xref: /linux/tools/perf/util/config.c (revision 5dafea097ac65bd01cc86801c399ae41dce79756)
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 
30 const char *config_exclusive_filename;
31 
32 static int get_next_char(void)
33 {
34 	int c;
35 	FILE *f;
36 
37 	c = '\n';
38 	if ((f = config_file) != NULL) {
39 		c = fgetc(f);
40 		if (c == '\r') {
41 			/* DOS like systems */
42 			c = fgetc(f);
43 			if (c != '\n') {
44 				ungetc(c, f);
45 				c = '\r';
46 			}
47 		}
48 		if (c == '\n')
49 			config_linenr++;
50 		if (c == EOF) {
51 			config_file_eof = 1;
52 			c = '\n';
53 		}
54 	}
55 	return c;
56 }
57 
58 static char *parse_value(void)
59 {
60 	static char value[1024];
61 	int quote = 0, comment = 0, space = 0;
62 	size_t len = 0;
63 
64 	for (;;) {
65 		int c = get_next_char();
66 
67 		if (len >= sizeof(value) - 1)
68 			return NULL;
69 		if (c == '\n') {
70 			if (quote)
71 				return NULL;
72 			value[len] = 0;
73 			return value;
74 		}
75 		if (comment)
76 			continue;
77 		if (isspace(c) && !quote) {
78 			space = 1;
79 			continue;
80 		}
81 		if (!quote) {
82 			if (c == ';' || c == '#') {
83 				comment = 1;
84 				continue;
85 			}
86 		}
87 		if (space) {
88 			if (len)
89 				value[len++] = ' ';
90 			space = 0;
91 		}
92 		if (c == '\\') {
93 			c = get_next_char();
94 			switch (c) {
95 			case '\n':
96 				continue;
97 			case 't':
98 				c = '\t';
99 				break;
100 			case 'b':
101 				c = '\b';
102 				break;
103 			case 'n':
104 				c = '\n';
105 				break;
106 			/* Some characters escape as themselves */
107 			case '\\': case '"':
108 				break;
109 			/* Reject unknown escape sequences */
110 			default:
111 				return NULL;
112 			}
113 			value[len++] = c;
114 			continue;
115 		}
116 		if (c == '"') {
117 			quote = 1-quote;
118 			continue;
119 		}
120 		value[len++] = c;
121 	}
122 }
123 
124 static inline int iskeychar(int c)
125 {
126 	return isalnum(c) || c == '-' || c == '_';
127 }
128 
129 static int get_value(config_fn_t fn, void *data, char *name, unsigned int len)
130 {
131 	int c;
132 	char *value;
133 
134 	/* Get the full name */
135 	for (;;) {
136 		c = get_next_char();
137 		if (config_file_eof)
138 			break;
139 		if (!iskeychar(c))
140 			break;
141 		name[len++] = c;
142 		if (len >= MAXNAME)
143 			return -1;
144 	}
145 	name[len] = 0;
146 	while (c == ' ' || c == '\t')
147 		c = get_next_char();
148 
149 	value = NULL;
150 	if (c != '\n') {
151 		if (c != '=')
152 			return -1;
153 		value = parse_value();
154 		if (!value)
155 			return -1;
156 	}
157 	return fn(name, value, data);
158 }
159 
160 static int get_extended_base_var(char *name, int baselen, int c)
161 {
162 	do {
163 		if (c == '\n')
164 			return -1;
165 		c = get_next_char();
166 	} while (isspace(c));
167 
168 	/* We require the format to be '[base "extension"]' */
169 	if (c != '"')
170 		return -1;
171 	name[baselen++] = '.';
172 
173 	for (;;) {
174 		int ch = get_next_char();
175 
176 		if (ch == '\n')
177 			return -1;
178 		if (ch == '"')
179 			break;
180 		if (ch == '\\') {
181 			ch = get_next_char();
182 			if (ch == '\n')
183 				return -1;
184 		}
185 		name[baselen++] = ch;
186 		if (baselen > MAXNAME / 2)
187 			return -1;
188 	}
189 
190 	/* Final ']' */
191 	if (get_next_char() != ']')
192 		return -1;
193 	return baselen;
194 }
195 
196 static int get_base_var(char *name)
197 {
198 	int baselen = 0;
199 
200 	for (;;) {
201 		int c = get_next_char();
202 		if (config_file_eof)
203 			return -1;
204 		if (c == ']')
205 			return baselen;
206 		if (isspace(c))
207 			return get_extended_base_var(name, baselen, c);
208 		if (!iskeychar(c) && c != '.')
