all: replace package ioutil with os and io in src

For #45557

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

Author: panjf2000

src/cmd/asm/internal/asm/endtoend_test.go

@@ -9,7 +9,6 @@ import (
 	"bytes"
 	"fmt"
 	"internal/buildcfg"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -51,7 +50,7 @@ func testEndToEnd(t *testing.T, goarch, file string) {
 	output := strings.Split(testOut.String(), "\n")
 
 	// Reconstruct expected output by independently "parsing" the input.
-	data, err := ioutil.ReadFile(input)
+	data, err := os.ReadFile(input)
 	if err != nil {
 		t.Error(err)
 		return
@@ -324,7 +323,7 @@ func testErrors(t *testing.T, goarch, file string, flags ...string) {
 	}
 
 	// Reconstruct expected errors by independently "parsing" the input.
-	data, err := ioutil.ReadFile(input)
+	data, err := os.ReadFile(input)
 	if err != nil {
 		t.Error(err)
 		return

src/cmd/cgo/main.go

@@ -18,7 +18,6 @@ import (
 	"go/token"
 	"internal/buildcfg"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"reflect"
@@ -345,7 +344,7 @@ func main() {
 			input = aname
 		}
 
-		b, err := ioutil.ReadFile(input)
+		b, err := os.ReadFile(input)
 		if err != nil {
 			fatalf("%s", err)
 		}

src/cmd/cgo/util.go

@@ -8,7 +8,6 @@ import (
 	"bytes"
 	"fmt"
 	"go/token"
-	"io/ioutil"
 	"os"
 	"os/exec"
 )
@@ -21,13 +20,13 @@ func run(stdin []byte, argv []string) (stdout, stderr []byte, ok bool) {
 		// Some compilers have trouble with standard input.
 		// Others have trouble with -xc.
 		// Avoid both problems by writing a file with a .c extension.
-		f, err := ioutil.TempFile("", "cgo-gcc-input-")
+		f, err := os.CreateTemp("", "cgo-gcc-input-")
 		if err != nil {
 			fatalf("%s", err)
 		}
 		name := f.Name()
 		f.Close()
-		if err := ioutil.WriteFile(name+".c", stdin, 0666); err != nil {
+		if err := os.WriteFile(name+".c", stdin, 0666); err != nil {
 			os.Remove(name)
 			fatalf("%s", err)
 		}

src/cmd/compile/internal/base/flag.go

@@ -9,7 +9,6 @@ import (
 	"flag"
 	"fmt"
 	"internal/buildcfg"
-	"io/ioutil"
 	"log"
 	"os"
 	"reflect"
@@ -392,7 +391,7 @@ func readImportCfg(file string) {
 		Flag.Cfg.ImportMap = make(map[string]string)
 	}
 	Flag.Cfg.PackageFile = map[string]string{}
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		log.Fatalf("-importcfg: %v", err)
 	}
@@ -432,7 +431,7 @@ func readImportCfg(file string) {
 }
 
 func readEmbedCfg(file string) {
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		log.Fatalf("-embedcfg: %v", err)
 	}

src/cmd/compile/internal/dwarfgen/scope_test.go

@@ -8,7 +8,6 @@ import (
 	"debug/dwarf"
 	"fmt"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -221,7 +220,7 @@ func TestScopeRanges(t *testing.T) {
 		t.Skip("skipping on plan9; no DWARF symbol table in executables")
 	}
 
-	dir, err := ioutil.TempDir("", "TestScopeRanges")
+	dir, err := os.MkdirTemp("", "TestScopeRanges")
 	if err != nil {
 		t.Fatalf("could not create directory: %v", err)
 	}
@@ -498,7 +497,7 @@ func TestEmptyDwarfRanges(t *testing.T) {
 		t.Skip("skipping on plan9; no DWARF symbol table in executables")
 	}
 
-	dir, err := ioutil.TempDir("", "TestEmptyDwarfRanges")
+	dir, err := os.MkdirTemp("", "TestEmptyDwarfRanges")
 	if err != nil {
 		t.Fatalf("could not create directory: %v", err)
 	}

src/cmd/compile/internal/importer/gcimporter.go

@@ -7,15 +7,15 @@ package importer
 
 import (
 	"bufio"
-	"cmd/compile/internal/types2"
 	"fmt"
 	"go/build"
 	"internal/pkgbits"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"strings"
+
+	"cmd/compile/internal/types2"
 )
 
