Golang obj.Flagparse函數代碼示例

//.........這裏部分代碼省略.........
	obj.Flagcount("j", "debug runtime-initialized variables", &Debug['j'])
	obj.Flagcount("l", "disable inlining", &Debug['l'])
	flag.StringVar(&linkobj, "linkobj", "", "write linker-specific object to `file`")
	obj.Flagcount("live", "debug liveness analysis", &debuglive)
	obj.Flagcount("m", "print optimization decisions", &Debug['m'])
	flag.BoolVar(&flag_msan, "msan", false, "build code compatible with C/C++ memory sanitizer")
	flag.BoolVar(&nolocalimports, "nolocalimports", false, "reject local (relative) imports")
	flag.StringVar(&outfile, "o", "", "write output to `file`")
	flag.StringVar(&myimportpath, "p", "", "set expected package import `path`")
	flag.BoolVar(&writearchive, "pack", false, "write package file instead of object file")
	obj.Flagcount("r", "debug generated wrappers", &Debug['r'])
	flag.BoolVar(&flag_race, "race", false, "enable race detector")
	obj.Flagcount("s", "warn about composite literals that can be simplified", &Debug['s'])
	flag.StringVar(&Ctxt.LineHist.TrimPathPrefix, "trimpath", "", "remove `prefix` from recorded source file paths")
	flag.BoolVar(&safemode, "u", false, "reject unsafe code")
	obj.Flagcount("v", "increase debug verbosity", &Debug['v'])
	obj.Flagcount("w", "debug type checking", &Debug['w'])
	flag.BoolVar(&use_writebarrier, "wb", true, "enable write barrier")
	obj.Flagcount("x", "debug lexer", &Debug['x'])
	var flag_shared bool
	var flag_dynlink bool
	if supportsDynlink(Thearch.LinkArch.Arch) {
		flag.BoolVar(&flag_shared, "shared", false, "generate code that can be linked into a shared library")
		flag.BoolVar(&flag_dynlink, "dynlink", false, "support references to Go symbols defined in other shared libraries")
	}
	if Thearch.LinkArch.Family == sys.AMD64 {
		flag.BoolVar(&flag_largemodel, "largemodel", false, "generate code that assumes a large memory model")
	}
	flag.StringVar(&cpuprofile, "cpuprofile", "", "write cpu profile to `file`")
	flag.StringVar(&memprofile, "memprofile", "", "write memory profile to `file`")
	flag.Int64Var(&memprofilerate, "memprofilerate", 0, "set runtime.MemProfileRate to `rate`")
	flag.StringVar(&traceprofile, "traceprofile", "", "write an execution trace to `file`")
	flag.StringVar(&benchfile, "bench", "", "append benchmark times to `file`")
	obj.Flagparse(usage)

	Ctxt.Flag_shared = flag_dynlink || flag_shared
	Ctxt.Flag_dynlink = flag_dynlink
	Ctxt.Flag_optimize = Debug['N'] == 0

	Ctxt.Debugasm = int32(Debug['S'])
	Ctxt.Debugvlog = int32(Debug['v'])

	if flag.NArg() < 1 {
		usage()
	}

	startProfile()

	if flag_race {
		racepkg = mkpkg("runtime/race")
		racepkg.Name = "race"
	}
	if flag_msan {
		msanpkg = mkpkg("runtime/msan")
		msanpkg.Name = "msan"
	}
	if flag_race && flag_msan {
		log.Fatal("cannot use both -race and -msan")
	} else if flag_race || flag_msan {
		instrumenting = true
	}

	// parse -d argument
	if debugstr != "" {
	Split:
		for _, name := range strings.Split(debugstr, ",") {

// Main is the main entry point for the linker code.
func Main() {
	ctxt := linknew(SysArch)
	ctxt.Bso = bufio.NewWriter(os.Stdout)

	// For testing behavior of go command when tools crash silently.
	// Undocumented, not in standard flag parser to avoid
	// exposing in usage message.
	for _, arg := range os.Args {
		if arg == "-crash_for_testing" {
			os.Exit(2)
		}
	}

