xref: /freebsd/usr.bin/m4/look.c (revision 8881d206f4e68b564c2c5f50fc717086fc3e827a)
1 /*	$OpenBSD: look.c,v 1.24 2014/12/21 09:33:12 espie Exp $	*/
2 
3 /*-
4  * SPDX-License-Identifier: BSD-3-Clause
5  *
6  * Copyright (c) 1989, 1993
7  *	The Regents of the University of California.  All rights reserved.
8  *
9  * This code is derived from software contributed to Berkeley by
10  * Ozan Yigit at York University.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  * 3. Neither the name of the University nor the names of its contributors
21  *    may be used to endorse or promote products derived from this software
22  *    without specific prior written permission.
23  *
24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34  * SUCH DAMAGE.
35  */
36 #include <sys/cdefs.h>
37 __FBSDID("$FreeBSD$");
38 
39 /*
40  * look.c
41  * Facility: m4 macro processor
42  * by: oz
43  */
44 
45 #include <sys/types.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <stdint.h>
49 #include <stddef.h>
50 #include <string.h>
51 #include <ohash.h>
52 #include "mdef.h"
53 #include "stdd.h"
54 #include "extern.h"
55 
56 static void *hash_calloc(size_t, size_t, void *);
57 static void hash_free(void *, void *);
58 static void *element_alloc(size_t, void *);
59 static void setup_definition(struct macro_definition *, const char *,
60     const char *);
61 static void free_definition(char *);
62 static void keep(char *);
63 static int string_in_use(const char *);
64 
65 static struct ohash_info macro_info = {
66 	offsetof(struct ndblock, name),
67 	NULL, hash_calloc, hash_free, element_alloc };
68 
69 struct ohash macros;
70 
71 /* Support routines for hash tables.  */
72 void *
73 hash_calloc(size_t n, size_t s, void *u __unused)
74 {
75 	void *storage = xcalloc(n, s, "hash alloc");
76 	return storage;
77 }
78 
79 void
80 hash_free(void *p, void *u __unused)
81 {
82 	free(p);
83 }
84 
85 void *
86 element_alloc(size_t s, void *u __unused)
87 {
88 	return xalloc(s, "element alloc");
89 }
90 
91 void
92 init_macros(void)
93 {
94 	ohash_init(&macros, 10, &macro_info);
95 }
96 
97 /*
98  * find name in the hash table
99  */
100 ndptr
101 lookup(const char *name)
102 {
103 	return ohash_find(&macros, ohash_qlookup(&macros, name));
104 }
105 
106 struct macro_definition *
107 lookup_macro_definition(const char *name)
108 {
109 	ndptr p;
110 
111 	p = ohash_find(&macros, ohash_qlookup(&macros, name));
112 	if (p)
113 		return p->d;
114 	else
115 		return NULL;
116 }
117 
118 static void
119 setup_definition(struct macro_definition *d, const char *defn, const char *name)
120 {
121 	ndptr p;
122 
123 	if (strncmp(defn, BUILTIN_MARKER, sizeof(BUILTIN_MARKER)-1) == 0 &&
124 	    (p = macro_getbuiltin(defn+sizeof(BUILTIN_MARKER)-1)) != NULL) {
125 		d->type = macro_builtin_type(p);
126 		d->defn = xstrdup(defn+sizeof(BUILTIN_MARKER)-1);
127 	} else {
128 		if (!*defn)
129 			d->defn = __DECONST(char *, null);
130 		else
131 			d->defn = xstrdup(defn);
132 		d->type = MACRTYPE;
133 	}
134 	if (STREQ(name, defn))
135 		d->type |= RECDEF;
136 }
137 
138 static ndptr
139 create_entry(const char *name)
140 {
141 	const char *end = NULL;
142 	unsigned int i;
143 	ndptr n;
144 
145 	i = ohash_qlookupi(&macros, name, &end);
146 	n = ohash_find(&macros, i);
147 	if (n == NULL) {
148 		n = ohash_create_entry(&macro_info, name, &end);
149 		ohash_insert(&macros, i, n);
150 		n->trace_flags = FLAG_NO_TRACE;
151 		n->builtin_type = MACRTYPE;
152 		n->d = NULL;
153 	}
154 	return n;
155 }
156 
157 void
158 macro_define(const char *name, const char *defn)
159 {
160 	ndptr n = create_entry(name);
161 	if (n->d != NULL) {
162 		if (n->d->defn != null)
163 			free_definition(n->d->defn);
164 	} else {
165 		n->d = xalloc(sizeof(struct macro_definition), NULL);
