1 /* Implicit rule searching for GNU Make.
2 Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997,
3 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009,
4 2010 Free Software Foundation, Inc.
5 This file is part of GNU Make.
7 GNU Make is free software; you can redistribute it and/or modify it under the
8 terms of the GNU General Public License as published by the Free Software
9 Foundation; either version 3 of the License, or (at your option) any later
12 GNU Make is distributed in the hope that it will be useful, but WITHOUT ANY
13 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR
14 A PARTICULAR PURPOSE. See the GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License along with
17 this program. If not, see <http://www.gnu.org/licenses/>. */
25 #include "job.h" /* struct child, used inside commands.h */
26 #include "commands.h" /* set_file_variables */
28 static int pattern_search (struct file
*file
, int archive
,
29 unsigned int depth
, unsigned int recursions
);
31 /* For a FILE which has no commands specified, try to figure out some
32 from the implicit pattern rules.
33 Returns 1 if a suitable implicit rule was found,
34 after modifying FILE to contain the appropriate commands and deps,
35 or returns 0 if no implicit rule was found. */
38 try_implicit_rule (struct file
*file
, unsigned int depth
)
40 DBF (DB_IMPLICIT
, _("Looking for an implicit rule for `%s'.\n"));
42 /* The order of these searches was previously reversed. My logic now is
43 that since the non-archive search uses more information in the target
44 (the archive search omits the archive name), it is more specific and
47 if (pattern_search (file
, 0, depth
, 0))
51 /* If this is an archive member reference, use just the
52 archive member name to search for implicit rules. */
53 if (ar_name (file
->name
))
56 _("Looking for archive-member implicit rule for `%s'.\n"));
57 if (pattern_search (file
, 1, depth
, 0))
66 /* Scans the BUFFER for the next word with whitespace as a separator.
67 Returns the pointer to the beginning of the word. LENGTH hold the
68 length of the word. */
71 get_next_word (const char *buffer
, unsigned int *length
)
73 const char *p
= buffer
, *beg
;
76 /* Skip any leading whitespace. */
77 while (isblank ((unsigned char)*p
))
87 /* We already found the first value of "c", above. */
105 /* This is a variable reference, so read it to the matching
113 /* This is a single-letter variable reference. */
116 for (count
= 0; *p
!= '\0'; ++p
)
120 else if (*p
== closeparen
&& --count
< 0)
147 /* This structure stores information about the expanded prerequisites for a
148 pattern rule. NAME is always set to the strcache'd name of the prereq.
149 FILE and PATTERN will be set for intermediate files only. IGNORE_MTIME is
150 copied from the prerequisite we expanded.
157 unsigned int ignore_mtime
: 1;
160 /* This structure stores information about pattern rules that we need
167 /* Index of the target in this rule that matched the file. */
168 unsigned int matches
;
170 /* Stem length for this match. */
171 unsigned int stemlen
;
173 /* Definition order of this rule. Used to implement stable sort.*/
176 /* Nonzero if the LASTSLASH logic was used in matching this rule. */
177 char checked_lastslash
;
181 stemlen_compare (const void *v1
, const void *v2
)
183 const struct tryrule
*r1
= v1
;
184 const struct tryrule
*r2
= v2
;
185 int r
= r1
->stemlen
- r2
->stemlen
;
186 return r
!= 0 ? r
: (int)(r1
->order
- r2
->order
);
189 /* Search the pattern rules for a rule with an existing dependency to make
190 FILE. If a rule is found, the appropriate commands and deps are put in FILE
191 and 1 is returned. If not, 0 is returned.
193 If ARCHIVE is nonzero, FILE->name is of the form "LIB(MEMBER)". A rule for
194 "(MEMBER)" will be searched for, and "(MEMBER)" will not be chopped up into
195 directory and filename parts.
