run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2022 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         EnvStopIfMod    = "REDO_STOP_IF_MODIFIED"
  55
  56         RedoDir      = ".redo"
  57         LockSuffix   = ".lock"
  58         DepSuffix    = ".rec"
  59         TmpPrefix    = ".redo."
  60         LogSuffix    = ".log"
  61         LogRecSuffix = ".log-rec"
  62 )
  63
  64 var (
  65         NoSync       = false
  66         StderrKeep   = false
  67         StderrSilent = false
  68         StderrPrefix string
  69         StopIfMod    = false
  70         Jobs         sync.WaitGroup
  71
  72         flagTrace          *bool
  73         flagTraceAll       *bool
  74         flagStderrKeep     *bool
  75         flagStderrSilent   *bool
  76         flagForcedIfchange *bool
  77
  78         TracedAll bool
  79
  80         RunningProcs  = map[int]*os.Process{}
  81         RunningProcsM sync.Mutex
  82
  83         Err1WasTouched = errors.New("$1 was explicitly touched")
  84 )
  85
  86 func init() {
  87         cmdName := CmdName()
  88         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  89                 return
  90         }
  91         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  92         flagTraceAll = flag.Bool("xx", false,
  93                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  94         flagStderrKeep = flag.Bool("k", false,
  95                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  96         flagStderrSilent = flag.Bool("s", false,
  97                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
  98         flagForcedIfchange = flag.Bool("f", false, "forced redo-ifchange")
  99 }
 100
 101 type RunError struct {
 102         Tgt      string
 103         DoFile   string
 104         Started  *time.Time
 105         Finished *time.Time
 106         Err      error
 107 }
 108
 109 func (e *RunError) Name() string {
 110         var name string
 111         if e.DoFile == "" {
 112                 name = e.Tgt
 113         } else {
 114                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 115         }
 116         if e.Finished == nil {
 117                 return name
 118         }
 119         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 120 }
 121
 122 func (e RunError) Error() string {
 123         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 124 }
 125
 126 func mkdirs(pth string) error {
 127         if _, err := os.Stat(pth); err == nil {
 128                 return nil
 129         }
 130         return os.MkdirAll(pth, os.FileMode(0777))
 131 }
 132
 133 func isModified(cwd, redoDir, tgt string) (bool, *Inode, string, error) {
 134         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 135         if err != nil {
 136                 if os.IsNotExist(err) {
 137                         return false, nil, "", nil
 138                 }
 139                 return false, nil, "", err
 140         }
 141         defer fdDep.Close()
 142         r := recfile.NewReader(fdDep)
 143         var modified bool
 144         var ourInode *Inode
 145         var hshPrev string
 146         for {
 147                 m, err := r.NextMap()
 148                 if err != nil {
 149                         if errors.Is(err, io.EOF) {
 150                                 break
 151                         }
 152                         return false, nil, "", err
 153                 }
 154                 if m["Type"] != DepTypeIfchange || m["Target"] != tgt {
 155                         continue
 156                 }
 157                 fd, err := os.Open(path.Join(cwd, tgt))
 158                 if err != nil {
 159                         if os.IsNotExist(err) {
 160                                 return false, nil, "", nil
 161                         }
 162                         return false, nil, "", err
 163                 }
 164                 ourInode, err = inodeFromFile(fd)
 165                 fd.Close()
 166                 if err != nil {
 167                         return false, nil, "", err
 168                 }
 169                 theirInode, err := inodeFromRec(m)
 170                 if err != nil {
 171                         return false, nil, "", err
 172                 }
 173                 hshPrev = m["Hash"]
 174                 modified = !ourInode.Equals(theirInode)
 175                 break
 176         }
 177         return modified, ourInode, hshPrev, nil
 178 }
 179
 180 func syncDir(dir string) error {
 181         fd, err := os.Open(dir)
 182         if err != nil {
 183                 return err
 184         }
 185         err = fd.Sync()
 186         fd.Close()
 187         return err
 188 }
 189
 190 func runScript(tgtOrig string, errs chan error, traced bool) error {
 191         cwd, tgt := cwdAndTgt(tgtOrig)
 192         redoDir := path.Join(cwd, RedoDir)
 193         if err := mkdirs(redoDir); err != nil {
 194                 return TgtError{tgtOrig, err}
 195         }
 196
 197         // Acquire lock
 198         fdLock, err := os.OpenFile(
 199                 path.Join(redoDir, tgt+LockSuffix),
 200                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 201                 os.FileMode(0666),
 202         )
