run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2021 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 // Targets runner
  19
  20 package main
  21
  22 import (
  23         "bufio"
  24         "errors"
  25         "flag"
  26         "fmt"
  27         "io"
  28         "log"
  29         "os"
  30         "os/exec"
  31         "path"
  32         "path/filepath"
  33         "strconv"
  34         "strings"
  35         "sync"
  36         "syscall"
  37         "time"
  38
  39         "go.cypherpunks.ru/recfile"
  40         "go.cypherpunks.ru/tai64n/v2"
  41         "golang.org/x/sys/unix"
  42 )
  43
  44 const (
  45         EnvDepFd        = "REDO_DEP_FD"
  46         EnvDirPrefix    = "REDO_DIRPREFIX"
  47         EnvDepCwd       = "REDO_DEP_CWD"
  48         EnvBuildUUID    = "REDO_BUILD_UUID"
  49         EnvStderrPrefix = "REDO_STDERR_PREFIX"
  50         EnvTrace        = "REDO_TRACE"
  51         EnvStderrKeep   = "REDO_LOGS"
  52         EnvStderrSilent = "REDO_SILENT"
  53         EnvNoSync       = "REDO_NO_SYNC"
  54
  55         RedoDir      = ".redo"
  56         LockSuffix   = ".lock"
  57         DepSuffix    = ".rec"
  58         TmpPrefix    = ".redo."
  59         LogSuffix    = ".log"
  60         LogRecSuffix = ".log-rec"
  61 )
  62
  63 var (
  64         NoSync       bool = false
  65         StderrKeep   bool = false
  66         StderrSilent bool = false
  67         StderrPrefix string
  68         Jobs         sync.WaitGroup
  69
  70         flagTrace        *bool
  71         flagTraceAll     *bool
  72         flagStderrKeep   *bool
  73         flagStderrSilent *bool
  74
  75         TracedAll bool
  76 )
  77
  78 func init() {
  79         cmdName := CmdName()
  80         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  81                 return
  82         }
  83         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  84         flagTraceAll = flag.Bool("xx", false,
  85                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  86         flagStderrKeep = flag.Bool("k", false,
  87                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  88         flagStderrSilent = flag.Bool("s", false,
  89                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
  90 }
  91
  92 type RunErr struct {
  93         Tgt      string
  94         DoFile   string
  95         Started  *time.Time
  96         Finished *time.Time
  97         Err      error
  98 }
  99
 100 func (e *RunErr) Name() string {
 101         var name string
 102         if e.DoFile == "" {
 103                 name = e.Tgt
 104         } else {
 105                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 106         }
 107         if e.Finished == nil {
 108                 return name
 109         }
 110         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 111 }
 112
 113 func (e RunErr) Error() string {
 114         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 115 }
 116
 117 func mkdirs(pth string) error {
 118         if _, err := os.Stat(pth); err == nil {
 119                 return nil
 120         }
 121         return os.MkdirAll(pth, os.FileMode(0777))
 122 }
 123
 124 func isModified(cwd, redoDir, tgt string) (bool, *Inode, error) {
 125         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 126         if err != nil {
 127                 if os.IsNotExist(err) {
 128                         return false, nil, nil
 129                 }
 130                 return false, nil, err
 131         }
 132         defer fdDep.Close()
 133         r := recfile.NewReader(fdDep)
 134         var ourInode *Inode
 135         for {
 136                 m, err := r.NextMap()
 137                 if err != nil {
 138                         if err == io.EOF {
 139                                 break
 140                         }
 141                         return false, nil, err
 142                 }
 143                 if m["Target"] != tgt {
 144                         continue
 145                 }
 146                 fd, err := os.Open(path.Join(cwd, tgt))
 147                 if err != nil {
 148                         if os.IsNotExist(err) {
 149                                 return false, nil, nil
 150                         }
 151                         return false, nil, err
 152                 }
 153                 ourInode, err = inodeFromFile(fd)
 154                 fd.Close()
 155                 if err != nil {
 156                         return false, nil, err
 157                 }
 158                 theirInode, err := inodeFromRec(m)
 159                 if err != nil {
 160                         return false, nil, err
 161                 }
 162                 if !ourInode.Equals(theirInode) {
 163                         return true, ourInode, nil
 164                 }
 165                 break
 166         }
 167         return false, ourInode, nil
 168 }
 169
 170 func syncDir(dir string) error {
 171         fd, err := os.Open(dir)
 172         if err != nil {
