diff options
Diffstat (limited to 'vendor/golang.org/x/tools/internal/gocommand')
3 files changed, 789 insertions, 0 deletions
diff --git a/vendor/golang.org/x/tools/internal/gocommand/invoke.go b/vendor/golang.org/x/tools/internal/gocommand/invoke.go new file mode 100644 index 0000000..2e59ff8 --- /dev/null +++ b/vendor/golang.org/x/tools/internal/gocommand/invoke.go @@ -0,0 +1,555 @@ +// Copyright 2020 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 gocommand is a helper for calling the go command. +package gocommand + +import ( + "bytes" + "context" + "encoding/json" + "errors" + "fmt" + "io" + "log" + "os" + "os/exec" + "path/filepath" + "reflect" + "regexp" + "runtime" + "strconv" + "strings" + "sync" + "time" + + "golang.org/x/tools/internal/event" + "golang.org/x/tools/internal/event/keys" + "golang.org/x/tools/internal/event/label" +) + +// An Runner will run go command invocations and serialize +// them if it sees a concurrency error. +type Runner struct { + // once guards the runner initialization. + once sync.Once + + // inFlight tracks available workers. + inFlight chan struct{} + + // serialized guards the ability to run a go command serially, + // to avoid deadlocks when claiming workers. + serialized chan struct{} +} + +const maxInFlight = 10 + +func (runner *Runner) initialize() { + runner.once.Do(func() { + runner.inFlight = make(chan struct{}, maxInFlight) + runner.serialized = make(chan struct{}, 1) + }) +} + +// 1.13: go: updates to go.mod needed, but contents have changed +// 1.14: go: updating go.mod: existing contents have changed since last read +var modConcurrencyError = regexp.MustCompile(`go:.*go.mod.*contents have changed`) + +// event keys for go command invocations +var ( + verb = keys.NewString("verb", "go command verb") + directory = keys.NewString("directory", "") +) + +func invLabels(inv Invocation) []label.Label { + return []label.Label{verb.Of(inv.Verb), directory.Of(inv.WorkingDir)} +} + +// Run is a convenience wrapper around RunRaw. +// It returns only stdout and a "friendly" error. +func (runner *Runner) Run(ctx context.Context, inv Invocation) (*bytes.Buffer, error) { + ctx, done := event.Start(ctx, "gocommand.Runner.Run", invLabels(inv)...) + defer done() + + stdout, _, friendly, _ := runner.RunRaw(ctx, inv) + return stdout, friendly +} + +// RunPiped runs the invocation serially, always waiting for any concurrent +// invocations to complete first. +func (runner *Runner) RunPiped(ctx context.Context, inv Invocation, stdout, stderr io.Writer) error { + ctx, done := event.Start(ctx, "gocommand.Runner.RunPiped", invLabels(inv)...) + defer done() + + _, err := runner.runPiped(ctx, inv, stdout, stderr) + return err +} + +// RunRaw runs the invocation, serializing requests only if they fight over +// go.mod changes. +// Postcondition: both error results have same nilness. +func (runner *Runner) RunRaw(ctx context.Context, inv Invocation) (*bytes.Buffer, *bytes.Buffer, error, error) { + ctx, done := event.Start(ctx, "gocommand.Runner.RunRaw", invLabels(inv)...) + defer done() + // Make sure the runner is always initialized. + runner.initialize() + + // First, try to run the go command concurrently. + stdout, stderr, friendlyErr, err := runner.runConcurrent(ctx, inv) + + // If we encounter a load concurrency error, we need to retry serially. + if friendlyErr != nil && modConcurrencyError.MatchString(friendlyErr.Error()) { + event.Error(ctx, "Load concurrency error, will retry serially", err) + + // Run serially by calling runPiped. + stdout.Reset() + stderr.Reset() + friendlyErr, err = runner.runPiped(ctx, inv, stdout, stderr) + } + + return stdout, stderr, friendlyErr, err +} + +// Postcondition: both error results have same nilness. +func (runner *Runner) runConcurrent(ctx context.Context, inv Invocation) (*bytes.Buffer, *bytes.Buffer, error, error) { + // Wait for 1 worker to become available. + select { + case <-ctx.Done(): + return nil, nil, ctx.Err(), ctx.Err() + case runner.inFlight <- struct{}{}: + defer func() { <-runner.inFlight }() + } + + stdout, stderr := &bytes.Buffer{}, &bytes.Buffer{} + friendlyErr, err := inv.runWithFriendlyError(ctx, stdout, stderr) + return stdout, stderr, friendlyErr, err +} + +// Postcondition: both error results have same nilness. +func (runner *Runner) runPiped(ctx context.Context, inv Invocation, stdout, stderr io.Writer) (error, error) { + // Make sure the runner is always initialized. + runner.initialize() + + // Acquire the serialization lock. This avoids deadlocks between two + // runPiped commands. + select { + case <-ctx.Done(): + return ctx.Err(), ctx.Err() + case runner.serialized <- struct{}{}: + defer func() { <-runner.serialized }() + } + + // Wait for all in-progress go commands to return before proceeding, + // to avoid load concurrency errors. + for i := 0; i < maxInFlight; i++ { + select { + case <-ctx.Done(): + return ctx.Err(), ctx.Err() + case runner.inFlight <- struct{}{}: + // Make sure we always "return" any workers we took. + defer func() { <-runner.inFlight }() + } + } + + return inv.runWithFriendlyError(ctx, stdout, stderr) +} + +// An Invocation represents a call to the go command. +type Invocation struct { + Verb string + Args []string + BuildFlags []string + + // If ModFlag is set, the go command is invoked with -mod=ModFlag. + // TODO(rfindley): remove, in favor of Args. + ModFlag string + + // If ModFile is set, the go command is invoked with -modfile=ModFile. + // TODO(rfindley): remove, in favor of Args. + ModFile string + + // Overlay is the name of the JSON overlay file that describes + // unsaved editor buffers; see [WriteOverlays]. + // If set, the go command is invoked with -overlay=Overlay. + // TODO(rfindley): remove, in favor of Args. + Overlay string + + // If CleanEnv is set, the invocation will run only with the environment + // in Env, not starting with os.Environ. + CleanEnv bool + Env []string + WorkingDir string + Logf func(format string, args ...interface{}) +} + +// Postcondition: both error results have same nilness. +func (i *Invocation) runWithFriendlyError(ctx context.Context, stdout, stderr io.Writer) (friendlyError error, rawError error) { + rawError = i.run(ctx, stdout, stderr) + if rawError != nil { + friendlyError = rawError + // Check for 'go' executable not being found. + if ee, ok := rawError.(*exec.Error); ok && ee.Err == exec.ErrNotFound { + friendlyError = fmt.Errorf("go command required, not found: %v", ee) + } + if ctx.Err() != nil { + friendlyError = ctx.Err() + } + friendlyError = fmt.Errorf("err: %v: stderr: %s", friendlyError, stderr) + } + return +} + +// logf logs if i.Logf is non-nil. +func (i *Invocation) logf(format string, args ...any) { + if i.Logf != nil { + i.Logf(format, args...) + } +} + +func (i *Invocation) run(ctx context.Context, stdout, stderr io.Writer) error { + goArgs := []string{i.Verb} + + appendModFile := func() { + if i.ModFile != "" { + goArgs = append(goArgs, "-modfile="+i.ModFile) + } + } + appendModFlag := func() { + if i.ModFlag != "" { + goArgs = append(goArgs, "-mod="+i.ModFlag) + } + } + appendOverlayFlag := func() { + if i.Overlay != "" { + goArgs = append(goArgs, "-overlay="+i.Overlay) + } + } + + switch i.Verb { + case "env", "version": + goArgs = append(goArgs, i.Args...) + case "mod": + // mod needs the sub-verb before flags. + goArgs = append(goArgs, i.Args[0]) + appendModFile() + goArgs = append(goArgs, i.Args[1:]...) + case "get": + goArgs = append(goArgs, i.BuildFlags...) + appendModFile() + goArgs = append(goArgs, i.Args...) + + default: // notably list and build. + goArgs = append(goArgs, i.BuildFlags...) + appendModFile() + appendModFlag() + appendOverlayFlag() + goArgs = append(goArgs, i.Args...) + } + cmd := exec.Command("go", goArgs...) + 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)) + } + + // The cwd gets resolved to the real path. On Darwin, where + // /tmp is a symlink, this breaks anything that expects the + // working directory to keep the original path, including the + // go command when dealing with modules. + // + // os.Getwd has a special feature where if the cwd and the PWD + // are the same node then it trusts the PWD, so by setting it + // in the env for the