Updated dependencies

vendor/golang.org/x/tools/go/packages/golist.go

@@ -283,7 +283,10 @@ func runNamedQueries(cfg *Config, driver driver, response *responseDeduper, quer
 		matchesMu.Lock()
 		defer matchesMu.Unlock()
 
-		path := dir[len(root.Path)+1:]
+		path := dir
+		if dir != root.Path {
+			path = dir[len(root.Path)+1:]
+		}
 		if pathMatchesQueries(path, queries) {
 			switch root.Type {
 			case gopathwalk.RootModuleCache:

vendor/golang.org/x/tools/go/packages/packages.go

@@ -773,6 +773,11 @@ func (ld *loader) parseFiles(filenames []string) ([]*ast.File, []error) {
 	parsed := make([]*ast.File, n)
 	errors := make([]error, n)
 	for i, file := range filenames {
+		if ld.Config.Context.Err() != nil {
+			parsed[i] = nil
+			errors[i] = ld.Config.Context.Err()
+			continue
+		}
 		wg.Add(1)
 		go func(i int, filename string) {
 			ioLimit <- true // wait

vendor/golang.org/x/tools/imports/fix.go

@@ -22,6 +22,7 @@ import (
 	"strconv"
 	"strings"
 	"sync"
+	"time"
 
 	"golang.org/x/tools/go/ast/astutil"
 	"golang.org/x/tools/go/packages"
@@ -142,8 +143,8 @@ func addGlobals(f *ast.File, globals map[string]bool) {
 
 // collectReferences builds a map of selector expressions, from
 // left hand side (X) to a set of right hand sides (Sel).
-func collectReferences(f *ast.File) map[string]map[string]bool {
-	refs := map[string]map[string]bool{}
+func collectReferences(f *ast.File) references {
+	refs := references{}
 
 	var visitor visitFn
 	visitor = func(node ast.Node) ast.Visitor {
@@ -226,6 +227,11 @@ func (p *pass) findMissingImport(pkg string, syms map[string]bool) *importInfo {
 	return nil
 }
 
+// references is set of references found in a Go file. The first map key is the
+// left hand side of a selector expression, the second key is the right hand
+// side, and the value should always be true.
+type references map[string]map[string]bool
+
 // A pass contains all the inputs and state necessary to fix a file's imports.
 // It can be modified in some ways during use; see comments below.
 type pass struct {
@@ -239,8 +245,8 @@ type pass struct {
 
 	// Intermediate state, generated by load.
 	existingImports map[string]*importInfo
-	allRefs         map[string]map[string]bool
-	missingRefs     map[string]map[string]bool
+	allRefs         references
+	missingRefs     references
 
 	// Inputs to fix. These can be augmented between successive fix calls.
 	lastTry       bool                    // indicates that this is the last call and fix should clean up as best it can.
@@ -258,28 +264,14 @@ func (p *pass) loadPackageNames(imports []*importInfo) error {
 		unknown = append(unknown, imp.importPath)
 	}
 
-	if !p.fixEnv.shouldUseGoPackages() {
-		for _, path := range unknown {
-			name := importPathToName(p.fixEnv, path, p.srcDir)
-			if name == "" {
-				continue
-			}
-			p.knownPackages[path] = &packageInfo{
-				name:    name,
-				exports: map[string]bool{},
-			}
-		}
-		return nil
-	}
-
-	cfg := p.fixEnv.newPackagesConfig(packages.LoadFiles)
-	pkgs, err := packages.Load(cfg, unknown...)
+	names, err := p.fixEnv.getResolver().loadPackageNames(unknown, p.srcDir)
 	if err != nil {
 		return err
 	}
-	for _, pkg := range pkgs {
-		p.knownPackages[VendorlessPath(pkg.PkgPath)] = &packageInfo{
-			name:    pkg.Name,
+
+	for path, name := range names {
+		p.knownPackages[path] = &packageInfo{
+			name:    name,
 			exports: map[string]bool{},
 		}
 	}
@@ -305,7 +297,7 @@ func (p *pass) importIdentifier(imp *importInfo) string {
 // file's missing symbols, if any, or removes unused imports if not.
 func (p *pass) load() bool {
 	p.knownPackages = map[string]*packageInfo{}
-	p.missingRefs = map[string]map[string]bool{}
+	p.missingRefs = references{}
 	p.existingImports = map[string]*importInfo{}
 
 	// Load basic information about the file in question.
@@ -328,8 +320,12 @@ func (p *pass) load() bool {
 	// f's imports by the identifier they introduce.
 	imports := collectImports(p.f)
 	if p.loadRealPackageNames {
-		if err := p.loadPackageNames(append(imports, p.candidates...)); err != nil {
-			panic(err)
+		err := p.loadPackageNames(append(imports, p.candidates...))
+		if err != nil {
+			if Debug {
+				log.Printf("loading package names: %v", err)
+			}
+			return false
 		}
 	}
 	for _, imp := range imports {
@@ -464,7 +460,7 @@ func fixImportsDefault(fset *token.FileSet, f *ast.File, filename string, env *f
 	// derive package names from import paths, see if the file is already
 	// complete. We can't add any imports yet, because we don't know
 	// if missing references are actually package vars.
-	p := &pass{fset: fset, f: f, srcDir: srcDir, fixEnv: env}
+	p := &pass{fset: fset, f: f, srcDir: srcDir}
 	if p.load() {
 		return nil
 	}
@@ -473,7 +469,6 @@ func fixImportsDefault(fset *token.FileSet, f *ast.File, filename string, env *f
 
