xref: /openbmc/linux/tools/perf/util/config.c (revision 94c7b6fc) 
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 }
514