Vendor changes

vendor.conf

@@ -2,5 +2,5 @@
 github.com/rancher/types
 
 github.com/pkg/errors v0.8.0
-github.com/rancher/norman 457c15b94acae52afb5290aa315452c7621d452a transitive=true
+github.com/rancher/norman 03b89d4fb7143786491cee420102775a803fbed1
 github.com/coreos/prometheus-operator         v0.25.0 

vendor/github.com/matryer/moq/.gitignore

@@ -0,0 +1,25 @@
+# Compiled Object files, Static and Dynamic libs (Shared Objects)
+*.o
+*.a
+*.so
+
+# Folders
+_obj
+_test
+
+# Architecture specific extensions/prefixes
+*.[568vq]
+[568vq].out
+
+*.cgo1.go
+*.cgo2.c
+_cgo_defun.c
+_cgo_gotypes.go
+_cgo_export.*
+
+_testmain.go
+
+*.exe
+*.test
+*.prof
+.vscode

vendor/github.com/matryer/moq/.travis.yml

@@ -0,0 +1,19 @@
+language: go
+
+sudo: false
+
+go:
+  - 1.9.x
+  - 1.10.x
+  - 1.11.x
+  - tip
+
+before_install:
+  - go get golang.org/x/lint/golint
+
+before_script:
+  - go vet ./...
+  - golint ./...
+
+script:
+  - go test -v ./...

vendor/github.com/matryer/moq/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2016 Mat Ryer and David Hernandez
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

vendor/github.com/matryer/moq/README.md

@@ -0,0 +1,108 @@
+![moq logo](moq-logo-small.png) [![Build Status](https://travis-ci.org/matryer/moq.svg?branch=master)](https://travis-ci.org/matryer/moq) [![Go Report Card](https://goreportcard.com/badge/github.com/matryer/moq)](https://goreportcard.com/report/github.com/matryer/moq)
+
+Interface mocking tool for go generate.
+
+By [Mat Ryer](https://twitter.com/matryer) and [David Hernandez](https://github.com/dahernan), with ideas lovingly stolen from [Ernesto Jimenez](https://github.com/ernesto-jimenez).
+
+### What is Moq?
+
+Moq is a tool that generates a struct from any interface. The struct can be used in test code as a mock of the interface.
+
+![Preview](preview.png)
+
+above: Moq generates the code on the right.
+
+You can read more in the [Meet Moq blog post](http://bit.ly/meetmoq).
+
+### Installing
+
+To start using Moq, just run go get:
+```
+$ go get github.com/matryer/moq
+```
+
+### Usage
+
+```
+moq [flags] destination interface [interface2 [interface3 [...]]]
+  -out string
+    	output file (default stdout)
+  -pkg string
+    	package name (default will infer)
+```
+
+In a command line:
+
+```
+$ moq -out mocks_test.go . MyInterface
+```
+
+In code (for go generate):
+
+```go
+package my
+
+//go:generate moq -out myinterface_moq_test.go . MyInterface
+
+type MyInterface interface {
+	Method1() error
+	Method2(i int)
+}
+```
+
+Then run `go generate` for your package.
+
+### How to use it
+
+Mocking interfaces is a nice way to write unit tests where you can easily control the behaviour of the mocked object.
+
+Moq creates a struct that has a function field for each method, which you can declare in your test code.
+
+This this example, Moq generated the `EmailSenderMock` type:
+
+```go
+func TestCompleteSignup(t *testing.T) {
+
+	var sentTo string 
+
+	mockedEmailSender = &EmailSenderMock{
+		SendFunc: func(to, subject, body string) error {
+			sentTo = to
+			return nil
+		},
+	}
+
+	CompleteSignUp("me@email.com", mockedEmailSender)
+
+	callsToSend := len(mockedEmailSender.SendCalls())
+	if callsToSend != 1 {
+		t.Errorf("Send was called %d times", callsToSend)
+	}
+	if sentTo != "me@email.com" {
+		t.Errorf("unexpected recipient: %s", sentTo)
+	}
+
+}
+
+func CompleteSignUp(to string, sender EmailSender) {
+	// TODO: this
+}
+```
+
+The mocked structure implements the interface, where each method calls the associated function field.
+
+## Tips
+
+* Keep mocked logic inside the test that is using it
+* Only mock the fields you need
+* It will panic if a nil function gets called
+* Name arguments in the interface for a better experience
+* Use closured variables inside your test function to capture details about the calls to the methods
+* Use `.MethodCalls()` to track the calls
+* Use `go:generate` to invoke the `moq` command
+
+## License
+
+The Moq project (and all code) is licensed under the [MIT License](LICENSE).
+
+The Moq logo was created by [Chris Ryer](http://chrisryer.co.uk) and is licensed under the [Creative Commons Attribution 3.0 License](https://creativecommons.org/licenses/by/3.0/).

vendor/github.com/matryer/moq/pkg/moq/moq.go

@@ -0,0 +1,379 @@
+package moq
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+	"go/format"
+	"go/types"
+	"io"
+	"os"
+	"path"
+	"path/filepath"
+	"strings"
+	"text/template"
+
+	"golang.org/x/tools/go/packages"
+)
+
+// This list comes from the golint codebase. Golint will complain about any of
+// these being mixed-case, like "Id" instead of "ID".
+var golintInitialisms = []string{
+	"ACL",
+	"API",
+	"ASCII",
+	"CPU",
+	"CSS",
+	"DNS",
+	"EOF",
+	"GUID",
+	"HTML",
+	"HTTP",
+	"HTTPS",
+	"ID",
+	"IP",
+	"JSON",
+	"LHS",
+	"QPS",
+	"RAM",
+	"RHS",
+	"RPC",
+	"SLA",
+	"SMTP",
+	"SQL",
+	"SSH",
+	"TCP",
+	"TLS",
+	"TTL",
+	"UDP",
+	"UI",
+	"UID",
+	"UUID",
+	"URI",
+	"URL",
+	"UTF8",
+	"VM",
+	"XML",
+	"XMPP",
+	"XSRF",
+	"XSS",
+}
+
+// Mocker can generate mock structs.
+type Mocker struct {
+	srcPkg  *packages.Package
+	tmpl    *template.Template
+	pkgName string
+	pkgPath string
+	// importByPath of the format key:path value:alias
+	importByPath map[string]string
+	// importByAlias of the format key:alias value:path
+	importByAlias map[string]string
+}
+
+// New makes a new Mocker for the specified package directory.
+func New(src, packageName string) (*Mocker, error) {
+	srcPkg, err := pkgInfoFromPath(src, packages.LoadSyntax)
+	if err != nil {
+		return nil, fmt.Errorf("Couldn't load source package: %s", err)
+	}
+	pkgPath := srcPkg.PkgPath
+
+	if len(packageName) == 0 {
+		packageName = srcPkg.Name
+	} else {
+		mockPkgPath := filepath.Join(src, packageName)
+		if _, err := os.Stat(mockPkgPath); os.IsNotExist(err) {
+			os.Mkdir(mockPkgPath, os.ModePerm)
+		}
+		mockPkg, err := pkgInfoFromPath(mockPkgPath, packages.LoadFiles)
+		if err != nil {
+			return nil, fmt.Errorf("Couldn't load mock package: %s", err)
+		}
+		pkgPath = mockPkg.PkgPath
+	}
+
+	tmpl, err := template.New("moq").Funcs(templateFuncs).Parse(moqTemplate)
+	if err != nil {
+		return nil, err
+	}
+	return &Mocker{
+		tmpl:          tmpl,
+		srcPkg:        srcPkg,
+		pkgName:       packageName,
+		pkgPath:       pkgPath,
+		importByPath:  make(map[string]string),
+		importByAlias: make(map[string]string),
+	}, nil
+}
+
+// Mock generates a mock for the specified interface name.
+func (m *Mocker) Mock(w io.Writer, name ...string) error {
+	if len(name) == 0 {
+		return errors.New("must specify one interface")
+	}
+
+	doc := doc{
+		PackageName: m.pkgName,
+		Imports:     moqImports,
+	}
+
+	// Add sync first to ensure it doesn't get an alias which will break the template
+	m.addSyncImport()
+
+	var syncNeeded bool
+
+	tpkg := m.srcPkg.Types
+	for _, n := range name {
+		iface := tpkg.Scope().Lookup(n)
+		if iface == nil {
+			return fmt.Errorf("cannot find interface %s", n)
+		}
+		if !types.IsInterface(iface.Type()) {
+			return fmt.Errorf("%s (%s) not an interface", n, iface.Type().String())
+		}
+		iiface := iface.Type().Underlying().(*types.Interface).Complete()
+		obj := obj{
+			InterfaceName: n,
+		}
+		for i := 0; i < iiface.NumMethods(); i++ {
+			syncNeeded = true
+			meth := iiface.Method(i)
+			sig := meth.Type().(*types.Signature)
+			method := &method{
+				Name: meth.Name(),
+			}
+			obj.Methods = append(obj.Methods, method)
+			method.Params = m.extractArgs(sig, sig.Params(), "in%d")
+			method.Returns = m.extractArgs(sig, sig.Results(), "out%d")
+		}
+		doc.Objects = append(doc.Objects, obj)
+	}
+
+	if !syncNeeded {
+		delete(m.importByAlias, "sync")
+		delete(m.importByPath, "sync")
+	}
+
+	if tpkg.Name() != m.pkgName {
+		if _, ok := m.importByPath[tpkg.Path()]; !ok {
+			alias := m.getUniqueAlias(tpkg.Name())
+			m.importByAlias[alias] = tpkg.Path()
+			m.importByPath[tpkg.Path()] = alias
+		}
+		doc.SourcePackagePrefix = m.importByPath[tpkg.Path()] + "."
+	}
+
+	for alias, path := range m.importByAlias {
+		aliasImport := fmt.Sprintf(`%s "%s"`, alias, stripVendorPath(path))
+		doc.Imports = append(doc.Imports, aliasImport)
+	}
+
+	var buf bytes.Buffer
+	err := m.tmpl.Execute(&buf, doc)
+	if err != nil {
+		return err
+	}
+	formatted, err := format.Source(buf.Bytes())
+	if err != nil {
+		return fmt.Errorf("go/format: %s", err)
+	}
+	if _, err := w.Write(formatted); err != nil {
+		return err
+	}
+	return nil
+}
+
+func (m *Mocker) addSyncImport() {
+	if _, ok := m.importByPath["sync"]; !ok {
+		m.importByAlias["sync"] = "sync"
+		m.importByPath["sync"] = "sync"
+	}
+}
+
+func (m *Mocker) packageQualifier(pkg *types.Package) string {
+	if m.pkgPath == pkg.Path() {
+		return ""
+	}
+	path := pkg.Path()
+	if pkg.Path() == "." {
+		wd, err := os.Getwd()
+		if err == nil {
+			path = stripGopath(wd)
+		}
+	}
+
+	if alias, ok := m.importByPath[path]; ok {
+		return alias
+	}
+
+	alias := pkg.Name()
+
+	if _, ok := m.importByAlias[alias]; ok {
+		alias = m.getUniqueAlias(alias)
+	}
+
+	m.importByAlias[alias] = path
+	m.importByPath[path] = alias
+
+	return alias
+}
+
+func (m *Mocker) getUniqueAlias(alias string) string {
+	for i := 0; ; i++ {
+		newAlias := alias + string('a'+byte(i))
+		if _, exists := m.importByAlias[newAlias]; !exists {
+			return newAlias
+		}
+	}
+}
+
+func (m *Mocker) extractArgs(sig *types.Signature, list *types.Tuple, nameFormat string) []*param {
+	var params []*param
+	listLen := list.Len()
+	for ii := 0; ii < listLen; ii++ {
+		p := list.At(ii)
+		name := p.Name()
+		if name == "" {
+			name = fmt.Sprintf(nameFormat, ii+1)
+		}
+		typename := types.TypeString(p.Type(), m.packageQualifier)
+		// check for final variadic argument
+		variadic := sig.Variadic() && ii == listLen-1 && typename[0:2] == "[]"
+		param := &param{
+			Name:     name,
+			Type:     typename,
+			Variadic: variadic,
+		}
+		params = append(params, param)
+	}
+	return params
+}
+
+func pkgInfoFromPath(src string, mode packages.LoadMode) (*packages.Package, error) {
+	conf := packages.Config{
+		Mode: mode,
+		Dir:  src,
+	}
+	pkgs, err := packages.Load(&conf)
+	if err != nil {
+		return nil, err
+	}
+	if len(pkgs) == 0 {
+		return nil, errors.New("No packages found")
+	}
+	if len(pkgs) > 1 {
+		return nil, errors.New("More than one package was found")
+	}
+	return pkgs[0], nil
+}
+
+type doc struct {
+	PackageName         string
+	SourcePackagePrefix string
+	Objects             []obj
+	Imports             []string
+}
+
+type obj struct {
+	InterfaceName string
+	Methods       []*method
+}
+type method struct {
+	Name    string
+	Params  []*param
+	Returns []*param
+}
+
+func (m *method) Arglist() string {
+	params := make([]string, len(m.Params))
+	for i, p := range m.Params {
+		params[i] = p.String()
+	}
+	return strings.Join(params, ", ")
+}
+
+func (m *method) ArgCallList() string {
+	params := make([]string, len(m.Params))
+	for i, p := range m.Params {
+		params[i] = p.CallName()
+	}
+	return strings.Join(params, ", ")
+}
+
+func (m *method) ReturnArglist() string {
+	params := make([]string, len(m.Returns))
+	for i, p := range m.Returns {
+		params[i] = p.TypeString()
+	}
+	if len(m.Returns) > 1 {
+		return fmt.Sprintf("(%s)", strings.Join(params, ", "))
+	}
+	return strings.Join(params, ", ")
+}
+
+type param struct {
+	Name     string
+	Type     string
+	Variadic bool
+}
+
+func (p param) String() string {
+	return fmt.Sprintf("%s %s", p.Name, p.TypeString())
+}
+
+func (p param) CallName() string {
+	if p.Variadic {
+		return p.Name + "..."
+	}
+	return p.Name
+}
+
+func (p param) TypeString() string {
+	if p.Variadic {
+		return "..." + p.Type[2:]
+	}
+	return p.Type
+}
+
+var templateFuncs = template.FuncMap{
+	"Exported": func(s string) string {
+		if s == "" {
+			return ""
+		}
+		for _, initialism := range golintInitialisms {
+			if strings.ToUpper(s) == initialism {
+				return initialism
+			}
+		}
+		return strings.ToUpper(s[0:1]) + s[1:]
+	},
+}
+
+// stripVendorPath strips the vendor dir prefix from a package path.
+// For example we might encounter an absolute path like
+// github.com/foo/bar/vendor/github.com/pkg/errors which is resolved
+// to github.com/pkg/errors.
+func stripVendorPath(p string) string {
+	parts := strings.Split(p, "/vendor/")
+	if len(parts) == 1 {
+		return p
+	}
+	return strings.TrimLeft(path.Join(parts[1:]...), "/")
+}
+
+// stripGopath takes the directory to a package and remove the gopath to get the
+// canonical package name.
+//
+// taken from https://github.com/ernesto-jimenez/gogen
+// Copyright (c) 2015 Ernesto Jiménez
+func stripGopath(p string) string {
+	for _, gopath := range gopaths() {
+		p = strings.TrimPrefix(p, path.Join(gopath, "src")+"/")
+	}
+	return p
+}
+
+func gopaths() []string {
+	return strings.Split(os.Getenv("GOPATH"), string(filepath.ListSeparator))
+}

vendor/github.com/matryer/moq/pkg/moq/template.go

@@ -0,0 +1,107 @@
+package moq
+
+// moqImports are the imports all moq files get.
+var moqImports = []string{}
+
+// moqTemplate is the template for mocked code.
+var moqTemplate = `// Code generated by moq; DO NOT EDIT.
+// github.com/matryer/moq
+
+package {{.PackageName}}
+{{- $sourcePackagePrefix := .SourcePackagePrefix}}
+
+import (
+{{- range .Imports }}
+	{{.}}
+{{- end }}
+)
+
+{{ range $i, $obj := .Objects -}}
+var (
+{{- range .Methods }}
+	lock{{$obj.InterfaceName}}Mock{{.Name}}	sync.RWMutex
+{{- end }}
+)
+
+// Ensure, that {{.InterfaceName}}Mock does implement {{.InterfaceName}}.
+// If this is not the case, regenerate this file with moq.
+var _ {{$sourcePackagePrefix}}{{.InterfaceName}} = &{{.InterfaceName}}Mock{}
+
+// {{.InterfaceName}}Mock is a mock implementation of {{.InterfaceName}}.
+//
+//     func TestSomethingThatUses{{.InterfaceName}}(t *testing.T) {
+//
+//         // make and configure a mocked {{.InterfaceName}}
+//         mocked{{.InterfaceName}} := &{{.InterfaceName}}Mock{ {{ range .Methods }}
+//             {{.Name}}Func: func({{ .Arglist }}) {{.ReturnArglist}} {
+// 	               panic("mock out the {{.Name}} method")
+//             },{{- end }}
+//         }
+//
+//         // use mocked{{.InterfaceName}} in code that requires {{.InterfaceName}}
+//         // and then make assertions.
+//
+//     }
+type {{.InterfaceName}}Mock struct {
+{{- range .Methods }}
+	// {{.Name}}Func mocks the {{.Name}} method.
+	{{.Name}}Func func({{ .Arglist }}) {{.ReturnArglist}}
+{{ end }}
+	// calls tracks calls to the methods.
+	calls struct {
+{{- range .Methods }}
+		// {{ .Name }} holds details about calls to the {{.Name}} method.
+		{{ .Name }} []struct {
+			{{- range .Params }}
+			// {{ .Name | Exported }} is the {{ .Name }} argument value.
+			{{ .Name | Exported }} {{ .Type }}
+			{{- end }}
+		}
+{{- end }}
+	}
+}
+{{ range .Methods }}
+// {{.Name}} calls {{.Name}}Func.
+func (mock *{{$obj.InterfaceName}}Mock) {{.Name}}({{.Arglist}}) {{.ReturnArglist}} {
+	if mock.{{.Name}}Func == nil {
+		panic("{{$obj.InterfaceName}}Mock.{{.Name}}Func: method is nil but {{$obj.InterfaceName}}.{{.Name}} was just called")
+	}
+	callInfo := struct {
+		{{- range .Params }}
+		{{ .Name | Exported }} {{ .Type }}
+		{{- end }}
+	}{
+		{{- range .Params }}
+		{{ .Name | Exported }}: {{ .Name }},
+		{{- end }}
+	}
+	lock{{$obj.InterfaceName}}Mock{{.Name}}.Lock()
+	mock.calls.{{.Name}} = append(mock.calls.{{.Name}}, callInfo)
+	lock{{$obj.InterfaceName}}Mock{{.Name}}.Unlock()
+{{- if .ReturnArglist }}
+	return mock.{{.Name}}Func({{.ArgCallList}})
+{{- else }}
+	mock.{{.Name}}Func({{.ArgCallList}})
+{{- end }}
+}
+
+// {{.Name}}Calls gets all the calls that were made to {{.Name}}.
+// Check the length with:
+//     len(mocked{{$obj.InterfaceName}}.{{.Name}}Calls())
+func (mock *{{$obj.InterfaceName}}Mock) {{.Name}}Calls() []struct {
+		{{- range .Params }}
+		{{ .Name | Exported }} {{ .Type }}
+		{{- end }}
+	} {
+	var calls []struct {
+		{{- range .Params }}
+		{{ .Name | Exported }} {{ .Type }}
+		{{- end }}
+	}
+	lock{{$obj.InterfaceName}}Mock{{.Name}}.RLock()
+	calls = mock.calls.{{.Name}}
+	lock{{$obj.InterfaceName}}Mock{{.Name}}.RUnlock()
+	return calls
+}
+{{ end -}}
+{{ end -}}`

vendor/github.com/rancher/norman/.drone.yml

@@ -1,9 +1,23 @@
 ---
-pipeline:
-  build:
-    privileged: true
-    image: rancher/dapper:1.11.2
-    volumes:
-    - /var/run/docker.sock:/var/run/docker.sock
-    commands:
-    - dapper ci
+kind: pipeline
+name: default
+
+platform:
+  os: linux
+  arch: amd64
+
+steps:
+- name: build
+  pull: default
+  image: rancher/dapper:1.11.2
+  commands:
+  - dapper ci
+  privileged: true
+  volumes:
+  - name: socket
+    path: /var/run/docker.sock
+
+volumes:
+- name: socket
+  host:
+    path: /var/run/docker.sock

vendor/github.com/rancher/norman/clientbase/common.go

@@ -7,6 +7,7 @@ import (
 	"encoding/base64"
 	"encoding/json"
 	"fmt"
+	"io"
 	"io/ioutil"
 	"net/http"
 	"net/url"
@@ -216,7 +217,9 @@ func NewAPIClient(opts *ClientOpts) (APIBaseClient, error) {
 	if err != nil {
 		return result, err
 	}
-	defer resp.Body.Close()
+	defer func(closer io.Closer) {
+		closer.Close()
+	}(resp.Body)
 
 	if resp.StatusCode != 200 {
 		return result, NewAPIError(resp, opts.URL)
@@ -242,7 +245,9 @@ func NewAPIClient(opts *ClientOpts) (APIBaseClient, error) {
 		if err != nil {
 			return result, err
 		}
-		defer resp.Body.Close()
+		defer func(closer io.Closer) {
+			closer.Close()
+		}(resp.Body)
 
 		if resp.StatusCode != 200 {
 			return result, NewAPIError(resp, schemasURLs)

vendor/github.com/rancher/norman/clientbase/ops.go

@@ -120,6 +120,12 @@ func (a *APIOperations) DoNext(nextURL string, respObject interface{}) error {
 }
 
 func (a *APIOperations) DoModify(method string, url string, createObj interface{}, respObject interface{}) error {
+	if createObj == nil {
+		createObj = map[string]string{}
+	}
+	if respObject == nil {
+		respObject = &map[string]interface{}{}
+	}
 	bodyContent, err := json.Marshal(createObj)
 	if err != nil {
 		return err

vendor/github.com/rancher/norman/controller/generic_controller.go

@@ -304,7 +304,7 @@ func filterConflictsError(err error) error {
 		var newErrors []error
 		for _, err := range errs.Errors {
 			if !ignoreError(err, true) {
-				newErrors = append(newErrors)
+				newErrors = append(newErrors, err)
 			}
 		}
 		return types.NewErrors(newErrors...)

vendor/github.com/rancher/norman/generator/controller_template.go

@@ -46,7 +46,7 @@ func New{{.schema.CodeName}}(namespace, name string, obj {{.prefix}}{{.schema.Co
 type {{.schema.CodeName}}List struct {
 	metav1.TypeMeta   %BACK%json:",inline"%BACK%
 	metav1.ListMeta   %BACK%json:"metadata,omitempty"%BACK%
-	Items             []{{.prefix}}{{.schema.CodeName}}
+	Items             []{{.prefix}}{{.schema.CodeName}} %BACK%json:"items"%BACK%
 }
 
 type {{.schema.CodeName}}HandlerFunc func(key string, obj *{{.prefix}}{{.schema.CodeName}}) (runtime.Object, error)

vendor/github.com/rancher/norman/generator/generator.go

@@ -1,6 +1,7 @@
 package generator
 
 import (
+	"bytes"
 	"fmt"
 	"io/ioutil"
 	"net/http"
@@ -11,6 +12,7 @@ import (
 	"strings"
 	"text/template"
 
+	"github.com/matryer/moq/pkg/moq"
 	"github.com/pkg/errors"
 	"github.com/rancher/norman/types"
 	"github.com/rancher/norman/types/convert"
@@ -306,7 +308,9 @@ func GenerateControllerForTypes(version *types.APIVersion, k8sOutputPackage stri
 	baseDir := args.DefaultSourceTree()
 	k8sDir := path.Join(baseDir, k8sOutputPackage)
 
-	if err := prepareDirs(k8sDir); err != nil {
+	fakeDir := path.Join(k8sDir, "fakes")
+
+	if err := prepareDirs(k8sDir, fakeDir); err != nil {
 		return err
 	}
 
@@ -358,6 +362,10 @@ func GenerateControllerForTypes(version *types.APIVersion, k8sOutputPackage stri
 		return err
 	}
 
+	if err := generateFakes(k8sDir, controllers); err != nil {
+		return err
+	}
+
 	return gofmt(baseDir, k8sOutputPackage)
 }
 
@@ -370,7 +378,9 @@ func Generate(schemas *types.Schemas, privateTypes map[string]bool, cattleOutput
 		cattleDir = ""
 	}
 
-	if err := prepareDirs(cattleDir, k8sDir); err != nil {
+	fakeDir := path.Join(k8sDir, "fakes")
+
+	if err := prepareDirs(cattleDir, k8sDir, fakeDir); err != nil {
 		return err
 	}
 
@@ -426,6 +436,9 @@ func Generate(schemas *types.Schemas, privateTypes map[string]bool, cattleOutput
 		if err := generateScheme(false, k8sDir, &controllers[0].Version, controllers); err != nil {
 			return err
 		}
+		if err := generateFakes(k8sDir, controllers); err != nil {
+			return err
+		}
 	}
 
 	if err := gofmt(baseDir, k8sOutputPackage); err != nil {
@@ -455,7 +468,7 @@ func prepareDirs(dirs ...string) error {
 		}
 
 		for _, file := range files {
-			if strings.HasPrefix(file.Name(), "zz_generated") {
+			if strings.HasPrefix(file.Name(), "zz_generated") || strings.HasSuffix(file.Name(), "_mock_test.go") {
 				if err := os.Remove(path.Join(dir, file.Name())); err != nil {
 					return errors.Wrapf(err, "failed to delete %s", path.Join(dir, file.Name()))
 				}
@@ -531,3 +544,33 @@ func isObjectOrList(t *gengotypes.Type) bool {
 
 	return false
 }
+
+func generateFakes(k8sDir string, controllers []*types.Schema) error {
+	m, err := moq.New(k8sDir, "fakes")
+	if err != nil {
+		return err
+	}
+
+	for _, controller := range controllers {
+		var out bytes.Buffer
+
+		interfaceNames := []string{
+			controller.CodeName + "Lister",
+			controller.CodeName + "Controller",
+			controller.CodeName + "Interface",
+			controller.CodeNamePlural + "Getter",
+		}
+
+		err = m.Mock(&out, interfaceNames...)
+		if err != nil {
+			return err
+		}
+		// create the file
+		filePath := path.Join(k8sDir, "fakes", "zz_generated_"+addUnderscore(controller.ID)+"_mock_test.go")
+		err = ioutil.WriteFile(filePath, out.Bytes(), 0644)
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}

vendor/github.com/rancher/norman/generator/scheme_template.go

@@ -3,6 +3,7 @@ package generator
 var schemeTemplate = `package {{.version.Version}}
 
 import (
+	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
 	"k8s.io/apimachinery/pkg/runtime"
 	"k8s.io/apimachinery/pkg/runtime/schema"
 )
@@ -37,6 +38,7 @@ func addKnownTypes(scheme *runtime.Scheme) error {
 	{{range .names}}
 	&{{.}}{},{{end}}
 	)
+	metav1.AddToGroupVersion(scheme, SchemeGroupVersion)
 	return nil
 }
 `

vendor/github.com/rancher/norman/objectclient/object_client.go

@@ -102,6 +102,13 @@ func (p *ObjectClient) Create(o runtime.Object) (runtime.Object, error) {
 		labels := obj.GetLabels()
 		if labels == nil {
 			labels = make(map[string]string)
+		} else {
+			ls := make(map[string]string)
+			for k, v := range labels {
+				ls[k] = v
+			}
+			labels = ls
+
 		}
 		labels["cattle.io/creator"] = "norman"
 		obj.SetLabels(labels)

vendor/github.com/rancher/norman/restwatch/rest.go

@@ -21,7 +21,7 @@ func UnversionedRESTClientFor(config *rest.Config) (rest.Interface, error) {
 	}
 
 	newConfig := *config
-	newConfig.Timeout = time.Hour
+	newConfig.Timeout = 30 * time.Minute
 	watchClient, err := rest.UnversionedRESTClientFor(&newConfig)
 	if err != nil {
 		return nil, err

vendor/github.com/rancher/norman/store/proxy/proxy_store.go

@@ -17,6 +17,7 @@ import (
 	"github.com/rancher/norman/types/convert/merge"
 	"github.com/rancher/norman/types/values"
 	"github.com/sirupsen/logrus"
+	"golang.org/x/sync/errgroup"
 	"k8s.io/apiextensions-apiserver/pkg/client/clientset/clientset"
 	"k8s.io/apimachinery/pkg/api/errors"
 	metav1 "k8s.io/apimachinery/pkg/apis/meta/v1"
@@ -192,11 +193,41 @@ func (s *Store) Context() types.StorageContext {
 }
 
 func (s *Store) List(apiContext *types.APIContext, schema *types.Schema, opt *types.QueryOptions) ([]map[string]interface{}, error) {
-	namespace := getNamespace(apiContext, opt)
+	var resultList unstructured.UnstructuredList
 
-	resultList, err := s.retryList(namespace, apiContext)
-	if err != nil {
-		return nil, err
+	// if there are no namespaces field in options, a single request is made
+	if opt == nil || opt.Namespaces == nil {
+		ns := getNamespace(apiContext, opt)
+		list, err := s.retryList(ns, apiContext)
+		if err != nil {
+			return nil, err
+		}
+		resultList = *list
+	} else {
+		var (
+			errGroup errgroup.Group
+			mux      sync.Mutex
+		)
+
+		allNS := opt.Namespaces
+		for _, ns := range allNS {
+			nsCopy := ns
+			errGroup.Go(func() error {
+				list, err := s.retryList(nsCopy, apiContext)
+				if err != nil {
+					return err
+				}
+
+				mux.Lock()
+				resultList.Items = append(resultList.Items, list.Items...)
+				mux.Unlock()
+
+				return nil
+			})
+		}
+		if err := errGroup.Wait(); err != nil {
+			return nil, err
+		}
 	}
 
 	var result []map[string]interface{}
@@ -256,7 +287,7 @@ func (s *Store) realWatch(apiContext *types.APIContext, schema *types.Schema, op
 		k8sClient = watchClient.WatchClient()
 	}
 
