xref: /netbsd-src/usr.bin/xlint/lint1/mem1.c (revision 82d56013d7b633d116a93943de88e08335357a7c)
1 /*	$NetBSD: mem1.c,v 1.43 2021/04/02 12:16:50 rillig Exp $	*/
2 
3 /*
4  * Copyright (c) 1994, 1995 Jochen Pohl
5  * All Rights Reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. All advertising materials mentioning features or use of this software
16  *    must display the following acknowledgement:
17  *      This product includes software developed by Jochen Pohl for
18  *	The NetBSD Project.
19  * 4. The name of the author may not be used to endorse or promote products
20  *    derived from this software without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
23  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
24  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
25  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
26  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
27  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
31  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 
34 #if HAVE_NBTOOL_CONFIG_H
35 #include "nbtool_config.h"
36 #endif
37 
38 #include <sys/cdefs.h>
39 #if defined(__RCSID) && !defined(lint)
40 __RCSID("$NetBSD: mem1.c,v 1.43 2021/04/02 12:16:50 rillig Exp $");
41 #endif
42 
43 #include <sys/types.h>
44 #include <sys/param.h>
45 #include <stdlib.h>
46 #include <string.h>
47 #include <unistd.h>
48 
49 #include "lint1.h"
50 
51 /*
52  * Filenames allocated by record_filename are shared.
53  */
54 struct filename {
55 	char	*fn_name;
56 	size_t	fn_len;
57 	int	fn_id;
58 	struct	filename *fn_next;
59 };
60 
61 static struct filename *filenames;	/* null-terminated array */
62 
63 /* Find the given filename, or return NULL. */
64 static const struct filename *
65 search_filename(const char *s, size_t len)
66 {
67 	const struct filename *fn;
68 
69 	for (fn = filenames; fn != NULL; fn = fn->fn_next) {
70 		if (fn->fn_len == len && memcmp(fn->fn_name, s, len) == 0)
71 			break;
72 	}
73 	return fn;
74 }
75 
76 struct filename_replacement {
77 	char *orig;
78 	size_t orig_len;
79 	char *repl;
80 	struct filename_replacement *next;
81 };
82 
83 static struct filename_replacement *filename_replacements;
84 
85 void
86 add_directory_replacement(char *arg)
87 {
88 	struct filename_replacement *r = xmalloc(sizeof(*r));
89 
90 	char *sep = strchr(arg, '=');
91 	if (sep == NULL)
92 		err(1, "Bad replacement directory spec `%s'", arg);
93 	*sep = '\0';
94 
95 	r->orig = arg;
96 	r->orig_len = sep - arg;
97 	r->repl = sep + 1;
98 	r->next = filename_replacements;
99 	filename_replacements = r;
100 }
101 
102 const char *
103 transform_filename(const char *name, size_t len)
104 {
105 	static char buf[MAXPATHLEN];
106 	const struct filename_replacement *r;
107 
108 	for (r = filename_replacements; r != NULL; r = r->next)
109 		if (r->orig_len < len &&
110 		    memcmp(name, r->orig, r->orig_len) == 0)
111 			break;
112 	if (r == NULL)
113 		return name;
114 	snprintf(buf, sizeof(buf), "%s%s", r->repl, name + r->orig_len);
115 	return buf;
116 }
117 
118 static int
119 next_filename_id(void)
120 {
121 	static int next_id = 0;
122 
123 	return next_id++;
124 }
125 
126 /*
127  * Return a copy of the filename s with unlimited lifetime.
128  * If the filename is new, write it to the output file.
129  */
130 const char *
131 record_filename(const char *s, size_t slen)
132 {
133 	const struct filename *existing_fn;
134 	struct filename *fn;
135 
136 	if (s == NULL)
137 		return NULL;
138 
139 	if ((existing_fn = search_filename(s, slen)) != NULL)
140 		return existing_fn->fn_name;
141 
142 	fn = xmalloc(sizeof(*fn));
143 	/* Do not use strdup() because s is not NUL-terminated.*/
144 	fn->fn_name = xmalloc(slen + 1);
145 	(void)memcpy(fn->fn_name, s, slen);
146 	fn->fn_name[slen] = '\0';
147 	fn->fn_len = slen;
148 	fn->fn_id = next_filename_id();
149 	fn->fn_next = filenames;
150 	filenames = fn;
151 
152 	/* Write the ID of this filename to the output file. */
153 	outclr();
154 	outint(fn->fn_id);
155 	outchar('s');
156 	outstrg(transform_filename(fn->fn_name, fn->fn_len));
157 
158 	return fn->fn_name;
159 }
160 
161 /* Get the ID of a filename. */
162 int
163 get_filename_id(const char *s)
164 {
165 	const struct filename *fn;
166 
167 	if (s == NULL || (fn = search_filename(s, strlen(s))) == NULL)
168 		return -1;
169 	return fn->fn_id;
170 }
171 
172 /*
173  * Memory for declarations and other things which must be available
174  * until the end of a block (or the end of the translation unit)
175  * is associated with the corresponding mem_block_level, which may be 0.
176  * Because this memory is allocated in large blocks associated with
177  * a given level it can be freed easily at the end of a block.
178  */
179 #define	ML_INC	((size_t)32)		/* Increment for length of *mblks */
180 
181 typedef struct memory_block {
182 	void	*start;			/* beginning of memory block */
183 	void	*first_free;		/* first free byte */
184 	size_t	nfree;			/* # of free bytes */
185 	size_t	size;			/* total size of memory block */
186 	struct	memory_block *next;
187 } memory_block;
188 
189 /*
190  * Array of pointers to lists of memory blocks. mem_block_level is used as
191  * index into this array.
