File size: 3,227 Bytes
13c2bf6 | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 | // Copyright 2018 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.
//go:build gc
package goroot
import (
"os"
"os/exec"
"path/filepath"
"strings"
"sync"
)
// IsStandardPackage reports whether path is a standard package,
// given goroot and compiler.
func IsStandardPackage(goroot, compiler, path string) bool {
switch compiler {
case "gc":
dir := filepath.Join(goroot, "src", path)
dirents, err := os.ReadDir(dir)
if err != nil {
return false
}
for _, dirent := range dirents {
if strings.HasSuffix(dirent.Name(), ".go") {
return true
}
}
return false
case "gccgo":
return gccgoSearch.isStandard(path)
default:
panic("unknown compiler " + compiler)
}
}
// gccgoDirs holds the gccgo search directories.
type gccgoDirs struct {
once sync.Once
dirs []string
}
// gccgoSearch is used to check whether a gccgo package exists in the
// standard library.
var gccgoSearch gccgoDirs
// init finds the gccgo search directories. If this fails it leaves dirs == nil.
func (gd *gccgoDirs) init() {
gccgo := os.Getenv("GCCGO")
if gccgo == "" {
gccgo = "gccgo"
}
bin, err := exec.LookPath(gccgo)
if err != nil {
return
}
allDirs, err := exec.Command(bin, "-print-search-dirs").Output()
if err != nil {
return
}
versionB, err := exec.Command(bin, "-dumpversion").Output()
if err != nil {
return
}
version := strings.TrimSpace(string(versionB))
machineB, err := exec.Command(bin, "-dumpmachine").Output()
if err != nil {
return
}
machine := strings.TrimSpace(string(machineB))
dirsEntries := strings.Split(string(allDirs), "\n")
const prefix = "libraries: ="
var dirs []string
for _, dirEntry := range dirsEntries {
if after, ok := strings.CutPrefix(dirEntry, prefix); ok {
dirs = filepath.SplitList(after)
break
}
}
if len(dirs) == 0 {
return
}
var lastDirs []string
for _, dir := range dirs {
goDir := filepath.Join(dir, "go", version)
if fi, err := os.Stat(goDir); err == nil && fi.IsDir() {
gd.dirs = append(gd.dirs, goDir)
goDir = filepath.Join(goDir, machine)
if fi, err = os.Stat(goDir); err == nil && fi.IsDir() {
gd.dirs = append(gd.dirs, goDir)
}
}
if fi, err := os.Stat(dir); err == nil && fi.IsDir() {
lastDirs = append(lastDirs, dir)
}
}
gd.dirs = append(gd.dirs, lastDirs...)
}
// isStandard reports whether path is a standard library for gccgo.
func (gd *gccgoDirs) isStandard(path string) bool {
// Quick check: if the first path component has a '.', it's not
// in the standard library. This skips most GOPATH directories.
i := strings.Index(path, "/")
if i < 0 {
i = len(path)
}
if strings.Contains(path[:i], ".") {
return false
}
if path == "unsafe" {
// Special case.
return true
}
gd.once.Do(gd.init)
if gd.dirs == nil {
// We couldn't find the gccgo search directories.
// Best guess, since the first component did not contain
// '.', is that this is a standard library package.
return true
}
for _, dir := range gd.dirs {
full := filepath.Join(dir, path) + ".gox"
if fi, err := os.Stat(full); err == nil && !fi.IsDir() {
return true
}
}
return false
}
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