run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2023 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         "bytes"
  25         "crypto/rand"
  26         "encoding/hex"
  27         "errors"
  28         "flag"
  29         "fmt"
  30         "io"
  31         "io/fs"
  32         "log"
  33         "os"
  34         "os/exec"
  35         "path"
  36         "strconv"
  37         "strings"
  38         "sync"
  39         "syscall"
  40         "time"
  41
  42         "go.cypherpunks.ru/recfile"
  43         "go.cypherpunks.ru/tai64n/v2"
  44         "golang.org/x/sys/unix"
  45 )
  46
  47 const (
  48         EnvDepFd        = "REDO_DEP_FD"
  49         EnvDirPrefix    = "REDO_DIRPREFIX"
  50         EnvDepCwd       = "REDO_DEP_CWD"
  51         EnvBuildUUID    = "REDO_BUILD_UUID"
  52         EnvStderrPrefix = "REDO_STDERR_PREFIX"
  53         EnvTrace        = "REDO_TRACE"
  54         EnvStderrKeep   = "REDO_LOGS"
  55         EnvStderrSilent = "REDO_SILENT"
  56         EnvNoSync       = "REDO_NO_SYNC"
  57         EnvStopIfMod    = "REDO_STOP_IF_MODIFIED"
  58
  59         RedoDir      = ".redo"
  60         LockSuffix   = ".lock"
  61         DepSuffix    = ".rec"
  62         TmpPrefix    = ".redo."
  63         LogSuffix    = ".log"
  64         LogRecSuffix = ".log-rec"
  65 )
  66
  67 var (
  68         NoSync       = false
  69         StderrKeep   = false
  70         StderrSilent = false
  71         StderrPrefix string
  72         StopIfMod    = false
  73         Jobs         sync.WaitGroup
  74
  75         flagTrace          *bool
  76         flagTraceAll       *bool
  77         flagStderrKeep     *bool
  78         flagStderrSilent   *bool
  79         flagForcedIfchange *bool
  80
  81         TracedAll bool
  82
  83         RunningProcs  = map[int]*os.Process{}
  84         RunningProcsM sync.Mutex
  85
  86         Err1WasTouched = errors.New("$1 was explicitly touched")
  87 )
  88
  89 func init() {
  90         cmdName := CmdName()
  91         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  92                 return
  93         }
  94         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  95         flagTraceAll = flag.Bool("xx", false,
  96                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  97         flagStderrKeep = flag.Bool("k", false,
  98                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  99         flagStderrSilent = flag.Bool("s", false,
 100                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
 101         flagForcedIfchange = flag.Bool("f", false, "forced redo-ifchange")
 102 }
 103
 104 type RunError struct {
 105         Tgt      string
 106         DoFile   string
 107         Started  *time.Time
 108         Finished *time.Time
 109         Err      error
 110 }
 111
 112 func (e *RunError) Name() string {
 113         var name string
 114         if e.DoFile == "" {
 115                 name = e.Tgt
 116         } else {
 117                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 118         }
 119         if e.Finished == nil {
 120                 return name
 121         }
 122         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 123 }
 124
 125 func (e RunError) Error() string {
 126         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 127 }
 128
 129 func mkdirs(pth string) error {
 130         if FileExists(pth) {
 131                 return nil
 132         }
 133         return os.MkdirAll(pth, os.FileMode(0777))
 134 }
 135
 136 func isModified(depInfo *DepInfo, cwd, tgt string) (
 137         modified bool, ourInode *Inode, hshPrev []byte, err error,
 138 ) {
 139         if depInfo == nil {
 140                 return
 141         }
 142         for _, dep := range depInfo.ifchanges {
 143                 if dep.tgt != tgt {
 144                         continue
 145                 }
 146                 ourInode, err = inodeFromFileByPath(path.Join(cwd, tgt))
 147                 if err != nil {
 148                         if os.IsNotExist(err) {
 149                                 err = nil
 150                                 return
 151                         }
 152                         err = ErrLine(err)
 153                         return
 154                 }
 155                 hshPrev = dep.hash
 156                 modified = !ourInode.Equals(dep.inode)
 157                 break
 158         }
 159         return
 160 }
 161
 162 func syncDir(dir string) error {
 163         fd, err := os.Open(dir)
 164         if err != nil {
 165                 return err
 166         }
 167         err = fd.Sync()
