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