 203         if err != nil {
 204                 return TgtError{tgtOrig, err}
 205         }
 206         flock := unix.Flock_t{
 207                 Type:   unix.F_WRLCK,
 208                 Whence: io.SeekStart,
 209         }
 210         lockRelease := func() {
 211                 tracef(CLock, "LOCK_UN: %s", fdLock.Name())
 212                 flock.Type = unix.F_UNLCK
 213                 if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 214                         log.Fatalln(err)
 215                 }
 216                 fdLock.Close()
 217         }
 218         tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 219
 220         // Waiting for job completion, already taken by someone else
 221         if err = unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 222                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EAGAIN) {
 223                         fdLock.Close()
 224                         return TgtError{tgtOrig, err}
 225                 }
 226                 Jobs.Add(1)
 227                 if err = unix.FcntlFlock(fdLock.Fd(), unix.F_GETLK, &flock); err != nil {
 228                         log.Fatalln(err)
 229                 }
 230                 tracef(CDebug, "waiting: %s (pid=%d)", tgtOrig, flock.Pid)
 231                 if FdStatus != nil {
 232                         if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
 233                                 log.Fatalln(err)
 234                         }
 235                 }
 236                 go func() {
 237                         defer Jobs.Done()
 238                         tracef(CLock, "LOCK_EX: %s", fdLock.Name())
 239                         if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
 240                                 log.Fatalln(err)
 241                         }
 242                         lockRelease()
 243                         tracef(CDebug, "waiting done: %s", tgtOrig)
 244                         if FdStatus != nil {
 245                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 246                                         log.Fatalln(err)
 247                                 }
 248                         }
 249                         var depInfo *DepInfo
 250                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 251                         if err != nil {
 252                                 if os.IsNotExist(err) {
 253                                         err = errors.New("was not built: no .rec")
 254                                 }
 255                                 goto Finish
 256                         }
 257                         defer fdDep.Close()
 258                         depInfo, err = depRead(fdDep)
 259                         if err != nil {
 260                                 goto Finish
 261                         }
 262                         if depInfo.build != BuildUUID {
 263                                 err = errors.New("was not built: build differs")
 264                         }
 265                 Finish:
 266                         if err != nil {
 267                                 err = TgtError{tgtOrig, err}
 268                         }
 269                         errs <- err
 270                 }()
 271                 return nil
 272         }
 273
 274         // Check if target is not modified externally
 275         modified, inodePrev, hshPrev, err := isModified(cwd, redoDir, tgt)
 276         if err != nil {
 277                 lockRelease()
 278                 return TgtError{tgtOrig, err}
 279         }
 280         if modified {
 281                 lockRelease()
 282                 if StopIfMod {
 283                         return fmt.Errorf("%s externally modified", tgtOrig)
 284                 }
 285                 tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 286                 go func() {
 287                         errs <- nil
 288                 }()
 289                 return nil
 290         }
 291
 292         // Start preparing .rec
 293         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 294         if err != nil {
 295                 lockRelease()
 296                 return TgtError{tgtOrig, err}
 297         }
 298         fdDepPath := fdDep.Name()
 299         cleanup := func() {
 300                 lockRelease()
 301                 fdDep.Close()
 302                 os.Remove(fdDep.Name())
 303         }
 304         if _, err = recfile.NewWriter(fdDep).WriteFields(
 305                 recfile.Field{Name: "Build", Value: BuildUUID},
 306         ); err != nil {
 307                 cleanup()
 308                 return TgtError{tgtOrig, err}
 309         }
 310
 311         // Find .do
 312         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 313         if err != nil {
 314                 cleanup()
 315                 return TgtError{tgtOrig, err}
 316         }
 317         if doFile == "" {
 318                 cleanup()
 319                 return TgtError{tgtOrig, errors.New("no .do found")}
 320         }
 321
 322         // Determine basename and DIRPREFIX
 323         doFileRelPath := doFile
 324         ents := strings.Split(cwd, "/")
 325         ents = ents[len(ents)-upLevels:]
 326         dirPrefix := path.Join(ents...)
