root/tools/perf/util/config.c

DEFINITIONS

1. get_next_char
2. parse_value
3. iskeychar
4. get_value
5. get_extended_base_var
6. get_base_var
7. perf_parse_file
8. parse_unit_factor
9. perf_parse_llong
10. perf_parse_long
11. bad_config
12. perf_config_u64
13. perf_config_int
14. perf_config_bool_or_int
15. perf_config_bool
16. perf_config_dirname
17. perf_buildid_config
18. perf_default_core_config
19. perf_ui_config
20. perf_default_config
21. perf_config_from_file
22. perf_etc_perfconfig
23. perf_env_bool
24. perf_config_system
25. perf_config_global
26. find_section
27. find_config_item
28. add_section
29. add_config_item
30. set_value
31. collect_config
32. perf_config_set__collect
33. perf_config_set__init
34. perf_config_set__new
35. perf_config__init
36. perf_config
37. perf_config__exit
38. perf_config__refresh
39. perf_config_item__delete
40. perf_config_section__purge
41. perf_config_section__delete
42. perf_config_set__purge
43. perf_config_set__delete
44. config_error_nonbool
45. set_buildid_dir

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * config.c
   4  *
   5  * Helper functions for parsing config items.
   6  * Originally copied from GIT source.
   7  *
   8  * Copyright (C) Linus Torvalds, 2005
   9  * Copyright (C) Johannes Schindelin, 2005
  10  *
  11  */
  12 #include <errno.h>
  13 #include <sys/param.h>
  14 #include "cache.h"
  15 #include "callchain.h"
  16 #include <subcmd/exec-cmd.h>
  17 #include "util/event.h"  /* proc_map_timeout */
  18 #include "util/hist.h"  /* perf_hist_config */
  19 #include "util/llvm-utils.h"   /* perf_llvm_config */
  20 #include "build-id.h"
  21 #include "debug.h"
  22 #include "config.h"
  23 #include "debug.h"
  24 #include <sys/types.h>
  25 #include <sys/stat.h>
  26 #include <stdlib.h>
  27 #include <unistd.h>
  28 #include <linux/string.h>
  29 #include <linux/zalloc.h>
  30 #include <linux/ctype.h>
  31 
  32 #define MAXNAME (256)
  33 
  34 #define DEBUG_CACHE_DIR ".debug"
  35 
  36 
  37 char buildid_dir[MAXPATHLEN]; /* root dir for buildid, binary cache */
  38 
  39 static FILE *config_file;
  40 static const char *config_file_name;
  41 static int config_linenr;
  42 static int config_file_eof;
  43 static struct perf_config_set *config_set;
  44 
  45 const char *config_exclusive_filename;
  46 
  47 static int get_next_char(void)
  48 {
  49         int c;
  50         FILE *f;
  51 
  52         c = '\n';
  53         if ((f = config_file) != NULL) {
  54                 c = fgetc(f);
  55                 if (c == '\r') {
  56                         /* DOS like systems */
  57                         c = fgetc(f);
  58                         if (c != '\n') {
  59                                 ungetc(c, f);
  60                                 c = '\r';
  61                         }
  62                 }
  63                 if (c == '\n')
  64                         config_linenr++;
  65                 if (c == EOF) {
  66                         config_file_eof = 1;
  67                         c = '\n';
  68                 }
  69         }
  70         return c;
  71 }
  72 
  73 static char *parse_value(void)
  74 {
  75         static char value[1024];
  76         int quote = 0, comment = 0, space = 0;
  77         size_t len = 0;
  78 
  79         for (;;) {
  80                 int c = get_next_char();
  81 
  82                 if (len >= sizeof(value) - 1)
  83                         return NULL;
  84                 if (c == '\n') {
  85                         if (quote)
  86                                 return NULL;
  87                         value[len] = 0;
  88                         return value;
  89                 }
  90                 if (comment)
  91                         continue;
  92                 if (isspace(c) && !quote) {
  93                         space = 1;
  94                         continue;
  95                 }
  96                 if (!quote) {
  97                         if (c == ';' || c == '#') {
  98                                 comment = 1;
  99                                 continue;
 100                         }
 101                 }
 102                 if (space) {
 103                         if (len)
 104                                 value[len++] = ' ';
 105                         space = 0;
 106                 }
 107                 if (c == '\\') {
 108                         c = get_next_char();
 109                         switch (c) {
 110                         case '\n':
 111                                 continue;
 112                         case 't':
 113                                 c = '\t';
 114                                 break;
 115                         case 'b':
 116                                 c = '\b';
 117                                 break;
 118                         case 'n':
 119                                 c = '\n';
 120                                 break;
 121                         /* Some characters escape as themselves */
 122                         case '\\': case '"':
 123                                 break;
 124                         /* Reject unknown escape sequences */
 125                         default:
 126                                 return NULL;
 127                         }
 128                         value[len++] = c;
 129                         continue;
 130                 }
 131                 if (c == '"') {
 132                         quote = 1-quote;
