blob: e94ad7ba09c7bb5a93cd6768ab4613a7253d16f8 [file] [log] [blame]
// 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 cache
import (
"bytes"
"context"
"errors"
"fmt"
"go/ast"
"go/token"
"go/types"
"io"
"io/ioutil"
"os"
"path/filepath"
"regexp"
"runtime"
"sort"
"strconv"
"strings"
"sync"
"golang.org/x/mod/modfile"
"golang.org/x/mod/module"
"golang.org/x/mod/semver"
"golang.org/x/sync/errgroup"
"golang.org/x/tools/go/analysis"
"golang.org/x/tools/go/packages"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/gocommand"
"golang.org/x/tools/internal/lsp/bug"
"golang.org/x/tools/internal/lsp/debug/tag"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/memoize"
"golang.org/x/tools/internal/packagesinternal"
"golang.org/x/tools/internal/span"
"golang.org/x/tools/internal/typesinternal"
)
type snapshot struct {
memoize.Arg // allow as a memoize.Function arg
id uint64
view *View
cancel func()
backgroundCtx context.Context
// the cache generation that contains the data for this snapshot.
generation *memoize.Generation
// The snapshot's initialization state is controlled by the fields below.
//
// initializeOnce guards snapshot initialization. Each snapshot is
// initialized at most once: reinitialization is triggered on later snapshots
// by invalidating this field.
initializeOnce *sync.Once
// initializedErr holds the last error resulting from initialization. If
// initialization fails, we only retry when the the workspace modules change,
// to avoid too many go/packages calls.
initializedErr *source.CriticalError
// mu guards all of the maps in the snapshot, as well as the builtin URI.
mu sync.Mutex
// builtin pins the AST and package for builtin.go in memory.
builtin span.URI
// meta holds loaded metadata.
//
// meta is guarded by mu, but the metadataGraph itself is immutable.
// TODO(rfindley): in many places we hold mu while operating on meta, even
// though we only need to hold mu while reading the pointer.
meta *metadataGraph
// files maps file URIs to their corresponding FileHandles.
// It may invalidated when a file's content changes.
files filesMap
// goFiles maps a parseKey to its parseGoHandle.
goFiles goFilesMap
parseKeysByURI parseKeysByURIMap
// TODO(rfindley): consider merging this with files to reduce burden on clone.
symbols map[span.URI]*symbolHandle
// packages maps a packageKey to a set of packageHandles to which that file belongs.
// It may be invalidated when a file's content changes.
packages map[packageKey]*packageHandle
// actions maps an actionkey to its actionHandle.
actions map[actionKey]*actionHandle
// workspacePackages contains the workspace's packages, which are loaded
// when the view is created.
workspacePackages map[PackageID]PackagePath
// unloadableFiles keeps track of files that we've failed to load.
unloadableFiles map[span.URI]struct{}
// parseModHandles keeps track of any parseModHandles for the snapshot.
// The handles need not refer to only the view's go.mod file.
parseModHandles map[span.URI]*parseModHandle
// parseWorkHandles keeps track of any parseWorkHandles for the snapshot.
// The handles need not refer to only the view's go.work file.
parseWorkHandles map[span.URI]*parseWorkHandle
// Preserve go.mod-related handles to avoid garbage-collecting the results
// of various calls to the go command. The handles need not refer to only
// the view's go.mod file.
modTidyHandles map[span.URI]*modTidyHandle
modWhyHandles map[span.URI]*modWhyHandle
workspace *workspace
workspaceDirHandle *memoize.Handle
// knownSubdirs is the set of subdirectories in the workspace, used to
// create glob patterns for file watching.
knownSubdirs map[span.URI]struct{}
knownSubdirsPatternCache string
// unprocessedSubdirChanges are any changes that might affect the set of
// subdirectories in the workspace. They are not reflected to knownSubdirs
// during the snapshot cloning step as it can slow down cloning.
unprocessedSubdirChanges []*fileChange
}
type packageKey struct {
mode source.ParseMode
id PackageID
}
type actionKey struct {
pkg packageKey
analyzer *analysis.Analyzer
}
func (s *snapshot) Destroy(destroyedBy string) {
s.generation.Destroy(destroyedBy)
s.files.Destroy()
s.goFiles.Destroy()
s.parseKeysByURI.Destroy()
}
func (s *snapshot) ID() uint64 {
return s.id
}
func (s *snapshot) View() source.View {
return s.view
}
func (s *snapshot) BackgroundContext() context.Context {
return s.backgroundCtx
}
func (s *snapshot) FileSet() *token.FileSet {
return s.view.session.cache.fset
}
func (s *snapshot) ModFiles() []span.URI {
var uris []span.URI
for modURI := range s.workspace.getActiveModFiles() {
uris = append(uris, modURI)
}
return uris
}
func (s *snapshot) WorkFile() span.URI {
return s.workspace.workFile
}
func (s *snapshot) Templates() map[span.URI]source.VersionedFileHandle {
s.mu.Lock()
defer s.mu.Unlock()
tmpls := map[span.URI]source.VersionedFileHandle{}
s.files.Range(func(k span.URI, fh source.VersionedFileHandle) {
if s.view.FileKind(fh) == source.Tmpl {
tmpls[k] = fh
}
})
return tmpls
}
func (s *snapshot) ValidBuildConfiguration() bool {
return validBuildConfiguration(s.view.rootURI, &s.view.workspaceInformation, s.workspace.getActiveModFiles())
}
// workspaceMode describes the way in which the snapshot's workspace should
// be loaded.
func (s *snapshot) workspaceMode() workspaceMode {
var mode workspaceMode
// If the view has an invalid configuration, don't build the workspace
// module.
validBuildConfiguration := s.ValidBuildConfiguration()
if !validBuildConfiguration {
return mode
}
// If the view is not in a module and contains no modules, but still has a
// valid workspace configuration, do not create the workspace module.
// It could be using GOPATH or a different build system entirely.
if len(s.workspace.getActiveModFiles()) == 0 && validBuildConfiguration {
return mode
}
mode |= moduleMode
options := s.view.Options()
// The -modfile flag is available for Go versions >= 1.14.
if options.TempModfile && s.view.workspaceInformation.goversion >= 14 {
mode |= tempModfile
}
return mode
}
// config returns the configuration used for the snapshot's interaction with
// the go/packages API. It uses the given working directory.
//
// TODO(rstambler): go/packages requires that we do not provide overlays for
// multiple modules in on config, so buildOverlay needs to filter overlays by
// module.
func (s *snapshot) config(ctx context.Context, inv *gocommand.Invocation) *packages.Config {
s.view.optionsMu.Lock()
verboseOutput := s.view.options.VerboseOutput
s.view.optionsMu.Unlock()
cfg := &packages.Config{
Context: ctx,
Dir: inv.WorkingDir,
Env: inv.Env,
BuildFlags: inv.BuildFlags,
Mode: packages.NeedName |
packages.NeedFiles |
packages.NeedCompiledGoFiles |
packages.NeedImports |
packages.NeedDeps |
packages.NeedTypesSizes |
packages.NeedModule |
packages.LoadMode(packagesinternal.DepsErrors) |
packages.LoadMode(packagesinternal.ForTest),
Fset: s.FileSet(),
Overlay: s.buildOverlay(),
ParseFile: func(*token.FileSet, string, []byte) (*ast.File, error) {
panic("go/packages must not be used to parse files")
},
Logf: func(format string, args ...interface{}) {
if verboseOutput {
event.Log(ctx, fmt.Sprintf(format, args...))
}
},
Tests: true,
}
packagesinternal.SetModFile(cfg, inv.ModFile)
packagesinternal.SetModFlag(cfg, inv.ModFlag)
// We want to type check cgo code if go/types supports it.
if typesinternal.SetUsesCgo(&types.Config{}) {
cfg.Mode |= packages.LoadMode(packagesinternal.TypecheckCgo)
}
packagesinternal.SetGoCmdRunner(cfg, s.view.session.gocmdRunner)
return cfg
}
func (s *snapshot) RunGoCommandDirect(ctx context.Context, mode source.InvocationFlags, inv *gocommand.Invocation) (*bytes.Buffer, error) {
_, inv, cleanup, err := s.goCommandInvocation(ctx, mode, inv)
if err != nil {
return nil, err
}
defer cleanup()
return s.view.session.gocmdRunner.Run(ctx, *inv)
}
func (s *snapshot) RunGoCommandPiped(ctx context.Context, mode source.InvocationFlags, inv *gocommand.Invocation, stdout, stderr io.Writer) error {
_, inv, cleanup, err := s.goCommandInvocation(ctx, mode, inv)
if err != nil {
return err
}
defer cleanup()
return s.view.session.gocmdRunner.RunPiped(ctx, *inv, stdout, stderr)
}
func (s *snapshot) RunGoCommands(ctx context.Context, allowNetwork bool, wd string, run func(invoke func(...string) (*bytes.Buffer, error)) error) (bool, []byte, []byte, error) {
var flags source.InvocationFlags
if s.workspaceMode()&tempModfile != 0 {
flags = source.WriteTemporaryModFile
} else {
flags = source.Normal
}
if allowNetwork {
flags |= source.AllowNetwork
}
tmpURI, inv, cleanup, err := s.goCommandInvocation(ctx, flags, &gocommand.Invocation{WorkingDir: wd})
if err != nil {
return false, nil, nil, err
}
defer cleanup()
invoke := func(args ...string) (*bytes.Buffer, error) {
inv.Verb = args[0]
inv.Args = args[1:]
return s.view.session.gocmdRunner.Run(ctx, *inv)
}
if err := run(invoke); err != nil {
return false, nil, nil, err
}
if flags.Mode() != source.WriteTemporaryModFile {
return false, nil, nil, nil
}
var modBytes, sumBytes []byte
modBytes, err = ioutil.ReadFile(tmpURI.Filename())
if err != nil && !os.IsNotExist(err) {
return false, nil, nil, err
}
sumBytes, err = ioutil.ReadFile(strings.TrimSuffix(tmpURI.Filename(), ".mod") + ".sum")
if err != nil && !os.IsNotExist(err) {
return false, nil, nil, err
}
return true, modBytes, sumBytes, nil
}
func (s *snapshot) goCommandInvocation(ctx context.Context, flags source.InvocationFlags, inv *gocommand.Invocation) (tmpURI span.URI, updatedInv *gocommand.Invocation, cleanup func(), err error) {
s.view.optionsMu.Lock()
allowModfileModificationOption := s.view.options.AllowModfileModifications
allowNetworkOption := s.view.options.AllowImplicitNetworkAccess
inv.Env = append(append(append(os.Environ(), s.view.options.EnvSlice()...), inv.Env...), "GO111MODULE="+s.view.effectiveGo111Module)
inv.BuildFlags = append([]string{}, s.view.options.BuildFlags...)
