xref: /openbsd-src/usr.bin/make/targequiv.c (revision 50b7afb2c2c0993b0894d4e34bf857cb13ed9c80)
1 /*	$OpenBSD: targequiv.c,v 1.5 2014/05/12 19:11:19 espie Exp $ */
2 /*
3  * Copyright (c) 2007-2008 Marc Espie.
4  *
5  * Extensive code changes for the OpenBSD project.
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  *
16  * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
20  * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 
29 /* Compute equivalence tables of targets, helpful for VPATH and parallel
30  * make.
31  */
32 
33 #include <sys/param.h>
34 #include <stddef.h>
35 #include <stdint.h>
36 #include <stdio.h>
37 #include <stdlib.h>
38 #include <string.h>
39 #include <ohash.h>
40 #include "config.h"
41 #include "defines.h"
42 #include "memory.h"
43 #include "gnode.h"
44 #include "lst.h"
45 #include "suff.h"
46 #include "dir.h"
47 #include "targ.h"
48 #include "targequiv.h"
49 
50 struct equiv_list {
51 	GNode *first, *last;
52 	char name[1];
53 };
54 
55 static struct ohash_info equiv_info = {
56 	offsetof(struct equiv_list, name), NULL, hash_calloc, hash_free,
57 	element_alloc
58 };
59 
60 static void attach_node(GNode *, GNode *);
61 static void build_equivalence(void);
62 static void add_to_equiv_list(struct ohash *, GNode *);
63 static char *names_match(GNode *, GNode *);
64 static char *names_match_with_dir(const char *, const char *, char *,
65     char *,  const char *);
66 static char *names_match_with_dirs(const char *, const char *, char *,
67     char *,  const char *, const char *);
68 static char *relative_reduce(const char *, const char *);
69 static char *relative_reduce2(const char *, const char *, const char *);
70 static char *absolute_reduce(const char *);
71 static size_t parse_reduce(size_t, const char *);
72 static void find_siblings(GNode *);
73 
74 /* These functions build `equivalence lists' of targets with the same
75  * basename, as circular lists. They use an intermediate ohash as scaffold,
76  * to insert same-basename targets in a simply linked list. Then they make
77  * those lists circular, to the exception of lone elements, since they can't
78  * alias to anything.
79  *
80  * This structure is used to simplify alias-lookup to a great extent: two
81  * nodes can only alias each other if they're part of the same equivalence
82  * set. Most nodes either don't belong to an alias set, or to a very simple
83  * alias set, thus removing most possibilities.
84  */
85 static void
86 add_to_equiv_list(struct ohash *equiv, GNode *gn)
87 {
88 	const char *end = NULL;
89 	struct equiv_list *e;
90 	unsigned int slot;
91 
92 	if (!should_have_file(gn))
93 		return;
94 
95 	gn->basename = strrchr(gn->name, '/');
96 	if (gn->basename == NULL)
97 		gn->basename = gn->name;
98 	else
99 		gn->basename++;
100 	slot = ohash_qlookupi(equiv, gn->basename, &end);
101 	e = ohash_find(equiv, slot);
102 	if (e == NULL) {
103 		e = ohash_create_entry(&equiv_info, gn->basename, &end);
104 		e->first = NULL;
105 		e->last = gn;
106 		ohash_insert(equiv, slot, e);
107 	}
108 	gn->next = e->first;
109 	e->first = gn;
110 }
111 
112 static void
113 build_equivalence()
114 {
115 	unsigned int i;
116 	GNode *gn;
117 	struct equiv_list *e;
118 	struct ohash equiv;
119 	struct ohash *t = targets_hash();
120 
121 
122 	ohash_init(&equiv, 10, &equiv_info);
123 
124 	for (gn = ohash_first(t, &i); gn != NULL; gn = ohash_next(t, &i))
125 		add_to_equiv_list(&equiv, gn);
126 
127 	/* finish making the lists circular */
128 	for (e = ohash_first(&equiv, &i); e != NULL;
129 	    e = ohash_next(&equiv, &i)) {
