run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2024 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         "crypto/rand"
  25         "encoding/hex"
  26         "errors"
  27         "flag"
  28         "fmt"
  29         "io"
  30         "io/fs"
  31         "log"
  32         "os"
  33         "os/exec"
  34         "path"
  35         "strconv"
  36         "strings"
  37         "sync"
  38         "syscall"
  39         "time"
  40
  41         "go.cypherpunks.ru/recfile"
  42         "go.cypherpunks.ru/tai64n/v2"
  43         "golang.org/x/sys/unix"
  44 )
  45
  46 const (
  47         EnvDepFd        = "REDO_DEP_FD"
  48         EnvDirPrefix    = "REDO_DIRPREFIX"
  49         EnvDepCwd       = "REDO_DEP_CWD"
  50         EnvBuildUUID    = "REDO_BUILD_UUID"
  51         EnvStderrPrefix = "REDO_STDERR_PREFIX"
  52         EnvTrace        = "REDO_TRACE"
  53         EnvStderrKeep   = "REDO_LOGS"
  54         EnvStderrSilent = "REDO_SILENT"
  55         EnvNoSync       = "REDO_NO_SYNC"
  56         EnvStopIfMod    = "REDO_STOP_IF_MODIFIED"
  57
  58         RedoDir      = ".redo"
  59         LockSuffix   = ".lock"
  60         DepSuffix    = ".dep"
  61         TmpPrefix    = ".redo."
  62         LogSuffix    = ".log"
  63         LogRecSuffix = ".log-rec"
  64 )
  65
  66 var (
  67         NoSync       = false
  68         StderrKeep   = false
  69         StderrSilent = false
  70         StderrPrefix string
  71         StopIfMod    = false
  72         Jobs         sync.WaitGroup
  73
  74         flagTrace          *bool
  75         flagTraceAll       *bool
  76         flagStderrKeep     *bool
  77         flagStderrSilent   *bool
  78         flagForcedIfchange *bool
  79
  80         TracedAll bool
  81
  82         RunningProcs  = map[int]*os.Process{}
  83         RunningProcsM sync.Mutex
  84
  85         Err1WasTouched = errors.New("$1 was explicitly touched")
  86 )
  87
  88 func init() {
  89         cmdName := CmdName()
  90         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  91                 return
  92         }
  93         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  94         flagTraceAll = flag.Bool("xx", false,
  95                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  96         flagStderrKeep = flag.Bool("k", false,
  97                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  98         flagStderrSilent = flag.Bool("s", false,
  99                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
 100         flagForcedIfchange = flag.Bool("f", false, "forced redo-ifchange")
 101 }
 102
 103 type RunError struct {
 104         Tgt      *Tgt
 105         DoFile   string
 106         Started  *time.Time
 107         Finished *time.Time
 108         Err      error
 109 }
 110
 111 func (e *RunError) Name() string {
 112         var name string
 113         if e.DoFile == "" {
 114                 name = e.Tgt.rel
 115         } else {
 116                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 117         }
 118         if e.Finished == nil {
 119                 return name
 120         }
 121         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 122 }
 123
 124 func (e RunError) Error() string {
 125         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 126 }
 127
 128 func mkdirs(pth string) error {
 129         if FileExists(pth) {
 130                 return nil
 131         }
 132         return os.MkdirAll(pth, os.FileMode(0777))
 133 }
 134
 135 func isModified(dep *Dep, tgt *Tgt) (
 136         modified bool, ourInode *Inode, hshPrev Hash, err error,
 137 ) {
 138         if dep == nil {
 139                 return
 140         }
 141         for _, ifchange := range dep.ifchanges {
 142                 if ifchange.tgt.a != tgt.a {
 143                         continue
 144                 }
 145                 ourInode, err = inodeFromFileByPath(tgt.a)
 146                 if err != nil {
 147                         if os.IsNotExist(err) {
 148                                 err = nil
 149                                 return
 150                         }
