/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log


Revision 501 - (hide annotations) (download)
Sun Mar 7 11:49:54 2010 UTC (4 years, 8 months ago) by ph10
File size: 184033 byte(s)
Preparation code for future (*MARK) support.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 491 Version 8.02 01-Mar-2010
5     ------------------------
6    
7     1. The Unicode data tables have been updated to Unicode 5.2.0.
8    
9 ph10 492 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
10     configured.
11 ph10 493
12     3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
13     original author of that file, following a query about its status.
14 ph10 494
15     4. On systems that do not have stdint.h (e.g. Solaris), check for and include
16     inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
17 ph10 496
18     5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
19     quantifier applied to a forward-referencing subroutine call, could compile
20     incorrect code or give the error "internal error: previously-checked
21     referenced subpattern not found".
22 ph10 497
23     6. Both MS Visual Studio and Symbian OS have problems with initializing
24     variables to point to external functions. For these systems, therefore,
25     pcre_malloc etc. are now initialized to local functions that call the
26     relevant global functions.
27 ph10 498
28     7. There were two entries missing in the vectors called coptable and poptable
29     in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
30     I've fixed the data, and added a kludgy way of testing at compile time that
31     the lengths are correct (equal to the number of opcodes).
32 ph10 499
33     8. Following on from 7, I added a similar kludge to check the length of the
34     eint vector in pcreposix.c.
35    
36     9. Error texts for pcre_compile() are held as one long string to avoid too
37     much relocation at load time. To find a text, the string is searched,
38     counting zeros. There was no check for running off the end of the string,
39     which could happen if a new error number was added without updating the
40     string.
41 ph10 500
42     10. \K gave a compile-time error if it appeared in a lookbehind assersion.
43    
44     11. \K was not working if it appeared in an atomic group or in a group that
45     was called as a "subroutine", or in an assertion. Perl 5.11 documents that
46     \K is "not well defined" if used in an assertion. PCRE now accepts it if
47     the assertion is positive, but not if it is negative.
48 ph10 501
49     12. Change 11 fortuitously reduced the size of the stack frame used in the
50     "match()" function of pcre_exec.c by one pointer. Forthcoming
51     implementation of support for (*MARK) will need an extra pointer on the
52     stack; I have reserved it now, so that the stack frame size does not
53     decrease.
54 ph10 491
55 ph10 492
56 ph10 489 Version 8.01 19-Jan-2010
57     ------------------------
58 ph10 471
59     1. If a pattern contained a conditional subpattern with only one branch (in
60 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
61 ph10 473 computed the wrong minimum data length (which is of course zero for such
62 ph10 489 subpatterns). This could cause incorrect "no match" results.
63 ph10 473
64     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
65 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
66     "internal error: code overflow at offset...". This happened only when
67 ph10 473 the reset was to the original external option setting. (An optimization
68     abstracts leading options settings into an external setting, which was the
69 ph10 472 cause of this.)
70 ph10 471
71 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
72     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
73     assertion pattern did not match (meaning that the assertion was true), it
74     was incorrectly treated as false if the SKIP had been reached during the
75     matching. This also applied to assertions used as conditions.
76 ph10 471
77 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
78     assertion subpattern, including such a pattern used as a condition,
79     unpredictable results occurred, instead of the error return
80     PCRE_ERROR_DFA_UITEM.
81 ph10 478
82 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
83     situation when an empty string is matched. It now does the fancy magic
84 ph10 478 stuff that is necessary.
85    
86     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
87 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
88 ph10 478
89 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
90     as part of something else:
91 ph10 478
92     (a) Change DEBUG to PCRE_DEBUG.
93    
94     (b) In pcre_compile(), rename the member of the "branch_chain" structure
95     called "current" as "current_branch", to prevent a collision with the
96 ph10 475 Linux macro when compiled as a kernel module.
97 ph10 478
98     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
99     prevent a collision with the Linux macro when compiled as a kernel
100 ph10 475 module.
101 ph10 478
102 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
103     cast potentially large values to (double). This has been changed to that
104 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
105     instead, thus avoiding the use of floating point arithmetic. (There is no
106     other use of FP in PCRE.) If int64_t is not found, the fallback is to
107     double.
108    
109     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
110 ph10 476 2005 (difference between two addresses compared to an unsigned value).
111 ph10 473
112 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
113     custom one, because of the following reported problem in Windows:
114 ph10 473
115 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
116 ph10 489 under Win32.
117 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
118 ph10 489 therefore missing the function definition.
119 ph10 478 - The compiler thus generates a "C" signature for the test function.
120     - The linker fails to find the "C" function.
121     - PCRE fails to configure if asked to do so against libbz2.
122 ph10 486
123 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
124     messages were output:
125 ph10 478
126 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
127     rerunning libtoolize, to keep the correct libtool macros in-tree.
128     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
129 ph10 486
130 ph10 479 I have done both of these things.
131 ph10 486
132 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
133 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
134     runaway infinite recursion. I updated the discussion in the pcrestack man
135     page.
136    
137     13. Now that we have gone to the x.xx style of version numbers, the minor
138     version may start with zero. Using 08 or 09 is a bad idea because users
139     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
140     interpreted as invalid octal numbers. I've updated the previous comment in
141     configure.ac, and also added a check that gives an error if 08 or 09 are
142 ph10 481 used.
143 ph10 486
144 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
145 ph10 483 causing partial matching to fail when the end of the subject matched \W
146     in a UTF-8 pattern where \W was quantified with a minimum of 3.
147 ph10 486
148 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
149 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
150 ph10 483 their definitions. The declarations used "const uschar *" and the
151     definitions used USPTR. Even though USPTR is normally defined as "const
152     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
153     reported that: "This difference in casting confuses some C++ compilers, for
154     example, SunCC recognizes above declarations as different functions and
155 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
156 ph10 483 USPTR.
157 ph10 486
158     16. GNU libtool is named differently on some systems. The autogen.sh script now
159 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
160     (FreeBSD).
161 ph10 478
162 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
163     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
164     comment: "Figure out how to create a longlong from a string: strtoll and
165     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
166     instance, but it only takes 2 args instead of 3!"
167 ph10 479
168 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
169     specification, with a corresponding code fix. A pattern such as
170     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
171     refers, was giving matches when it shouldn't. For example, xa=xaaa would
172     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
173     same bug. Such groups have to be quantified to be useful, or contained
174     inside another quantified group. (If there's no repetition, the reference
175     can never match.) The problem arises because, having left the group and
176     moved on to the rest of the pattern, a later failure that backtracks into
177     the group uses the captured value from the final iteration of the group
178     rather than the correct earlier one. I have fixed this in PCRE by forcing
179     any group that contains a reference to itself to be an atomic group; that
180     is, there cannot be any backtracking into it once it has completed. This is
181     similar to recursive and subroutine calls.
182 ph10 486
183 ph10 488
184 ph10 469 Version 8.00 19-Oct-09
185 ph10 418 ----------------------
186    
187     1. The table for translating pcre_compile() error codes into POSIX error codes
188 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
189     being within the table. This could lead to an OK return being given in
190 ph10 418 error.
191 ph10 461
192     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
193     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
194     in a Windows environment.
195    
196 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
197     zero, as does GNU grep. However, pcregrep was also printing all files when
198     --files-with-matches was added. Now, when both options are given, it prints
199     counts only for those files that have at least one match. (GNU grep just
200 ph10 461 prints the file name in this circumstance, but including the count seems
201     more useful - otherwise, why use --count?) Also ensured that the
202 ph10 420 combination -clh just lists non-zero counts, with no names.
203 ph10 461
204     4. The long form of the pcregrep -F option was incorrectly implemented as
205     --fixed_strings instead of --fixed-strings. This is an incompatible change,
206     but it seems right to fix it, and I didn't think it was worth preserving
207     the old behaviour.
208    
209     5. The command line items --regex=pattern and --regexp=pattern were not
210 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
211 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
212 ph10 422 which are compatible with GNU grep; these now work.
213 ph10 461
214     6. No libpcreposix.pc file was created for pkg-config; there was just
215 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
216 ph10 461
217 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
218 ph10 461 when UCP support is not needed, by modifying the Python script that
219 ph10 425 generates it from Unicode data files. This should not matter if the module
220     is correctly used as a library, but I received one complaint about 50K of
221     unwanted data. My guess is that the person linked everything into his
222     program rather than using a library. Anyway, it does no harm.
223 ph10 461
224 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
225 ph10 461 was a minimum greater than 1 for a wide character in a possessive
226 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
227     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
228     character. Chaos in the form of incorrect output or a compiling loop could
229     result.
230 ph10 461
231 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
232 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
233 ph10 426 partially matched by this function. In addition, if there are at least two
234 ph10 435 slots in the offset vector, the offset of the earliest inspected character
235     for the match and the offset of the end of the subject are set in them when
236 ph10 461 PCRE_ERROR_PARTIAL is returned.
237    
238 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
239     synonymous with PCRE_PARTIAL, for backwards compatibility, and
240     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
241 ph10 462 and may be more useful for multi-segment matching.
242 ph10 461
243     11. Partial matching with pcre_exec() is now more intuitive. A partial match
244     used to be given if ever the end of the subject was reached; now it is
245     given only if matching could not proceed because another character was
246     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
247     string "Z", which now yields "no match" instead of "partial match". In the
248     case of pcre_dfa_exec(), "no match" is given if every matching path for the
249     final character ended with (*FAIL).
250    
251 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
252 ph10 461 if the pattern had a "must contain" character that was already found in the
253 ph10 428 earlier partial match, unless partial matching was again requested. For
254     example, with the pattern /dog.(body)?/, the "must contain" character is
255     "g". If the first part-match was for the string "dog", restarting with
256 ph10 435 "sbody" failed. This bug has been fixed.
257 ph10 461
258     13. The string returned by pcre_dfa_exec() after a partial match has been
259     changed so that it starts at the first inspected character rather than the
260     first character of the match. This makes a difference only if the pattern
261     starts with a lookbehind assertion or \b or \B (\K is not supported by
262     pcre_dfa_exec()). It's an incompatible change, but it makes the two
263 ph10 435 matching functions compatible, and I think it's the right thing to do.
264 ph10 461
265 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
266 ph10 461 so that the demonstration program is easily available in environments where
267     PCRE has not been installed from source.
268    
269 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
270 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
271     library.
272 ph10 461
273 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
274 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
275 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
276 ph10 433 these options useful.
277 ph10 461
278     17. If a caller to the POSIX matching function regexec() passes a non-zero
279 ph10 438 value for nmatch with a NULL value for pmatch, the value of
280 ph10 461 nmatch is forced to zero.
281    
282 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
283 ph10 461 the diff command, as RunTest does. It now checks in the same way as
284 ph10 437 RunTest, and also checks for the -b option.
285 ph10 461
286 ph10 438 19. If an odd number of negated classes containing just a single character
287     interposed, within parentheses, between a forward reference to a named
288 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
289     an internal error, complaining that it could not find the referenced
290 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
291 ph10 461 [The bug was that it was starting one character too far in when skipping
292     over the character class, thus treating the ] as data rather than
293     terminating the class. This meant it could skip too much.]
294    
295 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
296 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
297 ph10 442 to have an empty string match not at the start, even when the pattern is
298 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
299    
300 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
301 ph10 461 than the maximum at the outer level, the higher number was returned, but
302     with unset values at the outer level. The correct (outer level) value is
303 ph10 446 now given.
304 ph10 461
305 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
306     PCRE did not set those parentheses (unlike Perl). I have now found a way to
307     make it do so. The string so far is captured, making this feature
308     compatible with Perl.
309 ph10 461
310     23. The tests have been re-organized, adding tests 11 and 12, to make it
311 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
312 ph10 461
313 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
314 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
315     does. Neither allows recursion.
316    
317     25. I finally figured out how to implement a request to provide the minimum
318     length of subject string that was needed in order to match a given pattern.
319     (It was back references and recursion that I had previously got hung up
320     on.) This code has now been added to pcre_study(); it finds a lower bound
321 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
322     bound, but using it to avoid searching strings that are too short does give
323     some useful speed-ups. The value is available to calling programs via
324     pcre_fullinfo().
325 ph10 461
326 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
327     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
328     study optimizations had never been tested with that matching function.
329     Oops. What is worse, even when it was passed study data, there was a bug in
330     pcre_dfa_exec() that meant it never actually used it. Double oops. There
331     were also very few tests of studied patterns with pcre_dfa_exec().
332 ph10 461
333 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
334     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
335     on the other side of the coin, they are no longer allowed to have different
336     names, because these cannot be distinguished in PCRE, and this has caused
337     confusion. (This is a difference from Perl.)
338 ph10 461
339     28. When duplicate subpattern names are present (necessarily with different
340     numbers, as required by 27 above), and a test is made by name in a
341     conditional pattern, either for a subpattern having been matched, or for
342     recursion in such a pattern, all the associated numbered subpatterns are
343 ph10 459 tested, and the overall condition is true if the condition is true for any
344     one of them. This is the way Perl works, and is also more like the way
345     testing by number works.
346 ph10 418
347 ph10 461
348 ph10 412 Version 7.9 11-Apr-09
349 ph10 376 ---------------------
350    
351 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
352 ph10 376 (pcretest), all targets were linked against these libraries. This included
353     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
354     libraries. This caused unwanted dependencies to be created. This problem
355 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
356 ph10 376 pcretest is linked with readline.
357 ph10 392
358 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
359     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
360     moved outside it again, because FALSE and TRUE are already defined in AIX,
361     but BOOL is not.
362 ph10 392
363     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
364 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
365 ph10 392
366 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
367     hyphens) following file names and line numbers when outputting matching
368 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
369 ph10 376 wording for the --colour (or --color) option.
370 ph10 392
371 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
372     was not coloured; this is different to GNU grep, so I have changed it to be
373     the same.
374 ph10 392
375 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
376 ph10 392 each matching line was coloured. Now it goes on to look for further matches
377     of any of the test patterns, which is the same behaviour as GNU grep.
378    
379     7. A pattern that could match an empty string could cause pcregrep to loop; it
380     doesn't make sense to accept an empty string match in pcregrep, so I have
381 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
382     seems to be how GNU grep behaves.
383 ph10 392
384 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
385 ph10 392 start or after a newline", because the conditional assertion was not being
386     correctly handled. The rule now is that both the assertion and what follows
387     in the first alternative must satisfy the test.
388    
389 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
390 ph10 399 condition was an assertion, PCRE could crash during matching, both with
391     pcre_exec() and pcre_dfa_exec().
392 ph10 392
393     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
394     used for matching.
395    
396     11. Unicode property support in character classes was not working for
397 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
398 ph10 388
399 ph10 392 12. Added the -M command line option to pcretest.
400    
401 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
402 ph10 389
403     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
404 ph10 390
405 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
406 ph10 390 wrapper.
407 ph10 392
408 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
409 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
410 ph10 391 string constants.
411 ph10 405
412 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
413     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
414 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
415     these, but not everybody uses configure.
416    
417     19. A conditional group that had only one branch was not being correctly
418     recognized as an item that could match an empty string. This meant that an
419     enclosing group might also not be so recognized, causing infinite looping
420     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
421     with the subject "ab", where knowledge that the repeated group can match
422 ph10 396 nothing is needed in order to break the loop.
423 ph10 405
424 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
425 ph10 405 exec(), but without supplying a callout function, matching went wrong.
426    
427     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
428     leak if the size of the offset vector was greater than 30. When the vector
429     is smaller, the saved offsets during recursion go onto a local stack
430     vector, but for larger vectors malloc() is used. It was failing to free
431     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
432 ph10 400 error, in fact).
433 ph10 405
434 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
435 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
436     problem, but was untidy.
437 ph10 376
438 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
439     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
440     included within another project.
441 ph10 411
442 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
443     slightly modified by me:
444 ph10 411
445     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
446     not building pcregrep.
447    
448 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
449 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
450    
451 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
452     duplicate group numbers, could behave incorrectly or give incorrect errors,
453     because when scanning forward to find the reference group, PCRE was not
454     taking into account the duplicate group numbers. A pattern such as
455     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
456 ph10 411
457     26. Changed a few more instances of "const unsigned char *" to USPTR, making
458     the feature of a custom pointer more persuasive (as requested by a user).
459 ph10 416
460 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
461 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
462     pre-defined.
463 ph10 392
464 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
465    
466 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
467     in the configuration summary.