 	// Second pass: add information from other files in the same package,
 	// like their package vars and imports.
-	p = &pass{fset: fset, f: f, srcDir: srcDir, fixEnv: env}
 	p.otherFiles = otherFiles
 	if p.load() {
 		return nil
@@ -487,7 +482,8 @@ func fixImportsDefault(fset *token.FileSet, f *ast.File, filename string, env *f
 	}
 
 	// Third pass: get real package names where we had previously used
-	// the naive algorithm.
+	// the naive algorithm. This is the first step that will use the
+	// environment, so we provide it here for the first time.
 	p = &pass{fset: fset, f: f, srcDir: srcDir, fixEnv: env}
 	p.loadRealPackageNames = true
 	p.otherFiles = otherFiles
@@ -517,14 +513,13 @@ func fixImportsDefault(fset *token.FileSet, f *ast.File, filename string, env *f
 type fixEnv struct {
 	// If non-empty, these will be used instead of the
 	// process-wide values.
-	GOPATH, GOROOT, GO111MODULE string
-	WorkingDir                  string
+	GOPATH, GOROOT, GO111MODULE, GOPROXY, GOFLAGS string
+	WorkingDir                                    string
 
 	// If true, use go/packages regardless of the environment.
 	ForceGoPackages bool
 
-	ranGoEnv bool
-	gomod    string
+	resolver resolver
 }
 
 func (e *fixEnv) env() []string {
@@ -537,26 +532,27 @@ func (e *fixEnv) env() []string {
 	add("GOPATH", e.GOPATH)
 	add("GOROOT", e.GOROOT)
 	add("GO111MODULE", e.GO111MODULE)
+	add("GOPROXY", e.GOPROXY)
+	add("GOFLAGS", e.GOFLAGS)
+	if e.WorkingDir != "" {
+		add("PWD", e.WorkingDir)
+	}
 	return env
 }
 
-func (e *fixEnv) shouldUseGoPackages() bool {
+func (e *fixEnv) getResolver() resolver {
+	if e.resolver != nil {
+		return e.resolver
+	}
 	if e.ForceGoPackages {
-		return true
+		return &goPackagesResolver{env: e}
 	}
 
-	if !e.ranGoEnv {
-		e.ranGoEnv = true
-		cmd := exec.Command("go", "env", "GOMOD")
-		cmd.Dir = e.WorkingDir
-		cmd.Env = e.env()
-		out, err := cmd.Output()
-		if err != nil {
-			return false
-		}
-		e.gomod = string(bytes.TrimSpace(out))
+	out, err := e.invokeGo("env", "GOMOD")
+	if err != nil || len(bytes.TrimSpace(out.Bytes())) == 0 {
+		return &gopathResolver{env: e}
 	}
-	return e.gomod != ""
+	return &moduleResolver{env: e}
 }
 
 func (e *fixEnv) newPackagesConfig(mode packages.LoadMode) *packages.Config {
@@ -574,7 +570,36 @@ func (e *fixEnv) buildContext() *build.Context {
 	return &ctx
 }
 
-func addStdlibCandidates(pass *pass, refs map[string]map[string]bool) {
+func (e *fixEnv) invokeGo(args ...string) (*bytes.Buffer, error) {
+	cmd := exec.Command("go", args...)
+	stdout := &bytes.Buffer{}
+	stderr := &bytes.Buffer{}
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	cmd.Env = e.env()
+	cmd.Dir = e.WorkingDir
+
+	if Debug {
+		defer func(start time.Time) { log.Printf("%s for %v", time.Since(start), cmdDebugStr(cmd)) }(time.Now())
+	}
+	if err := cmd.Run(); err != nil {
+		return nil, fmt.Errorf("running go: %v (stderr:\n%s)", err, stderr)
+	}
+	return stdout, nil
+}
+
+func cmdDebugStr(cmd *exec.Cmd) string {
+	env := make(map[string]string)
+	for _, kv := range cmd.Env {
+		split := strings.Split(kv, "=")
+		k, v := split[0], split[1]
+		env[k] = v
+	}
+
+	return fmt.Sprintf("GOROOT=%v GOPATH=%v GO111MODULE=%v GOPROXY=%v PWD=%v go %v", env["GOROOT"], env["GOPATH"], env["GO111MODULE"], env["GOPROXY"], env["PWD"], cmd.Args)
+}
+
+func addStdlibCandidates(pass *pass, refs references) {
 	add := func(pkg string) {
 		pass.addCandidate(
 			&importInfo{importPath: pkg},
@@ -595,13 +620,47 @@ func addStdlibCandidates(pass *pass, refs map[string]map[string]bool) {
 	}
 }
 