209 			return -1;
210 		if (baselen > MAXNAME / 2)
211 			return -1;
212 		name[baselen++] = tolower(c);
213 	}
214 }
215 
216 static int perf_parse_file(config_fn_t fn, void *data)
217 {
218 	int comment = 0;
219 	int baselen = 0;
220 	static char var[MAXNAME];
221 
222 	/* U+FEFF Byte Order Mark in UTF8 */
223 	static const unsigned char *utf8_bom = (unsigned char *) "\xef\xbb\xbf";
224 	const unsigned char *bomptr = utf8_bom;
225 
226 	for (;;) {
227 		int line, c = get_next_char();
228 
229 		if (bomptr && *bomptr) {
230 			/* We are at the file beginning; skip UTF8-encoded BOM
231 			 * if present. Sane editors won't put this in on their
232 			 * own, but e.g. Windows Notepad will do it happily. */
233 			if ((unsigned char) c == *bomptr) {
234 				bomptr++;
235 				continue;
236 			} else {
237 				/* Do not tolerate partial BOM. */
238 				if (bomptr != utf8_bom)
239 					break;
240 				/* No BOM at file beginning. Cool. */
241 				bomptr = NULL;
242 			}
243 		}
244 		if (c == '\n') {
245 			if (config_file_eof)
246 				return 0;
247 			comment = 0;
248 			continue;
249 		}
250 		if (comment || isspace(c))
251 			continue;
252 		if (c == '#' || c == ';') {
253 			comment = 1;
254 			continue;
255 		}
256 		if (c == '[') {
257 			baselen = get_base_var(var);
258 			if (baselen <= 0)
259 				break;
260 			var[baselen++] = '.';
261 			var[baselen] = 0;
262 			continue;
263 		}
264 		if (!isalpha(c))
265 			break;
266 		var[baselen] = tolower(c);
267 
268 		/*
269 		 * The get_value function might or might not reach the '\n',
270 		 * so saving the current line number for error reporting.
271 		 */
272 		line = config_linenr;
273 		if (get_value(fn, data, var, baselen+1) < 0) {
274 			config_linenr = line;
275 			break;
276 		}
277 	}
278 	pr_err("bad config file line %d in %s\n", config_linenr, config_file_name);
279 	return -1;
280 }
281 
282 static int parse_unit_factor(const char *end, unsigned long *val)
283 {
284 	if (!*end)
285 		return 1;
286 	else if (!strcasecmp(end, "k")) {
287 		*val *= 1024;
288 		return 1;
289 	}
290 	else if (!strcasecmp(end, "m")) {
291 		*val *= 1024 * 1024;
292 		return 1;
293 	}
294 	else if (!strcasecmp(end, "g")) {
295 		*val *= 1024 * 1024 * 1024;
296 		return 1;
297 	}
298 	return 0;
299 }
300 
301 static int perf_parse_llong(const char *value, long long *ret)
302 {
303 	if (value && *value) {
304 		char *end;
305 		long long val = strtoll(value, &end, 0);
306 		unsigned long factor = 1;
307 
308 		if (!parse_unit_factor(end, &factor))
309 			return 0;
310 		*ret = val * factor;
311 		return 1;
312 	}
313 	return 0;
314 }
315 
316 static int perf_parse_long(const char *value, long *ret)
317 {
318 	if (value && *value) {
319 		char *end;
320 		long val = strtol(value, &end, 0);
321 		unsigned long factor = 1;
322 		if (!parse_unit_factor(end, &factor))
323 			return 0;
