File: mem.c

package info (click to toggle)
ucpp 1.3.2-2
  • links: PTS
  • area: main
  • in suites: bullseye, buster, sid, stretch
  • size: 500 kB
  • ctags: 1,058
  • sloc: ansic: 7,997; makefile: 66
file content (328 lines) | stat: -rw-r--r-- 7,097 bytes parent folder | download | duplicates (5)
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
/*
 * Memory manipulation routines
 * (c) Thomas Pornin 1998 - 2002
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 4. The name of the authors may not be used to endorse or promote
 *    products derived from this software without specific prior written
 *    permission.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR 
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR 
 * BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
 * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE 
 * OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
 * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

#include "mem.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

/*
 * Shifting a pointer of that some bytes is supposed to satisfy
 * alignment requirements. This is *not* guaranteed by the standard
 * but should work everywhere anyway.
 */
#define ALIGNSHIFT	(sizeof(long) > sizeof(long double) \
			? sizeof(long) : sizeof(long double))

#ifdef AUDIT
void die(void)
{
	abort();
}

static void suicide(unsigned long e)
{
	fprintf(stderr, "ouch: Schrodinger's beef is not dead ! %lx\n", e);
	die();
}
#else
void die(void)
{
	exit(EXIT_FAILURE);
}
#endif

#if defined AUDIT || defined MEM_CHECK || defined MEM_DEBUG
/*
 * This function is equivalent to a malloc(), but will display an error
 * message and exit if the wanted memory is not available
 */
#ifdef MEM_DEBUG
static void *getmem_raw(size_t x)
#else
void *(getmem)(size_t x)
#endif
{
	void *m;

#ifdef AUDIT
	m = malloc(x + ALIGNSHIFT);
#else
	m = malloc(x);
#endif
	if (m == 0) {
		fprintf(stderr, "ouch: malloc() failed\n");
		die();
	}
#ifdef AUDIT
	*((unsigned long *)m) = 0xdeadbeefUL;
	return (void *)(((char *)m) + ALIGNSHIFT);
#else
	return m;
#endif
}
#endif

#ifndef MEM_DEBUG
/*
 * This function is equivalent to a realloc(); if the realloc() call
 * fails, it will try a malloc() and a memcpy(). If not enough memory is
 * available, the program exits with an error message
 */
void *(incmem)(void *m, size_t x, size_t nx)
{
	void *nm;

#ifdef AUDIT
	m = (void *)(((char *)m) - ALIGNSHIFT);
	if (*((unsigned long *)m) != 0xdeadbeefUL)
		suicide(*((unsigned long *)m));
	x += ALIGNSHIFT; nx += ALIGNSHIFT;
#endif
	if (!(nm = realloc(m, nx))) {
		if (x > nx) x = nx;
		nm = (getmem)(nx);
		memcpy(nm, m, x);
		/* free() and not freemem(), because of the Schrodinger beef */
		free(m);
	}
#ifdef AUDIT
	return (void *)(((char *)nm) + ALIGNSHIFT);
#else
	return nm;
#endif
}
#endif

#if defined AUDIT || defined MEM_DEBUG
/*
 * This function frees the given block
 */
#ifdef MEM_DEBUG
static void freemem_raw(void *x)
#else
void (freemem)(void *x)
#endif
{
#ifdef AUDIT
	void *y = (void *)(((char *)x) - ALIGNSHIFT);

	if ((*((unsigned long *)y)) != 0xdeadbeefUL)
		suicide(*((unsigned long *)y));
	*((unsigned long *)y) = 0xfeedbabeUL;
	free(y);
#else
	free(x);
#endif
}
#endif

#ifdef AUDIT
/*
 * This function copies n bytes from src to dest
 */
void *mmv(void *dest, void *src, size_t n)
{
	return memcpy(dest, src, n);
}

/*
 * This function copies n bytes from src to dest
 */
void *mmvwo(void *dest, void *src, size_t n)
{
	return memmove(dest, src, n);
}
#endif