197 If an intermediate file is found by pattern search, the intermediate file
198 is set up as a target by the recursive call and is also made a dependency
201 DEPTH is used for debugging messages. */
204 pattern_search (struct file
*file
, int archive
,
205 unsigned int depth
, unsigned int recursions
)
207 /* Filename we are searching for a rule for. */
208 const char *filename
= archive
? strchr (file
->name
, '(') : file
->name
;
210 /* Length of FILENAME. */
211 unsigned int namelen
= strlen (filename
);
213 /* The last slash in FILENAME (or nil if there is none). */
214 const char *lastslash
;
216 /* This is a file-object used as an argument in
217 recursive calls. It never contains any data
218 except during a recursive call. */
219 struct file
*int_file
= 0;
221 /* List of dependencies found recursively. */
222 struct patdeps
*deplist
223 = xmalloc (max_pattern_deps
* sizeof (struct patdeps
));
224 struct patdeps
*pat
= deplist
;
226 /* All the prerequisites actually found for a rule, after expansion. */
229 /* Names of possible dependencies are constructed in this buffer. */
230 char *depname
= alloca (namelen
+ max_pattern_dep_length
);
232 /* The start and length of the stem of FILENAME for the current rule. */
233 const char *stem
= 0;
234 unsigned int stemlen
= 0;
235 unsigned int fullstemlen
= 0;
237 /* Buffer in which we store all the rules that are possibly applicable. */
238 struct tryrule
*tryrules
= xmalloc (num_pattern_rules
* max_pattern_targets
239 * sizeof (struct tryrule
));
241 /* Number of valid elements in TRYRULES. */
244 /* The index in TRYRULES of the rule we found. */
245 unsigned int foundrule
;
247 /* Nonzero if should consider intermediate files as dependencies. */
250 /* Nonzero if we have initialized file variables for this target. */
251 int file_vars_initialized
= 0;
253 /* Nonzero if we have matched a pattern-rule target
254 that is not just `%'. */
255 int specific_rule_matched
= 0;
257 struct dep dep_simple
;
259 unsigned int ri
; /* uninit checks OK */
262 char *pathdir
= NULL
;
263 unsigned long pathlen
;
265 PATH_VAR (stem_str
); /* @@ Need to get rid of stem, stemlen, etc. */
268 if (archive
|| ar_name (filename
))
273 /* Set LASTSLASH to point at the last slash in FILENAME
274 but not counting any slash at the end. (foo/bar/ counts as
275 bar/ in directory foo/, not empty in directory foo/bar/.) */
277 lastslash
= strrchr (filename
, ']');
279 lastslash
= strrchr (filename
, ':');
281 lastslash
= strrchr (filename
, '/');
282 #ifdef HAVE_DOS_PATHS
283 /* Handle backslashes (possibly mixed with forward slashes)
284 and the case of "d:file". */
286 char *bslash
= strrchr (filename
, '\\');
287 if (lastslash
== 0 || bslash
> lastslash
)
289 if (lastslash
== 0 && filename
[0] && filename
[1] == ':')
290 lastslash
= filename
+ 1;
294 if (lastslash
!= 0 && lastslash
[1] == '\0')
298 pathlen
= lastslash
- filename
+ 1;
300 /* First see which pattern rules match this target and may be considered.
301 Put them in TRYRULES. */
304 for (rule
= pattern_rules
; rule
!= 0; rule
= rule
->next
)
308 /* If the pattern rule has deps but no commands, ignore it.
309 Users cancel built-in rules by redefining them without commands. */
310 if (rule
->deps
!= 0 && rule
->cmds
== 0)
313 /* If this rule is in use by a parent pattern_search,
314 don't use it here. */
317 DBS (DB_IMPLICIT
, (_("Avoiding implicit rule recursion.\n")));
321 for (ti
= 0; ti
< rule
->num
; ++ti
)
323 const char *target
= rule
->targets
[ti
];
324 const char *suffix
= rule
->suffixes
[ti
];
327 /* Rules that can match any filename and are not terminal
328 are ignored if we're recursing, so that they cannot be
329 intermediate files. */
330 if (recursions
> 0 && target
[1] == '\0' && !rule
->terminal
)
333 if (rule
->lens
[ti
] > namelen
)
334 /* It can't possibly match. */
337 /* From the lengths of the filename and the pattern parts,
338 find the stem: the part of the filename that matches the %. */
339 stem
= filename
+ (suffix
- target
- 1);
340 stemlen
= namelen
- rule
->lens
[ti
] + 1;
342 /* Set CHECK_LASTSLASH if FILENAME contains a directory
343 prefix and the target pattern does not contain a slash. */
349 check_lastslash
= (strchr (target
, ']') == 0
350 && strchr (target
, ':') == 0);
352 check_lastslash
= strchr (target
, '/') == 0;
353 #ifdef HAVE_DOS_PATHS
354 /* Didn't find it yet: check for DOS-type directories. */
357 char *b
= strchr (target
, '\\');
358 check_lastslash
= !(b
|| (target
[0] && target
[1] == ':'));
365 /* If so, don't include the directory prefix in STEM here. */
366 if (pathlen
> stemlen
)
372 /* Check that the rule pattern matches the text before the stem. */
375 if (stem
> (lastslash
+ 1)
376 && !strneq (target
, lastslash
+ 1, stem
- lastslash
- 1))
379 else if (stem
> filename
380 && !strneq (target
, filename
, stem
- filename
))
383 /* Check that the rule pattern matches the text after the stem.
