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Revision 583 - (hide annotations) (download)
Tue Jan 11 16:49:55 2011 UTC (3 years, 9 months ago) by ph10
File size: 196803 byte(s)
Add script to check for man page markup typos. Fix some typos.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 583 Version 8.12 11-Jan-2011
5     ------------------------
7     1. Fixed some typos in the markup of the man pages, and wrote a script that
8     checks for such things as part of the documentation building process.
11 ph10 581 Version 8.11 10-Dec-2010
12 ph10 550 ------------------------
14     1. (*THEN) was not working properly if there were untried alternatives prior
15 ph10 579 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
16     backtracked to try for "b" instead of moving to the next alternative branch
17     at the same level (in this case, to look for "c"). The Perl documentation
18     is clear that when (*THEN) is backtracked onto, it goes to the "next
19 ph10 550 alternative in the innermost enclosing group".
20 ph10 579
21     2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
22 ph10 551 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
23     result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
24 ph10 579 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
25     (*THEN).
27 ph10 552 3. If \s appeared in a character class, it removed the VT character from
28     the class, even if it had been included by some previous item, for example
29 ph10 579 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
30     of \s, but is part of the POSIX "space" class.)
32 ph10 553 4. A partial match never returns an empty string (because you can always
33     match an empty string at the end of the subject); however the checking for
34     an empty string was starting at the "start of match" point. This has been
35     changed to the "earliest inspected character" point, because the returned
36     data for a partial match starts at this character. This means that, for
37     example, /(?<=abc)def/ gives a partial match for the subject "abc"
38     (previously it gave "no match").
39 ph10 550
40 ph10 553 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
41 ph10 579 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
42 ph10 553 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
43 ph10 579 has an implication that the given string is incomplete (because a partial
44     match is preferred over a full match). For this reason, these items now
45 ph10 553 give a partial match in this situation. [Aside: previously, the one case
46     /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
47 ph10 579 match rather than a full match, which was wrong by the old rules, but is
48     now correct.]
50 ph10 556 6. There was a bug in the handling of #-introduced comments, recognized when
51     PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
52     If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
53     UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
54     scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
55 ph10 579 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
56 ph10 556 places in pcre_compile().
57 ph10 579
58     7. Related to (6) above, when pcre_compile() was skipping #-introduced
59     comments when looking ahead for named forward references to subpatterns,
60     the only newline sequence it recognized was NL. It now handles newlines
61 ph10 556 according to the set newline convention.
62 ph10 579
63     8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
64     former, but used strtoul(), whereas pcretest avoided strtoul() but did not
65 ph10 558 cater for a lack of strerror(). These oversights have been fixed.
66 ph10 550
67 ph10 579 9. Added --match-limit and --recursion-limit to pcregrep.
69 ph10 563 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
70 ph10 553
71 ph10 564 11. When the -o option was used, pcregrep was setting a return code of 1, even
72     when matches were found, and --line-buffered was not being honoured.
73 ph10 579
74 ph10 565 12. Added an optional parentheses number to the -o and --only-matching options
75 ph10 579 of pcregrep.
77 ph10 566 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
78 ph10 579 can match an empty string. The code to do it in pcretest and pcredemo
79 ph10 566 needed fixing:
80 ph10 579
81 ph10 566 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
82     only one byte after an empty string match just before CRLF (this case
83     just got forgotten; "any" and "anycrlf" were OK).
84 ph10 579
85 ph10 566 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
86 ph10 579 mode when an empty string match preceded an ASCII character followed by
87 ph10 566 a non-ASCII character. (The code for advancing by one character rather
88 ph10 579 than one byte was nonsense.)
90 ph10 566 (c) The pcredemo.c sample program did not have any code at all to handle
91 ph10 579 the cases when CRLF is a valid newline sequence.
93 ph10 567 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
94     as a starting offset was within the subject string. There is now a new
95 ph10 579 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
96     negative or greater than the length of the string. In order to test this,
97 ph10 567 pcretest is extended to allow the setting of negative starting offsets.
98 ph10 579
99     15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
100     starting offset points to the beginning of a UTF-8 character was
101     unnecessarily clumsy. I tidied it up.
103 ph10 569 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
104 ph10 579 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
106     17. Nobody had reported that the --include_dir option, which was added in
107     release 7.7 should have been called --include-dir (hyphen, not underscore)
108     for compatibility with GNU grep. I have changed it to --include-dir, but
109     left --include_dir as an undocumented synonym, and the same for
110     --exclude-dir, though that is not available in GNU grep, at least as of
111     release 2.5.4.
113     18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
114 ph10 573 characters from a string of bytes) have been redefined so as not to use
115 ph10 579 loops, in order to improve performance in some environments. At the same
116     time, I abstracted some of the common code into auxiliary macros to save
117 ph10 573 repetition (this should not affect the compiled code).
118 ph10 579
119     19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
120     compile-time error is now given if \c is not followed by an ASCII
121     character, that is, a byte less than 128. (In EBCDIC mode, the code is
122 ph10 574 different, and any byte value is allowed.)
123 ph10 579
124 ph10 576 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
125     START_OPTIMIZE option, which is now allowed at compile time - but just
126     passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
127 ph10 579 to pcregrep and other applications that have no direct access to PCRE
128     options. The new /Y option in pcretest sets this option when calling
129     pcre_compile().
131 ph10 578 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
132 ph10 579 back references. Groups containing recursive back references were forced to
133     be atomic by that change, but in the case of named groups, the amount of
134     memory required was incorrectly computed, leading to "Failed: internal
135     error: code overflow". This has been fixed.
136 ph10 563
137 ph10 580 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
138     pcretest.c, to avoid build problems in some Borland environments.
139 ph10 564
140 ph10 580
141 ph10 548 Version 8.10 25-Jun-2010
142 ph10 510 ------------------------
144 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
145 ph10 510 THEN.
147 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
148 ph10 510
149 ph10 535 3. Inside a character class, \B is treated as a literal by default, but
150     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
151 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
152 ph10 535
153     4. Inside a character class, PCRE always treated \R and \X as literals,
154 ph10 513 whereas Perl faults them if its -w option is set. I have changed PCRE so
155     that it faults them when PCRE_EXTRA is set.
156 ph10 535
157 ph10 514 5. Added support for \N, which always matches any character other than
158     newline. (It is the same as "." when PCRE_DOTALL is not set.)
159 ph10 535
160 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
161 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
162 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
163 ph10 535 result to (void) does not stop the warnings; a more elaborate fudge is
164     needed. I've used a macro to implement this.
165 ph10 512
166 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
168 ph10 517 8. Added four artifical Unicode properties to help with an option to make
169 ph10 518 \s etc use properties (see next item). The new properties are: Xan
170     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
171 ph10 535
172 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
173 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
174 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
175     REG_UCP to make it available via the POSIX interface.
176 ph10 513
177 ph10 535 10. Added --line-buffered to pcregrep.
179     11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
180     studied, and the match started with a letter with a code point greater than
181 ph10 520 127 whose first byte was different to the first byte of the other case of
182 ph10 545 the letter, the other case of this starting letter was not recognized
183 ph10 536 (#976).
184 ph10 535
185 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
186 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
187 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
188     not have actually happened in practice until change 8 above was made (it
189 ph10 523 added property types that matched character-matching opcodes).
190 ph10 535
191 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
192 ph10 535 possible starting bytes for non-anchored patterns.
194 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
195 ph10 535 \R, and also a number of cases that involve Unicode properties, both
196 ph10 532 explicit and implicit when PCRE_UCP is set.
197 ph10 529
198 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
199 ph10 535 input, it could crash or give wrong results if characters with values
200     greater than 0xc0 were present in the subject string. (Detail: it assumed
201 ph10 529 UTF-8 input when processing these items.)
202 ph10 535
203 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
204     size_t is 64-bit (#991).
205 ph10 535
206 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
207     --disable-stack-for-recursion (#990).
208 ph10 545
209 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
210 ph10 545 the end, a newline was missing in the output.
212     19. The default pcre_chartables.c file recognizes only ASCII characters (values
213     less than 128) in its various bitmaps. However, there is a facility for
214     generating tables according to the current locale when PCRE is compiled. It
215     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
216     characters, are recognized by isspace() and therefore were getting set in
217 ph10 541 these tables, and indeed these tables seem to approximate to ISO 8859. This
218     caused a problem in UTF-8 mode when pcre_study() was used to create a list
219     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
220     which of course cannot start UTF-8 characters. I have changed the code so
221     that only real ASCII characters (less than 128) and the correct starting
222 ph10 545 bytes for UTF-8 encodings are set for characters greater than 127 when in
223 ph10 541 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
224     altogether.)
225 ph10 545
226 ph10 541 20. Added the /T option to pcretest so as to be able to run tests with non-
227     standard character tables, thus making it possible to include the tests
228 ph10 545 used for 19 above in the standard set of tests.
230     21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
231     reference to a subpattern the other side of a comment that contains an
232     opening parenthesis caused either an internal compiling error, or a
233 ph10 544 reference to the wrong subpattern.
234 ph10 517
235 ph10 520
236 ph10 508 Version 8.02 19-Mar-2010
237 ph10 491 ------------------------
239     1. The Unicode data tables have been updated to Unicode 5.2.0.
241 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
242     configured.
243 ph10 507
244 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
245 ph10 507 original author of that file, following a query about its status.
247     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
248 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
249 ph10 507
250 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
251     quantifier applied to a forward-referencing subroutine call, could compile
252     incorrect code or give the error "internal error: previously-checked
253     referenced subpattern not found".
254 ph10 507
255     6. Both MS Visual Studio and Symbian OS have problems with initializing
256 ph10 497 variables to point to external functions. For these systems, therefore,
257     pcre_malloc etc. are now initialized to local functions that call the
258     relevant global functions.
259 ph10 507
260 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
261     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
262 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
263     the lengths are correct (equal to the number of opcodes).
265     8. Following on from 7, I added a similar kludge to check the length of the
266     eint vector in pcreposix.c.
268     9. Error texts for pcre_compile() are held as one long string to avoid too
269     much relocation at load time. To find a text, the string is searched,
270 ph10 499 counting zeros. There was no check for running off the end of the string,
271     which could happen if a new error number was added without updating the
272 ph10 507 string.
274     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
276 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
277 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
278     \K is "not well defined" if used in an assertion. PCRE now accepts it if
279     the assertion is positive, but not if it is negative.
281 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
282 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
283     implementation of support for (*MARK) will need an extra pointer on the
284 ph10 501 stack; I have reserved it now, so that the stack frame size does not
285     decrease.
286 ph10 507
287     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
288     item in branch that calls a recursion is a subroutine call - as in the
289 ph10 503 second branch in the above example - was incorrectly given the compile-
290     time error "recursive call could loop indefinitely" because pcre_compile()
291 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
293 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
294 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
295 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
296 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
297 ph10 491
298 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
299 ph10 492
300 ph10 507
301 ph10 489 Version 8.01 19-Jan-2010
302     ------------------------
303 ph10 471
304     1. If a pattern contained a conditional subpattern with only one branch (in
305 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
306 ph10 473 computed the wrong minimum data length (which is of course zero for such
307 ph10 489 subpatterns). This could cause incorrect "no match" results.
308 ph10 473
309     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
310 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
311     "internal error: code overflow at offset...". This happened only when
312 ph10 473 the reset was to the original external option setting. (An optimization
313     abstracts leading options settings into an external setting, which was the
314 ph10 472 cause of this.)
315 ph10 471
316 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
317     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
318     assertion pattern did not match (meaning that the assertion was true), it
319     was incorrectly treated as false if the SKIP had been reached during the
320     matching. This also applied to assertions used as conditions.
321 ph10 471
322 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
323     assertion subpattern, including such a pattern used as a condition,
324     unpredictable results occurred, instead of the error return
326 ph10 478
327 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
328     situation when an empty string is matched. It now does the fancy magic
329 ph10 478 stuff that is necessary.
331     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
332 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
333 ph10 478
334 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
335     as part of something else:
336 ph10 478
337     (a) Change DEBUG to PCRE_DEBUG.
339     (b) In pcre_compile(), rename the member of the "branch_chain" structure
340     called "current" as "current_branch", to prevent a collision with the
341 ph10 475 Linux macro when compiled as a kernel module.
342 ph10 478
343     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
344     prevent a collision with the Linux macro when compiled as a kernel
345 ph10 475 module.
346 ph10 478
347 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
348     cast potentially large values to (double). This has been changed to that
349 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
350     instead, thus avoiding the use of floating point arithmetic. (There is no
351     other use of FP in PCRE.) If int64_t is not found, the fallback is to
352     double.
354     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
355 ph10 476 2005 (difference between two addresses compared to an unsigned value).
356 ph10 473
357 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
358     custom one, because of the following reported problem in Windows:
359 ph10 473
360 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
361 ph10 489 under Win32.
362 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
363 ph10 489 therefore missing the function definition.
364 ph10 478 - The compiler thus generates a "C" signature for the test function.
365     - The linker fails to find the "C" function.
366     - PCRE fails to configure if asked to do so against libbz2.
367 ph10 486
368 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
369     messages were output:
370 ph10 478
371 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
372     rerunning libtoolize, to keep the correct libtool macros in-tree.
373     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
374 ph10 486
375 ph10 479 I have done both of these things.
376 ph10 486
377 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
378 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
379     runaway infinite recursion. I updated the discussion in the pcrestack man
380     page.
382     13. Now that we have gone to the x.xx style of version numbers, the minor
383     version may start with zero. Using 08 or 09 is a bad idea because users
384     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
385     interpreted as invalid octal numbers. I've updated the previous comment in
386     configure.ac, and also added a check that gives an error if 08 or 09 are
387 ph10 481 used.
388 ph10 486
389 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
390 ph10 483 causing partial matching to fail when the end of the subject matched \W
391     in a UTF-8 pattern where \W was quantified with a minimum of 3.
392 ph10 486
393 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
394 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
395 ph10 483 their definitions. The declarations used "const uschar *" and the
396     definitions used USPTR. Even though USPTR is normally defined as "const
397     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
398     reported that: "This difference in casting confuses some C++ compilers, for
399     example, SunCC recognizes above declarations as different functions and
400 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
401 ph10 483 USPTR.
402 ph10 486
403     16. GNU libtool is named differently on some systems. The autogen.sh script now
404 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
405     (FreeBSD).
406 ph10 478
407 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
408     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
409     comment: "Figure out how to create a longlong from a string: strtoll and
410     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
411     instance, but it only takes 2 args instead of 3!"
412 ph10 479
413 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
414     specification, with a corresponding code fix. A pattern such as
415     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
416     refers, was giving matches when it shouldn't. For example, xa=xaaa would
417     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
418     same bug. Such groups have to be quantified to be useful, or contained
419     inside another quantified group. (If there's no repetition, the reference
420     can never match.) The problem arises because, having left the group and
421     moved on to the rest of the pattern, a later failure that backtracks into
422     the group uses the captured value from the final iteration of the group
423     rather than the correct earlier one. I have fixed this in PCRE by forcing
424     any group that contains a reference to itself to be an atomic group; that
425     is, there cannot be any backtracking into it once it has completed. This is
426     similar to recursive and subroutine calls.
427 ph10 486
428 ph10 488
429 ph10 469 Version 8.00 19-Oct-09
430 ph10 418 ----------------------
432     1. The table for translating pcre_compile() error codes into POSIX error codes
433 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
434     being within the table. This could lead to an OK return being given in
435 ph10 418 error.
436 ph10 461
437     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
438     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
439     in a Windows environment.
