Rename scripts to build and add revive command as a new build tool command (#10942)

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

7 files changed, 459 insertions, 599 deletions

diff --git a/vendor/golang.org/x/tools/go/ast/astutil/imports.go b/vendor/golang.org/x/tools/go/ast/astutil/imports.go
index 3e4b195368..2087ceec9c 100644
--- a/vendor/golang.org/x/tools/go/ast/astutil/imports.go
+++ b/vendor/golang.org/x/tools/go/ast/astutil/imports.go
@@ -275,9 +275,10 @@ func DeleteNamedImport(fset *token.FileSet, f *ast.File, name, path string) (del
 
 				// We deleted an entry but now there may be
 				// a blank line-sized hole where the import was.
-				if line-lastLine > 1 {
+				if line-lastLine > 1 || !gen.Rparen.IsValid() {
 					// There was a blank line immediately preceding the deleted import,
-					// so there's no need to close the hole.
+					// so there's no need to close the hole. The right parenthesis is
+					// invalid after AddImport to an import statement without parenthesis.
 					// Do nothing.
 				} else if line != fset.File(gen.Rparen).LineCount() {
 					// There was no blank line. Close the hole.
diff --git a/vendor/golang.org/x/tools/go/internal/cgo/cgo.go b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go
index 0f652ea6fb..5db8b30967 100644
--- a/vendor/golang.org/x/tools/go/internal/cgo/cgo.go
+++ b/vendor/golang.org/x/tools/go/internal/cgo/cgo.go
@@ -2,9 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-package cgo
-
-// This file handles cgo preprocessing of files containing `import "C"`.
+// Package cgo handles cgo preprocessing of files containing `import "C"`.
 //
 // DESIGN
 //
@@ -51,6 +49,8 @@ package cgo
 // its handling of function calls, analogous to the treatment of map
 // lookups in which y=m[k] and y,ok=m[k] are both legal.
 
+package cgo
+
 import (
 	"fmt"
 	"go/ast"
diff --git a/vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go b/vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go
index 9cf186605f..8dcd8bbb71 100644
--- a/vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go
+++ b/vendor/golang.org/x/tools/go/internal/gcimporter/gcimporter.go
@@ -344,7 +344,7 @@ func (p *parser) expectKeyword(keyword string) {
 
 // PackageId = string_lit .
 //
-func (p *parser) parsePackageId() string {
+func (p *parser) parsePackageID() string {
 	id, err := strconv.Unquote(p.expect(scanner.String))
 	if err != nil {
 		p.error(err)
@@ -384,7 +384,7 @@ func (p *parser) parseDotIdent() string {
 //
 func (p *parser) parseQualifiedName() (id, name string) {
 	p.expect('@')
-	id = p.parsePackageId()
+	id = p.parsePackageID()
 	p.expect('.')
 	// Per rev f280b8a485fd (10/2/2013), qualified names may be used for anonymous fields.
 	if p.tok == '?' {
@@ -696,7 +696,7 @@ func (p *parser) parseInterfaceType(parent *types.Package) types.Type {
 
 	// Complete requires the type's embedded interfaces to be fully defined,
 	// but we do not define any
-	return types.NewInterface(methods, nil).Complete()
+	return newInterface(methods, nil).Complete()
 }
 
 // ChanType = ( "chan" [ "<-" ] | "<-" "chan" ) Type .
@@ -785,7 +785,7 @@ func (p *parser) parseType(parent *types.Package) types.Type {
 func (p *parser) parseImportDecl() {
 	p.expectKeyword("import")
 	name := p.parsePackageName()
-	p.getPkg(p.parsePackageId(), name)
+	p.getPkg(p.parsePackageID(), name)
 }
 
 // int_lit = [ "+" | "-" ] { "0" ... "9" } .
diff --git a/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go b/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go
index db0c9a7ea6..5ee692d383 100644
--- a/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go
+++ b/vendor/golang.org/x/tools/go/internal/packagesdriver/sizes.go
@@ -11,11 +11,10 @@ import (
 	"encoding/json"
 	"fmt"
 	"go/types"
-	"log"
-	"os"
 	"os/exec"
 	"strings"
-	"time"
+
+	"golang.org/x/tools/internal/gocommand"
 )
 
 var debug = false
@@ -78,97 +77,42 @@ func GetSizes(ctx context.Context, buildFlags, env []string, dir string, usesExp
 }
 
 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, stderr, err := invokeGo(ctx, env, dir, usesExportData, args...)
+	inv := gocommand.Invocation{
+		Verb:       "list",
+		Args:       []string{"-f", "{{context.GOARCH}} {{context.Compiler}}", "--", "unsafe"},
+		Env:        env,
+		BuildFlags: buildFlags,
+		WorkingDir: dir,
+	}
+	stdout, stderr, friendlyErr, rawErr := inv.RunRaw(ctx)
 	var goarch, compiler string
-	if err != nil {
-		if strings.Contains(err.Error(), "cannot find main module") {
+	if rawErr != nil {
+		if strings.Contains(rawErr.Error(), "cannot find main module") {
 			// User's running outside of a module. All bets are off. Get GOARCH and guess compiler is gc.
 			// TODO(matloob): Is this a problem in practice?
-			envout, _, enverr := invokeGo(ctx, env, dir, usesExportData, "env", "GOARCH")
+			inv := gocommand.Invocation{
+				Verb:       "env",
+				Args:       []string{"GOARCH"},
+				Env:        env,
+				WorkingDir: dir,
+			}
+			envout, enverr := inv.Run(ctx)
 			if enverr != nil {
-				return nil, err
+				return nil, enverr
 			}
 			goarch = strings.TrimSpace(envout.String())
 			compiler = "gc"
 		} else {
-			return nil, err
+			return nil, friendlyErr
 		}
 	} else {
 		fields := strings.Fields(stdout.String())
 		if len(fields) < 2 {
-			return nil, fmt.Errorf("could not parse GOARCH and Go compiler in format \"<GOARCH> <compiler>\" from stdout of go command:\n%s\ndir: %s\nstdout: <<%s>>\nstderr: <<%s>>",
-				cmdDebugStr(env, args...), dir, stdout.String(), stderr.String())
+			return nil, fmt.Errorf("could not parse GOARCH and Go compiler in format \"<GOARCH> <compiler>\":\nstdout: <<%s>>\nstderr: <<%s>>",
+				stdout.String(), stderr.String())
 		}
 		goarch = fields[0]
 		compiler = fields[1]
 	}
 	return types.SizesFor(compiler, goarch), nil
 }
-
-// invokeGo returns the stdout and stderr of a go command invocation.
-func invokeGo(ctx context.Context, env []string, dir string, usesExportData bool, args ...string) (*bytes.Buffer, *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, 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, 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, stderr, 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)
-}
diff --git a/vendor/golang.org/x/tools/go/packages/golist.go b/vendor/golang.org/x/tools/go/packages/golist.go
index 9c895b3895..b4a13ef454 100644
--- a/vendor/golang.org/x/tools/go/packages/golist.go
+++ b/vendor/golang.org/x/tools/go/packages/golist.go
@@ -6,26 +6,25 @@ package packages
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"go/types"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"path"
 	"path/filepath"
 	"reflect"
-	"regexp"
+	"sort"
 	"strconv"
 	"strings"
 	"sync"
-	"time"
 	"unicode"
 
