Add gops agent

vendor/github.com/google/gops/internal/objfile/disasm.go

@@ -0,0 +1,283 @@
+// Copyright 2014 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 objfile
+
+import (
+	"bufio"
+	"debug/gosym"
+	"encoding/binary"
+	"fmt"
+	"io"
+	"regexp"
+	"sort"
+	"strings"
+	"text/tabwriter"
+
+	"golang.org/x/arch/arm/armasm"
+	"golang.org/x/arch/ppc64/ppc64asm"
+	"golang.org/x/arch/x86/x86asm"
+)
+
+// Disasm is a disassembler for a given File.
+type Disasm struct {
+	syms      []Sym            //symbols in file, sorted by address
+	pcln      Liner            // pcln table
+	text      []byte           // bytes of text segment (actual instructions)
+	textStart uint64           // start PC of text
+	textEnd   uint64           // end PC of text
+	goarch    string           // GOARCH string
+	disasm    disasmFunc       // disassembler function for goarch
+	byteOrder binary.ByteOrder // byte order for goarch
+}
+
+// Disasm returns a disassembler for the file f.
+func (f *File) Disasm() (*Disasm, error) {
+	syms, err := f.Symbols()
+	if err != nil {
+		return nil, err
+	}
+
+	pcln, err := f.PCLineTable()
+	if err != nil {
+		return nil, err
+	}
+
+	textStart, textBytes, err := f.Text()
+	if err != nil {
+		return nil, err
+	}
+
+	goarch := f.GOARCH()
+	disasm := disasms[goarch]
+	byteOrder := byteOrders[goarch]
+	if disasm == nil || byteOrder == nil {
+		return nil, fmt.Errorf("unsupported architecture")
+	}
+
+	// Filter out section symbols, overwriting syms in place.
+	keep := syms[:0]
+	for _, sym := range syms {
+		switch sym.Name {
+		case "runtime.text", "text", "_text", "runtime.etext", "etext", "_etext":
+			// drop
+		default:
+			keep = append(keep, sym)
+		}
+	}
+	syms = keep
+	d := &Disasm{
+		syms:      syms,
+		pcln:      pcln,
+		text:      textBytes,
+		textStart: textStart,
+		textEnd:   textStart + uint64(len(textBytes)),
+		goarch:    goarch,
+		disasm:    disasm,
+		byteOrder: byteOrder,
+	}
+
+	return d, nil
+}
+
+// lookup finds the symbol name containing addr.
+func (d *Disasm) lookup(addr uint64) (name string, base uint64) {
+	i := sort.Search(len(d.syms), func(i int) bool { return addr < d.syms[i].Addr })
+	if i > 0 {
+		s := d.syms[i-1]
+		if s.Addr != 0 && s.Addr <= addr && addr < s.Addr+uint64(s.Size) {
+			return s.Name, s.Addr
+		}
+	}
+	return "", 0
+}
+
+// base returns the final element in the path.
+// It works on both Windows and Unix paths,
+// regardless of host operating system.
+func base(path string) string {
+	path = path[strings.LastIndex(path, "/")+1:]
+	path = path[strings.LastIndex(path, `\`)+1:]
+	return path
+}
+
+// Print prints a disassembly of the file to w.
+// If filter is non-nil, the disassembly only includes functions with names matching filter.
+// The disassembly only includes functions that overlap the range [start, end).
+func (d *Disasm) Print(w io.Writer, filter *regexp.Regexp, start, end uint64) {
+	if start < d.textStart {
+		start = d.textStart
+	}
+	if end > d.textEnd {
+		end = d.textEnd
+	}
+	printed := false
+	bw := bufio.NewWriter(w)
+	for _, sym := range d.syms {
+		symStart := sym.Addr
+		symEnd := sym.Addr + uint64(sym.Size)
+		relocs := sym.Relocs
+		if sym.Code != 'T' && sym.Code != 't' ||
+			symStart < d.textStart ||
+			symEnd <= start || end <= symStart ||
+			filter != nil && !filter.MatchString(sym.Name) {
+			continue
+		}
+		if printed {
+			fmt.Fprintf(bw, "\n")
+		}
+		printed = true
+
+		file, _, _ := d.pcln.PCToLine(sym.Addr)
+		fmt.Fprintf(bw, "TEXT %s(SB) %s\n", sym.Name, file)
+
+		tw := tabwriter.NewWriter(bw, 1, 8, 1, '\t', 0)
+		if symEnd > end {
+			symEnd = end
+		}
+		code := d.text[:end-d.textStart]
+		d.Decode(symStart, symEnd, relocs, func(pc, size uint64, file string, line int, text string) {
+			i := pc - d.textStart
+			fmt.Fprintf(tw, "\t%s:%d\t%#x\t", base(file), line, pc)
+			if size%4 != 0 || d.goarch == "386" || d.goarch == "amd64" {
+				// Print instruction as bytes.