	// TODO(matloob): define these above and then check flag values here
	if SysArch.Family == sys.AMD64 && obj.GOOS == "plan9" {
		flag.BoolVar(&Flag8, "8", false, "use 64-bit addresses in symbol table")
	}
	obj.Flagfn1("B", "add an ELF NT_GNU_BUILD_ID `note` when using ELF", addbuildinfo)
	obj.Flagfn1("L", "add specified `directory` to library path", func(a string) { Lflag(ctxt, a) })
	obj.Flagfn0("V", "print version and exit", doversion)
	obj.Flagfn1("X", "add string value `definition` of the form importpath.name=value", func(s string) { addstrdata1(ctxt, s) })
	obj.Flagcount("v", "print link trace", &ctxt.Debugvlog)

	obj.Flagparse(usage)

	startProfile()
	if Buildmode == BuildmodeUnset {
		Buildmode = BuildmodeExe
	}

	if Buildmode != BuildmodeShared && flag.NArg() != 1 {
		usage()
	}

	if *flagOutfile == "" {
		*flagOutfile = "a.out"
		if Headtype == obj.Hwindows || Headtype == obj.Hwindowsgui {
			*flagOutfile += ".exe"
		}
	}

	interpreter = *flagInterpreter

	libinit(ctxt) // creates outfile

	if Headtype == obj.Hunknown {
		Headtype.Set(obj.GOOS)
	}

	ctxt.computeTLSOffset()
	Thearch.Archinit(ctxt)

	if *FlagLinkshared && !Iself {
		Exitf("-linkshared can only be used on elf systems")
	}

	if ctxt.Debugvlog != 0 {
		ctxt.Logf("HEADER = -H%d -T0x%x -D0x%x -R0x%x\n", Headtype, uint64(*FlagTextAddr), uint64(*FlagDataAddr), uint32(*FlagRound))
	}

	switch Buildmode {
	case BuildmodeShared:
		for i := 0; i < flag.NArg(); i++ {
			arg := flag.Arg(i)
			parts := strings.SplitN(arg, "=", 2)
			var pkgpath, file string
			if len(parts) == 1 {
				pkgpath, file = "main", arg
			} else {
				pkgpath, file = parts[0], parts[1]
			}
			pkglistfornote = append(pkglistfornote, pkgpath...)
			pkglistfornote = append(pkglistfornote, '\n')
			addlibpath(ctxt, "command line", "command line", file, pkgpath, "")
		}
	case BuildmodePlugin:
		pluginName := strings.TrimSuffix(filepath.Base(flag.Arg(0)), ".a")
		addlibpath(ctxt, "command line", "command line", flag.Arg(0), pluginName, "")
	default:
		addlibpath(ctxt, "command line", "command line", flag.Arg(0), "main", "")
	}
	ctxt.loadlib()

	ctxt.checkstrdata()
	deadcode(ctxt)
	fieldtrack(ctxt)
	ctxt.callgraph()

	ctxt.doelf()
	if Headtype == obj.Hdarwin {
		ctxt.domacho()
	}
	ctxt.dostkcheck()
	if Headtype == obj.Hwindows || Headtype == obj.Hwindowsgui {
		ctxt.dope()
	}
	ctxt.addexport()
	Thearch.Gentext(ctxt) // trampolines, call stubs, etc.
	ctxt.textbuildid()
//.........這裏部分代碼省略.........

//.........這裏部分代碼省略.........
	obj.Flagcount("e", "no limit on number of errors reported", &Debug['e'])
	obj.Flagcount("f", "debug stack frames", &Debug['f'])
	obj.Flagcount("g", "debug code generation", &Debug['g'])
	obj.Flagcount("h", "halt on error", &Debug['h'])
	obj.Flagcount("i", "debug line number stack", &Debug['i'])
	obj.Flagstr("installsuffix", "pkg directory suffix", &flag_installsuffix)
	obj.Flagcount("j", "debug runtime-initialized variables", &Debug['j'])
	obj.Flagcount("l", "disable inlining", &Debug['l'])
	obj.Flagcount("live", "debug liveness analysis", &debuglive)
	obj.Flagcount("m", "print optimization decisions", &Debug['m'])
	obj.Flagcount("nolocalimports", "reject local (relative) imports", &nolocalimports)
	obj.Flagstr("o", "obj: set output file", &outfile)
	obj.Flagstr("p", "path: set expected package import path", &myimportpath)
	obj.Flagcount("pack", "write package file instead of object file", &writearchive)
	obj.Flagcount("r", "debug generated wrappers", &Debug['r'])
	obj.Flagcount("race", "enable race detector", &flag_race)
	obj.Flagcount("s", "warn about composite literals that can be simplified", &Debug['s'])
	obj.Flagstr("trimpath", "prefix: remove prefix from recorded source file paths", &Ctxt.Trimpath)
	obj.Flagcount("u", "reject unsafe code", &safemode)
	obj.Flagcount("v", "increase debug verbosity", &Debug['v'])
	obj.Flagcount("w", "debug type checking", &Debug['w'])
	use_writebarrier = 1
	obj.Flagcount("wb", "enable write barrier", &use_writebarrier)
	obj.Flagcount("x", "debug lexer", &Debug['x'])
	obj.Flagcount("y", "debug declarations in canned imports (with -d)", &Debug['y'])
	var flag_shared int
	if Thearch.Thechar == '6' {
		obj.Flagcount("largemodel", "generate code that assumes a large memory model", &flag_largemodel)
		obj.Flagcount("shared", "generate code that can be linked into a shared library", &flag_shared)
	}

