tools/perf/perf.c

   1 /*
   2  * perf.c
   3  *
   4  * Performance analysis utility.
   5  *
   6  * This is the main hub from which the sub-commands (perf stat,
   7  * perf top, perf record, perf report, etc.) are started.
   8  */
   9 #include "builtin.h"
  10
  11 #include "util/exec_cmd.h"
  12 #include "util/cache.h"
  13 #include "util/quote.h"
  14 #include "util/run-command.h"
  15 #include "util/parse-events.h"
  16 #include "util/string.h"
  17 #include "util/debugfs.h"
  18
  19 bool use_browser;
  20
  21 const char perf_usage_string[] =
  22         "perf [--version] [--help] COMMAND [ARGS]";
  23
  24 const char perf_more_info_string[] =
  25         "See 'perf help COMMAND' for more information on a specific command.";
  26
  27 static int use_pager = -1;
  28 struct pager_config {
  29         const char *cmd;
  30         int val;
  31 };
  32
  33 static char debugfs_mntpt[MAXPATHLEN];
  34
  35 static int pager_command_config(const char *var, const char *value, void *data)
  36 {
  37         struct pager_config *c = data;
  38         if (!prefixcmp(var, "pager.") && !strcmp(var + 6, c->cmd))
  39                 c->val = perf_config_bool(var, value);
  40         return 0;
  41 }
  42
  43 /* returns 0 for "no pager", 1 for "use pager", and -1 for "not specified" */
  44 int check_pager_config(const char *cmd)
  45 {
  46         struct pager_config c;
  47         c.cmd = cmd;
  48         c.val = -1;
  49         perf_config(pager_command_config, &c);
  50         return c.val;
  51 }
  52
  53 static void commit_pager_choice(void)
  54 {
  55         switch (use_pager) {
  56         case 0:
  57                 setenv("PERF_PAGER", "cat", 1);
  58                 break;
  59         case 1:
  60                 /* setup_pager(); */
  61                 break;
  62         default:
  63                 break;
  64         }
  65 }
  66
  67 static void set_debugfs_path(void)
  68 {
  69         char *path;
  70
  71         path = getenv(PERF_DEBUGFS_ENVIRONMENT);
  72         snprintf(debugfs_path, MAXPATHLEN, "%s/%s", path ?: debugfs_mntpt,
  73                  "tracing/events");
  74 }
  75
  76 static int handle_options(const char ***argv, int *argc, int *envchanged)
  77 {
  78         int handled = 0;
  79
  80         while (*argc > 0) {
  81                 const char *cmd = (*argv)[0];
  82                 if (cmd[0] != '-')
  83                         break;
  84
  85                 /*
  86                  * For legacy reasons, the "version" and "help"
  87                  * commands can be written with "--" prepended
  88                  * to make them look like flags.
  89                  */
  90                 if (!strcmp(cmd, "--help") || !strcmp(cmd, "--version"))
  91                         break;
  92
  93                 /*
  94                  * Check remaining flags.
  95                  */
  96                 if (!prefixcmp(cmd, CMD_EXEC_PATH)) {
  97                         cmd += strlen(CMD_EXEC_PATH);
  98                         if (*cmd == '=')
  99                                 perf_set_argv_exec_path(cmd + 1);
 100                         else {
 101                                 puts(perf_exec_path());
 102                                 exit(0);
 103                         }
 104                 } else if (!strcmp(cmd, "--html-path")) {
 105                         puts(system_path(PERF_HTML_PATH));
 106                         exit(0);
 107                 } else if (!strcmp(cmd, "-p") || !strcmp(cmd, "--paginate")) {
 108                         use_pager = 1;
 109                 } else if (!strcmp(cmd, "--no-pager")) {
 110                         use_pager = 0;
 111                         if (envchanged)
 112                                 *envchanged = 1;
 113                 } else if (!strcmp(cmd, "--perf-dir")) {
 114                         if (*argc < 2) {
 115                                 fprintf(stderr, "No directory given for --perf-dir.\n");
 116                                 usage(perf_usage_string);
 117                         }
 118                         setenv(PERF_DIR_ENVIRONMENT, (*argv)[1], 1);
 119                         if (envchanged)
 120                                 *envchanged = 1;
 121                         (*argv)++;
 122                         (*argc)--;
 123                         handled++;
 124                 } else if (!prefixcmp(cmd, CMD_PERF_DIR)) {
 125                         setenv(PERF_DIR_ENVIRONMENT, cmd + strlen(CMD_PERF_DIR), 1);
 126                         if (envchanged)
 127                                 *envchanged = 1;
 128                 } else if (!strcmp(cmd, "--work-tree")) {
 129                         if (*argc < 2) {
 130                                 fprintf(stderr, "No directory given for --work-tree.\n");
 131                                 usage(perf_usage_string);
 132                         }