468 ph10 405
469 ph10 411
470 ph10 374 Version 7.8 05-Sep-08
471 ph10 349 ---------------------
472    
473     1. Replaced UCP searching code with optimized version as implemented for Ad
474     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
475 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
476     to 5 times on some simple patterns that I tested. Permission was given to
477     distribute the MultiStage2.py script that generates the tables (it's not in
478     the tarball, but is in the Subversion repository).
479 ph10 349
480 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
481     scripts.
482 ph10 358
483 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
484     a group with a zero qualifier. The result of the study could be incorrect,
485 ph10 358 or the function might crash, depending on the pattern.
486    
487     4. Caseless matching was not working for non-ASCII characters in back
488 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
489 ph10 358 It now works when Unicode Property Support is available.
490    
491 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
492     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
493     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
494 ph10 358 truncation.
495 ph10 349
496 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
497    
498 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
499     pointers, in case they are 64-bit values.
500 ph10 371
501     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
502     test 2 if it fails.
503    
504 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
505 ph10 371 and a #define of that name to empty if it is not externally set. This is to
506     allow users of MSVC to set it if necessary.
507    
508     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
509 ph10 359 the convenience functions in the pcre_get.c source file.
510 ph10 371
511 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
512     could cause overwriting and/or a crash. This command provoked a crash in
513 ph10 371 some environments:
514    
515     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
516    
517 ph10 360 This potential security problem was recorded as CVE-2008-2371.
518 ph10 371
519 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
520     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
521 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
522 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
523     pcretest so that it places the subject at the end of its malloc-ed buffer.
524 ph10 371
525 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
526 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
527    
528 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
529 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
530     first line. This applied both to normal and DFA matching.
531    
532 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
533 ph10 371 /^[^d]*?$/8 failed to match "abc".
534 ph10 351
535 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
536    
537     17. Make it more clear in the documentation that values returned from
538 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
539 ph10 357
540 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
541 ph10 368
542 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
543     supplied by Stefan Weber. I made a further small update for 7.8 because
544 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
545     replaced by pcre_ucd.c.
546 ph10 371
547 ph10 373
548 ph10 347 Version 7.7 07-May-08
549 ph10 321 ---------------------
550    
551     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
552 ph10 345 a string to a long long, pretend we don't even have a long long." This is
553 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
554 ph10 345
555 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
556     pre-7.6 versions, which defined a global no_arg variable instead of putting
557 ph10 332 it in the RE class. (See also #8 below.)
558 ph10 345
559     3. Remove a line of dead code, identified by coverity and reported by Nuno
560     Lopes.
561    
562 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
563 ph10 321
564 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
565 ph10 345 of files, instead of just to the final components.
566    
567 ph10 324 (2) If there was more than one level of directory, the subdirectories were
568     skipped unless they satisfied the include/exclude conditions. This is
569     inconsistent with GNU grep (and could even be seen as contrary to the
570     pcregrep specification - which I improved to make it absolutely clear).
571     The action now is always to scan all levels of directory, and just
572     apply the include/exclude patterns to regular files.
573 ph10 345
574 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
575 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
576    
577 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
578 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
579 ph10 326 doesn't support NULs in patterns.
580 ph10 345
581     7. Added some missing "const"s to declarations of static tables in
582     pcre_compile.c and pcre_dfa_exec.c.
583    
584 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
585 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
586 ph10 345 first patch. And a third patch - this was a messy problem.)
587 ph10 321
588 ph10 345 9. Applied Craig's patch to remove the use of push_back().
589    
590 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
591     matching function regexec().
592 ph10 345
593     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
594     which, however, unlike Perl's \g{...}, are subroutine calls, not back
595 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
596     Oniguruma does).
597 ph10 345
598     12. Previously, a group with a zero repeat such as (...){0} was completely
599 ph10 335 omitted from the compiled regex. However, this means that if the group
600     was called as a subroutine from elsewhere in the pattern, things went wrong
601 ph10 345 (an internal error was given). Such groups are now left in the compiled
602     pattern, with a new opcode that causes them to be skipped at execution
603 ph10 335 time.
604 ph10 345
605 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
606     to the way PCRE behaves:
607 ph10 345
608 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
609 ph10 345
610     (b) A back reference to an unmatched subpattern matches an empty string
611 ph10 336 (Perl fails the current match path).
612 ph10 345
613 ph10 341 (c) A data ] in a character class must be notated as \] because if the
614 ph10 345 first data character in a class is ], it defines an empty class. (In
615 ph10 341 Perl it is not possible to have an empty class.) The empty class []
616     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
617     The negative empty class [^] matches any one character, independently
618     of the DOTALL setting.
619 ph10 345
620     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
621 ph10 340 non-existent subpattern following a character class starting with ']' and
622     containing () gave an internal compiling error instead of "reference to
623     non-existent subpattern". Fortunately, when the pattern did exist, the
624 ph10 345 compiled code was correct. (When scanning forwards to check for the
625 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
626 ph10 345 the class, so got the count wrong. When actually compiling, the reference
627 ph10 340 was subsequently set up correctly.)
628 ph10 345
629 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
630 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
631     other assertions are supported. I have made pcre_dfa_exec() support
632     (*FAIL).
633    
634 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
635 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
636     cannot be changed at match time, I realized I could make a small
637     improvement to matching performance by compiling OP_ALLANY instead of
638     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
639     on the OP_ANY path.
640    
641     17. Compiling pcretest on Windows with readline support failed without the
642 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
643 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
644    
645 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
646 ph10 345 ncurses library to be included for pcretest when ReadLine support is
647     requested, but also to allow for it to be overridden. This patch came from
648     Daniel Bergström.
649 ph10 347
650 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
651 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
652     any errors with the current Unicode tables. Thanks to Peter Kankowski for
653     spotting this.
654 ph10 324
655 ph10 332
656 ph10 319 Version 7.6 28-Jan-08
657 ph10 300 ---------------------
658    
659 ph10 302 1. A character class containing a very large number of characters with
660     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
661     overflow.
662 ph10 309
663     2. Patch to cut out the "long long" test in pcrecpp_unittest when
664     HAVE_LONG_LONG is not defined.
665    
666 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
667 ph10 304 bring them up to date and include new features. This patch includes:
668 ph10 309
669 ph10 304 - Fixed PH's badly added libz and libbz2 support.
670     - Fixed a problem with static linking.
671 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
672 ph10 304 - Fixed dftables problem and added an option.
673     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
674     HAVE_LONG_LONG.
675     - Added readline support for pcretest.
676 ph10 309 - Added an listing of the option settings after cmake has run.
677    
678 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
679     "pcre.dll" under mingw when using Configure/Make. I added stuff to
680     Makefile.am that cause it to include this special target, without
681     affecting anything else. Note that the same mingw target plus all
682     the other distribution libraries and programs are now supported
683     when configuring with CMake (see 6 below) instead of with
684     Configure/Make.
685 ph10 309
686 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
687     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
688 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
689     solves the problem, but it does no harm.
690 ph10 313
691 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
692 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
693 ph10 314 with CMake, and also correct the comment about stack recursion.
694 ph10 313
695 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
696 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
697     of a program that users should build themselves after PCRE is installed, so
698     building it automatically is not really right. What is more, it gave
699 ph10 312 trouble in some build environments.
700 ph10 300
701 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
702 ph10 308
703 ph10 319
704 ph10 298 Version 7.5 10-Jan-08
705 ph10 263 ---------------------
706    
707     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
708     values in parens when parsing an RE using the C++ wrapper."
709 ph10 286
710 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
711     Characters greater than 255 were excluded from the class instead of being
712     included.
713 ph10 286
714     3. The same bug as (2) above applied to negated POSIX classes such as
715 ph10 265 [:^space:].
716 ph10 286
717 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
718     defined or documented. It seems to have been a typo for PCRE_STATIC, so
719 ph10 286 I have changed it.
720    
721 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
722 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
723     first named subpattern whose name started with "a" (in other words, the
724 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
725     expected" is now given for (?&) (a zero-length name), and this patch also
726     makes it give the same error for \k'' (previously it complained that that
727     was a reference to a non-existent subpattern).
728 ph10 286
729 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
730 ph10 286 this is right because (?- can be followed by option settings as well as by
731 ph10 269 digits. I have, however, made the messages clearer.
732 ph10 286
733 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
734     than the number used in the conditional) now cause a compile-time error.
735     This is actually not compatible with Perl, which accepts such patterns, but
736     treats the conditional as always being FALSE (as PCRE used to), but it
737     seems to me that giving a diagnostic is better.
738 ph10 286
739 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
740 ph10 275 and messages.
741 ph10 286
742     9. Fix two occurrences of "backslash" in comments that should have been
743     "backspace".
744    
745     10. Remove two redundant lines of code that can never be obeyed (their function
746     was moved elsewhere).
747    
748     11. The program that makes PCRE's Unicode character property table had a bug
749     which caused it to generate incorrect table entries for sequences of
750 ph10 277 characters that have the same character type, but are in different scripts.
751 ph10 286 It amalgamated them into a single range, with the script of the first of
752 ph10 277 them. In other words, some characters were in the wrong script. There were
753     thirteen such cases, affecting characters in the following ranges:
754 ph10 286
755 ph10 277 U+002b0 - U+002c1
756     U+0060c - U+0060d
757 ph10 286 U+0061e - U+00612
758 ph10 277 U+0064b - U+0065e
759     U+0074d - U+0076d
760     U+01800 - U+01805
761     U+01d00 - U+01d77
762     U+01d9b - U+01dbf
763     U+0200b - U+0200f
764     U+030fc - U+030fe
765     U+03260 - U+0327f
766     U+0fb46 - U+0fbb1
767     U+10450 - U+1049d
768 ph10 286
769 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
770     compatible with GNU grep in that, if there was more than one match in a
771     line, it showed only the first of them. It now behaves in the same way as
772     GNU grep.
773 ph10 286
774     13. If the -o and -v options were combined for pcregrep, it printed a blank
775     line for every non-matching line. GNU grep prints nothing, and pcregrep now
776     does the same. The return code can be used to tell if there were any
777     non-matching lines.
778    
779 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
780    
781     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
782 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
783 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
784     and both kinds of lookbehind were skipped).
785    
786 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
787 ph10 284 inclusion of <windows.h> to before rather than after the definition of
788     INVALID_FILE_ATTRIBUTES (patch from David Byron).
789 ph10 263
790 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
791 ph10 286 character property caused pcre_compile() to compile bad code, which led at
792     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
793     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
794     caused the error; without that there was no problem.
795 ph10 263
796 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
797 ph10 286
798 ph10 289 19. Added --enable-pcretest-libreadline.
799 ph10 286
800 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
801 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
802 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
803     later patch that removed the other one (the right fix) and added unit tests
804     that check the return values (which was not done before).
805 ph10 292
806 ph10 291 21. Several CMake things:
807 ph10 287
808 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
809 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
810 ph10 288
811 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
812     linked with the newly-built libraries, not previously installed ones.
813 ph10 291
814 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
815 ph10 298
816     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
817     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
818     UTF-8 newline character). The key issue is that the pattern starts .*;
819     this means that the match must be either at the beginning, or after a
820     newline. The bug was in the code for advancing after a failed match and
821     checking that the new position followed a newline. It was not taking
822 ph10 294 account of UTF-8 characters correctly.
823 ph10 298
824     23. PCRE was behaving differently from Perl in the way it recognized POSIX
825     character classes. PCRE was not treating the sequence [:...:] as a
826     character class unless the ... were all letters. Perl, however, seems to
827     allow any characters between [: and :], though of course it rejects as
828     unknown any "names" that contain non-letters, because all the known class
829     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
830     for example, whereas PCRE did not - it did not recognize a POSIX character
831     class. This seemed a bit dangerous, so the code has been changed to be
832     closer to Perl. The behaviour is not identical to Perl, because PCRE will
833     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
834     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
835     Perl does, and where it didn't before.
836    
837 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
838     Windows environments %n is disabled by default.
839 ph10 292
840    
841 ph10 260 Version 7.4 21-Sep-07
842 ph10 230 ---------------------
843    
844     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
845 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
846     LF". That isn't really right - the whole point of the change was to try to
847     help when there was an actual mention of one of the two characters. So now
848     the change happens only if \r or \n (or a literal CR or LF) character is
849 ph10 230 encountered.
850 ph10 231
851     2. The 32-bit options word was also used for 6 internal flags, but the numbers
852     of both had grown to the point where there were only 3 bits left.
853     Fortunately, there was spare space in the data structure, and so I have
854     moved the internal flags into a new 16-bit field to free up more option
855 ph10 230 bits.
856 ph10 231
857     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
858     but did not set the internal JCHANGED flag - either of these is enough to
859     control the way the "get" function works - but the PCRE_INFO_JCHANGED
860     facility is supposed to tell if (?J) was ever used, so now (?J) at the
861 ph10 230 start sets both bits.
862    
863 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
864     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
865 ph10 230
866 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
867    
868     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
869 ph10 233 compatibility, even though it is no longer used.
870 ph10 243
871     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
872 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
873 ph10 259 windows.h file is present (where different names are used). [This was
874 ph10 257 reversed later after testing - see 16 below.]
875 ph10 243
876     8. Changed all #include <config.h> to #include "config.h". There were also
877 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
878 ph10 243
879 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
880 ph10 243 sequence off the lines that it output.
881    
882     10. It was pointed out to me that arrays of string pointers cause lots of
883     relocations when a shared library is dynamically loaded. A technique of
884     using a single long string with a table of offsets can drastically reduce
885     these. I have refactored PCRE in four places to do this. The result is
886 ph10 240 dramatic:
887 ph10 243
888 ph10 240 Originally: 290
889     After changing UCP table: 187
890 ph10 243 After changing error message table: 43
891 ph10 240 After changing table of "verbs" 36
892     After changing table of Posix names 22
893 ph10 243
894 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
895 ph10 247
896 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
897 ph10 247 unicode-properties was also set.
898    
899 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
900 ph10 231
901 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
902     checked only for CRLF.
903 ph10 233
904 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
905    
906 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
907 ph10 253
908 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
909 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
910     entirely. This removes changes made in 7 above.
911 ph10 256
912 ph10 261 17. The CMake files have been updated, and there is now more information about
913     building with CMake in the NON-UNIX-USE document.
914 ph10 257
915 ph10 261
916 ph10 228 Version 7.3 28-Aug-07
917 ph10 157 ---------------------
918    
919 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
920     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
921     brackets there is not right, since it causes compilers to look for an
922     installed pcre.h, not the version that is in the source that is being
923     compiled (which of course may be different). I have changed it back to:
924 ph10 197
925 ph10 189 #include "pcre.h"
926 ph10 197
927     I have a vague recollection that the change was concerned with compiling in
928     different directories, but in the new build system, that is taken care of
929     by the VPATH setting the Makefile.
930    
931 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
932     when the subject happened to end in the byte 0x85 (e.g. if the last
933     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
934     characters but of course it shouldn't be taken as a newline when it is part
935     of another character. The bug was that, for an unlimited repeat of . in
936     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
937     characters when looking for a newline.
938 ph10 197
939     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
940    
941     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
942     in debug output.
943    
944 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
945     long printing in the pcrecpp unittest when running under MinGW.
946 ph10 189
947 ph10 197 6. ESC_K was left out of the EBCDIC table.
948 ph10 189
949 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
950     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
951     limit also applies to "virtual nesting" when a pattern is recursive, and in
952     this case 1000 isn't so big. I have been able to remove this limit at the
953     expense of backing off one optimization in certain circumstances. Normally,
954     when pcre_exec() would call its internal match() function recursively and
955     immediately return the result unconditionally, it uses a "tail recursion"
956     feature to save stack. However, when a subpattern that can match an empty
957     string has an unlimited repetition quantifier, it no longer makes this
958     optimization. That gives it a stack frame in which to save the data for
959     checking that an empty string has been matched. Previously this was taken
960     from the 1000-entry workspace that had been reserved. So now there is no
961     explicit limit, but more stack is used.
962 ph10 189
963 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
964     syntax that is required for Windows, and which was going wrong for the
965     pcreposix and pcrecpp parts of the library. These were overlooked when this
966     problem was solved for the main library.
967 ph10 197
968 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
969     the size of patterns that contain repeated groups with explicit upper
970     limits. As the maximum quantifier is 65535, the maximum group length was
971     set at 30,000 so that the product of these two numbers did not overflow a
972     32-bit integer. However, it turns out that people want to use groups that
973     are longer than 30,000 bytes (though not repeat them that many times).