384 We could test simply use streq, but this way we compare the
385 first two characters immediately. This saves time in the very
386 common case where the first character matches because it is a
388 if (*suffix
!= stem
[stemlen
]
389 || (*suffix
!= '\0' && !streq (&suffix
[1], &stem
[stemlen
+ 1])))
392 /* Record if we match a rule that not all filenames will match. */
393 if (target
[1] != '\0')
394 specific_rule_matched
= 1;
396 /* A rule with no dependencies and no commands exists solely to set
397 specific_rule_matched when it matches. Don't try to use it. */
398 if (rule
->deps
== 0 && rule
->cmds
== 0)
401 /* Record this rule in TRYRULES and the index of the matching
402 target in MATCHES. If several targets of the same rule match,
403 that rule will be in TRYRULES more than once. */
404 tryrules
[nrules
].rule
= rule
;
405 tryrules
[nrules
].matches
= ti
;
406 tryrules
[nrules
].stemlen
= stemlen
+ (check_lastslash
? pathlen
: 0);
407 tryrules
[nrules
].order
= nrules
;
408 tryrules
[nrules
].checked_lastslash
= check_lastslash
;
413 /* Bail out early if we haven't found any rules. */
417 /* Sort the rules to place matches with the shortest stem first. This
418 way the most specific rules will be tried first. */
420 qsort (tryrules
, nrules
, sizeof (struct tryrule
), stemlen_compare
);
422 /* If we have found a matching rule that won't match all filenames,
423 retroactively reject any non-"terminal" rules that do always match. */
424 if (specific_rule_matched
)
425 for (ri
= 0; ri
< nrules
; ++ri
)
426 if (!tryrules
[ri
].rule
->terminal
)
429 for (j
= 0; j
< tryrules
[ri
].rule
->num
; ++j
)
430 if (tryrules
[ri
].rule
->targets
[j
][1] == '\0')
432 tryrules
[ri
].rule
= 0;
437 /* Try each rule once without intermediate files, then once with them. */
438 for (intermed_ok
= 0; intermed_ok
< 2; ++intermed_ok
)
442 /* Try each pattern rule till we find one that applies. If it does,
443 expand its dependencies (as substituted) and chain them in DEPS. */
444 for (ri
= 0; ri
< nrules
; ri
++)
448 unsigned int failed
= 0;
449 int file_variables_set
= 0;
450 unsigned int deps_found
= 0;
451 /* NPTR points to the part of the prereq we haven't processed. */
452 const char *nptr
= 0;
453 const char *dir
= NULL
;
455 unsigned int matches
;
457 rule
= tryrules
[ri
].rule
;
459 /* RULE is nil when we discover that a rule, already placed in
460 TRYRULES, should not be applied. */
464 /* Reject any terminal rules if we're looking to make intermediate
466 if (intermed_ok
&& rule
->terminal
)
469 /* From the lengths of the filename and the matching pattern parts,
470 find the stem: the part of the filename that matches the %. */
471 matches
= tryrules
[ri
].matches
;
472 stem
= filename
+ (rule
->suffixes
[matches
]
473 - rule
->targets
[matches
]) - 1;
474 stemlen
= (namelen
- rule
->lens
[matches
]) + 1;
475 check_lastslash
= tryrules
[ri
].checked_lastslash
;
481 /* We need to add the directory prefix, so set it up. */
484 pathdir
= alloca (pathlen
+ 1);
485 memcpy (pathdir
, filename
, pathlen
);
486 pathdir
[pathlen
] = '\0';
491 DBS (DB_IMPLICIT
, (_("Trying pattern rule with stem `%.*s'.\n"),
492 (int) stemlen
, stem
));
494 strncpy (stem_str
, stem
, stemlen
);
495 stem_str
[stemlen
] = '\0';
497 /* If there are no prerequisites, then this rule matches. */
501 /* Temporary assign STEM to file->stem (needed to set file
503 file
->stem
= stem_str
;
505 /* Mark this rule as in use so a recursive pattern_search won't try