+				fmt.Fprintf(tw, "%x", code[i:i+size])
+			} else {
+				// Print instruction as 32-bit words.
+				for j := uint64(0); j < size; j += 4 {
+					if j > 0 {
+						fmt.Fprintf(tw, " ")
+					}
+					fmt.Fprintf(tw, "%08x", d.byteOrder.Uint32(code[i+j:]))
+				}
+			}
+			fmt.Fprintf(tw, "\t%s\n", text)
+		})
+		tw.Flush()
+	}
+	bw.Flush()
+}
+
+// Decode disassembles the text segment range [start, end), calling f for each instruction.
+func (d *Disasm) Decode(start, end uint64, relocs []Reloc, f func(pc, size uint64, file string, line int, text string)) {
+	if start < d.textStart {
+		start = d.textStart
+	}
+	if end > d.textEnd {
+		end = d.textEnd
+	}
+	code := d.text[:end-d.textStart]
+	lookup := d.lookup
+	for pc := start; pc < end; {
+		i := pc - d.textStart
+		text, size := d.disasm(code[i:], pc, lookup, d.byteOrder)
+		file, line, _ := d.pcln.PCToLine(pc)
+		text += "\t"
+		first := true
+		for len(relocs) > 0 && relocs[0].Addr < i+uint64(size) {
+			if first {
+				first = false
+			} else {
+				text += " "
+			}
+			text += relocs[0].Stringer.String(pc - start)
+			relocs = relocs[1:]
+		}
+		f(pc, uint64(size), file, line, text)
+		pc += uint64(size)
+	}
+}
+
+type lookupFunc func(addr uint64) (sym string, base uint64)
+type disasmFunc func(code []byte, pc uint64, lookup lookupFunc, ord binary.ByteOrder) (text string, size int)
+
+func disasm_386(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder) (string, int) {
+	return disasm_x86(code, pc, lookup, 32)
+}
+
+func disasm_amd64(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder) (string, int) {
+	return disasm_x86(code, pc, lookup, 64)
+}
+
+func disasm_x86(code []byte, pc uint64, lookup lookupFunc, arch int) (string, int) {
+	inst, err := x86asm.Decode(code, 64)
+	var text string
+	size := inst.Len
+	if err != nil || size == 0 || inst.Op == 0 {
+		size = 1
+		text = "?"
+	} else {
+		text = x86asm.GoSyntax(inst, pc, lookup)
+	}
+	return text, size
+}
+
+type textReader struct {
+	code []byte
+	pc   uint64
+}
+
+func (r textReader) ReadAt(data []byte, off int64) (n int, err error) {
+	if off < 0 || uint64(off) < r.pc {
+		return 0, io.EOF
+	}
+	d := uint64(off) - r.pc
+	if d >= uint64(len(r.code)) {
+		return 0, io.EOF
+	}
+	n = copy(data, r.code[d:])
+	if n < len(data) {
+		err = io.ErrUnexpectedEOF
+	}
+	return
+}
+
+func disasm_arm(code []byte, pc uint64, lookup lookupFunc, _ binary.ByteOrder) (string, int) {
+	inst, err := armasm.Decode(code, armasm.ModeARM)
+	var text string
+	size := inst.Len
+	if err != nil || size == 0 || inst.Op == 0 {
+		size = 4
+		text = "?"
+	} else {
+		text = armasm.GoSyntax(inst, pc, lookup, textReader{code, pc})
+	}
+	return text, size
+}
+
+func disasm_ppc64(code []byte, pc uint64, lookup lookupFunc, byteOrder binary.ByteOrder) (string, int) {
+	inst, err := ppc64asm.Decode(code, byteOrder)
+	var text string
+	size := inst.Len
+	if err != nil || size == 0 || inst.Op == 0 {
+		size = 4
+		text = "?"
+	} else {
+		text = ppc64asm.GoSyntax(inst, pc, lookup)
+	}
+	return text, size
+}
+
+var disasms = map[string]disasmFunc{
+	"386":     disasm_386,
+	"amd64":   disasm_amd64,
+	"arm":     disasm_arm,
+	"ppc64":   disasm_ppc64,
+	"ppc64le": disasm_ppc64,
+}
+
+var byteOrders = map[string]binary.ByteOrder{
+	"386":     binary.LittleEndian,
+	"amd64":   binary.LittleEndian,
+	"arm":     binary.LittleEndian,
+	"ppc64":   binary.BigEndian,
+	"ppc64le": binary.LittleEndian,
+	"s390x":   binary.BigEndian,
+}
+
+type Liner interface {
+	// Given a pc, returns the corresponding file, line, and function data.
+	// If unknown, returns "",0,nil.
