main.go

   1 /*
   2  * Copyright (C) 2017-2018 "IoT.bzh"
   3  * Author Sebastien Douheret <sebastien@iot.bzh>
   4  *
   5  * Licensed under the Apache License, Version 2.0 (the "License");
   6  * you may not use this file except in compliance with the License.
   7  * You may obtain a copy of the License at
   8  *
   9  *   http://www.apache.org/licenses/LICENSE-2.0
  10  *
  11  * Unless required by applicable law or agreed to in writing, software
  12  * distributed under the License is distributed on an "AS IS" BASIS,
  13  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  14  * See the License for the specific language governing permissions and
  15  * limitations under the License.
  16  *
  17  *
  18  * xds-gdb: a wrapper on gdb tool for X(cross) Development System.
  19  */
  20
  21 package main
  22
  23 import (
  24         "bufio"
  25         "fmt"
  26         "io/ioutil"
  27         "os"
  28         "os/signal"
  29         "os/user"
  30         "syscall"
  31         "time"
  32
  33         "strings"
  34
  35         "path"
  36
  37         common "gerrit.automotivelinux.org/gerrit/src/xds/xds-common.git/golib"
  38         "github.com/Sirupsen/logrus"
  39         "github.com/codegangsta/cli"
  40         "github.com/joho/godotenv"
  41 )
  42
  43 var appAuthors = []cli.Author{
  44         cli.Author{Name: "Sebastien Douheret", Email: "sebastien@iot.bzh"},
  45 }
  46
  47 // AppName name of this application
  48 var AppName = "xds-gdb"
  49
  50 // AppVersion Version of this application
  51 // (set by Makefile)
  52 var AppVersion = "?.?.?"
  53
  54 // AppSubVersion is the git tag id added to version string
  55 // Should be set by compilation -ldflags "-X main.AppSubVersion=xxx"
  56 // (set by Makefile)
  57 var AppSubVersion = "unknown-dev"
  58
  59 // Create logger
  60 var log = logrus.New()
  61 var logFileInitial = path.Join(os.TempDir(), "xds-gdb.log")
  62
  63 // Application details
  64 const (
  65         appCopyright    = "Copyright (C) 2017-2018 IoT.bzh - Apache-2.0"
  66         defaultLogLevel = "warning"
  67 )
  68
  69 // Exit events
  70 type exitResult struct {
  71         error error
  72         code  int
  73 }
  74
  75 // EnvVar - Environment variables used by application
  76 type EnvVar struct {
  77         Name        string
  78         Usage       string
  79         Destination *string
  80 }
  81
  82 // exitError terminates this program with the specified error
  83 func exitError(code syscall.Errno, f string, a ...interface{}) {
  84         err := fmt.Sprintf(f, a...)
  85         fmt.Fprintf(os.Stderr, err+"\n")
  86         log.Debugf("Exit: code=%v, err=%s", code, err)
  87
  88         os.Exit(int(code))
  89 }
  90
  91 // main
  92 func main() {
  93         var agentURL, serverURL string
  94         var prjID, rPath, logLevel, logFile, sdkid, confFile, gdbNative string
  95         var listProject bool
  96         var err error
  97
  98         // Init Logger and set temporary file and level for the 1st part
  99         // IOW while XDS_LOGLEVEL and XDS_LOGFILE options are not parsed
 100         logFile = logFileInitial
 101         fdL, err := os.OpenFile(logFileInitial, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0666)
 102         if err != nil {
 103                 fmt.Printf("WARNING: Cannot create initial log file %s\n", logFileInitial)
 104                 log.Level = logrus.WarnLevel
 105         } else {
 106                 log.Out = fdL
 107                 log.Level = logrus.DebugLevel
 108         }
 109         log.Formatter = &logrus.TextFormatter{}
 110
 111         agentURL = "localhost:8800"
 112         logLevel = defaultLogLevel
 113
 114         // Create a new App instance
 115         app := cli.NewApp()
 116         app.Name = AppName
 117         app.Usage = "wrapper on gdb for X(cross) Development System."
