all: update references to symbols moved from io/ioutil to io

Update references missed in CL 263142.

For #41190

Change-Id: I778760a6a69bd0440fec0848bdef539c9ccb4ee1
GitHub-Last-Rev: dda42b09fff36dc08ec1cdec50cc19e3da5058e5
GitHub-Pull-Request: golang/go#42874
Reviewed-on: https://go-review.googlesource.com/c/go/+/273946
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>
Trust: Cherry Zhang <cherryyz@google.com>

24 files changed, 74 insertions, 93 deletions

diff --git a/misc/android/go_android_exec.go b/misc/android/go_android_exec.go
index 7aa7fe56fc..3af2bee583 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"
@@ -276,7 +275,7 @@ 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
 	}
@@ -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 b2701bf922..fc687567bf 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 1bdf843451..a077b59478 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 4a46b6023b..0f39dc8e54 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 3c95d87d8a..0becb262b4 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 ab5d328f67..675418f98d 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 a1c7cacde7..cf34ce8db6 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 94abaa03e8..14013a4cd9 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 6a5adf79ca..ec717c4f8b 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/testcarchive/testdata/libgo6/sigprof.go b/misc/cgo/testcarchive/testdata/libgo6/sigprof.go
index 4cb05dc617..31527c59af 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/testcshared/cshared_test.go b/misc/cgo/testcshared/cshared_test.go
index 3a4886cf30..90d8c365e6 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 4c2312c1c8..aae3404360 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 8869528015..b894e8d30d 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 dab13364b8..384b6250e1 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 b98360c4ae..8fd03715a1 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/testsanitizers/testdata/tsan9.go b/misc/cgo/testsanitizers/testdata/tsan9.go
index f166d8b495..06304be751 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/cgo/testshared/shared_test.go b/misc/cgo/testshared/shared_test.go
index f52391c6f6..e77f848915 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 57f0fd34f7..1c97ae9bcb 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 57f0fd34f7..1c97ae9bcb 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 d32bcc3202..cde5723892 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 0acf1b259c..9e63717d92 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/linkcheck/linkcheck.go b/misc/linkcheck/linkcheck.go
index d9bfd2f767..570b430da4 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/misc/reboot/experiment_toolid_test.go b/misc/reboot/experiment_toolid_test.go
index eabf06b19e..4f40284d80 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 717c0fb709..6bafc608b5 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)
 	}