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, forced, 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.Fatal(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                                 if errors.Is(err, unix.EDEADLK) {
 248                                         time.Sleep(10 * time.Millisecond)
 249                                         goto LockAgain
 250                                 }
 251                                 log.Fatalln(err, fdLock.Name())
 252                         }
 253                         lockRelease()
 254                         tracef(CDebug, "waiting done: %s", tgtOrig)
 255                         if FdStatus != nil {
 256                                 if _, err = FdStatus.Write([]byte{StatusWaited}); err != nil {
 257                                         log.Fatal(err)
 258                                 }
 259                         }
 260                         var depInfo *DepInfo
 261                         fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix))
 262                         if err != nil {
 263                                 if os.IsNotExist(err) {
 264                                         err = errors.New("was not built: no .rec")
 265                                 }
 266                                 goto Finish
 267                         }
 268                         defer fdDep.Close()
 269                         depInfo, err = depRead(fdDep)
 270                         if err != nil {
 271                                 goto Finish
 272                         }
 273                         if depInfo.build != BuildUUID {
 274                                 err = errors.New("was not built: build differs")
 275                         }
 276                 Finish:
 277                         if err != nil {
 278                                 err = TgtError{tgtOrig, err}
 279                                 fdLock.Close()
 280                         }
 281                         errs <- err
 282                 }()
 283                 return nil
 284         }
 285
 286         // Check if it was already built in parallel
 287         if !forced {
 288                 if fdDep, err := os.Open(path.Join(redoDir, tgt+DepSuffix)); err == nil {
 289                         depInfo, err := depRead(fdDep)
 290                         fdDep.Close()
 291                         if err == nil && depInfo.build == BuildUUID {
 292                                 lockRelease()
 293                                 errs <- nil
 294                                 return nil
 295                         }
 296                 }
 297         }
 298
 299         // Check if target is not modified externally
 300         modified, inodePrev, hshPrev, err := isModified(cwd, redoDir, tgt)
 301         if err != nil {
 302                 lockRelease()
 303                 return TgtError{tgtOrig, err}
 304         }
 305         if modified {
 306                 lockRelease()
 307                 if StopIfMod {
 308                         return fmt.Errorf("%s externally modified", tgtOrig)
 309                 }
 310                 tracef(CWarn, "%s externally modified: not redoing", tgtOrig)
 311                 go func() {
 312                         errs <- nil
 313                 }()
 314                 return nil
 315         }
 316
 317         // Start preparing .rec
 318         fdDep, err := tempfile(redoDir, tgt+DepSuffix)
 319         if err != nil {
 320                 lockRelease()
 321                 return TgtError{tgtOrig, err}
 322         }
 323         fdDepPath := fdDep.Name()
 324         cleanup := func() {
 325                 lockRelease()
 326                 fdDep.Close()
 327                 os.Remove(fdDep.Name())
 328         }
 329         if _, err = recfile.NewWriter(fdDep).WriteFields(
 330                 recfile.Field{Name: "Build", Value: BuildUUID},
 331         ); err != nil {
 332                 cleanup()
 333                 return TgtError{tgtOrig, err}
 334         }
 335
 336         // Find .do
 337         doFile, upLevels, err := findDo(fdDep, cwd, tgt)
 338         if err != nil {
 339                 cleanup()
 340                 return TgtError{tgtOrig, err}
 341         }
 342         if doFile == "" {
 343                 cleanup()
 344                 return TgtError{tgtOrig, errors.New("no .do found")}
 345         }
 346
 347         // Determine basename and DIRPREFIX
 348         doFileRelPath := doFile
 349         ents := strings.Split(cwd, "/")
 350         ents = ents[len(ents)-upLevels:]
 351         dirPrefix := path.Join(ents...)
 352         cwdOrig := cwd
 353         for i := 0; i < upLevels; i++ {
 354                 cwd = path.Join(cwd, "..")