-func scanGoPackages(env *fixEnv, refs map[string]map[string]bool) ([]*pkg, error) {
+// A resolver does the build-system-specific parts of goimports.
+type resolver interface {
+	// loadPackageNames loads the package names in importPaths.
+	loadPackageNames(importPaths []string, srcDir string) (map[string]string, error)
+	// scan finds (at least) the packages satisfying refs. The returned slice is unordered.
+	scan(refs references) ([]*pkg, error)
+}
+
+// gopathResolver implements resolver for GOPATH and module workspaces using go/packages.
+type goPackagesResolver struct {
+	env *fixEnv
+}
+
+func (r *goPackagesResolver) loadPackageNames(importPaths []string, srcDir string) (map[string]string, error) {
+	cfg := r.env.newPackagesConfig(packages.LoadFiles)
+	pkgs, err := packages.Load(cfg, importPaths...)
+	if err != nil {
+		return nil, err
+	}
+	names := map[string]string{}
+	for _, pkg := range pkgs {
+		names[VendorlessPath(pkg.PkgPath)] = pkg.Name
+	}
+	// We may not have found all the packages. Guess the rest.
+	for _, path := range importPaths {
+		if _, ok := names[path]; ok {
+			continue
+		}
+		names[path] = importPathToNameBasic(path, srcDir)
+	}
+	return names, nil
+
+}
+
+func (r *goPackagesResolver) scan(refs references) ([]*pkg, error) {
 	var loadQueries []string
 	for pkgName := range refs {
 		loadQueries = append(loadQueries, "name="+pkgName)
 	}
 	sort.Strings(loadQueries)
-	cfg := env.newPackagesConfig(packages.LoadFiles)
+	cfg := r.env.newPackagesConfig(packages.LoadFiles)
 	goPackages, err := packages.Load(cfg, loadQueries...)
 	if err != nil {
 		return nil, err
@@ -618,18 +677,10 @@ func scanGoPackages(env *fixEnv, refs map[string]map[string]bool) ([]*pkg, error
 	return scan, nil
 }
 
-var addExternalCandidates = addExternalCandidatesDefault
-
-func addExternalCandidatesDefault(pass *pass, refs map[string]map[string]bool, filename string) error {
-	var dirScan []*pkg
-	if pass.fixEnv.shouldUseGoPackages() {
-		var err error
-		dirScan, err = scanGoPackages(pass.fixEnv, refs)
-		if err != nil {
-			return err
-		}
-	} else {
-		dirScan = scanGoDirs(pass.fixEnv)
+func addExternalCandidates(pass *pass, refs references, filename string) error {
+	dirScan, err := pass.fixEnv.getResolver().scan(refs)
+	if err != nil {
+		return err
 	}
 
 	// Search for imports matching potential package references.
@@ -705,6 +756,19 @@ func importPathToNameBasic(importPath, srcDir string) (packageName string) {
 	return base
 }
 
+// gopathResolver implements resolver for GOPATH workspaces.
+type gopathResolver struct {
+	env *fixEnv
+}
+
+func (r *gopathResolver) loadPackageNames(importPaths []string, srcDir string) (map[string]string, error) {
+	names := map[string]string{}
+	for _, path := range importPaths {
+		names[path] = importPathToName(r.env, path, srcDir)
+	}
+	return names, nil
+}
+
 // importPathToNameGoPath finds out the actual package name, as declared in its .go files.
 // If there's a problem, it returns "".
 func importPathToName(env *fixEnv, importPath, srcDir string) (packageName string) {
@@ -713,26 +777,23 @@ func importPathToName(env *fixEnv, importPath, srcDir string) (packageName strin
 		return path.Base(importPath) // stdlib packages always match their paths.
 	}
 
-	pkgName, err := importPathToNameGoPathParse(env, importPath, srcDir)
-	if Debug {
-		log.Printf("importPathToNameGoPathParse(%q, srcDir=%q) = %q, %v", importPath, srcDir, pkgName, err)
+	buildPkg, err := env.buildContext().Import(importPath, srcDir, build.FindOnly)
+	if err != nil {
+		return ""
 	}
+	pkgName, err := packageDirToName(buildPkg.Dir)
 	if err != nil {
 		return ""
 	}
 	return pkgName
 }
 
-// importPathToNameGoPathParse is a faster version of build.Import if
+// packageDirToName is a faster version of build.Import if
 // the only thing desired is the package name. It uses build.FindOnly
 // to find the directory and then only parses one file in the package,
 // trusting that the files in the directory are consistent.
-func importPathToNameGoPathParse(env *fixEnv, importPath, srcDir string) (packageName string, err error) {
-	buildPkg, err := env.buildContext().Import(importPath, srcDir, build.FindOnly)
-	if err != nil {
-		return "", err
-	}
-	d, err := os.Open(buildPkg.Dir)
+func packageDirToName(dir string) (packageName string, err error) {
+	d, err := os.Open(dir)
 	if err != nil {
 		return "", err
 	}
@@ -752,7 +813,7 @@ func importPathToNameGoPathParse(env *fixEnv, importPath, srcDir string) (packag
 			continue
 		}
 		nfile++
-		fullFile := filepath.Join(buildPkg.Dir, name)
+		fullFile := filepath.Join(dir, name)
 
 		fset := token.NewFileSet()
 		f, err := parser.ParseFile(fset, fullFile, nil, parser.PackageClauseOnly)
@@ -826,8 +887,7 @@ func distance(basepath, targetpath string) int {
 	return strings.Count(p, string(filepath.Separator)) + 1
 }
 
-// scanGoDirs populates the dirScan map for GOPATH and GOROOT.
-func scanGoDirs(env *fixEnv) []*pkg {
+func (r *gopathResolver) scan(_ references) ([]*pkg, error) {
 	dupCheck := make(map[string]bool)
 	var result []*pkg
 
