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Revision 544 - (hide annotations) (download)
Tue Jun 15 17:20:55 2010 UTC (4 years, 1 month ago) by ph10
File size: 189555 byte(s)
Fix forward reference in the presence of (?#( (open parens in comment).

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 535 Version 8.10 03-Jun-2010
5 ph10 510 ------------------------
6    
7 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
8 ph10 510 THEN.
9    
10 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
11 ph10 510
12 ph10 535 3. Inside a character class, \B is treated as a literal by default, but
13     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
14 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
15 ph10 535
16     4. Inside a character class, PCRE always treated \R and \X as literals,
17 ph10 513 whereas Perl faults them if its -w option is set. I have changed PCRE so
18     that it faults them when PCRE_EXTRA is set.
19 ph10 535
20 ph10 514 5. Added support for \N, which always matches any character other than
21     newline. (It is the same as "." when PCRE_DOTALL is not set.)
22 ph10 535
23 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
24 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
25 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
26 ph10 535 result to (void) does not stop the warnings; a more elaborate fudge is
27     needed. I've used a macro to implement this.
28 ph10 512
29 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
30    
31 ph10 517 8. Added four artifical Unicode properties to help with an option to make
32 ph10 518 \s etc use properties (see next item). The new properties are: Xan
33     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
34 ph10 535
35 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
36 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
37 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
38     REG_UCP to make it available via the POSIX interface.
39 ph10 513
40 ph10 535 10. Added --line-buffered to pcregrep.
41    
42     11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
43     studied, and the match started with a letter with a code point greater than
44 ph10 520 127 whose first byte was different to the first byte of the other case of
45 ph10 536 the letter, the other case of this starting letter was not recognized
46     (#976).
47 ph10 535
48 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
49 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
50 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
51     not have actually happened in practice until change 8 above was made (it
52 ph10 523 added property types that matched character-matching opcodes).
53 ph10 535
54 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
55 ph10 535 possible starting bytes for non-anchored patterns.
56    
57 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
58 ph10 535 \R, and also a number of cases that involve Unicode properties, both
59 ph10 532 explicit and implicit when PCRE_UCP is set.
60 ph10 529
61 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
62 ph10 535 input, it could crash or give wrong results if characters with values
63     greater than 0xc0 were present in the subject string. (Detail: it assumed
64 ph10 529 UTF-8 input when processing these items.)
65 ph10 535
66 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
67     size_t is 64-bit (#991).
68 ph10 535
69 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
70     --disable-stack-for-recursion (#990).
71    
72 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
73     the end, a newline was missing in the output.
74    
75 ph10 538 19. The default pcre_chartables.c file recognizes only ASCII characters (values
76     less than 128) in its various bitmaps. However, there is a facility for
77     generating tables according to the current locale when PCRE is compiled. It
78     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
79     characters, are recognized by isspace() and therefore were getting set in
80 ph10 541 these tables, and indeed these tables seem to approximate to ISO 8859. This
81     caused a problem in UTF-8 mode when pcre_study() was used to create a list
82     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
83     which of course cannot start UTF-8 characters. I have changed the code so
84     that only real ASCII characters (less than 128) and the correct starting
85     bytes for UTF-8 encodings are set for characters greater than 127 when in
86     UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
87     altogether.)
88    
89     20. Added the /T option to pcretest so as to be able to run tests with non-
90     standard character tables, thus making it possible to include the tests
91     used for 19 above in the standard set of tests.
92 ph10 544
93     21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
94     reference to a subpattern the other side of a comment that contains an
95     opening parenthesis caused either an internal compiling error, or a
96     reference to the wrong subpattern.
97 ph10 517
98 ph10 520
99 ph10 508 Version 8.02 19-Mar-2010
100 ph10 491 ------------------------
101    
102     1. The Unicode data tables have been updated to Unicode 5.2.0.
103    
104 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
105     configured.
106 ph10 507
107 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
108 ph10 507 original author of that file, following a query about its status.
109    
110     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
111 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
112 ph10 507
113 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
114     quantifier applied to a forward-referencing subroutine call, could compile
115     incorrect code or give the error "internal error: previously-checked
116     referenced subpattern not found".
117 ph10 507
118     6. Both MS Visual Studio and Symbian OS have problems with initializing
119 ph10 497 variables to point to external functions. For these systems, therefore,
120     pcre_malloc etc. are now initialized to local functions that call the
121     relevant global functions.
122 ph10 507
123 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
124     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
125 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
126     the lengths are correct (equal to the number of opcodes).
127    
128     8. Following on from 7, I added a similar kludge to check the length of the
129     eint vector in pcreposix.c.
130    
131     9. Error texts for pcre_compile() are held as one long string to avoid too
132     much relocation at load time. To find a text, the string is searched,
133 ph10 499 counting zeros. There was no check for running off the end of the string,
134     which could happen if a new error number was added without updating the
135 ph10 507 string.
136    
137     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
138    
139 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
140 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
141     \K is "not well defined" if used in an assertion. PCRE now accepts it if
142     the assertion is positive, but not if it is negative.
143    
144 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
145 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
146     implementation of support for (*MARK) will need an extra pointer on the
147 ph10 501 stack; I have reserved it now, so that the stack frame size does not
148     decrease.
149 ph10 507
150     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
151     item in branch that calls a recursion is a subroutine call - as in the
152 ph10 503 second branch in the above example - was incorrectly given the compile-
153     time error "recursive call could loop indefinitely" because pcre_compile()
154 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
155    
156 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
157 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
158 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
159 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
160 ph10 491
161 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
162 ph10 492
163 ph10 507
164 ph10 489 Version 8.01 19-Jan-2010
165     ------------------------
166 ph10 471
167     1. If a pattern contained a conditional subpattern with only one branch (in
168 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
169 ph10 473 computed the wrong minimum data length (which is of course zero for such
170 ph10 489 subpatterns). This could cause incorrect "no match" results.
171 ph10 473
172     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
173 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
174     "internal error: code overflow at offset...". This happened only when
175 ph10 473 the reset was to the original external option setting. (An optimization
176     abstracts leading options settings into an external setting, which was the
177 ph10 472 cause of this.)
178 ph10 471
179 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
180     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
181     assertion pattern did not match (meaning that the assertion was true), it
182     was incorrectly treated as false if the SKIP had been reached during the
183     matching. This also applied to assertions used as conditions.
184 ph10 471
185 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
186     assertion subpattern, including such a pattern used as a condition,
187     unpredictable results occurred, instead of the error return
188     PCRE_ERROR_DFA_UITEM.
189 ph10 478
190 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
191     situation when an empty string is matched. It now does the fancy magic
192 ph10 478 stuff that is necessary.
193    
194     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
195 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
196 ph10 478
197 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
198     as part of something else:
199 ph10 478
200     (a) Change DEBUG to PCRE_DEBUG.
201    
202     (b) In pcre_compile(), rename the member of the "branch_chain" structure
203     called "current" as "current_branch", to prevent a collision with the
204 ph10 475 Linux macro when compiled as a kernel module.
205 ph10 478
206     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
207     prevent a collision with the Linux macro when compiled as a kernel
208 ph10 475 module.
209 ph10 478
210 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
211     cast potentially large values to (double). This has been changed to that
212 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
213     instead, thus avoiding the use of floating point arithmetic. (There is no
214     other use of FP in PCRE.) If int64_t is not found, the fallback is to
215     double.
216    
217     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
218 ph10 476 2005 (difference between two addresses compared to an unsigned value).
219 ph10 473
220 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
221     custom one, because of the following reported problem in Windows:
222 ph10 473
223 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
224 ph10 489 under Win32.
225 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
226 ph10 489 therefore missing the function definition.
227 ph10 478 - The compiler thus generates a "C" signature for the test function.
228     - The linker fails to find the "C" function.
229     - PCRE fails to configure if asked to do so against libbz2.
230 ph10 486
231 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
232     messages were output:
233 ph10 478
234 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
235     rerunning libtoolize, to keep the correct libtool macros in-tree.
236     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
237 ph10 486
238 ph10 479 I have done both of these things.
239 ph10 486
240 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
241 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
242     runaway infinite recursion. I updated the discussion in the pcrestack man
243     page.
244    
245     13. Now that we have gone to the x.xx style of version numbers, the minor
246     version may start with zero. Using 08 or 09 is a bad idea because users
247     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
248     interpreted as invalid octal numbers. I've updated the previous comment in
249     configure.ac, and also added a check that gives an error if 08 or 09 are
250 ph10 481 used.
251 ph10 486
252 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
253 ph10 483 causing partial matching to fail when the end of the subject matched \W
254     in a UTF-8 pattern where \W was quantified with a minimum of 3.
255 ph10 486
256 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
257 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
258 ph10 483 their definitions. The declarations used "const uschar *" and the
259     definitions used USPTR. Even though USPTR is normally defined as "const
260     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
261     reported that: "This difference in casting confuses some C++ compilers, for
262     example, SunCC recognizes above declarations as different functions and
263 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
264 ph10 483 USPTR.
265 ph10 486
266     16. GNU libtool is named differently on some systems. The autogen.sh script now
267 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
268     (FreeBSD).
269 ph10 478
270 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
271     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
272     comment: "Figure out how to create a longlong from a string: strtoll and
273     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
274     instance, but it only takes 2 args instead of 3!"
275 ph10 479
276 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
277     specification, with a corresponding code fix. A pattern such as
278     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
279     refers, was giving matches when it shouldn't. For example, xa=xaaa would
280     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
281     same bug. Such groups have to be quantified to be useful, or contained
282     inside another quantified group. (If there's no repetition, the reference
283     can never match.) The problem arises because, having left the group and
284     moved on to the rest of the pattern, a later failure that backtracks into
285     the group uses the captured value from the final iteration of the group
286     rather than the correct earlier one. I have fixed this in PCRE by forcing
287     any group that contains a reference to itself to be an atomic group; that
288     is, there cannot be any backtracking into it once it has completed. This is
289     similar to recursive and subroutine calls.
290 ph10 486
291 ph10 488
292 ph10 469 Version 8.00 19-Oct-09
293 ph10 418 ----------------------
294    
295     1. The table for translating pcre_compile() error codes into POSIX error codes
296 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
297     being within the table. This could lead to an OK return being given in
298 ph10 418 error.
299 ph10 461
300     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
301     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
302     in a Windows environment.
303    
304 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
305     zero, as does GNU grep. However, pcregrep was also printing all files when
306     --files-with-matches was added. Now, when both options are given, it prints
307     counts only for those files that have at least one match. (GNU grep just
308 ph10 461 prints the file name in this circumstance, but including the count seems
309     more useful - otherwise, why use --count?) Also ensured that the
310 ph10 420 combination -clh just lists non-zero counts, with no names.
311 ph10 461
312     4. The long form of the pcregrep -F option was incorrectly implemented as
313     --fixed_strings instead of --fixed-strings. This is an incompatible change,
314     but it seems right to fix it, and I didn't think it was worth preserving
315     the old behaviour.
316    
317     5. The command line items --regex=pattern and --regexp=pattern were not
318 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
319 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
320 ph10 422 which are compatible with GNU grep; these now work.
321 ph10 461
322     6. No libpcreposix.pc file was created for pkg-config; there was just
323 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
324 ph10 461
325 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
326 ph10 461 when UCP support is not needed, by modifying the Python script that
327 ph10 425 generates it from Unicode data files. This should not matter if the module
328     is correctly used as a library, but I received one complaint about 50K of
329     unwanted data. My guess is that the person linked everything into his
330     program rather than using a library. Anyway, it does no harm.
331 ph10 461
332 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
333 ph10 461 was a minimum greater than 1 for a wide character in a possessive
334 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
335     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
336     character. Chaos in the form of incorrect output or a compiling loop could
337     result.
338 ph10 461
339 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
340 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
341 ph10 426 partially matched by this function. In addition, if there are at least two
342 ph10 435 slots in the offset vector, the offset of the earliest inspected character
343     for the match and the offset of the end of the subject are set in them when
344 ph10 461 PCRE_ERROR_PARTIAL is returned.
345    
346 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
347     synonymous with PCRE_PARTIAL, for backwards compatibility, and
348     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
349 ph10 462 and may be more useful for multi-segment matching.
350 ph10 461
351     11. Partial matching with pcre_exec() is now more intuitive. A partial match
352     used to be given if ever the end of the subject was reached; now it is
353     given only if matching could not proceed because another character was
354     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
355     string "Z", which now yields "no match" instead of "partial match". In the
356     case of pcre_dfa_exec(), "no match" is given if every matching path for the
357     final character ended with (*FAIL).
358    
359 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
360 ph10 461 if the pattern had a "must contain" character that was already found in the
361 ph10 428 earlier partial match, unless partial matching was again requested. For
362     example, with the pattern /dog.(body)?/, the "must contain" character is
363     "g". If the first part-match was for the string "dog", restarting with
364 ph10 435 "sbody" failed. This bug has been fixed.
365 ph10 461
366     13. The string returned by pcre_dfa_exec() after a partial match has been
367     changed so that it starts at the first inspected character rather than the
368     first character of the match. This makes a difference only if the pattern
369     starts with a lookbehind assertion or \b or \B (\K is not supported by
370     pcre_dfa_exec()). It's an incompatible change, but it makes the two
371 ph10 435 matching functions compatible, and I think it's the right thing to do.
372 ph10 461
373 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
374 ph10 461 so that the demonstration program is easily available in environments where
375     PCRE has not been installed from source.
376    
377 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
378 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
379     library.
380 ph10 461
381 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
382 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
383 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
384 ph10 433 these options useful.
385 ph10 461
386     17. If a caller to the POSIX matching function regexec() passes a non-zero
387 ph10 438 value for nmatch with a NULL value for pmatch, the value of
388 ph10 461 nmatch is forced to zero.
389    
390 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
391 ph10 461 the diff command, as RunTest does. It now checks in the same way as
392 ph10 437 RunTest, and also checks for the -b option.
393 ph10 461
394 ph10 438 19. If an odd number of negated classes containing just a single character
395     interposed, within parentheses, between a forward reference to a named
396 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
397     an internal error, complaining that it could not find the referenced
398 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
399 ph10 461 [The bug was that it was starting one character too far in when skipping
400     over the character class, thus treating the ] as data rather than
401     terminating the class. This meant it could skip too much.]
402    
403 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
404 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
405 ph10 442 to have an empty string match not at the start, even when the pattern is
406 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
407    
408 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
409 ph10 461 than the maximum at the outer level, the higher number was returned, but
410     with unset values at the outer level. The correct (outer level) value is
411 ph10 446 now given.
412 ph10 461
413 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
414     PCRE did not set those parentheses (unlike Perl). I have now found a way to
415     make it do so. The string so far is captured, making this feature
416     compatible with Perl.
417 ph10 461
418     23. The tests have been re-organized, adding tests 11 and 12, to make it
419 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
420 ph10 461
421 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
422 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
423     does. Neither allows recursion.
424    
425     25. I finally figured out how to implement a request to provide the minimum
426     length of subject string that was needed in order to match a given pattern.
427     (It was back references and recursion that I had previously got hung up
428     on.) This code has now been added to pcre_study(); it finds a lower bound
429 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
430     bound, but using it to avoid searching strings that are too short does give
431     some useful speed-ups. The value is available to calling programs via
432     pcre_fullinfo().
433 ph10 461
434 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
435     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
436     study optimizations had never been tested with that matching function.
437     Oops. What is worse, even when it was passed study data, there was a bug in
438     pcre_dfa_exec() that meant it never actually used it. Double oops. There
439     were also very few tests of studied patterns with pcre_dfa_exec().
440 ph10 461
441 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
442     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
443     on the other side of the coin, they are no longer allowed to have different
444     names, because these cannot be distinguished in PCRE, and this has caused
445     confusion. (This is a difference from Perl.)
446 ph10 461
447     28. When duplicate subpattern names are present (necessarily with different
448     numbers, as required by 27 above), and a test is made by name in a
449     conditional pattern, either for a subpattern having been matched, or for
450     recursion in such a pattern, all the associated numbered subpatterns are
451 ph10 459 tested, and the overall condition is true if the condition is true for any
452     one of them. This is the way Perl works, and is also more like the way
453     testing by number works.