 133                         continue;
 134                 }
 135                 value[len++] = c;
 136         }
 137 }
 138 
 139 static inline int iskeychar(int c)
 140 {
 141         return isalnum(c) || c == '-' || c == '_';
 142 }
 143 
 144 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
 145 {
 146         int c;
 147         char *value;
 148 
 149         /* Get the full name */
 150         for (;;) {
 151                 c = get_next_char();
 152                 if (config_file_eof)
 153                         break;
 154                 if (!iskeychar(c))
 155                         break;
 156                 name[len++] = c;
 157                 if (len >= MAXNAME)
 158                         return -1;
 159         }
 160         name[len] = 0;
 161         while (c == ' ' || c == '\t')
 162                 c = get_next_char();
 163 
 164         value = NULL;
 165         if (c != '\n') {
 166                 if (c != '=')
 167                         return -1;
 168                 value = parse_value();
 169                 if (!value)
 170                         return -1;
 171         }
 172         return fn(name, value, data);
 173 }
 174 
 175 static int get_extended_base_var(char *name, int baselen, int c)
 176 {
 177         do {
 178                 if (c == '\n')
 179                         return -1;
 180                 c = get_next_char();
 181         } while (isspace(c));
 182 
 183         /* We require the format to be '[base "extension"]' */
 184         if (c != '"')
 185                 return -1;
 186         name[baselen++] = '.';
 187 
 188         for (;;) {
 189                 int ch = get_next_char();
 190 
 191                 if (ch == '\n')
 192                         return -1;
 193                 if (ch == '"')
 194                         break;
 195                 if (ch == '\\') {
 196                         ch = get_next_char();
 197                         if (ch == '\n')
 198                                 return -1;
 199                 }
 200                 name[baselen++] = ch;
 201                 if (baselen > MAXNAME / 2)
 202                         return -1;
 203         }
 204 
 205         /* Final ']' */
 206         if (get_next_char() != ']')
 207                 return -1;
 208         return baselen;
 209 }
 210 
 211 static int get_base_var(char *name)
 212 {
 213         int baselen = 0;
 214 
 215         for (;;) {
 216                 int c = get_next_char();
 217                 if (config_file_eof)
 218                         return -1;
 219                 if (c == ']')
 220                         return baselen;
 221                 if (isspace(c))
 222                         return get_extended_base_var(name, baselen, c);
 223                 if (!iskeychar(c) && c != '.')
 224                         return -1;
 225                 if (baselen > MAXNAME / 2)
 226                         return -1;
 227                 name[baselen++] = tolower(c);
 228         }
 229 }
 230 
 231 static int perf_parse_file(config_fn_t fn, void *data)
 232 {
 233         int comment = 0;
 234         int baselen = 0;
 235         static char var[MAXNAME];
 236 
 237         /* U+FEFF Byte Order Mark in UTF8 */
 238         static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
 239         const unsigned char *bomptr = utf8_bom;
 240 
 241         for (;;) {
 242                 int line, c = get_next_char();
 243 
 244                 if (bomptr && *bomptr) {
 245                         /* We are at the file beginning; skip UTF8-encoded BOM
 246                          * if present. Sane editors won't put this in on their
 247                          * own, but e.g. Windows Notepad will do it happily. */
 248                         if ((unsigned char) c == *bomptr) {
 249                                 bomptr++;
 250                                 continue;
 251                         } else {
 252                                 /* Do not tolerate partial BOM. */
 253                                 if (bomptr != utf8_bom)
 254                                         break;
 255                                 /* No BOM at file beginning. Cool. */
 256                                 bomptr = NULL;
 257                         }
 258                 }
 259                 if (c == '\n') {
 260                         if (config_file_eof)
 261                                 return 0;
 262                         comment = 0;
 263                         continue;
 264                 }
 265                 if (comment || isspace(c))
 266                         continue;
 267                 if (c == '#' || c == ';') {
 268                         comment = 1;
 269                         continue;
 270                 }
 271                 if (c == '[') {
 272                         baselen = get_base_var(var);
 273                         if (baselen <= 0)
 274                                 break;
 275                         var[baselen++] = '.';
 276                         var[baselen] = 0;
 277                         continue;
 278                 }
 279                 if (!isalpha(c))
 280                         break;
 281                 var[baselen] = tolower(c);
 282 
 283                 /*
 284                  * The get_value function might or might not reach the '\n',
 285                  * so saving the current line number for error reporting.
