go/packages/golist_overlay.go - tools - Git at Google

 package packages

 import (
 	"bytes"
 	"encoding/json"
 	"go/parser"
 	"go/token"
 	"path"
 	"path/filepath"
 	"strconv"
 	"strings"
 	"sync"
 )

 // processGolistOverlay provides rudimentary support for adding
 // files that don't exist on disk to an overlay. The results can be
 // sometimes incorrect.
 // TODO(matloob): Handle unsupported cases, including the following:
 // - test files
 // - adding test and non-test files to test variants of packages
 // - determining the correct package to add given a new import path
 // - creating packages that don't exist
 func processGolistOverlay(cfg *Config, response *driverResponse) (modifiedPkgs, needPkgs []string, err error) {
 	havePkgs := make(map[string]string) // importPath -> non-test package ID
 	needPkgsSet := make(map[string]bool)
 	modifiedPkgsSet := make(map[string]bool)

 	for _, pkg := range response.Packages {
 		// This is an approximation of import path to id. This can be
 		// wrong for tests, vendored packages, and a number of other cases.
 		havePkgs[pkg.PkgPath] = pkg.ID
 	}

 	var rootDirs map[string]string
 	var onceGetRootDirs sync.Once

 	for opath, contents := range cfg.Overlay {
 		base := filepath.Base(opath)
 		if strings.HasSuffix(opath, "_test.go") {
 			// Overlays don't support adding new test files yet.
 			// TODO(matloob): support adding new test files.
 			continue
 		}
 		dir := filepath.Dir(opath)
 		var pkg *Package
 		var fileExists bool
 		for _, p := range response.Packages {
 			for _, f := range p.GoFiles {
 				if !sameFile(filepath.Dir(f), dir) {
 					continue
 				}
 				pkg = p
 				if filepath.Base(f) == base {
 					fileExists = true
 				}
 			}
 		}
 		// The overlay could have included an entirely new package.
 		if pkg == nil {
 			onceGetRootDirs.Do(func() {
 				rootDirs = determineRootDirs(cfg)
 			})
 			// Try to find the module or gopath dir the file is contained in.
 			// Then for modules, add the module opath to the beginning.
 			var pkgPath string
 			for rdir, rpath := range rootDirs {
 				// TODO(matloob): This doesn't properly handle symlinks.
 				r, err := filepath.Rel(rdir, dir)
 				if err != nil {
 					continue
 				}
 				pkgPath = filepath.ToSlash(r)
 				if rpath != "" {
 					pkgPath = path.Join(rpath, pkgPath)
 				}
 				// We only create one new package even it can belong in multiple modules or GOPATH entries.
 				// This is okay because tools (such as the LSP) that use overlays will recompute the overlay
 				// once the file is saved, and golist will do the right thing.
 				// TODO(matloob): Implement module tiebreaking?
 				break
 			}
 			if pkgPath == "" {
 				continue
 			}
 			pkgName, ok := extractPackageName(opath, contents)
 			if !ok {
 				continue
 			}
 			id := pkgPath
 			// Try to reclaim a package with the same id if it exists in the response.
 			for _, p := range response.Packages {
 				if reclaimPackage(p, id, opath, contents) {
 					pkg = p
 					break
 				}
 			}
 			// Otherwise, create a new package
 			if pkg == nil {
 				pkg = &Package{PkgPath: pkgPath, ID: id, Name: pkgName, Imports: make(map[string]*Package)}
 				// TODO(matloob): Is it okay to amend response.Packages this way?
 				response.Packages = append(response.Packages, pkg)
 				havePkgs[pkg.PkgPath] = id
 			}
 		}
 		if !fileExists {
 			pkg.GoFiles = append(pkg.GoFiles, opath)
 			// TODO(matloob): Adding the file to CompiledGoFiles can exhibit the wrong behavior
 			// if the file will be ignored due to its build tags.
 			pkg.CompiledGoFiles = append(pkg.CompiledGoFiles, opath)
 			modifiedPkgsSet[pkg.ID] = true
 		}
 		imports, err := extractImports(opath, contents)
 		if err != nil {
 			// Let the parser or type checker report errors later.
 			continue
 		}
 		for _, imp := range imports {
 			_, found := pkg.Imports[imp]
 			if !found {
 				// TODO(matloob): Handle cases when the following block isn't correct.
 				// These include imports of test variants, imports of vendored packages, etc.
 				id, ok := havePkgs[imp]
 				if !ok {
 					id = imp
 				}
 				pkg.Imports[imp] = &Package{ID: id}
 			}
 		}
 		continue
 	}