	obj.Flagstr("cpuprofile", "file: write cpu profile to file", &cpuprofile)
	obj.Flagstr("memprofile", "file: write memory profile to file", &memprofile)
	obj.Flagparse(usage)
	Ctxt.Flag_shared = int32(flag_shared)
	Ctxt.Debugasm = int32(Debug['S'])
	Ctxt.Debugvlog = int32(Debug['v'])

	if flag.NArg() < 1 {
		usage()
	}

	startProfile()

	if flag_race != 0 {
		racepkg = mkpkg("runtime/race")
		racepkg.Name = "race"
	}

	// parse -d argument
	if debugstr != "" {
		var j int
		f := strings.Split(debugstr, ",")
		for i := range f {
			if f[i] == "" {
				continue
			}
			for j = 0; j < len(debugtab); j++ {
				if debugtab[j].name == f[i] {
					if debugtab[j].val != nil {
						*debugtab[j].val = 1
					}
					break
				}
			}

//.........這裏部分代碼省略.........
	obj.Flagcount("w", "disable DWARF generation", &Debug['w'])

	obj.Flagstr("cpuprofile", "write cpu profile to `file`", &cpuprofile)
	obj.Flagstr("memprofile", "write memory profile to `file`", &memprofile)
	obj.Flagint64("memprofilerate", "set runtime.MemProfileRate to `rate`", &memprofilerate)

	// Clumsy hack to preserve old two-argument -X name val syntax for old scripts.
	// Rewrite that syntax into new syntax -X name=val.
	// TODO(rsc): Delete this hack in Go 1.6 or later.
	var args []string
	for i := 0; i < len(os.Args); i++ {
		arg := os.Args[i]
		if (arg == "-X" || arg == "--X") && i+2 < len(os.Args) && !strings.Contains(os.Args[i+1], "=") {
			fmt.Fprintf(os.Stderr, "link: warning: option %s %s %s may not work in future releases; use %s %s=%s\n",
				arg, os.Args[i+1], os.Args[i+2],
				arg, os.Args[i+1], os.Args[i+2])
			args = append(args, arg)
			args = append(args, os.Args[i+1]+"="+os.Args[i+2])
			i += 2
			continue
		}
		if (strings.HasPrefix(arg, "-X=") || strings.HasPrefix(arg, "--X=")) && i+1 < len(os.Args) && strings.Count(arg, "=") == 1 {
			fmt.Fprintf(os.Stderr, "link: warning: option %s %s may not work in future releases; use %s=%s\n",
				arg, os.Args[i+1],
				arg, os.Args[i+1])
			args = append(args, arg+"="+os.Args[i+1])
			i++
			continue
		}
		args = append(args, arg)
	}
	os.Args = args

	obj.Flagparse(usage)

	startProfile()
	Ctxt.Bso = &Bso
	Ctxt.Debugvlog = int32(Debug['v'])
	if flagShared != 0 {
		if Buildmode == BuildmodeUnset {
			Buildmode = BuildmodeCShared
		} else if Buildmode != BuildmodeCShared {
			Exitf("-shared and -buildmode=%s are incompatible", Buildmode.String())
		}
	}
	if Buildmode == BuildmodeUnset {
		Buildmode = BuildmodeExe
	}

	if Buildmode != BuildmodeShared && flag.NArg() != 1 {
		usage()
	}

	if outfile == "" {
		outfile = "a.out"
		if HEADTYPE == obj.Hwindows {
			outfile += ".exe"
		}
	}

	libinit() // creates outfile

	if HEADTYPE == -1 {
		HEADTYPE = int32(headtype(goos))
	}
	Ctxt.Headtype = int(HEADTYPE)