 151                         err = ErrLine(err)
 152                         return
 153                 }
 154                 hshPrev = ifchange.Hash()
 155                 modified = !ourInode.Equals(ifchange.Inode())
 156                 break
 157         }
 158         return
 159 }
 160
 161 func syncDir(dir string) error {
 162         fd, err := os.Open(dir)
 163         if err != nil {
 164                 return err
 165         }
 166         err = fd.Sync()
 167         fd.Close()
 168         return err
 169 }
 170
 171 func runScript(tgt *Tgt, errs chan error, forced, traced bool) error {
 172         tgtH, tgtT := pathSplit(tgt.a)
 173         redoDir := path.Join(tgtH, RedoDir)
 174         if err := mkdirs(redoDir); err != nil {
 175                 return TgtError{tgt, ErrLine(err)}
 176         }
 177
 178         shCtx := fmt.Sprintf("sh: %s: cwd:%s", tgt, tgtH)
 179         jsToken := jsAcquire(shCtx)
 180         jsNeedsRelease := true
 181         defer func() {
 182                 if jsNeedsRelease {
 183                         jsRelease(shCtx, jsToken)
 184                 }
 185         }()
 186
 187         // Acquire lock
 188         fdLock, err := os.OpenFile(
 189                 path.Join(redoDir, tgtT+LockSuffix),
 190                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 191                 os.FileMode(0666),
 192         )
 193         if err != nil {
 194                 return TgtError{tgt, ErrLine(err)}
 195         }
 196         flock := unix.Flock_t{
 197                 Type:   unix.F_WRLCK,
 198                 Whence: io.SeekStart,
 199         }
 200         lockRelease := func() {
 201                 tracef(CLock, "LOCK_UN: %s", fdLock.Name())
 202                 flock.Type = unix.F_UNLCK
 203                 if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 204                         log.Fatalln(err, fdLock.Name())
 205                 }
 206                 fdLock.Close()
 207         }
 208         tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 209
 210         // Waiting for job completion, already taken by someone else
 211         if err = unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 212                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EAGAIN) {
 213                         fdLock.Close()
 214                         return TgtError{tgt, ErrLine(err)}
 215                 }
 216                 Jobs.Add(1)
 217                 if err = unix.FcntlFlock(fdLock.Fd(), unix.F_GETLK, &flock); err != nil {
 218                         log.Fatalln(err, fdLock.Name())
 219                 }
 220                 tracef(CDebug, "waiting: %s (pid=%d)", tgt, flock.Pid)
 221                 if FdStatus != nil {
 222                         if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
 223                                 log.Fatal(err)
 224                         }
 225                 }
 226                 go func() {
 227                         defer Jobs.Done()
 228                         tracef(CLock, "LOCK_EX: %s", fdLock.Name())
 229                 LockAgain:
 230                         if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
 231                                 if errors.Is(err, unix.EDEADLK) {
 232                                         time.Sleep(10 * time.Millisecond)
 233                                         goto LockAgain
 234                                 }
 235                                 log.Fatalln(err, fdLock.Name())
 236                         }
 237                         lockRelease()
 238                         tracef(CDebug, "waiting done: %s", tgt)
 239                         if FdStatus != nil {
 240                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 241                                         log.Fatal(err)
 242                                 }
 243                         }
 244                         build, err := depBuildRead(tgt.dep)
 245                         if err == nil {
 246                                 if build != BuildUUID {
 247                                         err = errors.New("was not built: build differs")
