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" } } libinit() // creates outfile if HEADTYPE == -1 { HEADTYPE = int32(headtype(goos)) } Ctxt.Headtype = int(HEADTYPE) if headstring == "" { headstring = Headstr(int(HEADTYPE)) } Thearch.Archinit() if Linkshared && !Iself { Exitf("-linkshared can only be used on elf systems") } if Debug['v'] != 0 { fmt.Fprintf(Bso, "HEADER = -H%d -T0x%x -D0x%x -R0x%x\n", HEADTYPE, uint64(INITTEXT), uint64(INITDAT), uint32(INITRND)) } Bso.Flush() 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", "") } loadlib() checkstrdata() deadcode(Ctxt) fieldtrack(Ctxt) callgraph() doelf() if HEADTYPE == obj.Hdarwin { domacho() } dostkcheck() if HEADTYPE == obj.Hwindows { dope() } addexport() Thearch.Gentext() // trampolines, call stubs, etc. textbuildid() textaddress() pclntab() findfunctab() symtab() dodata() address() reloc() Thearch.Asmb() undef() hostlink() archive() if Debug['v'] != 0 { fmt.Fprintf(Bso, "%5.2f cpu time\n", obj.Cputime()) fmt.Fprintf(Bso, "%d symbols\n", len(Ctxt.Allsym)) fmt.Fprintf(Bso, "%d liveness data\n", liveness) } Bso.Flush() errorexit() }
func asmb() { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f asmb\n", obj.Cputime()) } ld.Bso.Flush() if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f codeblk\n", obj.Cputime()) } ld.Bso.Flush() if ld.Iself { ld.Asmbelfsetup() } sect := ld.Segtext.Sect ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) // 0xCC is INT $3 - breakpoint instruction ld.CodeblkPad(int64(sect.Vaddr), int64(sect.Length), []byte{0xCC}) for sect = sect.Next; sect != nil; sect = sect.Next { ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) ld.Datblk(int64(sect.Vaddr), int64(sect.Length)) } if ld.Segrodata.Filelen > 0 { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f rodatblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segrodata.Fileoff)) ld.Datblk(int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen)) } if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f datblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segdata.Fileoff)) ld.Datblk(int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen)) ld.Cseek(int64(ld.Segdwarf.Fileoff)) ld.Dwarfblk(int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen)) machlink := int64(0) if ld.HEADTYPE == obj.Hdarwin { machlink = ld.Domacholink() } switch ld.HEADTYPE { default: ld.Diag("unknown header type %d", ld.HEADTYPE) fallthrough case obj.Hplan9: break case obj.Hdarwin: ld.Debug['8'] = 1 /* 64-bit addresses */ case obj.Hlinux, obj.Hfreebsd, obj.Hnetbsd, obj.Hopenbsd, obj.Hdragonfly, obj.Hsolaris: ld.Debug['8'] = 1 /* 64-bit addresses */ case obj.Hnacl, obj.Hwindows: break } ld.Symsize = 0 ld.Spsize = 0 ld.Lcsize = 0 symo := int64(0) if ld.Debug['s'] == 0 { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f sym\n", obj.Cputime()) } ld.Bso.Flush() switch ld.HEADTYPE { default: case obj.Hplan9: ld.Debug['s'] = 1 symo = int64(ld.Segdata.Fileoff + ld.Segdata.Filelen) case obj.Hdarwin: symo = int64(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(ld.INITRND))) + uint64(machlink)) case obj.Hlinux, obj.Hfreebsd, obj.Hnetbsd, obj.Hopenbsd, obj.Hdragonfly, obj.Hsolaris, obj.Hnacl: symo = int64(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) symo = ld.Rnd(symo, int64(ld.INITRND)) case obj.Hwindows: symo = int64(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) symo = ld.Rnd(symo, ld.PEFILEALIGN) } ld.Cseek(symo) switch ld.HEADTYPE { default: if ld.Iself { ld.Cseek(symo) ld.Asmelfsym() ld.Cflush() ld.Cwrite(ld.Elfstrdat) if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f dwarf\n", obj.Cputime()) } if ld.Linkmode == ld.LinkExternal { ld.Elfemitreloc() } } case obj.Hplan9: ld.Asmplan9sym() ld.Cflush() sym := ld.Linklookup(ld.Ctxt, "pclntab", 0) if sym != nil { ld.Lcsize = int32(len(sym.P)) for i := 0; int32(i) < ld.Lcsize; i++ { ld.Cput(sym.P[i]) } ld.Cflush() } case obj.Hwindows: if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f dwarf\n", obj.Cputime()) } case obj.Hdarwin: if ld.Linkmode == ld.LinkExternal { ld.Machoemitreloc() } } } if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f headr\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(0) switch ld.HEADTYPE { default: case obj.Hplan9: /* plan9 */ magic := int32(4*26*26 + 7) magic |= 0x00008000 /* fat header */ ld.Lputb(uint32(magic)) /* magic */ ld.Lputb(uint32(ld.Segtext.Filelen)) /* sizes */ ld.Lputb(uint32(ld.Segdata.Filelen)) ld.Lputb(uint32(ld.Segdata.Length - ld.Segdata.Filelen)) ld.Lputb(uint32(ld.Symsize)) /* nsyms */ vl := ld.Entryvalue() ld.Lputb(PADDR(uint32(vl))) /* va of entry */ ld.Lputb(uint32(ld.Spsize)) /* sp offsets */ ld.Lputb(uint32(ld.Lcsize)) /* line offsets */ ld.Vputb(uint64(vl)) /* va of entry */ case obj.Hdarwin: ld.Asmbmacho() case obj.Hlinux, obj.Hfreebsd, obj.Hnetbsd, obj.Hopenbsd, obj.Hdragonfly, obj.Hsolaris, obj.Hnacl: ld.Asmbelf(symo) case obj.Hwindows: ld.Asmbpe() } ld.Cflush() }
func pclntab() { funcdata_bytes := int64(0) ftab := Linklookup(Ctxt, "runtime.pclntab", 0) ftab.Type = obj.SPCLNTAB ftab.Attr |= AttrReachable // See golang.org/s/go12symtab for the format. Briefly: // 8-byte header // nfunc [thearch.ptrsize bytes] // function table, alternating PC and offset to func struct [each entry thearch.ptrsize bytes] // end PC [thearch.ptrsize bytes] // offset to file table [4 bytes] nfunc := int32(0) // Find container symbols, mark them with SCONTAINER for _, s := range Ctxt.Textp { if s.Outer != nil { s.Outer.Type |= obj.SCONTAINER } } for _, s := range Ctxt.Textp { if container(s) == 0 { nfunc++ } } pclntabNfunc = nfunc Symgrow(Ctxt, ftab, 8+int64(SysArch.PtrSize)+int64(nfunc)*2*int64(SysArch.PtrSize)+int64(SysArch.PtrSize)+4) setuint32(Ctxt, ftab, 0, 0xfffffffb) setuint8(Ctxt, ftab, 6, uint8(SysArch.MinLC)) setuint8(Ctxt, ftab, 7, uint8(SysArch.PtrSize)) setuintxx(Ctxt, ftab, 8, uint64(nfunc), int64(SysArch.PtrSize)) pclntabPclntabOffset = int32(8 + SysArch.PtrSize) nfunc = 0 var last *LSym for _, Ctxt.Cursym = range Ctxt.Textp { last = Ctxt.Cursym if container(Ctxt.Cursym) != 0 { continue } pcln := Ctxt.Cursym.FuncInfo if pcln == nil { pcln = &pclntab_zpcln } if pclntabFirstFunc == nil { pclntabFirstFunc = Ctxt.Cursym } funcstart := int32(len(ftab.P)) funcstart += int32(-len(ftab.P)) & (int32(SysArch.PtrSize) - 1) setaddr(Ctxt, ftab, 8+int64(SysArch.PtrSize)+int64(nfunc)*2*int64(SysArch.PtrSize), Ctxt.Cursym) setuintxx(Ctxt, ftab, 8+int64(SysArch.PtrSize)+int64(nfunc)*2*int64(SysArch.PtrSize)+int64(SysArch.PtrSize), uint64(funcstart), int64(SysArch.PtrSize)) // fixed size of struct, checked below off := funcstart end := funcstart + int32(SysArch.PtrSize) + 3*4 + 5*4 + int32(len(pcln.Pcdata))*4 + int32(len(pcln.Funcdata))*int32(SysArch.PtrSize) if len(pcln.Funcdata) > 0 && (end&int32(SysArch.PtrSize-1) != 0) { end += 4 } Symgrow(Ctxt, ftab, int64(end)) // entry uintptr off = int32(setaddr(Ctxt, ftab, int64(off), Ctxt.Cursym)) // name int32 off = int32(setuint32(Ctxt, ftab, int64(off), uint32(ftabaddstring(ftab, Ctxt.Cursym.Name)))) // args int32 // TODO: Move into funcinfo. args := uint32(0) if Ctxt.Cursym.FuncInfo != nil { args = uint32(Ctxt.Cursym.FuncInfo.Args) } off = int32(setuint32(Ctxt, ftab, int64(off), args)) // frame int32 // This has been removed (it was never set quite correctly anyway). // Nothing should use it. // Leave an obviously incorrect value. // TODO: Remove entirely. off = int32(setuint32(Ctxt, ftab, int64(off), 0x1234567)) if pcln != &pclntab_zpcln { renumberfiles(Ctxt, pcln.File, &pcln.Pcfile) if false { // Sanity check the new numbering var it Pciter for pciterinit(Ctxt, &it, &pcln.Pcfile); it.done == 0; pciternext(&it) { if it.value < 1 || it.value > int32(len(Ctxt.Filesyms)) { Diag("bad file number in pcfile: %d not in range [1, %d]\n", it.value, len(Ctxt.Filesyms)) errorexit() } } } } // pcdata off = addpctab(ftab, off, &pcln.Pcsp) off = addpctab(ftab, off, &pcln.Pcfile) off = addpctab(ftab, off, &pcln.Pcline) off = int32(setuint32(Ctxt, ftab, int64(off), uint32(len(pcln.Pcdata)))) off = int32(setuint32(Ctxt, ftab, int64(off), uint32(len(pcln.Funcdata)))) for i := 0; i < len(pcln.Pcdata); i++ { off = addpctab(ftab, off, &pcln.Pcdata[i]) } // funcdata, must be pointer-aligned and we're only int32-aligned. // Missing funcdata will be 0 (nil pointer). if len(pcln.Funcdata) > 0 { if off&int32(SysArch.PtrSize-1) != 0 { off += 4 } for i := 0; i < len(pcln.Funcdata); i++ { if pcln.Funcdata[i] == nil { setuintxx(Ctxt, ftab, int64(off)+int64(SysArch.PtrSize)*int64(i), uint64(pcln.Funcdataoff[i]), int64(SysArch.PtrSize)) } else { // TODO: Dedup. funcdata_bytes += pcln.Funcdata[i].Size setaddrplus(Ctxt, ftab, int64(off)+int64(SysArch.PtrSize)*int64(i), pcln.Funcdata[i], pcln.Funcdataoff[i]) } } off += int32(len(pcln.Funcdata)) * int32(SysArch.PtrSize) } if off != end { Diag("bad math in functab: funcstart=%d off=%d but end=%d (npcdata=%d nfuncdata=%d ptrsize=%d)", funcstart, off, end, len(pcln.Pcdata), len(pcln.Funcdata), SysArch.PtrSize) errorexit() } nfunc++ } pclntabLastFunc = last // Final entry of table is just end pc. setaddrplus(Ctxt, ftab, 8+int64(SysArch.PtrSize)+int64(nfunc)*2*int64(SysArch.PtrSize), last, last.Size) // Start file table. start := int32(len(ftab.P)) start += int32(-len(ftab.P)) & (int32(SysArch.PtrSize) - 1) pclntabFiletabOffset = start setuint32(Ctxt, ftab, 8+int64(SysArch.PtrSize)+int64(nfunc)*2*int64(SysArch.PtrSize)+int64(SysArch.PtrSize), uint32(start)) Symgrow(Ctxt, ftab, int64(start)+(int64(len(Ctxt.Filesyms))+1)*4) setuint32(Ctxt, ftab, int64(start), uint32(len(Ctxt.Filesyms))) for i := len(Ctxt.Filesyms) - 1; i >= 0; i-- { s := Ctxt.Filesyms[i] setuint32(Ctxt, ftab, int64(start)+s.Value*4, uint32(ftabaddstring(ftab, s.Name))) } ftab.Size = int64(len(ftab.P)) if Debug['v'] != 0 { fmt.Fprintf(Bso, "%5.2f pclntab=%d bytes, funcdata total %d bytes\n", obj.Cputime(), ftab.Size, funcdata_bytes) } }
func asmb() { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f asmb\n", obj.Cputime()) } ld.Bso.Flush() if ld.Iself { ld.Asmbelfsetup() } sect := ld.Segtext.Sect ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) ld.Codeblk(int64(sect.Vaddr), int64(sect.Length)) for sect = sect.Next; sect != nil; sect = sect.Next { ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) ld.Datblk(int64(sect.Vaddr), int64(sect.Length)) } if ld.Segrodata.Filelen > 0 { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f rodatblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segrodata.Fileoff)) ld.Datblk(int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen)) } if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f datblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segdata.Fileoff)) ld.Datblk(int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen)) ld.Cseek(int64(ld.Segdwarf.Fileoff)) ld.Dwarfblk(int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen)) /* output symbol table */ ld.Symsize = 0 ld.Lcsize = 0 symo := uint32(0) if ld.Debug['s'] == 0 { // TODO: rationalize if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f sym\n", obj.Cputime()) } ld.Bso.Flush() switch ld.HEADTYPE { default: if ld.Iself { symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) symo = uint32(ld.Rnd(int64(symo), int64(ld.INITRND))) } case obj.Hplan9: symo = uint32(ld.Segdata.Fileoff + ld.Segdata.Filelen) } ld.Cseek(int64(symo)) switch ld.HEADTYPE { default: if ld.Iself { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f elfsym\n", obj.Cputime()) } ld.Asmelfsym() ld.Cflush() ld.Cwrite(ld.Elfstrdat) if ld.Linkmode == ld.LinkExternal { ld.Elfemitreloc() } } case obj.Hplan9: ld.Asmplan9sym() ld.Cflush() sym := ld.Linklookup(ld.Ctxt, "pclntab", 0) if sym != nil { ld.Lcsize = int32(len(sym.P)) for i := 0; int32(i) < ld.Lcsize; i++ { ld.Cput(sym.P[i]) } ld.Cflush() } } } ld.Ctxt.Cursym = nil if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f header\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(0) switch ld.HEADTYPE { default: case obj.Hplan9: /* plan 9 */ ld.Thearch.Lput(0x647) /* magic */ ld.Thearch.Lput(uint32(ld.Segtext.Filelen)) /* sizes */ ld.Thearch.Lput(uint32(ld.Segdata.Filelen)) ld.Thearch.Lput(uint32(ld.Segdata.Length - ld.Segdata.Filelen)) ld.Thearch.Lput(uint32(ld.Symsize)) /* nsyms */ ld.Thearch.Lput(uint32(ld.Entryvalue())) /* va of entry */ ld.Thearch.Lput(0) ld.Thearch.Lput(uint32(ld.Lcsize)) case obj.Hlinux, obj.Hfreebsd, obj.Hnetbsd, obj.Hopenbsd, obj.Hnacl: ld.Asmbelf(int64(symo)) } ld.Cflush() if ld.Debug['c'] != 0 { fmt.Printf("textsize=%d\n", ld.Segtext.Filelen) fmt.Printf("datsize=%d\n", ld.Segdata.Filelen) fmt.Printf("bsssize=%d\n", ld.Segdata.Length-ld.Segdata.Filelen) fmt.Printf("symsize=%d\n", ld.Symsize) fmt.Printf("lcsize=%d\n", ld.Lcsize) fmt.Printf("total=%d\n", ld.Segtext.Filelen+ld.Segdata.Length+uint64(ld.Symsize)+uint64(ld.Lcsize)) } }
func asmb() { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f asmb\n", obj.Cputime()) } ld.Bso.Flush() if ld.Iself { ld.Asmbelfsetup() } sect := ld.Segtext.Sect ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) // 0xCC is INT $3 - breakpoint instruction ld.CodeblkPad(int64(sect.Vaddr), int64(sect.Length), []byte{0xCC}) for sect = sect.Next; sect != nil; sect = sect.Next { ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) ld.Datblk(int64(sect.Vaddr), int64(sect.Length)) } if ld.Segrodata.Filelen > 0 { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f rodatblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segrodata.Fileoff)) ld.Datblk(int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen)) } if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f datblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segdata.Fileoff)) ld.Datblk(int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen)) ld.Cseek(int64(ld.Segdwarf.Fileoff)) ld.Dwarfblk(int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen)) machlink := uint32(0) if ld.HEADTYPE == obj.Hdarwin { machlink = uint32(ld.Domacholink()) } ld.Symsize = 0 ld.Spsize = 0 ld.Lcsize = 0 symo := uint32(0) if ld.Debug['s'] == 0 { // TODO: rationalize if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f sym\n", obj.Cputime()) } ld.Bso.Flush() switch ld.HEADTYPE { default: if ld.Iself { symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) symo = uint32(ld.Rnd(int64(symo), int64(ld.INITRND))) } case obj.Hplan9: symo = uint32(ld.Segdata.Fileoff + ld.Segdata.Filelen) case obj.Hdarwin: symo = uint32(ld.Segdwarf.Fileoff + uint64(ld.Rnd(int64(ld.Segdwarf.Filelen), int64(ld.INITRND))) + uint64(machlink)) case obj.Hwindows: symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) symo = uint32(ld.Rnd(int64(symo), ld.PEFILEALIGN)) } ld.Cseek(int64(symo)) switch ld.HEADTYPE { default: if ld.Iself { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f elfsym\n", obj.Cputime()) } ld.Asmelfsym() ld.Cflush() ld.Cwrite(ld.Elfstrdat) if ld.Linkmode == ld.LinkExternal { ld.Elfemitreloc() } } case obj.Hplan9: ld.Asmplan9sym() ld.Cflush() sym := ld.Linklookup(ld.Ctxt, "pclntab", 0) if sym != nil { ld.Lcsize = int32(len(sym.P)) for i := 0; int32(i) < ld.Lcsize; i++ { ld.Cput(sym.P[i]) } ld.Cflush() } case obj.Hwindows: if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f dwarf\n", obj.Cputime()) } case obj.Hdarwin: if ld.Linkmode == ld.LinkExternal { ld.Machoemitreloc() } } } if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f headr\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(0) switch ld.HEADTYPE { default: case obj.Hplan9: /* plan9 */ magic := int32(4*11*11 + 7) ld.Lputb(uint32(magic)) /* magic */ ld.Lputb(uint32(ld.Segtext.Filelen)) /* sizes */ ld.Lputb(uint32(ld.Segdata.Filelen)) ld.Lputb(uint32(ld.Segdata.Length - ld.Segdata.Filelen)) ld.Lputb(uint32(ld.Symsize)) /* nsyms */ ld.Lputb(uint32(ld.Entryvalue())) /* va of entry */ ld.Lputb(uint32(ld.Spsize)) /* sp offsets */ ld.Lputb(uint32(ld.Lcsize)) /* line offsets */ case obj.Hdarwin: ld.Asmbmacho() case obj.Hlinux, obj.Hfreebsd, obj.Hnetbsd, obj.Hopenbsd, obj.Hnacl: ld.Asmbelf(int64(symo)) case obj.Hwindows: ld.Asmbpe() } ld.Cflush() }
