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Revision 518 - (hide annotations) (download)
Tue May 18 15:47:01 2010 UTC (4 years, 11 months ago) by ph10
File size: 186444 byte(s)
Added PCRE_UCP and related stuff to make \w etc use Unicode properties.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 513 Version 8.10 03 May-2010
5 ph10 510 ------------------------
7 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8 ph10 510 THEN.
10 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
11 ph10 510
12 ph10 513 3. Inside a character class, \B is treated as a literal by default, but
13     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14     causes the error). The code is unchanged, but I tidied the documentation.
16     4. Inside a character class, PCRE always treated \R and \X as literals,
17     whereas Perl faults them if its -w option is set. I have changed PCRE so
18     that it faults them when PCRE_EXTRA is set.
19 ph10 514
20     5. Added support for \N, which always matches any character other than
21     newline. (It is the same as "." when PCRE_DOTALL is not set.)
22 ph10 515
23     6. When compiling pcregrep with newer versions of gcc which may have
24     FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25     declared with attribute warn_unused_result" were given. Just casting the
26     result to (void) does not stop the warnings; a more elaborate fudge is
27     needed. I've used a macro to implement this.
28 ph10 516
29     7. Minor change to pcretest.c to avoid a compiler warning.
30 ph10 512
31 ph10 517 8. Added four artifical Unicode properties to help with an option to make
32 ph10 518 \s etc use properties (see next item). The new properties are: Xan
33     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
35     9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36     use Unicode properties. (*UCP) at the start of a pattern can be used to set
37     this option. Modified pcretest to add /W to test this facility. Added
38     REG_UCP to make it available via the POSIX interface.
39 ph10 513
40 ph10 517
41 ph10 508 Version 8.02 19-Mar-2010
42 ph10 491 ------------------------
44     1. The Unicode data tables have been updated to Unicode 5.2.0.
46 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
47     configured.
48 ph10 507
49 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
50 ph10 507 original author of that file, following a query about its status.
52     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
53 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
54 ph10 507
55 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
56     quantifier applied to a forward-referencing subroutine call, could compile
57     incorrect code or give the error "internal error: previously-checked
58     referenced subpattern not found".
59 ph10 507
60     6. Both MS Visual Studio and Symbian OS have problems with initializing
61 ph10 497 variables to point to external functions. For these systems, therefore,
62     pcre_malloc etc. are now initialized to local functions that call the
63     relevant global functions.
64 ph10 507
65 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
66     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
67 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
68     the lengths are correct (equal to the number of opcodes).
70     8. Following on from 7, I added a similar kludge to check the length of the
71     eint vector in pcreposix.c.
73     9. Error texts for pcre_compile() are held as one long string to avoid too
74     much relocation at load time. To find a text, the string is searched,
75 ph10 499 counting zeros. There was no check for running off the end of the string,
76     which could happen if a new error number was added without updating the
77 ph10 507 string.
79     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
81 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
82 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
83     \K is "not well defined" if used in an assertion. PCRE now accepts it if
84     the assertion is positive, but not if it is negative.
86 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
87 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
88     implementation of support for (*MARK) will need an extra pointer on the
89 ph10 501 stack; I have reserved it now, so that the stack frame size does not
90     decrease.
91 ph10 507
92     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
93     item in branch that calls a recursion is a subroutine call - as in the
94 ph10 503 second branch in the above example - was incorrectly given the compile-
95     time error "recursive call could loop indefinitely" because pcre_compile()
96 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
98 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
99 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
100 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
101 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
102 ph10 491
103 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
104 ph10 492
105 ph10 507
106 ph10 489 Version 8.01 19-Jan-2010
107     ------------------------
108 ph10 471
109     1. If a pattern contained a conditional subpattern with only one branch (in
110 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
111 ph10 473 computed the wrong minimum data length (which is of course zero for such
112 ph10 489 subpatterns). This could cause incorrect "no match" results.
113 ph10 473
114     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
115 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
116     "internal error: code overflow at offset...". This happened only when
117 ph10 473 the reset was to the original external option setting. (An optimization
118     abstracts leading options settings into an external setting, which was the
119 ph10 472 cause of this.)
120 ph10 471
121 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
122     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
123     assertion pattern did not match (meaning that the assertion was true), it
124     was incorrectly treated as false if the SKIP had been reached during the
125     matching. This also applied to assertions used as conditions.
126 ph10 471
127 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
128     assertion subpattern, including such a pattern used as a condition,
129     unpredictable results occurred, instead of the error return
131 ph10 478
132 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
133     situation when an empty string is matched. It now does the fancy magic
134 ph10 478 stuff that is necessary.
136     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
137 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
138 ph10 478
139 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
140     as part of something else:
141 ph10 478
142     (a) Change DEBUG to PCRE_DEBUG.
144     (b) In pcre_compile(), rename the member of the "branch_chain" structure
145     called "current" as "current_branch", to prevent a collision with the
146 ph10 475 Linux macro when compiled as a kernel module.
147 ph10 478
148     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
149     prevent a collision with the Linux macro when compiled as a kernel
150 ph10 475 module.
151 ph10 478
152 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
153     cast potentially large values to (double). This has been changed to that
154 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
155     instead, thus avoiding the use of floating point arithmetic. (There is no
156     other use of FP in PCRE.) If int64_t is not found, the fallback is to
157     double.
159     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
160 ph10 476 2005 (difference between two addresses compared to an unsigned value).
161 ph10 473
162 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
163     custom one, because of the following reported problem in Windows:
164 ph10 473
165 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
166 ph10 489 under Win32.
167 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
168 ph10 489 therefore missing the function definition.
169 ph10 478 - The compiler thus generates a "C" signature for the test function.
170     - The linker fails to find the "C" function.
171     - PCRE fails to configure if asked to do so against libbz2.
172 ph10 486
173 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
174     messages were output:
175 ph10 478
176 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
177     rerunning libtoolize, to keep the correct libtool macros in-tree.
178     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
179 ph10 486
180 ph10 479 I have done both of these things.
181 ph10 486
182 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
183 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
184     runaway infinite recursion. I updated the discussion in the pcrestack man
185     page.
187     13. Now that we have gone to the x.xx style of version numbers, the minor
188     version may start with zero. Using 08 or 09 is a bad idea because users
189     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
190     interpreted as invalid octal numbers. I've updated the previous comment in
191     configure.ac, and also added a check that gives an error if 08 or 09 are
192 ph10 481 used.
193 ph10 486
194 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
195 ph10 483 causing partial matching to fail when the end of the subject matched \W
196     in a UTF-8 pattern where \W was quantified with a minimum of 3.
197 ph10 486
198 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
199 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
200 ph10 483 their definitions. The declarations used "const uschar *" and the
201     definitions used USPTR. Even though USPTR is normally defined as "const
202     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
203     reported that: "This difference in casting confuses some C++ compilers, for
204     example, SunCC recognizes above declarations as different functions and
205 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
206 ph10 483 USPTR.
207 ph10 486
208     16. GNU libtool is named differently on some systems. The autogen.sh script now
209 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
210     (FreeBSD).
211 ph10 478
212 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
213     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
214     comment: "Figure out how to create a longlong from a string: strtoll and
215     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
216     instance, but it only takes 2 args instead of 3!"
217 ph10 479
218 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
219     specification, with a corresponding code fix. A pattern such as
220     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
221     refers, was giving matches when it shouldn't. For example, xa=xaaa would
222     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
223     same bug. Such groups have to be quantified to be useful, or contained
224     inside another quantified group. (If there's no repetition, the reference
225     can never match.) The problem arises because, having left the group and
226     moved on to the rest of the pattern, a later failure that backtracks into
227     the group uses the captured value from the final iteration of the group
228     rather than the correct earlier one. I have fixed this in PCRE by forcing
229     any group that contains a reference to itself to be an atomic group; that
230     is, there cannot be any backtracking into it once it has completed. This is
231     similar to recursive and subroutine calls.
232 ph10 486
233 ph10 488
234 ph10 469 Version 8.00 19-Oct-09
235 ph10 418 ----------------------
237     1. The table for translating pcre_compile() error codes into POSIX error codes
238 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
239     being within the table. This could lead to an OK return being given in
240 ph10 418 error.
241 ph10 461
242     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
243     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
244     in a Windows environment.
246 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
247     zero, as does GNU grep. However, pcregrep was also printing all files when
248     --files-with-matches was added. Now, when both options are given, it prints
249     counts only for those files that have at least one match. (GNU grep just
250 ph10 461 prints the file name in this circumstance, but including the count seems
251     more useful - otherwise, why use --count?) Also ensured that the
252 ph10 420 combination -clh just lists non-zero counts, with no names.
253 ph10 461
254     4. The long form of the pcregrep -F option was incorrectly implemented as
255     --fixed_strings instead of --fixed-strings. This is an incompatible change,
256     but it seems right to fix it, and I didn't think it was worth preserving
257     the old behaviour.
259     5. The command line items --regex=pattern and --regexp=pattern were not
260 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
261 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
262 ph10 422 which are compatible with GNU grep; these now work.
263 ph10 461
264     6. No libpcreposix.pc file was created for pkg-config; there was just
265 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
266 ph10 461
267 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
268 ph10 461 when UCP support is not needed, by modifying the Python script that
269 ph10 425 generates it from Unicode data files. This should not matter if the module
270     is correctly used as a library, but I received one complaint about 50K of
271     unwanted data. My guess is that the person linked everything into his
272     program rather than using a library. Anyway, it does no harm.
273 ph10 461
274 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
275 ph10 461 was a minimum greater than 1 for a wide character in a possessive
276 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
277     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
278     character. Chaos in the form of incorrect output or a compiling loop could
279     result.
280 ph10 461
281 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
282 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
283 ph10 426 partially matched by this function. In addition, if there are at least two
284 ph10 435 slots in the offset vector, the offset of the earliest inspected character
285     for the match and the offset of the end of the subject are set in them when
286 ph10 461 PCRE_ERROR_PARTIAL is returned.
288 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
289     synonymous with PCRE_PARTIAL, for backwards compatibility, and
290     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
291 ph10 462 and may be more useful for multi-segment matching.
292 ph10 461
293     11. Partial matching with pcre_exec() is now more intuitive. A partial match
294     used to be given if ever the end of the subject was reached; now it is
295     given only if matching could not proceed because another character was
296     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
297     string "Z", which now yields "no match" instead of "partial match". In the
298     case of pcre_dfa_exec(), "no match" is given if every matching path for the
299     final character ended with (*FAIL).
301 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
302 ph10 461 if the pattern had a "must contain" character that was already found in the
303 ph10 428 earlier partial match, unless partial matching was again requested. For
304     example, with the pattern /dog.(body)?/, the "must contain" character is
305     "g". If the first part-match was for the string "dog", restarting with
306 ph10 435 "sbody" failed. This bug has been fixed.
307 ph10 461
308     13. The string returned by pcre_dfa_exec() after a partial match has been
309     changed so that it starts at the first inspected character rather than the
310     first character of the match. This makes a difference only if the pattern
311     starts with a lookbehind assertion or \b or \B (\K is not supported by
312     pcre_dfa_exec()). It's an incompatible change, but it makes the two
313 ph10 435 matching functions compatible, and I think it's the right thing to do.
314 ph10 461
315 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
316 ph10 461 so that the demonstration program is easily available in environments where
317     PCRE has not been installed from source.
319 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
320 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
321     library.
322 ph10 461
323 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
324 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
325 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
326 ph10 433 these options useful.
327 ph10 461
328     17. If a caller to the POSIX matching function regexec() passes a non-zero
329 ph10 438 value for nmatch with a NULL value for pmatch, the value of
330 ph10 461 nmatch is forced to zero.
332 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
333 ph10 461 the diff command, as RunTest does. It now checks in the same way as
334 ph10 437 RunTest, and also checks for the -b option.
335 ph10 461
336 ph10 438 19. If an odd number of negated classes containing just a single character
337     interposed, within parentheses, between a forward reference to a named
338 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
339     an internal error, complaining that it could not find the referenced
340 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
341 ph10 461 [The bug was that it was starting one character too far in when skipping
342     over the character class, thus treating the ] as data rather than
343     terminating the class. This meant it could skip too much.]
345 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
346 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
347 ph10 442 to have an empty string match not at the start, even when the pattern is
348 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
350 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
351 ph10 461 than the maximum at the outer level, the higher number was returned, but
352     with unset values at the outer level. The correct (outer level) value is
353 ph10 446 now given.
354 ph10 461
355 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
356     PCRE did not set those parentheses (unlike Perl). I have now found a way to
357     make it do so. The string so far is captured, making this feature
358     compatible with Perl.
359 ph10 461
360     23. The tests have been re-organized, adding tests 11 and 12, to make it
361 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
362 ph10 461
363 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
364 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
365     does. Neither allows recursion.
367     25. I finally figured out how to implement a request to provide the minimum
368     length of subject string that was needed in order to match a given pattern.
369     (It was back references and recursion that I had previously got hung up
370     on.) This code has now been added to pcre_study(); it finds a lower bound
371 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
372     bound, but using it to avoid searching strings that are too short does give
373     some useful speed-ups. The value is available to calling programs via
374     pcre_fullinfo().
375 ph10 461
376 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
377     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
378     study optimizations had never been tested with that matching function.
379     Oops. What is worse, even when it was passed study data, there was a bug in
380     pcre_dfa_exec() that meant it never actually used it. Double oops. There
381     were also very few tests of studied patterns with pcre_dfa_exec().
382 ph10 461
383 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
384     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
385     on the other side of the coin, they are no longer allowed to have different
386     names, because these cannot be distinguished in PCRE, and this has caused
387     confusion. (This is a difference from Perl.)
388 ph10 461
389     28. When duplicate subpattern names are present (necessarily with different
390     numbers, as required by 27 above), and a test is made by name in a
391     conditional pattern, either for a subpattern having been matched, or for
392     recursion in such a pattern, all the associated numbered subpatterns are
393 ph10 459 tested, and the overall condition is true if the condition is true for any
394     one of them. This is the way Perl works, and is also more like the way
395     testing by number works.
396 ph10 418
397 ph10 461
398 ph10 412 Version 7.9 11-Apr-09
399 ph10 376 ---------------------
401 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
402 ph10 376 (pcretest), all targets were linked against these libraries. This included
403     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
404     libraries. This caused unwanted dependencies to be created. This problem
405 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
406 ph10 376 pcretest is linked with readline.
407 ph10 392
408 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
409     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
410     moved outside it again, because FALSE and TRUE are already defined in AIX,
411     but BOOL is not.
412 ph10 392
413     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
414 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
415 ph10 392
416 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
417     hyphens) following file names and line numbers when outputting matching
418 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
419 ph10 376 wording for the --colour (or --color) option.
420 ph10 392
421 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
422     was not coloured; this is different to GNU grep, so I have changed it to be
423     the same.
424 ph10 392
425 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
426 ph10 392 each matching line was coloured. Now it goes on to look for further matches
427     of any of the test patterns, which is the same behaviour as GNU grep.
429     7. A pattern that could match an empty string could cause pcregrep to loop; it
430     doesn't make sense to accept an empty string match in pcregrep, so I have
431 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
432     seems to be how GNU grep behaves.
433 ph10 392
434 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
435 ph10 392 start or after a newline", because the conditional assertion was not being
436     correctly handled. The rule now is that both the assertion and what follows
437     in the first alternative must satisfy the test.
439 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
440 ph10 399 condition was an assertion, PCRE could crash during matching, both with
441     pcre_exec() and pcre_dfa_exec().
