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Revision 498 - (hide annotations) (download)
Wed Mar 3 19:29:38 2010 UTC (4 years, 6 months ago) by ph10
File size: 182903 byte(s)
Fix missing data in coptable and poptable vectors; add compile-time checks for 
their lengths.

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 491
33 ph10 492
34 ph10 489 Version 8.01 19-Jan-2010
35     ------------------------
36 ph10 471
37     1. If a pattern contained a conditional subpattern with only one branch (in
38 ph10 489 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
39 ph10 473 computed the wrong minimum data length (which is of course zero for such
40 ph10 489 subpatterns). This could cause incorrect "no match" results.
41 ph10 473
42     2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
43 ph10 472 the pattern is reset in the first branch, pcre_compile() failed with
44     "internal error: code overflow at offset...". This happened only when
45 ph10 473 the reset was to the original external option setting. (An optimization
46     abstracts leading options settings into an external setting, which was the
47 ph10 472 cause of this.)
48 ph10 471
49 ph10 473 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
50     of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
51     assertion pattern did not match (meaning that the assertion was true), it
52     was incorrectly treated as false if the SKIP had been reached during the
53     matching. This also applied to assertions used as conditions.
54 ph10 471
55 ph10 473 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
56     assertion subpattern, including such a pattern used as a condition,
57     unpredictable results occurred, instead of the error return
58     PCRE_ERROR_DFA_UITEM.
59 ph10 478
60 ph10 474 5. The C++ GlobalReplace function was not working like Perl for the special
61     situation when an empty string is matched. It now does the fancy magic
62 ph10 478 stuff that is necessary.
63    
64     6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
65 ph10 475 removed. (These were left over from very, very early versions of PCRE.)
66 ph10 478
67 ph10 475 7. Some cosmetic changes to the code to make life easier when compiling it
68     as part of something else:
69 ph10 478
70     (a) Change DEBUG to PCRE_DEBUG.
71    
72     (b) In pcre_compile(), rename the member of the "branch_chain" structure
73     called "current" as "current_branch", to prevent a collision with the
74 ph10 475 Linux macro when compiled as a kernel module.
75 ph10 478
76     (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
77     prevent a collision with the Linux macro when compiled as a kernel
78 ph10 475 module.
79 ph10 478
80 ph10 475 8. In pcre_compile() there are some checks for integer overflows that used to
81     cast potentially large values to (double). This has been changed to that
82 ph10 478 when building, a check for int64_t is made, and if it is found, it is used
83     instead, thus avoiding the use of floating point arithmetic. (There is no
84     other use of FP in PCRE.) If int64_t is not found, the fallback is to
85     double.
86    
87     9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
88 ph10 476 2005 (difference between two addresses compared to an unsigned value).
89 ph10 473
90 ph10 478 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
91     custom one, because of the following reported problem in Windows:
92 ph10 473
93 ph10 478 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
94 ph10 489 under Win32.
95 ph10 478 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
96 ph10 489 therefore missing the function definition.
97 ph10 478 - The compiler thus generates a "C" signature for the test function.
98     - The linker fails to find the "C" function.
99     - PCRE fails to configure if asked to do so against libbz2.
100 ph10 486
101 ph10 479 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
102     messages were output:
103 ph10 478
104 ph10 479 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
105     rerunning libtoolize, to keep the correct libtool macros in-tree.
106     Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
107 ph10 486
108 ph10 479 I have done both of these things.
109 ph10 486
110 ph10 480 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
111 ph10 486 most of the time, it *can* run out if it is given a pattern that contains a
112     runaway infinite recursion. I updated the discussion in the pcrestack man
113     page.
114    
115     13. Now that we have gone to the x.xx style of version numbers, the minor
116     version may start with zero. Using 08 or 09 is a bad idea because users
117     might check the value of PCRE_MINOR in their code, and 08 or 09 may be
118     interpreted as invalid octal numbers. I've updated the previous comment in
119     configure.ac, and also added a check that gives an error if 08 or 09 are
120 ph10 481 used.
121 ph10 486
122 ph10 482 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
123 ph10 483 causing partial matching to fail when the end of the subject matched \W
124     in a UTF-8 pattern where \W was quantified with a minimum of 3.
125 ph10 486
126 ph10 483 15. There were some discrepancies between the declarations in pcre_internal.h
127 ph10 486 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
128 ph10 483 their definitions. The declarations used "const uschar *" and the
129     definitions used USPTR. Even though USPTR is normally defined as "const
130     unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
131     reported that: "This difference in casting confuses some C++ compilers, for
132     example, SunCC recognizes above declarations as different functions and
133 ph10 486 generates broken code for hbpcre." I have changed the declarations to use
134 ph10 483 USPTR.