func asmb() { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f asmb\n", obj.Cputime()) } ld.Bso.Flush() if ld.Iself { ld.Asmbelfsetup() } sect := ld.Segtext.Sect ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) ld.Codeblk(int64(sect.Vaddr), int64(sect.Length)) for sect = sect.Next; sect != nil; sect = sect.Next { ld.Cseek(int64(sect.Vaddr - ld.Segtext.Vaddr + ld.Segtext.Fileoff)) ld.Datblk(int64(sect.Vaddr), int64(sect.Length)) } if ld.Segrodata.Filelen > 0 { if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f rodatblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segrodata.Fileoff)) ld.Datblk(int64(ld.Segrodata.Vaddr), int64(ld.Segrodata.Filelen)) } if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f datblk\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(int64(ld.Segdata.Fileoff)) ld.Datblk(int64(ld.Segdata.Vaddr), int64(ld.Segdata.Filelen)) ld.Cseek(int64(ld.Segdwarf.Fileoff)) ld.Dwarfblk(int64(ld.Segdwarf.Vaddr), int64(ld.Segdwarf.Filelen)) /* output symbol table */ ld.Symsize = 0 ld.Lcsize = 0 symo := uint32(0) if ld.Debug['s'] == 0 { if !ld.Iself { ld.Diag("unsupported executable format") } if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f sym\n", obj.Cputime()) } ld.Bso.Flush() symo = uint32(ld.Segdwarf.Fileoff + ld.Segdwarf.Filelen) symo = uint32(ld.Rnd(int64(symo), int64(ld.INITRND))) ld.Cseek(int64(symo)) if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f elfsym\n", obj.Cputime()) } ld.Asmelfsym() ld.Cflush() ld.Cwrite(ld.Elfstrdat) if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f dwarf\n", obj.Cputime()) } if ld.Linkmode == ld.LinkExternal { ld.Elfemitreloc() } } ld.Ctxt.Cursym = nil if ld.Debug['v'] != 0 { fmt.Fprintf(ld.Bso, "%5.2f header\n", obj.Cputime()) } ld.Bso.Flush() ld.Cseek(0) switch ld.HEADTYPE { default: ld.Diag("unsupported operating system") case obj.Hlinux: ld.Asmbelf(int64(symo)) } ld.Cflush() if ld.Debug['c'] != 0 { fmt.Printf("textsize=%d\n", ld.Segtext.Filelen) fmt.Printf("datsize=%d\n", ld.Segdata.Filelen) fmt.Printf("bsssize=%d\n", ld.Segdata.Length-ld.Segdata.Filelen) fmt.Printf("symsize=%d\n", ld.Symsize) fmt.Printf("lcsize=%d\n", ld.Lcsize) fmt.Printf("total=%d\n", ld.Segtext.Filelen+ld.Segdata.Length+uint64(ld.Symsize)+uint64(ld.Lcsize)) } }
// deadcode marks all reachable symbols. // // The basis of the dead code elimination is a flood fill of symbols, // following their relocations, beginning at INITENTRY. // // This flood fill is wrapped in logic for pruning unused methods. // All methods are mentioned by relocations on their receiver's *rtype. // These relocations are specially defined as R_METHODOFF by the compiler // so we can detect and manipulated them here. // // There are three ways a method of a reachable type can be invoked: // // 1. direct call // 2. through a reachable interface type // 3. reflect.Value.Call, .Method, or reflect.Method.Func // // The first case is handled by the flood fill, a directly called method // is marked as reachable. // // The second case is handled by decomposing all reachable interface // types into method signatures. Each encountered method is compared // against the interface method signatures, if it matches it is marked // as reachable. This is extremely conservative, but easy and correct. // // The third case is handled by looking to see if any of: // - reflect.Value.Call is reachable // - reflect.Value.Method is reachable // - reflect.Type.Method or MethodByName is called. // If any of these happen, all bets are off and all exported methods // of reachable types are marked reachable. // // Any unreached text symbols are removed from ctxt.Textp. func deadcode(ctxt *Link) { if Debug['v'] != 0 { fmt.Fprintf(ctxt.Bso, "%5.2f deadcode\n", obj.Cputime()) } d := &deadcodepass{ ctxt: ctxt, ifaceMethod: make(map[methodsig]bool), } // First, flood fill any symbols directly reachable in the call // graph from INITENTRY. Ignore all methods not directly called. d.init() d.flood() callSym := Linkrlookup(ctxt, "reflect.Value.Call", 0) methSym := Linkrlookup(ctxt, "reflect.Value.Method", 0) reflectSeen := false if DynlinkingGo() { // Exported methods may satisfy interfaces we don't know // about yet when dynamically linking. reflectSeen = true } for { if !reflectSeen { if d.reflectMethod || (callSym != nil && callSym.Attr.Reachable()) || (methSym != nil && methSym.Attr.Reachable()) { // Methods might be called via reflection. Give up on // static analysis, mark all exported methods of // all reachable types as reachable. reflectSeen = true } } // Mark all methods that could satisfy a discovered // interface as reachable. We recheck old marked interfaces // as new types (with new methods) may have been discovered // in the last pass. var rem []methodref for _, m := range d.markableMethods { if (reflectSeen && m.isExported()) || d.ifaceMethod[m.m] { d.markMethod(m) } else { rem = append(rem, m) } } d.markableMethods = rem if len(d.markQueue) == 0 { // No new work was discovered. Done. break } d.flood() } // Remove all remaining unreached R_METHODOFF relocations. for _, m := range d.markableMethods { for _, r := range m.r { d.cleanupReloc(r) } } if Buildmode != BuildmodeShared { // Keep a typelink or itablink if the symbol it points at is being kept. // (When BuildmodeShared, always keep typelinks and itablinks.) for _, s := range ctxt.Allsym { if strings.HasPrefix(s.Name, "go.typelink.") || strings.HasPrefix(s.Name, "go.itablink.") { s.Attr.Set(AttrReachable, len(s.R) == 1 && s.R[0].Sym.Attr.Reachable()) } } } // Remove dead text but keep file information (z symbols). textp := make([]*LSym, 0, len(ctxt.Textp)) for _, s := range ctxt.Textp { if s.Attr.Reachable() { textp = append(textp, s) } } ctxt.Textp = textp }
func preprocess(ctxt *obj.Link, cursym *obj.LSym) { // TODO(minux): add morestack short-cuts with small fixed frame-size. ctxt.Cursym = cursym if cursym.Text == nil || cursym.Text.Link == nil { return } p := cursym.Text textstksiz := p.To.Offset if textstksiz == -8 { // Compatibility hack. p.From3.Offset |= obj.NOFRAME textstksiz = 0 } if textstksiz%8 != 0 { ctxt.Diag("frame size %d not a multiple of 8", textstksiz) } if p.From3.Offset&obj.NOFRAME != 0 { if textstksiz != 0 { ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz) } } cursym.Args = p.To.Val.(int32) cursym.Locals = int32(textstksiz) /* * find leaf subroutines * strip NOPs * expand RET * expand BECOME pseudo */ if ctxt.Debugvlog != 0 { fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime()) } ctxt.Bso.Flush() var q *obj.Prog var q1 *obj.Prog for p := cursym.Text; p != nil; p = p.Link { switch p.As { /* too hard, just leave alone */ case obj.ATEXT: q = p p.Mark |= LABEL | LEAF | SYNC if p.Link != nil { p.Link.Mark |= LABEL } case ANOR: q = p if p.To.Type == obj.TYPE_REG { if p.To.Reg == REGZERO { p.Mark |= LABEL | SYNC } } case ASYNC, AWORD: q = p p.Mark |= LABEL | SYNC continue case AMOVW, AMOVWZ, AMOVD: q = p if p.From.Reg >= REG_RESERVED || p.To.Reg >= REG_RESERVED { p.Mark |= LABEL | SYNC } continue case AFABS, AFADD, AFDIV, AFMADD, AFMOVD, AFMOVS, AFMSUB, AFMUL, AFNABS, AFNEG, AFNMADD, AFNMSUB, ALEDBR, ALDEBR, AFSUB: q = p p.Mark |= FLOAT continue case ABL, ABCL, obj.ADUFFZERO, obj.ADUFFCOPY: cursym.Text.Mark &^= LEAF fallthrough case ABC, ABEQ, ABGE, ABGT, ABLE, ABLT, ABNE, ABR, ABVC, ABVS, ACMPBEQ, ACMPBGE, ACMPBGT, ACMPBLE, ACMPBLT, ACMPBNE, ACMPUBEQ, ACMPUBGE, ACMPUBGT, ACMPUBLE, ACMPUBLT, ACMPUBNE: p.Mark |= BRANCH q = p q1 = p.Pcond if q1 != nil { for q1.As == obj.ANOP { q1 = q1.Link p.Pcond = q1 } if q1.Mark&LEAF == 0 { q1.Mark |= LABEL } } else { p.Mark |= LABEL } q1 = p.Link if q1 != nil { q1.Mark |= LABEL } continue case AFCMPO, AFCMPU: q = p p.Mark |= FCMP | FLOAT continue case obj.ARET: q = p if p.Link != nil { p.Link.Mark |= LABEL } continue case obj.ANOP: q1 = p.Link q.Link = q1 /* q is non-nop */ q1.Mark |= p.Mark continue default: q = p continue } } autosize := int32(0) var p1 *obj.Prog var p2 *obj.Prog var pLast *obj.Prog var pPre *obj.Prog var pPreempt *obj.Prog wasSplit := false for p := cursym.Text; p != nil; p = p.Link { pLast = p switch p.As { case obj.ATEXT: autosize = int32(textstksiz) if p.Mark&LEAF != 0 && autosize == 0 && p.From3.Offset&obj.NOFRAME == 0 { // A leaf function with no locals has no frame. p.From3.Offset |= obj.NOFRAME } if p.From3.Offset&obj.NOFRAME == 0 { // If there is a stack frame at all, it includes // space to save the LR. autosize += int32(ctxt.FixedFrameSize()) } p.To.Offset = int64(autosize) q = p if p.From3.Offset&obj.NOSPLIT == 0 { p, pPreempt = stacksplitPre(ctxt, p, autosize) // emit pre part of split check pPre = p wasSplit = true //need post part of split } if autosize != 0 { q = obj.Appendp(ctxt, p) q.As = AMOVD q.From.Type = obj.TYPE_ADDR q.From.Offset = int64(-autosize) q.From.Reg = REGSP // not actually needed - REGSP is assumed if no reg is provided q.To.Type = obj.TYPE_REG q.To.Reg = REGSP q.Spadj = autosize } else if cursym.Text.Mark&LEAF == 0 { // A very few functions that do not return to their caller // (e.g. gogo) are not identified as leaves but still have // no frame. cursym.Text.Mark |= LEAF } if cursym.Text.Mark&LEAF != 0 { cursym.Leaf = true break } q = obj.Appendp(ctxt, q) q.As = AMOVD q.From.Type = obj.TYPE_REG q.From.Reg = REG_LR