// Main is the main entry point for the linker code.
func Main() {
	ctxt := linknew(SysArch)
	ctxt.Bso = bufio.NewWriter(os.Stdout)

	nerrors = 0
	HEADTYPE = -1
	Linkmode = LinkAuto

	// For testing behavior of go command when tools crash silently.
	// Undocumented, not in standard flag parser to avoid
	// exposing in usage message.
	for _, arg := range os.Args {
		if arg == "-crash_for_testing" {
			os.Exit(2)
		}
	}

	// TODO(matloob): define these above and then check flag values here
	if SysArch.Family == sys.AMD64 && obj.Getgoos() == "plan9" {
		flag.BoolVar(&Flag8, "8", false, "use 64-bit addresses in symbol table")
	}
	obj.Flagfn1("B", "add an ELF NT_GNU_BUILD_ID `note` when using ELF", addbuildinfo)
	obj.Flagfn1("L", "add specified `directory` to library path", func(a string) { Lflag(ctxt, a) })
	obj.Flagfn1("H", "set header `type`", setheadtype)
	obj.Flagfn0("V", "print version and exit", doversion)
	obj.Flagfn1("X", "add string value `definition` of the form importpath.name=value", func(s string) { addstrdata1(ctxt, s) })
	obj.Flagcount("v", "print link trace", &ctxt.Debugvlog)
	obj.Flagfn1("linkmode", "set link `mode` (internal, external, auto)", setlinkmode)
	var flagShared bool
	if SysArch.InFamily(sys.ARM, sys.AMD64) {
		flag.BoolVar(&flagShared, "shared", false, "generate shared object (implies -linkmode external)")
	}

	obj.Flagparse(usage)

	startProfile()
	if flagShared {
		if Buildmode == BuildmodeUnset {
			Buildmode = BuildmodeCShared
		} else if Buildmode != BuildmodeCShared {
			Exitf("-shared and -buildmode=%s are incompatible", Buildmode.String())
		}
	}
	if Buildmode == BuildmodeUnset {
		Buildmode = BuildmodeExe
	}

	if Buildmode != BuildmodeShared && flag.NArg() != 1 {
		usage()
	}

	if *flagOutfile == "" {
		*flagOutfile = "a.out"
		if HEADTYPE == obj.Hwindows {
			*flagOutfile += ".exe"
		}
	}

	interpreter = *flagInterpreter

	libinit(ctxt) // creates outfile

	if HEADTYPE == -1 {
		HEADTYPE = int32(headtype(goos))
	}
	ctxt.Headtype = int(HEADTYPE)
	if headstring == "" {
		headstring = Headstr(int(HEADTYPE))
	}

	Thearch.Archinit(ctxt)

	if *FlagLinkshared && !Iself {
		Exitf("-linkshared can only be used on elf systems")
	}

	if ctxt.Debugvlog != 0 {
		ctxt.Logf("HEADER = -H%d -T0x%x -D0x%x -R0x%x\n", HEADTYPE, uint64(*FlagTextAddr), uint64(*FlagDataAddr), uint32(*FlagRound))
	}

	if Buildmode == BuildmodeShared {
		for i := 0; i < flag.NArg(); i++ {
			arg := flag.Arg(i)
			parts := strings.SplitN(arg, "=", 2)
			var pkgpath, file string
			if len(parts) == 1 {
				pkgpath, file = "main", arg
			} else {
				pkgpath, file = parts[0], parts[1]
			}
			pkglistfornote = append(pkglistfornote, pkgpath...)
			pkglistfornote = append(pkglistfornote, '\n')
			addlibpath(ctxt, "command line", "command line", file, pkgpath, "")
		}
	} else {
		addlibpath(ctxt, "command line", "command line", flag.Arg(0), "main", "")
	}
	ctxt.loadlib()

//.........這裏部分代碼省略.........

