1 /* Implementation of pattern-matching file search paths for GNU Make.
2 Copyright (C) 1988-2022 Free Software Foundation, Inc.
3 This file is part of GNU Make.
4
5 GNU Make is free software; you can redistribute it and/or modify it under the
6 terms of the GNU General Public License as published by the Free Software
7 Foundation; either version 3 of the License, or (at your option) any later
8 version.
9
10 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
11 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
12 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License along with
15 this program. If not, see <https://www.gnu.org/licenses/>. */
16
17 #include "makeint.h"
18 #include "filedef.h"
19 #include "variable.h"
20 #ifdef WINDOWS32
21 #include "pathstuff.h"
22 #endif
23
24
25 /* Structure used to represent a selective VPATH searchpath. */
26
27 struct vpath
28 {
29 struct vpath *next; /* Pointer to next struct in the linked list. */
30 const char *pattern; /* The pattern to match. */
31 const char *percent; /* Pointer into 'pattern' where the '%' is. */
32 size_t patlen; /* Length of the pattern. */
33 const char **searchpath; /* Null-terminated list of directories. */
34 size_t maxlen; /* Maximum length of any entry in the list. */
35 };
36
37 /* Linked-list of all selective VPATHs. */
38
39 static struct vpath *vpaths;
40
41 /* Structure for the general VPATH given in the variable. */
42
43 static struct vpath *general_vpath;
44
45 /* Structure for GPATH given in the variable. */
46
47 static struct vpath *gpaths;
48
49
50 /* Reverse the chain of selective VPATH lists so they will be searched in the
51 order given in the makefiles and construct the list from the VPATH
52 variable. */
53
54 void
55 build_vpath_lists (void)
56 {
57 struct vpath *new = 0;
58 struct vpath *old, *nexto;
59 char *p;
60
61 /* Reverse the chain. */
62 for (old = vpaths; old != 0; old = nexto)
63 {
64 nexto = old->next;
65 old->next = new;
66 new = old;
67 }
68
69 vpaths = new;
70
71 /* If there is a VPATH variable with a nonnull value, construct the
72 general VPATH list from it. We use variable_expand rather than just
73 calling lookup_variable so that it will be recursively expanded. */
74
75 {
76 /* Turn off --warn-undefined-variables while we expand SHELL and IFS. */
77 int save = warn_undefined_variables_flag;
78 warn_undefined_variables_flag = 0;
79
80 p = variable_expand ("$(strip $(VPATH))");
81
82 warn_undefined_variables_flag = save;
83 }
84
85 if (*p != '\0')
86 {
87 /* Save the list of vpaths. */
88 struct vpath *save_vpaths = vpaths;
89 char gp[] = "%";
90
91 /* Empty 'vpaths' so the new one will have no next, and 'vpaths'
92 will still be nil if P contains no existing directories. */
93 vpaths = 0;
94
95 /* Parse P. */
96 construct_vpath_list (gp, p);
97
98 /* Store the created path as the general path,
99 and restore the old list of vpaths. */
100 general_vpath = vpaths;
101 vpaths = save_vpaths;
102 }
103
104 /* If there is a GPATH variable with a nonnull value, construct the
105 GPATH list from it. We use variable_expand rather than just
106 calling lookup_variable so that it will be recursively expanded. */
107
108 {
109 /* Turn off --warn-undefined-variables while we expand SHELL and IFS. */
110 int save = warn_undefined_variables_flag;
111 warn_undefined_variables_flag = 0;
112
113 p = variable_expand ("$(strip $(GPATH))");
114
115 warn_undefined_variables_flag = save;
116 }
117
118 if (*p != '\0')
119 {
120 /* Save the list of vpaths. */
121 struct vpath *save_vpaths = vpaths;
122 char gp[] = "%";
123
124 /* Empty 'vpaths' so the new one will have no next, and 'vpaths'
125 will still be nil if P contains no existing directories. */
126 vpaths = 0;
127
128 /* Parse P. */
129 construct_vpath_list (gp, p);
130
131 /* Store the created path as the GPATH,
132 and restore the old list of vpaths. */
133 gpaths = vpaths;
134 vpaths = save_vpaths;
135 }
136 }
137
138 /* Construct the VPATH listing for the PATTERN and DIRPATH given.
