import (
"bytes"
- "cmd/internal/bio"
- "cmd/internal/goobj"
- "cmd/internal/obj"
- "cmd/internal/objabi"
- "cmd/internal/sys"
- "cmd/link/internal/loadelf"
- "cmd/link/internal/loader"
- "cmd/link/internal/loadmacho"
- "cmd/link/internal/loadpe"
- "cmd/link/internal/loadxcoff"
- "cmd/link/internal/sym"
- "crypto/sha1"
"debug/elf"
"debug/macho"
"encoding/base64"
"encoding/binary"
"fmt"
"internal/buildcfg"
- exec "internal/execabs"
"io"
- "io/ioutil"
"log"
"os"
+ "os/exec"
"path/filepath"
"runtime"
+ "sort"
"strings"
"sync"
+
+ "cmd/internal/bio"
+ "cmd/internal/goobj"
+ "cmd/internal/notsha256"
+ "cmd/internal/objabi"
+ "cmd/internal/sys"
+ "cmd/link/internal/loadelf"
+ "cmd/link/internal/loader"
+ "cmd/link/internal/loadmacho"
+ "cmd/link/internal/loadpe"
+ "cmd/link/internal/loadxcoff"
+ "cmd/link/internal/sym"
)
// Data layout and relocation.
DynStr loader.Sym
unreachableMethod loader.Sym
+
+ // Symbol containing a list of all the inittasks that need
+ // to be run at startup.
+ mainInittasks loader.Sym
}
// mkArchSym is a helper for setArchSyms, to set up a special symbol.
ctxt.loader.SetAttrReachable(*ls, true)
}
-// mkArchVecSym is similar to setArchSyms, but operates on elements within
+// mkArchSymVec is similar to setArchSyms, but operates on elements within
// a slice, where each element corresponds to some symbol version.
func (ctxt *Link) mkArchSymVec(name string, ver int, ls []loader.Sym) {
ls[ver] = ctxt.loader.LookupOrCreateSym(name, ver)
// We leave some room for extra stuff like PLT stubs.
TrampLimit uint64
- Androiddynld string
- Linuxdynld string
- Freebsddynld string
- Netbsddynld string
- Openbsddynld string
- Dragonflydynld string
- Solarisdynld string
-
// Empty spaces between codeblocks will be padded with this value.
// For example an architecture might want to pad with a trap instruction to
// catch wayward programs. Architectures that do not define a padding value
// is the contents of the to-be-relocated data item (from sym.P). Return
// value is the appropriately relocated value (to be written back to the
// same spot in sym.P), number of external _host_ relocations needed (i.e.
- // ELF/Mach-O/etc. relocations, not Go relocations, this must match Elfreloc1,
+ // ELF/Mach-O/etc. relocations, not Go relocations, this must match ELF.Reloc1,
// etc.), and a boolean indicating success/failure (a failing value indicates
// a fatal error).
Archreloc func(*Target, *loader.Loader, *ArchSyms, loader.Reloc, loader.Sym,
// needed.
Extreloc func(*Target, *loader.Loader, loader.Reloc, loader.Sym) (loader.ExtReloc, bool)
- Elfreloc1 func(*Link, *OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int, int64) bool
- ElfrelocSize uint32 // size of an ELF relocation record, must match Elfreloc1.
- Elfsetupplt func(ctxt *Link, plt, gotplt *loader.SymbolBuilder, dynamic loader.Sym)
Gentext func(*Link, *loader.Loader) // Generate text before addressing has been performed.
Machoreloc1 func(*sys.Arch, *OutBuf, *loader.Loader, loader.Sym, loader.ExtReloc, int64) bool
MachorelocSize uint32 // size of an Mach-O relocation record, must match Machoreloc1.
// optional override for assignAddress
AssignAddress func(ldr *loader.Loader, sect *sym.Section, n int, s loader.Sym, va uint64, isTramp bool) (*sym.Section, int, uint64)
+
+ // ELF specific information.
+ ELF ELFArch
}
var (
Segrelrodata sym.Segment
Segdata sym.Segment
Segdwarf sym.Segment
+ Segpdata sym.Segment // windows-only
+ Segxdata sym.Segment // windows-only
- Segments = []*sym.Segment{&Segtext, &Segrodata, &Segrelrodata, &Segdata, &Segdwarf}
+ Segments = []*sym.Segment{&Segtext, &Segrodata, &Segrelrodata, &Segdata, &Segdwarf, &Segpdata, &Segxdata}
)
const pkgdef = "__.PKGDEF"
// to support internal linking mode.
externalobj = false
+ // dynimportfail is a list of packages for which generating
+ // the dynimport file, _cgo_import.go, failed. If there are
+ // any of these objects, we must link externally. Issue 52863.
+ dynimportfail []string
+
+ // preferlinkext is a list of packages for which the Go command
+ // noticed use of peculiar C flags. If we see any of these,
+ // default to linking externally unless overridden by the
+ // user. See issues #58619, #58620, and #58848.
+ preferlinkext []string
+
// unknownObjFormat is set to true if we see an object whose
// format we don't recognize.
unknownObjFormat = false
}
}
+ if name == "runtime" {
+ Exitf("error: unable to find runtime.a")
+ }
ctxt.Logf("warning: unable to find %s.a\n", name)
return nil
}
// extld returns the current external linker.
func (ctxt *Link) extld() []string {
if len(flagExtld) == 0 {
- flagExtld = []string{"gcc"}
+ // Return the default external linker for the platform.
+ // This only matters when link tool is called directly without explicit -extld,
+ // go tool already passes the correct linker in other cases.