@@ -847,8 +907,8 @@ func scanGoDirs(env *fixEnv) []*pkg {
 			dir:             dir,
 		})
 	}
-	gopathwalk.Walk(gopathwalk.SrcDirsRoots(env.buildContext()), add, gopathwalk.Options{Debug: Debug, ModulesEnabled: false})
-	return result
+	gopathwalk.Walk(gopathwalk.SrcDirsRoots(r.env.buildContext()), add, gopathwalk.Options{Debug: Debug, ModulesEnabled: false})
+	return result, nil
 }
 
 // VendorlessPath returns the devendorized version of the import path ipath.

vendor/golang.org/x/tools/imports/mod.go

@@ -0,0 +1,351 @@
+package imports
+
+import (
+	"bytes"
+	"encoding/json"
+	"io/ioutil"
+	"log"
+	"os"
+	"path"
+	"path/filepath"
+	"regexp"
+	"sort"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/tools/internal/gopathwalk"
+	"golang.org/x/tools/internal/module"
+)
+
+// moduleResolver implements resolver for modules using the go command as little
+// as feasible.
+type moduleResolver struct {
+	env *fixEnv
+
+	main          *moduleJSON
+	modsByModPath []*moduleJSON // All modules, ordered by # of path components in module Path...
+	modsByDir     []*moduleJSON // ...or Dir.
+}
+
+type moduleJSON struct {
+	Path     string           // module path
+	Version  string           // module version
+	Versions []string         // available module versions (with -versions)
+	Replace  *moduleJSON      // replaced by this module
+	Time     *time.Time       // time version was created
+	Update   *moduleJSON      // available update, if any (with -u)
+	Main     bool             // is this the main module?
+	Indirect bool             // is this module only an indirect dependency of main module?
+	Dir      string           // directory holding files for this module, if any
+	GoMod    string           // path to go.mod file for this module, if any
+	Error    *moduleErrorJSON // error loading module
+}
+
+type moduleErrorJSON struct {
+	Err string // the error itself
+}
+
+func (r *moduleResolver) init() error {
+	if r.main != nil {
+		return nil
+	}
+	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 Debug {
+				log.Printf("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
+		}
+	}
+
+	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
+	})
+
+	return nil
+}
+
+// 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) {
+	for _, m := range r.modsByModPath {
+		if !strings.HasPrefix(importPath, m.Path) {
+			continue
+		}
+		pathInModule := importPath[len(m.Path):]
+		pkgDir := filepath.Join(m.Dir, pathInModule)
+		if dirIsNestedModule(pkgDir, m) {
+			continue
+		}
+
+		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, ""
+}
+
+// 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 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 dirIsNestedModule(dir string, mod *moduleJSON) bool {
+	if !strings.HasPrefix(dir, mod.Dir) {
+		return false
+	}
+	mf := findModFile(dir)
+	if mf == "" {
+		return false
+	}
+	return filepath.Dir(mf) != mod.Dir
+}
+
+func findModFile(dir string) string {
+	for {
+		f := filepath.Join(dir, "go.mod")
+		info, err := os.Stat(f)
+		if err == nil && !info.IsDir() {
+			return f
+		}
+		d := filepath.Dir(dir)
+		if len(d) >= len(dir) {
+			return "" // reached top of file system, no go.mod
+		}
+		dir = d
+	}
+}
+
+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) ([]*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},
+		{r.main.Dir, gopathwalk.RootCurrentModule},
+	}
+	for _, p := range filepath.SplitList(r.env.GOPATH) {
+		roots = append(roots, gopathwalk.Root{filepath.Join(p, "/pkg/mod"), 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})
+		}
+	}
+
+	var result []*pkg
+	dupCheck := make(map[string]bool)
+	var mu sync.Mutex
+
+	gopathwalk.Walk(roots, func(root gopathwalk.Root, dir string) {
+		mu.Lock()
+		defer mu.Unlock()
+
+		if _, dup := dupCheck[dir]; dup {
+			return
+		}
+
+		dupCheck[dir] = true
+
+		subdir := ""
+		if dir != root.Path {
+			subdir = dir[len(root.Path)+len("/"):]
+		}
+		importPath := filepath.ToSlash(subdir)
+		if strings.HasPrefix(importPath, "vendor/") {
+			// Ignore vendor dirs. If -mod=vendor is on, then things
+			// should mostly just work, but when it's not vendor/
+			// is a mess. There's no easy way to tell if it's on.
+			// We can still find things in the mod cache and
+			// map them into /vendor when -mod=vendor is on.
+			return
+		}
+		switch root.Type {
+		case gopathwalk.RootCurrentModule:
+			importPath = path.Join(r.main.Path, filepath.ToSlash(subdir))
+		case gopathwalk.RootModuleCache:
+			matches := modCacheRegexp.FindStringSubmatch(subdir)
+			modPath, err := module.DecodePath(filepath.ToSlash(matches[1]))
+			if err != nil {
+				if Debug {
+					log.Printf("decoding module cache path %q: %v", subdir, err)
+				}
+				return
+			}
+			importPath = path.Join(modPath, filepath.ToSlash(matches[3]))
+		case gopathwalk.RootGOROOT:
+			importPath = subdir
+		}
+
+		// Check if the directory is underneath a module that's in scope.
+		if mod := r.findModuleByDir(dir); 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 == dir {
+				importPath = mod.Path
+			} else {
+				dirInMod := dir[len(mod.Dir)+len("/"):]
+				importPath = path.Join(mod.Path, filepath.ToSlash(dirInMod))
+			}
+		} else {
+			// The package is in an unknown module. Check that it's
+			// not obviously impossible to import.
+			var modFile string
+			switch root.Type {
+			case gopathwalk.RootModuleCache:
+				matches := modCacheRegexp.FindStringSubmatch(subdir)
+				modFile = filepath.Join(matches[1], "@", matches[2], "go.mod")
+			default:
+				modFile = findModFile(dir)
+			}
+
+			modBytes, err := ioutil.ReadFile(modFile)
+			if err == nil && !strings.HasPrefix(importPath, modulePath(modBytes)) {
+				// The module's declared path does not match
+				// its expected path. It probably needs a
+				// replace directive we don't have.
+				return
+			}
+		}
+		// 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 != "" {
+			dir = canonicalDir
+		}
+
+		result = append(result, &pkg{
+			importPathShort: VendorlessPath(importPath),
+			dir:             dir,
+		})
+	}, gopathwalk.Options{Debug: Debug, ModulesEnabled: true})
+	return result, nil
+}
+
+// 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
+}

