Adding upstream version 1.22.1.upstream/1.22.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

12 files changed, 1490 insertions, 0 deletions

diff --git a/src/internal/xcoff/ar.go b/src/internal/xcoff/ar.go
new file mode 100644
index 0000000..9cbd50d
--- /dev/null
+++ b/src/internal/xcoff/ar.go
@@ -0,0 +1,226 @@
+// Copyright 2018 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 xcoff
+
+import (
+	"encoding/binary"
+	"fmt"
+	"io"
+	"os"
+	"strconv"
+	"strings"
+)
+
+const (
+	SAIAMAG   = 0x8
+	AIAFMAG   = "`\n"
+	AIAMAG    = "<aiaff>\n"
+	AIAMAGBIG = "<bigaf>\n"
+
+	// Sizeof
+	FL_HSZ_BIG = 0x80
+	AR_HSZ_BIG = 0x70
+)
+
+type bigarFileHeader struct {
+	Flmagic    [SAIAMAG]byte // Archive magic string
+	Flmemoff   [20]byte      // Member table offset
+	Flgstoff   [20]byte      // 32-bits global symtab offset
+	Flgst64off [20]byte      // 64-bits global symtab offset
+	Flfstmoff  [20]byte      // First member offset
+	Fllstmoff  [20]byte      // Last member offset
+	Flfreeoff  [20]byte      // First member on free list offset
+}
+
+type bigarMemberHeader struct {
+	Arsize   [20]byte // File member size
+	Arnxtmem [20]byte // Next member pointer
+	Arprvmem [20]byte // Previous member pointer
+	Ardate   [12]byte // File member date
+	Aruid    [12]byte // File member uid
+	Argid    [12]byte // File member gid
+	Armode   [12]byte // File member mode (octal)
+	Arnamlen [4]byte  // File member name length
+	// _ar_nam is removed because it's easier to get name without it.
+}
+
+// Archive represents an open AIX big archive.
+type Archive struct {
+	ArchiveHeader
+	Members []*Member
+
+	closer io.Closer
+}
+
+// MemberHeader holds information about a big archive file header
+type ArchiveHeader struct {
+	magic string
+}
+
+// Member represents a member of an AIX big archive.
+type Member struct {
+	MemberHeader
+	sr *io.SectionReader
+}
+
+// MemberHeader holds information about a big archive member
+type MemberHeader struct {
+	Name string
+	Size uint64
+}
+
+// OpenArchive opens the named archive using os.Open and prepares it for use
+// as an AIX big archive.
+func OpenArchive(name string) (*Archive, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	arch, err := NewArchive(f)
+	if err != nil {
+		f.Close()
+		return nil, err
+	}
+	arch.closer = f
+	return arch, nil
+}
+
+// Close closes the Archive.
+// If the Archive was created using NewArchive directly instead of OpenArchive,
+// Close has no effect.
+func (a *Archive) Close() error {
+	var err error
+	if a.closer != nil {
+		err = a.closer.Close()
+		a.closer = nil
+	}
+	return err
+}
+
+// NewArchive creates a new Archive for accessing an AIX big archive in an underlying reader.
+func NewArchive(r io.ReaderAt) (*Archive, error) {
+	parseDecimalBytes := func(b []byte) (int64, error) {
+		return strconv.ParseInt(strings.TrimSpace(string(b)), 10, 64)
+	}
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+
+	// Read File Header
+	var magic [SAIAMAG]byte
+	if _, err := sr.ReadAt(magic[:], 0); err != nil {
+		return nil, err
+	}
+
+	arch := new(Archive)
+	switch string(magic[:]) {
+	case AIAMAGBIG:
+		arch.magic = string(magic[:])
+	case AIAMAG:
+		return nil, fmt.Errorf("small AIX archive not supported")
+	default:
+		return nil, fmt.Errorf("unrecognised archive magic: 0x%x", magic)
+	}
+
+	var fhdr bigarFileHeader
+	if _, err := sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	if err := binary.Read(sr, binary.BigEndian, &fhdr); err != nil {
+		return nil, err
+	}
+
+	off, err := parseDecimalBytes(fhdr.Flfstmoff[:])
+	if err != nil {
+		return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+	}
+
+	if off == 0 {
+		// Occurs if the archive is empty.
+		return arch, nil
+	}
+
+	lastoff, err := parseDecimalBytes(fhdr.Fllstmoff[:])
+	if err != nil {
+		return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+	}
+
+	// Read members
+	for {
+		// Read Member Header
+		// The member header is normally 2 bytes larger. But it's easier
+		// to read the name if the header is read without _ar_nam.
+		// However, AIAFMAG must be read afterward.
+		if _, err := sr.Seek(off, io.SeekStart); err != nil {
+			return nil, err
+		}
+
+		var mhdr bigarMemberHeader
+		if err := binary.Read(sr, binary.BigEndian, &mhdr); err != nil {
+			return nil, err
+		}
+
+		member := new(Member)
+		arch.Members = append(arch.Members, member)
+
+		size, err := parseDecimalBytes(mhdr.Arsize[:])
+		if err != nil {
+			return nil, fmt.Errorf("error parsing size in member header(%q); %v", mhdr, err)
+		}
+		member.Size = uint64(size)
+
+		// Read name
+		namlen, err := parseDecimalBytes(mhdr.Arnamlen[:])
+		if err != nil {
+			return nil, fmt.Errorf("error parsing name length in member header(%q); %v", mhdr, err)
+		}
+		name := make([]byte, namlen)
+		if err := binary.Read(sr, binary.BigEndian, name); err != nil {
+			return nil, err
+		}
+		member.Name = string(name)
+
+		fileoff := off + AR_HSZ_BIG + namlen
+		if fileoff&1 != 0 {
+			fileoff++
+			if _, err := sr.Seek(1, io.SeekCurrent); err != nil {
+				return nil, err
+			}
+		}
+
+		// Read AIAFMAG string
+		var fmag [2]byte
+		if err := binary.Read(sr, binary.BigEndian, &fmag); err != nil {
+			return nil, err
+		}
+		if string(fmag[:]) != AIAFMAG {
+			return nil, fmt.Errorf("AIAFMAG not found after member header")
+		}
+
+		fileoff += 2 // Add the two bytes of AIAFMAG
+		member.sr = io.NewSectionReader(sr, fileoff, size)
+
+		if off == lastoff {
+			break
+		}
+		off, err = parseDecimalBytes(mhdr.Arnxtmem[:])
+		if err != nil {
+			return nil, fmt.Errorf("error parsing offset of first member in archive header(%q); %v", fhdr, err)
+		}
+
+	}
+
+	return arch, nil
+}
+
+// GetFile returns the XCOFF file defined by member name.
+// FIXME: This doesn't work if an archive has two members with the same
+// name which can occur if an archive has both 32-bits and 64-bits files.
