blob: 60d45ac0e64d04b28ceef20c1e80250a948d4186 [file] [log] [blame]
// 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"
"strings"
)
// GoVersion checks the go version by running "go list" with modules off.
// It returns the X in Go 1.X.
func GoVersion(ctx context.Context, inv Invocation, r *Runner) (int, error) {
inv.Verb = "list"
inv.Args = []string{"-e", "-f", `{{context.ReleaseTags}}`}
inv.Env = append(append([]string{}, inv.Env...), "GO111MODULE=off")
// Unset any unneeded flags.
inv.ModFile = ""
inv.ModFlag = ""
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]"
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)
}