+ switch buildcfg.GOOS {
+ case "darwin", "freebsd", "openbsd":
+ flagExtld = []string{"clang"}
+ default:
+ flagExtld = []string{"gcc"}
+ }
}
return flagExtld
}
default:
log.Fatalf("invalid -strictdups flag value %d", *FlagStrictDups)
}
- elfsetstring1 := func(str string, off int) { elfsetstring(ctxt, 0, str, off) }
- ctxt.loader = loader.NewLoader(flags, elfsetstring1, &ctxt.ErrorReporter.ErrorReporter)
+ ctxt.loader = loader.NewLoader(flags, &ctxt.ErrorReporter.ErrorReporter)
ctxt.ErrorReporter.SymName = func(s loader.Sym) string {
return ctxt.loader.SymName(s)
}
// If we have any undefined symbols in external
// objects, try to read them from the libgcc file.
any := false
- undefs := ctxt.loader.UndefinedRelocTargets(1)
+ undefs, froms := ctxt.loader.UndefinedRelocTargets(1)
if len(undefs) > 0 {
any = true
+ if ctxt.Debugvlog > 1 {
+ ctxt.Logf("loadlib: first unresolved is %s [%d] from %s [%d]\n",
+ ctxt.loader.SymName(undefs[0]), undefs[0],
+ ctxt.loader.SymName(froms[0]), froms[0])
+ }
}
if any {
if *flagLibGCC == "" {
if *flagLibGCC != "none" {
hostArchive(ctxt, *flagLibGCC)
}
+ // For glibc systems, the linker setup used by GCC
+ // looks like
+ //
+ // GROUP ( /lib/x86_64-linux-gnu/libc.so.6
+ // /usr/lib/x86_64-linux-gnu/libc_nonshared.a
+ // AS_NEEDED ( /lib64/ld-linux-x86-64.so.2 ) )
+ //
+ // where libc_nonshared.a contains a small set of
+ // symbols including "__stack_chk_fail_local" and a
+ // few others. Thus if we are doing internal linking
+ // and "__stack_chk_fail_local" is unresolved (most
+ // likely due to the use of -fstack-protector), try
+ // loading libc_nonshared.a to resolve it.
+ //
+ // On Alpine Linux (musl-based), the library providing
+ // this symbol is called libssp_nonshared.a.
+ isunresolved := symbolsAreUnresolved(ctxt, []string{"__stack_chk_fail_local"})
+ if isunresolved[0] {
+ if p := ctxt.findLibPath("libc_nonshared.a"); p != "none" {
+ hostArchive(ctxt, p)
+ }
+ if p := ctxt.findLibPath("libssp_nonshared.a"); p != "none" {
+ hostArchive(ctxt, p)
+ }
+ }
}
}
// We've loaded all the code now.
ctxt.Loaded = true
- importcycles()
-
strictDupMsgCount = ctxt.loader.NStrictDupMsgs()
}
hostObject(ctxt, "crt2", p)
}
}
+ if *flagRace {
+ if p := ctxt.findLibPath("libsynchronization.a"); p != "none" {
+ hostArchive(ctxt, p)
+ }
+ }
if p := ctxt.findLibPath("libmingwex.a"); p != "none" {
hostArchive(ctxt, p)
}
hostArchive(ctxt, p)
}
any = false
- undefs := ctxt.loader.UndefinedRelocTargets(1)
+ undefs, froms := ctxt.loader.UndefinedRelocTargets(1)
if len(undefs) > 0 {
any = true
+ if ctxt.Debugvlog > 1 {
+ ctxt.Logf("loadWindowsHostArchives: remaining unresolved is %s [%d] from %s [%d]\n",
+ ctxt.loader.SymName(undefs[0]), undefs[0],
+ ctxt.loader.SymName(froms[0]), froms[0])
+ }
}
}
// If needed, create the __CTOR_LIST__ and __DTOR_LIST__
ctxt.loader.SetAttrSpecial(sb.Sym(), true)
}
}
+
+ // Fix up references to DLL import symbols now that we're done
+ // pulling in new objects.
+ if err := loadpe.PostProcessImports(); err != nil {
+ Errorf(nil, "%v", err)
+ }
+
// TODO: maybe do something similar to peimporteddlls to collect
// all lib names and try link them all to final exe just like
// libmingwex.a and libmingw32.a:
// typeSymbolMangle mangles the given symbol name into something shorter.
//
-// Keep the type.. prefix, which parts of the linker (like the
+// Keep the type:. prefix, which parts of the linker (like the
// DWARF generator) know means the symbol is not decodable.
-// Leave type.runtime. symbols alone, because other parts of
+// Leave type:runtime. symbols alone, because other parts of
// the linker manipulates them.
func typeSymbolMangle(name string) string {
- if !strings.HasPrefix(name, "type.") {
+ isType := strings.HasPrefix(name, "type:")
+ if !isType && !strings.Contains(name, "@") {
+ // Issue 58800: instantiated symbols may include a type name, which may contain "@"
+ return name
+ }
+ if strings.HasPrefix(name, "type:runtime.") {
return name
}
- if strings.HasPrefix(name, "type.runtime.") {
+ if strings.HasPrefix(name, "go:string.") {
+ // String symbols will be grouped to a single go:string.* symbol.
+ // No need to mangle individual symbol names.
return name
}
if len(name) <= 14 && !strings.Contains(name, "@") { // Issue 19529
return name
}
- hash := sha1.Sum([]byte(name))
- prefix := "type."
- if name[5] == '.' {
- prefix = "type.."
+ if isType {
+ hash := notsha256.Sum256([]byte(name[5:]))
+ prefix := "type:"
+ if name[5] == '.' {
+ prefix = "type:."
