xref: /netbsd-src/usr.bin/xlint/lint1/mem1.c (revision 4b896b232495b7a9b8b94a1cf1e21873296d53b8)
1 /*	$NetBSD: mem1.c,v 1.10 2003/10/21 23:58:53 christos 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 #include <sys/cdefs.h>
35 #if defined(__RCSID) && !defined(lint)
36 __RCSID("$NetBSD: mem1.c,v 1.10 2003/10/21 23:58:53 christos Exp $");
37 #endif
38 
39 #include <sys/types.h>
40 #include <sys/param.h>
41 #include <stdlib.h>
42 #include <string.h>
43 #include <unistd.h>
44 
45 #include "lint1.h"
46 
47 /*
48  * Filenames allocated by fnalloc() and fnnalloc() are shared.
49  */
50 typedef struct fn {
51 	char	*fn_name;
52 	size_t	fn_len;
53 	int	fn_id;
54 	struct	fn *fn_nxt;
55 } fn_t;
56 
57 static	fn_t	*fnames;
58 
59 static	fn_t	*srchfn(const char *, size_t);
60 
61 /*
62  * Look for a Filename of length l.
63  */
64 static fn_t *
65 srchfn(const char *s, size_t len)
66 {
67 	fn_t	*fn;
68 
69 	for (fn = fnames; fn != NULL; fn = fn->fn_nxt) {
70 		if (fn->fn_len == len && memcmp(fn->fn_name, s, len) == 0)
71 			break;
72 	}
73 	return (fn);
74 }
75 
76 /*
77  * Return a shared string for filename s.
78  */
79 const char *
80 fnalloc(const char *s)
81 {
82 
83 	return (s != NULL ? fnnalloc(s, strlen(s)) : NULL);
84 }
85 
86 const char *
87 fnnalloc(const char *s, size_t len)
88 {
89 	fn_t	*fn;
90 
91 	static	int	nxt_id = 0;
92 
93 	if (s == NULL)
94 		return (NULL);
95 
96 	if ((fn = srchfn(s, len)) == NULL) {
97 		fn = xmalloc(sizeof (fn_t));
98 		/* Do not used strdup() because string is not NUL-terminated.*/
99 		fn->fn_name = xmalloc(len + 1);
100 		(void)memcpy(fn->fn_name, s, len);
101 		fn->fn_name[len] = '\0';
102 		fn->fn_len = len;
103 		fn->fn_id = nxt_id++;
104 		fn->fn_nxt = fnames;
105 		fnames = fn;
106 		/* Write id of this filename to the output file. */
107 		outclr();
108 		outint(fn->fn_id);
109 		outchar('s');
110 		outstrg(fn->fn_name);
111 	}
112 	return (fn->fn_name);
113 }
114 
115 /*
116  * Get id of a filename.
117  */
118 int
119 getfnid(const char *s)
120 {
121 	fn_t	*fn;
122 
123 	if (s == NULL || (fn = srchfn(s, strlen(s))) == NULL)
124 		return (-1);
125 	return (fn->fn_id);
126 }
127 
128 /*
129  * Memory for declarations and other things which must be available
130  * until the end of a block (or the end of the translation unit)
131  * are assoziated with the level (mblklev) of the block (or wiht 0).
132  * Because these memory is allocated in large blocks associated with
133  * a given level it can be freed easily at the end of a block.
134  */
135 #define	ML_INC	((size_t)32)		/* Increment for length of *mblks */
136 
137 typedef struct mbl {
138 	void	*blk;			/* beginning of memory block */
139 	void	*ffree;			/* first free byte */
140 	size_t	nfree;			/* # of free bytes */
141 	size_t	size;			/* total size of memory block */
142 	struct	mbl *nxt;		/* next block */
143 } mbl_t;
144 
145 /*
146  * Array of pointers to lists of memory blocks. mblklev is used as
147  * index into this array.
148  */
149 static	mbl_t	**mblks;
150 
151 /* number of elements in *mblks */
152 static	size_t	nmblks;
153 
154 /* free list for memory blocks */
155 static	mbl_t	*frmblks;
156 
157 /* length of new allocated memory blocks */
158 static	size_t	mblklen;
159 
160 static	void	*xgetblk(mbl_t **, size_t);
161 static	void	xfreeblk(mbl_t **);
162 static	mbl_t	*xnewblk(void);
163 
164 static mbl_t *
165 xnewblk(void)
166 {
167 	mbl_t	*mb = xmalloc(sizeof (mbl_t));
168 
169 	/* use mmap instead of malloc to avoid malloc's size overhead */
170 	mb->blk = xmapalloc(mblklen);
171 	mb->size = mblklen;
172 
173 	return (mb);
174 }
175 
176 /*
177  * Allocate new memory. If the first block of the list has not enough
178  * free space, or there is no first block, get a new block. The new
179  * block is taken from the free list or, if there is no block on the
180  * free list, is allocated using xnewblk(). If a new block is allocated
181  * it is initialized with zero. Blocks taken from the free list are
182  * zero'd in xfreeblk().
