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>

15 files changed, 37 insertions, 40 deletions

diff --git a/src/go/build/build_test.go b/src/go/build/build_test.go
index 5a4a2d62f5..5a3e9ee714 100644
--- a/src/go/build/build_test.go
+++ b/src/go/build/build_test.go
@@ -8,7 +8,6 @@ import (
 	"flag"
 	"internal/testenv"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -454,7 +453,7 @@ func TestImportDirNotExist(t *testing.T) {
 	testenv.MustHaveGoBuild(t) // really must just have source
 	ctxt := Default
 
-	emptyDir, err := ioutil.TempDir("", t.Name())
+	emptyDir, err := os.MkdirTemp("", t.Name())
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -592,7 +591,7 @@ func TestImportPackageOutsideModule(t *testing.T) {
 
 	// Create a GOPATH in a temporary directory. We don't use testdata
 	// because it's in GOROOT, which interferes with the module heuristic.
-	gopath, err := ioutil.TempDir("", "gobuild-notmodule")
+	gopath, err := os.MkdirTemp("", "gobuild-notmodule")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -600,7 +599,7 @@ func TestImportPackageOutsideModule(t *testing.T) {
 	if err := os.MkdirAll(filepath.Join(gopath, "src/example.com/p"), 0777); err != nil {
 		t.Fatal(err)
 	}
-	if err := ioutil.WriteFile(filepath.Join(gopath, "src/example.com/p/p.go"), []byte("package p"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(gopath, "src/example.com/p/p.go"), []byte("package p"), 0666); err != nil {
 		t.Fatal(err)
 	}
 
@@ -656,12 +655,12 @@ func TestIssue23594(t *testing.T) {
 // Verifies golang.org/issue/34752.
 func TestMissingImportErrorRepetition(t *testing.T) {
 	testenv.MustHaveGoBuild(t) // need 'go list' internally
-	tmp, err := ioutil.TempDir("", "")
+	tmp, err := os.MkdirTemp("", "")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer os.RemoveAll(tmp)
-	if err := ioutil.WriteFile(filepath.Join(tmp, "go.mod"), []byte("module m"), 0666); err != nil {
+	if err := os.WriteFile(filepath.Join(tmp, "go.mod"), []byte("module m"), 0666); err != nil {
 		t.Fatal(err)
 	}
 	defer os.Setenv("GO111MODULE", os.Getenv("GO111MODULE"))
diff --git a/src/go/doc/doc_test.go b/src/go/doc/doc_test.go
index ab98bed62b..cbdca62aa1 100644
--- a/src/go/doc/doc_test.go
+++ b/src/go/doc/doc_test.go
@@ -13,7 +13,7 @@ import (
 	"go/printer"
 	"go/token"
 	"io/fs"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -127,7 +127,7 @@ func test(t *testing.T, mode Mode) {
 		// update golden file if necessary
 		golden := filepath.Join(dataDir, fmt.Sprintf("%s.%d.golden", pkg.Name, mode))
 		if *update {
-			err := ioutil.WriteFile(golden, got, 0644)
+			err := os.WriteFile(golden, got, 0644)
 			if err != nil {
 				t.Error(err)
 			}
@@ -135,7 +135,7 @@ func test(t *testing.T, mode Mode) {
 		}
 
 		// get golden file
-		want, err := ioutil.ReadFile(golden)
+		want, err := os.ReadFile(golden)
 		if err != nil {
 			t.Error(err)
 			continue
diff --git a/src/go/format/benchmark_test.go b/src/go/format/benchmark_test.go
index 7bd45c0e95..ac19aa3bf5 100644
--- a/src/go/format/benchmark_test.go
+++ b/src/go/format/benchmark_test.go
@@ -12,7 +12,7 @@ import (
 	"flag"
 	"fmt"
 	"go/format"
-	"io/ioutil"
+	"os"
 	"testing"
 )
 