+ }
+ return prefix + base64.StdEncoding.EncodeToString(hash[:6])
+ }
+ // instantiated symbol, replace type name in []
+ i := strings.IndexByte(name, '[')
+ j := strings.LastIndexByte(name, ']')
+ if j == -1 || j <= i {
+ j = len(name)
}
- return prefix + base64.StdEncoding.EncodeToString(hash[:6])
+ hash := notsha256.Sum256([]byte(name[i+1 : j]))
+ return name[:i+1] + base64.StdEncoding.EncodeToString(hash[:6]) + name[j:]
}
/*
continue
}
+ if arhdr.name == "dynimportfail" {
+ dynimportfail = append(dynimportfail, lib.Pkg)
+ }
+ if arhdr.name == "preferlinkext" {
+ // Ignore this directive if -linkmode has been
+ // set explicitly.
+ if ctxt.LinkMode == LinkAuto {
+ preferlinkext = append(preferlinkext, lib.Pkg)
+ }
+ }
+
// Skip other special (non-object-file) sections that
// build tools may have added. Such sections must have
// short names so that the suffix is not truncated.
// These packages can use internal linking mode.
// Others trigger external mode.
var internalpkg = []string{
+ "crypto/internal/boring",
+ "crypto/internal/boring/syso",
"crypto/x509",
"net",
"os/user",
"runtime/cgo",
"runtime/race",
+ "runtime/race/internal/amd64v1",
+ "runtime/race/internal/amd64v3",
"runtime/msan",
"runtime/asan",
}
if err != nil {
Exitf("cannot reopen %s: %v", h.pn, err)
}
-
f.MustSeek(h.off, 0)
if h.ld == nil {
Errorf(nil, "%s: unrecognized object file format", h.pn)
continue
}
h.ld(ctxt, f, h.pkg, h.length, h.pn)
+ if *flagCaptureHostObjs != "" {
+ captureHostObj(h)
+ }
f.Close()
}
}
// create temporary directory and arrange cleanup
if *flagTmpdir == "" {
- dir, err := ioutil.TempDir("", "go-link-")
+ dir, err := os.MkdirTemp("", "go-link-")
if err != nil {
log.Fatal(err)
}
// hostobjCopy creates a copy of the object files in hostobj in a
// temporary directory.
-func hostobjCopy() (paths []string) {
+func (ctxt *Link) hostobjCopy() (paths []string) {
var wg sync.WaitGroup
sema := make(chan struct{}, runtime.NumCPU()) // limit open file descriptors
for i, h := range hostobj {
h := h
dst := filepath.Join(*flagTmpdir, fmt.Sprintf("%06d.o", i))
paths = append(paths, dst)
+ if ctxt.Debugvlog != 0 {
+ ctxt.Logf("host obj copy: %s from pkg %s -> %s\n", h.pn, h.pkg, dst)
+ }
wg.Add(1)
go func() {
}
INSERT AFTER .debug_types;
`
- err := ioutil.WriteFile(path, []byte(src), 0666)
+ err := os.WriteFile(path, []byte(src), 0666)
if err != nil {
Errorf(nil, "WriteFile %s failed: %v", name, err)
}
}
argv = append(argv, *flagOutfile)
argv = append(argv, filepath.Join(*flagTmpdir, "go.o"))
- argv = append(argv, hostobjCopy()...)
+ argv = append(argv, ctxt.hostobjCopy()...)
if ctxt.Debugvlog != 0 {
ctxt.Logf("archive: %s\n", strings.Join(argv, " "))
if ctxt.HeadType == objabi.Hdarwin {
// Recent versions of macOS print
// ld: warning: option -s is obsolete and being ignored
- // so do not pass any arguments.
+ // so do not pass any arguments (but we strip symbols below).
} else {
argv = append(argv, "-s")
}
// On darwin, whether to combine DWARF into executable.
// Only macOS supports unmapped segments such as our __DWARF segment.
- combineDwarf := ctxt.IsDarwin() && !*FlagS && !*FlagW && !debug_s && machoPlatform == PLATFORM_MACOS
+ combineDwarf := ctxt.IsDarwin() && !*FlagW && machoPlatform == PLATFORM_MACOS
switch ctxt.HeadType {
case objabi.Hdarwin:
}
if !combineDwarf {
argv = append(argv, "-Wl,-S") // suppress STAB (symbolic debugging) symbols
+ if debug_s {
+ // We are generating a binary with symbol table suppressed.
+ // Suppress local symbols. We need to keep dynamically exported
+ // and referenced symbols so the dynamic linker can resolve them.
+ argv = append(argv, "-Wl,-x")
+ }
}
case objabi.Hopenbsd:
argv = append(argv, "-Wl,-nopie")
argv = append(argv, "-pthread")
+ if ctxt.Arch.InFamily(sys.ARM64) {
+ // Disable execute-only on openbsd/arm64 - the Go arm64 assembler
+ // currently stores constants in the text section rather than in rodata.
+ // See issue #59615.
+ argv = append(argv, "-Wl,--no-execute-only")
+ }
case objabi.Hwindows:
if windowsgui {
argv = append(argv, "-mwindows")
argv = append(argv, "-Wl,-bbigtoc")
}
- // Enable ASLR on Windows.
- addASLRargs := func(argv []string) []string {
- // Enable ASLR.
- argv = append(argv, "-Wl,--dynamicbase")
+ // On PPC64, verify the external toolchain supports Power10. This is needed when
+ // PC relative relocations might be generated by Go. Only targets compiling ELF
+ // binaries might generate these relocations.
+ if ctxt.IsPPC64() && ctxt.IsElf() && buildcfg.GOPPC64 >= 10 {
+ if !linkerFlagSupported(ctxt.Arch, argv[0], "", "-mcpu=power10") {
+ Exitf("The external toolchain does not support -mcpu=power10. " +
+ " This is required to externally link GOPPC64 >= power10")
+ }
+ }
+
+ // Enable/disable ASLR on Windows.