 	"golang.org/x/tools/go/internal/packagesdriver"
-	"golang.org/x/tools/internal/gopathwalk"
-	"golang.org/x/tools/internal/semver"
+	"golang.org/x/tools/internal/gocommand"
+	"golang.org/x/tools/internal/packagesinternal"
 )
 
 // debug controls verbose logging.
@@ -44,16 +43,21 @@ type responseDeduper struct {
 	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{}
+func newDeduper() *responseDeduper {
+	return &responseDeduper{
+		dr:           &driverResponse{},
+		seenRoots:    map[string]bool{},
+		seenPackages: map[string]*Package{},
+	}
+}
+
+// addAll fills in r with a driverResponse.
+func (r *responseDeduper) addAll(dr *driverResponse) {
 	for _, pkg := range dr.Packages {
-		r.seenPackages[pkg.ID] = pkg
+		r.addPackage(pkg)
 	}
 	for _, root := range dr.Roots {
-		r.seenRoots[root] = true
+		r.addRoot(root)
 	}
 }
 
@@ -73,25 +77,47 @@ func (r *responseDeduper) addRoot(id string) {
 	r.dr.Roots = append(r.dr.Roots, id)
 }
 
-// goInfo contains global information from the go tool.
-type goInfo struct {
-	rootDirs map[string]string
-	env      goEnv
+type golistState struct {
+	cfg *Config
+	ctx context.Context
+
+	envOnce    sync.Once
+	goEnvError error
+	goEnv      map[string]string
+
+	rootsOnce     sync.Once
+	rootDirsError error
+	rootDirs      map[string]string
+
+	// vendorDirs caches the (non)existence of vendor directories.
+	vendorDirs map[string]bool
 }
 
-type goEnv struct {
-	modulesOn bool
+// getEnv returns Go environment variables. Only specific variables are
+// populated -- computing all of them is slow.
+func (state *golistState) getEnv() (map[string]string, error) {
+	state.envOnce.Do(func() {
+		var b *bytes.Buffer
+		b, state.goEnvError = state.invokeGo("env", "-json", "GOMOD", "GOPATH")
+		if state.goEnvError != nil {
+			return
+		}
+
+		state.goEnv = make(map[string]string)
+		decoder := json.NewDecoder(b)
+		if state.goEnvError = decoder.Decode(&state.goEnv); state.goEnvError != nil {
+			return
+		}
+	})
+	return state.goEnv, state.goEnvError
 }
 
-func determineEnv(cfg *Config) goEnv {
-	buf, err := invokeGo(cfg, "env", "GOMOD")
+// mustGetEnv is a convenience function that can be used if getEnv has already succeeded.
+func (state *golistState) mustGetEnv() map[string]string {
+	env, err := state.getEnv()
 	if err != nil {
-		return goEnv{}
+		panic(fmt.Sprintf("mustGetEnv: %v", err))
 	}
-	gomod := bytes.TrimSpace(buf.Bytes())
-
-	env := goEnv{}
-	env.modulesOn = len(gomod) > 0
 	return env
 }
 
@@ -99,47 +125,38 @@ func determineEnv(cfg *Config) goEnv {
 // the build system package structure.
 // See driver for more details.
 func goListDriver(cfg *Config, patterns ...string) (*driverResponse, error) {
-	var sizes types.Sizes
+	// Make sure that any asynchronous go commands are killed when we return.
+	parentCtx := cfg.Context
+	if parentCtx == nil {
+		parentCtx = context.Background()
+	}
+	ctx, cancel := context.WithCancel(parentCtx)
+	defer cancel()
+
+	response := newDeduper()
+
+	// Fill in response.Sizes asynchronously if necessary.
 	var sizeserr error
 	var sizeswg sync.WaitGroup
 	if cfg.Mode&NeedTypesSizes != 0 || cfg.Mode&NeedTypes != 0 {
 		sizeswg.Add(1)
 		go func() {
-			sizes, sizeserr = getSizes(cfg)
+			var sizes types.Sizes
+			sizes, sizeserr = packagesdriver.GetSizesGolist(ctx, cfg.BuildFlags, cfg.Env, cfg.Dir, usesExportData(cfg))
+			// types.SizesFor always returns nil or a *types.StdSizes.
+			response.dr.Sizes, _ = sizes.(*types.StdSizes)
 			sizeswg.Done()
 		}()
 	}
-	defer sizeswg.Wait()
-
-	// start fetching rootDirs
-	var info goInfo
-	var rootDirsReady, envReady = make(chan struct{}), make(chan struct{})
-	go func() {
-		info.rootDirs = determineRootDirs(cfg)
-		close(rootDirsReady)
-	}()
-	go func() {
-		info.env = determineEnv(cfg)
-		close(envReady)
-	}()
-	getGoInfo := func() *goInfo {
-		<-rootDirsReady
-		<-envReady
-		return &info
-	}
-
-	// Ensure that we don't leak goroutines: Load is synchronous, so callers will
-	// not expect it to access the fields of cfg after the call returns.
-	defer getGoInfo()
 
