go/internal/gcimporter/gcimporter_test.go - tools - Git at Google

 // Copyright 2011 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.

 // This file is a copy of $GOROOT/src/go/internal/gcimporter/gcimporter_test.go,
 // adjusted to make it build with code from (std lib) internal/testenv copied.

 package gcimporter

 import (
 	"bytes"
 	"fmt"
 	"go/build"
 	"go/constant"
 	"go/types"
 	"io/ioutil"
 	"os"
 	"os/exec"
 	"path/filepath"
 	"runtime"
 	"strings"
 	"testing"
 	"time"

 	"golang.org/x/tools/internal/testenv"
 )

 func TestMain(m *testing.M) {
 	testenv.ExitIfSmallMachine()
 	os.Exit(m.Run())
 }

 // ----------------------------------------------------------------------------

 func needsCompiler(t *testing.T, compiler string) {
 	if runtime.Compiler == compiler {
 		return
 	}
 	switch compiler {
 	case "gc":
 		t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
 	}
 }

 // compile runs the compiler on filename, with dirname as the working directory,
 // and writes the output file to outdirname.
 func compile(t *testing.T, dirname, filename, outdirname string) string {
 	testenv.NeedsGoBuild(t)

 	// filename must end with ".go"
 	if !strings.HasSuffix(filename, ".go") {
 		t.Fatalf("filename doesn't end in .go: %s", filename)
 	}
 	basename := filepath.Base(filename)
 	outname := filepath.Join(outdirname, basename[:len(basename)-2]+"o")
 	cmd := exec.Command("go", "tool", "compile", "-p=p", "-o", outname, filename)
 	cmd.Dir = dirname
 	out, err := cmd.CombinedOutput()
 	if err != nil {
 		t.Logf("%s", out)
 		t.Fatalf("go tool compile %s failed: %s", filename, err)
 	}
 	return outname
 }

 func testPath(t *testing.T, path, srcDir string) *types.Package {
 	t0 := time.Now()
 	pkg, err := Import(make(map[string]*types.Package), path, srcDir, nil)
 	if err != nil {
 		t.Errorf("testPath(%s): %s", path, err)
 		return nil
 	}
 	t.Logf("testPath(%s): %v", path, time.Since(t0))
 	return pkg
 }

 const maxTime = 30 * time.Second

 func testDir(t *testing.T, dir string, endTime time.Time) (nimports int) {
 	dirname := filepath.Join(runtime.GOROOT(), "pkg", runtime.GOOS+"_"+runtime.GOARCH, dir)
 	list, err := ioutil.ReadDir(dirname)
 	if err != nil {
 		t.Fatalf("testDir(%s): %s", dirname, err)
 	}
 	for _, f := range list {
 		if time.Now().After(endTime) {
 			t.Log("testing time used up")
 			return
 		}
 		switch {
 		case !f.IsDir():
 			// try extensions
 			for _, ext := range pkgExts {
 				if strings.HasSuffix(f.Name(), ext) {
 					name := f.Name()[0 : len(f.Name())-len(ext)] // remove extension
 					if testPath(t, filepath.Join(dir, name), dir) != nil {
 						nimports++
 					}
 				}
 			}
 		case f.IsDir():
 			nimports += testDir(t, filepath.Join(dir, f.Name()), endTime)
 		}
 	}
 	return
 }

 func mktmpdir(t *testing.T) string {
 	tmpdir, err := ioutil.TempDir("", "gcimporter_test")
 	if err != nil {
 		t.Fatal("mktmpdir:", err)
 	}
 	if err := os.Mkdir(filepath.Join(tmpdir, "testdata"), 0700); err != nil {
 		os.RemoveAll(tmpdir)
 		t.Fatal("mktmpdir:", err)
 	}
 	return tmpdir
 }

 const testfile = "exports.go"

 func TestImportTestdata(t *testing.T) {
 	needsCompiler(t, "gc")

 	tmpdir := mktmpdir(t)
 	defer os.RemoveAll(tmpdir)

 	compile(t, "testdata", testfile, filepath.Join(tmpdir, "testdata"))

 	// filename should end with ".go"
 	filename := testfile[:len(testfile)-3]
 	if pkg := testPath(t, "./testdata/"+filename, tmpdir); pkg != nil {
 		// The package's Imports list must include all packages
 		// explicitly imported by testfile, plus all packages
 		// referenced indirectly via exported objects in testfile.
 		// With the textual export format (when run against Go1.6),
 		// the list may also include additional packages that are
 		// not strictly required for import processing alone (they
 		// are exported to err "on the safe side").
 		// For now, we just test the presence of a few packages
 		// that we know are there for sure.
 		got := fmt.Sprint(pkg.Imports())
 		for _, want := range []string{"go/ast", "go/token"} {
 			if !strings.Contains(got, want) {
 				t.Errorf(`Package("exports").Imports() = %s, does not contain %s`, got, want)
 			}
 		}
 	}
 }

 func TestVersionHandling(t *testing.T) {
 	if debug {
 		t.Skip("TestVersionHandling panics in debug mode")
 	}

