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       = false
  65         StderrKeep   = false
  66         StderrSilent = 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         RunningProcs  = map[int]*os.Process{}
  78         RunningProcsM sync.Mutex
  79
  80         Err1WasTouched = errors.New("$1 was explicitly touched")
  81 )
  82
  83 func init() {
  84         cmdName := CmdName()
  85         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  86                 return
  87         }
  88         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  89         flagTraceAll = flag.Bool("xx", false,
  90                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  91         flagStderrKeep = flag.Bool("k", false,
  92                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  93         flagStderrSilent = flag.Bool("s", false,
  94                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
  95 }
  96
  97 type RunError struct {
  98         Tgt      string
  99         DoFile   string
 100         Started  *time.Time
 101         Finished *time.Time
 102         Err      error
 103 }
 104
 105 func (e *RunError) Name() string {
 106         var name string
 107         if e.DoFile == "" {
 108                 name = e.Tgt
 109         } else {
 110                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 111         }
 112         if e.Finished == nil {
 113                 return name
 114         }
 115         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 116 }
 117
 118 func (e RunError) Error() string {
 119         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 120 }
 121
 122 func mkdirs(pth string) error {
 123         if _, err := os.Stat(pth); err == nil {
 124                 return nil
 125         }
 126         return os.MkdirAll(pth, os.FileMode(0777))
 127 }
 128
 129 func isModified(cwd, redoDir, tgt string) (bool, *Inode, error) {
 130         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 131         if err != nil {
 132                 if os.IsNotExist(err) {
 133                         return false, nil, nil
 134                 }
 135                 return false, nil, err
 136         }
 137         defer fdDep.Close()
 138         r := recfile.NewReader(fdDep)
 139         var ourInode *Inode
 140         for {
 141                 m, err := r.NextMap()
 142                 if err != nil {
 143                         if errors.Is(err, io.EOF) {
 144                                 break
 145                         }
 146                         return false, nil, err
 147                 }
 148                 if m["Type"] != DepTypeIfchange || m["Target"] != tgt {
 149                         continue
 150                 }
 151                 fd, err := os.Open(path.Join(cwd, tgt))
 152                 if err != nil {
 153                         if os.IsNotExist(err) {
 154                                 return false, nil, nil
 155                         }
 156                         return false, nil, err
 157                 }
 158                 ourInode, err = inodeFromFile(fd)
 159                 fd.Close()
 160                 if err != nil {
 161                         return false, nil, err
 162                 }
 163                 theirInode, err := inodeFromRec(m)
 164                 if err != nil {
 165                         return false, nil, err
 166                 }
 167                 if !ourInode.Equals(theirInode) {
 168                         return true, ourInode, nil
 169                 }
 170                 break
 171         }
 172         return false, ourInode, nil
 173 }
 174
 175 func syncDir(dir string) error {
 176         fd, err := os.Open(dir)
 177         if err != nil {
 178                 return err
 179         }
 180         err = fd.Sync()
 181         fd.Close()
 182         return err
 183 }
 184
 185 func runScript(tgtOrig string, errs chan error, traced bool) error {
 186         cwd, tgt := cwdAndTgt(tgtOrig)
 187         redoDir := path.Join(cwd, RedoDir)
 188         if err := mkdirs(redoDir); err != nil {
 189                 return TgtError{tgtOrig, err}
 190         }
 191
 192         // Acquire lock
 193         fdLock, err := os.OpenFile(
 194                 path.Join(redoDir, tgt+LockSuffix),
 195                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 196                 os.FileMode(0666),
 197         )
 198         if err != nil {
 199                 return TgtError{tgtOrig, err}
 200         }
 201         lockRelease := func() {
 202                 tracef(CLock, "LOCK_UN: %s", fdLock.Name())
 203                 if err := unix.Flock(int(fdLock.Fd()), unix.LOCK_UN); err != nil {