130 	    	if (e->last != e->first)
131 			e->last->next = e->first;
132 		free(e);
133 	}
134 	ohash_delete(&equiv);
135 }
136 
137 static const char *curdir, *objdir;
138 static char *kobjdir;
139 static size_t objdir_len;
140 
141 void
142 Targ_setdirs(const char *c, const char *o)
143 {
144 	curdir = c;
145 	objdir = o;
146 
147 	objdir_len = strlen(o);
148 	kobjdir = emalloc(objdir_len+2);
149 	memcpy(kobjdir, o, objdir_len);
150 	kobjdir[objdir_len++] = '/';
151 	kobjdir[objdir_len] = 0;
152 }
153 
154 
155 void
156 kludge_look_harder_for_target(GNode *gn)
157 {
158 	GNode *extra, *cgn;
159 	LstNode ln;
160 
161 	if (strncmp(gn->name, kobjdir, objdir_len) == 0) {
162 		extra = Targ_FindNode(gn->name + objdir_len, TARG_NOCREATE);
163 		if (extra != NULL) {
164 			if (Lst_IsEmpty(&gn->commands))
165 				Lst_Concat(&gn->commands, &extra->commands);
166 			for (ln = Lst_First(&extra->children); ln != NULL;
167 			    ln = Lst_Adv(ln)) {
168 				cgn = (GNode *)Lst_Datum(ln);
169 
170 				if (Lst_AddNew(&gn->children, cgn)) {
171 					Lst_AtEnd(&cgn->parents, gn);
172 					gn->unmade++;
173 				}
174 			}
175 		}
176 	}
177 }
178 
179 static void
180 attach_node(GNode *gn, GNode *extra)
181 {
182 	/* XXX normally extra->sibling == extra, but this is not
183 	 * always the case yet, so we merge the two lists
184 	 */
185 	GNode *tmp;
186 
187 	tmp = gn->sibling;
188 	gn->sibling = extra->sibling;
189 	extra->sibling = tmp;
190 }
191 
192 static char *buffer = NULL;
193 static size_t bufsize = MAXPATHLEN;
194 
195 static size_t
196 parse_reduce(size_t i, const char *src)
197 {
198 	while (src[0] != 0) {
199 		while (src[0] == '/')
200 			src++;
201 		/* special cases */
202 		if (src[0] == '.') {
203 			if (src[1] == '/') {
204 				src += 2;
205 				continue;
206 			}
207 			if (src[1] == '.' && src[2] == '/') {
208 				src += 3;
209 				i--;
210 				while (i > 0 && buffer[i-1] != '/')
211 					i--;
212 				if (i == 0)
213 					i = 1;
214 				continue;
215 			}
216 		}
217 		while (src[0] != '/' && src[0] != 0) {
218 			if (i > bufsize - 2) {
219 				bufsize *= 2;
220 				buffer = erealloc(buffer, bufsize);
221 			}
222 			buffer[i++] = *src++;
223 		}
224 		buffer[i++] = *src;
225 	}
226 	return i;
227 }
228 
229 static char *
230 absolute_reduce(const char *src)
231 {
232 	size_t i = 0;
233 
234 	if (buffer == NULL)
235 		buffer = emalloc(bufsize);
236 
237 	buffer[i++] = '/';
238 	i = parse_reduce(i, src);
239 	return estrdup(buffer);
240 }
241 
242 static char *
243 relative_reduce(const char *dir, const char *src)
244 {
245 	size_t i = 0;
246 
247 	if (buffer == NULL)
248 		buffer = emalloc(bufsize);
249 
250 	buffer[i++] = '/';
251 	i = parse_reduce(i, dir);
252 	i--;
253 
254 	if (buffer[i-1] != '/')
255 		buffer[i++] = '/';
256 	i = parse_reduce(i, src);
257 	return estrdup(buffer);
258 }
259 
260 static char *
261 relative_reduce2(const char *dir1, const char *dir2, const char *src)
262 {
263 	size_t i = 0;
264 
265 	if (buffer == NULL)
266 		buffer = emalloc(bufsize);
267 
268 	buffer[i++] = '/';
269 	i = parse_reduce(i, dir1);
270 	i--;
271 	if (buffer[i-1] != '/')
272 		buffer[i++] = '/';
273 
274 	i = parse_reduce(i, dir2);
275 	i--;
276 	if (buffer[i-1] != '/')
277 		buffer[i++] = '/';
278 
279 	i = parse_reduce(i, src);
280 	return estrdup(buffer);
281 }
282 
283 static char *
284 names_match_with_dir(const char *a, const char *b, char *ra,
285     char *rb,  const char *dir)
286 {
287 	bool r;
288 	bool free_a, free_b;
289 
290 	if (ra == NULL) {
291 		ra = relative_reduce(dir, a);
292 		free_a = true;
