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Revision 581 - (hide annotations) (download)
Fri Dec 10 11:40:00 2010 UTC (4 years, 2 months ago) by ph10
File size: 196599 byte(s)
Final tidies for 8.11 release.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 581 Version 8.11 10-Dec-2010
5 ph10 550 ------------------------
7     1. (*THEN) was not working properly if there were untried alternatives prior
8 ph10 579 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9     backtracked to try for "b" instead of moving to the next alternative branch
10     at the same level (in this case, to look for "c"). The Perl documentation
11     is clear that when (*THEN) is backtracked onto, it goes to the "next
12 ph10 550 alternative in the innermost enclosing group".
13 ph10 579
14     2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15 ph10 551 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
16     result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17 ph10 579 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18     (*THEN).
20 ph10 552 3. If \s appeared in a character class, it removed the VT character from
21     the class, even if it had been included by some previous item, for example
22 ph10 579 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
23     of \s, but is part of the POSIX "space" class.)
25 ph10 553 4. A partial match never returns an empty string (because you can always
26     match an empty string at the end of the subject); however the checking for
27     an empty string was starting at the "start of match" point. This has been
28     changed to the "earliest inspected character" point, because the returned
29     data for a partial match starts at this character. This means that, for
30     example, /(?<=abc)def/ gives a partial match for the subject "abc"
31     (previously it gave "no match").
32 ph10 550
33 ph10 553 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
34 ph10 579 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
35 ph10 553 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
36 ph10 579 has an implication that the given string is incomplete (because a partial
37     match is preferred over a full match). For this reason, these items now
38 ph10 553 give a partial match in this situation. [Aside: previously, the one case
39     /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
40 ph10 579 match rather than a full match, which was wrong by the old rules, but is
41     now correct.]
43 ph10 556 6. There was a bug in the handling of #-introduced comments, recognized when
44     PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
45     If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
46     UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
47     scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
48 ph10 579 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
49 ph10 556 places in pcre_compile().
50 ph10 579
51     7. Related to (6) above, when pcre_compile() was skipping #-introduced
52     comments when looking ahead for named forward references to subpatterns,
53     the only newline sequence it recognized was NL. It now handles newlines
54 ph10 556 according to the set newline convention.
55 ph10 579
56     8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
57     former, but used strtoul(), whereas pcretest avoided strtoul() but did not
58 ph10 558 cater for a lack of strerror(). These oversights have been fixed.
59 ph10 550
60 ph10 579 9. Added --match-limit and --recursion-limit to pcregrep.
62 ph10 563 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
63 ph10 553
64 ph10 564 11. When the -o option was used, pcregrep was setting a return code of 1, even
65     when matches were found, and --line-buffered was not being honoured.
66 ph10 579
67 ph10 565 12. Added an optional parentheses number to the -o and --only-matching options
68 ph10 579 of pcregrep.
70 ph10 566 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
71 ph10 579 can match an empty string. The code to do it in pcretest and pcredemo
72 ph10 566 needed fixing:
73 ph10 579
74 ph10 566 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
75     only one byte after an empty string match just before CRLF (this case
76     just got forgotten; "any" and "anycrlf" were OK).
77 ph10 579
78 ph10 566 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
79 ph10 579 mode when an empty string match preceded an ASCII character followed by
80 ph10 566 a non-ASCII character. (The code for advancing by one character rather
81 ph10 579 than one byte was nonsense.)
83 ph10 566 (c) The pcredemo.c sample program did not have any code at all to handle
84 ph10 579 the cases when CRLF is a valid newline sequence.
86 ph10 567 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
87     as a starting offset was within the subject string. There is now a new
88 ph10 579 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
89     negative or greater than the length of the string. In order to test this,
90 ph10 567 pcretest is extended to allow the setting of negative starting offsets.
91 ph10 579
92     15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
93     starting offset points to the beginning of a UTF-8 character was
94     unnecessarily clumsy. I tidied it up.
96 ph10 569 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
97 ph10 579 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
99     17. Nobody had reported that the --include_dir option, which was added in
100     release 7.7 should have been called --include-dir (hyphen, not underscore)
101     for compatibility with GNU grep. I have changed it to --include-dir, but
102     left --include_dir as an undocumented synonym, and the same for
103     --exclude-dir, though that is not available in GNU grep, at least as of
104     release 2.5.4.
106     18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
107 ph10 573 characters from a string of bytes) have been redefined so as not to use
108 ph10 579 loops, in order to improve performance in some environments. At the same
109     time, I abstracted some of the common code into auxiliary macros to save
110 ph10 573 repetition (this should not affect the compiled code).
111 ph10 579
112     19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
113     compile-time error is now given if \c is not followed by an ASCII
114     character, that is, a byte less than 128. (In EBCDIC mode, the code is
115 ph10 574 different, and any byte value is allowed.)
116 ph10 579
117 ph10 576 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
118     START_OPTIMIZE option, which is now allowed at compile time - but just
119     passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
120 ph10 579 to pcregrep and other applications that have no direct access to PCRE
121     options. The new /Y option in pcretest sets this option when calling
122     pcre_compile().
124 ph10 578 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
125 ph10 579 back references. Groups containing recursive back references were forced to
126     be atomic by that change, but in the case of named groups, the amount of
127     memory required was incorrectly computed, leading to "Failed: internal
128     error: code overflow". This has been fixed.
129 ph10 563
130 ph10 580 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
131     pcretest.c, to avoid build problems in some Borland environments.
132 ph10 564
133 ph10 580
134 ph10 548 Version 8.10 25-Jun-2010
135 ph10 510 ------------------------
137 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
138 ph10 510 THEN.
140 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
141 ph10 510
142 ph10 535 3. Inside a character class, \B is treated as a literal by default, but
143     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
144 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
145 ph10 535
146     4. Inside a character class, PCRE always treated \R and \X as literals,
147 ph10 513 whereas Perl faults them if its -w option is set. I have changed PCRE so
148     that it faults them when PCRE_EXTRA is set.
149 ph10 535
150 ph10 514 5. Added support for \N, which always matches any character other than
151     newline. (It is the same as "." when PCRE_DOTALL is not set.)
152 ph10 535
153 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
154 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
155 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
156 ph10 535 result to (void) does not stop the warnings; a more elaborate fudge is
157     needed. I've used a macro to implement this.
158 ph10 512
159 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
161 ph10 517 8. Added four artifical Unicode properties to help with an option to make
162 ph10 518 \s etc use properties (see next item). The new properties are: Xan
163     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
164 ph10 535
165 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
166 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
167 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
168     REG_UCP to make it available via the POSIX interface.
169 ph10 513
170 ph10 535 10. Added --line-buffered to pcregrep.
172     11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
173     studied, and the match started with a letter with a code point greater than
174 ph10 520 127 whose first byte was different to the first byte of the other case of
175 ph10 545 the letter, the other case of this starting letter was not recognized
176 ph10 536 (#976).
177 ph10 535
178 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
179 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
180 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
181     not have actually happened in practice until change 8 above was made (it
182 ph10 523 added property types that matched character-matching opcodes).
183 ph10 535
184 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
185 ph10 535 possible starting bytes for non-anchored patterns.
187 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
188 ph10 535 \R, and also a number of cases that involve Unicode properties, both
189 ph10 532 explicit and implicit when PCRE_UCP is set.
190 ph10 529
191 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
192 ph10 535 input, it could crash or give wrong results if characters with values
193     greater than 0xc0 were present in the subject string. (Detail: it assumed
194 ph10 529 UTF-8 input when processing these items.)
195 ph10 535
196 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
197     size_t is 64-bit (#991).
198 ph10 535
199 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
200     --disable-stack-for-recursion (#990).
201 ph10 545
202 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
203 ph10 545 the end, a newline was missing in the output.
205     19. The default pcre_chartables.c file recognizes only ASCII characters (values
206     less than 128) in its various bitmaps. However, there is a facility for
207     generating tables according to the current locale when PCRE is compiled. It
208     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
209     characters, are recognized by isspace() and therefore were getting set in
210 ph10 541 these tables, and indeed these tables seem to approximate to ISO 8859. This
211     caused a problem in UTF-8 mode when pcre_study() was used to create a list
212     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
213     which of course cannot start UTF-8 characters. I have changed the code so
214     that only real ASCII characters (less than 128) and the correct starting
215 ph10 545 bytes for UTF-8 encodings are set for characters greater than 127 when in
216 ph10 541 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
217     altogether.)
218 ph10 545
219 ph10 541 20. Added the /T option to pcretest so as to be able to run tests with non-
220     standard character tables, thus making it possible to include the tests
221 ph10 545 used for 19 above in the standard set of tests.
223     21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
224     reference to a subpattern the other side of a comment that contains an
225     opening parenthesis caused either an internal compiling error, or a
226 ph10 544 reference to the wrong subpattern.
227 ph10 517
228 ph10 520
229 ph10 508 Version 8.02 19-Mar-2010
230 ph10 491 ------------------------
232     1. The Unicode data tables have been updated to Unicode 5.2.0.
234 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
235     configured.
236 ph10 507
237 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
238 ph10 507 original author of that file, following a query about its status.
240     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
241 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
242 ph10 507
243 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
244     quantifier applied to a forward-referencing subroutine call, could compile
245     incorrect code or give the error "internal error: previously-checked
246     referenced subpattern not found".
247 ph10 507
248     6. Both MS Visual Studio and Symbian OS have problems with initializing
249 ph10 497 variables to point to external functions. For these systems, therefore,
250     pcre_malloc etc. are now initialized to local functions that call the
251     relevant global functions.
252 ph10 507
253 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
254     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
255 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
256     the lengths are correct (equal to the number of opcodes).
258     8. Following on from 7, I added a similar kludge to check the length of the
259     eint vector in pcreposix.c.
261     9. Error texts for pcre_compile() are held as one long string to avoid too
262     much relocation at load time. To find a text, the string is searched,
263 ph10 499 counting zeros. There was no check for running off the end of the string,
264     which could happen if a new error number was added without updating the
265 ph10 507 string.
267     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
269 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
270 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
271     \K is "not well defined" if used in an assertion. PCRE now accepts it if
272     the assertion is positive, but not if it is negative.
274 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
275 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
276     implementation of support for (*MARK) will need an extra pointer on the
277 ph10 501 stack; I have reserved it now, so that the stack frame size does not
278     decrease.
279 ph10 507
280     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
281     item in branch that calls a recursion is a subroutine call - as in the
282 ph10 503 second branch in the above example - was incorrectly given the compile-
283     time error "recursive call could loop indefinitely" because pcre_compile()
284 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
286 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
287 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
288 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
289 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
290 ph10 491
291 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
292 ph10 492
293 ph10 507
294 ph10 489 Version 8.01 19-Jan-2010
295     ------------------------
296 ph10 471
297     1. If a pattern contained a conditional subpattern with only one branch (in
298 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
299 ph10 473 computed the wrong minimum data length (which is of course zero for such
300 ph10 489 subpatterns). This could cause incorrect "no match" results.
301 ph10 473
302     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
303 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
304     "internal error: code overflow at offset...". This happened only when
305 ph10 473 the reset was to the original external option setting. (An optimization
306     abstracts leading options settings into an external setting, which was the
307 ph10 472 cause of this.)
308 ph10 471
309 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
310     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
311     assertion pattern did not match (meaning that the assertion was true), it
312     was incorrectly treated as false if the SKIP had been reached during the
313     matching. This also applied to assertions used as conditions.
314 ph10 471
315 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
316     assertion subpattern, including such a pattern used as a condition,
317     unpredictable results occurred, instead of the error return
319 ph10 478
320 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
321     situation when an empty string is matched. It now does the fancy magic
322 ph10 478 stuff that is necessary.
324     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
325 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
326 ph10 478
327 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
328     as part of something else:
329 ph10 478
330     (a) Change DEBUG to PCRE_DEBUG.
332     (b) In pcre_compile(), rename the member of the "branch_chain" structure
333     called "current" as "current_branch", to prevent a collision with the
334 ph10 475 Linux macro when compiled as a kernel module.
335 ph10 478
336     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
337     prevent a collision with the Linux macro when compiled as a kernel
338 ph10 475 module.
339 ph10 478
340 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
341     cast potentially large values to (double). This has been changed to that
342 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
343     instead, thus avoiding the use of floating point arithmetic. (There is no
344     other use of FP in PCRE.) If int64_t is not found, the fallback is to
345     double.
347     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
348 ph10 476 2005 (difference between two addresses compared to an unsigned value).
349 ph10 473
350 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
351     custom one, because of the following reported problem in Windows:
352 ph10 473
353 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
354 ph10 489 under Win32.
355 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
356 ph10 489 therefore missing the function definition.
357 ph10 478 - The compiler thus generates a "C" signature for the test function.
358     - The linker fails to find the "C" function.
359     - PCRE fails to configure if asked to do so against libbz2.
360 ph10 486
361 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
362     messages were output:
363 ph10 478
364 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
365     rerunning libtoolize, to keep the correct libtool macros in-tree.
366     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
367 ph10 486
368 ph10 479 I have done both of these things.
369 ph10 486
370 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
371 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
372     runaway infinite recursion. I updated the discussion in the pcrestack man
373     page.
375     13. Now that we have gone to the x.xx style of version numbers, the minor
376     version may start with zero. Using 08 or 09 is a bad idea because users
377     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
378     interpreted as invalid octal numbers. I've updated the previous comment in
379     configure.ac, and also added a check that gives an error if 08 or 09 are
380 ph10 481 used.
381 ph10 486
382 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
383 ph10 483 causing partial matching to fail when the end of the subject matched \W
384     in a UTF-8 pattern where \W was quantified with a minimum of 3.
385 ph10 486
386 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
387 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
388 ph10 483 their definitions. The declarations used "const uschar *" and the
389     definitions used USPTR. Even though USPTR is normally defined as "const
390     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
391     reported that: "This difference in casting confuses some C++ compilers, for
392     example, SunCC recognizes above declarations as different functions and
393 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
394 ph10 483 USPTR.
395 ph10 486
396     16. GNU libtool is named differently on some systems. The autogen.sh script now
397 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
398     (FreeBSD).
399 ph10 478
400 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
401     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
402     comment: "Figure out how to create a longlong from a string: strtoll and
403     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
404     instance, but it only takes 2 args instead of 3!"
405 ph10 479
406 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
407     specification, with a corresponding code fix. A pattern such as
408     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
409     refers, was giving matches when it shouldn't. For example, xa=xaaa would
410     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
411     same bug. Such groups have to be quantified to be useful, or contained
412     inside another quantified group. (If there's no repetition, the reference
413     can never match.) The problem arises because, having left the group and
414     moved on to the rest of the pattern, a later failure that backtracks into
415     the group uses the captured value from the final iteration of the group
416     rather than the correct earlier one. I have fixed this in PCRE by forcing
417     any group that contains a reference to itself to be an atomic group; that
418     is, there cannot be any backtracking into it once it has completed. This is
419     similar to recursive and subroutine calls.
420 ph10 486
421 ph10 488
422 ph10 469 Version 8.00 19-Oct-09
423 ph10 418 ----------------------
425     1. The table for translating pcre_compile() error codes into POSIX error codes
426 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
427     being within the table. This could lead to an OK return being given in
428 ph10 418 error.
429 ph10 461
430     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
431     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
432     in a Windows environment.
434 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
435     zero, as does GNU grep. However, pcregrep was also printing all files when
436     --files-with-matches was added. Now, when both options are given, it prints
437     counts only for those files that have at least one match. (GNU grep just
438 ph10 461 prints the file name in this circumstance, but including the count seems
439     more useful - otherwise, why use --count?) Also ensured that the
440 ph10 420 combination -clh just lists non-zero counts, with no names.
441 ph10 461
442     4. The long form of the pcregrep -F option was incorrectly implemented as
443     --fixed_strings instead of --fixed-strings. This is an incompatible change,
444     but it seems right to fix it, and I didn't think it was worth preserving
445     the old behaviour.
