x/tools: assume go1.22 and simplify

This CL does not include simplifications to gopls.

Updates golang/go#65917
Updates golang/go#69095

Change-Id: I2b54992681e2c671324e22668d8401962a1d2363
Reviewed-on: https://go-review.googlesource.com/c/tools/+/593683
Reviewed-by: Robert Findley <rfindley@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>

cmd/bisect/go119.go

@@ -1,13 +0,0 @@
-// Copyright 2023 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !go1.20
-
-package main
-
-import "os/exec"
-
-func cmdInterrupt(cmd *exec.Cmd) {
-	// cmd.Cancel and cmd.WaitDelay not available before Go 1.20.
-}

cmd/bisect/go120.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.20
-
 package main
 
 import (

cmd/bisect/rand.go

@@ -1,20 +0,0 @@
-// Copyright 2023 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-// Starting in Go 1.20, the global rand is auto-seeded,
-// with a better value than the current Unix nanoseconds.
-// Only seed if we're using older versions of Go.
-
-//go:build !go1.20
-
-package main
-
-import (
-	"math/rand"
-	"time"
-)
-
-func init() {
-	rand.Seed(time.Now().UnixNano())
-}

cmd/deadcode/deadcode.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.20
-
 package main
 
 import (

cmd/deadcode/deadcode_test.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.20
-
 package main_test
 
 import (

go/analysis/internal/checker/checker_test.go

@@ -223,10 +223,6 @@ func NewT1() *T1 { return &T1{T} }
 		// duplicate list errors with findings (issue #67790)
 		{name: "list-error-findings", pattern: []string{cperrFile}, analyzers: []*analysis.Analyzer{renameAnalyzer}, code: 3},
 	} {
-		if test.name == "despite-error" && testenv.Go1Point() < 20 {
-			// The behavior in the comment on the despite-error test only occurs for Go 1.20+.
-			continue
-		}
 		if got := checker.Run(test.pattern, test.analyzers); got != test.code {
 			t.Errorf("got incorrect exit code %d for test %s; want %d", got, test.name, test.code)
 		}

go/analysis/passes/directive/directive_test.go

@@ -10,11 +10,9 @@ import (
 	"golang.org/x/tools/go/analysis"
 	"golang.org/x/tools/go/analysis/analysistest"
 	"golang.org/x/tools/go/analysis/passes/directive"
-	"golang.org/x/tools/internal/testenv"
 )
 
 func Test(t *testing.T) {
-	testenv.NeedsGo1Point(t, 16)
 	analyzer := *directive.Analyzer
 	analyzer.Run = func(pass *analysis.Pass) (interface{}, error) {
 		defer func() {

go/analysis/passes/loopclosure/loopclosure_test.go

@@ -10,29 +10,10 @@ import (
 
 	"golang.org/x/tools/go/analysis/analysistest"
 	"golang.org/x/tools/go/analysis/passes/loopclosure"
-	"golang.org/x/tools/internal/testenv"
 	"golang.org/x/tools/internal/testfiles"
 )
 
-func Test(t *testing.T) {
-	// legacy loopclosure test expectations are incorrect > 1.21.
-	testenv.SkipAfterGo1Point(t, 21)
-
-	testdata := analysistest.TestData()
-	analysistest.Run(t, testdata, loopclosure.Analyzer,
-		"a", "golang.org/...", "subtests", "typeparams")
-}
-
-func TestVersions22(t *testing.T) {
-	t.Skip("Disabled for golang.org/cl/603895. Fix and re-enable.")
-	testenv.NeedsGo1Point(t, 22)
-
+func TestVersions(t *testing.T) {
 	dir := testfiles.ExtractTxtarFileToTmp(t, filepath.Join(analysistest.TestData(), "src", "versions", "go22.txtar"))
 	analysistest.Run(t, dir, loopclosure.Analyzer, "golang.org/fake/versions")
 }
-
-func TestVersions18(t *testing.T) {
-	t.Skip("Disabled for golang.org/cl/603895. Fix and re-enable.")
-	dir := testfiles.ExtractTxtarFileToTmp(t, filepath.Join(analysistest.TestData(), "src", "versions", "go18.txtar"))
-	analysistest.Run(t, dir, loopclosure.Analyzer, "golang.org/fake/versions")
-}

go/analysis/passes/loopclosure/testdata/src/versions/go22.txtar

@@ -1,13 +1,13 @@
 Test loopclosure at go version go1.22.
 