441 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
442     zero, as does GNU grep. However, pcregrep was also printing all files when
443     --files-with-matches was added. Now, when both options are given, it prints
444     counts only for those files that have at least one match. (GNU grep just
445 ph10 461 prints the file name in this circumstance, but including the count seems
446     more useful - otherwise, why use --count?) Also ensured that the
447 ph10 420 combination -clh just lists non-zero counts, with no names.
448 ph10 461
449     4. The long form of the pcregrep -F option was incorrectly implemented as
450     --fixed_strings instead of --fixed-strings. This is an incompatible change,
451     but it seems right to fix it, and I didn't think it was worth preserving
452     the old behaviour.
454     5. The command line items --regex=pattern and --regexp=pattern were not
455 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
456 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
457 ph10 422 which are compatible with GNU grep; these now work.
458 ph10 461
459     6. No libpcreposix.pc file was created for pkg-config; there was just
460 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
461 ph10 461
462 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
463 ph10 461 when UCP support is not needed, by modifying the Python script that
464 ph10 425 generates it from Unicode data files. This should not matter if the module
465     is correctly used as a library, but I received one complaint about 50K of
466     unwanted data. My guess is that the person linked everything into his
467     program rather than using a library. Anyway, it does no harm.
468 ph10 461
469 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
470 ph10 461 was a minimum greater than 1 for a wide character in a possessive
471 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
472     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
473     character. Chaos in the form of incorrect output or a compiling loop could
474     result.
475 ph10 461
476 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
477 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
478 ph10 426 partially matched by this function. In addition, if there are at least two
479 ph10 435 slots in the offset vector, the offset of the earliest inspected character
480     for the match and the offset of the end of the subject are set in them when
481 ph10 461 PCRE_ERROR_PARTIAL is returned.
483 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
484     synonymous with PCRE_PARTIAL, for backwards compatibility, and
485     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
486 ph10 462 and may be more useful for multi-segment matching.
487 ph10 461
488     11. Partial matching with pcre_exec() is now more intuitive. A partial match
489     used to be given if ever the end of the subject was reached; now it is
490     given only if matching could not proceed because another character was
491     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
492     string "Z", which now yields "no match" instead of "partial match". In the
493     case of pcre_dfa_exec(), "no match" is given if every matching path for the
494     final character ended with (*FAIL).
496 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
497 ph10 461 if the pattern had a "must contain" character that was already found in the
498 ph10 428 earlier partial match, unless partial matching was again requested. For
499     example, with the pattern /dog.(body)?/, the "must contain" character is
500     "g". If the first part-match was for the string "dog", restarting with
501 ph10 435 "sbody" failed. This bug has been fixed.
502 ph10 461
503     13. The string returned by pcre_dfa_exec() after a partial match has been
504     changed so that it starts at the first inspected character rather than the
505     first character of the match. This makes a difference only if the pattern
506     starts with a lookbehind assertion or \b or \B (\K is not supported by
507     pcre_dfa_exec()). It's an incompatible change, but it makes the two
508 ph10 435 matching functions compatible, and I think it's the right thing to do.
509 ph10 461
510 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
511 ph10 461 so that the demonstration program is easily available in environments where
512     PCRE has not been installed from source.
514 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
515 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
516     library.
517 ph10 461
518 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
519 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
520 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
521 ph10 433 these options useful.
522 ph10 461
523     17. If a caller to the POSIX matching function regexec() passes a non-zero
524 ph10 438 value for nmatch with a NULL value for pmatch, the value of
525 ph10 461 nmatch is forced to zero.
527 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
528 ph10 461 the diff command, as RunTest does. It now checks in the same way as
529 ph10 437 RunTest, and also checks for the -b option.
530 ph10 461
531 ph10 438 19. If an odd number of negated classes containing just a single character
532     interposed, within parentheses, between a forward reference to a named
533 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
534     an internal error, complaining that it could not find the referenced
535 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
536 ph10 461 [The bug was that it was starting one character too far in when skipping
537     over the character class, thus treating the ] as data rather than
538     terminating the class. This meant it could skip too much.]
540 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
541 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
542 ph10 442 to have an empty string match not at the start, even when the pattern is
543 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
545 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
546 ph10 461 than the maximum at the outer level, the higher number was returned, but
547     with unset values at the outer level. The correct (outer level) value is
548 ph10 446 now given.
549 ph10 461
550 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
551     PCRE did not set those parentheses (unlike Perl). I have now found a way to
552     make it do so. The string so far is captured, making this feature
553     compatible with Perl.
554 ph10 461
555     23. The tests have been re-organized, adding tests 11 and 12, to make it
556 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
557 ph10 461
558 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
559 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
560     does. Neither allows recursion.
562     25. I finally figured out how to implement a request to provide the minimum
563     length of subject string that was needed in order to match a given pattern.
564     (It was back references and recursion that I had previously got hung up
565     on.) This code has now been added to pcre_study(); it finds a lower bound
566 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
567     bound, but using it to avoid searching strings that are too short does give
568     some useful speed-ups. The value is available to calling programs via
569     pcre_fullinfo().
570 ph10 461
571 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
572     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
573     study optimizations had never been tested with that matching function.
574     Oops. What is worse, even when it was passed study data, there was a bug in
575     pcre_dfa_exec() that meant it never actually used it. Double oops. There
576     were also very few tests of studied patterns with pcre_dfa_exec().
577 ph10 461
578 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
579     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
580     on the other side of the coin, they are no longer allowed to have different
581     names, because these cannot be distinguished in PCRE, and this has caused
582     confusion. (This is a difference from Perl.)
583 ph10 461
584     28. When duplicate subpattern names are present (necessarily with different
585     numbers, as required by 27 above), and a test is made by name in a
586     conditional pattern, either for a subpattern having been matched, or for
587     recursion in such a pattern, all the associated numbered subpatterns are
588 ph10 459 tested, and the overall condition is true if the condition is true for any
589     one of them. This is the way Perl works, and is also more like the way
590     testing by number works.
591 ph10 418
592 ph10 461
593 ph10 412 Version 7.9 11-Apr-09
594 ph10 376 ---------------------
596 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
597 ph10 376 (pcretest), all targets were linked against these libraries. This included
598     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
599     libraries. This caused unwanted dependencies to be created. This problem
600 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
601 ph10 376 pcretest is linked with readline.
602 ph10 392
603 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
604     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
605     moved outside it again, because FALSE and TRUE are already defined in AIX,
606     but BOOL is not.
607 ph10 392
608     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
609 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
610 ph10 392
611 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
612     hyphens) following file names and line numbers when outputting matching
613 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
614 ph10 376 wording for the --colour (or --color) option.
615 ph10 392
616 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
617     was not coloured; this is different to GNU grep, so I have changed it to be
618     the same.
619 ph10 392
620 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
621 ph10 392 each matching line was coloured. Now it goes on to look for further matches
622     of any of the test patterns, which is the same behaviour as GNU grep.
624     7. A pattern that could match an empty string could cause pcregrep to loop; it
625     doesn't make sense to accept an empty string match in pcregrep, so I have
626 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
627     seems to be how GNU grep behaves.
628 ph10 392
629 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
630 ph10 392 start or after a newline", because the conditional assertion was not being
631     correctly handled. The rule now is that both the assertion and what follows
632     in the first alternative must satisfy the test.
634 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
635 ph10 399 condition was an assertion, PCRE could crash during matching, both with
636     pcre_exec() and pcre_dfa_exec().
637 ph10 392
638     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
639     used for matching.
641     11. Unicode property support in character classes was not working for
642 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
643 ph10 388
644 ph10 392 12. Added the -M command line option to pcretest.
646 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
647 ph10 389
648     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
649 ph10 390
650 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
651 ph10 390 wrapper.
652 ph10 392
653 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
654 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
655 ph10 391 string constants.
656 ph10 405
657 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
658     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
659 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
660     these, but not everybody uses configure.
662     19. A conditional group that had only one branch was not being correctly
663     recognized as an item that could match an empty string. This meant that an
664     enclosing group might also not be so recognized, causing infinite looping
665     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
666     with the subject "ab", where knowledge that the repeated group can match
667 ph10 396 nothing is needed in order to break the loop.
668 ph10 405
669 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
670 ph10 405 exec(), but without supplying a callout function, matching went wrong.
672     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
673     leak if the size of the offset vector was greater than 30. When the vector
674     is smaller, the saved offsets during recursion go onto a local stack
675     vector, but for larger vectors malloc() is used. It was failing to free
676     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
677 ph10 400 error, in fact).
678 ph10 405
679 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
680 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
681     problem, but was untidy.
682 ph10 376
683 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
684     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
685     included within another project.
686 ph10 411
687 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
688     slightly modified by me:
689 ph10 411
690     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
691     not building pcregrep.
693 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
694 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
696 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
697     duplicate group numbers, could behave incorrectly or give incorrect errors,
698     because when scanning forward to find the reference group, PCRE was not
699     taking into account the duplicate group numbers. A pattern such as
700     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
701 ph10 411
702     26. Changed a few more instances of "const unsigned char *" to USPTR, making
703     the feature of a custom pointer more persuasive (as requested by a user).
704 ph10 416
705 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
706 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
707     pre-defined.
708 ph10 392
709 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
711 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
712     in the configuration summary.
713 ph10 405
714 ph10 411
715 ph10 374 Version 7.8 05-Sep-08
716 ph10 349 ---------------------
718     1. Replaced UCP searching code with optimized version as implemented for Ad
719     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
720 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
721     to 5 times on some simple patterns that I tested. Permission was given to
722     distribute the MultiStage2.py script that generates the tables (it's not in
723     the tarball, but is in the Subversion repository).
724 ph10 349
725 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
726     scripts.
727 ph10 358
728 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
729     a group with a zero qualifier. The result of the study could be incorrect,
730 ph10 358 or the function might crash, depending on the pattern.
732     4. Caseless matching was not working for non-ASCII characters in back
733 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
734 ph10 358 It now works when Unicode Property Support is available.
736 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
737     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
738     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
739 ph10 358 truncation.
740 ph10 349
741 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
743 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
744     pointers, in case they are 64-bit values.
745 ph10 371
746     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
747     test 2 if it fails.
749 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
750 ph10 371 and a #define of that name to empty if it is not externally set. This is to
751     allow users of MSVC to set it if necessary.
753     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
754 ph10 359 the convenience functions in the pcre_get.c source file.
755 ph10 371
756 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
757     could cause overwriting and/or a crash. This command provoked a crash in
758 ph10 371 some environments:
760     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
762 ph10 360 This potential security problem was recorded as CVE-2008-2371.
763 ph10 371
764 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
765     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
766 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
767 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
768     pcretest so that it places the subject at the end of its malloc-ed buffer.
769 ph10 371
770 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
771 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
773 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
774 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
775     first line. This applied both to normal and DFA matching.
777 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
778 ph10 371 /^[^d]*?$/8 failed to match "abc".
779 ph10 351
780 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
782     17. Make it more clear in the documentation that values returned from
783 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
784 ph10 357
785 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
786 ph10 368
787 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
788     supplied by Stefan Weber. I made a further small update for 7.8 because
789 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
790     replaced by pcre_ucd.c.
791 ph10 371
792 ph10 373
793 ph10 347 Version 7.7 07-May-08
794 ph10 321 ---------------------
796     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
797 ph10 345 a string to a long long, pretend we don't even have a long long." This is
798 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
799 ph10 345
800 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
801     pre-7.6 versions, which defined a global no_arg variable instead of putting
802 ph10 332 it in the RE class. (See also #8 below.)
803 ph10 345
804     3. Remove a line of dead code, identified by coverity and reported by Nuno
805     Lopes.
807 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
808 ph10 321
809 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
810 ph10 345 of files, instead of just to the final components.
812 ph10 324 (2) If there was more than one level of directory, the subdirectories were
813     skipped unless they satisfied the include/exclude conditions. This is
814     inconsistent with GNU grep (and could even be seen as contrary to the
815     pcregrep specification - which I improved to make it absolutely clear).
816     The action now is always to scan all levels of directory, and just
817     apply the include/exclude patterns to regular files.
818 ph10 345
819 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
820 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
822 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
823 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
824 ph10 326 doesn't support NULs in patterns.
825 ph10 345
826     7. Added some missing "const"s to declarations of static tables in
827     pcre_compile.c and pcre_dfa_exec.c.
829 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
830 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
831 ph10 345 first patch. And a third patch - this was a messy problem.)
832 ph10 321
833 ph10 345 9. Applied Craig's patch to remove the use of push_back().
835 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
836     matching function regexec().
837 ph10 345
838     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
839     which, however, unlike Perl's \g{...}, are subroutine calls, not back
840 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
841     Oniguruma does).
842 ph10 345
843     12. Previously, a group with a zero repeat such as (...){0} was completely
844 ph10 335 omitted from the compiled regex. However, this means that if the group
845     was called as a subroutine from elsewhere in the pattern, things went wrong
846 ph10 345 (an internal error was given). Such groups are now left in the compiled
847     pattern, with a new opcode that causes them to be skipped at execution
848 ph10 335 time.
849 ph10 345
850 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
851     to the way PCRE behaves:
852 ph10 345
853 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
854 ph10 345
855     (b) A back reference to an unmatched subpattern matches an empty string
856 ph10 336 (Perl fails the current match path).
857 ph10 345
858 ph10 341 (c) A data ] in a character class must be notated as \] because if the
859 ph10 345 first data character in a class is ], it defines an empty class. (In
860 ph10 341 Perl it is not possible to have an empty class.) The empty class []
861     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
862     The negative empty class [^] matches any one character, independently
863     of the DOTALL setting.
864 ph10 345
865     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
866 ph10 340 non-existent subpattern following a character class starting with ']' and
867     containing () gave an internal compiling error instead of "reference to
868     non-existent subpattern". Fortunately, when the pattern did exist, the
869 ph10 345 compiled code was correct. (When scanning forwards to check for the
870 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
871 ph10 345 the class, so got the count wrong. When actually compiling, the reference
872 ph10 340 was subsequently set up correctly.)
873 ph10 345
874 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
875 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
876     other assertions are supported. I have made pcre_dfa_exec() support
877     (*FAIL).
879 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
880 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
881     cannot be changed at match time, I realized I could make a small
882     improvement to matching performance by compiling OP_ALLANY instead of
883     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
884     on the OP_ANY path.
886     17. Compiling pcretest on Windows with readline support failed without the
887 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
888 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
890 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
891 ph10 345 ncurses library to be included for pcretest when ReadLine support is
892     requested, but also to allow for it to be overridden. This patch came from
893     Daniel Bergström.
894 ph10 347
895 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
896 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
897     any errors with the current Unicode tables. Thanks to Peter Kankowski for
898     spotting this.
899 ph10 324
900 ph10 332
901 ph10 319 Version 7.6 28-Jan-08
902 ph10 300 ---------------------
904 ph10 302 1. A character class containing a very large number of characters with
905     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
906     overflow.
907 ph10 309
908     2. Patch to cut out the "long long" test in pcrecpp_unittest when
909     HAVE_LONG_LONG is not defined.
911 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
912 ph10 304 bring them up to date and include new features. This patch includes:
913 ph10 309
914 ph10 304 - Fixed PH's badly added libz and libbz2 support.
915     - Fixed a problem with static linking.
916 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
917 ph10 304 - Fixed dftables problem and added an option.
918     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
920     - Added readline support for pcretest.
921 ph10 309 - Added an listing of the option settings after cmake has run.
923 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
924     "pcre.dll" under mingw when using Configure/Make. I added stuff to
925     Makefile.am that cause it to include this special target, without
926     affecting anything else. Note that the same mingw target plus all
927     the other distribution libraries and programs are now supported
928     when configuring with CMake (see 6 below) instead of with
929     Configure/Make.
930 ph10 309
931 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
932     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
933 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
934     solves the problem, but it does no harm.