@@ -67,7 +67,7 @@ func BenchmarkFormat(b *testing.B) {
 
 		if *debug {
 			filename := t.name + ".src"
-			err := ioutil.WriteFile(filename, data, 0660)
+			err := os.WriteFile(filename, data, 0660)
 			if err != nil {
 				b.Fatalf("couldn't write %s: %v", filename, err)
 			}
diff --git a/src/go/format/format_test.go b/src/go/format/format_test.go
index 58e088ede3..27f4c74cdf 100644
--- a/src/go/format/format_test.go
+++ b/src/go/format/format_test.go
@@ -9,7 +9,7 @@ import (
 	"go/ast"
 	"go/parser"
 	"go/token"
-	"io/ioutil"
+	"os"
 	"strings"
 	"testing"
 )
@@ -38,7 +38,7 @@ func diff(t *testing.T, dst, src []byte) {
 }
 
 func TestNode(t *testing.T) {
-	src, err := ioutil.ReadFile(testfile)
+	src, err := os.ReadFile(testfile)
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -96,7 +96,7 @@ func TestNodeNoModify(t *testing.T) {
 }
 
 func TestSource(t *testing.T) {
-	src, err := ioutil.ReadFile(testfile)
+	src, err := os.ReadFile(testfile)
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/src/go/importer/importer_test.go b/src/go/importer/importer_test.go
index ff6e12c0da..0f5121d802 100644
--- a/src/go/importer/importer_test.go
+++ b/src/go/importer/importer_test.go
@@ -8,7 +8,6 @@ import (
 	"go/token"
 	"internal/testenv"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"runtime"
@@ -52,7 +51,7 @@ func TestForCompiler(t *testing.T) {
 		mathBigInt := pkg.Scope().Lookup("Int")
 		posn := fset.Position(mathBigInt.Pos()) // "$GOROOT/src/math/big/int.go:25:1"
 		filename := strings.Replace(posn.Filename, "$GOROOT", runtime.GOROOT(), 1)
-		data, err := ioutil.ReadFile(filename)
+		data, err := os.ReadFile(filename)
 		if err != nil {
 			t.Fatalf("can't read file containing declaration of math/big.Int: %v", err)
 		}
diff --git a/src/go/internal/gccgoimporter/importer_test.go b/src/go/internal/gccgoimporter/importer_test.go
index e4236a5867..35240c8fe6 100644
--- a/src/go/internal/gccgoimporter/importer_test.go
+++ b/src/go/internal/gccgoimporter/importer_test.go
@@ -7,7 +7,6 @@ package gccgoimporter
 import (
 	"go/types"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -150,7 +149,7 @@ func TestObjImporter(t *testing.T) {
 	}
 	t.Logf("gccgo version %d.%d", major, minor)
 
-	tmpdir, err := ioutil.TempDir("", "TestObjImporter")
+	tmpdir, err := os.MkdirTemp("", "TestObjImporter")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -159,7 +158,7 @@ func TestObjImporter(t *testing.T) {
 	initmap := make(map[*types.Package]InitData)
 	imp := GetImporter([]string{tmpdir}, initmap)
 
-	artmpdir, err := ioutil.TempDir("", "TestObjImporter")
+	artmpdir, err := os.MkdirTemp("", "TestObjImporter")
 	if err != nil {
 		t.Fatal(err)
 	}
diff --git a/src/go/internal/gcimporter/gcimporter_test.go b/src/go/internal/gcimporter/gcimporter_test.go
index 663753a18a..8991e3bdee 100644
--- a/src/go/internal/gcimporter/gcimporter_test.go
+++ b/src/go/internal/gcimporter/gcimporter_test.go
@@ -94,7 +94,7 @@ func testDir(t *testing.T, dir string, endTime time.Time) (nimports int) {
 }
 
 func mktmpdir(t *testing.T) string {
-	tmpdir, err := ioutil.TempDir("", "gcimporter_test")
+	tmpdir, err := os.MkdirTemp("", "gcimporter_test")
 	if err != nil {
 		t.Fatal("mktmpdir:", err)
 	}
@@ -199,7 +199,7 @@ func TestVersionHandling(t *testing.T) {
 