-The go1.19 build tag is necessary to force the file version.
+The go1.21 build tag is necessary to force the file version.
 
 -- go.mod --
 module golang.org/fake/versions
 
 go 1.22
 -- pre.go --
-//go:build go1.19
+//go:build go1.21
 
 package versions
 

go/analysis/passes/slog/slog_test.go

@@ -8,11 +8,9 @@ import (
 	"testing"
 
 	"golang.org/x/tools/go/analysis/analysistest"
-	"golang.org/x/tools/internal/testenv"
 )
 
 func Test(t *testing.T) {
-	testenv.NeedsGo1Point(t, 21)
 	testdata := analysistest.TestData()
 	analysistest.Run(t, testdata, Analyzer, "a", "b")
 }

go/analysis/passes/stdversion/stdversion_test.go

@@ -10,7 +10,6 @@ import (
 
 	"golang.org/x/tools/go/analysis/analysistest"
 	"golang.org/x/tools/go/analysis/passes/stdversion"
-	"golang.org/x/tools/internal/testenv"
 	"golang.org/x/tools/internal/testfiles"
 )
 
@@ -18,8 +17,6 @@ func Test(t *testing.T) {
 	t.Skip("Disabled for golang.org/cl/603895. Fix and re-enable.")
 	// The test relies on go1.21 std symbols, but the analyzer
 	// itself requires the go1.22 implementation of versions.FileVersions.
-	testenv.NeedsGo1Point(t, 22)
-
 	dir := testfiles.ExtractTxtarFileToTmp(t, filepath.Join(analysistest.TestData(), "test.txtar"))
 	analysistest.Run(t, dir, stdversion.Analyzer,
 		"example.com/a",

go/ssa/interp/interp_go120_test.go

@@ -1,12 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.20
-// +build go1.20
-
-package interp_test
-
-func init() {
-	testdataTests = append(testdataTests, "slice2array.go")
-}

go/ssa/interp/interp_go121_test.go

@@ -1,12 +0,0 @@
-// Copyright 2023 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.21
-// +build go1.21
-
-package interp_test
-
-func init() {
-	testdataTests = append(testdataTests, "minmax.go")
-}

go/ssa/interp/interp_go122_test.go

@@ -2,9 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.22
-// +build go1.22
-
 package interp_test
 
 import (
@@ -19,13 +16,6 @@ import (
 	"golang.org/x/tools/internal/testenv"
 )
 
-func init() {
-	testdataTests = append(testdataTests,
-		"rangevarlifetime_go122.go",
-		"forvarlifetime_go122.go",
-	)
-}
-
 // TestExperimentRange tests files in testdata with GOEXPERIMENT=range set.
 func TestExperimentRange(t *testing.T) {
 	testenv.NeedsGoExperiment(t, "range")

go/ssa/interp/interp_test.go

@@ -137,6 +137,10 @@ var testdataTests = []string{
 	"fixedbugs/issue66783.go",
 	"typeassert.go",
 	"zeros.go",
+	"slice2array.go",
+	"minmax.go",
+	"rangevarlifetime_go122.go",
+	"forvarlifetime_go122.go",
 }
 
 func init() {

go/ssa/interp/testdata/forvarlifetime_go122.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.22
-
 package main
 
 import (

go/ssa/interp/testdata/forvarlifetime_old.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.19
+//go:build go1.21
 
 // goversion can be pinned to anything strictly before 1.22.
 

go/ssa/interp/testdata/rangevarlifetime_old.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.19
+//go:build go1.21
 
 // goversion can be pinned to anything strictly before 1.22.
 

internal/aliases/aliases_test.go

@@ -67,7 +67,7 @@ func TestNewAlias(t *testing.T) {
 				t.Errorf("Expected Unalias(A)==%q. got %q", want, got)
 			}
 
