(appdir, bin string) error {
 	}
 
 	entitlementsPath := filepath.Join(tmpdir, "Entitlements.plist")
-	if err := ioutil.WriteFile(entitlementsPath, []byte(entitlementsPlist()), 0744); err != nil {
+	if err := os.WriteFile(entitlementsPath, []byte(entitlementsPlist()), 0744); err != nil {
 		return err
 	}
-	if err := ioutil.WriteFile(filepath.Join(appdir, "Info.plist"), []byte(infoPlist(pkgpath)), 0744); err != nil {
+	if err := os.WriteFile(filepath.Join(appdir, "Info.plist"), []byte(infoPlist(pkgpath)), 0744); err != nil {
 		return err
 	}
-	if err := ioutil.WriteFile(filepath.Join(appdir, "ResourceRules.plist"), []byte(resourceRules), 0744); err != nil {
+	if err := os.WriteFile(filepath.Join(appdir, "ResourceRules.plist"), []byte(resourceRules), 0744); err != nil {
 		return err
 	}
 	return nil
diff --git a/misc/reboot/experiment_toolid_test.go b/misc/reboot/experiment_toolid_test.go
index eabf06b19ee3af..4f40284d80f107 100644
--- a/misc/reboot/experiment_toolid_test.go
+++ b/misc/reboot/experiment_toolid_test.go
@@ -13,7 +13,6 @@ package reboot_test
 
 import (
 	"bytes"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -23,7 +22,7 @@ import (
 
 func TestExperimentToolID(t *testing.T) {
 	// Set up GOROOT
-	goroot, err := ioutil.TempDir("", "experiment-goroot")
+	goroot, err := os.MkdirTemp("", "experiment-goroot")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -34,13 +33,13 @@ func TestExperimentToolID(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := ioutil.WriteFile(filepath.Join(goroot, "VERSION"), []byte("go1.999"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(goroot, "VERSION"), []byte("go1.999"), 0666); err != nil {
 		t.Fatal(err)
 	}
 	env := append(os.Environ(), "GOROOT=", "GOROOT_BOOTSTRAP="+runtime.GOROOT())
 
 	// Use a clean cache.
-	gocache, err := ioutil.TempDir("", "experiment-gocache")
+	gocache, err := os.MkdirTemp("", "experiment-gocache")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/misc/reboot/reboot_test.go b/misc/reboot/reboot_test.go
index 717c0fb709638c..6bafc608b5e234 100644
--- a/misc/reboot/reboot_test.go
+++ b/misc/reboot/reboot_test.go
@@ -7,7 +7,6 @@
 package reboot_test
 
 import (
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -16,7 +15,7 @@ import (
 )
 
 func TestRepeatBootstrap(t *testing.T) {
-	goroot, err := ioutil.TempDir("", "reboot-goroot")
+	goroot, err := os.MkdirTemp("", "reboot-goroot")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -27,7 +26,7 @@ func TestRepeatBootstrap(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	if err := ioutil.WriteFile(filepath.Join(goroot, "VERSION"), []byte(runtime.Version()), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(goroot, "VERSION"), []byte(runtime.Version()), 0666); err != nil {
 		t.Fatal(err)
 	}
 
diff --git a/src/go/build/build.go b/src/go/build/build.go
index 0732f6aa1991d9..501ce2e8dd2703 100644
--- a/src/go/build/build.go
+++ b/src/go/build/build.go
@@ -188,6 +188,7 @@ func (ctxt *Context) readDir(path string) ([]fs.FileInfo, error) {
 	if f := ctxt.ReadDir; f != nil {
 		return f(path)
 	}
+	// TODO: use os.ReadDir
 	return ioutil.ReadDir(path)
 }
 
diff --git a/src/go/types/check_test.go b/src/go/types/check_test.go
index 9812b3808b9190..327fb4c5f19cbe 100644
--- a/src/go/types/check_test.go
+++ b/src/go/types/check_test.go
@@ -34,7 +34,6 @@ import (
 	"go/scanner"
 	"go/token"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -332,7 +331,7 @@ func testDir(t *testing.T, dir string) {
 		// if fi is a directory, its files make up a single package
 		var filenames []string
 		if fi.IsDir() {
-			fis, err := ioutil.ReadDir(path)
+			fis, err := os.ReadDir(path)
 			if err != nil {
 				t.Error(err)
 				continue
diff --git a/src/internal/execabs/execabs_test.go b/src/internal/execabs/execabs_test.go
index b71458587c5e84..7609b2106a6254 100644
--- a/src/internal/execabs/execabs_test.go
+++ b/src/internal/execabs/execabs_test.go
@@ -8,7 +8,6 @@ import (
 	"context"
 	"fmt"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -42,7 +41,7 @@ func TestCommand(t *testing.T) {
 		if runtime.GOOS == "windows" {
 			executable += ".exe"
 		}
-		if err := ioutil.WriteFile(filepath.Join(tmpDir, executable), []byte{1, 2, 3}, 0111); err != nil {
+		if err := os.WriteFile(filepath.Join(tmpDir, executable), []byte{1, 2, 3}, 0111); err != nil {
 			t.Fatalf("ioutil.WriteFile failed: %s", err)
 		}
 		cwd, err := os.Getwd()
@@ -77,7 +76,7 @@ func TestLookPath(t *testing.T) {
 	if runtime.GOOS == "windows" {
 		executable += ".exe"
 	}
-	if err := ioutil.WriteFile(filepath.Join(tmpDir, executable), []byte{1, 2, 3}, 0111); err != nil {
+	if err := os.WriteFile(filepath.Join(tmpDir, executable), []byte{1, 2, 3}, 0111); err != nil {
 		t.Fatalf("ioutil.WriteFile failed: %s", err)
 	}
 	cwd, err := os.Getwd()
diff --git a/src/syscall/exec_windows_test.go b/src/syscall/exec_windows_test.go
index fb2c767c3515b6..a5b1fb42534168 100644
--- a/src/syscall/exec_windows_test.go
+++ b/src/syscall/exec_windows_test.go
@@ -6,7 +6,6 @@ package syscall_test
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -106,7 +105,7 @@ func TestChangingProcessParent(t *testing.T) {
 	if err != nil {
 		t.Errorf("child failed: %v: %v", err, string(childOutput))
 	}
-	childOutput, err = ioutil.ReadFile(childDumpPath)
+	childOutput, err = os.ReadFile(childDumpPath)
 	if err != nil {
 		t.Fatalf("reading child output failed: %v", err)
 	}
diff --git a/test/const7.go b/test/const7.go
index 9ffd678fc5d882..e75cebf23dbbed 100644
--- a/test/const7.go
+++ b/test/const7.go
@@ -11,7 +11,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -63,7 +62,7 @@ func main() {
 		return
 	}
 
