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Revision 567 - (hide annotations) (download)
Sat Nov 6 17:10:00 2010 UTC (3 years, 5 months ago) by ph10
File size: 194606 byte(s)
Test for ridiculous values of starting offsets; tidy UTF-8 code.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 550 Version 8.11 10-Oct-2010
5     ------------------------
6    
7     1. (*THEN) was not working properly if there were untried alternatives prior
8     to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
9     backtracked to try for "b" instead of moving to the next alternative branch
10     at the same level (in this case, to look for "c"). The Perl documentation
11     is clear that when (*THEN) is backtracked onto, it goes to the "next
12     alternative in the innermost enclosing group".
13 ph10 551
14     2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
15     such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
16     result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
17     (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
18     (*THEN).
19 ph10 552
20     3. If \s appeared in a character class, it removed the VT character from
21     the class, even if it had been included by some previous item, for example
22     in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
23     of \s, but is part of the POSIX "space" class.)
24 ph10 553
25     4. A partial match never returns an empty string (because you can always
26     match an empty string at the end of the subject); however the checking for
27     an empty string was starting at the "start of match" point. This has been
28     changed to the "earliest inspected character" point, because the returned
29     data for a partial match starts at this character. This means that, for
30     example, /(?<=abc)def/ gives a partial match for the subject "abc"
31     (previously it gave "no match").
32 ph10 550
33 ph10 553 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
34     of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
35     previously a full match would be given. However, setting PCRE_PARTIAL_HARD
36     has an implication that the given string is incomplete (because a partial
37     match is preferred over a full match). For this reason, these items now
38     give a partial match in this situation. [Aside: previously, the one case
39     /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
40     match rather than a full match, which was wrong by the old rules, but is
41     now correct.]
42 ph10 556
43     6. There was a bug in the handling of #-introduced comments, recognized when
44     PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
45     If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
46     UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
47     scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
48     but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
49     places in pcre_compile().
50    
51     7. Related to (6) above, when pcre_compile() was skipping #-introduced
52     comments when looking ahead for named forward references to subpatterns,
53     the only newline sequence it recognized was NL. It now handles newlines
54     according to the set newline convention.
55 ph10 558
56     8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
57     former, but used strtoul(), whereas pcretest avoided strtoul() but did not
58     cater for a lack of strerror(). These oversights have been fixed.
59 ph10 561
60     9. Added --match-limit and --recursion-limit to pcregrep.
61 ph10 550
62 ph10 563 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
63 ph10 553
64 ph10 564 11. When the -o option was used, pcregrep was setting a return code of 1, even
65     when matches were found, and --line-buffered was not being honoured.
66 ph10 565
67     12. Added an optional parentheses number to the -o and --only-matching options
68     of pcregrep.
69 ph10 566
70     13. Imitating Perl's /g action for multiple matches is tricky when the pattern
71     can match an empty string. The code to do it in pcretest and pcredemo
72     needed fixing:
73    
74     (a) When the newline convention was "crlf", pcretest got it wrong, skipping
75     only one byte after an empty string match just before CRLF (this case
76     just got forgotten; "any" and "anycrlf" were OK).
77    
78     (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
79     mode when an empty string match preceded an ASCII character followed by
80     a non-ASCII character. (The code for advancing by one character rather
81     than one byte was nonsense.)
82    
83     (c) The pcredemo.c sample program did not have any code at all to handle
84     the cases when CRLF is a valid newline sequence.
85 ph10 567
86     14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
87     as a starting offset was within the subject string. There is now a new
88     error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
89     negative or greater than the length of the string. In order to test this,
90     pcretest is extended to allow the setting of negative starting offsets.
91    
92     15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
93     starting offset points to the beginning of a UTF-8 character was
94     unnecessarily clumsy. I tidied it up.
95 ph10 563
96 ph10 564
97 ph10 548 Version 8.10 25-Jun-2010
98 ph10 510 ------------------------
99    
100 ph10 512 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
101 ph10 510 THEN.
102    
103 ph10 512 2. (*ACCEPT) was not working when inside an atomic group.
104 ph10 510
105 ph10 535 3. Inside a character class, \B is treated as a literal by default, but
106     faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
107 ph10 513 causes the error). The code is unchanged, but I tidied the documentation.
108 ph10 535
109     4. Inside a character class, PCRE always treated \R and \X as literals,
110 ph10 513 whereas Perl faults them if its -w option is set. I have changed PCRE so
111     that it faults them when PCRE_EXTRA is set.
112 ph10 535
113 ph10 514 5. Added support for \N, which always matches any character other than
114     newline. (It is the same as "." when PCRE_DOTALL is not set.)
115 ph10 535
116 ph10 515 6. When compiling pcregrep with newer versions of gcc which may have
117 ph10 535 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
118 ph10 515 declared with attribute warn_unused_result" were given. Just casting the
119 ph10 535 result to (void) does not stop the warnings; a more elaborate fudge is
120     needed. I've used a macro to implement this.
121 ph10 512
122 ph10 535 7. Minor change to pcretest.c to avoid a compiler warning.
123    
124 ph10 517 8. Added four artifical Unicode properties to help with an option to make
125 ph10 518 \s etc use properties (see next item). The new properties are: Xan
126     (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
127 ph10 535
128 ph10 518 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
129 ph10 535 use Unicode properties. (*UCP) at the start of a pattern can be used to set
130 ph10 518 this option. Modified pcretest to add /W to test this facility. Added
131     REG_UCP to make it available via the POSIX interface.
132 ph10 513
133 ph10 535 10. Added --line-buffered to pcregrep.
134    
135     11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
136     studied, and the match started with a letter with a code point greater than
137 ph10 520 127 whose first byte was different to the first byte of the other case of
138 ph10 545 the letter, the other case of this starting letter was not recognized
139 ph10 536 (#976).
140 ph10 535
141 ph10 536 12. If a pattern that was studied started with a repeated Unicode property
142 ph10 523 test, for example, \p{Nd}+, there was the theoretical possibility of
143 ph10 535 setting up an incorrect bitmap of starting bytes, but fortunately it could
144     not have actually happened in practice until change 8 above was made (it
145 ph10 523 added property types that matched character-matching opcodes).
146 ph10 535
147 ph10 536 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
148 ph10 535 possible starting bytes for non-anchored patterns.
149    
150 ph10 536 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
151 ph10 535 \R, and also a number of cases that involve Unicode properties, both
152 ph10 532 explicit and implicit when PCRE_UCP is set.
153 ph10 529
154 ph10 536 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
155 ph10 535 input, it could crash or give wrong results if characters with values
156     greater than 0xc0 were present in the subject string. (Detail: it assumed
157 ph10 529 UTF-8 input when processing these items.)
158 ph10 535
159 ph10 536 16. Added a lot of (int) casts to avoid compiler warnings in systems where
160     size_t is 64-bit (#991).
161 ph10 535
162 ph10 536 17. Added a check for running out of memory when PCRE is compiled with
163     --disable-stack-for-recursion (#990).
164 ph10 545
165 ph10 537 18. If the last data line in a file for pcretest does not have a newline on
166 ph10 545 the end, a newline was missing in the output.
167    
168     19. The default pcre_chartables.c file recognizes only ASCII characters (values
169     less than 128) in its various bitmaps. However, there is a facility for
170     generating tables according to the current locale when PCRE is compiled. It
171     turns out that in some environments, 0x85 and 0xa0, which are Unicode space
172     characters, are recognized by isspace() and therefore were getting set in
173 ph10 541 these tables, and indeed these tables seem to approximate to ISO 8859. This
174     caused a problem in UTF-8 mode when pcre_study() was used to create a list
175     of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
176     which of course cannot start UTF-8 characters. I have changed the code so
177     that only real ASCII characters (less than 128) and the correct starting
178 ph10 545 bytes for UTF-8 encodings are set for characters greater than 127 when in
179 ph10 541 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
180     altogether.)
181 ph10 545
182 ph10 541 20. Added the /T option to pcretest so as to be able to run tests with non-
183     standard character tables, thus making it possible to include the tests
184 ph10 545 used for 19 above in the standard set of tests.
185    
186     21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
187     reference to a subpattern the other side of a comment that contains an
188     opening parenthesis caused either an internal compiling error, or a
189 ph10 544 reference to the wrong subpattern.
190 ph10 517
191 ph10 520
192 ph10 508 Version 8.02 19-Mar-2010
193 ph10 491 ------------------------
194    
195     1. The Unicode data tables have been updated to Unicode 5.2.0.
196    
197 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
198     configured.
199 ph10 507
200 ph10 493 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
201 ph10 507 original author of that file, following a query about its status.
202    
203     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
204 ph10 494 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
205 ph10 507
206 ph10 496 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
207     quantifier applied to a forward-referencing subroutine call, could compile
208     incorrect code or give the error "internal error: previously-checked
209     referenced subpattern not found".
210 ph10 507
211     6. Both MS Visual Studio and Symbian OS have problems with initializing
212 ph10 497 variables to point to external functions. For these systems, therefore,
213     pcre_malloc etc. are now initialized to local functions that call the
214     relevant global functions.
215 ph10 507
216 ph10 498 7. There were two entries missing in the vectors called coptable and poptable
217     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
218 ph10 507 I've fixed the data, and added a kludgy way of testing at compile time that
219     the lengths are correct (equal to the number of opcodes).
220    
221     8. Following on from 7, I added a similar kludge to check the length of the
222     eint vector in pcreposix.c.
223    
224     9. Error texts for pcre_compile() are held as one long string to avoid too
225     much relocation at load time. To find a text, the string is searched,
226 ph10 499 counting zeros. There was no check for running off the end of the string,
227     which could happen if a new error number was added without updating the
228 ph10 507 string.
229    
230     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
231    
232 ph10 500 11. \K was not working if it appeared in an atomic group or in a group that
233 ph10 507 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
234     \K is "not well defined" if used in an assertion. PCRE now accepts it if
235     the assertion is positive, but not if it is negative.
236    
237 ph10 501 12. Change 11 fortuitously reduced the size of the stack frame used in the
238 ph10 507 "match()" function of pcre_exec.c by one pointer. Forthcoming
239     implementation of support for (*MARK) will need an extra pointer on the
240 ph10 501 stack; I have reserved it now, so that the stack frame size does not
241     decrease.
242 ph10 507
243     13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
244     item in branch that calls a recursion is a subroutine call - as in the
245 ph10 503 second branch in the above example - was incorrectly given the compile-
246     time error "recursive call could loop indefinitely" because pcre_compile()
247 ph10 507 was not correctly checking the subroutine for matching a non-empty string.
248    
249 ph10 505 14. The checks for overrunning compiling workspace could trigger after an
250 ph10 507 overrun had occurred. This is a "should never occur" error, but it can be
251 ph10 505 triggered by pathological patterns such as hundreds of nested parentheses.
252 ph10 507 The checks now trigger 100 bytes before the end of the workspace.
253 ph10 491
254 ph10 507 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
255 ph10 492
256 ph10 507
257 ph10 489 Version 8.01 19-Jan-2010
258     ------------------------
259 ph10 471
260     1. If a pattern contained a conditional subpattern with only one branch (in
261 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
262 ph10 473 computed the wrong minimum data length (which is of course zero for such
263 ph10 489 subpatterns). This could cause incorrect "no match" results.
264 ph10 473
265     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
266 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
267     "internal error: code overflow at offset...". This happened only when
268 ph10 473 the reset was to the original external option setting. (An optimization
269     abstracts leading options settings into an external setting, which was the
270 ph10 472 cause of this.)
271 ph10 471
272 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
273     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
274     assertion pattern did not match (meaning that the assertion was true), it
275     was incorrectly treated as false if the SKIP had been reached during the
276     matching. This also applied to assertions used as conditions.
277 ph10 471
278 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
279     assertion subpattern, including such a pattern used as a condition,
280     unpredictable results occurred, instead of the error return
281     PCRE_ERROR_DFA_UITEM.
282 ph10 478
283 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
284     situation when an empty string is matched. It now does the fancy magic
285 ph10 478 stuff that is necessary.
286    
287     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
288 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
289 ph10 478
290 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
291     as part of something else:
292 ph10 478
293     (a) Change DEBUG to PCRE_DEBUG.
294    
295     (b) In pcre_compile(), rename the member of the "branch_chain" structure
296     called "current" as "current_branch", to prevent a collision with the
297 ph10 475 Linux macro when compiled as a kernel module.
298 ph10 478
299     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
300     prevent a collision with the Linux macro when compiled as a kernel
301 ph10 475 module.
302 ph10 478
303 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
304     cast potentially large values to (double). This has been changed to that
305 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
306     instead, thus avoiding the use of floating point arithmetic. (There is no
307     other use of FP in PCRE.) If int64_t is not found, the fallback is to
308     double.
309    
310     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
311 ph10 476 2005 (difference between two addresses compared to an unsigned value).
312 ph10 473
313 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
314     custom one, because of the following reported problem in Windows:
315 ph10 473
316 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
317 ph10 489 under Win32.
318 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
319 ph10 489 therefore missing the function definition.
320 ph10 478 - The compiler thus generates a "C" signature for the test function.
321     - The linker fails to find the "C" function.
322     - PCRE fails to configure if asked to do so against libbz2.
323 ph10 486
324 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
325     messages were output:
326 ph10 478
327 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
328     rerunning libtoolize, to keep the correct libtool macros in-tree.
329     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
330 ph10 486
331 ph10 479 I have done both of these things.
332 ph10 486
333 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
334 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
335     runaway infinite recursion. I updated the discussion in the pcrestack man
336     page.
337    
338     13. Now that we have gone to the x.xx style of version numbers, the minor
339     version may start with zero. Using 08 or 09 is a bad idea because users
340     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
341     interpreted as invalid octal numbers. I've updated the previous comment in
342     configure.ac, and also added a check that gives an error if 08 or 09 are
343 ph10 481 used.
344 ph10 486
345 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
346 ph10 483 causing partial matching to fail when the end of the subject matched \W
347     in a UTF-8 pattern where \W was quantified with a minimum of 3.
348 ph10 486
349 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
350 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
351 ph10 483 their definitions. The declarations used "const uschar *" and the
352     definitions used USPTR. Even though USPTR is normally defined as "const
353     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
354     reported that: "This difference in casting confuses some C++ compilers, for
355     example, SunCC recognizes above declarations as different functions and
356 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
357 ph10 483 USPTR.
358 ph10 486
359     16. GNU libtool is named differently on some systems. The autogen.sh script now
360 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
361     (FreeBSD).
362 ph10 478
363 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
364     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
365     comment: "Figure out how to create a longlong from a string: strtoll and
366     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
367     instance, but it only takes 2 args instead of 3!"
368 ph10 479
369 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
370     specification, with a corresponding code fix. A pattern such as
371     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
372     refers, was giving matches when it shouldn't. For example, xa=xaaa would
373     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
374     same bug. Such groups have to be quantified to be useful, or contained
375     inside another quantified group. (If there's no repetition, the reference
376     can never match.) The problem arises because, having left the group and
377     moved on to the rest of the pattern, a later failure that backtracks into
378     the group uses the captured value from the final iteration of the group
379     rather than the correct earlier one. I have fixed this in PCRE by forcing
380     any group that contains a reference to itself to be an atomic group; that
381     is, there cannot be any backtracking into it once it has completed. This is
382     similar to recursive and subroutine calls.
383 ph10 486
384 ph10 488
385 ph10 469 Version 8.00 19-Oct-09
386 ph10 418 ----------------------
387    
388     1. The table for translating pcre_compile() error codes into POSIX error codes
389 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
390     being within the table. This could lead to an OK return being given in
391 ph10 418 error.
392 ph10 461
393     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
394     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
395     in a Windows environment.
396    
397 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
398     zero, as does GNU grep. However, pcregrep was also printing all files when
399     --files-with-matches was added. Now, when both options are given, it prints
400     counts only for those files that have at least one match. (GNU grep just
401 ph10 461 prints the file name in this circumstance, but including the count seems
402     more useful - otherwise, why use --count?) Also ensured that the
403 ph10 420 combination -clh just lists non-zero counts, with no names.
404 ph10 461
405     4. The long form of the pcregrep -F option was incorrectly implemented as
406     --fixed_strings instead of --fixed-strings. This is an incompatible change,
407     but it seems right to fix it, and I didn't think it was worth preserving
408     the old behaviour.
409    
410     5. The command line items --regex=pattern and --regexp=pattern were not
411 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
412 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
413 ph10 422 which are compatible with GNU grep; these now work.
414 ph10 461
415     6. No libpcreposix.pc file was created for pkg-config; there was just
416 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
417 ph10 461
418 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
419 ph10 461 when UCP support is not needed, by modifying the Python script that
420 ph10 425 generates it from Unicode data files. This should not matter if the module
421     is correctly used as a library, but I received one complaint about 50K of
422     unwanted data. My guess is that the person linked everything into his
423     program rather than using a library. Anyway, it does no harm.
