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