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// Copyright 2020 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 (
"context"
"fmt"
"go/ast"
"io/ioutil"
"os"
"path/filepath"
"sort"
"strconv"
"strings"
"golang.org/x/mod/modfile"
"golang.org/x/tools/internal/event"
"golang.org/x/tools/internal/gocommand"
"golang.org/x/tools/internal/lsp/debug/tag"
"golang.org/x/tools/internal/lsp/diff"
"golang.org/x/tools/internal/lsp/protocol"
"golang.org/x/tools/internal/lsp/source"
"golang.org/x/tools/internal/memoize"
"golang.org/x/tools/internal/span"
)
type modTidyKey struct {
sessionID string
env string
gomod source.FileIdentity
imports string
unsavedOverlays string
view string
}
type modTidyHandle struct {
handle *memoize.Handle
}
type modTidyData struct {
tidied *source.TidiedModule
err error
}
func (mth *modTidyHandle) tidy(ctx context.Context, snapshot *snapshot) (*source.TidiedModule, error) {
v, err := mth.handle.Get(ctx, snapshot.generation, snapshot)
if err != nil {
return nil, err
}
data := v.(*modTidyData)
return data.tidied, data.err
}
func (s *snapshot) ModTidy(ctx context.Context, fh source.FileHandle) (*source.TidiedModule, error) {
if fh.Kind() != source.Mod {
return nil, fmt.Errorf("%s is not a go.mod file", fh.URI())
}
if handle := s.getModTidyHandle(fh.URI()); handle != nil {
return handle.tidy(ctx, s)
}
// If the file handle is an overlay, it may not be written to disk.
// The go.mod file has to be on disk for `go mod tidy` to work.
if _, ok := fh.(*overlay); ok {
if info, _ := os.Stat(fh.URI().Filename()); info == nil {
return nil, source.ErrNoModOnDisk
}
}
workspacePkgs, err := s.WorkspacePackages(ctx)
if err != nil {
return nil, err
}
importHash, err := hashImports(ctx, workspacePkgs)
if err != nil {
return nil, err
}
s.mu.Lock()
overlayHash := hashUnsavedOverlays(s.files)
s.mu.Unlock()
key := modTidyKey{
sessionID: s.view.session.id,
view: s.view.folder.Filename(),
imports: importHash,
unsavedOverlays: overlayHash,
gomod: fh.FileIdentity(),
env: hashEnv(s),
}
h := s.generation.Bind(key, func(ctx context.Context, arg memoize.Arg) interface{} {
ctx, done := event.Start(ctx, "cache.ModTidyHandle", tag.URI.Of(fh.URI()))
defer done()
snapshot := arg.(*snapshot)
pm, err := snapshot.ParseMod(ctx, fh)
if err != nil || len(pm.ParseErrors) > 0 {
if err == nil {
err = fmt.Errorf("could not parse module to tidy: %v", pm.ParseErrors)
}
var errors []source.Error
if pm != nil {
errors = pm.ParseErrors
}
return &modTidyData{
tidied: &source.TidiedModule{
Parsed: pm,
Errors: errors,
},
err: err,
}
}
inv := &gocommand.Invocation{
Verb: "mod",
Args: []string{"tidy"},
WorkingDir: filepath.Dir(fh.URI().Filename()),
}
tmpURI, inv, cleanup, err := snapshot.goCommandInvocation(ctx, source.WriteTemporaryModFile, inv)
if err != nil {
return &modTidyData{err: err}
}
// Keep the temporary go.mod file around long enough to parse it.
defer cleanup()
if _, err := s.view.session.gocmdRunner.Run(ctx, *inv); err != nil {
return &modTidyData{err: err}
}
// Go directly to disk to get the temporary mod file, since it is
// always on disk.
tempContents, err := ioutil.ReadFile(tmpURI.Filename())
if err != nil {
return &modTidyData{err: err}
}
ideal, err := modfile.Parse(tmpURI.Filename(), tempContents, nil)
if err != nil {
// We do not need to worry about the temporary file's parse errors
// since it has been "tidied".
return &modTidyData{err: err}
}
// Compare the original and tidied go.mod files to compute errors and
// suggested fixes.
errors, err := modTidyErrors(ctx, snapshot, pm, ideal, workspacePkgs)
if err != nil {
return &modTidyData{err: err}
}
return &modTidyData{
tidied: &source.TidiedModule{
Errors: errors,
Parsed: pm,
TidiedContent: tempContents,
},
}
})
mth := &modTidyHandle{handle: h}
s.mu.Lock()
s.modTidyHandles[fh.URI()] = mth
s.mu.Unlock()
return mth.tidy(ctx, s)
}
func hashImports(ctx context.Context, wsPackages []source.Package) (string, error) {
results := make(map[string]bool)
var imports []string
for _, pkg := range wsPackages {
for _, path := range pkg.Imports() {
imp := path.PkgPath()
if _, ok := results[imp]; !ok {
results[imp] = true
imports = append(imports, imp)
}
}
}
sort.Strings(imports)
hashed := strings.Join(imports, ",")
return hashContents([]byte(hashed)), nil
}
// modTidyErrors computes the differences between the original and tidied
// go.mod files to produce diagnostic and suggested fixes. Some diagnostics
// may appear on the Go files that import packages from missing modules.
