Update golang.org/x/lint commit hash to 738671d (#223)

Update golang.org/x/lint commit hash to 738671d

Reviewed-on: https://kolaente.dev/vikunja/api/pulls/223

go.mod

@@ -70,10 +70,9 @@ require (
 	github.com/ulule/limiter/v3 v3.3.0
 	github.com/urfave/cli v1.22.2 // indirect
 	golang.org/x/crypto v0.0.0-20200208060501-ecb85df21340
-	golang.org/x/lint v0.0.0-20190409202823-959b441ac422
+	golang.org/x/lint v0.0.0-20200302205851-738671d3881b
 	golang.org/x/net v0.0.0-20200202094626-16171245cfb2 // indirect
 	golang.org/x/sys v0.0.0-20200202164722-d101bd2416d5 // indirect
-	golang.org/x/tools v0.0.0-20191130070609-6e064ea0cf2d // indirect
 	gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc // indirect
 	gopkg.in/d4l3k/messagediff.v1 v1.2.1
 	gopkg.in/gomail.v2 v2.0.0-20160411212932-81ebce5c23df

go.sum

@@ -345,6 +345,7 @@ golang.org/x/crypto v0.0.0-20190605123033-f99c8df09eb5/go.mod h1:yigFU9vqHzYiE8U
 golang.org/x/crypto v0.0.0-20190611184440-5c40567a22f8/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4 h1:ydJNl0ENAG67pFbB+9tfhiL2pYqLhfoaZFw/cjLhY4A=
 golang.org/x/crypto v0.0.0-20190621222207-cc06ce4a13d4/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
 golang.org/x/crypto v0.0.0-20191227163750-53104e6ec876/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
 golang.org/x/crypto v0.0.0-20200208060501-ecb85df21340 h1:KOcEaR10tFr7gdJV2GCKw8Os5yED1u1aOqHjOAb6d2Y=
 golang.org/x/crypto v0.0.0-20200208060501-ecb85df21340/go.mod h1:LzIPMQfyMNhhGPhUkYOs5KpL4U8rLKemX1yGLhDgUto=
@@ -354,6 +355,9 @@ golang.org/x/lint v0.0.0-20190227174305-5b3e6a55c961/go.mod h1:wehouNa3lNwaWXcvx
 golang.org/x/lint v0.0.0-20190301231843-5614ed5bae6f/go.mod h1:UVdnD1Gm6xHRNCYTkRU2/jEulfH38KcIWyp/GAMgvoE=
 golang.org/x/lint v0.0.0-20190409202823-959b441ac422 h1:QzoH/1pFpZguR8NrRHLcO6jKqfv2zpuSqZLgdm7ZmjI=
 golang.org/x/lint v0.0.0-20190409202823-959b441ac422/go.mod h1:6SW0HCj/g11FgYtHlgUYUwCkIfeOF89ocIRzGO/8vkc=
+golang.org/x/lint v0.0.0-20200302205851-738671d3881b h1:Wh+f8QHJXR411sJR8/vRBTZ7YapZaRvUcLFFJhusH0k=
+golang.org/x/lint v0.0.0-20200302205851-738671d3881b/go.mod h1:3xt1FjdF8hUf6vQPIChWIBhFzV8gjjsPE/fR3IyQdNY=
+golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
 golang.org/x/net v0.0.0-20180724234803-3673e40ba225/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180826012351-8a410e7b638d/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
 golang.org/x/net v0.0.0-20180906233101-161cd47e91fd/go.mod h1:mL1N/T3taQHkDXs73rZJwtUhF3w3ftmwwsq0BUmARs4=
@@ -431,7 +435,10 @@ golang.org/x/tools v0.0.0-20190628034336-212fb13d595e h1:ZlQjfVdpDxeqxRfmO30CdqW
 golang.org/x/tools v0.0.0-20190628034336-212fb13d595e/go.mod h1:/rFqwRUd4F7ZHNgwSSTFct+R/Kf4OFW1sUzUTQQTgfc=
 golang.org/x/tools v0.0.0-20191130070609-6e064ea0cf2d h1:/iIZNFGxc/a7C3yWjGcnboV+Tkc7mxr+p6fDztwoxuM=
 golang.org/x/tools v0.0.0-20191130070609-6e064ea0cf2d/go.mod h1:b+2E5dAYhXwXZwtnZ6UAqBI28+e2cm9otk0dWdXHAEo=
+golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7 h1:EBZoQjiKKPaLbPrbpssUfuHtwM6KV/vb4U85g/cigFY=
+golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
 golang.org/x/xerrors v0.0.0-20190717185122-a985d3407aa7/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=
 google.golang.org/api v0.3.1/go.mod h1:6wY9I6uQWHQ8EM57III9mq/AjF+i8G65rmVagqKMtkk=
 google.golang.org/appengine v1.1.0/go.mod h1:EbEs0AVv82hx2wNQdGPgUI5lhzA/G0D9YwlJXL52JkM=
 google.golang.org/appengine v1.3.0 h1:FBSsiFRMz3LBeXIomRnVzrQwSDj4ibvcRexLG0LZGQk=

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

@@ -78,7 +78,7 @@ Optionally, add this to your `~/.vimrc` to automatically run `golint` on `:w`
 
 Add this to your `.emacs` file:
 
-    (add-to-list 'load-path (concat (getenv "GOPATH")  "/src/github.com/golang/lint/misc/emacs"))
+    (add-to-list 'load-path (concat (getenv "GOPATH")  "/src/golang.org/x/lint/misc/emacs/"))
     (require 'golint)
 
 If you have multiple entries in your GOPATH, replace `$GOPATH` with the right value.

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

@@ -1,3 +1,5 @@
 module golang.org/x/lint
 
-require golang.org/x/tools v0.0.0-20190311212946-11955173bddd
+go 1.11
+
+require golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7

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

@@ -1,6 +1,12 @@
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
-golang.org/x/net v0.0.0-20190311183353-d8887717615a/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/crypto v0.0.0-20191011191535-87dc89f01550/go.mod h1:yigFU9vqHzYiE8UmvKecakEJjdnWj3jj499lnFckfCI=
+golang.org/x/mod v0.1.1-0.20191105210325-c90efee705ee/go.mod h1:QqPTAvyqsEbceGzBzNggFXnrqF1CaUcvgkdR5Ot7KZg=
+golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
+golang.org/x/net v0.0.0-20190620200207-3b0461eec859/go.mod h1:z5CRVTTTmAJ677TzLLGU+0bjPO0LkuOLi4/5GtJWs/s=
+golang.org/x/sync v0.0.0-20190423024810-112230192c58/go.mod h1:RxMgew5VJxzue5/jJTE5uejpjVlOe/izrB70Jof72aM=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
+golang.org/x/sys v0.0.0-20190412213103-97732733099d/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=
-golang.org/x/tools v0.0.0-20190311212946-11955173bddd h1:/e+gpKk9r3dJobndpTytxS2gOy6m5uvpg+ISQoEcusQ=
+golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7 h1:EBZoQjiKKPaLbPrbpssUfuHtwM6KV/vb4U85g/cigFY=
-golang.org/x/tools v0.0.0-20190311212946-11955173bddd/go.mod h1:LCzVGOaR6xXOjkQ3onu1FJEFr0SW1gC7cKk1uF8kGRs=
+golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7/go.mod h1:TB2adYChydJhpapKDTa4BR/hXlZSLoq2Wpct/0txZ28=
+golang.org/x/xerrors v0.0.0-20191011141410-1b5146add898/go.mod h1:I/5z698sn9Ka8TeJc9MKroUUfqBBauWjQqLJ2OPfmY0=

vendor/golang.org/x/lint/lint.go

@@ -198,7 +198,6 @@ func (f *file) lint() {
 	f.lintBlankImports()
 	f.lintExported()
 	f.lintNames()
-	f.lintVarDecls()
 	f.lintElses()
 	f.lintRanges()
 	f.lintErrorf()
@@ -840,6 +839,7 @@ var commonMethods = map[string]bool{
 	"ServeHTTP": true,
 	"String":    true,
 	"Write":     true,
+	"Unwrap":    true,
 }
 
 // lintFuncDoc examines doc comments on functions and methods.
@@ -977,84 +977,6 @@ var zeroLiteral = map[string]bool{
 	"0i":  true,
 }
 
-// lintVarDecls examines variable declarations. It complains about declarations with
-// redundant LHS types that can be inferred from the RHS.
-func (f *file) lintVarDecls() {
-	var lastGen *ast.GenDecl // last GenDecl entered.
-
-	f.walk(func(node ast.Node) bool {
-		switch v := node.(type) {
-		case *ast.GenDecl:
-			if v.Tok != token.CONST && v.Tok != token.VAR {
-				return false
-			}
-			lastGen = v
-			return true
-		case *ast.ValueSpec:
-			if lastGen.Tok == token.CONST {
-				return false
-			}
-			if len(v.Names) > 1 || v.Type == nil || len(v.Values) == 0 {
-				return false
-			}
-			rhs := v.Values[0]
-			// An underscore var appears in a common idiom for compile-time interface satisfaction,
-			// as in "var _ Interface = (*Concrete)(nil)".
-			if isIdent(v.Names[0], "_") {
-				return false
-			}
-			// If the RHS is a zero value, suggest dropping it.
-			zero := false
-			if lit, ok := rhs.(*ast.BasicLit); ok {
-				zero = zeroLiteral[lit.Value]
-			} else if isIdent(rhs, "nil") {
-				zero = true
-			}
-			if zero {
-				f.errorf(rhs, 0.9, category("zero-value"), "should drop = %s from declaration of var %s; it is the zero value", f.render(rhs), v.Names[0])
-				return false
-			}
-			lhsTyp := f.pkg.typeOf(v.Type)
-			rhsTyp := f.pkg.typeOf(rhs)
-
-			if !validType(lhsTyp) || !validType(rhsTyp) {
-				// Type checking failed (often due to missing imports).
-				return false
-			}
-
-			if !types.Identical(lhsTyp, rhsTyp) {
-				// Assignment to a different type is not redundant.
-				return false
-			}
-
-			// The next three conditions are for suppressing the warning in situations
-			// where we were unable to typecheck.
-
-			// If the LHS type is an interface, don't warn, since it is probably a
-			// concrete type on the RHS. Note that our feeble lexical check here
-			// will only pick up interface{} and other literal interface types;
-			// that covers most of the cases we care to exclude right now.
-			if _, ok := v.Type.(*ast.InterfaceType); ok {
-				return false
-			}
-			// If the RHS is an untyped const, only warn if the LHS type is its default type.
-			if defType, ok := f.isUntypedConst(rhs); ok && !isIdent(v.Type, defType) {
-				return false
-			}
-
-			f.errorf(v.Type, 0.8, category("type-inference"), "should omit type %s from declaration of var %s; it will be inferred from the right-hand side", f.render(v.Type), v.Names[0])
-			return false
-		}
-		return true
-	})
-}
-
-func validType(T types.Type) bool {
-	return T != nil &&
-		T != types.Typ[types.Invalid] &&
-		!strings.Contains(T.String(), "invalid type") // good but not foolproof
-}
-
 // lintElses examines else blocks. It complains about any else block whose if block ends in a return.
 func (f *file) lintElses() {
 	// We don't want to flag if { } else if { } else { } constructions.

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.

vendor/golang.org/x/tools/go/ast/inspector/inspector.go

@@ -90,7 +90,7 @@ func (in *Inspector) Preorder(types []ast.Node, f func(ast.Node)) {
 // The types argument, if non-empty, enables type-based filtering of
 // events. The function f if is called only for nodes whose type
 // matches an element of the types slice.
-func (in *Inspector) Nodes(types []ast.Node, f func(n ast.Node, push bool) (prune bool)) {
+func (in *Inspector) Nodes(types []ast.Node, f func(n ast.Node, push bool) (proceed bool)) {
 	mask := maskOf(types)
 	for i := 0; i < len(in.events); {
 		ev := in.events[i]
@@ -114,7 +114,7 @@ func (in *Inspector) Nodes(types []ast.Node, f func(n ast.Node, push bool) (prun
 // supplies each call to f an additional argument, the current
 // traversal stack. The stack's first element is the outermost node,
 // an *ast.File; its last is the innermost, n.
-func (in *Inspector) WithStack(types []ast.Node, f func(n ast.Node, push bool, stack []ast.Node) (prune bool)) {
+func (in *Inspector) WithStack(types []ast.Node, f func(n ast.Node, push bool, stack []ast.Node) (proceed bool)) {
 	mask := maskOf(types)
 	var stack []ast.Node
 	for i := 0; i < len(in.events); {

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
+// Package cgo handles cgo preprocessing of files containing `import "C"`.
-
-// This file 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"

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" } .

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

@@ -60,8 +60,7 @@ 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
+reported about the loaded packages. See the documentation for type LoadMode
-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)

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

@@ -84,13 +84,14 @@ func findExternalDriver(cfg *Config) driver {
 		cmd.Stdin = bytes.NewReader(req)
 		cmd.Stdout = buf
 		cmd.Stderr = stderr
-		if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTDRIVERERRORS") != "" {
-			fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(cmd, words...), stderr)
-		}
 
 		if err := cmd.Run(); err != nil {
 			return nil, fmt.Errorf("%v: %v: %s", tool, err, cmd.Stderr)
 		}
+		if len(stderr.Bytes()) != 0 && os.Getenv("GOPACKAGESPRINTDRIVERERRORS") != "" {
+			fmt.Fprintf(os.Stderr, "%s stderr: <<%s>>\n", cmdDebugStr(cmd, words...), stderr)
+		}
+
 		var response driverResponse
 		if err := json.Unmarshal(buf.Bytes(), &response); err != nil {
 			return nil, err

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

@@ -6,17 +6,16 @@ package packages
 
 import (
 	"bytes"
+	"context"
 	"encoding/json"
 	"fmt"
 	"go/types"
-	"io/ioutil"
 	"log"
 	"os"
 	"os/exec"
 	"path"
 	"path/filepath"
 	"reflect"
-	"regexp"
 	"strconv"
 	"strings"
 	"sync"
@@ -24,9 +23,6 @@ import (
 	"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/span"
 )
 
 // debug controls verbose logging.
@@ -45,16 +41,21 @@ type responseDeduper struct {
 	dr           *driverResponse
 }
 
-// init fills in r with a driverResponse.
+func newDeduper() *responseDeduper {
-func (r *responseDeduper) init(dr *driverResponse) {
+	return &responseDeduper{
-	r.dr = dr
+		dr:           &driverResponse{},
-	r.seenRoots = map[string]bool{}
+		seenRoots:    map[string]bool{},
-	r.seenPackages = map[string]*Package{}
+		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)
 	}
 }
 
@@ -74,25 +75,47 @@ func (r *responseDeduper) addRoot(id string) {
 	r.dr.Roots = append(r.dr.Roots, id)
 }
 