935 ph10 313
936 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
937 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
938 ph10 314 with CMake, and also correct the comment about stack recursion.
939 ph10 313
940 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
941 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
942     of a program that users should build themselves after PCRE is installed, so
943     building it automatically is not really right. What is more, it gave
944 ph10 312 trouble in some build environments.
945 ph10 300
946 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
947 ph10 308
948 ph10 319
949 ph10 298 Version 7.5 10-Jan-08
950 ph10 263 ---------------------
952     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
953     values in parens when parsing an RE using the C++ wrapper."
954 ph10 286
955 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
956     Characters greater than 255 were excluded from the class instead of being
957     included.
958 ph10 286
959     3. The same bug as (2) above applied to negated POSIX classes such as
960 ph10 265 [:^space:].
961 ph10 286
962 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
963     defined or documented. It seems to have been a typo for PCRE_STATIC, so
964 ph10 286 I have changed it.
966 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
967 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
968     first named subpattern whose name started with "a" (in other words, the
969 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
970     expected" is now given for (?&) (a zero-length name), and this patch also
971     makes it give the same error for \k'' (previously it complained that that
972     was a reference to a non-existent subpattern).
973 ph10 286
974 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
975 ph10 286 this is right because (?- can be followed by option settings as well as by
976 ph10 269 digits. I have, however, made the messages clearer.
977 ph10 286
978 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
979     than the number used in the conditional) now cause a compile-time error.
980     This is actually not compatible with Perl, which accepts such patterns, but
981     treats the conditional as always being FALSE (as PCRE used to), but it
982     seems to me that giving a diagnostic is better.
983 ph10 286
984 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
985 ph10 275 and messages.
986 ph10 286
987     9. Fix two occurrences of "backslash" in comments that should have been
988     "backspace".
990     10. Remove two redundant lines of code that can never be obeyed (their function
991     was moved elsewhere).
993     11. The program that makes PCRE's Unicode character property table had a bug
994     which caused it to generate incorrect table entries for sequences of
995 ph10 277 characters that have the same character type, but are in different scripts.
996 ph10 286 It amalgamated them into a single range, with the script of the first of
997 ph10 277 them. In other words, some characters were in the wrong script. There were
998     thirteen such cases, affecting characters in the following ranges:
999 ph10 286
1000 ph10 277 U+002b0 - U+002c1
1001     U+0060c - U+0060d
1002 ph10 286 U+0061e - U+00612
1003 ph10 277 U+0064b - U+0065e
1004     U+0074d - U+0076d
1005     U+01800 - U+01805
1006     U+01d00 - U+01d77
1007     U+01d9b - U+01dbf
1008     U+0200b - U+0200f
1009     U+030fc - U+030fe
1010     U+03260 - U+0327f
1011     U+0fb46 - U+0fbb1
1012     U+10450 - U+1049d
1013 ph10 286
1014 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
1015     compatible with GNU grep in that, if there was more than one match in a
1016     line, it showed only the first of them. It now behaves in the same way as
1017     GNU grep.
1018 ph10 286
1019     13. If the -o and -v options were combined for pcregrep, it printed a blank
1020     line for every non-matching line. GNU grep prints nothing, and pcregrep now
1021     does the same. The return code can be used to tell if there were any
1022     non-matching lines.
1024 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
1026     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1027 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
1028 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
1029     and both kinds of lookbehind were skipped).
1031 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1032 ph10 284 inclusion of <windows.h> to before rather than after the definition of
1033     INVALID_FILE_ATTRIBUTES (patch from David Byron).
1034 ph10 263
1035 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
1036 ph10 286 character property caused pcre_compile() to compile bad code, which led at
1037     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1038     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1039     caused the error; without that there was no problem.
1040 ph10 263
1041 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1042 ph10 286
1043 ph10 289 19. Added --enable-pcretest-libreadline.
1044 ph10 286
1045 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1046 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
1047 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
1048     later patch that removed the other one (the right fix) and added unit tests
1049     that check the return values (which was not done before).
1050 ph10 292
1051 ph10 291 21. Several CMake things:
1052 ph10 287
1053 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1054 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
1055 ph10 288
1056 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
1057     linked with the newly-built libraries, not previously installed ones.
1058 ph10 291
1060 ph10 298
1061     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1062     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1063     UTF-8 newline character). The key issue is that the pattern starts .*;
1064     this means that the match must be either at the beginning, or after a
1065     newline. The bug was in the code for advancing after a failed match and
1066     checking that the new position followed a newline. It was not taking
1067 ph10 294 account of UTF-8 characters correctly.
1068 ph10 298
1069     23. PCRE was behaving differently from Perl in the way it recognized POSIX
1070     character classes. PCRE was not treating the sequence [:...:] as a
1071     character class unless the ... were all letters. Perl, however, seems to
1072     allow any characters between [: and :], though of course it rejects as
1073     unknown any "names" that contain non-letters, because all the known class
1074     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1075     for example, whereas PCRE did not - it did not recognize a POSIX character
1076     class. This seemed a bit dangerous, so the code has been changed to be
1077     closer to Perl. The behaviour is not identical to Perl, because PCRE will
1078     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1079     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1080     Perl does, and where it didn't before.
1082 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1083     Windows environments %n is disabled by default.
1084 ph10 292
1086 ph10 260 Version 7.4 21-Sep-07
1087 ph10 230 ---------------------
1089     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1090 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
1091     LF". That isn't really right - the whole point of the change was to try to
1092     help when there was an actual mention of one of the two characters. So now
1093     the change happens only if \r or \n (or a literal CR or LF) character is
1094 ph10 230 encountered.
1095 ph10 231
1096     2. The 32-bit options word was also used for 6 internal flags, but the numbers
1097     of both had grown to the point where there were only 3 bits left.
1098     Fortunately, there was spare space in the data structure, and so I have
1099     moved the internal flags into a new 16-bit field to free up more option
1100 ph10 230 bits.
1101 ph10 231
1102     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1103     but did not set the internal JCHANGED flag - either of these is enough to
1104     control the way the "get" function works - but the PCRE_INFO_JCHANGED
1105     facility is supposed to tell if (?J) was ever used, so now (?J) at the
1106 ph10 230 start sets both bits.
1108 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
1109     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1110 ph10 230
1111 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
1113     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1114 ph10 233 compatibility, even though it is no longer used.
1115 ph10 243
1116     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1117 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1118 ph10 259 windows.h file is present (where different names are used). [This was
1119 ph10 257 reversed later after testing - see 16 below.]
1120 ph10 243
1121     8. Changed all #include <config.h> to #include "config.h". There were also
1122 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
1123 ph10 243
1124 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
1125 ph10 243 sequence off the lines that it output.
1127     10. It was pointed out to me that arrays of string pointers cause lots of
1128     relocations when a shared library is dynamically loaded. A technique of
1129     using a single long string with a table of offsets can drastically reduce
1130     these. I have refactored PCRE in four places to do this. The result is
1131 ph10 240 dramatic:
1132 ph10 243
1133 ph10 240 Originally: 290
1134     After changing UCP table: 187
1135 ph10 243 After changing error message table: 43
1136 ph10 240 After changing table of "verbs" 36
1137     After changing table of Posix names 22
1138 ph10 243
1139 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
1140 ph10 247
1141 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1142 ph10 247 unicode-properties was also set.
1144 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1145 ph10 231
1146 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1147     checked only for CRLF.
1148 ph10 233
1149 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
1151 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1152 ph10 253
1153 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1154 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1155     entirely. This removes changes made in 7 above.
1156 ph10 256
1157 ph10 261 17. The CMake files have been updated, and there is now more information about
1158     building with CMake in the NON-UNIX-USE document.
1159 ph10 257
1160 ph10 261
1161 ph10 228 Version 7.3 28-Aug-07
1162 ph10 157 ---------------------
1164 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1165     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1166     brackets there is not right, since it causes compilers to look for an
1167     installed pcre.h, not the version that is in the source that is being
1168     compiled (which of course may be different). I have changed it back to:
1169 ph10 197
1170 ph10 189 #include "pcre.h"
1171 ph10 197
1172     I have a vague recollection that the change was concerned with compiling in
1173     different directories, but in the new build system, that is taken care of
1174     by the VPATH setting the Makefile.
1176 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1177     when the subject happened to end in the byte 0x85 (e.g. if the last
1178     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1179     characters but of course it shouldn't be taken as a newline when it is part
1180     of another character. The bug was that, for an unlimited repeat of . in
1181     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1182     characters when looking for a newline.
1183 ph10 197
1184     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1186     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1187     in debug output.
1189 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1190     long printing in the pcrecpp unittest when running under MinGW.
1191 ph10 189
1192 ph10 197 6. ESC_K was left out of the EBCDIC table.
1193 ph10 189
1194 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1195     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1196     limit also applies to "virtual nesting" when a pattern is recursive, and in
1197     this case 1000 isn't so big. I have been able to remove this limit at the
1198     expense of backing off one optimization in certain circumstances. Normally,
1199     when pcre_exec() would call its internal match() function recursively and
1200     immediately return the result unconditionally, it uses a "tail recursion"
1201     feature to save stack. However, when a subpattern that can match an empty
1202     string has an unlimited repetition quantifier, it no longer makes this
1203     optimization. That gives it a stack frame in which to save the data for
1204     checking that an empty string has been matched. Previously this was taken
1205     from the 1000-entry workspace that had been reserved. So now there is no
1206     explicit limit, but more stack is used.
1207 ph10 189
1208 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1209     syntax that is required for Windows, and which was going wrong for the
1210     pcreposix and pcrecpp parts of the library. These were overlooked when this
1211     problem was solved for the main library.
1212 ph10 197
1213 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1214     the size of patterns that contain repeated groups with explicit upper
1215     limits. As the maximum quantifier is 65535, the maximum group length was
1216     set at 30,000 so that the product of these two numbers did not overflow a
1217     32-bit integer. However, it turns out that people want to use groups that
1218     are longer than 30,000 bytes (though not repeat them that many times).
1219     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1220     made it possible to implement the integer overflow checks in a much more
1221     dynamic way, which I have now done. The artificial limitation on group
1222     length has been removed - we now have only the limit on the total length of
1223     the compiled pattern, which depends on the LINK_SIZE setting.
1224 ph10 208
1225     10. Fixed a bug in the documentation for get/copy named substring when
1226     duplicate names are permitted. If none of the named substrings are set, the
1227     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1228     empty string.
1230     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1231     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1232     because the ] is interpreted as the first data character and the
1233     terminating ] is not found. PCRE has been made compatible with Perl in this
1234     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1235     cause memory overwriting.
1237 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1238     string has been matched (to stop an infinite loop). It was not recognizing
1239 ph10 208 a conditional subpattern that could match an empty string if that
1240 ph10 206 subpattern was within another subpattern. For example, it looped when
1241 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1242 ph10 206 condition was not nested. This bug has been fixed.
1243 ph10 208
1244 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1245     past the start of the subject in the presence of bytes with the top bit
1246     set, for example "\x8aBCD".
1247 ph10 211
1248 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1249     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1250 ph10 200
1251 ph10 211 14. Optimized (?!) to (*FAIL).
1252 ph10 202
1253 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1254     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1255     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1256     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1257     does: it's just the validity check that is more restrictive.
1258 ph10 220
1259     16. Inserted checks for integer overflows during escape sequence (backslash)
1260     processing, and also fixed erroneous offset values for syntax errors during
1261     backslash processing.
1263 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1264 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1266 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1267     caused an overrun.
1268 ph10 220
1269     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1270     something other than just ASCII characters) inside a group that had an
1271     unlimited repeat caused a loop at compile time (while checking to see
1272     whether the group could match an empty string).
1274 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1275     [\P{Any}] did so. (Error in the code for printing property names.)
1276 ph10 210
1277 ph10 220 21. An orphan \E inside a character class could cause a crash.
1279     22. A repeated capturing bracket such as (A)? could cause a wild memory
1280 ph10 218 reference during compilation.
1281 ph10 220
1282     23. There are several functions in pcre_compile() that scan along a compiled
1283     expression for various reasons (e.g. to see if it's fixed length for look
1284 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1285 ph10 220 present in the pattern. These operators have additional parameters compared
1286     with \d, etc, and these were not being taken into account when moving along
1287 ph10 218 the compiled data. Specifically:
1288 ph10 220
1289     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1290     length.
1292     (b) An item such as \pL+ within a repeated group could cause crashes or
1293 ph10 218 loops.
1294 ph10 220
1295 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1296 ph10 220 "reference to non-existent subpattern" error.
1298 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1300 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1301 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1302 ph10 211
1303 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1304 ph10 218
1305 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1306 ph10 223 character were causing crashes (broken optimization).
1307 ph10 227
1308 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1309 ph10 227 \p or \P) caused a compile-time loop.
1311 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1312     break. For example, the unstudied pattern [\r\n]A does not match the string
1313     "\r\nA" because change 7.0/46 below moves the current point on by two
1314     characters after failing to match at the start. However, the pattern \nA
1315 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1316     the same is true. There doesn't seem any very clean way out of this, but
1317     what I have chosen to do makes the common cases work: PCRE now takes note
1318     of whether there can be an explicit match for \r or \n anywhere in the
1319     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1320     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1321     pattern has explicit CR or LF references.
1322 ph10 222
1323 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1324 ph10 223
1325 ph10 227
1326 ph10 189 Version 7.2 19-Jun-07
1327     ---------------------
1329 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1330     which is apparently normally available under Windows.
1331 ph10 159
1332     2. Re-jig the pcregrep tests with different newline settings in an attempt
1333     to make them independent of the local environment's newline setting.
1334 ph10 157
1335 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1336 ph10 165
1337 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1338     was not 2, because the output contained actual offsets. The recent new
1339 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1340     usable with all link sizes.
1342 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1343     stack recursion. This gives a massive performance boost under BSD, but just
1344 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1345 ph10 164 in all cases.
1346 ph10 172
1347 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1348 ph10 172
1349 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1350     recursion call. It refers to the nth most recently opened parentheses.
1351 ph10 172
1352 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1353 ph10 172 to be opened parentheses.
1355     (c) Conditions that refer to capturing parentheses can be specified
1356 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1357 ph10 172
1358 ph10 168 (d) \K resets the start of the current match so that everything before
1359 ph10 172 is not part of it.
1361 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1362 ph10 172
1363 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1364 ph10 172 reference syntax.
1365 ph10 182
1366 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1367 ph10 182 alternative starts with the same number.
1368 ph10 172
1369 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1371 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1374     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1375     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1376 ph10 170 for detecting groups that can match an empty string.
1377 ph10 159
1378 ph10 172 9. A pattern with a very large number of alternatives (more than several
1379     hundred) was running out of internal workspace during the pre-compile
1380     phase, where pcre_compile() figures out how much memory will be needed. A
1381     bit of new cunning has reduced the workspace needed for groups with
1382     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1383     workspace instead of running out of the 4096 that are available.
1384 ph10 182
1385 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1386 ph10 172
1387 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1388     The report of the bug said:
1389 ph10 182
1390 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1391     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1392 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1393 ph10 185
1394 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1395 ph10 185 it matched the wrong number of bytes.
1396 ph10 172
1397 ph10 179
1398 ph10 155 Version 7.1 24-Apr-07
1399 ph10 98 ---------------------
1401 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1402 ph10 122 that is more "standard", making use of automake and other Autotools. There
1403 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1404     on this.
1405 ph10 111
1406     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1407     for recursive directory scanning broke on some systems because the files
1408     are not scanned in any specific order and on different systems the order
1409     was different. A call to "sort" has been inserted into RunGrepTest for the
1410     approprate test as a short-term fix. In the longer term there may be an
1411 ph10 100 alternative.
