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