 204                         log.Fatalln(err)
 205                 }
 206                 fdLock.Close()
 207         }
 208         tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 209
 210         // Waiting for job completion, already taken by someone else
 211         if err = unix.Flock(int(fdLock.Fd()), unix.LOCK_EX|unix.LOCK_NB); err != nil {
 212                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EWOULDBLOCK) {
 213                         fdLock.Close()
 214                         return TgtError{tgtOrig, err}
 215                 }
 216                 Jobs.Add(1)
 217                 tracef(CDebug, "waiting: %s", tgtOrig)
 218                 if FdStatus != nil {
 219                         if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
 220                                 log.Fatalln(err)
 221                         }
 222                 }
 223                 go func() {
 224                         defer Jobs.Done()
 225                         tracef(CLock, "LOCK_EX: %s", fdLock.Name())
 226                         if err := unix.Flock(int(fdLock.Fd()), unix.LOCK_EX); err != nil {
 227                                 log.Fatalln(err)
 228                         }
 229                         lockRelease()
 230                         tracef(CDebug, "waiting done: %s", tgtOrig)
 231                         if FdStatus != nil {
 232                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 233                                         log.Fatalln(err)
 234                                 }
 235                         }
 236                         var depInfo *DepInfo
 237                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 238                         if err != nil {
 239                                 if os.IsNotExist(err) {
 240                                         err = errors.New("was not built: no .rec")
 241                                 }
 242                                 goto Finish
 243                         }
 244                         defer fdDep.Close()
 245                         depInfo, err = depRead(fdDep)
 246                         if err != nil {
 247                                 goto Finish
 248                         }
 249                         if depInfo.build != BuildUUID {
 250                                 err = errors.New("was not built: build differs")
 251                         }
 252                 Finish:
 253                         if err != nil {
 254                                 err = TgtError{tgtOrig, err}
 255                         }
 256                         errs <- err
 257                 }()
 258                 return nil
 259         }
 260
 261         // Check if target is not modified externally
 262         modified, inodePrev, err := isModified(cwd, redoDir, tgt)
 263         if err != nil {
 264                 lockRelease()
 265                 return TgtError{tgtOrig, err}
 266         }
 267         if modified {
 268                 tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 269                 lockRelease()
 270                 go func() {
 271                         errs <- nil
 272                 }()
 273                 return nil
 274         }
 275
 276         // Start preparing .rec
 277         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 278         if err != nil {
 279                 lockRelease()
 280                 return TgtError{tgtOrig, err}
 281         }
 282         fdDepPath := fdDep.Name()
 283         cleanup := func() {
 284                 lockRelease()
 285                 fdDep.Close()
 286                 os.Remove(fdDep.Name())
 287         }
 288         if _, err = recfile.NewWriter(fdDep).WriteFields(
 289                 recfile.Field{Name: "Build", Value: BuildUUID},
 290         ); err != nil {
 291                 cleanup()
 292                 return TgtError{tgtOrig, err}
 293         }
 294
 295         // Find .do
 296         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 297         if err != nil {
 298                 cleanup()
 299                 return TgtError{tgtOrig, err}
 300         }
 301         if doFile == "" {
 302                 cleanup()
 303                 return TgtError{tgtOrig, errors.New("no .do found")}
 304         }
 305
 306         // Determine basename and DIRPREFIX
 307         doFileRelPath := doFile
 308         ents := strings.Split(cwd, "/")
 309         ents = ents[len(ents)-upLevels:]
 310         dirPrefix := path.Join(ents...)
 311         cwdOrig := cwd
 312         for i := 0; i < upLevels; i++ {
 313                 cwd = path.Join(cwd, "..")
