--- /dev/null
+// Copyright 2013 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 main
+
+import (
+ "bytes"
+ "fmt"
+ "go/ast"
+ "go/build"
+ "go/parser"
+ "go/token"
+ "go/types"
+ "io"
+ "log"
+ "os"
+ "sort"
+ "strconv"
+ "strings"
+ "sync"
+
+ "golang.org/x/tools/cmd/guru/serial"
+ "golang.org/x/tools/go/buildutil"
+ "golang.org/x/tools/go/loader"
+ "golang.org/x/tools/imports"
+ "golang.org/x/tools/refactor/importgraph"
+)
+
+// The referrers function reports all identifiers that resolve to the same object
+// as the queried identifier, within any package in the workspace.
+func referrers(q *Query) error {
+ fset := token.NewFileSet()
+ lconf := loader.Config{Fset: fset, Build: q.Build}
+ allowErrors(&lconf)
+
+ if _, err := importQueryPackage(q.Pos, &lconf); err != nil {
+ return err
+ }
+
+ // Load tests of the query package
+ // even if the query location is not in the tests.
+ for path := range lconf.ImportPkgs {
+ lconf.ImportPkgs[path] = true
+ }
+
+ // Load/parse/type-check the query package.
+ lprog, err := lconf.Load()
+ if err != nil {
+ return err
+ }
+
+ qpos, err := parseQueryPos(lprog, q.Pos, false)
+ if err != nil {
+ return err
+ }
+
+ id, _ := qpos.path[0].(*ast.Ident)
+ if id == nil {
+ return fmt.Errorf("no identifier here")
+ }
+
+ obj := qpos.info.ObjectOf(id)
+ if obj == nil {
+ // Happens for y in "switch y := x.(type)",
+ // the package declaration,
+ // and unresolved identifiers.
+ if _, ok := qpos.path[1].(*ast.File); ok { // package decl?
+ return packageReferrers(q, qpos.info.Pkg.Path())
+ }
+ return fmt.Errorf("no object for identifier: %T", qpos.path[1])
+ }
+
+ // Imported package name?
+ if pkgname, ok := obj.(*types.PkgName); ok {
+ return packageReferrers(q, pkgname.Imported().Path())
+ }
+
+ if obj.Pkg() == nil {
+ return fmt.Errorf("references to predeclared %q are everywhere!", obj.Name())
+ }
+
+ q.Output(fset, &referrersInitialResult{
+ qinfo: qpos.info,
+ obj: obj,
+ })
+
+ // For a globally accessible object defined in package P, we
+ // must load packages that depend on P. Specifically, for a
+ // package-level object, we need load only direct importers
+ // of P, but for a field or method, we must load
+ // any package that transitively imports P.
+
+ if global, pkglevel := classify(obj); global {
+ if pkglevel {
+ return globalReferrersPkgLevel(q, obj, fset)
+ }
+ // We'll use the object's position to identify it in the larger program.
+ objposn := fset.Position(obj.Pos())
+ defpkg := obj.Pkg().Path() // defining package
+ return globalReferrers(q, qpos.info.Pkg.Path(), defpkg, objposn)
+ }
+
+ outputUses(q, fset, usesOf(obj, qpos.info), obj.Pkg())
+
+ return nil // success
+}
+
+// classify classifies objects by how far
+// we have to look to find references to them.
+func classify(obj types.Object) (global, pkglevel bool) {
+ if obj.Exported() {
+ if obj.Parent() == nil {
+ // selectable object (field or method)
+ return true, false
+ }
+ if obj.Parent() == obj.Pkg().Scope() {
+ // lexical object (package-level var/const/func/type)
+ return true, true
+ }
+ }
+ // object with unexported named or defined in local scope
+ return false, false
+}
+
+// packageReferrers reports all references to the specified package
+// throughout the workspace.
+func packageReferrers(q *Query, path string) error {
+ // Scan the workspace and build the import graph.
+ // Ignore broken packages.
