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authorWim <wim@42.be>2018-08-06 21:47:05 +0200
committerWim <wim@42.be>2018-08-06 21:47:05 +0200
commit51062863a5c34d81e296cf15c61140911037cf3b (patch)
tree9b5e044672486326c7a0ca8fb26430f37bf4d83c /vendor/github.com/google/gops/internal/goobj
parent4fb4b7aa6c02a54db8ad8dd98e4d321396926c0d (diff)
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Use mod vendor for vendored directory (backwards compatible)
Diffstat (limited to 'vendor/github.com/google/gops/internal/goobj')
-rw-r--r--vendor/github.com/google/gops/internal/goobj/read.go714
1 files changed, 0 insertions, 714 deletions
diff --git a/vendor/github.com/google/gops/internal/goobj/read.go b/vendor/github.com/google/gops/internal/goobj/read.go
deleted file mode 100644
index 8a6f13bc..00000000
--- a/vendor/github.com/google/gops/internal/goobj/read.go
+++ /dev/null
@@ -1,714 +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"
-
- "github.com/google/gops/internal/obj"
-)
-
-// 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 (
- // readonly, executable
- STEXT = SymKind(obj.STEXT)
- SELFRXSECT = SymKind(obj.SELFRXSECT)
-
- // readonly, non-executable
- STYPE = SymKind(obj.STYPE)
- SSTRING = SymKind(obj.SSTRING)
- SGOSTRING = SymKind(obj.SGOSTRING)
- SGOFUNC = SymKind(obj.SGOFUNC)
- SRODATA = SymKind(obj.SRODATA)
- SFUNCTAB = SymKind(obj.SFUNCTAB)
- STYPELINK = SymKind(obj.STYPELINK)
- SITABLINK = SymKind(obj.SITABLINK)
- SSYMTAB = SymKind(obj.SSYMTAB) // TODO: move to unmapped section
- SPCLNTAB = SymKind(obj.SPCLNTAB)
- SELFROSECT = SymKind(obj.SELFROSECT)
-
- // writable, non-executable
- SMACHOPLT = SymKind(obj.SMACHOPLT)
- SELFSECT = SymKind(obj.SELFSECT)
- SMACHO = SymKind(obj.SMACHO) // Mach-O __nl_symbol_ptr
- SMACHOGOT = SymKind(obj.SMACHOGOT)
- SWINDOWS = SymKind(obj.SWINDOWS)
- SELFGOT = SymKind(obj.SELFGOT)
- SNOPTRDATA = SymKind(obj.SNOPTRDATA)
- SINITARR = SymKind(obj.SINITARR)
- SDATA = SymKind(obj.SDATA)
- SBSS = SymKind(obj.SBSS)
- SNOPTRBSS = SymKind(obj.SNOPTRBSS)
- STLSBSS = SymKind(obj.STLSBSS)
-
- // not mapped
- SXREF = SymKind(obj.SXREF)
- SMACHOSYMSTR = SymKind(obj.SMACHOSYMSTR)
- SMACHOSYMTAB = SymKind(obj.SMACHOSYMTAB)
- SMACHOINDIRECTPLT = SymKind(obj.SMACHOINDIRECTPLT)
- SMACHOINDIRECTGOT = SymKind(obj.SMACHOINDIRECTGOT)
- SFILE = SymKind(obj.SFILE)
- SFILEPATH = SymKind(obj.SFILEPATH)
- SCONST = SymKind(obj.SCONST)
- SDYNIMPORT = SymKind(obj.SDYNIMPORT)
- SHOSTOBJ = SymKind(obj.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",
- SITABLINK: "SITABLINK",
- 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 containing Sym
- // 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 obj.RelocType
-}
-
-// 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
- SymRefs []SymID // list of symbol names and versions referred to by this pack
- Syms []*Sym // symbols defined by this package
- MaxVersion int // maximum Version in any SymID in Syms
- Arch string // architecture
-}
-
-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")
- errCorruptObject = errors.New("corrupt 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
- dataOffset int64
- limit int64
- tmp [256]byte
- 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, io.SeekCurrent)
- r.limit, _ = f.Seek(0, io.SeekEnd)
- f.Seek(r.offset, io.SeekStart)
- 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 {
- i := r.readInt()
- return r.p.SymRefs[i]
-}
-
-func (r *objReader) readRef() {
- 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
- }
- r.p.SymRefs = append(r.p.SymRefs, SymID{name, vers})
-}
-
-// readData reads a data reference from the input file.
-func (r *objReader) readData() Data {
- n := r.readInt()
- d := Data{Offset: r.dataOffset, Size: int64(n)}
- r.dataOffset += 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, io.SeekStart)
- 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 "__.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 {
- r.p.MaxVersion++
- h := make([]byte, 0, 256)
- h = append(h, prefix...)
- var c1, c2, c3 byte
- for {
- c1, c2, c3 = c2, c3, r.readByte()
- h = append(h, c3)
- // The new export format can contain 0 bytes.
- // Don't consider them errors, only look for r.err != nil.
- if r.err != nil {
- return errCorruptObject
- }
- if c1 == '\n' && c2 == '!' && c3 == '\n' {
- break
- }
- }
-
- hs := strings.Fields(string(h))
- if len(hs) >= 4 {
- r.p.Arch = hs[3]
- }
- // TODO: extract OS + build ID if/when we need it
-
- r.readFull(r.tmp[:8])
- if !bytes.Equal(r.tmp[:8], []byte("\x00\x00go17ld")) {
- 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)
- }
-
- r.p.SymRefs = []SymID{{"", 0}}
- for {
- if b := r.readByte(); b != 0xfe {
- if b != 0xff {
- return r.error(errCorruptObject)
- }
- break
- }
-
- r.readRef()
- }
-
- dataLength := r.readInt()
- r.readInt() // n relocations - ignore
- r.readInt() // n pcdata - ignore
- r.readInt() // n autom - ignore
- r.readInt() // n funcdata - ignore
- r.readInt() // n files - ignore
-
- r.dataOffset = r.offset
- r.skip(int64(dataLength))
-
- // 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 = obj.RelocType(r.readInt())
- rel.Add = r.readInt()
- rel.Sym = r.readSymID()
- }
-
- 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("\xffgo17ld")) {
- return r.error(errCorruptObject)
- }
-
- return nil
-}
-
-func (r *Reloc) String(insnOffset uint64) string {
- delta := r.Offset - int(insnOffset)
- s := fmt.Sprintf("[%d:%d]%s", delta, delta+r.Size, r.Type)
- if r.Sym.Name != "" {
- if r.Add != 0 {
- return fmt.Sprintf("%s:%s+%d", s, r.Sym.Name, r.Add)
- }
- return fmt.Sprintf("%s:%s", s, r.Sym.Name)
- }
- if r.Add != 0 {
- return fmt.Sprintf("%s:%d", s, r.Add)
- }
- return s
-}