+func (arch *Archive) GetFile(name string) (*File, error) {
+	for _, mem := range arch.Members {
+		if mem.Name == name {
+			return NewFile(mem.sr)
+		}
+	}
+	return nil, fmt.Errorf("unknown member %s in archive", name)
+}
diff --git a/src/internal/xcoff/ar_test.go b/src/internal/xcoff/ar_test.go
new file mode 100644
index 0000000..83333d6
--- /dev/null
+++ b/src/internal/xcoff/ar_test.go
@@ -0,0 +1,79 @@
+// Copyright 2018 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 xcoff
+
+import (
+	"reflect"
+	"testing"
+)
+
+type archiveTest struct {
+	file              string
+	hdr               ArchiveHeader
+	members           []*MemberHeader
+	membersFileHeader []FileHeader
+}
+
+var archTest = []archiveTest{
+	{
+		"testdata/bigar-ppc64",
+		ArchiveHeader{AIAMAGBIG},
+		[]*MemberHeader{
+			{"printbye.o", 836},
+			{"printhello.o", 860},
+		},
+		[]FileHeader{
+			{U64_TOCMAGIC},
+			{U64_TOCMAGIC},
+		},
+	},
+	{
+		"testdata/bigar-empty",
+		ArchiveHeader{AIAMAGBIG},
+		[]*MemberHeader{},
+		[]FileHeader{},
+	},
+}
+
+func TestOpenArchive(t *testing.T) {
+	for i := range archTest {
+		tt := &archTest[i]
+		arch, err := OpenArchive(tt.file)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(arch.ArchiveHeader, tt.hdr) {
+			t.Errorf("open archive %s:\n\thave %#v\n\twant %#v\n", tt.file, arch.ArchiveHeader, tt.hdr)
+			continue
+		}
+
+		for i, mem := range arch.Members {
+			if i >= len(tt.members) {
+				break
+			}
+			have := &mem.MemberHeader
+			want := tt.members[i]
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, member %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+
+			f, err := arch.GetFile(mem.Name)
+			if err != nil {
+				t.Error(err)
+				continue
+			}
+			if !reflect.DeepEqual(f.FileHeader, tt.membersFileHeader[i]) {
+				t.Errorf("open %s, member file header %d:\n\thave %#v\n\twant %#v\n", tt.file, i, f.FileHeader, tt.membersFileHeader[i])
+			}
+		}
+		tn := len(tt.members)
+		an := len(arch.Members)
+		if tn != an {
+			t.Errorf("open %s: len(Members) = %d, want %d", tt.file, an, tn)
+		}
+
+	}
+}
diff --git a/src/internal/xcoff/file.go b/src/internal/xcoff/file.go
new file mode 100644
index 0000000..12f78cc
--- /dev/null
+++ b/src/internal/xcoff/file.go
@@ -0,0 +1,697 @@
+// Copyright 2018 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 xcoff implements access to XCOFF (Extended Common Object File Format) files.
+package xcoff
+
+import (
+	"debug/dwarf"
+	"encoding/binary"
+	"fmt"
+	"internal/saferio"
+	"io"
+	"os"
+	"strings"
+)
+
+// SectionHeader holds information about an XCOFF section header.
+type SectionHeader struct {
+	Name           string
+	VirtualAddress uint64
+	Size           uint64
+	Type           uint32
+	Relptr         uint64
+	Nreloc         uint32
+}
+
+type Section struct {
+	SectionHeader
+	Relocs []Reloc
+	io.ReaderAt
+	sr *io.SectionReader
+}
+
+// AuxiliaryCSect holds information about an XCOFF symbol in an AUX_CSECT entry.
+type AuxiliaryCSect struct {
+	Length              int64
+	StorageMappingClass int
+	SymbolType          int
+}
+
+// AuxiliaryFcn holds information about an XCOFF symbol in an AUX_FCN entry.
+type AuxiliaryFcn struct {
+	Size int64
+}
+
+type Symbol struct {
+	Name          string
+	Value         uint64
+	SectionNumber int
+	StorageClass  int
+	AuxFcn        AuxiliaryFcn
+	AuxCSect      AuxiliaryCSect
+}
+
+type Reloc struct {
+	VirtualAddress   uint64
+	Symbol           *Symbol
+	Signed           bool
+	InstructionFixed bool
+	Length           uint8
+	Type             uint8
+}
+
+// ImportedSymbol holds information about an imported XCOFF symbol.
+type ImportedSymbol struct {
+	Name    string
+	Library string
+}
+
+// FileHeader holds information about an XCOFF file header.
+type FileHeader struct {
+	TargetMachine uint16
+}
+
+// A File represents an open XCOFF file.
+type File struct {
+	FileHeader
+	Sections     []*Section
+	Symbols      []*Symbol
+	StringTable  []byte
+	LibraryPaths []string
+
+	closer io.Closer
+}
+
+// Open opens the named file using os.Open and prepares it for use as an XCOFF 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
+}
+
+// Section returns the first section with the given name, or nil if no such
+// section exists.
+// Xcoff have section's name limited to 8 bytes. Some sections like .gosymtab
+// can be trunked but this method will still find them.
+func (f *File) Section(name string) *Section {
+	for _, s := range f.Sections {
+		if s.Name == name || (len(name) > 8 && s.Name == name[:8]) {
+			return s
+		}
+	}
+	return nil
+}
+
+// SectionByType returns the first section in f with the
+// given type, or nil if there is no such section.
+func (f *File) SectionByType(typ uint32) *Section {
+	for _, s := range f.Sections {
+		if s.Type == typ {
+			return s
+		}
+	}
+	return nil
+}
+
+// cstring converts ASCII byte sequence b to string.
+// It stops once it finds 0 or reaches end of b.
+func cstring(b []byte) string {
+	var i int
+	for i = 0; i < len(b) && b[i] != 0; i++ {
+	}
+	return string(b[:i])
+}
+
+// getString extracts a string from an XCOFF string table.
+func getString(st []byte, offset uint32) (string, bool) {
+	if offset < 4 || int(offset) >= len(st) {
+		return "", false
+	}
+	return cstring(st[offset:]), true
+}
+
+// NewFile creates a new File for accessing an XCOFF binary in an underlying reader.
