tools/perf/util/config.c

   1 /*
   2  * config.c
   3  *
   4  * Helper functions for parsing config items.
   5  * Originally copied from GIT source.
   6  *
   7  * Copyright (C) Linus Torvalds, 2005
   8  * Copyright (C) Johannes Schindelin, 2005
   9  *
  10  */
  11 #include "util.h"
  12 #include "cache.h"
  13 #include "exec_cmd.h"
  14 #include "util/hist.h"  /* perf_hist_config */
  15 #include "util/llvm-utils.h"   /* perf_llvm_config */
  16
  17 #define MAXNAME (256)
  18
  19 #define DEBUG_CACHE_DIR ".debug"
  20
  21
  22 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
  23
  24 static FILE *config_file;
  25 static const char *config_file_name;
  26 static int config_linenr;
  27 static int config_file_eof;
  28
  29 static const char *config_exclusive_filename;
  30
  31 static int get_next_char(void)
  32 {
  33         int c;
  34         FILE *f;
  35
  36         c = '\n';
  37         if ((f = config_file) != NULL) {
  38                 c = fgetc(f);
  39                 if (c == '\r') {
  40                         /* DOS like systems */
  41                         c = fgetc(f);
  42                         if (c != '\n') {
  43                                 ungetc(c, f);
  44                                 c = '\r';
  45                         }
  46                 }
  47                 if (c == '\n')
  48                         config_linenr++;
  49                 if (c == EOF) {
  50                         config_file_eof = 1;
  51                         c = '\n';
  52                 }
  53         }
  54         return c;
  55 }
  56
  57 static char *parse_value(void)
  58 {
  59         static char value[1024];
  60         int quote = 0, comment = 0, space = 0;
  61         size_t len = 0;
  62
  63         for (;;) {
  64                 int c = get_next_char();
  65
  66                 if (len >= sizeof(value) - 1)
  67                         return NULL;
  68                 if (c == '\n') {
  69                         if (quote)
  70                                 return NULL;
  71                         value[len] = 0;
  72                         return value;
  73                 }
  74                 if (comment)
  75                         continue;
  76                 if (isspace(c) && !quote) {
  77                         space = 1;
  78                         continue;
  79                 }
  80                 if (!quote) {
  81                         if (c == ';' || c == '#') {
  82                                 comment = 1;
  83                                 continue;
  84                         }
  85                 }
  86                 if (space) {
  87                         if (len)
  88                                 value[len++] = ' ';
  89                         space = 0;
  90                 }
  91                 if (c == '\\') {
  92                         c = get_next_char();
  93                         switch (c) {
  94                         case '\n':
  95                                 continue;
  96                         case 't':
  97                                 c = '\t';
  98                                 break;
  99                         case 'b':
 100                                 c = '\b';
 101                                 break;
 102                         case 'n':
 103                                 c = '\n';
 104                                 break;
 105                         /* Some characters escape as themselves */
 106                         case '\\': case '"':
 107                                 break;
 108                         /* Reject unknown escape sequences */
 109                         default:
 110                                 return NULL;
 111                         }
 112                         value[len++] = c;
 113                         continue;
 114                 }
 115                 if (c == '"') {
 116                         quote = 1-quote;
 117                         continue;
 118                 }
 119                 value[len++] = c;
 120         }
 121 }
 122
 123 static inline int iskeychar(int c)
 124 {
 125         return isalnum(c) || c == '-' || c == '_';
 126 }
 127
 128 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 129 {
 130         int c;
 131         char *value;
 132
 133         /* Get the full name */
 134         for (;;) {
 135                 c = get_next_char();
 136                 if (config_file_eof)
 137                         break;
 138                 if (!iskeychar(c))
 139                         break;
 140                 name[len++] = c;
 141                 if (len >= MAXNAME)
 142                         return -1;