 327         cwdOrig := cwd
 328         for i := 0; i < upLevels; i++ {
 329                 cwd = path.Join(cwd, "..")
 330                 doFileRelPath = path.Join("..", doFileRelPath)
 331         }
 332         cwd = path.Clean(cwd)
 333         doFilePath := path.Join(cwd, doFile)
 334         basename := tgt
 335         runErr := RunError{Tgt: tgtOrig}
 336         if strings.HasPrefix(doFile, "default.") {
 337                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 338                 runErr.DoFile = doFileRelPath
 339         }
 340
 341         if err = depWrite(fdDep, cwdOrig, doFileRelPath, ""); err != nil {
 342                 cleanup()
 343                 return TgtError{tgtOrig, err}
 344         }
 345         fdDep.Close()
 346         tracef(CWait, "%s", runErr.Name())
 347
 348         // Prepare command line
 349         var cmdName string
 350         var args []string
 351         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 352                 cmdName = doFilePath
 353                 args = make([]string, 0, 3)
 354         } else {
 355                 cmdName = "/bin/sh"
 356                 if traced || TracedAll {
 357                         args = append(args, "-ex")
 358                 } else {
 359                         args = append(args, "-e")
 360                 }
 361                 args = append(args, doFile)
 362         }
 363
 364         // Temporary file for stdout
 365         fdStdout, err := tempfile(cwdOrig, tgt)
 366         if err != nil {
 367                 cleanup()
 368                 return TgtError{tgtOrig, err}
 369         }
 370         stdoutPath := fdStdout.Name()
 371         fdStdout.Close()
 372         tmpPath := stdoutPath + ".3" // and for $3
 373         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 374         if err != nil {
 375                 panic(err)
 376         }
 377         args = append(
 378                 args,
 379                 path.Join(dirPrefix, tgt),
 380                 path.Join(dirPrefix, basename),
 381                 tmpPathRel,
 382         )
 383
 384         cmd := exec.Command(cmdName, args...)
 385         cmd.Dir = cwd
 386         // cmd.Stdin reads from /dev/null by default
 387         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 388         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 389         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 390
 391         childStderrPrefix := tempsuffix()
 392         cmd.Env = append(cmd.Env, fmt.Sprintf(
 393                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 394         ))
 395
 396         fdNum := 0
 397         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 398         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 399         fdNum++
 400         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 401         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 402         fdNum++
 403
 404         if FdStatus == nil {
 405                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 406         } else {
 407                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 408                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 409                 fdNum++
 410         }
 411
 412         // Preparing stderr
 413         var fdStderr *os.File
 414         if StderrKeep {
 415                 fdStderr, err = os.OpenFile(
 416                         path.Join(redoDir, tgt+LogSuffix),
 417                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 418                         os.FileMode(0666),
 419                 )
 420                 if err != nil {
 421                         cleanup()
 422                         return TgtError{tgtOrig, err}
 423                 }
 424         }
 425         shCtx := fmt.Sprintf(
 426                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 427                 tgtOrig, cmdName, args, cwd, dirPrefix,
 428         )
 429         tracef(CDebug, "%s", shCtx)
 430
 431         Jobs.Add(1)
 432         go func() {
 433                 jsToken := jsAcquire(shCtx)
 434                 if JSR == nil {
 435                         // infinite jobs
 436                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 437                 } else {
 438                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 439                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 440                         makeFlags := fmt.Sprintf(
 441                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 442                         )
 443                         makeFlags = strings.Trim(makeFlags, " ")
 444                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 445                         fdNum += 2
 446                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 447                 }
 448
 449                 if FdStatus != nil {
 450                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 451                                 log.Fatalln(err)
 452                         }
 453                 }
 454
 455                 var finished time.Time
 456                 var exitErr *exec.ExitError
 457                 started := time.Now()
 458                 runErr.Started = &started
 459                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 460                 if err != nil {
 461                         runErr.Err = err
 462                         errs <- runErr
 463                         return
 464                 }
 465                 cmd.Stdout = fdStdout
 466                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 467                 if err != nil {
 468                         runErr.Err = err
 469                         errs <- runErr
 470                         return
 471                 }
