run.go

   1 /*
   2 goredo -- djb's redo implementation on pure Go
   3 Copyright (C) 2020-2022 Sergey Matveev <stargrave@stargrave.org>
   4
   5 This program is free software: you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation, version 3 of the License.
   8
   9 This program is distributed in the hope that it will be useful,
  10 but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 GNU General Public License for more details.
  13
  14 You should have received a copy of the GNU General Public License
  15 along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 */
  17
  18 // Targets runner
  19
  20 package main
  21
  22 import (
  23         "bufio"
  24         "errors"
  25         "flag"
  26         "fmt"
  27         "io"
  28         "log"
  29         "os"
  30         "os/exec"
  31         "path"
  32         "path/filepath"
  33         "strconv"
  34         "strings"
  35         "sync"
  36         "syscall"
  37         "time"
  38
  39         "go.cypherpunks.ru/recfile"
  40         "go.cypherpunks.ru/tai64n/v2"
  41         "golang.org/x/sys/unix"
  42 )
  43
  44 const (
  45         EnvDepFd        = "REDO_DEP_FD"
  46         EnvDirPrefix    = "REDO_DIRPREFIX"
  47         EnvDepCwd       = "REDO_DEP_CWD"
  48         EnvBuildUUID    = "REDO_BUILD_UUID"
  49         EnvStderrPrefix = "REDO_STDERR_PREFIX"
  50         EnvTrace        = "REDO_TRACE"
  51         EnvStderrKeep   = "REDO_LOGS"
  52         EnvStderrSilent = "REDO_SILENT"
  53         EnvNoSync       = "REDO_NO_SYNC"
  54         EnvStopIfMod    = "REDO_STOP_IF_MODIFIED"
  55
  56         RedoDir      = ".redo"
  57         LockSuffix   = ".lock"
  58         DepSuffix    = ".rec"
  59         TmpPrefix    = ".redo."
  60         LogSuffix    = ".log"
  61         LogRecSuffix = ".log-rec"
  62 )
  63
  64 var (
  65         NoSync       = false
  66         StderrKeep   = false
  67         StderrSilent = false
  68         StderrPrefix string
  69         StopIfMod    = false
  70         Jobs         sync.WaitGroup
  71
  72         flagTrace          *bool
  73         flagTraceAll       *bool
  74         flagStderrKeep     *bool
  75         flagStderrSilent   *bool
  76         flagForcedIfchange *bool
  77
  78         TracedAll bool
  79
  80         RunningProcs  = map[int]*os.Process{}
  81         RunningProcsM sync.Mutex
  82
  83         Err1WasTouched = errors.New("$1 was explicitly touched")
  84 )
  85
  86 func init() {
  87         cmdName := CmdName()
  88         if !(cmdName == CmdNameRedo || cmdName == CmdNameRedoIfchange) {
  89                 return
  90         }
  91         flagTrace = flag.Bool("x", false, "trace (sh -x) current targets")
  92         flagTraceAll = flag.Bool("xx", false,
  93                 fmt.Sprintf("trace (sh -x) all targets (%s=1)", EnvTrace))
  94         flagStderrKeep = flag.Bool("k", false,
  95                 fmt.Sprintf("keep job's stderr (%s=1)", EnvStderrKeep))
  96         flagStderrSilent = flag.Bool("s", false,
  97                 fmt.Sprintf("silent, do not print job's stderr (%s=1)", EnvStderrSilent))
  98         flagForcedIfchange = flag.Bool("f", false, "forced redo-ifchange")
  99 }
 100
 101 type RunError struct {
 102         Tgt      string
 103         DoFile   string
 104         Started  *time.Time
 105         Finished *time.Time
 106         Err      error
 107 }
 108
 109 func (e *RunError) Name() string {
 110         var name string
 111         if e.DoFile == "" {
 112                 name = e.Tgt
 113         } else {
 114                 name = fmt.Sprintf("%s (%s)", e.Tgt, e.DoFile)
 115         }
 116         if e.Finished == nil {
 117                 return name
 118         }
 119         return fmt.Sprintf("%s (%.3fs)", name, e.Finished.Sub(*e.Started).Seconds())
 120 }
 121
 122 func (e RunError) Error() string {
 123         return fmt.Sprintf("%s: %s", e.Name(), e.Err)
 124 }
 125
 126 func mkdirs(pth string) error {
 127         if _, err := os.Stat(pth); err == nil {
 128                 return nil
 129         }
 130         return os.MkdirAll(pth, os.FileMode(0777))
 131 }
 132
 133 func isModified(cwd, redoDir, tgt string) (bool, *Inode, string, error) {
 134         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 135         if err != nil {
 136                 if os.IsNotExist(err) {
 137                         return false, nil, "", nil
 138                 }
 139                 return false, nil, "", err
 140         }
 141         defer fdDep.Close()
 142         r := recfile.NewReader(fdDep)
 143         var modified bool
 144         var ourInode *Inode
 145         var hshPrev string
 146         for {
 147                 m, err := r.NextMap()
 148                 if err != nil {