vendor/golang.org/x/tools/internal/gopathwalk/walk.go

@@ -35,6 +35,7 @@ const (
 	RootGOPATH
 	RootCurrentModule
 	RootModuleCache
+	RootOther
 )
 
 // A Root is a starting point for a Walk.
@@ -162,7 +163,7 @@ func (w *walker) shouldSkipDir(fi os.FileInfo) bool {
 func (w *walker) walk(path string, typ os.FileMode) error {
 	dir := filepath.Dir(path)
 	if typ.IsRegular() {
-		if dir == w.root.Path {
+		if dir == w.root.Path && (w.root.Type == RootGOROOT || w.root.Type == RootGOPATH) {
 			// Doesn't make sense to have regular files
 			// directly in your $GOPATH/src or $GOROOT/src.
 			return fastwalk.SkipFiles

vendor/golang.org/x/tools/internal/module/module.go

@@ -0,0 +1,540 @@
+// 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.
+
+// Package module defines the module.Version type
+// along with support code.
+package module
+
+// IMPORTANT NOTE
+//
+// This file essentially defines the set of valid import paths for the go command.
+// There are many subtle considerations, including Unicode ambiguity,
+// security, network, and file system representations.
+//
+// This file also defines the set of valid module path and version combinations,
+// another topic with many subtle considerations.
+//
+// Changes to the semantics in this file require approval from rsc.
+
+import (
+	"fmt"
+	"sort"
+	"strings"
+	"unicode"
+	"unicode/utf8"
+
+	"golang.org/x/tools/internal/semver"
+)
+
+// A Version is defined by a module path and version pair.
+type Version struct {
+	Path string
+
+	// Version is usually a semantic version in canonical form.
+	// There are two exceptions to this general rule.
+	// First, the top-level target of a build has no specific version
+	// and uses Version = "".
+	// Second, during MVS calculations the version "none" is used
+	// to represent the decision to take no version of a given module.
+	Version string `json:",omitempty"`
+}
+
+// Check checks that a given module path, version pair is valid.
+// In addition to the path being a valid module path
+// and the version being a valid semantic version,
+// the two must correspond.
+// For example, the path "yaml/v2" only corresponds to
+// semantic versions beginning with "v2.".
+func Check(path, version string) error {
+	if err := CheckPath(path); err != nil {
+		return err
+	}
+	if !semver.IsValid(version) {
+		return fmt.Errorf("malformed semantic version %v", version)
+	}
+	_, pathMajor, _ := SplitPathVersion(path)
+	if !MatchPathMajor(version, pathMajor) {
+		if pathMajor == "" {
+			pathMajor = "v0 or v1"
+		}
+		if pathMajor[0] == '.' { // .v1
+			pathMajor = pathMajor[1:]
+		}
+		return fmt.Errorf("mismatched module path %v and version %v (want %v)", path, version, pathMajor)
+	}
+	return nil
+}
+
+// firstPathOK reports whether r can appear in the first element of a module path.
+// The first element of the path must be an LDH domain name, at least for now.
+// To avoid case ambiguity, the domain name must be entirely lower case.
+func firstPathOK(r rune) bool {
+	return r == '-' || r == '.' ||
+		'0' <= r && r <= '9' ||
+		'a' <= r && r <= 'z'
+}
+
+// pathOK reports whether r can appear in an import path element.
+// Paths can be ASCII letters, ASCII digits, and limited ASCII punctuation: + - . _ and ~.
+// This matches what "go get" has historically recognized in import paths.
+// TODO(rsc): We would like to allow Unicode letters, but that requires additional
+// care in the safe encoding (see note below).
+func pathOK(r rune) bool {
+	if r < utf8.RuneSelf {
+		return r == '+' || r == '-' || r == '.' || r == '_' || r == '~' ||
+			'0' <= r && r <= '9' ||
+			'A' <= r && r <= 'Z' ||
+			'a' <= r && r <= 'z'
+	}
+	return false
+}
+
+// fileNameOK reports whether r can appear in a file name.
+// For now we allow all Unicode letters but otherwise limit to pathOK plus a few more punctuation characters.
+// If we expand the set of allowed characters here, we have to
+// work harder at detecting potential case-folding and normalization collisions.
+// See note about "safe encoding" below.
+func fileNameOK(r rune) bool {
+	if r < utf8.RuneSelf {
+		// Entire set of ASCII punctuation, from which we remove characters:
+		//     ! " # $ % & ' ( ) * + , - . / : ; < = > ? @ [ \ ] ^ _ ` { | } ~
+		// We disallow some shell special characters: " ' * < > ? ` |
+		// (Note that some of those are disallowed by the Windows file system as well.)
+		// We also disallow path separators / : and \ (fileNameOK is only called on path element characters).
+		// We allow spaces (U+0020) in file names.
+		const allowed = "!#$%&()+,-.=@[]^_{}~ "
+		if '0' <= r && r <= '9' || 'A' <= r && r <= 'Z' || 'a' <= r && r <= 'z' {