166 		n->d->next = NULL;
167 	}
168 	setup_definition(n->d, defn, name);
169 }
170 
171 void
172 macro_pushdef(const char *name, const char *defn)
173 {
174 	ndptr n;
175 	struct macro_definition *d;
176 
177 	n = create_entry(name);
178 	d = xalloc(sizeof(struct macro_definition), NULL);
179 	d->next = n->d;
180 	n->d = d;
181 	setup_definition(n->d, defn, name);
182 }
183 
184 void
185 macro_undefine(const char *name)
186 {
187 	ndptr n = lookup(name);
188 	if (n != NULL) {
189 		struct macro_definition *r, *r2;
190 
191 		for (r = n->d; r != NULL; r = r2) {
192 			r2 = r->next;
193 			if (r->defn != null)
194 				free(r->defn);
195 			free(r);
196 		}
197 		n->d = NULL;
198 	}
199 }
200 
201 void
202 macro_popdef(const char *name)
203 {
204 	ndptr n = lookup(name);
205 
206 	if (n != NULL) {
207 		struct macro_definition *r = n->d;
208 		if (r != NULL) {
209 			n->d = r->next;
210 			if (r->defn != null)
211 				free(r->defn);
212 			free(r);
213 		}
214 	}
215 }
216 
217 void
218 macro_for_all(void (*f)(const char *, struct macro_definition *))
219 {
220 	ndptr n;
221 	unsigned int i;
222 
223 	for (n = ohash_first(&macros, &i); n != NULL;
224 	    n = ohash_next(&macros, &i))
225 		if (n->d != NULL)
226 			f(n->name, n->d);
227 }
228 
229 void
230 setup_builtin(const char *name, unsigned int type)
231 {
232 	ndptr n;
233 	char *name2;
234 
235 	if (prefix_builtins) {
236 		name2 = xalloc(strlen(name)+3+1, NULL);
237 		memcpy(name2, "m4_", 3);
238 		memcpy(name2 + 3, name, strlen(name)+1);
239 	} else
240 		name2 = xstrdup(name);
241 
242 	n = create_entry(name2);
243 	n->builtin_type = type;
244 	n->d = xalloc(sizeof(struct macro_definition), NULL);
245 	n->d->defn = name2;
246 	n->d->type = type;
247 	n->d->next = NULL;
248 }
249 
250 void
251 mark_traced(const char *name, int on)
252 {
253 	ndptr p;
254 	unsigned int i;
255 
256 	if (name == NULL) {
257 		if (on)
258 			trace_flags |= TRACE_ALL;
259 		else
260 			trace_flags &= ~TRACE_ALL;
261 		for (p = ohash_first(&macros, &i); p != NULL;
262 		    p = ohash_next(&macros, &i))
263 			p->trace_flags = FLAG_NO_TRACE;
264 	} else {
265 		p = create_entry(name);
266 		p->trace_flags = on;
267 	}
268 }
269 
270 ndptr
271 macro_getbuiltin(const char *name)
272 {
273 	ndptr p;
274 
275 	p = lookup(name);
276 	if (p == NULL || p->builtin_type == MACRTYPE)
277 		return NULL;
278 	else
279 		return p;
280 }
281 
282 /* XXX things are slightly more complicated than they seem.
283  * a macro may actually be "live" (in the middle of an expansion
284  * on the stack.
285  * So we actually may need to place it in an array for later...
286  */
287 
288 static int kept_capacity = 0;
289 static int kept_size = 0;
290 static char **kept = NULL;
291 
292 static void
293 keep(char *ptr)
294 {
295 	if (kept_capacity <= kept_size) {
296 		if (kept_capacity)
297 			kept_capacity *= 2;
298 		else
299 			kept_capacity = 50;
300 		kept = xreallocarray(kept, kept_capacity,
301 		    sizeof(char *), "Out of memory while saving %d strings\n",
302 		    kept_capacity);
303 	}
304 	kept[kept_size++] = ptr;
305 }
306 
307 static int
308 string_in_use(const char *ptr)
309 {
310 	int i;
311 	for (i = 0; i <= sp; i++) {
312 		if (sstack[i] == STORAGE_MACRO && mstack[i].sstr == ptr)
313 			return 1;
314 		}
315 	return 0;
316 }
317 
318 
319 static void
320 free_definition(char *ptr)
321 {
322 	int i;
323 
324 	/* first try to free old strings */
325 	for (i = 0; i < kept_size; i++) {
326 		if (!string_in_use(kept[i])) {
327 			kept_size--;
328 			free(kept[i]);
329 			if (i != kept_size)
330 				kept[i] = kept[kept_size];
331 			i--;
332 		}
333 	}
334 
335 	/* then deal with us */
336 	if (string_in_use(ptr))
337 		keep(ptr);
338 	else
339 		free(ptr);
340 }
341 
342