Imported Upstream version 1.4upstream/1.4

1 files changed, 394 insertions, 0 deletions

diff --git a/src/debug/pe/file.go b/src/debug/pe/file.go
new file mode 100644
index 000000000..759e5674f
--- /dev/null
+++ b/src/debug/pe/file.go
@@ -0,0 +1,394 @@
+// Copyright 2009 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 pe implements access to PE (Microsoft Windows Portable Executable) files.
+package pe
+
+import (
+	"debug/dwarf"
+	"encoding/binary"
+	"errors"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+)
+
+// A File represents an open PE file.
+type File struct {
+	FileHeader
+	OptionalHeader interface{} // of type *OptionalHeader32 or *OptionalHeader64
+	Sections       []*Section
+	Symbols        []*Symbol
+
+	closer io.Closer
+}
+
+type SectionHeader struct {
+	Name                 string
+	VirtualSize          uint32
+	VirtualAddress       uint32
+	Size                 uint32
+	Offset               uint32
+	PointerToRelocations uint32
+	PointerToLineNumbers uint32
+	NumberOfRelocations  uint16
+	NumberOfLineNumbers  uint16
+	Characteristics      uint32
+}
+
+type Section struct {
+	SectionHeader
+
+	// Embed ReaderAt for ReadAt method.
+	// Do not embed SectionReader directly
+	// to avoid having Read and Seek.
+	// If a client wants Read and Seek it must use
+	// Open() to avoid fighting over the seek offset
+	// with other clients.
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+type Symbol struct {
+	Name          string
+	Value         uint32
+	SectionNumber int16
+	Type          uint16
+	StorageClass  uint8
+}
+
+type ImportDirectory struct {
+	OriginalFirstThunk uint32
+	TimeDateStamp      uint32
+	ForwarderChain     uint32
+	Name               uint32
+	FirstThunk         uint32
+
+	dll string
+}
+
+// Data reads and returns the contents of the PE section.
+func (s *Section) Data() ([]byte, error) {
+	dat := make([]byte, s.sr.Size())
+	n, err := s.sr.ReadAt(dat, 0)
+	if n == len(dat) {
+		err = nil
+	}
+	return dat[0:n], err
+}
+
+// Open returns a new ReadSeeker reading the PE section.
+func (s *Section) Open() io.ReadSeeker { return io.NewSectionReader(s.sr, 0, 1<<63-1) }
+
+type FormatError struct {
+	off int64
+	msg string
+	val interface{}
+}
+
+func (e *FormatError) Error() string {
+	msg := e.msg
+	if e.val != nil {
+		msg += fmt.Sprintf(" '%v'", e.val)
+	}
+	msg += fmt.Sprintf(" in record at byte %#x", e.off)
+	return msg
+}
+
+// Open opens the named file using os.Open and prepares it for use as a PE binary.
+func Open(name string) (*File, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	ff, err := NewFile(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	ff.closer = f
+	return ff, nil
+}
+
+// Close closes the File.
+// If the File was created using NewFile directly instead of Open,
+// Close has no effect.
+func (f *File) Close() error {
+	var err error
+	if f.closer != nil {
+		err = f.closer.Close()
+		f.closer = nil
+	}
+	return err
+}
+
+var (
+	sizeofOptionalHeader32 = uint16(binary.Size(OptionalHeader32{}))
+	sizeofOptionalHeader64 = uint16(binary.Size(OptionalHeader64{}))
+)
+
+// NewFile creates a new File for accessing a PE binary in an underlying reader.
+func NewFile(r io.ReaderAt) (*File, error) {
+	f := new(File)
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+
+	var dosheader [96]byte
+	if _, err := r.ReadAt(dosheader[0:], 0); err != nil {
+		return nil, err
+	}
+	var base int64
+	if dosheader[0] == 'M' && dosheader[1] == 'Z' {
+		signoff := int64(binary.LittleEndian.Uint32(dosheader[0x3c:]))
+		var sign [4]byte
+		r.ReadAt(sign[:], signoff)
+		if !(sign[0] == 'P' && sign[1] == 'E' && sign[2] == 0 && sign[3] == 0) {
+			return nil, errors.New("Invalid PE File Format.")
+		}
+		base = signoff + 4
+	} else {
+		base = int64(0)
+	}
+	sr.Seek(base, os.SEEK_SET)
+	if err := binary.Read(sr, binary.LittleEndian, &f.FileHeader); err != nil {
+		return nil, err
+	}
+	if f.FileHeader.Machine != IMAGE_FILE_MACHINE_UNKNOWN && f.FileHeader.Machine != IMAGE_FILE_MACHINE_AMD64 && f.FileHeader.Machine != IMAGE_FILE_MACHINE_I386 {
+		return nil, errors.New("Invalid PE File Format.")