447     5. The command line items --regex=pattern and --regexp=pattern were not
448 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
449 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
450 ph10 422 which are compatible with GNU grep; these now work.
451 ph10 461
452     6. No libpcreposix.pc file was created for pkg-config; there was just
453 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
454 ph10 461
455 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
456 ph10 461 when UCP support is not needed, by modifying the Python script that
457 ph10 425 generates it from Unicode data files. This should not matter if the module
458     is correctly used as a library, but I received one complaint about 50K of
459     unwanted data. My guess is that the person linked everything into his
460     program rather than using a library. Anyway, it does no harm.
461 ph10 461
462 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
463 ph10 461 was a minimum greater than 1 for a wide character in a possessive
464 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
465     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
466     character. Chaos in the form of incorrect output or a compiling loop could
467     result.
468 ph10 461
469 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
470 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
471 ph10 426 partially matched by this function. In addition, if there are at least two
472 ph10 435 slots in the offset vector, the offset of the earliest inspected character
473     for the match and the offset of the end of the subject are set in them when
474 ph10 461 PCRE_ERROR_PARTIAL is returned.
476 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
477     synonymous with PCRE_PARTIAL, for backwards compatibility, and
478     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
479 ph10 462 and may be more useful for multi-segment matching.
480 ph10 461
481     11. Partial matching with pcre_exec() is now more intuitive. A partial match
482     used to be given if ever the end of the subject was reached; now it is
483     given only if matching could not proceed because another character was
484     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
485     string "Z", which now yields "no match" instead of "partial match". In the
486     case of pcre_dfa_exec(), "no match" is given if every matching path for the
487     final character ended with (*FAIL).
489 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
490 ph10 461 if the pattern had a "must contain" character that was already found in the
491 ph10 428 earlier partial match, unless partial matching was again requested. For
492     example, with the pattern /dog.(body)?/, the "must contain" character is
493     "g". If the first part-match was for the string "dog", restarting with
494 ph10 435 "sbody" failed. This bug has been fixed.
495 ph10 461
496     13. The string returned by pcre_dfa_exec() after a partial match has been
497     changed so that it starts at the first inspected character rather than the
498     first character of the match. This makes a difference only if the pattern
499     starts with a lookbehind assertion or \b or \B (\K is not supported by
500     pcre_dfa_exec()). It's an incompatible change, but it makes the two
501 ph10 435 matching functions compatible, and I think it's the right thing to do.
502 ph10 461
503 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
504 ph10 461 so that the demonstration program is easily available in environments where
505     PCRE has not been installed from source.
507 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
508 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
509     library.
510 ph10 461
511 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
512 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
513 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
514 ph10 433 these options useful.
515 ph10 461
516     17. If a caller to the POSIX matching function regexec() passes a non-zero
517 ph10 438 value for nmatch with a NULL value for pmatch, the value of
518 ph10 461 nmatch is forced to zero.
520 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
521 ph10 461 the diff command, as RunTest does. It now checks in the same way as
522 ph10 437 RunTest, and also checks for the -b option.
523 ph10 461
524 ph10 438 19. If an odd number of negated classes containing just a single character
525     interposed, within parentheses, between a forward reference to a named
526 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
527     an internal error, complaining that it could not find the referenced
528 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
529 ph10 461 [The bug was that it was starting one character too far in when skipping
530     over the character class, thus treating the ] as data rather than
531     terminating the class. This meant it could skip too much.]
533 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
534 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
535 ph10 442 to have an empty string match not at the start, even when the pattern is
536 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
538 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
539 ph10 461 than the maximum at the outer level, the higher number was returned, but
540     with unset values at the outer level. The correct (outer level) value is
541 ph10 446 now given.
542 ph10 461
543 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
544     PCRE did not set those parentheses (unlike Perl). I have now found a way to
545     make it do so. The string so far is captured, making this feature
546     compatible with Perl.
547 ph10 461
548     23. The tests have been re-organized, adding tests 11 and 12, to make it
549 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
550 ph10 461
551 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
552 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
553     does. Neither allows recursion.
555     25. I finally figured out how to implement a request to provide the minimum
556     length of subject string that was needed in order to match a given pattern.
557     (It was back references and recursion that I had previously got hung up
558     on.) This code has now been added to pcre_study(); it finds a lower bound
559 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
560     bound, but using it to avoid searching strings that are too short does give
561     some useful speed-ups. The value is available to calling programs via
562     pcre_fullinfo().
563 ph10 461
564 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
565     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
566     study optimizations had never been tested with that matching function.
567     Oops. What is worse, even when it was passed study data, there was a bug in
568     pcre_dfa_exec() that meant it never actually used it. Double oops. There
569     were also very few tests of studied patterns with pcre_dfa_exec().
570 ph10 461
571 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
572     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
573     on the other side of the coin, they are no longer allowed to have different
574     names, because these cannot be distinguished in PCRE, and this has caused
575     confusion. (This is a difference from Perl.)
576 ph10 461
577     28. When duplicate subpattern names are present (necessarily with different
578     numbers, as required by 27 above), and a test is made by name in a
579     conditional pattern, either for a subpattern having been matched, or for
580     recursion in such a pattern, all the associated numbered subpatterns are
581 ph10 459 tested, and the overall condition is true if the condition is true for any
582     one of them. This is the way Perl works, and is also more like the way
583     testing by number works.
584 ph10 418
585 ph10 461
586 ph10 412 Version 7.9 11-Apr-09
587 ph10 376 ---------------------
589 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
590 ph10 376 (pcretest), all targets were linked against these libraries. This included
591     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
592     libraries. This caused unwanted dependencies to be created. This problem
593 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
594 ph10 376 pcretest is linked with readline.
595 ph10 392
596 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
597     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
598     moved outside it again, because FALSE and TRUE are already defined in AIX,
599     but BOOL is not.
600 ph10 392
601     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
602 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
603 ph10 392
604 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
605     hyphens) following file names and line numbers when outputting matching
606 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
607 ph10 376 wording for the --colour (or --color) option.
608 ph10 392
609 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
610     was not coloured; this is different to GNU grep, so I have changed it to be
611     the same.
612 ph10 392
613 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
614 ph10 392 each matching line was coloured. Now it goes on to look for further matches
615     of any of the test patterns, which is the same behaviour as GNU grep.
617     7. A pattern that could match an empty string could cause pcregrep to loop; it
618     doesn't make sense to accept an empty string match in pcregrep, so I have
619 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
620     seems to be how GNU grep behaves.
621 ph10 392
622 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
623 ph10 392 start or after a newline", because the conditional assertion was not being
624     correctly handled. The rule now is that both the assertion and what follows
625     in the first alternative must satisfy the test.
627 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
628 ph10 399 condition was an assertion, PCRE could crash during matching, both with
629     pcre_exec() and pcre_dfa_exec().
630 ph10 392
631     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
632     used for matching.
634     11. Unicode property support in character classes was not working for
635 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
636 ph10 388
637 ph10 392 12. Added the -M command line option to pcretest.
639 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
640 ph10 389
641     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
642 ph10 390
643 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
644 ph10 390 wrapper.
645 ph10 392
646 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
647 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
648 ph10 391 string constants.
649 ph10 405
650 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
651     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
652 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
653     these, but not everybody uses configure.
655     19. A conditional group that had only one branch was not being correctly
656     recognized as an item that could match an empty string. This meant that an
657     enclosing group might also not be so recognized, causing infinite looping
658     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
659     with the subject "ab", where knowledge that the repeated group can match
660 ph10 396 nothing is needed in order to break the loop.
661 ph10 405
662 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
663 ph10 405 exec(), but without supplying a callout function, matching went wrong.
665     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
666     leak if the size of the offset vector was greater than 30. When the vector
667     is smaller, the saved offsets during recursion go onto a local stack
668     vector, but for larger vectors malloc() is used. It was failing to free
669     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
670 ph10 400 error, in fact).
671 ph10 405
672 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
673 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
674     problem, but was untidy.
675 ph10 376
676 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
677     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
678     included within another project.
679 ph10 411
680 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
681     slightly modified by me:
682 ph10 411
683     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
684     not building pcregrep.
686 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
687 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
689 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
690     duplicate group numbers, could behave incorrectly or give incorrect errors,
691     because when scanning forward to find the reference group, PCRE was not
692     taking into account the duplicate group numbers. A pattern such as
693     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
694 ph10 411
695     26. Changed a few more instances of "const unsigned char *" to USPTR, making
696     the feature of a custom pointer more persuasive (as requested by a user).
697 ph10 416
698 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
699 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
700     pre-defined.
701 ph10 392
702 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
704 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
705     in the configuration summary.
706 ph10 405
707 ph10 411
708 ph10 374 Version 7.8 05-Sep-08
709 ph10 349 ---------------------
711     1. Replaced UCP searching code with optimized version as implemented for Ad
712     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
713 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
714     to 5 times on some simple patterns that I tested. Permission was given to
715     distribute the MultiStage2.py script that generates the tables (it's not in
716     the tarball, but is in the Subversion repository).
717 ph10 349
718 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
719     scripts.
720 ph10 358
721 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
722     a group with a zero qualifier. The result of the study could be incorrect,
723 ph10 358 or the function might crash, depending on the pattern.
725     4. Caseless matching was not working for non-ASCII characters in back
726 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
727 ph10 358 It now works when Unicode Property Support is available.
729 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
730     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
731     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
732 ph10 358 truncation.
733 ph10 349
734 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
736 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
737     pointers, in case they are 64-bit values.
738 ph10 371
739     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
740     test 2 if it fails.
742 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
743 ph10 371 and a #define of that name to empty if it is not externally set. This is to
744     allow users of MSVC to set it if necessary.
746     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
747 ph10 359 the convenience functions in the pcre_get.c source file.
748 ph10 371
749 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
750     could cause overwriting and/or a crash. This command provoked a crash in
751 ph10 371 some environments:
753     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
755 ph10 360 This potential security problem was recorded as CVE-2008-2371.
756 ph10 371
757 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
758     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
759 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
760 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
761     pcretest so that it places the subject at the end of its malloc-ed buffer.
762 ph10 371
763 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
764 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
766 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
767 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
768     first line. This applied both to normal and DFA matching.
770 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
771 ph10 371 /^[^d]*?$/8 failed to match "abc".
772 ph10 351
773 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
775     17. Make it more clear in the documentation that values returned from
776 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
777 ph10 357
778 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
779 ph10 368
780 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
781     supplied by Stefan Weber. I made a further small update for 7.8 because
782 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
783     replaced by pcre_ucd.c.
784 ph10 371
785 ph10 373
786 ph10 347 Version 7.7 07-May-08
787 ph10 321 ---------------------
789     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
790 ph10 345 a string to a long long, pretend we don't even have a long long." This is
791 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
792 ph10 345
793 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
794     pre-7.6 versions, which defined a global no_arg variable instead of putting
795 ph10 332 it in the RE class. (See also #8 below.)
796 ph10 345
797     3. Remove a line of dead code, identified by coverity and reported by Nuno
798     Lopes.
800 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
801 ph10 321
802 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
803 ph10 345 of files, instead of just to the final components.
805 ph10 324 (2) If there was more than one level of directory, the subdirectories were
806     skipped unless they satisfied the include/exclude conditions. This is
807     inconsistent with GNU grep (and could even be seen as contrary to the
808     pcregrep specification - which I improved to make it absolutely clear).
809     The action now is always to scan all levels of directory, and just
810     apply the include/exclude patterns to regular files.
811 ph10 345
812 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
813 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
815 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
816 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
817 ph10 326 doesn't support NULs in patterns.
818 ph10 345
819     7. Added some missing "const"s to declarations of static tables in
820     pcre_compile.c and pcre_dfa_exec.c.
822 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
823 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
824 ph10 345 first patch. And a third patch - this was a messy problem.)
825 ph10 321
826 ph10 345 9. Applied Craig's patch to remove the use of push_back().
828 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
829     matching function regexec().
830 ph10 345
831     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
832     which, however, unlike Perl's \g{...}, are subroutine calls, not back
833 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
834     Oniguruma does).
835 ph10 345
836     12. Previously, a group with a zero repeat such as (...){0} was completely
837 ph10 335 omitted from the compiled regex. However, this means that if the group
838     was called as a subroutine from elsewhere in the pattern, things went wrong
839 ph10 345 (an internal error was given). Such groups are now left in the compiled
840     pattern, with a new opcode that causes them to be skipped at execution
841 ph10 335 time.
842 ph10 345
843 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
844     to the way PCRE behaves:
845 ph10 345
846 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
847 ph10 345
848     (b) A back reference to an unmatched subpattern matches an empty string
849 ph10 336 (Perl fails the current match path).
850 ph10 345
851 ph10 341 (c) A data ] in a character class must be notated as \] because if the
852 ph10 345 first data character in a class is ], it defines an empty class. (In
853 ph10 341 Perl it is not possible to have an empty class.) The empty class []
854     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
855     The negative empty class [^] matches any one character, independently
856     of the DOTALL setting.
857 ph10 345
858     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
859 ph10 340 non-existent subpattern following a character class starting with ']' and
860     containing () gave an internal compiling error instead of "reference to
861     non-existent subpattern". Fortunately, when the pattern did exist, the
862 ph10 345 compiled code was correct. (When scanning forwards to check for the
863 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
864 ph10 345 the class, so got the count wrong. When actually compiling, the reference
865 ph10 340 was subsequently set up correctly.)
866 ph10 345
867 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
868 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
869     other assertions are supported. I have made pcre_dfa_exec() support
870     (*FAIL).
872 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
873 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
874     cannot be changed at match time, I realized I could make a small
875     improvement to matching performance by compiling OP_ALLANY instead of
876     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
877     on the OP_ANY path.
879     17. Compiling pcretest on Windows with readline support failed without the
880 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
881 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
883 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
884 ph10 345 ncurses library to be included for pcretest when ReadLine support is
885     requested, but also to allow for it to be overridden. This patch came from
886     Daniel Bergström.
887 ph10 347
888 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
889 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
890     any errors with the current Unicode tables. Thanks to Peter Kankowski for
891     spotting this.
892 ph10 324
893 ph10 332
894 ph10 319 Version 7.6 28-Jan-08
895 ph10 300 ---------------------
897 ph10 302 1. A character class containing a very large number of characters with
898     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
899     overflow.
900 ph10 309
901     2. Patch to cut out the "long long" test in pcrecpp_unittest when
902     HAVE_LONG_LONG is not defined.
904 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
905 ph10 304 bring them up to date and include new features. This patch includes:
906 ph10 309
907 ph10 304 - Fixed PH's badly added libz and libbz2 support.
908     - Fixed a problem with static linking.
909 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
910 ph10 304 - Fixed dftables problem and added an option.
911     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
913     - Added readline support for pcretest.
914 ph10 309 - Added an listing of the option settings after cmake has run.
916 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
917     "pcre.dll" under mingw when using Configure/Make. I added stuff to
918     Makefile.am that cause it to include this special target, without
919     affecting anything else. Note that the same mingw target plus all
920     the other distribution libraries and programs are now supported
921     when configuring with CMake (see 6 below) instead of with
922     Configure/Make.
923 ph10 309
924 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
925     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
926 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
927     solves the problem, but it does no harm.
928 ph10 313
929 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
930 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
931 ph10 314 with CMake, and also correct the comment about stack recursion.
932 ph10 313
933 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
934 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
935     of a program that users should build themselves after PCRE is installed, so
936     building it automatically is not really right. What is more, it gave
937 ph10 312 trouble in some build environments.
938 ph10 300
939 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
940 ph10 308
941 ph10 319
942 ph10 298 Version 7.5 10-Jan-08
943 ph10 263 ---------------------
945     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
946     values in parens when parsing an RE using the C++ wrapper."