-	// always pass getGoInfo to golistDriver
-	golistDriver := func(cfg *Config, patterns ...string) (*driverResponse, error) {
-		return golistDriver(cfg, getGoInfo, patterns...)
+	state := &golistState{
+		cfg:        cfg,
+		ctx:        ctx,
+		vendorDirs: map[string]bool{},
 	}
 
 	// 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.
@@ -155,8 +172,6 @@ extractQueries:
 				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:
@@ -172,52 +187,34 @@ extractQueries:
 		}
 	}
 
-	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...)
+		dr, err := state.createDriverResponse(restPatterns...)
 		if err != nil {
 			return nil, err
 		}
-		response.init(dr)
-	} else {
-		response.init(&driverResponse{})
-	}
-
-	sizeswg.Wait()
-	if sizeserr != nil {
-		return nil, sizeserr
+		response.addAll(dr)
 	}
-	// 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, getGoInfo); err != nil {
+		if err := state.runContainsQueries(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, getGoInfo)
+	modifiedPkgs, needPkgs, err := state.processGolistOverlay(response)
 	if err != nil {
 		return nil, err
 	}
+
+	var containsCandidates []string
 	if len(containFiles) > 0 {
 		containsCandidates = append(containsCandidates, modifiedPkgs...)
 		containsCandidates = append(containsCandidates, needPkgs...)
 	}
-	if err := addNeededOverlayPackages(cfg, golistDriver, response, needPkgs, getGoInfo); err != nil {
+	if err := state.addNeededOverlayPackages(response, needPkgs); err != nil {
 		return nil, err
 	}
 	// Check candidate packages for containFiles.
@@ -246,28 +243,32 @@ extractQueries:
 		}
 	}
 
+	sizeswg.Wait()
+	if sizeserr != nil {
+		return nil, sizeserr
+	}
 	return response.dr, nil
 }
 
-func addNeededOverlayPackages(cfg *Config, driver driver, response *responseDeduper, pkgs []string, getGoInfo func() *goInfo) error {
+func (state *golistState) addNeededOverlayPackages(response *responseDeduper, pkgs []string) error {
 	if len(pkgs) == 0 {
 		return nil
 	}
-	dr, err := driver(cfg, pkgs...)
+	dr, err := state.createDriverResponse(pkgs...)
 	if err != nil {
 		return err
 	}
 	for _, pkg := range dr.Packages {
 		response.addPackage(pkg)
 	}
-	_, needPkgs, err := processGolistOverlay(cfg, response, getGoInfo)
+	_, needPkgs, err := state.processGolistOverlay(response)
 	if err != nil {
 		return err
 	}
-	return addNeededOverlayPackages(cfg, driver, response, needPkgs, getGoInfo)
+	return state.addNeededOverlayPackages(response, needPkgs)
 }
 