 118         app.Version = AppVersion + " (" + AppSubVersion + ")"
 119         app.Authors = appAuthors
 120         app.Copyright = appCopyright
 121         app.Metadata = make(map[string]interface{})
 122         app.Metadata["version"] = AppVersion
 123         app.Metadata["git-tag"] = AppSubVersion
 124         app.Metadata["logger"] = log
 125
 126         app.Flags = []cli.Flag{
 127                 cli.BoolFlag{
 128                         Name:        "list, ls",
 129                         Usage:       "list existing xds projects",
 130                         Destination: &listProject,
 131                 },
 132         }
 133
 134         appEnvVars := []EnvVar{
 135                 EnvVar{
 136                         Name:        "XDS_CONFIG",
 137                         Usage:       "env config file to source on startup",
 138                         Destination: &confFile,
 139                 },
 140                 EnvVar{
 141                         Name:        "XDS_LOGLEVEL",
 142                         Usage:       "logging level (supported levels: panic, fatal, error, warn, info, debug)",
 143                         Destination: &logLevel,
 144                 },
 145                 EnvVar{
 146                         Name:        "XDS_LOGFILE",
 147                         Usage:       "logging file (default: " + logFileInitial + ")",
 148                         Destination: &logFile,
 149                 },
 150                 EnvVar{
 151                         Name:        "XDS_NATIVE_GDB",
 152                         Usage:       "use native gdb instead of remote XDS server",
 153                         Destination: &gdbNative,
 154                 },
 155                 EnvVar{
 156                         Name:        "XDS_PROJECT_ID",
 157                         Usage:       "project ID you want to build (mandatory variable)",
 158                         Destination: &prjID,
 159                 },
 160                 EnvVar{
 161                         Name:        "XDS_RPATH",
 162                         Usage:       "relative path into project",
 163                         Destination: &rPath,
 164                 },
 165                 EnvVar{
 166                         Name:        "XDS_SDK_ID",
 167                         Usage:       "Cross Sdk ID to use to build project",
 168                         Destination: &sdkid,
 169                 },
 170                 EnvVar{
 171                         Name:        "XDS_AGENT_URL",
 172                         Usage:       "local XDS agent url",
 173                         Destination: &agentURL,
 174                 },
 175                 EnvVar{
 176                         Name:        "XDS_SERVER_URL",
 177                         Usage:       "overwrite remote XDS server url (default value set in xds-agent-config.json file)",
 178                         Destination: &serverURL,
 179                 },
 180         }
 181
 182         // Process gdb arguments
 183         log.Debugf("xds-gdb started with args: %v", os.Args)
 184         args := make([]string, len(os.Args))
 185         args[0] = os.Args[0]
 186         gdbArgs := make([]string, len(os.Args))
 187
 188         // Split xds-xxx options from gdb options
 189         copy(gdbArgs, os.Args[1:])
 190         for idx, a := range os.Args[1:] {
 191                 // Specific case to print help or version of xds-gdb
 192                 switch a {
 193                 case "--help", "-h", "--version", "-v", "--list", "-ls":
 194                         args[1] = a
 195                         goto endloop
 196                 case "--":
 197                         // Detect skip option (IOW '--') to split arguments
 198                         copy(args, os.Args[0:idx+1])
 199                         copy(gdbArgs, os.Args[idx+2:])
 200                         goto endloop
 201                 }
 202         }
 203 endloop:
 204
 205         // Parse gdb arguments to detect:
 206         //  --tty option: used for inferior/ tty of debugged program
 207         //  -x/--command option: XDS env vars may be set within gdb command file
 208         clientPty := ""
 209         gdbCmdFile := ""
 210         for idx, a := range gdbArgs {
 211                 switch {
 212                 case strings.HasPrefix(a, "--tty="):
 213                         clientPty = a[len("--tty="):]
 214                         gdbArgs[idx] = ""
 215
 216                 case a == "--tty":
 217                 case strings.HasPrefix(a, "-tty"):
 218                         clientPty = gdbArgs[idx+1]