//.........這裏部分代碼省略.........
	obj.Flagcount("msan", "build code compatible with C/C++ memory sanitizer", &flag_msan)
	obj.Flagcount("newexport", "use new export format", &newexport) // TODO(gri) remove eventually (issue 13241)
	obj.Flagcount("nolocalimports", "reject local (relative) imports", &nolocalimports)
	obj.Flagstr("o", "write output to `file`", &outfile)
	obj.Flagstr("p", "set expected package import `path`", &myimportpath)
	obj.Flagcount("pack", "write package file instead of object file", &writearchive)
	obj.Flagcount("r", "debug generated wrappers", &Debug['r'])
	obj.Flagcount("race", "enable race detector", &flag_race)
	obj.Flagcount("s", "warn about composite literals that can be simplified", &Debug['s'])
	obj.Flagstr("trimpath", "remove `prefix` from recorded source file paths", &Ctxt.LineHist.TrimPathPrefix)
	obj.Flagcount("u", "reject unsafe code", &safemode)
	obj.Flagcount("v", "increase debug verbosity", &Debug['v'])
	obj.Flagcount("w", "debug type checking", &Debug['w'])
	use_writebarrier = 1
	obj.Flagcount("wb", "enable write barrier", &use_writebarrier)
	obj.Flagcount("x", "debug lexer", &Debug['x'])
	obj.Flagcount("y", "debug declarations in canned imports (with -d)", &Debug['y'])
	var flag_shared int
	var flag_dynlink bool
	switch Thearch.Thechar {
	case '5', '6', '7', '8', '9':
		obj.Flagcount("shared", "generate code that can be linked into a shared library", &flag_shared)
	}
	if Thearch.Thechar == '6' {
		obj.Flagcount("largemodel", "generate code that assumes a large memory model", &flag_largemodel)
	}
	switch Thearch.Thechar {
	case '5', '6', '7', '8', '9':
		flag.BoolVar(&flag_dynlink, "dynlink", false, "support references to Go symbols defined in other shared libraries")
	}
	obj.Flagstr("cpuprofile", "write cpu profile to `file`", &cpuprofile)
	obj.Flagstr("memprofile", "write memory profile to `file`", &memprofile)
	obj.Flagint64("memprofilerate", "set runtime.MemProfileRate to `rate`", &memprofilerate)
	obj.Flagparse(usage)

	if flag_dynlink {
		flag_shared = 1
	}
	Ctxt.Flag_shared = int32(flag_shared)
	Ctxt.Flag_dynlink = flag_dynlink

	Ctxt.Debugasm = int32(Debug['S'])
	Ctxt.Debugvlog = int32(Debug['v'])

	if flag.NArg() < 1 {
		usage()
	}

	startProfile()

	if flag_race != 0 {
		racepkg = mkpkg("runtime/race")
		racepkg.Name = "race"
	}
	if flag_msan != 0 {
		msanpkg = mkpkg("runtime/msan")
		msanpkg.Name = "msan"
	}
	if flag_race != 0 && flag_msan != 0 {
		log.Fatal("can not use both -race and -msan")
	} else if flag_race != 0 || flag_msan != 0 {
		instrumenting = true
	}

	// parse -d argument
	if debugstr != "" {

func Ldmain() {
	Ctxt = linknew(Thelinkarch)
	Ctxt.Thechar = int32(Thearch.Thechar)
	Ctxt.Thestring = Thestring
	Ctxt.Diag = Diag
	Ctxt.Bso = &Bso

	Bso = *Binitw(os.Stdout)
	Debug = [128]int{}
	nerrors = 0
	outfile = ""
	HEADTYPE = -1
	INITTEXT = -1
	INITDAT = -1
	INITRND = -1
	INITENTRY = ""
	Linkmode = LinkAuto

