| // Inferno utils/6l/obj.c |
| // https://bitbucket.org/inferno-os/inferno-os/src/master/utils/6l/obj.c |
| // |
| // Copyright © 1994-1999 Lucent Technologies Inc. All rights reserved. |
| // Portions Copyright © 1995-1997 C H Forsyth (forsyth@terzarima.net) |
| // Portions Copyright © 1997-1999 Vita Nuova Limited |
| // Portions Copyright © 2000-2007 Vita Nuova Holdings Limited (www.vitanuova.com) |
| // Portions Copyright © 2004,2006 Bruce Ellis |
| // Portions Copyright © 2005-2007 C H Forsyth (forsyth@terzarima.net) |
| // Revisions Copyright © 2000-2007 Lucent Technologies Inc. and others |
| // Portions Copyright © 2009 The Go Authors. All rights reserved. |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| package ld |
| |
| import ( |
| "bufio" |
| "cmd/internal/goobj" |
| "cmd/internal/objabi" |
| "cmd/internal/sys" |
| "cmd/link/internal/benchmark" |
| "flag" |
| "log" |
| "os" |
| "runtime" |
| "runtime/pprof" |
| "strings" |
| ) |
| |
| var ( |
| pkglistfornote []byte |
| windowsgui bool // writes a "GUI binary" instead of a "console binary" |
| ownTmpDir bool // set to true if tmp dir created by linker (e.g. no -tmpdir) |
| ) |
| |
| func init() { |
| flag.Var(&rpath, "r", "set the ELF dynamic linker search `path` to dir1:dir2:...") |
| } |
| |
| // Flags used by the linker. The exported flags are used by the architecture-specific packages. |
| var ( |
| flagBuildid = flag.String("buildid", "", "record `id` as Go toolchain build id") |
| |
| flagOutfile = flag.String("o", "", "write output to `file`") |
| flagPluginPath = flag.String("pluginpath", "", "full path name for plugin") |
| |
| flagInstallSuffix = flag.String("installsuffix", "", "set package directory `suffix`") |
| flagDumpDep = flag.Bool("dumpdep", false, "dump symbol dependency graph") |
| flagRace = flag.Bool("race", false, "enable race detector") |
| flagMsan = flag.Bool("msan", false, "enable MSan interface") |
| flagAslr = flag.Bool("aslr", true, "enable ASLR for buildmode=c-shared on windows") |
| |
| flagFieldTrack = flag.String("k", "", "set field tracking `symbol`") |
| flagLibGCC = flag.String("libgcc", "", "compiler support lib for internal linking; use \"none\" to disable") |
| flagTmpdir = flag.String("tmpdir", "", "use `directory` for temporary files") |
| |
| flagExtld = flag.String("extld", "", "use `linker` when linking in external mode") |
| flagExtldflags = flag.String("extldflags", "", "pass `flags` to external linker") |
| flagExtar = flag.String("extar", "", "archive program for buildmode=c-archive") |
| |
| flagA = flag.Bool("a", false, "no-op (deprecated)") |
| FlagC = flag.Bool("c", false, "dump call graph") |
| FlagD = flag.Bool("d", false, "disable dynamic executable") |
| flagF = flag.Bool("f", false, "ignore version mismatch") |
| flagG = flag.Bool("g", false, "disable go package data checks") |
| flagH = flag.Bool("h", false, "halt on error") |
| flagN = flag.Bool("n", false, "dump symbol table") |
| FlagS = flag.Bool("s", false, "disable symbol table") |
| FlagW = flag.Bool("w", false, "disable DWARF generation") |
| flag8 bool // use 64-bit addresses in symbol table |
| flagInterpreter = flag.String("I", "", "use `linker` as ELF dynamic linker") |