324 		*ret = val * factor;
325 		return 1;
326 	}
327 	return 0;
328 }
329 
330 static void die_bad_config(const char *name)
331 {
332 	if (config_file_name)
333 		die("bad config value for '%s' in %s", name, config_file_name);
334 	die("bad config value for '%s'", name);
335 }
336 
337 u64 perf_config_u64(const char *name, const char *value)
338 {
339 	long long ret = 0;
340 
341 	if (!perf_parse_llong(value, &ret))
342 		die_bad_config(name);
343 	return (u64) ret;
344 }
345 
346 int perf_config_int(const char *name, const char *value)
347 {
348 	long ret = 0;
349 	if (!perf_parse_long(value, &ret))
350 		die_bad_config(name);
351 	return ret;
352 }
353 
354 static int perf_config_bool_or_int(const char *name, const char *value, int *is_bool)
355 {
356 	*is_bool = 1;
357 	if (!value)
358 		return 1;
359 	if (!*value)
360 		return 0;
361 	if (!strcasecmp(value, "true") || !strcasecmp(value, "yes") || !strcasecmp(value, "on"))
362 		return 1;
363 	if (!strcasecmp(value, "false") || !strcasecmp(value, "no") || !strcasecmp(value, "off"))
364 		return 0;
365 	*is_bool = 0;
366 	return perf_config_int(name, value);
367 }
368 
369 int perf_config_bool(const char *name, const char *value)
370 {
371 	int discard;
372 	return !!perf_config_bool_or_int(name, value, &discard);
373 }
374 
375 static const char *perf_config_dirname(const char *name, const char *value)
376 {
377 	if (!name)
378 		return NULL;
379 	return value;
380 }
381 
382 static int perf_buildid_config(const char *var, const char *value)
383 {
384 	/* same dir for all commands */
385 	if (!strcmp(var, "buildid.dir")) {
386 		const char *dir = perf_config_dirname(var, value);
387 
388 		if (!dir)
389 			return -1;
390 		strncpy(buildid_dir, dir, MAXPATHLEN-1);
391 		buildid_dir[MAXPATHLEN-1] = '\0';
392 	}
393 
394 	return 0;
395 }
396 
397 static int perf_default_core_config(const char *var __maybe_unused,
398 				    const char *value __maybe_unused)
399 {
400 	/* Add other config variables here. */
401 	return 0;
402 }
403 
404 static int perf_ui_config(const char *var, const char *value)
405 {
406 	/* Add other config variables here. */
407 	if (!strcmp(var, "ui.show-headers")) {
408 		symbol_conf.show_hist_headers = perf_config_bool(var, value);
409 		return 0;
410 	}
411 	return 0;
412 }
413 
414 int perf_default_config(const char *var, const char *value,
415 			void *dummy __maybe_unused)
416 {
417 	if (!prefixcmp(var, "core."))
418 		return perf_default_core_config(var, value);
419 
420 	if (!prefixcmp(var, "hist."))
421 		return perf_hist_config(var, value);
422 
423 	if (!prefixcmp(var, "ui."))
424 		return perf_ui_config(var, value);
425 
426 	if (!prefixcmp(var, "call-graph."))
427 		return perf_callchain_config(var, value);
428 
429 	if (!prefixcmp(var, "llvm."))
430 		return perf_llvm_config(var, value);
431 
432 	if (!prefixcmp(var, "buildid."))
