xref: /netbsd-src/usr.bin/xlint/lint1/mem1.c (revision d16b7486a53dcb8072b60ec6fcb4373a2d0c27b7)
1 /*	$NetBSD: mem1.c,v 1.73 2023/07/30 08:58:54 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 1.73 2023/07/30 08:58:54 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 = (size_t)(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, struct memory_pool_item 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 #ifdef DEBUG_MEM
185 static void
186 debug_memory_pool_item(const struct memory_pool_item *item)
187 {
188 	void *p = item->p;
189 	size_t size = item->size;
190 	const char *descr = item->descr;
191 
192 	if (strcmp(descr, "string") == 0) {
193 		const char *str = p;
194 		debug_step("%s: freeing string '%s'", __func__, str);
195 	} else if (strcmp(descr, "sym") == 0) {
196 		const sym_t *sym = p;
197 		debug_step("%s: freeing symbol '%s'", __func__, sym->s_name);
198 	} else if (strcmp(descr, "type") == 0) {
199 		const type_t *tp = p;
200 		debug_step("%s: freeing type '%s'", __func__, type_name(tp));
201 	} else if (strcmp(descr, "tnode") == 0) {
202 		const tnode_t *tn = p;
203 		debug_step("%s: freeing node '%s' with type '%s'",
204 		    __func__, op_name(tn->tn_op), type_name(tn->tn_type));
205 	} else
206 		debug_step("%s: freeing '%s' with %zu bytes",
207 		    __func__, descr, size);
208 }
209 #endif
210 
211 static void
212 mpool_free(memory_pool *pool)
213 {
214 
215 #ifdef DEBUG_MEM
216 	for (size_t i = pool->len; i-- > 0; )
217 		debug_memory_pool_item(pool->items + i);
218 #endif
219 
220 	for (size_t i = pool->len; i-- > 0;) {
221 #ifdef DEBUG_MEM
222 		static void *(*volatile set)(void *, int, size_t) = memset;
223 		set(pool->items[i].p, 'Z', pool->items[i].size);
224 #endif
225 		free(pool->items[i].p);
226 	}
227 	pool->len = 0;
228 }
229 
230 static void *
231 #ifdef DEBUG_MEM
232 mpool_zero_alloc(memory_pool *pool, size_t size, const char *descr)
233 #else
234 mpool_zero_alloc(memory_pool *pool, size_t size)
235 #endif
236 {
237 
238 	void *mem = xmalloc(size);
239 	memset(mem, 0, size);
240 #if DEBUG_MEM
241 	mpool_add(pool, (struct memory_pool_item){ mem, size, descr });
242 #else
243 	mpool_add(pool, (struct memory_pool_item){ mem });
244 #endif
245 	return mem;
246 }
247 
248 static memory_pool *
249 mpool_at(size_t level)
250 {
251 
252 	if (level >= mpools.cap) {
253 		size_t prev_cap = mpools.cap;
254 		mpools.cap = level + 16;
255 		mpools.pools = xrealloc(mpools.pools,
256 		    sizeof(*mpools.pools) * mpools.cap);
257 		for (size_t i = prev_cap; i < mpools.cap; i++)
258 			mpools.pools[i] = (memory_pool){ NULL, 0, 0 };
259 	}
260 	return mpools.pools + level;
261 }
262 
263 
264 /* Allocate memory associated with the level, initialized with zero. */
265 #ifdef DEBUG_MEM
266 void *
267 level_zero_alloc(size_t level, size_t size, const char *descr)
268 {
269 
270 	debug_step("%s: %s at level %zu", __func__, descr, level);
271 	return mpool_zero_alloc(mpool_at(level), size, descr);
272 }
273 #else
274 void *
275 (level_zero_alloc)(size_t level, size_t size)
276 {
277 
278 	return mpool_zero_alloc(mpool_at(level), size);
279 }
280 #endif
281 
282 /* Allocate memory that is freed at the end of the current block. */
283 #ifdef DEBUG_MEM
284 void *
285 block_zero_alloc(size_t size, const char *descr)
286 {
287 
288 	return level_zero_alloc(mem_block_level, size, descr);
289 }
290 #else
291 void *
292 (block_zero_alloc)(size_t size)
293 {
294 
295 	return (level_zero_alloc)(mem_block_level, size);
296 }
297 #endif
298 
299 void
300 level_free_all(size_t level)
301 {
302 
303 	debug_step("+ %s %zu", __func__, level);
304 	debug_indent_inc();
305 	mpool_free(mpool_at(level));
306 	debug_leave();
307 }
308 
309 /* Allocate memory that is freed at the end of the current expression. */
310 #if DEBUG_MEM
311 void *
312 expr_zero_alloc(size_t s, const char *descr)
313 {
314 
315 	return mpool_zero_alloc(&expr_pool, s, descr);
316 }
317 #else
318 void *
319 (expr_zero_alloc)(size_t size)
320 {
321 
322 	return mpool_zero_alloc(&expr_pool, size);
323 }
324 #endif
325 
326 static bool
327 str_ends_with(const char *haystack, const char *needle)
328 {
329 	size_t hlen = strlen(haystack);
330 	size_t nlen = strlen(needle);
331 
332 	return nlen <= hlen &&
333 	       memcmp(haystack + hlen - nlen, needle, nlen) == 0;
334 }
335 
336 /*
337  * Return a freshly allocated tree node that is freed at the end of the
338  * current expression.
339  *
340  * The node records whether it comes from a system file, which makes strict
341  * bool mode less restrictive.
342  */
343 tnode_t *
344 expr_alloc_tnode(void)
345 {
346 	tnode_t *tn = expr_zero_alloc(sizeof(*tn), "tnode");
347 	/*
348 	 * files named *.c that are different from the main translation unit
349 	 * typically contain generated code that cannot be influenced, such
350 	 * as a flex lexer or a yacc parser.
351 	 */
352 	tn->tn_sys = in_system_header ||
353 		     (curr_pos.p_file != csrc_pos.p_file &&
354 		      str_ends_with(curr_pos.p_file, ".c"));
355 	return tn;
356 }
357 
358 /* Free all memory which is allocated by the current expression. */
359 void
360 expr_free_all(void)
361 {
362 
363 	debug_step("%s", __func__);
364 	mpool_free(&expr_pool);
365 }
366 
367 /*
368  * Save the memory which is used by the current expression. This memory
369  * is not freed by the next expr_free_all() call. The returned value can be
370  * used to restore the memory.
371  */
372 memory_pool
373 expr_save_memory(void)
374 {
375 
376 	memory_pool saved_pool = expr_pool;
377 	expr_pool = (memory_pool){ NULL, 0, 0 };
378 	return saved_pool;
379 }
380 
381 /*
382  * Free all memory used for the current expression and restore the memory used
383  * by a previous expression and saved by expr_save_memory(). The next call to
384  * expr_free_all() frees the restored memory.
385  */
386 void
387 expr_restore_memory(memory_pool saved_pool)
388 {
389 
390 	expr_free_all();
391 	free(expr_pool.items);
392 	expr_pool = saved_pool;
393 }
394