 168         fd.Close()
 169         return err
 170 }
 171
 172 func runScript(tgtOrig string, errs chan error, forced, traced bool) error {
 173         cwd, tgt := cwdAndTgt(tgtOrig)
 174         redoDir := path.Join(cwd, RedoDir)
 175         if err := mkdirs(redoDir); err != nil {
 176                 return TgtError{tgtOrig, ErrLine(err)}
 177         }
 178
 179         shCtx := fmt.Sprintf("sh: %s: cwd:%s", tgtOrig, cwd)
 180         jsToken := jsAcquire(shCtx)
 181         jsNeedsRelease := true
 182         defer func() {
 183                 if jsNeedsRelease {
 184                         jsRelease(shCtx, jsToken)
 185                 }
 186         }()
 187
 188         // Acquire lock
 189         fdLock, err := os.OpenFile(
 190                 path.Join(redoDir, tgt+LockSuffix),
 191                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 192                 os.FileMode(0666),
 193         )
 194         if err != nil {
 195                 return TgtError{tgtOrig, ErrLine(err)}
 196         }
 197         flock := unix.Flock_t{
 198                 Type:   unix.F_WRLCK,
 199                 Whence: io.SeekStart,
 200         }
 201         lockRelease := func() {
 202                 tracef(CLock, "LOCK_UN: %s", fdLock.Name())
 203                 flock.Type = unix.F_UNLCK
 204                 if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 205                         log.Fatalln(err, fdLock.Name())
 206                 }
 207                 fdLock.Close()
 208         }
 209         tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 210
 211         // Waiting for job completion, already taken by someone else
 212         if err = unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 213                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EAGAIN) {
 214                         fdLock.Close()
 215                         return TgtError{tgtOrig, ErrLine(err)}
 216                 }
 217                 Jobs.Add(1)
 218                 if err = unix.FcntlFlock(fdLock.Fd(), unix.F_GETLK, &flock); err != nil {
 219                         log.Fatalln(err, fdLock.Name())
 220                 }
 221                 tracef(CDebug, "waiting: %s (pid=%d)", tgtOrig, flock.Pid)
 222                 if FdStatus != nil {
 223                         if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
 224                                 log.Fatal(err)
 225                         }
 226                 }
 227                 go func() {
 228                         defer Jobs.Done()
 229                         tracef(CLock, "LOCK_EX: %s", fdLock.Name())
 230                 LockAgain:
 231                         if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
 232                                 if errors.Is(err, unix.EDEADLK) {
 233                                         time.Sleep(10 * time.Millisecond)
 234                                         goto LockAgain
 235                                 }
 236                                 log.Fatalln(err, fdLock.Name())
 237                         }
 238                         lockRelease()
 239                         tracef(CDebug, "waiting done: %s", tgtOrig)
 240                         if FdStatus != nil {
 241                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 242                                         log.Fatal(err)
 243                                 }
 244                         }
 245                         build, err := depReadBuild(path.Join(redoDir, tgt+DepSuffix))
 246                         if err != nil {
 247                                 if errors.Is(err, fs.ErrNotExist) {
 248                                         err = errors.New("was not built: no .rec")
 249                                 }
 250                                 goto Finish
 251                         }
 252                         if build != BuildUUID {
 253                                 err = errors.New("was not built: build differs")
 254                         }
 255                 Finish:
 256                         if err != nil {
 257                                 err = TgtError{tgtOrig, err}
 258                                 fdLock.Close()
 259                         }
 260                         errs <- err
 261                 }()
 262                 return nil
 263         }
 264
 265         depInfo, err := depRead(path.Join(redoDir, tgt+DepSuffix))
 266         if err != nil {
 267                 if errors.Is(err, fs.ErrNotExist) {
 268                         err = nil
 269                 } else {
 270                         lockRelease()