974     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
975     made it possible to implement the integer overflow checks in a much more
976     dynamic way, which I have now done. The artificial limitation on group
977     length has been removed - we now have only the limit on the total length of
978     the compiled pattern, which depends on the LINK_SIZE setting.
979 ph10 208
980     10. Fixed a bug in the documentation for get/copy named substring when
981     duplicate names are permitted. If none of the named substrings are set, the
982     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
983     empty string.
984    
985     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
986     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
987     because the ] is interpreted as the first data character and the
988     terminating ] is not found. PCRE has been made compatible with Perl in this
989     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
990     cause memory overwriting.
991    
992 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
993     string has been matched (to stop an infinite loop). It was not recognizing
994 ph10 208 a conditional subpattern that could match an empty string if that
995 ph10 206 subpattern was within another subpattern. For example, it looped when
996 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
997 ph10 206 condition was not nested. This bug has been fixed.
998 ph10 208
999 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1000     past the start of the subject in the presence of bytes with the top bit
1001     set, for example "\x8aBCD".
1002 ph10 211
1003 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1004     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1005 ph10 200
1006 ph10 211 14. Optimized (?!) to (*FAIL).
1007 ph10 202
1008 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1009     This restricts code points to be within the range 0 to 0x10FFFF, excluding
1010     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1011     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1012     does: it's just the validity check that is more restrictive.
1013 ph10 220
1014     16. Inserted checks for integer overflows during escape sequence (backslash)
1015     processing, and also fixed erroneous offset values for syntax errors during
1016     backslash processing.
1017    
1018 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1019 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1020    
1021 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1022     caused an overrun.
1023 ph10 220
1024     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1025     something other than just ASCII characters) inside a group that had an
1026     unlimited repeat caused a loop at compile time (while checking to see
1027     whether the group could match an empty string).
1028    
1029 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1030     [\P{Any}] did so. (Error in the code for printing property names.)
1031 ph10 210
1032 ph10 220 21. An orphan \E inside a character class could cause a crash.
1033    
1034     22. A repeated capturing bracket such as (A)? could cause a wild memory
1035 ph10 218 reference during compilation.
1036 ph10 220
1037     23. There are several functions in pcre_compile() that scan along a compiled
1038     expression for various reasons (e.g. to see if it's fixed length for look
1039 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1040 ph10 220 present in the pattern. These operators have additional parameters compared
1041     with \d, etc, and these were not being taken into account when moving along
1042 ph10 218 the compiled data. Specifically:
1043 ph10 220
1044     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1045     length.
1046    
1047     (b) An item such as \pL+ within a repeated group could cause crashes or
1048 ph10 218 loops.
1049 ph10 220
1050 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1051 ph10 220 "reference to non-existent subpattern" error.
1052    
1053 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1054    
1055 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1056 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1057 ph10 211
1058 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1059 ph10 218
1060 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1061 ph10 223 character were causing crashes (broken optimization).
1062 ph10 227
1063 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1064 ph10 227 \p or \P) caused a compile-time loop.
1065    
1066 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1067     break. For example, the unstudied pattern [\r\n]A does not match the string
1068     "\r\nA" because change 7.0/46 below moves the current point on by two
1069     characters after failing to match at the start. However, the pattern \nA
1070 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1071     the same is true. There doesn't seem any very clean way out of this, but
1072     what I have chosen to do makes the common cases work: PCRE now takes note
1073     of whether there can be an explicit match for \r or \n anywhere in the
1074     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1075     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1076     pattern has explicit CR or LF references.
1077 ph10 222
1078 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1079 ph10 223
1080 ph10 227
1081 ph10 189 Version 7.2 19-Jun-07
1082     ---------------------
1083    
1084 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1085     which is apparently normally available under Windows.
1086 ph10 159
1087     2. Re-jig the pcregrep tests with different newline settings in an attempt
1088     to make them independent of the local environment's newline setting.
1089 ph10 157
1090 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1091 ph10 165
1092 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1093     was not 2, because the output contained actual offsets. The recent new
1094 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1095     usable with all link sizes.
1096    
1097 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1098     stack recursion. This gives a massive performance boost under BSD, but just
1099 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1100 ph10 164 in all cases.
1101 ph10 172
1102 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1103 ph10 172
1104 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1105     recursion call. It refers to the nth most recently opened parentheses.
1106 ph10 172
1107 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1108 ph10 172 to be opened parentheses.
1109    
1110     (c) Conditions that refer to capturing parentheses can be specified
1111 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1112 ph10 172
1113 ph10 168 (d) \K resets the start of the current match so that everything before
1114 ph10 172 is not part of it.
1115    
1116 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1117 ph10 172
1118 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1119 ph10 172 reference syntax.
1120 ph10 182
1121 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1122 ph10 182 alternative starts with the same number.
1123 ph10 172
1124 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1125    
1126 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1127     PCRE_INFO_JCHANGED.
1128    
1129     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1130     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1131 ph10 170 for detecting groups that can match an empty string.
1132 ph10 159
1133 ph10 172 9. A pattern with a very large number of alternatives (more than several
1134     hundred) was running out of internal workspace during the pre-compile
1135     phase, where pcre_compile() figures out how much memory will be needed. A
1136     bit of new cunning has reduced the workspace needed for groups with
1137     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1138     workspace instead of running out of the 4096 that are available.
1139 ph10 182
1140 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1141 ph10 172
1142 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1143     The report of the bug said:
1144 ph10 182
1145 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1146     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1147 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1148 ph10 185
1149 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1150 ph10 185 it matched the wrong number of bytes.
1151 ph10 172
1152 ph10 179
1153 ph10 155 Version 7.1 24-Apr-07
1154 ph10 98 ---------------------
1155    
1156 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1157 ph10 122 that is more "standard", making use of automake and other Autotools. There
1158 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1159     on this.
1160 ph10 111
1161     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1162     for recursive directory scanning broke on some systems because the files
1163     are not scanned in any specific order and on different systems the order
1164     was different. A call to "sort" has been inserted into RunGrepTest for the
1165     approprate test as a short-term fix. In the longer term there may be an
1166 ph10 100 alternative.
1167 ph10 111
1168 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1169 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1170     people do their own conversions for various reasons). The problems
1171     concerned the use of low-level troff macros .br and .in. I have therefore
1172     removed all such uses from the man pages (some were redundant, some could
1173 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1174     HTML has been updated to handle .nf/.fi and to complain if it encounters
1175     .br or .in.
1176 ph10 111
1177 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1178 ph10 123 arranged for config.h to be included in the distribution, with the name
1179 ph10 111 config.h.generic, for the benefit of those who have to compile without
1180     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1181    
1182     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1183     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1184 ph10 127 makevp.bat for the current PCRE, using the additional files
1185 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1186 ph10 111
1187     6. A Windows user reported a minor discrepancy with test 2, which turned out
1188     to be caused by a trailing space on an input line that had got lost in his
1189 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1190 ph10 111
1191 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1192 ph10 111 that is needed.
1193    
1194 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1195     as "const" (a) because they are and (b) because it helps the PHP
1196     maintainers who have recently made a script to detect big data structures
1197 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1198     to update Builducptable as well, so it won't revert if ucptable.h is ever
1199 ph10 105 re-created.
1200 ph10 111
1201     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1202 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1203 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1204     support is not required. This saves 1.5-2K of code, which is important in
1205 ph10 107 some applications.
1206 ph10 111
1207 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1208 ph10 111 so as not to refer to the tables, even though these functions will never be
1209     called when UTF-8 support is disabled. Otherwise there are problems with a
1210     shared library.
1211    
1212 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1213    
1214     (a) It was defining its arguments as char * instead of void *.
1215    
1216 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1217     a long time ago when I wrote it, but is no longer the case.
1218    
1219 ph10 118 The emulated memove() is provided for those environments that have neither
1220 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1221 ph10 118 is clearly not the case, as these two bugs were recently reported.
1222 ph10 123
1223 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1224 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1225     pages, and it removes trailing spaces from listed files. It also creates
1226     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1227     case, it wraps all the #defines with #ifndefs. This script should be run
1228 ph10 111 before "make dist".
1229 ph10 123
1230 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1231     with Unicode property support.
1232 ph10 123
1233     (a) For a maximizing quantifier, if the two different cases of the
1234     character were of different lengths in their UTF-8 codings (there are
1235     some cases like this - I found 11), and the matching function had to
1236 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1237     were both the same length.
1238 ph10 123
1239     (b) When PCRE was configured to use the heap rather than the stack for
1240     recursion during matching, it was not correctly preserving the data for
1241     the other case of a UTF-8 character when checking ahead for a match
1242     while processing a minimizing repeat. If the check also involved
1243 ph10 115 matching a wide character, but failed, corruption could cause an
1244     erroneous result when trying to check for a repeat of the original
1245     character.
1246 ph10 123
1247 ph10 116 13. Some tidying changes to the testing mechanism:
1248 ph10 98
1249 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1250     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1251 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1252     this for UTF-8.) The configure.ac script no longer substitutes the
1253     relevant variables.
1254    
1255 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1256     with length and offset values. This means that the output is different
1257     for different internal link sizes. Test 2 is skipped for link sizes
1258     other than 2 because of this, bypassing the problem. Unfortunately,
1259     there was also a test in test 3 (the locale tests) that used /B and
1260 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1261     I have added a new /Z option to pcretest that replaces the length and
1262     offset values with spaces. This is now used to make test 3 independent
1263 ph10 122 of link size. (Test 2 will be tidied up later.)
1264 ph10 123
1265     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1266 ph10 122 segmentation fault instead of returning the appropriate error message.
1267 ph10 134
1268 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1269 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1270     This doesn't seem right; it now treats the CRLF combination as the line
1271     ending, and so does not match in that case. It's only a pattern such as ^$
1272     that would hit this one: something like ^ABC$ would have failed after \r
1273     and then tried again after \r\n.
1274    
1275 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1276 ph10 134 in an attempt to make files that differ only in their line terminators
1277     compare equal. This works on Linux.
1278 ph10 142
1279 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1280     as it exited. This is now fixed, thanks to valgrind.
1281 ph10 142
1282 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1283 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1284     was because its rules for how to advance for /g after matching an empty
1285 ph10 143 string at the end of a line did not allow for this case. They now check for
1286     it specially.
1287 ph10 150
1288     20. pcretest is supposed to handle patterns and data of any length, by
1289     extending its buffers when necessary. It was getting this wrong when the
1290 ph10 147 buffer for a data line had to be extended.
1291 ph10 150
1292 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1293 ph10 150 CRLF as a newline sequence.
1294 ph10 152
1295 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1296 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1297     I have nevertheless tidied it up.
1298 ph10 111
1299 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1300 ph10 123
1301 ph10 153 24. Added a man page for pcre-config.
1302 ph10 152
1303 ph10 153
1304 nigel 93 Version 7.0 19-Dec-06
1305     ---------------------
1306    
1307     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1308     moving to gcc 4.1.1.
1309    
1310     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1311     sys/time.h, which is documented as needed for this function. It doesn't
1312     seem to matter on Linux, but it showed up on some releases of OS X.
1313    
1314     3. It seems that there are systems where bytes whose values are greater than
1315     127 match isprint() in the "C" locale. The "C" locale should be the
1316     default when a C program starts up. In most systems, only ASCII printing
1317     characters match isprint(). This difference caused the output from pcretest
1318     to vary, making some of the tests fail. I have changed pcretest so that:
1319    
1320     (a) When it is outputting text in the compiled version of a pattern, bytes
1321     other than 32-126 are always shown as hex escapes.
1322    
1323     (b) When it is outputting text that is a matched part of a subject string,
1324     it does the same, unless a different locale has been set for the match
1325     (using the /L modifier). In this case, it uses isprint() to decide.
1326    
1327     4. Fixed a major bug that caused incorrect computation of the amount of memory
1328     required for a compiled pattern when options that changed within the
1329     pattern affected the logic of the preliminary scan that determines the
1330     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1331     that the computed length was too small. The symptoms of this bug were
1332     either the PCRE error "internal error: code overflow" from pcre_compile(),
1333     or a glibc crash with a message such as "pcretest: free(): invalid next
1334     size (fast)". Examples of patterns that provoked this bug (shown in
1335     pcretest format) are:
1336    
1337     /(?-x: )/x
1338     /(?x)(?-x: \s*#\s*)/
1339     /((?i)[\x{c0}])/8
1340     /(?i:[\x{c0}])/8
1341    
1342     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1343     is now done differently.
1344    
1345     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1346     wrapper classes; (b) implement a new function in the C++ scanner that is
1347     more efficient than the old way of doing things because it avoids levels of
1348     recursion in the regex matching; (c) add a paragraph to the documentation
1349     for the FullMatch() function.
1350    
1351     6. The escape sequence \n was being treated as whatever was defined as
1352     "newline". Not only was this contrary to the documentation, which states
1353     that \n is character 10 (hex 0A), but it also went horribly wrong when
1354     "newline" was defined as CRLF. This has been fixed.
1355    
1356     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1357     was being set to -1 for the "end of line" case (supposedly a value that no
1358     character can have). Though this value is never used (the check for end of
1359     line is "zero bytes in current character"), it caused compiler complaints.
1360     I've changed it to 0xffffffff.
1361    
1362     8. In pcre_version.c, the version string was being built by a sequence of
1363     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1364     string (as it is for production releases) called a macro with an empty
1365     argument. The C standard says the result of this is undefined. The gcc
1366     compiler treats it as an empty string (which was what was wanted) but it is
1367     reported that Visual C gives an error. The source has been hacked around to
1368     avoid this problem.
1369    
1370     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1371     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1372     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1373     of them did).
1374    
1375     10. Originally, pcretest opened its input and output without "b"; then I was
1376     told that "b" was needed in some environments, so it was added for release
1377     5.0 to both the input and output. (It makes no difference on Unix-like
1378     systems.) Later I was told that it is wrong for the input on Windows. I've
1379     now abstracted the modes into two macros, to make it easier to fiddle with
1380     them, and removed "b" from the input mode under Windows.
1381    
1382     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1383    
1384     12. Added -help and --help to pcretest as an official way of being reminded
1385     of the options.
1386    
1387     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1388     and pcrecpp.cc because they annoy compilers at high warning levels.
1389    
1390     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1391    
1392     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1393     scripts are not C programs :-) and which was not noticed because it works
1394     on Linux.
1395    
1396     16. pcretest is supposed to handle any length of pattern and data line (as one
1397     line or as a continued sequence of lines) by extending its input buffer if
1398     necessary. This feature was broken for very long pattern lines, leading to
1399     a string of junk being passed to pcre_compile() if the pattern was longer
1400     than about 50K.
1401    
1402     17. I have done a major re-factoring of the way pcre_compile() computes the
1403     amount of memory needed for a compiled pattern. Previously, there was code
1404     that made a preliminary scan of the pattern in order to do this. That was
1405     OK when PCRE was new, but as the facilities have expanded, it has become
1406     harder and harder to keep it in step with the real compile phase, and there
1407     have been a number of bugs (see for example, 4 above). I have now found a
1408     cunning way of running the real compile function in a "fake" mode that
1409     enables it to compute how much memory it would need, while actually only
1410     ever using a few hundred bytes of working memory and without too many
1411     tests of the mode. This should make future maintenance and development
1412     easier. A side effect of this work is that the limit of 200 on the nesting
1413     depth of parentheses has been removed (though this was never a serious
1414     limitation, I suspect). However, there is a downside: pcre_compile() now
1415     runs more slowly than before (30% or more, depending on the pattern). I
1416     hope this isn't a big issue. There is no effect on runtime performance.
1417    
1418     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1419     newline (only possible for the last line of a file) and it was a
1420     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1421    
1422     19. Added additional timing features to pcretest. (1) The -tm option now times
1423     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1424     separate command line item, by a number that specifies the number of
1425     repeats to use when timing. The default is 50000; this gives better
1426     precision, but takes uncomfortably long for very large patterns.
1427    
1428     20. Extended pcre_study() to be more clever in cases where a branch of a
1429     subpattern has no definite first character. For example, (a*|b*)[cd] would
1430     previously give no result from pcre_study(). Now it recognizes that the
1431     first character must be a, b, c, or d.
1432    
1433     21. There was an incorrect error "recursive call could loop indefinitely" if
1434     a subpattern (or the entire pattern) that was being tested for matching an
1435     empty string contained only one non-empty item after a nested subpattern.