	// For testing behavior of go command when tools crash.
	// Undocumented, not in standard flag parser to avoid
	// exposing in usage message.
	for _, arg := range os.Args {
		if arg == "-crash_for_testing" {
			*(*int)(nil) = 0
		}
	}

	if Thearch.Thechar == '5' && Ctxt.Goarm == 5 {
		Debug['F'] = 1
	}

	obj.Flagcount("1", "use alternate profiling code", &Debug['1'])
	if Thearch.Thechar == '6' {
		obj.Flagcount("8", "assume 64-bit addresses", &Debug['8'])
	}
	obj.Flagfn1("B", "info: define ELF NT_GNU_BUILD_ID note", addbuildinfo)
	obj.Flagcount("C", "check Go calls to C code", &Debug['C'])
	obj.Flagint64("D", "addr: data address", &INITDAT)
	obj.Flagstr("E", "sym: entry symbol", &INITENTRY)
	if Thearch.Thechar == '5' {
		obj.Flagcount("G", "debug pseudo-ops", &Debug['G'])
	}
	obj.Flagfn1("I", "interp: set ELF interp", setinterp)
	obj.Flagfn1("L", "dir: add dir to library path", Lflag)
	obj.Flagfn1("H", "head: header type", setheadtype)
	obj.Flagcount("K", "add stack underflow checks", &Debug['K'])
	if Thearch.Thechar == '5' {
		obj.Flagcount("M", "disable software div/mod", &Debug['M'])
	}
	obj.Flagcount("O", "print pc-line tables", &Debug['O'])
	obj.Flagcount("Q", "debug byte-register code gen", &Debug['Q'])
	if Thearch.Thechar == '5' {
		obj.Flagcount("P", "debug code generation", &Debug['P'])
	}
	obj.Flagint32("R", "rnd: address rounding", &INITRND)
	obj.Flagcount("nil", "check type signatures", &Debug['S'])
	obj.Flagint64("T", "addr: text address", &INITTEXT)
	obj.Flagfn0("V", "print version and exit", doversion)
	obj.Flagcount("W", "disassemble input", &Debug['W'])
	obj.Flagfn1("X", "name value: define string data", addstrdata1)
	obj.Flagcount("Z", "clear stack frame on entry", &Debug['Z'])
	obj.Flagcount("a", "disassemble output", &Debug['a'])
	obj.Flagcount("c", "dump call graph", &Debug['c'])
	obj.Flagcount("d", "disable dynamic executable", &Debug['d'])
	obj.Flagstr("extld", "ld: linker to run in external mode", &extld)
	obj.Flagstr("extldflags", "ldflags: flags for external linker", &extldflags)
	obj.Flagcount("f", "ignore version mismatch", &Debug['f'])
	obj.Flagcount("g", "disable go package data checks", &Debug['g'])
	obj.Flagstr("installsuffix", "suffix: pkg directory suffix", &flag_installsuffix)
	obj.Flagstr("k", "sym: set field tracking symbol", &tracksym)
	obj.Flagfn1("linkmode", "mode: set link mode (internal, external, auto)", setlinkmode)
	obj.Flagcount("n", "dump symbol table", &Debug['n'])
	obj.Flagstr("o", "outfile: set output file", &outfile)
	obj.Flagstr("r", "dir1:dir2:...: set ELF dynamic linker search path", &rpath)
	obj.Flagcount("race", "enable race detector", &flag_race)
	obj.Flagcount("s", "disable symbol table", &Debug['s'])
	if Thearch.Thechar == '5' || Thearch.Thechar == '6' {
		obj.Flagcount("shared", "generate shared object (implies -linkmode external)", &Flag_shared)
	}
	obj.Flagstr("tmpdir", "dir: leave temporary files in this directory", &tmpdir)
	obj.Flagcount("u", "reject unsafe packages", &Debug['u'])
	obj.Flagcount("v", "print link trace", &Debug['v'])
	obj.Flagcount("w", "disable DWARF generation", &Debug['w'])

	// Clumsy hack to preserve old behavior of -X taking two arguments.
	for i := 0; i < len(os.Args); i++ {
		arg := os.Args[i]
		if (arg == "--X" || arg == "-X") && i+2 < len(os.Args) {
			os.Args[i+2] = "-X=VALUE:" + os.Args[i+2]
			i += 2
		} else if (strings.HasPrefix(arg, "--X=") || strings.HasPrefix(arg, "-X=")) && i+1 < len(os.Args) {
			os.Args[i+1] = "-X=VALUE:" + os.Args[i+1]
			i++
		}
	}
	obj.Flagstr("cpuprofile", "file: write cpu profile to file", &cpuprofile)
	obj.Flagstr("memprofile", "file: write memory profile to file", &memprofile)
	obj.Flagparse(usage)
	startProfile()
	Ctxt.Bso = &Bso
//.........這裏部分代碼省略.........