 143         }
 144         name[len] = 0;
 145         while (c == ' ' || c == '\t')
 146                 c = get_next_char();
 147
 148         value = NULL;
 149         if (c != '\n') {
 150                 if (c != '=')
 151                         return -1;
 152                 value = parse_value();
 153                 if (!value)
 154                         return -1;
 155         }
 156         return fn(name, value, data);
 157 }
 158
 159 static int get_extended_base_var(char *name, int baselen, int c)
 160 {
 161         do {
 162                 if (c == '\n')
 163                         return -1;
 164                 c = get_next_char();
 165         } while (isspace(c));
 166
 167         /* We require the format to be '[base "extension"]' */
 168         if (c != '"')
 169                 return -1;
 170         name[baselen++] = '.';
 171
 172         for (;;) {
 173                 int ch = get_next_char();
 174
 175                 if (ch == '\n')
 176                         return -1;
 177                 if (ch == '"')
 178                         break;
 179                 if (ch == '\\') {
 180                         ch = get_next_char();
 181                         if (ch == '\n')
 182                                 return -1;
 183                 }
 184                 name[baselen++] = ch;
 185                 if (baselen > MAXNAME / 2)
 186                         return -1;
 187         }
 188
 189         /* Final ']' */
 190         if (get_next_char() != ']')
 191                 return -1;
 192         return baselen;
 193 }
 194
 195 static int get_base_var(char *name)
 196 {
 197         int baselen = 0;
 198
 199         for (;;) {
 200                 int c = get_next_char();
 201                 if (config_file_eof)
 202                         return -1;
 203                 if (c == ']')
 204                         return baselen;
 205                 if (isspace(c))
 206                         return get_extended_base_var(name, baselen, c);
 207                 if (!iskeychar(c) && c != '.')
 208                         return -1;
 209                 if (baselen > MAXNAME / 2)
 210                         return -1;
 211                 name[baselen++] = tolower(c);
 212         }
 213 }
 214
 215 static int perf_parse_file(config_fn_t fn, void *data)
 216 {
 217         int comment = 0;
 218         int baselen = 0;
 219         static char var[MAXNAME];
 220
 221         /* U+FEFF Byte Order Mark in UTF8 */
 222         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 223         const unsigned char *bomptr = utf8_bom;
 224
 225         for (;;) {
 226                 int line, c = get_next_char();
 227
 228                 if (bomptr && *bomptr) {
 229                         /* We are at the file beginning; skip UTF8-encoded BOM
 230                          * if present. Sane editors won't put this in on their
 231                          * own, but e.g. Windows Notepad will do it happily. */
 232                         if ((unsigned char) c == *bomptr) {
 233                                 bomptr++;
 234                                 continue;
 235                         } else {
 236                                 /* Do not tolerate partial BOM. */
 237                                 if (bomptr != utf8_bom)
 238                                         break;
 239                                 /* No BOM at file beginning. Cool. */
 240                                 bomptr = NULL;
 241                         }
 242                 }
 243                 if (c == '\n') {
 244                         if (config_file_eof)
 245                                 return 0;
 246                         comment = 0;
 247                         continue;
 248                 }
 249                 if (comment || isspace(c))
 250                         continue;
 251                 if (c == '#' || c == ';') {
 252                         comment = 1;
 253                         continue;
 254                 }
 255                 if (c == '[') {
 256                         baselen = get_base_var(var);
 257                         if (baselen <= 0)
 258                                 break;
 259                         var[baselen++] = '.';
 260                         var[baselen] = 0;
 261                         continue;
 262                 }
 263                 if (!isalpha(c))
 264                         break;
 265                 var[baselen] = tolower(c);
 266
 267                 /*
 268                  * The get_value function might or might not reach the '\n',
 269                  * so saving the current line number for error reporting.