 248                                 }
 249                         } else {
 250                                 if errors.Is(err, fs.ErrNotExist) {
 251                                         err = errors.New("was not built: no .dep")
 252                                 }
 253                         }
 254                         if err != nil {
 255                                 err = TgtError{tgt, err}
 256                         }
 257                         errs <- err
 258                 }()
 259                 return nil
 260         }
 261
 262         // It scans the whole .dep file while searching for the single target,
 263         // but that one is always located at the very end
 264         dep, err := depRead(tgt)
 265         if err != nil {
 266                 if errors.Is(err, fs.ErrNotExist) {
 267                         err = nil
 268                 } else {
 269                         lockRelease()
 270                         return TgtError{tgt, ErrLine(err)}
 271                 }
 272         }
 273
 274         // Check if it was already built in parallel
 275         if !forced && dep != nil && dep.build == BuildUUID {
 276                 lockRelease()
 277                 errs <- nil
 278                 return nil
 279         }
 280
 281         // Check if target is not modified externally
 282         modified, inodePrev, hshPrev, err := isModified(dep, tgt)
 283         if err != nil {
 284                 lockRelease()
 285                 return TgtError{tgt, ErrLine(err)}
 286         }
 287         if modified {
 288                 lockRelease()
 289                 if StopIfMod {
 290                         return fmt.Errorf("%s externally modified", tgt)
 291                 }
 292                 Jobs.Add(1)
 293                 tracef(CWarn, "%s externally modified: not redoing", tgt)
 294                 go func() {
 295                         errs <- nil
 296                         Jobs.Done()
 297                 }()
 298                 return nil
 299         }
 300         dep = nil
 301
 302         // Start preparing .dep
 303         fdDep, err := tempfile(redoDir, tgtT+DepSuffix)
 304         if err != nil {
 305                 lockRelease()
 306                 return TgtError{tgt, ErrLine(err)}
 307         }
 308         fdDepOpened := true
 309         fdDepExists := true
 310         fdDepW := bufio.NewWriter(fdDep)
 311         cleanup := func() {
 312                 lockRelease()
 313                 if fdDepOpened {
 314                         fdDep.Close()
 315                 }
 316                 if fdDepExists {
 317                         os.Remove(fdDep.Name())
 318                 }
 319         }
 320         if err = depBuildWrite(fdDepW, BuildUUID); err != nil {
 321                 cleanup()
 322                 return TgtError{tgt, ErrLine(err)}
 323         }
 324
 325         var cwd string
 326         var dirPrefix string
 327         var doFile *Tgt
 328         var doFileT string
 329         basename := tgtT
 330         runErr := RunError{Tgt: tgt}
 331         // Determine basename and DIRPREFIX
 332         {
 333                 doFileRelPath, upLevels, err := findDo(fdDepW, fdDep.Name(), tgtH, tgtT)
 334                 if err != nil {
 335                         cleanup()
 336                         return TgtError{tgt, ErrLine(err)}
 337                 }
 338                 if doFileRelPath == "" {
 339                         cleanup()
 340                         return TgtError{tgt, errors.New("no .do found")}
 341                 }
 342                 ents := strings.Split(tgtH, "/")
 343                 ents = ents[len(ents)-upLevels:]
 344                 dirPrefix = path.Join(ents...)
 345                 ups := make([]string, 0, upLevels+2)
 346                 ups = append(ups, tgtH)
 347                 for i := 0; i < upLevels; i++ {
 348                         ups = append(ups, "..")
 349                 }
 350                 ups = append(ups, doFileRelPath)
 351                 cwd = path.Clean(path.Join(ups[:len(ups)-1]...))
 352                 doFile = NewTgt(path.Join(ups...))