+ addASLRargs := func(argv []string, val bool) []string {
+ // Old/ancient versions of GCC support "--dynamicbase" and
+ // "--high-entropy-va" but don't enable it by default. In
+ // addition, they don't accept "--disable-dynamicbase" or
+ // "--no-dynamicbase", so the only way to disable ASLR is to
+ // not pass any flags at all.
+ //
+ // More modern versions of GCC (and also clang) enable ASLR
+ // by default. With these compilers, however you can turn it
+ // off if you want using "--disable-dynamicbase" or
+ // "--no-dynamicbase".
+ //
+ // The strategy below is to try using "--disable-dynamicbase";
+ // if this succeeds, then assume we're working with more
+ // modern compilers and act accordingly. If it fails, assume
+ // an ancient compiler with ancient defaults.
+ var dbopt string
+ var heopt string
+ dbon := "--dynamicbase"
+ heon := "--high-entropy-va"
+ dboff := "--disable-dynamicbase"
+ heoff := "--disable-high-entropy-va"
+ if val {
+ dbopt = dbon
+ heopt = heon
+ } else {
+ // Test to see whether "--disable-dynamicbase" works.
+ newer := linkerFlagSupported(ctxt.Arch, argv[0], "", "-Wl,"+dboff)
+ if newer {
+ // Newer compiler, which supports both on/off options.
+ dbopt = dboff
+ heopt = heoff
+ } else {
+ // older toolchain: we have to say nothing in order to
+ // get a no-ASLR binary.
+ dbopt = ""
+ heopt = ""
+ }
+ }
+ if dbopt != "" {
+ argv = append(argv, "-Wl,"+dbopt)
+ }
// enable high-entropy ASLR on 64-bit.
- if ctxt.Arch.PtrSize >= 8 {
- argv = append(argv, "-Wl,--high-entropy-va")
+ if ctxt.Arch.PtrSize >= 8 && heopt != "" {
+ argv = append(argv, "-Wl,"+heopt)
}
return argv
}
if ctxt.HeadType == objabi.Hdarwin {
if machoPlatform == PLATFORM_MACOS && ctxt.IsAMD64() {
argv = append(argv, "-Wl,-no_pie")
- argv = append(argv, "-Wl,-pagezero_size,4000000")
}
}
+ if *flagRace && ctxt.HeadType == objabi.Hwindows {
+ // Current windows/amd64 race detector tsan support
+ // library can't handle PIE mode (see #53539 for more details).
+ // For now, explicitly disable PIE (since some compilers
+ // default to it) if -race is in effect.
+ argv = addASLRargs(argv, false)
+ }
case BuildModePIE:
switch ctxt.HeadType {
case objabi.Hdarwin, objabi.Haix:
case objabi.Hwindows:
- argv = addASLRargs(argv)
+ if *flagAslr && *flagRace {
+ // Current windows/amd64 race detector tsan support
+ // library can't handle PIE mode (see #53539 for more details).
+ // Disable alsr if -race in effect.
+ *flagAslr = false
+ }
+ argv = addASLRargs(argv, *flagAslr)
default:
// ELF.
if ctxt.UseRelro() {
}
argv = append(argv, "-shared")
if ctxt.HeadType == objabi.Hwindows {
- if *flagAslr {
- argv = addASLRargs(argv)
- }
+ argv = addASLRargs(argv, *flagAslr)
} else {
// Pass -z nodelete to mark the shared library as
// non-closeable: a dlclose will do nothing.
// We force all symbol resolution to be done at program startup
// because lazy PLT resolution can use large amounts of stack at
// times we cannot allow it to do so.
- argv = append(argv, "-Wl,-znow")
+ argv = append(argv, "-Wl,-z,now")
// Do not let the host linker generate COPY relocations. These
// can move symbols out of sections that rely on stable offsets
// from the beginning of the section (like sym.STYPE).
- argv = append(argv, "-Wl,-znocopyreloc")
+ argv = append(argv, "-Wl,-z,nocopyreloc")
if buildcfg.GOOS == "android" {
// Use lld to avoid errors from default linker (issue #38838)
altLinker = "lld"
}
- if ctxt.Arch.InFamily(sys.ARM, sys.ARM64) && buildcfg.GOOS == "linux" {
- // On ARM, the GNU linker will generate COPY relocations
- // even with -znocopyreloc set.
+ if ctxt.Arch.InFamily(sys.ARM64) && buildcfg.GOOS == "linux" {
+ // On ARM64, the GNU linker will fail with
+ // -znocopyreloc if it thinks a COPY relocation is
+ // required. Switch to gold.
// https://sourceware.org/bugzilla/show_bug.cgi?id=19962
- //
- // On ARM64, the GNU linker will fail instead of
- // generating COPY relocations.
- //
- // In both cases, switch to gold.
+ // https://go.dev/issue/22040
altLinker = "gold"
// If gold is not installed, gcc will silently switch
cmd := exec.Command(name, args...)
if out, err := cmd.CombinedOutput(); err == nil {
if !bytes.Contains(out, []byte("GNU gold")) {
- log.Fatalf("ARM external linker must be gold (issue #15696), but is not: %s", out)
+ log.Fatalf("ARM64 external linker must be gold (issue #15696, 22040), but is not: %s", out)
}
}
}
// Force global symbols to be exported for dlopen, etc.
if ctxt.IsELF {
- argv = append(argv, "-rdynamic")
+ if ctxt.DynlinkingGo() || ctxt.BuildMode == BuildModeCShared || !linkerFlagSupported(ctxt.Arch, argv[0], altLinker, "-Wl,--export-dynamic-symbol=main") {
+ argv = append(argv, "-rdynamic")
+ } else {
+ var exports []string
+ ctxt.loader.ForAllCgoExportDynamic(func(s loader.Sym) {
+ exports = append(exports, "-Wl,--export-dynamic-symbol="+ctxt.loader.SymExtname(s))
+ })
+ sort.Strings(exports)
+ argv = append(argv, exports...)
