aboutsummaryrefslogtreecommitdiffstats
path: root/tools/perf/util/path.c
blob: fd1f2faaade48542581b481804fb77c739578ce0 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
/*
 * I'm tired of doing "vsnprintf()" etc just to open a
 * file, so here's a "return static buffer with printf"
 * interface for paths.
 *
 * It's obviously not thread-safe. Sue me. But it's quite
 * useful for doing things like
 *
 *   f = open(mkpath("%s/%s.perf", base, name), O_RDONLY);
 *
 * which is what it's designed for.
 */
#include "cache.h"

static char bad_path[] = "/bad-path/";
/*
 * Two hacks:
 */

static const char *get_perf_dir(void)
{
	return ".";
}

size_t strlcpy(char *dest, const char *src, size_t size)
{
	size_t ret = strlen(src);

	if (size) {
		size_t len = (ret >= size) ? size - 1 : ret;
		memcpy(dest, src, len);
		dest[len] = '\0';
	}
	return ret;
}


static char *get_pathname(void)
{
	static char pathname_array[4][PATH_MAX];
	static int idx;

	return pathname_array[3 & ++idx];
}

static char *cleanup_path(char *path)
{
	/* Clean it up */
	if (!memcmp(path, "./", 2)) {
		path += 2;
		while (*path == '/')
			path++;
	}
	return path;
}

char *mksnpath(char *buf, size_t n, const char *fmt, ...)
{
	va_list args;
	unsigned len;

	va_start(args, fmt);
	len = vsnprintf(buf, n, fmt, args);
	va_end(args);
	if (len >= n) {
		strlcpy(buf, bad_path, n);
		return buf;
	}
	return cleanup_path(buf);
}

static char *perf_vsnpath(char *buf, size_t n, const char *fmt, va_list args)
{
	const char *perf_dir = get_perf_dir();
	size_t len;

	len = strlen(perf_dir);
	if (n < len + 1)
		goto bad;
	memcpy(buf, perf_dir, len);
	if (len && !is_dir_sep(perf_dir[len-1]))
		buf[len++] = '/';
	len += vsnprintf(buf + len, n - len, fmt, args);
	if (len >= n)
		goto bad;
	return cleanup_path(buf);
bad:
	strlcpy(buf, bad_path, n);
	return buf;
}

char *perf_snpath(char *buf, size_t n, const char *fmt, ...)
{
	va_list args;
	va_start(args, fmt);
	(void)perf_vsnpath(buf, n, fmt, args);
	va_end(args);
	return buf;
}

char *perf_pathdup(const char *fmt, ...)
{
	char path[PATH_MAX];
	va_list args;
	va_start(args, fmt);
	(void)perf_vsnpath(path, sizeof(path), fmt, args);
	va_end(args);
	return xstrdup(path);
}

char *mkpath(const char *fmt, ...)
{
	va_list args;
	unsigned len;
	char *pathname = get_pathname();

	va_start(args, fmt);
	len = vsnprintf(pathname, PATH_MAX, fmt, args);
	va_end(args);
	if (len >= PATH_MAX)
		return bad_path;
	return cleanup_path(pathname);
}

char *perf_path(const char *fmt, ...)
{
	const char *perf_dir = get_perf_dir();
	char *pathname = get_pathname();
	va_list args;
	unsigned len;

	len = strlen(perf_dir);
	if (len > PATH_MAX-100)
		return bad_path;
	memcpy(pathname, perf_dir, len);
	if (len && perf_dir[len-1] != '/')
		pathname[len++] = '/';
	va_start(args, fmt);
	len += vsnprintf(pathname + len, PATH_MAX - len, fmt, args);
	va_end(args);
	if (len >= PATH_MAX)
		return bad_path;
	return cleanup_path(pathname);
}


/* perf_mkstemp() - create tmp file honoring TMPDIR variable */
int perf_mkstemp(char *path, size_t len, const char *template)
{
	const char *tmp;
	size_t n;

	tmp = getenv("TMPDIR");
	if (!tmp)
		tmp = "/tmp";
	n = snprintf(path, len, "%s/%s", tmp, template);
	if (len <= n) {
		errno = ENAMETOOLONG;
		return -1;
	}
	return mkstemp(path);
}


const char *make_relative_path(const char *abs_path, const char *base)
{
	static char buf[PATH_MAX + 1];
	int baselen;

	if (!base)
		return abs_path;

	baselen = strlen(base);
	if (prefixcmp(abs_path, base))
		return abs_path;
	if (abs_path[baselen] == '/')
		baselen++;
	else if (base[baselen - 1] != '/')
		return abs_path;

	strcpy(buf, abs_path + baselen);

	return buf;
}

/*
 * It is okay if dst == src, but they should not overlap otherwise.
 *
 * Performs the following normalizations on src, storing the result in dst:
 * - Ensures that components are separated by '/' (Windows only)
 * - Squashes sequences of '/'.
 * - Removes "." components.
 * - Removes ".." components, and the components the precede them.
 * Returns failure (non-zero) if a ".." component appears as first path
 * component anytime during the normalization. Otherwise, returns success (0).
 *
 * Note that this function is purely textual.  It does not follow symlinks,
 * verify the existence of the path, or make any system calls.
 */
int normalize_path_copy(char *dst, const char *src)
{
	char *dst0;

	if (has_dos_drive_prefix(src)) {
		*dst++ = *src++;
		*dst++ = *src++;
	}
	dst0 = dst;

	if (is_dir_sep(*src)) {
		*dst++ = '/';
		while (is_dir_sep(*src))
			src++;
	}

	for (;;) {
		char c = *src;