| FlagDebugTramp = flag.Int("debugtramp", 0, "debug trampolines") |
| FlagDebugTextSize = flag.Int("debugppc64textsize", 0, "debug PPC64 text section max") |
| FlagStrictDups = flag.Int("strictdups", 0, "sanity check duplicate symbol contents during object file reading (1=warn 2=err).") |
| FlagRound = flag.Int("R", -1, "set address rounding `quantum`") |
| FlagTextAddr = flag.Int64("T", -1, "set text segment `address`") |
| flagEntrySymbol = flag.String("E", "", "set `entry` symbol name") |
| cpuprofile = flag.String("cpuprofile", "", "write cpu profile to `file`") |
| memprofile = flag.String("memprofile", "", "write memory profile to `file`") |
| memprofilerate = flag.Int64("memprofilerate", 0, "set runtime.MemProfileRate to `rate`") |
| benchmarkFlag = flag.String("benchmark", "", "set to 'mem' or 'cpu' to enable phase benchmarking") |
| benchmarkFileFlag = flag.String("benchmarkprofile", "", "emit phase profiles to `base`_phase.{cpu,mem}prof") |
| ) |
| |
| // Main is the main entry point for the linker code. |
| func Main(arch *sys.Arch, theArch Arch) { |
| thearch = theArch |
| ctxt := linknew(arch) |
| 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) |
| } |
| } |
| |
| final := gorootFinal() |
| addstrdata1(ctxt, "runtime.defaultGOROOT="+final) |
| addstrdata1(ctxt, "cmd/internal/objabi.defaultGOROOT="+final) |
| |
| // TODO(matloob): define these above and then check flag values here |
| if ctxt.Arch.Family == sys.AMD64 && objabi.GOOS == "plan9" { |
| flag.BoolVar(&flag8, "8", false, "use 64-bit addresses in symbol table") |
| } |
| flagHeadType := flag.String("H", "", "set header `type`") |
| flag.BoolVar(&ctxt.linkShared, "linkshared", false, "link against installed Go shared libraries") |
| flag.Var(&ctxt.LinkMode, "linkmode", "set link `mode`") |
| flag.Var(&ctxt.BuildMode, "buildmode", "set build `mode`") |
| flag.BoolVar(&ctxt.compressDWARF, "compressdwarf", true, "compress DWARF if possible") |
| objabi.Flagfn1("B", "add an ELF NT_GNU_BUILD_ID `note` when using ELF", addbuildinfo) |
| objabi.Flagfn1("L", "add specified `directory` to library path", func(a string) { Lflag(ctxt, a) }) |
| objabi.AddVersionFlag() // -V |
| objabi.Flagfn1("X", "add string value `definition` of the form importpath.name=value", func(s string) { addstrdata1(ctxt, s) }) |
| objabi.Flagcount("v", "print link trace", &ctxt.Debugvlog) |
| objabi.Flagfn1("importcfg", "read import configuration from `file`", ctxt.readImportCfg) |
| |
| objabi.Flagparse(usage) |
| |
| if ctxt.Debugvlog > 0 { |
| // dump symbol info on crash |
| defer func() { ctxt.loader.Dump() }() |
| } |
| |
| switch *flagHeadType { |
| case "": |
| case "windowsgui": |
| ctxt.HeadType = objabi.Hwindows |
| windowsgui = true |
| default: |
| if err := ctxt.HeadType.Set(*flagHeadType); err != nil { |
| Errorf(nil, "%v", err) |
| usage() |
| } |
| } |
| if ctxt.HeadType == objabi.Hunknown { |
| ctxt.HeadType.Set(objabi.GOOS) |
| } |
| |
| if !*flagAslr && ctxt.BuildMode != BuildModeCShared { |
| Errorf(nil, "-aslr=false is only allowed for -buildmode=c-shared") |
| usage() |
| } |
| |
| checkStrictDups = *FlagStrictDups |
