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 <subcmd/exec-cmd.h>
  14 #include "util/hist.h"  /* perf_hist_config */
  15 #include "util/llvm-utils.h"   /* perf_llvm_config */
  16 #include "config.h"
  17
  18 #define MAXNAME (256)
  19
  20 #define DEBUG_CACHE_DIR ".debug"
  21
  22
  23 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
  24
  25 static FILE *config_file;
  26 static const char *config_file_name;
  27 static int config_linenr;
  28 static int config_file_eof;
  29 static struct perf_config_set *config_set;
  30
  31 const char *config_exclusive_filename;
  32
  33 static int get_next_char(void)
  34 {
  35         int c;
  36         FILE *f;
  37
  38         c = '\n';
  39         if ((f = config_file) != NULL) {
  40                 c = fgetc(f);
  41                 if (c == '\r') {
  42                         /* DOS like systems */
  43                         c = fgetc(f);
  44                         if (c != '\n') {
  45                                 ungetc(c, f);
  46                                 c = '\r';
  47                         }
  48                 }
  49                 if (c == '\n')
  50                         config_linenr++;
  51                 if (c == EOF) {
  52                         config_file_eof = 1;
  53                         c = '\n';
  54                 }
  55         }
  56         return c;
  57 }
  58
  59 static char *parse_value(void)
  60 {
  61         static char value[1024];
  62         int quote = 0, comment = 0, space = 0;
  63         size_t len = 0;
  64
  65         for (;;) {
  66                 int c = get_next_char();
  67
  68                 if (len >= sizeof(value) - 1)
  69                         return NULL;
  70                 if (c == '\n') {
  71                         if (quote)
  72                                 return NULL;
  73                         value[len] = 0;
  74                         return value;
  75                 }
  76                 if (comment)
  77                         continue;
  78                 if (isspace(c) && !quote) {
  79                         space = 1;
  80                         continue;
  81                 }
  82                 if (!quote) {
  83                         if (c == ';' || c == '#') {
  84                                 comment = 1;
  85                                 continue;
  86                         }
  87                 }
  88                 if (space) {
  89                         if (len)
  90                                 value[len++] = ' ';
  91                         space = 0;
  92                 }
  93                 if (c == '\\') {
  94                         c = get_next_char();
  95                         switch (c) {
  96                         case '\n':
  97                                 continue;
  98                         case 't':
  99                                 c = '\t';
 100                                 break;
 101                         case 'b':
 102                                 c = '\b';
 103                                 break;
 104                         case 'n':
 105                                 c = '\n';
 106                                 break;
 107                         /* Some characters escape as themselves */
 108                         case '\\': case '"':
 109                                 break;
 110                         /* Reject unknown escape sequences */
 111                         default:
 112                                 return NULL;
 113                         }
 114                         value[len++] = c;
 115                         continue;
 116                 }
 117                 if (c == '"') {
 118                         quote = 1-quote;
 119                         continue;
 120                 }
 121                 value[len++] = c;
 122         }
 123 }
 124
 125 static inline int iskeychar(int c)
 126 {
 127         return isalnum(c) || c == '-' || c == '_';
 128 }
 129
 130 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 131 {
 132         int c;
 133         char *value;
 134
 135         /* Get the full name */
 136         for (;;) {
 137                 c = get_next_char();
 138                 if (config_file_eof)
 139                         break;
 140                 if (!iskeychar(c))
 141                         break;
 142                 name[len++] = c;
 143                 if (len >= MAXNAME)
 144                         return -1;
 145         }
 146         name[len] = 0;
 147         while (c == ' ' || c == '\t')
 148                 c = get_next_char();
 149
 150         value = NULL;
 151         if (c != '\n') {
 152                 if (c != '=')
 153                         return -1;
 154                 value = parse_value();
 155                 if (!value)
 156                         return -1;
 157         }
 158         return fn(name, value, data);
 159 }
 160
 161 static int get_extended_base_var(char *name, int baselen, int c)
 162 {
 163         do {
 164                 if (c == '\n')
 165                         return -1;
 166                 c = get_next_char();
 167         } while (isspace(c));
 168
 169         /* We require the format to be '[base "extension"]' */
 170         if (c != '"')
 171                 return -1;
 172         name[baselen++] = '.';
 173
 174         for (;;) {
 175                 int ch = get_next_char();
 176
 177                 if (ch == '\n')
 178                         return -1;
 179                 if (ch == '"')
 180                         break;
 181                 if (ch == '\\') {
 182                         ch = get_next_char();
 183                         if (ch == '\n')
 184                                 return -1;
 185                 }
 186                 name[baselen++] = ch;
 187                 if (baselen > MAXNAME / 2)
 188                         return -1;
 189         }
 190
 191         /* Final ']' */
 192         if (get_next_char() != ']')
 193                 return -1;
 194         return baselen;
 195 }
 196
 197 static int get_base_var(char *name)
 198 {
 199         int baselen = 0;
 200
 201         for (;;) {
 202                 int c = get_next_char();
 203                 if (config_file_eof)
 204                         return -1;
 205                 if (c == ']')
 206                         return baselen;
 207                 if (isspace(c))
 208                         return get_extended_base_var(name, baselen, c);
 209                 if (!iskeychar(c) && c != '.')