s.view.optionsMu.Unlock()
cleanup = func() {} // fallback
// All logic below is for module mode.
if s.workspaceMode()&moduleMode == 0 {
return "", inv, cleanup, nil
}
mode, allowNetwork := flags.Mode(), flags.AllowNetwork()
if !allowNetwork && !allowNetworkOption {
inv.Env = append(inv.Env, "GOPROXY=off")
}
// What follows is rather complicated logic for how to actually run the go
// command. A word of warning: this is the result of various incremental
// features added to gopls, and varying behavior of the Go command across Go
// versions. It can surely be cleaned up significantly, but tread carefully.
//
// Roughly speaking we need to resolve four things:
// - the working directory.
// - the -mod flag
// - the -modfile flag
// - the -workfile flag
//
// These are dependent on a number of factors: whether we need to run in a
// synthetic workspace, whether flags are supported at the current go
// version, and what we're actually trying to achieve (the
// source.InvocationFlags).
var modURI span.URI
// Select the module context to use.
// If we're type checking, we need to use the workspace context, meaning
// the main (workspace) module. Otherwise, we should use the module for
// the passed-in working dir.
if mode == source.LoadWorkspace {
switch s.workspace.moduleSource {
case legacyWorkspace:
for m := range s.workspace.getActiveModFiles() { // range to access the only element
modURI = m
}
case goWorkWorkspace:
if s.view.goversion >= 18 {
break
}
// Before go 1.18, the Go command did not natively support go.work files,
// so we 'fake' them with a workspace module.
fallthrough
case fileSystemWorkspace, goplsModWorkspace:
var tmpDir span.URI
var err error
tmpDir, err = s.getWorkspaceDir(ctx)
if err != nil {
return "", nil, cleanup, err
}
inv.WorkingDir = tmpDir.Filename()
modURI = span.URIFromPath(filepath.Join(tmpDir.Filename(), "go.mod"))
}
} else {
modURI = s.GoModForFile(span.URIFromPath(inv.WorkingDir))
}
var modContent []byte
if modURI != "" {
modFH, err := s.GetFile(ctx, modURI)
if err != nil {
return "", nil, cleanup, err
}
modContent, err = modFH.Read()
if err != nil {
return "", nil, cleanup, err
}
}
vendorEnabled, err := s.vendorEnabled(ctx, modURI, modContent)
if err != nil {
return "", nil, cleanup, err
}
mutableModFlag := ""
// If the mod flag isn't set, populate it based on the mode and workspace.
if inv.ModFlag == "" {
if s.view.goversion >= 16 {
mutableModFlag = "mod"
}
switch mode {
case source.LoadWorkspace, source.Normal:
if vendorEnabled {
inv.ModFlag = "vendor"
} else if !allowModfileModificationOption {
inv.ModFlag = "readonly"
} else {
inv.ModFlag = mutableModFlag
}
case source.WriteTemporaryModFile:
inv.ModFlag = mutableModFlag
// -mod must be readonly when using go.work files - see issue #48941
inv.Env = append(inv.Env, "GOWORK=off")
}
}
// Only use a temp mod file if the modfile can actually be mutated.
needTempMod := inv.ModFlag == mutableModFlag
useTempMod := s.workspaceMode()&tempModfile != 0
if needTempMod && !useTempMod {
return "", nil, cleanup, source.ErrTmpModfileUnsupported
}
// We should use -workfile if:
// 1. We're not actively trying to mutate a modfile.
// 2. We have an active go.work file.
// 3. We're using at least Go 1.18.
useWorkFile := !needTempMod && s.workspace.moduleSource == goWorkWorkspace && s.view.goversion >= 18
if useWorkFile {
// TODO(#51215): build a temp workfile and set GOWORK in the environment.
} else if useTempMod {
if modURI == "" {
return "", nil, cleanup, fmt.Errorf("no go.mod file found in %s", inv.WorkingDir)
}
modFH, err := s.GetFile(ctx, modURI)
if err != nil {
return "", nil, cleanup, err
}
// Use the go.sum if it happens to be available.
gosum := s.goSum(ctx, modURI)
tmpURI, cleanup, err = tempModFile(modFH, gosum)
if err != nil {
return "", nil, cleanup, err
}
inv.ModFile = tmpURI.Filename()
}
return tmpURI, inv, cleanup, nil
}
func (s *snapshot) buildOverlay() map[string][]byte {
s.mu.Lock()
defer s.mu.Unlock()
overlays := make(map[string][]byte)
s.files.Range(func(uri span.URI, fh source.VersionedFileHandle) {
overlay, ok := fh.(*overlay)
if !ok {
return
}
if overlay.saved {
return
}
// TODO(rstambler): Make sure not to send overlays outside of the current view.
overlays[uri.Filename()] = overlay.text
})
return overlays
}
func hashUnsavedOverlays(files filesMap) source.Hash {
var unsaved []string
files.Range(func(uri span.URI, fh source.VersionedFileHandle) {
if overlay, ok := fh.(*overlay); ok && !overlay.saved {
unsaved = append(unsaved, uri.Filename())
}
})
sort.Strings(unsaved)
return source.Hashf("%s", unsaved)
}
func (s *snapshot) PackagesForFile(ctx context.Context, uri span.URI, mode source.TypecheckMode, includeTestVariants bool) ([]source.Package, error) {
ctx = event.Label(ctx, tag.URI.Of(uri))
phs, err := s.packageHandlesForFile(ctx, uri, mode, includeTestVariants)
if err != nil {
return nil, err
}
var pkgs []source.Package
for _, ph := range phs {
pkg, err := ph.check(ctx, s)
if err != nil {
return nil, err
}
pkgs = append(pkgs, pkg)
}
return pkgs, nil
}
func (s *snapshot) PackageForFile(ctx context.Context, uri span.URI, mode source.TypecheckMode, pkgPolicy source.PackageFilter) (source.Package, error) {
ctx = event.Label(ctx, tag.URI.Of(uri))
phs, err := s.packageHandlesForFile(ctx, uri, mode, false)
if err != nil {
return nil, err
}
if len(phs) < 1 {
return nil, fmt.Errorf("no packages")
}
ph := phs[0]
for _, handle := range phs[1:] {
switch pkgPolicy {
case source.WidestPackage:
if ph == nil || len(handle.CompiledGoFiles()) > len(ph.CompiledGoFiles()) {
ph = handle
}
case source.NarrowestPackage:
if ph == nil || len(handle.CompiledGoFiles()) < len(ph.CompiledGoFiles()) {
ph = handle
}
}
}
if ph == nil {
return nil, fmt.Errorf("no packages in input")
}
return ph.check(ctx, s)
}
func (s *snapshot) packageHandlesForFile(ctx context.Context, uri span.URI, mode source.TypecheckMode, includeTestVariants bool) ([]*packageHandle, error) {
// Check if we should reload metadata for the file. We don't invalidate IDs
// (though we should), so the IDs will be a better source of truth than the
// metadata. If there are no IDs for the file, then we should also reload.
fh, err := s.GetFile(ctx, uri)
if err != nil {
return nil, err
}
if kind := s.view.FileKind(fh); kind != source.Go {
return nil, fmt.Errorf("no packages for non-Go file %s (%v)", uri, kind)
}
knownIDs, err := s.getOrLoadIDsForURI(ctx, uri)
if err != nil {
return nil, err
}
var phs []*packageHandle
for _, id := range knownIDs {
// Filter out any intermediate test variants. We typically aren't
// interested in these packages for file= style queries.
if m := s.getMetadata(id); m != nil && m.IsIntermediateTestVariant && !includeTestVariants {
continue
}
var parseModes []source.ParseMode
switch mode {
case source.TypecheckAll:
if s.workspaceParseMode(id) == source.ParseFull {
parseModes = []source.ParseMode{source.ParseFull}
} else {
parseModes = []source.ParseMode{source.ParseExported, source.ParseFull}
}
case source.TypecheckFull:
parseModes = []source.ParseMode{source.ParseFull}
case source.TypecheckWorkspace:
parseModes = []source.ParseMode{s.workspaceParseMode(id)}
}
for _, parseMode := range parseModes {
ph, err := s.buildPackageHandle(ctx, id, parseMode)
if err != nil {
return nil, err
}
phs = append(phs, ph)
}
}
return phs, nil
}
func (s *snapshot) getOrLoadIDsForURI(ctx context.Context, uri span.URI) ([]PackageID, error) {
knownIDs := s.getIDsForURI(uri)
reload := len(knownIDs) == 0
for _, id := range knownIDs {
// Reload package metadata if any of the metadata has missing
// dependencies, in case something has changed since the last time we
// reloaded it.
if s.noValidMetadataForID(id) {
reload = true
break
}
// TODO(golang/go#36918): Previously, we would reload any package with
// missing dependencies. This is expensive and results in too many
// calls to packages.Load. Determine what we should do instead.