-	dir, err := ioutil.TempDir("", "const7_")
+	dir, err := os.MkdirTemp("", "const7_")
 	if err != nil {
 		log.Fatalf("creating temp dir: %v\n", err)
 	}
diff --git a/test/fixedbugs/bug302.go b/test/fixedbugs/bug302.go
index a2ab661277a38f..344697fd7131dd 100644
--- a/test/fixedbugs/bug302.go
+++ b/test/fixedbugs/bug302.go
@@ -9,7 +9,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -20,7 +19,7 @@ var tmpDir string
 func main() {
 	fb, err := filepath.Abs("fixedbugs")
 	if err == nil {
-		tmpDir, err = ioutil.TempDir("", "bug302")
+		tmpDir, err = os.MkdirTemp("", "bug302")
 	}
 	if err != nil {
 		fmt.Println(err)
diff --git a/test/fixedbugs/bug369.go b/test/fixedbugs/bug369.go
index 83f638d04632af..5fe71b8006eff7 100644
--- a/test/fixedbugs/bug369.go
+++ b/test/fixedbugs/bug369.go
@@ -11,7 +11,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -21,7 +20,7 @@ func main() {
 	err := os.Chdir(filepath.Join(".", "fixedbugs", "bug369.dir"))
 	check(err)
 
-	tmpDir, err := ioutil.TempDir("", "bug369")
+	tmpDir, err := os.MkdirTemp("", "bug369")
 	check(err)
 	defer os.RemoveAll(tmpDir)
 
diff --git a/test/fixedbugs/issue11771.go b/test/fixedbugs/issue11771.go
index c95dd6ba396584..74c601142d814d 100644
--- a/test/fixedbugs/issue11771.go
+++ b/test/fixedbugs/issue11771.go
@@ -12,7 +12,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -25,7 +24,7 @@ func main() {
 		return
 	}
 
-	dir, err := ioutil.TempDir("", "go-issue11771")
+	dir, err := os.MkdirTemp("", "go-issue11771")
 	if err != nil {
 		log.Fatalf("creating temp dir: %v\n", err)
 	}
@@ -48,7 +47,7 @@ func x() {
 }
 `)
 
-	if err := ioutil.WriteFile(filepath.Join(dir, "x.go"), buf.Bytes(), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(dir, "x.go"), buf.Bytes(), 0666); err != nil {
 		log.Fatal(err)
 	}
 
diff --git a/test/fixedbugs/issue13268.go b/test/fixedbugs/issue13268.go
index 53a82d5074ab97..452bfc83b5aee7 100644
--- a/test/fixedbugs/issue13268.go
+++ b/test/fixedbugs/issue13268.go
@@ -14,7 +14,6 @@
 package main
 
 import (
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -23,7 +22,7 @@ import (
 
 func main() {
 	// create source
-	f, err := ioutil.TempFile("", "issue13268-")
+	f, err := os.CreateTemp("", "issue13268-")
 	if err != nil {
 		log.Fatalf("could not create source file: %v", err)
 	}
diff --git a/test/fixedbugs/issue16037_run.go b/test/fixedbugs/issue16037_run.go
index 68104a9000795d..0bd0d526e295a5 100644
--- a/test/fixedbugs/issue16037_run.go
+++ b/test/fixedbugs/issue16037_run.go
@@ -11,7 +11,6 @@ import (
 	"bytes"
 	"fmt"
 	"html/template"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -53,13 +52,13 @@ func main() {
 		log.Fatal(err)
 	}
 
-	dir, err := ioutil.TempDir("", "issue16037-")
+	dir, err := os.MkdirTemp("", "issue16037-")
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer os.RemoveAll(dir)
 	path := filepath.Join(dir, "ridiculous_number_of_fields.go")
-	if err := ioutil.WriteFile(path, buf.Bytes(), 0664); err != nil {
+	if err := os.WriteFile(path, buf.Bytes(), 0664); err != nil {
 		log.Fatal(err)
 	}
 
diff --git a/test/fixedbugs/issue19658.go b/test/fixedbugs/issue19658.go
index bab409c6c03cc8..b6b5c09461879a 100644
--- a/test/fixedbugs/issue19658.go
+++ b/test/fixedbugs/issue19658.go
@@ -11,7 +11,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -35,7 +34,7 @@ func main() {
 `
 
 func main() {
-	tempDir, err := ioutil.TempDir("", "")
+	tempDir, err := os.MkdirTemp("", "")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -70,7 +69,7 @@ func main() {
 		b := bytes.Buffer{}
 		fmt.Fprintf(&b, fn, tc.Type, tc.Input)
 
-		err = ioutil.WriteFile(tmpFile, b.Bytes(), 0644)
+		err = os.WriteFile(tmpFile, b.Bytes(), 0644)
 		if err != nil {
 			log.Fatal(err)
 		}
diff --git a/test/fixedbugs/issue21317.go b/test/fixedbugs/issue21317.go
index 32b660c1639169..2c634a7074730f 100644
--- a/test/fixedbugs/issue21317.go
+++ b/test/fixedbugs/issue21317.go
@@ -13,7 +13,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -21,7 +20,7 @@ import (
 )
 
 func main() {
-	f, err := ioutil.TempFile("", "issue21317.go")
+	f, err := os.CreateTemp("", "issue21317.go")
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/test/fixedbugs/issue21576.go b/test/fixedbugs/issue21576.go
index 3f9b1ba008af4c..f7b3d46711d744 100644
--- a/test/fixedbugs/issue21576.go
+++ b/test/fixedbugs/issue21576.go
@@ -14,7 +14,6 @@ package main
 import (
 	"bytes"
 	"context"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -34,14 +33,14 @@ func main() {
 `
 
 func main() {
-	dir, err := ioutil.TempDir("", "21576")
+	dir, err := os.MkdirTemp("", "21576")
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer os.RemoveAll(dir)
 
 	file := filepath.Join(dir, "main.go")
-	if err := ioutil.WriteFile(file, []byte(prog), 0655); err != nil {
+	if err := os.WriteFile(file, []byte(prog), 0655); err != nil {
 		log.Fatalf("Write error %v", err)
 	}
 
diff --git a/test/fixedbugs/issue22660.go b/test/fixedbugs/issue22660.go
index 9ce9c4d732e6d4..78773cb0a3d369 100644
--- a/test/fixedbugs/issue22660.go
+++ b/test/fixedbugs/issue22660.go
@@ -10,7 +10,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -19,7 +18,7 @@ import (
 )
 
 func main() {
-	f, err := ioutil.TempFile("", "issue22660.go")
+	f, err := os.CreateTemp("", "issue22660.go")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -31,7 +30,7 @@ func main() {
 	var src bytes.Buffer
 	fmt.Fprintf(&src, "//line %s:1\n", filepath.Join(path, "foo.go"))
 