-			if testenv.Go1Point() >= 22 && godebug != "gotypesalias=0" {
+			if godebug != "gotypesalias=0" {
 				if _, ok := A.Type().(*types.Alias); !ok {
 					t.Errorf("Expected A.Type() to be a types.Alias(). got %q", A.Type())
 				}

internal/analysisinternal/analysis.go

@@ -415,8 +415,7 @@ func CheckReadable(pass *analysis.Pass, filename string) error {
 		return nil
 	}
 	for _, f := range pass.Files {
-		// TODO(adonovan): use go1.20 f.FileStart
-		if pass.Fset.File(f.Pos()).Name() == filename {
+		if pass.Fset.File(f.FileStart).Name() == filename {
 			return nil
 		}
 	}

internal/gcimporter/bimport.go

@@ -138,8 +138,13 @@ func predeclared() []types.Type {
 
 			// used internally by gc; never used by this package or in .a files
 			anyType{},
+
+			// comparable
+			types.Universe.Lookup("comparable").Type(),
+
+			// any
+			types.Universe.Lookup("any").Type(),
 		}
-		predecl = append(predecl, additionalPredeclared()...)
 	})
 	return predecl
 }

internal/gcimporter/gcimporter.go

@@ -232,14 +232,19 @@ func Import(packages map[string]*types.Package, path, srcDir string, lookup func
 		// Select appropriate importer.
 		if len(data) > 0 {
 			switch data[0] {
-			case 'v', 'c', 'd': // binary, till go1.10
+			case 'v', 'c', 'd':
+				// binary: emitted by cmd/compile till go1.10; obsolete.
 				return nil, fmt.Errorf("binary (%c) import format is no longer supported", data[0])
 
-			case 'i': // indexed, till go1.19
+			case 'i':
+				// indexed: emitted by cmd/compile till go1.19;
+				// now used only for serializing go/types.
+				// See https://github.com/golang/go/issues/69491.
 				_, pkg, err := IImportData(fset, packages, data[1:], id)
 				return pkg, err
 
-			case 'u': // unified, from go1.20
+			case 'u':
+				// unified: emitted by cmd/compile since go1.20.
 				_, pkg, err := UImportData(fset, packages, data[1:size], id)
 				return pkg, err
 

internal/gcimporter/iexport.go

@@ -242,7 +242,6 @@ import (
 
 	"golang.org/x/tools/go/types/objectpath"
 	"golang.org/x/tools/internal/aliases"
-	"golang.org/x/tools/internal/tokeninternal"
 )
 
 // IExportShallow encodes "shallow" export data for the specified package.
@@ -441,7 +440,7 @@ func (p *iexporter) encodeFile(w *intWriter, file *token.File, needed []uint64)
 	// Sort the set of needed offsets. Duplicates are harmless.
 	sort.Slice(needed, func(i, j int) bool { return needed[i] < needed[j] })
 
-	lines := tokeninternal.GetLines(file) // byte offset of each line start
+	lines := file.Lines() // byte offset of each line start
 	w.uint64(uint64(len(lines)))
 
 	// Rather than record the entire array of line start offsets,

internal/gcimporter/iexport_common_test.go

@@ -9,8 +9,4 @@ package gcimporter
 
 var IExportCommon = iexportCommon
 
-const (
-	IExportVersion         = iexportVersion
-	IExportVersionGenerics = iexportVersionGenerics
-	IExportVersionGo1_18   = iexportVersionGo1_18
-)
+const IExportVersion = iexportVersionGenerics

internal/gcimporter/iexport_test.go

@@ -4,9 +4,6 @@
 
 // This is a copy of bexport_test.go for iexport.go.
 