+			return true
+		}
+		for i := 0; i < len(allowed); i++ {
+			if rune(allowed[i]) == r {
+				return true
+			}
+		}
+		return false
+	}
+	// It may be OK to add more ASCII punctuation here, but only carefully.
+	// For example Windows disallows < > \, and macOS disallows :, so we must not allow those.
+	return unicode.IsLetter(r)
+}
+
+// CheckPath checks that a module path is valid.
+func CheckPath(path string) error {
+	if err := checkPath(path, false); err != nil {
+		return fmt.Errorf("malformed module path %q: %v", path, err)
+	}
+	i := strings.Index(path, "/")
+	if i < 0 {
+		i = len(path)
+	}
+	if i == 0 {
+		return fmt.Errorf("malformed module path %q: leading slash", path)
+	}
+	if !strings.Contains(path[:i], ".") {
+		return fmt.Errorf("malformed module path %q: missing dot in first path element", path)
+	}
+	if path[0] == '-' {
+		return fmt.Errorf("malformed module path %q: leading dash in first path element", path)
+	}
+	for _, r := range path[:i] {
+		if !firstPathOK(r) {
+			return fmt.Errorf("malformed module path %q: invalid char %q in first path element", path, r)
+		}
+	}
+	if _, _, ok := SplitPathVersion(path); !ok {
+		return fmt.Errorf("malformed module path %q: invalid version", path)
+	}
+	return nil
+}
+
+// CheckImportPath checks that an import path is valid.
+func CheckImportPath(path string) error {
+	if err := checkPath(path, false); err != nil {
+		return fmt.Errorf("malformed import path %q: %v", path, err)
+	}
+	return nil
+}
+
+// checkPath checks that a general path is valid.
+// It returns an error describing why but not mentioning path.
+// Because these checks apply to both module paths and import paths,
+// the caller is expected to add the "malformed ___ path %q: " prefix.
+// fileName indicates whether the final element of the path is a file name
+// (as opposed to a directory name).
+func checkPath(path string, fileName bool) error {
+	if !utf8.ValidString(path) {
+		return fmt.Errorf("invalid UTF-8")
+	}
+	if path == "" {
+		return fmt.Errorf("empty string")
+	}
+	if strings.Contains(path, "..") {
+		return fmt.Errorf("double dot")
+	}
+	if strings.Contains(path, "//") {
+		return fmt.Errorf("double slash")
+	}
+	if path[len(path)-1] == '/' {
+		return fmt.Errorf("trailing slash")
+	}
+	elemStart := 0
+	for i, r := range path {
+		if r == '/' {
+			if err := checkElem(path[elemStart:i], fileName); err != nil {
+				return err
+			}
+			elemStart = i + 1
+		}
+	}
+	if err := checkElem(path[elemStart:], fileName); err != nil {
+		return err
+	}
+	return nil
+}
+
+// checkElem checks whether an individual path element is valid.
+// fileName indicates whether the element is a file name (not a directory name).
+func checkElem(elem string, fileName bool) error {
+	if elem == "" {
+		return fmt.Errorf("empty path element")
+	}
+	if strings.Count(elem, ".") == len(elem) {
+		return fmt.Errorf("invalid path element %q", elem)
+	}
+	if elem[0] == '.' && !fileName {
+		return fmt.Errorf("leading dot in path element")
+	}
+	if elem[len(elem)-1] == '.' {
+		return fmt.Errorf("trailing dot in path element")
+	}
+	charOK := pathOK
+	if fileName {
+		charOK = fileNameOK
+	}
+	for _, r := range elem {
+		if !charOK(r) {
+			return fmt.Errorf("invalid char %q", r)
+		}
+	}
+
+	// Windows disallows a bunch of path elements, sadly.
+	// See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
+	short := elem
+	if i := strings.Index(short, "."); i >= 0 {
+		short = short[:i]
+	}
+	for _, bad := range badWindowsNames {
+		if strings.EqualFold(bad, short) {
+			return fmt.Errorf("disallowed path element %q", elem)
+		}
+	}
+	return nil
+}
+
+// CheckFilePath checks whether a slash-separated file path is valid.
+func CheckFilePath(path string) error {
+	if err := checkPath(path, true); err != nil {
+		return fmt.Errorf("malformed file path %q: %v", path, err)
+	}
+	return nil
+}
+
+// badWindowsNames are the reserved file path elements on Windows.
+// See https://docs.microsoft.com/en-us/windows/desktop/fileio/naming-a-file
+var badWindowsNames = []string{
+	"CON",
+	"PRN",
+	"AUX",
+	"NUL",
+	"COM1",
+	"COM2",
+	"COM3",
+	"COM4",
+	"COM5",
+	"COM6",
+	"COM7",
+	"COM8",
+	"COM9",
+	"LPT1",
+	"LPT2",
+	"LPT3",
+	"LPT4",
+	"LPT5",
+	"LPT6",
+	"LPT7",
+	"LPT8",
+	"LPT9",
+}
+
+// SplitPathVersion returns prefix and major version such that prefix+pathMajor == path
+// and version is either empty or "/vN" for N >= 2.
+// As a special case, gopkg.in paths are recognized directly;
+// they require ".vN" instead of "/vN", and for all N, not just N >= 2.
+func SplitPathVersion(path string) (prefix, pathMajor string, ok bool) {
