blob: 0f9b87eb7331ee28004bbfc49924958632b7ca14 [file] [log] [blame]
package imports
import (
"bytes"
"context"
"encoding/json"
"fmt"
"io/ioutil"
"os"
"path"
"path/filepath"
"regexp"
"sort"
"strconv"
"strings"
"sync"
"golang.org/x/tools/internal/gopathwalk"
"golang.org/x/tools/internal/module"
"golang.org/x/tools/internal/semver"
)
// ModuleResolver implements resolver for modules using the go command as little
// as feasible.
type ModuleResolver struct {
env *ProcessEnv
moduleCacheDir string
dummyVendorMod *ModuleJSON // If vendoring is enabled, the pseudo-module that represents the /vendor directory.
Initialized bool
Main *ModuleJSON
ModsByModPath []*ModuleJSON // All modules, ordered by # of path components in module Path...
ModsByDir []*ModuleJSON // ...or Dir.
// moduleCacheCache stores information about the module cache.
moduleCacheCache *dirInfoCache
otherCache *dirInfoCache
}
type ModuleJSON struct {
Path string // module path
Replace *ModuleJSON // replaced by this module
Main bool // is this the main module?
Dir string // directory holding files for this module, if any
GoMod string // path to go.mod file for this module, if any
GoVersion string // go version used in module
}
func (r *ModuleResolver) init() error {
if r.Initialized {
return nil
}
mainMod, vendorEnabled, err := vendorEnabled(r.env)
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 = &ModuleJSON{
Path: "",
Dir: filepath.Join(mainMod.Dir, "vendor"),
}
r.ModsByModPath = []*ModuleJSON{mainMod, r.dummyVendorMod}
r.ModsByDir = []*ModuleJSON{mainMod, r.dummyVendorMod}
} else {
// Vendor mode is off, so run go list -m ... to find everything.
r.initAllMods()
}
r.moduleCacheDir = filepath.Join(filepath.SplitList(r.env.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
})
if r.moduleCacheCache == nil {
r.moduleCacheCache = &dirInfoCache{
dirs: map[string]*directoryPackageInfo{},
}
}
if r.otherCache == nil {
r.otherCache = &dirInfoCache{
dirs: map[string]*directoryPackageInfo{},
}
}
r.Initialized = true
return nil
}
func (r *ModuleResolver) initAllMods() error {
stdout, err := r.env.invokeGo("list", "-m", "-json", "...")
if err != nil {
return err
}
for dec := json.NewDecoder(stdout); dec.More(); {
mod := &ModuleJSON{}
if err := dec.Decode(mod); err != nil {
return err
}
if mod.Dir == "" {
if r.env.Debug {
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
}
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.otherCache = &dirInfoCache{
dirs: map[string]*directoryPackageInfo{},
}
}
func (r *ModuleResolver) ClearForNewMod() {
env := r.env
*r = ModuleResolver{
env: env,
}
r.init()
}
// 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) (*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.buildContext().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) (directoryPackageInfo, 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) *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 *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(_ references, loadNames bool, exclude []gopathwalk.RootType) ([]*pkg, error) {
if err := r.init(); err != nil {
return nil, err
}
// Walk GOROOT, GOPATH/pkg/mod, and the main module.
roots := []gopathwalk.Root{
{filepath.Join(r.env.GOROOT, "/src"), gopathwalk.RootGOROOT},
}
if r.Main != nil {
roots = append(roots, gopathwalk.Root{r.Main.Dir, gopathwalk.RootCurrentModule})
}
if r.dummyVendorMod != nil {
roots = append(roots, gopathwalk.Root{r.dummyVendorMod.Dir, gopathwalk.RootOther})
} else {
roots = append(roots, gopathwalk.Root{r.moduleCacheDir, gopathwalk.RootModuleCache})
// Walk replace targets, just in case they're not in any of the above.
for _, mod := range r.ModsByModPath {
if mod.Replace != nil {
roots = append(roots, gopathwalk.Root{mod.Dir, gopathwalk.RootOther})
}
}
}
roots = filterRoots(roots, exclude)
var result []*pkg
var mu sync.Mutex
// We assume cached directories have not changed. We can skip them and their
// children.
skip := func(root gopathwalk.Root, dir string) bool {
mu.Lock()
defer mu.Unlock()
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. We'll process everything in it below.
