)

// Implemented in runtime package.
func runtime_BeforeFork()
func runtime_AfterFork()
func runtime_AfterForkInChild()

// Fork, dup fd onto 0..len(fd), and exec(argv0, argvv, envv) in child.
// If a dup or exec fails, write the errno error to pipe.
// (Pipe is close-on-exec so if exec succeeds, it will be closed.)
// In the child, this function must not acquire any locks, because

	goCmd(nil, "build", "-buildmode=plugin", "./plugin2")
	so, err := os.ReadFile("plugin2.so")
	if err != nil {
		log.Panic(err)
	}
	if err := os.WriteFile("plugin2-dup.so", so, 0444); err != nil {
		log.Panic(err)
	}
	prettyPrintf("cp plugin2.so plugin2-dup.so\n")

	goCmd(nil, "build", "-buildmode=plugin", "-o=sub/plugin1.so", "./sub/plugin1")
	goCmd(nil, "build", "-buildmode=plugin", "-o=unnamed1.so", "./unnamed1/main.go")

	upgradeTo := make(map[string]string, len(upgrade))
	for _, u := range upgrade {
		if !pathInList[u.Path] {
			list = append(list, module.Version{Path: u.Path, Version: "none"})
		}
		if prev, dup := upgradeTo[u.Path]; dup {
			upgradeTo[u.Path] = reqs.Max(u.Path, prev, u.Version)
		} else {
			upgradeTo[u.Path] = u.Version
		}
	}

			// now on.
			dupCloexecUnsupported.Store(true)
		default:
			return -1, "fcntl", err
		}
	}
	return dupCloseOnExecOld(fd)
}

// Dup duplicates the file descriptor.
func (fd *FD) Dup() (int, string, error) {
	if err := fd.incref(); err != nil {
		return -1, "", err
	}
	defer fd.decref()
	return DupCloseOnExec(fd.Sysfd)
}

				// to the predefined escaper, use the predefined escaper instead.
				dup := false
				for i, escaper := range s {
					if escFnsEq(esc, escaper) {
						s[i] = idNode.Ident
						dup = true
					}
				}
				if dup {
					// The predefined escaper will already be inserted along with the
					// escapers in s, so do not copy it to the rewritten pipeline.

		} else {
			str = "rpc.Register: type " + sname + " has no exported methods of suitable type"
		}
		log.Print(str)
		return errors.New(str)
	}

	if _, dup := server.serviceMap.LoadOrStore(sname, s); dup {
		return errors.New("rpc: service already defined: " + sname)
	}
	return nil
}

// suitableMethods returns suitable Rpc methods of typ. It will log
// errors if logErr is true.

            methodVisitor.visitVarInsn(Opcodes.ALOAD, 0);
            methodVisitor.visitFieldInsn(Opcodes.GETFIELD, className, META_CLASS_FIELD, META_CLASS_TYPE.getDescriptor());
            methodVisitor.visitInsn(Opcodes.DUP);
            methodVisitor.visitJumpInsn(Opcodes.IFNULL, lookup);
            methodVisitor.visitInsn(Opcodes.ARETURN);

            methodVisitor.visitLabel(lookup);

//sys	Chmod(path string, mode uint32) (err error)
//sys	Chown(path string, uid int, gid int) (err error)
//sys	Chroot(path string) (err error)
//sys	Close(fd int) (err error)
//sys	closedir(dir uintptr) (err error)
//sys	Dup(fd int) (nfd int, err error)
//sys	Dup2(from int, to int) (err error)
//sys	Exchangedata(path1 string, path2 string, options int) (err error)
//sys	Fchdir(fd int) (err error)
//sys	Fchflags(fd int, flags int) (err error)

	}

	if newPos < 0 {
		return 0, errnoErr(EINVAL)
	}

	f.seeked = true
	f.dirIdx = 0 // Reset directory read position. See issue 35767.
	f.pos = newPos
	return newPos, nil
}

func Dup(fd int) (int, error) {
	return 0, ENOSYS
}

func Dup2(fd, newfd int) error {
	return ENOSYS
}

func Pipe(fd []int) error {
	return ENOSYS
}

	}
	defer f.Close()
	syms, err := f.Symbols()
	if err != nil {
		t.Errorf("error reading symbols %v", err)
		return
	}
	for _, s := range syms {
		if s.Name == ".dup" {
			t.Fatalf("%s contains symbol called .dup", sopath)
		}
	}
}

// The install command should have created a "shlibname" file for the
// listed packages (and runtime/cgo, and math on arm) indicating the