-	timeout := int64(60 * 60)
+	timeout := int64(60 * 30)
 	req := s.common(namespace, k8sClient.Get())
 	req.VersionedParams(&metav1.ListOptions{
 		Watch:           true,

vendor/github.com/rancher/norman/types/mapper/embed.go

@@ -70,10 +70,11 @@ func (e *Embed) ModifySchema(schema *types.Schema, schemas *types.Schemas) error
 	}
 
 	deleteField := true
+outer:
 	for name, field := range embeddedSchema.ResourceFields {
 		for _, ignore := range e.Ignore {
 			if ignore == name {
-				continue
+				continue outer
 			}
 		}
 

vendor/github.com/rancher/norman/types/schemas.go

@@ -108,10 +108,16 @@ func (s *Schemas) removeReferences(schema *Schema) {
 func (s *Schemas) AddSchema(schema Schema) *Schemas {
 	s.Lock()
 	defer s.Unlock()
-	return s.doAddSchema(schema)
+	return s.doAddSchema(schema, false)
 }
 
-func (s *Schemas) doAddSchema(schema Schema) *Schemas {
+func (s *Schemas) ForceAddSchema(schema Schema) *Schemas {
+	s.Lock()
+	defer s.Unlock()
+	return s.doAddSchema(schema, true)
+}
+
+func (s *Schemas) doAddSchema(schema Schema, replace bool) *Schemas {
 	s.setupDefaults(&schema)
 
 	if s.AddHook != nil {
@@ -125,9 +131,20 @@ func (s *Schemas) doAddSchema(schema Schema) *Schemas {
 		s.versions = append(s.versions, schema.Version)
 	}
 
-	if _, ok := schemas[schema.ID]; !ok {
+	if _, ok := schemas[schema.ID]; !ok ||
+		(replace && schema.DynamicSchemaVersion != schemas[schema.ID].DynamicSchemaVersion) {
 		schemas[schema.ID] = &schema
-		s.schemas = append(s.schemas, &schema)
+
+		if replace {
+			for i, candidate := range s.schemas {
+				if candidate.ID == schema.ID {
+					s.schemas[i] = &schema
+					break
+				}
+			}
+		} else {
+			s.schemas = append(s.schemas, &schema)
+		}
 
 		if !schema.Embed {
 			s.addReferences(&schema)
@@ -159,7 +176,7 @@ func (s *Schemas) removeEmbed(schema *Schema) {
 	}
 
 	s.doRemoveSchema(*target)
-	s.doAddSchema(newSchema)
+	s.doAddSchema(newSchema, false)
 }
 
 func (s *Schemas) embed(schema *Schema) {
@@ -184,7 +201,7 @@ func (s *Schemas) embed(schema *Schema) {
 	}
 
 	s.doRemoveSchema(*target)
-	s.doAddSchema(newSchema)
+	s.doAddSchema(newSchema, false)
 }
 
 func (s *Schemas) addReferences(schema *Schema) {

vendor/github.com/rancher/norman/types/server_types.go

@@ -184,6 +184,8 @@ type QueryOptions struct {
 	Pagination *Pagination
 	Conditions []*QueryCondition
 	Options    map[string]string
+	// Set namespaces to an empty array will result in an empty response
+	Namespaces []string
 }
 
 type ReferenceValidator interface {

vendor/github.com/rancher/norman/types/types.go

@@ -94,25 +94,26 @@ var NamespaceScope TypeScope = "namespace"
 type TypeScope string
 
 type Schema struct {
-	ID                string            `json:"id,omitempty"`
-	Embed             bool              `json:"embed,omitempty"`
-	EmbedType         string            `json:"embedType,omitempty"`
-	CodeName          string            `json:"-"`
-	CodeNamePlural    string            `json:"-"`
-	PkgName           string            `json:"-"`
-	Type              string            `json:"type,omitempty"`
-	BaseType          string            `json:"baseType,omitempty"`
-	Links             map[string]string `json:"links"`
-	Version           APIVersion        `json:"version"`
-	PluralName        string            `json:"pluralName,omitempty"`
-	ResourceMethods   []string          `json:"resourceMethods,omitempty"`
-	ResourceFields    map[string]Field  `json:"resourceFields"`
-	ResourceActions   map[string]Action `json:"resourceActions,omitempty"`
-	CollectionMethods []string          `json:"collectionMethods,omitempty"`
-	CollectionFields  map[string]Field  `json:"collectionFields,omitempty"`
-	CollectionActions map[string]Action `json:"collectionActions,omitempty"`
-	CollectionFilters map[string]Filter `json:"collectionFilters,omitempty"`
-	Scope             TypeScope         `json:"-"`
+	ID                   string            `json:"id,omitempty"`
+	Embed                bool              `json:"embed,omitempty"`
+	EmbedType            string            `json:"embedType,omitempty"`
+	CodeName             string            `json:"-"`
+	CodeNamePlural       string            `json:"-"`
+	PkgName              string            `json:"-"`
+	Type                 string            `json:"type,omitempty"`
+	BaseType             string            `json:"baseType,omitempty"`
+	Links                map[string]string `json:"links"`
+	Version              APIVersion        `json:"version"`
+	PluralName           string            `json:"pluralName,omitempty"`
+	ResourceMethods      []string          `json:"resourceMethods,omitempty"`
+	ResourceFields       map[string]Field  `json:"resourceFields"`
+	ResourceActions      map[string]Action `json:"resourceActions,omitempty"`
+	CollectionMethods    []string          `json:"collectionMethods,omitempty"`
+	CollectionFields     map[string]Field  `json:"collectionFields,omitempty"`
+	CollectionActions    map[string]Action `json:"collectionActions,omitempty"`
+	CollectionFilters    map[string]Filter `json:"collectionFilters,omitempty"`
+	DynamicSchemaVersion string            `json:"dynamicSchemaVersion,omitempty"`
+	Scope                TypeScope         `json:"-"`
 
 	InternalSchema      *Schema             `json:"-"`
 	Mapper              Mapper              `json:"-"`

vendor/github.com/rancher/norman/vendor.conf

@@ -5,4 +5,6 @@ k8s.io/kubernetes                v1.12.2-lite1                             https
 github.com/maruel/panicparse     c0182c169410cfa80c7e8f046dad208eaef91338
 bitbucket.org/ww/goautoneg       a547fc61f48d567d5b4ec6f8aee5573d8efce11d  https://github.com/rancher/goautoneg.git
 golang.org/x/sync                fd80eb99c8f653c847d294a001bdf2a3a6f768f5
+golang.org/x/tools               202502a5a9245830b5ec7b877e26b67760da8e67
 github.com/gorilla/mux           v1.6.1
+github.com/matryer/moq           ee5226d4300902ed04c84bde4837cb123d936feb https://github.com/rancher/moq

vendor/golang.org/x/tools/CONTRIBUTING.md

@@ -4,16 +4,15 @@ Go is an open source project.
 
 It is the work of hundreds of contributors. We appreciate your help!
 
-
 ## Filing issues
 
 When [filing an issue](https://golang.org/issue/new), make sure to answer these five questions:
 
-1. What version of Go are you using (`go version`)?
-2. What operating system and processor architecture are you using?
-3. What did you do?
-4. What did you expect to see?
-5. What did you see instead?
+1.  What version of Go are you using (`go version`)?
+2.  What operating system and processor architecture are you using?
+3.  What did you do?
+4.  What did you expect to see?
+5.  What did you see instead?
 
 General questions should go to the [golang-nuts mailing list](https://groups.google.com/group/golang-nuts) instead of the issue tracker.
 The gophers there will answer or ask you to file an issue if you've tripped over a bug.
@@ -23,9 +22,5 @@ The gophers there will answer or ask you to file an issue if you've tripped over
 Please read the [Contribution Guidelines](https://golang.org/doc/contribute.html)
 before sending patches.
 
-**We do not accept GitHub pull requests**
-(we use [Gerrit](https://code.google.com/p/gerrit/) instead for code review).
-
 Unless otherwise noted, the Go source files are distributed under
 the BSD-style license found in the LICENSE file.
-

vendor/golang.org/x/tools/README

@@ -1,10 +0,0 @@
-This subrepository holds the source for various packages and tools that support
-the Go programming language.
-
-Some of the tools, godoc and vet for example, are included in binary Go distributions.
-Others, including the Go guru and the test coverage tool, can be fetched with "go get".
-
-Packages include a type-checker for Go and an implementation of the
-Static Single Assignment form (SSA) representation for Go programs.
-
-To submit changes to this repository, see http://golang.org/doc/contribute.html.

vendor/golang.org/x/tools/README.md

@@ -0,0 +1,27 @@
+# Go Tools
+
+This subrepository holds the source for various packages and tools that support
+the Go programming language.
+
+Some of the tools, `godoc` and `vet` for example, are included in binary Go
+distributions.
+
+Others, including the Go `guru` and the test coverage tool, can be fetched with
+`go get`.
+
+Packages include a type-checker for Go and an implementation of the
+Static Single Assignment form (SSA) representation for Go programs.
+
+## Download/Install
+
+The easiest way to install is to run `go get -u golang.org/x/tools/...`. You can
+also manually git clone the repository to `$GOPATH/src/golang.org/x/tools`.
+
+## Report Issues / Send Patches
+
+This repository uses Gerrit for code changes. To learn how to submit changes to
+this repository, see https://golang.org/doc/contribute.html.
+
+The main issue tracker for the tools repository is located at
+https://github.com/golang/go/issues. Prefix your issue with "x/tools/(your
+subdir):" in the subject line, so it is easy to find.

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

@@ -0,0 +1,3 @@
+module golang.org/x/tools
+
+require golang.org/x/net v0.0.0-20190311183353-d8887717615a

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

@@ -0,0 +1,5 @@
+golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a h1:oWX7TPOiFAMXLq8o0ikBYfCJVlRHBcsciT5bXOrH628=
+golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

vendor/golang.org/x/tools/go/ast/astutil/imports.go

@@ -14,26 +14,26 @@ import (
 )
 
 // AddImport adds the import path to the file f, if absent.
-func AddImport(fset *token.FileSet, f *ast.File, ipath string) (added bool) {
-	return AddNamedImport(fset, f, "", ipath)
+func AddImport(fset *token.FileSet, f *ast.File, path string) (added bool) {
+	return AddNamedImport(fset, f, "", path)
 }
 
-// AddNamedImport adds the import path to the file f, if absent.
+// AddNamedImport adds the import with the given name and path to the file f, if absent.
 // If name is not empty, it is used to rename the import.
 //
 // For example, calling
 //	AddNamedImport(fset, f, "pathpkg", "path")
 // adds
 //	import pathpkg "path"
-func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added bool) {
-	if imports(f, ipath) {
+func AddNamedImport(fset *token.FileSet, f *ast.File, name, path string) (added bool) {
+	if imports(f, name, path) {
 		return false
 	}
 
 	newImport := &ast.ImportSpec{
 		Path: &ast.BasicLit{
 			Kind:  token.STRING,
-			Value: strconv.Quote(ipath),
+			Value: strconv.Quote(path),
 		},
 	}
 	if name != "" {
@@ -43,12 +43,14 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 	// Find an import decl to add to.
 	// The goal is to find an existing import
 	// whose import path has the longest shared
-	// prefix with ipath.
+	// prefix with path.
 	var (
 		bestMatch  = -1         // length of longest shared prefix
 		lastImport = -1         // index in f.Decls of the file's final import decl
 		impDecl    *ast.GenDecl // import decl containing the best match
 		impIndex   = -1         // spec index in impDecl containing the best match
+
+		isThirdPartyPath = isThirdParty(path)
 	)
 	for i, decl := range f.Decls {
 		gen, ok := decl.(*ast.GenDecl)
@@ -65,15 +67,27 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 				impDecl = gen
 			}
 
-			// Compute longest shared prefix with imports in this group.
+			// Compute longest shared prefix with imports in this group and find best
+			// matched import spec.
+			// 1. Always prefer import spec with longest shared prefix.
+			// 2. While match length is 0,
+			// - for stdlib package: prefer first import spec.
+			// - for third party package: prefer first third party import spec.
+			// We cannot use last import spec as best match for third party package
+			// because grouped imports are usually placed last by goimports -local
+			// flag.
+			// See issue #19190.
+			seenAnyThirdParty := false
 			for j, spec := range gen.Specs {
 				impspec := spec.(*ast.ImportSpec)
-				n := matchLen(importPath(impspec), ipath)
-				if n > bestMatch {
+				p := importPath(impspec)
+				n := matchLen(p, path)
+				if n > bestMatch || (bestMatch == 0 && !seenAnyThirdParty && isThirdPartyPath) {
 					bestMatch = n
 					impDecl = gen
 					impIndex = j
 				}
+				seenAnyThirdParty = seenAnyThirdParty || isThirdParty(p)
 			}
 		}
 	}
@@ -87,8 +101,8 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 			impDecl.TokPos = f.Decls[lastImport].End()
 		} else {
 			// There are no existing imports.
-			// Our new import goes after the package declaration and after
-			// the comment, if any, that starts on the same line as the
+			// Our new import, preceded by a blank line,  goes after the package declaration
+			// and after the comment, if any, that starts on the same line as the
 			// package declaration.
 			impDecl.TokPos = f.Package
 
@@ -98,7 +112,8 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 				if file.Line(c.Pos()) > pkgLine {
 					break
 				}
-				impDecl.TokPos = c.End()
+				// +2 for a blank line
+				impDecl.TokPos = c.End() + 2
 			}
 		}
 		f.Decls = append(f.Decls, nil)
@@ -175,12 +190,20 @@ func AddNamedImport(fset *token.FileSet, f *ast.File, name, ipath string) (added
 	return true
 }
 
+func isThirdParty(importPath string) bool {
+	// Third party package import path usually contains "." (".com", ".org", ...)
+	// This logic is taken from golang.org/x/tools/imports package.
+	return strings.Contains(importPath, ".")
+}
+
 // DeleteImport deletes the import path from the file f, if present.
+// If there are duplicate import declarations, all matching ones are deleted.
 func DeleteImport(fset *token.FileSet, f *ast.File, path string) (deleted bool) {
 	return DeleteNamedImport(fset, f, "", path)
 }
 
 // DeleteNamedImport deletes the import with the given name and path from the file f, if present.
+// If there are duplicate import declarations, all matching ones are deleted.
 func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (deleted bool) {
 	var delspecs []*ast.ImportSpec
 	var delcomments []*ast.CommentGroup
@@ -195,13 +218,7 @@ func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (del
 		for j := 0; j < len(gen.Specs); j++ {
 			spec := gen.Specs[j]
 			impspec := spec.(*ast.ImportSpec)
-			if impspec.Name == nil && name != "" {
-				continue
-			}
-			if impspec.Name != nil && impspec.Name.Name != name {
-				continue
-			}
-			if importPath(impspec) != path {
+			if importName(impspec) != name || importPath(impspec) != path {
 				continue
 			}
 
@@ -262,7 +279,7 @@ func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (del
 					// There was a blank line immediately preceding the deleted import,
 					// so there's no need to close the hole.
 					// Do nothing.
-				} else {
+				} else if line != fset.File(gen.Rparen).LineCount() {
 					// There was no blank line. Close the hole.
 					fset.File(gen.Rparen).MergeLine(line)
 				}
@@ -362,9 +379,14 @@ func (fn visitFn) Visit(node ast.Node) ast.Visitor {
 	return fn
 }
 
-// imports returns true if f imports path.
-func imports(f *ast.File, path string) bool {
-	return importSpec(f, path) != nil
+// imports reports whether f has an import with the specified name and path.
+func imports(f *ast.File, name, path string) bool {
+	for _, s := range f.Imports {
+		if importName(s) == name && importPath(s) == path {
+			return true
+		}
+	}
+	return false
 }
 
 // importSpec returns the import spec if f imports path,
@@ -378,14 +400,23 @@ func importSpec(f *ast.File, path string) *ast.ImportSpec {
 	return nil
 }
 
+// importName returns the name of s,
+// or "" if the import is not named.
+func importName(s *ast.ImportSpec) string {
+	if s.Name == nil {
+		return ""
+	}
+	return s.Name.Name
+}
+
 // importPath returns the unquoted import path of s,
 // or "" if the path is not properly quoted.
 func importPath(s *ast.ImportSpec) string {
 	t, err := strconv.Unquote(s.Path.Value)
-	if err == nil {
-		return t
+	if err != nil {
+		return ""
 	}
-	return ""
+	return t
 }
 
 // declImports reports whether gen contains an import of path.

vendor/golang.org/x/tools/go/ast/astutil/rewrite.go

@@ -0,0 +1,477 @@
+// Copyright 2017 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 astutil
+
+import (
+	"fmt"
+	"go/ast"
+	"reflect"
+	"sort"
+)
+
+// An ApplyFunc is invoked by Apply for each node n, even if n is nil,
+// before and/or after the node's children, using a Cursor describing
+// the current node and providing operations on it.
+//
+// The return value of ApplyFunc controls the syntax tree traversal.
+// See Apply for details.
+type ApplyFunc func(*Cursor) bool
+
+// Apply traverses a syntax tree recursively, starting with root,
+// and calling pre and post for each node as described below.
+// Apply returns the syntax tree, possibly modified.
+//
+// If pre is not nil, it is called for each node before the node's
+// children are traversed (pre-order). If pre returns false, no
+// children are traversed, and post is not called for that node.
+//
+// If post is not nil, and a prior call of pre didn't return false,
+// post is called for each node after its children are traversed
+// (post-order). If post returns false, traversal is terminated and
+// Apply returns immediately.
+//
+// Only fields that refer to AST nodes are considered children;
+// i.e., token.Pos, Scopes, Objects, and fields of basic types
+// (strings, etc.) are ignored.
+//
+// Children are traversed in the order in which they appear in the
+// respective node's struct definition. A package's files are
+// traversed in the filenames' alphabetical order.
+//
+func Apply(root ast.Node, pre, post ApplyFunc) (result ast.Node) {
+	parent := &struct{ ast.Node }{root}
+	defer func() {
+		if r := recover(); r != nil && r != abort {
+			panic(r)
+		}
+		result = parent.Node
+	}()
+	a := &application{pre: pre, post: post}
+	a.apply(parent, "Node", nil, root)
+	return
+}
+
+var abort = new(int) // singleton, to signal termination of Apply
+
+// A Cursor describes a node encountered during Apply.
+// Information about the node and its parent is available
+// from the Node, Parent, Name, and Index methods.
+//
+// If p is a variable of type and value of the current parent node
+// c.Parent(), and f is the field identifier with name c.Name(),
+// the following invariants hold:
+//
+//   p.f            == c.Node()  if c.Index() <  0
+//   p.f[c.Index()] == c.Node()  if c.Index() >= 0
+//
+// The methods Replace, Delete, InsertBefore, and InsertAfter
+// can be used to change the AST without disrupting Apply.
+type Cursor struct {
+	parent ast.Node
+	name   string
+	iter   *iterator // valid if non-nil
+	node   ast.Node
+}
+
+// Node returns the current Node.
+func (c *Cursor) Node() ast.Node { return c.node }
+
+// Parent returns the parent of the current Node.
+func (c *Cursor) Parent() ast.Node { return c.parent }
+
+// Name returns the name of the parent Node field that contains the current Node.
+// If the parent is a *ast.Package and the current Node is a *ast.File, Name returns
+// the filename for the current Node.
+func (c *Cursor) Name() string { return c.name }
+
+// Index reports the index >= 0 of the current Node in the slice of Nodes that
+// contains it, or a value < 0 if the current Node is not part of a slice.
+// The index of the current node changes if InsertBefore is called while
+// processing the current node.
+func (c *Cursor) Index() int {
+	if c.iter != nil {
+		return c.iter.index
+	}
+	return -1
+}
+
+// field returns the current node's parent field value.
+func (c *Cursor) field() reflect.Value {
+	return reflect.Indirect(reflect.ValueOf(c.parent)).FieldByName(c.name)
+}
+
+// Replace replaces the current Node with n.
+// The replacement node is not walked by Apply.
+func (c *Cursor) Replace(n ast.Node) {
+	if _, ok := c.node.(*ast.File); ok {
+		file, ok := n.(*ast.File)
+		if !ok {
+			panic("attempt to replace *ast.File with non-*ast.File")
+		}
+		c.parent.(*ast.Package).Files[c.name] = file
+		return
+	}
+
+	v := c.field()
+	if i := c.Index(); i >= 0 {
+		v = v.Index(i)
+	}
+	v.Set(reflect.ValueOf(n))
+}
+
+// Delete deletes the current Node from its containing slice.
+// If the current Node is not part of a slice, Delete panics.
+// As a special case, if the current node is a package file,
+// Delete removes it from the package's Files map.
+func (c *Cursor) Delete() {
+	if _, ok := c.node.(*ast.File); ok {
+		delete(c.parent.(*ast.Package).Files, c.name)
+		return
+	}
+
+	i := c.Index()
+	if i < 0 {
+		panic("Delete node not contained in slice")
+	}
+	v := c.field()
+	l := v.Len()
+	reflect.Copy(v.Slice(i, l), v.Slice(i+1, l))
+	v.Index(l - 1).Set(reflect.Zero(v.Type().Elem()))
+	v.SetLen(l - 1)
+	c.iter.step--
+}
+
+// InsertAfter inserts n after the current Node in its containing slice.
+// If the current Node is not part of a slice, InsertAfter panics.
+// Apply does not walk n.
+func (c *Cursor) InsertAfter(n ast.Node) {
+	i := c.Index()
+	if i < 0 {
+		panic("InsertAfter node not contained in slice")
+	}
+	v := c.field()
+	v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem())))
+	l := v.Len()
+	reflect.Copy(v.Slice(i+2, l), v.Slice(i+1, l))
+	v.Index(i + 1).Set(reflect.ValueOf(n))
+	c.iter.step++
+}
+
+// InsertBefore inserts n before the current Node in its containing slice.
+// If the current Node is not part of a slice, InsertBefore panics.
+// Apply will not walk n.
+func (c *Cursor) InsertBefore(n ast.Node) {
+	i := c.Index()
+	if i < 0 {
+		panic("InsertBefore node not contained in slice")
+	}
+	v := c.field()
+	v.Set(reflect.Append(v, reflect.Zero(v.Type().Elem())))
+	l := v.Len()
+	reflect.Copy(v.Slice(i+1, l), v.Slice(i, l))
+	v.Index(i).Set(reflect.ValueOf(n))
+	c.iter.index++
+}
+
+// application carries all the shared data so we can pass it around cheaply.
+type application struct {
+	pre, post ApplyFunc
+	cursor    Cursor
+	iter      iterator
+}
+
+func (a *application) apply(parent ast.Node, name string, iter *iterator, n ast.Node) {
+	// convert typed nil into untyped nil
+	if v := reflect.ValueOf(n); v.Kind() == reflect.Ptr && v.IsNil() {
+		n = nil
+	}
+
+	// avoid heap-allocating a new cursor for each apply call; reuse a.cursor instead
+	saved := a.cursor
+	a.cursor.parent = parent
+	a.cursor.name = name
+	a.cursor.iter = iter
+	a.cursor.node = n
+
+	if a.pre != nil && !a.pre(&a.cursor) {
+		a.cursor = saved
+		return
+	}
+
+	// walk children
+	// (the order of the cases matches the order of the corresponding node types in go/ast)
+	switch n := n.(type) {
+	case nil:
+		// nothing to do
+
+	// Comments and fields
+	case *ast.Comment:
+		// nothing to do
+
+	case *ast.CommentGroup:
+		if n != nil {
+			a.applyList(n, "List")
+		}
+
+	case *ast.Field:
+		a.apply(n, "Doc", nil, n.Doc)
+		a.applyList(n, "Names")
+		a.apply(n, "Type", nil, n.Type)
+		a.apply(n, "Tag", nil, n.Tag)
+		a.apply(n, "Comment", nil, n.Comment)
+
+	case *ast.FieldList:
+		a.applyList(n, "List")
+
+	// Expressions
+	case *ast.BadExpr, *ast.Ident, *ast.BasicLit:
+		// nothing to do
+
+	case *ast.Ellipsis:
+		a.apply(n, "Elt", nil, n.Elt)
+
+	case *ast.FuncLit:
+		a.apply(n, "Type", nil, n.Type)
+		a.apply(n, "Body", nil, n.Body)
+
+	case *ast.CompositeLit:
+		a.apply(n, "Type", nil, n.Type)
+		a.applyList(n, "Elts")
+
+	case *ast.ParenExpr:
+		a.apply(n, "X", nil, n.X)
+
+	case *ast.SelectorExpr:
+		a.apply(n, "X", nil, n.X)
+		a.apply(n, "Sel", nil, n.Sel)
+
+	case *ast.IndexExpr:
+		a.apply(n, "X", nil, n.X)
+		a.apply(n, "Index", nil, n.Index)
+
+	case *ast.SliceExpr:
+		a.apply(n, "X", nil, n.X)
+		a.apply(n, "Low", nil, n.Low)
+		a.apply(n, "High", nil, n.High)
+		a.apply(n, "Max", nil, n.Max)
+
+	case *ast.TypeAssertExpr:
+		a.apply(n, "X", nil, n.X)
+		a.apply(n, "Type", nil, n.Type)
+
+	case *ast.CallExpr:
+		a.apply(n, "Fun", nil, n.Fun)
+		a.applyList(n, "Args")
+
+	case *ast.StarExpr:
+		a.apply(n, "X", nil, n.X)
+
+	case *ast.UnaryExpr:
+		a.apply(n, "X", nil, n.X)
+
+	case *ast.BinaryExpr:
+		a.apply(n, "X", nil, n.X)
+		a.apply(n, "Y", nil, n.Y)
+
+	case *ast.KeyValueExpr:
+		a.apply(n, "Key", nil, n.Key)
+		a.apply(n, "Value", nil, n.Value)
+
+	// Types
+	case *ast.ArrayType:
+		a.apply(n, "Len", nil, n.Len)
+		a.apply(n, "Elt", nil, n.Elt)
+
+	case *ast.StructType:
+		a.apply(n, "Fields", nil, n.Fields)
+
+	case *ast.FuncType:
+		a.apply(n, "Params", nil, n.Params)
+		a.apply(n, "Results", nil, n.Results)
+
+	case *ast.InterfaceType:
+		a.apply(n, "Methods", nil, n.Methods)
+
+	case *ast.MapType:
+		a.apply(n, "Key", nil, n.Key)
+		a.apply(n, "Value", nil, n.Value)
+
+	case *ast.ChanType:
+		a.apply(n, "Value", nil, n.Value)
+
+	// Statements
+	case *ast.BadStmt:
+		// nothing to do
+
+	case *ast.DeclStmt:
+		a.apply(n, "Decl", nil, n.Decl)
+
+	case *ast.EmptyStmt:
+		// nothing to do
+
+	case *ast.LabeledStmt:
+		a.apply(n, "Label", nil, n.Label)
+		a.apply(n, "Stmt", nil, n.Stmt)
+
+	case *ast.ExprStmt:
+		a.apply(n, "X", nil, n.X)
+
+	case *ast.SendStmt:
+		a.apply(n, "Chan", nil, n.Chan)
+		a.apply(n, "Value", nil, n.Value)
+
+	case *ast.IncDecStmt:
+		a.apply(n, "X", nil, n.X)
+
+	case *ast.AssignStmt:
+		a.applyList(n, "Lhs")
+		a.applyList(n, "Rhs")
+
+	case *ast.GoStmt:
+		a.apply(n, "Call", nil, n.Call)
+
+	case *ast.DeferStmt:
+		a.apply(n, "Call", nil, n.Call)
+
+	case *ast.ReturnStmt:
+		a.applyList(n, "Results")
+
+	case *ast.BranchStmt:
+		a.apply(n, "Label", nil, n.Label)
+
+	case *ast.BlockStmt:
+		a.applyList(n, "List")
+
+	case *ast.IfStmt:
+		a.apply(n, "Init", nil, n.Init)
+		a.apply(n, "Cond", nil, n.Cond)
+		a.apply(n, "Body", nil, n.Body)
+		a.apply(n, "Else", nil, n.Else)
+
+	case *ast.CaseClause:
+		a.applyList(n, "List")
+		a.applyList(n, "Body")
+
+	case *ast.SwitchStmt:
+		a.apply(n, "Init", nil, n.Init)
+		a.apply(n, "Tag", nil, n.Tag)
+		a.apply(n, "Body", nil, n.Body)
+
+	case *ast.TypeSwitchStmt:
+		a.apply(n, "Init", nil, n.Init)
+		a.apply(n, "Assign", nil, n.Assign)
+		a.apply(n, "Body", nil, n.Body)
+
+	case *ast.CommClause:
+		a.apply(n, "Comm", nil, n.Comm)
+		a.applyList(n, "Body")
+
+	case *ast.SelectStmt:
+		a.apply(n, "Body", nil, n.Body)
+
+	case *ast.ForStmt:
+		a.apply(n, "Init", nil, n.Init)
+		a.apply(n, "Cond", nil, n.Cond)
+		a.apply(n, "Post", nil, n.Post)
+		a.apply(n, "Body", nil, n.Body)
+
+	case *ast.RangeStmt:
+		a.apply(n, "Key", nil, n.Key)
+		a.apply(n, "Value", nil, n.Value)
+		a.apply(n, "X", nil, n.X)
+		a.apply(n, "Body", nil, n.Body)
+
+	// Declarations
+	case *ast.ImportSpec:
+		a.apply(n, "Doc", nil, n.Doc)
+		a.apply(n, "Name", nil, n.Name)
+		a.apply(n, "Path", nil, n.Path)
+		a.apply(n, "Comment", nil, n.Comment)
+
+	case *ast.ValueSpec:
+		a.apply(n, "Doc", nil, n.Doc)
+		a.applyList(n, "Names")
+		a.apply(n, "Type", nil, n.Type)
+		a.applyList(n, "Values")
+		a.apply(n, "Comment", nil, n.Comment)
+
+	case *ast.TypeSpec:
+		a.apply(n, "Doc", nil, n.Doc)
+		a.apply(n, "Name", nil, n.Name)
+		a.apply(n, "Type", nil, n.Type)
+		a.apply(n, "Comment", nil, n.Comment)
+
+	case *ast.BadDecl:
+		// nothing to do
+
+	case *ast.GenDecl:
+		a.apply(n, "Doc", nil, n.Doc)
+		a.applyList(n, "Specs")
+
+	case *ast.FuncDecl:
+		a.apply(n, "Doc", nil, n.Doc)
+		a.apply(n, "Recv", nil, n.Recv)
+		a.apply(n, "Name", nil, n.Name)
+		a.apply(n, "Type", nil, n.Type)
+		a.apply(n, "Body", nil, n.Body)
+
+	// Files and packages
+	case *ast.File:
+		a.apply(n, "Doc", nil, n.Doc)
+		a.apply(n, "Name", nil, n.Name)
+		a.applyList(n, "Decls")
+		// Don't walk n.Comments; they have either been walked already if
+		// they are Doc comments, or they can be easily walked explicitly.
+
+	case *ast.Package:
+		// collect and sort names for reproducible behavior
+		var names []string
+		for name := range n.Files {
+			names = append(names, name)
+		}
+		sort.Strings(names)
+		for _, name := range names {
+			a.apply(n, name, nil, n.Files[name])
+		}
+
+	default:
+		panic(fmt.Sprintf("Apply: unexpected node type %T", n))
+	}
+
+	if a.post != nil && !a.post(&a.cursor) {
+		panic(abort)
+	}
+
+	a.cursor = saved
+}
+
+// An iterator controls iteration over a slice of nodes.
+type iterator struct {
+	index, step int
+}
+
+func (a *application) applyList(parent ast.Node, name string) {
+	// avoid heap-allocating a new iterator for each applyList call; reuse a.iter instead
+	saved := a.iter
+	a.iter.index = 0
+	for {
+		// must reload parent.name each time, since cursor modifications might change it
+		v := reflect.Indirect(reflect.ValueOf(parent)).FieldByName(name)
+		if a.iter.index >= v.Len() {
+			break
+		}
+
+		// element x may be nil in a bad AST - be cautious
+		var x ast.Node
+		if e := v.Index(a.iter.index); e.IsValid() {
+			x = e.Interface().(ast.Node)
+		}
+
+		a.iter.step = 1
+		a.apply(parent, name, &a.iter, x)
+		a.iter.index += a.iter.step
+	}
+	a.iter = saved
+}