 286                  */
 287                 line = config_linenr;
 288                 if (get_value(fn, data, var, baselen+1) < 0) {
 289                         config_linenr = line;
 290                         break;
 291                 }
 292         }
 293         pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
 294         return -1;
 295 }
 296 
 297 static int parse_unit_factor(const char *end, unsigned long *val)
 298 {
 299         if (!*end)
 300                 return 1;
 301         else if (!strcasecmp(end, "k")) {
 302                 *val *= 1024;
 303                 return 1;
 304         }
 305         else if (!strcasecmp(end, "m")) {
 306                 *val *= 1024 * 1024;
 307                 return 1;
 308         }
 309         else if (!strcasecmp(end, "g")) {
 310                 *val *= 1024 * 1024 * 1024;
 311                 return 1;
 312         }
 313         return 0;
 314 }
 315 
 316 static int perf_parse_llong(const char *value, long long *ret)
 317 {
 318         if (value && *value) {
 319                 char *end;
 320                 long long val = strtoll(value, &end, 0);
 321                 unsigned long factor = 1;
 322 
 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 int perf_parse_long(const char *value, long *ret)
 332 {
 333         if (value && *value) {
 334                 char *end;
 335                 long val = strtol(value, &end, 0);
 336                 unsigned long factor = 1;
 337                 if (!parse_unit_factor(end, &factor))
 338                         return 0;
 339                 *ret = val * factor;
 340                 return 1;
 341         }
 342         return 0;
 343 }
 344 
 345 static void bad_config(const char *name)
 346 {
 347         if (config_file_name)
 348                 pr_warning("bad config value for '%s' in %s, ignoring...\n", name, config_file_name);
 349         else
 350                 pr_warning("bad config value for '%s', ignoring...\n", name);
 351 }
 352 
 353 int perf_config_u64(u64 *dest, const char *name, const char *value)
 354 {
 355         long long ret = 0;
 356 
 357         if (!perf_parse_llong(value, &ret)) {
 358                 bad_config(name);
 359                 return -1;
 360         }
 361 
 362         *dest = ret;
 363         return 0;
 364 }
 365 
 366 int perf_config_int(int *dest, const char *name, const char *value)
 367 {
 368         long ret = 0;
 369         if (!perf_parse_long(value, &ret)) {
 370                 bad_config(name);
 371                 return -1;
 372         }
 373         *dest = ret;
 374         return 0;
 375 }
 376 
 377 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
 378 {
 379         int ret;
 380 
 381         *is_bool = 1;
 382         if (!value)
 383                 return 1;
 384         if (!*value)
 385                 return 0;
 386         if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
 387                 return 1;
 388         if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
 389                 return 0;
 390         *is_bool = 0;
 391         return perf_config_int(&ret, name, value) < 0 ? -1 : ret;
 392 }
 393 
 394 int perf_config_bool(const char *name, const char *value)
 395 {
 396         int discard;
 397         return !!perf_config_bool_or_int(name, value, &discard);
 398 }
 399 
 400 static const char *perf_config_dirname(const char *name, const char *value)
 401 {
 402         if (!name)
 403                 return NULL;
 404         return value;
 405 }
 406 
 407 static int perf_buildid_config(const char *var, const char *value)
 408 {
 409         /* same dir for all commands */
 410         if (!strcmp(var, "buildid.dir")) {
 411                 const char *dir = perf_config_dirname(var, value);
 412 
 413                 if (!dir) {
 414                         pr_err("Invalid buildid directory!\n");
 415                         return -1;
 416                 }
 417                 strncpy(buildid_dir, dir, MAXPATHLEN-1);
 418                 buildid_dir[MAXPATHLEN-1] = '\0';
 419         }
 420 
 421         return 0;
 422 }
 423 
 424 static int perf_default_core_config(const char *var __maybe_unused,
 425                                     const char *value __maybe_unused)
 426 {
 427         if (!strcmp(var, "core.proc-map-timeout"))
 428                 proc_map_timeout = strtoul(value, NULL, 10);
 429 
 430         /* Add other config variables here. */
 431         return 0;
 432 }
 433 
 434 static int perf_ui_config(const char *var, const char *value)
 435 {
 436         /* Add other config variables here. */
 437         if (!strcmp(var, "ui.show-headers"))
 438                 symbol_conf.show_hist_headers = perf_config_bool(var, value);
 439 
 440         return 0;
 441 }
 442 
 443 int perf_default_config(const char *var, const char *value,
 444                         void *dummy __maybe_unused)
 445 {
 446         if (strstarts(var, "core."))
