- package imports
-
- import (
- "bytes"
- "context"
- "encoding/json"
- "fmt"
- "io/ioutil"
- "os"
- "path"
- "path/filepath"
- "regexp"
- "sort"
- "strconv"
- "strings"
-
- "golang.org/x/mod/module"
- "golang.org/x/tools/internal/gocommand"
- "golang.org/x/tools/internal/gopathwalk"
- )
-
- // ModuleResolver implements resolver for modules using the go command as little
- // as feasible.
- type ModuleResolver struct {
- env *ProcessEnv
- moduleCacheDir string
- dummyVendorMod *gocommand.ModuleJSON // If vendoring is enabled, the pseudo-module that represents the /vendor directory.
- roots []gopathwalk.Root
- scanSema chan struct{} // scanSema prevents concurrent scans and guards scannedRoots.
- scannedRoots map[gopathwalk.Root]bool
-
- initialized bool
- main *gocommand.ModuleJSON
- modsByModPath []*gocommand.ModuleJSON // All modules, ordered by # of path components in module Path...
- modsByDir []*gocommand.ModuleJSON // ...or Dir.
-
- // moduleCacheCache stores information about the module cache.
- moduleCacheCache *dirInfoCache
- otherCache *dirInfoCache
- }
-
- func newModuleResolver(e *ProcessEnv) *ModuleResolver {
- r := &ModuleResolver{
- env: e,
- scanSema: make(chan struct{}, 1),
- }
- r.scanSema <- struct{}{}
- return r
- }
-
- func (r *ModuleResolver) init() error {
- if r.initialized {
- return nil
- }
-
- goenv, err := r.env.goEnv()
- if err != nil {
- return err
- }
- inv := gocommand.Invocation{
- BuildFlags: r.env.BuildFlags,
- Env: r.env.env(),
- Logf: r.env.Logf,
- WorkingDir: r.env.WorkingDir,
- }
- mainMod, vendorEnabled, err := gocommand.VendorEnabled(context.TODO(), inv, r.env.GocmdRunner)
- if err != nil {
- return err
- }
-
- if mainMod != nil && vendorEnabled {
- // Vendor mode is on, so all the non-Main modules are irrelevant,
- // and we need to search /vendor for everything.
- r.main = mainMod
- r.dummyVendorMod = &gocommand.ModuleJSON{
- Path: "",
- Dir: filepath.Join(mainMod.Dir, "vendor"),
- }
- r.modsByModPath = []*gocommand.ModuleJSON{mainMod, r.dummyVendorMod}
- r.modsByDir = []*gocommand.ModuleJSON{mainMod, r.dummyVendorMod}
- } else {
- // Vendor mode is off, so run go list -m ... to find everything.
- r.initAllMods()
- }
-
- if gmc := r.env.Env["GOMODCACHE"]; gmc != "" {
- r.moduleCacheDir = gmc
- } else {
- r.moduleCacheDir = filepath.Join(filepath.SplitList(goenv["GOPATH"])[0], "/pkg/mod")
- }
-
- sort.Slice(r.modsByModPath, func(i, j int) bool {
- count := func(x int) int {
- return strings.Count(r.modsByModPath[x].Path, "/")
- }
- return count(j) < count(i) // descending order
- })
- sort.Slice(r.modsByDir, func(i, j int) bool {
- count := func(x int) int {
- return strings.Count(r.modsByDir[x].Dir, "/")
- }
- return count(j) < count(i) // descending order
- })
-
- r.roots = []gopathwalk.Root{
- {filepath.Join(goenv["GOROOT"], "/src"), gopathwalk.RootGOROOT},
- }
- if r.main != nil {
- r.roots = append(r.roots, gopathwalk.Root{r.main.Dir, gopathwalk.RootCurrentModule})
- }
- if vendorEnabled {
- r.roots = append(r.roots, gopathwalk.Root{r.dummyVendorMod.Dir, gopathwalk.RootOther})
- } else {
- addDep := func(mod *gocommand.ModuleJSON) {
- if mod.Replace == nil {
- // This is redundant with the cache, but we'll skip it cheaply enough.
- r.roots = append(r.roots, gopathwalk.Root{mod.Dir, gopathwalk.RootModuleCache})
- } else {
- r.roots = append(r.roots, gopathwalk.Root{mod.Dir, gopathwalk.RootOther})
- }
- }
- // Walk dependent modules before scanning the full mod cache, direct deps first.