947 ph10 286
948 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
949     Characters greater than 255 were excluded from the class instead of being
950     included.
951 ph10 286
952     3. The same bug as (2) above applied to negated POSIX classes such as
953 ph10 265 [:^space:].
954 ph10 286
955 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
956     defined or documented. It seems to have been a typo for PCRE_STATIC, so
957 ph10 286 I have changed it.
959 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
960 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
961     first named subpattern whose name started with "a" (in other words, the
962 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
963     expected" is now given for (?&) (a zero-length name), and this patch also
964     makes it give the same error for \k'' (previously it complained that that
965     was a reference to a non-existent subpattern).
966 ph10 286
967 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
968 ph10 286 this is right because (?- can be followed by option settings as well as by
969 ph10 269 digits. I have, however, made the messages clearer.
970 ph10 286
971 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
972     than the number used in the conditional) now cause a compile-time error.
973     This is actually not compatible with Perl, which accepts such patterns, but
974     treats the conditional as always being FALSE (as PCRE used to), but it
975     seems to me that giving a diagnostic is better.
976 ph10 286
977 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
978 ph10 275 and messages.
979 ph10 286
980     9. Fix two occurrences of "backslash" in comments that should have been
981     "backspace".
983     10. Remove two redundant lines of code that can never be obeyed (their function
984     was moved elsewhere).
986     11. The program that makes PCRE's Unicode character property table had a bug
987     which caused it to generate incorrect table entries for sequences of
988 ph10 277 characters that have the same character type, but are in different scripts.
989 ph10 286 It amalgamated them into a single range, with the script of the first of
990 ph10 277 them. In other words, some characters were in the wrong script. There were
991     thirteen such cases, affecting characters in the following ranges:
992 ph10 286
993 ph10 277 U+002b0 - U+002c1
994     U+0060c - U+0060d
995 ph10 286 U+0061e - U+00612
996 ph10 277 U+0064b - U+0065e
997     U+0074d - U+0076d
998     U+01800 - U+01805
999     U+01d00 - U+01d77
1000     U+01d9b - U+01dbf
1001     U+0200b - U+0200f
1002     U+030fc - U+030fe
1003     U+03260 - U+0327f
1004     U+0fb46 - U+0fbb1
1005     U+10450 - U+1049d
1006 ph10 286
1007 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
1008     compatible with GNU grep in that, if there was more than one match in a
1009     line, it showed only the first of them. It now behaves in the same way as
1010     GNU grep.
1011 ph10 286
1012     13. If the -o and -v options were combined for pcregrep, it printed a blank
1013     line for every non-matching line. GNU grep prints nothing, and pcregrep now
1014     does the same. The return code can be used to tell if there were any
1015     non-matching lines.
1017 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
1019     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1020 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
1021 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
1022     and both kinds of lookbehind were skipped).
1024 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1025 ph10 284 inclusion of <windows.h> to before rather than after the definition of
1026     INVALID_FILE_ATTRIBUTES (patch from David Byron).
1027 ph10 263
1028 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
1029 ph10 286 character property caused pcre_compile() to compile bad code, which led at
1030     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1031     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1032     caused the error; without that there was no problem.
1033 ph10 263
1034 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1035 ph10 286
1036 ph10 289 19. Added --enable-pcretest-libreadline.
1037 ph10 286
1038 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1039 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
1040 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
1041     later patch that removed the other one (the right fix) and added unit tests
1042     that check the return values (which was not done before).
1043 ph10 292
1044 ph10 291 21. Several CMake things:
1045 ph10 287
1046 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1047 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
1048 ph10 288
1049 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
1050     linked with the newly-built libraries, not previously installed ones.
1051 ph10 291
1053 ph10 298
1054     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1055     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1056     UTF-8 newline character). The key issue is that the pattern starts .*;
1057     this means that the match must be either at the beginning, or after a
1058     newline. The bug was in the code for advancing after a failed match and
1059     checking that the new position followed a newline. It was not taking
1060 ph10 294 account of UTF-8 characters correctly.
1061 ph10 298
1062     23. PCRE was behaving differently from Perl in the way it recognized POSIX
1063     character classes. PCRE was not treating the sequence [:...:] as a
1064     character class unless the ... were all letters. Perl, however, seems to
1065     allow any characters between [: and :], though of course it rejects as
1066     unknown any "names" that contain non-letters, because all the known class
1067     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1068     for example, whereas PCRE did not - it did not recognize a POSIX character
1069     class. This seemed a bit dangerous, so the code has been changed to be
1070     closer to Perl. The behaviour is not identical to Perl, because PCRE will
1071     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1072     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1073     Perl does, and where it didn't before.
1075 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1076     Windows environments %n is disabled by default.
1077 ph10 292
1079 ph10 260 Version 7.4 21-Sep-07
1080 ph10 230 ---------------------
1082     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1083 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
1084     LF". That isn't really right - the whole point of the change was to try to
1085     help when there was an actual mention of one of the two characters. So now
1086     the change happens only if \r or \n (or a literal CR or LF) character is
1087 ph10 230 encountered.
1088 ph10 231
1089     2. The 32-bit options word was also used for 6 internal flags, but the numbers
1090     of both had grown to the point where there were only 3 bits left.
1091     Fortunately, there was spare space in the data structure, and so I have
1092     moved the internal flags into a new 16-bit field to free up more option
1093 ph10 230 bits.
1094 ph10 231
1095     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1096     but did not set the internal JCHANGED flag - either of these is enough to
1097     control the way the "get" function works - but the PCRE_INFO_JCHANGED
1098     facility is supposed to tell if (?J) was ever used, so now (?J) at the
1099 ph10 230 start sets both bits.
1101 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
1102     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1103 ph10 230
1104 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
1106     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1107 ph10 233 compatibility, even though it is no longer used.
1108 ph10 243
1109     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1110 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1111 ph10 259 windows.h file is present (where different names are used). [This was
1112 ph10 257 reversed later after testing - see 16 below.]
1113 ph10 243
1114     8. Changed all #include <config.h> to #include "config.h". There were also
1115 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
1116 ph10 243
1117 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
1118 ph10 243 sequence off the lines that it output.
1120     10. It was pointed out to me that arrays of string pointers cause lots of
1121     relocations when a shared library is dynamically loaded. A technique of
1122     using a single long string with a table of offsets can drastically reduce
1123     these. I have refactored PCRE in four places to do this. The result is
1124 ph10 240 dramatic:
1125 ph10 243
1126 ph10 240 Originally: 290
1127     After changing UCP table: 187
1128 ph10 243 After changing error message table: 43
1129 ph10 240 After changing table of "verbs" 36
1130     After changing table of Posix names 22
1131 ph10 243
1132 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
1133 ph10 247
1134 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1135 ph10 247 unicode-properties was also set.
1137 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1138 ph10 231
1139 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1140     checked only for CRLF.
1141 ph10 233
1142 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
1144 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1145 ph10 253
1146 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1147 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1148     entirely. This removes changes made in 7 above.
1149 ph10 256
1150 ph10 261 17. The CMake files have been updated, and there is now more information about
1151     building with CMake in the NON-UNIX-USE document.
1152 ph10 257
1153 ph10 261
1154 ph10 228 Version 7.3 28-Aug-07
1155 ph10 157 ---------------------
1157 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1158     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1159     brackets there is not right, since it causes compilers to look for an
1160     installed pcre.h, not the version that is in the source that is being
1161     compiled (which of course may be different). I have changed it back to:
1162 ph10 197
1163 ph10 189 #include "pcre.h"
1164 ph10 197
1165     I have a vague recollection that the change was concerned with compiling in
1166     different directories, but in the new build system, that is taken care of
1167     by the VPATH setting the Makefile.
1169 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1170     when the subject happened to end in the byte 0x85 (e.g. if the last
1171     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1172     characters but of course it shouldn't be taken as a newline when it is part
1173     of another character. The bug was that, for an unlimited repeat of . in
1174     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1175     characters when looking for a newline.
1176 ph10 197
1177     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1179     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1180     in debug output.
1182 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1183     long printing in the pcrecpp unittest when running under MinGW.
1184 ph10 189
1185 ph10 197 6. ESC_K was left out of the EBCDIC table.
1186 ph10 189
1187 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1188     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1189     limit also applies to "virtual nesting" when a pattern is recursive, and in
1190     this case 1000 isn't so big. I have been able to remove this limit at the
1191     expense of backing off one optimization in certain circumstances. Normally,
1192     when pcre_exec() would call its internal match() function recursively and
1193     immediately return the result unconditionally, it uses a "tail recursion"
1194     feature to save stack. However, when a subpattern that can match an empty
1195     string has an unlimited repetition quantifier, it no longer makes this
1196     optimization. That gives it a stack frame in which to save the data for
1197     checking that an empty string has been matched. Previously this was taken
1198     from the 1000-entry workspace that had been reserved. So now there is no
1199     explicit limit, but more stack is used.
1200 ph10 189
1201 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1202     syntax that is required for Windows, and which was going wrong for the
1203     pcreposix and pcrecpp parts of the library. These were overlooked when this
1204     problem was solved for the main library.
1205 ph10 197
1206 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1207     the size of patterns that contain repeated groups with explicit upper
1208     limits. As the maximum quantifier is 65535, the maximum group length was
1209     set at 30,000 so that the product of these two numbers did not overflow a
1210     32-bit integer. However, it turns out that people want to use groups that
1211     are longer than 30,000 bytes (though not repeat them that many times).
1212     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1213     made it possible to implement the integer overflow checks in a much more
1214     dynamic way, which I have now done. The artificial limitation on group
1215     length has been removed - we now have only the limit on the total length of
1216     the compiled pattern, which depends on the LINK_SIZE setting.
1217 ph10 208
1218     10. Fixed a bug in the documentation for get/copy named substring when
1219     duplicate names are permitted. If none of the named substrings are set, the
1220     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1221     empty string.
1223     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1224     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1225     because the ] is interpreted as the first data character and the
1226     terminating ] is not found. PCRE has been made compatible with Perl in this
1227     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1228     cause memory overwriting.
1230 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1231     string has been matched (to stop an infinite loop). It was not recognizing
1232 ph10 208 a conditional subpattern that could match an empty string if that
1233 ph10 206 subpattern was within another subpattern. For example, it looped when
1234 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1235 ph10 206 condition was not nested. This bug has been fixed.
1236 ph10 208
1237 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1238     past the start of the subject in the presence of bytes with the top bit
1239     set, for example "\x8aBCD".
1240 ph10 211
1241 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1242     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1243 ph10 200
1244 ph10 211 14. Optimized (?!) to (*FAIL).
1245 ph10 202
1246 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1247     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1248     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1249     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1250     does: it's just the validity check that is more restrictive.
1251 ph10 220
1252     16. Inserted checks for integer overflows during escape sequence (backslash)
1253     processing, and also fixed erroneous offset values for syntax errors during
1254     backslash processing.
1256 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1257 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1259 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1260     caused an overrun.
1261 ph10 220
1262     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1263     something other than just ASCII characters) inside a group that had an
1264     unlimited repeat caused a loop at compile time (while checking to see
1265     whether the group could match an empty string).
1267 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1268     [\P{Any}] did so. (Error in the code for printing property names.)
1269 ph10 210
1270 ph10 220 21. An orphan \E inside a character class could cause a crash.
1272     22. A repeated capturing bracket such as (A)? could cause a wild memory
1273 ph10 218 reference during compilation.
1274 ph10 220
1275     23. There are several functions in pcre_compile() that scan along a compiled
1276     expression for various reasons (e.g. to see if it's fixed length for look
1277 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1278 ph10 220 present in the pattern. These operators have additional parameters compared
1279     with \d, etc, and these were not being taken into account when moving along
1280 ph10 218 the compiled data. Specifically:
1281 ph10 220
1282     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1283     length.
1285     (b) An item such as \pL+ within a repeated group could cause crashes or
1286 ph10 218 loops.
1287 ph10 220
1288 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1289 ph10 220 "reference to non-existent subpattern" error.
1291 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1293 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1294 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1295 ph10 211
1296 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1297 ph10 218
1298 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1299 ph10 223 character were causing crashes (broken optimization).
1300 ph10 227
1301 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1302 ph10 227 \p or \P) caused a compile-time loop.
1304 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1305     break. For example, the unstudied pattern [\r\n]A does not match the string
1306     "\r\nA" because change 7.0/46 below moves the current point on by two
1307     characters after failing to match at the start. However, the pattern \nA
1308 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1309     the same is true. There doesn't seem any very clean way out of this, but
1310     what I have chosen to do makes the common cases work: PCRE now takes note
1311     of whether there can be an explicit match for \r or \n anywhere in the
1312     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1313     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1314     pattern has explicit CR or LF references.
1315 ph10 222
1316 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1317 ph10 223
1318 ph10 227
1319 ph10 189 Version 7.2 19-Jun-07
1320     ---------------------
1322 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1323     which is apparently normally available under Windows.
1324 ph10 159
1325     2. Re-jig the pcregrep tests with different newline settings in an attempt
1326     to make them independent of the local environment's newline setting.
1327 ph10 157
1328 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1329 ph10 165
1330 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1331     was not 2, because the output contained actual offsets. The recent new
1332 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1333     usable with all link sizes.
1335 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1336     stack recursion. This gives a massive performance boost under BSD, but just
1337 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1338 ph10 164 in all cases.
1339 ph10 172
1340 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1341 ph10 172
1342 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1343     recursion call. It refers to the nth most recently opened parentheses.
1344 ph10 172
1345 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1346 ph10 172 to be opened parentheses.
1348     (c) Conditions that refer to capturing parentheses can be specified
1349 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1350 ph10 172
1351 ph10 168 (d) \K resets the start of the current match so that everything before
1352 ph10 172 is not part of it.
1354 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1355 ph10 172
1356 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1357 ph10 172 reference syntax.
1358 ph10 182
1359 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1360 ph10 182 alternative starts with the same number.
1361 ph10 172
1362 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1364 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1367     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1368     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1369 ph10 170 for detecting groups that can match an empty string.
1370 ph10 159
1371 ph10 172 9. A pattern with a very large number of alternatives (more than several
1372     hundred) was running out of internal workspace during the pre-compile
1373     phase, where pcre_compile() figures out how much memory will be needed. A
1374     bit of new cunning has reduced the workspace needed for groups with
1375     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1376     workspace instead of running out of the 4096 that are available.
1377 ph10 182
1378 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1379 ph10 172
1380 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1381     The report of the bug said:
1382 ph10 182
1383 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1384     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1385 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1386 ph10 185
1387 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1388 ph10 185 it matched the wrong number of bytes.
1389 ph10 172
1390 ph10 179
1391 ph10 155 Version 7.1 24-Apr-07
1392 ph10 98 ---------------------
1394 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1395 ph10 122 that is more "standard", making use of automake and other Autotools. There
1396 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1397     on this.
1398 ph10 111
1399     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1400     for recursive directory scanning broke on some systems because the files
1401     are not scanned in any specific order and on different systems the order
1402     was different. A call to "sort" has been inserted into RunGrepTest for the
1403     approprate test as a short-term fix. In the longer term there may be an
1404 ph10 100 alternative.
1405 ph10 111
1406 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1407 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1408     people do their own conversions for various reasons). The problems
1409     concerned the use of low-level troff macros .br and .in. I have therefore
1410     removed all such uses from the man pages (some were redundant, some could
1411 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1412     HTML has been updated to handle .nf/.fi and to complain if it encounters
1413     .br or .in.
1414 ph10 111
1415 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1416 ph10 123 arranged for config.h to be included in the distribution, with the name
1417 ph10 111 config.h.generic, for the benefit of those who have to compile without
1418     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1420     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1421     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1422 ph10 127 makevp.bat for the current PCRE, using the additional files
1423 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1424 ph10 111
1425     6. A Windows user reported a minor discrepancy with test 2, which turned out
1426     to be caused by a trailing space on an input line that had got lost in his
1427 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1428 ph10 111
1429 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1430 ph10 111 that is needed.
