debug/goobj: move to cmd/internal/goobj

debug/goobj is not ready to be published but it is
needed for the various binary-reading commands.
Move to cmd/internal/goobj.

(The Go 1.3 release branch deleted it, but that's not
an option anymore due to the command dependencies.
The API is still not vetted nor terribly well designed.)

LGTM=adg, dsymonds
R=adg, dsymonds
CC=golang-codereviews
https://codereview.appspot.com/174250043

2 files changed, 0 insertions, 694 deletions

diff --git a/src/debug/goobj/read.go b/src/debug/goobj/read.go
deleted file mode 100644
index 79a83e59a..000000000
--- a/src/debug/goobj/read.go
+++ /dev/null
@@ -1,666 +0,0 @@
-// 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.
-
-// Package goobj implements reading of Go object files and archives.
-//
-// TODO(rsc): Decide where this package should live. (golang.org/issue/6932)
-// TODO(rsc): Decide the appropriate integer types for various fields.
-// TODO(rsc): Write tests. (File format still up in the air a little.)
-package goobj
-
-import (
-	"bufio"
-	"bytes"
-	"errors"
-	"fmt"
-	"io"
-	"strconv"
-	"strings"
-)
-
-// A SymKind describes the kind of memory represented by a symbol.
-type SymKind int
-
-// This list is taken from include/link.h.
-
-// Defined SymKind values.
-// TODO(rsc): Give idiomatic Go names.
-// TODO(rsc): Reduce the number of symbol types in the object files.
-const (
-	_ SymKind = iota
-
-	// readonly, executable
-	STEXT
-	SELFRXSECT
-
-	// readonly, non-executable
-	STYPE
-	SSTRING
-	SGOSTRING
-	SGOFUNC
-	SRODATA
-	SFUNCTAB
-	STYPELINK
-	SSYMTAB // TODO: move to unmapped section
-	SPCLNTAB
-	SELFROSECT
-
-	// writable, non-executable
-	SMACHOPLT
-	SELFSECT
-	SMACHO // Mach-O __nl_symbol_ptr
-	SMACHOGOT
-	SNOPTRDATA
-	SINITARR
-	SDATA
-	SWINDOWS
-	SBSS
-	SNOPTRBSS
-	STLSBSS
-
-	// not mapped
-	SXREF
-	SMACHOSYMSTR
-	SMACHOSYMTAB
-	SMACHOINDIRECTPLT
-	SMACHOINDIRECTGOT
-	SFILE
-	SFILEPATH
-	SCONST
-	SDYNIMPORT
-	SHOSTOBJ
-)
-
-var symKindStrings = []string{
-	SBSS:              "SBSS",
-	SCONST:            "SCONST",
-	SDATA:             "SDATA",
-	SDYNIMPORT:        "SDYNIMPORT",
-	SELFROSECT:        "SELFROSECT",
-	SELFRXSECT:        "SELFRXSECT",
-	SELFSECT:          "SELFSECT",
-	SFILE:             "SFILE",
-	SFILEPATH:         "SFILEPATH",
-	SFUNCTAB:          "SFUNCTAB",
-	SGOFUNC:           "SGOFUNC",
-	SGOSTRING:         "SGOSTRING",
-	SHOSTOBJ:          "SHOSTOBJ",
-	SINITARR:          "SINITARR",
-	SMACHO:            "SMACHO",
-	SMACHOGOT:         "SMACHOGOT",
-	SMACHOINDIRECTGOT: "SMACHOINDIRECTGOT",
-	SMACHOINDIRECTPLT: "SMACHOINDIRECTPLT",
-	SMACHOPLT:         "SMACHOPLT",
-	SMACHOSYMSTR:      "SMACHOSYMSTR",
-	SMACHOSYMTAB:      "SMACHOSYMTAB",
-	SNOPTRBSS:         "SNOPTRBSS",
-	SNOPTRDATA:        "SNOPTRDATA",
-	SPCLNTAB:          "SPCLNTAB",
-	SRODATA:           "SRODATA",
-	SSTRING:           "SSTRING",
-	SSYMTAB:           "SSYMTAB",
-	STEXT:             "STEXT",
-	STLSBSS:           "STLSBSS",
-	STYPE:             "STYPE",
-	STYPELINK:         "STYPELINK",
-	SWINDOWS:          "SWINDOWS",
-	SXREF:             "SXREF",
-}
-
-func (k SymKind) String() string {
-	if k < 0 || int(k) >= len(symKindStrings) {
-		return fmt.Sprintf("SymKind(%d)", k)
-	}
-	return symKindStrings[k]
-}
-
-// A Sym is a named symbol in an object file.