| |
| startProfile() |
| if ctxt.BuildMode == BuildModeUnset { |
| ctxt.BuildMode.Set("exe") |
| } |
| |
| if ctxt.BuildMode != BuildModeShared && flag.NArg() != 1 { |
| usage() |
| } |
| |
| if *flagOutfile == "" { |
| *flagOutfile = "a.out" |
| if ctxt.HeadType == objabi.Hwindows { |
| *flagOutfile += ".exe" |
| } |
| } |
| |
| interpreter = *flagInterpreter |
| |
| if *flagBuildid == "" && ctxt.Target.IsOpenbsd() { |
| // TODO(jsing): Remove once direct syscalls are no longer in use. |
| // OpenBSD 6.7 onwards will not permit direct syscalls from a |
| // dynamically linked binary unless it identifies the binary |
| // contains a .note.go.buildid ELF note. See issue #36435. |
| *flagBuildid = "go-openbsd" |
| } |
| |
| // enable benchmarking |
| var bench *benchmark.Metrics |
| if len(*benchmarkFlag) != 0 { |
| if *benchmarkFlag == "mem" { |
| bench = benchmark.New(benchmark.GC, *benchmarkFileFlag) |
| } else if *benchmarkFlag == "cpu" { |
| bench = benchmark.New(benchmark.NoGC, *benchmarkFileFlag) |
| } else { |
| Errorf(nil, "unknown benchmark flag: %q", *benchmarkFlag) |
| usage() |
| } |
| } |
| |
| bench.Start("libinit") |
| libinit(ctxt) // creates outfile |
| bench.Start("computeTLSOffset") |
| ctxt.computeTLSOffset() |
| bench.Start("Archinit") |
| thearch.Archinit(ctxt) |
| |
| if ctxt.linkShared && !ctxt.IsELF { |
| Exitf("-linkshared can only be used on elf systems") |
| } |
| |
| if ctxt.Debugvlog != 0 { |
| ctxt.Logf("HEADER = -H%d -T0x%x -R0x%x\n", ctxt.HeadType, uint64(*FlagTextAddr), uint32(*FlagRound)) |
| } |
| |
| zerofp := goobj.FingerprintType{} |
| switch ctxt.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, "", zerofp) |
| } |
| case BuildModePlugin: |
| addlibpath(ctxt, "command line", "command line", flag.Arg(0), *flagPluginPath, "", zerofp) |
| default: |
| addlibpath(ctxt, "command line", "command line", flag.Arg(0), "main", "", zerofp) |
| } |
| bench.Start("loadlib") |
| ctxt.loadlib() |
| |
| bench.Start("deadcode") |
| deadcode(ctxt) |
| |
| bench.Start("linksetup") |
| ctxt.linksetup() |
| |
| bench.Start("dostrdata") |
| ctxt.dostrdata() |
| if objabi.Experiment.FieldTrack { |
| bench.Start("fieldtrack") |
| fieldtrack(ctxt.Arch, ctxt.loader) |
| } |
| |
| bench.Start("dwarfGenerateDebugInfo") |
| dwarfGenerateDebugInfo(ctxt) |
| |
| bench.Start("callgraph") |
| ctxt.callgraph() |
| |
| bench.Start("dostkcheck") |
| ctxt.dostkcheck() |
| |
| bench.Start("mangleTypeSym") |
| ctxt.mangleTypeSym() |
| |
| if ctxt.IsELF { |
| bench.Start("doelf") |
| ctxt.doelf() |
| } |
| if ctxt.IsDarwin() { |
| bench.Start("domacho") |
| ctxt.domacho() |
| } |
| if ctxt.IsWindows() { |
| bench.Start("dope") |
| ctxt.dope() |
| bench.Start("windynrelocsyms") |
| ctxt.windynrelocsyms() |
| } |
| if ctxt.IsAIX() { |
| bench.Start("doxcoff") |
| ctxt.doxcoff() |
| } |
| |
| bench.Start("textbuildid") |
| ctxt.textbuildid() |
| bench.Start("addexport") |
| setupdynexp(ctxt) |
| ctxt.setArchSyms() |
| ctxt.addexport() |
| bench.Start("Gentext") |
| thearch.Gentext(ctxt, ctxt.loader) // trampolines, call stubs, etc. |
| |
| bench.Start("textaddress") |
| ctxt.textaddress() |
| bench.Start("typelink") |
