| // Copyright 2015 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 testenv provides information about what functionality | 
 | // is available in different testing environments run by the Go team. | 
 | // | 
 | // It is an internal package because these details are specific | 
 | // to the Go team's test setup (on build.golang.org) and not | 
 | // fundamental to tests in general. | 
 | package testenv | 
 |  | 
 | import ( | 
 | 	"errors" | 
 | 	"flag" | 
 | 	"internal/cfg" | 
 | 	"os" | 
 | 	"os/exec" | 
 | 	"path/filepath" | 
 | 	"runtime" | 
 | 	"strconv" | 
 | 	"strings" | 
 | 	"sync" | 
 | 	"testing" | 
 | ) | 
 |  | 
 | // Builder reports the name of the builder running this test | 
 | // (for example, "linux-amd64" or "windows-386-gce"). | 
 | // If the test is not running on the build infrastructure, | 
 | // Builder returns the empty string. | 
 | func Builder() string { | 
 | 	return os.Getenv("GO_BUILDER_NAME") | 
 | } | 
 |  | 
 | // HasGoBuild reports whether the current system can build programs with ``go build'' | 
 | // and then run them with os.StartProcess or exec.Command. | 
 | func HasGoBuild() bool { | 
 | 	if os.Getenv("GO_GCFLAGS") != "" { | 
 | 		// It's too much work to require every caller of the go command | 
 | 		// to pass along "-gcflags="+os.Getenv("GO_GCFLAGS"). | 
 | 		// For now, if $GO_GCFLAGS is set, report that we simply can't | 
 | 		// run go build. | 
 | 		return false | 
 | 	} | 
 | 	switch runtime.GOOS { | 
 | 	case "android", "js", "ios": | 
 | 		return false | 
 | 	} | 
 | 	return true | 
 | } | 
 |  | 
 | // MustHaveGoBuild checks that the current system can build programs with ``go build'' | 
 | // and then run them with os.StartProcess or exec.Command. | 
 | // If not, MustHaveGoBuild calls t.Skip with an explanation. | 
 | func MustHaveGoBuild(t testing.TB) { | 
 | 	if os.Getenv("GO_GCFLAGS") != "" { | 
 | 		t.Skipf("skipping test: 'go build' not compatible with setting $GO_GCFLAGS") | 
 | 	} | 
 | 	if !HasGoBuild() { | 
 | 		t.Skipf("skipping test: 'go build' not available on %s/%s", runtime.GOOS, runtime.GOARCH) | 
 | 	} | 
 | } | 
 |  | 
 | // HasGoRun reports whether the current system can run programs with ``go run.'' | 
 | func HasGoRun() bool { | 
 | 	// For now, having go run and having go build are the same. | 
 | 	return HasGoBuild() | 
 | } | 
 |  | 
 | // MustHaveGoRun checks that the current system can run programs with ``go run.'' | 
 | // If not, MustHaveGoRun calls t.Skip with an explanation. | 
 | func MustHaveGoRun(t testing.TB) { | 
 | 	if !HasGoRun() { | 
 | 		t.Skipf("skipping test: 'go run' not available on %s/%s", runtime.GOOS, runtime.GOARCH) | 
 | 	} | 
 | } | 
 |  | 
 | // GoToolPath reports the path to the Go tool. | 
 | // It is a convenience wrapper around GoTool. | 
 | // If the tool is unavailable GoToolPath calls t.Skip. | 
 | // If the tool should be available and isn't, GoToolPath calls t.Fatal. | 
 | func GoToolPath(t testing.TB) string { | 
 | 	MustHaveGoBuild(t) | 
 | 	path, err := GoTool() | 
 | 	if err != nil { | 
 | 		t.Fatal(err) | 
 | 	} | 
 | 	// Add all environment variables that affect the Go command to test metadata. | 
 | 	// Cached test results will be invalidate when these variables change. | 
 | 	// See golang.org/issue/32285. | 
 | 	for _, envVar := range strings.Fields(cfg.KnownEnv) { | 
 | 		os.Getenv(envVar) | 
 | 	} | 
 | 	return path | 
 | } | 
 |  | 
 | // GoTool reports the path to the Go tool. | 
 | func GoTool() (string, error) { | 
 | 	if !HasGoBuild() { | 
 | 		return "", errors.New("platform cannot run go tool") | 