-func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, queries []string, goInfo func() *goInfo) error {
+func (state *golistState) runContainsQueries(response *responseDeduper, queries []string) error {
 	for _, query := range queries {
 		// TODO(matloob): Do only one query per directory.
 		fdir := filepath.Dir(query)
@@ -277,44 +278,17 @@ func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, q
 		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 || (len(dirResponse.Packages) == 1 && len(dirResponse.Packages[0].Errors) == 1) {
-			// There was an error loading the package. Try to load the file as an ad-hoc package.
-			// Usually the error will appear in a returned package, but may not if we're in modules mode
-			// and the ad-hoc is located outside a module.
+		dirResponse, err := state.createDriverResponse(pattern)
+
+		// If there was an error loading the package, or the package is returned
+		// with errors, try to load the file as an ad-hoc package.
+		// Usually the error will appear in a returned package, but may not if we're
+		// in module mode and the ad-hoc is located outside a module.
+		if err != nil || len(dirResponse.Packages) == 1 && len(dirResponse.Packages[0].GoFiles) == 0 &&
+			len(dirResponse.Packages[0].Errors) == 1 {
 			var queryErr error
-			dirResponse, queryErr = driver(cfg, query)
-			if queryErr != nil {
-				// Return the original error if the attempt to fall back failed.
-				return err
-			}
-			// If we get nothing back from `go list`, try to make this file into its own ad-hoc package.
-			if len(dirResponse.Packages) == 0 && queryErr == nil {
-				dirResponse.Packages = append(dirResponse.Packages, &Package{
-					ID:              "command-line-arguments",
-					PkgPath:         query,
-					GoFiles:         []string{query},
-					CompiledGoFiles: []string{query},
-					Imports:         make(map[string]*Package),
-				})
-				dirResponse.Roots = append(dirResponse.Roots, "command-line-arguments")
-			}
-			// Special case to handle issue #33482:
-			// If this is a file= query for ad-hoc packages where the file only exists on an overlay,
-			// and exists outside of a module, add the file in for the package.
-			if len(dirResponse.Packages) == 1 && (dirResponse.Packages[0].ID == "command-line-arguments" ||
-				filepath.ToSlash(dirResponse.Packages[0].PkgPath) == filepath.ToSlash(query)) {
-				if len(dirResponse.Packages[0].GoFiles) == 0 {
-					filename := filepath.Join(pattern, filepath.Base(query)) // avoid recomputing abspath
-					// TODO(matloob): check if the file is outside of a root dir?
-					for path := range cfg.Overlay {
-						if path == filename {
-							dirResponse.Packages[0].Errors = nil
-							dirResponse.Packages[0].GoFiles = []string{path}
-							dirResponse.Packages[0].CompiledGoFiles = []string{path}
-						}
-					}
-				}
+			if dirResponse, queryErr = state.adhocPackage(pattern, query); queryErr != nil {
+				return err // return the original error
 			}
 		}
 		isRoot := make(map[string]bool, len(dirResponse.Roots))
@@ -342,276 +316,47 @@ func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, q
 	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})
-	cfg.Logf("%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)
-		if err != nil {
-			panic(err) // See above.
-		}
-
-		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([]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")
+// adhocPackage attempts to load or construct an ad-hoc package for a given
+// query, if the original call to the driver produced inadequate results.
+func (state *golistState) adhocPackage(pattern, query string) (*driverResponse, error) {
+	response, err := state.createDriverResponse(query)
 	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)
+		return nil, err
 	}
-
-	var roots []gopathwalk.Root
-	// Always add GOROOT.
-	roots = append(roots, gopathwalk.Root{
-		Path: filepath.Join(goroot, "/src"),
-		Type: gopathwalk.RootGOROOT,
-	})
-	// If modules are enabled, scan the module dir.
-	if modDir != "" {
-		roots = append(roots, gopathwalk.Root{
-			Path: modDir,
-			Type: gopathwalk.RootCurrentModule,
+	// If we get nothing back from `go list`,
+	// try to make this file into its own ad-hoc package.
+	// TODO(rstambler): Should this check against the original response?
+	if len(response.Packages) == 0 {
+		response.Packages = append(response.Packages, &Package{
+			ID:              "command-line-arguments",
+			PkgPath:         query,
+			GoFiles:         []string{query},
+			CompiledGoFiles: []string{query},
+			Imports:         make(map[string]*Package),
 		})
-	}
-	// Add either GOPATH/src or GOPATH/pkg/mod, depending on module mode.
-	for _, p := range gopath {
-		if modDir != "" {
-			roots = append(roots, gopathwalk.Root{
-				Path: filepath.Join(p, "/pkg/mod"),
-				Type: gopathwalk.RootModuleCache,
-			})
-		} else {
-			roots = append(roots, gopathwalk.Root{
-				Path: filepath.Join(p, "/src"),
-				Type: 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:]
+		response.Roots = append(response.Roots, "command-line-arguments")
+	}
+	// Handle special cases.
+	if len(response.Packages) == 1 {
+		// golang/go#33482: If this is a file= query for ad-hoc packages where
+		// the file only exists on an overlay, and exists outside of a module,
+		// add the file to the package and remove the errors.
+		if response.Packages[0].ID == "command-line-arguments" ||
+			filepath.ToSlash(response.Packages[0].PkgPath) == filepath.ToSlash(query) {
+			if len(response.Packages[0].GoFiles) == 0 {
+				filename := filepath.Join(pattern, filepath.Base(query)) // avoid recomputing abspath
+				// TODO(matloob): check if the file is outside of a root dir?
+				for path := range state.cfg.Overlay {
+					if path == filename {
+						response.Packages[0].Errors = nil
+						response.Packages[0].GoFiles = []string{path}
+						response.Packages[0].CompiledGoFiles = []string{path}
+					}
+				}
 			}
 		}
 	}
-	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)
+	return response, nil
 }
 
 // Fields must match go list;
@@ -636,6 +381,7 @@ type jsonPackage struct {
 	Imports         []string
 	ImportMap       map[string]string
 	Deps            []string
+	Module          *packagesinternal.Module
 	TestGoFiles     []string
 	TestImports     []string
 	XTestGoFiles    []string
@@ -656,10 +402,9 @@ 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, rootsDirs func() *goInfo, words ...string) (*driverResponse, error) {
+// createDriverResponse uses the "go list" command to expand the pattern
+// words and return a response for the specified packages.
+func (state *golistState) createDriverResponse(words ...string) (*driverResponse, error) {
 	// go list uses the following identifiers in ImportPath and Imports:
 	//
 	// 	"p"			-- importable package or main (command)
@@ -673,11 +418,13 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 
 	// Run "go list" for complete
 	// information on the specified packages.
-	buf, err := invokeGo(cfg, golistargs(cfg, words)...)
+	buf, err := state.invokeGo("list", golistargs(state.cfg, words)...)
 	if err != nil {
 		return nil, err
 	}
 	seen := make(map[string]*jsonPackage)
+	pkgs := make(map[string]*Package)
+	additionalErrors := make(map[string][]Error)
 	// Decode the JSON and convert it to Package form.
 	var response driverResponse
 	for dec := json.NewDecoder(buf); dec.More(); {
@@ -708,18 +455,72 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 		// contained in a known module or GOPATH entry. This will allow the package to be
 		// properly "reclaimed" when overlays are processed.
 		if filepath.IsAbs(p.ImportPath) && p.Error != nil {
-			pkgPath, ok := getPkgPath(cfg, p.ImportPath, rootsDirs)
+			pkgPath, ok, err := state.getPkgPath(p.ImportPath)
+			if err != nil {
+				return nil, err
+			}
 			if ok {
 				p.ImportPath = pkgPath
 			}
 		}
 