+ }
}
if ctxt.HeadType == objabi.Haix {
fileName := xcoffCreateExportFile(ctxt)
argv = append(argv, unusedArguments)
}
+ if ctxt.IsWindows() {
+ // Suppress generation of the PE file header timestamp,
+ // so as to avoid spurious build ID differences between
+ // linked binaries that are otherwise identical other than
+ // the date/time they were linked.
+ const noTimeStamp = "-Wl,--no-insert-timestamp"
+ if linkerFlagSupported(ctxt.Arch, argv[0], altLinker, noTimeStamp) {
+ argv = append(argv, noTimeStamp)
+ }
+ }
+
const compressDWARF = "-Wl,--compress-debug-sections=zlib"
if ctxt.compressDWARF && linkerFlagSupported(ctxt.Arch, argv[0], altLinker, compressDWARF) {
argv = append(argv, compressDWARF)
}
argv = append(argv, filepath.Join(*flagTmpdir, "go.o"))
- argv = append(argv, hostobjCopy()...)
+ argv = append(argv, ctxt.hostobjCopy()...)
if ctxt.HeadType == objabi.Haix {
// We want to have C files after Go files to remove
// trampolines csects made by ld.
// case used has specified "-fuse-ld=...".
extld := ctxt.extld()
name, args := extld[0], extld[1:]
- args = append(args, flagExtldflags...)
+ args = append(args, trimLinkerArgv(flagExtldflags)...)
args = append(args, "-Wl,--version")
cmd := exec.Command(name, args...)
usingLLD := false
p := writeGDBLinkerScript()
argv = append(argv, "-Wl,-T,"+p)
}
+ if *flagRace {
+ if p := ctxt.findLibPath("libsynchronization.a"); p != "libsynchronization.a" {
+ argv = append(argv, "-lsynchronization")
+ }
+ }
// libmingw32 and libmingwex have some inter-dependencies,
// so must use linker groups.
argv = append(argv, "-Wl,--start-group", "-lmingwex", "-lmingw32", "-Wl,--end-group")
argv = append(argv, peimporteddlls()...)
}
+ argv = ctxt.passLongArgsInResponseFile(argv, altLinker)
+
if ctxt.Debugvlog != 0 {
ctxt.Logf("host link:")
for _, v := range argv {
if len(out) > 0 {
// always print external output even if the command is successful, so that we don't
// swallow linker warnings (see https://golang.org/issue/17935).
+ if ctxt.IsDarwin() && ctxt.IsAMD64() {
+ const noPieWarning = "ld: warning: -no_pie is deprecated when targeting new OS versions\n"
+ if i := bytes.Index(out, []byte(noPieWarning)); i >= 0 {
+ // swallow -no_pie deprecation warning, issue 54482
+ out = append(out[:i], out[i+len(noPieWarning):]...)
+ }
+ }
+ if ctxt.IsDarwin() {
+ const bindAtLoadWarning = "ld: warning: -bind_at_load is deprecated on macOS\n"
+ if i := bytes.Index(out, []byte(bindAtLoadWarning)); i >= 0 {
+ // -bind_at_load is deprecated with ld-prime, but needed for
+ // correctness with older versions of ld64. Swallow the warning.
+ // TODO: maybe pass -bind_at_load conditionally based on C
+ // linker version.
+ out = append(out[:i], out[i+len(bindAtLoadWarning):]...)
+ }
+ }
ctxt.Logf("%s", out)
}
stripCmd := strings.TrimSuffix(string(out), "\n")
dsym := filepath.Join(*flagTmpdir, "go.dwarf")
- if out, err := exec.Command(dsymutilCmd, "-f", *flagOutfile, "-o", dsym).CombinedOutput(); err != nil {
+ cmd := exec.Command(dsymutilCmd, "-f", *flagOutfile, "-o", dsym)
+ // dsymutil may not clean up its temp directory at exit.
+ // Set DSYMUTIL_REPRODUCER_PATH to work around. see issue 59026.
+ cmd.Env = append(os.Environ(), "DSYMUTIL_REPRODUCER_PATH="+*flagTmpdir)
+ if ctxt.Debugvlog != 0 {
+ ctxt.Logf("host link dsymutil:")
+ for _, v := range cmd.Args {
+ ctxt.Logf(" %q", v)
+ }
+ ctxt.Logf("\n")
+ }
+ if out, err := cmd.CombinedOutput(); err != nil {
Exitf("%s: running dsymutil failed: %v\n%s", os.Args[0], err, out)
}
// Remove STAB (symbolic debugging) symbols after we are done with them (by dsymutil).
// They contain temporary file paths and make the build not reproducible.
- if out, err := exec.Command(stripCmd, "-S", *flagOutfile).CombinedOutput(); err != nil {
+ var stripArgs = []string{"-S"}
+ if debug_s {
+ // We are generating a binary with symbol table suppressed.
+ // Suppress local symbols. We need to keep dynamically exported
+ // and referenced symbols so the dynamic linker can resolve them.
+ stripArgs = append(stripArgs, "-x")
+ }
+ stripArgs = append(stripArgs, *flagOutfile)
+ if ctxt.Debugvlog != 0 {
+ ctxt.Logf("host link strip: %q", stripCmd)
+ for _, v := range stripArgs {
+ ctxt.Logf(" %q", v)
+ }
+ ctxt.Logf("\n")
+ }
+ if out, err := exec.Command(stripCmd, stripArgs...).CombinedOutput(); err != nil {
Exitf("%s: running strip failed: %v\n%s", os.Args[0], err, out)
}
// Skip combining if `dsymutil` didn't generate a file. See #11994.