		/*
		 * A path component that begins with . could be
		 * special:
		 * (1) "." and ends   -- ignore and terminate.
		 * (2) "./"           -- ignore them, eat slash and continue.
		 * (3) ".." and ends  -- strip one and terminate.
		 * (4) "../"          -- strip one, eat slash and continue.
		 */
		if (c == '.') {
			if (!src[1]) {
				/* (1) */
				src++;
			} else if (is_dir_sep(src[1])) {
				/* (2) */
				src += 2;
				while (is_dir_sep(*src))
					src++;
				continue;
			} else if (src[1] == '.') {
				if (!src[2]) {
					/* (3) */
					src += 2;
					goto up_one;
				} else if (is_dir_sep(src[2])) {
					/* (4) */
					src += 3;
					while (is_dir_sep(*src))
						src++;
					goto up_one;
				}
			}
		}

		/* copy up to the next '/', and eat all '/' */
		while ((c = *src++) != '\0' && !is_dir_sep(c))
			*dst++ = c;
		if (is_dir_sep(c)) {
			*dst++ = '/';
			while (is_dir_sep(c))
				c = *src++;
			src--;
		} else if (!c)
			break;
		continue;

	up_one:
		/*
		 * dst0..dst is prefix portion, and dst[-1] is '/';
		 * go up one level.
		 */
		dst--;	/* go to trailing '/' */
		if (dst <= dst0)
			return -1;
		/* Windows: dst[-1] cannot be backslash anymore */
		while (dst0 < dst && dst[-1] != '/')
			dst--;
	}
	*dst = '\0';
	return 0;
}

/*
 * path = Canonical absolute path
 * prefix_list = Colon-separated list of absolute paths
 *
 * Determines, for each path in prefix_list, whether the "prefix" really
 * is an ancestor directory of path.  Returns the length of the longest
 * ancestor directory, excluding any trailing slashes, or -1 if no prefix
 * is an ancestor.  (Note that this means 0 is returned if prefix_list is
 * "/".) "/foo" is not considered an ancestor of "/foobar".  Directories
 * are not considered to be their own ancestors.  path must be in a
 * canonical form: empty components, or "." or ".." components are not
 * allowed.  prefix_list may be null, which is like "".
 */
int longest_ancestor_length(const char *path, const char *prefix_list)
{
	char buf[PATH_MAX+1];
	const char *ceil, *colon;
	int len, max_len = -1;

	if (prefix_list == NULL || !strcmp(path, "/"))
		return -1;

	for (colon = ceil = prefix_list; *colon; ceil = colon+1) {
		for (colon = ceil; *colon && *colon != PATH_SEP; colon++);
		len = colon - ceil;
		if (len == 0 || len > PATH_MAX || !is_absolute_path(ceil))
			continue;
		strlcpy(buf, ceil, len+1);
		if (normalize_path_copy(buf, buf) < 0)
			continue;
		len = strlen(buf);
		if (len > 0 && buf[len-1] == '/')
			buf[--len] = '\0';

		if (!strncmp(path, buf, len) &&
		    path[len] == '/' &&
		    len > max_len) {
			max_len = len;
		}
	}

	return max_len;
}

/* strip arbitrary amount of directory separators at end of path */
static inline int chomp_trailing_dir_sep(const char *path, int len)
{
	while (len && is_dir_sep(path[len - 1]))
		len--;
	return len;
}

/*
 * If path ends with suffix (complete path components), returns the
 * part before suffix (sans trailing directory separators).
 * Otherwise returns NULL.
 */
char *strip_path_suffix(const char *path, const char *suffix)
{
	int path_len = strlen(path), suffix_len = strlen(suffix);

	while (suffix_len) {
		if (!path_len)
			return NULL;

		if (is_dir_sep(path[path_len - 1])) {
			if (!is_dir_sep(suffix[suffix_len - 1]))
				return NULL;
			path_len = chomp_trailing_dir_sep(path, path_len);
			suffix_len = chomp_trailing_dir_sep(suffix, suffix_len);
		}
		else if (path[--path_len] != suffix[--suffix_len])
			return NULL;
	}

	if (path_len && !is_dir_sep(path[path_len - 1]))
		return NULL;
	return xstrndup(path, chomp_trailing_dir_sep(path, path_len));
}