}
if reload {
err := s.load(ctx, false, fileURI(uri))
if !s.useInvalidMetadata() && err != nil {
return nil, err
}
// We've tried to reload and there are still no known IDs for the URI.
// Return the load error, if there was one.
knownIDs = s.getIDsForURI(uri)
if len(knownIDs) == 0 {
return nil, err
}
}
return knownIDs, nil
}
// Only use invalid metadata for Go versions >= 1.13. Go 1.12 and below has
// issues with overlays that will cause confusing error messages if we reuse
// old metadata.
func (s *snapshot) useInvalidMetadata() bool {
return s.view.goversion >= 13 && s.view.Options().ExperimentalUseInvalidMetadata
}
func (s *snapshot) GetReverseDependencies(ctx context.Context, id string) ([]source.Package, error) {
if err := s.awaitLoaded(ctx); err != nil {
return nil, err
}
s.mu.Lock()
meta := s.meta
s.mu.Unlock()
ids := meta.reverseTransitiveClosure(s.useInvalidMetadata(), PackageID(id))
// Make sure to delete the original package ID from the map.
delete(ids, PackageID(id))
var pkgs []source.Package
for id := range ids {
pkg, err := s.checkedPackage(ctx, id, s.workspaceParseMode(id))
if err != nil {
return nil, err
}
pkgs = append(pkgs, pkg)
}
return pkgs, nil
}
func (s *snapshot) checkedPackage(ctx context.Context, id PackageID, mode source.ParseMode) (*pkg, error) {
ph, err := s.buildPackageHandle(ctx, id, mode)
if err != nil {
return nil, err
}
return ph.check(ctx, s)
}
func (s *snapshot) getGoFile(key parseKey) *parseGoHandle {
s.mu.Lock()
defer s.mu.Unlock()
if result, ok := s.goFiles.Get(key); ok {
return result
}
return nil
}
func (s *snapshot) addGoFile(key parseKey, pgh *parseGoHandle, release func()) *parseGoHandle {
s.mu.Lock()
defer s.mu.Unlock()
if result, ok := s.goFiles.Get(key); ok {
release()
return result
}
s.goFiles.Set(key, pgh, release)
keys, _ := s.parseKeysByURI.Get(key.file.URI)
keys = append([]parseKey{key}, keys...)
s.parseKeysByURI.Set(key.file.URI, keys)
return pgh
}
func (s *snapshot) getParseModHandle(uri span.URI) *parseModHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.parseModHandles[uri]
}
func (s *snapshot) getParseWorkHandle(uri span.URI) *parseWorkHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.parseWorkHandles[uri]
}
func (s *snapshot) getModWhyHandle(uri span.URI) *modWhyHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.modWhyHandles[uri]
}
func (s *snapshot) getModTidyHandle(uri span.URI) *modTidyHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.modTidyHandles[uri]
}
func (s *snapshot) getImportedBy(id PackageID) []PackageID {
s.mu.Lock()
defer s.mu.Unlock()
return s.meta.importedBy[id]
}
func (s *snapshot) addPackageHandle(ph *packageHandle) *packageHandle {
s.mu.Lock()
defer s.mu.Unlock()
// If the package handle has already been cached,
// return the cached handle instead of overriding it.
if ph, ok := s.packages[ph.packageKey()]; ok {
return ph
}
s.packages[ph.packageKey()] = ph
return ph
}
func (s *snapshot) workspacePackageIDs() (ids []PackageID) {
s.mu.Lock()
defer s.mu.Unlock()
for id := range s.workspacePackages {
ids = append(ids, id)
}
return ids
}
func (s *snapshot) activePackageIDs() (ids []PackageID) {
if s.view.Options().MemoryMode == source.ModeNormal {
return s.workspacePackageIDs()
}
s.mu.Lock()
defer s.mu.Unlock()
seen := make(map[PackageID]bool)
for id := range s.workspacePackages {
if s.isActiveLocked(id, seen) {
ids = append(ids, id)
}
}
return ids
}
func (s *snapshot) isActiveLocked(id PackageID, seen map[PackageID]bool) (active bool) {
if seen == nil {
seen = make(map[PackageID]bool)
}
if seen, ok := seen[id]; ok {
return seen
}
defer func() {
seen[id] = active
}()
m, ok := s.meta.metadata[id]
if !ok {
return false
}
for _, cgf := range m.CompiledGoFiles {
if s.isOpenLocked(cgf) {
return true
}
}
// TODO(rfindley): it looks incorrect that we don't also check GoFiles here.
// If a CGo file is open, we want to consider the package active.
for _, dep := range m.Deps {
if s.isActiveLocked(dep, seen) {
return true
}
}
return false
}
const fileExtensions = "go,mod,sum,work"
func (s *snapshot) fileWatchingGlobPatterns(ctx context.Context) map[string]struct{} {
extensions := fileExtensions
for _, ext := range s.View().Options().TemplateExtensions {
extensions += "," + ext
}
// Work-around microsoft/vscode#100870 by making sure that we are,
// at least, watching the user's entire workspace. This will still be
// applied to every folder in the workspace.
patterns := map[string]struct{}{
fmt.Sprintf("**/*.{%s}", extensions): {},
}
// Add a pattern for each Go module in the workspace that is not within the view.
dirs := s.workspace.dirs(ctx, s)
for _, dir := range dirs {
dirName := dir.Filename()
// If the directory is within the view's folder, we're already watching
// it with the pattern above.
if source.InDir(s.view.folder.Filename(), dirName) {
continue
}
// TODO(rstambler): If microsoft/vscode#3025 is resolved before
// microsoft/vscode#101042, we will need a work-around for Windows
// drive letter casing.
patterns[fmt.Sprintf("%s/**/*.{%s}", dirName, extensions)] = struct{}{}
}
// Some clients do not send notifications for changes to directories that
// contain Go code (golang/go#42348). To handle this, explicitly watch all
// of the directories in the workspace. We find them by adding the
// directories of every file in the snapshot's workspace directories.
// There may be thousands.
if pattern := s.getKnownSubdirsPattern(dirs); pattern != "" {
patterns[pattern] = struct{}{}
}
return patterns
}
func (s *snapshot) getKnownSubdirsPattern(wsDirs []span.URI) string {
s.mu.Lock()
defer s.mu.Unlock()
// First, process any pending changes and update the set of known
// subdirectories.
// It may change list of known subdirs and therefore invalidate the cache.
s.applyKnownSubdirsChangesLocked(wsDirs)
if len(s.knownSubdirs) == 0 {
return ""
}
if s.knownSubdirsPatternCache == "" {
dirNames := make([]string, 0, len(s.knownSubdirs))
for uri := range s.knownSubdirs {
dirNames = append(dirNames, uri.Filename())
}
sort.Strings(dirNames)
s.knownSubdirsPatternCache = fmt.Sprintf("{%s}", strings.Join(dirNames, ","))
}
return s.knownSubdirsPatternCache
}
// collectAllKnownSubdirs collects all of the subdirectories within the
// snapshot's workspace directories. None of the workspace directories are
// included.
func (s *snapshot) collectAllKnownSubdirs(ctx context.Context) {
dirs := s.workspace.dirs(ctx, s)
s.mu.Lock()
defer s.mu.Unlock()
s.knownSubdirs = map[span.URI]struct{}{}
s.knownSubdirsPatternCache = ""
s.files.Range(func(uri span.URI, fh source.VersionedFileHandle) {
s.addKnownSubdirLocked(uri, dirs)
})
}
func (s *snapshot) getKnownSubdirs(wsDirs []span.URI) []span.URI {
s.mu.Lock()
defer s.mu.Unlock()
// First, process any pending changes and update the set of known
// subdirectories.
s.applyKnownSubdirsChangesLocked(wsDirs)
result := make([]span.URI, 0, len(s.knownSubdirs))
for uri := range s.knownSubdirs {
result = append(result, uri)
}
return result
}
func (s *snapshot) applyKnownSubdirsChangesLocked(wsDirs []span.URI) {
for _, c := range s.unprocessedSubdirChanges {
if c.isUnchanged {
continue
}
if !c.exists {
s.removeKnownSubdirLocked(c.fileHandle.URI())
} else {
s.addKnownSubdirLocked(c.fileHandle.URI(), wsDirs)
}
}
s.unprocessedSubdirChanges = nil
}
func (s *snapshot) addKnownSubdirLocked(uri span.URI, dirs []span.URI) {
dir := filepath.Dir(uri.Filename())
// First check if the directory is already known, because then we can
// return early.
if _, ok := s.knownSubdirs[span.URIFromPath(dir)]; ok {
return
}
var matched span.URI
for _, wsDir := range dirs {
if source.InDir(wsDir.Filename(), dir) {
matched = wsDir
break
}
}
// Don't watch any directory outside of the workspace directories.