 210                         return -1;
 211                 if (baselen > MAXNAME / 2)
 212                         return -1;
 213                 name[baselen++] = tolower(c);
 214         }
 215 }
 216
 217 static int perf_parse_file(config_fn_t fn, void *data)
 218 {
 219         int comment = 0;
 220         int baselen = 0;
 221         static char var[MAXNAME];
 222
 223         /* U+FEFF Byte Order Mark in UTF8 */
 224         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 225         const unsigned char *bomptr = utf8_bom;
 226
 227         for (;;) {
 228                 int line, c = get_next_char();
 229
 230                 if (bomptr && *bomptr) {
 231                         /* We are at the file beginning; skip UTF8-encoded BOM
 232                          * if present. Sane editors won't put this in on their
 233                          * own, but e.g. Windows Notepad will do it happily. */
 234                         if ((unsigned char) c == *bomptr) {
 235                                 bomptr++;
 236                                 continue;
 237                         } else {
 238                                 /* Do not tolerate partial BOM. */
 239                                 if (bomptr != utf8_bom)
 240                                         break;
 241                                 /* No BOM at file beginning. Cool. */
 242                                 bomptr = NULL;
 243                         }
 244                 }
 245                 if (c == '\n') {
 246                         if (config_file_eof)
 247                                 return 0;
 248                         comment = 0;
 249                         continue;
 250                 }
 251                 if (comment || isspace(c))
 252                         continue;
 253                 if (c == '#' || c == ';') {
 254                         comment = 1;
 255                         continue;
 256                 }
 257                 if (c == '[') {
 258                         baselen = get_base_var(var);
 259                         if (baselen <= 0)
 260                                 break;
 261                         var[baselen++] = '.';
 262                         var[baselen] = 0;
 263                         continue;
 264                 }
 265                 if (!isalpha(c))
 266                         break;
 267                 var[baselen] = tolower(c);
 268
 269                 /*
 270                  * The get_value function might or might not reach the '\n',
 271                  * so saving the current line number for error reporting.
 272                  */
 273                 line = config_linenr;
 274                 if (get_value(fn, data, var, baselen+1) < 0) {
 275                         config_linenr = line;
 276                         break;
 277                 }
 278         }
 279         pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
 280         return -1;
 281 }
 282
 283 static int parse_unit_factor(const char *end, unsigned long *val)
 284 {
 285         if (!*end)
 286                 return 1;
 287         else if (!strcasecmp(end, "k")) {
 288                 *val *= 1024;
 289                 return 1;
 290         }
 291         else if (!strcasecmp(end, "m")) {
 292                 *val *= 1024 * 1024;
 293                 return 1;
 294         }
 295         else if (!strcasecmp(end, "g")) {
 296                 *val *= 1024 * 1024 * 1024;
 297                 return 1;
 298         }
 299         return 0;
 300 }
 301
 302 static int perf_parse_llong(const char *value, long long *ret)
 303 {
 304         if (value && *value) {
 305                 char *end;
 306                 long long val = strtoll(value, &end, 0);
 307                 unsigned long factor = 1;
 308
 309                 if (!parse_unit_factor(end, &factor))
 310                         return 0;
 311                 *ret = val * factor;
 312                 return 1;
 313         }
 314         return 0;
 315 }
 316
 317 static int perf_parse_long(const char *value, long *ret)
 318 {
 319         if (value && *value) {
 320                 char *end;
 321                 long val = strtol(value, &end, 0);
 322                 unsigned long factor = 1;
 323                 if (!parse_unit_factor(end, &factor))
 324                         return 0;
 325                 *ret = val * factor;
 326                 return 1;