 314                 doFileRelPath = path.Join("..", doFileRelPath)
 315         }
 316         cwd = path.Clean(cwd)
 317         doFilePath := path.Join(cwd, doFile)
 318         basename := tgt
 319         runErr := RunError{Tgt: tgtOrig}
 320         if strings.HasPrefix(doFile, "default.") {
 321                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 322                 runErr.DoFile = doFileRelPath
 323         }
 324
 325         if err = depWrite(fdDep, cwdOrig, doFileRelPath); err != nil {
 326                 cleanup()
 327                 return TgtError{tgtOrig, err}
 328         }
 329         fdDep.Close()
 330         tracef(CWait, "%s", runErr.Name())
 331
 332         // Prepare command line
 333         var cmdName string
 334         var args []string
 335         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 336                 cmdName = doFilePath
 337                 args = make([]string, 0, 3)
 338         } else {
 339                 cmdName = "/bin/sh"
 340                 if traced || TracedAll {
 341                         args = append(args, "-ex")
 342                 } else {
 343                         args = append(args, "-e")
 344                 }
 345                 args = append(args, doFile)
 346         }
 347
 348         // Temporary file for stdout
 349         fdStdout, err := tempfile(cwdOrig, tgt)
 350         if err != nil {
 351                 cleanup()
 352                 return TgtError{tgtOrig, err}
 353         }
 354         stdoutPath := fdStdout.Name()
 355         fdStdout.Close()
 356         tmpPath := stdoutPath + ".3" // and for $3
 357         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 358         if err != nil {
 359                 panic(err)
 360         }
 361         args = append(
 362                 args,
 363                 path.Join(dirPrefix, tgt),
 364                 path.Join(dirPrefix, basename),
 365                 tmpPathRel,
 366         )
 367
 368         cmd := exec.Command(cmdName, args...)
 369         cmd.Dir = cwd
 370         // cmd.Stdin reads from /dev/null by default
 371         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 372         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 373         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 374
 375         childStderrPrefix := tempsuffix()
 376         cmd.Env = append(cmd.Env, fmt.Sprintf(
 377                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 378         ))
 379
 380         fdNum := 0
 381         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 382         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 383         fdNum++
 384         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 385         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 386         fdNum++
 387
 388         if FdStatus == nil {
 389                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 390         } else {
 391                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 392                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 393                 fdNum++
 394         }
 395
 396         // Preparing stderr
 397         var fdStderr *os.File
 398         if StderrKeep {
 399                 fdStderr, err = os.OpenFile(
 400                         path.Join(redoDir, tgt+LogSuffix),
 401                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 402                         os.FileMode(0666),
 403                 )
 404                 if err != nil {
 405                         cleanup()
 406                         return TgtError{tgtOrig, err}
 407                 }
 408         }
 409         shCtx := fmt.Sprintf(
 410                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 411                 tgtOrig, cmdName, args, cwd, dirPrefix,
 412         )
 413         tracef(CDebug, "%s", shCtx)
 414
 415         Jobs.Add(1)
 416         go func() {
 417                 jsToken := jsAcquire(shCtx)
 418                 if JSR == nil {
 419                         // infinite jobs
 420                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 421                 } else {
 422                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 423                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 424                         makeFlags := fmt.Sprintf(
 425                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 426                         )
 427                         makeFlags = strings.Trim(makeFlags, " ")
 428                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 429                         fdNum += 2
 430                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 431                 }
 432
 433                 if FdStatus != nil {
 434                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 435                                 log.Fatalln(err)
 436                         }
 437                 }
 438
 439                 var finished time.Time
 440                 var exitErr *exec.ExitError
 441                 started := time.Now()
 442                 runErr.Started = &started
 443                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 444                 if err != nil {
 445                         runErr.Err = err
 446                         errs <- runErr
 447                         return
 448                 }
 449                 cmd.Stdout = fdStdout
 450                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 451                 if err != nil {
 452                         runErr.Err = err
 453                         errs <- runErr
 454                         return
 455                 }
 456                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 457                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 458                 fdNum++
 459                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 460
 461                 defer func() {
 462                         jsRelease(shCtx, jsToken)
 463                         fdDep.Close()
 464                         fdStdout.Close()
 465                         if fdStderr != nil {
 466                                 fdStderr.Close()
 467                                 logRecPath := path.Join(redoDir, tgt+LogRecSuffix)
 468                                 if fdStderr, err = os.OpenFile(
 469                                         logRecPath,
 470                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 471                                         os.FileMode(0666),
 472                                 ); err == nil {
 473                                         fields := []recfile.Field{
 474                                                 {Name: "Build", Value: BuildUUID},
 475                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 476                                                 {Name: "Cwd", Value: cwd},
 477                                         }
 478                                         if cmd.Process != nil {
 479                                                 fields = append(fields, recfile.Field{
 480                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 481                                                 })