if matched == "" {
return
}
for {
if dir == "" || dir == matched.Filename() {
break
}
uri := span.URIFromPath(dir)
if _, ok := s.knownSubdirs[uri]; ok {
break
}
s.knownSubdirs[uri] = struct{}{}
dir = filepath.Dir(dir)
s.knownSubdirsPatternCache = ""
}
}
func (s *snapshot) removeKnownSubdirLocked(uri span.URI) {
dir := filepath.Dir(uri.Filename())
for dir != "" {
uri := span.URIFromPath(dir)
if _, ok := s.knownSubdirs[uri]; !ok {
break
}
if info, _ := os.Stat(dir); info == nil {
delete(s.knownSubdirs, uri)
s.knownSubdirsPatternCache = ""
}
dir = filepath.Dir(dir)
}
}
// knownFilesInDir returns the files known to the given snapshot that are in
// the given directory. It does not respect symlinks.
func (s *snapshot) knownFilesInDir(ctx context.Context, dir span.URI) []span.URI {
var files []span.URI
s.mu.Lock()
defer s.mu.Unlock()
s.files.Range(func(uri span.URI, fh source.VersionedFileHandle) {
if source.InDir(dir.Filename(), uri.Filename()) {
files = append(files, uri)
}
})
return files
}
func (s *snapshot) workspacePackageHandles(ctx context.Context) ([]*packageHandle, error) {
if err := s.awaitLoaded(ctx); err != nil {
return nil, err
}
var phs []*packageHandle
for _, pkgID := range s.workspacePackageIDs() {
ph, err := s.buildPackageHandle(ctx, pkgID, s.workspaceParseMode(pkgID))
if err != nil {
return nil, err
}
phs = append(phs, ph)
}
return phs, nil
}
func (s *snapshot) ActivePackages(ctx context.Context) ([]source.Package, error) {
phs, err := s.activePackageHandles(ctx)
if err != nil {
return nil, err
}
var pkgs []source.Package
for _, ph := range phs {
pkg, err := ph.check(ctx, s)
if err != nil {
return nil, err
}
pkgs = append(pkgs, pkg)
}
return pkgs, nil
}
func (s *snapshot) activePackageHandles(ctx context.Context) ([]*packageHandle, error) {
if err := s.awaitLoaded(ctx); err != nil {
return nil, err
}
var phs []*packageHandle
for _, pkgID := range s.activePackageIDs() {
ph, err := s.buildPackageHandle(ctx, pkgID, s.workspaceParseMode(pkgID))
if err != nil {
return nil, err
}
phs = append(phs, ph)
}
return phs, nil
}
// Symbols extracts and returns the symbols for each file in all the snapshot's views.
func (s *snapshot) Symbols(ctx context.Context) map[span.URI][]source.Symbol {
var (
group errgroup.Group
nprocs = 2 * runtime.GOMAXPROCS(-1) // symbolize is a mix of I/O and CPU
iolimit = make(chan struct{}, nprocs) // I/O limiting counting semaphore
resultMu sync.Mutex
result = make(map[span.URI][]source.Symbol)
)
s.files.Range(func(uri span.URI, f source.VersionedFileHandle) {
if s.View().FileKind(f) != source.Go {
return // workspace symbols currently supports only Go files.
}
// TODO(adonovan): upgrade errgroup and use group.SetLimit(nprocs).
iolimit <- struct{}{} // acquire token
group.Go(func() error {
defer func() { <-iolimit }() // release token
v, err := s.buildSymbolHandle(ctx, f).handle.Get(ctx, s.generation, s)
if err != nil {
return err
}
resultMu.Lock()
result[uri] = v.(*symbolData).symbols
resultMu.Unlock()
return nil
})
})
// Keep going on errors, but log the first failure.
// Partial results are better than no symbol results.
if err := group.Wait(); err != nil {
event.Error(ctx, "getting snapshot symbols", err)
}
return result
}
func (s *snapshot) MetadataForFile(ctx context.Context, uri span.URI) ([]source.Metadata, error) {
knownIDs, err := s.getOrLoadIDsForURI(ctx, uri)
if err != nil {
return nil, err
}
var mds []source.Metadata
for _, id := range knownIDs {
md := s.getMetadata(id)
// TODO(rfindley): knownIDs and metadata should be in sync, but existing
// code is defensive of nil metadata.
if md != nil {
mds = append(mds, md)
}
}
return mds, nil
}
func (s *snapshot) KnownPackages(ctx context.Context) ([]source.Package, error) {
if err := s.awaitLoaded(ctx); err != nil {
return nil, err
}
// The WorkspaceSymbols implementation relies on this function returning
// workspace packages first.
ids := s.workspacePackageIDs()
s.mu.Lock()
for id := range s.meta.metadata {
if _, ok := s.workspacePackages[id]; ok {
continue
}
ids = append(ids, id)
}
s.mu.Unlock()
var pkgs []source.Package
for _, id := range ids {
pkg, err := s.checkedPackage(ctx, id, s.workspaceParseMode(id))
if err != nil {
return nil, err
}
pkgs = append(pkgs, pkg)
}
return pkgs, nil
}
func (s *snapshot) CachedImportPaths(ctx context.Context) (map[string]source.Package, error) {
// Don't reload workspace package metadata.
// This function is meant to only return currently cached information.
s.AwaitInitialized(ctx)
s.mu.Lock()
defer s.mu.Unlock()
results := map[string]source.Package{}
for _, ph := range s.packages {
cachedPkg, err := ph.cached(s.generation)
if err != nil {
continue
}
for importPath, newPkg := range cachedPkg.imports {
if oldPkg, ok := results[string(importPath)]; ok {
// Using the same trick as NarrowestPackage, prefer non-variants.
if len(newPkg.compiledGoFiles) < len(oldPkg.(*pkg).compiledGoFiles) {
results[string(importPath)] = newPkg
}
} else {
results[string(importPath)] = newPkg
}
}
}
return results, nil
}
func (s *snapshot) GoModForFile(uri span.URI) span.URI {
return moduleForURI(s.workspace.activeModFiles, uri)
}
func moduleForURI(modFiles map[span.URI]struct{}, uri span.URI) span.URI {
var match span.URI
for modURI := range modFiles {
if !source.InDir(dirURI(modURI).Filename(), uri.Filename()) {
continue
}
if len(modURI) > len(match) {
match = modURI
}
}
return match
}
func (s *snapshot) getPackage(id PackageID, mode source.ParseMode) *packageHandle {
s.mu.Lock()
defer s.mu.Unlock()
key := packageKey{
id: id,
mode: mode,
}
return s.packages[key]
}
func (s *snapshot) getSymbolHandle(uri span.URI) *symbolHandle {
s.mu.Lock()
defer s.mu.Unlock()
return s.symbols[uri]
}
func (s *snapshot) addSymbolHandle(uri span.URI, sh *symbolHandle) *symbolHandle {
s.mu.Lock()
defer s.mu.Unlock()
// If the package handle has already been cached,
// return the cached handle instead of overriding it.
if sh, ok := s.symbols[uri]; ok {
return sh
}
s.symbols[uri] = sh
return sh
}
func (s *snapshot) getActionHandle(id PackageID, m source.ParseMode, a *analysis.Analyzer) *actionHandle {
s.mu.Lock()
defer s.mu.Unlock()
key := actionKey{
pkg: packageKey{
id: id,
mode: m,
},
analyzer: a,
}
return s.actions[key]
}
func (s *snapshot) addActionHandle(ah *actionHandle) *actionHandle {
s.mu.Lock()
defer s.mu.Unlock()
key := actionKey{
analyzer: ah.analyzer,
pkg: packageKey{
id: ah.pkg.m.ID,
mode: ah.pkg.mode,
},
}
if ah, ok := s.actions[key]; ok {
return ah
}
s.actions[key] = ah
return ah
}
func (s *snapshot) getIDsForURI(uri span.URI) []PackageID {
s.mu.Lock()
defer s.mu.Unlock()
return s.meta.ids[uri]
}
func (s *snapshot) getMetadata(id PackageID) *KnownMetadata {
s.mu.Lock()
defer s.mu.Unlock()
return s.meta.metadata[id]
}
func (s *snapshot) shouldLoad(scope interface{}) bool {
s.mu.Lock()
defer s.mu.Unlock()
g := s.meta
switch scope := scope.(type) {
case PackagePath:
var meta *KnownMetadata
for _, m := range g.metadata {
if m.PkgPath != scope {
continue
}
meta = m
}
if meta == nil || meta.ShouldLoad {
return true
}
return false
case fileURI:
uri := span.URI(scope)
ids := g.ids[uri]
if len(ids) == 0 {
return true
}
for _, id := range ids {
m, ok := g.metadata[id]
if !ok || m.ShouldLoad {
return true
}
}
return false
default:
return true
}
}
func (s *snapshot) clearShouldLoad(scopes ...interface{}) {
s.mu.Lock()
defer s.mu.Unlock()
g := s.meta
var updates map[PackageID]*KnownMetadata
markLoaded := func(m *KnownMetadata) {
if updates == nil {
updates = make(map[PackageID]*KnownMetadata)
}
next := *m
next.ShouldLoad = false
updates[next.ID] = &next
}
for _, scope := range scopes {
switch scope := scope.(type) {
case PackagePath:
for _, m := range g.metadata {
if m.PkgPath == scope {
markLoaded(m)
}
}
case fileURI:
uri := span.URI(scope)
ids := g.ids[uri]
for _, id := range ids {
if m, ok := g.metadata[id]; ok {
markLoaded(m)
}
}
}
}
s.meta = g.Clone(updates)
}
// noValidMetadataForURILocked reports whether there is any valid metadata for
// the given URI.
func (s *snapshot) noValidMetadataForURILocked(uri span.URI) bool {
ids, ok := s.meta.ids[uri]
if !ok {
return true
}
for _, id := range ids {
if m, ok := s.meta.metadata[id]; ok && m.Valid {
return false
}
}
return true
}
// noValidMetadataForID reports whether there is no valid metadata for the
// given ID.
func (s *snapshot) noValidMetadataForID(id PackageID) bool {
s.mu.Lock()
defer s.mu.Unlock()
m := s.meta.metadata[id]
return m == nil || !m.Valid
}
func (s *snapshot) isWorkspacePackage(id PackageID) bool {
s.mu.Lock()
defer s.mu.Unlock()
_, ok := s.workspacePackages[id]
return ok
}
func (s *snapshot) FindFile(uri span.URI) source.VersionedFileHandle {
f := s.view.getFile(uri)
s.mu.Lock()
defer s.mu.Unlock()
result, _ := s.files.Get(f.URI())
return result
}
// GetVersionedFile returns a File for the given URI. If the file is unknown it
// is added to the managed set.