q.To.Type = obj.TYPE_MEM q.To.Reg = REGSP q.To.Offset = 0 if cursym.Text.From3.Offset&obj.WRAPPER != 0 { // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame // // MOVD g_panic(g), R3 // CMP R0, R3 // BEQ end // MOVD panic_argp(R3), R4 // ADD $(autosize+8), R1, R5 // CMP R4, R5 // BNE end // ADD $8, R1, R6 // MOVD R6, panic_argp(R3) // end: // NOP // // The NOP is needed to give the jumps somewhere to land. // It is a liblink NOP, not a s390x NOP: it encodes to 0 instruction bytes. q = obj.Appendp(ctxt, q) q.As = AMOVD q.From.Type = obj.TYPE_MEM q.From.Reg = REGG q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic q.To.Type = obj.TYPE_REG q.To.Reg = REG_R3 q = obj.Appendp(ctxt, q) q.As = ACMP q.From.Type = obj.TYPE_REG q.From.Reg = REG_R0 q.To.Type = obj.TYPE_REG q.To.Reg = REG_R3 q = obj.Appendp(ctxt, q) q.As = ABEQ q.To.Type = obj.TYPE_BRANCH p1 = q q = obj.Appendp(ctxt, q) q.As = AMOVD q.From.Type = obj.TYPE_MEM q.From.Reg = REG_R3 q.From.Offset = 0 // Panic.argp q.To.Type = obj.TYPE_REG q.To.Reg = REG_R4 q = obj.Appendp(ctxt, q) q.As = AADD q.From.Type = obj.TYPE_CONST q.From.Offset = int64(autosize) + ctxt.FixedFrameSize() q.Reg = REGSP q.To.Type = obj.TYPE_REG q.To.Reg = REG_R5 q = obj.Appendp(ctxt, q) q.As = ACMP q.From.Type = obj.TYPE_REG q.From.Reg = REG_R4 q.To.Type = obj.TYPE_REG q.To.Reg = REG_R5 q = obj.Appendp(ctxt, q) q.As = ABNE q.To.Type = obj.TYPE_BRANCH p2 = q q = obj.Appendp(ctxt, q) q.As = AADD q.From.Type = obj.TYPE_CONST q.From.Offset = ctxt.FixedFrameSize() q.Reg = REGSP q.To.Type = obj.TYPE_REG q.To.Reg = REG_R6 q = obj.Appendp(ctxt, q) q.As = AMOVD q.From.Type = obj.TYPE_REG q.From.Reg = REG_R6 q.To.Type = obj.TYPE_MEM q.To.Reg = REG_R3 q.To.Offset = 0 // Panic.argp q = obj.Appendp(ctxt, q) q.As = obj.ANOP p1.Pcond = q p2.Pcond = q } case obj.ARET: if p.From.Type == obj.TYPE_CONST { ctxt.Diag("using BECOME (%v) is not supported!", p) break } retTarget := p.To.Sym if cursym.Text.Mark&LEAF != 0 { if autosize == 0 { p.As = ABR p.From = obj.Addr{} if retTarget == nil { p.To.Type = obj.TYPE_REG p.To.Reg = REG_LR } else { p.To.Type = obj.TYPE_BRANCH p.To.Sym = retTarget } p.Mark |= BRANCH break } p.As = AADD p.From.Type = obj.TYPE_CONST p.From.Offset = int64(autosize) p.To.Type = obj.TYPE_REG p.To.Reg = REGSP p.Spadj = -autosize q = obj.Appendp(ctxt, p) q.As = ABR q.From = obj.Addr{} q.To.Type = obj.TYPE_REG q.To.Reg = REG_LR q.Mark |= BRANCH q.Spadj = autosize break } p.As = AMOVD p.From.Type = obj.TYPE_MEM p.From.Reg = REGSP p.From.Offset = 0 p.To.Type = obj.TYPE_REG p.To.Reg = REG_LR q = p if autosize != 0 { q = obj.Appendp(ctxt, q) q.As = AADD q.From.Type = obj.TYPE_CONST q.From.Offset = int64(autosize) q.To.Type = obj.TYPE_REG q.To.Reg = REGSP q.Spadj = -autosize } q = obj.Appendp(ctxt, q) q.As = ABR q.From = obj.Addr{} if retTarget == nil { q.To.Type = obj.TYPE_REG q.To.Reg = REG_LR } else { q.To.Type = obj.TYPE_BRANCH q.To.Sym = retTarget } q.Mark |= BRANCH q.Spadj = autosize case AADD: if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST { p.Spadj = int32(-p.From.Offset) } } } if wasSplit { pLast = stacksplitPost(ctxt, pLast, pPre, pPreempt) // emit post part of split check } }
func ldpe(f *bio.Reader, pkg string, length int64, pn string) { if Debug['v'] != 0 { fmt.Fprintf(Bso, "%5.2f ldpe %s\n", obj.Cputime(), pn) } var sect *PeSect Ctxt.IncVersion() base := f.Offset() peobj := new(PeObj) peobj.f = f peobj.base = uint32(base) peobj.name = pn // read header var err error var j int var l uint32 var name string var numaux int var r []Reloc var rp *Reloc var rsect *PeSect var s *LSym var sym *PeSym var symbuf [18]uint8 if err = binary.Read(f, binary.LittleEndian, &peobj.fh); err != nil { goto bad } // load section list peobj.sect = make([]PeSect, peobj.fh.NumberOfSections) peobj.nsect = uint(peobj.fh.NumberOfSections) for i := 0; i < int(peobj.fh.NumberOfSections); i++ { if err = binary.Read(f, binary.LittleEndian, &peobj.sect[i].sh); err != nil { goto bad } peobj.sect[i].size = uint64(peobj.sect[i].sh.SizeOfRawData) peobj.sect[i].name = cstring(peobj.sect[i].sh.Name[:]) } // TODO return error if found .cormeta // load string table f.Seek(base+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(peobj.fh.NumberOfSymbols), 0) if _, err := io.ReadFull(f, symbuf[:4]); err != nil { goto bad } l = Le32(symbuf[:]) peobj.snames = make([]byte, l) f.Seek(base+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(peobj.fh.NumberOfSymbols), 0) if _, err := io.ReadFull(f, peobj.snames); err != nil { goto bad } // rewrite section names if they start with / for i := 0; i < int(peobj.fh.NumberOfSections); i++ { if peobj.sect[i].name == "" { continue } if peobj.sect[i].name[0] != '/' { continue } n, _ := strconv.Atoi(peobj.sect[i].name[1:]) peobj.sect[i].name = cstring(peobj.snames[n:]) } // read symbols peobj.pesym = make([]PeSym, peobj.fh.NumberOfSymbols) peobj.npesym = uint(peobj.fh.NumberOfSymbols) f.Seek(base+int64(peobj.fh.PointerToSymbolTable), 0) for i := 0; uint32(i) < peobj.fh.NumberOfSymbols; i += numaux + 1 { f.Seek(base+int64(peobj.fh.PointerToSymbolTable)+int64(len(symbuf))*int64(i), 0) if _, err := io.ReadFull(f, symbuf[:]); err != nil { goto bad } if (symbuf[0] == 0) && (symbuf[1] == 0) && (symbuf[2] == 0) && (symbuf[3] == 0) { l = Le32(symbuf[4:]) peobj.pesym[i].name = cstring(peobj.snames[l:]) // sym name length <= 8 } else { peobj.pesym[i].name = cstring(symbuf[:8]) } peobj.pesym[i].value = Le32(symbuf[8:]) peobj.pesym[i].sectnum = Le16(symbuf[12:]) peobj.pesym[i].sclass = symbuf[16] peobj.pesym[i].aux = symbuf[17] peobj.pesym[i].type_ = Le16(symbuf[14:]) numaux = int(peobj.pesym[i].aux) if numaux < 0 { numaux = 0 } } // create symbols for mapped sections for i := 0; uint(i) < peobj.nsect; i++ { sect = &peobj.sect[i] if sect.sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { continue } if sect.sh.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { // This has been seen for .idata sections, which we // want to ignore. See issues 5106 and 5273. continue } if pemap(peobj, sect) < 0 { goto bad } name = fmt.Sprintf("%s(%s)", pkg, sect.name) s = Linklookup(Ctxt, name, Ctxt.Version) switch sect.sh.Characteristics & (IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE | IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE) { case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ: //.rdata s.Type = obj.SRODATA case IMAGE_SCN_CNT_UNINITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.bss s.Type = obj.SNOPTRBSS case IMAGE_SCN_CNT_INITIALIZED_DATA | IMAGE_SCN_MEM_READ | IMAGE_SCN_MEM_WRITE: //.data s.Type = obj.SNOPTRDATA case IMAGE_SCN_CNT_CODE | IMAGE_SCN_MEM_EXECUTE | IMAGE_SCN_MEM_READ: //.text s.Type = obj.STEXT default: err = fmt.Errorf("unexpected flags %#06x for PE section %s", sect.sh.Characteristics, sect.name) goto bad } s.P = sect.base s.P = s.P[:sect.size] s.Size = int64(sect.size) sect.sym = s if sect.name == ".rsrc" { setpersrc(sect.sym) } } // load relocations for i := 0; uint(i) < peobj.nsect; i++ { rsect = &peobj.sect[i] if rsect.sym == nil || rsect.sh.NumberOfRelocations == 0 { continue } if rsect.sh.Characteristics&IMAGE_SCN_MEM_DISCARDABLE != 0 { continue } if sect.sh.Characteristics&(IMAGE_SCN_CNT_CODE|IMAGE_SCN_CNT_INITIALIZED_DATA|IMAGE_SCN_CNT_UNINITIALIZED_DATA) == 0 { // This has been seen for .idata sections, which we // want to ignore. See issues 5106 and 5273. continue } r = make([]Reloc, rsect.sh.NumberOfRelocations) f.Seek(int64(peobj.base)+int64(rsect.sh.PointerToRelocations), 0) for j = 0; j < int(rsect.sh.NumberOfRelocations); j++ { rp = &r[j] if _, err := io.ReadFull(f, symbuf[:10]); err != nil { goto bad } rva := Le32(symbuf[0:]) symindex := Le32(symbuf[4:]) type_ := Le16(symbuf[8:]) if err = readpesym(peobj, int(symindex), &sym); err != nil { goto bad } if sym.sym == nil { err = fmt.Errorf("reloc of invalid sym %s idx=%d type=%d", sym.name, symindex, sym.type_) goto bad } rp.Sym = sym.sym rp.Siz = 4 rp.Off = int32(rva) switch type_ { default: Diag("%s: unknown relocation type %d;", pn, type_) fallthrough case IMAGE_REL_I386_REL32, IMAGE_REL_AMD64_REL32, IMAGE_REL_AMD64_ADDR32, // R_X86_64_PC32 IMAGE_REL_AMD64_ADDR32NB: rp.Type = obj.R_PCREL rp.Add = int64(int32(Le32(rsect.base[rp.Off:]))) case IMAGE_REL_I386_DIR32NB, IMAGE_REL_I386_DIR32: rp.Type = obj.R_ADDR // load addend from image rp.Add = int64(int32(Le32(rsect.base[rp.Off:]))) case IMAGE_REL_AMD64_ADDR64: // R_X86_64_64 rp.Siz = 8 rp.Type = obj.R_ADDR // load addend from image rp.Add = int64(Le64(rsect.base[rp.Off:])) } // ld -r could generate multiple section symbols for the // same section but with different values, we have to take // that into account if issect(&peobj.pesym[symindex]) { rp.Add += int64(peobj.pesym[symindex].value) } } sort.Sort(rbyoff(r[:rsect.sh.NumberOfRelocations])) s = rsect.sym s.R = r s.R = s.R[:rsect.sh.NumberOfRelocations] } // enter sub-symbols into symbol table. for i := 0; uint(i) < peobj.npesym; i++ { if peobj.pesym[i].name == "" { continue } if issect(&peobj.pesym[i]) { continue } if uint(peobj.pesym[i].sectnum) > peobj.nsect { continue } if peobj.pesym[i].sectnum > 0 { sect = &peobj.sect[peobj.pesym[i].sectnum-1] if sect.sym == nil { continue } } if err = readpesym(peobj, i, &sym); err != nil { goto bad } s = sym.sym if sym.sectnum == 0 { // extern if s.Type == obj.SDYNIMPORT { s.Plt = -2 // flag for dynimport in PE object files. } if s.Type == obj.SXREF && sym.value > 0 { // global data s.Type = obj.SNOPTRDATA s.Size = int64(sym.value) } continue } else if sym.sectnum > 0 && uint(sym.sectnum) <= peobj.nsect { sect = &peobj.sect[sym.sectnum-1] if sect.sym == nil { Diag("%s: %s sym == 0!", pn, s.Name) } } else { Diag("%s: %s sectnum < 0!", pn, s.Name) } if sect == nil { return } if s.Outer != nil { if s.Attr.DuplicateOK() { continue } Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sect.sym.Name) } s.Sub = sect.sym.Sub sect.sym.Sub = s s.Type = sect.sym.Type | obj.SSUB s.Value = int64(sym.value) s.Size = 4 s.Outer = sect.sym if sect.sym.Type == obj.STEXT { if s.Attr.External() && !s.Attr.DuplicateOK() { Diag("%s: duplicate definition of %s", pn, s.Name) } s.Attr |= AttrExternal } } // Sort outer lists by address, adding to textp. // This keeps textp in increasing address order. for i := 0; uint(i) < peobj.nsect; i++ { s = peobj.sect[i].sym if s == nil { continue } if s.Sub != nil { s.Sub = listsort(s.Sub, valuecmp, listsubp) } if s.Type == obj.STEXT { if s.Attr.OnList() { log.Fatalf("symbol %s listed multiple times", s.Name) } s.Attr |= AttrOnList Ctxt.Textp = append(Ctxt.Textp, s) for s = s.Sub; s != nil; s = s.Sub { if s.Attr.OnList() { log.Fatalf("symbol %s listed multiple times", s.Name) } s.Attr |= AttrOnList Ctxt.Textp = append(Ctxt.Textp, s) } } } return bad: Diag("%s: malformed pe file: %v", pn, err) }
func ldelf(f *bio.Reader, pkg string, length int64, pn string) { if Debug['v'] != 0 { fmt.Fprintf(Bso, "%5.2f ldelf %s\n", obj.Cputime(), pn) } Ctxt.IncVersion() base := f.Offset() var add uint64 var e binary.ByteOrder var elfobj *ElfObj var err error var flag int var hdr *ElfHdrBytes var hdrbuf [64]uint8 var info uint64 var is64 int var j int var n int var name string var p []byte var r []Reloc var rela int var rp *Reloc var rsect *ElfSect var s *LSym var sect *ElfSect var sym ElfSym var symbols []*LSym if _, err := io.ReadFull(f, hdrbuf[:]); err != nil { goto bad } hdr = new(ElfHdrBytes) binary.Read(bytes.NewReader(hdrbuf[:]), binary.BigEndian, hdr) // only byte arrays; byte order doesn't matter if string(hdr.Ident[:4]) != "\x7FELF" { goto bad } switch hdr.Ident[5] { case ElfDataLsb: e = binary.LittleEndian case ElfDataMsb: e = binary.BigEndian default: goto bad } // read header elfobj = new(ElfObj) elfobj.e = e elfobj.f = f elfobj.base = base elfobj.length = length elfobj.name = pn is64 = 0 if hdr.Ident[4] == ElfClass64 { is64 = 1 hdr := new(ElfHdrBytes64) binary.Read(bytes.NewReader(hdrbuf[:]), binary.BigEndian, hdr) // only byte arrays; byte order doesn't matter elfobj.type_ = uint32(e.Uint16(hdr.Type[:])) elfobj.machine = uint32(e.Uint16(hdr.Machine[:])) elfobj.version = e.Uint32(hdr.Version[:]) elfobj.phoff = e.Uint64(hdr.Phoff[:]) elfobj.shoff = e.Uint64(hdr.Shoff[:]) elfobj.flags = e.Uint32(hdr.Flags[:]) elfobj.ehsize = uint32(e.Uint16(hdr.Ehsize[:])) elfobj.phentsize = uint32(e.Uint16(hdr.Phentsize[:])) elfobj.phnum = uint32(e.Uint16(hdr.Phnum[:])) elfobj.shentsize = uint32(e.Uint16(hdr.Shentsize[:])) elfobj.shnum = uint32(e.Uint16(hdr.Shnum[:])) elfobj.shstrndx = uint32(e.Uint16(hdr.Shstrndx[:])) } else { elfobj.type_ = uint32(e.Uint16(hdr.Type[:])) elfobj.machine = uint32(e.Uint16(hdr.Machine[:])) elfobj.version = e.Uint32(hdr.Version[:]) elfobj.entry = uint64(e.Uint32(hdr.Entry[:])) elfobj.phoff = uint64(e.Uint32(hdr.Phoff[:])) elfobj.shoff = uint64(e.Uint32(hdr.Shoff[:])) elfobj.flags = e.Uint32(hdr.Flags[:]) elfobj.ehsize = uint32(e.Uint16(hdr.Ehsize[:])) elfobj.phentsize = uint32(e.Uint16(hdr.Phentsize[:])) elfobj.phnum = uint32(e.Uint16(hdr.Phnum[:])) elfobj.shentsize = uint32(e.Uint16(hdr.Shentsize[:])) elfobj.shnum = uint32(e.Uint16(hdr.Shnum[:])) elfobj.shstrndx = uint32(e.Uint16(hdr.Shstrndx[:])) } elfobj.is64 = is64 if uint32(hdr.Ident[6]) != elfobj.version { goto bad } if e.Uint16(hdr.Type[:]) != ElfTypeRelocatable { Diag("%s: elf but not elf relocatable object", pn) return } switch SysArch.Family { default: Diag("%s: elf %s unimplemented", pn, SysArch.Name) return case sys.MIPS64: if elfobj.machine != ElfMachMips || hdr.Ident[4] != ElfClass64 { Diag("%s: elf object but not mips64", pn) return } case sys.ARM: if e != binary.LittleEndian || elfobj.machine != ElfMachArm || hdr.Ident[4] != ElfClass32 { Diag("%s: elf object but not arm", pn) return } case sys.AMD64: if e != binary.LittleEndian || elfobj.machine != ElfMachAmd64 || hdr.Ident[4] != ElfClass64 { Diag("%s: elf object but not amd64", pn) return } case sys.ARM64: if e != binary.LittleEndian || elfobj.machine != ElfMachArm64 || hdr.Ident[4] != ElfClass64 { Diag("%s: elf object but not arm64", pn) return } case sys.I386: if e != binary.LittleEndian || elfobj.machine != ElfMach386 || hdr.Ident[4] != ElfClass32 { Diag("%s: elf object but not 386", pn) return } case sys.PPC64: if elfobj.machine != ElfMachPower64 || hdr.Ident[4] != ElfClass64 { Diag("%s: elf object but not ppc64", pn) return } case sys.S390X: if elfobj.machine != ElfMachS390 || hdr.Ident[4] != ElfClass64 { Diag("%s: elf object but not s390x", pn) return } } // load section list into memory. elfobj.sect = make([]ElfSect, elfobj.shnum) elfobj.nsect = uint(elfobj.shnum) for i := 0; uint(i) < elfobj.nsect; i++ { if f.Seek(int64(uint64(base)+elfobj.shoff+uint64(int64(i)*int64(elfobj.shentsize))), 0) < 0 { goto bad } sect = &elfobj.sect[i] if is64 != 0 { var b ElfSectBytes64 if err = binary.Read(f, e, &b); err != nil { goto bad } sect.nameoff = e.Uint32(b.Name[:]) sect.type_ = e.Uint32(b.Type[:]) sect.flags = e.Uint64(b.Flags[:]) sect.addr = e.Uint64(b.Addr[:]) sect.off = e.Uint64(b.Off[:]) sect.size = e.Uint64(b.Size[:]) sect.link = e.Uint32(b.Link[:]) sect.info = e.Uint32(b.Info[:]) sect.align = e.Uint64(b.Align[:]) sect.entsize = e.Uint64(b.Entsize[:]) } else { var b ElfSectBytes if err = binary.Read(f, e, &b); err != nil { goto bad } sect.nameoff = e.Uint32(b.Name[:]) sect.type_ = e.Uint32(b.Type[:]) sect.flags = uint64(e.Uint32(b.Flags[:])) sect.addr = uint64(e.Uint32(b.Addr[:])) sect.off = uint64(e.Uint32(b.Off[:])) sect.size = uint64(e.Uint32(b.Size[:])) sect.link = e.Uint32(b.Link[:]) sect.info = e.Uint32(b.Info[:]) sect.align = uint64(e.Uint32(b.Align[:])) sect.entsize = uint64(e.Uint32(b.Entsize[:])) } } // read section string table and translate names if elfobj.shstrndx >= uint32(elfobj.nsect) { err = fmt.Errorf("shstrndx out of range %d >= %d", elfobj.shstrndx, elfobj.nsect) goto bad } sect = &elfobj.sect[elfobj.shstrndx] if err = elfmap(elfobj, sect); err != nil { goto bad } for i := 0; uint(i) < elfobj.nsect; i++ { if elfobj.sect[i].nameoff != 0 { elfobj.sect[i].name = cstring(sect.base[elfobj.sect[i].nameoff:]) } } // load string table for symbols into memory. elfobj.symtab = section(elfobj, ".symtab") if elfobj.symtab == nil { // our work is done here - no symbols means nothing can refer to this file return } if elfobj.symtab.link <= 0 || elfobj.symtab.link >= uint32(elfobj.nsect) { Diag("%s: elf object has symbol table with invalid string table link", pn) return } elfobj.symstr = &elfobj.sect[elfobj.symtab.link] if is64 != 0 { elfobj.nsymtab = int(elfobj.symtab.size / ELF64SYMSIZE) } else { elfobj.nsymtab = int(elfobj.symtab.size / ELF32SYMSIZE) } if err = elfmap(elfobj, elfobj.symtab); err != nil { goto bad } if err = elfmap(elfobj, elfobj.symstr); err != nil { goto bad } // load text and data segments into memory. // they are not as small as the section lists, but we'll need // the memory anyway for the symbol images, so we might // as well use one large chunk. // create symbols for elfmapped sections for i := 0; uint(i) < elfobj.nsect; i++ { sect = &elfobj.sect[i] if sect.type_ == SHT_ARM_ATTRIBUTES && sect.name == ".ARM.attributes" { if err = elfmap(elfobj, sect); err != nil { goto bad } parseArmAttributes(e, sect.base[:sect.size]) } if (sect.type_ != ElfSectProgbits && sect.type_ != ElfSectNobits) || sect.flags&ElfSectFlagAlloc == 0 { continue } if sect.type_ != ElfSectNobits { if err = elfmap(elfobj, sect); err != nil { goto bad } } name = fmt.Sprintf("%s(%s)", pkg, sect.name) s = Linklookup(Ctxt, name, Ctxt.Version) switch int(sect.flags) & (ElfSectFlagAlloc | ElfSectFlagWrite | ElfSectFlagExec) { default: err = fmt.Errorf("unexpected flags for ELF section %s", sect.name) goto bad case ElfSectFlagAlloc: s.Type = obj.SRODATA case ElfSectFlagAlloc + ElfSectFlagWrite: if sect.type_ == ElfSectNobits { s.Type = obj.SNOPTRBSS } else { s.Type = obj.SNOPTRDATA } case ElfSectFlagAlloc + ElfSectFlagExec: s.Type = obj.STEXT } if sect.name == ".got" || sect.name == ".toc" { s.Type = obj.SELFGOT } if sect.type_ == ElfSectProgbits { s.P = sect.base s.P = s.P[:sect.size] } s.Size = int64(sect.size) s.Align = int32(sect.align) sect.sym = s } // enter sub-symbols into symbol table. // symbol 0 is the null symbol. symbols = make([]*LSym, elfobj.nsymtab) for i := 1; i < elfobj.nsymtab; i++ { if err = readelfsym(elfobj, i, &sym, 1); err != nil { goto bad } symbols[i] = sym.sym if sym.type_ != ElfSymTypeFunc && sym.type_ != ElfSymTypeObject && sym.type_ != ElfSymTypeNone { continue } if sym.shndx == ElfSymShnCommon { s = sym.sym if uint64(s.Size) < sym.size { s.Size = int64(sym.size) } if s.Type == 0 || s.Type == obj.SXREF { s.Type = obj.SNOPTRBSS } continue } if uint(sym.shndx) >= elfobj.nsect || sym.shndx == 0 { continue } // even when we pass needSym == 1 to readelfsym, it might still return nil to skip some unwanted symbols if sym.sym == nil { continue } sect = &elfobj.sect[sym.shndx] if sect.sym == nil { if strings.HasPrefix(sym.name, ".Linfo_string") { // clang does this continue } if sym.name == "" && sym.type_ == 0 && sect.name == ".debug_str" { // This reportedly happens with clang 3.7 on ARM. // See issue 13139. continue } if strings.HasPrefix(sym.name, ".LASF") { // gcc on s390x does this continue } Diag("%s: sym#%d: ignoring %s in section %d (type %d)", pn, i, sym.name, sym.shndx, sym.type_) continue } s = sym.sym if s.Outer != nil { if s.Attr.DuplicateOK() { continue } Exitf("%s: duplicate symbol reference: %s in both %s and %s", pn, s.Name, s.Outer.Name, sect.sym.Name) } s.Sub = sect.sym.Sub sect.sym.Sub = s s.Type = sect.sym.Type | s.Type&^obj.SMASK | obj.SSUB if !s.Attr.CgoExportDynamic() { s.Dynimplib = "" // satisfy dynimport } s.Value = int64(sym.value) s.Size = int64(sym.size) s.Outer = sect.sym if sect.sym.Type == obj.STEXT { if s.Attr.External() && !s.Attr.DuplicateOK() { Diag("%s: duplicate definition of %s", pn, s.Name) } s.Attr |= AttrExternal } if elfobj.machine == ElfMachPower64 { flag = int(sym.other) >> 5 if 2 <= flag && flag <= 6 { s.Localentry = 1 << uint(flag-2) } else if flag == 7 { Diag("%s: invalid sym.other 0x%x for %s", pn, sym.other, s.Name) } } } // Sort outer lists by address, adding to textp. // This keeps textp in increasing address order. for i := 0; uint(i) < elfobj.nsect; i++ { s = elfobj.sect[i].sym if s == nil { continue } if s.Sub != nil { s.Sub = listsort(s.Sub, valuecmp, listsubp) } if s.Type == obj.STEXT { if s.Attr.OnList() { log.Fatalf("symbol %s listed multiple times", s.Name) } s.Attr |= AttrOnList Ctxt.Textp = append(Ctxt.Textp, s) for s = s.Sub; s != nil; s = s.Sub { if s.Attr.OnList() { log.Fatalf("symbol %s listed multiple times", s.Name) } s.Attr |= AttrOnList Ctxt.Textp = append(Ctxt.Textp, s) } } } // load relocations for i := 0; uint(i) < elfobj.nsect; i++ { rsect = &elfobj.sect[i] if rsect.type_ != ElfSectRela && rsect.type_ != ElfSectRel { continue } if rsect.info >= uint32(elfobj.nsect) || elfobj.sect[rsect.info].base == nil { continue } sect = &elfobj.sect[rsect.info] if err = elfmap(elfobj, rsect); err != nil { goto bad } rela = 0 if rsect.type_ == ElfSectRela { rela = 1 } n = int(rsect.size / uint64(4+4*is64) / uint64(2+rela)) r = make([]Reloc, n) p = rsect.base for j = 0; j < n; j++ { add = 0 rp = &r[j] if is64 != 0 { // 64-bit rel/rela rp.Off = int32(e.Uint64(p)) p = p[8:] info = e.Uint64(p) p = p[8:] if rela != 0 { add = e.Uint64(p) p = p[8:] } } else { // 32-bit rel/rela rp.Off = int32(e.Uint32(p)) p = p[4:] info = uint64(e.Uint32(p)) info = info>>8<<32 | info&0xff // convert to 64-bit info p = p[4:] if rela != 0 { add = uint64(e.Uint32(p)) p = p[4:] } } if info&0xffffffff == 0 { // skip R_*_NONE relocation j-- n-- continue } if info>>32 == 0 { // absolute relocation, don't bother reading the null symbol rp.Sym = nil } else { if err = readelfsym(elfobj, int(info>>32), &sym, 0); err != nil { goto bad } sym.sym = symbols[info>>32] if sym.sym == nil { err = fmt.Errorf("%s#%d: reloc of invalid sym #%d %s shndx=%d type=%d", sect.sym.Name, j, int(info>>32), sym.name, sym.shndx, sym.type_) goto bad } rp.Sym = sym.sym } rp.Type = 256 + int32(info) rp.Siz = relSize(pn, uint32(info)) if rela != 0 { rp.Add = int64(add) } else { // load addend from image if rp.Siz == 4 { rp.Add = int64(e.Uint32(sect.base[rp.Off:])) } else if rp.Siz == 8 { rp.Add = int64(e.Uint64(sect.base[rp.Off:])) } else { Diag("invalid rela size %d", rp.Siz) } } if rp.Siz == 2 { rp.Add = int64(int16(rp.Add)) } if rp.Siz == 4 { rp.Add = int64(int32(rp.Add)) } } //print("rel %s %d %d %s %#llx\n", sect->sym->name, rp->type, rp->siz, rp->sym->name, rp->add); sort.Sort(rbyoff(r[:n])) // just in case s = sect.sym s.R = r s.R = s.R[:n] } return bad: Diag("%s: malformed elf file: %v", pn, err) }
/* * add library to library list. * srcref: src file referring to package * objref: object file referring to package * file: object file, e.g., /home/rsc/go/pkg/container/vector.a * pkg: package import path, e.g. container/vector */ func addlibpath(ctxt *Link, srcref string, objref string, file string, pkg string, shlibnamefile string) { for i := 0; i < len(ctxt.Library); i++ { if pkg == ctxt.Library[i].Pkg { return } } if ctxt.Debugvlog > 1 && ctxt.Bso != nil { fmt.Fprintf(ctxt.Bso, "%5.2f addlibpath: srcref: %s objref: %s file: %s pkg: %s shlibnamefile: %s\n", obj.Cputime(), srcref, objref, file, pkg, shlibnamefile) } ctxt.Library = append(ctxt.Library, &Library{}) l := ctxt.Library[len(ctxt.Library)-1] l.Objref = objref l.Srcref = srcref l.File = file l.Pkg = pkg if shlibnamefile != "" { shlibbytes, err := ioutil.ReadFile(shlibnamefile) if err != nil { Diag("cannot read %s: %v", shlibnamefile, err) } l.Shlib = strings.TrimSpace(string(shlibbytes)) } }
func preprocess(ctxt *obj.Link, cursym *obj.LSym) { // TODO(minux): add morestack short-cuts with small fixed frame-size. ctxt.Cursym = cursym if cursym.Text == nil || cursym.Text.Link == nil { return } p := cursym.Text textstksiz := p.To.Offset if textstksiz == -8 { // Compatibility hack. p.From3.Offset |= obj.NOFRAME textstksiz = 0 } if textstksiz%8 != 0 { ctxt.Diag("frame size %d not a multiple of 8", textstksiz) } if p.From3.Offset&obj.NOFRAME != 0 { if textstksiz != 0 { ctxt.Diag("NOFRAME functions must have a frame size of 0, not %d", textstksiz) } } cursym.Args = p.To.Val.