 		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)
+			// If one version of the package has an error, and the other doesn't, assume
+			// that this is a case where go list is reporting a fake dependency variant
+			// of the imported package: When a package tries to invalidly import another
+			// package, go list emits a variant of the imported package (with the same
+			// import path, but with an error on it, and the package will have a
+			// DepError set on it). An example of when this can happen is for imports of
+			// main packages: main packages can not be imported, but they may be
+			// separately matched and listed by another pattern.
+			// See golang.org/issue/36188 for more details.
+
+			// The plan is that eventually, hopefully in Go 1.15, the error will be
+			// reported on the importing package rather than the duplicate "fake"
+			// version of the imported package. Once all supported versions of Go
+			// have the new behavior this logic can be deleted.
+			// TODO(matloob): delete the workaround logic once all supported versions of
+			// Go return the errors on the proper package.
+
+			// There should be exactly one version of a package that doesn't have an
+			// error.
+			if old.Error == nil && p.Error == nil {
+				if !reflect.DeepEqual(p, old) {
+					return nil, fmt.Errorf("internal error: go list gives conflicting information for package %v", p.ImportPath)
+				}
+				continue
 			}
-			// skip the duplicate
-			continue
+
+			// Determine if this package's error needs to be bubbled up.
+			// This is a hack, and we expect for go list to eventually set the error
+			// on the package.
+			if old.Error != nil {
+				var errkind string
+				if strings.Contains(old.Error.Err, "not an importable package") {
+					errkind = "not an importable package"
+				} else if strings.Contains(old.Error.Err, "use of internal package") && strings.Contains(old.Error.Err, "not allowed") {
+					errkind = "use of internal package not allowed"
+				}
+				if errkind != "" {
+					if len(old.Error.ImportStack) < 2 {
+						return nil, fmt.Errorf(`internal error: go list gave a %q error with an import stack with fewer than two elements`, errkind)
+					}
+					importingPkg := old.Error.ImportStack[len(old.Error.ImportStack)-2]
+					additionalErrors[importingPkg] = append(additionalErrors[importingPkg], Error{
+						Pos:  old.Error.Pos,
+						Msg:  old.Error.Err,
+						Kind: ListError,
+					})
+				}
+			}
+
+			// Make sure that if there's a version of the package without an error,
+			// that's the one reported to the user.
+			if old.Error == nil {
+				continue
+			}
+
+			// This package will replace the old one at the end of the loop.
 		}
 		seen[p.ImportPath] = p
 
@@ -729,6 +530,8 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 			GoFiles:         absJoin(p.Dir, p.GoFiles, p.CgoFiles),
 			CompiledGoFiles: absJoin(p.Dir, p.CompiledGoFiles),
 			OtherFiles:      absJoin(p.Dir, otherFiles(p)...),
+			forTest:         p.ForTest,
+			module:          p.Module,
 		}
 
 		// Work around https://golang.org/issue/28749:
@@ -811,34 +614,43 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 				msg += fmt.Sprintf(": import stack: %v", p.Error.ImportStack)
 			}
 			pkg.Errors = append(pkg.Errors, Error{
-				Pos: p.Error.Pos,
-				Msg: msg,
+				Pos:  p.Error.Pos,
+				Msg:  msg,
+				Kind: ListError,
 			})
 		}
 
+		pkgs[pkg.ID] = pkg
+	}
+
+	for id, errs := range additionalErrors {
+		if p, ok := pkgs[id]; ok {
+			p.Errors = append(p.Errors, errs...)
+		}
+	}
+	for _, pkg := range pkgs {
 		response.Packages = append(response.Packages, pkg)
 	}
+	sort.Slice(response.Packages, func(i, j int) bool { return response.Packages[i].ID < response.Packages[j].ID })
 
 	return &response, nil
 }
 
 // getPkgPath finds the package path of a directory if it's relative to a root directory.
-func getPkgPath(cfg *Config, dir string, goInfo func() *goInfo) (string, bool) {
+func (state *golistState) getPkgPath(dir string) (string, bool, error) {
 	absDir, err := filepath.Abs(dir)
 	if err != nil {
-		cfg.Logf("error getting absolute path of %s: %v", dir, err)
-		return "", false
+		return "", false, err
 	}
-	for rdir, rpath := range goInfo().rootDirs {
-		absRdir, err := filepath.Abs(rdir)
-		if err != nil {
-			cfg.Logf("error getting absolute path of %s: %v", rdir, err)
-			continue
-		}
+	roots, err := state.determineRootDirs()
+	if err != nil {
+		return "", false, err
+	}
+
+	for rdir, rpath := range roots {
 		// Make sure that the directory is in the module,
 		// to avoid creating a path relative to another module.
-		if !strings.HasPrefix(absDir, absRdir) {
-			cfg.Logf("%s does not have prefix %s", absDir, absRdir)
+		if !strings.HasPrefix(absDir, rdir) {
 			continue
 		}
 		// TODO(matloob): This doesn't properly handle symlinks.
@@ -853,11 +665,11 @@ func getPkgPath(cfg *Config, dir string, goInfo func() *goInfo) (string, bool) {
 			// Once the file is saved, gopls, or the next invocation of the tool will get the correct
 			// result straight from golist.
 			// TODO(matloob): Implement module tiebreaking?
-			return path.Join(rpath, filepath.ToSlash(r)), true
+			return path.Join(rpath, filepath.ToSlash(r)), true, nil
 		}
-		return filepath.ToSlash(r), true
+		return filepath.ToSlash(r), true, nil
 	}
-	return "", false
+	return "", false, nil
 }
 
 // absJoin absolutizes and flattens the lists of files.
@@ -876,8 +688,8 @@ func absJoin(dir string, fileses ...[]string) (res []string) {
 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),
+		"-e", "-json",
+		fmt.Sprintf("-compiled=%t", cfg.Mode&(NeedCompiledGoFiles|NeedSyntax|NeedTypes|NeedTypesInfo|NeedTypesSizes) != 0),
 		fmt.Sprintf("-test=%t", cfg.Tests),
 		fmt.Sprintf("-export=%t", usesExportData(cfg)),
 		fmt.Sprintf("-deps=%t", cfg.Mode&NeedImports != 0),
@@ -892,25 +704,20 @@ func golistargs(cfg *Config, words []string) []string {
 }
 