 271                         return TgtError{tgtOrig, err}
 272                 }
 273         }
 274
 275         // Check if it was already built in parallel
 276         if !forced && depInfo != nil && depInfo.build == BuildUUID {
 277                 lockRelease()
 278                 errs <- nil
 279                 return nil
 280         }
 281
 282         // Check if target is not modified externally
 283         modified, inodePrev, hshPrev, err := isModified(depInfo, cwd, tgt)
 284         if err != nil {
 285                 lockRelease()
 286                 return TgtError{tgtOrig, err}
 287         }
 288         if modified {
 289                 lockRelease()
 290                 if StopIfMod {
 291                         return fmt.Errorf("%s externally modified", tgtOrig)
 292                 }
 293                 tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 294                 go func() {
 295                         errs <- nil
 296                 }()
 297                 return nil
 298         }
 299         depInfo = nil
 300
 301         // Start preparing .rec
 302         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 303         if err != nil {
 304                 lockRelease()
 305                 return TgtError{tgtOrig, ErrLine(err)}
 306         }
 307         fdDepPath := fdDep.Name()
 308         cleanup := func() {
 309                 lockRelease()
 310                 fdDep.Close()
 311                 os.Remove(fdDep.Name())
 312         }
 313         if _, err = recfile.NewWriter(fdDep).WriteFields(
 314                 recfile.Field{Name: "Build", Value: BuildUUID},
 315         ); err != nil {
 316                 cleanup()
 317                 return TgtError{tgtOrig, ErrLine(err)}
 318         }
 319
 320         // Find .do
 321         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 322         if err != nil {
 323                 cleanup()
 324                 return TgtError{tgtOrig, ErrLine(err)}
 325         }
 326         if doFile == "" {
 327                 cleanup()
 328                 return TgtError{tgtOrig, errors.New("no .do found")}
 329         }
 330
 331         // Determine basename and DIRPREFIX
 332         doFileRelPath := doFile
 333         ents := strings.Split(cwd, "/")
 334         ents = ents[len(ents)-upLevels:]
 335         dirPrefix := path.Join(ents...)
 336         cwdOrig := cwd
 337         for i := 0; i < upLevels; i++ {
 338                 cwd = path.Join(cwd, "..")
 339                 doFileRelPath = path.Join("..", doFileRelPath)
 340         }
 341         cwd = path.Clean(cwd)
 342         doFilePath := path.Join(cwd, doFile)
 343         basename := tgt
 344         runErr := RunError{Tgt: tgtOrig}
 345         if strings.HasPrefix(doFile, "default.") {
 346                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 347                 runErr.DoFile = doFileRelPath
 348         }
 349
 350         if err = depWrite(fdDep, cwdOrig, doFileRelPath, nil); err != nil {
 351                 cleanup()
 352                 return TgtError{tgtOrig, ErrLine(err)}
 353         }
 354         fdDep.Close()
 355         tracef(CWait, "%s", runErr.Name())
 356
 357         // Prepare command line
 358         var cmdName string
 359         var args []string
 360         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 361                 cmdName = doFilePath
 362                 args = make([]string, 0, 3)
 363         } else {
 364                 cmdName = "/bin/sh"
 365                 if traced || TracedAll {
 366                         args = append(args, "-ex")
 367                 } else {
 368                         args = append(args, "-e")
 369                 }
 370                 args = append(args, doFile)
 371         }
 372
 373         // Temporary file for stdout
 374         fdStdout, err := tempfile(cwdOrig, tgt)
 375         if err != nil {
 376                 cleanup()
 377                 return TgtError{tgtOrig, ErrLine(err)}
 378         }
 379         stdoutPath := fdStdout.Name()
 380         fdStdout.Close()
 381         tmpPath := stdoutPath + ".3" // and for $3
 382         tmpPathRel := mustRel(cwd, tmpPath)
 383         args = append(
 384                 args,
 385                 path.Join(dirPrefix, tgt),
 386                 path.Join(dirPrefix, basename),
 387                 tmpPathRel,
 388         )
 389         shCtx = fmt.Sprintf(
 390                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 391                 tgtOrig, cmdName, args, cwd, dirPrefix,
 392         )
 393
 394         cmd := exec.Command(cmdName, args...)