- for _, mod := range r.modsByModPath {
- if !mod.Indirect && !mod.Main {
- addDep(mod)
- }
- }
- for _, mod := range r.modsByModPath {
- if mod.Indirect && !mod.Main {
- addDep(mod)
- }
- }
- r.roots = append(r.roots, gopathwalk.Root{r.moduleCacheDir, gopathwalk.RootModuleCache})
- }
-
- r.scannedRoots = map[gopathwalk.Root]bool{}
- if r.moduleCacheCache == nil {
- r.moduleCacheCache = &dirInfoCache{
- dirs: map[string]*directoryPackageInfo{},
- listeners: map[*int]cacheListener{},
- }
- }
- if r.otherCache == nil {
- r.otherCache = &dirInfoCache{
- dirs: map[string]*directoryPackageInfo{},
- listeners: map[*int]cacheListener{},
- }
- }
- r.initialized = true
- return nil
- }
-
- func (r *ModuleResolver) initAllMods() error {
- stdout, err := r.env.invokeGo(context.TODO(), "list", "-m", "-json", "...")
- if err != nil {
- return err
- }
- for dec := json.NewDecoder(stdout); dec.More(); {
- mod := &gocommand.ModuleJSON{}
- if err := dec.Decode(mod); err != nil {
- return err
- }
- if mod.Dir == "" {
- if r.env.Logf != nil {
- r.env.Logf("module %v has not been downloaded and will be ignored", mod.Path)
- }
- // Can't do anything with a module that's not downloaded.
- continue
- }
- // golang/go#36193: the go command doesn't always clean paths.
- mod.Dir = filepath.Clean(mod.Dir)
- r.modsByModPath = append(r.modsByModPath, mod)
- r.modsByDir = append(r.modsByDir, mod)
- if mod.Main {
- r.main = mod
- }
- }
- return nil
- }
-
- func (r *ModuleResolver) ClearForNewScan() {
- <-r.scanSema
- r.scannedRoots = map[gopathwalk.Root]bool{}
- r.otherCache = &dirInfoCache{
- dirs: map[string]*directoryPackageInfo{},
- listeners: map[*int]cacheListener{},
- }
- r.scanSema <- struct{}{}
- }
-
- func (r *ModuleResolver) ClearForNewMod() {
- <-r.scanSema
- *r = ModuleResolver{
- env: r.env,
- moduleCacheCache: r.moduleCacheCache,
- otherCache: r.otherCache,
- scanSema: r.scanSema,
- }
- r.init()
- r.scanSema <- struct{}{}
- }
-
- // findPackage returns the module and directory that contains the package at
- // the given import path, or returns nil, "" if no module is in scope.
- func (r *ModuleResolver) findPackage(importPath string) (*gocommand.ModuleJSON, string) {
- // This can't find packages in the stdlib, but that's harmless for all
- // the existing code paths.
- for _, m := range r.modsByModPath {
- if !strings.HasPrefix(importPath, m.Path) {
- continue
- }
- pathInModule := importPath[len(m.Path):]
- pkgDir := filepath.Join(m.Dir, pathInModule)
- if r.dirIsNestedModule(pkgDir, m) {
- continue
- }
-
- if info, ok := r.cacheLoad(pkgDir); ok {
- if loaded, err := info.reachedStatus(nameLoaded); loaded {
- if err != nil {
- continue // No package in this dir.
- }
- return m, pkgDir
- }
- if scanned, err := info.reachedStatus(directoryScanned); scanned && err != nil {
- continue // Dir is unreadable, etc.
- }
- // This is slightly wrong: a directory doesn't have to have an
- // importable package to count as a package for package-to-module
- // resolution. package main or _test files should count but
- // don't.
- // TODO(heschi): fix this.
- if _, err := r.cachePackageName(info); err == nil {
- return m, pkgDir
- }
- }
-
- // Not cached. Read the filesystem.
- pkgFiles, err := ioutil.ReadDir(pkgDir)
- if err != nil {
- continue
- }
- // A module only contains a package if it has buildable go
- // files in that directory. If not, it could be provided by an
- // outer module. See #29736.