 327         }
 328         return 0;
 329 }
 330
 331 static void die_bad_config(const char *name)
 332 {
 333         if (config_file_name)
 334                 die("bad config value for '%s' in %s", name, config_file_name);
 335         die("bad config value for '%s'", name);
 336 }
 337
 338 u64 perf_config_u64(const char *name, const char *value)
 339 {
 340         long long ret = 0;
 341
 342         if (!perf_parse_llong(value, &ret))
 343                 die_bad_config(name);
 344         return (u64) ret;
 345 }
 346
 347 int perf_config_int(const char *name, const char *value)
 348 {
 349         long ret = 0;
 350         if (!perf_parse_long(value, &ret))
 351                 die_bad_config(name);
 352         return ret;
 353 }
 354
 355 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
 356 {
 357         *is_bool = 1;
 358         if (!value)
 359                 return 1;
 360         if (!*value)
 361                 return 0;
 362         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 363                 return 1;
 364         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 365                 return 0;
 366         *is_bool = 0;
 367         return perf_config_int(name, value);
 368 }
 369
 370 int perf_config_bool(const char *name, const char *value)
 371 {
 372         int discard;
 373         return !!perf_config_bool_or_int(name, value, &discard);
 374 }
 375
 376 static const char *perf_config_dirname(const char *name, const char *value)
 377 {
 378         if (!name)
 379                 return NULL;
 380         return value;
 381 }
 382
 383 static int perf_buildid_config(const char *var, const char *value)
 384 {
 385         /* same dir for all commands */
 386         if (!strcmp(var, "buildid.dir")) {
 387                 const char *dir = perf_config_dirname(var, value);
 388
 389                 if (!dir) {
 390                         pr_err("Invalid buildid directory!\n");
 391                         return -1;
 392                 }
 393                 strncpy(buildid_dir, dir, MAXPATHLEN-1);
 394                 buildid_dir[MAXPATHLEN-1] = '\0';
 395         }
 396
 397         return 0;
 398 }
 399
 400 static int perf_default_core_config(const char *var __maybe_unused,
 401                                     const char *value __maybe_unused)
 402 {
 403         /* Add other config variables here. */
 404         return 0;
 405 }
 406
 407 static int perf_ui_config(const char *var, const char *value)
 408 {
 409         /* Add other config variables here. */
 410         if (!strcmp(var, "ui.show-headers"))
 411                 symbol_conf.show_hist_headers = perf_config_bool(var, value);
 412
 413         return 0;
 414 }
 415
 416 int perf_default_config(const char *var, const char *value,
 417                         void *dummy __maybe_unused)
 418 {
 419         if (!prefixcmp(var, "core."))
 420                 return perf_default_core_config(var, value);
 421
 422         if (!prefixcmp(var, "hist."))
 423                 return perf_hist_config(var, value);
 424
 425         if (!prefixcmp(var, "ui."))
 426                 return perf_ui_config(var, value);
 427
 428         if (!prefixcmp(var, "call-graph."))
 429                 return perf_callchain_config(var, value);
 430
 431         if (!prefixcmp(var, "llvm."))
 432                 return perf_llvm_config(var, value);
 433
 434         if (!prefixcmp(var, "buildid."))
 435                 return perf_buildid_config(var, value);
 436
 437         /* Add other config variables here. */
 438         return 0;
 439 }
 440
 441 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
 442 {
 443         int ret;
 444         FILE *f = fopen(filename, "r");
 445
 446         ret = -1;
 447         if (f) {
 448                 config_file = f;
 449                 config_file_name = filename;
 450                 config_linenr = 1;
 451                 config_file_eof = 0;
 452                 ret = perf_parse_file(fn, data);
 453                 fclose(f);
 454                 config_file_name = NULL;
 455         }
 456         return ret;
 457 }
 458
 459 const char *perf_etc_perfconfig(void)
 460 {
 461         static const char *system_wide;
 462         if (!system_wide)
 463                 system_wide = system_path(ETC_PERFCONFIG);
 464         return system_wide;
 465 }
 466
 467 static int perf_env_bool(const char *k, int def)
 468 {
 469         const char *v = getenv(k);