//
// GetVersionedFile succeeds even if the file does not exist. A non-nil error return
// indicates some type of internal error, for example if ctx is cancelled.
func (s *snapshot) GetVersionedFile(ctx context.Context, uri span.URI) (source.VersionedFileHandle, error) {
f := s.view.getFile(uri)
s.mu.Lock()
defer s.mu.Unlock()
return s.getFileLocked(ctx, f)
}
// GetFile implements the fileSource interface by wrapping GetVersionedFile.
func (s *snapshot) GetFile(ctx context.Context, uri span.URI) (source.FileHandle, error) {
return s.GetVersionedFile(ctx, uri)
}
func (s *snapshot) getFileLocked(ctx context.Context, f *fileBase) (source.VersionedFileHandle, error) {
if fh, ok := s.files.Get(f.URI()); ok {
return fh, nil
}
fh, err := s.view.session.cache.getFile(ctx, f.URI()) // read the file
if err != nil {
return nil, err
}
closed := &closedFile{fh}
s.files.Set(f.URI(), closed)
return closed, nil
}
func (s *snapshot) IsOpen(uri span.URI) bool {
s.mu.Lock()
defer s.mu.Unlock()
return s.isOpenLocked(uri)
}
func (s *snapshot) openFiles() []source.VersionedFileHandle {
s.mu.Lock()
defer s.mu.Unlock()
var open []source.VersionedFileHandle
s.files.Range(func(uri span.URI, fh source.VersionedFileHandle) {
if s.isOpenLocked(fh.URI()) {
open = append(open, fh)
}
})
return open
}
func (s *snapshot) isOpenLocked(uri span.URI) bool {
fh, _ := s.files.Get(uri)
_, open := fh.(*overlay)
return open
}
func (s *snapshot) awaitLoaded(ctx context.Context) error {
loadErr := s.awaitLoadedAllErrors(ctx)
s.mu.Lock()
defer s.mu.Unlock()
// If we still have absolutely no metadata, check if the view failed to
// initialize and return any errors.
if s.useInvalidMetadata() && len(s.meta.metadata) > 0 {
return nil
}
for _, m := range s.meta.metadata {
if m.Valid {
return nil
}
}
if loadErr != nil {
return loadErr.MainError
}
return nil
}
func (s *snapshot) GetCriticalError(ctx context.Context) *source.CriticalError {
loadErr := s.awaitLoadedAllErrors(ctx)
if loadErr != nil && errors.Is(loadErr.MainError, context.Canceled) {
return nil
}
// Even if packages didn't fail to load, we still may want to show
// additional warnings.
if loadErr == nil {
wsPkgs, _ := s.ActivePackages(ctx)
if msg := shouldShowAdHocPackagesWarning(s, wsPkgs); msg != "" {
return &source.CriticalError{
MainError: errors.New(msg),
}
}
// Even if workspace packages were returned, there still may be an error
// with the user's workspace layout. Workspace packages that only have the
// ID "command-line-arguments" are usually a symptom of a bad workspace
// configuration.
if containsCommandLineArguments(wsPkgs) {
return s.workspaceLayoutError(ctx)
}
return nil
}
if errMsg := loadErr.MainError.Error(); strings.Contains(errMsg, "cannot find main module") || strings.Contains(errMsg, "go.mod file not found") {
return s.workspaceLayoutError(ctx)
}
return loadErr
}
const adHocPackagesWarning = `You are outside of a module and outside of $GOPATH/src.
If you are using modules, please open your editor to a directory in your module.
If you believe this warning is incorrect, please file an issue: https://github.com/golang/go/issues/new.`
func shouldShowAdHocPackagesWarning(snapshot source.Snapshot, pkgs []source.Package) string {
if snapshot.ValidBuildConfiguration() {
return ""
}
for _, pkg := range pkgs {
if len(pkg.MissingDependencies()) > 0 {
return adHocPackagesWarning
}
}
return ""
}
func containsCommandLineArguments(pkgs []source.Package) bool {
for _, pkg := range pkgs {
if source.IsCommandLineArguments(pkg.ID()) {
return true
}
}
return false
}
func (s *snapshot) awaitLoadedAllErrors(ctx context.Context) *source.CriticalError {
// Do not return results until the snapshot's view has been initialized.
s.AwaitInitialized(ctx)
// TODO(rstambler): Should we be more careful about returning the
// initialization error? Is it possible for the initialization error to be
// corrected without a successful reinitialization?
s.mu.Lock()
initializedErr := s.initializedErr
s.mu.Unlock()
if initializedErr != nil {
return initializedErr
}
if ctx.Err() != nil {
return &source.CriticalError{MainError: ctx.Err()}
}
if err := s.reloadWorkspace(ctx); err != nil {
diags := s.extractGoCommandErrors(ctx, err)
return &source.CriticalError{
MainError: err,
DiagList: diags,
}
}
if err := s.reloadOrphanedFiles(ctx); err != nil {
diags := s.extractGoCommandErrors(ctx, err)
return &source.CriticalError{
MainError: err,
DiagList: diags,
}
}
return nil
}
func (s *snapshot) getInitializationError(ctx context.Context) *source.CriticalError {
s.mu.Lock()
defer s.mu.Unlock()
return s.initializedErr
}
func (s *snapshot) AwaitInitialized(ctx context.Context) {
select {
case <-ctx.Done():
return
case <-s.view.initialWorkspaceLoad:
}
// We typically prefer to run something as intensive as the IWL without
// blocking. I'm not sure if there is a way to do that here.
s.initialize(ctx, false)
}
// reloadWorkspace reloads the metadata for all invalidated workspace packages.
func (s *snapshot) reloadWorkspace(ctx context.Context) error {
// See which of the workspace packages are missing metadata.
s.mu.Lock()
missingMetadata := len(s.workspacePackages) == 0 || len(s.meta.metadata) == 0
pkgPathSet := map[PackagePath]struct{}{}
for id, pkgPath := range s.workspacePackages {
if m, ok := s.meta.metadata[id]; ok && m.Valid {
continue
}
missingMetadata = true
// Don't try to reload "command-line-arguments" directly.
if source.IsCommandLineArguments(string(pkgPath)) {
continue
}
pkgPathSet[pkgPath] = struct{}{}
}
s.mu.Unlock()
// If the view's build configuration is invalid, we cannot reload by
// package path. Just reload the directory instead.
if missingMetadata && !s.ValidBuildConfiguration() {
return s.load(ctx, false, viewLoadScope("LOAD_INVALID_VIEW"))
}
if len(pkgPathSet) == 0 {
return nil
}
var pkgPaths []interface{}
for pkgPath := range pkgPathSet {
pkgPaths = append(pkgPaths, pkgPath)
}
return s.load(ctx, false, pkgPaths...)
}
func (s *snapshot) reloadOrphanedFiles(ctx context.Context) error {
// When we load ./... or a package path directly, we may not get packages
// that exist only in overlays. As a workaround, we search all of the files
// available in the snapshot and reload their metadata individually using a
// file= query if the metadata is unavailable.
files := s.orphanedFiles()
// Files without a valid package declaration can't be loaded. Don't try.
var scopes []interface{}
for _, file := range files {
pgf, err := s.ParseGo(ctx, file, source.ParseHeader)
if err != nil {
continue
}
if !pgf.File.Package.IsValid() {
continue
}
scopes = append(scopes, fileURI(file.URI()))
}
if len(scopes) == 0 {
return nil
}
// The regtests match this exact log message, keep them in sync.
event.Log(ctx, "reloadOrphanedFiles reloading", tag.Query.Of(scopes))
err := s.load(ctx, false, scopes...)
// If we failed to load some files, i.e. they have no metadata,
// mark the failures so we don't bother retrying until the file's
// content changes.
//
// TODO(rstambler): This may be an overestimate if the load stopped
// early for an unrelated errors. Add a fallback?