442 ph10 392
443     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
444     used for matching.
446     11. Unicode property support in character classes was not working for
447 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
448 ph10 388
449 ph10 392 12. Added the -M command line option to pcretest.
451 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
452 ph10 389
453     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
454 ph10 390
455 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
456 ph10 390 wrapper.
457 ph10 392
458 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
459 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
460 ph10 391 string constants.
461 ph10 405
462 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
463     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
464 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
465     these, but not everybody uses configure.
467     19. A conditional group that had only one branch was not being correctly
468     recognized as an item that could match an empty string. This meant that an
469     enclosing group might also not be so recognized, causing infinite looping
470     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
471     with the subject "ab", where knowledge that the repeated group can match
472 ph10 396 nothing is needed in order to break the loop.
473 ph10 405
474 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
475 ph10 405 exec(), but without supplying a callout function, matching went wrong.
477     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
478     leak if the size of the offset vector was greater than 30. When the vector
479     is smaller, the saved offsets during recursion go onto a local stack
480     vector, but for larger vectors malloc() is used. It was failing to free
481     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
482 ph10 400 error, in fact).
483 ph10 405
484 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
485 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
486     problem, but was untidy.
487 ph10 376
488 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
489     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
490     included within another project.
491 ph10 411
492 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
493     slightly modified by me:
494 ph10 411
495     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
496     not building pcregrep.
498 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
499 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
501 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
502     duplicate group numbers, could behave incorrectly or give incorrect errors,
503     because when scanning forward to find the reference group, PCRE was not
504     taking into account the duplicate group numbers. A pattern such as
505     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
506 ph10 411
507     26. Changed a few more instances of "const unsigned char *" to USPTR, making
508     the feature of a custom pointer more persuasive (as requested by a user).
509 ph10 416
510 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
511 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
512     pre-defined.
513 ph10 392
514 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
516 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
517     in the configuration summary.
518 ph10 405
519 ph10 411
520 ph10 374 Version 7.8 05-Sep-08
521 ph10 349 ---------------------
523     1. Replaced UCP searching code with optimized version as implemented for Ad
524     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
525 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
526     to 5 times on some simple patterns that I tested. Permission was given to
527     distribute the MultiStage2.py script that generates the tables (it's not in
528     the tarball, but is in the Subversion repository).
529 ph10 349
530 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
531     scripts.
532 ph10 358
533 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
534     a group with a zero qualifier. The result of the study could be incorrect,
535 ph10 358 or the function might crash, depending on the pattern.
537     4. Caseless matching was not working for non-ASCII characters in back
538 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
539 ph10 358 It now works when Unicode Property Support is available.
541 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
542     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
543     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
544 ph10 358 truncation.
545 ph10 349
546 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
548 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
549     pointers, in case they are 64-bit values.
550 ph10 371
551     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
552     test 2 if it fails.
554 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
555 ph10 371 and a #define of that name to empty if it is not externally set. This is to
556     allow users of MSVC to set it if necessary.
558     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
559 ph10 359 the convenience functions in the pcre_get.c source file.
560 ph10 371
561 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
562     could cause overwriting and/or a crash. This command provoked a crash in
563 ph10 371 some environments:
565     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
567 ph10 360 This potential security problem was recorded as CVE-2008-2371.
568 ph10 371
569 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
570     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
571 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
572 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
573     pcretest so that it places the subject at the end of its malloc-ed buffer.
574 ph10 371
575 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
576 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
578 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
579 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
580     first line. This applied both to normal and DFA matching.
582 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
583 ph10 371 /^[^d]*?$/8 failed to match "abc".
584 ph10 351
585 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
587     17. Make it more clear in the documentation that values returned from
588 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
589 ph10 357
590 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
591 ph10 368
592 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
593     supplied by Stefan Weber. I made a further small update for 7.8 because
594 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
595     replaced by pcre_ucd.c.
596 ph10 371
597 ph10 373
598 ph10 347 Version 7.7 07-May-08
599 ph10 321 ---------------------
601     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
602 ph10 345 a string to a long long, pretend we don't even have a long long." This is
603 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
604 ph10 345
605 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
606     pre-7.6 versions, which defined a global no_arg variable instead of putting
607 ph10 332 it in the RE class. (See also #8 below.)
608 ph10 345
609     3. Remove a line of dead code, identified by coverity and reported by Nuno
610     Lopes.
612 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
613 ph10 321
614 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
615 ph10 345 of files, instead of just to the final components.
617 ph10 324 (2) If there was more than one level of directory, the subdirectories were
618     skipped unless they satisfied the include/exclude conditions. This is
619     inconsistent with GNU grep (and could even be seen as contrary to the
620     pcregrep specification - which I improved to make it absolutely clear).
621     The action now is always to scan all levels of directory, and just
622     apply the include/exclude patterns to regular files.
623 ph10 345
624 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
625 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
627 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
628 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
629 ph10 326 doesn't support NULs in patterns.
630 ph10 345
631     7. Added some missing "const"s to declarations of static tables in
632     pcre_compile.c and pcre_dfa_exec.c.
634 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
635 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
636 ph10 345 first patch. And a third patch - this was a messy problem.)
637 ph10 321
638 ph10 345 9. Applied Craig's patch to remove the use of push_back().
640 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
641     matching function regexec().
642 ph10 345
643     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
644     which, however, unlike Perl's \g{...}, are subroutine calls, not back
645 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
646     Oniguruma does).
647 ph10 345
648     12. Previously, a group with a zero repeat such as (...){0} was completely
649 ph10 335 omitted from the compiled regex. However, this means that if the group
650     was called as a subroutine from elsewhere in the pattern, things went wrong
651 ph10 345 (an internal error was given). Such groups are now left in the compiled
652     pattern, with a new opcode that causes them to be skipped at execution
653 ph10 335 time.
654 ph10 345
655 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
656     to the way PCRE behaves:
657 ph10 345
658 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
659 ph10 345
660     (b) A back reference to an unmatched subpattern matches an empty string
661 ph10 336 (Perl fails the current match path).
662 ph10 345
663 ph10 341 (c) A data ] in a character class must be notated as \] because if the
664 ph10 345 first data character in a class is ], it defines an empty class. (In
665 ph10 341 Perl it is not possible to have an empty class.) The empty class []
666     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
667     The negative empty class [^] matches any one character, independently
668     of the DOTALL setting.
669 ph10 345
670     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
671 ph10 340 non-existent subpattern following a character class starting with ']' and
672     containing () gave an internal compiling error instead of "reference to
673     non-existent subpattern". Fortunately, when the pattern did exist, the
674 ph10 345 compiled code was correct. (When scanning forwards to check for the
675 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
676 ph10 345 the class, so got the count wrong. When actually compiling, the reference
677 ph10 340 was subsequently set up correctly.)
678 ph10 345
679 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
680 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
681     other assertions are supported. I have made pcre_dfa_exec() support
682     (*FAIL).
684 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
685 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
686     cannot be changed at match time, I realized I could make a small
687     improvement to matching performance by compiling OP_ALLANY instead of
688     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
689     on the OP_ANY path.
691     17. Compiling pcretest on Windows with readline support failed without the
692 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
693 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
695 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
696 ph10 345 ncurses library to be included for pcretest when ReadLine support is
697     requested, but also to allow for it to be overridden. This patch came from
698     Daniel Bergström.
699 ph10 347
700 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
701 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
702     any errors with the current Unicode tables. Thanks to Peter Kankowski for
703     spotting this.
704 ph10 324
705 ph10 332
706 ph10 319 Version 7.6 28-Jan-08
707 ph10 300 ---------------------
709 ph10 302 1. A character class containing a very large number of characters with
710     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
711     overflow.
712 ph10 309
713     2. Patch to cut out the "long long" test in pcrecpp_unittest when
714     HAVE_LONG_LONG is not defined.
716 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
717 ph10 304 bring them up to date and include new features. This patch includes:
718 ph10 309
719 ph10 304 - Fixed PH's badly added libz and libbz2 support.
720     - Fixed a problem with static linking.
721 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
722 ph10 304 - Fixed dftables problem and added an option.
723     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
725     - Added readline support for pcretest.
726 ph10 309 - Added an listing of the option settings after cmake has run.
728 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
729     "pcre.dll" under mingw when using Configure/Make. I added stuff to
730     Makefile.am that cause it to include this special target, without
731     affecting anything else. Note that the same mingw target plus all
732     the other distribution libraries and programs are now supported
733     when configuring with CMake (see 6 below) instead of with
734     Configure/Make.
735 ph10 309
736 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
737     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
738 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
739     solves the problem, but it does no harm.
740 ph10 313
741 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
742 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
743 ph10 314 with CMake, and also correct the comment about stack recursion.
744 ph10 313
745 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
746 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
747     of a program that users should build themselves after PCRE is installed, so
748     building it automatically is not really right. What is more, it gave
749 ph10 312 trouble in some build environments.
750 ph10 300
751 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
752 ph10 308
753 ph10 319
754 ph10 298 Version 7.5 10-Jan-08
755 ph10 263 ---------------------
757     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
758     values in parens when parsing an RE using the C++ wrapper."
759 ph10 286
760 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
761     Characters greater than 255 were excluded from the class instead of being
762     included.
763 ph10 286
764     3. The same bug as (2) above applied to negated POSIX classes such as
765 ph10 265 [:^space:].
766 ph10 286
767 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
768     defined or documented. It seems to have been a typo for PCRE_STATIC, so
769 ph10 286 I have changed it.
771 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
772 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
773     first named subpattern whose name started with "a" (in other words, the
774 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
775     expected" is now given for (?&) (a zero-length name), and this patch also
776     makes it give the same error for \k'' (previously it complained that that
777     was a reference to a non-existent subpattern).
778 ph10 286
779 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
780 ph10 286 this is right because (?- can be followed by option settings as well as by
781 ph10 269 digits. I have, however, made the messages clearer.
782 ph10 286
783 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
784     than the number used in the conditional) now cause a compile-time error.
785     This is actually not compatible with Perl, which accepts such patterns, but
786     treats the conditional as always being FALSE (as PCRE used to), but it
787     seems to me that giving a diagnostic is better.
788 ph10 286
789 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
790 ph10 275 and messages.
791 ph10 286
792     9. Fix two occurrences of "backslash" in comments that should have been
793     "backspace".
795     10. Remove two redundant lines of code that can never be obeyed (their function
796     was moved elsewhere).
798     11. The program that makes PCRE's Unicode character property table had a bug
799     which caused it to generate incorrect table entries for sequences of
800 ph10 277 characters that have the same character type, but are in different scripts.
801 ph10 286 It amalgamated them into a single range, with the script of the first of
802 ph10 277 them. In other words, some characters were in the wrong script. There were
803     thirteen such cases, affecting characters in the following ranges:
804 ph10 286
805 ph10 277 U+002b0 - U+002c1
806     U+0060c - U+0060d
807 ph10 286 U+0061e - U+00612
808 ph10 277 U+0064b - U+0065e
809     U+0074d - U+0076d
810     U+01800 - U+01805
811     U+01d00 - U+01d77
812     U+01d9b - U+01dbf
813     U+0200b - U+0200f
814     U+030fc - U+030fe
815     U+03260 - U+0327f
816     U+0fb46 - U+0fbb1
817     U+10450 - U+1049d
818 ph10 286
819 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
820     compatible with GNU grep in that, if there was more than one match in a
821     line, it showed only the first of them. It now behaves in the same way as
822     GNU grep.
823 ph10 286
824     13. If the -o and -v options were combined for pcregrep, it printed a blank
825     line for every non-matching line. GNU grep prints nothing, and pcregrep now
826     does the same. The return code can be used to tell if there were any
827     non-matching lines.
829 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
831     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
832 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
833 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
834     and both kinds of lookbehind were skipped).
836 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
837 ph10 284 inclusion of <windows.h> to before rather than after the definition of
838     INVALID_FILE_ATTRIBUTES (patch from David Byron).
839 ph10 263
840 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
841 ph10 286 character property caused pcre_compile() to compile bad code, which led at
842     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
843     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
844     caused the error; without that there was no problem.
845 ph10 263
846 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
847 ph10 286
848 ph10 289 19. Added --enable-pcretest-libreadline.
849 ph10 286
850 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
851 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
852 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
853     later patch that removed the other one (the right fix) and added unit tests
854     that check the return values (which was not done before).
855 ph10 292
856 ph10 291 21. Several CMake things:
857 ph10 287
858 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
859 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
860 ph10 288
861 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
862     linked with the newly-built libraries, not previously installed ones.
863 ph10 291
865 ph10 298
866     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
867     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
868     UTF-8 newline character). The key issue is that the pattern starts .*;
869     this means that the match must be either at the beginning, or after a
870     newline. The bug was in the code for advancing after a failed match and
871     checking that the new position followed a newline. It was not taking
872 ph10 294 account of UTF-8 characters correctly.
873 ph10 298
874     23. PCRE was behaving differently from Perl in the way it recognized POSIX
875     character classes. PCRE was not treating the sequence [:...:] as a
876     character class unless the ... were all letters. Perl, however, seems to
877     allow any characters between [: and :], though of course it rejects as
878     unknown any "names" that contain non-letters, because all the known class
879     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
880     for example, whereas PCRE did not - it did not recognize a POSIX character
881     class. This seemed a bit dangerous, so the code has been changed to be
882     closer to Perl. The behaviour is not identical to Perl, because PCRE will
883     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
884     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
885     Perl does, and where it didn't before.
887 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
888     Windows environments %n is disabled by default.
889 ph10 292
891 ph10 260 Version 7.4 21-Sep-07
892 ph10 230 ---------------------
894     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
895 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
896     LF". That isn't really right - the whole point of the change was to try to
897     help when there was an actual mention of one of the two characters. So now
898     the change happens only if \r or \n (or a literal CR or LF) character is
899 ph10 230 encountered.
900 ph10 231
901     2. The 32-bit options word was also used for 6 internal flags, but the numbers
902     of both had grown to the point where there were only 3 bits left.
903     Fortunately, there was spare space in the data structure, and so I have
904     moved the internal flags into a new 16-bit field to free up more option
905 ph10 230 bits.
906 ph10 231
907     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
908     but did not set the internal JCHANGED flag - either of these is enough to
909     control the way the "get" function works - but the PCRE_INFO_JCHANGED
910     facility is supposed to tell if (?J) was ever used, so now (?J) at the
911 ph10 230 start sets both bits.
913 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
914     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
915 ph10 230
916 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
918     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
919 ph10 233 compatibility, even though it is no longer used.
920 ph10 243
921     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
922 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
923 ph10 259 windows.h file is present (where different names are used). [This was
924 ph10 257 reversed later after testing - see 16 below.]
925 ph10 243
926     8. Changed all #include <config.h> to #include "config.h". There were also
927 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
928 ph10 243
929 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
930 ph10 243 sequence off the lines that it output.
932     10. It was pointed out to me that arrays of string pointers cause lots of
933     relocations when a shared library is dynamically loaded. A technique of
934     using a single long string with a table of offsets can drastically reduce
935     these. I have refactored PCRE in four places to do this. The result is
936 ph10 240 dramatic:
937 ph10 243
938 ph10 240 Originally: 290
939     After changing UCP table: 187
940 ph10 243 After changing error message table: 43
941 ph10 240 After changing table of "verbs" 36
942     After changing table of Posix names 22
943 ph10 243
944 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
945 ph10 247
946 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
947 ph10 247 unicode-properties was also set.