1412 ph10 111
1413 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1414 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1415     people do their own conversions for various reasons). The problems
1416     concerned the use of low-level troff macros .br and .in. I have therefore
1417     removed all such uses from the man pages (some were redundant, some could
1418 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1419     HTML has been updated to handle .nf/.fi and to complain if it encounters
1420     .br or .in.
1421 ph10 111
1422 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1423 ph10 123 arranged for config.h to be included in the distribution, with the name
1424 ph10 111 config.h.generic, for the benefit of those who have to compile without
1425     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1427     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1428     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1429 ph10 127 makevp.bat for the current PCRE, using the additional files
1430 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1431 ph10 111
1432     6. A Windows user reported a minor discrepancy with test 2, which turned out
1433     to be caused by a trailing space on an input line that had got lost in his
1434 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1435 ph10 111
1436 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1437 ph10 111 that is needed.
1439 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1440     as "const" (a) because they are and (b) because it helps the PHP
1441     maintainers who have recently made a script to detect big data structures
1442 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1443     to update Builducptable as well, so it won't revert if ucptable.h is ever
1444 ph10 105 re-created.
1445 ph10 111
1446     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1447 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1448 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1449     support is not required. This saves 1.5-2K of code, which is important in
1450 ph10 107 some applications.
1451 ph10 111
1452 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1453 ph10 111 so as not to refer to the tables, even though these functions will never be
1454     called when UTF-8 support is disabled. Otherwise there are problems with a
1455     shared library.
1457 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1459     (a) It was defining its arguments as char * instead of void *.
1461 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1462     a long time ago when I wrote it, but is no longer the case.
1464 ph10 118 The emulated memove() is provided for those environments that have neither
1465 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1466 ph10 118 is clearly not the case, as these two bugs were recently reported.
1467 ph10 123
1468 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1469 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1470     pages, and it removes trailing spaces from listed files. It also creates
1471     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1472     case, it wraps all the #defines with #ifndefs. This script should be run
1473 ph10 111 before "make dist".
1474 ph10 123
1475 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1476     with Unicode property support.
1477 ph10 123
1478     (a) For a maximizing quantifier, if the two different cases of the
1479     character were of different lengths in their UTF-8 codings (there are
1480     some cases like this - I found 11), and the matching function had to
1481 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1482     were both the same length.
1483 ph10 123
1484     (b) When PCRE was configured to use the heap rather than the stack for
1485     recursion during matching, it was not correctly preserving the data for
1486     the other case of a UTF-8 character when checking ahead for a match
1487     while processing a minimizing repeat. If the check also involved
1488 ph10 115 matching a wide character, but failed, corruption could cause an
1489     erroneous result when trying to check for a repeat of the original
1490     character.
1491 ph10 123
1492 ph10 116 13. Some tidying changes to the testing mechanism:
1493 ph10 98
1494 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1495     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1496 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1497     this for UTF-8.) The configure.ac script no longer substitutes the
1498     relevant variables.
1500 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1501     with length and offset values. This means that the output is different
1502     for different internal link sizes. Test 2 is skipped for link sizes
1503     other than 2 because of this, bypassing the problem. Unfortunately,
1504     there was also a test in test 3 (the locale tests) that used /B and
1505 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1506     I have added a new /Z option to pcretest that replaces the length and
1507     offset values with spaces. This is now used to make test 3 independent
1508 ph10 122 of link size. (Test 2 will be tidied up later.)
1509 ph10 123
1510     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1511 ph10 122 segmentation fault instead of returning the appropriate error message.
1512 ph10 134
1513 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1514 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1515     This doesn't seem right; it now treats the CRLF combination as the line
1516     ending, and so does not match in that case. It's only a pattern such as ^$
1517     that would hit this one: something like ^ABC$ would have failed after \r
1518     and then tried again after \r\n.
1520 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1521 ph10 134 in an attempt to make files that differ only in their line terminators
1522     compare equal. This works on Linux.
1523 ph10 142
1524 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1525     as it exited. This is now fixed, thanks to valgrind.
1526 ph10 142
1527 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1528 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1529     was because its rules for how to advance for /g after matching an empty
1530 ph10 143 string at the end of a line did not allow for this case. They now check for
1531     it specially.
1532 ph10 150
1533     20. pcretest is supposed to handle patterns and data of any length, by
1534     extending its buffers when necessary. It was getting this wrong when the
1535 ph10 147 buffer for a data line had to be extended.
1536 ph10 150
1537 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1538 ph10 150 CRLF as a newline sequence.
1539 ph10 152
1540 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1541 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1542     I have nevertheless tidied it up.
1543 ph10 111
1544 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1545 ph10 123
1546 ph10 153 24. Added a man page for pcre-config.
1547 ph10 152
1548 ph10 153
1549 nigel 93 Version 7.0 19-Dec-06
1550     ---------------------
1552     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1553     moving to gcc 4.1.1.
1555     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1556     sys/time.h, which is documented as needed for this function. It doesn't
1557     seem to matter on Linux, but it showed up on some releases of OS X.
1559     3. It seems that there are systems where bytes whose values are greater than
1560     127 match isprint() in the "C" locale. The "C" locale should be the
1561     default when a C program starts up. In most systems, only ASCII printing
1562     characters match isprint(). This difference caused the output from pcretest
1563     to vary, making some of the tests fail. I have changed pcretest so that:
1565     (a) When it is outputting text in the compiled version of a pattern, bytes
1566     other than 32-126 are always shown as hex escapes.
1568     (b) When it is outputting text that is a matched part of a subject string,
1569     it does the same, unless a different locale has been set for the match
1570     (using the /L modifier). In this case, it uses isprint() to decide.
1572     4. Fixed a major bug that caused incorrect computation of the amount of memory
1573     required for a compiled pattern when options that changed within the
1574     pattern affected the logic of the preliminary scan that determines the
1575     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1576     that the computed length was too small. The symptoms of this bug were
1577     either the PCRE error "internal error: code overflow" from pcre_compile(),
1578     or a glibc crash with a message such as "pcretest: free(): invalid next
1579     size (fast)". Examples of patterns that provoked this bug (shown in
1580     pcretest format) are:
1582     /(?-x: )/x
1583     /(?x)(?-x: \s*#\s*)/
1584     /((?i)[\x{c0}])/8
1585     /(?i:[\x{c0}])/8
1587     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1588     is now done differently.
1590     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1591     wrapper classes; (b) implement a new function in the C++ scanner that is
1592     more efficient than the old way of doing things because it avoids levels of
1593     recursion in the regex matching; (c) add a paragraph to the documentation
1594     for the FullMatch() function.
1596     6. The escape sequence \n was being treated as whatever was defined as
1597     "newline". Not only was this contrary to the documentation, which states
1598     that \n is character 10 (hex 0A), but it also went horribly wrong when
1599     "newline" was defined as CRLF. This has been fixed.
1601     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1602     was being set to -1 for the "end of line" case (supposedly a value that no
1603     character can have). Though this value is never used (the check for end of
1604     line is "zero bytes in current character"), it caused compiler complaints.
1605     I've changed it to 0xffffffff.
1607     8. In pcre_version.c, the version string was being built by a sequence of
1608     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1609     string (as it is for production releases) called a macro with an empty
1610     argument. The C standard says the result of this is undefined. The gcc
1611     compiler treats it as an empty string (which was what was wanted) but it is
1612     reported that Visual C gives an error. The source has been hacked around to
1613     avoid this problem.
1615     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1616     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1617     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1618     of them did).
1620     10. Originally, pcretest opened its input and output without "b"; then I was
1621     told that "b" was needed in some environments, so it was added for release
1622     5.0 to both the input and output. (It makes no difference on Unix-like
1623     systems.) Later I was told that it is wrong for the input on Windows. I've
1624     now abstracted the modes into two macros, to make it easier to fiddle with
1625     them, and removed "b" from the input mode under Windows.
1627     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1629     12. Added -help and --help to pcretest as an official way of being reminded
1630     of the options.
1632     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1633     and pcrecpp.cc because they annoy compilers at high warning levels.
1635     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1637     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1638     scripts are not C programs :-) and which was not noticed because it works
1639     on Linux.
1641     16. pcretest is supposed to handle any length of pattern and data line (as one
1642     line or as a continued sequence of lines) by extending its input buffer if
1643     necessary. This feature was broken for very long pattern lines, leading to
1644     a string of junk being passed to pcre_compile() if the pattern was longer
1645     than about 50K.
1647     17. I have done a major re-factoring of the way pcre_compile() computes the
1648     amount of memory needed for a compiled pattern. Previously, there was code
1649     that made a preliminary scan of the pattern in order to do this. That was
1650     OK when PCRE was new, but as the facilities have expanded, it has become
1651     harder and harder to keep it in step with the real compile phase, and there
1652     have been a number of bugs (see for example, 4 above). I have now found a
1653     cunning way of running the real compile function in a "fake" mode that
1654     enables it to compute how much memory it would need, while actually only
1655     ever using a few hundred bytes of working memory and without too many
1656     tests of the mode. This should make future maintenance and development
1657     easier. A side effect of this work is that the limit of 200 on the nesting
1658     depth of parentheses has been removed (though this was never a serious
1659     limitation, I suspect). However, there is a downside: pcre_compile() now
1660     runs more slowly than before (30% or more, depending on the pattern). I
1661     hope this isn't a big issue. There is no effect on runtime performance.
1663     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1664     newline (only possible for the last line of a file) and it was a
1665     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1667     19. Added additional timing features to pcretest. (1) The -tm option now times
1668     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1669     separate command line item, by a number that specifies the number of
1670     repeats to use when timing. The default is 50000; this gives better
1671     precision, but takes uncomfortably long for very large patterns.
1673     20. Extended pcre_study() to be more clever in cases where a branch of a
1674     subpattern has no definite first character. For example, (a*|b*)[cd] would
1675     previously give no result from pcre_study(). Now it recognizes that the
1676     first character must be a, b, c, or d.
1678     21. There was an incorrect error "recursive call could loop indefinitely" if
1679     a subpattern (or the entire pattern) that was being tested for matching an
1680     empty string contained only one non-empty item after a nested subpattern.
1681     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1682     incorrectly, because the \d was being skipped in the check.
1684     22. The pcretest program now has a new pattern option /B and a command line
1685     option -b, which is equivalent to adding /B to every pattern. This causes
1686     it to show the compiled bytecode, without the additional information that
1687     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1688     is the same as /B/I).
1690     23. A new optimization is now able automatically to treat some sequences such
1691     as a*b as a*+b. More specifically, if something simple (such as a character
1692     or a simple class like \d) has an unlimited quantifier, and is followed by
1693     something that cannot possibly match the quantified thing, the quantifier
1694     is automatically "possessified".
1696     24. A recursive reference to a subpattern whose number was greater than 39
1697     went wrong under certain circumstances in UTF-8 mode. This bug could also
1698     have affected the operation of pcre_study().
1700     25. Realized that a little bit of performance could be had by replacing
1701     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1703     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1705     27. Possessive quantifiers such as a++ were previously implemented by turning
1706     them into atomic groups such as ($>a+). Now they have their own opcodes,
1707     which improves performance. This includes the automatically created ones
1708     from 23 above.
1710     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1711     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1712     the first matched character to be a colon. This applied both to named and
1713     numbered groups.
1715     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1717     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1718     building PCRE on Windows easier, so I have included it in the distribution.
1720     31. There is now a check in pcretest against a ridiculously large number being
1721     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1722     loop, the loop is abandoned.
1724     32. Forward references to subpatterns in conditions such as (?(2)...) where
1725     subpattern 2 is defined later cause pcre_compile() to search forwards in
1726     the pattern for the relevant set of parentheses. This search went wrong
1727     when there were unescaped parentheses in a character class, parentheses
1728     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1730     33. "Subroutine" calls and backreferences were previously restricted to
1731     referencing subpatterns earlier in the regex. This restriction has now
1732     been removed.
1734     34. Added a number of extra features that are going to be in Perl 5.10. On the
1735     whole, these are just syntactic alternatives for features that PCRE had
1736     previously implemented using the Python syntax or my own invention. The
1737     other formats are all retained for compatibility.
1739     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1740     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1741     also .NET compatible.
1743     (b) A recursion or subroutine call to a named group can now be defined as
1744     (?&name) as well as (?P>name).
1746     (c) A backreference to a named group can now be defined as \k<name> or
1747     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1748     5.10, are also .NET compatible.
1750     (d) A conditional reference to a named group can now use the syntax
1751     (?(<name>) or (?('name') as well as (?(name).
1753     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1754     groups (named and numbered) that are never evaluated inline, but can be
1755     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1756     is always false. There may be only one alternative in such a group.
1758     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1759     as the simple (?(R). The condition is true only if the most recent
1760     recursion is that of the given number or name. It does not search out
1761     through the entire recursion stack.
1763     (g) The escape \gN or \g{N} has been added, where N is a positive or
1764     negative number, specifying an absolute or relative reference.
1766     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1767     some "unreachable code" warnings.
1769     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1770     things, this adds five new scripts.
1772     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1773     There were also incompatibilities regarding the handling of \Q..\E inside
1774     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1775     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1777     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1778     matches an empty string, and forcibly breaks the loop. There were bugs in
1779     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1780     against aaaa the result was just "a" rather than "aaaa", for example. Two
1781     separate and independent bugs (that affected different cases) have been
1782     fixed.
1784     39. Refactored the code to abolish the use of different opcodes for small
1785     capturing bracket numbers. This is a tidy that I avoided doing when I
1786     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1787     The new approach is not only tidier, it makes it possible to reduce the
1788     memory needed to fix the previous bug (38).
1790     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1791     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1792     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1793     mode.
1795     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1796     report.
1798     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1799     copy construction and assignment in the C++ wrapper.
1801     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1802     couple of bugs that could have given wrong results in the "--newline=crlf"
1803     case.
1805     44. Added a number of casts and did some reorganization of signed/unsigned int
1806     variables following suggestions from Dair Grant. Also renamed the variable
1807     "this" as "item" because it is a C++ keyword.
1809     45. Arranged for dftables to add
1811     #include "pcre_internal.h"
1813     to pcre_chartables.c because without it, gcc 4.x may remove the array
1814     definition from the final binary if PCRE is built into a static library and
1815     dead code stripping is activated.
1817     46. For an unanchored pattern, if a match attempt fails at the start of a
1818     newline sequence, and the newline setting is CRLF or ANY, and the next two
1819     characters are CRLF, advance by two characters instead of one.
1822 nigel 91 Version 6.7 04-Jul-06
1823     ---------------------
1825     1. In order to handle tests when input lines are enormously long, pcretest has
1826     been re-factored so that it automatically extends its buffers when
1827     necessary. The code is crude, but this _is_ just a test program. The
1828     default size has been increased from 32K to 50K.
1830     2. The code in pcre_study() was using the value of the re argument before
1831     testing it for NULL. (Of course, in any sensible call of the function, it
1832     won't be NULL.)
1834     3. The memmove() emulation function in pcre_internal.h, which is used on
1835     systems that lack both memmove() and bcopy() - that is, hardly ever -
1836     was missing a "static" storage class specifier.
1838     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1839     containing an extended class (one that cannot be represented by a bitmap
1840     because it contains high-valued characters or Unicode property items, e.g.
1841     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1842     pattern, but PCRE should not loop if you do not (it no longer does).
1843     [Detail: two cases were found: (a) a repeated subpattern containing an
1844     extended class; (b) a recursive reference to a subpattern that followed a
1845     previous extended class. It wasn't skipping over the extended class
1846     correctly when UTF-8 mode was not set.]