 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	const dir = "./testdata/versions"
 	list, err := ioutil.ReadDir(dir)
 	if err != nil {
 		t.Fatal(err)
 	}

 	tmpdir := mktmpdir(t)
 	defer os.RemoveAll(tmpdir)
 	corruptdir := filepath.Join(tmpdir, "testdata", "versions")
 	if err := os.Mkdir(corruptdir, 0700); err != nil {
 		t.Fatal(err)
 	}

 	for _, f := range list {
 		name := f.Name()
 		if !strings.HasSuffix(name, ".a") {
 			continue // not a package file
 		}
 		if strings.Contains(name, "corrupted") {
 			continue // don't process a leftover corrupted file
 		}
 		pkgpath := "./" + name[:len(name)-2]

 		if testing.Verbose() {
 			t.Logf("importing %s", name)
 		}

 		// test that export data can be imported
 		_, err := Import(make(map[string]*types.Package), pkgpath, dir, nil)
 		if err != nil {
 			// ok to fail if it fails with a newer version error for select files
 			if strings.Contains(err.Error(), "newer version") {
 				switch name {
 				case "test_go1.11_999b.a", "test_go1.11_999i.a":
 					continue
 				}
 				// fall through
 			}
 			t.Errorf("import %q failed: %v", pkgpath, err)
 			continue
 		}

 		// create file with corrupted export data
 		// 1) read file
 		data, err := ioutil.ReadFile(filepath.Join(dir, name))
 		if err != nil {
 			t.Fatal(err)
 		}
 		// 2) find export data
 		i := bytes.Index(data, []byte("\n$$B\n")) + 5
 		j := bytes.Index(data[i:], []byte("\n$$\n")) + i
 		if i < 0 || j < 0 || i > j {
 			t.Fatalf("export data section not found (i = %d, j = %d)", i, j)
 		}
 		// 3) corrupt the data (increment every 7th byte)
 		for k := j - 13; k >= i; k -= 7 {
 			data[k]++
 		}
 		// 4) write the file
 		pkgpath += "_corrupted"
 		filename := filepath.Join(corruptdir, pkgpath) + ".a"
 		ioutil.WriteFile(filename, data, 0666)

 		// test that importing the corrupted file results in an error
 		_, err = Import(make(map[string]*types.Package), pkgpath, corruptdir, nil)
 		if err == nil {
 			t.Errorf("import corrupted %q succeeded", pkgpath)
 		} else if msg := err.Error(); !strings.Contains(msg, "version skew") {
 			t.Errorf("import %q error incorrect (%s)", pkgpath, msg)
 		}
 	}
 }

 func TestImportStdLib(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	dt := maxTime
 	if testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
 		dt = 10 * time.Millisecond
 	}
 	nimports := testDir(t, "", time.Now().Add(dt)) // installed packages
 	t.Logf("tested %d imports", nimports)
 }

 var importedObjectTests = []struct {
 	name string
 	want string
 }{
 	// non-interfaces
 	{"crypto.Hash", "type Hash uint"},
 	{"go/ast.ObjKind", "type ObjKind int"},
 	{"go/types.Qualifier", "type Qualifier func(*Package) string"},
 	{"go/types.Comparable", "func Comparable(T Type) bool"},
 	{"math.Pi", "const Pi untyped float"},
 	{"math.Sin", "func Sin(x float64) float64"},
 	{"go/ast.NotNilFilter", "func NotNilFilter(_ string, v reflect.Value) bool"},
 	{"go/internal/gcimporter.FindPkg", "func FindPkg(path string, srcDir string) (filename string, id string)"},

 	// interfaces
 	{"context.Context", "type Context interface{Deadline() (deadline time.Time, ok bool); Done() <-chan struct{}; Err() error; Value(key any) any}"},
 	{"crypto.Decrypter", "type Decrypter interface{Decrypt(rand io.Reader, msg []byte, opts DecrypterOpts) (plaintext []byte, err error); Public() PublicKey}"},
 	{"encoding.BinaryMarshaler", "type BinaryMarshaler interface{MarshalBinary() (data []byte, err error)}"},
 	{"io.Reader", "type Reader interface{Read(p []byte) (n int, err error)}"},
 	{"io.ReadWriter", "type ReadWriter interface{Reader; Writer}"},
 	{"go/ast.Node", "type Node interface{End() go/token.Pos; Pos() go/token.Pos}"},
 	{"go/types.Type", "type Type interface{String() string; Underlying() Type}"},
 }

 // TODO(rsc): Delete this init func after x/tools no longer needs to test successfully with Go 1.17.
 func init() {
 	if build.Default.ReleaseTags[len(build.Default.ReleaseTags)-1] <= "go1.17" {
 		for i := range importedObjectTests {
 			if importedObjectTests[i].name == "context.Context" {
 				// Expand any to interface{}.
 				importedObjectTests[i].want = "type Context interface{Deadline() (deadline time.Time, ok bool); Done() <-chan struct{}; Err() error; Value(key interface{}) interface{}}"
 			}
 		}
 	}
 }

 func TestImportedTypes(t *testing.T) {
 	testenv.NeedsGo1Point(t, 11)
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	for _, test := range importedObjectTests {
 		obj := importObject(t, test.name)
 		if obj == nil {
 			continue // error reported elsewhere
 		}
 		got := types.ObjectString(obj, types.RelativeTo(obj.Pkg()))