 	// toPkgPath tries to guess the package path given the id.
 	// This isn't always correct -- it's certainly wrong for
 	// vendored packages' paths.
 	toPkgPath := func(id string) string {
 		// TODO(matloob): Handle vendor paths.
 		i := strings.IndexByte(id, ' ')
 		if i >= 0 {
 			return id[:i]
 		}
 		return id
 	}

 	// Do another pass now that new packages have been created to determine the
 	// set of missing packages.
 	for _, pkg := range response.Packages {
 		for _, imp := range pkg.Imports {
 			pkgPath := toPkgPath(imp.ID)
 			if _, ok := havePkgs[pkgPath]; !ok {
 				needPkgsSet[pkgPath] = true
 			}
 		}
 	}

 	needPkgs = make([]string, 0, len(needPkgsSet))
 	for pkg := range needPkgsSet {
 		needPkgs = append(needPkgs, pkg)
 	}
 	modifiedPkgs = make([]string, 0, len(modifiedPkgsSet))
 	for pkg := range modifiedPkgsSet {
 		modifiedPkgs = append(modifiedPkgs, pkg)
 	}
 	return modifiedPkgs, needPkgs, err
 }

 // determineRootDirs returns a mapping from directories code can be contained in to the
 // corresponding import path prefixes of those directories.
 // Its result is used to try to determine the import path for a package containing
 // an overlay file.
 func determineRootDirs(cfg *Config) map[string]string {
 	// Assume modules first:
 	out, err := invokeGo(cfg, "list", "-m", "-json", "all")
 	if err != nil {
 		return determineRootDirsGOPATH(cfg)
 	}
 	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.
 		}
 		if mod.Dir != "" && mod.Path != "" {
 			// This is a valid module; add it to the map.
 			m[mod.Dir] = mod.Path
 		}
 	}
 	return m
 }

 func determineRootDirsGOPATH(cfg *Config) map[string]string {
 	m := map[string]string{}
 	out, err := invokeGo(cfg, "env", "GOPATH")
 	if err != nil {
 		// Could not determine root dir mapping. Everything is best-effort, so just return an empty map.
 		// When we try to find the import path for a directory, there will be no root-dir match and
 		// we'll give up.
 		return m
 	}
 	for _, p := range filepath.SplitList(string(bytes.TrimSpace(out.Bytes()))) {
 		m[filepath.Join(p, "src")] = ""
 	}
 	return m
 }

 func extractImports(filename string, contents []byte) ([]string, error) {
 	f, err := parser.ParseFile(token.NewFileSet(), filename, contents, parser.ImportsOnly) // TODO(matloob): reuse fileset?
 	if err != nil {
 		return nil, err
 	}
 	var res []string
 	for _, imp := range f.Imports {
 		quotedPath := imp.Path.Value
 		path, err := strconv.Unquote(quotedPath)
 		if err != nil {
 			return nil, err
 		}
 		res = append(res, path)
 	}
 	return res, nil
 }

 // reclaimPackage attempts to reuse a package that failed to load in an overlay.
 //
 // If the package has errors and has no Name, GoFiles, or Imports,
 // then it's possible that it doesn't yet exist on disk.
 func reclaimPackage(pkg *Package, id string, filename string, contents []byte) bool {
 	// TODO(rstambler): Check the message of the actual error?
 	// It differs between $GOPATH and module mode.
 	if pkg.ID != id {
 		return false
 	}
 	if len(pkg.Errors) != 1 {
 		return false
 	}
 	if pkg.Name != "" || pkg.ExportFile != "" {
 		return false
 	}
 	if len(pkg.GoFiles) > 0 || len(pkg.CompiledGoFiles) > 0 || len(pkg.OtherFiles) > 0 {
 		return false
 	}
 	if len(pkg.Imports) > 0 {
 		return false
 	}
 	pkgName, ok := extractPackageName(filename, contents)
 	if !ok {
 		return false
 	}
 	pkg.Name = pkgName
 	pkg.Errors = nil
 	return true
 }

 func extractPackageName(filename string, contents []byte) (string, bool) {
 	// TODO(rstambler): Check the message of the actual error?
 	// It differs between $GOPATH and module mode.
 	f, err := parser.ParseFile(token.NewFileSet(), filename, contents, parser.PackageClauseOnly) // TODO(matloob): reuse fileset?
 	if err != nil {
 		return "", false
 	}
 	return f.Name.Name, true
 }
	package packages

	import (
	"bytes"
	"encoding/json"
	"go/parser"
	"go/token"
	"path"
	"path/filepath"
	"strconv"
	"strings"
	"sync"
	)