+	if strings.HasPrefix(path, "gopkg.in/") {
+		return splitGopkgIn(path)
+	}
+
+	i := len(path)
+	dot := false
+	for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9' || path[i-1] == '.') {
+		if path[i-1] == '.' {
+			dot = true
+		}
+		i--
+	}
+	if i <= 1 || i == len(path) || path[i-1] != 'v' || path[i-2] != '/' {
+		return path, "", true
+	}
+	prefix, pathMajor = path[:i-2], path[i-2:]
+	if dot || len(pathMajor) <= 2 || pathMajor[2] == '0' || pathMajor == "/v1" {
+		return path, "", false
+	}
+	return prefix, pathMajor, true
+}
+
+// splitGopkgIn is like SplitPathVersion but only for gopkg.in paths.
+func splitGopkgIn(path string) (prefix, pathMajor string, ok bool) {
+	if !strings.HasPrefix(path, "gopkg.in/") {
+		return path, "", false
+	}
+	i := len(path)
+	if strings.HasSuffix(path, "-unstable") {
+		i -= len("-unstable")
+	}
+	for i > 0 && ('0' <= path[i-1] && path[i-1] <= '9') {
+		i--
+	}
+	if i <= 1 || path[i-1] != 'v' || path[i-2] != '.' {
+		// All gopkg.in paths must end in vN for some N.
+		return path, "", false
+	}
+	prefix, pathMajor = path[:i-2], path[i-2:]
+	if len(pathMajor) <= 2 || pathMajor[2] == '0' && pathMajor != ".v0" {
+		return path, "", false
+	}
+	return prefix, pathMajor, true
+}
+
+// MatchPathMajor reports whether the semantic version v
+// matches the path major version pathMajor.
+func MatchPathMajor(v, pathMajor string) bool {
+	if strings.HasPrefix(pathMajor, ".v") && strings.HasSuffix(pathMajor, "-unstable") {
+		pathMajor = strings.TrimSuffix(pathMajor, "-unstable")
+	}
+	if strings.HasPrefix(v, "v0.0.0-") && pathMajor == ".v1" {
+		// Allow old bug in pseudo-versions that generated v0.0.0- pseudoversion for gopkg .v1.
+		// For example, gopkg.in/yaml.v2@v2.2.1's go.mod requires gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405.
+		return true
+	}
+	m := semver.Major(v)
+	if pathMajor == "" {
+		return m == "v0" || m == "v1" || semver.Build(v) == "+incompatible"
+	}
+	return (pathMajor[0] == '/' || pathMajor[0] == '.') && m == pathMajor[1:]
+}
+
+// CanonicalVersion returns the canonical form of the version string v.
+// It is the same as semver.Canonical(v) except that it preserves the special build suffix "+incompatible".
+func CanonicalVersion(v string) string {
+	cv := semver.Canonical(v)
+	if semver.Build(v) == "+incompatible" {
+		cv += "+incompatible"
+	}
+	return cv
+}
+
+// Sort sorts the list by Path, breaking ties by comparing Versions.
+func Sort(list []Version) {
+	sort.Slice(list, func(i, j int) bool {
+		mi := list[i]
+		mj := list[j]
+		if mi.Path != mj.Path {
+			return mi.Path < mj.Path
+		}
+		// To help go.sum formatting, allow version/file.
+		// Compare semver prefix by semver rules,
+		// file by string order.
+		vi := mi.Version
+		vj := mj.Version
+		var fi, fj string
+		if k := strings.Index(vi, "/"); k >= 0 {
+			vi, fi = vi[:k], vi[k:]
+		}
+		if k := strings.Index(vj, "/"); k >= 0 {
+			vj, fj = vj[:k], vj[k:]
+		}
+		if vi != vj {
+			return semver.Compare(vi, vj) < 0
+		}
+		return fi < fj
+	})
+}
+
+// Safe encodings
+//
+// Module paths appear as substrings of file system paths
+// (in the download cache) and of web server URLs in the proxy protocol.
+// In general we cannot rely on file systems to be case-sensitive,
+// nor can we rely on web servers, since they read from file systems.
+// That is, we cannot rely on the file system to keep rsc.io/QUOTE
+// and rsc.io/quote separate. Windows and macOS don't.
+// Instead, we must never require two different casings of a file path.
+// Because we want the download cache to match the proxy protocol,
+// and because we want the proxy protocol to be possible to serve
+// from a tree of static files (which might be stored on a case-insensitive
+// file system), the proxy protocol must never require two different casings
+// of a URL path either.
+//
+// One possibility would be to make the safe encoding be the lowercase
+// hexadecimal encoding of the actual path bytes. This would avoid ever
+// needing different casings of a file path, but it would be fairly illegible
+// to most programmers when those paths appeared in the file system
+// (including in file paths in compiler errors and stack traces)
+// in web server logs, and so on. Instead, we want a safe encoding that
+// leaves most paths unaltered.
+//
+// The safe encoding is this:
+// replace every uppercase letter with an exclamation mark
+// followed by the letter's lowercase equivalent.
+//
+// For example,
+// github.com/Azure/azure-sdk-for-go ->  github.com/!azure/azure-sdk-for-go.
+// github.com/GoogleCloudPlatform/cloudsql-proxy -> github.com/!google!cloud!platform/cloudsql-proxy