-//go:build go1.11
-// +build go1.11
-
 package gcimporter_test
 
 import (

internal/gcimporter/iimport.go

@@ -53,6 +53,7 @@ const (
 	iexportVersionPosCol   = 1
 	iexportVersionGo1_18   = 2
 	iexportVersionGenerics = 2
+	iexportVersion         = iexportVersionGenerics
 
 	iexportVersionCurrent = 2
 )

internal/gcimporter/support_go118.go

@@ -1,34 +0,0 @@
-// Copyright 2021 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package gcimporter
-
-import "go/types"
-
-const iexportVersion = iexportVersionGenerics
-
-// additionalPredeclared returns additional predeclared types in go.1.18.
-func additionalPredeclared() []types.Type {
-	return []types.Type{
-		// comparable
-		types.Universe.Lookup("comparable").Type(),
-
-		// any
-		types.Universe.Lookup("any").Type(),
-	}
-}
-
-// See cmd/compile/internal/types.SplitVargenSuffix.
-func splitVargenSuffix(name string) (base, suffix string) {
-	i := len(name)
-	for i > 0 && name[i-1] >= '0' && name[i-1] <= '9' {
-		i--
-	}
-	const dot = "·"
-	if i >= len(dot) && name[i-len(dot):i] == dot {
-		i -= len(dot)
-		return name[:i], name[i:]
-	}
-	return name, ""
-}

internal/gcimporter/ureader_yes.go

@@ -738,3 +738,17 @@ func pkgScope(pkg *types.Package) *types.Scope {
 	}
 	return types.Universe
 }
+
+// See cmd/compile/internal/types.SplitVargenSuffix.
+func splitVargenSuffix(name string) (base, suffix string) {
+	i := len(name)
+	for i > 0 && name[i-1] >= '0' && name[i-1] <= '9' {
+		i--
+	}
+	const dot = "·"
+	if i >= len(dot) && name[i-len(dot):i] == dot {
+		i -= len(dot)
+		return name[:i], name[i:]
+	}
+	return name, ""
+}

internal/gocommand/invoke.go

@@ -16,7 +16,6 @@ import (
 	"os"
 	"os/exec"
 	"path/filepath"
-	"reflect"
 	"regexp"
 	"runtime"
 	"strconv"
@@ -250,16 +249,13 @@ func (i *Invocation) run(ctx context.Context, stdout, stderr io.Writer) error {
 	cmd.Stdout = stdout
 	cmd.Stderr = stderr
 
-	// cmd.WaitDelay was added only in go1.20 (see #50436).
-	if waitDelay := reflect.ValueOf(cmd).Elem().FieldByName("WaitDelay"); waitDelay.IsValid() {
-		// https://go.dev/issue/59541: don't wait forever copying stderr
-		// after the command has exited.
-		// After CL 484741 we copy stdout manually, so we we'll stop reading that as
-		// soon as ctx is done. However, we also don't want to wait around forever
-		// for stderr. Give a much-longer-than-reasonable delay and then assume that
-		// something has wedged in the kernel or runtime.
-		waitDelay.Set(reflect.ValueOf(30 * time.Second))
-	}
+	// https://go.dev/issue/59541: don't wait forever copying stderr
+	// after the command has exited.
+	// After CL 484741 we copy stdout manually, so we we'll stop reading that as
+	// soon as ctx is done. However, we also don't want to wait around forever
+	// for stderr. Give a much-longer-than-reasonable delay and then assume that
+	// something has wedged in the kernel or runtime.
+	cmd.WaitDelay = 30 * time.Second
 
 	// The cwd gets resolved to the real path. On Darwin, where
 	// /tmp is a symlink, this breaks anything that expects the

internal/imports/mod_go122_test.go

@@ -1,58 +0,0 @@
-// Copyright 2019 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.22
-// +build go1.22
-
-package imports
-
-import (
-	"context"
-	"testing"
-)
-
-// Tests that go.work files and vendor directory are respected.
-func TestModWorkspaceVendoring(t *testing.T) {
-	mt := setup(t, nil, `
--- go.work --
-go 1.22
-
-use (
-	./a
-	./b
-)
--- a/go.mod --
-module example.com/a
-
-go 1.22
-
-require rsc.io/sampler v1.3.1
--- a/a.go --
-package a
-
-import _ "rsc.io/sampler"
--- b/go.mod --
-module example.com/b
-
-go 1.22
--- b/b.go --
-package b
-`, "")
-	defer mt.cleanup()
-
-	// generate vendor directory
-	if _, err := mt.env.invokeGo(context.Background(), "work", "vendor"); err != nil {
-		t.Fatal(err)
-	}
-
-	// update module resolver
-	mt.env.ClearModuleInfo()
-	mt.env.UpdateResolver(mt.env.resolver.ClearForNewScan())
-
-	mt.assertModuleFoundInDir("example.com/a", "a", `main/a$`)
-	mt.assertScanFinds("example.com/a", "a")
-	mt.assertModuleFoundInDir("example.com/b", "b", `main/b$`)
-	mt.assertScanFinds("example.com/b", "b")
-	mt.assertModuleFoundInDir("rsc.io/sampler", "sampler", `/vendor/`)
-}