add := func(root gopathwalk.Root, dir string) {
mu.Lock()
defer mu.Unlock()
r.cacheStore(r.scanDirForPackage(root, dir))
}
gopathwalk.WalkSkip(roots, add, skip, gopathwalk.Options{Debug: r.env.Debug, ModulesEnabled: true})
// Everything we already had, and everything new, is now in the cache.
for _, dir := range r.cacheKeys() {
info, ok := r.cacheLoad(dir)
if !ok {
continue
}
// Skip this directory if we were not able to get the package information successfully.
if scanned, err := info.reachedStatus(directoryScanned); !scanned || err != nil {
continue
}
// If we want package names, make sure the cache has them.
if loadNames {
var err error
if info, err = r.cachePackageName(info); err != nil {
continue
}
}
res, err := r.canonicalize(info)
if err != nil {
continue
}
result = append(result, res)
}
return result, nil
}
// 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: 0,
}, nil
}
importPath := info.nonCanonicalImportPath
relevance := 2
// Check if the directory is underneath a module that's in scope.
if mod := r.findModuleByDir(info.dir); mod != nil {
relevance = 1
// 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 info.needsReplace {
return nil, fmt.Errorf("package in %q is not valid without a replace statement", info.dir)
}
res := &pkg{
importPathShort: importPath,
dir: info.dir,
packageName: info.packageName, // may not be populated if the caller didn't ask for it
relevance: relevance,
}
// 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) (string, []string, error) {
if err := r.init(); err != nil {
return "", nil, err
}
if info, ok := r.cacheLoad(pkg.dir); ok {
return r.cacheExports(ctx, r.env, info)
}
return loadExportsFromFiles(ctx, r.env, pkg.dir)
}
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.DecodePath(filepath.ToSlash(matches[1]))
if err != nil {
if r.env.Debug {
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,
needsReplace: false,
moduleDir: modDir,
moduleName: modName,
}
if root.Type == gopathwalk.RootGOROOT {
// stdlib packages are always in scope, despite the confusing go.mod
return result
}
// Check that this package is not obviously impossible to import.
if !strings.HasPrefix(importPath, modName) {
// The module's declared path does not match
// its expected path. It probably needs a
// replace directive we don't have.
result.needsReplace = true
}
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
}
var modFlagRegexp = regexp.MustCompile(`-mod[ =](\w+)`)
// vendorEnabled indicates if vendoring is enabled.
// Inspired by setDefaultBuildMod in modload/init.go
func vendorEnabled(env *ProcessEnv) (*ModuleJSON, bool, error) {
mainMod, go114, err := getMainModuleAnd114(env)
if err != nil {
return nil, false, err
}
matches := modFlagRegexp.FindStringSubmatch(env.GOFLAGS)
var modFlag string
if len(matches) != 0 {
modFlag = matches[1]
}
if modFlag != "" {
// Don't override an explicit '-mod=' argument.
return mainMod, modFlag == "vendor", nil
}
if mainMod == nil || !go114 {
return mainMod, false, nil
}
// Check 1.14's automatic vendor mode.
if fi, err := os.Stat(filepath.Join(mainMod.Dir, "vendor")); err == nil && fi.IsDir() {
if mainMod.GoVersion != "" && semver.Compare("v"+mainMod.GoVersion, "v1.14") >= 0 {
// The Go version is at least 1.14, and a vendor directory exists.
// Set -mod=vendor by default.
return mainMod, true, nil
}
}
return mainMod, false, nil
}
// getMainModuleAnd114 gets the main module's information and whether the
// go command in use is 1.14+. This is the information needed to figure out
// if vendoring should be enabled.
func getMainModuleAnd114(env *ProcessEnv) (*ModuleJSON, bool, error) {
const format = `{{.Path}}
{{.Dir}}
{{.GoMod}}
{{.GoVersion}}
{{range context.ReleaseTags}}{{if eq . "go1.14"}}{{.}}{{end}}{{end}}
`
stdout, err := env.invokeGo("list", "-m", "-f", format)
if err != nil {
return nil, false, nil
}
lines := strings.Split(stdout.String(), "\n")
if len(lines) < 5 {
return nil, false, fmt.Errorf("unexpected stdout: %q", stdout)
}
mod := &ModuleJSON{
Path: lines[0],
Dir: lines[1],
GoMod: lines[2],
GoVersion: lines[3],
Main: true,
}
return mod, lines[4] == "go1.14", nil
}