}
}
+// passLongArgsInResponseFile writes the arguments into a file if they
+// are very long.
+func (ctxt *Link) passLongArgsInResponseFile(argv []string, altLinker string) []string {
+ c := 0
+ for _, arg := range argv {
+ c += len(arg)
+ }
+
+ if c < sys.ExecArgLengthLimit {
+ return argv
+ }
+
+ // Only use response files if they are supported.
+ response := filepath.Join(*flagTmpdir, "response")
+ if err := os.WriteFile(response, nil, 0644); err != nil {
+ log.Fatalf("failed while testing response file: %v", err)
+ }
+ if !linkerFlagSupported(ctxt.Arch, argv[0], altLinker, "@"+response) {
+ if ctxt.Debugvlog != 0 {
+ ctxt.Logf("not using response file because linker does not support one")
+ }
+ return argv
+ }
+
+ var buf bytes.Buffer
+ for _, arg := range argv[1:] {
+ // The external linker response file supports quoted strings.
+ fmt.Fprintf(&buf, "%q\n", arg)
+ }
+ if err := os.WriteFile(response, buf.Bytes(), 0644); err != nil {
+ log.Fatalf("failed while writing response file: %v", err)
+ }
+ if ctxt.Debugvlog != 0 {
+ ctxt.Logf("response file %s contents:\n%s", response, buf.Bytes())
+ }
+ return []string{
+ argv[0],
+ "@" + response,
+ }
+}
+
var createTrivialCOnce sync.Once
func linkerFlagSupported(arch *sys.Arch, linker, altLinker, flag string) bool {
createTrivialCOnce.Do(func() {
src := filepath.Join(*flagTmpdir, "trivial.c")
- if err := ioutil.WriteFile(src, []byte("int main() { return 0; }"), 0666); err != nil {
+ if err := os.WriteFile(src, []byte("int main() { return 0; }"), 0666); err != nil {
Errorf(nil, "WriteFile trivial.c failed: %v", err)
}
})
+ flags := hostlinkArchArgs(arch)
+
+ moreFlags := trimLinkerArgv(append(flagExtldflags, ldflag...))
+ flags = append(flags, moreFlags...)
+
+ if altLinker != "" {
+ flags = append(flags, "-fuse-ld="+altLinker)
+ }
+ trivialPath := filepath.Join(*flagTmpdir, "trivial.c")
+ outPath := filepath.Join(*flagTmpdir, "a.out")
+ flags = append(flags, "-o", outPath, flag, trivialPath)
+
+ cmd := exec.Command(linker, flags...)
+ cmd.Env = append([]string{"LC_ALL=C"}, os.Environ()...)
+ out, err := cmd.CombinedOutput()
+ // GCC says "unrecognized command line option ‘-no-pie’"
+ // clang says "unknown argument: '-no-pie'"
+ return err == nil && !bytes.Contains(out, []byte("unrecognized")) && !bytes.Contains(out, []byte("unknown"))
+}
+
+// trimLinkerArgv returns a new copy of argv that does not include flags
+// that are not relevant for testing whether some linker option works.
+func trimLinkerArgv(argv []string) []string {
flagsWithNextArgSkip := []string{
"-F",
"-l",
"-target",
}
- flags := hostlinkArchArgs(arch)
+ var flags []string
keep := false
skip := false
- for _, f := range append(flagExtldflags, ldflag...) {
+ for _, f := range argv {
if keep {
flags = append(flags, f)
keep = false
}
}
}
-
- if altLinker != "" {
- flags = append(flags, "-fuse-ld="+altLinker)
- }
- flags = append(flags, flag, "trivial.c")
-
- cmd := exec.Command(linker, flags...)
- cmd.Dir = *flagTmpdir
- cmd.Env = append([]string{"LC_ALL=C"}, os.Environ()...)
- out, err := cmd.CombinedOutput()
- // GCC says "unrecognized command line option ‘-no-pie’"
- // clang says "unknown argument: '-no-pie'"
- return err == nil && !bytes.Contains(out, []byte("unrecognized")) && !bytes.Contains(out, []byte("unknown"))
+ return flags
}
// hostlinkArchArgs returns arguments to pass to the external linker
if buildcfg.GOOS == "darwin" {
return []string{"-arch", "arm64"}
}
+ case sys.Loong64:
+ return []string{"-mabi=lp64d"}
case sys.MIPS64:
return []string{"-mabi=64"}
case sys.MIPS:
0xc401, // arm
0x64aa: // arm64
ldpe := func(ctxt *Link, f *bio.Reader, pkg string, length int64, pn string) {
- textp, rsrc, err := loadpe.Load(ctxt.loader, ctxt.Arch, ctxt.IncVersion(), f, pkg, length, pn)
+ ls, err := loadpe.Load(ctxt.loader, ctxt.Arch, ctxt.IncVersion(), f, pkg, length, pn)
if err != nil {
Errorf(nil, "%v", err)
return
}
- if len(rsrc) != 0 {
- setpersrc(ctxt, rsrc)
+ if len(ls.Resources) != 0 {
+ setpersrc(ctxt, ls.Resources)
}
- ctxt.Textp = append(ctxt.Textp, textp...)
+ if ls.PData != 0 {
+ sehp.pdata = append(sehp.pdata, ls.PData)
+ }
+ if ls.XData != 0 {
+ sehp.xdata = append(sehp.xdata, ls.XData)
+ }
+ ctxt.Textp = append(ctxt.Textp, ls.Textp...)
