run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2022 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 // Targets runner
  19
  20 package main
  21
  22 import (
  23         "bufio"
  24         "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 _, err := os.Stat(pth); err == nil {
 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)
 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)
 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                         if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
 246                                 log.Fatalln(err)
 247                         }
 248                         lockRelease()
 249                         tracef(CDebug, "waiting done: %s", tgtOrig)
 250                         if FdStatus != nil {
 251                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 252                                         log.Fatalln(err)
 253                                 }
 254                         }
 255                         var depInfo *DepInfo
 256                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 257                         if err != nil {
 258                                 if os.IsNotExist(err) {
 259                                         err = errors.New("was not built: no .rec")
 260                                 }
 261                                 goto Finish
 262                         }
 263                         defer fdDep.Close()
 264                         depInfo, err = depRead(fdDep)
 265                         if err != nil {
 266                                 goto Finish
 267                         }
 268                         if depInfo.build != BuildUUID {
 269                                 err = errors.New("was not built: build differs")
 270                         }
 271                 Finish:
 272                         if err != nil {
 273                                 err = TgtError{tgtOrig, err}
 274                                 fdLock.Close()
 275                         }
 276                         errs <- err
 277                 }()
 278                 return nil
 279         }
 280
 281         // Check if target is not modified externally
 282         modified, inodePrev, hshPrev, err := isModified(cwd, redoDir, tgt)
 283         if err != nil {
 284                 lockRelease()
 285                 return TgtError{tgtOrig, err}
 286         }
 287         if modified {
 288                 lockRelease()
 289                 if StopIfMod {
 290                         return fmt.Errorf("%s externally modified", tgtOrig)
 291                 }
 292                 tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 293                 go func() {
 294                         errs <- nil
 295                 }()
 296                 return nil
 297         }
 298
 299         // Start preparing .rec
 300         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 301         if err != nil {
 302                 lockRelease()
 303                 return TgtError{tgtOrig, err}
 304         }
 305         fdDepPath := fdDep.Name()
 306         cleanup := func() {
 307                 lockRelease()
 308                 fdDep.Close()
 309                 os.Remove(fdDep.Name())
 310         }
 311         if _, err = recfile.NewWriter(fdDep).WriteFields(
 312                 recfile.Field{Name: "Build", Value: BuildUUID},
 313         ); err != nil {
 314                 cleanup()
 315                 return TgtError{tgtOrig, err}
 316         }
 317
 318         // Find .do
 319         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 320         if err != nil {
 321                 cleanup()
 322                 return TgtError{tgtOrig, err}
 323         }
 324         if doFile == "" {
 325                 cleanup()
 326                 return TgtError{tgtOrig, errors.New("no .do found")}
 327         }
 328
 329         // Determine basename and DIRPREFIX
 330         doFileRelPath := doFile
 331         ents := strings.Split(cwd, "/")
 332         ents = ents[len(ents)-upLevels:]
 333         dirPrefix := path.Join(ents...)
 334         cwdOrig := cwd
 335         for i := 0; i < upLevels; i++ {
 336                 cwd = path.Join(cwd, "..")
 337                 doFileRelPath = path.Join("..", doFileRelPath)
 338         }
 339         cwd = path.Clean(cwd)
 340         doFilePath := path.Join(cwd, doFile)
 341         basename := tgt
 342         runErr := RunError{Tgt: tgtOrig}
 343         if strings.HasPrefix(doFile, "default.") {
 344                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 345                 runErr.DoFile = doFileRelPath
 346         }
 347
 348         if err = depWrite(fdDep, cwdOrig, doFileRelPath, ""); err != nil {
 349                 cleanup()
 350                 return TgtError{tgtOrig, err}
 351         }
 352         fdDep.Close()
 353         tracef(CWait, "%s", runErr.Name())
 354
 355         // Prepare command line
 356         var cmdName string
 357         var args []string
 358         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 359                 cmdName = doFilePath
 360                 args = make([]string, 0, 3)
 361         } else {
 362                 cmdName = "/bin/sh"
 363                 if traced || TracedAll {
 364                         args = append(args, "-ex")
 365                 } else {
 366                         args = append(args, "-e")
 367                 }
 368                 args = append(args, doFile)
 369         }
 370
 371         // Temporary file for stdout
 372         fdStdout, err := tempfile(cwdOrig, tgt)
 373         if err != nil {
 374                 cleanup()
 375                 return TgtError{tgtOrig, err}
 376         }
 377         stdoutPath := fdStdout.Name()
 378         fdStdout.Close()
 379         tmpPath := stdoutPath + ".3" // and for $3
 380         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 381         if err != nil {
 382                 panic(err)
 383         }
 384         args = append(
 385                 args,
 386                 path.Join(dirPrefix, tgt),
 387                 path.Join(dirPrefix, basename),
 388                 tmpPathRel,
 389         )
 390         shCtx = fmt.Sprintf(
 391                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 392                 tgtOrig, cmdName, args, cwd, dirPrefix,
 393         )
 394
 395         cmd := exec.Command(cmdName, args...)