 395         cmd.Dir = cwd
 396         // cmd.Stdin reads from /dev/null by default
 397         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 398         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 399         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 400
 401         childStderrPrefixRaw := make([]byte, 8)
 402         if _, err = io.ReadFull(rand.Reader, childStderrPrefixRaw); err != nil {
 403                 panic(err)
 404         }
 405         childStderrPrefix := hex.EncodeToString(childStderrPrefixRaw)
 406         cmd.Env = append(cmd.Env, fmt.Sprintf(
 407                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 408         ))
 409
 410         fdNum := 0
 411         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 412         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 413         fdNum++
 414         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 415         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 416         fdNum++
 417
 418         if FdStatus == nil {
 419                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 420         } else {
 421                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 422                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 423                 fdNum++
 424         }
 425
 426         // Preparing stderr
 427         var fdStderr *os.File
 428         if StderrKeep {
 429                 fdStderr, err = os.OpenFile(
 430                         path.Join(redoDir, tgt+LogSuffix),
 431                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 432                         os.FileMode(0666),
 433                 )
 434                 if err != nil {
 435                         cleanup()
 436                         return TgtError{tgtOrig, ErrLine(err)}
 437                 }
 438         }
 439         tracef(CDebug, "%s", shCtx)
 440
 441         jsNeedsRelease = false
 442         Jobs.Add(1)
 443         go func() {
 444                 if JSR == nil {
 445                         // infinite jobs
 446                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 447                 } else {
 448                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 449                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 450                         makeFlags := fmt.Sprintf(
 451                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 452                         )
 453                         makeFlags = strings.Trim(makeFlags, " ")
 454                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 455                         fdNum += 2
 456                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 457                 }
 458
 459                 if FdStatus != nil {
 460                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 461                                 log.Fatal(err)
 462                         }
 463                 }
 464
 465                 defer jsRelease(shCtx, jsToken)
 466
 467                 var finished time.Time
 468                 var exitErr *exec.ExitError
 469                 started := time.Now()
 470                 runErr.Started = &started
 471                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 472                 if err != nil {
 473                         if fdStderr != nil {
 474                                 fdStderr.Close()
 475                         }
 476                         runErr.Err = err
 477                         errs <- runErr
 478                         return
 479                 }
 480                 cmd.Stdout = fdStdout
 481                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 482                 if err != nil {
 483                         if fdStderr != nil {
 484                                 fdStderr.Close()
 485                         }
 486                         fdStdout.Close()
 487                         runErr.Err = err
 488                         errs <- runErr
 489                         return
 490                 }
 491                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 492                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 493                 fdNum++
 494                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 495
 496                 defer func() {
 497                         fdDep.Close()
 498                         fdStdout.Close()
 499                         if fdStderr != nil {
 500                                 fdStderr.Close()
 501                                 logRecPath := path.Join(redoDir, tgt+LogRecSuffix)
 502                                 if fdStderr, err = os.OpenFile(
 503                                         logRecPath,
 504                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 505                                         os.FileMode(0666),
 506                                 ); err == nil {
 507                                         fields := []recfile.Field{
 508                                                 {Name: "Build", Value: BuildUUID},
 509                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 510                                                 {Name: "Cwd", Value: cwd},
 511                                         }
 512                                         if cmd.Process != nil {
 513                                                 fields = append(fields, recfile.Field{
 514                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 515                                                 })
 516                                         }
 517                                         ts := new(tai64n.TAI64N)
 518                                         ts.FromTime(started)
 519                                         fields = append(fields,
 520                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 521                                         )
 522                                         ts.FromTime(finished)
 523                                         fields = append(fields,
 524                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 525                                         fields = append(fields, recfile.Field{
 526                                                 Name:  "Duration",
 527                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 528                                         })
 529                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 530                                         for _, arg := range args {
 531                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 532                                         }
 533                                         for _, env := range cmd.Env {
 534                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 535                                         }
 536                                         if exitErr != nil {
 537                                                 fields = append(fields, recfile.Field{
 538                                                         Name:  "ExitCode",
 539                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 540                                                 })
 541                                         }
 542                                         w := bufio.NewWriter(fdStderr)
 543
 544                                         depInfo, err := depRead(fdDepPath)
 545                                         if err != nil {
 546                                                 err = ErrLine(err)
 547                                                 goto Err
 548                                         }
 549                                         for _, dep := range depInfo.ifchanges {
