xref: /openbmc/linux/tools/perf/util/config.c (revision f3539c12) 
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 			return -1;
391 		strncpy(buildid_dir, dir, MAXPATHLEN-1);
392 		buildid_dir[MAXPATHLEN-1] = '\0';
393 	}
394 
395 	return 0;
396 }
397 
398 static int perf_default_core_config(const char *var __maybe_unused,
399 				    const char *value __maybe_unused)
400 {
401 	/* Add other config variables here. */
402 	return 0;
403 }
404 
405 static int perf_ui_config(const char *var, const char *value)
406 {
407 	/* Add other config variables here. */
408 	if (!strcmp(var, "ui.show-headers")) {
409 		symbol_conf.show_hist_headers = perf_config_bool(var, value);
410 		return 0;
411 	}
412 	return 0;
413 }
414 
415 int perf_default_config(const char *var, const char *value,
416 			void *dummy __maybe_unused)
417 {
418 	if (!prefixcmp(var, "core."))
419 		return perf_default_core_config(var, value);
420 
421 	if (!prefixcmp(var, "hist."))
422 		return perf_hist_config(var, value);
423 
424 	if (!prefixcmp(var, "ui."))
425 		return perf_ui_config(var, value);
426 
427 	if (!prefixcmp(var, "call-graph."))
428 		return perf_callchain_config(var, value);
429 
430 	if (!prefixcmp(var, "llvm."))
431 		return perf_llvm_config(var, value);
432 
433 	if (!prefixcmp(var, "buildid."))
434 		return perf_buildid_config(var, value);
435 
436 	/* Add other config variables here. */
437 	return 0;
438 }
439 
440 static int perf_config_from_file(config_fn_t fn, const char *filename, void *data)
441 {
442 	int ret;
443 	FILE *f = fopen(filename, "r");
444 
445 	ret = -1;
446 	if (f) {
447 		config_file = f;
448 		config_file_name = filename;
449 		config_linenr = 1;
450 		config_file_eof = 0;
451 		ret = perf_parse_file(fn, data);
452 		fclose(f);
453 		config_file_name = NULL;
454 	}
455 	return ret;
456 }
457 
458 const char *perf_etc_perfconfig(void)
459 {
460 	static const char *system_wide;
461 	if (!system_wide)
462 		system_wide = system_path(ETC_PERFCONFIG);
463 	return system_wide;
464 }
465 
466 static int perf_env_bool(const char *k, int def)
467 {
468 	const char *v = getenv(k);
469 	return v ? perf_config_bool(k, v) : def;
470 }
471 
472 static int perf_config_system(void)
473 {
474 	return !perf_env_bool("PERF_CONFIG_NOSYSTEM", 0);
475 }
476 
477 static int perf_config_global(void)
478 {
479 	return !perf_env_bool("PERF_CONFIG_NOGLOBAL", 0);
480 }
481 
482 static struct perf_config_section *find_section(struct list_head *sections,
483 						const char *section_name)
484 {
485 	struct perf_config_section *section;
486 
487 	list_for_each_entry(section, sections, node)
488 		if (!strcmp(section->name, section_name))
489 			return section;
490 
491 	return NULL;
492 }
493 
494 static struct perf_config_item *find_config_item(const char *name,
495 						 struct perf_config_section *section)
496 {
497 	struct perf_config_item *item;
498 
499 	list_for_each_entry(item, &section->items, node)
500 		if (!strcmp(item->name, name))
501 			return item;
502 
503 	return NULL;
504 }
505 
506 static struct perf_config_section *add_section(struct list_head *sections,
507 					       const char *section_name)
508 {
509 	struct perf_config_section *section = zalloc(sizeof(*section));
510 
511 	if (!section)
512 		return NULL;
513 
514 	INIT_LIST_HEAD(&section->items);
515 	section->name = strdup(section_name);
516 	if (!section->name) {
517 		pr_debug("%s: strdup failed\n", __func__);
518 		free(section);
519 		return NULL;
520 	}
521 
522 	list_add_tail(&section->node, sections);
523 	return section;
524 }
525 
526 static struct perf_config_item *add_config_item(struct perf_config_section *section,
527 						const char *name)
528 {
529 	struct perf_config_item *item = zalloc(sizeof(*item));
530 
531 	if (!item)
532 		return NULL;
533 
534 	item->name = strdup(name);
535 	if (!item->name) {
536 		pr_debug("%s: strdup failed\n", __func__);
537 		free(item);
538 		return NULL;
539 	}
540 
541 	list_add_tail(&item->node, &section->items);
542 	return item;
543 }
544 
545 static int set_value(struct perf_config_item *item, const char *value)
546 {
547 	char *val = strdup(value);
548 
549 	if (!val)
550 		return -1;
551 
552 	zfree(&item->value);
553 	item->value = val;
554 	return 0;
555 }
556 
557 static int collect_config(const char *var, const char *value,
558 			  void *perf_config_set)
559 {
560 	int ret = -1;
561 	char *ptr, *key;
562 	char *section_name, *name;
563 	struct perf_config_section *section = NULL;
564 	struct perf_config_item *item = NULL;
565 	struct perf_config_set *set = perf_config_set;
566 	struct list_head *sections;
567 
568 	if (set == NULL)
569 		return -1;
570 
571 	sections = &set->sections;
572 	key = ptr = strdup(var);
573 	if (!key) {
574 		pr_debug("%s: strdup failed\n", __func__);
575 		return -1;
576 	}
577 
578 	section_name = strsep(&ptr, ".");
579 	name = ptr;
580 	if (name == NULL || value == NULL)
581 		goto out_free;
582 