 470         return v ? perf_config_bool(k, v) : def;
 471 }
 472
 473 static int perf_config_system(void)
 474 {
 475         return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
 476 }
 477
 478 static int perf_config_global(void)
 479 {
 480         return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 481 }
 482
 483 static struct perf_config_section *find_section(struct list_head *sections,
 484                                                 const char *section_name)
 485 {
 486         struct perf_config_section *section;
 487
 488         list_for_each_entry(section, sections, node)
 489                 if (!strcmp(section->name, section_name))
 490                         return section;
 491
 492         return NULL;
 493 }
 494
 495 static struct perf_config_item *find_config_item(const char *name,
 496                                                  struct perf_config_section *section)
 497 {
 498         struct perf_config_item *item;
 499
 500         list_for_each_entry(item, &section->items, node)
 501                 if (!strcmp(item->name, name))
 502                         return item;
 503
 504         return NULL;
 505 }
 506
 507 static struct perf_config_section *add_section(struct list_head *sections,
 508                                                const char *section_name)
 509 {
 510         struct perf_config_section *section = zalloc(sizeof(*section));
 511
 512         if (!section)
 513                 return NULL;
 514
 515         INIT_LIST_HEAD(&section->items);
 516         section->name = strdup(section_name);
 517         if (!section->name) {
 518                 pr_debug("%s: strdup failed\n", __func__);
 519                 free(section);
 520                 return NULL;
 521         }
 522
 523         list_add_tail(&section->node, sections);
 524         return section;
 525 }
 526
 527 static struct perf_config_item *add_config_item(struct perf_config_section *section,
 528                                                 const char *name)
 529 {
 530         struct perf_config_item *item = zalloc(sizeof(*item));
 531
 532         if (!item)
 533                 return NULL;
 534
 535         item->name = strdup(name);
 536         if (!item->name) {
 537                 pr_debug("%s: strdup failed\n", __func__);
 538                 free(item);
 539                 return NULL;
 540         }
 541
 542         list_add_tail(&item->node, &section->items);
 543         return item;
 544 }
 545
 546 static int set_value(struct perf_config_item *item, const char *value)
 547 {
 548         char *val = strdup(value);
 549
 550         if (!val)
 551                 return -1;
 552
 553         zfree(&item->value);
 554         item->value = val;
 555         return 0;
 556 }
 557
 558 static int collect_config(const char *var, const char *value,
 559                           void *perf_config_set)
 560 {
 561         int ret = -1;
 562         char *ptr, *key;
 563         char *section_name, *name;
 564         struct perf_config_section *section = NULL;
 565         struct perf_config_item *item = NULL;
 566         struct perf_config_set *set = perf_config_set;
 567         struct list_head *sections;
 568
 569         if (set == NULL)
 570                 return -1;
 571
 572         sections = &set->sections;
 573         key = ptr = strdup(var);
 574         if (!key) {
 575                 pr_debug("%s: strdup failed\n", __func__);
 576                 return -1;
 577         }
 578
 579         section_name = strsep(&ptr, ".");
 580         name = ptr;
 581         if (name == NULL || value == NULL)
 582                 goto out_free;
 583
 584         section = find_section(sections, section_name);
 585         if (!section) {
 586                 section = add_section(sections, section_name);
 587                 if (!section)
 588                         goto out_free;
 589         }
 590
 591         item = find_config_item(name, section);
 592         if (!item) {
 593                 item = add_config_item(section, name);
 594                 if (!item)
 595                         goto out_free;
 596         }
 597
 598         /* perf_config_set can contain both user and system config items.
 599          * So we should know where each value is from.
 600          * The classification would be needed when a particular config file
 601          * is overwrited by setting feature i.e. set_config().
 602          */
 603         if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
 604                 section->from_system_config = true;
 605                 item->from_system_config = true;
 606         } else {
 607                 section->from_system_config = false;
 608                 item->from_system_config = false;
 609         }
 610
 611         ret = set_value(item, value);
 612         return ret;
 613
 614 out_free:
 615         free(key);
 616         return -1;
 617 }
 618
 619 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
 620                              const char *var, const char *value)
 621 {
 622         config_file_name = file_name;
 623         return collect_config(var, value, set);
 624 }
 625
 626 static int perf_config_set__init(struct perf_config_set *set)
 627 {
 628         int ret = -1;
 629         const char *home = NULL;
 630
 631         /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
 632         if (config_exclusive_filename)
 633                 return perf_config_from_file(collect_config, config_exclusive_filename, set);
 634         if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
 635                 if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
 636                         goto out;
 637         }
 638
 639         home = getenv("HOME");
 640         if (perf_config_global() && home) {
 641                 char *user_config = strdup(mkpath("%s/.perfconfig", home));
 642                 struct stat st;
 643
 644                 if (user_config == NULL) {
 645                         warning("Not enough memory to process %s/.perfconfig, "
 646                                 "ignoring it.", home);
 647                         goto out;
 648                 }
 649
 650                 if (stat(user_config, &st) < 0) {
 651                         if (errno == ENOENT)
 652                                 ret = 0;
 653                         goto out_free;
 654                 }
 655
 656                 ret = 0;
 657
 658                 if (st.st_uid && (st.st_uid != geteuid())) {
 659                         warning("File %s not owned by current user or root, "
 660                                 "ignoring it.", user_config);
 661                         goto out_free;
 662                 }
 663
 664                 if (st.st_size)
 665                         ret = perf_config_from_file(collect_config, user_config, set);
 666 out_free:
 667                 free(user_config);
 668         }
 669 out:
 670         return ret;
 671 }
 672
 673 struct perf_config_set *perf_config_set__new(void)
 674 {
 675         struct perf_config_set *set = zalloc(sizeof(*set));
 676
 677         if (set) {
 678                 INIT_LIST_HEAD(&set->sections);
 679                 if (perf_config_set__init(set) < 0) {
 680                         perf_config_set__delete(set);
 681                         set = NULL;
 682                 }
 683         }
 684
 685         return set;
 686 }
 687
 688 int perf_config(config_fn_t fn, void *data)
 689 {
 690         int ret = 0;
 691         char key[BUFSIZ];
 692         struct perf_config_section *section;
 693         struct perf_config_item *item;
 694
 695         if (config_set == NULL)
 696                 return -1;
 697
 698         perf_config_set__for_each_entry(config_set, section, item) {
 699                 char *value = item->value;
 700
 701                 if (value) {
 702                         scnprintf(key, sizeof(key), "%s.%s",
 703                                   section->name, item->name);
 704                         ret = fn(key, value, data);
 705                         if (ret < 0) {
 706                                 pr_err("Error: wrong config key-value pair %s=%s\n",
 707                                        key, value);
 708                                 break;
 709                         }
 710                 }
 711         }
 712
 713         return ret;
 714 }
 715
 716 void perf_config__init(void)
 717 {
 718         if (config_set == NULL)
 719                 config_set = perf_config_set__new();
 720 }
 721
 722 void perf_config__exit(void)
 723 {
 724         perf_config_set__delete(config_set);
 725         config_set = NULL;
 726 }
 727
 728 void perf_config__refresh(void)
 729 {
 730         perf_config__exit();
 731         perf_config__init();
 732 }
 733
 734 static void perf_config_item__delete(struct perf_config_item *item)
 735 {
 736         zfree(&item->name);
 737         zfree(&item->value);
 738         free(item);
 739 }
 740
 741 static void perf_config_section__purge(struct perf_config_section *section)
 742 {
 743         struct perf_config_item *item, *tmp;
 744
 745         list_for_each_entry_safe(item, tmp, &section->items, node) {
 746                 list_del_init(&item->node);
 747                 perf_config_item__delete(item);
 748         }
 749 }
 750
 751 static void perf_config_section__delete(struct perf_config_section *section)
 752 {
 753         perf_config_section__purge(section);
 754         zfree(&section->name);
 755         free(section);
 756 }
 757
 758 static void perf_config_set__purge(struct perf_config_set *set)
 759 {
 760         struct perf_config_section *section, *tmp;
 761
 762         list_for_each_entry_safe(section, tmp, &set->sections, node) {
 763                 list_del_init(&section->node);
 764                 perf_config_section__delete(section);
 765         }
 766 }
 767
 768 void perf_config_set__delete(struct perf_config_set *set)
 769 {
 770         if (set == NULL)
 771                 return;
 772
 773         perf_config_set__purge(set);
 774         free(set);
 775 }
 776
 777 /*
 778  * Call this to report error for your variable that should not
 779  * get a boolean value (i.e. "[my] var" means "true").
 780  */
 781 int config_error_nonbool(const char *var)
 782 {
 783         return error("Missing value for '%s'", var);
 784 }
 785
 786 void set_buildid_dir(const char *dir)
 787 {
 788         if (dir)
 789                 scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
 790
 791         /* default to $HOME/.debug */
 792         if (buildid_dir[0] == '\0') {
 793                 char *home = getenv("HOME");
 794
 795                 if (home) {
 796                         snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
 797                                  home, DEBUG_CACHE_DIR);
 798                 } else {
 799                         strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
 800                 }
 801                 buildid_dir[MAXPATHLEN-1] = '\0';
 802         }
 803         /* for communicating with external commands */
 804         setenv("PERF_BUILDID_DIR", buildid_dir, 1);
 805 }