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

@@ -0,0 +1,109 @@
+// Copyright 2016 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 gcexportdata provides functions for locating, reading, and
+// writing export data files containing type information produced by the
+// gc compiler.  This package supports go1.7 export data format and all
+// later versions.
+//
+// Although it might seem convenient for this package to live alongside
+// go/types in the standard library, this would cause version skew
+// problems for developer tools that use it, since they must be able to
+// consume the outputs of the gc compiler both before and after a Go
+// update such as from Go 1.7 to Go 1.8.  Because this package lives in
+// golang.org/x/tools, sites can update their version of this repo some
+// time before the Go 1.8 release and rebuild and redeploy their
+// developer tools, which will then be able to consume both Go 1.7 and
+// Go 1.8 export data files, so they will work before and after the
+// Go update. (See discussion at https://golang.org/issue/15651.)
+//
+package gcexportdata // import "golang.org/x/tools/go/gcexportdata"
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"go/token"
+	"go/types"
+	"io"
+	"io/ioutil"
+
+	"golang.org/x/tools/go/internal/gcimporter"
+)
+
+// Find returns the name of an object (.o) or archive (.a) file
+// containing type information for the specified import path,
+// using the workspace layout conventions of go/build.
+// If no file was found, an empty filename is returned.
+//
+// A relative srcDir is interpreted relative to the current working directory.
+//
+// Find also returns the package's resolved (canonical) import path,
+// reflecting the effects of srcDir and vendoring on importPath.
+func Find(importPath, srcDir string) (filename, path string) {
+	return gcimporter.FindPkg(importPath, srcDir)
+}
+
+// NewReader returns a reader for the export data section of an object
+// (.o) or archive (.a) file read from r.  The new reader may provide
+// additional trailing data beyond the end of the export data.
+func NewReader(r io.Reader) (io.Reader, error) {
+	buf := bufio.NewReader(r)
+	_, err := gcimporter.FindExportData(buf)
+	// If we ever switch to a zip-like archive format with the ToC
+	// at the end, we can return the correct portion of export data,
+	// but for now we must return the entire rest of the file.
+	return buf, err
+}
+
+// Read reads export data from in, decodes it, and returns type
+// information for the package.
+// The package name is specified by path.
+// File position information is added to fset.
+//
+// Read may inspect and add to the imports map to ensure that references
+// within the export data to other packages are consistent.  The caller
+// must ensure that imports[path] does not exist, or exists but is
+// incomplete (see types.Package.Complete), and Read inserts the
+// resulting package into this map entry.
+//
+// On return, the state of the reader is undefined.
+func Read(in io.Reader, fset *token.FileSet, imports map[string]*types.Package, path string) (*types.Package, error) {
+	data, err := ioutil.ReadAll(in)
+	if err != nil {
+		return nil, fmt.Errorf("reading export data for %q: %v", path, err)
+	}
+
+	if bytes.HasPrefix(data, []byte("!<arch>")) {
+		return nil, fmt.Errorf("can't read export data for %q directly from an archive file (call gcexportdata.NewReader first to extract export data)", path)
+	}
+
+	// The App Engine Go runtime v1.6 uses the old export data format.
+	// TODO(adonovan): delete once v1.7 has been around for a while.
+	if bytes.HasPrefix(data, []byte("package ")) {
+		return gcimporter.ImportData(imports, path, path, bytes.NewReader(data))
+	}
+
+	// The indexed export format starts with an 'i'; the older
+	// binary export format starts with a 'c', 'd', or 'v'
+	// (from "version"). Select appropriate importer.
+	if len(data) > 0 && data[0] == 'i' {
+		_, pkg, err := gcimporter.IImportData(fset, imports, data[1:], path)
+		return pkg, err
+	}
+
+	_, pkg, err := gcimporter.BImportData(fset, imports, data, path)
+	return pkg, err
+}
+
+// Write writes encoded type information for the specified package to out.
+// The FileSet provides file position information for named objects.
+func Write(out io.Writer, fset *token.FileSet, pkg *types.Package) error {
+	b, err := gcimporter.BExportData(fset, pkg)
+	if err != nil {
+		return err
+	}
+	_, err = out.Write(b)
+	return err
+}

vendor/golang.org/x/tools/go/gcexportdata/importer.go

@@ -0,0 +1,73 @@
+// Copyright 2016 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 gcexportdata
+
+import (
+	"fmt"
+	"go/token"
+	"go/types"
+	"os"
+)
+
+// NewImporter returns a new instance of the types.Importer interface
+// that reads type information from export data files written by gc.
+// The Importer also satisfies types.ImporterFrom.
+//
+// Export data files are located using "go build" workspace conventions
+// and the build.Default context.
+//
+// Use this importer instead of go/importer.For("gc", ...) to avoid the
+// version-skew problems described in the documentation of this package,
+// or to control the FileSet or access the imports map populated during
+// package loading.
+//
+func NewImporter(fset *token.FileSet, imports map[string]*types.Package) types.ImporterFrom {
+	return importer{fset, imports}
+}
+
+type importer struct {
+	fset    *token.FileSet
+	imports map[string]*types.Package
+}
+
+func (imp importer) Import(importPath string) (*types.Package, error) {
+	return imp.ImportFrom(importPath, "", 0)
+}
+
+func (imp importer) ImportFrom(importPath, srcDir string, mode types.ImportMode) (_ *types.Package, err error) {
+	filename, path := Find(importPath, srcDir)
+	if filename == "" {
+		if importPath == "unsafe" {
+			// Even for unsafe, call Find first in case
+			// the package was vendored.
+			return types.Unsafe, nil
+		}
+		return nil, fmt.Errorf("can't find import: %s", importPath)
+	}
+
+	if pkg, ok := imp.imports[path]; ok && pkg.Complete() {
+		return pkg, nil // cache hit
+	}
+
+	// open file
+	f, err := os.Open(filename)
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		f.Close()
+		if err != nil {
+			// add file name to error
+			err = fmt.Errorf("reading export data: %s: %v", filename, err)
+		}
+	}()
+
+	r, err := NewReader(f)
+	if err != nil {
+		return nil, err
+	}
+
+	return Read(r, imp.fset, imp.imports, path)
+}

vendor/golang.org/x/tools/go/gcexportdata/main.go

@@ -0,0 +1,99 @@
+// Copyright 2017 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.
+
+// +build ignore
+
+// The gcexportdata command is a diagnostic tool that displays the
+// contents of gc export data files.
+package main
+
+import (
+	"flag"
+	"fmt"
+	"go/token"
+	"go/types"
+	"log"
+	"os"
+
+	"golang.org/x/tools/go/gcexportdata"
+	"golang.org/x/tools/go/types/typeutil"
+)
+
+var packageFlag = flag.String("package", "", "alternative package to print")
+
+func main() {
+	log.SetPrefix("gcexportdata: ")
+	log.SetFlags(0)
+	flag.Usage = func() {
+		fmt.Fprintln(os.Stderr, "usage: gcexportdata [-package path] file.a")
+	}
+	flag.Parse()
+	if flag.NArg() != 1 {
+		flag.Usage()
+		os.Exit(2)
+	}
+	filename := flag.Args()[0]
+
+	f, err := os.Open(filename)
+	if err != nil {
+		log.Fatal(err)
+	}
+
+	r, err := gcexportdata.NewReader(f)
+	if err != nil {
+		log.Fatalf("%s: %s", filename, err)
+	}
+
+	// Decode the package.
+	const primary = "<primary>"
+	imports := make(map[string]*types.Package)
+	fset := token.NewFileSet()
+	pkg, err := gcexportdata.Read(r, fset, imports, primary)
+	if err != nil {
+		log.Fatalf("%s: %s", filename, err)
+	}
+
+	// Optionally select an indirectly mentioned package.
+	if *packageFlag != "" {
+		pkg = imports[*packageFlag]
+		if pkg == nil {
+			fmt.Fprintf(os.Stderr, "export data file %s does not mention %s; has:\n",
+				filename, *packageFlag)
+			for p := range imports {
+				if p != primary {
+					fmt.Fprintf(os.Stderr, "\t%s\n", p)
+				}
+			}
+			os.Exit(1)
+		}
+	}
+
+	// Print all package-level declarations, including non-exported ones.
+	fmt.Printf("package %s\n", pkg.Name())
+	for _, imp := range pkg.Imports() {
+		fmt.Printf("import %q\n", imp.Path())
+	}
+	qual := func(p *types.Package) string {
+		if pkg == p {
+			return ""
+		}
+		return p.Name()
+	}
+	scope := pkg.Scope()
+	for _, name := range scope.Names() {
+		obj := scope.Lookup(name)
+		fmt.Printf("%s: %s\n",
+			fset.Position(obj.Pos()),
+			types.ObjectString(obj, qual))
+
+		// For types, print each method.
+		if _, ok := obj.(*types.TypeName); ok {
+			for _, method := range typeutil.IntuitiveMethodSet(obj.Type(), nil) {
+				fmt.Printf("%s: %s\n",
+					fset.Position(method.Obj().Pos()),
+					types.SelectionString(method, qual))
+			}
+		}
+	}
+}

vendor/golang.org/x/tools/go/internal/gcimporter/bexport.go

@@ -0,0 +1,852 @@
+// Copyright 2016 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.
+
+// Binary package export.
+// This file was derived from $GOROOT/src/cmd/compile/internal/gc/bexport.go;
+// see that file for specification of the format.
+
+package gcimporter
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"go/ast"
+	"go/constant"
+	"go/token"
+	"go/types"
+	"math"
+	"math/big"
+	"sort"
+	"strings"
+)
+
+// If debugFormat is set, each integer and string value is preceded by a marker
+// and position information in the encoding. This mechanism permits an importer
+// to recognize immediately when it is out of sync. The importer recognizes this
+// mode automatically (i.e., it can import export data produced with debugging
+// support even if debugFormat is not set at the time of import). This mode will
+// lead to massively larger export data (by a factor of 2 to 3) and should only
+// be enabled during development and debugging.
+//
+// NOTE: This flag is the first flag to enable if importing dies because of
+// (suspected) format errors, and whenever a change is made to the format.
+const debugFormat = false // default: false
+
+// If trace is set, debugging output is printed to std out.
+const trace = false // default: false
+
+// Current export format version. Increase with each format change.
+// Note: The latest binary (non-indexed) export format is at version 6.
+//       This exporter is still at level 4, but it doesn't matter since
+//       the binary importer can handle older versions just fine.
+// 6: package height (CL 105038) -- NOT IMPLEMENTED HERE
+// 5: improved position encoding efficiency (issue 20080, CL 41619) -- NOT IMPLEMEMTED HERE
+// 4: type name objects support type aliases, uses aliasTag
+// 3: Go1.8 encoding (same as version 2, aliasTag defined but never used)
+// 2: removed unused bool in ODCL export (compiler only)
+// 1: header format change (more regular), export package for _ struct fields
+// 0: Go1.7 encoding
+const exportVersion = 4
+
+// trackAllTypes enables cycle tracking for all types, not just named
+// types. The existing compiler invariants assume that unnamed types
+// that are not completely set up are not used, or else there are spurious
+// errors.
+// If disabled, only named types are tracked, possibly leading to slightly
+// less efficient encoding in rare cases. It also prevents the export of
+// some corner-case type declarations (but those are not handled correctly
+// with with the textual export format either).
+// TODO(gri) enable and remove once issues caused by it are fixed
+const trackAllTypes = false
+
+type exporter struct {
+	fset *token.FileSet
+	out  bytes.Buffer
+
+	// object -> index maps, indexed in order of serialization
+	strIndex map[string]int
+	pkgIndex map[*types.Package]int
+	typIndex map[types.Type]int
+
+	// position encoding
+	posInfoFormat bool
+	prevFile      string
+	prevLine      int
+
+	// debugging support
+	written int // bytes written
+	indent  int // for trace
+}
+
+// internalError represents an error generated inside this package.
+type internalError string
+
+func (e internalError) Error() string { return "gcimporter: " + string(e) }
+
+func internalErrorf(format string, args ...interface{}) error {
+	return internalError(fmt.Sprintf(format, args...))
+}
+
+// BExportData returns binary export data for pkg.
+// If no file set is provided, position info will be missing.
+func BExportData(fset *token.FileSet, pkg *types.Package) (b []byte, err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			if ierr, ok := e.(internalError); ok {
+				err = ierr
+				return
+			}
+			// Not an internal error; panic again.
+			panic(e)
+		}
+	}()
+
+	p := exporter{
+		fset:          fset,
+		strIndex:      map[string]int{"": 0}, // empty string is mapped to 0
+		pkgIndex:      make(map[*types.Package]int),
+		typIndex:      make(map[types.Type]int),
+		posInfoFormat: true, // TODO(gri) might become a flag, eventually
+	}
+
+	// write version info
+	// The version string must start with "version %d" where %d is the version
+	// number. Additional debugging information may follow after a blank; that
+	// text is ignored by the importer.
+	p.rawStringln(fmt.Sprintf("version %d", exportVersion))
+	var debug string
+	if debugFormat {
+		debug = "debug"
+	}
+	p.rawStringln(debug) // cannot use p.bool since it's affected by debugFormat; also want to see this clearly
+	p.bool(trackAllTypes)
+	p.bool(p.posInfoFormat)
+
+	// --- generic export data ---
+
+	// populate type map with predeclared "known" types
+	for index, typ := range predeclared() {
+		p.typIndex[typ] = index
+	}
+	if len(p.typIndex) != len(predeclared()) {
+		return nil, internalError("duplicate entries in type map?")
+	}
+
+	// write package data
+	p.pkg(pkg, true)
+	if trace {
+		p.tracef("\n")
+	}
+
+	// write objects
+	objcount := 0
+	scope := pkg.Scope()
+	for _, name := range scope.Names() {
+		if !ast.IsExported(name) {
+			continue
+		}
+		if trace {
+			p.tracef("\n")
+		}
+		p.obj(scope.Lookup(name))
+		objcount++
+	}
+
+	// indicate end of list
+	if trace {
+		p.tracef("\n")
+	}
+	p.tag(endTag)
+
+	// for self-verification only (redundant)
+	p.int(objcount)
+
+	if trace {
+		p.tracef("\n")
+	}
+
+	// --- end of export data ---
+
+	return p.out.Bytes(), nil
+}
+
+func (p *exporter) pkg(pkg *types.Package, emptypath bool) {
+	if pkg == nil {
+		panic(internalError("unexpected nil pkg"))
+	}
+
+	// if we saw the package before, write its index (>= 0)
+	if i, ok := p.pkgIndex[pkg]; ok {
+		p.index('P', i)
+		return
+	}
+
+	// otherwise, remember the package, write the package tag (< 0) and package data
+	if trace {
+		p.tracef("P%d = { ", len(p.pkgIndex))
+		defer p.tracef("} ")
+	}
+	p.pkgIndex[pkg] = len(p.pkgIndex)
+
+	p.tag(packageTag)
+	p.string(pkg.Name())
+	if emptypath {
+		p.string("")
+	} else {
+		p.string(pkg.Path())
+	}
+}
+
+func (p *exporter) obj(obj types.Object) {
+	switch obj := obj.(type) {
+	case *types.Const:
+		p.tag(constTag)
+		p.pos(obj)
+		p.qualifiedName(obj)
+		p.typ(obj.Type())
+		p.value(obj.Val())
+
+	case *types.TypeName:
+		if obj.IsAlias() {
+			p.tag(aliasTag)
+			p.pos(obj)
+			p.qualifiedName(obj)
+		} else {
+			p.tag(typeTag)
+		}
+		p.typ(obj.Type())
+
+	case *types.Var:
+		p.tag(varTag)
+		p.pos(obj)
+		p.qualifiedName(obj)
+		p.typ(obj.Type())
+
+	case *types.Func:
+		p.tag(funcTag)
+		p.pos(obj)
+		p.qualifiedName(obj)
+		sig := obj.Type().(*types.Signature)
+		p.paramList(sig.Params(), sig.Variadic())
+		p.paramList(sig.Results(), false)
+
+	default:
+		panic(internalErrorf("unexpected object %v (%T)", obj, obj))
+	}
+}
+
+func (p *exporter) pos(obj types.Object) {
+	if !p.posInfoFormat {
+		return
+	}
+
+	file, line := p.fileLine(obj)
+	if file == p.prevFile {
+		// common case: write line delta
+		// delta == 0 means different file or no line change
+		delta := line - p.prevLine
+		p.int(delta)
+		if delta == 0 {
+			p.int(-1) // -1 means no file change
+		}
+	} else {
+		// different file
+		p.int(0)
+		// Encode filename as length of common prefix with previous
+		// filename, followed by (possibly empty) suffix. Filenames
+		// frequently share path prefixes, so this can save a lot
+		// of space and make export data size less dependent on file
+		// path length. The suffix is unlikely to be empty because
+		// file names tend to end in ".go".
+		n := commonPrefixLen(p.prevFile, file)
+		p.int(n)           // n >= 0
+		p.string(file[n:]) // write suffix only
+		p.prevFile = file
+		p.int(line)
+	}
+	p.prevLine = line
+}
+
+func (p *exporter) fileLine(obj types.Object) (file string, line int) {
+	if p.fset != nil {
+		pos := p.fset.Position(obj.Pos())
+		file = pos.Filename
+		line = pos.Line
+	}
+	return
+}
+
+func commonPrefixLen(a, b string) int {
+	if len(a) > len(b) {
+		a, b = b, a
+	}
+	// len(a) <= len(b)
+	i := 0
+	for i < len(a) && a[i] == b[i] {
+		i++
+	}
+	return i
+}
+
+func (p *exporter) qualifiedName(obj types.Object) {
+	p.string(obj.Name())
+	p.pkg(obj.Pkg(), false)
+}
+
+func (p *exporter) typ(t types.Type) {
+	if t == nil {
+		panic(internalError("nil type"))
+	}
+
+	// Possible optimization: Anonymous pointer types *T where
+	// T is a named type are common. We could canonicalize all
+	// such types *T to a single type PT = *T. This would lead
+	// to at most one *T entry in typIndex, and all future *T's
+	// would be encoded as the respective index directly. Would
+	// save 1 byte (pointerTag) per *T and reduce the typIndex
+	// size (at the cost of a canonicalization map). We can do
+	// this later, without encoding format change.
+
+	// if we saw the type before, write its index (>= 0)
+	if i, ok := p.typIndex[t]; ok {
+		p.index('T', i)
+		return
+	}
+
+	// otherwise, remember the type, write the type tag (< 0) and type data
+	if trackAllTypes {
+		if trace {
+			p.tracef("T%d = {>\n", len(p.typIndex))
+			defer p.tracef("<\n} ")
+		}
+		p.typIndex[t] = len(p.typIndex)
+	}
+
+	switch t := t.(type) {
+	case *types.Named:
+		if !trackAllTypes {
+			// if we don't track all types, track named types now
+			p.typIndex[t] = len(p.typIndex)
+		}
+
+		p.tag(namedTag)
+		p.pos(t.Obj())
+		p.qualifiedName(t.Obj())
+		p.typ(t.Underlying())
+		if !types.IsInterface(t) {
+			p.assocMethods(t)
+		}
+
+	case *types.Array:
+		p.tag(arrayTag)
+		p.int64(t.Len())
+		p.typ(t.Elem())
+
+	case *types.Slice:
+		p.tag(sliceTag)
+		p.typ(t.Elem())
+
+	case *dddSlice:
+		p.tag(dddTag)
+		p.typ(t.elem)
+
+	case *types.Struct:
+		p.tag(structTag)
+		p.fieldList(t)
+
+	case *types.Pointer:
+		p.tag(pointerTag)
+		p.typ(t.Elem())
+
+	case *types.Signature:
+		p.tag(signatureTag)
+		p.paramList(t.Params(), t.Variadic())
+		p.paramList(t.Results(), false)
+
+	case *types.Interface:
+		p.tag(interfaceTag)
+		p.iface(t)
+
+	case *types.Map:
+		p.tag(mapTag)
+		p.typ(t.Key())
+		p.typ(t.Elem())
+
+	case *types.Chan:
+		p.tag(chanTag)
+		p.int(int(3 - t.Dir())) // hack
+		p.typ(t.Elem())
+
+	default:
+		panic(internalErrorf("unexpected type %T: %s", t, t))
+	}
+}
+
+func (p *exporter) assocMethods(named *types.Named) {
+	// Sort methods (for determinism).
+	var methods []*types.Func
+	for i := 0; i < named.NumMethods(); i++ {
+		methods = append(methods, named.Method(i))
+	}
+	sort.Sort(methodsByName(methods))
+
+	p.int(len(methods))
+
+	if trace && methods != nil {
+		p.tracef("associated methods {>\n")
+	}
+
+	for i, m := range methods {
+		if trace && i > 0 {
+			p.tracef("\n")
+		}
+
+		p.pos(m)
+		name := m.Name()
+		p.string(name)
+		if !exported(name) {
+			p.pkg(m.Pkg(), false)
+		}
+
+		sig := m.Type().(*types.Signature)
+		p.paramList(types.NewTuple(sig.Recv()), false)
+		p.paramList(sig.Params(), sig.Variadic())
+		p.paramList(sig.Results(), false)
+		p.int(0) // dummy value for go:nointerface pragma - ignored by importer
+	}
+
+	if trace && methods != nil {
+		p.tracef("<\n} ")
+	}
+}
+
+type methodsByName []*types.Func
+
+func (x methodsByName) Len() int           { return len(x) }
+func (x methodsByName) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+func (x methodsByName) Less(i, j int) bool { return x[i].Name() < x[j].Name() }
+
+func (p *exporter) fieldList(t *types.Struct) {
+	if trace && t.NumFields() > 0 {
+		p.tracef("fields {>\n")
+		defer p.tracef("<\n} ")
+	}
+
+	p.int(t.NumFields())
+	for i := 0; i < t.NumFields(); i++ {
+		if trace && i > 0 {
+			p.tracef("\n")
+		}
+		p.field(t.Field(i))
+		p.string(t.Tag(i))
+	}
+}
+
+func (p *exporter) field(f *types.Var) {
+	if !f.IsField() {
+		panic(internalError("field expected"))
+	}
+
+	p.pos(f)
+	p.fieldName(f)
+	p.typ(f.Type())
+}
+
+func (p *exporter) iface(t *types.Interface) {
+	// TODO(gri): enable importer to load embedded interfaces,
+	// then emit Embeddeds and ExplicitMethods separately here.
+	p.int(0)
+
+	n := t.NumMethods()
+	if trace && n > 0 {
+		p.tracef("methods {>\n")
+		defer p.tracef("<\n} ")
+	}
+	p.int(n)
+	for i := 0; i < n; i++ {
+		if trace && i > 0 {
+			p.tracef("\n")
+		}
+		p.method(t.Method(i))
+	}
+}
+
+func (p *exporter) method(m *types.Func) {
+	sig := m.Type().(*types.Signature)
+	if sig.Recv() == nil {
+		panic(internalError("method expected"))
+	}
+
+	p.pos(m)
+	p.string(m.Name())
+	if m.Name() != "_" && !ast.IsExported(m.Name()) {
+		p.pkg(m.Pkg(), false)
+	}
+
+	// interface method; no need to encode receiver.
+	p.paramList(sig.Params(), sig.Variadic())
+	p.paramList(sig.Results(), false)
+}
+
+func (p *exporter) fieldName(f *types.Var) {
+	name := f.Name()
+
+	if f.Anonymous() {
+		// anonymous field - we distinguish between 3 cases:
+		// 1) field name matches base type name and is exported
+		// 2) field name matches base type name and is not exported
+		// 3) field name doesn't match base type name (alias name)
+		bname := basetypeName(f.Type())
+		if name == bname {
+			if ast.IsExported(name) {
+				name = "" // 1) we don't need to know the field name or package
+			} else {
+				name = "?" // 2) use unexported name "?" to force package export
+			}
+		} else {
+			// 3) indicate alias and export name as is
+			// (this requires an extra "@" but this is a rare case)
+			p.string("@")
+		}
+	}
+
+	p.string(name)
+	if name != "" && !ast.IsExported(name) {
+		p.pkg(f.Pkg(), false)
+	}
+}
+
+func basetypeName(typ types.Type) string {
+	switch typ := deref(typ).(type) {
+	case *types.Basic:
+		return typ.Name()
+	case *types.Named:
+		return typ.Obj().Name()
+	default:
+		return "" // unnamed type
+	}
+}
+
+func (p *exporter) paramList(params *types.Tuple, variadic bool) {
+	// use negative length to indicate unnamed parameters
+	// (look at the first parameter only since either all
+	// names are present or all are absent)
+	n := params.Len()
+	if n > 0 && params.At(0).Name() == "" {
+		n = -n
+	}
+	p.int(n)
+	for i := 0; i < params.Len(); i++ {
+		q := params.At(i)
+		t := q.Type()
+		if variadic && i == params.Len()-1 {
+			t = &dddSlice{t.(*types.Slice).Elem()}
+		}
+		p.typ(t)
+		if n > 0 {
+			name := q.Name()
+			p.string(name)
+			if name != "_" {
+				p.pkg(q.Pkg(), false)
+			}
+		}
+		p.string("") // no compiler-specific info
+	}
+}
+
+func (p *exporter) value(x constant.Value) {
+	if trace {
+		p.tracef("= ")
+	}
+
+	switch x.Kind() {
+	case constant.Bool:
+		tag := falseTag
+		if constant.BoolVal(x) {
+			tag = trueTag
+		}
+		p.tag(tag)
+
+	case constant.Int:
+		if v, exact := constant.Int64Val(x); exact {
+			// common case: x fits into an int64 - use compact encoding
+			p.tag(int64Tag)
+			p.int64(v)
+			return
+		}
+		// uncommon case: large x - use float encoding
+		// (powers of 2 will be encoded efficiently with exponent)
+		p.tag(floatTag)
+		p.float(constant.ToFloat(x))
+
+	case constant.Float:
+		p.tag(floatTag)
+		p.float(x)
+
+	case constant.Complex:
+		p.tag(complexTag)
+		p.float(constant.Real(x))
+		p.float(constant.Imag(x))
+
+	case constant.String:
+		p.tag(stringTag)
+		p.string(constant.StringVal(x))
+
+	case constant.Unknown:
+		// package contains type errors
+		p.tag(unknownTag)
+
+	default:
+		panic(internalErrorf("unexpected value %v (%T)", x, x))
+	}
+}
+
+func (p *exporter) float(x constant.Value) {
+	if x.Kind() != constant.Float {
+		panic(internalErrorf("unexpected constant %v, want float", x))
+	}
+	// extract sign (there is no -0)
+	sign := constant.Sign(x)
+	if sign == 0 {
+		// x == 0
+		p.int(0)
+		return
+	}
+	// x != 0
+
+	var f big.Float
+	if v, exact := constant.Float64Val(x); exact {
+		// float64
+		f.SetFloat64(v)
+	} else if num, denom := constant.Num(x), constant.Denom(x); num.Kind() == constant.Int {
+		// TODO(gri): add big.Rat accessor to constant.Value.
+		r := valueToRat(num)
+		f.SetRat(r.Quo(r, valueToRat(denom)))
+	} else {
+		// Value too large to represent as a fraction => inaccessible.
+		// TODO(gri): add big.Float accessor to constant.Value.
+		f.SetFloat64(math.MaxFloat64) // FIXME
+	}
+
+	// extract exponent such that 0.5 <= m < 1.0
+	var m big.Float
+	exp := f.MantExp(&m)
+
+	// extract mantissa as *big.Int
+	// - set exponent large enough so mant satisfies mant.IsInt()
+	// - get *big.Int from mant
+	m.SetMantExp(&m, int(m.MinPrec()))
+	mant, acc := m.Int(nil)
+	if acc != big.Exact {
+		panic(internalError("internal error"))
+	}
+
+	p.int(sign)
+	p.int(exp)
+	p.string(string(mant.Bytes()))
+}
+
+func valueToRat(x constant.Value) *big.Rat {
+	// Convert little-endian to big-endian.
+	// I can't believe this is necessary.
+	bytes := constant.Bytes(x)
+	for i := 0; i < len(bytes)/2; i++ {
+		bytes[i], bytes[len(bytes)-1-i] = bytes[len(bytes)-1-i], bytes[i]
+	}
+	return new(big.Rat).SetInt(new(big.Int).SetBytes(bytes))
+}
+
+func (p *exporter) bool(b bool) bool {
+	if trace {
+		p.tracef("[")
+		defer p.tracef("= %v] ", b)
+	}
+
+	x := 0
+	if b {
+		x = 1
+	}
+	p.int(x)
+	return b
+}
+
+// ----------------------------------------------------------------------------
+// Low-level encoders
+
+func (p *exporter) index(marker byte, index int) {
+	if index < 0 {
+		panic(internalError("invalid index < 0"))
+	}
+	if debugFormat {
+		p.marker('t')
+	}
+	if trace {
+		p.tracef("%c%d ", marker, index)
+	}
+	p.rawInt64(int64(index))
+}
+
+func (p *exporter) tag(tag int) {
+	if tag >= 0 {
+		panic(internalError("invalid tag >= 0"))
+	}
+	if debugFormat {
+		p.marker('t')
+	}
+	if trace {
+		p.tracef("%s ", tagString[-tag])
+	}
+	p.rawInt64(int64(tag))
+}
+
+func (p *exporter) int(x int) {
+	p.int64(int64(x))
+}
+
+func (p *exporter) int64(x int64) {
+	if debugFormat {
+		p.marker('i')
+	}
+	if trace {
+		p.tracef("%d ", x)
+	}
+	p.rawInt64(x)
+}
+
+func (p *exporter) string(s string) {
+	if debugFormat {
+		p.marker('s')
+	}
+	if trace {
+		p.tracef("%q ", s)
+	}
+	// if we saw the string before, write its index (>= 0)
+	// (the empty string is mapped to 0)
+	if i, ok := p.strIndex[s]; ok {
+		p.rawInt64(int64(i))
+		return
+	}
+	// otherwise, remember string and write its negative length and bytes
+	p.strIndex[s] = len(p.strIndex)
+	p.rawInt64(-int64(len(s)))
+	for i := 0; i < len(s); i++ {
+		p.rawByte(s[i])
+	}
+}
+
+// marker emits a marker byte and position information which makes
+// it easy for a reader to detect if it is "out of sync". Used for
+// debugFormat format only.
+func (p *exporter) marker(m byte) {
+	p.rawByte(m)
+	// Enable this for help tracking down the location
+	// of an incorrect marker when running in debugFormat.
+	if false && trace {
+		p.tracef("#%d ", p.written)
+	}
+	p.rawInt64(int64(p.written))
+}
+
+// rawInt64 should only be used by low-level encoders.
+func (p *exporter) rawInt64(x int64) {
+	var tmp [binary.MaxVarintLen64]byte
+	n := binary.PutVarint(tmp[:], x)
+	for i := 0; i < n; i++ {
+		p.rawByte(tmp[i])
+	}
+}
+
+// rawStringln should only be used to emit the initial version string.
+func (p *exporter) rawStringln(s string) {
+	for i := 0; i < len(s); i++ {
+		p.rawByte(s[i])
+	}
+	p.rawByte('\n')
+}
+
+// rawByte is the bottleneck interface to write to p.out.
+// rawByte escapes b as follows (any encoding does that
+// hides '$'):
+//
+//	'$'  => '|' 'S'
+//	'|'  => '|' '|'
+//
+// Necessary so other tools can find the end of the
+// export data by searching for "$$".
+// rawByte should only be used by low-level encoders.
+func (p *exporter) rawByte(b byte) {
+	switch b {
+	case '$':
+		// write '$' as '|' 'S'
+		b = 'S'
+		fallthrough
+	case '|':
+		// write '|' as '|' '|'
+		p.out.WriteByte('|')
+		p.written++
+	}
+	p.out.WriteByte(b)
+	p.written++
+}
+
+// tracef is like fmt.Printf but it rewrites the format string
+// to take care of indentation.
+func (p *exporter) tracef(format string, args ...interface{}) {
+	if strings.ContainsAny(format, "<>\n") {
+		var buf bytes.Buffer
+		for i := 0; i < len(format); i++ {
+			// no need to deal with runes
+			ch := format[i]
+			switch ch {
+			case '>':
+				p.indent++
+				continue
+			case '<':
+				p.indent--
+				continue
+			}
+			buf.WriteByte(ch)
+			if ch == '\n' {
+				for j := p.indent; j > 0; j-- {
+					buf.WriteString(".  ")
+				}
+			}
+		}
+		format = buf.String()
+	}
+	fmt.Printf(format, args...)
+}
+
+// Debugging support.
+// (tagString is only used when tracing is enabled)
+var tagString = [...]string{
+	// Packages
+	-packageTag: "package",
+
+	// Types
+	-namedTag:     "named type",
+	-arrayTag:     "array",
+	-sliceTag:     "slice",
+	-dddTag:       "ddd",
+	-structTag:    "struct",
+	-pointerTag:   "pointer",
+	-signatureTag: "signature",
+	-interfaceTag: "interface",
+	-mapTag:       "map",
+	-chanTag:      "chan",
+
+	// Values
+	-falseTag:    "false",
+	-trueTag:     "true",
+	-int64Tag:    "int64",
+	-floatTag:    "float",
+	-fractionTag: "fraction",
+	-complexTag:  "complex",
+	-stringTag:   "string",
+	-unknownTag:  "unknown",
+
+	// Type aliases
+	-aliasTag: "alias",
+}