424 ph10 461
425 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
426 ph10 461 was a minimum greater than 1 for a wide character in a possessive
427 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
428     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
429     character. Chaos in the form of incorrect output or a compiling loop could
430     result.
431 ph10 461
432 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
433 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
434 ph10 426 partially matched by this function. In addition, if there are at least two
435 ph10 435 slots in the offset vector, the offset of the earliest inspected character
436     for the match and the offset of the end of the subject are set in them when
437 ph10 461 PCRE_ERROR_PARTIAL is returned.
438    
439 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
440     synonymous with PCRE_PARTIAL, for backwards compatibility, and
441     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
442 ph10 462 and may be more useful for multi-segment matching.
443 ph10 461
444     11. Partial matching with pcre_exec() is now more intuitive. A partial match
445     used to be given if ever the end of the subject was reached; now it is
446     given only if matching could not proceed because another character was
447     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
448     string "Z", which now yields "no match" instead of "partial match". In the
449     case of pcre_dfa_exec(), "no match" is given if every matching path for the
450     final character ended with (*FAIL).
451    
452 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
453 ph10 461 if the pattern had a "must contain" character that was already found in the
454 ph10 428 earlier partial match, unless partial matching was again requested. For
455     example, with the pattern /dog.(body)?/, the "must contain" character is
456     "g". If the first part-match was for the string "dog", restarting with
457 ph10 435 "sbody" failed. This bug has been fixed.
458 ph10 461
459     13. The string returned by pcre_dfa_exec() after a partial match has been
460     changed so that it starts at the first inspected character rather than the
461     first character of the match. This makes a difference only if the pattern
462     starts with a lookbehind assertion or \b or \B (\K is not supported by
463     pcre_dfa_exec()). It's an incompatible change, but it makes the two
464 ph10 435 matching functions compatible, and I think it's the right thing to do.
465 ph10 461
466 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
467 ph10 461 so that the demonstration program is easily available in environments where
468     PCRE has not been installed from source.
469    
470 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
471 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
472     library.
473 ph10 461
474 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
475 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
476 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
477 ph10 433 these options useful.
478 ph10 461
479     17. If a caller to the POSIX matching function regexec() passes a non-zero
480 ph10 438 value for nmatch with a NULL value for pmatch, the value of
481 ph10 461 nmatch is forced to zero.
482    
483 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
484 ph10 461 the diff command, as RunTest does. It now checks in the same way as
485 ph10 437 RunTest, and also checks for the -b option.
486 ph10 461
487 ph10 438 19. If an odd number of negated classes containing just a single character
488     interposed, within parentheses, between a forward reference to a named
489 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
490     an internal error, complaining that it could not find the referenced
491 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
492 ph10 461 [The bug was that it was starting one character too far in when skipping
493     over the character class, thus treating the ] as data rather than
494     terminating the class. This meant it could skip too much.]
495    
496 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
497 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
498 ph10 442 to have an empty string match not at the start, even when the pattern is
499 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
500    
501 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
502 ph10 461 than the maximum at the outer level, the higher number was returned, but
503     with unset values at the outer level. The correct (outer level) value is
504 ph10 446 now given.
505 ph10 461
506 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
507     PCRE did not set those parentheses (unlike Perl). I have now found a way to
508     make it do so. The string so far is captured, making this feature
509     compatible with Perl.
510 ph10 461
511     23. The tests have been re-organized, adding tests 11 and 12, to make it
512 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
513 ph10 461
514 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
515 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
516     does. Neither allows recursion.
517    
518     25. I finally figured out how to implement a request to provide the minimum
519     length of subject string that was needed in order to match a given pattern.
520     (It was back references and recursion that I had previously got hung up
521     on.) This code has now been added to pcre_study(); it finds a lower bound
522 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
523     bound, but using it to avoid searching strings that are too short does give
524     some useful speed-ups. The value is available to calling programs via
525     pcre_fullinfo().
526 ph10 461
527 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
528     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
529     study optimizations had never been tested with that matching function.
530     Oops. What is worse, even when it was passed study data, there was a bug in
531     pcre_dfa_exec() that meant it never actually used it. Double oops. There
532     were also very few tests of studied patterns with pcre_dfa_exec().
533 ph10 461
534 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
535     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
536     on the other side of the coin, they are no longer allowed to have different
537     names, because these cannot be distinguished in PCRE, and this has caused
538     confusion. (This is a difference from Perl.)
539 ph10 461
540     28. When duplicate subpattern names are present (necessarily with different
541     numbers, as required by 27 above), and a test is made by name in a
542     conditional pattern, either for a subpattern having been matched, or for
543     recursion in such a pattern, all the associated numbered subpatterns are
544 ph10 459 tested, and the overall condition is true if the condition is true for any
545     one of them. This is the way Perl works, and is also more like the way
546     testing by number works.
547 ph10 418
548 ph10 461
549 ph10 412 Version 7.9 11-Apr-09
550 ph10 376 ---------------------
551    
552 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
553 ph10 376 (pcretest), all targets were linked against these libraries. This included
554     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
555     libraries. This caused unwanted dependencies to be created. This problem
556 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
557 ph10 376 pcretest is linked with readline.
558 ph10 392
559 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
560     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
561     moved outside it again, because FALSE and TRUE are already defined in AIX,
562     but BOOL is not.
563 ph10 392
564     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
565 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
566 ph10 392
567 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
568     hyphens) following file names and line numbers when outputting matching
569 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
570 ph10 376 wording for the --colour (or --color) option.
571 ph10 392
572 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
573     was not coloured; this is different to GNU grep, so I have changed it to be
574     the same.
575 ph10 392
576 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
577 ph10 392 each matching line was coloured. Now it goes on to look for further matches
578     of any of the test patterns, which is the same behaviour as GNU grep.
579    
580     7. A pattern that could match an empty string could cause pcregrep to loop; it
581     doesn't make sense to accept an empty string match in pcregrep, so I have
582 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
583     seems to be how GNU grep behaves.
584 ph10 392
585 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
586 ph10 392 start or after a newline", because the conditional assertion was not being
587     correctly handled. The rule now is that both the assertion and what follows
588     in the first alternative must satisfy the test.
589    
590 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
591 ph10 399 condition was an assertion, PCRE could crash during matching, both with
592     pcre_exec() and pcre_dfa_exec().
593 ph10 392
594     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
595     used for matching.
596    
597     11. Unicode property support in character classes was not working for
598 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
599 ph10 388
600 ph10 392 12. Added the -M command line option to pcretest.
601    
602 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
603 ph10 389
604     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
605 ph10 390
606 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
607 ph10 390 wrapper.
608 ph10 392
609 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
610 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
611 ph10 391 string constants.
612 ph10 405
613 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
614     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
615 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
616     these, but not everybody uses configure.
617    
618     19. A conditional group that had only one branch was not being correctly
619     recognized as an item that could match an empty string. This meant that an
620     enclosing group might also not be so recognized, causing infinite looping
621     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
622     with the subject "ab", where knowledge that the repeated group can match
623 ph10 396 nothing is needed in order to break the loop.
624 ph10 405
625 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
626 ph10 405 exec(), but without supplying a callout function, matching went wrong.
627    
628     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
629     leak if the size of the offset vector was greater than 30. When the vector
630     is smaller, the saved offsets during recursion go onto a local stack
631     vector, but for larger vectors malloc() is used. It was failing to free
632     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
633 ph10 400 error, in fact).
634 ph10 405
635 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
636 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
637     problem, but was untidy.
638 ph10 376
639 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
640     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
641     included within another project.
642 ph10 411
643 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
644     slightly modified by me:
645 ph10 411
646     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
647     not building pcregrep.
648    
649 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
650 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
651    
652 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
653     duplicate group numbers, could behave incorrectly or give incorrect errors,
654     because when scanning forward to find the reference group, PCRE was not
655     taking into account the duplicate group numbers. A pattern such as
656     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
657 ph10 411
658     26. Changed a few more instances of "const unsigned char *" to USPTR, making
659     the feature of a custom pointer more persuasive (as requested by a user).
660 ph10 416
661 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
662 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
663     pre-defined.
664 ph10 392
665 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
666    
667 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
668     in the configuration summary.
669 ph10 405
670 ph10 411
671 ph10 374 Version 7.8 05-Sep-08
672 ph10 349 ---------------------
673    
674     1. Replaced UCP searching code with optimized version as implemented for Ad
675     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
676 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
677     to 5 times on some simple patterns that I tested. Permission was given to
678     distribute the MultiStage2.py script that generates the tables (it's not in
679     the tarball, but is in the Subversion repository).
680 ph10 349
681 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
682     scripts.
683 ph10 358
684 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
685     a group with a zero qualifier. The result of the study could be incorrect,
686 ph10 358 or the function might crash, depending on the pattern.
687    
688     4. Caseless matching was not working for non-ASCII characters in back
689 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
690 ph10 358 It now works when Unicode Property Support is available.
691    
692 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
693     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
694     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
695 ph10 358 truncation.
696 ph10 349
697 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
698    
699 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
700     pointers, in case they are 64-bit values.
701 ph10 371
702     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
703     test 2 if it fails.
704    
705 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
706 ph10 371 and a #define of that name to empty if it is not externally set. This is to
707     allow users of MSVC to set it if necessary.
708    
709     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
710 ph10 359 the convenience functions in the pcre_get.c source file.
711 ph10 371
712 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
713     could cause overwriting and/or a crash. This command provoked a crash in
714 ph10 371 some environments:
715    
716     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
717    
718 ph10 360 This potential security problem was recorded as CVE-2008-2371.
719 ph10 371
720 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
721     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
722 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
723 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
724     pcretest so that it places the subject at the end of its malloc-ed buffer.
725 ph10 371
726 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
727 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
728    
729 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
730 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
731     first line. This applied both to normal and DFA matching.
732    
733 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
734 ph10 371 /^[^d]*?$/8 failed to match "abc".
735 ph10 351
736 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
737    
738     17. Make it more clear in the documentation that values returned from
739 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
740 ph10 357
741 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
742 ph10 368
743 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
744     supplied by Stefan Weber. I made a further small update for 7.8 because
745 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
746     replaced by pcre_ucd.c.
747 ph10 371
748 ph10 373
749 ph10 347 Version 7.7 07-May-08
750 ph10 321 ---------------------
751    
752     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
753 ph10 345 a string to a long long, pretend we don't even have a long long." This is
754 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
755 ph10 345
756 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
757     pre-7.6 versions, which defined a global no_arg variable instead of putting
758 ph10 332 it in the RE class. (See also #8 below.)
759 ph10 345
760     3. Remove a line of dead code, identified by coverity and reported by Nuno
761     Lopes.
762    
763 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
764 ph10 321
765 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
766 ph10 345 of files, instead of just to the final components.
767    
768 ph10 324 (2) If there was more than one level of directory, the subdirectories were
769     skipped unless they satisfied the include/exclude conditions. This is
770     inconsistent with GNU grep (and could even be seen as contrary to the
771     pcregrep specification - which I improved to make it absolutely clear).
772     The action now is always to scan all levels of directory, and just
773     apply the include/exclude patterns to regular files.
774 ph10 345
775 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
776 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
777    
778 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
779 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
780 ph10 326 doesn't support NULs in patterns.
781 ph10 345
782     7. Added some missing "const"s to declarations of static tables in
783     pcre_compile.c and pcre_dfa_exec.c.
784    
785 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
786 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
787 ph10 345 first patch. And a third patch - this was a messy problem.)
788 ph10 321
789 ph10 345 9. Applied Craig's patch to remove the use of push_back().
790    
791 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
792     matching function regexec().
793 ph10 345
794     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
795     which, however, unlike Perl's \g{...}, are subroutine calls, not back
796 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
797     Oniguruma does).
798 ph10 345
799     12. Previously, a group with a zero repeat such as (...){0} was completely
800 ph10 335 omitted from the compiled regex. However, this means that if the group
801     was called as a subroutine from elsewhere in the pattern, things went wrong
802 ph10 345 (an internal error was given). Such groups are now left in the compiled
803     pattern, with a new opcode that causes them to be skipped at execution
804 ph10 335 time.
805 ph10 345
806 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
807     to the way PCRE behaves:
808 ph10 345
809 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
810 ph10 345
811     (b) A back reference to an unmatched subpattern matches an empty string
812 ph10 336 (Perl fails the current match path).
813 ph10 345
814 ph10 341 (c) A data ] in a character class must be notated as \] because if the
815 ph10 345 first data character in a class is ], it defines an empty class. (In
816 ph10 341 Perl it is not possible to have an empty class.) The empty class []
817     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
818     The negative empty class [^] matches any one character, independently
819     of the DOTALL setting.
820 ph10 345
821     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
822 ph10 340 non-existent subpattern following a character class starting with ']' and
823     containing () gave an internal compiling error instead of "reference to
824     non-existent subpattern". Fortunately, when the pattern did exist, the
825 ph10 345 compiled code was correct. (When scanning forwards to check for the
826 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
827 ph10 345 the class, so got the count wrong. When actually compiling, the reference
828 ph10 340 was subsequently set up correctly.)
829 ph10 345
830 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
831 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
832     other assertions are supported. I have made pcre_dfa_exec() support
833     (*FAIL).
834    
835 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
836 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
837     cannot be changed at match time, I realized I could make a small
838     improvement to matching performance by compiling OP_ALLANY instead of
839     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
840     on the OP_ANY path.
841    
842     17. Compiling pcretest on Windows with readline support failed without the
843 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
844 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
845    
846 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
847 ph10 345 ncurses library to be included for pcretest when ReadLine support is
848     requested, but also to allow for it to be overridden. This patch came from
849     Daniel Bergström.
850 ph10 347
851 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
852 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
853     any errors with the current Unicode tables. Thanks to Peter Kankowski for
854     spotting this.
855 ph10 324
856 ph10 332
857 ph10 319 Version 7.6 28-Jan-08
858 ph10 300 ---------------------
859    
860 ph10 302 1. A character class containing a very large number of characters with
861     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
862     overflow.
863 ph10 309
864     2. Patch to cut out the "long long" test in pcrecpp_unittest when
865     HAVE_LONG_LONG is not defined.
866    
867 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
868 ph10 304 bring them up to date and include new features. This patch includes:
869 ph10 309
870 ph10 304 - Fixed PH's badly added libz and libbz2 support.
871     - Fixed a problem with static linking.
872 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
873 ph10 304 - Fixed dftables problem and added an option.
874     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
875     HAVE_LONG_LONG.
876     - Added readline support for pcretest.
877 ph10 309 - Added an listing of the option settings after cmake has run.
878    
879 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
880     "pcre.dll" under mingw when using Configure/Make. I added stuff to
881     Makefile.am that cause it to include this special target, without
882     affecting anything else. Note that the same mingw target plus all
883     the other distribution libraries and programs are now supported
884     when configuring with CMake (see 6 below) instead of with
885     Configure/Make.
886 ph10 309
887 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
888     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
889 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
890     solves the problem, but it does no harm.
891 ph10 313
892 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
893 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
894 ph10 314 with CMake, and also correct the comment about stack recursion.
895 ph10 313
896 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
897 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
898     of a program that users should build themselves after PCRE is installed, so
899     building it automatically is not really right. What is more, it gave
900 ph10 312 trouble in some build environments.
901 ph10 300
902 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
903 ph10 308
904 ph10 319
905 ph10 298 Version 7.5 10-Jan-08
906 ph10 263 ---------------------
907    
908     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
909     values in parens when parsing an RE using the C++ wrapper."
910 ph10 286
911 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
912     Characters greater than 255 were excluded from the class instead of being
913     included.
914 ph10 286
915     3. The same bug as (2) above applied to negated POSIX classes such as
916 ph10 265 [:^space:].
917 ph10 286
918 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
919     defined or documented. It seems to have been a typo for PCRE_STATIC, so
920 ph10 286 I have changed it.
921    
922 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
923 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
924     first named subpattern whose name started with "a" (in other words, the
925 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
926     expected" is now given for (?&) (a zero-length name), and this patch also
927     makes it give the same error for \k'' (previously it complained that that
928     was a reference to a non-existent subpattern).
929 ph10 286
930 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
931 ph10 286 this is right because (?- can be followed by option settings as well as by
932 ph10 269 digits. I have, however, made the messages clearer.
933 ph10 286
934 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
935     than the number used in the conditional) now cause a compile-time error.
936     This is actually not compatible with Perl, which accepts such patterns, but
937     treats the conditional as always being FALSE (as PCRE used to), but it
938     seems to me that giving a diagnostic is better.
939 ph10 286
940 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
941 ph10 275 and messages.
942 ph10 286
943     9. Fix two occurrences of "backslash" in comments that should have been
944     "backspace".
945    
946     10. Remove two redundant lines of code that can never be obeyed (their function
947     was moved elsewhere).
