src/cmd/link/internal/ld/pobj.go

   1 // Inferno utils/6l/obj.c
   2 // http://code.google.com/p/inferno-os/source/browse/utils/6l/obj.c
   3 //
   4 //      Copyright © 1994-1999 Lucent Technologies Inc.  All rights reserved.
   5 //      Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net)
   6 //      Portions Copyright © 1997-1999 Vita Nuova Limited
   7 //      Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com)
   8 //      Portions Copyright © 2004,2006 Bruce Ellis
   9 //      Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net)
  10 //      Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others
  11 //      Portions Copyright © 2009 The Go Authors. All rights reserved.
  12 //
  13 // Permission is hereby granted, free of charge, to any person obtaining a copy
  14 // of this software and associated documentation files (the "Software"), to deal
  15 // in the Software without restriction, including without limitation the rights
  16 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  17 // copies of the Software, and to permit persons to whom the Software is
  18 // furnished to do so, subject to the following conditions:
  19 //
  20 // The above copyright notice and this permission notice shall be included in
  21 // all copies or substantial portions of the Software.
  22 //
  23 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  24 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  25 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL THE
  26 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  27 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  28 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  29 // THE SOFTWARE.
  30
  31 package ld
  32
  33 import (
  34         "bufio"
  35         "cmd/internal/obj"
  36         "cmd/internal/sys"
  37         "flag"
  38         "fmt"
  39         "os"
  40         "strings"
  41 )
  42
  43 var (
  44         pkglistfornote []byte
  45         buildid        string
  46 )
  47
  48 func Ldmain() {
  49         Bso = bufio.NewWriter(os.Stdout)
  50
  51         Ctxt = linknew(SysArch)
  52         Ctxt.Diag = Diag
  53         Ctxt.Bso = Bso
  54
  55         Debug = [128]int{}
  56         nerrors = 0
  57         outfile = ""
  58         HEADTYPE = -1
  59         INITTEXT = -1
  60         INITDAT = -1
  61         INITRND = -1
  62         INITENTRY = ""
  63         Linkmode = LinkAuto
  64
  65         // For testing behavior of go command when tools crash silently.
  66         // Undocumented, not in standard flag parser to avoid
  67         // exposing in usage message.
  68         for _, arg := range os.Args {
  69                 if arg == "-crash_for_testing" {
  70                         os.Exit(2)
  71                 }
  72         }
  73
  74         if SysArch.Family == sys.AMD64 && obj.Getgoos() == "plan9" {
  75                 obj.Flagcount("8", "use 64-bit addresses in symbol table", &Debug['8'])
  76         }
  77         obj.Flagfn1("B", "add an ELF NT_GNU_BUILD_ID `note` when using ELF", addbuildinfo)
  78         obj.Flagcount("C", "check Go calls to C code", &Debug['C'])
  79         obj.Flagint64("D", "set data segment `address`", &INITDAT)
  80         obj.Flagstr("E", "set `entry` symbol name", &INITENTRY)
  81         obj.Flagfn1("I", "use `linker` as ELF dynamic linker", setinterp)
  82         obj.Flagfn1("L", "add specified `directory` to library path", Lflag)
  83         obj.Flagfn1("H", "set header `type`", setheadtype)
  84         obj.Flagint32("R", "set address rounding `quantum`", &INITRND)
  85         obj.Flagint64("T", "set text segment `address`", &INITTEXT)
  86         obj.Flagfn0("V", "print version and exit", doversion)
  87         obj.Flagfn1("X", "add string value `definition` of the form importpath.name=value", addstrdata1)
  88         obj.Flagcount("a", "disassemble output", &Debug['a'])
  89         obj.Flagstr("buildid", "record `id` as Go toolchain build id", &buildid)
  90         flag.Var(&Buildmode, "buildmode", "set build `mode`")
  91         obj.Flagcount("c", "dump call graph", &Debug['c'])
  92         obj.Flagcount("d", "disable dynamic executable", &Debug['d'])
  93         flag.BoolVar(&flag_dumpdep, "dumpdep", false, "dump symbol dependency graph")
  94         obj.Flagstr("extar", "archive program for buildmode=c-archive", &extar)
  95         obj.Flagstr("extld", "use `linker` when linking in external mode", &extld)
  96         obj.Flagstr("extldflags", "pass `flags` to external linker", &extldflags)
  97         obj.Flagcount("f", "ignore version mismatch", &Debug['f'])
  98         obj.Flagcount("g", "disable go package data checks", &Debug['g'])
  99         obj.Flagcount("h", "halt on error", &Debug['h'])
 100         obj.Flagstr("installsuffix", "set package directory `suffix`", &flag_installsuffix)
 101         obj.Flagstr("k", "set field tracking `symbol`", &tracksym)
 102         obj.Flagstr("libgcc", "compiler support lib for internal linking; use \"none\" to disable", &libgccfile)
 103         obj.Flagfn1("linkmode", "set link `mode` (internal, external, auto)", setlinkmode)
 104         flag.BoolVar(&Linkshared, "linkshared", false, "link against installed Go shared libraries")
 105         obj.Flagcount("msan", "enable MSan interface", &flag_msan)
 106         obj.Flagcount("n", "dump symbol table", &Debug['n'])
 107         obj.Flagstr("o", "write output to `file`", &outfile)
 108         flag.Var(&rpath, "r", "set the ELF dynamic linker search `path` to dir1:dir2:...")