internal/imports/mod_test.go

@@ -267,10 +267,7 @@ import _ "rsc.io/sampler"
 		t.Fatal(err)
 	}
 
-	wantDir := `pkg.*mod.*/sampler@.*$`
-	if testenv.Go1Point() >= 14 {
-		wantDir = `/vendor/`
-	}
+	wantDir := `/vendor/`
 
 	// Clear out the resolver's module info, since we've changed the environment.
 	// (the presence of a /vendor directory affects `go list -m`).
@@ -1323,3 +1320,48 @@ func BenchmarkModuleResolver_InitialScan(b *testing.B) {
 		scanToSlice(resolver, exclude)
 	}
 }
+
+// Tests that go.work files and vendor directory are respected.
+func TestModWorkspaceVendoring(t *testing.T) {
+	mt := setup(t, nil, `
+-- go.work --
+go 1.22
+
+use (
+	./a
+	./b
+)
+-- a/go.mod --
+module example.com/a
+
+go 1.22
+
+require rsc.io/sampler v1.3.1
+-- a/a.go --
+package a
+
+import _ "rsc.io/sampler"
+-- b/go.mod --
+module example.com/b
+
+go 1.22
+-- b/b.go --
+package b
+`, "")
+	defer mt.cleanup()
+
+	// generate vendor directory
+	if _, err := mt.env.invokeGo(context.Background(), "work", "vendor"); err != nil {
+		t.Fatal(err)
+	}
+
+	// update module resolver
+	mt.env.ClearModuleInfo()
+	mt.env.UpdateResolver(mt.env.resolver.ClearForNewScan())
+
+	mt.assertModuleFoundInDir("example.com/a", "a", `main/a$`)
+	mt.assertScanFinds("example.com/a", "a")
+	mt.assertModuleFoundInDir("example.com/b", "b", `main/b$`)
+	mt.assertScanFinds("example.com/b", "b")
+	mt.assertModuleFoundInDir("rsc.io/sampler", "sampler", `/vendor/`)
+}

internal/proxydir/proxydir.go

@@ -14,8 +14,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-
-	"golang.org/x/tools/internal/testenv"
 )
 
 // WriteModuleVersion creates a directory in the proxy dir for a module.
@@ -82,18 +80,10 @@ func checkClose(name string, closer io.Closer, err *error) {
 
 // ToURL returns the file uri for a proxy directory.
 func ToURL(dir string) string {
-	if testenv.Go1Point() >= 13 {
-		// file URLs on Windows must start with file:///. See golang.org/issue/6027.
-		path := filepath.ToSlash(dir)
-		if !strings.HasPrefix(path, "/") {
-			path = "/" + path
-		}
-		return "file://" + path
-	} else {
-		// Prior to go1.13, the Go command on Windows only accepted GOPROXY file URLs
-		// of the form file://C:/path/to/proxy. This was incorrect: when parsed, "C:"
-		// is interpreted as the host. See golang.org/issue/6027. This has been
-		// fixed in go1.13, but we emit the old format for old releases.
-		return "file://" + filepath.ToSlash(dir)
+	// file URLs on Windows must start with file:///. See golang.org/issue/6027.
+	path := filepath.ToSlash(dir)
+	if !strings.HasPrefix(path, "/") {
+		path = "/" + path
 	}
+	return "file://" + path
 }

internal/refactor/inline/analyzer/analyzer.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.20
-
 package analyzer
 
 import (

internal/refactor/inline/analyzer/analyzer_test.go

@@ -2,8 +2,6 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-//go:build go1.20
-
 package analyzer_test
 
 import (

internal/refactor/inline/inline.go

@@ -15,6 +15,7 @@ import (
 	"go/types"
 	pathpkg "path"
 	"reflect"
+	"slices"
 	"strconv"
 	"strings"
 