-	if err := ioutil.WriteFile(f.Name(), src.Bytes(), 0660); err != nil {
+	if err := os.WriteFile(f.Name(), src.Bytes(), 0660); err != nil {
 		log.Fatal(err)
 	}
 
diff --git a/test/fixedbugs/issue22662b.go b/test/fixedbugs/issue22662b.go
index 8da17679be08e9..05cd2b9d5e025f 100644
--- a/test/fixedbugs/issue22662b.go
+++ b/test/fixedbugs/issue22662b.go
@@ -10,7 +10,6 @@
 package main
 
 import (
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -36,7 +35,7 @@ var tests = []struct {
 }
 
 func main() {
-	f, err := ioutil.TempFile("", "issue22662b.go")
+	f, err := os.CreateTemp("", "issue22662b.go")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -44,7 +43,7 @@ func main() {
 	defer os.Remove(f.Name())
 
 	for _, test := range tests {
-		if err := ioutil.WriteFile(f.Name(), []byte(test.src), 0660); err != nil {
+		if err := os.WriteFile(f.Name(), []byte(test.src), 0660); err != nil {
 			log.Fatal(err)
 		}
 
diff --git a/test/fixedbugs/issue26411.go b/test/fixedbugs/issue26411.go
index 5f40bf25229a1a..36850ac4df83e2 100644
--- a/test/fixedbugs/issue26411.go
+++ b/test/fixedbugs/issue26411.go
@@ -14,7 +14,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -23,7 +22,7 @@ import (
 )
 
 func main() {
-	tmpdir, err := ioutil.TempDir("", "issue26411")
+	tmpdir, err := os.MkdirTemp("", "issue26411")
 	if err != nil {
 		log.Fatalf("Failed to create temporary directory: %v", err)
 	}
@@ -71,7 +70,7 @@ bar            :
 
 	for i, test := range tests {
 		filename := filepath.Join(tmpdir, fmt.Sprintf("%d.go", i))
-		if err := ioutil.WriteFile(filename, []byte(test.code), 0644); err != nil {
+		if err := os.WriteFile(filename, []byte(test.code), 0644); err != nil {
 			log.Printf("#%d: failed to create file %s", i, filename)
 			continue
 		}
diff --git a/test/fixedbugs/issue30908.dir/b.go b/test/fixedbugs/issue30908.dir/b.go
index 2f543985b4fc39..e6f1450df83caa 100644
--- a/test/fixedbugs/issue30908.dir/b.go
+++ b/test/fixedbugs/issue30908.dir/b.go
@@ -5,7 +5,7 @@
 package b
 
 import (
-	"io/ioutil"
+	"os"
 
 	"./a"
 )
@@ -27,7 +27,7 @@ func ReadValues(data []byte) (vals map[string]interface{}, err error) {
 // of the output param.
 func CallReadValues(filename string) (map[string]interface{}, error) {
 	defer func() { G++ }()
-	data, err := ioutil.ReadFile(filename)
+	data, err := os.ReadFile(filename)
 	if err != nil {
 		return map[string]interface{}{}, err
 	}
diff --git a/test/fixedbugs/issue33555.go b/test/fixedbugs/issue33555.go
index c1fcd2a79b387a..560dbdff8a9955 100644
--- a/test/fixedbugs/issue33555.go
+++ b/test/fixedbugs/issue33555.go
@@ -11,7 +11,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -56,14 +55,14 @@ func test() error {
 	}
 	fmt.Fprintf(&buf, fnlast, count)
 
-	dir, err := ioutil.TempDir("", "issue33555")
+	dir, err := os.MkdirTemp("", "issue33555")
 	if err != nil {
 		return err
 	}
 	defer os.RemoveAll(dir)
 
 	fn := filepath.Join(dir, "x.go")
-	if err := ioutil.WriteFile(fn, buf.Bytes(), 0644); err != nil {
+	if err := os.WriteFile(fn, buf.Bytes(), 0644); err != nil {
 		return err
 	}
 
diff --git a/test/fixedbugs/issue36437.go b/test/fixedbugs/issue36437.go
index c7a11d27a89349..01099b7a60318a 100644
--- a/test/fixedbugs/issue36437.go
+++ b/test/fixedbugs/issue36437.go
@@ -18,14 +18,13 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"regexp"
 )
 
 func main() {
-	tmpDir, err := ioutil.TempDir("", "issue36437")
+	tmpDir, err := os.MkdirTemp("", "issue36437")
 	if err != nil {
 		panic(err)
 	}
diff --git a/test/fixedbugs/issue9355.go b/test/fixedbugs/issue9355.go
index 319a2a90df9ba2..bfd032f99d7631 100644
--- a/test/fixedbugs/issue9355.go
+++ b/test/fixedbugs/issue9355.go
@@ -9,7 +9,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -20,7 +19,7 @@ func main() {
 	err := os.Chdir(filepath.Join("fixedbugs", "issue9355.dir"))
 	check(err)
 
-	f, err := ioutil.TempFile("", "issue9355-*.o")
+	f, err := os.CreateTemp("", "issue9355-*.o")
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
diff --git a/test/linkmain_run.go b/test/linkmain_run.go
index 077f7ee91753c5..91156b69e160a5 100644
--- a/test/linkmain_run.go
+++ b/test/linkmain_run.go
@@ -11,7 +11,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -52,7 +51,7 @@ func runFail(cmdline ...string) {
 
 func main() {
 	var err error
-	tmpDir, err = ioutil.TempDir("", "")
+	tmpDir, err = os.MkdirTemp("", "")
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
diff --git a/test/linkobj.go b/test/linkobj.go
index 4c9bd24568b112..cdb09181db6131 100644
--- a/test/linkobj.go
+++ b/test/linkobj.go
@@ -11,7 +11,6 @@ package main
 
 import (
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -21,7 +20,7 @@ import (
 var pwd, tmpdir string
 
 func main() {
-	dir, err := ioutil.TempDir("", "go-test-linkobj-")
+	dir, err := os.MkdirTemp("", "go-test-linkobj-")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -122,18 +121,18 @@ func runFail(args ...string) string {
 }
 
 func cp(src, dst string) {
-	data, err := ioutil.ReadFile(src)
+	data, err := os.ReadFile(src)
 	if err != nil {
 		fatalf("%v", err)
 	}
-	err = ioutil.WriteFile(dst, data, 0666)
+	err = os.WriteFile(dst, data, 0666)
 	if err != nil {
 		fatalf("%v", err)
 	}
 }
 
 func writeFile(name, data string) {
-	err := ioutil.WriteFile(name, []byte(data), 0666)
+	err := os.WriteFile(name, []byte(data), 0666)
 	if err != nil {
 		fatalf("%v", err)
 	}
diff --git a/test/nosplit.go b/test/nosplit.go
index 7c7e1bfd99e01a..5b2503041b12b1 100644
--- a/test/nosplit.go
+++ b/test/nosplit.go
@@ -10,7 +10,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -201,7 +200,7 @@ func main() {
 		goarch = runtime.GOARCH
 	}
 
