xref: /freebsd/usr.bin/m4/look.c (revision 193d9e768ba63fcfb187cfd17f461f7d41345048) 
1 /*	$OpenBSD: look.c,v 1.24 2014/12/21 09:33:12 espie Exp $	*/
2 
3 /*
4  * Copyright (c) 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Ozan Yigit at York University.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  */
34 #include <sys/cdefs.h>
35 __FBSDID("$FreeBSD$");
36 
37 /*
38  * look.c
39  * Facility: m4 macro processor
40  * by: oz
41  */
42 
43 #include <sys/types.h>
44 #include <stdio.h>
45 #include <stdlib.h>
46 #include <stdint.h>
47 #include <stddef.h>
48 #include <string.h>
49 #include <ohash.h>
50 #include "mdef.h"
51 #include "stdd.h"
52 #include "extern.h"
53 
54 static void *hash_calloc(size_t, size_t, void *);
55 static void hash_free(void *, void *);
56 static void *element_alloc(size_t, void *);
57 static void setup_definition(struct macro_definition *, const char *,
58     const char *);
59 static void free_definition(char *);
60 static void keep(char *);
61 static int string_in_use(const char *);
62 
63 static struct ohash_info macro_info = {
64 	offsetof(struct ndblock, name),
65 	NULL, hash_calloc, hash_free, element_alloc };
66 
67 struct ohash macros;
68 
69 /* Support routines for hash tables.  */
70 void *
71 hash_calloc(size_t n, size_t s, void *u __unused)
72 {
73 	void *storage = xcalloc(n, s, "hash alloc");
74 	return storage;
75 }
76 
77 void
78 hash_free(void *p, void *u __unused)
79 {
80 	free(p);
81 }
82 
83 void *
84 element_alloc(size_t s, void *u __unused)
85 {
86 	return xalloc(s, "element alloc");
87 }
88 
89 void
90 init_macros(void)
91 {
92 	ohash_init(&macros, 10, &macro_info);
93 }
94 
95 /*
96  * find name in the hash table
97  */
98 ndptr
99 lookup(const char *name)
100 {
101 	return ohash_find(&macros, ohash_qlookup(&macros, name));
102 }
103 
104 struct macro_definition *
105 lookup_macro_definition(const char *name)
106 {
107 	ndptr p;
108 
109 	p = ohash_find(&macros, ohash_qlookup(&macros, name));
110 	if (p)
111 		return p->d;
112 	else
113 		return NULL;
114 }
115 
116 static void
117 setup_definition(struct macro_definition *d, const char *defn, const char *name)
118 {
119 	ndptr p;
120 
121 	if (strncmp(defn, BUILTIN_MARKER, sizeof(BUILTIN_MARKER)-1) == 0 &&
122 	    (p = macro_getbuiltin(defn+sizeof(BUILTIN_MARKER)-1)) != NULL) {
123 		d->type = macro_builtin_type(p);
124 		d->defn = xstrdup(defn+sizeof(BUILTIN_MARKER)-1);
125 	} else {
126 		if (!*defn)
127 			d->defn = __DECONST(char *, null);
128 		else
129 			d->defn = xstrdup(defn);
130 		d->type = MACRTYPE;
131 	}
132 	if (STREQ(name, defn))
133 		d->type |= RECDEF;
134 }
135 
136 static ndptr
137 create_entry(const char *name)
138 {
139 	const char *end = NULL;
140 	unsigned int i;
141 	ndptr n;
142 
143 	i = ohash_qlookupi(&macros, name, &end);
144 	n = ohash_find(&macros, i);
145 	if (n == NULL) {
146 		n = ohash_create_entry(&macro_info, name, &end);
147 		ohash_insert(&macros, i, n);
148 		n->trace_flags = FLAG_NO_TRACE;
149 		n->builtin_type = MACRTYPE;
150 		n->d = NULL;
151 	}
152 	return n;
153 }
154 
155 void
156 macro_define(const char *name, const char *defn)
157 {
158 	ndptr n = create_entry(name);
159 	if (n->d != NULL) {
160 		if (n->d->defn != null)
161 			free_definition(n->d->defn);
162 	} else {
163 		n->d = xalloc(sizeof(struct macro_definition), NULL);
164 		n->d->next = NULL;
165 	}
166 	setup_definition(n->d, defn, name);
167 }
168 
169 void
170 macro_pushdef(const char *name, const char *defn)
171 {
172 	ndptr n;
173 	struct macro_definition *d;
174 