 		// create file with corrupted export data
 		// 1) read file
-		data, err := ioutil.ReadFile(filepath.Join(dir, name))
+		data, err := os.ReadFile(filepath.Join(dir, name))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -216,7 +216,7 @@ func TestVersionHandling(t *testing.T) {
 		// 4) write the file
 		pkgpath += "_corrupted"
 		filename := filepath.Join(corruptdir, pkgpath) + ".a"
-		ioutil.WriteFile(filename, data, 0666)
+		os.WriteFile(filename, data, 0666)
 
 		// test that importing the corrupted file results in an error
 		_, err = Import(fset, make(map[string]*types.Package), pkgpath, corruptdir, nil)
diff --git a/src/go/internal/srcimporter/srcimporter.go b/src/go/internal/srcimporter/srcimporter.go
index 90bb3a9bc1..c4d501dcd9 100644
--- a/src/go/internal/srcimporter/srcimporter.go
+++ b/src/go/internal/srcimporter/srcimporter.go
@@ -14,7 +14,6 @@ import (
 	"go/token"
 	"go/types"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -200,7 +199,7 @@ func (p *Importer) parseFiles(dir string, filenames []string) ([]*ast.File, erro
 }
 
 func (p *Importer) cgo(bp *build.Package) (*ast.File, error) {
-	tmpdir, err := ioutil.TempDir("", "srcimporter")
+	tmpdir, err := os.MkdirTemp("", "srcimporter")
 	if err != nil {
 		return nil, err
 	}
diff --git a/src/go/parser/interface.go b/src/go/parser/interface.go
index d5c18a9e2d..41d9a52847 100644
--- a/src/go/parser/interface.go
+++ b/src/go/parser/interface.go
@@ -14,6 +14,7 @@ import (
 	"io"
 	"io/fs"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 )
@@ -39,7 +40,7 @@ func readSource(filename string, src interface{}) ([]byte, error) {
 		}
 		return nil, errors.New("invalid source")
 	}
-	return ioutil.ReadFile(filename)
+	return os.ReadFile(filename)
 }
 
 // A Mode value is a set of flags (or 0).
diff --git a/src/go/parser/performance_test.go b/src/go/parser/performance_test.go
index f2732c0e2b..f81bcee969 100644
--- a/src/go/parser/performance_test.go
+++ b/src/go/parser/performance_test.go
@@ -6,14 +6,14 @@ package parser
 
 import (
 	"go/token"
-	"io/ioutil"
+	"os"
 	"testing"
 )
 
 var src = readFile("parser.go")
 
 func readFile(filename string) []byte {
-	data, err := ioutil.ReadFile(filename)
+	data, err := os.ReadFile(filename)
 	if err != nil {
 		panic(err)
 	}
diff --git a/src/go/printer/performance_test.go b/src/go/printer/performance_test.go
index e23de3fbae..e655fa13ee 100644
--- a/src/go/printer/performance_test.go
+++ b/src/go/printer/performance_test.go
@@ -12,8 +12,8 @@ import (
 	"go/ast"
 	"go/parser"
 	"io"
-	"io/ioutil"
 	"log"
+	"os"
 	"testing"
 )
 
@@ -29,7 +29,7 @@ func testprint(out io.Writer, file *ast.File) {
 func initialize() {
 	const filename = "testdata/parser.go"
 