-// goInfo contains global information from the go tool.
+type golistState struct {
-type goInfo struct {
+	cfg *Config
+	ctx context.Context
+
+	envOnce    sync.Once
+	goEnvError error
+	goEnv      map[string]string
+
+	rootsOnce     sync.Once
+	rootDirsError error
 	rootDirs      map[string]string
-	env      goEnv
+
+	// vendorDirs caches the (non)existence of vendor directories.
+	vendorDirs map[string]bool
 }
 
-type goEnv struct {
+// getEnv returns Go environment variables. Only specific variables are
-	modulesOn bool
+// populated -- computing all of them is slow.
-}
+func (state *golistState) getEnv() (map[string]string, error) {
-
+	state.envOnce.Do(func() {
-func determineEnv(cfg *Config) goEnv {
+		var b *bytes.Buffer
-	buf, err := invokeGo(cfg, "env", "GOMOD")
+		b, state.goEnvError = state.invokeGo("env", "-json", "GOMOD", "GOPATH")
-	if err != nil {
+		if state.goEnvError != nil {
-		return goEnv{}
+			return
 		}
-	gomod := bytes.TrimSpace(buf.Bytes())
 
-	env := goEnv{}
+		state.goEnv = make(map[string]string)
-	env.modulesOn = len(gomod) > 0
+		decoder := json.NewDecoder(b)
+		if state.goEnvError = decoder.Decode(&state.goEnv); state.goEnvError != nil {
+			return
+		}
+	})
+	return state.goEnv, state.goEnvError
+}
+
+// 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 {
+		panic(fmt.Sprintf("mustGetEnv: %v", err))
+	}
 	return env
 }
 
@@ -100,47 +123,38 @@ 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
+	state := &golistState{
-	var info goInfo
+		cfg:        cfg,
-	var rootDirsReady, envReady = make(chan struct{}), make(chan struct{})
+		ctx:        ctx,
-	go func() {
+		vendorDirs: map[string]bool{},
-		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...)
 	}
 
 	// 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.
@@ -156,8 +170,6 @@ 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:
@@ -173,52 +185,34 @@ 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)
+		response.addAll(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, getGoInfo); err != nil {
+		if err := state.runContainsQueries(response, containFiles); err != nil {
 			return nil, err
 		}
 	}
 
-	if len(packagesNamed) != 0 {
+	modifiedPkgs, needPkgs, err := state.processGolistOverlay(response)
-		if err := runNamedQueries(cfg, golistDriver, response, packagesNamed); err != nil {
-			return nil, err
-		}
-	}
-
-	modifiedPkgs, needPkgs, err := processGolistOverlay(cfg, response, getGoInfo)
 	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.
@@ -247,33 +241,32 @@ 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
 	}
-	drivercfg := *cfg
+	dr, err := state.createDriverResponse(pkgs...)
-	if getGoInfo().env.modulesOn {
-		drivercfg.BuildFlags = append(drivercfg.BuildFlags, "-mod=readonly")
-	}
-	dr, err := driver(&drivercfg, 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)
@@ -283,42 +276,16 @@ 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)
+		dirResponse, err := state.createDriverResponse(pattern)
-		if err != nil {
+
+		// 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
-			if dirResponse, queryErr = adHocPackage(cfg, driver, pattern, query); queryErr != nil {
+			if dirResponse, queryErr = state.adhocPackage(pattern, query); queryErr != nil {
-				return err // return the original error
-			}
-		}
-		// `go list` can report errors for files that are not listed as part of a package's GoFiles.
-		// In the case of an invalid Go file, we should assume that it is part of package if only
-		// one package is in the response. The file may have valid contents in an overlay.
-		if len(dirResponse.Packages) == 1 {
-			pkg := dirResponse.Packages[0]
-			for i, err := range pkg.Errors {
-				s := errorSpan(err)
-				if !s.IsValid() {
-					break
-				}
-				if len(pkg.CompiledGoFiles) == 0 {
-					break
-				}
-				dir := filepath.Dir(pkg.CompiledGoFiles[0])
-				filename := filepath.Join(dir, filepath.Base(s.URI().Filename()))
-				if info, err := os.Stat(filename); err != nil || info.IsDir() {
-					break
-				}
-				if !contains(pkg.CompiledGoFiles, filename) {
-					pkg.CompiledGoFiles = append(pkg.CompiledGoFiles, filename)
-					pkg.GoFiles = append(pkg.GoFiles, filename)
-					pkg.Errors = append(pkg.Errors[:i], pkg.Errors[i+1:]...)
-				}
-			}
-		}
-		// A final attempt to construct an ad-hoc package.
-		if len(dirResponse.Packages) == 1 && len(dirResponse.Packages[0].Errors) == 1 {
-			var queryErr error
-			if dirResponse, queryErr = adHocPackage(cfg, driver, pattern, query); queryErr != nil {
 				return err // return the original error
 			}
 		}
@@ -347,345 +314,47 @@ func runContainsQueries(cfg *Config, driver driver, response *responseDeduper, q
 	return nil
 }
 
-// adHocPackage attempts to construct an ad-hoc package given a query that failed.
+// adhocPackage attempts to load or construct an ad-hoc package for a given
-func adHocPackage(cfg *Config, driver driver, pattern, query string) (*driverResponse, error) {
+// query, if the original call to the driver produced inadequate results.
-	// There was an error loading the package. Try to load the file as an ad-hoc package.
+func (state *golistState) adhocPackage(pattern, query string) (*driverResponse, error) {
-	// Usually the error will appear in a returned package, but may not if we're in modules mode
+	response, err := state.createDriverResponse(query)
-	// and the ad-hoc is located outside a module.
-	dirResponse, err := driver(cfg, query)
 	if err != nil {
 		return nil, err
 	}
-	// If we get nothing back from `go list`, try to make this file into its own ad-hoc package.
+	// If we get nothing back from `go list`,
-	if len(dirResponse.Packages) == 0 && err == nil {
+	// try to make this file into its own ad-hoc package.
-		dirResponse.Packages = append(dirResponse.Packages, &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),
 		})
-		dirResponse.Roots = append(dirResponse.Roots, "command-line-arguments")
+		response.Roots = append(response.Roots, "command-line-arguments")
 	}
-	// Special case to handle issue #33482:
+	// Handle special cases.
-	// If this is a file= query for ad-hoc packages where the file only exists on an overlay,
+	if len(response.Packages) == 1 {
-	// and exists outside of a module, add the file in for the package.
+		// golang/go#33482: If this is a file= query for ad-hoc packages where
-	if len(dirResponse.Packages) == 1 && (dirResponse.Packages[0].ID == "command-line-arguments" ||
+		// the file only exists on an overlay, and exists outside of a module,
-		filepath.ToSlash(dirResponse.Packages[0].PkgPath) == filepath.ToSlash(query)) {
+		// add the file to the package and remove the errors.
-		if len(dirResponse.Packages[0].GoFiles) == 0 {
+		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 cfg.Overlay {
+				for path := range state.cfg.Overlay {
 					if path == filename {
-					dirResponse.Packages[0].Errors = nil
+						response.Packages[0].Errors = nil
-					dirResponse.Packages[0].GoFiles = []string{path}
+						response.Packages[0].GoFiles = []string{path}
-					dirResponse.Packages[0].CompiledGoFiles = []string{path}
+						response.Packages[0].CompiledGoFiles = []string{path}
 					}
 				}
 			}
 		}
-	return dirResponse, nil
-}
-
-func contains(files []string, filename string) bool {
-	for _, f := range files {
-		if f == filename {
-			return true
 	}
-	}
+	return response, nil
-	return false
-}
-
-// errorSpan attempts to parse a standard `go list` error message
-// by stripping off the trailing error message.
-//
-// It works only on errors whose message is prefixed by colon,
-// followed by a space (": "). For example:
-//
-//   attributes.go:13:1: expected 'package', found 'type'
-//
-func errorSpan(err Error) span.Span {
-	if err.Pos == "" {
-		input := strings.TrimSpace(err.Msg)
-		msgIndex := strings.Index(input, ": ")
-		if msgIndex < 0 {
-			return span.Parse(input)
-		}
-		return span.Parse(input[:msgIndex])
-	}
-	return span.Parse(err.Pos)
-}
-
-// 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")
-	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{
-		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,
-		})
-	}
-	// 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:]
-			}
-		}
-	}
-	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;
@@ -730,10 +399,9 @@ 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
+// createDriverResponse uses the "go list" command to expand the pattern
-// words and return metadata for the specified packages. dir may be
+// words and return a response for the specified packages.
-// "" and env may be nil, as per os/exec.Command.
+func (state *golistState) createDriverResponse(words ...string) (*driverResponse, error) {
-func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driverResponse, error) {
 	// go list uses the following identifiers in ImportPath and Imports:
 	//
 	// 	"p"			-- importable package or main (command)
@@ -747,7 +415,7 @@ 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
 	}
@@ -782,7 +450,10 @@ 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
 			}
@@ -803,6 +474,7 @@ 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,
 		}
 
 		// Work around https://golang.org/issue/28749:
@@ -879,9 +551,15 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 		}
 
 		if p.Error != nil {
+			msg := strings.TrimSpace(p.Error.Err) // Trim to work around golang.org/issue/32363.
+			// Address golang.org/issue/35964 by appending import stack to error message.
+			if msg == "import cycle not allowed" && len(p.Error.ImportStack) != 0 {
+				msg += fmt.Sprintf(": import stack: %v", p.Error.ImportStack)
+			}
 			pkg.Errors = append(pkg.Errors, Error{
 				Pos:  p.Error.Pos,
-				Msg: strings.TrimSpace(p.Error.Err), // Trim to work around golang.org/issue/32363.
+				Msg:  msg,
+				Kind: ListError,
 			})
 		}
 
@@ -892,22 +570,20 @@ func golistDriver(cfg *Config, rootsDirs func() *goInfo, words ...string) (*driv
 }
 
 // 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, err
-		return "", false
 	}
-	for rdir, rpath := range goInfo().rootDirs {
+	roots, err := state.determineRootDirs()
-		absRdir, err := filepath.Abs(rdir)
 	if err != nil {
-			cfg.Logf("error getting absolute path of %s: %v", rdir, err)
+		return "", false, err
-			continue
 	}
+
+	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) {
+		if !strings.HasPrefix(absDir, rdir) {
-			cfg.Logf("%s does not have prefix %s", absDir, absRdir)
 			continue
 		}
 		// TODO(matloob): This doesn't properly handle symlinks.
@@ -922,11 +598,11 @@ 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.
@@ -945,8 +621,8 @@ 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",
+		"-e", "-json",
-		fmt.Sprintf("-compiled=%t", cfg.Mode&(NeedCompiledGoFiles|NeedSyntax|NeedTypesInfo|NeedTypesSizes) != 0),
+		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),
@@ -961,10 +637,17 @@ 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) {
+func (state *golistState) invokeGo(verb string, args ...string) (*bytes.Buffer, error) {
+	cfg := state.cfg
+
 	stdout := new(bytes.Buffer)
 	stderr := new(bytes.Buffer)
-	cmd := exec.CommandContext(cfg.Context, "go", args...)
+	goArgs := []string{verb}
+	if verb != "env" {
+		goArgs = append(goArgs, cfg.BuildFlags...)
+	}
+	goArgs = append(goArgs, args...)
+	cmd := exec.CommandContext(state.ctx, "go", goArgs...)
 	// 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.
@@ -976,7 +659,7 @@ func invokeGo(cfg *Config, args ...string) (*bytes.Buffer, error) {
 	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)
+		cfg.Logf("%s for %v, stderr: <<%s>> stdout: <<%s>>\n", time.Since(start), cmdDebugStr(cmd, goArgs...), stderr, stdout)
 	}(time.Now())
 
 	if err := cmd.Run(); err != nil {

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 := pkg.Imports[imp]; found {
-			if !found {
+				continue
+			}
 			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
+				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 wel.
+			// Add dependencies to the non-test variant version of this package as well.
 			if testVariantOf != nil {
 				testVariantOf.Imports[imp] = &Package{ID: id}
 			}
 		}
 	}
-		continue
+
+	// 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 state.resolveImport(sourceDir, id)
 	}
 
-	// toPkgPath tries to guess the package path given the id.
+	// Now that new packages have been created, do another pass to determine
-	// This isn't always correct -- it's certainly wrong for
+	// the new set of missing packages.
-	// vendored packages' paths.
-	toPkgPath := func(id string) string {
-		// TODO(matloob): Handle vendor paths.
-		i := strings.IndexByte(id, ' ')
-		if i >= 0 {
-			return id[:i]
-		}
-		return id
-	}
-
-	// Do another pass now that new packages have been created to determine the
-	// 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
+// determineRootDirs returns a mapping from absolute directories that could
-// corresponding import path prefixes of those directories.
+// contain code to their corresponding import path prefixes.
-// Its result is used to try to determine the import path for a package containing
+func (state *golistState) determineRootDirs() (map[string]string, error) {
-// an overlay file.
+	env, err := state.getEnv()
-func determineRootDirs(cfg *Config) map[string]string {
-	// Assume modules first:
-	out, err := invokeGo(cfg, "list", "-m", "-json", "all")
 	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")
+	for _, dir := range filepath.SplitList(state.mustGetEnv()["GOPATH"]) {
+		absDir, err := filepath.Abs(dir)
 		if err != nil {
-		// Could not determine root dir mapping. Everything is best-effort, so just return an empty map.
+			return nil, err
-		// 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(absDir, "src")] = ""
-		m[filepath.Join(p, "src")] = ""
 	}
-	return m
+	return m, nil
 }
 
 func extractImports(filename string, contents []byte) ([]string, error) {

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.
@@ -292,6 +296,15 @@ 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
+}
+
+func init() {
+	packagesinternal.GetForTest = func(p interface{}) string {
+		return p.(*Package).forTest
+	}
 }
 
 // An Error describes a problem with a package's metadata, syntax, or types.
@@ -500,12 +513,23 @@ 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,
+			needtypes: needtypes,
-			needsrc: (ld.Mode&(NeedSyntax|NeedTypesInfo) != 0 && ld.Mode&NeedDeps != 0 && rootIndex < 0) || rootIndex >= 0 ||
+			needsrc:   needsrc,
-				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",
 		}
 		ld.pkgs[lpkg.ID] = lpkg
 		if rootIndex >= 0 {
@@ -713,7 +737,7 @@ 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 {

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

@@ -4,6 +4,7 @@ package imports // import "golang.org/x/tools/imports"
 
 import (
 	"go/build"
+	"os"
 
 	intimp "golang.org/x/tools/internal/imports"
 )
@@ -42,6 +43,10 @@ func Process(filename string, src []byte, opt *Options) ([]byte, error) {
 		Env: &intimp.ProcessEnv{
 			GOPATH:      build.Default.GOPATH,
 			GOROOT:      build.Default.GOROOT,
+			GOFLAGS:     os.Getenv("GOFLAGS"),
+			GO111MODULE: os.Getenv("GO111MODULE"),
+			GOPROXY:     os.Getenv("GOPROXY"),
+			GOSUMDB:     os.Getenv("GOSUMDB"),
 			Debug:       Debug,
 			LocalPrefix: LocalPrefix,
 		},

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

@@ -14,14 +14,14 @@ import (
 	"sync"
 )
 