175 	n = create_entry(name);
176 	d = xalloc(sizeof(struct macro_definition), NULL);
177 	d->next = n->d;
178 	n->d = d;
179 	setup_definition(n->d, defn, name);
180 }
181 
182 void
183 macro_undefine(const char *name)
184 {
185 	ndptr n = lookup(name);
186 	if (n != NULL) {
187 		struct macro_definition *r, *r2;
188 
189 		for (r = n->d; r != NULL; r = r2) {
190 			r2 = r->next;
191 			if (r->defn != null)
192 				free(r->defn);
193 			free(r);
194 		}
195 		n->d = NULL;
196 	}
197 }
198 
199 void
200 macro_popdef(const char *name)
201 {
202 	ndptr n = lookup(name);
203 
204 	if (n != NULL) {
205 		struct macro_definition *r = n->d;
206 		if (r != NULL) {
207 			n->d = r->next;
208 			if (r->defn != null)
209 				free(r->defn);
210 			free(r);
211 		}
212 	}
213 }
214 
215 void
216 macro_for_all(void (*f)(const char *, struct macro_definition *))
217 {
218 	ndptr n;
219 	unsigned int i;
220 
221 	for (n = ohash_first(&macros, &i); n != NULL;
222 	    n = ohash_next(&macros, &i))
223 		if (n->d != NULL)
224 			f(n->name, n->d);
225 }
226 
227 void
228 setup_builtin(const char *name, unsigned int type)
229 {
230 	ndptr n;
231 	char *name2;
232 
233 	if (prefix_builtins) {
234 		name2 = xalloc(strlen(name)+3+1, NULL);
235 		memcpy(name2, "m4_", 3);
236 		memcpy(name2 + 3, name, strlen(name)+1);
237 	} else
238 		name2 = xstrdup(name);
239 
240 	n = create_entry(name2);
241 	n->builtin_type = type;
242 	n->d = xalloc(sizeof(struct macro_definition), NULL);
243 	n->d->defn = name2;
244 	n->d->type = type;
245 	n->d->next = NULL;
246 }
247 
248 void
249 mark_traced(const char *name, int on)
250 {
251 	ndptr p;
252 	unsigned int i;
253 
254 	if (name == NULL) {
255 		if (on)
256 			trace_flags |= TRACE_ALL;
257 		else
258 			trace_flags &= ~TRACE_ALL;
259 		for (p = ohash_first(&macros, &i); p != NULL;
260 		    p = ohash_next(&macros, &i))
261 			p->trace_flags = FLAG_NO_TRACE;
262 	} else {
263 		p = create_entry(name);
264 		p->trace_flags = on;
265 	}
266 }
267 
268 ndptr
269 macro_getbuiltin(const char *name)
270 {
271 	ndptr p;
272 
273 	p = lookup(name);
274 	if (p == NULL || p->builtin_type == MACRTYPE)
275 		return NULL;
276 	else
277 		return p;
278 }
279 
280 /* XXX things are slightly more complicated than they seem.
281  * a macro may actually be "live" (in the middle of an expansion
282  * on the stack.
283  * So we actually may need to place it in an array for later...
284  */
285 
286 static int kept_capacity = 0;
287 static int kept_size = 0;
288 static char **kept = NULL;
289 
290 static void
291 keep(char *ptr)
292 {
293 	if (kept_capacity <= kept_size) {
294 		if (kept_capacity)
295 			kept_capacity *= 2;
296 		else
297 			kept_capacity = 50;
298 		kept = xreallocarray(kept, kept_capacity,
299 		    sizeof(char *), "Out of memory while saving %d strings\n",
300 		    kept_capacity);
301 	}
302 	kept[kept_size++] = ptr;
303 }
304 
305 static int
306 string_in_use(const char *ptr)
307 {
308 	int i;
309 	for (i = 0; i <= sp; i++) {
310 		if (sstack[i] == STORAGE_MACRO && mstack[i].sstr == ptr)
311 			return 1;
312 		}
313 	return 0;
314 }
315 
316 
317 static void
318 free_definition(char *ptr)
319 {
320 	int i;
321 
322 	/* first try to free old strings */
323 	for (i = 0; i < kept_size; i++) {
324 		if (!string_in_use(kept[i])) {
325 			kept_size--;
326 			free(kept[i]);
327 			if (i != kept_size)
328 				kept[i] = kept[kept_size];
329 			i--;
330 		}
331 	}
332 
333 	/* then deal with us */
334 	if (string_in_use(ptr))
335 		keep(ptr);
336 	else
337 		free(ptr);
338 }
339 
340