#ifndef MEM_DEBUG
/*
 * This function creates a new char * and fills it with a copy of src
 */
char *(sdup)(char *src)
{
	size_t n = 1 + strlen(src);
	char *x = getmem(n);

	mmv(x, src, n);
	return x;
}
#endif

#ifdef MEM_DEBUG
/*
 * We include here special versions of getmem(), freemem() and incmem()
 * that track allocations and are used to detect memory leaks.
 *
 * Each allocation is referenced in a list, with a serial number.
 */

/*
 * Define "true" functions for applications that need pointers
 * to such functions.
 */
void *(getmem)(size_t n)
{
	return getmem(n);
}

void (freemem)(void *x)
{
	freemem(x);
}

void *(incmem)(void *x, size_t s, size_t ns)
{
	return incmem(x, s, ns);
}

char *(sdup)(char *s)
{
	return sdup(s);
}

static long current_serial = 0L;

/* must be a power of two */
#define MEMDEBUG_MEMG	128U

static struct mem_track {
	void *block;
	long serial;
	char *file;
	int line;
} *mem = 0;

static size_t meml = 0;

static unsigned int current_ptr = 0;

static void *true_incmem(void *x, size_t old_size, size_t new_size)
{
	void * y = realloc(x, new_size);

	if (y == 0) {
		y = malloc(new_size);
		if (y == 0) {
			fprintf(stderr, "ouch: malloc() failed\n");
			die();
		}
		mmv(y, x, old_size < new_size ? old_size : new_size);
		free(x);
	}
	return y;
}

static long find_free_block(void)
{
	unsigned int n;
	size_t i;

	for (i = 0, n = current_ptr; i < meml; i ++) {
		if (mem[n].block == 0) {
			current_ptr = n;
			return n;
		}
		n = (n + 1) & (meml - 1U);
	}
	if (meml == 0) {
		size_t j;

		meml = MEMDEBUG_MEMG;
		mem = malloc(meml * sizeof(struct mem_track));
		current_ptr = 0;
		for (j = 0; j < meml ; j ++) mem[j].block = 0;
	} else {
		size_t j;

		mem = true_incmem(mem, meml * sizeof(struct mem_track),
			2 * meml * sizeof(struct mem_track));
		current_ptr = meml;
		for (j = meml; j < 2 * meml ; j ++) mem[j].block = 0;
		meml *= 2;
	}
	return current_ptr;
}

void *getmem_debug(size_t n, char *file, int line)
{
	void *x = getmem_raw(n + ALIGNSHIFT);
	long i = find_free_block();

	*(long *)x = i;
	mem[i].block = x;
	mem[i].serial = current_serial ++;
	mem[i].file = file;
	mem[i].line = line;
	return (void *)((unsigned char *)x + ALIGNSHIFT);
}

void freemem_debug(void *x, char *file, int line)
{
	void *y = (unsigned char *)x - ALIGNSHIFT;
	long i = *(long *)y;

	if (i < 0 || (size_t)i >= meml || mem[i].block != y) {
		fprintf(stderr, "ouch: freeing free people (from %s:%d)\n",
			file, line);
		die();
	}
	mem[i].block = 0;
	freemem_raw(y);
}

void *incmem_debug(void *x, size_t ol, size_t nl, char *file, int line)
{
	void *y = getmem_debug(nl, file, line);
	mmv(y, x, ol < nl ? ol : nl);
	freemem_debug(x, file, line);
	return y;
}

char *sdup_debug(char *src, char *file, int line)
{
	size_t n = 1 + strlen(src);
	char *x = getmem_debug(n, file, line);

	mmv(x, src, n);
	return x;
}

void report_leaks(void)
{
	size_t i;

	for (i = 0; i < meml; i ++) {
		if (mem[i].block) fprintf(stderr, "leak: serial %ld, %s:%d\n",
			mem[i].serial, mem[i].file, mem[i].line);
	}
}

#endif