 219                         gdbArgs[idx] = ""
 220                         gdbArgs[idx+1] = ""
 221
 222                 case strings.HasPrefix(a, "--command="):
 223                         gdbCmdFile = a[len("--command="):]
 224
 225                 case a == "--command":
 226                 case strings.HasPrefix(a, "-x"):
 227                         gdbCmdFile = gdbArgs[idx+1]
 228                 }
 229         }
 230
 231         // Source config env file
 232         // (we cannot use confFile var because env variables setting is just after)
 233         envMap, confFile, err := loadConfigEnvFile(os.Getenv("XDS_CONFIG"), gdbCmdFile)
 234         log.Infof("Load env config: envMap=%v, confFile=%v, err=%v", envMap, confFile, err)
 235
 236         // Only rise an error when args is not set (IOW when --help or --version is not set)
 237         if len(args) == 1 {
 238                 if err != nil {
 239                         exitError(syscall.ENOENT, err.Error())
 240                 }
 241         }
 242
 243         // Managed env vars and create help
 244         dynDesc := "\nENVIRONMENT VARIABLES:"
 245         for _, ev := range appEnvVars {
 246                 dynDesc += fmt.Sprintf("\n %s \t\t %s", ev.Name, ev.Usage)
 247                 if evVal, evExist := os.LookupEnv(ev.Name); evExist && ev.Destination != nil {
 248                         *ev.Destination = evVal
 249                 }
 250         }
 251         app.Description = "gdb wrapper for X(cross) Development System\n"
 252         app.Description += "\n"
 253         app.Description += " Two debugging models are supported:\n"
 254         app.Description += "  - xds remote debugging requiring an XDS server and allowing cross debug\n"
 255         app.Description += "  - native debugging\n"
 256         app.Description += " By default xds remote debug is used and you need to define XDS_NATIVE_GDB to\n"
 257         app.Description += " use native gdb debug mode instead.\n"
 258         app.Description += "\n"
 259         app.Description += " xds-gdb configuration (see variables list below) can be set using:\n"
 260         app.Description += "  - a config file (XDS_CONFIG)\n"
 261         app.Description += "  - or environment variables\n"
 262         app.Description += "  - or by setting variables within gdb ini file (commented line including :XDS-ENV: tag)\n"
 263         app.Description += "    Example of gdb ini file where we define project and sdk ID:\n"
 264         app.Description += "     # :XDS-ENV: XDS_PROJECT_ID=IW7B4EE-DBY4Z74_myProject\n"
 265         app.Description += "     # :XDS-ENV: XDS_SDK_ID=poky-agl_aarch64_3.99.1+snapshot\n"
 266         app.Description += "\n"
 267         app.Description += dynDesc + "\n"
 268
 269         // only one action
 270         app.Action = func(ctx *cli.Context) error {
 271                 var err error
 272                 curDir, _ := os.Getwd()
 273
 274                 // Build env variables
 275                 env := []string{}
 276                 for k, v := range envMap {
 277                         env = append(env, k+"="+v)
 278                 }
 279
 280                 // Now set logger level and log file to correct/env var settings
 281                 if log.Level, err = logrus.ParseLevel(logLevel); err != nil {
 282                         msg := fmt.Sprintf("Invalid log level : \"%v\"\n", logLevel)
 283                         return cli.NewExitError(msg, int(syscall.EINVAL))
 284                 }
 285                 log.Infof("Switch log level to %s", logLevel)
 286
 287                 if logFile != logFileInitial {
 288                         log.Infof("Switch logging to log file %s", logFile)
 289
 290                         fdL, err := os.OpenFile(logFile, os.O_CREATE|os.O_TRUNC|os.O_WRONLY, 0666)
 291                         if err != nil {
 292                                 msgErr := fmt.Sprintf("Cannot create log file %s", logFile)
 293                                 return cli.NewExitError(msgErr, int(syscall.EPERM))
 294                         }
 295                         defer fdL.Close()
 296                         log.Out = fdL
 297                 }
 298
 299                 // Create cross or native gdb interface
 300                 var gdb IGDB
 301                 if gdbNative != "" {
 302                         gdb = NewGdbNative(log, gdbArgs, env)
 303                 } else {
 304                         gdb = NewGdbXds(log, gdbArgs, env)
 305                         gdb.SetConfig("agentURL", agentURL)
 306                         gdb.SetConfig("serverURL", serverURL)
 307                         gdb.SetConfig("prjID", prjID)
