all: update to use os.ReadFile, os.WriteFile, os.CreateTemp, os.MkdirTemp

As part of #42026, these helpers from io/ioutil were moved to os.
(ioutil.TempFile and TempDir became os.CreateTemp and MkdirTemp.)

Update the Go tree to use the preferred names.

As usual, code compiled with the Go 1.4 bootstrap toolchain
and code vendored from other sources is excluded.

ReadDir changes are in a separate CL, because they are not a
simple search and replace.

For #42026.

Change-Id: If318df0216d57e95ea0c4093b89f65e5b0ababb3
Reviewed-on: https://go-review.googlesource.com/c/go/+/266365
Trust: Russ Cox <rsc@golang.org>
Run-TryBot: Russ Cox <rsc@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Ian Lance Taylor <iant@golang.org>

6 files changed, 9 insertions, 12 deletions

diff --git a/src/internal/cpu/cpu_s390x_test.go b/src/internal/cpu/cpu_s390x_test.go
index d910bbe695..ad86858db0 100644
--- a/src/internal/cpu/cpu_s390x_test.go
+++ b/src/internal/cpu/cpu_s390x_test.go
@@ -7,13 +7,13 @@ package cpu_test
 import (
 	"errors"
 	. "internal/cpu"
-	"io/ioutil"
+	"os"
 	"regexp"
 	"testing"
 )
 
 func getFeatureList() ([]string, error) {
-	cpuinfo, err := ioutil.ReadFile("/proc/cpuinfo")
+	cpuinfo, err := os.ReadFile("/proc/cpuinfo")
 	if err != nil {
 		return nil, err
 	}
diff --git a/src/internal/obscuretestdata/obscuretestdata.go b/src/internal/obscuretestdata/obscuretestdata.go
index 06cd1df22c..5ea2cdf5d1 100644
--- a/src/internal/obscuretestdata/obscuretestdata.go
+++ b/src/internal/obscuretestdata/obscuretestdata.go
@@ -10,7 +10,6 @@ package obscuretestdata
 import (
 	"encoding/base64"
 	"io"
-	"io/ioutil"
 	"os"
 )
 
@@ -24,7 +23,7 @@ func DecodeToTempFile(name string) (path string, err error) {
 	}
 	defer f.Close()
 
-	tmp, err := ioutil.TempFile("", "obscuretestdata-decoded-")
+	tmp, err := os.CreateTemp("", "obscuretestdata-decoded-")
 	if err != nil {
 		return "", err
 	}
diff --git a/src/internal/poll/read_test.go b/src/internal/poll/read_test.go
index 2d4ef97da0..598a52ee44 100644
--- a/src/internal/poll/read_test.go
+++ b/src/internal/poll/read_test.go
@@ -5,7 +5,6 @@
 package poll_test
 
 import (
-	"io/ioutil"
 	"os"
 	"runtime"
 	"sync"
@@ -22,7 +21,7 @@ func TestRead(t *testing.T) {
 				go func(p string) {
 					defer wg.Done()
 					for i := 0; i < 100; i++ {
-						if _, err := ioutil.ReadFile(p); err != nil {
+						if _, err := os.ReadFile(p); err != nil {
 							t.Error(err)
 							return
 						}
diff --git a/src/internal/testenv/testenv_windows.go b/src/internal/testenv/testenv_windows.go
index eb8d6ac165..4802b13951 100644
--- a/src/internal/testenv/testenv_windows.go
+++ b/src/internal/testenv/testenv_windows.go
@@ -5,7 +5,6 @@
 package testenv
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sync"
@@ -16,7 +15,7 @@ var symlinkOnce sync.Once
 var winSymlinkErr error
 
 func initWinHasSymlink() {
-	tmpdir, err := ioutil.TempDir("", "symtest")
+	tmpdir, err := os.MkdirTemp("", "symtest")
 	if err != nil {
 		panic("failed to create temp directory: " + err.Error())
 	}
diff --git a/src/internal/trace/gc_test.go b/src/internal/trace/gc_test.go
index 4f9c77041a..9b9771e7b0 100644
--- a/src/internal/trace/gc_test.go
+++ b/src/internal/trace/gc_test.go
@@ -6,8 +6,8 @@ package trace
 
 import (
 	"bytes"
-	"io/ioutil"
 	"math"
+	"os"
 	"testing"
 	"time"
 )
@@ -84,7 +84,7 @@ func TestMMUTrace(t *testing.T) {
 		t.Skip("skipping in -short mode")
 	}
 
-	data, err := ioutil.ReadFile("testdata/stress_1_10_good")
+	data, err := os.ReadFile("testdata/stress_1_10_good")
 	if err != nil {
 		t.Fatalf("failed to read input file: %v", err)
 	}
@@ -126,7 +126,7 @@ func TestMMUTrace(t *testing.T) {
 }
 
 func BenchmarkMMU(b *testing.B) {
-	data, err := ioutil.ReadFile("testdata/stress_1_10_good")
+	data, err := os.ReadFile("testdata/stress_1_10_good")
 	if err != nil {
 		b.Fatalf("failed to read input file: %v", err)
 	}
diff --git a/src/internal/trace/parser_test.go b/src/internal/trace/parser_test.go
index 6d87970157..316220cfa8 100644
--- a/src/internal/trace/parser_test.go
+++ b/src/internal/trace/parser_test.go
@@ -47,7 +47,7 @@ func TestParseCanned(t *testing.T) {
 		if testing.Short() && info.Size() > 10000 {
 			continue
 		}
-		data, err := ioutil.ReadFile(name)
+		data, err := os.ReadFile(name)
 		if err != nil {
 			t.Fatal(err)
 		}