+ _, rev, _ := importgraph.Build(q.Build)
+
+ // Find the set of packages that directly import the query package.
+ // Only those packages need typechecking of function bodies.
+ users := rev[path]
+
+ // Load the larger program.
+ fset := token.NewFileSet()
+ lconf := loader.Config{
+ Fset: fset,
+ Build: q.Build,
+ TypeCheckFuncBodies: func(p string) bool {
+ return users[strings.TrimSuffix(p, "_test")]
+ },
+ }
+ allowErrors(&lconf)
+
+ // The importgraph doesn't treat external test packages
+ // as separate nodes, so we must use ImportWithTests.
+ for path := range users {
+ lconf.ImportWithTests(path)
+ }
+
+ // Subtle! AfterTypeCheck needs no mutex for qpkg because the
+ // topological import order gives us the necessary happens-before edges.
+ // TODO(adonovan): what about import cycles?
+ var qpkg *types.Package
+
+ // For efficiency, we scan each package for references
+ // just after it has been type-checked. The loader calls
+ // AfterTypeCheck (concurrently), providing us with a stream of
+ // packages.
+ lconf.AfterTypeCheck = func(info *loader.PackageInfo, files []*ast.File) {
+ // AfterTypeCheck may be called twice for the same package due to augmentation.
+
+ if info.Pkg.Path() == path && qpkg == nil {
+ // Found the package of interest.
+ qpkg = info.Pkg
+ fakepkgname := types.NewPkgName(token.NoPos, qpkg, qpkg.Name(), qpkg)
+ q.Output(fset, &referrersInitialResult{
+ qinfo: info,
+ obj: fakepkgname, // bogus
+ })
+ }
+
+ // Only inspect packages that directly import the
+ // declaring package (and thus were type-checked).
+ if lconf.TypeCheckFuncBodies(info.Pkg.Path()) {
+ // Find PkgNames that refer to qpkg.
+ // TODO(adonovan): perhaps more useful would be to show imports
+ // of the package instead of qualified identifiers.
+ var refs []*ast.Ident
+ for id, obj := range info.Uses {
+ if obj, ok := obj.(*types.PkgName); ok && obj.Imported() == qpkg {
+ refs = append(refs, id)
+ }
+ }
+ outputUses(q, fset, refs, info.Pkg)
+ }
+
+ clearInfoFields(info) // save memory
+ }
+
+ lconf.Load() // ignore error
+
+ if qpkg == nil {
+ log.Fatalf("query package %q not found during reloading", path)
+ }
+
+ return nil
+}
+
+func usesOf(queryObj types.Object, info *loader.PackageInfo) []*ast.Ident {
+ var refs []*ast.Ident
+ for id, obj := range info.Uses {
+ if sameObj(queryObj, obj) {
+ refs = append(refs, id)
+ }
+ }
+ return refs
+}
+
+// outputUses outputs a result describing refs, which appear in the package denoted by info.
+func outputUses(q *Query, fset *token.FileSet, refs []*ast.Ident, pkg *types.Package) {
+ if len(refs) > 0 {
+ sort.Sort(byNamePos{fset, refs})
+ q.Output(fset, &referrersPackageResult{
+ pkg: pkg,
+ build: q.Build,
+ fset: fset,
+ refs: refs,
+ })
+ }
+}
+
+// globalReferrers reports references throughout the entire workspace to the
+// object (a field or method) at the specified source position.
+// Its defining package is defpkg, and the query package is qpkg.
+func globalReferrers(q *Query, qpkg, defpkg string, objposn token.Position) error {
+ // Scan the workspace and build the import graph.
+ // Ignore broken packages.
+ _, rev, _ := importgraph.Build(q.Build)
+
+ // Find the set of packages that depend on defpkg.
+ // Only function bodies in those packages need type-checking.
+ users := rev.Search(defpkg) // transitive importers
+
+ // Prepare to load the larger program.