- for _, fi := range pkgFiles {
- if ok, _ := r.env.matchFile(pkgDir, fi.Name()); ok {
- return m, pkgDir
- }
- }
- }
- return nil, ""
- }
-
- func (r *ModuleResolver) cacheLoad(dir string) (directoryPackageInfo, bool) {
- if info, ok := r.moduleCacheCache.Load(dir); ok {
- return info, ok
- }
- return r.otherCache.Load(dir)
- }
-
- func (r *ModuleResolver) cacheStore(info directoryPackageInfo) {
- if info.rootType == gopathwalk.RootModuleCache {
- r.moduleCacheCache.Store(info.dir, info)
- } else {
- r.otherCache.Store(info.dir, info)
- }
- }
-
- func (r *ModuleResolver) cacheKeys() []string {
- return append(r.moduleCacheCache.Keys(), r.otherCache.Keys()...)
- }
-
- // cachePackageName caches the package name for a dir already in the cache.
- func (r *ModuleResolver) cachePackageName(info directoryPackageInfo) (string, error) {
- if info.rootType == gopathwalk.RootModuleCache {
- return r.moduleCacheCache.CachePackageName(info)
- }
- return r.otherCache.CachePackageName(info)
- }
-
- func (r *ModuleResolver) cacheExports(ctx context.Context, env *ProcessEnv, info directoryPackageInfo) (string, []string, error) {
- if info.rootType == gopathwalk.RootModuleCache {
- return r.moduleCacheCache.CacheExports(ctx, env, info)
- }
- return r.otherCache.CacheExports(ctx, env, info)
- }
-
- // findModuleByDir returns the module that contains dir, or nil if no such
- // module is in scope.
- func (r *ModuleResolver) findModuleByDir(dir string) *gocommand.ModuleJSON {
- // This is quite tricky and may not be correct. dir could be:
- // - a package in the main module.
- // - a replace target underneath the main module's directory.
- // - a nested module in the above.
- // - a replace target somewhere totally random.
- // - a nested module in the above.
- // - in the mod cache.
- // - in /vendor/ in -mod=vendor mode.
- // - nested module? Dunno.
- // Rumor has it that replace targets cannot contain other replace targets.
- for _, m := range r.modsByDir {
- if !strings.HasPrefix(dir, m.Dir) {
- continue
- }
-
- if r.dirIsNestedModule(dir, m) {
- continue
- }
-
- return m
- }
- return nil
- }
-
- // dirIsNestedModule reports if dir is contained in a nested module underneath
- // mod, not actually in mod.
- func (r *ModuleResolver) dirIsNestedModule(dir string, mod *gocommand.ModuleJSON) bool {
- if !strings.HasPrefix(dir, mod.Dir) {
- return false
- }
- if r.dirInModuleCache(dir) {
- // Nested modules in the module cache are pruned,
- // so it cannot be a nested module.
- return false
- }
- if mod != nil && mod == r.dummyVendorMod {
- // The /vendor pseudomodule is flattened and doesn't actually count.
- return false
- }
- modDir, _ := r.modInfo(dir)
- if modDir == "" {
- return false
- }
- return modDir != mod.Dir
- }
-
- func (r *ModuleResolver) modInfo(dir string) (modDir string, modName string) {
- readModName := func(modFile string) string {
- modBytes, err := ioutil.ReadFile(modFile)
- if err != nil {
- return ""
- }
- return modulePath(modBytes)
- }
-
- if r.dirInModuleCache(dir) {
- matches := modCacheRegexp.FindStringSubmatch(dir)
- index := strings.Index(dir, matches[1]+"@"+matches[2])
- modDir := filepath.Join(dir[:index], matches[1]+"@"+matches[2])
- return modDir, readModName(filepath.Join(modDir, "go.mod"))
- }
- for {
- if info, ok := r.cacheLoad(dir); ok {
- return info.moduleDir, info.moduleName
- }
- f := filepath.Join(dir, "go.mod")
- info, err := os.Stat(f)
- if err == nil && !info.IsDir() {
- return dir, readModName(f)
- }
-
- d := filepath.Dir(dir)
- if len(d) >= len(dir) {
- return "", "" // reached top of file system, no go.mod
- }
- dir = d
- }
- }
-
- func (r *ModuleResolver) dirInModuleCache(dir string) bool {
- if r.moduleCacheDir == "" {
- return false
- }
- return strings.HasPrefix(dir, r.moduleCacheDir)
- }
-
- func (r *ModuleResolver) loadPackageNames(importPaths []string, srcDir string) (map[string]string, error) {
- if err := r.init(); err != nil {
- return nil, err
- }
- names := map[string]string{}
- for _, path := range importPaths {
- _, packageDir := r.findPackage(path)
- if packageDir == "" {
- continue
- }
- name, err := packageDirToName(packageDir)
- if err != nil {
- continue
- }
- names[path] = name
- }
- return names, nil
- }
-
- func (r *ModuleResolver) scan(ctx context.Context, callback *scanCallback) error {
- if err := r.init(); err != nil {
- return err
- }
-
- processDir := func(info directoryPackageInfo) {
- // Skip this directory if we were not able to get the package information successfully.
