1 files changed, 184 insertions, 0 deletions
diff --git a/src/cmd/nm/nm.go b/src/cmd/nm/nm.go
new file mode 100644
index 000000000..a4036184e
--- /dev/null
+++ b/src/cmd/nm/nm.go
@@ -0,0 +1,184 @@
+// 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 main
+
+import (
+	"bufio"
+	"bytes"
+	"flag"
+	"fmt"
+	"io"
+	"log"
+	"os"
+	"sort"
+)
+
+func usage() {
+	fmt.Fprintf(os.Stderr, "usage: go tool nm [-n] [-size] [-sort order] [-type] file...\n")
+	os.Exit(2)
+}
+
+var (
+	sortOrder = flag.String("sort", "name", "")
+	printSize = flag.Bool("size", false, "")
+	printType = flag.Bool("type", false, "")
+
+	filePrefix = false
+)
+
+func init() {
+	flag.Var(nflag(0), "n", "") // alias for -sort address
+}
+
+type nflag int
+
+func (nflag) IsBoolFlag() bool {
+	return true
+}
+
+func (nflag) Set(value string) error {
+	if value == "true" {
+		*sortOrder = "address"
+	}
+	return nil
+}
+
+func (nflag) String() string {
+	if *sortOrder == "address" {
+		return "true"
+	}
+	return "false"
+}
+
+func main() {
+	log.SetFlags(0)
+	flag.Usage = usage
+	flag.Parse()
+
+	switch *sortOrder {
+	case "address", "name", "none", "size":
+		// ok
+	default:
+		fmt.Fprintf(os.Stderr, "nm: unknown sort order %q\n", *sortOrder)
+		os.Exit(2)
+	}
+
+	args := flag.Args()
+	filePrefix = len(args) > 1
+	if len(args) == 0 {
+		flag.Usage()
+	}
+
+	for _, file := range args {
+		nm(file)
+	}
+
+	os.Exit(exitCode)
+}
+
+var exitCode = 0
+
+func errorf(format string, args ...interface{}) {
+	log.Printf(format, args...)
+	exitCode = 1
+}
+
+type Sym struct {
+	Addr uint64
+	Size int64
+	Code rune
+	Name string
+	Type string
+}
+
+var parsers = []struct {
+	prefix []byte
+	parse  func(*os.File) []Sym
+}{
+	{[]byte("!<arch>\n"), goobjSymbols},
+	{[]byte("go object "), goobjSymbols},
+	{[]byte("\x7FELF"), elfSymbols},
+	{[]byte("\xFE\xED\xFA\xCE"), machoSymbols},
+	{[]byte("\xFE\xED\xFA\xCF"), machoSymbols},
+	{[]byte("\xCE\xFA\xED\xFE"), machoSymbols},
+	{[]byte("\xCF\xFA\xED\xFE"), machoSymbols},
+	{[]byte("MZ"), peSymbols},
+	{[]byte("\x00\x00\x01\xEB"), plan9Symbols}, // 386
+	{[]byte("\x00\x00\x04\x07"), plan9Symbols}, // mips
+	{[]byte("\x00\x00\x06\x47"), plan9Symbols}, // arm
+	{[]byte("\x00\x00\x8A\x97"), plan9Symbols}, // amd64
+}
+
+func nm(file string) {
+	f, err := os.Open(file)
+	if err != nil {
+		errorf("%v", err)
+		return
+	}
+	defer f.Close()
+
+	buf := make([]byte, 16)
+	io.ReadFull(f, buf)
+	f.Seek(0, 0)
+
+	var syms []Sym
+	for _, p := range parsers {
+		if bytes.HasPrefix(buf, p.prefix) {
+			syms = p.parse(f)
+			goto HaveSyms
+		}
+	}
+	errorf("%v: unknown file format", file)
+	return
+
+HaveSyms:
+	switch *sortOrder {
+	case "address":
+		sort.Sort(byAddr(syms))
+	case "name":
+		sort.Sort(byName(syms))
+	case "size":
+		sort.Sort(bySize(syms))
+	}
+
+	w := bufio.NewWriter(os.Stdout)
+	for _, sym := range syms {
+		if filePrefix {
+			fmt.Fprintf(w, "%s:\t", file)
+		}
+		if sym.Code == 'U' {
+			fmt.Fprintf(w, "%8s", "")
+		} else {
+			fmt.Fprintf(w, "%8x", sym.Addr)
+		}
+		if *printSize {
+			fmt.Fprintf(w, " %10d", sym.Size)
+		}
+		fmt.Fprintf(w, " %c %s", sym.Code, sym.Name)
+		if *printType && sym.Type != "" {
+			fmt.Fprintf(w, " %s", sym.Type)
+		}
+		fmt.Fprintf(w, "\n")
+	}
+	w.Flush()
+}
+
+type byAddr []Sym
+
+func (x byAddr) Len() int           { return len(x) }
+func (x byAddr) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+func (x byAddr) Less(i, j int) bool { return x[i].Addr < x[j].Addr }
+
+type byName []Sym
+
+func (x byName) Len() int           { return len(x) }
+func (x byName) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+func (x byName) Less(i, j int) bool { return x[i].Name < x[j].Name }
+
+type bySize []Sym
+
+func (x bySize) Len() int           { return len(x) }
+func (x bySize) Swap(i, j int)      { x[i], x[j] = x[j], x[i] }
+func (x bySize) Less(i, j int) bool { return x[i].Size > x[j].Size }