-	src, err := ioutil.ReadFile(filename)
+	src, err := os.ReadFile(filename)
 	if err != nil {
 		log.Fatalf("%s", err)
 	}
diff --git a/src/go/printer/printer_test.go b/src/go/printer/printer_test.go
index b64bc6bfb7..45e501115a 100644
--- a/src/go/printer/printer_test.go
+++ b/src/go/printer/printer_test.go
@@ -13,7 +13,7 @@ import (
 	"go/parser"
 	"go/token"
 	"io"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"testing"
 	"time"
@@ -119,7 +119,7 @@ func diff(aname, bname string, a, b []byte) error {
 }
 
 func runcheck(t *testing.T, source, golden string, mode checkMode) {
-	src, err := ioutil.ReadFile(source)
+	src, err := os.ReadFile(source)
 	if err != nil {
 		t.Error(err)
 		return
@@ -133,14 +133,14 @@ func runcheck(t *testing.T, source, golden string, mode checkMode) {
 
 	// update golden files if necessary
 	if *update {
-		if err := ioutil.WriteFile(golden, res, 0644); err != nil {
+		if err := os.WriteFile(golden, res, 0644); err != nil {
 			t.Error(err)
 		}
 		return
 	}
 
 	// get golden
-	gld, err := ioutil.ReadFile(golden)
+	gld, err := os.ReadFile(golden)
 	if err != nil {
 		t.Error(err)
 		return
@@ -552,7 +552,7 @@ func TestBaseIndent(t *testing.T) {
 	// are not indented (because their values must not change) and make
 	// this test fail.
 	const filename = "printer.go"
-	src, err := ioutil.ReadFile(filename)
+	src, err := os.ReadFile(filename)
 	if err != nil {
 		panic(err) // error in test
 	}
@@ -639,7 +639,7 @@ func (l *limitWriter) Write(buf []byte) (n int, err error) {
 func TestWriteErrors(t *testing.T) {
 	t.Parallel()
 	const filename = "printer.go"
-	src, err := ioutil.ReadFile(filename)
+	src, err := os.ReadFile(filename)
 	if err != nil {
 		panic(err) // error in test
 	}
diff --git a/src/go/scanner/scanner_test.go b/src/go/scanner/scanner_test.go
index 9d3bbbbb24..ab4c2dd962 100644
--- a/src/go/scanner/scanner_test.go
+++ b/src/go/scanner/scanner_test.go
@@ -6,7 +6,6 @@ package scanner
 
 import (
 	"go/token"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -893,7 +892,7 @@ func BenchmarkScan(b *testing.B) {
 func BenchmarkScanFile(b *testing.B) {
 	b.StopTimer()
 	const filename = "scanner.go"
-	src, err := ioutil.ReadFile(filename)
+	src, err := os.ReadFile(filename)
 	if err != nil {
 		panic(err)
 	}
diff --git a/src/go/types/check_test.go b/src/go/types/check_test.go
index 37b287a20d..841ca24511 100644
--- a/src/go/types/check_test.go
+++ b/src/go/types/check_test.go
@@ -34,6 +34,7 @@ import (
 	"go/token"
 	"internal/testenv"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -153,7 +154,7 @@ func errMap(t *testing.T, testname string, files []*ast.File) map[string][]strin
 
 	for _, file := range files {
 		filename := fset.Position(file.Package).Filename
-		src, err := ioutil.ReadFile(filename)
+		src, err := os.ReadFile(filename)
 		if err != nil {
 			t.Fatalf("%s: could not read %s", testname, filename)
 		}
diff --git a/src/go/types/hilbert_test.go b/src/go/types/hilbert_test.go
index 9783ce6dc9..77954d2f8b 100644
--- a/src/go/types/hilbert_test.go
+++ b/src/go/types/hilbert_test.go
@@ -12,7 +12,7 @@ import (
 	"go/importer"
 	"go/parser"
 	"go/token"
-	"io/ioutil"
+	"os"
 	"testing"
 
 	. "go/types"
@@ -27,7 +27,7 @@ func TestHilbert(t *testing.T) {
 	// generate source
 	src := program(*H, *out)
 	if *out != "" {
-		ioutil.WriteFile(*out, src, 0666)
+		os.WriteFile(*out, src, 0666)
 		return
 	}