@@ -151,7 +152,7 @@ func (st *state) inline() (*Result, error) {
 	elideBraces := res.elideBraces
 	if !elideBraces {
 		if newBlock, ok := res.new.(*ast.BlockStmt); ok {
-			i := nodeIndex(caller.path, res.old)
+			i := slices.Index(caller.path, res.old)
 			parent := caller.path[i+1]
 			var body []ast.Stmt
 			switch parent := parent.(type) {
@@ -2465,7 +2466,7 @@ func callStmt(callPath []ast.Node, unrestricted bool) *ast.ExprStmt {
 	parent, _ := callContext(callPath)
 	stmt, ok := parent.(*ast.ExprStmt)
 	if ok && unrestricted {
-		switch callPath[nodeIndex(callPath, stmt)+1].(type) {
+		switch callPath[slices.Index(callPath, ast.Node(stmt))+1].(type) {
 		case *ast.LabeledStmt,
 			*ast.BlockStmt,
 			*ast.CaseClause,
@@ -2775,7 +2776,7 @@ func consistentOffsets(caller *Caller) bool {
 // ancestor of the CallExpr identified by its PathEnclosingInterval).
 func needsParens(callPath []ast.Node, old, new ast.Node) bool {
 	// Find enclosing old node and its parent.
-	i := nodeIndex(callPath, old)
+	i := slices.Index(callPath, old)
 	if i == -1 {
 		panic("not found")
 	}
@@ -2837,16 +2838,6 @@ func needsParens(callPath []ast.Node, old, new ast.Node) bool {
 	return false
 }
 
-func nodeIndex(nodes []ast.Node, n ast.Node) int {
-	// TODO(adonovan): Use index[ast.Node]() in go1.20.
-	for i, node := range nodes {
-		if node == n {
-			return i
-		}
-	}
-	return -1
-}
-
 // declares returns the set of lexical names declared by a
 // sequence of statements from the same block, excluding sub-blocks.
 // (Lexical names do not include control labels.)

internal/tokeninternal/tokeninternal.go

@@ -11,41 +11,10 @@ import (
 	"go/token"
 	"sort"
 	"sync"
+	"sync/atomic"
 	"unsafe"
 )
 
-// GetLines returns the table of line-start offsets from a token.File.
-func GetLines(file *token.File) []int {
-	// token.File has a Lines method on Go 1.21 and later.
-	if file, ok := (interface{})(file).(interface{ Lines() []int }); ok {
-		return file.Lines()
-	}
-
-	// This declaration must match that of token.File.
-	// This creates a risk of dependency skew.
-	// For now we check that the size of the two
-	// declarations is the same, on the (fragile) assumption
-	// that future changes would add fields.
-	type tokenFile119 struct {
-		_     string
-		_     int
-		_     int
-		mu    sync.Mutex // we're not complete monsters
-		lines []int
-		_     []struct{}
-	}
-
-	if unsafe.Sizeof(*file) != unsafe.Sizeof(tokenFile119{}) {
-		panic("unexpected token.File size")
-	}
-	var ptr *tokenFile119
-	type uP = unsafe.Pointer
-	*(*uP)(uP(&ptr)) = uP(file)
-	ptr.mu.Lock()
-	defer ptr.mu.Unlock()
-	return ptr.lines
-}
-
 // AddExistingFiles adds the specified files to the FileSet if they
 // are not already present. It panics if any pair of files in the
 // resulting FileSet would overlap.
@@ -56,7 +25,7 @@ func AddExistingFiles(fset *token.FileSet, files []*token.File) {
 		mutex sync.RWMutex
 		base  int
 		files []*token.File
-		_     *token.File // changed to atomic.Pointer[token.File] in go1.19
+		_     atomic.Pointer[token.File]
 	}
 