 550                                                 fields = append(fields, recfile.Field{
 551                                                         Name:  "Ifchange",
 552                                                         Value: dep.tgt,
 553                                                 })
 554                                         }
 555                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 556                                         if err != nil {
 557                                                 err = ErrLine(err)
 558                                                 goto Err
 559                                         }
 560                                         err = ErrLine(w.Flush())
 561                                 Err:
 562                                         if err != nil {
 563                                                 log.Print(err)
 564                                                 os.Remove(logRecPath)
 565                                         }
 566                                         fdStderr.Close()
 567                                 } else {
 568                                         log.Println("can not open", logRecPath, ":", err)
 569                                 }
 570                         }
 571                         lockRelease()
 572                         os.Remove(fdDep.Name())
 573                         os.Remove(fdStdout.Name())
 574                         os.Remove(tmpPath)
 575                         if FdStatus != nil {
 576                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 577                                         log.Fatal(err)
 578                                 }
 579                         }
 580                         Jobs.Done()
 581                 }()
 582                 stderr, err := cmd.StderrPipe()
 583                 if err != nil {
 584                         runErr.Err = err
 585                         errs <- runErr
 586                         return
 587                 }
 588                 started = time.Now()
 589                 err = cmd.Start()
 590                 if err != nil {
 591                         runErr.Err = err
 592                         errs <- runErr
 593                         return
 594                 }
 595                 RunningProcsM.Lock()
 596                 RunningProcs[cmd.Process.Pid] = cmd.Process
 597                 RunningProcsM.Unlock()
 598                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 599                 tracef(CDebug, "%s runs %s", tgtOrig, pid)
 600
 601                 stderrTerm := make(chan struct{})
 602                 go func() {
 603                         scanner := bufio.NewScanner(stderr)
 604                         var line string
 605                         ts := new(tai64n.TAI64N)
 606                         for scanner.Scan() {
 607                                 line = scanner.Text()
 608                                 if strings.HasPrefix(line, childStderrPrefix) {
 609                                         line = line[len(childStderrPrefix):]
 610                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 611                                         continue
 612                                 }
 613                                 if fdStderr != nil {
 614                                         ts.FromTime(time.Now())
 615                                         LogMutex.Lock()
 616                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 617                                         LogMutex.Unlock()
 618                                 }
 619                                 if StderrSilent {
 620                                         continue
 621                                 }
 622                                 if MyPid == 0 {
 623                                         tracef(CNone, "%s", line)
 624                                 } else {
 625                                         tracef(CNone, "%s %s", pid, line)
 626                                 }
 627                         }
 628                         close(stderrTerm)
 629                 }()
 630
 631                 // Wait for job completion
 632                 <-stderrTerm
 633                 err = cmd.Wait()
 634                 RunningProcsM.Lock()
 635                 delete(RunningProcs, cmd.Process.Pid)
 636                 RunningProcsM.Unlock()
 637                 finished = time.Now()
 638                 runErr.Finished = &finished
 639                 if err != nil {
 640                         exitErr = err.(*exec.ExitError)
 641                         runErr.Err = err
 642                         errs <- runErr
 643                         return
 644                 }
 645
 646                 // Was $1 touched?
 647                 if inode, err := inodeFromFileByPath(path.Join(cwdOrig, tgt)); err == nil {
 648                         if inodePrev == nil {
 649                                 runErr.Err = Err1WasTouched
 650                                 errs <- runErr
 651                                 return
 652                         }
 653                         if err != nil {
 654                                 runErr.Err = err
 655                                 errs <- runErr
 656                                 return
 657                         }
 658                         if !inode.Equals(inodePrev) {
 659                                 runErr.Err = Err1WasTouched
 660                                 errs <- runErr
 661                                 return
 662                         }
 663                 }
 664
 665                 if inodePrev != nil {
 666                         if inode, err := inodeFromFileByPath(path.Join(cwdOrig, tgt)); err == nil {
 667                                 if !inode.Equals(inodePrev) {
 668                                         runErr.Err = Err1WasTouched
 669                                         errs <- runErr
 670                                         return
 671                                 }
 672                         }
 673                 }
 674
 675                 // Does it produce both stdout and tmp?
 676                 fiStdout, err := os.Stat(fdStdout.Name())
 677                 if err != nil {
 678                         runErr.Err = ErrLine(err)
 679                         errs <- runErr
 680                         return
 681                 }
 682                 tmpExists := false
 683                 _, err = os.Stat(tmpPath)
 684                 if err == nil {
 685                         if fiStdout.Size() > 0 {
 686                                 runErr.Err = errors.New("created both tmp and stdout")
 687                                 errs <- runErr
 688                                 return
 689                         }
 690                         tmpExists = true
 691                 } else if !errors.Is(err, fs.ErrNotExist) {
 692                         runErr.Err = ErrLine(err)
 693                         errs <- runErr
 694                         return
 695                 }
 696
 697                 // Determine what file we must process at last
 698                 var fd *os.File
 699                 if tmpExists {
 700                         fd, err = os.Open(tmpPath)
 701                         if err != nil {
 702                                 err = ErrLine(err)
 703                                 goto Finish
 704                         }
 705                         defer fd.Close()
 706                 } else if fiStdout.Size() > 0 {
 707                         fd = fdStdout
 708                 }
 709
 710                 // Do we need to ifcreate it, or ifchange with renaming?