}
return ldhostobj(ldpe, ctxt.HeadType, f, pkg, length, pn, file)
}
// to true if there is an unresolved reference to the symbol in want[K].
func symbolsAreUnresolved(ctxt *Link, want []string) []bool {
returnAllUndefs := -1
- undefs := ctxt.loader.UndefinedRelocTargets(returnAllUndefs)
+ undefs, _ := ctxt.loader.UndefinedRelocTargets(returnAllUndefs)
seen := make(map[loader.Sym]struct{})
rval := make([]bool, len(want))
wantm := make(map[string]int)
if h.ld == nil {
Exitf("unrecognized object file format in %s", path)
}
+ h.file = path
+ h.length = f.MustSeek(0, 2)
f.MustSeek(h.off, 0)
h.ld(ctxt, f, h.pkg, h.length, h.pn)
+ if *flagCaptureHostObjs != "" {
+ captureHostObj(h)
+ }
}
func checkFingerprint(lib *sym.Library, libfp goobj.FingerprintType, src string, srcfp goobj.FingerprintType) {
continue
}
- // Symbols whose names start with "type." are compiler
- // generated, so make functions with that prefix internal.
+ // Symbols whose names start with "type:" are compiler generated,
+ // so make functions with that prefix internal.
ver := 0
symname := elfsym.Name // (unmangled) symbol name
- if elf.ST_TYPE(elfsym.Info) == elf.STT_FUNC && strings.HasPrefix(elfsym.Name, "type.") {
+ if elf.ST_TYPE(elfsym.Info) == elf.STT_FUNC && strings.HasPrefix(elfsym.Name, "type:") {
ver = abiInternalVer
} else if buildcfg.Experiment.RegabiWrappers && elf.ST_TYPE(elfsym.Info) == elf.STT_FUNC {
// Demangle the ABI name. Keep in sync with symtab.go:mangleABIName.
// The decodetype_* functions in decodetype.go need access to
// the type data.
sname := l.SymName(s)
- if strings.HasPrefix(sname, "type.") && !strings.HasPrefix(sname, "type..") {
+ if strings.HasPrefix(sname, "type:") && !strings.HasPrefix(sname, "type:.") {
su.SetData(readelfsymboldata(ctxt, f, &elfsym))
}
}
return sect
}
-type chain struct {
- sym loader.Sym
- up *chain
- limit int // limit on entry to sym
-}
-
-func haslinkregister(ctxt *Link) bool {
- return ctxt.FixedFrameSize() != 0
-}
-
-func callsize(ctxt *Link) int {
- if haslinkregister(ctxt) {
- return 0
- }
- return ctxt.Arch.RegSize
-}
-
-type stkChk struct {
- ldr *loader.Loader
- ctxt *Link
- morestack loader.Sym
- done loader.Bitmap
-}
-
-// Walk the call tree and check that there is always enough stack space
-// for the call frames, especially for a chain of nosplit functions.
-func (ctxt *Link) dostkcheck() {
- ldr := ctxt.loader
- sc := stkChk{
- ldr: ldr,
- ctxt: ctxt,
- morestack: ldr.Lookup("runtime.morestack", 0),
- done: loader.MakeBitmap(ldr.NSym()),
- }
-
- // Every splitting function ensures that there are at least StackLimit
- // bytes available below SP when the splitting prologue finishes.
- // If the splitting function calls F, then F begins execution with
- // at least StackLimit - callsize() bytes available.
- // Check that every function behaves correctly with this amount
- // of stack, following direct calls in order to piece together chains
- // of non-splitting functions.
- var ch chain
- ch.limit = objabi.StackLimit - callsize(ctxt)
- if buildcfg.GOARCH == "arm64" {
- // need extra 8 bytes below SP to save FP
- ch.limit -= 8
- }
-
- // Check every function, but do the nosplit functions in a first pass,
- // to make the printed failure chains as short as possible.
- for _, s := range ctxt.Textp {
- if ldr.IsNoSplit(s) {
- ch.sym = s
- sc.check(&ch, 0)
- }
- }
-
- for _, s := range ctxt.Textp {
- if !ldr.IsNoSplit(s) {
- ch.sym = s
- sc.check(&ch, 0)
- }
- }
-}
-
-func (sc *stkChk) check(up *chain, depth int) int {
- limit := up.limit
- s := up.sym
- ldr := sc.ldr
- ctxt := sc.ctxt
-
- // Don't duplicate work: only need to consider each
- // function at top of safe zone once.
- top := limit == objabi.StackLimit-callsize(ctxt)
- if top {
- if sc.done.Has(s) {
- return 0
- }
- sc.done.Set(s)
- }
-
- if depth > 500 {
- sc.ctxt.Errorf(s, "nosplit stack check too deep")
- sc.broke(up, 0)
- return -1
- }
-
- if ldr.AttrExternal(s) {
- // external function.
- // should never be called directly.
- // onlyctxt.Diagnose the direct caller.
- // TODO(mwhudson): actually think about this.
- // TODO(khr): disabled for now. Calls to external functions can only happen on the g0 stack.
- // See the trampolines in src/runtime/sys_darwin_$ARCH.go.
- //if depth == 1 && ldr.SymType(s) != sym.SXREF && !ctxt.DynlinkingGo() &&
- // ctxt.BuildMode != BuildModeCArchive && ctxt.BuildMode != BuildModePIE && ctxt.BuildMode != BuildModeCShared && ctxt.BuildMode != BuildModePlugin {
- // Errorf(s, "call to external function")
- //}
- return -1
- }
- info := ldr.FuncInfo(s)
- if !info.Valid() { // external function. see above.
- return -1
- }
-
- if limit < 0 {
- sc.broke(up, limit)
- return -1
- }
-
- // morestack looks like it calls functions,
- // but it switches the stack pointer first.
- if s == sc.morestack {
- return 0
- }
-
- var ch chain
- ch.up = up
-
- if !ldr.IsNoSplit(s) {
- // Ensure we have enough stack to call morestack.
