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Revision 521 - (hide annotations) (download)
Sat May 22 19:03:35 2010 UTC (4 years, 10 months ago) by ph10
File size: 187086 byte(s)
Remove explicit include of pcre.h from pcreposix.c because pcre_internal.h 
already includes it. This avoids a PCRE_EXP_DECL problem.

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 519
40     10. Added --line-buffered to pcregrep.
41 ph10 513
42 ph10 520 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43     studied, and the match started with a letter with a code point greater than
44     127 whose first byte was different to the first byte of the other case of
45     the letter, the other case of this starting letter was not recognized.
46 ph10 521
47     12. pcreposix.c included pcre.h before including pcre_internal.h. This caused a
48     conflict in the definition of PCRE_EXP_DECL. I have removed the include of
49     pcre.h as pcre_internal.h includes pcre.h itself. (This may be a bit of
50     historical tidying that never got done.)
52 ph10 517
53 ph10 520
54 ph10 508 Version 8.02 19-Mar-2010
55 ph10 491 ------------------------
57     1. The Unicode data tables have been updated to Unicode 5.2.0.
59 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
60     configured.
61 ph10 507
62 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
63 ph10 507 original author of that file, following a query about its status.
65     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
66 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
67 ph10 507
68 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
69     quantifier applied to a forward-referencing subroutine call, could compile
70     incorrect code or give the error "internal error: previously-checked
71     referenced subpattern not found".
72 ph10 507
73     6. Both MS Visual Studio and Symbian OS have problems with initializing
74 ph10 497 variables to point to external functions. For these systems, therefore,
75     pcre_malloc etc. are now initialized to local functions that call the
76     relevant global functions.
77 ph10 507
78 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
79     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
80 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
81     the lengths are correct (equal to the number of opcodes).
83     8. Following on from 7, I added a similar kludge to check the length of the
84     eint vector in pcreposix.c.
86     9. Error texts for pcre_compile() are held as one long string to avoid too
87     much relocation at load time. To find a text, the string is searched,
88 ph10 499 counting zeros. There was no check for running off the end of the string,
89     which could happen if a new error number was added without updating the
90 ph10 507 string.
92     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
94 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
95 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
96     \K is "not well defined" if used in an assertion. PCRE now accepts it if
97     the assertion is positive, but not if it is negative.
99 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
100 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
101     implementation of support for (*MARK) will need an extra pointer on the
102 ph10 501 stack; I have reserved it now, so that the stack frame size does not
103     decrease.
104 ph10 507
105     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
106     item in branch that calls a recursion is a subroutine call - as in the
107 ph10 503 second branch in the above example - was incorrectly given the compile-
108     time error "recursive call could loop indefinitely" because pcre_compile()
109 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
111 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
112 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
113 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
114 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
115 ph10 491
116 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
117 ph10 492
118 ph10 507
119 ph10 489 Version 8.01 19-Jan-2010
120     ------------------------
121 ph10 471
122     1. If a pattern contained a conditional subpattern with only one branch (in
123 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
124 ph10 473 computed the wrong minimum data length (which is of course zero for such
125 ph10 489 subpatterns). This could cause incorrect "no match" results.
126 ph10 473
127     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
128 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
129     "internal error: code overflow at offset...". This happened only when
130 ph10 473 the reset was to the original external option setting. (An optimization
131     abstracts leading options settings into an external setting, which was the
132 ph10 472 cause of this.)
133 ph10 471
134 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
135     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
136     assertion pattern did not match (meaning that the assertion was true), it
137     was incorrectly treated as false if the SKIP had been reached during the
138     matching. This also applied to assertions used as conditions.
139 ph10 471
140 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
141     assertion subpattern, including such a pattern used as a condition,
142     unpredictable results occurred, instead of the error return
144 ph10 478
145 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
146     situation when an empty string is matched. It now does the fancy magic
147 ph10 478 stuff that is necessary.
149     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
150 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
151 ph10 478
152 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
153     as part of something else:
154 ph10 478
155     (a) Change DEBUG to PCRE_DEBUG.
157     (b) In pcre_compile(), rename the member of the "branch_chain" structure
158     called "current" as "current_branch", to prevent a collision with the
159 ph10 475 Linux macro when compiled as a kernel module.
160 ph10 478
161     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
162     prevent a collision with the Linux macro when compiled as a kernel
163 ph10 475 module.
164 ph10 478
165 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
166     cast potentially large values to (double). This has been changed to that
167 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
168     instead, thus avoiding the use of floating point arithmetic. (There is no
169     other use of FP in PCRE.) If int64_t is not found, the fallback is to
170     double.
172     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
173 ph10 476 2005 (difference between two addresses compared to an unsigned value).
174 ph10 473
175 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
176     custom one, because of the following reported problem in Windows:
177 ph10 473
178 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
179 ph10 489 under Win32.
180 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
181 ph10 489 therefore missing the function definition.
182 ph10 478 - The compiler thus generates a "C" signature for the test function.
183     - The linker fails to find the "C" function.
184     - PCRE fails to configure if asked to do so against libbz2.
185 ph10 486
186 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
187     messages were output:
188 ph10 478
189 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
190     rerunning libtoolize, to keep the correct libtool macros in-tree.
191     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
192 ph10 486
193 ph10 479 I have done both of these things.
194 ph10 486
195 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
196 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
197     runaway infinite recursion. I updated the discussion in the pcrestack man
198     page.
200     13. Now that we have gone to the x.xx style of version numbers, the minor
201     version may start with zero. Using 08 or 09 is a bad idea because users
202     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
203     interpreted as invalid octal numbers. I've updated the previous comment in
204     configure.ac, and also added a check that gives an error if 08 or 09 are
205 ph10 481 used.
206 ph10 486
207 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
208 ph10 483 causing partial matching to fail when the end of the subject matched \W
209     in a UTF-8 pattern where \W was quantified with a minimum of 3.
210 ph10 486
211 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
212 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
213 ph10 483 their definitions. The declarations used "const uschar *" and the
214     definitions used USPTR. Even though USPTR is normally defined as "const
215     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
216     reported that: "This difference in casting confuses some C++ compilers, for
217     example, SunCC recognizes above declarations as different functions and
218 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
219 ph10 483 USPTR.
220 ph10 486
221     16. GNU libtool is named differently on some systems. The autogen.sh script now
222 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
223     (FreeBSD).
224 ph10 478
225 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
226     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
227     comment: "Figure out how to create a longlong from a string: strtoll and
228     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
229     instance, but it only takes 2 args instead of 3!"
230 ph10 479
231 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
232     specification, with a corresponding code fix. A pattern such as
233     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
234     refers, was giving matches when it shouldn't. For example, xa=xaaa would
235     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
236     same bug. Such groups have to be quantified to be useful, or contained
237     inside another quantified group. (If there's no repetition, the reference
238     can never match.) The problem arises because, having left the group and
239     moved on to the rest of the pattern, a later failure that backtracks into
240     the group uses the captured value from the final iteration of the group
241     rather than the correct earlier one. I have fixed this in PCRE by forcing
242     any group that contains a reference to itself to be an atomic group; that
243     is, there cannot be any backtracking into it once it has completed. This is
244     similar to recursive and subroutine calls.
245 ph10 486
246 ph10 488
247 ph10 469 Version 8.00 19-Oct-09
248 ph10 418 ----------------------
250     1. The table for translating pcre_compile() error codes into POSIX error codes
251 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
252     being within the table. This could lead to an OK return being given in
253 ph10 418 error.
254 ph10 461
255     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
256     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
257     in a Windows environment.
259 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
260     zero, as does GNU grep. However, pcregrep was also printing all files when
261     --files-with-matches was added. Now, when both options are given, it prints
262     counts only for those files that have at least one match. (GNU grep just
263 ph10 461 prints the file name in this circumstance, but including the count seems
264     more useful - otherwise, why use --count?) Also ensured that the
265 ph10 420 combination -clh just lists non-zero counts, with no names.
266 ph10 461
267     4. The long form of the pcregrep -F option was incorrectly implemented as
268     --fixed_strings instead of --fixed-strings. This is an incompatible change,
269     but it seems right to fix it, and I didn't think it was worth preserving
270     the old behaviour.
272     5. The command line items --regex=pattern and --regexp=pattern were not
273 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
274 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
275 ph10 422 which are compatible with GNU grep; these now work.
276 ph10 461
277     6. No libpcreposix.pc file was created for pkg-config; there was just
278 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
279 ph10 461
280 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
281 ph10 461 when UCP support is not needed, by modifying the Python script that
282 ph10 425 generates it from Unicode data files. This should not matter if the module
283     is correctly used as a library, but I received one complaint about 50K of
284     unwanted data. My guess is that the person linked everything into his
285     program rather than using a library. Anyway, it does no harm.
286 ph10 461
287 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
288 ph10 461 was a minimum greater than 1 for a wide character in a possessive
289 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
290     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
291     character. Chaos in the form of incorrect output or a compiling loop could
292     result.
293 ph10 461
294 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
295 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
296 ph10 426 partially matched by this function. In addition, if there are at least two
297 ph10 435 slots in the offset vector, the offset of the earliest inspected character
298     for the match and the offset of the end of the subject are set in them when
299 ph10 461 PCRE_ERROR_PARTIAL is returned.
301 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
302     synonymous with PCRE_PARTIAL, for backwards compatibility, and
303     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
304 ph10 462 and may be more useful for multi-segment matching.
305 ph10 461
306     11. Partial matching with pcre_exec() is now more intuitive. A partial match
307     used to be given if ever the end of the subject was reached; now it is
308     given only if matching could not proceed because another character was
309     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
310     string "Z", which now yields "no match" instead of "partial match". In the
311     case of pcre_dfa_exec(), "no match" is given if every matching path for the
312     final character ended with (*FAIL).
314 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
315 ph10 461 if the pattern had a "must contain" character that was already found in the
316 ph10 428 earlier partial match, unless partial matching was again requested. For
317     example, with the pattern /dog.(body)?/, the "must contain" character is
318     "g". If the first part-match was for the string "dog", restarting with
319 ph10 435 "sbody" failed. This bug has been fixed.
320 ph10 461
321     13. The string returned by pcre_dfa_exec() after a partial match has been
322     changed so that it starts at the first inspected character rather than the
323     first character of the match. This makes a difference only if the pattern
324     starts with a lookbehind assertion or \b or \B (\K is not supported by
325     pcre_dfa_exec()). It's an incompatible change, but it makes the two
326 ph10 435 matching functions compatible, and I think it's the right thing to do.
327 ph10 461
328 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
329 ph10 461 so that the demonstration program is easily available in environments where
330     PCRE has not been installed from source.
332 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
333 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
334     library.
335 ph10 461
336 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
337 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
338 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
339 ph10 433 these options useful.
340 ph10 461
341     17. If a caller to the POSIX matching function regexec() passes a non-zero
342 ph10 438 value for nmatch with a NULL value for pmatch, the value of
343 ph10 461 nmatch is forced to zero.
345 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
346 ph10 461 the diff command, as RunTest does. It now checks in the same way as
347 ph10 437 RunTest, and also checks for the -b option.
348 ph10 461
349 ph10 438 19. If an odd number of negated classes containing just a single character
350     interposed, within parentheses, between a forward reference to a named
351 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
352     an internal error, complaining that it could not find the referenced
353 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
354 ph10 461 [The bug was that it was starting one character too far in when skipping
355     over the character class, thus treating the ] as data rather than
356     terminating the class. This meant it could skip too much.]
358 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
359 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
360 ph10 442 to have an empty string match not at the start, even when the pattern is
361 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
363 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
364 ph10 461 than the maximum at the outer level, the higher number was returned, but
365     with unset values at the outer level. The correct (outer level) value is
366 ph10 446 now given.
367 ph10 461
368 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
369     PCRE did not set those parentheses (unlike Perl). I have now found a way to
370     make it do so. The string so far is captured, making this feature
371     compatible with Perl.
372 ph10 461
373     23. The tests have been re-organized, adding tests 11 and 12, to make it
374 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
375 ph10 461
376 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
377 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
378     does. Neither allows recursion.
380     25. I finally figured out how to implement a request to provide the minimum
381     length of subject string that was needed in order to match a given pattern.
382     (It was back references and recursion that I had previously got hung up
383     on.) This code has now been added to pcre_study(); it finds a lower bound
384 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
385     bound, but using it to avoid searching strings that are too short does give
386     some useful speed-ups. The value is available to calling programs via
387     pcre_fullinfo().
388 ph10 461
389 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
390     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
391     study optimizations had never been tested with that matching function.
392     Oops. What is worse, even when it was passed study data, there was a bug in
393     pcre_dfa_exec() that meant it never actually used it. Double oops. There
394     were also very few tests of studied patterns with pcre_dfa_exec().
395 ph10 461
396 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
397     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
398     on the other side of the coin, they are no longer allowed to have different
399     names, because these cannot be distinguished in PCRE, and this has caused
400     confusion. (This is a difference from Perl.)
401 ph10 461
402     28. When duplicate subpattern names are present (necessarily with different
403     numbers, as required by 27 above), and a test is made by name in a
404     conditional pattern, either for a subpattern having been matched, or for
405     recursion in such a pattern, all the associated numbered subpatterns are
406 ph10 459 tested, and the overall condition is true if the condition is true for any
407     one of them. This is the way Perl works, and is also more like the way
408     testing by number works.
409 ph10 418
410 ph10 461
411 ph10 412 Version 7.9 11-Apr-09
412 ph10 376 ---------------------
414 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
415 ph10 376 (pcretest), all targets were linked against these libraries. This included
416     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
417     libraries. This caused unwanted dependencies to be created. This problem
418 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
419 ph10 376 pcretest is linked with readline.
420 ph10 392
421 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
422     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
423     moved outside it again, because FALSE and TRUE are already defined in AIX,
424     but BOOL is not.
425 ph10 392
426     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
427 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
428 ph10 392
429 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
430     hyphens) following file names and line numbers when outputting matching
431 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
432 ph10 376 wording for the --colour (or --color) option.
433 ph10 392
434 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
435     was not coloured; this is different to GNU grep, so I have changed it to be
436     the same.
437 ph10 392
438 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
439 ph10 392 each matching line was coloured. Now it goes on to look for further matches
440     of any of the test patterns, which is the same behaviour as GNU grep.
442     7. A pattern that could match an empty string could cause pcregrep to loop; it
443     doesn't make sense to accept an empty string match in pcregrep, so I have
444 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
445     seems to be how GNU grep behaves.
446 ph10 392
447 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
448 ph10 392 start or after a newline", because the conditional assertion was not being
449     correctly handled. The rule now is that both the assertion and what follows
450     in the first alternative must satisfy the test.
452 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
453 ph10 399 condition was an assertion, PCRE could crash during matching, both with
454     pcre_exec() and pcre_dfa_exec().
455 ph10 392
456     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
457     used for matching.
459     11. Unicode property support in character classes was not working for
460 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
461 ph10 388
462 ph10 392 12. Added the -M command line option to pcretest.
464 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
465 ph10 389
466     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
467 ph10 390
468 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
469 ph10 390 wrapper.
470 ph10 392
471 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
472 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
473 ph10 391 string constants.
474 ph10 405
475 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
476     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
477 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
478     these, but not everybody uses configure.
