blob: 6575cfb9df60d3f29c9cb5a8ac3d8e3432aa0503 [file] [log] [blame]
// Copyright 2022 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 goroot is a copy of package internal/goroot
// in the main GO repot. It provides a utility to produce
// an importcfg and import path to package file map mapping
// standard library packages to the locations of their export
// data files.
package goroot
import (
"bytes"
"fmt"
"os/exec"
"strings"
"sync"
)
// Importcfg returns an importcfg file to be passed to the
// Go compiler that contains the cached paths for the .a files for the
// standard library.
func Importcfg() (string, error) {
var icfg bytes.Buffer
m, err := PkgfileMap()
if err != nil {
return "", err
}
fmt.Fprintf(&icfg, "# import config")
for importPath, export := range m {
if importPath != "unsafe" && export != "" { // unsafe
fmt.Fprintf(&icfg, "\npackagefile %s=%s", importPath, export)
}
}
s := icfg.String()
return s, nil
}
var (
stdlibPkgfileMap map[string]string
stdlibPkgfileErr error
once sync.Once
)
// PkgfileMap returns a map of package paths to the location on disk
// of the .a file for the package.
// The caller must not modify the map.
func PkgfileMap() (map[string]string, error) {
once.Do(func() {
m := make(map[string]string)
output, err := exec.Command("go", "list", "-export", "-e", "-f", "{{.ImportPath}} {{.Export}}", "std", "cmd").Output()
if err != nil {
stdlibPkgfileErr = err
}
for _, line := range strings.Split(string(output), "\n") {
if line == "" {
continue
}
sp := strings.SplitN(line, " ", 2)
if len(sp) != 2 {
err = fmt.Errorf("determining pkgfile map: invalid line in go list output: %q", line)
return
}
importPath, export := sp[0], sp[1]
m[importPath] = export
}
stdlibPkgfileMap = m
})
return stdlibPkgfileMap, stdlibPkgfileErr
}