 396         cmd.Dir = cwd
 397         // cmd.Stdin reads from /dev/null by default
 398         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 399         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 400         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 401
 402         childStderrPrefixRaw := make([]byte, 8)
 403         if _, err = io.ReadFull(rand.Reader, childStderrPrefixRaw); err != nil {
 404                 panic(err)
 405         }
 406         childStderrPrefix := hex.EncodeToString(childStderrPrefixRaw)
 407         cmd.Env = append(cmd.Env, fmt.Sprintf(
 408                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 409         ))
 410
 411         fdNum := 0
 412         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 413         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 414         fdNum++
 415         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 416         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 417         fdNum++
 418
 419         if FdStatus == nil {
 420                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 421         } else {
 422                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 423                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 424                 fdNum++
 425         }
 426
 427         // Preparing stderr
 428         var fdStderr *os.File
 429         if StderrKeep {
 430                 fdStderr, err = os.OpenFile(
 431                         path.Join(redoDir, tgt+LogSuffix),
 432                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 433                         os.FileMode(0666),
 434                 )
 435                 if err != nil {
 436                         cleanup()
 437                         return TgtError{tgtOrig, err}
 438                 }
 439         }
 440         tracef(CDebug, "%s", shCtx)
 441
 442         jsNeedsRelease = false
 443         Jobs.Add(1)
 444         go func() {
 445                 if JSR == nil {
 446                         // infinite jobs
 447                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 448                 } else {
 449                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 450                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 451                         makeFlags := fmt.Sprintf(
 452                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 453                         )
 454                         makeFlags = strings.Trim(makeFlags, " ")
 455                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 456                         fdNum += 2
 457                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 458                 }
 459
 460                 if FdStatus != nil {
 461                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 462                                 log.Fatalln(err)
 463                         }
 464                 }
 465
 466                 defer jsRelease(shCtx, jsToken)
 467
 468                 var finished time.Time
 469                 var exitErr *exec.ExitError
 470                 started := time.Now()
 471                 runErr.Started = &started
 472                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 473                 if err != nil {
 474                         if fdStderr != nil {
 475                                 fdStderr.Close()
 476                         }
 477                         runErr.Err = err
 478                         errs <- runErr
 479                         return
 480                 }
 481                 cmd.Stdout = fdStdout
 482                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 483                 if err != nil {
 484                         if fdStderr != nil {
 485                                 fdStderr.Close()
 486                         }
 487                         fdStdout.Close()
 488                         runErr.Err = err
 489                         errs <- runErr
 490                         return
 491                 }
 492                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 493                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 494                 fdNum++
 495                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 496
 497                 defer func() {
 498                         fdDep.Close()
 499                         fdStdout.Close()
 500                         if fdStderr != nil {
 501                                 fdStderr.Close()
 502                                 logRecPath := path.Join(redoDir, tgt+LogRecSuffix)
 503                                 if fdStderr, err = os.OpenFile(
 504                                         logRecPath,
 505                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 506                                         os.FileMode(0666),
 507                                 ); err == nil {
 508                                         fields := []recfile.Field{
 509                                                 {Name: "Build", Value: BuildUUID},
 510                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 511                                                 {Name: "Cwd", Value: cwd},
 512                                         }
 513                                         if cmd.Process != nil {
 514                                                 fields = append(fields, recfile.Field{
 515                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 516                                                 })
 517                                         }
 518                                         ts := new(tai64n.TAI64N)
 519                                         ts.FromTime(started)
 520                                         fields = append(fields,
 521                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 522                                         )
 523                                         ts.FromTime(finished)
 524                                         fields = append(fields,
 525                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 526                                         fields = append(fields, recfile.Field{
 527                                                 Name:  "Duration",
 528                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 529                                         })
 530                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 531                                         for _, arg := range args {
 532                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 533                                         }
 534                                         for _, env := range cmd.Env {
 535                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 536                                         }
 537                                         if exitErr != nil {
 538                                                 fields = append(fields, recfile.Field{
 539                                                         Name:  "ExitCode",