+func NewFile(r io.ReaderAt) (*File, error) {
+	sr := io.NewSectionReader(r, 0, 1<<63-1)
+	// Read XCOFF target machine
+	var magic uint16
+	if err := binary.Read(sr, binary.BigEndian, &magic); err != nil {
+		return nil, err
+	}
+	if magic != U802TOCMAGIC && magic != U64_TOCMAGIC {
+		return nil, fmt.Errorf("unrecognised XCOFF magic: 0x%x", magic)
+	}
+
+	f := new(File)
+	f.TargetMachine = magic
+
+	// Read XCOFF file header
+	if _, err := sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	var nscns uint16
+	var symptr uint64
+	var nsyms uint32
+	var opthdr uint16
+	var hdrsz int
+	switch f.TargetMachine {
+	case U802TOCMAGIC:
+		fhdr := new(FileHeader32)
+		if err := binary.Read(sr, binary.BigEndian, fhdr); err != nil {
+			return nil, err
+		}
+		nscns = fhdr.Fnscns
+		symptr = uint64(fhdr.Fsymptr)
+		nsyms = fhdr.Fnsyms
+		opthdr = fhdr.Fopthdr
+		hdrsz = FILHSZ_32
+	case U64_TOCMAGIC:
+		fhdr := new(FileHeader64)
+		if err := binary.Read(sr, binary.BigEndian, fhdr); err != nil {
+			return nil, err
+		}
+		nscns = fhdr.Fnscns
+		symptr = fhdr.Fsymptr
+		nsyms = fhdr.Fnsyms
+		opthdr = fhdr.Fopthdr
+		hdrsz = FILHSZ_64
+	}
+
+	if symptr == 0 || nsyms <= 0 {
+		return nil, fmt.Errorf("no symbol table")
+	}
+
+	// Read string table (located right after symbol table).
+	offset := symptr + uint64(nsyms)*SYMESZ
+	if _, err := sr.Seek(int64(offset), io.SeekStart); err != nil {
+		return nil, err
+	}
+	// The first 4 bytes contain the length (in bytes).
+	var l uint32
+	if err := binary.Read(sr, binary.BigEndian, &l); err != nil {
+		return nil, err
+	}
+	if l > 4 {
+		st, err := saferio.ReadDataAt(sr, uint64(l), int64(offset))
+		if err != nil {
+			return nil, err
+		}
+		f.StringTable = st
+	}
+
+	// Read section headers
+	if _, err := sr.Seek(int64(hdrsz)+int64(opthdr), io.SeekStart); err != nil {
+		return nil, err
+	}
+	c := saferio.SliceCap[*Section](uint64(nscns))
+	if c < 0 {
+		return nil, fmt.Errorf("too many XCOFF sections (%d)", nscns)
+	}
+	f.Sections = make([]*Section, 0, c)
+	for i := 0; i < int(nscns); i++ {
+		var scnptr uint64
+		s := new(Section)
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			shdr := new(SectionHeader32)
+			if err := binary.Read(sr, binary.BigEndian, shdr); err != nil {
+				return nil, err
+			}
+			s.Name = cstring(shdr.Sname[:])
+			s.VirtualAddress = uint64(shdr.Svaddr)
+			s.Size = uint64(shdr.Ssize)
+			scnptr = uint64(shdr.Sscnptr)
+			s.Type = shdr.Sflags
+			s.Relptr = uint64(shdr.Srelptr)
+			s.Nreloc = uint32(shdr.Snreloc)
+		case U64_TOCMAGIC:
+			shdr := new(SectionHeader64)
+			if err := binary.Read(sr, binary.BigEndian, shdr); err != nil {
+				return nil, err
+			}
+			s.Name = cstring(shdr.Sname[:])
+			s.VirtualAddress = shdr.Svaddr
+			s.Size = shdr.Ssize
+			scnptr = shdr.Sscnptr
+			s.Type = shdr.Sflags
+			s.Relptr = shdr.Srelptr
+			s.Nreloc = shdr.Snreloc
+		}
+		r2 := r
+		if scnptr == 0 { // .bss must have all 0s
+			r2 = zeroReaderAt{}
+		}
+		s.sr = io.NewSectionReader(r2, int64(scnptr), int64(s.Size))
+		s.ReaderAt = s.sr
+		f.Sections = append(f.Sections, s)
+	}
+
+	// Symbol map needed by relocation
+	var idxToSym = make(map[int]*Symbol)
+
+	// Read symbol table
+	if _, err := sr.Seek(int64(symptr), io.SeekStart); err != nil {
+		return nil, err
+	}
+	f.Symbols = make([]*Symbol, 0)
+	for i := 0; i < int(nsyms); i++ {
+		var numaux int
+		var ok, needAuxFcn bool
+		sym := new(Symbol)
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			se := new(SymEnt32)
+			if err := binary.Read(sr, binary.BigEndian, se); err != nil {
+				return nil, err
+			}
+			numaux = int(se.Nnumaux)
+			sym.SectionNumber = int(se.Nscnum)
+			sym.StorageClass = int(se.Nsclass)
+			sym.Value = uint64(se.Nvalue)
+			needAuxFcn = se.Ntype&SYM_TYPE_FUNC != 0 && numaux > 1
+			zeroes := binary.BigEndian.Uint32(se.Nname[:4])
+			if zeroes != 0 {
+				sym.Name = cstring(se.Nname[:])
+			} else {
+				offset := binary.BigEndian.Uint32(se.Nname[4:])
+				sym.Name, ok = getString(f.StringTable, offset)
+				if !ok {
+					goto skip
+				}
+			}
+		case U64_TOCMAGIC:
+			se := new(SymEnt64)
+			if err := binary.Read(sr, binary.BigEndian, se); err != nil {
+				return nil, err
+			}
+			numaux = int(se.Nnumaux)
+			sym.SectionNumber = int(se.Nscnum)
+			sym.StorageClass = int(se.Nsclass)
+			sym.Value = se.Nvalue
+			needAuxFcn = se.Ntype&SYM_TYPE_FUNC != 0 && numaux > 1
+			sym.Name, ok = getString(f.StringTable, se.Noffset)
+			if !ok {
+				goto skip
+			}
+		}
+		if sym.StorageClass != C_EXT && sym.StorageClass != C_WEAKEXT && sym.StorageClass != C_HIDEXT {
+			goto skip
+		}
+		// Must have at least one csect auxiliary entry.
+		if numaux < 1 || i+numaux >= int(nsyms) {
+			goto skip
+		}
+
+		if sym.SectionNumber > int(nscns) {
+			goto skip
+		}
+		if sym.SectionNumber == 0 {
+			sym.Value = 0
+		} else {
+			sym.Value -= f.Sections[sym.SectionNumber-1].VirtualAddress
+		}
+
+		idxToSym[i] = sym
+
+		// If this symbol is a function, it must retrieve its size from
+		// its AUX_FCN entry.
+		// It can happen that a function symbol doesn't have any AUX_FCN.
+		// In this case, needAuxFcn is false and their size will be set to 0.
+		if needAuxFcn {
+			switch f.TargetMachine {
+			case U802TOCMAGIC:
+				aux := new(AuxFcn32)
+				if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+					return nil, err
+				}
+				sym.AuxFcn.Size = int64(aux.Xfsize)
+			case U64_TOCMAGIC:
+				aux := new(AuxFcn64)
+				if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+					return nil, err
+				}
+				sym.AuxFcn.Size = int64(aux.Xfsize)
+			}
+		}
+
+		// Read csect auxiliary entry (by convention, it is the last).