-type Sym struct {
-	SymID         // symbol identifier (name and version)
-	Kind  SymKind // kind of symbol
-	DupOK bool    // are duplicate definitions okay?
-	Size  int     // size of corresponding data
-	Type  SymID   // symbol for Go type information
-	Data  Data    // memory image of symbol
-	Reloc []Reloc // relocations to apply to Data
-	Func  *Func   // additional data for functions
-}
-
-// A SymID - the combination of Name and Version - uniquely identifies
-// a symbol within a package.
-type SymID struct {
-	// Name is the name of a symbol.
-	Name string
-
-	// Version is zero for symbols with global visibility.
-	// Symbols with only file visibility (such as file-level static
-	// declarations in C) have a non-zero version distinguishing
-	// a symbol in one file from a symbol of the same name
-	// in another file
-	Version int
-}
-
-func (s SymID) String() string {
-	if s.Version == 0 {
-		return s.Name
-	}
-	return fmt.Sprintf("%s<%d>", s.Name, s.Version)
-}
-
-// A Data is a reference to data stored in an object file.
-// It records the offset and size of the data, so that a client can
-// read the data only if necessary.
-type Data struct {
-	Offset int64
-	Size   int64
-}
-
-// A Reloc describes a relocation applied to a memory image to refer
-// to an address within a particular symbol.
-type Reloc struct {
-	// The bytes at [Offset, Offset+Size) within the memory image
-	// should be updated to refer to the address Add bytes after the start
-	// of the symbol Sym.
-	Offset int
-	Size   int
-	Sym    SymID
-	Add    int
-
-	// The Type records the form of address expected in the bytes
-	// described by the previous fields: absolute, PC-relative, and so on.
-	// TODO(rsc): The interpretation of Type is not exposed by this package.
-	Type int
-}
-
-// A Var describes a variable in a function stack frame: a declared
-// local variable, an input argument, or an output result.
-type Var struct {
-	// The combination of Name, Kind, and Offset uniquely
-	// identifies a variable in a function stack frame.
-	// Using fewer of these - in particular, using only Name - does not.
-	Name   string // Name of variable.
-	Kind   int    // TODO(rsc): Define meaning.
-	Offset int    // Frame offset. TODO(rsc): Define meaning.
-
-	Type SymID // Go type for variable.
-}
-
-// Func contains additional per-symbol information specific to functions.
-type Func struct {
-	Args     int        // size in bytes of argument frame: inputs and outputs
-	Frame    int        // size in bytes of local variable frame
-	Leaf     bool       // function omits save of link register (ARM)
-	NoSplit  bool       // function omits stack split prologue
-	Var      []Var      // detail about local variables
-	PCSP     Data       // PC → SP offset map
-	PCFile   Data       // PC → file number map (index into File)
-	PCLine   Data       // PC → line number map
-	PCData   []Data     // PC → runtime support data map
-	FuncData []FuncData // non-PC-specific runtime support data
-	File     []string   // paths indexed by PCFile
-}
-
-// TODO: Add PCData []byte and PCDataIter (similar to liblink).
-
-// A FuncData is a single function-specific data value.
-type FuncData struct {
-	Sym    SymID // symbol holding data
-	Offset int64 // offset into symbol for funcdata pointer
-}
-
-// A Package is a parsed Go object file or archive defining a Go package.