 149                         if errors.Is(err, io.EOF) {
 150                                 break
 151                         }
 152                         return false, nil, "", err
 153                 }
 154                 if m["Type"] != DepTypeIfchange || m["Target"] != tgt {
 155                         continue
 156                 }
 157                 fd, err := os.Open(path.Join(cwd, tgt))
 158                 if err != nil {
 159                         if os.IsNotExist(err) {
 160                                 return false, nil, "", nil
 161                         }
 162                         return false, nil, "", err
 163                 }
 164                 ourInode, err = inodeFromFile(fd)
 165                 fd.Close()
 166                 if err != nil {
 167                         return false, nil, "", err
 168                 }
 169                 theirInode, err := inodeFromRec(m)
 170                 if err != nil {
 171                         return false, nil, "", err
 172                 }
 173                 hshPrev = m["Hash"]
 174                 modified = !ourInode.Equals(theirInode)
 175                 break
 176         }
 177         return modified, ourInode, hshPrev, nil
 178 }
 179
 180 func syncDir(dir string) error {
 181         fd, err := os.Open(dir)
 182         if err != nil {
 183                 return err
 184         }
 185         err = fd.Sync()
 186         fd.Close()
 187         return err
 188 }
 189
 190 func runScript(tgtOrig string, errs chan error, traced bool) error {
 191         cwd, tgt := cwdAndTgt(tgtOrig)
 192         redoDir := path.Join(cwd, RedoDir)
 193         if err := mkdirs(redoDir); err != nil {
 194                 return TgtError{tgtOrig, err}
 195         }
 196
 197         // Acquire lock
 198         fdLock, err := os.OpenFile(
 199                 path.Join(redoDir, tgt+LockSuffix),
 200                 os.O_WRONLY|os.O_TRUNC|os.O_CREATE,
 201                 os.FileMode(0666),
 202         )
 203         if err != nil {
 204                 return TgtError{tgtOrig, err}
 205         }
 206         flock := unix.Flock_t{
 207                 Type:   unix.F_WRLCK,
 208                 Whence: io.SeekStart,
 209         }
 210         lockRelease := func() {
 211                 tracef(CLock, "LOCK_UN: %s", fdLock.Name())
 212                 flock.Type = unix.F_UNLCK
 213                 if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 214                         log.Fatalln(err)
 215                 }
 216                 fdLock.Close()
 217         }
 218         tracef(CLock, "LOCK_NB: %s", fdLock.Name())
 219
 220         // Waiting for job completion, already taken by someone else
 221         if err = unix.FcntlFlock(fdLock.Fd(), unix.F_SETLK, &flock); err != nil {
 222                 if uintptr(err.(syscall.Errno)) != uintptr(unix.EAGAIN) {
 223                         fdLock.Close()
 224                         return TgtError{tgtOrig, err}
 225                 }
 226                 Jobs.Add(1)
 227                 if err = unix.FcntlFlock(fdLock.Fd(), unix.F_GETLK, &flock); err != nil {
 228                         log.Fatalln(err)
 229                 }
 230                 tracef(CDebug, "waiting: %s (pid=%d)", tgtOrig, flock.Pid)
 231                 if FdStatus != nil {
 232                         if _, err = FdStatus.Write([]byte{StatusWait}); err != nil {
 233                                 log.Fatalln(err)
 234                         }
 235                 }
 236                 go func() {
 237                         defer Jobs.Done()
 238                         tracef(CLock, "LOCK_EX: %s", fdLock.Name())
 239                         if err := unix.FcntlFlock(fdLock.Fd(), unix.F_SETLKW, &flock); err != nil {
 240                                 log.Fatalln(err)
 241                         }
 242                         lockRelease()
 243                         tracef(CDebug, "waiting done: %s", tgtOrig)
 244                         if FdStatus != nil {
 245                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 246                                         log.Fatalln(err)
 247                                 }
 248                         }
 249                         var depInfo *DepInfo
 250                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 251                         if err != nil {
 252                                 if os.IsNotExist(err) {
 253                                         err = errors.New("was not built: no .rec")
 254                                 }
 255                                 goto Finish
 256                         }
 257                         defer fdDep.Close()
 258                         depInfo, err = depRead(fdDep)