+		if !needAuxFcn {
+			if _, err := sr.Seek(int64(numaux-1)*SYMESZ, io.SeekCurrent); err != nil {
+				return nil, err
+			}
+		}
+		i += numaux
+		numaux = 0
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			aux := new(AuxCSect32)
+			if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+				return nil, err
+			}
+			sym.AuxCSect.SymbolType = int(aux.Xsmtyp & 0x7)
+			sym.AuxCSect.StorageMappingClass = int(aux.Xsmclas)
+			sym.AuxCSect.Length = int64(aux.Xscnlen)
+		case U64_TOCMAGIC:
+			aux := new(AuxCSect64)
+			if err := binary.Read(sr, binary.BigEndian, aux); err != nil {
+				return nil, err
+			}
+			sym.AuxCSect.SymbolType = int(aux.Xsmtyp & 0x7)
+			sym.AuxCSect.StorageMappingClass = int(aux.Xsmclas)
+			sym.AuxCSect.Length = int64(aux.Xscnlenhi)<<32 | int64(aux.Xscnlenlo)
+		}
+		f.Symbols = append(f.Symbols, sym)
+	skip:
+		i += numaux // Skip auxiliary entries
+		if _, err := sr.Seek(int64(numaux)*SYMESZ, io.SeekCurrent); err != nil {
+			return nil, err
+		}
+	}
+
+	// Read relocations
+	// Only for .data or .text section
+	for sectNum, sect := range f.Sections {
+		if sect.Type != STYP_TEXT && sect.Type != STYP_DATA {
+			continue
+		}
+		if sect.Relptr == 0 {
+			continue
+		}
+		c := saferio.SliceCap[Reloc](uint64(sect.Nreloc))
+		if c < 0 {
+			return nil, fmt.Errorf("too many relocs (%d) for section %d", sect.Nreloc, sectNum)
+		}
+		sect.Relocs = make([]Reloc, 0, c)
+		if _, err := sr.Seek(int64(sect.Relptr), io.SeekStart); err != nil {
+			return nil, err
+		}
+		for i := uint32(0); i < sect.Nreloc; i++ {
+			var reloc Reloc
+			switch f.TargetMachine {
+			case U802TOCMAGIC:
+				rel := new(Reloc32)
+				if err := binary.Read(sr, binary.BigEndian, rel); err != nil {
+					return nil, err
+				}
+				reloc.VirtualAddress = uint64(rel.Rvaddr)
+				reloc.Symbol = idxToSym[int(rel.Rsymndx)]
+				reloc.Type = rel.Rtype
+				reloc.Length = rel.Rsize&0x3F + 1
+
+				if rel.Rsize&0x80 != 0 {
+					reloc.Signed = true
+				}
+				if rel.Rsize&0x40 != 0 {
+					reloc.InstructionFixed = true
+				}
+
+			case U64_TOCMAGIC:
+				rel := new(Reloc64)
+				if err := binary.Read(sr, binary.BigEndian, rel); err != nil {
+					return nil, err
+				}
+				reloc.VirtualAddress = rel.Rvaddr
+				reloc.Symbol = idxToSym[int(rel.Rsymndx)]
+				reloc.Type = rel.Rtype
+				reloc.Length = rel.Rsize&0x3F + 1
+				if rel.Rsize&0x80 != 0 {
+					reloc.Signed = true
+				}
+				if rel.Rsize&0x40 != 0 {
+					reloc.InstructionFixed = true
+				}
+			}
+
+			sect.Relocs = append(sect.Relocs, reloc)
+		}
+	}
+
+	return f, nil
+}
+
+// zeroReaderAt is ReaderAt that reads 0s.
+type zeroReaderAt struct{}
+
+// ReadAt writes len(p) 0s into p.
+func (w zeroReaderAt) ReadAt(p []byte, off int64) (n int, err error) {
+	for i := range p {
+		p[i] = 0
+	}
+	return len(p), nil
+}
+
+// Data reads and returns the contents of the XCOFF section s.
+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[:n], err
+}
+
+// CSect reads and returns the contents of a csect.
+func (f *File) CSect(name string) []byte {
+	for _, sym := range f.Symbols {
+		if sym.Name == name && sym.AuxCSect.SymbolType == XTY_SD {
+			if i := sym.SectionNumber - 1; 0 <= i && i < len(f.Sections) {
+				s := f.Sections[i]
+				if sym.Value+uint64(sym.AuxCSect.Length) <= s.Size {
+					dat := make([]byte, sym.AuxCSect.Length)
+					_, err := s.sr.ReadAt(dat, int64(sym.Value))
+					if err != nil {
+						return nil
+					}
+					return dat
+				}
+			}
+			break
+		}
+	}
+	return nil
+}
+
+func (f *File) DWARF() (*dwarf.Data, error) {
+	// There are many other DWARF sections, but these
+	// are the ones the debug/dwarf package uses.
+	// Don't bother loading others.
+	var subtypes = [...]uint32{SSUBTYP_DWABREV, SSUBTYP_DWINFO, SSUBTYP_DWLINE, SSUBTYP_DWRNGES, SSUBTYP_DWSTR}
+	var dat [len(subtypes)][]byte
+	for i, subtype := range subtypes {
+		s := f.SectionByType(STYP_DWARF | subtype)
+		if s != nil {
+			b, err := s.Data()
+			if err != nil && uint64(len(b)) < s.Size {
+				return nil, err
+			}
+			dat[i] = b
+		}
+	}
+
+	abbrev, info, line, ranges, str := dat[0], dat[1], dat[2], dat[3], dat[4]
+	return dwarf.New(abbrev, nil, nil, info, line, nil, ranges, str)
+}
+
+// readImportID returns the import file IDs stored inside the .loader section.