139
140 This function is called to generate selective VPATH lists and also for
141 the general VPATH list (which is in fact just a selective VPATH that
142 is applied to everything). The returned pointer is either put in the
143 linked list of all selective VPATH lists or in the GENERAL_VPATH
144 variable.
145
146 If DIRPATH is nil, remove all previous listings with the same
147 pattern. If PATTERN is nil, remove all VPATH listings. Existing
148 and readable directories that are not "." given in the DIRPATH
149 separated by the path element separator (defined in makeint.h) are
150 loaded into the directory hash table if they are not there already
151 and put in the VPATH searchpath for the given pattern with trailing
152 slashes stripped off if present (and if the directory is not the
153 root, "/"). The length of the longest entry in the list is put in
154 the structure as well. The new entry will be at the head of the
155 VPATHS chain. */
156
157 void
158 construct_vpath_list (char *pattern, char *dirpath)
159 {
160 unsigned int elem;
161 char *p;
162 const char **vpath;
163 size_t maxvpath;
164 unsigned int maxelem;
165 const char *percent = NULL;
166
167 if (pattern != 0)
168 percent = find_percent (pattern);
169
170 if (dirpath == 0)
171 {
172 /* Remove matching listings. */
173 struct vpath *path, *lastpath;
174
175 lastpath = 0;
176 path = vpaths;
177 while (path != 0)
178 {
179 struct vpath *next = path->next;
180
181 if (pattern == 0
182 || (((percent == 0 && path->percent == 0)
183 || (percent - pattern == path->percent - path->pattern))
184 && streq (pattern, path->pattern)))
185 {
186 /* Remove it from the linked list. */
187 if (lastpath == 0)
188 vpaths = path->next;
189 else
190 lastpath->next = next;
191
192 /* Free its unused storage. */
193 /* MSVC erroneously warns without a cast here. */
194 free ((void *)path->searchpath);
195 free (path);
196 }
197 else
198 lastpath = path;
199
200 path = next;
201 }
202
203 return;
204 }
205
206 #ifdef WINDOWS32
207 convert_vpath_to_windows32 (dirpath, ';');
208 #endif
209
210 /* Skip over any initial separators and blanks. */
211 while (STOP_SET (*dirpath, MAP_BLANK|MAP_PATHSEP))
212 ++dirpath;
213
214 /* Figure out the maximum number of VPATH entries and put it in
215 MAXELEM. We start with 2, one before the first separator and one
216 nil (the list terminator) and increment our estimated number for
217 each separator or blank we find. */
218 maxelem = 2;
219 p = dirpath;
220 while (*p != '\0')
221 if (STOP_SET (*p++, MAP_BLANK|MAP_PATHSEP))
222 ++maxelem;
223
224 vpath = xmalloc (maxelem * sizeof (const char *));
225 maxvpath = 0;
226
227 elem = 0;
228 p = dirpath;
229 while (*p != '\0')
230 {
231 char *v;
232 size_t len;
233
234 /* Find the end of this entry. */
235 v = p;
236 while (*p != '\0'
237 #if defined(HAVE_DOS_PATHS) && (PATH_SEPARATOR_CHAR == ':')
238 /* Platforms whose PATH_SEPARATOR_CHAR is ':' and which
239 also define HAVE_DOS_PATHS would like us to recognize
240 colons after the drive letter in the likes of
241 "D:/foo/bar:C:/xyzzy". */
242 && (*p != PATH_SEPARATOR_CHAR || (p == v + 1 && ISDIRSEP (p[1])))
243 #else
244 && *p != PATH_SEPARATOR_CHAR
245 #endif
246 && !ISBLANK (*p))
247 ++p;
248
249 len = p - v;
250 /* Make sure there's no trailing slash,
251 but still allow "/" as a directory. */
252 #if defined(__MSDOS__) || defined(__EMX__) || defined(HAVE_DOS_PATHS)
253 /* We need also to leave alone a trailing slash in "d:/". */
254 if (len > 3 || (len > 1 && v[1] != ':'))
255 #endif
256 if (len > 1 && p[-1] == '/')
257 --len;
258
259 /* Put the directory on the vpath list. */
260 if (len > 1 || *v != '.')