192  */
193 static	memory_block	**mblks;
194 
195 /* number of elements in *mblks */
196 static	size_t	nmblks;
197 
198 /* free list for memory blocks */
199 static	memory_block	*frmblks;
200 
201 /* length of new allocated memory blocks */
202 static	size_t	mblklen;
203 
204 static	void	*xgetblk(memory_block **, size_t);
205 static	void	xfreeblk(memory_block **);
206 static	memory_block *xnewblk(void);
207 
208 static memory_block *
209 xnewblk(void)
210 {
211 	memory_block	*mb = xmalloc(sizeof(*mb));
212 
213 	/* use mmap instead of malloc to avoid malloc's size overhead */
214 	mb->start = xmapalloc(mblklen);
215 	mb->size = mblklen;
216 
217 	return mb;
218 }
219 
220 /* Allocate new memory, initialized with zero. */
221 static void *
222 xgetblk(memory_block **mbp, size_t s)
223 {
224 	memory_block	*mb;
225 	void	*p;
226 	size_t	t = 0;
227 
228 	/*
229 	 * If the first block of the list has not enough free space,
230 	 * or there is no first block, get a new block. The new block
231 	 * is taken from the free list or, if there is no block on the
232 	 * free list, is allocated using xnewblk().
233 	 *
234 	 * If a new block is allocated it is initialized with zero.
235 	 * Blocks taken from the free list are zero'd in xfreeblk().
236 	 */
237 
238 	s = WORST_ALIGN(s);
239 	if ((mb = *mbp) == NULL || mb->nfree < s) {
240 		if ((mb = frmblks) == NULL || mb->size < s) {
241 			if (s > mblklen) {
242 				t = mblklen;
243 				mblklen = s;
244 			}
245 			mb = xnewblk();
246 #ifndef BLKDEBUG
247 			(void)memset(mb->start, 0, mb->size);
248 #endif
249 			if (t > 0)
250 				mblklen = t;
251 		} else {
252 			frmblks = mb->next;
253 		}
254 		mb->first_free = mb->start;
255 		mb->nfree = mb->size;
256 		mb->next = *mbp;
257 		*mbp = mb;
258 	}
259 	p = mb->first_free;
260 	mb->first_free = (char *)mb->first_free + s;
261 	mb->nfree -= s;
262 #ifdef BLKDEBUG
263 	(void)memset(p, 0, s);
264 #endif
265 	return p;
266 }
267 
268 /*
269  * Move all blocks from list *fmbp to free list. For each block, set all
270  * used memory to zero.
271  */
272 static void
273 xfreeblk(memory_block **fmbp)
274 {
275 	memory_block	*mb;
276 
277 	while ((mb = *fmbp) != NULL) {
278 		*fmbp = mb->next;
279 		mb->next = frmblks;
280 		frmblks = mb;
281 		(void)memset(mb->start, ZERO, mb->size - mb->nfree);
282 	}
283 }
284 
285 void
286 initmem(void)
287 {
288 	int	pgsz;
289 
290 	pgsz = getpagesize();
291 	mblklen = ((MBLKSIZ + pgsz - 1) / pgsz) * pgsz;
292 
293 	mblks = xcalloc(nmblks = ML_INC, sizeof(*mblks));
294 }
295 
296 
297 /* Allocate memory associated with level l. */
298 void *
299 getlblk(size_t l, size_t s)
300 {
301 
302 	while (l >= nmblks) {
303 		mblks = xrealloc(mblks, (nmblks + ML_INC) * sizeof(*mblks));
304 		(void)memset(&mblks[nmblks], 0, ML_INC * sizeof(*mblks));
305 		nmblks += ML_INC;
306 	}
307 	return xgetblk(&mblks[l], s);
308 }
309 
310 void *
311 getblk(size_t s)
312 {
313 
314 	return getlblk(mem_block_level, s);
315 }
316 
317 /* Free all memory associated with level l. */
318 void
319 freelblk(int l)
320 {
321 
322 	xfreeblk(&mblks[l]);
323 }
324 
325 void
326 freeblk(void)
327 {
328 
329 	freelblk(mem_block_level);
330 }
331 
332 static	memory_block	*tmblk;
333 
334 /*
335  * Return zero-initialized memory that is freed at the end of the current
336  * expression.
337  */
338 void *
339 expr_zalloc(size_t s)
340 {
341 
342 	return xgetblk(&tmblk, s);
343 }
344 
345 /*
346  * Return a freshly allocated tree node that is freed at the end of the
347  * current expression.
348  */
349 tnode_t *
350 expr_zalloc_tnode(void)
351 {
352 	tnode_t *tn = expr_zalloc(sizeof(*tn));
353 	tn->tn_from_system_header = in_system_header;
354 	return tn;
355 }
356 
357 /* Free all memory which is allocated by the current expression. */
358 void
359 expr_free_all(void)
360 {
361 
362 	xfreeblk(&tmblk);
363 }
364 
365 /*
366  * Save the memory which is used by the current expression. This memory
367  * is not freed by the next expr_free_all() call. The pointer returned can be
368  * used to restore the memory.
369  */
370 memory_block *
371 expr_save_memory(void)
372 {
373 	memory_block	*tmem;
374 
375 	tmem = tmblk;
376 	tmblk = NULL;
377 	return tmem;
378 }
379 
380 /*
381  * Free all memory used for the current expression and the memory used
382  * be a previous expression and saved by expr_save_memory(). The next call to
383  * expr_free_all() frees the restored memory.
384  */
385 void
386 expr_restore_memory(memory_block *tmem)
387 {
388 
389 	expr_free_all();
390 	if (tmblk != NULL) {
391 		free(tmblk->start);
392 		free(tmblk);
393 	}
394 	tmblk = tmem;
395 }
396