 308                         gdb.SetConfig("sdkID", sdkid)
 309                         gdb.SetConfig("rPath", rPath)
 310                         gdb.SetConfig("listProject", listProject)
 311                 }
 312
 313                 // Log useful info
 314                 log.Infof("Original arguments: %v", os.Args)
 315                 log.Infof("Current directory : %v", curDir)
 316                 log.Infof("Use confFile      : '%s'", confFile)
 317                 log.Infof("Execute           : /exec %v %v", gdb.Cmd(), gdb.Args())
 318
 319                 // Properly report invalid init file error
 320                 gdbCommandFileError := ""
 321                 for i, a := range gdbArgs {
 322                         if a == "-x" {
 323                                 gdbCommandFileError = gdbArgs[i+1] + ": No such file or directory."
 324                                 break
 325                         } else if strings.HasPrefix(a, "--command=") {
 326                                 gdbCommandFileError = strings.TrimLeft(a, "--command=") + ": No such file or directory."
 327                                 break
 328                         }
 329                 }
 330                 log.Infof("Add detection of error: <%s>", gdbCommandFileError)
 331
 332                 // Init gdb subprocess management
 333                 if code, err := gdb.Init(); err != nil {
 334                         return cli.NewExitError(err.Error(), code)
 335                 }
 336
 337                 exitChan := make(chan exitResult, 1)
 338
 339                 gdb.OnError(func(err error) {
 340                         fmt.Println("ERROR: ", err.Error())
 341                 })
 342
 343                 gdb.OnDisconnect(func(err error) {
 344                         errMsg := "\nXDS-Agent disconnected"
 345                         if err != nil {
 346                                 fmt.Printf("%s: %v\n", errMsg, err.Error())
 347                         } else {
 348                                 fmt.Println(errMsg)
 349                         }
 350
 351                         exitChan <- exitResult{err, int(syscall.ESHUTDOWN)}
 352                 })
 353
 354                 gdb.Read(func(timestamp, stdout, stderr string) {
 355                         if stdout != "" {
 356                                 fmt.Printf("%s", stdout)
 357                                 log.Debugf("Recv OUT: <%s>", stdout)
 358                         }
 359                         if stderr != "" {
 360                                 // Filter-out ugly message (python error when cross gdb exited)
 361                                 if !strings.Contains(stderr, "readline.write_history_file") &&
 362                                         !(strings.Contains(stderr, "Traceback") && strings.Contains(stderr, "__exithandler")) {
 363                                         fmt.Fprintf(os.Stderr, "%s", stderr)
 364                                         log.Debugf("Recv ERR: <%s>", stderr)
 365                                 } else {
 366                                         log.Debugf("Recv ERR (FILTERED OUT): <%s>", stderr)
 367                                 }
 368                         }
 369
 370                         // Correctly report error about init file
 371                         if gdbCommandFileError != "" && strings.Contains(stdout, gdbCommandFileError) {
 372                                 fmt.Fprintf(os.Stderr, "ERROR: "+gdbCommandFileError)
 373                                 log.Errorf("ERROR: " + gdbCommandFileError)
 374                                 if err := gdb.SendSignal(syscall.SIGTERM); err != nil {
 375                                         log.Errorf("Error while sending signal: %s", err.Error())
 376                                 }
 377                                 exitChan <- exitResult{err, int(syscall.ENOENT)}
 378                         }
 379                 })
 380
 381                 gdb.OnExit(func(code int, err error) {
 382                         exitChan <- exitResult{err, code}
 383                 })
 384
 385                 // Handle client tty / pts
 386                 if clientPty != "" {
 387                         log.Infoln("Client tty detected: %v", clientPty)
 388
 389                         cpFd, err := os.OpenFile(clientPty, os.O_RDWR, 0)
 390                         if err != nil {
 391                                 return cli.NewExitError(err.Error(), int(syscall.EPERM))
 392                         }
 393                         defer cpFd.Close()
 394
 395                         // client tty stdin