 472                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 473                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 474                 fdNum++
 475                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 476
 477                 defer func() {
 478                         jsRelease(shCtx, jsToken)
 479                         fdDep.Close()
 480                         fdStdout.Close()
 481                         if fdStderr != nil {
 482                                 fdStderr.Close()
 483                                 logRecPath := path.Join(redoDir, tgt+LogRecSuffix)
 484                                 if fdStderr, err = os.OpenFile(
 485                                         logRecPath,
 486                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 487                                         os.FileMode(0666),
 488                                 ); err == nil {
 489                                         fields := []recfile.Field{
 490                                                 {Name: "Build", Value: BuildUUID},
 491                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 492                                                 {Name: "Cwd", Value: cwd},
 493                                         }
 494                                         if cmd.Process != nil {
 495                                                 fields = append(fields, recfile.Field{
 496                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 497                                                 })
 498                                         }
 499                                         ts := new(tai64n.TAI64N)
 500                                         ts.FromTime(started)
 501                                         fields = append(fields,
 502                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 503                                         )
 504                                         ts.FromTime(finished)
 505                                         fields = append(fields,
 506                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 507                                         fields = append(fields, recfile.Field{
 508                                                 Name:  "Duration",
 509                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 510                                         })
 511                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 512                                         for _, arg := range args {
 513                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 514                                         }
 515                                         for _, env := range cmd.Env {
 516                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 517                                         }
 518                                         if exitErr != nil {
 519                                                 fields = append(fields, recfile.Field{
 520                                                         Name:  "ExitCode",
 521                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 522                                                 })
 523                                         }
 524                                         w := bufio.NewWriter(fdStderr)
 525
 526                                         var depInfo *DepInfo
 527                                         fdDep, err := os.Open(fdDepPath)
 528                                         if err != nil {
 529                                                 goto Err
 530                                         }
 531                                         depInfo, err = depRead(fdDep)
 532                                         fdDep.Close()
 533                                         if err != nil {
 534                                                 goto Err
 535                                         }
 536                                         for _, dep := range depInfo.ifchanges {
 537                                                 fields = append(fields, recfile.Field{
 538                                                         Name:  "Ifchange",
 539                                                         Value: dep["Target"],
 540                                                 })
 541                                         }
 542                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 543                                         if err != nil {
 544                                                 goto Err
 545                                         }
 546                                         err = w.Flush()
 547                                 Err:
 548                                         if err != nil {
 549                                                 log.Println(err)
 550                                                 os.Remove(logRecPath)
 551                                         }
 552                                         fdStderr.Close()
 553                                 } else {
 554                                         log.Println("can not open", logRecPath, ":", err)
 555                                 }
 556                         }
 557                         lockRelease()
 558                         os.Remove(fdDep.Name())
 559                         os.Remove(fdStdout.Name())
 560                         os.Remove(tmpPath)
 561                         os.Remove(fdLock.Name())
 562                         if FdStatus != nil {
 563                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 564                                         log.Fatalln(err)
 565                                 }
 566                         }
 567                         Jobs.Done()
 568                 }()
 569                 stderr, err := cmd.StderrPipe()
 570                 if err != nil {
 571                         runErr.Err = err