 173                 return err
 174         }
 175         err = fd.Sync()
 176         fd.Close()
 177         return err
 178 }
 179
 180 func runScript(tgtOrig string, errs chan error, traced bool) error {
 181         cwd, tgt := cwdAndTgt(tgtOrig)
 182         redoDir := path.Join(cwd, RedoDir)
 183         if err := mkdirs(redoDir); err != nil {
 184                 return TgtErr{tgtOrig, err}
 185         }
 186
 187         // Acquire lock
 188         fdLock, err := os.OpenFile(
 189                 path.Join(redoDir, tgt+LockSuffix),
 190                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 191                 os.FileMode(0666),
 192         )
 193         if err != nil {
 194                 return TgtErr{tgtOrig, err}
 195         }
 196         lockRelease := func() {
 197                 trace(CLock, "LOCK_UN: %s", fdLock.Name())
 198                 unix.Flock(int(fdLock.Fd()), unix.LOCK_UN)
 199                 fdLock.Close()
 200         }
 201         trace(CLock, "LOCK_NB: %s", fdLock.Name())
 202
 203         // Waiting for job completion, already taken by someone else
 204         if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
 205                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
 206                         fdLock.Close()
 207                         return TgtErr{tgtOrig, err}
 208                 }
 209                 Jobs.Add(1)
 210                 trace(CDebug, "waiting: %s", tgtOrig)
 211                 if FdStatus != nil {
 212                         FdStatus.Write([]byte{StatusWait})
 213                 }
 214                 go func() {
 215                         defer Jobs.Done()
 216                         trace(CLock, "LOCK_EX: %s", fdLock.Name())
 217                         unix.Flock(int(fdLock.Fd()), unix.LOCK_EX)
 218                         lockRelease()
 219                         trace(CDebug, "waiting done: %s", tgtOrig)
 220                         if FdStatus != nil {
 221                                 FdStatus.Write([]byte{StatusWaited})
 222                         }
 223                         var depInfo *DepInfo
 224                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 225                         if err != nil {
 226                                 if os.IsNotExist(err) {
 227                                         err = errors.New("was not built: no .rec")
 228                                 }
 229                                 goto Finish
 230                         }
 231                         defer fdDep.Close()
 232                         depInfo, err = depRead(fdDep)
 233                         if err != nil {
 234                                 goto Finish
 235                         }
 236                         if depInfo.build != BuildUUID {
 237                                 err = errors.New("was not built: build differs")
 238                         }
 239                 Finish:
 240                         if err != nil {
 241                                 err = TgtErr{tgtOrig, err}
 242                         }
 243                         errs <- err
 244                 }()
 245                 return nil
 246         }
 247
 248         // Check if target is not modified externally
 249         modified, inodePrev, err := isModified(cwd, redoDir, tgt)
 250         if err != nil {
 251                 lockRelease()
 252                 return TgtErr{tgtOrig, err}
 253         }
 254         if modified {
 255                 trace(CWarn, "%s externally modified: not redoing", tgtOrig)
 256                 lockRelease()
 257                 go func() {
 258                         errs <- nil
 259                 }()
 260                 return nil
 261         }
 262
 263         // Start preparing .rec
 264         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 265         if err != nil {
 266                 lockRelease()
 267                 return TgtErr{tgtOrig, err}
 268         }
 269         fdDepPath := fdDep.Name()
 270         cleanup := func() {
 271                 lockRelease()
 272                 fdDep.Close()
 273                 os.Remove(fdDep.Name())
 274         }
 275         if _, err = recfile.NewWriter(fdDep).WriteFields(
 276                 recfile.Field{Name: "Build", Value: BuildUUID},
 277         ); err != nil {
 278                 cleanup()
 279                 return TgtErr{tgtOrig, err}
 280         }
 281
 282         // Find .do
 283         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 284         if err != nil {
 285                 cleanup()
 286                 return TgtErr{tgtOrig, err}
 287         }
 288         if doFile == "" {
 289                 cleanup()
 290                 return TgtErr{tgtOrig, errors.New("no .do found")}
 291         }
 292
 293         // Determine basename and DIRPREFIX
 294         doFileRelPath := doFile
 295         ents := strings.Split(cwd, "/")
 296         ents = ents[len(ents)-upLevels:]
 297         dirPrefix := path.Join(ents...)