1848     5. A negated single-character class was not being recognized as fixed-length
1849     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1850     compile error "lookbehind assertion is not fixed length".
1852     6. The RunPerlTest auxiliary script was showing an unexpected difference
1853     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1854     write a Perl script that can interpret lines of an input file either as
1855     byte characters or as UTF-8, which is what "perltest" was being required to
1856     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1857     can't do is switch easily at run time between having the "use utf8;" pragma
1858     or not. In the end, I fudged it by using the RunPerlTest script to insert
1859     "use utf8;" explicitly for the UTF-8 tests.
1861     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1862     the end of the subject string, contrary to the documentation and to what
1863     Perl does. This was true of both matching functions. Now it matches only at
1864     the start of the subject and immediately after *internal* newlines.
1866     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1867     a pointer to an int instead of a pointer to an unsigned long int. This
1868     caused problems on 64-bit systems.
1870     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1871     instance of the 'standard' template library not being so standard".
1873     10. There was no check on the number of named subpatterns nor the maximum
1874     length of a subpattern name. The product of these values is used to compute
1875     the size of the memory block for a compiled pattern. By supplying a very
1876     long subpattern name and a large number of named subpatterns, the size
1877     computation could be caused to overflow. This is now prevented by limiting
1878     the length of names to 32 characters, and the number of named subpatterns
1879     to 10,000.
1881     11. Subpatterns that are repeated with specific counts have to be replicated in
1882     the compiled pattern. The size of memory for this was computed from the
1883     length of the subpattern and the repeat count. The latter is limited to
1884     65535, but there was no limit on the former, meaning that integer overflow
1885     could in principle occur. The compiled length of a repeated subpattern is
1886     now limited to 30,000 bytes in order to prevent this.
1888     12. Added the optional facility to have named substrings with the same name.
1890     13. Added the ability to use a named substring as a condition, using the
1891     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1892     are numbers (not recommended). Forward references are permitted.
1894     14. Added forward references in named backreferences (if you see what I mean).
1896     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1897     pattern could run off the end of the subject. For example, the pattern
1898     "(?s)(.{1,5})"8 did this with the subject "ab".
1900     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1901     PCRE_CASELESS was set when matching characters that were quantified with ?
1902     or *.
1904     17. A character class other than a single negated character that had a minimum
1905     but no maximum quantifier - for example [ab]{6,} - was not handled
1906     correctly by pce_dfa_exec(). It would match only one character.
1908     18. A valid (though odd) pattern that looked like a POSIX character
1909     class but used an invalid character after [ (for example [[,abc,]]) caused
1910     pcre_compile() to give the error "Failed: internal error: code overflow" or
1911     in some cases to crash with a glibc free() error. This could even happen if
1912     the pattern terminated after [[ but there just happened to be a sequence of
1913     letters, a binary zero, and a closing ] in the memory that followed.
1915     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1916     over the years. Originally (before any Unicode support), just the bottom 8
1917     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1918     output from "man perlunicode" includes this:
1920     The regular expression compiler produces polymorphic opcodes. That
1921     is, the pattern adapts to the data and automatically switches to
1922     the Unicode character scheme when presented with Unicode data--or
1923     instead uses a traditional byte scheme when presented with byte
1924     data.
1926     Sadly, a wide octal escape does not cause a switch, and in a string with
1927     no other multibyte characters, these octal escapes are treated as before.
1928     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1929     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1930     Unicode string.
1932     I have not perpetrated such confusion in PCRE. Up till now, it took just
1933     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1934     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1935     translate to the appropriate multibyte character.
1937     29. Applied some refactoring to reduce the number of warnings from Microsoft
1938     and Borland compilers. This has included removing the fudge introduced
1939     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1940     a warning about an unused variable.
1942     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1943     characters since release 4.0, because Perl (from release 5.004) does not.
1944     [Or at least, is documented not to: some releases seem to be in conflict
1945     with the documentation.] However, when a pattern was studied with
1946     pcre_study() and all its branches started with \s, PCRE still included VT
1947     as a possible starting character. Of course, this did no harm; it just
1948     caused an unnecessary match attempt.
1950     22. Removed a now-redundant internal flag bit that recorded the fact that case
1951     dependency changed within the pattern. This was once needed for "required
1952     byte" processing, but is no longer used. This recovers a now-scarce options
1953     bit. Also moved the least significant internal flag bit to the most-
1954     significant bit of the word, which was not previously used (hangover from
1955     the days when it was an int rather than a uint) to free up another bit for
1956     the future.
1958     23. Added support for CRLF line endings as well as CR and LF. As well as the
1959     default being selectable at build time, it can now be changed at runtime
1960     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1961     specify that it is scanning data with non-default line endings.
1963     24. Changed the definition of CXXLINK to make it agree with the definition of
1964     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1966     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1967     recursions. This makes a big different to stack usage for some patterns.
1969     26. If a subpattern containing a named recursion or subroutine reference such
1970     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1971     the space required for the compiled pattern went wrong and gave too small a
1972     value. Depending on the environment, this could lead to "Failed: internal
1973     error: code overflow at offset 49" or "glibc detected double free or
1974     corruption" errors.
1976     27. Applied patches from Google (a) to support the new newline modes and (b) to
1977     advance over multibyte UTF-8 characters in GlobalReplace.
1979     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1980     difference for some implementation of PCRE in some Windows version.
1982     29. Added some extra testing facilities to pcretest:
1984     \q<number> in a data line sets the "match limit" value
1985     \Q<number> in a data line sets the "match recursion limt" value
1986     -S <number> sets the stack size, where <number> is in megabytes
1988     The -S option isn't available for Windows.
1991 nigel 89 Version 6.6 06-Feb-06
1992     ---------------------
1994     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1995     in pcreposix.h. I have copied the definition from pcre.h.
1997     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1998     because pcre.h is no longer a built file.
2000     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2001     not normally included in the compiled code.
2004 nigel 87 Version 6.5 01-Feb-06
2005     ---------------------
2007     1. When using the partial match feature with pcre_dfa_exec(), it was not
2008     anchoring the second and subsequent partial matches at the new starting
2009     point. This could lead to incorrect results. For example, with the pattern
2010     /1234/, partially matching against "123" and then "a4" gave a match.
2012     2. Changes to pcregrep:
2014     (a) All non-match returns from pcre_exec() were being treated as failures
2015     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2016     error message is output. Some extra information is given for the
2018     probably the only errors that are likely to be caused by users (by
2019     specifying a regex that has nested indefinite repeats, for instance).
2020     If there are more than 20 of these errors, pcregrep is abandoned.
2022     (b) A binary zero was treated as data while matching, but terminated the
2023     output line if it was written out. This has been fixed: binary zeroes
2024     are now no different to any other data bytes.
2026     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2027     used to set a locale for matching. The --locale=xxxx long option has
2028     been added (no short equivalent) to specify a locale explicitly on the
2029     pcregrep command, overriding the environment variables.
2031     (d) When -B was used with -n, some line numbers in the output were one less
2032     than they should have been.
2034     (e) Added the -o (--only-matching) option.
2036     (f) If -A or -C was used with -c (count only), some lines of context were
2037     accidentally printed for the final match.
2039     (g) Added the -H (--with-filename) option.
2041     (h) The combination of options -rh failed to suppress file names for files
2042     that were found from directory arguments.
2044     (i) Added the -D (--devices) and -d (--directories) options.
2046     (j) Added the -F (--fixed-strings) option.
2048     (k) Allow "-" to be used as a file name for -f as well as for a data file.
2050     (l) Added the --colo(u)r option.
2052     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2053     is not present by default.
2055     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2056     items such as (?R) or (?1), when the recursion could match a number of
2057     alternatives. If it matched one of the alternatives, but subsequently,
2058     outside the recursion, there was a failure, the code tried to back up into
2059     the recursion. However, because of the way PCRE is implemented, this is not
2060     possible, and the result was an incorrect result from the match.
2062     In order to prevent this happening, the specification of recursion has
2063     been changed so that all such subpatterns are automatically treated as
2064     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2066     4. I had overlooked the fact that, in some locales, there are characters for
2067     which isalpha() is true but neither isupper() nor islower() are true. In
2068     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2069     and ordfeminine) are like this. This affected the treatment of \w and \W
2070     when they appeared in character classes, but not when they appeared outside
2071     a character class. The bit map for "word" characters is now created
2072     separately from the results of isalnum() instead of just taking it from the
2073     upper, lower, and digit maps. (Plus the underscore character, of course.)
2075     5. The above bug also affected the handling of POSIX character classes such as
2076     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2077     permanent tables. Instead, the bit maps for such a class were previously
2078     created as the appropriate unions of the upper, lower, and digit bitmaps.
2079     Now they are created by subtraction from the [[:word:]] class, which has
2080     its own bitmap.
2082     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2083     It is created by subtracting the vertical space characters (\x09, \x0a,
2084     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2085     subtraction was done in the overall bitmap for a character class, meaning
2086     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2087     be recognized. This bug has been fixed.
2089     7. Patches from the folks at Google:
2091     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2092     real life, but is still worth protecting against".
2094     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2095     regular expressions".
2097     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2098     have it.
2100     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2101     "configure" and the latter not, in order to fix a problem somebody had
2102     with compiling the Arg class on HP-UX.
2104     (e) Improve the error-handling of the C++ wrapper a little bit.
2106     (f) New tests for checking recursion limiting.
2108     8. The pcre_memmove() function, which is used only if the environment does not
2109     have a standard memmove() function (and is therefore rarely compiled),
2110     contained two bugs: (a) use of int instead of size_t, and (b) it was not
2111     returning a result (though PCRE never actually uses the result).
2113     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2114     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2115     returned instead of calling malloc() with an overflowing number that would
2116     most likely cause subsequent chaos.
2118     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2120     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2121     with this option is matched, the nmatch and pmatch options of regexec() are
2122     ignored.
2124     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2125     provided in case anyone wants to the the POSIX interface with UTF-8
2126     strings.
2128     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2129     C++ linking (needed for some HP-UX environments).
2131     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2132     (unused parameter) and in the pcre_printint() function (omitted "default"
2133     switch label when the default is to do nothing).
2135     15. Added some code to make it possible, when PCRE is compiled as a C++
2136     library, to replace subject pointers for pcre_exec() with a smart pointer
2137     class, thus making it possible to process discontinuous strings.
2139     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2140     much the same function. They were added by different people who were trying
2141     to make PCRE easy to compile on non-Unix systems. It has been suggested
2142     that PCRE_EXPORT be abolished now that there is more automatic apparatus
2143     for compiling on Windows systems. I have therefore replaced it with
2144     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2145     defaults to "extern" for C or "extern C" for C++, which works fine on
2146     Unix-like systems. It is now possible to override the value of PCRE_DATA_
2147     SCOPE with something explicit in config.h. In addition:
2149     (a) pcreposix.h still had just "extern" instead of either of these macros;
2150     I have replaced it with PCRE_DATA_SCOPE.
2152     (b) Functions such as _pcre_xclass(), which are internal to the library,
2153     but external in the C sense, all had PCRE_EXPORT in their definitions.
2154     This is apparently wrong for the Windows case, so I have removed it.
2155     (It makes no difference on Unix-like systems.)
2157     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2158     of recursive calls to match(). This is different to MATCH_LIMIT because
2159     that limits the total number of calls to match(), not all of which increase
2160     the depth of recursion. Limiting the recursion depth limits the amount of
2161     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2162     when PCRE is compiled, and changed at run time. A patch from Google adds
2163     this functionality to the C++ interface.
2165     18. Changes to the handling of Unicode character properties:
2167     (a) Updated the table to Unicode 4.1.0.
2169     (b) Recognize characters that are not in the table as "Cn" (undefined).
2171     (c) I revised the way the table is implemented to a much improved format
2172     which includes recognition of ranges. It now supports the ranges that
2173     are defined in UnicodeData.txt, and it also amalgamates other
2174     characters into ranges. This has reduced the number of entries in the
2175     table from around 16,000 to around 3,000, thus reducing its size
2176     considerably. I realized I did not need to use a tree structure after
2177     all - a binary chop search is just as efficient. Having reduced the
2178     number of entries, I extended their size from 6 bytes to 8 bytes to
2179     allow for more data.
2181     (d) Added support for Unicode script names via properties such as \p{Han}.
2183     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2184     matching that character.
2186     20. When matching a repeated Unicode property with a minimum greater than zero,
2187     (for example \pL{2,}), PCRE could look past the end of the subject if it
2188     reached it while seeking the minimum number of characters. This could
2189     happen only if some of the characters were more than one byte long, because
2190     there is a check for at least the minimum number of bytes.
2192     21. Refactored the implementation of \p and \P so as to be more general, to
2193     allow for more different types of property in future. This has changed the
2194     compiled form incompatibly. Anybody with saved compiled patterns that use
2195     \p or \P will have to recompile them.
2197     22. Added "Any" and "L&" to the supported property types.
2199     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2200     but give a compile time error if the value is greater than 0xff.
2202     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2203     accidentally not being installed or uninstalled.
2205     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2206     made were to insert the current release number. This seemed silly, because
2207     it made things harder for people building PCRE on systems that don't run
2208     "configure". I have turned pcre.h into a distributed file, no longer built
2209     by "configure", with the version identification directly included. There is
2210     no longer a pcre.h.in file.
2212     However, this change necessitated a change to the pcre-config script as
2213     well. It is built from pcre-config.in, and one of the substitutions was the
2214     release number. I have updated configure.ac so that ./configure now finds
2215     the release number by grepping pcre.h.
2217     26. Added the ability to run the tests under valgrind.
2220 nigel 85 Version 6.4 05-Sep-05
2221     ---------------------
2223     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2224     "--" to be printed when multiple files were scanned, even when none of the
2225     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2226     consider it to be a bug, and have restored the previous behaviour.
2228     2. A couple of code tidies to get rid of compiler warnings.
2230     3. The pcretest program used to cheat by referring to symbols in the library
2231     whose names begin with _pcre_. These are internal symbols that are not
2232     really supposed to be visible externally, and in some environments it is
2233     possible to suppress them. The cheating is now confined to including
2234     certain files from the library's source, which is a bit cleaner.
2236     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2237     file's purpose clearer.
2239     5. Reorganized pcre_ucp_findchar().
2242 nigel 83 Version 6.3 15-Aug-05
2243     ---------------------
2245     1. The file libpcre.pc.in did not have general read permission in the tarball.
2247     2. There were some problems when building without C++ support:
2249     (a) If C++ support was not built, "make install" and "make test" still
2250     tried to test it.
2252     (b) There were problems when the value of CXX was explicitly set. Some
2253     changes have been made to try to fix these, and ...
2255     (c) --disable-cpp can now be used to explicitly disable C++ support.
2257     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2258     backslash in a target when C++ was disabled. This confuses some
2259     versions of "make", apparently. Using an intermediate variable solves
2260     this. (Same for CPP_LOBJ.)
2262     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2263     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2264     necessary on certain architectures.
2266     4. Added a setting of -export-symbols-regex to the link command to remove
2267     those symbols that are exported in the C sense, but actually are local
2268     within the library, and not documented. Their names all begin with
2269     "_pcre_". This is not a perfect job, because (a) we have to except some
2270     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2271     available (and never for static libraries). I have made a note to try to
2272     find a way round (a) in the future.
2275 nigel 81 Version 6.2 01-Aug-05
2276     ---------------------
2278     1. There was no test for integer overflow of quantifier values. A construction
2279     such as {1111111111111111} would give undefined results. What is worse, if
2280     a minimum quantifier for a parenthesized subpattern overflowed and became
2281     negative, the calculation of the memory size went wrong. This could have
2282     led to memory overwriting.