 133                         setenv(PERF_WORK_TREE_ENVIRONMENT, (*argv)[1], 1);
 134                         if (envchanged)
 135                                 *envchanged = 1;
 136                         (*argv)++;
 137                         (*argc)--;
 138                 } else if (!prefixcmp(cmd, CMD_WORK_TREE)) {
 139                         setenv(PERF_WORK_TREE_ENVIRONMENT, cmd + strlen(CMD_WORK_TREE), 1);
 140                         if (envchanged)
 141                                 *envchanged = 1;
 142                 } else if (!strcmp(cmd, "--debugfs-dir")) {
 143                         if (*argc < 2) {
 144                                 fprintf(stderr, "No directory given for --debugfs-dir.\n");
 145                                 usage(perf_usage_string);
 146                         }
 147                         strncpy(debugfs_mntpt, (*argv)[1], MAXPATHLEN);
 148                         debugfs_mntpt[MAXPATHLEN - 1] = '\0';
 149                         if (envchanged)
 150                                 *envchanged = 1;
 151                         (*argv)++;
 152                         (*argc)--;
 153                 } else if (!prefixcmp(cmd, CMD_DEBUGFS_DIR)) {
 154                         strncpy(debugfs_mntpt, cmd + strlen(CMD_DEBUGFS_DIR), MAXPATHLEN);
 155                         debugfs_mntpt[MAXPATHLEN - 1] = '\0';
 156                         if (envchanged)
 157                                 *envchanged = 1;
 158                 } else {
 159                         fprintf(stderr, "Unknown option: %s\n", cmd);
 160                         usage(perf_usage_string);
 161                 }
 162
 163                 (*argv)++;
 164                 (*argc)--;
 165                 handled++;
 166         }
 167         return handled;
 168 }
 169
 170 static int handle_alias(int *argcp, const char ***argv)
 171 {
 172         int envchanged = 0, ret = 0, saved_errno = errno;
 173         int count, option_count;
 174         const char **new_argv;
 175         const char *alias_command;
 176         char *alias_string;
 177
 178         alias_command = (*argv)[0];
 179         alias_string = alias_lookup(alias_command);
 180         if (alias_string) {
 181                 if (alias_string[0] == '!') {
 182                         if (*argcp > 1) {
 183                                 struct strbuf buf;
 184
 185                                 strbuf_init(&buf, PATH_MAX);
 186                                 strbuf_addstr(&buf, alias_string);
 187                                 sq_quote_argv(&buf, (*argv) + 1, PATH_MAX);
 188                                 free(alias_string);
 189                                 alias_string = buf.buf;
 190                         }
 191                         ret = system(alias_string + 1);
 192                         if (ret >= 0 && WIFEXITED(ret) &&
 193                             WEXITSTATUS(ret) != 127)
 194                                 exit(WEXITSTATUS(ret));
 195                         die("Failed to run '%s' when expanding alias '%s'",
 196                             alias_string + 1, alias_command);
 197                 }
 198                 count = split_cmdline(alias_string, &new_argv);
 199                 if (count < 0)
 200                         die("Bad alias.%s string", alias_command);
 201                 option_count = handle_options(&new_argv, &count, &envchanged);
 202                 if (envchanged)
 203                         die("alias '%s' changes environment variables\n"
 204                                  "You can use '!perf' in the alias to do this.",
 205                                  alias_command);
 206                 memmove(new_argv - option_count, new_argv,
 207                                 count * sizeof(char *));
 208                 new_argv -= option_count;
 209
 210                 if (count < 1)
 211                         die("empty alias for %s", alias_command);
 212
 213                 if (!strcmp(alias_command, new_argv[0]))
 214                         die("recursive alias: %s", alias_command);
 215
 216                 new_argv = realloc(new_argv, sizeof(char *) *
 217                                     (count + *argcp + 1));
 218                 /* insert after command name */
 219                 memcpy(new_argv + count, *argv + 1, sizeof(char *) * *argcp);
 220                 new_argv[count + *argcp] = NULL;
 221
 222                 *argv = new_argv;
 223                 *argcp += count - 1;
 224
 225                 ret = 1;
 226         }
 227
 228         errno = saved_errno;
 229
 230         return ret;
 231 }
 232
 233 const char perf_version_string[] = PERF_VERSION;
 234
 235 #define RUN_SETUP       (1<<0)
 236 #define USE_PAGER       (1<<1)
 237 /*
 238  * require working tree to be present -- anything uses this needs
 239  * RUN_SETUP for reading from the configuration file.