+ fset := token.NewFileSet()
+ lconf := loader.Config{
+ Fset: fset,
+ Build: q.Build,
+ TypeCheckFuncBodies: func(p string) bool {
+ return users[strings.TrimSuffix(p, "_test")]
+ },
+ }
+ allowErrors(&lconf)
+
+ // The importgraph doesn't treat external test packages
+ // as separate nodes, so we must use ImportWithTests.
+ for path := range users {
+ lconf.ImportWithTests(path)
+ }
+
+ // The remainder of this function is somewhat tricky because it
+ // operates on the concurrent stream of packages observed by the
+ // loader's AfterTypeCheck hook. Most of guru's helper
+ // functions assume the entire program has already been loaded,
+ // so we can't use them here.
+ // TODO(adonovan): smooth things out once the other changes have landed.
+
+ // Results are reported concurrently from within the
+ // AfterTypeCheck hook. The program may provide a useful stream
+ // of information even if the user doesn't let the program run
+ // to completion.
+
+ var (
+ mu sync.Mutex
+ qobj types.Object
+ )
+
+ // For efficiency, we scan each package for references
+ // just after it has been type-checked. The loader calls
+ // AfterTypeCheck (concurrently), providing us with a stream of
+ // packages.
+ lconf.AfterTypeCheck = func(info *loader.PackageInfo, files []*ast.File) {
+ // AfterTypeCheck may be called twice for the same package due to augmentation.
+
+ // Only inspect packages that depend on the declaring package
+ // (and thus were type-checked).
+ if lconf.TypeCheckFuncBodies(info.Pkg.Path()) {
+ // Record the query object and its package when we see it.
+ mu.Lock()
+ if qobj == nil && info.Pkg.Path() == defpkg {
+ // Find the object by its position (slightly ugly).
+ qobj = findObject(fset, &info.Info, objposn)
+ if qobj == nil {
+ // It really ought to be there;
+ // we found it once already.
+ log.Fatalf("object at %s not found in package %s",
+ objposn, defpkg)
+ }
+ }
+ obj := qobj
+ mu.Unlock()
+
+ // Look for references to the query object.
+ if obj != nil {
+ outputUses(q, fset, usesOf(obj, info), info.Pkg)
+ }
+ }
+
+ clearInfoFields(info) // save memory
+ }
+
+ lconf.Load() // ignore error
+
+ if qobj == nil {
+ log.Fatal("query object not found during reloading")
+ }
+
+ return nil // success
+}
+
+// globalReferrersPkgLevel reports references throughout the entire workspace to the package-level object obj.
+// It assumes that the query object itself has already been reported.
+func globalReferrersPkgLevel(q *Query, obj types.Object, fset *token.FileSet) error {
+ // globalReferrersPkgLevel uses go/ast and friends instead of go/types.
+ // This affords a considerable performance benefit.
+ // It comes at the cost of some code complexity.
+ //
+ // Here's a high level summary.
+ //
+ // The goal is to find references to the query object p.Q.
+ // There are several possible scenarios, each handled differently.
+ //
+ // 1. We are looking in a package other than p, and p is not dot-imported.
+ // This is the simplest case. Q must be referred to as n.Q,
+ // where n is the name under which p is imported.
+ // We look at all imports of p to gather all names under which it is imported.
+ // (In the typical case, it is imported only once, under its default name.)
+ // Then we look at all selector expressions and report any matches.
+ //
+ // 2. We are looking in a package other than p, and p is dot-imported.
+ // In this case, Q will be referred to just as Q.
+ // Furthermore, go/ast's object resolution will not be able to resolve
+ // Q to any other object, unlike any local (file- or function- or block-scoped) object.
+ // So we look at all matching identifiers and report all unresolvable ones.
+ //
+ // 3. We are looking in package p.
+ // (Care must be taken to separate p and p_test (an xtest package),
+ // and make sure that they are treated as separate packages.)
+ // In this case, we give go/ast the entire package for object resolution,
+ // instead of going file by file.
+ // We then iterate over all identifiers that resolve to the query object.
+ // (The query object itself has already been reported, so we don't re-report it.)