433 		return perf_buildid_config(var, value);
434 
435 	/* Add other config variables here. */
436 	return 0;
437 }
438 
439 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
440 {
441 	int ret;
442 	FILE *f = fopen(filename, "r");
443 
444 	ret = -1;
445 	if (f) {
446 		config_file = f;
447 		config_file_name = filename;
448 		config_linenr = 1;
449 		config_file_eof = 0;
450 		ret = perf_parse_file(fn, data);
451 		fclose(f);
452 		config_file_name = NULL;
453 	}
454 	return ret;
455 }
456 
457 const char *perf_etc_perfconfig(void)
458 {
459 	static const char *system_wide;
460 	if (!system_wide)
461 		system_wide = system_path(ETC_PERFCONFIG);
462 	return system_wide;
463 }
464 
465 static int perf_env_bool(const char *k, int def)
466 {
467 	const char *v = getenv(k);
468 	return v ? perf_config_bool(k, v) : def;
469 }
470 
471 static int perf_config_system(void)
472 {
473 	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
474 }
475 
476 static int perf_config_global(void)
477 {
478 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
479 }
480 
481 int perf_config(config_fn_t fn, void *data)
482 {
483 	int ret = -1;
484 	const char *home = NULL;
485 
486 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
487 	if (config_exclusive_filename)
488 		return perf_config_from_file(fn, config_exclusive_filename, data);
489 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
490 		if (perf_config_from_file(fn, perf_etc_perfconfig(), data) < 0)
491 			goto out;
492 	}
493 
494 	home = getenv("HOME");
495 	if (perf_config_global() && home) {
496 		char *user_config = strdup(mkpath("%s/.perfconfig", home));
497 		struct stat st;
498 
499 		if (user_config == NULL) {
500 			warning("Not enough memory to process %s/.perfconfig, "
501 				"ignoring it.", home);
502 			goto out;
503 		}
504 
505 		if (stat(user_config, &st) < 0)
506 			goto out_free;
507 
508 		if (st.st_uid && (st.st_uid != geteuid())) {
509 			warning("File %s not owned by current user or root, "
510 				"ignoring it.", user_config);
511 			goto out_free;
512 		}
513 
514 		if (!st.st_size)
515 			goto out_free;
516 
517 		ret = perf_config_from_file(fn, user_config, data);
518 
519 out_free:
520 		free(user_config);
521 	}
522 out:
523 	return ret;
524 }
525 
526 static struct perf_config_section *find_section(struct list_head *sections,
527 						const char *section_name)
528 {
529 	struct perf_config_section *section;
530 
531 	list_for_each_entry(section, sections, node)
532 		if (!strcmp(section->name, section_name))
533 			return section;
534 
535 	return NULL;
536 }
537 
538 static struct perf_config_item *find_config_item(const char *name,
539 						 struct perf_config_section *section)
540 {
541 	struct perf_config_item *item;
542 
543 	list_for_each_entry(item, &section->items, node)
544 		if (!strcmp(item->name, name))
545 			return item;
546 
547 	return NULL;
548 }
549 
550 static struct perf_config_section *add_section(struct list_head *sections,
551 					       const char *section_name)
552 {
553 	struct perf_config_section *section = zalloc(sizeof(*section));
554 
555 	if (!section)
556 		return NULL;
557 
558 	INIT_LIST_HEAD(&section->items);
559 	section->name = strdup(section_name);
560 	if (!section->name) {
561 		pr_debug("%s: strdup failed\n", __func__);
562 		free(section);
563 		return NULL;
564 	}
565 
566 	list_add_tail(&section->node, sections);
567 	return section;
568 }
569 
570 static struct perf_config_item *add_config_item(struct perf_config_section *section,
571 						const char *name)
572 {
573 	struct perf_config_item *item = zalloc(sizeof(*item));
574 
575 	if (!item)
576 		return NULL;
577 
578 	item->name = strdup(name);
579 	if (!item->name) {
580 		pr_debug("%s: strdup failed\n", __func__);
581 		free(item);
582 		return NULL;
583 	}
584 
585 	list_add_tail(&item->node, &section->items);
586 	return item;
587 }
588 
589 static int set_value(struct perf_config_item *item, const char *value)
590 {
591 	char *val = strdup(value);
592 
593 	if (!val)
594 		return -1;
595 
596 	zfree(&item->value);
597 	item->value = val;
598 	return 0;
599 }
600 
601 static int collect_config(const char *var, const char *value,
602 			  void *perf_config_set)
603 {
604 	int ret = -1;
605 	char *ptr, *key;
606 	char *section_name, *name;
607 	struct perf_config_section *section = NULL;
608 	struct perf_config_item *item = NULL;