 355                 doFileRelPath = path.Join("..", doFileRelPath)
 356         }
 357         cwd = path.Clean(cwd)
 358         doFilePath := path.Join(cwd, doFile)
 359         basename := tgt
 360         runErr := RunError{Tgt: tgtOrig}
 361         if strings.HasPrefix(doFile, "default.") {
 362                 basename = tgt[:len(tgt)-(len(doFile)-len("default.")-len(".do"))-1]
 363                 runErr.DoFile = doFileRelPath
 364         }
 365
 366         if err = depWrite(fdDep, cwdOrig, doFileRelPath, ""); err != nil {
 367                 cleanup()
 368                 return TgtError{tgtOrig, err}
 369         }
 370         fdDep.Close()
 371         tracef(CWait, "%s", runErr.Name())
 372
 373         // Prepare command line
 374         var cmdName string
 375         var args []string
 376         if err = unix.Access(doFilePath, unix.X_OK); err == nil {
 377                 cmdName = doFilePath
 378                 args = make([]string, 0, 3)
 379         } else {
 380                 cmdName = "/bin/sh"
 381                 if traced || TracedAll {
 382                         args = append(args, "-ex")
 383                 } else {
 384                         args = append(args, "-e")
 385                 }
 386                 args = append(args, doFile)
 387         }
 388
 389         // Temporary file for stdout
 390         fdStdout, err := tempfile(cwdOrig, tgt)
 391         if err != nil {
 392                 cleanup()
 393                 return TgtError{tgtOrig, err}
 394         }
 395         stdoutPath := fdStdout.Name()
 396         fdStdout.Close()
 397         tmpPath := stdoutPath + ".3" // and for $3
 398         tmpPathRel, err := filepath.Rel(cwd, tmpPath)
 399         if err != nil {
 400                 panic(err)
 401         }
 402         args = append(
 403                 args,
 404                 path.Join(dirPrefix, tgt),
 405                 path.Join(dirPrefix, basename),
 406                 tmpPathRel,
 407         )
 408         shCtx = fmt.Sprintf(
 409                 "sh: %s: %s %s cwd:%s dirprefix:%s",
 410                 tgtOrig, cmdName, args, cwd, dirPrefix,
 411         )
 412
 413         cmd := exec.Command(cmdName, args...)
 414         cmd.Dir = cwd
 415         // cmd.Stdin reads from /dev/null by default
 416         cmd.Env = append(os.Environ(), fmt.Sprintf("%s=%d", EnvLevel, Level+1))
 417         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDirPrefix, dirPrefix))
 418         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvBuildUUID, BuildUUID))
 419
 420         childStderrPrefixRaw := make([]byte, 8)
 421         if _, err = io.ReadFull(rand.Reader, childStderrPrefixRaw); err != nil {
 422                 panic(err)
 423         }
 424         childStderrPrefix := hex.EncodeToString(childStderrPrefixRaw)
 425         cmd.Env = append(cmd.Env, fmt.Sprintf(
 426                 "%s=%s", EnvStderrPrefix, childStderrPrefix,
 427         ))
 428
 429         fdNum := 0
 430         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgts)
 431         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsFd, 3+fdNum))
 432         fdNum++
 433         cmd.ExtraFiles = append(cmd.ExtraFiles, FdOODTgtsLock)
 434         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvOODTgtsLockFd, 3+fdNum))
 435         fdNum++
 436
 437         if FdStatus == nil {
 438                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvStatusFd))
 439         } else {
 440                 cmd.ExtraFiles = append(cmd.ExtraFiles, FdStatus)
 441                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvStatusFd, 3+fdNum))
 442                 fdNum++
 443         }
 444
 445         // Preparing stderr
 446         var fdStderr *os.File
 447         if StderrKeep {
 448                 fdStderr, err = os.OpenFile(
 449                         path.Join(redoDir, tgt+LogSuffix),
 450                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 451                         os.FileMode(0666),
 452                 )
 453                 if err != nil {
 454                         cleanup()
 455                         return TgtError{tgtOrig, err}
 456                 }
 457         }
 458         tracef(CDebug, "%s", shCtx)
 459
 460         jsNeedsRelease = false
 461         Jobs.Add(1)
 462         go func() {
 463                 if JSR == nil {
 464                         // infinite jobs
 465                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=NO", EnvJobs))
 466                 } else {
 467                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSR)
 468                         cmd.ExtraFiles = append(cmd.ExtraFiles, JSW)
 469                         makeFlags := fmt.Sprintf(
 470                                 "%s %s%d,%d", MakeFlags, MakeJSArg, 3+fdNum+0, 3+fdNum+1,
 471                         )
 472                         makeFlags = strings.Trim(makeFlags, " ")
 473                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", MakeFlagsName, makeFlags))
 474                         fdNum += 2
 475                         cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvJSToken, jsToken))
 476                 }
 477
 478                 if FdStatus != nil {
 479                         if _, err = FdStatus.Write([]byte{StatusRun}); err != nil {
 480                                 log.Fatal(err)
 481                         }
 482                 }
 483
 484                 defer jsRelease(shCtx, jsToken)
 485
 486                 var finished time.Time
 487                 var exitErr *exec.ExitError
 488                 started := time.Now()
 489                 runErr.Started = &started
 490                 fdStdout, err = os.OpenFile(stdoutPath, os.O_RDWR, os.FileMode(0666))
