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Revision 566 - (hide annotations) (download)
Wed Nov 3 18:32:55 2010 UTC (4 years, 4 months ago) by ph10
File size: 194016 byte(s)
Fix broken /g code in pcretest and -g code in pcredemo.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 550 Version 8.11 10-Oct-2010
5     ------------------------
7     1. (*THEN) was not working properly if there were untried alternatives prior
8     to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9     backtracked to try for "b" instead of moving to the next alternative branch
10     at the same level (in this case, to look for "c"). The Perl documentation
11     is clear that when (*THEN) is backtracked onto, it goes to the "next
12     alternative in the innermost enclosing group".
13 ph10 551
14     2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15     such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
16     result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17     (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18     (*THEN).
19 ph10 552
20     3. If \s appeared in a character class, it removed the VT character from
21     the class, even if it had been included by some previous item, for example
22     in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
23     of \s, but is part of the POSIX "space" class.)
24 ph10 553
25     4. A partial match never returns an empty string (because you can always
26     match an empty string at the end of the subject); however the checking for
27     an empty string was starting at the "start of match" point. This has been
28     changed to the "earliest inspected character" point, because the returned
29     data for a partial match starts at this character. This means that, for
30     example, /(?<=abc)def/ gives a partial match for the subject "abc"
31     (previously it gave "no match").
32 ph10 550
33 ph10 553 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
34     of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
35     previously a full match would be given. However, setting PCRE_PARTIAL_HARD
36     has an implication that the given string is incomplete (because a partial
37     match is preferred over a full match). For this reason, these items now
38     give a partial match in this situation. [Aside: previously, the one case
39     /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
40     match rather than a full match, which was wrong by the old rules, but is
41     now correct.]
42 ph10 556
43     6. There was a bug in the handling of #-introduced comments, recognized when
44     PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
45     If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
46     UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
47     scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
48     but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
49     places in pcre_compile().
51     7. Related to (6) above, when pcre_compile() was skipping #-introduced
52     comments when looking ahead for named forward references to subpatterns,
53     the only newline sequence it recognized was NL. It now handles newlines
54     according to the set newline convention.
55 ph10 558
56     8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
57     former, but used strtoul(), whereas pcretest avoided strtoul() but did not
58     cater for a lack of strerror(). These oversights have been fixed.
59 ph10 561
60     9. Added --match-limit and --recursion-limit to pcregrep.
61 ph10 550
62 ph10 563 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
63 ph10 553
64 ph10 564 11. When the -o option was used, pcregrep was setting a return code of 1, even
65     when matches were found, and --line-buffered was not being honoured.
66 ph10 565
67     12. Added an optional parentheses number to the -o and --only-matching options
68     of pcregrep.
69 ph10 566
70     13. Imitating Perl's /g action for multiple matches is tricky when the pattern
71     can match an empty string. The code to do it in pcretest and pcredemo
72     needed fixing:
74     (a) When the newline convention was "crlf", pcretest got it wrong, skipping
75     only one byte after an empty string match just before CRLF (this case
76     just got forgotten; "any" and "anycrlf" were OK).
78     (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
79     mode when an empty string match preceded an ASCII character followed by
80     a non-ASCII character. (The code for advancing by one character rather
81     than one byte was nonsense.)
83     (c) The pcredemo.c sample program did not have any code at all to handle
84     the cases when CRLF is a valid newline sequence.
85 ph10 563
86 ph10 564
87 ph10 548 Version 8.10 25-Jun-2010
88 ph10 510 ------------------------
90 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
91 ph10 510 THEN.
93 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
94 ph10 510
95 ph10 535 3. Inside a character class, \B is treated as a literal by default, but
96     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
97 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
98 ph10 535
99     4. Inside a character class, PCRE always treated \R and \X as literals,
100 ph10 513 whereas Perl faults them if its -w option is set. I have changed PCRE so
101     that it faults them when PCRE_EXTRA is set.
102 ph10 535
103 ph10 514 5. Added support for \N, which always matches any character other than
104     newline. (It is the same as "." when PCRE_DOTALL is not set.)
105 ph10 535
106 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
107 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
108 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
109 ph10 535 result to (void) does not stop the warnings; a more elaborate fudge is
110     needed. I've used a macro to implement this.
111 ph10 512
112 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
114 ph10 517 8. Added four artifical Unicode properties to help with an option to make
115 ph10 518 \s etc use properties (see next item). The new properties are: Xan
116     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
117 ph10 535
118 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
119 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
120 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
121     REG_UCP to make it available via the POSIX interface.
122 ph10 513
123 ph10 535 10. Added --line-buffered to pcregrep.
125     11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
126     studied, and the match started with a letter with a code point greater than
127 ph10 520 127 whose first byte was different to the first byte of the other case of
128 ph10 545 the letter, the other case of this starting letter was not recognized
129 ph10 536 (#976).
130 ph10 535
131 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
132 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
133 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
134     not have actually happened in practice until change 8 above was made (it
135 ph10 523 added property types that matched character-matching opcodes).
136 ph10 535
137 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
138 ph10 535 possible starting bytes for non-anchored patterns.
140 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
141 ph10 535 \R, and also a number of cases that involve Unicode properties, both
142 ph10 532 explicit and implicit when PCRE_UCP is set.
143 ph10 529
144 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
145 ph10 535 input, it could crash or give wrong results if characters with values
146     greater than 0xc0 were present in the subject string. (Detail: it assumed
147 ph10 529 UTF-8 input when processing these items.)
148 ph10 535
149 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
150     size_t is 64-bit (#991).
151 ph10 535
152 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
153     --disable-stack-for-recursion (#990).
154 ph10 545
155 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
156 ph10 545 the end, a newline was missing in the output.
158     19. The default pcre_chartables.c file recognizes only ASCII characters (values
159     less than 128) in its various bitmaps. However, there is a facility for
160     generating tables according to the current locale when PCRE is compiled. It
161     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
162     characters, are recognized by isspace() and therefore were getting set in
163 ph10 541 these tables, and indeed these tables seem to approximate to ISO 8859. This
164     caused a problem in UTF-8 mode when pcre_study() was used to create a list
165     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
166     which of course cannot start UTF-8 characters. I have changed the code so
167     that only real ASCII characters (less than 128) and the correct starting
168 ph10 545 bytes for UTF-8 encodings are set for characters greater than 127 when in
169 ph10 541 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
170     altogether.)
171 ph10 545
172 ph10 541 20. Added the /T option to pcretest so as to be able to run tests with non-
173     standard character tables, thus making it possible to include the tests
174 ph10 545 used for 19 above in the standard set of tests.
176     21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
177     reference to a subpattern the other side of a comment that contains an
178     opening parenthesis caused either an internal compiling error, or a
179 ph10 544 reference to the wrong subpattern.
180 ph10 517
181 ph10 520
182 ph10 508 Version 8.02 19-Mar-2010
183 ph10 491 ------------------------
185     1. The Unicode data tables have been updated to Unicode 5.2.0.
187 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
188     configured.
189 ph10 507
190 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
191 ph10 507 original author of that file, following a query about its status.
193     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
194 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
195 ph10 507
196 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
197     quantifier applied to a forward-referencing subroutine call, could compile
198     incorrect code or give the error "internal error: previously-checked
199     referenced subpattern not found".
200 ph10 507
201     6. Both MS Visual Studio and Symbian OS have problems with initializing
202 ph10 497 variables to point to external functions. For these systems, therefore,
203     pcre_malloc etc. are now initialized to local functions that call the
204     relevant global functions.
205 ph10 507
206 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
207     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
208 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
209     the lengths are correct (equal to the number of opcodes).
211     8. Following on from 7, I added a similar kludge to check the length of the
212     eint vector in pcreposix.c.
214     9. Error texts for pcre_compile() are held as one long string to avoid too
215     much relocation at load time. To find a text, the string is searched,
216 ph10 499 counting zeros. There was no check for running off the end of the string,
217     which could happen if a new error number was added without updating the
218 ph10 507 string.
220     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
222 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
223 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
224     \K is "not well defined" if used in an assertion. PCRE now accepts it if
225     the assertion is positive, but not if it is negative.
227 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
228 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
229     implementation of support for (*MARK) will need an extra pointer on the
230 ph10 501 stack; I have reserved it now, so that the stack frame size does not
231     decrease.
232 ph10 507
233     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
234     item in branch that calls a recursion is a subroutine call - as in the
235 ph10 503 second branch in the above example - was incorrectly given the compile-
236     time error "recursive call could loop indefinitely" because pcre_compile()
237 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
239 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
240 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
241 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
242 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
243 ph10 491
244 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
245 ph10 492
246 ph10 507
247 ph10 489 Version 8.01 19-Jan-2010
248     ------------------------
249 ph10 471
250     1. If a pattern contained a conditional subpattern with only one branch (in
251 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
252 ph10 473 computed the wrong minimum data length (which is of course zero for such
253 ph10 489 subpatterns). This could cause incorrect "no match" results.
254 ph10 473
255     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
256 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
257     "internal error: code overflow at offset...". This happened only when
258 ph10 473 the reset was to the original external option setting. (An optimization
259     abstracts leading options settings into an external setting, which was the
260 ph10 472 cause of this.)
261 ph10 471
262 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
263     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
264     assertion pattern did not match (meaning that the assertion was true), it
265     was incorrectly treated as false if the SKIP had been reached during the
266     matching. This also applied to assertions used as conditions.
267 ph10 471
268 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
269     assertion subpattern, including such a pattern used as a condition,
270     unpredictable results occurred, instead of the error return
272 ph10 478
273 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
274     situation when an empty string is matched. It now does the fancy magic
275 ph10 478 stuff that is necessary.
277     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
278 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
279 ph10 478
280 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
281     as part of something else:
282 ph10 478
283     (a) Change DEBUG to PCRE_DEBUG.
285     (b) In pcre_compile(), rename the member of the "branch_chain" structure
286     called "current" as "current_branch", to prevent a collision with the
287 ph10 475 Linux macro when compiled as a kernel module.
288 ph10 478
289     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
290     prevent a collision with the Linux macro when compiled as a kernel
291 ph10 475 module.
292 ph10 478
293 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
294     cast potentially large values to (double). This has been changed to that
295 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
296     instead, thus avoiding the use of floating point arithmetic. (There is no
297     other use of FP in PCRE.) If int64_t is not found, the fallback is to
298     double.
300     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
301 ph10 476 2005 (difference between two addresses compared to an unsigned value).
302 ph10 473
303 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
304     custom one, because of the following reported problem in Windows:
305 ph10 473
306 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
307 ph10 489 under Win32.
308 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
309 ph10 489 therefore missing the function definition.
310 ph10 478 - The compiler thus generates a "C" signature for the test function.
311     - The linker fails to find the "C" function.
312     - PCRE fails to configure if asked to do so against libbz2.
313 ph10 486
314 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
315     messages were output:
316 ph10 478
317 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
318     rerunning libtoolize, to keep the correct libtool macros in-tree.
319     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
320 ph10 486
321 ph10 479 I have done both of these things.
322 ph10 486
323 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
324 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
325     runaway infinite recursion. I updated the discussion in the pcrestack man
326     page.
328     13. Now that we have gone to the x.xx style of version numbers, the minor
329     version may start with zero. Using 08 or 09 is a bad idea because users
330     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
331     interpreted as invalid octal numbers. I've updated the previous comment in
332     configure.ac, and also added a check that gives an error if 08 or 09 are
333 ph10 481 used.
334 ph10 486
335 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
336 ph10 483 causing partial matching to fail when the end of the subject matched \W
337     in a UTF-8 pattern where \W was quantified with a minimum of 3.
338 ph10 486
339 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
340 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
341 ph10 483 their definitions. The declarations used "const uschar *" and the
342     definitions used USPTR. Even though USPTR is normally defined as "const
343     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
344     reported that: "This difference in casting confuses some C++ compilers, for
345     example, SunCC recognizes above declarations as different functions and
346 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
347 ph10 483 USPTR.
348 ph10 486
349     16. GNU libtool is named differently on some systems. The autogen.sh script now
350 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
351     (FreeBSD).
352 ph10 478
353 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
354     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
355     comment: "Figure out how to create a longlong from a string: strtoll and
356     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
357     instance, but it only takes 2 args instead of 3!"
358 ph10 479
359 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
360     specification, with a corresponding code fix. A pattern such as
361     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
362     refers, was giving matches when it shouldn't. For example, xa=xaaa would
363     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
364     same bug. Such groups have to be quantified to be useful, or contained
365     inside another quantified group. (If there's no repetition, the reference
366     can never match.) The problem arises because, having left the group and
367     moved on to the rest of the pattern, a later failure that backtracks into
368     the group uses the captured value from the final iteration of the group
369     rather than the correct earlier one. I have fixed this in PCRE by forcing
370     any group that contains a reference to itself to be an atomic group; that
371     is, there cannot be any backtracking into it once it has completed. This is
372     similar to recursive and subroutine calls.
373 ph10 486
374 ph10 488
375 ph10 469 Version 8.00 19-Oct-09
376 ph10 418 ----------------------
378     1. The table for translating pcre_compile() error codes into POSIX error codes
379 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
380     being within the table. This could lead to an OK return being given in
381 ph10 418 error.
382 ph10 461
383     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
384     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
385     in a Windows environment.
387 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
388     zero, as does GNU grep. However, pcregrep was also printing all files when
389     --files-with-matches was added. Now, when both options are given, it prints
390     counts only for those files that have at least one match. (GNU grep just
391 ph10 461 prints the file name in this circumstance, but including the count seems
392     more useful - otherwise, why use --count?) Also ensured that the
393 ph10 420 combination -clh just lists non-zero counts, with no names.
394 ph10 461
395     4. The long form of the pcregrep -F option was incorrectly implemented as
396     --fixed_strings instead of --fixed-strings. This is an incompatible change,
397     but it seems right to fix it, and I didn't think it was worth preserving
398     the old behaviour.
400     5. The command line items --regex=pattern and --regexp=pattern were not
401 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
402 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
403 ph10 422 which are compatible with GNU grep; these now work.
404 ph10 461
405     6. No libpcreposix.pc file was created for pkg-config; there was just
406 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
407 ph10 461
408 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
409 ph10 461 when UCP support is not needed, by modifying the Python script that
410 ph10 425 generates it from Unicode data files. This should not matter if the module
411     is correctly used as a library, but I received one complaint about 50K of
412     unwanted data. My guess is that the person linked everything into his
413     program rather than using a library. Anyway, it does no harm.
414 ph10 461
415 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
416 ph10 461 was a minimum greater than 1 for a wide character in a possessive
417 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
418     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
419     character. Chaos in the form of incorrect output or a compiling loop could
420     result.
421 ph10 461
422 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
423 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
424 ph10 426 partially matched by this function. In addition, if there are at least two
425 ph10 435 slots in the offset vector, the offset of the earliest inspected character
426     for the match and the offset of the end of the subject are set in them when
427 ph10 461 PCRE_ERROR_PARTIAL is returned.
429 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
430     synonymous with PCRE_PARTIAL, for backwards compatibility, and
431     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
432 ph10 462 and may be more useful for multi-segment matching.
433 ph10 461
434     11. Partial matching with pcre_exec() is now more intuitive. A partial match
435     used to be given if ever the end of the subject was reached; now it is
436     given only if matching could not proceed because another character was
437     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
438     string "Z", which now yields "no match" instead of "partial match". In the
439     case of pcre_dfa_exec(), "no match" is given if every matching path for the
440     final character ended with (*FAIL).
442 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
443 ph10 461 if the pattern had a "must contain" character that was already found in the
444 ph10 428 earlier partial match, unless partial matching was again requested. For
445     example, with the pattern /dog.(body)?/, the "must contain" character is
446     "g". If the first part-match was for the string "dog", restarting with
447 ph10 435 "sbody" failed. This bug has been fixed.
448 ph10 461
449     13. The string returned by pcre_dfa_exec() after a partial match has been
450     changed so that it starts at the first inspected character rather than the
451     first character of the match. This makes a difference only if the pattern
452     starts with a lookbehind assertion or \b or \B (\K is not supported by
453     pcre_dfa_exec()). It's an incompatible change, but it makes the two
454 ph10 435 matching functions compatible, and I think it's the right thing to do.
455 ph10 461
456 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
457 ph10 461 so that the demonstration program is easily available in environments where
458     PCRE has not been installed from source.
460 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
461 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
462     library.
463 ph10 461
464 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
465 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
466 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
467 ph10 433 these options useful.
468 ph10 461
469     17. If a caller to the POSIX matching function regexec() passes a non-zero
470 ph10 438 value for nmatch with a NULL value for pmatch, the value of
471 ph10 461 nmatch is forced to zero.
473 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
474 ph10 461 the diff command, as RunTest does. It now checks in the same way as
475 ph10 437 RunTest, and also checks for the -b option.
476 ph10 461
477 ph10 438 19. If an odd number of negated classes containing just a single character
478     interposed, within parentheses, between a forward reference to a named
479 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
480     an internal error, complaining that it could not find the referenced
481 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
482 ph10 461 [The bug was that it was starting one character too far in when skipping
483     over the character class, thus treating the ] as data rather than
484     terminating the class. This meant it could skip too much.]
486 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
487 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
488 ph10 442 to have an empty string match not at the start, even when the pattern is
489 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
491 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
492 ph10 461 than the maximum at the outer level, the higher number was returned, but
493     with unset values at the outer level. The correct (outer level) value is
494 ph10 446 now given.
495 ph10 461
496 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
497     PCRE did not set those parentheses (unlike Perl). I have now found a way to
498     make it do so. The string so far is captured, making this feature
499     compatible with Perl.
500 ph10 461
501     23. The tests have been re-organized, adding tests 11 and 12, to make it
502 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
503 ph10 461
504 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
505 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
506     does. Neither allows recursion.
508     25. I finally figured out how to implement a request to provide the minimum
509     length of subject string that was needed in order to match a given pattern.
510     (It was back references and recursion that I had previously got hung up
511     on.) This code has now been added to pcre_study(); it finds a lower bound
512 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
513     bound, but using it to avoid searching strings that are too short does give
514     some useful speed-ups. The value is available to calling programs via
515     pcre_fullinfo().
516 ph10 461
517 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
518     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
519     study optimizations had never been tested with that matching function.
520     Oops. What is worse, even when it was passed study data, there was a bug in
521     pcre_dfa_exec() that meant it never actually used it. Double oops. There
522     were also very few tests of studied patterns with pcre_dfa_exec().
523 ph10 461
524 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
525     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
526     on the other side of the coin, they are no longer allowed to have different
527     names, because these cannot be distinguished in PCRE, and this has caused
528     confusion. (This is a difference from Perl.)
529 ph10 461
530     28. When duplicate subpattern names are present (necessarily with different
531     numbers, as required by 27 above), and a test is made by name in a
532     conditional pattern, either for a subpattern having been matched, or for
533     recursion in such a pattern, all the associated numbered subpatterns are
534 ph10 459 tested, and the overall condition is true if the condition is true for any
535     one of them. This is the way Perl works, and is also more like the way
536     testing by number works.
537 ph10 418
538 ph10 461
539 ph10 412 Version 7.9 11-Apr-09
540 ph10 376 ---------------------
542 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
543 ph10 376 (pcretest), all targets were linked against these libraries. This included
544     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
545     libraries. This caused unwanted dependencies to be created. This problem
546 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
547 ph10 376 pcretest is linked with readline.
548 ph10 392
549 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
550     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
551     moved outside it again, because FALSE and TRUE are already defined in AIX,
552     but BOOL is not.
553 ph10 392
554     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
555 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
556 ph10 392
557 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
558     hyphens) following file names and line numbers when outputting matching
559 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
560 ph10 376 wording for the --colour (or --color) option.
561 ph10 392
562 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
563     was not coloured; this is different to GNU grep, so I have changed it to be
564     the same.
565 ph10 392
566 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
567 ph10 392 each matching line was coloured. Now it goes on to look for further matches
568     of any of the test patterns, which is the same behaviour as GNU grep.
570     7. A pattern that could match an empty string could cause pcregrep to loop; it
571     doesn't make sense to accept an empty string match in pcregrep, so I have
572 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
573     seems to be how GNU grep behaves.
574 ph10 392
575 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
576 ph10 392 start or after a newline", because the conditional assertion was not being
577     correctly handled. The rule now is that both the assertion and what follows
578     in the first alternative must satisfy the test.
580 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
581 ph10 399 condition was an assertion, PCRE could crash during matching, both with
582     pcre_exec() and pcre_dfa_exec().
583 ph10 392
584     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
585     used for matching.
587     11. Unicode property support in character classes was not working for
588 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
589 ph10 388
590 ph10 392 12. Added the -M command line option to pcretest.
592 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
593 ph10 389
594     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
595 ph10 390
596 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
597 ph10 390 wrapper.
598 ph10 392
599 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
600 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
601 ph10 391 string constants.
602 ph10 405
603 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
604     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
605 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
606     these, but not everybody uses configure.
608     19. A conditional group that had only one branch was not being correctly
609     recognized as an item that could match an empty string. This meant that an
610     enclosing group might also not be so recognized, causing infinite looping
611     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
612     with the subject "ab", where knowledge that the repeated group can match
613 ph10 396 nothing is needed in order to break the loop.
614 ph10 405
615 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
616 ph10 405 exec(), but without supplying a callout function, matching went wrong.
618     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
619     leak if the size of the offset vector was greater than 30. When the vector
620     is smaller, the saved offsets during recursion go onto a local stack
621     vector, but for larger vectors malloc() is used. It was failing to free
622     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
623 ph10 400 error, in fact).
624 ph10 405
625 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
626 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
627     problem, but was untidy.
628 ph10 376
629 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
630     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
631     included within another project.
632 ph10 411
633 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
634     slightly modified by me:
635 ph10 411
636     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
637     not building pcregrep.
639 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
640 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
642 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
643     duplicate group numbers, could behave incorrectly or give incorrect errors,
644     because when scanning forward to find the reference group, PCRE was not
645     taking into account the duplicate group numbers. A pattern such as
646     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
647 ph10 411
648     26. Changed a few more instances of "const unsigned char *" to USPTR, making
649     the feature of a custom pointer more persuasive (as requested by a user).
650 ph10 416
651 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
652 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
653     pre-defined.
654 ph10 392
655 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
657 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
658     in the configuration summary.
659 ph10 405
660 ph10 411
661 ph10 374 Version 7.8 05-Sep-08
662 ph10 349 ---------------------
664     1. Replaced UCP searching code with optimized version as implemented for Ad
665     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
666 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
667     to 5 times on some simple patterns that I tested. Permission was given to
668     distribute the MultiStage2.py script that generates the tables (it's not in
669     the tarball, but is in the Subversion repository).
670 ph10 349
671 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
672     scripts.
673 ph10 358
674 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
675     a group with a zero qualifier. The result of the study could be incorrect,
676 ph10 358 or the function might crash, depending on the pattern.
678     4. Caseless matching was not working for non-ASCII characters in back
679 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
680 ph10 358 It now works when Unicode Property Support is available.
682 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
683     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
684     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
685 ph10 358 truncation.
686 ph10 349
687 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
689 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
690     pointers, in case they are 64-bit values.
691 ph10 371
692     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
693     test 2 if it fails.
695 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
696 ph10 371 and a #define of that name to empty if it is not externally set. This is to
697     allow users of MSVC to set it if necessary.
699     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
700 ph10 359 the convenience functions in the pcre_get.c source file.
701 ph10 371
702 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
703     could cause overwriting and/or a crash. This command provoked a crash in
704 ph10 371 some environments:
706     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
708 ph10 360 This potential security problem was recorded as CVE-2008-2371.
709 ph10 371
710 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
711     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
712 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
713 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
714     pcretest so that it places the subject at the end of its malloc-ed buffer.
715 ph10 371
716 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
717 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
719 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
720 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
721     first line. This applied both to normal and DFA matching.
723 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
724 ph10 371 /^[^d]*?$/8 failed to match "abc".
725 ph10 351
726 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
728     17. Make it more clear in the documentation that values returned from
729 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
730 ph10 357
731 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
732 ph10 368
733 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
734     supplied by Stefan Weber. I made a further small update for 7.8 because
735 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
736     replaced by pcre_ucd.c.
737 ph10 371
738 ph10 373
739 ph10 347 Version 7.7 07-May-08
740 ph10 321 ---------------------
742     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
743 ph10 345 a string to a long long, pretend we don't even have a long long." This is
744 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
745 ph10 345
746 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
747     pre-7.6 versions, which defined a global no_arg variable instead of putting
748 ph10 332 it in the RE class. (See also #8 below.)
749 ph10 345
750     3. Remove a line of dead code, identified by coverity and reported by Nuno
751     Lopes.
753 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
754 ph10 321
755 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
756 ph10 345 of files, instead of just to the final components.
758 ph10 324 (2) If there was more than one level of directory, the subdirectories were
759     skipped unless they satisfied the include/exclude conditions. This is
760     inconsistent with GNU grep (and could even be seen as contrary to the
761     pcregrep specification - which I improved to make it absolutely clear).
762     The action now is always to scan all levels of directory, and just
763     apply the include/exclude patterns to regular files.
764 ph10 345
765 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
766 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
768 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
769 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
770 ph10 326 doesn't support NULs in patterns.
771 ph10 345
772     7. Added some missing "const"s to declarations of static tables in
773     pcre_compile.c and pcre_dfa_exec.c.
775 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
776 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
777 ph10 345 first patch. And a third patch - this was a messy problem.)
778 ph10 321
779 ph10 345 9. Applied Craig's patch to remove the use of push_back().
781 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
782     matching function regexec().
783 ph10 345
784     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
785     which, however, unlike Perl's \g{...}, are subroutine calls, not back
786 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
787     Oniguruma does).
788 ph10 345
789     12. Previously, a group with a zero repeat such as (...){0} was completely
790 ph10 335 omitted from the compiled regex. However, this means that if the group
791     was called as a subroutine from elsewhere in the pattern, things went wrong
792 ph10 345 (an internal error was given). Such groups are now left in the compiled
793     pattern, with a new opcode that causes them to be skipped at execution
794 ph10 335 time.
795 ph10 345
796 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
797     to the way PCRE behaves:
798 ph10 345
799 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
800 ph10 345
801     (b) A back reference to an unmatched subpattern matches an empty string
802 ph10 336 (Perl fails the current match path).
803 ph10 345
804 ph10 341 (c) A data ] in a character class must be notated as \] because if the
805 ph10 345 first data character in a class is ], it defines an empty class. (In
806 ph10 341 Perl it is not possible to have an empty class.) The empty class []
807     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
808     The negative empty class [^] matches any one character, independently
809     of the DOTALL setting.
810 ph10 345
811     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
812 ph10 340 non-existent subpattern following a character class starting with ']' and
813     containing () gave an internal compiling error instead of "reference to
814     non-existent subpattern". Fortunately, when the pattern did exist, the
815 ph10 345 compiled code was correct. (When scanning forwards to check for the
816 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
817 ph10 345 the class, so got the count wrong. When actually compiling, the reference
818 ph10 340 was subsequently set up correctly.)
819 ph10 345
820 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
821 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
822     other assertions are supported. I have made pcre_dfa_exec() support
823     (*FAIL).
825 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
826 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
827     cannot be changed at match time, I realized I could make a small
828     improvement to matching performance by compiling OP_ALLANY instead of
829     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
830     on the OP_ANY path.
832     17. Compiling pcretest on Windows with readline support failed without the
833 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
834 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
836 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
837 ph10 345 ncurses library to be included for pcretest when ReadLine support is
838     requested, but also to allow for it to be overridden. This patch came from
839     Daniel Bergström.
840 ph10 347
841 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
842 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
843     any errors with the current Unicode tables. Thanks to Peter Kankowski for
844     spotting this.
845 ph10 324
846 ph10 332
847 ph10 319 Version 7.6 28-Jan-08
848 ph10 300 ---------------------
850 ph10 302 1. A character class containing a very large number of characters with
851     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
852     overflow.
853 ph10 309
854     2. Patch to cut out the "long long" test in pcrecpp_unittest when
855     HAVE_LONG_LONG is not defined.
857 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
858 ph10 304 bring them up to date and include new features. This patch includes:
859 ph10 309
860 ph10 304 - Fixed PH's badly added libz and libbz2 support.
861     - Fixed a problem with static linking.
862 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
863 ph10 304 - Fixed dftables problem and added an option.
864     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
866     - Added readline support for pcretest.
867 ph10 309 - Added an listing of the option settings after cmake has run.
869 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
870     "pcre.dll" under mingw when using Configure/Make. I added stuff to
871     Makefile.am that cause it to include this special target, without
872     affecting anything else. Note that the same mingw target plus all
873     the other distribution libraries and programs are now supported
874     when configuring with CMake (see 6 below) instead of with
875     Configure/Make.
876 ph10 309
877 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
878     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
879 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
880     solves the problem, but it does no harm.
881 ph10 313
882 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
883 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
884 ph10 314 with CMake, and also correct the comment about stack recursion.
885 ph10 313
886 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
887 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
888     of a program that users should build themselves after PCRE is installed, so
889     building it automatically is not really right. What is more, it gave
890 ph10 312 trouble in some build environments.
891 ph10 300
892 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
893 ph10 308
894 ph10 319
895 ph10 298 Version 7.5 10-Jan-08
896 ph10 263 ---------------------
898     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
899     values in parens when parsing an RE using the C++ wrapper."
900 ph10 286
901 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
902     Characters greater than 255 were excluded from the class instead of being
903     included.
904 ph10 286
905     3. The same bug as (2) above applied to negated POSIX classes such as
906 ph10 265 [:^space:].
907 ph10 286
908 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
909     defined or documented. It seems to have been a typo for PCRE_STATIC, so
910 ph10 286 I have changed it.
912 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
913 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
914     first named subpattern whose name started with "a" (in other words, the
915 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
916     expected" is now given for (?&) (a zero-length name), and this patch also
917     makes it give the same error for \k'' (previously it complained that that
918     was a reference to a non-existent subpattern).
919 ph10 286
920 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
921 ph10 286 this is right because (?- can be followed by option settings as well as by
922 ph10 269 digits. I have, however, made the messages clearer.
923 ph10 286
924 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
925     than the number used in the conditional) now cause a compile-time error.
926     This is actually not compatible with Perl, which accepts such patterns, but
927     treats the conditional as always being FALSE (as PCRE used to), but it
928     seems to me that giving a diagnostic is better.
929 ph10 286
930 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
931 ph10 275 and messages.
932 ph10 286
933     9. Fix two occurrences of "backslash" in comments that should have been
934     "backspace".
936     10. Remove two redundant lines of code that can never be obeyed (their function
937     was moved elsewhere).
939     11. The program that makes PCRE's Unicode character property table had a bug
940     which caused it to generate incorrect table entries for sequences of
941 ph10 277 characters that have the same character type, but are in different scripts.
942 ph10 286 It amalgamated them into a single range, with the script of the first of
943 ph10 277 them. In other words, some characters were in the wrong script. There were
944     thirteen such cases, affecting characters in the following ranges:
945 ph10 286
946 ph10 277 U+002b0 - U+002c1
947     U+0060c - U+0060d
948 ph10 286 U+0061e - U+00612
949 ph10 277 U+0064b - U+0065e
950     U+0074d - U+0076d
951     U+01800 - U+01805
952     U+01d00 - U+01d77
953     U+01d9b - U+01dbf
954     U+0200b - U+0200f
955     U+030fc - U+030fe
956     U+03260 - U+0327f
957     U+0fb46 - U+0fbb1
958     U+10450 - U+1049d
959 ph10 286
960 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
961     compatible with GNU grep in that, if there was more than one match in a
962     line, it showed only the first of them. It now behaves in the same way as
963     GNU grep.
964 ph10 286
965     13. If the -o and -v options were combined for pcregrep, it printed a blank
966     line for every non-matching line. GNU grep prints nothing, and pcregrep now
967     does the same. The return code can be used to tell if there were any
968     non-matching lines.
970 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
972     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
973 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
974 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
975     and both kinds of lookbehind were skipped).
977 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
978 ph10 284 inclusion of <windows.h> to before rather than after the definition of
979     INVALID_FILE_ATTRIBUTES (patch from David Byron).
980 ph10 263
981 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
982 ph10 286 character property caused pcre_compile() to compile bad code, which led at
983     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
984     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
985     caused the error; without that there was no problem.
986 ph10 263
987 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
988 ph10 286
989 ph10 289 19. Added --enable-pcretest-libreadline.
990 ph10 286
991 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
992 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
993 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
994     later patch that removed the other one (the right fix) and added unit tests
995     that check the return values (which was not done before).
996 ph10 292
997 ph10 291 21. Several CMake things:
998 ph10 287
999 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1000 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
1001 ph10 288
1002 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
1003     linked with the newly-built libraries, not previously installed ones.
1004 ph10 291
1006 ph10 298
1007     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1008     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1009     UTF-8 newline character). The key issue is that the pattern starts .*;
1010     this means that the match must be either at the beginning, or after a
1011     newline. The bug was in the code for advancing after a failed match and
1012     checking that the new position followed a newline. It was not taking
1013 ph10 294 account of UTF-8 characters correctly.
1014 ph10 298
1015     23. PCRE was behaving differently from Perl in the way it recognized POSIX
1016     character classes. PCRE was not treating the sequence [:...:] as a
1017     character class unless the ... were all letters. Perl, however, seems to
1018     allow any characters between [: and :], though of course it rejects as
1019     unknown any "names" that contain non-letters, because all the known class
1020     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1021     for example, whereas PCRE did not - it did not recognize a POSIX character
1022     class. This seemed a bit dangerous, so the code has been changed to be
1023     closer to Perl. The behaviour is not identical to Perl, because PCRE will
1024     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1025     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1026     Perl does, and where it didn't before.
1028 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1029     Windows environments %n is disabled by default.
1030 ph10 292
1032 ph10 260 Version 7.4 21-Sep-07
1033 ph10 230 ---------------------
1035     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1036 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
1037     LF". That isn't really right - the whole point of the change was to try to
1038     help when there was an actual mention of one of the two characters. So now
1039     the change happens only if \r or \n (or a literal CR or LF) character is
1040 ph10 230 encountered.
1041 ph10 231
1042     2. The 32-bit options word was also used for 6 internal flags, but the numbers
1043     of both had grown to the point where there were only 3 bits left.
1044     Fortunately, there was spare space in the data structure, and so I have
1045     moved the internal flags into a new 16-bit field to free up more option
1046 ph10 230 bits.
1047 ph10 231
1048     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1049     but did not set the internal JCHANGED flag - either of these is enough to
1050     control the way the "get" function works - but the PCRE_INFO_JCHANGED
1051     facility is supposed to tell if (?J) was ever used, so now (?J) at the
1052 ph10 230 start sets both bits.
1054 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
1055     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1056 ph10 230
1057 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
1059     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1060 ph10 233 compatibility, even though it is no longer used.
1061 ph10 243
1062     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1063 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1064 ph10 259 windows.h file is present (where different names are used). [This was
1065 ph10 257 reversed later after testing - see 16 below.]
1066 ph10 243
1067     8. Changed all #include <config.h> to #include "config.h". There were also
1068 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
1069 ph10 243
1070 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
1071 ph10 243 sequence off the lines that it output.
1073     10. It was pointed out to me that arrays of string pointers cause lots of
1074     relocations when a shared library is dynamically loaded. A technique of
1075     using a single long string with a table of offsets can drastically reduce
1076     these. I have refactored PCRE in four places to do this. The result is
1077 ph10 240 dramatic:
1078 ph10 243
1079 ph10 240 Originally: 290
1080     After changing UCP table: 187
1081 ph10 243 After changing error message table: 43
1082 ph10 240 After changing table of "verbs" 36
1083     After changing table of Posix names 22
1084 ph10 243
1085 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
1086 ph10 247
1087 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1088 ph10 247 unicode-properties was also set.
1090 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1091 ph10 231
1092 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1093     checked only for CRLF.
1094 ph10 233
1095 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
1097 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1098 ph10 253
1099 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1100 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1101     entirely. This removes changes made in 7 above.
1102 ph10 256
1103 ph10 261 17. The CMake files have been updated, and there is now more information about
1104     building with CMake in the NON-UNIX-USE document.
1105 ph10 257
1106 ph10 261
1107 ph10 228 Version 7.3 28-Aug-07
1108 ph10 157 ---------------------
1110 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1111     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1112     brackets there is not right, since it causes compilers to look for an
1113     installed pcre.h, not the version that is in the source that is being
1114     compiled (which of course may be different). I have changed it back to:
1115 ph10 197
1116 ph10 189 #include "pcre.h"
1117 ph10 197
1118     I have a vague recollection that the change was concerned with compiling in
1119     different directories, but in the new build system, that is taken care of
1120     by the VPATH setting the Makefile.
1122 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1123     when the subject happened to end in the byte 0x85 (e.g. if the last
1124     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1125     characters but of course it shouldn't be taken as a newline when it is part
1126     of another character. The bug was that, for an unlimited repeat of . in
1127     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1128     characters when looking for a newline.
1129 ph10 197
1130     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1132     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1133     in debug output.
1135 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1136     long printing in the pcrecpp unittest when running under MinGW.
1137 ph10 189
1138 ph10 197 6. ESC_K was left out of the EBCDIC table.
1139 ph10 189
1140 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1141     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1142     limit also applies to "virtual nesting" when a pattern is recursive, and in
1143     this case 1000 isn't so big. I have been able to remove this limit at the
1144     expense of backing off one optimization in certain circumstances. Normally,
1145     when pcre_exec() would call its internal match() function recursively and
1146     immediately return the result unconditionally, it uses a "tail recursion"
1147     feature to save stack. However, when a subpattern that can match an empty
1148     string has an unlimited repetition quantifier, it no longer makes this
1149     optimization. That gives it a stack frame in which to save the data for
1150     checking that an empty string has been matched. Previously this was taken
1151     from the 1000-entry workspace that had been reserved. So now there is no
1152     explicit limit, but more stack is used.
1153 ph10 189
1154 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1155     syntax that is required for Windows, and which was going wrong for the
1156     pcreposix and pcrecpp parts of the library. These were overlooked when this
1157     problem was solved for the main library.
1158 ph10 197
1159 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1160     the size of patterns that contain repeated groups with explicit upper
1161     limits. As the maximum quantifier is 65535, the maximum group length was
1162     set at 30,000 so that the product of these two numbers did not overflow a
1163     32-bit integer. However, it turns out that people want to use groups that
1164     are longer than 30,000 bytes (though not repeat them that many times).
1165     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1166     made it possible to implement the integer overflow checks in a much more
1167     dynamic way, which I have now done. The artificial limitation on group
1168     length has been removed - we now have only the limit on the total length of
1169     the compiled pattern, which depends on the LINK_SIZE setting.
1170 ph10 208
1171     10. Fixed a bug in the documentation for get/copy named substring when
1172     duplicate names are permitted. If none of the named substrings are set, the
1173     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1174     empty string.
1176     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1177     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1178     because the ] is interpreted as the first data character and the
1179     terminating ] is not found. PCRE has been made compatible with Perl in this
1180     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1181     cause memory overwriting.
1183 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1184     string has been matched (to stop an infinite loop). It was not recognizing
1185 ph10 208 a conditional subpattern that could match an empty string if that
1186 ph10 206 subpattern was within another subpattern. For example, it looped when
1187 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1188 ph10 206 condition was not nested. This bug has been fixed.
1189 ph10 208
1190 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1191     past the start of the subject in the presence of bytes with the top bit
1192     set, for example "\x8aBCD".
1193 ph10 211
1194 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1195     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1196 ph10 200
1197 ph10 211 14. Optimized (?!) to (*FAIL).
1198 ph10 202
1199 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1200     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1201     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1202     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1203     does: it's just the validity check that is more restrictive.
1204 ph10 220
1205     16. Inserted checks for integer overflows during escape sequence (backslash)
1206     processing, and also fixed erroneous offset values for syntax errors during
1207     backslash processing.
1209 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1210 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1212 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1213     caused an overrun.
1214 ph10 220
1215     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1216     something other than just ASCII characters) inside a group that had an
1217     unlimited repeat caused a loop at compile time (while checking to see
1218     whether the group could match an empty string).
1220 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1221     [\P{Any}] did so. (Error in the code for printing property names.)
1222 ph10 210
1223 ph10 220 21. An orphan \E inside a character class could cause a crash.
1225     22. A repeated capturing bracket such as (A)? could cause a wild memory
1226 ph10 218 reference during compilation.
1227 ph10 220
1228     23. There are several functions in pcre_compile() that scan along a compiled
1229     expression for various reasons (e.g. to see if it's fixed length for look
1230 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1231 ph10 220 present in the pattern. These operators have additional parameters compared
1232     with \d, etc, and these were not being taken into account when moving along
1233 ph10 218 the compiled data. Specifically:
1234 ph10 220
1235     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1236     length.
1238     (b) An item such as \pL+ within a repeated group could cause crashes or
1239 ph10 218 loops.
1240 ph10 220
1241 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1242 ph10 220 "reference to non-existent subpattern" error.
1244 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1246 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1247 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1248 ph10 211
1249 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1250 ph10 218
1251 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1252 ph10 223 character were causing crashes (broken optimization).
1253 ph10 227
1254 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1255 ph10 227 \p or \P) caused a compile-time loop.
1257 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1258     break. For example, the unstudied pattern [\r\n]A does not match the string
1259     "\r\nA" because change 7.0/46 below moves the current point on by two
1260     characters after failing to match at the start. However, the pattern \nA
1261 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1262     the same is true. There doesn't seem any very clean way out of this, but
1263     what I have chosen to do makes the common cases work: PCRE now takes note
1264     of whether there can be an explicit match for \r or \n anywhere in the
1265     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1266     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1267     pattern has explicit CR or LF references.
1268 ph10 222
1269 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1270 ph10 223
1271 ph10 227
1272 ph10 189 Version 7.2 19-Jun-07
1273     ---------------------
1275 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1276     which is apparently normally available under Windows.
1277 ph10 159
1278     2. Re-jig the pcregrep tests with different newline settings in an attempt
1279     to make them independent of the local environment's newline setting.
1280 ph10 157
1281 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1282 ph10 165
1283 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1284     was not 2, because the output contained actual offsets. The recent new
1285 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1286     usable with all link sizes.
1288 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1289     stack recursion. This gives a massive performance boost under BSD, but just
1290 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1291 ph10 164 in all cases.
1292 ph10 172
1293 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1294 ph10 172
1295 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1296     recursion call. It refers to the nth most recently opened parentheses.
1297 ph10 172
1298 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1299 ph10 172 to be opened parentheses.
1301     (c) Conditions that refer to capturing parentheses can be specified
1302 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1303 ph10 172
1304 ph10 168 (d) \K resets the start of the current match so that everything before
1305 ph10 172 is not part of it.
1307 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1308 ph10 172
1309 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1310 ph10 172 reference syntax.
1311 ph10 182
1312 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1313 ph10 182 alternative starts with the same number.
1314 ph10 172
1315 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1317 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1320     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1321     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1322 ph10 170 for detecting groups that can match an empty string.
1323 ph10 159
1324 ph10 172 9. A pattern with a very large number of alternatives (more than several
1325     hundred) was running out of internal workspace during the pre-compile
1326     phase, where pcre_compile() figures out how much memory will be needed. A
1327     bit of new cunning has reduced the workspace needed for groups with
1328     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1329     workspace instead of running out of the 4096 that are available.
1330 ph10 182
1331 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1332 ph10 172
1333 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1334     The report of the bug said:
1335 ph10 182
1336 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1337     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1338 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1339 ph10 185
1340 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1341 ph10 185 it matched the wrong number of bytes.
1342 ph10 172
1343 ph10 179
1344 ph10 155 Version 7.1 24-Apr-07
1345 ph10 98 ---------------------
1347 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1348 ph10 122 that is more "standard", making use of automake and other Autotools. There
1349 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1350     on this.
1351 ph10 111
1352     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1353     for recursive directory scanning broke on some systems because the files
1354     are not scanned in any specific order and on different systems the order
1355     was different. A call to "sort" has been inserted into RunGrepTest for the
1356     approprate test as a short-term fix. In the longer term there may be an
1357 ph10 100 alternative.
1358 ph10 111
1359 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1360 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1361     people do their own conversions for various reasons). The problems
1362     concerned the use of low-level troff macros .br and .in. I have therefore
1363     removed all such uses from the man pages (some were redundant, some could
1364 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1365     HTML has been updated to handle .nf/.fi and to complain if it encounters
1366     .br or .in.
1367 ph10 111
1368 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1369 ph10 123 arranged for config.h to be included in the distribution, with the name
1370 ph10 111 config.h.generic, for the benefit of those who have to compile without
1371     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1373     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1374     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1375 ph10 127 makevp.bat for the current PCRE, using the additional files
1376 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1377 ph10 111
1378     6. A Windows user reported a minor discrepancy with test 2, which turned out
1379     to be caused by a trailing space on an input line that had got lost in his
1380 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1381 ph10 111
1382 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1383 ph10 111 that is needed.
1385 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1386     as "const" (a) because they are and (b) because it helps the PHP
1387     maintainers who have recently made a script to detect big data structures
1388 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1389     to update Builducptable as well, so it won't revert if ucptable.h is ever
1390 ph10 105 re-created.
1391 ph10 111
1392     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1393 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1394 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1395     support is not required. This saves 1.5-2K of code, which is important in
1396 ph10 107 some applications.
1397 ph10 111
1398 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1399 ph10 111 so as not to refer to the tables, even though these functions will never be
1400     called when UTF-8 support is disabled. Otherwise there are problems with a
1401     shared library.
1403 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1405     (a) It was defining its arguments as char * instead of void *.
1407 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1408     a long time ago when I wrote it, but is no longer the case.
1410 ph10 118 The emulated memove() is provided for those environments that have neither
1411 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1412 ph10 118 is clearly not the case, as these two bugs were recently reported.
1413 ph10 123
1414 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1415 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1416     pages, and it removes trailing spaces from listed files. It also creates
1417     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1418     case, it wraps all the #defines with #ifndefs. This script should be run
1419 ph10 111 before "make dist".
1420 ph10 123
1421 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1422     with Unicode property support.
1423 ph10 123
1424     (a) For a maximizing quantifier, if the two different cases of the
1425     character were of different lengths in their UTF-8 codings (there are
1426     some cases like this - I found 11), and the matching function had to
1427 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1428     were both the same length.
1429 ph10 123
1430     (b) When PCRE was configured to use the heap rather than the stack for
1431     recursion during matching, it was not correctly preserving the data for
1432     the other case of a UTF-8 character when checking ahead for a match
1433     while processing a minimizing repeat. If the check also involved
1434 ph10 115 matching a wide character, but failed, corruption could cause an
1435     erroneous result when trying to check for a repeat of the original
1436     character.
1437 ph10 123
1438 ph10 116 13. Some tidying changes to the testing mechanism:
1439 ph10 98
1440 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1441     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1442 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1443     this for UTF-8.) The configure.ac script no longer substitutes the
1444     relevant variables.
1446 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1447     with length and offset values. This means that the output is different
1448     for different internal link sizes. Test 2 is skipped for link sizes
1449     other than 2 because of this, bypassing the problem. Unfortunately,
1450     there was also a test in test 3 (the locale tests) that used /B and
1451 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1452     I have added a new /Z option to pcretest that replaces the length and
1453     offset values with spaces. This is now used to make test 3 independent
1454 ph10 122 of link size. (Test 2 will be tidied up later.)
1455 ph10 123
1456     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1457 ph10 122 segmentation fault instead of returning the appropriate error message.
1458 ph10 134
1459 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1460 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1461     This doesn't seem right; it now treats the CRLF combination as the line
1462     ending, and so does not match in that case. It's only a pattern such as ^$
1463     that would hit this one: something like ^ABC$ would have failed after \r
1464     and then tried again after \r\n.
1466 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1467 ph10 134 in an attempt to make files that differ only in their line terminators
1468     compare equal. This works on Linux.
1469 ph10 142
1470 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1471     as it exited. This is now fixed, thanks to valgrind.
1472 ph10 142
1473 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1474 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1475     was because its rules for how to advance for /g after matching an empty
1476 ph10 143 string at the end of a line did not allow for this case. They now check for
1477     it specially.
1478 ph10 150
1479     20. pcretest is supposed to handle patterns and data of any length, by
1480     extending its buffers when necessary. It was getting this wrong when the
1481 ph10 147 buffer for a data line had to be extended.
1482 ph10 150
1483 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1484 ph10 150 CRLF as a newline sequence.
1485 ph10 152
1486 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1487 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1488     I have nevertheless tidied it up.
1489 ph10 111
1490 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1491 ph10 123
1492 ph10 153 24. Added a man page for pcre-config.
1493 ph10 152
1494 ph10 153
1495 nigel 93 Version 7.0 19-Dec-06
1496     ---------------------
1498     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1499     moving to gcc 4.1.1.
1501     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1502     sys/time.h, which is documented as needed for this function. It doesn't
1503     seem to matter on Linux, but it showed up on some releases of OS X.
1505     3. It seems that there are systems where bytes whose values are greater than
1506     127 match isprint() in the "C" locale. The "C" locale should be the
1507     default when a C program starts up. In most systems, only ASCII printing
1508     characters match isprint(). This difference caused the output from pcretest
1509     to vary, making some of the tests fail. I have changed pcretest so that:
1511     (a) When it is outputting text in the compiled version of a pattern, bytes
1512     other than 32-126 are always shown as hex escapes.
1514     (b) When it is outputting text that is a matched part of a subject string,
1515     it does the same, unless a different locale has been set for the match
1516     (using the /L modifier). In this case, it uses isprint() to decide.
1518     4. Fixed a major bug that caused incorrect computation of the amount of memory
1519     required for a compiled pattern when options that changed within the
1520     pattern affected the logic of the preliminary scan that determines the
1521     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1522     that the computed length was too small. The symptoms of this bug were
1523     either the PCRE error "internal error: code overflow" from pcre_compile(),
1524     or a glibc crash with a message such as "pcretest: free(): invalid next
1525     size (fast)". Examples of patterns that provoked this bug (shown in
1526     pcretest format) are:
1528     /(?-x: )/x
1529     /(?x)(?-x: \s*#\s*)/
1530     /((?i)[\x{c0}])/8
1531     /(?i:[\x{c0}])/8
1533     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1534     is now done differently.
1536     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1537     wrapper classes; (b) implement a new function in the C++ scanner that is
1538     more efficient than the old way of doing things because it avoids levels of
1539     recursion in the regex matching; (c) add a paragraph to the documentation
1540     for the FullMatch() function.
1542     6. The escape sequence \n was being treated as whatever was defined as
1543     "newline". Not only was this contrary to the documentation, which states
1544     that \n is character 10 (hex 0A), but it also went horribly wrong when
1545     "newline" was defined as CRLF. This has been fixed.
1547     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1548     was being set to -1 for the "end of line" case (supposedly a value that no
1549     character can have). Though this value is never used (the check for end of
1550     line is "zero bytes in current character"), it caused compiler complaints.
1551     I've changed it to 0xffffffff.
1553     8. In pcre_version.c, the version string was being built by a sequence of
1554     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1555     string (as it is for production releases) called a macro with an empty
1556     argument. The C standard says the result of this is undefined. The gcc
1557     compiler treats it as an empty string (which was what was wanted) but it is
1558     reported that Visual C gives an error. The source has been hacked around to
1559     avoid this problem.
1561     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1562     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1563     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1564     of them did).
1566     10. Originally, pcretest opened its input and output without "b"; then I was
1567     told that "b" was needed in some environments, so it was added for release
1568     5.0 to both the input and output. (It makes no difference on Unix-like
1569     systems.) Later I was told that it is wrong for the input on Windows. I've
1570     now abstracted the modes into two macros, to make it easier to fiddle with
1571     them, and removed "b" from the input mode under Windows.
1573     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1575     12. Added -help and --help to pcretest as an official way of being reminded
1576     of the options.
1578     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1579     and pcrecpp.cc because they annoy compilers at high warning levels.
1581     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1583     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1584     scripts are not C programs :-) and which was not noticed because it works
1585     on Linux.
1587     16. pcretest is supposed to handle any length of pattern and data line (as one
1588     line or as a continued sequence of lines) by extending its input buffer if
1589     necessary. This feature was broken for very long pattern lines, leading to
1590     a string of junk being passed to pcre_compile() if the pattern was longer
1591     than about 50K.
1593     17. I have done a major re-factoring of the way pcre_compile() computes the
1594     amount of memory needed for a compiled pattern. Previously, there was code
1595     that made a preliminary scan of the pattern in order to do this. That was
1596     OK when PCRE was new, but as the facilities have expanded, it has become
1597     harder and harder to keep it in step with the real compile phase, and there
1598     have been a number of bugs (see for example, 4 above). I have now found a
1599     cunning way of running the real compile function in a "fake" mode that
1600     enables it to compute how much memory it would need, while actually only
1601     ever using a few hundred bytes of working memory and without too many
1602     tests of the mode. This should make future maintenance and development
1603     easier. A side effect of this work is that the limit of 200 on the nesting
1604     depth of parentheses has been removed (though this was never a serious
1605     limitation, I suspect). However, there is a downside: pcre_compile() now
1606     runs more slowly than before (30% or more, depending on the pattern). I
1607     hope this isn't a big issue. There is no effect on runtime performance.
1609     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1610     newline (only possible for the last line of a file) and it was a
1611     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1613     19. Added additional timing features to pcretest. (1) The -tm option now times
1614     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1615     separate command line item, by a number that specifies the number of
1616     repeats to use when timing. The default is 50000; this gives better
1617     precision, but takes uncomfortably long for very large patterns.
1619     20. Extended pcre_study() to be more clever in cases where a branch of a
1620     subpattern has no definite first character. For example, (a*|b*)[cd] would
1621     previously give no result from pcre_study(). Now it recognizes that the
1622     first character must be a, b, c, or d.
1624     21. There was an incorrect error "recursive call could loop indefinitely" if
1625     a subpattern (or the entire pattern) that was being tested for matching an
1626     empty string contained only one non-empty item after a nested subpattern.
1627     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1628     incorrectly, because the \d was being skipped in the check.
1630     22. The pcretest program now has a new pattern option /B and a command line
1631     option -b, which is equivalent to adding /B to every pattern. This causes
1632     it to show the compiled bytecode, without the additional information that
1633     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1634     is the same as /B/I).
1636     23. A new optimization is now able automatically to treat some sequences such
1637     as a*b as a*+b. More specifically, if something simple (such as a character
1638     or a simple class like \d) has an unlimited quantifier, and is followed by
1639     something that cannot possibly match the quantified thing, the quantifier
1640     is automatically "possessified".
1642     24. A recursive reference to a subpattern whose number was greater than 39
1643     went wrong under certain circumstances in UTF-8 mode. This bug could also
1644     have affected the operation of pcre_study().
1646     25. Realized that a little bit of performance could be had by replacing
1647     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1649     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1651     27. Possessive quantifiers such as a++ were previously implemented by turning
1652     them into atomic groups such as ($>a+). Now they have their own opcodes,
1653     which improves performance. This includes the automatically created ones
1654     from 23 above.
1656     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1657     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1658     the first matched character to be a colon. This applied both to named and
1659     numbered groups.
1661     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1663     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1664     building PCRE on Windows easier, so I have included it in the distribution.
1666     31. There is now a check in pcretest against a ridiculously large number being
1667     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1668     loop, the loop is abandoned.
1670     32. Forward references to subpatterns in conditions such as (?(2)...) where
1671     subpattern 2 is defined later cause pcre_compile() to search forwards in
1672     the pattern for the relevant set of parentheses. This search went wrong
1673     when there were unescaped parentheses in a character class, parentheses
1674     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1676     33. "Subroutine" calls and backreferences were previously restricted to
1677     referencing subpatterns earlier in the regex. This restriction has now
1678     been removed.
1680     34. Added a number of extra features that are going to be in Perl 5.10. On the
1681     whole, these are just syntactic alternatives for features that PCRE had
1682     previously implemented using the Python syntax or my own invention. The
1683     other formats are all retained for compatibility.
1685     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1686     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1687     also .NET compatible.
1689     (b) A recursion or subroutine call to a named group can now be defined as
1690     (?&name) as well as (?P>name).
1692     (c) A backreference to a named group can now be defined as \k<name> or
1693     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1694     5.10, are also .NET compatible.
1696     (d) A conditional reference to a named group can now use the syntax
1697     (?(<name>) or (?('name') as well as (?(name).
1699     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1700     groups (named and numbered) that are never evaluated inline, but can be
1701     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1702     is always false. There may be only one alternative in such a group.
1704     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1705     as the simple (?(R). The condition is true only if the most recent
1706     recursion is that of the given number or name. It does not search out
1707     through the entire recursion stack.
1709     (g) The escape \gN or \g{N} has been added, where N is a positive or
1710     negative number, specifying an absolute or relative reference.
1712     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1713     some "unreachable code" warnings.
1715     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1716     things, this adds five new scripts.
1718     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1719     There were also incompatibilities regarding the handling of \Q..\E inside
1720     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1721     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1723     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1724     matches an empty string, and forcibly breaks the loop. There were bugs in
1725     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1726     against aaaa the result was just "a" rather than "aaaa", for example. Two
1727     separate and independent bugs (that affected different cases) have been
1728     fixed.
1730     39. Refactored the code to abolish the use of different opcodes for small
1731     capturing bracket numbers. This is a tidy that I avoided doing when I
1732     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1733     The new approach is not only tidier, it makes it possible to reduce the
1734     memory needed to fix the previous bug (38).
1736     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1737     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1738     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1739     mode.
1741     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1742     report.
1744     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1745     copy construction and assignment in the C++ wrapper.
1747     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1748     couple of bugs that could have given wrong results in the "--newline=crlf"
1749     case.
1751     44. Added a number of casts and did some reorganization of signed/unsigned int
1752     variables following suggestions from Dair Grant. Also renamed the variable
1753     "this" as "item" because it is a C++ keyword.
1755     45. Arranged for dftables to add
1757     #include "pcre_internal.h"
1759     to pcre_chartables.c because without it, gcc 4.x may remove the array
1760     definition from the final binary if PCRE is built into a static library and
1761     dead code stripping is activated.
1763     46. For an unanchored pattern, if a match attempt fails at the start of a
1764     newline sequence, and the newline setting is CRLF or ANY, and the next two
1765     characters are CRLF, advance by two characters instead of one.
1768 nigel 91 Version 6.7 04-Jul-06
1769     ---------------------
1771     1. In order to handle tests when input lines are enormously long, pcretest has
1772     been re-factored so that it automatically extends its buffers when
1773     necessary. The code is crude, but this _is_ just a test program. The
1774     default size has been increased from 32K to 50K.
1776     2. The code in pcre_study() was using the value of the re argument before
1777     testing it for NULL. (Of course, in any sensible call of the function, it
1778     won't be NULL.)
1780     3. The memmove() emulation function in pcre_internal.h, which is used on
1781     systems that lack both memmove() and bcopy() - that is, hardly ever -
1782     was missing a "static" storage class specifier.
1784     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1785     containing an extended class (one that cannot be represented by a bitmap
1786     because it contains high-valued characters or Unicode property items, e.g.
1787     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1788     pattern, but PCRE should not loop if you do not (it no longer does).
1789     [Detail: two cases were found: (a) a repeated subpattern containing an
1790     extended class; (b) a recursive reference to a subpattern that followed a
1791     previous extended class. It wasn't skipping over the extended class
1792     correctly when UTF-8 mode was not set.]
1794     5. A negated single-character class was not being recognized as fixed-length
1795     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1796     compile error "lookbehind assertion is not fixed length".
1798     6. The RunPerlTest auxiliary script was showing an unexpected difference
1799     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1800     write a Perl script that can interpret lines of an input file either as
1801     byte characters or as UTF-8, which is what "perltest" was being required to
1802     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1803     can't do is switch easily at run time between having the "use utf8;" pragma
1804     or not. In the end, I fudged it by using the RunPerlTest script to insert
1805     "use utf8;" explicitly for the UTF-8 tests.
1807     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1808     the end of the subject string, contrary to the documentation and to what
1809     Perl does. This was true of both matching functions. Now it matches only at
1810     the start of the subject and immediately after *internal* newlines.
1812     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1813     a pointer to an int instead of a pointer to an unsigned long int. This
1814     caused problems on 64-bit systems.
1816     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1817     instance of the 'standard' template library not being so standard".
1819     10. There was no check on the number of named subpatterns nor the maximum
1820     length of a subpattern name. The product of these values is used to compute
1821     the size of the memory block for a compiled pattern. By supplying a very
1822     long subpattern name and a large number of named subpatterns, the size
1823     computation could be caused to overflow. This is now prevented by limiting
1824     the length of names to 32 characters, and the number of named subpatterns
1825     to 10,000.
1827     11. Subpatterns that are repeated with specific counts have to be replicated in
1828     the compiled pattern. The size of memory for this was computed from the
1829     length of the subpattern and the repeat count. The latter is limited to
1830     65535, but there was no limit on the former, meaning that integer overflow
1831     could in principle occur. The compiled length of a repeated subpattern is
1832     now limited to 30,000 bytes in order to prevent this.
1834     12. Added the optional facility to have named substrings with the same name.
1836     13. Added the ability to use a named substring as a condition, using the
1837     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1838     are numbers (not recommended). Forward references are permitted.
1840     14. Added forward references in named backreferences (if you see what I mean).
1842     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1843     pattern could run off the end of the subject. For example, the pattern
1844     "(?s)(.{1,5})"8 did this with the subject "ab".
1846     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1847     PCRE_CASELESS was set when matching characters that were quantified with ?
1848     or *.
1850     17. A character class other than a single negated character that had a minimum
1851     but no maximum quantifier - for example [ab]{6,} - was not handled
1852     correctly by pce_dfa_exec(). It would match only one character.
1854     18. A valid (though odd) pattern that looked like a POSIX character
1855     class but used an invalid character after [ (for example [[,abc,]]) caused
1856     pcre_compile() to give the error "Failed: internal error: code overflow" or
1857     in some cases to crash with a glibc free() error. This could even happen if
1858     the pattern terminated after [[ but there just happened to be a sequence of
1859     letters, a binary zero, and a closing ] in the memory that followed.
1861     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1862     over the years. Originally (before any Unicode support), just the bottom 8
1863     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1864     output from "man perlunicode" includes this:
1866     The regular expression compiler produces polymorphic opcodes. That
1867     is, the pattern adapts to the data and automatically switches to
1868     the Unicode character scheme when presented with Unicode data--or
1869     instead uses a traditional byte scheme when presented with byte
1870     data.
1872     Sadly, a wide octal escape does not cause a switch, and in a string with
1873     no other multibyte characters, these octal escapes are treated as before.
1874     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1875     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1876     Unicode string.
1878     I have not perpetrated such confusion in PCRE. Up till now, it took just
1879     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1880     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1881     translate to the appropriate multibyte character.
1883     29. Applied some refactoring to reduce the number of warnings from Microsoft
1884     and Borland compilers. This has included removing the fudge introduced
1885     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1886     a warning about an unused variable.
1888     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1889     characters since release 4.0, because Perl (from release 5.004) does not.
1890     [Or at least, is documented not to: some releases seem to be in conflict
1891     with the documentation.] However, when a pattern was studied with
1892     pcre_study() and all its branches started with \s, PCRE still included VT
1893     as a possible starting character. Of course, this did no harm; it just
1894     caused an unnecessary match attempt.
1896     22. Removed a now-redundant internal flag bit that recorded the fact that case
1897     dependency changed within the pattern. This was once needed for "required
1898     byte" processing, but is no longer used. This recovers a now-scarce options
1899     bit. Also moved the least significant internal flag bit to the most-
1900     significant bit of the word, which was not previously used (hangover from
1901     the days when it was an int rather than a uint) to free up another bit for
1902     the future.
1904     23. Added support for CRLF line endings as well as CR and LF. As well as the
1905     default being selectable at build time, it can now be changed at runtime
1906     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1907     specify that it is scanning data with non-default line endings.
1909     24. Changed the definition of CXXLINK to make it agree with the definition of
1910     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1912     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1913     recursions. This makes a big different to stack usage for some patterns.
1915     26. If a subpattern containing a named recursion or subroutine reference such
1916     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1917     the space required for the compiled pattern went wrong and gave too small a
1918     value. Depending on the environment, this could lead to "Failed: internal
1919     error: code overflow at offset 49" or "glibc detected double free or
1920     corruption" errors.
1922     27. Applied patches from Google (a) to support the new newline modes and (b) to
1923     advance over multibyte UTF-8 characters in GlobalReplace.
1925     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1926     difference for some implementation of PCRE in some Windows version.
1928     29. Added some extra testing facilities to pcretest:
1930     \q<number> in a data line sets the "match limit" value
1931     \Q<number> in a data line sets the "match recursion limt" value
1932     -S <number> sets the stack size, where <number> is in megabytes
1934     The -S option isn't available for Windows.
1937 nigel 89 Version 6.6 06-Feb-06
1938     ---------------------
1940     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1941     in pcreposix.h. I have copied the definition from pcre.h.
1943     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1944     because pcre.h is no longer a built file.
1946     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1947     not normally included in the compiled code.
1950 nigel 87 Version 6.5 01-Feb-06
1951     ---------------------
1953     1. When using the partial match feature with pcre_dfa_exec(), it was not
1954     anchoring the second and subsequent partial matches at the new starting
1955     point. This could lead to incorrect results. For example, with the pattern
1956     /1234/, partially matching against "123" and then "a4" gave a match.
1958     2. Changes to pcregrep:
1960     (a) All non-match returns from pcre_exec() were being treated as failures
1961     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1962     error message is output. Some extra information is given for the
1964     probably the only errors that are likely to be caused by users (by
1965     specifying a regex that has nested indefinite repeats, for instance).
1966     If there are more than 20 of these errors, pcregrep is abandoned.
1968     (b) A binary zero was treated as data while matching, but terminated the
1969     output line if it was written out. This has been fixed: binary zeroes
1970     are now no different to any other data bytes.
1972     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1973     used to set a locale for matching. The --locale=xxxx long option has
1974     been added (no short equivalent) to specify a locale explicitly on the
1975     pcregrep command, overriding the environment variables.
1977     (d) When -B was used with -n, some line numbers in the output were one less
1978     than they should have been.
1980     (e) Added the -o (--only-matching) option.
1982     (f) If -A or -C was used with -c (count only), some lines of context were
1983     accidentally printed for the final match.
1985     (g) Added the -H (--with-filename) option.
1987     (h) The combination of options -rh failed to suppress file names for files
1988     that were found from directory arguments.
1990     (i) Added the -D (--devices) and -d (--directories) options.
1992     (j) Added the -F (--fixed-strings) option.
1994     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1996     (l) Added the --colo(u)r option.
1998     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1999     is not present by default.
2001     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2002     items such as (?R) or (?1), when the recursion could match a number of
2003     alternatives. If it matched one of the alternatives, but subsequently,
2004     outside the recursion, there was a failure, the code tried to back up into
2005     the recursion. However, because of the way PCRE is implemented, this is not
2006     possible, and the result was an incorrect result from the match.
2008     In order to prevent this happening, the specification of recursion has
2009     been changed so that all such subpatterns are automatically treated as
2010     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2012     4. I had overlooked the fact that, in some locales, there are characters for
2013     which isalpha() is true but neither isupper() nor islower() are true. In
2014     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2015     and ordfeminine) are like this. This affected the treatment of \w and \W
2016     when they appeared in character classes, but not when they appeared outside
2017     a character class. The bit map for "word" characters is now created
2018     separately from the results of isalnum() instead of just taking it from the
2019     upper, lower, and digit maps. (Plus the underscore character, of course.)
2021     5. The above bug also affected the handling of POSIX character classes such as
2022     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2023     permanent tables. Instead, the bit maps for such a class were previously
2024     created as the appropriate unions of the upper, lower, and digit bitmaps.
2025     Now they are created by subtraction from the [[:word:]] class, which has
2026     its own bitmap.
2028     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2029     It is created by subtracting the vertical space characters (\x09, \x0a,
2030     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2031     subtraction was done in the overall bitmap for a character class, meaning
2032     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2033     be recognized. This bug has been fixed.
2035     7. Patches from the folks at Google:
2037     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2038     real life, but is still worth protecting against".
2040     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2041     regular expressions".
2043     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2044     have it.
2046     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2047     "configure" and the latter not, in order to fix a problem somebody had
2048     with compiling the Arg class on HP-UX.
2050     (e) Improve the error-handling of the C++ wrapper a little bit.
2052     (f) New tests for checking recursion limiting.
2054     8. The pcre_memmove() function, which is used only if the environment does not
2055     have a standard memmove() function (and is therefore rarely compiled),
2056     contained two bugs: (a) use of int instead of size_t, and (b) it was not
2057     returning a result (though PCRE never actually uses the result).
2059     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2060     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2061     returned instead of calling malloc() with an overflowing number that would
2062     most likely cause subsequent chaos.
2064     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2066     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2067     with this option is matched, the nmatch and pmatch options of regexec() are
2068     ignored.
2070     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2071     provided in case anyone wants to the the POSIX interface with UTF-8
2072     strings.
2074     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2075     C++ linking (needed for some HP-UX environments).
2077     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2078     (unused parameter) and in the pcre_printint() function (omitted "default"
2079     switch label when the default is to do nothing).
2081     15. Added some code to make it possible, when PCRE is compiled as a C++
2082     library, to replace subject pointers for pcre_exec() with a smart pointer
2083     class, thus making it possible to process discontinuous strings.
2085     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2086     much the same function. They were added by different people who were trying
2087     to make PCRE easy to compile on non-Unix systems. It has been suggested
2088     that PCRE_EXPORT be abolished now that there is more automatic apparatus
2089     for compiling on Windows systems. I have therefore replaced it with
2090     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2091     defaults to "extern" for C or "extern C" for C++, which works fine on
2092     Unix-like systems. It is now possible to override the value of PCRE_DATA_
2093     SCOPE with something explicit in config.h. In addition:
2095     (a) pcreposix.h still had just "extern" instead of either of these macros;
2096     I have replaced it with PCRE_DATA_SCOPE.
2098     (b) Functions such as _pcre_xclass(), which are internal to the library,
2099     but external in the C sense, all had PCRE_EXPORT in their definitions.
2100     This is apparently wrong for the Windows case, so I have removed it.
2101     (It makes no difference on Unix-like systems.)
2103     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2104     of recursive calls to match(). This is different to MATCH_LIMIT because
2105     that limits the total number of calls to match(), not all of which increase
2106     the depth of recursion. Limiting the recursion depth limits the amount of
2107     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2108     when PCRE is compiled, and changed at run time. A patch from Google adds
2109     this functionality to the C++ interface.
2111     18. Changes to the handling of Unicode character properties:
2113     (a) Updated the table to Unicode 4.1.0.
2115     (b) Recognize characters that are not in the table as "Cn" (undefined).
2117     (c) I revised the way the table is implemented to a much improved format
2118     which includes recognition of ranges. It now supports the ranges that
2119     are defined in UnicodeData.txt, and it also amalgamates other
2120     characters into ranges. This has reduced the number of entries in the
2121     table from around 16,000 to around 3,000, thus reducing its size
2122     considerably. I realized I did not need to use a tree structure after
2123     all - a binary chop search is just as efficient. Having reduced the
2124     number of entries, I extended their size from 6 bytes to 8 bytes to
2125     allow for more data.
2127     (d) Added support for Unicode script names via properties such as \p{Han}.
2129     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2130     matching that character.
2132     20. When matching a repeated Unicode property with a minimum greater than zero,
2133     (for example \pL{2,}), PCRE could look past the end of the subject if it
2134     reached it while seeking the minimum number of characters. This could
2135     happen only if some of the characters were more than one byte long, because
2136     there is a check for at least the minimum number of bytes.
2138     21. Refactored the implementation of \p and \P so as to be more general, to
2139     allow for more different types of property in future. This has changed the
2140     compiled form incompatibly. Anybody with saved compiled patterns that use
2141     \p or \P will have to recompile them.
2143     22. Added "Any" and "L&" to the supported property types.
2145     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2146     but give a compile time error if the value is greater than 0xff.
2148     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2149     accidentally not being installed or uninstalled.
2151     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2152     made were to insert the current release number. This seemed silly, because
2153     it made things harder for people building PCRE on systems that don't run
2154     "configure". I have turned pcre.h into a distributed file, no longer built
2155     by "configure", with the version identification directly included. There is
2156     no longer a pcre.h.in file.
2158     However, this change necessitated a change to the pcre-config script as
2159     well. It is built from pcre-config.in, and one of the substitutions was the
2160     release number. I have updated configure.ac so that ./configure now finds
2161     the release number by grepping pcre.h.
2163     26. Added the ability to run the tests under valgrind.
2166 nigel 85 Version 6.4 05-Sep-05
2167     ---------------------
2169     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2170     "--" to be printed when multiple files were scanned, even when none of the
2171     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2172     consider it to be a bug, and have restored the previous behaviour.
2174     2. A couple of code tidies to get rid of compiler warnings.
2176     3. The pcretest program used to cheat by referring to symbols in the library
2177     whose names begin with _pcre_. These are internal symbols that are not
2178     really supposed to be visible externally, and in some environments it is
2179     possible to suppress them. The cheating is now confined to including
2180     certain files from the library's source, which is a bit cleaner.
2182     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2183     file's purpose clearer.
2185     5. Reorganized pcre_ucp_findchar().
2188 nigel 83 Version 6.3 15-Aug-05
2189     ---------------------
2191     1. The file libpcre.pc.in did not have general read permission in the tarball.
2193     2. There were some problems when building without C++ support:
2195     (a) If C++ support was not built, "make install" and "make test" still
2196     tried to test it.
2198     (b) There were problems when the value of CXX was explicitly set. Some
2199     changes have been made to try to fix these, and ...
2201     (c) --disable-cpp can now be used to explicitly disable C++ support.
2203     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2204     backslash in a target when C++ was disabled. This confuses some
2205     versions of "make", apparently. Using an intermediate variable solves
2206     this. (Same for CPP_LOBJ.)
2208     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2209     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2210     necessary on certain architectures.
2212     4. Added a setting of -export-symbols-regex to the link command to remove
2213     those symbols that are exported in the C sense, but actually are local
2214     within the library, and not documented. Their names all begin with
2215     "_pcre_". This is not a perfect job, because (a) we have to except some
2216     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2217     available (and never for static libraries). I have made a note to try to
2218     find a way round (a) in the future.
2221 nigel 81 Version 6.2 01-Aug-05
2222     ---------------------
2224     1. There was no test for integer overflow of quantifier values. A construction
2225     such as {1111111111111111} would give undefined results. What is worse, if
2226     a minimum quantifier for a parenthesized subpattern overflowed and became
2227     negative, the calculation of the memory size went wrong. This could have
2228     led to memory overwriting.
2230     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2232     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2233     operating environments where this matters.
2235     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2236     PCRE options from within the C++ wrapper.
2238     5. Named capturing subpatterns were not being correctly counted when a pattern
2239     was compiled. This caused two problems: (a) If there were more than 100
2240     such subpatterns, the calculation of the memory needed for the whole
2241     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2242     back references of the form \12, where the number was greater than 9, were
2243     not recognized as back references, even though there were sufficient
2244     previous subpatterns.
2246     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2247     versions of gcc, e.g. 2.95.4.
2250 nigel 79 Version 6.1 21-Jun-05
2251     ---------------------
2253     1. There was one reference to the variable "posix" in pcretest.c that was not
2254     surrounded by "#if !defined NOPOSIX".
2256     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2257     the cross-check on the old pcre_info() function, for the benefit of the
2258     cut-down version of PCRE that is currently imported into Exim.
2260     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2261     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2262     patterns that start (?i) but I don't think that matters. The use of (?i) is
2263     just an example; this all applies to the other options as well.
2265     4. Since libtool seems to echo the compile commands it is issuing, the output
2266     from "make" can be reduced a bit by putting "@" in front of each libtool
2267     compile command.
2269     5. Patch from the folks at Google for configure.in to be a bit more thorough
2270     in checking for a suitable C++ installation before trying to compile the
2271     C++ stuff. This should fix a reported problem when a compiler was present,
2272     but no suitable headers.
2274     6. The man pages all had just "PCRE" as their title. I have changed them to
2275     be the relevant file name. I have also arranged that these names are
2276     retained in the file doc/pcre.txt, which is a concatenation in text format
2277     of all the man pages except the little individual ones for each function.
2279     7. The NON-UNIX-USE file had not been updated for the different set of source
2280     files that come with release 6. I also added a few comments about the C++
2281     wrapper.
2284 nigel 77 Version 6.0 07-Jun-05
2285     ---------------------
2287     1. Some minor internal re-organization to help with my DFA experiments.
2289     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2290     didn't matter for the library itself when fully configured, but did matter
2291     when compiling without UCP support, or within Exim, where the ucp files are
2292     not imported.
2294     3. Refactoring of the library code to split up the various functions into
2295     different source modules. The addition of the new DFA matching code (see
2296     below) to a single monolithic source would have made it really too
2297     unwieldy, quite apart from causing all the code to be include in a
2298     statically linked application, when only some functions are used. This is
2299     relevant even without the DFA addition now that patterns can be compiled in
2300     one application and matched in another.
2302     The downside of splitting up is that there have to be some external
2303     functions and data tables that are used internally in different modules of
2304     the library but which are not part of the API. These have all had their
2305     names changed to start with "_pcre_" so that they are unlikely to clash
2306     with other external names.
2308     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2309     a different (DFA) algorithm. Although it is slower than the original
2310     function, it does have some advantages for certain types of matching
2311     problem.
2313     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2314     including restarting after a partial match.
2316     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2317     defined when compiling for Windows was sent to me. I have put it into the
2318     code, though I have no means of testing or verifying it.
2320     7. Added the pcre_refcount() auxiliary function.
2322     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2323     match before or at the first newline in the subject string. In pcretest,
2324     the /f option on a pattern can be used to set this.
2326     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2327     would behave wrongly. This has been present in PCRE since release 4.0.
2329     10. A number of changes to the pcregrep command:
2331     (a) Refactored how -x works; insert ^(...)$ instead of setting
2332     PCRE_ANCHORED and checking the length, in preparation for adding
2333     something similar for -w.
2335     (b) Added the -w (match as a word) option.
2337     (c) Refactored the way lines are read and buffered so as to have more
2338     than one at a time available.
2340     (d) Implemented a pcregrep test script.
2342     (e) Added the -M (multiline match) option. This allows patterns to match
2343     over several lines of the subject. The buffering ensures that at least
2344     8K, or the rest of the document (whichever is the shorter) is available
2345     for matching (and similarly the previous 8K for lookbehind assertions).
2347     (f) Changed the --help output so that it now says
2349     -w, --word-regex(p)
2351     instead of two lines, one with "regex" and the other with "regexp"
2352     because that confused at least one person since the short forms are the
2353     same. (This required a bit of code, as the output is generated
2354     automatically from a table. It wasn't just a text change.)
2356     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2357     option but starts with a hyphen. Could be a pattern or a path name
2358     starting with a hyphen, for instance.
2360     (h) "-" can be given as a file name to represent stdin.
2362     (i) When file names are being printed, "(standard input)" is used for
2363     the standard input, for compatibility with GNU grep. Previously
2364     "<stdin>" was used.
2366     (j) The option --label=xxx can be used to supply a name to be used for
2367     stdin when file names are being printed. There is no short form.
2369     (k) Re-factored the options decoding logic because we are going to add
2370     two more options that take data. Such options can now be given in four
2371     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2373     (l) Added the -A, -B, and -C options for requesting that lines of context
2374     around matches be printed.
2376     (m) Added the -L option to print the names of files that do not contain
2377     any matching lines, that is, the complement of -l.
2379     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2380     continue to scan other files.
2382     (o) The -s option was incorrectly implemented. For compatibility with other
2383     greps, it now suppresses the error message for a non-existent or non-
2384     accessible file (but not the return code). There is a new option called
2385     -q that suppresses the output of matching lines, which was what -s was
2386     previously doing.
2388     (p) Added --include and --exclude options to specify files for inclusion
2389     and exclusion when recursing.
2391     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2392     Hopefully, it now does.
2394     12. Missing cast in pcre_study().
2396     13. Added an "uninstall" target to the makefile.
2398     14. Replaced "extern" in the function prototypes in Makefile.in with
2399     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2400     world, but is set differently for Windows.
2402     15. Added a second compiling function called pcre_compile2(). The only
2403     difference is that it has an extra argument, which is a pointer to an
2404     integer error code. When there is a compile-time failure, this is set
2405     non-zero, in addition to the error test pointer being set to point to an
2406     error message. The new argument may be NULL if no error number is required
2407     (but then you may as well call pcre_compile(), which is now just a
2408     wrapper). This facility is provided because some applications need a
2409     numeric error indication, but it has also enabled me to tidy up the way
2410     compile-time errors are handled in the POSIX wrapper.
2412     16. Added VPATH=.libs to the makefile; this should help when building with one
2413     prefix path and installing with another. (Or so I'm told by someone who
2414     knows more about this stuff than I do.)
2416     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2417     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2418     match everything, including newlines. This is not POSIX-compatible, but
2419     somebody wanted the feature. From pcretest it can be activated by using
2420     both the P and the s flags.
2422     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2424     19. libpcre.pc was being incorrectly installed as executable.
2426     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2427     it now also looks for '\r' so that it will work unmodified on Windows.
2429     21. Added Google's contributed C++ wrapper to the distribution.
2431     22. Added some untidy missing memory free() calls in pcretest, to keep
2432     Electric Fence happy when testing.
2436 nigel 75 Version 5.0 13-Sep-04
2437     ---------------------
2439     1. Internal change: literal characters are no longer packed up into items
2440     containing multiple characters in a single byte-string. Each character
2441     is now matched using a separate opcode. However, there may be more than one
2442     byte in the character in UTF-8 mode.
2444     2. The pcre_callout_block structure has two new fields: pattern_position and
2445     next_item_length. These contain the offset in the pattern to the next match
2446     item, and its length, respectively.
2448     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2449     insertion of callouts before each pattern item. Added the /C option to
2450     pcretest to make use of this.
2452     4. On the advice of a Windows user, the lines
2454     #if defined(_WIN32) || defined(WIN32)
2455     _setmode( _fileno( stdout ), 0x8000 );
2456     #endif /* defined(_WIN32) || defined(WIN32) */
2458     have been added to the source of pcretest. This apparently does useful
2459     magic in relation to line terminators.
2461     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2462     for the benefit of those environments where the "b" makes a difference.
2464     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2465     to know about it. I have put a hack into configure.in that adds in code
2466     to set GCC=yes if CC=icc. This seems to end up at a point in the
2467     generated configure script that is early enough to affect the setting of
2468     compiler options, which is what is needed, but I have no means of testing
2469     whether it really works. (The user who reported this had patched the
2470     generated configure script, which of course I cannot do.)
2472     LATER: After change 22 below (new libtool files), the configure script
2473     seems to know about icc (and also ecc). Therefore, I have commented out
2474     this hack in configure.in.
2476     7. Added support for pkg-config (2 patches were sent in).
2478     8. Negated POSIX character classes that used a combination of internal tables
2479     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2480     [[:^ascii]]. Typically, they would match almost any characters. The other
2481     POSIX classes were not broken in this way.
2483     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2484     to find the match, as PCRE was deluded into thinking that the match had to
2485     start at the start point or following a newline. The same bug applied to
2486     patterns with negative forward assertions or any backward assertions
2487     preceding ".*" at the start, unless the pattern required a fixed first
2488     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2490     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2491     starting at the last subject character, bytes beyond the end of the subject
2492     string were read.
2494     11. Renamed the variable "class" as "classbits" to make life easier for C++
2495     users. (Previously there was a macro definition, but it apparently wasn't
2496     enough.)
2498     12. Added the new field "tables" to the extra data so that tables can be passed
2499     in at exec time, or the internal tables can be re-selected. This allows
2500     a compiled regex to be saved and re-used at a later time by a different
2501     program that might have everything at different addresses.
2503     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2504     -R library as well as a -L library.
2506     14. The debugging options of pcretest (-d on the command line or D on a
2507     pattern) showed incorrect output for anything following an extended class
2508     that contained multibyte characters and which was followed by a quantifier.
2510     15. Added optional support for general category Unicode character properties
2511     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2512     support. It adds about 90K to the size of the library. The meanings of the
2513     inbuilt class escapes such as \d and \s have NOT been changed.
2515     16. Updated pcredemo.c to include calls to free() to release the memory for the
2516     compiled pattern.
2518     17. The generated file chartables.c was being created in the source directory
2519     instead of in the building directory. This caused the build to fail if the
2520     source directory was different from the building directory, and was
2521     read-only.
2523     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2524     file. No doubt somebody will tell me if they don't make sense... Also added
2525     Dan Mooney's comments about building on OpenVMS.
2527     19. Added support for partial matching via the PCRE_PARTIAL option for
2528     pcre_exec() and the \P data escape in pcretest.
2530     20. Extended pcretest with 3 new pattern features:
2532     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2533     write the compiled pattern to the file whose name is "rest-of-line".
2534     This is a straight binary dump of the data, with the saved pointer to
2535     the character tables forced to be NULL. The study data, if any, is
2536     written too. After writing, pcretest reads a new pattern.
2538     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2539     compiled pattern from the given file. There must not be any
2540     occurrences of "<" in the file name (pretty unlikely); if there are,
2541     pcretest will instead treat the initial "<" as a pattern delimiter.
2542     After reading in the pattern, pcretest goes on to read data lines as
2543     usual.
2545     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2546     and 16-bit fields in a compiled pattern, to simulate a pattern that
2547     was compiled on a host of opposite endianness.
2549     21. The pcre-exec() function can now cope with patterns that were compiled on
2550     hosts of opposite endianness, with this restriction:
2552     As for any compiled expression that is saved and used later, the tables
2553     pointer field cannot be preserved; the extra_data field in the arguments
2554     to pcre_exec() should be used to pass in a tables address if a value
2555     other than the default internal tables were used at compile time.
2557     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2558     now diagnosed as an error. Previously, most of the time, a negative number
2559     would have been treated as zero, but if in addition "ovector" was passed as
2560     NULL, a crash could occur.
2562     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2563     new versions from the libtool 1.5 distribution (the last one is a copy of
2564     a file called libtool.m4). This seems to have fixed the need to patch
2565     "configure" to support Darwin 1.3 (which I used to do). However, I still
2566     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2567     workstation).
2569     24. Changed the PCRE licence to be the more standard "BSD" licence.
2572 nigel 73 Version 4.5 01-Dec-03
2573     ---------------------
2575     1. There has been some re-arrangement of the code for the match() function so
2576     that it can be compiled in a version that does not call itself recursively.
2577     Instead, it keeps those local variables that need separate instances for
2578     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2579     needs to "recurse". Keeping track of where control must go is done by means
2580     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2581     hide most of the details from the main code, and operates only if
2582     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2583     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2584     operating.
2586     To make it easier for callers to provide specially tailored get/free
2587     functions for this usage, two new functions, pcre_stack_malloc, and
2588     pcre_stack_free, are used. They are always called in strict stacking order,
2589     and the size of block requested is always the same.
2591     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2592     PCRE has been compiled to use the stack or the heap for recursion. The
2593     -C option of pcretest uses this to show which version is compiled.
2595     A new data escape \S, is added to pcretest; it causes the amounts of store
2596     obtained and freed by both kinds of malloc/free at match time to be added
2597     to the output.
2599     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2600     what's available on my current Linux desktop machine.
2602     3. When matching a UTF-8 string, the test for a valid string at the start has
2603     been extended. If start_offset is not zero, PCRE now checks that it points
2604     to a byte that is the start of a UTF-8 character. If not, it returns
2605     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2606     this is necessary because there may be backward assertions in the pattern.
2607     When matching the same subject several times, it may save resources to use
2608     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2610     4. The code for checking the validity of UTF-8 strings has been tightened so
2611     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2612     containing "overlong sequences".
2614     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2615     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2616     should have been "&", but it just so happened that all the cases this let
2617     through by mistake were picked up later in the function.
2619     6. I had used a variable called "isblank" - this is a C99 function, causing
2620     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2622     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2623     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2624     so the version is shown; (c) stop "make test" echoing "./RunTest".
2626     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2628     9. The prototype for memmove() for systems that don't have it was using
2629     size_t, but the inclusion of the header that defines size_t was later. I've
2630     moved the #includes for the C headers earlier to avoid this.
2632     10. Added some adjustments to the code to make it easier to compiler on certain
2633     special systems:
2635     (a) Some "const" qualifiers were missing.
2636     (b) Added the macro EXPORT before all exported functions; by default this
2637     is defined to be empty.
2638     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2639     that it reads its output file name as an argument instead of writing
2640     to the standard output and assuming this can be redirected.
2642     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2643     class containing characters with values greater than 255, PCRE compilation
2644     went into a loop.
2646     12. A recursive reference to a subpattern that was within another subpattern
2647     that had a minimum quantifier of zero caused PCRE to crash. For example,
2648     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2649     recursion. If the recursively-called subpattern itself had a zero repeat,
2650     that was OK.
2652     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2653     buffer into which it was copied (for escape processing) was still set at
2654     1024, so long lines caused crashes.
2656     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2657     "internal error: code overflow...". This applied to any character class
2658     that was followed by a possessive quantifier.
2660     15. Modified the Makefile to add libpcre.la as a prerequisite for
2661     libpcreposix.la because I was told this is needed for a parallel build to
2662     work.
2664     16. If a pattern that contained .* following optional items at the start was
2665     studied, the wrong optimizing data was generated, leading to matching
2666     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2667     matching string must start with a or b or c. The correct conclusion for
2668     this pattern is that a match can start with any character.
2671 nigel 71 Version 4.4 13-Aug-03
2672     ---------------------
2674     1. In UTF-8 mode, a character class containing characters with values between
2675     127 and 255 was not handled correctly if the compiled pattern was studied.
2676     In fixing this, I have also improved the studying algorithm for such
2677     classes (slightly).
2679     2. Three internal functions had redundant arguments passed to them. Removal
2680     might give a very teeny performance improvement.
2682     3. Documentation bug: the value of the capture_top field in a callout is *one
2683     more than* the number of the hightest numbered captured substring.
2685     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2686     in incorrectly linking with a previously installed version. They now link
2687     explicitly with libpcre.la.
2689     5. configure.in no longer needs to recognize Cygwin specially.
2691     6. A problem in pcre.in for Windows platforms is fixed.
2693     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2694     pcretest, it used to include the size of the study block as part of its
2695     output. Unfortunately, the structure contains a field that has a different
2696     size on different hardware architectures. This meant that the tests that
2697     showed this size failed. As the block is currently always of a fixed size,
2698     this information isn't actually particularly useful in pcretest output, so
2699     I have just removed it.
2701     8. Three pre-processor statements accidentally did not start in column 1.
2702     Sadly, there are *still* compilers around that complain, even though
2703     standard C has not required this for well over a decade. Sigh.
2705     9. In pcretest, the code for checking callouts passed small integers in the
2706     callout_data field, which is a void * field. However, some picky compilers
2707     complained about the casts involved for this on 64-bit systems. Now
2708     pcretest passes the address of the small integer instead, which should get
2709     rid of the warnings.
2711     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2712     both compile and run time, and gives an error if an invalid UTF-8 sequence
2713     is found. There is a option for disabling this check in cases where the
2714     string is known to be correct and/or the maximum performance is wanted.
2716     11. In response to a bug report, I changed one line in Makefile.in from
2718     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2719     to
2720     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2722     to look similar to other lines, but I have no way of telling whether this
2723     is the right thing to do, as I do not use Windows. No doubt I'll get told
2724     if it's wrong...
2727 nigel 69 Version 4.3 21-May-03
2728     ---------------------
2730     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2731     Makefile.
2733     2. Some refactoring to improve the quality of the code:
2735     (i) The utf8_table... variables are now declared "const".
2737     (ii) The code for \cx, which used the "case flipping" table to upper case
2738     lower case letters, now just substracts 32. This is ASCII-specific,
2739     but the whole concept of \cx is ASCII-specific, so it seems
2740     reasonable.
2742     (iii) PCRE was using its character types table to recognize decimal and
2743     hexadecimal digits in the pattern. This is silly, because it handles
2744     only 0-9, a-f, and A-F, but the character types table is locale-
2745     specific, which means strange things might happen. A private
2746     table is now used for this - though it costs 256 bytes, a table is
2747     much faster than multiple explicit tests. Of course, the standard
2748     character types table is still used for matching digits in subject
2749     strings against \d.
2751     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2752     ending in _t are). So I've renamed it as ESC_tee.
2754     3. The first argument for regexec() in the POSIX wrapper should have been
2755     defined as "const".
2757     4. Changed pcretest to use malloc() for its buffers so that they can be
2758     Electric Fenced for debugging.
2760     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2761     to read one or more bytes before the start of the subject string. Often this
2762     had no effect on PCRE's behaviour, but in some circumstances it could
2763     provoke a segmentation fault.
2765     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2766     to try to read one or more bytes before the start of the subject string.
2768     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2769     UTF-8 support could misbehave in various ways if the subject string
2770     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2771     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2772     back over UTF-8 characters.)
2775 nigel 67 Version 4.2 14-Apr-03
2776     ---------------------
2778     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2780     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2781     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2782     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2783     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2784     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2785     and BUILD_EXEEXT
2786     Note: automatic setting of the BUILD variables is not yet working
2787     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2788     compile-time but not at link-time
2789     [LINK]: use for linking executables only
2790     make different versions for Windows and non-Windows
2791     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2792     libraries
2793     [LINK_FOR_BUILD]: new variable
2794     [OBJEXT]: use throughout
2795     [EXEEXT]: use throughout
2796     <winshared>: new target
2797     <wininstall>: new target
2798     <dftables.o>: use native compiler
2799     <dftables>: use native linker
2800     <install>: handle Windows platform correctly
2801     <clean>: ditto
2802     <check>: ditto
2803     copy DLL to top builddir before testing
2805     As part of these changes, -no-undefined was removed again. This was reported
2806     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2807     in any case.
2809     3. Some tidies to get rid of compiler warnings:
2811     . In the match_data structure, match_limit was an unsigned long int, whereas
2812     match_call_count was an int. I've made them both unsigned long ints.
2814     . In pcretest the fact that a const uschar * doesn't automatically cast to
2815     a void * provoked a warning.
2817     . Turning on some more compiler warnings threw up some "shadow" variables
2818     and a few more missing casts.
2820     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2821     option, a class that contained a single character with a value between 128
2822     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2824     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2825     option, a class that contained several characters, but with at least one
2826     whose value was between 128 and 255 caused PCRE to crash.
2829 nigel 65 Version 4.1 12-Mar-03
2830     ---------------------
2831 nigel 63
2832 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2833     needed, and a string in dftables.c that was longer than standard compilers are
2834     required to support.
2836     2. Compiling with Sun's compiler found a few more places where the code could
2837     be tidied up in order to avoid warnings.
2839     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2840     first of these names is deprecated in the latest Autoconf in favour of the name
2841     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2842     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2843     analogy I have changed it to CFLAGS_FOR_BUILD.
2845     4. Added -no-undefined to the linking command in the Makefile, because this is
2846     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2847     linking step for the pcreposix library.
2849     5. PCRE was failing to diagnose the case of two named groups with the same
2850     name.
2852     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2853     literal character that is needed in the subject for a match, and scans along to
2854     ensure that it is present before embarking on the full matching process. This
2855     saves time in cases of nested unlimited repeats that are never going to match.
2856     Problem: the scan can take a lot of time if the subject is very long (e.g.
2857     megabytes), thus penalizing straightforward matches. It is now done only if the
2858     amount of subject to be scanned is less than 1000 bytes.
2860     7. A lesser problem with the same optimization is that it was recording the
2861     first character of an anchored pattern as "needed", thus provoking a search
2862     right along the subject, even when the first match of the pattern was going to
2863     fail. The "needed" character is now not set for anchored patterns, unless it
2864     follows something in the pattern that is of non-fixed length. Thus, it still
2865     fulfils its original purpose of finding quick non-matches in cases of nested
2866     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2869     Version 4.0 17-Feb-03
2870     ---------------------
2872 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2873     extended to the end of string, PCRE compiled incorrect data. This could lead to
2874     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2876     2. Moved to autoconf 2.53 and libtool 1.4.2.
2878     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2879     the special perltest8 script is no longer needed - all the tests can be run
2880     from a single perltest script.
2882     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2883     by \s. It has now been removed in PCRE. This means it isn't recognized as
2884     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2885     class [:space:] *does* include VT, thereby creating a mess.
2887     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2888     space and tab.
2890     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2891     its new features into the main test script, reducing the number of scripts.
2893     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2894     were backward compatible, and made the (?i) apply to the whole pattern, as if
2895     /i were given. Now it behaves more logically, and applies the option setting
2896     only to what follows. PCRE has been changed to follow suit. However, if it
2897     finds options settings right at the start of the pattern, it extracts them into
2898     the global options, as before. Thus, they show up in the info data.
2900     8. Added support for the \Q...\E escape sequence. Characters in between are
2901     treated as literals. This is slightly different from Perl in that $ and @ are
2902     also handled as literals inside the quotes. In Perl, they will cause variable
2903     interpolation. Note the following examples:
2905     Pattern PCRE matches Perl matches
2907     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2908     \Qabc\$xyz\E abc\$xyz abc\$xyz
2909     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2911     For compatibility with Perl, \Q...\E sequences are recognized inside character
2912     classes as well as outside them.
2914     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2915     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2916     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2917     signed/unsigned warnings.
2919     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2920     option for pcretest, so I've replaced it by a simple function that does just
2921     that job.
2923     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2924     "pcregrep -".
2926     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2927     Java package. This provides some syntactic sugar for simple cases of what my
2928     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2929     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2930     item, you can use this simplified notation. Note that only makes sense with
2931     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2932     greediness, whatever the setting of the PCRE_UNGREEDY option.
2934     13. A change of greediness default within a pattern was not taking effect at
2935     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2936     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2937     was abstracted outside.
2939     14. PCRE now supports the \G assertion. It is true when the current matching
2940     position is at the start point of the match. This differs from \A when the
2941     starting offset is non-zero. Used with the /g option of pcretest (or similar
2942     code), it works in the same way as it does for Perl's /g option. If all
2943     alternatives of a regex begin with \G, the expression is anchored to the start
2944     match position, and the "anchored" flag is set in the compiled expression.
2946     15. Some bugs concerning the handling of certain option changes within patterns
2947     have been fixed. These applied to options other than (?ims). For example,
2948     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2949     been the other way round. Some of this was related to change 7 above.
2951     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2952     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2953     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2954     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2956     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2957     mode. Unlike ".", it always matches newline, whatever the setting of
2958     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2959     assertions. Perl allows it, but it doesn't (in general) work because it can't
2960     calculate the length of the lookbehind. At least, that's the case for Perl
2961     5.8.0 - I've been told they are going to document that it doesn't work in
2962     future.
2964     18. Added an error diagnosis for escapes that PCRE does not support: these are
2965     \L, \l, \N, \P, \p, \U, \u, and \X.
2967     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2968     reading past the end of the pattern in cases such as /[abcd/.
2970     20. PCRE was getting more memory than necessary for patterns with classes that
2971     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2973     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2974     compiling PCRE for use with Virtual Pascal.
2976     22. Small fix to the Makefile to make it work properly if the build is done
2977     outside the source tree.
2979     23. Added a new extension: a condition to go with recursion. If a conditional
2980     subpattern starts with (?(R) the "true" branch is used if recursion has
2981     happened, whereas the "false" branch is used only at the top level.
2983     24. When there was a very long string of literal characters (over 255 bytes
2984     without UTF support, over 250 bytes with UTF support), the computation of how
2985     much memory was required could be incorrect, leading to segfaults or other
2986     strange effects.
2988     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2989     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2990     there was a subsequent back reference to those brackets. This meant that, for
2991     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2992     possible to check for precisely this case. All we can do is abandon the
2993     optimization if .* occurs inside capturing brackets when there are any back
2994     references whatsoever. (See below for a better fix that came later.)
2996     26. The handling of the optimization for finding the first character of a
2997     non-anchored pattern, and for finding a character that is required later in the
2998     match were failing in some cases. This didn't break the matching; it just
2999     failed to optimize when it could. The way this is done has been re-implemented.
3001     27. Fixed typo in error message for invalid (?R item (it said "(?p").
3003     28. Added a new feature that provides some of the functionality that Perl
3004     provides with (?{...}). The facility is termed a "callout". The way it is done
3005     in PCRE is for the caller to provide an optional function, by setting
3006     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3007     global variable. By default it is unset, which disables all calling out. To get
3008     the function called, the regex must include (?C) at appropriate points. This
3009     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3010     This provides a means of identifying different callout points. When PCRE
3011     reaches such a point in the regex, if pcre_callout has been set, the external
3012     function is called. It is provided with data in a structure called
3013     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3014     matching continues; if it returns a non-zero value, the match at the current
3015     point fails. However, backtracking will occur if possible. [This was changed
3016     later and other features added - see item 49 below.]
3018     29. pcretest is upgraded to test the callout functionality. It provides a
3019     callout function that displays information. By default, it shows the start of
3020     the match and the current position in the text. There are some new data escapes
3021     to vary what happens:
3023     \C+ in addition, show current contents of captured substrings
3024     \C- do not supply a callout function
3025     \C!n return 1 when callout number n is reached
3026     \C!n!m return 1 when callout number n is reached for the mth time
3028     30. If pcregrep was called with the -l option and just a single file name, it
3029     output "<stdin>" if a match was found, instead of the file name.
3031     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3032     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3033     pcre_exec(). This saves a malloc/free per call. The default value of
3034     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3035     when configuring.
3037     32. The default maximum size of a compiled pattern is 64K. There have been a
3038     few cases of people hitting this limit. The code now uses macros to handle the
3039     storing of links as offsets within the compiled pattern. It defaults to 2-byte
3040     links, but this can be changed to 3 or 4 bytes by --with-link-size when
3041     configuring. Tests 2 and 5 work only with 2-byte links because they output
3042     debugging information about compiled patterns.
3044     33. Internal code re-arrangements:
3046     (a) Moved the debugging function for printing out a compiled regex into
3047     its own source file (printint.c) and used #include to pull it into
3048     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3049     separate copies.
3051     (b) Defined the list of op-code names for debugging as a macro in
3052     internal.h so that it is next to the definition of the opcodes.
3054     (c) Defined a table of op-code lengths for simpler skipping along compiled
3055     code. This is again a macro in internal.h so that it is next to the
3056     definition of the opcodes.
3058     34. Added support for recursive calls to individual subpatterns, along the
3059     lines of Robin Houston's patch (but implemented somewhat differently).
3061     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3062     allow it to read and process whole directories in Win32. This code was
3063     contributed by Lionel Fourquaux; it has not been tested by me.
3065     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3066     used to name a group. Names consist of alphanumerics and underscores, and must
3067     be unique. Back references use the syntax (?P=name) and recursive calls use
3068     (?P>name) which is a PCRE extension to the Python extension. Groups still have
3069     numbers. The function pcre_fullinfo() can be used after compilation to extract
3070     a name/number map. There are three relevant calls:
3072     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3073     PCRE_INFO_NAMECOUNT yields the number of entries
3074     PCRE_INFO_NAMETABLE yields a pointer to the map.
3076     The map is a vector of fixed-size entries. The size of each entry depends on
3077     the length of the longest name used. The first two bytes of each entry are the
3078     group number, most significant byte first. There follows the corresponding
3079     name, zero terminated. The names are in alphabetical order.
3081     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3082     case instead of 255. Making it the same both with and without UTF-8 support
3083     means that the same test output works with both.
3085     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3086     calling malloc() with a zero argument.
3088     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3089     optimization. I've improved things by keeping a bitmap of backreferences with
3090     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3091     fact referenced, the optimization can be applied. It is unlikely that a
3092     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3093     the match to follow \n) will appear inside brackets with a number greater than
3094     31, but if it does, any back reference > 31 suppresses the optimization.
3096     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3097     of disabling numbered capturing parentheses. Any opening parenthesis that is
3098     not followed by ? behaves as if it were followed by ?: but named parentheses
3099     can still be used for capturing (and they will acquire numbers in the usual
3100     way).
3102     41. Redesigned the return codes from the match() function into yes/no/error so
3103     that errors can be passed back from deep inside the nested calls. A malloc
3104     failure while inside a recursive subpattern call now causes the
3105     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3107     42. It is now possible to set a limit on the number of times the match()
3108     function is called in a call to pcre_exec(). This facility makes it possible to
3109     limit the amount of recursion and backtracking, though not in a directly
3110     obvious way, because the match() function is used in a number of different
3111     circumstances. The count starts from zero for each position in the subject
3112     string (for non-anchored patterns). The default limit is, for compatibility, a
3113     large number, namely 10 000 000. You can change this in two ways:
3115     (a) When configuring PCRE before making, you can use --with-match-limit=n
3116     to set a default value for the compiled library.
3118     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3119     a different value is set. See 45 below.
3121     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3123     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3124     of things that can be changed at compile time. The first argument specifies
3125     what is wanted and the second points to where the information is to be placed.
3126     The current list of available information is:
3130     The output is an integer that is set to one if UTF-8 support is available;
3131     otherwise it is set to zero.
3135     The output is an integer that it set to the value of the code that is used for
3136     newline. It is either LF (10) or CR (13).
3140     The output is an integer that contains the number of bytes used for internal
3141     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3145     The output is an integer that contains the threshold above which the POSIX
3146     interface uses malloc() for output vectors. See item 31 above.
3150     The output is an unsigned integer that contains the default limit of the number
3151     of match() calls in a pcre_exec() execution. See 42 above.
3153     44. pcretest has been upgraded by the addition of the -C option. This causes it
3154     to extract all the available output from the new pcre_config() function, and to
3155     output it. The program then exits immediately.
3157     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3158     order to support additional features. One way would have been to define
3159     pcre_exec2() (for example) with extra arguments, but this would not have been
3160     extensible, and would also have required all calls to the original function to
3161     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3162     is used for passing in "extra" data from pcre_study().
3164     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3165     contains the following fields:
3167     flags a bitmap indicating which of the following fields are set
3168     study_data opaque data from pcre_study()
3169     match_limit a way of specifying a limit on match() calls for a specific
3170     call to pcre_exec()
3171     callout_data data for callouts (see 49 below)
3173     The flag bits are also defined in pcre.h, and are
3179     The pcre_study() function now returns one of these new pcre_extra blocks, with
3180     the actual study data pointed to by the study_data field, and the
3181     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3182     before. That is, this change is entirely upwards-compatible and requires no
3183     change to existing code.
3185     If you want to pass in additional data to pcre_exec(), you can either place it
3186     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3187     block.
3189     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3190     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3191     times with different match limits, until it finds the minimum value needed for
3192     pcre_exec() to complete. The value is then output. This can be instructive; for
3193     most simple matches the number is quite small, but for pathological cases it
3194     gets very large very quickly.
3196     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3197     returns the size of the data block pointed to by the study_data field in a
3198     pcre_extra block, that is, the value that was passed as the argument to
3199     pcre_malloc() when PCRE was getting memory in which to place the information
3200     created by pcre_study(). The fourth argument should point to a size_t variable.
3201     pcretest has been extended so that this information is shown after a successful
3202     pcre_study() call when information about the compiled regex is being displayed.
3204     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3205     because what follows is always an absolute path. (Later: it turns out that this
3206     is more than cosmetic for MinGW, because it doesn't like empty path
3207     components.)
3209     49. Some changes have been made to the callout feature (see 28 above):
3211     (i) A callout function now has three choices for what it returns:
3213     0 => success, carry on matching
3214     > 0 => failure at this point, but backtrack if possible
3215     < 0 => serious error, return this value from pcre_exec()
3217     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3218     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3219     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3220     use by callout functions. It will never be used by PCRE itself.
3222     (ii) The pcre_extra structure (see 45 above) has a void * field called
3223     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3224     pcre_callout_block structure has a field of the same name. The contents of
3225     the field passed in the pcre_extra structure are passed to the callout
3226     function in the corresponding field in the callout block. This makes it
3227     easier to use the same callout-containing regex from multiple threads. For
3228     testing, the pcretest program has a new data escape
3230     \C*n pass the number n (may be negative) as callout_data
3232     If the callout function in pcretest receives a non-zero value as
3233     callout_data, it returns that value.
3235     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3236     there were some redundant $(CFLAGS) in commands that are now specified as
3237     $(LINK), which already includes $(CFLAGS).
3239     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3240     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3241     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3242     one-byte characters throughout. Note that case-insensitive matching applies
3243     only to characters whose values are less than 256. PCRE doesn't support the
3244     notion of cases for higher-valued characters.
3246     (i) A character class whose characters are all within 0-255 is handled as
3247     a bit map, and the map is inverted for negative classes. Previously, a
3248     character > 255 always failed to match such a class; however it should
3249     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3251     (ii) A negated character class with a single character < 255 is coded as
3252     "not this character" (OP_NOT). This wasn't working properly when the test
3253     character was multibyte, either singly or repeated.
3255     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3256     mode, for example: \x{100}{2,3}.
3258     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3259     singly or repeated) now correctly test multibyte characters. However,
3260     PCRE doesn't recognize any characters with values greater than 255 as
3261     digits, spaces, or word characters. Such characters always match \D, \S,
3262     and \W, and never match \d, \s, or \w.
3264     (v) Classes may now contain characters and character ranges with values
3265     greater than 255. For example: [ab\x{100}-\x{400}].
3267     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3268     PCRE in UTF-8 mode.
3270     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3271     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3272     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3273     value.)
3275     53. The single man page has become too large. I have therefore split it up into
3276     a number of separate man pages. These also give rise to individual HTML pages;
3277     these are now put in a separate directory, and there is an index.html page that
3278     lists them all. Some hyperlinking between the pages has been installed.
3280     54. Added convenience functions for handling named capturing parentheses.
3282     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3283     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3284     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3285     are faulted.
3287     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3288     calling configure. These values are used when compiling the dftables.c program
3289     which is run to generate the source of the default character tables. They
3290     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3291     you will need to set these values.
3293     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3296     Version 3.9 02-Jan-02
3297 nigel 61 ---------------------
3299     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3301     2. If --disable-static was given, the building process failed when trying to
3302     build pcretest and pcregrep. (For some reason it was using libtool to compile
3303     them, which is not right, as they aren't part of the library.)
3306 nigel 59 Version 3.8 18-Dec-01
3307     ---------------------
3309     1. The experimental UTF-8 code was completely screwed up. It was packing the
3310     bytes in the wrong order. How dumb can you get?
3313 nigel 57 Version 3.7 29-Oct-01
3314     ---------------------
3316     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3317     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3318     this didn't happen under Solaris 8, where I normally test things.
3320 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3321     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3322     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3323     this fix an hour or so after the initial 3.7 release.)
3324 nigel 57
3325 nigel 59
3326 nigel 55 Version 3.6 23-Oct-01
3327     ---------------------
3329     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3330     offsets passed as NULL with zero offset count.
3332     2. The config.guess and config.sub files had not been updated when I moved to
3333     the latest autoconf.
3336 nigel 53 Version 3.5 15-Aug-01
3337     ---------------------
3338 nigel 5
3339 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3340     had been forgotten.
3342     2. By using declared but undefined structures, we can avoid using "void"
3343     definitions in pcre.h while keeping the internal definitions of the structures
3344     private.
3346     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3347     user point of view, this means that both static and shared libraries are built
3348     by default, but this can be individually controlled. More of the work of
3349     handling this static/shared cases is now inside libtool instead of PCRE's make
3350     file.
3352     4. The pcretest utility is now installed along with pcregrep because it is
3353     useful for users (to test regexs) and by doing this, it automatically gets
3354     relinked by libtool. The documentation has been turned into a man page, so
3355     there are now .1, .txt, and .html versions in /doc.
3357     5. Upgrades to pcregrep:
3358     (i) Added long-form option names like gnu grep.
3359     (ii) Added --help to list all options with an explanatory phrase.
3360     (iii) Added -r, --recursive to recurse into sub-directories.
3361     (iv) Added -f, --file to read patterns from a file.
3363     6. pcre_exec() was referring to its "code" argument before testing that
3364     argument for NULL (and giving an error if it was NULL).
3366     7. Upgraded Makefile.in to allow for compiling in a different directory from
3367     the source directory.
3369     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3370     options bits, the pointer it was passed was to an int instead of to an unsigned
3371     long int. This mattered only on 64-bit systems.
3373     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3374     generated) instead of pcre.in, which it its source. Also made the same change
3375     in several of the .c files.
3377     10. A new release of gcc defines printf() as a macro, which broke pcretest
3378     because it had an ifdef in the middle of a string argument for printf(). Fixed
3379     by using separate calls to printf().
3381     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3382     script, to force use of CR or LF instead of \n in the source. On non-Unix
3383     systems, the value can be set in config.h.
3385     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3386     absolute limit. Changed the text of the error message to make this clear, and
3387     likewise updated the man page.
3389     13. The limit of 99 on the number of capturing subpatterns has been removed.
3390     The new limit is 65535, which I hope will not be a "real" limit.
3393 nigel 51 Version 3.4 22-Aug-00
3394     ---------------------
3396     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3398     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3401 nigel 49 Version 3.3 01-Aug-00
3402     ---------------------
3404     1. If an octal character was given, but the value was greater than \377, it
3405     was not getting masked to the least significant bits, as documented. This could
3406     lead to crashes in some systems.
3408     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3409     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3411     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3412     These just pass their arguments on to (pcre_free)(), but they are provided
3413     because some uses of PCRE bind it to non-C systems that can call its functions,
3414     but cannot call free() or pcre_free() directly.
3416     4. Add "make test" as a synonym for "make check". Corrected some comments in
3417     the Makefile.
3419     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3420     Makefile.
3422     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3423     command called pgrep for grepping around the active processes.
3425     7. Added the beginnings of support for UTF-8 character strings.
3427     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3428     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3429     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3430     out for the ar command.)
3433 nigel 47 Version 3.2 12-May-00
3434     ---------------------
3436     This is purely a bug fixing release.
3438     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3439     of ZA. This was just one example of several cases that could provoke this bug,
3440     which was introduced by change 9 of version 2.00. The code for breaking
3441     infinite loops after an iteration that matches an empty string was't working
3442     correctly.
3444     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3445     when matched against abbab (for example). After matching an empty string, it
3446     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3447     caused it to match further down the string than it should.
3449     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3450     was there because it doesn't seem to be needed, and it causes trouble on some
3451     systems, as it is not a Standard C header. It has been removed.
3453     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3454     were reported on the Macintosh. The changes were from
3456     while ((c = *(++ptr)) != 0 && c != '\n');
3457     to
3458     while ((c = *(++ptr)) != 0 && c != '\n') ;
3460     Totally extraordinary, but if that's what it takes...
3462     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3463     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3464     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3465     assumes the way PCRE uses memmove() (always moving upwards).
3467     6. PCRE is being used in one environment where strchr() is not available. There
3468     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3469     faster code anyway.
3472 nigel 45 Version 3.1 09-Feb-00
3473     ---------------------
3475     The only change in this release is the fixing of some bugs in Makefile.in for
3476     the "install" target:
3478     (1) It was failing to install pcreposix.h.
3480     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3483 nigel 43 Version 3.0 01-Feb-00
3484     ---------------------
3485 nigel 41
3486     1. Add support for the /+ modifier to perltest (to output $` like it does in
3487     pcretest).
3489     2. Add support for the /g modifier to perltest.
3491     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3492     matches null strings.
3494     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3495     pattern. Perl treats empty patterns specially - it reuses the most recent
3496     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3497     effect.
3499     5. The POSIX interface was broken in that it was just handing over the POSIX
3500     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3501     required a bigger vector, with some working space on the end. This means that
3502     the POSIX wrapper now has to get and free some memory, and copy the results.
3504 nigel 43 6. Added some simple autoconf support, placing the test data and the
3505     documentation in separate directories, re-organizing some of the
3506     information files, and making it build pcre-config (a GNU standard). Also added
3507     libtool support for building PCRE as a shared library, which is now the
3508     default.
3509 nigel 41
3510 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3511     09 are not valid octal constants. Single digits will be used for minor values
3512     less than 10.
3514     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3515     existing programs that set these in the POSIX interface can use PCRE without
3516     modification.
3518     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3519     return all that pcre_info() returns, plus additional data. The pcre_info()
3520     function is retained for compatibility, but is considered to be obsolete.
3522     10. Added experimental recursion feature (?R) to handle one common case that
3523     Perl 5.6 will be able to do with (?p{...}).
3525     11. Added support for POSIX character classes like [:alpha:], which Perl is
3526     adopting.
3529 nigel 39 Version 2.08 31-Aug-99
3530     ----------------------
3532     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3533     trying to match at the startoffset position, but instead was moving forward to
3534     the next newline as if a previous match had failed.
3536     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3537     and could get into a loop if a null string was matched other than at the start
3538     of the subject.
3540     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3541     be distinguished at compile time, and for completeness also added PCRE_DATE.
3543     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3544     in GnuWin32 environments.
3547 nigel 37 Version 2.07 29-Jul-99
3548     ----------------------
3550     1. The documentation is now supplied in plain text form and HTML as well as in
3551     the form of man page sources.
3553     2. C++ compilers don't like assigning (void *) values to other pointer types.
3554     In particular this affects malloc(). Although there is no problem in Standard
3555     C, I've put in casts to keep C++ compilers happy.
3557     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3558     should be (const char *).
3560     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3561     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3562     However, I haven't made this a standard facility. The documentation doesn't
3563     mention it, and the Makefile doesn't support it.
3565     5. The Makefile now contains an "install" target, with editable destinations at
3566     the top of the file. The pcretest program is not installed.
3568     6. pgrep -V now gives the PCRE version number and date.
3570     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3571     causing the entire string to be ignored, instead of just the last character.
3573     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3574     non-matching string, it can take a very, very long time, even for strings of
3575     quite modest length, because of the nested recursion. PCRE now does better in
3576     some of these cases. It does this by remembering the last required literal
3577     character in the pattern, and pre-searching the subject to ensure it is present
3578     before running the real match. In other words, it applies a heuristic to detect
3579     some types of certain failure quickly, and in the above example, if presented
3580     with a string that has no trailing " it gives "no match" very quickly.
3582     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3583     other alternatives are tried instead.
3586 nigel 35 Version 2.06 09-Jun-99
3587     ----------------------
3589     1. Change pcretest's output for amount of store used to show just the code
3590     space, because the remainder (the data block) varies in size between 32-bit and
3591     64-bit systems.
3593     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3594     start matching at. This allows lookbehinds to work when searching for multiple
3595     occurrences in a string.
3597     3. Added additional options to pcretest for testing multiple occurrences:
3599     /+ outputs the rest of the string that follows a match
3600     /g loops for multiple occurrences, using the new startoffset argument
3601     /G loops for multiple occurrences by passing an incremented pointer
3603     4. PCRE wasn't doing the "first character" optimization for patterns starting
3604     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3605     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3606     the letter 'x'. On long subject strings, this gives a significant speed-up.
3609 nigel 33 Version 2.05 21-Apr-99
3610     ----------------------
3612     1. Changed the type of magic_number from int to long int so that it works
3613     properly on 16-bit systems.
3615     2. Fixed a bug which caused patterns starting with .* not to work correctly
3616     when the subject string contained newline characters. PCRE was assuming
3617     anchoring for such patterns in all cases, which is not correct because .* will
3618     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3619     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3620     must be retried after every newline in the subject.
3623 nigel 31 Version 2.04 18-Feb-99
3624     ----------------------
3626     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3627     computation of the store needed to hold the pattern was incorrect (too large).
3628     If such patterns were nested a few deep, this could multiply and become a real
3629     problem.
3631     2. Added /M option to pcretest to show the memory requirement of a specific
3632     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3634     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3635     compiled in such a way that the backtracking after subsequent failure was
3636     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3637     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3640 nigel 29 Version 2.03 02-Feb-99
3641     ----------------------
3643     1. Fixed typo and small mistake in man page.
3645 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3646     LICENCE file containing the conditions.
3647 nigel 29
3648     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3649     Perl, that is the internal \ allows the delimiter to be included in the
3650     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3651     the final delimiter, add \ to the end of the pattern (to test the error).
3653     4. Added the convenience functions for extracting substrings after a successful
3654     match. Updated pcretest to make it able to test these functions.
3657 nigel 27 Version 2.02 14-Jan-99
3658     ----------------------
3660     1. Initialized the working variables associated with each extraction so that
3661     their saving and restoring doesn't refer to uninitialized store.
3663     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3664     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3665     fix the problem.
3667     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3668     calls, and wasn't printing the correct value for compiling calls. Increased the
3669     default value of LOOPREPEAT, and the number of significant figures in the
3670     times.
3672     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3674     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3675     a building problem on Windows NT with a FAT file system.
3678 nigel 25 Version 2.01 21-Oct-98
3679     ----------------------
3681     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3682     to character tables built by pcre_maketables() in the current locale. If NULL
3683     is passed, the default tables are used.
3686 nigel 23 Version 2.00 24-Sep-98
3687 nigel 21 ----------------------
3689 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3690     it any more.
3692     2. Allow quantification of (?>) groups, and make it work correctly.
3694     3. The first character computation wasn't working for (?>) groups.
3696     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3697     end of the subject) and add 5.005's \z, which really does match only at the
3698     very end of the subject.
3700     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3702     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3703     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3704     localized options. All options to pcre_study() were also removed.
3706     7. Add other new features from 5.005:
3708     $(?<= positive lookbehind
3709     $(?<! negative lookbehind
3710     (?imsx-imsx) added the unsetting capability
3711     such a setting is global if at outer level; local otherwise
3712     (?imsx-imsx:) non-capturing groups with option setting
3713     (?(cond)re|re) conditional pattern matching
3715     A backreference to itself in a repeated group matches the previous
3716     captured string.
3718     8. General tidying up of studying (both automatic and via "study")
3719     consequential on the addition of new assertions.
3721     9. As in 5.005, unlimited repeated groups that could match an empty substring
3722     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3723     runtime if any iteration does actually match an empty substring.
3725     10. Include the RunTest script in the distribution.
3727     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3728     discrepancies, some of which were old and were also with respect to 5.004. They
3729     have now been fixed.
3732     Version 1.09 28-Apr-98
3733     ----------------------
3735 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3736     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3737     program crashes, or just wrong answers. This did not apply to negated classes
3738     containing more than one character, or to minima other than one.
3741 nigel 19 Version 1.08 27-Mar-98
3742     ----------------------
3744     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3746     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3747     latter must appear before anything that relies on it in the pattern.
3750 nigel 17 Version 1.07 16-Feb-98
3751     ----------------------
3753     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3754     repeat of a potentially empty string).
3757 nigel 15 Version 1.06 23-Jan-98
3758     ----------------------
3760     1. Added Markus Oberhumer's little patches for C++.
3762     2. Literal strings longer than 255 characters were broken.
3765 nigel 13 Version 1.05 23-Dec-97
3766     ----------------------
3768     1. Negated character classes containing more than one character were failing if
3769     PCRE_CASELESS was set at run time.
3772 nigel 11 Version 1.04 19-Dec-97
3773     ----------------------
3775     1. Corrected the man page, where some "const" qualifiers had been omitted.
3777     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3778     input syntax.
3780     3. Fixed memory leak which occurred when a regex with back references was
3781     matched with an offsets vector that wasn't big enough. The temporary memory
3782     that is used in this case wasn't being freed if the match failed.
3784     4. Tidied pcretest to ensure it frees memory that it gets.
3786     5. Temporary memory was being obtained in the case where the passed offsets
3787     vector was exactly big enough.
3789     6. Corrected definition of offsetof() from change 5 below.
3791     7. I had screwed up change 6 below and broken the rules for the use of
3792     setjmp(). Now fixed.
3795 nigel 9