+	PCToLine(uint64) (string, int, *gosym.Func)
+}

vendor/github.com/google/gops/internal/objfile/elf.go

@@ -0,0 +1,124 @@
+// 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.
+
+// Parsing of ELF executables (Linux, FreeBSD, and so on).
+
+package objfile
+
+import (
+	"debug/dwarf"
+	"debug/elf"
+	"encoding/binary"
+	"fmt"
+	"os"
+)
+
+type elfFile struct {
+	elf *elf.File
+}
+
+func openElf(r *os.File) (rawFile, error) {
+	f, err := elf.NewFile(r)
+	if err != nil {
+		return nil, err
+	}
+	return &elfFile{f}, nil
+}
+
+func (f *elfFile) symbols() ([]Sym, error) {
+	elfSyms, err := f.elf.Symbols()
+	if err != nil {
+		return nil, err
+	}
+
+	var syms []Sym
+	for _, s := range elfSyms {
+		sym := Sym{Addr: s.Value, Name: s.Name, Size: int64(s.Size), Code: '?'}
+		switch s.Section {
+		case elf.SHN_UNDEF:
+			sym.Code = 'U'
+		case elf.SHN_COMMON:
+			sym.Code = 'B'
+		default:
+			i := int(s.Section)
+			if i < 0 || i >= len(f.elf.Sections) {
+				break
+			}
+			sect := f.elf.Sections[i]
+			switch sect.Flags & (elf.SHF_WRITE | elf.SHF_ALLOC | elf.SHF_EXECINSTR) {
+			case elf.SHF_ALLOC | elf.SHF_EXECINSTR:
+				sym.Code = 'T'
+			case elf.SHF_ALLOC:
+				sym.Code = 'R'
+			case elf.SHF_ALLOC | elf.SHF_WRITE:
+				sym.Code = 'D'
+			}
+		}
+		if elf.ST_BIND(s.Info) == elf.STB_LOCAL {
+			sym.Code += 'a' - 'A'
+		}
+		syms = append(syms, sym)
+	}
+
+	return syms, nil
+}
+
+func (f *elfFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	if sect := f.elf.Section(".text"); sect != nil {
+		textStart = sect.Addr
+	}
+	if sect := f.elf.Section(".gosymtab"); sect != nil {
+		if symtab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if sect := f.elf.Section(".gopclntab"); sect != nil {
+		if pclntab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
+}
+
+func (f *elfFile) text() (textStart uint64, text []byte, err error) {
+	sect := f.elf.Section(".text")
+	if sect == nil {
+		return 0, nil, fmt.Errorf("text section not found")
+	}
+	textStart = sect.Addr
+	text, err = sect.Data()
+	return
+}
+
+func (f *elfFile) goarch() string {
+	switch f.elf.Machine {
+	case elf.EM_386:
+		return "386"
+	case elf.EM_X86_64:
+		return "amd64"
+	case elf.EM_ARM:
+		return "arm"
+	case elf.EM_PPC64:
+		if f.elf.ByteOrder == binary.LittleEndian {
+			return "ppc64le"
+		}
+		return "ppc64"
+	case elf.EM_S390:
+		return "s390x"
+	}
+	return ""
+}
+
+func (f *elfFile) loadAddress() (uint64, error) {
+	for _, p := range f.elf.Progs {
+		if p.Type == elf.PT_LOAD {
+			return p.Vaddr, nil
+		}
+	}
+	return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *elfFile) dwarf() (*dwarf.Data, error) {
+	return f.elf.DWARF()
+}

vendor/github.com/google/gops/internal/objfile/goobj.go

@@ -0,0 +1,160 @@
+// 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.
+
+// Parsing of Go intermediate object files and archives.