480     19. A conditional group that had only one branch was not being correctly
481     recognized as an item that could match an empty string. This meant that an
482     enclosing group might also not be so recognized, causing infinite looping
483     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
484     with the subject "ab", where knowledge that the repeated group can match
485 ph10 396 nothing is needed in order to break the loop.
486 ph10 405
487 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
488 ph10 405 exec(), but without supplying a callout function, matching went wrong.
490     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
491     leak if the size of the offset vector was greater than 30. When the vector
492     is smaller, the saved offsets during recursion go onto a local stack
493     vector, but for larger vectors malloc() is used. It was failing to free
494     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
495 ph10 400 error, in fact).
496 ph10 405
497 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
498 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
499     problem, but was untidy.
500 ph10 376
501 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
502     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
503     included within another project.
504 ph10 411
505 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
506     slightly modified by me:
507 ph10 411
508     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
509     not building pcregrep.
511 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
512 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
514 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
515     duplicate group numbers, could behave incorrectly or give incorrect errors,
516     because when scanning forward to find the reference group, PCRE was not
517     taking into account the duplicate group numbers. A pattern such as
518     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
519 ph10 411
520     26. Changed a few more instances of "const unsigned char *" to USPTR, making
521     the feature of a custom pointer more persuasive (as requested by a user).
522 ph10 416
523 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
524 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
525     pre-defined.
526 ph10 392
527 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
529 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
530     in the configuration summary.
531 ph10 405
532 ph10 411
533 ph10 374 Version 7.8 05-Sep-08
534 ph10 349 ---------------------
536     1. Replaced UCP searching code with optimized version as implemented for Ad
537     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
538 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
539     to 5 times on some simple patterns that I tested. Permission was given to
540     distribute the MultiStage2.py script that generates the tables (it's not in
541     the tarball, but is in the Subversion repository).
542 ph10 349
543 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
544     scripts.
545 ph10 358
546 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
547     a group with a zero qualifier. The result of the study could be incorrect,
548 ph10 358 or the function might crash, depending on the pattern.
550     4. Caseless matching was not working for non-ASCII characters in back
551 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
552 ph10 358 It now works when Unicode Property Support is available.
554 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
555     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
556     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
557 ph10 358 truncation.
558 ph10 349
559 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
561 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
562     pointers, in case they are 64-bit values.
563 ph10 371
564     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
565     test 2 if it fails.
567 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
568 ph10 371 and a #define of that name to empty if it is not externally set. This is to
569     allow users of MSVC to set it if necessary.
571     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
572 ph10 359 the convenience functions in the pcre_get.c source file.
573 ph10 371
574 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
575     could cause overwriting and/or a crash. This command provoked a crash in
576 ph10 371 some environments:
578     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
580 ph10 360 This potential security problem was recorded as CVE-2008-2371.
581 ph10 371
582 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
583     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
584 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
585 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
586     pcretest so that it places the subject at the end of its malloc-ed buffer.
587 ph10 371
588 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
589 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
591 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
592 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
593     first line. This applied both to normal and DFA matching.
595 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
596 ph10 371 /^[^d]*?$/8 failed to match "abc".
597 ph10 351
598 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
600     17. Make it more clear in the documentation that values returned from
601 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
602 ph10 357
603 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
604 ph10 368
605 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
606     supplied by Stefan Weber. I made a further small update for 7.8 because
607 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
608     replaced by pcre_ucd.c.
609 ph10 371
610 ph10 373
611 ph10 347 Version 7.7 07-May-08
612 ph10 321 ---------------------
614     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
615 ph10 345 a string to a long long, pretend we don't even have a long long." This is
616 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
617 ph10 345
618 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
619     pre-7.6 versions, which defined a global no_arg variable instead of putting
620 ph10 332 it in the RE class. (See also #8 below.)
621 ph10 345
622     3. Remove a line of dead code, identified by coverity and reported by Nuno
623     Lopes.
625 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
626 ph10 321
627 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
628 ph10 345 of files, instead of just to the final components.
630 ph10 324 (2) If there was more than one level of directory, the subdirectories were
631     skipped unless they satisfied the include/exclude conditions. This is
632     inconsistent with GNU grep (and could even be seen as contrary to the
633     pcregrep specification - which I improved to make it absolutely clear).
634     The action now is always to scan all levels of directory, and just
635     apply the include/exclude patterns to regular files.
636 ph10 345
637 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
638 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
640 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
641 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
642 ph10 326 doesn't support NULs in patterns.
643 ph10 345
644     7. Added some missing "const"s to declarations of static tables in
645     pcre_compile.c and pcre_dfa_exec.c.
647 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
648 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
649 ph10 345 first patch. And a third patch - this was a messy problem.)
650 ph10 321
651 ph10 345 9. Applied Craig's patch to remove the use of push_back().
653 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
654     matching function regexec().
655 ph10 345
656     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
657     which, however, unlike Perl's \g{...}, are subroutine calls, not back
658 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
659     Oniguruma does).
660 ph10 345
661     12. Previously, a group with a zero repeat such as (...){0} was completely
662 ph10 335 omitted from the compiled regex. However, this means that if the group
663     was called as a subroutine from elsewhere in the pattern, things went wrong
664 ph10 345 (an internal error was given). Such groups are now left in the compiled
665     pattern, with a new opcode that causes them to be skipped at execution
666 ph10 335 time.
667 ph10 345
668 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
669     to the way PCRE behaves:
670 ph10 345
671 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
672 ph10 345
673     (b) A back reference to an unmatched subpattern matches an empty string
674 ph10 336 (Perl fails the current match path).
675 ph10 345
676 ph10 341 (c) A data ] in a character class must be notated as \] because if the
677 ph10 345 first data character in a class is ], it defines an empty class. (In
678 ph10 341 Perl it is not possible to have an empty class.) The empty class []
679     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
680     The negative empty class [^] matches any one character, independently
681     of the DOTALL setting.
682 ph10 345
683     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
684 ph10 340 non-existent subpattern following a character class starting with ']' and
685     containing () gave an internal compiling error instead of "reference to
686     non-existent subpattern". Fortunately, when the pattern did exist, the
687 ph10 345 compiled code was correct. (When scanning forwards to check for the
688 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
689 ph10 345 the class, so got the count wrong. When actually compiling, the reference
690 ph10 340 was subsequently set up correctly.)
691 ph10 345
692 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
693 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
694     other assertions are supported. I have made pcre_dfa_exec() support
695     (*FAIL).
697 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
698 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
699     cannot be changed at match time, I realized I could make a small
700     improvement to matching performance by compiling OP_ALLANY instead of
701     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
702     on the OP_ANY path.
704     17. Compiling pcretest on Windows with readline support failed without the
705 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
706 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
708 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
709 ph10 345 ncurses library to be included for pcretest when ReadLine support is
710     requested, but also to allow for it to be overridden. This patch came from
711     Daniel Bergström.
712 ph10 347
713 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
714 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
715     any errors with the current Unicode tables. Thanks to Peter Kankowski for
716     spotting this.
717 ph10 324
718 ph10 332
719 ph10 319 Version 7.6 28-Jan-08
720 ph10 300 ---------------------
722 ph10 302 1. A character class containing a very large number of characters with
723     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
724     overflow.
725 ph10 309
726     2. Patch to cut out the "long long" test in pcrecpp_unittest when
727     HAVE_LONG_LONG is not defined.
729 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
730 ph10 304 bring them up to date and include new features. This patch includes:
731 ph10 309
732 ph10 304 - Fixed PH's badly added libz and libbz2 support.
733     - Fixed a problem with static linking.
734 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
735 ph10 304 - Fixed dftables problem and added an option.
736     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
738     - Added readline support for pcretest.
739 ph10 309 - Added an listing of the option settings after cmake has run.
741 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
742     "pcre.dll" under mingw when using Configure/Make. I added stuff to
743     Makefile.am that cause it to include this special target, without
744     affecting anything else. Note that the same mingw target plus all
745     the other distribution libraries and programs are now supported
746     when configuring with CMake (see 6 below) instead of with
747     Configure/Make.
748 ph10 309
749 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
750     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
751 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
752     solves the problem, but it does no harm.
753 ph10 313
754 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
755 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
756 ph10 314 with CMake, and also correct the comment about stack recursion.
757 ph10 313
758 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
759 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
760     of a program that users should build themselves after PCRE is installed, so
761     building it automatically is not really right. What is more, it gave
762 ph10 312 trouble in some build environments.
763 ph10 300
764 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
765 ph10 308
766 ph10 319
767 ph10 298 Version 7.5 10-Jan-08
768 ph10 263 ---------------------
770     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
771     values in parens when parsing an RE using the C++ wrapper."
772 ph10 286
773 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
774     Characters greater than 255 were excluded from the class instead of being
775     included.
776 ph10 286
777     3. The same bug as (2) above applied to negated POSIX classes such as
778 ph10 265 [:^space:].
779 ph10 286
780 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
781     defined or documented. It seems to have been a typo for PCRE_STATIC, so
782 ph10 286 I have changed it.
784 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
785 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
786     first named subpattern whose name started with "a" (in other words, the
787 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
788     expected" is now given for (?&) (a zero-length name), and this patch also
789     makes it give the same error for \k'' (previously it complained that that
790     was a reference to a non-existent subpattern).
791 ph10 286
792 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
793 ph10 286 this is right because (?- can be followed by option settings as well as by
794 ph10 269 digits. I have, however, made the messages clearer.
795 ph10 286
796 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
797     than the number used in the conditional) now cause a compile-time error.
798     This is actually not compatible with Perl, which accepts such patterns, but
799     treats the conditional as always being FALSE (as PCRE used to), but it
800     seems to me that giving a diagnostic is better.
801 ph10 286
802 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
803 ph10 275 and messages.
804 ph10 286
805     9. Fix two occurrences of "backslash" in comments that should have been
806     "backspace".
808     10. Remove two redundant lines of code that can never be obeyed (their function
809     was moved elsewhere).
811     11. The program that makes PCRE's Unicode character property table had a bug
812     which caused it to generate incorrect table entries for sequences of
813 ph10 277 characters that have the same character type, but are in different scripts.
814 ph10 286 It amalgamated them into a single range, with the script of the first of
815 ph10 277 them. In other words, some characters were in the wrong script. There were
816     thirteen such cases, affecting characters in the following ranges:
817 ph10 286
818 ph10 277 U+002b0 - U+002c1
819     U+0060c - U+0060d
820 ph10 286 U+0061e - U+00612
821 ph10 277 U+0064b - U+0065e
822     U+0074d - U+0076d
823     U+01800 - U+01805
824     U+01d00 - U+01d77
825     U+01d9b - U+01dbf
826     U+0200b - U+0200f
827     U+030fc - U+030fe
828     U+03260 - U+0327f
829     U+0fb46 - U+0fbb1
830     U+10450 - U+1049d
831 ph10 286
832 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
833     compatible with GNU grep in that, if there was more than one match in a
834     line, it showed only the first of them. It now behaves in the same way as
835     GNU grep.
836 ph10 286
837     13. If the -o and -v options were combined for pcregrep, it printed a blank
838     line for every non-matching line. GNU grep prints nothing, and pcregrep now
839     does the same. The return code can be used to tell if there were any
840     non-matching lines.
842 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
844     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
845 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
846 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
847     and both kinds of lookbehind were skipped).
849 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
850 ph10 284 inclusion of <windows.h> to before rather than after the definition of
851     INVALID_FILE_ATTRIBUTES (patch from David Byron).
852 ph10 263
853 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
854 ph10 286 character property caused pcre_compile() to compile bad code, which led at
855     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
856     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
857     caused the error; without that there was no problem.
858 ph10 263
859 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
860 ph10 286
861 ph10 289 19. Added --enable-pcretest-libreadline.
862 ph10 286
863 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
864 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
865 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
866     later patch that removed the other one (the right fix) and added unit tests
867     that check the return values (which was not done before).
868 ph10 292
869 ph10 291 21. Several CMake things:
870 ph10 287
871 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
872 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
873 ph10 288
874 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
875     linked with the newly-built libraries, not previously installed ones.
876 ph10 291
878 ph10 298
879     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
880     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
881     UTF-8 newline character). The key issue is that the pattern starts .*;
882     this means that the match must be either at the beginning, or after a
883     newline. The bug was in the code for advancing after a failed match and
884     checking that the new position followed a newline. It was not taking
885 ph10 294 account of UTF-8 characters correctly.
886 ph10 298
887     23. PCRE was behaving differently from Perl in the way it recognized POSIX
888     character classes. PCRE was not treating the sequence [:...:] as a
889     character class unless the ... were all letters. Perl, however, seems to
890     allow any characters between [: and :], though of course it rejects as
891     unknown any "names" that contain non-letters, because all the known class
892     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
893     for example, whereas PCRE did not - it did not recognize a POSIX character
894     class. This seemed a bit dangerous, so the code has been changed to be
895     closer to Perl. The behaviour is not identical to Perl, because PCRE will
896     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
897     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
898     Perl does, and where it didn't before.
900 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
901     Windows environments %n is disabled by default.
902 ph10 292
904 ph10 260 Version 7.4 21-Sep-07
905 ph10 230 ---------------------
907     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
908 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
909     LF". That isn't really right - the whole point of the change was to try to
910     help when there was an actual mention of one of the two characters. So now
911     the change happens only if \r or \n (or a literal CR or LF) character is
912 ph10 230 encountered.
913 ph10 231
914     2. The 32-bit options word was also used for 6 internal flags, but the numbers
915     of both had grown to the point where there were only 3 bits left.
916     Fortunately, there was spare space in the data structure, and so I have
917     moved the internal flags into a new 16-bit field to free up more option
918 ph10 230 bits.
919 ph10 231
920     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
921     but did not set the internal JCHANGED flag - either of these is enough to
922     control the way the "get" function works - but the PCRE_INFO_JCHANGED
923     facility is supposed to tell if (?J) was ever used, so now (?J) at the
924 ph10 230 start sets both bits.
926 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
927     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
928 ph10 230
929 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
931     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
932 ph10 233 compatibility, even though it is no longer used.
933 ph10 243
934     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
935 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
936 ph10 259 windows.h file is present (where different names are used). [This was
937 ph10 257 reversed later after testing - see 16 below.]
938 ph10 243
939     8. Changed all #include <config.h> to #include "config.h". There were also
940 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
941 ph10 243
942 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
943 ph10 243 sequence off the lines that it output.
945     10. It was pointed out to me that arrays of string pointers cause lots of
946     relocations when a shared library is dynamically loaded. A technique of
947     using a single long string with a table of offsets can drastically reduce
948     these. I have refactored PCRE in four places to do this. The result is
949 ph10 240 dramatic:
950 ph10 243
951 ph10 240 Originally: 290
952     After changing UCP table: 187
953 ph10 243 After changing error message table: 43
954 ph10 240 After changing table of "verbs" 36
955     After changing table of Posix names 22
956 ph10 243
957 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
958 ph10 247
959 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
960 ph10 247 unicode-properties was also set.
962 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
963 ph10 231
964 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
965     checked only for CRLF.
966 ph10 233
967 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
969 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
970 ph10 253
971 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
972 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
973     entirely. This removes changes made in 7 above.
974 ph10 256
975 ph10 261 17. The CMake files have been updated, and there is now more information about
976     building with CMake in the NON-UNIX-USE document.
977 ph10 257
978 ph10 261
979 ph10 228 Version 7.3 28-Aug-07
980 ph10 157 ---------------------
982 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
983     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
984     brackets there is not right, since it causes compilers to look for an
985     installed pcre.h, not the version that is in the source that is being
986     compiled (which of course may be different). I have changed it back to:
987 ph10 197
988 ph10 189 #include "pcre.h"
989 ph10 197
990     I have a vague recollection that the change was concerned with compiling in
991     different directories, but in the new build system, that is taken care of
992     by the VPATH setting the Makefile.
994 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
995     when the subject happened to end in the byte 0x85 (e.g. if the last
996     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
997     characters but of course it shouldn't be taken as a newline when it is part
998     of another character. The bug was that, for an unlimited repeat of . in
999     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1000     characters when looking for a newline.
1001 ph10 197
1002     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1004     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1005     in debug output.
1007 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1008     long printing in the pcrecpp unittest when running under MinGW.
1009 ph10 189
1010 ph10 197 6. ESC_K was left out of the EBCDIC table.
1011 ph10 189
1012 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1013     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1014     limit also applies to "virtual nesting" when a pattern is recursive, and in
1015     this case 1000 isn't so big. I have been able to remove this limit at the
1016     expense of backing off one optimization in certain circumstances. Normally,
1017     when pcre_exec() would call its internal match() function recursively and
1018     immediately return the result unconditionally, it uses a "tail recursion"
1019     feature to save stack. However, when a subpattern that can match an empty
1020     string has an unlimited repetition quantifier, it no longer makes this
1021     optimization. That gives it a stack frame in which to save the data for
1022     checking that an empty string has been matched. Previously this was taken
1023     from the 1000-entry workspace that had been reserved. So now there is no
1024     explicit limit, but more stack is used.
1025 ph10 189
1026 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1027     syntax that is required for Windows, and which was going wrong for the
1028     pcreposix and pcrecpp parts of the library. These were overlooked when this
1029     problem was solved for the main library.
1030 ph10 197
1031 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1032     the size of patterns that contain repeated groups with explicit upper
1033     limits. As the maximum quantifier is 65535, the maximum group length was
1034     set at 30,000 so that the product of these two numbers did not overflow a
1035     32-bit integer. However, it turns out that people want to use groups that
1036     are longer than 30,000 bytes (though not repeat them that many times).
1037     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1038     made it possible to implement the integer overflow checks in a much more
1039     dynamic way, which I have now done. The artificial limitation on group
1040     length has been removed - we now have only the limit on the total length of
1041     the compiled pattern, which depends on the LINK_SIZE setting.
1042 ph10 208
1043     10. Fixed a bug in the documentation for get/copy named substring when
1044     duplicate names are permitted. If none of the named substrings are set, the
1045     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1046     empty string.
1048     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1049     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1050     because the ] is interpreted as the first data character and the
1051     terminating ] is not found. PCRE has been made compatible with Perl in this
1052     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1053     cause memory overwriting.
1055 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1056     string has been matched (to stop an infinite loop). It was not recognizing
1057 ph10 208 a conditional subpattern that could match an empty string if that
1058 ph10 206 subpattern was within another subpattern. For example, it looped when
1059 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1060 ph10 206 condition was not nested. This bug has been fixed.
1061 ph10 208
1062 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1063     past the start of the subject in the presence of bytes with the top bit
1064     set, for example "\x8aBCD".
1065 ph10 211
1066 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1067     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1068 ph10 200
1069 ph10 211 14. Optimized (?!) to (*FAIL).
1070 ph10 202
1071 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1072     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1073     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1074     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1075     does: it's just the validity check that is more restrictive.
1076 ph10 220
1077     16. Inserted checks for integer overflows during escape sequence (backslash)
1078     processing, and also fixed erroneous offset values for syntax errors during
1079     backslash processing.
1081 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1082 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1084 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1085     caused an overrun.
1086 ph10 220
1087     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1088     something other than just ASCII characters) inside a group that had an
1089     unlimited repeat caused a loop at compile time (while checking to see
1090     whether the group could match an empty string).
1092 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1093     [\P{Any}] did so. (Error in the code for printing property names.)
1094 ph10 210
1095 ph10 220 21. An orphan \E inside a character class could cause a crash.
1097     22. A repeated capturing bracket such as (A)? could cause a wild memory
1098 ph10 218 reference during compilation.
1099 ph10 220
1100     23. There are several functions in pcre_compile() that scan along a compiled
1101     expression for various reasons (e.g. to see if it's fixed length for look
1102 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1103 ph10 220 present in the pattern. These operators have additional parameters compared
1104     with \d, etc, and these were not being taken into account when moving along
1105 ph10 218 the compiled data. Specifically:
1106 ph10 220
1107     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1108     length.
1110     (b) An item such as \pL+ within a repeated group could cause crashes or
1111 ph10 218 loops.
1112 ph10 220
1113 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1114 ph10 220 "reference to non-existent subpattern" error.
1116 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1118 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1119 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1120 ph10 211
1121 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1122 ph10 218
1123 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1124 ph10 223 character were causing crashes (broken optimization).
1125 ph10 227
1126 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1127 ph10 227 \p or \P) caused a compile-time loop.
1129 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1130     break. For example, the unstudied pattern [\r\n]A does not match the string
1131     "\r\nA" because change 7.0/46 below moves the current point on by two
1132     characters after failing to match at the start. However, the pattern \nA
1133 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1134     the same is true. There doesn't seem any very clean way out of this, but
1135     what I have chosen to do makes the common cases work: PCRE now takes note
1136     of whether there can be an explicit match for \r or \n anywhere in the
1137     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1138     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1139     pattern has explicit CR or LF references.
1140 ph10 222
1141 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1142 ph10 223
1143 ph10 227
1144 ph10 189 Version 7.2 19-Jun-07
1145     ---------------------
1147 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1148     which is apparently normally available under Windows.
1149 ph10 159
1150     2. Re-jig the pcregrep tests with different newline settings in an attempt
1151     to make them independent of the local environment's newline setting.
1152 ph10 157
1153 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1154 ph10 165
1155 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1156     was not 2, because the output contained actual offsets. The recent new
1157 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1158     usable with all link sizes.
1160 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1161     stack recursion. This gives a massive performance boost under BSD, but just
1162 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1163 ph10 164 in all cases.
1164 ph10 172
1165 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1166 ph10 172
1167 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1168     recursion call. It refers to the nth most recently opened parentheses.
1169 ph10 172
1170 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1171 ph10 172 to be opened parentheses.
1173     (c) Conditions that refer to capturing parentheses can be specified
1174 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1175 ph10 172
1176 ph10 168 (d) \K resets the start of the current match so that everything before
1177 ph10 172 is not part of it.
1179 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1180 ph10 172
1181 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1182 ph10 172 reference syntax.
1183 ph10 182
1184 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1185 ph10 182 alternative starts with the same number.
1186 ph10 172
1187 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1189 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1192     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1193     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1194 ph10 170 for detecting groups that can match an empty string.
1195 ph10 159
1196 ph10 172 9. A pattern with a very large number of alternatives (more than several
1197     hundred) was running out of internal workspace during the pre-compile
1198     phase, where pcre_compile() figures out how much memory will be needed. A
1199     bit of new cunning has reduced the workspace needed for groups with
1200     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1201     workspace instead of running out of the 4096 that are available.
1202 ph10 182
1203 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1204 ph10 172
1205 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1206     The report of the bug said:
1207 ph10 182
1208 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1209     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1210 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1211 ph10 185
1212 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1213 ph10 185 it matched the wrong number of bytes.
1214 ph10 172
1215 ph10 179
1216 ph10 155 Version 7.1 24-Apr-07
1217 ph10 98 ---------------------
1219 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1220 ph10 122 that is more "standard", making use of automake and other Autotools. There
1221 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1222     on this.
1223 ph10 111
1224     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1225     for recursive directory scanning broke on some systems because the files
1226     are not scanned in any specific order and on different systems the order
1227     was different. A call to "sort" has been inserted into RunGrepTest for the
1228     approprate test as a short-term fix. In the longer term there may be an
1229 ph10 100 alternative.
1230 ph10 111
1231 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1232 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1233     people do their own conversions for various reasons). The problems
1234     concerned the use of low-level troff macros .br and .in. I have therefore
1235     removed all such uses from the man pages (some were redundant, some could
1236 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1237     HTML has been updated to handle .nf/.fi and to complain if it encounters
1238     .br or .in.
1239 ph10 111
1240 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1241 ph10 123 arranged for config.h to be included in the distribution, with the name
1242 ph10 111 config.h.generic, for the benefit of those who have to compile without
1243     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1245     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1246     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1247 ph10 127 makevp.bat for the current PCRE, using the additional files
1248 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1249 ph10 111
1250     6. A Windows user reported a minor discrepancy with test 2, which turned out
1251     to be caused by a trailing space on an input line that had got lost in his
1252 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1253 ph10 111
1254 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1255 ph10 111 that is needed.
1257 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1258     as "const" (a) because they are and (b) because it helps the PHP
1259     maintainers who have recently made a script to detect big data structures
1260 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1261     to update Builducptable as well, so it won't revert if ucptable.h is ever
1262 ph10 105 re-created.
1263 ph10 111
1264     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1265 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1266 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1267     support is not required. This saves 1.5-2K of code, which is important in
1268 ph10 107 some applications.
1269 ph10 111
1270 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1271 ph10 111 so as not to refer to the tables, even though these functions will never be
1272     called when UTF-8 support is disabled. Otherwise there are problems with a
1273     shared library.
1275 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1277     (a) It was defining its arguments as char * instead of void *.
1279 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1280     a long time ago when I wrote it, but is no longer the case.
1282 ph10 118 The emulated memove() is provided for those environments that have neither
1283 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1284 ph10 118 is clearly not the case, as these two bugs were recently reported.
1285 ph10 123
1286 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1287 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1288     pages, and it removes trailing spaces from listed files. It also creates
1289     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1290     case, it wraps all the #defines with #ifndefs. This script should be run
1291 ph10 111 before "make dist".
1292 ph10 123
1293 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1294     with Unicode property support.
1295 ph10 123
1296     (a) For a maximizing quantifier, if the two different cases of the
1297     character were of different lengths in their UTF-8 codings (there are
1298     some cases like this - I found 11), and the matching function had to
1299 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1300     were both the same length.
1301 ph10 123
1302     (b) When PCRE was configured to use the heap rather than the stack for
1303     recursion during matching, it was not correctly preserving the data for
1304     the other case of a UTF-8 character when checking ahead for a match
1305     while processing a minimizing repeat. If the check also involved
1306 ph10 115 matching a wide character, but failed, corruption could cause an
1307     erroneous result when trying to check for a repeat of the original
1308     character.
1309 ph10 123
1310 ph10 116 13. Some tidying changes to the testing mechanism:
1311 ph10 98
1312 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1313     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1314 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1315     this for UTF-8.) The configure.ac script no longer substitutes the
1316     relevant variables.
1318 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1319     with length and offset values. This means that the output is different
1320     for different internal link sizes. Test 2 is skipped for link sizes
1321     other than 2 because of this, bypassing the problem. Unfortunately,
1322     there was also a test in test 3 (the locale tests) that used /B and
1323 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1324     I have added a new /Z option to pcretest that replaces the length and
1325     offset values with spaces. This is now used to make test 3 independent
1326 ph10 122 of link size. (Test 2 will be tidied up later.)
1327 ph10 123
1328     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1329 ph10 122 segmentation fault instead of returning the appropriate error message.
1330 ph10 134
1331 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1332 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1333     This doesn't seem right; it now treats the CRLF combination as the line
1334     ending, and so does not match in that case. It's only a pattern such as ^$
1335     that would hit this one: something like ^ABC$ would have failed after \r
1336     and then tried again after \r\n.
1338 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1339 ph10 134 in an attempt to make files that differ only in their line terminators
1340     compare equal. This works on Linux.
1341 ph10 142
1342 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1343     as it exited. This is now fixed, thanks to valgrind.
1344 ph10 142
1345 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1346 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1347     was because its rules for how to advance for /g after matching an empty
1348 ph10 143 string at the end of a line did not allow for this case. They now check for
1349     it specially.
1350 ph10 150
1351     20. pcretest is supposed to handle patterns and data of any length, by
1352     extending its buffers when necessary. It was getting this wrong when the
1353 ph10 147 buffer for a data line had to be extended.
1354 ph10 150
1355 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1356 ph10 150 CRLF as a newline sequence.
1357 ph10 152
1358 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1359 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1360     I have nevertheless tidied it up.
1361 ph10 111
1362 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1363 ph10 123
1364 ph10 153 24. Added a man page for pcre-config.
1365 ph10 152
1366 ph10 153
1367 nigel 93 Version 7.0 19-Dec-06
1368     ---------------------
1370     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1371     moving to gcc 4.1.1.
1373     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1374     sys/time.h, which is documented as needed for this function. It doesn't
1375     seem to matter on Linux, but it showed up on some releases of OS X.
1377     3. It seems that there are systems where bytes whose values are greater than
1378     127 match isprint() in the "C" locale. The "C" locale should be the
1379     default when a C program starts up. In most systems, only ASCII printing
1380     characters match isprint(). This difference caused the output from pcretest
1381     to vary, making some of the tests fail. I have changed pcretest so that:
1383     (a) When it is outputting text in the compiled version of a pattern, bytes
1384     other than 32-126 are always shown as hex escapes.
1386     (b) When it is outputting text that is a matched part of a subject string,
1387     it does the same, unless a different locale has been set for the match
1388     (using the /L modifier). In this case, it uses isprint() to decide.
1390     4. Fixed a major bug that caused incorrect computation of the amount of memory
1391     required for a compiled pattern when options that changed within the
1392     pattern affected the logic of the preliminary scan that determines the
1393     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1394     that the computed length was too small. The symptoms of this bug were
1395     either the PCRE error "internal error: code overflow" from pcre_compile(),
1396     or a glibc crash with a message such as "pcretest: free(): invalid next
1397     size (fast)". Examples of patterns that provoked this bug (shown in
1398     pcretest format) are:
1400     /(?-x: )/x
1401     /(?x)(?-x: \s*#\s*)/
1402     /((?i)[\x{c0}])/8
1403     /(?i:[\x{c0}])/8
1405     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1406     is now done differently.
1408     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1409     wrapper classes; (b) implement a new function in the C++ scanner that is
1410     more efficient than the old way of doing things because it avoids levels of
1411     recursion in the regex matching; (c) add a paragraph to the documentation
1412     for the FullMatch() function.
1414     6. The escape sequence \n was being treated as whatever was defined as
1415     "newline". Not only was this contrary to the documentation, which states
1416     that \n is character 10 (hex 0A), but it also went horribly wrong when
1417     "newline" was defined as CRLF. This has been fixed.
1419     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1420     was being set to -1 for the "end of line" case (supposedly a value that no
1421     character can have). Though this value is never used (the check for end of
1422     line is "zero bytes in current character"), it caused compiler complaints.
1423     I've changed it to 0xffffffff.
1425     8. In pcre_version.c, the version string was being built by a sequence of
1426     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1427     string (as it is for production releases) called a macro with an empty
1428     argument. The C standard says the result of this is undefined. The gcc
1429     compiler treats it as an empty string (which was what was wanted) but it is
1430     reported that Visual C gives an error. The source has been hacked around to
1431     avoid this problem.
1433     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1434     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1435     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1436     of them did).
1438     10. Originally, pcretest opened its input and output without "b"; then I was
1439     told that "b" was needed in some environments, so it was added for release
1440     5.0 to both the input and output. (It makes no difference on Unix-like
1441     systems.) Later I was told that it is wrong for the input on Windows. I've
1442     now abstracted the modes into two macros, to make it easier to fiddle with
1443     them, and removed "b" from the input mode under Windows.
1445     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1447     12. Added -help and --help to pcretest as an official way of being reminded
1448     of the options.
1450     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1451     and pcrecpp.cc because they annoy compilers at high warning levels.
1453     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1455     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1456     scripts are not C programs :-) and which was not noticed because it works
1457     on Linux.
1459     16. pcretest is supposed to handle any length of pattern and data line (as one
1460     line or as a continued sequence of lines) by extending its input buffer if
1461     necessary. This feature was broken for very long pattern lines, leading to
1462     a string of junk being passed to pcre_compile() if the pattern was longer
1463     than about 50K.
1465     17. I have done a major re-factoring of the way pcre_compile() computes the
1466     amount of memory needed for a compiled pattern. Previously, there was code
1467     that made a preliminary scan of the pattern in order to do this. That was
1468     OK when PCRE was new, but as the facilities have expanded, it has become
1469     harder and harder to keep it in step with the real compile phase, and there
1470     have been a number of bugs (see for example, 4 above). I have now found a
1471     cunning way of running the real compile function in a "fake" mode that
1472     enables it to compute how much memory it would need, while actually only
1473     ever using a few hundred bytes of working memory and without too many
1474     tests of the mode. This should make future maintenance and development
1475     easier. A side effect of this work is that the limit of 200 on the nesting
1476     depth of parentheses has been removed (though this was never a serious
1477     limitation, I suspect). However, there is a downside: pcre_compile() now
1478     runs more slowly than before (30% or more, depending on the pattern). I
1479     hope this isn't a big issue. There is no effect on runtime performance.
1481     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1482     newline (only possible for the last line of a file) and it was a
1483     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1485     19. Added additional timing features to pcretest. (1) The -tm option now times
1486     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1487     separate command line item, by a number that specifies the number of
1488     repeats to use when timing. The default is 50000; this gives better
1489     precision, but takes uncomfortably long for very large patterns.
1491     20. Extended pcre_study() to be more clever in cases where a branch of a
1492     subpattern has no definite first character. For example, (a*|b*)[cd] would
1493     previously give no result from pcre_study(). Now it recognizes that the
1494     first character must be a, b, c, or d.
1496     21. There was an incorrect error "recursive call could loop indefinitely" if
1497     a subpattern (or the entire pattern) that was being tested for matching an
1498     empty string contained only one non-empty item after a nested subpattern.
1499     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1500     incorrectly, because the \d was being skipped in the check.
1502     22. The pcretest program now has a new pattern option /B and a command line
1503     option -b, which is equivalent to adding /B to every pattern. This causes
1504     it to show the compiled bytecode, without the additional information that
1505     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1506     is the same as /B/I).
1508     23. A new optimization is now able automatically to treat some sequences such
1509     as a*b as a*+b. More specifically, if something simple (such as a character
1510     or a simple class like \d) has an unlimited quantifier, and is followed by
1511     something that cannot possibly match the quantified thing, the quantifier
1512     is automatically "possessified".
1514     24. A recursive reference to a subpattern whose number was greater than 39
1515     went wrong under certain circumstances in UTF-8 mode. This bug could also
1516     have affected the operation of pcre_study().
1518     25. Realized that a little bit of performance could be had by replacing
1519     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1521     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1523     27. Possessive quantifiers such as a++ were previously implemented by turning
1524     them into atomic groups such as ($>a+). Now they have their own opcodes,
1525     which improves performance. This includes the automatically created ones
1526     from 23 above.
1528     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1529     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1530     the first matched character to be a colon. This applied both to named and
1531     numbered groups.
1533     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1535     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1536     building PCRE on Windows easier, so I have included it in the distribution.
1538     31. There is now a check in pcretest against a ridiculously large number being
1539     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1540     loop, the loop is abandoned.
1542     32. Forward references to subpatterns in conditions such as (?(2)...) where
1543     subpattern 2 is defined later cause pcre_compile() to search forwards in
1544     the pattern for the relevant set of parentheses. This search went wrong
1545     when there were unescaped parentheses in a character class, parentheses
1546     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1548     33. "Subroutine" calls and backreferences were previously restricted to
1549     referencing subpatterns earlier in the regex. This restriction has now
1550     been removed.
1552     34. Added a number of extra features that are going to be in Perl 5.10. On the
1553     whole, these are just syntactic alternatives for features that PCRE had
1554     previously implemented using the Python syntax or my own invention. The
1555     other formats are all retained for compatibility.
1557     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1558     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1559     also .NET compatible.
1561     (b) A recursion or subroutine call to a named group can now be defined as
1562     (?&name) as well as (?P>name).
1564     (c) A backreference to a named group can now be defined as \k<name> or
1565     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1566     5.10, are also .NET compatible.
1568     (d) A conditional reference to a named group can now use the syntax
1569     (?(<name>) or (?('name') as well as (?(name).
1571     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1572     groups (named and numbered) that are never evaluated inline, but can be
1573     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1574     is always false. There may be only one alternative in such a group.
1576     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1577     as the simple (?(R). The condition is true only if the most recent
1578     recursion is that of the given number or name. It does not search out
1579     through the entire recursion stack.
1581     (g) The escape \gN or \g{N} has been added, where N is a positive or
1582     negative number, specifying an absolute or relative reference.
1584     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1585     some "unreachable code" warnings.
1587     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1588     things, this adds five new scripts.
1590     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1591     There were also incompatibilities regarding the handling of \Q..\E inside
1592     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1593     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1595     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1596     matches an empty string, and forcibly breaks the loop. There were bugs in
1597     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1598     against aaaa the result was just "a" rather than "aaaa", for example. Two
1599     separate and independent bugs (that affected different cases) have been
1600     fixed.
1602     39. Refactored the code to abolish the use of different opcodes for small
1603     capturing bracket numbers. This is a tidy that I avoided doing when I
1604     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1605     The new approach is not only tidier, it makes it possible to reduce the
1606     memory needed to fix the previous bug (38).
1608     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1609     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1610     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1611     mode.
1613     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1614     report.
1616     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1617     copy construction and assignment in the C++ wrapper.
1619     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1620     couple of bugs that could have given wrong results in the "--newline=crlf"
1621     case.
1623     44. Added a number of casts and did some reorganization of signed/unsigned int
1624     variables following suggestions from Dair Grant. Also renamed the variable
1625     "this" as "item" because it is a C++ keyword.
1627     45. Arranged for dftables to add
1629     #include "pcre_internal.h"
1631     to pcre_chartables.c because without it, gcc 4.x may remove the array
1632     definition from the final binary if PCRE is built into a static library and
1633     dead code stripping is activated.
1635     46. For an unanchored pattern, if a match attempt fails at the start of a
1636     newline sequence, and the newline setting is CRLF or ANY, and the next two
1637     characters are CRLF, advance by two characters instead of one.
1640 nigel 91 Version 6.7 04-Jul-06
1641     ---------------------
1643     1. In order to handle tests when input lines are enormously long, pcretest has
1644     been re-factored so that it automatically extends its buffers when
1645     necessary. The code is crude, but this _is_ just a test program. The
1646     default size has been increased from 32K to 50K.
1648     2. The code in pcre_study() was using the value of the re argument before
1649     testing it for NULL. (Of course, in any sensible call of the function, it
1650     won't be NULL.)
1652     3. The memmove() emulation function in pcre_internal.h, which is used on
1653     systems that lack both memmove() and bcopy() - that is, hardly ever -
1654     was missing a "static" storage class specifier.
1656     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1657     containing an extended class (one that cannot be represented by a bitmap
1658     because it contains high-valued characters or Unicode property items, e.g.
1659     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1660     pattern, but PCRE should not loop if you do not (it no longer does).
1661     [Detail: two cases were found: (a) a repeated subpattern containing an
1662     extended class; (b) a recursive reference to a subpattern that followed a
1663     previous extended class. It wasn't skipping over the extended class
1664     correctly when UTF-8 mode was not set.]
1666     5. A negated single-character class was not being recognized as fixed-length
1667     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1668     compile error "lookbehind assertion is not fixed length".
1670     6. The RunPerlTest auxiliary script was showing an unexpected difference
1671     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1672     write a Perl script that can interpret lines of an input file either as
1673     byte characters or as UTF-8, which is what "perltest" was being required to
1674     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1675     can't do is switch easily at run time between having the "use utf8;" pragma
1676     or not. In the end, I fudged it by using the RunPerlTest script to insert
1677     "use utf8;" explicitly for the UTF-8 tests.
1679     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1680     the end of the subject string, contrary to the documentation and to what
1681     Perl does. This was true of both matching functions. Now it matches only at
1682     the start of the subject and immediately after *internal* newlines.
1684     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1685     a pointer to an int instead of a pointer to an unsigned long int. This
1686     caused problems on 64-bit systems.
1688     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1689     instance of the 'standard' template library not being so standard".
1691     10. There was no check on the number of named subpatterns nor the maximum
1692     length of a subpattern name. The product of these values is used to compute
1693     the size of the memory block for a compiled pattern. By supplying a very
1694     long subpattern name and a large number of named subpatterns, the size
1695     computation could be caused to overflow. This is now prevented by limiting
1696     the length of names to 32 characters, and the number of named subpatterns
1697     to 10,000.
1699     11. Subpatterns that are repeated with specific counts have to be replicated in
1700     the compiled pattern. The size of memory for this was computed from the
1701     length of the subpattern and the repeat count. The latter is limited to
1702     65535, but there was no limit on the former, meaning that integer overflow
1703     could in principle occur. The compiled length of a repeated subpattern is
1704     now limited to 30,000 bytes in order to prevent this.
1706     12. Added the optional facility to have named substrings with the same name.
1708     13. Added the ability to use a named substring as a condition, using the
1709     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1710     are numbers (not recommended). Forward references are permitted.
1712     14. Added forward references in named backreferences (if you see what I mean).
1714     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1715     pattern could run off the end of the subject. For example, the pattern
1716     "(?s)(.{1,5})"8 did this with the subject "ab".
1718     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1719     PCRE_CASELESS was set when matching characters that were quantified with ?
1720     or *.
1722     17. A character class other than a single negated character that had a minimum
1723     but no maximum quantifier - for example [ab]{6,} - was not handled
1724     correctly by pce_dfa_exec(). It would match only one character.
1726     18. A valid (though odd) pattern that looked like a POSIX character
1727     class but used an invalid character after [ (for example [[,abc,]]) caused
1728     pcre_compile() to give the error "Failed: internal error: code overflow" or
1729     in some cases to crash with a glibc free() error. This could even happen if
1730     the pattern terminated after [[ but there just happened to be a sequence of
1731     letters, a binary zero, and a closing ] in the memory that followed.
1733     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1734     over the years. Originally (before any Unicode support), just the bottom 8
1735     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1736     output from "man perlunicode" includes this:
1738     The regular expression compiler produces polymorphic opcodes. That
1739     is, the pattern adapts to the data and automatically switches to
1740     the Unicode character scheme when presented with Unicode data--or
1741     instead uses a traditional byte scheme when presented with byte
1742     data.
1744     Sadly, a wide octal escape does not cause a switch, and in a string with
1745     no other multibyte characters, these octal escapes are treated as before.
1746     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1747     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1748     Unicode string.
1750     I have not perpetrated such confusion in PCRE. Up till now, it took just
1751     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1752     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1753     translate to the appropriate multibyte character.
1755     29. Applied some refactoring to reduce the number of warnings from Microsoft
1756     and Borland compilers. This has included removing the fudge introduced
1757     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1758     a warning about an unused variable.
1760     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1761     characters since release 4.0, because Perl (from release 5.004) does not.
1762     [Or at least, is documented not to: some releases seem to be in conflict
1763     with the documentation.] However, when a pattern was studied with
1764     pcre_study() and all its branches started with \s, PCRE still included VT
1765     as a possible starting character. Of course, this did no harm; it just
1766     caused an unnecessary match attempt.
1768     22. Removed a now-redundant internal flag bit that recorded the fact that case
1769     dependency changed within the pattern. This was once needed for "required
1770     byte" processing, but is no longer used. This recovers a now-scarce options
1771     bit. Also moved the least significant internal flag bit to the most-
1772     significant bit of the word, which was not previously used (hangover from
1773     the days when it was an int rather than a uint) to free up another bit for
1774     the future.
1776     23. Added support for CRLF line endings as well as CR and LF. As well as the
1777     default being selectable at build time, it can now be changed at runtime
1778     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1779     specify that it is scanning data with non-default line endings.
1781     24. Changed the definition of CXXLINK to make it agree with the definition of
1782     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1784     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1785     recursions. This makes a big different to stack usage for some patterns.
1787     26. If a subpattern containing a named recursion or subroutine reference such
1788     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1789     the space required for the compiled pattern went wrong and gave too small a
1790     value. Depending on the environment, this could lead to "Failed: internal
1791     error: code overflow at offset 49" or "glibc detected double free or
1792     corruption" errors.
1794     27. Applied patches from Google (a) to support the new newline modes and (b) to
1795     advance over multibyte UTF-8 characters in GlobalReplace.
1797     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1798     difference for some implementation of PCRE in some Windows version.
1800     29. Added some extra testing facilities to pcretest:
1802     \q<number> in a data line sets the "match limit" value
1803     \Q<number> in a data line sets the "match recursion limt" value
1804     -S <number> sets the stack size, where <number> is in megabytes
1806     The -S option isn't available for Windows.
1809 nigel 89 Version 6.6 06-Feb-06
1810     ---------------------
1812     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1813     in pcreposix.h. I have copied the definition from pcre.h.
1815     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1816     because pcre.h is no longer a built file.
1818     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1819     not normally included in the compiled code.
1822 nigel 87 Version 6.5 01-Feb-06
1823     ---------------------
1825     1. When using the partial match feature with pcre_dfa_exec(), it was not
1826     anchoring the second and subsequent partial matches at the new starting
1827     point. This could lead to incorrect results. For example, with the pattern
1828     /1234/, partially matching against "123" and then "a4" gave a match.
1830     2. Changes to pcregrep:
1832     (a) All non-match returns from pcre_exec() were being treated as failures
1833     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1834     error message is output. Some extra information is given for the
1836     probably the only errors that are likely to be caused by users (by
1837     specifying a regex that has nested indefinite repeats, for instance).
1838     If there are more than 20 of these errors, pcregrep is abandoned.
1840     (b) A binary zero was treated as data while matching, but terminated the
1841     output line if it was written out. This has been fixed: binary zeroes
1842     are now no different to any other data bytes.
1844     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1845     used to set a locale for matching. The --locale=xxxx long option has
1846     been added (no short equivalent) to specify a locale explicitly on the
1847     pcregrep command, overriding the environment variables.
1849     (d) When -B was used with -n, some line numbers in the output were one less
1850     than they should have been.
1852     (e) Added the -o (--only-matching) option.
1854     (f) If -A or -C was used with -c (count only), some lines of context were
1855     accidentally printed for the final match.
1857     (g) Added the -H (--with-filename) option.
1859     (h) The combination of options -rh failed to suppress file names for files
1860     that were found from directory arguments.
1862     (i) Added the -D (--devices) and -d (--directories) options.
1864     (j) Added the -F (--fixed-strings) option.
1866     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1868     (l) Added the --colo(u)r option.
1870     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1871     is not present by default.
1873     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1874     items such as (?R) or (?1), when the recursion could match a number of
1875     alternatives. If it matched one of the alternatives, but subsequently,
1876     outside the recursion, there was a failure, the code tried to back up into
1877     the recursion. However, because of the way PCRE is implemented, this is not
1878     possible, and the result was an incorrect result from the match.
1880     In order to prevent this happening, the specification of recursion has
1881     been changed so that all such subpatterns are automatically treated as
1882     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1884     4. I had overlooked the fact that, in some locales, there are characters for
1885     which isalpha() is true but neither isupper() nor islower() are true. In
1886     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1887     and ordfeminine) are like this. This affected the treatment of \w and \W
1888     when they appeared in character classes, but not when they appeared outside
1889     a character class. The bit map for "word" characters is now created
1890     separately from the results of isalnum() instead of just taking it from the
1891     upper, lower, and digit maps. (Plus the underscore character, of course.)
1893     5. The above bug also affected the handling of POSIX character classes such as
1894     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1895     permanent tables. Instead, the bit maps for such a class were previously
1896     created as the appropriate unions of the upper, lower, and digit bitmaps.
1897     Now they are created by subtraction from the [[:word:]] class, which has
1898     its own bitmap.
1900     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1901     It is created by subtracting the vertical space characters (\x09, \x0a,
1902     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1903     subtraction was done in the overall bitmap for a character class, meaning
1904     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1905     be recognized. This bug has been fixed.
1907     7. Patches from the folks at Google:
1909     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1910     real life, but is still worth protecting against".
1912     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1913     regular expressions".
1915     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1916     have it.
1918     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1919     "configure" and the latter not, in order to fix a problem somebody had
1920     with compiling the Arg class on HP-UX.
1922     (e) Improve the error-handling of the C++ wrapper a little bit.
1924     (f) New tests for checking recursion limiting.
1926     8. The pcre_memmove() function, which is used only if the environment does not
1927     have a standard memmove() function (and is therefore rarely compiled),
1928     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1929     returning a result (though PCRE never actually uses the result).
1931     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1932     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1933     returned instead of calling malloc() with an overflowing number that would
1934     most likely cause subsequent chaos.
1936     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1938     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1939     with this option is matched, the nmatch and pmatch options of regexec() are
1940     ignored.
1942     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1943     provided in case anyone wants to the the POSIX interface with UTF-8
1944     strings.
1946     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1947     C++ linking (needed for some HP-UX environments).
1949     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1950     (unused parameter) and in the pcre_printint() function (omitted "default"
1951     switch label when the default is to do nothing).
1953     15. Added some code to make it possible, when PCRE is compiled as a C++
1954     library, to replace subject pointers for pcre_exec() with a smart pointer
1955     class, thus making it possible to process discontinuous strings.
1957     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1958     much the same function. They were added by different people who were trying
1959     to make PCRE easy to compile on non-Unix systems. It has been suggested
1960     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1961     for compiling on Windows systems. I have therefore replaced it with
1962     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1963     defaults to "extern" for C or "extern C" for C++, which works fine on
1964     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1965     SCOPE with something explicit in config.h. In addition:
1967     (a) pcreposix.h still had just "extern" instead of either of these macros;
1968     I have replaced it with PCRE_DATA_SCOPE.
1970     (b) Functions such as _pcre_xclass(), which are internal to the library,
1971     but external in the C sense, all had PCRE_EXPORT in their definitions.
1972     This is apparently wrong for the Windows case, so I have removed it.
1973     (It makes no difference on Unix-like systems.)
1975     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1976     of recursive calls to match(). This is different to MATCH_LIMIT because
1977     that limits the total number of calls to match(), not all of which increase
1978     the depth of recursion. Limiting the recursion depth limits the amount of
1979     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1980     when PCRE is compiled, and changed at run time. A patch from Google adds
1981     this functionality to the C++ interface.
1983     18. Changes to the handling of Unicode character properties:
1985     (a) Updated the table to Unicode 4.1.0.
1987     (b) Recognize characters that are not in the table as "Cn" (undefined).
1989     (c) I revised the way the table is implemented to a much improved format
1990     which includes recognition of ranges. It now supports the ranges that
1991     are defined in UnicodeData.txt, and it also amalgamates other
1992     characters into ranges. This has reduced the number of entries in the
1993     table from around 16,000 to around 3,000, thus reducing its size
1994     considerably. I realized I did not need to use a tree structure after
1995     all - a binary chop search is just as efficient. Having reduced the
1996     number of entries, I extended their size from 6 bytes to 8 bytes to
1997     allow for more data.
1999     (d) Added support for Unicode script names via properties such as \p{Han}.
2001     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2002     matching that character.
2004     20. When matching a repeated Unicode property with a minimum greater than zero,
2005     (for example \pL{2,}), PCRE could look past the end of the subject if it
2006     reached it while seeking the minimum number of characters. This could
2007     happen only if some of the characters were more than one byte long, because
2008     there is a check for at least the minimum number of bytes.
2010     21. Refactored the implementation of \p and \P so as to be more general, to
2011     allow for more different types of property in future. This has changed the
2012     compiled form incompatibly. Anybody with saved compiled patterns that use
2013     \p or \P will have to recompile them.
2015     22. Added "Any" and "L&" to the supported property types.
2017     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2018     but give a compile time error if the value is greater than 0xff.
2020     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2021     accidentally not being installed or uninstalled.
2023     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2024     made were to insert the current release number. This seemed silly, because
2025     it made things harder for people building PCRE on systems that don't run
2026     "configure". I have turned pcre.h into a distributed file, no longer built
2027     by "configure", with the version identification directly included. There is
2028     no longer a pcre.h.in file.
2030     However, this change necessitated a change to the pcre-config script as
2031     well. It is built from pcre-config.in, and one of the substitutions was the
2032     release number. I have updated configure.ac so that ./configure now finds
2033     the release number by grepping pcre.h.
2035     26. Added the ability to run the tests under valgrind.
2038 nigel 85 Version 6.4 05-Sep-05
2039     ---------------------
2041     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2042     "--" to be printed when multiple files were scanned, even when none of the
2043     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2044     consider it to be a bug, and have restored the previous behaviour.
2046     2. A couple of code tidies to get rid of compiler warnings.
2048     3. The pcretest program used to cheat by referring to symbols in the library
2049     whose names begin with _pcre_. These are internal symbols that are not
2050     really supposed to be visible externally, and in some environments it is
2051     possible to suppress them. The cheating is now confined to including
2052     certain files from the library's source, which is a bit cleaner.
2054     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2055     file's purpose clearer.
2057     5. Reorganized pcre_ucp_findchar().
2060 nigel 83 Version 6.3 15-Aug-05
2061     ---------------------
2063     1. The file libpcre.pc.in did not have general read permission in the tarball.
2065     2. There were some problems when building without C++ support:
2067     (a) If C++ support was not built, "make install" and "make test" still
2068     tried to test it.
2070     (b) There were problems when the value of CXX was explicitly set. Some
2071     changes have been made to try to fix these, and ...
2073     (c) --disable-cpp can now be used to explicitly disable C++ support.
2075     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2076     backslash in a target when C++ was disabled. This confuses some
2077     versions of "make", apparently. Using an intermediate variable solves
2078     this. (Same for CPP_LOBJ.)
2080     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2081     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2082     necessary on certain architectures.
2084     4. Added a setting of -export-symbols-regex to the link command to remove
2085     those symbols that are exported in the C sense, but actually are local
2086     within the library, and not documented. Their names all begin with
2087     "_pcre_". This is not a perfect job, because (a) we have to except some
2088     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2089     available (and never for static libraries). I have made a note to try to
2090     find a way round (a) in the future.
2093 nigel 81 Version 6.2 01-Aug-05
2094     ---------------------
2096     1. There was no test for integer overflow of quantifier values. A construction
2097     such as {1111111111111111} would give undefined results. What is worse, if
2098     a minimum quantifier for a parenthesized subpattern overflowed and became
2099     negative, the calculation of the memory size went wrong. This could have
2100     led to memory overwriting.
2102     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2104     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2105     operating environments where this matters.
2107     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2108     PCRE options from within the C++ wrapper.
2110     5. Named capturing subpatterns were not being correctly counted when a pattern
2111     was compiled. This caused two problems: (a) If there were more than 100
2112     such subpatterns, the calculation of the memory needed for the whole
2113     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2114     back references of the form \12, where the number was greater than 9, were
2115     not recognized as back references, even though there were sufficient
2116     previous subpatterns.
2118     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2119     versions of gcc, e.g. 2.95.4.
2122 nigel 79 Version 6.1 21-Jun-05
2123     ---------------------
2125     1. There was one reference to the variable "posix" in pcretest.c that was not
2126     surrounded by "#if !defined NOPOSIX".
2128     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2129     the cross-check on the old pcre_info() function, for the benefit of the
2130     cut-down version of PCRE that is currently imported into Exim.
2132     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2133     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2134     patterns that start (?i) but I don't think that matters. The use of (?i) is
2135     just an example; this all applies to the other options as well.
2137     4. Since libtool seems to echo the compile commands it is issuing, the output
2138     from "make" can be reduced a bit by putting "@" in front of each libtool
2139     compile command.
2141     5. Patch from the folks at Google for configure.in to be a bit more thorough
2142     in checking for a suitable C++ installation before trying to compile the
2143     C++ stuff. This should fix a reported problem when a compiler was present,
2144     but no suitable headers.
2146     6. The man pages all had just "PCRE" as their title. I have changed them to
2147     be the relevant file name. I have also arranged that these names are
2148     retained in the file doc/pcre.txt, which is a concatenation in text format
2149     of all the man pages except the little individual ones for each function.
2151     7. The NON-UNIX-USE file had not been updated for the different set of source
2152     files that come with release 6. I also added a few comments about the C++
2153     wrapper.
2156 nigel 77 Version 6.0 07-Jun-05
2157     ---------------------
2159     1. Some minor internal re-organization to help with my DFA experiments.
2161     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2162     didn't matter for the library itself when fully configured, but did matter
2163     when compiling without UCP support, or within Exim, where the ucp files are
2164     not imported.
2166     3. Refactoring of the library code to split up the various functions into
2167     different source modules. The addition of the new DFA matching code (see
2168     below) to a single monolithic source would have made it really too
2169     unwieldy, quite apart from causing all the code to be include in a
2170     statically linked application, when only some functions are used. This is
2171     relevant even without the DFA addition now that patterns can be compiled in
2172     one application and matched in another.
2174     The downside of splitting up is that there have to be some external
2175     functions and data tables that are used internally in different modules of
2176     the library but which are not part of the API. These have all had their
2177     names changed to start with "_pcre_" so that they are unlikely to clash
2178     with other external names.
2180     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2181     a different (DFA) algorithm. Although it is slower than the original
2182     function, it does have some advantages for certain types of matching
2183     problem.
2185     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2186     including restarting after a partial match.
2188     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2189     defined when compiling for Windows was sent to me. I have put it into the
2190     code, though I have no means of testing or verifying it.
2192     7. Added the pcre_refcount() auxiliary function.
2194     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2195     match before or at the first newline in the subject string. In pcretest,
2196     the /f option on a pattern can be used to set this.
2198     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2199     would behave wrongly. This has been present in PCRE since release 4.0.
2201     10. A number of changes to the pcregrep command:
2203     (a) Refactored how -x works; insert ^(...)$ instead of setting
2204     PCRE_ANCHORED and checking the length, in preparation for adding
2205     something similar for -w.
2207     (b) Added the -w (match as a word) option.
2209     (c) Refactored the way lines are read and buffered so as to have more
2210     than one at a time available.
2212     (d) Implemented a pcregrep test script.
2214     (e) Added the -M (multiline match) option. This allows patterns to match
2215     over several lines of the subject. The buffering ensures that at least
2216     8K, or the rest of the document (whichever is the shorter) is available
2217     for matching (and similarly the previous 8K for lookbehind assertions).
2219     (f) Changed the --help output so that it now says
2221     -w, --word-regex(p)
2223     instead of two lines, one with "regex" and the other with "regexp"
2224     because that confused at least one person since the short forms are the
2225     same. (This required a bit of code, as the output is generated
2226     automatically from a table. It wasn't just a text change.)
2228     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2229     option but starts with a hyphen. Could be a pattern or a path name
2230     starting with a hyphen, for instance.
2232     (h) "-" can be given as a file name to represent stdin.
2234     (i) When file names are being printed, "(standard input)" is used for
2235     the standard input, for compatibility with GNU grep. Previously
2236     "<stdin>" was used.
2238     (j) The option --label=xxx can be used to supply a name to be used for
2239     stdin when file names are being printed. There is no short form.
2241     (k) Re-factored the options decoding logic because we are going to add
2242     two more options that take data. Such options can now be given in four
2243     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2245     (l) Added the -A, -B, and -C options for requesting that lines of context
2246     around matches be printed.
2248     (m) Added the -L option to print the names of files that do not contain
2249     any matching lines, that is, the complement of -l.
2251     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2252     continue to scan other files.
2254     (o) The -s option was incorrectly implemented. For compatibility with other
2255     greps, it now suppresses the error message for a non-existent or non-
2256     accessible file (but not the return code). There is a new option called
2257     -q that suppresses the output of matching lines, which was what -s was
2258     previously doing.
2260     (p) Added --include and --exclude options to specify files for inclusion
2261     and exclusion when recursing.
2263     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2264     Hopefully, it now does.
2266     12. Missing cast in pcre_study().
2268     13. Added an "uninstall" target to the makefile.
2270     14. Replaced "extern" in the function prototypes in Makefile.in with
2271     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2272     world, but is set differently for Windows.
2274     15. Added a second compiling function called pcre_compile2(). The only
2275     difference is that it has an extra argument, which is a pointer to an
2276     integer error code. When there is a compile-time failure, this is set
2277     non-zero, in addition to the error test pointer being set to point to an
2278     error message. The new argument may be NULL if no error number is required
2279     (but then you may as well call pcre_compile(), which is now just a
2280     wrapper). This facility is provided because some applications need a
2281     numeric error indication, but it has also enabled me to tidy up the way
2282     compile-time errors are handled in the POSIX wrapper.
2284     16. Added VPATH=.libs to the makefile; this should help when building with one
2285     prefix path and installing with another. (Or so I'm told by someone who
2286     knows more about this stuff than I do.)
2288     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2289     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2290     match everything, including newlines. This is not POSIX-compatible, but
2291     somebody wanted the feature. From pcretest it can be activated by using
2292     both the P and the s flags.
2294     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2296     19. libpcre.pc was being incorrectly installed as executable.
2298     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2299     it now also looks for '\r' so that it will work unmodified on Windows.
2301     21. Added Google's contributed C++ wrapper to the distribution.
2303     22. Added some untidy missing memory free() calls in pcretest, to keep
2304     Electric Fence happy when testing.
2308 nigel 75 Version 5.0 13-Sep-04
2309     ---------------------
2311     1. Internal change: literal characters are no longer packed up into items
2312     containing multiple characters in a single byte-string. Each character
2313     is now matched using a separate opcode. However, there may be more than one
2314     byte in the character in UTF-8 mode.
2316     2. The pcre_callout_block structure has two new fields: pattern_position and
2317     next_item_length. These contain the offset in the pattern to the next match
2318     item, and its length, respectively.
2320     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2321     insertion of callouts before each pattern item. Added the /C option to
2322     pcretest to make use of this.
2324     4. On the advice of a Windows user, the lines
2326     #if defined(_WIN32) || defined(WIN32)
2327     _setmode( _fileno( stdout ), 0x8000 );
2328     #endif /* defined(_WIN32) || defined(WIN32) */
2330     have been added to the source of pcretest. This apparently does useful
2331     magic in relation to line terminators.
2333     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2334     for the benefit of those environments where the "b" makes a difference.
2336     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2337     to know about it. I have put a hack into configure.in that adds in code
2338     to set GCC=yes if CC=icc. This seems to end up at a point in the
2339     generated configure script that is early enough to affect the setting of
2340     compiler options, which is what is needed, but I have no means of testing
2341     whether it really works. (The user who reported this had patched the
2342     generated configure script, which of course I cannot do.)
2344     LATER: After change 22 below (new libtool files), the configure script
2345     seems to know about icc (and also ecc). Therefore, I have commented out
2346     this hack in configure.in.
2348     7. Added support for pkg-config (2 patches were sent in).
2350     8. Negated POSIX character classes that used a combination of internal tables
2351     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2352     [[:^ascii]]. Typically, they would match almost any characters. The other
2353     POSIX classes were not broken in this way.
2355     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2356     to find the match, as PCRE was deluded into thinking that the match had to
2357     start at the start point or following a newline. The same bug applied to
2358     patterns with negative forward assertions or any backward assertions
2359     preceding ".*" at the start, unless the pattern required a fixed first
2360     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2362     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2363     starting at the last subject character, bytes beyond the end of the subject
2364     string were read.
2366     11. Renamed the variable "class" as "classbits" to make life easier for C++
2367     users. (Previously there was a macro definition, but it apparently wasn't
2368     enough.)
2370     12. Added the new field "tables" to the extra data so that tables can be passed
2371     in at exec time, or the internal tables can be re-selected. This allows
2372     a compiled regex to be saved and re-used at a later time by a different
2373     program that might have everything at different addresses.
2375     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2376     -R library as well as a -L library.
2378     14. The debugging options of pcretest (-d on the command line or D on a
2379     pattern) showed incorrect output for anything following an extended class
2380     that contained multibyte characters and which was followed by a quantifier.
2382     15. Added optional support for general category Unicode character properties
2383     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2384     support. It adds about 90K to the size of the library. The meanings of the
2385     inbuilt class escapes such as \d and \s have NOT been changed.
2387     16. Updated pcredemo.c to include calls to free() to release the memory for the
2388     compiled pattern.
2390     17. The generated file chartables.c was being created in the source directory
2391     instead of in the building directory. This caused the build to fail if the
2392     source directory was different from the building directory, and was
2393     read-only.
2395     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2396     file. No doubt somebody will tell me if they don't make sense... Also added
2397     Dan Mooney's comments about building on OpenVMS.
2399     19. Added support for partial matching via the PCRE_PARTIAL option for
2400     pcre_exec() and the \P data escape in pcretest.
2402     20. Extended pcretest with 3 new pattern features:
2404     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2405     write the compiled pattern to the file whose name is "rest-of-line".
2406     This is a straight binary dump of the data, with the saved pointer to
2407     the character tables forced to be NULL. The study data, if any, is
2408     written too. After writing, pcretest reads a new pattern.
2410     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2411     compiled pattern from the given file. There must not be any
2412     occurrences of "<" in the file name (pretty unlikely); if there are,
2413     pcretest will instead treat the initial "<" as a pattern delimiter.
2414     After reading in the pattern, pcretest goes on to read data lines as
2415     usual.
2417     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2418     and 16-bit fields in a compiled pattern, to simulate a pattern that
2419     was compiled on a host of opposite endianness.
2421     21. The pcre-exec() function can now cope with patterns that were compiled on
2422     hosts of opposite endianness, with this restriction:
2424     As for any compiled expression that is saved and used later, the tables
2425     pointer field cannot be preserved; the extra_data field in the arguments
2426     to pcre_exec() should be used to pass in a tables address if a value
2427     other than the default internal tables were used at compile time.
2429     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2430     now diagnosed as an error. Previously, most of the time, a negative number
2431     would have been treated as zero, but if in addition "ovector" was passed as
2432     NULL, a crash could occur.
2434     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2435     new versions from the libtool 1.5 distribution (the last one is a copy of
2436     a file called libtool.m4). This seems to have fixed the need to patch
2437     "configure" to support Darwin 1.3 (which I used to do). However, I still
2438     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2439     workstation).
2441     24. Changed the PCRE licence to be the more standard "BSD" licence.
2444 nigel 73 Version 4.5 01-Dec-03
2445     ---------------------
2447     1. There has been some re-arrangement of the code for the match() function so
2448     that it can be compiled in a version that does not call itself recursively.
2449     Instead, it keeps those local variables that need separate instances for
2450     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2451     needs to "recurse". Keeping track of where control must go is done by means
2452     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2453     hide most of the details from the main code, and operates only if
2454     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2455     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2456     operating.
2458     To make it easier for callers to provide specially tailored get/free
2459     functions for this usage, two new functions, pcre_stack_malloc, and
2460     pcre_stack_free, are used. They are always called in strict stacking order,
2461     and the size of block requested is always the same.
2463     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2464     PCRE has been compiled to use the stack or the heap for recursion. The
2465     -C option of pcretest uses this to show which version is compiled.
2467     A new data escape \S, is added to pcretest; it causes the amounts of store
2468     obtained and freed by both kinds of malloc/free at match time to be added
2469     to the output.
2471     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2472     what's available on my current Linux desktop machine.
2474     3. When matching a UTF-8 string, the test for a valid string at the start has
2475     been extended. If start_offset is not zero, PCRE now checks that it points
2476     to a byte that is the start of a UTF-8 character. If not, it returns
2477     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2478     this is necessary because there may be backward assertions in the pattern.
2479     When matching the same subject several times, it may save resources to use
2480     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2482     4. The code for checking the validity of UTF-8 strings has been tightened so
2483     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2484     containing "overlong sequences".
2486     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2487     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2488     should have been "&", but it just so happened that all the cases this let
2489     through by mistake were picked up later in the function.
2491     6. I had used a variable called "isblank" - this is a C99 function, causing
2492     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2494     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2495     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2496     so the version is shown; (c) stop "make test" echoing "./RunTest".
2498     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2500     9. The prototype for memmove() for systems that don't have it was using
2501     size_t, but the inclusion of the header that defines size_t was later. I've
2502     moved the #includes for the C headers earlier to avoid this.
2504     10. Added some adjustments to the code to make it easier to compiler on certain
2505     special systems:
2507     (a) Some "const" qualifiers were missing.
2508     (b) Added the macro EXPORT before all exported functions; by default this
2509     is defined to be empty.
2510     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2511     that it reads its output file name as an argument instead of writing
2512     to the standard output and assuming this can be redirected.
2514     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2515     class containing characters with values greater than 255, PCRE compilation
2516     went into a loop.
2518     12. A recursive reference to a subpattern that was within another subpattern
2519     that had a minimum quantifier of zero caused PCRE to crash. For example,
2520     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2521     recursion. If the recursively-called subpattern itself had a zero repeat,
2522     that was OK.
2524     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2525     buffer into which it was copied (for escape processing) was still set at
2526     1024, so long lines caused crashes.
2528     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2529     "internal error: code overflow...". This applied to any character class
2530     that was followed by a possessive quantifier.
2532     15. Modified the Makefile to add libpcre.la as a prerequisite for
2533     libpcreposix.la because I was told this is needed for a parallel build to
2534     work.
2536     16. If a pattern that contained .* following optional items at the start was
2537     studied, the wrong optimizing data was generated, leading to matching
2538     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2539     matching string must start with a or b or c. The correct conclusion for
2540     this pattern is that a match can start with any character.
2543 nigel 71 Version 4.4 13-Aug-03
2544     ---------------------
2546     1. In UTF-8 mode, a character class containing characters with values between
2547     127 and 255 was not handled correctly if the compiled pattern was studied.
2548     In fixing this, I have also improved the studying algorithm for such
2549     classes (slightly).
2551     2. Three internal functions had redundant arguments passed to them. Removal
2552     might give a very teeny performance improvement.
2554     3. Documentation bug: the value of the capture_top field in a callout is *one
2555     more than* the number of the hightest numbered captured substring.
2557     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2558     in incorrectly linking with a previously installed version. They now link
2559     explicitly with libpcre.la.
2561     5. configure.in no longer needs to recognize Cygwin specially.
2563     6. A problem in pcre.in for Windows platforms is fixed.
2565     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2566     pcretest, it used to include the size of the study block as part of its
2567     output. Unfortunately, the structure contains a field that has a different
2568     size on different hardware architectures. This meant that the tests that
2569     showed this size failed. As the block is currently always of a fixed size,
2570     this information isn't actually particularly useful in pcretest output, so
2571     I have just removed it.
2573     8. Three pre-processor statements accidentally did not start in column 1.
2574     Sadly, there are *still* compilers around that complain, even though
2575     standard C has not required this for well over a decade. Sigh.
2577     9. In pcretest, the code for checking callouts passed small integers in the
2578     callout_data field, which is a void * field. However, some picky compilers
2579     complained about the casts involved for this on 64-bit systems. Now
2580     pcretest passes the address of the small integer instead, which should get
2581     rid of the warnings.
2583     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2584     both compile and run time, and gives an error if an invalid UTF-8 sequence
2585     is found. There is a option for disabling this check in cases where the
2586     string is known to be correct and/or the maximum performance is wanted.
2588     11. In response to a bug report, I changed one line in Makefile.in from
2590     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2591     to
2592     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2594     to look similar to other lines, but I have no way of telling whether this
2595     is the right thing to do, as I do not use Windows. No doubt I'll get told
2596     if it's wrong...
2599 nigel 69 Version 4.3 21-May-03
2600     ---------------------
2602     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2603     Makefile.
2605     2. Some refactoring to improve the quality of the code:
2607     (i) The utf8_table... variables are now declared "const".
2609     (ii) The code for \cx, which used the "case flipping" table to upper case
2610     lower case letters, now just substracts 32. This is ASCII-specific,
2611     but the whole concept of \cx is ASCII-specific, so it seems
2612     reasonable.
2614     (iii) PCRE was using its character types table to recognize decimal and
2615     hexadecimal digits in the pattern. This is silly, because it handles
2616     only 0-9, a-f, and A-F, but the character types table is locale-
2617     specific, which means strange things might happen. A private
2618     table is now used for this - though it costs 256 bytes, a table is
2619     much faster than multiple explicit tests. Of course, the standard
2620     character types table is still used for matching digits in subject
2621     strings against \d.
2623     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2624     ending in _t are). So I've renamed it as ESC_tee.
2626     3. The first argument for regexec() in the POSIX wrapper should have been
2627     defined as "const".
2629     4. Changed pcretest to use malloc() for its buffers so that they can be
2630     Electric Fenced for debugging.
2632     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2633     to read one or more bytes before the start of the subject string. Often this
2634     had no effect on PCRE's behaviour, but in some circumstances it could
2635     provoke a segmentation fault.
2637     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2638     to try to read one or more bytes before the start of the subject string.
2640     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2641     UTF-8 support could misbehave in various ways if the subject string
2642     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2643     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2644     back over UTF-8 characters.)
2647 nigel 67 Version 4.2 14-Apr-03
2648     ---------------------
2650     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2652     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2653     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2654     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2655     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2656     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2657     and BUILD_EXEEXT
2658     Note: automatic setting of the BUILD variables is not yet working
2659     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2660     compile-time but not at link-time
2661     [LINK]: use for linking executables only
2662     make different versions for Windows and non-Windows
2663     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2664     libraries
2665     [LINK_FOR_BUILD]: new variable
2666     [OBJEXT]: use throughout
2667     [EXEEXT]: use throughout
2668     <winshared>: new target
2669     <wininstall>: new target
2670     <dftables.o>: use native compiler
2671     <dftables>: use native linker
2672     <install>: handle Windows platform correctly
2673     <clean>: ditto
2674     <check>: ditto
2675     copy DLL to top builddir before testing
2677     As part of these changes, -no-undefined was removed again. This was reported
2678     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2679     in any case.
2681     3. Some tidies to get rid of compiler warnings:
2683     . In the match_data structure, match_limit was an unsigned long int, whereas
2684     match_call_count was an int. I've made them both unsigned long ints.
2686     . In pcretest the fact that a const uschar * doesn't automatically cast to
2687     a void * provoked a warning.
2689     . Turning on some more compiler warnings threw up some "shadow" variables
2690     and a few more missing casts.
2692     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2693     option, a class that contained a single character with a value between 128
2694     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2696     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2697     option, a class that contained several characters, but with at least one
2698     whose value was between 128 and 255 caused PCRE to crash.
2701 nigel 65 Version 4.1 12-Mar-03
2702     ---------------------
2703 nigel 63
2704 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2705     needed, and a string in dftables.c that was longer than standard compilers are
2706     required to support.
2708     2. Compiling with Sun's compiler found a few more places where the code could
2709     be tidied up in order to avoid warnings.
2711     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2712     first of these names is deprecated in the latest Autoconf in favour of the name
2713     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2714     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2715     analogy I have changed it to CFLAGS_FOR_BUILD.
2717     4. Added -no-undefined to the linking command in the Makefile, because this is
2718     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2719     linking step for the pcreposix library.
2721     5. PCRE was failing to diagnose the case of two named groups with the same
2722     name.
2724     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2725     literal character that is needed in the subject for a match, and scans along to
2726     ensure that it is present before embarking on the full matching process. This
2727     saves time in cases of nested unlimited repeats that are never going to match.
2728     Problem: the scan can take a lot of time if the subject is very long (e.g.
2729     megabytes), thus penalizing straightforward matches. It is now done only if the
2730     amount of subject to be scanned is less than 1000 bytes.
2732     7. A lesser problem with the same optimization is that it was recording the
2733     first character of an anchored pattern as "needed", thus provoking a search
2734     right along the subject, even when the first match of the pattern was going to
2735     fail. The "needed" character is now not set for anchored patterns, unless it
2736     follows something in the pattern that is of non-fixed length. Thus, it still
2737     fulfils its original purpose of finding quick non-matches in cases of nested
2738     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2741     Version 4.0 17-Feb-03
2742     ---------------------
2744 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2745     extended to the end of string, PCRE compiled incorrect data. This could lead to
2746     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2748     2. Moved to autoconf 2.53 and libtool 1.4.2.
2750     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2751     the special perltest8 script is no longer needed - all the tests can be run
2752     from a single perltest script.
2754     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2755     by \s. It has now been removed in PCRE. This means it isn't recognized as
2756     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2757     class [:space:] *does* include VT, thereby creating a mess.
2759     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2760     space and tab.
2762     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2763     its new features into the main test script, reducing the number of scripts.
2765     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2766     were backward compatible, and made the (?i) apply to the whole pattern, as if
2767     /i were given. Now it behaves more logically, and applies the option setting
2768     only to what follows. PCRE has been changed to follow suit. However, if it
2769     finds options settings right at the start of the pattern, it extracts them into
2770     the global options, as before. Thus, they show up in the info data.
2772     8. Added support for the \Q...\E escape sequence. Characters in between are
2773     treated as literals. This is slightly different from Perl in that $ and @ are
2774     also handled as literals inside the quotes. In Perl, they will cause variable
2775     interpolation. Note the following examples:
2777     Pattern PCRE matches Perl matches
2779     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2780     \Qabc\$xyz\E abc\$xyz abc\$xyz
2781     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2783     For compatibility with Perl, \Q...\E sequences are recognized inside character
2784     classes as well as outside them.
2786     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2787     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2788     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2789     signed/unsigned warnings.
2791     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2792     option for pcretest, so I've replaced it by a simple function that does just
2793     that job.
2795     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2796     "pcregrep -".
2798     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2799     Java package. This provides some syntactic sugar for simple cases of what my
2800     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2801     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2802     item, you can use this simplified notation. Note that only makes sense with
2803     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2804     greediness, whatever the setting of the PCRE_UNGREEDY option.
2806     13. A change of greediness default within a pattern was not taking effect at
2807     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2808     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2809     was abstracted outside.
2811     14. PCRE now supports the \G assertion. It is true when the current matching
2812     position is at the start point of the match. This differs from \A when the
2813     starting offset is non-zero. Used with the /g option of pcretest (or similar
2814     code), it works in the same way as it does for Perl's /g option. If all
2815     alternatives of a regex begin with \G, the expression is anchored to the start
2816     match position, and the "anchored" flag is set in the compiled expression.
2818     15. Some bugs concerning the handling of certain option changes within patterns
2819     have been fixed. These applied to options other than (?ims). For example,
2820     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2821     been the other way round. Some of this was related to change 7 above.
2823     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2824     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2825     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2826     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2828     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2829     mode. Unlike ".", it always matches newline, whatever the setting of
2830     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2831     assertions. Perl allows it, but it doesn't (in general) work because it can't
2832     calculate the length of the lookbehind. At least, that's the case for Perl
2833     5.8.0 - I've been told they are going to document that it doesn't work in
2834     future.
2836     18. Added an error diagnosis for escapes that PCRE does not support: these are
2837     \L, \l, \N, \P, \p, \U, \u, and \X.
2839     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2840     reading past the end of the pattern in cases such as /[abcd/.
2842     20. PCRE was getting more memory than necessary for patterns with classes that
2843     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2845     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2846     compiling PCRE for use with Virtual Pascal.
2848     22. Small fix to the Makefile to make it work properly if the build is done
2849     outside the source tree.
2851     23. Added a new extension: a condition to go with recursion. If a conditional
2852     subpattern starts with (?(R) the "true" branch is used if recursion has
2853     happened, whereas the "false" branch is used only at the top level.
2855     24. When there was a very long string of literal characters (over 255 bytes
2856     without UTF support, over 250 bytes with UTF support), the computation of how
2857     much memory was required could be incorrect, leading to segfaults or other
2858     strange effects.
2860     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2861     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2862     there was a subsequent back reference to those brackets. This meant that, for
2863     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2864     possible to check for precisely this case. All we can do is abandon the
2865     optimization if .* occurs inside capturing brackets when there are any back
2866     references whatsoever. (See below for a better fix that came later.)
2868     26. The handling of the optimization for finding the first character of a
2869     non-anchored pattern, and for finding a character that is required later in the
2870     match were failing in some cases. This didn't break the matching; it just
2871     failed to optimize when it could. The way this is done has been re-implemented.
2873     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2875     28. Added a new feature that provides some of the functionality that Perl
2876     provides with (?{...}). The facility is termed a "callout". The way it is done
2877     in PCRE is for the caller to provide an optional function, by setting
2878     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2879     global variable. By default it is unset, which disables all calling out. To get
2880     the function called, the regex must include (?C) at appropriate points. This
2881     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2882     This provides a means of identifying different callout points. When PCRE
2883     reaches such a point in the regex, if pcre_callout has been set, the external
2884     function is called. It is provided with data in a structure called
2885     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2886     matching continues; if it returns a non-zero value, the match at the current
2887     point fails. However, backtracking will occur if possible. [This was changed
2888     later and other features added - see item 49 below.]
2890     29. pcretest is upgraded to test the callout functionality. It provides a
2891     callout function that displays information. By default, it shows the start of
2892     the match and the current position in the text. There are some new data escapes
2893     to vary what happens:
2895     \C+ in addition, show current contents of captured substrings
2896     \C- do not supply a callout function
2897     \C!n return 1 when callout number n is reached
2898     \C!n!m return 1 when callout number n is reached for the mth time
2900     30. If pcregrep was called with the -l option and just a single file name, it
2901     output "<stdin>" if a match was found, instead of the file name.
2903     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2904     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2905     pcre_exec(). This saves a malloc/free per call. The default value of
2906     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2907     when configuring.
2909     32. The default maximum size of a compiled pattern is 64K. There have been a
2910     few cases of people hitting this limit. The code now uses macros to handle the
2911     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2912     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2913     configuring. Tests 2 and 5 work only with 2-byte links because they output
2914     debugging information about compiled patterns.
2916     33. Internal code re-arrangements:
2918     (a) Moved the debugging function for printing out a compiled regex into
2919     its own source file (printint.c) and used #include to pull it into
2920     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2921     separate copies.
2923     (b) Defined the list of op-code names for debugging as a macro in
2924     internal.h so that it is next to the definition of the opcodes.
2926     (c) Defined a table of op-code lengths for simpler skipping along compiled
2927     code. This is again a macro in internal.h so that it is next to the
2928     definition of the opcodes.
2930     34. Added support for recursive calls to individual subpatterns, along the
2931     lines of Robin Houston's patch (but implemented somewhat differently).
2933     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2934     allow it to read and process whole directories in Win32. This code was
2935     contributed by Lionel Fourquaux; it has not been tested by me.
2937     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2938     used to name a group. Names consist of alphanumerics and underscores, and must
2939     be unique. Back references use the syntax (?P=name) and recursive calls use
2940     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2941     numbers. The function pcre_fullinfo() can be used after compilation to extract
2942     a name/number map. There are three relevant calls:
2944     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2945     PCRE_INFO_NAMECOUNT yields the number of entries
2946     PCRE_INFO_NAMETABLE yields a pointer to the map.
2948     The map is a vector of fixed-size entries. The size of each entry depends on
2949     the length of the longest name used. The first two bytes of each entry are the
2950     group number, most significant byte first. There follows the corresponding
2951     name, zero terminated. The names are in alphabetical order.
2953     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2954     case instead of 255. Making it the same both with and without UTF-8 support
2955     means that the same test output works with both.
2957     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2958     calling malloc() with a zero argument.
2960     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2961     optimization. I've improved things by keeping a bitmap of backreferences with
2962     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2963     fact referenced, the optimization can be applied. It is unlikely that a
2964     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2965     the match to follow \n) will appear inside brackets with a number greater than
2966     31, but if it does, any back reference > 31 suppresses the optimization.
2968     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2969     of disabling numbered capturing parentheses. Any opening parenthesis that is
2970     not followed by ? behaves as if it were followed by ?: but named parentheses
2971     can still be used for capturing (and they will acquire numbers in the usual
2972     way).
2974     41. Redesigned the return codes from the match() function into yes/no/error so
2975     that errors can be passed back from deep inside the nested calls. A malloc
2976     failure while inside a recursive subpattern call now causes the
2977     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2979     42. It is now possible to set a limit on the number of times the match()
2980     function is called in a call to pcre_exec(). This facility makes it possible to
2981     limit the amount of recursion and backtracking, though not in a directly
2982     obvious way, because the match() function is used in a number of different
2983     circumstances. The count starts from zero for each position in the subject
2984     string (for non-anchored patterns). The default limit is, for compatibility, a
2985     large number, namely 10 000 000. You can change this in two ways:
2987     (a) When configuring PCRE before making, you can use --with-match-limit=n
2988     to set a default value for the compiled library.
2990     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2991     a different value is set. See 45 below.
2993     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2995     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2996     of things that can be changed at compile time. The first argument specifies
2997     what is wanted and the second points to where the information is to be placed.
2998     The current list of available information is:
3002     The output is an integer that is set to one if UTF-8 support is available;
3003     otherwise it is set to zero.
3007     The output is an integer that it set to the value of the code that is used for
3008     newline. It is either LF (10) or CR (13).
3012     The output is an integer that contains the number of bytes used for internal
3013     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3017     The output is an integer that contains the threshold above which the POSIX
3018     interface uses malloc() for output vectors. See item 31 above.
3022     The output is an unsigned integer that contains the default limit of the number
3023     of match() calls in a pcre_exec() execution. See 42 above.
3025     44. pcretest has been upgraded by the addition of the -C option. This causes it
3026     to extract all the available output from the new pcre_config() function, and to
3027     output it. The program then exits immediately.
3029     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3030     order to support additional features. One way would have been to define
3031     pcre_exec2() (for example) with extra arguments, but this would not have been
3032     extensible, and would also have required all calls to the original function to
3033     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3034     is used for passing in "extra" data from pcre_study().
3036     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3037     contains the following fields:
3039     flags a bitmap indicating which of the following fields are set
3040     study_data opaque data from pcre_study()
3041     match_limit a way of specifying a limit on match() calls for a specific
3042     call to pcre_exec()
3043     callout_data data for callouts (see 49 below)
3045     The flag bits are also defined in pcre.h, and are
3051     The pcre_study() function now returns one of these new pcre_extra blocks, with
3052     the actual study data pointed to by the study_data field, and the
3053     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3054     before. That is, this change is entirely upwards-compatible and requires no
3055     change to existing code.
3057     If you want to pass in additional data to pcre_exec(), you can either place it
3058     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3059     block.
3061     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3062     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3063     times with different match limits, until it finds the minimum value needed for
3064     pcre_exec() to complete. The value is then output. This can be instructive; for
3065     most simple matches the number is quite small, but for pathological cases it
3066     gets very large very quickly.
3068     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3069     returns the size of the data block pointed to by the study_data field in a
3070     pcre_extra block, that is, the value that was passed as the argument to
3071     pcre_malloc() when PCRE was getting memory in which to place the information
3072     created by pcre_study(). The fourth argument should point to a size_t variable.
3073     pcretest has been extended so that this information is shown after a successful
3074     pcre_study() call when information about the compiled regex is being displayed.
3076     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3077     because what follows is always an absolute path. (Later: it turns out that this
3078     is more than cosmetic for MinGW, because it doesn't like empty path
3079     components.)
3081     49. Some changes have been made to the callout feature (see 28 above):
3083     (i) A callout function now has three choices for what it returns:
3085     0 => success, carry on matching
3086     > 0 => failure at this point, but backtrack if possible
3087     < 0 => serious error, return this value from pcre_exec()
3089     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3090     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3091     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3092     use by callout functions. It will never be used by PCRE itself.
3094     (ii) The pcre_extra structure (see 45 above) has a void * field called
3095     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3096     pcre_callout_block structure has a field of the same name. The contents of
3097     the field passed in the pcre_extra structure are passed to the callout
3098     function in the corresponding field in the callout block. This makes it
3099     easier to use the same callout-containing regex from multiple threads. For
3100     testing, the pcretest program has a new data escape
3102     \C*n pass the number n (may be negative) as callout_data
3104     If the callout function in pcretest receives a non-zero value as
3105     callout_data, it returns that value.
3107     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3108     there were some redundant $(CFLAGS) in commands that are now specified as
3109     $(LINK), which already includes $(CFLAGS).
3111     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3112     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3113     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3114     one-byte characters throughout. Note that case-insensitive matching applies
3115     only to characters whose values are less than 256. PCRE doesn't support the
3116     notion of cases for higher-valued characters.
3118     (i) A character class whose characters are all within 0-255 is handled as
3119     a bit map, and the map is inverted for negative classes. Previously, a
3120     character > 255 always failed to match such a class; however it should
3121     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3123     (ii) A negated character class with a single character < 255 is coded as
3124     "not this character" (OP_NOT). This wasn't working properly when the test
3125     character was multibyte, either singly or repeated.
3127     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3128     mode, for example: \x{100}{2,3}.
3130     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3131     singly or repeated) now correctly test multibyte characters. However,
3132     PCRE doesn't recognize any characters with values greater than 255 as
3133     digits, spaces, or word characters. Such characters always match \D, \S,
3134     and \W, and never match \d, \s, or \w.
3136     (v) Classes may now contain characters and character ranges with values
3137     greater than 255. For example: [ab\x{100}-\x{400}].
3139     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3140     PCRE in UTF-8 mode.
3142     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3143     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3144     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3145     value.)
3147     53. The single man page has become too large. I have therefore split it up into
3148     a number of separate man pages. These also give rise to individual HTML pages;
3149     these are now put in a separate directory, and there is an index.html page that
3150     lists them all. Some hyperlinking between the pages has been installed.
3152     54. Added convenience functions for handling named capturing parentheses.
3154     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3155     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3156     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3157     are faulted.
3159     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3160     calling configure. These values are used when compiling the dftables.c program
3161     which is run to generate the source of the default character tables. They
3162     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3163     you will need to set these values.
3165     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3168     Version 3.9 02-Jan-02
3169 nigel 61 ---------------------
3171     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3173     2. If --disable-static was given, the building process failed when trying to
3174     build pcretest and pcregrep. (For some reason it was using libtool to compile
3175     them, which is not right, as they aren't part of the library.)
3178 nigel 59 Version 3.8 18-Dec-01
3179     ---------------------
3181     1. The experimental UTF-8 code was completely screwed up. It was packing the
3182     bytes in the wrong order. How dumb can you get?
3185 nigel 57 Version 3.7 29-Oct-01
3186     ---------------------
3188     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3189     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3190     this didn't happen under Solaris 8, where I normally test things.
3192 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3193     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3194     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3195     this fix an hour or so after the initial 3.7 release.)
3196 nigel 57
3197 nigel 59
3198 nigel 55 Version 3.6 23-Oct-01
3199     ---------------------
3201     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3202     offsets passed as NULL with zero offset count.
3204     2. The config.guess and config.sub files had not been updated when I moved to
3205     the latest autoconf.
3208 nigel 53 Version 3.5 15-Aug-01
3209     ---------------------
3210 nigel 5
3211 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3212     had been forgotten.
3214     2. By using declared but undefined structures, we can avoid using "void"
3215     definitions in pcre.h while keeping the internal definitions of the structures
3216     private.