 353                 doFileT = path.Base(doFile.a)
 354                 if strings.HasPrefix(doFileT, "default.") {
 355                         basename = basename[:len(basename)-(len(doFileT)-len("default.")-len(".do"))-1]
 356                         runErr.DoFile = doFile.rel
 357                 }
 358         }
 359
 360         if err = depWrite(fdDepW, fdDep.Name(), tgtH, doFile, ""); err != nil {
 361                 cleanup()
 362                 return TgtError{tgt, ErrLine(err)}
 363         }
 364         if err = fdDepW.Flush(); err != nil {
 365                 cleanup()
 366                 return TgtError{tgt, ErrLine(err)}
 367         }
 368         fdDep.Close()
 369         fdDepOpened = false
 370         tracef(CWait, "%s", runErr.Name())
 371
 372         // Prepare command line
 373         var cmdName string
 374         var args []string
 375         if err = unix.Access(doFile.rel, unix.X_OK); err == nil {
 376                 cmdName = doFile.a
 377                 args = make([]string, 0, 3)
 378         } else {
 379                 cmdName = "/bin/sh"
 380                 if traced || TracedAll {
 381                         args = append(args, "-ex")
 382                 } else {
 383                         args = append(args, "-e")
 384                 }
 385                 args = append(args, doFileT)
 386         }
 387
 388         // Temporary file for stdout
 389         fdStdout, err := tempfile(tgtH, tgtT)
 390         if err != nil {
 391                 cleanup()
 392                 return TgtError{tgt, ErrLine(err)}
 393         }
 394         fdStdout.Close()
 395         tmpPath := fdStdout.Name() + ".3" // and for $3
 396         tmpPathRel := mustRel(cwd, tmpPath)
 397         args = append(
 398                 args,
 399                 path.Join(dirPrefix, tgtT),
 400                 path.Join(dirPrefix, basename),
 401                 tmpPathRel,
 402         )
 403         shCtx = fmt.Sprintf(
 404                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 405                 tgt, cmdName, args, cwd, dirPrefix,
 406         )
 407
 408         cmd := exec.Command(cmdName, args...)
 409         cmd.Dir = cwd
 410         // cmd.Stdin reads from /dev/null by default
 411         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 412         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 413         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 414
 415         childStderrPrefixRaw := make([]byte, 8)
 416         if _, err = io.ReadFull(rand.Reader, childStderrPrefixRaw); err != nil {
 417                 panic(err)
 418         }
 419         childStderrPrefix := hex.EncodeToString(childStderrPrefixRaw)
 420         cmd.Env = append(cmd.Env, fmt.Sprintf(
 421                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 422         ))
 423
 424         fdNum := 0
 425         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 426         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 427         fdNum++
 428         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 429         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 430         fdNum++
 431
 432         if FdStatus == nil {
 433                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 434         } else {
 435                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 436                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 437                 fdNum++
 438         }
 439
 440         // Preparing stderr
 441         var fdStderr *os.File
 442         if StderrKeep {
 443                 fdStderr, err = os.OpenFile(
 444                         path.Join(redoDir, tgtT+LogSuffix),
 445                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 446                         os.FileMode(0666),
 447                 )
 448                 if err != nil {
 449                         cleanup()
 450                         return TgtError{tgt, ErrLine(err)}
 451                 }
 452         }
 453         tracef(CDebug, "%s", shCtx)
 454
 455         jsNeedsRelease = false
 456         Jobs.Add(1)
 457         go func() {
 458                 if JSR == nil {
 459                         // infinite jobs
 460                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 461                 } else {
 462                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 463                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 464                         makeFlags := fmt.Sprintf(
 465                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 466                         )
 467                         makeFlags = strings.Trim(makeFlags, " ")
 468                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 469                         fdNum += 2
 470                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 471                 }
 472
 473                 if FdStatus != nil {
 474                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 475                                 log.Fatal(err)
 476                         }
 477                 }
 478
 479                 defer jsRelease(shCtx, jsToken)
 480
 481                 var finished time.Time
 482                 var exitErr *exec.ExitError
 483                 started := time.Now()
 484                 runErr.Started = &started
 485                 fdStdout, err = os.OpenFile(fdStdout.Name(), os.O_RDWR, os.FileMode(0666))
 486                 if err != nil {
 487                         if fdStderr != nil {
 488                                 fdStderr.Close()
 489                         }
 490                         runErr.Err = err
 491                         errs <- runErr
 492                         return
 493                 }
 494                 cmd.Stdout = fdStdout
 495                 fdDep, err = os.OpenFile(fdDep.Name(), os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 496                 if err != nil {
 497                         if fdStderr != nil {
 498                                 fdStderr.Close()