//
// Check for context cancellation so that we don't incorrectly mark files
// as unloadable, but don't return before setting all workspace packages.
if ctx.Err() == nil && err != nil {
event.Error(ctx, "reloadOrphanedFiles: failed to load", err, tag.Query.Of(scopes))
s.mu.Lock()
for _, scope := range scopes {
uri := span.URI(scope.(fileURI))
if s.noValidMetadataForURILocked(uri) {
s.unloadableFiles[uri] = struct{}{}
}
}
s.mu.Unlock()
}
return nil
}
func (s *snapshot) orphanedFiles() []source.VersionedFileHandle {
s.mu.Lock()
defer s.mu.Unlock()
var files []source.VersionedFileHandle
s.files.Range(func(uri span.URI, fh source.VersionedFileHandle) {
// Don't try to reload metadata for go.mod files.
if s.view.FileKind(fh) != source.Go {
return
}
// If the URI doesn't belong to this view, then it's not in a workspace
// package and should not be reloaded directly.
if !contains(s.view.session.viewsOf(uri), s.view) {
return
}
// If the file is not open and is in a vendor directory, don't treat it
// like a workspace package.
if _, ok := fh.(*overlay); !ok && inVendor(uri) {
return
}
// Don't reload metadata for files we've already deemed unloadable.
if _, ok := s.unloadableFiles[uri]; ok {
return
}
if s.noValidMetadataForURILocked(uri) {
files = append(files, fh)
}
})
return files
}
func contains(views []*View, view *View) bool {
for _, v := range views {
if v == view {
return true
}
}
return false
}
func inVendor(uri span.URI) bool {
if !strings.Contains(string(uri), "/vendor/") {
return false
}
// Only packages in _subdirectories_ of /vendor/ are considered vendored
// (/vendor/a/foo.go is vendored, /vendor/foo.go is not).
split := strings.Split(string(uri), "/vendor/")
if len(split) < 2 {
return false
}
return strings.Contains(split[1], "/")
}
func generationName(v *View, snapshotID uint64) string {
return fmt.Sprintf("v%v/%v", v.id, snapshotID)
}
// unappliedChanges is a file source that handles an uncloned snapshot.
type unappliedChanges struct {
originalSnapshot *snapshot
changes map[span.URI]*fileChange
}
func (ac *unappliedChanges) GetFile(ctx context.Context, uri span.URI) (source.FileHandle, error) {
if c, ok := ac.changes[uri]; ok {
return c.fileHandle, nil
}
return ac.originalSnapshot.GetFile(ctx, uri)
}
func (s *snapshot) clone(ctx, bgCtx context.Context, changes map[span.URI]*fileChange, forceReloadMetadata bool) *snapshot {
ctx, done := event.Start(ctx, "snapshot.clone")
defer done()
var vendorChanged bool
newWorkspace, workspaceChanged, workspaceReload := s.workspace.invalidate(ctx, changes, &unappliedChanges{
originalSnapshot: s,
changes: changes,
})
s.mu.Lock()
defer s.mu.Unlock()
newGen := s.view.session.cache.store.Generation(generationName(s.view, s.id+1))
bgCtx, cancel := context.WithCancel(bgCtx)
result := &snapshot{
id: s.id + 1,
generation: newGen,
view: s.view,
backgroundCtx: bgCtx,
cancel: cancel,
builtin: s.builtin,
initializeOnce: s.initializeOnce,
initializedErr: s.initializedErr,
packages: make(map[packageKey]*packageHandle, len(s.packages)),
actions: make(map[actionKey]*actionHandle, len(s.actions)),
files: s.files.Clone(),
goFiles: s.goFiles.Clone(),
parseKeysByURI: s.parseKeysByURI.Clone(),
symbols: make(map[span.URI]*symbolHandle, len(s.symbols)),
workspacePackages: make(map[PackageID]PackagePath, len(s.workspacePackages)),
unloadableFiles: make(map[span.URI]struct{}, len(s.unloadableFiles)),
parseModHandles: make(map[span.URI]*parseModHandle, len(s.parseModHandles)),
parseWorkHandles: make(map[span.URI]*parseWorkHandle, len(s.parseWorkHandles)),
modTidyHandles: make(map[span.URI]*modTidyHandle, len(s.modTidyHandles)),
modWhyHandles: make(map[span.URI]*modWhyHandle, len(s.modWhyHandles)),
knownSubdirs: make(map[span.URI]struct{}, len(s.knownSubdirs)),
workspace: newWorkspace,
}
if !workspaceChanged && s.workspaceDirHandle != nil {
result.workspaceDirHandle = s.workspaceDirHandle
newGen.Inherit(s.workspaceDirHandle)
}
// Copy all of the FileHandles.
for k, v := range s.symbols {
if change, ok := changes[k]; ok {
if change.exists {
result.symbols[k] = result.buildSymbolHandle(ctx, change.fileHandle)
}
continue
}
newGen.Inherit(v.handle)
result.symbols[k] = v
}
// Copy the set of unloadable files.
for k, v := range s.unloadableFiles {
result.unloadableFiles[k] = v
}
// Copy all of the modHandles.
for k, v := range s.parseModHandles {
result.parseModHandles[k] = v
}
// Copy all of the parseWorkHandles.
for k, v := range s.parseWorkHandles {
result.parseWorkHandles[k] = v
}
for uri := range changes {
keys, ok := result.parseKeysByURI.Get(uri)
if ok {
for _, key := range keys {
result.goFiles.Delete(key)
}
result.parseKeysByURI.Delete(uri)
}
}
// Copy all of the go.mod-related handles. They may be invalidated later,
// so we inherit them at the end of the function.
for k, v := range s.modTidyHandles {
if _, ok := changes[k]; ok {
continue
}
result.modTidyHandles[k] = v
}
for k, v := range s.modWhyHandles {
if _, ok := changes[k]; ok {
continue
}
result.modWhyHandles[k] = v
}
// Add all of the known subdirectories, but don't update them for the
// changed files. We need to rebuild the workspace module to know the
// true set of known subdirectories, but we don't want to do that in clone.
for k, v := range s.knownSubdirs {
result.knownSubdirs[k] = v
}
result.knownSubdirsPatternCache = s.knownSubdirsPatternCache
for _, c := range changes {
result.unprocessedSubdirChanges = append(result.unprocessedSubdirChanges, c)
}
// directIDs keeps track of package IDs that have directly changed.
// It maps id->invalidateMetadata.
directIDs := map[PackageID]bool{}
// Invalidate all package metadata if the workspace module has changed.
if workspaceReload {
for k := range s.meta.metadata {
directIDs[k] = true
}
}
// Compute invalidations based on file changes.
changedPkgFiles := map[PackageID]bool{} // packages whose file set may have changed
anyImportDeleted := false
anyFileOpenedOrClosed := false
for uri, change := range changes {
// Maybe reinitialize the view if we see a change in the vendor
// directory.
if inVendor(uri) {
vendorChanged = true
}
// The original FileHandle for this URI is cached on the snapshot.
originalFH, _ := s.files.Get(uri)
var originalOpen, newOpen bool
_, originalOpen = originalFH.(*overlay)
_, newOpen = change.fileHandle.(*overlay)
anyFileOpenedOrClosed = originalOpen != newOpen
// If uri is a Go file, check if it has changed in a way that would
// invalidate metadata. Note that we can't use s.view.FileKind here,
// because the file type that matters is not what the *client* tells us,
// but what the Go command sees.
var invalidateMetadata, pkgFileChanged, importDeleted bool
if strings.HasSuffix(uri.Filename(), ".go") {
invalidateMetadata, pkgFileChanged, importDeleted = metadataChanges(ctx, s, originalFH, change.fileHandle)
}
invalidateMetadata = invalidateMetadata || forceReloadMetadata || workspaceReload
anyImportDeleted = anyImportDeleted || importDeleted
// Mark all of the package IDs containing the given file.
filePackageIDs := invalidatedPackageIDs(uri, s.meta.ids, pkgFileChanged)
if pkgFileChanged {
for id := range filePackageIDs {
changedPkgFiles[id] = true
}
}
for id := range filePackageIDs {
directIDs[id] = directIDs[id] || invalidateMetadata
}
// Invalidate the previous modTidyHandle if any of the files have been
// saved or if any of the metadata has been invalidated.
if invalidateMetadata || fileWasSaved(originalFH, change.fileHandle) {
// TODO(rstambler): Only delete mod handles for which the
// withoutURI is relevant.
for k := range s.modTidyHandles {
delete(result.modTidyHandles, k)
}
for k := range s.modWhyHandles {
delete(result.modWhyHandles, k)
}
}
delete(result.parseModHandles, uri)
delete(result.parseWorkHandles, uri)
// Handle the invalidated file; it may have new contents or not exist.
if !change.exists {
result.files.Delete(uri)
} else {
result.files.Set(uri, change.fileHandle)
}
// Make sure to remove the changed file from the unloadable set.
delete(result.unloadableFiles, uri)
}
// Deleting an import can cause list errors due to import cycles to be
// resolved. The best we can do without parsing the list error message is to
// hope that list errors may have been resolved by a deleted import.
//
// We could do better by parsing the list error message. We already do this
// to assign a better range to the list error, but for such critical
// functionality as metadata, it's better to be conservative until it proves
// impractical.
//
// We could also do better by looking at which imports were deleted and
// trying to find cycles they are involved in. This fails when the file goes
// from an unparseable state to a parseable state, as we don't have a
// starting point to compare with.
if anyImportDeleted {
for id, metadata := range s.meta.metadata {
if len(metadata.Errors) > 0 {
directIDs[id] = true
}
}
}
// Invalidate reverse dependencies too.
// idsToInvalidate keeps track of transitive reverse dependencies.
// If an ID is present in the map, invalidate its types.