-	dir, err := ioutil.TempDir("", "go-test-nosplit")
+	dir, err := os.MkdirTemp("", "go-test-nosplit")
 	if err != nil {
 		bug()
 		fmt.Printf("creating temp dir: %v\n", err)
@@ -210,7 +209,7 @@ func main() {
 	defer os.RemoveAll(dir)
 	os.Setenv("GOPATH", filepath.Join(dir, "_gopath"))
 
-	if err := ioutil.WriteFile(filepath.Join(dir, "go.mod"), []byte("module go-test-nosplit\n"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module go-test-nosplit\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
@@ -351,10 +350,10 @@ TestCases:
 			fmt.Printf("-- asm.s --\n%s", buf.String())
 		}
 
-		if err := ioutil.WriteFile(filepath.Join(dir, "asm.s"), buf.Bytes(), 0666); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, "asm.s"), buf.Bytes(), 0666); err != nil {
 			log.Fatal(err)
 		}
-		if err := ioutil.WriteFile(filepath.Join(dir, "main.go"), gobuf.Bytes(), 0666); err != nil {
+		if err := os.WriteFile(filepath.Join(dir, "main.go"), gobuf.Bytes(), 0666); err != nil {
 			log.Fatal(err)
 		}
 
diff --git a/test/run.go b/test/run.go
index 7d5a558f2d2753..038908f0dd8b85 100644
--- a/test/run.go
+++ b/test/run.go
@@ -15,7 +15,6 @@ import (
 	"hash/fnv"
 	"io"
 	"io/fs"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -313,8 +312,8 @@ func (t *test) goDirName() string {
 	return filepath.Join(t.dir, strings.Replace(t.gofile, ".go", ".dir", -1))
 }
 
-func goDirFiles(longdir string) (filter []os.FileInfo, err error) {
-	files, dirErr := ioutil.ReadDir(longdir)
+func goDirFiles(longdir string) (filter []os.DirEntry, err error) {
+	files, dirErr := os.ReadDir(longdir)
 	if dirErr != nil {
 		return nil, dirErr
 	}
@@ -329,7 +328,7 @@ func goDirFiles(longdir string) (filter []os.FileInfo, err error) {
 var packageRE = regexp.MustCompile(`(?m)^package ([\p{Lu}\p{Ll}\w]+)`)
 
 func getPackageNameFromSource(fn string) (string, error) {
-	data, err := ioutil.ReadFile(fn)
+	data, err := os.ReadFile(fn)
 	if err != nil {
 		return "", err
 	}
@@ -477,7 +476,7 @@ func (t *test) run() {
 		close(t.donec)
 	}()
 
-	srcBytes, err := ioutil.ReadFile(t.goFileName())
+	srcBytes, err := os.ReadFile(t.goFileName())
 	if err != nil {
 		t.err = err
 		return
@@ -600,7 +599,7 @@ func (t *test) run() {
 		defer os.RemoveAll(t.tempDir)
 	}
 
-	err = ioutil.WriteFile(filepath.Join(t.tempDir, t.gofile), srcBytes, 0644)
+	err = os.WriteFile(filepath.Join(t.tempDir, t.gofile), srcBytes, 0644)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -957,7 +956,7 @@ func (t *test) run() {
 		}
 
 		modFile := fmt.Sprintf("module %s\ngo 1.14\n", modName)
-		if err := ioutil.WriteFile(filepath.Join(gopathSrcDir, "go.mod"), []byte(modFile), 0666); err != nil {
+		if err := os.WriteFile(filepath.Join(gopathSrcDir, "go.mod"), []byte(modFile), 0666); err != nil {
 			t.err = err
 			return
 		}
@@ -986,7 +985,7 @@ func (t *test) run() {
 		// Build an executable from all the .go and .s files in a subdirectory.
 		// Run it and verify its output in the buildrundir case.
 		longdir := filepath.Join(cwd, t.goDirName())
-		files, dirErr := ioutil.ReadDir(longdir)
+		files, dirErr := os.ReadDir(longdir)
 		if dirErr != nil {
 			t.err = dirErr
 			break
@@ -1004,7 +1003,7 @@ func (t *test) run() {
 		}
 		if len(asms) > 0 {
 			emptyHdrFile := filepath.Join(t.tempDir, "go_asm.h")
-			if err := ioutil.WriteFile(emptyHdrFile, nil, 0666); err != nil {
+			if err := os.WriteFile(emptyHdrFile, nil, 0666); err != nil {
 				t.err = fmt.Errorf("write empty go_asm.h: %s", err)
 				return
 			}
@@ -1148,7 +1147,7 @@ func (t *test) run() {
 			return
 		}
 		tfile := filepath.Join(t.tempDir, "tmp__.go")
-		if err := ioutil.WriteFile(tfile, out, 0666); err != nil {
+		if err := os.WriteFile(tfile, out, 0666); err != nil {
 			t.err = fmt.Errorf("write tempfile:%s", err)
 			return
 		}
@@ -1179,7 +1178,7 @@ func (t *test) run() {
 			return
 		}
 		tfile := filepath.Join(t.tempDir, "tmp__.go")
-		err = ioutil.WriteFile(tfile, out, 0666)
+		err = os.WriteFile(tfile, out, 0666)
 		if err != nil {
 			t.err = fmt.Errorf("write tempfile:%s", err)
 			return
@@ -1227,7 +1226,7 @@ func (t *test) String() string {
 
 func (t *test) makeTempDir() {
 	var err error
-	t.tempDir, err = ioutil.TempDir("", "")
+	t.tempDir, err = os.MkdirTemp("", "")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -1244,7 +1243,7 @@ func (t *test) checkExpectedOutput(gotBytes []byte) {
 	filename := filepath.Join(t.dir, t.gofile)
 	filename = filename[:len(filename)-len(".go")]
 	filename += ".out"
-	b, err := ioutil.ReadFile(filename)
+	b, err := os.ReadFile(filename)
 	// File is allowed to be missing (err != nil) in which case output should be empty.
 	got = strings.Replace(got, "\r\n", "\n", -1)
 	if got != string(b) {
@@ -1366,7 +1365,7 @@ func (t *test) errorCheck(outStr string, wantAuto bool, fullshort ...string) (er
 func (t *test) updateErrors(out, file string) {
 	base := path.Base(file)
 	// Read in source file.
-	src, err := ioutil.ReadFile(file)
+	src, err := os.ReadFile(file)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		return
@@ -1423,7 +1422,7 @@ func (t *test) updateErrors(out, file string) {
 		}
 	}
 	// Write new file.
-	err = ioutil.WriteFile(file, []byte(strings.Join(lines, "\n")), 0640)
+	err = os.WriteFile(file, []byte(strings.Join(lines, "\n")), 0640)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		return
@@ -1482,7 +1481,7 @@ var (
 func (t *test) wantedErrors(file, short string) (errs []wantedError) {
 	cache := make(map[string]*regexp.Regexp)
 