 396                         /* XXX TODO - implement stdin to send data to debugged program
 397                         go func() {
 398                                 reader := bufio.NewReader(cpFd)
 399                                 sc := bufio.NewScanner(reader)
 400                                 for sc.Scan() {
 401                                         data := sc.Text()
 402                                         iosk.Emit(xaapiv1.ExecInferiorInEvent, data+"\n")
 403                                         log.Debugf("Inferior IN: <%v>", data)
 404                                 }
 405                                 if sc.Err() != nil {
 406                                         log.Warnf("Inferior Stdin scanner exit, close stdin (err=%v)", sc.Err())
 407                                 }
 408                         }()
 409                         */
 410
 411                         // client tty stdout
 412                         gdb.InferiorRead(func(timestamp, stdout, stderr string) {
 413                                 if stdout != "" {
 414                                         fmt.Fprintf(cpFd, "%s", stdout)
 415                                         log.Debugf("Inferior OUT: <%s>", stdout)
 416                                 }
 417                                 if stderr != "" {
 418                                         fmt.Fprintf(cpFd, "%s", stderr)
 419                                         log.Debugf("Inferior ERR: <%s>", stderr)
 420                                 }
 421                         })
 422                 }
 423
 424                 // Allow to overwrite some gdb commands
 425                 var overwriteMap = make(map[string]string)
 426                 if overEnv, exist := os.LookupEnv("XDS_OVERWRITE_COMMANDS"); exist {
 427                         overEnvS := strings.TrimSpace(overEnv)
 428                         if len(overEnvS) > 0 {
 429                                 // Extract overwrite commands from env variable
 430                                 for _, def := range strings.Split(overEnvS, ",") {
 431                                         if kv := strings.Split(def, ":"); len(kv) == 2 {
 432                                                 overwriteMap[strings.TrimSpace(kv[0])] = strings.TrimSpace(kv[1])
 433                                         } else {
 434                                                 return cli.NewExitError(
 435                                                         fmt.Errorf("Invalid definition in XDS_OVERWRITE_COMMANDS (%s)", def),
 436                                                         int(syscall.EINVAL))
 437                                         }
 438                                 }
 439                         }
 440                 } else {
 441                         overwriteMap["-exec-run"] = "-exec-continue"
 442                         overwriteMap["-file-exec-and-symbols"] = "-file-exec-file"
 443                 }
 444                 log.Debugf("overwriteMap = %v", overwriteMap)
 445
 446                 // Send stdin though WS
 447                 go func() {
 448                         paranoia := 600
 449                         reader := bufio.NewReader(os.Stdin)
 450
 451                         // Enable workaround to correctly close connection
 452                         // except if XDS_GDBSERVER_EXIT_NOFIX is defined
 453                         _, gdbExitNoFix := os.LookupEnv("XDS_GDBSERVER_EXIT_NOFIX")
 454
 455                         for {
 456                                 sc := bufio.NewScanner(reader)
 457                                 for sc.Scan() {
 458                                         command := sc.Text()
 459
 460                                         // overwrite some commands
 461                                         for key, value := range overwriteMap {
 462                                                 if strings.Contains(command, key) {
 463                                                         command = strings.Replace(command, key, value, 1)
 464                                                         log.Debugf("OVERWRITE %s -> %s", key, value)
 465                                                 }
 466                                         }
 467
 468                                         // Send SIGINT to stop debugged process execution before sending -gdb-exit command
 469                                         if !gdbExitNoFix && strings.Contains(command, "-gdb-exit") {
 470                                                 log.Infof("Detection of -gdb-exit, exiting...")