454 ph10 418
455 ph10 461
456 ph10 412 Version 7.9 11-Apr-09
457 ph10 376 ---------------------
458    
459 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
460 ph10 376 (pcretest), all targets were linked against these libraries. This included
461     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
462     libraries. This caused unwanted dependencies to be created. This problem
463 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
464 ph10 376 pcretest is linked with readline.
465 ph10 392
466 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
467     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
468     moved outside it again, because FALSE and TRUE are already defined in AIX,
469     but BOOL is not.
470 ph10 392
471     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
472 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
473 ph10 392
474 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
475     hyphens) following file names and line numbers when outputting matching
476 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
477 ph10 376 wording for the --colour (or --color) option.
478 ph10 392
479 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
480     was not coloured; this is different to GNU grep, so I have changed it to be
481     the same.
482 ph10 392
483 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
484 ph10 392 each matching line was coloured. Now it goes on to look for further matches
485     of any of the test patterns, which is the same behaviour as GNU grep.
486    
487     7. A pattern that could match an empty string could cause pcregrep to loop; it
488     doesn't make sense to accept an empty string match in pcregrep, so I have
489 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
490     seems to be how GNU grep behaves.
491 ph10 392
492 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
493 ph10 392 start or after a newline", because the conditional assertion was not being
494     correctly handled. The rule now is that both the assertion and what follows
495     in the first alternative must satisfy the test.
496    
497 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
498 ph10 399 condition was an assertion, PCRE could crash during matching, both with
499     pcre_exec() and pcre_dfa_exec().
500 ph10 392
501     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
502     used for matching.
503    
504     11. Unicode property support in character classes was not working for
505 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
506 ph10 388
507 ph10 392 12. Added the -M command line option to pcretest.
508    
509 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
510 ph10 389
511     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
512 ph10 390
513 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
514 ph10 390 wrapper.
515 ph10 392
516 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
517 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
518 ph10 391 string constants.
519 ph10 405
520 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
521     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
522 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
523     these, but not everybody uses configure.
524    
525     19. A conditional group that had only one branch was not being correctly
526     recognized as an item that could match an empty string. This meant that an
527     enclosing group might also not be so recognized, causing infinite looping
528     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
529     with the subject "ab", where knowledge that the repeated group can match
530 ph10 396 nothing is needed in order to break the loop.
531 ph10 405
532 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
533 ph10 405 exec(), but without supplying a callout function, matching went wrong.
534    
535     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
536     leak if the size of the offset vector was greater than 30. When the vector
537     is smaller, the saved offsets during recursion go onto a local stack
538     vector, but for larger vectors malloc() is used. It was failing to free
539     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
540 ph10 400 error, in fact).
541 ph10 405
542 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
543 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
544     problem, but was untidy.
545 ph10 376
546 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
547     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
548     included within another project.
549 ph10 411
550 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
551     slightly modified by me:
552 ph10 411
553     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
554     not building pcregrep.
555    
556 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
557 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
558    
559 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
560     duplicate group numbers, could behave incorrectly or give incorrect errors,
561     because when scanning forward to find the reference group, PCRE was not
562     taking into account the duplicate group numbers. A pattern such as
563     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
564 ph10 411
565     26. Changed a few more instances of "const unsigned char *" to USPTR, making
566     the feature of a custom pointer more persuasive (as requested by a user).
567 ph10 416
568 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
569 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
570     pre-defined.
571 ph10 392
572 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
573    
574 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
575     in the configuration summary.
576 ph10 405
577 ph10 411
578 ph10 374 Version 7.8 05-Sep-08
579 ph10 349 ---------------------
580    
581     1. Replaced UCP searching code with optimized version as implemented for Ad
582     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
583 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
584     to 5 times on some simple patterns that I tested. Permission was given to
585     distribute the MultiStage2.py script that generates the tables (it's not in
586     the tarball, but is in the Subversion repository).
587 ph10 349
588 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
589     scripts.
590 ph10 358
591 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
592     a group with a zero qualifier. The result of the study could be incorrect,
593 ph10 358 or the function might crash, depending on the pattern.
594    
595     4. Caseless matching was not working for non-ASCII characters in back
596 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
597 ph10 358 It now works when Unicode Property Support is available.
598    
599 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
600     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
601     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
602 ph10 358 truncation.
603 ph10 349
604 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
605    
606 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
607     pointers, in case they are 64-bit values.
608 ph10 371
609     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
610     test 2 if it fails.
611    
612 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
613 ph10 371 and a #define of that name to empty if it is not externally set. This is to
614     allow users of MSVC to set it if necessary.
615    
616     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
617 ph10 359 the convenience functions in the pcre_get.c source file.
618 ph10 371
619 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
620     could cause overwriting and/or a crash. This command provoked a crash in
621 ph10 371 some environments:
622    
623     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
624    
625 ph10 360 This potential security problem was recorded as CVE-2008-2371.
626 ph10 371
627 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
628     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
629 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
630 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
631     pcretest so that it places the subject at the end of its malloc-ed buffer.
632 ph10 371
633 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
634 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
635    
636 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
637 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
638     first line. This applied both to normal and DFA matching.
639    
640 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
641 ph10 371 /^[^d]*?$/8 failed to match "abc".
642 ph10 351
643 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
644    
645     17. Make it more clear in the documentation that values returned from
646 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
647 ph10 357
648 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
649 ph10 368
650 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
651     supplied by Stefan Weber. I made a further small update for 7.8 because
652 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
653     replaced by pcre_ucd.c.
654 ph10 371
655 ph10 373
656 ph10 347 Version 7.7 07-May-08
657 ph10 321 ---------------------
658    
659     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
660 ph10 345 a string to a long long, pretend we don't even have a long long." This is
661 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
662 ph10 345
663 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
664     pre-7.6 versions, which defined a global no_arg variable instead of putting
665 ph10 332 it in the RE class. (See also #8 below.)
666 ph10 345
667     3. Remove a line of dead code, identified by coverity and reported by Nuno
668     Lopes.
669    
670 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
671 ph10 321
672 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
673 ph10 345 of files, instead of just to the final components.
674    
675 ph10 324 (2) If there was more than one level of directory, the subdirectories were
676     skipped unless they satisfied the include/exclude conditions. This is
677     inconsistent with GNU grep (and could even be seen as contrary to the
678     pcregrep specification - which I improved to make it absolutely clear).
679     The action now is always to scan all levels of directory, and just
680     apply the include/exclude patterns to regular files.
681 ph10 345
682 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
683 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
684    
685 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
686 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
687 ph10 326 doesn't support NULs in patterns.
688 ph10 345
689     7. Added some missing "const"s to declarations of static tables in
690     pcre_compile.c and pcre_dfa_exec.c.
691    
692 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
693 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
694 ph10 345 first patch. And a third patch - this was a messy problem.)
695 ph10 321
696 ph10 345 9. Applied Craig's patch to remove the use of push_back().
697    
698 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
699     matching function regexec().
700 ph10 345
701     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
702     which, however, unlike Perl's \g{...}, are subroutine calls, not back
703 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
704     Oniguruma does).
705 ph10 345
706     12. Previously, a group with a zero repeat such as (...){0} was completely
707 ph10 335 omitted from the compiled regex. However, this means that if the group
708     was called as a subroutine from elsewhere in the pattern, things went wrong
709 ph10 345 (an internal error was given). Such groups are now left in the compiled
710     pattern, with a new opcode that causes them to be skipped at execution
711 ph10 335 time.
712 ph10 345
713 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
714     to the way PCRE behaves:
715 ph10 345
716 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
717 ph10 345
718     (b) A back reference to an unmatched subpattern matches an empty string
719 ph10 336 (Perl fails the current match path).
720 ph10 345
721 ph10 341 (c) A data ] in a character class must be notated as \] because if the
722 ph10 345 first data character in a class is ], it defines an empty class. (In
723 ph10 341 Perl it is not possible to have an empty class.) The empty class []
724     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
725     The negative empty class [^] matches any one character, independently
726     of the DOTALL setting.
727 ph10 345
728     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
729 ph10 340 non-existent subpattern following a character class starting with ']' and
730     containing () gave an internal compiling error instead of "reference to
731     non-existent subpattern". Fortunately, when the pattern did exist, the
732 ph10 345 compiled code was correct. (When scanning forwards to check for the
733 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
734 ph10 345 the class, so got the count wrong. When actually compiling, the reference
735 ph10 340 was subsequently set up correctly.)
736 ph10 345
737 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
738 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
739     other assertions are supported. I have made pcre_dfa_exec() support
740     (*FAIL).
741    
742 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
743 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
744     cannot be changed at match time, I realized I could make a small
745     improvement to matching performance by compiling OP_ALLANY instead of
746     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
747     on the OP_ANY path.
748    
749     17. Compiling pcretest on Windows with readline support failed without the
750 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
751 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
752    
753 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
754 ph10 345 ncurses library to be included for pcretest when ReadLine support is
755     requested, but also to allow for it to be overridden. This patch came from
756     Daniel Bergström.
757 ph10 347
758 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
759 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
760     any errors with the current Unicode tables. Thanks to Peter Kankowski for
761     spotting this.
762 ph10 324
763 ph10 332
764 ph10 319 Version 7.6 28-Jan-08
765 ph10 300 ---------------------
766    
767 ph10 302 1. A character class containing a very large number of characters with
768     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
769     overflow.
770 ph10 309
771     2. Patch to cut out the "long long" test in pcrecpp_unittest when
772     HAVE_LONG_LONG is not defined.
773    
774 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
775 ph10 304 bring them up to date and include new features. This patch includes:
776 ph10 309
777 ph10 304 - Fixed PH's badly added libz and libbz2 support.
778     - Fixed a problem with static linking.
779 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
780 ph10 304 - Fixed dftables problem and added an option.
781     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
782     HAVE_LONG_LONG.
783     - Added readline support for pcretest.
784 ph10 309 - Added an listing of the option settings after cmake has run.
785    
786 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
787     "pcre.dll" under mingw when using Configure/Make. I added stuff to
788     Makefile.am that cause it to include this special target, without
789     affecting anything else. Note that the same mingw target plus all
790     the other distribution libraries and programs are now supported
791     when configuring with CMake (see 6 below) instead of with
792     Configure/Make.
793 ph10 309
794 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
795     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
796 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
797     solves the problem, but it does no harm.
798 ph10 313
799 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
800 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
801 ph10 314 with CMake, and also correct the comment about stack recursion.
802 ph10 313
803 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
804 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
805     of a program that users should build themselves after PCRE is installed, so
806     building it automatically is not really right. What is more, it gave
807 ph10 312 trouble in some build environments.
808 ph10 300
809 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
810 ph10 308
811 ph10 319
812 ph10 298 Version 7.5 10-Jan-08
813 ph10 263 ---------------------
814    
815     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
816     values in parens when parsing an RE using the C++ wrapper."
817 ph10 286
818 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
819     Characters greater than 255 were excluded from the class instead of being
820     included.
821 ph10 286
822     3. The same bug as (2) above applied to negated POSIX classes such as
823 ph10 265 [:^space:].
824 ph10 286
825 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
826     defined or documented. It seems to have been a typo for PCRE_STATIC, so
827 ph10 286 I have changed it.
828    
829 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
830 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
831     first named subpattern whose name started with "a" (in other words, the
832 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
833     expected" is now given for (?&) (a zero-length name), and this patch also
834     makes it give the same error for \k'' (previously it complained that that
835     was a reference to a non-existent subpattern).
836 ph10 286
837 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
838 ph10 286 this is right because (?- can be followed by option settings as well as by
839 ph10 269 digits. I have, however, made the messages clearer.
840 ph10 286
841 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
842     than the number used in the conditional) now cause a compile-time error.
843     This is actually not compatible with Perl, which accepts such patterns, but
844     treats the conditional as always being FALSE (as PCRE used to), but it
845     seems to me that giving a diagnostic is better.
846 ph10 286
847 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
848 ph10 275 and messages.
849 ph10 286
850     9. Fix two occurrences of "backslash" in comments that should have been
851     "backspace".
852    
853     10. Remove two redundant lines of code that can never be obeyed (their function
854     was moved elsewhere).
855    
856     11. The program that makes PCRE's Unicode character property table had a bug
857     which caused it to generate incorrect table entries for sequences of
858 ph10 277 characters that have the same character type, but are in different scripts.
859 ph10 286 It amalgamated them into a single range, with the script of the first of
860 ph10 277 them. In other words, some characters were in the wrong script. There were
861     thirteen such cases, affecting characters in the following ranges:
862 ph10 286
863 ph10 277 U+002b0 - U+002c1
864     U+0060c - U+0060d
865 ph10 286 U+0061e - U+00612
866 ph10 277 U+0064b - U+0065e
867     U+0074d - U+0076d
868     U+01800 - U+01805
869     U+01d00 - U+01d77
870     U+01d9b - U+01dbf
871     U+0200b - U+0200f
872     U+030fc - U+030fe
873     U+03260 - U+0327f
874     U+0fb46 - U+0fbb1
875     U+10450 - U+1049d
876 ph10 286
877 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
878     compatible with GNU grep in that, if there was more than one match in a
879     line, it showed only the first of them. It now behaves in the same way as
880     GNU grep.
881 ph10 286
882     13. If the -o and -v options were combined for pcregrep, it printed a blank
883     line for every non-matching line. GNU grep prints nothing, and pcregrep now
884     does the same. The return code can be used to tell if there were any
885     non-matching lines.
886    
887 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
888    
889     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
890 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
891 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
892     and both kinds of lookbehind were skipped).
893    
894 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
895 ph10 284 inclusion of <windows.h> to before rather than after the definition of
896     INVALID_FILE_ATTRIBUTES (patch from David Byron).
897 ph10 263
898 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
899 ph10 286 character property caused pcre_compile() to compile bad code, which led at
900     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
901     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
902     caused the error; without that there was no problem.
903 ph10 263
904 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
905 ph10 286
906 ph10 289 19. Added --enable-pcretest-libreadline.
907 ph10 286
908 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
909 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
910 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
911     later patch that removed the other one (the right fix) and added unit tests
912     that check the return values (which was not done before).
913 ph10 292
914 ph10 291 21. Several CMake things:
915 ph10 287
916 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
917 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
918 ph10 288
919 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
920     linked with the newly-built libraries, not previously installed ones.
921 ph10 291
922 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
923 ph10 298
924     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
925     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
926     UTF-8 newline character). The key issue is that the pattern starts .*;
927     this means that the match must be either at the beginning, or after a
928     newline. The bug was in the code for advancing after a failed match and
929     checking that the new position followed a newline. It was not taking
930 ph10 294 account of UTF-8 characters correctly.
931 ph10 298
932     23. PCRE was behaving differently from Perl in the way it recognized POSIX
933     character classes. PCRE was not treating the sequence [:...:] as a
934     character class unless the ... were all letters. Perl, however, seems to
935     allow any characters between [: and :], though of course it rejects as
936     unknown any "names" that contain non-letters, because all the known class
937     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
938     for example, whereas PCRE did not - it did not recognize a POSIX character
939     class. This seemed a bit dangerous, so the code has been changed to be
940     closer to Perl. The behaviour is not identical to Perl, because PCRE will
941     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
942     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
943     Perl does, and where it didn't before.
944    
945 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
946     Windows environments %n is disabled by default.
947 ph10 292
948    
949 ph10 260 Version 7.4 21-Sep-07
950 ph10 230 ---------------------
951    
952     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
953 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
954     LF". That isn't really right - the whole point of the change was to try to
955     help when there was an actual mention of one of the two characters. So now
956     the change happens only if \r or \n (or a literal CR or LF) character is
957 ph10 230 encountered.
958 ph10 231
959     2. The 32-bit options word was also used for 6 internal flags, but the numbers
960     of both had grown to the point where there were only 3 bits left.
961     Fortunately, there was spare space in the data structure, and so I have
962     moved the internal flags into a new 16-bit field to free up more option
963 ph10 230 bits.
964 ph10 231
965     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
966     but did not set the internal JCHANGED flag - either of these is enough to
967     control the way the "get" function works - but the PCRE_INFO_JCHANGED
968     facility is supposed to tell if (?J) was ever used, so now (?J) at the
969 ph10 230 start sets both bits.