 298         cwdOrig := cwd
 299         for i := 0; i < upLevels; i++ {
 300                 cwd = path.Join(cwd, "..")
 301                 doFileRelPath = path.Join("..", doFileRelPath)
 302         }
 303         cwd = path.Clean(cwd)
 304         doFilePath := path.Join(cwd, doFile)
 305         basename := tgt
 306         runErr := RunErr{Tgt: tgtOrig}
 307         if strings.HasPrefix(doFile, "default.") {
 308                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 309                 runErr.DoFile = doFileRelPath
 310         }
 311
 312         if err = writeDep(fdDep, cwdOrig, doFileRelPath); err != nil {
 313                 cleanup()
 314                 return TgtErr{tgtOrig, err}
 315         }
 316         fdDep.Close()
 317         trace(CWait, "%s", runErr.Name())
 318
 319         // Prepare command line
 320         var cmdName string
 321         var args []string
 322         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 323                 cmdName = doFilePath
 324                 args = make([]string, 0, 3)
 325         } else {
 326                 cmdName = "/bin/sh"
 327                 if traced || TracedAll {
 328                         args = append(args, "-ex")
 329                 } else {
 330                         args = append(args, "-e")
 331                 }
 332                 args = append(args, doFile)
 333         }
 334
 335         // Temporary file for stdout
 336         fdStdout, err := tempfile(cwdOrig, tgt)
 337         if err != nil {
 338                 cleanup()
 339                 return TgtErr{tgtOrig, err}
 340         }
 341         stdoutPath := fdStdout.Name()
 342         fdStdout.Close()
 343         tmpPath := stdoutPath + ".3" // and for $3
 344         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 345         if err != nil {
 346                 panic(err)
 347         }
 348         args = append(
 349                 args,
 350                 path.Join(dirPrefix, tgt),
 351                 path.Join(dirPrefix, basename),
 352                 tmpPathRel,
 353         )
 354
 355         cmd := exec.Command(cmdName, args...)
 356         cmd.Dir = cwd
 357         // cmd.Stdin reads from /dev/null by default
 358         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 359         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 360         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 361
 362         childStderrPrefix := tempsuffix()
 363         cmd.Env = append(cmd.Env, fmt.Sprintf(
 364                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 365         ))
 366
 367         fdNum := 0
 368         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 369         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 370         fdNum++
 371         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 372         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 373         fdNum++
 374
 375         if FdStatus == nil {
 376                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 377         } else {
 378                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 379                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 380                 fdNum++
 381         }
 382
 383         // Preparing stderr
 384         var fdStderr *os.File
 385         if StderrKeep {
 386                 fdStderr, err = os.OpenFile(
 387                         path.Join(redoDir, tgt+LogSuffix),
 388                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 389                         os.FileMode(0666),
 390                 )
 391                 if err != nil {
 392                         cleanup()
 393                         return TgtErr{tgtOrig, err}
 394                 }
 395         }
 396         shCtx := fmt.Sprintf(
 397                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 398                 tgtOrig, cmdName, args, cwd, dirPrefix,
 399         )
 400         trace(CDebug, "%s", shCtx)
 401
 402         Jobs.Add(1)
 403         go func() {
 404                 jsToken := jsAcquire(shCtx)
 405                 if JSR == nil {
 406                         // infinite jobs
 407                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 408                 } else {
 409                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 410                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 411                         makeFlags := fmt.Sprintf(
 412                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 413                         )
 414                         makeFlags = strings.Trim(makeFlags, " ")
 415                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 416                         fdNum += 2
 417                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 418                 }
 419
 420                 if FdStatus != nil {
 421                         FdStatus.Write([]byte{StatusRun})
 422                 }
 423
 424                 var finished time.Time
 425                 var exitErr *exec.ExitError
 426                 started := time.Now()
 427                 runErr.Started = &started
 428                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 429                 if err != nil {
 430                         runErr.Err = err
 431                         errs <- runErr
 432                         return
 433                 }
 434                 cmd.Stdout = fdStdout
 435                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 436                 if err != nil {
 437                         runErr.Err = err
 438                         errs <- runErr
 439                         return
 440                 }
 441                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 442                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 443                 fdNum++
 444                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 445
 446                 defer func() {
 447                         jsRelease(shCtx, jsToken)
 448                         fdDep.Close()
 449                         fdStdout.Close()
 450                         if fdStderr != nil {
 451                                 fdStderr.Close()
 452                                 logRecPath := path.Join(redoDir, tgt+LogRecSuffix)
 453                                 if fdStderr, err = os.OpenFile(
 454                                         logRecPath,
 455                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 456                                         os.FileMode(0666),
 457                                 ); err == nil {
 458                                         fields := []recfile.Field{
 459                                                 {Name: "Build", Value: BuildUUID},
 460                                                 {Name: "PID", Value: strconv.Itoa(cmd.Process.Pid)},
 461                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 462                                                 {Name: "Cwd", Value: cwd},