	// processGolistOverlay provides rudimentary support for adding
	// files that don't exist on disk to an overlay. The results can be
	// sometimes incorrect.
	// TODO(matloob): Handle unsupported cases, including the following:
	// - test files
	// - adding test and non-test files to test variants of packages
	// - determining the correct package to add given a new import path
	// - creating packages that don't exist
	func processGolistOverlay(cfg Config, response driverResponse) (modifiedPkgs, needPkgs []string, err error) {
	havePkgs := make(map[string]string) // importPath -> non-test package ID
	needPkgsSet := make(map[string]bool)
	modifiedPkgsSet := make(map[string]bool)

	for _, pkg := range response.Packages {
	// This is an approximation of import path to id. This can be
	// wrong for tests, vendored packages, and a number of other cases.
	havePkgs[pkg.PkgPath] = pkg.ID
	}

	var rootDirs map[string]string
	var onceGetRootDirs sync.Once

	for opath, contents := range cfg.Overlay {
	base := filepath.Base(opath)
	if strings.HasSuffix(opath, "_test.go") {
	// Overlays don't support adding new test files yet.
	// TODO(matloob): support adding new test files.
	continue
	}
	dir := filepath.Dir(opath)
	var pkg *Package
	var fileExists bool
	for _, p := range response.Packages {
	for _, f := range p.GoFiles {
	if !sameFile(filepath.Dir(f), dir) {
	continue
	}
	pkg = p
	if filepath.Base(f) == base {
	fileExists = true
	}
	}
	}
	// The overlay could have included an entirely new package.
	if pkg == nil {
	onceGetRootDirs.Do(func() {
	rootDirs = determineRootDirs(cfg)
	})
	// Try to find the module or gopath dir the file is contained in.
	// Then for modules, add the module opath to the beginning.
	var pkgPath string
	for rdir, rpath := range rootDirs {
	// TODO(matloob): This doesn't properly handle symlinks.
	r, err := filepath.Rel(rdir, dir)
	if err != nil {
	continue
	}
	pkgPath = filepath.ToSlash(r)
	if rpath != "" {
	pkgPath = path.Join(rpath, pkgPath)
	}
	// We only create one new package even it can belong in multiple modules or GOPATH entries.
	// This is okay because tools (such as the LSP) that use overlays will recompute the overlay
	// once the file is saved, and golist will do the right thing.
	// TODO(matloob): Implement module tiebreaking?
	break
	}
	if pkgPath == "" {
	continue
	}
	pkgName, ok := extractPackageName(opath, contents)
	if !ok {
	continue
	}
	id := pkgPath
	// Try to reclaim a package with the same id if it exists in the response.
	for _, p := range response.Packages {
	if reclaimPackage(p, id, opath, contents) {
	pkg = p
	break
	}
	}
	// Otherwise, create a new package
	if pkg == nil {
	pkg = &Package{PkgPath: pkgPath, ID: id, Name: pkgName, Imports: make(map[string]*Package)}
	// TODO(matloob): Is it okay to amend response.Packages this way?
	response.Packages = append(response.Packages, pkg)
	havePkgs[pkg.PkgPath] = id
	}
	}
	if !fileExists {
	pkg.GoFiles = append(pkg.GoFiles, opath)
	// TODO(matloob): Adding the file to CompiledGoFiles can exhibit the wrong behavior
	// if the file will be ignored due to its build tags.
	pkg.CompiledGoFiles = append(pkg.CompiledGoFiles, opath)
	modifiedPkgsSet[pkg.ID] = true
	}
	imports, err := extractImports(opath, contents)
	if err != nil {
	// Let the parser or type checker report errors later.
	continue
	}
	for _, imp := range imports {
	_, found := pkg.Imports[imp]
	if !found {
	// TODO(matloob): Handle cases when the following block isn't correct.
	// These include imports of test variants, imports of vendored packages, etc.
	id, ok := havePkgs[imp]
	if !ok {
	id = imp
	}
	pkg.Imports[imp] = &Package{ID: id}
	}
	}
	continue
	}

