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Revision 528 - (hide annotations) (download)
Sat May 29 16:40:22 2010 UTC (4 years, 10 months ago) by ph10
File size: 187681 byte(s)
Add knowledge of \R to auto-possessify feature.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 513 Version 8.10 03 May-2010
5 ph10 510 ------------------------
7 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8 ph10 510 THEN.
10 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
11 ph10 510
12 ph10 513 3. Inside a character class, \B is treated as a literal by default, but
13     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14     causes the error). The code is unchanged, but I tidied the documentation.
16     4. Inside a character class, PCRE always treated \R and \X as literals,
17     whereas Perl faults them if its -w option is set. I have changed PCRE so
18     that it faults them when PCRE_EXTRA is set.
19 ph10 514
20     5. Added support for \N, which always matches any character other than
21     newline. (It is the same as "." when PCRE_DOTALL is not set.)
22 ph10 515
23     6. When compiling pcregrep with newer versions of gcc which may have
24     FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25     declared with attribute warn_unused_result" were given. Just casting the
26     result to (void) does not stop the warnings; a more elaborate fudge is
27     needed. I've used a macro to implement this.
28 ph10 516
29     7. Minor change to pcretest.c to avoid a compiler warning.
30 ph10 512
31 ph10 517 8. Added four artifical Unicode properties to help with an option to make
32 ph10 518 \s etc use properties (see next item). The new properties are: Xan
33     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
35     9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36     use Unicode properties. (*UCP) at the start of a pattern can be used to set
37     this option. Modified pcretest to add /W to test this facility. Added
38     REG_UCP to make it available via the POSIX interface.
39 ph10 519
40     10. Added --line-buffered to pcregrep.
41 ph10 513
42 ph10 520 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43     studied, and the match started with a letter with a code point greater than
44     127 whose first byte was different to the first byte of the other case of
45     the letter, the other case of this starting letter was not recognized.
46 ph10 521
47     12. pcreposix.c included pcre.h before including pcre_internal.h. This caused a
48     conflict in the definition of PCRE_EXP_DECL. I have removed the include of
49     pcre.h as pcre_internal.h includes pcre.h itself. (This may be a bit of
50     historical tidying that never got done.)
51 ph10 523
52     13. If a pattern that was studied started with a repeated Unicode property
53     test, for example, \p{Nd}+, there was the theoretical possibility of
54     setting up an incorrect bitmap of starting bytes, but fortunately it could
55     not have actually happened in practice until change 8 above was made (it
56     added property types that matched character-matching opcodes).
57 ph10 524
58     14. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
59     possible starting bytes for non-anchored patterns.
60 ph10 528
61     15. The "auto-possessify" feature of pcre_compile() now recognizes \R.
62 ph10 521
63 ph10 517
64 ph10 520
65 ph10 508 Version 8.02 19-Mar-2010
66 ph10 491 ------------------------
68     1. The Unicode data tables have been updated to Unicode 5.2.0.
70 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
71     configured.
72 ph10 507
73 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
74 ph10 507 original author of that file, following a query about its status.
76     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
77 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
78 ph10 507
79 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
80     quantifier applied to a forward-referencing subroutine call, could compile
81     incorrect code or give the error "internal error: previously-checked
82     referenced subpattern not found".
83 ph10 507
84     6. Both MS Visual Studio and Symbian OS have problems with initializing
85 ph10 497 variables to point to external functions. For these systems, therefore,
86     pcre_malloc etc. are now initialized to local functions that call the
87     relevant global functions.
88 ph10 507
89 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
90     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
91 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
92     the lengths are correct (equal to the number of opcodes).
94     8. Following on from 7, I added a similar kludge to check the length of the
95     eint vector in pcreposix.c.
97     9. Error texts for pcre_compile() are held as one long string to avoid too
98     much relocation at load time. To find a text, the string is searched,
99 ph10 499 counting zeros. There was no check for running off the end of the string,
100     which could happen if a new error number was added without updating the
101 ph10 507 string.
103     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
105 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
106 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
107     \K is "not well defined" if used in an assertion. PCRE now accepts it if
108     the assertion is positive, but not if it is negative.
110 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
111 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
112     implementation of support for (*MARK) will need an extra pointer on the
113 ph10 501 stack; I have reserved it now, so that the stack frame size does not
114     decrease.
115 ph10 507
116     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
117     item in branch that calls a recursion is a subroutine call - as in the
118 ph10 503 second branch in the above example - was incorrectly given the compile-
119     time error "recursive call could loop indefinitely" because pcre_compile()
120 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
122 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
123 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
124 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
125 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
126 ph10 491
127 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
128 ph10 492
129 ph10 507
130 ph10 489 Version 8.01 19-Jan-2010
131     ------------------------
132 ph10 471
133     1. If a pattern contained a conditional subpattern with only one branch (in
134 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
135 ph10 473 computed the wrong minimum data length (which is of course zero for such
136 ph10 489 subpatterns). This could cause incorrect "no match" results.
137 ph10 473
138     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
139 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
140     "internal error: code overflow at offset...". This happened only when
141 ph10 473 the reset was to the original external option setting. (An optimization
142     abstracts leading options settings into an external setting, which was the
143 ph10 472 cause of this.)
144 ph10 471
145 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
146     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
147     assertion pattern did not match (meaning that the assertion was true), it
148     was incorrectly treated as false if the SKIP had been reached during the
149     matching. This also applied to assertions used as conditions.
150 ph10 471
151 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
152     assertion subpattern, including such a pattern used as a condition,
153     unpredictable results occurred, instead of the error return
155 ph10 478
156 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
157     situation when an empty string is matched. It now does the fancy magic
158 ph10 478 stuff that is necessary.
160     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
161 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
162 ph10 478
163 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
164     as part of something else:
165 ph10 478
166     (a) Change DEBUG to PCRE_DEBUG.
168     (b) In pcre_compile(), rename the member of the "branch_chain" structure
169     called "current" as "current_branch", to prevent a collision with the
170 ph10 475 Linux macro when compiled as a kernel module.
171 ph10 478
172     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
173     prevent a collision with the Linux macro when compiled as a kernel
174 ph10 475 module.
175 ph10 478
176 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
177     cast potentially large values to (double). This has been changed to that
178 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
179     instead, thus avoiding the use of floating point arithmetic. (There is no
180     other use of FP in PCRE.) If int64_t is not found, the fallback is to
181     double.
183     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
184 ph10 476 2005 (difference between two addresses compared to an unsigned value).
185 ph10 473
186 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
187     custom one, because of the following reported problem in Windows:
188 ph10 473
189 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
190 ph10 489 under Win32.
191 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
192 ph10 489 therefore missing the function definition.
193 ph10 478 - The compiler thus generates a "C" signature for the test function.
194     - The linker fails to find the "C" function.
195     - PCRE fails to configure if asked to do so against libbz2.
196 ph10 486
197 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
198     messages were output:
199 ph10 478
200 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
201     rerunning libtoolize, to keep the correct libtool macros in-tree.
202     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
203 ph10 486
204 ph10 479 I have done both of these things.
205 ph10 486
206 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
207 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
208     runaway infinite recursion. I updated the discussion in the pcrestack man
209     page.
211     13. Now that we have gone to the x.xx style of version numbers, the minor
212     version may start with zero. Using 08 or 09 is a bad idea because users
213     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
214     interpreted as invalid octal numbers. I've updated the previous comment in
215     configure.ac, and also added a check that gives an error if 08 or 09 are
216 ph10 481 used.
217 ph10 486
218 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
219 ph10 483 causing partial matching to fail when the end of the subject matched \W
220     in a UTF-8 pattern where \W was quantified with a minimum of 3.
221 ph10 486
222 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
223 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
224 ph10 483 their definitions. The declarations used "const uschar *" and the
225     definitions used USPTR. Even though USPTR is normally defined as "const
226     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
227     reported that: "This difference in casting confuses some C++ compilers, for
228     example, SunCC recognizes above declarations as different functions and
229 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
230 ph10 483 USPTR.
231 ph10 486
232     16. GNU libtool is named differently on some systems. The autogen.sh script now
233 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
234     (FreeBSD).
235 ph10 478
236 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
237     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
238     comment: "Figure out how to create a longlong from a string: strtoll and
239     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
240     instance, but it only takes 2 args instead of 3!"
241 ph10 479
242 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
243     specification, with a corresponding code fix. A pattern such as
244     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
245     refers, was giving matches when it shouldn't. For example, xa=xaaa would
246     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
247     same bug. Such groups have to be quantified to be useful, or contained
248     inside another quantified group. (If there's no repetition, the reference
249     can never match.) The problem arises because, having left the group and
250     moved on to the rest of the pattern, a later failure that backtracks into
251     the group uses the captured value from the final iteration of the group
252     rather than the correct earlier one. I have fixed this in PCRE by forcing
253     any group that contains a reference to itself to be an atomic group; that
254     is, there cannot be any backtracking into it once it has completed. This is
255     similar to recursive and subroutine calls.
256 ph10 486
257 ph10 488
258 ph10 469 Version 8.00 19-Oct-09
259 ph10 418 ----------------------
261     1. The table for translating pcre_compile() error codes into POSIX error codes
262 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
263     being within the table. This could lead to an OK return being given in
264 ph10 418 error.
265 ph10 461
266     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
267     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
268     in a Windows environment.
270 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
271     zero, as does GNU grep. However, pcregrep was also printing all files when
272     --files-with-matches was added. Now, when both options are given, it prints
273     counts only for those files that have at least one match. (GNU grep just
274 ph10 461 prints the file name in this circumstance, but including the count seems
275     more useful - otherwise, why use --count?) Also ensured that the
276 ph10 420 combination -clh just lists non-zero counts, with no names.
277 ph10 461
278     4. The long form of the pcregrep -F option was incorrectly implemented as
279     --fixed_strings instead of --fixed-strings. This is an incompatible change,
280     but it seems right to fix it, and I didn't think it was worth preserving
281     the old behaviour.
283     5. The command line items --regex=pattern and --regexp=pattern were not
284 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
285 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
286 ph10 422 which are compatible with GNU grep; these now work.
287 ph10 461
288     6. No libpcreposix.pc file was created for pkg-config; there was just
289 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
290 ph10 461
291 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
292 ph10 461 when UCP support is not needed, by modifying the Python script that
293 ph10 425 generates it from Unicode data files. This should not matter if the module
294     is correctly used as a library, but I received one complaint about 50K of
295     unwanted data. My guess is that the person linked everything into his
296     program rather than using a library. Anyway, it does no harm.
297 ph10 461
298 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
299 ph10 461 was a minimum greater than 1 for a wide character in a possessive
300 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
301     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
302     character. Chaos in the form of incorrect output or a compiling loop could
303     result.
304 ph10 461
305 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
306 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
307 ph10 426 partially matched by this function. In addition, if there are at least two
308 ph10 435 slots in the offset vector, the offset of the earliest inspected character
309     for the match and the offset of the end of the subject are set in them when
310 ph10 461 PCRE_ERROR_PARTIAL is returned.
312 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
313     synonymous with PCRE_PARTIAL, for backwards compatibility, and
314     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
315 ph10 462 and may be more useful for multi-segment matching.
316 ph10 461
317     11. Partial matching with pcre_exec() is now more intuitive. A partial match
318     used to be given if ever the end of the subject was reached; now it is
319     given only if matching could not proceed because another character was
320     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
321     string "Z", which now yields "no match" instead of "partial match". In the
322     case of pcre_dfa_exec(), "no match" is given if every matching path for the
323     final character ended with (*FAIL).
325 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
326 ph10 461 if the pattern had a "must contain" character that was already found in the
327 ph10 428 earlier partial match, unless partial matching was again requested. For
328     example, with the pattern /dog.(body)?/, the "must contain" character is
329     "g". If the first part-match was for the string "dog", restarting with
330 ph10 435 "sbody" failed. This bug has been fixed.
331 ph10 461
332     13. The string returned by pcre_dfa_exec() after a partial match has been
333     changed so that it starts at the first inspected character rather than the
334     first character of the match. This makes a difference only if the pattern
335     starts with a lookbehind assertion or \b or \B (\K is not supported by
336     pcre_dfa_exec()). It's an incompatible change, but it makes the two
337 ph10 435 matching functions compatible, and I think it's the right thing to do.
338 ph10 461
339 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
340 ph10 461 so that the demonstration program is easily available in environments where
341     PCRE has not been installed from source.
343 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
344 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
345     library.
346 ph10 461
347 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
348 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
349 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
350 ph10 433 these options useful.
351 ph10 461
352     17. If a caller to the POSIX matching function regexec() passes a non-zero
353 ph10 438 value for nmatch with a NULL value for pmatch, the value of
354 ph10 461 nmatch is forced to zero.
356 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
357 ph10 461 the diff command, as RunTest does. It now checks in the same way as
358 ph10 437 RunTest, and also checks for the -b option.
359 ph10 461
360 ph10 438 19. If an odd number of negated classes containing just a single character
361     interposed, within parentheses, between a forward reference to a named
362 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
363     an internal error, complaining that it could not find the referenced
364 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
365 ph10 461 [The bug was that it was starting one character too far in when skipping
366     over the character class, thus treating the ] as data rather than
367     terminating the class. This meant it could skip too much.]
369 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
370 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
371 ph10 442 to have an empty string match not at the start, even when the pattern is
372 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
374 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
375 ph10 461 than the maximum at the outer level, the higher number was returned, but
376     with unset values at the outer level. The correct (outer level) value is
377 ph10 446 now given.
378 ph10 461
379 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
380     PCRE did not set those parentheses (unlike Perl). I have now found a way to
381     make it do so. The string so far is captured, making this feature
382     compatible with Perl.
383 ph10 461
384     23. The tests have been re-organized, adding tests 11 and 12, to make it
385 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
386 ph10 461
387 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
388 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
389     does. Neither allows recursion.
391     25. I finally figured out how to implement a request to provide the minimum
392     length of subject string that was needed in order to match a given pattern.
393     (It was back references and recursion that I had previously got hung up
394     on.) This code has now been added to pcre_study(); it finds a lower bound
395 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
396     bound, but using it to avoid searching strings that are too short does give
397     some useful speed-ups. The value is available to calling programs via
398     pcre_fullinfo().
399 ph10 461
400 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
401     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
402     study optimizations had never been tested with that matching function.
403     Oops. What is worse, even when it was passed study data, there was a bug in
404     pcre_dfa_exec() that meant it never actually used it. Double oops. There
405     were also very few tests of studied patterns with pcre_dfa_exec().
406 ph10 461
407 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
408     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
409     on the other side of the coin, they are no longer allowed to have different
410     names, because these cannot be distinguished in PCRE, and this has caused
411     confusion. (This is a difference from Perl.)
412 ph10 461
413     28. When duplicate subpattern names are present (necessarily with different
414     numbers, as required by 27 above), and a test is made by name in a
415     conditional pattern, either for a subpattern having been matched, or for
416     recursion in such a pattern, all the associated numbered subpatterns are
417 ph10 459 tested, and the overall condition is true if the condition is true for any
418     one of them. This is the way Perl works, and is also more like the way
419     testing by number works.
420 ph10 418
421 ph10 461
422 ph10 412 Version 7.9 11-Apr-09
423 ph10 376 ---------------------
425 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
426 ph10 376 (pcretest), all targets were linked against these libraries. This included
427     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
428     libraries. This caused unwanted dependencies to be created. This problem
429 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
430 ph10 376 pcretest is linked with readline.