 447                 return perf_default_core_config(var, value);
 448 
 449         if (strstarts(var, "hist."))
 450                 return perf_hist_config(var, value);
 451 
 452         if (strstarts(var, "ui."))
 453                 return perf_ui_config(var, value);
 454 
 455         if (strstarts(var, "call-graph."))
 456                 return perf_callchain_config(var, value);
 457 
 458         if (strstarts(var, "llvm."))
 459                 return perf_llvm_config(var, value);
 460 
 461         if (strstarts(var, "buildid."))
 462                 return perf_buildid_config(var, value);
 463 
 464         /* Add other config variables here. */
 465         return 0;
 466 }
 467 
 468 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
 469 {
 470         int ret;
 471         FILE *f = fopen(filename, "r");
 472 
 473         ret = -1;
 474         if (f) {
 475                 config_file = f;
 476                 config_file_name = filename;
 477                 config_linenr = 1;
 478                 config_file_eof = 0;
 479                 ret = perf_parse_file(fn, data);
 480                 fclose(f);
 481                 config_file_name = NULL;
 482         }
 483         return ret;
 484 }
 485 
 486 const char *perf_etc_perfconfig(void)
 487 {
 488         static const char *system_wide;
 489         if (!system_wide)
 490                 system_wide = system_path(ETC_PERFCONFIG);
 491         return system_wide;
 492 }
 493 
 494 static int perf_env_bool(const char *k, int def)
 495 {
 496         const char *v = getenv(k);
 497         return v ? perf_config_bool(k, v) : def;
 498 }
 499 
 500 static int perf_config_system(void)
 501 {
 502         return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
 503 }
 504 
 505 static int perf_config_global(void)
 506 {
 507         return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
 508 }
 509 
 510 static struct perf_config_section *find_section(struct list_head *sections,
 511                                                 const char *section_name)
 512 {
 513         struct perf_config_section *section;
 514 
 515         list_for_each_entry(section, sections, node)
 516                 if (!strcmp(section->name, section_name))
 517                         return section;
 518 
 519         return NULL;
 520 }
 521 
 522 static struct perf_config_item *find_config_item(const char *name,
 523                                                  struct perf_config_section *section)
 524 {
 525         struct perf_config_item *item;
 526 
 527         list_for_each_entry(item, &section->items, node)
 528                 if (!strcmp(item->name, name))
 529                         return item;
 530 
 531         return NULL;
 532 }
 533 
 534 static struct perf_config_section *add_section(struct list_head *sections,
 535                                                const char *section_name)
 536 {
 537         struct perf_config_section *section = zalloc(sizeof(*section));
 538 
 539         if (!section)
 540                 return NULL;
 541 
 542         INIT_LIST_HEAD(&section->items);
 543         section->name = strdup(section_name);
 544         if (!section->name) {
 545                 pr_debug("%s: strdup failed\n", __func__);
 546                 free(section);
 547                 return NULL;
 548         }
 549 
 550         list_add_tail(&section->node, sections);
 551         return section;
 552 }
 553 
 554 static struct perf_config_item *add_config_item(struct perf_config_section *section,
 555                                                 const char *name)
 556 {
 557         struct perf_config_item *item = zalloc(sizeof(*item));
 558 
 559         if (!item)
 560                 return NULL;
 561 
 562         item->name = strdup(name);
 563         if (!item->name) {
 564                 pr_debug("%s: strdup failed\n", __func__);
 565                 free(item);
 566                 return NULL;
 567         }
 568 
 569         list_add_tail(&item->node, &section->items);
 570         return item;
 571 }
 572 
 573 static int set_value(struct perf_config_item *item, const char *value)
 574 {
 575         char *val = strdup(value);
 576 
 577         if (!val)
 578                 return -1;
 579 
 580         zfree(&item->value);
 581         item->value = val;
 582         return 0;
 583 }