+
+package objfile
+
+/*
+
+
+import (
+	"debug/dwarf"
+	"debug/gosym"
+	"errors"
+	"fmt"
+	"os"
+
+	"github.com/google/gops/internal/sys"
+
+	"github.com/google/gops/internal/goobj"
+)
+
+type goobjFile struct {
+	goobj *goobj.Package
+	f     *os.File // the underlying .o or .a file
+}
+
+func openGoobj(r *os.File) (rawFile, error) {
+	f, err := goobj.Parse(r, `""`)
+	if err != nil {
+		return nil, err
+	}
+	return &goobjFile{goobj: f, f: r}, nil
+}
+
+func goobjName(id goobj.SymID) string {
+	if id.Version == 0 {
+		return id.Name
+	}
+	return fmt.Sprintf("%s<%d>", id.Name, id.Version)
+}
+
+func (f *goobjFile) symbols() ([]Sym, error) {
+	seen := make(map[goobj.SymID]bool)
+
+	var syms []Sym
+	for _, s := range f.goobj.Syms {
+		seen[s.SymID] = true
+		sym := Sym{Addr: uint64(s.Data.Offset), Name: goobjName(s.SymID), Size: int64(s.Size), Type: s.Type.Name, Code: '?'}
+		switch s.Kind {
+		case goobj.STEXT, goobj.SELFRXSECT:
+			sym.Code = 'T'
+		case goobj.STYPE, goobj.SSTRING, goobj.SGOSTRING, goobj.SGOFUNC, goobj.SRODATA, goobj.SFUNCTAB, goobj.STYPELINK, goobj.SITABLINK, goobj.SSYMTAB, goobj.SPCLNTAB, goobj.SELFROSECT:
+			sym.Code = 'R'
+		case goobj.SMACHOPLT, goobj.SELFSECT, goobj.SMACHO, goobj.SMACHOGOT, goobj.SNOPTRDATA, goobj.SINITARR, goobj.SDATA, goobj.SWINDOWS:
+			sym.Code = 'D'
+		case goobj.SBSS, goobj.SNOPTRBSS, goobj.STLSBSS:
+			sym.Code = 'B'
+		case goobj.SXREF, goobj.SMACHOSYMSTR, goobj.SMACHOSYMTAB, goobj.SMACHOINDIRECTPLT, goobj.SMACHOINDIRECTGOT, goobj.SFILE, goobj.SFILEPATH, goobj.SCONST, goobj.SDYNIMPORT, goobj.SHOSTOBJ:
+			sym.Code = 'X' // should not see
+		}
+		if s.Version != 0 {
+			sym.Code += 'a' - 'A'
+		}
+		for i, r := range s.Reloc {
+			sym.Relocs = append(sym.Relocs, Reloc{Addr: uint64(s.Data.Offset) + uint64(r.Offset), Size: uint64(r.Size), Stringer: &s.Reloc[i]})
+		}
+		syms = append(syms, sym)
+	}
+
+	for _, s := range f.goobj.Syms {
+		for _, r := range s.Reloc {
+			if !seen[r.Sym] {
+				seen[r.Sym] = true
+				sym := Sym{Name: goobjName(r.Sym), Code: 'U'}
+				if s.Version != 0 {
+					// should not happen but handle anyway
+					sym.Code = 'u'
+				}
+				syms = append(syms, sym)
+			}
+		}
+	}
+
+	return syms, nil
+}
+
+func (f *goobjFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	// Should never be called.  We implement Liner below, callers
+	// should use that instead.
+	return 0, nil, nil, fmt.Errorf("pcln not available in go object file")
+}
+
+// Find returns the file name, line, and function data for the given pc.
+// Returns "",0,nil if unknown.
+// This function implements the Liner interface in preference to pcln() above.
+func (f *goobjFile) PCToLine(pc uint64) (string, int, *gosym.Func) {
+	// TODO: this is really inefficient.  Binary search?  Memoize last result?
+	var arch *sys.Arch
+	for _, a := range sys.Archs {
+		if a.Name == f.goobj.Arch {
+			arch = a
+			break
+		}
+	}
+	if arch == nil {
+		return "", 0, nil
+	}
+	for _, s := range f.goobj.Syms {
+		if pc < uint64(s.Data.Offset) || pc >= uint64(s.Data.Offset+s.Data.Size) {
+			continue
+		}
+		if s.Func == nil {
+			return "", 0, nil
+		}
+		pcfile := make([]byte, s.Func.PCFile.Size)
+		_, err := f.f.ReadAt(pcfile, s.Func.PCFile.Offset)
+		if err != nil {
+			return "", 0, nil
+		}
+		fileID := gosym.PCValue(pcfile, pc-uint64(s.Data.Offset), arch.MinLC)
+		fileName := s.Func.File[fileID]
+		pcline := make([]byte, s.Func.PCLine.Size)
+		_, err = f.f.ReadAt(pcline, s.Func.PCLine.Offset)
+		if err != nil {
+			return "", 0, nil
+		}
+		line := gosym.PCValue(pcline, pc-uint64(s.Data.Offset), arch.MinLC)
+		// Note: we provide only the name in the Func structure.
+		// We could provide more if needed.
+		return fileName, line, &gosym.Func{Sym: &gosym.Sym{Name: s.Name}}
+	}
+	return "", 0, nil
+}
+
+// We treat the whole object file as the text section.
+func (f *goobjFile) text() (textStart uint64, text []byte, err error) {
+	var info os.FileInfo
+	info, err = f.f.Stat()
+	if err != nil {
+		return
+	}
+	text = make([]byte, info.Size())
+	_, err = f.f.ReadAt(text, 0)
+	return
+}
+
+func (f *goobjFile) goarch() string {
+	return f.goobj.Arch
+}
+
+func (f *goobjFile) loadAddress() (uint64, error) {
+	return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *goobjFile) dwarf() (*dwarf.Data, error) {
+	return nil, errors.New("no DWARF data in go object file")
+}
+*/

vendor/github.com/google/gops/internal/objfile/macho.go

@@ -0,0 +1,134 @@
+// 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.