 499                         }
 500                         fdStdout.Close()
 501                         runErr.Err = err
 502                         errs <- runErr
 503                         return
 504                 }
 505                 fdDepOpened = true
 506                 fdDepW.Reset(fdDep)
 507                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 508                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 509                 fdNum++
 510                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 511
 512                 defer func() {
 513                         if fdDepOpened {
 514                                 fdDep.Close()
 515                         }
 516                         fdStdout.Close()
 517                         if fdStderr != nil {
 518                                 fdStderr.Close()
 519                                 logRecPath := path.Join(redoDir, tgtT+LogRecSuffix)
 520                                 if fdStderr, err = os.OpenFile(
 521                                         logRecPath,
 522                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 523                                         os.FileMode(0666),
 524                                 ); err == nil {
 525                                         fields := []recfile.Field{
 526                                                 {Name: "Build", Value: BuildUUID.String()},
 527                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 528                                                 {Name: "Cwd", Value: cwd},
 529                                         }
 530                                         if cmd.Process != nil {
 531                                                 fields = append(fields, recfile.Field{
 532                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 533                                                 })
 534                                         }
 535                                         ts := new(tai64n.TAI64N)
 536                                         ts.FromTime(started)
 537                                         fields = append(fields,
 538                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 539                                         )
 540                                         ts.FromTime(finished)
 541                                         fields = append(fields,
 542                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 543                                         fields = append(fields, recfile.Field{
 544                                                 Name:  "Duration",
 545                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 546                                         })
 547                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 548                                         for _, arg := range args {
 549                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 550                                         }
 551                                         for _, env := range cmd.Env {
 552                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 553                                         }
 554                                         if exitErr != nil {
 555                                                 fields = append(fields, recfile.Field{
 556                                                         Name:  "ExitCode",
 557                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 558                                                 })
 559                                         }
 560
 561                                         w := bufio.NewWriter(fdStderr)
 562                                         {
 563                                                 var ifchanges []string
 564                                                 ifchanges, err = depReadOnlyIfchanges(tgt.dep)
 565                                                 if err != nil {
 566                                                         err = ErrLine(err)
 567                                                         goto Err
 568                                                 }
 569                                                 for _, ifchange := range ifchanges {
 570                                                         fields = append(fields, recfile.Field{
 571                                                                 Name:  "Ifchange",
 572                                                                 Value: ifchange,
 573                                                         })
 574                                                 }
 575                                         }
 576                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 577                                         if err != nil {
 578                                                 err = ErrLine(err)
 579                                                 goto Err
 580                                         }
 581                                         err = ErrLine(w.Flush())
 582                                 Err:
 583                                         if err != nil {
 584                                                 log.Print(err)
 585                                                 os.Remove(logRecPath)
 586                                         }
 587                                         fdStderr.Close()
 588                                 } else {
 589                                         log.Println("can not open", logRecPath, ":", err)
 590                                 }
 591                         }
 592                         lockRelease()
 593                         if fdDepExists {
 594                                 os.Remove(fdDep.Name())
 595                         }
 596                         os.Remove(fdStdout.Name())
 597                         os.Remove(tmpPath)
 598                         if FdStatus != nil {
 599                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 600                                         log.Fatal(err)
