// 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() }