- if scanned, err := info.reachedStatus(directoryScanned); !scanned || err != nil {
- return
- }
- pkg, err := r.canonicalize(info)
- if err != nil {
- return
- }
-
- if !callback.dirFound(pkg) {
- return
- }
- pkg.packageName, err = r.cachePackageName(info)
- if err != nil {
- return
- }
-
- if !callback.packageNameLoaded(pkg) {
- return
- }
- _, exports, err := r.loadExports(ctx, pkg, false)
- if err != nil {
- return
- }
- callback.exportsLoaded(pkg, exports)
- }
-
- // Start processing everything in the cache, and listen for the new stuff
- // we discover in the walk below.
- stop1 := r.moduleCacheCache.ScanAndListen(ctx, processDir)
- defer stop1()
- stop2 := r.otherCache.ScanAndListen(ctx, processDir)
- defer stop2()
-
- // We assume cached directories are fully cached, including all their
- // children, and have not changed. We can skip them.
- skip := func(root gopathwalk.Root, dir string) bool {
- info, ok := r.cacheLoad(dir)
- if !ok {
- return false
- }
- // This directory can be skipped as long as we have already scanned it.
- // Packages with errors will continue to have errors, so there is no need
- // to rescan them.
- packageScanned, _ := info.reachedStatus(directoryScanned)
- return packageScanned
- }
-
- // Add anything new to the cache, and process it if we're still listening.
- add := func(root gopathwalk.Root, dir string) {
- r.cacheStore(r.scanDirForPackage(root, dir))
- }
-
- // r.roots and the callback are not necessarily safe to use in the
- // goroutine below. Process them eagerly.
- roots := filterRoots(r.roots, callback.rootFound)
- // We can't cancel walks, because we need them to finish to have a usable
- // cache. Instead, run them in a separate goroutine and detach.
- scanDone := make(chan struct{})
- go func() {
- select {
- case <-ctx.Done():
- return
- case <-r.scanSema:
- }
- defer func() { r.scanSema <- struct{}{} }()
- // We have the lock on r.scannedRoots, and no other scans can run.
- for _, root := range roots {
- if ctx.Err() != nil {
- return
- }
-
- if r.scannedRoots[root] {
- continue
- }
- gopathwalk.WalkSkip([]gopathwalk.Root{root}, add, skip, gopathwalk.Options{Logf: r.env.Logf, ModulesEnabled: true})
- r.scannedRoots[root] = true
- }
- close(scanDone)
- }()
- select {
- case <-ctx.Done():
- case <-scanDone:
- }
- return nil
- }
-
- func (r *ModuleResolver) scoreImportPath(ctx context.Context, path string) int {
- if _, ok := stdlib[path]; ok {
- return MaxRelevance
- }
- mod, _ := r.findPackage(path)
- return modRelevance(mod)
- }
-
- func modRelevance(mod *gocommand.ModuleJSON) int {
- switch {
- case mod == nil: // out of scope
- return MaxRelevance - 4
- case mod.Indirect:
- return MaxRelevance - 3
- case !mod.Main:
- return MaxRelevance - 2
- default:
- return MaxRelevance - 1 // main module ties with stdlib
- }
- }
-
- // canonicalize gets the result of canonicalizing the packages using the results
- // of initializing the resolver from 'go list -m'.
- func (r *ModuleResolver) canonicalize(info directoryPackageInfo) (*pkg, error) {
- // Packages in GOROOT are already canonical, regardless of the std/cmd modules.
- if info.rootType == gopathwalk.RootGOROOT {
- return &pkg{
- importPathShort: info.nonCanonicalImportPath,
- dir: info.dir,
- packageName: path.Base(info.nonCanonicalImportPath),
- relevance: MaxRelevance,
- }, nil
- }
-
- importPath := info.nonCanonicalImportPath
- mod := r.findModuleByDir(info.dir)
- // Check if the directory is underneath a module that's in scope.
- if mod != nil {
- // It is. If dir is the target of a replace directive,
- // our guessed import path is wrong. Use the real one.