 601                                 }
 602                         }
 603                         Jobs.Done()
 604                 }()
 605                 stderr, err := cmd.StderrPipe()
 606                 if err != nil {
 607                         runErr.Err = err
 608                         errs <- runErr
 609                         return
 610                 }
 611                 started = time.Now()
 612                 err = cmd.Start()
 613                 if err != nil {
 614                         runErr.Err = err
 615                         errs <- runErr
 616                         return
 617                 }
 618                 RunningProcsM.Lock()
 619                 RunningProcs[cmd.Process.Pid] = cmd.Process
 620                 RunningProcsM.Unlock()
 621                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 622                 tracef(CDebug, "%s runs %s", tgt, pid)
 623
 624                 stderrTerm := make(chan struct{})
 625                 go func() {
 626                         scanner := bufio.NewScanner(stderr)
 627                         var line string
 628                         ts := new(tai64n.TAI64N)
 629                         for scanner.Scan() {
 630                                 line = scanner.Text()
 631                                 if strings.HasPrefix(line, childStderrPrefix) {
 632                                         line = line[len(childStderrPrefix):]
 633                                         if StderrPrefix == "" {
 634                                                 withPrependedTgt(line)
 635                                         } else {
 636                                                 stderrWrite(StderrPrefix + line + "\n")
 637                                         }
 638                                         continue
 639                                 }
 640                                 if fdStderr != nil {
 641                                         ts.FromTime(time.Now())
 642                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 643                                 }
 644                                 if StderrSilent {
 645                                         continue
 646                                 }
 647                                 if MyPID != 0 {
 648                                         line = pid + " " + line
 649                                 }
 650                                 if StderrPrefix == "" {
 651                                         withPrependedTgt("[" + tgt.rel + "]" + line)
 652                                 } else {
 653                                         stderrWrite(StderrPrefix + "[" + tgt.rel + "]" + line + "\n")
 654                                 }
 655                         }
 656                         close(stderrTerm)
 657                 }()
 658
 659                 // Wait for job completion
 660                 <-stderrTerm
 661                 err = cmd.Wait()
 662                 RunningProcsM.Lock()
 663                 delete(RunningProcs, cmd.Process.Pid)
 664                 RunningProcsM.Unlock()
 665                 finished = time.Now()
 666                 runErr.Finished = &finished
 667                 if err != nil {
 668                         exitErr = err.(*exec.ExitError)
 669                         runErr.Err = err
 670                         errs <- runErr
 671                         return
 672                 }
 673
 674                 // Was $1 touched?
 675                 if inode, err := inodeFromFileByPath(tgt.a); err == nil {
 676                         if inodePrev == nil {
 677                                 runErr.Err = Err1WasTouched
 678                                 errs <- runErr
 679                                 return
 680                         }
 681                         if !inode.Equals(inodePrev) {
 682                                 runErr.Err = Err1WasTouched
 683                                 errs <- runErr
 684                                 return
 685                         }
 686                 }
 687
 688                 // Does it produce both stdout and tmp?
 689                 fiStdout, err := os.Stat(fdStdout.Name())
 690                 if err != nil {
 691                         runErr.Err = ErrLine(err)
 692                         errs <- runErr
 693                         return
 694                 }
 695                 tmpExists := false
 696                 _, err = os.Stat(tmpPath)
 697                 if err == nil {
 698                         if fiStdout.Size() > 0 {
 699                                 runErr.Err = errors.New("created both tmp and stdout")
 700                                 errs <- runErr
 701                                 return
 702                         }
 703                         tmpExists = true
 704                 } else if !errors.Is(err, fs.ErrNotExist) {
 705                         runErr.Err = ErrLine(err)
 706                         errs <- runErr
 707                         return
 708                 }
 709
 710                 // Determine what file we must process at last
 711                 var fd *os.File
 712                 var chmod fs.FileMode
 713                 if tmpExists {
 714                         fd, err = os.Open(tmpPath)
 715                         if err != nil {
 716                                 err = ErrLine(err)
 717                                 goto Finish
 718                         }
 719                         defer fd.Close()
 720                         if fi, rerr := fd.Stat(); rerr == nil {
 721                                 chmod = fi.Mode()
 722                         } else {
 723                                 err = ErrLine(rerr)
 724                                 goto Finish
 725                         }
 726                 } else if fiStdout.Size() > 0 {
 727                         fd = fdStdout
 728                 }
 729
 730                 // Do we need to ifcreate it, or ifchange with renaming?