970    
971 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
972     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
973 ph10 230
974 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
975    
976     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
977 ph10 233 compatibility, even though it is no longer used.
978 ph10 243
979     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
980 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
981 ph10 259 windows.h file is present (where different names are used). [This was
982 ph10 257 reversed later after testing - see 16 below.]
983 ph10 243
984     8. Changed all #include <config.h> to #include "config.h". There were also
985 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
986 ph10 243
987 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
988 ph10 243 sequence off the lines that it output.
989    
990     10. It was pointed out to me that arrays of string pointers cause lots of
991     relocations when a shared library is dynamically loaded. A technique of
992     using a single long string with a table of offsets can drastically reduce
993     these. I have refactored PCRE in four places to do this. The result is
994 ph10 240 dramatic:
995 ph10 243
996 ph10 240 Originally: 290
997     After changing UCP table: 187
998 ph10 243 After changing error message table: 43
999 ph10 240 After changing table of "verbs" 36
1000     After changing table of Posix names 22
1001 ph10 243
1002 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
1003 ph10 247
1004 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1005 ph10 247 unicode-properties was also set.
1006    
1007 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1008 ph10 231
1009 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1010     checked only for CRLF.
1011 ph10 233
1012 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
1013    
1014 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1015 ph10 253
1016 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1017 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1018     entirely. This removes changes made in 7 above.
1019 ph10 256
1020 ph10 261 17. The CMake files have been updated, and there is now more information about
1021     building with CMake in the NON-UNIX-USE document.
1022 ph10 257
1023 ph10 261
1024 ph10 228 Version 7.3 28-Aug-07
1025 ph10 157 ---------------------
1026    
1027 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1028     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1029     brackets there is not right, since it causes compilers to look for an
1030     installed pcre.h, not the version that is in the source that is being
1031     compiled (which of course may be different). I have changed it back to:
1032 ph10 197
1033 ph10 189 #include "pcre.h"
1034 ph10 197
1035     I have a vague recollection that the change was concerned with compiling in
1036     different directories, but in the new build system, that is taken care of
1037     by the VPATH setting the Makefile.
1038    
1039 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1040     when the subject happened to end in the byte 0x85 (e.g. if the last
1041     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1042     characters but of course it shouldn't be taken as a newline when it is part
1043     of another character. The bug was that, for an unlimited repeat of . in
1044     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1045     characters when looking for a newline.
1046 ph10 197
1047     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1048    
1049     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1050     in debug output.
1051    
1052 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1053     long printing in the pcrecpp unittest when running under MinGW.
1054 ph10 189
1055 ph10 197 6. ESC_K was left out of the EBCDIC table.
1056 ph10 189
1057 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1058     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1059     limit also applies to "virtual nesting" when a pattern is recursive, and in
1060     this case 1000 isn't so big. I have been able to remove this limit at the
1061     expense of backing off one optimization in certain circumstances. Normally,
1062     when pcre_exec() would call its internal match() function recursively and
1063     immediately return the result unconditionally, it uses a "tail recursion"
1064     feature to save stack. However, when a subpattern that can match an empty
1065     string has an unlimited repetition quantifier, it no longer makes this
1066     optimization. That gives it a stack frame in which to save the data for
1067     checking that an empty string has been matched. Previously this was taken
1068     from the 1000-entry workspace that had been reserved. So now there is no
1069     explicit limit, but more stack is used.
1070 ph10 189
1071 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1072     syntax that is required for Windows, and which was going wrong for the
1073     pcreposix and pcrecpp parts of the library. These were overlooked when this
1074     problem was solved for the main library.
1075 ph10 197
1076 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1077     the size of patterns that contain repeated groups with explicit upper
1078     limits. As the maximum quantifier is 65535, the maximum group length was
1079     set at 30,000 so that the product of these two numbers did not overflow a
1080     32-bit integer. However, it turns out that people want to use groups that
1081     are longer than 30,000 bytes (though not repeat them that many times).
1082     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1083     made it possible to implement the integer overflow checks in a much more
1084     dynamic way, which I have now done. The artificial limitation on group
1085     length has been removed - we now have only the limit on the total length of
1086     the compiled pattern, which depends on the LINK_SIZE setting.
1087 ph10 208
1088     10. Fixed a bug in the documentation for get/copy named substring when
1089     duplicate names are permitted. If none of the named substrings are set, the
1090     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1091     empty string.
1092    
1093     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1094     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1095     because the ] is interpreted as the first data character and the
1096     terminating ] is not found. PCRE has been made compatible with Perl in this
1097     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1098     cause memory overwriting.
1099    
1100 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1101     string has been matched (to stop an infinite loop). It was not recognizing
1102 ph10 208 a conditional subpattern that could match an empty string if that
1103 ph10 206 subpattern was within another subpattern. For example, it looped when
1104 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1105 ph10 206 condition was not nested. This bug has been fixed.
1106 ph10 208
1107 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1108     past the start of the subject in the presence of bytes with the top bit
1109     set, for example "\x8aBCD".
1110 ph10 211
1111 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1112     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1113 ph10 200
1114 ph10 211 14. Optimized (?!) to (*FAIL).
1115 ph10 202
1116 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1117     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1118     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1119     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1120     does: it's just the validity check that is more restrictive.
1121 ph10 220
1122     16. Inserted checks for integer overflows during escape sequence (backslash)
1123     processing, and also fixed erroneous offset values for syntax errors during
1124     backslash processing.
1125    
1126 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1127 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1128    
1129 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1130     caused an overrun.
1131 ph10 220
1132     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1133     something other than just ASCII characters) inside a group that had an
1134     unlimited repeat caused a loop at compile time (while checking to see
1135     whether the group could match an empty string).
1136    
1137 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1138     [\P{Any}] did so. (Error in the code for printing property names.)
1139 ph10 210
1140 ph10 220 21. An orphan \E inside a character class could cause a crash.
1141    
1142     22. A repeated capturing bracket such as (A)? could cause a wild memory
1143 ph10 218 reference during compilation.
1144 ph10 220
1145     23. There are several functions in pcre_compile() that scan along a compiled
1146     expression for various reasons (e.g. to see if it's fixed length for look
1147 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1148 ph10 220 present in the pattern. These operators have additional parameters compared
1149     with \d, etc, and these were not being taken into account when moving along
1150 ph10 218 the compiled data. Specifically:
1151 ph10 220
1152     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1153     length.
1154    
1155     (b) An item such as \pL+ within a repeated group could cause crashes or
1156 ph10 218 loops.
1157 ph10 220
1158 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1159 ph10 220 "reference to non-existent subpattern" error.
1160    
1161 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1162    
1163 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1164 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1165 ph10 211
1166 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1167 ph10 218
1168 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1169 ph10 223 character were causing crashes (broken optimization).
1170 ph10 227
1171 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1172 ph10 227 \p or \P) caused a compile-time loop.
1173    
1174 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1175     break. For example, the unstudied pattern [\r\n]A does not match the string
1176     "\r\nA" because change 7.0/46 below moves the current point on by two
1177     characters after failing to match at the start. However, the pattern \nA
1178 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1179     the same is true. There doesn't seem any very clean way out of this, but
1180     what I have chosen to do makes the common cases work: PCRE now takes note
1181     of whether there can be an explicit match for \r or \n anywhere in the
1182     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1183     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1184     pattern has explicit CR or LF references.
1185 ph10 222
1186 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1187 ph10 223
1188 ph10 227
1189 ph10 189 Version 7.2 19-Jun-07
1190     ---------------------
1191    
1192 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1193     which is apparently normally available under Windows.
1194 ph10 159
1195     2. Re-jig the pcregrep tests with different newline settings in an attempt
1196     to make them independent of the local environment's newline setting.
1197 ph10 157
1198 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1199 ph10 165
1200 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1201     was not 2, because the output contained actual offsets. The recent new
1202 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1203     usable with all link sizes.
1204    
1205 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1206     stack recursion. This gives a massive performance boost under BSD, but just
1207 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1208 ph10 164 in all cases.
1209 ph10 172
1210 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1211 ph10 172
1212 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1213     recursion call. It refers to the nth most recently opened parentheses.
1214 ph10 172
1215 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1216 ph10 172 to be opened parentheses.
1217    
1218     (c) Conditions that refer to capturing parentheses can be specified
1219 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1220 ph10 172
1221 ph10 168 (d) \K resets the start of the current match so that everything before
1222 ph10 172 is not part of it.
1223    
1224 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1225 ph10 172
1226 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1227 ph10 172 reference syntax.
1228 ph10 182
1229 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1230 ph10 182 alternative starts with the same number.
1231 ph10 172
1232 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1233    
1234 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1235     PCRE_INFO_JCHANGED.
1236    
1237     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1238     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1239 ph10 170 for detecting groups that can match an empty string.
1240 ph10 159
1241 ph10 172 9. A pattern with a very large number of alternatives (more than several
1242     hundred) was running out of internal workspace during the pre-compile
1243     phase, where pcre_compile() figures out how much memory will be needed. A
1244     bit of new cunning has reduced the workspace needed for groups with
1245     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1246     workspace instead of running out of the 4096 that are available.
1247 ph10 182
1248 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1249 ph10 172
1250 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1251     The report of the bug said:
1252 ph10 182
1253 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1254     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1255 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1256 ph10 185
1257 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1258 ph10 185 it matched the wrong number of bytes.
1259 ph10 172
1260 ph10 179
1261 ph10 155 Version 7.1 24-Apr-07
1262 ph10 98 ---------------------
1263    
1264 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1265 ph10 122 that is more "standard", making use of automake and other Autotools. There
1266 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1267     on this.
1268 ph10 111
1269     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1270     for recursive directory scanning broke on some systems because the files
1271     are not scanned in any specific order and on different systems the order
1272     was different. A call to "sort" has been inserted into RunGrepTest for the
1273     approprate test as a short-term fix. In the longer term there may be an
1274 ph10 100 alternative.
1275 ph10 111
1276 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1277 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1278     people do their own conversions for various reasons). The problems
1279     concerned the use of low-level troff macros .br and .in. I have therefore
1280     removed all such uses from the man pages (some were redundant, some could
1281 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1282     HTML has been updated to handle .nf/.fi and to complain if it encounters
1283     .br or .in.
1284 ph10 111
1285 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1286 ph10 123 arranged for config.h to be included in the distribution, with the name
1287 ph10 111 config.h.generic, for the benefit of those who have to compile without
1288     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1289    
1290     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1291     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1292 ph10 127 makevp.bat for the current PCRE, using the additional files
1293 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1294 ph10 111
1295     6. A Windows user reported a minor discrepancy with test 2, which turned out
1296     to be caused by a trailing space on an input line that had got lost in his
1297 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1298 ph10 111
1299 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1300 ph10 111 that is needed.
1301    
1302 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1303     as "const" (a) because they are and (b) because it helps the PHP
1304     maintainers who have recently made a script to detect big data structures
1305 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1306     to update Builducptable as well, so it won't revert if ucptable.h is ever
1307 ph10 105 re-created.
1308 ph10 111
1309     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1310 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1311 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1312     support is not required. This saves 1.5-2K of code, which is important in
1313 ph10 107 some applications.
1314 ph10 111
1315 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1316 ph10 111 so as not to refer to the tables, even though these functions will never be
1317     called when UTF-8 support is disabled. Otherwise there are problems with a
1318     shared library.
1319    
1320 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1321    
1322     (a) It was defining its arguments as char * instead of void *.
1323    
1324 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1325     a long time ago when I wrote it, but is no longer the case.
1326    
1327 ph10 118 The emulated memove() is provided for those environments that have neither
1328 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1329 ph10 118 is clearly not the case, as these two bugs were recently reported.
1330 ph10 123
1331 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1332 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1333     pages, and it removes trailing spaces from listed files. It also creates
1334     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1335     case, it wraps all the #defines with #ifndefs. This script should be run
1336 ph10 111 before "make dist".
1337 ph10 123
1338 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1339     with Unicode property support.
1340 ph10 123
1341     (a) For a maximizing quantifier, if the two different cases of the
1342     character were of different lengths in their UTF-8 codings (there are
1343     some cases like this - I found 11), and the matching function had to
1344 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1345     were both the same length.
1346 ph10 123
1347     (b) When PCRE was configured to use the heap rather than the stack for
1348     recursion during matching, it was not correctly preserving the data for
1349     the other case of a UTF-8 character when checking ahead for a match
1350     while processing a minimizing repeat. If the check also involved
1351 ph10 115 matching a wide character, but failed, corruption could cause an
1352     erroneous result when trying to check for a repeat of the original
1353     character.
1354 ph10 123
1355 ph10 116 13. Some tidying changes to the testing mechanism:
1356 ph10 98
1357 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1358     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1359 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1360     this for UTF-8.) The configure.ac script no longer substitutes the
1361     relevant variables.
1362    
1363 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1364     with length and offset values. This means that the output is different
1365     for different internal link sizes. Test 2 is skipped for link sizes
1366     other than 2 because of this, bypassing the problem. Unfortunately,
1367     there was also a test in test 3 (the locale tests) that used /B and
1368 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1369     I have added a new /Z option to pcretest that replaces the length and
1370     offset values with spaces. This is now used to make test 3 independent
1371 ph10 122 of link size. (Test 2 will be tidied up later.)
1372 ph10 123
1373     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1374 ph10 122 segmentation fault instead of returning the appropriate error message.
1375 ph10 134
1376 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1377 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1378     This doesn't seem right; it now treats the CRLF combination as the line
1379     ending, and so does not match in that case. It's only a pattern such as ^$
1380     that would hit this one: something like ^ABC$ would have failed after \r
1381     and then tried again after \r\n.
1382    
1383 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1384 ph10 134 in an attempt to make files that differ only in their line terminators
1385     compare equal. This works on Linux.
1386 ph10 142
1387 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1388     as it exited. This is now fixed, thanks to valgrind.
1389 ph10 142
1390 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1391 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1392     was because its rules for how to advance for /g after matching an empty
1393 ph10 143 string at the end of a line did not allow for this case. They now check for
1394     it specially.
1395 ph10 150
1396     20. pcretest is supposed to handle patterns and data of any length, by
1397     extending its buffers when necessary. It was getting this wrong when the
1398 ph10 147 buffer for a data line had to be extended.
1399 ph10 150
1400 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1401 ph10 150 CRLF as a newline sequence.
1402 ph10 152
1403 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1404 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1405     I have nevertheless tidied it up.
1406 ph10 111
1407 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1408 ph10 123
1409 ph10 153 24. Added a man page for pcre-config.
1410 ph10 152
1411 ph10 153
1412 nigel 93 Version 7.0 19-Dec-06
1413     ---------------------
1414    
1415     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1416     moving to gcc 4.1.1.
1417    
1418     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1419     sys/time.h, which is documented as needed for this function. It doesn't
1420     seem to matter on Linux, but it showed up on some releases of OS X.
1421    
1422     3. It seems that there are systems where bytes whose values are greater than
1423     127 match isprint() in the "C" locale. The "C" locale should be the
1424     default when a C program starts up. In most systems, only ASCII printing
1425     characters match isprint(). This difference caused the output from pcretest
1426     to vary, making some of the tests fail. I have changed pcretest so that:
1427    
1428     (a) When it is outputting text in the compiled version of a pattern, bytes
1429     other than 32-126 are always shown as hex escapes.
1430    
1431     (b) When it is outputting text that is a matched part of a subject string,
1432     it does the same, unless a different locale has been set for the match
1433     (using the /L modifier). In this case, it uses isprint() to decide.
1434    
1435     4. Fixed a major bug that caused incorrect computation of the amount of memory
1436     required for a compiled pattern when options that changed within the
1437     pattern affected the logic of the preliminary scan that determines the
1438     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1439     that the computed length was too small. The symptoms of this bug were
1440     either the PCRE error "internal error: code overflow" from pcre_compile(),
1441     or a glibc crash with a message such as "pcretest: free(): invalid next
1442     size (fast)". Examples of patterns that provoked this bug (shown in
1443     pcretest format) are:
1444    
1445     /(?-x: )/x
1446     /(?x)(?-x: \s*#\s*)/
1447     /((?i)[\x{c0}])/8
1448     /(?i:[\x{c0}])/8
1449    
1450     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1451     is now done differently.
1452    
1453     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1454     wrapper classes; (b) implement a new function in the C++ scanner that is
1455     more efficient than the old way of doing things because it avoids levels of
1456     recursion in the regex matching; (c) add a paragraph to the documentation
1457     for the FullMatch() function.
1458    
1459     6. The escape sequence \n was being treated as whatever was defined as
1460     "newline". Not only was this contrary to the documentation, which states
1461     that \n is character 10 (hex 0A), but it also went horribly wrong when
1462     "newline" was defined as CRLF. This has been fixed.
1463    
1464     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1465     was being set to -1 for the "end of line" case (supposedly a value that no
1466     character can have). Though this value is never used (the check for end of
1467     line is "zero bytes in current character"), it caused compiler complaints.
1468     I've changed it to 0xffffffff.
1469    
1470     8. In pcre_version.c, the version string was being built by a sequence of
1471     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1472     string (as it is for production releases) called a macro with an empty
1473     argument. The C standard says the result of this is undefined. The gcc
1474     compiler treats it as an empty string (which was what was wanted) but it is
1475     reported that Visual C gives an error. The source has been hacked around to
1476     avoid this problem.
1477    
1478     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1479     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1480     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1481     of them did).
1482    
1483     10. Originally, pcretest opened its input and output without "b"; then I was
1484     told that "b" was needed in some environments, so it was added for release
1485     5.0 to both the input and output. (It makes no difference on Unix-like
1486     systems.) Later I was told that it is wrong for the input on Windows. I've
1487     now abstracted the modes into two macros, to make it easier to fiddle with
1488     them, and removed "b" from the input mode under Windows.
1489    
1490     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1491    
1492     12. Added -help and --help to pcretest as an official way of being reminded
1493     of the options.
1494    
1495     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1496     and pcrecpp.cc because they annoy compilers at high warning levels.
1497    
1498     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1499    
1500     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1501     scripts are not C programs :-) and which was not noticed because it works
1502     on Linux.
1503    
1504     16. pcretest is supposed to handle any length of pattern and data line (as one
1505     line or as a continued sequence of lines) by extending its input buffer if
1506     necessary. This feature was broken for very long pattern lines, leading to
1507     a string of junk being passed to pcre_compile() if the pattern was longer
1508     than about 50K.
1509    
1510     17. I have done a major re-factoring of the way pcre_compile() computes the
1511     amount of memory needed for a compiled pattern. Previously, there was code
1512     that made a preliminary scan of the pattern in order to do this. That was
1513     OK when PCRE was new, but as the facilities have expanded, it has become
1514     harder and harder to keep it in step with the real compile phase, and there
1515     have been a number of bugs (see for example, 4 above). I have now found a
1516     cunning way of running the real compile function in a "fake" mode that
1517     enables it to compute how much memory it would need, while actually only
1518     ever using a few hundred bytes of working memory and without too many
1519     tests of the mode. This should make future maintenance and development
1520     easier. A side effect of this work is that the limit of 200 on the nesting
1521     depth of parentheses has been removed (though this was never a serious
1522     limitation, I suspect). However, there is a downside: pcre_compile() now
1523     runs more slowly than before (30% or more, depending on the pattern). I
1524     hope this isn't a big issue. There is no effect on runtime performance.
1525    
1526     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1527     newline (only possible for the last line of a file) and it was a
1528     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1529    
1530     19. Added additional timing features to pcretest. (1) The -tm option now times
1531     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1532     separate command line item, by a number that specifies the number of
1533     repeats to use when timing. The default is 50000; this gives better
1534     precision, but takes uncomfortably long for very large patterns.
1535    
1536     20. Extended pcre_study() to be more clever in cases where a branch of a
1537     subpattern has no definite first character. For example, (a*|b*)[cd] would
1538     previously give no result from pcre_study(). Now it recognizes that the
1539     first character must be a, b, c, or d.
1540    
1541     21. There was an incorrect error "recursive call could loop indefinitely" if
1542     a subpattern (or the entire pattern) that was being tested for matching an
1543     empty string contained only one non-empty item after a nested subpattern.
1544     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1545     incorrectly, because the \d was being skipped in the check.
1546    
1547     22. The pcretest program now has a new pattern option /B and a command line
1548     option -b, which is equivalent to adding /B to every pattern. This causes
1549     it to show the compiled bytecode, without the additional information that
1550     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1551     is the same as /B/I).
1552    
1553     23. A new optimization is now able automatically to treat some sequences such
1554     as a*b as a*+b. More specifically, if something simple (such as a character
1555     or a simple class like \d) has an unlimited quantifier, and is followed by
1556     something that cannot possibly match the quantified thing, the quantifier
1557     is automatically "possessified".
1558    
1559     24. A recursive reference to a subpattern whose number was greater than 39
1560     went wrong under certain circumstances in UTF-8 mode. This bug could also
1561     have affected the operation of pcre_study().
1562    
1563     25. Realized that a little bit of performance could be had by replacing
1564     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1565    
1566     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1567    
1568     27. Possessive quantifiers such as a++ were previously implemented by turning
1569     them into atomic groups such as ($>a+). Now they have their own opcodes,
1570     which improves performance. This includes the automatically created ones
1571     from 23 above.
1572    
1573     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1574     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1575     the first matched character to be a colon. This applied both to named and
1576     numbered groups.
1577    
1578     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1579    
1580     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1581     building PCRE on Windows easier, so I have included it in the distribution.
1582    
1583     31. There is now a check in pcretest against a ridiculously large number being
1584     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1585     loop, the loop is abandoned.
1586    
1587     32. Forward references to subpatterns in conditions such as (?(2)...) where
1588     subpattern 2 is defined later cause pcre_compile() to search forwards in
1589     the pattern for the relevant set of parentheses. This search went wrong
1590     when there were unescaped parentheses in a character class, parentheses
1591     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1592    
1593     33. "Subroutine" calls and backreferences were previously restricted to
1594     referencing subpatterns earlier in the regex. This restriction has now
1595     been removed.
1596    
1597     34. Added a number of extra features that are going to be in Perl 5.10. On the
1598     whole, these are just syntactic alternatives for features that PCRE had
1599     previously implemented using the Python syntax or my own invention. The
1600     other formats are all retained for compatibility.
1601    
1602     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1603     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1604     also .NET compatible.
1605    
1606     (b) A recursion or subroutine call to a named group can now be defined as
1607     (?&name) as well as (?P>name).
1608    
1609     (c) A backreference to a named group can now be defined as \k<name> or
1610     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1611     5.10, are also .NET compatible.
1612    
1613     (d) A conditional reference to a named group can now use the syntax
1614     (?(<name>) or (?('name') as well as (?(name).
1615    
1616     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1617     groups (named and numbered) that are never evaluated inline, but can be
1618     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1619     is always false. There may be only one alternative in such a group.
1620    
1621     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1622     as the simple (?(R). The condition is true only if the most recent
1623     recursion is that of the given number or name. It does not search out
1624     through the entire recursion stack.
1625    
1626     (g) The escape \gN or \g{N} has been added, where N is a positive or
1627     negative number, specifying an absolute or relative reference.
1628    
1629     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1630     some "unreachable code" warnings.
1631    
1632     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1633     things, this adds five new scripts.
1634    
1635     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1636     There were also incompatibilities regarding the handling of \Q..\E inside
1637     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1638     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1639    
1640     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1641     matches an empty string, and forcibly breaks the loop. There were bugs in
1642     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1643     against aaaa the result was just "a" rather than "aaaa", for example. Two
1644     separate and independent bugs (that affected different cases) have been
1645     fixed.
1646    
1647     39. Refactored the code to abolish the use of different opcodes for small
1648     capturing bracket numbers. This is a tidy that I avoided doing when I
1649     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1650     The new approach is not only tidier, it makes it possible to reduce the
1651     memory needed to fix the previous bug (38).
1652    
1653     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1654     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1655     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1656     mode.
1657    
1658     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1659     report.
1660    
1661     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1662     copy construction and assignment in the C++ wrapper.
1663    
1664     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1665     couple of bugs that could have given wrong results in the "--newline=crlf"
1666     case.
1667    
1668     44. Added a number of casts and did some reorganization of signed/unsigned int
1669     variables following suggestions from Dair Grant. Also renamed the variable
1670     "this" as "item" because it is a C++ keyword.
1671    
1672     45. Arranged for dftables to add
1673    
1674     #include "pcre_internal.h"
1675    
1676     to pcre_chartables.c because without it, gcc 4.x may remove the array
1677     definition from the final binary if PCRE is built into a static library and
1678     dead code stripping is activated.
1679    
1680     46. For an unanchored pattern, if a match attempt fails at the start of a
1681     newline sequence, and the newline setting is CRLF or ANY, and the next two
1682     characters are CRLF, advance by two characters instead of one.
1683    
1684    
1685 nigel 91 Version 6.7 04-Jul-06
1686     ---------------------
1687    
1688     1. In order to handle tests when input lines are enormously long, pcretest has
1689     been re-factored so that it automatically extends its buffers when
1690     necessary. The code is crude, but this _is_ just a test program. The
1691     default size has been increased from 32K to 50K.
1692    
1693     2. The code in pcre_study() was using the value of the re argument before
1694     testing it for NULL. (Of course, in any sensible call of the function, it
1695     won't be NULL.)
1696    
1697     3. The memmove() emulation function in pcre_internal.h, which is used on
1698     systems that lack both memmove() and bcopy() - that is, hardly ever -
1699     was missing a "static" storage class specifier.
1700    
1701     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1702     containing an extended class (one that cannot be represented by a bitmap
1703     because it contains high-valued characters or Unicode property items, e.g.
1704     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1705     pattern, but PCRE should not loop if you do not (it no longer does).
1706     [Detail: two cases were found: (a) a repeated subpattern containing an
1707     extended class; (b) a recursive reference to a subpattern that followed a
1708     previous extended class. It wasn't skipping over the extended class
1709     correctly when UTF-8 mode was not set.]
1710    
1711     5. A negated single-character class was not being recognized as fixed-length
1712     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1713     compile error "lookbehind assertion is not fixed length".
1714    
1715     6. The RunPerlTest auxiliary script was showing an unexpected difference
1716     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1717     write a Perl script that can interpret lines of an input file either as
1718     byte characters or as UTF-8, which is what "perltest" was being required to
1719     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1720     can't do is switch easily at run time between having the "use utf8;" pragma
1721     or not. In the end, I fudged it by using the RunPerlTest script to insert
1722     "use utf8;" explicitly for the UTF-8 tests.
1723    
1724     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1725     the end of the subject string, contrary to the documentation and to what
1726     Perl does. This was true of both matching functions. Now it matches only at
1727     the start of the subject and immediately after *internal* newlines.
1728    
1729     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1730     a pointer to an int instead of a pointer to an unsigned long int. This
1731     caused problems on 64-bit systems.
1732    
1733     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1734     instance of the 'standard' template library not being so standard".
1735    
1736     10. There was no check on the number of named subpatterns nor the maximum
1737     length of a subpattern name. The product of these values is used to compute
1738     the size of the memory block for a compiled pattern. By supplying a very
1739     long subpattern name and a large number of named subpatterns, the size
1740     computation could be caused to overflow. This is now prevented by limiting
1741     the length of names to 32 characters, and the number of named subpatterns
1742     to 10,000.
1743    
1744     11. Subpatterns that are repeated with specific counts have to be replicated in
1745     the compiled pattern. The size of memory for this was computed from the
1746     length of the subpattern and the repeat count. The latter is limited to
1747     65535, but there was no limit on the former, meaning that integer overflow
1748     could in principle occur. The compiled length of a repeated subpattern is
1749     now limited to 30,000 bytes in order to prevent this.
1750    
1751     12. Added the optional facility to have named substrings with the same name.
1752    
1753     13. Added the ability to use a named substring as a condition, using the
1754     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1755     are numbers (not recommended). Forward references are permitted.
1756    
1757     14. Added forward references in named backreferences (if you see what I mean).
1758    
1759     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1760     pattern could run off the end of the subject. For example, the pattern
1761     "(?s)(.{1,5})"8 did this with the subject "ab".
1762    
1763     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1764     PCRE_CASELESS was set when matching characters that were quantified with ?
1765     or *.
1766    
1767     17. A character class other than a single negated character that had a minimum
1768     but no maximum quantifier - for example [ab]{6,} - was not handled
1769     correctly by pce_dfa_exec(). It would match only one character.
1770    
1771     18. A valid (though odd) pattern that looked like a POSIX character
1772     class but used an invalid character after [ (for example [[,abc,]]) caused
1773     pcre_compile() to give the error "Failed: internal error: code overflow" or
1774     in some cases to crash with a glibc free() error. This could even happen if
1775     the pattern terminated after [[ but there just happened to be a sequence of
1776     letters, a binary zero, and a closing ] in the memory that followed.
1777    
1778     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1779     over the years. Originally (before any Unicode support), just the bottom 8
1780     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1781     output from "man perlunicode" includes this:
1782    
1783     The regular expression compiler produces polymorphic opcodes. That
1784     is, the pattern adapts to the data and automatically switches to
1785     the Unicode character scheme when presented with Unicode data--or
1786     instead uses a traditional byte scheme when presented with byte
1787     data.
1788    
1789     Sadly, a wide octal escape does not cause a switch, and in a string with
1790     no other multibyte characters, these octal escapes are treated as before.
1791     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1792     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1793     Unicode string.
1794    
1795     I have not perpetrated such confusion in PCRE. Up till now, it took just
1796     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1797     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1798     translate to the appropriate multibyte character.
1799    
1800     29. Applied some refactoring to reduce the number of warnings from Microsoft
1801     and Borland compilers. This has included removing the fudge introduced
1802     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1803     a warning about an unused variable.
1804    
1805     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1806     characters since release 4.0, because Perl (from release 5.004) does not.
1807     [Or at least, is documented not to: some releases seem to be in conflict
1808     with the documentation.] However, when a pattern was studied with
1809     pcre_study() and all its branches started with \s, PCRE still included VT
1810     as a possible starting character. Of course, this did no harm; it just
1811     caused an unnecessary match attempt.
1812    
1813     22. Removed a now-redundant internal flag bit that recorded the fact that case
1814     dependency changed within the pattern. This was once needed for "required
1815     byte" processing, but is no longer used. This recovers a now-scarce options
1816     bit. Also moved the least significant internal flag bit to the most-
1817     significant bit of the word, which was not previously used (hangover from
1818     the days when it was an int rather than a uint) to free up another bit for
1819     the future.
1820    
1821     23. Added support for CRLF line endings as well as CR and LF. As well as the
1822     default being selectable at build time, it can now be changed at runtime
1823     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1824     specify that it is scanning data with non-default line endings.
1825    
1826     24. Changed the definition of CXXLINK to make it agree with the definition of
1827     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1828    
1829     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1830     recursions. This makes a big different to stack usage for some patterns.
1831    
1832     26. If a subpattern containing a named recursion or subroutine reference such
1833     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1834     the space required for the compiled pattern went wrong and gave too small a
1835     value. Depending on the environment, this could lead to "Failed: internal
1836     error: code overflow at offset 49" or "glibc detected double free or
1837     corruption" errors.
1838    
1839     27. Applied patches from Google (a) to support the new newline modes and (b) to
1840     advance over multibyte UTF-8 characters in GlobalReplace.
1841    
1842     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1843     difference for some implementation of PCRE in some Windows version.
1844    
1845     29. Added some extra testing facilities to pcretest:
1846    
1847     \q<number> in a data line sets the "match limit" value
1848     \Q<number> in a data line sets the "match recursion limt" value
1849     -S <number> sets the stack size, where <number> is in megabytes
1850    
1851     The -S option isn't available for Windows.
1852    
1853    
1854 nigel 89 Version 6.6 06-Feb-06
1855     ---------------------
1856    
1857     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1858     in pcreposix.h. I have copied the definition from pcre.h.
1859    
1860     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1861     because pcre.h is no longer a built file.
1862    
1863     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1864     not normally included in the compiled code.
1865    
1866    
1867 nigel 87 Version 6.5 01-Feb-06
1868     ---------------------
1869    
1870     1. When using the partial match feature with pcre_dfa_exec(), it was not
1871     anchoring the second and subsequent partial matches at the new starting
1872     point. This could lead to incorrect results. For example, with the pattern
1873     /1234/, partially matching against "123" and then "a4" gave a match.
1874    
1875     2. Changes to pcregrep:
1876    
1877     (a) All non-match returns from pcre_exec() were being treated as failures
1878     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1879     error message is output. Some extra information is given for the
1880     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1881     probably the only errors that are likely to be caused by users (by
1882     specifying a regex that has nested indefinite repeats, for instance).
1883     If there are more than 20 of these errors, pcregrep is abandoned.
1884    
1885     (b) A binary zero was treated as data while matching, but terminated the
1886     output line if it was written out. This has been fixed: binary zeroes
1887     are now no different to any other data bytes.
1888    
1889     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1890     used to set a locale for matching. The --locale=xxxx long option has
1891     been added (no short equivalent) to specify a locale explicitly on the
1892     pcregrep command, overriding the environment variables.
1893    
1894     (d) When -B was used with -n, some line numbers in the output were one less
1895     than they should have been.
1896    
1897     (e) Added the -o (--only-matching) option.
1898    
1899     (f) If -A or -C was used with -c (count only), some lines of context were
1900     accidentally printed for the final match.
1901    
1902     (g) Added the -H (--with-filename) option.
1903    
1904     (h) The combination of options -rh failed to suppress file names for files
1905     that were found from directory arguments.
1906    
1907     (i) Added the -D (--devices) and -d (--directories) options.
1908    
1909     (j) Added the -F (--fixed-strings) option.
1910    
1911     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1912    
1913     (l) Added the --colo(u)r option.
1914    
1915     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1916     is not present by default.
1917    
1918     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1919     items such as (?R) or (?1), when the recursion could match a number of
1920     alternatives. If it matched one of the alternatives, but subsequently,
1921     outside the recursion, there was a failure, the code tried to back up into
1922     the recursion. However, because of the way PCRE is implemented, this is not
1923     possible, and the result was an incorrect result from the match.
1924    
1925     In order to prevent this happening, the specification of recursion has
1926     been changed so that all such subpatterns are automatically treated as
1927     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1928    
1929     4. I had overlooked the fact that, in some locales, there are characters for
1930     which isalpha() is true but neither isupper() nor islower() are true. In
1931     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1932     and ordfeminine) are like this. This affected the treatment of \w and \W
1933     when they appeared in character classes, but not when they appeared outside
1934     a character class. The bit map for "word" characters is now created
1935     separately from the results of isalnum() instead of just taking it from the
1936     upper, lower, and digit maps. (Plus the underscore character, of course.)
1937    
1938     5. The above bug also affected the handling of POSIX character classes such as
1939     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1940     permanent tables. Instead, the bit maps for such a class were previously
1941     created as the appropriate unions of the upper, lower, and digit bitmaps.
1942     Now they are created by subtraction from the [[:word:]] class, which has
1943     its own bitmap.
1944    
1945     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1946     It is created by subtracting the vertical space characters (\x09, \x0a,
1947     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1948     subtraction was done in the overall bitmap for a character class, meaning
1949     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1950     be recognized. This bug has been fixed.
1951    
1952     7. Patches from the folks at Google:
1953    
1954     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1955     real life, but is still worth protecting against".
1956    
1957     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1958     regular expressions".
1959    
1960     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1961     have it.
1962    
1963     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1964     "configure" and the latter not, in order to fix a problem somebody had
1965     with compiling the Arg class on HP-UX.
1966    
1967     (e) Improve the error-handling of the C++ wrapper a little bit.
1968    
1969     (f) New tests for checking recursion limiting.
1970    
1971     8. The pcre_memmove() function, which is used only if the environment does not
1972     have a standard memmove() function (and is therefore rarely compiled),
1973     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1974     returning a result (though PCRE never actually uses the result).
1975    
1976     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1977     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1978     returned instead of calling malloc() with an overflowing number that would
1979     most likely cause subsequent chaos.
1980    
1981     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1982    
1983     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1984     with this option is matched, the nmatch and pmatch options of regexec() are
1985     ignored.
1986    
1987     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1988     provided in case anyone wants to the the POSIX interface with UTF-8
1989     strings.
1990    
1991     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1992     C++ linking (needed for some HP-UX environments).
1993    
1994     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1995     (unused parameter) and in the pcre_printint() function (omitted "default"
1996     switch label when the default is to do nothing).
1997    
1998     15. Added some code to make it possible, when PCRE is compiled as a C++
1999     library, to replace subject pointers for pcre_exec() with a smart pointer
2000     class, thus making it possible to process discontinuous strings.
2001    
2002     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2003     much the same function. They were added by different people who were trying
2004     to make PCRE easy to compile on non-Unix systems. It has been suggested
2005     that PCRE_EXPORT be abolished now that there is more automatic apparatus
2006     for compiling on Windows systems. I have therefore replaced it with
2007     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2008     defaults to "extern" for C or "extern C" for C++, which works fine on
2009     Unix-like systems. It is now possible to override the value of PCRE_DATA_
2010     SCOPE with something explicit in config.h. In addition:
2011    
2012     (a) pcreposix.h still had just "extern" instead of either of these macros;
2013     I have replaced it with PCRE_DATA_SCOPE.
2014    
2015     (b) Functions such as _pcre_xclass(), which are internal to the library,
2016     but external in the C sense, all had PCRE_EXPORT in their definitions.
2017     This is apparently wrong for the Windows case, so I have removed it.
2018     (It makes no difference on Unix-like systems.)
2019    
2020     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2021     of recursive calls to match(). This is different to MATCH_LIMIT because
2022     that limits the total number of calls to match(), not all of which increase
2023     the depth of recursion. Limiting the recursion depth limits the amount of
2024     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2025     when PCRE is compiled, and changed at run time. A patch from Google adds
2026     this functionality to the C++ interface.
2027    
2028     18. Changes to the handling of Unicode character properties:
2029    
2030     (a) Updated the table to Unicode 4.1.0.
2031    
2032     (b) Recognize characters that are not in the table as "Cn" (undefined).
2033    
2034     (c) I revised the way the table is implemented to a much improved format
2035     which includes recognition of ranges. It now supports the ranges that
2036     are defined in UnicodeData.txt, and it also amalgamates other
2037     characters into ranges. This has reduced the number of entries in the
2038     table from around 16,000 to around 3,000, thus reducing its size
2039     considerably. I realized I did not need to use a tree structure after
2040     all - a binary chop search is just as efficient. Having reduced the
2041     number of entries, I extended their size from 6 bytes to 8 bytes to
2042     allow for more data.
2043    
2044     (d) Added support for Unicode script names via properties such as \p{Han}.
2045    
2046     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2047     matching that character.
2048    
2049     20. When matching a repeated Unicode property with a minimum greater than zero,
2050     (for example \pL{2,}), PCRE could look past the end of the subject if it
2051     reached it while seeking the minimum number of characters. This could
2052     happen only if some of the characters were more than one byte long, because
2053     there is a check for at least the minimum number of bytes.
2054    
2055     21. Refactored the implementation of \p and \P so as to be more general, to
2056     allow for more different types of property in future. This has changed the
2057     compiled form incompatibly. Anybody with saved compiled patterns that use
2058     \p or \P will have to recompile them.
2059    
2060     22. Added "Any" and "L&" to the supported property types.
2061    
2062     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2063     but give a compile time error if the value is greater than 0xff.
2064    
2065     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2066     accidentally not being installed or uninstalled.
2067    
2068     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2069     made were to insert the current release number. This seemed silly, because
2070     it made things harder for people building PCRE on systems that don't run
2071     "configure". I have turned pcre.h into a distributed file, no longer built
2072     by "configure", with the version identification directly included. There is
2073     no longer a pcre.h.in file.
2074    
2075     However, this change necessitated a change to the pcre-config script as
2076     well. It is built from pcre-config.in, and one of the substitutions was the
2077     release number. I have updated configure.ac so that ./configure now finds
2078     the release number by grepping pcre.h.
2079    
2080     26. Added the ability to run the tests under valgrind.
2081    
2082    
2083 nigel 85 Version 6.4 05-Sep-05
2084     ---------------------
2085    
2086     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2087     "--" to be printed when multiple files were scanned, even when none of the
2088     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2089     consider it to be a bug, and have restored the previous behaviour.
2090    
2091     2. A couple of code tidies to get rid of compiler warnings.
2092    
2093     3. The pcretest program used to cheat by referring to symbols in the library
2094     whose names begin with _pcre_. These are internal symbols that are not
2095     really supposed to be visible externally, and in some environments it is
2096     possible to suppress them. The cheating is now confined to including
2097     certain files from the library's source, which is a bit cleaner.
2098    
2099     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2100     file's purpose clearer.
2101    
2102     5. Reorganized pcre_ucp_findchar().
2103    
2104    
2105 nigel 83 Version 6.3 15-Aug-05
2106     ---------------------
2107    
2108     1. The file libpcre.pc.in did not have general read permission in the tarball.
2109    
2110     2. There were some problems when building without C++ support:
2111    
2112     (a) If C++ support was not built, "make install" and "make test" still
2113     tried to test it.
2114    
2115     (b) There were problems when the value of CXX was explicitly set. Some
2116     changes have been made to try to fix these, and ...
2117    
2118     (c) --disable-cpp can now be used to explicitly disable C++ support.
2119    
2120     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2121     backslash in a target when C++ was disabled. This confuses some
2122     versions of "make", apparently. Using an intermediate variable solves
2123     this. (Same for CPP_LOBJ.)
2124    
2125     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2126     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2127     necessary on certain architectures.
2128    
2129     4. Added a setting of -export-symbols-regex to the link command to remove
2130     those symbols that are exported in the C sense, but actually are local
2131     within the library, and not documented. Their names all begin with
2132     "_pcre_". This is not a perfect job, because (a) we have to except some
2133     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2134     available (and never for static libraries). I have made a note to try to
2135     find a way round (a) in the future.
2136    
2137    
2138 nigel 81 Version 6.2 01-Aug-05
2139     ---------------------
2140    
2141     1. There was no test for integer overflow of quantifier values. A construction
2142     such as {1111111111111111} would give undefined results. What is worse, if
2143     a minimum quantifier for a parenthesized subpattern overflowed and became
2144     negative, the calculation of the memory size went wrong. This could have
2145     led to memory overwriting.
2146    
2147     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2148    
2149     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2150     operating environments where this matters.
2151    
2152     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2153     PCRE options from within the C++ wrapper.
2154    
2155     5. Named capturing subpatterns were not being correctly counted when a pattern
2156     was compiled. This caused two problems: (a) If there were more than 100
2157     such subpatterns, the calculation of the memory needed for the whole
2158     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2159     back references of the form \12, where the number was greater than 9, were
2160     not recognized as back references, even though there were sufficient
2161     previous subpatterns.
2162    
2163     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2164     versions of gcc, e.g. 2.95.4.
2165    
2166    
2167 nigel 79 Version 6.1 21-Jun-05
2168     ---------------------
2169    
2170     1. There was one reference to the variable "posix" in pcretest.c that was not
2171     surrounded by "#if !defined NOPOSIX".
2172    
2173     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2174     the cross-check on the old pcre_info() function, for the benefit of the
2175     cut-down version of PCRE that is currently imported into Exim.
2176    
2177     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2178     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2179     patterns that start (?i) but I don't think that matters. The use of (?i) is
2180     just an example; this all applies to the other options as well.
2181    
2182     4. Since libtool seems to echo the compile commands it is issuing, the output
2183     from "make" can be reduced a bit by putting "@" in front of each libtool
2184     compile command.
2185    
2186     5. Patch from the folks at Google for configure.in to be a bit more thorough
2187     in checking for a suitable C++ installation before trying to compile the
2188     C++ stuff. This should fix a reported problem when a compiler was present,
2189     but no suitable headers.
2190    
2191     6. The man pages all had just "PCRE" as their title. I have changed them to
2192     be the relevant file name. I have also arranged that these names are
2193     retained in the file doc/pcre.txt, which is a concatenation in text format
2194     of all the man pages except the little individual ones for each function.
2195    
2196     7. The NON-UNIX-USE file had not been updated for the different set of source
2197     files that come with release 6. I also added a few comments about the C++
2198     wrapper.
2199    
2200    
2201 nigel 77 Version 6.0 07-Jun-05
2202     ---------------------
2203    
2204     1. Some minor internal re-organization to help with my DFA experiments.
2205    
2206     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2207     didn't matter for the library itself when fully configured, but did matter
2208     when compiling without UCP support, or within Exim, where the ucp files are
2209     not imported.
2210    
2211     3. Refactoring of the library code to split up the various functions into
2212     different source modules. The addition of the new DFA matching code (see
2213     below) to a single monolithic source would have made it really too
2214     unwieldy, quite apart from causing all the code to be include in a
2215     statically linked application, when only some functions are used. This is
2216     relevant even without the DFA addition now that patterns can be compiled in
2217     one application and matched in another.
2218    
2219     The downside of splitting up is that there have to be some external
2220     functions and data tables that are used internally in different modules of
2221     the library but which are not part of the API. These have all had their
2222     names changed to start with "_pcre_" so that they are unlikely to clash
2223     with other external names.
2224    
2225     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2226     a different (DFA) algorithm. Although it is slower than the original
2227     function, it does have some advantages for certain types of matching
2228     problem.
2229    
2230     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2231     including restarting after a partial match.
2232    
2233     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2234     defined when compiling for Windows was sent to me. I have put it into the
2235     code, though I have no means of testing or verifying it.
2236    
2237     7. Added the pcre_refcount() auxiliary function.
2238    
2239     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2240     match before or at the first newline in the subject string. In pcretest,
2241     the /f option on a pattern can be used to set this.
2242    
2243     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2244     would behave wrongly. This has been present in PCRE since release 4.0.
2245    
2246     10. A number of changes to the pcregrep command:
2247    
2248     (a) Refactored how -x works; insert ^(...)$ instead of setting
2249     PCRE_ANCHORED and checking the length, in preparation for adding
2250     something similar for -w.
2251    
2252     (b) Added the -w (match as a word) option.
2253    
2254     (c) Refactored the way lines are read and buffered so as to have more
2255     than one at a time available.
2256    
2257     (d) Implemented a pcregrep test script.
2258    
2259     (e) Added the -M (multiline match) option. This allows patterns to match
2260     over several lines of the subject. The buffering ensures that at least
2261     8K, or the rest of the document (whichever is the shorter) is available
2262     for matching (and similarly the previous 8K for lookbehind assertions).
2263    
2264     (f) Changed the --help output so that it now says
2265    
2266     -w, --word-regex(p)
2267    
2268     instead of two lines, one with "regex" and the other with "regexp"
2269     because that confused at least one person since the short forms are the
2270     same. (This required a bit of code, as the output is generated
2271     automatically from a table. It wasn't just a text change.)
2272    
2273     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2274     option but starts with a hyphen. Could be a pattern or a path name
2275     starting with a hyphen, for instance.
2276    
2277     (h) "-" can be given as a file name to represent stdin.
2278    
2279     (i) When file names are being printed, "(standard input)" is used for
2280     the standard input, for compatibility with GNU grep. Previously
2281     "<stdin>" was used.
2282    
2283     (j) The option --label=xxx can be used to supply a name to be used for
2284     stdin when file names are being printed. There is no short form.
2285    
2286     (k) Re-factored the options decoding logic because we are going to add
2287     two more options that take data. Such options can now be given in four
2288     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2289    
2290     (l) Added the -A, -B, and -C options for requesting that lines of context
2291     around matches be printed.
2292    
2293     (m) Added the -L option to print the names of files that do not contain
2294     any matching lines, that is, the complement of -l.
2295    
2296     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2297     continue to scan other files.
2298    
2299     (o) The -s option was incorrectly implemented. For compatibility with other
2300     greps, it now suppresses the error message for a non-existent or non-
2301     accessible file (but not the return code). There is a new option called
2302     -q that suppresses the output of matching lines, which was what -s was
2303     previously doing.
2304    
2305     (p) Added --include and --exclude options to specify files for inclusion
2306     and exclusion when recursing.
2307    
2308     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2309     Hopefully, it now does.
2310    
2311     12. Missing cast in pcre_study().
2312    
2313     13. Added an "uninstall" target to the makefile.
2314    
2315     14. Replaced "extern" in the function prototypes in Makefile.in with
2316     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2317     world, but is set differently for Windows.
2318    
2319     15. Added a second compiling function called pcre_compile2(). The only
2320     difference is that it has an extra argument, which is a pointer to an
2321     integer error code. When there is a compile-time failure, this is set
2322     non-zero, in addition to the error test pointer being set to point to an
2323     error message. The new argument may be NULL if no error number is required
2324     (but then you may as well call pcre_compile(), which is now just a
2325     wrapper). This facility is provided because some applications need a
2326     numeric error indication, but it has also enabled me to tidy up the way
2327     compile-time errors are handled in the POSIX wrapper.
2328    
2329     16. Added VPATH=.libs to the makefile; this should help when building with one
2330     prefix path and installing with another. (Or so I'm told by someone who
2331     knows more about this stuff than I do.)
2332    
2333     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2334     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2335     match everything, including newlines. This is not POSIX-compatible, but
2336     somebody wanted the feature. From pcretest it can be activated by using
2337     both the P and the s flags.
2338    
2339     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2340    
2341     19. libpcre.pc was being incorrectly installed as executable.
2342    
2343     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2344     it now also looks for '\r' so that it will work unmodified on Windows.
2345    
2346     21. Added Google's contributed C++ wrapper to the distribution.
2347    
2348     22. Added some untidy missing memory free() calls in pcretest, to keep
2349     Electric Fence happy when testing.
2350    
2351    
2352    
2353 nigel 75 Version 5.0 13-Sep-04
2354     ---------------------
2355    
2356     1. Internal change: literal characters are no longer packed up into items
2357     containing multiple characters in a single byte-string. Each character
2358     is now matched using a separate opcode. However, there may be more than one
2359     byte in the character in UTF-8 mode.
2360    
2361     2. The pcre_callout_block structure has two new fields: pattern_position and
2362     next_item_length. These contain the offset in the pattern to the next match
2363     item, and its length, respectively.
2364    
2365     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2366     insertion of callouts before each pattern item. Added the /C option to
2367     pcretest to make use of this.
2368    
2369     4. On the advice of a Windows user, the lines
2370    
2371     #if defined(_WIN32) || defined(WIN32)
2372     _setmode( _fileno( stdout ), 0x8000 );
2373     #endif /* defined(_WIN32) || defined(WIN32) */
2374    
2375     have been added to the source of pcretest. This apparently does useful
2376     magic in relation to line terminators.
2377    
2378     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2379     for the benefit of those environments where the "b" makes a difference.
2380    
2381     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2382     to know about it. I have put a hack into configure.in that adds in code
2383     to set GCC=yes if CC=icc. This seems to end up at a point in the
2384     generated configure script that is early enough to affect the setting of
2385     compiler options, which is what is needed, but I have no means of testing
2386     whether it really works. (The user who reported this had patched the
2387     generated configure script, which of course I cannot do.)
2388    
2389     LATER: After change 22 below (new libtool files), the configure script
2390     seems to know about icc (and also ecc). Therefore, I have commented out
2391     this hack in configure.in.
2392    
2393     7. Added support for pkg-config (2 patches were sent in).
2394    
2395     8. Negated POSIX character classes that used a combination of internal tables
2396     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2397     [[:^ascii]]. Typically, they would match almost any characters. The other
2398     POSIX classes were not broken in this way.
2399    
2400     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2401     to find the match, as PCRE was deluded into thinking that the match had to
2402     start at the start point or following a newline. The same bug applied to
2403     patterns with negative forward assertions or any backward assertions
2404     preceding ".*" at the start, unless the pattern required a fixed first
2405     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2406    
2407     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2408     starting at the last subject character, bytes beyond the end of the subject
2409     string were read.
2410    
2411     11. Renamed the variable "class" as "classbits" to make life easier for C++
2412     users. (Previously there was a macro definition, but it apparently wasn't
2413     enough.)
2414    
2415     12. Added the new field "tables" to the extra data so that tables can be passed
2416     in at exec time, or the internal tables can be re-selected. This allows
2417     a compiled regex to be saved and re-used at a later time by a different
2418     program that might have everything at different addresses.
2419    
2420     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2421     -R library as well as a -L library.
2422    
2423     14. The debugging options of pcretest (-d on the command line or D on a
2424     pattern) showed incorrect output for anything following an extended class
2425     that contained multibyte characters and which was followed by a quantifier.
2426    
2427     15. Added optional support for general category Unicode character properties
2428     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2429     support. It adds about 90K to the size of the library. The meanings of the
2430     inbuilt class escapes such as \d and \s have NOT been changed.
2431    
2432     16. Updated pcredemo.c to include calls to free() to release the memory for the
2433     compiled pattern.
2434    
2435     17. The generated file chartables.c was being created in the source directory
2436     instead of in the building directory. This caused the build to fail if the
2437     source directory was different from the building directory, and was
2438     read-only.
2439    
2440     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2441     file. No doubt somebody will tell me if they don't make sense... Also added
2442     Dan Mooney's comments about building on OpenVMS.
2443    
2444     19. Added support for partial matching via the PCRE_PARTIAL option for
2445     pcre_exec() and the \P data escape in pcretest.
2446    
2447     20. Extended pcretest with 3 new pattern features:
2448    
2449     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2450     write the compiled pattern to the file whose name is "rest-of-line".
2451     This is a straight binary dump of the data, with the saved pointer to
2452     the character tables forced to be NULL. The study data, if any, is
2453     written too. After writing, pcretest reads a new pattern.
2454    
2455     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2456     compiled pattern from the given file. There must not be any
2457     occurrences of "<" in the file name (pretty unlikely); if there are,
2458     pcretest will instead treat the initial "<" as a pattern delimiter.
2459     After reading in the pattern, pcretest goes on to read data lines as
2460     usual.
2461    
2462     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2463     and 16-bit fields in a compiled pattern, to simulate a pattern that
2464     was compiled on a host of opposite endianness.
2465    
2466     21. The pcre-exec() function can now cope with patterns that were compiled on
2467     hosts of opposite endianness, with this restriction:
2468    
2469     As for any compiled expression that is saved and used later, the tables
2470     pointer field cannot be preserved; the extra_data field in the arguments
2471     to pcre_exec() should be used to pass in a tables address if a value
2472     other than the default internal tables were used at compile time.
2473    
2474     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2475     now diagnosed as an error. Previously, most of the time, a negative number
2476     would have been treated as zero, but if in addition "ovector" was passed as
2477     NULL, a crash could occur.
2478    
2479     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2480     new versions from the libtool 1.5 distribution (the last one is a copy of
2481     a file called libtool.m4). This seems to have fixed the need to patch
2482     "configure" to support Darwin 1.3 (which I used to do). However, I still
2483     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2484     workstation).
2485    
2486     24. Changed the PCRE licence to be the more standard "BSD" licence.
2487    
2488    
2489 nigel 73 Version 4.5 01-Dec-03
2490     ---------------------
2491    
2492     1. There has been some re-arrangement of the code for the match() function so
2493     that it can be compiled in a version that does not call itself recursively.
2494     Instead, it keeps those local variables that need separate instances for
2495     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2496     needs to "recurse". Keeping track of where control must go is done by means
2497     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2498     hide most of the details from the main code, and operates only if
2499     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2500     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2501     operating.
2502    
2503     To make it easier for callers to provide specially tailored get/free
2504     functions for this usage, two new functions, pcre_stack_malloc, and
2505     pcre_stack_free, are used. They are always called in strict stacking order,
2506     and the size of block requested is always the same.
2507    
2508     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2509     PCRE has been compiled to use the stack or the heap for recursion. The
2510     -C option of pcretest uses this to show which version is compiled.
2511    
2512     A new data escape \S, is added to pcretest; it causes the amounts of store
2513     obtained and freed by both kinds of malloc/free at match time to be added
2514     to the output.
2515    
2516     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2517     what's available on my current Linux desktop machine.
2518    
2519     3. When matching a UTF-8 string, the test for a valid string at the start has
2520     been extended. If start_offset is not zero, PCRE now checks that it points
2521     to a byte that is the start of a UTF-8 character. If not, it returns
2522     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2523     this is necessary because there may be backward assertions in the pattern.
2524     When matching the same subject several times, it may save resources to use
2525     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2526    
2527     4. The code for checking the validity of UTF-8 strings has been tightened so
2528     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2529     containing "overlong sequences".
2530    
2531     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2532     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2533     should have been "&", but it just so happened that all the cases this let
2534     through by mistake were picked up later in the function.
2535    
2536     6. I had used a variable called "isblank" - this is a C99 function, causing
2537     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2538    
2539     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2540     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2541     so the version is shown; (c) stop "make test" echoing "./RunTest".
2542    
2543     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2544    
2545     9. The prototype for memmove() for systems that don't have it was using
2546     size_t, but the inclusion of the header that defines size_t was later. I've
2547     moved the #includes for the C headers earlier to avoid this.
2548    
2549     10. Added some adjustments to the code to make it easier to compiler on certain
2550     special systems:
2551    
2552     (a) Some "const" qualifiers were missing.
2553     (b) Added the macro EXPORT before all exported functions; by default this
2554     is defined to be empty.
2555     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2556     that it reads its output file name as an argument instead of writing
2557     to the standard output and assuming this can be redirected.
2558    
2559     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2560     class containing characters with values greater than 255, PCRE compilation
2561     went into a loop.
2562    
2563     12. A recursive reference to a subpattern that was within another subpattern
2564     that had a minimum quantifier of zero caused PCRE to crash. For example,
2565     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2566     recursion. If the recursively-called subpattern itself had a zero repeat,
2567     that was OK.
2568    
2569     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2570     buffer into which it was copied (for escape processing) was still set at
2571     1024, so long lines caused crashes.
2572    
2573     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2574     "internal error: code overflow...". This applied to any character class
2575     that was followed by a possessive quantifier.
2576    
2577     15. Modified the Makefile to add libpcre.la as a prerequisite for
2578     libpcreposix.la because I was told this is needed for a parallel build to
2579     work.
2580    
2581     16. If a pattern that contained .* following optional items at the start was
2582     studied, the wrong optimizing data was generated, leading to matching
2583     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2584     matching string must start with a or b or c. The correct conclusion for
2585     this pattern is that a match can start with any character.
2586    
2587    
2588 nigel 71 Version 4.4 13-Aug-03
2589     ---------------------
2590    
2591     1. In UTF-8 mode, a character class containing characters with values between
2592     127 and 255 was not handled correctly if the compiled pattern was studied.
2593     In fixing this, I have also improved the studying algorithm for such
2594     classes (slightly).
2595    
2596     2. Three internal functions had redundant arguments passed to them. Removal
2597     might give a very teeny performance improvement.
2598    
2599     3. Documentation bug: the value of the capture_top field in a callout is *one
2600     more than* the number of the hightest numbered captured substring.
2601    
2602     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2603     in incorrectly linking with a previously installed version. They now link
2604     explicitly with libpcre.la.
2605    
2606     5. configure.in no longer needs to recognize Cygwin specially.
2607    
2608     6. A problem in pcre.in for Windows platforms is fixed.
2609    
2610     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2611     pcretest, it used to include the size of the study block as part of its
2612     output. Unfortunately, the structure contains a field that has a different
2613     size on different hardware architectures. This meant that the tests that
2614     showed this size failed. As the block is currently always of a fixed size,
2615     this information isn't actually particularly useful in pcretest output, so
2616     I have just removed it.
2617    
2618     8. Three pre-processor statements accidentally did not start in column 1.
2619     Sadly, there are *still* compilers around that complain, even though
2620     standard C has not required this for well over a decade. Sigh.
2621    
2622     9. In pcretest, the code for checking callouts passed small integers in the
2623     callout_data field, which is a void * field. However, some picky compilers
2624     complained about the casts involved for this on 64-bit systems. Now
2625     pcretest passes the address of the small integer instead, which should get
2626     rid of the warnings.
2627    
2628     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2629     both compile and run time, and gives an error if an invalid UTF-8 sequence
2630     is found. There is a option for disabling this check in cases where the
2631     string is known to be correct and/or the maximum performance is wanted.
2632    
2633     11. In response to a bug report, I changed one line in Makefile.in from
2634    
2635     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2636     to
2637     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2638    
2639     to look similar to other lines, but I have no way of telling whether this
2640     is the right thing to do, as I do not use Windows. No doubt I'll get told
2641     if it's wrong...
2642    
2643    
2644 nigel 69 Version 4.3 21-May-03
2645     ---------------------
2646    
2647     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2648     Makefile.
2649    
2650     2. Some refactoring to improve the quality of the code:
2651    
2652     (i) The utf8_table... variables are now declared "const".
2653    
2654     (ii) The code for \cx, which used the "case flipping" table to upper case
2655     lower case letters, now just substracts 32. This is ASCII-specific,
2656     but the whole concept of \cx is ASCII-specific, so it seems
2657     reasonable.
2658    
2659     (iii) PCRE was using its character types table to recognize decimal and
2660     hexadecimal digits in the pattern. This is silly, because it handles
2661     only 0-9, a-f, and A-F, but the character types table is locale-
2662     specific, which means strange things might happen. A private
2663     table is now used for this - though it costs 256 bytes, a table is
2664     much faster than multiple explicit tests. Of course, the standard
2665     character types table is still used for matching digits in subject
2666     strings against \d.
2667    
2668     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2669     ending in _t are). So I've renamed it as ESC_tee.
2670    
2671     3. The first argument for regexec() in the POSIX wrapper should have been
2672     defined as "const".
2673    
2674     4. Changed pcretest to use malloc() for its buffers so that they can be
2675     Electric Fenced for debugging.
2676    
2677     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2678     to read one or more bytes before the start of the subject string. Often this
2679     had no effect on PCRE's behaviour, but in some circumstances it could
2680     provoke a segmentation fault.
2681    
2682     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2683     to try to read one or more bytes before the start of the subject string.
2684    
2685     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2686     UTF-8 support could misbehave in various ways if the subject string
2687     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2688     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2689     back over UTF-8 characters.)
2690    
2691    
2692 nigel 67 Version 4.2 14-Apr-03
2693     ---------------------
2694    
2695     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2696    
2697     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2698     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2699     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2700     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2701     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2702     and BUILD_EXEEXT
2703     Note: automatic setting of the BUILD variables is not yet working
2704     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2705     compile-time but not at link-time
2706     [LINK]: use for linking executables only
2707     make different versions for Windows and non-Windows
2708     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2709     libraries
2710     [LINK_FOR_BUILD]: new variable
2711     [OBJEXT]: use throughout
2712     [EXEEXT]: use throughout
2713     <winshared>: new target
2714     <wininstall>: new target
2715     <dftables.o>: use native compiler
2716     <dftables>: use native linker
2717     <install>: handle Windows platform correctly
2718     <clean>: ditto
2719     <check>: ditto
2720     copy DLL to top builddir before testing
2721    
2722     As part of these changes, -no-undefined was removed again. This was reported
2723     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2724     in any case.
2725    
2726     3. Some tidies to get rid of compiler warnings:
2727    
2728     . In the match_data structure, match_limit was an unsigned long int, whereas
2729     match_call_count was an int. I've made them both unsigned long ints.
2730    
2731     . In pcretest the fact that a const uschar * doesn't automatically cast to
2732     a void * provoked a warning.
2733    
2734     . Turning on some more compiler warnings threw up some "shadow" variables
2735     and a few more missing casts.
2736    
2737     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2738     option, a class that contained a single character with a value between 128
2739     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2740    
2741     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2742     option, a class that contained several characters, but with at least one
2743     whose value was between 128 and 255 caused PCRE to crash.
2744    
2745    
2746 nigel 65 Version 4.1 12-Mar-03
2747     ---------------------
2748 nigel 63
2749 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2750     needed, and a string in dftables.c that was longer than standard compilers are
2751     required to support.
2752    
2753     2. Compiling with Sun's compiler found a few more places where the code could
2754     be tidied up in order to avoid warnings.
2755    
2756     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2757     first of these names is deprecated in the latest Autoconf in favour of the name
2758     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2759     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2760     analogy I have changed it to CFLAGS_FOR_BUILD.
2761    
2762     4. Added -no-undefined to the linking command in the Makefile, because this is
2763     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2764     linking step for the pcreposix library.
2765    
2766     5. PCRE was failing to diagnose the case of two named groups with the same
2767     name.
2768    
2769     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2770     literal character that is needed in the subject for a match, and scans along to
2771     ensure that it is present before embarking on the full matching process. This
2772     saves time in cases of nested unlimited repeats that are never going to match.
2773     Problem: the scan can take a lot of time if the subject is very long (e.g.
2774     megabytes), thus penalizing straightforward matches. It is now done only if the
2775     amount of subject to be scanned is less than 1000 bytes.
2776    
2777     7. A lesser problem with the same optimization is that it was recording the
2778     first character of an anchored pattern as "needed", thus provoking a search
2779     right along the subject, even when the first match of the pattern was going to
2780     fail. The "needed" character is now not set for anchored patterns, unless it
2781     follows something in the pattern that is of non-fixed length. Thus, it still
2782     fulfils its original purpose of finding quick non-matches in cases of nested
2783     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2784    
2785    
2786     Version 4.0 17-Feb-03
2787     ---------------------
2788    
2789 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2790     extended to the end of string, PCRE compiled incorrect data. This could lead to
2791     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2792    
2793     2. Moved to autoconf 2.53 and libtool 1.4.2.
2794    
2795     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2796     the special perltest8 script is no longer needed - all the tests can be run
2797     from a single perltest script.
2798    
2799     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2800     by \s. It has now been removed in PCRE. This means it isn't recognized as
2801     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2802     class [:space:] *does* include VT, thereby creating a mess.
2803    
2804     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2805     space and tab.
2806    
2807     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2808     its new features into the main test script, reducing the number of scripts.
2809    
2810     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2811     were backward compatible, and made the (?i) apply to the whole pattern, as if
2812     /i were given. Now it behaves more logically, and applies the option setting
2813     only to what follows. PCRE has been changed to follow suit. However, if it
2814     finds options settings right at the start of the pattern, it extracts them into
2815     the global options, as before. Thus, they show up in the info data.
2816    
2817     8. Added support for the \Q...\E escape sequence. Characters in between are
2818     treated as literals. This is slightly different from Perl in that $ and @ are
2819     also handled as literals inside the quotes. In Perl, they will cause variable
2820     interpolation. Note the following examples:
2821    
2822     Pattern PCRE matches Perl matches
2823    
2824     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2825     \Qabc\$xyz\E abc\$xyz abc\$xyz
2826     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2827    
2828     For compatibility with Perl, \Q...\E sequences are recognized inside character
2829     classes as well as outside them.
2830    
2831     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2832     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2833     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2834     signed/unsigned warnings.
2835    
2836     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2837     option for pcretest, so I've replaced it by a simple function that does just
2838     that job.
2839    
2840     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2841     "pcregrep -".
2842    
2843     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2844     Java package. This provides some syntactic sugar for simple cases of what my
2845     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2846     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2847     item, you can use this simplified notation. Note that only makes sense with
2848     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2849     greediness, whatever the setting of the PCRE_UNGREEDY option.
2850    
2851     13. A change of greediness default within a pattern was not taking effect at
2852     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2853     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2854     was abstracted outside.
2855    
2856     14. PCRE now supports the \G assertion. It is true when the current matching
2857     position is at the start point of the match. This differs from \A when the
2858     starting offset is non-zero. Used with the /g option of pcretest (or similar
2859     code), it works in the same way as it does for Perl's /g option. If all
2860     alternatives of a regex begin with \G, the expression is anchored to the start
2861     match position, and the "anchored" flag is set in the compiled expression.
2862    
2863     15. Some bugs concerning the handling of certain option changes within patterns
2864     have been fixed. These applied to options other than (?ims). For example,
2865     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2866     been the other way round. Some of this was related to change 7 above.
2867    
2868     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2869     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2870     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2871     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2872    
2873     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2874     mode. Unlike ".", it always matches newline, whatever the setting of
2875     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2876     assertions. Perl allows it, but it doesn't (in general) work because it can't
2877     calculate the length of the lookbehind. At least, that's the case for Perl
2878     5.8.0 - I've been told they are going to document that it doesn't work in
2879     future.
2880    
2881     18. Added an error diagnosis for escapes that PCRE does not support: these are
2882     \L, \l, \N, \P, \p, \U, \u, and \X.
2883    
2884     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2885     reading past the end of the pattern in cases such as /[abcd/.
2886    
2887     20. PCRE was getting more memory than necessary for patterns with classes that
2888     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2889    
2890     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2891     compiling PCRE for use with Virtual Pascal.
2892    
2893     22. Small fix to the Makefile to make it work properly if the build is done
2894     outside the source tree.
2895    
2896     23. Added a new extension: a condition to go with recursion. If a conditional
2897     subpattern starts with (?(R) the "true" branch is used if recursion has
2898     happened, whereas the "false" branch is used only at the top level.
2899    
2900     24. When there was a very long string of literal characters (over 255 bytes
2901     without UTF support, over 250 bytes with UTF support), the computation of how
2902     much memory was required could be incorrect, leading to segfaults or other
2903     strange effects.
2904    
2905     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2906     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2907     there was a subsequent back reference to those brackets. This meant that, for
2908     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2909     possible to check for precisely this case. All we can do is abandon the
2910     optimization if .* occurs inside capturing brackets when there are any back
2911     references whatsoever. (See below for a better fix that came later.)
2912    
2913     26. The handling of the optimization for finding the first character of a
2914     non-anchored pattern, and for finding a character that is required later in the
2915     match were failing in some cases. This didn't break the matching; it just
2916     failed to optimize when it could. The way this is done has been re-implemented.
2917    
2918     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2919    
2920     28. Added a new feature that provides some of the functionality that Perl
2921     provides with (?{...}). The facility is termed a "callout". The way it is done
2922     in PCRE is for the caller to provide an optional function, by setting
2923     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2924     global variable. By default it is unset, which disables all calling out. To get
2925     the function called, the regex must include (?C) at appropriate points. This
2926     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2927     This provides a means of identifying different callout points. When PCRE
2928     reaches such a point in the regex, if pcre_callout has been set, the external
2929     function is called. It is provided with data in a structure called
2930     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2931     matching continues; if it returns a non-zero value, the match at the current
2932     point fails. However, backtracking will occur if possible. [This was changed
2933     later and other features added - see item 49 below.]
2934    
2935     29. pcretest is upgraded to test the callout functionality. It provides a
2936     callout function that displays information. By default, it shows the start of
2937     the match and the current position in the text. There are some new data escapes
2938     to vary what happens:
2939    
2940     \C+ in addition, show current contents of captured substrings
2941     \C- do not supply a callout function
2942     \C!n return 1 when callout number n is reached
2943     \C!n!m return 1 when callout number n is reached for the mth time
2944    
2945     30. If pcregrep was called with the -l option and just a single file name, it
2946     output "<stdin>" if a match was found, instead of the file name.
2947    
2948     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2949     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2950     pcre_exec(). This saves a malloc/free per call. The default value of
2951     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2952     when configuring.
2953    
2954     32. The default maximum size of a compiled pattern is 64K. There have been a
2955     few cases of people hitting this limit. The code now uses macros to handle the
2956     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2957     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2958     configuring. Tests 2 and 5 work only with 2-byte links because they output
2959     debugging information about compiled patterns.
2960    
2961     33. Internal code re-arrangements:
2962    
2963     (a) Moved the debugging function for printing out a compiled regex into
2964     its own source file (printint.c) and used #include to pull it into
2965     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2966     separate copies.
2967    
2968     (b) Defined the list of op-code names for debugging as a macro in
2969     internal.h so that it is next to the definition of the opcodes.
2970    
2971     (c) Defined a table of op-code lengths for simpler skipping along compiled
2972     code. This is again a macro in internal.h so that it is next to the
2973     definition of the opcodes.
2974    
2975     34. Added support for recursive calls to individual subpatterns, along the
2976     lines of Robin Houston's patch (but implemented somewhat differently).
2977    
2978     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2979     allow it to read and process whole directories in Win32. This code was
2980     contributed by Lionel Fourquaux; it has not been tested by me.
2981    
2982     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2983     used to name a group. Names consist of alphanumerics and underscores, and must
2984     be unique. Back references use the syntax (?P=name) and recursive calls use
2985     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2986     numbers. The function pcre_fullinfo() can be used after compilation to extract
2987     a name/number map. There are three relevant calls:
2988    
2989     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2990     PCRE_INFO_NAMECOUNT yields the number of entries
2991     PCRE_INFO_NAMETABLE yields a pointer to the map.
2992    
2993     The map is a vector of fixed-size entries. The size of each entry depends on
2994     the length of the longest name used. The first two bytes of each entry are the
2995     group number, most significant byte first. There follows the corresponding
2996     name, zero terminated. The names are in alphabetical order.
2997    
2998     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2999     case instead of 255. Making it the same both with and without UTF-8 support
3000     means that the same test output works with both.
3001    
3002     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3003     calling malloc() with a zero argument.
3004    
3005     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3006     optimization. I've improved things by keeping a bitmap of backreferences with
3007     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3008     fact referenced, the optimization can be applied. It is unlikely that a
3009     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3010     the match to follow \n) will appear inside brackets with a number greater than
3011     31, but if it does, any back reference > 31 suppresses the optimization.
3012    
3013     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3014     of disabling numbered capturing parentheses. Any opening parenthesis that is
3015     not followed by ? behaves as if it were followed by ?: but named parentheses
3016     can still be used for capturing (and they will acquire numbers in the usual
3017     way).
3018    
3019     41. Redesigned the return codes from the match() function into yes/no/error so
3020     that errors can be passed back from deep inside the nested calls. A malloc
3021     failure while inside a recursive subpattern call now causes the
3022     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3023    
3024     42. It is now possible to set a limit on the number of times the match()
3025     function is called in a call to pcre_exec(). This facility makes it possible to
3026     limit the amount of recursion and backtracking, though not in a directly
3027     obvious way, because the match() function is used in a number of different
3028     circumstances. The count starts from zero for each position in the subject
3029     string (for non-anchored patterns). The default limit is, for compatibility, a
3030     large number, namely 10 000 000. You can change this in two ways:
3031    
3032     (a) When configuring PCRE before making, you can use --with-match-limit=n
3033     to set a default value for the compiled library.
3034    
3035     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3036     a different value is set. See 45 below.
3037    
3038     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3039    
3040     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3041     of things that can be changed at compile time. The first argument specifies
3042     what is wanted and the second points to where the information is to be placed.
3043     The current list of available information is:
3044    
3045     PCRE_CONFIG_UTF8
3046    
3047     The output is an integer that is set to one if UTF-8 support is available;
3048     otherwise it is set to zero.
3049    
3050     PCRE_CONFIG_NEWLINE
3051    
3052     The output is an integer that it set to the value of the code that is used for
3053     newline. It is either LF (10) or CR (13).
3054    
3055     PCRE_CONFIG_LINK_SIZE
3056    
3057     The output is an integer that contains the number of bytes used for internal
3058     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3059    
3060     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3061    
3062     The output is an integer that contains the threshold above which the POSIX
3063     interface uses malloc() for output vectors. See item 31 above.
3064    
3065     PCRE_CONFIG_MATCH_LIMIT
3066    
3067     The output is an unsigned integer that contains the default limit of the number
3068     of match() calls in a pcre_exec() execution. See 42 above.
3069    
3070     44. pcretest has been upgraded by the addition of the -C option. This causes it
3071     to extract all the available output from the new pcre_config() function, and to
3072     output it. The program then exits immediately.
3073    
3074     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3075     order to support additional features. One way would have been to define
3076     pcre_exec2() (for example) with extra arguments, but this would not have been
3077     extensible, and would also have required all calls to the original function to
3078     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3079     is used for passing in "extra" data from pcre_study().
3080    
3081     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3082     contains the following fields:
3083    
3084     flags a bitmap indicating which of the following fields are set
3085     study_data opaque data from pcre_study()
3086     match_limit a way of specifying a limit on match() calls for a specific
3087     call to pcre_exec()
3088     callout_data data for callouts (see 49 below)
3089    
3090     The flag bits are also defined in pcre.h, and are
3091    
3092     PCRE_EXTRA_STUDY_DATA
3093     PCRE_EXTRA_MATCH_LIMIT
3094     PCRE_EXTRA_CALLOUT_DATA
3095    
3096     The pcre_study() function now returns one of these new pcre_extra blocks, with
3097     the actual study data pointed to by the study_data field, and the
3098     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3099     before. That is, this change is entirely upwards-compatible and requires no
3100     change to existing code.
3101    
3102     If you want to pass in additional data to pcre_exec(), you can either place it
3103     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3104     block.
3105    
3106     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3107     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3108     times with different match limits, until it finds the minimum value needed for
3109     pcre_exec() to complete. The value is then output. This can be instructive; for
3110     most simple matches the number is quite small, but for pathological cases it
3111     gets very large very quickly.
3112    
3113     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3114     returns the size of the data block pointed to by the study_data field in a
3115     pcre_extra block, that is, the value that was passed as the argument to
3116     pcre_malloc() when PCRE was getting memory in which to place the information
3117     created by pcre_study(). The fourth argument should point to a size_t variable.
3118     pcretest has been extended so that this information is shown after a successful
3119     pcre_study() call when information about the compiled regex is being displayed.
3120    
3121     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3122     because what follows is always an absolute path. (Later: it turns out that this
3123     is more than cosmetic for MinGW, because it doesn't like empty path
3124     components.)
3125    
3126     49. Some changes have been made to the callout feature (see 28 above):
3127    
3128     (i) A callout function now has three choices for what it returns:
3129    
3130     0 => success, carry on matching
3131     > 0 => failure at this point, but backtrack if possible
3132     < 0 => serious error, return this value from pcre_exec()
3133    
3134     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3135     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3136     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3137     use by callout functions. It will never be used by PCRE itself.
3138    
3139     (ii) The pcre_extra structure (see 45 above) has a void * field called
3140     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3141     pcre_callout_block structure has a field of the same name. The contents of
3142     the field passed in the pcre_extra structure are passed to the callout
3143     function in the corresponding field in the callout block. This makes it
3144     easier to use the same callout-containing regex from multiple threads. For
3145     testing, the pcretest program has a new data escape
3146    
3147     \C*n pass the number n (may be negative) as callout_data
3148    
3149     If the callout function in pcretest receives a non-zero value as
3150     callout_data, it returns that value.
3151    
3152     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3153     there were some redundant $(CFLAGS) in commands that are now specified as
3154     $(LINK), which already includes $(CFLAGS).
3155    
3156     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3157     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3158     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3159     one-byte characters throughout. Note that case-insensitive matching applies
3160     only to characters whose values are less than 256. PCRE doesn't support the
3161     notion of cases for higher-valued characters.
3162    
3163     (i) A character class whose characters are all within 0-255 is handled as
3164     a bit map, and the map is inverted for negative classes. Previously, a
3165     character > 255 always failed to match such a class; however it should
3166     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3167    
3168     (ii) A negated character class with a single character < 255 is coded as
3169     "not this character" (OP_NOT). This wasn't working properly when the test
3170     character was multibyte, either singly or repeated.
3171    
3172     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3173     mode, for example: \x{100}{2,3}.
3174    
3175     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3176     singly or repeated) now correctly test multibyte characters. However,
3177     PCRE doesn't recognize any characters with values greater than 255 as
3178     digits, spaces, or word characters. Such characters always match \D, \S,
3179     and \W, and never match \d, \s, or \w.
3180    
3181     (v) Classes may now contain characters and character ranges with values
3182     greater than 255. For example: [ab\x{100}-\x{400}].
3183    
3184     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3185     PCRE in UTF-8 mode.
3186    
3187     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3188     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3189     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3190     value.)
3191    
3192     53. The single man page has become too large. I have therefore split it up into
3193     a number of separate man pages. These also give rise to individual HTML pages;
3194     these are now put in a separate directory, and there is an index.html page that
3195     lists them all. Some hyperlinking between the pages has been installed.
3196    
3197     54. Added convenience functions for handling named capturing parentheses.
3198    
3199     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3200     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3201     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3202     are faulted.
3203    
3204     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3205     calling configure. These values are used when compiling the dftables.c program
3206     which is run to generate the source of the default character tables. They
3207     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3208     you will need to set these values.
3209    
3210     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3211    
3212    
3213     Version 3.9 02-Jan-02
3214 nigel 61 ---------------------
3215    
3216     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3217    
3218     2. If --disable-static was given, the building process failed when trying to
3219     build pcretest and pcregrep. (For some reason it was using libtool to compile
3220     them, which is not right, as they aren't part of the library.)
3221    
3222    
3223 nigel 59 Version 3.8 18-Dec-01
3224     ---------------------
3225    
3226     1. The experimental UTF-8 code was completely screwed up. It was packing the
3227     bytes in the wrong order. How dumb can you get?
3228    
3229    
3230 nigel 57 Version 3.7 29-Oct-01
3231     ---------------------
3232    
3233     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3234     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3235     this didn't happen under Solaris 8, where I normally test things.
3236    
3237 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3238     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3239     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3240     this fix an hour or so after the initial 3.7 release.)
3241 nigel 57
3242 nigel 59
3243 nigel 55 Version 3.6 23-Oct-01
3244     ---------------------
3245    
3246     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3247     offsets passed as NULL with zero offset count.
3248    
3249     2. The config.guess and config.sub files had not been updated when I moved to
3250     the latest autoconf.
3251    
3252    
3253 nigel 53 Version 3.5 15-Aug-01
3254     ---------------------
3255 nigel 5
3256 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3257     had been forgotten.
3258    
3259     2. By using declared but undefined structures, we can avoid using "void"
3260     definitions in pcre.h while keeping the internal definitions of the structures
3261     private.
3262    
3263     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3264     user point of view, this means that both static and shared libraries are built
3265     by default, but this can be individually controlled. More of the work of
3266     handling this static/shared cases is now inside libtool instead of PCRE's make
3267     file.
3268    
3269     4. The pcretest utility is now installed along with pcregrep because it is
3270     useful for users (to test regexs) and by doing this, it automatically gets
3271     relinked by libtool. The documentation has been turned into a man page, so
3272     there are now .1, .txt, and .html versions in /doc.
3273    
3274     5. Upgrades to pcregrep:
3275     (i) Added long-form option names like gnu grep.
3276     (ii) Added --help to list all options with an explanatory phrase.
3277     (iii) Added -r, --recursive to recurse into sub-directories.
3278     (iv) Added -f, --file to read patterns from a file.
3279    
3280     6. pcre_exec() was referring to its "code" argument before testing that
3281     argument for NULL (and giving an error if it was NULL).
3282    
3283     7. Upgraded Makefile.in to allow for compiling in a different directory from
3284     the source directory.
3285    
3286     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3287     options bits, the pointer it was passed was to an int instead of to an unsigned
3288     long int. This mattered only on 64-bit systems.
3289    
3290     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3291     generated) instead of pcre.in, which it its source. Also made the same change
3292     in several of the .c files.
3293    
3294     10. A new release of gcc defines printf() as a macro, which broke pcretest
3295     because it had an ifdef in the middle of a string argument for printf(). Fixed
3296     by using separate calls to printf().
3297    
3298     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3299     script, to force use of CR or LF instead of \n in the source. On non-Unix
3300     systems, the value can be set in config.h.
3301    
3302     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3303     absolute limit. Changed the text of the error message to make this clear, and
3304     likewise updated the man page.
3305    
3306     13. The limit of 99 on the number of capturing subpatterns has been removed.
3307     The new limit is 65535, which I hope will not be a "real" limit.
3308    
3309    
3310 nigel 51 Version 3.4 22-Aug-00
3311     ---------------------
3312    
3313     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3314    
3315     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3316    
3317    
3318 nigel 49 Version 3.3 01-Aug-00
3319     ---------------------
3320    
3321     1. If an octal character was given, but the value was greater than \377, it
3322     was not getting masked to the least significant bits, as documented. This could
3323     lead to crashes in some systems.
3324    
3325     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3326     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3327    
3328     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3329     These just pass their arguments on to (pcre_free)(), but they are provided
3330     because some uses of PCRE bind it to non-C systems that can call its functions,
3331     but cannot call free() or pcre_free() directly.
3332    
3333     4. Add "make test" as a synonym for "make check". Corrected some comments in
3334     the Makefile.
3335    
3336     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3337     Makefile.
3338    
3339     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3340     command called pgrep for grepping around the active processes.
3341    
3342     7. Added the beginnings of support for UTF-8 character strings.
3343    
3344     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3345     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3346     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3347     out for the ar command.)
3348    
3349    
3350 nigel 47 Version 3.2 12-May-00
3351     ---------------------
3352    
3353     This is purely a bug fixing release.
3354    
3355     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3356     of ZA. This was just one example of several cases that could provoke this bug,
3357     which was introduced by change 9 of version 2.00. The code for breaking
3358     infinite loops after an iteration that matches an empty string was't working
3359     correctly.
3360    
3361     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3362     when matched against abbab (for example). After matching an empty string, it
3363     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3364     caused it to match further down the string than it should.
3365    
3366     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3367     was there because it doesn't seem to be needed, and it causes trouble on some
3368     systems, as it is not a Standard C header. It has been removed.
3369    
3370     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3371     were reported on the Macintosh. The changes were from
3372    
3373     while ((c = *(++ptr)) != 0 && c != '\n');
3374     to
3375     while ((c = *(++ptr)) != 0 && c != '\n') ;
3376    
3377     Totally extraordinary, but if that's what it takes...
3378    
3379     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3380     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3381     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3382     assumes the way PCRE uses memmove() (always moving upwards).
3383    
3384     6. PCRE is being used in one environment where strchr() is not available. There
3385     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3386     faster code anyway.
3387    
3388    
3389 nigel 45 Version 3.1 09-Feb-00
3390     ---------------------
3391    
3392     The only change in this release is the fixing of some bugs in Makefile.in for
3393     the "install" target:
3394    
3395     (1) It was failing to install pcreposix.h.
3396    
3397     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3398    
3399    
3400 nigel 43 Version 3.0 01-Feb-00
3401     ---------------------
3402 nigel 41
3403     1. Add support for the /+ modifier to perltest (to output $` like it does in
3404     pcretest).
3405    
3406     2. Add support for the /g modifier to perltest.
3407    
3408     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3409     matches null strings.
3410    
3411     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3412     pattern. Perl treats empty patterns specially - it reuses the most recent
3413     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3414     effect.
3415    
3416     5. The POSIX interface was broken in that it was just handing over the POSIX
3417     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3418     required a bigger vector, with some working space on the end. This means that
3419     the POSIX wrapper now has to get and free some memory, and copy the results.
3420    
3421 nigel 43 6. Added some simple autoconf support, placing the test data and the
3422     documentation in separate directories, re-organizing some of the
3423     information files, and making it build pcre-config (a GNU standard). Also added
3424     libtool support for building PCRE as a shared library, which is now the
3425     default.
3426 nigel 41
3427 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3428     09 are not valid octal constants. Single digits will be used for minor values
3429     less than 10.
3430    
3431     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3432     existing programs that set these in the POSIX interface can use PCRE without
3433     modification.
3434    
3435     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3436     return all that pcre_info() returns, plus additional data. The pcre_info()
3437     function is retained for compatibility, but is considered to be obsolete.
3438    
3439     10. Added experimental recursion feature (?R) to handle one common case that
3440     Perl 5.6 will be able to do with (?p{...}).
3441    
3442     11. Added support for POSIX character classes like [:alpha:], which Perl is
3443     adopting.
3444    
3445    
3446 nigel 39 Version 2.08 31-Aug-99
3447     ----------------------
3448    
3449     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3450     trying to match at the startoffset position, but instead was moving forward to
3451     the next newline as if a previous match had failed.
3452    
3453     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3454     and could get into a loop if a null string was matched other than at the start
3455     of the subject.
3456    
3457     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3458     be distinguished at compile time, and for completeness also added PCRE_DATE.
3459    
3460     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3461     in GnuWin32 environments.
3462    
3463    
3464 nigel 37 Version 2.07 29-Jul-99
3465     ----------------------
3466    
3467     1. The documentation is now supplied in plain text form and HTML as well as in
3468     the form of man page sources.
3469    
3470     2. C++ compilers don't like assigning (void *) values to other pointer types.
3471     In particular this affects malloc(). Although there is no problem in Standard
3472     C, I've put in casts to keep C++ compilers happy.
3473    
3474     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3475     should be (const char *).
3476    
3477     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3478     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3479     However, I haven't made this a standard facility. The documentation doesn't
3480     mention it, and the Makefile doesn't support it.
3481    
3482     5. The Makefile now contains an "install" target, with editable destinations at
3483     the top of the file. The pcretest program is not installed.
3484    
3485     6. pgrep -V now gives the PCRE version number and date.
3486    
3487     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3488     causing the entire string to be ignored, instead of just the last character.
3489    
3490     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3491     non-matching string, it can take a very, very long time, even for strings of
3492     quite modest length, because of the nested recursion. PCRE now does better in
3493     some of these cases. It does this by remembering the last required literal
3494     character in the pattern, and pre-searching the subject to ensure it is present
3495     before running the real match. In other words, it applies a heuristic to detect
3496     some types of certain failure quickly, and in the above example, if presented
3497     with a string that has no trailing " it gives "no match" very quickly.
3498    
3499     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3500     other alternatives are tried instead.
3501    
3502    
3503 nigel 35 Version 2.06 09-Jun-99
3504     ----------------------
3505    
3506     1. Change pcretest's output for amount of store used to show just the code
3507     space, because the remainder (the data block) varies in size between 32-bit and
3508     64-bit systems.
3509    
3510     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3511     start matching at. This allows lookbehinds to work when searching for multiple
3512     occurrences in a string.
3513    
3514     3. Added additional options to pcretest for testing multiple occurrences:
3515    
3516     /+ outputs the rest of the string that follows a match
3517     /g loops for multiple occurrences, using the new startoffset argument
3518     /G loops for multiple occurrences by passing an incremented pointer
3519    
3520     4. PCRE wasn't doing the "first character" optimization for patterns starting
3521     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3522     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3523     the letter 'x'. On long subject strings, this gives a significant speed-up.
3524    
3525    
3526 nigel 33 Version 2.05 21-Apr-99
3527     ----------------------
3528    
3529     1. Changed the type of magic_number from int to long int so that it works
3530     properly on 16-bit systems.
3531    
3532     2. Fixed a bug which caused patterns starting with .* not to work correctly
3533     when the subject string contained newline characters. PCRE was assuming
3534     anchoring for such patterns in all cases, which is not correct because .* will
3535     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3536     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3537     must be retried after every newline in the subject.
3538    
3539    
3540 nigel 31 Version 2.04 18-Feb-99
3541     ----------------------
3542    
3543     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3544     computation of the store needed to hold the pattern was incorrect (too large).
3545     If such patterns were nested a few deep, this could multiply and become a real
3546     problem.
3547    
3548     2. Added /M option to pcretest to show the memory requirement of a specific
3549     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3550    
3551     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3552     compiled in such a way that the backtracking after subsequent failure was
3553     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3554     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3555    
3556    
3557 nigel 29 Version 2.03 02-Feb-99
3558     ----------------------
3559    
3560     1. Fixed typo and small mistake in man page.
3561    
3562 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3563     LICENCE file containing the conditions.
3564 nigel 29
3565     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3566     Perl, that is the internal \ allows the delimiter to be included in the
3567     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3568     the final delimiter, add \ to the end of the pattern (to test the error).
3569    
3570     4. Added the convenience functions for extracting substrings after a successful
3571     match. Updated pcretest to make it able to test these functions.
3572    
3573    
3574 nigel 27 Version 2.02 14-Jan-99
3575     ----------------------
3576    
3577     1. Initialized the working variables associated with each extraction so that
3578     their saving and restoring doesn't refer to uninitialized store.
3579    
3580     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3581     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3582     fix the problem.
3583    
3584     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3585     calls, and wasn't printing the correct value for compiling calls. Increased the
3586     default value of LOOPREPEAT, and the number of significant figures in the
3587     times.
3588    
3589     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3590    
3591     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3592     a building problem on Windows NT with a FAT file system.
3593    
3594    
3595 nigel 25 Version 2.01 21-Oct-98
3596     ----------------------
3597    
3598     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3599     to character tables built by pcre_maketables() in the current locale. If NULL
3600     is passed, the default tables are used.
3601    
3602    
3603 nigel 23 Version 2.00 24-Sep-98
3604 nigel 21 ----------------------
3605    
3606 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3607     it any more.
3608    
3609     2. Allow quantification of (?>) groups, and make it work correctly.
3610    
3611     3. The first character computation wasn't working for (?>) groups.
3612    
3613     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3614     end of the subject) and add 5.005's \z, which really does match only at the
3615     very end of the subject.
3616    
3617     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3618    
3619     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3620     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3621     localized options. All options to pcre_study() were also removed.
3622    
3623     7. Add other new features from 5.005:
3624    
3625     $(?<= positive lookbehind
3626     $(?<! negative lookbehind
3627     (?imsx-imsx) added the unsetting capability
3628     such a setting is global if at outer level; local otherwise
3629     (?imsx-imsx:) non-capturing groups with option setting
3630     (?(cond)re|re) conditional pattern matching
3631    
3632     A backreference to itself in a repeated group matches the previous
3633     captured string.
3634    
3635     8. General tidying up of studying (both automatic and via "study")
3636     consequential on the addition of new assertions.
3637    
3638     9. As in 5.005, unlimited repeated groups that could match an empty substring
3639     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3640     runtime if any iteration does actually match an empty substring.
3641    
3642     10. Include the RunTest script in the distribution.
3643    
3644     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3645     discrepancies, some of which were old and were also with respect to 5.004. They
3646     have now been fixed.
3647    
3648    
3649     Version 1.09 28-Apr-98
3650     ----------------------
3651    
3652 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3653     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3654     program crashes, or just wrong answers. This did not apply to negated classes
3655     containing more than one character, or to minima other than one.
3656    
3657    
3658 nigel 19 Version 1.08 27-Mar-98
3659     ----------------------
3660    
3661     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3662    
3663     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3664     latter must appear before anything that relies on it in the pattern.
3665    
3666    
3667 nigel 17 Version 1.07 16-Feb-98
3668     ----------------------
3669    
3670     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3671     repeat of a potentially empty string).
3672    
3673    
3674 nigel 15 Version 1.06 23-Jan-98
3675     ----------------------
3676    
3677     1. Added Markus Oberhumer's little patches for C++.
3678    
3679     2. Literal strings longer than 255 characters were broken.
3680    
3681    
3682 nigel 13 Version 1.05 23-Dec-97
3683     ----------------------
3684    
3685     1. Negated character classes containing more than one character were failing if
3686     PCRE_CASELESS was set at run time.
3687    
3688    
3689 nigel 11 Version 1.04 19-Dec-97
3690     ----------------------
3691    
3692     1. Corrected the man page, where some "const" qualifiers had been omitted.
3693    
3694     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3695     input syntax.
3696    
3697     3. Fixed memory leak which occurred when a regex with back references was
3698     matched with an offsets vector that wasn't big enough. The temporary memory
3699     that is used in this case wasn't being freed if the match failed.
3700    
3701     4. Tidied pcretest to ensure it frees memory that it gets.
3702    
3703     5. Temporary memory was being obtained in the case where the passed offsets
3704     vector was exactly big enough.
3705    
3706     6. Corrected definition of offsetof() from change 5 below.
3707    
3708     7. I had screwed up change 6 below and broken the rules for the use of
3709     setjmp(). Now fixed.
3710    
3711    
3712 nigel 9 Version 1.03 18-Dec-97
3713     ----------------------
3714    
3715     1. A erroneous regex with a missing opening parenthesis was correctly
3716     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3717     on some systems.
3718    
3719     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3720     it was reported that one broken compiler failed on the former because "code" is
3721     also an independent variable.