2284     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2286     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2287     operating environments where this matters.
2289     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2290     PCRE options from within the C++ wrapper.
2292     5. Named capturing subpatterns were not being correctly counted when a pattern
2293     was compiled. This caused two problems: (a) If there were more than 100
2294     such subpatterns, the calculation of the memory needed for the whole
2295     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2296     back references of the form \12, where the number was greater than 9, were
2297     not recognized as back references, even though there were sufficient
2298     previous subpatterns.
2300     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2301     versions of gcc, e.g. 2.95.4.
2304 nigel 79 Version 6.1 21-Jun-05
2305     ---------------------
2307     1. There was one reference to the variable "posix" in pcretest.c that was not
2308     surrounded by "#if !defined NOPOSIX".
2310     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2311     the cross-check on the old pcre_info() function, for the benefit of the
2312     cut-down version of PCRE that is currently imported into Exim.
2314     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2315     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2316     patterns that start (?i) but I don't think that matters. The use of (?i) is
2317     just an example; this all applies to the other options as well.
2319     4. Since libtool seems to echo the compile commands it is issuing, the output
2320     from "make" can be reduced a bit by putting "@" in front of each libtool
2321     compile command.
2323     5. Patch from the folks at Google for configure.in to be a bit more thorough
2324     in checking for a suitable C++ installation before trying to compile the
2325     C++ stuff. This should fix a reported problem when a compiler was present,
2326     but no suitable headers.
2328     6. The man pages all had just "PCRE" as their title. I have changed them to
2329     be the relevant file name. I have also arranged that these names are
2330     retained in the file doc/pcre.txt, which is a concatenation in text format
2331     of all the man pages except the little individual ones for each function.
2333     7. The NON-UNIX-USE file had not been updated for the different set of source
2334     files that come with release 6. I also added a few comments about the C++
2335     wrapper.
2338 nigel 77 Version 6.0 07-Jun-05
2339     ---------------------
2341     1. Some minor internal re-organization to help with my DFA experiments.
2343     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2344     didn't matter for the library itself when fully configured, but did matter
2345     when compiling without UCP support, or within Exim, where the ucp files are
2346     not imported.
2348     3. Refactoring of the library code to split up the various functions into
2349     different source modules. The addition of the new DFA matching code (see
2350     below) to a single monolithic source would have made it really too
2351     unwieldy, quite apart from causing all the code to be include in a
2352     statically linked application, when only some functions are used. This is
2353     relevant even without the DFA addition now that patterns can be compiled in
2354     one application and matched in another.
2356     The downside of splitting up is that there have to be some external
2357     functions and data tables that are used internally in different modules of
2358     the library but which are not part of the API. These have all had their
2359     names changed to start with "_pcre_" so that they are unlikely to clash
2360     with other external names.
2362     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2363     a different (DFA) algorithm. Although it is slower than the original
2364     function, it does have some advantages for certain types of matching
2365     problem.
2367     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2368     including restarting after a partial match.
2370     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2371     defined when compiling for Windows was sent to me. I have put it into the
2372     code, though I have no means of testing or verifying it.
2374     7. Added the pcre_refcount() auxiliary function.
2376     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2377     match before or at the first newline in the subject string. In pcretest,
2378     the /f option on a pattern can be used to set this.
2380     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2381     would behave wrongly. This has been present in PCRE since release 4.0.
2383     10. A number of changes to the pcregrep command:
2385     (a) Refactored how -x works; insert ^(...)$ instead of setting
2386     PCRE_ANCHORED and checking the length, in preparation for adding
2387     something similar for -w.
2389     (b) Added the -w (match as a word) option.
2391     (c) Refactored the way lines are read and buffered so as to have more
2392     than one at a time available.
2394     (d) Implemented a pcregrep test script.
2396     (e) Added the -M (multiline match) option. This allows patterns to match
2397     over several lines of the subject. The buffering ensures that at least
2398     8K, or the rest of the document (whichever is the shorter) is available
2399     for matching (and similarly the previous 8K for lookbehind assertions).
2401     (f) Changed the --help output so that it now says
2403     -w, --word-regex(p)
2405     instead of two lines, one with "regex" and the other with "regexp"
2406     because that confused at least one person since the short forms are the
2407     same. (This required a bit of code, as the output is generated
2408     automatically from a table. It wasn't just a text change.)
2410     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2411     option but starts with a hyphen. Could be a pattern or a path name
2412     starting with a hyphen, for instance.
2414     (h) "-" can be given as a file name to represent stdin.
2416     (i) When file names are being printed, "(standard input)" is used for
2417     the standard input, for compatibility with GNU grep. Previously
2418     "<stdin>" was used.
2420     (j) The option --label=xxx can be used to supply a name to be used for
2421     stdin when file names are being printed. There is no short form.
2423     (k) Re-factored the options decoding logic because we are going to add
2424     two more options that take data. Such options can now be given in four
2425     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2427     (l) Added the -A, -B, and -C options for requesting that lines of context
2428     around matches be printed.
2430     (m) Added the -L option to print the names of files that do not contain
2431     any matching lines, that is, the complement of -l.
2433     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2434     continue to scan other files.
2436     (o) The -s option was incorrectly implemented. For compatibility with other
2437     greps, it now suppresses the error message for a non-existent or non-
2438     accessible file (but not the return code). There is a new option called
2439     -q that suppresses the output of matching lines, which was what -s was
2440     previously doing.
2442     (p) Added --include and --exclude options to specify files for inclusion
2443     and exclusion when recursing.
2445     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2446     Hopefully, it now does.
2448     12. Missing cast in pcre_study().
2450     13. Added an "uninstall" target to the makefile.
2452     14. Replaced "extern" in the function prototypes in Makefile.in with
2453     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2454     world, but is set differently for Windows.
2456     15. Added a second compiling function called pcre_compile2(). The only
2457     difference is that it has an extra argument, which is a pointer to an
2458     integer error code. When there is a compile-time failure, this is set
2459     non-zero, in addition to the error test pointer being set to point to an
2460     error message. The new argument may be NULL if no error number is required
2461     (but then you may as well call pcre_compile(), which is now just a
2462     wrapper). This facility is provided because some applications need a
2463     numeric error indication, but it has also enabled me to tidy up the way
2464     compile-time errors are handled in the POSIX wrapper.
2466     16. Added VPATH=.libs to the makefile; this should help when building with one
2467     prefix path and installing with another. (Or so I'm told by someone who
2468     knows more about this stuff than I do.)
2470     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2471     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2472     match everything, including newlines. This is not POSIX-compatible, but
2473     somebody wanted the feature. From pcretest it can be activated by using
2474     both the P and the s flags.
2476     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2478     19. libpcre.pc was being incorrectly installed as executable.
2480     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2481     it now also looks for '\r' so that it will work unmodified on Windows.
2483     21. Added Google's contributed C++ wrapper to the distribution.
2485     22. Added some untidy missing memory free() calls in pcretest, to keep
2486     Electric Fence happy when testing.
2490 nigel 75 Version 5.0 13-Sep-04
2491     ---------------------
2493     1. Internal change: literal characters are no longer packed up into items
2494     containing multiple characters in a single byte-string. Each character
2495     is now matched using a separate opcode. However, there may be more than one
2496     byte in the character in UTF-8 mode.
2498     2. The pcre_callout_block structure has two new fields: pattern_position and
2499     next_item_length. These contain the offset in the pattern to the next match
2500     item, and its length, respectively.
2502     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2503     insertion of callouts before each pattern item. Added the /C option to
2504     pcretest to make use of this.
2506     4. On the advice of a Windows user, the lines
2508     #if defined(_WIN32) || defined(WIN32)
2509     _setmode( _fileno( stdout ), 0x8000 );
2510     #endif /* defined(_WIN32) || defined(WIN32) */
2512     have been added to the source of pcretest. This apparently does useful
2513     magic in relation to line terminators.
2515     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2516     for the benefit of those environments where the "b" makes a difference.
2518     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2519     to know about it. I have put a hack into configure.in that adds in code
2520     to set GCC=yes if CC=icc. This seems to end up at a point in the
2521     generated configure script that is early enough to affect the setting of
2522     compiler options, which is what is needed, but I have no means of testing
2523     whether it really works. (The user who reported this had patched the
2524     generated configure script, which of course I cannot do.)
2526     LATER: After change 22 below (new libtool files), the configure script
2527     seems to know about icc (and also ecc). Therefore, I have commented out
2528     this hack in configure.in.
2530     7. Added support for pkg-config (2 patches were sent in).
2532     8. Negated POSIX character classes that used a combination of internal tables
2533     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2534     [[:^ascii]]. Typically, they would match almost any characters. The other
2535     POSIX classes were not broken in this way.
2537     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2538     to find the match, as PCRE was deluded into thinking that the match had to
2539     start at the start point or following a newline. The same bug applied to
2540     patterns with negative forward assertions or any backward assertions
2541     preceding ".*" at the start, unless the pattern required a fixed first
2542     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2544     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2545     starting at the last subject character, bytes beyond the end of the subject
2546     string were read.
2548     11. Renamed the variable "class" as "classbits" to make life easier for C++
2549     users. (Previously there was a macro definition, but it apparently wasn't
2550     enough.)
2552     12. Added the new field "tables" to the extra data so that tables can be passed
2553     in at exec time, or the internal tables can be re-selected. This allows
2554     a compiled regex to be saved and re-used at a later time by a different
2555     program that might have everything at different addresses.
2557     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2558     -R library as well as a -L library.
2560     14. The debugging options of pcretest (-d on the command line or D on a
2561     pattern) showed incorrect output for anything following an extended class
2562     that contained multibyte characters and which was followed by a quantifier.
2564     15. Added optional support for general category Unicode character properties
2565     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2566     support. It adds about 90K to the size of the library. The meanings of the
2567     inbuilt class escapes such as \d and \s have NOT been changed.
2569     16. Updated pcredemo.c to include calls to free() to release the memory for the
2570     compiled pattern.
2572     17. The generated file chartables.c was being created in the source directory
2573     instead of in the building directory. This caused the build to fail if the
2574     source directory was different from the building directory, and was
2575     read-only.
2577     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2578     file. No doubt somebody will tell me if they don't make sense... Also added
2579     Dan Mooney's comments about building on OpenVMS.
2581     19. Added support for partial matching via the PCRE_PARTIAL option for
2582     pcre_exec() and the \P data escape in pcretest.
2584     20. Extended pcretest with 3 new pattern features:
2586     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2587     write the compiled pattern to the file whose name is "rest-of-line".
2588     This is a straight binary dump of the data, with the saved pointer to
2589     the character tables forced to be NULL. The study data, if any, is
2590     written too. After writing, pcretest reads a new pattern.
2592     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2593     compiled pattern from the given file. There must not be any
2594     occurrences of "<" in the file name (pretty unlikely); if there are,
2595     pcretest will instead treat the initial "<" as a pattern delimiter.
2596     After reading in the pattern, pcretest goes on to read data lines as
2597     usual.
2599     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2600     and 16-bit fields in a compiled pattern, to simulate a pattern that
2601     was compiled on a host of opposite endianness.
2603     21. The pcre-exec() function can now cope with patterns that were compiled on
2604     hosts of opposite endianness, with this restriction:
2606     As for any compiled expression that is saved and used later, the tables
2607     pointer field cannot be preserved; the extra_data field in the arguments
2608     to pcre_exec() should be used to pass in a tables address if a value
2609     other than the default internal tables were used at compile time.
2611     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2612     now diagnosed as an error. Previously, most of the time, a negative number
2613     would have been treated as zero, but if in addition "ovector" was passed as
2614     NULL, a crash could occur.
2616     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2617     new versions from the libtool 1.5 distribution (the last one is a copy of
2618     a file called libtool.m4). This seems to have fixed the need to patch
2619     "configure" to support Darwin 1.3 (which I used to do). However, I still
2620     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2621     workstation).
2623     24. Changed the PCRE licence to be the more standard "BSD" licence.
2626 nigel 73 Version 4.5 01-Dec-03
2627     ---------------------
2629     1. There has been some re-arrangement of the code for the match() function so
2630     that it can be compiled in a version that does not call itself recursively.
2631     Instead, it keeps those local variables that need separate instances for
2632     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2633     needs to "recurse". Keeping track of where control must go is done by means
2634     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2635     hide most of the details from the main code, and operates only if
2636     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2637     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2638     operating.
2640     To make it easier for callers to provide specially tailored get/free
2641     functions for this usage, two new functions, pcre_stack_malloc, and
2642     pcre_stack_free, are used. They are always called in strict stacking order,
2643     and the size of block requested is always the same.
2645     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2646     PCRE has been compiled to use the stack or the heap for recursion. The
2647     -C option of pcretest uses this to show which version is compiled.
2649     A new data escape \S, is added to pcretest; it causes the amounts of store
2650     obtained and freed by both kinds of malloc/free at match time to be added
2651     to the output.
2653     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2654     what's available on my current Linux desktop machine.
2656     3. When matching a UTF-8 string, the test for a valid string at the start has
2657     been extended. If start_offset is not zero, PCRE now checks that it points
2658     to a byte that is the start of a UTF-8 character. If not, it returns
2659     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2660     this is necessary because there may be backward assertions in the pattern.
2661     When matching the same subject several times, it may save resources to use
2662     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2664     4. The code for checking the validity of UTF-8 strings has been tightened so
2665     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2666     containing "overlong sequences".
2668     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2669     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2670     should have been "&", but it just so happened that all the cases this let
2671     through by mistake were picked up later in the function.
2673     6. I had used a variable called "isblank" - this is a C99 function, causing
2674     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2676     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2677     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2678     so the version is shown; (c) stop "make test" echoing "./RunTest".
2680     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2682     9. The prototype for memmove() for systems that don't have it was using
2683     size_t, but the inclusion of the header that defines size_t was later. I've
2684     moved the #includes for the C headers earlier to avoid this.
2686     10. Added some adjustments to the code to make it easier to compiler on certain
2687     special systems:
2689     (a) Some "const" qualifiers were missing.
2690     (b) Added the macro EXPORT before all exported functions; by default this
2691     is defined to be empty.
2692     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2693     that it reads its output file name as an argument instead of writing
2694     to the standard output and assuming this can be redirected.
2696     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2697     class containing characters with values greater than 255, PCRE compilation
2698     went into a loop.
2700     12. A recursive reference to a subpattern that was within another subpattern
2701     that had a minimum quantifier of zero caused PCRE to crash. For example,
2702     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2703     recursion. If the recursively-called subpattern itself had a zero repeat,
2704     that was OK.
2706     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2707     buffer into which it was copied (for escape processing) was still set at
2708     1024, so long lines caused crashes.
2710     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2711     "internal error: code overflow...". This applied to any character class
2712     that was followed by a possessive quantifier.
2714     15. Modified the Makefile to add libpcre.la as a prerequisite for
2715     libpcreposix.la because I was told this is needed for a parallel build to
2716     work.
2718     16. If a pattern that contained .* following optional items at the start was
2719     studied, the wrong optimizing data was generated, leading to matching
2720     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2721     matching string must start with a or b or c. The correct conclusion for
2722     this pattern is that a match can start with any character.
2725 nigel 71 Version 4.4 13-Aug-03
2726     ---------------------
2728     1. In UTF-8 mode, a character class containing characters with values between
2729     127 and 255 was not handled correctly if the compiled pattern was studied.
2730     In fixing this, I have also improved the studying algorithm for such
2731     classes (slightly).
2733     2. Three internal functions had redundant arguments passed to them. Removal
2734     might give a very teeny performance improvement.