583 	section = find_section(sections, section_name);
584 	if (!section) {
585 		section = add_section(sections, section_name);
586 		if (!section)
587 			goto out_free;
588 	}
589 
590 	item = find_config_item(name, section);
591 	if (!item) {
592 		item = add_config_item(section, name);
593 		if (!item)
594 			goto out_free;
595 	}
596 
597 	ret = set_value(item, value);
598 	return ret;
599 
600 out_free:
601 	free(key);
602 	return -1;
603 }
604 
605 static int perf_config_set__init(struct perf_config_set *set)
606 {
607 	int ret = -1;
608 	const char *home = NULL;
609 
610 	/* Setting $PERF_CONFIG makes perf read _only_ the given config file. */
611 	if (config_exclusive_filename)
612 		return perf_config_from_file(collect_config, config_exclusive_filename, set);
613 	if (perf_config_system() && !access(perf_etc_perfconfig(), R_OK)) {
614 		if (perf_config_from_file(collect_config, perf_etc_perfconfig(), set) < 0)
615 			goto out;
616 	}
617 
618 	home = getenv("HOME");
619 	if (perf_config_global() && home) {
620 		char *user_config = strdup(mkpath("%s/.perfconfig", home));
621 		struct stat st;
622 
623 		if (user_config == NULL) {
624 			warning("Not enough memory to process %s/.perfconfig, "
625 				"ignoring it.", home);
626 			goto out;
627 		}
628 
629 		if (stat(user_config, &st) < 0)
630 			goto out_free;
631 
632 		if (st.st_uid && (st.st_uid != geteuid())) {
633 			warning("File %s not owned by current user or root, "
634 				"ignoring it.", user_config);
635 			goto out_free;
636 		}
637 
638 		if (!st.st_size)
639 			goto out_free;
640 
641 		ret = perf_config_from_file(collect_config, user_config, set);
642 
643 out_free:
644 		free(user_config);
645 	}
646 out:
647 	return ret;
648 }
649 
650 struct perf_config_set *perf_config_set__new(void)
651 {
652 	struct perf_config_set *set = zalloc(sizeof(*set));
653 
654 	if (set) {
655 		INIT_LIST_HEAD(&set->sections);
656 		if (perf_config_set__init(set) < 0) {
657 			perf_config_set__delete(set);
658 			set = NULL;
659 		}
660 	}
661 
662 	return set;
663 }
664 
665 int perf_config(config_fn_t fn, void *data)
666 {
667 	int ret = 0;
668 	char key[BUFSIZ];
669 	struct perf_config_section *section;
670 	struct perf_config_item *item;
671 
672 	if (config_set == NULL)
673 		return -1;
674 
675 	perf_config_set__for_each_entry(config_set, section, item) {
676 		char *value = item->value;
677 
678 		if (value) {
679 			scnprintf(key, sizeof(key), "%s.%s",
680 				  section->name, item->name);
681 			ret = fn(key, value, data);
682 			if (ret < 0) {
683 				pr_err("Error: wrong config key-value pair %s=%s\n",
684 				       key, value);
685 				break;
686 			}
687 		}
688 	}
689 
690 	return ret;
691 }
692 
693 void perf_config__init(void)
694 {
695 	if (config_set == NULL)
696 		config_set = perf_config_set__new();
697 }
698 
699 void perf_config__exit(void)
700 {
701 	perf_config_set__delete(config_set);
702 	config_set = NULL;
703 }
704 
705 void perf_config__refresh(void)
706 {
707 	perf_config__exit();
708 	perf_config__init();
709 }
710 
711 static void perf_config_item__delete(struct perf_config_item *item)
712 {
713 	zfree(&item->name);
714 	zfree(&item->value);
715 	free(item);
716 }
717 
718 static void perf_config_section__purge(struct perf_config_section *section)
719 {
720 	struct perf_config_item *item, *tmp;
721 
722 	list_for_each_entry_safe(item, tmp, &section->items, node) {
723 		list_del_init(&item->node);
724 		perf_config_item__delete(item);
725 	}
726 }
727 
728 static void perf_config_section__delete(struct perf_config_section *section)
729 {
730 	perf_config_section__purge(section);
731 	zfree(&section->name);
732 	free(section);
733 }
734 
735 static void perf_config_set__purge(struct perf_config_set *set)
736 {
737 	struct perf_config_section *section, *tmp;
738 
739 	list_for_each_entry_safe(section, tmp, &set->sections, node) {
740 		list_del_init(&section->node);
741 		perf_config_section__delete(section);
742 	}
743 }
744 
745 void perf_config_set__delete(struct perf_config_set *set)
746 {
747 	if (set == NULL)
748 		return;
749 
750 	perf_config_set__purge(set);
751 	free(set);
752 }
753 
754 /*
755  * Call this to report error for your variable that should not
756  * get a boolean value (i.e. "[my] var" means "true").
757  */
758 int config_error_nonbool(const char *var)
759 {
760 	return error("Missing value for '%s'", var);
761 }
762 
763 void set_buildid_dir(const char *dir)
764 {
765 	if (dir)
766 		scnprintf(buildid_dir, MAXPATHLEN-1, "%s", dir);
767 
768 	/* default to $HOME/.debug */
769 	if (buildid_dir[0] == '\0') {
770 		char *home = getenv("HOME");
771 
772 		if (home) {
773 			snprintf(buildid_dir, MAXPATHLEN-1, "%s/%s",
774 				 home, DEBUG_CACHE_DIR);
775 		} else {
776 			strncpy(buildid_dir, DEBUG_CACHE_DIR, MAXPATHLEN-1);
777 		}
778 		buildid_dir[MAXPATHLEN-1] = '\0';
779 	}
780 	/* for communicating with external commands */
781 	setenv("PERF_BUILDID_DIR", buildid_dir, 1);
782 }
783