converter/babeltrace.c

   1 /*
   2  * babeltrace.c
   3  *
   4  * Babeltrace Trace Converter
   5  *
   6  * Copyright 2010-2011 EfficiOS Inc. and Linux Foundation
   7  *
   8  * Author: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
   9  *
  10  * Permission is hereby granted, free of charge, to any person obtaining a copy
  11  * of this software and associated documentation files (the "Software"), to deal
  12  * in the Software without restriction, including without limitation the rights
  13  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  14  * copies of the Software, and to permit persons to whom the Software is
  15  * furnished to do so, subject to the following conditions:
  16  *
  17  * The above copyright notice and this permission notice shall be included in
  18  * all copies or substantial portions of the Software.
  19  */
  20
  21 #define _XOPEN_SOURCE 700
  22 #include <config.h>
  23 #include <babeltrace/babeltrace.h>
  24 #include <babeltrace/format.h>
  25 #include <babeltrace/context.h>
  26 #include <babeltrace/ctf/types.h>
  27 #include <abeltrace/ctf-text/types.h>
  28 #include <babeltrace/iterator.h>
  29 #include <popt.h>
  30 #include <errno.h>
  31 #include <stdlib.h>
  32 #include <ctype.h>
  33 #include <sys/stat.h>
  34 #include <sys/types.h>
  35 #include <fcntl.h>
  36 #include <ftw.h>
  37 #include <dirent.h>
  38 #include <unistd.h>
  39 #include <inttypes.h>
  40
  41 #include <babeltrace/ctf-ir/metadata.h> /* for clocks */
  42
  43 #define DEFAULT_FILE_ARRAY_SIZE 1
  44 static char *opt_input_format;
  45 static char *opt_output_format;
  46
  47 static const char *opt_input_path;
  48 static const char *opt_output_path;
  49
  50 static struct trace_collection trace_collection_read;
  51 static struct format *fmt_read;
  52
  53 void strlower(char *str)
  54 {
  55         while (*str) {
  56                 *str = tolower(*str);
  57                 str++;
  58         }
  59 }
  60
  61 enum {
  62         OPT_NONE = 0,
  63         OPT_HELP,
  64         OPT_LIST,
  65         OPT_VERBOSE,
  66         OPT_DEBUG,
  67         OPT_NAMES,
  68         OPT_FIELDS,
  69         OPT_NO_DELTA,
  70         OPT_CLOCK_OFFSET,
  71         OPT_CLOCK_RAW,
  72         OPT_CLOCK_SECONDS,
  73         OPT_CLOCK_DATE,
  74         OPT_CLOCK_GMT,
  75 };
  76
  77 static struct poptOption long_options[] = {
  78         /* longName, shortName, argInfo, argPtr, value, descrip, argDesc */
  79         { "input-format", 'i', POPT_ARG_STRING, &opt_input_format, OPT_NONE, NULL, NULL },
  80         { "output-format", 'o', POPT_ARG_STRING, &opt_output_format, OPT_NONE, NULL, NULL },
  81         { "help", 'h', POPT_ARG_NONE, NULL, OPT_HELP, NULL, NULL },
  82         { "list", 'l', POPT_ARG_NONE, NULL, OPT_LIST, NULL, NULL },
  83         { "verbose", 'v', POPT_ARG_NONE, NULL, OPT_VERBOSE, NULL, NULL },
  84         { "debug", 'd', POPT_ARG_NONE, NULL, OPT_DEBUG, NULL, NULL },
  85         { "names", 'n', POPT_ARG_STRING, NULL, OPT_NAMES, NULL, NULL },
  86         { "fields", 'f', POPT_ARG_STRING, NULL, OPT_FIELDS, NULL, NULL },
  87         { "no-delta", 0, POPT_ARG_NONE, NULL, OPT_NO_DELTA, NULL, NULL },
  88         { "clock-offset", 0, POPT_ARG_STRING, NULL, OPT_CLOCK_OFFSET, NULL, NULL },
  89         { "clock-raw", 0, POPT_ARG_NONE, NULL, OPT_CLOCK_RAW, NULL, NULL },
  90         { "clock-seconds", 0, POPT_ARG_NONE, NULL, OPT_CLOCK_SECONDS, NULL, NULL },
  91         { "clock-date", 0, POPT_ARG_NONE, NULL, OPT_CLOCK_DATE, NULL, NULL },
  92         { "clock-gmt", 0, POPT_ARG_NONE, NULL, OPT_CLOCK_GMT, NULL, NULL },
  93         { NULL, 0, 0, NULL, 0, NULL, NULL },
  94 };
  95
  96 static void list_formats(FILE *fp)