 259                         if err != nil {
 260                                 goto Finish
 261                         }
 262                         if depInfo.build != BuildUUID {
 263                                 err = errors.New("was not built: build differs")
 264                         }
 265                 Finish:
 266                         if err != nil {
 267                                 err = TgtError{tgtOrig, err}
 268                                 fdLock.Close()
 269                         }
 270                         errs <- err
 271                 }()
 272                 return nil
 273         }
 274
 275         // Check if target is not modified externally
 276         modified, inodePrev, hshPrev, err := isModified(cwd, redoDir, tgt)
 277         if err != nil {
 278                 lockRelease()
 279                 return TgtError{tgtOrig, err}
 280         }
 281         if modified {
 282                 lockRelease()
 283                 if StopIfMod {
 284                         return fmt.Errorf("%s externally modified", tgtOrig)
 285                 }
 286                 tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 287                 go func() {
 288                         errs <- nil
 289                 }()
 290                 return nil
 291         }
 292
 293         // Start preparing .rec
 294         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 295         if err != nil {
 296                 lockRelease()
 297                 return TgtError{tgtOrig, err}
 298         }
 299         fdDepPath := fdDep.Name()
 300         cleanup := func() {
 301                 lockRelease()
 302                 fdDep.Close()
 303                 os.Remove(fdDep.Name())
 304         }
 305         if _, err = recfile.NewWriter(fdDep).WriteFields(
 306                 recfile.Field{Name: "Build", Value: BuildUUID},
 307         ); err != nil {
 308                 cleanup()
 309                 return TgtError{tgtOrig, err}
 310         }
 311
 312         // Find .do
 313         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 314         if err != nil {
 315                 cleanup()
 316                 return TgtError{tgtOrig, err}
 317         }
 318         if doFile == "" {
 319                 cleanup()
 320                 return TgtError{tgtOrig, errors.New("no .do found")}
 321         }
 322
 323         // Determine basename and DIRPREFIX
 324         doFileRelPath := doFile
 325         ents := strings.Split(cwd, "/")
 326         ents = ents[len(ents)-upLevels:]
 327         dirPrefix := path.Join(ents...)
 328         cwdOrig := cwd
 329         for i := 0; i < upLevels; i++ {
 330                 cwd = path.Join(cwd, "..")
 331                 doFileRelPath = path.Join("..", doFileRelPath)
 332         }
 333         cwd = path.Clean(cwd)
 334         doFilePath := path.Join(cwd, doFile)
 335         basename := tgt
 336         runErr := RunError{Tgt: tgtOrig}
 337         if strings.HasPrefix(doFile, "default.") {
 338                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 339                 runErr.DoFile = doFileRelPath
 340         }
 341
 342         if err = depWrite(fdDep, cwdOrig, doFileRelPath, ""); err != nil {
 343                 cleanup()
 344                 return TgtError{tgtOrig, err}
 345         }
 346         fdDep.Close()
 347         tracef(CWait, "%s", runErr.Name())
 348
 349         // Prepare command line
 350         var cmdName string
 351         var args []string
 352         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 353                 cmdName = doFilePath
 354                 args = make([]string, 0, 3)
 355         } else {
 356                 cmdName = "/bin/sh"
 357                 if traced || TracedAll {
 358                         args = append(args, "-ex")
 359                 } else {
 360                         args = append(args, "-e")
 361                 }
 362                 args = append(args, doFile)
 363         }
 364
 365         // Temporary file for stdout
 366         fdStdout, err := tempfile(cwdOrig, tgt)
 367         if err != nil {
 368                 cleanup()
 369                 return TgtError{tgtOrig, err}
 370         }
 371         stdoutPath := fdStdout.Name()
 372         fdStdout.Close()
 373         tmpPath := stdoutPath + ".3" // and for $3
 374         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 375         if err != nil {
 376                 panic(err)
 377         }
 378         args = append(
 379                 args,
 380                 path.Join(dirPrefix, tgt),
 381                 path.Join(dirPrefix, basename),
 382                 tmpPathRel,
 383         )
 384
 385         cmd := exec.Command(cmdName, args...)