1436     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1437     incorrectly, because the \d was being skipped in the check.
1438    
1439     22. The pcretest program now has a new pattern option /B and a command line
1440     option -b, which is equivalent to adding /B to every pattern. This causes
1441     it to show the compiled bytecode, without the additional information that
1442     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1443     is the same as /B/I).
1444    
1445     23. A new optimization is now able automatically to treat some sequences such
1446     as a*b as a*+b. More specifically, if something simple (such as a character
1447     or a simple class like \d) has an unlimited quantifier, and is followed by
1448     something that cannot possibly match the quantified thing, the quantifier
1449     is automatically "possessified".
1450    
1451     24. A recursive reference to a subpattern whose number was greater than 39
1452     went wrong under certain circumstances in UTF-8 mode. This bug could also
1453     have affected the operation of pcre_study().
1454    
1455     25. Realized that a little bit of performance could be had by replacing
1456     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1457    
1458     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1459    
1460     27. Possessive quantifiers such as a++ were previously implemented by turning
1461     them into atomic groups such as ($>a+). Now they have their own opcodes,
1462     which improves performance. This includes the automatically created ones
1463     from 23 above.
1464    
1465     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1466     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1467     the first matched character to be a colon. This applied both to named and
1468     numbered groups.
1469    
1470     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1471    
1472     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1473     building PCRE on Windows easier, so I have included it in the distribution.
1474    
1475     31. There is now a check in pcretest against a ridiculously large number being
1476     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1477     loop, the loop is abandoned.
1478    
1479     32. Forward references to subpatterns in conditions such as (?(2)...) where
1480     subpattern 2 is defined later cause pcre_compile() to search forwards in
1481     the pattern for the relevant set of parentheses. This search went wrong
1482     when there were unescaped parentheses in a character class, parentheses
1483     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1484    
1485     33. "Subroutine" calls and backreferences were previously restricted to
1486     referencing subpatterns earlier in the regex. This restriction has now
1487     been removed.
1488    
1489     34. Added a number of extra features that are going to be in Perl 5.10. On the
1490     whole, these are just syntactic alternatives for features that PCRE had
1491     previously implemented using the Python syntax or my own invention. The
1492     other formats are all retained for compatibility.
1493    
1494     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1495     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1496     also .NET compatible.
1497    
1498     (b) A recursion or subroutine call to a named group can now be defined as
1499     (?&name) as well as (?P>name).
1500    
1501     (c) A backreference to a named group can now be defined as \k<name> or
1502     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1503     5.10, are also .NET compatible.
1504    
1505     (d) A conditional reference to a named group can now use the syntax
1506     (?(<name>) or (?('name') as well as (?(name).
1507    
1508     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1509     groups (named and numbered) that are never evaluated inline, but can be
1510     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1511     is always false. There may be only one alternative in such a group.
1512    
1513     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1514     as the simple (?(R). The condition is true only if the most recent
1515     recursion is that of the given number or name. It does not search out
1516     through the entire recursion stack.
1517    
1518     (g) The escape \gN or \g{N} has been added, where N is a positive or
1519     negative number, specifying an absolute or relative reference.
1520    
1521     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1522     some "unreachable code" warnings.
1523    
1524     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1525     things, this adds five new scripts.
1526    
1527     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1528     There were also incompatibilities regarding the handling of \Q..\E inside
1529     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1530     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1531    
1532     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1533     matches an empty string, and forcibly breaks the loop. There were bugs in
1534     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1535     against aaaa the result was just "a" rather than "aaaa", for example. Two
1536     separate and independent bugs (that affected different cases) have been
1537     fixed.
1538    
1539     39. Refactored the code to abolish the use of different opcodes for small
1540     capturing bracket numbers. This is a tidy that I avoided doing when I
1541     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1542     The new approach is not only tidier, it makes it possible to reduce the
1543     memory needed to fix the previous bug (38).
1544    
1545     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1546     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1547     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1548     mode.
1549    
1550     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1551     report.
1552    
1553     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1554     copy construction and assignment in the C++ wrapper.
1555    
1556     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1557     couple of bugs that could have given wrong results in the "--newline=crlf"
1558     case.
1559    
1560     44. Added a number of casts and did some reorganization of signed/unsigned int
1561     variables following suggestions from Dair Grant. Also renamed the variable
1562     "this" as "item" because it is a C++ keyword.
1563    
1564     45. Arranged for dftables to add
1565    
1566     #include "pcre_internal.h"
1567    
1568     to pcre_chartables.c because without it, gcc 4.x may remove the array
1569     definition from the final binary if PCRE is built into a static library and
1570     dead code stripping is activated.
1571    
1572     46. For an unanchored pattern, if a match attempt fails at the start of a
1573     newline sequence, and the newline setting is CRLF or ANY, and the next two
1574     characters are CRLF, advance by two characters instead of one.
1575    
1576    
1577 nigel 91 Version 6.7 04-Jul-06
1578     ---------------------
1579    
1580     1. In order to handle tests when input lines are enormously long, pcretest has
1581     been re-factored so that it automatically extends its buffers when
1582     necessary. The code is crude, but this _is_ just a test program. The
1583     default size has been increased from 32K to 50K.
1584    
1585     2. The code in pcre_study() was using the value of the re argument before
1586     testing it for NULL. (Of course, in any sensible call of the function, it
1587     won't be NULL.)
1588    
1589     3. The memmove() emulation function in pcre_internal.h, which is used on
1590     systems that lack both memmove() and bcopy() - that is, hardly ever -
1591     was missing a "static" storage class specifier.
1592    
1593     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1594     containing an extended class (one that cannot be represented by a bitmap
1595     because it contains high-valued characters or Unicode property items, e.g.
1596     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1597     pattern, but PCRE should not loop if you do not (it no longer does).
1598     [Detail: two cases were found: (a) a repeated subpattern containing an
1599     extended class; (b) a recursive reference to a subpattern that followed a
1600     previous extended class. It wasn't skipping over the extended class
1601     correctly when UTF-8 mode was not set.]
1602    
1603     5. A negated single-character class was not being recognized as fixed-length
1604     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1605     compile error "lookbehind assertion is not fixed length".
1606    
1607     6. The RunPerlTest auxiliary script was showing an unexpected difference
1608     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1609     write a Perl script that can interpret lines of an input file either as
1610     byte characters or as UTF-8, which is what "perltest" was being required to
1611     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1612     can't do is switch easily at run time between having the "use utf8;" pragma
1613     or not. In the end, I fudged it by using the RunPerlTest script to insert
1614     "use utf8;" explicitly for the UTF-8 tests.
1615    
1616     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1617     the end of the subject string, contrary to the documentation and to what
1618     Perl does. This was true of both matching functions. Now it matches only at
1619     the start of the subject and immediately after *internal* newlines.
1620    
1621     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1622     a pointer to an int instead of a pointer to an unsigned long int. This
1623     caused problems on 64-bit systems.
1624    
1625     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1626     instance of the 'standard' template library not being so standard".
1627    
1628     10. There was no check on the number of named subpatterns nor the maximum
1629     length of a subpattern name. The product of these values is used to compute
1630     the size of the memory block for a compiled pattern. By supplying a very
1631     long subpattern name and a large number of named subpatterns, the size
1632     computation could be caused to overflow. This is now prevented by limiting
1633     the length of names to 32 characters, and the number of named subpatterns
1634     to 10,000.
1635    
1636     11. Subpatterns that are repeated with specific counts have to be replicated in
1637     the compiled pattern. The size of memory for this was computed from the
1638     length of the subpattern and the repeat count. The latter is limited to
1639     65535, but there was no limit on the former, meaning that integer overflow
1640     could in principle occur. The compiled length of a repeated subpattern is
1641     now limited to 30,000 bytes in order to prevent this.
1642    
1643     12. Added the optional facility to have named substrings with the same name.
1644    
1645     13. Added the ability to use a named substring as a condition, using the
1646     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1647     are numbers (not recommended). Forward references are permitted.
1648    
1649     14. Added forward references in named backreferences (if you see what I mean).
1650    
1651     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1652     pattern could run off the end of the subject. For example, the pattern
1653     "(?s)(.{1,5})"8 did this with the subject "ab".
1654    
1655     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1656     PCRE_CASELESS was set when matching characters that were quantified with ?
1657     or *.
1658    
1659     17. A character class other than a single negated character that had a minimum
1660     but no maximum quantifier - for example [ab]{6,} - was not handled
1661     correctly by pce_dfa_exec(). It would match only one character.
1662    
1663     18. A valid (though odd) pattern that looked like a POSIX character
1664     class but used an invalid character after [ (for example [[,abc,]]) caused
1665     pcre_compile() to give the error "Failed: internal error: code overflow" or
1666     in some cases to crash with a glibc free() error. This could even happen if
1667     the pattern terminated after [[ but there just happened to be a sequence of
1668     letters, a binary zero, and a closing ] in the memory that followed.
1669    
1670     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1671     over the years. Originally (before any Unicode support), just the bottom 8
1672     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1673     output from "man perlunicode" includes this:
1674    
1675     The regular expression compiler produces polymorphic opcodes. That
1676     is, the pattern adapts to the data and automatically switches to
1677     the Unicode character scheme when presented with Unicode data--or
1678     instead uses a traditional byte scheme when presented with byte
1679     data.
1680    
1681     Sadly, a wide octal escape does not cause a switch, and in a string with
1682     no other multibyte characters, these octal escapes are treated as before.
1683     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1684     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1685     Unicode string.
1686    
1687     I have not perpetrated such confusion in PCRE. Up till now, it took just
1688     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1689     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1690     translate to the appropriate multibyte character.
1691    
1692     29. Applied some refactoring to reduce the number of warnings from Microsoft
1693     and Borland compilers. This has included removing the fudge introduced
1694     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1695     a warning about an unused variable.
1696    
1697     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1698     characters since release 4.0, because Perl (from release 5.004) does not.
1699     [Or at least, is documented not to: some releases seem to be in conflict
1700     with the documentation.] However, when a pattern was studied with
1701     pcre_study() and all its branches started with \s, PCRE still included VT
1702     as a possible starting character. Of course, this did no harm; it just
1703     caused an unnecessary match attempt.
1704    
1705     22. Removed a now-redundant internal flag bit that recorded the fact that case
1706     dependency changed within the pattern. This was once needed for "required
1707     byte" processing, but is no longer used. This recovers a now-scarce options
1708     bit. Also moved the least significant internal flag bit to the most-
1709     significant bit of the word, which was not previously used (hangover from
1710     the days when it was an int rather than a uint) to free up another bit for
1711     the future.
1712    
1713     23. Added support for CRLF line endings as well as CR and LF. As well as the
1714     default being selectable at build time, it can now be changed at runtime
1715     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1716     specify that it is scanning data with non-default line endings.
1717    
1718     24. Changed the definition of CXXLINK to make it agree with the definition of
1719     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1720    
1721     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1722     recursions. This makes a big different to stack usage for some patterns.
1723    
1724     26. If a subpattern containing a named recursion or subroutine reference such
1725     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1726     the space required for the compiled pattern went wrong and gave too small a
1727     value. Depending on the environment, this could lead to "Failed: internal
1728     error: code overflow at offset 49" or "glibc detected double free or
1729     corruption" errors.
1730    
1731     27. Applied patches from Google (a) to support the new newline modes and (b) to
1732     advance over multibyte UTF-8 characters in GlobalReplace.
1733    
1734     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1735     difference for some implementation of PCRE in some Windows version.
1736    
1737     29. Added some extra testing facilities to pcretest:
1738    
1739     \q<number> in a data line sets the "match limit" value
1740     \Q<number> in a data line sets the "match recursion limt" value
1741     -S <number> sets the stack size, where <number> is in megabytes
1742    
1743     The -S option isn't available for Windows.
1744    
1745    
1746 nigel 89 Version 6.6 06-Feb-06
1747     ---------------------
1748    
1749     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1750     in pcreposix.h. I have copied the definition from pcre.h.
1751    
1752     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1753     because pcre.h is no longer a built file.
1754    
1755     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1756     not normally included in the compiled code.
1757    
1758    
1759 nigel 87 Version 6.5 01-Feb-06
1760     ---------------------
1761    
1762     1. When using the partial match feature with pcre_dfa_exec(), it was not
1763     anchoring the second and subsequent partial matches at the new starting
1764     point. This could lead to incorrect results. For example, with the pattern
1765     /1234/, partially matching against "123" and then "a4" gave a match.
1766    
1767     2. Changes to pcregrep:
1768    
1769     (a) All non-match returns from pcre_exec() were being treated as failures
1770     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1771     error message is output. Some extra information is given for the
1772     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1773     probably the only errors that are likely to be caused by users (by
1774     specifying a regex that has nested indefinite repeats, for instance).
1775     If there are more than 20 of these errors, pcregrep is abandoned.
1776    
1777     (b) A binary zero was treated as data while matching, but terminated the
1778     output line if it was written out. This has been fixed: binary zeroes
1779     are now no different to any other data bytes.
1780    
1781     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1782     used to set a locale for matching. The --locale=xxxx long option has
1783     been added (no short equivalent) to specify a locale explicitly on the
1784     pcregrep command, overriding the environment variables.
1785    
1786     (d) When -B was used with -n, some line numbers in the output were one less
1787     than they should have been.
1788    
1789     (e) Added the -o (--only-matching) option.
1790    
1791     (f) If -A or -C was used with -c (count only), some lines of context were
1792     accidentally printed for the final match.
1793    
1794     (g) Added the -H (--with-filename) option.
1795    
1796     (h) The combination of options -rh failed to suppress file names for files
1797     that were found from directory arguments.
1798    
1799     (i) Added the -D (--devices) and -d (--directories) options.
1800    
1801     (j) Added the -F (--fixed-strings) option.
1802    
1803     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1804    
1805     (l) Added the --colo(u)r option.
1806    
1807     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1808     is not present by default.
1809    
1810     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1811     items such as (?R) or (?1), when the recursion could match a number of
1812     alternatives. If it matched one of the alternatives, but subsequently,
1813     outside the recursion, there was a failure, the code tried to back up into
1814     the recursion. However, because of the way PCRE is implemented, this is not
1815     possible, and the result was an incorrect result from the match.
1816    
1817     In order to prevent this happening, the specification of recursion has
1818     been changed so that all such subpatterns are automatically treated as
1819     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1820    
1821     4. I had overlooked the fact that, in some locales, there are characters for
1822     which isalpha() is true but neither isupper() nor islower() are true. In
1823     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1824     and ordfeminine) are like this. This affected the treatment of \w and \W
1825     when they appeared in character classes, but not when they appeared outside
1826     a character class. The bit map for "word" characters is now created
1827     separately from the results of isalnum() instead of just taking it from the
1828     upper, lower, and digit maps. (Plus the underscore character, of course.)
1829    
1830     5. The above bug also affected the handling of POSIX character classes such as
1831     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1832     permanent tables. Instead, the bit maps for such a class were previously
1833     created as the appropriate unions of the upper, lower, and digit bitmaps.
1834     Now they are created by subtraction from the [[:word:]] class, which has
1835     its own bitmap.
1836    
1837     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1838     It is created by subtracting the vertical space characters (\x09, \x0a,
1839     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1840     subtraction was done in the overall bitmap for a character class, meaning
1841     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1842     be recognized. This bug has been fixed.
1843    
1844     7. Patches from the folks at Google:
1845    
1846     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1847     real life, but is still worth protecting against".
1848    
1849     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1850     regular expressions".
1851    
1852     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1853     have it.
1854    
1855     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1856     "configure" and the latter not, in order to fix a problem somebody had
1857     with compiling the Arg class on HP-UX.
1858    
1859     (e) Improve the error-handling of the C++ wrapper a little bit.
1860    
1861     (f) New tests for checking recursion limiting.
1862    
1863     8. The pcre_memmove() function, which is used only if the environment does not
1864     have a standard memmove() function (and is therefore rarely compiled),
1865     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1866     returning a result (though PCRE never actually uses the result).
1867    
1868     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1869     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1870     returned instead of calling malloc() with an overflowing number that would
1871     most likely cause subsequent chaos.
1872    
1873     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1874    
1875     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1876     with this option is matched, the nmatch and pmatch options of regexec() are
1877     ignored.
1878    
1879     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1880     provided in case anyone wants to the the POSIX interface with UTF-8
1881     strings.