// If an ID's value is true, invalidate its metadata too.
idsToInvalidate := map[PackageID]bool{}
var addRevDeps func(PackageID, bool)
addRevDeps = func(id PackageID, invalidateMetadata bool) {
current, seen := idsToInvalidate[id]
newInvalidateMetadata := current || invalidateMetadata
// If we've already seen this ID, and the value of invalidate
// metadata has not changed, we can return early.
if seen && current == newInvalidateMetadata {
return
}
idsToInvalidate[id] = newInvalidateMetadata
for _, rid := range s.meta.importedBy[id] {
addRevDeps(rid, invalidateMetadata)
}
}
for id, invalidateMetadata := range directIDs {
addRevDeps(id, invalidateMetadata)
}
// Copy the package type information.
for k, v := range s.packages {
if _, ok := idsToInvalidate[k.id]; ok {
continue
}
newGen.Inherit(v.handle)
result.packages[k] = v
}
// Copy the package analysis information.
for k, v := range s.actions {
if _, ok := idsToInvalidate[k.pkg.id]; ok {
continue
}
newGen.Inherit(v.handle)
result.actions[k] = v
}
// If the workspace mode has changed, we must delete all metadata, as it
// is unusable and may produce confusing or incorrect diagnostics.
// If a file has been deleted, we must delete metadata for all packages
// containing that file.
workspaceModeChanged := s.workspaceMode() != result.workspaceMode()
// Don't keep package metadata for packages that have lost files.
//
// TODO(rfindley): why not keep invalid metadata in this case? If we
// otherwise allow operate on invalid metadata, why not continue to do so,
// skipping the missing file?
skipID := map[PackageID]bool{}
for _, c := range changes {
if c.exists {
continue
}
// The file has been deleted.
if ids, ok := s.meta.ids[c.fileHandle.URI()]; ok {
for _, id := range ids {
skipID[id] = true
}
}
}
// Compute which metadata updates are required. We only need to invalidate
// packages directly containing the affected file, and only if it changed in
// a relevant way.
metadataUpdates := make(map[PackageID]*KnownMetadata)
deleteInvalidMetadata := forceReloadMetadata || workspaceModeChanged
for k, v := range s.meta.metadata {
invalidateMetadata := idsToInvalidate[k]
if skipID[k] || (invalidateMetadata && deleteInvalidMetadata) {
metadataUpdates[k] = nil
continue
}
valid := v.Valid && !invalidateMetadata
pkgFilesChanged := v.PkgFilesChanged || changedPkgFiles[k]
shouldLoad := v.ShouldLoad || invalidateMetadata
if valid != v.Valid || pkgFilesChanged != v.PkgFilesChanged || shouldLoad != v.ShouldLoad {
// Mark invalidated metadata rather than deleting it outright.
metadataUpdates[k] = &KnownMetadata{
Metadata: v.Metadata,
Valid: valid,
PkgFilesChanged: pkgFilesChanged,
ShouldLoad: shouldLoad,
}
}
}
// Update metadata, if necessary.
if len(metadataUpdates) > 0 {
result.meta = s.meta.Clone(metadataUpdates)
} else {
// No metadata changes. Since metadata is only updated by cloning, it is
// safe to re-use the existing metadata here.
result.meta = s.meta
}
// Update workspace packages, if necessary.
if result.meta != s.meta || anyFileOpenedOrClosed {
result.workspacePackages = computeWorkspacePackagesLocked(result, result.meta)
} else {
result.workspacePackages = s.workspacePackages
}
// Inherit all of the go.mod-related handles.
for _, v := range result.modTidyHandles {
newGen.Inherit(v.handle)
}
for _, v := range result.modWhyHandles {
newGen.Inherit(v.handle)
}
for _, v := range result.parseModHandles {
newGen.Inherit(v.handle)
}
for _, v := range result.parseWorkHandles {
newGen.Inherit(v.handle)
}
// Don't bother copying the importedBy graph,
// as it changes each time we update metadata.
// If the snapshot's workspace mode has changed, the packages loaded using
// the previous mode are no longer relevant, so clear them out.
if workspaceModeChanged {
result.workspacePackages = map[PackageID]PackagePath{}
}
// The snapshot may need to be reinitialized.
if workspaceReload || vendorChanged {
if workspaceChanged || result.initializedErr != nil {
result.initializeOnce = &sync.Once{}
}
}
result.dumpWorkspace("clone")
return result
}
// invalidatedPackageIDs returns all packages invalidated by a change to uri.
// If we haven't seen this URI before, we guess based on files in the same
// directory. This is of course incorrect in build systems where packages are
// not organized by directory.
//
// If packageFileChanged is set, the file is either a new file, or has a new
// package name. In this case, all known packages in the directory will be
// invalidated.
func invalidatedPackageIDs(uri span.URI, known map[span.URI][]PackageID, packageFileChanged bool) map[PackageID]struct{} {
invalidated := make(map[PackageID]struct{})
// At a minimum, we invalidate packages known to contain uri.
for _, id := range known[uri] {
invalidated[id] = struct{}{}
}
// If the file didn't move to a new package, we should only invalidate the
// packages it is currently contained inside.
if !packageFileChanged && len(invalidated) > 0 {
return invalidated
}
// This is a file we don't yet know about, or which has moved packages. Guess
// relevant packages by considering files in the same directory.
// Cache of FileInfo to avoid unnecessary stats for multiple files in the
// same directory.
stats := make(map[string]struct {
os.FileInfo
error
})
getInfo := func(dir string) (os.FileInfo, error) {
if res, ok := stats[dir]; ok {
return res.FileInfo, res.error
}
fi, err := os.Stat(dir)
stats[dir] = struct {
os.FileInfo
error
}{fi, err}
return fi, err
}
dir := filepath.Dir(uri.Filename())
fi, err := getInfo(dir)
if err == nil {
// Aggregate all possibly relevant package IDs.
for knownURI, ids := range known {
knownDir := filepath.Dir(knownURI.Filename())
knownFI, err := getInfo(knownDir)
if err != nil {
continue
}
if os.SameFile(fi, knownFI) {
for _, id := range ids {
invalidated[id] = struct{}{}
}
}
}
}
return invalidated
}
// fileWasSaved reports whether the FileHandle passed in has been saved. It
// accomplishes this by checking to see if the original and current FileHandles
// are both overlays, and if the current FileHandle is saved while the original
// FileHandle was not saved.
func fileWasSaved(originalFH, currentFH source.FileHandle) bool {
c, ok := currentFH.(*overlay)
if !ok || c == nil {
return true
}
o, ok := originalFH.(*overlay)
if !ok || o == nil {
return c.saved
}
return !o.saved && c.saved
}
// metadataChanges detects features of the change from oldFH->newFH that may
// affect package metadata.
//
// It uses lockedSnapshot to access cached parse information. lockedSnapshot
// must be locked.
//
// The result parameters have the following meaning:
// - invalidate means that package metadata for packages containing the file
// should be invalidated.
// - pkgFileChanged means that the file->package associates for the file have
// changed (possibly because the file is new, or because its package name has
// changed).
// - importDeleted means that an import has been deleted, or we can't
// determine if an import was deleted due to errors.
func metadataChanges(ctx context.Context, lockedSnapshot *snapshot, oldFH, newFH source.FileHandle) (invalidate, pkgFileChanged, importDeleted bool) {
if oldFH == nil || newFH == nil { // existential changes
changed := (oldFH == nil) != (newFH == nil)
return changed, changed, (newFH == nil) // we don't know if an import was deleted
}
// If the file hasn't changed, there's no need to reload.
if oldFH.FileIdentity() == newFH.FileIdentity() {
return false, false, false
}
// Parse headers to compare package names and imports.
oldHead, oldErr := peekOrParse(ctx, lockedSnapshot, oldFH, source.ParseHeader)
newHead, newErr := peekOrParse(ctx, lockedSnapshot, newFH, source.ParseHeader)
if oldErr != nil || newErr != nil {
// TODO(rfindley): we can get here if newFH does not exists. There is
// asymmetry here, in that newFH may be non-nil even if the underlying file
// does not exist.
//
// We should not produce a non-nil filehandle for a file that does not exist.
errChanged := (oldErr == nil) != (newErr == nil)
return errChanged, errChanged, (newErr != nil) // we don't know if an import was deleted
}
// `go list` fails completely if the file header cannot be parsed. If we go
// from a non-parsing state to a parsing state, we should reload.
if oldHead.ParseErr != nil && newHead.ParseErr == nil {
return true, true, true // We don't know what changed, so fall back on full invalidation.
}
// If a package name has changed, the set of package imports may have changed
// in ways we can't detect here. Assume an import has been deleted.
if oldHead.File.Name.Name != newHead.File.Name.Name {
return true, true, true
}
// Check whether package imports have changed. Only consider potentially
// valid imports paths.
oldImports := validImports(oldHead.File.Imports)
newImports := validImports(newHead.File.Imports)
for path := range newImports {
if _, ok := oldImports[path]; ok {
delete(oldImports, path)
} else {
invalidate = true // a new, potentially valid import was added
}
}
if len(oldImports) > 0 {
invalidate = true
importDeleted = true
}
// If the change does not otherwise invalidate metadata, get the full ASTs in
// order to check magic comments.
//
// Note: if this affects performance we can probably avoid parsing in the
// common case by first scanning the source for potential comments.
if !invalidate {
origFull, oldErr := peekOrParse(ctx, lockedSnapshot, oldFH, source.ParseFull)
currFull, newErr := peekOrParse(ctx, lockedSnapshot, newFH, source.ParseFull)
if oldErr == nil && newErr == nil {
invalidate = magicCommentsChanged(origFull.File, currFull.File)
} else {
// At this point, we shouldn't ever fail to produce a ParsedGoFile, as
// we're already past header parsing.
bug.Reportf("metadataChanges: unparseable file %v (old error: %v, new error: %v)", oldFH.URI(), oldErr, newErr)
}
}
return invalidate, pkgFileChanged, importDeleted
}
// peekOrParse returns the cached ParsedGoFile if it exists, otherwise parses
// without caching.