 386         cmd.Dir = cwd
 387         // cmd.Stdin reads from /dev/null by default
 388         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 389         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 390         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 391
 392         childStderrPrefix := tempsuffix()
 393         cmd.Env = append(cmd.Env, fmt.Sprintf(
 394                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 395         ))
 396
 397         fdNum := 0
 398         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 399         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 400         fdNum++
 401         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 402         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 403         fdNum++
 404
 405         if FdStatus == nil {
 406                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 407         } else {
 408                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 409                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 410                 fdNum++
 411         }
 412
 413         // Preparing stderr
 414         var fdStderr *os.File
 415         if StderrKeep {
 416                 fdStderr, err = os.OpenFile(
 417                         path.Join(redoDir, tgt+LogSuffix),
 418                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 419                         os.FileMode(0666),
 420                 )
 421                 if err != nil {
 422                         cleanup()
 423                         return TgtError{tgtOrig, err}
 424                 }
 425         }
 426         shCtx := fmt.Sprintf(
 427                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 428                 tgtOrig, cmdName, args, cwd, dirPrefix,
 429         )
 430         tracef(CDebug, "%s", shCtx)
 431
 432         Jobs.Add(1)
 433         go func() {
 434                 jsToken := jsAcquire(shCtx)
 435                 if JSR == nil {
 436                         // infinite jobs
 437                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 438                 } else {
 439                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 440                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 441                         makeFlags := fmt.Sprintf(
 442                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 443                         )
 444                         makeFlags = strings.Trim(makeFlags, " ")
 445                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 446                         fdNum += 2
 447                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 448                 }
 449
 450                 if FdStatus != nil {
 451                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 452                                 log.Fatalln(err)
 453                         }
 454                 }
 455
 456                 var finished time.Time
 457                 var exitErr *exec.ExitError
 458                 started := time.Now()
 459                 runErr.Started = &started
 460                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 461                 if err != nil {
 462                         if fdStderr != nil {
 463                                 fdStderr.Close()
 464                         }
 465                         runErr.Err = err
 466                         errs <- runErr
 467                         return
 468                 }
 469                 cmd.Stdout = fdStdout
 470                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 471                 if err != nil {
 472                         if fdStderr != nil {
 473                                 fdStderr.Close()
 474                         }
 475                         fdStdout.Close()
 476                         runErr.Err = err
 477                         errs <- runErr
 478                         return
 479                 }
 480                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 481                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 482                 fdNum++
 483                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 484
 485                 defer func() {
 486                         jsRelease(shCtx, jsToken)
 487                         fdDep.Close()
 488                         fdStdout.Close()
 489                         if fdStderr != nil {
 490                                 fdStderr.Close()
 491                                 logRecPath := path.Join(redoDir, tgt+LogRecSuffix)
 492                                 if fdStderr, err = os.OpenFile(
 493                                         logRecPath,
 494                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 495                                         os.FileMode(0666),
 496                                 ); err == nil {
 497                                         fields := []recfile.Field{
 498                                                 {Name: "Build", Value: BuildUUID},
 499                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 500                                                 {Name: "Cwd", Value: cwd},
 501                                         }
 502                                         if cmd.Process != nil {
 503                                                 fields = append(fields, recfile.Field{
 504                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 505                                                 })
 506                                         }
 507                                         ts := new(tai64n.TAI64N)
 508                                         ts.FromTime(started)
 509                                         fields = append(fields,
 510                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 511                                         )
 512                                         ts.FromTime(finished)
 513                                         fields = append(fields,
 514                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 515                                         fields = append(fields, recfile.Field{
 516                                                 Name:  "Duration",
 517                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 518                                         })
 519                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 520                                         for _, arg := range args {
 521                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 522                                         }
 523                                         for _, env := range cmd.Env {
 524                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 525                                         }
 526                                         if exitErr != nil {
 527                                                 fields = append(fields, recfile.Field{
 528                                                         Name:  "ExitCode",
 529                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 530                                                 })
