xref: /openbmc/linux/tools/perf/util/config.c (revision 7bcae826)
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 }
806