 540                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 541                                                 })
 542                                         }
 543                                         w := bufio.NewWriter(fdStderr)
 544
 545                                         var depInfo *DepInfo
 546                                         fdDep, err := os.Open(fdDepPath)
 547                                         if err != nil {
 548                                                 goto Err
 549                                         }
 550                                         depInfo, err = depRead(fdDep)
 551                                         fdDep.Close()
 552                                         if err != nil {
 553                                                 goto Err
 554                                         }
 555                                         for _, dep := range depInfo.ifchanges {
 556                                                 fields = append(fields, recfile.Field{
 557                                                         Name:  "Ifchange",
 558                                                         Value: dep["Target"],
 559                                                 })
 560                                         }
 561                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 562                                         if err != nil {
 563                                                 goto Err
 564                                         }
 565                                         err = w.Flush()
 566                                 Err:
 567                                         if err != nil {
 568                                                 log.Println(err)
 569                                                 os.Remove(logRecPath)
 570                                         }
 571                                         fdStderr.Close()
 572                                 } else {
 573                                         log.Println("can not open", logRecPath, ":", err)
 574                                 }
 575                         }
 576                         lockRelease()
 577                         os.Remove(fdDep.Name())
 578                         os.Remove(fdStdout.Name())
 579                         os.Remove(tmpPath)
 580                         os.Remove(fdLock.Name())
 581                         if FdStatus != nil {
 582                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 583                                         log.Fatalln(err)
 584                                 }
 585                         }
 586                         Jobs.Done()
 587                 }()
 588                 stderr, err := cmd.StderrPipe()
 589                 if err != nil {
 590                         runErr.Err = err
 591                         errs <- runErr
 592                         return
 593                 }
 594                 started = time.Now()
 595                 err = cmd.Start()
 596                 if err != nil {
 597                         runErr.Err = err
 598                         errs <- runErr
 599                         return
 600                 }
 601                 RunningProcsM.Lock()
 602                 RunningProcs[cmd.Process.Pid] = cmd.Process
 603                 RunningProcsM.Unlock()
 604                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 605                 tracef(CDebug, "%s runs %s", tgtOrig, pid)
 606
 607                 stderrTerm := make(chan struct{})
 608                 go func() {
 609                         scanner := bufio.NewScanner(stderr)
 610                         var line string
 611                         ts := new(tai64n.TAI64N)
 612                         for scanner.Scan() {
 613                                 line = scanner.Text()
 614                                 if strings.HasPrefix(line, childStderrPrefix) {
 615                                         line = line[len(childStderrPrefix):]
 616                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 617                                         continue
 618                                 }
 619                                 if fdStderr != nil {
 620                                         ts.FromTime(time.Now())
 621                                         LogMutex.Lock()
 622                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 623                                         LogMutex.Unlock()
 624                                 }
 625                                 if StderrSilent {
 626                                         continue
 627                                 }
 628                                 if MyPid == 0 {
 629                                         tracef(CNone, "%s", line)
 630                                 } else {
 631                                         tracef(CNone, "%s %s", pid, line)
 632                                 }
 633                         }
 634                         close(stderrTerm)
 635                 }()
 636
 637                 // Wait for job completion
 638                 <-stderrTerm
 639                 err = cmd.Wait()
 640                 RunningProcsM.Lock()
 641                 delete(RunningProcs, cmd.Process.Pid)
 642                 RunningProcsM.Unlock()
 643                 finished = time.Now()
 644                 runErr.Finished = &finished
 645                 if err != nil {
 646                         exitErr = err.(*exec.ExitError)
 647                         runErr.Err = err
 648                         errs <- runErr
 649                         return
 650                 }
 651
 652                 // Was $1 touched?
 653                 if inode, err := inodeFromFileByPath(path.Join(cwdOrig, tgt)); err == nil {
 654                         if inodePrev == nil {
 655                                 runErr.Err = Err1WasTouched
 656                                 errs <- runErr
 657                                 return
 658                         }
 659                         if err != nil {
 660                                 runErr.Err = err
 661                                 errs <- runErr
 662                                 return
 663                         }
 664                         if !inode.Equals(inodePrev) {
 665                                 runErr.Err = Err1WasTouched
 666                                 errs <- runErr
 667                                 return
 668                         }
 669                 }
 670
 671                 if inodePrev != nil {
 672                         if inode, err := inodeFromFileByPath(path.Join(cwdOrig, tgt)); err == nil {
 673                                 if !inode.Equals(inodePrev) {
 674                                         runErr.Err = Err1WasTouched
 675                                         errs <- runErr
 676                                         return
 677                                 }
 678                         }
 679                 }
 680
 681                 // Does it produce both stdout and tmp?