-// TraverseLink is used as a return value from WalkFuncs to indicate that the
+// ErrTraverseLink 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")
+var ErrTraverseLink = errors.New("fastwalk: traverse symlink, assuming target is a directory")
 
-// SkipFiles is a used as a return value from WalkFuncs to indicate that the
+// ErrSkipFiles 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")
+var ErrSkipFiles = errors.New("fastwalk: skip remaining files in directory")
 
 // Walk is a faster implementation of filepath.Walk.
 //
@@ -167,7 +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 == ErrTraverseLink {
 			// 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_portable.go

@@ -26,7 +26,7 @@ func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) e
 			continue
 		}
 		if err := fn(dirName, fi.Name(), fi.Mode()&os.ModeType); err != nil {
-			if err == SkipFiles {
+			if err == ErrSkipFiles {
 				skipFiles = true
 				continue
 			}

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

@@ -66,7 +66,7 @@ func readDir(dirName string, fn func(dirName, entName string, typ os.FileMode) e
 			continue
 		}
 		if err := fn(dirName, name, typ); err != nil {
-			if err == SkipFiles {
+			if err == ErrSkipFiles {
 				skipFiles = true
 				continue
 			}

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

@@ -77,6 +77,7 @@ func WalkSkip(roots []Root, add func(root Root, dir string), skip func(root Root
 	}
 }
 
+// walkDir creates a walker and starts fastwalk with this walker.
 func walkDir(root Root, add func(Root, string), skip func(root Root, dir string) bool, opts Options) {
 	if _, err := os.Stat(root.Path); os.IsNotExist(err) {
 		if opts.Debug {
@@ -114,7 +115,7 @@ type walker struct {
 	ignoredDirs []os.FileInfo // The ignored directories, loaded from .goimportsignore files.
 }
 
-// init initializes the walker based on its Options.
+// init initializes the walker based on its Options
 func (w *walker) init() {
 	var ignoredPaths []string
 	if w.root.Type == RootModuleCache {
@@ -167,6 +168,7 @@ func (w *walker) getIgnoredDirs(path string) []string {
 	return ignoredDirs
 }
 
+// shouldSkipDir reports whether the file should be skipped or not.
 func (w *walker) shouldSkipDir(fi os.FileInfo, dir string) bool {
 	for _, ignoredDir := range w.ignoredDirs {
 		if os.SameFile(fi, ignoredDir) {
@@ -180,20 +182,21 @@ func (w *walker) shouldSkipDir(fi os.FileInfo, dir string) bool {
 	return false
 }
 
+// walk walks through the given path.
 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
+			return fastwalk.ErrSkipFiles
 		}
 		if !strings.HasSuffix(path, ".go") {
 			return nil
 		}
 
 		w.add(w.root, dir)
-		return fastwalk.SkipFiles
+		return fastwalk.ErrSkipFiles
 	}
 	if typ == os.ModeDir {
 		base := filepath.Base(path)
@@ -221,7 +224,7 @@ func (w *walker) walk(path string, typ os.FileMode) error {
 			return nil
 		}
 		if w.shouldTraverse(dir, fi) {
-			return fastwalk.TraverseLink
+			return fastwalk.ErrTraverseLink
 		}
 	}
 	return nil

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

@@ -27,7 +27,6 @@ import (
 	"unicode/utf8"
 
 	"golang.org/x/tools/go/ast/astutil"
-	"golang.org/x/tools/go/packages"
 	"golang.org/x/tools/internal/gopathwalk"
 )
 
@@ -83,6 +82,7 @@ type ImportFix struct {
 	IdentName string
 	// FixType is the type of fix this is (AddImport, DeleteImport, SetImportName).
 	FixType   ImportFixType
+	Relevance int // see pkg
 }
 
 // An ImportInfo represents a single import statement.
@@ -585,62 +585,86 @@ func getFixes(fset *token.FileSet, f *ast.File, filename string, env *ProcessEnv
 	return fixes, nil
 }
 
-// getCandidatePkgs returns the list of pkgs that are accessible from filename,
+// Highest relevance, used for the standard library. Chosen arbitrarily to
-// optionall filtered to only packages named pkgName.
+// match pre-existing gopls code.
-func getCandidatePkgs(pkgName, filename string, env *ProcessEnv) ([]*pkg, error) {
+const MaxRelevance = 7
-	// TODO(heschi): filter out current package. (Don't forget x_test can import x.)
 
-	var result []*pkg
+// getCandidatePkgs works with the passed callback to find all acceptable packages.
-	// Start off with the standard library.
+// It deduplicates by import path, and uses a cached stdlib rather than reading
-	for importPath := range stdlib {
+// from disk.
-		if pkgName != "" && path.Base(importPath) != pkgName {
+func getCandidatePkgs(ctx context.Context, wrappedCallback *scanCallback, filename, filePkg string, env *ProcessEnv) error {
-			continue
+	notSelf := func(p *pkg) bool {
+		return p.packageName != filePkg || p.dir != filepath.Dir(filename)
 	}
-		result = append(result, &pkg{
+	// Start off with the standard library.
+	for importPath, exports := range stdlib {
+		p := &pkg{
 			dir:             filepath.Join(env.GOROOT, "src", importPath),
 			importPathShort: importPath,
 			packageName:     path.Base(importPath),
-			relevance:       0,
+			relevance:       MaxRelevance,
-		})
+		}
+		if notSelf(p) && wrappedCallback.packageNameLoaded(p) {
+			wrappedCallback.exportsLoaded(p, exports)
+		}
 	}
 
+	var mu sync.Mutex
+	dupCheck := map[string]struct{}{}
+
+	scanFilter := &scanCallback{
+		rootFound: func(root gopathwalk.Root) bool {
 			// Exclude goroot results -- getting them is relatively expensive, not cached,
 			// and generally redundant with the in-memory version.
-	exclude := []gopathwalk.RootType{gopathwalk.RootGOROOT}
+			return root.Type != gopathwalk.RootGOROOT && wrappedCallback.rootFound(root)
-	// Only the go/packages resolver uses the first argument, and nobody uses that resolver.
+		},
-	scannedPkgs, err := env.GetResolver().scan(nil, true, exclude)
+		dirFound: wrappedCallback.dirFound,
-	if err != nil {
+		packageNameLoaded: func(pkg *pkg) bool {
-		return nil, err
+			mu.Lock()
-	}
+			defer mu.Unlock()
-
-	dupCheck := map[string]struct{}{}
-	for _, pkg := range scannedPkgs {
-		if pkgName != "" && pkg.packageName != pkgName {
-			continue
-		}
-		if !canUse(filename, pkg.dir) {
-			continue
-		}
 			if _, ok := dupCheck[pkg.importPathShort]; ok {
-			continue
+				return false
 			}
 			dupCheck[pkg.importPathShort] = struct{}{}
-		result = append(result, pkg)
+			return notSelf(pkg) && wrappedCallback.packageNameLoaded(pkg)
+		},
+		exportsLoaded: func(pkg *pkg, exports []string) {
+			// If we're an x_test, load the package under test's test variant.
+			if strings.HasSuffix(filePkg, "_test") && pkg.dir == filepath.Dir(filename) {
+				var err error
+				_, exports, err = loadExportsFromFiles(ctx, env, pkg.dir, true)
+				if err != nil {
+					return
 				}
+			}
+			wrappedCallback.exportsLoaded(pkg, exports)
+		},
+	}
+	return env.GetResolver().scan(ctx, scanFilter)
+}
 
-	// Sort first by relevance, then by package name, with import path as a tiebreaker.
+func ScoreImportPaths(ctx context.Context, env *ProcessEnv, paths []string) map[string]int {
-	sort.Slice(result, func(i, j int) bool {
+	result := make(map[string]int)
-		pi, pj := result[i], result[j]
+	for _, path := range paths {
-		if pi.relevance != pj.relevance {
+		result[path] = env.GetResolver().scoreImportPath(ctx, path)
-			return pi.relevance < pj.relevance
 	}
-		if pi.packageName != pj.packageName {
+	return result
-			return pi.packageName < pj.packageName
+}
-		}
-		return pi.importPathShort < pj.importPathShort
-	})
 
-	return result, nil
+func PrimeCache(ctx context.Context, env *ProcessEnv) error {
+	// Fully scan the disk for directories, but don't actually read any Go files.
+	callback := &scanCallback{
+		rootFound: func(gopathwalk.Root) bool {
+			return true
+		},
+		dirFound: func(pkg *pkg) bool {
+			return false
+		},
+		packageNameLoaded: func(pkg *pkg) bool {
+			return false
+		},
+	}
+	return getCandidatePkgs(ctx, callback, "", "", env)
 }
 
 func candidateImportName(pkg *pkg) string {
@@ -651,23 +675,37 @@ func candidateImportName(pkg *pkg) string {
 }
 
 // getAllCandidates gets all of the candidates to be imported, regardless of if they are needed.
-func getAllCandidates(filename string, env *ProcessEnv) ([]ImportFix, error) {
+func getAllCandidates(ctx context.Context, wrapped func(ImportFix), searchPrefix, filename, filePkg string, env *ProcessEnv) error {
-	pkgs, err := getCandidatePkgs("", filename, env)
+	callback := &scanCallback{
-	if err != nil {
+		rootFound: func(gopathwalk.Root) bool {
-		return nil, err
+			return true
+		},
+		dirFound: func(pkg *pkg) bool {
+			if !canUse(filename, pkg.dir) {
+				return false
 			}
-	result := make([]ImportFix, 0, len(pkgs))
+			// Try the assumed package name first, then a simpler path match
-	for _, pkg := range pkgs {
+			// in case of packages named vN, which are not uncommon.
-		result = append(result, ImportFix{
+			return strings.HasPrefix(ImportPathToAssumedName(pkg.importPathShort), searchPrefix) ||
+				strings.HasPrefix(path.Base(pkg.importPathShort), searchPrefix)
+		},
+		packageNameLoaded: func(pkg *pkg) bool {
+			if !strings.HasPrefix(pkg.packageName, searchPrefix) {
+				return false
+			}
+			wrapped(ImportFix{
 				StmtInfo: ImportInfo{
 					ImportPath: pkg.importPathShort,
 					Name:       candidateImportName(pkg),
 				},
 				IdentName: pkg.packageName,
 				FixType:   AddImport,
+				Relevance: pkg.relevance,
 			})
+			return false
+		},
 	}
-	return result, nil
+	return getCandidatePkgs(ctx, callback, filename, filePkg, env)
 }
 
 // A PackageExport is a package and its exports.
@@ -676,42 +714,34 @@ type PackageExport struct {
 	Exports []string
 }
 
-func getPackageExports(completePackage, filename string, env *ProcessEnv) ([]PackageExport, error) {
+func getPackageExports(ctx context.Context, wrapped func(PackageExport), searchPkg, filename, filePkg string, env *ProcessEnv) error {
-	pkgs, err := getCandidatePkgs(completePackage, filename, env)
+	callback := &scanCallback{
-	if err != nil {
+		rootFound: func(gopathwalk.Root) bool {
-		return nil, err
+			return true
-	}
+		},
-
+		dirFound: func(pkg *pkg) bool {
-	results := make([]PackageExport, 0, len(pkgs))
+			return pkgIsCandidate(filename, references{searchPkg: nil}, pkg)
-	for _, pkg := range pkgs {
+		},
-		fix := &ImportFix{
+		packageNameLoaded: func(pkg *pkg) bool {
+			return pkg.packageName == searchPkg
+		},
+		exportsLoaded: func(pkg *pkg, exports []string) {
+			sort.Strings(exports)
+			wrapped(PackageExport{
+				Fix: &ImportFix{
 					StmtInfo: ImportInfo{
 						ImportPath: pkg.importPathShort,
 						Name:       candidateImportName(pkg),
 					},
 					IdentName: pkg.packageName,
 					FixType:   AddImport,
-		}
+					Relevance: pkg.relevance,
-		var exports []string
+				},
-		if e, ok := stdlib[pkg.importPathShort]; ok {
-			exports = e
-		} else {
-			exports, err = loadExportsForPackage(context.Background(), env, completePackage, pkg)
-			if err != nil {
-				if env.Debug {
-					env.Logf("while completing %q, error loading exports from %q: %v", completePackage, pkg.importPathShort, err)
-				}
-				continue
-			}
-		}
-		sort.Strings(exports)
-		results = append(results, PackageExport{
-			Fix:     fix,
 				Exports: exports,
 			})
+		},
 	}
-
+	return getCandidatePkgs(ctx, callback, filename, filePkg, env)
-	return results, nil
 }
 
 // ProcessEnv contains environment variables and settings that affect the use of
@@ -725,15 +755,19 @@ type ProcessEnv struct {
 	GOPATH, GOROOT, GO111MODULE, GOPROXY, GOFLAGS, GOSUMDB string
 	WorkingDir                                             string
 
-	// If true, use go/packages regardless of the environment.
-	ForceGoPackages bool
-
 	// Logf is the default logger for the ProcessEnv.
 	Logf func(format string, args ...interface{})
 
 	resolver Resolver
 }
 
+// CopyConfig copies the env's configuration into a new env.
+func (e *ProcessEnv) CopyConfig() *ProcessEnv {
+	copy := *e
+	copy.resolver = nil
+	return &copy
+}
+
 func (e *ProcessEnv) env() []string {
 	env := os.Environ()
 	add := func(k, v string) {
@@ -757,39 +791,34 @@ func (e *ProcessEnv) GetResolver() Resolver {
 	if e.resolver != nil {
 		return e.resolver
 	}
-	if e.ForceGoPackages {
-		e.resolver = &goPackagesResolver{env: e}
-		return e.resolver
-	}
-
 	out, err := e.invokeGo("env", "GOMOD")
 	if err != nil || len(bytes.TrimSpace(out.Bytes())) == 0 {
-		e.resolver = &gopathResolver{env: e}
+		e.resolver = newGopathResolver(e)
 		return e.resolver
 	}
-	e.resolver = &ModuleResolver{env: e}
+	e.resolver = newModuleResolver(e)
 	return e.resolver
 }
 
-func (e *ProcessEnv) newPackagesConfig(mode packages.LoadMode) *packages.Config {
-	return &packages.Config{
-		Mode: mode,
-		Dir:  e.WorkingDir,
-		Env:  e.env(),
-	}
-}
-
 func (e *ProcessEnv) buildContext() *build.Context {
 	ctx := build.Default
 	ctx.GOROOT = e.GOROOT
 	ctx.GOPATH = e.GOPATH
 
-	// As of Go 1.14, build.Context has a WorkingDir field
+	// As of Go 1.14, build.Context has a Dir field
 	// (see golang.org/issue/34860).
 	// Populate it only if present.
-	if wd := reflect.ValueOf(&ctx).Elem().FieldByName("WorkingDir"); wd.IsValid() && wd.Kind() == reflect.String {
+	rc := reflect.ValueOf(&ctx).Elem()
-		wd.SetString(e.WorkingDir)
+	dir := rc.FieldByName("Dir")
+	if !dir.IsValid() {
+		// Working drafts of Go 1.14 named the field "WorkingDir" instead.
+		// TODO(bcmills): Remove this case after the Go 1.14 beta has been released.
+		dir = rc.FieldByName("WorkingDir")
 	}
+	if dir.IsValid() && dir.Kind() == reflect.String {
+		dir.SetString(e.WorkingDir)
+	}
+
 	return &ctx
 }
 