-type Package struct {
-	ImportPath string   // import path denoting this package
-	Imports    []string // packages imported by this package
-	Syms       []*Sym   // symbols defined by this package
-	MaxVersion int      // maximum Version in any SymID in Syms
-}
-
-var (
-	archiveHeader = []byte("!<arch>\n")
-	archiveMagic  = []byte("`\n")
-	goobjHeader   = []byte("go objec") // truncated to size of archiveHeader
-
-	errCorruptArchive   = errors.New("corrupt archive")
-	errTruncatedArchive = errors.New("truncated archive")
-	errNotArchive       = errors.New("unrecognized archive format")
-
-	errCorruptObject   = errors.New("corrupt object file")
-	errTruncatedObject = errors.New("truncated object file")
-	errNotObject       = errors.New("unrecognized object file format")
-)
-
-// An objReader is an object file reader.
-type objReader struct {
-	p         *Package
-	b         *bufio.Reader
-	f         io.ReadSeeker
-	err       error
-	offset    int64
-	limit     int64
-	tmp       [256]byte
-	pkg       string
-	pkgprefix string
-}
-
-// importPathToPrefix returns the prefix that will be used in the
-// final symbol table for the given import path.
-// We escape '%', '"', all control characters and non-ASCII bytes,
-// and any '.' after the final slash.
-//
-// See ../../../cmd/ld/lib.c:/^pathtoprefix and
-// ../../../cmd/gc/subr.c:/^pathtoprefix.
-func importPathToPrefix(s string) string {
-	// find index of last slash, if any, or else -1.
-	// used for determining whether an index is after the last slash.
-	slash := strings.LastIndex(s, "/")
-
-	// check for chars that need escaping
-	n := 0
-	for r := 0; r < len(s); r++ {
-		if c := s[r]; c <= ' ' || (c == '.' && r > slash) || c == '%' || c == '"' || c >= 0x7F {
-			n++
-		}
-	}
-
-	// quick exit
-	if n == 0 {
-		return s
-	}
-
-	// escape
-	const hex = "0123456789abcdef"
-	p := make([]byte, 0, len(s)+2*n)
-	for r := 0; r < len(s); r++ {
-		if c := s[r]; c <= ' ' || (c == '.' && r > slash) || c == '%' || c == '"' || c >= 0x7F {
-			p = append(p, '%', hex[c>>4], hex[c&0xF])
-		} else {
-			p = append(p, c)
-		}
-	}
-
-	return string(p)
-}
-
-// init initializes r to read package p from f.
-func (r *objReader) init(f io.ReadSeeker, p *Package) {
-	r.f = f
-	r.p = p
-	r.offset, _ = f.Seek(0, 1)
-	r.limit, _ = f.Seek(0, 2)
-	f.Seek(r.offset, 0)
-	r.b = bufio.NewReader(f)
-	r.pkgprefix = importPathToPrefix(p.ImportPath) + "."
-}
-
-// error records that an error occurred.
-// It returns only the first error, so that an error
-// caused by an earlier error does not discard information
-// about the earlier error.
-func (r *objReader) error(err error) error {
-	if r.err == nil {
-		if err == io.EOF {
-			err = io.ErrUnexpectedEOF
-		}
-		r.err = err
-	}
-	// panic("corrupt") // useful for debugging
-	return r.err
-}
-
-// readByte reads and returns a byte from the input file.
-// On I/O error or EOF, it records the error but returns byte 0.
-// A sequence of 0 bytes will eventually terminate any
-// parsing state in the object file. In particular, it ends the
-// reading of a varint.
-func (r *objReader) readByte() byte {
-	if r.err != nil {
-		return 0
-	}
-	if r.offset >= r.limit {
-		r.error(io.ErrUnexpectedEOF)
-		return 0
-	}
-	b, err := r.b.ReadByte()
-	if err != nil {
-		if err == io.EOF {
-			err = io.ErrUnexpectedEOF
-		}
-		r.error(err)
-		b = 0
-	} else {
-		r.offset++
-	}
-	return b
-}
-
-// read reads exactly len(b) bytes from the input file.