1882    
1883     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1884     C++ linking (needed for some HP-UX environments).
1885    
1886     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1887     (unused parameter) and in the pcre_printint() function (omitted "default"
1888     switch label when the default is to do nothing).
1889    
1890     15. Added some code to make it possible, when PCRE is compiled as a C++
1891     library, to replace subject pointers for pcre_exec() with a smart pointer
1892     class, thus making it possible to process discontinuous strings.
1893    
1894     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1895     much the same function. They were added by different people who were trying
1896     to make PCRE easy to compile on non-Unix systems. It has been suggested
1897     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1898     for compiling on Windows systems. I have therefore replaced it with
1899     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1900     defaults to "extern" for C or "extern C" for C++, which works fine on
1901     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1902     SCOPE with something explicit in config.h. In addition:
1903    
1904     (a) pcreposix.h still had just "extern" instead of either of these macros;
1905     I have replaced it with PCRE_DATA_SCOPE.
1906    
1907     (b) Functions such as _pcre_xclass(), which are internal to the library,
1908     but external in the C sense, all had PCRE_EXPORT in their definitions.
1909     This is apparently wrong for the Windows case, so I have removed it.
1910     (It makes no difference on Unix-like systems.)
1911    
1912     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1913     of recursive calls to match(). This is different to MATCH_LIMIT because
1914     that limits the total number of calls to match(), not all of which increase
1915     the depth of recursion. Limiting the recursion depth limits the amount of
1916     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1917     when PCRE is compiled, and changed at run time. A patch from Google adds
1918     this functionality to the C++ interface.
1919    
1920     18. Changes to the handling of Unicode character properties:
1921    
1922     (a) Updated the table to Unicode 4.1.0.
1923    
1924     (b) Recognize characters that are not in the table as "Cn" (undefined).
1925    
1926     (c) I revised the way the table is implemented to a much improved format
1927     which includes recognition of ranges. It now supports the ranges that
1928     are defined in UnicodeData.txt, and it also amalgamates other
1929     characters into ranges. This has reduced the number of entries in the
1930     table from around 16,000 to around 3,000, thus reducing its size
1931     considerably. I realized I did not need to use a tree structure after
1932     all - a binary chop search is just as efficient. Having reduced the
1933     number of entries, I extended their size from 6 bytes to 8 bytes to
1934     allow for more data.
1935    
1936     (d) Added support for Unicode script names via properties such as \p{Han}.
1937    
1938     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1939     matching that character.
1940    
1941     20. When matching a repeated Unicode property with a minimum greater than zero,
1942     (for example \pL{2,}), PCRE could look past the end of the subject if it
1943     reached it while seeking the minimum number of characters. This could
1944     happen only if some of the characters were more than one byte long, because
1945     there is a check for at least the minimum number of bytes.
1946    
1947     21. Refactored the implementation of \p and \P so as to be more general, to
1948     allow for more different types of property in future. This has changed the
1949     compiled form incompatibly. Anybody with saved compiled patterns that use
1950     \p or \P will have to recompile them.
1951    
1952     22. Added "Any" and "L&" to the supported property types.
1953    
1954     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1955     but give a compile time error if the value is greater than 0xff.
1956    
1957     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1958     accidentally not being installed or uninstalled.
1959    
1960     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1961     made were to insert the current release number. This seemed silly, because
1962     it made things harder for people building PCRE on systems that don't run
1963     "configure". I have turned pcre.h into a distributed file, no longer built
1964     by "configure", with the version identification directly included. There is
1965     no longer a pcre.h.in file.
1966    
1967     However, this change necessitated a change to the pcre-config script as
1968     well. It is built from pcre-config.in, and one of the substitutions was the
1969     release number. I have updated configure.ac so that ./configure now finds
1970     the release number by grepping pcre.h.
1971    
1972     26. Added the ability to run the tests under valgrind.
1973    
1974    
1975 nigel 85 Version 6.4 05-Sep-05
1976     ---------------------
1977    
1978     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1979     "--" to be printed when multiple files were scanned, even when none of the
1980     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1981     consider it to be a bug, and have restored the previous behaviour.
1982    
1983     2. A couple of code tidies to get rid of compiler warnings.
1984    
1985     3. The pcretest program used to cheat by referring to symbols in the library
1986     whose names begin with _pcre_. These are internal symbols that are not
1987     really supposed to be visible externally, and in some environments it is
1988     possible to suppress them. The cheating is now confined to including
1989     certain files from the library's source, which is a bit cleaner.
1990    
1991     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1992     file's purpose clearer.
1993    
1994     5. Reorganized pcre_ucp_findchar().
1995    
1996    
1997 nigel 83 Version 6.3 15-Aug-05
1998     ---------------------
1999    
2000     1. The file libpcre.pc.in did not have general read permission in the tarball.
2001    
2002     2. There were some problems when building without C++ support:
2003    
2004     (a) If C++ support was not built, "make install" and "make test" still
2005     tried to test it.
2006    
2007     (b) There were problems when the value of CXX was explicitly set. Some
2008     changes have been made to try to fix these, and ...
2009    
2010     (c) --disable-cpp can now be used to explicitly disable C++ support.
2011    
2012     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2013     backslash in a target when C++ was disabled. This confuses some
2014     versions of "make", apparently. Using an intermediate variable solves
2015     this. (Same for CPP_LOBJ.)
2016    
2017     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2018     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2019     necessary on certain architectures.
2020    
2021     4. Added a setting of -export-symbols-regex to the link command to remove
2022     those symbols that are exported in the C sense, but actually are local
2023     within the library, and not documented. Their names all begin with
2024     "_pcre_". This is not a perfect job, because (a) we have to except some
2025     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2026     available (and never for static libraries). I have made a note to try to
2027     find a way round (a) in the future.
2028    
2029    
2030 nigel 81 Version 6.2 01-Aug-05
2031     ---------------------
2032    
2033     1. There was no test for integer overflow of quantifier values. A construction
2034     such as {1111111111111111} would give undefined results. What is worse, if
2035     a minimum quantifier for a parenthesized subpattern overflowed and became
2036     negative, the calculation of the memory size went wrong. This could have
2037     led to memory overwriting.
2038    
2039     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2040    
2041     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2042     operating environments where this matters.
2043    
2044     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2045     PCRE options from within the C++ wrapper.
2046    
2047     5. Named capturing subpatterns were not being correctly counted when a pattern
2048     was compiled. This caused two problems: (a) If there were more than 100
2049     such subpatterns, the calculation of the memory needed for the whole
2050     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2051     back references of the form \12, where the number was greater than 9, were
2052     not recognized as back references, even though there were sufficient
2053     previous subpatterns.
2054    
2055     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2056     versions of gcc, e.g. 2.95.4.
2057    
2058    
2059 nigel 79 Version 6.1 21-Jun-05
2060     ---------------------
2061    
2062     1. There was one reference to the variable "posix" in pcretest.c that was not
2063     surrounded by "#if !defined NOPOSIX".
2064    
2065     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2066     the cross-check on the old pcre_info() function, for the benefit of the
2067     cut-down version of PCRE that is currently imported into Exim.
2068    
2069     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2070     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2071     patterns that start (?i) but I don't think that matters. The use of (?i) is
2072     just an example; this all applies to the other options as well.
2073    
2074     4. Since libtool seems to echo the compile commands it is issuing, the output
2075     from "make" can be reduced a bit by putting "@" in front of each libtool
2076     compile command.
2077    
2078     5. Patch from the folks at Google for configure.in to be a bit more thorough
2079     in checking for a suitable C++ installation before trying to compile the
2080     C++ stuff. This should fix a reported problem when a compiler was present,
2081     but no suitable headers.
2082    
2083     6. The man pages all had just "PCRE" as their title. I have changed them to
2084     be the relevant file name. I have also arranged that these names are
2085     retained in the file doc/pcre.txt, which is a concatenation in text format
2086     of all the man pages except the little individual ones for each function.
2087    
2088     7. The NON-UNIX-USE file had not been updated for the different set of source
2089     files that come with release 6. I also added a few comments about the C++
2090     wrapper.
2091    
2092    
2093 nigel 77 Version 6.0 07-Jun-05
2094     ---------------------
2095    
2096     1. Some minor internal re-organization to help with my DFA experiments.
2097    
2098     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2099     didn't matter for the library itself when fully configured, but did matter
2100     when compiling without UCP support, or within Exim, where the ucp files are
2101     not imported.
2102    
2103     3. Refactoring of the library code to split up the various functions into
2104     different source modules. The addition of the new DFA matching code (see
2105     below) to a single monolithic source would have made it really too
2106     unwieldy, quite apart from causing all the code to be include in a
2107     statically linked application, when only some functions are used. This is
2108     relevant even without the DFA addition now that patterns can be compiled in
2109     one application and matched in another.
2110    
2111     The downside of splitting up is that there have to be some external
2112     functions and data tables that are used internally in different modules of
2113     the library but which are not part of the API. These have all had their
2114     names changed to start with "_pcre_" so that they are unlikely to clash
2115     with other external names.
2116    
2117     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2118     a different (DFA) algorithm. Although it is slower than the original
2119     function, it does have some advantages for certain types of matching
2120     problem.
2121    
2122     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2123     including restarting after a partial match.
2124    
2125     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2126     defined when compiling for Windows was sent to me. I have put it into the
2127     code, though I have no means of testing or verifying it.
2128    
2129     7. Added the pcre_refcount() auxiliary function.
2130    
2131     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2132     match before or at the first newline in the subject string. In pcretest,
2133     the /f option on a pattern can be used to set this.
2134    
2135     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2136     would behave wrongly. This has been present in PCRE since release 4.0.
2137    
2138     10. A number of changes to the pcregrep command:
2139    
2140     (a) Refactored how -x works; insert ^(...)$ instead of setting
2141     PCRE_ANCHORED and checking the length, in preparation for adding
2142     something similar for -w.
2143    
2144     (b) Added the -w (match as a word) option.
2145    
2146     (c) Refactored the way lines are read and buffered so as to have more
2147     than one at a time available.
2148    
2149     (d) Implemented a pcregrep test script.
2150    
2151     (e) Added the -M (multiline match) option. This allows patterns to match
2152     over several lines of the subject. The buffering ensures that at least
2153     8K, or the rest of the document (whichever is the shorter) is available
2154     for matching (and similarly the previous 8K for lookbehind assertions).
2155    
2156     (f) Changed the --help output so that it now says
2157    
2158     -w, --word-regex(p)
2159    
2160     instead of two lines, one with "regex" and the other with "regexp"
2161     because that confused at least one person since the short forms are the
2162     same. (This required a bit of code, as the output is generated
2163     automatically from a table. It wasn't just a text change.)
2164    
2165     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2166     option but starts with a hyphen. Could be a pattern or a path name
2167     starting with a hyphen, for instance.
2168    
2169     (h) "-" can be given as a file name to represent stdin.
2170    
2171     (i) When file names are being printed, "(standard input)" is used for
2172     the standard input, for compatibility with GNU grep. Previously
2173     "<stdin>" was used.
2174    
2175     (j) The option --label=xxx can be used to supply a name to be used for
2176     stdin when file names are being printed. There is no short form.
2177    
2178     (k) Re-factored the options decoding logic because we are going to add
2179     two more options that take data. Such options can now be given in four
2180     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2181    
2182     (l) Added the -A, -B, and -C options for requesting that lines of context
2183     around matches be printed.
2184    
2185     (m) Added the -L option to print the names of files that do not contain
2186     any matching lines, that is, the complement of -l.
2187    
2188     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2189     continue to scan other files.
2190    
2191     (o) The -s option was incorrectly implemented. For compatibility with other
2192     greps, it now suppresses the error message for a non-existent or non-
2193     accessible file (but not the return code). There is a new option called
2194     -q that suppresses the output of matching lines, which was what -s was
2195     previously doing.
2196    
2197     (p) Added --include and --exclude options to specify files for inclusion
2198     and exclusion when recursing.
2199    
2200     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2201     Hopefully, it now does.
2202    
2203     12. Missing cast in pcre_study().
2204    
2205     13. Added an "uninstall" target to the makefile.
2206    
2207     14. Replaced "extern" in the function prototypes in Makefile.in with
2208     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2209     world, but is set differently for Windows.
2210    
2211     15. Added a second compiling function called pcre_compile2(). The only
2212     difference is that it has an extra argument, which is a pointer to an
2213     integer error code. When there is a compile-time failure, this is set
2214     non-zero, in addition to the error test pointer being set to point to an
2215     error message. The new argument may be NULL if no error number is required
2216     (but then you may as well call pcre_compile(), which is now just a
2217     wrapper). This facility is provided because some applications need a
2218     numeric error indication, but it has also enabled me to tidy up the way
2219     compile-time errors are handled in the POSIX wrapper.
2220    
2221     16. Added VPATH=.libs to the makefile; this should help when building with one
2222     prefix path and installing with another. (Or so I'm told by someone who
2223     knows more about this stuff than I do.)
2224    
2225     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2226     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2227     match everything, including newlines. This is not POSIX-compatible, but
2228     somebody wanted the feature. From pcretest it can be activated by using
2229     both the P and the s flags.
2230    
2231     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2232    
2233     19. libpcre.pc was being incorrectly installed as executable.
2234    
2235     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2236     it now also looks for '\r' so that it will work unmodified on Windows.
2237    
2238     21. Added Google's contributed C++ wrapper to the distribution.
2239    
2240     22. Added some untidy missing memory free() calls in pcretest, to keep
2241     Electric Fence happy when testing.
2242    
2243    
2244    
2245 nigel 75 Version 5.0 13-Sep-04
2246     ---------------------
2247    
2248     1. Internal change: literal characters are no longer packed up into items
2249     containing multiple characters in a single byte-string. Each character
2250     is now matched using a separate opcode. However, there may be more than one
2251     byte in the character in UTF-8 mode.
2252    
2253     2. The pcre_callout_block structure has two new fields: pattern_position and
2254     next_item_length. These contain the offset in the pattern to the next match
2255     item, and its length, respectively.
2256    
2257     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2258     insertion of callouts before each pattern item. Added the /C option to
2259     pcretest to make use of this.
2260    
2261     4. On the advice of a Windows user, the lines
2262    
2263     #if defined(_WIN32) || defined(WIN32)
2264     _setmode( _fileno( stdout ), 0x8000 );
2265     #endif /* defined(_WIN32) || defined(WIN32) */
2266    
2267     have been added to the source of pcretest. This apparently does useful
2268     magic in relation to line terminators.
2269    
2270     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2271     for the benefit of those environments where the "b" makes a difference.
2272    
2273     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2274     to know about it. I have put a hack into configure.in that adds in code
2275     to set GCC=yes if CC=icc. This seems to end up at a point in the
2276     generated configure script that is early enough to affect the setting of
2277     compiler options, which is what is needed, but I have no means of testing
2278     whether it really works. (The user who reported this had patched the
2279     generated configure script, which of course I cannot do.)
2280    
2281     LATER: After change 22 below (new libtool files), the configure script
2282     seems to know about icc (and also ecc). Therefore, I have commented out
2283     this hack in configure.in.
2284    
2285     7. Added support for pkg-config (2 patches were sent in).
2286    
2287     8. Negated POSIX character classes that used a combination of internal tables
2288     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2289     [[:^ascii]]. Typically, they would match almost any characters. The other
2290     POSIX classes were not broken in this way.
2291    
2292     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2293     to find the match, as PCRE was deluded into thinking that the match had to
2294     start at the start point or following a newline. The same bug applied to
2295     patterns with negative forward assertions or any backward assertions
2296     preceding ".*" at the start, unless the pattern required a fixed first
2297     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2298    
2299     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2300     starting at the last subject character, bytes beyond the end of the subject
2301     string were read.
2302    
2303     11. Renamed the variable "class" as "classbits" to make life easier for C++
2304     users. (Previously there was a macro definition, but it apparently wasn't
2305     enough.)
2306    
2307     12. Added the new field "tables" to the extra data so that tables can be passed
2308     in at exec time, or the internal tables can be re-selected. This allows
2309     a compiled regex to be saved and re-used at a later time by a different
2310     program that might have everything at different addresses.
2311    
2312     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2313     -R library as well as a -L library.
2314    
2315     14. The debugging options of pcretest (-d on the command line or D on a
2316     pattern) showed incorrect output for anything following an extended class
2317     that contained multibyte characters and which was followed by a quantifier.