 240  */
 241 #define NEED_WORK_TREE  (1<<2)
 242
 243 struct cmd_struct {
 244         const char *cmd;
 245         int (*fn)(int, const char **, const char *);
 246         int option;
 247 };
 248
 249 static int run_builtin(struct cmd_struct *p, int argc, const char **argv)
 250 {
 251         int status;
 252         struct stat st;
 253         const char *prefix;
 254
 255         prefix = NULL;
 256         if (p->option & RUN_SETUP)
 257                 prefix = NULL; /* setup_perf_directory(); */
 258
 259         if (use_pager == -1 && p->option & RUN_SETUP)
 260                 use_pager = check_pager_config(p->cmd);
 261         if (use_pager == -1 && p->option & USE_PAGER)
 262                 use_pager = 1;
 263         commit_pager_choice();
 264         set_debugfs_path();
 265
 266         status = p->fn(argc, argv, prefix);
 267         if (status)
 268                 return status & 0xff;
 269
 270         exit_browser();
 271
 272         /* Somebody closed stdout? */
 273         if (fstat(fileno(stdout), &st))
 274                 return 0;
 275         /* Ignore write errors for pipes and sockets.. */
 276         if (S_ISFIFO(st.st_mode) || S_ISSOCK(st.st_mode))
 277                 return 0;
 278
 279         /* Check for ENOSPC and EIO errors.. */
 280         if (fflush(stdout))
 281                 die("write failure on standard output: %s", strerror(errno));
 282         if (ferror(stdout))
 283                 die("unknown write failure on standard output");
 284         if (fclose(stdout))
 285                 die("close failed on standard output: %s", strerror(errno));
 286         return 0;
 287 }
 288
 289 static void handle_internal_command(int argc, const char **argv)
 290 {
 291         const char *cmd = argv[0];
 292         static struct cmd_struct commands[] = {
 293                 { "buildid-cache", cmd_buildid_cache, 0 },
 294                 { "buildid-list", cmd_buildid_list, 0 },
 295                 { "diff",       cmd_diff,       0 },
 296                 { "help",       cmd_help,       0 },
 297                 { "list",       cmd_list,       0 },
 298                 { "record",     cmd_record,     0 },
 299                 { "report",     cmd_report,     0 },
 300                 { "bench",      cmd_bench,      0 },
 301                 { "stat",       cmd_stat,       0 },
 302                 { "timechart",  cmd_timechart,  0 },
 303                 { "top",        cmd_top,        0 },
 304                 { "annotate",   cmd_annotate,   0 },
 305                 { "version",    cmd_version,    0 },
 306                 { "trace",      cmd_trace,      0 },
 307                 { "sched",      cmd_sched,      0 },
 308                 { "probe",      cmd_probe,      0 },
 309                 { "kmem",       cmd_kmem,       0 },
 310                 { "lock",       cmd_lock,       0 },
 311         };
 312         unsigned int i;
 313         static const char ext[] = STRIP_EXTENSION;
 314
 315         if (sizeof(ext) > 1) {
 316                 i = strlen(argv[0]) - strlen(ext);
 317                 if (i > 0 && !strcmp(argv[0] + i, ext)) {
 318                         char *argv0 = strdup(argv[0]);
 319                         argv[0] = cmd = argv0;
 320                         argv0[i] = '\0';
 321                 }
 322         }
 323
 324         /* Turn "perf cmd --help" into "perf help cmd" */
 325         if (argc > 1 && !strcmp(argv[1], "--help")) {
 326                 argv[1] = argv[0];
 327                 argv[0] = cmd = "help";
 328         }
 329
 330         for (i = 0; i < ARRAY_SIZE(commands); i++) {
 331                 struct cmd_struct *p = commands+i;
 332                 if (strcmp(p->cmd, cmd))
 333                         continue;
 334                 exit(run_builtin(p, argc, argv));
 335         }
 336 }
 337
 338 static void execv_dashed_external(const char **argv)
 339 {
 340         struct strbuf cmd = STRBUF_INIT;
 341         const char *tmp;
 342         int status;
 343
 344         strbuf_addf(&cmd, "perf-%s", argv[0]);
 345
 346         /*
 347          * argv[0] must be the perf command, but the argv array
 348          * belongs to the caller, and may be reused in
 349          * subsequent loop iterations. Save argv[0] and
 350          * restore it on error.