//.........這裏部分代碼省略.........
	obj.Flagcount("g", "disable go package data checks", &Debug['g'])
	obj.Flagstr("installsuffix", "set package directory `suffix`", &flag_installsuffix)
	obj.Flagstr("k", "set field tracking `symbol`", &tracksym)
	obj.Flagfn1("linkmode", "set link `mode` (internal, external, auto)", setlinkmode)
	flag.BoolVar(&Linkshared, "linkshared", false, "link against installed Go shared libraries")
	obj.Flagcount("n", "dump symbol table", &Debug['n'])
	obj.Flagstr("o", "write output to `file`", &outfile)
	flag.Var(&rpath, "r", "set the ELF dynamic linker search `path` to dir1:dir2:...")
	obj.Flagcount("race", "enable race detector", &flag_race)
	obj.Flagcount("s", "disable symbol table", &Debug['s'])
	var flagShared int
	if Thearch.Thechar == '5' || Thearch.Thechar == '6' {
		obj.Flagcount("shared", "generate shared object (implies -linkmode external)", &flagShared)
	}
	obj.Flagstr("tmpdir", "use `directory` for temporary files", &tmpdir)
	obj.Flagcount("u", "reject unsafe packages", &Debug['u'])
	obj.Flagcount("v", "print link trace", &Debug['v'])
	obj.Flagcount("w", "disable DWARF generation", &Debug['w'])

	// Clumsy hack to preserve old behavior of -X taking two arguments.
	for i := 0; i < len(os.Args); i++ {
		arg := os.Args[i]
		if (arg == "--X" || arg == "-X") && i+2 < len(os.Args) {
			os.Args[i+2] = "-X=VALUE:" + os.Args[i+2]
			i += 2
		} else if (strings.HasPrefix(arg, "--X=") || strings.HasPrefix(arg, "-X=")) && i+1 < len(os.Args) {
			os.Args[i+1] = "-X=VALUE:" + os.Args[i+1]
			i++
		}
	}
	obj.Flagstr("cpuprofile", "write cpu profile to `file`", &cpuprofile)
	obj.Flagstr("memprofile", "write memory profile to `file`", &memprofile)
	obj.Flagint64("memprofilerate", "set runtime.MemProfileRate to `rate`", &memprofilerate)
	obj.Flagparse(usage)
	startProfile()
	Ctxt.Bso = &Bso
	Ctxt.Debugvlog = int32(Debug['v'])
	if flagShared != 0 {
		if Buildmode == BuildmodeExe {
			Buildmode = BuildmodeCShared
		} else if Buildmode != BuildmodeCShared {
			Exitf("-shared and -buildmode=%s are incompatible", Buildmode.String())
		}
	}

	if Buildmode != BuildmodeShared && flag.NArg() != 1 {
		usage()
	}

	if outfile == "" {
		if HEADTYPE == obj.Hwindows {
			outfile = fmt.Sprintf("%c.out.exe", Thearch.Thechar)
		} else {
			outfile = fmt.Sprintf("%c.out", Thearch.Thechar)
		}
	}

	libinit() // creates outfile

	if HEADTYPE == -1 {
		HEADTYPE = int32(headtype(goos))
	}
	Ctxt.Headtype = int(HEADTYPE)
	if headstring == "" {
		headstring = Headstr(int(HEADTYPE))
	}

func Ldmain() {
	Bso = bufio.NewWriter(os.Stdout)

	Ctxt = linknew(SysArch)
	Ctxt.Diag = Diag
	Ctxt.Bso = Bso

	Debug = [128]int{}
	nerrors = 0
	outfile = ""
	HEADTYPE = -1
	INITTEXT = -1
	INITDAT = -1
	INITRND = -1
	INITENTRY = ""
	Linkmode = LinkAuto