+
+// Parsing of Mach-O executables (OS X).
+
+package objfile
+
+import (
+	"debug/dwarf"
+	"debug/macho"
+	"fmt"
+	"os"
+	"sort"
+)
+
+const stabTypeMask = 0xe0
+
+type machoFile struct {
+	macho *macho.File
+}
+
+func openMacho(r *os.File) (rawFile, error) {
+	f, err := macho.NewFile(r)
+	if err != nil {
+		return nil, err
+	}
+	return &machoFile{f}, nil
+}
+
+func (f *machoFile) symbols() ([]Sym, error) {
+	if f.macho.Symtab == nil {
+		return nil, fmt.Errorf("missing symbol table")
+	}
+
+	// Build sorted list of addresses of all symbols.
+	// We infer the size of a symbol by looking at where the next symbol begins.
+	var addrs []uint64
+	for _, s := range f.macho.Symtab.Syms {
+		// Skip stab debug info.
+		if s.Type&stabTypeMask == 0 {
+			addrs = append(addrs, s.Value)
+		}
+	}
+	sort.Sort(uint64s(addrs))
+
+	var syms []Sym
+	for _, s := range f.macho.Symtab.Syms {
+		if s.Type&stabTypeMask != 0 {
+			// Skip stab debug info.
+			continue
+		}
+		sym := Sym{Name: s.Name, Addr: s.Value, Code: '?'}
+		i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value })
+		if i < len(addrs) {
+			sym.Size = int64(addrs[i] - s.Value)
+		}
+		if s.Sect == 0 {
+			sym.Code = 'U'
+		} else if int(s.Sect) <= len(f.macho.Sections) {
+			sect := f.macho.Sections[s.Sect-1]
+			switch sect.Seg {
+			case "__TEXT":
+				sym.Code = 'R'
+			case "__DATA":
+				sym.Code = 'D'
+			}
+			switch sect.Seg + " " + sect.Name {
+			case "__TEXT __text":
+				sym.Code = 'T'
+			case "__DATA __bss", "__DATA __noptrbss":
+				sym.Code = 'B'
+			}
+		}
+		syms = append(syms, sym)
+	}
+
+	return syms, nil
+}
+
+func (f *machoFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	if sect := f.macho.Section("__text"); sect != nil {
+		textStart = sect.Addr
+	}
+	if sect := f.macho.Section("__gosymtab"); sect != nil {
+		if symtab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if sect := f.macho.Section("__gopclntab"); sect != nil {
+		if pclntab, err = sect.Data(); err != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
+}
+
+func (f *machoFile) text() (textStart uint64, text []byte, err error) {
+	sect := f.macho.Section("__text")
+	if sect == nil {
+		return 0, nil, fmt.Errorf("text section not found")
+	}
+	textStart = sect.Addr
+	text, err = sect.Data()
+	return
+}
+
+func (f *machoFile) goarch() string {
+	switch f.macho.Cpu {
+	case macho.Cpu386:
+		return "386"
+	case macho.CpuAmd64:
+		return "amd64"
+	case macho.CpuArm:
+		return "arm"
+	case macho.CpuPpc64:
+		return "ppc64"
+	}
+	return ""
+}
+
+type uint64s []uint64
+
+func (x uint64s) Len() int           { return len(x) }
+func (x uint64s) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+func (x uint64s) Less(i, j int) bool { return x[i] < x[j] }
+
+func (f *machoFile) loadAddress() (uint64, error) {
+	return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *machoFile) dwarf() (*dwarf.Data, error) {
+	return f.macho.DWARF()
+}

vendor/github.com/google/gops/internal/objfile/objfile.go

@@ -0,0 +1,129 @@
+// Copyright 2014 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 objfile implements portable access to OS-specific executable files.
+package objfile
+
+import (
+	"debug/dwarf"
+	"debug/gosym"
+	"fmt"
+	"os"
+	"sort"
+)
+
+type rawFile interface {
+	symbols() (syms []Sym, err error)
+	pcln() (textStart uint64, symtab, pclntab []byte, err error)
+	text() (textStart uint64, text []byte, err error)
+	goarch() string
+	loadAddress() (uint64, error)
+	dwarf() (*dwarf.Data, error)
+}
+
+// A File is an opened executable file.
+type File struct {
+	r   *os.File
+	raw rawFile
+}
+
+// A Sym is a symbol defined in an executable file.
+type Sym struct {
+	Name   string  // symbol name
+	Addr   uint64  // virtual address of symbol
+	Size   int64   // size in bytes
+	Code   rune    // nm code (T for text, D for data, and so on)
+	Type   string  // XXX?
+	Relocs []Reloc // in increasing Addr order
+}
+
+type Reloc struct {
+	Addr     uint64 // Address of first byte that reloc applies to.