 531                                         }
 532                                         w := bufio.NewWriter(fdStderr)
 533
 534                                         var depInfo *DepInfo
 535                                         fdDep, err := os.Open(fdDepPath)
 536                                         if err != nil {
 537                                                 goto Err
 538                                         }
 539                                         depInfo, err = depRead(fdDep)
 540                                         fdDep.Close()
 541                                         if err != nil {
 542                                                 goto Err
 543                                         }
 544                                         for _, dep := range depInfo.ifchanges {
 545                                                 fields = append(fields, recfile.Field{
 546                                                         Name:  "Ifchange",
 547                                                         Value: dep["Target"],
 548                                                 })
 549                                         }
 550                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 551                                         if err != nil {
 552                                                 goto Err
 553                                         }
 554                                         err = w.Flush()
 555                                 Err:
 556                                         if err != nil {
 557                                                 log.Println(err)
 558                                                 os.Remove(logRecPath)
 559                                         }
 560                                         fdStderr.Close()
 561                                 } else {
 562                                         log.Println("can not open", logRecPath, ":", err)
 563                                 }
 564                         }
 565                         lockRelease()
 566                         os.Remove(fdDep.Name())
 567                         os.Remove(fdStdout.Name())
 568                         os.Remove(tmpPath)
 569                         os.Remove(fdLock.Name())
 570                         if FdStatus != nil {
 571                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 572                                         log.Fatalln(err)
 573                                 }
 574                         }
 575                         Jobs.Done()
 576                 }()
 577                 stderr, err := cmd.StderrPipe()
 578                 if err != nil {
 579                         runErr.Err = err
 580                         errs <- runErr
 581                         return
 582                 }
 583                 started = time.Now()
 584                 err = cmd.Start()
 585                 if err != nil {
 586                         runErr.Err = err
 587                         errs <- runErr
 588                         return
 589                 }
 590                 RunningProcsM.Lock()
 591                 RunningProcs[cmd.Process.Pid] = cmd.Process
 592                 RunningProcsM.Unlock()
 593                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 594                 tracef(CDebug, "%s runs %s", tgtOrig, pid)
 595
 596                 stderrTerm := make(chan struct{})
 597                 go func() {
 598                         scanner := bufio.NewScanner(stderr)
 599                         var line string
 600                         ts := new(tai64n.TAI64N)
 601                         for scanner.Scan() {
 602                                 line = scanner.Text()
 603                                 if strings.HasPrefix(line, childStderrPrefix) {
 604                                         line = line[len(childStderrPrefix):]
 605                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 606                                         continue
 607                                 }
 608                                 if fdStderr != nil {
 609                                         ts.FromTime(time.Now())
 610                                         LogMutex.Lock()
 611                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 612                                         LogMutex.Unlock()
 613                                 }
 614                                 if StderrSilent {
 615                                         continue
 616                                 }
 617                                 if MyPid == 0 {
 618                                         tracef(CNone, "%s", line)
 619                                 } else {
 620                                         tracef(CNone, "%s %s", pid, line)
 621                                 }
 622                         }
 623                         close(stderrTerm)
 624                 }()
 625
 626                 // Wait for job completion
 627                 <-stderrTerm
 628                 err = cmd.Wait()
 629                 RunningProcsM.Lock()
 630                 delete(RunningProcs, cmd.Process.Pid)
 631                 RunningProcsM.Unlock()
 632                 finished = time.Now()
 633                 runErr.Finished = &finished
 634                 if err != nil {
 635                         exitErr = err.(*exec.ExitError)
 636                         runErr.Err = err
 637                         errs <- runErr
 638                         return
 639                 }
 640
 641                 // Was $1 touched?
 642                 if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 643                         if inodePrev == nil {
 644                                 fd.Close()
 645                                 runErr.Err = Err1WasTouched
 646                                 errs <- runErr
 647                                 return
 648                         }
 649                         inode, err := inodeFromFile(fd)
 650                         fd.Close()
 651                         if err != nil {
 652                                 runErr.Err = err
 653                                 errs <- runErr
 654                                 return
 655                         }
 656                         if !inode.Equals(inodePrev) {
 657                                 runErr.Err = Err1WasTouched
 658                                 errs <- runErr
 659                                 return
 660                         }
 661                 }
 662
 663                 if inodePrev != nil {
 664                         if fd, err := os.Open(path.Join(cwdOrig, tgt)); err == nil {
 665                                 inode, err := inodeFromFile(fd)
 666                                 fd.Close()
 667                                 if err == nil && !inode.Equals(inodePrev) {
 668                                         runErr.Err = Err1WasTouched
 669                                         errs <- runErr
 670                                         return
 671                                 }
 672                         }
 673                 }
 674
 675                 // Does it produce both stdout and tmp?