1432 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1433     as "const" (a) because they are and (b) because it helps the PHP
1434     maintainers who have recently made a script to detect big data structures
1435 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1436     to update Builducptable as well, so it won't revert if ucptable.h is ever
1437 ph10 105 re-created.
1438 ph10 111
1439     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1440 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1441 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1442     support is not required. This saves 1.5-2K of code, which is important in
1443 ph10 107 some applications.
1444 ph10 111
1445 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1446 ph10 111 so as not to refer to the tables, even though these functions will never be
1447     called when UTF-8 support is disabled. Otherwise there are problems with a
1448     shared library.
1450 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1452     (a) It was defining its arguments as char * instead of void *.
1454 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1455     a long time ago when I wrote it, but is no longer the case.
1457 ph10 118 The emulated memove() is provided for those environments that have neither
1458 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1459 ph10 118 is clearly not the case, as these two bugs were recently reported.
1460 ph10 123
1461 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1462 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1463     pages, and it removes trailing spaces from listed files. It also creates
1464     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1465     case, it wraps all the #defines with #ifndefs. This script should be run
1466 ph10 111 before "make dist".
1467 ph10 123
1468 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1469     with Unicode property support.
1470 ph10 123
1471     (a) For a maximizing quantifier, if the two different cases of the
1472     character were of different lengths in their UTF-8 codings (there are
1473     some cases like this - I found 11), and the matching function had to
1474 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1475     were both the same length.
1476 ph10 123
1477     (b) When PCRE was configured to use the heap rather than the stack for
1478     recursion during matching, it was not correctly preserving the data for
1479     the other case of a UTF-8 character when checking ahead for a match
1480     while processing a minimizing repeat. If the check also involved
1481 ph10 115 matching a wide character, but failed, corruption could cause an
1482     erroneous result when trying to check for a repeat of the original
1483     character.
1484 ph10 123
1485 ph10 116 13. Some tidying changes to the testing mechanism:
1486 ph10 98
1487 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1488     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1489 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1490     this for UTF-8.) The configure.ac script no longer substitutes the
1491     relevant variables.
1493 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1494     with length and offset values. This means that the output is different
1495     for different internal link sizes. Test 2 is skipped for link sizes
1496     other than 2 because of this, bypassing the problem. Unfortunately,
1497     there was also a test in test 3 (the locale tests) that used /B and
1498 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1499     I have added a new /Z option to pcretest that replaces the length and
1500     offset values with spaces. This is now used to make test 3 independent
1501 ph10 122 of link size. (Test 2 will be tidied up later.)
1502 ph10 123
1503     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1504 ph10 122 segmentation fault instead of returning the appropriate error message.
1505 ph10 134
1506 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1507 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1508     This doesn't seem right; it now treats the CRLF combination as the line
1509     ending, and so does not match in that case. It's only a pattern such as ^$
1510     that would hit this one: something like ^ABC$ would have failed after \r
1511     and then tried again after \r\n.
1513 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1514 ph10 134 in an attempt to make files that differ only in their line terminators
1515     compare equal. This works on Linux.
1516 ph10 142
1517 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1518     as it exited. This is now fixed, thanks to valgrind.
1519 ph10 142
1520 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1521 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1522     was because its rules for how to advance for /g after matching an empty
1523 ph10 143 string at the end of a line did not allow for this case. They now check for
1524     it specially.
1525 ph10 150
1526     20. pcretest is supposed to handle patterns and data of any length, by
1527     extending its buffers when necessary. It was getting this wrong when the
1528 ph10 147 buffer for a data line had to be extended.
1529 ph10 150
1530 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1531 ph10 150 CRLF as a newline sequence.
1532 ph10 152
1533 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1534 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1535     I have nevertheless tidied it up.
1536 ph10 111
1537 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1538 ph10 123
1539 ph10 153 24. Added a man page for pcre-config.
1540 ph10 152
1541 ph10 153
1542 nigel 93 Version 7.0 19-Dec-06
1543     ---------------------
1545     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1546     moving to gcc 4.1.1.
1548     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1549     sys/time.h, which is documented as needed for this function. It doesn't
1550     seem to matter on Linux, but it showed up on some releases of OS X.
1552     3. It seems that there are systems where bytes whose values are greater than
1553     127 match isprint() in the "C" locale. The "C" locale should be the
1554     default when a C program starts up. In most systems, only ASCII printing
1555     characters match isprint(). This difference caused the output from pcretest
1556     to vary, making some of the tests fail. I have changed pcretest so that:
1558     (a) When it is outputting text in the compiled version of a pattern, bytes
1559     other than 32-126 are always shown as hex escapes.
1561     (b) When it is outputting text that is a matched part of a subject string,
1562     it does the same, unless a different locale has been set for the match
1563     (using the /L modifier). In this case, it uses isprint() to decide.
1565     4. Fixed a major bug that caused incorrect computation of the amount of memory
1566     required for a compiled pattern when options that changed within the
1567     pattern affected the logic of the preliminary scan that determines the
1568     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1569     that the computed length was too small. The symptoms of this bug were
1570     either the PCRE error "internal error: code overflow" from pcre_compile(),
1571     or a glibc crash with a message such as "pcretest: free(): invalid next
1572     size (fast)". Examples of patterns that provoked this bug (shown in
1573     pcretest format) are:
1575     /(?-x: )/x
1576     /(?x)(?-x: \s*#\s*)/
1577     /((?i)[\x{c0}])/8
1578     /(?i:[\x{c0}])/8
1580     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1581     is now done differently.
1583     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1584     wrapper classes; (b) implement a new function in the C++ scanner that is
1585     more efficient than the old way of doing things because it avoids levels of
1586     recursion in the regex matching; (c) add a paragraph to the documentation
1587     for the FullMatch() function.
1589     6. The escape sequence \n was being treated as whatever was defined as
1590     "newline". Not only was this contrary to the documentation, which states
1591     that \n is character 10 (hex 0A), but it also went horribly wrong when
1592     "newline" was defined as CRLF. This has been fixed.
1594     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1595     was being set to -1 for the "end of line" case (supposedly a value that no
1596     character can have). Though this value is never used (the check for end of
1597     line is "zero bytes in current character"), it caused compiler complaints.
1598     I've changed it to 0xffffffff.
1600     8. In pcre_version.c, the version string was being built by a sequence of
1601     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1602     string (as it is for production releases) called a macro with an empty
1603     argument. The C standard says the result of this is undefined. The gcc
1604     compiler treats it as an empty string (which was what was wanted) but it is
1605     reported that Visual C gives an error. The source has been hacked around to
1606     avoid this problem.
1608     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1609     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1610     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1611     of them did).
1613     10. Originally, pcretest opened its input and output without "b"; then I was
1614     told that "b" was needed in some environments, so it was added for release
1615     5.0 to both the input and output. (It makes no difference on Unix-like
1616     systems.) Later I was told that it is wrong for the input on Windows. I've
1617     now abstracted the modes into two macros, to make it easier to fiddle with
1618     them, and removed "b" from the input mode under Windows.
1620     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1622     12. Added -help and --help to pcretest as an official way of being reminded
1623     of the options.
1625     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1626     and pcrecpp.cc because they annoy compilers at high warning levels.
1628     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1630     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1631     scripts are not C programs :-) and which was not noticed because it works
1632     on Linux.
1634     16. pcretest is supposed to handle any length of pattern and data line (as one
1635     line or as a continued sequence of lines) by extending its input buffer if
1636     necessary. This feature was broken for very long pattern lines, leading to
1637     a string of junk being passed to pcre_compile() if the pattern was longer
1638     than about 50K.
1640     17. I have done a major re-factoring of the way pcre_compile() computes the
1641     amount of memory needed for a compiled pattern. Previously, there was code
1642     that made a preliminary scan of the pattern in order to do this. That was
1643     OK when PCRE was new, but as the facilities have expanded, it has become
1644     harder and harder to keep it in step with the real compile phase, and there
1645     have been a number of bugs (see for example, 4 above). I have now found a
1646     cunning way of running the real compile function in a "fake" mode that
1647     enables it to compute how much memory it would need, while actually only
1648     ever using a few hundred bytes of working memory and without too many
1649     tests of the mode. This should make future maintenance and development
1650     easier. A side effect of this work is that the limit of 200 on the nesting
1651     depth of parentheses has been removed (though this was never a serious
1652     limitation, I suspect). However, there is a downside: pcre_compile() now
1653     runs more slowly than before (30% or more, depending on the pattern). I
1654     hope this isn't a big issue. There is no effect on runtime performance.
1656     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1657     newline (only possible for the last line of a file) and it was a
1658     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1660     19. Added additional timing features to pcretest. (1) The -tm option now times
1661     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1662     separate command line item, by a number that specifies the number of
1663     repeats to use when timing. The default is 50000; this gives better
1664     precision, but takes uncomfortably long for very large patterns.
1666     20. Extended pcre_study() to be more clever in cases where a branch of a
1667     subpattern has no definite first character. For example, (a*|b*)[cd] would
1668     previously give no result from pcre_study(). Now it recognizes that the
1669     first character must be a, b, c, or d.
1671     21. There was an incorrect error "recursive call could loop indefinitely" if
1672     a subpattern (or the entire pattern) that was being tested for matching an
1673     empty string contained only one non-empty item after a nested subpattern.
1674     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1675     incorrectly, because the \d was being skipped in the check.
1677     22. The pcretest program now has a new pattern option /B and a command line
1678     option -b, which is equivalent to adding /B to every pattern. This causes
1679     it to show the compiled bytecode, without the additional information that
1680     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1681     is the same as /B/I).
1683     23. A new optimization is now able automatically to treat some sequences such
1684     as a*b as a*+b. More specifically, if something simple (such as a character
1685     or a simple class like \d) has an unlimited quantifier, and is followed by
1686     something that cannot possibly match the quantified thing, the quantifier
1687     is automatically "possessified".
1689     24. A recursive reference to a subpattern whose number was greater than 39
1690     went wrong under certain circumstances in UTF-8 mode. This bug could also
1691     have affected the operation of pcre_study().
1693     25. Realized that a little bit of performance could be had by replacing
1694     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1696     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1698     27. Possessive quantifiers such as a++ were previously implemented by turning
1699     them into atomic groups such as ($>a+). Now they have their own opcodes,
1700     which improves performance. This includes the automatically created ones
1701     from 23 above.
1703     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1704     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1705     the first matched character to be a colon. This applied both to named and
1706     numbered groups.
1708     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1710     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1711     building PCRE on Windows easier, so I have included it in the distribution.
1713     31. There is now a check in pcretest against a ridiculously large number being
1714     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1715     loop, the loop is abandoned.
1717     32. Forward references to subpatterns in conditions such as (?(2)...) where
1718     subpattern 2 is defined later cause pcre_compile() to search forwards in
1719     the pattern for the relevant set of parentheses. This search went wrong
1720     when there were unescaped parentheses in a character class, parentheses
1721     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1723     33. "Subroutine" calls and backreferences were previously restricted to
1724     referencing subpatterns earlier in the regex. This restriction has now
1725     been removed.
1727     34. Added a number of extra features that are going to be in Perl 5.10. On the
1728     whole, these are just syntactic alternatives for features that PCRE had
1729     previously implemented using the Python syntax or my own invention. The
1730     other formats are all retained for compatibility.
1732     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1733     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1734     also .NET compatible.
1736     (b) A recursion or subroutine call to a named group can now be defined as
1737     (?&name) as well as (?P>name).
1739     (c) A backreference to a named group can now be defined as \k<name> or
1740     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1741     5.10, are also .NET compatible.
1743     (d) A conditional reference to a named group can now use the syntax
1744     (?(<name>) or (?('name') as well as (?(name).
1746     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1747     groups (named and numbered) that are never evaluated inline, but can be
1748     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1749     is always false. There may be only one alternative in such a group.
1751     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1752     as the simple (?(R). The condition is true only if the most recent
1753     recursion is that of the given number or name. It does not search out
1754     through the entire recursion stack.
1756     (g) The escape \gN or \g{N} has been added, where N is a positive or
1757     negative number, specifying an absolute or relative reference.
1759     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1760     some "unreachable code" warnings.
1762     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1763     things, this adds five new scripts.
1765     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1766     There were also incompatibilities regarding the handling of \Q..\E inside
1767     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1768     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1770     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1771     matches an empty string, and forcibly breaks the loop. There were bugs in
1772     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1773     against aaaa the result was just "a" rather than "aaaa", for example. Two
1774     separate and independent bugs (that affected different cases) have been
1775     fixed.
1777     39. Refactored the code to abolish the use of different opcodes for small
1778     capturing bracket numbers. This is a tidy that I avoided doing when I
1779     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1780     The new approach is not only tidier, it makes it possible to reduce the
1781     memory needed to fix the previous bug (38).
1783     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1784     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1785     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1786     mode.
1788     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1789     report.
1791     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1792     copy construction and assignment in the C++ wrapper.
1794     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1795     couple of bugs that could have given wrong results in the "--newline=crlf"
1796     case.
1798     44. Added a number of casts and did some reorganization of signed/unsigned int
1799     variables following suggestions from Dair Grant. Also renamed the variable
1800     "this" as "item" because it is a C++ keyword.
1802     45. Arranged for dftables to add
1804     #include "pcre_internal.h"
1806     to pcre_chartables.c because without it, gcc 4.x may remove the array
1807     definition from the final binary if PCRE is built into a static library and
1808     dead code stripping is activated.
1810     46. For an unanchored pattern, if a match attempt fails at the start of a
1811     newline sequence, and the newline setting is CRLF or ANY, and the next two
1812     characters are CRLF, advance by two characters instead of one.
1815 nigel 91 Version 6.7 04-Jul-06
1816     ---------------------
1818     1. In order to handle tests when input lines are enormously long, pcretest has
1819     been re-factored so that it automatically extends its buffers when
1820     necessary. The code is crude, but this _is_ just a test program. The
1821     default size has been increased from 32K to 50K.
1823     2. The code in pcre_study() was using the value of the re argument before
1824     testing it for NULL. (Of course, in any sensible call of the function, it
1825     won't be NULL.)
1827     3. The memmove() emulation function in pcre_internal.h, which is used on
1828     systems that lack both memmove() and bcopy() - that is, hardly ever -
1829     was missing a "static" storage class specifier.
1831     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1832     containing an extended class (one that cannot be represented by a bitmap
1833     because it contains high-valued characters or Unicode property items, e.g.
1834     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1835     pattern, but PCRE should not loop if you do not (it no longer does).
1836     [Detail: two cases were found: (a) a repeated subpattern containing an
1837     extended class; (b) a recursive reference to a subpattern that followed a
1838     previous extended class. It wasn't skipping over the extended class
1839     correctly when UTF-8 mode was not set.]
1841     5. A negated single-character class was not being recognized as fixed-length
1842     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1843     compile error "lookbehind assertion is not fixed length".
1845     6. The RunPerlTest auxiliary script was showing an unexpected difference
1846     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1847     write a Perl script that can interpret lines of an input file either as
1848     byte characters or as UTF-8, which is what "perltest" was being required to
1849     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1850     can't do is switch easily at run time between having the "use utf8;" pragma
1851     or not. In the end, I fudged it by using the RunPerlTest script to insert
1852     "use utf8;" explicitly for the UTF-8 tests.
1854     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1855     the end of the subject string, contrary to the documentation and to what
1856     Perl does. This was true of both matching functions. Now it matches only at
1857     the start of the subject and immediately after *internal* newlines.
1859     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1860     a pointer to an int instead of a pointer to an unsigned long int. This
1861     caused problems on 64-bit systems.
1863     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1864     instance of the 'standard' template library not being so standard".