261 {
262 vpath[elem++] = dir_name (strcache_add_len (v, len));
263 if (len > maxvpath)
264 maxvpath = len;
265 }
266
267 /* Skip over separators and blanks between entries. */
268 while (STOP_SET (*p, MAP_BLANK|MAP_PATHSEP))
269 ++p;
270 }
271
272 if (elem > 0)
273 {
274 struct vpath *path;
275 /* ELEM is now incremented one element past the last
276 entry, to where the nil-pointer terminator goes.
277 Usually this is maxelem - 1. If not, shrink down. */
278 if (elem < (maxelem - 1))
279 vpath = xrealloc ((void *)vpath, (elem+1) * sizeof (const char *));
280
281 /* Put the nil-pointer terminator on the end of the VPATH list. */
282 vpath[elem] = NULL;
283
284 /* Construct the vpath structure and put it into the linked list. */
285 path = xmalloc (sizeof (struct vpath));
286 path->searchpath = vpath;
287 path->maxlen = maxvpath;
288 path->next = vpaths;
289 vpaths = path;
290
291 /* Set up the members. */
292 path->pattern = strcache_add (pattern);
293 path->patlen = strlen (pattern);
294 path->percent = percent ? path->pattern + (percent - pattern) : 0;
295 }
296 else
297 /* There were no entries, so free whatever space we allocated. */
298 /* MSVC erroneously warns without a cast here. */
299 free ((void *)vpath);
300 }
301
302 /* Search the GPATH list for a pathname string that matches the one passed
303 in. If it is found, return 1. Otherwise we return 0. */
304
305 int
306 gpath_search (const char *file, size_t len)
307 {
308 if (gpaths && (len <= gpaths->maxlen))
309 {
310 const char **gp;
311 for (gp = gpaths->searchpath; *gp != NULL; ++gp)
312 if (strneq (*gp, file, len) && (*gp)[len] == '\0')
313 return 1;
314 }
315
316 return 0;
317 }
318
319
320 /* Search the given VPATH list for a directory where the name pointed to by
321 FILE exists. If it is found, we return a cached name of the existing file
322 and set *MTIME_PTR (if MTIME_PTR is not NULL) to its modtime (or zero if no
323 stat call was done). Also set the matching directory index in PATH_INDEX
324 if it is not NULL. Otherwise we return NULL. */
325
326 static const char *
327 selective_vpath_search (struct vpath *path, const char *file,
328 FILE_TIMESTAMP *mtime_ptr, unsigned int* path_index)
329 {
330 int not_target;
331 char *name;
332 const char *n;
333 const char *filename;
334 const char **vpath = path->searchpath;
335 size_t maxvpath = path->maxlen;
336 unsigned int i;
337 size_t flen, name_dplen;
338 int exists = 0;
339
340 /* Find out if *FILE is a target.
341 If and only if it is NOT a target, we will accept prospective
342 files that don't exist but are mentioned in a makefile. */
343 {
344 struct file *f = lookup_file (file);
345 not_target = f == 0 || !f->is_target;
346 }
347
348 flen = strlen (file);
349
350 /* Split *FILE into a directory prefix and a name-within-directory.
351 NAME_DPLEN gets the length of the prefix; FILENAME gets the pointer to
352 the name-within-directory and FLEN is its length. */
353
354 n = strrchr (file, '/');
355 #ifdef HAVE_DOS_PATHS
356 /* We need the rightmost slash or backslash. */
357 {
358 const char *bslash = strrchr (file, '\\');
359 if (!n || bslash > n)
360 n = bslash;
361 }
362 #endif
363 name_dplen = n != 0 ? n - file : 0;
364 filename = name_dplen > 0 ? n + 1 : file;
365 if (name_dplen > 0)
366 flen -= name_dplen + 1;
367
368 /* Get enough space for the biggest VPATH entry, a slash, the directory
369 prefix that came with FILE, another slash (although this one may not
370 always be necessary), the filename, and a null terminator. */
371 name = alloca (maxvpath + 1 + name_dplen + 1 + flen + 1);
372
373 /* Try each VPATH entry. */
374 for (i = 0; vpath[i] != 0; ++i)
375 {
376 int exists_in_cache = 0;
377 char *p = name;
378 size_t vlen = strlen (vpath[i]);
379
380 /* Put the next VPATH entry into NAME at P and increment P past it. */
381 p = mempcpy (p, vpath[i], vlen);
382
383 /* Add the directory prefix already in *FILE. */
384 if (name_dplen > 0)
385 {
386 #ifndef VMS
387 *p++ = '/';
388 #else
389 /* VMS: if this is not in VMS format, treat as Unix format */
390 if ((*p != ':') && (*p != ']') && (*p != '>'))
391 *p++ = '/';
392 #endif
393 p = mempcpy (p, file, name_dplen);
394 }
395
396 #ifdef HAVE_DOS_PATHS
397 /* Cause the next if to treat backslash and slash alike. */
398 if (p != name && p[-1] == '\\' )
399 p[-1] = '/';
400 #endif
401 /* Now add the name-within-directory at the end of NAME. */
402 #ifndef VMS
403 if (p != name && p[-1] != '/')
404 {
405 *p = '/';
406 memcpy (p + 1, filename, flen + 1);
407 }
408 else
409 #else
410 /* VMS use a slash if no directory terminator present */
411 if (p != name && p[-1] != '/' && p[-1] != ':' &&
412 p[-1] != '>' && p[-1] != ']')
413 {
414 *p = '/';
415 memcpy (p + 1, filename, flen + 1);
416 }
417 else
418 #endif
419 memcpy (p, filename, flen + 1);
420
421 /* Check if the file is mentioned in a makefile. If *FILE is not
422 a target, that is enough for us to decide this file exists.
423 If *FILE is a target, then the file must be mentioned in the
424 makefile also as a target to be chosen.
425
426 The restriction that *FILE must not be a target for a
427 makefile-mentioned file to be chosen was added by an
428 inadequately commented change in July 1990; I am not sure off
429 hand what problem it fixes.
430
431 In December 1993 I loosened this restriction to allow a file
432 to be chosen if it is mentioned as a target in a makefile. This
433 seem logical.
434
435 Special handling for -W / -o: make sure we preserve the special
436 values here. Actually this whole thing is a little bogus: I think
437 we should ditch the name/hname thing and look into the renamed
438 capability that already exists for files: that is, have a new struct
439 file* entry for the VPATH-found file, and set the renamed field if
440 we use it.
441 */
442 {
443 struct file *f = lookup_file (name);
444 if (f != 0)
445 {
446 exists = not_target || f->is_target;
447 if (exists && mtime_ptr
448 && (f->last_mtime == OLD_MTIME || f->last_mtime == NEW_MTIME))
449 {
450 *mtime_ptr = f->last_mtime;
451 mtime_ptr = 0;
452 }
453 }
454 }
455
456 if (!exists)
457 {
458 /* That file wasn't mentioned in the makefile.
459 See if it actually exists. */
460
461 #ifdef VMS
462 /* For VMS syntax just use the original vpath */
463 if (*p != '/')
464 exists_in_cache = exists = dir_file_exists_p (vpath[i], filename);
465 else
466 #endif
467 {
468 /* Clobber a null into the name at the last slash.
469 Now NAME is the name of the directory to look in. */
470 *p = '\0';
471 /* We know the directory is in the hash table now because either
472 construct_vpath_list or the code just above put it there.
473 Does the file we seek exist in it? */
474 exists_in_cache = exists = dir_file_exists_p (name, filename);
475 }
476 }
477
478 if (exists)
479 {
480 /* The file is in the directory cache.