 572                         errs <- runErr
 573                         return
 574                 }
 575                 started = time.Now()
 576                 err = cmd.Start()
 577                 if err != nil {
 578                         runErr.Err = err
 579                         errs <- runErr
 580                         return
 581                 }
 582                 RunningProcsM.Lock()
 583                 RunningProcs[cmd.Process.Pid] = cmd.Process
 584                 RunningProcsM.Unlock()
 585                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 586                 tracef(CDebug, "%s runs %s", tgtOrig, pid)
 587
 588                 stderrTerm := make(chan struct{})
 589                 go func() {
 590                         scanner := bufio.NewScanner(stderr)
 591                         var line string
 592                         ts := new(tai64n.TAI64N)
 593                         for scanner.Scan() {
 594                                 line = scanner.Text()
 595                                 if strings.HasPrefix(line, childStderrPrefix) {
 596                                         line = line[len(childStderrPrefix):]
 597                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 598                                         continue
 599                                 }
 600                                 if fdStderr != nil {
 601                                         ts.FromTime(time.Now())
 602                                         LogMutex.Lock()
 603                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 604                                         LogMutex.Unlock()
 605                                 }
 606                                 if StderrSilent {
 607                                         continue
 608                                 }
 609                                 if MyPid == 0 {
 610                                         tracef(CNone, "%s", line)
 611                                 } else {
 612                                         tracef(CNone, "%s %s", pid, line)
 613                                 }
 614                         }
 615                         close(stderrTerm)
 616                 }()
 617
 618                 // Wait for job completion
 619                 <-stderrTerm
 620                 err = cmd.Wait()
 621                 RunningProcsM.Lock()
 622                 delete(RunningProcs, cmd.Process.Pid)
 623                 RunningProcsM.Unlock()
 624                 finished = time.Now()
 625                 runErr.Finished = &finished
 626                 if err != nil {
 627                         exitErr = err.(*exec.ExitError)
 628                         runErr.Err = err
 629                         errs <- runErr
 630                         return
 631                 }
 632
 633                 // Was $1 touched?
 634                 if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 635                         if inodePrev == nil {
 636                                 fd.Close()
 637                                 runErr.Err = Err1WasTouched
 638                                 errs <- runErr
 639                                 return
 640                         }
 641                         inode, err := inodeFromFile(fd)
 642                         fd.Close()
 643                         if err != nil {
 644                                 runErr.Err = err
 645                                 errs <- runErr
 646                                 return
 647                         }
 648                         if !inode.Equals(inodePrev) {
 649                                 runErr.Err = Err1WasTouched
 650                                 errs <- runErr
 651                                 return
 652                         }
 653                 }
 654
 655                 if inodePrev != nil {
 656                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 657                                 inode, err := inodeFromFile(fd)
 658                                 fd.Close()
 659                                 if err == nil && !inode.Equals(inodePrev) {
 660                                         runErr.Err = Err1WasTouched
 661                                         errs <- runErr
 662                                         return
 663                                 }
 664                         }
 665                 }
 666
 667                 // Does it produce both stdout and tmp?
 668                 fiStdout, err := os.Stat(fdStdout.Name())
 669                 if err != nil {
 670                         runErr.Err = err
 671                         errs <- runErr
 672                         return
 673                 }
 674                 tmpExists := false
 675                 _, err = os.Stat(tmpPath)
 676                 if err == nil {
 677                         if fiStdout.Size() > 0 {
 678                                 runErr.Err = errors.New("created both tmp and stdout")
 679                                 errs <- runErr
 680                                 return
 681                         }
 682                         tmpExists = true
 683                 } else if !os.IsNotExist(err) {
 684                         runErr.Err = err
 685                         errs <- runErr
 686                         return
 687                 }
 688
 689                 // Determine what file we must process at last
 690                 var fd *os.File
 691                 if tmpExists {
 692                         fd, err = os.Open(tmpPath)
 693                         if err != nil {
 694                                 goto Finish
 695                         }
 696                         defer fd.Close()
 697                 } else if fiStdout.Size() > 0 {
 698                         fd = fdStdout
 699                 }
 700
 701                 // Do we need to ifcreate it, or ifchange with renaming?