 463                                         }
 464                                         ts := new(tai64n.TAI64N)
 465                                         ts.FromTime(started)
 466                                         fields = append(fields,
 467                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 468                                         )
 469                                         ts.FromTime(finished)
 470                                         fields = append(fields,
 471                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 472                                         fields = append(fields, recfile.Field{
 473                                                 Name:  "Duration",
 474                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 475                                         })
 476                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 477                                         for _, arg := range args {
 478                                                 fields = append(fields, recfile.Field{Name: "Cmd", Value: arg})
 479                                         }
 480                                         for _, env := range cmd.Env {
 481                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 482                                         }
 483                                         if exitErr != nil {
 484                                                 fields = append(fields, recfile.Field{
 485                                                         Name:  "ExitCode",
 486                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 487                                                 })
 488                                         }
 489                                         w := bufio.NewWriter(fdStderr)
 490
 491                                         var depInfo *DepInfo
 492                                         fdDep, err := os.Open(fdDepPath)
 493                                         if err != nil {
 494                                                 goto Err
 495                                         }
 496                                         depInfo, err = depRead(fdDep)
 497                                         fdDep.Close()
 498                                         if err != nil {
 499                                                 goto Err
 500                                         }
 501                                         for _, dep := range depInfo.ifchanges {
 502                                                 fields = append(fields, recfile.Field{
 503                                                         Name:  "Ifchange",
 504                                                         Value: dep["Target"],
 505                                                 })
 506                                         }
 507                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 508                                         if err != nil {
 509                                                 goto Err
 510                                         }
 511                                         err = w.Flush()
 512                                 Err:
 513                                         if err != nil {
 514                                                 log.Println(err)
 515                                                 os.Remove(logRecPath)
 516                                         }
 517                                         fdStderr.Close()
 518                                 } else {
 519                                         log.Println("can not open", logRecPath, ":", err)
 520                                 }
 521                         }
 522                         lockRelease()
 523                         os.Remove(fdDep.Name())
 524                         os.Remove(fdStdout.Name())
 525                         os.Remove(tmpPath)
 526                         os.Remove(fdLock.Name())
 527                         if FdStatus != nil {
 528                                 FdStatus.Write([]byte{StatusDone})
 529                         }
 530                         Jobs.Done()
 531                 }()
 532                 stderr, err := cmd.StderrPipe()
 533                 if err != nil {
 534                         runErr.Err = err
 535                         errs <- runErr
 536                         return
 537                 }
 538                 started = time.Now()
 539                 err = cmd.Start()
 540                 if err != nil {
 541                         runErr.Err = err
 542                         errs <- runErr
 543                         return
 544                 }
 545                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 546                 trace(CDebug, "%s runs %s", tgtOrig, pid)
 547
 548                 stderrTerm := make(chan struct{}, 0)
 549                 go func() {
 550                         scanner := bufio.NewScanner(stderr)
 551                         var line string
 552                         ts := new(tai64n.TAI64N)
 553                         for scanner.Scan() {
 554                                 line = scanner.Text()
 555                                 if strings.HasPrefix(line, childStderrPrefix) {
 556                                         line = line[len(childStderrPrefix):]
 557                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 558                                         continue
 559                                 }
 560                                 if fdStderr != nil {
 561                                         ts.FromTime(time.Now())
 562                                         LogMutex.Lock()
 563                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 564                                         LogMutex.Unlock()
 565                                 }
 566                                 if StderrSilent {
 567                                         continue
 568                                 }
 569                                 if MyPid == 0 {
 570                                         trace(CNone, "%s", line)
 571                                 } else {
 572                                         trace(CNone, "%s %s", pid, line)
 573                                 }
 574                         }
 575                         close(stderrTerm)
 576                 }()
 577
 578                 // Wait for job completion
 579                 <-stderrTerm
 580                 err = cmd.Wait()
 581                 finished = time.Now()
 582                 runErr.Finished = &finished
 583                 if err != nil {
 584                         exitErr = err.(*exec.ExitError)
 585                         runErr.Err = err
 586                         errs <- runErr
 587                         return
 588                 }
 589
 590                 // Was $1 touched?