- if mod.Dir == info.dir {
- importPath = mod.Path
- } else {
- dirInMod := info.dir[len(mod.Dir)+len("/"):]
- importPath = path.Join(mod.Path, filepath.ToSlash(dirInMod))
- }
- } else if !strings.HasPrefix(importPath, info.moduleName) {
- // The module's name doesn't match the package's import path. It
- // probably needs a replace directive we don't have.
- return nil, fmt.Errorf("package in %q is not valid without a replace statement", info.dir)
- }
-
- res := &pkg{
- importPathShort: importPath,
- dir: info.dir,
- relevance: modRelevance(mod),
- }
- // We may have discovered a package that has a different version
- // in scope already. Canonicalize to that one if possible.
- if _, canonicalDir := r.findPackage(importPath); canonicalDir != "" {
- res.dir = canonicalDir
- }
- return res, nil
- }
-
- func (r *ModuleResolver) loadExports(ctx context.Context, pkg *pkg, includeTest bool) (string, []string, error) {
- if err := r.init(); err != nil {
- return "", nil, err
- }
- if info, ok := r.cacheLoad(pkg.dir); ok && !includeTest {
- return r.cacheExports(ctx, r.env, info)
- }
- return loadExportsFromFiles(ctx, r.env, pkg.dir, includeTest)
- }
-
- func (r *ModuleResolver) scanDirForPackage(root gopathwalk.Root, dir string) directoryPackageInfo {
- subdir := ""
- if dir != root.Path {
- subdir = dir[len(root.Path)+len("/"):]
- }
- importPath := filepath.ToSlash(subdir)
- if strings.HasPrefix(importPath, "vendor/") {
- // Only enter vendor directories if they're explicitly requested as a root.
- return directoryPackageInfo{
- status: directoryScanned,
- err: fmt.Errorf("unwanted vendor directory"),
- }
- }
- switch root.Type {
- case gopathwalk.RootCurrentModule:
- importPath = path.Join(r.main.Path, filepath.ToSlash(subdir))
- case gopathwalk.RootModuleCache:
- matches := modCacheRegexp.FindStringSubmatch(subdir)
- if len(matches) == 0 {
- return directoryPackageInfo{
- status: directoryScanned,
- err: fmt.Errorf("invalid module cache path: %v", subdir),
- }
- }
- modPath, err := module.UnescapePath(filepath.ToSlash(matches[1]))
- if err != nil {
- if r.env.Logf != nil {
- r.env.Logf("decoding module cache path %q: %v", subdir, err)
- }
- return directoryPackageInfo{
- status: directoryScanned,
- err: fmt.Errorf("decoding module cache path %q: %v", subdir, err),
- }
- }
- importPath = path.Join(modPath, filepath.ToSlash(matches[3]))
- }
-
- modDir, modName := r.modInfo(dir)
- result := directoryPackageInfo{
- status: directoryScanned,
- dir: dir,
- rootType: root.Type,
- nonCanonicalImportPath: importPath,
- moduleDir: modDir,
- moduleName: modName,
- }
- if root.Type == gopathwalk.RootGOROOT {
- // stdlib packages are always in scope, despite the confusing go.mod
- return result
- }
- return result
- }
-
- // modCacheRegexp splits a path in a module cache into module, module version, and package.
- var modCacheRegexp = regexp.MustCompile(`(.*)@([^/\\]*)(.*)`)
-
- var (
- slashSlash = []byte("//")
- moduleStr = []byte("module")
- )
-
- // modulePath returns the module path from the gomod file text.
- // If it cannot find a module path, it returns an empty string.
- // It is tolerant of unrelated problems in the go.mod file.
- //
- // Copied from cmd/go/internal/modfile.
- func modulePath(mod []byte) string {
- for len(mod) > 0 {
- line := mod
- mod = nil
- if i := bytes.IndexByte(line, '\n'); i >= 0 {
- line, mod = line[:i], line[i+1:]
- }
- if i := bytes.Index(line, slashSlash); i >= 0 {
- line = line[:i]
- }
- line = bytes.TrimSpace(line)
- if !bytes.HasPrefix(line, moduleStr) {
- continue
- }
- line = line[len(moduleStr):]
- n := len(line)
- line = bytes.TrimSpace(line)
- if len(line) == n || len(line) == 0 {
- continue
- }
-
- if line[0] == '"' || line[0] == '`' {
- p, err := strconv.Unquote(string(line))
- if err != nil {
- return "" // malformed quoted string or multiline module path
- }
- return p
- }
-
- return string(line)
- }
- return "" // missing module path
- }
|