949 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
950 ph10 231
951 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
952     checked only for CRLF.
953 ph10 233
954 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
956 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
957 ph10 253
958 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
959 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
960     entirely. This removes changes made in 7 above.
961 ph10 256
962 ph10 261 17. The CMake files have been updated, and there is now more information about
963     building with CMake in the NON-UNIX-USE document.
964 ph10 257
965 ph10 261
966 ph10 228 Version 7.3 28-Aug-07
967 ph10 157 ---------------------
969 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
970     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
971     brackets there is not right, since it causes compilers to look for an
972     installed pcre.h, not the version that is in the source that is being
973     compiled (which of course may be different). I have changed it back to:
974 ph10 197
975 ph10 189 #include "pcre.h"
976 ph10 197
977     I have a vague recollection that the change was concerned with compiling in
978     different directories, but in the new build system, that is taken care of
979     by the VPATH setting the Makefile.
981 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
982     when the subject happened to end in the byte 0x85 (e.g. if the last
983     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
984     characters but of course it shouldn't be taken as a newline when it is part
985     of another character. The bug was that, for an unlimited repeat of . in
986     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
987     characters when looking for a newline.
988 ph10 197
989     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
991     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
992     in debug output.
994 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
995     long printing in the pcrecpp unittest when running under MinGW.
996 ph10 189
997 ph10 197 6. ESC_K was left out of the EBCDIC table.
998 ph10 189
999 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1000     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1001     limit also applies to "virtual nesting" when a pattern is recursive, and in
1002     this case 1000 isn't so big. I have been able to remove this limit at the
1003     expense of backing off one optimization in certain circumstances. Normally,
1004     when pcre_exec() would call its internal match() function recursively and
1005     immediately return the result unconditionally, it uses a "tail recursion"
1006     feature to save stack. However, when a subpattern that can match an empty
1007     string has an unlimited repetition quantifier, it no longer makes this
1008     optimization. That gives it a stack frame in which to save the data for
1009     checking that an empty string has been matched. Previously this was taken
1010     from the 1000-entry workspace that had been reserved. So now there is no
1011     explicit limit, but more stack is used.
1012 ph10 189
1013 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1014     syntax that is required for Windows, and which was going wrong for the
1015     pcreposix and pcrecpp parts of the library. These were overlooked when this
1016     problem was solved for the main library.
1017 ph10 197
1018 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1019     the size of patterns that contain repeated groups with explicit upper
1020     limits. As the maximum quantifier is 65535, the maximum group length was
1021     set at 30,000 so that the product of these two numbers did not overflow a
1022     32-bit integer. However, it turns out that people want to use groups that
1023     are longer than 30,000 bytes (though not repeat them that many times).
1024     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1025     made it possible to implement the integer overflow checks in a much more
1026     dynamic way, which I have now done. The artificial limitation on group
1027     length has been removed - we now have only the limit on the total length of
1028     the compiled pattern, which depends on the LINK_SIZE setting.
1029 ph10 208
1030     10. Fixed a bug in the documentation for get/copy named substring when
1031     duplicate names are permitted. If none of the named substrings are set, the
1032     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1033     empty string.
1035     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1036     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1037     because the ] is interpreted as the first data character and the
1038     terminating ] is not found. PCRE has been made compatible with Perl in this
1039     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1040     cause memory overwriting.
1042 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1043     string has been matched (to stop an infinite loop). It was not recognizing
1044 ph10 208 a conditional subpattern that could match an empty string if that
1045 ph10 206 subpattern was within another subpattern. For example, it looped when
1046 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1047 ph10 206 condition was not nested. This bug has been fixed.
1048 ph10 208
1049 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1050     past the start of the subject in the presence of bytes with the top bit
1051     set, for example "\x8aBCD".
1052 ph10 211
1053 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1054     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1055 ph10 200
1056 ph10 211 14. Optimized (?!) to (*FAIL).
1057 ph10 202
1058 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1059     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1060     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1061     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1062     does: it's just the validity check that is more restrictive.
1063 ph10 220
1064     16. Inserted checks for integer overflows during escape sequence (backslash)
1065     processing, and also fixed erroneous offset values for syntax errors during
1066     backslash processing.
1068 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1069 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1071 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1072     caused an overrun.
1073 ph10 220
1074     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1075     something other than just ASCII characters) inside a group that had an
1076     unlimited repeat caused a loop at compile time (while checking to see
1077     whether the group could match an empty string).
1079 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1080     [\P{Any}] did so. (Error in the code for printing property names.)
1081 ph10 210
1082 ph10 220 21. An orphan \E inside a character class could cause a crash.
1084     22. A repeated capturing bracket such as (A)? could cause a wild memory
1085 ph10 218 reference during compilation.
1086 ph10 220
1087     23. There are several functions in pcre_compile() that scan along a compiled
1088     expression for various reasons (e.g. to see if it's fixed length for look
1089 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1090 ph10 220 present in the pattern. These operators have additional parameters compared
1091     with \d, etc, and these were not being taken into account when moving along
1092 ph10 218 the compiled data. Specifically:
1093 ph10 220
1094     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1095     length.
1097     (b) An item such as \pL+ within a repeated group could cause crashes or
1098 ph10 218 loops.
1099 ph10 220
1100 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1101 ph10 220 "reference to non-existent subpattern" error.
1103 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1105 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1106 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1107 ph10 211
1108 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1109 ph10 218
1110 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1111 ph10 223 character were causing crashes (broken optimization).
1112 ph10 227
1113 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1114 ph10 227 \p or \P) caused a compile-time loop.
1116 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1117     break. For example, the unstudied pattern [\r\n]A does not match the string
1118     "\r\nA" because change 7.0/46 below moves the current point on by two
1119     characters after failing to match at the start. However, the pattern \nA
1120 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1121     the same is true. There doesn't seem any very clean way out of this, but
1122     what I have chosen to do makes the common cases work: PCRE now takes note
1123     of whether there can be an explicit match for \r or \n anywhere in the
1124     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1125     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1126     pattern has explicit CR or LF references.
1127 ph10 222
1128 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1129 ph10 223
1130 ph10 227
1131 ph10 189 Version 7.2 19-Jun-07
1132     ---------------------
1134 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1135     which is apparently normally available under Windows.
1136 ph10 159
1137     2. Re-jig the pcregrep tests with different newline settings in an attempt
1138     to make them independent of the local environment's newline setting.
1139 ph10 157
1140 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1141 ph10 165
1142 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1143     was not 2, because the output contained actual offsets. The recent new
1144 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1145     usable with all link sizes.
1147 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1148     stack recursion. This gives a massive performance boost under BSD, but just
1149 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1150 ph10 164 in all cases.
1151 ph10 172
1152 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1153 ph10 172
1154 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1155     recursion call. It refers to the nth most recently opened parentheses.
1156 ph10 172
1157 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1158 ph10 172 to be opened parentheses.
1160     (c) Conditions that refer to capturing parentheses can be specified
1161 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1162 ph10 172
1163 ph10 168 (d) \K resets the start of the current match so that everything before
1164 ph10 172 is not part of it.
1166 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1167 ph10 172
1168 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1169 ph10 172 reference syntax.
1170 ph10 182
1171 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1172 ph10 182 alternative starts with the same number.
1173 ph10 172
1174 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1176 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1179     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1180     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1181 ph10 170 for detecting groups that can match an empty string.
1182 ph10 159
1183 ph10 172 9. A pattern with a very large number of alternatives (more than several
1184     hundred) was running out of internal workspace during the pre-compile
1185     phase, where pcre_compile() figures out how much memory will be needed. A
1186     bit of new cunning has reduced the workspace needed for groups with
1187     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1188     workspace instead of running out of the 4096 that are available.
1189 ph10 182
1190 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1191 ph10 172
1192 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1193     The report of the bug said:
1194 ph10 182
1195 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1196     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1197 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1198 ph10 185
1199 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1200 ph10 185 it matched the wrong number of bytes.
1201 ph10 172
1202 ph10 179
1203 ph10 155 Version 7.1 24-Apr-07
1204 ph10 98 ---------------------
1206 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1207 ph10 122 that is more "standard", making use of automake and other Autotools. There
1208 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1209     on this.
1210 ph10 111
1211     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1212     for recursive directory scanning broke on some systems because the files
1213     are not scanned in any specific order and on different systems the order
1214     was different. A call to "sort" has been inserted into RunGrepTest for the
1215     approprate test as a short-term fix. In the longer term there may be an
1216 ph10 100 alternative.
1217 ph10 111
1218 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1219 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1220     people do their own conversions for various reasons). The problems
1221     concerned the use of low-level troff macros .br and .in. I have therefore
1222     removed all such uses from the man pages (some were redundant, some could
1223 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1224     HTML has been updated to handle .nf/.fi and to complain if it encounters
1225     .br or .in.
1226 ph10 111
1227 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1228 ph10 123 arranged for config.h to be included in the distribution, with the name
1229 ph10 111 config.h.generic, for the benefit of those who have to compile without
1230     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1232     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1233     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1234 ph10 127 makevp.bat for the current PCRE, using the additional files
1235 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1236 ph10 111
1237     6. A Windows user reported a minor discrepancy with test 2, which turned out
1238     to be caused by a trailing space on an input line that had got lost in his
1239 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1240 ph10 111
1241 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1242 ph10 111 that is needed.
1244 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1245     as "const" (a) because they are and (b) because it helps the PHP
1246     maintainers who have recently made a script to detect big data structures
1247 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1248     to update Builducptable as well, so it won't revert if ucptable.h is ever
1249 ph10 105 re-created.
1250 ph10 111
1251     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1252 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1253 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1254     support is not required. This saves 1.5-2K of code, which is important in
1255 ph10 107 some applications.
1256 ph10 111
1257 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1258 ph10 111 so as not to refer to the tables, even though these functions will never be
1259     called when UTF-8 support is disabled. Otherwise there are problems with a
1260     shared library.
1262 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1264     (a) It was defining its arguments as char * instead of void *.
1266 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1267     a long time ago when I wrote it, but is no longer the case.
1269 ph10 118 The emulated memove() is provided for those environments that have neither
1270 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1271 ph10 118 is clearly not the case, as these two bugs were recently reported.
1272 ph10 123
1273 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1274 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1275     pages, and it removes trailing spaces from listed files. It also creates
1276     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1277     case, it wraps all the #defines with #ifndefs. This script should be run
1278 ph10 111 before "make dist".
1279 ph10 123
1280 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1281     with Unicode property support.
1282 ph10 123
1283     (a) For a maximizing quantifier, if the two different cases of the
1284     character were of different lengths in their UTF-8 codings (there are
1285     some cases like this - I found 11), and the matching function had to
1286 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1287     were both the same length.
1288 ph10 123
1289     (b) When PCRE was configured to use the heap rather than the stack for
1290     recursion during matching, it was not correctly preserving the data for
1291     the other case of a UTF-8 character when checking ahead for a match
1292     while processing a minimizing repeat. If the check also involved
1293 ph10 115 matching a wide character, but failed, corruption could cause an
1294     erroneous result when trying to check for a repeat of the original
1295     character.
1296 ph10 123
1297 ph10 116 13. Some tidying changes to the testing mechanism:
1298 ph10 98
1299 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1300     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1301 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1302     this for UTF-8.) The configure.ac script no longer substitutes the
1303     relevant variables.
1305 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1306     with length and offset values. This means that the output is different
1307     for different internal link sizes. Test 2 is skipped for link sizes
1308     other than 2 because of this, bypassing the problem. Unfortunately,
1309     there was also a test in test 3 (the locale tests) that used /B and
1310 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1311     I have added a new /Z option to pcretest that replaces the length and
1312     offset values with spaces. This is now used to make test 3 independent
1313 ph10 122 of link size. (Test 2 will be tidied up later.)
1314 ph10 123
1315     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1316 ph10 122 segmentation fault instead of returning the appropriate error message.
1317 ph10 134
1318 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1319 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1320     This doesn't seem right; it now treats the CRLF combination as the line
1321     ending, and so does not match in that case. It's only a pattern such as ^$
1322     that would hit this one: something like ^ABC$ would have failed after \r
1323     and then tried again after \r\n.
1325 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1326 ph10 134 in an attempt to make files that differ only in their line terminators
1327     compare equal. This works on Linux.
1328 ph10 142
1329 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1330     as it exited. This is now fixed, thanks to valgrind.
1331 ph10 142
1332 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1333 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1334     was because its rules for how to advance for /g after matching an empty
1335 ph10 143 string at the end of a line did not allow for this case. They now check for
1336     it specially.
1337 ph10 150
1338     20. pcretest is supposed to handle patterns and data of any length, by
1339     extending its buffers when necessary. It was getting this wrong when the
1340 ph10 147 buffer for a data line had to be extended.
1341 ph10 150
1342 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1343 ph10 150 CRLF as a newline sequence.
1344 ph10 152
1345 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1346 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1347     I have nevertheless tidied it up.
1348 ph10 111
1349 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1350 ph10 123
1351 ph10 153 24. Added a man page for pcre-config.
1352 ph10 152
1353 ph10 153
1354 nigel 93 Version 7.0 19-Dec-06
1355     ---------------------
1357     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1358     moving to gcc 4.1.1.
1360     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1361     sys/time.h, which is documented as needed for this function. It doesn't
1362     seem to matter on Linux, but it showed up on some releases of OS X.
1364     3. It seems that there are systems where bytes whose values are greater than
1365     127 match isprint() in the "C" locale. The "C" locale should be the
1366     default when a C program starts up. In most systems, only ASCII printing
1367     characters match isprint(). This difference caused the output from pcretest
1368     to vary, making some of the tests fail. I have changed pcretest so that:
1370     (a) When it is outputting text in the compiled version of a pattern, bytes
1371     other than 32-126 are always shown as hex escapes.
1373     (b) When it is outputting text that is a matched part of a subject string,
1374     it does the same, unless a different locale has been set for the match
1375     (using the /L modifier). In this case, it uses isprint() to decide.
1377     4. Fixed a major bug that caused incorrect computation of the amount of memory
1378     required for a compiled pattern when options that changed within the
1379     pattern affected the logic of the preliminary scan that determines the
1380     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1381     that the computed length was too small. The symptoms of this bug were
1382     either the PCRE error "internal error: code overflow" from pcre_compile(),
1383     or a glibc crash with a message such as "pcretest: free(): invalid next
1384     size (fast)". Examples of patterns that provoked this bug (shown in
1385     pcretest format) are:
1387     /(?-x: )/x
1388     /(?x)(?-x: \s*#\s*)/
1389     /((?i)[\x{c0}])/8
1390     /(?i:[\x{c0}])/8
1392     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1393     is now done differently.
1395     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1396     wrapper classes; (b) implement a new function in the C++ scanner that is
1397     more efficient than the old way of doing things because it avoids levels of
1398     recursion in the regex matching; (c) add a paragraph to the documentation
1399     for the FullMatch() function.
1401     6. The escape sequence \n was being treated as whatever was defined as
1402     "newline". Not only was this contrary to the documentation, which states
1403     that \n is character 10 (hex 0A), but it also went horribly wrong when
1404     "newline" was defined as CRLF. This has been fixed.
1406     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1407     was being set to -1 for the "end of line" case (supposedly a value that no
1408     character can have). Though this value is never used (the check for end of
1409     line is "zero bytes in current character"), it caused compiler complaints.