func modTidyErrors(ctx context.Context, snapshot source.Snapshot, pm *source.ParsedModule, ideal *modfile.File, workspacePkgs []source.Package) (errors []source.Error, err error) {
// First, determine which modules are unused and which are missing from the
// original go.mod file.
var (
unused = make(map[string]*modfile.Require, len(pm.File.Require))
missing = make(map[string]*modfile.Require, len(ideal.Require))
wrongDirectness = make(map[string]*modfile.Require, len(pm.File.Require))
)
for _, req := range pm.File.Require {
unused[req.Mod.Path] = req
}
for _, req := range ideal.Require {
origReq := unused[req.Mod.Path]
if origReq == nil {
missing[req.Mod.Path] = req
continue
} else if origReq.Indirect != req.Indirect {
wrongDirectness[req.Mod.Path] = origReq
}
delete(unused, req.Mod.Path)
}
for _, req := range unused {
srcErr, err := unusedError(pm.Mapper, req, snapshot.View().Options().ComputeEdits)
if err != nil {
return nil, err
}
errors = append(errors, srcErr)
}
for _, req := range wrongDirectness {
// Handle dependencies that are incorrectly labeled indirect and
// vice versa.
srcErr, err := directnessError(pm.Mapper, req, snapshot.View().Options().ComputeEdits)
if err != nil {
return nil, err
}
errors = append(errors, srcErr)
}
// Next, compute any diagnostics for modules that are missing from the
// go.mod file. The fixes will be for the go.mod file, but the
// diagnostics should also appear in both the go.mod file and the import
// statements in the Go files in which the dependencies are used.
missingModuleFixes := map[*modfile.Require][]source.SuggestedFix{}
for _, req := range missing {
srcErr, err := missingModuleError(snapshot, pm, req)
if err != nil {
return nil, err
}
missingModuleFixes[req] = srcErr.SuggestedFixes
errors = append(errors, srcErr)
}
// Add diagnostics for missing modules anywhere they are imported in the
// workspace.
for _, pkg := range workspacePkgs {
missingImports := map[string]*modfile.Require{}
for _, imp := range pkg.Imports() {
if req, ok := missing[imp.PkgPath()]; ok {
missingImports[imp.PkgPath()] = req
break
}
// If the import is a package of the dependency, then add the
// package to the map, this will eliminate the need to do this
// prefix package search on each import for each file.
// Example:
//
// import (
// "golang.org/x/tools/go/expect"
// "golang.org/x/tools/go/packages"
// )
// They both are related to the same module: "golang.org/x/tools".
var match string
for _, req := range ideal.Require {
if strings.HasPrefix(imp.PkgPath(), req.Mod.Path) && len(req.Mod.Path) > len(match) {
match = req.Mod.Path
}
}
if req, ok := missing[match]; ok {
missingImports[imp.PkgPath()] = req
}
}
// None of this package's imports are from missing modules.
if len(missingImports) == 0 {
continue
}
for _, pgf := range pkg.CompiledGoFiles() {
file, m := pgf.File, pgf.Mapper
if file == nil || m == nil {
continue
}
imports := make(map[string]*ast.ImportSpec)
for _, imp := range file.Imports {
if imp.Path == nil {
continue
}
if target, err := strconv.Unquote(imp.Path.Value); err == nil {
imports[target] = imp
}
}
if len(imports) == 0 {
continue
}
for importPath, req := range missingImports {
imp, ok := imports[importPath]
if !ok {
continue
}
fixes, ok := missingModuleFixes[req]
if !ok {
return nil, fmt.Errorf("no missing module fix for %q (%q)", importPath, req.Mod.Path)
}
srcErr, err := missingModuleForImport(snapshot, m, imp, req, fixes)
if err != nil {
return nil, err
}
errors = append(errors, srcErr)
}
}
}
return errors, nil
}
// unusedError returns a source.Error for an unused require.
func unusedError(m *protocol.ColumnMapper, req *modfile.Require, computeEdits diff.ComputeEdits) (source.Error, error) {
rng, err := rangeFromPositions(m, req.Syntax.Start, req.Syntax.End)
if err != nil {
return source.Error{}, err
}
args, err := source.MarshalArgs(m.URI, []string{req.Mod.Path + "@none"})
if err != nil {
return source.Error{}, err
}
return source.Error{
Category: source.GoModTidy,
Message: fmt.Sprintf("%s is not used in this module", req.Mod.Path),
Range: rng,
URI: m.URI,
SuggestedFixes: []source.SuggestedFix{{
Title: fmt.Sprintf("Remove dependency: %s", req.Mod.Path),
Command: &protocol.Command{
Title: source.CommandRemoveDependency.Title,
Command: source.CommandRemoveDependency.ID(),
Arguments: args,
},
}},
}, nil
}
// directnessError extracts errors when a dependency is labeled indirect when
// it should be direct and vice versa.