-// If an error occurs, read returns the error but also
-// records it, so it is safe for callers to ignore the result
-// as long as delaying the report is not a problem.
-func (r *objReader) readFull(b []byte) error {
-	if r.err != nil {
-		return r.err
-	}
-	if r.offset+int64(len(b)) > r.limit {
-		return r.error(io.ErrUnexpectedEOF)
-	}
-	n, err := io.ReadFull(r.b, b)
-	r.offset += int64(n)
-	if err != nil {
-		return r.error(err)
-	}
-	return nil
-}
-
-// readInt reads a zigzag varint from the input file.
-func (r *objReader) readInt() int {
-	var u uint64
-
-	for shift := uint(0); ; shift += 7 {
-		if shift >= 64 {
-			r.error(errCorruptObject)
-			return 0
-		}
-		c := r.readByte()
-		u |= uint64(c&0x7F) << shift
-		if c&0x80 == 0 {
-			break
-		}
-	}
-
-	v := int64(u>>1) ^ (int64(u) << 63 >> 63)
-	if int64(int(v)) != v {
-		r.error(errCorruptObject) // TODO
-		return 0
-	}
-	return int(v)
-}
-
-// readString reads a length-delimited string from the input file.
-func (r *objReader) readString() string {
-	n := r.readInt()
-	buf := make([]byte, n)
-	r.readFull(buf)
-	return string(buf)
-}
-
-// readSymID reads a SymID from the input file.
-func (r *objReader) readSymID() SymID {
-	name, vers := r.readString(), r.readInt()
-
-	// In a symbol name in an object file, "". denotes the
-	// prefix for the package in which the object file has been found.
-	// Expand it.
-	name = strings.Replace(name, `"".`, r.pkgprefix, -1)
-
-	// An individual object file only records version 0 (extern) or 1 (static).
-	// To make static symbols unique across all files being read, we
-	// replace version 1 with the version corresponding to the current
-	// file number. The number is incremented on each call to parseObject.
-	if vers != 0 {
-		vers = r.p.MaxVersion
-	}
-
-	return SymID{name, vers}
-}
-
-// readData reads a data reference from the input file.
-func (r *objReader) readData() Data {
-	n := r.readInt()
-	d := Data{Offset: r.offset, Size: int64(n)}
-	r.skip(int64(n))
-	return d
-}
-
-// skip skips n bytes in the input.
-func (r *objReader) skip(n int64) {
-	if n < 0 {
-		r.error(fmt.Errorf("debug/goobj: internal error: misuse of skip"))
-	}
-	if n < int64(len(r.tmp)) {
-		// Since the data is so small, a just reading from the buffered
-		// reader is better than flushing the buffer and seeking.
-		r.readFull(r.tmp[:n])
-	} else if n <= int64(r.b.Buffered()) {
-		// Even though the data is not small, it has already been read.
-		// Advance the buffer instead of seeking.
-		for n > int64(len(r.tmp)) {
-			r.readFull(r.tmp[:])
-			n -= int64(len(r.tmp))
-		}
-		r.readFull(r.tmp[:n])
-	} else {
-		// Seek, giving up buffered data.
-		_, err := r.f.Seek(r.offset+n, 0)
-		if err != nil {
-			r.error(err)
-		}
-		r.offset += n
-		r.b.Reset(r.f)
-	}
-}
-
-// Parse parses an object file or archive from r,
-// assuming that its import path is pkgpath.