  97 {
  98         fprintf(fp, "\n");
  99         bt_fprintf_format_list(fp);
 100 }
 101
 102 static void usage(FILE *fp)
 103 {
 104         fprintf(fp, "BabelTrace Trace Viewer and Converter %s\n\n", VERSION);
 105         fprintf(fp, "usage : babeltrace [OPTIONS] INPUT <OUTPUT>\n");
 106         fprintf(fp, "\n");
 107         fprintf(fp, "  INPUT                          Input trace path\n");
 108         fprintf(fp, "  OUTPUT                         Output trace path (default: stdout)\n");
 109         fprintf(fp, "\n");
 110         fprintf(fp, "  -i, --input-format FORMAT      Input trace format (default: ctf)\n");
 111         fprintf(fp, "  -o, --output-format FORMAT     Output trace format (default: text)\n");
 112         fprintf(fp, "\n");
 113         fprintf(fp, "  -h, --help                     This help message\n");
 114         fprintf(fp, "  -l, --list                     List available formats\n");
 115         fprintf(fp, "  -v, --verbose                  Verbose mode\n");
 116         fprintf(fp, "                                 (or set BABELTRACE_VERBOSE environment variable)\n");
 117         fprintf(fp, "  -d, --debug                    Debug mode\n");
 118         fprintf(fp, "                                 (or set BABELTRACE_DEBUG environment variable)\n");
 119         fprintf(fp, "      --no-delta                 Do not print time delta between consecutive events\n");
 120         fprintf(fp, "  -n, --names name1<,name2,...>  Print field names:\n");
 121         fprintf(fp, "                                     (payload OR args OR arg)\n");
 122         fprintf(fp, "                                     all, scope, header, (context OR ctx)\n");
 123         fprintf(fp, "                                        (payload active by default)\n");
 124         fprintf(fp, "  -f, --fields name1<,name2,...> Print additional fields:\n");
 125         fprintf(fp, "                                     all, trace, trace:domain, trace:procname,\n");
 126         fprintf(fp, "                                     trace:vpid, loglevel.\n");
 127         fprintf(fp, "      --clock-raw                Disregard internal clock offset (use raw value)\n");
 128         fprintf(fp, "      --clock-offset seconds     Clock offset in seconds\n");
 129         fprintf(fp, "      --clock-seconds            Print the timestamps as [sec.ns]\n");
 130         fprintf(fp, "                                 (default is: [hh:mm:ss.ns])\n");
 131         fprintf(fp, "      --clock-date               Print clock date\n");
 132         fprintf(fp, "      --clock-gmt                Print clock in GMT time zone (default: local time zone)\n");
 133         list_formats(fp);
 134         fprintf(fp, "\n");
 135 }
 136
 137 static int get_names_args(poptContext *pc)
 138 {
 139         char *str, *strlist, *strctx;
 140
 141         opt_payload_field_names = 0;
 142         strlist = (char *) poptGetOptArg(*pc);
 143         if (!strlist) {
 144                 return -EINVAL;
 145         }
 146         str = strtok_r(strlist, ",", &strctx);
 147         do {
 148                 if (!strcmp(str, "all"))
 149                         opt_all_field_names = 1;
 150                 else if (!strcmp(str, "scope"))
 151                         opt_scope_field_names = 1;
 152                 else if (!strcmp(str, "context") || !strcmp(str, "ctx"))
 153                         opt_context_field_names = 1;
 154                 else if (!strcmp(str, "header"))
 155                         opt_header_field_names = 1;
 156                 else if (!strcmp(str, "payload") || !strcmp(str, "args") || !strcmp(str, "arg"))
 157                         opt_payload_field_names = 1;
 158                 else {
 159                         fprintf(stderr, "[error] unknown field name type %s\n", str);
 160                         return -EINVAL;
 161                 }
 162         } while ((str = strtok_r(NULL, ",", &strctx)));
 163         return 0;
 164 }
 165
 166 static int get_fields_args(poptContext *pc)
 167 {
 168         char *str, *strlist, *strctx;
 169
 170         strlist = (char *) poptGetOptArg(*pc);
 171         if (!strlist) {
 172                 return -EINVAL;
 173         }
 174         str = strtok_r(strlist, ",", &strctx);
 175         do {
 176                 if (!strcmp(str, "all"))
 177                         opt_all_fields = 1;
 178                 else if (!strcmp(str, "trace"))
 179                         opt_trace_field = 1;
 180                 else if (!strcmp(str, "trace:domain"))
 181                         opt_trace_domain_field = 1;
 182                 else if (!strcmp(str, "trace:procname"))
 183                         opt_trace_procname_field = 1;
 184                 else if (!strcmp(str, "trace:vpid"))
 185                         opt_trace_vpid_field = 1;
 186                 else if (!strcmp(str, "loglevel"))
 187                         opt_loglevel_field = 1;
 188                 else {
 189                         fprintf(stderr, "[error] unknown field type %s\n", str);
 190                         return -EINVAL;
 191                 }
 192         } while ((str = strtok_r(NULL, ",", &strctx)));
 193         return 0;
 194 }
 195
 196 /*
 197  * Return 0 if caller should continue, < 0 if caller should return
 198  * error, > 0 if caller should exit without reporting error.
 199  */
 200 static int parse_options(int argc, char **argv)
 201 {
 202         poptContext pc;
 203         int opt, ret = 0;
 204
 205         if (argc == 1) {
 206                 usage(stdout);
 207                 return 1;       /* exit cleanly */
 208         }
 209
 210         pc = poptGetContext(NULL, argc, (const char **) argv, long_options, 0);
 211         poptReadDefaultConfig(pc, 0);
 212
 213         /* set default */
 214         opt_payload_field_names = 1;
 215
 216         while ((opt = poptGetNextOpt(pc)) != -1) {
 217                 switch (opt) {
 218                 case OPT_HELP:
 219                         usage(stdout);
 220                         ret = 1;        /* exit cleanly */
 221                         goto end;
 222                 case OPT_LIST:
 223                         list_formats(stdout);
 224                         ret = 1;
 225                         goto end;
 226                 case OPT_VERBOSE:
 227                         babeltrace_verbose = 1;
 228                         break;
 229                 case OPT_NAMES:
 230                         if (get_names_args(&pc)) {
 231                                 ret = -EINVAL;
 232                                 goto end;
 233                         }
 234                         break;
 235                 case OPT_FIELDS:
 236                         if (get_fields_args(&pc)) {
 237                                 ret = -EINVAL;
 238                                 goto end;
 239                         }
 240                         break;
 241                 case OPT_DEBUG:
 242                         babeltrace_debug = 1;
 243                         break;
 244                 case OPT_NO_DELTA:
 245                         opt_delta_field = 0;
 246                         break;
 247                 case OPT_CLOCK_RAW:
 248                         opt_clock_raw = 1;
 249                         break;
 250                 case OPT_CLOCK_OFFSET:
 251                 {
 252                         char *str, *endptr;