+// Library name pattern is either path/base/member or base/member
+func (f *File) readImportIDs(s *Section) ([]string, error) {
+	// Read loader header
+	if _, err := s.sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	var istlen uint32
+	var nimpid uint32
+	var impoff uint64
+	switch f.TargetMachine {
+	case U802TOCMAGIC:
+		lhdr := new(LoaderHeader32)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		istlen = lhdr.Listlen
+		nimpid = lhdr.Lnimpid
+		impoff = uint64(lhdr.Limpoff)
+	case U64_TOCMAGIC:
+		lhdr := new(LoaderHeader64)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		istlen = lhdr.Listlen
+		nimpid = lhdr.Lnimpid
+		impoff = lhdr.Limpoff
+	}
+
+	// Read loader import file ID table
+	if _, err := s.sr.Seek(int64(impoff), io.SeekStart); err != nil {
+		return nil, err
+	}
+	table := make([]byte, istlen)
+	if _, err := io.ReadFull(s.sr, table); err != nil {
+		return nil, err
+	}
+
+	offset := 0
+	// First import file ID is the default LIBPATH value
+	libpath := cstring(table[offset:])
+	f.LibraryPaths = strings.Split(libpath, ":")
+	offset += len(libpath) + 3 // 3 null bytes
+	all := make([]string, 0)
+	for i := 1; i < int(nimpid); i++ {
+		impidpath := cstring(table[offset:])
+		offset += len(impidpath) + 1
+		impidbase := cstring(table[offset:])
+		offset += len(impidbase) + 1
+		impidmem := cstring(table[offset:])
+		offset += len(impidmem) + 1
+		var path string
+		if len(impidpath) > 0 {
+			path = impidpath + "/" + impidbase + "/" + impidmem
+		} else {
+			path = impidbase + "/" + impidmem
+		}
+		all = append(all, path)
+	}
+
+	return all, nil
+}
+
+// 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() ([]ImportedSymbol, error) {
+	s := f.SectionByType(STYP_LOADER)
+	if s == nil {
+		return nil, nil
+	}
+	// Read loader header
+	if _, err := s.sr.Seek(0, io.SeekStart); err != nil {
+		return nil, err
+	}
+	var stlen uint32
+	var stoff uint64
+	var nsyms uint32
+	var symoff uint64
+	switch f.TargetMachine {
+	case U802TOCMAGIC:
+		lhdr := new(LoaderHeader32)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		stlen = lhdr.Lstlen
+		stoff = uint64(lhdr.Lstoff)
+		nsyms = lhdr.Lnsyms
+		symoff = LDHDRSZ_32
+	case U64_TOCMAGIC:
+		lhdr := new(LoaderHeader64)
+		if err := binary.Read(s.sr, binary.BigEndian, lhdr); err != nil {
+			return nil, err
+		}
+		stlen = lhdr.Lstlen
+		stoff = lhdr.Lstoff
+		nsyms = lhdr.Lnsyms
+		symoff = lhdr.Lsymoff
+	}
+
+	// Read loader section string table
+	if _, err := s.sr.Seek(int64(stoff), io.SeekStart); err != nil {
+		return nil, err
+	}
+	st := make([]byte, stlen)
+	if _, err := io.ReadFull(s.sr, st); err != nil {
+		return nil, err
+	}
+
+	// Read imported libraries
+	libs, err := f.readImportIDs(s)
+	if err != nil {
+		return nil, err
+	}
+
+	// Read loader symbol table
+	if _, err := s.sr.Seek(int64(symoff), io.SeekStart); err != nil {
+		return nil, err
+	}
+	all := make([]ImportedSymbol, 0)
+	for i := 0; i < int(nsyms); i++ {
+		var name string
+		var ifile uint32
+		var ok bool
+		switch f.TargetMachine {
+		case U802TOCMAGIC:
+			ldsym := new(LoaderSymbol32)
+			if err := binary.Read(s.sr, binary.BigEndian, ldsym); err != nil {
+				return nil, err
+			}
+			if ldsym.Lsmtype&0x40 == 0 {
+				continue // Imported symbols only
+			}
+			zeroes := binary.BigEndian.Uint32(ldsym.Lname[:4])
+			if zeroes != 0 {
+				name = cstring(ldsym.Lname[:])
+			} else {
+				offset := binary.BigEndian.Uint32(ldsym.Lname[4:])
+				name, ok = getString(st, offset)
+				if !ok {
+					continue
+				}
+			}
+			ifile = ldsym.Lifile
+		case U64_TOCMAGIC:
+			ldsym := new(LoaderSymbol64)
+			if err := binary.Read(s.sr, binary.BigEndian, ldsym); err != nil {
+				return nil, err
+			}
+			if ldsym.Lsmtype&0x40 == 0 {
+				continue // Imported symbols only
+			}
+			name, ok = getString(st, ldsym.Loffset)
+			if !ok {
+				continue
+			}
+			ifile = ldsym.Lifile
+		}
+		var sym ImportedSymbol
+		sym.Name = name
+		if ifile >= 1 && int(ifile) <= len(libs) {
+			sym.Library = libs[ifile-1]
+		}
+		all = append(all, sym)
+	}
+
+	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) {
+	s := f.SectionByType(STYP_LOADER)
+	if s == nil {
+		return nil, nil
+	}
+	all, err := f.readImportIDs(s)
+	return all, err
+}
diff --git a/src/internal/xcoff/file_test.go b/src/internal/xcoff/file_test.go
new file mode 100644
index 0000000..a6722e9
--- /dev/null
+++ b/src/internal/xcoff/file_test.go
@@ -0,0 +1,102 @@
+// Copyright 2018 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 xcoff
+
+import (
+	"reflect"
+	"testing"
+)
+
+type fileTest struct {
+	file     string
+	hdr      FileHeader
+	sections []*SectionHeader
+	needed   []string
+}
+
+var fileTests = []fileTest{
+	{
+		"testdata/gcc-ppc32-aix-dwarf2-exec",
+		FileHeader{U802TOCMAGIC},
+		[]*SectionHeader{
+			{".text", 0x10000290, 0x00000bbd, STYP_TEXT, 0x7ae6, 0x36},
+			{".data", 0x20000e4d, 0x00000437, STYP_DATA, 0x7d02, 0x2b},
+			{".bss", 0x20001284, 0x0000021c, STYP_BSS, 0, 0},
+			{".loader", 0x00000000, 0x000004b3, STYP_LOADER, 0, 0},
+			{".dwline", 0x00000000, 0x000000df, STYP_DWARF | SSUBTYP_DWLINE, 0x7eb0, 0x7},
+			{".dwinfo", 0x00000000, 0x00000314, STYP_DWARF | SSUBTYP_DWINFO, 0x7ef6, 0xa},
+			{".dwabrev", 0x00000000, 0x000000d6, STYP_DWARF | SSUBTYP_DWABREV, 0, 0},
+			{".dwarnge", 0x00000000, 0x00000020, STYP_DWARF | SSUBTYP_DWARNGE, 0x7f5a, 0x2},
+			{".dwloc", 0x00000000, 0x00000074, STYP_DWARF | SSUBTYP_DWLOC, 0, 0},