vendor/golang.org/x/tools/go/internal/gcimporter/exportdata.go

@@ -0,0 +1,93 @@
+// Copyright 2011 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.
+
+// This file is a copy of $GOROOT/src/go/internal/gcimporter/exportdata.go.
+
+// This file implements FindExportData.
+
+package gcimporter
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"strconv"
+	"strings"
+)
+
+func readGopackHeader(r *bufio.Reader) (name string, size int, err error) {
+	// See $GOROOT/include/ar.h.
+	hdr := make([]byte, 16+12+6+6+8+10+2)
+	_, err = io.ReadFull(r, hdr)
+	if err != nil {
+		return
+	}
+	// leave for debugging
+	if false {
+		fmt.Printf("header: %s", hdr)
+	}
+	s := strings.TrimSpace(string(hdr[16+12+6+6+8:][:10]))
+	size, err = strconv.Atoi(s)
+	if err != nil || hdr[len(hdr)-2] != '`' || hdr[len(hdr)-1] != '\n' {
+		err = fmt.Errorf("invalid archive header")
+		return
+	}
+	name = strings.TrimSpace(string(hdr[:16]))
+	return
+}
+
+// FindExportData positions the reader r at the beginning of the
+// export data section of an underlying GC-created object/archive
+// file by reading from it. The reader must be positioned at the
+// start of the file before calling this function. The hdr result
+// is the string before the export data, either "$$" or "$$B".
+//
+func FindExportData(r *bufio.Reader) (hdr string, err error) {
+	// Read first line to make sure this is an object file.
+	line, err := r.ReadSlice('\n')
+	if err != nil {
+		err = fmt.Errorf("can't find export data (%v)", err)
+		return
+	}
+
+	if string(line) == "!<arch>\n" {
+		// Archive file. Scan to __.PKGDEF.
+		var name string
+		if name, _, err = readGopackHeader(r); err != nil {
+			return
+		}
+
+		// First entry should be __.PKGDEF.
+		if name != "__.PKGDEF" {
+			err = fmt.Errorf("go archive is missing __.PKGDEF")
+			return
+		}
+
+		// Read first line of __.PKGDEF data, so that line
+		// is once again the first line of the input.
+		if line, err = r.ReadSlice('\n'); err != nil {
+			err = fmt.Errorf("can't find export data (%v)", err)
+			return
+		}
+	}
+
+	// Now at __.PKGDEF in archive or still at beginning of file.
+	// Either way, line should begin with "go object ".
+	if !strings.HasPrefix(string(line), "go object ") {
+		err = fmt.Errorf("not a Go object file")
+		return
+	}
+
+	// Skip over object header to export data.
+	// Begins after first line starting with $$.
+	for line[0] != '$' {
+		if line, err = r.ReadSlice('\n'); err != nil {
+			err = fmt.Errorf("can't find export data (%v)", err)
+			return
+		}
+	}
+	hdr = string(line)
+
+	return
+}

vendor/golang.org/x/tools/go/internal/gcimporter/iexport.go

@@ -0,0 +1,723 @@
+// Copyright 2019 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.
+
+// Indexed binary package export.
+// This file was derived from $GOROOT/src/cmd/compile/internal/gc/iexport.go;
+// see that file for specification of the format.
+
+// +build go1.11
+
+package gcimporter
+
+import (
+	"bytes"
+	"encoding/binary"
+	"go/ast"
+	"go/constant"
+	"go/token"
+	"go/types"
+	"io"
+	"math/big"
+	"reflect"
+	"sort"
+)
+
+// Current indexed export format version. Increase with each format change.
+// 0: Go1.11 encoding
+const iexportVersion = 0
+
+// IExportData returns the binary export data for pkg.
+// If no file set is provided, position info will be missing.
+func IExportData(fset *token.FileSet, pkg *types.Package) (b []byte, err error) {
+	defer func() {
+		if e := recover(); e != nil {
+			if ierr, ok := e.(internalError); ok {
+				err = ierr
+				return
+			}
+			// Not an internal error; panic again.
+			panic(e)
+		}
+	}()
+
+	p := iexporter{
+		out:         bytes.NewBuffer(nil),
+		fset:        fset,
+		allPkgs:     map[*types.Package]bool{},
+		stringIndex: map[string]uint64{},
+		declIndex:   map[types.Object]uint64{},
+		typIndex:    map[types.Type]uint64{},
+	}
+
+	for i, pt := range predeclared() {
+		p.typIndex[pt] = uint64(i)
+	}
+	if len(p.typIndex) > predeclReserved {
+		panic(internalErrorf("too many predeclared types: %d > %d", len(p.typIndex), predeclReserved))
+	}
+
+	// Initialize work queue with exported declarations.
+	scope := pkg.Scope()
+	for _, name := range scope.Names() {
+		if ast.IsExported(name) {
+			p.pushDecl(scope.Lookup(name))
+		}
+	}
+
+	// Loop until no more work.
+	for !p.declTodo.empty() {
+		p.doDecl(p.declTodo.popHead())
+	}
+
+	// Append indices to data0 section.
+	dataLen := uint64(p.data0.Len())
+	w := p.newWriter()
+	w.writeIndex(p.declIndex, pkg)
+	w.flush()
+
+	// Assemble header.
+	var hdr intWriter
+	hdr.WriteByte('i')
+	hdr.uint64(iexportVersion)
+	hdr.uint64(uint64(p.strings.Len()))
+	hdr.uint64(dataLen)
+
+	// Flush output.
+	io.Copy(p.out, &hdr)
+	io.Copy(p.out, &p.strings)
+	io.Copy(p.out, &p.data0)
+
+	return p.out.Bytes(), nil
+}
+
+// writeIndex writes out an object index. mainIndex indicates whether
+// we're writing out the main index, which is also read by
+// non-compiler tools and includes a complete package description
+// (i.e., name and height).
+func (w *exportWriter) writeIndex(index map[types.Object]uint64, localpkg *types.Package) {
+	// Build a map from packages to objects from that package.
+	pkgObjs := map[*types.Package][]types.Object{}
+
+	// For the main index, make sure to include every package that
+	// we reference, even if we're not exporting (or reexporting)
+	// any symbols from it.
+	pkgObjs[localpkg] = nil
+	for pkg := range w.p.allPkgs {
+		pkgObjs[pkg] = nil
+	}
+
+	for obj := range index {
+		pkgObjs[obj.Pkg()] = append(pkgObjs[obj.Pkg()], obj)
+	}
+
+	var pkgs []*types.Package
+	for pkg, objs := range pkgObjs {
+		pkgs = append(pkgs, pkg)
+
+		sort.Slice(objs, func(i, j int) bool {
+			return objs[i].Name() < objs[j].Name()
+		})
+	}
+
+	sort.Slice(pkgs, func(i, j int) bool {
+		return pkgs[i].Path() < pkgs[j].Path()
+	})
+
+	w.uint64(uint64(len(pkgs)))
+	for _, pkg := range pkgs {
+		w.string(pkg.Path())
+		w.string(pkg.Name())
+		w.uint64(uint64(0)) // package height is not needed for go/types
+
+		objs := pkgObjs[pkg]
+		w.uint64(uint64(len(objs)))
+		for _, obj := range objs {
+			w.string(obj.Name())
+			w.uint64(index[obj])
+		}
+	}
+}
+
+type iexporter struct {
+	fset *token.FileSet
+	out  *bytes.Buffer
+
+	// allPkgs tracks all packages that have been referenced by
+	// the export data, so we can ensure to include them in the
+	// main index.
+	allPkgs map[*types.Package]bool
+
+	declTodo objQueue
+
+	strings     intWriter
+	stringIndex map[string]uint64
+
+	data0     intWriter
+	declIndex map[types.Object]uint64
+	typIndex  map[types.Type]uint64
+}
+
+// stringOff returns the offset of s within the string section.
+// If not already present, it's added to the end.
+func (p *iexporter) stringOff(s string) uint64 {
+	off, ok := p.stringIndex[s]
+	if !ok {
+		off = uint64(p.strings.Len())
+		p.stringIndex[s] = off
+
+		p.strings.uint64(uint64(len(s)))
+		p.strings.WriteString(s)
+	}
+	return off
+}
+
+// pushDecl adds n to the declaration work queue, if not already present.
+func (p *iexporter) pushDecl(obj types.Object) {
+	// Package unsafe is known to the compiler and predeclared.
+	assert(obj.Pkg() != types.Unsafe)
+
+	if _, ok := p.declIndex[obj]; ok {
+		return
+	}
+
+	p.declIndex[obj] = ^uint64(0) // mark n present in work queue
+	p.declTodo.pushTail(obj)
+}
+
+// exportWriter handles writing out individual data section chunks.
+type exportWriter struct {
+	p *iexporter
+
+	data     intWriter
+	currPkg  *types.Package
+	prevFile string
+	prevLine int64
+}
+
+func (p *iexporter) doDecl(obj types.Object) {
+	w := p.newWriter()
+	w.setPkg(obj.Pkg(), false)
+
+	switch obj := obj.(type) {
+	case *types.Var:
+		w.tag('V')
+		w.pos(obj.Pos())
+		w.typ(obj.Type(), obj.Pkg())
+
+	case *types.Func:
+		sig, _ := obj.Type().(*types.Signature)
+		if sig.Recv() != nil {
+			panic(internalErrorf("unexpected method: %v", sig))
+		}
+		w.tag('F')
+		w.pos(obj.Pos())
+		w.signature(sig)
+
+	case *types.Const:
+		w.tag('C')
+		w.pos(obj.Pos())
+		w.value(obj.Type(), obj.Val())
+
+	case *types.TypeName:
+		if obj.IsAlias() {
+			w.tag('A')
+			w.pos(obj.Pos())
+			w.typ(obj.Type(), obj.Pkg())
+			break
+		}
+
+		// Defined type.
+		w.tag('T')
+		w.pos(obj.Pos())
+
+		underlying := obj.Type().Underlying()
+		w.typ(underlying, obj.Pkg())
+
+		t := obj.Type()
+		if types.IsInterface(t) {
+			break
+		}
+
+		named, ok := t.(*types.Named)
+		if !ok {
+			panic(internalErrorf("%s is not a defined type", t))
+		}
+
+		n := named.NumMethods()
+		w.uint64(uint64(n))
+		for i := 0; i < n; i++ {
+			m := named.Method(i)
+			w.pos(m.Pos())
+			w.string(m.Name())
+			sig, _ := m.Type().(*types.Signature)
+			w.param(sig.Recv())
+			w.signature(sig)
+		}
+
+	default:
+		panic(internalErrorf("unexpected object: %v", obj))
+	}
+
+	p.declIndex[obj] = w.flush()
+}
+
+func (w *exportWriter) tag(tag byte) {
+	w.data.WriteByte(tag)
+}
+
+func (w *exportWriter) pos(pos token.Pos) {
+	p := w.p.fset.Position(pos)
+	file := p.Filename
+	line := int64(p.Line)
+
+	// When file is the same as the last position (common case),
+	// we can save a few bytes by delta encoding just the line
+	// number.
+	//
+	// Note: Because data objects may be read out of order (or not
+	// at all), we can only apply delta encoding within a single
+	// object. This is handled implicitly by tracking prevFile and
+	// prevLine as fields of exportWriter.
+
+	if file == w.prevFile {
+		delta := line - w.prevLine
+		w.int64(delta)
+		if delta == deltaNewFile {
+			w.int64(-1)
+		}
+	} else {
+		w.int64(deltaNewFile)
+		w.int64(line) // line >= 0
+		w.string(file)
+		w.prevFile = file
+	}
+	w.prevLine = line
+}
+
+func (w *exportWriter) pkg(pkg *types.Package) {
+	// Ensure any referenced packages are declared in the main index.
+	w.p.allPkgs[pkg] = true
+
+	w.string(pkg.Path())
+}
+
+func (w *exportWriter) qualifiedIdent(obj types.Object) {
+	// Ensure any referenced declarations are written out too.
+	w.p.pushDecl(obj)
+
+	w.string(obj.Name())
+	w.pkg(obj.Pkg())
+}
+
+func (w *exportWriter) typ(t types.Type, pkg *types.Package) {
+	w.data.uint64(w.p.typOff(t, pkg))
+}
+
+func (p *iexporter) newWriter() *exportWriter {
+	return &exportWriter{p: p}
+}
+
+func (w *exportWriter) flush() uint64 {
+	off := uint64(w.p.data0.Len())
+	io.Copy(&w.p.data0, &w.data)
+	return off
+}
+
+func (p *iexporter) typOff(t types.Type, pkg *types.Package) uint64 {
+	off, ok := p.typIndex[t]
+	if !ok {
+		w := p.newWriter()
+		w.doTyp(t, pkg)
+		off = predeclReserved + w.flush()
+		p.typIndex[t] = off
+	}
+	return off
+}
+
+func (w *exportWriter) startType(k itag) {
+	w.data.uint64(uint64(k))
+}
+
+func (w *exportWriter) doTyp(t types.Type, pkg *types.Package) {
+	switch t := t.(type) {
+	case *types.Named:
+		w.startType(definedType)
+		w.qualifiedIdent(t.Obj())
+
+	case *types.Pointer:
+		w.startType(pointerType)
+		w.typ(t.Elem(), pkg)
+
+	case *types.Slice:
+		w.startType(sliceType)
+		w.typ(t.Elem(), pkg)
+
+	case *types.Array:
+		w.startType(arrayType)
+		w.uint64(uint64(t.Len()))
+		w.typ(t.Elem(), pkg)
+
+	case *types.Chan:
+		w.startType(chanType)
+		// 1 RecvOnly; 2 SendOnly; 3 SendRecv
+		var dir uint64
+		switch t.Dir() {
+		case types.RecvOnly:
+			dir = 1
+		case types.SendOnly:
+			dir = 2
+		case types.SendRecv:
+			dir = 3
+		}
+		w.uint64(dir)
+		w.typ(t.Elem(), pkg)
+
+	case *types.Map:
+		w.startType(mapType)
+		w.typ(t.Key(), pkg)
+		w.typ(t.Elem(), pkg)
+
+	case *types.Signature:
+		w.startType(signatureType)
+		w.setPkg(pkg, true)
+		w.signature(t)
+
+	case *types.Struct:
+		w.startType(structType)
+		w.setPkg(pkg, true)
+
+		n := t.NumFields()
+		w.uint64(uint64(n))
+		for i := 0; i < n; i++ {
+			f := t.Field(i)
+			w.pos(f.Pos())
+			w.string(f.Name())
+			w.typ(f.Type(), pkg)
+			w.bool(f.Embedded())
+			w.string(t.Tag(i)) // note (or tag)
+		}
+
+	case *types.Interface:
+		w.startType(interfaceType)
+		w.setPkg(pkg, true)
+
+		n := t.NumEmbeddeds()
+		w.uint64(uint64(n))
+		for i := 0; i < n; i++ {
+			f := t.Embedded(i)
+			w.pos(f.Obj().Pos())
+			w.typ(f.Obj().Type(), f.Obj().Pkg())
+		}
+
+		n = t.NumExplicitMethods()
+		w.uint64(uint64(n))
+		for i := 0; i < n; i++ {
+			m := t.ExplicitMethod(i)
+			w.pos(m.Pos())
+			w.string(m.Name())
+			sig, _ := m.Type().(*types.Signature)
+			w.signature(sig)
+		}
+
+	default:
+		panic(internalErrorf("unexpected type: %v, %v", t, reflect.TypeOf(t)))
+	}
+}
+
+func (w *exportWriter) setPkg(pkg *types.Package, write bool) {
+	if write {
+		w.pkg(pkg)
+	}
+
+	w.currPkg = pkg
+}
+
+func (w *exportWriter) signature(sig *types.Signature) {
+	w.paramList(sig.Params())
+	w.paramList(sig.Results())
+	if sig.Params().Len() > 0 {
+		w.bool(sig.Variadic())
+	}
+}
+
+func (w *exportWriter) paramList(tup *types.Tuple) {
+	n := tup.Len()
+	w.uint64(uint64(n))
+	for i := 0; i < n; i++ {
+		w.param(tup.At(i))
+	}
+}
+
+func (w *exportWriter) param(obj types.Object) {
+	w.pos(obj.Pos())
+	w.localIdent(obj)
+	w.typ(obj.Type(), obj.Pkg())
+}
+
+func (w *exportWriter) value(typ types.Type, v constant.Value) {
+	w.typ(typ, nil)
+
+	switch v.Kind() {
+	case constant.Bool:
+		w.bool(constant.BoolVal(v))
+	case constant.Int:
+		var i big.Int
+		if i64, exact := constant.Int64Val(v); exact {
+			i.SetInt64(i64)
+		} else if ui64, exact := constant.Uint64Val(v); exact {
+			i.SetUint64(ui64)
+		} else {
+			i.SetString(v.ExactString(), 10)
+		}
+		w.mpint(&i, typ)
+	case constant.Float:
+		f := constantToFloat(v)
+		w.mpfloat(f, typ)
+	case constant.Complex:
+		w.mpfloat(constantToFloat(constant.Real(v)), typ)
+		w.mpfloat(constantToFloat(constant.Imag(v)), typ)
+	case constant.String:
+		w.string(constant.StringVal(v))
+	case constant.Unknown:
+		// package contains type errors
+	default:
+		panic(internalErrorf("unexpected value %v (%T)", v, v))
+	}
+}
+
+// constantToFloat converts a constant.Value with kind constant.Float to a
+// big.Float.
+func constantToFloat(x constant.Value) *big.Float {
+	assert(x.Kind() == constant.Float)
+	// Use the same floating-point precision (512) as cmd/compile
+	// (see Mpprec in cmd/compile/internal/gc/mpfloat.go).
+	const mpprec = 512
+	var f big.Float
+	f.SetPrec(mpprec)
+	if v, exact := constant.Float64Val(x); exact {
+		// float64
+		f.SetFloat64(v)
+	} else if num, denom := constant.Num(x), constant.Denom(x); num.Kind() == constant.Int {
+		// TODO(gri): add big.Rat accessor to constant.Value.
+		n := valueToRat(num)
+		d := valueToRat(denom)
+		f.SetRat(n.Quo(n, d))
+	} else {
+		// Value too large to represent as a fraction => inaccessible.
+		// TODO(gri): add big.Float accessor to constant.Value.
+		_, ok := f.SetString(x.ExactString())
+		assert(ok)
+	}
+	return &f
+}
+
+// mpint exports a multi-precision integer.
+//
+// For unsigned types, small values are written out as a single
+// byte. Larger values are written out as a length-prefixed big-endian
+// byte string, where the length prefix is encoded as its complement.
+// For example, bytes 0, 1, and 2 directly represent the integer
+// values 0, 1, and 2; while bytes 255, 254, and 253 indicate a 1-,
+// 2-, and 3-byte big-endian string follow.
+//
+// Encoding for signed types use the same general approach as for
+// unsigned types, except small values use zig-zag encoding and the
+// bottom bit of length prefix byte for large values is reserved as a
+// sign bit.
+//
+// The exact boundary between small and large encodings varies
+// according to the maximum number of bytes needed to encode a value
+// of type typ. As a special case, 8-bit types are always encoded as a
+// single byte.
+//
+// TODO(mdempsky): Is this level of complexity really worthwhile?
+func (w *exportWriter) mpint(x *big.Int, typ types.Type) {
+	basic, ok := typ.Underlying().(*types.Basic)
+	if !ok {
+		panic(internalErrorf("unexpected type %v (%T)", typ.Underlying(), typ.Underlying()))
+	}
+
+	signed, maxBytes := intSize(basic)
+
+	negative := x.Sign() < 0
+	if !signed && negative {
+		panic(internalErrorf("negative unsigned integer; type %v, value %v", typ, x))
+	}
+
+	b := x.Bytes()
+	if len(b) > 0 && b[0] == 0 {
+		panic(internalErrorf("leading zeros"))
+	}
+	if uint(len(b)) > maxBytes {
+		panic(internalErrorf("bad mpint length: %d > %d (type %v, value %v)", len(b), maxBytes, typ, x))
+	}
+
+	maxSmall := 256 - maxBytes
+	if signed {
+		maxSmall = 256 - 2*maxBytes
+	}
+	if maxBytes == 1 {
+		maxSmall = 256
+	}
+
+	// Check if x can use small value encoding.
+	if len(b) <= 1 {
+		var ux uint
+		if len(b) == 1 {
+			ux = uint(b[0])
+		}
+		if signed {
+			ux <<= 1
+			if negative {
+				ux--
+			}
+		}
+		if ux < maxSmall {
+			w.data.WriteByte(byte(ux))
+			return
+		}
+	}
+
+	n := 256 - uint(len(b))
+	if signed {
+		n = 256 - 2*uint(len(b))
+		if negative {
+			n |= 1
+		}
+	}
+	if n < maxSmall || n >= 256 {
+		panic(internalErrorf("encoding mistake: %d, %v, %v => %d", len(b), signed, negative, n))
+	}
+
+	w.data.WriteByte(byte(n))
+	w.data.Write(b)
+}
+
+// mpfloat exports a multi-precision floating point number.
+//
+// The number's value is decomposed into mantissa × 2**exponent, where
+// mantissa is an integer. The value is written out as mantissa (as a
+// multi-precision integer) and then the exponent, except exponent is
+// omitted if mantissa is zero.
+func (w *exportWriter) mpfloat(f *big.Float, typ types.Type) {
+	if f.IsInf() {
+		panic("infinite constant")
+	}
+
+	// Break into f = mant × 2**exp, with 0.5 <= mant < 1.
+	var mant big.Float
+	exp := int64(f.MantExp(&mant))
+
+	// Scale so that mant is an integer.
+	prec := mant.MinPrec()
+	mant.SetMantExp(&mant, int(prec))
+	exp -= int64(prec)
+
+	manti, acc := mant.Int(nil)
+	if acc != big.Exact {
+		panic(internalErrorf("mantissa scaling failed for %f (%s)", f, acc))
+	}
+	w.mpint(manti, typ)
+	if manti.Sign() != 0 {
+		w.int64(exp)
+	}
+}
+
+func (w *exportWriter) bool(b bool) bool {
+	var x uint64
+	if b {
+		x = 1
+	}
+	w.uint64(x)
+	return b
+}
+
+func (w *exportWriter) int64(x int64)   { w.data.int64(x) }
+func (w *exportWriter) uint64(x uint64) { w.data.uint64(x) }
+func (w *exportWriter) string(s string) { w.uint64(w.p.stringOff(s)) }
+
+func (w *exportWriter) localIdent(obj types.Object) {
+	// Anonymous parameters.
+	if obj == nil {
+		w.string("")
+		return
+	}
+
+	name := obj.Name()
+	if name == "_" {
+		w.string("_")
+		return
+	}
+
+	w.string(name)
+}
+
+type intWriter struct {
+	bytes.Buffer
+}
+
+func (w *intWriter) int64(x int64) {
+	var buf [binary.MaxVarintLen64]byte
+	n := binary.PutVarint(buf[:], x)
+	w.Write(buf[:n])
+}
+
+func (w *intWriter) uint64(x uint64) {
+	var buf [binary.MaxVarintLen64]byte
+	n := binary.PutUvarint(buf[:], x)
+	w.Write(buf[:n])
+}
+
+func assert(cond bool) {
+	if !cond {
+		panic("internal error: assertion failed")
+	}
+}
+
+// The below is copied from go/src/cmd/compile/internal/gc/syntax.go.
+
+// objQueue is a FIFO queue of types.Object. The zero value of objQueue is
+// a ready-to-use empty queue.
+type objQueue struct {
+	ring       []types.Object
+	head, tail int
+}
+
+// empty returns true if q contains no Nodes.
+func (q *objQueue) empty() bool {
+	return q.head == q.tail
+}
+
+// pushTail appends n to the tail of the queue.
+func (q *objQueue) pushTail(obj types.Object) {
+	if len(q.ring) == 0 {
+		q.ring = make([]types.Object, 16)
+	} else if q.head+len(q.ring) == q.tail {
+		// Grow the ring.
+		nring := make([]types.Object, len(q.ring)*2)
+		// Copy the old elements.
+		part := q.ring[q.head%len(q.ring):]
+		if q.tail-q.head <= len(part) {
+			part = part[:q.tail-q.head]
+			copy(nring, part)
+		} else {
+			pos := copy(nring, part)
+			copy(nring[pos:], q.ring[:q.tail%len(q.ring)])
+		}
+		q.ring, q.head, q.tail = nring, 0, q.tail-q.head
+	}
+
+	q.ring[q.tail%len(q.ring)] = obj
+	q.tail++
+}
+
+// popHead pops a node from the head of the queue. It panics if q is empty.
+func (q *objQueue) popHead() types.Object {
+	if q.empty() {
+		panic("dequeue empty")
+	}
+	obj := q.ring[q.head%len(q.ring)]
+	q.head++
+	return obj
+}