	// toPkgPath tries to guess the package path given the id.
	// This isn't always correct -- it's certainly wrong for
	// vendored packages' paths.
	toPkgPath := func(id string) string {
	// TODO(matloob): Handle vendor paths.
	i := strings.IndexByte(id, ' ')
	if i >= 0 {
	return id[:i]
	}
	return id
	}

	// Do another pass now that new packages have been created to determine the
	// set of missing packages.
	for _, pkg := range response.Packages {
	for _, imp := range pkg.Imports {
	pkgPath := toPkgPath(imp.ID)
	if _, ok := havePkgs[pkgPath]; !ok {
	needPkgsSet[pkgPath] = true
	}
	}
	}

	needPkgs = make([]string, 0, len(needPkgsSet))
	for pkg := range needPkgsSet {
	needPkgs = append(needPkgs, pkg)
	}
	modifiedPkgs = make([]string, 0, len(modifiedPkgsSet))
	for pkg := range modifiedPkgsSet {
	modifiedPkgs = append(modifiedPkgs, pkg)
	}
	return modifiedPkgs, needPkgs, err
	}

	// determineRootDirs returns a mapping from directories code can be contained in to the
	// corresponding import path prefixes of those directories.
	// Its result is used to try to determine the import path for a package containing
	// an overlay file.
	func determineRootDirs(cfg *Config) map[string]string {
	// Assume modules first:
	out, err := invokeGo(cfg, "list", "-m", "-json", "all")
	if err != nil {
	return determineRootDirsGOPATH(cfg)
	}
	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.
	}
	if mod.Dir != "" && mod.Path != "" {
	// This is a valid module; add it to the map.
	m[mod.Dir] = mod.Path
	}
	}
	return m
	}

	func determineRootDirsGOPATH(cfg *Config) map[string]string {
	m := map[string]string{}
	out, err := invokeGo(cfg, "env", "GOPATH")
	if err != nil {
	// Could not determine root dir mapping. Everything is best-effort, so just return an empty map.
	// When we try to find the import path for a directory, there will be no root-dir match and
	// we'll give up.
	return m
	}
	for _, p := range filepath.SplitList(string(bytes.TrimSpace(out.Bytes()))) {
	m[filepath.Join(p, "src")] = ""
	}
	return m
	}

	func extractImports(filename string, contents []byte) ([]string, error) {
	f, err := parser.ParseFile(token.NewFileSet(), filename, contents, parser.ImportsOnly) // TODO(matloob): reuse fileset?
	if err != nil {
	return nil, err
	}
	var res []string
	for _, imp := range f.Imports {
	quotedPath := imp.Path.Value
	path, err := strconv.Unquote(quotedPath)
	if err != nil {
	return nil, err
	}
	res = append(res, path)
	}
	return res, nil
	}

	// reclaimPackage attempts to reuse a package that failed to load in an overlay.
	//
	// If the package has errors and has no Name, GoFiles, or Imports,
	// then it's possible that it doesn't yet exist on disk.
	func reclaimPackage(pkg *Package, id string, filename string, contents []byte) bool {
	// TODO(rstambler): Check the message of the actual error?
	// It differs between $GOPATH and module mode.
	if pkg.ID != id {
	return false
	}
	if len(pkg.Errors) != 1 {
	return false
	}
	if pkg.Name != "" \|\| pkg.ExportFile != "" {
	return false
	}
	if len(pkg.GoFiles) > 0 \|\| len(pkg.CompiledGoFiles) > 0 \|\| len(pkg.OtherFiles) > 0 {
	return false
	}
	if len(pkg.Imports) > 0 {
	return false
	}
	pkgName, ok := extractPackageName(filename, contents)
	if !ok {
	return false
	}
	pkg.Name = pkgName
	pkg.Errors = nil
	return true
	}

	func extractPackageName(filename string, contents []byte) (string, bool) {
	// TODO(rstambler): Check the message of the actual error?
	// It differs between $GOPATH and module mode.
	f, err := parser.ParseFile(token.NewFileSet(), filename, contents, parser.PackageClauseOnly) // TODO(matloob): reuse fileset?
	if err != nil {
	return "", false
	}
	return f.Name.Name, true
	}