 471                                                 if err := gdb.SendSignal(syscall.SIGINT); err != nil {
 472                                                         log.Errorf("Error while sending signal SIGINT : %s", err.Error())
 473                                                 }
 474                                                 time.Sleep(time.Millisecond * 200)
 475                                         }
 476
 477                                         log.Debugf("Send: <%v>", command)
 478                                         gdb.Write(command + "\n")
 479                                 }
 480                                 log.Infof("Stdin scanner exit, close stdin (err=%v)", sc.Err())
 481
 482                                 // CTRL-D exited scanner, so send it explicitly
 483                                 gdb.Write("\x04")
 484                                 time.Sleep(time.Millisecond * 100)
 485
 486                                 if paranoia--; paranoia <= 0 {
 487                                         msg := "Abnormal loop detected on stdin"
 488                                         log.Errorf("Abnormal loop detected on stdin")
 489                                         gdb.SendSignal(syscall.SIGTERM)
 490                                         exitChan <- exitResult{fmt.Errorf(msg), int(syscall.ELOOP)}
 491                                 }
 492                         }
 493                 }()
 494
 495                 // Handling all Signals
 496                 sigs := make(chan os.Signal, 1)
 497                 signal.Notify(sigs)
 498
 499                 go func() {
 500                         for {
 501                                 sig := <-sigs
 502
 503                                 if isIgnoredSignal(sig) {
 504                                         return
 505                                 }
 506
 507                                 if err := gdb.SendSignal(sig); err != nil {
 508                                         log.Errorf("Error while sending signal %v : %s", sig, err.Error())
 509                                 }
 510                         }
 511                 }()
 512
 513                 // Start gdb
 514                 if code, err := gdb.Start(clientPty != ""); err != nil {
 515                         return cli.NewExitError(err.Error(), code)
 516                 }
 517
 518                 // Wait exit
 519                 select {
 520                 case res := <-exitChan:
 521                         errStr := ""
 522                         if res.code == 0 {
 523                                 log.Infoln("Exit successfully")
 524                         }
 525                         if res.error != nil {
 526                                 log.Infoln("Exit with ERROR: ", res.error.Error())
 527                                 errStr = res.error.Error()
 528                         }
 529                         return cli.NewExitError(errStr, res.code)
 530                 }
 531         }
 532
 533         app.Run(args)
 534 }
 535
 536 // loadConfigEnvFile
 537 func loadConfigEnvFile(confFile, gdbCmdFile string) (map[string]string, string, error) {
 538         var err error
 539         envMap := make(map[string]string)
 540
 541         // 1- if no confFile set, use setting from gdb command file is option
 542         //    --command/-x is set
 543         if confFile == "" && gdbCmdFile != "" {
 544                 log.Infof("Try extract config from gdbCmdFile: %s", gdbCmdFile)
 545                 confFile, err = extractEnvFromCmdFile(gdbCmdFile)
 546                 if confFile != "" {
 547                         defer os.Remove(confFile)
 548                 }
 549                 if err != nil {
 550                         log.Infof("Extraction from gdbCmdFile failed: %v", err.Error())
 551                 }
 552         }
 553         // 2- search xds-gdb.env file in various locations
 554         if confFile == "" {
 555                 curDir, _ := os.Getwd()
 556                 if u, err := user.Current(); err == nil {
 557                         xdsEnvFile := "xds-gdb.env"
 558                         for _, d := range []string{
 559                                 path.Join(curDir),
 560                                 path.Join(curDir, ".."),
 561                                 path.Join(curDir, "target"),
 562                                 path.Join(u.HomeDir, ".config", "xds"),
 563                         } {
 564                                 cf := path.Join(d, xdsEnvFile)
 565                                 log.Infof("Search config in %s", cf)
 566                                 if common.Exists(cf) {
 567                                         confFile = cf
 568                                         break
 569                                 }
 570                         }
 571                 }
 572         }
 573
 574         if confFile == "" {
 575                 log.Infof("NO valid conf file found!")