 702                 if fd == nil {
 703                         os.Remove(path.Join(cwdOrig, tgt))
 704                         err = ifcreate(fdDep, tgt)
 705                         if err != nil {
 706                                 goto Finish
 707                         }
 708                 } else {
 709                         var hsh string
 710                         if hshPrev != "" {
 711                                 _, err = fd.Seek(0, io.SeekStart)
 712                                 if err != nil {
 713                                         goto Finish
 714                                 }
 715                                 hsh, err = fileHash(fd)
 716                                 if err != nil {
 717                                         goto Finish
 718                                 }
 719                                 if hsh == hshPrev {
 720                                         tracef(CDebug, "%s has same hash, not renaming", tgtOrig)
 721                                         err = os.Remove(fd.Name())
 722                                         if err != nil {
 723                                                 goto Finish
 724                                         }
 725                                         err = os.Chtimes(path.Join(cwdOrig, tgt), finished, finished)
 726                                         if err != nil {
 727                                                 goto Finish
 728                                         }
 729                                         if !NoSync {
 730                                                 err = syncDir(cwdOrig)
 731                                                 if err != nil {
 732                                                         goto Finish
 733                                                 }
 734                                         }
 735                                         err = depWrite(fdDep, cwdOrig, tgt, hshPrev)
 736                                         if err != nil {
 737                                                 goto Finish
 738                                         }
 739                                         goto RecCommit
 740                                 }
 741                         }
 742                         if !NoSync {
 743                                 err = fd.Sync()
 744                                 if err != nil {
 745                                         goto Finish
 746                                 }
 747                         }
 748                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 749                         if err != nil {
 750                                 goto Finish
 751                         }
 752                         if !NoSync {
 753                                 err = syncDir(cwdOrig)
 754                                 if err != nil {
 755                                         goto Finish
 756                                 }
 757                         }
 758                         err = depWrite(fdDep, cwdOrig, tgt, hsh)
 759                         if err != nil {
 760                                 goto Finish
 761                         }
 762                 }
 763
 764         RecCommit:
 765                 // Commit .rec
 766                 if !NoSync {
 767                         err = fdDep.Sync()
 768                         if err != nil {
 769                                 goto Finish
 770                         }
 771                 }
 772                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 773                 err = os.Rename(fdDep.Name(), fdDepPath)
 774                 if err != nil {
 775                         goto Finish
 776                 }
 777                 if !NoSync {
 778                         err = syncDir(redoDir)
 779                         if err != nil {
 780                                 goto Finish
 781                         }
 782                 }
 783
 784                 // Post-commit .rec sanitizing
 785                 fdDep.Close()
 786                 if fdDepR, err := os.Open(fdDepPath); err == nil {
 787                         depInfo, err := depRead(fdDepR)
 788                         fdDepR.Close()
 789                         if err != nil {
 790                                 goto Finish
 791                         }
 792                         ifchangeSeen := make(map[string]struct{}, len(depInfo.ifchanges))
 793                         for _, dep := range depInfo.ifchanges {
 794                                 ifchangeSeen[dep["Target"]] = struct{}{}
 795                         }
 796                         for _, dep := range depInfo.ifcreates {
 797                                 if _, exists := ifchangeSeen[dep]; exists {
 798                                         tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
 799                                 }
 800                         }
 801                 }
 802
 803         Finish:
 804                 runErr.Err = err
 805                 errs <- runErr
 806         }()
 807         return nil
 808 }
 809
 810 func isOkRun(err error) bool {
 811         if err == nil {
 812                 return true
 813         }
 814         var runErr RunError
 815         if errors.As(err, &runErr) && runErr.Err == nil {
 816                 tracef(CRedo, "%s", runErr.Name())
 817                 return true
 818         }
 819         tracef(CErr, "%s", err)
 820         return false
 821 }