1866     10. There was no check on the number of named subpatterns nor the maximum
1867     length of a subpattern name. The product of these values is used to compute
1868     the size of the memory block for a compiled pattern. By supplying a very
1869     long subpattern name and a large number of named subpatterns, the size
1870     computation could be caused to overflow. This is now prevented by limiting
1871     the length of names to 32 characters, and the number of named subpatterns
1872     to 10,000.
1874     11. Subpatterns that are repeated with specific counts have to be replicated in
1875     the compiled pattern. The size of memory for this was computed from the
1876     length of the subpattern and the repeat count. The latter is limited to
1877     65535, but there was no limit on the former, meaning that integer overflow
1878     could in principle occur. The compiled length of a repeated subpattern is
1879     now limited to 30,000 bytes in order to prevent this.
1881     12. Added the optional facility to have named substrings with the same name.
1883     13. Added the ability to use a named substring as a condition, using the
1884     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1885     are numbers (not recommended). Forward references are permitted.
1887     14. Added forward references in named backreferences (if you see what I mean).
1889     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1890     pattern could run off the end of the subject. For example, the pattern
1891     "(?s)(.{1,5})"8 did this with the subject "ab".
1893     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1894     PCRE_CASELESS was set when matching characters that were quantified with ?
1895     or *.
1897     17. A character class other than a single negated character that had a minimum
1898     but no maximum quantifier - for example [ab]{6,} - was not handled
1899     correctly by pce_dfa_exec(). It would match only one character.
1901     18. A valid (though odd) pattern that looked like a POSIX character
1902     class but used an invalid character after [ (for example [[,abc,]]) caused
1903     pcre_compile() to give the error "Failed: internal error: code overflow" or
1904     in some cases to crash with a glibc free() error. This could even happen if
1905     the pattern terminated after [[ but there just happened to be a sequence of
1906     letters, a binary zero, and a closing ] in the memory that followed.
1908     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1909     over the years. Originally (before any Unicode support), just the bottom 8
1910     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1911     output from "man perlunicode" includes this:
1913     The regular expression compiler produces polymorphic opcodes. That
1914     is, the pattern adapts to the data and automatically switches to
1915     the Unicode character scheme when presented with Unicode data--or
1916     instead uses a traditional byte scheme when presented with byte
1917     data.
1919     Sadly, a wide octal escape does not cause a switch, and in a string with
1920     no other multibyte characters, these octal escapes are treated as before.
1921     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1922     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1923     Unicode string.
1925     I have not perpetrated such confusion in PCRE. Up till now, it took just
1926     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1927     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1928     translate to the appropriate multibyte character.
1930     29. Applied some refactoring to reduce the number of warnings from Microsoft
1931     and Borland compilers. This has included removing the fudge introduced
1932     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1933     a warning about an unused variable.
1935     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1936     characters since release 4.0, because Perl (from release 5.004) does not.
1937     [Or at least, is documented not to: some releases seem to be in conflict
1938     with the documentation.] However, when a pattern was studied with
1939     pcre_study() and all its branches started with \s, PCRE still included VT
1940     as a possible starting character. Of course, this did no harm; it just
1941     caused an unnecessary match attempt.
1943     22. Removed a now-redundant internal flag bit that recorded the fact that case
1944     dependency changed within the pattern. This was once needed for "required
1945     byte" processing, but is no longer used. This recovers a now-scarce options
1946     bit. Also moved the least significant internal flag bit to the most-
1947     significant bit of the word, which was not previously used (hangover from
1948     the days when it was an int rather than a uint) to free up another bit for
1949     the future.
1951     23. Added support for CRLF line endings as well as CR and LF. As well as the
1952     default being selectable at build time, it can now be changed at runtime
1953     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1954     specify that it is scanning data with non-default line endings.
1956     24. Changed the definition of CXXLINK to make it agree with the definition of
1957     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1959     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1960     recursions. This makes a big different to stack usage for some patterns.
1962     26. If a subpattern containing a named recursion or subroutine reference such
1963     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1964     the space required for the compiled pattern went wrong and gave too small a
1965     value. Depending on the environment, this could lead to "Failed: internal
1966     error: code overflow at offset 49" or "glibc detected double free or
1967     corruption" errors.
1969     27. Applied patches from Google (a) to support the new newline modes and (b) to
1970     advance over multibyte UTF-8 characters in GlobalReplace.
1972     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1973     difference for some implementation of PCRE in some Windows version.
1975     29. Added some extra testing facilities to pcretest:
1977     \q<number> in a data line sets the "match limit" value
1978     \Q<number> in a data line sets the "match recursion limt" value
1979     -S <number> sets the stack size, where <number> is in megabytes
1981     The -S option isn't available for Windows.
1984 nigel 89 Version 6.6 06-Feb-06
1985     ---------------------
1987     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1988     in pcreposix.h. I have copied the definition from pcre.h.
1990     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1991     because pcre.h is no longer a built file.
1993     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1994     not normally included in the compiled code.
1997 nigel 87 Version 6.5 01-Feb-06
1998     ---------------------
2000     1. When using the partial match feature with pcre_dfa_exec(), it was not
2001     anchoring the second and subsequent partial matches at the new starting
2002     point. This could lead to incorrect results. For example, with the pattern
2003     /1234/, partially matching against "123" and then "a4" gave a match.
2005     2. Changes to pcregrep:
2007     (a) All non-match returns from pcre_exec() were being treated as failures
2008     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2009     error message is output. Some extra information is given for the
2011     probably the only errors that are likely to be caused by users (by
2012     specifying a regex that has nested indefinite repeats, for instance).
2013     If there are more than 20 of these errors, pcregrep is abandoned.
2015     (b) A binary zero was treated as data while matching, but terminated the
2016     output line if it was written out. This has been fixed: binary zeroes
2017     are now no different to any other data bytes.
2019     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2020     used to set a locale for matching. The --locale=xxxx long option has
2021     been added (no short equivalent) to specify a locale explicitly on the
2022     pcregrep command, overriding the environment variables.
2024     (d) When -B was used with -n, some line numbers in the output were one less
2025     than they should have been.
2027     (e) Added the -o (--only-matching) option.
2029     (f) If -A or -C was used with -c (count only), some lines of context were
2030     accidentally printed for the final match.
2032     (g) Added the -H (--with-filename) option.
2034     (h) The combination of options -rh failed to suppress file names for files
2035     that were found from directory arguments.
2037     (i) Added the -D (--devices) and -d (--directories) options.
2039     (j) Added the -F (--fixed-strings) option.
2041     (k) Allow "-" to be used as a file name for -f as well as for a data file.
2043     (l) Added the --colo(u)r option.
2045     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2046     is not present by default.
2048     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2049     items such as (?R) or (?1), when the recursion could match a number of
2050     alternatives. If it matched one of the alternatives, but subsequently,
2051     outside the recursion, there was a failure, the code tried to back up into
2052     the recursion. However, because of the way PCRE is implemented, this is not
2053     possible, and the result was an incorrect result from the match.
2055     In order to prevent this happening, the specification of recursion has
2056     been changed so that all such subpatterns are automatically treated as
2057     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2059     4. I had overlooked the fact that, in some locales, there are characters for
2060     which isalpha() is true but neither isupper() nor islower() are true. In
2061     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2062     and ordfeminine) are like this. This affected the treatment of \w and \W
2063     when they appeared in character classes, but not when they appeared outside
2064     a character class. The bit map for "word" characters is now created
2065     separately from the results of isalnum() instead of just taking it from the
2066     upper, lower, and digit maps. (Plus the underscore character, of course.)
2068     5. The above bug also affected the handling of POSIX character classes such as
2069     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2070     permanent tables. Instead, the bit maps for such a class were previously
2071     created as the appropriate unions of the upper, lower, and digit bitmaps.
2072     Now they are created by subtraction from the [[:word:]] class, which has
2073     its own bitmap.
2075     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2076     It is created by subtracting the vertical space characters (\x09, \x0a,
2077     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2078     subtraction was done in the overall bitmap for a character class, meaning
2079     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2080     be recognized. This bug has been fixed.
2082     7. Patches from the folks at Google:
2084     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2085     real life, but is still worth protecting against".
2087     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2088     regular expressions".
2090     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2091     have it.
2093     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2094     "configure" and the latter not, in order to fix a problem somebody had
2095     with compiling the Arg class on HP-UX.
2097     (e) Improve the error-handling of the C++ wrapper a little bit.
2099     (f) New tests for checking recursion limiting.
2101     8. The pcre_memmove() function, which is used only if the environment does not
2102     have a standard memmove() function (and is therefore rarely compiled),
2103     contained two bugs: (a) use of int instead of size_t, and (b) it was not
2104     returning a result (though PCRE never actually uses the result).
2106     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2107     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2108     returned instead of calling malloc() with an overflowing number that would
2109     most likely cause subsequent chaos.
2111     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2113     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2114     with this option is matched, the nmatch and pmatch options of regexec() are
2115     ignored.
2117     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2118     provided in case anyone wants to the the POSIX interface with UTF-8
2119     strings.
2121     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2122     C++ linking (needed for some HP-UX environments).
2124     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2125     (unused parameter) and in the pcre_printint() function (omitted "default"
2126     switch label when the default is to do nothing).
2128     15. Added some code to make it possible, when PCRE is compiled as a C++
2129     library, to replace subject pointers for pcre_exec() with a smart pointer
2130     class, thus making it possible to process discontinuous strings.
2132     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2133     much the same function. They were added by different people who were trying
2134     to make PCRE easy to compile on non-Unix systems. It has been suggested
2135     that PCRE_EXPORT be abolished now that there is more automatic apparatus
2136     for compiling on Windows systems. I have therefore replaced it with
2137     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2138     defaults to "extern" for C or "extern C" for C++, which works fine on
2139     Unix-like systems. It is now possible to override the value of PCRE_DATA_
2140     SCOPE with something explicit in config.h. In addition:
2142     (a) pcreposix.h still had just "extern" instead of either of these macros;
2143     I have replaced it with PCRE_DATA_SCOPE.
2145     (b) Functions such as _pcre_xclass(), which are internal to the library,
2146     but external in the C sense, all had PCRE_EXPORT in their definitions.
2147     This is apparently wrong for the Windows case, so I have removed it.
2148     (It makes no difference on Unix-like systems.)
2150     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2151     of recursive calls to match(). This is different to MATCH_LIMIT because
2152     that limits the total number of calls to match(), not all of which increase
2153     the depth of recursion. Limiting the recursion depth limits the amount of
2154     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2155     when PCRE is compiled, and changed at run time. A patch from Google adds
2156     this functionality to the C++ interface.
2158     18. Changes to the handling of Unicode character properties:
2160     (a) Updated the table to Unicode 4.1.0.
2162     (b) Recognize characters that are not in the table as "Cn" (undefined).
2164     (c) I revised the way the table is implemented to a much improved format
2165     which includes recognition of ranges. It now supports the ranges that
2166     are defined in UnicodeData.txt, and it also amalgamates other
2167     characters into ranges. This has reduced the number of entries in the
2168     table from around 16,000 to around 3,000, thus reducing its size
2169     considerably. I realized I did not need to use a tree structure after
2170     all - a binary chop search is just as efficient. Having reduced the
2171     number of entries, I extended their size from 6 bytes to 8 bytes to
2172     allow for more data.
2174     (d) Added support for Unicode script names via properties such as \p{Han}.
2176     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2177     matching that character.
2179     20. When matching a repeated Unicode property with a minimum greater than zero,
2180     (for example \pL{2,}), PCRE could look past the end of the subject if it
2181     reached it while seeking the minimum number of characters. This could
2182     happen only if some of the characters were more than one byte long, because
2183     there is a check for at least the minimum number of bytes.
2185     21. Refactored the implementation of \p and \P so as to be more general, to
2186     allow for more different types of property in future. This has changed the
2187     compiled form incompatibly. Anybody with saved compiled patterns that use
2188     \p or \P will have to recompile them.
2190     22. Added "Any" and "L&" to the supported property types.
2192     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2193     but give a compile time error if the value is greater than 0xff.
2195     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2196     accidentally not being installed or uninstalled.
2198     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2199     made were to insert the current release number. This seemed silly, because
2200     it made things harder for people building PCRE on systems that don't run
2201     "configure". I have turned pcre.h into a distributed file, no longer built
2202     by "configure", with the version identification directly included. There is
2203     no longer a pcre.h.in file.
2205     However, this change necessitated a change to the pcre-config script as
2206     well. It is built from pcre-config.in, and one of the substitutions was the
2207     release number. I have updated configure.ac so that ./configure now finds
2208     the release number by grepping pcre.h.
2210     26. Added the ability to run the tests under valgrind.
2213 nigel 85 Version 6.4 05-Sep-05
2214     ---------------------
2216     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2217     "--" to be printed when multiple files were scanned, even when none of the
2218     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2219     consider it to be a bug, and have restored the previous behaviour.
2221     2. A couple of code tidies to get rid of compiler warnings.
2223     3. The pcretest program used to cheat by referring to symbols in the library
2224     whose names begin with _pcre_. These are internal symbols that are not
2225     really supposed to be visible externally, and in some environments it is
2226     possible to suppress them. The cheating is now confined to including
2227     certain files from the library's source, which is a bit cleaner.
2229     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2230     file's purpose clearer.
2232     5. Reorganized pcre_ucp_findchar().
2235 nigel 83 Version 6.3 15-Aug-05
2236     ---------------------
2238     1. The file libpcre.pc.in did not have general read permission in the tarball.
2240     2. There were some problems when building without C++ support:
2242     (a) If C++ support was not built, "make install" and "make test" still
2243     tried to test it.
2245     (b) There were problems when the value of CXX was explicitly set. Some
2246     changes have been made to try to fix these, and ...
2248     (c) --disable-cpp can now be used to explicitly disable C++ support.
2250     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2251     backslash in a target when C++ was disabled. This confuses some
2252     versions of "make", apparently. Using an intermediate variable solves
2253     this. (Same for CPP_LOBJ.)
2255     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2256     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2257     necessary on certain architectures.
2259     4. Added a setting of -export-symbols-regex to the link command to remove
2260     those symbols that are exported in the C sense, but actually are local
2261     within the library, and not documented. Their names all begin with
2262     "_pcre_". This is not a perfect job, because (a) we have to except some
2263     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2264     available (and never for static libraries). I have made a note to try to
2265     find a way round (a) in the future.
2268 nigel 81 Version 6.2 01-Aug-05
2269     ---------------------
2271     1. There was no test for integer overflow of quantifier values. A construction
2272     such as {1111111111111111} would give undefined results. What is worse, if
2273     a minimum quantifier for a parenthesized subpattern overflowed and became
2274     negative, the calculation of the memory size went wrong. This could have
2275     led to memory overwriting.
2277     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2279     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2280     operating environments where this matters.
2282     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2283     PCRE options from within the C++ wrapper.
2285     5. Named capturing subpatterns were not being correctly counted when a pattern
2286     was compiled. This caused two problems: (a) If there were more than 100
2287     such subpatterns, the calculation of the memory needed for the whole
2288     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2289     back references of the form \12, where the number was greater than 9, were
2290     not recognized as back references, even though there were sufficient
2291     previous subpatterns.
2293     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2294     versions of gcc, e.g. 2.95.4.
2297 nigel 79 Version 6.1 21-Jun-05
2298     ---------------------
2300     1. There was one reference to the variable "posix" in pcretest.c that was not
2301     surrounded by "#if !defined NOPOSIX".
2303     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2304     the cross-check on the old pcre_info() function, for the benefit of the
2305     cut-down version of PCRE that is currently imported into Exim.
2307     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2308     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2309     patterns that start (?i) but I don't think that matters. The use of (?i) is
2310     just an example; this all applies to the other options as well.
2312     4. Since libtool seems to echo the compile commands it is issuing, the output
2313     from "make" can be reduced a bit by putting "@" in front of each libtool
2314     compile command.