948    
949     11. The program that makes PCRE's Unicode character property table had a bug
950     which caused it to generate incorrect table entries for sequences of
951 ph10 277 characters that have the same character type, but are in different scripts.
952 ph10 286 It amalgamated them into a single range, with the script of the first of
953 ph10 277 them. In other words, some characters were in the wrong script. There were
954     thirteen such cases, affecting characters in the following ranges:
955 ph10 286
956 ph10 277 U+002b0 - U+002c1
957     U+0060c - U+0060d
958 ph10 286 U+0061e - U+00612
959 ph10 277 U+0064b - U+0065e
960     U+0074d - U+0076d
961     U+01800 - U+01805
962     U+01d00 - U+01d77
963     U+01d9b - U+01dbf
964     U+0200b - U+0200f
965     U+030fc - U+030fe
966     U+03260 - U+0327f
967     U+0fb46 - U+0fbb1
968     U+10450 - U+1049d
969 ph10 286
970 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
971     compatible with GNU grep in that, if there was more than one match in a
972     line, it showed only the first of them. It now behaves in the same way as
973     GNU grep.
974 ph10 286
975     13. If the -o and -v options were combined for pcregrep, it printed a blank
976     line for every non-matching line. GNU grep prints nothing, and pcregrep now
977     does the same. The return code can be used to tell if there were any
978     non-matching lines.
979    
980 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
981    
982     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
983 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
984 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
985     and both kinds of lookbehind were skipped).
986    
987 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
988 ph10 284 inclusion of <windows.h> to before rather than after the definition of
989     INVALID_FILE_ATTRIBUTES (patch from David Byron).
990 ph10 263
991 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
992 ph10 286 character property caused pcre_compile() to compile bad code, which led at
993     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
994     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
995     caused the error; without that there was no problem.
996 ph10 263
997 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
998 ph10 286
999 ph10 289 19. Added --enable-pcretest-libreadline.
1000 ph10 286
1001 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1002 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
1003 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
1004     later patch that removed the other one (the right fix) and added unit tests
1005     that check the return values (which was not done before).
1006 ph10 292
1007 ph10 291 21. Several CMake things:
1008 ph10 287
1009 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1010 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
1011 ph10 288
1012 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
1013     linked with the newly-built libraries, not previously installed ones.
1014 ph10 291
1015 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1016 ph10 298
1017     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1018     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1019     UTF-8 newline character). The key issue is that the pattern starts .*;
1020     this means that the match must be either at the beginning, or after a
1021     newline. The bug was in the code for advancing after a failed match and
1022     checking that the new position followed a newline. It was not taking
1023 ph10 294 account of UTF-8 characters correctly.
1024 ph10 298
1025     23. PCRE was behaving differently from Perl in the way it recognized POSIX
1026     character classes. PCRE was not treating the sequence [:...:] as a
1027     character class unless the ... were all letters. Perl, however, seems to
1028     allow any characters between [: and :], though of course it rejects as
1029     unknown any "names" that contain non-letters, because all the known class
1030     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1031     for example, whereas PCRE did not - it did not recognize a POSIX character
1032     class. This seemed a bit dangerous, so the code has been changed to be
1033     closer to Perl. The behaviour is not identical to Perl, because PCRE will
1034     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1035     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1036     Perl does, and where it didn't before.
1037    
1038 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1039     Windows environments %n is disabled by default.
1040 ph10 292
1041    
1042 ph10 260 Version 7.4 21-Sep-07
1043 ph10 230 ---------------------
1044    
1045     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1046 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
1047     LF". That isn't really right - the whole point of the change was to try to
1048     help when there was an actual mention of one of the two characters. So now
1049     the change happens only if \r or \n (or a literal CR or LF) character is
1050 ph10 230 encountered.
1051 ph10 231
1052     2. The 32-bit options word was also used for 6 internal flags, but the numbers
1053     of both had grown to the point where there were only 3 bits left.
1054     Fortunately, there was spare space in the data structure, and so I have
1055     moved the internal flags into a new 16-bit field to free up more option
1056 ph10 230 bits.
1057 ph10 231
1058     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1059     but did not set the internal JCHANGED flag - either of these is enough to
1060     control the way the "get" function works - but the PCRE_INFO_JCHANGED
1061     facility is supposed to tell if (?J) was ever used, so now (?J) at the
1062 ph10 230 start sets both bits.
1063    
1064 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
1065     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1066 ph10 230
1067 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
1068    
1069     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1070 ph10 233 compatibility, even though it is no longer used.
1071 ph10 243
1072     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1073 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1074 ph10 259 windows.h file is present (where different names are used). [This was
1075 ph10 257 reversed later after testing - see 16 below.]
1076 ph10 243
1077     8. Changed all #include <config.h> to #include "config.h". There were also
1078 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
1079 ph10 243
1080 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
1081 ph10 243 sequence off the lines that it output.
1082    
1083     10. It was pointed out to me that arrays of string pointers cause lots of
1084     relocations when a shared library is dynamically loaded. A technique of
1085     using a single long string with a table of offsets can drastically reduce
1086     these. I have refactored PCRE in four places to do this. The result is
1087 ph10 240 dramatic:
1088 ph10 243
1089 ph10 240 Originally: 290
1090     After changing UCP table: 187
1091 ph10 243 After changing error message table: 43
1092 ph10 240 After changing table of "verbs" 36
1093     After changing table of Posix names 22
1094 ph10 243
1095 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
1096 ph10 247
1097 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1098 ph10 247 unicode-properties was also set.
1099    
1100 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1101 ph10 231
1102 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1103     checked only for CRLF.
1104 ph10 233
1105 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
1106    
1107 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1108 ph10 253
1109 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1110 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1111     entirely. This removes changes made in 7 above.
1112 ph10 256
1113 ph10 261 17. The CMake files have been updated, and there is now more information about
1114     building with CMake in the NON-UNIX-USE document.
1115 ph10 257
1116 ph10 261
1117 ph10 228 Version 7.3 28-Aug-07
1118 ph10 157 ---------------------
1119    
1120 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
1121     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1122     brackets there is not right, since it causes compilers to look for an
1123     installed pcre.h, not the version that is in the source that is being
1124     compiled (which of course may be different). I have changed it back to:
1125 ph10 197
1126 ph10 189 #include "pcre.h"
1127 ph10 197
1128     I have a vague recollection that the change was concerned with compiling in
1129     different directories, but in the new build system, that is taken care of
1130     by the VPATH setting the Makefile.
1131    
1132 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1133     when the subject happened to end in the byte 0x85 (e.g. if the last
1134     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1135     characters but of course it shouldn't be taken as a newline when it is part
1136     of another character. The bug was that, for an unlimited repeat of . in
1137     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1138     characters when looking for a newline.
1139 ph10 197
1140     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1141    
1142     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1143     in debug output.
1144    
1145 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1146     long printing in the pcrecpp unittest when running under MinGW.
1147 ph10 189
1148 ph10 197 6. ESC_K was left out of the EBCDIC table.
1149 ph10 189
1150 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1151     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1152     limit also applies to "virtual nesting" when a pattern is recursive, and in
1153     this case 1000 isn't so big. I have been able to remove this limit at the
1154     expense of backing off one optimization in certain circumstances. Normally,
1155     when pcre_exec() would call its internal match() function recursively and
1156     immediately return the result unconditionally, it uses a "tail recursion"
1157     feature to save stack. However, when a subpattern that can match an empty
1158     string has an unlimited repetition quantifier, it no longer makes this
1159     optimization. That gives it a stack frame in which to save the data for
1160     checking that an empty string has been matched. Previously this was taken
1161     from the 1000-entry workspace that had been reserved. So now there is no
1162     explicit limit, but more stack is used.
1163 ph10 189
1164 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
1165     syntax that is required for Windows, and which was going wrong for the
1166     pcreposix and pcrecpp parts of the library. These were overlooked when this
1167     problem was solved for the main library.
1168 ph10 197
1169 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
1170     the size of patterns that contain repeated groups with explicit upper
1171     limits. As the maximum quantifier is 65535, the maximum group length was
1172     set at 30,000 so that the product of these two numbers did not overflow a
1173     32-bit integer. However, it turns out that people want to use groups that
1174     are longer than 30,000 bytes (though not repeat them that many times).
1175     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1176     made it possible to implement the integer overflow checks in a much more
1177     dynamic way, which I have now done. The artificial limitation on group
1178     length has been removed - we now have only the limit on the total length of
1179     the compiled pattern, which depends on the LINK_SIZE setting.
1180 ph10 208
1181     10. Fixed a bug in the documentation for get/copy named substring when
1182     duplicate names are permitted. If none of the named substrings are set, the
1183     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1184     empty string.
1185    
1186     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1187     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1188     because the ] is interpreted as the first data character and the
1189     terminating ] is not found. PCRE has been made compatible with Perl in this
1190     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1191     cause memory overwriting.
1192    
1193 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1194     string has been matched (to stop an infinite loop). It was not recognizing
1195 ph10 208 a conditional subpattern that could match an empty string if that
1196 ph10 206 subpattern was within another subpattern. For example, it looped when
1197 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1198 ph10 206 condition was not nested. This bug has been fixed.
1199 ph10 208
1200 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1201     past the start of the subject in the presence of bytes with the top bit
1202     set, for example "\x8aBCD".
1203 ph10 211
1204 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1205     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1206 ph10 200
1207 ph10 211 14. Optimized (?!) to (*FAIL).
1208 ph10 202
1209 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1210     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1211     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1212     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1213     does: it's just the validity check that is more restrictive.
1214 ph10 220
1215     16. Inserted checks for integer overflows during escape sequence (backslash)
1216     processing, and also fixed erroneous offset values for syntax errors during
1217     backslash processing.
1218    
1219 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1220 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1221    
1222 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1223     caused an overrun.
1224 ph10 220
1225     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1226     something other than just ASCII characters) inside a group that had an
1227     unlimited repeat caused a loop at compile time (while checking to see
1228     whether the group could match an empty string).
1229    
1230 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1231     [\P{Any}] did so. (Error in the code for printing property names.)
1232 ph10 210
1233 ph10 220 21. An orphan \E inside a character class could cause a crash.
1234    
1235     22. A repeated capturing bracket such as (A)? could cause a wild memory
1236 ph10 218 reference during compilation.
1237 ph10 220
1238     23. There are several functions in pcre_compile() that scan along a compiled
1239     expression for various reasons (e.g. to see if it's fixed length for look
1240 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1241 ph10 220 present in the pattern. These operators have additional parameters compared
1242     with \d, etc, and these were not being taken into account when moving along
1243 ph10 218 the compiled data. Specifically:
1244 ph10 220
1245     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1246     length.
1247    
1248     (b) An item such as \pL+ within a repeated group could cause crashes or
1249 ph10 218 loops.
1250 ph10 220
1251 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1252 ph10 220 "reference to non-existent subpattern" error.
1253    
1254 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1255    
1256 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1257 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1258 ph10 211
1259 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1260 ph10 218
1261 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1262 ph10 223 character were causing crashes (broken optimization).
1263 ph10 227
1264 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1265 ph10 227 \p or \P) caused a compile-time loop.
1266    
1267 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1268     break. For example, the unstudied pattern [\r\n]A does not match the string
1269     "\r\nA" because change 7.0/46 below moves the current point on by two
1270     characters after failing to match at the start. However, the pattern \nA
1271 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1272     the same is true. There doesn't seem any very clean way out of this, but
1273     what I have chosen to do makes the common cases work: PCRE now takes note
1274     of whether there can be an explicit match for \r or \n anywhere in the
1275     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1276     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1277     pattern has explicit CR or LF references.
1278 ph10 222
1279 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1280 ph10 223
1281 ph10 227
1282 ph10 189 Version 7.2 19-Jun-07
1283     ---------------------
1284    
1285 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1286     which is apparently normally available under Windows.
1287 ph10 159
1288     2. Re-jig the pcregrep tests with different newline settings in an attempt
1289     to make them independent of the local environment's newline setting.
1290 ph10 157
1291 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1292 ph10 165
1293 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1294     was not 2, because the output contained actual offsets. The recent new
1295 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1296     usable with all link sizes.
1297    
1298 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1299     stack recursion. This gives a massive performance boost under BSD, but just
1300 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1301 ph10 164 in all cases.
1302 ph10 172
1303 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1304 ph10 172
1305 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1306     recursion call. It refers to the nth most recently opened parentheses.
1307 ph10 172
1308 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1309 ph10 172 to be opened parentheses.
1310    
1311     (c) Conditions that refer to capturing parentheses can be specified
1312 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1313 ph10 172
1314 ph10 168 (d) \K resets the start of the current match so that everything before
1315 ph10 172 is not part of it.
1316    
1317 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1318 ph10 172
1319 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1320 ph10 172 reference syntax.
1321 ph10 182
1322 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1323 ph10 182 alternative starts with the same number.
1324 ph10 172
1325 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1326    
1327 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1328     PCRE_INFO_JCHANGED.
1329    
1330     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1331     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1332 ph10 170 for detecting groups that can match an empty string.
1333 ph10 159
1334 ph10 172 9. A pattern with a very large number of alternatives (more than several
1335     hundred) was running out of internal workspace during the pre-compile
1336     phase, where pcre_compile() figures out how much memory will be needed. A
1337     bit of new cunning has reduced the workspace needed for groups with
1338     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1339     workspace instead of running out of the 4096 that are available.
1340 ph10 182
1341 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1342 ph10 172
1343 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1344     The report of the bug said:
1345 ph10 182
1346 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1347     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1348 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1349 ph10 185
1350 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1351 ph10 185 it matched the wrong number of bytes.
1352 ph10 172
1353 ph10 179
1354 ph10 155 Version 7.1 24-Apr-07
1355 ph10 98 ---------------------
1356    
1357 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1358 ph10 122 that is more "standard", making use of automake and other Autotools. There
1359 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1360     on this.
1361 ph10 111
1362     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1363     for recursive directory scanning broke on some systems because the files
1364     are not scanned in any specific order and on different systems the order
1365     was different. A call to "sort" has been inserted into RunGrepTest for the
1366     approprate test as a short-term fix. In the longer term there may be an
1367 ph10 100 alternative.
1368 ph10 111
1369 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1370 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1371     people do their own conversions for various reasons). The problems
1372     concerned the use of low-level troff macros .br and .in. I have therefore
1373     removed all such uses from the man pages (some were redundant, some could
1374 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1375     HTML has been updated to handle .nf/.fi and to complain if it encounters
1376     .br or .in.
1377 ph10 111
1378 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1379 ph10 123 arranged for config.h to be included in the distribution, with the name
1380 ph10 111 config.h.generic, for the benefit of those who have to compile without
1381     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1382    
1383     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1384     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1385 ph10 127 makevp.bat for the current PCRE, using the additional files
1386 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1387 ph10 111
1388     6. A Windows user reported a minor discrepancy with test 2, which turned out
1389     to be caused by a trailing space on an input line that had got lost in his
1390 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1391 ph10 111
1392 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1393 ph10 111 that is needed.
1394    
1395 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1396     as "const" (a) because they are and (b) because it helps the PHP
1397     maintainers who have recently made a script to detect big data structures
1398 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1399     to update Builducptable as well, so it won't revert if ucptable.h is ever
1400 ph10 105 re-created.
1401 ph10 111
1402     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1403 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1404 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1405     support is not required. This saves 1.5-2K of code, which is important in
1406 ph10 107 some applications.
1407 ph10 111
1408 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1409 ph10 111 so as not to refer to the tables, even though these functions will never be
1410     called when UTF-8 support is disabled. Otherwise there are problems with a
1411     shared library.
1412    
1413 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1414    
1415     (a) It was defining its arguments as char * instead of void *.
1416    
1417 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1418     a long time ago when I wrote it, but is no longer the case.
1419    
1420 ph10 118 The emulated memove() is provided for those environments that have neither
1421 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1422 ph10 118 is clearly not the case, as these two bugs were recently reported.
1423 ph10 123
1424 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1425 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1426     pages, and it removes trailing spaces from listed files. It also creates
1427     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1428     case, it wraps all the #defines with #ifndefs. This script should be run
1429 ph10 111 before "make dist".
1430 ph10 123
1431 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1432     with Unicode property support.
1433 ph10 123
1434     (a) For a maximizing quantifier, if the two different cases of the
1435     character were of different lengths in their UTF-8 codings (there are
1436     some cases like this - I found 11), and the matching function had to
1437 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1438     were both the same length.
1439 ph10 123
1440     (b) When PCRE was configured to use the heap rather than the stack for
1441     recursion during matching, it was not correctly preserving the data for
1442     the other case of a UTF-8 character when checking ahead for a match
1443     while processing a minimizing repeat. If the check also involved
1444 ph10 115 matching a wide character, but failed, corruption could cause an
1445     erroneous result when trying to check for a repeat of the original
1446     character.