431 ph10 392
432 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
433     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
434     moved outside it again, because FALSE and TRUE are already defined in AIX,
435     but BOOL is not.
436 ph10 392
437     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
438 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
439 ph10 392
440 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
441     hyphens) following file names and line numbers when outputting matching
442 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
443 ph10 376 wording for the --colour (or --color) option.
444 ph10 392
445 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
446     was not coloured; this is different to GNU grep, so I have changed it to be
447     the same.
448 ph10 392
449 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
450 ph10 392 each matching line was coloured. Now it goes on to look for further matches
451     of any of the test patterns, which is the same behaviour as GNU grep.
453     7. A pattern that could match an empty string could cause pcregrep to loop; it
454     doesn't make sense to accept an empty string match in pcregrep, so I have
455 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
456     seems to be how GNU grep behaves.
457 ph10 392
458 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
459 ph10 392 start or after a newline", because the conditional assertion was not being
460     correctly handled. The rule now is that both the assertion and what follows
461     in the first alternative must satisfy the test.
463 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
464 ph10 399 condition was an assertion, PCRE could crash during matching, both with
465     pcre_exec() and pcre_dfa_exec().
466 ph10 392
467     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
468     used for matching.
470     11. Unicode property support in character classes was not working for
471 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
472 ph10 388
473 ph10 392 12. Added the -M command line option to pcretest.
475 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
476 ph10 389
477     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
478 ph10 390
479 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
480 ph10 390 wrapper.
481 ph10 392
482 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
483 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
484 ph10 391 string constants.
485 ph10 405
486 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
487     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
488 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
489     these, but not everybody uses configure.
491     19. A conditional group that had only one branch was not being correctly
492     recognized as an item that could match an empty string. This meant that an
493     enclosing group might also not be so recognized, causing infinite looping
494     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
495     with the subject "ab", where knowledge that the repeated group can match
496 ph10 396 nothing is needed in order to break the loop.
497 ph10 405
498 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
499 ph10 405 exec(), but without supplying a callout function, matching went wrong.
501     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
502     leak if the size of the offset vector was greater than 30. When the vector
503     is smaller, the saved offsets during recursion go onto a local stack
504     vector, but for larger vectors malloc() is used. It was failing to free
505     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
506 ph10 400 error, in fact).
507 ph10 405
508 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
509 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
510     problem, but was untidy.
511 ph10 376
512 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
513     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
514     included within another project.
515 ph10 411
516 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
517     slightly modified by me:
518 ph10 411
519     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
520     not building pcregrep.
522 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
523 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
525 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
526     duplicate group numbers, could behave incorrectly or give incorrect errors,
527     because when scanning forward to find the reference group, PCRE was not
528     taking into account the duplicate group numbers. A pattern such as
529     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
530 ph10 411
531     26. Changed a few more instances of "const unsigned char *" to USPTR, making
532     the feature of a custom pointer more persuasive (as requested by a user).
533 ph10 416
534 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
535 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
536     pre-defined.
537 ph10 392
538 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
540 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
541     in the configuration summary.
542 ph10 405
543 ph10 411
544 ph10 374 Version 7.8 05-Sep-08
545 ph10 349 ---------------------
547     1. Replaced UCP searching code with optimized version as implemented for Ad
548     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
549 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
550     to 5 times on some simple patterns that I tested. Permission was given to
551     distribute the MultiStage2.py script that generates the tables (it's not in
552     the tarball, but is in the Subversion repository).
553 ph10 349
554 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
555     scripts.
556 ph10 358
557 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
558     a group with a zero qualifier. The result of the study could be incorrect,
559 ph10 358 or the function might crash, depending on the pattern.
561     4. Caseless matching was not working for non-ASCII characters in back
562 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
563 ph10 358 It now works when Unicode Property Support is available.
565 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
566     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
567     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
568 ph10 358 truncation.
569 ph10 349
570 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
572 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
573     pointers, in case they are 64-bit values.
574 ph10 371
575     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
576     test 2 if it fails.
578 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
579 ph10 371 and a #define of that name to empty if it is not externally set. This is to
580     allow users of MSVC to set it if necessary.
582     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
583 ph10 359 the convenience functions in the pcre_get.c source file.
584 ph10 371
585 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
586     could cause overwriting and/or a crash. This command provoked a crash in
587 ph10 371 some environments:
589     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
591 ph10 360 This potential security problem was recorded as CVE-2008-2371.
592 ph10 371
593 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
594     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
595 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
596 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
597     pcretest so that it places the subject at the end of its malloc-ed buffer.
598 ph10 371
599 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
600 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
602 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
603 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
604     first line. This applied both to normal and DFA matching.
606 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
607 ph10 371 /^[^d]*?$/8 failed to match "abc".
608 ph10 351
609 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
611     17. Make it more clear in the documentation that values returned from
612 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
613 ph10 357
614 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
615 ph10 368
616 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
617     supplied by Stefan Weber. I made a further small update for 7.8 because
618 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
619     replaced by pcre_ucd.c.
620 ph10 371
621 ph10 373
622 ph10 347 Version 7.7 07-May-08
623 ph10 321 ---------------------
625     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
626 ph10 345 a string to a long long, pretend we don't even have a long long." This is
627 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
628 ph10 345
629 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
630     pre-7.6 versions, which defined a global no_arg variable instead of putting
631 ph10 332 it in the RE class. (See also #8 below.)
632 ph10 345
633     3. Remove a line of dead code, identified by coverity and reported by Nuno
634     Lopes.
636 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
637 ph10 321
638 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
639 ph10 345 of files, instead of just to the final components.
641 ph10 324 (2) If there was more than one level of directory, the subdirectories were
642     skipped unless they satisfied the include/exclude conditions. This is
643     inconsistent with GNU grep (and could even be seen as contrary to the
644     pcregrep specification - which I improved to make it absolutely clear).
645     The action now is always to scan all levels of directory, and just
646     apply the include/exclude patterns to regular files.
647 ph10 345
648 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
649 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
651 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
652 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
653 ph10 326 doesn't support NULs in patterns.
654 ph10 345
655     7. Added some missing "const"s to declarations of static tables in
656     pcre_compile.c and pcre_dfa_exec.c.
658 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
659 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
660 ph10 345 first patch. And a third patch - this was a messy problem.)
661 ph10 321
662 ph10 345 9. Applied Craig's patch to remove the use of push_back().
664 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
665     matching function regexec().
666 ph10 345
667     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
668     which, however, unlike Perl's \g{...}, are subroutine calls, not back
669 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
670     Oniguruma does).
671 ph10 345
672     12. Previously, a group with a zero repeat such as (...){0} was completely
673 ph10 335 omitted from the compiled regex. However, this means that if the group
674     was called as a subroutine from elsewhere in the pattern, things went wrong
675 ph10 345 (an internal error was given). Such groups are now left in the compiled
676     pattern, with a new opcode that causes them to be skipped at execution
677 ph10 335 time.
678 ph10 345
679 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
680     to the way PCRE behaves:
681 ph10 345
682 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
683 ph10 345
684     (b) A back reference to an unmatched subpattern matches an empty string
685 ph10 336 (Perl fails the current match path).
686 ph10 345
687 ph10 341 (c) A data ] in a character class must be notated as \] because if the
688 ph10 345 first data character in a class is ], it defines an empty class. (In
689 ph10 341 Perl it is not possible to have an empty class.) The empty class []
690     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
691     The negative empty class [^] matches any one character, independently
692     of the DOTALL setting.
693 ph10 345
694     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
695 ph10 340 non-existent subpattern following a character class starting with ']' and
696     containing () gave an internal compiling error instead of "reference to
697     non-existent subpattern". Fortunately, when the pattern did exist, the
698 ph10 345 compiled code was correct. (When scanning forwards to check for the
699 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
700 ph10 345 the class, so got the count wrong. When actually compiling, the reference
701 ph10 340 was subsequently set up correctly.)
702 ph10 345
703 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
704 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
705     other assertions are supported. I have made pcre_dfa_exec() support
706     (*FAIL).
708 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
709 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
710     cannot be changed at match time, I realized I could make a small
711     improvement to matching performance by compiling OP_ALLANY instead of
712     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
713     on the OP_ANY path.
715     17. Compiling pcretest on Windows with readline support failed without the
716 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
717 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
719 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
720 ph10 345 ncurses library to be included for pcretest when ReadLine support is
721     requested, but also to allow for it to be overridden. This patch came from
722     Daniel Bergström.
723 ph10 347
724 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
725 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
726     any errors with the current Unicode tables. Thanks to Peter Kankowski for
727     spotting this.
728 ph10 324
729 ph10 332
730 ph10 319 Version 7.6 28-Jan-08
731 ph10 300 ---------------------
733 ph10 302 1. A character class containing a very large number of characters with
734     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
735     overflow.
736 ph10 309
737     2. Patch to cut out the "long long" test in pcrecpp_unittest when
738     HAVE_LONG_LONG is not defined.
740 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
741 ph10 304 bring them up to date and include new features. This patch includes:
742 ph10 309
743 ph10 304 - Fixed PH's badly added libz and libbz2 support.
744     - Fixed a problem with static linking.
745 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
746 ph10 304 - Fixed dftables problem and added an option.
747     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
749     - Added readline support for pcretest.
750 ph10 309 - Added an listing of the option settings after cmake has run.
752 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
753     "pcre.dll" under mingw when using Configure/Make. I added stuff to
754     Makefile.am that cause it to include this special target, without
755     affecting anything else. Note that the same mingw target plus all
756     the other distribution libraries and programs are now supported
757     when configuring with CMake (see 6 below) instead of with
758     Configure/Make.
759 ph10 309
760 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
761     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
762 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
763     solves the problem, but it does no harm.
764 ph10 313
765 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
766 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
767 ph10 314 with CMake, and also correct the comment about stack recursion.
768 ph10 313
769 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
770 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
771     of a program that users should build themselves after PCRE is installed, so
772     building it automatically is not really right. What is more, it gave
773 ph10 312 trouble in some build environments.
774 ph10 300
775 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
776 ph10 308
777 ph10 319
778 ph10 298 Version 7.5 10-Jan-08
779 ph10 263 ---------------------
781     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
782     values in parens when parsing an RE using the C++ wrapper."
783 ph10 286
784 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
785     Characters greater than 255 were excluded from the class instead of being
786     included.
787 ph10 286
788     3. The same bug as (2) above applied to negated POSIX classes such as
789 ph10 265 [:^space:].
790 ph10 286
791 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
792     defined or documented. It seems to have been a typo for PCRE_STATIC, so
793 ph10 286 I have changed it.
795 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
796 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
797     first named subpattern whose name started with "a" (in other words, the
798 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
799     expected" is now given for (?&) (a zero-length name), and this patch also
800     makes it give the same error for \k'' (previously it complained that that
801     was a reference to a non-existent subpattern).
802 ph10 286
803 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
804 ph10 286 this is right because (?- can be followed by option settings as well as by
805 ph10 269 digits. I have, however, made the messages clearer.
806 ph10 286
807 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
808     than the number used in the conditional) now cause a compile-time error.
809     This is actually not compatible with Perl, which accepts such patterns, but
810     treats the conditional as always being FALSE (as PCRE used to), but it
811     seems to me that giving a diagnostic is better.
812 ph10 286
813 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
814 ph10 275 and messages.
815 ph10 286
816     9. Fix two occurrences of "backslash" in comments that should have been
817     "backspace".
819     10. Remove two redundant lines of code that can never be obeyed (their function
820     was moved elsewhere).
822     11. The program that makes PCRE's Unicode character property table had a bug
823     which caused it to generate incorrect table entries for sequences of
824 ph10 277 characters that have the same character type, but are in different scripts.
825 ph10 286 It amalgamated them into a single range, with the script of the first of
826 ph10 277 them. In other words, some characters were in the wrong script. There were
827     thirteen such cases, affecting characters in the following ranges:
828 ph10 286
829 ph10 277 U+002b0 - U+002c1
830     U+0060c - U+0060d
831 ph10 286 U+0061e - U+00612
832 ph10 277 U+0064b - U+0065e
833     U+0074d - U+0076d
834     U+01800 - U+01805
835     U+01d00 - U+01d77
836     U+01d9b - U+01dbf
837     U+0200b - U+0200f
838     U+030fc - U+030fe
839     U+03260 - U+0327f
840     U+0fb46 - U+0fbb1
841     U+10450 - U+1049d
842 ph10 286
843 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
844     compatible with GNU grep in that, if there was more than one match in a
845     line, it showed only the first of them. It now behaves in the same way as
846     GNU grep.
847 ph10 286
848     13. If the -o and -v options were combined for pcregrep, it printed a blank
849     line for every non-matching line. GNU grep prints nothing, and pcregrep now
850     does the same. The return code can be used to tell if there were any
851     non-matching lines.
853 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
855     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
856 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
857 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
858     and both kinds of lookbehind were skipped).
860 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
861 ph10 284 inclusion of <windows.h> to before rather than after the definition of
862     INVALID_FILE_ATTRIBUTES (patch from David Byron).
863 ph10 263
864 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
865 ph10 286 character property caused pcre_compile() to compile bad code, which led at
866     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
867     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
868     caused the error; without that there was no problem.
869 ph10 263
870 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
871 ph10 286
872 ph10 289 19. Added --enable-pcretest-libreadline.
873 ph10 286
874 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
875 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
876 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
877     later patch that removed the other one (the right fix) and added unit tests
878     that check the return values (which was not done before).
879 ph10 292
880 ph10 291 21. Several CMake things:
881 ph10 287
882 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
883 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
884 ph10 288
885 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
886     linked with the newly-built libraries, not previously installed ones.
887 ph10 291
889 ph10 298
890     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
891     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
892     UTF-8 newline character). The key issue is that the pattern starts .*;
893     this means that the match must be either at the beginning, or after a
894     newline. The bug was in the code for advancing after a failed match and
895     checking that the new position followed a newline. It was not taking
896 ph10 294 account of UTF-8 characters correctly.
897 ph10 298
898     23. PCRE was behaving differently from Perl in the way it recognized POSIX
899     character classes. PCRE was not treating the sequence [:...:] as a
900     character class unless the ... were all letters. Perl, however, seems to
901     allow any characters between [: and :], though of course it rejects as
902     unknown any "names" that contain non-letters, because all the known class
903     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
904     for example, whereas PCRE did not - it did not recognize a POSIX character
905     class. This seemed a bit dangerous, so the code has been changed to be
906     closer to Perl. The behaviour is not identical to Perl, because PCRE will
907     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
908     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
909     Perl does, and where it didn't before.
911 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
912     Windows environments %n is disabled by default.
913 ph10 292
915 ph10 260 Version 7.4 21-Sep-07
916 ph10 230 ---------------------
918     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
919 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
920     LF". That isn't really right - the whole point of the change was to try to
921     help when there was an actual mention of one of the two characters. So now
922     the change happens only if \r or \n (or a literal CR or LF) character is
923 ph10 230 encountered.
924 ph10 231
925     2. The 32-bit options word was also used for 6 internal flags, but the numbers
926     of both had grown to the point where there were only 3 bits left.
927     Fortunately, there was spare space in the data structure, and so I have
928     moved the internal flags into a new 16-bit field to free up more option
929 ph10 230 bits.
930 ph10 231
931     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
932     but did not set the internal JCHANGED flag - either of these is enough to
933     control the way the "get" function works - but the PCRE_INFO_JCHANGED
934     facility is supposed to tell if (?J) was ever used, so now (?J) at the
935 ph10 230 start sets both bits.
937 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
938     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
939 ph10 230
940 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
942     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
943 ph10 233 compatibility, even though it is no longer used.
944 ph10 243
945     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
946 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
947 ph10 259 windows.h file is present (where different names are used). [This was
948 ph10 257 reversed later after testing - see 16 below.]
949 ph10 243
950     8. Changed all #include <config.h> to #include "config.h". There were also
951 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
952 ph10 243
953 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
954 ph10 243 sequence off the lines that it output.
956     10. It was pointed out to me that arrays of string pointers cause lots of
957     relocations when a shared library is dynamically loaded. A technique of
958     using a single long string with a table of offsets can drastically reduce
959     these. I have refactored PCRE in four places to do this. The result is
960 ph10 240 dramatic:
961 ph10 243
962 ph10 240 Originally: 290
963     After changing UCP table: 187
964 ph10 243 After changing error message table: 43
965 ph10 240 After changing table of "verbs" 36
966     After changing table of Posix names 22
967 ph10 243
968 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
969 ph10 247
970 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
971 ph10 247 unicode-properties was also set.
973 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
974 ph10 231
975 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
976     checked only for CRLF.
977 ph10 233
978 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
980 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
981 ph10 253
982 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
983 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
984     entirely. This removes changes made in 7 above.
985 ph10 256
986 ph10 261 17. The CMake files have been updated, and there is now more information about
987     building with CMake in the NON-UNIX-USE document.
988 ph10 257
989 ph10 261
990 ph10 228 Version 7.3 28-Aug-07
991 ph10 157 ---------------------
993 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
994     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
995     brackets there is not right, since it causes compilers to look for an
996     installed pcre.h, not the version that is in the source that is being
997     compiled (which of course may be different). I have changed it back to:
998 ph10 197
999 ph10 189 #include "pcre.h"
1000 ph10 197
1001     I have a vague recollection that the change was concerned with compiling in
1002     different directories, but in the new build system, that is taken care of
1003     by the VPATH setting the Makefile.
1005 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1006     when the subject happened to end in the byte 0x85 (e.g. if the last
1007     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1008     characters but of course it shouldn't be taken as a newline when it is part
1009     of another character. The bug was that, for an unlimited repeat of . in
1010     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1011     characters when looking for a newline.
1012 ph10 197
1013     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1015     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1016     in debug output.
1018 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1019     long printing in the pcrecpp unittest when running under MinGW.
1020 ph10 189
1021 ph10 197 6. ESC_K was left out of the EBCDIC table.
1022 ph10 189
1023 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1024     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1025     limit also applies to "virtual nesting" when a pattern is recursive, and in
1026     this case 1000 isn't so big. I have been able to remove this limit at the
1027     expense of backing off one optimization in certain circumstances. Normally,
1028     when pcre_exec() would call its internal match() function recursively and
1029     immediately return the result unconditionally, it uses a "tail recursion"
1030     feature to save stack. However, when a subpattern that can match an empty
1031     string has an unlimited repetition quantifier, it no longer makes this
1032     optimization. That gives it a stack frame in which to save the data for
1033     checking that an empty string has been matched. Previously this was taken
1034     from the 1000-entry workspace that had been reserved. So now there is no
1035     explicit limit, but more stack is used.
1036 ph10 189
1037 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1038     syntax that is required for Windows, and which was going wrong for the
1039     pcreposix and pcrecpp parts of the library. These were overlooked when this
1040     problem was solved for the main library.
1041 ph10 197
1042 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1043     the size of patterns that contain repeated groups with explicit upper
1044     limits. As the maximum quantifier is 65535, the maximum group length was
1045     set at 30,000 so that the product of these two numbers did not overflow a
1046     32-bit integer. However, it turns out that people want to use groups that
1047     are longer than 30,000 bytes (though not repeat them that many times).
1048     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1049     made it possible to implement the integer overflow checks in a much more
1050     dynamic way, which I have now done. The artificial limitation on group
1051     length has been removed - we now have only the limit on the total length of
1052     the compiled pattern, which depends on the LINK_SIZE setting.
1053 ph10 208
1054     10. Fixed a bug in the documentation for get/copy named substring when
1055     duplicate names are permitted. If none of the named substrings are set, the
1056     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1057     empty string.
1059     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1060     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1061     because the ] is interpreted as the first data character and the
1062     terminating ] is not found. PCRE has been made compatible with Perl in this
1063     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1064     cause memory overwriting.
1066 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1067     string has been matched (to stop an infinite loop). It was not recognizing
1068 ph10 208 a conditional subpattern that could match an empty string if that
1069 ph10 206 subpattern was within another subpattern. For example, it looped when
1070 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1071 ph10 206 condition was not nested. This bug has been fixed.
1072 ph10 208
1073 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1074     past the start of the subject in the presence of bytes with the top bit
1075     set, for example "\x8aBCD".
1076 ph10 211
1077 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1078     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1079 ph10 200
1080 ph10 211 14. Optimized (?!) to (*FAIL).
1081 ph10 202
1082 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1083     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1084     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1085     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1086     does: it's just the validity check that is more restrictive.
1087 ph10 220
1088     16. Inserted checks for integer overflows during escape sequence (backslash)
1089     processing, and also fixed erroneous offset values for syntax errors during
1090     backslash processing.
1092 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1093 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1095 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1096     caused an overrun.
1097 ph10 220
1098     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1099     something other than just ASCII characters) inside a group that had an
1100     unlimited repeat caused a loop at compile time (while checking to see
1101     whether the group could match an empty string).
1103 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1104     [\P{Any}] did so. (Error in the code for printing property names.)
1105 ph10 210
1106 ph10 220 21. An orphan \E inside a character class could cause a crash.
1108     22. A repeated capturing bracket such as (A)? could cause a wild memory
1109 ph10 218 reference during compilation.
1110 ph10 220
1111     23. There are several functions in pcre_compile() that scan along a compiled
1112     expression for various reasons (e.g. to see if it's fixed length for look
1113 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1114 ph10 220 present in the pattern. These operators have additional parameters compared
1115     with \d, etc, and these were not being taken into account when moving along
1116 ph10 218 the compiled data. Specifically:
1117 ph10 220
1118     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1119     length.
1121     (b) An item such as \pL+ within a repeated group could cause crashes or
1122 ph10 218 loops.
1123 ph10 220
1124 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1125 ph10 220 "reference to non-existent subpattern" error.
1127 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1129 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1130 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1131 ph10 211
1132 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1133 ph10 218
1134 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1135 ph10 223 character were causing crashes (broken optimization).
1136 ph10 227
1137 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1138 ph10 227 \p or \P) caused a compile-time loop.
1140 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1141     break. For example, the unstudied pattern [\r\n]A does not match the string
1142     "\r\nA" because change 7.0/46 below moves the current point on by two
1143     characters after failing to match at the start. However, the pattern \nA
1144 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1145     the same is true. There doesn't seem any very clean way out of this, but
1146     what I have chosen to do makes the common cases work: PCRE now takes note
1147     of whether there can be an explicit match for \r or \n anywhere in the
1148     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1149     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1150     pattern has explicit CR or LF references.
1151 ph10 222
1152 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1153 ph10 223
1154 ph10 227
1155 ph10 189 Version 7.2 19-Jun-07
1156     ---------------------
1158 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1159     which is apparently normally available under Windows.
1160 ph10 159
1161     2. Re-jig the pcregrep tests with different newline settings in an attempt
1162     to make them independent of the local environment's newline setting.
1163 ph10 157
1164 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1165 ph10 165
1166 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1167     was not 2, because the output contained actual offsets. The recent new
1168 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1169     usable with all link sizes.
1171 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1172     stack recursion. This gives a massive performance boost under BSD, but just
1173 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1174 ph10 164 in all cases.
1175 ph10 172
1176 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1177 ph10 172
1178 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1179     recursion call. It refers to the nth most recently opened parentheses.
1180 ph10 172
1181 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1182 ph10 172 to be opened parentheses.
1184     (c) Conditions that refer to capturing parentheses can be specified
1185 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1186 ph10 172
1187 ph10 168 (d) \K resets the start of the current match so that everything before
1188 ph10 172 is not part of it.
1190 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1191 ph10 172
1192 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1193 ph10 172 reference syntax.
1194 ph10 182
1195 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1196 ph10 182 alternative starts with the same number.
1197 ph10 172
1198 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1200 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1203     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1204     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1205 ph10 170 for detecting groups that can match an empty string.
1206 ph10 159
1207 ph10 172 9. A pattern with a very large number of alternatives (more than several
1208     hundred) was running out of internal workspace during the pre-compile
1209     phase, where pcre_compile() figures out how much memory will be needed. A
1210     bit of new cunning has reduced the workspace needed for groups with
1211     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1212     workspace instead of running out of the 4096 that are available.
1213 ph10 182
1214 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1215 ph10 172
1216 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1217     The report of the bug said:
1218 ph10 182
1219 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1220     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1221 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1222 ph10 185
1223 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1224 ph10 185 it matched the wrong number of bytes.
1225 ph10 172
1226 ph10 179
1227 ph10 155 Version 7.1 24-Apr-07
1228 ph10 98 ---------------------
1230 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1231 ph10 122 that is more "standard", making use of automake and other Autotools. There
1232 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1233     on this.
1234 ph10 111
1235     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1236     for recursive directory scanning broke on some systems because the files
1237     are not scanned in any specific order and on different systems the order
1238     was different. A call to "sort" has been inserted into RunGrepTest for the
1239     approprate test as a short-term fix. In the longer term there may be an
1240 ph10 100 alternative.
1241 ph10 111
1242 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1243 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1244     people do their own conversions for various reasons). The problems
1245     concerned the use of low-level troff macros .br and .in. I have therefore
1246     removed all such uses from the man pages (some were redundant, some could
1247 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1248     HTML has been updated to handle .nf/.fi and to complain if it encounters
1249     .br or .in.
1250 ph10 111
1251 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1252 ph10 123 arranged for config.h to be included in the distribution, with the name
1253 ph10 111 config.h.generic, for the benefit of those who have to compile without
1254     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1256     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1257     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1258 ph10 127 makevp.bat for the current PCRE, using the additional files
1259 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1260 ph10 111
1261     6. A Windows user reported a minor discrepancy with test 2, which turned out
1262     to be caused by a trailing space on an input line that had got lost in his
1263 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1264 ph10 111
1265 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1266 ph10 111 that is needed.
1268 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1269     as "const" (a) because they are and (b) because it helps the PHP
1270     maintainers who have recently made a script to detect big data structures
1271 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1272     to update Builducptable as well, so it won't revert if ucptable.h is ever
1273 ph10 105 re-created.
1274 ph10 111
1275     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1276 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1277 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1278     support is not required. This saves 1.5-2K of code, which is important in
1279 ph10 107 some applications.
1280 ph10 111
1281 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1282 ph10 111 so as not to refer to the tables, even though these functions will never be
1283     called when UTF-8 support is disabled. Otherwise there are problems with a
1284     shared library.
1286 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1288     (a) It was defining its arguments as char * instead of void *.
1290 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1291     a long time ago when I wrote it, but is no longer the case.
1293 ph10 118 The emulated memove() is provided for those environments that have neither
1294 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1295 ph10 118 is clearly not the case, as these two bugs were recently reported.
1296 ph10 123
1297 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1298 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1299     pages, and it removes trailing spaces from listed files. It also creates
1300     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1301     case, it wraps all the #defines with #ifndefs. This script should be run
1302 ph10 111 before "make dist".
1303 ph10 123
1304 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1305     with Unicode property support.
1306 ph10 123
1307     (a) For a maximizing quantifier, if the two different cases of the
1308     character were of different lengths in their UTF-8 codings (there are
1309     some cases like this - I found 11), and the matching function had to
1310 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1311     were both the same length.
1312 ph10 123
1313     (b) When PCRE was configured to use the heap rather than the stack for
1314     recursion during matching, it was not correctly preserving the data for
1315     the other case of a UTF-8 character when checking ahead for a match
1316     while processing a minimizing repeat. If the check also involved
1317 ph10 115 matching a wide character, but failed, corruption could cause an
1318     erroneous result when trying to check for a repeat of the original
1319     character.
1320 ph10 123
1321 ph10 116 13. Some tidying changes to the testing mechanism:
1322 ph10 98
1323 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1324     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1325 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1326     this for UTF-8.) The configure.ac script no longer substitutes the
1327     relevant variables.
1329 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1330     with length and offset values. This means that the output is different
1331     for different internal link sizes. Test 2 is skipped for link sizes
1332     other than 2 because of this, bypassing the problem. Unfortunately,
1333     there was also a test in test 3 (the locale tests) that used /B and
1334 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1335     I have added a new /Z option to pcretest that replaces the length and
1336     offset values with spaces. This is now used to make test 3 independent
1337 ph10 122 of link size. (Test 2 will be tidied up later.)
1338 ph10 123
1339     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1340 ph10 122 segmentation fault instead of returning the appropriate error message.
1341 ph10 134
1342 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1343 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1344     This doesn't seem right; it now treats the CRLF combination as the line
1345     ending, and so does not match in that case. It's only a pattern such as ^$
1346     that would hit this one: something like ^ABC$ would have failed after \r
1347     and then tried again after \r\n.
1349 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1350 ph10 134 in an attempt to make files that differ only in their line terminators
1351     compare equal. This works on Linux.
1352 ph10 142
1353 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1354     as it exited. This is now fixed, thanks to valgrind.
1355 ph10 142
1356 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1357 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1358     was because its rules for how to advance for /g after matching an empty
1359 ph10 143 string at the end of a line did not allow for this case. They now check for
1360     it specially.
1361 ph10 150
1362     20. pcretest is supposed to handle patterns and data of any length, by
1363     extending its buffers when necessary. It was getting this wrong when the
1364 ph10 147 buffer for a data line had to be extended.
1365 ph10 150
1366 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1367 ph10 150 CRLF as a newline sequence.
1368 ph10 152
1369 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1370 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1371     I have nevertheless tidied it up.
1372 ph10 111
1373 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1374 ph10 123
1375 ph10 153 24. Added a man page for pcre-config.
1376 ph10 152
1377 ph10 153
1378 nigel 93 Version 7.0 19-Dec-06
1379     ---------------------
1381     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1382     moving to gcc 4.1.1.
1384     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1385     sys/time.h, which is documented as needed for this function. It doesn't
1386     seem to matter on Linux, but it showed up on some releases of OS X.
1388     3. It seems that there are systems where bytes whose values are greater than
1389     127 match isprint() in the "C" locale. The "C" locale should be the
1390     default when a C program starts up. In most systems, only ASCII printing
1391     characters match isprint(). This difference caused the output from pcretest
1392     to vary, making some of the tests fail. I have changed pcretest so that:
1394     (a) When it is outputting text in the compiled version of a pattern, bytes
1395     other than 32-126 are always shown as hex escapes.
1397     (b) When it is outputting text that is a matched part of a subject string,
1398     it does the same, unless a different locale has been set for the match
1399     (using the /L modifier). In this case, it uses isprint() to decide.