//
// It returns an error if the file could not be read (note that parsing errors
// are stored in ParsedGoFile.ParseErr).
//
// lockedSnapshot must be locked.
func peekOrParse(ctx context.Context, lockedSnapshot *snapshot, fh source.FileHandle, mode source.ParseMode) (*source.ParsedGoFile, error) {
key := parseKey{file: fh.FileIdentity(), mode: mode}
if pgh, ok := lockedSnapshot.goFiles.Get(key); ok {
cached := pgh.handle.Cached(lockedSnapshot.generation)
if cached != nil {
cached := cached.(*parseGoData)
if cached.parsed != nil {
return cached.parsed, nil
}
}
}
fset := token.NewFileSet()
data := parseGo(ctx, fset, fh, mode)
return data.parsed, data.err
}
func magicCommentsChanged(original *ast.File, current *ast.File) bool {
oldComments := extractMagicComments(original)
newComments := extractMagicComments(current)
if len(oldComments) != len(newComments) {
return true
}
for i := range oldComments {
if oldComments[i] != newComments[i] {
return true
}
}
return false
}
// validImports extracts the set of valid import paths from imports.
func validImports(imports []*ast.ImportSpec) map[string]struct{} {
m := make(map[string]struct{})
for _, spec := range imports {
if path := spec.Path.Value; validImportPath(path) {
m[path] = struct{}{}
}
}
return m
}
func validImportPath(path string) bool {
path, err := strconv.Unquote(path)
if err != nil {
return false
}
if path == "" {
return false
}
if path[len(path)-1] == '/' {
return false
}
return true
}
var buildConstraintOrEmbedRe = regexp.MustCompile(`^//(go:embed|go:build|\s*\+build).*`)
// extractMagicComments finds magic comments that affect metadata in f.
func extractMagicComments(f *ast.File) []string {
var results []string
for _, cg := range f.Comments {
for _, c := range cg.List {
if buildConstraintOrEmbedRe.MatchString(c.Text) {
results = append(results, c.Text)
}
}
}
return results
}
func (s *snapshot) BuiltinFile(ctx context.Context) (*source.ParsedGoFile, error) {
s.AwaitInitialized(ctx)
s.mu.Lock()
builtin := s.builtin
s.mu.Unlock()
if builtin == "" {
return nil, fmt.Errorf("no builtin package for view %s", s.view.name)
}
fh, err := s.GetFile(ctx, builtin)
if err != nil {
return nil, err
}
return s.ParseGo(ctx, fh, source.ParseFull)
}
func (s *snapshot) IsBuiltin(ctx context.Context, uri span.URI) bool {
s.mu.Lock()
defer s.mu.Unlock()
// We should always get the builtin URI in a canonical form, so use simple
// string comparison here. span.CompareURI is too expensive.
return uri == s.builtin
}
func (s *snapshot) setBuiltin(path string) {
s.mu.Lock()
defer s.mu.Unlock()
s.builtin = span.URIFromPath(path)
}
// BuildGoplsMod generates a go.mod file for all modules in the workspace. It
// bypasses any existing gopls.mod.
func (s *snapshot) BuildGoplsMod(ctx context.Context) (*modfile.File, error) {
allModules, err := findModules(s.view.folder, pathExcludedByFilterFunc(s.view.rootURI.Filename(), s.view.gomodcache, s.View().Options()), 0)
if err != nil {
return nil, err
}
return buildWorkspaceModFile(ctx, allModules, s)
}
// TODO(rfindley): move this to workspacemodule.go
func buildWorkspaceModFile(ctx context.Context, modFiles map[span.URI]struct{}, fs source.FileSource) (*modfile.File, error) {
file := &modfile.File{}
file.AddModuleStmt("gopls-workspace")
// Track the highest Go version, to be set on the workspace module.
// Fall back to 1.12 -- old versions insist on having some version.
goVersion := "1.12"
paths := map[string]span.URI{}
excludes := map[string][]string{}
var sortedModURIs []span.URI
for uri := range modFiles {
sortedModURIs = append(sortedModURIs, uri)
}
sort.Slice(sortedModURIs, func(i, j int) bool {
return sortedModURIs[i] < sortedModURIs[j]
})
for _, modURI := range sortedModURIs {
fh, err := fs.GetFile(ctx, modURI)
if err != nil {
return nil, err
}
content, err := fh.Read()
if err != nil {
return nil, err
}
parsed, err := modfile.Parse(fh.URI().Filename(), content, nil)
if err != nil {
return nil, err
}
if file == nil || parsed.Module == nil {
return nil, fmt.Errorf("no module declaration for %s", modURI)
}
// Prepend "v" to go versions to make them valid semver.
if parsed.Go != nil && semver.Compare("v"+goVersion, "v"+parsed.Go.Version) < 0 {
goVersion = parsed.Go.Version
}
path := parsed.Module.Mod.Path
if _, ok := paths[path]; ok {
return nil, fmt.Errorf("found module %q twice in the workspace", path)
}
paths[path] = modURI
// If the module's path includes a major version, we expect it to have
// a matching major version.
_, majorVersion, _ := module.SplitPathVersion(path)
if majorVersion == "" {
majorVersion = "/v0"
}
majorVersion = strings.TrimLeft(majorVersion, "/.") // handle gopkg.in versions
file.AddNewRequire(path, source.WorkspaceModuleVersion(majorVersion), false)
if err := file.AddReplace(path, "", dirURI(modURI).Filename(), ""); err != nil {
return nil, err
}
for _, exclude := range parsed.Exclude {
excludes[exclude.Mod.Path] = append(excludes[exclude.Mod.Path], exclude.Mod.Version)
}
}
if goVersion != "" {
file.AddGoStmt(goVersion)
}
// Go back through all of the modules to handle any of their replace
// statements.
for _, modURI := range sortedModURIs {
fh, err := fs.GetFile(ctx, modURI)
if err != nil {
return nil, err
}
content, err := fh.Read()
if err != nil {
return nil, err
}
parsed, err := modfile.Parse(fh.URI().Filename(), content, nil)
if err != nil {
return nil, err
}
// If any of the workspace modules have replace directives, they need
// to be reflected in the workspace module.
for _, rep := range parsed.Replace {
// Don't replace any modules that are in our workspace--we should
// always use the version in the workspace.
if _, ok := paths[rep.Old.Path]; ok {
continue
}
newPath := rep.New.Path
newVersion := rep.New.Version
// If a replace points to a module in the workspace, make sure we
// direct it to version of the module in the workspace.
if m, ok := paths[rep.New.Path]; ok {
newPath = dirURI(m).Filename()
newVersion = ""
} else if rep.New.Version == "" && !filepath.IsAbs(rep.New.Path) {
// Make any relative paths absolute.
newPath = filepath.Join(dirURI(modURI).Filename(), rep.New.Path)
}
if err := file.AddReplace(rep.Old.Path, rep.Old.Version, newPath, newVersion); err != nil {
return nil, err
}
}
}
for path, versions := range excludes {
for _, version := range versions {
file.AddExclude(path, version)
}
}
file.SortBlocks()
return file, nil
}
func buildWorkspaceSumFile(ctx context.Context, modFiles map[span.URI]struct{}, fs source.FileSource) ([]byte, error) {
allSums := map[module.Version][]string{}
for modURI := range modFiles {
// TODO(rfindley): factor out this pattern into a uripath package.
sumURI := span.URIFromPath(filepath.Join(filepath.Dir(modURI.Filename()), "go.sum"))
fh, err := fs.GetFile(ctx, sumURI)
if err != nil {
continue
}
data, err := fh.Read()
if os.IsNotExist(err) {
continue
}
if err != nil {
return nil, fmt.Errorf("reading go sum: %w", err)
}
if err := readGoSum(allSums, sumURI.Filename(), data); err != nil {
return nil, err
}
}
// This logic to write go.sum is copied (with minor modifications) from
// https://cs.opensource.google/go/go/+/master:src/cmd/go/internal/modfetch/fetch.go;l=631;drc=762eda346a9f4062feaa8a9fc0d17d72b11586f0
var mods []module.Version
for m := range allSums {
mods = append(mods, m)
}
module.Sort(mods)
var buf bytes.Buffer
for _, m := range mods {
list := allSums[m]
sort.Strings(list)
// Note (rfindley): here we add all sum lines without verification, because
// the assumption is that if they come from a go.sum file, they are
// trusted.
for _, h := range list {
fmt.Fprintf(&buf, "%s %s %s\n", m.Path, m.Version, h)
}
}
return buf.Bytes(), nil
}
// readGoSum is copied (with minor modifications) from
// https://cs.opensource.google/go/go/+/master:src/cmd/go/internal/modfetch/fetch.go;l=398;drc=762eda346a9f4062feaa8a9fc0d17d72b11586f0
func readGoSum(dst map[module.Version][]string, file string, data []byte) error {
lineno := 0
for len(data) > 0 {
var line []byte
lineno++
i := bytes.IndexByte(data, '\n')
if i < 0 {
line, data = data, nil
} else {
line, data = data[:i], data[i+1:]
}
f := strings.Fields(string(line))
if len(f) == 0 {
// blank line; skip it
continue
}
if len(f) != 3 {
return fmt.Errorf("malformed go.sum:\n%s:%d: wrong number of fields %v", file, lineno, len(f))
}
mod := module.Version{Path: f[0], Version: f[1]}
dst[mod] = append(dst[mod], f[2])
}
return nil
}