1447 ph10 123
1448 ph10 116 13. Some tidying changes to the testing mechanism:
1449 ph10 98
1450 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1451     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1452 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1453     this for UTF-8.) The configure.ac script no longer substitutes the
1454     relevant variables.
1455    
1456 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1457     with length and offset values. This means that the output is different
1458     for different internal link sizes. Test 2 is skipped for link sizes
1459     other than 2 because of this, bypassing the problem. Unfortunately,
1460     there was also a test in test 3 (the locale tests) that used /B and
1461 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1462     I have added a new /Z option to pcretest that replaces the length and
1463     offset values with spaces. This is now used to make test 3 independent
1464 ph10 122 of link size. (Test 2 will be tidied up later.)
1465 ph10 123
1466     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1467 ph10 122 segmentation fault instead of returning the appropriate error message.
1468 ph10 134
1469 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1470 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1471     This doesn't seem right; it now treats the CRLF combination as the line
1472     ending, and so does not match in that case. It's only a pattern such as ^$
1473     that would hit this one: something like ^ABC$ would have failed after \r
1474     and then tried again after \r\n.
1475    
1476 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1477 ph10 134 in an attempt to make files that differ only in their line terminators
1478     compare equal. This works on Linux.
1479 ph10 142
1480 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1481     as it exited. This is now fixed, thanks to valgrind.
1482 ph10 142
1483 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1484 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1485     was because its rules for how to advance for /g after matching an empty
1486 ph10 143 string at the end of a line did not allow for this case. They now check for
1487     it specially.
1488 ph10 150
1489     20. pcretest is supposed to handle patterns and data of any length, by
1490     extending its buffers when necessary. It was getting this wrong when the
1491 ph10 147 buffer for a data line had to be extended.
1492 ph10 150
1493 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1494 ph10 150 CRLF as a newline sequence.
1495 ph10 152
1496 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1497 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1498     I have nevertheless tidied it up.
1499 ph10 111
1500 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1501 ph10 123
1502 ph10 153 24. Added a man page for pcre-config.
1503 ph10 152
1504 ph10 153
1505 nigel 93 Version 7.0 19-Dec-06
1506     ---------------------
1507    
1508     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1509     moving to gcc 4.1.1.
1510    
1511     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1512     sys/time.h, which is documented as needed for this function. It doesn't
1513     seem to matter on Linux, but it showed up on some releases of OS X.
1514    
1515     3. It seems that there are systems where bytes whose values are greater than
1516     127 match isprint() in the "C" locale. The "C" locale should be the
1517     default when a C program starts up. In most systems, only ASCII printing
1518     characters match isprint(). This difference caused the output from pcretest
1519     to vary, making some of the tests fail. I have changed pcretest so that:
1520    
1521     (a) When it is outputting text in the compiled version of a pattern, bytes
1522     other than 32-126 are always shown as hex escapes.
1523    
1524     (b) When it is outputting text that is a matched part of a subject string,
1525     it does the same, unless a different locale has been set for the match
1526     (using the /L modifier). In this case, it uses isprint() to decide.
1527    
1528     4. Fixed a major bug that caused incorrect computation of the amount of memory
1529     required for a compiled pattern when options that changed within the
1530     pattern affected the logic of the preliminary scan that determines the
1531     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1532     that the computed length was too small. The symptoms of this bug were
1533     either the PCRE error "internal error: code overflow" from pcre_compile(),
1534     or a glibc crash with a message such as "pcretest: free(): invalid next
1535     size (fast)". Examples of patterns that provoked this bug (shown in
1536     pcretest format) are:
1537    
1538     /(?-x: )/x
1539     /(?x)(?-x: \s*#\s*)/
1540     /((?i)[\x{c0}])/8
1541     /(?i:[\x{c0}])/8
1542    
1543     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1544     is now done differently.
1545    
1546     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1547     wrapper classes; (b) implement a new function in the C++ scanner that is
1548     more efficient than the old way of doing things because it avoids levels of
1549     recursion in the regex matching; (c) add a paragraph to the documentation
1550     for the FullMatch() function.
1551    
1552     6. The escape sequence \n was being treated as whatever was defined as
1553     "newline". Not only was this contrary to the documentation, which states
1554     that \n is character 10 (hex 0A), but it also went horribly wrong when
1555     "newline" was defined as CRLF. This has been fixed.
1556    
1557     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1558     was being set to -1 for the "end of line" case (supposedly a value that no
1559     character can have). Though this value is never used (the check for end of
1560     line is "zero bytes in current character"), it caused compiler complaints.
1561     I've changed it to 0xffffffff.
1562    
1563     8. In pcre_version.c, the version string was being built by a sequence of
1564     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1565     string (as it is for production releases) called a macro with an empty
1566     argument. The C standard says the result of this is undefined. The gcc
1567     compiler treats it as an empty string (which was what was wanted) but it is
1568     reported that Visual C gives an error. The source has been hacked around to
1569     avoid this problem.
1570    
1571     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1572     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1573     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1574     of them did).
1575    
1576     10. Originally, pcretest opened its input and output without "b"; then I was
1577     told that "b" was needed in some environments, so it was added for release
1578     5.0 to both the input and output. (It makes no difference on Unix-like
1579     systems.) Later I was told that it is wrong for the input on Windows. I've
1580     now abstracted the modes into two macros, to make it easier to fiddle with
1581     them, and removed "b" from the input mode under Windows.
1582    
1583     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1584    
1585     12. Added -help and --help to pcretest as an official way of being reminded
1586     of the options.
1587    
1588     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1589     and pcrecpp.cc because they annoy compilers at high warning levels.
1590    
1591     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1592    
1593     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1594     scripts are not C programs :-) and which was not noticed because it works
1595     on Linux.
1596    
1597     16. pcretest is supposed to handle any length of pattern and data line (as one
1598     line or as a continued sequence of lines) by extending its input buffer if
1599     necessary. This feature was broken for very long pattern lines, leading to
1600     a string of junk being passed to pcre_compile() if the pattern was longer
1601     than about 50K.
1602    
1603     17. I have done a major re-factoring of the way pcre_compile() computes the
1604     amount of memory needed for a compiled pattern. Previously, there was code
1605     that made a preliminary scan of the pattern in order to do this. That was
1606     OK when PCRE was new, but as the facilities have expanded, it has become
1607     harder and harder to keep it in step with the real compile phase, and there
1608     have been a number of bugs (see for example, 4 above). I have now found a
1609     cunning way of running the real compile function in a "fake" mode that
1610     enables it to compute how much memory it would need, while actually only
1611     ever using a few hundred bytes of working memory and without too many
1612     tests of the mode. This should make future maintenance and development
1613     easier. A side effect of this work is that the limit of 200 on the nesting
1614     depth of parentheses has been removed (though this was never a serious
1615     limitation, I suspect). However, there is a downside: pcre_compile() now
1616     runs more slowly than before (30% or more, depending on the pattern). I
1617     hope this isn't a big issue. There is no effect on runtime performance.
1618    
1619     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1620     newline (only possible for the last line of a file) and it was a
1621     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1622    
1623     19. Added additional timing features to pcretest. (1) The -tm option now times
1624     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1625     separate command line item, by a number that specifies the number of
1626     repeats to use when timing. The default is 50000; this gives better
1627     precision, but takes uncomfortably long for very large patterns.
1628    
1629     20. Extended pcre_study() to be more clever in cases where a branch of a
1630     subpattern has no definite first character. For example, (a*|b*)[cd] would
1631     previously give no result from pcre_study(). Now it recognizes that the
1632     first character must be a, b, c, or d.
1633    
1634     21. There was an incorrect error "recursive call could loop indefinitely" if
1635     a subpattern (or the entire pattern) that was being tested for matching an
1636     empty string contained only one non-empty item after a nested subpattern.
1637     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1638     incorrectly, because the \d was being skipped in the check.
1639    
1640     22. The pcretest program now has a new pattern option /B and a command line
1641     option -b, which is equivalent to adding /B to every pattern. This causes
1642     it to show the compiled bytecode, without the additional information that
1643     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1644     is the same as /B/I).
1645    
1646     23. A new optimization is now able automatically to treat some sequences such
1647     as a*b as a*+b. More specifically, if something simple (such as a character
1648     or a simple class like \d) has an unlimited quantifier, and is followed by
1649     something that cannot possibly match the quantified thing, the quantifier
1650     is automatically "possessified".
1651    
1652     24. A recursive reference to a subpattern whose number was greater than 39
1653     went wrong under certain circumstances in UTF-8 mode. This bug could also
1654     have affected the operation of pcre_study().
1655    
1656     25. Realized that a little bit of performance could be had by replacing
1657     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1658    
1659     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1660    
1661     27. Possessive quantifiers such as a++ were previously implemented by turning
1662     them into atomic groups such as ($>a+). Now they have their own opcodes,
1663     which improves performance. This includes the automatically created ones
1664     from 23 above.
1665    
1666     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1667     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1668     the first matched character to be a colon. This applied both to named and
1669     numbered groups.
1670    
1671     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1672    
1673     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1674     building PCRE on Windows easier, so I have included it in the distribution.
1675    
1676     31. There is now a check in pcretest against a ridiculously large number being
1677     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1678     loop, the loop is abandoned.
1679    
1680     32. Forward references to subpatterns in conditions such as (?(2)...) where
1681     subpattern 2 is defined later cause pcre_compile() to search forwards in
1682     the pattern for the relevant set of parentheses. This search went wrong
1683     when there were unescaped parentheses in a character class, parentheses
1684     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1685    
1686     33. "Subroutine" calls and backreferences were previously restricted to
1687     referencing subpatterns earlier in the regex. This restriction has now
1688     been removed.
1689    
1690     34. Added a number of extra features that are going to be in Perl 5.10. On the
1691     whole, these are just syntactic alternatives for features that PCRE had
1692     previously implemented using the Python syntax or my own invention. The
1693     other formats are all retained for compatibility.
1694    
1695     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1696     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1697     also .NET compatible.
1698    
1699     (b) A recursion or subroutine call to a named group can now be defined as
1700     (?&name) as well as (?P>name).
1701    
1702     (c) A backreference to a named group can now be defined as \k<name> or
1703     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1704     5.10, are also .NET compatible.
1705    
1706     (d) A conditional reference to a named group can now use the syntax
1707     (?(<name>) or (?('name') as well as (?(name).
1708    
1709     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1710     groups (named and numbered) that are never evaluated inline, but can be
1711     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1712     is always false. There may be only one alternative in such a group.
1713    
1714     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1715     as the simple (?(R). The condition is true only if the most recent
1716     recursion is that of the given number or name. It does not search out
1717     through the entire recursion stack.
1718    
1719     (g) The escape \gN or \g{N} has been added, where N is a positive or
1720     negative number, specifying an absolute or relative reference.
1721    
1722     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1723     some "unreachable code" warnings.
1724    
1725     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1726     things, this adds five new scripts.
1727    
1728     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1729     There were also incompatibilities regarding the handling of \Q..\E inside
1730     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1731     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1732    
1733     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1734     matches an empty string, and forcibly breaks the loop. There were bugs in
1735     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1736     against aaaa the result was just "a" rather than "aaaa", for example. Two
1737     separate and independent bugs (that affected different cases) have been
1738     fixed.
1739    
1740     39. Refactored the code to abolish the use of different opcodes for small
1741     capturing bracket numbers. This is a tidy that I avoided doing when I
1742     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1743     The new approach is not only tidier, it makes it possible to reduce the
1744     memory needed to fix the previous bug (38).
1745    
1746     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1747     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1748     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1749     mode.
1750    
1751     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1752     report.
1753    
1754     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1755     copy construction and assignment in the C++ wrapper.
1756    
1757     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1758     couple of bugs that could have given wrong results in the "--newline=crlf"
1759     case.
1760    
1761     44. Added a number of casts and did some reorganization of signed/unsigned int
1762     variables following suggestions from Dair Grant. Also renamed the variable
1763     "this" as "item" because it is a C++ keyword.
1764    
1765     45. Arranged for dftables to add
1766    
1767     #include "pcre_internal.h"
1768    
1769     to pcre_chartables.c because without it, gcc 4.x may remove the array
1770     definition from the final binary if PCRE is built into a static library and
1771     dead code stripping is activated.
1772    
1773     46. For an unanchored pattern, if a match attempt fails at the start of a
1774     newline sequence, and the newline setting is CRLF or ANY, and the next two
1775     characters are CRLF, advance by two characters instead of one.
1776    
1777    
1778 nigel 91 Version 6.7 04-Jul-06
1779     ---------------------
1780    
1781     1. In order to handle tests when input lines are enormously long, pcretest has
1782     been re-factored so that it automatically extends its buffers when
1783     necessary. The code is crude, but this _is_ just a test program. The
1784     default size has been increased from 32K to 50K.
1785    
1786     2. The code in pcre_study() was using the value of the re argument before
1787     testing it for NULL. (Of course, in any sensible call of the function, it
1788     won't be NULL.)
1789    
1790     3. The memmove() emulation function in pcre_internal.h, which is used on
1791     systems that lack both memmove() and bcopy() - that is, hardly ever -
1792     was missing a "static" storage class specifier.
1793    
1794     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1795     containing an extended class (one that cannot be represented by a bitmap
1796     because it contains high-valued characters or Unicode property items, e.g.
1797     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1798     pattern, but PCRE should not loop if you do not (it no longer does).
1799     [Detail: two cases were found: (a) a repeated subpattern containing an
1800     extended class; (b) a recursive reference to a subpattern that followed a
1801     previous extended class. It wasn't skipping over the extended class
1802     correctly when UTF-8 mode was not set.]
1803    
1804     5. A negated single-character class was not being recognized as fixed-length
1805     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1806     compile error "lookbehind assertion is not fixed length".
1807    
1808     6. The RunPerlTest auxiliary script was showing an unexpected difference
1809     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1810     write a Perl script that can interpret lines of an input file either as
1811     byte characters or as UTF-8, which is what "perltest" was being required to
1812     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1813     can't do is switch easily at run time between having the "use utf8;" pragma
1814     or not. In the end, I fudged it by using the RunPerlTest script to insert
1815     "use utf8;" explicitly for the UTF-8 tests.
1816    
1817     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1818     the end of the subject string, contrary to the documentation and to what
1819     Perl does. This was true of both matching functions. Now it matches only at
1820     the start of the subject and immediately after *internal* newlines.
1821    
1822     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1823     a pointer to an int instead of a pointer to an unsigned long int. This
1824     caused problems on 64-bit systems.
1825    
1826     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1827     instance of the 'standard' template library not being so standard".
1828    
1829     10. There was no check on the number of named subpatterns nor the maximum
1830     length of a subpattern name. The product of these values is used to compute
1831     the size of the memory block for a compiled pattern. By supplying a very
1832     long subpattern name and a large number of named subpatterns, the size
1833     computation could be caused to overflow. This is now prevented by limiting
1834     the length of names to 32 characters, and the number of named subpatterns
1835     to 10,000.
1836    
1837     11. Subpatterns that are repeated with specific counts have to be replicated in
1838     the compiled pattern. The size of memory for this was computed from the
1839     length of the subpattern and the repeat count. The latter is limited to
1840     65535, but there was no limit on the former, meaning that integer overflow
1841     could in principle occur. The compiled length of a repeated subpattern is
1842     now limited to 30,000 bytes in order to prevent this.
1843    
1844     12. Added the optional facility to have named substrings with the same name.
1845    
1846     13. Added the ability to use a named substring as a condition, using the
1847     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1848     are numbers (not recommended). Forward references are permitted.
1849    
1850     14. Added forward references in named backreferences (if you see what I mean).
1851    
1852     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1853     pattern could run off the end of the subject. For example, the pattern
1854     "(?s)(.{1,5})"8 did this with the subject "ab".
1855    
1856     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1857     PCRE_CASELESS was set when matching characters that were quantified with ?
1858     or *.
1859    
1860     17. A character class other than a single negated character that had a minimum
1861     but no maximum quantifier - for example [ab]{6,} - was not handled
1862     correctly by pce_dfa_exec(). It would match only one character.
1863    
1864     18. A valid (though odd) pattern that looked like a POSIX character
1865     class but used an invalid character after [ (for example [[,abc,]]) caused
1866     pcre_compile() to give the error "Failed: internal error: code overflow" or
1867     in some cases to crash with a glibc free() error. This could even happen if
1868     the pattern terminated after [[ but there just happened to be a sequence of
1869     letters, a binary zero, and a closing ] in the memory that followed.
1870    
1871     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1872     over the years. Originally (before any Unicode support), just the bottom 8
1873     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1874     output from "man perlunicode" includes this:
1875    
1876     The regular expression compiler produces polymorphic opcodes. That
1877     is, the pattern adapts to the data and automatically switches to
1878     the Unicode character scheme when presented with Unicode data--or
1879     instead uses a traditional byte scheme when presented with byte
1880     data.