@@ -848,94 +877,65 @@ func addStdlibCandidates(pass *pass, refs references) {
 type Resolver interface {
 	// loadPackageNames loads the package names in importPaths.
 	loadPackageNames(importPaths []string, srcDir string) (map[string]string, error)
-	// scan finds (at least) the packages satisfying refs. If loadNames is true,
+	// scan works with callback to search for packages. See scanCallback for details.
-	// package names will be set on the results, and dirs whose package name
+	scan(ctx context.Context, callback *scanCallback) error
-	// could not be determined will be excluded.
-	scan(refs references, loadNames bool, exclude []gopathwalk.RootType) ([]*pkg, error)
 	// loadExports returns the set of exported symbols in the package at dir.
 	// loadExports may be called concurrently.
-	loadExports(ctx context.Context, pkg *pkg) (string, []string, error)
+	loadExports(ctx context.Context, pkg *pkg, includeTest bool) (string, []string, error)
+	// scoreImportPath returns the relevance for an import path.
+	scoreImportPath(ctx context.Context, path string) int
 
 	ClearForNewScan()
 }
 
-// gopackagesResolver implements resolver for GOPATH and module workspaces using go/packages.
+// A scanCallback controls a call to scan and receives its results.
-type goPackagesResolver struct {
+// In general, minor errors will be silently discarded; a user should not
-	env *ProcessEnv
+// expect to receive a full series of calls for everything.
-}
+type scanCallback struct {
-
+	// rootFound is called before scanning a new root dir. If it returns true,
-func (r *goPackagesResolver) ClearForNewScan() {}
+	// the root will be scanned. Returning false will not necessarily prevent
-
+	// directories from that root making it to dirFound.
-func (r *goPackagesResolver) loadPackageNames(importPaths []string, srcDir string) (map[string]string, error) {
+	rootFound func(gopathwalk.Root) bool
-	if len(importPaths) == 0 {
+	// dirFound is called when a directory is found that is possibly a Go package.
-		return nil, nil
+	// pkg will be populated with everything except packageName.
-	}
+	// If it returns true, the package's name will be loaded.
-	cfg := r.env.newPackagesConfig(packages.LoadFiles)
+	dirFound func(pkg *pkg) bool
-	pkgs, err := packages.Load(cfg, importPaths...)
+	// packageNameLoaded is called when a package is found and its name is loaded.
-	if err != nil {
+	// If it returns true, the package's exports will be loaded.
-		return nil, err
+	packageNameLoaded func(pkg *pkg) bool
-	}
+	// exportsLoaded is called when a package's exports have been loaded.
-	names := map[string]string{}
+	exportsLoaded func(pkg *pkg, exports []string)
-	for _, pkg := range pkgs {
-		names[VendorlessPath(pkg.PkgPath)] = pkg.Name
-	}
-	// We may not have found all the packages. Guess the rest.
-	for _, path := range importPaths {
-		if _, ok := names[path]; ok {
-			continue
-		}
-		names[path] = ImportPathToAssumedName(path)
-	}
-	return names, nil
-
-}
-
-func (r *goPackagesResolver) scan(refs references, _ bool, _ []gopathwalk.RootType) ([]*pkg, error) {
-	var loadQueries []string
-	for pkgName := range refs {
-		loadQueries = append(loadQueries, "iamashamedtousethedisabledqueryname="+pkgName)
-	}
-	sort.Strings(loadQueries)
-	cfg := r.env.newPackagesConfig(packages.LoadFiles)
-	goPackages, err := packages.Load(cfg, loadQueries...)
-	if err != nil {
-		return nil, err
-	}
-
-	var scan []*pkg
-	for _, goPackage := range goPackages {
-		scan = append(scan, &pkg{
-			dir:             filepath.Dir(goPackage.CompiledGoFiles[0]),
-			importPathShort: VendorlessPath(goPackage.PkgPath),
-			goPackage:       goPackage,
-			packageName:     goPackage.Name,
-		})
-	}
-	return scan, nil
-}
-
-func (r *goPackagesResolver) loadExports(ctx context.Context, pkg *pkg) (string, []string, error) {
-	if pkg.goPackage == nil {
-		return "", nil, fmt.Errorf("goPackage not set")
-	}
-	var exports []string
-	fset := token.NewFileSet()
-	for _, fname := range pkg.goPackage.CompiledGoFiles {
-		f, err := parser.ParseFile(fset, fname, nil, 0)
-		if err != nil {
-			return "", nil, fmt.Errorf("parsing %s: %v", fname, err)
-		}
-		for name := range f.Scope.Objects {
-			if ast.IsExported(name) {
-				exports = append(exports, name)
-			}
-		}
-	}
-	return pkg.goPackage.Name, exports, nil
 }
 
 func addExternalCandidates(pass *pass, refs references, filename string) error {
-	dirScan, err := pass.env.GetResolver().scan(refs, false, nil)
+	var mu sync.Mutex
+	found := make(map[string][]pkgDistance)
+	callback := &scanCallback{
+		rootFound: func(gopathwalk.Root) bool {
+			return true // We want everything.
+		},
+		dirFound: func(pkg *pkg) bool {
+			return pkgIsCandidate(filename, refs, pkg)
+		},
+		packageNameLoaded: func(pkg *pkg) bool {
+			if _, want := refs[pkg.packageName]; !want {
+				return false
+			}
+			if pkg.dir == pass.srcDir && pass.f.Name.Name == pkg.packageName {
+				// The candidate is in the same directory and has the
+				// same package name. Don't try to import ourselves.
+				return false
+			}
+			if !canUse(filename, pkg.dir) {
+				return false
+			}
+			mu.Lock()
+			defer mu.Unlock()
+			found[pkg.packageName] = append(found[pkg.packageName], pkgDistance{pkg, distance(pass.srcDir, pkg.dir)})
+			return false // We'll do our own loading after we sort.
+		},
+	}
+	err := pass.env.GetResolver().scan(context.Background(), callback)
 	if err != nil {
 		return err
 	}
@@ -962,7 +962,7 @@ func addExternalCandidates(pass *pass, refs references, filename string) error {
 		go func(pkgName string, symbols map[string]bool) {
 			defer wg.Done()
 
-			found, err := findImport(ctx, pass, dirScan, pkgName, symbols, filename)
+			found, err := findImport(ctx, pass, found[pkgName], pkgName, symbols, filename)
 
 			if err != nil {
 				firstErrOnce.Do(func() {
@@ -1034,23 +1034,35 @@ func ImportPathToAssumedName(importPath string) string {
 // gopathResolver implements resolver for GOPATH workspaces.
 type gopathResolver struct {
 	env      *ProcessEnv
+	walked   bool
 	cache    *dirInfoCache
+	scanSema chan struct{} // scanSema prevents concurrent scans.
 }
 
-func (r *gopathResolver) init() {
+func newGopathResolver(env *ProcessEnv) *gopathResolver {
-	if r.cache == nil {
+	r := &gopathResolver{
-		r.cache = &dirInfoCache{
+		env: env,
+		cache: &dirInfoCache{
 			dirs:      map[string]*directoryPackageInfo{},
+			listeners: map[*int]cacheListener{},
+		},
+		scanSema: make(chan struct{}, 1),
 	}
-	}
+	r.scanSema <- struct{}{}
+	return r
 }
 
 func (r *gopathResolver) ClearForNewScan() {
-	r.cache = nil
+	<-r.scanSema
+	r.cache = &dirInfoCache{
+		dirs:      map[string]*directoryPackageInfo{},
+		listeners: map[*int]cacheListener{},
+	}
+	r.walked = false
+	r.scanSema <- struct{}{}
 }
 
 func (r *gopathResolver) loadPackageNames(importPaths []string, srcDir string) (map[string]string, error) {
-	r.init()
 	names := map[string]string{}
 	for _, path := range importPaths {
 		names[path] = importPathToName(r.env, path, srcDir)
@@ -1130,7 +1142,6 @@ func packageDirToName(dir string) (packageName string, err error) {
 }
 
 type pkg struct {
-	goPackage       *packages.Package
 	dir             string // absolute file path to pkg directory ("/usr/lib/go/src/net/http")
 	importPathShort string // vendorless import path ("net/http", "a/b")
 	packageName     string // package name loaded from source if requested
@@ -1178,8 +1189,7 @@ func distance(basepath, targetpath string) int {
 	return strings.Count(p, string(filepath.Separator)) + 1
 }
 
-func (r *gopathResolver) scan(_ references, loadNames bool, exclude []gopathwalk.RootType) ([]*pkg, error) {
+func (r *gopathResolver) scan(ctx context.Context, callback *scanCallback) error {
-	r.init()
 	add := func(root gopathwalk.Root, dir string) {
 		// We assume cached directories have not changed. We can skip them and their
 		// children.
@@ -1196,56 +1206,84 @@ func (r *gopathResolver) scan(_ references, loadNames bool, exclude []gopathwalk
 		}
 		r.cache.Store(dir, info)
 	}
-	roots := filterRoots(gopathwalk.SrcDirsRoots(r.env.buildContext()), exclude)
+	processDir := func(info directoryPackageInfo) {
-	gopathwalk.Walk(roots, add, gopathwalk.Options{Debug: r.env.Debug, ModulesEnabled: false})
+		// Skip this directory if we were not able to get the package information successfully.
-	var result []*pkg
+		if scanned, err := info.reachedStatus(directoryScanned); !scanned || err != nil {
-	for _, dir := range r.cache.Keys() {
+			return
-		info, ok := r.cache.Load(dir)
-		if !ok {
-			continue
-		}
-		if loadNames {
-			var err error
-			info, err = r.cache.CachePackageName(info)
-			if err != nil {
-				continue
-			}
 		}
 
 		p := &pkg{
 			importPathShort: info.nonCanonicalImportPath,
-			dir:             dir,
+			dir:             info.dir,
-			relevance:       1,
+			relevance:       MaxRelevance - 1,
-			packageName:     info.packageName,
 		}
 		if info.rootType == gopathwalk.RootGOROOT {
-			p.relevance = 0
+			p.relevance = MaxRelevance
 		}
-		result = append(result, p)
+
+		if !callback.dirFound(p) {
+			return
 		}
-	return result, nil
+		var err error
+		p.packageName, err = r.cache.CachePackageName(info)
+		if err != nil {
+			return
+		}
+
+		if !callback.packageNameLoaded(p) {
+			return
+		}
+		if _, exports, err := r.loadExports(ctx, p, false); err == nil {
+			callback.exportsLoaded(p, exports)
+		}
+	}
+	stop := r.cache.ScanAndListen(ctx, processDir)
+	defer stop()
+	// The callback is not necessarily safe to use in the goroutine below. Process roots eagerly.
+	roots := filterRoots(gopathwalk.SrcDirsRoots(r.env.buildContext()), callback.rootFound)
+	// We can't cancel walks, because we need them to finish to have a usable
+	// cache. Instead, run them in a separate goroutine and detach.
+	scanDone := make(chan struct{})
+	go func() {
+		select {
+		case <-ctx.Done():
+			return
+		case <-r.scanSema:
+		}
+		defer func() { r.scanSema <- struct{}{} }()
+		gopathwalk.Walk(roots, add, gopathwalk.Options{Debug: r.env.Debug, ModulesEnabled: false})
+		close(scanDone)
+	}()
+	select {
+	case <-ctx.Done():
+	case <-scanDone:
+	}
+	return nil
 }
 
-func filterRoots(roots []gopathwalk.Root, exclude []gopathwalk.RootType) []gopathwalk.Root {
+func (r *gopathResolver) scoreImportPath(ctx context.Context, path string) int {
-	var result []gopathwalk.Root
+	if _, ok := stdlib[path]; ok {
-outer:
+		return MaxRelevance
-	for _, root := range roots {
-		for _, i := range exclude {
-			if i == root.Type {
-				continue outer
 	}
+	return MaxRelevance - 1
+}
+
+func filterRoots(roots []gopathwalk.Root, include func(gopathwalk.Root) bool) []gopathwalk.Root {
+	var result []gopathwalk.Root
+	for _, root := range roots {
+		if !include(root) {
+			continue
 		}
 		result = append(result, root)
 	}
 	return result
 }
 
-func (r *gopathResolver) loadExports(ctx context.Context, pkg *pkg) (string, []string, error) {
+func (r *gopathResolver) loadExports(ctx context.Context, pkg *pkg, includeTest bool) (string, []string, error) {
-	r.init()
+	if info, ok := r.cache.Load(pkg.dir); ok && !includeTest {
-	if info, ok := r.cache.Load(pkg.dir); ok {
 		return r.cache.CacheExports(ctx, r.env, info)
 	}
-	return loadExportsFromFiles(ctx, r.env, pkg.dir)
+	return loadExportsFromFiles(ctx, r.env, pkg.dir, includeTest)
 }
 
 // VendorlessPath returns the devendorized version of the import path ipath.
@@ -1261,7 +1299,7 @@ func VendorlessPath(ipath string) string {
 	return ipath
 }
 
-func loadExportsFromFiles(ctx context.Context, env *ProcessEnv, dir string) (string, []string, error) {
+func loadExportsFromFiles(ctx context.Context, env *ProcessEnv, dir string, includeTest bool) (string, []string, error) {
 	var exports []string
 
 	// Look for non-test, buildable .go files which could provide exports.
@@ -1272,7 +1310,7 @@ func loadExportsFromFiles(ctx context.Context, env *ProcessEnv, dir string) (str
 	var files []os.FileInfo
 	for _, fi := range all {
 		name := fi.Name()
-		if !strings.HasSuffix(name, ".go") || strings.HasSuffix(name, "_test.go") {
+		if !strings.HasSuffix(name, ".go") || (!includeTest && strings.HasSuffix(name, "_test.go")) {
 			continue
 		}
 		match, err := env.buildContext().MatchFile(dir, fi.Name())
@@ -1305,6 +1343,10 @@ func loadExportsFromFiles(ctx context.Context, env *ProcessEnv, dir string) (str
 			// handled by MatchFile above.
 			continue
 		}
+		if includeTest && strings.HasSuffix(f.Name.Name, "_test") {
+			// x_test package. We want internal test files only.
+			continue
+		}
 		pkgName = f.Name.Name
 		for name := range f.Scope.Objects {
 			if ast.IsExported(name) {
@@ -1323,29 +1365,7 @@ func loadExportsFromFiles(ctx context.Context, env *ProcessEnv, dir string) (str
 