- ch.limit = limit - callsize(ctxt)
- ch.sym = sc.morestack
- if sc.check(&ch, depth+1) < 0 {
- return -1
- }
- if !top {
- return 0
- }
- // Raise limit to allow frame.
- locals := info.Locals()
- limit = objabi.StackLimit + int(locals) + int(ctxt.FixedFrameSize())
- }
-
- // Walk through sp adjustments in function, consuming relocs.
- relocs := ldr.Relocs(s)
- var ch1 chain
- pcsp := obj.NewPCIter(uint32(ctxt.Arch.MinLC))
- ri := 0
- for pcsp.Init(ldr.Data(ldr.Pcsp(s))); !pcsp.Done; pcsp.Next() {
- // pcsp.value is in effect for [pcsp.pc, pcsp.nextpc).
-
- // Check stack size in effect for this span.
- if int32(limit)-pcsp.Value < 0 {
- sc.broke(up, int(int32(limit)-pcsp.Value))
- return -1
- }
-
- // Process calls in this span.
- for ; ri < relocs.Count(); ri++ {
- r := relocs.At(ri)
- if uint32(r.Off()) >= pcsp.NextPC {
- break
- }
- t := r.Type()
- switch {
- case t.IsDirectCall():
- ch.limit = int(int32(limit) - pcsp.Value - int32(callsize(ctxt)))
- ch.sym = r.Sym()
- if sc.check(&ch, depth+1) < 0 {
- return -1
- }
-
- // Indirect call. Assume it is a call to a splitting function,
- // so we have to make sure it can call morestack.
- // Arrange the data structures to report both calls, so that
- // if there is an error, stkprint shows all the steps involved.
- case t == objabi.R_CALLIND:
- ch.limit = int(int32(limit) - pcsp.Value - int32(callsize(ctxt)))
- ch.sym = 0
- ch1.limit = ch.limit - callsize(ctxt) // for morestack in called prologue
- ch1.up = &ch
- ch1.sym = sc.morestack
- if sc.check(&ch1, depth+2) < 0 {
- return -1
- }
- }
- }
- }
-
- return 0
-}
-
-func (sc *stkChk) broke(ch *chain, limit int) {
- sc.ctxt.Errorf(ch.sym, "nosplit stack overflow")
- sc.print(ch, limit)
-}
-
-func (sc *stkChk) print(ch *chain, limit int) {
- ldr := sc.ldr
- ctxt := sc.ctxt
- var name string
- if ch.sym != 0 {
- name = fmt.Sprintf("%s<%d>", ldr.SymName(ch.sym), ldr.SymVersion(ch.sym))
- if ldr.IsNoSplit(ch.sym) {
- name += " (nosplit)"
- }
- } else {
- name = "function pointer"
- }
-
- if ch.up == nil {
- // top of chain. ch.sym != 0.
- if ldr.IsNoSplit(ch.sym) {
- fmt.Printf("\t%d\tassumed on entry to %s\n", ch.limit, name)
- } else {
- fmt.Printf("\t%d\tguaranteed after split check in %s\n", ch.limit, name)
- }
- } else {
- sc.print(ch.up, ch.limit+callsize(ctxt))
- if !haslinkregister(ctxt) {
- fmt.Printf("\t%d\ton entry to %s\n", ch.limit, name)
- }
- }
-
- if ch.limit != limit {
- fmt.Printf("\t%d\tafter %s uses %d\n", limit, name, ch.limit-limit)
- }
-}
-
func usage() {
fmt.Fprintf(os.Stderr, "usage: link [options] main.o\n")
objabi.Flagprint(os.Stderr)
}
ldr := ctxt.loader
s := ldr.Lookup(a, 0)
+ if s == 0 {
+ Errorf(nil, "missing entry symbol %q", a)
+ return 0
+ }
st := ldr.SymType(s)
if st == 0 {
return *FlagTextAddr
ldr.Errorf(s, "addgotsym: unsupported binary format")
}
}
+
+var hostobjcounter int
+
+// captureHostObj writes out the content of a host object (pulled from
+// an archive or loaded from a *.o file directly) to a directory
+// specified via the linker's "-capturehostobjs" debugging flag. This
+// is intended to make it easier for a developer to inspect the actual
+// object feeding into "CGO internal" link step.
+func captureHostObj(h *Hostobj) {
+ // Form paths for info file and obj file.
+ ofile := fmt.Sprintf("captured-obj-%d.o", hostobjcounter)
+ ifile := fmt.Sprintf("captured-obj-%d.txt", hostobjcounter)
+ hostobjcounter++
+ opath := filepath.Join(*flagCaptureHostObjs, ofile)
+ ipath := filepath.Join(*flagCaptureHostObjs, ifile)
+
+ // Write the info file.
+ info := fmt.Sprintf("pkg: %s\npn: %s\nfile: %s\noff: %d\nlen: %d\n",
+ h.pkg, h.pn, h.file, h.off, h.length)
+ if err := os.WriteFile(ipath, []byte(info), 0666); err != nil {
+ log.Fatalf("error writing captured host obj info %s: %v", ipath, err)
+ }
+
+ readObjData := func() []byte {
+ inf, err := os.Open(h.file)
+ if err != nil {
+ log.Fatalf("capturing host obj: open failed on %s: %v", h.pn, err)
+ }
+ res := make([]byte, h.length)
+ if n, err := inf.ReadAt(res, h.off); err != nil || n != int(h.length) {
+ log.Fatalf("capturing host obj: readat failed on %s: %v", h.pn, err)
+ }
+ return res
+ }
+
+ // Write the object file.
+ if err := os.WriteFile(opath, readObjData(), 0666); err != nil {
+ log.Fatalf("error writing captured host object %s: %v", opath, err)
+ }
+
+ fmt.Fprintf(os.Stderr, "link: info: captured host object %s to %s\n",
+ h.file, opath)
+}