 731                 if fd == nil {
 732                         os.Remove(tgt.a)
 733                         err = ifcreate(fdDepW, fdDep.Name(), tgtT)
 734                         if err != nil {
 735                                 err = ErrLine(err)
 736                                 goto Finish
 737                         }
 738                 } else {
 739                         var hsh Hash
 740                         if hshPrev != "" {
 741                                 _, err = fd.Seek(0, io.SeekStart)
 742                                 if err != nil {
 743                                         err = ErrLine(err)
 744                                         goto Finish
 745                                 }
 746                                 hsh, err = fileHash(fd)
 747                                 if err != nil {
 748                                         err = ErrLine(err)
 749                                         goto Finish
 750                                 }
 751                                 if hsh == hshPrev {
 752                                         tracef(CDebug, "%s has same hash, not renaming", tgt)
 753                                         err = ErrLine(os.Remove(fd.Name()))
 754                                         if err != nil {
 755                                                 goto Finish
 756                                         }
 757                                         if chmod != 0 {
 758                                                 err = ErrLine(os.Chmod(tgt.a, chmod))
 759                                                 if err != nil {
 760                                                         goto Finish
 761                                                 }
 762                                         }
 763                                         err = ErrLine(os.Chtimes(tgt.a, finished, finished))
 764                                         if err != nil {
 765                                                 goto Finish
 766                                         }
 767                                         if !NoSync {
 768                                                 err = ErrLine(syncDir(tgtH))
 769                                                 if err != nil {
 770                                                         goto Finish
 771                                                 }
 772                                         }
 773                                         err = ErrLine(depWrite(fdDepW, fdDep.Name(), tgtH, tgt, hsh))
 774                                         if err != nil {
 775                                                 goto Finish
 776                                         }
 777                                         goto RecCommit
 778                                 }
 779                         }
 780                         if !NoSync {
 781                                 err = ErrLine(fd.Sync())
 782                                 if err != nil {
 783                                         goto Finish
 784                                 }
 785                         }
 786                         err = ErrLine(os.Rename(fd.Name(), tgt.a))
 787                         if err != nil {
 788                                 goto Finish
 789                         }
 790                         if !NoSync {
 791                                 err = ErrLine(syncDir(tgtH))
 792                                 if err != nil {
 793                                         goto Finish
 794                                 }
 795                         }
 796                         err = ErrLine(depWrite(fdDepW, fdDep.Name(), tgtH, tgt, hsh))
 797                         if err != nil {
 798                                 goto Finish
 799                         }
 800                 }
 801
 802         RecCommit:
 803                 // Commit .dep
 804                 err = ErrLine(fdDepW.Flush())
 805                 if err != nil {
 806                         goto Finish
 807                 }
 808                 if !NoSync {
 809                         err = ErrLine(fdDep.Sync())
 810                         if err != nil {
 811                                 goto Finish
 812                         }
 813                 }
 814                 err = ErrLine(os.Rename(fdDep.Name(), tgt.dep))
 815                 if err != nil {
 816                         goto Finish
 817                 }
 818                 fdDepExists = false
 819                 if !NoSync {
 820                         err = ErrLine(syncDir(redoDir))
 821                         if err != nil {
 822                                 goto Finish
 823                         }
 824                 }
 825                 fdDep.Close()
 826                 fdDepOpened = false
 827
 828                 // Post-commit .dep sanitizing
 829                 dep, err = depRead(tgt)
 830                 if err == nil {
 831                         ifchangeSeen := make(map[string]struct{}, len(dep.ifchanges))
 832                         for _, ifchange := range dep.ifchanges {
 833                                 ifchangeSeen[ifchange.tgt.a] = struct{}{}
 834                         }
 835                         for _, ifcreate := range dep.ifcreates {
 836                                 if _, exists := ifchangeSeen[ifcreate.a]; exists {
 837                                         tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
 838                                 }
 839                         }
 840                 } else if errors.Is(err, fs.ErrNotExist) {
 841                         err = nil
 842                 } else {
 843                         err = ErrLine(err)
 844                         goto Finish
 845                 }
 846
 847         Finish:
 848                 runErr.Err = err
 849                 errs <- runErr
 850         }()
 851         return nil
 852 }
 853
 854 func isOkRun(err error) bool {
 855         if err == nil {
 856                 return true
 857         }
 858         var runErr RunError
 859         if errors.As(err, &runErr) && runErr.Err == nil {
 860                 tracef(CRedo, "%s", runErr.Name())
 861                 return true
 862         }
 863         tracef(CErr, "%s", err)
 864         return false
 865 }