 584 
 585 static int collect_config(const char *var, const char *value,
 586                           void *perf_config_set)
 587 {
 588         int ret = -1;
 589         char *ptr, *key;
 590         char *section_name, *name;
 591         struct perf_config_section *section = NULL;
 592         struct perf_config_item *item = NULL;
 593         struct perf_config_set *set = perf_config_set;
 594         struct list_head *sections;
 595 
 596         if (set == NULL)
 597                 return -1;
 598 
 599         sections = &set->sections;
 600         key = ptr = strdup(var);
 601         if (!key) {
 602                 pr_debug("%s: strdup failed\n", __func__);
 603                 return -1;
 604         }
 605 
 606         section_name = strsep(&ptr, ".");
 607         name = ptr;
 608         if (name == NULL || value == NULL)
 609                 goto out_free;
 610 
 611         section = find_section(sections, section_name);
 612         if (!section) {
 613                 section = add_section(sections, section_name);
 614                 if (!section)
 615                         goto out_free;
 616         }
 617 
 618         item = find_config_item(name, section);
 619         if (!item) {
 620                 item = add_config_item(section, name);
 621                 if (!item)
 622                         goto out_free;
 623         }
 624 
 625         /* perf_config_set can contain both user and system config items.
 626          * So we should know where each value is from.
 627          * The classification would be needed when a particular config file
 628          * is overwrited by setting feature i.e. set_config().
 629          */
 630         if (strcmp(config_file_name, perf_etc_perfconfig()) == 0) {
 631                 section->from_system_config = true;
 632                 item->from_system_config = true;
 633         } else {
 634                 section->from_system_config = false;
 635                 item->from_system_config = false;
 636         }
 637 
 638         ret = set_value(item, value);
 639 
 640 out_free:
 641         free(key);
 642         return ret;
 643 }
 644 
 645 int perf_config_set__collect(struct perf_config_set *set, const char *file_name,
 646                              const char *var, const char *value)
 647 {
 648         config_file_name = file_name;
 649         return collect_config(var, value, set);
 650 }
 651 
 652 static int perf_config_set__init(struct perf_config_set *set)
 653 {
 654         int ret = -1;
 655         const char *home = NULL;
 656         char *user_config;
 657         struct stat st;
 658 
 659         /* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
 660         if (config_exclusive_filename)
 661                 return perf_config_from_file(collect_config, config_exclusive_filename, set);
 662         if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
 663                 if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
 664                         goto out;
 665         }
 666 
 667         home = getenv("HOME");
 668 
 669         /*
 670          * Skip reading user config if:
 671          *   - there is no place to read it from (HOME)
 672          *   - we are asked not to (PERF_CONFIG_NOGLOBAL=1)
 673          */
 674         if (!home || !*home || !perf_config_global())
 675                 return 0;
 676 
 677         user_config = strdup(mkpath("%s/.perfconfig", home));
 678         if (user_config == NULL) {
 679                 pr_warning("Not enough memory to process %s/.perfconfig, ignoring it.", home);
 680                 goto out;
 681         }
 682 
 683         if (stat(user_config, &st) < 0) {
 684                 if (errno == ENOENT)
 685                         ret = 0;
 686                 goto out_free;
 687         }
 688 
 689         ret = 0;
 690 
 691         if (st.st_uid && (st.st_uid != geteuid())) {
 692                 pr_warning("File %s not owned by current user or root, ignoring it.", user_config);
 693                 goto out_free;
 694         }
 695 
 696         if (st.st_size)
 697                 ret = perf_config_from_file(collect_config, user_config, set);
 698 
 699 out_free:
 700         free(user_config);
 701 out:
 702         return ret;
 703 }
 704 
 705 struct perf_config_set *perf_config_set__new(void)
 706 {