 	// If the size of token.FileSet changes, this will fail to compile.
@@ -116,8 +85,7 @@ func FileSetFor(files ...*token.File) *token.FileSet {
 	fset := token.NewFileSet()
 	for _, f := range files {
 		f2 := fset.AddFile(f.Name(), f.Base(), f.Size())
-		lines := GetLines(f)
-		f2.SetLines(lines)
+		f2.SetLines(f.Lines())
 	}
 	return fset
 }

internal/versions/toolchain.go

@@ -1,14 +0,0 @@
-// Copyright 2024 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-package versions
-
-// toolchain is maximum version (<1.22) that the go toolchain used
-// to build the current tool is known to support.
-//
-// When a tool is built with >=1.22, the value of toolchain is unused.
-//
-// x/tools does not support building with go <1.18. So we take this
-// as the minimum possible maximum.
-var toolchain string = Go1_18

internal/versions/toolchain_go119.go

@@ -1,14 +0,0 @@
-// Copyright 2024 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.19
-// +build go1.19
-
-package versions
-
-func init() {
-	if Compare(toolchain, Go1_19) < 0 {
-		toolchain = Go1_19
-	}
-}

internal/versions/toolchain_go120.go

@@ -1,14 +0,0 @@
-// Copyright 2024 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.20
-// +build go1.20
-
-package versions
-
-func init() {
-	if Compare(toolchain, Go1_20) < 0 {
-		toolchain = Go1_20
-	}
-}

internal/versions/toolchain_go121.go

@@ -1,14 +0,0 @@
-// Copyright 2024 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.21
-// +build go1.21
-
-package versions
-
-func init() {
-	if Compare(toolchain, Go1_21) < 0 {
-		toolchain = Go1_21
-	}
-}

internal/versions/types.go

@@ -5,15 +5,34 @@
 package versions
 
 import (
+	"go/ast"
 	"go/types"
 )
 
-// GoVersion returns the Go version of the type package.
-// It returns zero if no version can be determined.
-func GoVersion(pkg *types.Package) string {
-	// TODO(taking): x/tools can call GoVersion() [from 1.21] after 1.25.
-	if pkg, ok := any(pkg).(interface{ GoVersion() string }); ok {
-		return pkg.GoVersion()
+// FileVersion returns a file's Go version.
+// The reported version is an unknown Future version if a
+// version cannot be determined.
+func FileVersion(info *types.Info, file *ast.File) string {
+	// In tools built with Go >= 1.22, the Go version of a file
+	// follow a cascades of sources:
+	// 1) types.Info.FileVersion, which follows the cascade:
+	//   1.a) file version (ast.File.GoVersion),
+	//   1.b) the package version (types.Config.GoVersion), or
+	// 2) is some unknown Future version.
+	//
+	// File versions require a valid package version to be provided to types
+	// in Config.GoVersion. Config.GoVersion is either from the package's module
+	// or the toolchain (go run). This value should be provided by go/packages
+	// or unitchecker.Config.GoVersion.
+	if v := info.FileVersions[file]; IsValid(v) {
+		return v
 	}
-	return ""
+	// Note: we could instead return runtime.Version() [if valid].
+	// This would act as a max version on what a tool can support.
+	return Future
+}
+
+// InitFileVersions initializes info to record Go versions for Go files.
+func InitFileVersions(info *types.Info) {
+	info.FileVersions = make(map[*ast.File]string)
 }

internal/versions/types_go121.go

@@ -1,30 +0,0 @@
-// Copyright 2023 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build !go1.22
-// +build !go1.22
-
-package versions
-
-import (
-	"go/ast"
-	"go/types"
-)
-
-// FileVersion returns a language version (<=1.21) derived from runtime.Version()
-// or an unknown future version.
-func FileVersion(info *types.Info, file *ast.File) string {
-	// In x/tools built with Go <= 1.21, we do not have Info.FileVersions
-	// available. We use a go version derived from the toolchain used to
-	// compile the tool by default.
-	// This will be <= go1.21. We take this as the maximum version that
-	// this tool can support.
-	//
-	// There are no features currently in x/tools that need to tell fine grained
-	// differences for versions <1.22.
-	return toolchain
-}
-
-// InitFileVersions is a noop when compiled with this Go version.
-func InitFileVersions(*types.Info) {}