-	src, _ := ioutil.ReadFile(file)
+	src, _ := os.ReadFile(file)
 	for i, line := range strings.Split(string(src), "\n") {
 		lineNum := i + 1
 		if strings.Contains(line, "////") {
@@ -1625,7 +1624,7 @@ func (t *test) wantedAsmOpcodes(fn string) asmChecks {
 	ops := make(asmChecks)
 
 	comment := ""
-	src, _ := ioutil.ReadFile(fn)
+	src, _ := os.ReadFile(fn)
 	for i, line := range strings.Split(string(src), "\n") {
 		matches := rxAsmComment.FindStringSubmatch(line)
 		code, cmt := matches[1], matches[2]
diff --git a/test/sinit_run.go b/test/sinit_run.go
index dcaf3383312602..127c5abfcf164b 100644
--- a/test/sinit_run.go
+++ b/test/sinit_run.go
@@ -12,13 +12,12 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"os/exec"
 )
 
 func main() {
-	f, err := ioutil.TempFile("", "sinit-*.o")
+	f, err := os.CreateTemp("", "sinit-*.o")
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
diff --git a/test/winbatch.go b/test/winbatch.go
index 54c2fff13463bd..86a68ca1eaa695 100644
--- a/test/winbatch.go
+++ b/test/winbatch.go
@@ -12,7 +12,6 @@ package main
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -50,7 +49,7 @@ func main() {
 }
 
 func enforceBatchStrictCRLF(path string) {
-	b, err := ioutil.ReadFile(path)
+	b, err := os.ReadFile(path)
 	if err != nil {
 		log.Fatalln(err)
 	}

From dda42b09fff36dc08ec1cdec50cc19e3da5058e5 Mon Sep 17 00:00:00 2001
From: KimMachineGun <geon0250@gmail.com>
Date: Sat, 3 Apr 2021 17:08:09 +0900
Subject: [PATCH 4/4] test: revert changes in test directory

---
 test/const7.go                     |  3 ++-
 test/fixedbugs/bug302.go           |  3 ++-
 test/fixedbugs/bug369.go           |  3 ++-
 test/fixedbugs/issue11771.go       |  5 +++--
 test/fixedbugs/issue13268.go       |  3 ++-
 test/fixedbugs/issue16037_run.go   |  5 +++--
 test/fixedbugs/issue19658.go       |  5 +++--
 test/fixedbugs/issue21317.go       |  3 ++-
 test/fixedbugs/issue21576.go       |  5 +++--
 test/fixedbugs/issue22660.go       |  5 +++--
 test/fixedbugs/issue22662b.go      |  5 +++--
 test/fixedbugs/issue26411.go       |  5 +++--
 test/fixedbugs/issue30908.dir/b.go |  4 ++--
 test/fixedbugs/issue33555.go       |  5 +++--
 test/fixedbugs/issue36437.go       |  3 ++-
 test/fixedbugs/issue9355.go        |  3 ++-
 test/linkmain_run.go               |  3 ++-
 test/linkobj.go                    |  9 ++++----
 test/nosplit.go                    |  9 ++++----
 test/run.go                        | 33 +++++++++++++++---------------
 test/sinit_run.go                  |  3 ++-
 test/winbatch.go                   |  3 ++-
 22 files changed, 73 insertions(+), 52 deletions(-)

diff --git a/test/const7.go b/test/const7.go
index e75cebf23dbbed..9ffd678fc5d882 100644
--- a/test/const7.go
+++ b/test/const7.go
@@ -11,6 +11,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -62,7 +63,7 @@ func main() {
 		return
 	}
 
-	dir, err := os.MkdirTemp("", "const7_")
+	dir, err := ioutil.TempDir("", "const7_")
 	if err != nil {
 		log.Fatalf("creating temp dir: %v\n", err)
 	}
diff --git a/test/fixedbugs/bug302.go b/test/fixedbugs/bug302.go
index 344697fd7131dd..a2ab661277a38f 100644
--- a/test/fixedbugs/bug302.go
+++ b/test/fixedbugs/bug302.go
@@ -9,6 +9,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -19,7 +20,7 @@ var tmpDir string
 func main() {
 	fb, err := filepath.Abs("fixedbugs")
 	if err == nil {
-		tmpDir, err = os.MkdirTemp("", "bug302")
+		tmpDir, err = ioutil.TempDir("", "bug302")
 	}
 	if err != nil {
 		fmt.Println(err)
diff --git a/test/fixedbugs/bug369.go b/test/fixedbugs/bug369.go
index 5fe71b8006eff7..83f638d04632af 100644
--- a/test/fixedbugs/bug369.go
+++ b/test/fixedbugs/bug369.go
@@ -11,6 +11,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -20,7 +21,7 @@ func main() {
 	err := os.Chdir(filepath.Join(".", "fixedbugs", "bug369.dir"))
 	check(err)
 
-	tmpDir, err := os.MkdirTemp("", "bug369")
+	tmpDir, err := ioutil.TempDir("", "bug369")
 	check(err)
 	defer os.RemoveAll(tmpDir)
 
diff --git a/test/fixedbugs/issue11771.go b/test/fixedbugs/issue11771.go
index 74c601142d814d..c95dd6ba396584 100644
--- a/test/fixedbugs/issue11771.go
+++ b/test/fixedbugs/issue11771.go
@@ -12,6 +12,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -24,7 +25,7 @@ func main() {
 		return
 	}
 
-	dir, err := os.MkdirTemp("", "go-issue11771")
+	dir, err := ioutil.TempDir("", "go-issue11771")
 	if err != nil {
 		log.Fatalf("creating temp dir: %v\n", err)
 	}
@@ -47,7 +48,7 @@ func x() {
 }
 `)
 