 253
 254                         str = poptGetOptArg(pc);
 255                         if (!str) {
 256                                 fprintf(stderr, "[error] Missing --clock-offset argument\n");
 257                                 ret = -EINVAL;
 258                                 goto end;
 259                         }
 260                         errno = 0;
 261                         opt_clock_offset = strtoull(str, &endptr, 0);
 262                         if (*endptr != '\0' || str == endptr || errno != 0) {
 263                                 fprintf(stderr, "[error] Incorrect --clock-offset argument: %s\n", str);
 264                                 ret = -EINVAL;
 265                                 goto end;
 266                         }
 267                         break;
 268                 }
 269                 case OPT_CLOCK_SECONDS:
 270                         opt_clock_seconds = 1;
 271                         break;
 272                 case OPT_CLOCK_DATE:
 273                         opt_clock_date = 1;
 274                         break;
 275                 case OPT_CLOCK_GMT:
 276                         opt_clock_gmt = 1;
 277                         break;
 278
 279                 default:
 280                         ret = -EINVAL;
 281                         goto end;
 282                 }
 283         }
 284
 285         opt_input_path = poptGetArg(pc);
 286         if (!opt_input_path) {
 287                 ret = -EINVAL;
 288                 goto end;
 289         }
 290         opt_output_path = poptGetArg(pc);
 291
 292 end:
 293         if (pc) {
 294                 poptFreeContext(pc);
 295         }
 296         return ret;
 297 }
 298
 299 static void init_trace_collection(struct trace_collection *tc)
 300 {
 301         tc->array = g_ptr_array_sized_new(DEFAULT_FILE_ARRAY_SIZE);
 302         tc->clocks = g_hash_table_new(g_direct_hash, g_direct_equal);
 303         tc->single_clock_offset_avg = 0;
 304         tc->offset_first = 0;
 305         tc->delta_offset_first_sum = 0;
 306         tc->offset_nr = 0;
 307 }
 308
 309 /*
 310  * finalize_trace_collection() closes the opened traces for read
 311  * and free the memory allocated for trace collection
 312  */
 313 static void finalize_trace_collection(struct trace_collection *tc)
 314 {
 315         int i;
 316
 317         for (i = 0; i < tc->array->len; i++) {
 318                 struct trace_descriptor *temp =
 319                         g_ptr_array_index(tc->array, i);
 320                 fmt_read->close_trace(temp);
 321         }
 322         g_ptr_array_free(tc->array, TRUE);
 323         g_hash_table_destroy(tc->clocks);
 324 }
 325
 326 struct clock_match {
 327         GHashTable *clocks;
 328         struct ctf_clock *clock_match;
 329         struct trace_collection *tc;
 330 };
 331
 332 static void check_clock_match(gpointer key, gpointer value, gpointer user_data)
 333 {
 334         struct clock_match *match = user_data;
 335         struct ctf_clock *clock_a = value, *clock_b;
 336
 337         if (clock_a->uuid != 0) {
 338                 /*
 339                  * Lookup the the trace clocks into the collection
 340                  * clocks.
 341                  */
 342                 clock_b = g_hash_table_lookup(match->clocks,
 343                         (gpointer) (unsigned long) clock_a->uuid);
 344                 if (clock_b) {
 345                         match->clock_match = clock_b;
 346                         return;
 347                 }
 348         } else if (clock_a->absolute) {
 349                 /*
 350                  * Absolute time references, such as NTP, are looked up
 351                  * by clock name.