 576                 return envMap, "", nil
 577         }
 578
 579         if !common.Exists(confFile) {
 580                 return envMap, confFile, fmt.Errorf("Error no env config file not found")
 581         }
 582         if err = godotenv.Load(confFile); err != nil {
 583                 return envMap, confFile, fmt.Errorf("Error loading env config file " + confFile)
 584         }
 585         if envMap, err = godotenv.Read(confFile); err != nil {
 586                 return envMap, confFile, fmt.Errorf("Error reading env config file " + confFile)
 587         }
 588
 589         return envMap, confFile, nil
 590 }
 591
 592 /*
 593  extractEnvFromCmdFile: extract xds-gdb env variable from gdb command file
 594   All commented lines (#) in gdb command file that start with ':XDS-ENV:' prefix
 595   will be considered as XDS env commands. For example the 3 syntaxes below
 596   are supported:
 597   # :XDS-ENV: XDS_PROJECT_ID=4021617e-ced0-11e7-acd2-3c970e49ad9b
 598   #:XDS-ENV:XDS_SDK_ID=06c0e95a-e215-3a5a-b373-f677c0dabd3b
 599   # :XDS-ENV:  export XDS_AGENT_URL=localhost:8800
 600 */
 601 func extractEnvFromCmdFile(cmdFile string) (string, error) {
 602         if !common.Exists(cmdFile) {
 603                 return "", nil
 604         }
 605         cFd, err := os.Open(cmdFile)
 606         if err != nil {
 607                 return "", fmt.Errorf("Cannot open %s : %s", cmdFile, err.Error())
 608         }
 609         defer cFd.Close()
 610
 611         var lines []string
 612         scanner := bufio.NewScanner(cFd)
 613         for scanner.Scan() {
 614                 lines = append(lines, scanner.Text())
 615         }
 616         if err = scanner.Err(); err != nil {
 617                 return "", fmt.Errorf("Cannot parse %s : %s", cmdFile, err.Error())
 618         }
 619
 620         envFile, err := ioutil.TempFile("", "xds-gdb_env.ini")
 621         if err != nil {
 622                 return "", fmt.Errorf("Error while creating temporary env file: %s", err.Error())
 623         }
 624         envFileName := envFile.Name()
 625         defer envFile.Close()
 626
 627         envFound := false
 628         for _, ln := range lines {
 629                 ln = strings.TrimSpace(ln)
 630                 if strings.HasPrefix(ln, "#") && strings.Contains(ln, ":XDS-ENV:") {
 631                         env := strings.SplitAfterN(ln, ":XDS-ENV:", 2)
 632                         if len(env) == 2 {
 633                                 envFound = true
 634                                 if _, err := envFile.WriteString(strings.TrimSpace(env[1]) + "\n"); err != nil {
 635                                         return "", fmt.Errorf("Error write into temporary env file: %s", err.Error())
 636                                 }
 637                         } else {
 638                                 log.Warnf("Error while decoding line %s", ln)
 639                         }
 640                 }
 641         }
 642
 643         if !envFound {
 644                 ff := envFileName
 645                 defer os.Remove(ff)
 646                 envFileName = ""
 647
 648         }
 649
 650         return envFileName, nil
 651 }