609 	struct perf_config_set *set = perf_config_set;
610 	struct list_head *sections;
611 
612 	if (set == NULL)
613 		return -1;
614 
615 	sections = &set->sections;
616 	key = ptr = strdup(var);
617 	if (!key) {
618 		pr_debug("%s: strdup failed\n", __func__);
619 		return -1;
620 	}
621 
622 	section_name = strsep(&ptr, ".");
623 	name = ptr;
624 	if (name == NULL || value == NULL)
625 		goto out_free;
626 
627 	section = find_section(sections, section_name);
628 	if (!section) {
629 		section = add_section(sections, section_name);
630 		if (!section)
631 			goto out_free;
632 	}
633 
634 	item = find_config_item(name, section);
635 	if (!item) {
636 		item = add_config_item(section, name);
637 		if (!item)
638 			goto out_free;
639 	}
640 
641 	ret = set_value(item, value);
642 	return ret;
643 
644 out_free:
645 	free(key);
646 	return -1;
647 }
648 
649 static int perf_config_set__init(struct perf_config_set *set)
650 {
651 	int ret = -1;
652 	const char *home = NULL;
653 
654 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
655 	if (config_exclusive_filename)
656 		return perf_config_from_file(collect_config, config_exclusive_filename, set);
657 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
658 		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
659 			goto out;
660 	}
661 
662 	home = getenv("HOME");
663 	if (perf_config_global() && home) {
664 		char *user_config = strdup(mkpath("%s/.perfconfig", home));
665 		struct stat st;
666 
667 		if (user_config == NULL) {
668 			warning("Not enough memory to process %s/.perfconfig, "
669 				"ignoring it.", home);
670 			goto out;
671 		}
672 
673 		if (stat(user_config, &st) < 0)
674 			goto out_free;
675 
676 		if (st.st_uid && (st.st_uid != geteuid())) {
677 			warning("File %s not owned by current user or root, "
678 				"ignoring it.", user_config);
679 			goto out_free;
680 		}
681 
682 		if (!st.st_size)
683 			goto out_free;
684 
685 		ret = perf_config_from_file(collect_config, user_config, set);
686 
687 out_free:
688 		free(user_config);
689 	}
690 out:
691 	return ret;
692 }
693 
694 struct perf_config_set *perf_config_set__new(void)
695 {
696 	struct perf_config_set *set = zalloc(sizeof(*set));
697 
698 	if (set) {
699 		INIT_LIST_HEAD(&set->sections);
700 		if (perf_config_set__init(set) < 0) {
701 			perf_config_set__delete(set);
702 			set = NULL;
703 		}
704 	}
705 
706 	return set;
707 }
708 
709 static void perf_config_item__delete(struct perf_config_item *item)
710 {
711 	zfree(&item->name);
712 	zfree(&item->value);
713 	free(item);
714 }
715 
716 static void perf_config_section__purge(struct perf_config_section *section)
717 {
718 	struct perf_config_item *item, *tmp;
719 
720 	list_for_each_entry_safe(item, tmp, &section->items, node) {
721 		list_del_init(&item->node);
722 		perf_config_item__delete(item);
723 	}
724 }
725 
726 static void perf_config_section__delete(struct perf_config_section *section)
727 {
728 	perf_config_section__purge(section);
729 	zfree(&section->name);
730 	free(section);
731 }
732 
733 static void perf_config_set__purge(struct perf_config_set *set)
734 {
735 	struct perf_config_section *section, *tmp;
736 
737 	list_for_each_entry_safe(section, tmp, &set->sections, node) {
738 		list_del_init(&section->node);
739 		perf_config_section__delete(section);
740 	}
741 }
742 
743 void perf_config_set__delete(struct perf_config_set *set)
744 {
745 	if (set == NULL)
746 		return;
747 
748 	perf_config_set__purge(set);
749 	free(set);
750 }
751 
752 /*
753  * Call this to report error for your variable that should not
754  * get a boolean value (i.e. "[my] var" means "true").
755  */
756 int config_error_nonbool(const char *var)
757 {
758 	return error("Missing value for '%s'", var);
759 }
760 
761 void set_buildid_dir(const char *dir)
762 {
763 	if (dir)
764 		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
765 
766 	/* default to $HOME/.debug */
767 	if (buildid_dir[0] == '\0') {
768 		char *home = getenv("HOME");
769 
770 		if (home) {
771 			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
772 				 home, DEBUG_CACHE_DIR);
773 		} else {
774 			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
775 		}
776 		buildid_dir[MAXPATHLEN-1] = '\0';
777 	}
778 	/* for communicating with external commands */
779 	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
780 }
781