 676                 fiStdout, err := os.Stat(fdStdout.Name())
 677                 if err != nil {
 678                         runErr.Err = err
 679                         errs <- runErr
 680                         return
 681                 }
 682                 tmpExists := false
 683                 _, err = os.Stat(tmpPath)
 684                 if err == nil {
 685                         if fiStdout.Size() > 0 {
 686                                 runErr.Err = errors.New("created both tmp and stdout")
 687                                 errs <- runErr
 688                                 return
 689                         }
 690                         tmpExists = true
 691                 } else if !os.IsNotExist(err) {
 692                         runErr.Err = err
 693                         errs <- runErr
 694                         return
 695                 }
 696
 697                 // Determine what file we must process at last
 698                 var fd *os.File
 699                 if tmpExists {
 700                         fd, err = os.Open(tmpPath)
 701                         if err != nil {
 702                                 goto Finish
 703                         }
 704                         defer fd.Close()
 705                 } else if fiStdout.Size() > 0 {
 706                         fd = fdStdout
 707                 }
 708
 709                 // Do we need to ifcreate it, or ifchange with renaming?
 710                 if fd == nil {
 711                         os.Remove(path.Join(cwdOrig, tgt))
 712                         err = ifcreate(fdDep, tgt)
 713                         if err != nil {
 714                                 goto Finish
 715                         }
 716                 } else {
 717                         var hsh string
 718                         if hshPrev != "" {
 719                                 _, err = fd.Seek(0, io.SeekStart)
 720                                 if err != nil {
 721                                         goto Finish
 722                                 }
 723                                 hsh, err = fileHash(fd)
 724                                 if err != nil {
 725                                         goto Finish
 726                                 }
 727                                 if hsh == hshPrev {
 728                                         tracef(CDebug, "%s has same hash, not renaming", tgtOrig)
 729                                         err = os.Remove(fd.Name())
 730                                         if err != nil {
 731                                                 goto Finish
 732                                         }
 733                                         err = os.Chtimes(path.Join(cwdOrig, tgt), finished, finished)
 734                                         if err != nil {
 735                                                 goto Finish
 736                                         }
 737                                         if !NoSync {
 738                                                 err = syncDir(cwdOrig)
 739                                                 if err != nil {
 740                                                         goto Finish
 741                                                 }
 742                                         }
 743                                         err = depWrite(fdDep, cwdOrig, tgt, hshPrev)
 744                                         if err != nil {
 745                                                 goto Finish
 746                                         }
 747                                         goto RecCommit
 748                                 }
 749                         }
 750                         if !NoSync {
 751                                 err = fd.Sync()
 752                                 if err != nil {
 753                                         goto Finish
 754                                 }
 755                         }
 756                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 757                         if err != nil {
 758                                 goto Finish
 759                         }
 760                         if !NoSync {
 761                                 err = syncDir(cwdOrig)
 762                                 if err != nil {
 763                                         goto Finish
 764                                 }
 765                         }
 766                         err = depWrite(fdDep, cwdOrig, tgt, hsh)
 767                         if err != nil {
 768                                 goto Finish
 769                         }
 770                 }
 771
 772         RecCommit:
 773                 // Commit .rec
 774                 if !NoSync {
 775                         err = fdDep.Sync()
 776                         if err != nil {
 777                                 goto Finish
 778                         }
 779                 }
 780                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 781                 err = os.Rename(fdDep.Name(), fdDepPath)
 782                 if err != nil {
 783                         goto Finish
 784                 }
 785                 if !NoSync {
 786                         err = syncDir(redoDir)
 787                         if err != nil {
 788                                 goto Finish
 789                         }
 790                 }
 791
 792                 // Post-commit .rec sanitizing
 793                 fdDep.Close()
 794                 if fdDepR, err := os.Open(fdDepPath); err == nil {
 795                         depInfo, err := depRead(fdDepR)
 796                         fdDepR.Close()
 797                         if err != nil {
 798                                 goto Finish
 799                         }
 800                         ifchangeSeen := make(map[string]struct{}, len(depInfo.ifchanges))
 801                         for _, dep := range depInfo.ifchanges {
 802                                 ifchangeSeen[dep["Target"]] = struct{}{}
 803                         }
 804                         for _, dep := range depInfo.ifcreates {
 805                                 if _, exists := ifchangeSeen[dep]; exists {
 806                                         tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
 807                                 }
 808                         }
 809                 }
 810
 811         Finish:
 812                 runErr.Err = err
 813                 errs <- runErr
 814         }()
 815         return nil
 816 }
 817
 818 func isOkRun(err error) bool {
 819         if err == nil {
 820                 return true
 821         }
 822         var runErr RunError
 823         if errors.As(err, &runErr) && runErr.Err == nil {
 824                 tracef(CRedo, "%s", runErr.Name())
 825                 return true
 826         }
 827         tracef(CErr, "%s", err)
 828         return false
 829 }