 // 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
-	defer func(start time.Time) {
-		cfg.Logf("%s for %v, stderr: <<%s>> stdout: <<%s>>\n", time.Since(start), cmdDebugStr(cmd, args...), stderr, stdout)
-	}(time.Now())
-
-	if err := cmd.Run(); err != nil {
+func (state *golistState) invokeGo(verb string, args ...string) (*bytes.Buffer, error) {
+	cfg := state.cfg
+
+	inv := &gocommand.Invocation{
+		Verb:       verb,
+		Args:       args,
+		BuildFlags: cfg.BuildFlags,
+		Env:        cfg.Env,
+		Logf:       cfg.Logf,
+		WorkingDir: cfg.Dir,
+	}
+
+	stdout, stderr, _, err := inv.RunRaw(cfg.Context)
+	if 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)
@@ -920,7 +727,7 @@ func invokeGo(cfg *Config, args ...string) (*bytes.Buffer, error) {
 		if !ok {
 			// Catastrophic error:
 			// - context cancellation
-			return nil, fmt.Errorf("couldn't exec 'go %v': %s %T", args, err, err)
+			return nil, fmt.Errorf("couldn't run 'go': %v", err)
 		}
 
 		// Old go version?
@@ -947,7 +754,12 @@ func invokeGo(cfg *Config, args ...string) (*bytes.Buffer, error) {
 				!strings.ContainsRune("!\"#$%&'()*,:;<=>?[\\]^`{|}\uFFFD", r)
 		}
 		if len(stderr.String()) > 0 && strings.HasPrefix(stderr.String(), "# ") {
-			if strings.HasPrefix(strings.TrimLeftFunc(stderr.String()[len("# "):], isPkgPathRune), "\n") {
+			msg := stderr.String()[len("# "):]
+			if strings.HasPrefix(strings.TrimLeftFunc(msg, isPkgPathRune), "\n") {
+				return stdout, nil
+			}
+			// Treat pkg-config errors as a special case (golang.org/issue/36770).
+			if strings.HasPrefix(msg, "pkg-config") {
 				return stdout, nil
 			}
 		}
@@ -1036,16 +848,6 @@ func invokeGo(cfg *Config, args ...string) (*bytes.Buffer, error) {
 			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)
-	}
 	return stdout, nil
 }
 
diff --git a/vendor/golang.org/x/tools/go/packages/golist_overlay.go b/vendor/golang.org/x/tools/go/packages/golist_overlay.go
index a7de62299d..7974a6c9bb 100644
--- a/vendor/golang.org/x/tools/go/packages/golist_overlay.go
+++ b/vendor/golang.org/x/tools/go/packages/golist_overlay.go
@@ -1,12 +1,13 @@
 package packages
 
 import (
-	"bytes"
 	"encoding/json"
 	"fmt"
 	"go/parser"
 	"go/token"
+	"os"
 	"path/filepath"
+	"sort"
 	"strconv"
 	"strings"
 )
@@ -16,7 +17,7 @@ import (
 // sometimes incorrect.
 // TODO(matloob): Handle unsupported cases, including the following:
 // - determining the correct package to add given a new import path
-func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func() *goInfo) (modifiedPkgs, needPkgs []string, err error) {
+func (state *golistState) processGolistOverlay(response *responseDeduper) (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)
@@ -34,7 +35,23 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 	// potentially modifying the transitive set of dependencies).
 	var overlayAddsImports bool
 
-	for opath, contents := range cfg.Overlay {
+	// If both a package and its test package are created by the overlay, we
+	// need the real package first. Process all non-test files before test
+	// files, and make the whole process deterministic while we're at it.
+	var overlayFiles []string
+	for opath := range state.cfg.Overlay {
+		overlayFiles = append(overlayFiles, opath)
+	}
+	sort.Slice(overlayFiles, func(i, j int) bool {
+		iTest := strings.HasSuffix(overlayFiles[i], "_test.go")
+		jTest := strings.HasSuffix(overlayFiles[j], "_test.go")
+		if iTest != jTest {
+			return !iTest // non-tests are before tests.
+		}
+		return overlayFiles[i] < overlayFiles[j]
+	})
+	for _, opath := range overlayFiles {
+		contents := state.cfg.Overlay[opath]
 		base := filepath.Base(opath)
 		dir := filepath.Dir(opath)
 		var pkg *Package           // if opath belongs to both a package and its test variant, this will be the test variant
@@ -64,14 +81,8 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 					testVariantOf = p
 					continue nextPackage
 				}
+				// We must have already seen the package of which this is a test variant.
 				if pkg != nil && p != pkg && pkg.PkgPath == p.PkgPath {
-					// If we've already seen the test variant,
-					// make sure to label which package it is a test variant of.
-					if hasTestFiles(pkg) {
-						testVariantOf = p
-						continue nextPackage
-					}
-					// If we have already seen the package of which this is a test variant.
 					if hasTestFiles(p) {
 						testVariantOf = pkg
 					}
@@ -86,7 +97,10 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 		if pkg == nil {
 			// Try to find the module or gopath dir the file is contained in.
 			// Then for modules, add the module opath to the beginning.
-			pkgPath, ok := getPkgPath(cfg, dir, rootDirs)
+			pkgPath, ok, err := state.getPkgPath(dir)
+			if err != nil {
+				return nil, nil, err
+			}
 			if !ok {
 				break
 			}
@@ -114,6 +128,11 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 				if isTestFile && !isXTest && testVariantOf != nil {
 					pkg.GoFiles = append(pkg.GoFiles, testVariantOf.GoFiles...)
 					pkg.CompiledGoFiles = append(pkg.CompiledGoFiles, testVariantOf.CompiledGoFiles...)
+					// Add the package under test and its imports to the test variant.
+					pkg.forTest = testVariantOf.PkgPath
+					for k, v := range testVariantOf.Imports {
+						pkg.Imports[k] = &Package{ID: v.ID}
+					}
 				}
 			}
 		}
@@ -130,42 +149,45 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 			continue
 		}
 		for _, imp := range imports {
-			_, found := pkg.Imports[imp]
-			if !found {
-				overlayAddsImports = true
-				// TODO(matloob): Handle cases when the following block isn't correct.
-				// These include imports of vendored packages, etc.
-				id, ok := havePkgs[imp]
-				if !ok {
-					id = imp
-				}
-				pkg.Imports[imp] = &Package{ID: id}
-				// Add dependencies to the non-test variant version of this package as wel.
-				if testVariantOf != nil {
-					testVariantOf.Imports[imp] = &Package{ID: id}
+			if _, found := pkg.Imports[imp]; found {
+				continue
+			}
+			overlayAddsImports = true
+			id, ok := havePkgs[imp]
+			if !ok {
+				var err error
+				id, err = state.resolveImport(dir, imp)
+				if err != nil {
+					return nil, nil, err
 				}
 			}
+			pkg.Imports[imp] = &Package{ID: id}
+			// Add dependencies to the non-test variant version of this package as well.
+			if testVariantOf != nil {
+				testVariantOf.Imports[imp] = &Package{ID: id}
+			}
 		}
-		continue
 	}
 