 // debugging/development support
@@ -149,7 +149,7 @@ func Import(packages map[string]*types2.Package, path, srcDir string, lookup fun
 		if size >= 0 {
 			r = io.LimitReader(r, int64(size))
 		}
-		data, err = ioutil.ReadAll(r)
+		data, err = io.ReadAll(r)
 		if err != nil {
 			break
 		}

src/cmd/compile/internal/ir/mknode.go

@@ -18,7 +18,6 @@ import (
 	"go/parser"
 	"go/token"
 	"io/fs"
-	"io/ioutil"
 	"log"
 	"sort"
 	"strings"
@@ -160,7 +159,7 @@ func main() {
 		// write out mangled source so we can see the bug.
 		out = buf.Bytes()
 	}
-	err = ioutil.WriteFile("node_gen.go", out, 0666)
+	err = os.WriteFile("node_gen.go", out, 0666)
 	if err != nil {
 		log.Fatal(err)
 	}

src/cmd/compile/internal/logopt/logopt_test.go

@@ -6,7 +6,6 @@ package logopt
 
 import (
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -88,15 +87,15 @@ func TestLogOpt(t *testing.T) {
 
 	testenv.MustHaveGoBuild(t)
 
-	dir, err := ioutil.TempDir("", "TestLogOpt")
+	dir, err := os.MkdirTemp("", "TestLogOpt")
 	if err != nil {
 		t.Fatal(err)
 	}
 	defer os.RemoveAll(dir)
 
 	dir = fixSlash(dir) // Normalize the directory name as much as possible, for Windows testing
 	src := filepath.Join(dir, "file.go")
-	if err := ioutil.WriteFile(src, []byte(srcCode), 0644); err != nil {
+	if err := os.WriteFile(src, []byte(srcCode), 0644); err != nil {
 		t.Fatal(err)
 	}
 
@@ -146,7 +145,7 @@ func s15a8(x *[15]int64) [15]int64 {
 }
 `
 		copy := filepath.Join(dir, "copy.go")
-		if err := ioutil.WriteFile(copy, []byte(copyCode), 0644); err != nil {
+		if err := os.WriteFile(copy, []byte(copyCode), 0644); err != nil {
 			t.Fatal(err)
 		}
 		outcopy := filepath.Join(dir, "copy.o")
@@ -169,7 +168,7 @@ func s15a8(x *[15]int64) [15]int64 {
 				if err != nil {
 					t.Error("-json=0,file://log/opt should have succeeded")
 				}
-				logged, err := ioutil.ReadFile(filepath.Join(dir, "log", "opt", "x", "copy.json"))
+				logged, err := os.ReadFile(filepath.Join(dir, "log", "opt", "x", "copy.json"))
 				if err != nil {
 					t.Error("-json=0,file://log/opt missing expected log file")
 				}
@@ -196,7 +195,7 @@ func s15a8(x *[15]int64) [15]int64 {
 		if err != nil {
 			t.Error("-json=0,file://log/opt should have succeeded")
 		}
-		logged, err := ioutil.ReadFile(filepath.Join(dir, "log", "opt", "x", "file.json"))
+		logged, err := os.ReadFile(filepath.Join(dir, "log", "opt", "x", "file.json"))
 		if err != nil {
 			t.Error("-json=0,file://log/opt missing expected log file")
 		}

src/cmd/compile/internal/ssa/debug_lines_test.go

@@ -8,20 +8,18 @@ import (
 	"bufio"
 	"bytes"
 	"flag"
-	"internal/buildcfg"
-	"runtime"
-	"sort"
-	"strings"
-
 	"fmt"
+	"internal/buildcfg"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"reflect"
 	"regexp"
+	"runtime"
+	"sort"
 	"strconv"
+	"strings"
 	"testing"
 )
 
@@ -129,7 +127,7 @@ func TestDebugLines_53456(t *testing.T) {
 func compileAndDump(t *testing.T, file, function, moreGCFlags string) []byte {
 	testenv.MustHaveGoBuild(t)
 
-	tmpdir, err := ioutil.TempDir("", "debug_lines_test")
+	tmpdir, err := os.MkdirTemp("", "debug_lines_test")
 	if err != nil {
 		panic(fmt.Sprintf("Problem creating TempDir, error %v", err))
 	}

src/cmd/compile/internal/ssa/debug_test.go

@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"internal/testenv"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
@@ -223,7 +222,7 @@ func testNexting(t *testing.T, base, tag, gcflags string, count int, moreArgs ..
 