1410     I've changed it to 0xffffffff.
1412     8. In pcre_version.c, the version string was being built by a sequence of
1413     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1414     string (as it is for production releases) called a macro with an empty
1415     argument. The C standard says the result of this is undefined. The gcc
1416     compiler treats it as an empty string (which was what was wanted) but it is
1417     reported that Visual C gives an error. The source has been hacked around to
1418     avoid this problem.
1420     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1421     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1422     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1423     of them did).
1425     10. Originally, pcretest opened its input and output without "b"; then I was
1426     told that "b" was needed in some environments, so it was added for release
1427     5.0 to both the input and output. (It makes no difference on Unix-like
1428     systems.) Later I was told that it is wrong for the input on Windows. I've
1429     now abstracted the modes into two macros, to make it easier to fiddle with
1430     them, and removed "b" from the input mode under Windows.
1432     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1434     12. Added -help and --help to pcretest as an official way of being reminded
1435     of the options.
1437     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1438     and pcrecpp.cc because they annoy compilers at high warning levels.
1440     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1442     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1443     scripts are not C programs :-) and which was not noticed because it works
1444     on Linux.
1446     16. pcretest is supposed to handle any length of pattern and data line (as one
1447     line or as a continued sequence of lines) by extending its input buffer if
1448     necessary. This feature was broken for very long pattern lines, leading to
1449     a string of junk being passed to pcre_compile() if the pattern was longer
1450     than about 50K.
1452     17. I have done a major re-factoring of the way pcre_compile() computes the
1453     amount of memory needed for a compiled pattern. Previously, there was code
1454     that made a preliminary scan of the pattern in order to do this. That was
1455     OK when PCRE was new, but as the facilities have expanded, it has become
1456     harder and harder to keep it in step with the real compile phase, and there
1457     have been a number of bugs (see for example, 4 above). I have now found a
1458     cunning way of running the real compile function in a "fake" mode that
1459     enables it to compute how much memory it would need, while actually only
1460     ever using a few hundred bytes of working memory and without too many
1461     tests of the mode. This should make future maintenance and development
1462     easier. A side effect of this work is that the limit of 200 on the nesting
1463     depth of parentheses has been removed (though this was never a serious
1464     limitation, I suspect). However, there is a downside: pcre_compile() now
1465     runs more slowly than before (30% or more, depending on the pattern). I
1466     hope this isn't a big issue. There is no effect on runtime performance.
1468     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1469     newline (only possible for the last line of a file) and it was a
1470     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1472     19. Added additional timing features to pcretest. (1) The -tm option now times
1473     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1474     separate command line item, by a number that specifies the number of
1475     repeats to use when timing. The default is 50000; this gives better
1476     precision, but takes uncomfortably long for very large patterns.
1478     20. Extended pcre_study() to be more clever in cases where a branch of a
1479     subpattern has no definite first character. For example, (a*|b*)[cd] would
1480     previously give no result from pcre_study(). Now it recognizes that the
1481     first character must be a, b, c, or d.
1483     21. There was an incorrect error "recursive call could loop indefinitely" if
1484     a subpattern (or the entire pattern) that was being tested for matching an
1485     empty string contained only one non-empty item after a nested subpattern.
1486     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1487     incorrectly, because the \d was being skipped in the check.
1489     22. The pcretest program now has a new pattern option /B and a command line
1490     option -b, which is equivalent to adding /B to every pattern. This causes
1491     it to show the compiled bytecode, without the additional information that
1492     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1493     is the same as /B/I).
1495     23. A new optimization is now able automatically to treat some sequences such
1496     as a*b as a*+b. More specifically, if something simple (such as a character
1497     or a simple class like \d) has an unlimited quantifier, and is followed by
1498     something that cannot possibly match the quantified thing, the quantifier
1499     is automatically "possessified".
1501     24. A recursive reference to a subpattern whose number was greater than 39
1502     went wrong under certain circumstances in UTF-8 mode. This bug could also
1503     have affected the operation of pcre_study().
1505     25. Realized that a little bit of performance could be had by replacing
1506     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1508     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1510     27. Possessive quantifiers such as a++ were previously implemented by turning
1511     them into atomic groups such as ($>a+). Now they have their own opcodes,
1512     which improves performance. This includes the automatically created ones
1513     from 23 above.
1515     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1516     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1517     the first matched character to be a colon. This applied both to named and
1518     numbered groups.
1520     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1522     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1523     building PCRE on Windows easier, so I have included it in the distribution.
1525     31. There is now a check in pcretest against a ridiculously large number being
1526     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1527     loop, the loop is abandoned.
1529     32. Forward references to subpatterns in conditions such as (?(2)...) where
1530     subpattern 2 is defined later cause pcre_compile() to search forwards in
1531     the pattern for the relevant set of parentheses. This search went wrong
1532     when there were unescaped parentheses in a character class, parentheses
1533     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1535     33. "Subroutine" calls and backreferences were previously restricted to
1536     referencing subpatterns earlier in the regex. This restriction has now
1537     been removed.
1539     34. Added a number of extra features that are going to be in Perl 5.10. On the
1540     whole, these are just syntactic alternatives for features that PCRE had
1541     previously implemented using the Python syntax or my own invention. The
1542     other formats are all retained for compatibility.
1544     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1545     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1546     also .NET compatible.
1548     (b) A recursion or subroutine call to a named group can now be defined as
1549     (?&name) as well as (?P>name).
1551     (c) A backreference to a named group can now be defined as \k<name> or
1552     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1553     5.10, are also .NET compatible.
1555     (d) A conditional reference to a named group can now use the syntax
1556     (?(<name>) or (?('name') as well as (?(name).
1558     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1559     groups (named and numbered) that are never evaluated inline, but can be
1560     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1561     is always false. There may be only one alternative in such a group.
1563     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1564     as the simple (?(R). The condition is true only if the most recent
1565     recursion is that of the given number or name. It does not search out
1566     through the entire recursion stack.
1568     (g) The escape \gN or \g{N} has been added, where N is a positive or
1569     negative number, specifying an absolute or relative reference.
1571     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1572     some "unreachable code" warnings.
1574     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1575     things, this adds five new scripts.
1577     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1578     There were also incompatibilities regarding the handling of \Q..\E inside
1579     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1580     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1582     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1583     matches an empty string, and forcibly breaks the loop. There were bugs in
1584     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1585     against aaaa the result was just "a" rather than "aaaa", for example. Two
1586     separate and independent bugs (that affected different cases) have been
1587     fixed.
1589     39. Refactored the code to abolish the use of different opcodes for small
1590     capturing bracket numbers. This is a tidy that I avoided doing when I
1591     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1592     The new approach is not only tidier, it makes it possible to reduce the
1593     memory needed to fix the previous bug (38).
1595     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1596     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1597     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1598     mode.
1600     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1601     report.
1603     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1604     copy construction and assignment in the C++ wrapper.
1606     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1607     couple of bugs that could have given wrong results in the "--newline=crlf"
1608     case.
1610     44. Added a number of casts and did some reorganization of signed/unsigned int
1611     variables following suggestions from Dair Grant. Also renamed the variable
1612     "this" as "item" because it is a C++ keyword.
1614     45. Arranged for dftables to add
1616     #include "pcre_internal.h"
1618     to pcre_chartables.c because without it, gcc 4.x may remove the array
1619     definition from the final binary if PCRE is built into a static library and
1620     dead code stripping is activated.
1622     46. For an unanchored pattern, if a match attempt fails at the start of a
1623     newline sequence, and the newline setting is CRLF or ANY, and the next two
1624     characters are CRLF, advance by two characters instead of one.
1627 nigel 91 Version 6.7 04-Jul-06
1628     ---------------------
1630     1. In order to handle tests when input lines are enormously long, pcretest has
1631     been re-factored so that it automatically extends its buffers when
1632     necessary. The code is crude, but this _is_ just a test program. The
1633     default size has been increased from 32K to 50K.
1635     2. The code in pcre_study() was using the value of the re argument before
1636     testing it for NULL. (Of course, in any sensible call of the function, it
1637     won't be NULL.)
1639     3. The memmove() emulation function in pcre_internal.h, which is used on
1640     systems that lack both memmove() and bcopy() - that is, hardly ever -
1641     was missing a "static" storage class specifier.
1643     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1644     containing an extended class (one that cannot be represented by a bitmap
1645     because it contains high-valued characters or Unicode property items, e.g.
1646     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1647     pattern, but PCRE should not loop if you do not (it no longer does).
1648     [Detail: two cases were found: (a) a repeated subpattern containing an
1649     extended class; (b) a recursive reference to a subpattern that followed a
1650     previous extended class. It wasn't skipping over the extended class
1651     correctly when UTF-8 mode was not set.]
1653     5. A negated single-character class was not being recognized as fixed-length
1654     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1655     compile error "lookbehind assertion is not fixed length".
1657     6. The RunPerlTest auxiliary script was showing an unexpected difference
1658     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1659     write a Perl script that can interpret lines of an input file either as
1660     byte characters or as UTF-8, which is what "perltest" was being required to
1661     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1662     can't do is switch easily at run time between having the "use utf8;" pragma
1663     or not. In the end, I fudged it by using the RunPerlTest script to insert
1664     "use utf8;" explicitly for the UTF-8 tests.
1666     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1667     the end of the subject string, contrary to the documentation and to what
1668     Perl does. This was true of both matching functions. Now it matches only at
1669     the start of the subject and immediately after *internal* newlines.
1671     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1672     a pointer to an int instead of a pointer to an unsigned long int. This
1673     caused problems on 64-bit systems.
1675     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1676     instance of the 'standard' template library not being so standard".
1678     10. There was no check on the number of named subpatterns nor the maximum
1679     length of a subpattern name. The product of these values is used to compute
1680     the size of the memory block for a compiled pattern. By supplying a very
1681     long subpattern name and a large number of named subpatterns, the size
1682     computation could be caused to overflow. This is now prevented by limiting
1683     the length of names to 32 characters, and the number of named subpatterns
1684     to 10,000.
1686     11. Subpatterns that are repeated with specific counts have to be replicated in
1687     the compiled pattern. The size of memory for this was computed from the
1688     length of the subpattern and the repeat count. The latter is limited to
1689     65535, but there was no limit on the former, meaning that integer overflow
1690     could in principle occur. The compiled length of a repeated subpattern is
1691     now limited to 30,000 bytes in order to prevent this.
1693     12. Added the optional facility to have named substrings with the same name.
1695     13. Added the ability to use a named substring as a condition, using the
1696     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1697     are numbers (not recommended). Forward references are permitted.
1699     14. Added forward references in named backreferences (if you see what I mean).
1701     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1702     pattern could run off the end of the subject. For example, the pattern
1703     "(?s)(.{1,5})"8 did this with the subject "ab".
1705     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1706     PCRE_CASELESS was set when matching characters that were quantified with ?
1707     or *.
1709     17. A character class other than a single negated character that had a minimum
1710     but no maximum quantifier - for example [ab]{6,} - was not handled
1711     correctly by pce_dfa_exec(). It would match only one character.
1713     18. A valid (though odd) pattern that looked like a POSIX character
1714     class but used an invalid character after [ (for example [[,abc,]]) caused
1715     pcre_compile() to give the error "Failed: internal error: code overflow" or
1716     in some cases to crash with a glibc free() error. This could even happen if
1717     the pattern terminated after [[ but there just happened to be a sequence of
1718     letters, a binary zero, and a closing ] in the memory that followed.
1720     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1721     over the years. Originally (before any Unicode support), just the bottom 8
1722     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1723     output from "man perlunicode" includes this:
1725     The regular expression compiler produces polymorphic opcodes. That
1726     is, the pattern adapts to the data and automatically switches to
1727     the Unicode character scheme when presented with Unicode data--or
1728     instead uses a traditional byte scheme when presented with byte
1729     data.
1731     Sadly, a wide octal escape does not cause a switch, and in a string with
1732     no other multibyte characters, these octal escapes are treated as before.
1733     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1734     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1735     Unicode string.
1737     I have not perpetrated such confusion in PCRE. Up till now, it took just
1738     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1739     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1740     translate to the appropriate multibyte character.
1742     29. Applied some refactoring to reduce the number of warnings from Microsoft
1743     and Borland compilers. This has included removing the fudge introduced
1744     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1745     a warning about an unused variable.
1747     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1748     characters since release 4.0, because Perl (from release 5.004) does not.
1749     [Or at least, is documented not to: some releases seem to be in conflict
1750     with the documentation.] However, when a pattern was studied with
1751     pcre_study() and all its branches started with \s, PCRE still included VT
1752     as a possible starting character. Of course, this did no harm; it just
1753     caused an unnecessary match attempt.
1755     22. Removed a now-redundant internal flag bit that recorded the fact that case
1756     dependency changed within the pattern. This was once needed for "required
1757     byte" processing, but is no longer used. This recovers a now-scarce options
1758     bit. Also moved the least significant internal flag bit to the most-
1759     significant bit of the word, which was not previously used (hangover from
1760     the days when it was an int rather than a uint) to free up another bit for
1761     the future.
1763     23. Added support for CRLF line endings as well as CR and LF. As well as the
1764     default being selectable at build time, it can now be changed at runtime
1765     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1766     specify that it is scanning data with non-default line endings.
1768     24. Changed the definition of CXXLINK to make it agree with the definition of
1769     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1771     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1772     recursions. This makes a big different to stack usage for some patterns.
1774     26. If a subpattern containing a named recursion or subroutine reference such
1775     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1776     the space required for the compiled pattern went wrong and gave too small a
1777     value. Depending on the environment, this could lead to "Failed: internal
1778     error: code overflow at offset 49" or "glibc detected double free or
1779     corruption" errors.
1781     27. Applied patches from Google (a) to support the new newline modes and (b) to
1782     advance over multibyte UTF-8 characters in GlobalReplace.
1784     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1785     difference for some implementation of PCRE in some Windows version.
1787     29. Added some extra testing facilities to pcretest:
1789     \q<number> in a data line sets the "match limit" value
1790     \Q<number> in a data line sets the "match recursion limt" value
1791     -S <number> sets the stack size, where <number> is in megabytes
1793     The -S option isn't available for Windows.
1796 nigel 89 Version 6.6 06-Feb-06
1797     ---------------------
1799     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1800     in pcreposix.h. I have copied the definition from pcre.h.
1802     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1803     because pcre.h is no longer a built file.
1805     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1806     not normally included in the compiled code.
1809 nigel 87 Version 6.5 01-Feb-06
1810     ---------------------
1812     1. When using the partial match feature with pcre_dfa_exec(), it was not
1813     anchoring the second and subsequent partial matches at the new starting
1814     point. This could lead to incorrect results. For example, with the pattern
1815     /1234/, partially matching against "123" and then "a4" gave a match.
1817     2. Changes to pcregrep:
1819     (a) All non-match returns from pcre_exec() were being treated as failures
1820     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1821     error message is output. Some extra information is given for the
1823     probably the only errors that are likely to be caused by users (by
1824     specifying a regex that has nested indefinite repeats, for instance).
1825     If there are more than 20 of these errors, pcregrep is abandoned.
1827     (b) A binary zero was treated as data while matching, but terminated the
1828     output line if it was written out. This has been fixed: binary zeroes
1829     are now no different to any other data bytes.
1831     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1832     used to set a locale for matching. The --locale=xxxx long option has
1833     been added (no short equivalent) to specify a locale explicitly on the
1834     pcregrep command, overriding the environment variables.
1836     (d) When -B was used with -n, some line numbers in the output were one less
1837     than they should have been.
1839     (e) Added the -o (--only-matching) option.