 		// TODO(rsc): Delete this block once go.dev/cl/368254 lands.
 		if got != test.want && test.want == strings.ReplaceAll(got, "interface{}", "any") {
 			got = test.want
 		}

 		if got != test.want {
 			t.Errorf("%s: got %q; want %q", test.name, got, test.want)
 		}

 		if named, _ := obj.Type().(*types.Named); named != nil {
 			verifyInterfaceMethodRecvs(t, named, 0)
 		}
 	}
 }

 func TestImportedConsts(t *testing.T) {
 	testenv.NeedsGo1Point(t, 11)
 	tests := []struct {
 		name string
 		want constant.Kind
 	}{
 		{"math.Pi", constant.Float},
 		{"math.MaxFloat64", constant.Float},
 		{"math.MaxInt64", constant.Int},
 	}

 	for _, test := range tests {
 		obj := importObject(t, test.name)
 		if got := obj.(*types.Const).Val().Kind(); got != test.want {
 			t.Errorf("%s: imported as constant.Kind(%v), want constant.Kind(%v)", test.name, got, test.want)
 		}
 	}
 }

 // importObject imports the object specified by a name of the form
 // <import path>.<object name>, e.g. go/types.Type.
 //
 // If any errors occur they are reported via t and the resulting object will
 // be nil.
 func importObject(t *testing.T, name string) types.Object {
 	s := strings.Split(name, ".")
 	if len(s) != 2 {
 		t.Fatal("inconsistent test data")
 	}
 	importPath := s[0]
 	objName := s[1]

 	pkg, err := Import(make(map[string]*types.Package), importPath, ".", nil)
 	if err != nil {
 		t.Error(err)
 		return nil
 	}

 	obj := pkg.Scope().Lookup(objName)
 	if obj == nil {
 		t.Errorf("%s: object not found", name)
 		return nil
 	}
 	return obj
 }

 // verifyInterfaceMethodRecvs verifies that method receiver types
 // are named if the methods belong to a named interface type.
 func verifyInterfaceMethodRecvs(t *testing.T, named *types.Named, level int) {
 	// avoid endless recursion in case of an embedding bug that lead to a cycle
 	if level > 10 {
 		t.Errorf("%s: embeds itself", named)
 		return
 	}

 	iface, _ := named.Underlying().(*types.Interface)
 	if iface == nil {
 		return // not an interface
 	}

 	// check explicitly declared methods
 	for i := 0; i < iface.NumExplicitMethods(); i++ {
 		m := iface.ExplicitMethod(i)
 		recv := m.Type().(*types.Signature).Recv()
 		if recv == nil {
 			t.Errorf("%s: missing receiver type", m)
 			continue
 		}
 		if recv.Type() != named {
 			t.Errorf("%s: got recv type %s; want %s", m, recv.Type(), named)
 		}
 	}

 	// check embedded interfaces (if they are named, too)
 	for i := 0; i < iface.NumEmbeddeds(); i++ {
 		// embedding of interfaces cannot have cycles; recursion will terminate
 		if etype, _ := iface.EmbeddedType(i).(*types.Named); etype != nil {
 			verifyInterfaceMethodRecvs(t, etype, level+1)
 		}
 	}
 }

 func TestIssue5815(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	pkg := importPkg(t, "strings", ".")

 	scope := pkg.Scope()
 	for _, name := range scope.Names() {
 		obj := scope.Lookup(name)
 		if obj.Pkg() == nil {
 			t.Errorf("no pkg for %s", obj)
 		}
 		if tname, _ := obj.(*types.TypeName); tname != nil {
 			named := tname.Type().(*types.Named)
 			for i := 0; i < named.NumMethods(); i++ {
 				m := named.Method(i)
 				if m.Pkg() == nil {
 					t.Errorf("no pkg for %s", m)
 				}
 			}
 		}
 	}
 }

 // Smoke test to ensure that imported methods get the correct package.
 func TestCorrectMethodPackage(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	imports := make(map[string]*types.Package)
 	_, err := Import(imports, "net/http", ".", nil)
 	if err != nil {
 		t.Fatal(err)
 	}

 	mutex := imports["sync"].Scope().Lookup("Mutex").(*types.TypeName).Type()
 	mset := types.NewMethodSet(types.NewPointer(mutex)) // methods of *sync.Mutex
 	sel := mset.Lookup(nil, "Lock")
 	lock := sel.Obj().(*types.Func)
 	if got, want := lock.Pkg().Path(), "sync"; got != want {
 		t.Errorf("got package path %q; want %q", got, want)
 	}
 }

 func TestIssue13566(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	// On windows, we have to set the -D option for the compiler to avoid having a drive
 	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
 	if runtime.GOOS == "windows" {
 		t.Skip("avoid dealing with relative paths/drive letters on windows")
 	}

 	tmpdir := mktmpdir(t)
 	defer os.RemoveAll(tmpdir)
 	testoutdir := filepath.Join(tmpdir, "testdata")

 	// b.go needs to be compiled from the output directory so that the compiler can
 	// find the compiled package a. We pass the full path to compile() so that we
 	// don't have to copy the file to that directory.
 	bpath, err := filepath.Abs(filepath.Join("testdata", "b.go"))
 	if err != nil {
 		t.Fatal(err)
 	}
 	compile(t, "testdata", "a.go", testoutdir)
 	compile(t, testoutdir, bpath, testoutdir)

 	// import must succeed (test for issue at hand)
 	pkg := importPkg(t, "./testdata/b", tmpdir)

 	// make sure all indirectly imported packages have names
 	for _, imp := range pkg.Imports() {
 		if imp.Name() == "" {
 			t.Errorf("no name for %s package", imp.Path())
 		}
 	}
 }

 func TestIssue13898(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	// import go/internal/gcimporter which imports go/types partially
 	imports := make(map[string]*types.Package)
 	_, err := Import(imports, "go/internal/gcimporter", ".", nil)
 	if err != nil {
 		t.Fatal(err)
 	}