-func Parse(r io.ReadSeeker, pkgpath string) (*Package, error) {
-	if pkgpath == "" {
-		pkgpath = `""`
-	}
-	p := new(Package)
-	p.ImportPath = pkgpath
-
-	var rd objReader
-	rd.init(r, p)
-	err := rd.readFull(rd.tmp[:8])
-	if err != nil {
-		if err == io.EOF {
-			err = io.ErrUnexpectedEOF
-		}
-		return nil, err
-	}
-
-	switch {
-	default:
-		return nil, errNotObject
-
-	case bytes.Equal(rd.tmp[:8], archiveHeader):
-		if err := rd.parseArchive(); err != nil {
-			return nil, err
-		}
-	case bytes.Equal(rd.tmp[:8], goobjHeader):
-		if err := rd.parseObject(goobjHeader); err != nil {
-			return nil, err
-		}
-	}
-
-	return p, nil
-}
-
-// trimSpace removes trailing spaces from b and returns the corresponding string.
-// This effectively parses the form used in archive headers.
-func trimSpace(b []byte) string {
-	return string(bytes.TrimRight(b, " "))
-}
-
-// parseArchive parses a Unix archive of Go object files.
-// TODO(rsc): Need to skip non-Go object files.
-// TODO(rsc): Maybe record table of contents in r.p so that
-// linker can avoid having code to parse archives too.
-func (r *objReader) parseArchive() error {
-	for r.offset < r.limit {
-		if err := r.readFull(r.tmp[:60]); err != nil {
-			return err
-		}
-		data := r.tmp[:60]
-
-		// Each file is preceded by this text header (slice indices in first column):
-		//	 0:16	name
-		//	16:28 date
-		//	28:34 uid
-		//	34:40 gid
-		//	40:48 mode
-		//	48:58 size
-		//	58:60 magic - `\n
-		// We only care about name, size, and magic.
-		// The fields are space-padded on the right.
-		// The size is in decimal.
-		// The file data - size bytes - follows the header.
-		// Headers are 2-byte aligned, so if size is odd, an extra padding
-		// byte sits between the file data and the next header.
-		// The file data that follows is padded to an even number of bytes:
-		// if size is odd, an extra padding byte is inserted betw the next header.
-		if len(data) < 60 {
-			return errTruncatedArchive
-		}
-		if !bytes.Equal(data[58:60], archiveMagic) {
-			return errCorruptArchive
-		}
-		name := trimSpace(data[0:16])
-		size, err := strconv.ParseInt(trimSpace(data[48:58]), 10, 64)
-		if err != nil {
-			return errCorruptArchive
-		}
-		data = data[60:]
-		fsize := size + size&1
-		if fsize < 0 || fsize < size {
-			return errCorruptArchive
-		}
-		switch name {
-		case "__.SYMDEF", "__.GOSYMDEF", "__.PKGDEF":
-			r.skip(size)
-		default:
-			oldLimit := r.limit
-			r.limit = r.offset + size
-			if err := r.parseObject(nil); err != nil {
-				return fmt.Errorf("parsing archive member %q: %v", name, err)
-			}
-			r.skip(r.limit - r.offset)
-			r.limit = oldLimit
-		}
-		if size&1 != 0 {
-			r.skip(1)
-		}
-	}
-	return nil
-}
-
-// parseObject parses a single Go object file.
-// The prefix is the bytes already read from the file,
-// typically in order to detect that this is an object file.
-// The object file consists of a textual header ending in "\n!\n"
-// and then the part we want to parse begins.
-// The format of that part is defined in a comment at the top
-// of src/liblink/objfile.c.
-func (r *objReader) parseObject(prefix []byte) error {
-	// TODO(rsc): Maybe use prefix and the initial input to
-	// record the header line from the file, which would
-	// give the architecture and other version information.
-
-	r.p.MaxVersion++
-	var c1, c2, c3 byte
-	for {
-		c1, c2, c3 = c2, c3, r.readByte()
-		if c3 == 0 { // NUL or EOF, either is bad
-			return errCorruptObject
-		}
-		if c1 == '\n' && c2 == '!' && c3 == '\n' {
-			break
-		}
-	}
-
-	r.readFull(r.tmp[:8])
-	if !bytes.Equal(r.tmp[:8], []byte("\x00\x00go13ld")) {
-		return r.error(errCorruptObject)
-	}
-
-	b := r.readByte()
-	if b != 1 {
-		return r.error(errCorruptObject)
-	}
-
-	// Direct package dependencies.