 711                 if fd == nil {
 712                         os.Remove(path.Join(cwdOrig, tgt))
 713                         err = ifcreate(fdDep, tgt)
 714                         if err != nil {
 715                                 err = ErrLine(err)
 716                                 goto Finish
 717                         }
 718                 } else {
 719                         var hsh []byte
 720                         if hshPrev != nil {
 721                                 _, err = fd.Seek(0, io.SeekStart)
 722                                 if err != nil {
 723                                         err = ErrLine(err)
 724                                         goto Finish
 725                                 }
 726                                 hsh, err = fileHash(fd)
 727                                 if err != nil {
 728                                         err = ErrLine(err)
 729                                         goto Finish
 730                                 }
 731                                 if bytes.Equal(hsh, hshPrev) {
 732                                         tracef(CDebug, "%s has same hash, not renaming", tgtOrig)
 733                                         err = ErrLine(os.Remove(fd.Name()))
 734                                         if err != nil {
 735                                                 goto Finish
 736                                         }
 737                                         err = ErrLine(os.Chtimes(path.Join(cwdOrig, tgt), finished, finished))
 738                                         if err != nil {
 739                                                 goto Finish
 740                                         }
 741                                         if !NoSync {
 742                                                 err = ErrLine(syncDir(cwdOrig))
 743                                                 if err != nil {
 744                                                         goto Finish
 745                                                 }
 746                                         }
 747                                         err = ErrLine(depWrite(fdDep, cwdOrig, tgt, hsh))
 748                                         if err != nil {
 749                                                 goto Finish
 750                                         }
 751                                         goto RecCommit
 752                                 }
 753                         }
 754                         if !NoSync {
 755                                 err = ErrLine(fd.Sync())
 756                                 if err != nil {
 757                                         goto Finish
 758                                 }
 759                         }
 760                         err = ErrLine(os.Rename(fd.Name(), path.Join(cwdOrig, tgt)))
 761                         if err != nil {
 762                                 goto Finish
 763                         }
 764                         if !NoSync {
 765                                 err = ErrLine(syncDir(cwdOrig))
 766                                 if err != nil {
 767                                         goto Finish
 768                                 }
 769                         }
 770                         err = ErrLine(depWrite(fdDep, cwdOrig, tgt, hsh))
 771                         if err != nil {
 772                                 goto Finish
 773                         }
 774                 }
 775
 776         RecCommit:
 777                 // Commit .rec
 778                 if !NoSync {
 779                         err = ErrLine(fdDep.Sync())
 780                         if err != nil {
 781                                 goto Finish
 782                         }
 783                 }
 784                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 785                 err = ErrLine(os.Rename(fdDep.Name(), fdDepPath))
 786                 if err != nil {
 787                         goto Finish
 788                 }
 789                 if !NoSync {
 790                         err = ErrLine(syncDir(redoDir))
 791                         if err != nil {
 792                                 goto Finish
 793                         }
 794                 }
 795                 fdDep.Close()
 796
 797                 // Post-commit .rec sanitizing
 798                 if depInfo, err := depRead(fdDepPath); err == nil {
 799                         ifchangeSeen := make(map[string]struct{}, len(depInfo.ifchanges))
 800                         for _, dep := range depInfo.ifchanges {
 801                                 ifchangeSeen[dep.tgt] = struct{}{}
 802                         }
 803                         for _, dep := range depInfo.ifcreates {
 804                                 if _, exists := ifchangeSeen[dep]; exists {
 805                                         tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
 806                                 }
 807                         }
 808                 } else if errors.Is(err, fs.ErrNotExist) {
 809                         err = nil
 810                 } else {
 811                         err = ErrLine(err)
 812                         goto Finish
 813                 }
 814
 815         Finish:
 816                 runErr.Err = err
 817                 errs <- runErr
 818         }()
 819         return nil
 820 }
 821
 822 func isOkRun(err error) bool {
 823         if err == nil {
 824                 return true
 825         }
 826         var runErr RunError
 827         if errors.As(err, &runErr) && runErr.Err == nil {
 828                 tracef(CRedo, "%s", runErr.Name())
 829                 return true
 830         }
 831         tracef(CErr, "%s", err)
 832         return false
 833 }