1841     (f) If -A or -C was used with -c (count only), some lines of context were
1842     accidentally printed for the final match.
1844     (g) Added the -H (--with-filename) option.
1846     (h) The combination of options -rh failed to suppress file names for files
1847     that were found from directory arguments.
1849     (i) Added the -D (--devices) and -d (--directories) options.
1851     (j) Added the -F (--fixed-strings) option.
1853     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1855     (l) Added the --colo(u)r option.
1857     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1858     is not present by default.
1860     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1861     items such as (?R) or (?1), when the recursion could match a number of
1862     alternatives. If it matched one of the alternatives, but subsequently,
1863     outside the recursion, there was a failure, the code tried to back up into
1864     the recursion. However, because of the way PCRE is implemented, this is not
1865     possible, and the result was an incorrect result from the match.
1867     In order to prevent this happening, the specification of recursion has
1868     been changed so that all such subpatterns are automatically treated as
1869     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1871     4. I had overlooked the fact that, in some locales, there are characters for
1872     which isalpha() is true but neither isupper() nor islower() are true. In
1873     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1874     and ordfeminine) are like this. This affected the treatment of \w and \W
1875     when they appeared in character classes, but not when they appeared outside
1876     a character class. The bit map for "word" characters is now created
1877     separately from the results of isalnum() instead of just taking it from the
1878     upper, lower, and digit maps. (Plus the underscore character, of course.)
1880     5. The above bug also affected the handling of POSIX character classes such as
1881     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1882     permanent tables. Instead, the bit maps for such a class were previously
1883     created as the appropriate unions of the upper, lower, and digit bitmaps.
1884     Now they are created by subtraction from the [[:word:]] class, which has
1885     its own bitmap.
1887     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1888     It is created by subtracting the vertical space characters (\x09, \x0a,
1889     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1890     subtraction was done in the overall bitmap for a character class, meaning
1891     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1892     be recognized. This bug has been fixed.
1894     7. Patches from the folks at Google:
1896     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1897     real life, but is still worth protecting against".
1899     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1900     regular expressions".
1902     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1903     have it.
1905     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1906     "configure" and the latter not, in order to fix a problem somebody had
1907     with compiling the Arg class on HP-UX.
1909     (e) Improve the error-handling of the C++ wrapper a little bit.
1911     (f) New tests for checking recursion limiting.
1913     8. The pcre_memmove() function, which is used only if the environment does not
1914     have a standard memmove() function (and is therefore rarely compiled),
1915     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1916     returning a result (though PCRE never actually uses the result).
1918     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1919     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1920     returned instead of calling malloc() with an overflowing number that would
1921     most likely cause subsequent chaos.
1923     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1925     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1926     with this option is matched, the nmatch and pmatch options of regexec() are
1927     ignored.
1929     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1930     provided in case anyone wants to the the POSIX interface with UTF-8
1931     strings.
1933     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1934     C++ linking (needed for some HP-UX environments).
1936     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1937     (unused parameter) and in the pcre_printint() function (omitted "default"
1938     switch label when the default is to do nothing).
1940     15. Added some code to make it possible, when PCRE is compiled as a C++
1941     library, to replace subject pointers for pcre_exec() with a smart pointer
1942     class, thus making it possible to process discontinuous strings.
1944     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1945     much the same function. They were added by different people who were trying
1946     to make PCRE easy to compile on non-Unix systems. It has been suggested
1947     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1948     for compiling on Windows systems. I have therefore replaced it with
1949     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1950     defaults to "extern" for C or "extern C" for C++, which works fine on
1951     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1952     SCOPE with something explicit in config.h. In addition:
1954     (a) pcreposix.h still had just "extern" instead of either of these macros;
1955     I have replaced it with PCRE_DATA_SCOPE.
1957     (b) Functions such as _pcre_xclass(), which are internal to the library,
1958     but external in the C sense, all had PCRE_EXPORT in their definitions.
1959     This is apparently wrong for the Windows case, so I have removed it.
1960     (It makes no difference on Unix-like systems.)
1962     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1963     of recursive calls to match(). This is different to MATCH_LIMIT because
1964     that limits the total number of calls to match(), not all of which increase
1965     the depth of recursion. Limiting the recursion depth limits the amount of
1966     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1967     when PCRE is compiled, and changed at run time. A patch from Google adds
1968     this functionality to the C++ interface.
1970     18. Changes to the handling of Unicode character properties:
1972     (a) Updated the table to Unicode 4.1.0.
1974     (b) Recognize characters that are not in the table as "Cn" (undefined).
1976     (c) I revised the way the table is implemented to a much improved format
1977     which includes recognition of ranges. It now supports the ranges that
1978     are defined in UnicodeData.txt, and it also amalgamates other
1979     characters into ranges. This has reduced the number of entries in the
1980     table from around 16,000 to around 3,000, thus reducing its size
1981     considerably. I realized I did not need to use a tree structure after
1982     all - a binary chop search is just as efficient. Having reduced the
1983     number of entries, I extended their size from 6 bytes to 8 bytes to
1984     allow for more data.
1986     (d) Added support for Unicode script names via properties such as \p{Han}.
1988     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1989     matching that character.
1991     20. When matching a repeated Unicode property with a minimum greater than zero,
1992     (for example \pL{2,}), PCRE could look past the end of the subject if it
1993     reached it while seeking the minimum number of characters. This could
1994     happen only if some of the characters were more than one byte long, because
1995     there is a check for at least the minimum number of bytes.
1997     21. Refactored the implementation of \p and \P so as to be more general, to
1998     allow for more different types of property in future. This has changed the
1999     compiled form incompatibly. Anybody with saved compiled patterns that use
2000     \p or \P will have to recompile them.
2002     22. Added "Any" and "L&" to the supported property types.
2004     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2005     but give a compile time error if the value is greater than 0xff.
2007     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2008     accidentally not being installed or uninstalled.
2010     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2011     made were to insert the current release number. This seemed silly, because
2012     it made things harder for people building PCRE on systems that don't run
2013     "configure". I have turned pcre.h into a distributed file, no longer built
2014     by "configure", with the version identification directly included. There is
2015     no longer a pcre.h.in file.
2017     However, this change necessitated a change to the pcre-config script as
2018     well. It is built from pcre-config.in, and one of the substitutions was the
2019     release number. I have updated configure.ac so that ./configure now finds
2020     the release number by grepping pcre.h.
2022     26. Added the ability to run the tests under valgrind.
2025 nigel 85 Version 6.4 05-Sep-05
2026     ---------------------
2028     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2029     "--" to be printed when multiple files were scanned, even when none of the
2030     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2031     consider it to be a bug, and have restored the previous behaviour.
2033     2. A couple of code tidies to get rid of compiler warnings.
2035     3. The pcretest program used to cheat by referring to symbols in the library
2036     whose names begin with _pcre_. These are internal symbols that are not
2037     really supposed to be visible externally, and in some environments it is
2038     possible to suppress them. The cheating is now confined to including
2039     certain files from the library's source, which is a bit cleaner.
2041     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2042     file's purpose clearer.
2044     5. Reorganized pcre_ucp_findchar().
2047 nigel 83 Version 6.3 15-Aug-05
2048     ---------------------
2050     1. The file libpcre.pc.in did not have general read permission in the tarball.
2052     2. There were some problems when building without C++ support:
2054     (a) If C++ support was not built, "make install" and "make test" still
2055     tried to test it.
2057     (b) There were problems when the value of CXX was explicitly set. Some
2058     changes have been made to try to fix these, and ...
2060     (c) --disable-cpp can now be used to explicitly disable C++ support.
2062     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2063     backslash in a target when C++ was disabled. This confuses some
2064     versions of "make", apparently. Using an intermediate variable solves
2065     this. (Same for CPP_LOBJ.)
2067     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2068     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2069     necessary on certain architectures.
2071     4. Added a setting of -export-symbols-regex to the link command to remove
2072     those symbols that are exported in the C sense, but actually are local
2073     within the library, and not documented. Their names all begin with
2074     "_pcre_". This is not a perfect job, because (a) we have to except some
2075     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2076     available (and never for static libraries). I have made a note to try to
2077     find a way round (a) in the future.
2080 nigel 81 Version 6.2 01-Aug-05
2081     ---------------------
2083     1. There was no test for integer overflow of quantifier values. A construction
2084     such as {1111111111111111} would give undefined results. What is worse, if
2085     a minimum quantifier for a parenthesized subpattern overflowed and became
2086     negative, the calculation of the memory size went wrong. This could have
2087     led to memory overwriting.
2089     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2091     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2092     operating environments where this matters.
2094     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2095     PCRE options from within the C++ wrapper.
2097     5. Named capturing subpatterns were not being correctly counted when a pattern
2098     was compiled. This caused two problems: (a) If there were more than 100
2099     such subpatterns, the calculation of the memory needed for the whole
2100     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2101     back references of the form \12, where the number was greater than 9, were
2102     not recognized as back references, even though there were sufficient
2103     previous subpatterns.
2105     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2106     versions of gcc, e.g. 2.95.4.
2109 nigel 79 Version 6.1 21-Jun-05
2110     ---------------------
2112     1. There was one reference to the variable "posix" in pcretest.c that was not
2113     surrounded by "#if !defined NOPOSIX".
2115     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2116     the cross-check on the old pcre_info() function, for the benefit of the
2117     cut-down version of PCRE that is currently imported into Exim.
2119     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2120     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2121     patterns that start (?i) but I don't think that matters. The use of (?i) is
2122     just an example; this all applies to the other options as well.
2124     4. Since libtool seems to echo the compile commands it is issuing, the output
2125     from "make" can be reduced a bit by putting "@" in front of each libtool
2126     compile command.
2128     5. Patch from the folks at Google for configure.in to be a bit more thorough
2129     in checking for a suitable C++ installation before trying to compile the
2130     C++ stuff. This should fix a reported problem when a compiler was present,
2131     but no suitable headers.
2133     6. The man pages all had just "PCRE" as their title. I have changed them to
2134     be the relevant file name. I have also arranged that these names are
2135     retained in the file doc/pcre.txt, which is a concatenation in text format
2136     of all the man pages except the little individual ones for each function.
2138     7. The NON-UNIX-USE file had not been updated for the different set of source
2139     files that come with release 6. I also added a few comments about the C++
2140     wrapper.
2143 nigel 77 Version 6.0 07-Jun-05
2144     ---------------------
2146     1. Some minor internal re-organization to help with my DFA experiments.
2148     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2149     didn't matter for the library itself when fully configured, but did matter
2150     when compiling without UCP support, or within Exim, where the ucp files are
2151     not imported.
2153     3. Refactoring of the library code to split up the various functions into
2154     different source modules. The addition of the new DFA matching code (see
2155     below) to a single monolithic source would have made it really too
2156     unwieldy, quite apart from causing all the code to be include in a
2157     statically linked application, when only some functions are used. This is
2158     relevant even without the DFA addition now that patterns can be compiled in
2159     one application and matched in another.
2161     The downside of splitting up is that there have to be some external
2162     functions and data tables that are used internally in different modules of
2163     the library but which are not part of the API. These have all had their
2164     names changed to start with "_pcre_" so that they are unlikely to clash
2165     with other external names.
2167     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2168     a different (DFA) algorithm. Although it is slower than the original
2169     function, it does have some advantages for certain types of matching
2170     problem.
2172     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2173     including restarting after a partial match.
2175     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2176     defined when compiling for Windows was sent to me. I have put it into the
2177     code, though I have no means of testing or verifying it.
2179     7. Added the pcre_refcount() auxiliary function.
2181     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2182     match before or at the first newline in the subject string. In pcretest,
2183     the /f option on a pattern can be used to set this.
2185     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2186     would behave wrongly. This has been present in PCRE since release 4.0.
2188     10. A number of changes to the pcregrep command:
2190     (a) Refactored how -x works; insert ^(...)$ instead of setting
2191     PCRE_ANCHORED and checking the length, in preparation for adding
2192     something similar for -w.
2194     (b) Added the -w (match as a word) option.
2196     (c) Refactored the way lines are read and buffered so as to have more
2197     than one at a time available.
2199     (d) Implemented a pcregrep test script.
2201     (e) Added the -M (multiline match) option. This allows patterns to match
2202     over several lines of the subject. The buffering ensures that at least
2203     8K, or the rest of the document (whichever is the shorter) is available
2204     for matching (and similarly the previous 8K for lookbehind assertions).
2206     (f) Changed the --help output so that it now says
2208     -w, --word-regex(p)
2210     instead of two lines, one with "regex" and the other with "regexp"
2211     because that confused at least one person since the short forms are the
2212     same. (This required a bit of code, as the output is generated
2213     automatically from a table. It wasn't just a text change.)
2215     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2216     option but starts with a hyphen. Could be a pattern or a path name
2217     starting with a hyphen, for instance.
2219     (h) "-" can be given as a file name to represent stdin.
2221     (i) When file names are being printed, "(standard input)" is used for
2222     the standard input, for compatibility with GNU grep. Previously
2223     "<stdin>" was used.
2225     (j) The option --label=xxx can be used to supply a name to be used for
2226     stdin when file names are being printed. There is no short form.
2228     (k) Re-factored the options decoding logic because we are going to add
2229     two more options that take data. Such options can now be given in four
2230     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2232     (l) Added the -A, -B, and -C options for requesting that lines of context
2233     around matches be printed.
2235     (m) Added the -L option to print the names of files that do not contain
2236     any matching lines, that is, the complement of -l.
2238     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2239     continue to scan other files.
2241     (o) The -s option was incorrectly implemented. For compatibility with other
2242     greps, it now suppresses the error message for a non-existent or non-
2243     accessible file (but not the return code). There is a new option called
2244     -q that suppresses the output of matching lines, which was what -s was
2245     previously doing.
2247     (p) Added --include and --exclude options to specify files for inclusion
2248     and exclusion when recursing.
2250     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2251     Hopefully, it now does.
2253     12. Missing cast in pcre_study().
2255     13. Added an "uninstall" target to the makefile.
2257     14. Replaced "extern" in the function prototypes in Makefile.in with
2258     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2259     world, but is set differently for Windows.
2261     15. Added a second compiling function called pcre_compile2(). The only
2262     difference is that it has an extra argument, which is a pointer to an
2263     integer error code. When there is a compile-time failure, this is set
2264     non-zero, in addition to the error test pointer being set to point to an
2265     error message. The new argument may be NULL if no error number is required
2266     (but then you may as well call pcre_compile(), which is now just a
2267     wrapper). This facility is provided because some applications need a
2268     numeric error indication, but it has also enabled me to tidy up the way
2269     compile-time errors are handled in the POSIX wrapper.
2271     16. Added VPATH=.libs to the makefile; this should help when building with one
2272     prefix path and installing with another. (Or so I'm told by someone who
2273     knows more about this stuff than I do.)
2275     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2276     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2277     match everything, including newlines. This is not POSIX-compatible, but
2278     somebody wanted the feature. From pcretest it can be activated by using
2279     both the P and the s flags.
2281     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2283     19. libpcre.pc was being incorrectly installed as executable.
2285     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2286     it now also looks for '\r' so that it will work unmodified on Windows.
2288     21. Added Google's contributed C++ wrapper to the distribution.
2290     22. Added some untidy missing memory free() calls in pcretest, to keep
2291     Electric Fence happy when testing.
2295 nigel 75 Version 5.0 13-Sep-04
2296     ---------------------
2298     1. Internal change: literal characters are no longer packed up into items
2299     containing multiple characters in a single byte-string. Each character
2300     is now matched using a separate opcode. However, there may be more than one
2301     byte in the character in UTF-8 mode.