-	for {
-		s := r.readString()
-		if s == "" {
-			break
-		}
-		r.p.Imports = append(r.p.Imports, s)
-	}
-
-	// Symbols.
-	for {
-		if b := r.readByte(); b != 0xfe {
-			if b != 0xff {
-				return r.error(errCorruptObject)
-			}
-			break
-		}
-
-		typ := r.readInt()
-		s := &Sym{SymID: r.readSymID()}
-		r.p.Syms = append(r.p.Syms, s)
-		s.Kind = SymKind(typ)
-		flags := r.readInt()
-		s.DupOK = flags&1 != 0
-		s.Size = r.readInt()
-		s.Type = r.readSymID()
-		s.Data = r.readData()
-		s.Reloc = make([]Reloc, r.readInt())
-		for i := range s.Reloc {
-			rel := &s.Reloc[i]
-			rel.Offset = r.readInt()
-			rel.Size = r.readInt()
-			rel.Type = r.readInt()
-			rel.Add = r.readInt()
-			r.readInt() // Xadd - ignored
-			rel.Sym = r.readSymID()
-			r.readSymID() // Xsym - ignored
-		}
-
-		if s.Kind == STEXT {
-			f := new(Func)
-			s.Func = f
-			f.Args = r.readInt()
-			f.Frame = r.readInt()
-			flags := r.readInt()
-			f.Leaf = flags&1 != 0
-			f.NoSplit = r.readInt() != 0
-			f.Var = make([]Var, r.readInt())
-			for i := range f.Var {
-				v := &f.Var[i]
-				v.Name = r.readSymID().Name
-				v.Offset = r.readInt()
-				v.Kind = r.readInt()
-				v.Type = r.readSymID()
-			}
-
-			f.PCSP = r.readData()
-			f.PCFile = r.readData()
-			f.PCLine = r.readData()
-			f.PCData = make([]Data, r.readInt())
-			for i := range f.PCData {
-				f.PCData[i] = r.readData()
-			}
-			f.FuncData = make([]FuncData, r.readInt())
-			for i := range f.FuncData {
-				f.FuncData[i].Sym = r.readSymID()
-			}
-			for i := range f.FuncData {
-				f.FuncData[i].Offset = int64(r.readInt()) // TODO
-			}
-			f.File = make([]string, r.readInt())
-			for i := range f.File {
-				f.File[i] = r.readSymID().Name
-			}
-		}
-	}
-
-	r.readFull(r.tmp[:7])
-	if !bytes.Equal(r.tmp[:7], []byte("\xffgo13ld")) {
-		return r.error(errCorruptObject)
-	}
-
-	return nil
-}
diff --git a/src/debug/goobj/read_test.go b/src/debug/goobj/read_test.go
deleted file mode 100644
index cc991e5d9..000000000
--- a/src/debug/goobj/read_test.go
+++ /dev/null
@@ -1,28 +0,0 @@
-// 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.
-
-package goobj
-
-import "testing"
-
-var importPathToPrefixTests = []struct {
-	in  string
-	out string
-}{
-	{"runtime", "runtime"},
-	{"sync/atomic", "sync/atomic"},
-	{"golang.org/x/tools/godoc", "golang.org/x/tools/godoc"},
-	{"foo.bar/baz.quux", "foo.bar/baz%2equux"},
-	{"", ""},
-	{"%foo%bar", "%25foo%25bar"},
-	{"\x01\x00\x7F☺", "%01%00%7f%e2%98%ba"},
-}
-
-func TestImportPathToPrefix(t *testing.T) {
-	for _, tt := range importPathToPrefixTests {
-		if out := importPathToPrefix(tt.in); out != tt.out {
-			t.Errorf("importPathToPrefix(%q) = %q, want %q", tt.in, out, tt.out)
-		}
-	}
-}