 352                  */
 353                 clock_b = g_hash_table_lookup(match->clocks,
 354                         (gpointer) (unsigned long) clock_a->name);
 355                 if (clock_b) {
 356                         match->clock_match = clock_b;
 357                         return;
 358                 }
 359         }
 360 }
 361
 362 static void clock_add(gpointer key, gpointer value, gpointer user_data)
 363 {
 364         struct clock_match *clock_match = user_data;
 365         GHashTable *tc_clocks = clock_match->clocks;
 366         struct ctf_clock *t_clock = value;
 367         GQuark v;
 368
 369         if (t_clock->absolute)
 370                 v = t_clock->name;
 371         else
 372                 v = t_clock->uuid;
 373         if (v) {
 374                 struct ctf_clock *tc_clock;
 375
 376                 tc_clock = g_hash_table_lookup(tc_clocks,
 377                                 (gpointer) (unsigned long) v);
 378                 if (!tc_clock) {
 379                         /*
 380                          * For now, we only support CTF that has one
 381                          * single clock uuid or name (absolute ref).
 382                          */
 383                         if (g_hash_table_size(tc_clocks) > 0) {
 384                                 fprintf(stderr, "[error] Only CTF traces with a single clock description are supported by this babeltrace version.\n");
 385                         }
 386                         if (!clock_match->tc->offset_nr) {
 387                                 clock_match->tc->offset_first =
 388                                         (t_clock->offset_s * 1000000000ULL) + t_clock->offset;
 389                                 clock_match->tc->delta_offset_first_sum = 0;
 390                                 clock_match->tc->offset_nr++;
 391                                 clock_match->tc->single_clock_offset_avg =
 392                                         clock_match->tc->offset_first;
 393                         }
 394                         g_hash_table_insert(tc_clocks,
 395                                 (gpointer) (unsigned long) v,
 396                                 value);
 397                 } else {
 398                         int64_t diff_ns;
 399
 400                         /*
 401                          * Check that the offsets match. If not, warn
 402                          * the user that we do an arbitrary choice.
 403                          */
 404                         diff_ns = tc_clock->offset_s;
 405                         diff_ns -= t_clock->offset_s;
 406                         diff_ns *= 1000000000ULL;
 407                         diff_ns += tc_clock->offset;
 408                         diff_ns -= t_clock->offset;
 409                         printf_debug("Clock \"%s\" offset between traces has a delta of %" PRIu64 " ns.",
 410                                 g_quark_to_string(tc_clock->name),
 411                                 diff_ns < 0 ? -diff_ns : diff_ns);
 412                         if (diff_ns > 10000) {
 413                                 fprintf(stderr, "[warning] Clock \"%s\" offset differs between traces (delta %" PRIu64 " ns). Using average.\n",
 414                                         g_quark_to_string(tc_clock->name),
 415                                         diff_ns < 0 ? -diff_ns : diff_ns);
 416                         }
 417                         /* Compute average */
 418                         clock_match->tc->delta_offset_first_sum +=
 419                                 (t_clock->offset_s * 1000000000ULL) + t_clock->offset
 420                                 - clock_match->tc->offset_first;
 421                         clock_match->tc->offset_nr++;
 422                         clock_match->tc->single_clock_offset_avg =
 423                                 clock_match->tc->offset_first
 424                                 + (clock_match->tc->delta_offset_first_sum / clock_match->tc->offset_nr);
 425                 }
 426         }
 427 }
 428
 429 /*
 430  * Whenever we add a trace to the trace collection, check that we can
 431  * correlate this trace with at least one other clock in the trace.
 432  */
 433 static int trace_collection_add(struct trace_collection *tc,
 434                                 struct trace_descriptor *td)
 435 {
 436         struct ctf_trace *trace = container_of(td, struct ctf_trace, parent);
 437
 438         g_ptr_array_add(tc->array, td);
 439         trace->collection = tc;
 440
 441         if (tc->array->len > 1) {
 442                 struct clock_match clock_match = {
 443                         .clocks = tc->clocks,
 444                         .clock_match = NULL,
 445                         .tc = NULL,
 446                 };
 447
 448                 /*
 449                  * With two or more traces, we need correlation info
 450                  * avalable.