2303     2. The pcre_callout_block structure has two new fields: pattern_position and
2304     next_item_length. These contain the offset in the pattern to the next match
2305     item, and its length, respectively.
2307     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2308     insertion of callouts before each pattern item. Added the /C option to
2309     pcretest to make use of this.
2311     4. On the advice of a Windows user, the lines
2313     #if defined(_WIN32) || defined(WIN32)
2314     _setmode( _fileno( stdout ), 0x8000 );
2315     #endif /* defined(_WIN32) || defined(WIN32) */
2317     have been added to the source of pcretest. This apparently does useful
2318     magic in relation to line terminators.
2320     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2321     for the benefit of those environments where the "b" makes a difference.
2323     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2324     to know about it. I have put a hack into configure.in that adds in code
2325     to set GCC=yes if CC=icc. This seems to end up at a point in the
2326     generated configure script that is early enough to affect the setting of
2327     compiler options, which is what is needed, but I have no means of testing
2328     whether it really works. (The user who reported this had patched the
2329     generated configure script, which of course I cannot do.)
2331     LATER: After change 22 below (new libtool files), the configure script
2332     seems to know about icc (and also ecc). Therefore, I have commented out
2333     this hack in configure.in.
2335     7. Added support for pkg-config (2 patches were sent in).
2337     8. Negated POSIX character classes that used a combination of internal tables
2338     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2339     [[:^ascii]]. Typically, they would match almost any characters. The other
2340     POSIX classes were not broken in this way.
2342     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2343     to find the match, as PCRE was deluded into thinking that the match had to
2344     start at the start point or following a newline. The same bug applied to
2345     patterns with negative forward assertions or any backward assertions
2346     preceding ".*" at the start, unless the pattern required a fixed first
2347     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2349     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2350     starting at the last subject character, bytes beyond the end of the subject
2351     string were read.
2353     11. Renamed the variable "class" as "classbits" to make life easier for C++
2354     users. (Previously there was a macro definition, but it apparently wasn't
2355     enough.)
2357     12. Added the new field "tables" to the extra data so that tables can be passed
2358     in at exec time, or the internal tables can be re-selected. This allows
2359     a compiled regex to be saved and re-used at a later time by a different
2360     program that might have everything at different addresses.
2362     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2363     -R library as well as a -L library.
2365     14. The debugging options of pcretest (-d on the command line or D on a
2366     pattern) showed incorrect output for anything following an extended class
2367     that contained multibyte characters and which was followed by a quantifier.
2369     15. Added optional support for general category Unicode character properties
2370     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2371     support. It adds about 90K to the size of the library. The meanings of the
2372     inbuilt class escapes such as \d and \s have NOT been changed.
2374     16. Updated pcredemo.c to include calls to free() to release the memory for the
2375     compiled pattern.
2377     17. The generated file chartables.c was being created in the source directory
2378     instead of in the building directory. This caused the build to fail if the
2379     source directory was different from the building directory, and was
2380     read-only.
2382     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2383     file. No doubt somebody will tell me if they don't make sense... Also added
2384     Dan Mooney's comments about building on OpenVMS.
2386     19. Added support for partial matching via the PCRE_PARTIAL option for
2387     pcre_exec() and the \P data escape in pcretest.
2389     20. Extended pcretest with 3 new pattern features:
2391     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2392     write the compiled pattern to the file whose name is "rest-of-line".
2393     This is a straight binary dump of the data, with the saved pointer to
2394     the character tables forced to be NULL. The study data, if any, is
2395     written too. After writing, pcretest reads a new pattern.
2397     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2398     compiled pattern from the given file. There must not be any
2399     occurrences of "<" in the file name (pretty unlikely); if there are,
2400     pcretest will instead treat the initial "<" as a pattern delimiter.
2401     After reading in the pattern, pcretest goes on to read data lines as
2402     usual.
2404     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2405     and 16-bit fields in a compiled pattern, to simulate a pattern that
2406     was compiled on a host of opposite endianness.
2408     21. The pcre-exec() function can now cope with patterns that were compiled on
2409     hosts of opposite endianness, with this restriction:
2411     As for any compiled expression that is saved and used later, the tables
2412     pointer field cannot be preserved; the extra_data field in the arguments
2413     to pcre_exec() should be used to pass in a tables address if a value
2414     other than the default internal tables were used at compile time.
2416     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2417     now diagnosed as an error. Previously, most of the time, a negative number
2418     would have been treated as zero, but if in addition "ovector" was passed as
2419     NULL, a crash could occur.
2421     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2422     new versions from the libtool 1.5 distribution (the last one is a copy of
2423     a file called libtool.m4). This seems to have fixed the need to patch
2424     "configure" to support Darwin 1.3 (which I used to do). However, I still
2425     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2426     workstation).
2428     24. Changed the PCRE licence to be the more standard "BSD" licence.
2431 nigel 73 Version 4.5 01-Dec-03
2432     ---------------------
2434     1. There has been some re-arrangement of the code for the match() function so
2435     that it can be compiled in a version that does not call itself recursively.
2436     Instead, it keeps those local variables that need separate instances for
2437     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2438     needs to "recurse". Keeping track of where control must go is done by means
2439     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2440     hide most of the details from the main code, and operates only if
2441     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2442     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2443     operating.
2445     To make it easier for callers to provide specially tailored get/free
2446     functions for this usage, two new functions, pcre_stack_malloc, and
2447     pcre_stack_free, are used. They are always called in strict stacking order,
2448     and the size of block requested is always the same.
2450     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2451     PCRE has been compiled to use the stack or the heap for recursion. The
2452     -C option of pcretest uses this to show which version is compiled.
2454     A new data escape \S, is added to pcretest; it causes the amounts of store
2455     obtained and freed by both kinds of malloc/free at match time to be added
2456     to the output.
2458     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2459     what's available on my current Linux desktop machine.
2461     3. When matching a UTF-8 string, the test for a valid string at the start has
2462     been extended. If start_offset is not zero, PCRE now checks that it points
2463     to a byte that is the start of a UTF-8 character. If not, it returns
2464     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2465     this is necessary because there may be backward assertions in the pattern.
2466     When matching the same subject several times, it may save resources to use
2467     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2469     4. The code for checking the validity of UTF-8 strings has been tightened so
2470     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2471     containing "overlong sequences".
2473     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2474     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2475     should have been "&", but it just so happened that all the cases this let
2476     through by mistake were picked up later in the function.
2478     6. I had used a variable called "isblank" - this is a C99 function, causing
2479     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2481     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2482     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2483     so the version is shown; (c) stop "make test" echoing "./RunTest".
2485     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2487     9. The prototype for memmove() for systems that don't have it was using
2488     size_t, but the inclusion of the header that defines size_t was later. I've
2489     moved the #includes for the C headers earlier to avoid this.
2491     10. Added some adjustments to the code to make it easier to compiler on certain
2492     special systems:
2494     (a) Some "const" qualifiers were missing.
2495     (b) Added the macro EXPORT before all exported functions; by default this
2496     is defined to be empty.
2497     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2498     that it reads its output file name as an argument instead of writing
2499     to the standard output and assuming this can be redirected.
2501     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2502     class containing characters with values greater than 255, PCRE compilation
2503     went into a loop.
2505     12. A recursive reference to a subpattern that was within another subpattern
2506     that had a minimum quantifier of zero caused PCRE to crash. For example,
2507     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2508     recursion. If the recursively-called subpattern itself had a zero repeat,
2509     that was OK.
2511     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2512     buffer into which it was copied (for escape processing) was still set at
2513     1024, so long lines caused crashes.
2515     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2516     "internal error: code overflow...". This applied to any character class
2517     that was followed by a possessive quantifier.
2519     15. Modified the Makefile to add libpcre.la as a prerequisite for
2520     libpcreposix.la because I was told this is needed for a parallel build to
2521     work.
2523     16. If a pattern that contained .* following optional items at the start was
2524     studied, the wrong optimizing data was generated, leading to matching
2525     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2526     matching string must start with a or b or c. The correct conclusion for
2527     this pattern is that a match can start with any character.
2530 nigel 71 Version 4.4 13-Aug-03
2531     ---------------------
2533     1. In UTF-8 mode, a character class containing characters with values between
2534     127 and 255 was not handled correctly if the compiled pattern was studied.
2535     In fixing this, I have also improved the studying algorithm for such
2536     classes (slightly).
2538     2. Three internal functions had redundant arguments passed to them. Removal
2539     might give a very teeny performance improvement.
2541     3. Documentation bug: the value of the capture_top field in a callout is *one
2542     more than* the number of the hightest numbered captured substring.
2544     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2545     in incorrectly linking with a previously installed version. They now link
2546     explicitly with libpcre.la.
2548     5. configure.in no longer needs to recognize Cygwin specially.
2550     6. A problem in pcre.in for Windows platforms is fixed.
2552     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2553     pcretest, it used to include the size of the study block as part of its
2554     output. Unfortunately, the structure contains a field that has a different
2555     size on different hardware architectures. This meant that the tests that
2556     showed this size failed. As the block is currently always of a fixed size,
2557     this information isn't actually particularly useful in pcretest output, so
2558     I have just removed it.
2560     8. Three pre-processor statements accidentally did not start in column 1.
2561     Sadly, there are *still* compilers around that complain, even though
2562     standard C has not required this for well over a decade. Sigh.
2564     9. In pcretest, the code for checking callouts passed small integers in the
2565     callout_data field, which is a void * field. However, some picky compilers
2566     complained about the casts involved for this on 64-bit systems. Now
2567     pcretest passes the address of the small integer instead, which should get
2568     rid of the warnings.
2570     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2571     both compile and run time, and gives an error if an invalid UTF-8 sequence
2572     is found. There is a option for disabling this check in cases where the
2573     string is known to be correct and/or the maximum performance is wanted.
2575     11. In response to a bug report, I changed one line in Makefile.in from
2577     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2578     to
2579     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2581     to look similar to other lines, but I have no way of telling whether this
2582     is the right thing to do, as I do not use Windows. No doubt I'll get told
2583     if it's wrong...
2586 nigel 69 Version 4.3 21-May-03
2587     ---------------------
2589     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2590     Makefile.
2592     2. Some refactoring to improve the quality of the code:
2594     (i) The utf8_table... variables are now declared "const".
2596     (ii) The code for \cx, which used the "case flipping" table to upper case
2597     lower case letters, now just substracts 32. This is ASCII-specific,
2598     but the whole concept of \cx is ASCII-specific, so it seems
2599     reasonable.
2601     (iii) PCRE was using its character types table to recognize decimal and
2602     hexadecimal digits in the pattern. This is silly, because it handles
2603     only 0-9, a-f, and A-F, but the character types table is locale-
2604     specific, which means strange things might happen. A private
2605     table is now used for this - though it costs 256 bytes, a table is
2606     much faster than multiple explicit tests. Of course, the standard
2607     character types table is still used for matching digits in subject
2608     strings against \d.
2610     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2611     ending in _t are). So I've renamed it as ESC_tee.
2613     3. The first argument for regexec() in the POSIX wrapper should have been
2614     defined as "const".
2616     4. Changed pcretest to use malloc() for its buffers so that they can be
2617     Electric Fenced for debugging.
2619     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2620     to read one or more bytes before the start of the subject string. Often this
2621     had no effect on PCRE's behaviour, but in some circumstances it could
2622     provoke a segmentation fault.
2624     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2625     to try to read one or more bytes before the start of the subject string.
2627     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2628     UTF-8 support could misbehave in various ways if the subject string
2629     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2630     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2631     back over UTF-8 characters.)
2634 nigel 67 Version 4.2 14-Apr-03
2635     ---------------------
2637     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2639     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2640     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2641     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2642     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2643     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2644     and BUILD_EXEEXT
2645     Note: automatic setting of the BUILD variables is not yet working
2646     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2647     compile-time but not at link-time
2648     [LINK]: use for linking executables only
2649     make different versions for Windows and non-Windows
2650     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2651     libraries
2652     [LINK_FOR_BUILD]: new variable
2653     [OBJEXT]: use throughout
2654     [EXEEXT]: use throughout
2655     <winshared>: new target
2656     <wininstall>: new target
2657     <dftables.o>: use native compiler
2658     <dftables>: use native linker
2659     <install>: handle Windows platform correctly
2660     <clean>: ditto
2661     <check>: ditto
2662     copy DLL to top builddir before testing
2664     As part of these changes, -no-undefined was removed again. This was reported
2665     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2666     in any case.
2668     3. Some tidies to get rid of compiler warnings:
2670     . In the match_data structure, match_limit was an unsigned long int, whereas
2671     match_call_count was an int. I've made them both unsigned long ints.
2673     . In pcretest the fact that a const uschar * doesn't automatically cast to
2674     a void * provoked a warning.
2676     . Turning on some more compiler warnings threw up some "shadow" variables
2677     and a few more missing casts.
2679     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2680     option, a class that contained a single character with a value between 128
2681     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2683     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2684     option, a class that contained several characters, but with at least one
2685     whose value was between 128 and 255 caused PCRE to crash.
2688 nigel 65 Version 4.1 12-Mar-03
2689     ---------------------
2690 nigel 63
2691 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2692     needed, and a string in dftables.c that was longer than standard compilers are
2693     required to support.
2695     2. Compiling with Sun's compiler found a few more places where the code could
2696     be tidied up in order to avoid warnings.
2698     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2699     first of these names is deprecated in the latest Autoconf in favour of the name
2700     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2701     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2702     analogy I have changed it to CFLAGS_FOR_BUILD.
2704     4. Added -no-undefined to the linking command in the Makefile, because this is
2705     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2706     linking step for the pcreposix library.
2708     5. PCRE was failing to diagnose the case of two named groups with the same
2709     name.
2711     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2712     literal character that is needed in the subject for a match, and scans along to
2713     ensure that it is present before embarking on the full matching process. This
2714     saves time in cases of nested unlimited repeats that are never going to match.
2715     Problem: the scan can take a lot of time if the subject is very long (e.g.
2716     megabytes), thus penalizing straightforward matches. It is now done only if the
2717     amount of subject to be scanned is less than 1000 bytes.
2719     7. A lesser problem with the same optimization is that it was recording the
2720     first character of an anchored pattern as "needed", thus provoking a search
2721     right along the subject, even when the first match of the pattern was going to
2722     fail. The "needed" character is now not set for anchored patterns, unless it
2723     follows something in the pattern that is of non-fixed length. Thus, it still
2724     fulfils its original purpose of finding quick non-matches in cases of nested
2725     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2728     Version 4.0 17-Feb-03
2729     ---------------------
2731 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2732     extended to the end of string, PCRE compiled incorrect data. This could lead to
2733     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2735     2. Moved to autoconf 2.53 and libtool 1.4.2.
2737     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2738     the special perltest8 script is no longer needed - all the tests can be run
2739     from a single perltest script.
2741     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2742     by \s. It has now been removed in PCRE. This means it isn't recognized as
2743     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2744     class [:space:] *does* include VT, thereby creating a mess.
2746     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2747     space and tab.
2749     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2750     its new features into the main test script, reducing the number of scripts.
2752     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2753     were backward compatible, and made the (?i) apply to the whole pattern, as if
2754     /i were given. Now it behaves more logically, and applies the option setting
2755     only to what follows. PCRE has been changed to follow suit. However, if it
2756     finds options settings right at the start of the pattern, it extracts them into
2757     the global options, as before. Thus, they show up in the info data.
