aboutsummaryrefslogtreecommitdiff
path: root/src/cmd/nm/nm.go
blob: 457239921bc34ff185f144467b7762bec1383f21 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
// 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"
	"flag"
	"fmt"
	"log"
	"os"
	"sort"

	"cmd/internal/objfile"
)

const helpText = `usage: go tool nm [options] file...
  -n
      an alias for -sort address (numeric),
      for compatibility with other nm commands
  -size
      print symbol size in decimal between address and type
  -sort {address,name,none,size}
      sort output in the given order (default name)
      size orders from largest to smallest
  -type
      print symbol type after name
`

func usage() {
	fmt.Fprintf(os.Stderr, helpText)
	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
}

func nm(file string) {
	f, err := objfile.Open(file)
	if err != nil {
		errorf("%v", err)
		return
	}
	defer f.Close()

	w := bufio.NewWriter(os.Stdout)

	entries := f.Entries()

	var found bool

	for _, e := range entries {
		syms, err := e.Symbols()
		if err != nil {
			errorf("reading %s: %v", file, err)
		}
		if len(syms) == 0 {
			continue
		}

		found = true

		switch *sortOrder {
		case "address":
			sort.Slice(syms, func(i, j int) bool { return syms[i].Addr < syms[j].Addr })
		case "name":
			sort.Slice(syms, func(i, j int) bool { return syms[i].Name < syms[j].Name })
		case "size":
			sort.Slice(syms, func(i, j int) bool { return syms[i].Size > syms[j].Size })
		}

		for _, sym := range syms {
			if len(entries) > 1 {
				name := e.Name()
				if name == "" {
					fmt.Fprintf(w, "%s(%s):\t", file, "_go_.o")
				} else {
					fmt.Fprintf(w, "%s(%s):\t", file, name)
				}
			} else 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")
		}
	}

	if !found {
		errorf("reading %s: no symbols", file)
	}

	w.Flush()
}