 707         struct perf_config_set *set = zalloc(sizeof(*set));
 708 
 709         if (set) {
 710                 INIT_LIST_HEAD(&set->sections);
 711                 perf_config_set__init(set);
 712         }
 713 
 714         return set;
 715 }
 716 
 717 static int perf_config__init(void)
 718 {
 719         if (config_set == NULL)
 720                 config_set = perf_config_set__new();
 721 
 722         return config_set == NULL;
 723 }
 724 
 725 int perf_config(config_fn_t fn, void *data)
 726 {
 727         int ret = 0;
 728         char key[BUFSIZ];
 729         struct perf_config_section *section;
 730         struct perf_config_item *item;
 731 
 732         if (config_set == NULL && perf_config__init())
 733                 return -1;
 734 
 735         perf_config_set__for_each_entry(config_set, section, item) {
 736                 char *value = item->value;
 737 
 738                 if (value) {
 739                         scnprintf(key, sizeof(key), "%s.%s",
 740                                   section->name, item->name);
 741                         ret = fn(key, value, data);
 742                         if (ret < 0) {
 743                                 pr_err("Error: wrong config key-value pair %s=%s\n",
 744                                        key, value);
 745                                 /*
 746                                  * Can't be just a 'break', as perf_config_set__for_each_entry()
 747                                  * expands to two nested for() loops.
 748                                  */
 749                                 goto out;
 750                         }
 751                 }
 752         }
 753 out:
 754         return ret;
 755 }
 756 
 757 void perf_config__exit(void)
 758 {
 759         perf_config_set__delete(config_set);
 760         config_set = NULL;
 761 }
 762 
 763 void perf_config__refresh(void)
 764 {
 765         perf_config__exit();
 766         perf_config__init();
 767 }
 768 
 769 static void perf_config_item__delete(struct perf_config_item *item)
 770 {
 771         zfree(&item->name);
 772         zfree(&item->value);
 773         free(item);
 774 }
 775 
 776 static void perf_config_section__purge(struct perf_config_section *section)
 777 {
 778         struct perf_config_item *item, *tmp;
 779 
 780         list_for_each_entry_safe(item, tmp, &section->items, node) {
 781                 list_del_init(&item->node);
 782                 perf_config_item__delete(item);
 783         }
 784 }
 785 
 786 static void perf_config_section__delete(struct perf_config_section *section)
 787 {
 788         perf_config_section__purge(section);
 789         zfree(&section->name);
 790         free(section);
 791 }
 792 
 793 static void perf_config_set__purge(struct perf_config_set *set)
 794 {
 795         struct perf_config_section *section, *tmp;
 796 
 797         list_for_each_entry_safe(section, tmp, &set->sections, node) {
 798                 list_del_init(&section->node);
 799                 perf_config_section__delete(section);
 800         }
 801 }
 802 
 803 void perf_config_set__delete(struct perf_config_set *set)
 804 {
 805         if (set == NULL)
 806                 return;
 807 
 808         perf_config_set__purge(set);
 809         free(set);
 810 }
 811 
 812 /*
 813  * Call this to report error for your variable that should not
 814  * get a boolean value (i.e. "[my] var" means "true").
 815  */
 816 int config_error_nonbool(const char *var)
 817 {
 818         pr_err("Missing value for '%s'", var);
 819         return -1;
 820 }
 821 
 822 void set_buildid_dir(const char *dir)
 823 {
 824         if (dir)
 825                 scnprintf(buildid_dir, MAXPATHLEN, "%s", dir);
 826 
 827         /* default to $HOME/.debug */
 828         if (buildid_dir[0] == '\0') {
 829                 char *home = getenv("HOME");
 830 
 831                 if (home) {
 832                         snprintf(buildid_dir, MAXPATHLEN, "%s/%s",
 833                                  home, DEBUG_CACHE_DIR);
 834                 } else {
 835                         strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
 836                 }
 837                 buildid_dir[MAXPATHLEN-1] = '\0';
 838         }
 839         /* for communicating with external commands */
 840         setenv("PERF_BUILDID_DIR", buildid_dir, 1);
 841 }