2316     5. Patch from the folks at Google for configure.in to be a bit more thorough
2317     in checking for a suitable C++ installation before trying to compile the
2318     C++ stuff. This should fix a reported problem when a compiler was present,
2319     but no suitable headers.
2321     6. The man pages all had just "PCRE" as their title. I have changed them to
2322     be the relevant file name. I have also arranged that these names are
2323     retained in the file doc/pcre.txt, which is a concatenation in text format
2324     of all the man pages except the little individual ones for each function.
2326     7. The NON-UNIX-USE file had not been updated for the different set of source
2327     files that come with release 6. I also added a few comments about the C++
2328     wrapper.
2331 nigel 77 Version 6.0 07-Jun-05
2332     ---------------------
2334     1. Some minor internal re-organization to help with my DFA experiments.
2336     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2337     didn't matter for the library itself when fully configured, but did matter
2338     when compiling without UCP support, or within Exim, where the ucp files are
2339     not imported.
2341     3. Refactoring of the library code to split up the various functions into
2342     different source modules. The addition of the new DFA matching code (see
2343     below) to a single monolithic source would have made it really too
2344     unwieldy, quite apart from causing all the code to be include in a
2345     statically linked application, when only some functions are used. This is
2346     relevant even without the DFA addition now that patterns can be compiled in
2347     one application and matched in another.
2349     The downside of splitting up is that there have to be some external
2350     functions and data tables that are used internally in different modules of
2351     the library but which are not part of the API. These have all had their
2352     names changed to start with "_pcre_" so that they are unlikely to clash
2353     with other external names.
2355     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2356     a different (DFA) algorithm. Although it is slower than the original
2357     function, it does have some advantages for certain types of matching
2358     problem.
2360     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2361     including restarting after a partial match.
2363     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2364     defined when compiling for Windows was sent to me. I have put it into the
2365     code, though I have no means of testing or verifying it.
2367     7. Added the pcre_refcount() auxiliary function.
2369     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2370     match before or at the first newline in the subject string. In pcretest,
2371     the /f option on a pattern can be used to set this.
2373     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2374     would behave wrongly. This has been present in PCRE since release 4.0.
2376     10. A number of changes to the pcregrep command:
2378     (a) Refactored how -x works; insert ^(...)$ instead of setting
2379     PCRE_ANCHORED and checking the length, in preparation for adding
2380     something similar for -w.
2382     (b) Added the -w (match as a word) option.
2384     (c) Refactored the way lines are read and buffered so as to have more
2385     than one at a time available.
2387     (d) Implemented a pcregrep test script.
2389     (e) Added the -M (multiline match) option. This allows patterns to match
2390     over several lines of the subject. The buffering ensures that at least
2391     8K, or the rest of the document (whichever is the shorter) is available
2392     for matching (and similarly the previous 8K for lookbehind assertions).
2394     (f) Changed the --help output so that it now says
2396     -w, --word-regex(p)
2398     instead of two lines, one with "regex" and the other with "regexp"
2399     because that confused at least one person since the short forms are the
2400     same. (This required a bit of code, as the output is generated
2401     automatically from a table. It wasn't just a text change.)
2403     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2404     option but starts with a hyphen. Could be a pattern or a path name
2405     starting with a hyphen, for instance.
2407     (h) "-" can be given as a file name to represent stdin.
2409     (i) When file names are being printed, "(standard input)" is used for
2410     the standard input, for compatibility with GNU grep. Previously
2411     "<stdin>" was used.
2413     (j) The option --label=xxx can be used to supply a name to be used for
2414     stdin when file names are being printed. There is no short form.
2416     (k) Re-factored the options decoding logic because we are going to add
2417     two more options that take data. Such options can now be given in four
2418     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2420     (l) Added the -A, -B, and -C options for requesting that lines of context
2421     around matches be printed.
2423     (m) Added the -L option to print the names of files that do not contain
2424     any matching lines, that is, the complement of -l.
2426     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2427     continue to scan other files.
2429     (o) The -s option was incorrectly implemented. For compatibility with other
2430     greps, it now suppresses the error message for a non-existent or non-
2431     accessible file (but not the return code). There is a new option called
2432     -q that suppresses the output of matching lines, which was what -s was
2433     previously doing.
2435     (p) Added --include and --exclude options to specify files for inclusion
2436     and exclusion when recursing.
2438     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2439     Hopefully, it now does.
2441     12. Missing cast in pcre_study().
2443     13. Added an "uninstall" target to the makefile.
2445     14. Replaced "extern" in the function prototypes in Makefile.in with
2446     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2447     world, but is set differently for Windows.
2449     15. Added a second compiling function called pcre_compile2(). The only
2450     difference is that it has an extra argument, which is a pointer to an
2451     integer error code. When there is a compile-time failure, this is set
2452     non-zero, in addition to the error test pointer being set to point to an
2453     error message. The new argument may be NULL if no error number is required
2454     (but then you may as well call pcre_compile(), which is now just a
2455     wrapper). This facility is provided because some applications need a
2456     numeric error indication, but it has also enabled me to tidy up the way
2457     compile-time errors are handled in the POSIX wrapper.
2459     16. Added VPATH=.libs to the makefile; this should help when building with one
2460     prefix path and installing with another. (Or so I'm told by someone who
2461     knows more about this stuff than I do.)
2463     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2464     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2465     match everything, including newlines. This is not POSIX-compatible, but
2466     somebody wanted the feature. From pcretest it can be activated by using
2467     both the P and the s flags.
2469     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2471     19. libpcre.pc was being incorrectly installed as executable.
2473     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2474     it now also looks for '\r' so that it will work unmodified on Windows.
2476     21. Added Google's contributed C++ wrapper to the distribution.
2478     22. Added some untidy missing memory free() calls in pcretest, to keep
2479     Electric Fence happy when testing.
2483 nigel 75 Version 5.0 13-Sep-04
2484     ---------------------
2486     1. Internal change: literal characters are no longer packed up into items
2487     containing multiple characters in a single byte-string. Each character
2488     is now matched using a separate opcode. However, there may be more than one
2489     byte in the character in UTF-8 mode.
2491     2. The pcre_callout_block structure has two new fields: pattern_position and
2492     next_item_length. These contain the offset in the pattern to the next match
2493     item, and its length, respectively.
2495     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2496     insertion of callouts before each pattern item. Added the /C option to
2497     pcretest to make use of this.
2499     4. On the advice of a Windows user, the lines
2501     #if defined(_WIN32) || defined(WIN32)
2502     _setmode( _fileno( stdout ), 0x8000 );
2503     #endif /* defined(_WIN32) || defined(WIN32) */
2505     have been added to the source of pcretest. This apparently does useful
2506     magic in relation to line terminators.
2508     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2509     for the benefit of those environments where the "b" makes a difference.
2511     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2512     to know about it. I have put a hack into configure.in that adds in code
2513     to set GCC=yes if CC=icc. This seems to end up at a point in the
2514     generated configure script that is early enough to affect the setting of
2515     compiler options, which is what is needed, but I have no means of testing
2516     whether it really works. (The user who reported this had patched the
2517     generated configure script, which of course I cannot do.)
2519     LATER: After change 22 below (new libtool files), the configure script
2520     seems to know about icc (and also ecc). Therefore, I have commented out
2521     this hack in configure.in.
2523     7. Added support for pkg-config (2 patches were sent in).
2525     8. Negated POSIX character classes that used a combination of internal tables
2526     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2527     [[:^ascii]]. Typically, they would match almost any characters. The other
2528     POSIX classes were not broken in this way.
2530     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2531     to find the match, as PCRE was deluded into thinking that the match had to
2532     start at the start point or following a newline. The same bug applied to
2533     patterns with negative forward assertions or any backward assertions
2534     preceding ".*" at the start, unless the pattern required a fixed first
2535     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2537     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2538     starting at the last subject character, bytes beyond the end of the subject
2539     string were read.
2541     11. Renamed the variable "class" as "classbits" to make life easier for C++
2542     users. (Previously there was a macro definition, but it apparently wasn't
2543     enough.)
2545     12. Added the new field "tables" to the extra data so that tables can be passed
2546     in at exec time, or the internal tables can be re-selected. This allows
2547     a compiled regex to be saved and re-used at a later time by a different
2548     program that might have everything at different addresses.
2550     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2551     -R library as well as a -L library.
2553     14. The debugging options of pcretest (-d on the command line or D on a
2554     pattern) showed incorrect output for anything following an extended class
2555     that contained multibyte characters and which was followed by a quantifier.
2557     15. Added optional support for general category Unicode character properties
2558     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2559     support. It adds about 90K to the size of the library. The meanings of the
2560     inbuilt class escapes such as \d and \s have NOT been changed.
2562     16. Updated pcredemo.c to include calls to free() to release the memory for the
2563     compiled pattern.
2565     17. The generated file chartables.c was being created in the source directory
2566     instead of in the building directory. This caused the build to fail if the
2567     source directory was different from the building directory, and was
2568     read-only.
2570     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2571     file. No doubt somebody will tell me if they don't make sense... Also added
2572     Dan Mooney's comments about building on OpenVMS.
2574     19. Added support for partial matching via the PCRE_PARTIAL option for
2575     pcre_exec() and the \P data escape in pcretest.
2577     20. Extended pcretest with 3 new pattern features:
2579     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2580     write the compiled pattern to the file whose name is "rest-of-line".
2581     This is a straight binary dump of the data, with the saved pointer to
2582     the character tables forced to be NULL. The study data, if any, is
2583     written too. After writing, pcretest reads a new pattern.
2585     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2586     compiled pattern from the given file. There must not be any
2587     occurrences of "<" in the file name (pretty unlikely); if there are,
2588     pcretest will instead treat the initial "<" as a pattern delimiter.
2589     After reading in the pattern, pcretest goes on to read data lines as
2590     usual.
2592     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2593     and 16-bit fields in a compiled pattern, to simulate a pattern that
2594     was compiled on a host of opposite endianness.
2596     21. The pcre-exec() function can now cope with patterns that were compiled on
2597     hosts of opposite endianness, with this restriction:
2599     As for any compiled expression that is saved and used later, the tables
2600     pointer field cannot be preserved; the extra_data field in the arguments
2601     to pcre_exec() should be used to pass in a tables address if a value
2602     other than the default internal tables were used at compile time.
2604     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2605     now diagnosed as an error. Previously, most of the time, a negative number
2606     would have been treated as zero, but if in addition "ovector" was passed as
2607     NULL, a crash could occur.
2609     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2610     new versions from the libtool 1.5 distribution (the last one is a copy of
2611     a file called libtool.m4). This seems to have fixed the need to patch
2612     "configure" to support Darwin 1.3 (which I used to do). However, I still
2613     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2614     workstation).
2616     24. Changed the PCRE licence to be the more standard "BSD" licence.
2619 nigel 73 Version 4.5 01-Dec-03
2620     ---------------------
2622     1. There has been some re-arrangement of the code for the match() function so
2623     that it can be compiled in a version that does not call itself recursively.
2624     Instead, it keeps those local variables that need separate instances for
2625     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2626     needs to "recurse". Keeping track of where control must go is done by means
2627     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2628     hide most of the details from the main code, and operates only if
2629     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2630     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2631     operating.
2633     To make it easier for callers to provide specially tailored get/free
2634     functions for this usage, two new functions, pcre_stack_malloc, and
2635     pcre_stack_free, are used. They are always called in strict stacking order,
2636     and the size of block requested is always the same.
2638     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2639     PCRE has been compiled to use the stack or the heap for recursion. The
2640     -C option of pcretest uses this to show which version is compiled.
2642     A new data escape \S, is added to pcretest; it causes the amounts of store
2643     obtained and freed by both kinds of malloc/free at match time to be added
2644     to the output.
2646     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2647     what's available on my current Linux desktop machine.
2649     3. When matching a UTF-8 string, the test for a valid string at the start has
2650     been extended. If start_offset is not zero, PCRE now checks that it points
2651     to a byte that is the start of a UTF-8 character. If not, it returns
2652     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2653     this is necessary because there may be backward assertions in the pattern.
2654     When matching the same subject several times, it may save resources to use
2655     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2657     4. The code for checking the validity of UTF-8 strings has been tightened so
2658     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2659     containing "overlong sequences".
2661     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2662     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2663     should have been "&", but it just so happened that all the cases this let
2664     through by mistake were picked up later in the function.
2666     6. I had used a variable called "isblank" - this is a C99 function, causing
2667     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2669     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2670     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2671     so the version is shown; (c) stop "make test" echoing "./RunTest".
2673     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2675     9. The prototype for memmove() for systems that don't have it was using
2676     size_t, but the inclusion of the header that defines size_t was later. I've
2677     moved the #includes for the C headers earlier to avoid this.
2679     10. Added some adjustments to the code to make it easier to compiler on certain
2680     special systems:
2682     (a) Some "const" qualifiers were missing.
2683     (b) Added the macro EXPORT before all exported functions; by default this
2684     is defined to be empty.
2685     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2686     that it reads its output file name as an argument instead of writing
2687     to the standard output and assuming this can be redirected.
2689     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2690     class containing characters with values greater than 255, PCRE compilation
2691     went into a loop.
2693     12. A recursive reference to a subpattern that was within another subpattern
2694     that had a minimum quantifier of zero caused PCRE to crash. For example,
2695     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2696     recursion. If the recursively-called subpattern itself had a zero repeat,
2697     that was OK.
2699     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2700     buffer into which it was copied (for escape processing) was still set at
2701     1024, so long lines caused crashes.
2703     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2704     "internal error: code overflow...". This applied to any character class
2705     that was followed by a possessive quantifier.
2707     15. Modified the Makefile to add libpcre.la as a prerequisite for
2708     libpcreposix.la because I was told this is needed for a parallel build to
2709     work.
2711     16. If a pattern that contained .* following optional items at the start was
2712     studied, the wrong optimizing data was generated, leading to matching
2713     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2714     matching string must start with a or b or c. The correct conclusion for
2715     this pattern is that a match can start with any character.
2718 nigel 71 Version 4.4 13-Aug-03
2719     ---------------------
2721     1. In UTF-8 mode, a character class containing characters with values between
2722     127 and 255 was not handled correctly if the compiled pattern was studied.
2723     In fixing this, I have also improved the studying algorithm for such
2724     classes (slightly).
2726     2. Three internal functions had redundant arguments passed to them. Removal
2727     might give a very teeny performance improvement.
2729     3. Documentation bug: the value of the capture_top field in a callout is *one
2730     more than* the number of the hightest numbered captured substring.
2732     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2733     in incorrectly linking with a previously installed version. They now link
2734     explicitly with libpcre.la.
2736     5. configure.in no longer needs to recognize Cygwin specially.
2738     6. A problem in pcre.in for Windows platforms is fixed.
2740     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2741     pcretest, it used to include the size of the study block as part of its
2742     output. Unfortunately, the structure contains a field that has a different
2743     size on different hardware architectures. This meant that the tests that
2744     showed this size failed. As the block is currently always of a fixed size,
2745     this information isn't actually particularly useful in pcretest output, so
2746     I have just removed it.
2748     8. Three pre-processor statements accidentally did not start in column 1.
2749     Sadly, there are *still* compilers around that complain, even though
2750     standard C has not required this for well over a decade. Sigh.
2752     9. In pcretest, the code for checking callouts passed small integers in the
2753     callout_data field, which is a void * field. However, some picky compilers
2754     complained about the casts involved for this on 64-bit systems. Now
2755     pcretest passes the address of the small integer instead, which should get
2756     rid of the warnings.
2758     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2759     both compile and run time, and gives an error if an invalid UTF-8 sequence
2760     is found. There is a option for disabling this check in cases where the
2761     string is known to be correct and/or the maximum performance is wanted.