 451                  */
 452                 g_hash_table_foreach(trace->clocks,
 453                                 check_clock_match,
 454                                 &clock_match);
 455                 if (!clock_match.clock_match) {
 456                         fprintf(stderr, "[error] No clocks can be correlated and multiple traces are added to the collection.\n");
 457                         goto error;
 458                 }
 459         }
 460
 461         {
 462                 struct clock_match clock_match = {
 463                         .clocks = tc->clocks,
 464                         .clock_match = NULL,
 465                         .tc = tc,
 466                 };
 467
 468                 /*
 469                  * Add each clock from the trace clocks into the trace
 470                  * collection clocks.
 471                  */
 472                 g_hash_table_foreach(trace->clocks,
 473                                 clock_add,
 474                                 &clock_match);
 475         }
 476         return 0;
 477 error:
 478         return -EPERM;
 479 }
 480
 481 int convert_trace(struct trace_descriptor *td_write,
 482                   struct bt_context *ctx)
 483 {
 484         struct bt_iter *iter;
 485         struct ctf_stream *stream;
 486         struct ctf_stream_event *event;
 487         struct ctf_text_stream_pos *sout;
 488         struct bt_iter_pos begin_pos;
 489         int ret;
 490
 491         sout = container_of(td_write, struct ctf_text_stream_pos,
 492                         trace_descriptor);
 493
 494         begin_pos.type = BT_SEEK_BEGIN;
 495         iter = bt_iter_create(ctx, &begin_pos, NULL);
 496         if (!iter) {
 497                 ret = -1;
 498                 goto error_iter;
 499         }
 500         while (bt_iter_read_event(iter, &stream, &event) == 0) {
 501                 ret = sout->parent.event_cb(&sout->parent, stream);
 502                 if (ret) {
 503                         fprintf(stderr, "[error] Writing event failed.\n");
 504                         goto end;
 505                 }
 506                 ret = bt_iter_next(iter);
 507                 if (ret < 0)
 508                         goto end;
 509         }
 510         ret = 0;
 511
 512 end:
 513         bt_iter_destroy(iter);
 514 error_iter:
 515         return ret;
 516 }
 517
 518
 519 /*
 520  * traverse_dir() is the callback functiion for File Tree Walk (nftw).
 521  * it receives the path of the current entry (file, dir, link..etc) with
 522  * a flag to indicate the type of the entry.
 523  * if the entry being visited is a directory and contains a metadata file,
 524  * then open it for reading and save a trace_descriptor to that directory
 525  * in the read trace collection.
 526  */
 527 static int traverse_dir(const char *fpath, const struct stat *sb,
 528                         int tflag, struct FTW *ftwbuf)
 529 {
 530         int dirfd;
 531         int fd;
 532         struct trace_descriptor *td_read;
 533         int ret;
 534
 535         if (tflag != FTW_D)
 536                 return 0;
 537         dirfd = open(fpath, 0);
 538         if (dirfd < 0) {
 539                 fprintf(stderr, "[error] unable to open trace "
 540                         "directory file descriptor.\n");
 541                 return -1;
 542         }
 543         fd = openat(dirfd, "metadata", O_RDONLY);
 544         if (fd < 0) {
 545                 close(dirfd);
 546         } else {
 547                 close(fd);
 548                 close(dirfd);
 549                 td_read = fmt_read->open_trace(opt_input_path,
 550                                 fpath, O_RDONLY, ctf_move_pos_slow,
 551                                 NULL);
 552                 if (!td_read) {
 553                         fprintf(stderr, "Error opening trace \"%s\" "
 554                                         "for reading.\n\n", fpath);
 555                         return -1;      /* error */
 556                 }
 557                 ret = trace_collection_add(&trace_collection_read, td_read);
 558                 if (ret) {
 559                         return -1;
 560                 }
 561         }
 562         return 0;       /* success */
 563 }
 564
