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