509 /* Try each prerequisite; see if it exists or can be created. We'll
510 build a list of prereq info in DEPLIST. Due to 2nd expansion we
511 may have to process multiple prereqs for a single dep entry. */
515 nptr
= dep_name (dep
);
521 /* If we're out of name to parse, start the next prereq. */
527 nptr
= dep_name (dep
);
530 /* If we don't need a second expansion, just replace the %. */
531 if (! dep
->need_2nd_expansion
)
535 p
= strchr (nptr
, '%');
537 dep_simple
.name
= nptr
;
543 memcpy (o
, filename
, pathlen
);
546 memcpy (o
, nptr
, p
- nptr
);
548 memcpy (o
, stem_str
, stemlen
);
551 dep_simple
.name
= strcache_add (depname
);
555 /* We've used up this dep, so next time get a new one. */
560 /* We have to perform second expansion on this prereq. In an
561 ideal world we would take the dependency line, substitute the
562 stem, re-expand the whole line and chop it into individual
563 prerequisites. Unfortunately this won't work because of the
564 "check_lastslash" twist. Instead, we will have to go word by
565 word, taking $()'s into account. For each word we will
566 substitute the stem, re-expand, chop it up, and, if
567 check_lastslash != 0, add the directory part to each
568 resulting prerequisite. */
574 nptr
= get_next_word (nptr
, &len
);
578 /* See this is a transition to order-only prereqs. */
579 if (! order_only
&& len
== 1 && nptr
[0] == '|')
586 /* If the dependency name has %, substitute the stem. If we
587 just replace % with the stem value then later, when we do
588 the 2nd expansion, we will re-expand this stem value
589 again. This is not good if you have certain characters
590 in your stem (like $).
592 Instead, we will replace % with $* and allow the second
593 expansion to take care of it for us. This way (since $*
594 is a simple variable) there won't be additional
595 re-expansion of the stem. */
597 p
= lindex (nptr
, nptr
+ len
, '%');
600 memcpy (depname
, nptr
, len
);
605 unsigned int i
= p
- nptr
;
606 memcpy (depname
, nptr
, i
);
607 memcpy (depname
+ i
, "$*", 2);
608 memcpy (depname
+ i
+ 2, p
+ 1, len
- i
- 1);
609 depname
[len
+ 2 - 1] = '\0';
615 /* Initialize and set file variables if we haven't already
617 if (!file_vars_initialized
)
619 initialize_file_variables (file
, 0);
620 set_file_variables (file
);
621 file_vars_initialized
= 1;
623 /* Update the stem value in $* for this rule. */
624 else if (!file_variables_set
)
626 define_variable_for_file (
627 "*", 1, file
->stem
, o_automatic
, 0, file
);
628 file_variables_set
= 1;
631 /* Perform the 2nd expansion. */
632 p
= variable_expand_for_file (depname
, file
);
634 /* Parse the expanded string. */
635 dl
= PARSE_FILE_SEQ (&p
, struct dep
, order_only
? '\0' : '|',
636 add_dir
? dir
: NULL
, 0);
638 for (d
= dl
; d
!= NULL
; d
= d
->next
)
645 /* Set up for the next word. */
649 /* If there are more than max_pattern_deps prerequisites (due to
650 2nd expansion), reset it and realloc the arrays. */
652 if (deps_found
> max_pattern_deps
)
654 unsigned int l
= pat
- deplist
;
655 deplist
= xrealloc (deplist
,
656 deps_found
* sizeof (struct patdeps
));
658 max_pattern_deps
= deps_found
;
661 /* Go through the nameseq and handle each as a prereq name. */
662 for (d
= dl
; d
!= 0; d
= d
->next
)
665 int is_rule
= d
->name
== dep_name (dep
);
667 if (file_impossible_p (d
->name
))
669 /* If this prereq has already been ruled "impossible",