+ //
+ // We always skip all files that don't contain the string Q, as they cannot be
+ // relevant to finding references to Q.
+ //
+ // We parse all files leniently. In the presence of parsing errors, results are best-effort.
+
+ // Scan the workspace and build the import graph.
+ // Ignore broken packages.
+ _, rev, _ := importgraph.Build(q.Build)
+
+ // Find the set of packages that directly import defpkg.
+ defpkg := obj.Pkg().Path()
+ defpkg = strings.TrimSuffix(defpkg, "_test") // package x_test actually has package name x
+ defpkg = imports.VendorlessPath(defpkg) // remove vendor goop
+
+ users := rev[defpkg]
+ if len(users) == 0 {
+ users = make(map[string]bool)
+ }
+ // We also need to check defpkg itself, and its xtests.
+ // For the reverse graph packages, we process xtests with the main package.
+ // defpkg gets special handling; we must distinguish between in-package vs out-of-package.
+ // To make the control flow below simpler, add defpkg and defpkg xtest placeholders.
+ // Use "!test" instead of "_test" because "!" is not a valid character in an import path.
+ // (More precisely, it is not guaranteed to be a valid character in an import path,
+ // so it is unlikely that it will be in use. See https://golang.org/ref/spec#Import_declarations.)
+ users[defpkg] = true
+ users[defpkg+"!test"] = true
+
+ cwd, err := os.Getwd()
+ if err != nil {
+ return err
+ }
+
+ defname := obj.Pkg().Name() // name of defining package, used for imports using import path only
+ isxtest := strings.HasSuffix(defname, "_test") // indicates whether the query object is defined in an xtest package
+
+ name := obj.Name()
+ namebytes := []byte(name) // byte slice version of query object name, for early filtering
+ objpos := fset.Position(obj.Pos()) // position of query object, used to prevent re-emitting original decl
+
+ sema := make(chan struct{}, 20) // counting semaphore to limit I/O concurrency
+ var wg sync.WaitGroup
+
+ for u := range users {
+ u := u
+ wg.Add(1)
+ go func() {
+ defer wg.Done()
+
+ uIsXTest := strings.HasSuffix(u, "!test") // indicates whether this package is the special defpkg xtest package
+ u = strings.TrimSuffix(u, "!test")
+
+ // Resolve package.
+ sema <- struct{}{} // acquire token
+ pkg, err := q.Build.Import(u, cwd, build.IgnoreVendor)
+ <-sema // release token
+ if err != nil {
+ return
+ }
+
+ // If we're not in the query package,
+ // the object is in another package regardless,
+ // so we want to process all files.
+ // If we are in the query package,
+ // we want to only process the files that are
+ // part of that query package;
+ // that set depends on whether the query package itself is an xtest.
+ inQueryPkg := u == defpkg && isxtest == uIsXTest
+ var files []string
+ if !inQueryPkg || !isxtest {
+ files = append(files, pkg.GoFiles...)
+ files = append(files, pkg.TestGoFiles...)
+ files = append(files, pkg.CgoFiles...) // use raw cgo files, as we're only parsing
+ }
+ if !inQueryPkg || isxtest {
+ files = append(files, pkg.XTestGoFiles...)
+ }
+
+ if len(files) == 0 {
+ return
+ }
+
+ var deffiles map[string]*ast.File
+ if inQueryPkg {
+ deffiles = make(map[string]*ast.File)
+ }
+
+ buf := new(bytes.Buffer) // reusable buffer for reading files
+
+ for _, file := range files {
+ if !buildutil.IsAbsPath(q.Build, file) {
+ file = buildutil.JoinPath(q.Build, pkg.Dir, file)
+ }
+ buf.Reset()
+ sema <- struct{}{} // acquire token
+ src, err := readFile(q.Build, file, buf)
+ <-sema // release token
+ if err != nil {
+ continue
+ }
+
+ // Fast path: If the object's name isn't present anywhere in the source, ignore the file.
+ if !bytes.Contains(src, namebytes) {
+ continue
+ }
+
+ if inQueryPkg {
+ // If we're in the query package, we defer final processing until we have
+ // parsed all of the candidate files in the package.
+ // Best effort; allow errors and use what we can from what remains.
+ f, _ := parser.ParseFile(fset, file, src, parser.AllErrors)
+ if f != nil {
+ deffiles[file] = f
+ }
+ continue
+ }
+
+ // We aren't in the query package. Go file by file.
+
+ // Parse out only the imports, to check whether the defining package
+ // was imported, and if so, under what names.
+ // Best effort; allow errors and use what we can from what remains.
+ f, _ := parser.ParseFile(fset, file, src, parser.ImportsOnly|parser.AllErrors)
+ if f == nil {
+ continue
+ }
+
+ // pkgnames is the set of names by which defpkg is imported in this file.
+ // (Multiple imports in the same file are legal but vanishingly rare.)
+ pkgnames := make([]string, 0, 1)
+ var isdotimport bool
+ for _, imp := range f.Imports {
+ path, err := strconv.Unquote(imp.Path.Value)
+ if err != nil || path != defpkg {
+ continue
+ }
+ switch {
+ case imp.Name == nil:
+ pkgnames = append(pkgnames, defname)
+ case imp.Name.Name == ".":
+ isdotimport = true
+ default:
+ pkgnames = append(pkgnames, imp.Name.Name)
+ }
+ }
+ if len(pkgnames) == 0 && !isdotimport {
+ // Defining package not imported, bail.
+ continue
+ }
+
+ // Re-parse the entire file.
+ // Parse errors are ok; we'll do the best we can with a partial AST, if we have one.
+ f, _ = parser.ParseFile(fset, file, src, parser.AllErrors)
+ if f == nil {
+ continue
+ }
+
+ // Walk the AST looking for references.
+ var refs []*ast.Ident
+ ast.Inspect(f, func(n ast.Node) bool {
+ // Check selector expressions.
+ // If the selector matches the target name,
+ // and the expression is one of the names
+ // that the defining package was imported under,
+ // then we have a match.
+ if sel, ok := n.(*ast.SelectorExpr); ok && sel.Sel.Name == name {
+ if id, ok := sel.X.(*ast.Ident); ok {
+ for _, n := range pkgnames {
+ if n == id.Name {
+ refs = append(refs, sel.Sel)
+ // Don't recurse further, to avoid duplicate entries
+ // from the dot import check below.
+ return false
+ }
+ }
+ }
+ }
+ // Dot imports are special.
+ // Objects imported from the defining package are placed in the package scope.
+ // go/ast does not resolve them to an object.
+ // At all other scopes (file, local), go/ast can do the resolution.
+ // So we're looking for object-free idents with the right name.
+ // The only other way to get something with the right name at the package scope
+ // is to *be* the defining package. We handle that case separately (inQueryPkg).
+ if isdotimport {
+ if id, ok := n.(*ast.Ident); ok && id.Obj == nil && id.Name == name {
+ refs = append(refs, id)
+ return false
+ }
+ }
+ return true
+ })
+
+ // Emit any references we found.
+ if len(refs) > 0 {
+ q.Output(fset, &referrersPackageResult{
+ pkg: types.NewPackage(pkg.ImportPath, pkg.Name),
+ build: q.Build,
+ fset: fset,
+ refs: refs,
+ })
+ }
+ }
+
+ // If we're in the query package, we've now collected all the files in the package.
+ // (Or at least the ones that might contain references to the object.)
+ // Find and emit refs.
+ if inQueryPkg {
+ // Bundle the files together into a package.
+ // This does package-level object resolution.
+ qpkg, _ := ast.NewPackage(fset, deffiles, nil, nil)
+ // Look up the query object; we know that it is defined in the package scope.
+ pkgobj := qpkg.Scope.Objects[name]
+ if pkgobj == nil {
+ panic("missing defpkg object for " + defpkg + "." + name)
+ }
+ // Find all references to the query object.
+ var refs []*ast.Ident
+ ast.Inspect(qpkg, func(n ast.Node) bool {
+ if id, ok := n.(*ast.Ident); ok {
+ // Check both that this is a reference to the query object
+ // and that it is not the query object itself;
+ // the query object itself was already emitted.
+ if id.Obj == pkgobj && objpos != fset.Position(id.Pos()) {
+ refs = append(refs, id)
+ return false
+ }
+ }
+ return true
+ })
+ if len(refs) > 0 {
+ q.Output(fset, &referrersPackageResult{
+ pkg: types.NewPackage(pkg.ImportPath, pkg.Name),
+ build: q.Build,
+ fset: fset,
+ refs: refs,
+ })
+ }
+ deffiles = nil // allow GC
+ }
+ }()
+ }
+
+ wg.Wait()
+
+ return nil
+}
+
+// findObject returns the object defined at the specified position.
+func findObject(fset *token.FileSet, info *types.Info, objposn token.Position) types.Object {
+ good := func(obj types.Object) bool {
+ if obj == nil {
+ return false
+ }
+ posn := fset.Position(obj.Pos())
+ return posn.Filename == objposn.Filename && posn.Offset == objposn.Offset
+ }
+ for _, obj := range info.Defs {
+ if good(obj) {
+ return obj
+ }
+ }
+ for _, obj := range info.Implicits {
+ if good(obj) {
+ return obj
+ }
+ }
+ return nil
+}
+
+// same reports whether x and y are identical, or both are PkgNames
+// that import the same Package.
+//
+func sameObj(x, y types.Object) bool {
+ if x == y {
+ return true
+ }
+ if x, ok := x.(*types.PkgName); ok {
+ if y, ok := y.(*types.PkgName); ok {
+ return x.Imported() == y.Imported()
+ }
+ }
+ return false
+}
+
+func clearInfoFields(info *loader.PackageInfo) {
+ // TODO(adonovan): opt: save memory by eliminating unneeded scopes/objects.
+ // (Requires go/types change for Go 1.7.)
+ // info.Pkg.Scope().ClearChildren()
+
+ // Discard the file ASTs and their accumulated type
+ // information to save memory.
+ info.Files = nil
+ info.Defs = make(map[*ast.Ident]types.Object)
+ info.Uses = make(map[*ast.Ident]types.Object)
+ info.Implicits = make(map[ast.Node]types.Object)
+
+ // Also, disable future collection of wholly unneeded
+ // type information for the package in case there is
+ // more type-checking to do (augmentation).
+ info.Types = nil
+ info.Scopes = nil
+ info.Selections = nil
+}
+
+// -------- utils --------
+
+// An deterministic ordering for token.Pos that doesn't
+// depend on the order in which packages were loaded.
+func lessPos(fset *token.FileSet, x, y token.Pos) bool {
+ fx := fset.File(x)
+ fy := fset.File(y)
+ if fx != fy {
+ return fx.Name() < fy.Name()
+ }
+ return x < y
+}
+
+type byNamePos struct {
+ fset *token.FileSet
+ ids []*ast.Ident
+}
+
+func (p byNamePos) Len() int { return len(p.ids) }
+func (p byNamePos) Swap(i, j int) { p.ids[i], p.ids[j] = p.ids[j], p.ids[i] }
+func (p byNamePos) Less(i, j int) bool {
+ return lessPos(p.fset, p.ids[i].NamePos, p.ids[j].NamePos)
+}
+
+// referrersInitialResult is the initial result of a "referrers" query.
+type referrersInitialResult struct {
+ qinfo *loader.PackageInfo
+ obj types.Object // object it denotes
+}
+
+func (r *referrersInitialResult) PrintPlain(printf printfFunc) {
+ printf(r.obj, "references to %s",
+ types.ObjectString(r.obj, types.RelativeTo(r.qinfo.Pkg)))
+}
+
+func (r *referrersInitialResult) JSON(fset *token.FileSet) []byte {
+ var objpos string
+ if pos := r.obj.Pos(); pos.IsValid() {
+ objpos = fset.Position(pos).String()
+ }
+ return toJSON(&serial.ReferrersInitial{
+ Desc: r.obj.String(),
+ ObjPos: objpos,
+ })
+}
+
+// referrersPackageResult is the streaming result for one package of a "referrers" query.