+// github.com/Sirupsen/logrus -> github.com/!sirupsen/logrus.
+//
+// Import paths that avoid upper-case letters are left unchanged.
+// Note that because import paths are ASCII-only and avoid various
+// problematic punctuation (like : < and >), the safe encoding is also ASCII-only
+// and avoids the same problematic punctuation.
+//
+// Import paths have never allowed exclamation marks, so there is no
+// need to define how to encode a literal !.
+//
+// Although paths are disallowed from using Unicode (see pathOK above),
+// the eventual plan is to allow Unicode letters as well, to assume that
+// file systems and URLs are Unicode-safe (storing UTF-8), and apply
+// the !-for-uppercase convention. Note however that not all runes that
+// are different but case-fold equivalent are an upper/lower pair.
+// For example, U+004B ('K'), U+006B ('k'), and U+212A ('K' for Kelvin)
+// are considered to case-fold to each other. When we do add Unicode
+// letters, we must not assume that upper/lower are the only case-equivalent pairs.
+// Perhaps the Kelvin symbol would be disallowed entirely, for example.
+// Or perhaps it would encode as "!!k", or perhaps as "(212A)".
+//
+// Also, it would be nice to allow Unicode marks as well as letters,
+// but marks include combining marks, and then we must deal not
+// only with case folding but also normalization: both U+00E9 ('é')
+// and U+0065 U+0301 ('e' followed by combining acute accent)
+// look the same on the page and are treated by some file systems
+// as the same path. If we do allow Unicode marks in paths, there
+// must be some kind of normalization to allow only one canonical
+// encoding of any character used in an import path.
+
+// EncodePath returns the safe encoding of the given module path.
+// It fails if the module path is invalid.
+func EncodePath(path string) (encoding string, err error) {
+	if err := CheckPath(path); err != nil {
+		return "", err
+	}
+
+	return encodeString(path)
+}
+
+// EncodeVersion returns the safe encoding of the given module version.
+// Versions are allowed to be in non-semver form but must be valid file names
+// and not contain exclamation marks.
+func EncodeVersion(v string) (encoding string, err error) {
+	if err := checkElem(v, true); err != nil || strings.Contains(v, "!") {
+		return "", fmt.Errorf("disallowed version string %q", v)
+	}
+	return encodeString(v)
+}
+
+func encodeString(s string) (encoding string, err error) {
+	haveUpper := false
+	for _, r := range s {
+		if r == '!' || r >= utf8.RuneSelf {
+			// This should be disallowed by CheckPath, but diagnose anyway.
+			// The correctness of the encoding loop below depends on it.
+			return "", fmt.Errorf("internal error: inconsistency in EncodePath")
+		}
+		if 'A' <= r && r <= 'Z' {
+			haveUpper = true
+		}
+	}
+
+	if !haveUpper {
+		return s, nil
+	}
+
+	var buf []byte
+	for _, r := range s {
+		if 'A' <= r && r <= 'Z' {
+			buf = append(buf, '!', byte(r+'a'-'A'))
+		} else {
+			buf = append(buf, byte(r))
+		}
+	}
+	return string(buf), nil
+}
+
+// DecodePath returns the module path of the given safe encoding.
+// It fails if the encoding is invalid or encodes an invalid path.
+func DecodePath(encoding string) (path string, err error) {
+	path, ok := decodeString(encoding)
+	if !ok {
+		return "", fmt.Errorf("invalid module path encoding %q", encoding)
+	}
+	if err := CheckPath(path); err != nil {
+		return "", fmt.Errorf("invalid module path encoding %q: %v", encoding, err)
+	}
+	return path, nil
+}
+
+// DecodeVersion returns the version string for the given safe encoding.
+// It fails if the encoding is invalid or encodes an invalid version.
+// Versions are allowed to be in non-semver form but must be valid file names
+// and not contain exclamation marks.
+func DecodeVersion(encoding string) (v string, err error) {
+	v, ok := decodeString(encoding)
+	if !ok {
+		return "", fmt.Errorf("invalid version encoding %q", encoding)
+	}
+	if err := checkElem(v, true); err != nil {
+		return "", fmt.Errorf("disallowed version string %q", v)
+	}
+	return v, nil
+}
+
+func decodeString(encoding string) (string, bool) {
+	var buf []byte
+
+	bang := false
+	for _, r := range encoding {
+		if r >= utf8.RuneSelf {
+			return "", false
+		}
+		if bang {
+			bang = false
+			if r < 'a' || 'z' < r {
+				return "", false
+			}
+			buf = append(buf, byte(r+'A'-'a'))
+			continue
+		}
+		if r == '!' {
+			bang = true
+			continue
+		}
+		if 'A' <= r && r <= 'Z' {
+			return "", false
+		}
+		buf = append(buf, byte(r))
+	}
+	if bang {
+		return "", false
+	}
+	return string(buf), true
+}