3218     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3219     user point of view, this means that both static and shared libraries are built
3220     by default, but this can be individually controlled. More of the work of
3221     handling this static/shared cases is now inside libtool instead of PCRE's make
3222     file.
3224     4. The pcretest utility is now installed along with pcregrep because it is
3225     useful for users (to test regexs) and by doing this, it automatically gets
3226     relinked by libtool. The documentation has been turned into a man page, so
3227     there are now .1, .txt, and .html versions in /doc.
3229     5. Upgrades to pcregrep:
3230     (i) Added long-form option names like gnu grep.
3231     (ii) Added --help to list all options with an explanatory phrase.
3232     (iii) Added -r, --recursive to recurse into sub-directories.
3233     (iv) Added -f, --file to read patterns from a file.
3235     6. pcre_exec() was referring to its "code" argument before testing that
3236     argument for NULL (and giving an error if it was NULL).
3238     7. Upgraded Makefile.in to allow for compiling in a different directory from
3239     the source directory.
3241     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3242     options bits, the pointer it was passed was to an int instead of to an unsigned
3243     long int. This mattered only on 64-bit systems.
3245     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3246     generated) instead of pcre.in, which it its source. Also made the same change
3247     in several of the .c files.
3249     10. A new release of gcc defines printf() as a macro, which broke pcretest
3250     because it had an ifdef in the middle of a string argument for printf(). Fixed
3251     by using separate calls to printf().
3253     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3254     script, to force use of CR or LF instead of \n in the source. On non-Unix
3255     systems, the value can be set in config.h.
3257     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3258     absolute limit. Changed the text of the error message to make this clear, and
3259     likewise updated the man page.
3261     13. The limit of 99 on the number of capturing subpatterns has been removed.
3262     The new limit is 65535, which I hope will not be a "real" limit.
3265 nigel 51 Version 3.4 22-Aug-00
3266     ---------------------
3268     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3270     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3273 nigel 49 Version 3.3 01-Aug-00
3274     ---------------------
3276     1. If an octal character was given, but the value was greater than \377, it
3277     was not getting masked to the least significant bits, as documented. This could
3278     lead to crashes in some systems.
3280     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3281     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3283     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3284     These just pass their arguments on to (pcre_free)(), but they are provided
3285     because some uses of PCRE bind it to non-C systems that can call its functions,
3286     but cannot call free() or pcre_free() directly.
3288     4. Add "make test" as a synonym for "make check". Corrected some comments in
3289     the Makefile.
3291     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3292     Makefile.
3294     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3295     command called pgrep for grepping around the active processes.
3297     7. Added the beginnings of support for UTF-8 character strings.
3299     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3300     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3301     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3302     out for the ar command.)
3305 nigel 47 Version 3.2 12-May-00
3306     ---------------------
3308     This is purely a bug fixing release.
3310     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3311     of ZA. This was just one example of several cases that could provoke this bug,
3312     which was introduced by change 9 of version 2.00. The code for breaking
3313     infinite loops after an iteration that matches an empty string was't working
3314     correctly.
3316     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3317     when matched against abbab (for example). After matching an empty string, it
3318     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3319     caused it to match further down the string than it should.
3321     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3322     was there because it doesn't seem to be needed, and it causes trouble on some
3323     systems, as it is not a Standard C header. It has been removed.
3325     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3326     were reported on the Macintosh. The changes were from
3328     while ((c = *(++ptr)) != 0 && c != '\n');
3329     to
3330     while ((c = *(++ptr)) != 0 && c != '\n') ;
3332     Totally extraordinary, but if that's what it takes...
3334     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3335     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3336     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3337     assumes the way PCRE uses memmove() (always moving upwards).
3339     6. PCRE is being used in one environment where strchr() is not available. There
3340     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3341     faster code anyway.
3344 nigel 45 Version 3.1 09-Feb-00
3345     ---------------------
3347     The only change in this release is the fixing of some bugs in Makefile.in for
3348     the "install" target:
3350     (1) It was failing to install pcreposix.h.
3352     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3355 nigel 43 Version 3.0 01-Feb-00
3356     ---------------------
3357 nigel 41
3358     1. Add support for the /+ modifier to perltest (to output $` like it does in
3359     pcretest).
3361     2. Add support for the /g modifier to perltest.
3363     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3364     matches null strings.
3366     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3367     pattern. Perl treats empty patterns specially - it reuses the most recent
3368     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3369     effect.
3371     5. The POSIX interface was broken in that it was just handing over the POSIX
3372     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3373     required a bigger vector, with some working space on the end. This means that
3374     the POSIX wrapper now has to get and free some memory, and copy the results.
3376 nigel 43 6. Added some simple autoconf support, placing the test data and the
3377     documentation in separate directories, re-organizing some of the
3378     information files, and making it build pcre-config (a GNU standard). Also added
3379     libtool support for building PCRE as a shared library, which is now the
3380     default.
3381 nigel 41
3382 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3383     09 are not valid octal constants. Single digits will be used for minor values
3384     less than 10.
3386     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3387     existing programs that set these in the POSIX interface can use PCRE without
3388     modification.
3390     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3391     return all that pcre_info() returns, plus additional data. The pcre_info()
3392     function is retained for compatibility, but is considered to be obsolete.
3394     10. Added experimental recursion feature (?R) to handle one common case that
3395     Perl 5.6 will be able to do with (?p{...}).
3397     11. Added support for POSIX character classes like [:alpha:], which Perl is
3398     adopting.
3401 nigel 39 Version 2.08 31-Aug-99
3402     ----------------------
3404     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3405     trying to match at the startoffset position, but instead was moving forward to
3406     the next newline as if a previous match had failed.
3408     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3409     and could get into a loop if a null string was matched other than at the start
3410     of the subject.
3412     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3413     be distinguished at compile time, and for completeness also added PCRE_DATE.
3415     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3416     in GnuWin32 environments.
3419 nigel 37 Version 2.07 29-Jul-99
3420     ----------------------
3422     1. The documentation is now supplied in plain text form and HTML as well as in
3423     the form of man page sources.
3425     2. C++ compilers don't like assigning (void *) values to other pointer types.
3426     In particular this affects malloc(). Although there is no problem in Standard
3427     C, I've put in casts to keep C++ compilers happy.
3429     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3430     should be (const char *).
3432     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3433     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3434     However, I haven't made this a standard facility. The documentation doesn't
3435     mention it, and the Makefile doesn't support it.
3437     5. The Makefile now contains an "install" target, with editable destinations at
3438     the top of the file. The pcretest program is not installed.
3440     6. pgrep -V now gives the PCRE version number and date.
3442     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3443     causing the entire string to be ignored, instead of just the last character.
3445     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3446     non-matching string, it can take a very, very long time, even for strings of
3447     quite modest length, because of the nested recursion. PCRE now does better in
3448     some of these cases. It does this by remembering the last required literal
3449     character in the pattern, and pre-searching the subject to ensure it is present
3450     before running the real match. In other words, it applies a heuristic to detect
3451     some types of certain failure quickly, and in the above example, if presented
3452     with a string that has no trailing " it gives "no match" very quickly.
3454     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3455     other alternatives are tried instead.
3458 nigel 35 Version 2.06 09-Jun-99
3459     ----------------------
3461     1. Change pcretest's output for amount of store used to show just the code
3462     space, because the remainder (the data block) varies in size between 32-bit and
3463     64-bit systems.
3465     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3466     start matching at. This allows lookbehinds to work when searching for multiple
3467     occurrences in a string.
3469     3. Added additional options to pcretest for testing multiple occurrences:
3471     /+ outputs the rest of the string that follows a match
3472     /g loops for multiple occurrences, using the new startoffset argument
3473     /G loops for multiple occurrences by passing an incremented pointer
3475     4. PCRE wasn't doing the "first character" optimization for patterns starting
3476     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3477     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3478     the letter 'x'. On long subject strings, this gives a significant speed-up.
3481 nigel 33 Version 2.05 21-Apr-99
3482     ----------------------
3484     1. Changed the type of magic_number from int to long int so that it works
3485     properly on 16-bit systems.
3487     2. Fixed a bug which caused patterns starting with .* not to work correctly
3488     when the subject string contained newline characters. PCRE was assuming
3489     anchoring for such patterns in all cases, which is not correct because .* will
3490     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3491     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3492     must be retried after every newline in the subject.
3495 nigel 31 Version 2.04 18-Feb-99
3496     ----------------------
3498     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3499     computation of the store needed to hold the pattern was incorrect (too large).
3500     If such patterns were nested a few deep, this could multiply and become a real
3501     problem.
3503     2. Added /M option to pcretest to show the memory requirement of a specific
3504     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3506     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3507     compiled in such a way that the backtracking after subsequent failure was
3508     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3509     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3512 nigel 29 Version 2.03 02-Feb-99
3513     ----------------------
3515     1. Fixed typo and small mistake in man page.
3517 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3518     LICENCE file containing the conditions.
3519 nigel 29
3520     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3521     Perl, that is the internal \ allows the delimiter to be included in the
3522     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3523     the final delimiter, add \ to the end of the pattern (to test the error).
3525     4. Added the convenience functions for extracting substrings after a successful
3526     match. Updated pcretest to make it able to test these functions.
3529 nigel 27 Version 2.02 14-Jan-99
3530     ----------------------
3532     1. Initialized the working variables associated with each extraction so that
3533     their saving and restoring doesn't refer to uninitialized store.
3535     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3536     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3537     fix the problem.
3539     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3540     calls, and wasn't printing the correct value for compiling calls. Increased the
3541     default value of LOOPREPEAT, and the number of significant figures in the
3542     times.
3544     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3546     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3547     a building problem on Windows NT with a FAT file system.
3550 nigel 25 Version 2.01 21-Oct-98
3551     ----------------------
3553     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3554     to character tables built by pcre_maketables() in the current locale. If NULL
3555     is passed, the default tables are used.
3558 nigel 23 Version 2.00 24-Sep-98
3559 nigel 21 ----------------------
3561 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3562     it any more.
3564     2. Allow quantification of (?>) groups, and make it work correctly.
3566     3. The first character computation wasn't working for (?>) groups.
3568     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3569     end of the subject) and add 5.005's \z, which really does match only at the
3570     very end of the subject.
3572     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3574     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3575     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3576     localized options. All options to pcre_study() were also removed.
3578     7. Add other new features from 5.005:
3580     $(?<= positive lookbehind
3581     $(?<! negative lookbehind
3582     (?imsx-imsx) added the unsetting capability
3583     such a setting is global if at outer level; local otherwise
3584     (?imsx-imsx:) non-capturing groups with option setting
3585     (?(cond)re|re) conditional pattern matching
3587     A backreference to itself in a repeated group matches the previous
3588     captured string.
3590     8. General tidying up of studying (both automatic and via "study")
3591     consequential on the addition of new assertions.
3593     9. As in 5.005, unlimited repeated groups that could match an empty substring
3594     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3595     runtime if any iteration does actually match an empty substring.
3597     10. Include the RunTest script in the distribution.
3599     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3600     discrepancies, some of which were old and were also with respect to 5.004. They
3601     have now been fixed.
3604     Version 1.09 28-Apr-98
3605     ----------------------
3607 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3608     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3609     program crashes, or just wrong answers. This did not apply to negated classes
3610     containing more than one character, or to minima other than one.
3613 nigel 19 Version 1.08 27-Mar-98
3614     ----------------------
3616     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3618     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3619     latter must appear before anything that relies on it in the pattern.
3622 nigel 17 Version 1.07 16-Feb-98
3623     ----------------------
3625     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3626     repeat of a potentially empty string).
3629 nigel 15 Version 1.06 23-Jan-98
3630     ----------------------
3632     1. Added Markus Oberhumer's little patches for C++.
3634     2. Literal strings longer than 255 characters were broken.
3637 nigel 13 Version 1.05 23-Dec-97
3638     ----------------------
3640     1. Negated character classes containing more than one character were failing if
3641     PCRE_CASELESS was set at run time.
3644 nigel 11 Version 1.04 19-Dec-97
3645     ----------------------
3647     1. Corrected the man page, where some "const" qualifiers had been omitted.
3649     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3650     input syntax.
3652     3. Fixed memory leak which occurred when a regex with back references was
3653     matched with an offsets vector that wasn't big enough. The temporary memory
3654     that is used in this case wasn't being freed if the match failed.
3656     4. Tidied pcretest to ensure it frees memory that it gets.
3658     5. Temporary memory was being obtained in the case where the passed offsets
3659     vector was exactly big enough.
3661     6. Corrected definition of offsetof() from change 5 below.
3663     7. I had screwed up change 6 below and broken the rules for the use of
3664     setjmp(). Now fixed.
3667 nigel 9 Version 1.03 18-Dec-97
3668     ----------------------
3670     1. A erroneous regex with a missing opening parenthesis was correctly
3671     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3672     on some systems.
3674     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3675     it was reported that one broken compiler failed on the former because "code" is
3676     also an independent variable.
3678     3. The erroneous regex a[]b caused an array overrun reference.
3680     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3681     fail on data ending with that character. (It was going on too far, and checking
3682     the next character, typically a binary zero.) This was specific to the
3683     optimized code for single-character negative classes.
3685     5. Added a contributed patch from the TIN world which does the following:
3687     + Add an undef for memmove, in case the the system defines a macro for it.
3689     + Add a definition of offsetof(), in case there isn't one. (I don't know
3690     the reason behind this - offsetof() is part of the ANSI standard - but
3691     it does no harm).
3693     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3694     most of the places where whitespace preceded '#'. I have given up and
3695     allowed the remaining 2 cases to be at the margin.
3697     + Rename some variables in pcre to eliminate shadowing. This seems very
3698     pedantic, but does no harm, of course.
3700     6. Moved the call to setjmp() into its own function, to get rid of warnings
3701     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3703     7. Constructs such as \d{8,} were compiling into the equivalent of
3704 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3705 nigel 9 outcome, but in this particular case used more store than had been allocated,
3706     which caused the bug to be discovered because it threw up an internal error.
3708     8. The debugging code in both pcre and pcretest for outputting the compiled
3709     form of a regex was going wrong in the case of back references followed by
3710     curly-bracketed repeats.
3713 nigel 7 Version 1.02 12-Dec-97
3714     ----------------------
3716     1. Typos in pcre.3 and comments in the source fixed.
3718     2. Applied a contributed patch to get rid of places where it used to remove
3719     'const' from variables, and fixed some signed/unsigned and uninitialized
3720     variable warnings.
3722     3. Added the "runtest" target to Makefile.
3724     4. Set default compiler flag to -O2 rather than just -O.
3727 nigel 5 Version 1.01 19-Nov-97
3728     ----------------------
3730     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3731     like /([ab]*)*/, that is, for classes with more than one character in them.
3733     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3734     as /((?>a*))*/ (a PCRE_EXTRA facility).
3737     Version 1.00 18-Nov-97
3738     ----------------------
3740     1. Added compile-time macros to support systems such as SunOS4 which don't have
3741     memmove() or strerror() but have other things that can be used instead.
3743     2. Arranged that "make clean" removes the executables.
3746 nigel 3 Version 0.99 27-Oct-97
3747     ----------------------
3749     1. Fixed bug in code for optimizing classes with only one character. It was
3750     initializing a 32-byte map regardless, which could cause it to run off the end
3751     of the memory it had got.