 270                  */
 271                 line = config_linenr;
 272                 if (get_value(fn, data, var, baselen+1) < 0) {
 273                         config_linenr = line;
 274                         break;
 275                 }
 276         }
 277         die("bad config file line %d in %s", config_linenr, config_file_name);
 278 }
 279
 280 static int parse_unit_factor(const char *end, unsigned long *val)
 281 {
 282         if (!*end)
 283                 return 1;
 284         else if (!strcasecmp(end, "k")) {
 285                 *val *= 1024;
 286                 return 1;
 287         }
 288         else if (!strcasecmp(end, "m")) {
 289                 *val *= 1024 * 1024;
 290                 return 1;
 291         }
 292         else if (!strcasecmp(end, "g")) {
 293                 *val *= 1024 * 1024 * 1024;
 294                 return 1;
 295         }
 296         return 0;
 297 }
 298
 299 static int perf_parse_llong(const char *value, long long *ret)
 300 {
 301         if (value && *value) {
 302                 char *end;
 303                 long long val = strtoll(value, &end, 0);
 304                 unsigned long factor = 1;
 305
 306                 if (!parse_unit_factor(end, &factor))
 307                         return 0;
 308                 *ret = val * factor;
 309                 return 1;
 310         }
 311         return 0;
 312 }
 313
 314 static int perf_parse_long(const char *value, long *ret)
 315 {
 316         if (value && *value) {
 317                 char *end;
 318                 long val = strtol(value, &end, 0);
 319                 unsigned long factor = 1;
 320                 if (!parse_unit_factor(end, &factor))
 321                         return 0;
 322                 *ret = val * factor;
 323                 return 1;
 324         }
 325         return 0;
 326 }
 327
 328 static void die_bad_config(const char *name)
 329 {
 330         if (config_file_name)
 331                 die("bad config value for '%s' in %s", name, config_file_name);
 332         die("bad config value for '%s'", name);
 333 }
 334
 335 u64 perf_config_u64(const char *name, const char *value)
 336 {
 337         long long ret = 0;
 338
 339         if (!perf_parse_llong(value, &ret))
 340                 die_bad_config(name);
 341         return (u64) ret;
 342 }
 343
 344 int perf_config_int(const char *name, const char *value)
 345 {
 346         long ret = 0;
 347         if (!perf_parse_long(value, &ret))
 348                 die_bad_config(name);
 349         return ret;
 350 }
 351
 352 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
 353 {
 354         *is_bool = 1;
 355         if (!value)
 356                 return 1;
 357         if (!*value)
 358                 return 0;
 359         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 360                 return 1;
 361         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 362                 return 0;
 363         *is_bool = 0;
 364         return perf_config_int(name, value);
 365 }
 366
 367 int perf_config_bool(const char *name, const char *value)
 368 {
 369         int discard;
 370         return !!perf_config_bool_or_int(name, value, &discard);
 371 }
 372
 373 const char *perf_config_dirname(const char *name, const char *value)
 374 {
 375         if (!name)
 376                 return NULL;
 377         return value;
 378 }
 379
 380 static int perf_default_core_config(const char *var __maybe_unused,
 381                                     const char *value __maybe_unused)
 382 {
 383         /* Add other config variables here. */
 384         return 0;
 385 }
 386
 387 static int perf_ui_config(const char *var, const char *value)
 388 {
 389         /* Add other config variables here. */
 390         if (!strcmp(var, "ui.show-headers")) {
 391                 symbol_conf.show_hist_headers = perf_config_bool(var, value);
 392                 return 0;
 393         }
 394         return 0;
 395 }
 396
 397 int perf_default_config(const char *var, const char *value,
 398                         void *dummy __maybe_unused)
 399 {
 400         if (!prefixcmp(var, "core."))
 401                 return perf_default_core_config(var, value);
 402
 403         if (!prefixcmp(var, "hist."))
 404                 return perf_hist_config(var, value);
 405
 406         if (!prefixcmp(var, "ui."))
 407                 return perf_ui_config(var, value);
 408
 409         if (!prefixcmp(var, "call-graph."))
 410                 return perf_callchain_config(var, value);
 411
 412         if (!prefixcmp(var, "llvm."))