	// For testing behavior of go command when tools crash silently.
	// Undocumented, not in standard flag parser to avoid
	// exposing in usage message.
	for _, arg := range os.Args {
		if arg == "-crash_for_testing" {
			os.Exit(2)
		}
	}

	if SysArch.Family == sys.AMD64 && obj.Getgoos() == "plan9" {
		obj.Flagcount("8", "use 64-bit addresses in symbol table", &Debug['8'])
	}
	obj.Flagfn1("B", "add an ELF NT_GNU_BUILD_ID `note` when using ELF", addbuildinfo)
	obj.Flagcount("C", "check Go calls to C code", &Debug['C'])
	obj.Flagint64("D", "set data segment `address`", &INITDAT)
	obj.Flagstr("E", "set `entry` symbol name", &INITENTRY)
	obj.Flagfn1("I", "use `linker` as ELF dynamic linker", setinterp)
	obj.Flagfn1("L", "add specified `directory` to library path", Lflag)
	obj.Flagfn1("H", "set header `type`", setheadtype)
	obj.Flagint32("R", "set address rounding `quantum`", &INITRND)
	obj.Flagint64("T", "set text segment `address`", &INITTEXT)
	obj.Flagfn0("V", "print version and exit", doversion)
	obj.Flagfn1("X", "add string value `definition` of the form importpath.name=value", addstrdata1)
	obj.Flagcount("a", "disassemble output", &Debug['a'])
	obj.Flagstr("buildid", "record `id` as Go toolchain build id", &buildid)
	flag.Var(&Buildmode, "buildmode", "set build `mode`")
	obj.Flagcount("c", "dump call graph", &Debug['c'])
	obj.Flagcount("d", "disable dynamic executable", &Debug['d'])
	flag.BoolVar(&flag_dumpdep, "dumpdep", false, "dump symbol dependency graph")
	obj.Flagstr("extar", "archive program for buildmode=c-archive", &extar)
	obj.Flagstr("extld", "use `linker` when linking in external mode", &extld)
	obj.Flagstr("extldflags", "pass `flags` to external linker", &extldflags)
	obj.Flagcount("f", "ignore version mismatch", &Debug['f'])
	obj.Flagcount("g", "disable go package data checks", &Debug['g'])
	obj.Flagcount("h", "halt on error", &Debug['h'])
	obj.Flagstr("installsuffix", "set package directory `suffix`", &flag_installsuffix)
	obj.Flagstr("k", "set field tracking `symbol`", &tracksym)
	obj.Flagstr("libgcc", "compiler support lib for internal linking; use \"none\" to disable", &libgccfile)
	obj.Flagfn1("linkmode", "set link `mode` (internal, external, auto)", setlinkmode)
	flag.BoolVar(&Linkshared, "linkshared", false, "link against installed Go shared libraries")
	obj.Flagcount("msan", "enable MSan interface", &flag_msan)
	obj.Flagcount("n", "dump symbol table", &Debug['n'])
	obj.Flagstr("o", "write output to `file`", &outfile)
	flag.Var(&rpath, "r", "set the ELF dynamic linker search `path` to dir1:dir2:...")
	obj.Flagcount("race", "enable race detector", &flag_race)
	obj.Flagcount("s", "disable symbol table", &Debug['s'])
	var flagShared int
	if SysArch.InFamily(sys.ARM, sys.AMD64) {
		obj.Flagcount("shared", "generate shared object (implies -linkmode external)", &flagShared)
	}
	obj.Flagstr("tmpdir", "use `directory` for temporary files", &tmpdir)
	obj.Flagcount("u", "reject unsafe packages", &Debug['u'])
	obj.Flagcount("v", "print link trace", &Debug['v'])
	obj.Flagcount("w", "disable DWARF generation", &Debug['w'])

	obj.Flagstr("cpuprofile", "write cpu profile to `file`", &cpuprofile)
	obj.Flagstr("memprofile", "write memory profile to `file`", &memprofile)
	obj.Flagint64("memprofilerate", "set runtime.MemProfileRate to `rate`", &memprofilerate)

	obj.Flagparse(usage)

	startProfile()
	Ctxt.Bso = Bso
	Ctxt.Debugvlog = int32(Debug['v'])
	if flagShared != 0 {
		if Buildmode == BuildmodeUnset {
			Buildmode = BuildmodeCShared
		} else if Buildmode != BuildmodeCShared {
			Exitf("-shared and -buildmode=%s are incompatible", Buildmode.String())
		}
	}
	if Buildmode == BuildmodeUnset {
		Buildmode = BuildmodeExe
	}

	if Buildmode != BuildmodeShared && flag.NArg() != 1 {
		usage()
	}

	if outfile == "" {
		outfile = "a.out"
		if HEADTYPE == obj.Hwindows {
			outfile += ".exe"
//.........這裏部分代碼省略.........