 351          */
 352         tmp = argv[0];
 353         argv[0] = cmd.buf;
 354
 355         /*
 356          * if we fail because the command is not found, it is
 357          * OK to return. Otherwise, we just pass along the status code.
 358          */
 359         status = run_command_v_opt(argv, 0);
 360         if (status != -ERR_RUN_COMMAND_EXEC) {
 361                 if (IS_RUN_COMMAND_ERR(status))
 362                         die("unable to run '%s'", argv[0]);
 363                 exit(-status);
 364         }
 365         errno = ENOENT; /* as if we called execvp */
 366
 367         argv[0] = tmp;
 368
 369         strbuf_release(&cmd);
 370 }
 371
 372 static int run_argv(int *argcp, const char ***argv)
 373 {
 374         int done_alias = 0;
 375
 376         while (1) {
 377                 /* See if it's an internal command */
 378                 handle_internal_command(*argcp, *argv);
 379
 380                 /* .. then try the external ones */
 381                 execv_dashed_external(*argv);
 382
 383                 /* It could be an alias -- this works around the insanity
 384                  * of overriding "perf log" with "perf show" by having
 385                  * alias.log = show
 386                  */
 387                 if (done_alias || !handle_alias(argcp, argv))
 388                         break;
 389                 done_alias = 1;
 390         }
 391
 392         return done_alias;
 393 }
 394
 395 /* mini /proc/mounts parser: searching for "^blah /mount/point debugfs" */
 396 static void get_debugfs_mntpt(void)
 397 {
 398         const char *path = debugfs_mount(NULL);
 399
 400         if (path)
 401                 strncpy(debugfs_mntpt, path, sizeof(debugfs_mntpt));
 402         else
 403                 debugfs_mntpt[0] = '\0';
 404 }
 405
 406 int main(int argc, const char **argv)
 407 {
 408         const char *cmd;
 409
 410         cmd = perf_extract_argv0_path(argv[0]);
 411         if (!cmd)
 412                 cmd = "perf-help";
 413         /* get debugfs mount point from /proc/mounts */
 414         get_debugfs_mntpt();
 415         /*
 416          * "perf-xxxx" is the same as "perf xxxx", but we obviously:
 417          *
 418          *  - cannot take flags in between the "perf" and the "xxxx".
 419          *  - cannot execute it externally (since it would just do
 420          *    the same thing over again)
 421          *
 422          * So we just directly call the internal command handler, and
 423          * die if that one cannot handle it.
 424          */
 425         if (!prefixcmp(cmd, "perf-")) {
 426                 cmd += 5;
 427                 argv[0] = cmd;
 428                 handle_internal_command(argc, argv);
 429                 die("cannot handle %s internally", cmd);
 430         }
 431
 432         /* Look for flags.. */
 433         argv++;
 434         argc--;
 435         handle_options(&argv, &argc, NULL);
 436         commit_pager_choice();
 437         set_debugfs_path();
 438         if (argc > 0) {
 439                 if (!prefixcmp(argv[0], "--"))
 440                         argv[0] += 2;
 441         } else {
 442                 /* The user didn't specify a command; give them help */
 443                 printf("\n usage: %s\n\n", perf_usage_string);
 444                 list_common_cmds_help();
 445                 printf("\n %s\n\n", perf_more_info_string);
 446                 exit(1);
 447         }
 448         cmd = argv[0];
 449
 450         /*
 451          * We use PATH to find perf commands, but we prepend some higher
 452          * precedence paths: the "--exec-path" option, the PERF_EXEC_PATH
 453          * environment, and the $(perfexecdir) from the Makefile at build
 454          * time.
 455          */
 456         setup_path();
 457
 458         while (1) {
 459                 static int done_help;
 460                 static int was_alias;
 461
 462                 was_alias = run_argv(&argc, &argv);
 463                 if (errno != ENOENT)
 464                         break;
 465
 466                 if (was_alias) {
 467                         fprintf(stderr, "Expansion of alias '%s' failed; "
 468                                 "'%s' is not a perf-command\n",
 469                                 cmd, argv[0]);
 470                         exit(1);
 471                 }
 472                 if (!done_help) {
 473                         cmd = argv[0] = help_unknown_cmd(cmd);
 474                         done_help = 1;
 475                 } else
 476                         break;
 477         }
 478
 479         fprintf(stderr, "Failed to run command '%s': %s\n",
 480                 cmd, strerror(errno));
 481
 482         return 1;
 483 }