2763     11. In response to a bug report, I changed one line in Makefile.in from
2765     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2766     to
2767     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2769     to look similar to other lines, but I have no way of telling whether this
2770     is the right thing to do, as I do not use Windows. No doubt I'll get told
2771     if it's wrong...
2774 nigel 69 Version 4.3 21-May-03
2775     ---------------------
2777     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2778     Makefile.
2780     2. Some refactoring to improve the quality of the code:
2782     (i) The utf8_table... variables are now declared "const".
2784     (ii) The code for \cx, which used the "case flipping" table to upper case
2785     lower case letters, now just substracts 32. This is ASCII-specific,
2786     but the whole concept of \cx is ASCII-specific, so it seems
2787     reasonable.
2789     (iii) PCRE was using its character types table to recognize decimal and
2790     hexadecimal digits in the pattern. This is silly, because it handles
2791     only 0-9, a-f, and A-F, but the character types table is locale-
2792     specific, which means strange things might happen. A private
2793     table is now used for this - though it costs 256 bytes, a table is
2794     much faster than multiple explicit tests. Of course, the standard
2795     character types table is still used for matching digits in subject
2796     strings against \d.
2798     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2799     ending in _t are). So I've renamed it as ESC_tee.
2801     3. The first argument for regexec() in the POSIX wrapper should have been
2802     defined as "const".
2804     4. Changed pcretest to use malloc() for its buffers so that they can be
2805     Electric Fenced for debugging.
2807     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2808     to read one or more bytes before the start of the subject string. Often this
2809     had no effect on PCRE's behaviour, but in some circumstances it could
2810     provoke a segmentation fault.
2812     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2813     to try to read one or more bytes before the start of the subject string.
2815     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2816     UTF-8 support could misbehave in various ways if the subject string
2817     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2818     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2819     back over UTF-8 characters.)
2822 nigel 67 Version 4.2 14-Apr-03
2823     ---------------------
2825     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2827     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2828     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2829     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2830     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2831     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2832     and BUILD_EXEEXT
2833     Note: automatic setting of the BUILD variables is not yet working
2834     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2835     compile-time but not at link-time
2836     [LINK]: use for linking executables only
2837     make different versions for Windows and non-Windows
2838     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2839     libraries
2840     [LINK_FOR_BUILD]: new variable
2841     [OBJEXT]: use throughout
2842     [EXEEXT]: use throughout
2843     <winshared>: new target
2844     <wininstall>: new target
2845     <dftables.o>: use native compiler
2846     <dftables>: use native linker
2847     <install>: handle Windows platform correctly
2848     <clean>: ditto
2849     <check>: ditto
2850     copy DLL to top builddir before testing
2852     As part of these changes, -no-undefined was removed again. This was reported
2853     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2854     in any case.
2856     3. Some tidies to get rid of compiler warnings:
2858     . In the match_data structure, match_limit was an unsigned long int, whereas
2859     match_call_count was an int. I've made them both unsigned long ints.
2861     . In pcretest the fact that a const uschar * doesn't automatically cast to
2862     a void * provoked a warning.
2864     . Turning on some more compiler warnings threw up some "shadow" variables
2865     and a few more missing casts.
2867     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2868     option, a class that contained a single character with a value between 128
2869     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2871     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2872     option, a class that contained several characters, but with at least one
2873     whose value was between 128 and 255 caused PCRE to crash.
2876 nigel 65 Version 4.1 12-Mar-03
2877     ---------------------
2878 nigel 63
2879 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2880     needed, and a string in dftables.c that was longer than standard compilers are
2881     required to support.
2883     2. Compiling with Sun's compiler found a few more places where the code could
2884     be tidied up in order to avoid warnings.
2886     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2887     first of these names is deprecated in the latest Autoconf in favour of the name
2888     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2889     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2890     analogy I have changed it to CFLAGS_FOR_BUILD.
2892     4. Added -no-undefined to the linking command in the Makefile, because this is
2893     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2894     linking step for the pcreposix library.
2896     5. PCRE was failing to diagnose the case of two named groups with the same
2897     name.
2899     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2900     literal character that is needed in the subject for a match, and scans along to
2901     ensure that it is present before embarking on the full matching process. This
2902     saves time in cases of nested unlimited repeats that are never going to match.
2903     Problem: the scan can take a lot of time if the subject is very long (e.g.
2904     megabytes), thus penalizing straightforward matches. It is now done only if the
2905     amount of subject to be scanned is less than 1000 bytes.
2907     7. A lesser problem with the same optimization is that it was recording the
2908     first character of an anchored pattern as "needed", thus provoking a search
2909     right along the subject, even when the first match of the pattern was going to
2910     fail. The "needed" character is now not set for anchored patterns, unless it
2911     follows something in the pattern that is of non-fixed length. Thus, it still
2912     fulfils its original purpose of finding quick non-matches in cases of nested
2913     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2916     Version 4.0 17-Feb-03
2917     ---------------------
2919 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2920     extended to the end of string, PCRE compiled incorrect data. This could lead to
2921     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2923     2. Moved to autoconf 2.53 and libtool 1.4.2.
2925     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2926     the special perltest8 script is no longer needed - all the tests can be run
2927     from a single perltest script.
2929     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2930     by \s. It has now been removed in PCRE. This means it isn't recognized as
2931     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2932     class [:space:] *does* include VT, thereby creating a mess.
2934     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2935     space and tab.
2937     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2938     its new features into the main test script, reducing the number of scripts.
2940     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2941     were backward compatible, and made the (?i) apply to the whole pattern, as if
2942     /i were given. Now it behaves more logically, and applies the option setting
2943     only to what follows. PCRE has been changed to follow suit. However, if it
2944     finds options settings right at the start of the pattern, it extracts them into
2945     the global options, as before. Thus, they show up in the info data.
2947     8. Added support for the \Q...\E escape sequence. Characters in between are
2948     treated as literals. This is slightly different from Perl in that $ and @ are
2949     also handled as literals inside the quotes. In Perl, they will cause variable
2950     interpolation. Note the following examples:
2952     Pattern PCRE matches Perl matches
2954     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2955     \Qabc\$xyz\E abc\$xyz abc\$xyz
2956     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2958     For compatibility with Perl, \Q...\E sequences are recognized inside character
2959     classes as well as outside them.
2961     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2962     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2963     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2964     signed/unsigned warnings.
2966     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2967     option for pcretest, so I've replaced it by a simple function that does just
2968     that job.
2970     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2971     "pcregrep -".
2973     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2974     Java package. This provides some syntactic sugar for simple cases of what my
2975     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2976     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2977     item, you can use this simplified notation. Note that only makes sense with
2978     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2979     greediness, whatever the setting of the PCRE_UNGREEDY option.
2981     13. A change of greediness default within a pattern was not taking effect at
2982     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2983     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2984     was abstracted outside.
2986     14. PCRE now supports the \G assertion. It is true when the current matching
2987     position is at the start point of the match. This differs from \A when the
2988     starting offset is non-zero. Used with the /g option of pcretest (or similar
2989     code), it works in the same way as it does for Perl's /g option. If all
2990     alternatives of a regex begin with \G, the expression is anchored to the start
2991     match position, and the "anchored" flag is set in the compiled expression.
2993     15. Some bugs concerning the handling of certain option changes within patterns
2994     have been fixed. These applied to options other than (?ims). For example,
2995     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2996     been the other way round. Some of this was related to change 7 above.
2998     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2999     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3000     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3001     POSIX classes only within a class (e.g. /[[:alpha:]]/).
3003     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3004     mode. Unlike ".", it always matches newline, whatever the setting of
3005     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3006     assertions. Perl allows it, but it doesn't (in general) work because it can't
3007     calculate the length of the lookbehind. At least, that's the case for Perl
3008     5.8.0 - I've been told they are going to document that it doesn't work in
3009     future.
3011     18. Added an error diagnosis for escapes that PCRE does not support: these are
3012     \L, \l, \N, \P, \p, \U, \u, and \X.
3014     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3015     reading past the end of the pattern in cases such as /[abcd/.
3017     20. PCRE was getting more memory than necessary for patterns with classes that
3018     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3020     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3021     compiling PCRE for use with Virtual Pascal.
3023     22. Small fix to the Makefile to make it work properly if the build is done
3024     outside the source tree.
3026     23. Added a new extension: a condition to go with recursion. If a conditional
3027     subpattern starts with (?(R) the "true" branch is used if recursion has
3028     happened, whereas the "false" branch is used only at the top level.
3030     24. When there was a very long string of literal characters (over 255 bytes
3031     without UTF support, over 250 bytes with UTF support), the computation of how
3032     much memory was required could be incorrect, leading to segfaults or other
3033     strange effects.
3035     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3036     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3037     there was a subsequent back reference to those brackets. This meant that, for
3038     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3039     possible to check for precisely this case. All we can do is abandon the
3040     optimization if .* occurs inside capturing brackets when there are any back
3041     references whatsoever. (See below for a better fix that came later.)
3043     26. The handling of the optimization for finding the first character of a
3044     non-anchored pattern, and for finding a character that is required later in the
3045     match were failing in some cases. This didn't break the matching; it just
3046     failed to optimize when it could. The way this is done has been re-implemented.
3048     27. Fixed typo in error message for invalid (?R item (it said "(?p").
3050     28. Added a new feature that provides some of the functionality that Perl
3051     provides with (?{...}). The facility is termed a "callout". The way it is done
3052     in PCRE is for the caller to provide an optional function, by setting
3053     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3054     global variable. By default it is unset, which disables all calling out. To get
3055     the function called, the regex must include (?C) at appropriate points. This
3056     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3057     This provides a means of identifying different callout points. When PCRE
3058     reaches such a point in the regex, if pcre_callout has been set, the external
3059     function is called. It is provided with data in a structure called
3060     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3061     matching continues; if it returns a non-zero value, the match at the current
3062     point fails. However, backtracking will occur if possible. [This was changed
3063     later and other features added - see item 49 below.]
3065     29. pcretest is upgraded to test the callout functionality. It provides a
3066     callout function that displays information. By default, it shows the start of
3067     the match and the current position in the text. There are some new data escapes
3068     to vary what happens:
3070     \C+ in addition, show current contents of captured substrings
3071     \C- do not supply a callout function
3072     \C!n return 1 when callout number n is reached
3073     \C!n!m return 1 when callout number n is reached for the mth time
3075     30. If pcregrep was called with the -l option and just a single file name, it
3076     output "<stdin>" if a match was found, instead of the file name.
3078     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3079     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3080     pcre_exec(). This saves a malloc/free per call. The default value of
3081     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3082     when configuring.
3084     32. The default maximum size of a compiled pattern is 64K. There have been a
3085     few cases of people hitting this limit. The code now uses macros to handle the
3086     storing of links as offsets within the compiled pattern. It defaults to 2-byte
3087     links, but this can be changed to 3 or 4 bytes by --with-link-size when
3088     configuring. Tests 2 and 5 work only with 2-byte links because they output
3089     debugging information about compiled patterns.
3091     33. Internal code re-arrangements:
3093     (a) Moved the debugging function for printing out a compiled regex into
3094     its own source file (printint.c) and used #include to pull it into
3095     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3096     separate copies.
3098     (b) Defined the list of op-code names for debugging as a macro in
3099     internal.h so that it is next to the definition of the opcodes.
3101     (c) Defined a table of op-code lengths for simpler skipping along compiled
3102     code. This is again a macro in internal.h so that it is next to the
3103     definition of the opcodes.
3105     34. Added support for recursive calls to individual subpatterns, along the
3106     lines of Robin Houston's patch (but implemented somewhat differently).
3108     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3109     allow it to read and process whole directories in Win32. This code was
3110     contributed by Lionel Fourquaux; it has not been tested by me.
3112     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3113     used to name a group. Names consist of alphanumerics and underscores, and must
3114     be unique. Back references use the syntax (?P=name) and recursive calls use
3115     (?P>name) which is a PCRE extension to the Python extension. Groups still have
3116     numbers. The function pcre_fullinfo() can be used after compilation to extract
3117     a name/number map. There are three relevant calls:
3119     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3120     PCRE_INFO_NAMECOUNT yields the number of entries
3121     PCRE_INFO_NAMETABLE yields a pointer to the map.
3123     The map is a vector of fixed-size entries. The size of each entry depends on
3124     the length of the longest name used. The first two bytes of each entry are the
3125     group number, most significant byte first. There follows the corresponding
3126     name, zero terminated. The names are in alphabetical order.
3128     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3129     case instead of 255. Making it the same both with and without UTF-8 support
3130     means that the same test output works with both.
3132     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3133     calling malloc() with a zero argument.
3135     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3136     optimization. I've improved things by keeping a bitmap of backreferences with
3137     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3138     fact referenced, the optimization can be applied. It is unlikely that a
3139     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3140     the match to follow \n) will appear inside brackets with a number greater than
3141     31, but if it does, any back reference > 31 suppresses the optimization.
3143     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3144     of disabling numbered capturing parentheses. Any opening parenthesis that is
3145     not followed by ? behaves as if it were followed by ?: but named parentheses
3146     can still be used for capturing (and they will acquire numbers in the usual
3147     way).
3149     41. Redesigned the return codes from the match() function into yes/no/error so
3150     that errors can be passed back from deep inside the nested calls. A malloc
3151     failure while inside a recursive subpattern call now causes the
3152     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3154     42. It is now possible to set a limit on the number of times the match()
3155     function is called in a call to pcre_exec(). This facility makes it possible to
3156     limit the amount of recursion and backtracking, though not in a directly
3157     obvious way, because the match() function is used in a number of different
3158     circumstances. The count starts from zero for each position in the subject
3159     string (for non-anchored patterns). The default limit is, for compatibility, a
3160     large number, namely 10 000 000. You can change this in two ways:
3162     (a) When configuring PCRE before making, you can use --with-match-limit=n
3163     to set a default value for the compiled library.
3165     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3166     a different value is set. See 45 below.
3168     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3170     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3171     of things that can be changed at compile time. The first argument specifies
3172     what is wanted and the second points to where the information is to be placed.
3173     The current list of available information is:
3177     The output is an integer that is set to one if UTF-8 support is available;
3178     otherwise it is set to zero.
3182     The output is an integer that it set to the value of the code that is used for
3183     newline. It is either LF (10) or CR (13).
3187     The output is an integer that contains the number of bytes used for internal
3188     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3192     The output is an integer that contains the threshold above which the POSIX
3193     interface uses malloc() for output vectors. See item 31 above.
3197     The output is an unsigned integer that contains the default limit of the number
3198     of match() calls in a pcre_exec() execution. See 42 above.
3200     44. pcretest has been upgraded by the addition of the -C option. This causes it
3201     to extract all the available output from the new pcre_config() function, and to
3202     output it. The program then exits immediately.
3204     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3205     order to support additional features. One way would have been to define
3206     pcre_exec2() (for example) with extra arguments, but this would not have been
3207     extensible, and would also have required all calls to the original function to
3208     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3209     is used for passing in "extra" data from pcre_study().
3211     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3212     contains the following fields:
3214     flags a bitmap indicating which of the following fields are set
3215     study_data opaque data from pcre_study()
3216     match_limit a way of specifying a limit on match() calls for a specific
3217     call to pcre_exec()
3218     callout_data data for callouts (see 49 below)
3220     The flag bits are also defined in pcre.h, and are
3226     The pcre_study() function now returns one of these new pcre_extra blocks, with
3227     the actual study data pointed to by the study_data field, and the
3228     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3229     before. That is, this change is entirely upwards-compatible and requires no
3230     change to existing code.
3232     If you want to pass in additional data to pcre_exec(), you can either place it
3233     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3234     block.
3236     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3237     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3238     times with different match limits, until it finds the minimum value needed for
3239     pcre_exec() to complete. The value is then output. This can be instructive; for
3240     most simple matches the number is quite small, but for pathological cases it
3241     gets very large very quickly.