-	// toPkgPath tries to guess the package path given the id.
-	// This isn't always correct -- it's certainly wrong for
-	// vendored packages' paths.
-	toPkgPath := func(id string) string {
-		// TODO(matloob): Handle vendor paths.
-		i := strings.IndexByte(id, ' ')
-		if i >= 0 {
-			return id[:i]
+	// toPkgPath guesses the package path given the id.
+	toPkgPath := func(sourceDir, id string) (string, error) {
+		if i := strings.IndexByte(id, ' '); i >= 0 {
+			return state.resolveImport(sourceDir, id[:i])
 		}
-		return id
+		return state.resolveImport(sourceDir, id)
 	}
 
-	// Do another pass now that new packages have been created to determine the
-	// set of missing packages.
+	// Now that new packages have been created, do another pass to determine
+	// the new set of missing packages.
 	for _, pkg := range response.dr.Packages {
 		for _, imp := range pkg.Imports {
-			pkgPath := toPkgPath(imp.ID)
+			if len(pkg.GoFiles) == 0 {
+				return nil, nil, fmt.Errorf("cannot resolve imports for package %q with no Go files", pkg.PkgPath)
+			}
+			pkgPath, err := toPkgPath(filepath.Dir(pkg.GoFiles[0]), imp.ID)
+			if err != nil {
+				return nil, nil, err
+			}
 			if _, ok := havePkgs[pkgPath]; !ok {
 				needPkgsSet[pkgPath] = true
 			}
@@ -185,6 +207,52 @@ func processGolistOverlay(cfg *Config, response *responseDeduper, rootDirs func(
 	return modifiedPkgs, needPkgs, err
 }
 
+// resolveImport finds the the ID of a package given its import path.
+// In particular, it will find the right vendored copy when in GOPATH mode.
+func (state *golistState) resolveImport(sourceDir, importPath string) (string, error) {
+	env, err := state.getEnv()
+	if err != nil {
+		return "", err
+	}
+	if env["GOMOD"] != "" {
+		return importPath, nil
+	}
+
+	searchDir := sourceDir
+	for {
+		vendorDir := filepath.Join(searchDir, "vendor")
+		exists, ok := state.vendorDirs[vendorDir]
+		if !ok {
+			info, err := os.Stat(vendorDir)
+			exists = err == nil && info.IsDir()
+			state.vendorDirs[vendorDir] = exists
+		}
+
+		if exists {
+			vendoredPath := filepath.Join(vendorDir, importPath)
+			if info, err := os.Stat(vendoredPath); err == nil && info.IsDir() {
+				// We should probably check for .go files here, but shame on anyone who fools us.
+				path, ok, err := state.getPkgPath(vendoredPath)
+				if err != nil {
+					return "", err
+				}
+				if ok {
+					return path, nil
+				}
+			}
+		}
+
+		// We know we've hit the top of the filesystem when we Dir / and get /,
+		// or C:\ and get C:\, etc.
+		next := filepath.Dir(searchDir)
+		if next == searchDir {
+			break
+		}
+		searchDir = next
+	}
+	return importPath, nil
+}
+
 func hasTestFiles(p *Package) bool {
 	for _, f := range p.GoFiles {
 		if strings.HasSuffix(f, "_test.go") {
@@ -194,44 +262,59 @@ func hasTestFiles(p *Package) bool {
 	return false
 }
 
-// determineRootDirs returns a mapping from directories code can be contained in to the
-// corresponding import path prefixes of those directories.
-// Its result is used to try to determine the import path for a package containing
-// an overlay file.
-func determineRootDirs(cfg *Config) map[string]string {
-	// Assume modules first:
-	out, err := invokeGo(cfg, "list", "-m", "-json", "all")
+// determineRootDirs returns a mapping from absolute directories that could
+// contain code to their corresponding import path prefixes.
+func (state *golistState) determineRootDirs() (map[string]string, error) {
+	env, err := state.getEnv()
 	if err != nil {
-		return determineRootDirsGOPATH(cfg)
+		return nil, err
+	}
+	if env["GOMOD"] != "" {
+		state.rootsOnce.Do(func() {
+			state.rootDirs, state.rootDirsError = state.determineRootDirsModules()
+		})
+	} else {
+		state.rootsOnce.Do(func() {
+			state.rootDirs, state.rootDirsError = state.determineRootDirsGOPATH()
+		})
+	}
+	return state.rootDirs, state.rootDirsError
+}
+
+func (state *golistState) determineRootDirsModules() (map[string]string, error) {
+	out, err := state.invokeGo("list", "-m", "-json", "all")
+	if err != nil {
+		return nil, err
 	}
 	m := map[string]string{}
 	type jsonMod struct{ Path, Dir string }
 	for dec := json.NewDecoder(out); dec.More(); {
 		mod := new(jsonMod)
 		if err := dec.Decode(mod); err != nil {
-			return m // Give up and return an empty map. Package won't be found for overlay.
+			return nil, err
 		}
 		if mod.Dir != "" && mod.Path != "" {
 			// This is a valid module; add it to the map.
-			m[mod.Dir] = mod.Path
+			absDir, err := filepath.Abs(mod.Dir)
+			if err != nil {
+				return nil, err
+			}
+			m[absDir] = mod.Path
 		}
 	}
-	return m
+	return m, nil
 }
 