2759     8. Added support for the \Q...\E escape sequence. Characters in between are
2760     treated as literals. This is slightly different from Perl in that $ and @ are
2761     also handled as literals inside the quotes. In Perl, they will cause variable
2762     interpolation. Note the following examples:
2764     Pattern PCRE matches Perl matches
2766     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2767     \Qabc\$xyz\E abc\$xyz abc\$xyz
2768     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2770     For compatibility with Perl, \Q...\E sequences are recognized inside character
2771     classes as well as outside them.
2773     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2774     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2775     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2776     signed/unsigned warnings.
2778     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2779     option for pcretest, so I've replaced it by a simple function that does just
2780     that job.
2782     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2783     "pcregrep -".
2785     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2786     Java package. This provides some syntactic sugar for simple cases of what my
2787     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2788     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2789     item, you can use this simplified notation. Note that only makes sense with
2790     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2791     greediness, whatever the setting of the PCRE_UNGREEDY option.
2793     13. A change of greediness default within a pattern was not taking effect at
2794     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2795     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2796     was abstracted outside.
2798     14. PCRE now supports the \G assertion. It is true when the current matching
2799     position is at the start point of the match. This differs from \A when the
2800     starting offset is non-zero. Used with the /g option of pcretest (or similar
2801     code), it works in the same way as it does for Perl's /g option. If all
2802     alternatives of a regex begin with \G, the expression is anchored to the start
2803     match position, and the "anchored" flag is set in the compiled expression.
2805     15. Some bugs concerning the handling of certain option changes within patterns
2806     have been fixed. These applied to options other than (?ims). For example,
2807     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2808     been the other way round. Some of this was related to change 7 above.
2810     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2811     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2812     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2813     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2815     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2816     mode. Unlike ".", it always matches newline, whatever the setting of
2817     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2818     assertions. Perl allows it, but it doesn't (in general) work because it can't
2819     calculate the length of the lookbehind. At least, that's the case for Perl
2820     5.8.0 - I've been told they are going to document that it doesn't work in
2821     future.
2823     18. Added an error diagnosis for escapes that PCRE does not support: these are
2824     \L, \l, \N, \P, \p, \U, \u, and \X.
2826     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2827     reading past the end of the pattern in cases such as /[abcd/.
2829     20. PCRE was getting more memory than necessary for patterns with classes that
2830     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2832     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2833     compiling PCRE for use with Virtual Pascal.
2835     22. Small fix to the Makefile to make it work properly if the build is done
2836     outside the source tree.
2838     23. Added a new extension: a condition to go with recursion. If a conditional
2839     subpattern starts with (?(R) the "true" branch is used if recursion has
2840     happened, whereas the "false" branch is used only at the top level.
2842     24. When there was a very long string of literal characters (over 255 bytes
2843     without UTF support, over 250 bytes with UTF support), the computation of how
2844     much memory was required could be incorrect, leading to segfaults or other
2845     strange effects.
2847     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2848     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2849     there was a subsequent back reference to those brackets. This meant that, for
2850     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2851     possible to check for precisely this case. All we can do is abandon the
2852     optimization if .* occurs inside capturing brackets when there are any back
2853     references whatsoever. (See below for a better fix that came later.)
2855     26. The handling of the optimization for finding the first character of a
2856     non-anchored pattern, and for finding a character that is required later in the
2857     match were failing in some cases. This didn't break the matching; it just
2858     failed to optimize when it could. The way this is done has been re-implemented.
2860     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2862     28. Added a new feature that provides some of the functionality that Perl
2863     provides with (?{...}). The facility is termed a "callout". The way it is done
2864     in PCRE is for the caller to provide an optional function, by setting
2865     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2866     global variable. By default it is unset, which disables all calling out. To get
2867     the function called, the regex must include (?C) at appropriate points. This
2868     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2869     This provides a means of identifying different callout points. When PCRE
2870     reaches such a point in the regex, if pcre_callout has been set, the external
2871     function is called. It is provided with data in a structure called
2872     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2873     matching continues; if it returns a non-zero value, the match at the current
2874     point fails. However, backtracking will occur if possible. [This was changed
2875     later and other features added - see item 49 below.]
2877     29. pcretest is upgraded to test the callout functionality. It provides a
2878     callout function that displays information. By default, it shows the start of
2879     the match and the current position in the text. There are some new data escapes
2880     to vary what happens:
2882     \C+ in addition, show current contents of captured substrings
2883     \C- do not supply a callout function
2884     \C!n return 1 when callout number n is reached
2885     \C!n!m return 1 when callout number n is reached for the mth time
2887     30. If pcregrep was called with the -l option and just a single file name, it
2888     output "<stdin>" if a match was found, instead of the file name.
2890     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2891     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2892     pcre_exec(). This saves a malloc/free per call. The default value of
2893     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2894     when configuring.
2896     32. The default maximum size of a compiled pattern is 64K. There have been a
2897     few cases of people hitting this limit. The code now uses macros to handle the
2898     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2899     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2900     configuring. Tests 2 and 5 work only with 2-byte links because they output
2901     debugging information about compiled patterns.
2903     33. Internal code re-arrangements:
2905     (a) Moved the debugging function for printing out a compiled regex into
2906     its own source file (printint.c) and used #include to pull it into
2907     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2908     separate copies.
2910     (b) Defined the list of op-code names for debugging as a macro in
2911     internal.h so that it is next to the definition of the opcodes.
2913     (c) Defined a table of op-code lengths for simpler skipping along compiled
2914     code. This is again a macro in internal.h so that it is next to the
2915     definition of the opcodes.
2917     34. Added support for recursive calls to individual subpatterns, along the
2918     lines of Robin Houston's patch (but implemented somewhat differently).
2920     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2921     allow it to read and process whole directories in Win32. This code was
2922     contributed by Lionel Fourquaux; it has not been tested by me.
2924     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2925     used to name a group. Names consist of alphanumerics and underscores, and must
2926     be unique. Back references use the syntax (?P=name) and recursive calls use
2927     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2928     numbers. The function pcre_fullinfo() can be used after compilation to extract
2929     a name/number map. There are three relevant calls:
2931     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2932     PCRE_INFO_NAMECOUNT yields the number of entries
2933     PCRE_INFO_NAMETABLE yields a pointer to the map.
2935     The map is a vector of fixed-size entries. The size of each entry depends on
2936     the length of the longest name used. The first two bytes of each entry are the
2937     group number, most significant byte first. There follows the corresponding
2938     name, zero terminated. The names are in alphabetical order.
2940     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2941     case instead of 255. Making it the same both with and without UTF-8 support
2942     means that the same test output works with both.
2944     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2945     calling malloc() with a zero argument.
2947     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2948     optimization. I've improved things by keeping a bitmap of backreferences with
2949     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2950     fact referenced, the optimization can be applied. It is unlikely that a
2951     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2952     the match to follow \n) will appear inside brackets with a number greater than
2953     31, but if it does, any back reference > 31 suppresses the optimization.
2955     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2956     of disabling numbered capturing parentheses. Any opening parenthesis that is
2957     not followed by ? behaves as if it were followed by ?: but named parentheses
2958     can still be used for capturing (and they will acquire numbers in the usual
2959     way).
2961     41. Redesigned the return codes from the match() function into yes/no/error so
2962     that errors can be passed back from deep inside the nested calls. A malloc
2963     failure while inside a recursive subpattern call now causes the
2964     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2966     42. It is now possible to set a limit on the number of times the match()
2967     function is called in a call to pcre_exec(). This facility makes it possible to
2968     limit the amount of recursion and backtracking, though not in a directly
2969     obvious way, because the match() function is used in a number of different
2970     circumstances. The count starts from zero for each position in the subject
2971     string (for non-anchored patterns). The default limit is, for compatibility, a
2972     large number, namely 10 000 000. You can change this in two ways:
2974     (a) When configuring PCRE before making, you can use --with-match-limit=n
2975     to set a default value for the compiled library.
2977     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2978     a different value is set. See 45 below.
2980     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2982     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2983     of things that can be changed at compile time. The first argument specifies
2984     what is wanted and the second points to where the information is to be placed.
2985     The current list of available information is:
2989     The output is an integer that is set to one if UTF-8 support is available;
2990     otherwise it is set to zero.
2994     The output is an integer that it set to the value of the code that is used for
2995     newline. It is either LF (10) or CR (13).
2999     The output is an integer that contains the number of bytes used for internal
3000     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3004     The output is an integer that contains the threshold above which the POSIX
3005     interface uses malloc() for output vectors. See item 31 above.
3009     The output is an unsigned integer that contains the default limit of the number
3010     of match() calls in a pcre_exec() execution. See 42 above.
3012     44. pcretest has been upgraded by the addition of the -C option. This causes it
3013     to extract all the available output from the new pcre_config() function, and to
3014     output it. The program then exits immediately.
3016     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3017     order to support additional features. One way would have been to define
3018     pcre_exec2() (for example) with extra arguments, but this would not have been
3019     extensible, and would also have required all calls to the original function to
3020     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3021     is used for passing in "extra" data from pcre_study().
3023     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3024     contains the following fields:
3026     flags a bitmap indicating which of the following fields are set
3027     study_data opaque data from pcre_study()
3028     match_limit a way of specifying a limit on match() calls for a specific
3029     call to pcre_exec()
3030     callout_data data for callouts (see 49 below)
3032     The flag bits are also defined in pcre.h, and are
3038     The pcre_study() function now returns one of these new pcre_extra blocks, with
3039     the actual study data pointed to by the study_data field, and the
3040     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3041     before. That is, this change is entirely upwards-compatible and requires no
3042     change to existing code.
3044     If you want to pass in additional data to pcre_exec(), you can either place it
3045     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3046     block.
3048     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3049     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3050     times with different match limits, until it finds the minimum value needed for
3051     pcre_exec() to complete. The value is then output. This can be instructive; for
3052     most simple matches the number is quite small, but for pathological cases it
3053     gets very large very quickly.
3055     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3056     returns the size of the data block pointed to by the study_data field in a
3057     pcre_extra block, that is, the value that was passed as the argument to
3058     pcre_malloc() when PCRE was getting memory in which to place the information
3059     created by pcre_study(). The fourth argument should point to a size_t variable.
3060     pcretest has been extended so that this information is shown after a successful
3061     pcre_study() call when information about the compiled regex is being displayed.
3063     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3064     because what follows is always an absolute path. (Later: it turns out that this
3065     is more than cosmetic for MinGW, because it doesn't like empty path
3066     components.)
3068     49. Some changes have been made to the callout feature (see 28 above):
3070     (i) A callout function now has three choices for what it returns:
3072     0 => success, carry on matching
3073     > 0 => failure at this point, but backtrack if possible
3074     < 0 => serious error, return this value from pcre_exec()
3076     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3077     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3078     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3079     use by callout functions. It will never be used by PCRE itself.
3081     (ii) The pcre_extra structure (see 45 above) has a void * field called
3082     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3083     pcre_callout_block structure has a field of the same name. The contents of
3084     the field passed in the pcre_extra structure are passed to the callout
3085     function in the corresponding field in the callout block. This makes it
3086     easier to use the same callout-containing regex from multiple threads. For
3087     testing, the pcretest program has a new data escape
3089     \C*n pass the number n (may be negative) as callout_data
3091     If the callout function in pcretest receives a non-zero value as
3092     callout_data, it returns that value.
3094     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3095     there were some redundant $(CFLAGS) in commands that are now specified as
3096     $(LINK), which already includes $(CFLAGS).
3098     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3099     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3100     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3101     one-byte characters throughout. Note that case-insensitive matching applies
3102     only to characters whose values are less than 256. PCRE doesn't support the
3103     notion of cases for higher-valued characters.
3105     (i) A character class whose characters are all within 0-255 is handled as
3106     a bit map, and the map is inverted for negative classes. Previously, a
3107     character > 255 always failed to match such a class; however it should
3108     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3110     (ii) A negated character class with a single character < 255 is coded as
3111     "not this character" (OP_NOT). This wasn't working properly when the test
3112     character was multibyte, either singly or repeated.
3114     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3115     mode, for example: \x{100}{2,3}.
3117     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3118     singly or repeated) now correctly test multibyte characters. However,
3119     PCRE doesn't recognize any characters with values greater than 255 as
3120     digits, spaces, or word characters. Such characters always match \D, \S,
3121     and \W, and never match \d, \s, or \w.
3123     (v) Classes may now contain characters and character ranges with values
3124     greater than 255. For example: [ab\x{100}-\x{400}].
3126     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3127     PCRE in UTF-8 mode.
3129     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3130     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3131     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3132     value.)
3134     53. The single man page has become too large. I have therefore split it up into
3135     a number of separate man pages. These also give rise to individual HTML pages;
3136     these are now put in a separate directory, and there is an index.html page that
3137     lists them all. Some hyperlinking between the pages has been installed.
3139     54. Added convenience functions for handling named capturing parentheses.
3141     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3142     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3143     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3144     are faulted.
3146     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3147     calling configure. These values are used when compiling the dftables.c program
3148     which is run to generate the source of the default character tables. They
3149     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3150     you will need to set these values.
3152     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3155     Version 3.9 02-Jan-02
3156 nigel 61 ---------------------
3158     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3160     2. If --disable-static was given, the building process failed when trying to
3161     build pcretest and pcregrep. (For some reason it was using libtool to compile
3162     them, which is not right, as they aren't part of the library.)
3165 nigel 59 Version 3.8 18-Dec-01
3166     ---------------------
3168     1. The experimental UTF-8 code was completely screwed up. It was packing the
3169     bytes in the wrong order. How dumb can you get?
3172 nigel 57 Version 3.7 29-Oct-01
3173     ---------------------
3175     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3176     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3177     this didn't happen under Solaris 8, where I normally test things.
3179 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3180     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3181     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3182     this fix an hour or so after the initial 3.7 release.)
3183 nigel 57
3184 nigel 59
3185 nigel 55 Version 3.6 23-Oct-01
3186     ---------------------
3188     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3189     offsets passed as NULL with zero offset count.
3191     2. The config.guess and config.sub files had not been updated when I moved to
3192     the latest autoconf.
3195 nigel 53 Version 3.5 15-Aug-01
3196     ---------------------
3197 nigel 5
3198 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3199     had been forgotten.
3201     2. By using declared but undefined structures, we can avoid using "void"
3202     definitions in pcre.h while keeping the internal definitions of the structures
3203     private.
3205     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3206     user point of view, this means that both static and shared libraries are built
3207     by default, but this can be individually controlled. More of the work of
3208     handling this static/shared cases is now inside libtool instead of PCRE's make
3209     file.
3211     4. The pcretest utility is now installed along with pcregrep because it is
3212     useful for users (to test regexs) and by doing this, it automatically gets
3213     relinked by libtool. The documentation has been turned into a man page, so
3214     there are now .1, .txt, and .html versions in /doc.
3216     5. Upgrades to pcregrep:
3217     (i) Added long-form option names like gnu grep.
3218     (ii) Added --help to list all options with an explanatory phrase.
3219     (iii) Added -r, --recursive to recurse into sub-directories.
3220     (iv) Added -f, --file to read patterns from a file.
3222     6. pcre_exec() was referring to its "code" argument before testing that
3223     argument for NULL (and giving an error if it was NULL).
3225     7. Upgraded Makefile.in to allow for compiling in a different directory from
3226     the source directory.
3228     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3229     options bits, the pointer it was passed was to an int instead of to an unsigned
3230     long int. This mattered only on 64-bit systems.