child process we fix up all the paths + // returned by the go command. + if !i.CleanEnv { + cmd.Env = os.Environ() + } + cmd.Env = append(cmd.Env, i.Env...) + if i.WorkingDir != "" { + cmd.Env = append(cmd.Env, "PWD="+i.WorkingDir) + cmd.Dir = i.WorkingDir + } + + debugStr := cmdDebugStr(cmd) + i.logf("starting %v", debugStr) + start := time.Now() + defer func() { + i.logf("%s for %v", time.Since(start), debugStr) + }() + + return runCmdContext(ctx, cmd) +} + +// DebugHangingGoCommands may be set by tests to enable additional +// instrumentation (including panics) for debugging hanging Go commands. +// +// See golang/go#54461 for details. +var DebugHangingGoCommands = false + +// runCmdContext is like exec.CommandContext except it sends os.Interrupt +// before os.Kill. +func runCmdContext(ctx context.Context, cmd *exec.Cmd) (err error) { + // If cmd.Stdout is not an *os.File, the exec package will create a pipe and + // copy it to the Writer in a goroutine until the process has finished and + // either the pipe reaches EOF or command's WaitDelay expires. + // + // However, the output from 'go list' can be quite large, and we don't want to + // keep reading (and allocating buffers) if we've already decided we don't + // care about the output. We don't want to wait for the process to finish, and + // we don't wait to wait for the WaitDelay to expire either. + // + // Instead, if cmd.Stdout requires a copying goroutine we explicitly replace + // it with a pipe (which is an *os.File), which we can close in order to stop + // copying output as soon as we realize we don't care about it. + var stdoutW *os.File + if cmd.Stdout != nil { + if _, ok := cmd.Stdout.(*os.File); !ok { + var stdoutR *os.File + stdoutR, stdoutW, err = os.Pipe() + if err != nil { + return err + } + prevStdout := cmd.Stdout + cmd.Stdout = stdoutW + + stdoutErr := make(chan error, 1) + go func() { + _, err := io.Copy(prevStdout, stdoutR) + if err != nil { + err = fmt.Errorf("copying stdout: %w", err) + } + stdoutErr <- err + }() + defer func() { + // We started a goroutine to copy a stdout pipe. + // Wait for it to finish, or terminate it if need be. + var err2 error + select { + case err2 = <-stdoutErr: + stdoutR.Close() + case <-ctx.Done(): + stdoutR.Close() + // Per https://pkg.go.dev/os#File.Close, the call to stdoutR.Close + // should cause the Read call in io.Copy to unblock and return + // immediately, but we still need to receive from stdoutErr to confirm + // that it has happened. + <-stdoutErr + err2 = ctx.Err() + } + if err == nil { + err = err2 + } + }() + + // Per https://pkg.go.dev/os/exec#Cmd, “If Stdout and Stderr are the + // same writer, and have a type that can be compared with ==, at most + // one goroutine at a time will call Write.” + // + // Since we're starting a goroutine that writes to cmd.Stdout, we must + // also update cmd.Stderr so that it still holds. + func() { + defer func() { recover() }() + if cmd.Stderr == prevStdout { + cmd.Stderr = cmd.Stdout + } + }() + } + } + + startTime := time.Now() + err = cmd.Start() + if stdoutW != nil { + // The child process has inherited the pipe file, + // so close the copy held in this process. + stdoutW.Close() + stdoutW = nil + } + if err != nil { + return err + } + + resChan := make(chan error, 1) + go func() { + resChan <- cmd.Wait() + }() + + // If we're interested in debugging hanging Go commands, stop waiting after a + // minute and panic with interesting information. + debug := DebugHangingGoCommands + if debug { + timer := time.NewTimer(1 * time.Minute) + defer timer.Stop() + select { + case err := <-resChan: + return err + case <-timer.C: + HandleHangingGoCommand(startTime, cmd) + case <-ctx.Done(): + } + } else { + select { + case err := <-resChan: + return err + case <-ctx.Done(): + } + } + + // Cancelled. Interrupt and see if it ends voluntarily. + if err := cmd.Process.Signal(os.Interrupt); err == nil { + // (We used to wait only 1s but this proved + // fragile on loaded builder machines.) + timer := time.NewTimer(5 * time.Second) + defer timer.Stop() + select { + case err := <-resChan: + return err + case <-timer.C: + } + } + + // Didn't shut down in response to interrupt. Kill it hard. + // TODO(rfindley): per advice from bcmills@, it may be better to send SIGQUIT + // on certain platforms, such as unix. + if err := cmd.Process.Kill(); err != nil && !errors.Is(err, os.ErrProcessDone) && debug { + log.Printf("error killing the Go command: %v", err) + } + + return <-resChan +} + +func HandleHangingGoCommand(start time.Time, cmd *exec.Cmd) { + switch runtime.GOOS { + case "linux", "darwin", "freebsd", "netbsd": + fmt.Fprintln(os.Stderr, `DETECTED A HANGING GO COMMAND + +The gopls test runner has detected a hanging go command. In order to debug +this, the output of ps and lsof/fstat is printed below. + +See golang/go#54461 for more details.`) + + fmt.Fprintln(os.Stderr, "\nps axo ppid,pid,command:") + fmt.Fprintln(os.Stderr, "-------------------------") + psCmd := exec.Command("ps", "axo", "ppid,pid,command") + psCmd.Stdout = os.Stderr + psCmd.Stderr = os.Stderr + if err := psCmd.Run(); err != nil { + panic(fmt.Sprintf("running ps: %v", err)) + } + + listFiles := "lsof" + if runtime.GOOS == "freebsd" || runtime.GOOS == "netbsd" { + listFiles = "fstat" + } + + fmt.Fprintln(os.Stderr, "\n"+listFiles+":") + fmt.Fprintln(os.Stderr, "-----") + listFilesCmd := exec.Command(listFiles) + listFilesCmd.Stdout = os.Stderr + listFilesCmd.Stderr = os.Stderr + if err := listFilesCmd.Run(); err != nil { + panic(fmt.Sprintf("running %s: %v", listFiles, err)) + } + } + panic(fmt.Sprintf("detected hanging go command (golang/go#54461); waited %s\n\tcommand:%s\n\tpid:%d", time.Since(start), cmd, cmd.Process.Pid)) +} + +func cmdDebugStr(cmd *exec.Cmd) string { + env := make(map[string]string) + for _, kv := range cmd.Env { + split := strings.SplitN(kv, "=", 2) + if len(split) == 2 { + k, v := split[0], split[1] + env[k] = v + } + } + + var args []string + for _, arg := range cmd.Args { + quoted := strconv.Quote(arg) + if quoted[1:len(quoted)-1] != arg || strings.Contains(arg, " ") { + args = append(args, quoted) + } else { + args = append(args, arg) + } + } + return fmt.Sprintf("GOROOT=%v GOPATH=%v GO111MODULE=%v GOPROXY=%v PWD=%v %v", env["GOROOT"], env["GOPATH"], env["GO111MODULE"], env["GOPROXY"], env["PWD"], strings.Join(args, " ")) +} + +// WriteOverlays writes each value in the overlay (see the Overlay +// field of go/packages.Config) to a temporary file and returns the name +// of a JSON file describing the mapping that is suitable for the "go +// list -overlay" flag. +// +// On success, the caller must call the cleanup function exactly once +// when the files are no longer needed. +func WriteOverlays(overlay map[string][]byte) (filename string, cleanup func(), err error) { + // Do nothing if there are no overlays in the config. + if len(overlay) == 0 { + return "", func() {}, nil + } + + dir, err := os.MkdirTemp("", "gocommand-*") + if err != nil { + return "", nil, err + } + + // The caller must clean up this directory, + // unless this function returns an error. + // (The cleanup operand of each return + // statement below is ignored.) + defer func() { + cleanup = func() { + os.RemoveAll(dir) + } + if err != nil { + cleanup() + cleanup = nil + } + }() + + // Write each map entry to a temporary file. + overlays := make(map[string]string) + for k, v := range overlay { + // Use a unique basename for each file (001-foo.go), + // to avoid creating nested directories. + base := fmt.Sprintf("%d-%s", 1+len(overlays), filepath.Base(k)) + filename := filepath.Join(dir, base) + err := os.WriteFile(filename, v, 0666) + if err != nil { + return "", nil, err + } + overlays[k] = filename + } + + // Write the JSON overlay file that maps logical file names to temp files. + // + // OverlayJSON is the format overlay files are expected to be in. + // The Replace map maps from overlaid paths to replacement paths: + // the Go command will forward all reads trying to open + // each overlaid path to its replacement path, or consider the overlaid + // path not to exist if the replacement path is empty. + // + // From golang/go#39958. + type OverlayJSON struct { + Replace map[string]string `json:"replace,omitempty"` + } + b, err := json.Marshal(OverlayJSON{Replace: overlays}) + if err != nil { + return "", nil, err + } + filename = filepath.Join(dir, "overlay.json") + if err := os.WriteFile(filename, b, 0666); err != nil { + return "", nil, err + } + + return filename, nil, nil +} diff --git a/vendor/golang.org/x/tools/internal/gocommand/vendor.go b/vendor/golang.org/x/tools/internal/gocommand/vendor.go new file mode 100644 index 0000000..e38d1fb --- /dev/null +++ b/vendor/golang.org/x/tools/internal/gocommand/vendor.go @@ -0,0 +1,163 @@ +// Copyright 2020 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 gocommand + +import ( + "bytes" + "context" + "fmt" + "os" + "path/filepath" + "regexp" + "strings" + "time" + + "golang.org/x/mod/semver" +) + +// ModuleJSON holds information about a module. +type ModuleJSON struct { + Path string // module path + Version string // module version + Versions []string // available module versions (with -versions) + Replace *ModuleJSON // replaced by this module + Time *time.Time // time version was created + Update *ModuleJSON // available update, if any (with -u) + Main bool // is this the main module? + Indirect bool // is this module only an indirect dependency of main module? + Dir string // directory holding files for this module, if any + GoMod string // path to go.mod file used when loading this module, if any + GoVersion string // go version used in module +} + +var modFlagRegexp = regexp.MustCompile(`-mod[ =](\w+)`) + +// VendorEnabled reports whether vendoring is enabled. It takes a *Runner to execute Go commands +// with the supplied context.Context and Invocation. The Invocation can contain pre-defined fields, +// of which only Verb and Args are modified to run the appropriate Go command. +// Inspired by setDefaultBuildMod in modload/init.go +func VendorEnabled(ctx context.Context, inv Invocation, r *Runner) (bool, *ModuleJSON, error) { + mainMod, go114, err := getMainModuleAnd114(ctx, inv, r) + if err != nil { + return false, nil, err + } + + // We check the GOFLAGS to see if there is anything overridden or not. + inv.Verb = "env" + inv.Args = []string{"GOFLAGS"} + stdout, err := r.Run(ctx, inv) + if err != nil { + return false, nil, err + } + goflags := string(bytes.TrimSpace(stdout.Bytes())) + matches := modFlagRegexp.FindStringSubmatch(goflags) + var modFlag string + if len(matches) != 0 { + modFlag = matches[1] + } + // Don't override an explicit '-mod=' argument. + if modFlag == "vendor" { + return true, mainMod, nil + } else if modFlag != "" { + return false, nil, nil + } + if mainMod == nil || !go114 { + return false, nil, nil + } + // Check 1.14's automatic vendor mode. + if fi, err := os.Stat(filepath.Join(mainMod.Dir, "vendor")); err == nil && fi.IsDir() { + if mainMod.GoVersion != "" && semver.Compare("v"+mainMod.GoVersion, "v1.14") >= 0 { + // The Go version is at least 1.14, and a vendor directory exists. + // Set -mod=vendor by default. + return true, mainMod, nil + } + } + return false, nil, nil +} + +// getMainModuleAnd114 gets one of the main modules' information and whether the +// go command in use is 1.14+. This is the information needed to figure out +// if vendoring should be enabled. +func getMainModuleAnd114(ctx context.Context, inv Invocation, r *Runner) (*ModuleJSON, bool, error) { + const format = `{{.Path}} +{{.Dir}} +{{.GoMod}} +{{.GoVersion}} +{{range context.ReleaseTags}}{{if eq . "go1.14"}}{{.}}{{end}}{{end}} +` + inv.Verb = "list" + inv.Args = []string{"-m", "-f", format} + stdout, err := r.Run(ctx, inv) + if err != nil { + return nil, false, err + } + + lines := strings.Split(stdout.String(), "\n") + if len(lines) < 5 { + return nil, false, fmt.Errorf("unexpected stdout: %q", stdout.String()) + } + mod := &ModuleJSON{ + Path: lines[0], + Dir: lines[1], + GoMod: lines[2], + GoVersion: lines[3], + Main: true, + } + return mod, lines[4] == "go1.14", nil +} + +// WorkspaceVendorEnabled reports whether workspace vendoring is enabled. It takes a *Runner to execute Go commands +// with the supplied context.Context and Invocation. The