func directnessError(m *protocol.ColumnMapper, req *modfile.Require, computeEdits diff.ComputeEdits) (source.Error, error) {
rng, err := rangeFromPositions(m, req.Syntax.Start, req.Syntax.End)
if err != nil {
return source.Error{}, err
}
direction := "indirect"
if req.Indirect {
direction = "direct"
// If the dependency should be direct, just highlight the // indirect.
if comments := req.Syntax.Comment(); comments != nil && len(comments.Suffix) > 0 {
end := comments.Suffix[0].Start
end.LineRune += len(comments.Suffix[0].Token)
end.Byte += len([]byte(comments.Suffix[0].Token))
rng, err = rangeFromPositions(m, comments.Suffix[0].Start, end)
if err != nil {
return source.Error{}, err
}
}
}
// If the dependency should be indirect, add the // indirect.
edits, err := switchDirectness(req, m, computeEdits)
if err != nil {
return source.Error{}, err
}
return source.Error{
Message: fmt.Sprintf("%s should be %s", req.Mod.Path, direction),
Range: rng,
URI: m.URI,
Category: source.GoModTidy,
SuggestedFixes: []source.SuggestedFix{{
Title: fmt.Sprintf("Change %s to %s", req.Mod.Path, direction),
Edits: map[span.URI][]protocol.TextEdit{
m.URI: edits,
},
}},
}, nil
}
func missingModuleError(snapshot source.Snapshot, pm *source.ParsedModule, req *modfile.Require) (source.Error, error) {
start, end := pm.File.Module.Syntax.Span()
rng, err := rangeFromPositions(pm.Mapper, start, end)
if err != nil {
return source.Error{}, err
}
args, err := source.MarshalArgs(pm.Mapper.URI, []string{req.Mod.Path + "@" + req.Mod.Version})
if err != nil {
return source.Error{}, err
}
return source.Error{
URI: pm.Mapper.URI,
Range: rng,
Message: fmt.Sprintf("%s is not in your go.mod file", req.Mod.Path),
Category: source.GoModTidy,
Kind: source.ModTidyError,
SuggestedFixes: []source.SuggestedFix{{
Title: fmt.Sprintf("Add %s to your go.mod file", req.Mod.Path),
Command: &protocol.Command{
Title: source.CommandAddDependency.Title,
Command: source.CommandAddDependency.ID(),
Arguments: args,
},
}},
}, nil
}
// switchDirectness gets the edits needed to change an indirect dependency to
// direct and vice versa.
func switchDirectness(req *modfile.Require, m *protocol.ColumnMapper, computeEdits diff.ComputeEdits) ([]protocol.TextEdit, error) {
// We need a private copy of the parsed go.mod file, since we're going to
// modify it.
copied, err := modfile.Parse("", m.Content, nil)
if err != nil {
return nil, err
}
// Change the directness in the matching require statement. To avoid
// reordering the require statements, rewrite all of them.
var requires []*modfile.Require
for _, r := range copied.Require {
if r.Mod.Path == req.Mod.Path {
requires = append(requires, &modfile.Require{
Mod: r.Mod,
Syntax: r.Syntax,
Indirect: !r.Indirect,
})
continue
}
requires = append(requires, r)
}
copied.SetRequire(requires)
newContent, err := copied.Format()
if err != nil {
return nil, err
}
// Calculate the edits to be made due to the change.
diff := computeEdits(m.URI, string(m.Content), string(newContent))
return source.ToProtocolEdits(m, diff)
}
// missingModuleForImport creates an error for a given import path that comes
// from a missing module.
func missingModuleForImport(snapshot source.Snapshot, m *protocol.ColumnMapper, imp *ast.ImportSpec, req *modfile.Require, fixes []source.SuggestedFix) (source.Error, error) {
if req.Syntax == nil {
return source.Error{}, fmt.Errorf("no syntax for %v", req)
}
spn, err := span.NewRange(snapshot.FileSet(), imp.Path.Pos(), imp.Path.End()).Span()
if err != nil {
return source.Error{}, err
}
rng, err := m.Range(spn)
if err != nil {
return source.Error{}, err
}
return source.Error{
Category: source.GoModTidy,
URI: m.URI,
Range: rng,
Message: fmt.Sprintf("%s is not in your go.mod file", req.Mod.Path),
Kind: source.ModTidyError,
SuggestedFixes: fixes,
}, nil
}
func rangeFromPositions(m *protocol.ColumnMapper, s, e modfile.Position) (protocol.Range, error) {
toPoint := func(offset int) (span.Point, error) {
l, c, err := m.Converter.ToPosition(offset)
if err != nil {
return span.Point{}, err
}
return span.NewPoint(l, c, offset), nil
}
start, err := toPoint(s.Byte)
if err != nil {
return protocol.Range{}, err
}
end, err := toPoint(e.Byte)
if err != nil {
return protocol.Range{}, err
}
return m.Range(span.New(m.URI, start, end))
}