+	Size     uint64 // Number of bytes
+	Stringer RelocStringer
+}
+
+type RelocStringer interface {
+	// insnOffset is the offset of the instruction containing the relocation
+	// from the start of the symbol containing the relocation.
+	String(insnOffset uint64) string
+}
+
+var openers = []func(*os.File) (rawFile, error){
+	openElf,
+	// openGoobj, // TODO(jbd): Bring it back when 1.8 is popular.
+	openMacho,
+	openPE,
+	openPlan9,
+}
+
+// Open opens the named file.
+// The caller must call f.Close when the file is no longer needed.
+func Open(name string) (*File, error) {
+	r, err := os.Open(name)
+	if err != nil {
+		return nil, err
+	}
+	for _, try := range openers {
+		if raw, err := try(r); err == nil {
+			return &File{r, raw}, nil
+		}
+	}
+	r.Close()
+	return nil, fmt.Errorf("open %s: unrecognized object file", name)
+}
+
+func (f *File) Close() error {
+	return f.r.Close()
+}
+
+func (f *File) Symbols() ([]Sym, error) {
+	syms, err := f.raw.symbols()
+	if err != nil {
+		return nil, err
+	}
+	sort.Sort(byAddr(syms))
+	return syms, nil
+}
+
+type byAddr []Sym
+
+func (x byAddr) Less(i, j int) bool { return x[i].Addr < x[j].Addr }
+func (x byAddr) Len() int           { return len(x) }
+func (x byAddr) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+
+func (f *File) PCLineTable() (Liner, error) {
+	// If the raw file implements Liner directly, use that.
+	// Currently, only Go intermediate objects and archives (goobj) use this path.
+	if pcln, ok := f.raw.(Liner); ok {
+		return pcln, nil
+	}
+	// Otherwise, read the pcln tables and build a Liner out of that.
+	textStart, symtab, pclntab, err := f.raw.pcln()
+	if err != nil {
+		return nil, err
+	}
+	return gosym.NewTable(symtab, gosym.NewLineTable(pclntab, textStart))
+}
+
+func (f *File) Text() (uint64, []byte, error) {
+	return f.raw.text()
+}
+
+func (f *File) GOARCH() string {
+	return f.raw.goarch()
+}
+
+// LoadAddress returns the expected load address of the file.
+// This differs from the actual load address for a position-independent
+// executable.
+func (f *File) LoadAddress() (uint64, error) {
+	return f.raw.loadAddress()
+}
+
+// DWARF returns DWARF debug data for the file, if any.
+// This is for cmd/pprof to locate cgo functions.
+func (f *File) DWARF() (*dwarf.Data, error) {
+	return f.raw.dwarf()
+}

vendor/github.com/google/gops/internal/objfile/pe.go

@@ -0,0 +1,208 @@
+// 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.
+
+// Parsing of PE executables (Microsoft Windows).
+
+package objfile
+
+import (
+	"debug/dwarf"
+	"debug/pe"
+	"fmt"
+	"os"
+	"sort"
+)
+
+type peFile struct {
+	pe *pe.File
+}
+
+func openPE(r *os.File) (rawFile, error) {
+	f, err := pe.NewFile(r)
+	if err != nil {
+		return nil, err
+	}
+	switch f.OptionalHeader.(type) {
+	case *pe.OptionalHeader32, *pe.OptionalHeader64:
+		// ok
+	default:
+		return nil, fmt.Errorf("unrecognized PE format")
+	}
+	return &peFile{f}, nil
+}
+
+func (f *peFile) symbols() ([]Sym, error) {
+	// Build sorted list of addresses of all symbols.
+	// We infer the size of a symbol by looking at where the next symbol begins.
+	var addrs []uint64
+
+	var imageBase uint64
+	switch oh := f.pe.OptionalHeader.(type) {
+	case *pe.OptionalHeader32:
+		imageBase = uint64(oh.ImageBase)
+	case *pe.OptionalHeader64:
+		imageBase = oh.ImageBase
+	}
+
+	var syms []Sym
+	for _, s := range f.pe.Symbols {
+		const (
+			N_UNDEF = 0  // An undefined (extern) symbol
+			N_ABS   = -1 // An absolute symbol (e_value is a constant, not an address)
+			N_DEBUG = -2 // A debugging symbol
+		)
+		sym := Sym{Name: s.Name, Addr: uint64(s.Value), Code: '?'}
+		switch s.SectionNumber {
+		case N_UNDEF:
+			sym.Code = 'U'
+		case N_ABS:
+			sym.Code = 'C'
+		case N_DEBUG:
+			sym.Code = '?'