183  */
184 static void *
185 xgetblk(mbl_t **mbp, size_t s)
186 {
187 	mbl_t	*mb;
188 	void	*p;
189 	size_t	t = 0;
190 
191 	s = ALIGN(s);
192 	if ((mb = *mbp) == NULL || mb->nfree < s) {
193 		if ((mb = frmblks) == NULL) {
194 			if (s > mblklen) {
195 				t = mblklen;
196 				mblklen = s;
197 			}
198 			mb = xnewblk();
199 			if (t)
200 				mblklen = t;
201 			(void)memset(mb->blk, 0, mb->size);
202 		} else {
203 			frmblks = mb->nxt;
204 		}
205 		mb->ffree = mb->blk;
206 		mb->nfree = mb->size;
207 		mb->nxt = *mbp;
208 		*mbp = mb;
209 	}
210 	p = mb->ffree;
211 	mb->ffree = (char *)mb->ffree + s;
212 	mb->nfree -= s;
213 	return (p);
214 }
215 
216 /*
217  * Move all blocks from list *fmbp to free list. For each block, set all
218  * used memory to zero.
219  */
220 static void
221 xfreeblk(mbl_t **fmbp)
222 {
223 	mbl_t	*mb;
224 
225 	while ((mb = *fmbp) != NULL) {
226 		*fmbp = mb->nxt;
227 		mb->nxt = frmblks;
228 		frmblks = mb;
229 		(void)memset(mb->blk, 0, mb->size - mb->nfree);
230 	}
231 }
232 
233 void
234 initmem(void)
235 {
236 	int	pgsz;
237 
238 	pgsz = getpagesize();
239 	mblklen = ((MBLKSIZ + pgsz - 1) / pgsz) * pgsz;
240 
241 	mblks = xcalloc(nmblks = ML_INC, sizeof (mbl_t *));
242 }
243 
244 
245 /*
246  * Allocate memory associated with level l.
247  */
248 void *
249 getlblk(int l, size_t s)
250 {
251 
252 	while (l >= nmblks) {
253 		mblks = xrealloc(mblks, (nmblks + ML_INC) * sizeof (mbl_t *));
254 		(void)memset(&mblks[nmblks], 0, ML_INC * sizeof (mbl_t *));
255 		nmblks += ML_INC;
256 	}
257 	return (xgetblk(&mblks[l], s));
258 }
259 
260 void *
261 getblk(size_t s)
262 {
263 
264 	return (getlblk(mblklev, s));
265 }
266 
267 /*
268  * Free all memory associated with level l.
269  */
270 void
271 freelblk(int l)
272 {
273 
274 	xfreeblk(&mblks[l]);
275 }
276 
277 void
278 freeblk(void)
279 {
280 
281 	freelblk(mblklev);
282 }
283 
284 /*
285  * tgetblk() returns memory which is associated with the current
286  * expression.
287  */
288 static	mbl_t	*tmblk;
289 
290 void *
291 tgetblk(size_t s)
292 {
293 
294 	return (xgetblk(&tmblk, s));
295 }
296 
297 /*
298  * Get memory for a new tree node.
299  */
300 tnode_t *
301 getnode(void)
302 {
303 
304 	return (tgetblk(sizeof (tnode_t)));
305 }
306 
307 /*
308  * Free all memory which is allocated by the current expression.
309  */
310 void
311 tfreeblk(void)
312 {
313 
314 	xfreeblk(&tmblk);
315 }
316 
317 /*
318  * Save the memory which is used by the current expression. This memory
319  * is not freed by the next tfreeblk() call. The pointer returned can be
320  * used to restore the memory.
321  */
322 mbl_t *
323 tsave(void)
324 {
325 	mbl_t	*tmem;
326 
327 	tmem = tmblk;
328 	tmblk = NULL;
329 	return (tmem);
330 }
331 
332 /*
333  * Free all memory used for the current expression and the memory used
334  * be a previous expression and saved by tsave(). The next call to
335  * tfreeblk() frees the restored memory.
336  */
337 void
338 trestor(mbl_t *tmem)
339 {
340 
341 	tfreeblk();
342 	if (tmblk != NULL) {
343 		free(tmblk->blk);
344 		free(tmblk);
345 	}
346 	tmblk = tmem;
347 }
348