3243     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3244     returns the size of the data block pointed to by the study_data field in a
3245     pcre_extra block, that is, the value that was passed as the argument to
3246     pcre_malloc() when PCRE was getting memory in which to place the information
3247     created by pcre_study(). The fourth argument should point to a size_t variable.
3248     pcretest has been extended so that this information is shown after a successful
3249     pcre_study() call when information about the compiled regex is being displayed.
3251     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3252     because what follows is always an absolute path. (Later: it turns out that this
3253     is more than cosmetic for MinGW, because it doesn't like empty path
3254     components.)
3256     49. Some changes have been made to the callout feature (see 28 above):
3258     (i) A callout function now has three choices for what it returns:
3260     0 => success, carry on matching
3261     > 0 => failure at this point, but backtrack if possible
3262     < 0 => serious error, return this value from pcre_exec()
3264     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3265     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3266     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3267     use by callout functions. It will never be used by PCRE itself.
3269     (ii) The pcre_extra structure (see 45 above) has a void * field called
3270     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3271     pcre_callout_block structure has a field of the same name. The contents of
3272     the field passed in the pcre_extra structure are passed to the callout
3273     function in the corresponding field in the callout block. This makes it
3274     easier to use the same callout-containing regex from multiple threads. For
3275     testing, the pcretest program has a new data escape
3277     \C*n pass the number n (may be negative) as callout_data
3279     If the callout function in pcretest receives a non-zero value as
3280     callout_data, it returns that value.
3282     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3283     there were some redundant $(CFLAGS) in commands that are now specified as
3284     $(LINK), which already includes $(CFLAGS).
3286     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3287     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3288     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3289     one-byte characters throughout. Note that case-insensitive matching applies
3290     only to characters whose values are less than 256. PCRE doesn't support the
3291     notion of cases for higher-valued characters.
3293     (i) A character class whose characters are all within 0-255 is handled as
3294     a bit map, and the map is inverted for negative classes. Previously, a
3295     character > 255 always failed to match such a class; however it should
3296     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3298     (ii) A negated character class with a single character < 255 is coded as
3299     "not this character" (OP_NOT). This wasn't working properly when the test
3300     character was multibyte, either singly or repeated.
3302     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3303     mode, for example: \x{100}{2,3}.
3305     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3306     singly or repeated) now correctly test multibyte characters. However,
3307     PCRE doesn't recognize any characters with values greater than 255 as
3308     digits, spaces, or word characters. Such characters always match \D, \S,
3309     and \W, and never match \d, \s, or \w.
3311     (v) Classes may now contain characters and character ranges with values
3312     greater than 255. For example: [ab\x{100}-\x{400}].
3314     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3315     PCRE in UTF-8 mode.
3317     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3318     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3319     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3320     value.)
3322     53. The single man page has become too large. I have therefore split it up into
3323     a number of separate man pages. These also give rise to individual HTML pages;
3324     these are now put in a separate directory, and there is an index.html page that
3325     lists them all. Some hyperlinking between the pages has been installed.
3327     54. Added convenience functions for handling named capturing parentheses.
3329     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3330     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3331     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3332     are faulted.
3334     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3335     calling configure. These values are used when compiling the dftables.c program
3336     which is run to generate the source of the default character tables. They
3337     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3338     you will need to set these values.
3340     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3343     Version 3.9 02-Jan-02
3344 nigel 61 ---------------------
3346     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3348     2. If --disable-static was given, the building process failed when trying to
3349     build pcretest and pcregrep. (For some reason it was using libtool to compile
3350     them, which is not right, as they aren't part of the library.)
3353 nigel 59 Version 3.8 18-Dec-01
3354     ---------------------
3356     1. The experimental UTF-8 code was completely screwed up. It was packing the
3357     bytes in the wrong order. How dumb can you get?
3360 nigel 57 Version 3.7 29-Oct-01
3361     ---------------------
3363     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3364     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3365     this didn't happen under Solaris 8, where I normally test things.
3367 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3368     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3369     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3370     this fix an hour or so after the initial 3.7 release.)
3371 nigel 57
3372 nigel 59
3373 nigel 55 Version 3.6 23-Oct-01
3374     ---------------------
3376     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3377     offsets passed as NULL with zero offset count.
3379     2. The config.guess and config.sub files had not been updated when I moved to
3380     the latest autoconf.
3383 nigel 53 Version 3.5 15-Aug-01
3384     ---------------------
3385 nigel 5
3386 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3387     had been forgotten.
3389     2. By using declared but undefined structures, we can avoid using "void"
3390     definitions in pcre.h while keeping the internal definitions of the structures
3391     private.
3393     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3394     user point of view, this means that both static and shared libraries are built
3395     by default, but this can be individually controlled. More of the work of
3396     handling this static/shared cases is now inside libtool instead of PCRE's make
3397     file.
3399     4. The pcretest utility is now installed along with pcregrep because it is
3400     useful for users (to test regexs) and by doing this, it automatically gets
3401     relinked by libtool. The documentation has been turned into a man page, so
3402     there are now .1, .txt, and .html versions in /doc.
3404     5. Upgrades to pcregrep:
3405     (i) Added long-form option names like gnu grep.
3406     (ii) Added --help to list all options with an explanatory phrase.
3407     (iii) Added -r, --recursive to recurse into sub-directories.
3408     (iv) Added -f, --file to read patterns from a file.
3410     6. pcre_exec() was referring to its "code" argument before testing that
3411     argument for NULL (and giving an error if it was NULL).
3413     7. Upgraded Makefile.in to allow for compiling in a different directory from
3414     the source directory.
3416     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3417     options bits, the pointer it was passed was to an int instead of to an unsigned
3418     long int. This mattered only on 64-bit systems.
3420     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3421     generated) instead of pcre.in, which it its source. Also made the same change
3422     in several of the .c files.
3424     10. A new release of gcc defines printf() as a macro, which broke pcretest
3425     because it had an ifdef in the middle of a string argument for printf(). Fixed
3426     by using separate calls to printf().
3428     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3429     script, to force use of CR or LF instead of \n in the source. On non-Unix
3430     systems, the value can be set in config.h.
3432     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3433     absolute limit. Changed the text of the error message to make this clear, and
3434     likewise updated the man page.
3436     13. The limit of 99 on the number of capturing subpatterns has been removed.
3437     The new limit is 65535, which I hope will not be a "real" limit.
3440 nigel 51 Version 3.4 22-Aug-00
3441     ---------------------
3443     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3445     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3448 nigel 49 Version 3.3 01-Aug-00
3449     ---------------------
3451     1. If an octal character was given, but the value was greater than \377, it
3452     was not getting masked to the least significant bits, as documented. This could
3453     lead to crashes in some systems.
3455     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3456     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3458     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3459     These just pass their arguments on to (pcre_free)(), but they are provided
3460     because some uses of PCRE bind it to non-C systems that can call its functions,
3461     but cannot call free() or pcre_free() directly.
3463     4. Add "make test" as a synonym for "make check". Corrected some comments in
3464     the Makefile.
3466     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3467     Makefile.
3469     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3470     command called pgrep for grepping around the active processes.
3472     7. Added the beginnings of support for UTF-8 character strings.
3474     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3475     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3476     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3477     out for the ar command.)
3480 nigel 47 Version 3.2 12-May-00
3481     ---------------------
3483     This is purely a bug fixing release.
3485     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3486     of ZA. This was just one example of several cases that could provoke this bug,
3487     which was introduced by change 9 of version 2.00. The code for breaking
3488     infinite loops after an iteration that matches an empty string was't working
3489     correctly.
3491     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3492     when matched against abbab (for example). After matching an empty string, it
3493     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3494     caused it to match further down the string than it should.
3496     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3497     was there because it doesn't seem to be needed, and it causes trouble on some
3498     systems, as it is not a Standard C header. It has been removed.
3500     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3501     were reported on the Macintosh. The changes were from
3503     while ((c = *(++ptr)) != 0 && c != '\n');
3504     to
3505     while ((c = *(++ptr)) != 0 && c != '\n') ;
3507     Totally extraordinary, but if that's what it takes...
3509     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3510     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3511     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3512     assumes the way PCRE uses memmove() (always moving upwards).
3514     6. PCRE is being used in one environment where strchr() is not available. There
3515     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3516     faster code anyway.
3519 nigel 45 Version 3.1 09-Feb-00
3520     ---------------------
3522     The only change in this release is the fixing of some bugs in Makefile.in for
3523     the "install" target:
3525     (1) It was failing to install pcreposix.h.
3527     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3530 nigel 43 Version 3.0 01-Feb-00
3531     ---------------------
3532 nigel 41
3533     1. Add support for the /+ modifier to perltest (to output $` like it does in
3534     pcretest).
3536     2. Add support for the /g modifier to perltest.
3538     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3539     matches null strings.
3541     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3542     pattern. Perl treats empty patterns specially - it reuses the most recent
3543     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3544     effect.
3546     5. The POSIX interface was broken in that it was just handing over the POSIX
3547     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3548     required a bigger vector, with some working space on the end. This means that
3549     the POSIX wrapper now has to get and free some memory, and copy the results.
3551 nigel 43 6. Added some simple autoconf support, placing the test data and the
3552     documentation in separate directories, re-organizing some of the
3553     information files, and making it build pcre-config (a GNU standard). Also added
3554     libtool support for building PCRE as a shared library, which is now the
3555     default.
3556 nigel 41
3557 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3558     09 are not valid octal constants. Single digits will be used for minor values
3559     less than 10.
3561     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3562     existing programs that set these in the POSIX interface can use PCRE without
3563     modification.
3565     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3566     return all that pcre_info() returns, plus additional data. The pcre_info()
3567     function is retained for compatibility, but is considered to be obsolete.
3569     10. Added experimental recursion feature (?R) to handle one common case that
3570     Perl 5.6 will be able to do with (?p{...}).
3572     11. Added support for POSIX character classes like [:alpha:], which Perl is
3573     adopting.
3576 nigel 39 Version 2.08 31-Aug-99
3577     ----------------------
3579     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3580     trying to match at the startoffset position, but instead was moving forward to
3581     the next newline as if a previous match had failed.
3583     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3584     and could get into a loop if a null string was matched other than at the start
3585     of the subject.
3587     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3588     be distinguished at compile time, and for completeness also added PCRE_DATE.
3590     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3591     in GnuWin32 environments.
3594 nigel 37 Version 2.07 29-Jul-99
3595     ----------------------
3597     1. The documentation is now supplied in plain text form and HTML as well as in
3598     the form of man page sources.
3600     2. C++ compilers don't like assigning (void *) values to other pointer types.
3601     In particular this affects malloc(). Although there is no problem in Standard
3602     C, I've put in casts to keep C++ compilers happy.
3604     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3605     should be (const char *).
3607     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3608     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3609     However, I haven't made this a standard facility. The documentation doesn't
3610     mention it, and the Makefile doesn't support it.
3612     5. The Makefile now contains an "install" target, with editable destinations at
3613     the top of the file. The pcretest program is not installed.
3615     6. pgrep -V now gives the PCRE version number and date.
3617     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3618     causing the entire string to be ignored, instead of just the last character.
3620     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3621     non-matching string, it can take a very, very long time, even for strings of
3622     quite modest length, because of the nested recursion. PCRE now does better in
3623     some of these cases. It does this by remembering the last required literal
3624     character in the pattern, and pre-searching the subject to ensure it is present
3625     before running the real match. In other words, it applies a heuristic to detect
3626     some types of certain failure quickly, and in the above example, if presented
3627     with a string that has no trailing " it gives "no match" very quickly.
3629     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3630     other alternatives are tried instead.
3633 nigel 35 Version 2.06 09-Jun-99
3634     ----------------------
3636     1. Change pcretest's output for amount of store used to show just the code
3637     space, because the remainder (the data block) varies in size between 32-bit and
3638     64-bit systems.
3640     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3641     start matching at. This allows lookbehinds to work when searching for multiple
3642     occurrences in a string.
3644     3. Added additional options to pcretest for testing multiple occurrences:
3646     /+ outputs the rest of the string that follows a match
3647     /g loops for multiple occurrences, using the new startoffset argument
3648     /G loops for multiple occurrences by passing an incremented pointer
3650     4. PCRE wasn't doing the "first character" optimization for patterns starting
3651     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3652     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3653     the letter 'x'. On long subject strings, this gives a significant speed-up.
3656 nigel 33 Version 2.05 21-Apr-99
3657     ----------------------
3659     1. Changed the type of magic_number from int to long int so that it works
3660     properly on 16-bit systems.
3662     2. Fixed a bug which caused patterns starting with .* not to work correctly
3663     when the subject string contained newline characters. PCRE was assuming
3664     anchoring for such patterns in all cases, which is not correct because .* will
3665     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3666     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3667     must be retried after every newline in the subject.
3670 nigel 31 Version 2.04 18-Feb-99
3671     ----------------------
3673     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3674     computation of the store needed to hold the pattern was incorrect (too large).
3675     If such patterns were nested a few deep, this could multiply and become a real
3676     problem.
3678     2. Added /M option to pcretest to show the memory requirement of a specific
3679     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3681     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3682     compiled in such a way that the backtracking after subsequent failure was
3683     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3684     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3687 nigel 29 Version 2.03 02-Feb-99
3688     ----------------------
3690     1. Fixed typo and small mistake in man page.
3692 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3693     LICENCE file containing the conditions.
3694 nigel 29
3695     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3696     Perl, that is the internal \ allows the delimiter to be included in the
3697     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3698     the final delimiter, add \ to the end of the pattern (to test the error).
3700     4. Added the convenience functions for extracting substrings after a successful
3701     match. Updated pcretest to make it able to test these functions.
3704 nigel 27 Version 2.02 14-Jan-99
3705     ----------------------
3707     1. Initialized the working variables associated with each extraction so that
3708     their saving and restoring doesn't refer to uninitialized store.
3710     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3711     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3712     fix the problem.
3714     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3715     calls, and wasn't printing the correct value for compiling calls. Increased the
3716     default value of LOOPREPEAT, and the number of significant figures in the
3717     times.
3719     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3721     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3722     a building problem on Windows NT with a FAT file system.
3725 nigel 25 Version 2.01 21-Oct-98
3726     ----------------------
3728     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3729     to character tables built by pcre_maketables() in the current locale. If NULL
3730     is passed, the default tables are used.
3733 nigel 23 Version 2.00 24-Sep-98
3734 nigel 21 ----------------------
3736 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3737     it any more.
3739     2. Allow quantification of (?>) groups, and make it work correctly.
3741     3. The first character computation wasn't working for (?>) groups.
3743     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3744     end of the subject) and add 5.005's \z, which really does match only at the
3745     very end of the subject.
3747     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3749     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3750     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3751     localized options. All options to pcre_study() were also removed.
3753     7. Add other new features from 5.005:
3755     $(?<= positive lookbehind
3756     $(?<! negative lookbehind
3757     (?imsx-imsx) added the unsetting capability
3758     such a setting is global if at outer level; local otherwise
3759     (?imsx-imsx:) non-capturing groups with option setting
3760     (?(cond)re|re) conditional pattern matching
3762     A backreference to itself in a repeated group matches the previous
3763     captured string.
3765     8. General tidying up of studying (both automatic and via "study")
3766     consequential on the addition of new assertions.
3768     9. As in 5.005, unlimited repeated groups that could match an empty substring
3769     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3770     runtime if any iteration does actually match an empty substring.
3772     10. Include the RunTest script in the distribution.
3774     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3775     discrepancies, some of which were old and were also with respect to 5.004. They
3776     have now been fixed.
3779     Version 1.09 28-Apr-98
3780     ----------------------
3782 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3783     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3784     program crashes, or just wrong answers. This did not apply to negated classes
3785     containing more than one character, or to minima other than one.
3788 nigel 19 Version 1.08 27-Mar-98
3789     ----------------------
3791     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3793     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The