Invocation can contain pre-defined fields, +// of which only Verb and Args are modified to run the appropriate Go command. +// Inspired by setDefaultBuildMod in modload/init.go +func WorkspaceVendorEnabled(ctx context.Context, inv Invocation, r *Runner) (bool, []*ModuleJSON, error) { + inv.Verb = "env" + inv.Args = []string{"GOWORK"} + stdout, err := r.Run(ctx, inv) + if err != nil { + return false, nil, err + } + goWork := string(bytes.TrimSpace(stdout.Bytes())) + if fi, err := os.Stat(filepath.Join(filepath.Dir(goWork), "vendor")); err == nil && fi.IsDir() { + mainMods, err := getWorkspaceMainModules(ctx, inv, r) + if err != nil { + return false, nil, err + } + return true, mainMods, nil + } + return false, nil, nil +} + +// getWorkspaceMainModules gets the main modules' information. +// This is the information needed to figure out if vendoring should be enabled. +func getWorkspaceMainModules(ctx context.Context, inv Invocation, r *Runner) ([]*ModuleJSON, error) { + const format = `{{.Path}} +{{.Dir}} +{{.GoMod}} +{{.GoVersion}} +` + inv.Verb = "list" + inv.Args = []string{"-m", "-f", format} + stdout, err := r.Run(ctx, inv) + if err != nil { + return nil, err + } + + lines := strings.Split(strings.TrimSuffix(stdout.String(), "\n"), "\n") + if len(lines) < 4 { + return nil, fmt.Errorf("unexpected stdout: %q", stdout.String()) + } + mods := make([]*ModuleJSON, 0, len(lines)/4) + for i := 0; i < len(lines); i += 4 { + mods = append(mods, &ModuleJSON{ + Path: lines[i], + Dir: lines[i+1], + GoMod: lines[i+2], + GoVersion: lines[i+3], + Main: true, + }) + } + return mods, nil +} diff --git a/vendor/golang.org/x/tools/internal/gocommand/version.go b/vendor/golang.org/x/tools/internal/gocommand/version.go new file mode 100644 index 0000000..446c584 --- /dev/null +++ b/vendor/golang.org/x/tools/internal/gocommand/version.go @@ -0,0 +1,71 @@ +// Copyright 2020 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 gocommand + +import ( + "context" + "fmt" + "regexp" + "strings" +) + +// GoVersion reports the minor version number of the highest release +// tag built into the go command on the PATH. +// +// Note that this may be higher than the version of the go tool used +// to build this application, and thus the versions of the standard +// go/{scanner,parser,ast,types} packages that are linked into it. +// In that case, callers should either downgrade to the version of +// go used to build the application, or report an error that the +// application is too old to use the go command on the PATH. +func GoVersion(ctx context.Context, inv Invocation, r *Runner) (int, error) { + inv.Verb = "list" + inv.Args = []string{"-e", "-f", `{{context.ReleaseTags}}`, `--`, `unsafe`} + inv.BuildFlags = nil // This is not a build command. + inv.ModFlag = "" + inv.ModFile = "" + inv.Env = append(inv.Env[:len(inv.Env):len(inv.Env)], "GO111MODULE=off") + + stdoutBytes, err := r.Run(ctx, inv) + if err != nil { + return 0, err + } + stdout := stdoutBytes.String() + if len(stdout) < 3 { + return 0, fmt.Errorf("bad ReleaseTags output: %q", stdout) + } + // Split up "[go1.1 go1.15]" and return highest go1.X value. + tags := strings.Fields(stdout[1 : len(stdout)-2]) + for i := len(tags) - 1; i >= 0; i-- { + var version int + if _, err := fmt.Sscanf(tags[i], "go1.%d", &version); err != nil { + continue + } + return version, nil + } + return 0, fmt.Errorf("no parseable ReleaseTags in %v", tags) +} + +// GoVersionOutput returns the complete output of the go version command. +func GoVersionOutput(ctx context.Context, inv Invocation, r *Runner) (string, error) { + inv.Verb = "version" + goVersion, err := r.Run(ctx, inv) + if err != nil { + return "", err + } + return goVersion.String(), nil +} + +// ParseGoVersionOutput extracts the Go version string +// from the output of the "go version" command. +// Given an unrecognized form, it returns an empty string. +func ParseGoVersionOutput(data string) string { + re := regexp.MustCompile(`^go version (go\S+|devel \S+)`) + m := re.FindStringSubmatch(data) + if len(m) != 2 { + return "" // unrecognized version + } + return m[1] +} |