2318    
2319     15. Added optional support for general category Unicode character properties
2320     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2321     support. It adds about 90K to the size of the library. The meanings of the
2322     inbuilt class escapes such as \d and \s have NOT been changed.
2323    
2324     16. Updated pcredemo.c to include calls to free() to release the memory for the
2325     compiled pattern.
2326    
2327     17. The generated file chartables.c was being created in the source directory
2328     instead of in the building directory. This caused the build to fail if the
2329     source directory was different from the building directory, and was
2330     read-only.
2331    
2332     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2333     file. No doubt somebody will tell me if they don't make sense... Also added
2334     Dan Mooney's comments about building on OpenVMS.
2335    
2336     19. Added support for partial matching via the PCRE_PARTIAL option for
2337     pcre_exec() and the \P data escape in pcretest.
2338    
2339     20. Extended pcretest with 3 new pattern features:
2340    
2341     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2342     write the compiled pattern to the file whose name is "rest-of-line".
2343     This is a straight binary dump of the data, with the saved pointer to
2344     the character tables forced to be NULL. The study data, if any, is
2345     written too. After writing, pcretest reads a new pattern.
2346    
2347     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2348     compiled pattern from the given file. There must not be any
2349     occurrences of "<" in the file name (pretty unlikely); if there are,
2350     pcretest will instead treat the initial "<" as a pattern delimiter.
2351     After reading in the pattern, pcretest goes on to read data lines as
2352     usual.
2353    
2354     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2355     and 16-bit fields in a compiled pattern, to simulate a pattern that
2356     was compiled on a host of opposite endianness.
2357    
2358     21. The pcre-exec() function can now cope with patterns that were compiled on
2359     hosts of opposite endianness, with this restriction:
2360    
2361     As for any compiled expression that is saved and used later, the tables
2362     pointer field cannot be preserved; the extra_data field in the arguments
2363     to pcre_exec() should be used to pass in a tables address if a value
2364     other than the default internal tables were used at compile time.
2365    
2366     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2367     now diagnosed as an error. Previously, most of the time, a negative number
2368     would have been treated as zero, but if in addition "ovector" was passed as
2369     NULL, a crash could occur.
2370    
2371     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2372     new versions from the libtool 1.5 distribution (the last one is a copy of
2373     a file called libtool.m4). This seems to have fixed the need to patch
2374     "configure" to support Darwin 1.3 (which I used to do). However, I still
2375     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2376     workstation).
2377    
2378     24. Changed the PCRE licence to be the more standard "BSD" licence.
2379    
2380    
2381 nigel 73 Version 4.5 01-Dec-03
2382     ---------------------
2383    
2384     1. There has been some re-arrangement of the code for the match() function so
2385     that it can be compiled in a version that does not call itself recursively.
2386     Instead, it keeps those local variables that need separate instances for
2387     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2388     needs to "recurse". Keeping track of where control must go is done by means
2389     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2390     hide most of the details from the main code, and operates only if
2391     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2392     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2393     operating.
2394    
2395     To make it easier for callers to provide specially tailored get/free
2396     functions for this usage, two new functions, pcre_stack_malloc, and
2397     pcre_stack_free, are used. They are always called in strict stacking order,
2398     and the size of block requested is always the same.
2399    
2400     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2401     PCRE has been compiled to use the stack or the heap for recursion. The
2402     -C option of pcretest uses this to show which version is compiled.
2403    
2404     A new data escape \S, is added to pcretest; it causes the amounts of store
2405     obtained and freed by both kinds of malloc/free at match time to be added
2406     to the output.
2407    
2408     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2409     what's available on my current Linux desktop machine.
2410    
2411     3. When matching a UTF-8 string, the test for a valid string at the start has
2412     been extended. If start_offset is not zero, PCRE now checks that it points
2413     to a byte that is the start of a UTF-8 character. If not, it returns
2414     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2415     this is necessary because there may be backward assertions in the pattern.
2416     When matching the same subject several times, it may save resources to use
2417     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2418    
2419     4. The code for checking the validity of UTF-8 strings has been tightened so
2420     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2421     containing "overlong sequences".
2422    
2423     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2424     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2425     should have been "&", but it just so happened that all the cases this let
2426     through by mistake were picked up later in the function.
2427    
2428     6. I had used a variable called "isblank" - this is a C99 function, causing
2429     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2430    
2431     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2432     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2433     so the version is shown; (c) stop "make test" echoing "./RunTest".
2434    
2435     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2436    
2437     9. The prototype for memmove() for systems that don't have it was using
2438     size_t, but the inclusion of the header that defines size_t was later. I've
2439     moved the #includes for the C headers earlier to avoid this.
2440    
2441     10. Added some adjustments to the code to make it easier to compiler on certain
2442     special systems:
2443    
2444     (a) Some "const" qualifiers were missing.
2445     (b) Added the macro EXPORT before all exported functions; by default this
2446     is defined to be empty.
2447     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2448     that it reads its output file name as an argument instead of writing
2449     to the standard output and assuming this can be redirected.
2450    
2451     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2452     class containing characters with values greater than 255, PCRE compilation
2453     went into a loop.
2454    
2455     12. A recursive reference to a subpattern that was within another subpattern
2456     that had a minimum quantifier of zero caused PCRE to crash. For example,
2457     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2458     recursion. If the recursively-called subpattern itself had a zero repeat,
2459     that was OK.
2460    
2461     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2462     buffer into which it was copied (for escape processing) was still set at
2463     1024, so long lines caused crashes.
2464    
2465     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2466     "internal error: code overflow...". This applied to any character class
2467     that was followed by a possessive quantifier.
2468    
2469     15. Modified the Makefile to add libpcre.la as a prerequisite for
2470     libpcreposix.la because I was told this is needed for a parallel build to
2471     work.
2472    
2473     16. If a pattern that contained .* following optional items at the start was
2474     studied, the wrong optimizing data was generated, leading to matching
2475     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2476     matching string must start with a or b or c. The correct conclusion for
2477     this pattern is that a match can start with any character.
2478    
2479    
2480 nigel 71 Version 4.4 13-Aug-03
2481     ---------------------
2482    
2483     1. In UTF-8 mode, a character class containing characters with values between
2484     127 and 255 was not handled correctly if the compiled pattern was studied.
2485     In fixing this, I have also improved the studying algorithm for such
2486     classes (slightly).
2487    
2488     2. Three internal functions had redundant arguments passed to them. Removal
2489     might give a very teeny performance improvement.
2490    
2491     3. Documentation bug: the value of the capture_top field in a callout is *one
2492     more than* the number of the hightest numbered captured substring.
2493    
2494     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2495     in incorrectly linking with a previously installed version. They now link
2496     explicitly with libpcre.la.
2497    
2498     5. configure.in no longer needs to recognize Cygwin specially.
2499    
2500     6. A problem in pcre.in for Windows platforms is fixed.
2501    
2502     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2503     pcretest, it used to include the size of the study block as part of its
2504     output. Unfortunately, the structure contains a field that has a different
2505     size on different hardware architectures. This meant that the tests that
2506     showed this size failed. As the block is currently always of a fixed size,
2507     this information isn't actually particularly useful in pcretest output, so
2508     I have just removed it.
2509    
2510     8. Three pre-processor statements accidentally did not start in column 1.
2511     Sadly, there are *still* compilers around that complain, even though
2512     standard C has not required this for well over a decade. Sigh.
2513    
2514     9. In pcretest, the code for checking callouts passed small integers in the
2515     callout_data field, which is a void * field. However, some picky compilers
2516     complained about the casts involved for this on 64-bit systems. Now
2517     pcretest passes the address of the small integer instead, which should get
2518     rid of the warnings.
2519    
2520     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2521     both compile and run time, and gives an error if an invalid UTF-8 sequence
2522     is found. There is a option for disabling this check in cases where the
2523     string is known to be correct and/or the maximum performance is wanted.
2524    
2525     11. In response to a bug report, I changed one line in Makefile.in from
2526    
2527     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2528     to
2529     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2530    
2531     to look similar to other lines, but I have no way of telling whether this
2532     is the right thing to do, as I do not use Windows. No doubt I'll get told
2533     if it's wrong...
2534    
2535    
2536 nigel 69 Version 4.3 21-May-03
2537     ---------------------
2538    
2539     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2540     Makefile.
2541    
2542     2. Some refactoring to improve the quality of the code:
2543    
2544     (i) The utf8_table... variables are now declared "const".
2545    
2546     (ii) The code for \cx, which used the "case flipping" table to upper case
2547     lower case letters, now just substracts 32. This is ASCII-specific,
2548     but the whole concept of \cx is ASCII-specific, so it seems
2549     reasonable.
2550    
2551     (iii) PCRE was using its character types table to recognize decimal and
2552     hexadecimal digits in the pattern. This is silly, because it handles
2553     only 0-9, a-f, and A-F, but the character types table is locale-
2554     specific, which means strange things might happen. A private
2555     table is now used for this - though it costs 256 bytes, a table is
2556     much faster than multiple explicit tests. Of course, the standard
2557     character types table is still used for matching digits in subject
2558     strings against \d.
2559    
2560     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2561     ending in _t are). So I've renamed it as ESC_tee.
2562    
2563     3. The first argument for regexec() in the POSIX wrapper should have been
2564     defined as "const".
2565    
2566     4. Changed pcretest to use malloc() for its buffers so that they can be
2567     Electric Fenced for debugging.
2568    
2569     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2570     to read one or more bytes before the start of the subject string. Often this
2571     had no effect on PCRE's behaviour, but in some circumstances it could
2572     provoke a segmentation fault.
2573    
2574     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2575     to try to read one or more bytes before the start of the subject string.
2576    
2577     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2578     UTF-8 support could misbehave in various ways if the subject string
2579     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2580     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2581     back over UTF-8 characters.)
2582    
2583    
2584 nigel 67 Version 4.2 14-Apr-03
2585     ---------------------
2586    
2587     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2588    
2589     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2590     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2591     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2592     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2593     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2594     and BUILD_EXEEXT
2595     Note: automatic setting of the BUILD variables is not yet working
2596     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2597     compile-time but not at link-time
2598     [LINK]: use for linking executables only
2599     make different versions for Windows and non-Windows
2600     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2601     libraries
2602     [LINK_FOR_BUILD]: new variable
2603     [OBJEXT]: use throughout
2604     [EXEEXT]: use throughout
2605     <winshared>: new target
2606     <wininstall>: new target
2607     <dftables.o>: use native compiler
2608     <dftables>: use native linker
2609     <install>: handle Windows platform correctly
2610     <clean>: ditto
2611     <check>: ditto
2612     copy DLL to top builddir before testing
2613    
2614     As part of these changes, -no-undefined was removed again. This was reported
2615     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2616     in any case.
2617    
2618     3. Some tidies to get rid of compiler warnings:
2619    
2620     . In the match_data structure, match_limit was an unsigned long int, whereas
2621     match_call_count was an int. I've made them both unsigned long ints.
2622    
2623     . In pcretest the fact that a const uschar * doesn't automatically cast to
2624     a void * provoked a warning.
2625    
2626     . Turning on some more compiler warnings threw up some "shadow" variables
2627     and a few more missing casts.
2628    
2629     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2630     option, a class that contained a single character with a value between 128
2631     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2632    
2633     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2634     option, a class that contained several characters, but with at least one
2635     whose value was between 128 and 255 caused PCRE to crash.
2636    
2637    
2638 nigel 65 Version 4.1 12-Mar-03
2639     ---------------------
2640 nigel 63
2641 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2642     needed, and a string in dftables.c that was longer than standard compilers are
2643     required to support.
2644    
2645     2. Compiling with Sun's compiler found a few more places where the code could
2646     be tidied up in order to avoid warnings.
2647    
2648     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2649     first of these names is deprecated in the latest Autoconf in favour of the name
2650     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2651     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2652     analogy I have changed it to CFLAGS_FOR_BUILD.
2653    
2654     4. Added -no-undefined to the linking command in the Makefile, because this is
2655     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2656     linking step for the pcreposix library.
2657    
2658     5. PCRE was failing to diagnose the case of two named groups with the same
2659     name.
2660    
2661     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2662     literal character that is needed in the subject for a match, and scans along to
2663     ensure that it is present before embarking on the full matching process. This
2664     saves time in cases of nested unlimited repeats that are never going to match.
2665     Problem: the scan can take a lot of time if the subject is very long (e.g.
2666     megabytes), thus penalizing straightforward matches. It is now done only if the
2667     amount of subject to be scanned is less than 1000 bytes.
2668    
2669     7. A lesser problem with the same optimization is that it was recording the
2670     first character of an anchored pattern as "needed", thus provoking a search
2671     right along the subject, even when the first match of the pattern was going to
2672     fail. The "needed" character is now not set for anchored patterns, unless it
2673     follows something in the pattern that is of non-fixed length. Thus, it still
2674     fulfils its original purpose of finding quick non-matches in cases of nested
2675     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2676    
2677    
2678     Version 4.0 17-Feb-03
2679     ---------------------
2680    
2681 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2682     extended to the end of string, PCRE compiled incorrect data. This could lead to
2683     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2684    
2685     2. Moved to autoconf 2.53 and libtool 1.4.2.
2686    
2687     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2688     the special perltest8 script is no longer needed - all the tests can be run
2689     from a single perltest script.
2690    
2691     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2692     by \s. It has now been removed in PCRE. This means it isn't recognized as
2693     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2694     class [:space:] *does* include VT, thereby creating a mess.
2695    
2696     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2697     space and tab.
2698    
2699     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2700     its new features into the main test script, reducing the number of scripts.
2701    
2702     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2703     were backward compatible, and made the (?i) apply to the whole pattern, as if
2704     /i were given. Now it behaves more logically, and applies the option setting
2705     only to what follows. PCRE has been changed to follow suit. However, if it
2706     finds options settings right at the start of the pattern, it extracts them into
2707     the global options, as before. Thus, they show up in the info data.
2708    
2709     8. Added support for the \Q...\E escape sequence. Characters in between are
2710     treated as literals. This is slightly different from Perl in that $ and @ are
2711     also handled as literals inside the quotes. In Perl, they will cause variable
2712     interpolation. Note the following examples:
2713    
2714     Pattern PCRE matches Perl matches
2715    
2716     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2717     \Qabc\$xyz\E abc\$xyz abc\$xyz
2718     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2719    
2720     For compatibility with Perl, \Q...\E sequences are recognized inside character
2721     classes as well as outside them.
2722    
2723     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2724     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2725     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2726     signed/unsigned warnings.
2727    
2728     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2729     option for pcretest, so I've replaced it by a simple function that does just
2730     that job.
2731    
2732     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2733     "pcregrep -".
2734    
2735     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2736     Java package. This provides some syntactic sugar for simple cases of what my
2737     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2738     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2739     item, you can use this simplified notation. Note that only makes sense with
2740     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2741     greediness, whatever the setting of the PCRE_UNGREEDY option.
2742    
2743     13. A change of greediness default within a pattern was not taking effect at
2744     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2745     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2746     was abstracted outside.
2747    
2748     14. PCRE now supports the \G assertion. It is true when the current matching
2749     position is at the start point of the match. This differs from \A when the
2750     starting offset is non-zero. Used with the /g option of pcretest (or similar
2751     code), it works in the same way as it does for Perl's /g option. If all
2752     alternatives of a regex begin with \G, the expression is anchored to the start
2753     match position, and the "anchored" flag is set in the compiled expression.
2754    
2755     15. Some bugs concerning the handling of certain option changes within patterns
2756     have been fixed. These applied to options other than (?ims). For example,
2757     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2758     been the other way round. Some of this was related to change 7 above.
2759    
2760     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2761     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2762     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2763     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2764    
2765     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2766     mode. Unlike ".", it always matches newline, whatever the setting of
2767     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2768     assertions. Perl allows it, but it doesn't (in general) work because it can't
2769     calculate the length of the lookbehind. At least, that's the case for Perl
2770     5.8.0 - I've been told they are going to document that it doesn't work in
2771     future.
2772    
2773     18. Added an error diagnosis for escapes that PCRE does not support: these are
2774     \L, \l, \N, \P, \p, \U, \u, and \X.
2775    
2776     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2777     reading past the end of the pattern in cases such as /[abcd/.
2778    
2779     20. PCRE was getting more memory than necessary for patterns with classes that
2780     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2781    
2782     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2783     compiling PCRE for use with Virtual Pascal.