 565 int main(int argc, char **argv)
 566 {
 567         int ret;
 568         struct format *fmt_write;
 569         struct trace_descriptor *td_write;
 570         struct bt_context *ctx;
 571
 572         ret = parse_options(argc, argv);
 573         if (ret < 0) {
 574                 fprintf(stderr, "Error parsing options.\n\n");
 575                 usage(stderr);
 576                 exit(EXIT_FAILURE);
 577         } else if (ret > 0) {
 578                 exit(EXIT_SUCCESS);
 579         }
 580         printf_verbose("Verbose mode active.\n");
 581         printf_debug("Debug mode active.\n");
 582
 583         if (opt_input_format)
 584                 strlower(opt_input_format);
 585         if (opt_output_format)
 586                 strlower(opt_output_format);
 587
 588         printf_verbose("Converting from directory: %s\n", opt_input_path);
 589         printf_verbose("Converting from format: %s\n",
 590                 opt_input_format ? : "ctf <default>");
 591         printf_verbose("Converting to directory: %s\n",
 592                 opt_output_path ? : "<stdout>");
 593         printf_verbose("Converting to format: %s\n",
 594                 opt_output_format ? : "text <default>");
 595
 596         if (!opt_input_format)
 597                 opt_input_format = "ctf";
 598         if (!opt_output_format)
 599                 opt_output_format = "text";
 600         fmt_read = bt_lookup_format(g_quark_from_static_string(opt_input_format));
 601         if (!fmt_read) {
 602                 fprintf(stderr, "[error] Format \"%s\" is not supported.\n\n",
 603                         opt_input_format);
 604                 exit(EXIT_FAILURE);
 605         }
 606         fmt_write = bt_lookup_format(g_quark_from_static_string(opt_output_format));
 607         if (!fmt_write) {
 608                 fprintf(stderr, "[error] format \"%s\" is not supported.\n\n",
 609                         opt_output_format);
 610                 exit(EXIT_FAILURE);
 611         }
 612
 613         /*
 614          * pass the input path to nftw() .
 615          * specify traverse_dir() as the callback function.
 616          * depth = 10 which is the max number of file descriptors
 617          * that nftw() can open at a given time.
 618          * flags = 0  check nftw documentation for more info .
 619          */
 620         init_trace_collection(&trace_collection_read);
 621         ret = nftw(opt_input_path, traverse_dir, 10, 0);
 622         if (ret != 0) {
 623                 fprintf(stderr, "[error] opening trace \"%s\" for reading.\n\n",
 624                         opt_input_path);
 625                 goto error_td_read;
 626         }
 627         if (trace_collection_read.array->len == 0) {
 628                 fprintf(stderr, "[warning] no metadata file was found."
 629                                                 " no output was generated\n");
 630                 return 0;
 631         }
 632         ctx = bt_context_create(&trace_collection_read);
 633         if (!ctx) {
 634                 fprintf(stderr, "Error allocating a new context\n");
 635                 goto error_td_read;
 636         }
 637         td_write = fmt_write->open_trace(NULL, opt_output_path, O_RDWR, NULL, NULL);
 638         if (!td_write) {
 639                 fprintf(stderr, "Error opening trace \"%s\" for writing.\n\n",
 640                         opt_output_path ? : "<none>");
 641                 goto error_td_write;
 642         }
 643
 644         ret = convert_trace(td_write, ctx);
 645         if (ret) {
 646                 fprintf(stderr, "Error printing trace.\n\n");
 647                 goto error_copy_trace;
 648         }
 649
 650         fmt_write->close_trace(td_write);
 651         finalize_trace_collection(&trace_collection_read);
 652         bt_context_destroy(ctx);
 653         printf_verbose("finished converting. Output written to:\n%s\n",
 654                         opt_output_path ? : "<stdout>");
 655         exit(EXIT_SUCCESS);
 656
 657         /* Error handling */
 658 error_copy_trace:
 659         fmt_write->close_trace(td_write);
 660 error_td_write:
 661         finalize_trace_collection(&trace_collection_read);
 662 error_td_read:
 663         exit(EXIT_FAILURE);
 664 }