(int32) cursym.Locals = int32(textstksiz) /* * find leaf subroutines * strip NOPs * expand RET * expand BECOME pseudo */ if ctxt.Debugvlog != 0 { fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime()) } ctxt.Bso.Flush() var q *obj.Prog var q1 *obj.Prog for p := cursym.Text; p != nil; p = p.Link { switch p.As { /* too hard, just leave alone */ case obj.ATEXT: q = p p.Mark |= LABEL | LEAF | SYNC if p.Link != nil { p.Link.Mark |= LABEL } case ANOR: q = p if p.To.Type == obj.TYPE_REG { if p.To.Reg == REGZERO { p.Mark |= LABEL | SYNC } } case ALWAR, ALBAR, ASTBCCC, ASTWCCC, AECIWX, AECOWX, AEIEIO, AICBI, AISYNC, ATLBIE, ATLBIEL, ASLBIA, ASLBIE, ASLBMFEE, ASLBMFEV, ASLBMTE, ADCBF, ADCBI, ADCBST, ADCBT, ADCBTST, ADCBZ, ASYNC, ATLBSYNC, APTESYNC, ALWSYNC, ATW, AWORD, ARFI, ARFCI, ARFID, AHRFID: q = p p.Mark |= LABEL | SYNC continue case AMOVW, AMOVWZ, AMOVD: q = p if p.From.Reg >= REG_SPECIAL || p.To.Reg >= REG_SPECIAL { p.Mark |= LABEL | SYNC } continue case AFABS, AFABSCC, AFADD, AFADDCC, AFCTIW, AFCTIWCC, AFCTIWZ, AFCTIWZCC, AFDIV, AFDIVCC, AFMADD, AFMADDCC, AFMOVD, AFMOVDU, /* case AFMOVDS: */ AFMOVS, AFMOVSU, /* case AFMOVSD: */ AFMSUB, AFMSUBCC, AFMUL, AFMULCC, AFNABS, AFNABSCC, AFNEG, AFNEGCC, AFNMADD, AFNMADDCC, AFNMSUB, AFNMSUBCC, AFRSP, AFRSPCC, AFSUB, AFSUBCC: q = p p.Mark |= FLOAT continue case ABL, ABCL, obj.ADUFFZERO, obj.ADUFFCOPY: cursym.Text.Mark &^= LEAF fallthrough case ABC, ABEQ, ABGE, ABGT, ABLE, ABLT, ABNE, ABR, ABVC, ABVS: p.Mark |= BRANCH q = p q1 = p.Pcond if q1 != nil { for q1.As == obj.ANOP { q1 = q1.Link p.Pcond = q1 } if q1.Mark&LEAF == 0 { q1.Mark |= LABEL } } else { p.Mark |= LABEL } q1 = p.Link if q1 != nil { q1.Mark |= LABEL } continue case AFCMPO, AFCMPU: q = p p.Mark |= FCMP | FLOAT continue case obj.ARET: q = p if p.Link != nil { p.Link.Mark |= LABEL } continue case obj.ANOP: q1 = p.Link q.Link = q1 /* q is non-nop */ q1.Mark |= p.Mark continue default: q = p continue } } autosize := int32(0) var aoffset int var mov obj.As var p1 *obj.Prog var p2 *obj.Prog for p := cursym.Text; p != nil; p = p.Link { o := p.As switch o { case obj.ATEXT: mov = AMOVD aoffset = 0 autosize = int32(textstksiz) if p.Mark&LEAF != 0 && autosize == 0 && p.From3.Offset&obj.NOFRAME == 0 { // A leaf function with no locals has no frame. p.From3.Offset |= obj.NOFRAME } if p.From3.Offset&obj.NOFRAME == 0 { // If there is a stack frame at all, it includes // space to save the LR. autosize += int32(ctxt.FixedFrameSize()) } p.To.Offset = int64(autosize) q = p if ctxt.Flag_shared && cursym.Name != "runtime.duffzero" && cursym.Name != "runtime.duffcopy" && cursym.Name != "runtime.stackBarrier" { // When compiling Go into PIC, all functions must start // with instructions to load the TOC pointer into r2: // // addis r2, r12, .TOC.-func@ha // addi r2, r2, .TOC.-func@l+4 // // We could probably skip this prologue in some situations // but it's a bit subtle. However, it is both safe and // necessary to leave the prologue off duffzero and // duffcopy as we rely on being able to jump to a specific // instruction offset for them, and stackBarrier is only // ever called from an overwritten LR-save slot on the // stack (when r12 will not be remotely the right thing) // but fortunately does not access global data. // // These are AWORDS because there is no (afaict) way to // generate the addis instruction except as part of the // load of a large constant, and in that case there is no // way to use r12 as the source. q = obj.Appendp(ctxt, q) q.As = AWORD q.Lineno = p.Lineno q.From.Type = obj.TYPE_CONST q.From.Offset = 0x3c4c0000 q = obj.Appendp(ctxt, q) q.As = AWORD q.Lineno = p.Lineno q.From.Type = obj.TYPE_CONST q.From.Offset = 0x38420000 rel := obj.Addrel(ctxt.Cursym) rel.Off = 0 rel.Siz = 8 rel.Sym = obj.Linklookup(ctxt, ".TOC.", 0) rel.Type = obj.R_ADDRPOWER_PCREL } if cursym.Text.From3.Offset&obj.NOSPLIT == 0 { q = stacksplit(ctxt, q, autosize) // emit split check } if autosize != 0 { /* use MOVDU to adjust R1 when saving R31, if autosize is small */ if cursym.Text.Mark&LEAF == 0 && autosize >= -BIG && autosize <= BIG { mov = AMOVDU aoffset = int(-autosize) } else { q = obj.Appendp(ctxt, q) q.As = AADD q.Lineno = p.Lineno q.From.Type = obj.TYPE_CONST q.From.Offset = int64(-autosize) q.To.Type = obj.TYPE_REG q.To.Reg = REGSP q.Spadj = +autosize } } else if cursym.Text.Mark&LEAF == 0 { // A very few functions that do not return to their caller // (e.g. gogo) are not identified as leaves but still have // no frame. cursym.Text.Mark |= LEAF } if cursym.Text.Mark&LEAF != 0 { cursym.Leaf = true break } q = obj.Appendp(ctxt, q) q.As = AMOVD q.Lineno = p.Lineno q.From.Type = obj.TYPE_REG q.From.Reg = REG_LR q.To.Type = obj.TYPE_REG q.To.Reg = REGTMP q = obj.Appendp(ctxt, q) q.As = mov q.Lineno = p.Lineno q.From.Type = obj.TYPE_REG q.From.Reg = REGTMP q.To.Type = obj.TYPE_MEM q.To.Offset = int64(aoffset) q.To.Reg = REGSP if q.As == AMOVDU { q.Spadj = int32(-aoffset) } if ctxt.Flag_shared { q = obj.Appendp(ctxt, q) q.As = AMOVD q.Lineno = p.Lineno q.From.Type = obj.TYPE_REG q.From.Reg = REG_R2 q.To.Type = obj.TYPE_MEM q.To.Reg = REGSP q.To.Offset = 24 } if cursym.Text.From3.Offset&obj.WRAPPER != 0 { // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame // // MOVD g_panic(g), R3 // CMP R0, R3 // BEQ end // MOVD panic_argp(R3), R4 // ADD $(autosize+8), R1, R5 // CMP R4, R5 // BNE end // ADD $8, R1, R6 // MOVD R6, panic_argp(R3) // end: // NOP // // The NOP is needed to give the jumps somewhere to land. // It is a liblink NOP, not a ppc64 NOP: it encodes to 0 instruction bytes. q = obj.Appendp(ctxt, q) q.As = AMOVD q.From.Type = obj.TYPE_MEM q.From.Reg = REGG q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic q.To.Type = obj.TYPE_REG q.To.Reg = REG_R3 q = obj.Appendp(ctxt, q) q.As = ACMP q.From.Type = obj.TYPE_REG q.From.Reg = REG_R0 q.To.Type = obj.TYPE_REG q.To.Reg = REG_R3 q = obj.Appendp(ctxt, q) q.As = ABEQ q.To.Type = obj.TYPE_BRANCH p1 = q q = obj.Appendp(ctxt, q) q.As = AMOVD q.From.Type = obj.TYPE_MEM q.From.Reg = REG_R3 q.From.Offset = 0 // Panic.argp q.To.Type = obj.TYPE_REG q.To.Reg = REG_R4 q = obj.Appendp(ctxt, q) q.As = AADD q.From.Type = obj.TYPE_CONST q.From.Offset = int64(autosize) + ctxt.FixedFrameSize() q.Reg = REGSP q.To.Type = obj.TYPE_REG q.To.Reg = REG_R5 q = obj.Appendp(ctxt, q) q.As = ACMP q.From.Type = obj.TYPE_REG q.From.Reg = REG_R4 q.To.Type = obj.TYPE_REG q.To.Reg = REG_R5 q = obj.Appendp(ctxt, q) q.As = ABNE q.To.Type = obj.TYPE_BRANCH p2 = q q = obj.Appendp(ctxt, q) q.As = AADD q.From.Type = obj.TYPE_CONST q.From.Offset = ctxt.FixedFrameSize() q.Reg = REGSP q.To.Type = obj.TYPE_REG q.To.Reg = REG_R6 q = obj.Appendp(ctxt, q) q.As = AMOVD q.From.Type = obj.TYPE_REG q.From.Reg = REG_R6 q.To.Type = obj.TYPE_MEM q.To.Reg = REG_R3 q.To.Offset = 0 // Panic.argp q = obj.Appendp(ctxt, q) q.As = obj.ANOP p1.Pcond = q p2.Pcond = q } case obj.ARET: if p.From.Type == obj.TYPE_CONST { ctxt.Diag("using BECOME (%v) is not supported!", p) break } retTarget := p.To.Sym if cursym.Text.Mark&LEAF != 0 { if autosize == 0 { p.As = ABR p.From = obj.Addr{} if retTarget == nil { p.To.Type = obj.TYPE_REG p.To.Reg = REG_LR } else { p.To.Type = obj.TYPE_BRANCH p.To.Sym = retTarget } p.Mark |= BRANCH break } p.As = AADD p.From.Type = obj.TYPE_CONST p.From.Offset = int64(autosize) p.To.Type = obj.TYPE_REG p.To.Reg = REGSP p.Spadj = -autosize q = ctxt.NewProg() q.As = ABR q.Lineno = p.Lineno q.To.Type = obj.TYPE_REG q.To.Reg = REG_LR q.Mark |= BRANCH q.Spadj = +autosize q.Link = p.Link p.Link = q break } p.As = AMOVD p.From.Type = obj.TYPE_MEM p.From.Offset = 0 p.From.Reg = REGSP p.To.Type = obj.TYPE_REG p.To.Reg = REGTMP q = ctxt.NewProg() q.As = AMOVD q.Lineno = p.Lineno q.From.Type = obj.TYPE_REG q.From.Reg = REGTMP q.To.Type = obj.TYPE_REG q.To.Reg = REG_LR q.Link = p.Link p.Link = q p = q if false { // Debug bad returns q = ctxt.NewProg() q.As = AMOVD q.Lineno = p.Lineno q.From.Type = obj.TYPE_MEM q.From.Offset = 0 q.From.Reg = REGTMP q.To.Type = obj.TYPE_REG q.To.Reg = REGTMP q.Link = p.Link p.Link = q p = q } if autosize != 0 { q = ctxt.NewProg() q.As = AADD q.Lineno = p.Lineno q.From.Type = obj.TYPE_CONST q.From.Offset = int64(autosize) q.To.Type = obj.TYPE_REG q.To.Reg = REGSP q.Spadj = -autosize q.Link = p.Link p.Link = q } q1 = ctxt.NewProg() q1.As = ABR q1.Lineno = p.Lineno if retTarget == nil { q1.To.Type = obj.TYPE_REG q1.To.Reg = REG_LR } else { q1.To.Type = obj.TYPE_BRANCH q1.To.Sym = retTarget } q1.Mark |= BRANCH q1.Spadj = +autosize q1.Link = q.Link q.Link = q1 case AADD: if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST { p.Spadj = int32(-p.From.Offset) } } } }