+			{".debug", 0x00000000, 0x00005e4f, STYP_DEBUG, 0, 0},
+		},
+		[]string{"libc.a/shr.o"},
+	},
+	{
+		"testdata/gcc-ppc64-aix-dwarf2-exec",
+		FileHeader{U64_TOCMAGIC},
+		[]*SectionHeader{
+			{".text", 0x10000480, 0x00000afd, STYP_TEXT, 0x8322, 0x34},
+			{".data", 0x20000f7d, 0x000002f3, STYP_DATA, 0x85fa, 0x25},
+			{".bss", 0x20001270, 0x00000428, STYP_BSS, 0, 0},
+			{".loader", 0x00000000, 0x00000535, STYP_LOADER, 0, 0},
+			{".dwline", 0x00000000, 0x000000b4, STYP_DWARF | SSUBTYP_DWLINE, 0x8800, 0x4},
+			{".dwinfo", 0x00000000, 0x0000036a, STYP_DWARF | SSUBTYP_DWINFO, 0x8838, 0x7},
+			{".dwabrev", 0x00000000, 0x000000b5, STYP_DWARF | SSUBTYP_DWABREV, 0, 0},
+			{".dwarnge", 0x00000000, 0x00000040, STYP_DWARF | SSUBTYP_DWARNGE, 0x889a, 0x2},
+			{".dwloc", 0x00000000, 0x00000062, STYP_DWARF | SSUBTYP_DWLOC, 0, 0},
+			{".debug", 0x00000000, 0x00006605, STYP_DEBUG, 0, 0},
+		},
+		[]string{"libc.a/shr_64.o"},
+	},
+}
+
+func TestOpen(t *testing.T) {
+	for i := range fileTests {
+		tt := &fileTests[i]
+
+		f, err := Open(tt.file)
+		if err != nil {
+			t.Error(err)
+			continue
+		}
+		if !reflect.DeepEqual(f.FileHeader, tt.hdr) {
+			t.Errorf("open %s:\n\thave %#v\n\twant %#v\n", tt.file, f.FileHeader, tt.hdr)
+			continue
+		}
+
+		for i, sh := range f.Sections {
+			if i >= len(tt.sections) {
+				break
+			}
+			have := &sh.SectionHeader
+			want := tt.sections[i]
+			if !reflect.DeepEqual(have, want) {
+				t.Errorf("open %s, section %d:\n\thave %#v\n\twant %#v\n", tt.file, i, have, want)
+			}
+		}
+		tn := len(tt.sections)
+		fn := len(f.Sections)
+		if tn != fn {
+			t.Errorf("open %s: len(Sections) = %d, want %d", tt.file, fn, tn)
+		}
+		tl := tt.needed
+		fl, err := f.ImportedLibraries()
+		if err != nil {
+			t.Error(err)
+		}
+		if !reflect.DeepEqual(tl, fl) {
+			t.Errorf("open %s: loader import = %v, want %v", tt.file, tl, fl)
+		}
+	}
+}
+
+func TestOpenFailure(t *testing.T) {
+	filename := "file.go"    // not an XCOFF object file
+	_, err := Open(filename) // don't crash
+	if err == nil {
+		t.Errorf("open %s: succeeded unexpectedly", filename)
+	}
+}
diff --git a/src/internal/xcoff/testdata/bigar-empty b/src/internal/xcoff/testdata/bigar-empty
new file mode 100644
index 0000000..851ccc5
--- /dev/null
+++ b/src/internal/xcoff/testdata/bigar-empty
@@ -0,0 +1,2 @@
+<bigaf>
+0                   0                   0                   0                   0                   0                   
\ No newline at end of file
diff --git a/src/internal/xcoff/testdata/bigar-ppc64 b/src/internal/xcoff/testdata/bigar-ppc64
new file mode 100644
index 0000000..a8d4979
--- /dev/null
+++ b/src/internal/xcoff/testdata/bigar-ppc64
diff --git a/src/internal/xcoff/testdata/gcc-ppc32-aix-dwarf2-exec b/src/internal/xcoff/testdata/gcc-ppc32-aix-dwarf2-exec
new file mode 100644
index 0000000..810e21a
--- /dev/null
+++ b/src/internal/xcoff/testdata/gcc-ppc32-aix-dwarf2-exec
diff --git a/src/internal/xcoff/testdata/gcc-ppc64-aix-dwarf2-exec b/src/internal/xcoff/testdata/gcc-ppc64-aix-dwarf2-exec
new file mode 100644
index 0000000..707d01e
--- /dev/null
+++ b/src/internal/xcoff/testdata/gcc-ppc64-aix-dwarf2-exec
diff --git a/src/internal/xcoff/testdata/hello.c b/src/internal/xcoff/testdata/hello.c
new file mode 100644
index 0000000..34d9ee7
--- /dev/null
+++ b/src/internal/xcoff/testdata/hello.c
@@ -0,0 +1,7 @@
+#include <stdio.h>
+
+void
+main(int argc, char *argv[])
+{
+	printf("hello, world\n");
+}
diff --git a/src/internal/xcoff/testdata/printbye.c b/src/internal/xcoff/testdata/printbye.c
new file mode 100644
index 0000000..9045079
--- /dev/null
+++ b/src/internal/xcoff/testdata/printbye.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+void printbye(){
+	printf("Goodbye\n");
+}
diff --git a/src/internal/xcoff/testdata/printhello.c b/src/internal/xcoff/testdata/printhello.c
new file mode 100644
index 0000000..182aa09
--- /dev/null
+++ b/src/internal/xcoff/testdata/printhello.c
@@ -0,0 +1,5 @@
+#include <stdio.h>
+
+void printhello(){
+	printf("Helloworld\n");
+}
diff --git a/src/internal/xcoff/xcoff.go b/src/internal/xcoff/xcoff.go
new file mode 100644
index 0000000..db81542
--- /dev/null
+++ b/src/internal/xcoff/xcoff.go
@@ -0,0 +1,367 @@
+// Copyright 2018 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 xcoff
+
+// File Header.
+type FileHeader32 struct {
+	Fmagic   uint16 // Target machine
+	Fnscns   uint16 // Number of sections
+	Ftimedat uint32 // Time and date of file creation
+	Fsymptr  uint32 // Byte offset to symbol table start
+	Fnsyms   uint32 // Number of entries in symbol table
+	Fopthdr  uint16 // Number of bytes in optional header
+	Fflags   uint16 // Flags
+}
+
+type FileHeader64 struct {
+	Fmagic   uint16 // Target machine
+	Fnscns   uint16 // Number of sections
+	Ftimedat uint32 // Time and date of file creation
+	Fsymptr  uint64 // Byte offset to symbol table start
+	Fopthdr  uint16 // Number of bytes in optional header
+	Fflags   uint16 // Flags
+	Fnsyms   uint32 // Number of entries in symbol table
+}
+
+const (
+	FILHSZ_32 = 20
+	FILHSZ_64 = 24
+)
+const (
+	U802TOCMAGIC = 0737 // AIX 32-bit XCOFF
+	U64_TOCMAGIC = 0767 // AIX 64-bit XCOFF
+)
+
+// Flags that describe the type of the object file.
+const (
+	F_RELFLG    = 0x0001
+	F_EXEC      = 0x0002
+	F_LNNO      = 0x0004
+	F_FDPR_PROF = 0x0010
+	F_FDPR_OPTI = 0x0020
+	F_DSA       = 0x0040
+	F_VARPG     = 0x0100
+	F_DYNLOAD   = 0x1000
+	F_SHROBJ    = 0x2000
+	F_LOADONLY  = 0x4000
+)
+
+// Section Header.