1881    
1882     Sadly, a wide octal escape does not cause a switch, and in a string with
1883     no other multibyte characters, these octal escapes are treated as before.
1884     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1885     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1886     Unicode string.
1887    
1888     I have not perpetrated such confusion in PCRE. Up till now, it took just
1889     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1890     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1891     translate to the appropriate multibyte character.
1892    
1893     29. Applied some refactoring to reduce the number of warnings from Microsoft
1894     and Borland compilers. This has included removing the fudge introduced
1895     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1896     a warning about an unused variable.
1897    
1898     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1899     characters since release 4.0, because Perl (from release 5.004) does not.
1900     [Or at least, is documented not to: some releases seem to be in conflict
1901     with the documentation.] However, when a pattern was studied with
1902     pcre_study() and all its branches started with \s, PCRE still included VT
1903     as a possible starting character. Of course, this did no harm; it just
1904     caused an unnecessary match attempt.
1905    
1906     22. Removed a now-redundant internal flag bit that recorded the fact that case
1907     dependency changed within the pattern. This was once needed for "required
1908     byte" processing, but is no longer used. This recovers a now-scarce options
1909     bit. Also moved the least significant internal flag bit to the most-
1910     significant bit of the word, which was not previously used (hangover from
1911     the days when it was an int rather than a uint) to free up another bit for
1912     the future.
1913    
1914     23. Added support for CRLF line endings as well as CR and LF. As well as the
1915     default being selectable at build time, it can now be changed at runtime
1916     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1917     specify that it is scanning data with non-default line endings.
1918    
1919     24. Changed the definition of CXXLINK to make it agree with the definition of
1920     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1921    
1922     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1923     recursions. This makes a big different to stack usage for some patterns.
1924    
1925     26. If a subpattern containing a named recursion or subroutine reference such
1926     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1927     the space required for the compiled pattern went wrong and gave too small a
1928     value. Depending on the environment, this could lead to "Failed: internal
1929     error: code overflow at offset 49" or "glibc detected double free or
1930     corruption" errors.
1931    
1932     27. Applied patches from Google (a) to support the new newline modes and (b) to
1933     advance over multibyte UTF-8 characters in GlobalReplace.
1934    
1935     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1936     difference for some implementation of PCRE in some Windows version.
1937    
1938     29. Added some extra testing facilities to pcretest:
1939    
1940     \q<number> in a data line sets the "match limit" value
1941     \Q<number> in a data line sets the "match recursion limt" value
1942     -S <number> sets the stack size, where <number> is in megabytes
1943    
1944     The -S option isn't available for Windows.
1945    
1946    
1947 nigel 89 Version 6.6 06-Feb-06
1948     ---------------------
1949    
1950     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1951     in pcreposix.h. I have copied the definition from pcre.h.
1952    
1953     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1954     because pcre.h is no longer a built file.
1955    
1956     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1957     not normally included in the compiled code.
1958    
1959    
1960 nigel 87 Version 6.5 01-Feb-06
1961     ---------------------
1962    
1963     1. When using the partial match feature with pcre_dfa_exec(), it was not
1964     anchoring the second and subsequent partial matches at the new starting
1965     point. This could lead to incorrect results. For example, with the pattern
1966     /1234/, partially matching against "123" and then "a4" gave a match.
1967    
1968     2. Changes to pcregrep:
1969    
1970     (a) All non-match returns from pcre_exec() were being treated as failures
1971     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1972     error message is output. Some extra information is given for the
1973     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1974     probably the only errors that are likely to be caused by users (by
1975     specifying a regex that has nested indefinite repeats, for instance).
1976     If there are more than 20 of these errors, pcregrep is abandoned.
1977    
1978     (b) A binary zero was treated as data while matching, but terminated the
1979     output line if it was written out. This has been fixed: binary zeroes
1980     are now no different to any other data bytes.
1981    
1982     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1983     used to set a locale for matching. The --locale=xxxx long option has
1984     been added (no short equivalent) to specify a locale explicitly on the
1985     pcregrep command, overriding the environment variables.
1986    
1987     (d) When -B was used with -n, some line numbers in the output were one less
1988     than they should have been.
1989    
1990     (e) Added the -o (--only-matching) option.
1991    
1992     (f) If -A or -C was used with -c (count only), some lines of context were
1993     accidentally printed for the final match.
1994    
1995     (g) Added the -H (--with-filename) option.
1996    
1997     (h) The combination of options -rh failed to suppress file names for files
1998     that were found from directory arguments.
1999    
2000     (i) Added the -D (--devices) and -d (--directories) options.
2001    
2002     (j) Added the -F (--fixed-strings) option.
2003    
2004     (k) Allow "-" to be used as a file name for -f as well as for a data file.
2005    
2006     (l) Added the --colo(u)r option.
2007    
2008     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2009     is not present by default.
2010    
2011     3. A nasty bug was discovered in the handling of recursive patterns, that is,
2012     items such as (?R) or (?1), when the recursion could match a number of
2013     alternatives. If it matched one of the alternatives, but subsequently,
2014     outside the recursion, there was a failure, the code tried to back up into
2015     the recursion. However, because of the way PCRE is implemented, this is not
2016     possible, and the result was an incorrect result from the match.
2017    
2018     In order to prevent this happening, the specification of recursion has
2019     been changed so that all such subpatterns are automatically treated as
2020     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2021    
2022     4. I had overlooked the fact that, in some locales, there are characters for
2023     which isalpha() is true but neither isupper() nor islower() are true. In
2024     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2025     and ordfeminine) are like this. This affected the treatment of \w and \W
2026     when they appeared in character classes, but not when they appeared outside
2027     a character class. The bit map for "word" characters is now created
2028     separately from the results of isalnum() instead of just taking it from the
2029     upper, lower, and digit maps. (Plus the underscore character, of course.)
2030    
2031     5. The above bug also affected the handling of POSIX character classes such as
2032     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2033     permanent tables. Instead, the bit maps for such a class were previously
2034     created as the appropriate unions of the upper, lower, and digit bitmaps.
2035     Now they are created by subtraction from the [[:word:]] class, which has
2036     its own bitmap.
2037    
2038     6. The [[:blank:]] character class matches horizontal, but not vertical space.
2039     It is created by subtracting the vertical space characters (\x09, \x0a,
2040     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2041     subtraction was done in the overall bitmap for a character class, meaning
2042     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2043     be recognized. This bug has been fixed.
2044    
2045     7. Patches from the folks at Google:
2046    
2047     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2048     real life, but is still worth protecting against".
2049    
2050     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2051     regular expressions".
2052    
2053     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2054     have it.
2055    
2056     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2057     "configure" and the latter not, in order to fix a problem somebody had
2058     with compiling the Arg class on HP-UX.
2059    
2060     (e) Improve the error-handling of the C++ wrapper a little bit.
2061    
2062     (f) New tests for checking recursion limiting.
2063    
2064     8. The pcre_memmove() function, which is used only if the environment does not
2065     have a standard memmove() function (and is therefore rarely compiled),
2066     contained two bugs: (a) use of int instead of size_t, and (b) it was not
2067     returning a result (though PCRE never actually uses the result).
2068    
2069     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2070     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2071     returned instead of calling malloc() with an overflowing number that would
2072     most likely cause subsequent chaos.
2073    
2074     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2075    
2076     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2077     with this option is matched, the nmatch and pmatch options of regexec() are
2078     ignored.
2079    
2080     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2081     provided in case anyone wants to the the POSIX interface with UTF-8
2082     strings.
2083    
2084     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2085     C++ linking (needed for some HP-UX environments).
2086    
2087     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2088     (unused parameter) and in the pcre_printint() function (omitted "default"
2089     switch label when the default is to do nothing).
2090    
2091     15. Added some code to make it possible, when PCRE is compiled as a C++
2092     library, to replace subject pointers for pcre_exec() with a smart pointer
2093     class, thus making it possible to process discontinuous strings.
2094    
2095     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2096     much the same function. They were added by different people who were trying
2097     to make PCRE easy to compile on non-Unix systems. It has been suggested
2098     that PCRE_EXPORT be abolished now that there is more automatic apparatus
2099     for compiling on Windows systems. I have therefore replaced it with
2100     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2101     defaults to "extern" for C or "extern C" for C++, which works fine on
2102     Unix-like systems. It is now possible to override the value of PCRE_DATA_
2103     SCOPE with something explicit in config.h. In addition:
2104    
2105     (a) pcreposix.h still had just "extern" instead of either of these macros;
2106     I have replaced it with PCRE_DATA_SCOPE.
2107    
2108     (b) Functions such as _pcre_xclass(), which are internal to the library,
2109     but external in the C sense, all had PCRE_EXPORT in their definitions.
2110     This is apparently wrong for the Windows case, so I have removed it.
2111     (It makes no difference on Unix-like systems.)
2112    
2113     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2114     of recursive calls to match(). This is different to MATCH_LIMIT because
2115     that limits the total number of calls to match(), not all of which increase
2116     the depth of recursion. Limiting the recursion depth limits the amount of
2117     stack (or heap if NO_RECURSE is set) that is used. The default can be set
2118     when PCRE is compiled, and changed at run time. A patch from Google adds
2119     this functionality to the C++ interface.
2120    
2121     18. Changes to the handling of Unicode character properties:
2122    
2123     (a) Updated the table to Unicode 4.1.0.
2124    
2125     (b) Recognize characters that are not in the table as "Cn" (undefined).
2126    
2127     (c) I revised the way the table is implemented to a much improved format
2128     which includes recognition of ranges. It now supports the ranges that
2129     are defined in UnicodeData.txt, and it also amalgamates other
2130     characters into ranges. This has reduced the number of entries in the
2131     table from around 16,000 to around 3,000, thus reducing its size
2132     considerably. I realized I did not need to use a tree structure after
2133     all - a binary chop search is just as efficient. Having reduced the
2134     number of entries, I extended their size from 6 bytes to 8 bytes to
2135     allow for more data.
2136    
2137     (d) Added support for Unicode script names via properties such as \p{Han}.
2138    
2139     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2140     matching that character.
2141    
2142     20. When matching a repeated Unicode property with a minimum greater than zero,
2143     (for example \pL{2,}), PCRE could look past the end of the subject if it
2144     reached it while seeking the minimum number of characters. This could
2145     happen only if some of the characters were more than one byte long, because
2146     there is a check for at least the minimum number of bytes.
2147    
2148     21. Refactored the implementation of \p and \P so as to be more general, to
2149     allow for more different types of property in future. This has changed the
2150     compiled form incompatibly. Anybody with saved compiled patterns that use
2151     \p or \P will have to recompile them.
2152    
2153     22. Added "Any" and "L&" to the supported property types.
2154    
2155     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2156     but give a compile time error if the value is greater than 0xff.
2157    
2158     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2159     accidentally not being installed or uninstalled.
2160    
2161     25. The pcre.h file was built from pcre.h.in, but the only changes that were
2162     made were to insert the current release number. This seemed silly, because
2163     it made things harder for people building PCRE on systems that don't run
2164     "configure". I have turned pcre.h into a distributed file, no longer built
2165     by "configure", with the version identification directly included. There is
2166     no longer a pcre.h.in file.
2167    
2168     However, this change necessitated a change to the pcre-config script as
2169     well. It is built from pcre-config.in, and one of the substitutions was the
2170     release number. I have updated configure.ac so that ./configure now finds
2171     the release number by grepping pcre.h.
2172    
2173     26. Added the ability to run the tests under valgrind.
2174    
2175    
2176 nigel 85 Version 6.4 05-Sep-05
2177     ---------------------
2178    
2179     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2180     "--" to be printed when multiple files were scanned, even when none of the
2181     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2182     consider it to be a bug, and have restored the previous behaviour.
2183    
2184     2. A couple of code tidies to get rid of compiler warnings.
2185    
2186     3. The pcretest program used to cheat by referring to symbols in the library
2187     whose names begin with _pcre_. These are internal symbols that are not
2188     really supposed to be visible externally, and in some environments it is
2189     possible to suppress them. The cheating is now confined to including
2190     certain files from the library's source, which is a bit cleaner.
2191    
2192     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2193     file's purpose clearer.
2194    
2195     5. Reorganized pcre_ucp_findchar().
2196    
2197    
2198 nigel 83 Version 6.3 15-Aug-05
2199     ---------------------
2200    
2201     1. The file libpcre.pc.in did not have general read permission in the tarball.
2202    
2203     2. There were some problems when building without C++ support:
2204    
2205     (a) If C++ support was not built, "make install" and "make test" still
2206     tried to test it.
2207    
2208     (b) There were problems when the value of CXX was explicitly set. Some
2209     changes have been made to try to fix these, and ...
2210    
2211     (c) --disable-cpp can now be used to explicitly disable C++ support.
2212    
2213     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2214     backslash in a target when C++ was disabled. This confuses some
2215     versions of "make", apparently. Using an intermediate variable solves
2216     this. (Same for CPP_LOBJ.)
2217    
2218     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2219     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2220     necessary on certain architectures.
2221    
2222     4. Added a setting of -export-symbols-regex to the link command to remove
2223     those symbols that are exported in the C sense, but actually are local
2224     within the library, and not documented. Their names all begin with
2225     "_pcre_". This is not a perfect job, because (a) we have to except some
2226     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2227     available (and never for static libraries). I have made a note to try to
2228     find a way round (a) in the future.
2229    
2230    
2231 nigel 81 Version 6.2 01-Aug-05
2232     ---------------------
2233    
2234     1. There was no test for integer overflow of quantifier values. A construction
2235     such as {1111111111111111} would give undefined results. What is worse, if
2236     a minimum quantifier for a parenthesized subpattern overflowed and became
2237     negative, the calculation of the memory size went wrong. This could have
2238     led to memory overwriting.
2239    
2240     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2241    
2242     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2243     operating environments where this matters.
2244    
2245     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2246     PCRE options from within the C++ wrapper.
2247    
2248     5. Named capturing subpatterns were not being correctly counted when a pattern
2249     was compiled. This caused two problems: (a) If there were more than 100
2250     such subpatterns, the calculation of the memory needed for the whole
2251     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2252     back references of the form \12, where the number was greater than 9, were
2253     not recognized as back references, even though there were sufficient
2254     previous subpatterns.
2255    
2256     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2257     versions of gcc, e.g. 2.95.4.
2258    
2259    
2260 nigel 79 Version 6.1 21-Jun-05
2261     ---------------------
2262    
2263     1. There was one reference to the variable "posix" in pcretest.c that was not
2264     surrounded by "#if !defined NOPOSIX".
2265    
2266     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2267     the cross-check on the old pcre_info() function, for the benefit of the
2268     cut-down version of PCRE that is currently imported into Exim.
2269    
2270     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2271     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2272     patterns that start (?i) but I don't think that matters. The use of (?i) is
2273     just an example; this all applies to the other options as well.
2274    
2275     4. Since libtool seems to echo the compile commands it is issuing, the output
2276     from "make" can be reduced a bit by putting "@" in front of each libtool
2277     compile command.
2278    
2279     5. Patch from the folks at Google for configure.in to be a bit more thorough
2280     in checking for a suitable C++ installation before trying to compile the
2281     C++ stuff. This should fix a reported problem when a compiler was present,
2282     but no suitable headers.
2283    
2284     6. The man pages all had just "PCRE" as their title. I have changed them to
2285     be the relevant file name. I have also arranged that these names are
2286     retained in the file doc/pcre.txt, which is a concatenation in text format
2287     of all the man pages except the little individual ones for each function.
2288    
2289     7. The NON-UNIX-USE file had not been updated for the different set of source
2290     files that come with release 6. I also added a few comments about the C++
2291     wrapper.
2292    
2293    
2294 nigel 77 Version 6.0 07-Jun-05
2295     ---------------------
2296    
2297     1. Some minor internal re-organization to help with my DFA experiments.
2298    
2299     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2300     didn't matter for the library itself when fully configured, but did matter
2301     when compiling without UCP support, or within Exim, where the ucp files are
2302     not imported.
2303    
2304     3. Refactoring of the library code to split up the various functions into
2305     different source modules. The addition of the new DFA matching code (see
2306     below) to a single monolithic source would have made it really too
2307     unwieldy, quite apart from causing all the code to be include in a
2308     statically linked application, when only some functions are used. This is
2309     relevant even without the DFA addition now that patterns can be compiled in
2310     one application and matched in another.
2311    
2312     The downside of splitting up is that there have to be some external
2313     functions and data tables that are used internally in different modules of
2314     the library but which are not part of the API. These have all had their
2315     names changed to start with "_pcre_" so that they are unlikely to clash
2316     with other external names.
2317    
2318     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2319     a different (DFA) algorithm. Although it is slower than the original
2320     function, it does have some advantages for certain types of matching
2321     problem.
2322    
2323     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2324     including restarting after a partial match.
2325    
2326     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2327     defined when compiling for Windows was sent to me. I have put it into the
2328     code, though I have no means of testing or verifying it.
2329    
2330     7. Added the pcre_refcount() auxiliary function.
2331    
2332     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2333     match before or at the first newline in the subject string. In pcretest,
2334     the /f option on a pattern can be used to set this.
2335    
2336     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2337     would behave wrongly. This has been present in PCRE since release 4.0.
2338    
2339     10. A number of changes to the pcregrep command:
2340    
2341     (a) Refactored how -x works; insert ^(...)$ instead of setting
2342     PCRE_ANCHORED and checking the length, in preparation for adding
2343     something similar for -w.
2344    
2345     (b) Added the -w (match as a word) option.
2346    
2347     (c) Refactored the way lines are read and buffered so as to have more
2348     than one at a time available.
2349    
2350     (d) Implemented a pcregrep test script.
2351    
2352     (e) Added the -M (multiline match) option. This allows patterns to match
2353     over several lines of the subject. The buffering ensures that at least
2354     8K, or the rest of the document (whichever is the shorter) is available
2355     for matching (and similarly the previous 8K for lookbehind assertions).
2356    
2357     (f) Changed the --help output so that it now says
2358    
2359     -w, --word-regex(p)
2360    
2361     instead of two lines, one with "regex" and the other with "regexp"
2362     because that confused at least one person since the short forms are the
2363     same. (This required a bit of code, as the output is generated
2364     automatically from a table. It wasn't just a text change.)
2365    
2366     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2367     option but starts with a hyphen. Could be a pattern or a path name
2368     starting with a hyphen, for instance.
2369    
2370     (h) "-" can be given as a file name to represent stdin.
2371    
2372     (i) When file names are being printed, "(standard input)" is used for
2373     the standard input, for compatibility with GNU grep. Previously
2374     "<stdin>" was used.
2375    
2376     (j) The option --label=xxx can be used to supply a name to be used for
2377     stdin when file names are being printed. There is no short form.
2378    
2379     (k) Re-factored the options decoding logic because we are going to add
2380     two more options that take data. Such options can now be given in four
2381     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2382    
2383     (l) Added the -A, -B, and -C options for requesting that lines of context
2384     around matches be printed.
2385    
2386     (m) Added the -L option to print the names of files that do not contain
2387     any matching lines, that is, the complement of -l.
2388    
2389     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2390     continue to scan other files.
2391    
2392     (o) The -s option was incorrectly implemented. For compatibility with other
2393     greps, it now suppresses the error message for a non-existent or non-
2394     accessible file (but not the return code). There is a new option called
2395     -q that suppresses the output of matching lines, which was what -s was
2396     previously doing.
2397    
2398     (p) Added --include and --exclude options to specify files for inclusion
2399     and exclusion when recursing.
2400    
2401     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2402     Hopefully, it now does.
2403    
2404     12. Missing cast in pcre_study().
2405    
2406     13. Added an "uninstall" target to the makefile.
2407    
2408     14. Replaced "extern" in the function prototypes in Makefile.in with
2409     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2410     world, but is set differently for Windows.
2411    
2412     15. Added a second compiling function called pcre_compile2(). The only
2413     difference is that it has an extra argument, which is a pointer to an
2414     integer error code. When there is a compile-time failure, this is set
2415     non-zero, in addition to the error test pointer being set to point to an
2416     error message. The new argument may be NULL if no error number is required
2417     (but then you may as well call pcre_compile(), which is now just a
2418     wrapper). This facility is provided because some applications need a
2419     numeric error indication, but it has also enabled me to tidy up the way
2420     compile-time errors are handled in the POSIX wrapper.
2421    
2422     16. Added VPATH=.libs to the makefile; this should help when building with one
2423     prefix path and installing with another. (Or so I'm told by someone who
2424     knows more about this stuff than I do.)
2425    
2426     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2427     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2428     match everything, including newlines. This is not POSIX-compatible, but
2429     somebody wanted the feature. From pcretest it can be activated by using
2430     both the P and the s flags.
2431    
2432     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2433    
2434     19. libpcre.pc was being incorrectly installed as executable.
2435    
2436     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2437     it now also looks for '\r' so that it will work unmodified on Windows.
2438    
2439     21. Added Google's contributed C++ wrapper to the distribution.
2440    
2441     22. Added some untidy missing memory free() calls in pcretest, to keep
2442     Electric Fence happy when testing.
2443    
2444    
2445    
2446 nigel 75 Version 5.0 13-Sep-04
2447     ---------------------
2448    
2449     1. Internal change: literal characters are no longer packed up into items
2450     containing multiple characters in a single byte-string. Each character
2451     is now matched using a separate opcode. However, there may be more than one
2452     byte in the character in UTF-8 mode.
2453    
2454     2. The pcre_callout_block structure has two new fields: pattern_position and
2455     next_item_length. These contain the offset in the pattern to the next match
2456     item, and its length, respectively.
2457    
2458     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2459     insertion of callouts before each pattern item. Added the /C option to
2460     pcretest to make use of this.
2461    
2462     4. On the advice of a Windows user, the lines
2463    
2464     #if defined(_WIN32) || defined(WIN32)
2465     _setmode( _fileno( stdout ), 0x8000 );
2466     #endif /* defined(_WIN32) || defined(WIN32) */
2467    
2468     have been added to the source of pcretest. This apparently does useful
2469     magic in relation to line terminators.
2470    
2471     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2472     for the benefit of those environments where the "b" makes a difference.
2473    
2474     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2475     to know about it. I have put a hack into configure.in that adds in code
2476     to set GCC=yes if CC=icc. This seems to end up at a point in the
2477     generated configure script that is early enough to affect the setting of
2478     compiler options, which is what is needed, but I have no means of testing
2479     whether it really works. (The user who reported this had patched the
2480     generated configure script, which of course I cannot do.)
2481    
2482     LATER: After change 22 below (new libtool files), the configure script
2483     seems to know about icc (and also ecc). Therefore, I have commented out
2484     this hack in configure.in.
2485    
2486     7. Added support for pkg-config (2 patches were sent in).
2487    
2488     8. Negated POSIX character classes that used a combination of internal tables
2489     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2490     [[:^ascii]]. Typically, they would match almost any characters. The other
2491     POSIX classes were not broken in this way.
2492    
2493     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2494     to find the match, as PCRE was deluded into thinking that the match had to
2495     start at the start point or following a newline. The same bug applied to
2496     patterns with negative forward assertions or any backward assertions
2497     preceding ".*" at the start, unless the pattern required a fixed first
2498     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2499    
2500     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2501     starting at the last subject character, bytes beyond the end of the subject
2502     string were read.
2503    
2504     11. Renamed the variable "class" as "classbits" to make life easier for C++
2505     users. (Previously there was a macro definition, but it apparently wasn't
2506     enough.)
2507    
2508     12. Added the new field "tables" to the extra data so that tables can be passed
2509     in at exec time, or the internal tables can be re-selected. This allows
2510     a compiled regex to be saved and re-used at a later time by a different
2511     program that might have everything at different addresses.
2512    
2513     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2514     -R library as well as a -L library.
2515    
2516     14. The debugging options of pcretest (-d on the command line or D on a
2517     pattern) showed incorrect output for anything following an extended class
2518     that contained multibyte characters and which was followed by a quantifier.
2519    
2520     15. Added optional support for general category Unicode character properties
2521     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2522     support. It adds about 90K to the size of the library. The meanings of the
2523     inbuilt class escapes such as \d and \s have NOT been changed.
2524    
2525     16. Updated pcredemo.c to include calls to free() to release the memory for the
2526     compiled pattern.
2527    
2528     17. The generated file chartables.c was being created in the source directory
2529     instead of in the building directory. This caused the build to fail if the
2530     source directory was different from the building directory, and was
2531     read-only.
2532    
2533     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2534     file. No doubt somebody will tell me if they don't make sense... Also added
2535     Dan Mooney's comments about building on OpenVMS.
2536    
2537     19. Added support for partial matching via the PCRE_PARTIAL option for
2538     pcre_exec() and the \P data escape in pcretest.
2539    
2540     20. Extended pcretest with 3 new pattern features:
2541    
2542     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2543     write the compiled pattern to the file whose name is "rest-of-line".
2544     This is a straight binary dump of the data, with the saved pointer to
2545     the character tables forced to be NULL. The study data, if any, is
2546     written too. After writing, pcretest reads a new pattern.
2547    
2548     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2549     compiled pattern from the given file. There must not be any
2550     occurrences of "<" in the file name (pretty unlikely); if there are,
2551     pcretest will instead treat the initial "<" as a pattern delimiter.
2552     After reading in the pattern, pcretest goes on to read data lines as
2553     usual.
2554    
2555     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2556     and 16-bit fields in a compiled pattern, to simulate a pattern that
2557     was compiled on a host of opposite endianness.
2558    
2559     21. The pcre-exec() function can now cope with patterns that were compiled on
2560     hosts of opposite endianness, with this restriction:
2561    
2562     As for any compiled expression that is saved and used later, the tables
2563     pointer field cannot be preserved; the extra_data field in the arguments
2564     to pcre_exec() should be used to pass in a tables address if a value
2565     other than the default internal tables were used at compile time.
2566    
2567     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2568     now diagnosed as an error. Previously, most of the time, a negative number
2569     would have been treated as zero, but if in addition "ovector" was passed as
2570     NULL, a crash could occur.
2571    
2572     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2573     new versions from the libtool 1.5 distribution (the last one is a copy of
2574     a file called libtool.m4). This seems to have fixed the need to patch
2575     "configure" to support Darwin 1.3 (which I used to do). However, I still
2576     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2577     workstation).
2578    
2579     24. Changed the PCRE licence to be the more standard "BSD" licence.
2580    
2581    
2582 nigel 73 Version 4.5 01-Dec-03
2583     ---------------------
2584    
2585     1. There has been some re-arrangement of the code for the match() function so
2586     that it can be compiled in a version that does not call itself recursively.
2587     Instead, it keeps those local variables that need separate instances for
2588     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2589     needs to "recurse". Keeping track of where control must go is done by means
2590     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2591     hide most of the details from the main code, and operates only if
2592     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2593     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2594     operating.
2595    
2596     To make it easier for callers to provide specially tailored get/free
2597     functions for this usage, two new functions, pcre_stack_malloc, and
2598     pcre_stack_free, are used. They are always called in strict stacking order,
2599     and the size of block requested is always the same.
2600    
2601     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2602     PCRE has been compiled to use the stack or the heap for recursion. The
2603     -C option of pcretest uses this to show which version is compiled.
2604    
2605     A new data escape \S, is added to pcretest; it causes the amounts of store
2606     obtained and freed by both kinds of malloc/free at match time to be added
2607     to the output.
2608    
2609     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2610     what's available on my current Linux desktop machine.
2611    
2612     3. When matching a UTF-8 string, the test for a valid string at the start has
2613     been extended. If start_offset is not zero, PCRE now checks that it points
2614     to a byte that is the start of a UTF-8 character. If not, it returns
2615     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2616     this is necessary because there may be backward assertions in the pattern.
2617     When matching the same subject several times, it may save resources to use
2618     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2619    
2620     4. The code for checking the validity of UTF-8 strings has been tightened so
2621     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2622     containing "overlong sequences".
2623    
2624     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2625     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2626     should have been "&", but it just so happened that all the cases this let
2627     through by mistake were picked up later in the function.
2628    
2629     6. I had used a variable called "isblank" - this is a C99 function, causing
2630     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2631    
2632     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2633     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2634     so the version is shown; (c) stop "make test" echoing "./RunTest".
2635    
2636     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2637    
2638     9. The prototype for memmove() for systems that don't have it was using
2639     size_t, but the inclusion of the header that defines size_t was later. I've
2640     moved the #includes for the C headers earlier to avoid this.
2641    
2642     10. Added some adjustments to the code to make it easier to compiler on certain
2643     special systems:
2644    
2645     (a) Some "const" qualifiers were missing.
2646     (b) Added the macro EXPORT before all exported functions; by default this
2647     is defined to be empty.
2648     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2649     that it reads its output file name as an argument instead of writing
2650     to the standard output and assuming this can be redirected.
2651    
2652     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2653     class containing characters with values greater than 255, PCRE compilation
2654     went into a loop.
2655    
2656     12. A recursive reference to a subpattern that was within another subpattern
2657     that had a minimum quantifier of zero caused PCRE to crash. For example,
2658     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2659     recursion. If the recursively-called subpattern itself had a zero repeat,
2660     that was OK.
2661    
2662     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2663     buffer into which it was copied (for escape processing) was still set at
2664     1024, so long lines caused crashes.
2665    
2666     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2667     "internal error: code overflow...". This applied to any character class
2668     that was followed by a possessive quantifier.
2669    
2670     15. Modified the Makefile to add libpcre.la as a prerequisite for
2671     libpcreposix.la because I was told this is needed for a parallel build to
2672     work.
2673    
2674     16. If a pattern that contained .* following optional items at the start was
2675     studied, the wrong optimizing data was generated, leading to matching
2676     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2677     matching string must start with a or b or c. The correct conclusion for
2678     this pattern is that a match can start with any character.
2679    
2680    
2681 nigel 71 Version 4.4 13-Aug-03
2682     ---------------------
2683    
2684     1. In UTF-8 mode, a character class containing characters with values between
2685     127 and 255 was not handled correctly if the compiled pattern was studied.
2686     In fixing this, I have also improved the studying algorithm for such
2687     classes (slightly).
2688    
2689     2. Three internal functions had redundant arguments passed to them. Removal
2690     might give a very teeny performance improvement.
2691    
2692     3. Documentation bug: the value of the capture_top field in a callout is *one
2693     more than* the number of the hightest numbered captured substring.
2694    
2695     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2696     in incorrectly linking with a previously installed version. They now link
2697     explicitly with libpcre.la.
2698    
2699     5. configure.in no longer needs to recognize Cygwin specially.
2700    
2701     6. A problem in pcre.in for Windows platforms is fixed.
2702    
2703     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2704     pcretest, it used to include the size of the study block as part of its
2705     output. Unfortunately, the structure contains a field that has a different
2706     size on different hardware architectures. This meant that the tests that
2707     showed this size failed. As the block is currently always of a fixed size,
2708     this information isn't actually particularly useful in pcretest output, so
2709     I have just removed it.
2710    
2711     8. Three pre-processor statements accidentally did not start in column 1.
2712     Sadly, there are *still* compilers around that complain, even though
2713     standard C has not required this for well over a decade. Sigh.
2714    
2715     9. In pcretest, the code for checking callouts passed small integers in the
2716     callout_data field, which is a void * field. However, some picky compilers
2717     complained about the casts involved for this on 64-bit systems. Now
2718     pcretest passes the address of the small integer instead, which should get
2719     rid of the warnings.
2720    
2721     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2722     both compile and run time, and gives an error if an invalid UTF-8 sequence
2723     is found. There is a option for disabling this check in cases where the
2724     string is known to be correct and/or the maximum performance is wanted.
2725    
2726     11. In response to a bug report, I changed one line in Makefile.in from
2727    
2728     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2729     to
2730     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2731    
2732     to look similar to other lines, but I have no way of telling whether this
2733     is the right thing to do, as I do not use Windows. No doubt I'll get told
2734     if it's wrong...
2735    
2736    
2737 nigel 69 Version 4.3 21-May-03
2738     ---------------------
2739    
2740     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2741     Makefile.
2742    
2743     2. Some refactoring to improve the quality of the code:
2744    
2745     (i) The utf8_table... variables are now declared "const".
2746    
2747     (ii) The code for \cx, which used the "case flipping" table to upper case
2748     lower case letters, now just substracts 32. This is ASCII-specific,
2749     but the whole concept of \cx is ASCII-specific, so it seems
2750     reasonable.
2751    
2752     (iii) PCRE was using its character types table to recognize decimal and
2753     hexadecimal digits in the pattern. This is silly, because it handles
2754     only 0-9, a-f, and A-F, but the character types table is locale-
2755     specific, which means strange things might happen. A private
2756     table is now used for this - though it costs 256 bytes, a table is
2757     much faster than multiple explicit tests. Of course, the standard
2758     character types table is still used for matching digits in subject
2759     strings against \d.
2760    
2761     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2762     ending in _t are). So I've renamed it as ESC_tee.
2763    
2764     3. The first argument for regexec() in the POSIX wrapper should have been
2765     defined as "const".
2766    
2767     4. Changed pcretest to use malloc() for its buffers so that they can be
2768     Electric Fenced for debugging.
2769    
2770     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2771     to read one or more bytes before the start of the subject string. Often this
2772     had no effect on PCRE's behaviour, but in some circumstances it could
2773     provoke a segmentation fault.
2774    
2775     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2776     to try to read one or more bytes before the start of the subject string.
2777    
2778     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2779     UTF-8 support could misbehave in various ways if the subject string
2780     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2781     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2782     back over UTF-8 characters.)
2783    
2784    
2785 nigel 67 Version 4.2 14-Apr-03
2786     ---------------------
2787    
2788     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2789    
2790     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2791     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2792     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2793     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2794     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2795     and BUILD_EXEEXT
2796     Note: automatic setting of the BUILD variables is not yet working
2797     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2798     compile-time but not at link-time
2799     [LINK]: use for linking executables only
2800     make different versions for Windows and non-Windows
2801     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2802     libraries
2803     [LINK_FOR_BUILD]: new variable
2804     [OBJEXT]: use throughout
2805     [EXEEXT]: use throughout
2806     <winshared>: new target
2807     <wininstall>: new target
2808     <dftables.o>: use native compiler
2809     <dftables>: use native linker
2810     <install>: handle Windows platform correctly
2811     <clean>: ditto
2812     <check>: ditto
2813     copy DLL to top builddir before testing
2814    
2815     As part of these changes, -no-undefined was removed again. This was reported
2816     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2817     in any case.
2818    
2819     3. Some tidies to get rid of compiler warnings:
2820    
2821     . In the match_data structure, match_limit was an unsigned long int, whereas
2822     match_call_count was an int. I've made them both unsigned long ints.
2823    
2824     . In pcretest the fact that a const uschar * doesn't automatically cast to
2825     a void * provoked a warning.
2826    
2827     . Turning on some more compiler warnings threw up some "shadow" variables
2828     and a few more missing casts.
2829    
2830     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2831     option, a class that contained a single character with a value between 128
2832     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2833    
2834     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2835     option, a class that contained several characters, but with at least one
2836     whose value was between 128 and 255 caused PCRE to crash.
2837    
2838    
2839 nigel 65 Version 4.1 12-Mar-03
2840     ---------------------
2841 nigel 63
2842 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2843     needed, and a string in dftables.c that was longer than standard compilers are
2844     required to support.
2845    
2846     2. Compiling with Sun's compiler found a few more places where the code could
2847     be tidied up in order to avoid warnings.
2848    
2849     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2850     first of these names is deprecated in the latest Autoconf in favour of the name
2851     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2852     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2853     analogy I have changed it to CFLAGS_FOR_BUILD.
2854    
2855     4. Added -no-undefined to the linking command in the Makefile, because this is
2856     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2857     linking step for the pcreposix library.
2858    
2859     5. PCRE was failing to diagnose the case of two named groups with the same
2860     name.
2861    
2862     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2863     literal character that is needed in the subject for a match, and scans along to
2864     ensure that it is present before embarking on the full matching process. This
2865     saves time in cases of nested unlimited repeats that are never going to match.
2866     Problem: the scan can take a lot of time if the subject is very long (e.g.
2867     megabytes), thus penalizing straightforward matches. It is now done only if the
2868     amount of subject to be scanned is less than 1000 bytes.
2869    
2870     7. A lesser problem with the same optimization is that it was recording the
2871     first character of an anchored pattern as "needed", thus provoking a search
2872     right along the subject, even when the first match of the pattern was going to
2873     fail. The "needed" character is now not set for anchored patterns, unless it
2874     follows something in the pattern that is of non-fixed length. Thus, it still
2875     fulfils its original purpose of finding quick non-matches in cases of nested
2876     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2877    
2878    
2879     Version 4.0 17-Feb-03
2880     ---------------------
2881    
2882 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2883     extended to the end of string, PCRE compiled incorrect data. This could lead to
2884     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2885    
2886     2. Moved to autoconf 2.53 and libtool 1.4.2.
2887    
2888     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2889     the special perltest8 script is no longer needed - all the tests can be run
2890     from a single perltest script.
2891    
2892     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2893     by \s. It has now been removed in PCRE. This means it isn't recognized as
2894     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2895     class [:space:] *does* include VT, thereby creating a mess.
2896    
2897     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2898     space and tab.
2899    
2900     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2901     its new features into the main test script, reducing the number of scripts.
2902    
2903     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2904     were backward compatible, and made the (?i) apply to the whole pattern, as if
2905     /i were given. Now it behaves more logically, and applies the option setting
2906     only to what follows. PCRE has been changed to follow suit. However, if it
2907     finds options settings right at the start of the pattern, it extracts them into
2908     the global options, as before. Thus, they show up in the info data.
2909    
2910     8. Added support for the \Q...\E escape sequence. Characters in between are
2911     treated as literals. This is slightly different from Perl in that $ and @ are
2912     also handled as literals inside the quotes. In Perl, they will cause variable
2913     interpolation. Note the following examples:
2914    
2915     Pattern PCRE matches Perl matches
2916    
2917     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2918     \Qabc\$xyz\E abc\$xyz abc\$xyz
2919     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2920    
2921     For compatibility with Perl, \Q...\E sequences are recognized inside character
2922     classes as well as outside them.
2923    
2924     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2925     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2926     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2927     signed/unsigned warnings.
2928    
2929     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2930     option for pcretest, so I've replaced it by a simple function that does just
2931     that job.
2932    
2933     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2934     "pcregrep -".
2935    
2936     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2937     Java package. This provides some syntactic sugar for simple cases of what my
2938     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2939     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2940     item, you can use this simplified notation. Note that only makes sense with
2941     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2942     greediness, whatever the setting of the PCRE_UNGREEDY option.
2943    
2944     13. A change of greediness default within a pattern was not taking effect at
2945     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2946     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2947     was abstracted outside.
2948    
2949     14. PCRE now supports the \G assertion. It is true when the current matching
2950     position is at the start point of the match. This differs from \A when the
2951     starting offset is non-zero. Used with the /g option of pcretest (or similar
2952     code), it works in the same way as it does for Perl's /g option. If all
2953     alternatives of a regex begin with \G, the expression is anchored to the start
2954     match position, and the "anchored" flag is set in the compiled expression.
2955    
2956     15. Some bugs concerning the handling of certain option changes within patterns
2957     have been fixed. These applied to options other than (?ims). For example,
2958     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2959     been the other way round. Some of this was related to change 7 above.
2960    
2961     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2962     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2963     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2964     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2965    
2966     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2967     mode. Unlike ".", it always matches newline, whatever the setting of
2968     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2969     assertions. Perl allows it, but it doesn't (in general) work because it can't
2970     calculate the length of the lookbehind. At least, that's the case for Perl
2971     5.8.0 - I've been told they are going to document that it doesn't work in
2972     future.
2973    
2974     18. Added an error diagnosis for escapes that PCRE does not support: these are
2975     \L, \l, \N, \P, \p, \U, \u, and \X.
2976    
2977     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2978     reading past the end of the pattern in cases such as /[abcd/.
2979    
2980     20. PCRE was getting more memory than necessary for patterns with classes that
2981     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2982    
2983     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2984     compiling PCRE for use with Virtual Pascal.
2985    
2986     22. Small fix to the Makefile to make it work properly if the build is done
2987     outside the source tree.
2988    
2989     23. Added a new extension: a condition to go with recursion. If a conditional
2990     subpattern starts with (?(R) the "true" branch is used if recursion has
2991     happened, whereas the "false" branch is used only at the top level.
2992    
2993     24. When there was a very long string of literal characters (over 255 bytes
2994     without UTF support, over 250 bytes with UTF support), the computation of how
2995     much memory was required could be incorrect, leading to segfaults or other
2996     strange effects.
2997    
2998     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2999     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3000     there was a subsequent back reference to those brackets. This meant that, for
3001     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3002     possible to check for precisely this case. All we can do is abandon the
3003     optimization if .* occurs inside capturing brackets when there are any back
3004     references whatsoever. (See below for a better fix that came later.)
3005    
3006     26. The handling of the optimization for finding the first character of a
3007     non-anchored pattern, and for finding a character that is required later in the
3008     match were failing in some cases. This didn't break the matching; it just
3009     failed to optimize when it could. The way this is done has been re-implemented.
3010    
3011     27. Fixed typo in error message for invalid (?R item (it said "(?p").
3012    
3013     28. Added a new feature that provides some of the functionality that Perl
3014     provides with (?{...}). The facility is termed a "callout". The way it is done
3015     in PCRE is for the caller to provide an optional function, by setting
3016     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3017     global variable. By default it is unset, which disables all calling out. To get
3018     the function called, the regex must include (?C) at appropriate points. This
3019     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3020     This provides a means of identifying different callout points. When PCRE
3021     reaches such a point in the regex, if pcre_callout has been set, the external
3022     function is called. It is provided with data in a structure called
3023     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3024     matching continues; if it returns a non-zero value, the match at the current
3025     point fails. However, backtracking will occur if possible. [This was changed
3026     later and other features added - see item 49 below.]
3027    
3028     29. pcretest is upgraded to test the callout functionality. It provides a
3029     callout function that displays information. By default, it shows the start of
3030     the match and the current position in the text. There are some new data escapes
3031     to vary what happens:
3032    
3033     \C+ in addition, show current contents of captured substrings
3034     \C- do not supply a callout function
3035     \C!n return 1 when callout number n is reached
3036     \C!n!m return 1 when callout number n is reached for the mth time
3037    
3038     30. If pcregrep was called with the -l option and just a single file name, it
3039     output "<stdin>" if a match was found, instead of the file name.
3040    
3041     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3042     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3043     pcre_exec(). This saves a malloc/free per call. The default value of
3044     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3045     when configuring.
3046    
3047     32. The default maximum size of a compiled pattern is 64K. There have been a
3048     few cases of people hitting this limit. The code now uses macros to handle the
3049     storing of links as offsets within the compiled pattern. It defaults to 2-byte
3050     links, but this can be changed to 3 or 4 bytes by --with-link-size when
3051     configuring. Tests 2 and 5 work only with 2-byte links because they output
3052     debugging information about compiled patterns.
3053    
3054     33. Internal code re-arrangements:
3055    
3056     (a) Moved the debugging function for printing out a compiled regex into
3057     its own source file (printint.c) and used #include to pull it into
3058     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3059     separate copies.
3060    
3061     (b) Defined the list of op-code names for debugging as a macro in
3062     internal.h so that it is next to the definition of the opcodes.
3063    
3064     (c) Defined a table of op-code lengths for simpler skipping along compiled
3065     code. This is again a macro in internal.h so that it is next to the
3066     definition of the opcodes.
3067    
3068     34. Added support for recursive calls to individual subpatterns, along the
3069     lines of Robin Houston's patch (but implemented somewhat differently).
3070    
3071     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3072     allow it to read and process whole directories in Win32. This code was
3073     contributed by Lionel Fourquaux; it has not been tested by me.
3074    
3075     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3076     used to name a group. Names consist of alphanumerics and underscores, and must
3077     be unique. Back references use the syntax (?P=name) and recursive calls use
3078     (?P>name) which is a PCRE extension to the Python extension. Groups still have
3079     numbers. The function pcre_fullinfo() can be used after compilation to extract
3080     a name/number map. There are three relevant calls:
3081    
3082     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3083     PCRE_INFO_NAMECOUNT yields the number of entries
3084     PCRE_INFO_NAMETABLE yields a pointer to the map.
3085    
3086     The map is a vector of fixed-size entries. The size of each entry depends on
3087     the length of the longest name used. The first two bytes of each entry are the
3088     group number, most significant byte first. There follows the corresponding
3089     name, zero terminated. The names are in alphabetical order.
3090    
3091     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3092     case instead of 255. Making it the same both with and without UTF-8 support
3093     means that the same test output works with both.
3094    
3095     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3096     calling malloc() with a zero argument.
3097    
3098     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3099     optimization. I've improved things by keeping a bitmap of backreferences with
3100     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3101     fact referenced, the optimization can be applied. It is unlikely that a
3102     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3103     the match to follow \n) will appear inside brackets with a number greater than
3104     31, but if it does, any back reference > 31 suppresses the optimization.
3105    
3106     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3107     of disabling numbered capturing parentheses. Any opening parenthesis that is
3108     not followed by ? behaves as if it were followed by ?: but named parentheses
3109     can still be used for capturing (and they will acquire numbers in the usual
3110     way).
3111    
3112     41. Redesigned the return codes from the match() function into yes/no/error so
3113     that errors can be passed back from deep inside the nested calls. A malloc
3114     failure while inside a recursive subpattern call now causes the
3115     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3116    
3117     42. It is now possible to set a limit on the number of times the match()
3118     function is called in a call to pcre_exec(). This facility makes it possible to
3119     limit the amount of recursion and backtracking, though not in a directly
3120     obvious way, because the match() function is used in a number of different
3121     circumstances. The count starts from zero for each position in the subject
3122     string (for non-anchored patterns). The default limit is, for compatibility, a
3123     large number, namely 10 000 000. You can change this in two ways:
3124    
3125     (a) When configuring PCRE before making, you can use --with-match-limit=n
3126     to set a default value for the compiled library.
3127    
3128     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3129     a different value is set. See 45 below.
3130    
3131     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3132    
3133     43. Added a new function pcre_config(int, void *) to enable run-time extraction
3134     of things that can be changed at compile time. The first argument specifies
3135     what is wanted and the second points to where the information is to be placed.
3136     The current list of available information is:
3137    
3138     PCRE_CONFIG_UTF8
3139    
3140     The output is an integer that is set to one if UTF-8 support is available;
3141     otherwise it is set to zero.
3142    
3143     PCRE_CONFIG_NEWLINE
3144    
3145     The output is an integer that it set to the value of the code that is used for
3146     newline. It is either LF (10) or CR (13).
3147    
3148     PCRE_CONFIG_LINK_SIZE
3149    
3150     The output is an integer that contains the number of bytes used for internal
3151     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3152    
3153     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3154    
3155     The output is an integer that contains the threshold above which the POSIX
3156     interface uses malloc() for output vectors. See item 31 above.
3157    
3158     PCRE_CONFIG_MATCH_LIMIT
3159    
3160     The output is an unsigned integer that contains the default limit of the number
3161     of match() calls in a pcre_exec() execution. See 42 above.
3162    
3163     44. pcretest has been upgraded by the addition of the -C option. This causes it
3164     to extract all the available output from the new pcre_config() function, and to
3165     output it. The program then exits immediately.
3166    
3167     45. A need has arisen to pass over additional data with calls to pcre_exec() in
3168     order to support additional features. One way would have been to define
3169     pcre_exec2() (for example) with extra arguments, but this would not have been
3170     extensible, and would also have required all calls to the original function to
3171     be mapped to the new one. Instead, I have chosen to extend the mechanism that
3172     is used for passing in "extra" data from pcre_study().
3173    
3174     The pcre_extra structure is now exposed and defined in pcre.h. It currently
3175     contains the following fields:
3176    
3177     flags a bitmap indicating which of the following fields are set
3178     study_data opaque data from pcre_study()
3179     match_limit a way of specifying a limit on match() calls for a specific
3180     call to pcre_exec()
3181     callout_data data for callouts (see 49 below)
3182    
3183     The flag bits are also defined in pcre.h, and are
3184    
3185     PCRE_EXTRA_STUDY_DATA
3186     PCRE_EXTRA_MATCH_LIMIT
3187     PCRE_EXTRA_CALLOUT_DATA
3188    
3189     The pcre_study() function now returns one of these new pcre_extra blocks, with
3190     the actual study data pointed to by the study_data field, and the
3191     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3192     before. That is, this change is entirely upwards-compatible and requires no
3193     change to existing code.
3194    
3195     If you want to pass in additional data to pcre_exec(), you can either place it
3196     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3197     block.
3198    
3199     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3200     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3201     times with different match limits, until it finds the minimum value needed for
3202     pcre_exec() to complete. The value is then output. This can be instructive; for
3203     most simple matches the number is quite small, but for pathological cases it
3204     gets very large very quickly.
3205    
3206     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3207     returns the size of the data block pointed to by the study_data field in a
3208     pcre_extra block, that is, the value that was passed as the argument to
3209     pcre_malloc() when PCRE was getting memory in which to place the information
3210     created by pcre_study(). The fourth argument should point to a size_t variable.
3211     pcretest has been extended so that this information is shown after a successful
3212     pcre_study() call when information about the compiled regex is being displayed.
3213    
3214     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3215     because what follows is always an absolute path. (Later: it turns out that this
3216     is more than cosmetic for MinGW, because it doesn't like empty path
3217     components.)
3218    
3219     49. Some changes have been made to the callout feature (see 28 above):
3220    
3221     (i) A callout function now has three choices for what it returns:
3222    
3223     0 => success, carry on matching
3224     > 0 => failure at this point, but backtrack if possible
3225     < 0 => serious error, return this value from pcre_exec()
3226    
3227     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3228     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3229     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3230     use by callout functions. It will never be used by PCRE itself.
3231    
3232     (ii) The pcre_extra structure (see 45 above) has a void * field called
3233     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3234     pcre_callout_block structure has a field of the same name. The contents of
3235     the field passed in the pcre_extra structure are passed to the callout
3236     function in the corresponding field in the callout block. This makes it
3237     easier to use the same callout-containing regex from multiple threads. For
3238     testing, the pcretest program has a new data escape
3239    
3240     \C*n pass the number n (may be negative) as callout_data
3241    
3242     If the callout function in pcretest receives a non-zero value as
3243     callout_data, it returns that value.
3244    
3245     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3246     there were some redundant $(CFLAGS) in commands that are now specified as
3247     $(LINK), which already includes $(CFLAGS).
3248    
3249     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3250     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3251     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3252     one-byte characters throughout. Note that case-insensitive matching applies
3253     only to characters whose values are less than 256. PCRE doesn't support the
3254     notion of cases for higher-valued characters.
3255    
3256     (i) A character class whose characters are all within 0-255 is handled as
3257     a bit map, and the map is inverted for negative classes. Previously, a
3258     character > 255 always failed to match such a class; however it should
3259     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3260    
3261     (ii) A negated character class with a single character < 255 is coded as
3262     "not this character" (OP_NOT). This wasn't working properly when the test
3263     character was multibyte, either singly or repeated.
3264    
3265     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3266     mode, for example: \x{100}{2,3}.
3267    
3268     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3269     singly or repeated) now correctly test multibyte characters. However,
3270     PCRE doesn't recognize any characters with values greater than 255 as
3271     digits, spaces, or word characters. Such characters always match \D, \S,
3272     and \W, and never match \d, \s, or \w.
3273    
3274     (v) Classes may now contain characters and character ranges with values
3275     greater than 255. For example: [ab\x{100}-\x{400}].
3276    
3277     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3278     PCRE in UTF-8 mode.
3279    
3280     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3281     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3282     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3283     value.)
3284    
3285     53. The single man page has become too large. I have therefore split it up into
3286     a number of separate man pages. These also give rise to individual HTML pages;
3287     these are now put in a separate directory, and there is an index.html page that
3288     lists them all. Some hyperlinking between the pages has been installed.
3289    
3290     54. Added convenience functions for handling named capturing parentheses.
3291    
3292     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3293     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3294     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3295     are faulted.
3296    
3297     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3298     calling configure. These values are used when compiling the dftables.c program
3299     which is run to generate the source of the default character tables. They
3300     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3301     you will need to set these values.
3302    
3303     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3304    
3305    
3306     Version 3.9 02-Jan-02
3307 nigel 61 ---------------------
3308    
3309     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3310    
3311     2. If --disable-static was given, the building process failed when trying to
3312     build pcretest and pcregrep. (For some reason it was using libtool to compile
3313     them, which is not right, as they aren't part of the library.)
3314    
3315    
3316 nigel 59 Version 3.8 18-Dec-01
3317     ---------------------
3318    
3319     1. The experimental UTF-8 code was completely screwed up. It was packing the
3320     bytes in the wrong order. How dumb can you get?
3321    
3322    
3323 nigel 57 Version 3.7 29-Oct-01
3324     ---------------------
3325    
3326     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3327     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3328     this didn't happen under Solaris 8, where I normally test things.
3329    
3330 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3331     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3332     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3333     this fix an hour or so after the initial 3.7 release.)
3334 nigel 57
3335 nigel 59
3336 nigel 55 Version 3.6 23-Oct-01
3337     ---------------------
3338    
3339     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3340     offsets passed as NULL with zero offset count.
3341    
3342     2. The config.guess and config.sub files had not been updated when I moved to
3343     the latest autoconf.
3344    
3345    
3346 nigel 53 Version 3.5 15-Aug-01
3347     ---------------------
3348 nigel 5
3349 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3350     had been forgotten.
3351    
3352     2. By using declared but undefined structures, we can avoid using "void"
3353     definitions in pcre.h while keeping the internal definitions of the structures
3354     private.
3355    
3356     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3357     user point of view, this means that both static and shared libraries are built
3358     by default, but this can be individually controlled. More of the work of
3359     handling this static/shared cases is now inside libtool instead of PCRE's make
3360     file.
3361    
3362     4. The pcretest utility is now installed along with pcregrep because it is
3363     useful for users (to test regexs) and by doing this, it automatically gets
3364     relinked by libtool. The documentation has been turned into a man page, so
3365     there are now .1, .txt, and .html versions in /doc.
3366    
3367     5. Upgrades to pcregrep:
3368     (i) Added long-form option names like gnu grep.
3369     (ii) Added --help to list all options with an explanatory phrase.
3370     (iii) Added -r, --recursive to recurse into sub-directories.
3371     (iv) Added -f, --file to read patterns from a file.
3372    
3373     6. pcre_exec() was referring to its "code" argument before testing that
3374     argument for NULL (and giving an error if it was NULL).
3375    
3376     7. Upgraded Makefile.in to allow for compiling in a different directory from
3377     the source directory.
3378    
3379     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3380     options bits, the pointer it was passed was to an int instead of to an unsigned
3381     long int. This mattered only on 64-bit systems.
3382    
3383     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3384     generated) instead of pcre.in, which it its source. Also made the same change
3385     in several of the .c files.
3386    
3387     10. A new release of gcc defines printf() as a macro, which broke pcretest
3388     because it had an ifdef in the middle of a string argument for printf(). Fixed
3389     by using separate calls to printf().
3390    
3391     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3392     script, to force use of CR or LF instead of \n in the source. On non-Unix
3393     systems, the value can be set in config.h.
3394    
3395     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3396     absolute limit. Changed the text of the error message to make this clear, and
3397     likewise updated the man page.
3398    
3399     13. The limit of 99 on the number of capturing subpatterns has been removed.
3400     The new limit is 65535, which I hope will not be a "real" limit.
3401    
3402    
3403 nigel 51 Version 3.4 22-Aug-00
3404     ---------------------
3405    
3406     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3407    
3408     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3409    
3410    
3411 nigel 49 Version 3.3 01-Aug-00
3412     ---------------------
3413    
3414     1. If an octal character was given, but the value was greater than \377, it
3415     was not getting masked to the least significant bits, as documented. This could
3416     lead to crashes in some systems.
3417    
3418     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3419     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3420    
3421     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3422     These just pass their arguments on to (pcre_free)(), but they are provided
3423     because some uses of PCRE bind it to non-C systems that can call its functions,
3424     but cannot call free() or pcre_free() directly.
3425    
3426     4. Add "make test" as a synonym for "make check". Corrected some comments in
3427     the Makefile.
3428    
3429     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3430     Makefile.
3431    
3432     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3433     command called pgrep for grepping around the active processes.
3434    
3435     7. Added the beginnings of support for UTF-8 character strings.
3436    
3437     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3438     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3439     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3440     out for the ar command.)
3441    
3442    
3443 nigel 47 Version 3.2 12-May-00
3444     ---------------------
3445    
3446     This is purely a bug fixing release.
3447    
3448     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3449     of ZA. This was just one example of several cases that could provoke this bug,
3450     which was introduced by change 9 of version 2.00. The code for breaking
3451     infinite loops after an iteration that matches an empty string was't working
3452     correctly.
3453    
3454     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3455     when matched against abbab (for example). After matching an empty string, it
3456     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3457     caused it to match further down the string than it should.
3458    
3459     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3460     was there because it doesn't seem to be needed, and it causes trouble on some
3461     systems, as it is not a Standard C header. It has been removed.
3462    
3463     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3464     were reported on the Macintosh. The changes were from
3465    
3466     while ((c = *(++ptr)) != 0 && c != '\n');
3467     to
3468     while ((c = *(++ptr)) != 0 && c != '\n') ;
3469    
3470     Totally extraordinary, but if that's what it takes...
3471    
3472     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3473     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3474     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3475     assumes the way PCRE uses memmove() (always moving upwards).
3476    
3477     6. PCRE is being used in one environment where strchr() is not available. There
3478     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3479     faster code anyway.
3480    
3481    
3482 nigel 45 Version 3.1 09-Feb-00
3483     ---------------------
3484    
3485     The only change in this release is the fixing of some bugs in Makefile.in for
3486     the "install" target:
3487    
3488     (1) It was failing to install pcreposix.h.
3489    
3490     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3491    
3492    
3493 nigel 43 Version 3.0 01-Feb-00
3494     ---------------------
3495 nigel 41
3496     1. Add support for the /+ modifier to perltest (to output $` like it does in
3497     pcretest).
3498    
3499     2. Add support for the /g modifier to perltest.
3500    
3501     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3502     matches null strings.
3503    
3504     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3505     pattern. Perl treats empty patterns specially - it reuses the most recent
3506     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3507     effect.
3508    
3509     5. The POSIX interface was broken in that it was just handing over the POSIX
3510     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3511     required a bigger vector, with some working space on the end. This means that
3512     the POSIX wrapper now has to get and free some memory, and copy the results.
3513    
3514 nigel 43 6. Added some simple autoconf support, placing the test data and the
3515     documentation in separate directories, re-organizing some of the
3516     information files, and making it build pcre-config (a GNU standard). Also added
3517     libtool support for building PCRE as a shared library, which is now the
3518     default.
3519 nigel 41
3520 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3521     09 are not valid octal constants. Single digits will be used for minor values
3522     less than 10.
3523    
3524     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3525     existing programs that set these in the POSIX interface can use PCRE without
3526     modification.
3527    
3528     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3529     return all that pcre_info() returns, plus additional data. The pcre_info()
3530     function is retained for compatibility, but is considered to be obsolete.
3531    
3532     10. Added experimental recursion feature (?R) to handle one common case that
3533     Perl 5.6 will be able to do with (?p{...}).
3534    
3535     11. Added support for POSIX character classes like [:alpha:], which Perl is
3536     adopting.
3537    
3538    
3539 nigel 39 Version 2.08 31-Aug-99
3540     ----------------------
3541    
3542     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3543     trying to match at the startoffset position, but instead was moving forward to
3544     the next newline as if a previous match had failed.
3545    
3546     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3547     and could get into a loop if a null string was matched other than at the start
3548     of the subject.
3549    
3550     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3551     be distinguished at compile time, and for completeness also added PCRE_DATE.
3552    
3553     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3554     in GnuWin32 environments.
3555    
3556    
3557 nigel 37 Version 2.07 29-Jul-99
3558     ----------------------
3559    
3560     1. The documentation is now supplied in plain text form and HTML as well as in
3561     the form of man page sources.
3562    
3563     2. C++ compilers don't like assigning (void *) values to other pointer types.
3564     In particular this affects malloc(). Although there is no problem in Standard
3565     C, I've put in casts to keep C++ compilers happy.
3566    
3567     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3568     should be (const char *).
3569    
3570     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3571     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3572     However, I haven't made this a standard facility. The documentation doesn't
3573     mention it, and the Makefile doesn't support it.
3574    
3575     5. The Makefile now contains an "install" target, with editable destinations at
3576     the top of the file. The pcretest program is not installed.
3577    
3578     6. pgrep -V now gives the PCRE version number and date.
3579    
3580     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3581     causing the entire string to be ignored, instead of just the last character.
3582    
3583     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3584     non-matching string, it can take a very, very long time, even for strings of
3585     quite modest length, because of the nested recursion. PCRE now does better in
3586     some of these cases. It does this by remembering the last required literal
3587     character in the pattern, and pre-searching the subject to ensure it is present
3588     before running the real match. In other words, it applies a heuristic to detect
3589     some types of certain failure quickly, and in the above example, if presented
3590     with a string that has no trailing " it gives "no match" very quickly.
3591    
3592     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3593     other alternatives are tried instead.
3594    
3595    
3596 nigel 35 Version 2.06 09-Jun-99
3597     ----------------------
3598    
3599     1. Change pcretest's output for amount of store used to show just the code
3600     space, because the remainder (the data block) varies in size between 32-bit and
3601     64-bit systems.
3602    
3603     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3604     start matching at. This allows lookbehinds to work when searching for multiple
3605     occurrences in a string.
3606    
3607     3. Added additional options to pcretest for testing multiple occurrences:
3608    
3609     /+ outputs the rest of the string that follows a match
3610     /g loops for multiple occurrences, using the new startoffset argument
3611     /G loops for multiple occurrences by passing an incremented pointer
3612    
3613     4. PCRE wasn't doing the "first character" optimization for patterns starting
3614     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3615     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3616     the letter 'x'. On long subject strings, this gives a significant speed-up.
3617    
3618    
3619 nigel 33 Version 2.05 21-Apr-99
3620     ----------------------
3621    
3622     1. Changed the type of magic_number from int to long int so that it works
3623     properly on 16-bit systems.
3624    
3625     2. Fixed a bug which caused patterns starting with .* not to work correctly
3626     when the subject string contained newline characters. PCRE was assuming
3627     anchoring for such patterns in all cases, which is not correct because .* will
3628     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3629     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3630     must be retried after every newline in the subject.
3631    
3632    
3633 nigel 31 Version 2.04 18-Feb-99
3634     ----------------------
3635    
3636     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3637     computation of the store needed to hold the pattern was incorrect (too large).
3638     If such patterns were nested a few deep, this could multiply and become a real
3639     problem.
3640    
3641     2. Added /M option to pcretest to show the memory requirement of a specific
3642     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3643    
3644     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3645     compiled in such a way that the backtracking after subsequent failure was
3646     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3647     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3648    
3649    
3650 nigel 29 Version 2.03 02-Feb-99
3651     ----------------------
3652    
3653     1. Fixed typo and small mistake in man page.
3654    
3655 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3656     LICENCE file containing the conditions.
3657 nigel 29
3658     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3659     Perl, that is the internal \ allows the delimiter to be included in the
3660     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3661     the final delimiter, add \ to the end of the pattern (to test the error).
3662    
3663     4. Added the convenience functions for extracting substrings after a successful
3664     match. Updated pcretest to make it able to test these functions.
3665    
3666    
3667 nigel 27 Version 2.02 14-Jan-99
3668     ----------------------
3669    
3670     1. Initialized the working variables associated with each extraction so that
3671     their saving and restoring doesn't refer to uninitialized store.
3672    
3673     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3674     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3675     fix the problem.
3676    
3677     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3678     calls, and wasn't printing the correct value for compiling calls. Increased the
3679     default value of LOOPREPEAT, and the number of significant figures in the
3680     times.
3681    
3682     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3683    
3684     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3685     a building problem on Windows NT with a FAT file system.
3686    
3687    
3688 nigel 25 Version 2.01 21-Oct-98
3689     ----------------------
3690    
3691     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3692     to character tables built by pcre_maketables() in the current locale. If NULL
3693     is passed, the default tables are used.
3694    
3695    
3696 nigel 23 Version 2.00 24-Sep-98
3697 nigel 21 ----------------------
3698    
3699 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3700     it any more.
3701    
3702     2. Allow quantification of (?>) groups, and make it work correctly.
3703    
3704     3. The first character computation wasn't working for (?>) groups.
3705    
3706     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3707     end of the subject) and add 5.005's \z, which really does match only at the
3708     very end of the subject.
3709    
3710     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3711    
3712     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3713     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3714     localized options. All options to pcre_study() were also removed.
3715    
3716     7. Add other new features from 5.005:
3717    
3718     $(?<= positive lookbehind
3719     $(?<! negative lookbehind
3720     (?imsx-imsx) added the unsetting capability
3721     such a setting is global if at outer level; local otherwise
3722     (?imsx-imsx:) non-capturing groups with option setting
3723     (?(cond)re|re) conditional pattern matching
3724    
3725     A backreference to itself in a repeated group matches the previous
3726     captured string.
3727    
3728     8. General tidying up of studying (both automatic and via "study")
3729     consequential on the addition of new assertions.
3730    
3731     9. As in 5.005, unlimited repeated groups that could match an empty substring
3732     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3733     runtime if any iteration does actually match an empty substring.
3734    
3735     10. Include the RunTest script in the distribution.
3736    
3737     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3738     discrepancies, some of which were old and were also with respect to 5.004. They
3739     have now been fixed.
3740    
3741    
3742     Version 1.09 28-Apr-98
3743     ----------------------
3744    
3745 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3746     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3747     program crashes, or just wrong answers. This did not apply to negated classes
3748     containing more than one character, or to minima other than one.
3749    
3750    
3751 nigel 19 Version 1.08 27-Mar-98
3752     ----------------------
3753    
3754     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3755    
3756     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3757     latter must appear before anything that relies on it in the pattern.
3758    
3759    
3760 nigel 17 Version 1.07 16-Feb-98
3761     ----------------------
3762    
3763     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3764     repeat of a potentially empty string).
3765    
3766    
3767 nigel 15 Version 1.06 23-Jan-98
3768     ----------------------
3769    
3770     1. Added Markus Oberhumer's little patches for C++.
3771    
3772     2. Literal strings longer than 255 characters were broken.
3773    
3774