| ctxt.typelink() |
| bench.Start("buildinfo") |
| ctxt.buildinfo() |
| bench.Start("pclntab") |
| containers := ctxt.findContainerSyms() |
| pclnState := ctxt.pclntab(containers) |
| bench.Start("findfunctab") |
| ctxt.findfunctab(pclnState, containers) |
| bench.Start("dwarfGenerateDebugSyms") |
| dwarfGenerateDebugSyms(ctxt) |
| bench.Start("symtab") |
| symGroupType := ctxt.symtab(pclnState) |
| bench.Start("dodata") |
| ctxt.dodata(symGroupType) |
| bench.Start("address") |
| order := ctxt.address() |
| bench.Start("dwarfcompress") |
| dwarfcompress(ctxt) |
| bench.Start("layout") |
| filesize := ctxt.layout(order) |
| |
| // Write out the output file. |
| // It is split into two parts (Asmb and Asmb2). The first |
| // part writes most of the content (sections and segments), |
| // for which we have computed the size and offset, in a |
| // mmap'd region. The second part writes more content, for |
| // which we don't know the size. |
| if ctxt.Arch.Family != sys.Wasm { |
| // Don't mmap if we're building for Wasm. Wasm file |
| // layout is very different so filesize is meaningless. |
| if err := ctxt.Out.Mmap(filesize); err != nil { |
| panic(err) |
| } |
| } |
| // asmb will redirect symbols to the output file mmap, and relocations |
| // will be applied directly there. |
| bench.Start("Asmb") |
| asmb(ctxt) |
| |
| exitIfErrors() |
| |
| // Generate additional symbols for the native symbol table just prior |
| // to code generation. |
| bench.Start("GenSymsLate") |
| if thearch.GenSymsLate != nil { |
| thearch.GenSymsLate(ctxt, ctxt.loader) |
| } |
| |
| bench.Start("Asmb2") |
| asmb2(ctxt) |
| |
| bench.Start("Munmap") |
| ctxt.Out.Close() // Close handles Munmapping if necessary. |
| |
| bench.Start("hostlink") |
| ctxt.hostlink() |
| if ctxt.Debugvlog != 0 { |
| ctxt.Logf("%s", ctxt.loader.Stat()) |
| ctxt.Logf("%d liveness data\n", liveness) |
| } |
| bench.Start("Flush") |
| ctxt.Bso.Flush() |
| bench.Start("archive") |
| ctxt.archive() |
| bench.Report(os.Stdout) |
| |
| errorexit() |
| } |
| |
| type Rpath struct { |
| set bool |
| val string |
| } |
| |
| func (r *Rpath) Set(val string) error { |
| r.set = true |
| r.val = val |
| return nil |
| } |
| |
| func (r *Rpath) String() string { |
| return r.val |
| } |
| |
| func startProfile() { |
| if *cpuprofile != "" { |
| f, err := os.Create(*cpuprofile) |
| if err != nil { |
| log.Fatalf("%v", err) |
| } |
| if err := pprof.StartCPUProfile(f); err != nil { |
| log.Fatalf("%v", err) |
| } |
| AtExit(pprof.StopCPUProfile) |
| } |
| if *memprofile != "" { |
| if *memprofilerate != 0 { |
| runtime.MemProfileRate = int(*memprofilerate) |
| } |
| f, err := os.Create(*memprofile) |
| if err != nil { |
| log.Fatalf("%v", err) |
| } |
| AtExit(func() { |
| // Profile all outstanding allocations. |
| runtime.GC() |
| // compilebench parses the memory profile to extract memstats, |
| // which are only written in the legacy pprof format. |
| // See golang.org/issue/18641 and runtime/pprof/pprof.go:writeHeap. |
| const writeLegacyFormat = 1 |
| if err := pprof.Lookup("heap").WriteTo(f, writeLegacyFormat); err != nil { |
| log.Fatalf("%v", err) |
| } |
| }) |
| } |
| } |