293 	} else {
294 		free_a = false;
295 	}
296 
297 	if (rb == NULL) {
298 		rb = relative_reduce(dir, b);
299 		free_b = true;
300 	} else {
301 		free_b = false;
302 	}
303 	r = strcmp(ra, rb) == 0;
304 	if (free_a)
305 		free(ra);
306 	if (r)
307 		return rb;
308 	else {
309 		if (free_b)
310 			free(rb);
311 		return NULL;
312 	}
313 }
314 
315 static char *
316 names_match_with_dirs(const char *a, const char *b, char *ra,
317     char *rb,  const char *dir1, const char *dir2)
318 {
319 	bool r;
320 	bool free_a, free_b;
321 
322 	if (ra == NULL) {
323 		ra = relative_reduce2(dir1, dir2, a);
324 		free_a = true;
325 	} else {
326 		free_a = false;
327 	}
328 
329 	if (rb == NULL) {
330 		rb = relative_reduce2(dir1, dir2, b);
331 		free_b = true;
332 	} else {
333 		free_b = false;
334 	}
335 	r = strcmp(ra, rb) == 0;
336 	if (free_a)
337 		free(ra);
338 	if (r)
339 		return rb;
340 	else {
341 		if (free_b)
342 			free(rb);
343 		return NULL;
344 	}
345 }
346 
347 static char *
348 names_match(GNode *a, GNode *b)
349 {
350 	char *ra = NULL , *rb = NULL;
351 	char *r;
352 
353 	if (a->name[0] == '/')
354 		ra = absolute_reduce(a->name);
355 	if (b->name[0] == '/')
356 		rb = absolute_reduce(b->name);
357 	if (ra && rb) {
358 		if (strcmp(ra, rb) == 0)
359 			r = rb;
360 		else
361 			r = NULL;
362 	} else {
363 		r = names_match_with_dir(a->name, b->name, ra, rb, objdir);
364 		if (!r)
365 			r = names_match_with_dir(a->name, b->name, ra, rb,
366 			    curdir);
367 		if (!r) {
368 			/* b has necessarily the same one */
369 			Lst l = find_suffix_path(a);
370 			LstNode ln;
371 
372 			for (ln = Lst_First(l); ln != NULL; ln = Lst_Adv(ln)) {
373 				const char *p = PathEntry_name(Lst_Datum(ln));
374 				if (p[0] == '/') {
375 					r = names_match_with_dir(a->name,
376 					    b->name, ra, rb, p);
377 					if (r)
378 						break;
379 				} else {
380 					r = names_match_with_dirs(a->name,
381 					    b->name, ra, rb, p, objdir);
382 					if (r)
383 						break;
384 					r = names_match_with_dirs(a->name,
385 					    b->name, ra, rb, p, curdir);
386 					if (r)
387 						break;
388 				}
389 			}
390 		}
391 	}
392 	free(ra);
393 	if (r != rb)
394 		free(rb);
395 	return r;
396 }
397 
398 static void
399 find_siblings(GNode *gn)
400 {
401 	GNode *gn2;
402 	char *fullpath;
403 
404 	/* not part of an equivalence class: can't alias */
405 	if (gn->next == NULL)
406 		return;
407 	/* already resolved, actually */
408 	if (gn->sibling != gn)
409 		return;
410 	if (DEBUG(NAME_MATCHING))
411 		fprintf(stderr, "Matching for %s:", gn->name);
412 	/* look through the aliases */
413 	for (gn2 = gn->next; gn2 != gn; gn2 = gn2->next) {
414 		fullpath = names_match(gn, gn2);
415 		if (fullpath) {
416 			attach_node(gn, gn2);
417 		} else {
418 			if (DEBUG(NAME_MATCHING))
419 				fputc('!', stderr);
420 		}
421 		if (DEBUG(NAME_MATCHING))
422 			fprintf(stderr, "%s ", gn2->name);
423 	}
424 	if (DEBUG(NAME_MATCHING))
425 		fputc('\n', stderr);
426 }
427 
428 void
429 look_harder_for_target(GNode *gn)
430 {
431 	static bool equiv_was_built = false;
432 
433 	if (!equiv_was_built) {
434 		build_equivalence();
435 		equiv_was_built = true;
436 	}
437 
438 	if (gn->type & (OP_RESOLVED | OP_PHONY))
439 		return;
440 	gn->type |= OP_RESOLVED;
441 	find_siblings(gn);
442 }
443 
444 bool
445 is_sibling(GNode *gn, GNode *gn2)
446 {
447 	GNode *sibling;
448 
449 	sibling = gn;
450 	do {
451 		if (sibling == gn2)
452 			return true;
453 		sibling = sibling->sibling;
454 	} while (sibling != gn);
455 
456 	return false;
457 }
458