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
get_next_char(void)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
parse_value(void)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
iskeychar(int c)123 static inline int iskeychar(int c)
124 {
125 return isalnum(c) || c == '-' || c == '_';
126 }
127
get_value(config_fn_t fn,void * data,char * name,unsigned int len)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
get_extended_base_var(char * name,int baselen,int c)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
get_base_var(char * name)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
perf_parse_file(config_fn_t fn,void * data)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
parse_unit_factor(const char * end,unsigned long * val)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
perf_parse_llong(const char * value,long long * ret)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
perf_parse_long(const char * value,long * ret)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
die_bad_config(const char * name)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
perf_config_u64(const char * name,const char * value)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
perf_config_int(const char * name,const char * value)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
perf_config_bool_or_int(const char * name,const char * value,int * is_bool)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
perf_config_bool(const char * name,const char * value)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
perf_config_dirname(const char * name,const char * value)373 const char *perf_config_dirname(const char *name, const char *value)
374 {
375 if (!name)
376 return NULL;
377 return value;
378 }
379
perf_default_core_config(const char * var __maybe_unused,const char * value __maybe_unused)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
perf_ui_config(const char * var,const char * value)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
perf_default_config(const char * var,const char * value,void * dummy __maybe_unused)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
perf_config_from_file(config_fn_t fn,const char * filename,void * data)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
perf_etc_perfconfig(void)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
perf_env_bool(const char * k,int def)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
perf_config_system(void)451 static int perf_config_system(void)
452 {
453 return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
454 }
455
perf_config_global(void)456 static int perf_config_global(void)
457 {
458 return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
459 }
460
perf_config(config_fn_t fn,void * data)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 */
config_error_nonbool(const char * var)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
buildid_dir_command_config(const char * var,const char * value,void * data)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
check_buildid_dir_config(void)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
set_buildid_dir(const char * dir)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 }
569