135 ph10 486
136     16. GNU libtool is named differently on some systems. The autogen.sh script now
137 ph10 484 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
138     (FreeBSD).
139 ph10 478
140 ph10 486 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
141     (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
142     comment: "Figure out how to create a longlong from a string: strtoll and
143     equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
144     instance, but it only takes 2 args instead of 3!"
145 ph10 479
146 ph10 488 18. A subtle bug concerned with back references has been fixed by a change of
147     specification, with a corresponding code fix. A pattern such as
148     ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
149     refers, was giving matches when it shouldn't. For example, xa=xaaa would
150     match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
151     same bug. Such groups have to be quantified to be useful, or contained
152     inside another quantified group. (If there's no repetition, the reference
153     can never match.) The problem arises because, having left the group and
154     moved on to the rest of the pattern, a later failure that backtracks into
155     the group uses the captured value from the final iteration of the group
156     rather than the correct earlier one. I have fixed this in PCRE by forcing
157     any group that contains a reference to itself to be an atomic group; that
158     is, there cannot be any backtracking into it once it has completed. This is
159     similar to recursive and subroutine calls.
160 ph10 486
161 ph10 488
162 ph10 469 Version 8.00 19-Oct-09
163 ph10 418 ----------------------
164    
165     1. The table for translating pcre_compile() error codes into POSIX error codes
166 ph10 461 was out-of-date, and there was no check on the pcre_compile() error code
167     being within the table. This could lead to an OK return being given in
168 ph10 418 error.
169 ph10 461
170     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
171     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
172     in a Windows environment.
173    
174 ph10 420 3. The pcregrep --count option prints the count for each file even when it is
175     zero, as does GNU grep. However, pcregrep was also printing all files when
176     --files-with-matches was added. Now, when both options are given, it prints
177     counts only for those files that have at least one match. (GNU grep just
178 ph10 461 prints the file name in this circumstance, but including the count seems
179     more useful - otherwise, why use --count?) Also ensured that the
180 ph10 420 combination -clh just lists non-zero counts, with no names.
181 ph10 461
182     4. The long form of the pcregrep -F option was incorrectly implemented as
183     --fixed_strings instead of --fixed-strings. This is an incompatible change,
184     but it seems right to fix it, and I didn't think it was worth preserving
185     the old behaviour.
186    
187     5. The command line items --regex=pattern and --regexp=pattern were not
188 ph10 422 recognized by pcregrep, which required --regex pattern or --regexp pattern
189 ph10 461 (with a space rather than an '='). The man page documented the '=' forms,
190 ph10 422 which are compatible with GNU grep; these now work.
191 ph10 461
192     6. No libpcreposix.pc file was created for pkg-config; there was just
193 ph10 423 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
194 ph10 461
195 ph10 425 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
196 ph10 461 when UCP support is not needed, by modifying the Python script that
197 ph10 425 generates it from Unicode data files. This should not matter if the module
198     is correctly used as a library, but I received one complaint about 50K of
199     unwanted data. My guess is that the person linked everything into his
200     program rather than using a library. Anyway, it does no harm.
201 ph10 461
202 ph10 426 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
203 ph10 461 was a minimum greater than 1 for a wide character in a possessive
204 ph10 431 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
205     which had an unlimited repeat of a nested, fixed maximum repeat of a wide
206     character. Chaos in the form of incorrect output or a compiling loop could
207     result.
208 ph10 461
209 ph10 426 9. The restrictions on what a pattern can contain when partial matching is
210 ph10 461 requested for pcre_exec() have been removed. All patterns can now be
211 ph10 426 partially matched by this function. In addition, if there are at least two
212 ph10 435 slots in the offset vector, the offset of the earliest inspected character
213     for the match and the offset of the end of the subject are set in them when
214 ph10 461 PCRE_ERROR_PARTIAL is returned.
215    
216 ph10 428 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
217     synonymous with PCRE_PARTIAL, for backwards compatibility, and
218     PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
219 ph10 462 and may be more useful for multi-segment matching.
220 ph10 461
221     11. Partial matching with pcre_exec() is now more intuitive. A partial match
222     used to be given if ever the end of the subject was reached; now it is
223     given only if matching could not proceed because another character was
224     needed. This makes a difference in some odd cases such as Z(*FAIL) with the
225     string "Z", which now yields "no match" instead of "partial match". In the
226     case of pcre_dfa_exec(), "no match" is given if every matching path for the
227     final character ended with (*FAIL).
228    
229 ph10 428 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
230 ph10 461 if the pattern had a "must contain" character that was already found in the
231 ph10 428 earlier partial match, unless partial matching was again requested. For
232     example, with the pattern /dog.(body)?/, the "must contain" character is
233     "g". If the first part-match was for the string "dog", restarting with
234 ph10 435 "sbody" failed. This bug has been fixed.