 | 	} | 
 | 	var exeSuffix string | 
 | 	if runtime.GOOS == "windows" { | 
 | 		exeSuffix = ".exe" | 
 | 	} | 
 | 	path := filepath.Join(runtime.GOROOT(), "bin", "go"+exeSuffix) | 
 | 	if _, err := os.Stat(path); err == nil { | 
 | 		return path, nil | 
 | 	} | 
 | 	goBin, err := exec.LookPath("go" + exeSuffix) | 
 | 	if err != nil { | 
 | 		return "", errors.New("cannot find go tool: " + err.Error()) | 
 | 	} | 
 | 	return goBin, nil | 
 | } | 
 |  | 
 | // HasExec reports whether the current system can start new processes | 
 | // using os.StartProcess or (more commonly) exec.Command. | 
 | func HasExec() bool { | 
 | 	switch runtime.GOOS { | 
 | 	case "js", "ios": | 
 | 		return false | 
 | 	} | 
 | 	return true | 
 | } | 
 |  | 
 | // HasSrc reports whether the entire source tree is available under GOROOT. | 
 | func HasSrc() bool { | 
 | 	switch runtime.GOOS { | 
 | 	case "ios": | 
 | 		return false | 
 | 	} | 
 | 	return true | 
 | } | 
 |  | 
 | // MustHaveExec checks that the current system can start new processes | 
 | // using os.StartProcess or (more commonly) exec.Command. | 
 | // If not, MustHaveExec calls t.Skip with an explanation. | 
 | func MustHaveExec(t testing.TB) { | 
 | 	if !HasExec() { | 
 | 		t.Skipf("skipping test: cannot exec subprocess on %s/%s", runtime.GOOS, runtime.GOARCH) | 
 | 	} | 
 | } | 
 |  | 
 | var execPaths sync.Map // path -> error | 
 |  | 
 | // MustHaveExecPath checks that the current system can start the named executable | 
 | // using os.StartProcess or (more commonly) exec.Command. | 
 | // If not, MustHaveExecPath calls t.Skip with an explanation. | 
 | func MustHaveExecPath(t testing.TB, path string) { | 
 | 	MustHaveExec(t) | 
 |  | 
 | 	err, found := execPaths.Load(path) | 
 | 	if !found { | 
 | 		_, err = exec.LookPath(path) | 
 | 		err, _ = execPaths.LoadOrStore(path, err) | 
 | 	} | 
 | 	if err != nil { | 
 | 		t.Skipf("skipping test: %s: %s", path, err) | 
 | 	} | 
 | } | 
 |  | 
 | // HasExternalNetwork reports whether the current system can use | 
 | // external (non-localhost) networks. | 
 | func HasExternalNetwork() bool { | 
 | 	return !testing.Short() && runtime.GOOS != "js" | 
 | } | 
 |  | 
 | // MustHaveExternalNetwork checks that the current system can use | 
 | // external (non-localhost) networks. | 
 | // If not, MustHaveExternalNetwork calls t.Skip with an explanation. | 
 | func MustHaveExternalNetwork(t testing.TB) { | 
 | 	if runtime.GOOS == "js" { | 
 | 		t.Skipf("skipping test: no external network on %s", runtime.GOOS) | 
 | 	} | 
 | 	if testing.Short() { | 
 | 		t.Skipf("skipping test: no external network in -short mode") | 
 | 	} | 
 | } | 
 |  | 
 | var haveCGO bool | 
 |  | 
 | // HasCGO reports whether the current system can use cgo. | 
 | func HasCGO() bool { | 
 | 	return haveCGO | 
 | } | 
 |  | 
 | // MustHaveCGO calls t.Skip if cgo is not available. | 
 | func MustHaveCGO(t testing.TB) { | 
 | 	if !haveCGO { | 
 | 		t.Skipf("skipping test: no cgo") | 
 | 	} | 
 | } | 
 |  | 
 | // CanInternalLink reports whether the current system can link programs with | 
 | // internal linking. | 
 | // (This is the opposite of cmd/internal/sys.MustLinkExternal. Keep them in sync.) | 
 | func CanInternalLink() bool { | 
 | 	switch runtime.GOOS { | 
 | 	case "android": | 
 | 		if runtime.GOARCH != "arm64" { | 
 | 			return false | 
 | 		} | 
 | 	case "ios": | 
 | 		if runtime.GOARCH == "arm64" { | 
 | 			return false | 
 | 		} | 
 | 	} | 
 | 	return true | 
 | } | 
 |  | 
 | // MustInternalLink checks that the current system can link programs with internal | 
