+++ /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 (
- "fmt"
- "go/ast"
- "go/build"
- "go/parser"
- "go/token"
- pathpkg "path"
- "path/filepath"
- "strconv"
-
- "golang.org/x/tools/cmd/guru/serial"
- "golang.org/x/tools/go/buildutil"
- "golang.org/x/tools/go/loader"
-)
-
-// definition reports the location of the definition of an identifier.
-func definition(q *Query) error {
- // First try the simple resolution done by parser.
- // It only works for intra-file references but it is very fast.
- // (Extending this approach to all the files of the package,
- // resolved using ast.NewPackage, was not worth the effort.)
- {
- qpos, err := fastQueryPos(q.Build, q.Pos)
- if err != nil {
- return err
- }
-
- id, _ := qpos.path[0].(*ast.Ident)
- if id == nil {
- return fmt.Errorf("no identifier here")
- }
-
- // Did the parser resolve it to a local object?
- if obj := id.Obj; obj != nil && obj.Pos().IsValid() {
- q.Output(qpos.fset, &definitionResult{
- pos: obj.Pos(),
- descr: fmt.Sprintf("%s %s", obj.Kind, obj.Name),
- })
- return nil // success
- }
-
- // Qualified identifier?
- if pkg := packageForQualIdent(qpos.path, id); pkg != "" {
- srcdir := filepath.Dir(qpos.fset.File(qpos.start).Name())
- tok, pos, err := findPackageMember(q.Build, qpos.fset, srcdir, pkg, id.Name)
- if err != nil {
- return err
- }
- q.Output(qpos.fset, &definitionResult{
- pos: pos,
- descr: fmt.Sprintf("%s %s.%s", tok, pkg, id.Name),
- })
- return nil // success
- }
-
- // Fall back on the type checker.
- }
-
- // Run the type checker.
- lconf := loader.Config{Build: q.Build}
- allowErrors(&lconf)
-
- if _, err := importQueryPackage(q.Pos, &lconf); err != nil {
- return err
- }
-
- // Load/parse/type-check the program.
- 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")
- }
-
- // Look up the declaration of this identifier.
- // If id is an anonymous field declaration,
- // it is both a use of a type and a def of a field;
- // prefer the use in that case.
- obj := qpos.info.Uses[id]
- if obj == nil {
- obj = qpos.info.Defs[id]
- if obj == nil {
- // Happens for y in "switch y := x.(type)",
- // and the package declaration,
- // but I think that's all.
- return fmt.Errorf("no object for identifier")
- }
- }
-
- if !obj.Pos().IsValid() {
- return fmt.Errorf("%s is built in", obj.Name())
- }
-
- q.Output(lprog.Fset, &definitionResult{
- pos: obj.Pos(),
- descr: qpos.objectString(obj),
- })
- return nil
-}
-
-// packageForQualIdent returns the package p if id is X in a qualified
-// identifier p.X; it returns "" otherwise.
-//
-// Precondition: id is path[0], and the parser did not resolve id to a
-// local object. For speed, packageForQualIdent assumes that p is a
-// package iff it is the basename of an import path (and not, say, a
-// package-level decl in another file or a predeclared identifier).
-func packageForQualIdent(path []ast.Node, id *ast.Ident) string {
- if sel, ok := path[1].(*ast.SelectorExpr); ok && sel.Sel == id && ast.IsExported(id.Name) {
- if pkgid, ok := sel.X.(*ast.Ident); ok && pkgid.Obj == nil {
- f := path[len(path)-1].(*ast.File)
- for _, imp := range f.Imports {
- path, _ := strconv.Unquote(imp.Path.Value)
- if imp.Name != nil {
- if imp.Name.Name == pkgid.Name {
- return path // renaming import
- }
- } else if pathpkg.Base(path) == pkgid.Name {
- return path // ordinary import
- }
- }
- }
- }
- return ""
-}
-
-// findPackageMember returns the type and position of the declaration of
-// pkg.member by loading and parsing the files of that package.
-// srcdir is the directory in which the import appears.
-func findPackageMember(ctxt *build.Context, fset *token.FileSet, srcdir, pkg, member string) (token.Token, token.Pos, error) {
- bp, err := ctxt.Import(pkg, srcdir, 0)
- if err != nil {
- return 0, token.NoPos, err // no files for package
- }
-
- // TODO(adonovan): opt: parallelize.
- for _, fname := range bp.GoFiles {
- filename := filepath.Join(bp.Dir, fname)
-
- // Parse the file, opening it the file via the build.Context
- // so that we observe the effects of the -modified flag.
- f, _ := buildutil.ParseFile(fset, ctxt, nil, ".", filename, parser.Mode(0))
- if f == nil {
- continue
- }
-
- // Find a package-level decl called 'member'.
- for _, decl := range f.Decls {
- switch decl := decl.(type) {
- case *ast.GenDecl:
- for _, spec := range decl.Specs {
- switch spec := spec.(type) {
- case *ast.ValueSpec:
- // const or var
- for _, id := range spec.Names {
- if id.Name == member {
- return decl.Tok, id.Pos(), nil
- }
- }
- case *ast.TypeSpec:
- if spec.Name.Name == member {
- return token.TYPE, spec.Name.Pos(), nil
- }
- }
- }
- case *ast.FuncDecl:
- if decl.Recv == nil && decl.Name.Name == member {
- return token.FUNC, decl.Name.Pos(), nil
- }
- }
- }
- }
-
- return 0, token.NoPos, fmt.Errorf("couldn't find declaration of %s in %q", member, pkg)
-}
-
-type definitionResult struct {
- pos token.Pos // (nonzero) location of definition
- descr string // description of object it denotes
-}
-
-func (r *definitionResult) PrintPlain(printf printfFunc) {
- printf(r.pos, "defined here as %s", r.descr)
-}
-
-func (r *definitionResult) JSON(fset *token.FileSet) []byte {
- return toJSON(&serial.Definition{
- Desc: r.descr,
- ObjPos: fset.Position(r.pos).String(),
- })
-}
projects / dotfiles / .git / blobdiff