+		default:
+			if s.SectionNumber < 0 || len(f.pe.Sections) < int(s.SectionNumber) {
+				return nil, fmt.Errorf("invalid section number in symbol table")
+			}
+			sect := f.pe.Sections[s.SectionNumber-1]
+			const (
+				text  = 0x20
+				data  = 0x40
+				bss   = 0x80
+				permW = 0x80000000
+			)
+			ch := sect.Characteristics
+			switch {
+			case ch&text != 0:
+				sym.Code = 'T'
+			case ch&data != 0:
+				if ch&permW == 0 {
+					sym.Code = 'R'
+				} else {
+					sym.Code = 'D'
+				}
+			case ch&bss != 0:
+				sym.Code = 'B'
+			}
+			sym.Addr += imageBase + uint64(sect.VirtualAddress)
+		}
+		syms = append(syms, sym)
+		addrs = append(addrs, sym.Addr)
+	}
+
+	sort.Sort(uint64s(addrs))
+	for i := range syms {
+		j := sort.Search(len(addrs), func(x int) bool { return addrs[x] > syms[i].Addr })
+		if j < len(addrs) {
+			syms[i].Size = int64(addrs[j] - syms[i].Addr)
+		}
+	}
+
+	return syms, nil
+}
+
+func (f *peFile) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	var imageBase uint64
+	switch oh := f.pe.OptionalHeader.(type) {
+	case *pe.OptionalHeader32:
+		imageBase = uint64(oh.ImageBase)
+	case *pe.OptionalHeader64:
+		imageBase = oh.ImageBase
+	default:
+		return 0, nil, nil, fmt.Errorf("pe file format not recognized")
+	}
+	if sect := f.pe.Section(".text"); sect != nil {
+		textStart = imageBase + uint64(sect.VirtualAddress)
+	}
+	if pclntab, err = loadPETable(f.pe, "runtime.pclntab", "runtime.epclntab"); err != nil {
+		// We didn't find the symbols, so look for the names used in 1.3 and earlier.
+		// TODO: Remove code looking for the old symbols when we no longer care about 1.3.
+		var err2 error
+		if pclntab, err2 = loadPETable(f.pe, "pclntab", "epclntab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if symtab, err = loadPETable(f.pe, "runtime.symtab", "runtime.esymtab"); err != nil {
+		// Same as above.
+		var err2 error
+		if symtab, err2 = loadPETable(f.pe, "symtab", "esymtab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
+}
+
+func (f *peFile) text() (textStart uint64, text []byte, err error) {
+	var imageBase uint64
+	switch oh := f.pe.OptionalHeader.(type) {
+	case *pe.OptionalHeader32:
+		imageBase = uint64(oh.ImageBase)
+	case *pe.OptionalHeader64:
+		imageBase = oh.ImageBase
+	default:
+		return 0, nil, fmt.Errorf("pe file format not recognized")
+	}
+	sect := f.pe.Section(".text")
+	if sect == nil {
+		return 0, nil, fmt.Errorf("text section not found")
+	}
+	textStart = imageBase + uint64(sect.VirtualAddress)
+	text, err = sect.Data()
+	return
+}
+
+func findPESymbol(f *pe.File, name string) (*pe.Symbol, error) {
+	for _, s := range f.Symbols {
+		if s.Name != name {
+			continue
+		}
+		if s.SectionNumber <= 0 {
+			return nil, fmt.Errorf("symbol %s: invalid section number %d", name, s.SectionNumber)
+		}
+		if len(f.Sections) < int(s.SectionNumber) {
+			return nil, fmt.Errorf("symbol %s: section number %d is larger than max %d", name, s.SectionNumber, len(f.Sections))
+		}
+		return s, nil
+	}
+	return nil, fmt.Errorf("no %s symbol found", name)
+}
+
+func loadPETable(f *pe.File, sname, ename string) ([]byte, error) {
+	ssym, err := findPESymbol(f, sname)
+	if err != nil {
+		return nil, err
+	}
+	esym, err := findPESymbol(f, ename)
+	if err != nil {
+		return nil, err
+	}
+	if ssym.SectionNumber != esym.SectionNumber {
+		return nil, fmt.Errorf("%s and %s symbols must be in the same section", sname, ename)
+	}
+	sect := f.Sections[ssym.SectionNumber-1]
+	data, err := sect.Data()
+	if err != nil {
+		return nil, err
+	}
+	return data[ssym.Value:esym.Value], nil
+}
+
+func (f *peFile) goarch() string {
+	// Not sure how to get the info we want from PE header.
+	// Look in symbol table for telltale rt0 symbol.
+	if _, err := findPESymbol(f.pe, "_rt0_386_windows"); err == nil {
+		return "386"
+	}
+	if _, err := findPESymbol(f.pe, "_rt0_amd64_windows"); err == nil {
+		return "amd64"
+	}
+	return ""
+}
+
+func (f *peFile) loadAddress() (uint64, error) {
+	return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *peFile) dwarf() (*dwarf.Data, error) {
+	return f.pe.DWARF()
+}

vendor/github.com/google/gops/internal/objfile/plan9obj.go

@@ -0,0 +1,156 @@
+// Copyright 2014 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.