func span0(ctxt *obj.Link, cursym *obj.LSym) { p := cursym.Text if p == nil || p.Link == nil { // handle external functions and ELF section symbols return } ctxt.Cursym = cursym ctxt.Autosize = int32(p.To.Offset + 8) if oprange[AOR&obj.AMask] == nil { buildop(ctxt) } c := int64(0) p.Pc = c var m int var o *Optab for p = p.Link; p != nil; p = p.Link { ctxt.Curp = p p.Pc = c o = oplook(ctxt, p) m = int(o.size) if m == 0 { if p.As != obj.ANOP && p.As != obj.AFUNCDATA && p.As != obj.APCDATA && p.As != obj.AUSEFIELD { ctxt.Diag("zero-width instruction\n%v", p) } continue } c += int64(m) } cursym.Size = c /* * if any procedure is large enough to * generate a large SBRA branch, then * generate extra passes putting branches * around jmps to fix. this is rare. */ bflag := 1 var otxt int64 var q *obj.Prog for bflag != 0 { if ctxt.Debugvlog != 0 { fmt.Fprintf(ctxt.Bso, "%5.2f span1\n", obj.Cputime()) } bflag = 0 c = 0 for p = cursym.Text.Link; p != nil; p = p.Link { p.Pc = c o = oplook(ctxt, p) // very large conditional branches if o.type_ == 6 && p.Pcond != nil { otxt = p.Pcond.Pc - c if otxt < -(1<<17)+10 || otxt >= (1<<17)-10 { q = ctxt.NewProg() q.Link = p.Link p.Link = q q.As = AJMP q.Lineno = p.Lineno q.To.Type = obj.TYPE_BRANCH q.Pcond = p.Pcond p.Pcond = q q = ctxt.NewProg() q.Link = p.Link p.Link = q q.As = AJMP q.Lineno = p.Lineno q.To.Type = obj.TYPE_BRANCH q.Pcond = q.Link.Link addnop(ctxt, p.Link) addnop(ctxt, p) bflag = 1 } } m = int(o.size) if m == 0 { if p.As != obj.ANOP && p.As != obj.AFUNCDATA && p.As != obj.APCDATA && p.As != obj.AUSEFIELD { ctxt.Diag("zero-width instruction\n%v", p) } continue } c += int64(m) } cursym.Size = c } c += -c & (FuncAlign - 1) cursym.Size = c /* * lay out the code, emitting code and data relocations. */ cursym.Grow(cursym.Size) bp := cursym.P var i int32 var out [4]uint32 for p := cursym.Text.Link; p != nil; p = p.Link { ctxt.Pc = p.Pc ctxt.Curp = p o = oplook(ctxt, p) if int(o.size) > 4*len(out) { log.Fatalf("out array in span0 is too small, need at least %d for %v", o.size/4, p) } asmout(ctxt, p, o, out[:]) for i = 0; i < int32(o.size/4); i++ { ctxt.Arch.ByteOrder.PutUint32(bp, out[i]) bp = bp[4:] } } }
func preprocess(ctxt *obj.Link, cursym *obj.LSym) { // TODO(minux): add morestack short-cuts with small fixed frame-size. ctxt.Cursym = cursym // a switch for enabling/disabling instruction scheduling nosched := true if cursym.Text == nil || cursym.Text.Link == nil { return } p := cursym.Text textstksiz := p.To.Offset cursym.Args = p.To.Val.(int32) cursym.Locals = int32(textstksiz) /* * find leaf subroutines * strip NOPs * expand RET * expand BECOME pseudo */ if ctxt.Debugvlog != 0 { fmt.Fprintf(ctxt.Bso, "%5.2f noops\n", obj.Cputime()) } ctxt.Bso.Flush() var q *obj.Prog var q1 *obj.Prog for p := cursym.Text; p != nil; p = p.Link { switch p.As { /* too hard, just leave alone */ case obj.ATEXT: q = p p.Mark |= LABEL | LEAF | SYNC if p.Link != nil { p.Link.Mark |= LABEL } /* too hard, just leave alone */ case AMOVW, AMOVV: q = p if p.To.Type == obj.TYPE_REG && p.To.Reg >= REG_SPECIAL { p.Mark |= LABEL | SYNC break } if p.From.Type == obj.TYPE_REG && p.From.Reg >= REG_SPECIAL { p.Mark |= LABEL | SYNC } /* too hard, just leave alone */ case ASYSCALL, AWORD, ATLBWR, ATLBWI, ATLBP, ATLBR: q = p p.Mark |= LABEL | SYNC case ANOR: q = p if p.To.Type == obj.TYPE_REG { if p.To.Reg == REGZERO { p.Mark |= LABEL | SYNC } } case ABGEZAL, ABLTZAL, AJAL, obj.ADUFFZERO, obj.ADUFFCOPY: cursym.Text.Mark &^= LEAF fallthrough case AJMP, ABEQ, ABGEZ, ABGTZ, ABLEZ, ABLTZ, ABNE, ABFPT, ABFPF: if p.As == ABFPT || p.As == ABFPF { // We don't treat ABFPT and ABFPF as branches here, // so that we will always fill nop (0x0) in their // delay slot during assembly. // This is to workaround a kernel FPU emulator bug // where it uses the user stack to simulate the // instruction in the delay slot if it's not 0x0, // and somehow that leads to SIGSEGV when the kernel // jump to the stack. p.Mark |= SYNC } else { p.Mark |= BRANCH } q = p q1 = p.Pcond if q1 != nil { for q1.As == obj.ANOP { q1 = q1.Link p.Pcond = q1 } if q1.Mark&LEAF == 0 { q1.Mark |= LABEL } } //else { // p.Mark |= LABEL //} q1 = p.Link if q1 != nil { q1.Mark |= LABEL } continue case ARET: q = p if p.Link != nil { p.Link.Mark |= LABEL } continue case obj.ANOP: q1 = p.Link q.Link = q1 /* q is non-nop */ q1.Mark |= p.Mark continue default: q = p continue } } autosize := int32(0) var p1 *obj.Prog var p2 *obj.Prog for p := cursym.Text; p != nil; p = p.Link { o := p.As switch o { case obj.ATEXT: autosize = int32(textstksiz + 8) if (p.Mark&LEAF != 0) && autosize <= 8 { autosize = 0 } else if autosize&4 != 0 { autosize += 4 } p.To.Offset = int64(autosize) - 8 if p.From3.Offset&obj.NOSPLIT == 0 { p = stacksplit(ctxt, p, autosize) // emit split check } q = p if autosize != 0 { q = obj.Appendp(ctxt, p) q.As = AADDV q.Lineno = p.Lineno q.From.Type = obj.TYPE_CONST q.From.Offset = int64(-autosize) q.To.Type = obj.TYPE_REG q.To.Reg = REGSP q.Spadj = +autosize } else if cursym.Text.Mark&LEAF == 0 { if cursym.Text.From3.Offset&obj.NOSPLIT != 0 { if ctxt.Debugvlog != 0 { fmt.Fprintf(ctxt.Bso, "save suppressed in: %s\n", cursym.Name) ctxt.Bso.Flush() } cursym.Text.Mark |= LEAF } } if cursym.Text.Mark&LEAF != 0 { cursym.Leaf = true break } q = obj.Appendp(ctxt, q) q.As = AMOVV q.Lineno = p.Lineno q.From.Type = obj.TYPE_REG q.From.Reg = REGLINK q.To.Type = obj.TYPE_MEM q.To.Offset = int64(0) q.To.Reg = REGSP if cursym.Text.From3.Offset&obj.WRAPPER != 0 { // if(g->panic != nil && g->panic->argp == FP) g->panic->argp = bottom-of-frame // // MOVV g_panic(g), R1 // BEQ R1, end // MOVV panic_argp(R1), R2 // ADDV $(autosize+8), R29, R3 // BNE R2, R3, end // ADDV $8, R29, R2 // MOVV R2, panic_argp(R1) // end: // NOP // // The NOP is needed to give the jumps somewhere to land. // It is a liblink NOP, not an mips NOP: it encodes to 0 instruction bytes. q = obj.Appendp(ctxt, q) q.As = AMOVV q.From.Type = obj.TYPE_MEM q.From.Reg = REGG q.From.Offset = 4 * int64(ctxt.Arch.PtrSize) // G.panic q.To.Type = obj.TYPE_REG q.To.Reg = REG_R1 q = obj.Appendp(ctxt, q) q.As = ABEQ q.From.Type = obj.TYPE_REG q.From.Reg = REG_R1 q.To.Type = obj.TYPE_BRANCH q.Mark |= BRANCH p1 = q q = obj.Appendp(ctxt, q) q.As = AMOVV q.From.Type = obj.TYPE_MEM q.From.Reg = REG_R1 q.From.Offset = 0 // Panic.argp q.To.Type = obj.TYPE_REG q.To.Reg = REG_R2 q = obj.Appendp(ctxt, q) q.As = AADDV q.From.Type = obj.TYPE_CONST q.From.Offset = int64(autosize) + 8 q.Reg = REGSP q.To.Type = obj.TYPE_REG q.To.Reg = REG_R3 q = obj.Appendp(ctxt, q) q.As = ABNE q.From.Type = obj.TYPE_REG q.From.Reg = REG_R2 q.Reg = REG_R3 q.To.Type = obj.TYPE_BRANCH q.Mark |= BRANCH p2 = q q = obj.Appendp(ctxt, q) q.As = AADDV q.From.Type = obj.TYPE_CONST q.From.Offset = 8 q.Reg = REGSP q.To.Type = obj.TYPE_REG q.To.Reg = REG_R2 q = obj.Appendp(ctxt, q) q.As = AMOVV q.From.Type = obj.TYPE_REG q.From.Reg = REG_R2 q.To.Type = obj.TYPE_MEM q.To.Reg = REG_R1 q.To.Offset = 0 // Panic.argp q = obj.Appendp(ctxt, q) q.As = obj.ANOP p1.Pcond = q p2.Pcond = q } case ARET: if p.From.Type == obj.TYPE_CONST { ctxt.Diag("using BECOME (%v) is not supported!", p) break } if p.To.Sym != nil { // retjmp p.As = AJMP p.To.Type = obj.TYPE_BRANCH break } if cursym.Text.Mark&LEAF != 0 { if autosize == 0 { p.As = AJMP p.From = obj.Addr{} p.To.Type = obj.TYPE_MEM p.To.Offset = 0 p.To.Reg = REGLINK p.Mark |= BRANCH break } p.As = AADDV p.From.Type = obj.TYPE_CONST p.From.Offset = int64(autosize) p.To.Type = obj.TYPE_REG p.To.Reg = REGSP p.Spadj = -autosize q = ctxt.NewProg() q.As = AJMP q.Lineno = p.Lineno q.To.Type = obj.TYPE_MEM q.To.Offset = 0 q.To.Reg = REGLINK q.Mark |= BRANCH q.Spadj = +autosize q.Link = p.Link p.Link = q break } p.As = AMOVV p.From.Type = obj.TYPE_MEM p.From.Offset = 0 p.From.Reg = REGSP p.To.Type = obj.TYPE_REG p.To.Reg = REG_R4 if false { // Debug bad returns q = ctxt.NewProg() q.As = AMOVV q.Lineno = p.Lineno q.From.Type = obj.TYPE_MEM q.From.Offset = 0 q.From.Reg = REG_R4 q.To.Type = obj.TYPE_REG q.To.Reg = REGTMP q.Link = p.Link p.Link = q p = q } if autosize != 0 { q = ctxt.NewProg() q.As = AADDV q.Lineno = p.Lineno q.From.Type = obj.TYPE_CONST q.From.Offset = int64(autosize) q.To.Type = obj.TYPE_REG q.To.Reg = REGSP q.Spadj = -autosize q.Link = p.Link p.Link = q } q1 = ctxt.NewProg() q1.As = AJMP q1.Lineno = p.Lineno q1.To.Type = obj.TYPE_MEM q1.To.Offset = 0 q1.To.Reg = REG_R4 q1.Mark |= BRANCH q1.Spadj = +autosize q1.Link = q.Link q.Link = q1 case AADDV, AADDVU: if p.To.Type == obj.TYPE_REG && p.To.Reg == REGSP && p.From.Type == obj.TYPE_CONST { p.Spadj = int32(-p.From.Offset) } } } if nosched { // if we don't do instruction scheduling, simply add // NOP after each branch instruction. for p = cursym.Text; p != nil; p = p.Link { if p.Mark&BRANCH != 0 { addnop(ctxt, p) } } return } // instruction scheduling q = nil // p - 1 q1 = cursym.Text // top of block o := 0 // count of instructions for p = cursym.Text; p != nil; p = p1 { p1 = p.Link o++ if p.Mark&NOSCHED != 0 { if q1 != p { sched(ctxt, q1, q) } for ; p != nil; p = p.Link { if p.Mark&NOSCHED == 0 { break } q = p } p1 = p q1 = p o = 0 continue } if p.Mark&(LABEL|SYNC) != 0 { if q1 != p { sched(ctxt, q1, q) } q1 = p o = 1 } if p.Mark&(BRANCH|SYNC) != 0 { sched(ctxt, q1, p) q1 = p1 o = 0 } if o >= NSCHED { sched(ctxt, q1, p) q1 = p1 o = 0 } q = p } }