-	if err := os.WriteFile(filepath.Join(dir, "x.go"), buf.Bytes(), 0666); err != nil {
+	if err := ioutil.WriteFile(filepath.Join(dir, "x.go"), buf.Bytes(), 0666); err != nil {
 		log.Fatal(err)
 	}
 
diff --git a/test/fixedbugs/issue13268.go b/test/fixedbugs/issue13268.go
index 452bfc83b5aee7..53a82d5074ab97 100644
--- a/test/fixedbugs/issue13268.go
+++ b/test/fixedbugs/issue13268.go
@@ -14,6 +14,7 @@
 package main
 
 import (
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -22,7 +23,7 @@ import (
 
 func main() {
 	// create source
-	f, err := os.CreateTemp("", "issue13268-")
+	f, err := ioutil.TempFile("", "issue13268-")
 	if err != nil {
 		log.Fatalf("could not create source file: %v", err)
 	}
diff --git a/test/fixedbugs/issue16037_run.go b/test/fixedbugs/issue16037_run.go
index 0bd0d526e295a5..68104a9000795d 100644
--- a/test/fixedbugs/issue16037_run.go
+++ b/test/fixedbugs/issue16037_run.go
@@ -11,6 +11,7 @@ import (
 	"bytes"
 	"fmt"
 	"html/template"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -52,13 +53,13 @@ func main() {
 		log.Fatal(err)
 	}
 
-	dir, err := os.MkdirTemp("", "issue16037-")
+	dir, err := ioutil.TempDir("", "issue16037-")
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer os.RemoveAll(dir)
 	path := filepath.Join(dir, "ridiculous_number_of_fields.go")
-	if err := os.WriteFile(path, buf.Bytes(), 0664); err != nil {
+	if err := ioutil.WriteFile(path, buf.Bytes(), 0664); err != nil {
 		log.Fatal(err)
 	}
 
diff --git a/test/fixedbugs/issue19658.go b/test/fixedbugs/issue19658.go
index b6b5c09461879a..bab409c6c03cc8 100644
--- a/test/fixedbugs/issue19658.go
+++ b/test/fixedbugs/issue19658.go
@@ -11,6 +11,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -34,7 +35,7 @@ func main() {
 `
 
 func main() {
-	tempDir, err := os.MkdirTemp("", "")
+	tempDir, err := ioutil.TempDir("", "")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -69,7 +70,7 @@ func main() {
 		b := bytes.Buffer{}
 		fmt.Fprintf(&b, fn, tc.Type, tc.Input)
 
-		err = os.WriteFile(tmpFile, b.Bytes(), 0644)
+		err = ioutil.WriteFile(tmpFile, b.Bytes(), 0644)
 		if err != nil {
 			log.Fatal(err)
 		}
diff --git a/test/fixedbugs/issue21317.go b/test/fixedbugs/issue21317.go
index 2c634a7074730f..32b660c1639169 100644
--- a/test/fixedbugs/issue21317.go
+++ b/test/fixedbugs/issue21317.go
@@ -13,6 +13,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -20,7 +21,7 @@ import (
 )
 
 func main() {
-	f, err := os.CreateTemp("", "issue21317.go")
+	f, err := ioutil.TempFile("", "issue21317.go")
 	if err != nil {
 		log.Fatal(err)
 	}
diff --git a/test/fixedbugs/issue21576.go b/test/fixedbugs/issue21576.go
index f7b3d46711d744..3f9b1ba008af4c 100644
--- a/test/fixedbugs/issue21576.go
+++ b/test/fixedbugs/issue21576.go
@@ -14,6 +14,7 @@ package main
 import (
 	"bytes"
 	"context"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -33,14 +34,14 @@ func main() {
 `
 
 func main() {
-	dir, err := os.MkdirTemp("", "21576")
+	dir, err := ioutil.TempDir("", "21576")
 	if err != nil {
 		log.Fatal(err)
 	}
 	defer os.RemoveAll(dir)
 
 	file := filepath.Join(dir, "main.go")
-	if err := os.WriteFile(file, []byte(prog), 0655); err != nil {
+	if err := ioutil.WriteFile(file, []byte(prog), 0655); err != nil {
 		log.Fatalf("Write error %v", err)
 	}
 
diff --git a/test/fixedbugs/issue22660.go b/test/fixedbugs/issue22660.go
index 78773cb0a3d369..9ce9c4d732e6d4 100644
--- a/test/fixedbugs/issue22660.go
+++ b/test/fixedbugs/issue22660.go
@@ -10,6 +10,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -18,7 +19,7 @@ import (
 )
 
 func main() {
-	f, err := os.CreateTemp("", "issue22660.go")
+	f, err := ioutil.TempFile("", "issue22660.go")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -30,7 +31,7 @@ func main() {
 	var src bytes.Buffer
 	fmt.Fprintf(&src, "//line %s:1\n", filepath.Join(path, "foo.go"))
 
-	if err := os.WriteFile(f.Name(), src.Bytes(), 0660); err != nil {
+	if err := ioutil.WriteFile(f.Name(), src.Bytes(), 0660); err != nil {
 		log.Fatal(err)
 	}
 
diff --git a/test/fixedbugs/issue22662b.go b/test/fixedbugs/issue22662b.go
index 05cd2b9d5e025f..8da17679be08e9 100644
--- a/test/fixedbugs/issue22662b.go
+++ b/test/fixedbugs/issue22662b.go
@@ -10,6 +10,7 @@
 package main
 
 import (
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -35,7 +36,7 @@ var tests = []struct {
 }
 
 func main() {
-	f, err := os.CreateTemp("", "issue22662b.go")
+	f, err := ioutil.TempFile("", "issue22662b.go")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -43,7 +44,7 @@ func main() {
 	defer os.Remove(f.Name())
 
 	for _, test := range tests {
-		if err := os.WriteFile(f.Name(), []byte(test.src), 0660); err != nil {
+		if err := ioutil.WriteFile(f.Name(), []byte(test.src), 0660); err != nil {
 			log.Fatal(err)
 		}
 
diff --git a/test/fixedbugs/issue26411.go b/test/fixedbugs/issue26411.go
index 36850ac4df83e2..5f40bf25229a1a 100644
--- a/test/fixedbugs/issue26411.go
+++ b/test/fixedbugs/issue26411.go
@@ -14,6 +14,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -22,7 +23,7 @@ import (
 )
 
 func main() {
-	tmpdir, err := os.MkdirTemp("", "issue26411")
+	tmpdir, err := ioutil.TempDir("", "issue26411")
 	if err != nil {
 		log.Fatalf("Failed to create temporary directory: %v", err)
 	}
@@ -70,7 +71,7 @@ bar            :
 
 	for i, test := range tests {
 		filename := filepath.Join(tmpdir, fmt.Sprintf("%d.go", i))
-		if err := os.WriteFile(filename, []byte(test.code), 0644); err != nil {
+		if err := ioutil.WriteFile(filename, []byte(test.code), 0644); err != nil {
 			log.Printf("#%d: failed to create file %s", i, filename)
 			continue
 		}
diff --git a/test/fixedbugs/issue30908.dir/b.go b/test/fixedbugs/issue30908.dir/b.go
index e6f1450df83caa..2f543985b4fc39 100644
--- a/test/fixedbugs/issue30908.dir/b.go
+++ b/test/fixedbugs/issue30908.dir/b.go
@@ -5,7 +5,7 @@
 package b
 
 import (
-	"os"
+	"io/ioutil"
 
