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Revision 531 - (hide annotations) (download)
Tue Jun 1 13:53:26 2010 UTC (4 years, 2 months ago) by ph10
File size: 188176 byte(s)
Check for running out of memory when using heap for recursion.

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