+	}
+
+	var ss []byte
+	if f.FileHeader.NumberOfSymbols > 0 {
+		// Get COFF string table, which is located at the end of the COFF symbol table.
+		sr.Seek(int64(f.FileHeader.PointerToSymbolTable+COFFSymbolSize*f.FileHeader.NumberOfSymbols), os.SEEK_SET)
+		var l uint32
+		if err := binary.Read(sr, binary.LittleEndian, &l); err != nil {
+			return nil, err
+		}
+		ss = make([]byte, l)
+		if _, err := r.ReadAt(ss, int64(f.FileHeader.PointerToSymbolTable+COFFSymbolSize*f.FileHeader.NumberOfSymbols)); err != nil {
+			return nil, err
+		}
+
+		// Process COFF symbol table.
+		sr.Seek(int64(f.FileHeader.PointerToSymbolTable), os.SEEK_SET)
+		aux := uint8(0)
+		for i := 0; i < int(f.FileHeader.NumberOfSymbols); i++ {
+			cs := new(COFFSymbol)
+			if err := binary.Read(sr, binary.LittleEndian, cs); err != nil {
+				return nil, err
+			}
+			if aux > 0 {
+				aux--
+				continue
+			}
+			var name string
+			if cs.Name[0] == 0 && cs.Name[1] == 0 && cs.Name[2] == 0 && cs.Name[3] == 0 {
+				si := int(binary.LittleEndian.Uint32(cs.Name[4:]))
+				name, _ = getString(ss, si)
+			} else {
+				name = cstring(cs.Name[:])
+			}
+			aux = cs.NumberOfAuxSymbols
+			s := &Symbol{
+				Name:          name,
+				Value:         cs.Value,
+				SectionNumber: cs.SectionNumber,
+				Type:          cs.Type,
+				StorageClass:  cs.StorageClass,
+			}
+			f.Symbols = append(f.Symbols, s)
+		}
+	}
+
+	// Read optional header.
+	sr.Seek(base, os.SEEK_SET)
+	if err := binary.Read(sr, binary.LittleEndian, &f.FileHeader); err != nil {
+		return nil, err
+	}
+	var oh32 OptionalHeader32
+	var oh64 OptionalHeader64
+	switch f.FileHeader.SizeOfOptionalHeader {
+	case sizeofOptionalHeader32:
+		if err := binary.Read(sr, binary.LittleEndian, &oh32); err != nil {
+			return nil, err
+		}
+		if oh32.Magic != 0x10b { // PE32
+			return nil, fmt.Errorf("pe32 optional header has unexpected Magic of 0x%x", oh32.Magic)
+		}
+		f.OptionalHeader = &oh32
+	case sizeofOptionalHeader64:
+		if err := binary.Read(sr, binary.LittleEndian, &oh64); err != nil {
+			return nil, err
+		}
+		if oh64.Magic != 0x20b { // PE32+
+			return nil, fmt.Errorf("pe32+ optional header has unexpected Magic of 0x%x", oh64.Magic)
+		}
+		f.OptionalHeader = &oh64
+	}
+
+	// Process sections.
+	f.Sections = make([]*Section, f.FileHeader.NumberOfSections)
+	for i := 0; i < int(f.FileHeader.NumberOfSections); i++ {
+		sh := new(SectionHeader32)
+		if err := binary.Read(sr, binary.LittleEndian, sh); err != nil {
+			return nil, err
+		}
+		var name string
+		if sh.Name[0] == '\x2F' {
+			si, _ := strconv.Atoi(cstring(sh.Name[1:]))
+			name, _ = getString(ss, si)
+		} else {
+			name = cstring(sh.Name[0:])
+		}
+		s := new(Section)
+		s.SectionHeader = SectionHeader{
+			Name:                 name,
+			VirtualSize:          sh.VirtualSize,
+			VirtualAddress:       sh.VirtualAddress,
+			Size:                 sh.SizeOfRawData,
+			Offset:               sh.PointerToRawData,
+			PointerToRelocations: sh.PointerToRelocations,
+			PointerToLineNumbers: sh.PointerToLineNumbers,
+			NumberOfRelocations:  sh.NumberOfRelocations,
+			NumberOfLineNumbers:  sh.NumberOfLineNumbers,
+			Characteristics:      sh.Characteristics,
+		}
+		s.sr = io.NewSectionReader(r, int64(s.SectionHeader.Offset), int64(s.SectionHeader.Size))
+		s.ReaderAt = s.sr
+		f.Sections[i] = s
+	}
+	return f, nil
+}
+
+func cstring(b []byte) string {
+	var i int
+	for i = 0; i < len(b) && b[i] != 0; i++ {
+	}
+	return string(b[0:i])
+}
+
+// getString extracts a string from symbol string table.