2736     3. Documentation bug: the value of the capture_top field in a callout is *one
2737     more than* the number of the hightest numbered captured substring.
2739     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2740     in incorrectly linking with a previously installed version. They now link
2741     explicitly with libpcre.la.
2743     5. configure.in no longer needs to recognize Cygwin specially.
2745     6. A problem in pcre.in for Windows platforms is fixed.
2747     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2748     pcretest, it used to include the size of the study block as part of its
2749     output. Unfortunately, the structure contains a field that has a different
2750     size on different hardware architectures. This meant that the tests that
2751     showed this size failed. As the block is currently always of a fixed size,
2752     this information isn't actually particularly useful in pcretest output, so
2753     I have just removed it.
2755     8. Three pre-processor statements accidentally did not start in column 1.
2756     Sadly, there are *still* compilers around that complain, even though
2757     standard C has not required this for well over a decade. Sigh.
2759     9. In pcretest, the code for checking callouts passed small integers in the
2760     callout_data field, which is a void * field. However, some picky compilers
2761     complained about the casts involved for this on 64-bit systems. Now
2762     pcretest passes the address of the small integer instead, which should get
2763     rid of the warnings.
2765     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2766     both compile and run time, and gives an error if an invalid UTF-8 sequence
2767     is found. There is a option for disabling this check in cases where the
2768     string is known to be correct and/or the maximum performance is wanted.
2770     11. In response to a bug report, I changed one line in Makefile.in from
2772     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2773     to
2774     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2776     to look similar to other lines, but I have no way of telling whether this
2777     is the right thing to do, as I do not use Windows. No doubt I'll get told
2778     if it's wrong...
2781 nigel 69 Version 4.3 21-May-03
2782     ---------------------
2784     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2785     Makefile.
2787     2. Some refactoring to improve the quality of the code:
2789     (i) The utf8_table... variables are now declared "const".
2791     (ii) The code for \cx, which used the "case flipping" table to upper case
2792     lower case letters, now just substracts 32. This is ASCII-specific,
2793     but the whole concept of \cx is ASCII-specific, so it seems
2794     reasonable.
2796     (iii) PCRE was using its character types table to recognize decimal and
2797     hexadecimal digits in the pattern. This is silly, because it handles
2798     only 0-9, a-f, and A-F, but the character types table is locale-
2799     specific, which means strange things might happen. A private
2800     table is now used for this - though it costs 256 bytes, a table is
2801     much faster than multiple explicit tests. Of course, the standard
2802     character types table is still used for matching digits in subject
2803     strings against \d.
2805     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2806     ending in _t are). So I've renamed it as ESC_tee.
2808     3. The first argument for regexec() in the POSIX wrapper should have been
2809     defined as "const".
2811     4. Changed pcretest to use malloc() for its buffers so that they can be
2812     Electric Fenced for debugging.
2814     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2815     to read one or more bytes before the start of the subject string. Often this
2816     had no effect on PCRE's behaviour, but in some circumstances it could
2817     provoke a segmentation fault.
2819     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2820     to try to read one or more bytes before the start of the subject string.
2822     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2823     UTF-8 support could misbehave in various ways if the subject string
2824     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2825     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2826     back over UTF-8 characters.)
2829 nigel 67 Version 4.2 14-Apr-03
2830     ---------------------
2832     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2834     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2835     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2836     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2837     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2838     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2839     and BUILD_EXEEXT
2840     Note: automatic setting of the BUILD variables is not yet working
2841     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2842     compile-time but not at link-time
2843     [LINK]: use for linking executables only
2844     make different versions for Windows and non-Windows
2845     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2846     libraries
2847     [LINK_FOR_BUILD]: new variable
2848     [OBJEXT]: use throughout
2849     [EXEEXT]: use throughout
2850     <winshared>: new target
2851     <wininstall>: new target
2852     <dftables.o>: use native compiler
2853     <dftables>: use native linker
2854     <install>: handle Windows platform correctly
2855     <clean>: ditto
2856     <check>: ditto
2857     copy DLL to top builddir before testing
2859     As part of these changes, -no-undefined was removed again. This was reported
2860     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2861     in any case.
2863     3. Some tidies to get rid of compiler warnings:
2865     . In the match_data structure, match_limit was an unsigned long int, whereas
2866     match_call_count was an int. I've made them both unsigned long ints.
2868     . In pcretest the fact that a const uschar * doesn't automatically cast to
2869     a void * provoked a warning.
2871     . Turning on some more compiler warnings threw up some "shadow" variables
2872     and a few more missing casts.
2874     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2875     option, a class that contained a single character with a value between 128
2876     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2878     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2879     option, a class that contained several characters, but with at least one
2880     whose value was between 128 and 255 caused PCRE to crash.
2883 nigel 65 Version 4.1 12-Mar-03
2884     ---------------------
2885 nigel 63
2886 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2887     needed, and a string in dftables.c that was longer than standard compilers are
2888     required to support.
2890     2. Compiling with Sun's compiler found a few more places where the code could
2891     be tidied up in order to avoid warnings.
2893     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2894     first of these names is deprecated in the latest Autoconf in favour of the name
2895     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2896     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2897     analogy I have changed it to CFLAGS_FOR_BUILD.
2899     4. Added -no-undefined to the linking command in the Makefile, because this is
2900     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2901     linking step for the pcreposix library.
2903     5. PCRE was failing to diagnose the case of two named groups with the same
2904     name.
2906     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2907     literal character that is needed in the subject for a match, and scans along to
2908     ensure that it is present before embarking on the full matching process. This
2909     saves time in cases of nested unlimited repeats that are never going to match.
2910     Problem: the scan can take a lot of time if the subject is very long (e.g.
2911     megabytes), thus penalizing straightforward matches. It is now done only if the
2912     amount of subject to be scanned is less than 1000 bytes.
2914     7. A lesser problem with the same optimization is that it was recording the
2915     first character of an anchored pattern as "needed", thus provoking a search
2916     right along the subject, even when the first match of the pattern was going to
2917     fail. The "needed" character is now not set for anchored patterns, unless it
2918     follows something in the pattern that is of non-fixed length. Thus, it still
2919     fulfils its original purpose of finding quick non-matches in cases of nested
2920     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2923     Version 4.0 17-Feb-03
2924     ---------------------
2926 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2927     extended to the end of string, PCRE compiled incorrect data. This could lead to
2928     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2930     2. Moved to autoconf 2.53 and libtool 1.4.2.
2932     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2933     the special perltest8 script is no longer needed - all the tests can be run
2934     from a single perltest script.
2936     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2937     by \s. It has now been removed in PCRE. This means it isn't recognized as
2938     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2939     class [:space:] *does* include VT, thereby creating a mess.
2941     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2942     space and tab.
2944     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2945     its new features into the main test script, reducing the number of scripts.
2947     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2948     were backward compatible, and made the (?i) apply to the whole pattern, as if
2949     /i were given. Now it behaves more logically, and applies the option setting
2950     only to what follows. PCRE has been changed to follow suit. However, if it
2951     finds options settings right at the start of the pattern, it extracts them into
2952     the global options, as before. Thus, they show up in the info data.
2954     8. Added support for the \Q...\E escape sequence. Characters in between are
2955     treated as literals. This is slightly different from Perl in that $ and @ are
2956     also handled as literals inside the quotes. In Perl, they will cause variable
2957     interpolation. Note the following examples:
2959     Pattern PCRE matches Perl matches
2961     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2962     \Qabc\$xyz\E abc\$xyz abc\$xyz
2963     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2965     For compatibility with Perl, \Q...\E sequences are recognized inside character
2966     classes as well as outside them.
2968     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2969     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2970     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2971     signed/unsigned warnings.
2973     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2974     option for pcretest, so I've replaced it by a simple function that does just
2975     that job.
2977     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2978     "pcregrep -".
2980     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2981     Java package. This provides some syntactic sugar for simple cases of what my
2982     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2983     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2984     item, you can use this simplified notation. Note that only makes sense with
2985     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2986     greediness, whatever the setting of the PCRE_UNGREEDY option.
2988     13. A change of greediness default within a pattern was not taking effect at
2989     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2990     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2991     was abstracted outside.
2993     14. PCRE now supports the \G assertion. It is true when the current matching
2994     position is at the start point of the match. This differs from \A when the
2995     starting offset is non-zero. Used with the /g option of pcretest (or similar
2996     code), it works in the same way as it does for Perl's /g option. If all
2997     alternatives of a regex begin with \G, the expression is anchored to the start
2998     match position, and the "anchored" flag is set in the compiled expression.
3000     15. Some bugs concerning the handling of certain option changes within patterns
3001     have been fixed. These applied to options other than (?ims). For example,
3002     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3003     been the other way round. Some of this was related to change 7 above.
3005     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3006     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3007     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3008     POSIX classes only within a class (e.g. /[[:alpha:]]/).
3010     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3011     mode. Unlike ".", it always matches newline, whatever the setting of
3012     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3013     assertions. Perl allows it, but it doesn't (in general) work because it can't
3014     calculate the length of the lookbehind. At least, that's the case for Perl
3015     5.8.0 - I've been told they are going to document that it doesn't work in
3016     future.
3018     18. Added an error diagnosis for escapes that PCRE does not support: these are
3019     \L, \l, \N, \P, \p, \U, \u, and \X.
3021     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3022     reading past the end of the pattern in cases such as /[abcd/.
3024     20. PCRE was getting more memory than necessary for patterns with classes that
3025     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3027     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3028     compiling PCRE for use with Virtual Pascal.
3030     22. Small fix to the Makefile to make it work properly if the build is done
3031     outside the source tree.
3033     23. Added a new extension: a condition to go with recursion. If a conditional
3034     subpattern starts with (?(R) the "true" branch is used if recursion has
3035     happened, whereas the "false" branch is used only at the top level.
3037     24. When there was a very long string of literal characters (over 255 bytes
3038     without UTF support, over 250 bytes with UTF support), the computation of how
3039     much memory was required could be incorrect, leading to segfaults or other
3040     strange effects.
3042     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3043     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3044     there was a subsequent back reference to those brackets. This meant that, for
3045     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3046     possible to check for precisely this case. All we can do is abandon the
3047     optimization if .* occurs inside capturing brackets when there are any back
3048     references whatsoever. (See below for a better fix that came later.)
3050     26. The handling of the optimization for finding the first character of a
3051     non-anchored pattern, and for finding a character that is required later in the
3052     match were failing in some cases. This didn't break the matching; it just
3053     failed to optimize when it could. The way this is done has been re-implemented.
3055     27. Fixed typo in error message for invalid (?R item (it said "(?p").
3057     28. Added a new feature that provides some of the functionality that Perl
3058     provides with (?{...}). The facility is termed a "callout". The way it is done
3059     in PCRE is for the caller to provide an optional function, by setting
3060     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3061     global variable. By default it is unset, which disables all calling out. To get
3062     the function called, the regex must include (?C) at appropriate points. This
3063     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3064     This provides a means of identifying different callout points. When PCRE
3065     reaches such a point in the regex, if pcre_callout has been set, the external
3066     function is called. It is provided with data in a structure called
3067     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3068     matching continues; if it returns a non-zero value, the match at the current
3069     point fails. However, backtracking will occur if possible. [This was changed
3070     later and other features added - see item 49 below.]
3072     29. pcretest is upgraded to test the callout functionality. It provides a
3073     callout function that displays information. By default, it shows the start of
3074     the match and the current position in the text. There are some new data escapes
3075     to vary what happens:
3077     \C+ in addition, show current contents of captured substrings
3078     \C- do not supply a callout function
3079     \C!n return 1 when callout number n is reached
3080     \C!n!m return 1 when callout number n is reached for the mth time
3082     30. If pcregrep was called with the -l option and just a single file name, it
3083     output "<stdin>" if a match was found, instead of the file name.
3085     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3086     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3087     pcre_exec(). This saves a malloc/free per call. The default value of
3088     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3089     when configuring.
3091     32. The default maximum size of a compiled pattern is 64K. There have been a
3092     few cases of people hitting this limit. The code now uses macros to handle the
3093     storing of links as offsets within the compiled pattern. It defaults to 2-byte
3094     links, but this can be changed to 3 or 4 bytes by --with-link-size when
3095     configuring. Tests 2 and 5 work only with 2-byte links because they output
3096     debugging information about compiled patterns.
3098     33. Internal code re-arrangements:
3100     (a) Moved the debugging function for printing out a compiled regex into
3101     its own source file (printint.c) and used #include to pull it into
3102     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3103     separate copies.
3105     (b) Defined the list of op-code names for debugging as a macro in
3106     internal.h so that it is next to the definition of the opcodes.
3108     (c) Defined a table of op-code lengths for simpler skipping along compiled
3109     code. This is again a macro in internal.h so that it is next to the
3110     definition of the opcodes.
3112     34. Added support for recursive calls to individual subpatterns, along the
3113     lines of Robin Houston's patch (but implemented somewhat differently).
3115     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3116     allow it to read and process whole directories in Win32. This code was
3117     contributed by Lionel Fourquaux; it has not been tested by me.
3119     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3120     used to name a group. Names consist of alphanumerics and underscores, and must
3121     be unique. Back references use the syntax (?P=name) and recursive calls use
3122     (?P>name) which is a PCRE extension to the Python extension. Groups still have
3123     numbers. The function pcre_fullinfo() can be used after compilation to extract
3124     a name/number map. There are three relevant calls:
3126     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3127     PCRE_INFO_NAMECOUNT yields the number of entries
3128     PCRE_INFO_NAMETABLE yields a pointer to the map.
3130     The map is a vector of fixed-size entries. The size of each entry depends on
3131     the length of the longest name used. The first two bytes of each entry are the
3132     group number, most significant byte first. There follows the corresponding
3133     name, zero terminated. The names are in alphabetical order.
3135     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3136     case instead of 255. Making it the same both with and without UTF-8 support
3137     means that the same test output works with both.
3139     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3140     calling malloc() with a zero argument.
3142     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3143     optimization. I've improved things by keeping a bitmap of backreferences with
3144     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3145     fact referenced, the optimization can be applied. It is unlikely that a
3146     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3147     the match to follow \n) will appear inside brackets with a number greater than
3148     31, but if it does, any back reference > 31 suppresses the optimization.
3150     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3151     of disabling numbered capturing parentheses. Any opening parenthesis that is
3152     not followed by ? behaves as if it were followed by ?: but named parentheses
3153     can still be used for capturing (and they will acquire numbers in the usual
3154     way).
3156     41. Redesigned the return codes from the match() function into yes/no/error so
3157     that errors can be passed back from deep inside the nested calls. A malloc
3158     failure while inside a recursive subpattern call now causes the
3159     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3161     42. It is now possible to set a limit on the number of times the match()
3162     function is called in a call to pcre_exec(). This facility makes it possible to
3163     limit the amount of recursion and backtracking, though not in a directly
3164     obvious way, because the match() function is used in a number of different
3165     circumstances. The count starts from zero for each position in the subject
3166     string (for non-anchored patterns). The default limit is, for compatibility, a
3167     large number, namely 10 000 000. You can change this in two ways:
3169     (a) When configuring PCRE before making, you can use --with-match-limit=n
3170     to set a default value for the compiled library.
3172     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3173     a different value is set. See 45 below.
3175     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3177     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3178     of things that can be changed at compile time. The first argument specifies
3179     what is wanted and the second points to where the information is to be placed.
3180     The current list of available information is:
3184     The output is an integer that is set to one if UTF-8 support is available;
3185     otherwise it is set to zero.
3189     The output is an integer that it set to the value of the code that is used for
3190     newline. It is either LF (10) or CR (13).
