| // 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 |
| } |