Package plan9obj

import "debug/plan9obj"

Overview ▾

Package plan9obj implements access to Plan 9 a.out object files.


This package is not designed to be hardened against adversarial inputs, and is outside the scope of https://go.dev/security/policy. In particular, only basic validation is done when parsing object files. As such, care should be taken when parsing untrusted inputs, as parsing malformed files may consume significant resources, or cause panics.


const (
    Magic64 = 0x8000 // 64-bit expanded header

    Magic386   = (4*11+0)*11 + 7
    MagicAMD64 = (4*26+0)*26 + 7 + Magic64
    MagicARM   = (4*20+0)*20 + 7


ErrNoSymbols is returned by File.Symbols if there is no such section in the File.

var ErrNoSymbols = errors.New("no symbol section")

type File 1.3

A File represents an open Plan 9 a.out file.

type File struct {
    Sections []*Section
    // contains filtered or unexported fields

func NewFile 1.3

func NewFile(r io.ReaderAt) (*File, error)

NewFile creates a new File for accessing a Plan 9 binary in an underlying reader. The Plan 9 binary is expected to start at position 0 in the ReaderAt.

func Open 1.3

func Open(name string) (*File, error)

Open opens the named file using os.Open and prepares it for use as a Plan 9 a.out binary.

func (*File) Close 1.3

func (f *File) Close() error

Close closes the File. If the File was created using NewFile directly instead of Open, Close has no effect.

func (*File) Section 1.3

func (f *File) Section(name string) *Section

Section returns a section with the given name, or nil if no such section exists.

func (*File) Symbols 1.3

func (f *File) Symbols() ([]Sym, error)

Symbols returns the symbol table for f.

type FileHeader 1.3

A FileHeader represents a Plan 9 a.out file header.

type FileHeader struct {
    Magic       uint32
    Bss         uint32
    Entry       uint64
    PtrSize     int
    LoadAddress uint64 // Go 1.4
    HdrSize     uint64 // Go 1.4

type Section 1.3

A Section represents a single section in a Plan 9 a.out file.

type Section struct {

    // 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.
    // contains filtered or unexported fields

func (*Section) Data 1.3

func (s *Section) Data() ([]byte, error)

Data reads and returns the contents of the Plan 9 a.out section.

func (*Section) Open 1.3

func (s *Section) Open() io.ReadSeeker

Open returns a new ReadSeeker reading the Plan 9 a.out section.

type SectionHeader 1.3

A SectionHeader represents a single Plan 9 a.out section header. This structure doesn't exist on-disk, but eases navigation through the object file.

type SectionHeader struct {
    Name   string
    Size   uint32
    Offset uint32

type Sym 1.3

A Symbol represents an entry in a Plan 9 a.out symbol table section.

type Sym struct {
    Value uint64
    Type  rune
    Name  string