 413                 return perf_llvm_config(var, value);
 414
 415         /* Add other config variables here. */
 416         return 0;
 417 }
 418
 419 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
 420 {
 421         int ret;
 422         FILE *f = fopen(filename, "r");
 423
 424         ret = -1;
 425         if (f) {
 426                 config_file = f;
 427                 config_file_name = filename;
 428                 config_linenr = 1;
 429                 config_file_eof = 0;
 430                 ret = perf_parse_file(fn, data);
 431                 fclose(f);
 432                 config_file_name = NULL;
 433         }
 434         return ret;
 435 }
 436
 437 static const char *perf_etc_perfconfig(void)
 438 {
 439         static const char *system_wide;
 440         if (!system_wide)
 441                 system_wide = system_path(ETC_PERFCONFIG);
 442         return system_wide;
 443 }
 444
 445 static int perf_env_bool(const char *k, int def)
 446 {
 447         const char *v = getenv(k);
 448         return v ? perf_config_bool(k, v) : def;
 449 }
 450
 451 static int perf_config_system(void)
 452 {
 453         return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
 454 }
 455
 456 static int perf_config_global(void)
 457 {
 458         return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 459 }
 460
 461 int perf_config(config_fn_t fn, void *data)
 462 {
 463         int ret = 0, found = 0;
 464         const char *home = NULL;
 465
 466         /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
 467         if (config_exclusive_filename)
 468                 return perf_config_from_file(fn, config_exclusive_filename, data);
 469         if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
 470                 ret += perf_config_from_file(fn, perf_etc_perfconfig(),
 471                                             data);
 472                 found += 1;
 473         }
 474
 475         home = getenv("HOME");
 476         if (perf_config_global() && home) {
 477                 char *user_config = strdup(mkpath("%s/.perfconfig", home));
 478                 struct stat st;
 479
 480                 if (user_config == NULL) {
 481                         warning("Not enough memory to process %s/.perfconfig, "
 482                                 "ignoring it.", home);
 483                         goto out;
 484                 }
 485
 486                 if (stat(user_config, &st) < 0)
 487                         goto out_free;
 488
 489                 if (st.st_uid && (st.st_uid != geteuid())) {
 490                         warning("File %s not owned by current user or root, "
 491                                 "ignoring it.", user_config);
 492                         goto out_free;
 493                 }
 494
 495                 if (!st.st_size)
 496                         goto out_free;
 497
 498                 ret += perf_config_from_file(fn, user_config, data);
 499                 found += 1;
 500 out_free:
 501                 free(user_config);
 502         }
 503 out:
 504         if (found == 0)
 505                 return -1;
 506         return ret;
 507 }
 508
 509 /*
 510  * Call this to report error for your variable that should not
 511  * get a boolean value (i.e. "[my] var" means "true").
 512  */
 513 int config_error_nonbool(const char *var)
 514 {
 515         return error("Missing value for '%s'", var);
 516 }
 517
 518 struct buildid_dir_config {
 519         char *dir;
 520 };
 521
 522 static int buildid_dir_command_config(const char *var, const char *value,
 523                                       void *data)
 524 {
 525         struct buildid_dir_config *c = data;
 526         const char *v;
 527
 528         /* same dir for all commands */
 529         if (!strcmp(var, "buildid.dir")) {
 530                 v = perf_config_dirname(var, value);
 531                 if (!v)
 532                         return -1;
 533                 strncpy(c->dir, v, MAXPATHLEN-1);
 534                 c->dir[MAXPATHLEN-1] = '\0';
 535         }
 536         return 0;
 537 }
 538
 539 static void check_buildid_dir_config(void)
 540 {
 541         struct buildid_dir_config c;
 542         c.dir = buildid_dir;
 543         perf_config(buildid_dir_command_config, &c);
 544 }
 545
 546 void set_buildid_dir(const char *dir)
 547 {
 548         if (dir)
 549                 scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
 550
 551         /* try config file */
 552         if (buildid_dir[0] == '\0')
 553                 check_buildid_dir_config();
 554
 555         /* default to $HOME/.debug */
 556         if (buildid_dir[0] == '\0') {
 557                 char *v = getenv("HOME");
 558                 if (v) {
 559                         snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
 560                                  v, DEBUG_CACHE_DIR);
 561                 } else {
 562                         strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
 563                 }
 564                 buildid_dir[MAXPATHLEN-1] = '\0';
 565         }
 566         /* for communicating with external commands */
 567         setenv("PERF_BUILDID_DIR", buildid_dir, 1);
 568 }