vendor/golang.org/x/tools/go/internal/gcimporter/iimport.go

@@ -0,0 +1,606 @@
+// 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.
+
+// Indexed package import.
+// See cmd/compile/internal/gc/iexport.go for the export data format.
+
+// This file is a copy of $GOROOT/src/go/internal/gcimporter/iimport.go.
+
+package gcimporter
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"go/constant"
+	"go/token"
+	"go/types"
+	"io"
+	"sort"
+)
+
+type intReader struct {
+	*bytes.Reader
+	path string
+}
+
+func (r *intReader) int64() int64 {
+	i, err := binary.ReadVarint(r.Reader)
+	if err != nil {
+		errorf("import %q: read varint error: %v", r.path, err)
+	}
+	return i
+}
+
+func (r *intReader) uint64() uint64 {
+	i, err := binary.ReadUvarint(r.Reader)
+	if err != nil {
+		errorf("import %q: read varint error: %v", r.path, err)
+	}
+	return i
+}
+
+const predeclReserved = 32
+
+type itag uint64
+
+const (
+	// Types
+	definedType itag = iota
+	pointerType
+	sliceType
+	arrayType
+	chanType
+	mapType
+	signatureType
+	structType
+	interfaceType
+)
+
+// IImportData imports a package from the serialized package data
+// and returns the number of bytes consumed and a reference to the package.
+// If the export data version is not recognized or the format is otherwise
+// compromised, an error is returned.
+func IImportData(fset *token.FileSet, imports map[string]*types.Package, data []byte, path string) (_ int, pkg *types.Package, err error) {
+	const currentVersion = 0
+	version := -1
+	defer func() {
+		if e := recover(); e != nil {
+			if version > currentVersion {
+				err = fmt.Errorf("cannot import %q (%v), export data is newer version - update tool", path, e)
+			} else {
+				err = fmt.Errorf("cannot import %q (%v), possibly version skew - reinstall package", path, e)
+			}
+		}
+	}()
+
+	r := &intReader{bytes.NewReader(data), path}
+
+	version = int(r.uint64())
+	switch version {
+	case currentVersion:
+	default:
+		errorf("unknown iexport format version %d", version)
+	}
+
+	sLen := int64(r.uint64())
+	dLen := int64(r.uint64())
+
+	whence, _ := r.Seek(0, io.SeekCurrent)
+	stringData := data[whence : whence+sLen]
+	declData := data[whence+sLen : whence+sLen+dLen]
+	r.Seek(sLen+dLen, io.SeekCurrent)
+
+	p := iimporter{
+		ipath: path,
+
+		stringData:  stringData,
+		stringCache: make(map[uint64]string),
+		pkgCache:    make(map[uint64]*types.Package),
+
+		declData: declData,
+		pkgIndex: make(map[*types.Package]map[string]uint64),
+		typCache: make(map[uint64]types.Type),
+
+		fake: fakeFileSet{
+			fset:  fset,
+			files: make(map[string]*token.File),
+		},
+	}
+
+	for i, pt := range predeclared() {
+		p.typCache[uint64(i)] = pt
+	}
+
+	pkgList := make([]*types.Package, r.uint64())
+	for i := range pkgList {
+		pkgPathOff := r.uint64()
+		pkgPath := p.stringAt(pkgPathOff)
+		pkgName := p.stringAt(r.uint64())
+		_ = r.uint64() // package height; unused by go/types
+
+		if pkgPath == "" {
+			pkgPath = path
+		}
+		pkg := imports[pkgPath]
+		if pkg == nil {
+			pkg = types.NewPackage(pkgPath, pkgName)
+			imports[pkgPath] = pkg
+		} else if pkg.Name() != pkgName {
+			errorf("conflicting names %s and %s for package %q", pkg.Name(), pkgName, path)
+		}
+
+		p.pkgCache[pkgPathOff] = pkg
+
+		nameIndex := make(map[string]uint64)
+		for nSyms := r.uint64(); nSyms > 0; nSyms-- {
+			name := p.stringAt(r.uint64())
+			nameIndex[name] = r.uint64()
+		}
+
+		p.pkgIndex[pkg] = nameIndex
+		pkgList[i] = pkg
+	}
+	var localpkg *types.Package
+	for _, pkg := range pkgList {
+		if pkg.Path() == path {
+			localpkg = pkg
+		}
+	}
+
+	names := make([]string, 0, len(p.pkgIndex[localpkg]))
+	for name := range p.pkgIndex[localpkg] {
+		names = append(names, name)
+	}
+	sort.Strings(names)
+	for _, name := range names {
+		p.doDecl(localpkg, name)
+	}
+
+	for _, typ := range p.interfaceList {
+		typ.Complete()
+	}
+
+	// record all referenced packages as imports
+	list := append(([]*types.Package)(nil), pkgList[1:]...)
+	sort.Sort(byPath(list))
+	localpkg.SetImports(list)
+
+	// package was imported completely and without errors
+	localpkg.MarkComplete()
+
+	consumed, _ := r.Seek(0, io.SeekCurrent)
+	return int(consumed), localpkg, nil
+}
+
+type iimporter struct {
+	ipath string
+
+	stringData  []byte
+	stringCache map[uint64]string
+	pkgCache    map[uint64]*types.Package
+
+	declData []byte
+	pkgIndex map[*types.Package]map[string]uint64
+	typCache map[uint64]types.Type
+
+	fake          fakeFileSet
+	interfaceList []*types.Interface
+}
+
+func (p *iimporter) doDecl(pkg *types.Package, name string) {
+	// See if we've already imported this declaration.
+	if obj := pkg.Scope().Lookup(name); obj != nil {
+		return
+	}
+
+	off, ok := p.pkgIndex[pkg][name]
+	if !ok {
+		errorf("%v.%v not in index", pkg, name)
+	}
+
+	r := &importReader{p: p, currPkg: pkg}
+	r.declReader.Reset(p.declData[off:])
+
+	r.obj(name)
+}
+
+func (p *iimporter) stringAt(off uint64) string {
+	if s, ok := p.stringCache[off]; ok {
+		return s
+	}
+
+	slen, n := binary.Uvarint(p.stringData[off:])
+	if n <= 0 {
+		errorf("varint failed")
+	}
+	spos := off + uint64(n)
+	s := string(p.stringData[spos : spos+slen])
+	p.stringCache[off] = s
+	return s
+}
+
+func (p *iimporter) pkgAt(off uint64) *types.Package {
+	if pkg, ok := p.pkgCache[off]; ok {
+		return pkg
+	}
+	path := p.stringAt(off)
+	errorf("missing package %q in %q", path, p.ipath)
+	return nil
+}
+
+func (p *iimporter) typAt(off uint64, base *types.Named) types.Type {
+	if t, ok := p.typCache[off]; ok && (base == nil || !isInterface(t)) {
+		return t
+	}
+
+	if off < predeclReserved {
+		errorf("predeclared type missing from cache: %v", off)
+	}
+
+	r := &importReader{p: p}
+	r.declReader.Reset(p.declData[off-predeclReserved:])
+	t := r.doType(base)
+
+	if base == nil || !isInterface(t) {
+		p.typCache[off] = t
+	}
+	return t
+}
+
+type importReader struct {
+	p          *iimporter
+	declReader bytes.Reader
+	currPkg    *types.Package
+	prevFile   string
+	prevLine   int64
+}
+
+func (r *importReader) obj(name string) {
+	tag := r.byte()
+	pos := r.pos()
+
+	switch tag {
+	case 'A':
+		typ := r.typ()
+
+		r.declare(types.NewTypeName(pos, r.currPkg, name, typ))
+
+	case 'C':
+		typ, val := r.value()
+
+		r.declare(types.NewConst(pos, r.currPkg, name, typ, val))
+
+	case 'F':
+		sig := r.signature(nil)
+
+		r.declare(types.NewFunc(pos, r.currPkg, name, sig))
+
+	case 'T':
+		// Types can be recursive. We need to setup a stub
+		// declaration before recursing.
+		obj := types.NewTypeName(pos, r.currPkg, name, nil)
+		named := types.NewNamed(obj, nil, nil)
+		r.declare(obj)
+
+		underlying := r.p.typAt(r.uint64(), named).Underlying()
+		named.SetUnderlying(underlying)
+
+		if !isInterface(underlying) {
+			for n := r.uint64(); n > 0; n-- {
+				mpos := r.pos()
+				mname := r.ident()
+				recv := r.param()
+				msig := r.signature(recv)
+
+				named.AddMethod(types.NewFunc(mpos, r.currPkg, mname, msig))
+			}
+		}
+
+	case 'V':
+		typ := r.typ()
+
+		r.declare(types.NewVar(pos, r.currPkg, name, typ))
+
+	default:
+		errorf("unexpected tag: %v", tag)
+	}
+}
+
+func (r *importReader) declare(obj types.Object) {
+	obj.Pkg().Scope().Insert(obj)
+}
+
+func (r *importReader) value() (typ types.Type, val constant.Value) {
+	typ = r.typ()
+
+	switch b := typ.Underlying().(*types.Basic); b.Info() & types.IsConstType {
+	case types.IsBoolean:
+		val = constant.MakeBool(r.bool())
+
+	case types.IsString:
+		val = constant.MakeString(r.string())
+
+	case types.IsInteger:
+		val = r.mpint(b)
+
+	case types.IsFloat:
+		val = r.mpfloat(b)
+
+	case types.IsComplex:
+		re := r.mpfloat(b)
+		im := r.mpfloat(b)
+		val = constant.BinaryOp(re, token.ADD, constant.MakeImag(im))
+
+	default:
+		if b.Kind() == types.Invalid {
+			val = constant.MakeUnknown()
+			return
+		}
+		errorf("unexpected type %v", typ) // panics
+		panic("unreachable")
+	}
+
+	return
+}
+
+func intSize(b *types.Basic) (signed bool, maxBytes uint) {
+	if (b.Info() & types.IsUntyped) != 0 {
+		return true, 64
+	}
+
+	switch b.Kind() {
+	case types.Float32, types.Complex64:
+		return true, 3
+	case types.Float64, types.Complex128:
+		return true, 7
+	}
+
+	signed = (b.Info() & types.IsUnsigned) == 0
+	switch b.Kind() {
+	case types.Int8, types.Uint8:
+		maxBytes = 1
+	case types.Int16, types.Uint16:
+		maxBytes = 2
+	case types.Int32, types.Uint32:
+		maxBytes = 4
+	default:
+		maxBytes = 8
+	}
+
+	return
+}
+
+func (r *importReader) mpint(b *types.Basic) constant.Value {
+	signed, maxBytes := intSize(b)
+
+	maxSmall := 256 - maxBytes
+	if signed {
+		maxSmall = 256 - 2*maxBytes
+	}
+	if maxBytes == 1 {
+		maxSmall = 256
+	}
+
+	n, _ := r.declReader.ReadByte()
+	if uint(n) < maxSmall {
+		v := int64(n)
+		if signed {
+			v >>= 1
+			if n&1 != 0 {
+				v = ^v
+			}
+		}
+		return constant.MakeInt64(v)
+	}
+
+	v := -n
+	if signed {
+		v = -(n &^ 1) >> 1
+	}
+	if v < 1 || uint(v) > maxBytes {
+		errorf("weird decoding: %v, %v => %v", n, signed, v)
+	}
+
+	buf := make([]byte, v)
+	io.ReadFull(&r.declReader, buf)
+
+	// convert to little endian
+	// TODO(gri) go/constant should have a more direct conversion function
+	//           (e.g., once it supports a big.Float based implementation)
+	for i, j := 0, len(buf)-1; i < j; i, j = i+1, j-1 {
+		buf[i], buf[j] = buf[j], buf[i]
+	}
+
+	x := constant.MakeFromBytes(buf)
+	if signed && n&1 != 0 {
+		x = constant.UnaryOp(token.SUB, x, 0)
+	}
+	return x
+}
+
+func (r *importReader) mpfloat(b *types.Basic) constant.Value {
+	x := r.mpint(b)
+	if constant.Sign(x) == 0 {
+		return x
+	}
+
+	exp := r.int64()
+	switch {
+	case exp > 0:
+		x = constant.Shift(x, token.SHL, uint(exp))
+	case exp < 0:
+		d := constant.Shift(constant.MakeInt64(1), token.SHL, uint(-exp))
+		x = constant.BinaryOp(x, token.QUO, d)
+	}
+	return x
+}
+
+func (r *importReader) ident() string {
+	return r.string()
+}
+
+func (r *importReader) qualifiedIdent() (*types.Package, string) {
+	name := r.string()
+	pkg := r.pkg()
+	return pkg, name
+}
+
+func (r *importReader) pos() token.Pos {
+	delta := r.int64()
+	if delta != deltaNewFile {
+		r.prevLine += delta
+	} else if l := r.int64(); l == -1 {
+		r.prevLine += deltaNewFile
+	} else {
+		r.prevFile = r.string()
+		r.prevLine = l
+	}
+
+	if r.prevFile == "" && r.prevLine == 0 {
+		return token.NoPos
+	}
+
+	return r.p.fake.pos(r.prevFile, int(r.prevLine))
+}
+
+func (r *importReader) typ() types.Type {
+	return r.p.typAt(r.uint64(), nil)
+}
+
+func isInterface(t types.Type) bool {
+	_, ok := t.(*types.Interface)
+	return ok
+}
+
+func (r *importReader) pkg() *types.Package { return r.p.pkgAt(r.uint64()) }
+func (r *importReader) string() string      { return r.p.stringAt(r.uint64()) }
+
+func (r *importReader) doType(base *types.Named) types.Type {
+	switch k := r.kind(); k {
+	default:
+		errorf("unexpected kind tag in %q: %v", r.p.ipath, k)
+		return nil
+
+	case definedType:
+		pkg, name := r.qualifiedIdent()
+		r.p.doDecl(pkg, name)
+		return pkg.Scope().Lookup(name).(*types.TypeName).Type()
+	case pointerType:
+		return types.NewPointer(r.typ())
+	case sliceType:
+		return types.NewSlice(r.typ())
+	case arrayType:
+		n := r.uint64()
+		return types.NewArray(r.typ(), int64(n))
+	case chanType:
+		dir := chanDir(int(r.uint64()))
+		return types.NewChan(dir, r.typ())
+	case mapType:
+		return types.NewMap(r.typ(), r.typ())
+	case signatureType:
+		r.currPkg = r.pkg()
+		return r.signature(nil)
+
+	case structType:
+		r.currPkg = r.pkg()
+
+		fields := make([]*types.Var, r.uint64())
+		tags := make([]string, len(fields))
+		for i := range fields {
+			fpos := r.pos()
+			fname := r.ident()
+			ftyp := r.typ()
+			emb := r.bool()
+			tag := r.string()
+
+			fields[i] = types.NewField(fpos, r.currPkg, fname, ftyp, emb)
+			tags[i] = tag
+		}
+		return types.NewStruct(fields, tags)
+
+	case interfaceType:
+		r.currPkg = r.pkg()
+
+		embeddeds := make([]types.Type, r.uint64())
+		for i := range embeddeds {
+			_ = r.pos()
+			embeddeds[i] = r.typ()
+		}
+
+		methods := make([]*types.Func, r.uint64())
+		for i := range methods {
+			mpos := r.pos()
+			mname := r.ident()
+
+			// TODO(mdempsky): Matches bimport.go, but I
+			// don't agree with this.
+			var recv *types.Var
+			if base != nil {
+				recv = types.NewVar(token.NoPos, r.currPkg, "", base)
+			}
+
+			msig := r.signature(recv)
+			methods[i] = types.NewFunc(mpos, r.currPkg, mname, msig)
+		}
+
+		typ := newInterface(methods, embeddeds)
+		r.p.interfaceList = append(r.p.interfaceList, typ)
+		return typ
+	}
+}
+
+func (r *importReader) kind() itag {
+	return itag(r.uint64())
+}
+
+func (r *importReader) signature(recv *types.Var) *types.Signature {
+	params := r.paramList()
+	results := r.paramList()
+	variadic := params.Len() > 0 && r.bool()
+	return types.NewSignature(recv, params, results, variadic)
+}
+
+func (r *importReader) paramList() *types.Tuple {
+	xs := make([]*types.Var, r.uint64())
+	for i := range xs {
+		xs[i] = r.param()
+	}
+	return types.NewTuple(xs...)
+}
+
+func (r *importReader) param() *types.Var {
+	pos := r.pos()
+	name := r.ident()
+	typ := r.typ()
+	return types.NewParam(pos, r.currPkg, name, typ)
+}
+
+func (r *importReader) bool() bool {
+	return r.uint64() != 0
+}
+
+func (r *importReader) int64() int64 {
+	n, err := binary.ReadVarint(&r.declReader)
+	if err != nil {
+		errorf("readVarint: %v", err)
+	}
+	return n
+}
+
+func (r *importReader) uint64() uint64 {
+	n, err := binary.ReadUvarint(&r.declReader)
+	if err != nil {
+		errorf("readUvarint: %v", err)
+	}
+	return n
+}
+
+func (r *importReader) byte() byte {
+	x, err := r.declReader.ReadByte()
+	if err != nil {
+		errorf("declReader.ReadByte: %v", err)
+	}
+	return x
+}

vendor/golang.org/x/tools/go/internal/gcimporter/newInterface10.go

@@ -0,0 +1,21 @@
+// 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.
+
+// +build !go1.11
+
+package gcimporter
+
+import "go/types"
+
+func newInterface(methods []*types.Func, embeddeds []types.Type) *types.Interface {
+	named := make([]*types.Named, len(embeddeds))
+	for i, e := range embeddeds {
+		var ok bool
+		named[i], ok = e.(*types.Named)
+		if !ok {
+			panic("embedding of non-defined interfaces in interfaces is not supported before Go 1.11")
+		}
+	}
+	return types.NewInterface(methods, named)
+}

vendor/golang.org/x/tools/go/internal/gcimporter/newInterface11.go

@@ -0,0 +1,13 @@
+// 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.
+
+// +build go1.11
+
+package gcimporter
+
+import "go/types"
+
+func newInterface(methods []*types.Func, embeddeds []types.Type) *types.Interface {
+	return types.NewInterfaceType(methods, embeddeds)
+}

vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go

@@ -0,0 +1,160 @@
+// 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 packagesdriver fetches type sizes for go/packages and go/analysis.
+package packagesdriver
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"go/types"
+	"log"
+	"os"
+	"os/exec"
+	"strings"
+	"time"
+)
+
+var debug = false
+
+// GetSizes returns the sizes used by the underlying driver with the given parameters.
+func GetSizes(ctx context.Context, buildFlags, env []string, dir string, usesExportData bool) (types.Sizes, error) {
+	// TODO(matloob): Clean this up. This code is mostly a copy of packages.findExternalDriver.
+	const toolPrefix = "GOPACKAGESDRIVER="
+	tool := ""
+	for _, env := range env {
+		if val := strings.TrimPrefix(env, toolPrefix); val != env {
+			tool = val
+		}
+	}
+
+	if tool == "" {
+		var err error
+		tool, err = exec.LookPath("gopackagesdriver")
+		if err != nil {
+			// We did not find the driver, so use "go list".
+			tool = "off"
+		}
+	}
+
+	if tool == "off" {
+		return GetSizesGolist(ctx, buildFlags, env, dir, usesExportData)
+	}
+
+	req, err := json.Marshal(struct {
+		Command    string   `json:"command"`
+		Env        []string `json:"env"`
+		BuildFlags []string `json:"build_flags"`
+	}{
+		Command:    "sizes",
+		Env:        env,
+		BuildFlags: buildFlags,
+	})
+	if err != nil {
+		return nil, fmt.Errorf("failed to encode message to driver tool: %v", err)
+	}
+
+	buf := new(bytes.Buffer)
+	cmd := exec.CommandContext(ctx, tool)
+	cmd.Dir = dir
+	cmd.Env = env
+	cmd.Stdin = bytes.NewReader(req)
+	cmd.Stdout = buf
+	cmd.Stderr = new(bytes.Buffer)
+	if err := cmd.Run(); err != nil {
+		return nil, fmt.Errorf("%v: %v: %s", tool, err, cmd.Stderr)
+	}
+	var response struct {
+		// Sizes, if not nil, is the types.Sizes to use when type checking.
+		Sizes *types.StdSizes
+	}
+	if err := json.Unmarshal(buf.Bytes(), &response); err != nil {
+		return nil, err
+	}
+	return response.Sizes, nil
+}
+
+func GetSizesGolist(ctx context.Context, buildFlags, env []string, dir string, usesExportData bool) (types.Sizes, error) {
+	args := []string{"list", "-f", "{{context.GOARCH}} {{context.Compiler}}"}
+	args = append(args, buildFlags...)
+	args = append(args, "--", "unsafe")
+	stdout, err := InvokeGo(ctx, env, dir, usesExportData, args...)
+	if err != nil {
+		return nil, err
+	}
+	fields := strings.Fields(stdout.String())
+	if len(fields) < 2 {
+		return nil, fmt.Errorf("could not determine GOARCH and Go compiler")
+	}
+	goarch := fields[0]
+	compiler := fields[1]
+	return types.SizesFor(compiler, goarch), nil
+}
+
+// InvokeGo returns the stdout of a go command invocation.
+func InvokeGo(ctx context.Context, env []string, dir string, usesExportData bool, args ...string) (*bytes.Buffer, error) {
+	if debug {
+		defer func(start time.Time) { log.Printf("%s for %v", time.Since(start), cmdDebugStr(env, args...)) }(time.Now())
+	}
+	stdout := new(bytes.Buffer)
+	stderr := new(bytes.Buffer)
+	cmd := exec.CommandContext(ctx, "go", args...)
+	// On darwin the cwd gets resolved to the real path, which breaks anything that
+	// expects the working directory to keep the original path, including the
+	// go command when dealing with modules.
+	// The Go stdlib has a special feature where if the cwd and the PWD are the
+	// same node then it trusts the PWD, so by setting it in the env for the child
+	// process we fix up all the paths returned by the go command.
+	cmd.Env = append(append([]string{}, env...), "PWD="+dir)
+	cmd.Dir = dir
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	if err := cmd.Run(); err != nil {
+		exitErr, ok := err.(*exec.ExitError)
+		if !ok {
+			// Catastrophic error:
+			// - executable not found
+			// - context cancellation
+			return nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err)
+		}
+
+		// Export mode entails a build.
+		// If that build fails, errors appear on stderr
+		// (despite the -e flag) and the Export field is blank.
+		// Do not fail in that case.
+		if !usesExportData {
+			return nil, fmt.Errorf("go %v: %s: %s", args, exitErr, stderr)
+		}
+	}
+
+	// As of writing, go list -export prints some non-fatal compilation
+	// errors to stderr, even with -e set. We would prefer that it put
+	// them in the Package.Error JSON (see https://golang.org/issue/26319).
+	// In the meantime, there's nowhere good to put them, but they can
+	// be useful for debugging. Print them if $GOPACKAGESPRINTGOLISTERRORS
+	// is set.
+	if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTGOLISTERRORS") != "" {
+		fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(env, args...), stderr)
+	}
+
+	// debugging
+	if false {
+		fmt.Fprintf(os.Stderr, "%s stdout: <<%s>>\n", cmdDebugStr(env, args...), stdout)
+	}
+
+	return stdout, nil
+}
+
+func cmdDebugStr(envlist []string, args ...string) string {
+	env := make(map[string]string)
+	for _, kv := range envlist {
+		split := strings.Split(kv, "=")
+		k, v := split[0], split[1]
+		env[k] = v
+	}
+
+	return fmt.Sprintf("GOROOT=%v GOPATH=%v GO111MODULE=%v PWD=%v go %v", env["GOROOT"], env["GOPATH"], env["GO111MODULE"], env["PWD"], args)
+}

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

@@ -0,0 +1,222 @@
+// 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 packages loads Go packages for inspection and analysis.
+
+The Load function takes as input a list of patterns and return a list of Package
+structs describing individual packages matched by those patterns.
+The LoadMode controls the amount of detail in the loaded packages.
+
+Load passes most patterns directly to the underlying build tool,
+but all patterns with the prefix "query=", where query is a
+non-empty string of letters from [a-z], are reserved and may be
+interpreted as query operators.
+
+Two query operators are currently supported: "file" and "pattern".
+
+The query "file=path/to/file.go" matches the package or packages enclosing
+the Go source file path/to/file.go.  For example "file=~/go/src/fmt/print.go"
+might return the packages "fmt" and "fmt [fmt.test]".
+
+The query "pattern=string" causes "string" to be passed directly to
+the underlying build tool. In most cases this is unnecessary,
+but an application can use Load("pattern=" + x) as an escaping mechanism
+to ensure that x is not interpreted as a query operator if it contains '='.
+
+All other query operators are reserved for future use and currently
+cause Load to report an error.
+
+The Package struct provides basic information about the package, including
+
+  - ID, a unique identifier for the package in the returned set;
+  - GoFiles, the names of the package's Go source files;
+  - Imports, a map from source import strings to the Packages they name;
+  - Types, the type information for the package's exported symbols;
+  - Syntax, the parsed syntax trees for the package's source code; and
+  - TypeInfo, the result of a complete type-check of the package syntax trees.
+
+(See the documentation for type Package for the complete list of fields
+and more detailed descriptions.)
+
+For example,
+
+	Load(nil, "bytes", "unicode...")
+
+returns four Package structs describing the standard library packages
+bytes, unicode, unicode/utf16, and unicode/utf8. Note that one pattern
+can match multiple packages and that a package might be matched by
+multiple patterns: in general it is not possible to determine which
+packages correspond to which patterns.
+
+Note that the list returned by Load contains only the packages matched
+by the patterns. Their dependencies can be found by walking the import
+graph using the Imports fields.
+
+The Load function can be configured by passing a pointer to a Config as
+the first argument. A nil Config is equivalent to the zero Config, which
+causes Load to run in LoadFiles mode, collecting minimal information.
+See the documentation for type Config for details.
+
+As noted earlier, the Config.Mode controls the amount of detail
+reported about the loaded packages, with each mode returning all the data of the
+previous mode with some extra added. See the documentation for type LoadMode
+for details.
+
+Most tools should pass their command-line arguments (after any flags)
+uninterpreted to the loader, so that the loader can interpret them
+according to the conventions of the underlying build system.
+See the Example function for typical usage.
+
+*/
+package packages // import "golang.org/x/tools/go/packages"
+
+/*
+
+Motivation and design considerations
+
+The new package's design solves problems addressed by two existing
+packages: go/build, which locates and describes packages, and
+golang.org/x/tools/go/loader, which loads, parses and type-checks them.
+The go/build.Package structure encodes too much of the 'go build' way
+of organizing projects, leaving us in need of a data type that describes a
+package of Go source code independent of the underlying build system.
+We wanted something that works equally well with go build and vgo, and
+also other build systems such as Bazel and Blaze, making it possible to
+construct analysis tools that work in all these environments.
+Tools such as errcheck and staticcheck were essentially unavailable to
+the Go community at Google, and some of Google's internal tools for Go
+are unavailable externally.
+This new package provides a uniform way to obtain package metadata by
+querying each of these build systems, optionally supporting their
+preferred command-line notations for packages, so that tools integrate
+neatly with users' build environments. The Metadata query function
+executes an external query tool appropriate to the current workspace.
+
+Loading packages always returns the complete import graph "all the way down",
+even if all you want is information about a single package, because the query
+mechanisms of all the build systems we currently support ({go,vgo} list, and
+blaze/bazel aspect-based query) cannot provide detailed information
+about one package without visiting all its dependencies too, so there is
+no additional asymptotic cost to providing transitive information.
+(This property might not be true of a hypothetical 5th build system.)
+
+In calls to TypeCheck, all initial packages, and any package that
+transitively depends on one of them, must be loaded from source.
+Consider A->B->C->D->E: if A,C are initial, A,B,C must be loaded from
+source; D may be loaded from export data, and E may not be loaded at all
+(though it's possible that D's export data mentions it, so a
+types.Package may be created for it and exposed.)
+
+The old loader had a feature to suppress type-checking of function
+bodies on a per-package basis, primarily intended to reduce the work of
+obtaining type information for imported packages. Now that imports are
+satisfied by export data, the optimization no longer seems necessary.
+
+Despite some early attempts, the old loader did not exploit export data,
+instead always using the equivalent of WholeProgram mode. This was due
+to the complexity of mixing source and export data packages (now
+resolved by the upward traversal mentioned above), and because export data
+files were nearly always missing or stale. Now that 'go build' supports
+caching, all the underlying build systems can guarantee to produce
+export data in a reasonable (amortized) time.
+
+Test "main" packages synthesized by the build system are now reported as
+first-class packages, avoiding the need for clients (such as go/ssa) to
+reinvent this generation logic.
+
+One way in which go/packages is simpler than the old loader is in its
+treatment of in-package tests. In-package tests are packages that
+consist of all the files of the library under test, plus the test files.
+The old loader constructed in-package tests by a two-phase process of
+mutation called "augmentation": first it would construct and type check
+all the ordinary library packages and type-check the packages that
+depend on them; then it would add more (test) files to the package and
+type-check again. This two-phase approach had four major problems:
+1) in processing the tests, the loader modified the library package,
+   leaving no way for a client application to see both the test
+   package and the library package; one would mutate into the other.
+2) because test files can declare additional methods on types defined in
+   the library portion of the package, the dispatch of method calls in
+   the library portion was affected by the presence of the test files.
+   This should have been a clue that the packages were logically
+   different.
+3) this model of "augmentation" assumed at most one in-package test
+   per library package, which is true of projects using 'go build',
+   but not other build systems.
+4) because of the two-phase nature of test processing, all packages that
+   import the library package had to be processed before augmentation,
+   forcing a "one-shot" API and preventing the client from calling Load
+   in several times in sequence as is now possible in WholeProgram mode.
+   (TypeCheck mode has a similar one-shot restriction for a different reason.)
+
+Early drafts of this package supported "multi-shot" operation.
+Although it allowed clients to make a sequence of calls (or concurrent
+calls) to Load, building up the graph of Packages incrementally,
+it was of marginal value: it complicated the API
+(since it allowed some options to vary across calls but not others),
+it complicated the implementation,
+it cannot be made to work in Types mode, as explained above,
+and it was less efficient than making one combined call (when this is possible).
+Among the clients we have inspected, none made multiple calls to load
+but could not be easily and satisfactorily modified to make only a single call.
+However, applications changes may be required.
+For example, the ssadump command loads the user-specified packages
+and in addition the runtime package.  It is tempting to simply append
+"runtime" to the user-provided list, but that does not work if the user
+specified an ad-hoc package such as [a.go b.go].
+Instead, ssadump no longer requests the runtime package,
+but seeks it among the dependencies of the user-specified packages,
+and emits an error if it is not found.
+
+Overlays: The Overlay field in the Config allows providing alternate contents
+for Go source files, by providing a mapping from file path to contents.
+go/packages will pull in new imports added in overlay files when go/packages
+is run in LoadImports mode or greater.
+Overlay support for the go list driver isn't complete yet: if the file doesn't
+exist on disk, it will only be recognized in an overlay if it is a non-test file
+and the package would be reported even without the overlay.
+
+Questions & Tasks
+
+- Add GOARCH/GOOS?
+  They are not portable concepts, but could be made portable.
+  Our goal has been to allow users to express themselves using the conventions
+  of the underlying build system: if the build system honors GOARCH
+  during a build and during a metadata query, then so should
+  applications built atop that query mechanism.
+  Conversely, if the target architecture of the build is determined by
+  command-line flags, the application can pass the relevant
+  flags through to the build system using a command such as:
+    myapp -query_flag="--cpu=amd64" -query_flag="--os=darwin"
+  However, this approach is low-level, unwieldy, and non-portable.
+  GOOS and GOARCH seem important enough to warrant a dedicated option.
+
+- How should we handle partial failures such as a mixture of good and
+  malformed patterns, existing and non-existent packages, successful and
+  failed builds, import failures, import cycles, and so on, in a call to
+  Load?
+
+- Support bazel, blaze, and go1.10 list, not just go1.11 list.
+
+- Handle (and test) various partial success cases, e.g.
+  a mixture of good packages and:
+  invalid patterns
+  nonexistent packages
+  empty packages
+  packages with malformed package or import declarations
+  unreadable files
+  import cycles
+  other parse errors
+  type errors
+  Make sure we record errors at the correct place in the graph.
+
+- Missing packages among initial arguments are not reported.
+  Return bogus packages for them, like golist does.
+
+- "undeclared name" errors (for example) are reported out of source file
+  order. I suspect this is due to the breadth-first resolution now used
+  by go/types. Is that a bug? Discuss with gri.
+
+*/