+type SectionHeader32 struct {
+	Sname    [8]byte // Section name
+	Spaddr   uint32  // Physical address
+	Svaddr   uint32  // Virtual address
+	Ssize    uint32  // Section size
+	Sscnptr  uint32  // Offset in file to raw data for section
+	Srelptr  uint32  // Offset in file to relocation entries for section
+	Slnnoptr uint32  // Offset in file to line number entries for section
+	Snreloc  uint16  // Number of relocation entries
+	Snlnno   uint16  // Number of line number entries
+	Sflags   uint32  // Flags to define the section type
+}
+
+type SectionHeader64 struct {
+	Sname    [8]byte // Section name
+	Spaddr   uint64  // Physical address
+	Svaddr   uint64  // Virtual address
+	Ssize    uint64  // Section size
+	Sscnptr  uint64  // Offset in file to raw data for section
+	Srelptr  uint64  // Offset in file to relocation entries for section
+	Slnnoptr uint64  // Offset in file to line number entries for section
+	Snreloc  uint32  // Number of relocation entries
+	Snlnno   uint32  // Number of line number entries
+	Sflags   uint32  // Flags to define the section type
+	Spad     uint32  // Needs to be 72 bytes long
+}
+
+// Flags defining the section type.
+const (
+	STYP_DWARF  = 0x0010
+	STYP_TEXT   = 0x0020
+	STYP_DATA   = 0x0040
+	STYP_BSS    = 0x0080
+	STYP_EXCEPT = 0x0100
+	STYP_INFO   = 0x0200
+	STYP_TDATA  = 0x0400
+	STYP_TBSS   = 0x0800
+	STYP_LOADER = 0x1000
+	STYP_DEBUG  = 0x2000
+	STYP_TYPCHK = 0x4000
+	STYP_OVRFLO = 0x8000
+)
+const (
+	SSUBTYP_DWINFO  = 0x10000 // DWARF info section
+	SSUBTYP_DWLINE  = 0x20000 // DWARF line-number section
+	SSUBTYP_DWPBNMS = 0x30000 // DWARF public names section
+	SSUBTYP_DWPBTYP = 0x40000 // DWARF public types section
+	SSUBTYP_DWARNGE = 0x50000 // DWARF aranges section
+	SSUBTYP_DWABREV = 0x60000 // DWARF abbreviation section
+	SSUBTYP_DWSTR   = 0x70000 // DWARF strings section
+	SSUBTYP_DWRNGES = 0x80000 // DWARF ranges section
+	SSUBTYP_DWLOC   = 0x90000 // DWARF location lists section
+	SSUBTYP_DWFRAME = 0xA0000 // DWARF frames section
+	SSUBTYP_DWMAC   = 0xB0000 // DWARF macros section
+)
+
+// Symbol Table Entry.
+type SymEnt32 struct {
+	Nname   [8]byte // Symbol name
+	Nvalue  uint32  // Symbol value
+	Nscnum  uint16  // Section number of symbol
+	Ntype   uint16  // Basic and derived type specification
+	Nsclass uint8   // Storage class of symbol
+	Nnumaux uint8   // Number of auxiliary entries
+}
+
+type SymEnt64 struct {
+	Nvalue  uint64 // Symbol value
+	Noffset uint32 // Offset of the name in string table or .debug section
+	Nscnum  uint16 // Section number of symbol
+	Ntype   uint16 // Basic and derived type specification
+	Nsclass uint8  // Storage class of symbol
+	Nnumaux uint8  // Number of auxiliary entries
+}
+
+const SYMESZ = 18
+
+const (
+	// Nscnum
+	N_DEBUG = -2
+	N_ABS   = -1
+	N_UNDEF = 0
+
+	//Ntype
+	SYM_V_INTERNAL  = 0x1000
+	SYM_V_HIDDEN    = 0x2000
+	SYM_V_PROTECTED = 0x3000
+	SYM_V_EXPORTED  = 0x4000
+	SYM_TYPE_FUNC   = 0x0020 // is function
+)
+
+// Storage Class.
+const (
+	C_NULL    = 0   // Symbol table entry marked for deletion
+	C_EXT     = 2   // External symbol
+	C_STAT    = 3   // Static symbol
+	C_BLOCK   = 100 // Beginning or end of inner block
+	C_FCN     = 101 // Beginning or end of function
+	C_FILE    = 103 // Source file name and compiler information
+	C_HIDEXT  = 107 // Unnamed external symbol
+	C_BINCL   = 108 // Beginning of include file
+	C_EINCL   = 109 // End of include file
+	C_WEAKEXT = 111 // Weak external symbol
+	C_DWARF   = 112 // DWARF symbol
+	C_GSYM    = 128 // Global variable
+	C_LSYM    = 129 // Automatic variable allocated on stack
+	C_PSYM    = 130 // Argument to subroutine allocated on stack
+	C_RSYM    = 131 // Register variable
+	C_RPSYM   = 132 // Argument to function or procedure stored in register
+	C_STSYM   = 133 // Statically allocated symbol
+	C_BCOMM   = 135 // Beginning of common block
+	C_ECOML   = 136 // Local member of common block
+	C_ECOMM   = 137 // End of common block
+	C_DECL    = 140 // Declaration of object
+	C_ENTRY   = 141 // Alternate entry
+	C_FUN     = 142 // Function or procedure
+	C_BSTAT   = 143 // Beginning of static block
+	C_ESTAT   = 144 // End of static block
+	C_GTLS    = 145 // Global thread-local variable
+	C_STTLS   = 146 // Static thread-local variable
+)
+
+// File Auxiliary Entry
+type AuxFile64 struct {
+	Xfname   [8]byte // Name or offset inside string table
+	Xftype   uint8   // Source file string type
+	Xauxtype uint8   // Type of auxiliary entry
+}
+
+// Function Auxiliary Entry
+type AuxFcn32 struct {
+	Xexptr   uint32 // File offset to exception table entry
+	Xfsize   uint32 // Size of function in bytes
+	Xlnnoptr uint32 // File pointer to line number
+	Xendndx  uint32 // Symbol table index of next entry
+	Xpad     uint16 // Unused
+}
+type AuxFcn64 struct {
+	Xlnnoptr uint64 // File pointer to line number
+	Xfsize   uint32 // Size of function in bytes
+	Xendndx  uint32 // Symbol table index of next entry
+	Xpad     uint8  // Unused
+	Xauxtype uint8  // Type of auxiliary entry
+}
+
+type AuxSect64 struct {
+	Xscnlen  uint64 // section length
+	Xnreloc  uint64 // Num RLDs
+	pad      uint8
+	Xauxtype uint8 // Type of auxiliary entry
+}
+
+// csect Auxiliary Entry.
