xref: /netbsd-src/usr.bin/xlint/lint1/mem1.c (revision 5a2e7833b234db34b627d04318995236487b7352)
1 /*	$NetBSD: mem1.c,v 1.77 2023/12/03 18:17:41 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 1.77 2023/12/03 18:17:41 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 *
search_filename(const char * s,size_t len)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
add_directory_replacement(char * arg)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 *
transform_filename(const char * name,size_t len)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 *
record_filename(const char * s,size_t slen)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 	outint(fn->fn_id);
142 	outchar('s');
143 	outstrg(transform_filename(fn->fn_name, fn->fn_len));
144 	outchar('\n');
145 
146 	return fn->fn_name;
147 }
148 
149 /* Get the ID of a filename. */
150 int
get_filename_id(const char * s)151 get_filename_id(const char *s)
152 {
153 	const struct filename *fn;
154 
155 	if (s == NULL || (fn = search_filename(s, strlen(s))) == NULL)
156 		return -1;
157 	return fn->fn_id;
158 }
159 
160 typedef struct memory_pools {
161 	struct memory_pool *pools;
162 	size_t	cap;
163 } memory_pools;
164 
165 /* Array of memory pools, indexed by mem_block_level. */
166 static memory_pools mpools;
167 
168 /* The pool for the current expression is independent of any block level. */
169 static memory_pool expr_pool;
170 
171 static void
mpool_add(memory_pool * pool,struct memory_pool_item item)172 mpool_add(memory_pool *pool, struct memory_pool_item item)
173 {
174 
175 	if (pool->len >= pool->cap) {
176 		pool->cap = 2 * pool->len + 16;
177 		pool->items = xrealloc(pool->items,
178 		    sizeof(*pool->items) * pool->cap);
179 	}
180 	pool->items[pool->len++] = item;
181 }
182 
183 #ifdef DEBUG_MEM
184 static void
debug_memory_pool_item(const struct memory_pool_item * item)185 debug_memory_pool_item(const struct memory_pool_item *item)
186 {
187 	void *p = item->p;
188 	size_t size = item->size;
189 	const char *descr = item->descr;
190 
191 	if (strcmp(descr, "string") == 0) {
192 		const char *str = p;
193 		debug_step("%s: freeing string '%s'", __func__, str);
194 	} else if (strcmp(descr, "sym") == 0) {
195 		const sym_t *sym = p;
196 		debug_step("%s: freeing symbol '%s'", __func__, sym->s_name);
197 	} else if (strcmp(descr, "type") == 0) {
198 		const type_t *tp = p;
199 		debug_step("%s: freeing type '%s'", __func__, type_name(tp));
200 	} else if (strcmp(descr, "tnode") == 0) {
201 		const tnode_t *tn = p;
202 		debug_step("%s: freeing node '%s' with type '%s'",
203 		    __func__, op_name(tn->tn_op), type_name(tn->tn_type));
204 	} else
205 		debug_step("%s: freeing '%s' with %zu bytes",
206 		    __func__, descr, size);
207 }
208 #endif
209 
210 static void
mpool_free(memory_pool * pool)211 mpool_free(memory_pool *pool)
212 {
213 
214 #ifdef DEBUG_MEM
215 	for (size_t i = pool->len; i-- > 0; )
216 		debug_memory_pool_item(pool->items + i);
217 #endif
218 
219 	for (size_t i = pool->len; i-- > 0;) {
220 #ifdef DEBUG_MEM
221 		static void *(*volatile set)(void *, int, size_t) = memset;
222 		set(pool->items[i].p, 'Z', pool->items[i].size);
223 #endif
224 		free(pool->items[i].p);
225 	}
226 	pool->len = 0;
227 }
228 
229 static void *
230 #ifdef DEBUG_MEM
mpool_zero_alloc(memory_pool * pool,size_t size,const char * descr)231 mpool_zero_alloc(memory_pool *pool, size_t size, const char *descr)
232 #else
233 mpool_zero_alloc(memory_pool *pool, size_t size)
234 #endif
235 {
236 
237 	void *mem = xmalloc(size);
238 	memset(mem, 0, size);
239 #if DEBUG_MEM
240 	mpool_add(pool, (struct memory_pool_item){ mem, size, descr });
241 #else
242 	mpool_add(pool, (struct memory_pool_item){ mem });
243 #endif
244 	return mem;
245 }
246 
247 static memory_pool *
mpool_at(size_t level)248 mpool_at(size_t level)
249 {
250 
251 	if (level >= mpools.cap) {
252 		size_t prev_cap = mpools.cap;