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

@@ -0,0 +1,79 @@
+// 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.
+
+// This file enables an external tool to intercept package requests.
+// If the tool is present then its results are used in preference to
+// the go list command.
+
+package packages
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"os/exec"
+	"strings"
+)
+
+// Driver
+type driverRequest struct {
+	Command    string            `json:"command"`
+	Mode       LoadMode          `json:"mode"`
+	Env        []string          `json:"env"`
+	BuildFlags []string          `json:"build_flags"`
+	Tests      bool              `json:"tests"`
+	Overlay    map[string][]byte `json:"overlay"`
+}
+
+// findExternalDriver returns the file path of a tool that supplies
+// the build system package structure, or "" if not found."
+// If GOPACKAGESDRIVER is set in the environment findExternalTool returns its
+// value, otherwise it searches for a binary named gopackagesdriver on the PATH.
+func findExternalDriver(cfg *Config) driver {
+	const toolPrefix = "GOPACKAGESDRIVER="
+	tool := ""
+	for _, env := range cfg.Env {
+		if val := strings.TrimPrefix(env, toolPrefix); val != env {
+			tool = val
+		}
+	}
+	if tool != "" && tool == "off" {
+		return nil
+	}
+	if tool == "" {
+		var err error
+		tool, err = exec.LookPath("gopackagesdriver")
+		if err != nil {
+			return nil
+		}
+	}
+	return func(cfg *Config, words ...string) (*driverResponse, error) {
+		req, err := json.Marshal(driverRequest{
+			Mode:       cfg.Mode,
+			Env:        cfg.Env,
+			BuildFlags: cfg.BuildFlags,
+			Tests:      cfg.Tests,
+			Overlay:    cfg.Overlay,
+		})
+		if err != nil {
+			return nil, fmt.Errorf("failed to encode message to driver tool: %v", err)
+		}
+
+		buf := new(bytes.Buffer)
+		cmd := exec.CommandContext(cfg.Context, tool, words...)
+		cmd.Dir = cfg.Dir
+		cmd.Env = cfg.Env
+		cmd.Stdin = bytes.NewReader(req)
+		cmd.Stdout = buf
+		cmd.Stderr = new(bytes.Buffer)
+		if err := cmd.Run(); err != nil {
+			return nil, fmt.Errorf("%v: %v: %s", tool, err, cmd.Stderr)
+		}
+		var response driverResponse
+		if err := json.Unmarshal(buf.Bytes(), &response); err != nil {
+			return nil, err
+		}
+		return &response, nil
+	}
+}

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

@@ -0,0 +1,821 @@
+// 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 packages
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"go/types"
+	"io/ioutil"
+	"log"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"reflect"
+	"regexp"
+	"strconv"
+	"strings"
+	"sync"
+	"time"
+
+	"golang.org/x/tools/go/internal/packagesdriver"
+	"golang.org/x/tools/internal/gopathwalk"
+	"golang.org/x/tools/internal/semver"
+)
+
+// debug controls verbose logging.
+var debug, _ = strconv.ParseBool(os.Getenv("GOPACKAGESDEBUG"))
+
+// A goTooOldError reports that the go command
+// found by exec.LookPath is too old to use the new go list behavior.
+type goTooOldError struct {
+	error
+}
+
+// responseDeduper wraps a driverResponse, deduplicating its contents.
+type responseDeduper struct {
+	seenRoots    map[string]bool
+	seenPackages map[string]*Package
+	dr           *driverResponse
+}
+
+// init fills in r with a driverResponse.
+func (r *responseDeduper) init(dr *driverResponse) {
+	r.dr = dr
+	r.seenRoots = map[string]bool{}
+	r.seenPackages = map[string]*Package{}
+	for _, pkg := range dr.Packages {
+		r.seenPackages[pkg.ID] = pkg
+	}
+	for _, root := range dr.Roots {
+		r.seenRoots[root] = true
+	}
+}
+
+func (r *responseDeduper) addPackage(p *Package) {
+	if r.seenPackages[p.ID] != nil {
+		return
+	}
+	r.seenPackages[p.ID] = p
+	r.dr.Packages = append(r.dr.Packages, p)
+}
+
+func (r *responseDeduper) addRoot(id string) {
+	if r.seenRoots[id] {
+		return
+	}
+	r.seenRoots[id] = true
+	r.dr.Roots = append(r.dr.Roots, id)
+}
+
+// goListDriver uses the go list command to interpret the patterns and produce
+// the build system package structure.
+// See driver for more details.
+func goListDriver(cfg *Config, patterns ...string) (*driverResponse, error) {
+	var sizes types.Sizes
+	var sizeserr error
+	var sizeswg sync.WaitGroup
+	if cfg.Mode&NeedTypesSizes != 0 {
+		sizeswg.Add(1)
+		go func() {
+			sizes, sizeserr = getSizes(cfg)
+			sizeswg.Done()
+		}()
+	}
+
+	// Determine files requested in contains patterns
+	var containFiles []string
+	var packagesNamed []string
+	restPatterns := make([]string, 0, len(patterns))
+	// Extract file= and other [querytype]= patterns. Report an error if querytype
+	// doesn't exist.
+extractQueries:
+	for _, pattern := range patterns {
+		eqidx := strings.Index(pattern, "=")
+		if eqidx < 0 {
+			restPatterns = append(restPatterns, pattern)
+		} else {
+			query, value := pattern[:eqidx], pattern[eqidx+len("="):]
+			switch query {
+			case "file":
+				containFiles = append(containFiles, value)
+			case "pattern":
+				restPatterns = append(restPatterns, value)
+			case "iamashamedtousethedisabledqueryname":
+				packagesNamed = append(packagesNamed, value)
+			case "": // not a reserved query
+				restPatterns = append(restPatterns, pattern)
+			default:
+				for _, rune := range query {
+					if rune < 'a' || rune > 'z' { // not a reserved query
+						restPatterns = append(restPatterns, pattern)
+						continue extractQueries
+					}
+				}
+				// Reject all other patterns containing "="
+				return nil, fmt.Errorf("invalid query type %q in query pattern %q", query, pattern)
+			}
+		}
+	}
+
+	response := &responseDeduper{}
+	var err error
+
+	// See if we have any patterns to pass through to go list. Zero initial
+	// patterns also requires a go list call, since it's the equivalent of
+	// ".".
+	if len(restPatterns) > 0 || len(patterns) == 0 {
+		dr, err := golistDriver(cfg, restPatterns...)
+		if err != nil {
+			return nil, err
+		}
+		response.init(dr)
+	} else {
+		response.init(&driverResponse{})
+	}
+
+	sizeswg.Wait()
+	if sizeserr != nil {
+		return nil, sizeserr
+	}
+	// types.SizesFor always returns nil or a *types.StdSizes
+	response.dr.Sizes, _ = sizes.(*types.StdSizes)
+
+	var containsCandidates []string
+
+	if len(containFiles) != 0 {
+		if err := runContainsQueries(cfg, golistDriver, response, containFiles); err != nil {
+			return nil, err
+		}
+	}
+
+	if len(packagesNamed) != 0 {
+		if err := runNamedQueries(cfg, golistDriver, response, packagesNamed); err != nil {
+			return nil, err
+		}
+	}
+
+	modifiedPkgs, needPkgs, err := processGolistOverlay(cfg, response.dr)
+	if err != nil {
+		return nil, err
+	}
+	if len(containFiles) > 0 {
+		containsCandidates = append(containsCandidates, modifiedPkgs...)
+		containsCandidates = append(containsCandidates, needPkgs...)
+	}
+
+	if len(needPkgs) > 0 {
+		addNeededOverlayPackages(cfg, golistDriver, response, needPkgs)
+		if err != nil {
+			return nil, err
+		}
+	}
+	// Check candidate packages for containFiles.
+	if len(containFiles) > 0 {
+		for _, id := range containsCandidates {
+			pkg := response.seenPackages[id]
+			for _, f := range containFiles {
+				for _, g := range pkg.GoFiles {
+					if sameFile(f, g) {
+						response.addRoot(id)
+					}
+				}
+			}
+		}
+	}
+
+	return response.dr, nil
+}
+
+func addNeededOverlayPackages(cfg *Config, driver driver, response *responseDeduper, pkgs []string) error {
+	dr, err := driver(cfg, pkgs...)
+	if err != nil {
+		return err
+	}
+	for _, pkg := range dr.Packages {
+		response.addPackage(pkg)
+	}
+	return nil
+}
+
+func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, queries []string) error {
+	for _, query := range queries {
+		// TODO(matloob): Do only one query per directory.
+		fdir := filepath.Dir(query)
+		// Pass absolute path of directory to go list so that it knows to treat it as a directory,
+		// not a package path.
+		pattern, err := filepath.Abs(fdir)
+		if err != nil {
+			return fmt.Errorf("could not determine absolute path of file= query path %q: %v", query, err)
+		}
+		dirResponse, err := driver(cfg, pattern)
+		if err != nil {
+			return err
+		}
+		isRoot := make(map[string]bool, len(dirResponse.Roots))
+		for _, root := range dirResponse.Roots {
+			isRoot[root] = true
+		}
+		for _, pkg := range dirResponse.Packages {
+			// Add any new packages to the main set
+			// We don't bother to filter packages that will be dropped by the changes of roots,
+			// that will happen anyway during graph construction outside this function.
+			// Over-reporting packages is not a problem.
+			response.addPackage(pkg)
+			// if the package was not a root one, it cannot have the file
+			if !isRoot[pkg.ID] {
+				continue
+			}
+			for _, pkgFile := range pkg.GoFiles {
+				if filepath.Base(query) == filepath.Base(pkgFile) {
+					response.addRoot(pkg.ID)
+					break
+				}
+			}
+		}
+	}
+	return nil
+}
+
+// modCacheRegexp splits a path in a module cache into module, module version, and package.
+var modCacheRegexp = regexp.MustCompile(`(.*)@([^/\\]*)(.*)`)
+
+func runNamedQueries(cfg *Config, driver driver, response *responseDeduper, queries []string) error {
+	// calling `go env` isn't free; bail out if there's nothing to do.
+	if len(queries) == 0 {
+		return nil
+	}
+	// Determine which directories are relevant to scan.
+	roots, modRoot, err := roots(cfg)
+	if err != nil {
+		return err
+	}
+
+	// Scan the selected directories. Simple matches, from GOPATH/GOROOT
+	// or the local module, can simply be "go list"ed. Matches from the
+	// module cache need special treatment.
+	var matchesMu sync.Mutex
+	var simpleMatches, modCacheMatches []string
+	add := func(root gopathwalk.Root, dir string) {
+		// Walk calls this concurrently; protect the result slices.
+		matchesMu.Lock()
+		defer matchesMu.Unlock()
+
+		path := dir
+		if dir != root.Path {
+			path = dir[len(root.Path)+1:]
+		}
+		if pathMatchesQueries(path, queries) {
+			switch root.Type {
+			case gopathwalk.RootModuleCache:
+				modCacheMatches = append(modCacheMatches, path)
+			case gopathwalk.RootCurrentModule:
+				// We'd need to read go.mod to find the full
+				// import path. Relative's easier.
+				rel, err := filepath.Rel(cfg.Dir, dir)
+				if err != nil {
+					// This ought to be impossible, since
+					// we found dir in the current module.
+					panic(err)
+				}
+				simpleMatches = append(simpleMatches, "./"+rel)
+			case gopathwalk.RootGOPATH, gopathwalk.RootGOROOT:
+				simpleMatches = append(simpleMatches, path)
+			}
+		}
+	}
+
+	startWalk := time.Now()
+	gopathwalk.Walk(roots, add, gopathwalk.Options{ModulesEnabled: modRoot != "", Debug: debug})
+	if debug {
+		log.Printf("%v for walk", time.Since(startWalk))
+	}
+
+	// Weird special case: the top-level package in a module will be in
+	// whatever directory the user checked the repository out into. It's
+	// more reasonable for that to not match the package name. So, if there
+	// are any Go files in the mod root, query it just to be safe.
+	if modRoot != "" {
+		rel, err := filepath.Rel(cfg.Dir, modRoot)
+		if err != nil {
+			panic(err) // See above.
+		}
+
+		files, err := ioutil.ReadDir(modRoot)
+		for _, f := range files {
+			if strings.HasSuffix(f.Name(), ".go") {
+				simpleMatches = append(simpleMatches, rel)
+				break
+			}
+		}
+	}
+
+	addResponse := func(r *driverResponse) {
+		for _, pkg := range r.Packages {
+			response.addPackage(pkg)
+			for _, name := range queries {
+				if pkg.Name == name {
+					response.addRoot(pkg.ID)
+					break
+				}
+			}
+		}
+	}
+
+	if len(simpleMatches) != 0 {
+		resp, err := driver(cfg, simpleMatches...)
+		if err != nil {
+			return err
+		}
+		addResponse(resp)
+	}
+
+	// Module cache matches are tricky. We want to avoid downloading new
+	// versions of things, so we need to use the ones present in the cache.
+	// go list doesn't accept version specifiers, so we have to write out a
+	// temporary module, and do the list in that module.
+	if len(modCacheMatches) != 0 {
+		// Collect all the matches, deduplicating by major version
+		// and preferring the newest.
+		type modInfo struct {
+			mod   string
+			major string
+		}
+		mods := make(map[modInfo]string)
+		var imports []string
+		for _, modPath := range modCacheMatches {
+			matches := modCacheRegexp.FindStringSubmatch(modPath)
+			mod, ver := filepath.ToSlash(matches[1]), matches[2]
+			importPath := filepath.ToSlash(filepath.Join(matches[1], matches[3]))
+
+			major := semver.Major(ver)
+			if prevVer, ok := mods[modInfo{mod, major}]; !ok || semver.Compare(ver, prevVer) > 0 {
+				mods[modInfo{mod, major}] = ver
+			}
+
+			imports = append(imports, importPath)
+		}
+
+		// Build the temporary module.
+		var gomod bytes.Buffer
+		gomod.WriteString("module modquery\nrequire (\n")
+		for mod, version := range mods {
+			gomod.WriteString("\t" + mod.mod + " " + version + "\n")
+		}
+		gomod.WriteString(")\n")
+
+		tmpCfg := *cfg
+
+		// We're only trying to look at stuff in the module cache, so
+		// disable the network. This should speed things up, and has
+		// prevented errors in at least one case, #28518.
+		tmpCfg.Env = append(append([]string{"GOPROXY=off"}, cfg.Env...))
+
+		var err error
+		tmpCfg.Dir, err = ioutil.TempDir("", "gopackages-modquery")
+		if err != nil {
+			return err
+		}
+		defer os.RemoveAll(tmpCfg.Dir)
+
+		if err := ioutil.WriteFile(filepath.Join(tmpCfg.Dir, "go.mod"), gomod.Bytes(), 0777); err != nil {
+			return fmt.Errorf("writing go.mod for module cache query: %v", err)
+		}
+
+		// Run the query, using the import paths calculated from the matches above.
+		resp, err := driver(&tmpCfg, imports...)
+		if err != nil {
+			return fmt.Errorf("querying module cache matches: %v", err)
+		}
+		addResponse(resp)
+	}
+
+	return nil
+}
+
+func getSizes(cfg *Config) (types.Sizes, error) {
+	return packagesdriver.GetSizesGolist(cfg.Context, cfg.BuildFlags, cfg.Env, cfg.Dir, usesExportData(cfg))
+}
+
+// roots selects the appropriate paths to walk based on the passed-in configuration,
+// particularly the environment and the presence of a go.mod in cfg.Dir's parents.
+func roots(cfg *Config) ([]gopathwalk.Root, string, error) {
+	stdout, err := invokeGo(cfg, "env", "GOROOT", "GOPATH", "GOMOD")
+	if err != nil {
+		return nil, "", err
+	}
+
+	fields := strings.Split(stdout.String(), "\n")
+	if len(fields) != 4 || len(fields[3]) != 0 {
+		return nil, "", fmt.Errorf("go env returned unexpected output: %q", stdout.String())
+	}
+	goroot, gopath, gomod := fields[0], filepath.SplitList(fields[1]), fields[2]
+	var modDir string
+	if gomod != "" {
+		modDir = filepath.Dir(gomod)
+	}
+
+	var roots []gopathwalk.Root
+	// Always add GOROOT.
+	roots = append(roots, gopathwalk.Root{filepath.Join(goroot, "/src"), gopathwalk.RootGOROOT})
+	// If modules are enabled, scan the module dir.
+	if modDir != "" {
+		roots = append(roots, gopathwalk.Root{modDir, gopathwalk.RootCurrentModule})
+	}
+	// Add either GOPATH/src or GOPATH/pkg/mod, depending on module mode.
+	for _, p := range gopath {
+		if modDir != "" {
+			roots = append(roots, gopathwalk.Root{filepath.Join(p, "/pkg/mod"), gopathwalk.RootModuleCache})
+		} else {
+			roots = append(roots, gopathwalk.Root{filepath.Join(p, "/src"), gopathwalk.RootGOPATH})
+		}
+	}
+
+	return roots, modDir, nil
+}
+
+// These functions were copied from goimports. See further documentation there.
+
+// pathMatchesQueries is adapted from pkgIsCandidate.
+// TODO: is it reasonable to do Contains here, rather than an exact match on a path component?
+func pathMatchesQueries(path string, queries []string) bool {
+	lastTwo := lastTwoComponents(path)
+	for _, query := range queries {
+		if strings.Contains(lastTwo, query) {
+			return true
+		}
+		if hasHyphenOrUpperASCII(lastTwo) && !hasHyphenOrUpperASCII(query) {
+			lastTwo = lowerASCIIAndRemoveHyphen(lastTwo)
+			if strings.Contains(lastTwo, query) {
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// lastTwoComponents returns at most the last two path components
+// of v, using either / or \ as the path separator.
+func lastTwoComponents(v string) string {
+	nslash := 0
+	for i := len(v) - 1; i >= 0; i-- {
+		if v[i] == '/' || v[i] == '\\' {
+			nslash++
+			if nslash == 2 {
+				return v[i:]
+			}
+		}
+	}
+	return v
+}
+
+func hasHyphenOrUpperASCII(s string) bool {
+	for i := 0; i < len(s); i++ {
+		b := s[i]
+		if b == '-' || ('A' <= b && b <= 'Z') {
+			return true
+		}
+	}
+	return false
+}
+
+func lowerASCIIAndRemoveHyphen(s string) (ret string) {
+	buf := make([]byte, 0, len(s))
+	for i := 0; i < len(s); i++ {
+		b := s[i]
+		switch {
+		case b == '-':
+			continue
+		case 'A' <= b && b <= 'Z':
+			buf = append(buf, b+('a'-'A'))
+		default:
+			buf = append(buf, b)
+		}
+	}
+	return string(buf)
+}
+
+// Fields must match go list;
+// see $GOROOT/src/cmd/go/internal/load/pkg.go.
+type jsonPackage struct {
+	ImportPath      string
+	Dir             string
+	Name            string
+	Export          string
+	GoFiles         []string
+	CompiledGoFiles []string
+	CFiles          []string
+	CgoFiles        []string
+	CXXFiles        []string
+	MFiles          []string
+	HFiles          []string
+	FFiles          []string
+	SFiles          []string
+	SwigFiles       []string
+	SwigCXXFiles    []string
+	SysoFiles       []string
+	Imports         []string
+	ImportMap       map[string]string
+	Deps            []string
+	TestGoFiles     []string
+	TestImports     []string
+	XTestGoFiles    []string
+	XTestImports    []string
+	ForTest         string // q in a "p [q.test]" package, else ""
+	DepOnly         bool
+
+	Error *jsonPackageError
+}
+
+type jsonPackageError struct {
+	ImportStack []string
+	Pos         string
+	Err         string
+}
+
+func otherFiles(p *jsonPackage) [][]string {
+	return [][]string{p.CFiles, p.CXXFiles, p.MFiles, p.HFiles, p.FFiles, p.SFiles, p.SwigFiles, p.SwigCXXFiles, p.SysoFiles}
+}
+
+// golistDriver uses the "go list" command to expand the pattern
+// words and return metadata for the specified packages. dir may be
+// "" and env may be nil, as per os/exec.Command.
+func golistDriver(cfg *Config, words ...string) (*driverResponse, error) {
+	// go list uses the following identifiers in ImportPath and Imports:
+	//
+	// 	"p"			-- importable package or main (command)
+	//      "q.test"		-- q's test executable
+	// 	"p [q.test]"		-- variant of p as built for q's test executable
+	//	"q_test [q.test]"	-- q's external test package
+	//
+	// The packages p that are built differently for a test q.test
+	// are q itself, plus any helpers used by the external test q_test,
+	// typically including "testing" and all its dependencies.
+
+	// Run "go list" for complete
+	// information on the specified packages.
+	buf, err := invokeGo(cfg, golistargs(cfg, words)...)
+	if err != nil {
+		return nil, err
+	}
+	seen := make(map[string]*jsonPackage)
+	// Decode the JSON and convert it to Package form.
+	var response driverResponse
+	for dec := json.NewDecoder(buf); dec.More(); {
+		p := new(jsonPackage)
+		if err := dec.Decode(p); err != nil {
+			return nil, fmt.Errorf("JSON decoding failed: %v", err)
+		}
+
+		if p.ImportPath == "" {
+			// The documentation for go list says that “[e]rroneous packages will have
+			// a non-empty ImportPath”. If for some reason it comes back empty, we
+			// prefer to error out rather than silently discarding data or handing
+			// back a package without any way to refer to it.
+			if p.Error != nil {
+				return nil, Error{
+					Pos: p.Error.Pos,
+					Msg: p.Error.Err,
+				}
+			}
+			return nil, fmt.Errorf("package missing import path: %+v", p)
+		}
+
+		if old, found := seen[p.ImportPath]; found {
+			if !reflect.DeepEqual(p, old) {
+				return nil, fmt.Errorf("internal error: go list gives conflicting information for package %v", p.ImportPath)
+			}
+			// skip the duplicate
+			continue
+		}
+		seen[p.ImportPath] = p
+
+		pkg := &Package{
+			Name:            p.Name,
+			ID:              p.ImportPath,
+			GoFiles:         absJoin(p.Dir, p.GoFiles, p.CgoFiles),
+			CompiledGoFiles: absJoin(p.Dir, p.CompiledGoFiles),
+			OtherFiles:      absJoin(p.Dir, otherFiles(p)...),
+		}
+
+		// Work around https://golang.org/issue/28749:
+		// cmd/go puts assembly, C, and C++ files in CompiledGoFiles.
+		// Filter out any elements of CompiledGoFiles that are also in OtherFiles.
+		// We have to keep this workaround in place until go1.12 is a distant memory.
+		if len(pkg.OtherFiles) > 0 {
+			other := make(map[string]bool, len(pkg.OtherFiles))
+			for _, f := range pkg.OtherFiles {
+				other[f] = true
+			}
+
+			out := pkg.CompiledGoFiles[:0]
+			for _, f := range pkg.CompiledGoFiles {
+				if other[f] {
+					continue
+				}
+				out = append(out, f)
+			}
+			pkg.CompiledGoFiles = out
+		}
+
+		// Extract the PkgPath from the package's ID.
+		if i := strings.IndexByte(pkg.ID, ' '); i >= 0 {
+			pkg.PkgPath = pkg.ID[:i]
+		} else {
+			pkg.PkgPath = pkg.ID
+		}
+
+		if pkg.PkgPath == "unsafe" {
+			pkg.GoFiles = nil // ignore fake unsafe.go file
+		}
+
+		// Assume go list emits only absolute paths for Dir.
+		if p.Dir != "" && !filepath.IsAbs(p.Dir) {
+			log.Fatalf("internal error: go list returned non-absolute Package.Dir: %s", p.Dir)
+		}
+
+		if p.Export != "" && !filepath.IsAbs(p.Export) {
+			pkg.ExportFile = filepath.Join(p.Dir, p.Export)
+		} else {
+			pkg.ExportFile = p.Export
+		}
+
+		// imports
+		//
+		// Imports contains the IDs of all imported packages.
+		// ImportsMap records (path, ID) only where they differ.
+		ids := make(map[string]bool)
+		for _, id := range p.Imports {
+			ids[id] = true
+		}
+		pkg.Imports = make(map[string]*Package)
+		for path, id := range p.ImportMap {
+			pkg.Imports[path] = &Package{ID: id} // non-identity import
+			delete(ids, id)
+		}
+		for id := range ids {
+			if id == "C" {
+				continue
+			}
+
+			pkg.Imports[id] = &Package{ID: id} // identity import
+		}
+		if !p.DepOnly {
+			response.Roots = append(response.Roots, pkg.ID)
+		}
+
+		// Work around for pre-go.1.11 versions of go list.
+		// TODO(matloob): they should be handled by the fallback.
+		// Can we delete this?
+		if len(pkg.CompiledGoFiles) == 0 {
+			pkg.CompiledGoFiles = pkg.GoFiles
+		}
+
+		if p.Error != nil {
+			pkg.Errors = append(pkg.Errors, Error{
+				Pos: p.Error.Pos,
+				Msg: p.Error.Err,
+			})
+		}
+
+		response.Packages = append(response.Packages, pkg)
+	}
+
+	return &response, nil
+}
+
+// absJoin absolutizes and flattens the lists of files.
+func absJoin(dir string, fileses ...[]string) (res []string) {
+	for _, files := range fileses {
+		for _, file := range files {
+			if !filepath.IsAbs(file) {
+				file = filepath.Join(dir, file)
+			}
+			res = append(res, file)
+		}
+	}
+	return res
+}
+
+func golistargs(cfg *Config, words []string) []string {
+	const findFlags = NeedImports | NeedTypes | NeedSyntax | NeedTypesInfo
+	fullargs := []string{
+		"list", "-e", "-json",
+		fmt.Sprintf("-compiled=%t", cfg.Mode&(NeedCompiledGoFiles|NeedSyntax|NeedTypesInfo|NeedTypesSizes) != 0),
+		fmt.Sprintf("-test=%t", cfg.Tests),
+		fmt.Sprintf("-export=%t", usesExportData(cfg)),
+		fmt.Sprintf("-deps=%t", cfg.Mode&NeedDeps != 0),
+		// go list doesn't let you pass -test and -find together,
+		// probably because you'd just get the TestMain.
+		fmt.Sprintf("-find=%t", !cfg.Tests && cfg.Mode&findFlags == 0),
+	}
+	fullargs = append(fullargs, cfg.BuildFlags...)
+	fullargs = append(fullargs, "--")
+	fullargs = append(fullargs, words...)
+	return fullargs
+}
+
+// invokeGo returns the stdout of a go command invocation.
+func invokeGo(cfg *Config, args ...string) (*bytes.Buffer, error) {
+	stdout := new(bytes.Buffer)
+	stderr := new(bytes.Buffer)
+	cmd := exec.CommandContext(cfg.Context, "go", args...)
+	// On darwin the cwd gets resolved to the real path, which breaks anything that
+	// expects the working directory to keep the original path, including the
+	// go command when dealing with modules.
+	// The Go stdlib has a special feature where if the cwd and the PWD are the
+	// same node then it trusts the PWD, so by setting it in the env for the child
+	// process we fix up all the paths returned by the go command.
+	cmd.Env = append(append([]string{}, cfg.Env...), "PWD="+cfg.Dir)
+	cmd.Dir = cfg.Dir
+	cmd.Stdout = stdout
+	cmd.Stderr = stderr
+	if debug {
+		defer func(start time.Time) {
+			log.Printf("%s for %v, stderr: <<%s>>\n", time.Since(start), cmdDebugStr(cmd, args...), stderr)
+		}(time.Now())
+	}
+
+	if err := cmd.Run(); err != nil {
+		// Check for 'go' executable not being found.
+		if ee, ok := err.(*exec.Error); ok && ee.Err == exec.ErrNotFound {
+			return nil, fmt.Errorf("'go list' driver requires 'go', but %s", exec.ErrNotFound)
+		}
+
+		exitErr, ok := err.(*exec.ExitError)
+		if !ok {
+			// Catastrophic error:
+			// - context cancellation
+			return nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err)
+		}
+
+		// Old go version?
+		if strings.Contains(stderr.String(), "flag provided but not defined") {
+			return nil, goTooOldError{fmt.Errorf("unsupported version of go: %s: %s", exitErr, stderr)}
+		}
+
+		// This error only appears in stderr. See golang.org/cl/166398 for a fix in go list to show
+		// the error in the Err section of stdout in case -e option is provided.
+		// This fix is provided for backwards compatibility.
+		if len(stderr.String()) > 0 && strings.Contains(stderr.String(), "named files must be .go files") {
+			output := fmt.Sprintf(`{"ImportPath": "","Incomplete": true,"Error": {"Pos": "","Err": %s}}`,
+				strconv.Quote(strings.Trim(stderr.String(), "\n")))
+			return bytes.NewBufferString(output), nil
+		}
+
+		// Export mode entails a build.
+		// If that build fails, errors appear on stderr
+		// (despite the -e flag) and the Export field is blank.
+		// Do not fail in that case.
+		// The same is true if an ad-hoc package given to go list doesn't exist.
+		// TODO(matloob): Remove these once we can depend on go list to exit with a zero status with -e even when
+		// packages don't exist or a build fails.
+		if !usesExportData(cfg) && !containsGoFile(args) {
+			return nil, fmt.Errorf("go %v: %s: %s", args, exitErr, stderr)
+		}
+	}
+
+	// As of writing, go list -export prints some non-fatal compilation
+	// errors to stderr, even with -e set. We would prefer that it put
+	// them in the Package.Error JSON (see https://golang.org/issue/26319).
+	// In the meantime, there's nowhere good to put them, but they can
+	// be useful for debugging. Print them if $GOPACKAGESPRINTGOLISTERRORS
+	// is set.
+	if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTGOLISTERRORS") != "" {
+		fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(cmd, args...), stderr)
+	}
+
+	// debugging
+	if false {
+		fmt.Fprintf(os.Stderr, "%s stdout: <<%s>>\n", cmdDebugStr(cmd, args...), stdout)
+	}
+
+	return stdout, nil
+}
+
+func containsGoFile(s []string) bool {
+	for _, f := range s {
+		if strings.HasSuffix(f, ".go") {
+			return true
+		}
+	}
+	return false
+}
+
+func cmdDebugStr(cmd *exec.Cmd, args ...string) string {
+	env := make(map[string]string)
+	for _, kv := range cmd.Env {
+		split := strings.Split(kv, "=")
+		k, v := split[0], split[1]
+		env[k] = v
+	}
+	var quotedArgs []string
+	for _, arg := range args {
+		quotedArgs = append(quotedArgs, strconv.Quote(arg))
+	}
+
+	return fmt.Sprintf("GOROOT=%v GOPATH=%v GO111MODULE=%v PWD=%v go %s", env["GOROOT"], env["GOPATH"], env["GO111MODULE"], env["PWD"], strings.Join(quotedArgs, " "))
+}

