xref: /netbsd-src/usr.bin/xlint/lint1/mem1.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /*	$NetBSD: mem1.c,v 1.64 2023/01/13 19:41:50 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)
40 __RCSID("$NetBSD: mem1.c,v 1.64 2023/01/13 19:41:50 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 	const struct filename *existing_fn;
126 	struct filename *fn;
127 	char *name;
128 
129 	if ((existing_fn = search_filename(s, slen)) != NULL)
130 		return existing_fn->fn_name;
131 
132 	name = xmalloc(slen + 1);
133 	(void)memcpy(name, s, slen);
134 	name[slen] = '\0';
135 
136 	fn = xmalloc(sizeof(*fn));
137 	fn->fn_name = name;
138 	fn->fn_len = slen;
139 	fn->fn_id = next_filename_id++;
140 	fn->fn_next = filenames;
141 	filenames = fn;
142 
143 	/* Write the ID of this filename to the output file. */
144 	outclr();
145 	outint(fn->fn_id);
146 	outchar('s');
147 	outstrg(transform_filename(fn->fn_name, fn->fn_len));
148 
149 	return fn->fn_name;
150 }
151 
152 /* Get the ID of a filename. */
153 int
154 get_filename_id(const char *s)
155 {
156 	const struct filename *fn;
157 
158 	if (s == NULL || (fn = search_filename(s, strlen(s))) == NULL)
159 		return -1;
160 	return fn->fn_id;
161 }
162 
163 /* Array of memory pools, indexed by mem_block_level. */
164 typedef struct memory_pools {
165 	struct memory_pool *pools;
166 	size_t	cap;
167 } memory_pools;
168 
169 static memory_pools mpools;
170 
171 /* The pool for the current expression is independent of any block level. */
172 static memory_pool expr_pool;
173 
174 static void
175 mpool_add(memory_pool *pool, void *item)
176 {
177 
178 	if (pool->len >= pool->cap) {
179 		pool->cap = 2 * pool->len + 16;
180 		pool->items = xrealloc(pool->items,
181 		    sizeof(*pool->items) * pool->cap);
182 	}
183 	pool->items[pool->len++] = item;
184 }
185 
186 static void
187 mpool_free(memory_pool *pool)
188 {
189 
190 	for (; pool->len > 0; pool->len--)
191 		free(pool->items[pool->len - 1]);
192 }
193 
194 static void *
195 mpool_zero_alloc(memory_pool *pool, size_t size)
196 {
197 
198 	void *mem = xmalloc(size);
199 	memset(mem, 0, size);
200 	mpool_add(pool, mem);
201 	return mem;
202 }
203 
204 static memory_pool *
205 mpool_at(size_t level)
206 {
207 
208 	if (level >= mpools.cap) {
209 		size_t prev_cap = mpools.cap;
210 		mpools.cap = level + 16;
211 		mpools.pools = xrealloc(mpools.pools,
212 		    sizeof(*mpools.pools) * mpools.cap);
213 		for (size_t i = prev_cap; i < mpools.cap; i++)
214 			mpools.pools[i] = (memory_pool){ NULL, 0, 0 };
215 	}
216 	return mpools.pools + level;
217 }
218 
219 
220 /* Allocate memory associated with level l, initialized with zero. */
221 void *
222 level_zero_alloc(size_t l, size_t s)
223 {
224 
225 	return mpool_zero_alloc(mpool_at(l), s);
226 }
227 
228 /* Allocate memory that is freed at the end of the current block. */
229 void *
230 block_zero_alloc(size_t s)
231 {
232 
233 	return level_zero_alloc(mem_block_level, s);
234 }
235 
236 void
237 level_free_all(size_t level)
238 {
239 
240 	mpool_free(mpool_at(level));
241 }
242 
243 /* Allocate memory that is freed at the end of the current expression. */
244 void *
245 expr_zero_alloc(size_t s)
246 {
247 
248 	return mpool_zero_alloc(&expr_pool, s);
249 }
250 
251 static bool
252 str_endswith(const char *haystack, const char *needle)
253 {
254 	size_t hlen = strlen(haystack);
255 	size_t nlen = strlen(needle);
256 
257 	return nlen <= hlen &&
258 	       memcmp(haystack + hlen - nlen, needle, nlen) == 0;
259 }
260 
261 /*
262  * Return a freshly allocated tree node that is freed at the end of the
263  * current expression.
264  *
265  * The node records whether it comes from a system file, which makes strict
266  * bool mode less restrictive.
267  */
268 tnode_t *
269 expr_alloc_tnode(void)
270 {
271 	tnode_t *tn = expr_zero_alloc(sizeof(*tn));
272 	/*
273 	 * files named *.c that are different from the main translation unit
274 	 * typically contain generated code that cannot be influenced, such
275 	 * as a flex lexer or a yacc parser.
276 	 */
277 	tn->tn_sys = in_system_header ||
278 		     (curr_pos.p_file != csrc_pos.p_file &&
279 		      str_endswith(curr_pos.p_file, ".c"));
280 	return tn;
281 }
282 
283 /* Free all memory which is allocated by the current expression. */
284 void
285 expr_free_all(void)
286 {
287 
288 	mpool_free(&expr_pool);
289 }
290 
291 /*
292  * Save the memory which is used by the current expression. This memory
293  * is not freed by the next expr_free_all() call. The returned value can be
294  * used to restore the memory.
295  */
296 memory_pool
297 expr_save_memory(void)
298 {
299 
300 	memory_pool saved_pool = expr_pool;
301 	expr_pool = (memory_pool){ NULL, 0, 0 };
302 	return saved_pool;
303 }
304 
305 /*
306  * Free all memory used for the current expression and restore the memory used
307  * by a previous expression and saved by expr_save_memory(). The next call to
308  * expr_free_all() frees the restored memory.
309  */
310 void
311 expr_restore_memory(memory_pool saved_pool)
312 {
313 
314 	expr_free_all();
315 	free(expr_pool.items);
316 	expr_pool = saved_pool;
317 }
318