+++ /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.
-
-// Except for this comment and the import path, this file is a verbatim copy of the file
-// with the same name in $GOROOT/src/go/internal/gccgoimporter.
-
-// Package gccgoimporter implements Import for gccgo-generated object files.
-package gccgoimporter // import "golang.org/x/tools/go/internal/gccgoimporter"
-
-import (
- "debug/elf"
- "fmt"
- "go/types"
- "io"
- "os"
- "path/filepath"
- "strings"
-)
-
-// A PackageInit describes an imported package that needs initialization.
-type PackageInit struct {
- Name string // short package name
- InitFunc string // name of init function
- Priority int // priority of init function, see InitData.Priority
-}
-
-// The gccgo-specific init data for a package.
-type InitData struct {
- // Initialization priority of this package relative to other packages.
- // This is based on the maximum depth of the package's dependency graph;
- // it is guaranteed to be greater than that of its dependencies.
- Priority int
-
- // The list of packages which this package depends on to be initialized,
- // including itself if needed. This is the subset of the transitive closure of
- // the package's dependencies that need initialization.
- Inits []PackageInit
-}
-
-// Locate the file from which to read export data.
-// This is intended to replicate the logic in gofrontend.
-func findExportFile(searchpaths []string, pkgpath string) (string, error) {
- for _, spath := range searchpaths {
- pkgfullpath := filepath.Join(spath, pkgpath)
- pkgdir, name := filepath.Split(pkgfullpath)
-
- for _, filepath := range [...]string{
- pkgfullpath,
- pkgfullpath + ".gox",
- pkgdir + "lib" + name + ".so",
- pkgdir + "lib" + name + ".a",
- pkgfullpath + ".o",
- } {
- fi, err := os.Stat(filepath)
- if err == nil && !fi.IsDir() {
- return filepath, nil
- }
- }
- }
-
- return "", fmt.Errorf("%s: could not find export data (tried %s)", pkgpath, strings.Join(searchpaths, ":"))
-}
-
-const (
- gccgov1Magic = "v1;\n"
- gccgov2Magic = "v2;\n"
- gccgov3Magic = "v3;\n"
- goimporterMagic = "\n$$ "
- archiveMagic = "!<ar"
-)
-
-// Opens the export data file at the given path. If this is an ELF file,
-// searches for and opens the .go_export section. If this is an archive,
-// reads the export data from the first member, which is assumed to be an ELF file.
-// This is intended to replicate the logic in gofrontend.
-func openExportFile(fpath string) (reader io.ReadSeeker, closer io.Closer, err error) {
- f, err := os.Open(fpath)
- if err != nil {
- return
- }
- closer = f
- defer func() {
- if err != nil && closer != nil {
- f.Close()
- }
- }()
-
- var magic [4]byte
- _, err = f.ReadAt(magic[:], 0)
- if err != nil {
- return
- }
-
- var elfreader io.ReaderAt
- switch string(magic[:]) {
- case gccgov1Magic, gccgov2Magic, gccgov3Magic, goimporterMagic:
- // Raw export data.
- reader = f
- return
-
- case archiveMagic:
- reader, err = arExportData(f)
- return
-
- default:
- elfreader = f
- }
-
- ef, err := elf.NewFile(elfreader)
- if err != nil {
- return
- }
-
- sec := ef.Section(".go_export")
- if sec == nil {
- err = fmt.Errorf("%s: .go_export section not found", fpath)
- return
- }
-
- reader = sec.Open()
- return
-}
-
-// An Importer resolves import paths to Packages. The imports map records
-// packages already known, indexed by package path.
-// An importer must determine the canonical package path and check imports
-// to see if it is already present in the map. If so, the Importer can return
-// the map entry. Otherwise, the importer must load the package data for the
-// given path into a new *Package, record it in imports map, and return the
-// package.
-type Importer func(imports map[string]*types.Package, path, srcDir string, lookup func(string) (io.ReadCloser, error)) (*types.Package, error)
-
-func GetImporter(searchpaths []string, initmap map[*types.Package]InitData) Importer {
- return func(imports map[string]*types.Package, pkgpath, srcDir string, lookup func(string) (io.ReadCloser, error)) (pkg *types.Package, err error) {
- // TODO(gri): Use srcDir.
- // Or not. It's possible that srcDir will fade in importance as
- // the go command and other tools provide a translation table
- // for relative imports (like ./foo or vendored imports).
- if pkgpath == "unsafe" {
- return types.Unsafe, nil
- }
-
- var reader io.ReadSeeker
- var fpath string
- var rc io.ReadCloser
- if lookup != nil {
- if p := imports[pkgpath]; p != nil && p.Complete() {
- return p, nil
- }
- rc, err = lookup(pkgpath)
- if err != nil {
- return nil, err
- }
- }
- if rc != nil {
- defer rc.Close()
- rs, ok := rc.(io.ReadSeeker)
- if !ok {
- return nil, fmt.Errorf("gccgo importer requires lookup to return an io.ReadSeeker, have %T", rc)
- }
- reader = rs
- fpath = "<lookup " + pkgpath + ">"
- // Take name from Name method (like on os.File) if present.
- if n, ok := rc.(interface{ Name() string }); ok {
- fpath = n.Name()
- }
- } else {
- fpath, err = findExportFile(searchpaths, pkgpath)
- if err != nil {
- return nil, err
- }
-
- r, closer, err := openExportFile(fpath)
- if err != nil {
- return nil, err
- }
- if closer != nil {
- defer closer.Close()
- }
- reader = r
- }
-
- var magics string
- magics, err = readMagic(reader)
- if err != nil {
- return
- }
-
- if magics == archiveMagic {
- reader, err = arExportData(reader)
- if err != nil {
- return
- }
- magics, err = readMagic(reader)
- if err != nil {
- return
- }
- }
-
- switch magics {
- case gccgov1Magic, gccgov2Magic, gccgov3Magic:
- var p parser
- p.init(fpath, reader, imports)
- pkg = p.parsePackage()
- if initmap != nil {
- initmap[pkg] = p.initdata
- }
-
- // Excluded for now: Standard gccgo doesn't support this import format currently.
- // case goimporterMagic:
- // var data []byte
- // data, err = ioutil.ReadAll(reader)
- // if err != nil {
- // return
- // }
- // var n int
- // n, pkg, err = importer.ImportData(imports, data)
- // if err != nil {
- // return
- // }
-
- // if initmap != nil {
- // suffixreader := bytes.NewReader(data[n:])
- // var p parser
- // p.init(fpath, suffixreader, nil)
- // p.parseInitData()
- // initmap[pkg] = p.initdata
- // }
-
- default:
- err = fmt.Errorf("unrecognized magic string: %q", magics)
- }
-
- return
- }
-}
-
-// readMagic reads the four bytes at the start of a ReadSeeker and
-// returns them as a string.
-func readMagic(reader io.ReadSeeker) (string, error) {
- var magic [4]byte
- if _, err := reader.Read(magic[:]); err != nil {
- return "", err
- }
- if _, err := reader.Seek(0, io.SeekStart); err != nil {
- return "", err
- }
- return string(magic[:]), nil
-}
projects / dotfiles / .git / blobdiff