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

@@ -0,0 +1,104 @@
+package packages
+
+import (
+	"go/parser"
+	"go/token"
+	"path/filepath"
+	"strconv"
+	"strings"
+)
+
+// processGolistOverlay provides rudimentary support for adding
+// files that don't exist on disk to an overlay. The results can be
+// sometimes incorrect.
+// TODO(matloob): Handle unsupported cases, including the following:
+// - test files
+// - adding test and non-test files to test variants of packages
+// - determining the correct package to add given a new import path
+// - creating packages that don't exist
+func processGolistOverlay(cfg *Config, response *driverResponse) (modifiedPkgs, needPkgs []string, err error) {
+	havePkgs := make(map[string]string) // importPath -> non-test package ID
+	needPkgsSet := make(map[string]bool)
+	modifiedPkgsSet := make(map[string]bool)
+
+	for _, pkg := range response.Packages {
+		// This is an approximation of import path to id. This can be
+		// wrong for tests, vendored packages, and a number of other cases.
+		havePkgs[pkg.PkgPath] = pkg.ID
+	}
+
+outer:
+	for path, contents := range cfg.Overlay {
+		base := filepath.Base(path)
+		if strings.HasSuffix(path, "_test.go") {
+			// Overlays don't support adding new test files yet.
+			// TODO(matloob): support adding new test files.
+			continue
+		}
+		dir := filepath.Dir(path)
+		for _, pkg := range response.Packages {
+			var dirContains, fileExists bool
+			for _, f := range pkg.GoFiles {
+				if sameFile(filepath.Dir(f), dir) {
+					dirContains = true
+				}
+				if filepath.Base(f) == base {
+					fileExists = true
+				}
+			}
+			if dirContains {
+				if !fileExists {
+					pkg.GoFiles = append(pkg.GoFiles, path) // TODO(matloob): should the file just be added to GoFiles?
+					pkg.CompiledGoFiles = append(pkg.CompiledGoFiles, path)
+					modifiedPkgsSet[pkg.ID] = true
+				}
+				imports, err := extractImports(path, contents)
+				if err != nil {
+					// Let the parser or type checker report errors later.
+					continue outer
+				}
+				for _, imp := range imports {
+					_, found := pkg.Imports[imp]
+					if !found {
+						needPkgsSet[imp] = true
+						// TODO(matloob): Handle cases when the following block isn't correct.
+						// These include imports of test variants, imports of vendored packages, etc.
+						id, ok := havePkgs[imp]
+						if !ok {
+							id = imp
+						}
+						pkg.Imports[imp] = &Package{ID: id}
+					}
+				}
+				continue outer
+			}
+		}
+	}
+
+	needPkgs = make([]string, 0, len(needPkgsSet))
+	for pkg := range needPkgsSet {
+		needPkgs = append(needPkgs, pkg)
+	}
+	modifiedPkgs = make([]string, 0, len(modifiedPkgsSet))
+	for pkg := range modifiedPkgsSet {
+		modifiedPkgs = append(modifiedPkgs, pkg)
+	}
+	return modifiedPkgs, needPkgs, err
+}
+
+func extractImports(filename string, contents []byte) ([]string, error) {
+	f, err := parser.ParseFile(token.NewFileSet(), filename, contents, parser.ImportsOnly) // TODO(matloob): reuse fileset?
+	if err != nil {
+		return nil, err
+	}
+	var res []string
+	for _, imp := range f.Imports {
+		quotedPath := imp.Path.Value
+		path, err := strconv.Unquote(quotedPath)
+		if err != nil {
+			return nil, err
+		}
+		res = append(res, path)
+	}
+	return res, nil
+}

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

@@ -0,0 +1,55 @@
+package packages
+
+import (
+	"fmt"
+	"os"
+	"sort"
+)
+
+// Visit visits all the packages in the import graph whose roots are
+// pkgs, calling the optional pre function the first time each package
+// is encountered (preorder), and the optional post function after a
+// package's dependencies have been visited (postorder).
+// The boolean result of pre(pkg) determines whether
+// the imports of package pkg are visited.
+func Visit(pkgs []*Package, pre func(*Package) bool, post func(*Package)) {
+	seen := make(map[*Package]bool)
+	var visit func(*Package)
+	visit = func(pkg *Package) {
+		if !seen[pkg] {
+			seen[pkg] = true
+
+			if pre == nil || pre(pkg) {
+				paths := make([]string, 0, len(pkg.Imports))
+				for path := range pkg.Imports {
+					paths = append(paths, path)
+				}
+				sort.Strings(paths) // Imports is a map, this makes visit stable
+				for _, path := range paths {
+					visit(pkg.Imports[path])
+				}
+			}
+
+			if post != nil {
+				post(pkg)
+			}
+		}
+	}
+	for _, pkg := range pkgs {
+		visit(pkg)
+	}
+}
+
+// PrintErrors prints to os.Stderr the accumulated errors of all
+// packages in the import graph rooted at pkgs, dependencies first.
+// PrintErrors returns the number of errors printed.
+func PrintErrors(pkgs []*Package) int {
+	var n int
+	Visit(pkgs, nil, func(pkg *Package) {
+		for _, err := range pkg.Errors {
+			fmt.Fprintln(os.Stderr, err)
+			n++
+		}
+	})
+	return n
+}

vendor/golang.org/x/tools/go/types/typeutil/callee.go

@@ -0,0 +1,46 @@
+// 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 typeutil
+
+import (
+	"go/ast"
+	"go/types"
+
+	"golang.org/x/tools/go/ast/astutil"
+)
+
+// Callee returns the named target of a function call, if any:
+// a function, method, builtin, or variable.
+func Callee(info *types.Info, call *ast.CallExpr) types.Object {
+	var obj types.Object
+	switch fun := astutil.Unparen(call.Fun).(type) {
+	case *ast.Ident:
+		obj = info.Uses[fun] // type, var, builtin, or declared func
+	case *ast.SelectorExpr:
+		if sel, ok := info.Selections[fun]; ok {
+			obj = sel.Obj() // method or field
+		} else {
+			obj = info.Uses[fun.Sel] // qualified identifier?
+		}
+	}
+	if _, ok := obj.(*types.TypeName); ok {
+		return nil // T(x) is a conversion, not a call
+	}
+	return obj
+}
+
+// StaticCallee returns the target (function or method) of a static
+// function call, if any. It returns nil for calls to builtins.
+func StaticCallee(info *types.Info, call *ast.CallExpr) *types.Func {
+	if f, ok := Callee(info, call).(*types.Func); ok && !interfaceMethod(f) {
+		return f
+	}
+	return nil
+}
+
+func interfaceMethod(f *types.Func) bool {
+	recv := f.Type().(*types.Signature).Recv()
+	return recv != nil && types.IsInterface(recv.Type())
+}

vendor/golang.org/x/tools/go/types/typeutil/imports.go

@@ -0,0 +1,31 @@
+// Copyright 2014 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 typeutil
+
+import "go/types"
+
+// Dependencies returns all dependencies of the specified packages.
+//
+// Dependent packages appear in topological order: if package P imports
+// package Q, Q appears earlier than P in the result.
+// The algorithm follows import statements in the order they
+// appear in the source code, so the result is a total order.
+//
+func Dependencies(pkgs ...*types.Package) []*types.Package {
+	var result []*types.Package
+	seen := make(map[*types.Package]bool)
+	var visit func(pkgs []*types.Package)
+	visit = func(pkgs []*types.Package) {
+		for _, p := range pkgs {
+			if !seen[p] {
+				seen[p] = true
+				visit(p.Imports())
+				result = append(result, p)
+			}
+		}
+	}
+	visit(pkgs)
+	return result
+}

vendor/golang.org/x/tools/go/types/typeutil/map.go

@@ -0,0 +1,313 @@
+// Copyright 2014 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 typeutil defines various utilities for types, such as Map,
+// a mapping from types.Type to interface{} values.
+package typeutil // import "golang.org/x/tools/go/types/typeutil"
+
+import (
+	"bytes"
+	"fmt"
+	"go/types"
+	"reflect"
+)
+
+// Map is a hash-table-based mapping from types (types.Type) to
+// arbitrary interface{} values.  The concrete types that implement
+// the Type interface are pointers.  Since they are not canonicalized,
+// == cannot be used to check for equivalence, and thus we cannot
+// simply use a Go map.
+//
+// Just as with map[K]V, a nil *Map is a valid empty map.
+//
+// Not thread-safe.
+//
+type Map struct {
+	hasher Hasher             // shared by many Maps
+	table  map[uint32][]entry // maps hash to bucket; entry.key==nil means unused
+	length int                // number of map entries
+}
+
+// entry is an entry (key/value association) in a hash bucket.
+type entry struct {
+	key   types.Type
+	value interface{}
+}
+
+// SetHasher sets the hasher used by Map.
+//
+// All Hashers are functionally equivalent but contain internal state
+// used to cache the results of hashing previously seen types.
+//
+// A single Hasher created by MakeHasher() may be shared among many
+// Maps.  This is recommended if the instances have many keys in
+// common, as it will amortize the cost of hash computation.
+//
+// A Hasher may grow without bound as new types are seen.  Even when a
+// type is deleted from the map, the Hasher never shrinks, since other
+// types in the map may reference the deleted type indirectly.
+//
+// Hashers are not thread-safe, and read-only operations such as
+// Map.Lookup require updates to the hasher, so a full Mutex lock (not a
+// read-lock) is require around all Map operations if a shared
+// hasher is accessed from multiple threads.
+//
+// If SetHasher is not called, the Map will create a private hasher at
+// the first call to Insert.
+//
+func (m *Map) SetHasher(hasher Hasher) {
+	m.hasher = hasher
+}
+
+// Delete removes the entry with the given key, if any.
+// It returns true if the entry was found.
+//
+func (m *Map) Delete(key types.Type) bool {
+	if m != nil && m.table != nil {
+		hash := m.hasher.Hash(key)
+		bucket := m.table[hash]
+		for i, e := range bucket {
+			if e.key != nil && types.Identical(key, e.key) {
+				// We can't compact the bucket as it
+				// would disturb iterators.
+				bucket[i] = entry{}
+				m.length--
+				return true
+			}
+		}
+	}
+	return false
+}
+
+// At returns the map entry for the given key.
+// The result is nil if the entry is not present.
+//
+func (m *Map) At(key types.Type) interface{} {
+	if m != nil && m.table != nil {
+		for _, e := range m.table[m.hasher.Hash(key)] {
+			if e.key != nil && types.Identical(key, e.key) {
+				return e.value
+			}
+		}
+	}
+	return nil
+}
+
+// Set sets the map entry for key to val,
+// and returns the previous entry, if any.
+func (m *Map) Set(key types.Type, value interface{}) (prev interface{}) {
+	if m.table != nil {
+		hash := m.hasher.Hash(key)
+		bucket := m.table[hash]
+		var hole *entry
+		for i, e := range bucket {
+			if e.key == nil {
+				hole = &bucket[i]
+			} else if types.Identical(key, e.key) {
+				prev = e.value
+				bucket[i].value = value
+				return
+			}
+		}
+
+		if hole != nil {
+			*hole = entry{key, value} // overwrite deleted entry
+		} else {
+			m.table[hash] = append(bucket, entry{key, value})
+		}
+	} else {
+		if m.hasher.memo == nil {
+			m.hasher = MakeHasher()
+		}
+		hash := m.hasher.Hash(key)
+		m.table = map[uint32][]entry{hash: {entry{key, value}}}
+	}
+
+	m.length++
+	return
+}
+
+// Len returns the number of map entries.
+func (m *Map) Len() int {
+	if m != nil {
+		return m.length
+	}
+	return 0
+}
+
+// Iterate calls function f on each entry in the map in unspecified order.
+//
+// If f should mutate the map, Iterate provides the same guarantees as
+// Go maps: if f deletes a map entry that Iterate has not yet reached,
+// f will not be invoked for it, but if f inserts a map entry that
+// Iterate has not yet reached, whether or not f will be invoked for
+// it is unspecified.
+//
+func (m *Map) Iterate(f func(key types.Type, value interface{})) {
+	if m != nil {
+		for _, bucket := range m.table {
+			for _, e := range bucket {
+				if e.key != nil {
+					f(e.key, e.value)
+				}
+			}
+		}
+	}
+}
+
+// Keys returns a new slice containing the set of map keys.
+// The order is unspecified.
+func (m *Map) Keys() []types.Type {
+	keys := make([]types.Type, 0, m.Len())
+	m.Iterate(func(key types.Type, _ interface{}) {
+		keys = append(keys, key)
+	})
+	return keys
+}
+
+func (m *Map) toString(values bool) string {
+	if m == nil {
+		return "{}"
+	}
+	var buf bytes.Buffer
+	fmt.Fprint(&buf, "{")
+	sep := ""
+	m.Iterate(func(key types.Type, value interface{}) {
+		fmt.Fprint(&buf, sep)
+		sep = ", "
+		fmt.Fprint(&buf, key)
+		if values {
+			fmt.Fprintf(&buf, ": %q", value)
+		}
+	})
+	fmt.Fprint(&buf, "}")
+	return buf.String()
+}
+
+// String returns a string representation of the map's entries.
+// Values are printed using fmt.Sprintf("%v", v).
+// Order is unspecified.
+//
+func (m *Map) String() string {
+	return m.toString(true)
+}
+
+// KeysString returns a string representation of the map's key set.
+// Order is unspecified.
+//
+func (m *Map) KeysString() string {
+	return m.toString(false)
+}
+
+////////////////////////////////////////////////////////////////////////
+// Hasher
+
+// A Hasher maps each type to its hash value.
+// For efficiency, a hasher uses memoization; thus its memory
+// footprint grows monotonically over time.
+// Hashers are not thread-safe.
+// Hashers have reference semantics.
+// Call MakeHasher to create a Hasher.
+type Hasher struct {
+	memo map[types.Type]uint32
+}
+
+// MakeHasher returns a new Hasher instance.
+func MakeHasher() Hasher {
+	return Hasher{make(map[types.Type]uint32)}
+}
+
+// Hash computes a hash value for the given type t such that
+// Identical(t, t') => Hash(t) == Hash(t').
+func (h Hasher) Hash(t types.Type) uint32 {
+	hash, ok := h.memo[t]
+	if !ok {
+		hash = h.hashFor(t)
+		h.memo[t] = hash
+	}
+	return hash
+}
+
+// hashString computes the Fowler–Noll–Vo hash of s.
+func hashString(s string) uint32 {
+	var h uint32
+	for i := 0; i < len(s); i++ {
+		h ^= uint32(s[i])
+		h *= 16777619
+	}
+	return h
+}
+
+// hashFor computes the hash of t.
+func (h Hasher) hashFor(t types.Type) uint32 {
+	// See Identical for rationale.
+	switch t := t.(type) {
+	case *types.Basic:
+		return uint32(t.Kind())
+
+	case *types.Array:
+		return 9043 + 2*uint32(t.Len()) + 3*h.Hash(t.Elem())
+
+	case *types.Slice:
+		return 9049 + 2*h.Hash(t.Elem())
+
+	case *types.Struct:
+		var hash uint32 = 9059
+		for i, n := 0, t.NumFields(); i < n; i++ {
+			f := t.Field(i)
+			if f.Anonymous() {
+				hash += 8861
+			}
+			hash += hashString(t.Tag(i))
+			hash += hashString(f.Name()) // (ignore f.Pkg)
+			hash += h.Hash(f.Type())
+		}
+		return hash
+
+	case *types.Pointer:
+		return 9067 + 2*h.Hash(t.Elem())
+
+	case *types.Signature:
+		var hash uint32 = 9091
+		if t.Variadic() {
+			hash *= 8863
+		}
+		return hash + 3*h.hashTuple(t.Params()) + 5*h.hashTuple(t.Results())
+
+	case *types.Interface:
+		var hash uint32 = 9103
+		for i, n := 0, t.NumMethods(); i < n; i++ {
+			// See go/types.identicalMethods for rationale.
+			// Method order is not significant.
+			// Ignore m.Pkg().
+			m := t.Method(i)
+			hash += 3*hashString(m.Name()) + 5*h.Hash(m.Type())
+		}
+		return hash
+
+	case *types.Map:
+		return 9109 + 2*h.Hash(t.Key()) + 3*h.Hash(t.Elem())
+
+	case *types.Chan:
+		return 9127 + 2*uint32(t.Dir()) + 3*h.Hash(t.Elem())
+
+	case *types.Named:
+		// Not safe with a copying GC; objects may move.
+		return uint32(reflect.ValueOf(t.Obj()).Pointer())
+
+	case *types.Tuple:
+		return h.hashTuple(t)
+	}
+	panic(t)
+}
+
+func (h Hasher) hashTuple(tuple *types.Tuple) uint32 {
+	// See go/types.identicalTypes for rationale.
+	n := tuple.Len()
+	var hash uint32 = 9137 + 2*uint32(n)
+	for i := 0; i < n; i++ {
+		hash += 3 * h.Hash(tuple.At(i).Type())
+	}
+	return hash
+}

vendor/golang.org/x/tools/go/types/typeutil/methodsetcache.go

@@ -0,0 +1,72 @@
+// Copyright 2014 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.
+
+// This file implements a cache of method sets.
+
+package typeutil
+
+import (
+	"go/types"
+	"sync"
+)
+
+// A MethodSetCache records the method set of each type T for which
+// MethodSet(T) is called so that repeat queries are fast.
+// The zero value is a ready-to-use cache instance.
+type MethodSetCache struct {
+	mu     sync.Mutex
+	named  map[*types.Named]struct{ value, pointer *types.MethodSet } // method sets for named N and *N
+	others map[types.Type]*types.MethodSet                            // all other types
+}
+
+// MethodSet returns the method set of type T.  It is thread-safe.
+//
+// If cache is nil, this function is equivalent to types.NewMethodSet(T).
+// Utility functions can thus expose an optional *MethodSetCache
+// parameter to clients that care about performance.
+//
+func (cache *MethodSetCache) MethodSet(T types.Type) *types.MethodSet {
+	if cache == nil {
+		return types.NewMethodSet(T)
+	}
+	cache.mu.Lock()
+	defer cache.mu.Unlock()
+
+	switch T := T.(type) {
+	case *types.Named:
+		return cache.lookupNamed(T).value
+
+	case *types.Pointer:
+		if N, ok := T.Elem().(*types.Named); ok {
+			return cache.lookupNamed(N).pointer
+		}
+	}
+
+	// all other types
+	// (The map uses pointer equivalence, not type identity.)
+	mset := cache.others[T]
+	if mset == nil {
+		mset = types.NewMethodSet(T)
+		if cache.others == nil {
+			cache.others = make(map[types.Type]*types.MethodSet)
+		}
+		cache.others[T] = mset
+	}
+	return mset
+}
+
+func (cache *MethodSetCache) lookupNamed(named *types.Named) struct{ value, pointer *types.MethodSet } {
+	if cache.named == nil {
+		cache.named = make(map[*types.Named]struct{ value, pointer *types.MethodSet })
+	}
+	// Avoid recomputing mset(*T) for each distinct Pointer
+	// instance whose underlying type is a named type.
+	msets, ok := cache.named[named]
+	if !ok {
+		msets.value = types.NewMethodSet(named)
+		msets.pointer = types.NewMethodSet(types.NewPointer(named))
+		cache.named[named] = msets
+	}
+	return msets
+}

vendor/golang.org/x/tools/go/types/typeutil/ui.go

@@ -0,0 +1,52 @@
+// Copyright 2014 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 typeutil
+
+// This file defines utilities for user interfaces that display types.
+
+import "go/types"
+
+// IntuitiveMethodSet returns the intuitive method set of a type T,
+// which is the set of methods you can call on an addressable value of
+// that type.
+//
+// The result always contains MethodSet(T), and is exactly MethodSet(T)
+// for interface types and for pointer-to-concrete types.
+// For all other concrete types T, the result additionally
+// contains each method belonging to *T if there is no identically
+// named method on T itself.
+//
+// This corresponds to user intuition about method sets;
+// this function is intended only for user interfaces.
+//
+// The order of the result is as for types.MethodSet(T).
+//
+func IntuitiveMethodSet(T types.Type, msets *MethodSetCache) []*types.Selection {
+	isPointerToConcrete := func(T types.Type) bool {
+		ptr, ok := T.(*types.Pointer)
+		return ok && !types.IsInterface(ptr.Elem())
+	}
+
+	var result []*types.Selection
+	mset := msets.MethodSet(T)
+	if types.IsInterface(T) || isPointerToConcrete(T) {
+		for i, n := 0, mset.Len(); i < n; i++ {
+			result = append(result, mset.At(i))
+		}
+	} else {
+		// T is some other concrete type.
+		// Report methods of T and *T, preferring those of T.
+		pmset := msets.MethodSet(types.NewPointer(T))
+		for i, n := 0, pmset.Len(); i < n; i++ {
+			meth := pmset.At(i)
+			if m := mset.Lookup(meth.Obj().Pkg(), meth.Obj().Name()); m != nil {
+				meth = m
+			}
+			result = append(result, meth)
+		}
+
+	}
+	return result
+}

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

@@ -13,11 +13,13 @@ import (
 	"bytes"
 	"fmt"
 	"go/ast"
+	"go/build"
 	"go/format"
 	"go/parser"
 	"go/printer"
 	"go/token"
 	"io"
+	"io/ioutil"
 	"regexp"
 	"strconv"
 	"strings"
@@ -44,9 +46,21 @@ type Options struct {
 // so it is important that filename be accurate.
 // To process data ``as if'' it were in filename, pass the data as a non-nil src.
 func Process(filename string, src []byte, opt *Options) ([]byte, error) {
+	env := &fixEnv{GOPATH: build.Default.GOPATH, GOROOT: build.Default.GOROOT}
+	return process(filename, src, opt, env)
+}
+
+func process(filename string, src []byte, opt *Options, env *fixEnv) ([]byte, error) {
 	if opt == nil {
 		opt = &Options{Comments: true, TabIndent: true, TabWidth: 8}
 	}
+	if src == nil {
+		b, err := ioutil.ReadFile(filename)
+		if err != nil {
+			return nil, err
+		}
+		src = b
+	}
 
 	fileSet := token.NewFileSet()
 	file, adjust, err := parse(fileSet, filename, src, opt)
@@ -55,15 +69,13 @@ func Process(filename string, src []byte, opt *Options) ([]byte, error) {
 	}
 
 	if !opt.FormatOnly {
-		_, err = fixImports(fileSet, file, filename)
-		if err != nil {
+		if err := fixImports(fileSet, file, filename, env); err != nil {
 			return nil, err
 		}
 	}
 
 	sortImports(fileSet, file)
 	imps := astutil.Imports(fileSet, file)
-
 	var spacesBefore []string // import paths we need spaces before
 	for _, impSection := range imps {
 		// Within each block of contiguous imports, see if any
@@ -98,7 +110,10 @@ func Process(filename string, src []byte, opt *Options) ([]byte, error) {
 		out = adjust(src, out)
 	}
 	if len(spacesBefore) > 0 {
-		out = addImportSpaces(bytes.NewReader(out), spacesBefore)
+		out, err = addImportSpaces(bytes.NewReader(out), spacesBefore)
+		if err != nil {
+			return nil, err
+		}
 	}
 
 	out, err = format.Source(out)
@@ -133,11 +148,18 @@ func parse(fset *token.FileSet, filename string, src []byte, opt *Options) (*ast
 
 	// If this is a declaration list, make it a source file
 	// by inserting a package clause.
-	// Insert using a ;, not a newline, so that the line numbers
-	// in psrc match the ones in src.
-	psrc := append([]byte("package main;"), src...)
+	// Insert using a ;, not a newline, so that parse errors are on
+	// the correct line.
+	const prefix = "package main;"
+	psrc := append([]byte(prefix), src...)
 	file, err = parser.ParseFile(fset, filename, psrc, parserMode)
 	if err == nil {
+		// Gofmt will turn the ; into a \n.
+		// Do that ourselves now and update the file contents,
+		// so that positions and line numbers are correct going forward.
+		psrc[len(prefix)-1] = '\n'
+		fset.File(file.Package).SetLinesForContent(psrc)
+
 		// If a main function exists, we will assume this is a main
 		// package and leave the file.
 		if containsMainFunc(file) {
@@ -146,8 +168,7 @@ func parse(fset *token.FileSet, filename string, src []byte, opt *Options) (*ast
 
 		adjust := func(orig, src []byte) []byte {
 			// Remove the package clause.
-			// Gofmt has turned the ; into a \n.
-			src = src[len("package main\n"):]
+			src = src[len(prefix):]
 			return matchSpace(orig, src)
 		}
 		return file, adjust, nil
@@ -256,13 +277,18 @@ func matchSpace(orig []byte, src []byte) []byte {
 
 var impLine = regexp.MustCompile(`^\s+(?:[\w\.]+\s+)?"(.+)"`)
 
-func addImportSpaces(r io.Reader, breaks []string) []byte {
+func addImportSpaces(r io.Reader, breaks []string) ([]byte, error) {
 	var out bytes.Buffer
-	sc := bufio.NewScanner(r)
+	in := bufio.NewReader(r)
 	inImports := false
 	done := false
-	for sc.Scan() {
-		s := sc.Text()
+	for {
+		s, err := in.ReadString('\n')
+		if err == io.EOF {
+			break
+		} else if err != nil {
+			return nil, err
+		}
 
 		if !inImports && !done && strings.HasPrefix(s, "import") {
 			inImports = true
@@ -283,7 +309,7 @@ func addImportSpaces(r io.Reader, breaks []string) []byte {
 			}
 		}
 
-		fmt.Fprintln(&out, s)
+		fmt.Fprint(&out, s)
 	}
-	return out.Bytes()
+	return out.Bytes(), nil
 }

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

@@ -14,9 +14,10 @@ import (
 	"io/ioutil"
 	"log"
 	"os"
-	"path"
+	"os/exec"
 	"path/filepath"
 	"regexp"
+	"runtime"
 	"sort"
 	"strings"
 )
@@ -30,11 +31,13 @@ func mustOpen(name string) io.Reader {
 }
 
 func api(base string) string {
-	return filepath.Join(os.Getenv("GOROOT"), "api", base)
+	return filepath.Join(runtime.GOROOT(), "api", base)
 }
 
 var sym = regexp.MustCompile(`^pkg (\S+).*?, (?:var|func|type|const) ([A-Z]\w*)`)
 