 482                                         }
 483                                         ts := new(tai64n.TAI64N)
 484                                         ts.FromTime(started)
 485                                         fields = append(fields,
 486                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 487                                         )
 488                                         ts.FromTime(finished)
 489                                         fields = append(fields,
 490                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 491                                         fields = append(fields, recfile.Field{
 492                                                 Name:  "Duration",
 493                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 494                                         })
 495                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 496                                         for _, arg := range args {
 497                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 498                                         }
 499                                         for _, env := range cmd.Env {
 500                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 501                                         }
 502                                         if exitErr != nil {
 503                                                 fields = append(fields, recfile.Field{
 504                                                         Name:  "ExitCode",
 505                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 506                                                 })
 507                                         }
 508                                         w := bufio.NewWriter(fdStderr)
 509
 510                                         var depInfo *DepInfo
 511                                         fdDep, err := os.Open(fdDepPath)
 512                                         if err != nil {
 513                                                 goto Err
 514                                         }
 515                                         depInfo, err = depRead(fdDep)
 516                                         fdDep.Close()
 517                                         if err != nil {
 518                                                 goto Err
 519                                         }
 520                                         for _, dep := range depInfo.ifchanges {
 521                                                 fields = append(fields, recfile.Field{
 522                                                         Name:  "Ifchange",
 523                                                         Value: dep["Target"],
 524                                                 })
 525                                         }
 526                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 527                                         if err != nil {
 528                                                 goto Err
 529                                         }
 530                                         err = w.Flush()
 531                                 Err:
 532                                         if err != nil {
 533                                                 log.Println(err)
 534                                                 os.Remove(logRecPath)
 535                                         }
 536                                         fdStderr.Close()
 537                                 } else {
 538                                         log.Println("can not open", logRecPath, ":", err)
 539                                 }
 540                         }
 541                         lockRelease()
 542                         os.Remove(fdDep.Name())
 543                         os.Remove(fdStdout.Name())
 544                         os.Remove(tmpPath)
 545                         os.Remove(fdLock.Name())
 546                         if FdStatus != nil {
 547                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 548                                         log.Fatalln(err)
 549                                 }
 550                         }
 551                         Jobs.Done()
 552                 }()
 553                 stderr, err := cmd.StderrPipe()
 554                 if err != nil {
 555                         runErr.Err = err
 556                         errs <- runErr
 557                         return
 558                 }
 559                 started = time.Now()
 560                 err = cmd.Start()
 561                 if err != nil {
 562                         runErr.Err = err
 563                         errs <- runErr
 564                         return
 565                 }
 566                 RunningProcsM.Lock()
 567                 RunningProcs[cmd.Process.Pid] = cmd.Process
 568                 RunningProcsM.Unlock()
 569                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 570                 tracef(CDebug, "%s runs %s", tgtOrig, pid)
 571
 572                 stderrTerm := make(chan struct{})
 573                 go func() {
 574                         scanner := bufio.NewScanner(stderr)
 575                         var line string
 576                         ts := new(tai64n.TAI64N)
 577                         for scanner.Scan() {
 578                                 line = scanner.Text()
 579                                 if strings.HasPrefix(line, childStderrPrefix) {
 580                                         line = line[len(childStderrPrefix):]
 581                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 582                                         continue
 583                                 }
 584                                 if fdStderr != nil {
 585                                         ts.FromTime(time.Now())
 586                                         LogMutex.Lock()
 587                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 588                                         LogMutex.Unlock()
 589                                 }
 590                                 if StderrSilent {
 591                                         continue
 592                                 }
 593                                 if MyPid == 0 {
 594                                         tracef(CNone, "%s", line)
 595                                 } else {
 596                                         tracef(CNone, "%s %s", pid, line)
 597                                 }
 598                         }
 599                         close(stderrTerm)
 600                 }()
 601
 602                 // Wait for job completion
 603                 <-stderrTerm
 604                 err = cmd.Wait()
 605                 RunningProcsM.Lock()
 606                 delete(RunningProcs, cmd.Process.Pid)
 607                 RunningProcsM.Unlock()
 608                 finished = time.Now()
 609                 runErr.Finished = &finished
 610                 if err != nil {
 611                         exitErr = err.(*exec.ExitError)
 612                         runErr.Err = err
 613                         errs <- runErr
 614                         return
 615                 }
 616
 617                 // Was $1 touched?
