106 lines
2.3 KiB
Go
106 lines
2.3 KiB
Go
// Copyright 2013 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// Package gccgoimporter implements Import for gccgo-generated object files.
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package gccgoimporter
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import (
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"debug/elf"
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"fmt"
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"io"
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"os"
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"path/filepath"
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"strings"
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"code.google.com/p/go.tools/go/types"
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)
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// Locate the file from which to read export data.
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// This is intended to replicate the logic in gofrontend.
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func findExportFile(searchpaths []string, pkgpath string) (string, error) {
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for _, spath := range searchpaths {
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pkgfullpath := filepath.Join(spath, pkgpath)
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pkgdir, name := filepath.Split(pkgfullpath)
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for _, filepath := range [...]string{
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pkgfullpath,
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pkgfullpath + ".gox",
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pkgdir + "lib" + name + ".so",
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pkgdir + "lib" + name + ".a",
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pkgfullpath + ".o",
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} {
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fi, err := os.Stat(filepath)
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if err == nil && !fi.IsDir() {
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return filepath, nil
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}
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}
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}
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return "", fmt.Errorf("%s: could not find export data (tried %s)", pkgpath, strings.Join(searchpaths, ":"))
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}
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// Opens the export data file at the given path. If this is an ELF file,
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// searches for and opens the .go_export section.
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// This is intended to replicate the logic in gofrontend, although it doesn't handle archive files yet.
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func openExportFile(fpath string) (reader io.ReadSeeker, closer io.Closer, err error) {
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f, err := os.Open(fpath)
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if err != nil {
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return
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}
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closer = f
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var magic [4]byte
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_, err = f.ReadAt(magic[:], 0)
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if err != nil {
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f.Close()
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return
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}
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if string(magic[:]) == "v1;\n" {
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// Raw export data.
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reader = f
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return
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}
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ef, err := elf.NewFile(f)
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if err != nil {
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f.Close()
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return
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}
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sec := ef.Section(".go_export")
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if sec == nil {
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err = fmt.Errorf("%s: .go_export section not found", fpath)
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f.Close()
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return
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}
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reader = sec.Open()
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return
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}
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func GetImporter(searchpaths []string) types.Importer {
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return func(imports map[string]*types.Package, pkgpath string) (pkg *types.Package, err error) {
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if pkgpath == "unsafe" {
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return types.Unsafe, nil
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}
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fpath, err := findExportFile(searchpaths, pkgpath)
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if err != nil {
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return
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}
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reader, closer, err := openExportFile(fpath)
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if err != nil {
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return
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}
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defer closer.Close()
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var p parser
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p.init(fpath, reader, imports)
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pkg = p.parsePackage()
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return
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}
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}
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