 // findImport searches for a package with the given symbols.
 // If no package is found, findImport returns ("", false, nil)
-func findImport(ctx context.Context, pass *pass, dirScan []*pkg, pkgName string, symbols map[string]bool, filename string) (*pkg, error) {
+func findImport(ctx context.Context, pass *pass, candidates []pkgDistance, pkgName string, symbols map[string]bool, filename string) (*pkg, error) {
-	pkgDir, err := filepath.Abs(filename)
-	if err != nil {
-		return nil, err
-	}
-	pkgDir = filepath.Dir(pkgDir)
-
-	// Find candidate packages, looking only at their directory names first.
-	var candidates []pkgDistance
-	for _, pkg := range dirScan {
-		if pkg.dir == pkgDir && pass.f.Name.Name == pkgName {
-			// The candidate is in the same directory and has the
-			// same package name. Don't try to import ourselves.
-			continue
-		}
-		if pkgIsCandidate(filename, pkgName, pkg) {
-			candidates = append(candidates, pkgDistance{
-				pkg:      pkg,
-				distance: distance(pkgDir, pkg.dir),
-			})
-		}
-	}
-
 	// Sort the candidates by their import package length,
 	// assuming that shorter package names are better than long
 	// ones.  Note that this sorts by the de-vendored name, so
@@ -1358,7 +1378,6 @@ func findImport(ctx context.Context, pass *pass, dirScan []*pkg, pkgName string,
 	}
 
 	// Collect exports for packages with matching names.
-
 	rescv := make([]chan *pkg, len(candidates))
 	for i := range candidates {
 		rescv[i] = make(chan *pkg, 1)
@@ -1393,7 +1412,9 @@ func findImport(ctx context.Context, pass *pass, dirScan []*pkg, pkgName string,
 				if pass.env.Debug {
 					pass.env.Logf("loading exports in dir %s (seeking package %s)", c.pkg.dir, pkgName)
 				}
-				exports, err := loadExportsForPackage(ctx, pass.env, pkgName, c.pkg)
+				// If we're an x_test, load the package under test's test variant.
+				includeTest := strings.HasSuffix(pass.f.Name.Name, "_test") && c.pkg.dir == pass.srcDir
+				_, exports, err := pass.env.GetResolver().loadExports(ctx, c.pkg, includeTest)
 				if err != nil {
 					if pass.env.Debug {
 						pass.env.Logf("loading exports in dir %s (seeking package %s): %v", c.pkg.dir, pkgName, err)
@@ -1430,17 +1451,6 @@ func findImport(ctx context.Context, pass *pass, dirScan []*pkg, pkgName string,
 	return nil, nil
 }
 
-func loadExportsForPackage(ctx context.Context, env *ProcessEnv, expectPkg string, pkg *pkg) ([]string, error) {
-	pkgName, exports, err := env.GetResolver().loadExports(ctx, pkg)
-	if err != nil {
-		return nil, err
-	}
-	if expectPkg != pkgName {
-		return nil, fmt.Errorf("dir %v is package %v, wanted %v", pkg.dir, pkgName, expectPkg)
-	}
-	return exports, err
-}
-
 // pkgIsCandidate reports whether pkg is a candidate for satisfying the
 // finding which package pkgIdent in the file named by filename is trying
 // to refer to.
@@ -1453,7 +1463,7 @@ func loadExportsForPackage(ctx context.Context, env *ProcessEnv, expectPkg strin
 // filename is the file being formatted.
 // pkgIdent is the package being searched for, like "client" (if
 // searching for "client.New")
-func pkgIsCandidate(filename, pkgIdent string, pkg *pkg) bool {
+func pkgIsCandidate(filename string, refs references, pkg *pkg) bool {
 	// Check "internal" and "vendor" visibility:
 	if !canUse(filename, pkg.dir) {
 		return false
@@ -1471,6 +1481,7 @@ func pkgIsCandidate(filename, pkgIdent string, pkg *pkg) bool {
 	// "bar", which is strongly discouraged
 	// anyway. There's no reason goimports needs
 	// to be slow just to accommodate that.
+	for pkgIdent := range refs {
 		lastTwo := lastTwoComponents(pkg.importPathShort)
 		if strings.Contains(lastTwo, pkgIdent) {
 			return true
@@ -1481,7 +1492,7 @@ func pkgIsCandidate(filename, pkgIdent string, pkg *pkg) bool {
 				return true
 			}
 		}
-
+	}
 	return false
 }
 

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

@@ -11,6 +11,7 @@ package imports
 import (
 	"bufio"
 	"bytes"
+	"context"
 	"fmt"
 	"go/ast"
 	"go/build"
@@ -21,6 +22,7 @@ import (
 	"io"
 	"io/ioutil"
 	"log"
+	"os"
 	"regexp"
 	"strconv"
 	"strings"
@@ -83,42 +85,54 @@ func FixImports(filename string, src []byte, opt *Options) (fixes []*ImportFix,
 	return getFixes(fileSet, file, filename, opt.Env)
 }
 
-// ApplyFix will apply all of the fixes to the file and format it.
+// ApplyFixes applies all of the fixes to the file and formats it. extraMode
-func ApplyFixes(fixes []*ImportFix, filename string, src []byte, opt *Options) (formatted []byte, err error) {
+// is added in when parsing the file.
+func ApplyFixes(fixes []*ImportFix, filename string, src []byte, opt *Options, extraMode parser.Mode) (formatted []byte, err error) {
 	src, opt, err = initialize(filename, src, opt)
 	if err != nil {
 		return nil, err
 	}
 
+	// Don't use parse() -- we don't care about fragments or statement lists
+	// here, and we need to work with unparseable files.
 	fileSet := token.NewFileSet()
-	file, adjust, err := parse(fileSet, filename, src, opt)
+	parserMode := parser.Mode(0)
-	if err != nil {
+	if opt.Comments {
+		parserMode |= parser.ParseComments
+	}
+	if opt.AllErrors {
+		parserMode |= parser.AllErrors
+	}
+	parserMode |= extraMode
+
+	file, err := parser.ParseFile(fileSet, filename, src, parserMode)
+	if file == nil {
 		return nil, err
 	}
 
 	// Apply the fixes to the file.
 	apply(fileSet, file, fixes)
 
-	return formatFile(fileSet, file, src, adjust, opt)
+	return formatFile(fileSet, file, src, nil, opt)
 }
 
-// GetAllCandidates gets all of the standard library candidate packages to import in
+// GetAllCandidates gets all of the packages starting with prefix that can be
-// sorted order on import path.
+// imported by filename, sorted by import path.
-func GetAllCandidates(filename string, opt *Options) (pkgs []ImportFix, err error) {
+func GetAllCandidates(ctx context.Context, callback func(ImportFix), searchPrefix, filename, filePkg string, opt *Options) error {
-	_, opt, err = initialize(filename, nil, opt)
+	_, opt, err := initialize(filename, []byte{}, opt)
 	if err != nil {
-		return nil, err
+		return err
 	}
-	return getAllCandidates(filename, opt.Env)
+	return getAllCandidates(ctx, callback, searchPrefix, filename, filePkg, opt.Env)
 }
 
 // GetPackageExports returns all known packages with name pkg and their exports.
-func GetPackageExports(pkg, filename string, opt *Options) (exports []PackageExport, err error) {
+func GetPackageExports(ctx context.Context, callback func(PackageExport), searchPkg, filename, filePkg string, opt *Options) error {
-	_, opt, err = initialize(filename, nil, opt)
+	_, opt, err := initialize(filename, []byte{}, opt)
 	if err != nil {
-		return nil, err
+		return err
 	}
-	return getPackageExports(pkg, filename, opt.Env)
+	return getPackageExports(ctx, callback, searchPkg, filename, filePkg, opt.Env)
 }
 
 // initialize sets the values for opt and src.
@@ -135,6 +149,10 @@ func initialize(filename string, src []byte, opt *Options) ([]byte, *Options, er
 		opt.Env = &ProcessEnv{
 			GOPATH:      build.Default.GOPATH,
 			GOROOT:      build.Default.GOROOT,
+			GOFLAGS:     os.Getenv("GOFLAGS"),
+			GO111MODULE: os.Getenv("GO111MODULE"),
+			GOPROXY:     os.Getenv("GOPROXY"),
+			GOSUMDB:     os.Getenv("GOSUMDB"),
 		}
 	}
 

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

@@ -13,7 +13,6 @@ import (
 	"sort"
 	"strconv"
 	"strings"
-	"sync"
 
 	"golang.org/x/tools/internal/gopathwalk"
 	"golang.org/x/tools/internal/module"
@@ -26,11 +25,14 @@ type ModuleResolver struct {
 	env            *ProcessEnv
 	moduleCacheDir string
 	dummyVendorMod *ModuleJSON // If vendoring is enabled, the pseudo-module that represents the /vendor directory.
+	roots          []gopathwalk.Root
+	scanSema       chan struct{} // scanSema prevents concurrent scans and guards scannedRoots.
+	scannedRoots   map[gopathwalk.Root]bool
 
-	Initialized   bool
+	initialized   bool
-	Main          *ModuleJSON
+	main          *ModuleJSON
-	ModsByModPath []*ModuleJSON // All modules, ordered by # of path components in module Path...
+	modsByModPath []*ModuleJSON // All modules, ordered by # of path components in module Path...
-	ModsByDir     []*ModuleJSON // ...or Dir.
+	modsByDir     []*ModuleJSON // ...or Dir.
 
 	// moduleCacheCache stores information about the module cache.
 	moduleCacheCache *dirInfoCache
@@ -41,13 +43,23 @@ type ModuleJSON struct {
 	Path      string      // module path
 	Replace   *ModuleJSON // replaced by this module
 	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
 	GoVersion string      // go version used in module
 }
 
+func newModuleResolver(e *ProcessEnv) *ModuleResolver {
+	r := &ModuleResolver{
+		env:      e,
+		scanSema: make(chan struct{}, 1),
+	}
+	r.scanSema <- struct{}{}
+	return r
+}
+
 func (r *ModuleResolver) init() error {
-	if r.Initialized {
+	if r.initialized {
 		return nil
 	}
 	mainMod, vendorEnabled, err := vendorEnabled(r.env)
@@ -58,13 +70,13 @@ func (r *ModuleResolver) init() error {
 	if mainMod != nil && vendorEnabled {
 		// Vendor mode is on, so all the non-Main modules are irrelevant,
 		// and we need to search /vendor for everything.
-		r.Main = mainMod
+		r.main = mainMod
 		r.dummyVendorMod = &ModuleJSON{
 			Path: "",
 			Dir:  filepath.Join(mainMod.Dir, "vendor"),
 		}
-		r.ModsByModPath = []*ModuleJSON{mainMod, r.dummyVendorMod}
+		r.modsByModPath = []*ModuleJSON{mainMod, r.dummyVendorMod}
-		r.ModsByDir = []*ModuleJSON{mainMod, r.dummyVendorMod}
+		r.modsByDir = []*ModuleJSON{mainMod, r.dummyVendorMod}
 	} else {
 		// Vendor mode is off, so run go list -m ... to find everything.
 		r.initAllMods()
@@ -72,30 +84,64 @@ func (r *ModuleResolver) init() error {
 
 	r.moduleCacheDir = filepath.Join(filepath.SplitList(r.env.GOPATH)[0], "/pkg/mod")
 
-	sort.Slice(r.ModsByModPath, func(i, j int) bool {
+	sort.Slice(r.modsByModPath, func(i, j int) bool {
 		count := func(x int) int {
-			return strings.Count(r.ModsByModPath[x].Path, "/")
+			return strings.Count(r.modsByModPath[x].Path, "/")
 		}
 		return count(j) < count(i) // descending order
 	})
-	sort.Slice(r.ModsByDir, func(i, j int) bool {
+	sort.Slice(r.modsByDir, func(i, j int) bool {
 		count := func(x int) int {
-			return strings.Count(r.ModsByDir[x].Dir, "/")
+			return strings.Count(r.modsByDir[x].Dir, "/")
 		}
 		return count(j) < count(i) // descending order
 	})
 
+	r.roots = []gopathwalk.Root{
+		{filepath.Join(r.env.GOROOT, "/src"), gopathwalk.RootGOROOT},
+	}
+	if r.main != nil {
+		r.roots = append(r.roots, gopathwalk.Root{r.main.Dir, gopathwalk.RootCurrentModule})
+	}
+	if vendorEnabled {
+		r.roots = append(r.roots, gopathwalk.Root{r.dummyVendorMod.Dir, gopathwalk.RootOther})
+	} else {
+		addDep := func(mod *ModuleJSON) {
+			if mod.Replace == nil {
+				// This is redundant with the cache, but we'll skip it cheaply enough.
+				r.roots = append(r.roots, gopathwalk.Root{mod.Dir, gopathwalk.RootModuleCache})
+			} else {
+				r.roots = append(r.roots, gopathwalk.Root{mod.Dir, gopathwalk.RootOther})
+			}
+		}
+		// Walk dependent modules before scanning the full mod cache, direct deps first.
+		for _, mod := range r.modsByModPath {
+			if !mod.Indirect && !mod.Main {
+				addDep(mod)
+			}
+		}
+		for _, mod := range r.modsByModPath {
+			if mod.Indirect && !mod.Main {
+				addDep(mod)
+			}
+		}
+		r.roots = append(r.roots, gopathwalk.Root{r.moduleCacheDir, gopathwalk.RootModuleCache})
+	}
+
+	r.scannedRoots = map[gopathwalk.Root]bool{}
 	if r.moduleCacheCache == nil {
 		r.moduleCacheCache = &dirInfoCache{
 			dirs:      map[string]*directoryPackageInfo{},
+			listeners: map[*int]cacheListener{},
 		}
 	}
 	if r.otherCache == nil {
 		r.otherCache = &dirInfoCache{
 			dirs:      map[string]*directoryPackageInfo{},
+			listeners: map[*int]cacheListener{},
 		}
 	}
-	r.Initialized = true
+	r.initialized = true
 	return nil
 }
 
@@ -116,27 +162,35 @@ func (r *ModuleResolver) initAllMods() error {
 			// Can't do anything with a module that's not downloaded.
 			continue
 		}
-		r.ModsByModPath = append(r.ModsByModPath, mod)
+		r.modsByModPath = append(r.modsByModPath, mod)
-		r.ModsByDir = append(r.ModsByDir, mod)
+		r.modsByDir = append(r.modsByDir, mod)
 		if mod.Main {
-			r.Main = mod
+			r.main = mod
 		}
 	}
 	return nil
 }
 
 func (r *ModuleResolver) ClearForNewScan() {
+	<-r.scanSema
+	r.scannedRoots = map[gopathwalk.Root]bool{}
 	r.otherCache = &dirInfoCache{
 		dirs:      map[string]*directoryPackageInfo{},
+		listeners: map[*int]cacheListener{},
 	}
+	r.scanSema <- struct{}{}
 }
 
 func (r *ModuleResolver) ClearForNewMod() {
-	env := r.env
+	<-r.scanSema
 	*r = ModuleResolver{
-		env: env,
+		env:              r.env,
+		moduleCacheCache: r.moduleCacheCache,
+		otherCache:       r.otherCache,
+		scanSema:         r.scanSema,
 	}
 	r.init()
+	r.scanSema <- struct{}{}
 }
 