3232     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3233     generated) instead of pcre.in, which it its source. Also made the same change
3234     in several of the .c files.
3236     10. A new release of gcc defines printf() as a macro, which broke pcretest
3237     because it had an ifdef in the middle of a string argument for printf(). Fixed
3238     by using separate calls to printf().
3240     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3241     script, to force use of CR or LF instead of \n in the source. On non-Unix
3242     systems, the value can be set in config.h.
3244     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3245     absolute limit. Changed the text of the error message to make this clear, and
3246     likewise updated the man page.
3248     13. The limit of 99 on the number of capturing subpatterns has been removed.
3249     The new limit is 65535, which I hope will not be a "real" limit.
3252 nigel 51 Version 3.4 22-Aug-00
3253     ---------------------
3255     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3257     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3260 nigel 49 Version 3.3 01-Aug-00
3261     ---------------------
3263     1. If an octal character was given, but the value was greater than \377, it
3264     was not getting masked to the least significant bits, as documented. This could
3265     lead to crashes in some systems.
3267     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3268     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3270     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3271     These just pass their arguments on to (pcre_free)(), but they are provided
3272     because some uses of PCRE bind it to non-C systems that can call its functions,
3273     but cannot call free() or pcre_free() directly.
3275     4. Add "make test" as a synonym for "make check". Corrected some comments in
3276     the Makefile.
3278     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3279     Makefile.
3281     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3282     command called pgrep for grepping around the active processes.
3284     7. Added the beginnings of support for UTF-8 character strings.
3286     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3287     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3288     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3289     out for the ar command.)
3292 nigel 47 Version 3.2 12-May-00
3293     ---------------------
3295     This is purely a bug fixing release.
3297     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3298     of ZA. This was just one example of several cases that could provoke this bug,
3299     which was introduced by change 9 of version 2.00. The code for breaking
3300     infinite loops after an iteration that matches an empty string was't working
3301     correctly.
3303     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3304     when matched against abbab (for example). After matching an empty string, it
3305     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3306     caused it to match further down the string than it should.
3308     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3309     was there because it doesn't seem to be needed, and it causes trouble on some
3310     systems, as it is not a Standard C header. It has been removed.
3312     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3313     were reported on the Macintosh. The changes were from
3315     while ((c = *(++ptr)) != 0 && c != '\n');
3316     to
3317     while ((c = *(++ptr)) != 0 && c != '\n') ;
3319     Totally extraordinary, but if that's what it takes...
3321     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3322     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3323     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3324     assumes the way PCRE uses memmove() (always moving upwards).
3326     6. PCRE is being used in one environment where strchr() is not available. There
3327     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3328     faster code anyway.
3331 nigel 45 Version 3.1 09-Feb-00
3332     ---------------------
3334     The only change in this release is the fixing of some bugs in Makefile.in for
3335     the "install" target:
3337     (1) It was failing to install pcreposix.h.
3339     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3342 nigel 43 Version 3.0 01-Feb-00
3343     ---------------------
3344 nigel 41
3345     1. Add support for the /+ modifier to perltest (to output $` like it does in
3346     pcretest).
3348     2. Add support for the /g modifier to perltest.
3350     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3351     matches null strings.
3353     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3354     pattern. Perl treats empty patterns specially - it reuses the most recent
3355     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3356     effect.
3358     5. The POSIX interface was broken in that it was just handing over the POSIX
3359     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3360     required a bigger vector, with some working space on the end. This means that
3361     the POSIX wrapper now has to get and free some memory, and copy the results.
3363 nigel 43 6. Added some simple autoconf support, placing the test data and the
3364     documentation in separate directories, re-organizing some of the
3365     information files, and making it build pcre-config (a GNU standard). Also added
3366     libtool support for building PCRE as a shared library, which is now the
3367     default.
3368 nigel 41
3369 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3370     09 are not valid octal constants. Single digits will be used for minor values
3371     less than 10.
3373     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3374     existing programs that set these in the POSIX interface can use PCRE without
3375     modification.
3377     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3378     return all that pcre_info() returns, plus additional data. The pcre_info()
3379     function is retained for compatibility, but is considered to be obsolete.
3381     10. Added experimental recursion feature (?R) to handle one common case that
3382     Perl 5.6 will be able to do with (?p{...}).
3384     11. Added support for POSIX character classes like [:alpha:], which Perl is
3385     adopting.
3388 nigel 39 Version 2.08 31-Aug-99
3389     ----------------------
3391     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3392     trying to match at the startoffset position, but instead was moving forward to
3393     the next newline as if a previous match had failed.
3395     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3396     and could get into a loop if a null string was matched other than at the start
3397     of the subject.
3399     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3400     be distinguished at compile time, and for completeness also added PCRE_DATE.
3402     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3403     in GnuWin32 environments.
3406 nigel 37 Version 2.07 29-Jul-99
3407     ----------------------
3409     1. The documentation is now supplied in plain text form and HTML as well as in
3410     the form of man page sources.
3412     2. C++ compilers don't like assigning (void *) values to other pointer types.
3413     In particular this affects malloc(). Although there is no problem in Standard
3414     C, I've put in casts to keep C++ compilers happy.
3416     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3417     should be (const char *).
3419     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3420     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3421     However, I haven't made this a standard facility. The documentation doesn't
3422     mention it, and the Makefile doesn't support it.
3424     5. The Makefile now contains an "install" target, with editable destinations at
3425     the top of the file. The pcretest program is not installed.
3427     6. pgrep -V now gives the PCRE version number and date.
3429     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3430     causing the entire string to be ignored, instead of just the last character.
3432     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3433     non-matching string, it can take a very, very long time, even for strings of
3434     quite modest length, because of the nested recursion. PCRE now does better in
3435     some of these cases. It does this by remembering the last required literal
3436     character in the pattern, and pre-searching the subject to ensure it is present
3437     before running the real match. In other words, it applies a heuristic to detect
3438     some types of certain failure quickly, and in the above example, if presented
3439     with a string that has no trailing " it gives "no match" very quickly.
3441     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3442     other alternatives are tried instead.
3445 nigel 35 Version 2.06 09-Jun-99
3446     ----------------------
3448     1. Change pcretest's output for amount of store used to show just the code
3449     space, because the remainder (the data block) varies in size between 32-bit and
3450     64-bit systems.
3452     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3453     start matching at. This allows lookbehinds to work when searching for multiple
3454     occurrences in a string.
3456     3. Added additional options to pcretest for testing multiple occurrences:
3458     /+ outputs the rest of the string that follows a match
3459     /g loops for multiple occurrences, using the new startoffset argument
3460     /G loops for multiple occurrences by passing an incremented pointer
3462     4. PCRE wasn't doing the "first character" optimization for patterns starting
3463     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3464     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3465     the letter 'x'. On long subject strings, this gives a significant speed-up.
3468 nigel 33 Version 2.05 21-Apr-99
3469     ----------------------
3471     1. Changed the type of magic_number from int to long int so that it works
3472     properly on 16-bit systems.
3474     2. Fixed a bug which caused patterns starting with .* not to work correctly
3475     when the subject string contained newline characters. PCRE was assuming
3476     anchoring for such patterns in all cases, which is not correct because .* will
3477     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3478     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3479     must be retried after every newline in the subject.
3482 nigel 31 Version 2.04 18-Feb-99
3483     ----------------------
3485     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3486     computation of the store needed to hold the pattern was incorrect (too large).
3487     If such patterns were nested a few deep, this could multiply and become a real
3488     problem.
3490     2. Added /M option to pcretest to show the memory requirement of a specific
3491     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3493     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3494     compiled in such a way that the backtracking after subsequent failure was
3495     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3496     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3499 nigel 29 Version 2.03 02-Feb-99
3500     ----------------------
3502     1. Fixed typo and small mistake in man page.
3504 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3505     LICENCE file containing the conditions.
3506 nigel 29
3507     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3508     Perl, that is the internal \ allows the delimiter to be included in the
3509     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3510     the final delimiter, add \ to the end of the pattern (to test the error).
3512     4. Added the convenience functions for extracting substrings after a successful
3513     match. Updated pcretest to make it able to test these functions.
3516 nigel 27 Version 2.02 14-Jan-99
3517     ----------------------
3519     1. Initialized the working variables associated with each extraction so that
3520     their saving and restoring doesn't refer to uninitialized store.
3522     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3523     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3524     fix the problem.
3526     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3527     calls, and wasn't printing the correct value for compiling calls. Increased the
3528     default value of LOOPREPEAT, and the number of significant figures in the
3529     times.
3531     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3533     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3534     a building problem on Windows NT with a FAT file system.
3537 nigel 25 Version 2.01 21-Oct-98
3538     ----------------------
3540     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3541     to character tables built by pcre_maketables() in the current locale. If NULL
3542     is passed, the default tables are used.
3545 nigel 23 Version 2.00 24-Sep-98
3546 nigel 21 ----------------------
3548 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3549     it any more.
3551     2. Allow quantification of (?>) groups, and make it work correctly.
3553     3. The first character computation wasn't working for (?>) groups.
3555     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3556     end of the subject) and add 5.005's \z, which really does match only at the
3557     very end of the subject.
3559     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3561     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3562     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3563     localized options. All options to pcre_study() were also removed.
3565     7. Add other new features from 5.005:
3567     $(?<= positive lookbehind
3568     $(?<! negative lookbehind
3569     (?imsx-imsx) added the unsetting capability
3570     such a setting is global if at outer level; local otherwise
3571     (?imsx-imsx:) non-capturing groups with option setting
3572     (?(cond)re|re) conditional pattern matching
3574     A backreference to itself in a repeated group matches the previous
3575     captured string.
3577     8. General tidying up of studying (both automatic and via "study")
3578     consequential on the addition of new assertions.
3580     9. As in 5.005, unlimited repeated groups that could match an empty substring
3581     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3582     runtime if any iteration does actually match an empty substring.
3584     10. Include the RunTest script in the distribution.
3586     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3587     discrepancies, some of which were old and were also with respect to 5.004. They
3588     have now been fixed.
3591     Version 1.09 28-Apr-98
3592     ----------------------
3594 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3595     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3596     program crashes, or just wrong answers. This did not apply to negated classes
3597     containing more than one character, or to minima other than one.
3600 nigel 19 Version 1.08 27-Mar-98
3601     ----------------------
3603     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3605     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3606     latter must appear before anything that relies on it in the pattern.
3609 nigel 17 Version 1.07 16-Feb-98
3610     ----------------------
3612     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3613     repeat of a potentially empty string).
3616 nigel 15 Version 1.06 23-Jan-98
3617     ----------------------
3619     1. Added Markus Oberhumer's little patches for C++.
3621     2. Literal strings longer than 255 characters were broken.
3624 nigel 13 Version 1.05 23-Dec-97
3625     ----------------------
3627     1. Negated character classes containing more than one character were failing if
3628     PCRE_CASELESS was set at run time.
3631 nigel 11 Version 1.04 19-Dec-97
3632     ----------------------
3634     1. Corrected the man page, where some "const" qualifiers had been omitted.
3636     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3637     input syntax.
3639     3. Fixed memory leak which occurred when a regex with back references was
3640     matched with an offsets vector that wasn't big enough. The temporary memory
3641     that is used in this case wasn't being freed if the match failed.
3643     4. Tidied pcretest to ensure it frees memory that it gets.
3645     5. Temporary memory was being obtained in the case where the passed offsets
3646     vector was exactly big enough.
3648     6. Corrected definition of offsetof() from change 5 below.
3650     7. I had screwed up change 6 below and broken the rules for the use of
3651     setjmp(). Now fixed.
3654 nigel 9 Version 1.03 18-Dec-97
3655     ----------------------
3657     1. A erroneous regex with a missing opening parenthesis was correctly
3658     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3659     on some systems.
3661     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3662     it was reported that one broken compiler failed on the former because "code" is
3663     also an independent variable.
3665     3. The erroneous regex a[]b caused an array overrun reference.
3667     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3668     fail on data ending with that character. (It was going on too far, and checking
3669     the next character, typically a binary zero.) This was specific to the
3670     optimized code for single-character negative classes.
3672     5. Added a contributed patch from the TIN world which does the following:
3674     + Add an undef for memmove, in case the the system defines a macro for it.
3676     + Add a definition of offsetof(), in case there isn't one. (I don't know
3677     the reason behind this - offsetof() is part of the ANSI standard - but
3678     it does no harm).
3680     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3681     most of the places where whitespace preceded '#'. I have given up and
3682     allowed the remaining 2 cases to be at the margin.
3684     + Rename some variables in pcre to eliminate shadowing. This seems very
3685     pedantic, but does no harm, of course.
3687     6. Moved the call to setjmp() into its own function, to get rid of warnings
3688     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3690     7. Constructs such as \d{8,} were compiling into the equivalent of
3691 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3692 nigel 9 outcome, but in this particular case used more store than had been allocated,
3693     which caused the bug to be discovered because it threw up an internal error.
3695     8. The debugging code in both pcre and pcretest for outputting the compiled
3696     form of a regex was going wrong in the case of back references followed by
3697     curly-bracketed repeats.
3700 nigel 7 Version 1.02 12-Dec-97
3701     ----------------------
3703     1. Typos in pcre.3 and comments in the source fixed.
3705     2. Applied a contributed patch to get rid of places where it used to remove
3706     'const' from variables, and fixed some signed/unsigned and uninitialized
3707     variable warnings.
3709     3. Added the "runtest" target to Makefile.
3711     4. Set default compiler flag to -O2 rather than just -O.
3714 nigel 5 Version 1.01 19-Nov-97
3715     ----------------------
3717     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3718     like /([ab]*)*/, that is, for classes with more than one character in them.
3720     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3721     as /((?>a*))*/ (a PCRE_EXTRA facility).
3724     Version 1.00 18-Nov-97
3725     ----------------------
3727     1. Added compile-time macros to support systems such as SunOS4 which don't have
3728     memmove() or strerror() but have other things that can be used instead.
3730     2. Arranged that "make clean" removes the executables.
3733 nigel 3 Version 0.99 27-Oct-97
3734     ----------------------
3736     1. Fixed bug in code for optimizing classes with only one character. It was
3737     initializing a 32-byte map regardless, which could cause it to run off the end
3738     of the memory it had got.
3740     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3743     Version 0.98 22-Oct-97
3744     ----------------------
3746     1. Fixed bug in code for handling temporary memory usage when there are more
3747     back references than supplied space in the ovector. This could cause segfaults.
3750     Version 0.97 21-Oct-97
3751     ----------------------
3753     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3755     2. Optimized negated single characters not to use a bit map.
3757     3. Brought error texts together as macro definitions; clarified some of them;
3758     fixed one that was wrong - it said "range out of order" when it meant "invalid
3759     escape sequence".
3761     4. Changed some char * arguments to const char *.
3763     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3765     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3766     pcretest.
3769     Version 0.96 16-Oct-97
3770     ----------------------
3772     1. Added a simple "pgrep" utility to the distribution.
3774     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3775     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3776     where "ddd" means "one or more decimal digits".
3778     3. Fixed serious bug. If a pattern had a back reference, but the call to
3779     pcre_exec() didn't supply a large enough ovector to record the related
3780     identifying subpattern, the match always failed. PCRE now remembers the number
3781     of the largest back reference, and gets some temporary memory in which to save
3782     the offsets during matching if necessary, in order to ensure that
3783     backreferences always work.
3785     4. Increased the compatibility with Perl in a number of ways: