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Revision 537 - (hide annotations) (download)
Tue Jun 8 15:28:26 2010 UTC (4 years, 3 months ago) by ph10
File size: 188117 byte(s)
Add newline in pcretest output if the last data line doesn't have one.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 535 Version 8.10 03-Jun-2010
5 ph10 510 ------------------------
6    
7 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8 ph10 510 THEN.
9    
10 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
11 ph10 510
12 ph10 535 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 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
15 ph10 535
16     4. Inside a character class, PCRE always treated \R and \X as literals,
17 ph10 513 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 535
20 ph10 514 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 535
23 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
24 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
26 ph10 535 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 512
29 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
30    
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).
34 ph10 535
35 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
37 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
38     REG_UCP to make it available via the POSIX interface.
39 ph10 513
40 ph10 535 10. Added --line-buffered to pcregrep.
41    
42     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 ph10 520 127 whose first byte was different to the first byte of the other case of
45 ph10 536 the letter, the other case of this starting letter was not recognized
46     (#976).
47 ph10 535
48 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
49 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
50 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
51     not have actually happened in practice until change 8 above was made (it
52 ph10 523 added property types that matched character-matching opcodes).
53 ph10 535
54 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
55 ph10 535 possible starting bytes for non-anchored patterns.
56    
57 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
58 ph10 535 \R, and also a number of cases that involve Unicode properties, both
59 ph10 532 explicit and implicit when PCRE_UCP is set.
60 ph10 529
61 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
62 ph10 535 input, it could crash or give wrong results if characters with values
63     greater than 0xc0 were present in the subject string. (Detail: it assumed
64 ph10 529 UTF-8 input when processing these items.)
65 ph10 535
66 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
67     size_t is 64-bit (#991).
68 ph10 535
69 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
70     --disable-stack-for-recursion (#990).
71    
72 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
73     the end, a newline was missing in the output.
74    
75 ph10 517
76 ph10 520
77 ph10 508 Version 8.02 19-Mar-2010
78 ph10 491 ------------------------
79    
80     1. The Unicode data tables have been updated to Unicode 5.2.0.
81    
82 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
83     configured.
84 ph10 507
85 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
86 ph10 507 original author of that file, following a query about its status.
87    
88     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
89 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
90 ph10 507
91 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
92     quantifier applied to a forward-referencing subroutine call, could compile
93     incorrect code or give the error "internal error: previously-checked
94     referenced subpattern not found".
95 ph10 507
96     6. Both MS Visual Studio and Symbian OS have problems with initializing
97 ph10 497 variables to point to external functions. For these systems, therefore,
98     pcre_malloc etc. are now initialized to local functions that call the
99     relevant global functions.
100 ph10 507
101 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
102     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
103 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
104     the lengths are correct (equal to the number of opcodes).
105    
106     8. Following on from 7, I added a similar kludge to check the length of the
107     eint vector in pcreposix.c.
108    
109     9. Error texts for pcre_compile() are held as one long string to avoid too
110     much relocation at load time. To find a text, the string is searched,
111 ph10 499 counting zeros. There was no check for running off the end of the string,
112     which could happen if a new error number was added without updating the
113 ph10 507 string.
114    
115     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
116    
117 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
118 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
119     \K is "not well defined" if used in an assertion. PCRE now accepts it if
120     the assertion is positive, but not if it is negative.
121    
122 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
123 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
124     implementation of support for (*MARK) will need an extra pointer on the
125 ph10 501 stack; I have reserved it now, so that the stack frame size does not
126     decrease.
127 ph10 507
128     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
129     item in branch that calls a recursion is a subroutine call - as in the
130 ph10 503 second branch in the above example - was incorrectly given the compile-
131     time error "recursive call could loop indefinitely" because pcre_compile()
132 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
133    
134 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
135 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
136 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
137 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
138 ph10 491
139 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
140 ph10 492
141 ph10 507
142 ph10 489 Version 8.01 19-Jan-2010
143     ------------------------
144 ph10 471
145     1. If a pattern contained a conditional subpattern with only one branch (in
146 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
147 ph10 473 computed the wrong minimum data length (which is of course zero for such
148 ph10 489 subpatterns). This could cause incorrect "no match" results.
149 ph10 473
150     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
151 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
152     "internal error: code overflow at offset...". This happened only when
153 ph10 473 the reset was to the original external option setting. (An optimization
154     abstracts leading options settings into an external setting, which was the
155 ph10 472 cause of this.)
156 ph10 471
157 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
158     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
159     assertion pattern did not match (meaning that the assertion was true), it
160     was incorrectly treated as false if the SKIP had been reached during the
161     matching. This also applied to assertions used as conditions.
162 ph10 471
163 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
164     assertion subpattern, including such a pattern used as a condition,
165     unpredictable results occurred, instead of the error return
166     PCRE_ERROR_DFA_UITEM.
167 ph10 478
168 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
169     situation when an empty string is matched. It now does the fancy magic
170 ph10 478 stuff that is necessary.
171    
172     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
173 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
174 ph10 478
175 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
176     as part of something else:
177 ph10 478
178     (a) Change DEBUG to PCRE_DEBUG.
179    
180     (b) In pcre_compile(), rename the member of the "branch_chain" structure
181     called "current" as "current_branch", to prevent a collision with the
182 ph10 475 Linux macro when compiled as a kernel module.
183 ph10 478
184     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
185     prevent a collision with the Linux macro when compiled as a kernel
186 ph10 475 module.
187 ph10 478
188 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
189     cast potentially large values to (double). This has been changed to that
190 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
191     instead, thus avoiding the use of floating point arithmetic. (There is no
192     other use of FP in PCRE.) If int64_t is not found, the fallback is to
193     double.
194    
195     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
196 ph10 476 2005 (difference between two addresses compared to an unsigned value).
197 ph10 473
198 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
199     custom one, because of the following reported problem in Windows:
200 ph10 473
201 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
202 ph10 489 under Win32.
203 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
204 ph10 489 therefore missing the function definition.
205 ph10 478 - The compiler thus generates a "C" signature for the test function.
206     - The linker fails to find the "C" function.
207     - PCRE fails to configure if asked to do so against libbz2.
208 ph10 486
209 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
210     messages were output:
211 ph10 478
212 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
213     rerunning libtoolize, to keep the correct libtool macros in-tree.
214     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
215 ph10 486
216 ph10 479 I have done both of these things.
217 ph10 486
218 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
219 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
220     runaway infinite recursion. I updated the discussion in the pcrestack man
221     page.
222    
223     13. Now that we have gone to the x.xx style of version numbers, the minor
224     version may start with zero. Using 08 or 09 is a bad idea because users
225     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
226     interpreted as invalid octal numbers. I've updated the previous comment in
227     configure.ac, and also added a check that gives an error if 08 or 09 are
228 ph10 481 used.
229 ph10 486
230 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
231 ph10 483 causing partial matching to fail when the end of the subject matched \W
232     in a UTF-8 pattern where \W was quantified with a minimum of 3.
233 ph10 486
234 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
235 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
236 ph10 483 their definitions. The declarations used "const uschar *" and the
237     definitions used USPTR. Even though USPTR is normally defined as "const
238     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
239     reported that: "This difference in casting confuses some C++ compilers, for
240     example, SunCC recognizes above declarations as different functions and
241 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
242 ph10 483 USPTR.
243 ph10 486
244     16. GNU libtool is named differently on some systems. The autogen.sh script now
245 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
246     (FreeBSD).
247 ph10 478
248 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
249     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
250     comment: "Figure out how to create a longlong from a string: strtoll and
251     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
252     instance, but it only takes 2 args instead of 3!"
253 ph10 479
254 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
255     specification, with a corresponding code fix. A pattern such as
256     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
257     refers, was giving matches when it shouldn't. For example, xa=xaaa would
258     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
259     same bug. Such groups have to be quantified to be useful, or contained
260     inside another quantified group. (If there's no repetition, the reference
261     can never match.) The problem arises because, having left the group and
262     moved on to the rest of the pattern, a later failure that backtracks into
263     the group uses the captured value from the final iteration of the group
264     rather than the correct earlier one. I have fixed this in PCRE by forcing
265     any group that contains a reference to itself to be an atomic group; that
266     is, there cannot be any backtracking into it once it has completed. This is
267     similar to recursive and subroutine calls.
268 ph10 486
269 ph10 488
270 ph10 469 Version 8.00 19-Oct-09
271 ph10 418 ----------------------
272    
273     1. The table for translating pcre_compile() error codes into POSIX error codes
274 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
275     being within the table. This could lead to an OK return being given in
276 ph10 418 error.
277 ph10 461
278     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
279     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
280     in a Windows environment.
281    
282 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
283     zero, as does GNU grep. However, pcregrep was also printing all files when
284     --files-with-matches was added. Now, when both options are given, it prints
285     counts only for those files that have at least one match. (GNU grep just
286 ph10 461 prints the file name in this circumstance, but including the count seems
287     more useful - otherwise, why use --count?) Also ensured that the
288 ph10 420 combination -clh just lists non-zero counts, with no names.
289 ph10 461
290     4. The long form of the pcregrep -F option was incorrectly implemented as
291     --fixed_strings instead of --fixed-strings. This is an incompatible change,
292     but it seems right to fix it, and I didn't think it was worth preserving
293     the old behaviour.
294    
295     5. The command line items --regex=pattern and --regexp=pattern were not
296 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
297 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
298 ph10 422 which are compatible with GNU grep; these now work.
299 ph10 461
300     6. No libpcreposix.pc file was created for pkg-config; there was just
301 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
302 ph10 461
303 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
304 ph10 461 when UCP support is not needed, by modifying the Python script that
305 ph10 425 generates it from Unicode data files. This should not matter if the module
306     is correctly used as a library, but I received one complaint about 50K of
307     unwanted data. My guess is that the person linked everything into his
308     program rather than using a library. Anyway, it does no harm.
309 ph10 461
310 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
311 ph10 461 was a minimum greater than 1 for a wide character in a possessive
312 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
313     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
314     character. Chaos in the form of incorrect output or a compiling loop could
315     result.
316 ph10 461
317 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
318 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
319 ph10 426 partially matched by this function. In addition, if there are at least two
320 ph10 435 slots in the offset vector, the offset of the earliest inspected character
321     for the match and the offset of the end of the subject are set in them when
322 ph10 461 PCRE_ERROR_PARTIAL is returned.
323    
324 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
325     synonymous with PCRE_PARTIAL, for backwards compatibility, and
326     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
327 ph10 462 and may be more useful for multi-segment matching.
328 ph10 461
329     11. Partial matching with pcre_exec() is now more intuitive. A partial match
330     used to be given if ever the end of the subject was reached; now it is
331     given only if matching could not proceed because another character was
332     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
333     string "Z", which now yields "no match" instead of "partial match". In the
334     case of pcre_dfa_exec(), "no match" is given if every matching path for the
335     final character ended with (*FAIL).
336    
337 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
338 ph10 461 if the pattern had a "must contain" character that was already found in the
339 ph10 428 earlier partial match, unless partial matching was again requested. For
340     example, with the pattern /dog.(body)?/, the "must contain" character is
341     "g". If the first part-match was for the string "dog", restarting with
342 ph10 435 "sbody" failed. This bug has been fixed.
343 ph10 461
344     13. The string returned by pcre_dfa_exec() after a partial match has been
345     changed so that it starts at the first inspected character rather than the
346     first character of the match. This makes a difference only if the pattern
347     starts with a lookbehind assertion or \b or \B (\K is not supported by
348     pcre_dfa_exec()). It's an incompatible change, but it makes the two
349 ph10 435 matching functions compatible, and I think it's the right thing to do.
350 ph10 461
351 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
352 ph10 461 so that the demonstration program is easily available in environments where
353     PCRE has not been installed from source.
354    
355 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
356 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
357     library.
358 ph10 461
359 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
360 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
361 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
362 ph10 433 these options useful.
363 ph10 461
364     17. If a caller to the POSIX matching function regexec() passes a non-zero
365 ph10 438 value for nmatch with a NULL value for pmatch, the value of
366 ph10 461 nmatch is forced to zero.
367    
368 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
369 ph10 461 the diff command, as RunTest does. It now checks in the same way as
370 ph10 437 RunTest, and also checks for the -b option.
371 ph10 461
372 ph10 438 19. If an odd number of negated classes containing just a single character
373     interposed, within parentheses, between a forward reference to a named
374 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
375     an internal error, complaining that it could not find the referenced
376 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
377 ph10 461 [The bug was that it was starting one character too far in when skipping
378     over the character class, thus treating the ] as data rather than
379     terminating the class. This meant it could skip too much.]
380    
381 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
382 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
383 ph10 442 to have an empty string match not at the start, even when the pattern is
384 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
385    
386 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
387 ph10 461 than the maximum at the outer level, the higher number was returned, but
388     with unset values at the outer level. The correct (outer level) value is
389 ph10 446 now given.
390 ph10 461
391 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
392     PCRE did not set those parentheses (unlike Perl). I have now found a way to
393     make it do so. The string so far is captured, making this feature
394     compatible with Perl.
395 ph10 461
396     23. The tests have been re-organized, adding tests 11 and 12, to make it
397 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
398 ph10 461
399 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
400 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
401     does. Neither allows recursion.
402    
403     25. I finally figured out how to implement a request to provide the minimum
404     length of subject string that was needed in order to match a given pattern.
405     (It was back references and recursion that I had previously got hung up
406     on.) This code has now been added to pcre_study(); it finds a lower bound
407 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
408     bound, but using it to avoid searching strings that are too short does give
409     some useful speed-ups. The value is available to calling programs via
410     pcre_fullinfo().
411 ph10 461
412 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
413     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
414     study optimizations had never been tested with that matching function.
415     Oops. What is worse, even when it was passed study data, there was a bug in
416     pcre_dfa_exec() that meant it never actually used it. Double oops. There
417     were also very few tests of studied patterns with pcre_dfa_exec().
418 ph10 461
419 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
420     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
421     on the other side of the coin, they are no longer allowed to have different
422     names, because these cannot be distinguished in PCRE, and this has caused
423     confusion. (This is a difference from Perl.)
424 ph10 461
425     28. When duplicate subpattern names are present (necessarily with different
426     numbers, as required by 27 above), and a test is made by name in a
427     conditional pattern, either for a subpattern having been matched, or for
428     recursion in such a pattern, all the associated numbered subpatterns are
429 ph10 459 tested, and the overall condition is true if the condition is true for any
430     one of them. This is the way Perl works, and is also more like the way
431     testing by number works.
432 ph10 418
433 ph10 461
434 ph10 412 Version 7.9 11-Apr-09
435 ph10 376 ---------------------
436    
437 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
438 ph10 376 (pcretest), all targets were linked against these libraries. This included
439     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
440     libraries. This caused unwanted dependencies to be created. This problem
441 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
442 ph10 376 pcretest is linked with readline.
443 ph10 392
444 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
445     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
446     moved outside it again, because FALSE and TRUE are already defined in AIX,
447     but BOOL is not.
448 ph10 392
449     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
450 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
451 ph10 392
452 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
453     hyphens) following file names and line numbers when outputting matching
454 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
455 ph10 376 wording for the --colour (or --color) option.
456 ph10 392
457 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
458     was not coloured; this is different to GNU grep, so I have changed it to be
459     the same.
460 ph10 392
461 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
462 ph10 392 each matching line was coloured. Now it goes on to look for further matches
463     of any of the test patterns, which is the same behaviour as GNU grep.
464    
465     7. A pattern that could match an empty string could cause pcregrep to loop; it
466     doesn't make sense to accept an empty string match in pcregrep, so I have
467 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
468     seems to be how GNU grep behaves.
469 ph10 392
470 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
471 ph10 392 start or after a newline", because the conditional assertion was not being
472     correctly handled. The rule now is that both the assertion and what follows
473     in the first alternative must satisfy the test.
474    
475 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
476 ph10 399 condition was an assertion, PCRE could crash during matching, both with
477     pcre_exec() and pcre_dfa_exec().
478 ph10 392
479     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
480     used for matching.
481    
482     11. Unicode property support in character classes was not working for
483 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
484 ph10 388
485 ph10 392 12. Added the -M command line option to pcretest.
486    
487 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
488 ph10 389
489     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
490 ph10 390
491 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
492 ph10 390 wrapper.
493 ph10 392
494 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
495 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
496 ph10 391 string constants.
497 ph10 405
498 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
499     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
500 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
501     these, but not everybody uses configure.
502    
503     19. A conditional group that had only one branch was not being correctly
504     recognized as an item that could match an empty string. This meant that an
505     enclosing group might also not be so recognized, causing infinite looping
506     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
507     with the subject "ab", where knowledge that the repeated group can match
508 ph10 396 nothing is needed in order to break the loop.
509 ph10 405
510 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
511 ph10 405 exec(), but without supplying a callout function, matching went wrong.
512    
513     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
514     leak if the size of the offset vector was greater than 30. When the vector
515     is smaller, the saved offsets during recursion go onto a local stack
516     vector, but for larger vectors malloc() is used. It was failing to free
517     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
518 ph10 400 error, in fact).
519 ph10 405
520 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
521 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
522     problem, but was untidy.
523 ph10 376
524 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
525     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
526     included within another project.
527 ph10 411
528 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
529     slightly modified by me:
530 ph10 411
531     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
532     not building pcregrep.
533    
534 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
535 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
536    
537 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
538     duplicate group numbers, could behave incorrectly or give incorrect errors,
539     because when scanning forward to find the reference group, PCRE was not
540     taking into account the duplicate group numbers. A pattern such as
541     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
542 ph10 411
543     26. Changed a few more instances of "const unsigned char *" to USPTR, making
544     the feature of a custom pointer more persuasive (as requested by a user).
545 ph10 416
546 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
547 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
548     pre-defined.
549 ph10 392
550 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
551    
552 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
553     in the configuration summary.
554 ph10 405
555 ph10 411
556 ph10 374 Version 7.8 05-Sep-08
557 ph10 349 ---------------------
558    
559     1. Replaced UCP searching code with optimized version as implemented for Ad
560     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
561 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
562     to 5 times on some simple patterns that I tested. Permission was given to
563     distribute the MultiStage2.py script that generates the tables (it's not in
564     the tarball, but is in the Subversion repository).
565 ph10 349
566 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
567     scripts.
568 ph10 358
569 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
570     a group with a zero qualifier. The result of the study could be incorrect,
571 ph10 358 or the function might crash, depending on the pattern.
572    
573     4. Caseless matching was not working for non-ASCII characters in back
574 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
575 ph10 358 It now works when Unicode Property Support is available.
576    
577 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
578     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
579     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
580 ph10 358 truncation.
581 ph10 349
582 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
583    
584 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
585     pointers, in case they are 64-bit values.
586 ph10 371
587     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
588     test 2 if it fails.
589    
590 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
591 ph10 371 and a #define of that name to empty if it is not externally set. This is to
592     allow users of MSVC to set it if necessary.
593    
594     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
595 ph10 359 the convenience functions in the pcre_get.c source file.
596 ph10 371
597 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
598     could cause overwriting and/or a crash. This command provoked a crash in
599 ph10 371 some environments:
600    
601     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
602    
603 ph10 360 This potential security problem was recorded as CVE-2008-2371.
604 ph10 371
605 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
606     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
607 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
608 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
609     pcretest so that it places the subject at the end of its malloc-ed buffer.
610 ph10 371
611 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
612 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
613    
614 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
615 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
616     first line. This applied both to normal and DFA matching.
617    
618 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
619 ph10 371 /^[^d]*?$/8 failed to match "abc".
620 ph10 351
621 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
622    
623     17. Make it more clear in the documentation that values returned from
624 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
625 ph10 357
626 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
627 ph10 368
628 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
629     supplied by Stefan Weber. I made a further small update for 7.8 because
630 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
631     replaced by pcre_ucd.c.
632 ph10 371
633 ph10 373
634 ph10 347 Version 7.7 07-May-08
635 ph10 321 ---------------------
636    
637     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
638 ph10 345 a string to a long long, pretend we don't even have a long long." This is
639 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
640 ph10 345
641 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
642     pre-7.6 versions, which defined a global no_arg variable instead of putting
643 ph10 332 it in the RE class. (See also #8 below.)
644 ph10 345
645     3. Remove a line of dead code, identified by coverity and reported by Nuno
646     Lopes.
647    
648 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
649 ph10 321
650 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
651 ph10 345 of files, instead of just to the final components.
652    
653 ph10 324 (2) If there was more than one level of directory, the subdirectories were
654     skipped unless they satisfied the include/exclude conditions. This is
655     inconsistent with GNU grep (and could even be seen as contrary to the
656     pcregrep specification - which I improved to make it absolutely clear).
657     The action now is always to scan all levels of directory, and just
658     apply the include/exclude patterns to regular files.
659 ph10 345
660 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
661 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
662    
663 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
664 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
665 ph10 326 doesn't support NULs in patterns.
666 ph10 345
667     7. Added some missing "const"s to declarations of static tables in
668     pcre_compile.c and pcre_dfa_exec.c.
669    
670 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
671 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
672 ph10 345 first patch. And a third patch - this was a messy problem.)
673 ph10 321
674 ph10 345 9. Applied Craig's patch to remove the use of push_back().
675    
676 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
677     matching function regexec().
678 ph10 345
679     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
680     which, however, unlike Perl's \g{...}, are subroutine calls, not back
681 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
682     Oniguruma does).
683 ph10 345
684     12. Previously, a group with a zero repeat such as (...){0} was completely
685 ph10 335 omitted from the compiled regex. However, this means that if the group
686     was called as a subroutine from elsewhere in the pattern, things went wrong
687 ph10 345 (an internal error was given). Such groups are now left in the compiled
688     pattern, with a new opcode that causes them to be skipped at execution
689 ph10 335 time.
690 ph10 345
691 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
692     to the way PCRE behaves:
693 ph10 345
694 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
695 ph10 345
696     (b) A back reference to an unmatched subpattern matches an empty string
697 ph10 336 (Perl fails the current match path).
698 ph10 345
699 ph10 341 (c) A data ] in a character class must be notated as \] because if the
700 ph10 345 first data character in a class is ], it defines an empty class. (In
701 ph10 341 Perl it is not possible to have an empty class.) The empty class []
702     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
703     The negative empty class [^] matches any one character, independently
704     of the DOTALL setting.
705 ph10 345
706     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
707 ph10 340 non-existent subpattern following a character class starting with ']' and
708     containing () gave an internal compiling error instead of "reference to
709     non-existent subpattern". Fortunately, when the pattern did exist, the
710 ph10 345 compiled code was correct. (When scanning forwards to check for the
711 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
712 ph10 345 the class, so got the count wrong. When actually compiling, the reference
713 ph10 340 was subsequently set up correctly.)
714 ph10 345
715 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
716 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
717     other assertions are supported. I have made pcre_dfa_exec() support
718     (*FAIL).
719    
720 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
721 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
722     cannot be changed at match time, I realized I could make a small
723     improvement to matching performance by compiling OP_ALLANY instead of
724     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
725     on the OP_ANY path.
726    
727     17. Compiling pcretest on Windows with readline support failed without the
728 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
729 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
730    
731 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
732 ph10 345 ncurses library to be included for pcretest when ReadLine support is
733     requested, but also to allow for it to be overridden. This patch came from
734     Daniel Bergström.
735 ph10 347
736 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
737 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
738     any errors with the current Unicode tables. Thanks to Peter Kankowski for
739     spotting this.
740 ph10 324
741 ph10 332
742 ph10 319 Version 7.6 28-Jan-08
743 ph10 300 ---------------------
744    
745 ph10 302 1. A character class containing a very large number of characters with
746     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
747     overflow.
748 ph10 309
749     2. Patch to cut out the "long long" test in pcrecpp_unittest when
750     HAVE_LONG_LONG is not defined.
751    
752 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
753 ph10 304 bring them up to date and include new features. This patch includes:
754 ph10 309
755 ph10 304 - Fixed PH's badly added libz and libbz2 support.
756     - Fixed a problem with static linking.
757 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
758 ph10 304 - Fixed dftables problem and added an option.
759     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
760     HAVE_LONG_LONG.
761     - Added readline support for pcretest.
762 ph10 309 - Added an listing of the option settings after cmake has run.
763    
764 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
765     "pcre.dll" under mingw when using Configure/Make. I added stuff to
766     Makefile.am that cause it to include this special target, without
767     affecting anything else. Note that the same mingw target plus all
768     the other distribution libraries and programs are now supported
769     when configuring with CMake (see 6 below) instead of with
770     Configure/Make.
771 ph10 309
772 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
773     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
774 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
775     solves the problem, but it does no harm.
776 ph10 313
777 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
778 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
779 ph10 314 with CMake, and also correct the comment about stack recursion.
780 ph10 313
781 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
782 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
783     of a program that users should build themselves after PCRE is installed, so
784     building it automatically is not really right. What is more, it gave
785 ph10 312 trouble in some build environments.
786 ph10 300
787 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
788 ph10 308
789 ph10 319
790 ph10 298 Version 7.5 10-Jan-08
791 ph10 263 ---------------------
792    
793     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
794     values in parens when parsing an RE using the C++ wrapper."
795 ph10 286
796 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
797     Characters greater than 255 were excluded from the class instead of being
798     included.
799 ph10 286
800     3. The same bug as (2) above applied to negated POSIX classes such as
801 ph10 265 [:^space:].
802 ph10 286
803 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
804     defined or documented. It seems to have been a typo for PCRE_STATIC, so
805 ph10 286 I have changed it.
806    
807 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
808 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
809     first named subpattern whose name started with "a" (in other words, the
810 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
811     expected" is now given for (?&) (a zero-length name), and this patch also
812     makes it give the same error for \k'' (previously it complained that that
813     was a reference to a non-existent subpattern).
814 ph10 286
815 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
816 ph10 286 this is right because (?- can be followed by option settings as well as by
817 ph10 269 digits. I have, however, made the messages clearer.
818 ph10 286
819 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
820     than the number used in the conditional) now cause a compile-time error.
821     This is actually not compatible with Perl, which accepts such patterns, but
822     treats the conditional as always being FALSE (as PCRE used to), but it
823     seems to me that giving a diagnostic is better.
824 ph10 286
825 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
826 ph10 275 and messages.
827 ph10 286
828     9. Fix two occurrences of "backslash" in comments that should have been
829     "backspace".
830    
831     10. Remove two redundant lines of code that can never be obeyed (their function
832     was moved elsewhere).
833    
834     11. The program that makes PCRE's Unicode character property table had a bug
835     which caused it to generate incorrect table entries for sequences of
836 ph10 277 characters that have the same character type, but are in different scripts.
837 ph10 286 It amalgamated them into a single range, with the script of the first of
838 ph10 277 them. In other words, some characters were in the wrong script. There were
839     thirteen such cases, affecting characters in the following ranges:
840 ph10 286
841 ph10 277 U+002b0 - U+002c1
842     U+0060c - U+0060d
843 ph10 286 U+0061e - U+00612
844 ph10 277 U+0064b - U+0065e
845     U+0074d - U+0076d
846     U+01800 - U+01805
847     U+01d00 - U+01d77
848     U+01d9b - U+01dbf
849     U+0200b - U+0200f
850     U+030fc - U+030fe
851     U+03260 - U+0327f
852     U+0fb46 - U+0fbb1
853     U+10450 - U+1049d
854 ph10 286
855 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
856     compatible with GNU grep in that, if there was more than one match in a
857     line, it showed only the first of them. It now behaves in the same way as
858     GNU grep.
859 ph10 286
860     13. If the -o and -v options were combined for pcregrep, it printed a blank
861     line for every non-matching line. GNU grep prints nothing, and pcregrep now
862     does the same. The return code can be used to tell if there were any
863     non-matching lines.
864    
865 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
866    
867     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
868 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
869 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
870     and both kinds of lookbehind were skipped).
871    
872 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
873 ph10 284 inclusion of <windows.h> to before rather than after the definition of
874     INVALID_FILE_ATTRIBUTES (patch from David Byron).
875 ph10 263
876 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
877 ph10 286 character property caused pcre_compile() to compile bad code, which led at
878     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
879     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
880     caused the error; without that there was no problem.
881 ph10 263
882 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
883 ph10 286
884 ph10 289 19. Added --enable-pcretest-libreadline.
885 ph10 286
886 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
887 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
888 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
889     later patch that removed the other one (the right fix) and added unit tests
890     that check the return values (which was not done before).
891 ph10 292
892 ph10 291 21. Several CMake things:
893 ph10 287
894 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
895 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
896 ph10 288
897 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
898     linked with the newly-built libraries, not previously installed ones.
899 ph10 291
900 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
901 ph10 298
902     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
903     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
904     UTF-8 newline character). The key issue is that the pattern starts .*;
905     this means that the match must be either at the beginning, or after a
906     newline. The bug was in the code for advancing after a failed match and
907     checking that the new position followed a newline. It was not taking
908 ph10 294 account of UTF-8 characters correctly.
909 ph10 298
910     23. PCRE was behaving differently from Perl in the way it recognized POSIX
911     character classes. PCRE was not treating the sequence [:...:] as a
912     character class unless the ... were all letters. Perl, however, seems to
913     allow any characters between [: and :], though of course it rejects as
914     unknown any "names" that contain non-letters, because all the known class
915     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
916     for example, whereas PCRE did not - it did not recognize a POSIX character
917     class. This seemed a bit dangerous, so the code has been changed to be
918     closer to Perl. The behaviour is not identical to Perl, because PCRE will
919     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
920     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
921     Perl does, and where it didn't before.
922    
923 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
924     Windows environments %n is disabled by default.
925 ph10 292
926    
927 ph10 260 Version 7.4 21-Sep-07
928 ph10 230 ---------------------
929    
930     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
931 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
932     LF". That isn't really right - the whole point of the change was to try to
933     help when there was an actual mention of one of the two characters. So now
934     the change happens only if \r or \n (or a literal CR or LF) character is
935 ph10 230 encountered.
936 ph10 231
937     2. The 32-bit options word was also used for 6 internal flags, but the numbers
938     of both had grown to the point where there were only 3 bits left.
939     Fortunately, there was spare space in the data structure, and so I have
940     moved the internal flags into a new 16-bit field to free up more option
941 ph10 230 bits.
942 ph10 231
943     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
944     but did not set the internal JCHANGED flag - either of these is enough to
945     control the way the "get" function works - but the PCRE_INFO_JCHANGED
946     facility is supposed to tell if (?J) was ever used, so now (?J) at the
947 ph10 230 start sets both bits.
948    
949 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
950     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
951 ph10 230
952 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
953    
954     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
955 ph10 233 compatibility, even though it is no longer used.
956 ph10 243
957     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
958 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
959 ph10 259 windows.h file is present (where different names are used). [This was
960 ph10 257 reversed later after testing - see 16 below.]
961 ph10 243
962     8. Changed all #include <config.h> to #include "config.h". There were also
963 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
964 ph10 243
965 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
966 ph10 243 sequence off the lines that it output.
967    
968     10. It was pointed out to me that arrays of string pointers cause lots of
969     relocations when a shared library is dynamically loaded. A technique of
970     using a single long string with a table of offsets can drastically reduce
971     these. I have refactored PCRE in four places to do this. The result is
972 ph10 240 dramatic:
973 ph10 243
974 ph10 240 Originally: 290
975     After changing UCP table: 187
976 ph10 243 After changing error message table: 43
977 ph10 240 After changing table of "verbs" 36
978     After changing table of Posix names 22
979 ph10 243
980 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
981 ph10 247
982 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
983 ph10 247 unicode-properties was also set.
984    
985 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
986 ph10 231
987 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
988     checked only for CRLF.
989 ph10 233
990 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
991    
992 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
993 ph10 253
994 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
995 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
996     entirely. This removes changes made in 7 above.
997 ph10 256
998 ph10 261 17. The CMake files have been updated, and there is now more information about
999     building with CMake in the NON-UNIX-USE document.
1000 ph10 257
1001 ph10 261
1002 ph10 228 Version 7.3 28-Aug-07
1003 ph10 157 ---------------------
1004    
1005 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1006     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1007     brackets there is not right, since it causes compilers to look for an
1008     installed pcre.h, not the version that is in the source that is being
1009     compiled (which of course may be different). I have changed it back to:
1010 ph10 197
1011 ph10 189 #include "pcre.h"
1012 ph10 197
1013     I have a vague recollection that the change was concerned with compiling in
1014     different directories, but in the new build system, that is taken care of
1015     by the VPATH setting the Makefile.
1016    
1017 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1018     when the subject happened to end in the byte 0x85 (e.g. if the last
1019     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1020     characters but of course it shouldn't be taken as a newline when it is part
1021     of another character. The bug was that, for an unlimited repeat of . in
1022     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1023     characters when looking for a newline.
1024 ph10 197
1025     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1026    
1027     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1028     in debug output.
1029    
1030 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1031     long printing in the pcrecpp unittest when running under MinGW.
1032 ph10 189
1033 ph10 197 6. ESC_K was left out of the EBCDIC table.
1034 ph10 189
1035 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1036     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1037     limit also applies to "virtual nesting" when a pattern is recursive, and in
1038     this case 1000 isn't so big. I have been able to remove this limit at the
1039     expense of backing off one optimization in certain circumstances. Normally,
1040     when pcre_exec() would call its internal match() function recursively and
1041     immediately return the result unconditionally, it uses a "tail recursion"
1042     feature to save stack. However, when a subpattern that can match an empty
1043     string has an unlimited repetition quantifier, it no longer makes this
1044     optimization. That gives it a stack frame in which to save the data for
1045     checking that an empty string has been matched. Previously this was taken
1046     from the 1000-entry workspace that had been reserved. So now there is no
1047     explicit limit, but more stack is used.
1048 ph10 189
1049 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1050     syntax that is required for Windows, and which was going wrong for the
1051     pcreposix and pcrecpp parts of the library. These were overlooked when this
1052     problem was solved for the main library.
1053 ph10 197
1054 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1055     the size of patterns that contain repeated groups with explicit upper
1056     limits. As the maximum quantifier is 65535, the maximum group length was
1057     set at 30,000 so that the product of these two numbers did not overflow a
1058     32-bit integer. However, it turns out that people want to use groups that
1059     are longer than 30,000 bytes (though not repeat them that many times).
1060     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1061     made it possible to implement the integer overflow checks in a much more
1062     dynamic way, which I have now done. The artificial limitation on group
1063     length has been removed - we now have only the limit on the total length of
1064     the compiled pattern, which depends on the LINK_SIZE setting.
1065 ph10 208
1066     10. Fixed a bug in the documentation for get/copy named substring when
1067     duplicate names are permitted. If none of the named substrings are set, the
1068     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1069     empty string.
1070    
1071     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1072     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1073     because the ] is interpreted as the first data character and the
1074     terminating ] is not found. PCRE has been made compatible with Perl in this
1075     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1076     cause memory overwriting.
1077    
1078 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1079     string has been matched (to stop an infinite loop). It was not recognizing
1080 ph10 208 a conditional subpattern that could match an empty string if that
1081 ph10 206 subpattern was within another subpattern. For example, it looped when
1082 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1083 ph10 206 condition was not nested. This bug has been fixed.
1084 ph10 208
1085 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1086     past the start of the subject in the presence of bytes with the top bit
1087     set, for example "\x8aBCD".
1088 ph10 211
1089 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1090     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1091 ph10 200
1092 ph10 211 14. Optimized (?!) to (*FAIL).
1093 ph10 202
1094 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1095     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1096     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1097     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1098     does: it's just the validity check that is more restrictive.
1099 ph10 220
1100     16. Inserted checks for integer overflows during escape sequence (backslash)
1101     processing, and also fixed erroneous offset values for syntax errors during
1102     backslash processing.
1103    
1104 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1105 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1106    
1107 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1108     caused an overrun.
1109 ph10 220
1110     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1111     something other than just ASCII characters) inside a group that had an
1112     unlimited repeat caused a loop at compile time (while checking to see
1113     whether the group could match an empty string).
1114    
1115 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1116     [\P{Any}] did so. (Error in the code for printing property names.)
1117 ph10 210
1118 ph10 220 21. An orphan \E inside a character class could cause a crash.
1119    
1120     22. A repeated capturing bracket such as (A)? could cause a wild memory
1121 ph10 218 reference during compilation.
1122 ph10 220
1123     23. There are several functions in pcre_compile() that scan along a compiled
1124     expression for various reasons (e.g. to see if it's fixed length for look
1125 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1126 ph10 220 present in the pattern. These operators have additional parameters compared
1127     with \d, etc, and these were not being taken into account when moving along
1128 ph10 218 the compiled data. Specifically:
1129 ph10 220
1130     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1131     length.
1132    
1133     (b) An item such as \pL+ within a repeated group could cause crashes or
1134 ph10 218 loops.
1135 ph10 220
1136 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1137 ph10 220 "reference to non-existent subpattern" error.
1138    
1139 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1140    
1141 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1142 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1143 ph10 211
1144 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1145 ph10 218
1146 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1147 ph10 223 character were causing crashes (broken optimization).
1148 ph10 227
1149 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1150 ph10 227 \p or \P) caused a compile-time loop.
1151    
1152 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1153     break. For example, the unstudied pattern [\r\n]A does not match the string
1154     "\r\nA" because change 7.0/46 below moves the current point on by two
1155     characters after failing to match at the start. However, the pattern \nA
1156 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1157     the same is true. There doesn't seem any very clean way out of this, but
1158     what I have chosen to do makes the common cases work: PCRE now takes note
1159     of whether there can be an explicit match for \r or \n anywhere in the
1160     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1161     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1162     pattern has explicit CR or LF references.
1163 ph10 222
1164 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1165 ph10 223
1166 ph10 227
1167 ph10 189 Version 7.2 19-Jun-07
1168     ---------------------
1169    
1170 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1171     which is apparently normally available under Windows.
1172 ph10 159
1173     2. Re-jig the pcregrep tests with different newline settings in an attempt
1174     to make them independent of the local environment's newline setting.
1175 ph10 157
1176 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1177 ph10 165
1178 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1179     was not 2, because the output contained actual offsets. The recent new
1180 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1181     usable with all link sizes.
1182    
1183 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1184     stack recursion. This gives a massive performance boost under BSD, but just
1185 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1186 ph10 164 in all cases.
1187 ph10 172
1188 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1189 ph10 172
1190 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1191     recursion call. It refers to the nth most recently opened parentheses.
1192 ph10 172
1193 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1194 ph10 172 to be opened parentheses.
1195    
1196     (c) Conditions that refer to capturing parentheses can be specified
1197 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1198 ph10 172
1199 ph10 168 (d) \K resets the start of the current match so that everything before
1200 ph10 172 is not part of it.
1201    
1202 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1203 ph10 172
1204 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1205 ph10 172 reference syntax.
1206 ph10 182
1207 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1208 ph10 182 alternative starts with the same number.
1209 ph10 172
1210 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1211    
1212 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1213     PCRE_INFO_JCHANGED.
1214    
1215     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1216     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1217 ph10 170 for detecting groups that can match an empty string.
1218 ph10 159
1219 ph10 172 9. A pattern with a very large number of alternatives (more than several
1220     hundred) was running out of internal workspace during the pre-compile
1221     phase, where pcre_compile() figures out how much memory will be needed. A
1222     bit of new cunning has reduced the workspace needed for groups with
1223     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1224     workspace instead of running out of the 4096 that are available.
1225 ph10 182
1226 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1227 ph10 172
1228 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1229     The report of the bug said:
1230 ph10 182
1231 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1232     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1233 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1234 ph10 185
1235 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1236 ph10 185 it matched the wrong number of bytes.
1237 ph10 172
1238 ph10 179
1239 ph10 155 Version 7.1 24-Apr-07
1240 ph10 98 ---------------------
1241    
1242 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1243 ph10 122 that is more "standard", making use of automake and other Autotools. There
1244 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1245     on this.
1246 ph10 111
1247     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1248     for recursive directory scanning broke on some systems because the files
1249     are not scanned in any specific order and on different systems the order
1250     was different. A call to "sort" has been inserted into RunGrepTest for the
1251     approprate test as a short-term fix. In the longer term there may be an
1252 ph10 100 alternative.
1253 ph10 111
1254 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1255 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1256     people do their own conversions for various reasons). The problems
1257     concerned the use of low-level troff macros .br and .in. I have therefore
1258     removed all such uses from the man pages (some were redundant, some could
1259 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1260     HTML has been updated to handle .nf/.fi and to complain if it encounters
1261     .br or .in.
1262 ph10 111
1263 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1264 ph10 123 arranged for config.h to be included in the distribution, with the name
1265 ph10 111 config.h.generic, for the benefit of those who have to compile without
1266     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1267    
1268     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1269     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1270 ph10 127 makevp.bat for the current PCRE, using the additional files
1271 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1272 ph10 111
1273     6. A Windows user reported a minor discrepancy with test 2, which turned out
1274     to be caused by a trailing space on an input line that had got lost in his
1275 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1276 ph10 111
1277 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1278 ph10 111 that is needed.
1279    
1280 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1281     as "const" (a) because they are and (b) because it helps the PHP
1282     maintainers who have recently made a script to detect big data structures
1283 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1284     to update Builducptable as well, so it won't revert if ucptable.h is ever
1285 ph10 105 re-created.
1286 ph10 111
1287     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1288 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1289 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1290     support is not required. This saves 1.5-2K of code, which is important in
1291 ph10 107 some applications.
1292 ph10 111
1293 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1294 ph10 111 so as not to refer to the tables, even though these functions will never be
1295     called when UTF-8 support is disabled. Otherwise there are problems with a
1296     shared library.
1297    
1298 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1299    
1300     (a) It was defining its arguments as char * instead of void *.
1301    
1302 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1303     a long time ago when I wrote it, but is no longer the case.
1304    
1305 ph10 118 The emulated memove() is provided for those environments that have neither
1306 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1307 ph10 118 is clearly not the case, as these two bugs were recently reported.
1308 ph10 123
1309 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1310 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1311     pages, and it removes trailing spaces from listed files. It also creates
1312     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1313     case, it wraps all the #defines with #ifndefs. This script should be run
1314 ph10 111 before "make dist".
1315 ph10 123
1316 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1317     with Unicode property support.
1318 ph10 123
1319     (a) For a maximizing quantifier, if the two different cases of the
1320     character were of different lengths in their UTF-8 codings (there are
1321     some cases like this - I found 11), and the matching function had to
1322 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1323     were both the same length.
1324 ph10 123
1325     (b) When PCRE was configured to use the heap rather than the stack for
1326     recursion during matching, it was not correctly preserving the data for
1327     the other case of a UTF-8 character when checking ahead for a match
1328     while processing a minimizing repeat. If the check also involved
1329 ph10 115 matching a wide character, but failed, corruption could cause an
1330     erroneous result when trying to check for a repeat of the original
1331     character.
1332 ph10 123
1333 ph10 116 13. Some tidying changes to the testing mechanism:
1334 ph10 98
1335 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1336     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1337 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1338     this for UTF-8.) The configure.ac script no longer substitutes the
1339     relevant variables.
1340    
1341 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1342     with length and offset values. This means that the output is different
1343     for different internal link sizes. Test 2 is skipped for link sizes
1344     other than 2 because of this, bypassing the problem. Unfortunately,
1345     there was also a test in test 3 (the locale tests) that used /B and
1346 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1347     I have added a new /Z option to pcretest that replaces the length and
1348     offset values with spaces. This is now used to make test 3 independent
1349 ph10 122 of link size. (Test 2 will be tidied up later.)
1350 ph10 123
1351     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1352 ph10 122 segmentation fault instead of returning the appropriate error message.
1353 ph10 134
1354 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1355 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1356     This doesn't seem right; it now treats the CRLF combination as the line
1357     ending, and so does not match in that case. It's only a pattern such as ^$
1358     that would hit this one: something like ^ABC$ would have failed after \r
1359     and then tried again after \r\n.
1360    
1361 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1362 ph10 134 in an attempt to make files that differ only in their line terminators
1363     compare equal. This works on Linux.
1364 ph10 142
1365 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1366     as it exited. This is now fixed, thanks to valgrind.
1367 ph10 142
1368 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1369 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1370     was because its rules for how to advance for /g after matching an empty
1371 ph10 143 string at the end of a line did not allow for this case. They now check for
1372     it specially.
1373 ph10 150
1374     20. pcretest is supposed to handle patterns and data of any length, by
1375     extending its buffers when necessary. It was getting this wrong when the
1376 ph10 147 buffer for a data line had to be extended.
1377 ph10 150
1378 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1379 ph10 150 CRLF as a newline sequence.
1380 ph10 152
1381 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1382 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1383     I have nevertheless tidied it up.
1384 ph10 111
1385 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1386 ph10 123
1387 ph10 153 24. Added a man page for pcre-config.
1388 ph10 152
1389 ph10 153
1390 nigel 93 Version 7.0 19-Dec-06
1391     ---------------------
1392    
1393     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1394     moving to gcc 4.1.1.
1395    
1396     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1397     sys/time.h, which is documented as needed for this function. It doesn't
1398     seem to matter on Linux, but it showed up on some releases of OS X.
1399    
1400     3. It seems that there are systems where bytes whose values are greater than
1401     127 match isprint() in the "C" locale. The "C" locale should be the
1402     default when a C program starts up. In most systems, only ASCII printing
1403     characters match isprint(). This difference caused the output from pcretest
1404     to vary, making some of the tests fail. I have changed pcretest so that:
1405    
1406     (a) When it is outputting text in the compiled version of a pattern, bytes
1407     other than 32-126 are always shown as hex escapes.
1408    
1409     (b) When it is outputting text that is a matched part of a subject string,
1410     it does the same, unless a different locale has been set for the match
1411     (using the /L modifier). In this case, it uses isprint() to decide.
1412    
1413     4. Fixed a major bug that caused incorrect computation of the amount of memory
1414     required for a compiled pattern when options that changed within the
1415     pattern affected the logic of the preliminary scan that determines the
1416     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1417     that the computed length was too small. The symptoms of this bug were
1418     either the PCRE error "internal error: code overflow" from pcre_compile(),
1419     or a glibc crash with a message such as "pcretest: free(): invalid next
1420     size (fast)". Examples of patterns that provoked this bug (shown in
1421     pcretest format) are:
1422    
1423     /(?-x: )/x
1424     /(?x)(?-x: \s*#\s*)/
1425     /((?i)[\x{c0}])/8
1426     /(?i:[\x{c0}])/8
1427    
1428     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1429     is now done differently.
1430    
1431     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1432     wrapper classes; (b) implement a new function in the C++ scanner that is
1433     more efficient than the old way of doing things because it avoids levels of
1434     recursion in the regex matching; (c) add a paragraph to the documentation
1435     for the FullMatch() function.
1436    
1437     6. The escape sequence \n was being treated as whatever was defined as
1438     "newline". Not only was this contrary to the documentation, which states
1439     that \n is character 10 (hex 0A), but it also went horribly wrong when
1440     "newline" was defined as CRLF. This has been fixed.
1441    
1442     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1443     was being set to -1 for the "end of line" case (supposedly a value that no
1444     character can have). Though this value is never used (the check for end of
1445     line is "zero bytes in current character"), it caused compiler complaints.
1446     I've changed it to 0xffffffff.
1447    
1448     8. In pcre_version.c, the version string was being built by a sequence of
1449     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1450     string (as it is for production releases) called a macro with an empty
1451     argument. The C standard says the result of this is undefined. The gcc
1452     compiler treats it as an empty string (which was what was wanted) but it is
1453     reported that Visual C gives an error. The source has been hacked around to
1454     avoid this problem.
1455    
1456     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1457     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1458     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1459     of them did).
1460    
1461     10. Originally, pcretest opened its input and output without "b"; then I was
1462     told that "b" was needed in some environments, so it was added for release
1463     5.0 to both the input and output. (It makes no difference on Unix-like
1464     systems.) Later I was told that it is wrong for the input on Windows. I've
1465     now abstracted the modes into two macros, to make it easier to fiddle with
1466     them, and removed "b" from the input mode under Windows.
1467    
1468     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1469    
1470     12. Added -help and --help to pcretest as an official way of being reminded
1471     of the options.
1472    
1473     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1474     and pcrecpp.cc because they annoy compilers at high warning levels.
1475    
1476     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1477    
1478     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1479     scripts are not C programs :-) and which was not noticed because it works
1480     on Linux.
1481    
1482     16. pcretest is supposed to handle any length of pattern and data line (as one
1483     line or as a continued sequence of lines) by extending its input buffer if
1484     necessary. This feature was broken for very long pattern lines, leading to
1485     a string of junk being passed to pcre_compile() if the pattern was longer
1486     than about 50K.
1487    
1488     17. I have done a major re-factoring of the way pcre_compile() computes the
1489     amount of memory needed for a compiled pattern. Previously, there was code
1490     that made a preliminary scan of the pattern in order to do this. That was
1491     OK when PCRE was new, but as the facilities have expanded, it has become
1492     harder and harder to keep it in step with the real compile phase, and there
1493     have been a number of bugs (see for example, 4 above). I have now found a
1494     cunning way of running the real compile function in a "fake" mode that
1495     enables it to compute how much memory it would need, while actually only
1496     ever using a few hundred bytes of working memory and without too many
1497     tests of the mode. This should make future maintenance and development
1498     easier. A side effect of this work is that the limit of 200 on the nesting
1499     depth of parentheses has been removed (though this was never a serious
1500     limitation, I suspect). However, there is a downside: pcre_compile() now
1501     runs more slowly than before (30% or more, depending on the pattern). I
1502     hope this isn't a big issue. There is no effect on runtime performance.
1503    
1504     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1505     newline (only possible for the last line of a file) and it was a
1506     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1507    
1508     19. Added additional timing features to pcretest. (1) The -tm option now times
1509     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1510     separate command line item, by a number that specifies the number of
1511     repeats to use when timing. The default is 50000; this gives better
1512     precision, but takes uncomfortably long for very large patterns.
1513    
1514     20. Extended pcre_study() to be more clever in cases where a branch of a
1515     subpattern has no definite first character. For example, (a*|b*)[cd] would
1516     previously give no result from pcre_study(). Now it recognizes that the
1517     first character must be a, b, c, or d.
1518    
1519     21. There was an incorrect error "recursive call could loop indefinitely" if
1520     a subpattern (or the entire pattern) that was being tested for matching an
1521     empty string contained only one non-empty item after a nested subpattern.
1522     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1523     incorrectly, because the \d was being skipped in the check.
1524    
1525     22. The pcretest program now has a new pattern option /B and a command line
1526     option -b, which is equivalent to adding /B to every pattern. This causes
1527     it to show the compiled bytecode, without the additional information that
1528     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1529     is the same as /B/I).
1530    
1531     23. A new optimization is now able automatically to treat some sequences such
1532     as a*b as a*+b. More specifically, if something simple (such as a character
1533     or a simple class like \d) has an unlimited quantifier, and is followed by
1534     something that cannot possibly match the quantified thing, the quantifier
1535     is automatically "possessified".
1536    
1537     24. A recursive reference to a subpattern whose number was greater than 39
1538     went wrong under certain circumstances in UTF-8 mode. This bug could also
1539     have affected the operation of pcre_study().
1540    
1541     25. Realized that a little bit of performance could be had by replacing
1542     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1543    
1544     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1545    
1546     27. Possessive quantifiers such as a++ were previously implemented by turning
1547     them into atomic groups such as ($>a+). Now they have their own opcodes,
1548     which improves performance. This includes the automatically created ones
1549     from 23 above.
1550    
1551     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1552     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1553     the first matched character to be a colon. This applied both to named and
1554     numbered groups.
1555    
1556     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1557    
1558     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1559     building PCRE on Windows easier, so I have included it in the distribution.
1560    
1561     31. There is now a check in pcretest against a ridiculously large number being
1562     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1563     loop, the loop is abandoned.
1564    
1565     32. Forward references to subpatterns in conditions such as (?(2)...) where
1566     subpattern 2 is defined later cause pcre_compile() to search forwards in
1567     the pattern for the relevant set of parentheses. This search went wrong
1568     when there were unescaped parentheses in a character class, parentheses
1569     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1570    
1571     33. "Subroutine" calls and backreferences were previously restricted to
1572     referencing subpatterns earlier in the regex. This restriction has now
1573     been removed.
1574    
1575     34. Added a number of extra features that are going to be in Perl 5.10. On the
1576     whole, these are just syntactic alternatives for features that PCRE had
1577     previously implemented using the Python syntax or my own invention. The
1578     other formats are all retained for compatibility.
1579    
1580     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1581     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1582     also .NET compatible.
1583    
1584     (b) A recursion or subroutine call to a named group can now be defined as
1585     (?&name) as well as (?P>name).
1586    
1587     (c) A backreference to a named group can now be defined as \k<name> or
1588     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1589     5.10, are also .NET compatible.
1590    
1591     (d) A conditional reference to a named group can now use the syntax
1592     (?(<name>) or (?('name') as well as (?(name).
1593    
1594     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1595     groups (named and numbered) that are never evaluated inline, but can be
1596     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1597     is always false. There may be only one alternative in such a group.
1598    
1599     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1600     as the simple (?(R). The condition is true only if the most recent
1601     recursion is that of the given number or name. It does not search out
1602     through the entire recursion stack.
1603    
1604     (g) The escape \gN or \g{N} has been added, where N is a positive or
1605     negative number, specifying an absolute or relative reference.
1606    
1607     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1608     some "unreachable code" warnings.
1609    
1610     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1611     things, this adds five new scripts.
1612    
1613     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1614     There were also incompatibilities regarding the handling of \Q..\E inside
1615     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1616     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1617    
1618     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1619     matches an empty string, and forcibly breaks the loop. There were bugs in
1620     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1621     against aaaa the result was just "a" rather than "aaaa", for example. Two
1622     separate and independent bugs (that affected different cases) have been
1623     fixed.
1624    
1625     39. Refactored the code to abolish the use of different opcodes for small
1626     capturing bracket numbers. This is a tidy that I avoided doing when I
1627     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1628     The new approach is not only tidier, it makes it possible to reduce the
1629     memory needed to fix the previous bug (38).
1630    
1631     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1632     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1633     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1634     mode.
1635    
1636     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1637     report.
1638    
1639     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1640     copy construction and assignment in the C++ wrapper.
1641    
1642     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1643     couple of bugs that could have given wrong results in the "--newline=crlf"
1644     case.
1645    
1646     44. Added a number of casts and did some reorganization of signed/unsigned int
1647     variables following suggestions from Dair Grant. Also renamed the variable
1648     "this" as "item" because it is a C++ keyword.
1649    
1650     45. Arranged for dftables to add
1651    
1652     #include "pcre_internal.h"
1653    
1654     to pcre_chartables.c because without it, gcc 4.x may remove the array
1655     definition from the final binary if PCRE is built into a static library and
1656     dead code stripping is activated.
1657    
1658     46. For an unanchored pattern, if a match attempt fails at the start of a
1659     newline sequence, and the newline setting is CRLF or ANY, and the next two
1660     characters are CRLF, advance by two characters instead of one.
1661    
1662    
1663 nigel 91 Version 6.7 04-Jul-06
1664     ---------------------
1665    
1666     1. In order to handle tests when input lines are enormously long, pcretest has
1667     been re-factored so that it automatically extends its buffers when
1668     necessary. The code is crude, but this _is_ just a test program. The
1669     default size has been increased from 32K to 50K.
1670    
1671     2. The code in pcre_study() was using the value of the re argument before
1672     testing it for NULL. (Of course, in any sensible call of the function, it
1673     won't be NULL.)
1674    
1675     3. The memmove() emulation function in pcre_internal.h, which is used on
1676     systems that lack both memmove() and bcopy() - that is, hardly ever -
1677     was missing a "static" storage class specifier.
1678    
1679     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1680     containing an extended class (one that cannot be represented by a bitmap
1681     because it contains high-valued characters or Unicode property items, e.g.
1682     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1683     pattern, but PCRE should not loop if you do not (it no longer does).
1684     [Detail: two cases were found: (a) a repeated subpattern containing an
1685     extended class; (b) a recursive reference to a subpattern that followed a
1686     previous extended class. It wasn't skipping over the extended class
1687     correctly when UTF-8 mode was not set.]
1688    
1689     5. A negated single-character class was not being recognized as fixed-length
1690     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1691     compile error "lookbehind assertion is not fixed length".
1692    
1693     6. The RunPerlTest auxiliary script was showing an unexpected difference
1694     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1695     write a Perl script that can interpret lines of an input file either as
1696     byte characters or as UTF-8, which is what "perltest" was being required to
1697     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1698     can't do is switch easily at run time between having the "use utf8;" pragma
1699     or not. In the end, I fudged it by using the RunPerlTest script to insert
1700     "use utf8;" explicitly for the UTF-8 tests.
1701    
1702     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1703     the end of the subject string, contrary to the documentation and to what
1704     Perl does. This was true of both matching functions. Now it matches only at
1705     the start of the subject and immediately after *internal* newlines.
1706    
1707     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1708     a pointer to an int instead of a pointer to an unsigned long int. This
1709     caused problems on 64-bit systems.
1710    
1711     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1712     instance of the 'standard' template library not being so standard".
1713    
1714     10. There was no check on the number of named subpatterns nor the maximum
1715     length of a subpattern name. The product of these values is used to compute
1716     the size of the memory block for a compiled pattern. By supplying a very
1717     long subpattern name and a large number of named subpatterns, the size
1718     computation could be caused to overflow. This is now prevented by limiting
1719     the length of names to 32 characters, and the number of named subpatterns
1720     to 10,000.
1721    
1722     11. Subpatterns that are repeated with specific counts have to be replicated in
1723     the compiled pattern. The size of memory for this was computed from the
1724     length of the subpattern and the repeat count. The latter is limited to
1725     65535, but there was no limit on the former, meaning that integer overflow
1726     could in principle occur. The compiled length of a repeated subpattern is
1727     now limited to 30,000 bytes in order to prevent this.
1728    
1729     12. Added the optional facility to have named substrings with the same name.
1730    
1731     13. Added the ability to use a named substring as a condition, using the
1732     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1733     are numbers (not recommended). Forward references are permitted.
1734    
1735     14. Added forward references in named backreferences (if you see what I mean).
1736    
1737     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1738     pattern could run off the end of the subject. For example, the pattern
1739     "(?s)(.{1,5})"8 did this with the subject "ab".
1740    
1741     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1742     PCRE_CASELESS was set when matching characters that were quantified with ?
1743     or *.
1744    
1745     17. A character class other than a single negated character that had a minimum
1746     but no maximum quantifier - for example [ab]{6,} - was not handled
1747     correctly by pce_dfa_exec(). It would match only one character.
1748    
1749     18. A valid (though odd) pattern that looked like a POSIX character
1750     class but used an invalid character after [ (for example [[,abc,]]) caused
1751     pcre_compile() to give the error "Failed: internal error: code overflow" or
1752     in some cases to crash with a glibc free() error. This could even happen if
1753     the pattern terminated after [[ but there just happened to be a sequence of
1754     letters, a binary zero, and a closing ] in the memory that followed.
1755    
1756     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1757     over the years. Originally (before any Unicode support), just the bottom 8
1758     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1759     output from "man perlunicode" includes this:
1760    
1761     The regular expression compiler produces polymorphic opcodes. That
1762     is, the pattern adapts to the data and automatically switches to
1763     the Unicode character scheme when presented with Unicode data--or
1764     instead uses a traditional byte scheme when presented with byte
1765     data.
1766    
1767     Sadly, a wide octal escape does not cause a switch, and in a string with
1768     no other multibyte characters, these octal escapes are treated as before.
1769     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1770     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1771     Unicode string.
1772    
1773     I have not perpetrated such confusion in PCRE. Up till now, it took just
1774     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1775     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1776     translate to the appropriate multibyte character.
1777    
1778     29. Applied some refactoring to reduce the number of warnings from Microsoft
1779     and Borland compilers. This has included removing the fudge introduced
1780     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1781     a warning about an unused variable.
1782    
1783     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1784     characters since release 4.0, because Perl (from release 5.004) does not.
1785     [Or at least, is documented not to: some releases seem to be in conflict
1786     with the documentation.] However, when a pattern was studied with
1787     pcre_study() and all its branches started with \s, PCRE still included VT
1788     as a possible starting character. Of course, this did no harm; it just
1789     caused an unnecessary match attempt.
1790    
1791     22. Removed a now-redundant internal flag bit that recorded the fact that case
1792     dependency changed within the pattern. This was once needed for "required
1793     byte" processing, but is no longer used. This recovers a now-scarce options
1794     bit. Also moved the least significant internal flag bit to the most-
1795     significant bit of the word, which was not previously used (hangover from
1796     the days when it was an int rather than a uint) to free up another bit for
1797     the future.
1798    
1799     23. Added support for CRLF line endings as well as CR and LF. As well as the
1800     default being selectable at build time, it can now be changed at runtime
1801     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1802     specify that it is scanning data with non-default line endings.
1803    
1804     24. Changed the definition of CXXLINK to make it agree with the definition of
1805     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1806    
1807     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1808     recursions. This makes a big different to stack usage for some patterns.
1809    
1810     26. If a subpattern containing a named recursion or subroutine reference such
1811     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1812     the space required for the compiled pattern went wrong and gave too small a
1813     value. Depending on the environment, this could lead to "Failed: internal
1814     error: code overflow at offset 49" or "glibc detected double free or
1815     corruption" errors.
1816    
1817     27. Applied patches from Google (a) to support the new newline modes and (b) to
1818     advance over multibyte UTF-8 characters in GlobalReplace.
1819    
1820     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1821     difference for some implementation of PCRE in some Windows version.
1822    
1823     29. Added some extra testing facilities to pcretest:
1824    
1825     \q<number> in a data line sets the "match limit" value
1826     \Q<number> in a data line sets the "match recursion limt" value
1827     -S <number> sets the stack size, where <number> is in megabytes
1828    
1829     The -S option isn't available for Windows.
1830    
1831    
1832 nigel 89 Version 6.6 06-Feb-06
1833     ---------------------
1834    
1835     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1836     in pcreposix.h. I have copied the definition from pcre.h.
1837    
1838     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1839     because pcre.h is no longer a built file.
1840    
1841     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1842     not normally included in the compiled code.
1843    
1844    
1845 nigel 87 Version 6.5 01-Feb-06
1846     ---------------------
1847    
1848     1. When using the partial match feature with pcre_dfa_exec(), it was not
1849     anchoring the second and subsequent partial matches at the new starting
1850     point. This could lead to incorrect results. For example, with the pattern
1851     /1234/, partially matching against "123" and then "a4" gave a match.
1852    
1853     2. Changes to pcregrep:
1854    
1855     (a) All non-match returns from pcre_exec() were being treated as failures
1856     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1857     error message is output. Some extra information is given for the
1858     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1859     probably the only errors that are likely to be caused by users (by
1860     specifying a regex that has nested indefinite repeats, for instance).
1861     If there are more than 20 of these errors, pcregrep is abandoned.
1862    
1863     (b) A binary zero was treated as data while matching, but terminated the
1864     output line if it was written out. This has been fixed: binary zeroes
1865     are now no different to any other data bytes.
1866    
1867     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1868     used to set a locale for matching. The --locale=xxxx long option has
1869     been added (no short equivalent) to specify a locale explicitly on the
1870     pcregrep command, overriding the environment variables.
1871    
1872     (d) When -B was used with -n, some line numbers in the output were one less
1873     than they should have been.
1874    
1875     (e) Added the -o (--only-matching) option.
1876    
1877     (f) If -A or -C was used with -c (count only), some lines of context were
1878     accidentally printed for the final match.
1879    
1880     (g) Added the -H (--with-filename) option.
1881    
1882     (h) The combination of options -rh failed to suppress file names for files
1883     that were found from directory arguments.
1884    
1885     (i) Added the -D (--devices) and -d (--directories) options.
1886    
1887     (j) Added the -F (--fixed-strings) option.
1888    
1889     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1890    
1891     (l) Added the --colo(u)r option.
1892    
1893     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1894     is not present by default.
1895    
1896     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1897     items such as (?R) or (?1), when the recursion could match a number of
1898     alternatives. If it matched one of the alternatives, but subsequently,
1899     outside the recursion, there was a failure, the code tried to back up into
1900     the recursion. However, because of the way PCRE is implemented, this is not
1901     possible, and the result was an incorrect result from the match.
1902    
1903     In order to prevent this happening, the specification of recursion has
1904     been changed so that all such subpatterns are automatically treated as
1905     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1906    
1907     4. I had overlooked the fact that, in some locales, there are characters for
1908     which isalpha() is true but neither isupper() nor islower() are true. In
1909     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1910     and ordfeminine) are like this. This affected the treatment of \w and \W
1911     when they appeared in character classes, but not when they appeared outside
1912     a character class. The bit map for "word" characters is now created
1913     separately from the results of isalnum() instead of just taking it from the
1914     upper, lower, and digit maps. (Plus the underscore character, of course.)
1915    
1916     5. The above bug also affected the handling of POSIX character classes such as
1917     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1918     permanent tables. Instead, the bit maps for such a class were previously
1919     created as the appropriate unions of the upper, lower, and digit bitmaps.
1920     Now they are created by subtraction from the [[:word:]] class, which has
1921     its own bitmap.
1922    
1923     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1924     It is created by subtracting the vertical space characters (\x09, \x0a,
1925     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1926     subtraction was done in the overall bitmap for a character class, meaning
1927     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1928     be recognized. This bug has been fixed.
1929    
1930     7. Patches from the folks at Google:
1931    
1932     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1933     real life, but is still worth protecting against".
1934    
1935     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1936     regular expressions".
1937    
1938     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1939     have it.
1940    
1941     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1942     "configure" and the latter not, in order to fix a problem somebody had
1943     with compiling the Arg class on HP-UX.
1944    
1945     (e) Improve the error-handling of the C++ wrapper a little bit.
1946    
1947     (f) New tests for checking recursion limiting.
1948    
1949     8. The pcre_memmove() function, which is used only if the environment does not
1950     have a standard memmove() function (and is therefore rarely compiled),
1951     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1952     returning a result (though PCRE never actually uses the result).
1953    
1954     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1955     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1956     returned instead of calling malloc() with an overflowing number that would
1957     most likely cause subsequent chaos.
1958    
1959     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1960    
1961     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1962     with this option is matched, the nmatch and pmatch options of regexec() are
1963     ignored.
1964    
1965     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1966     provided in case anyone wants to the the POSIX interface with UTF-8
1967     strings.
1968    
1969     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1970     C++ linking (needed for some HP-UX environments).
1971    
1972     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1973     (unused parameter) and in the pcre_printint() function (omitted "default"
1974     switch label when the default is to do nothing).
1975    
1976     15. Added some code to make it possible, when PCRE is compiled as a C++
1977     library, to replace subject pointers for pcre_exec() with a smart pointer
1978     class, thus making it possible to process discontinuous strings.
1979    
1980     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1981     much the same function. They were added by different people who were trying
1982     to make PCRE easy to compile on non-Unix systems. It has been suggested
1983     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1984     for compiling on Windows systems. I have therefore replaced it with
1985     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1986     defaults to "extern" for C or "extern C" for C++, which works fine on
1987     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1988     SCOPE with something explicit in config.h. In addition:
1989    
1990     (a) pcreposix.h still had just "extern" instead of either of these macros;
1991     I have replaced it with PCRE_DATA_SCOPE.
1992    
1993     (b) Functions such as _pcre_xclass(), which are internal to the library,
1994     but external in the C sense, all had PCRE_EXPORT in their definitions.
1995     This is apparently wrong for the Windows case, so I have removed it.
1996     (It makes no difference on Unix-like systems.)
1997    
1998     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1999     of recursive calls to match(). This is different to MATCH_LIMIT because
2000     that limits the total number of calls to match(), not all of which increase
2001     the depth of recursion. Limiting the recursion depth limits the amount of
2002     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2003     when PCRE is compiled, and changed at run time. A patch from Google adds
2004     this functionality to the C++ interface.
2005    
2006     18. Changes to the handling of Unicode character properties:
2007    
2008     (a) Updated the table to Unicode 4.1.0.
2009    
2010     (b) Recognize characters that are not in the table as "Cn" (undefined).
2011    
2012     (c) I revised the way the table is implemented to a much improved format
2013     which includes recognition of ranges. It now supports the ranges that
2014     are defined in UnicodeData.txt, and it also amalgamates other
2015     characters into ranges. This has reduced the number of entries in the
2016     table from around 16,000 to around 3,000, thus reducing its size
2017     considerably. I realized I did not need to use a tree structure after
2018     all - a binary chop search is just as efficient. Having reduced the
2019     number of entries, I extended their size from 6 bytes to 8 bytes to
2020     allow for more data.
2021    
2022     (d) Added support for Unicode script names via properties such as \p{Han}.
2023    
2024     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2025     matching that character.
2026    
2027     20. When matching a repeated Unicode property with a minimum greater than zero,
2028     (for example \pL{2,}), PCRE could look past the end of the subject if it
2029     reached it while seeking the minimum number of characters. This could
2030     happen only if some of the characters were more than one byte long, because
2031     there is a check for at least the minimum number of bytes.
2032    
2033     21. Refactored the implementation of \p and \P so as to be more general, to
2034     allow for more different types of property in future. This has changed the
2035     compiled form incompatibly. Anybody with saved compiled patterns that use
2036     \p or \P will have to recompile them.
2037    
2038     22. Added "Any" and "L&" to the supported property types.
2039    
2040     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2041     but give a compile time error if the value is greater than 0xff.
2042    
2043     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2044     accidentally not being installed or uninstalled.
2045    
2046     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2047     made were to insert the current release number. This seemed silly, because
2048     it made things harder for people building PCRE on systems that don't run
2049     "configure". I have turned pcre.h into a distributed file, no longer built
2050     by "configure", with the version identification directly included. There is
2051     no longer a pcre.h.in file.
2052    
2053     However, this change necessitated a change to the pcre-config script as
2054     well. It is built from pcre-config.in, and one of the substitutions was the
2055     release number. I have updated configure.ac so that ./configure now finds
2056     the release number by grepping pcre.h.
2057    
2058     26. Added the ability to run the tests under valgrind.
2059    
2060    
2061 nigel 85 Version 6.4 05-Sep-05
2062     ---------------------
2063    
2064     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2065     "--" to be printed when multiple files were scanned, even when none of the
2066     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2067     consider it to be a bug, and have restored the previous behaviour.
2068    
2069     2. A couple of code tidies to get rid of compiler warnings.
2070    
2071     3. The pcretest program used to cheat by referring to symbols in the library
2072     whose names begin with _pcre_. These are internal symbols that are not
2073     really supposed to be visible externally, and in some environments it is
2074     possible to suppress them. The cheating is now confined to including
2075     certain files from the library's source, which is a bit cleaner.
2076    
2077     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2078     file's purpose clearer.
2079    
2080     5. Reorganized pcre_ucp_findchar().
2081    
2082    
2083 nigel 83 Version 6.3 15-Aug-05
2084     ---------------------
2085    
2086     1. The file libpcre.pc.in did not have general read permission in the tarball.
2087    
2088     2. There were some problems when building without C++ support:
2089    
2090     (a) If C++ support was not built, "make install" and "make test" still
2091     tried to test it.
2092    
2093     (b) There were problems when the value of CXX was explicitly set. Some
2094     changes have been made to try to fix these, and ...
2095    
2096     (c) --disable-cpp can now be used to explicitly disable C++ support.
2097    
2098     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2099     backslash in a target when C++ was disabled. This confuses some
2100     versions of "make", apparently. Using an intermediate variable solves
2101     this. (Same for CPP_LOBJ.)
2102    
2103     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2104     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2105     necessary on certain architectures.
2106    
2107     4. Added a setting of -export-symbols-regex to the link command to remove
2108     those symbols that are exported in the C sense, but actually are local
2109     within the library, and not documented. Their names all begin with
2110     "_pcre_". This is not a perfect job, because (a) we have to except some
2111     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2112     available (and never for static libraries). I have made a note to try to
2113     find a way round (a) in the future.
2114    
2115    
2116 nigel 81 Version 6.2 01-Aug-05
2117     ---------------------
2118    
2119     1. There was no test for integer overflow of quantifier values. A construction
2120     such as {1111111111111111} would give undefined results. What is worse, if
2121     a minimum quantifier for a parenthesized subpattern overflowed and became
2122     negative, the calculation of the memory size went wrong. This could have
2123     led to memory overwriting.
2124    
2125     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2126    
2127     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2128     operating environments where this matters.
2129    
2130     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2131     PCRE options from within the C++ wrapper.
2132    
2133     5. Named capturing subpatterns were not being correctly counted when a pattern
2134     was compiled. This caused two problems: (a) If there were more than 100
2135     such subpatterns, the calculation of the memory needed for the whole
2136     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2137     back references of the form \12, where the number was greater than 9, were
2138     not recognized as back references, even though there were sufficient
2139     previous subpatterns.
2140    
2141     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2142     versions of gcc, e.g. 2.95.4.
2143    
2144    
2145 nigel 79 Version 6.1 21-Jun-05
2146     ---------------------
2147    
2148     1. There was one reference to the variable "posix" in pcretest.c that was not
2149     surrounded by "#if !defined NOPOSIX".
2150    
2151     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2152     the cross-check on the old pcre_info() function, for the benefit of the
2153     cut-down version of PCRE that is currently imported into Exim.
2154    
2155     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2156     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2157     patterns that start (?i) but I don't think that matters. The use of (?i) is
2158     just an example; this all applies to the other options as well.
2159    
2160     4. Since libtool seems to echo the compile commands it is issuing, the output
2161     from "make" can be reduced a bit by putting "@" in front of each libtool
2162     compile command.
2163    
2164     5. Patch from the folks at Google for configure.in to be a bit more thorough
2165     in checking for a suitable C++ installation before trying to compile the
2166     C++ stuff. This should fix a reported problem when a compiler was present,
2167     but no suitable headers.
2168    
2169     6. The man pages all had just "PCRE" as their title. I have changed them to
2170     be the relevant file name. I have also arranged that these names are
2171     retained in the file doc/pcre.txt, which is a concatenation in text format
2172     of all the man pages except the little individual ones for each function.
2173    
2174     7. The NON-UNIX-USE file had not been updated for the different set of source
2175     files that come with release 6. I also added a few comments about the C++
2176     wrapper.
2177    
2178    
2179 nigel 77 Version 6.0 07-Jun-05
2180     ---------------------
2181    
2182     1. Some minor internal re-organization to help with my DFA experiments.
2183    
2184     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2185     didn't matter for the library itself when fully configured, but did matter
2186     when compiling without UCP support, or within Exim, where the ucp files are
2187     not imported.
2188    
2189     3. Refactoring of the library code to split up the various functions into
2190     different source modules. The addition of the new DFA matching code (see
2191     below) to a single monolithic source would have made it really too
2192     unwieldy, quite apart from causing all the code to be include in a
2193     statically linked application, when only some functions are used. This is
2194     relevant even without the DFA addition now that patterns can be compiled in
2195     one application and matched in another.
2196    
2197     The downside of splitting up is that there have to be some external
2198     functions and data tables that are used internally in different modules of
2199     the library but which are not part of the API. These have all had their
2200     names changed to start with "_pcre_" so that they are unlikely to clash
2201     with other external names.
2202    
2203     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2204     a different (DFA) algorithm. Although it is slower than the original
2205     function, it does have some advantages for certain types of matching
2206     problem.
2207    
2208     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2209     including restarting after a partial match.
2210    
2211     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2212     defined when compiling for Windows was sent to me. I have put it into the
2213     code, though I have no means of testing or verifying it.
2214    
2215     7. Added the pcre_refcount() auxiliary function.
2216    
2217     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2218     match before or at the first newline in the subject string. In pcretest,
2219     the /f option on a pattern can be used to set this.
2220    
2221     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2222     would behave wrongly. This has been present in PCRE since release 4.0.
2223    
2224     10. A number of changes to the pcregrep command:
2225    
2226     (a) Refactored how -x works; insert ^(...)$ instead of setting
2227     PCRE_ANCHORED and checking the length, in preparation for adding
2228     something similar for -w.
2229    
2230     (b) Added the -w (match as a word) option.
2231    
2232     (c) Refactored the way lines are read and buffered so as to have more
2233     than one at a time available.
2234    
2235     (d) Implemented a pcregrep test script.
2236    
2237     (e) Added the -M (multiline match) option. This allows patterns to match
2238     over several lines of the subject. The buffering ensures that at least
2239     8K, or the rest of the document (whichever is the shorter) is available
2240     for matching (and similarly the previous 8K for lookbehind assertions).
2241    
2242     (f) Changed the --help output so that it now says
2243    
2244     -w, --word-regex(p)
2245    
2246     instead of two lines, one with "regex" and the other with "regexp"
2247     because that confused at least one person since the short forms are the
2248     same. (This required a bit of code, as the output is generated
2249     automatically from a table. It wasn't just a text change.)
2250    
2251     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2252     option but starts with a hyphen. Could be a pattern or a path name
2253     starting with a hyphen, for instance.
2254    
2255     (h) "-" can be given as a file name to represent stdin.
2256    
2257     (i) When file names are being printed, "(standard input)" is used for
2258     the standard input, for compatibility with GNU grep. Previously
2259     "<stdin>" was used.
2260    
2261     (j) The option --label=xxx can be used to supply a name to be used for
2262     stdin when file names are being printed. There is no short form.
2263    
2264     (k) Re-factored the options decoding logic because we are going to add
2265     two more options that take data. Such options can now be given in four
2266     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2267    
2268     (l) Added the -A, -B, and -C options for requesting that lines of context
2269     around matches be printed.
2270    
2271     (m) Added the -L option to print the names of files that do not contain
2272     any matching lines, that is, the complement of -l.
2273    
2274     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2275     continue to scan other files.
2276    
2277     (o) The -s option was incorrectly implemented. For compatibility with other
2278     greps, it now suppresses the error message for a non-existent or non-
2279     accessible file (but not the return code). There is a new option called
2280     -q that suppresses the output of matching lines, which was what -s was
2281     previously doing.
2282    
2283     (p) Added --include and --exclude options to specify files for inclusion
2284     and exclusion when recursing.
2285    
2286     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2287     Hopefully, it now does.
2288    
2289     12. Missing cast in pcre_study().
2290    
2291     13. Added an "uninstall" target to the makefile.
2292    
2293     14. Replaced "extern" in the function prototypes in Makefile.in with
2294     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2295     world, but is set differently for Windows.
2296    
2297     15. Added a second compiling function called pcre_compile2(). The only
2298     difference is that it has an extra argument, which is a pointer to an
2299     integer error code. When there is a compile-time failure, this is set
2300     non-zero, in addition to the error test pointer being set to point to an
2301     error message. The new argument may be NULL if no error number is required
2302     (but then you may as well call pcre_compile(), which is now just a
2303     wrapper). This facility is provided because some applications need a
2304     numeric error indication, but it has also enabled me to tidy up the way
2305     compile-time errors are handled in the POSIX wrapper.
2306    
2307     16. Added VPATH=.libs to the makefile; this should help when building with one
2308     prefix path and installing with another. (Or so I'm told by someone who
2309     knows more about this stuff than I do.)
2310    
2311     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2312     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2313     match everything, including newlines. This is not POSIX-compatible, but
2314     somebody wanted the feature. From pcretest it can be activated by using
2315     both the P and the s flags.
2316    
2317     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2318    
2319     19. libpcre.pc was being incorrectly installed as executable.
2320    
2321     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2322     it now also looks for '\r' so that it will work unmodified on Windows.
2323    
2324     21. Added Google's contributed C++ wrapper to the distribution.
2325    
2326     22. Added some untidy missing memory free() calls in pcretest, to keep
2327     Electric Fence happy when testing.
2328    
2329    
2330    
2331 nigel 75 Version 5.0 13-Sep-04
2332     ---------------------
2333    
2334     1. Internal change: literal characters are no longer packed up into items
2335     containing multiple characters in a single byte-string. Each character
2336     is now matched using a separate opcode. However, there may be more than one
2337     byte in the character in UTF-8 mode.
2338    
2339     2. The pcre_callout_block structure has two new fields: pattern_position and
2340     next_item_length. These contain the offset in the pattern to the next match
2341     item, and its length, respectively.
2342    
2343     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2344     insertion of callouts before each pattern item. Added the /C option to
2345     pcretest to make use of this.
2346    
2347     4. On the advice of a Windows user, the lines
2348    
2349     #if defined(_WIN32) || defined(WIN32)
2350     _setmode( _fileno( stdout ), 0x8000 );
2351     #endif /* defined(_WIN32) || defined(WIN32) */
2352    
2353     have been added to the source of pcretest. This apparently does useful
2354     magic in relation to line terminators.
2355    
2356     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2357     for the benefit of those environments where the "b" makes a difference.
2358    
2359     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2360     to know about it. I have put a hack into configure.in that adds in code
2361     to set GCC=yes if CC=icc. This seems to end up at a point in the
2362     generated configure script that is early enough to affect the setting of
2363     compiler options, which is what is needed, but I have no means of testing
2364     whether it really works. (The user who reported this had patched the
2365     generated configure script, which of course I cannot do.)
2366    
2367     LATER: After change 22 below (new libtool files), the configure script
2368     seems to know about icc (and also ecc). Therefore, I have commented out
2369     this hack in configure.in.
2370    
2371     7. Added support for pkg-config (2 patches were sent in).
2372    
2373     8. Negated POSIX character classes that used a combination of internal tables
2374     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2375     [[:^ascii]]. Typically, they would match almost any characters. The other
2376     POSIX classes were not broken in this way.
2377    
2378     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2379     to find the match, as PCRE was deluded into thinking that the match had to
2380     start at the start point or following a newline. The same bug applied to
2381     patterns with negative forward assertions or any backward assertions
2382     preceding ".*" at the start, unless the pattern required a fixed first
2383     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2384    
2385     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2386     starting at the last subject character, bytes beyond the end of the subject
2387     string were read.
2388    
2389     11. Renamed the variable "class" as "classbits" to make life easier for C++
2390     users. (Previously there was a macro definition, but it apparently wasn't
2391     enough.)
2392    
2393     12. Added the new field "tables" to the extra data so that tables can be passed
2394     in at exec time, or the internal tables can be re-selected. This allows
2395     a compiled regex to be saved and re-used at a later time by a different
2396     program that might have everything at different addresses.
2397    
2398     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2399     -R library as well as a -L library.
2400    
2401     14. The debugging options of pcretest (-d on the command line or D on a
2402     pattern) showed incorrect output for anything following an extended class
2403     that contained multibyte characters and which was followed by a quantifier.
2404    
2405     15. Added optional support for general category Unicode character properties
2406     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2407     support. It adds about 90K to the size of the library. The meanings of the
2408     inbuilt class escapes such as \d and \s have NOT been changed.
2409    
2410     16. Updated pcredemo.c to include calls to free() to release the memory for the
2411     compiled pattern.
2412    
2413     17. The generated file chartables.c was being created in the source directory
2414     instead of in the building directory. This caused the build to fail if the
2415     source directory was different from the building directory, and was
2416     read-only.
2417    
2418     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2419     file. No doubt somebody will tell me if they don't make sense... Also added
2420     Dan Mooney's comments about building on OpenVMS.
2421    
2422     19. Added support for partial matching via the PCRE_PARTIAL option for
2423     pcre_exec() and the \P data escape in pcretest.
2424    
2425     20. Extended pcretest with 3 new pattern features:
2426    
2427     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2428     write the compiled pattern to the file whose name is "rest-of-line".
2429     This is a straight binary dump of the data, with the saved pointer to
2430     the character tables forced to be NULL. The study data, if any, is
2431     written too. After writing, pcretest reads a new pattern.
2432    
2433     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2434     compiled pattern from the given file. There must not be any
2435     occurrences of "<" in the file name (pretty unlikely); if there are,
2436     pcretest will instead treat the initial "<" as a pattern delimiter.
2437     After reading in the pattern, pcretest goes on to read data lines as
2438     usual.
2439    
2440     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2441     and 16-bit fields in a compiled pattern, to simulate a pattern that
2442     was compiled on a host of opposite endianness.
2443    
2444     21. The pcre-exec() function can now cope with patterns that were compiled on
2445     hosts of opposite endianness, with this restriction:
2446    
2447     As for any compiled expression that is saved and used later, the tables
2448     pointer field cannot be preserved; the extra_data field in the arguments
2449     to pcre_exec() should be used to pass in a tables address if a value
2450     other than the default internal tables were used at compile time.
2451    
2452     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2453     now diagnosed as an error. Previously, most of the time, a negative number
2454     would have been treated as zero, but if in addition "ovector" was passed as
2455     NULL, a crash could occur.
2456    
2457     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2458     new versions from the libtool 1.5 distribution (the last one is a copy of
2459     a file called libtool.m4). This seems to have fixed the need to patch
2460     "configure" to support Darwin 1.3 (which I used to do). However, I still
2461     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2462     workstation).
2463    
2464     24. Changed the PCRE licence to be the more standard "BSD" licence.
2465    
2466    
2467 nigel 73 Version 4.5 01-Dec-03
2468     ---------------------
2469    
2470     1. There has been some re-arrangement of the code for the match() function so
2471     that it can be compiled in a version that does not call itself recursively.
2472     Instead, it keeps those local variables that need separate instances for
2473     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2474     needs to "recurse". Keeping track of where control must go is done by means
2475     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2476     hide most of the details from the main code, and operates only if
2477     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2478     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2479     operating.
2480    
2481     To make it easier for callers to provide specially tailored get/free
2482     functions for this usage, two new functions, pcre_stack_malloc, and
2483     pcre_stack_free, are used. They are always called in strict stacking order,
2484     and the size of block requested is always the same.
2485    
2486     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2487     PCRE has been compiled to use the stack or the heap for recursion. The
2488     -C option of pcretest uses this to show which version is compiled.
2489    
2490     A new data escape \S, is added to pcretest; it causes the amounts of store
2491     obtained and freed by both kinds of malloc/free at match time to be added
2492     to the output.
2493    
2494     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2495     what's available on my current Linux desktop machine.
2496    
2497     3. When matching a UTF-8 string, the test for a valid string at the start has
2498     been extended. If start_offset is not zero, PCRE now checks that it points
2499     to a byte that is the start of a UTF-8 character. If not, it returns
2500     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2501     this is necessary because there may be backward assertions in the pattern.
2502     When matching the same subject several times, it may save resources to use
2503     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2504    
2505     4. The code for checking the validity of UTF-8 strings has been tightened so
2506     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2507     containing "overlong sequences".
2508    
2509     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2510     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2511     should have been "&", but it just so happened that all the cases this let
2512     through by mistake were picked up later in the function.
2513    
2514     6. I had used a variable called "isblank" - this is a C99 function, causing
2515     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2516    
2517     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2518     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2519     so the version is shown; (c) stop "make test" echoing "./RunTest".
2520    
2521     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2522    
2523     9. The prototype for memmove() for systems that don't have it was using
2524     size_t, but the inclusion of the header that defines size_t was later. I've
2525     moved the #includes for the C headers earlier to avoid this.
2526    
2527     10. Added some adjustments to the code to make it easier to compiler on certain
2528     special systems:
2529    
2530     (a) Some "const" qualifiers were missing.
2531     (b) Added the macro EXPORT before all exported functions; by default this
2532     is defined to be empty.
2533     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2534     that it reads its output file name as an argument instead of writing
2535     to the standard output and assuming this can be redirected.
2536    
2537     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2538     class containing characters with values greater than 255, PCRE compilation
2539     went into a loop.
2540    
2541     12. A recursive reference to a subpattern that was within another subpattern
2542     that had a minimum quantifier of zero caused PCRE to crash. For example,
2543     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2544     recursion. If the recursively-called subpattern itself had a zero repeat,
2545     that was OK.
2546    
2547     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2548     buffer into which it was copied (for escape processing) was still set at
2549     1024, so long lines caused crashes.
2550    
2551     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2552     "internal error: code overflow...". This applied to any character class
2553     that was followed by a possessive quantifier.
2554    
2555     15. Modified the Makefile to add libpcre.la as a prerequisite for
2556     libpcreposix.la because I was told this is needed for a parallel build to
2557     work.
2558    
2559     16. If a pattern that contained .* following optional items at the start was
2560     studied, the wrong optimizing data was generated, leading to matching
2561     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2562     matching string must start with a or b or c. The correct conclusion for
2563     this pattern is that a match can start with any character.
2564    
2565    
2566 nigel 71 Version 4.4 13-Aug-03
2567     ---------------------
2568    
2569     1. In UTF-8 mode, a character class containing characters with values between
2570     127 and 255 was not handled correctly if the compiled pattern was studied.
2571     In fixing this, I have also improved the studying algorithm for such
2572     classes (slightly).
2573    
2574     2. Three internal functions had redundant arguments passed to them. Removal
2575     might give a very teeny performance improvement.
2576    
2577     3. Documentation bug: the value of the capture_top field in a callout is *one
2578     more than* the number of the hightest numbered captured substring.
2579    
2580     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2581     in incorrectly linking with a previously installed version. They now link
2582     explicitly with libpcre.la.
2583    
2584     5. configure.in no longer needs to recognize Cygwin specially.
2585    
2586     6. A problem in pcre.in for Windows platforms is fixed.
2587    
2588     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2589     pcretest, it used to include the size of the study block as part of its
2590     output. Unfortunately, the structure contains a field that has a different
2591     size on different hardware architectures. This meant that the tests that
2592     showed this size failed. As the block is currently always of a fixed size,
2593     this information isn't actually particularly useful in pcretest output, so
2594     I have just removed it.
2595    
2596     8. Three pre-processor statements accidentally did not start in column 1.
2597     Sadly, there are *still* compilers around that complain, even though
2598     standard C has not required this for well over a decade. Sigh.
2599    
2600     9. In pcretest, the code for checking callouts passed small integers in the
2601     callout_data field, which is a void * field. However, some picky compilers
2602     complained about the casts involved for this on 64-bit systems. Now
2603     pcretest passes the address of the small integer instead, which should get
2604     rid of the warnings.
2605    
2606     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2607     both compile and run time, and gives an error if an invalid UTF-8 sequence
2608     is found. There is a option for disabling this check in cases where the
2609     string is known to be correct and/or the maximum performance is wanted.
2610    
2611     11. In response to a bug report, I changed one line in Makefile.in from
2612    
2613     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2614     to
2615     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2616    
2617     to look similar to other lines, but I have no way of telling whether this
2618     is the right thing to do, as I do not use Windows. No doubt I'll get told
2619     if it's wrong...
2620    
2621    
2622 nigel 69 Version 4.3 21-May-03
2623     ---------------------
2624    
2625     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2626     Makefile.
2627    
2628     2. Some refactoring to improve the quality of the code:
2629    
2630     (i) The utf8_table... variables are now declared "const".
2631    
2632     (ii) The code for \cx, which used the "case flipping" table to upper case
2633     lower case letters, now just substracts 32. This is ASCII-specific,
2634     but the whole concept of \cx is ASCII-specific, so it seems
2635     reasonable.
2636    
2637     (iii) PCRE was using its character types table to recognize decimal and
2638     hexadecimal digits in the pattern. This is silly, because it handles
2639     only 0-9, a-f, and A-F, but the character types table is locale-
2640     specific, which means strange things might happen. A private
2641     table is now used for this - though it costs 256 bytes, a table is
2642     much faster than multiple explicit tests. Of course, the standard
2643     character types table is still used for matching digits in subject
2644     strings against \d.
2645    
2646     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2647     ending in _t are). So I've renamed it as ESC_tee.
2648    
2649     3. The first argument for regexec() in the POSIX wrapper should have been
2650     defined as "const".
2651    
2652     4. Changed pcretest to use malloc() for its buffers so that they can be
2653     Electric Fenced for debugging.
2654    
2655     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2656     to read one or more bytes before the start of the subject string. Often this
2657     had no effect on PCRE's behaviour, but in some circumstances it could
2658     provoke a segmentation fault.
2659    
2660     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2661     to try to read one or more bytes before the start of the subject string.
2662    
2663     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2664     UTF-8 support could misbehave in various ways if the subject string
2665     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2666     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2667     back over UTF-8 characters.)
2668    
2669    
2670 nigel 67 Version 4.2 14-Apr-03
2671     ---------------------
2672    
2673     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2674    
2675     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2676     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2677     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2678     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2679     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2680     and BUILD_EXEEXT
2681     Note: automatic setting of the BUILD variables is not yet working
2682     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2683     compile-time but not at link-time
2684     [LINK]: use for linking executables only
2685     make different versions for Windows and non-Windows
2686     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2687     libraries
2688     [LINK_FOR_BUILD]: new variable
2689     [OBJEXT]: use throughout
2690     [EXEEXT]: use throughout
2691     <winshared>: new target
2692     <wininstall>: new target
2693     <dftables.o>: use native compiler
2694     <dftables>: use native linker
2695     <install>: handle Windows platform correctly
2696     <clean>: ditto
2697     <check>: ditto
2698     copy DLL to top builddir before testing
2699    
2700     As part of these changes, -no-undefined was removed again. This was reported
2701     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2702     in any case.
2703    
2704     3. Some tidies to get rid of compiler warnings:
2705    
2706     . In the match_data structure, match_limit was an unsigned long int, whereas
2707     match_call_count was an int. I've made them both unsigned long ints.
2708    
2709     . In pcretest the fact that a const uschar * doesn't automatically cast to
2710     a void * provoked a warning.
2711    
2712     . Turning on some more compiler warnings threw up some "shadow" variables
2713     and a few more missing casts.
2714    
2715     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2716     option, a class that contained a single character with a value between 128
2717     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2718    
2719     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2720     option, a class that contained several characters, but with at least one
2721     whose value was between 128 and 255 caused PCRE to crash.
2722    
2723    
2724 nigel 65 Version 4.1 12-Mar-03
2725     ---------------------
2726 nigel 63
2727 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2728     needed, and a string in dftables.c that was longer than standard compilers are
2729     required to support.
2730    
2731     2. Compiling with Sun's compiler found a few more places where the code could
2732     be tidied up in order to avoid warnings.
2733    
2734     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2735     first of these names is deprecated in the latest Autoconf in favour of the name
2736     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2737     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2738     analogy I have changed it to CFLAGS_FOR_BUILD.
2739    
2740     4. Added -no-undefined to the linking command in the Makefile, because this is
2741     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2742     linking step for the pcreposix library.
2743    
2744     5. PCRE was failing to diagnose the case of two named groups with the same
2745     name.
2746    
2747     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2748     literal character that is needed in the subject for a match, and scans along to
2749     ensure that it is present before embarking on the full matching process. This
2750     saves time in cases of nested unlimited repeats that are never going to match.
2751     Problem: the scan can take a lot of time if the subject is very long (e.g.
2752     megabytes), thus penalizing straightforward matches. It is now done only if the
2753     amount of subject to be scanned is less than 1000 bytes.
2754    
2755     7. A lesser problem with the same optimization is that it was recording the
2756     first character of an anchored pattern as "needed", thus provoking a search
2757     right along the subject, even when the first match of the pattern was going to
2758     fail. The "needed" character is now not set for anchored patterns, unless it
2759     follows something in the pattern that is of non-fixed length. Thus, it still
2760     fulfils its original purpose of finding quick non-matches in cases of nested
2761     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2762    
2763    
2764     Version 4.0 17-Feb-03
2765     ---------------------
2766    
2767 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2768     extended to the end of string, PCRE compiled incorrect data. This could lead to
2769     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2770    
2771     2. Moved to autoconf 2.53 and libtool 1.4.2.
2772    
2773     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2774     the special perltest8 script is no longer needed - all the tests can be run
2775     from a single perltest script.
2776    
2777     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2778     by \s. It has now been removed in PCRE. This means it isn't recognized as
2779     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2780     class [:space:] *does* include VT, thereby creating a mess.
2781    
2782     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2783     space and tab.
2784    
2785     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2786     its new features into the main test script, reducing the number of scripts.
2787    
2788     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2789     were backward compatible, and made the (?i) apply to the whole pattern, as if
2790     /i were given. Now it behaves more logically, and applies the option setting
2791     only to what follows. PCRE has been changed to follow suit. However, if it
2792     finds options settings right at the start of the pattern, it extracts them into
2793     the global options, as before. Thus, they show up in the info data.
2794    
2795     8. Added support for the \Q...\E escape sequence. Characters in between are
2796     treated as literals. This is slightly different from Perl in that $ and @ are
2797     also handled as literals inside the quotes. In Perl, they will cause variable
2798     interpolation. Note the following examples:
2799    
2800     Pattern PCRE matches Perl matches
2801    
2802     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2803     \Qabc\$xyz\E abc\$xyz abc\$xyz
2804     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2805    
2806     For compatibility with Perl, \Q...\E sequences are recognized inside character
2807     classes as well as outside them.
2808    
2809     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2810     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2811     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2812     signed/unsigned warnings.
2813    
2814     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2815     option for pcretest, so I've replaced it by a simple function that does just
2816     that job.
2817    
2818     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2819     "pcregrep -".
2820    
2821     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2822     Java package. This provides some syntactic sugar for simple cases of what my
2823     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2824     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2825     item, you can use this simplified notation. Note that only makes sense with
2826     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2827     greediness, whatever the setting of the PCRE_UNGREEDY option.
2828    
2829     13. A change of greediness default within a pattern was not taking effect at
2830     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2831     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2832     was abstracted outside.
2833    
2834     14. PCRE now supports the \G assertion. It is true when the current matching
2835     position is at the start point of the match. This differs from \A when the
2836     starting offset is non-zero. Used with the /g option of pcretest (or similar
2837     code), it works in the same way as it does for Perl's /g option. If all
2838     alternatives of a regex begin with \G, the expression is anchored to the start
2839     match position, and the "anchored" flag is set in the compiled expression.
2840    
2841     15. Some bugs concerning the handling of certain option changes within patterns
2842     have been fixed. These applied to options other than (?ims). For example,
2843     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2844     been the other way round. Some of this was related to change 7 above.
2845    
2846     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2847     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2848     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2849     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2850    
2851     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2852     mode. Unlike ".", it always matches newline, whatever the setting of
2853     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2854     assertions. Perl allows it, but it doesn't (in general) work because it can't
2855     calculate the length of the lookbehind. At least, that's the case for Perl
2856     5.8.0 - I've been told they are going to document that it doesn't work in
2857     future.
2858    
2859     18. Added an error diagnosis for escapes that PCRE does not support: these are
2860     \L, \l, \N, \P, \p, \U, \u, and \X.
2861    
2862     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2863     reading past the end of the pattern in cases such as /[abcd/.
2864    
2865     20. PCRE was getting more memory than necessary for patterns with classes that
2866     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2867    
2868     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2869     compiling PCRE for use with Virtual Pascal.
2870    
2871     22. Small fix to the Makefile to make it work properly if the build is done
2872     outside the source tree.
2873    
2874     23. Added a new extension: a condition to go with recursion. If a conditional
2875     subpattern starts with (?(R) the "true" branch is used if recursion has
2876     happened, whereas the "false" branch is used only at the top level.
2877    
2878     24. When there was a very long string of literal characters (over 255 bytes
2879     without UTF support, over 250 bytes with UTF support), the computation of how
2880     much memory was required could be incorrect, leading to segfaults or other
2881     strange effects.
2882    
2883     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2884     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2885     there was a subsequent back reference to those brackets. This meant that, for
2886     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2887     possible to check for precisely this case. All we can do is abandon the
2888     optimization if .* occurs inside capturing brackets when there are any back
2889     references whatsoever. (See below for a better fix that came later.)
2890    
2891     26. The handling of the optimization for finding the first character of a
2892     non-anchored pattern, and for finding a character that is required later in the
2893     match were failing in some cases. This didn't break the matching; it just
2894     failed to optimize when it could. The way this is done has been re-implemented.
2895    
2896     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2897    
2898     28. Added a new feature that provides some of the functionality that Perl
2899     provides with (?{...}). The facility is termed a "callout". The way it is done
2900     in PCRE is for the caller to provide an optional function, by setting
2901     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2902     global variable. By default it is unset, which disables all calling out. To get
2903     the function called, the regex must include (?C) at appropriate points. This
2904     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2905     This provides a means of identifying different callout points. When PCRE
2906     reaches such a point in the regex, if pcre_callout has been set, the external
2907     function is called. It is provided with data in a structure called
2908     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2909     matching continues; if it returns a non-zero value, the match at the current
2910     point fails. However, backtracking will occur if possible. [This was changed
2911     later and other features added - see item 49 below.]
2912    
2913     29. pcretest is upgraded to test the callout functionality. It provides a
2914     callout function that displays information. By default, it shows the start of
2915     the match and the current position in the text. There are some new data escapes
2916     to vary what happens:
2917    
2918     \C+ in addition, show current contents of captured substrings
2919     \C- do not supply a callout function
2920     \C!n return 1 when callout number n is reached
2921     \C!n!m return 1 when callout number n is reached for the mth time
2922    
2923     30. If pcregrep was called with the -l option and just a single file name, it
2924     output "<stdin>" if a match was found, instead of the file name.
2925    
2926     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2927     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2928     pcre_exec(). This saves a malloc/free per call. The default value of
2929     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2930     when configuring.
2931    
2932     32. The default maximum size of a compiled pattern is 64K. There have been a
2933     few cases of people hitting this limit. The code now uses macros to handle the
2934     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2935     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2936     configuring. Tests 2 and 5 work only with 2-byte links because they output
2937     debugging information about compiled patterns.
2938    
2939     33. Internal code re-arrangements:
2940    
2941     (a) Moved the debugging function for printing out a compiled regex into
2942     its own source file (printint.c) and used #include to pull it into
2943     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2944     separate copies.
2945    
2946     (b) Defined the list of op-code names for debugging as a macro in
2947     internal.h so that it is next to the definition of the opcodes.
2948    
2949     (c) Defined a table of op-code lengths for simpler skipping along compiled
2950     code. This is again a macro in internal.h so that it is next to the
2951     definition of the opcodes.
2952    
2953     34. Added support for recursive calls to individual subpatterns, along the
2954     lines of Robin Houston's patch (but implemented somewhat differently).
2955    
2956     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2957     allow it to read and process whole directories in Win32. This code was
2958     contributed by Lionel Fourquaux; it has not been tested by me.
2959    
2960     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2961     used to name a group. Names consist of alphanumerics and underscores, and must
2962     be unique. Back references use the syntax (?P=name) and recursive calls use
2963     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2964     numbers. The function pcre_fullinfo() can be used after compilation to extract
2965     a name/number map. There are three relevant calls:
2966    
2967     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2968     PCRE_INFO_NAMECOUNT yields the number of entries
2969     PCRE_INFO_NAMETABLE yields a pointer to the map.
2970    
2971     The map is a vector of fixed-size entries. The size of each entry depends on
2972     the length of the longest name used. The first two bytes of each entry are the
2973     group number, most significant byte first. There follows the corresponding
2974     name, zero terminated. The names are in alphabetical order.
2975    
2976     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2977     case instead of 255. Making it the same both with and without UTF-8 support
2978     means that the same test output works with both.
2979    
2980     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2981     calling malloc() with a zero argument.
2982    
2983     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2984     optimization. I've improved things by keeping a bitmap of backreferences with
2985     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2986     fact referenced, the optimization can be applied. It is unlikely that a
2987     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2988     the match to follow \n) will appear inside brackets with a number greater than
2989     31, but if it does, any back reference > 31 suppresses the optimization.
2990    
2991     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2992     of disabling numbered capturing parentheses. Any opening parenthesis that is
2993     not followed by ? behaves as if it were followed by ?: but named parentheses
2994     can still be used for capturing (and they will acquire numbers in the usual
2995     way).
2996    
2997     41. Redesigned the return codes from the match() function into yes/no/error so
2998     that errors can be passed back from deep inside the nested calls. A malloc
2999     failure while inside a recursive subpattern call now causes the
3000     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3001    
3002     42. It is now possible to set a limit on the number of times the match()
3003     function is called in a call to pcre_exec(). This facility makes it possible to
3004     limit the amount of recursion and backtracking, though not in a directly
3005     obvious way, because the match() function is used in a number of different
3006     circumstances. The count starts from zero for each position in the subject
3007     string (for non-anchored patterns). The default limit is, for compatibility, a
3008     large number, namely 10 000 000. You can change this in two ways:
3009    
3010     (a) When configuring PCRE before making, you can use --with-match-limit=n
3011     to set a default value for the compiled library.
3012    
3013     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3014     a different value is set. See 45 below.
3015    
3016     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3017    
3018     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3019     of things that can be changed at compile time. The first argument specifies
3020     what is wanted and the second points to where the information is to be placed.
3021     The current list of available information is:
3022    
3023     PCRE_CONFIG_UTF8
3024    
3025     The output is an integer that is set to one if UTF-8 support is available;
3026     otherwise it is set to zero.
3027    
3028     PCRE_CONFIG_NEWLINE
3029    
3030     The output is an integer that it set to the value of the code that is used for
3031     newline. It is either LF (10) or CR (13).
3032    
3033     PCRE_CONFIG_LINK_SIZE
3034    
3035     The output is an integer that contains the number of bytes used for internal
3036     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3037    
3038     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3039    
3040     The output is an integer that contains the threshold above which the POSIX
3041     interface uses malloc() for output vectors. See item 31 above.
3042    
3043     PCRE_CONFIG_MATCH_LIMIT
3044    
3045     The output is an unsigned integer that contains the default limit of the number
3046     of match() calls in a pcre_exec() execution. See 42 above.
3047    
3048     44. pcretest has been upgraded by the addition of the -C option. This causes it
3049     to extract all the available output from the new pcre_config() function, and to
3050     output it. The program then exits immediately.
3051    
3052     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3053     order to support additional features. One way would have been to define
3054     pcre_exec2() (for example) with extra arguments, but this would not have been
3055     extensible, and would also have required all calls to the original function to
3056     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3057     is used for passing in "extra" data from pcre_study().
3058    
3059     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3060     contains the following fields:
3061    
3062     flags a bitmap indicating which of the following fields are set
3063     study_data opaque data from pcre_study()
3064     match_limit a way of specifying a limit on match() calls for a specific
3065     call to pcre_exec()
3066     callout_data data for callouts (see 49 below)
3067    
3068     The flag bits are also defined in pcre.h, and are
3069    
3070     PCRE_EXTRA_STUDY_DATA
3071     PCRE_EXTRA_MATCH_LIMIT
3072     PCRE_EXTRA_CALLOUT_DATA
3073    
3074     The pcre_study() function now returns one of these new pcre_extra blocks, with
3075     the actual study data pointed to by the study_data field, and the
3076     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3077     before. That is, this change is entirely upwards-compatible and requires no
3078     change to existing code.
3079    
3080     If you want to pass in additional data to pcre_exec(), you can either place it
3081     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3082     block.
3083    
3084     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3085     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3086     times with different match limits, until it finds the minimum value needed for
3087     pcre_exec() to complete. The value is then output. This can be instructive; for
3088     most simple matches the number is quite small, but for pathological cases it
3089     gets very large very quickly.
3090    
3091     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3092     returns the size of the data block pointed to by the study_data field in a
3093     pcre_extra block, that is, the value that was passed as the argument to
3094     pcre_malloc() when PCRE was getting memory in which to place the information
3095     created by pcre_study(). The fourth argument should point to a size_t variable.
3096     pcretest has been extended so that this information is shown after a successful
3097     pcre_study() call when information about the compiled regex is being displayed.
3098    
3099     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3100     because what follows is always an absolute path. (Later: it turns out that this
3101     is more than cosmetic for MinGW, because it doesn't like empty path
3102     components.)
3103    
3104     49. Some changes have been made to the callout feature (see 28 above):
3105    
3106     (i) A callout function now has three choices for what it returns:
3107    
3108     0 => success, carry on matching
3109     > 0 => failure at this point, but backtrack if possible
3110     < 0 => serious error, return this value from pcre_exec()
3111    
3112     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3113     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3114     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3115     use by callout functions. It will never be used by PCRE itself.
3116    
3117     (ii) The pcre_extra structure (see 45 above) has a void * field called
3118     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3119     pcre_callout_block structure has a field of the same name. The contents of
3120     the field passed in the pcre_extra structure are passed to the callout
3121     function in the corresponding field in the callout block. This makes it
3122     easier to use the same callout-containing regex from multiple threads. For
3123     testing, the pcretest program has a new data escape
3124    
3125     \C*n pass the number n (may be negative) as callout_data
3126    
3127     If the callout function in pcretest receives a non-zero value as
3128     callout_data, it returns that value.
3129    
3130     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3131     there were some redundant $(CFLAGS) in commands that are now specified as
3132     $(LINK), which already includes $(CFLAGS).
3133    
3134     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3135     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3136     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3137     one-byte characters throughout. Note that case-insensitive matching applies
3138     only to characters whose values are less than 256. PCRE doesn't support the
3139     notion of cases for higher-valued characters.
3140    
3141     (i) A character class whose characters are all within 0-255 is handled as
3142     a bit map, and the map is inverted for negative classes. Previously, a
3143     character > 255 always failed to match such a class; however it should
3144     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3145    
3146     (ii) A negated character class with a single character < 255 is coded as
3147     "not this character" (OP_NOT). This wasn't working properly when the test
3148     character was multibyte, either singly or repeated.
3149    
3150     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3151     mode, for example: \x{100}{2,3}.
3152    
3153     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3154     singly or repeated) now correctly test multibyte characters. However,
3155     PCRE doesn't recognize any characters with values greater than 255 as
3156     digits, spaces, or word characters. Such characters always match \D, \S,
3157     and \W, and never match \d, \s, or \w.
3158    
3159     (v) Classes may now contain characters and character ranges with values
3160     greater than 255. For example: [ab\x{100}-\x{400}].
3161    
3162     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3163     PCRE in UTF-8 mode.
3164    
3165     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3166     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3167     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3168     value.)
3169    
3170     53. The single man page has become too large. I have therefore split it up into
3171     a number of separate man pages. These also give rise to individual HTML pages;
3172     these are now put in a separate directory, and there is an index.html page that
3173     lists them all. Some hyperlinking between the pages has been installed.
3174    
3175     54. Added convenience functions for handling named capturing parentheses.
3176    
3177     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3178     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3179     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3180     are faulted.
3181    
3182     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3183     calling configure. These values are used when compiling the dftables.c program
3184     which is run to generate the source of the default character tables. They
3185     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3186     you will need to set these values.
3187    
3188     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3189    
3190    
3191     Version 3.9 02-Jan-02
3192 nigel 61 ---------------------
3193    
3194     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3195    
3196     2. If --disable-static was given, the building process failed when trying to
3197     build pcretest and pcregrep. (For some reason it was using libtool to compile
3198     them, which is not right, as they aren't part of the library.)
3199    
3200    
3201 nigel 59 Version 3.8 18-Dec-01
3202     ---------------------
3203    
3204     1. The experimental UTF-8 code was completely screwed up. It was packing the
3205     bytes in the wrong order. How dumb can you get?
3206    
3207    
3208 nigel 57 Version 3.7 29-Oct-01
3209     ---------------------
3210    
3211     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3212     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3213     this didn't happen under Solaris 8, where I normally test things.
3214    
3215 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3216     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3217     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3218     this fix an hour or so after the initial 3.7 release.)
3219 nigel 57
3220 nigel 59
3221 nigel 55 Version 3.6 23-Oct-01
3222     ---------------------
3223    
3224     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3225     offsets passed as NULL with zero offset count.
3226    
3227     2. The config.guess and config.sub files had not been updated when I moved to
3228     the latest autoconf.
3229    
3230    
3231 nigel 53 Version 3.5 15-Aug-01
3232     ---------------------
3233 nigel 5
3234 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3235     had been forgotten.
3236    
3237     2. By using declared but undefined structures, we can avoid using "void"
3238     definitions in pcre.h while keeping the internal definitions of the structures
3239     private.
3240    
3241     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3242     user point of view, this means that both static and shared libraries are built
3243     by default, but this can be individually controlled. More of the work of
3244     handling this static/shared cases is now inside libtool instead of PCRE's make
3245     file.
3246    
3247     4. The pcretest utility is now installed along with pcregrep because it is
3248     useful for users (to test regexs) and by doing this, it automatically gets
3249     relinked by libtool. The documentation has been turned into a man page, so
3250     there are now .1, .txt, and .html versions in /doc.
3251    
3252     5. Upgrades to pcregrep:
3253     (i) Added long-form option names like gnu grep.
3254     (ii) Added --help to list all options with an explanatory phrase.
3255     (iii) Added -r, --recursive to recurse into sub-directories.
3256     (iv) Added -f, --file to read patterns from a file.
3257    
3258     6. pcre_exec() was referring to its "code" argument before testing that
3259     argument for NULL (and giving an error if it was NULL).
3260    
3261     7. Upgraded Makefile.in to allow for compiling in a different directory from
3262     the source directory.
3263    
3264     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3265     options bits, the pointer it was passed was to an int instead of to an unsigned
3266     long int. This mattered only on 64-bit systems.
3267    
3268     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3269     generated) instead of pcre.in, which it its source. Also made the same change
3270     in several of the .c files.
3271    
3272     10. A new release of gcc defines printf() as a macro, which broke pcretest
3273     because it had an ifdef in the middle of a string argument for printf(). Fixed
3274     by using separate calls to printf().
3275    
3276     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3277     script, to force use of CR or LF instead of \n in the source. On non-Unix
3278     systems, the value can be set in config.h.
3279    
3280     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3281     absolute limit. Changed the text of the error message to make this clear, and
3282     likewise updated the man page.
3283    
3284     13. The limit of 99 on the number of capturing subpatterns has been removed.
3285     The new limit is 65535, which I hope will not be a "real" limit.
3286    
3287    
3288 nigel 51 Version 3.4 22-Aug-00
3289     ---------------------
3290    
3291     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3292    
3293     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3294    
3295    
3296 nigel 49 Version 3.3 01-Aug-00
3297     ---------------------
3298    
3299     1. If an octal character was given, but the value was greater than \377, it
3300     was not getting masked to the least significant bits, as documented. This could
3301     lead to crashes in some systems.
3302    
3303     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3304     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3305    
3306     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3307     These just pass their arguments on to (pcre_free)(), but they are provided
3308     because some uses of PCRE bind it to non-C systems that can call its functions,
3309     but cannot call free() or pcre_free() directly.
3310    
3311     4. Add "make test" as a synonym for "make check". Corrected some comments in
3312     the Makefile.
3313    
3314     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3315     Makefile.
3316    
3317     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3318     command called pgrep for grepping around the active processes.
3319    
3320     7. Added the beginnings of support for UTF-8 character strings.
3321    
3322     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3323     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3324     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3325     out for the ar command.)
3326    
3327    
3328 nigel 47 Version 3.2 12-May-00
3329     ---------------------
3330    
3331     This is purely a bug fixing release.
3332    
3333     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3334     of ZA. This was just one example of several cases that could provoke this bug,
3335     which was introduced by change 9 of version 2.00. The code for breaking
3336     infinite loops after an iteration that matches an empty string was't working
3337     correctly.
3338    
3339     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3340     when matched against abbab (for example). After matching an empty string, it
3341     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3342     caused it to match further down the string than it should.
3343    
3344     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3345     was there because it doesn't seem to be needed, and it causes trouble on some
3346     systems, as it is not a Standard C header. It has been removed.
3347    
3348     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3349     were reported on the Macintosh. The changes were from
3350    
3351     while ((c = *(++ptr)) != 0 && c != '\n');
3352     to
3353     while ((c = *(++ptr)) != 0 && c != '\n') ;
3354    
3355     Totally extraordinary, but if that's what it takes...
3356    
3357     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3358     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3359     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3360     assumes the way PCRE uses memmove() (always moving upwards).
3361    
3362     6. PCRE is being used in one environment where strchr() is not available. There
3363     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3364     faster code anyway.
3365    
3366    
3367 nigel 45 Version 3.1 09-Feb-00
3368     ---------------------
3369    
3370     The only change in this release is the fixing of some bugs in Makefile.in for
3371     the "install" target:
3372    
3373     (1) It was failing to install pcreposix.h.
3374    
3375     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3376    
3377    
3378 nigel 43 Version 3.0 01-Feb-00
3379     ---------------------
3380 nigel 41
3381     1. Add support for the /+ modifier to perltest (to output $` like it does in
3382     pcretest).
3383    
3384     2. Add support for the /g modifier to perltest.
3385    
3386     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3387     matches null strings.
3388    
3389     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3390     pattern. Perl treats empty patterns specially - it reuses the most recent
3391     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3392     effect.
3393    
3394     5. The POSIX interface was broken in that it was just handing over the POSIX
3395     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3396     required a bigger vector, with some working space on the end. This means that
3397     the POSIX wrapper now has to get and free some memory, and copy the results.
3398    
3399 nigel 43 6. Added some simple autoconf support, placing the test data and the
3400     documentation in separate directories, re-organizing some of the
3401     information files, and making it build pcre-config (a GNU standard). Also added
3402     libtool support for building PCRE as a shared library, which is now the
3403     default.
3404 nigel 41
3405 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3406     09 are not valid octal constants. Single digits will be used for minor values
3407     less than 10.
3408    
3409     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3410     existing programs that set these in the POSIX interface can use PCRE without
3411     modification.
3412    
3413     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3414     return all that pcre_info() returns, plus additional data. The pcre_info()
3415     function is retained for compatibility, but is considered to be obsolete.
3416    
3417     10. Added experimental recursion feature (?R) to handle one common case that
3418     Perl 5.6 will be able to do with (?p{...}).
3419    
3420     11. Added support for POSIX character classes like [:alpha:], which Perl is
3421     adopting.
3422    
3423    
3424 nigel 39 Version 2.08 31-Aug-99
3425     ----------------------
3426    
3427     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3428     trying to match at the startoffset position, but instead was moving forward to
3429     the next newline as if a previous match had failed.
3430    
3431     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3432     and could get into a loop if a null string was matched other than at the start
3433     of the subject.
3434    
3435     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3436     be distinguished at compile time, and for completeness also added PCRE_DATE.
3437    
3438     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3439     in GnuWin32 environments.
3440    
3441    
3442 nigel 37 Version 2.07 29-Jul-99
3443     ----------------------
3444    
3445     1. The documentation is now supplied in plain text form and HTML as well as in
3446     the form of man page sources.
3447    
3448     2. C++ compilers don't like assigning (void *) values to other pointer types.
3449     In particular this affects malloc(). Although there is no problem in Standard
3450     C, I've put in casts to keep C++ compilers happy.
3451    
3452     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3453     should be (const char *).
3454    
3455     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3456     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3457     However, I haven't made this a standard facility. The documentation doesn't
3458     mention it, and the Makefile doesn't support it.
3459    
3460     5. The Makefile now contains an "install" target, with editable destinations at
3461     the top of the file. The pcretest program is not installed.
3462    
3463     6. pgrep -V now gives the PCRE version number and date.
3464    
3465     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3466     causing the entire string to be ignored, instead of just the last character.
3467    
3468     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3469     non-matching string, it can take a very, very long time, even for strings of
3470     quite modest length, because of the nested recursion. PCRE now does better in
3471     some of these cases. It does this by remembering the last required literal
3472     character in the pattern, and pre-searching the subject to ensure it is present
3473     before running the real match. In other words, it applies a heuristic to detect
3474     some types of certain failure quickly, and in the above example, if presented
3475     with a string that has no trailing " it gives "no match" very quickly.
3476    
3477     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3478     other alternatives are tried instead.
3479    
3480    
3481 nigel 35 Version 2.06 09-Jun-99
3482     ----------------------
3483    
3484     1. Change pcretest's output for amount of store used to show just the code
3485     space, because the remainder (the data block) varies in size between 32-bit and
3486     64-bit systems.
3487    
3488     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3489     start matching at. This allows lookbehinds to work when searching for multiple
3490     occurrences in a string.
3491    
3492     3. Added additional options to pcretest for testing multiple occurrences:
3493    
3494     /+ outputs the rest of the string that follows a match
3495     /g loops for multiple occurrences, using the new startoffset argument
3496     /G loops for multiple occurrences by passing an incremented pointer
3497    
3498     4. PCRE wasn't doing the "first character" optimization for patterns starting
3499     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3500     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3501     the letter 'x'. On long subject strings, this gives a significant speed-up.
3502    
3503    
3504 nigel 33 Version 2.05 21-Apr-99
3505     ----------------------
3506    
3507     1. Changed the type of magic_number from int to long int so that it works
3508     properly on 16-bit systems.
3509    
3510     2. Fixed a bug which caused patterns starting with .* not to work correctly
3511     when the subject string contained newline characters. PCRE was assuming
3512     anchoring for such patterns in all cases, which is not correct because .* will
3513     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3514     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3515     must be retried after every newline in the subject.
3516    
3517    
3518 nigel 31 Version 2.04 18-Feb-99
3519     ----------------------
3520    
3521     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3522     computation of the store needed to hold the pattern was incorrect (too large).
3523     If such patterns were nested a few deep, this could multiply and become a real
3524     problem.
3525    
3526     2. Added /M option to pcretest to show the memory requirement of a specific
3527     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3528    
3529     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3530     compiled in such a way that the backtracking after subsequent failure was
3531     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3532     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3533    
3534    
3535 nigel 29 Version 2.03 02-Feb-99
3536     ----------------------
3537    
3538     1. Fixed typo and small mistake in man page.
3539    
3540 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3541     LICENCE file containing the conditions.
3542 nigel 29
3543     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3544     Perl, that is the internal \ allows the delimiter to be included in the
3545     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3546     the final delimiter, add \ to the end of the pattern (to test the error).
3547    
3548     4. Added the convenience functions for extracting substrings after a successful
3549     match. Updated pcretest to make it able to test these functions.
3550    
3551    
3552 nigel 27 Version 2.02 14-Jan-99
3553     ----------------------
3554    
3555     1. Initialized the working variables associated with each extraction so that
3556     their saving and restoring doesn't refer to uninitialized store.
3557    
3558     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3559     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3560     fix the problem.
3561    
3562     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3563     calls, and wasn't printing the correct value for compiling calls. Increased the
3564     default value of LOOPREPEAT, and the number of significant figures in the
3565     times.
3566    
3567     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3568    
3569     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3570     a building problem on Windows NT with a FAT file system.
3571    
3572    
3573 nigel 25 Version 2.01 21-Oct-98
3574     ----------------------
3575    
3576     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3577     to character tables built by pcre_maketables() in the current locale. If NULL
3578     is passed, the default tables are used.
3579    
3580    
3581 nigel 23 Version 2.00 24-Sep-98
3582 nigel 21 ----------------------
3583    
3584 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3585     it any more.
3586    
3587     2. Allow quantification of (?>) groups, and make it work correctly.
3588    
3589     3. The first character computation wasn't working for (?>) groups.
3590    
3591     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3592     end of the subject) and add 5.005's \z, which really does match only at the
3593     very end of the subject.
3594    
3595     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3596    
3597     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3598     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3599     localized options. All options to pcre_study() were also removed.
3600    
3601     7. Add other new features from 5.005:
3602    
3603     $(?<= positive lookbehind
3604     $(?<! negative lookbehind
3605     (?imsx-imsx) added the unsetting capability
3606     such a setting is global if at outer level; local otherwise
3607     (?imsx-imsx:) non-capturing groups with option setting
3608     (?(cond)re|re) conditional pattern matching
3609    
3610     A backreference to itself in a repeated group matches the previous
3611     captured string.
3612    
3613     8. General tidying up of studying (both automatic and via "study")
3614     consequential on the addition of new assertions.
3615    
3616     9. As in 5.005, unlimited repeated groups that could match an empty substring
3617     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3618     runtime if any iteration does actually match an empty substring.
3619    
3620     10. Include the RunTest script in the distribution.
3621    
3622     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3623     discrepancies, some of which were old and were also with respect to 5.004. They
3624     have now been fixed.
3625    
3626    
3627     Version 1.09 28-Apr-98
3628     ----------------------
3629    
3630 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3631     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3632     program crashes, or just wrong answers. This did not apply to negated classes
3633     containing more than one character, or to minima other than one.
3634    
3635    
3636 nigel 19 Version 1.08 27-Mar-98
3637     ----------------------
3638    
3639     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3640    
3641     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3642     latter must appear before anything that relies on it in the pattern.
3643    
3644    
3645 nigel 17 Version 1.07 16-Feb-98
3646     ----------------------
3647    
3648     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3649     repeat of a potentially empty string).
3650    
3651    
3652 nigel 15 Version 1.06 23-Jan-98
3653     ----------------------
3654    
3655     1. Added Markus Oberhumer's little patches for C++.
3656    
3657     2. Literal strings longer than 255 characters were broken.
3658    
3659    
3660 nigel 13 Version 1.05 23-Dec-97
3661     ----------------------
3662    
3663     1. Negated character classes containing more than one character were failing if
3664     PCRE_CASELESS was set at run time.
3665    
3666    
3667 nigel 11 Version 1.04 19-Dec-97
3668     ----------------------
3669    
3670     1. Corrected the man page, where some "const" qualifiers had been omitted.
3671    
3672     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3673     input syntax.
3674    
3675     3. Fixed memory leak which occurred when a regex with back references was
3676     matched with an offsets vector that wasn't big enough. The temporary memory
3677     that is used in this case wasn't being freed if the match failed.
3678    
3679     4. Tidied pcretest to ensure it frees memory that it gets.
3680    
3681     5. Temporary memory was being obtained in the case where the passed offsets
3682     vector was exactly big enough.
3683    
3684     6. Corrected definition of offsetof() from change 5 below.
3685    
3686     7. I had screwed up change 6 below and broken the rules for the use of
3687     setjmp(). Now fixed.
3688    
3689    
3690 nigel 9 Version 1.03 18-Dec-97
3691     ----------------------
3692    
3693     1. A erroneous regex with a missing opening parenthesis was correctly
3694     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3695     on some systems.
3696    
3697     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3698     it was reported that one broken compiler failed on the former because "code" is
3699     also an independent variable.
3700    
3701     3. The erroneous regex a[]b caused an array overrun reference.
3702    
3703     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3704     fail on data ending with that character. (It was going on too far, and checking
3705     the next character, typically a binary zero.) This was specific to the
3706     optimized code for single-character negative classes.
3707    
3708     5. Added a contributed patch from the TIN world which does the following:
3709    
3710     + Add an undef for memmove, in case the the system defines a macro for it.
3711    
3712     + Add a definition of offsetof(), in case there isn't one. (I don't know
3713     the reason behind this - offsetof() is part of the ANSI standard - but
3714     it does no harm).
3715    
3716     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3717     most of the places where whitespace preceded '#'. I have given up and
3718     allowed the remaining 2 cases to be at the margin.
3719    
3720     + Rename some variables in pcre to eliminate shadowing. This seems very
3721     pedantic, but does no harm, of course.
3722    
3723     6. Moved the call to setjmp() into its own function, to get rid of warnings
3724     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3725    
3726     7. Constructs such as \d{8,} were compiling into the equivalent of
3727 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3728 nigel 9 outcome, but in this particular case used more store than had been allocated,
3729     which caused the bug to be discovered because it threw up an internal error.
3730    
3731     8. The debugging code in both pcre and pcretest for outputting the compiled
3732     form of a regex was going wrong in the case of back references followed by
3733     curly-bracketed repeats.
3734    
3735    
3736 nigel 7 Version 1.02 12-Dec-97
3737     ----------------------
3738    
3739     1. Typos in pcre.3 and comments in the source fixed.
3740    
3741     2. Applied a contributed patch to get rid of places where it used to remove
3742     'const' from variables, and fixed some signed/unsigned and uninitialized
3743     variable warnings.
3744    
3745     3. Added the "runtest" target to Makefile.
3746    
3747     4. Set default compiler flag to -O2 rather than just -O.
3748    
3749    
3750 nigel 5 Version 1.01 19-Nov-97
3751     ----------------------
3752    
3753     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3754     like /([ab]*)*/, that is, for classes with more than one character in them.
3755    
3756     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3757     as /((?>a*))*/ (a PCRE_EXTRA facility).
3758    
3759    
3760     Version 1.00 18-Nov-97
3761     ----------------------
3762    
3763     1. Added compile-time macros to support systems such as SunOS4 which don't have
3764     memmove() or strerror() but have other things that can be used instead.
3765    
3766     2. Arranged that "make clean" removes the executables.
3767    
3768    
3769 nigel 3 Version 0.99 27-Oct-97
3770     ----------------------
3771    
3772     1. Fixed bug in code for optimizing classes with only one character. It was
3773     initializing a 32-byte map regardless, which could cause it to run off the end
3774     of the memory it had got.
3775    
3776     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3777    
3778    
3779     Version 0.98 22-Oct-97
3780     ----------------------
3781    
3782     1. Fixed bug in code for handling temporary memory usage when there are more
3783     back references than supplied space in the ovector. This could cause segfaults.
3784    
3785    
3786     Version 0.97 21-Oct-97
3787     ----------------------
3788    
3789     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3790    
3791     2. Optimized negated single characters not to use a bit map.
3792    
3793     3. Brought error texts together as macro definitions; clarified some of them;
3794     fixed one that was wrong - it said "range out of order" when it meant "invalid
3795     escape sequence".
3796    
3797     4. Changed some char * arguments to const char *.
3798    
3799     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3800    
3801     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3802     pcretest.
3803    
3804    
3805     Version 0.96 16-Oct-97
3806     ----------------------
3807    
3808     1. Added a simple "pgrep" utility to the distribution.
3809    
3810     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3811     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3812     where "ddd" means "one or more decimal digits".
3813    
3814     3. Fixed serious bug. If a pattern had a back reference, but the call to
3815     pcre_exec() didn't supply a large enough ovector to record the related
3816     identifying subpattern, the match always failed. PCRE now remembers the number
3817     of the largest back reference, and gets some temporary memory in which to save
3818     the offsets during matching if necessary, in order to ensure that
3819     backreferences always work.
3820    
3821     4. Increased the compatibility with Perl in a number of ways:
3822    
3823     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided