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Revision 541 - (hide annotations) (download)
Mon Jun 14 15:19:33 2010 UTC (4 years, 2 months ago) by ph10
File size: 189290 byte(s)
Add /T option to pcretest and additional tests with non-standard tables.

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