670 then the rule fails. Don't bother trying it on the
671 second pass either since we know that will fail. */
674 ? _("Rejecting impossible rule prerequisite `%s'.\n")
675 : _("Rejecting impossible implicit prerequisite `%s'.\n"),
677 tryrules
[ri
].rule
= 0;
683 memset (pat
, '\0', sizeof (struct patdeps
));
684 pat
->ignore_mtime
= d
->ignore_mtime
;
688 ? _("Trying rule prerequisite `%s'.\n")
689 : _("Trying implicit prerequisite `%s'.\n"), d
->name
));
691 /* If this prereq is also explicitly mentioned for FILE,
692 skip all tests below since it must be built no matter
693 which implicit rule we choose. */
695 for (expl_d
= file
->deps
; expl_d
!= 0; expl_d
= expl_d
->next
)
696 if (streq (dep_name (expl_d
), d
->name
))
700 (pat
++)->name
= d
->name
;
704 /* The DEP->changed flag says that this dependency resides
705 in a nonexistent directory. So we normally can skip
706 looking for the file. However, if CHECK_LASTSLASH is
707 set, then the dependency file we are actually looking for
708 is in a different directory (the one gotten by prepending
709 FILENAME's directory), so it might actually exist. */
711 /* @@ dep->changed check is disabled. */
712 if (lookup_file (d
->name
) != 0
713 /*|| ((!dep->changed || check_lastslash) && */
714 || file_exists_p (d
->name
))
716 (pat
++)->name
= d
->name
;
720 /* This code, given FILENAME = "lib/foo.o", dependency name
721 "lib/foo.c", and VPATH=src, searches for
724 const char *vname
= vpath_search (d
->name
, 0, NULL
, NULL
);
728 (_("Found prerequisite `%s' as VPATH `%s'\n"),
730 (pat
++)->name
= d
->name
;
735 /* We could not find the file in any place we should look.
736 Try to make this dependency as an intermediate file, but
737 only on the second pass. */
742 (_("Looking for a rule with intermediate file `%s'.\n"),
746 int_file
= alloca (sizeof (struct file
));
747 memset (int_file
, '\0', sizeof (struct file
));
748 int_file
->name
= d
->name
;
750 if (pattern_search (int_file
,
755 pat
->pattern
= int_file
->name
;
756 int_file
->name
= d
->name
;
757 pat
->file
= int_file
;
758 (pat
++)->name
= d
->name
;
763 /* If we have tried to find P as an intermediate file
764 and failed, mark that name as impossible so we won't
765 go through the search again later. */
766 if (int_file
->variables
)
767 free_variable_set (int_file
->variables
);
768 if (int_file
->pat_variables
)
769 free_variable_set (int_file
->pat_variables
);
770 file_impossible (d
->name
);
773 /* A dependency of this rule does not exist. Therefore, this
779 /* Free the ns chain. */
780 if (dl
!= &dep_simple
)
787 /* Reset the stem in FILE. */
791 /* This rule is no longer `in use' for recursive searches. */
795 /* This pattern rule does apply. Stop looking for one. */
798 /* This pattern rule does not apply. If some of its dependencies
799 succeeded, free the data structure describing them. */
800 /* free_idep_chain (deps); */
804 /* If we found an applicable rule without intermediate files, don't try
812 /* RULE is nil if the loop went through the list but everything failed. */
818 /* If we are recursing, store the pattern that matched FILENAME in
819 FILE->name for use in upper levels. */
823 file
->name
= rule
->targets
[tryrules
[foundrule
].matches
];
825 /* DEPLIST lists the prerequisites for the rule we found. This includes the
826 intermediate files, if any. Convert them into entries on the deps-chain
829 while (pat
-- > deplist
)
836 /* If we need to use an intermediate file, make sure it is entered
837 as a target, with the info that was found for it in the recursive
838 pattern_search call. We know that the intermediate file did not
839 already exist as a target; therefore we can assume that the deps
840 and cmds of F below are null before we change them. */
842 struct file
*imf
= pat
->file
;
843 struct file
*f
= lookup_file (imf
->name
);
845 /* We don't want to delete an intermediate file that happened
846 to be a prerequisite of some (other) target. Mark it as
851 f
= enter_file (imf
->name
);
856 f
->variables
= imf
->variables
;
857 f
->pat_variables
= imf
->pat_variables
;
858 f
->pat_searched
= imf
->pat_searched
;
859 f
->also_make
= imf
->also_make
;
862 f
->tried_implicit
= 1;
864 imf
= lookup_file (pat
->pattern
);
865 if (imf
!= 0 && imf
->precious
)
868 for (dep
= f
->deps
; dep
!= 0; dep
= dep
->next
)
870 dep
->file
= enter_file (dep
->name
);
872 dep
->file
->tried_implicit
|= dep
->changed
;
877 dep
->ignore_mtime
= pat
->ignore_mtime
;
878 s
= strcache_add (pat
->name
);
883 dep
->file
= lookup_file (s
);
885 dep
->file
= enter_file (s
);
888 if (pat
->file
== 0 && tryrules
[foundrule
].rule
->terminal
)
890 /* If the file actually existed (was not an intermediate file), and
891 the rule that found it was a terminal one, then we want to mark
892 the found file so that it will not have implicit rule search done
893 for it. If we are not entering a `struct file' for it now, we
894 indicate this with the `changed' flag. */
898 dep
->file
->tried_implicit
= 1;
901 dep
->next
= file
->deps
;
905 if (!tryrules
[foundrule
].checked_lastslash
)
907 /* Always allocate new storage, since STEM might be on the stack for an
908 intermediate file. */
909 file
->stem
= strcache_add_len (stem
, stemlen
);
910 fullstemlen
= stemlen
;
914 int dirlen
= (lastslash
+ 1) - filename
;
917 /* We want to prepend the directory from
918 the original FILENAME onto the stem. */
919 fullstemlen
= dirlen
+ stemlen
;
920 sp
= alloca (fullstemlen
+ 1);
921 memcpy (sp
, filename
, dirlen
);
922 memcpy (sp
+ dirlen
, stem
, stemlen
);
923 sp
[fullstemlen
] = '\0';
924 file
->stem
= strcache_add (sp
);
927 file
->cmds
= rule
->cmds
;
930 /* Set precious flag. */
932 struct file
*f
= lookup_file (rule
->targets
[tryrules
[foundrule
].matches
]);
933 if (f
&& f
->precious
)
937 /* If this rule builds other targets, too, put the others into FILE's
938 `also_make' member. */
941 for (ri
= 0; ri
< rule
->num
; ++ri
)
942 if (ri
!= tryrules
[foundrule
].matches
)
944 char *nm
= alloca (rule
->lens
[ri
] + fullstemlen
+ 1);
947 struct dep
*new = alloc_dep ();
949 /* GKM FIMXE: handle '|' here too */
950 memcpy (p
, rule
->targets
[ri
],
951 rule
->suffixes
[ri
] - rule
->targets
[ri
] - 1);
952 p
+= rule
->suffixes
[ri
] - rule
->targets
[ri
] - 1;
953 memcpy (p
, file
->stem
, fullstemlen
);
955 memcpy (p
, rule
->suffixes
[ri
],
956 rule
->lens
[ri
] - (rule
->suffixes
[ri
] - rule
->targets
[ri
])+1);
957 new->name
= strcache_add (nm
);
958 new->file
= enter_file (new->name
);
959 new->next
= file
->also_make
;
961 /* Set precious flag. */
962 f
= lookup_file (rule
->targets
[ri
]);
963 if (f
&& f
->precious
)
964 new->file
->precious
= 1;
966 /* Set the is_target flag so that this file is not treated as
967 intermediate by the pattern rule search algorithm and
968 file_exists_p cannot pick it up yet. */
969 new->file
->is_target
= 1;
971 file
->also_make
= new;