src/cmd/go/internal/modload/search.go

   1 // Copyright 2018 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package modload
   6
   7 import (
   8         "context"
   9         "fmt"
  10         "io/fs"
  11         "os"
  12         "path/filepath"
  13         "strings"
  14
  15         "cmd/go/internal/cfg"
  16         "cmd/go/internal/fsys"
  17         "cmd/go/internal/imports"
  18         "cmd/go/internal/search"
  19
  20         "golang.org/x/mod/module"
  21 )
  22
  23 type stdFilter int8
  24
  25 const (
  26         omitStd = stdFilter(iota)
  27         includeStd
  28 )
  29
  30 // matchPackages is like m.MatchPackages, but uses a local variable (rather than
  31 // a global) for tags, can include or exclude packages in the standard library,
  32 // and is restricted to the given list of modules.
  33 func matchPackages(ctx context.Context, m *search.Match, tags map[string]bool, filter stdFilter, modules []module.Version) {
  34         m.Pkgs = []string{}
  35
  36         isMatch := func(string) bool { return true }
  37         treeCanMatch := func(string) bool { return true }
  38         if !m.IsMeta() {
  39                 isMatch = search.MatchPattern(m.Pattern())
  40                 treeCanMatch = search.TreeCanMatchPattern(m.Pattern())
  41         }
  42
  43         have := map[string]bool{
  44                 "builtin": true, // ignore pseudo-package that exists only for documentation
  45         }
  46         if !cfg.BuildContext.CgoEnabled {
  47                 have["runtime/cgo"] = true // ignore during walk
  48         }
  49
  50         type pruning int8
  51         const (
  52                 pruneVendor = pruning(1 << iota)
  53                 pruneGoMod
  54         )
  55
  56         walkPkgs := func(root, importPathRoot string, prune pruning) {
  57                 root = filepath.Clean(root)
  58                 err := fsys.Walk(root, func(path string, fi fs.FileInfo, err error) error {
  59                         if err != nil {
  60                                 m.AddError(err)
  61                                 return nil
  62                         }
  63
  64                         want := true
  65                         elem := ""
  66
  67                         // Don't use GOROOT/src but do walk down into it.
  68                         if path == root {
  69                                 if importPathRoot == "" {
  70                                         return nil
  71                                 }
  72                         } else {
  73                                 // Avoid .foo, _foo, and testdata subdirectory trees.
  74                                 _, elem = filepath.Split(path)
  75                                 if strings.HasPrefix(elem, ".") || strings.HasPrefix(elem, "_") || elem == "testdata" {
  76                                         want = false
  77                                 }
  78                         }
  79
  80                         name := importPathRoot + filepath.ToSlash(path[len(root):])
  81                         if importPathRoot == "" {
  82                                 name = name[1:] // cut leading slash
  83                         }
  84                         if !treeCanMatch(name) {
  85                                 want = false
  86                         }
  87
  88                         if !fi.IsDir() {
  89                                 if fi.Mode()&fs.ModeSymlink != 0 && want {
  90                                         if target, err := os.Stat(path); err == nil && target.IsDir() {
  91                                                 fmt.Fprintf(os.Stderr, "warning: ignoring symlink %s\n", path)
  92                                         }
  93                                 }
  94                                 return nil
  95                         }
  96
  97                         if !want {
  98                                 return filepath.SkipDir
  99                         }
 100                         // Stop at module boundaries.
 101                         if (prune&pruneGoMod != 0) && path != root {
 102                                 if fi, err := os.Stat(filepath.Join(path, "go.mod")); err == nil && !fi.IsDir() {
 103                                         return filepath.SkipDir
 104                                 }
 105                         }
 106
 107                         if !have[name] {
 108                                 have[name] = true
 109                                 if isMatch(name) {
 110                                         if _, _, err := scanDir(path, tags); err != imports.ErrNoGo {
 111                                                 m.Pkgs = append(m.Pkgs, name)
 112                                         }
 113                                 }
 114                         }
 115
 116                         if elem == "vendor" && (prune&pruneVendor != 0) {
 117                                 return filepath.SkipDir
 118                         }
 119                         return nil
 120                 })
 121                 if err != nil {
 122                         m.AddError(err)
 123                 }
 124         }
 125
 126         if filter == includeStd {
 127                 walkPkgs(cfg.GOROOTsrc, "", pruneGoMod)
 128                 if treeCanMatch("cmd") {
 129                         walkPkgs(filepath.Join(cfg.GOROOTsrc, "cmd"), "cmd", pruneGoMod)
 130                 }
 131         }
 132
 133         if cfg.BuildMod == "vendor" {
 134                 if HasModRoot() {
 135                         walkPkgs(ModRoot(), targetPrefix, pruneGoMod|pruneVendor)
 136                         walkPkgs(filepath.Join(ModRoot(), "vendor"), "", pruneVendor)
 137                 }
 138                 return
 139         }
 140
 141         for _, mod := range modules {
 142                 if !treeCanMatch(mod.Path) {
 143                         continue
 144                 }
 145
 146                 var (
 147                         root, modPrefix string
 148                         isLocal         bool
 149                 )
 150                 if mod == Target {
 151                         if !HasModRoot() {
 152                                 continue // If there is no main module, we can't search in it.
 153                         }
 154                         root = ModRoot()
 155                         modPrefix = targetPrefix
 156                         isLocal = true
 157                 } else {
 158                         var err error
 159                         root, isLocal, err = fetch(ctx, mod)
 160                         if err != nil {
 161                                 m.AddError(err)
 162                                 continue
 163                         }
 164                         modPrefix = mod.Path
 165                 }
 166
 167                 prune := pruneVendor
 168                 if isLocal {
 169                         prune |= pruneGoMod
 170                 }
 171                 walkPkgs(root, modPrefix, prune)
 172         }
 173
 174         return
 175 }