 	// look for go/types package
 	var goTypesPkg *types.Package
 	for path, pkg := range imports {
 		if path == "go/types" {
 			goTypesPkg = pkg
 			break
 		}
 	}
 	if goTypesPkg == nil {
 		t.Fatal("go/types not found")
 	}

 	// look for go/types.Object type
 	obj := lookupObj(t, goTypesPkg.Scope(), "Object")
 	typ, ok := obj.Type().(*types.Named)
 	if !ok {
 		t.Fatalf("go/types.Object type is %v; wanted named type", typ)
 	}

 	// lookup go/types.Object.Pkg method
 	m, index, indirect := types.LookupFieldOrMethod(typ, false, nil, "Pkg")
 	if m == nil {
 		t.Fatalf("go/types.Object.Pkg not found (index = %v, indirect = %v)", index, indirect)
 	}

 	// the method must belong to go/types
 	if m.Pkg().Path() != "go/types" {
 		t.Fatalf("found %v; want go/types", m.Pkg())
 	}
 }

 func TestIssue15517(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	// On windows, we have to set the -D option for the compiler to avoid having a drive
 	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
 	if runtime.GOOS == "windows" {
 		t.Skip("avoid dealing with relative paths/drive letters on windows")
 	}

 	tmpdir := mktmpdir(t)
 	defer os.RemoveAll(tmpdir)

 	compile(t, "testdata", "p.go", filepath.Join(tmpdir, "testdata"))

 	// Multiple imports of p must succeed without redeclaration errors.
 	// We use an import path that's not cleaned up so that the eventual
 	// file path for the package is different from the package path; this
 	// will expose the error if it is present.
 	//
 	// (Issue: Both the textual and the binary importer used the file path
 	// of the package to be imported as key into the shared packages map.
 	// However, the binary importer then used the package path to identify
 	// the imported package to mark it as complete; effectively marking the
 	// wrong package as complete. By using an "unclean" package path, the
 	// file and package path are different, exposing the problem if present.
 	// The same issue occurs with vendoring.)
 	imports := make(map[string]*types.Package)
 	for i := 0; i < 3; i++ {
 		if _, err := Import(imports, "./././testdata/p", tmpdir, nil); err != nil {
 			t.Fatal(err)
 		}
 	}
 }

 func TestIssue15920(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	// On windows, we have to set the -D option for the compiler to avoid having a drive
 	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
 	if runtime.GOOS == "windows" {
 		t.Skip("avoid dealing with relative paths/drive letters on windows")
 	}

 	compileAndImportPkg(t, "issue15920")
 }

 func TestIssue20046(t *testing.T) {
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	// On windows, we have to set the -D option for the compiler to avoid having a drive
 	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
 	if runtime.GOOS == "windows" {
 		t.Skip("avoid dealing with relative paths/drive letters on windows")
 	}

 	// "./issue20046".V.M must exist
 	pkg := compileAndImportPkg(t, "issue20046")
 	obj := lookupObj(t, pkg.Scope(), "V")
 	if m, index, indirect := types.LookupFieldOrMethod(obj.Type(), false, nil, "M"); m == nil {
 		t.Fatalf("V.M not found (index = %v, indirect = %v)", index, indirect)
 	}
 }

 func TestIssue25301(t *testing.T) {
 	testenv.NeedsGo1Point(t, 11)
 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	// On windows, we have to set the -D option for the compiler to avoid having a drive
 	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
 	if runtime.GOOS == "windows" {
 		t.Skip("avoid dealing with relative paths/drive letters on windows")
 	}

 	compileAndImportPkg(t, "issue25301")
 }

 func TestIssue51836(t *testing.T) {
 	testenv.NeedsGo1Point(t, 18) // requires generics

 	// This package only handles gc export data.
 	needsCompiler(t, "gc")

 	// On windows, we have to set the -D option for the compiler to avoid having a drive
 	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
 	if runtime.GOOS == "windows" {
 		t.Skip("avoid dealing with relative paths/drive letters on windows")
 	}

 	tmpdir := mktmpdir(t)
 	defer os.RemoveAll(tmpdir)
 	testoutdir := filepath.Join(tmpdir, "testdata")

 	dir := filepath.Join("testdata", "issue51836")
 	// Following the pattern of TestIssue13898, aa.go needs to be compiled from
 	// the output directory. We pass the full path to compile() so that we don't
 	// have to copy the file to that directory.
 	bpath, err := filepath.Abs(filepath.Join(dir, "aa.go"))
 	if err != nil {
 		t.Fatal(err)
 	}
 	compile(t, dir, "a.go", testoutdir)
 	compile(t, testoutdir, bpath, testoutdir)

 	// import must succeed (test for issue at hand)
 	_ = importPkg(t, "./testdata/aa", tmpdir)
 }

 func importPkg(t *testing.T, path, srcDir string) *types.Package {
 	pkg, err := Import(make(map[string]*types.Package), path, srcDir, nil)
 	if err != nil {
 		t.Fatal(err)
 	}
 	return pkg
 }

 func compileAndImportPkg(t *testing.T, name string) *types.Package {
 	tmpdir := mktmpdir(t)
 	defer os.RemoveAll(tmpdir)
 	compile(t, "testdata", name+".go", filepath.Join(tmpdir, "testdata"))
 	return importPkg(t, "./testdata/"+name, tmpdir)
 }

 func lookupObj(t *testing.T, scope *types.Scope, name string) types.Object {
 	if obj := scope.Lookup(name); obj != nil {
 		return obj
 	}
 	t.Fatalf("%s not found", name)
 	return nil
 }
	// Copyright 2011 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.

	// This file is a copy of $GOROOT/src/go/internal/gcimporter/gcimporter_test.go,
	// adjusted to make it build with code from (std lib) internal/testenv copied.

	package gcimporter

	import (
	"bytes"
	"fmt"
	"go/build"
	"go/constant"
	"go/types"
	"io/ioutil"
	"os"
	"os/exec"
	"path/filepath"
	"runtime"
	"strings"
	"testing"
	"time"

	"golang.org/x/tools/internal/testenv"
	)

	func TestMain(m *testing.M) {
	testenv.ExitIfSmallMachine()
	os.Exit(m.Run())
	}

	// ----------------------------------------------------------------------------

	func needsCompiler(t *testing.T, compiler string) {
	if runtime.Compiler == compiler {
	return
	}
	switch compiler {
	case "gc":
	t.Skipf("gc-built packages not available (compiler = %s)", runtime.Compiler)
	}
	}

	// compile runs the compiler on filename, with dirname as the working directory,
	// and writes the output file to outdirname.
	func compile(t *testing.T, dirname, filename, outdirname string) string {
	testenv.NeedsGoBuild(t)

	// filename must end with ".go"
	if !strings.HasSuffix(filename, ".go") {
	t.Fatalf("filename doesn't end in .go: %s", filename)
	}
	basename := filepath.Base(filename)
	outname := filepath.Join(outdirname, basename[:len(basename)-2]+"o")
	cmd := exec.Command("go", "tool", "compile", "-p=p", "-o", outname, filename)
	cmd.Dir = dirname
	out, err := cmd.CombinedOutput()
	if err != nil {
	t.Logf("%s", out)
	t.Fatalf("go tool compile %s failed: %s", filename, err)
	}
	return outname
	}

	func testPath(t testing.T, path, srcDir string) types.Package {
	t0 := time.Now()
	pkg, err := Import(make(map[string]*types.Package), path, srcDir, nil)
	if err != nil {
	t.Errorf("testPath(%s): %s", path, err)
	return nil
	}
	t.Logf("testPath(%s): %v", path, time.Since(t0))
	return pkg
	}

	const maxTime = 30 * time.Second

	func testDir(t *testing.T, dir string, endTime time.Time) (nimports int) {
	dirname := filepath.Join(runtime.GOROOT(), "pkg", runtime.GOOS+"_"+runtime.GOARCH, dir)
	list, err := ioutil.ReadDir(dirname)
	if err != nil {
	t.Fatalf("testDir(%s): %s", dirname, err)
	}
	for _, f := range list {
	if time.Now().After(endTime) {
	t.Log("testing time used up")
	return
	}
	switch {
	case !f.IsDir():
	// try extensions
	for _, ext := range pkgExts {
	if strings.HasSuffix(f.Name(), ext) {
	name := f.Name()[0 : len(f.Name())-len(ext)] // remove extension
	if testPath(t, filepath.Join(dir, name), dir) != nil {
	nimports++
	}
	}
	}
	case f.IsDir():
	nimports += testDir(t, filepath.Join(dir, f.Name()), endTime)
	}
	}
	return
	}

	func mktmpdir(t *testing.T) string {
	tmpdir, err := ioutil.TempDir("", "gcimporter_test")
	if err != nil {
	t.Fatal("mktmpdir:", err)
	}
	if err := os.Mkdir(filepath.Join(tmpdir, "testdata"), 0700); err != nil {
	os.RemoveAll(tmpdir)
	t.Fatal("mktmpdir:", err)
	}
	return tmpdir
	}

	const testfile = "exports.go"

	func TestImportTestdata(t *testing.T) {
	needsCompiler(t, "gc")

	tmpdir := mktmpdir(t)
	defer os.RemoveAll(tmpdir)

	compile(t, "testdata", testfile, filepath.Join(tmpdir, "testdata"))

	// filename should end with ".go"
	filename := testfile[:len(testfile)-3]
	if pkg := testPath(t, "./testdata/"+filename, tmpdir); pkg != nil {
	// The package's Imports list must include all packages
	// explicitly imported by testfile, plus all packages
	// referenced indirectly via exported objects in testfile.
	// With the textual export format (when run against Go1.6),
	// the list may also include additional packages that are
	// not strictly required for import processing alone (they
	// are exported to err "on the safe side").
	// For now, we just test the presence of a few packages
	// that we know are there for sure.
	got := fmt.Sprint(pkg.Imports())
	for _, want := range []string{"go/ast", "go/token"} {
	if !strings.Contains(got, want) {
	t.Errorf(`Package("exports").Imports() = %s, does not contain %s`, got, want)
	}
	}
	}
	}

	func TestVersionHandling(t *testing.T) {
	if debug {
	t.Skip("TestVersionHandling panics in debug mode")
	}

	// This package only handles gc export data.
	needsCompiler(t, "gc")

	const dir = "./testdata/versions"
	list, err := ioutil.ReadDir(dir)
	if err != nil {
	t.Fatal(err)
	}

	tmpdir := mktmpdir(t)
	defer os.RemoveAll(tmpdir)
	corruptdir := filepath.Join(tmpdir, "testdata", "versions")
	if err := os.Mkdir(corruptdir, 0700); err != nil {
	t.Fatal(err)
	}

	for _, f := range list {
	name := f.Name()
	if !strings.HasSuffix(name, ".a") {
	continue // not a package file
	}
	if strings.Contains(name, "corrupted") {
	continue // don't process a leftover corrupted file
	}
	pkgpath := "./" + name[:len(name)-2]

	if testing.Verbose() {
	t.Logf("importing %s", name)
	}

	// test that export data can be imported
	_, err := Import(make(map[string]*types.Package), pkgpath, dir, nil)
	if err != nil {
	// ok to fail if it fails with a newer version error for select files
	if strings.Contains(err.Error(), "newer version") {
	switch name {
	case "test_go1.11_999b.a", "test_go1.11_999i.a":
	continue
	}
	// fall through
	}
	t.Errorf("import %q failed: %v", pkgpath, err)
	continue
	}

	// create file with corrupted export data
	// 1) read file
	data, err := ioutil.ReadFile(filepath.Join(dir, name))
	if err != nil {
	t.Fatal(err)
	}
	// 2) find export data
	i := bytes.Index(data, []byte("\n$$B\n")) + 5
	j := bytes.Index(data[i:], []byte("\n$$\n")) + i
	if i < 0 \|\| j < 0 \|\| i > j {
	t.Fatalf("export data section not found (i = %d, j = %d)", i, j)
	}
	// 3) corrupt the data (increment every 7th byte)
	for k := j - 13; k >= i; k -= 7 {
	data[k]++
	}
	// 4) write the file
	pkgpath += "_corrupted"
	filename := filepath.Join(corruptdir, pkgpath) + ".a"
	ioutil.WriteFile(filename, data, 0666)

	// test that importing the corrupted file results in an error
	_, err = Import(make(map[string]*types.Package), pkgpath, corruptdir, nil)
	if err == nil {
	t.Errorf("import corrupted %q succeeded", pkgpath)
	} else if msg := err.Error(); !strings.Contains(msg, "version skew") {
	t.Errorf("import %q error incorrect (%s)", pkgpath, msg)
	}
	}
	}

	func TestImportStdLib(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	dt := maxTime
	if testing.Short() && os.Getenv("GO_BUILDER_NAME") == "" {
	dt = 10 * time.Millisecond
	}
	nimports := testDir(t, "", time.Now().Add(dt)) // installed packages
	t.Logf("tested %d imports", nimports)
	}

	var importedObjectTests = []struct {
	name string
	want string
	}{
	// non-interfaces
	{"crypto.Hash", "type Hash uint"},
	{"go/ast.ObjKind", "type ObjKind int"},
	{"go/types.Qualifier", "type Qualifier func(*Package) string"},
	{"go/types.Comparable", "func Comparable(T Type) bool"},
	{"math.Pi", "const Pi untyped float"},
	{"math.Sin", "func Sin(x float64) float64"},
	{"go/ast.NotNilFilter", "func NotNilFilter(_ string, v reflect.Value) bool"},
	{"go/internal/gcimporter.FindPkg", "func FindPkg(path string, srcDir string) (filename string, id string)"},

	// interfaces
	{"context.Context", "type Context interface{Deadline() (deadline time.Time, ok bool); Done() <-chan struct{}; Err() error; Value(key any) any}"},
	{"crypto.Decrypter", "type Decrypter interface{Decrypt(rand io.Reader, msg []byte, opts DecrypterOpts) (plaintext []byte, err error); Public() PublicKey}"},
	{"encoding.BinaryMarshaler", "type BinaryMarshaler interface{MarshalBinary() (data []byte, err error)}"},
	{"io.Reader", "type Reader interface{Read(p []byte) (n int, err error)}"},
	{"io.ReadWriter", "type ReadWriter interface{Reader; Writer}"},
	{"go/ast.Node", "type Node interface{End() go/token.Pos; Pos() go/token.Pos}"},
	{"go/types.Type", "type Type interface{String() string; Underlying() Type}"},
	}

	// TODO(rsc): Delete this init func after x/tools no longer needs to test successfully with Go 1.17.
	func init() {
	if build.Default.ReleaseTags[len(build.Default.ReleaseTags)-1] <= "go1.17" {
	for i := range importedObjectTests {
	if importedObjectTests[i].name == "context.Context" {
	// Expand any to interface{}.
	importedObjectTests[i].want = "type Context interface{Deadline() (deadline time.Time, ok bool); Done() <-chan struct{}; Err() error; Value(key interface{}) interface{}}"
	}
	}
	}
	}

	func TestImportedTypes(t *testing.T) {
	testenv.NeedsGo1Point(t, 11)
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	for _, test := range importedObjectTests {
	obj := importObject(t, test.name)
	if obj == nil {
	continue // error reported elsewhere
	}
	got := types.ObjectString(obj, types.RelativeTo(obj.Pkg()))

	// TODO(rsc): Delete this block once go.dev/cl/368254 lands.
	if got != test.want && test.want == strings.ReplaceAll(got, "interface{}", "any") {
	got = test.want
	}

	if got != test.want {
	t.Errorf("%s: got %q; want %q", test.name, got, test.want)
	}

	if named, _ := obj.Type().(*types.Named); named != nil {
	verifyInterfaceMethodRecvs(t, named, 0)
	}
	}
	}

	func TestImportedConsts(t *testing.T) {
	testenv.NeedsGo1Point(t, 11)
	tests := []struct {
	name string
	want constant.Kind
	}{
	{"math.Pi", constant.Float},
	{"math.MaxFloat64", constant.Float},
	{"math.MaxInt64", constant.Int},
	}

	for _, test := range tests {
	obj := importObject(t, test.name)
	if got := obj.(*types.Const).Val().Kind(); got != test.want {
	t.Errorf("%s: imported as constant.Kind(%v), want constant.Kind(%v)", test.name, got, test.want)
	}
	}
	}

	// importObject imports the object specified by a name of the form
	// <import path>.<object name>, e.g. go/types.Type.
	//
	// If any errors occur they are reported via t and the resulting object will
	// be nil.
	func importObject(t *testing.T, name string) types.Object {
	s := strings.Split(name, ".")
	if len(s) != 2 {
	t.Fatal("inconsistent test data")
	}
	importPath := s[0]
	objName := s[1]

	pkg, err := Import(make(map[string]*types.Package), importPath, ".", nil)
	if err != nil {
	t.Error(err)
	return nil
	}

	obj := pkg.Scope().Lookup(objName)
	if obj == nil {
	t.Errorf("%s: object not found", name)
	return nil
	}
	return obj
	}

	// verifyInterfaceMethodRecvs verifies that method receiver types
	// are named if the methods belong to a named interface type.
	func verifyInterfaceMethodRecvs(t testing.T, named types.Named, level int) {
	// avoid endless recursion in case of an embedding bug that lead to a cycle
	if level > 10 {
	t.Errorf("%s: embeds itself", named)
	return
	}

	iface, _ := named.Underlying().(*types.Interface)
	if iface == nil {
	return // not an interface
	}

	// check explicitly declared methods
	for i := 0; i < iface.NumExplicitMethods(); i++ {
	m := iface.ExplicitMethod(i)
	recv := m.Type().(*types.Signature).Recv()
	if recv == nil {
	t.Errorf("%s: missing receiver type", m)
	continue
	}
	if recv.Type() != named {
	t.Errorf("%s: got recv type %s; want %s", m, recv.Type(), named)
	}
	}

	// check embedded interfaces (if they are named, too)
	for i := 0; i < iface.NumEmbeddeds(); i++ {
	// embedding of interfaces cannot have cycles; recursion will terminate
	if etype, _ := iface.EmbeddedType(i).(*types.Named); etype != nil {
	verifyInterfaceMethodRecvs(t, etype, level+1)
	}
	}
	}

	func TestIssue5815(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	pkg := importPkg(t, "strings", ".")

	scope := pkg.Scope()
	for _, name := range scope.Names() {
	obj := scope.Lookup(name)
	if obj.Pkg() == nil {
	t.Errorf("no pkg for %s", obj)
	}
	if tname, _ := obj.(*types.TypeName); tname != nil {
	named := tname.Type().(*types.Named)
	for i := 0; i < named.NumMethods(); i++ {
	m := named.Method(i)
	if m.Pkg() == nil {
	t.Errorf("no pkg for %s", m)
	}
	}
	}
	}
	}

	// Smoke test to ensure that imported methods get the correct package.
	func TestCorrectMethodPackage(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	imports := make(map[string]*types.Package)
	_, err := Import(imports, "net/http", ".", nil)
	if err != nil {
	t.Fatal(err)
	}

	mutex := imports["sync"].Scope().Lookup("Mutex").(*types.TypeName).Type()
	mset := types.NewMethodSet(types.NewPointer(mutex)) // methods of *sync.Mutex
	sel := mset.Lookup(nil, "Lock")
	lock := sel.Obj().(*types.Func)
	if got, want := lock.Pkg().Path(), "sync"; got != want {
	t.Errorf("got package path %q; want %q", got, want)
	}
	}

	func TestIssue13566(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	// On windows, we have to set the -D option for the compiler to avoid having a drive
	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
	if runtime.GOOS == "windows" {
	t.Skip("avoid dealing with relative paths/drive letters on windows")
	}

	tmpdir := mktmpdir(t)
	defer os.RemoveAll(tmpdir)
	testoutdir := filepath.Join(tmpdir, "testdata")

	// b.go needs to be compiled from the output directory so that the compiler can
	// find the compiled package a. We pass the full path to compile() so that we
	// don't have to copy the file to that directory.
	bpath, err := filepath.Abs(filepath.Join("testdata", "b.go"))
	if err != nil {
	t.Fatal(err)
	}
	compile(t, "testdata", "a.go", testoutdir)
	compile(t, testoutdir, bpath, testoutdir)

	// import must succeed (test for issue at hand)
	pkg := importPkg(t, "./testdata/b", tmpdir)

	// make sure all indirectly imported packages have names
	for _, imp := range pkg.Imports() {
	if imp.Name() == "" {
	t.Errorf("no name for %s package", imp.Path())
	}
	}
	}

	func TestIssue13898(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	// import go/internal/gcimporter which imports go/types partially
	imports := make(map[string]*types.Package)
	_, err := Import(imports, "go/internal/gcimporter", ".", nil)
	if err != nil {
	t.Fatal(err)
	}

	// look for go/types package
	var goTypesPkg *types.Package
	for path, pkg := range imports {
	if path == "go/types" {
	goTypesPkg = pkg
	break
	}
	}
	if goTypesPkg == nil {
	t.Fatal("go/types not found")
	}

	// look for go/types.Object type
	obj := lookupObj(t, goTypesPkg.Scope(), "Object")
	typ, ok := obj.Type().(*types.Named)
	if !ok {
	t.Fatalf("go/types.Object type is %v; wanted named type", typ)
	}

	// lookup go/types.Object.Pkg method
	m, index, indirect := types.LookupFieldOrMethod(typ, false, nil, "Pkg")
	if m == nil {
	t.Fatalf("go/types.Object.Pkg not found (index = %v, indirect = %v)", index, indirect)
	}

	// the method must belong to go/types
	if m.Pkg().Path() != "go/types" {
	t.Fatalf("found %v; want go/types", m.Pkg())
	}
	}

	func TestIssue15517(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	// On windows, we have to set the -D option for the compiler to avoid having a drive
	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
	if runtime.GOOS == "windows" {
	t.Skip("avoid dealing with relative paths/drive letters on windows")
	}

	tmpdir := mktmpdir(t)
	defer os.RemoveAll(tmpdir)

	compile(t, "testdata", "p.go", filepath.Join(tmpdir, "testdata"))

	// Multiple imports of p must succeed without redeclaration errors.
	// We use an import path that's not cleaned up so that the eventual
	// file path for the package is different from the package path; this
	// will expose the error if it is present.
	//
	// (Issue: Both the textual and the binary importer used the file path
	// of the package to be imported as key into the shared packages map.
	// However, the binary importer then used the package path to identify
	// the imported package to mark it as complete; effectively marking the
	// wrong package as complete. By using an "unclean" package path, the
	// file and package path are different, exposing the problem if present.
	// The same issue occurs with vendoring.)
	imports := make(map[string]*types.Package)
	for i := 0; i < 3; i++ {
	if _, err := Import(imports, "./././testdata/p", tmpdir, nil); err != nil {
	t.Fatal(err)
	}
	}
	}

	func TestIssue15920(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	// On windows, we have to set the -D option for the compiler to avoid having a drive
	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
	if runtime.GOOS == "windows" {
	t.Skip("avoid dealing with relative paths/drive letters on windows")
	}

	compileAndImportPkg(t, "issue15920")
	}

	func TestIssue20046(t *testing.T) {
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	// On windows, we have to set the -D option for the compiler to avoid having a drive
	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
	if runtime.GOOS == "windows" {
	t.Skip("avoid dealing with relative paths/drive letters on windows")
	}

	// "./issue20046".V.M must exist
	pkg := compileAndImportPkg(t, "issue20046")
	obj := lookupObj(t, pkg.Scope(), "V")
	if m, index, indirect := types.LookupFieldOrMethod(obj.Type(), false, nil, "M"); m == nil {
	t.Fatalf("V.M not found (index = %v, indirect = %v)", index, indirect)
	}
	}

	func TestIssue25301(t *testing.T) {
	testenv.NeedsGo1Point(t, 11)
	// This package only handles gc export data.
	needsCompiler(t, "gc")

	// On windows, we have to set the -D option for the compiler to avoid having a drive
	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
	if runtime.GOOS == "windows" {
	t.Skip("avoid dealing with relative paths/drive letters on windows")
	}

	compileAndImportPkg(t, "issue25301")
	}

	func TestIssue51836(t *testing.T) {
	testenv.NeedsGo1Point(t, 18) // requires generics

	// This package only handles gc export data.
	needsCompiler(t, "gc")

	// On windows, we have to set the -D option for the compiler to avoid having a drive
	// letter and an illegal ':' in the import path - just skip it (see also issue #3483).
	if runtime.GOOS == "windows" {
	t.Skip("avoid dealing with relative paths/drive letters on windows")
	}

	tmpdir := mktmpdir(t)
	defer os.RemoveAll(tmpdir)
	testoutdir := filepath.Join(tmpdir, "testdata")

	dir := filepath.Join("testdata", "issue51836")
	// Following the pattern of TestIssue13898, aa.go needs to be compiled from
	// the output directory. We pass the full path to compile() so that we don't
	// have to copy the file to that directory.
	bpath, err := filepath.Abs(filepath.Join(dir, "aa.go"))
	if err != nil {
	t.Fatal(err)
	}
	compile(t, dir, "a.go", testoutdir)
	compile(t, testoutdir, bpath, testoutdir)

	// import must succeed (test for issue at hand)
	_ = importPkg(t, "./testdata/aa", tmpdir)
	}

	func importPkg(t testing.T, path, srcDir string) types.Package {
	pkg, err := Import(make(map[string]*types.Package), path, srcDir, nil)
	if err != nil {
	t.Fatal(err)
	}
	return pkg
	}

	func compileAndImportPkg(t testing.T, name string) types.Package {
	tmpdir := mktmpdir(t)
	defer os.RemoveAll(tmpdir)
	compile(t, "testdata", name+".go", filepath.Join(tmpdir, "testdata"))
	return importPkg(t, "./testdata/"+name, tmpdir)
	}

	func lookupObj(t testing.T, scope types.Scope, name string) types.Object {
	if obj := scope.Lookup(name); obj != nil {
	return obj
	}
	t.Fatalf("%s not found", name)
	return nil
	}