 491                 if err != nil {
 492                         if fdStderr != nil {
 493                                 fdStderr.Close()
 494                         }
 495                         runErr.Err = err
 496                         errs <- runErr
 497                         return
 498                 }
 499                 cmd.Stdout = fdStdout
 500                 fdDep, err = os.OpenFile(fdDepPath, os.O_WRONLY|os.O_APPEND, os.FileMode(0666))
 501                 if err != nil {
 502                         if fdStderr != nil {
 503                                 fdStderr.Close()
 504                         }
 505                         fdStdout.Close()
 506                         runErr.Err = err
 507                         errs <- runErr
 508                         return
 509                 }
 510                 cmd.ExtraFiles = append(cmd.ExtraFiles, fdDep)
 511                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%d", EnvDepFd, 3+fdNum))
 512                 fdNum++
 513                 cmd.Env = append(cmd.Env, fmt.Sprintf("%s=%s", EnvDepCwd, cwd))
 514
 515                 defer func() {
 516                         fdDep.Close()
 517                         fdStdout.Close()
 518                         if fdStderr != nil {
 519                                 fdStderr.Close()
 520                                 logRecPath := path.Join(redoDir, tgt+LogRecSuffix)
 521                                 if fdStderr, err = os.OpenFile(
 522                                         logRecPath,
 523                                         os.O_WRONLY|os.O_CREATE|os.O_TRUNC,
 524                                         os.FileMode(0666),
 525                                 ); err == nil {
 526                                         fields := []recfile.Field{
 527                                                 {Name: "Build", Value: BuildUUID},
 528                                                 {Name: "PPID", Value: strconv.Itoa(os.Getpid())},
 529                                                 {Name: "Cwd", Value: cwd},
 530                                         }
 531                                         if cmd.Process != nil {
 532                                                 fields = append(fields, recfile.Field{
 533                                                         Name: "PID", Value: strconv.Itoa(cmd.Process.Pid),
 534                                                 })
 535                                         }
 536                                         ts := new(tai64n.TAI64N)
 537                                         ts.FromTime(started)
 538                                         fields = append(fields,
 539                                                 recfile.Field{Name: "Started", Value: tai64n.Encode(ts[:])},
 540                                         )
 541                                         ts.FromTime(finished)
 542                                         fields = append(fields,
 543                                                 recfile.Field{Name: "Finished", Value: tai64n.Encode(ts[:])})
 544                                         fields = append(fields, recfile.Field{
 545                                                 Name:  "Duration",
 546                                                 Value: strconv.FormatInt(finished.Sub(started).Nanoseconds(), 10),
 547                                         })
 548                                         fields = append(fields, recfile.Field{Name: "Cmd", Value: cmdName})
 549                                         for _, arg := range args {
 550                                                 fields = append(fields, recfile.Field{Name: "Arg", Value: arg})
 551                                         }
 552                                         for _, env := range cmd.Env {
 553                                                 fields = append(fields, recfile.Field{Name: "Env", Value: env})
 554                                         }
 555                                         if exitErr != nil {
 556                                                 fields = append(fields, recfile.Field{
 557                                                         Name:  "ExitCode",
 558                                                         Value: strconv.Itoa(exitErr.ProcessState.ExitCode()),
 559                                                 })
 560                                         }
 561                                         w := bufio.NewWriter(fdStderr)
 562
 563                                         var depInfo *DepInfo
 564                                         fdDep, err := os.Open(fdDepPath)
 565                                         if err != nil {
 566                                                 goto Err
 567                                         }
 568                                         depInfo, err = depRead(fdDep)
 569                                         fdDep.Close()
 570                                         if err != nil {
 571                                                 goto Err
 572                                         }
 573                                         for _, dep := range depInfo.ifchanges {
 574                                                 fields = append(fields, recfile.Field{
 575                                                         Name:  "Ifchange",
 576                                                         Value: dep["Target"],
 577                                                 })
 578                                         }
 579                                         _, err = recfile.NewWriter(w).WriteFields(fields...)