3194     The output is an integer that contains the number of bytes used for internal
3195     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3199     The output is an integer that contains the threshold above which the POSIX
3200     interface uses malloc() for output vectors. See item 31 above.
3204     The output is an unsigned integer that contains the default limit of the number
3205     of match() calls in a pcre_exec() execution. See 42 above.
3207     44. pcretest has been upgraded by the addition of the -C option. This causes it
3208     to extract all the available output from the new pcre_config() function, and to
3209     output it. The program then exits immediately.
3211     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3212     order to support additional features. One way would have been to define
3213     pcre_exec2() (for example) with extra arguments, but this would not have been
3214     extensible, and would also have required all calls to the original function to
3215     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3216     is used for passing in "extra" data from pcre_study().
3218     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3219     contains the following fields:
3221     flags a bitmap indicating which of the following fields are set
3222     study_data opaque data from pcre_study()
3223     match_limit a way of specifying a limit on match() calls for a specific
3224     call to pcre_exec()
3225     callout_data data for callouts (see 49 below)
3227     The flag bits are also defined in pcre.h, and are
3233     The pcre_study() function now returns one of these new pcre_extra blocks, with
3234     the actual study data pointed to by the study_data field, and the
3235     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3236     before. That is, this change is entirely upwards-compatible and requires no
3237     change to existing code.
3239     If you want to pass in additional data to pcre_exec(), you can either place it
3240     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3241     block.
3243     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3244     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3245     times with different match limits, until it finds the minimum value needed for
3246     pcre_exec() to complete. The value is then output. This can be instructive; for
3247     most simple matches the number is quite small, but for pathological cases it
3248     gets very large very quickly.
3250     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3251     returns the size of the data block pointed to by the study_data field in a
3252     pcre_extra block, that is, the value that was passed as the argument to
3253     pcre_malloc() when PCRE was getting memory in which to place the information
3254     created by pcre_study(). The fourth argument should point to a size_t variable.
3255     pcretest has been extended so that this information is shown after a successful
3256     pcre_study() call when information about the compiled regex is being displayed.
3258     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3259     because what follows is always an absolute path. (Later: it turns out that this
3260     is more than cosmetic for MinGW, because it doesn't like empty path
3261     components.)
3263     49. Some changes have been made to the callout feature (see 28 above):
3265     (i) A callout function now has three choices for what it returns:
3267     0 => success, carry on matching
3268     > 0 => failure at this point, but backtrack if possible
3269     < 0 => serious error, return this value from pcre_exec()
3271     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3272     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3273     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3274     use by callout functions. It will never be used by PCRE itself.
3276     (ii) The pcre_extra structure (see 45 above) has a void * field called
3277     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3278     pcre_callout_block structure has a field of the same name. The contents of
3279     the field passed in the pcre_extra structure are passed to the callout
3280     function in the corresponding field in the callout block. This makes it
3281     easier to use the same callout-containing regex from multiple threads. For
3282     testing, the pcretest program has a new data escape
3284     \C*n pass the number n (may be negative) as callout_data
3286     If the callout function in pcretest receives a non-zero value as
3287     callout_data, it returns that value.
3289     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3290     there were some redundant $(CFLAGS) in commands that are now specified as
3291     $(LINK), which already includes $(CFLAGS).
3293     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3294     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3295     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3296     one-byte characters throughout. Note that case-insensitive matching applies
3297     only to characters whose values are less than 256. PCRE doesn't support the
3298     notion of cases for higher-valued characters.
3300     (i) A character class whose characters are all within 0-255 is handled as
3301     a bit map, and the map is inverted for negative classes. Previously, a
3302     character > 255 always failed to match such a class; however it should
3303     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3305     (ii) A negated character class with a single character < 255 is coded as
3306     "not this character" (OP_NOT). This wasn't working properly when the test
3307     character was multibyte, either singly or repeated.
3309     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3310     mode, for example: \x{100}{2,3}.
3312     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3313     singly or repeated) now correctly test multibyte characters. However,
3314     PCRE doesn't recognize any characters with values greater than 255 as
3315     digits, spaces, or word characters. Such characters always match \D, \S,
3316     and \W, and never match \d, \s, or \w.
3318     (v) Classes may now contain characters and character ranges with values
3319     greater than 255. For example: [ab\x{100}-\x{400}].
3321     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3322     PCRE in UTF-8 mode.
3324     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3325     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3326     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3327     value.)
3329     53. The single man page has become too large. I have therefore split it up into
3330     a number of separate man pages. These also give rise to individual HTML pages;
3331     these are now put in a separate directory, and there is an index.html page that
3332     lists them all. Some hyperlinking between the pages has been installed.
3334     54. Added convenience functions for handling named capturing parentheses.
3336     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3337     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3338     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3339     are faulted.
3341     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3342     calling configure. These values are used when compiling the dftables.c program
3343     which is run to generate the source of the default character tables. They
3344     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3345     you will need to set these values.
3347     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3350     Version 3.9 02-Jan-02
3351 nigel 61 ---------------------
3353     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3355     2. If --disable-static was given, the building process failed when trying to
3356     build pcretest and pcregrep. (For some reason it was using libtool to compile
3357     them, which is not right, as they aren't part of the library.)
3360 nigel 59 Version 3.8 18-Dec-01
3361     ---------------------
3363     1. The experimental UTF-8 code was completely screwed up. It was packing the
3364     bytes in the wrong order. How dumb can you get?
3367 nigel 57 Version 3.7 29-Oct-01
3368     ---------------------
3370     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3371     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3372     this didn't happen under Solaris 8, where I normally test things.
3374 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3375     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3376     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3377     this fix an hour or so after the initial 3.7 release.)
3378 nigel 57
3379 nigel 59
3380 nigel 55 Version 3.6 23-Oct-01
3381     ---------------------
3383     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3384     offsets passed as NULL with zero offset count.
3386     2. The config.guess and config.sub files had not been updated when I moved to
3387     the latest autoconf.
3390 nigel 53 Version 3.5 15-Aug-01
3391     ---------------------
3392 nigel 5
3393 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3394     had been forgotten.
3396     2. By using declared but undefined structures, we can avoid using "void"
3397     definitions in pcre.h while keeping the internal definitions of the structures
3398     private.
3400     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3401     user point of view, this means that both static and shared libraries are built
3402     by default, but this can be individually controlled. More of the work of
3403     handling this static/shared cases is now inside libtool instead of PCRE's make
3404     file.
3406     4. The pcretest utility is now installed along with pcregrep because it is
3407     useful for users (to test regexs) and by doing this, it automatically gets
3408     relinked by libtool. The documentation has been turned into a man page, so
3409     there are now .1, .txt, and .html versions in /doc.
3411     5. Upgrades to pcregrep:
3412     (i) Added long-form option names like gnu grep.
3413     (ii) Added --help to list all options with an explanatory phrase.
3414     (iii) Added -r, --recursive to recurse into sub-directories.
3415     (iv) Added -f, --file to read patterns from a file.
3417     6. pcre_exec() was referring to its "code" argument before testing that
3418     argument for NULL (and giving an error if it was NULL).
3420     7. Upgraded Makefile.in to allow for compiling in a different directory from
3421     the source directory.
3423     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3424     options bits, the pointer it was passed was to an int instead of to an unsigned
3425     long int. This mattered only on 64-bit systems.
3427     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3428     generated) instead of pcre.in, which it its source. Also made the same change
3429     in several of the .c files.
3431     10. A new release of gcc defines printf() as a macro, which broke pcretest
3432     because it had an ifdef in the middle of a string argument for printf(). Fixed
3433     by using separate calls to printf().
3435     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3436     script, to force use of CR or LF instead of \n in the source. On non-Unix
3437     systems, the value can be set in config.h.
3439     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3440     absolute limit. Changed the text of the error message to make this clear, and
3441     likewise updated the man page.
3443     13. The limit of 99 on the number of capturing subpatterns has been removed.
3444     The new limit is 65535, which I hope will not be a "real" limit.
3447 nigel 51 Version 3.4 22-Aug-00
3448     ---------------------
3450     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3452     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3455 nigel 49 Version 3.3 01-Aug-00
3456     ---------------------
3458     1. If an octal character was given, but the value was greater than \377, it
3459     was not getting masked to the least significant bits, as documented. This could
3460     lead to crashes in some systems.
3462     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3463     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3465     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3466     These just pass their arguments on to (pcre_free)(), but they are provided
3467     because some uses of PCRE bind it to non-C systems that can call its functions,
3468     but cannot call free() or pcre_free() directly.
3470     4. Add "make test" as a synonym for "make check". Corrected some comments in
3471     the Makefile.
3473     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3474     Makefile.
3476     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3477     command called pgrep for grepping around the active processes.
3479     7. Added the beginnings of support for UTF-8 character strings.
3481     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3482     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3483     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3484     out for the ar command.)
3487 nigel 47 Version 3.2 12-May-00
3488     ---------------------
3490     This is purely a bug fixing release.
3492     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3493     of ZA. This was just one example of several cases that could provoke this bug,
3494     which was introduced by change 9 of version 2.00. The code for breaking
3495     infinite loops after an iteration that matches an empty string was't working
3496     correctly.
3498     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3499     when matched against abbab (for example). After matching an empty string, it
3500     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3501     caused it to match further down the string than it should.
3503     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3504     was there because it doesn't seem to be needed, and it causes trouble on some
3505     systems, as it is not a Standard C header. It has been removed.
3507     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3508     were reported on the Macintosh. The changes were from
3510     while ((c = *(++ptr)) != 0 && c != '\n');
3511     to
3512     while ((c = *(++ptr)) != 0 && c != '\n') ;
3514     Totally extraordinary, but if that's what it takes...
3516     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3517     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3518     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3519     assumes the way PCRE uses memmove() (always moving upwards).
3521     6. PCRE is being used in one environment where strchr() is not available. There
3522     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3523     faster code anyway.
3526 nigel 45 Version 3.1 09-Feb-00
3527     ---------------------
3529     The only change in this release is the fixing of some bugs in Makefile.in for
3530     the "install" target:
3532     (1) It was failing to install pcreposix.h.
3534     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3537 nigel 43 Version 3.0 01-Feb-00
3538     ---------------------
3539 nigel 41
3540     1. Add support for the /+ modifier to perltest (to output $` like it does in
3541     pcretest).
3543     2. Add support for the /g modifier to perltest.
3545     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3546     matches null strings.
3548     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3549     pattern. Perl treats empty patterns specially - it reuses the most recent
3550     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3551     effect.
3553     5. The POSIX interface was broken in that it was just handing over the POSIX
3554     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3555     required a bigger vector, with some working space on the end. This means that
3556     the POSIX wrapper now has to get and free some memory, and copy the results.
3558 nigel 43 6. Added some simple autoconf support, placing the test data and the
3559     documentation in separate directories, re-organizing some of the
3560     information files, and making it build pcre-config (a GNU standard). Also added
3561     libtool support for building PCRE as a shared library, which is now the
3562     default.
3563 nigel 41
3564 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3565     09 are not valid octal constants. Single digits will be used for minor values
3566     less than 10.
3568     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3569     existing programs that set these in the POSIX interface can use PCRE without
3570     modification.
3572     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3573     return all that pcre_info() returns, plus additional data. The pcre_info()
3574     function is retained for compatibility, but is considered to be obsolete.
3576     10. Added experimental recursion feature (?R) to handle one common case that
3577     Perl 5.6 will be able to do with (?p{...}).
3579     11. Added support for POSIX character classes like [:alpha:], which Perl is
3580     adopting.
3583 nigel 39 Version 2.08 31-Aug-99
3584     ----------------------
3586     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3587     trying to match at the startoffset position, but instead was moving forward to
3588     the next newline as if a previous match had failed.
3590     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3591     and could get into a loop if a null string was matched other than at the start
3592     of the subject.
3594     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3595     be distinguished at compile time, and for completeness also added PCRE_DATE.
3597     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3598     in GnuWin32 environments.
3601 nigel 37 Version 2.07 29-Jul-99
3602     ----------------------
3604     1. The documentation is now supplied in plain text form and HTML as well as in
3605     the form of man page sources.
3607     2. C++ compilers don't like assigning (void *) values to other pointer types.
3608     In particular this affects malloc(). Although there is no problem in Standard
3609     C, I've put in casts to keep C++ compilers happy.
3611     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3612     should be (const char *).
3614     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3615     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3616     However, I haven't made this a standard facility. The documentation doesn't
3617     mention it, and the Makefile doesn't support it.
3619     5. The Makefile now contains an "install" target, with editable destinations at
3620     the top of the file. The pcretest program is not installed.
3622     6. pgrep -V now gives the PCRE version number and date.
3624     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3625     causing the entire string to be ignored, instead of just the last character.
3627     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3628     non-matching string, it can take a very, very long time, even for strings of
3629     quite modest length, because of the nested recursion. PCRE now does better in
3630     some of these cases. It does this by remembering the last required literal
3631     character in the pattern, and pre-searching the subject to ensure it is present
3632     before running the real match. In other words, it applies a heuristic to detect
3633     some types of certain failure quickly, and in the above example, if presented
3634     with a string that has no trailing " it gives "no match" very quickly.
3636     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3637     other alternatives are tried instead.
3640 nigel 35 Version 2.06 09-Jun-99
3641     ----------------------
3643     1. Change pcretest's output for amount of store used to show just the code
3644     space, because the remainder (the data block) varies in size between 32-bit and
3645     64-bit systems.
3647     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3648     start matching at. This allows lookbehinds to work when searching for multiple
3649     occurrences in a string.
3651     3. Added additional options to pcretest for testing multiple occurrences:
3653     /+ outputs the rest of the string that follows a match
3654     /g loops for multiple occurrences, using the new startoffset argument
3655     /G loops for multiple occurrences by passing an incremented pointer
3657     4. PCRE wasn't doing the "first character" optimization for patterns starting
3658     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3659     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3660     the letter 'x'. On long subject strings, this gives a significant speed-up.
3663 nigel 33 Version 2.05 21-Apr-99
3664     ----------------------
3666     1. Changed the type of magic_number from int to long int so that it works
3667     properly on 16-bit systems.
3669     2. Fixed a bug which caused patterns starting with .* not to work correctly
3670     when the subject string contained newline characters. PCRE was assuming
3671     anchoring for such patterns in all cases, which is not correct because .* will
3672     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3673     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3674     must be retried after every newline in the subject.
3677 nigel 31 Version 2.04 18-Feb-99
3678     ----------------------
3680     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3681     computation of the store needed to hold the pattern was incorrect (too large).
3682     If such patterns were nested a few deep, this could multiply and become a real
3683     problem.
3685     2. Added /M option to pcretest to show the memory requirement of a specific
3686     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3688     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3689     compiled in such a way that the backtracking after subsequent failure was
3690     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3691     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3694 nigel 29 Version 2.03 02-Feb-99
3695     ----------------------
3697     1. Fixed typo and small mistake in man page.
3699 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3700     LICENCE file containing the conditions.
3701 nigel 29
3702     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3703     Perl, that is the internal \ allows the delimiter to be included in the
3704     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3705     the final delimiter, add \ to the end of the pattern (to test the error).
3707     4. Added the convenience functions for extracting substrings after a successful
3708     match. Updated pcretest to make it able to test these functions.
3711 nigel 27 Version 2.02 14-Jan-99
3712     ----------------------
3714     1. Initialized the working variables associated with each extraction so that
3715     their saving and restoring doesn't refer to uninitialized store.
3717     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3718     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3719     fix the problem.
3721     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3722     calls, and wasn't printing the correct value for compiling calls. Increased the
3723     default value of LOOPREPEAT, and the number of significant figures in the
3724     times.