253 		mpools.cap = level + 16;
254 		mpools.pools = xrealloc(mpools.pools,
255 		    sizeof(*mpools.pools) * mpools.cap);
256 		for (size_t i = prev_cap; i < mpools.cap; i++)
257 			mpools.pools[i] = (memory_pool){ NULL, 0, 0 };
258 	}
259 	return mpools.pools + level;
260 }
261 
262 
263 /* Allocate memory associated with the level, initialized with zero. */
264 #ifdef DEBUG_MEM
265 void *
level_zero_alloc(size_t level,size_t size,const char * descr)266 level_zero_alloc(size_t level, size_t size, const char *descr)
267 {
268 
269 	debug_step("%s: %s at level %zu", __func__, descr, level);
270 	return mpool_zero_alloc(mpool_at(level), size, descr);
271 }
272 #else
273 void *
274 (level_zero_alloc)(size_t level, size_t size)
275 {
276 
277 	return mpool_zero_alloc(mpool_at(level), size);
278 }
279 #endif
280 
281 /* Allocate memory that is freed at the end of the current block. */
282 #ifdef DEBUG_MEM
283 void *
block_zero_alloc(size_t size,const char * descr)284 block_zero_alloc(size_t size, const char *descr)
285 {
286 
287 	return level_zero_alloc(mem_block_level, size, descr);
288 }
289 #else
290 void *
291 (block_zero_alloc)(size_t size)
292 {
293 
294 	return (level_zero_alloc)(mem_block_level, size);
295 }
296 #endif
297 
298 void
level_free_all(size_t level)299 level_free_all(size_t level)
300 {
301 
302 	debug_step("+ %s %zu", __func__, level);
303 	debug_indent_inc();
304 	mpool_free(mpool_at(level));
305 	debug_leave();
306 }
307 
308 /* Allocate memory that is freed at the end of the current expression. */
309 #if DEBUG_MEM
310 void *
expr_zero_alloc(size_t s,const char * descr)311 expr_zero_alloc(size_t s, const char *descr)
312 {
313 
314 	return mpool_zero_alloc(&expr_pool, s, descr);
315 }
316 #else
317 void *
318 (expr_zero_alloc)(size_t size)
319 {
320 
321 	return mpool_zero_alloc(&expr_pool, size);
322 }
323 #endif
324 
325 static bool
str_ends_with(const char * haystack,const char * needle)326 str_ends_with(const char *haystack, const char *needle)
327 {
328 	size_t hlen = strlen(haystack);
329 	size_t nlen = strlen(needle);
330 
331 	return nlen <= hlen &&
332 	    memcmp(haystack + hlen - nlen, needle, nlen) == 0;
333 }
334 
335 /*
336  * Return a freshly allocated tree node that is freed at the end of the
337  * current expression.
338  *
339  * The node records whether it comes from a system file, which makes strict
340  * bool mode less restrictive.
341  */
342 tnode_t *
expr_alloc_tnode(void)343 expr_alloc_tnode(void)
344 {
345 	tnode_t *tn = expr_zero_alloc(sizeof(*tn), "tnode");
346 	/*
347 	 * files named *.c that are different from the main translation unit
348 	 * typically contain generated code that cannot be influenced, such as
349 	 * a flex lexer or a yacc parser.
350 	 */
351 	tn->tn_sys = in_system_header ||
352 		     (curr_pos.p_file != csrc_pos.p_file &&
353 		      str_ends_with(curr_pos.p_file, ".c"));
354 	return tn;
355 }
356 
357 /* Free all memory which is allocated by the current expression. */
358 void
expr_free_all(void)359 expr_free_all(void)
360 {
361 
362 	debug_step("%s", __func__);
363 	mpool_free(&expr_pool);
364 }
365 
366 /*
367  * Save the memory which is used by the current expression. This memory
368  * is not freed by the next expr_free_all() call. The returned value can be
369  * used to restore the memory.
370  */
371 memory_pool
expr_save_memory(void)372 expr_save_memory(void)
373 {
374 
375 	memory_pool saved_pool = expr_pool;
376 	expr_pool = (memory_pool){ NULL, 0, 0 };
377 	return saved_pool;
378 }
379 
380 /*
381  * Free all memory used for the current expression and restore the memory used
382  * by a previous expression and saved by expr_save_memory(). The next call to
383  * expr_free_all() frees the restored memory.
384  */
385 void
expr_restore_memory(memory_pool saved_pool)386 expr_restore_memory(memory_pool saved_pool)
387 {
388 
389 	expr_free_all();
390 	free(expr_pool.items);
391 	expr_pool = saved_pool;
392 }
393