 580                                         if err != nil {
 581                                                 goto Err
 582                                         }
 583                                         err = w.Flush()
 584                                 Err:
 585                                         if err != nil {
 586                                                 log.Print(err)
 587                                                 os.Remove(logRecPath)
 588                                         }
 589                                         fdStderr.Close()
 590                                 } else {
 591                                         log.Println("can not open", logRecPath, ":", err)
 592                                 }
 593                         }
 594                         lockRelease()
 595                         os.Remove(fdDep.Name())
 596                         os.Remove(fdStdout.Name())
 597                         os.Remove(tmpPath)
 598                         if FdStatus != nil {
 599                                 if _, err = FdStatus.Write([]byte{StatusDone}); err != nil {
 600                                         log.Fatal(err)
 601                                 }
 602                         }
 603                         Jobs.Done()
 604                 }()
 605                 stderr, err := cmd.StderrPipe()
 606                 if err != nil {
 607                         runErr.Err = err
 608                         errs <- runErr
 609                         return
 610                 }
 611                 started = time.Now()
 612                 err = cmd.Start()
 613                 if err != nil {
 614                         runErr.Err = err
 615                         errs <- runErr
 616                         return
 617                 }
 618                 RunningProcsM.Lock()
 619                 RunningProcs[cmd.Process.Pid] = cmd.Process
 620                 RunningProcsM.Unlock()
 621                 pid := fmt.Sprintf("[%d]", cmd.Process.Pid)
 622                 tracef(CDebug, "%s runs %s", tgtOrig, pid)
 623
 624                 stderrTerm := make(chan struct{})
 625                 go func() {
 626                         scanner := bufio.NewScanner(stderr)
 627                         var line string
 628                         ts := new(tai64n.TAI64N)
 629                         for scanner.Scan() {
 630                                 line = scanner.Text()
 631                                 if strings.HasPrefix(line, childStderrPrefix) {
 632                                         line = line[len(childStderrPrefix):]
 633                                         os.Stderr.WriteString(StderrPrefix + line + "\n")
 634                                         continue
 635                                 }
 636                                 if fdStderr != nil {
 637                                         ts.FromTime(time.Now())
 638                                         LogMutex.Lock()
 639                                         fmt.Fprintln(fdStderr, tai64n.Encode(ts[:]), line)
 640                                         LogMutex.Unlock()
 641                                 }
 642                                 if StderrSilent {
 643                                         continue
 644                                 }
 645                                 if MyPid == 0 {
 646                                         tracef(CNone, "%s", line)
 647                                 } else {
 648                                         tracef(CNone, "%s %s", pid, line)
 649                                 }
 650                         }
 651                         close(stderrTerm)
 652                 }()
 653
 654                 // Wait for job completion
 655                 <-stderrTerm
 656                 err = cmd.Wait()
 657                 RunningProcsM.Lock()
 658                 delete(RunningProcs, cmd.Process.Pid)
 659                 RunningProcsM.Unlock()
 660                 finished = time.Now()
 661                 runErr.Finished = &finished
 662                 if err != nil {
 663                         exitErr = err.(*exec.ExitError)
 664                         runErr.Err = err
 665                         errs <- runErr
 666                         return
 667                 }
 668
 669                 // Was $1 touched?
 670                 if inode, err := inodeFromFileByPath(path.Join(cwdOrig, tgt)); err == nil {
 671                         if inodePrev == nil {
 672                                 runErr.Err = Err1WasTouched
 673                                 errs <- runErr
 674                                 return
 675                         }
 676                         if err != nil {
 677                                 runErr.Err = err
 678                                 errs <- runErr
 679                                 return
 680                         }
 681                         if !inode.Equals(inodePrev) {
 682                                 runErr.Err = Err1WasTouched
 683                                 errs <- runErr
 684                                 return
 685                         }
 686                 }
 687
 688                 if inodePrev != nil {
 689                         if inode, err := inodeFromFileByPath(path.Join(cwdOrig, tgt)); err == nil {
 690                                 if !inode.Equals(inodePrev) {
 691                                         runErr.Err = Err1WasTouched
 692                                         errs <- runErr
 693                                         return
 694                                 }
 695                         }
 696                 }
 697
 698                 // Does it produce both stdout and tmp?