2784    
2785     22. Small fix to the Makefile to make it work properly if the build is done
2786     outside the source tree.
2787    
2788     23. Added a new extension: a condition to go with recursion. If a conditional
2789     subpattern starts with (?(R) the "true" branch is used if recursion has
2790     happened, whereas the "false" branch is used only at the top level.
2791    
2792     24. When there was a very long string of literal characters (over 255 bytes
2793     without UTF support, over 250 bytes with UTF support), the computation of how
2794     much memory was required could be incorrect, leading to segfaults or other
2795     strange effects.
2796    
2797     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2798     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2799     there was a subsequent back reference to those brackets. This meant that, for
2800     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2801     possible to check for precisely this case. All we can do is abandon the
2802     optimization if .* occurs inside capturing brackets when there are any back
2803     references whatsoever. (See below for a better fix that came later.)
2804    
2805     26. The handling of the optimization for finding the first character of a
2806     non-anchored pattern, and for finding a character that is required later in the
2807     match were failing in some cases. This didn't break the matching; it just
2808     failed to optimize when it could. The way this is done has been re-implemented.
2809    
2810     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2811    
2812     28. Added a new feature that provides some of the functionality that Perl
2813     provides with (?{...}). The facility is termed a "callout". The way it is done
2814     in PCRE is for the caller to provide an optional function, by setting
2815     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2816     global variable. By default it is unset, which disables all calling out. To get
2817     the function called, the regex must include (?C) at appropriate points. This
2818     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2819     This provides a means of identifying different callout points. When PCRE
2820     reaches such a point in the regex, if pcre_callout has been set, the external
2821     function is called. It is provided with data in a structure called
2822     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2823     matching continues; if it returns a non-zero value, the match at the current
2824     point fails. However, backtracking will occur if possible. [This was changed
2825     later and other features added - see item 49 below.]
2826    
2827     29. pcretest is upgraded to test the callout functionality. It provides a
2828     callout function that displays information. By default, it shows the start of
2829     the match and the current position in the text. There are some new data escapes
2830     to vary what happens:
2831    
2832     \C+ in addition, show current contents of captured substrings
2833     \C- do not supply a callout function
2834     \C!n return 1 when callout number n is reached
2835     \C!n!m return 1 when callout number n is reached for the mth time
2836    
2837     30. If pcregrep was called with the -l option and just a single file name, it
2838     output "<stdin>" if a match was found, instead of the file name.
2839    
2840     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2841     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2842     pcre_exec(). This saves a malloc/free per call. The default value of
2843     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2844     when configuring.
2845    
2846     32. The default maximum size of a compiled pattern is 64K. There have been a
2847     few cases of people hitting this limit. The code now uses macros to handle the
2848     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2849     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2850     configuring. Tests 2 and 5 work only with 2-byte links because they output
2851     debugging information about compiled patterns.
2852    
2853     33. Internal code re-arrangements:
2854    
2855     (a) Moved the debugging function for printing out a compiled regex into
2856     its own source file (printint.c) and used #include to pull it into
2857     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2858     separate copies.
2859    
2860     (b) Defined the list of op-code names for debugging as a macro in
2861     internal.h so that it is next to the definition of the opcodes.
2862    
2863     (c) Defined a table of op-code lengths for simpler skipping along compiled
2864     code. This is again a macro in internal.h so that it is next to the
2865     definition of the opcodes.
2866    
2867     34. Added support for recursive calls to individual subpatterns, along the
2868     lines of Robin Houston's patch (but implemented somewhat differently).
2869    
2870     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2871     allow it to read and process whole directories in Win32. This code was
2872     contributed by Lionel Fourquaux; it has not been tested by me.
2873    
2874     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2875     used to name a group. Names consist of alphanumerics and underscores, and must
2876     be unique. Back references use the syntax (?P=name) and recursive calls use
2877     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2878     numbers. The function pcre_fullinfo() can be used after compilation to extract
2879     a name/number map. There are three relevant calls:
2880    
2881     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2882     PCRE_INFO_NAMECOUNT yields the number of entries
2883     PCRE_INFO_NAMETABLE yields a pointer to the map.
2884    
2885     The map is a vector of fixed-size entries. The size of each entry depends on
2886     the length of the longest name used. The first two bytes of each entry are the
2887     group number, most significant byte first. There follows the corresponding
2888     name, zero terminated. The names are in alphabetical order.
2889    
2890     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2891     case instead of 255. Making it the same both with and without UTF-8 support
2892     means that the same test output works with both.
2893    
2894     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2895     calling malloc() with a zero argument.
2896    
2897     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2898     optimization. I've improved things by keeping a bitmap of backreferences with
2899     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2900     fact referenced, the optimization can be applied. It is unlikely that a
2901     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2902     the match to follow \n) will appear inside brackets with a number greater than
2903     31, but if it does, any back reference > 31 suppresses the optimization.
2904    
2905     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2906     of disabling numbered capturing parentheses. Any opening parenthesis that is
2907     not followed by ? behaves as if it were followed by ?: but named parentheses
2908     can still be used for capturing (and they will acquire numbers in the usual
2909     way).
2910    
2911     41. Redesigned the return codes from the match() function into yes/no/error so
2912     that errors can be passed back from deep inside the nested calls. A malloc
2913     failure while inside a recursive subpattern call now causes the
2914     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2915    
2916     42. It is now possible to set a limit on the number of times the match()
2917     function is called in a call to pcre_exec(). This facility makes it possible to
2918     limit the amount of recursion and backtracking, though not in a directly
2919     obvious way, because the match() function is used in a number of different
2920     circumstances. The count starts from zero for each position in the subject
2921     string (for non-anchored patterns). The default limit is, for compatibility, a
2922     large number, namely 10 000 000. You can change this in two ways:
2923    
2924     (a) When configuring PCRE before making, you can use --with-match-limit=n
2925     to set a default value for the compiled library.
2926    
2927     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2928     a different value is set. See 45 below.
2929    
2930     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2931    
2932     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2933     of things that can be changed at compile time. The first argument specifies
2934     what is wanted and the second points to where the information is to be placed.
2935     The current list of available information is:
2936    
2937     PCRE_CONFIG_UTF8
2938    
2939     The output is an integer that is set to one if UTF-8 support is available;
2940     otherwise it is set to zero.
2941    
2942     PCRE_CONFIG_NEWLINE
2943    
2944     The output is an integer that it set to the value of the code that is used for
2945     newline. It is either LF (10) or CR (13).
2946    
2947     PCRE_CONFIG_LINK_SIZE
2948    
2949     The output is an integer that contains the number of bytes used for internal
2950     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2951    
2952     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2953    
2954     The output is an integer that contains the threshold above which the POSIX
2955     interface uses malloc() for output vectors. See item 31 above.
2956    
2957     PCRE_CONFIG_MATCH_LIMIT
2958    
2959     The output is an unsigned integer that contains the default limit of the number
2960     of match() calls in a pcre_exec() execution. See 42 above.
2961    
2962     44. pcretest has been upgraded by the addition of the -C option. This causes it
2963     to extract all the available output from the new pcre_config() function, and to
2964     output it. The program then exits immediately.
2965    
2966     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2967     order to support additional features. One way would have been to define
2968     pcre_exec2() (for example) with extra arguments, but this would not have been
2969     extensible, and would also have required all calls to the original function to
2970     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2971     is used for passing in "extra" data from pcre_study().
2972    
2973     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2974     contains the following fields:
2975    
2976     flags a bitmap indicating which of the following fields are set
2977     study_data opaque data from pcre_study()
2978     match_limit a way of specifying a limit on match() calls for a specific
2979     call to pcre_exec()
2980     callout_data data for callouts (see 49 below)
2981    
2982     The flag bits are also defined in pcre.h, and are
2983    
2984     PCRE_EXTRA_STUDY_DATA
2985     PCRE_EXTRA_MATCH_LIMIT
2986     PCRE_EXTRA_CALLOUT_DATA
2987    
2988     The pcre_study() function now returns one of these new pcre_extra blocks, with
2989     the actual study data pointed to by the study_data field, and the
2990     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2991     before. That is, this change is entirely upwards-compatible and requires no
2992     change to existing code.
2993    
2994     If you want to pass in additional data to pcre_exec(), you can either place it
2995     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2996     block.
2997    
2998     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2999     data string contains the escape sequence \M, pcretest calls pcre_exec() several
3000     times with different match limits, until it finds the minimum value needed for
3001     pcre_exec() to complete. The value is then output. This can be instructive; for
3002     most simple matches the number is quite small, but for pathological cases it
3003     gets very large very quickly.
3004    
3005     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3006     returns the size of the data block pointed to by the study_data field in a
3007     pcre_extra block, that is, the value that was passed as the argument to
3008     pcre_malloc() when PCRE was getting memory in which to place the information
3009     created by pcre_study(). The fourth argument should point to a size_t variable.
3010     pcretest has been extended so that this information is shown after a successful
3011     pcre_study() call when information about the compiled regex is being displayed.
3012    
3013     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3014     because what follows is always an absolute path. (Later: it turns out that this
3015     is more than cosmetic for MinGW, because it doesn't like empty path
3016     components.)
3017    
3018     49. Some changes have been made to the callout feature (see 28 above):
3019    
3020     (i) A callout function now has three choices for what it returns:
3021    
3022     0 => success, carry on matching
3023     > 0 => failure at this point, but backtrack if possible
3024     < 0 => serious error, return this value from pcre_exec()
3025    
3026     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3027     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3028     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3029     use by callout functions. It will never be used by PCRE itself.
3030    
3031     (ii) The pcre_extra structure (see 45 above) has a void * field called
3032     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3033     pcre_callout_block structure has a field of the same name. The contents of
3034     the field passed in the pcre_extra structure are passed to the callout
3035     function in the corresponding field in the callout block. This makes it
3036     easier to use the same callout-containing regex from multiple threads. For
3037     testing, the pcretest program has a new data escape
3038    
3039     \C*n pass the number n (may be negative) as callout_data
3040    
3041     If the callout function in pcretest receives a non-zero value as
3042     callout_data, it returns that value.
3043    
3044     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3045     there were some redundant $(CFLAGS) in commands that are now specified as
3046     $(LINK), which already includes $(CFLAGS).
3047    
3048     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3049     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3050     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3051     one-byte characters throughout. Note that case-insensitive matching applies
3052     only to characters whose values are less than 256. PCRE doesn't support the
3053     notion of cases for higher-valued characters.
3054    
3055     (i) A character class whose characters are all within 0-255 is handled as
3056     a bit map, and the map is inverted for negative classes. Previously, a
3057     character > 255 always failed to match such a class; however it should
3058     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3059    
3060     (ii) A negated character class with a single character < 255 is coded as
3061     "not this character" (OP_NOT). This wasn't working properly when the test
3062     character was multibyte, either singly or repeated.
3063    
3064     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3065     mode, for example: \x{100}{2,3}.
3066    
3067     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3068     singly or repeated) now correctly test multibyte characters. However,
3069     PCRE doesn't recognize any characters with values greater than 255 as
3070     digits, spaces, or word characters. Such characters always match \D, \S,
3071     and \W, and never match \d, \s, or \w.
3072    
3073     (v) Classes may now contain characters and character ranges with values
3074     greater than 255. For example: [ab\x{100}-\x{400}].
3075    
3076     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3077     PCRE in UTF-8 mode.
3078    
3079     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3080     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3081     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3082     value.)
3083    
3084     53. The single man page has become too large. I have therefore split it up into
3085     a number of separate man pages. These also give rise to individual HTML pages;
3086     these are now put in a separate directory, and there is an index.html page that
3087     lists them all. Some hyperlinking between the pages has been installed.
3088    
3089     54. Added convenience functions for handling named capturing parentheses.
3090    
3091     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3092     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3093     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3094     are faulted.
3095    
3096     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3097     calling configure. These values are used when compiling the dftables.c program
3098     which is run to generate the source of the default character tables. They
3099     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3100     you will need to set these values.
3101    
3102     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3103    
3104    
3105     Version 3.9 02-Jan-02
3106 nigel 61 ---------------------
3107    
3108     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3109    
3110     2. If --disable-static was given, the building process failed when trying to
3111     build pcretest and pcregrep. (For some reason it was using libtool to compile
3112     them, which is not right, as they aren't part of the library.)
3113    
3114    
3115 nigel 59 Version 3.8 18-Dec-01
3116     ---------------------
3117    
3118     1. The experimental UTF-8 code was completely screwed up. It was packing the
3119     bytes in the wrong order. How dumb can you get?
3120    
3121    
3122 nigel 57 Version 3.7 29-Oct-01
3123     ---------------------
3124    
3125     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3126     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3127     this didn't happen under Solaris 8, where I normally test things.
3128    
3129 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3130     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3131     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3132     this fix an hour or so after the initial 3.7 release.)
3133 nigel 57
3134 nigel 59
3135 nigel 55 Version 3.6 23-Oct-01
3136     ---------------------
3137    
3138     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3139     offsets passed as NULL with zero offset count.
3140    
3141     2. The config.guess and config.sub files had not been updated when I moved to
3142     the latest autoconf.
3143    
3144    
3145 nigel 53 Version 3.5 15-Aug-01
3146     ---------------------
3147 nigel 5
3148 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3149     had been forgotten.
3150    
3151     2. By using declared but undefined structures, we can avoid using "void"
3152     definitions in pcre.h while keeping the internal definitions of the structures
3153     private.
3154    
3155     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3156     user point of view, this means that both static and shared libraries are built
3157     by default, but this can be individually controlled. More of the work of
3158     handling this static/shared cases is now inside libtool instead of PCRE's make
3159     file.
3160    
3161     4. The pcretest utility is now installed along with pcregrep because it is
3162     useful for users (to test regexs) and by doing this, it automatically gets
3163     relinked by libtool. The documentation has been turned into a man page, so
3164     there are now .1, .txt, and .html versions in /doc.
3165    
3166     5. Upgrades to pcregrep:
3167     (i) Added long-form option names like gnu grep.
3168     (ii) Added --help to list all options with an explanatory phrase.
3169     (iii) Added -r, --recursive to recurse into sub-directories.
3170     (iv) Added -f, --file to read patterns from a file.
3171    
3172     6. pcre_exec() was referring to its "code" argument before testing that
3173     argument for NULL (and giving an error if it was NULL).
3174    
3175     7. Upgraded Makefile.in to allow for compiling in a different directory from
3176     the source directory.
3177    
3178     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3179     options bits, the pointer it was passed was to an int instead of to an unsigned
3180     long int. This mattered only on 64-bit systems.
3181    
3182     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3183     generated) instead of pcre.in, which it its source. Also made the same change
3184     in several of the .c files.
3185    
3186     10. A new release of gcc defines printf() as a macro, which broke pcretest
3187     because it had an ifdef in the middle of a string argument for printf(). Fixed
3188     by using separate calls to printf().
3189    
3190     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3191     script, to force use of CR or LF instead of \n in the source. On non-Unix
3192     systems, the value can be set in config.h.
3193    
3194     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3195     absolute limit. Changed the text of the error message to make this clear, and
3196     likewise updated the man page.
3197    
3198     13. The limit of 99 on the number of capturing subpatterns has been removed.
3199     The new limit is 65535, which I hope will not be a "real" limit.
3200    
3201    
3202 nigel 51 Version 3.4 22-Aug-00
3203     ---------------------
3204    
3205     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3206    
3207     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3208    
3209    
3210 nigel 49 Version 3.3 01-Aug-00
3211     ---------------------
3212    
3213     1. If an octal character was given, but the value was greater than \377, it
3214     was not getting masked to the least significant bits, as documented. This could
3215     lead to crashes in some systems.
3216    
3217     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3218     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3219    
3220     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3221     These just pass their arguments on to (pcre_free)(), but they are provided
3222     because some uses of PCRE bind it to non-C systems that can call its functions,
3223     but cannot call free() or pcre_free() directly.
3224    
3225     4. Add "make test" as a synonym for "make check". Corrected some comments in
3226     the Makefile.
3227    
3228     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3229     Makefile.
3230    
3231     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3232     command called pgrep for grepping around the active processes.
3233    
3234     7. Added the beginnings of support for UTF-8 character strings.
3235    
3236     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3237     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3238     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3239     out for the ar command.)
3240    
3241    
3242 nigel 47 Version 3.2 12-May-00
3243     ---------------------
3244    
3245     This is purely a bug fixing release.
3246    
3247     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3248     of ZA. This was just one example of several cases that could provoke this bug,
3249     which was introduced by change 9 of version 2.00. The code for breaking
3250     infinite loops after an iteration that matches an empty string was't working
3251     correctly.
3252    
3253     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3254     when matched against abbab (for example). After matching an empty string, it
3255     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3256     caused it to match further down the string than it should.
3257    
3258     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3259     was there because it doesn't seem to be needed, and it causes trouble on some
3260     systems, as it is not a Standard C header. It has been removed.
3261    
3262     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3263     were reported on the Macintosh. The changes were from
3264    
3265     while ((c = *(++ptr)) != 0 && c != '\n');
3266     to
3267     while ((c = *(++ptr)) != 0 && c != '\n') ;
3268    
3269     Totally extraordinary, but if that's what it takes...
3270    
3271     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3272     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3273     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3274     assumes the way PCRE uses memmove() (always moving upwards).
3275    
3276     6. PCRE is being used in one environment where strchr() is not available. There
3277     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3278     faster code anyway.
3279    
3280    
3281 nigel 45 Version 3.1 09-Feb-00
3282     ---------------------
3283    
3284     The only change in this release is the fixing of some bugs in Makefile.in for
3285     the "install" target:
3286    
3287     (1) It was failing to install pcreposix.h.
3288    
3289     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3290    
3291    
3292 nigel 43 Version 3.0 01-Feb-00
3293     ---------------------
3294 nigel 41
3295     1. Add support for the /+ modifier to perltest (to output $` like it does in
3296     pcretest).
3297    
3298     2. Add support for the /g modifier to perltest.
3299    
3300     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3301     matches null strings.
3302    
3303     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3304     pattern. Perl treats empty patterns specially - it reuses the most recent
3305     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3306     effect.
3307    
3308     5. The POSIX interface was broken in that it was just handing over the POSIX
3309     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3310     required a bigger vector, with some working space on the end. This means that
3311     the POSIX wrapper now has to get and free some memory, and copy the results.
3312    
3313 nigel 43 6. Added some simple autoconf support, placing the test data and the
3314     documentation in separate directories, re-organizing some of the
3315     information files, and making it build pcre-config (a GNU standard). Also added
3316     libtool support for building PCRE as a shared library, which is now the
3317     default.
3318 nigel 41
3319 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3320     09 are not valid octal constants. Single digits will be used for minor values
3321     less than 10.
3322    
3323     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3324     existing programs that set these in the POSIX interface can use PCRE without
3325     modification.
3326    
3327     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3328     return all that pcre_info() returns, plus additional data. The pcre_info()
3329     function is retained for compatibility, but is considered to be obsolete.
3330    
3331     10. Added experimental recursion feature (?R) to handle one common case that
3332     Perl 5.6 will be able to do with (?p{...}).
3333    
3334     11. Added support for POSIX character classes like [:alpha:], which Perl is
3335     adopting.
3336    
3337    
3338 nigel 39 Version 2.08 31-Aug-99
3339     ----------------------
3340    
3341     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3342     trying to match at the startoffset position, but instead was moving forward to
3343     the next newline as if a previous match had failed.
3344    
3345     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3346     and could get into a loop if a null string was matched other than at the start
3347     of the subject.
3348    
3349     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3350     be distinguished at compile time, and for completeness also added PCRE_DATE.
3351    
3352     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3353     in GnuWin32 environments.
3354    
3355    
3356 nigel 37 Version 2.07 29-Jul-99
3357     ----------------------
3358    
3359     1. The documentation is now supplied in plain text form and HTML as well as in
3360     the form of man page sources.
3361    
3362     2. C++ compilers don't like assigning (void *) values to other pointer types.
3363     In particular this affects malloc(). Although there is no problem in Standard
3364     C, I've put in casts to keep C++ compilers happy.
3365    
3366     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3367     should be (const char *).
3368    
3369     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3370     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3371     However, I haven't made this a standard facility. The documentation doesn't
3372     mention it, and the Makefile doesn't support it.
3373    
3374     5. The Makefile now contains an "install" target, with editable destinations at
3375     the top of the file. The pcretest program is not installed.
3376    
3377     6. pgrep -V now gives the PCRE version number and date.
3378    
3379     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3380     causing the entire string to be ignored, instead of just the last character.
3381    
3382     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3383     non-matching string, it can take a very, very long time, even for strings of
3384     quite modest length, because of the nested recursion. PCRE now does better in
3385     some of these cases. It does this by remembering the last required literal
3386     character in the pattern, and pre-searching the subject to ensure it is present
3387     before running the real match. In other words, it applies a heuristic to detect
3388     some types of certain failure quickly, and in the above example, if presented
3389     with a string that has no trailing " it gives "no match" very quickly.
3390    
3391     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3392     other alternatives are tried instead.
3393    
3394    
3395 nigel 35 Version 2.06 09-Jun-99
3396     ----------------------
3397    
3398     1. Change pcretest's output for amount of store used to show just the code
3399     space, because the remainder (the data block) varies in size between 32-bit and
3400     64-bit systems.
3401    
3402     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3403     start matching at. This allows lookbehinds to work when searching for multiple
3404     occurrences in a string.
3405    
3406     3. Added additional options to pcretest for testing multiple occurrences:
3407    
3408     /+ outputs the rest of the string that follows a match
3409     /g loops for multiple occurrences, using the new startoffset argument
3410     /G loops for multiple occurrences by passing an incremented pointer
3411    
3412     4. PCRE wasn't doing the "first character" optimization for patterns starting
3413     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3414     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3415     the letter 'x'. On long subject strings, this gives a significant speed-up.
3416    
3417    
3418 nigel 33 Version 2.05 21-Apr-99
3419     ----------------------
3420    
3421     1. Changed the type of magic_number from int to long int so that it works
3422     properly on 16-bit systems.
3423    
3424     2. Fixed a bug which caused patterns starting with .* not to work correctly
3425     when the subject string contained newline characters. PCRE was assuming
3426     anchoring for such patterns in all cases, which is not correct because .* will
3427     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3428     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3429     must be retried after every newline in the subject.
3430    
3431    
3432 nigel 31 Version 2.04 18-Feb-99
3433     ----------------------
3434    
3435     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3436     computation of the store needed to hold the pattern was incorrect (too large).
3437     If such patterns were nested a few deep, this could multiply and become a real
3438     problem.
3439    
3440     2. Added /M option to pcretest to show the memory requirement of a specific
3441     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3442    
3443     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3444     compiled in such a way that the backtracking after subsequent failure was
3445     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3446     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3447    
3448    
3449 nigel 29 Version 2.03 02-Feb-99
3450     ----------------------
3451    
3452     1. Fixed typo and small mistake in man page.
3453    
3454 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3455     LICENCE file containing the conditions.
3456 nigel 29
3457     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3458     Perl, that is the internal \ allows the delimiter to be included in the
3459     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3460     the final delimiter, add \ to the end of the pattern (to test the error).
3461    
3462     4. Added the convenience functions for extracting substrings after a successful
3463     match. Updated pcretest to make it able to test these functions.
3464    
3465    
3466 nigel 27 Version 2.02 14-Jan-99
3467     ----------------------
3468    
3469     1. Initialized the working variables associated with each extraction so that
3470     their saving and restoring doesn't refer to uninitialized store.
3471    
3472     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3473     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3474     fix the problem.
3475    
3476     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3477     calls, and wasn't printing the correct value for compiling calls. Increased the
3478     default value of LOOPREPEAT, and the number of significant figures in the
3479     times.
3480    
3481     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3482    
3483     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3484     a building problem on Windows NT with a FAT file system.
3485    
3486    
3487 nigel 25 Version 2.01 21-Oct-98
3488     ----------------------
3489    
3490     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3491     to character tables built by pcre_maketables() in the current locale. If NULL
3492     is passed, the default tables are used.
3493    
3494    
3495 nigel 23 Version 2.00 24-Sep-98
3496 nigel 21 ----------------------
3497    
3498 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3499     it any more.
3500    
3501     2. Allow quantification of (?>) groups, and make it work correctly.
3502    
3503     3. The first character computation wasn't working for (?>) groups.
3504    
3505     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3506     end of the subject) and add 5.005's \z, which really does match only at the
3507     very end of the subject.
3508    
3509     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3510    
3511     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3512     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3513     localized options. All options to pcre_study() were also removed.
3514    
3515     7. Add other new features from 5.005:
3516    
3517     $(?<= positive lookbehind
3518     $(?<! negative lookbehind
3519     (?imsx-imsx) added the unsetting capability
3520     such a setting is global if at outer level; local otherwise
3521     (?imsx-imsx:) non-capturing groups with option setting
3522     (?(cond)re|re) conditional pattern matching
3523    
3524     A backreference to itself in a repeated group matches the previous
3525     captured string.
3526    
3527     8. General tidying up of studying (both automatic and via "study")
3528     consequential on the addition of new assertions.
3529    
3530     9. As in 5.005, unlimited repeated groups that could match an empty substring
3531     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3532     runtime if any iteration does actually match an empty substring.
3533    
3534     10. Include the RunTest script in the distribution.
3535    
3536     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3537     discrepancies, some of which were old and were also with respect to 5.004. They
3538     have now been fixed.
3539    
3540    
3541     Version 1.09 28-Apr-98
3542     ----------------------
3543    
3544 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3545     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3546     program crashes, or just wrong answers. This did not apply to negated classes
3547     containing more than one character, or to minima other than one.
3548    
3549    
3550 nigel 19 Version 1.08 27-Mar-98
3551     ----------------------
3552    
3553     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3554    
3555     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3556     latter must appear before anything that relies on it in the pattern.
3557    
3558    
3559 nigel 17 Version 1.07 16-Feb-98
3560     ----------------------
3561    
3562     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3563     repeat of a potentially empty string).
3564    
3565    
3566 nigel 15 Version 1.06 23-Jan-98
3567     ----------------------
3568    
3569     1. Added Markus Oberhumer's little patches for C++.
3570    
3571     2. Literal strings longer than 255 characters were broken.
3572    
3573    
3574 nigel 13 Version 1.05 23-Dec-97
3575     ----------------------
3576    
3577     1. Negated character classes containing more than one character were failing if
3578     PCRE_CASELESS was set at run time.
3579    
3580    
3581 nigel 11 Version 1.04 19-Dec-97
3582     ----------------------
3583    
3584     1. Corrected the man page, where some "const" qualifiers had been omitted.
3585    
3586     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3587     input syntax.
3588    
3589     3. Fixed memory leak which occurred when a regex with back references was
3590     matched with an offsets vector that wasn't big enough. The temporary memory
3591     that is used in this case wasn't being freed if the match failed.
3592    
3593     4. Tidied pcretest to ensure it frees memory that it gets.
3594    
3595     5. Temporary memory was being obtained in the case where the passed offsets
3596     vector was exactly big enough.
3597    
3598     6. Corrected definition of offsetof() from change 5 below.
3599    
3600     7. I had screwed up change 6 below and broken the rules for the use of
3601     setjmp(). Now fixed.
3602    
3603    
3604 nigel 9 Version 1.03 18-Dec-97
3605     ----------------------
3606    
3607     1. A erroneous regex with a missing opening parenthesis was correctly
3608     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3609     on some systems.
3610    
3611     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3612     it was reported that one broken compiler failed on the former because "code" is
3613     also an independent variable.
3614    
3615     3. The erroneous regex a[]b caused an array overrun reference.
3616    
3617     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3618     fail on data ending with that character. (It was going on too far, and checking
3619     the next character, typically a binary zero.) This was specific to the
3620     optimized code for single-character negative classes.
3621    
3622     5. Added a contributed patch from the TIN world which does the following:
3623    
3624     + Add an undef for memmove, in case the the system defines a macro for it.
3625    
3626     + Add a definition of offsetof(), in case there isn't one. (I don't know
3627     the reason behind this - offsetof() is part of the ANSI standard - but
3628     it does no harm).
3629    
3630     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3631     most of the places where whitespace preceded '#'. I have given up and
3632     allowed the remaining 2 cases to be at the margin.
3633    
3634     + Rename some variables in pcre to eliminate shadowing. This seems very
3635     pedantic, but does no harm, of course.
3636    
3637     6. Moved the call to setjmp() into its own function, to get rid of warnings
3638     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3639    
3640     7. Constructs such as \d{8,} were compiling into the equivalent of
3641 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3642 nigel 9 outcome, but in this particular case used more store than had been allocated,
3643     which caused the bug to be discovered because it threw up an internal error.
3644    
3645     8. The debugging code in both pcre and pcretest for outputting the compiled
3646     form of a regex was going wrong in the case of back references followed by
3647     curly-bracketed repeats.
3648    
3649    
3650 nigel 7 Version 1.02 12-Dec-97
3651     ----------------------
3652    
3653     1. Typos in pcre.3 and comments in the source fixed.
3654    
3655     2. Applied a contributed patch to get rid of places where it used to remove
3656     'const' from variables, and fixed some signed/unsigned and uninitialized
3657     variable warnings.
3658    
3659     3. Added the "runtest" target to Makefile.
3660    
3661     4. Set default compiler flag to -O2 rather than just -O.
3662    
3663    
3664 nigel 5 Version 1.01 19-Nov-97
3665     ----------------------
3666    
3667     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3668     like /([ab]*)*/, that is, for classes with more than one character in them.
3669    
3670     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3671     as /((?>a*))*/ (a PCRE_EXTRA facility).
3672    
3673    
3674     Version 1.00 18-Nov-97
3675     ----------------------
3676    
3677     1. Added compile-time macros to support systems such as SunOS4 which don't have
3678     memmove() or strerror() but have other things that can be used instead.
3679    
3680     2. Arranged that "make clean" removes the executables.
3681    
3682    
3683 nigel 3 Version 0.99 27-Oct-97
3684     ----------------------
3685    
3686     1. Fixed bug in code for optimizing classes with only one character. It was
3687     initializing a 32-byte map regardless, which could cause it to run off the end
3688     of the memory it had got.
3689    
3690     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3691    
3692    
3693     Version 0.98 22-Oct-97
3694     ----------------------
3695    
3696     1. Fixed bug in code for handling temporary memory usage when there are more
3697     back references than supplied space in the ovector. This could cause segfaults.
3698    
3699    
3700     Version 0.97 21-Oct-97
3701     ----------------------
3702    
3703     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3704    
3705     2. Optimized negated single characters not to use a bit map.
3706    
3707     3. Brought error texts together as macro definitions; clarified some of them;
3708     fixed one that was wrong - it said "range out of order" when it meant "invalid
3709     escape sequence".
3710    
3711     4. Changed some char * arguments to const char *.
3712    
3713     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3714    
3715     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3716     pcretest.
3717    
3718    
3719     Version 0.96 16-Oct-97
3720     ----------------------
3721    
3722     1. Added a simple "pgrep" utility to the distribution.
3723    
3724     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3725     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3726     where "ddd" means "one or more decimal digits".
3727    
3728     3. Fixed serious bug. If a pattern had a back reference, but the call to
3729     pcre_exec() didn't supply a large enough ovector to record the related
3730     identifying subpattern, the match always failed. PCRE now remembers the number
3731     of the largest back reference, and gets some temporary memory in which to save
3732     the offsets during matching if necessary, in order to ensure that
3733     backreferences always work.
3734    
3735     4. Increased the compatibility with Perl in a number of ways:
3736    
3737     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3738     to request this handling. The option can be set at compile or exec time.
3739    
3740     (b) $ matches before a terminating newline by default; an option
3741     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3742     mode). The option can be set at compile or exec time.
3743    
3744     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3745     the same as Perl's. If the decimal number it represents is less than 10
3746     or there aren't that many previous left capturing parentheses, an octal
3747     escape is read. Inside a character class, it's always an octal escape,
3748     even if it is a single digit.
3749    
3750     (d) An escaped but undefined alphabetic character is taken as a literal,
3751     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3752     escapes.
3753    
3754     (e) {0} is now permitted. (The previous item is removed from the compiled
3755     pattern).
3756    
3757     5. Changed all the names of code files so that the basic parts are no longer
3758     than 10 characters, and abolished the teeny "globals.c" file.
3759    
3760     6. Changed the handling of character classes; they are now done with a 32-byte
3761     bit map always.
3762    
3763     7. Added the -d and /D options to pcretest to make it possible to look at the
3764     internals of compilation without having to recompile pcre.
3765    
3766    
3767