xref: /netbsd-src/usr.bin/xlint/lint1/mem1.c (revision 528ce0b18ee40383f14928382d06afd754b01561)
1 /*	$NetBSD: mem1.c,v 1.65 2023/04/11 19:02:19 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)
40 __RCSID("$NetBSD: mem1.c,v 1.65 2023/04/11 19:02:19 rillig Exp $");
41 #endif
42 
43 #include <sys/param.h>
44 #include <stdlib.h>
45 #include <string.h>
46 
47 #include "lint1.h"
48 
49 /*
50  * Filenames allocated by record_filename are shared and have unlimited
51  * lifetime.
52  */
53 struct filename {
54 	const char *fn_name;
55 	size_t	fn_len;
56 	int	fn_id;
57 	struct	filename *fn_next;
58 };
59 
60 static struct filename *filenames;	/* null-terminated array */
61 static int next_filename_id;
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 	const char *orig;
78 	size_t orig_len;
79 	const char *repl;
80 	const 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 	(void)snprintf(buf, sizeof(buf), "%s%s", r->repl, name + r->orig_len);
115 	return buf;
116 }
117 
118 /*
119  * Return a copy of the filename s with unlimited lifetime.
120  * If the filename is new, write it to the output file.
121  */
122 const char *
123 record_filename(const char *s, size_t slen)
124 {
125 
126 	const struct filename *existing_fn = search_filename(s, slen);
127 	if (existing_fn != NULL)
128 		return existing_fn->fn_name;
129 
130 	char *name = xmalloc(slen + 1);
131 	(void)memcpy(name, s, slen);
132 	name[slen] = '\0';
133 
134 	struct filename *fn = xmalloc(sizeof(*fn));
135 	fn->fn_name = name;
136 	fn->fn_len = slen;
137 	fn->fn_id = next_filename_id++;
138 	fn->fn_next = filenames;
139 	filenames = fn;
140 
141 	/* Write the ID of this filename to the output file. */
142 	outclr();
143 	outint(fn->fn_id);
144 	outchar('s');
145 	outstrg(transform_filename(fn->fn_name, fn->fn_len));
146 
147 	return fn->fn_name;
148 }
149 
150 /* Get the ID of a filename. */
151 int
152 get_filename_id(const char *s)
153 {
154 	const struct filename *fn;
155 
156 	if (s == NULL || (fn = search_filename(s, strlen(s))) == NULL)
157 		return -1;
158 	return fn->fn_id;
159 }
160 
161 typedef struct memory_pools {
162 	struct memory_pool *pools;
163 	size_t	cap;
164 } memory_pools;
165 
166 /* Array of memory pools, indexed by mem_block_level. */
167 static memory_pools mpools;
168 
169 /* The pool for the current expression is independent of any block level. */
170 static memory_pool expr_pool;
171 
172 static void
173 mpool_add(memory_pool *pool, void *item)
174 {
175 
176 	if (pool->len >= pool->cap) {
177 		pool->cap = 2 * pool->len + 16;
178 		pool->items = xrealloc(pool->items,
179 		    sizeof(*pool->items) * pool->cap);
180 	}
181 	pool->items[pool->len++] = item;
182 }
183 
184 static void
185 mpool_free(memory_pool *pool)
186 {
187 
188 	for (; pool->len > 0; pool->len--)
189 		free(pool->items[pool->len - 1]);
190 }
191 
192 static void *
193 mpool_zero_alloc(memory_pool *pool, size_t size)
194 {
195 
196 	void *mem = xmalloc(size);
197 	memset(mem, 0, size);
198 	mpool_add(pool, mem);
199 	return mem;
200 }
201 
202 static memory_pool *
203 mpool_at(size_t level)
204 {
205 
206 	if (level >= mpools.cap) {
207 		size_t prev_cap = mpools.cap;
208 		mpools.cap = level + 16;
209 		mpools.pools = xrealloc(mpools.pools,
210 		    sizeof(*mpools.pools) * mpools.cap);
211 		for (size_t i = prev_cap; i < mpools.cap; i++)
212 			mpools.pools[i] = (memory_pool){ NULL, 0, 0 };
213 	}
214 	return mpools.pools + level;
215 }
216 
217 
218 /* Allocate memory associated with level l, initialized with zero. */
219 void *
220 level_zero_alloc(size_t l, size_t s)
221 {
222 
223 	return mpool_zero_alloc(mpool_at(l), s);
224 }
225 
226 /* Allocate memory that is freed at the end of the current block. */
227 void *
228 block_zero_alloc(size_t s)
229 {
230 
231 	return level_zero_alloc(mem_block_level, s);
232 }
233 
234 void
235 level_free_all(size_t level)
236 {
237 
238 	mpool_free(mpool_at(level));
239 }
240 
241 /* Allocate memory that is freed at the end of the current expression. */
242 void *
243 expr_zero_alloc(size_t s)
244 {
245 
246 	return mpool_zero_alloc(&expr_pool, s);
247 }
248 
249 static bool
250 str_endswith(const char *haystack, const char *needle)
251 {
252 	size_t hlen = strlen(haystack);
253 	size_t nlen = strlen(needle);
254 
255 	return nlen <= hlen &&
256 	       memcmp(haystack + hlen - nlen, needle, nlen) == 0;
257 }
258 
259 /*
260  * Return a freshly allocated tree node that is freed at the end of the
261  * current expression.
262  *
263  * The node records whether it comes from a system file, which makes strict
264  * bool mode less restrictive.
265  */
266 tnode_t *
267 expr_alloc_tnode(void)
268 {
269 	tnode_t *tn = expr_zero_alloc(sizeof(*tn));
270 	/*
271 	 * files named *.c that are different from the main translation unit
272 	 * typically contain generated code that cannot be influenced, such
273 	 * as a flex lexer or a yacc parser.
274 	 */
275 	tn->tn_sys = in_system_header ||
276 		     (curr_pos.p_file != csrc_pos.p_file &&
277 		      str_endswith(curr_pos.p_file, ".c"));
278 	return tn;
279 }
280 
281 /* Free all memory which is allocated by the current expression. */
282 void
283 expr_free_all(void)
284 {
285 
286 	mpool_free(&expr_pool);
287 }
288 
289 /*
290  * Save the memory which is used by the current expression. This memory
291  * is not freed by the next expr_free_all() call. The returned value can be
292  * used to restore the memory.
293  */
294 memory_pool
295 expr_save_memory(void)
296 {
297 
298 	memory_pool saved_pool = expr_pool;
299 	expr_pool = (memory_pool){ NULL, 0, 0 };
300 	return saved_pool;
301 }
302 
303 /*
304  * Free all memory used for the current expression and restore the memory used
305  * by a previous expression and saved by expr_save_memory(). The next call to
306  * expr_free_all() frees the restored memory.
307  */
308 void
309 expr_restore_memory(memory_pool saved_pool)
310 {
311 
312 	expr_free_all();
313 	free(expr_pool.items);
314 	expr_pool = saved_pool;
315 }
316