 699                 fiStdout, err := os.Stat(fdStdout.Name())
 700                 if err != nil {
 701                         runErr.Err = err
 702                         errs <- runErr
 703                         return
 704                 }
 705                 tmpExists := false
 706                 _, err = os.Stat(tmpPath)
 707                 if err == nil {
 708                         if fiStdout.Size() > 0 {
 709                                 runErr.Err = errors.New("created both tmp and stdout")
 710                                 errs <- runErr
 711                                 return
 712                         }
 713                         tmpExists = true
 714                 } else if !os.IsNotExist(err) {
 715                         runErr.Err = err
 716                         errs <- runErr
 717                         return
 718                 }
 719
 720                 // Determine what file we must process at last
 721                 var fd *os.File
 722                 if tmpExists {
 723                         fd, err = os.Open(tmpPath)
 724                         if err != nil {
 725                                 goto Finish
 726                         }
 727                         defer fd.Close()
 728                 } else if fiStdout.Size() > 0 {
 729                         fd = fdStdout
 730                 }
 731
 732                 // Do we need to ifcreate it, or ifchange with renaming?
 733                 if fd == nil {
 734                         os.Remove(path.Join(cwdOrig, tgt))
 735                         err = ifcreate(fdDep, tgt)
 736                         if err != nil {
 737                                 goto Finish
 738                         }
 739                 } else {
 740                         var hsh string
 741                         if hshPrev != "" {
 742                                 _, err = fd.Seek(0, io.SeekStart)
 743                                 if err != nil {
 744                                         goto Finish
 745                                 }
 746                                 hsh, err = fileHash(fd)
 747                                 if err != nil {
 748                                         goto Finish
 749                                 }
 750                                 if hsh == hshPrev {
 751                                         tracef(CDebug, "%s has same hash, not renaming", tgtOrig)
 752                                         err = os.Remove(fd.Name())
 753                                         if err != nil {
 754                                                 goto Finish
 755                                         }
 756                                         err = os.Chtimes(path.Join(cwdOrig, tgt), finished, finished)
 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, hshPrev)
 767                                         if err != nil {
 768                                                 goto Finish
 769                                         }
 770                                         goto RecCommit
 771                                 }
 772                         }
 773                         if !NoSync {
 774                                 err = fd.Sync()
 775                                 if err != nil {
 776                                         goto Finish
 777                                 }
 778                         }
 779                         err = os.Rename(fd.Name(), path.Join(cwdOrig, tgt))
 780                         if err != nil {
 781                                 goto Finish
 782                         }
 783                         if !NoSync {
 784                                 err = syncDir(cwdOrig)
 785                                 if err != nil {
 786                                         goto Finish
 787                                 }
 788                         }
 789                         err = depWrite(fdDep, cwdOrig, tgt, hsh)
 790                         if err != nil {
 791                                 goto Finish
 792                         }
 793                 }
 794
 795         RecCommit:
 796                 // Commit .rec
 797                 if !NoSync {
 798                         err = fdDep.Sync()
 799                         if err != nil {
 800                                 goto Finish
 801                         }
 802                 }
 803                 fdDepPath = path.Join(redoDir, tgt+DepSuffix)
 804                 err = os.Rename(fdDep.Name(), fdDepPath)
 805                 if err != nil {
 806                         goto Finish
 807                 }
 808                 if !NoSync {
 809                         err = syncDir(redoDir)
 810                         if err != nil {
 811                                 goto Finish
 812                         }
 813                 }
 814
 815                 // Post-commit .rec sanitizing
 816                 fdDep.Close()
 817                 if fdDepR, err := os.Open(fdDepPath); err == nil {
 818                         depInfo, err := depRead(fdDepR)
 819                         fdDepR.Close()
 820                         if err != nil {
 821                                 goto Finish
 822                         }
 823                         ifchangeSeen := make(map[string]struct{}, len(depInfo.ifchanges))
 824                         for _, dep := range depInfo.ifchanges {
 825                                 ifchangeSeen[dep["Target"]] = struct{}{}
 826                         }
 827                         for _, dep := range depInfo.ifcreates {
 828                                 if _, exists := ifchangeSeen[dep]; exists {
 829                                         tracef(CWarn, "simultaneous ifcreate and ifchange records: %s", tgt)
 830                                 }
 831                         }
 832                 }
 833
 834         Finish:
 835                 runErr.Err = err
 836                 errs <- runErr
 837         }()
 838         return nil
 839 }
 840
 841 func isOkRun(err error) bool {
 842         if err == nil {
 843                 return true
 844         }
 845         var runErr RunError
 846         if errors.As(err, &runErr) && runErr.Err == nil {
 847                 tracef(CRedo, "%s", runErr.Name())
 848                 return true
 849         }
 850         tracef(CErr, "%s", err)
 851         return false
 852 }