 	// Use a temporary directory unless -f is specified
 	if !*force {
-		tmpdir, err := ioutil.TempDir("", "debug_test")
+		tmpdir, err := os.MkdirTemp("", "debug_test")
 		if err != nil {
 			panic(fmt.Sprintf("Problem creating TempDir, error %v\n", err))
 		}
@@ -366,7 +365,7 @@ func (h *nextHist) write(filename string) {
 
 func (h *nextHist) read(filename string) {
 	h.f2i = make(map[string]uint8)
-	bytes, err := ioutil.ReadFile(filename)
+	bytes, err := os.ReadFile(filename)
 	if err != nil {
 		panic(fmt.Sprintf("Problem reading %s, error %v\n", filename, err))
 	}

src/cmd/compile/internal/ssa/gen/main.go

@@ -14,7 +14,6 @@ import (
 	"flag"
 	"fmt"
 	"go/format"
-	"io/ioutil"
 	"log"
 	"os"
 	"path"
@@ -500,7 +499,7 @@ func genOp() {
 		panic(err)
 	}
 
-	if err := ioutil.WriteFile("../opGen.go", b, 0666); err != nil {
+	if err := os.WriteFile("../opGen.go", b, 0666); err != nil {
 		log.Fatalf("can't write output: %v\n", err)
 	}
 
@@ -521,7 +520,7 @@ func genOp() {
 			log.Fatalf("bad opcode regexp %s: %v", pattern, err)
 		}
 
-		src, err := ioutil.ReadFile(a.genfile)
+		src, err := os.ReadFile(a.genfile)
 		if err != nil {
 			log.Fatalf("can't read %s: %v", a.genfile, err)
 		}

src/cmd/compile/internal/ssa/gen/rulegen.go

@@ -23,7 +23,6 @@ import (
 	"go/printer"
 	"go/token"
 	"io"
-	"io/ioutil"
 	"log"
 	"os"
 	"path"
@@ -280,7 +279,7 @@ func genRulesSuffix(arch arch, suff string) {
 	file, err := parser.ParseFile(fset, "", buf, parser.ParseComments)
 	if err != nil {
 		filename := fmt.Sprintf("%s_broken.go", arch.name)
-		if err := ioutil.WriteFile(filename, buf.Bytes(), 0644); err != nil {
+		if err := os.WriteFile(filename, buf.Bytes(), 0644); err != nil {
 			log.Printf("failed to dump broken code to %s: %v", filename, err)
 		} else {
 			log.Printf("dumped broken code to %s", filename)

src/cmd/compile/internal/ssagen/abi.go

@@ -7,7 +7,6 @@ package ssagen
 import (
 	"fmt"
 	"internal/buildcfg"
-	"io/ioutil"
 	"log"
 	"os"
 	"strings"
@@ -59,7 +58,7 @@ func (s *SymABIs) canonicalize(linksym string) string {
 // the symbol name and the third field is the ABI name, as one of the
 // named cmd/internal/obj.ABI constants.
 func (s *SymABIs) ReadSymABIs(file string) {
-	data, err := ioutil.ReadFile(file)
+	data, err := os.ReadFile(file)
 	if err != nil {
 		log.Fatalf("-symabis: %v", err)
 	}

src/cmd/compile/internal/staticdata/data.go

@@ -9,7 +9,6 @@ import (
 	"fmt"
 	"go/constant"
 	"io"
-	"io/ioutil"
 	"os"
 	"sort"
 	"strconv"
@@ -124,7 +123,7 @@ func fileStringSym(pos src.XPos, file string, readonly bool, hash []byte) (*obj.
 	}
 	size := info.Size()
 	if size <= 1*1024 {
-		data, err := ioutil.ReadAll(f)
+		data, err := io.ReadAll(f)
 		if err != nil {
 			return nil, 0, err
 		}

src/cmd/compile/internal/syntax/error_test.go

@@ -32,7 +32,6 @@ import (
 	"flag"
 	"fmt"
 	"internal/testenv"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -178,7 +177,7 @@ func testSyntaxErrors(t *testing.T, filename string) {
 func TestSyntaxErrors(t *testing.T) {
 	testenv.MustHaveGoBuild(t) // we need access to source (testdata)
 
-	list, err := ioutil.ReadDir(testdata)
+	list, err := os.ReadDir(testdata)
 	if err != nil {
 		t.Fatal(err)
 	}