 682                 fiStdout, err := os.Stat(fdStdout.Name())
 683                 if err != nil {
 684                         runErr.Err = err
 685                         errs <- runErr
 686                         return
 687                 }
 688                 tmpExists := false
 689                 _, err = os.Stat(tmpPath)
 690                 if err == nil {
 691                         if fiStdout.Size() > 0 {
 692                                 runErr.Err = errors.New("created both tmp and stdout")
 693                                 errs <- runErr
 694                                 return
 695                         }
 696                         tmpExists = true
 697                 } else if !os.IsNotExist(err) {
 698                         runErr.Err = err
 699                         errs <- runErr
 700                         return
 701                 }
 702
 703                 // Determine what file we must process at last
 704                 var fd *os.File
 705                 if tmpExists {
 706                         fd, err = os.Open(tmpPath)
 707                         if err != nil {
 708                                 goto Finish
 709                         }
 710                         defer fd.Close()
 711                 } else if fiStdout.Size() > 0 {
 712                         fd = fdStdout
 713                 }
 714
 715                 // Do we need to ifcreate it, or ifchange with renaming?
 716                 if fd == nil {
 717                         os.Remove(path.Join(cwdOrig, tgt))
 718                         err = ifcreate(fdDep, tgt)
 719                         if err != nil {
 720                                 goto Finish
 721                         }
 722                 } else {
 723                         var hsh string
 724                         if hshPrev != "" {
 725                                 _, err = fd.Seek(0, io.SeekStart)
 726                                 if err != nil {
 727                                         goto Finish
 728                                 }
 729                                 hsh, err = fileHash(fd)
 730                                 if err != nil {
 731                                         goto Finish
 732                                 }
 733                                 if hsh == hshPrev {
 734                                         tracef(CDebug, "%s has same hash, not renaming", tgtOrig)
 735                                         err = os.Remove(fd.Name())
 736                                         if err != nil {
 737                                                 goto Finish
 738                                         }
 739                                         err = os.Chtimes(path.Join(cwdOrig, tgt), finished, finished)
 740                                         if err != nil {
 741                                                 goto Finish
 742                                         }
 743                                         if !NoSync {
 744                                                 err = syncDir(cwdOrig)
 745                                                 if err != nil {
 746                                                         goto Finish
 747                                                 }
 748                                         }
 749                                         err = depWrite(fdDep, cwdOrig, tgt, hshPrev)
 750                                         if err != nil {
 751                                                 goto Finish
 752                                         }
 753                                         goto RecCommit
 754                                 }
 755                         }
 756                         if !NoSync {
 757                                 err = fd.Sync()
 758                                 if err != nil {
 759                                         goto Finish
 760                                 }
 761                         }
 762                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 763                         if err != nil {
 764                                 goto Finish
 765                         }
 766                         if !NoSync {
 767                                 err = syncDir(cwdOrig)
 768                                 if err != nil {
 769                                         goto Finish
 770                                 }
 771                         }
 772                         err = depWrite(fdDep, cwdOrig, tgt, hsh)
 773                         if err != nil {
 774                                 goto Finish
 775                         }
 776                 }
 777
 778         RecCommit:
 779                 // Commit .rec
 780                 if !NoSync {
 781                         err = fdDep.Sync()
 782                         if err != nil {
 783                                 goto Finish
 784                         }
 785                 }
 786                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 787                 err = os.Rename(fdDep.Name(), fdDepPath)
 788                 if err != nil {
 789                         goto Finish
 790                 }
 791                 if !NoSync {
 792                         err = syncDir(redoDir)
 793                         if err != nil {
 794                                 goto Finish
 795                         }
 796                 }
 797
 798                 // Post-commit .rec sanitizing
 799                 fdDep.Close()
 800                 if fdDepR, err := os.Open(fdDepPath); err == nil {
 801                         depInfo, err := depRead(fdDepR)
 802                         fdDepR.Close()
 803                         if err != nil {
 804                                 goto Finish
 805                         }
 806                         ifchangeSeen := make(map[string]struct{}, len(depInfo.ifchanges))
 807                         for _, dep := range depInfo.ifchanges {
 808                                 ifchangeSeen[dep["Target"]] = struct{}{}
 809                         }
 810                         for _, dep := range depInfo.ifcreates {
 811                                 if _, exists := ifchangeSeen[dep]; exists {
 812                                         tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
 813                                 }
 814                         }
 815                 }
 816
 817         Finish:
 818                 runErr.Err = err
 819                 errs <- runErr
 820         }()
 821         return nil
 822 }
 823
 824 func isOkRun(err error) bool {
 825         if err == nil {
 826                 return true
 827         }
 828         var runErr RunError
 829         if errors.As(err, &runErr) && runErr.Err == nil {
 830                 tracef(CRedo, "%s", runErr.Name())
 831                 return true
 832         }
 833         tracef(CErr, "%s", err)
 834         return false
 835 }