+
+// Parsing of Plan 9 a.out executables.
+
+package objfile
+
+import (
+	"debug/dwarf"
+	"debug/plan9obj"
+	"errors"
+	"fmt"
+	"os"
+	"sort"
+)
+
+var validSymType = map[rune]bool{
+	'T': true,
+	't': true,
+	'D': true,
+	'd': true,
+	'B': true,
+	'b': true,
+}
+
+type plan9File struct {
+	plan9 *plan9obj.File
+}
+
+func openPlan9(r *os.File) (rawFile, error) {
+	f, err := plan9obj.NewFile(r)
+	if err != nil {
+		return nil, err
+	}
+	return &plan9File{f}, nil
+}
+
+func (f *plan9File) symbols() ([]Sym, error) {
+	plan9Syms, err := f.plan9.Symbols()
+	if err != nil {
+		return nil, err
+	}
+
+	// Build sorted list of addresses of all symbols.
+	// We infer the size of a symbol by looking at where the next symbol begins.
+	var addrs []uint64
+	for _, s := range plan9Syms {
+		if !validSymType[s.Type] {
+			continue
+		}
+		addrs = append(addrs, s.Value)
+	}
+	sort.Sort(uint64s(addrs))
+
+	var syms []Sym
+
+	for _, s := range plan9Syms {
+		if !validSymType[s.Type] {
+			continue
+		}
+		sym := Sym{Addr: s.Value, Name: s.Name, Code: s.Type}
+		i := sort.Search(len(addrs), func(x int) bool { return addrs[x] > s.Value })
+		if i < len(addrs) {
+			sym.Size = int64(addrs[i] - s.Value)
+		}
+		syms = append(syms, sym)
+	}
+
+	return syms, nil
+}
+
+func (f *plan9File) pcln() (textStart uint64, symtab, pclntab []byte, err error) {
+	textStart = f.plan9.LoadAddress + f.plan9.HdrSize
+	if pclntab, err = loadPlan9Table(f.plan9, "runtime.pclntab", "runtime.epclntab"); err != nil {
+		// We didn't find the symbols, so look for the names used in 1.3 and earlier.
+		// TODO: Remove code looking for the old symbols when we no longer care about 1.3.
+		var err2 error
+		if pclntab, err2 = loadPlan9Table(f.plan9, "pclntab", "epclntab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	if symtab, err = loadPlan9Table(f.plan9, "runtime.symtab", "runtime.esymtab"); err != nil {
+		// Same as above.
+		var err2 error
+		if symtab, err2 = loadPlan9Table(f.plan9, "symtab", "esymtab"); err2 != nil {
+			return 0, nil, nil, err
+		}
+	}
+	return textStart, symtab, pclntab, nil
+}
+
+func (f *plan9File) text() (textStart uint64, text []byte, err error) {
+	sect := f.plan9.Section("text")
+	if sect == nil {
+		return 0, nil, fmt.Errorf("text section not found")
+	}
+	textStart = f.plan9.LoadAddress + f.plan9.HdrSize
+	text, err = sect.Data()
+	return
+}
+
+func findPlan9Symbol(f *plan9obj.File, name string) (*plan9obj.Sym, error) {
+	syms, err := f.Symbols()
+	if err != nil {
+		return nil, err
+	}
+	for _, s := range syms {
+		if s.Name != name {
+			continue
+		}
+		return &s, nil
+	}
+	return nil, fmt.Errorf("no %s symbol found", name)
+}
+
+func loadPlan9Table(f *plan9obj.File, sname, ename string) ([]byte, error) {
+	ssym, err := findPlan9Symbol(f, sname)
+	if err != nil {
+		return nil, err
+	}
+	esym, err := findPlan9Symbol(f, ename)
+	if err != nil {
+		return nil, err
+	}
+	sect := f.Section("text")
+	if sect == nil {
+		return nil, err
+	}
+	data, err := sect.Data()
+	if err != nil {
+		return nil, err
+	}
+	textStart := f.LoadAddress + f.HdrSize
+	return data[ssym.Value-textStart : esym.Value-textStart], nil
+}
+
+func (f *plan9File) goarch() string {
+	switch f.plan9.Magic {
+	case plan9obj.Magic386:
+		return "386"
+	case plan9obj.MagicAMD64:
+		return "amd64"
+	case plan9obj.MagicARM:
+		return "arm"
+	}
+	return ""
+}
+
+func (f *plan9File) loadAddress() (uint64, error) {
+	return 0, fmt.Errorf("unknown load address")
+}
+
+func (f *plan9File) dwarf() (*dwarf.Data, error) {
+	return nil, errors.New("no DWARF data in Plan 9 file")
+}