 // findPackage returns the module and directory that contains the package at
@@ -144,7 +198,7 @@ func (r *ModuleResolver) ClearForNewMod() {
 func (r *ModuleResolver) findPackage(importPath string) (*ModuleJSON, string) {
 	// This can't find packages in the stdlib, but that's harmless for all
 	// the existing code paths.
-	for _, m := range r.ModsByModPath {
+	for _, m := range r.modsByModPath {
 		if !strings.HasPrefix(importPath, m.Path) {
 			continue
 		}
@@ -211,7 +265,7 @@ func (r *ModuleResolver) cacheKeys() []string {
 }
 
 // cachePackageName caches the package name for a dir already in the cache.
-func (r *ModuleResolver) cachePackageName(info directoryPackageInfo) (directoryPackageInfo, error) {
+func (r *ModuleResolver) cachePackageName(info directoryPackageInfo) (string, error) {
 	if info.rootType == gopathwalk.RootModuleCache {
 		return r.moduleCacheCache.CachePackageName(info)
 	}
@@ -238,7 +292,7 @@ func (r *ModuleResolver) findModuleByDir(dir string) *ModuleJSON {
 	// - 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 {
+	for _, m := range r.modsByDir {
 		if !strings.HasPrefix(dir, m.Dir) {
 			continue
 		}
@@ -333,41 +387,49 @@ func (r *ModuleResolver) loadPackageNames(importPaths []string, srcDir string) (
 	return names, nil
 }
 
-func (r *ModuleResolver) scan(_ references, loadNames bool, exclude []gopathwalk.RootType) ([]*pkg, error) {
+func (r *ModuleResolver) scan(ctx context.Context, callback *scanCallback) error {
 	if err := r.init(); err != nil {
-		return nil, err
+		return err
 	}
 
-	// Walk GOROOT, GOPATH/pkg/mod, and the main module.
+	processDir := func(info directoryPackageInfo) {
-	roots := []gopathwalk.Root{
+		// Skip this directory if we were not able to get the package information successfully.
-		{filepath.Join(r.env.GOROOT, "/src"), gopathwalk.RootGOROOT},
+		if scanned, err := info.reachedStatus(directoryScanned); !scanned || err != nil {
-	}
+			return
-	if r.Main != nil {
-		roots = append(roots, gopathwalk.Root{r.Main.Dir, gopathwalk.RootCurrentModule})
-	}
-	if r.dummyVendorMod != nil {
-		roots = append(roots, gopathwalk.Root{r.dummyVendorMod.Dir, gopathwalk.RootOther})
-	} else {
-		roots = append(roots, gopathwalk.Root{r.moduleCacheDir, gopathwalk.RootModuleCache})
-		// Walk replace targets, just in case they're not in any of the above.
-		for _, mod := range r.ModsByModPath {
-			if mod.Replace != nil {
-				roots = append(roots, gopathwalk.Root{mod.Dir, gopathwalk.RootOther})
-			}
 		}
+		pkg, err := r.canonicalize(info)
+		if err != nil {
+			return
 		}
 
-	roots = filterRoots(roots, exclude)
+		if !callback.dirFound(pkg) {
+			return
+		}
+		pkg.packageName, err = r.cachePackageName(info)
+		if err != nil {
+			return
+		}
 
-	var result []*pkg
+		if !callback.packageNameLoaded(pkg) {
-	var mu sync.Mutex
+			return
+		}
+		_, exports, err := r.loadExports(ctx, pkg, false)
+		if err != nil {
+			return
+		}
+		callback.exportsLoaded(pkg, exports)
+	}
 
-	// We assume cached directories have not changed. We can skip them and their
+	// Start processing everything in the cache, and listen for the new stuff
-	// children.
+	// we discover in the walk below.
+	stop1 := r.moduleCacheCache.ScanAndListen(ctx, processDir)
+	defer stop1()
+	stop2 := r.otherCache.ScanAndListen(ctx, processDir)
+	defer stop2()
+
+	// We assume cached directories are fully cached, including all their
+	// children, and have not changed. We can skip them.
 	skip := func(root gopathwalk.Root, dir string) bool {
-		mu.Lock()
-		defer mu.Unlock()
-
 		info, ok := r.cacheLoad(dir)
 		if !ok {
 			return false
@@ -379,44 +441,64 @@ func (r *ModuleResolver) scan(_ references, loadNames bool, exclude []gopathwalk
 		return packageScanned
 	}
 
-	// Add anything new to the cache. We'll process everything in it below.
+	// Add anything new to the cache, and process it if we're still listening.
 	add := func(root gopathwalk.Root, dir string) {
-		mu.Lock()
-		defer mu.Unlock()
-
 		r.cacheStore(r.scanDirForPackage(root, dir))
 	}
 
-	gopathwalk.WalkSkip(roots, add, skip, gopathwalk.Options{Debug: r.env.Debug, ModulesEnabled: true})
+	// r.roots and the callback are not necessarily safe to use in the
+	// goroutine below. Process them eagerly.
+	roots := filterRoots(r.roots, callback.rootFound)
+	// We can't cancel walks, because we need them to finish to have a usable
+	// cache. Instead, run them in a separate goroutine and detach.
+	scanDone := make(chan struct{})
+	go func() {
+		select {
+		case <-ctx.Done():
+			return
+		case <-r.scanSema:
+		}
+		defer func() { r.scanSema <- struct{}{} }()
+		// We have the lock on r.scannedRoots, and no other scans can run.
+		for _, root := range roots {
+			if ctx.Err() != nil {
+				return
+			}
 
-	// Everything we already had, and everything new, is now in the cache.
+			if r.scannedRoots[root] {
-	for _, dir := range r.cacheKeys() {
-		info, ok := r.cacheLoad(dir)
-		if !ok {
 				continue
 			}
+			gopathwalk.WalkSkip([]gopathwalk.Root{root}, add, skip, gopathwalk.Options{Debug: r.env.Debug, ModulesEnabled: true})
+			r.scannedRoots[root] = true
+		}
+		close(scanDone)
+	}()
+	select {
+	case <-ctx.Done():
+	case <-scanDone:
+	}
+	return nil
+}
 
-		// Skip this directory if we were not able to get the package information successfully.
+func (r *ModuleResolver) scoreImportPath(ctx context.Context, path string) int {
-		if scanned, err := info.reachedStatus(directoryScanned); !scanned || err != nil {
+	if _, ok := stdlib[path]; ok {
-			continue
+		return MaxRelevance
 	}
+	mod, _ := r.findPackage(path)
+	return modRelevance(mod)
+}
 
-		// If we want package names, make sure the cache has them.
+func modRelevance(mod *ModuleJSON) int {
-		if loadNames {
+	switch {
-			var err error
+	case mod == nil: // out of scope
-			if info, err = r.cachePackageName(info); err != nil {
+		return MaxRelevance - 4
-				continue
+	case mod.Indirect:
+		return MaxRelevance - 3
+	case !mod.Main:
+		return MaxRelevance - 2
+	default:
+		return MaxRelevance - 1 // main module ties with stdlib
 	}
-		}
-
-		res, err := r.canonicalize(info)
-		if err != nil {
-			continue
-		}
-		result = append(result, res)
-	}
-
-	return result, nil
 }
 
 // canonicalize gets the result of canonicalizing the packages using the results
@@ -428,15 +510,14 @@ func (r *ModuleResolver) canonicalize(info directoryPackageInfo) (*pkg, error) {
 			importPathShort: info.nonCanonicalImportPath,
 			dir:             info.dir,
 			packageName:     path.Base(info.nonCanonicalImportPath),
-			relevance:       0,
+			relevance:       MaxRelevance,
 		}, nil
 	}
 
 	importPath := info.nonCanonicalImportPath
-	relevance := 2
+	mod := r.findModuleByDir(info.dir)
 	// Check if the directory is underneath a module that's in scope.
-	if mod := r.findModuleByDir(info.dir); mod != nil {
+	if mod != nil {
-		relevance = 1
 		// It is. If dir is the target of a replace directive,
 		// our guessed import path is wrong. Use the real one.
 		if mod.Dir == info.dir {
@@ -445,15 +526,16 @@ func (r *ModuleResolver) canonicalize(info directoryPackageInfo) (*pkg, error) {
 			dirInMod := info.dir[len(mod.Dir)+len("/"):]
 			importPath = path.Join(mod.Path, filepath.ToSlash(dirInMod))
 		}
-	} else if info.needsReplace {
+	} else if !strings.HasPrefix(importPath, info.moduleName) {
+		// The module's name doesn't match the package's import path. It
+		// probably needs a replace directive we don't have.
 		return nil, fmt.Errorf("package in %q is not valid without a replace statement", info.dir)
 	}
 
 	res := &pkg{
 		importPathShort: importPath,
 		dir:             info.dir,
-		packageName:     info.packageName, // may not be populated if the caller didn't ask for it
+		relevance:       modRelevance(mod),
-		relevance:       relevance,
 	}
 	// We may have discovered a package that has a different version
 	// in scope already. Canonicalize to that one if possible.
@@ -463,14 +545,14 @@ func (r *ModuleResolver) canonicalize(info directoryPackageInfo) (*pkg, error) {
 	return res, nil
 }
 
-func (r *ModuleResolver) loadExports(ctx context.Context, pkg *pkg) (string, []string, error) {
+func (r *ModuleResolver) loadExports(ctx context.Context, pkg *pkg, includeTest bool) (string, []string, error) {
 	if err := r.init(); err != nil {
 		return "", nil, err
 	}
-	if info, ok := r.cacheLoad(pkg.dir); ok {
+	if info, ok := r.cacheLoad(pkg.dir); ok && !includeTest {
 		return r.cacheExports(ctx, r.env, info)
 	}
-	return loadExportsFromFiles(ctx, r.env, pkg.dir)
+	return loadExportsFromFiles(ctx, r.env, pkg.dir, includeTest)
 }
 
 func (r *ModuleResolver) scanDirForPackage(root gopathwalk.Root, dir string) directoryPackageInfo {
@@ -488,7 +570,7 @@ func (r *ModuleResolver) scanDirForPackage(root gopathwalk.Root, dir string) dir
 	}
 	switch root.Type {
 	case gopathwalk.RootCurrentModule:
-		importPath = path.Join(r.Main.Path, filepath.ToSlash(subdir))
+		importPath = path.Join(r.main.Path, filepath.ToSlash(subdir))
 	case gopathwalk.RootModuleCache:
 		matches := modCacheRegexp.FindStringSubmatch(subdir)
 		if len(matches) == 0 {
@@ -516,7 +598,6 @@ func (r *ModuleResolver) scanDirForPackage(root gopathwalk.Root, dir string) dir
 		dir:                    dir,
 		rootType:               root.Type,
 		nonCanonicalImportPath: importPath,
-		needsReplace:           false,
 		moduleDir:              modDir,
 		moduleName:             modName,
 	}
@@ -524,14 +605,6 @@ func (r *ModuleResolver) scanDirForPackage(root gopathwalk.Root, dir string) dir
 		// stdlib packages are always in scope, despite the confusing go.mod
 		return result
 	}
-	// Check that this package is not obviously impossible to import.
-	if !strings.HasPrefix(importPath, modName) {
-		// The module's declared path does not match
-		// its expected path. It probably needs a
-		// replace directive we don't have.
-		result.needsReplace = true
-	}
-
 	return result
 }
 

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

@@ -49,10 +49,6 @@ type directoryPackageInfo struct {
 	// nonCanonicalImportPath is the package's expected import path. It may
 	// not actually be importable at that path.
 	nonCanonicalImportPath string
-	// needsReplace is true if the nonCanonicalImportPath does not match the
-	// module's declared path, making it impossible to import without a
-	// replace directive.
-	needsReplace bool
 
 	// Module-related information.
 	moduleDir  string // The directory that is the module root of this dir.
@@ -98,14 +94,84 @@ type dirInfoCache struct {
 	mu sync.Mutex
 	// dirs stores information about packages in directories, keyed by absolute path.
 	dirs      map[string]*directoryPackageInfo
+	listeners map[*int]cacheListener
+}
+
+type cacheListener func(directoryPackageInfo)
+
+// ScanAndListen calls listener on all the items in the cache, and on anything
+// newly added. The returned stop function waits for all in-flight callbacks to
+// finish and blocks new ones.
+func (d *dirInfoCache) ScanAndListen(ctx context.Context, listener cacheListener) func() {
+	ctx, cancel := context.WithCancel(ctx)
+
+	// Flushing out all the callbacks is tricky without knowing how many there
+	// are going to be. Setting an arbitrary limit makes it much easier.
+	const maxInFlight = 10
+	sema := make(chan struct{}, maxInFlight)
+	for i := 0; i < maxInFlight; i++ {
+		sema <- struct{}{}
+	}
+
+	cookie := new(int) // A unique ID we can use for the listener.
+
+	// We can't hold mu while calling the listener.
+	d.mu.Lock()
+	var keys []string
+	for key := range d.dirs {
+		keys = append(keys, key)
+	}
+	d.listeners[cookie] = func(info directoryPackageInfo) {
+		select {
+		case <-ctx.Done():
+			return
+		case <-sema:
+		}
+		listener(info)
+		sema <- struct{}{}
+	}
+	d.mu.Unlock()
+
+	// Process the pre-existing keys.
+	for _, k := range keys {
+		select {
+		case <-ctx.Done():
+			cancel()
+			return func() {}
+		default:
+		}
+		if v, ok := d.Load(k); ok {
+			listener(v)
+		}
+	}
+
+	return func() {
+		cancel()
+		d.mu.Lock()
+		delete(d.listeners, cookie)
+		d.mu.Unlock()
+		for i := 0; i < maxInFlight; i++ {
+			<-sema
+		}
+	}
 }
 
 // Store stores the package info for dir.
 func (d *dirInfoCache) Store(dir string, info directoryPackageInfo) {
 	d.mu.Lock()
-	defer d.mu.Unlock()
+	_, old := d.dirs[dir]
-	stored := info // defensive copy
+	d.dirs[dir] = &info
-	d.dirs[dir] = &stored
+	var listeners []cacheListener
+	for _, l := range d.listeners {
+		listeners = append(listeners, l)
+	}
+	d.mu.Unlock()
+
+	if !old {
+		for _, l := range listeners {
+			l(info)
+		}
+	}
 }
 
 // Load returns a copy of the directoryPackageInfo for absolute directory dir.
@@ -129,17 +195,17 @@ func (d *dirInfoCache) Keys() (keys []string) {
 	return keys
 }
 