+type referrersPackageResult struct {
+ pkg *types.Package
+ build *build.Context
+ fset *token.FileSet
+ refs []*ast.Ident // set of all other references to it
+}
+
+// forEachRef calls f(id, text) for id in r.refs, in order.
+// Text is the text of the line on which id appears.
+func (r *referrersPackageResult) foreachRef(f func(id *ast.Ident, text string)) {
+ // Show referring lines, like grep.
+ type fileinfo struct {
+ refs []*ast.Ident
+ linenums []int // line number of refs[i]
+ data chan interface{} // file contents or error
+ }
+ var fileinfos []*fileinfo
+ fileinfosByName := make(map[string]*fileinfo)
+
+ // First pass: start the file reads concurrently.
+ sema := make(chan struct{}, 20) // counting semaphore to limit I/O concurrency
+ for _, ref := range r.refs {
+ posn := r.fset.Position(ref.Pos())
+ fi := fileinfosByName[posn.Filename]
+ if fi == nil {
+ fi = &fileinfo{data: make(chan interface{})}
+ fileinfosByName[posn.Filename] = fi
+ fileinfos = append(fileinfos, fi)
+
+ // First request for this file:
+ // start asynchronous read.
+ go func() {
+ sema <- struct{}{} // acquire token
+ content, err := readFile(r.build, posn.Filename, nil)
+ <-sema // release token
+ if err != nil {
+ fi.data <- err
+ } else {
+ fi.data <- content
+ }
+ }()
+ }
+ fi.refs = append(fi.refs, ref)
+ fi.linenums = append(fi.linenums, posn.Line)
+ }
+
+ // Second pass: print refs in original order.
+ // One line may have several refs at different columns.
+ for _, fi := range fileinfos {
+ v := <-fi.data // wait for I/O completion
+
+ // Print one item for all refs in a file that could not
+ // be loaded (perhaps due to //line directives).
+ if err, ok := v.(error); ok {
+ var suffix string
+ if more := len(fi.refs) - 1; more > 0 {
+ suffix = fmt.Sprintf(" (+ %d more refs in this file)", more)
+ }
+ f(fi.refs[0], err.Error()+suffix)
+ continue
+ }
+
+ lines := bytes.Split(v.([]byte), []byte("\n"))
+ for i, ref := range fi.refs {
+ f(ref, string(lines[fi.linenums[i]-1]))
+ }
+ }
+}
+
+// readFile is like ioutil.ReadFile, but
+// it goes through the virtualized build.Context.
+// If non-nil, buf must have been reset.
+func readFile(ctxt *build.Context, filename string, buf *bytes.Buffer) ([]byte, error) {
+ rc, err := buildutil.OpenFile(ctxt, filename)
+ if err != nil {
+ return nil, err
+ }
+ defer rc.Close()
+ if buf == nil {
+ buf = new(bytes.Buffer)
+ }
+ if _, err := io.Copy(buf, rc); err != nil {
+ return nil, err
+ }
+ return buf.Bytes(), nil
+}
+
+func (r *referrersPackageResult) PrintPlain(printf printfFunc) {
+ r.foreachRef(func(id *ast.Ident, text string) {
+ printf(id, "%s", text)
+ })
+}
+
+func (r *referrersPackageResult) JSON(fset *token.FileSet) []byte {
+ refs := serial.ReferrersPackage{Package: r.pkg.Path()}
+ r.foreachRef(func(id *ast.Ident, text string) {
+ refs.Refs = append(refs.Refs, serial.Ref{
+ Pos: fset.Position(id.NamePos).String(),
+ Text: text,
+ })
+ })
+ return toJSON(refs)
+}