481 Now check that it actually exists in the filesystem.
482 The cache may be out of date. When vpath thinks a file
483 exists, but stat fails for it, confusion results in the
484 higher levels. */
485
486 struct stat st;
487
488 #ifndef VMS
489 /* Put the slash back in NAME. */
490 *p = '/';
491 #else
492 /* If the slash was removed, put it back */
493 if (*p == 0)
494 *p = '/';
495 #endif
496
497 if (exists_in_cache) /* Makefile-mentioned file need not exist. */
498 {
499 int e;
500
501 EINTRLOOP (e, stat (name, &st)); /* Does it really exist? */
502 if (e != 0)
503 {
504 exists = 0;
505 continue;
506 }
507
508 /* Store the modtime into *MTIME_PTR for the caller. */
509 if (mtime_ptr != 0)
510 {
511 *mtime_ptr = FILE_TIMESTAMP_STAT_MODTIME (name, st);
512 mtime_ptr = 0;
513 }
514 }
515
516 /* We have found a file.
517 If we get here and mtime_ptr hasn't been set, record
518 UNKNOWN_MTIME to indicate this. */
519 if (mtime_ptr != 0)
520 *mtime_ptr = UNKNOWN_MTIME;
521
522 /* Store the name we found and return it. */
523
524 if (path_index)
525 *path_index = i;
526
527 return strcache_add_len (name, (p + 1 - name) + flen);
528 }
529 }
530
531 return 0;
532 }
533
534
535 /* Search the VPATH list whose pattern matches FILE for a directory where FILE
536 exists. If it is found, return the cached name of an existing file, and
537 set *MTIME_PTR (if MTIME_PTR is not NULL) to its modtime (or zero if no
538 stat call was done). Also set the matching directory index in VPATH_INDEX
539 and PATH_INDEX if they are not NULL. Otherwise we return 0. */
540
541 const char *
542 vpath_search (const char *file, FILE_TIMESTAMP *mtime_ptr,
543 unsigned int* vpath_index, unsigned int* path_index)
544 {
545 struct vpath *v;
546
547 /* If there are no VPATH entries or FILENAME starts at the root,
548 there is nothing we can do. */
549
550 if (file[0] == '/'
551 #ifdef HAVE_DOS_PATHS
552 || file[0] == '\\' || file[1] == ':'
553 #endif
554 || (vpaths == 0 && general_vpath == 0))
555 return 0;
556
557 if (vpath_index)
558 {
559 *vpath_index = 0;
560 *path_index = 0;
561 }
562
563 for (v = vpaths; v != 0; v = v->next)
564 {
565 if (pattern_matches (v->pattern, v->percent, file))
566 {
567 const char *p = selective_vpath_search (
568 v, file, mtime_ptr, path_index);
569 if (p)
570 return p;
571 }
572
573 if (vpath_index)
574 ++*vpath_index;
575 }
576
577
578 if (general_vpath != 0)
579 {
580 const char *p = selective_vpath_search (
581 general_vpath, file, mtime_ptr, path_index);
582 if (p)
583 return p;
584 }
585
586 return 0;
587 }
588
589
590
591
592 /* Print the data base of VPATH search paths. */
593
594 void
595 print_vpath_data_base (void)
596 {
597 unsigned int nvpaths;
598 struct vpath *v;
599
600 puts (_("\n# VPATH Search Paths\n"));
601
602 nvpaths = 0;
603 for (v = vpaths; v != 0; v = v->next)
604 {
605 unsigned int i;
606
607 ++nvpaths;
608
609 printf ("vpath %s ", v->pattern);
610
611 for (i = 0; v->searchpath[i] != 0; ++i)
612 printf ("%s%c", v->searchpath[i],
613 v->searchpath[i + 1] == 0 ? '\n' : PATH_SEPARATOR_CHAR);
614 }
615
616 if (vpaths == 0)
617 puts (_("# No 'vpath' search paths."));
618 else
619 printf (_("\n# %u 'vpath' search paths.\n"), nvpaths);
620
621 if (general_vpath == 0)
622 puts (_("\n# No general ('VPATH' variable) search path."));
623 else
624 {
625 const char **path = general_vpath->searchpath;
626 unsigned int i;
627
628 fputs (_("\n# General ('VPATH' variable) search path:\n# "), stdout);
629
630 for (i = 0; path[i] != 0; ++i)
631 printf ("%s%c", path[i],
632 path[i + 1] == 0 ? '\n' : PATH_SEPARATOR_CHAR);
633 }
634 }