+func getString(section []byte, start int) (string, bool) {
+	if start < 0 || start >= len(section) {
+		return "", false
+	}
+
+	for end := start; end < len(section); end++ {
+		if section[end] == 0 {
+			return string(section[start:end]), true
+		}
+	}
+	return "", false
+}
+
+// Section returns the first section with the given name, or nil if no such
+// section exists.
+func (f *File) Section(name string) *Section {
+	for _, s := range f.Sections {
+		if s.Name == name {
+			return s
+		}
+	}
+	return nil
+}
+
+func (f *File) DWARF() (*dwarf.Data, error) {
+	// There are many other DWARF sections, but these
+	// are the required ones, and the debug/dwarf package
+	// does not use the others, so don't bother loading them.
+	var names = [...]string{"abbrev", "info", "str"}
+	var dat [len(names)][]byte
+	for i, name := range names {
+		name = ".debug_" + name
+		s := f.Section(name)
+		if s == nil {
+			continue
+		}
+		b, err := s.Data()
+		if err != nil && uint32(len(b)) < s.Size {
+			return nil, err
+		}
+		dat[i] = b
+	}
+
+	abbrev, info, str := dat[0], dat[1], dat[2]
+	return dwarf.New(abbrev, nil, nil, info, nil, nil, nil, str)
+}
+
+// ImportedSymbols returns the names of all symbols
+// referred to by the binary f that are expected to be
+// satisfied by other libraries at dynamic load time.
+// It does not return weak symbols.
+func (f *File) ImportedSymbols() ([]string, error) {
+	pe64 := f.Machine == IMAGE_FILE_MACHINE_AMD64
+	ds := f.Section(".idata")
+	if ds == nil {
+		// not dynamic, so no libraries
+		return nil, nil
+	}
+	d, err := ds.Data()
+	if err != nil {
+		return nil, err
+	}
+	var ida []ImportDirectory
+	for len(d) > 0 {
+		var dt ImportDirectory
+		dt.OriginalFirstThunk = binary.LittleEndian.Uint32(d[0:4])
+		dt.Name = binary.LittleEndian.Uint32(d[12:16])
+		dt.FirstThunk = binary.LittleEndian.Uint32(d[16:20])
+		d = d[20:]
+		if dt.OriginalFirstThunk == 0 {
+			break
+		}
+		ida = append(ida, dt)
+	}
+	names, _ := ds.Data()
+	var all []string
+	for _, dt := range ida {
+		dt.dll, _ = getString(names, int(dt.Name-ds.VirtualAddress))
+		d, _ = ds.Data()
+		// seek to OriginalFirstThunk
+		d = d[dt.OriginalFirstThunk-ds.VirtualAddress:]
+		for len(d) > 0 {
+			if pe64 { // 64bit
+				va := binary.LittleEndian.Uint64(d[0:8])
+				d = d[8:]
+				if va == 0 {
+					break
+				}
+				if va&0x8000000000000000 > 0 { // is Ordinal
+					// TODO add dynimport ordinal support.
+				} else {
+					fn, _ := getString(names, int(uint32(va)-ds.VirtualAddress+2))
+					all = append(all, fn+":"+dt.dll)
+				}
+			} else { // 32bit
+				va := binary.LittleEndian.Uint32(d[0:4])
+				d = d[4:]
+				if va == 0 {
+					break
+				}
+				if va&0x80000000 > 0 { // is Ordinal
+					// TODO add dynimport ordinal support.
+					//ord := va&0x0000FFFF
+				} else {
+					fn, _ := getString(names, int(va-ds.VirtualAddress+2))
+					all = append(all, fn+":"+dt.dll)
+				}
+			}
+		}
+	}
+
+	return all, nil
+}
+
+// ImportedLibraries returns the names of all libraries
+// referred to by the binary f that are expected to be
+// linked with the binary at dynamic link time.
+func (f *File) ImportedLibraries() ([]string, error) {
+	// TODO
+	// cgo -dynimport don't use this for windows PE, so just return.
+	return nil, nil
+}