 | // linking. | 
 | // If not, MustInternalLink calls t.Skip with an explanation. | 
 | func MustInternalLink(t testing.TB) { | 
 | 	if !CanInternalLink() { | 
 | 		t.Skipf("skipping test: internal linking on %s/%s is not supported", runtime.GOOS, runtime.GOARCH) | 
 | 	} | 
 | } | 
 |  | 
 | // HasSymlink reports whether the current system can use os.Symlink. | 
 | func HasSymlink() bool { | 
 | 	ok, _ := hasSymlink() | 
 | 	return ok | 
 | } | 
 |  | 
 | // MustHaveSymlink reports whether the current system can use os.Symlink. | 
 | // If not, MustHaveSymlink calls t.Skip with an explanation. | 
 | func MustHaveSymlink(t testing.TB) { | 
 | 	ok, reason := hasSymlink() | 
 | 	if !ok { | 
 | 		t.Skipf("skipping test: cannot make symlinks on %s/%s%s", runtime.GOOS, runtime.GOARCH, reason) | 
 | 	} | 
 | } | 
 |  | 
 | // HasLink reports whether the current system can use os.Link. | 
 | func HasLink() bool { | 
 | 	// From Android release M (Marshmallow), hard linking files is blocked | 
 | 	// and an attempt to call link() on a file will return EACCES. | 
 | 	// - https://code.google.com/p/android-developer-preview/issues/detail?id=3150 | 
 | 	return runtime.GOOS != "plan9" && runtime.GOOS != "android" | 
 | } | 
 |  | 
 | // MustHaveLink reports whether the current system can use os.Link. | 
 | // If not, MustHaveLink calls t.Skip with an explanation. | 
 | func MustHaveLink(t testing.TB) { | 
 | 	if !HasLink() { | 
 | 		t.Skipf("skipping test: hardlinks are not supported on %s/%s", runtime.GOOS, runtime.GOARCH) | 
 | 	} | 
 | } | 
 |  | 
 | var flaky = flag.Bool("flaky", false, "run known-flaky tests too") | 
 |  | 
 | func SkipFlaky(t testing.TB, issue int) { | 
 | 	t.Helper() | 
 | 	if !*flaky { | 
 | 		t.Skipf("skipping known flaky test without the -flaky flag; see golang.org/issue/%d", issue) | 
 | 	} | 
 | } | 
 |  | 
 | func SkipFlakyNet(t testing.TB) { | 
 | 	t.Helper() | 
 | 	if v, _ := strconv.ParseBool(os.Getenv("GO_BUILDER_FLAKY_NET")); v { | 
 | 		t.Skip("skipping test on builder known to have frequent network failures") | 
 | 	} | 
 | } | 
 |  | 
 | // CleanCmdEnv will fill cmd.Env with the environment, excluding certain | 
 | // variables that could modify the behavior of the Go tools such as | 
 | // GODEBUG and GOTRACEBACK. | 
 | func CleanCmdEnv(cmd *exec.Cmd) *exec.Cmd { | 
 | 	if cmd.Env != nil { | 
 | 		panic("environment already set") | 
 | 	} | 
 | 	for _, env := range os.Environ() { | 
 | 		// Exclude GODEBUG from the environment to prevent its output | 
 | 		// from breaking tests that are trying to parse other command output. | 
 | 		if strings.HasPrefix(env, "GODEBUG=") { | 
 | 			continue | 
 | 		} | 
 | 		// Exclude GOTRACEBACK for the same reason. | 
 | 		if strings.HasPrefix(env, "GOTRACEBACK=") { | 
 | 			continue | 
 | 		} | 
 | 		cmd.Env = append(cmd.Env, env) | 
 | 	} | 
 | 	return cmd | 
 | } | 
 |  | 
 | // CPUIsSlow reports whether the CPU running the test is suspected to be slow. | 
 | func CPUIsSlow() bool { | 
 | 	switch runtime.GOARCH { | 
 | 	case "arm", "mips", "mipsle", "mips64", "mips64le": | 
 | 		return true | 
 | 	} | 
 | 	return false | 
 | } | 
 |  | 
 | // SkipIfShortAndSlow skips t if -short is set and the CPU running the test is | 
 | // suspected to be slow. | 
 | // | 
 | // (This is useful for CPU-intensive tests that otherwise complete quickly.) | 
 | func SkipIfShortAndSlow(t testing.TB) { | 
 | 	if testing.Short() && CPUIsSlow() { | 
 | 		t.Helper() | 
 | 		t.Skipf("skipping test in -short mode on %s", runtime.GOARCH) | 
 | 	} | 
 | } |