+type AuxCSect32 struct {
+	Xscnlen   uint32 // Length or symbol table index
+	Xparmhash uint32 // Offset of parameter type-check string
+	Xsnhash   uint16 // .typchk section number
+	Xsmtyp    uint8  // Symbol alignment and type
+	Xsmclas   uint8  // Storage-mapping class
+	Xstab     uint32 // Reserved
+	Xsnstab   uint16 // Reserved
+}
+
+type AuxCSect64 struct {
+	Xscnlenlo uint32 // Lower 4 bytes of length or symbol table index
+	Xparmhash uint32 // Offset of parameter type-check string
+	Xsnhash   uint16 // .typchk section number
+	Xsmtyp    uint8  // Symbol alignment and type
+	Xsmclas   uint8  // Storage-mapping class
+	Xscnlenhi uint32 // Upper 4 bytes of length or symbol table index
+	Xpad      uint8  // Unused
+	Xauxtype  uint8  // Type of auxiliary entry
+}
+
+// Auxiliary type
+const (
+	_AUX_EXCEPT = 255
+	_AUX_FCN    = 254
+	_AUX_SYM    = 253
+	_AUX_FILE   = 252
+	_AUX_CSECT  = 251
+	_AUX_SECT   = 250
+)
+
+// Symbol type field.
+const (
+	XTY_ER = 0 // External reference
+	XTY_SD = 1 // Section definition
+	XTY_LD = 2 // Label definition
+	XTY_CM = 3 // Common csect definition
+)
+
+// Defines for File auxiliary definitions: x_ftype field of x_file
+const (
+	XFT_FN = 0   // Source File Name
+	XFT_CT = 1   // Compile Time Stamp
+	XFT_CV = 2   // Compiler Version Number
+	XFT_CD = 128 // Compiler Defined Information
+)
+
+// Storage-mapping class.
+const (
+	XMC_PR     = 0  // Program code
+	XMC_RO     = 1  // Read-only constant
+	XMC_DB     = 2  // Debug dictionary table
+	XMC_TC     = 3  // TOC entry
+	XMC_UA     = 4  // Unclassified
+	XMC_RW     = 5  // Read/Write data
+	XMC_GL     = 6  // Global linkage
+	XMC_XO     = 7  // Extended operation
+	XMC_SV     = 8  // 32-bit supervisor call descriptor
+	XMC_BS     = 9  // BSS class
+	XMC_DS     = 10 // Function descriptor
+	XMC_UC     = 11 // Unnamed FORTRAN common
+	XMC_TC0    = 15 // TOC anchor
+	XMC_TD     = 16 // Scalar data entry in the TOC
+	XMC_SV64   = 17 // 64-bit supervisor call descriptor
+	XMC_SV3264 = 18 // Supervisor call descriptor for both 32-bit and 64-bit
+	XMC_TL     = 20 // Read/Write thread-local data
+	XMC_UL     = 21 // Read/Write thread-local data (.tbss)
+	XMC_TE     = 22 // TOC entry
+)
+
+// Loader Header.
+type LoaderHeader32 struct {
+	Lversion uint32 // Loader section version number
+	Lnsyms   uint32 // Number of symbol table entries
+	Lnreloc  uint32 // Number of relocation table entries
+	Listlen  uint32 // Length of import file ID string table
+	Lnimpid  uint32 // Number of import file IDs
+	Limpoff  uint32 // Offset to start of import file IDs
+	Lstlen   uint32 // Length of string table
+	Lstoff   uint32 // Offset to start of string table
+}
+
+type LoaderHeader64 struct {
+	Lversion uint32 // Loader section version number
+	Lnsyms   uint32 // Number of symbol table entries
+	Lnreloc  uint32 // Number of relocation table entries
+	Listlen  uint32 // Length of import file ID string table
+	Lnimpid  uint32 // Number of import file IDs
+	Lstlen   uint32 // Length of string table
+	Limpoff  uint64 // Offset to start of import file IDs
+	Lstoff   uint64 // Offset to start of string table
+	Lsymoff  uint64 // Offset to start of symbol table
+	Lrldoff  uint64 // Offset to start of relocation entries
+}
+
+const (
+	LDHDRSZ_32 = 32
+	LDHDRSZ_64 = 56
+)
+
+// Loader Symbol.
+type LoaderSymbol32 struct {
+	Lname   [8]byte // Symbol name or byte offset into string table
+	Lvalue  uint32  // Address field
+	Lscnum  uint16  // Section number containing symbol
+	Lsmtype uint8   // Symbol type, export, import flags
+	Lsmclas uint8   // Symbol storage class
+	Lifile  uint32  // Import file ID; ordinal of import file IDs
+	Lparm   uint32  // Parameter type-check field
+}
+
+type LoaderSymbol64 struct {
+	Lvalue  uint64 // Address field
+	Loffset uint32 // Byte offset into string table of symbol name
+	Lscnum  uint16 // Section number containing symbol
+	Lsmtype uint8  // Symbol type, export, import flags
+	Lsmclas uint8  // Symbol storage class
+	Lifile  uint32 // Import file ID; ordinal of import file IDs
+	Lparm   uint32 // Parameter type-check field
+}
+
+type Reloc32 struct {
+	Rvaddr  uint32 // (virtual) address of reference
+	Rsymndx uint32 // Index into symbol table
+	Rsize   uint8  // Sign and reloc bit len
+	Rtype   uint8  // Toc relocation type
+}
+
+type Reloc64 struct {
+	Rvaddr  uint64 // (virtual) address of reference
+	Rsymndx uint32 // Index into symbol table
+	Rsize   uint8  // Sign and reloc bit len
+	Rtype   uint8  // Toc relocation type
+}
+
+const (
+	R_POS = 0x00 // A(sym) Positive Relocation
+	R_NEG = 0x01 // -A(sym) Negative Relocation
+	R_REL = 0x02 // A(sym-*) Relative to self
+	R_TOC = 0x03 // A(sym-TOC) Relative to TOC
+	R_TRL = 0x12 // A(sym-TOC) TOC Relative indirect load.
+
+	R_TRLA = 0x13 // A(sym-TOC) TOC Rel load address. modifiable inst
+	R_GL   = 0x05 // A(external TOC of sym) Global Linkage
+	R_TCL  = 0x06 // A(local TOC of sym) Local object TOC address
+	R_RL   = 0x0C // A(sym) Pos indirect load. modifiable instruction
+	R_RLA  = 0x0D // A(sym) Pos Load Address. modifiable instruction
+	R_REF  = 0x0F // AL0(sym) Non relocating ref. No garbage collect
+	R_BA   = 0x08 // A(sym) Branch absolute. Cannot modify instruction
+	R_RBA  = 0x18 // A(sym) Branch absolute. modifiable instruction
+	R_BR   = 0x0A // A(sym-*) Branch rel to self. non modifiable
+	R_RBR  = 0x1A // A(sym-*) Branch rel to self. modifiable instr
+
+	R_TLS    = 0x20 // General-dynamic reference to TLS symbol
+	R_TLS_IE = 0x21 // Initial-exec reference to TLS symbol
+	R_TLS_LD = 0x22 // Local-dynamic reference to TLS symbol
+	R_TLS_LE = 0x23 // Local-exec reference to TLS symbol
+	R_TLSM   = 0x24 // Module reference to TLS symbol
+	R_TLSML  = 0x25 // Module reference to local (own) module
+
+	R_TOCU = 0x30 // Relative to TOC - high order bits
+	R_TOCL = 0x31 // Relative to TOC - low order bits
+)