1401     4. Fixed a major bug that caused incorrect computation of the amount of memory
1402     required for a compiled pattern when options that changed within the
1403     pattern affected the logic of the preliminary scan that determines the
1404     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1405     that the computed length was too small. The symptoms of this bug were
1406     either the PCRE error "internal error: code overflow" from pcre_compile(),
1407     or a glibc crash with a message such as "pcretest: free(): invalid next
1408     size (fast)". Examples of patterns that provoked this bug (shown in
1409     pcretest format) are:
1411     /(?-x: )/x
1412     /(?x)(?-x: \s*#\s*)/
1413     /((?i)[\x{c0}])/8
1414     /(?i:[\x{c0}])/8
1416     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1417     is now done differently.
1419     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1420     wrapper classes; (b) implement a new function in the C++ scanner that is
1421     more efficient than the old way of doing things because it avoids levels of
1422     recursion in the regex matching; (c) add a paragraph to the documentation
1423     for the FullMatch() function.
1425     6. The escape sequence \n was being treated as whatever was defined as
1426     "newline". Not only was this contrary to the documentation, which states
1427     that \n is character 10 (hex 0A), but it also went horribly wrong when
1428     "newline" was defined as CRLF. This has been fixed.
1430     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1431     was being set to -1 for the "end of line" case (supposedly a value that no
1432     character can have). Though this value is never used (the check for end of
1433     line is "zero bytes in current character"), it caused compiler complaints.
1434     I've changed it to 0xffffffff.
1436     8. In pcre_version.c, the version string was being built by a sequence of
1437     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1438     string (as it is for production releases) called a macro with an empty
1439     argument. The C standard says the result of this is undefined. The gcc
1440     compiler treats it as an empty string (which was what was wanted) but it is
1441     reported that Visual C gives an error. The source has been hacked around to
1442     avoid this problem.
1444     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1445     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1446     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1447     of them did).
1449     10. Originally, pcretest opened its input and output without "b"; then I was
1450     told that "b" was needed in some environments, so it was added for release
1451     5.0 to both the input and output. (It makes no difference on Unix-like
1452     systems.) Later I was told that it is wrong for the input on Windows. I've
1453     now abstracted the modes into two macros, to make it easier to fiddle with
1454     them, and removed "b" from the input mode under Windows.
1456     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1458     12. Added -help and --help to pcretest as an official way of being reminded
1459     of the options.
1461     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1462     and pcrecpp.cc because they annoy compilers at high warning levels.
1464     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1466     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1467     scripts are not C programs :-) and which was not noticed because it works
1468     on Linux.
1470     16. pcretest is supposed to handle any length of pattern and data line (as one
1471     line or as a continued sequence of lines) by extending its input buffer if
1472     necessary. This feature was broken for very long pattern lines, leading to
1473     a string of junk being passed to pcre_compile() if the pattern was longer
1474     than about 50K.
1476     17. I have done a major re-factoring of the way pcre_compile() computes the
1477     amount of memory needed for a compiled pattern. Previously, there was code
1478     that made a preliminary scan of the pattern in order to do this. That was
1479     OK when PCRE was new, but as the facilities have expanded, it has become
1480     harder and harder to keep it in step with the real compile phase, and there
1481     have been a number of bugs (see for example, 4 above). I have now found a
1482     cunning way of running the real compile function in a "fake" mode that
1483     enables it to compute how much memory it would need, while actually only
1484     ever using a few hundred bytes of working memory and without too many
1485     tests of the mode. This should make future maintenance and development
1486     easier. A side effect of this work is that the limit of 200 on the nesting
1487     depth of parentheses has been removed (though this was never a serious
1488     limitation, I suspect). However, there is a downside: pcre_compile() now
1489     runs more slowly than before (30% or more, depending on the pattern). I
1490     hope this isn't a big issue. There is no effect on runtime performance.
1492     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1493     newline (only possible for the last line of a file) and it was a
1494     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1496     19. Added additional timing features to pcretest. (1) The -tm option now times
1497     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1498     separate command line item, by a number that specifies the number of
1499     repeats to use when timing. The default is 50000; this gives better
1500     precision, but takes uncomfortably long for very large patterns.
1502     20. Extended pcre_study() to be more clever in cases where a branch of a
1503     subpattern has no definite first character. For example, (a*|b*)[cd] would
1504     previously give no result from pcre_study(). Now it recognizes that the
1505     first character must be a, b, c, or d.
1507     21. There was an incorrect error "recursive call could loop indefinitely" if
1508     a subpattern (or the entire pattern) that was being tested for matching an
1509     empty string contained only one non-empty item after a nested subpattern.
1510     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1511     incorrectly, because the \d was being skipped in the check.
1513     22. The pcretest program now has a new pattern option /B and a command line
1514     option -b, which is equivalent to adding /B to every pattern. This causes
1515     it to show the compiled bytecode, without the additional information that
1516     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1517     is the same as /B/I).
1519     23. A new optimization is now able automatically to treat some sequences such
1520     as a*b as a*+b. More specifically, if something simple (such as a character
1521     or a simple class like \d) has an unlimited quantifier, and is followed by
1522     something that cannot possibly match the quantified thing, the quantifier
1523     is automatically "possessified".
1525     24. A recursive reference to a subpattern whose number was greater than 39
1526     went wrong under certain circumstances in UTF-8 mode. This bug could also
1527     have affected the operation of pcre_study().
1529     25. Realized that a little bit of performance could be had by replacing
1530     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1532     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1534     27. Possessive quantifiers such as a++ were previously implemented by turning
1535     them into atomic groups such as ($>a+). Now they have their own opcodes,
1536     which improves performance. This includes the automatically created ones
1537     from 23 above.
1539     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1540     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1541     the first matched character to be a colon. This applied both to named and
1542     numbered groups.
1544     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1546     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1547     building PCRE on Windows easier, so I have included it in the distribution.
1549     31. There is now a check in pcretest against a ridiculously large number being
1550     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1551     loop, the loop is abandoned.
1553     32. Forward references to subpatterns in conditions such as (?(2)...) where
1554     subpattern 2 is defined later cause pcre_compile() to search forwards in
1555     the pattern for the relevant set of parentheses. This search went wrong
1556     when there were unescaped parentheses in a character class, parentheses
1557     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1559     33. "Subroutine" calls and backreferences were previously restricted to
1560     referencing subpatterns earlier in the regex. This restriction has now
1561     been removed.
1563     34. Added a number of extra features that are going to be in Perl 5.10. On the
1564     whole, these are just syntactic alternatives for features that PCRE had
1565     previously implemented using the Python syntax or my own invention. The
1566     other formats are all retained for compatibility.
1568     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1569     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1570     also .NET compatible.
1572     (b) A recursion or subroutine call to a named group can now be defined as
1573     (?&name) as well as (?P>name).
1575     (c) A backreference to a named group can now be defined as \k<name> or
1576     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1577     5.10, are also .NET compatible.
1579     (d) A conditional reference to a named group can now use the syntax
1580     (?(<name>) or (?('name') as well as (?(name).
1582     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1583     groups (named and numbered) that are never evaluated inline, but can be
1584     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1585     is always false. There may be only one alternative in such a group.
1587     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1588     as the simple (?(R). The condition is true only if the most recent
1589     recursion is that of the given number or name. It does not search out
1590     through the entire recursion stack.
1592     (g) The escape \gN or \g{N} has been added, where N is a positive or
1593     negative number, specifying an absolute or relative reference.
1595     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1596     some "unreachable code" warnings.
1598     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1599     things, this adds five new scripts.
1601     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1602     There were also incompatibilities regarding the handling of \Q..\E inside
1603     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1604     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1606     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1607     matches an empty string, and forcibly breaks the loop. There were bugs in
1608     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1609     against aaaa the result was just "a" rather than "aaaa", for example. Two
1610     separate and independent bugs (that affected different cases) have been
1611     fixed.
1613     39. Refactored the code to abolish the use of different opcodes for small
1614     capturing bracket numbers. This is a tidy that I avoided doing when I
1615     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1616     The new approach is not only tidier, it makes it possible to reduce the
1617     memory needed to fix the previous bug (38).
1619     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1620     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1621     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1622     mode.
1624     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1625     report.
1627     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1628     copy construction and assignment in the C++ wrapper.
1630     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1631     couple of bugs that could have given wrong results in the "--newline=crlf"
1632     case.
1634     44. Added a number of casts and did some reorganization of signed/unsigned int
1635     variables following suggestions from Dair Grant. Also renamed the variable
1636     "this" as "item" because it is a C++ keyword.
1638     45. Arranged for dftables to add
1640     #include "pcre_internal.h"
1642     to pcre_chartables.c because without it, gcc 4.x may remove the array
1643     definition from the final binary if PCRE is built into a static library and
1644     dead code stripping is activated.
1646     46. For an unanchored pattern, if a match attempt fails at the start of a
1647     newline sequence, and the newline setting is CRLF or ANY, and the next two
1648     characters are CRLF, advance by two characters instead of one.
1651 nigel 91 Version 6.7 04-Jul-06
1652     ---------------------
1654     1. In order to handle tests when input lines are enormously long, pcretest has
1655     been re-factored so that it automatically extends its buffers when
1656     necessary. The code is crude, but this _is_ just a test program. The
1657     default size has been increased from 32K to 50K.
1659     2. The code in pcre_study() was using the value of the re argument before
1660     testing it for NULL. (Of course, in any sensible call of the function, it
1661     won't be NULL.)
1663     3. The memmove() emulation function in pcre_internal.h, which is used on
1664     systems that lack both memmove() and bcopy() - that is, hardly ever -
1665     was missing a "static" storage class specifier.
1667     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1668     containing an extended class (one that cannot be represented by a bitmap
1669     because it contains high-valued characters or Unicode property items, e.g.
1670     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1671     pattern, but PCRE should not loop if you do not (it no longer does).
1672     [Detail: two cases were found: (a) a repeated subpattern containing an
1673     extended class; (b) a recursive reference to a subpattern that followed a
1674     previous extended class. It wasn't skipping over the extended class
1675     correctly when UTF-8 mode was not set.]
1677     5. A negated single-character class was not being recognized as fixed-length
1678     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1679     compile error "lookbehind assertion is not fixed length".
1681     6. The RunPerlTest auxiliary script was showing an unexpected difference
1682     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1683     write a Perl script that can interpret lines of an input file either as
1684     byte characters or as UTF-8, which is what "perltest" was being required to
1685     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1686     can't do is switch easily at run time between having the "use utf8;" pragma
1687     or not. In the end, I fudged it by using the RunPerlTest script to insert
1688     "use utf8;" explicitly for the UTF-8 tests.
1690     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1691     the end of the subject string, contrary to the documentation and to what
1692     Perl does. This was true of both matching functions. Now it matches only at
1693     the start of the subject and immediately after *internal* newlines.
1695     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1696     a pointer to an int instead of a pointer to an unsigned long int. This
1697     caused problems on 64-bit systems.
1699     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1700     instance of the 'standard' template library not being so standard".
1702     10. There was no check on the number of named subpatterns nor the maximum
1703     length of a subpattern name. The product of these values is used to compute
1704     the size of the memory block for a compiled pattern. By supplying a very
1705     long subpattern name and a large number of named subpatterns, the size
1706     computation could be caused to overflow. This is now prevented by limiting
1707     the length of names to 32 characters, and the number of named subpatterns
1708     to 10,000.
1710     11. Subpatterns that are repeated with specific counts have to be replicated in
1711     the compiled pattern. The size of memory for this was computed from the
1712     length of the subpattern and the repeat count. The latter is limited to
1713     65535, but there was no limit on the former, meaning that integer overflow
1714     could in principle occur. The compiled length of a repeated subpattern is
1715     now limited to 30,000 bytes in order to prevent this.
1717     12. Added the optional facility to have named substrings with the same name.
1719     13. Added the ability to use a named substring as a condition, using the
1720     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1721     are numbers (not recommended). Forward references are permitted.
1723     14. Added forward references in named backreferences (if you see what I mean).
1725     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1726     pattern could run off the end of the subject. For example, the pattern
1727     "(?s)(.{1,5})"8 did this with the subject "ab".
1729     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1730     PCRE_CASELESS was set when matching characters that were quantified with ?
1731     or *.
1733     17. A character class other than a single negated character that had a minimum
1734     but no maximum quantifier - for example [ab]{6,} - was not handled
1735     correctly by pce_dfa_exec(). It would match only one character.
1737     18. A valid (though odd) pattern that looked like a POSIX character
1738     class but used an invalid character after [ (for example [[,abc,]]) caused
1739     pcre_compile() to give the error "Failed: internal error: code overflow" or
1740     in some cases to crash with a glibc free() error. This could even happen if
1741     the pattern terminated after [[ but there just happened to be a sequence of
1742     letters, a binary zero, and a closing ] in the memory that followed.
1744     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1745     over the years. Originally (before any Unicode support), just the bottom 8
1746     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1747     output from "man perlunicode" includes this:
1749     The regular expression compiler produces polymorphic opcodes. That
1750     is, the pattern adapts to the data and automatically switches to
1751     the Unicode character scheme when presented with Unicode data--or
1752     instead uses a traditional byte scheme when presented with byte
1753     data.
1755     Sadly, a wide octal escape does not cause a switch, and in a string with
1756     no other multibyte characters, these octal escapes are treated as before.
1757     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1758     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1759     Unicode string.
1761     I have not perpetrated such confusion in PCRE. Up till now, it took just
1762     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1763     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1764     translate to the appropriate multibyte character.
1766     29. Applied some refactoring to reduce the number of warnings from Microsoft
1767     and Borland compilers. This has included removing the fudge introduced
1768     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1769     a warning about an unused variable.
1771     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1772     characters since release 4.0, because Perl (from release 5.004) does not.
1773     [Or at least, is documented not to: some releases seem to be in conflict
1774     with the documentation.] However, when a pattern was studied with
1775     pcre_study() and all its branches started with \s, PCRE still included VT
1776     as a possible starting character. Of course, this did no harm; it just
1777     caused an unnecessary match attempt.
1779     22. Removed a now-redundant internal flag bit that recorded the fact that case
1780     dependency changed within the pattern. This was once needed for "required
1781     byte" processing, but is no longer used. This recovers a now-scarce options
1782     bit. Also moved the least significant internal flag bit to the most-
1783     significant bit of the word, which was not previously used (hangover from
1784     the days when it was an int rather than a uint) to free up another bit for
1785     the future.
1787     23. Added support for CRLF line endings as well as CR and LF. As well as the
1788     default being selectable at build time, it can now be changed at runtime
1789     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1790     specify that it is scanning data with non-default line endings.
1792     24. Changed the definition of CXXLINK to make it agree with the definition of
1793     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1795     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1796     recursions. This makes a big different to stack usage for some patterns.
1798     26. If a subpattern containing a named recursion or subroutine reference such
1799     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1800     the space required for the compiled pattern went wrong and gave too small a
1801     value. Depending on the environment, this could lead to "Failed: internal
1802     error: code overflow at offset 49" or "glibc detected double free or
1803     corruption" errors.
1805     27. Applied patches from Google (a) to support the new newline modes and (b) to
1806     advance over multibyte UTF-8 characters in GlobalReplace.
1808     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1809     difference for some implementation of PCRE in some Windows version.
1811     29. Added some extra testing facilities to pcretest:
1813     \q<number> in a data line sets the "match limit" value
1814     \Q<number> in a data line sets the "match recursion limt" value
1815     -S <number> sets the stack size, where <number> is in megabytes
1817     The -S option isn't available for Windows.
1820 nigel 89 Version 6.6 06-Feb-06
1821     ---------------------
1823     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1824     in pcreposix.h. I have copied the definition from pcre.h.
1826     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1827     because pcre.h is no longer a built file.
1829     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1830     not normally included in the compiled code.
1833 nigel 87 Version 6.5 01-Feb-06
1834     ---------------------
1836     1. When using the partial match feature with pcre_dfa_exec(), it was not
1837     anchoring the second and subsequent partial matches at the new starting
1838     point. This could lead to incorrect results. For example, with the pattern
1839     /1234/, partially matching against "123" and then "a4" gave a match.
1841     2. Changes to pcregrep:
1843     (a) All non-match returns from pcre_exec() were being treated as failures
1844     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1845     error message is output. Some extra information is given for the
1847     probably the only errors that are likely to be caused by users (by
1848     specifying a regex that has nested indefinite repeats, for instance).
1849     If there are more than 20 of these errors, pcregrep is abandoned.
1851     (b) A binary zero was treated as data while matching, but terminated the
1852     output line if it was written out. This has been fixed: binary zeroes
1853     are now no different to any other data bytes.
1855     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1856     used to set a locale for matching. The --locale=xxxx long option has
1857     been added (no short equivalent) to specify a locale explicitly on the
1858     pcregrep command, overriding the environment variables.
1860     (d) When -B was used with -n, some line numbers in the output were one less
1861     than they should have been.
1863     (e) Added the -o (--only-matching) option.
1865     (f) If -A or -C was used with -c (count only), some lines of context were
1866     accidentally printed for the final match.
1868     (g) Added the -H (--with-filename) option.
1870     (h) The combination of options -rh failed to suppress file names for files
1871     that were found from directory arguments.
1873     (i) Added the -D (--devices) and -d (--directories) options.
1875     (j) Added the -F (--fixed-strings) option.
1877     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1879     (l) Added the --colo(u)r option.
1881     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1882     is not present by default.
1884     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1885     items such as (?R) or (?1), when the recursion could match a number of
1886     alternatives. If it matched one of the alternatives, but subsequently,
1887     outside the recursion, there was a failure, the code tried to back up into
1888     the recursion. However, because of the way PCRE is implemented, this is not
1889     possible, and the result was an incorrect result from the match.
1891     In order to prevent this happening, the specification of recursion has
1892     been changed so that all such subpatterns are automatically treated as
1893     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1895     4. I had overlooked the fact that, in some locales, there are characters for
1896     which isalpha() is true but neither isupper() nor islower() are true. In
1897     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1898     and ordfeminine) are like this. This affected the treatment of \w and \W
1899     when they appeared in character classes, but not when they appeared outside
1900     a character class. The bit map for "word" characters is now created
1901     separately from the results of isalnum() instead of just taking it from the
1902     upper, lower, and digit maps. (Plus the underscore character, of course.)
1904     5. The above bug also affected the handling of POSIX character classes such as
1905     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1906     permanent tables. Instead, the bit maps for such a class were previously
1907     created as the appropriate unions of the upper, lower, and digit bitmaps.
1908     Now they are created by subtraction from the [[:word:]] class, which has
1909     its own bitmap.
1911     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1912     It is created by subtracting the vertical space characters (\x09, \x0a,
1913     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1914     subtraction was done in the overall bitmap for a character class, meaning
1915     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1916     be recognized. This bug has been fixed.
1918     7. Patches from the folks at Google:
1920     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1921     real life, but is still worth protecting against".
1923     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1924     regular expressions".
1926     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1927     have it.
1929     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1930     "configure" and the latter not, in order to fix a problem somebody had
1931     with compiling the Arg class on HP-UX.
1933     (e) Improve the error-handling of the C++ wrapper a little bit.
1935     (f) New tests for checking recursion limiting.
1937     8. The pcre_memmove() function, which is used only if the environment does not
1938     have a standard memmove() function (and is therefore rarely compiled),
1939     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1940     returning a result (though PCRE never actually uses the result).
1942     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1943     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1944     returned instead of calling malloc() with an overflowing number that would
1945     most likely cause subsequent chaos.
1947     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1949     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1950     with this option is matched, the nmatch and pmatch options of regexec() are
1951     ignored.
1953     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1954     provided in case anyone wants to the the POSIX interface with UTF-8
1955     strings.
1957     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1958     C++ linking (needed for some HP-UX environments).
1960     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1961     (unused parameter) and in the pcre_printint() function (omitted "default"
1962     switch label when the default is to do nothing).
1964     15. Added some code to make it possible, when PCRE is compiled as a C++
1965     library, to replace subject pointers for pcre_exec() with a smart pointer
1966     class, thus making it possible to process discontinuous strings.
1968     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1969     much the same function. They were added by different people who were trying
1970     to make PCRE easy to compile on non-Unix systems. It has been suggested
1971     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1972     for compiling on Windows systems. I have therefore replaced it with
1973     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1974     defaults to "extern" for C or "extern C" for C++, which works fine on
1975     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1976     SCOPE with something explicit in config.h. In addition:
1978     (a) pcreposix.h still had just "extern" instead of either of these macros;
1979     I have replaced it with PCRE_DATA_SCOPE.
1981     (b) Functions such as _pcre_xclass(), which are internal to the library,
1982     but external in the C sense, all had PCRE_EXPORT in their definitions.
1983     This is apparently wrong for the Windows case, so I have removed it.
1984     (It makes no difference on Unix-like systems.)
1986     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1987     of recursive calls to match(). This is different to MATCH_LIMIT because
1988     that limits the total number of calls to match(), not all of which increase
1989     the depth of recursion. Limiting the recursion depth limits the amount of
1990     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1991     when PCRE is compiled, and changed at run time. A patch from Google adds
1992     this functionality to the C++ interface.
1994     18. Changes to the handling of Unicode character properties:
1996     (a) Updated the table to Unicode 4.1.0.
1998     (b) Recognize characters that are not in the table as "Cn" (undefined).
2000     (c) I revised the way the table is implemented to a much improved format
2001     which includes recognition of ranges. It now supports the ranges that
2002     are defined in UnicodeData.txt, and it also amalgamates other
2003     characters into ranges. This has reduced the number of entries in the
2004     table from around 16,000 to around 3,000, thus reducing its size
2005     considerably. I realized I did not need to use a tree structure after
2006     all - a binary chop search is just as efficient. Having reduced the
2007     number of entries, I extended their size from 6 bytes to 8 bytes to
2008     allow for more data.
2010     (d) Added support for Unicode script names via properties such as \p{Han}.
2012     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2013     matching that character.
2015     20. When matching a repeated Unicode property with a minimum greater than zero,
2016     (for example \pL{2,}), PCRE could look past the end of the subject if it
2017     reached it while seeking the minimum number of characters. This could
2018     happen only if some of the characters were more than one byte long, because
2019     there is a check for at least the minimum number of bytes.
2021     21. Refactored the implementation of \p and \P so as to be more general, to
2022     allow for more different types of property in future. This has changed the
2023     compiled form incompatibly. Anybody with saved compiled patterns that use
2024     \p or \P will have to recompile them.
2026     22. Added "Any" and "L&" to the supported property types.
2028     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2029     but give a compile time error if the value is greater than 0xff.
2031     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2032     accidentally not being installed or uninstalled.
2034     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2035     made were to insert the current release number. This seemed silly, because
2036     it made things harder for people building PCRE on systems that don't run
2037     "configure". I have turned pcre.h into a distributed file, no longer built
2038     by "configure", with the version identification directly included. There is
2039     no longer a pcre.h.in file.
2041     However, this change necessitated a change to the pcre-config script as
2042     well. It is built from pcre-config.in, and one of the substitutions was the
2043     release number. I have updated configure.ac so that ./configure now finds
2044     the release number by grepping pcre.h.
2046     26. Added the ability to run the tests under valgrind.
2049 nigel 85 Version 6.4 05-Sep-05
2050     ---------------------
2052     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2053     "--" to be printed when multiple files were scanned, even when none of the
2054     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2055     consider it to be a bug, and have restored the previous behaviour.
2057     2. A couple of code tidies to get rid of compiler warnings.
2059     3. The pcretest program used to cheat by referring to symbols in the library
2060     whose names begin with _pcre_. These are internal symbols that are not
2061     really supposed to be visible externally, and in some environments it is
2062     possible to suppress them. The cheating is now confined to including
2063     certain files from the library's source, which is a bit cleaner.
2065     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2066     file's purpose clearer.
2068     5. Reorganized pcre_ucp_findchar().
2071 nigel 83 Version 6.3 15-Aug-05
2072     ---------------------
2074     1. The file libpcre.pc.in did not have general read permission in the tarball.
2076     2. There were some problems when building without C++ support:
2078     (a) If C++ support was not built, "make install" and "make test" still
2079     tried to test it.
2081     (b) There were problems when the value of CXX was explicitly set. Some
2082     changes have been made to try to fix these, and ...
2084     (c) --disable-cpp can now be used to explicitly disable C++ support.
2086     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2087     backslash in a target when C++ was disabled. This confuses some
2088     versions of "make", apparently. Using an intermediate variable solves
2089     this. (Same for CPP_LOBJ.)
2091     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2092     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2093     necessary on certain architectures.
2095     4. Added a setting of -export-symbols-regex to the link command to remove
2096     those symbols that are exported in the C sense, but actually are local
2097     within the library, and not documented. Their names all begin with
2098     "_pcre_". This is not a perfect job, because (a) we have to except some
2099     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2100     available (and never for static libraries). I have made a note to try to
2101     find a way round (a) in the future.
2104 nigel 81 Version 6.2 01-Aug-05
2105     ---------------------
2107     1. There was no test for integer overflow of quantifier values. A construction
2108     such as {1111111111111111} would give undefined results. What is worse, if
2109     a minimum quantifier for a parenthesized subpattern overflowed and became
2110     negative, the calculation of the memory size went wrong. This could have
2111     led to memory overwriting.
2113     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2115     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2116     operating environments where this matters.
2118     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2119     PCRE options from within the C++ wrapper.
2121     5. Named capturing subpatterns were not being correctly counted when a pattern
2122     was compiled. This caused two problems: (a) If there were more than 100
2123     such subpatterns, the calculation of the memory needed for the whole
2124     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2125     back references of the form \12, where the number was greater than 9, were
2126     not recognized as back references, even though there were sufficient
2127     previous subpatterns.
2129     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2130     versions of gcc, e.g. 2.95.4.
2133 nigel 79 Version 6.1 21-Jun-05
2134     ---------------------
2136     1. There was one reference to the variable "posix" in pcretest.c that was not
2137     surrounded by "#if !defined NOPOSIX".
2139     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2140     the cross-check on the old pcre_info() function, for the benefit of the
2141     cut-down version of PCRE that is currently imported into Exim.
2143     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2144     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2145     patterns that start (?i) but I don't think that matters. The use of (?i) is
2146     just an example; this all applies to the other options as well.
2148     4. Since libtool seems to echo the compile commands it is issuing, the output
2149     from "make" can be reduced a bit by putting "@" in front of each libtool
2150     compile command.
2152     5. Patch from the folks at Google for configure.in to be a bit more thorough
2153     in checking for a suitable C++ installation before trying to compile the
2154     C++ stuff. This should fix a reported problem when a compiler was present,
2155     but no suitable headers.
2157     6. The man pages all had just "PCRE" as their title. I have changed them to
2158     be the relevant file name. I have also arranged that these names are
2159     retained in the file doc/pcre.txt, which is a concatenation in text format
2160     of all the man pages except the little individual ones for each function.
2162     7. The NON-UNIX-USE file had not been updated for the different set of source
2163     files that come with release 6. I also added a few comments about the C++
2164     wrapper.
2167 nigel 77 Version 6.0 07-Jun-05
2168     ---------------------
2170     1. Some minor internal re-organization to help with my DFA experiments.
2172     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2173     didn't matter for the library itself when fully configured, but did matter
2174     when compiling without UCP support, or within Exim, where the ucp files are
2175     not imported.
2177     3. Refactoring of the library code to split up the various functions into
2178     different source modules. The addition of the new DFA matching code (see
2179     below) to a single monolithic source would have made it really too
2180     unwieldy, quite apart from causing all the code to be include in a
2181     statically linked application, when only some functions are used. This is
2182     relevant even without the DFA addition now that patterns can be compiled in
2183     one application and matched in another.
2185     The downside of splitting up is that there have to be some external
2186     functions and data tables that are used internally in different modules of
2187     the library but which are not part of the API. These have all had their
2188     names changed to start with "_pcre_" so that they are unlikely to clash
2189     with other external names.
2191     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2192     a different (DFA) algorithm. Although it is slower than the original
2193     function, it does have some advantages for certain types of matching
2194     problem.
2196     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2197     including restarting after a partial match.
2199     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2200     defined when compiling for Windows was sent to me. I have put it into the
2201     code, though I have no means of testing or verifying it.
2203     7. Added the pcre_refcount() auxiliary function.
2205     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2206     match before or at the first newline in the subject string. In pcretest,
2207     the /f option on a pattern can be used to set this.
2209     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2210     would behave wrongly. This has been present in PCRE since release 4.0.
2212     10. A number of changes to the pcregrep command:
2214     (a) Refactored how -x works; insert ^(...)$ instead of setting
2215     PCRE_ANCHORED and checking the length, in preparation for adding
2216     something similar for -w.
2218     (b) Added the -w (match as a word) option.
2220     (c) Refactored the way lines are read and buffered so as to have more
2221     than one at a time available.
2223     (d) Implemented a pcregrep test script.
2225     (e) Added the -M (multiline match) option. This allows patterns to match
2226     over several lines of the subject. The buffering ensures that at least
2227     8K, or the rest of the document (whichever is the shorter) is available
2228     for matching (and similarly the previous 8K for lookbehind assertions).
2230     (f) Changed the --help output so that it now says
2232     -w, --word-regex(p)
2234     instead of two lines, one with "regex" and the other with "regexp"
2235     because that confused at least one person since the short forms are the
2236     same. (This required a bit of code, as the output is generated
2237     automatically from a table. It wasn't just a text change.)
2239     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2240     option but starts with a hyphen. Could be a pattern or a path name
2241     starting with a hyphen, for instance.
2243     (h) "-" can be given as a file name to represent stdin.
2245     (i) When file names are being printed, "(standard input)" is used for
2246     the standard input, for compatibility with GNU grep. Previously
2247     "<stdin>" was used.
2249     (j) The option --label=xxx can be used to supply a name to be used for
2250     stdin when file names are being printed. There is no short form.
2252     (k) Re-factored the options decoding logic because we are going to add
2253     two more options that take data. Such options can now be given in four
2254     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2256     (l) Added the -A, -B, and -C options for requesting that lines of context
2257     around matches be printed.
2259     (m) Added the -L option to print the names of files that do not contain
2260     any matching lines, that is, the complement of -l.
2262     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2263     continue to scan other files.
2265     (o) The -s option was incorrectly implemented. For compatibility with other
2266     greps, it now suppresses the error message for a non-existent or non-
2267     accessible file (but not the return code). There is a new option called
2268     -q that suppresses the output of matching lines, which was what -s was
2269     previously doing.
2271     (p) Added --include and --exclude options to specify files for inclusion
2272     and exclusion when recursing.
2274     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2275     Hopefully, it now does.
2277     12. Missing cast in pcre_study().
2279     13. Added an "uninstall" target to the makefile.
2281     14. Replaced "extern" in the function prototypes in Makefile.in with
2282     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2283     world, but is set differently for Windows.
2285     15. Added a second compiling function called pcre_compile2(). The only
2286     difference is that it has an extra argument, which is a pointer to an
2287     integer error code. When there is a compile-time failure, this is set
2288     non-zero, in addition to the error test pointer being set to point to an
2289     error message. The new argument may be NULL if no error number is required
2290     (but then you may as well call pcre_compile(), which is now just a
2291     wrapper). This facility is provided because some applications need a
2292     numeric error indication, but it has also enabled me to tidy up the way
2293     compile-time errors are handled in the POSIX wrapper.
2295     16. Added VPATH=.libs to the makefile; this should help when building with one
2296     prefix path and installing with another. (Or so I'm told by someone who
2297     knows more about this stuff than I do.)
2299     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2300     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2301     match everything, including newlines. This is not POSIX-compatible, but
2302     somebody wanted the feature. From pcretest it can be activated by using
2303     both the P and the s flags.
2305     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2307     19. libpcre.pc was being incorrectly installed as executable.
2309     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2310     it now also looks for '\r' so that it will work unmodified on Windows.
2312     21. Added Google's contributed C++ wrapper to the distribution.
2314     22. Added some untidy missing memory free() calls in pcretest, to keep
2315     Electric Fence happy when testing.
2319 nigel 75 Version 5.0 13-Sep-04
2320     ---------------------
2322     1. Internal change: literal characters are no longer packed up into items
2323     containing multiple characters in a single byte-string. Each character
2324     is now matched using a separate opcode. However, there may be more than one
2325     byte in the character in UTF-8 mode.
2327     2. The pcre_callout_block structure has two new fields: pattern_position and
2328     next_item_length. These contain the offset in the pattern to the next match
2329     item, and its length, respectively.
2331     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2332     insertion of callouts before each pattern item. Added the /C option to
2333     pcretest to make use of this.
2335     4. On the advice of a Windows user, the lines
2337     #if defined(_WIN32) || defined(WIN32)
2338     _setmode( _fileno( stdout ), 0x8000 );
2339     #endif /* defined(_WIN32) || defined(WIN32) */
2341     have been added to the source of pcretest. This apparently does useful
2342     magic in relation to line terminators.
2344     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2345     for the benefit of those environments where the "b" makes a difference.
2347     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2348     to know about it. I have put a hack into configure.in that adds in code
2349     to set GCC=yes if CC=icc. This seems to end up at a point in the
2350     generated configure script that is early enough to affect the setting of
2351     compiler options, which is what is needed, but I have no means of testing
2352     whether it really works. (The user who reported this had patched the
2353     generated configure script, which of course I cannot do.)
2355     LATER: After change 22 below (new libtool files), the configure script
2356     seems to know about icc (and also ecc). Therefore, I have commented out
2357     this hack in configure.in.
2359     7. Added support for pkg-config (2 patches were sent in).
2361     8. Negated POSIX character classes that used a combination of internal tables
2362     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2363     [[:^ascii]]. Typically, they would match almost any characters. The other
2364     POSIX classes were not broken in this way.
2366     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2367     to find the match, as PCRE was deluded into thinking that the match had to
2368     start at the start point or following a newline. The same bug applied to
2369     patterns with negative forward assertions or any backward assertions
2370     preceding ".*" at the start, unless the pattern required a fixed first
2371     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2373     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2374     starting at the last subject character, bytes beyond the end of the subject
2375     string were read.
2377     11. Renamed the variable "class" as "classbits" to make life easier for C++
2378     users. (Previously there was a macro definition, but it apparently wasn't
2379     enough.)
2381     12. Added the new field "tables" to the extra data so that tables can be passed
2382     in at exec time, or the internal tables can be re-selected. This allows
2383     a compiled regex to be saved and re-used at a later time by a different
2384     program that might have everything at different addresses.
2386     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2387     -R library as well as a -L library.
2389     14. The debugging options of pcretest (-d on the command line or D on a
2390     pattern) showed incorrect output for anything following an extended class
2391     that contained multibyte characters and which was followed by a quantifier.
2393     15. Added optional support for general category Unicode character properties
2394     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2395     support. It adds about 90K to the size of the library. The meanings of the
2396     inbuilt class escapes such as \d and \s have NOT been changed.
2398     16. Updated pcredemo.c to include calls to free() to release the memory for the
2399     compiled pattern.
2401     17. The generated file chartables.c was being created in the source directory
2402     instead of in the building directory. This caused the build to fail if the
2403     source directory was different from the building directory, and was
2404     read-only.
2406     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2407     file. No doubt somebody will tell me if they don't make sense... Also added
2408     Dan Mooney's comments about building on OpenVMS.
2410     19. Added support for partial matching via the PCRE_PARTIAL option for
2411     pcre_exec() and the \P data escape in pcretest.
2413     20. Extended pcretest with 3 new pattern features:
2415     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2416     write the compiled pattern to the file whose name is "rest-of-line".
2417     This is a straight binary dump of the data, with the saved pointer to
2418     the character tables forced to be NULL. The study data, if any, is
2419     written too. After writing, pcretest reads a new pattern.
2421     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2422     compiled pattern from the given file. There must not be any
2423     occurrences of "<" in the file name (pretty unlikely); if there are,
2424     pcretest will instead treat the initial "<" as a pattern delimiter.
2425     After reading in the pattern, pcretest goes on to read data lines as
2426     usual.
2428     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2429     and 16-bit fields in a compiled pattern, to simulate a pattern that
2430     was compiled on a host of opposite endianness.
2432     21. The pcre-exec() function can now cope with patterns that were compiled on
2433     hosts of opposite endianness, with this restriction:
2435     As for any compiled expression that is saved and used later, the tables
2436     pointer field cannot be preserved; the extra_data field in the arguments
2437     to pcre_exec() should be used to pass in a tables address if a value
2438     other than the default internal tables were used at compile time.
2440     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2441     now diagnosed as an error. Previously, most of the time, a negative number
2442     would have been treated as zero, but if in addition "ovector" was passed as
2443     NULL, a crash could occur.
2445     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2446     new versions from the libtool 1.5 distribution (the last one is a copy of
2447     a file called libtool.m4). This seems to have fixed the need to patch
2448     "configure" to support Darwin 1.3 (which I used to do). However, I still
2449     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2450     workstation).
2452     24. Changed the PCRE licence to be the more standard "BSD" licence.
2455 nigel 73 Version 4.5 01-Dec-03
2456     ---------------------
2458     1. There has been some re-arrangement of the code for the match() function so
2459     that it can be compiled in a version that does not call itself recursively.
2460     Instead, it keeps those local variables that need separate instances for
2461     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2462     needs to "recurse". Keeping track of where control must go is done by means
2463     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2464     hide most of the details from the main code, and operates only if
2465     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2466     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2467     operating.
2469     To make it easier for callers to provide specially tailored get/free
2470     functions for this usage, two new functions, pcre_stack_malloc, and
2471     pcre_stack_free, are used. They are always called in strict stacking order,
2472     and the size of block requested is always the same.
2474     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2475     PCRE has been compiled to use the stack or the heap for recursion. The
2476     -C option of pcretest uses this to show which version is compiled.
2478     A new data escape \S, is added to pcretest; it causes the amounts of store
2479     obtained and freed by both kinds of malloc/free at match time to be added
2480     to the output.
2482     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2483     what's available on my current Linux desktop machine.
2485     3. When matching a UTF-8 string, the test for a valid string at the start has
2486     been extended. If start_offset is not zero, PCRE now checks that it points
2487     to a byte that is the start of a UTF-8 character. If not, it returns
2488     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2489     this is necessary because there may be backward assertions in the pattern.
2490     When matching the same subject several times, it may save resources to use
2491     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2493     4. The code for checking the validity of UTF-8 strings has been tightened so
2494     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2495     containing "overlong sequences".
2497     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2498     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2499     should have been "&", but it just so happened that all the cases this let
2500     through by mistake were picked up later in the function.
2502     6. I had used a variable called "isblank" - this is a C99 function, causing
2503     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2505     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2506     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2507     so the version is shown; (c) stop "make test" echoing "./RunTest".
2509     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2511     9. The prototype for memmove() for systems that don't have it was using
2512     size_t, but the inclusion of the header that defines size_t was later. I've
2513     moved the #includes for the C headers earlier to avoid this.
2515     10. Added some adjustments to the code to make it easier to compiler on certain
2516     special systems:
2518     (a) Some "const" qualifiers were missing.
2519     (b) Added the macro EXPORT before all exported functions; by default this
2520     is defined to be empty.
2521     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2522     that it reads its output file name as an argument instead of writing
2523     to the standard output and assuming this can be redirected.
2525     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2526     class containing characters with values greater than 255, PCRE compilation
2527     went into a loop.
2529     12. A recursive reference to a subpattern that was within another subpattern
2530     that had a minimum quantifier of zero caused PCRE to crash. For example,
2531     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2532     recursion. If the recursively-called subpattern itself had a zero repeat,
2533     that was OK.
2535     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2536     buffer into which it was copied (for escape processing) was still set at
2537     1024, so long lines caused crashes.
2539     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2540     "internal error: code overflow...". This applied to any character class
2541     that was followed by a possessive quantifier.
2543     15. Modified the Makefile to add libpcre.la as a prerequisite for
2544     libpcreposix.la because I was told this is needed for a parallel build to
2545     work.
2547     16. If a pattern that contained .* following optional items at the start was
2548     studied, the wrong optimizing data was generated, leading to matching
2549     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2550     matching string must start with a or b or c. The correct conclusion for
2551     this pattern is that a match can start with any character.
2554 nigel 71 Version 4.4 13-Aug-03
2555     ---------------------
2557     1. In UTF-8 mode, a character class containing characters with values between
2558     127 and 255 was not handled correctly if the compiled pattern was studied.
2559     In fixing this, I have also improved the studying algorithm for such
2560     classes (slightly).
2562     2. Three internal functions had redundant arguments passed to them. Removal
2563     might give a very teeny performance improvement.
2565     3. Documentation bug: the value of the capture_top field in a callout is *one
2566     more than* the number of the hightest numbered captured substring.
2568     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2569     in incorrectly linking with a previously installed version. They now link
2570     explicitly with libpcre.la.
2572     5. configure.in no longer needs to recognize Cygwin specially.
2574     6. A problem in pcre.in for Windows platforms is fixed.
2576     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2577     pcretest, it used to include the size of the study block as part of its
2578     output. Unfortunately, the structure contains a field that has a different
2579     size on different hardware architectures. This meant that the tests that
2580     showed this size failed. As the block is currently always of a fixed size,
2581     this information isn't actually particularly useful in pcretest output, so
2582     I have just removed it.
2584     8. Three pre-processor statements accidentally did not start in column 1.
2585     Sadly, there are *still* compilers around that complain, even though
2586     standard C has not required this for well over a decade. Sigh.
2588     9. In pcretest, the code for checking callouts passed small integers in the
2589     callout_data field, which is a void * field. However, some picky compilers
2590     complained about the casts involved for this on 64-bit systems. Now
2591     pcretest passes the address of the small integer instead, which should get
2592     rid of the warnings.
2594     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2595     both compile and run time, and gives an error if an invalid UTF-8 sequence
2596     is found. There is a option for disabling this check in cases where the
2597     string is known to be correct and/or the maximum performance is wanted.
2599     11. In response to a bug report, I changed one line in Makefile.in from
2601     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2602     to
2603     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2605     to look similar to other lines, but I have no way of telling whether this
2606     is the right thing to do, as I do not use Windows. No doubt I'll get told
2607     if it's wrong...
2610 nigel 69 Version 4.3 21-May-03
2611     ---------------------
2613     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2614     Makefile.
2616     2. Some refactoring to improve the quality of the code:
2618     (i) The utf8_table... variables are now declared "const".
2620     (ii) The code for \cx, which used the "case flipping" table to upper case
2621     lower case letters, now just substracts 32. This is ASCII-specific,
2622     but the whole concept of \cx is ASCII-specific, so it seems
2623     reasonable.
2625     (iii) PCRE was using its character types table to recognize decimal and
2626     hexadecimal digits in the pattern. This is silly, because it handles
2627     only 0-9, a-f, and A-F, but the character types table is locale-
2628     specific, which means strange things might happen. A private
2629     table is now used for this - though it costs 256 bytes, a table is
2630     much faster than multiple explicit tests. Of course, the standard
2631     character types table is still used for matching digits in subject
2632     strings against \d.
2634     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2635     ending in _t are). So I've renamed it as ESC_tee.
2637     3. The first argument for regexec() in the POSIX wrapper should have been
2638     defined as "const".
2640     4. Changed pcretest to use malloc() for its buffers so that they can be
2641     Electric Fenced for debugging.
2643     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2644     to read one or more bytes before the start of the subject string. Often this
2645     had no effect on PCRE's behaviour, but in some circumstances it could
2646     provoke a segmentation fault.
2648     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2649     to try to read one or more bytes before the start of the subject string.
2651     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2652     UTF-8 support could misbehave in various ways if the subject string
2653     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2654     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2655     back over UTF-8 characters.)
2658 nigel 67 Version 4.2 14-Apr-03
2659     ---------------------
2661     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2663     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2664     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2665     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2666     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2667     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2668     and BUILD_EXEEXT
2669     Note: automatic setting of the BUILD variables is not yet working
2670     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2671     compile-time but not at link-time
2672     [LINK]: use for linking executables only
2673     make different versions for Windows and non-Windows
2674     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2675     libraries
2676     [LINK_FOR_BUILD]: new variable
2677     [OBJEXT]: use throughout
2678     [EXEEXT]: use throughout
2679     <winshared>: new target
2680     <wininstall>: new target
2681     <dftables.o>: use native compiler
2682     <dftables>: use native linker
2683     <install>: handle Windows platform correctly
2684     <clean>: ditto
2685     <check>: ditto
2686     copy DLL to top builddir before testing
2688     As part of these changes, -no-undefined was removed again. This was reported
2689     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2690     in any case.
2692     3. Some tidies to get rid of compiler warnings:
2694     . In the match_data structure, match_limit was an unsigned long int, whereas
2695     match_call_count was an int. I've made them both unsigned long ints.
2697     . In pcretest the fact that a const uschar * doesn't automatically cast to
2698     a void * provoked a warning.
2700     . Turning on some more compiler warnings threw up some "shadow" variables
2701     and a few more missing casts.
2703     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2704     option, a class that contained a single character with a value between 128
2705     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2707     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2708     option, a class that contained several characters, but with at least one
2709     whose value was between 128 and 255 caused PCRE to crash.
2712 nigel 65 Version 4.1 12-Mar-03
2713     ---------------------
2714 nigel 63
2715 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2716     needed, and a string in dftables.c that was longer than standard compilers are
2717     required to support.
2719     2. Compiling with Sun's compiler found a few more places where the code could
2720     be tidied up in order to avoid warnings.
2722     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2723     first of these names is deprecated in the latest Autoconf in favour of the name
2724     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2725     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2726     analogy I have changed it to CFLAGS_FOR_BUILD.
2728     4. Added -no-undefined to the linking command in the Makefile, because this is
2729     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2730     linking step for the pcreposix library.
2732     5. PCRE was failing to diagnose the case of two named groups with the same
2733     name.
2735     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2736     literal character that is needed in the subject for a match, and scans along to
2737     ensure that it is present before embarking on the full matching process. This
2738     saves time in cases of nested unlimited repeats that are never going to match.
2739     Problem: the scan can take a lot of time if the subject is very long (e.g.
2740     megabytes), thus penalizing straightforward matches. It is now done only if the
2741     amount of subject to be scanned is less than 1000 bytes.
2743     7. A lesser problem with the same optimization is that it was recording the
2744     first character of an anchored pattern as "needed", thus provoking a search
2745     right along the subject, even when the first match of the pattern was going to
2746     fail. The "needed" character is now not set for anchored patterns, unless it
2747     follows something in the pattern that is of non-fixed length. Thus, it still
2748     fulfils its original purpose of finding quick non-matches in cases of nested
2749     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2752     Version 4.0 17-Feb-03
2753     ---------------------
2755 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2756     extended to the end of string, PCRE compiled incorrect data. This could lead to
2757     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2759     2. Moved to autoconf 2.53 and libtool 1.4.2.
2761     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2762     the special perltest8 script is no longer needed - all the tests can be run
2763     from a single perltest script.
2765     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2766     by \s. It has now been removed in PCRE. This means it isn't recognized as
2767     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2768     class [:space:] *does* include VT, thereby creating a mess.
2770     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2771     space and tab.
2773     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2774     its new features into the main test script, reducing the number of scripts.
2776     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2777     were backward compatible, and made the (?i) apply to the whole pattern, as if
2778     /i were given. Now it behaves more logically, and applies the option setting
2779     only to what follows. PCRE has been changed to follow suit. However, if it
2780     finds options settings right at the start of the pattern, it extracts them into
2781     the global options, as before. Thus, they show up in the info data.
2783     8. Added support for the \Q...\E escape sequence. Characters in between are
2784     treated as literals. This is slightly different from Perl in that $ and @ are
2785     also handled as literals inside the quotes. In Perl, they will cause variable
2786     interpolation. Note the following examples:
2788     Pattern PCRE matches Perl matches
2790     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2791     \Qabc\$xyz\E abc\$xyz abc\$xyz
2792     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2794     For compatibility with Perl, \Q...\E sequences are recognized inside character
2795     classes as well as outside them.
2797     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2798     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2799     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2800     signed/unsigned warnings.
2802     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2803     option for pcretest, so I've replaced it by a simple function that does just
2804     that job.
2806     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2807     "pcregrep -".
2809     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2810     Java package. This provides some syntactic sugar for simple cases of what my
2811     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2812     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2813     item, you can use this simplified notation. Note that only makes sense with
2814     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2815     greediness, whatever the setting of the PCRE_UNGREEDY option.
2817     13. A change of greediness default within a pattern was not taking effect at
2818     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2819     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2820     was abstracted outside.
2822     14. PCRE now supports the \G assertion. It is true when the current matching
2823     position is at the start point of the match. This differs from \A when the
2824     starting offset is non-zero. Used with the /g option of pcretest (or similar
2825     code), it works in the same way as it does for Perl's /g option. If all
2826     alternatives of a regex begin with \G, the expression is anchored to the start
2827     match position, and the "anchored" flag is set in the compiled expression.
2829     15. Some bugs concerning the handling of certain option changes within patterns
2830     have been fixed. These applied to options other than (?ims). For example,
2831     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2832     been the other way round. Some of this was related to change 7 above.
2834     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2835     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2836     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2837     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2839     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2840     mode. Unlike ".", it always matches newline, whatever the setting of
2841     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2842     assertions. Perl allows it, but it doesn't (in general) work because it can't
2843     calculate the length of the lookbehind. At least, that's the case for Perl
2844     5.8.0 - I've been told they are going to document that it doesn't work in
2845     future.
2847     18. Added an error diagnosis for escapes that PCRE does not support: these are
2848     \L, \l, \N, \P, \p, \U, \u, and \X.
2850     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2851     reading past the end of the pattern in cases such as /[abcd/.
2853     20. PCRE was getting more memory than necessary for patterns with classes that
2854     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2856     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2857     compiling PCRE for use with Virtual Pascal.
2859     22. Small fix to the Makefile to make it work properly if the build is done
2860     outside the source tree.
2862     23. Added a new extension: a condition to go with recursion. If a conditional
2863     subpattern starts with (?(R) the "true" branch is used if recursion has
2864     happened, whereas the "false" branch is used only at the top level.
2866     24. When there was a very long string of literal characters (over 255 bytes
2867     without UTF support, over 250 bytes with UTF support), the computation of how
2868     much memory was required could be incorrect, leading to segfaults or other
2869     strange effects.
2871     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2872     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2873     there was a subsequent back reference to those brackets. This meant that, for
2874     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2875     possible to check for precisely this case. All we can do is abandon the
2876     optimization if .* occurs inside capturing brackets when there are any back
2877     references whatsoever. (See below for a better fix that came later.)
2879     26. The handling of the optimization for finding the first character of a
2880     non-anchored pattern, and for finding a character that is required later in the
2881     match were failing in some cases. This didn't break the matching; it just
2882     failed to optimize when it could. The way this is done has been re-implemented.
2884     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2886     28. Added a new feature that provides some of the functionality that Perl
2887     provides with (?{...}). The facility is termed a "callout". The way it is done
2888     in PCRE is for the caller to provide an optional function, by setting
2889     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2890     global variable. By default it is unset, which disables all calling out. To get
2891     the function called, the regex must include (?C) at appropriate points. This
2892     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2893     This provides a means of identifying different callout points. When PCRE
2894     reaches such a point in the regex, if pcre_callout has been set, the external
2895     function is called. It is provided with data in a structure called
2896     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2897     matching continues; if it returns a non-zero value, the match at the current
2898     point fails. However, backtracking will occur if possible. [This was changed
2899     later and other features added - see item 49 below.]
2901     29. pcretest is upgraded to test the callout functionality. It provides a
2902     callout function that displays information. By default, it shows the start of
2903     the match and the current position in the text. There are some new data escapes
2904     to vary what happens:
2906     \C+ in addition, show current contents of captured substrings
2907     \C- do not supply a callout function
2908     \C!n return 1 when callout number n is reached
2909     \C!n!m return 1 when callout number n is reached for the mth time
2911     30. If pcregrep was called with the -l option and just a single file name, it
2912     output "<stdin>" if a match was found, instead of the file name.
2914     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2915     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2916     pcre_exec(). This saves a malloc/free per call. The default value of
2917     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2918     when configuring.
2920     32. The default maximum size of a compiled pattern is 64K. There have been a
2921     few cases of people hitting this limit. The code now uses macros to handle the
2922     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2923     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2924     configuring. Tests 2 and 5 work only with 2-byte links because they output
2925     debugging information about compiled patterns.
2927     33. Internal code re-arrangements:
2929     (a) Moved the debugging function for printing out a compiled regex into
2930     its own source file (printint.c) and used #include to pull it into
2931     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2932     separate copies.
2934     (b) Defined the list of op-code names for debugging as a macro in
2935     internal.h so that it is next to the definition of the opcodes.
2937     (c) Defined a table of op-code lengths for simpler skipping along compiled
2938     code. This is again a macro in internal.h so that it is next to the
2939     definition of the opcodes.
2941     34. Added support for recursive calls to individual subpatterns, along the
2942     lines of Robin Houston's patch (but implemented somewhat differently).
2944     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2945     allow it to read and process whole directories in Win32. This code was
2946     contributed by Lionel Fourquaux; it has not been tested by me.
2948     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2949     used to name a group. Names consist of alphanumerics and underscores, and must
2950     be unique. Back references use the syntax (?P=name) and recursive calls use
2951     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2952     numbers. The function pcre_fullinfo() can be used after compilation to extract
2953     a name/number map. There are three relevant calls:
2955     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2956     PCRE_INFO_NAMECOUNT yields the number of entries
2957     PCRE_INFO_NAMETABLE yields a pointer to the map.
2959     The map is a vector of fixed-size entries. The size of each entry depends on
2960     the length of the longest name used. The first two bytes of each entry are the
2961     group number, most significant byte first. There follows the corresponding
2962     name, zero terminated. The names are in alphabetical order.
2964     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2965     case instead of 255. Making it the same both with and without UTF-8 support
2966     means that the same test output works with both.
2968     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2969     calling malloc() with a zero argument.
2971     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2972     optimization. I've improved things by keeping a bitmap of backreferences with
2973     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2974     fact referenced, the optimization can be applied. It is unlikely that a
2975     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2976     the match to follow \n) will appear inside brackets with a number greater than
2977     31, but if it does, any back reference > 31 suppresses the optimization.
2979     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2980     of disabling numbered capturing parentheses. Any opening parenthesis that is
2981     not followed by ? behaves as if it were followed by ?: but named parentheses
2982     can still be used for capturing (and they will acquire numbers in the usual
2983     way).
2985     41. Redesigned the return codes from the match() function into yes/no/error so
2986     that errors can be passed back from deep inside the nested calls. A malloc
2987     failure while inside a recursive subpattern call now causes the
2988     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2990     42. It is now possible to set a limit on the number of times the match()
2991     function is called in a call to pcre_exec(). This facility makes it possible to
2992     limit the amount of recursion and backtracking, though not in a directly
2993     obvious way, because the match() function is used in a number of different
2994     circumstances. The count starts from zero for each position in the subject
2995     string (for non-anchored patterns). The default limit is, for compatibility, a
2996     large number, namely 10 000 000. You can change this in two ways:
2998     (a) When configuring PCRE before making, you can use --with-match-limit=n
2999     to set a default value for the compiled library.
3001     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3002     a different value is set. See 45 below.
3004     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3006     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3007     of things that can be changed at compile time. The first argument specifies
3008     what is wanted and the second points to where the information is to be placed.
3009     The current list of available information is:
3013     The output is an integer that is set to one if UTF-8 support is available;
3014     otherwise it is set to zero.
3018     The output is an integer that it set to the value of the code that is used for
3019     newline. It is either LF (10) or CR (13).
3023     The output is an integer that contains the number of bytes used for internal
3024     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3028     The output is an integer that contains the threshold above which the POSIX
3029     interface uses malloc() for output vectors. See item 31 above.
3033     The output is an unsigned integer that contains the default limit of the number
3034     of match() calls in a pcre_exec() execution. See 42 above.
3036     44. pcretest has been upgraded by the addition of the -C option. This causes it
3037     to extract all the available output from the new pcre_config() function, and to
3038     output it. The program then exits immediately.
3040     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3041     order to support additional features. One way would have been to define
3042     pcre_exec2() (for example) with extra arguments, but this would not have been
3043     extensible, and would also have required all calls to the original function to
3044     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3045     is used for passing in "extra" data from pcre_study().
3047     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3048     contains the following fields:
3050     flags a bitmap indicating which of the following fields are set
3051     study_data opaque data from pcre_study()
3052     match_limit a way of specifying a limit on match() calls for a specific
3053     call to pcre_exec()
3054     callout_data data for callouts (see 49 below)
3056     The flag bits are also defined in pcre.h, and are
3062     The pcre_study() function now returns one of these new pcre_extra blocks, with
3063     the actual study data pointed to by the study_data field, and the
3064     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3065     before. That is, this change is entirely upwards-compatible and requires no
3066     change to existing code.
3068     If you want to pass in additional data to pcre_exec(), you can either place it
3069     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3070     block.
3072     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3073     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3074     times with different match limits, until it finds the minimum value needed for
3075     pcre_exec() to complete. The value is then output. This can be instructive; for
3076     most simple matches the number is quite small, but for pathological cases it
3077     gets very large very quickly.
3079     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3080     returns the size of the data block pointed to by the study_data field in a
3081     pcre_extra block, that is, the value that was passed as the argument to
3082     pcre_malloc() when PCRE was getting memory in which to place the information
3083     created by pcre_study(). The fourth argument should point to a size_t variable.
3084     pcretest has been extended so that this information is shown after a successful
3085     pcre_study() call when information about the compiled regex is being displayed.
3087     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3088     because what follows is always an absolute path. (Later: it turns out that this
3089     is more than cosmetic for MinGW, because it doesn't like empty path
3090     components.)
3092     49. Some changes have been made to the callout feature (see 28 above):
3094     (i) A callout function now has three choices for what it returns:
3096     0 => success, carry on matching
3097     > 0 => failure at this point, but backtrack if possible
3098     < 0 => serious error, return this value from pcre_exec()
3100     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3101     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3102     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3103     use by callout functions. It will never be used by PCRE itself.
3105     (ii) The pcre_extra structure (see 45 above) has a void * field called
3106     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3107     pcre_callout_block structure has a field of the same name. The contents of
3108     the field passed in the pcre_extra structure are passed to the callout
3109     function in the corresponding field in the callout block. This makes it
3110     easier to use the same callout-containing regex from multiple threads. For
3111     testing, the pcretest program has a new data escape
3113     \C*n pass the number n (may be negative) as callout_data
3115     If the callout function in pcretest receives a non-zero value as
3116     callout_data, it returns that value.
3118     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3119     there were some redundant $(CFLAGS) in commands that are now specified as
3120     $(LINK), which already includes $(CFLAGS).
3122     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3123     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3124     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3125     one-byte characters throughout. Note that case-insensitive matching applies
3126     only to characters whose values are less than 256. PCRE doesn't support the
3127     notion of cases for higher-valued characters.
3129     (i) A character class whose characters are all within 0-255 is handled as
3130     a bit map, and the map is inverted for negative classes. Previously, a
3131     character > 255 always failed to match such a class; however it should
3132     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3134     (ii) A negated character class with a single character < 255 is coded as
3135     "not this character" (OP_NOT). This wasn't working properly when the test
3136     character was multibyte, either singly or repeated.
3138     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3139     mode, for example: \x{100}{2,3}.
3141     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3142     singly or repeated) now correctly test multibyte characters. However,
3143     PCRE doesn't recognize any characters with values greater than 255 as
3144     digits, spaces, or word characters. Such characters always match \D, \S,
3145     and \W, and never match \d, \s, or \w.
3147     (v) Classes may now contain characters and character ranges with values
3148     greater than 255. For example: [ab\x{100}-\x{400}].
3150     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3151     PCRE in UTF-8 mode.
3153     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3154     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3155     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3156     value.)
3158     53. The single man page has become too large. I have therefore split it up into
3159     a number of separate man pages. These also give rise to individual HTML pages;
3160     these are now put in a separate directory, and there is an index.html page that
3161     lists them all. Some hyperlinking between the pages has been installed.
3163     54. Added convenience functions for handling named capturing parentheses.
3165     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3166     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3167     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3168     are faulted.
3170     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3171     calling configure. These values are used when compiling the dftables.c program
3172     which is run to generate the source of the default character tables. They
3173     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3174     you will need to set these values.
3176     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3179     Version 3.9 02-Jan-02
3180 nigel 61 ---------------------
3182     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3184     2. If --disable-static was given, the building process failed when trying to
3185     build pcretest and pcregrep. (For some reason it was using libtool to compile
3186     them, which is not right, as they aren't part of the library.)
3189 nigel 59 Version 3.8 18-Dec-01
3190     ---------------------
3192     1. The experimental UTF-8 code was completely screwed up. It was packing the
3193     bytes in the wrong order. How dumb can you get?
3196 nigel 57 Version 3.7 29-Oct-01
3197     ---------------------
3199     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3200     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3201     this didn't happen under Solaris 8, where I normally test things.
3203 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3204     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3205     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3206     this fix an hour or so after the initial 3.7 release.)
3207 nigel 57
3208 nigel 59
3209 nigel 55 Version 3.6 23-Oct-01
3210     ---------------------
3212     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3213     offsets passed as NULL with zero offset count.
3215     2. The config.guess and config.sub files had not been updated when I moved to
3216     the latest autoconf.
3219 nigel 53 Version 3.5 15-Aug-01
3220     ---------------------
3221 nigel 5
3222 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3223     had been forgotten.
3225     2. By using declared but undefined structures, we can avoid using "void"
3226     definitions in pcre.h while keeping the internal definitions of the structures
3227     private.
3229     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3230     user point of view, this means that both static and shared libraries are built
3231     by default, but this can be individually controlled. More of the work of
3232     handling this static/shared cases is now inside libtool instead of PCRE's make
3233     file.
3235     4. The pcretest utility is now installed along with pcregrep because it is
3236     useful for users (to test regexs) and by doing this, it automatically gets
3237     relinked by libtool. The documentation has been turned into a man page, so
3238     there are now .1, .txt, and .html versions in /doc.
3240     5. Upgrades to pcregrep:
3241     (i) Added long-form option names like gnu grep.
3242     (ii) Added --help to list all options with an explanatory phrase.
3243     (iii) Added -r, --recursive to recurse into sub-directories.
3244     (iv) Added -f, --file to read patterns from a file.
3246     6. pcre_exec() was referring to its "code" argument before testing that
3247     argument for NULL (and giving an error if it was NULL).
3249     7. Upgraded Makefile.in to allow for compiling in a different directory from
3250     the source directory.
3252     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3253     options bits, the pointer it was passed was to an int instead of to an unsigned
3254     long int. This mattered only on 64-bit systems.
3256     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3257     generated) instead of pcre.in, which it its source. Also made the same change
3258     in several of the .c files.
3260     10. A new release of gcc defines printf() as a macro, which broke pcretest
3261     because it had an ifdef in the middle of a string argument for printf(). Fixed
3262     by using separate calls to printf().
3264     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3265     script, to force use of CR or LF instead of \n in the source. On non-Unix
3266     systems, the value can be set in config.h.
3268     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3269     absolute limit. Changed the text of the error message to make this clear, and
3270     likewise updated the man page.
3272     13. The limit of 99 on the number of capturing subpatterns has been removed.
3273     The new limit is 65535, which I hope will not be a "real" limit.
3276 nigel 51 Version 3.4 22-Aug-00
3277     ---------------------
3279     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3281     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3284 nigel 49 Version 3.3 01-Aug-00
3285     ---------------------
3287     1. If an octal character was given, but the value was greater than \377, it
3288     was not getting masked to the least significant bits, as documented. This could
3289     lead to crashes in some systems.
3291     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3292     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3294     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3295     These just pass their arguments on to (pcre_free)(), but they are provided
3296     because some uses of PCRE bind it to non-C systems that can call its functions,
3297     but cannot call free() or pcre_free() directly.
3299     4. Add "make test" as a synonym for "make check". Corrected some comments in
3300     the Makefile.
3302     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3303     Makefile.
3305     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3306     command called pgrep for grepping around the active processes.
3308     7. Added the beginnings of support for UTF-8 character strings.
3310     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3311     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3312     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3313     out for the ar command.)
3316 nigel 47 Version 3.2 12-May-00
3317     ---------------------
3319     This is purely a bug fixing release.
3321     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3322     of ZA. This was just one example of several cases that could provoke this bug,
3323     which was introduced by change 9 of version 2.00. The code for breaking
3324     infinite loops after an iteration that matches an empty string was't working
3325     correctly.
3327     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3328     when matched against abbab (for example). After matching an empty string, it
3329     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3330     caused it to match further down the string than it should.
3332     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3333     was there because it doesn't seem to be needed, and it causes trouble on some
3334     systems, as it is not a Standard C header. It has been removed.
3336     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3337     were reported on the Macintosh. The changes were from
3339     while ((c = *(++ptr)) != 0 && c != '\n');
3340     to
3341     while ((c = *(++ptr)) != 0 && c != '\n') ;
3343     Totally extraordinary, but if that's what it takes...
3345     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3346     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3347     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3348     assumes the way PCRE uses memmove() (always moving upwards).
3350     6. PCRE is being used in one environment where strchr() is not available. There
3351     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3352     faster code anyway.
3355 nigel 45 Version 3.1 09-Feb-00
3356     ---------------------
3358     The only change in this release is the fixing of some bugs in Makefile.in for
3359     the "install" target:
3361     (1) It was failing to install pcreposix.h.
3363     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3366 nigel 43 Version 3.0 01-Feb-00
3367     ---------------------
3368 nigel 41
3369     1. Add support for the /+ modifier to perltest (to output $` like it does in
3370     pcretest).
3372     2. Add support for the /g modifier to perltest.
3374     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3375     matches null strings.
3377     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3378     pattern. Perl treats empty patterns specially - it reuses the most recent
3379     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3380     effect.
3382     5. The POSIX interface was broken in that it was just handing over the POSIX
3383     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3384     required a bigger vector, with some working space on the end. This means that
3385     the POSIX wrapper now has to get and free some memory, and copy the results.
3387 nigel 43 6. Added some simple autoconf support, placing the test data and the
3388     documentation in separate directories, re-organizing some of the
3389     information files, and making it build pcre-config (a GNU standard). Also added
3390     libtool support for building PCRE as a shared library, which is now the
3391     default.
3392 nigel 41
3393 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3394     09 are not valid octal constants. Single digits will be used for minor values
3395     less than 10.
3397     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3398     existing programs that set these in the POSIX interface can use PCRE without
3399     modification.
3401     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3402     return all that pcre_info() returns, plus additional data. The pcre_info()
3403     function is retained for compatibility, but is considered to be obsolete.
3405     10. Added experimental recursion feature (?R) to handle one common case that
3406     Perl 5.6 will be able to do with (?p{...}).
3408     11. Added support for POSIX character classes like [:alpha:], which Perl is
3409     adopting.
3412 nigel 39 Version 2.08 31-Aug-99
3413     ----------------------
3415     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3416     trying to match at the startoffset position, but instead was moving forward to
3417     the next newline as if a previous match had failed.
3419     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3420     and could get into a loop if a null string was matched other than at the start
3421     of the subject.
3423     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3424     be distinguished at compile time, and for completeness also added PCRE_DATE.
3426     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3427     in GnuWin32 environments.
3430 nigel 37 Version 2.07 29-Jul-99
3431     ----------------------
3433     1. The documentation is now supplied in plain text form and HTML as well as in
3434     the form of man page sources.
3436     2. C++ compilers don't like assigning (void *) values to other pointer types.
3437     In particular this affects malloc(). Although there is no problem in Standard
3438     C, I've put in casts to keep C++ compilers happy.
3440     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3441     should be (const char *).
3443     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3444     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3445     However, I haven't made this a standard facility. The documentation doesn't
3446     mention it, and the Makefile doesn't support it.
3448     5. The Makefile now contains an "install" target, with editable destinations at
3449     the top of the file. The pcretest program is not installed.
3451     6. pgrep -V now gives the PCRE version number and date.
3453     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3454     causing the entire string to be ignored, instead of just the last character.
3456     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3457     non-matching string, it can take a very, very long time, even for strings of
3458     quite modest length, because of the nested recursion. PCRE now does better in
3459     some of these cases. It does this by remembering the last required literal
3460     character in the pattern, and pre-searching the subject to ensure it is present
3461     before running the real match. In other words, it applies a heuristic to detect
3462     some types of certain failure quickly, and in the above example, if presented
3463     with a string that has no trailing " it gives "no match" very quickly.
3465     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3466     other alternatives are tried instead.
3469 nigel 35 Version 2.06 09-Jun-99
3470     ----------------------
3472     1. Change pcretest's output for amount of store used to show just the code
3473     space, because the remainder (the data block) varies in size between 32-bit and
3474     64-bit systems.
3476     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3477     start matching at. This allows lookbehinds to work when searching for multiple
3478     occurrences in a string.
3480     3. Added additional options to pcretest for testing multiple occurrences:
3482     /+ outputs the rest of the string that follows a match
3483     /g loops for multiple occurrences, using the new startoffset argument
3484     /G loops for multiple occurrences by passing an incremented pointer
3486     4. PCRE wasn't doing the "first character" optimization for patterns starting
3487     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3488     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3489     the letter 'x'. On long subject strings, this gives a significant speed-up.
3492 nigel 33 Version 2.05 21-Apr-99
3493     ----------------------
3495     1. Changed the type of magic_number from int to long int so that it works
3496     properly on 16-bit systems.
3498     2. Fixed a bug which caused patterns starting with .* not to work correctly
3499     when the subject string contained newline characters. PCRE was assuming
3500     anchoring for such patterns in all cases, which is not correct because .* will
3501     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3502     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3503     must be retried after every newline in the subject.
3506 nigel 31 Version 2.04 18-Feb-99
3507     ----------------------
3509     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3510     computation of the store needed to hold the pattern was incorrect (too large).
3511     If such patterns were nested a few deep, this could multiply and become a real
3512     problem.
3514     2. Added /M option to pcretest to show the memory requirement of a specific
3515     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3517     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3518     compiled in such a way that the backtracking after subsequent failure was
3519     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3520     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3523 nigel 29 Version 2.03 02-Feb-99
3524     ----------------------
3526     1. Fixed typo and small mistake in man page.
3528 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3529     LICENCE file containing the conditions.
3530 nigel 29
3531     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3532     Perl, that is the internal \ allows the delimiter to be included in the
3533     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3534     the final delimiter, add \ to the end of the pattern (to test the error).
3536     4. Added the convenience functions for extracting substrings after a successful
3537     match. Updated pcretest to make it able to test these functions.
3540 nigel 27 Version 2.02 14-Jan-99
3541     ----------------------
3543     1. Initialized the working variables associated with each extraction so that
3544     their saving and restoring doesn't refer to uninitialized store.
3546     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3547     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3548     fix the problem.
3550     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3551     calls, and wasn't printing the correct value for compiling calls. Increased the
3552     default value of LOOPREPEAT, and the number of significant figures in the
3553     times.
3555     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3557     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3558     a building problem on Windows NT with a FAT file system.
3561 nigel 25 Version 2.01 21-Oct-98
3562     ----------------------
3564     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3565     to character tables built by pcre_maketables() in the current locale. If NULL
3566     is passed, the default tables are used.
3569 nigel 23 Version 2.00 24-Sep-98
3570 nigel 21 ----------------------
3572 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3573     it any more.
3575     2. Allow quantification of (?>) groups, and make it work correctly.
3577     3. The first character computation wasn't working for (?>) groups.
3579     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3580     end of the subject) and add 5.005's \z, which really does match only at the
3581     very end of the subject.
3583     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3585     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3586     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3587     localized options. All options to pcre_study() were also removed.
3589     7. Add other new features from 5.005:
3591     $(?<= positive lookbehind
3592     $(?<! negative lookbehind
3593     (?imsx-imsx) added the unsetting capability
3594     such a setting is global if at outer level; local otherwise
3595     (?imsx-imsx:) non-capturing groups with option setting
3596     (?(cond)re|re) conditional pattern matching
3598     A backreference to itself in a repeated group matches the previous
3599     captured string.
3601     8. General tidying up of studying (both automatic and via "study")
3602     consequential on the addition of new assertions.
3604     9. As in 5.005, unlimited repeated groups that could match an empty substring
3605     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3606     runtime if any iteration does actually match an empty substring.
3608     10. Include the RunTest script in the distribution.
3610     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3611     discrepancies, some of which were old and were also with respect to 5.004. They
3612     have now been fixed.
3615     Version 1.09 28-Apr-98
3616     ----------------------
3618 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3619     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3620     program crashes, or just wrong answers. This did not apply to negated classes
3621     containing more than one character, or to minima other than one.
3624 nigel 19 Version 1.08 27-Mar-98
3625     ----------------------
3627     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3629     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3630     latter must appear before anything that relies on it in the pattern.
3633 nigel 17 Version 1.07 16-Feb-98
3634     ----------------------
3636     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3637     repeat of a potentially empty string).
3640 nigel 15 Version 1.06 23-Jan-98
3641     ----------------------
3643     1. Added Markus Oberhumer's little patches for C++.
3645     2. Literal strings longer than 255 characters were broken.
3648 nigel 13 Version 1.05 23-Dec-97
3649     ----------------------
3651     1. Negated character classes containing more than one character were failing if
3652     PCRE_CASELESS was set at run time.
3655 nigel 11 Version 1.04 19-Dec-97
3656     ----------------------
3658     1. Corrected the man page, where some "const" qualifiers had been omitted.
3660     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3661     input syntax.
3663     3. Fixed memory leak which occurred when a regex with back references was
3664     matched with an offsets vector that wasn't big enough. The temporary memory
3665     that is used in this case wasn't being freed if the match failed.
3667     4. Tidied pcretest to ensure it frees memory that it gets.
3669     5. Temporary memory was being obtained in the case where the passed offsets
3670     vector was exactly big enough.
3672     6. Corrected definition of offsetof() from change 5 below.
3674     7. I had screwed up change 6 below and broken the rules for the use of
3675     setjmp(). Now fixed.
3678 nigel 9 Version 1.03 18-Dec-97
3679     ----------------------
3681     1. A erroneous regex with a missing opening parenthesis was correctly
3682     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3683     on some systems.
3685     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3686     it was reported that one broken compiler failed on the former because "code" is
3687     also an independent variable.
3689     3. The erroneous regex a[]b caused an array overrun reference.
3691     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3692     fail on data ending with that character. (It was going on too far, and checking
3693     the next character, typically a binary zero.) This was specific to the
3694     optimized code for single-character negative classes.
3696     5. Added a contributed patch from the TIN world which does the following:
3698     + Add an undef for memmove, in case the the system defines a macro for it.
3700     + Add a definition of offsetof(), in case there isn't one. (I don't know
3701     the reason behind this - offsetof() is part of the ANSI standard - but
3702     it does no harm).
3704     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3705     most of the places where whitespace preceded '#'. I have given up and
3706     allowed the remaining 2 cases to be at the margin.
3708     + Rename some variables in pcre to eliminate shadowing. This seems very
3709     pedantic, but does no harm, of course.
3711     6. Moved the call to setjmp() into its own function, to get rid of warnings
3712     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3714     7. Constructs such as \d{8,} were compiling into the equivalent of
3715 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3716 nigel 9 outcome, but in this particular case used more store than had been allocated,
3717     which caused the bug to be discovered because it threw up an internal error.
3719     8. The debugging code in both pcre and pcretest for outputting the compiled
3720     form of a regex was going wrong in the case of back references followed by
3721     curly-bracketed repeats.
3724 nigel 7 Version 1.02 12-Dec-97
3725     ----------------------
3727     1. Typos in pcre.3 and comments in the source fixed.
3729     2. Applied a contributed patch to get rid of places where it used to remove
3730     'const' from variables, and fixed some signed/unsigned and uninitialized
3731     variable warnings.
3733     3. Added the "runtest" target to Makefile.
3735     4. Set default compiler flag to -O2 rather than just -O.
3738 nigel 5 Version 1.01 19-Nov-97
3739     ----------------------
3741     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3742     like /([ab]*)*/, that is, for classes with more than one character in them.<