 	"./a"
 )
@@ -27,7 +27,7 @@ func ReadValues(data []byte) (vals map[string]interface{}, err error) {
 // of the output param.
 func CallReadValues(filename string) (map[string]interface{}, error) {
 	defer func() { G++ }()
-	data, err := os.ReadFile(filename)
+	data, err := ioutil.ReadFile(filename)
 	if err != nil {
 		return map[string]interface{}{}, err
 	}
diff --git a/test/fixedbugs/issue33555.go b/test/fixedbugs/issue33555.go
index 560dbdff8a9955..c1fcd2a79b387a 100644
--- a/test/fixedbugs/issue33555.go
+++ b/test/fixedbugs/issue33555.go
@@ -11,6 +11,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -55,14 +56,14 @@ func test() error {
 	}
 	fmt.Fprintf(&buf, fnlast, count)
 
-	dir, err := os.MkdirTemp("", "issue33555")
+	dir, err := ioutil.TempDir("", "issue33555")
 	if err != nil {
 		return err
 	}
 	defer os.RemoveAll(dir)
 
 	fn := filepath.Join(dir, "x.go")
-	if err := os.WriteFile(fn, buf.Bytes(), 0644); err != nil {
+	if err := ioutil.WriteFile(fn, buf.Bytes(), 0644); err != nil {
 		return err
 	}
 
diff --git a/test/fixedbugs/issue36437.go b/test/fixedbugs/issue36437.go
index 01099b7a60318a..c7a11d27a89349 100644
--- a/test/fixedbugs/issue36437.go
+++ b/test/fixedbugs/issue36437.go
@@ -18,13 +18,14 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"regexp"
 )
 
 func main() {
-	tmpDir, err := os.MkdirTemp("", "issue36437")
+	tmpDir, err := ioutil.TempDir("", "issue36437")
 	if err != nil {
 		panic(err)
 	}
diff --git a/test/fixedbugs/issue9355.go b/test/fixedbugs/issue9355.go
index bfd032f99d7631..319a2a90df9ba2 100644
--- a/test/fixedbugs/issue9355.go
+++ b/test/fixedbugs/issue9355.go
@@ -9,6 +9,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -19,7 +20,7 @@ func main() {
 	err := os.Chdir(filepath.Join("fixedbugs", "issue9355.dir"))
 	check(err)
 
-	f, err := os.CreateTemp("", "issue9355-*.o")
+	f, err := ioutil.TempFile("", "issue9355-*.o")
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
diff --git a/test/linkmain_run.go b/test/linkmain_run.go
index 91156b69e160a5..077f7ee91753c5 100644
--- a/test/linkmain_run.go
+++ b/test/linkmain_run.go
@@ -11,6 +11,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -51,7 +52,7 @@ func runFail(cmdline ...string) {
 
 func main() {
 	var err error
-	tmpDir, err = os.MkdirTemp("", "")
+	tmpDir, err = ioutil.TempDir("", "")
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
diff --git a/test/linkobj.go b/test/linkobj.go
index cdb09181db6131..4c9bd24568b112 100644
--- a/test/linkobj.go
+++ b/test/linkobj.go
@@ -11,6 +11,7 @@ package main
 
 import (
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -20,7 +21,7 @@ import (
 var pwd, tmpdir string
 
 func main() {
-	dir, err := os.MkdirTemp("", "go-test-linkobj-")
+	dir, err := ioutil.TempDir("", "go-test-linkobj-")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -121,18 +122,18 @@ func runFail(args ...string) string {
 }
 
 func cp(src, dst string) {
-	data, err := os.ReadFile(src)
+	data, err := ioutil.ReadFile(src)
 	if err != nil {
 		fatalf("%v", err)
 	}
-	err = os.WriteFile(dst, data, 0666)
+	err = ioutil.WriteFile(dst, data, 0666)
 	if err != nil {
 		fatalf("%v", err)
 	}
 }
 
 func writeFile(name, data string) {
-	err := os.WriteFile(name, []byte(data), 0666)
+	err := ioutil.WriteFile(name, []byte(data), 0666)
 	if err != nil {
 		fatalf("%v", err)
 	}
diff --git a/test/nosplit.go b/test/nosplit.go
index 5b2503041b12b1..7c7e1bfd99e01a 100644
--- a/test/nosplit.go
+++ b/test/nosplit.go
@@ -10,6 +10,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -200,7 +201,7 @@ func main() {
 		goarch = runtime.GOARCH
 	}
 
-	dir, err := os.MkdirTemp("", "go-test-nosplit")
+	dir, err := ioutil.TempDir("", "go-test-nosplit")
 	if err != nil {
 		bug()
 		fmt.Printf("creating temp dir: %v\n", err)
@@ -209,7 +210,7 @@ func main() {
 	defer os.RemoveAll(dir)
 	os.Setenv("GOPATH", filepath.Join(dir, "_gopath"))
 
-	if err := os.WriteFile(filepath.Join(dir, "go.mod"), []byte("module go-test-nosplit\n"), 0666); err != nil {
+	if err := ioutil.WriteFile(filepath.Join(dir, "go.mod"), []byte("module go-test-nosplit\n"), 0666); err != nil {
 		log.Panic(err)
 	}
 
@@ -350,10 +351,10 @@ TestCases:
 			fmt.Printf("-- asm.s --\n%s", buf.String())
 		}
 
-		if err := os.WriteFile(filepath.Join(dir, "asm.s"), buf.Bytes(), 0666); err != nil {
+		if err := ioutil.WriteFile(filepath.Join(dir, "asm.s"), buf.Bytes(), 0666); err != nil {
 			log.Fatal(err)
 		}
-		if err := os.WriteFile(filepath.Join(dir, "main.go"), gobuf.Bytes(), 0666); err != nil {
+		if err := ioutil.WriteFile(filepath.Join(dir, "main.go"), gobuf.Bytes(), 0666); err != nil {
 			log.Fatal(err)
 		}
 
diff --git a/test/run.go b/test/run.go
index 038908f0dd8b85..7d5a558f2d2753 100644
--- a/test/run.go
+++ b/test/run.go
@@ -15,6 +15,7 @@ import (
 	"hash/fnv"
 	"io"
 	"io/fs"
+	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
@@ -312,8 +313,8 @@ func (t *test) goDirName() string {
 	return filepath.Join(t.dir, strings.Replace(t.gofile, ".go", ".dir", -1))
 }
 
-func goDirFiles(longdir string) (filter []os.DirEntry, err error) {
-	files, dirErr := os.ReadDir(longdir)
+func goDirFiles(longdir string) (filter []os.FileInfo, err error) {
+	files, dirErr := ioutil.ReadDir(longdir)
 	if dirErr != nil {
 		return nil, dirErr
 	}
@@ -328,7 +329,7 @@ func goDirFiles(longdir string) (filter []os.DirEntry, err error) {
 var packageRE = regexp.MustCompile(`(?m)^package ([\p{Lu}\p{Ll}\w]+)`)
 
 func getPackageNameFromSource(fn string) (string, error) {
-	data, err := os.ReadFile(fn)
+	data, err := ioutil.ReadFile(fn)
 	if err != nil {
 		return "", err
 	}
@@ -476,7 +477,7 @@ func (t *test) run() {
 		close(t.donec)
 	}()
 
-	srcBytes, err := os.ReadFile(t.goFileName())
+	srcBytes, err := ioutil.ReadFile(t.goFileName())
 	if err != nil {
 		t.err = err
 		return
@@ -599,7 +600,7 @@ func (t *test) run() {
 		defer os.RemoveAll(t.tempDir)
 	}
 
-	err = os.WriteFile(filepath.Join(t.tempDir, t.gofile), srcBytes, 0644)
+	err = ioutil.WriteFile(filepath.Join(t.tempDir, t.gofile), srcBytes, 0644)
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -956,7 +957,7 @@ func (t *test) run() {
 		}
 
 		modFile := fmt.Sprintf("module %s\ngo 1.14\n", modName)
-		if err := os.WriteFile(filepath.Join(gopathSrcDir, "go.mod"), []byte(modFile), 0666); err != nil {
+		if err := ioutil.WriteFile(filepath.Join(gopathSrcDir, "go.mod"), []byte(modFile), 0666); err != nil {
 			t.err = err
 			return
 		}
@@ -985,7 +986,7 @@ func (t *test) run() {
 		// Build an executable from all the .go and .s files in a subdirectory.
 		// Run it and verify its output in the buildrundir case.
 		longdir := filepath.Join(cwd, t.goDirName())
-		files, dirErr := os.ReadDir(longdir)
+		files, dirErr := ioutil.ReadDir(longdir)
 		if dirErr != nil {
 			t.err = dirErr
 			break
@@ -1003,7 +1004,7 @@ func (t *test) run() {
 		}
 		if len(asms) > 0 {
 			emptyHdrFile := filepath.Join(t.tempDir, "go_asm.h")
-			if err := os.WriteFile(emptyHdrFile, nil, 0666); err != nil {
+			if err := ioutil.WriteFile(emptyHdrFile, nil, 0666); err != nil {
 				t.err = fmt.Errorf("write empty go_asm.h: %s", err)
 				return
 			}
@@ -1147,7 +1148,7 @@ func (t *test) run() {
 			return
 		}
 		tfile := filepath.Join(t.tempDir, "tmp__.go")
-		if err := os.WriteFile(tfile, out, 0666); err != nil {
+		if err := ioutil.WriteFile(tfile, out, 0666); err != nil {
 			t.err = fmt.Errorf("write tempfile:%s", err)
 			return
 		}
@@ -1178,7 +1179,7 @@ func (t *test) run() {
 			return
 		}
 		tfile := filepath.Join(t.tempDir, "tmp__.go")
-		err = os.WriteFile(tfile, out, 0666)
+		err = ioutil.WriteFile(tfile, out, 0666)
 		if err != nil {
 			t.err = fmt.Errorf("write tempfile:%s", err)
 			return
@@ -1226,7 +1227,7 @@ func (t *test) String() string {
 
 func (t *test) makeTempDir() {
 	var err error
-	t.tempDir, err = os.MkdirTemp("", "")
+	t.tempDir, err = ioutil.TempDir("", "")
 	if err != nil {
 		log.Fatal(err)
 	}
@@ -1243,7 +1244,7 @@ func (t *test) checkExpectedOutput(gotBytes []byte) {
 	filename := filepath.Join(t.dir, t.gofile)
 	filename = filename[:len(filename)-len(".go")]
 	filename += ".out"
-	b, err := os.ReadFile(filename)
+	b, err := ioutil.ReadFile(filename)
 	// File is allowed to be missing (err != nil) in which case output should be empty.
 	got = strings.Replace(got, "\r\n", "\n", -1)
 	if got != string(b) {
@@ -1365,7 +1366,7 @@ func (t *test) errorCheck(outStr string, wantAuto bool, fullshort ...string) (er
 func (t *test) updateErrors(out, file string) {
 	base := path.Base(file)
 	// Read in source file.
-	src, err := os.ReadFile(file)
+	src, err := ioutil.ReadFile(file)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		return
@@ -1422,7 +1423,7 @@ func (t *test) updateErrors(out, file string) {
 		}
 	}
 	// Write new file.
-	err = os.WriteFile(file, []byte(strings.Join(lines, "\n")), 0640)
+	err = ioutil.WriteFile(file, []byte(strings.Join(lines, "\n")), 0640)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		return
@@ -1481,7 +1482,7 @@ var (
 func (t *test) wantedErrors(file, short string) (errs []wantedError) {
 	cache := make(map[string]*regexp.Regexp)
 
-	src, _ := os.ReadFile(file)
+	src, _ := ioutil.ReadFile(file)
 	for i, line := range strings.Split(string(src), "\n") {
 		lineNum := i + 1
 		if strings.Contains(line, "////") {
@@ -1624,7 +1625,7 @@ func (t *test) wantedAsmOpcodes(fn string) asmChecks {
 	ops := make(asmChecks)
 
 	comment := ""
-	src, _ := os.ReadFile(fn)
+	src, _ := ioutil.ReadFile(fn)
 	for i, line := range strings.Split(string(src), "\n") {
 		matches := rxAsmComment.FindStringSubmatch(line)
 		code, cmt := matches[1], matches[2]
diff --git a/test/sinit_run.go b/test/sinit_run.go
index 127c5abfcf164b..dcaf3383312602 100644
--- a/test/sinit_run.go
+++ b/test/sinit_run.go
@@ -12,12 +12,13 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"os"
 	"os/exec"
 )
 
 func main() {
-	f, err := os.CreateTemp("", "sinit-*.o")
+	f, err := ioutil.TempFile("", "sinit-*.o")
 	if err != nil {
 		fmt.Println(err)
 		os.Exit(1)
diff --git a/test/winbatch.go b/test/winbatch.go
index 86a68ca1eaa695..54c2fff13463bd 100644
--- a/test/winbatch.go
+++ b/test/winbatch.go
@@ -12,6 +12,7 @@ package main
 import (
 	"bytes"
 	"fmt"
+	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
@@ -49,7 +50,7 @@ func main() {
 }
 
 func enforceBatchStrictCRLF(path string) {
-	b, err := os.ReadFile(path)
+	b, err := ioutil.ReadFile(path)
 	if err != nil {
 		log.Fatalln(err)
 	}