 618                 if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 619                         errTouched := Err1WasTouched
 620                         if inodePrev == nil {
 621                                 fd.Close()
 622                                 runErr.Err = errTouched
 623                                 errs <- runErr
 624                                 return
 625                         }
 626                         inode, err := inodeFromFile(fd)
 627                         fd.Close()
 628                         if err != nil {
 629                                 runErr.Err = err
 630                                 errs <- runErr
 631                                 return
 632                         }
 633                         if !inode.Equals(inodePrev) {
 634                                 runErr.Err = errTouched
 635                                 errs <- runErr
 636                                 return
 637                         }
 638                 }
 639
 640                 if inodePrev != nil {
 641                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 642                                 inode, err := inodeFromFile(fd)
 643                                 fd.Close()
 644                                 if err == nil && !inode.Equals(inodePrev) {
 645                                         runErr.Err = Err1WasTouched
 646                                         errs <- runErr
 647                                         return
 648                                 }
 649                         }
 650                 }
 651
 652                 // Does it produce both stdout and tmp?
 653                 fiStdout, err := os.Stat(fdStdout.Name())
 654                 if err != nil {
 655                         runErr.Err = err
 656                         errs <- runErr
 657                         return
 658                 }
 659                 tmpExists := false
 660                 _, err = os.Stat(tmpPath)
 661                 if err == nil {
 662                         if fiStdout.Size() > 0 {
 663                                 runErr.Err = errors.New("created both tmp and stdout")
 664                                 errs <- runErr
 665                                 return
 666                         }
 667                         tmpExists = true
 668                 } else if !os.IsNotExist(err) {
 669                         runErr.Err = err
 670                         errs <- runErr
 671                         return
 672                 }
 673
 674                 // Determine what file we must process at last
 675                 var fd *os.File
 676                 if tmpExists {
 677                         fd, err = os.Open(tmpPath)
 678                         if err != nil {
 679                                 goto Finish
 680                         }
 681                         defer fd.Close()
 682                 } else if fiStdout.Size() > 0 {
 683                         fd = fdStdout
 684                 }
 685
 686                 // Do we need to ifcreate it, or ifchange with renaming?
 687                 if fd == nil {
 688                         os.Remove(path.Join(cwdOrig, tgt))
 689                         err = ifcreate(fdDep, tgt)
 690                         if err != nil {
 691                                 goto Finish
 692                         }
 693                 } else {
 694                         if !NoSync {
 695                                 err = fd.Sync()
 696                                 if err != nil {
 697                                         goto Finish
 698                                 }
 699                         }
 700                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 701                         if err != nil {
 702                                 goto Finish
 703                         }
 704                         if !NoSync {
 705                                 err = syncDir(cwdOrig)
 706                                 if err != nil {
 707                                         goto Finish
 708                                 }
 709                         }
 710                         err = depWrite(fdDep, cwdOrig, tgt)
 711                         if err != nil {
 712                                 goto Finish
 713                         }
 714                 }
 715
 716                 // Commit .rec
 717                 if !NoSync {
 718                         err = fdDep.Sync()
 719                         if err != nil {
 720                                 goto Finish
 721                         }
 722                 }
 723                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 724                 err = os.Rename(fdDep.Name(), fdDepPath)
 725                 if err != nil {
 726                         goto Finish
 727                 }
 728                 if !NoSync {
 729                         err = syncDir(redoDir)
 730                         if err != nil {
 731                                 goto Finish
 732                         }
 733                 }
 734         Finish:
 735                 runErr.Err = err
 736                 errs <- runErr
 737         }()
 738         return nil
 739 }
 740
 741 func isOkRun(err error) bool {
 742         if err == nil {
 743                 return true
 744         }
 745         var runErr RunError
 746         if errors.As(err, &runErr) && runErr.Err == nil {
 747                 tracef(CRedo, "%s", runErr.Name())
 748                 return true
 749         }
 750         tracef(CErr, "%s", err)
 751         return false
 752 }