-func (d *dirInfoCache) CachePackageName(info directoryPackageInfo) (directoryPackageInfo, error) {
+func (d *dirInfoCache) CachePackageName(info directoryPackageInfo) (string, error) {
 	if loaded, err := info.reachedStatus(nameLoaded); loaded {
-		return info, err
+		return info.packageName, err
 	}
 	if scanned, err := info.reachedStatus(directoryScanned); !scanned || err != nil {
-		return info, fmt.Errorf("cannot read package name, scan error: %v", err)
+		return "", fmt.Errorf("cannot read package name, scan error: %v", err)
 	}
 	info.packageName, info.err = packageDirToName(info.dir)
 	info.status = nameLoaded
 	d.Store(info.dir, info)
-	return info, info.err
+	return info.packageName, info.err
 }
 
 func (d *dirInfoCache) CacheExports(ctx context.Context, env *ProcessEnv, info directoryPackageInfo) (string, []string, error) {
@@ -149,8 +215,8 @@ func (d *dirInfoCache) CacheExports(ctx context.Context, env *ProcessEnv, info d
 	if reached, err := info.reachedStatus(nameLoaded); reached && err != nil {
 		return "", nil, err
 	}
-	info.packageName, info.exports, info.err = loadExportsFromFiles(ctx, env, info.dir)
+	info.packageName, info.exports, info.err = loadExportsFromFiles(ctx, env, info.dir, false)
-	if info.err == context.Canceled {
+	if info.err == context.Canceled || info.err == context.DeadlineExceeded {
 		return info.packageName, info.exports, info.err
 	}
 	// The cache structure wants things to proceed linearly. We can skip a

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

@@ -0,0 +1,4 @@
+// Package packagesinternal exposes internal-only fields from go/packages.
+package packagesinternal
+
+var GetForTest = func(p interface{}) string { return "" }

vendor/golang.org/x/tools/internal/span/parse.go

@@ -1,100 +0,0 @@
-// 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.
-
-package span
-
-import (
-	"strconv"
-	"strings"
-	"unicode/utf8"
-)
-
-// Parse returns the location represented by the input.
-// All inputs are valid locations, as they can always be a pure filename.
-// The returned span will be normalized, and thus if printed may produce a
-// different string.
-func Parse(input string) Span {
-	// :0:0#0-0:0#0
-	valid := input
-	var hold, offset int
-	hadCol := false
-	suf := rstripSuffix(input)
-	if suf.sep == "#" {
-		offset = suf.num
-		suf = rstripSuffix(suf.remains)
-	}
-	if suf.sep == ":" {
-		valid = suf.remains
-		hold = suf.num
-		hadCol = true
-		suf = rstripSuffix(suf.remains)
-	}
-	switch {
-	case suf.sep == ":":
-		return New(NewURI(suf.remains), NewPoint(suf.num, hold, offset), Point{})
-	case suf.sep == "-":
-		// we have a span, fall out of the case to continue
-	default:
-		// separator not valid, rewind to either the : or the start
-		return New(NewURI(valid), NewPoint(hold, 0, offset), Point{})
-	}
-	// only the span form can get here
-	// at this point we still don't know what the numbers we have mean
-	// if have not yet seen a : then we might have either a line or a column depending
-	// on whether start has a column or not
-	// we build an end point and will fix it later if needed
-	end := NewPoint(suf.num, hold, offset)
-	hold, offset = 0, 0
-	suf = rstripSuffix(suf.remains)
-	if suf.sep == "#" {
-		offset = suf.num
-		suf = rstripSuffix(suf.remains)
-	}
-	if suf.sep != ":" {
-		// turns out we don't have a span after all, rewind
-		return New(NewURI(valid), end, Point{})
-	}
-	valid = suf.remains
-	hold = suf.num
-	suf = rstripSuffix(suf.remains)
-	if suf.sep != ":" {
-		// line#offset only
-		return New(NewURI(valid), NewPoint(hold, 0, offset), end)
-	}
-	// we have a column, so if end only had one number, it is also the column
-	if !hadCol {
-		end = NewPoint(suf.num, end.v.Line, end.v.Offset)
-	}
-	return New(NewURI(suf.remains), NewPoint(suf.num, hold, offset), end)
-}
-
-type suffix struct {
-	remains string
-	sep     string
-	num     int
-}
-
-func rstripSuffix(input string) suffix {
-	if len(input) == 0 {
-		return suffix{"", "", -1}
-	}
-	remains := input
-	num := -1
-	// first see if we have a number at the end
-	last := strings.LastIndexFunc(remains, func(r rune) bool { return r < '0' || r > '9' })
-	if last >= 0 && last < len(remains)-1 {
-		number, err := strconv.ParseInt(remains[last+1:], 10, 64)
-		if err == nil {
-			num = int(number)
-			remains = remains[:last+1]
-		}
-	}
-	// now see if we have a trailing separator
-	r, w := utf8.DecodeLastRuneInString(remains)
-	if r != ':' && r != '#' && r == '#' {
-		return suffix{input, "", -1}
-	}
-	remains = remains[:len(remains)-w]
-	return suffix{remains, string(r), num}
-}

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

@@ -1,285 +0,0 @@
-// 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.
-
-// Package span contains support for representing with positions and ranges in
-// text files.
-package span
-
-import (
-	"encoding/json"
-	"fmt"
-	"path"
-)
-
-// Span represents a source code range in standardized form.
-type Span struct {
-	v span
-}
-
-// Point represents a single point within a file.
-// In general this should only be used as part of a Span, as on its own it
-// does not carry enough information.
-type Point struct {
-	v point
-}
-
-type span struct {
-	URI   URI   `json:"uri"`
-	Start point `json:"start"`
-	End   point `json:"end"`
-}
-
-type point struct {
-	Line   int `json:"line"`
-	Column int `json:"column"`
-	Offset int `json:"offset"`
-}
-
-// Invalid is a span that reports false from IsValid
-var Invalid = Span{v: span{Start: invalidPoint.v, End: invalidPoint.v}}
-
-var invalidPoint = Point{v: point{Line: 0, Column: 0, Offset: -1}}
-
-// Converter is the interface to an object that can convert between line:column
-// and offset forms for a single file.
-type Converter interface {
-	//ToPosition converts from an offset to a line:column pair.
-	ToPosition(offset int) (int, int, error)
-	//ToOffset converts from a line:column pair to an offset.
-	ToOffset(line, col int) (int, error)
-}
-
-func New(uri URI, start Point, end Point) Span {
-	s := Span{v: span{URI: uri, Start: start.v, End: end.v}}
-	s.v.clean()
-	return s
-}
-
-func NewPoint(line, col, offset int) Point {
-	p := Point{v: point{Line: line, Column: col, Offset: offset}}
-	p.v.clean()
-	return p
-}
-
-func Compare(a, b Span) int {
-	if r := CompareURI(a.URI(), b.URI()); r != 0 {
-		return r
-	}
-	if r := comparePoint(a.v.Start, b.v.Start); r != 0 {
-		return r
-	}
-	return comparePoint(a.v.End, b.v.End)
-}
-
-func ComparePoint(a, b Point) int {
-	return comparePoint(a.v, b.v)
-}
-
-func comparePoint(a, b point) int {
-	if !a.hasPosition() {
-		if a.Offset < b.Offset {
-			return -1
-		}
-		if a.Offset > b.Offset {
-			return 1
-		}
-		return 0
-	}
-	if a.Line < b.Line {
-		return -1
-	}
-	if a.Line > b.Line {
-		return 1
-	}
-	if a.Column < b.Column {
-		return -1
-	}
-	if a.Column > b.Column {
-		return 1
-	}
-	return 0
-}
-
-func (s Span) HasPosition() bool             { return s.v.Start.hasPosition() }
-func (s Span) HasOffset() bool               { return s.v.Start.hasOffset() }
-func (s Span) IsValid() bool                 { return s.v.Start.isValid() }
-func (s Span) IsPoint() bool                 { return s.v.Start == s.v.End }
-func (s Span) URI() URI                      { return s.v.URI }
-func (s Span) Start() Point                  { return Point{s.v.Start} }
-func (s Span) End() Point                    { return Point{s.v.End} }
-func (s *Span) MarshalJSON() ([]byte, error) { return json.Marshal(&s.v) }
-func (s *Span) UnmarshalJSON(b []byte) error { return json.Unmarshal(b, &s.v) }
-
-func (p Point) HasPosition() bool             { return p.v.hasPosition() }
-func (p Point) HasOffset() bool               { return p.v.hasOffset() }
-func (p Point) IsValid() bool                 { return p.v.isValid() }
-func (p *Point) MarshalJSON() ([]byte, error) { return json.Marshal(&p.v) }
-func (p *Point) UnmarshalJSON(b []byte) error { return json.Unmarshal(b, &p.v) }
-func (p Point) Line() int {
-	if !p.v.hasPosition() {
-		panic(fmt.Errorf("position not set in %v", p.v))
-	}
-	return p.v.Line
-}
-func (p Point) Column() int {
-	if !p.v.hasPosition() {
-		panic(fmt.Errorf("position not set in %v", p.v))
-	}
-	return p.v.Column
-}
-func (p Point) Offset() int {
-	if !p.v.hasOffset() {
-		panic(fmt.Errorf("offset not set in %v", p.v))
-	}
-	return p.v.Offset
-}
-
-func (p point) hasPosition() bool { return p.Line > 0 }
-func (p point) hasOffset() bool   { return p.Offset >= 0 }
-func (p point) isValid() bool     { return p.hasPosition() || p.hasOffset() }
-func (p point) isZero() bool {
-	return (p.Line == 1 && p.Column == 1) || (!p.hasPosition() && p.Offset == 0)
-}
-
-func (s *span) clean() {
-	//this presumes the points are already clean
-	if !s.End.isValid() || (s.End == point{}) {
-		s.End = s.Start
-	}
-}
-
-func (p *point) clean() {
-	if p.Line < 0 {
-		p.Line = 0
-	}
-	if p.Column <= 0 {
-		if p.Line > 0 {
-			p.Column = 1
-		} else {
-			p.Column = 0
-		}
-	}
-	if p.Offset == 0 && (p.Line > 1 || p.Column > 1) {
-		p.Offset = -1
-	}
-}
-
-// Format implements fmt.Formatter to print the Location in a standard form.
-// The format produced is one that can be read back in using Parse.
-func (s Span) Format(f fmt.State, c rune) {
-	fullForm := f.Flag('+')
-	preferOffset := f.Flag('#')
-	// we should always have a uri, simplify if it is file format
-	//TODO: make sure the end of the uri is unambiguous
-	uri := string(s.v.URI)
-	if c == 'f' {
-		uri = path.Base(uri)
-	} else if !fullForm {
-		uri = s.v.URI.Filename()
-	}
-	fmt.Fprint(f, uri)
-	if !s.IsValid() || (!fullForm && s.v.Start.isZero() && s.v.End.isZero()) {
-		return
-	}
-	// see which bits of start to write
-	printOffset := s.HasOffset() && (fullForm || preferOffset || !s.HasPosition())
-	printLine := s.HasPosition() && (fullForm || !printOffset)
-	printColumn := printLine && (fullForm || (s.v.Start.Column > 1 || s.v.End.Column > 1))
-	fmt.Fprint(f, ":")
-	if printLine {
-		fmt.Fprintf(f, "%d", s.v.Start.Line)
-	}
-	if printColumn {
-		fmt.Fprintf(f, ":%d", s.v.Start.Column)
-	}
-	if printOffset {
-		fmt.Fprintf(f, "#%d", s.v.Start.Offset)
-	}
-	// start is written, do we need end?
-	if s.IsPoint() {
-		return
-	}
-	// we don't print the line if it did not change
-	printLine = fullForm || (printLine && s.v.End.Line > s.v.Start.Line)
-	fmt.Fprint(f, "-")
-	if printLine {
-		fmt.Fprintf(f, "%d", s.v.End.Line)
-	}
-	if printColumn {
-		if printLine {
-			fmt.Fprint(f, ":")
-		}
-		fmt.Fprintf(f, "%d", s.v.End.Column)
-	}
-	if printOffset {
-		fmt.Fprintf(f, "#%d", s.v.End.Offset)
-	}
-}
-
-func (s Span) WithPosition(c Converter) (Span, error) {
-	if err := s.update(c, true, false); err != nil {
-		return Span{}, err
-	}
-	return s, nil
-}
-
-func (s Span) WithOffset(c Converter) (Span, error) {
-	if err := s.update(c, false, true); err != nil {
-		return Span{}, err
-	}
-	return s, nil
-}
-
-func (s Span) WithAll(c Converter) (Span, error) {
-	if err := s.update(c, true, true); err != nil {
-		return Span{}, err
-	}
-	return s, nil
-}
-
-func (s *Span) update(c Converter, withPos, withOffset bool) error {
-	if !s.IsValid() {
-		return fmt.Errorf("cannot add information to an invalid span")
-	}
-	if withPos && !s.HasPosition() {
-		if err := s.v.Start.updatePosition(c); err != nil {
-			return err
-		}
-		if s.v.End.Offset == s.v.Start.Offset {
-			s.v.End = s.v.Start
-		} else if err := s.v.End.updatePosition(c); err != nil {
-			return err
-		}
-	}
-	if withOffset && (!s.HasOffset() || (s.v.End.hasPosition() && !s.v.End.hasOffset())) {
-		if err := s.v.Start.updateOffset(c); err != nil {
-			return err
-		}
-		if s.v.End.Line == s.v.Start.Line && s.v.End.Column == s.v.Start.Column {
-			s.v.End.Offset = s.v.Start.Offset
-		} else if err := s.v.End.updateOffset(c); err != nil {
-			return err
-		}
-	}
-	return nil
-}
-
-func (p *point) updatePosition(c Converter) error {
-	line, col, err := c.ToPosition(p.Offset)
-	if err != nil {
-		return err
-	}
-	p.Line = line
-	p.Column = col
-	return nil
-}
-
-func (p *point) updateOffset(c Converter) error {
-	offset, err := c.ToOffset(p.Line, p.Column)
-	if err != nil {
-		return err
-	}
-	p.Offset = offset
-	return nil
-}