 109         obj.Flagcount("race", "enable race detector", &flag_race)
 110         obj.Flagcount("s", "disable symbol table", &Debug['s'])
 111         var flagShared int
 112         if SysArch.InFamily(sys.ARM, sys.AMD64) {
 113                 obj.Flagcount("shared", "generate shared object (implies -linkmode external)", &flagShared)
 114         }
 115         obj.Flagstr("tmpdir", "use `directory` for temporary files", &tmpdir)
 116         obj.Flagcount("u", "reject unsafe packages", &Debug['u'])
 117         obj.Flagcount("v", "print link trace", &Debug['v'])
 118         obj.Flagcount("w", "disable DWARF generation", &Debug['w'])
 119
 120         obj.Flagstr("cpuprofile", "write cpu profile to `file`", &cpuprofile)
 121         obj.Flagstr("memprofile", "write memory profile to `file`", &memprofile)
 122         obj.Flagint64("memprofilerate", "set runtime.MemProfileRate to `rate`", &memprofilerate)
 123
 124         obj.Flagparse(usage)
 125
 126         startProfile()
 127         Ctxt.Bso = Bso
 128         Ctxt.Debugvlog = int32(Debug['v'])
 129         if flagShared != 0 {
 130                 if Buildmode == BuildmodeUnset {
 131                         Buildmode = BuildmodeCShared
 132                 } else if Buildmode != BuildmodeCShared {
 133                         Exitf("-shared and -buildmode=%s are incompatible", Buildmode.String())
 134                 }
 135         }
 136         if Buildmode == BuildmodeUnset {
 137                 Buildmode = BuildmodeExe
 138         }
 139
 140         if Buildmode != BuildmodeShared && flag.NArg() != 1 {
 141                 usage()
 142         }
 143
 144         if outfile == "" {
 145                 outfile = "a.out"
 146                 if HEADTYPE == obj.Hwindows {
 147                         outfile += ".exe"
 148                 }
 149         }
 150
 151         libinit() // creates outfile
 152
 153         if HEADTYPE == -1 {
 154                 HEADTYPE = int32(headtype(goos))
 155         }
 156         Ctxt.Headtype = int(HEADTYPE)
 157         if headstring == "" {
 158                 headstring = Headstr(int(HEADTYPE))
 159         }
 160
 161         Thearch.Archinit()
 162
 163         if Linkshared && !Iself {
 164                 Exitf("-linkshared can only be used on elf systems")
 165         }
 166
 167         if Debug['v'] != 0 {
 168                 fmt.Fprintf(Bso, "HEADER = -H%d -T0x%x -D0x%x -R0x%x\n", HEADTYPE, uint64(INITTEXT), uint64(INITDAT), uint32(INITRND))
 169         }
 170         Bso.Flush()
 171
 172         if Buildmode == BuildmodeShared {
 173                 for i := 0; i < flag.NArg(); i++ {
 174                         arg := flag.Arg(i)
 175                         parts := strings.SplitN(arg, "=", 2)
 176                         var pkgpath, file string
 177                         if len(parts) == 1 {
 178                                 pkgpath, file = "main", arg
 179                         } else {
 180                                 pkgpath, file = parts[0], parts[1]
 181                         }
 182                         pkglistfornote = append(pkglistfornote, pkgpath...)
 183                         pkglistfornote = append(pkglistfornote, '\n')
 184                         addlibpath(Ctxt, "command line", "command line", file, pkgpath, "")
 185                 }
 186         } else {
 187                 addlibpath(Ctxt, "command line", "command line", flag.Arg(0), "main", "")
 188         }
 189         loadlib()
 190
 191         checkstrdata()
 192         deadcode(Ctxt)
 193         fieldtrack(Ctxt)
 194         callgraph()
 195
 196         doelf()
 197         if HEADTYPE == obj.Hdarwin {
 198                 domacho()
 199         }
 200         dostkcheck()
 201         if HEADTYPE == obj.Hwindows {
 202                 dope()
 203         }
 204         addexport()
 205         Thearch.Gentext() // trampolines, call stubs, etc.
 206         textbuildid()
 207         textaddress()
 208         pclntab()
 209         findfunctab()
 210         symtab()
 211         dodata()
 212         address()
 213         reloc()
 214         Thearch.Asmb()
 215         undef()
 216         hostlink()
 217         archive()
 218         if Debug['v'] != 0 {
 219                 fmt.Fprintf(Bso, "%5.2f cpu time\n", obj.Cputime())
 220                 fmt.Fprintf(Bso, "%d symbols\n", len(Ctxt.Allsym))
 221                 fmt.Fprintf(Bso, "%d liveness data\n", liveness)
 222         }
 223
 224         Bso.Flush()
 225
 226         errorexit()
 227 }