+var unsafeSyms = map[string]bool{"Alignof": true, "ArbitraryType": true, "Offsetof": true, "Pointer": true, "Sizeof": true}
+
 func main() {
 	var buf bytes.Buffer
 	outf := func(format string, args ...interface{}) {
@@ -42,7 +45,7 @@ func main() {
 	}
 	outf("// Code generated by mkstdlib.go. DO NOT EDIT.\n\n")
 	outf("package imports\n")
-	outf("var stdlib = map[string]string{\n")
+	outf("var stdlib = map[string]map[string]bool{\n")
 	f := io.MultiReader(
 		mustOpen(api("go1.txt")),
 		mustOpen(api("go1.1.txt")),
@@ -53,11 +56,22 @@ func main() {
 		mustOpen(api("go1.6.txt")),
 		mustOpen(api("go1.7.txt")),
 		mustOpen(api("go1.8.txt")),
+		mustOpen(api("go1.9.txt")),
+		mustOpen(api("go1.10.txt")),
+		mustOpen(api("go1.11.txt")),
+		mustOpen(api("go1.12.txt")),
+
+		// The API of the syscall/js package needs to be computed explicitly,
+		// because it's not included in the GOROOT/api/go1.*.txt files at this time.
+		syscallJSAPI(),
 	)
 	sc := bufio.NewScanner(f)
-	fullImport := map[string]string{} // "zip.NewReader" => "archive/zip"
-	ambiguous := map[string]bool{}
-	var keys []string
+
+	pkgs := map[string]map[string]bool{
+		"unsafe": unsafeSyms,
+	}
+	paths := []string{"unsafe"}
+
 	for sc.Scan() {
 		l := sc.Text()
 		has := func(v string) bool { return strings.Contains(l, v) }
@@ -65,32 +79,31 @@ func main() {
 			continue
 		}
 		if m := sym.FindStringSubmatch(l); m != nil {
-			full := m[1]
-			key := path.Base(full) + "." + m[2]
-			if exist, ok := fullImport[key]; ok {
-				if exist != full {
-					ambiguous[key] = true
-				}
-			} else {
-				fullImport[key] = full
-				keys = append(keys, key)
+			path, sym := m[1], m[2]
+
+			if _, ok := pkgs[path]; !ok {
+				pkgs[path] = map[string]bool{}
+				paths = append(paths, path)
 			}
+			pkgs[path][sym] = true
 		}
 	}
 	if err := sc.Err(); err != nil {
 		log.Fatal(err)
 	}
-	sort.Strings(keys)
-	for _, key := range keys {
-		if ambiguous[key] {
-			outf("\t// %q is ambiguous\n", key)
-		} else {
-			outf("\t%q: %q,\n", key, fullImport[key])
+	sort.Strings(paths)
+	for _, path := range paths {
+		outf("\t%q: map[string]bool{\n", path)
+		pkg := pkgs[path]
+		var syms []string
+		for sym := range pkg {
+			syms = append(syms, sym)
 		}
-	}
-	outf("\n")
-	for _, sym := range [...]string{"Alignof", "ArbitraryType", "Offsetof", "Pointer", "Sizeof"} {
-		outf("\t%q: %q,\n", "unsafe."+sym, "unsafe")
+		sort.Strings(syms)
+		for _, sym := range syms {
+			outf("\t\t%q: true,\n", sym)
+		}
+		outf("},\n")
 	}
 	outf("}\n")
 	fmtbuf, err := format.Source(buf.Bytes())
@@ -102,3 +115,18 @@ func main() {
 		log.Fatal(err)
 	}
 }
+
+// syscallJSAPI returns the API of the syscall/js package.
+// It's computed from the contents of $(go env GOROOT)/src/syscall/js.
+func syscallJSAPI() io.Reader {
+	var exeSuffix string
+	if runtime.GOOS == "windows" {
+		exeSuffix = ".exe"
+	}
+	cmd := exec.Command("go"+exeSuffix, "run", "cmd/api", "-contexts", "js-wasm", "syscall/js")
+	out, err := cmd.Output()
+	if err != nil {
+		log.Fatalln(err)
+	}
+	return bytes.NewReader(out)
+}

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

@@ -0,0 +1,355 @@
+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
+
+	initialized   bool
+	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.initialized {
+		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
+	})
+
+	r.initialized = true
+	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},
+	}
+	if r.main != nil {
+		roots = append(roots, gopathwalk.Root{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/imports/sortimports.go

@@ -167,15 +167,33 @@ func sortSpecs(fset *token.FileSet, f *ast.File, specs []ast.Spec) []ast.Spec {
 		}
 		s.Path.ValuePos = pos[i].Start
 		s.EndPos = pos[i].End
+		nextSpecPos := pos[i].End
+
 		for _, g := range importComment[s] {
 			for _, c := range g.List {
 				c.Slash = pos[i].End
+				nextSpecPos = c.End()
 			}
 		}
+		if i < len(specs)-1 {
+			pos[i+1].Start = nextSpecPos
+			pos[i+1].End = nextSpecPos
+		}
 	}
 
 	sort.Sort(byCommentPos(comments))
 
+	// Fixup comments can insert blank lines, because import specs are on different lines.
+	// We remove those blank lines here by merging import spec to the first import spec line.
+	firstSpecLine := fset.Position(specs[0].Pos()).Line
+	for _, s := range specs[1:] {
+		p := s.Pos()
+		line := fset.File(p).Line(p)
+		for previousLine := line - 1; previousLine >= firstSpecLine; {
+			fset.File(p).MergeLine(previousLine)
+			previousLine--
+		}
+	}
 	return specs
 }
 

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

@@ -2,17 +2,9 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// A faster implementation of filepath.Walk.
-//
-// filepath.Walk's design necessarily calls os.Lstat on each file,
-// even if the caller needs less info. And goimports only need to know
-// the type of each file. The kernel interface provides the type in
-// the Readdir call but the standard library ignored it.
-// fastwalk_unix.go contains a fork of the syscall routines.
-//
-// See golang.org/issue/16399
-
-package imports
+// Package fastwalk provides a faster version of filepath.Walk for file system
+// scanning tools.
+package fastwalk
 
 import (
 	"errors"
@@ -22,10 +14,27 @@ import (
 	"sync"
 )
 
-// traverseLink is a sentinel error for fastWalk, similar to filepath.SkipDir.
-var traverseLink = errors.New("traverse symlink, assuming target is a directory")
+// TraverseLink is used as a return value from WalkFuncs to indicate that the
+// symlink named in the call may be traversed.
+var TraverseLink = errors.New("fastwalk: traverse symlink, assuming target is a directory")
 
-// fastWalk walks the file tree rooted at root, calling walkFn for
+// SkipFiles is a used as a return value from WalkFuncs to indicate that the
+// callback should not be called for any other files in the current directory.
+// Child directories will still be traversed.
+var SkipFiles = errors.New("fastwalk: skip remaining files in directory")
+
+// Walk is a faster implementation of filepath.Walk.
+//
+// filepath.Walk's design necessarily calls os.Lstat on each file,
+// even if the caller needs less info.
+// Many tools need only the type of each file.
+// On some platforms, this information is provided directly by the readdir
+// system call, avoiding the need to stat each file individually.
+// fastwalk_unix.go contains a fork of the syscall routines.
+//
+// See golang.org/issue/16399
+//
+// Walk walks the file tree rooted at root, calling walkFn for
 // each file or directory in the tree, including root.
 //
 // If fastWalk returns filepath.SkipDir, the directory is skipped.
@@ -36,10 +45,10 @@ var traverseLink = errors.New("traverse symlink, assuming target is a directory"
 //     any permission bits.
 //   * multiple goroutines stat the filesystem concurrently. The provided
 //     walkFn must be safe for concurrent use.
-//   * fastWalk can follow symlinks if walkFn returns the traverseLink
+//   * fastWalk can follow symlinks if walkFn returns the TraverseLink
 //     sentinel error. It is the walkFn's responsibility to prevent
 //     fastWalk from going into symlink cycles.
-func fastWalk(root string, walkFn func(path string, typ os.FileMode) error) error {
+func Walk(root string, walkFn func(path string, typ os.FileMode) error) error {
 	// TODO(bradfitz): make numWorkers configurable? We used a
 	// minimum of 4 to give the kernel more info about multiple
 	// things we want, in hopes its I/O scheduling can take
@@ -158,7 +167,7 @@ func (w *walker) onDirEnt(dirName, baseName string, typ os.FileMode) error {
 
 	err := w.fn(joined, typ)
 	if typ == os.ModeSymlink {
-		if err == traverseLink {
+		if err == TraverseLink {
 			// Set callbackDone so we don't call it twice for both the
 			// symlink-as-symlink and the symlink-as-directory later:
 			w.enqueue(walkItem{dir: joined, callbackDone: true})

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_fileno.go

@@ -4,7 +4,7 @@
 
 // +build freebsd openbsd netbsd
 
-package imports
+package fastwalk
 
 import "syscall"
 

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_ino.go

@@ -2,9 +2,10 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,!appengine darwin
+// +build linux darwin
+// +build !appengine
 
-package imports
+package fastwalk
 
 import "syscall"
 

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_bsd.go

@@ -0,0 +1,13 @@
+// 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.
+
+// +build darwin freebsd openbsd netbsd
+
+package fastwalk
+
+import "syscall"
+
+func direntNamlen(dirent *syscall.Dirent) uint64 {
+	return uint64(dirent.Namlen)
+}

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_dirent_namlen_linux.go

@@ -0,0 +1,29 @@
+// 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.
+
+// +build linux
+// +build !appengine
+
+package fastwalk
+
+import (
+	"bytes"
+	"syscall"
+	"unsafe"
+)
+
+func direntNamlen(dirent *syscall.Dirent) uint64 {
+	const fixedHdr = uint16(unsafe.Offsetof(syscall.Dirent{}.Name))
+	nameBuf := (*[unsafe.Sizeof(dirent.Name)]byte)(unsafe.Pointer(&dirent.Name[0]))
+	const nameBufLen = uint16(len(nameBuf))
+	limit := dirent.Reclen - fixedHdr
+	if limit > nameBufLen {
+		limit = nameBufLen
+	}
+	nameLen := bytes.IndexByte(nameBuf[:limit], 0)
+	if nameLen < 0 {
+		panic("failed to find terminating 0 byte in dirent")
+	}
+	return uint64(nameLen)
+}

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_portable.go

@@ -4,7 +4,7 @@
 
 // +build appengine !linux,!darwin,!freebsd,!openbsd,!netbsd
 
-package imports
+package fastwalk
 
 import (
 	"io/ioutil"
@@ -20,8 +20,16 @@ func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) e
 	if err != nil {
 		return err
 	}
+	skipFiles := false
 	for _, fi := range fis {
+		if fi.Mode().IsRegular() && skipFiles {
+			continue
+		}
 		if err := fn(dirName, fi.Name(), fi.Mode()&os.ModeType); err != nil {
+			if err == SkipFiles {
+				skipFiles = true
+				continue
+			}
 			return err
 		}
 	}

vendor/golang.org/x/tools/internal/fastwalk/fastwalk_unix.go

@@ -2,12 +2,12 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build linux,!appengine darwin freebsd openbsd netbsd
+// +build linux darwin freebsd openbsd netbsd
+// +build !appengine
 
-package imports
+package fastwalk
 
 import (
-	"bytes"
 	"fmt"
 	"os"
 	"syscall"
@@ -23,7 +23,7 @@ const unknownFileMode os.FileMode = os.ModeNamedPipe | os.ModeSocket | os.ModeDe
 func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) error) error {
 	fd, err := syscall.Open(dirName, 0, 0)
 	if err != nil {
-		return err
+		return &os.PathError{Op: "open", Path: dirName, Err: err}
 	}
 	defer syscall.Close(fd)
 
@@ -31,6 +31,7 @@ func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) e
 	buf := make([]byte, blockSize) // stack-allocated; doesn't escape
 	bufp := 0                      // starting read position in buf
 	nbuf := 0                      // end valid data in buf
+	skipFiles := false
 	for {
 		if bufp >= nbuf {
 			bufp = 0
@@ -61,7 +62,14 @@ func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) e
 			}
 			typ = fi.Mode() & os.ModeType
 		}
+		if skipFiles && typ.IsRegular() {
+			continue
+		}
 		if err := fn(dirName, name, typ); err != nil {
+			if err == SkipFiles {
+				skipFiles = true
+				continue
+			}
 			return err
 		}
 	}
@@ -105,10 +113,7 @@ func parseDirEnt(buf []byte) (consumed int, name string, typ os.FileMode) {
 	}
 
 	nameBuf := (*[unsafe.Sizeof(dirent.Name)]byte)(unsafe.Pointer(&dirent.Name[0]))
-	nameLen := bytes.IndexByte(nameBuf[:], 0)
-	if nameLen < 0 {
-		panic("failed to find terminating 0 byte in dirent")
-	}
+	nameLen := direntNamlen(dirent)
 
 	// Special cases for common things:
 	if nameLen == 1 && nameBuf[0] == '.' {

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

@@ -0,0 +1,250 @@
+// 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 gopathwalk is like filepath.Walk but specialized for finding Go
+// packages, particularly in $GOPATH and $GOROOT.
+package gopathwalk
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"go/build"
+	"io/ioutil"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"golang.org/x/tools/internal/fastwalk"
+)
+
+// Options controls the behavior of a Walk call.
+type Options struct {
+	Debug          bool // Enable debug logging
+	ModulesEnabled bool // Search module caches. Also disables legacy goimports ignore rules.
+}
+
+// RootType indicates the type of a Root.
+type RootType int
+
+const (
+	RootUnknown RootType = iota
+	RootGOROOT
+	RootGOPATH
+	RootCurrentModule
+	RootModuleCache
+	RootOther
+)
+
+// A Root is a starting point for a Walk.
+type Root struct {
+	Path string
+	Type RootType
+}
+
+// SrcDirsRoots returns the roots from build.Default.SrcDirs(). Not modules-compatible.
+func SrcDirsRoots(ctx *build.Context) []Root {
+	var roots []Root
+	roots = append(roots, Root{filepath.Join(ctx.GOROOT, "src"), RootGOROOT})
+	for _, p := range filepath.SplitList(ctx.GOPATH) {
+		roots = append(roots, Root{filepath.Join(p, "src"), RootGOPATH})
+	}
+	return roots
+}
+
+// Walk walks Go source directories ($GOROOT, $GOPATH, etc) to find packages.
+// For each package found, add will be called (concurrently) with the absolute
+// paths of the containing source directory and the package directory.
+// add will be called concurrently.
+func Walk(roots []Root, add func(root Root, dir string), opts Options) {
+	for _, root := range roots {
+		walkDir(root, add, opts)
+	}
+}
+
+func walkDir(root Root, add func(Root, string), opts Options) {
+	if _, err := os.Stat(root.Path); os.IsNotExist(err) {
+		if opts.Debug {
+			log.Printf("skipping nonexistant directory: %v", root.Path)
+		}
+		return
+	}
+	if opts.Debug {
+		log.Printf("scanning %s", root.Path)
+	}
+	w := &walker{
+		root: root,
+		add:  add,
+		opts: opts,
+	}
+	w.init()
+	if err := fastwalk.Walk(root.Path, w.walk); err != nil {
+		log.Printf("gopathwalk: scanning directory %v: %v", root.Path, err)
+	}
+
+	if opts.Debug {
+		log.Printf("scanned %s", root.Path)
+	}
+}
+
+// walker is the callback for fastwalk.Walk.
+type walker struct {
+	root Root               // The source directory to scan.
+	add  func(Root, string) // The callback that will be invoked for every possible Go package dir.
+	opts Options            // Options passed to Walk by the user.
+
+	ignoredDirs []os.FileInfo // The ignored directories, loaded from .goimportsignore files.
+}
+
+// init initializes the walker based on its Options.
+func (w *walker) init() {
+	var ignoredPaths []string
+	if w.root.Type == RootModuleCache {
+		ignoredPaths = []string{"cache"}
+	}
+	if !w.opts.ModulesEnabled && w.root.Type == RootGOPATH {
+		ignoredPaths = w.getIgnoredDirs(w.root.Path)
+		ignoredPaths = append(ignoredPaths, "v", "mod")
+	}
+
+	for _, p := range ignoredPaths {
+		full := filepath.Join(w.root.Path, p)
+		if fi, err := os.Stat(full); err == nil {
+			w.ignoredDirs = append(w.ignoredDirs, fi)
+			if w.opts.Debug {
+				log.Printf("Directory added to ignore list: %s", full)
+			}
+		} else if w.opts.Debug {
+			log.Printf("Error statting ignored directory: %v", err)
+		}
+	}
+}
+
+// getIgnoredDirs reads an optional config file at <path>/.goimportsignore
+// of relative directories to ignore when scanning for go files.
+// The provided path is one of the $GOPATH entries with "src" appended.
+func (w *walker) getIgnoredDirs(path string) []string {
+	file := filepath.Join(path, ".goimportsignore")
+	slurp, err := ioutil.ReadFile(file)
+	if w.opts.Debug {
+		if err != nil {
+			log.Print(err)
+		} else {
+			log.Printf("Read %s", file)
+		}
+	}
+	if err != nil {
+		return nil
+	}
+
+	var ignoredDirs []string
+	bs := bufio.NewScanner(bytes.NewReader(slurp))
+	for bs.Scan() {
+		line := strings.TrimSpace(bs.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		ignoredDirs = append(ignoredDirs, line)
+	}
+	return ignoredDirs
+}
+
+func (w *walker) shouldSkipDir(fi os.FileInfo) bool {
+	for _, ignoredDir := range w.ignoredDirs {
+		if os.SameFile(fi, ignoredDir) {
+			return true
+		}
+	}
+	return false
+}
+
+func (w *walker) walk(path string, typ os.FileMode) error {
+	dir := filepath.Dir(path)
+	if typ.IsRegular() {
+		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
+		}
+		if !strings.HasSuffix(path, ".go") {
+			return nil
+		}
+
+		w.add(w.root, dir)
+		return fastwalk.SkipFiles
+	}
+	if typ == os.ModeDir {
+		base := filepath.Base(path)
+		if base == "" || base[0] == '.' || base[0] == '_' ||
+			base == "testdata" ||
+			(w.root.Type == RootGOROOT && w.opts.ModulesEnabled && base == "vendor") ||
+			(!w.opts.ModulesEnabled && base == "node_modules") {
+			return filepath.SkipDir
+		}
+		fi, err := os.Lstat(path)
+		if err == nil && w.shouldSkipDir(fi) {
+			return filepath.SkipDir
+		}
+		return nil
+	}
+	if typ == os.ModeSymlink {
+		base := filepath.Base(path)
+		if strings.HasPrefix(base, ".#") {
+			// Emacs noise.
+			return nil
+		}
+		fi, err := os.Lstat(path)
+		if err != nil {
+			// Just ignore it.
+			return nil
+		}
+		if w.shouldTraverse(dir, fi) {
+			return fastwalk.TraverseLink
+		}
+	}
+	return nil
+}
+
+// shouldTraverse reports whether the symlink fi, found in dir,
+// should be followed.  It makes sure symlinks were never visited
+// before to avoid symlink loops.
+func (w *walker) shouldTraverse(dir string, fi os.FileInfo) bool {
+	path := filepath.Join(dir, fi.Name())
+	target, err := filepath.EvalSymlinks(path)
+	if err != nil {
+		return false
+	}
+	ts, err := os.Stat(target)
+	if err != nil {
+		fmt.Fprintln(os.Stderr, err)
+		return false
+	}
+	if !ts.IsDir() {
+		return false
+	}
+	if w.shouldSkipDir(ts) {
+		return false
+	}
+	// Check for symlink loops by statting each directory component
+	// and seeing if any are the same file as ts.
+	for {
+		parent := filepath.Dir(path)
+		if parent == path {
+			// Made it to the root without seeing a cycle.
+			// Use this symlink.
+			return true
+		}
+		parentInfo, err := os.Stat(parent)
+		if err != nil {
+			return false
+		}
+		if os.SameFile(ts, parentInfo) {
+			// Cycle. Don't traverse.
+			return false
+		}
+		path = parent
+	}
+
+}

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
+}

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

@@ -0,0 +1,388 @@
+// 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 semver implements comparison of semantic version strings.
+// In this package, semantic version strings must begin with a leading "v",
+// as in "v1.0.0".
+//
+// The general form of a semantic version string accepted by this package is
+//
+//	vMAJOR[.MINOR[.PATCH[-PRERELEASE][+BUILD]]]
+//
+// where square brackets indicate optional parts of the syntax;
+// MAJOR, MINOR, and PATCH are decimal integers without extra leading zeros;
+// PRERELEASE and BUILD are each a series of non-empty dot-separated identifiers
+// using only alphanumeric characters and hyphens; and
+// all-numeric PRERELEASE identifiers must not have leading zeros.
+//
+// This package follows Semantic Versioning 2.0.0 (see semver.org)
+// with two exceptions. First, it requires the "v" prefix. Second, it recognizes
+// vMAJOR and vMAJOR.MINOR (with no prerelease or build suffixes)
+// as shorthands for vMAJOR.0.0 and vMAJOR.MINOR.0.
+package semver
+
+// parsed returns the parsed form of a semantic version string.
+type parsed struct {
+	major      string
+	minor      string
+	patch      string
+	short      string
+	prerelease string
+	build      string
+	err        string
+}
+
+// IsValid reports whether v is a valid semantic version string.
+func IsValid(v string) bool {
+	_, ok := parse(v)
+	return ok
+}
+
+// Canonical returns the canonical formatting of the semantic version v.
+// It fills in any missing .MINOR or .PATCH and discards build metadata.
+// Two semantic versions compare equal only if their canonical formattings
+// are identical strings.
+// The canonical invalid semantic version is the empty string.
+func Canonical(v string) string {
+	p, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	if p.build != "" {
+		return v[:len(v)-len(p.build)]
+	}
+	if p.short != "" {
+		return v + p.short
+	}
+	return v
+}
+
+// Major returns the major version prefix of the semantic version v.
+// For example, Major("v2.1.0") == "v2".
+// If v is an invalid semantic version string, Major returns the empty string.
+func Major(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	return v[:1+len(pv.major)]
+}
+
+// MajorMinor returns the major.minor version prefix of the semantic version v.
+// For example, MajorMinor("v2.1.0") == "v2.1".
+// If v is an invalid semantic version string, MajorMinor returns the empty string.
+func MajorMinor(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	i := 1 + len(pv.major)
+	if j := i + 1 + len(pv.minor); j <= len(v) && v[i] == '.' && v[i+1:j] == pv.minor {
+		return v[:j]
+	}
+	return v[:i] + "." + pv.minor
+}
+
+// Prerelease returns the prerelease suffix of the semantic version v.
+// For example, Prerelease("v2.1.0-pre+meta") == "-pre".
+// If v is an invalid semantic version string, Prerelease returns the empty string.
+func Prerelease(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	return pv.prerelease
+}
+
+// Build returns the build suffix of the semantic version v.
+// For example, Build("v2.1.0+meta") == "+meta".
+// If v is an invalid semantic version string, Build returns the empty string.
+func Build(v string) string {
+	pv, ok := parse(v)
+	if !ok {
+		return ""
+	}
+	return pv.build
+}
+
+// Compare returns an integer comparing two versions according to
+// according to semantic version precedence.
+// The result will be 0 if v == w, -1 if v < w, or +1 if v > w.
+//
+// An invalid semantic version string is considered less than a valid one.
+// All invalid semantic version strings compare equal to each other.
+func Compare(v, w string) int {
+	pv, ok1 := parse(v)
+	pw, ok2 := parse(w)
+	if !ok1 && !ok2 {
+		return 0
+	}
+	if !ok1 {
+		return -1
+	}
+	if !ok2 {
+		return +1
+	}
+	if c := compareInt(pv.major, pw.major); c != 0 {
+		return c
+	}
+	if c := compareInt(pv.minor, pw.minor); c != 0 {
+		return c
+	}
+	if c := compareInt(pv.patch, pw.patch); c != 0 {
+		return c
+	}
+	return comparePrerelease(pv.prerelease, pw.prerelease)
+}
+
+// Max canonicalizes its arguments and then returns the version string
+// that compares greater.
+func Max(v, w string) string {
+	v = Canonical(v)
+	w = Canonical(w)
+	if Compare(v, w) > 0 {
+		return v
+	}
+	return w
+}
+
+func parse(v string) (p parsed, ok bool) {
+	if v == "" || v[0] != 'v' {
+		p.err = "missing v prefix"
+		return
+	}
+	p.major, v, ok = parseInt(v[1:])
+	if !ok {
+		p.err = "bad major version"
+		return
+	}
+	if v == "" {
+		p.minor = "0"
+		p.patch = "0"
+		p.short = ".0.0"
+		return
+	}
+	if v[0] != '.' {
+		p.err = "bad minor prefix"
+		ok = false
+		return
+	}
+	p.minor, v, ok = parseInt(v[1:])
+	if !ok {
+		p.err = "bad minor version"
+		return
+	}
+	if v == "" {
+		p.patch = "0"
+		p.short = ".0"
+		return
+	}
+	if v[0] != '.' {
+		p.err = "bad patch prefix"
+		ok = false
+		return
+	}
+	p.patch, v, ok = parseInt(v[1:])
+	if !ok {
+		p.err = "bad patch version"
+		return
+	}
+	if len(v) > 0 && v[0] == '-' {
+		p.prerelease, v, ok = parsePrerelease(v)
+		if !ok {
+			p.err = "bad prerelease"
+			return
+		}
+	}
+	if len(v) > 0 && v[0] == '+' {
+		p.build, v, ok = parseBuild(v)
+		if !ok {
+			p.err = "bad build"
+			return
+		}
+	}
+	if v != "" {
+		p.err = "junk on end"
+		ok = false
+		return
+	}
+	ok = true
+	return
+}
+
+func parseInt(v string) (t, rest string, ok bool) {
+	if v == "" {
+		return
+	}
+	if v[0] < '0' || '9' < v[0] {
+		return
+	}
+	i := 1
+	for i < len(v) && '0' <= v[i] && v[i] <= '9' {
+		i++
+	}
+	if v[0] == '0' && i != 1 {
+		return
+	}
+	return v[:i], v[i:], true
+}
+
+func parsePrerelease(v string) (t, rest string, ok bool) {
+	// "A pre-release version MAY be denoted by appending a hyphen and
+	// a series of dot separated identifiers immediately following the patch version.
+	// Identifiers MUST comprise only ASCII alphanumerics and hyphen [0-9A-Za-z-].
+	// Identifiers MUST NOT be empty. Numeric identifiers MUST NOT include leading zeroes."
+	if v == "" || v[0] != '-' {
+		return
+	}
+	i := 1
+	start := 1
+	for i < len(v) && v[i] != '+' {
+		if !isIdentChar(v[i]) && v[i] != '.' {
+			return
+		}
+		if v[i] == '.' {
+			if start == i || isBadNum(v[start:i]) {
+				return
+			}
+			start = i + 1
+		}
+		i++
+	}
+	if start == i || isBadNum(v[start:i]) {
+		return
+	}
+	return v[:i], v[i:], true
+}
+
+func parseBuild(v string) (t, rest string, ok bool) {
+	if v == "" || v[0] != '+' {
+		return
+	}
+	i := 1
+	start := 1
+	for i < len(v) {
+		if !isIdentChar(v[i]) {
+			return
+		}
+		if v[i] == '.' {
+			if start == i {
+				return
+			}
+			start = i + 1
+		}
+		i++
+	}
+	if start == i {
+		return
+	}
+	return v[:i], v[i:], true
+}
+
+func isIdentChar(c byte) bool {
+	return 'A' <= c && c <= 'Z' || 'a' <= c && c <= 'z' || '0' <= c && c <= '9' || c == '-'
+}
+
+func isBadNum(v string) bool {
+	i := 0
+	for i < len(v) && '0' <= v[i] && v[i] <= '9' {
+		i++
+	}
+	return i == len(v) && i > 1 && v[0] == '0'
+}
+
+func isNum(v string) bool {
+	i := 0
+	for i < len(v) && '0' <= v[i] && v[i] <= '9' {
+		i++
+	}
+	return i == len(v)
+}
+
+func compareInt(x, y string) int {
+	if x == y {
+		return 0
+	}
+	if len(x) < len(y) {
+		return -1
+	}
+	if len(x) > len(y) {
+		return +1
+	}
+	if x < y {
+		return -1
+	} else {
+		return +1
+	}
+}
+
+func comparePrerelease(x, y string) int {
+	// "When major, minor, and patch are equal, a pre-release version has
+	// lower precedence than a normal version.
+	// Example: 1.0.0-alpha < 1.0.0.
+	// Precedence for two pre-release versions with the same major, minor,
+	// and patch version MUST be determined by comparing each dot separated
+	// identifier from left to right until a difference is found as follows:
+	// identifiers consisting of only digits are compared numerically and
+	// identifiers with letters or hyphens are compared lexically in ASCII
+	// sort order. Numeric identifiers always have lower precedence than
+	// non-numeric identifiers. A larger set of pre-release fields has a
+	// higher precedence than a smaller set, if all of the preceding
+	// identifiers are equal.
+	// Example: 1.0.0-alpha < 1.0.0-alpha.1 < 1.0.0-alpha.beta <
+	// 1.0.0-beta < 1.0.0-beta.2 < 1.0.0-beta.11 < 1.0.0-rc.1 < 1.0.0."
+	if x == y {
+		return 0
+	}
+	if x == "" {
+		return +1
+	}
+	if y == "" {
+		return -1
+	}
+	for x != "" && y != "" {
+		x = x[1:] // skip - or .
+		y = y[1:] // skip - or .
+		var dx, dy string
+		dx, x = nextIdent(x)
+		dy, y = nextIdent(y)
+		if dx != dy {
+			ix := isNum(dx)
+			iy := isNum(dy)
+			if ix != iy {
+				if ix {
+					return -1
+				} else {
+					return +1
+				}
+			}
+			if ix {
+				if len(dx) < len(dy) {
+					return -1
+				}
+				if len(dx) > len(dy) {
+					return +1
+				}
+			}
+			if dx < dy {
+				return -1
+			} else {
+				return +1
+			}
+		}
+	}
+	if x == "" {
+		return -1
+	} else {
+		return +1
+	}
+}
+
+func nextIdent(x string) (dx, rest string) {
+	i := 0
+	for i < len(x) && x[i] != '.' {
+		i++
+	}
+	return x[:i], x[i:]
+}