 591                 if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 592                         errTouched := errors.New("$1 was explicitly touched")
 593                         if inodePrev == nil {
 594                                 fd.Close()
 595                                 runErr.Err = errTouched
 596                                 errs <- runErr
 597                                 return
 598                         } else {
 599                                 inode, err := inodeFromFile(fd)
 600                                 fd.Close()
 601                                 if err != nil {
 602                                         runErr.Err = err
 603                                         errs <- runErr
 604                                         return
 605                                 }
 606                                 if !inode.Equals(inodePrev) {
 607                                         runErr.Err = errTouched
 608                                         errs <- runErr
 609                                         return
 610                                 }
 611                         }
 612                 }
 613
 614                 if inodePrev != nil {
 615                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 616                                 inode, err := inodeFromFile(fd)
 617                                 fd.Close()
 618                                 if err == nil && !inode.Equals(inodePrev) {
 619                                         runErr.Err = errors.New("$1 was explicitly touched")
 620                                         errs <- runErr
 621                                         return
 622                                 }
 623                         }
 624                 }
 625
 626                 // Does it produce both stdout and tmp?
 627                 fiStdout, err := os.Stat(fdStdout.Name())
 628                 if err != nil {
 629                         runErr.Err = err
 630                         errs <- runErr
 631                         return
 632                 }
 633                 tmpExists := false
 634                 _, err = os.Stat(tmpPath)
 635                 if err == nil {
 636                         if fiStdout.Size() > 0 {
 637                                 runErr.Err = errors.New("created both tmp and stdout")
 638                                 errs <- runErr
 639                                 return
 640                         }
 641                         tmpExists = true
 642                 } else if !os.IsNotExist(err) {
 643                         runErr.Err = err
 644                         errs <- runErr
 645                         return
 646                 }
 647
 648                 // Determine what file we must process at last
 649                 var fd *os.File
 650                 if tmpExists {
 651                         fd, err = os.Open(tmpPath)
 652                         if err != nil {
 653                                 goto Finish
 654                         }
 655                         defer fd.Close()
 656                 } else if fiStdout.Size() > 0 {
 657                         fd = fdStdout
 658                 }
 659
 660                 // Do we need to ifcreate it, of ifchange with renaming?
 661                 if fd == nil {
 662                         os.Remove(path.Join(cwdOrig, tgt))
 663                         err = ifcreate(fdDep, tgt)
 664                         if err != nil {
 665                                 goto Finish
 666                         }
 667                 } else {
 668                         if !NoSync {
 669                                 err = fd.Sync()
 670                                 if err != nil {
 671                                         goto Finish
 672                                 }
 673                         }
 674                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 675                         if err != nil {
 676                                 goto Finish
 677                         }
 678                         if !NoSync {
 679                                 err = syncDir(cwdOrig)
 680                                 if err != nil {
 681                                         goto Finish
 682                                 }
 683                         }
 684                         err = writeDep(fdDep, cwdOrig, tgt)
 685                         if err != nil {
 686                                 goto Finish
 687                         }
 688                 }
 689
 690                 // Commit .rec
 691                 if !NoSync {
 692                         err = fdDep.Sync()
 693                         if err != nil {
 694                                 goto Finish
 695                         }
 696                 }
 697                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 698                 err = os.Rename(fdDep.Name(), fdDepPath)
 699                 if err != nil {
 700                         goto Finish
 701                 }
 702                 if !NoSync {
 703                         err = syncDir(redoDir)
 704                         if err != nil {
 705                                 goto Finish
 706                         }
 707                 }
 708         Finish:
 709                 runErr.Err = err
 710                 errs <- runErr
 711         }()
 712         return nil
 713 }
 714
 715 func isOkRun(err error) bool {
 716         if err == nil {
 717                 return true
 718         }
 719         if err, ok := err.(RunErr); ok && err.Err == nil {
 720                 trace(CRedo, "%s", err.Name())
 721                 return true
 722         }
 723         trace(CErr, "%s", err)
 724         return false
 725 }