vendor/golang.org/x/tools/internal/span/token.go

@@ -1,179 +0,0 @@
-// 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.
-
-package span
-
-import (
-	"fmt"
-	"go/token"
-)
-
-// Range represents a source code range in token.Pos form.
-// It also carries the FileSet that produced the positions, so that it is
-// self contained.
-type Range struct {
-	FileSet   *token.FileSet
-	Start     token.Pos
-	End       token.Pos
-	Converter Converter
-}
-
-// TokenConverter is a Converter backed by a token file set and file.
-// It uses the file set methods to work out the conversions, which
-// makes it fast and does not require the file contents.
-type TokenConverter struct {
-	fset *token.FileSet
-	file *token.File
-}
-
-// NewRange creates a new Range from a FileSet and two positions.
-// To represent a point pass a 0 as the end pos.
-func NewRange(fset *token.FileSet, start, end token.Pos) Range {
-	return Range{
-		FileSet: fset,
-		Start:   start,
-		End:     end,
-	}
-}
-
-// NewTokenConverter returns an implementation of Converter backed by a
-// token.File.
-func NewTokenConverter(fset *token.FileSet, f *token.File) *TokenConverter {
-	return &TokenConverter{fset: fset, file: f}
-}
-
-// NewContentConverter returns an implementation of Converter for the
-// given file content.
-func NewContentConverter(filename string, content []byte) *TokenConverter {
-	fset := token.NewFileSet()
-	f := fset.AddFile(filename, -1, len(content))
-	f.SetLinesForContent(content)
-	return &TokenConverter{fset: fset, file: f}
-}
-
-// IsPoint returns true if the range represents a single point.
-func (r Range) IsPoint() bool {
-	return r.Start == r.End
-}
-
-// Span converts a Range to a Span that represents the Range.
-// It will fill in all the members of the Span, calculating the line and column
-// information.
-func (r Range) Span() (Span, error) {
-	f := r.FileSet.File(r.Start)
-	if f == nil {
-		return Span{}, fmt.Errorf("file not found in FileSet")
-	}
-	var s Span
-	var err error
-	var startFilename string
-	startFilename, s.v.Start.Line, s.v.Start.Column, err = position(f, r.Start)
-	if err != nil {
-		return Span{}, err
-	}
-	s.v.URI = FileURI(startFilename)
-	if r.End.IsValid() {
-		var endFilename string
-		endFilename, s.v.End.Line, s.v.End.Column, err = position(f, r.End)
-		if err != nil {
-			return Span{}, err
-		}
-		// In the presence of line directives, a single File can have sections from
-		// multiple file names.
-		if endFilename != startFilename {
-			return Span{}, fmt.Errorf("span begins in file %q but ends in %q", startFilename, endFilename)
-		}
-	}
-	s.v.Start.clean()
-	s.v.End.clean()
-	s.v.clean()
-	if r.Converter != nil {
-		return s.WithOffset(r.Converter)
-	}
-	if startFilename != f.Name() {
-		return Span{}, fmt.Errorf("must supply Converter for file %q containing lines from %q", f.Name(), startFilename)
-	}
-	return s.WithOffset(NewTokenConverter(r.FileSet, f))
-}
-
-func position(f *token.File, pos token.Pos) (string, int, int, error) {
-	off, err := offset(f, pos)
-	if err != nil {
-		return "", 0, 0, err
-	}
-	return positionFromOffset(f, off)
-}
-
-func positionFromOffset(f *token.File, offset int) (string, int, int, error) {
-	if offset > f.Size() {
-		return "", 0, 0, fmt.Errorf("offset %v is past the end of the file %v", offset, f.Size())
-	}
-	pos := f.Pos(offset)
-	p := f.Position(pos)
-	if offset == f.Size() {
-		return p.Filename, p.Line + 1, 1, nil
-	}
-	return p.Filename, p.Line, p.Column, nil
-}
-
-// offset is a copy of the Offset function in go/token, but with the adjustment
-// that it does not panic on invalid positions.
-func offset(f *token.File, pos token.Pos) (int, error) {
-	if int(pos) < f.Base() || int(pos) > f.Base()+f.Size() {
-		return 0, fmt.Errorf("invalid pos")
-	}
-	return int(pos) - f.Base(), nil
-}
-
-// Range converts a Span to a Range that represents the Span for the supplied
-// File.
-func (s Span) Range(converter *TokenConverter) (Range, error) {
-	s, err := s.WithOffset(converter)
-	if err != nil {
-		return Range{}, err
-	}
-	// go/token will panic if the offset is larger than the file's size,
-	// so check here to avoid panicking.
-	if s.Start().Offset() > converter.file.Size() {
-		return Range{}, fmt.Errorf("start offset %v is past the end of the file %v", s.Start(), converter.file.Size())
-	}
-	if s.End().Offset() > converter.file.Size() {
-		return Range{}, fmt.Errorf("end offset %v is past the end of the file %v", s.End(), converter.file.Size())
-	}
-	return Range{
-		FileSet:   converter.fset,
-		Start:     converter.file.Pos(s.Start().Offset()),
-		End:       converter.file.Pos(s.End().Offset()),
-		Converter: converter,
-	}, nil
-}
-
-func (l *TokenConverter) ToPosition(offset int) (int, int, error) {
-	_, line, col, err := positionFromOffset(l.file, offset)
-	return line, col, err
-}
-
-func (l *TokenConverter) ToOffset(line, col int) (int, error) {
-	if line < 0 {
-		return -1, fmt.Errorf("line is not valid")
-	}
-	lineMax := l.file.LineCount() + 1
-	if line > lineMax {
-		return -1, fmt.Errorf("line is beyond end of file %v", lineMax)
-	} else if line == lineMax {
-		if col > 1 {
-			return -1, fmt.Errorf("column is beyond end of file")
-		}
-		// at the end of the file, allowing for a trailing eol
-		return l.file.Size(), nil
-	}
-	pos := lineStart(l.file, line)
-	if !pos.IsValid() {
-		return -1, fmt.Errorf("line is not in file")
-	}
-	// we assume that column is in bytes here, and that the first byte of a
-	// line is at column 1
-	pos += token.Pos(col - 1)
-	return offset(l.file, pos)
-}

vendor/golang.org/x/tools/internal/span/token111.go

@@ -1,39 +0,0 @@
-// 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.
-
-// +build !go1.12
-
-package span
-
-import (
-	"go/token"
-)
-
-// lineStart is the pre-Go 1.12 version of (*token.File).LineStart. For Go
-// versions <= 1.11, we borrow logic from the analysisutil package.
-// TODO(rstambler): Delete this file when we no longer support Go 1.11.
-func lineStart(f *token.File, line int) token.Pos {
-	// Use binary search to find the start offset of this line.
-
-	min := 0        // inclusive
-	max := f.Size() // exclusive
-	for {
-		offset := (min + max) / 2
-		pos := f.Pos(offset)
-		posn := f.Position(pos)
-		if posn.Line == line {
-			return pos - (token.Pos(posn.Column) - 1)
-		}
-
-		if min+1 >= max {
-			return token.NoPos
-		}
-
-		if posn.Line < line {
-			min = offset
-		} else {
-			max = offset
-		}
-	}
-}

vendor/golang.org/x/tools/internal/span/token112.go

@@ -1,16 +0,0 @@
-// 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.
-
-// +build go1.12
-
-package span
-
-import (
-	"go/token"
-)
-
-// TODO(rstambler): Delete this file when we no longer support Go 1.11.
-func lineStart(f *token.File, line int) token.Pos {
-	return f.LineStart(line)
-}

vendor/golang.org/x/tools/internal/span/uri.go

@@ -1,152 +0,0 @@
-// 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.
-
-package span
-
-import (
-	"fmt"
-	"net/url"
-	"os"
-	"path"
-	"path/filepath"
-	"runtime"
-	"strings"
-	"unicode"
-)
-
-const fileScheme = "file"
-
-// URI represents the full URI for a file.
-type URI string
-
-// Filename returns the file path for the given URI.
-// It is an error to call this on a URI that is not a valid filename.
-func (uri URI) Filename() string {
-	filename, err := filename(uri)
-	if err != nil {
-		panic(err)
-	}
-	return filepath.FromSlash(filename)
-}
-
-func filename(uri URI) (string, error) {
-	if uri == "" {
-		return "", nil
-	}
-	u, err := url.ParseRequestURI(string(uri))
-	if err != nil {
-		return "", err
-	}
-	if u.Scheme != fileScheme {
-		return "", fmt.Errorf("only file URIs are supported, got %q from %q", u.Scheme, uri)
-	}
-	if isWindowsDriveURI(u.Path) {
-		u.Path = u.Path[1:]
-	}
-	return u.Path, nil
-}
-
-// NewURI returns a span URI for the string.
-// It will attempt to detect if the string is a file path or uri.
-func NewURI(s string) URI {
-	if u, err := url.PathUnescape(s); err == nil {
-		s = u
-	}
-	if strings.HasPrefix(s, fileScheme+"://") {
-		return URI(s)
-	}
-	return FileURI(s)
-}
-
-func CompareURI(a, b URI) int {
-	if equalURI(a, b) {
-		return 0
-	}
-	if a < b {
-		return -1
-	}
-	return 1
-}
-
-func equalURI(a, b URI) bool {
-	if a == b {
-		return true
-	}
-	// If we have the same URI basename, we may still have the same file URIs.
-	if !strings.EqualFold(path.Base(string(a)), path.Base(string(b))) {
-		return false
-	}
-	fa, err := filename(a)
-	if err != nil {
-		return false
-	}
-	fb, err := filename(b)
-	if err != nil {
-		return false
-	}
-	// Stat the files to check if they are equal.
-	infoa, err := os.Stat(filepath.FromSlash(fa))
-	if err != nil {
-		return false
-	}
-	infob, err := os.Stat(filepath.FromSlash(fb))
-	if err != nil {
-		return false
-	}
-	return os.SameFile(infoa, infob)
-}
-
-// FileURI returns a span URI for the supplied file path.
-// It will always have the file scheme.
-func FileURI(path string) URI {
-	if path == "" {
-		return ""
-	}
-	// Handle standard library paths that contain the literal "$GOROOT".
-	// TODO(rstambler): The go/packages API should allow one to determine a user's $GOROOT.
-	const prefix = "$GOROOT"
-	if len(path) >= len(prefix) && strings.EqualFold(prefix, path[:len(prefix)]) {
-		suffix := path[len(prefix):]
-		path = runtime.GOROOT() + suffix
-	}
-	if !isWindowsDrivePath(path) {
-		if abs, err := filepath.Abs(path); err == nil {
-			path = abs
-		}
-	}
-	// Check the file path again, in case it became absolute.
-	if isWindowsDrivePath(path) {
-		path = "/" + path
-	}
-	path = filepath.ToSlash(path)
-	u := url.URL{
-		Scheme: fileScheme,
-		Path:   path,
-	}
-	uri := u.String()
-	if unescaped, err := url.PathUnescape(uri); err == nil {
-		uri = unescaped
-	}
-	return URI(uri)
-}
-
-// isWindowsDrivePath returns true if the file path is of the form used by
-// Windows. We check if the path begins with a drive letter, followed by a ":".
-func isWindowsDrivePath(path string) bool {
-	if len(path) < 4 {
-		return false
-	}
-	return unicode.IsLetter(rune(path[0])) && path[1] == ':'
-}
-
-// isWindowsDriveURI returns true if the file URI is of the format used by
-// Windows URIs. The url.Parse package does not specially handle Windows paths
-// (see https://golang.org/issue/6027). We check if the URI path has
-// a drive prefix (e.g. "/C:"). If so, we trim the leading "/".
-func isWindowsDriveURI(uri string) bool {
-	if len(uri) < 4 {
-		return false
-	}
-	return uri[0] == '/' && unicode.IsLetter(rune(uri[1])) && uri[2] == ':'
-}

vendor/golang.org/x/tools/internal/span/utf16.go

@@ -1,94 +0,0 @@
-// 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.
-
-package span
-
-import (
-	"fmt"
-	"unicode/utf16"
-	"unicode/utf8"
-)
-
-// ToUTF16Column calculates the utf16 column expressed by the point given the
-// supplied file contents.
-// This is used to convert from the native (always in bytes) column
-// representation and the utf16 counts used by some editors.
-func ToUTF16Column(p Point, content []byte) (int, error) {
-	if content == nil {
-		return -1, fmt.Errorf("ToUTF16Column: missing content")
-	}
-	if !p.HasPosition() {
-		return -1, fmt.Errorf("ToUTF16Column: point is missing position")
-	}
-	if !p.HasOffset() {
-		return -1, fmt.Errorf("ToUTF16Column: point is missing offset")
-	}
-	offset := p.Offset()      // 0-based
-	colZero := p.Column() - 1 // 0-based
-	if colZero == 0 {
-		// 0-based column 0, so it must be chr 1
-		return 1, nil
-	} else if colZero < 0 {
-		return -1, fmt.Errorf("ToUTF16Column: column is invalid (%v)", colZero)
-	}
-	// work out the offset at the start of the line using the column
-	lineOffset := offset - colZero
-	if lineOffset < 0 || offset > len(content) {
-		return -1, fmt.Errorf("ToUTF16Column: offsets %v-%v outside file contents (%v)", lineOffset, offset, len(content))
-	}
-	// Use the offset to pick out the line start.
-	// This cannot panic: offset > len(content) and lineOffset < offset.
-	start := content[lineOffset:]
-
-	// Now, truncate down to the supplied column.
-	start = start[:colZero]
-
-	// and count the number of utf16 characters
-	// in theory we could do this by hand more efficiently...
-	return len(utf16.Encode([]rune(string(start)))) + 1, nil
-}
-
-// FromUTF16Column advances the point by the utf16 character offset given the
-// supplied line contents.
-// This is used to convert from the utf16 counts used by some editors to the
-// native (always in bytes) column representation.
-func FromUTF16Column(p Point, chr int, content []byte) (Point, error) {
-	if !p.HasOffset() {
-		return Point{}, fmt.Errorf("FromUTF16Column: point is missing offset")
-	}
-	// if chr is 1 then no adjustment needed
-	if chr <= 1 {
-		return p, nil
-	}
-	if p.Offset() >= len(content) {
-		return p, fmt.Errorf("FromUTF16Column: offset (%v) greater than length of content (%v)", p.Offset(), len(content))
-	}
-	remains := content[p.Offset():]
-	// scan forward the specified number of characters
-	for count := 1; count < chr; count++ {
-		if len(remains) <= 0 {
-			return Point{}, fmt.Errorf("FromUTF16Column: chr goes beyond the content")
-		}
-		r, w := utf8.DecodeRune(remains)
-		if r == '\n' {
-			// Per the LSP spec:
-			//
-			// > If the character value is greater than the line length it
-			// > defaults back to the line length.
-			break
-		}
-		remains = remains[w:]
-		if r >= 0x10000 {
-			// a two point rune
-			count++
-			// if we finished in a two point rune, do not advance past the first
-			if count >= chr {
-				break
-			}
-		}
-		p.v.Column += w
-		p.v.Offset += w
-	}
-	return p, nil
-}

vendor/modules.txt

@@ -208,7 +208,7 @@ golang.org/x/crypto/acme
 golang.org/x/crypto/acme/autocert
 golang.org/x/crypto/bcrypt
 golang.org/x/crypto/blowfish
-# golang.org/x/lint v0.0.0-20190409202823-959b441ac422
+# golang.org/x/lint v0.0.0-20200302205851-738671d3881b
 golang.org/x/lint
 golang.org/x/lint/golint
 # golang.org/x/net v0.0.0-20200202094626-16171245cfb2
@@ -221,7 +221,7 @@ golang.org/x/text/transform
 golang.org/x/text/unicode/bidi
 golang.org/x/text/unicode/norm
 golang.org/x/text/width
-# golang.org/x/tools v0.0.0-20191130070609-6e064ea0cf2d
+# golang.org/x/tools v0.0.0-20200130002326-2f3ba24bd6e7
 golang.org/x/tools/go/ast/astutil
 golang.org/x/tools/go/ast/inspector
 golang.org/x/tools/go/buildutil
@@ -237,8 +237,8 @@ golang.org/x/tools/internal/fastwalk
 golang.org/x/tools/internal/gopathwalk
 golang.org/x/tools/internal/imports
 golang.org/x/tools/internal/module
+golang.org/x/tools/internal/packagesinternal
 golang.org/x/tools/internal/semver
-golang.org/x/tools/internal/span
 # gopkg.in/alexcesaro/quotedprintable.v3 v3.0.0-20150716171945-2caba252f4dc
 gopkg.in/alexcesaro/quotedprintable.v3
 # gopkg.in/d4l3k/messagediff.v1 v1.2.1