-func determineRootDirsGOPATH(cfg *Config) map[string]string {
+func (state *golistState) determineRootDirsGOPATH() (map[string]string, error) {
 	m := map[string]string{}
-	out, err := invokeGo(cfg, "env", "GOPATH")
-	if err != nil {
-		// Could not determine root dir mapping. Everything is best-effort, so just return an empty map.
-		// When we try to find the import path for a directory, there will be no root-dir match and
-		// we'll give up.
-		return m
-	}
-	for _, p := range filepath.SplitList(string(bytes.TrimSpace(out.Bytes()))) {
-		m[filepath.Join(p, "src")] = ""
+	for _, dir := range filepath.SplitList(state.mustGetEnv()["GOPATH"]) {
+		absDir, err := filepath.Abs(dir)
+		if err != nil {
+			return nil, err
+		}
+		m[filepath.Join(absDir, "src")] = ""
 	}
-	return m
+	return m, nil
 }
 
 func extractImports(filename string, contents []byte) ([]string, error) {
diff --git a/vendor/golang.org/x/tools/go/packages/packages.go b/vendor/golang.org/x/tools/go/packages/packages.go
index 050cca43a2..1ac6558c1d 100644
--- a/vendor/golang.org/x/tools/go/packages/packages.go
+++ b/vendor/golang.org/x/tools/go/packages/packages.go
@@ -23,6 +23,7 @@ import (
 	"sync"
 
 	"golang.org/x/tools/go/gcexportdata"
+	"golang.org/x/tools/internal/packagesinternal"
 )
 
 // A LoadMode controls the amount of detail to return when loading.
@@ -34,6 +35,9 @@ import (
 // Load may return more information than requested.
 type LoadMode int
 
+// TODO(matloob): When a V2 of go/packages is released, rename NeedExportsFile to
+// NeedExportFile to make it consistent with the Package field it's adding.
+
 const (
 	// NeedName adds Name and PkgPath.
 	NeedName LoadMode = 1 << iota
@@ -51,7 +55,7 @@ const (
 	// NeedDeps adds the fields requested by the LoadMode in the packages in Imports.
 	NeedDeps
 
-	// NeedExportsFile adds ExportsFile.
+	// NeedExportsFile adds ExportFile.
 	NeedExportsFile
 
 	// NeedTypes adds Types, Fset, and IllTyped.
@@ -160,7 +164,7 @@ type Config struct {
 	Tests bool
 
 	// Overlay provides a mapping of absolute file paths to file contents.
-	// If the file  with the given path already exists, the parser will use the
+	// If the file with the given path already exists, the parser will use the
 	// alternative file contents provided by the map.
 	//
 	// Overlays provide incomplete support for when a given file doesn't
@@ -292,6 +296,21 @@ type Package struct {
 
 	// TypesSizes provides the effective size function for types in TypesInfo.
 	TypesSizes types.Sizes
+
+	// forTest is the package under test, if any.
+	forTest string
+
+	// module is the module information for the package if it exists.
+	module *packagesinternal.Module
+}
+
+func init() {
+	packagesinternal.GetForTest = func(p interface{}) string {
+		return p.(*Package).forTest
+	}
+	packagesinternal.GetModule = func(p interface{}) *packagesinternal.Module {
+		return p.(*Package).module
+	}
 }
 
 // An Error describes a problem with a package's metadata, syntax, or types.
@@ -500,12 +519,23 @@ func (ld *loader) refine(roots []string, list ...*Package) ([]*Package, error) {
 		if i, found := rootMap[pkg.ID]; found {
 			rootIndex = i
 		}
+
+		// Overlays can invalidate export data.
+		// TODO(matloob): make this check fine-grained based on dependencies on overlaid files
+		exportDataInvalid := len(ld.Overlay) > 0 || pkg.ExportFile == "" && pkg.PkgPath != "unsafe"
+		// This package needs type information if the caller requested types and the package is
+		// either a root, or it's a non-root and the user requested dependencies ...
+		needtypes := (ld.Mode&NeedTypes|NeedTypesInfo != 0 && (rootIndex >= 0 || ld.Mode&NeedDeps != 0))
+		// This package needs source if the call requested source (or types info, which implies source)
+		// and the package is either a root, or itas a non- root and the user requested dependencies...
+		needsrc := ((ld.Mode&(NeedSyntax|NeedTypesInfo) != 0 && (rootIndex >= 0 || ld.Mode&NeedDeps != 0)) ||
+			// ... or if we need types and the exportData is invalid. We fall back to (incompletely)
+			// typechecking packages from source if they fail to compile.
+			(ld.Mode&NeedTypes|NeedTypesInfo != 0 && exportDataInvalid)) && pkg.PkgPath != "unsafe"
 		lpkg := &loaderPackage{
 			Package:   pkg,
-			needtypes: (ld.Mode&(NeedTypes|NeedTypesInfo) != 0 && ld.Mode&NeedDeps != 0 && rootIndex < 0) || rootIndex >= 0,
-			needsrc: (ld.Mode&(NeedSyntax|NeedTypesInfo) != 0 && ld.Mode&NeedDeps != 0 && rootIndex < 0) || rootIndex >= 0 ||
-				len(ld.Overlay) > 0 || // Overlays can invalidate export data. TODO(matloob): make this check fine-grained based on dependencies on overlaid files
-				pkg.ExportFile == "" && pkg.PkgPath != "unsafe",
+			needtypes: needtypes,
+			needsrc:   needsrc,
 		}
 		ld.pkgs[lpkg.ID] = lpkg
 		if rootIndex >= 0 {
@@ -713,7 +743,7 @@ func (ld *loader) loadPackage(lpkg *loaderPackage) {
 	// which would then require that such created packages be explicitly
 	// inserted back into the Import graph as a final step after export data loading.
 	// The Diamond test exercises this case.
-	if !lpkg.needtypes {
+	if !lpkg.needtypes && !lpkg.needsrc {
 		return
 	}
 	if !lpkg.needsrc {