internal/versions/types_go122.go

@@ -1,41 +0,0 @@
-// Copyright 2023 The Go Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style
-// license that can be found in the LICENSE file.
-
-//go:build go1.22
-// +build go1.22
-
-package versions
-
-import (
-	"go/ast"
-	"go/types"
-)
-
-// FileVersion returns a file's Go version.
-// The reported version is an unknown Future version if a
-// version cannot be determined.
-func FileVersion(info *types.Info, file *ast.File) string {
-	// In tools built with Go >= 1.22, the Go version of a file
-	// follow a cascades of sources:
-	// 1) types.Info.FileVersion, which follows the cascade:
-	//   1.a) file version (ast.File.GoVersion),
-	//   1.b) the package version (types.Config.GoVersion), or
-	// 2) is some unknown Future version.
-	//
-	// File versions require a valid package version to be provided to types
-	// in Config.GoVersion. Config.GoVersion is either from the package's module
-	// or the toolchain (go run). This value should be provided by go/packages
-	// or unitchecker.Config.GoVersion.
-	if v := info.FileVersions[file]; IsValid(v) {
-		return v
-	}
-	// Note: we could instead return runtime.Version() [if valid].
-	// This would act as a max version on what a tool can support.
-	return Future
-}
-
-// InitFileVersions initializes info to record Go versions for Go files.
-func InitFileVersions(info *types.Info) {
-	info.FileVersions = make(map[*ast.File]string)
-}

internal/versions/types_test.go

@@ -13,13 +13,10 @@ import (
 	"go/types"
 	"testing"
 
-	"golang.org/x/tools/internal/testenv"
 	"golang.org/x/tools/internal/versions"
 )
 
 func Test(t *testing.T) {
-	testenv.NeedsGo1Point(t, 22)
-
 	var contents = map[string]string{
 		"gobuild.go": `
 	//go:build go1.23
@@ -49,7 +46,7 @@ func Test(t *testing.T) {
 				files[i] = parse(t, fset, test.fname, contents[test.fname])
 			}
 			pkg, info := typeCheck(t, fset, files, item.goversion)
-			if got, want := versions.GoVersion(pkg), item.pversion; versions.Compare(got, want) != 0 {
+			if got, want := pkg.GoVersion(), item.pversion; versions.Compare(got, want) != 0 {
 				t.Errorf("GoVersion()=%q. expected %q", got, want)
 			}
 			if got := versions.FileVersion(info, nil); got != "" {

internal/versions/versions_test.go

@@ -11,7 +11,6 @@ import (
 	"go/types"
 	"testing"
 
-	"golang.org/x/tools/internal/testenv"
 	"golang.org/x/tools/internal/versions"
 )
 
@@ -192,9 +191,7 @@ func TestBefore(t *testing.T) {
 	}
 }
 
-func TestFileVersions122(t *testing.T) {
-	testenv.NeedsGo1Point(t, 22)
-
+func TestFileVersions(t *testing.T) {
 	const source = `
 	package P
 	`
@@ -230,27 +227,3 @@ func TestFileVersions122(t *testing.T) {
 		}
 	}
 }
-
-func TestFileVersions121(t *testing.T) {
-	testenv.SkipAfterGo1Point(t, 21)
-
-	// If <1.22, info and file are ignored.
-	v := versions.FileVersion(nil, nil)
-	oneof := map[string]bool{
-		versions.Go1_18: true,
-		versions.Go1_19: true,
-		versions.Go1_20: true,
-		versions.Go1_21: true,
-	}
-	if !oneof[v] {
-		t.Errorf("FileVersion(...)=%q expected to be a known go version <1.22", v)
-	}
-
-	if versions.AtLeast(v, versions.Go1_22) {
-		t.Errorf("versions.AtLeast(%q, %q) expected to be false", v, versions.Go1_22)
-	}
-
-	if !versions.Before(v, versions.Go1_22) {
-		t.Errorf("versions.Before(%q, %q) expected to hold", v, versions.Go1_22)
-	}
-}