235 ph10 461
236     13. The string returned by pcre_dfa_exec() after a partial match has been
237     changed so that it starts at the first inspected character rather than the
238     first character of the match. This makes a difference only if the pattern
239     starts with a lookbehind assertion or \b or \B (\K is not supported by
240     pcre_dfa_exec()). It's an incompatible change, but it makes the two
241 ph10 435 matching functions compatible, and I think it's the right thing to do.
242 ph10 461
243 ph10 435 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
244 ph10 461 so that the demonstration program is easily available in environments where
245     PCRE has not been installed from source.
246    
247 ph10 435 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
248 ph10 430 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
249     library.
250 ph10 461
251 ph10 435 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
252 ph10 432 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
253 ph10 461 is not the first non-POSIX option to be added. Clearly some people find
254 ph10 433 these options useful.
255 ph10 461
256     17. If a caller to the POSIX matching function regexec() passes a non-zero
257 ph10 438 value for nmatch with a NULL value for pmatch, the value of
258 ph10 461 nmatch is forced to zero.
259    
260 ph10 437 18. RunGrepTest did not have a test for the availability of the -u option of
261 ph10 461 the diff command, as RunTest does. It now checks in the same way as
262 ph10 437 RunTest, and also checks for the -b option.
263 ph10 461
264 ph10 438 19. If an odd number of negated classes containing just a single character
265     interposed, within parentheses, between a forward reference to a named
266 ph10 461 subpattern and the definition of the subpattern, compilation crashed with
267     an internal error, complaining that it could not find the referenced
268 ph10 438 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
269 ph10 461 [The bug was that it was starting one character too far in when skipping
270     over the character class, thus treating the ] as data rather than
271     terminating the class. This meant it could skip too much.]
272    
273 ph10 442 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
274 ph10 461 /g option in pcretest when the pattern contains \K, which makes it possible
275 ph10 442 to have an empty string match not at the start, even when the pattern is
276 ph10 461 anchored. Updated pcretest and pcredemo to use this option.
277    
278 ph10 446 21. If the maximum number of capturing subpatterns in a recursion was greater
279 ph10 461 than the maximum at the outer level, the higher number was returned, but
280     with unset values at the outer level. The correct (outer level) value is
281 ph10 446 now given.
282 ph10 461
283 ph10 447 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
284     PCRE did not set those parentheses (unlike Perl). I have now found a way to
285     make it do so. The string so far is captured, making this feature
286     compatible with Perl.
287 ph10 461
288     23. The tests have been re-organized, adding tests 11 and 12, to make it
289 ph10 448 possible to check the Perl 5.10 features against Perl 5.10.
290 ph10 461
291 ph10 454 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
292 ph10 461 pattern matches a fixed length string. PCRE did not allow this; now it
293     does. Neither allows recursion.
294    
295     25. I finally figured out how to implement a request to provide the minimum
296     length of subject string that was needed in order to match a given pattern.
297     (It was back references and recursion that I had previously got hung up
298     on.) This code has now been added to pcre_study(); it finds a lower bound
299 ph10 455 to the length of subject needed. It is not necessarily the greatest lower
300     bound, but using it to avoid searching strings that are too short does give
301     some useful speed-ups. The value is available to calling programs via
302     pcre_fullinfo().
303 ph10 461
304 ph10 455 26. While implementing 25, I discovered to my embarrassment that pcretest had
305     not been passing the result of pcre_study() to pcre_dfa_exec(), so the
306     study optimizations had never been tested with that matching function.
307     Oops. What is worse, even when it was passed study data, there was a bug in
308     pcre_dfa_exec() that meant it never actually used it. Double oops. There
309     were also very few tests of studied patterns with pcre_dfa_exec().
310 ph10 461
311 ph10 457 27. If (?| is used to create subpatterns with duplicate numbers, they are now
312     allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
313     on the other side of the coin, they are no longer allowed to have different
314     names, because these cannot be distinguished in PCRE, and this has caused
315     confusion. (This is a difference from Perl.)
316 ph10 461
317     28. When duplicate subpattern names are present (necessarily with different
318     numbers, as required by 27 above), and a test is made by name in a
319     conditional pattern, either for a subpattern having been matched, or for
320     recursion in such a pattern, all the associated numbered subpatterns are
321 ph10 459 tested, and the overall condition is true if the condition is true for any
322     one of them. This is the way Perl works, and is also more like the way
323     testing by number works.
324 ph10 418
325 ph10 461
326 ph10 412 Version 7.9 11-Apr-09
327 ph10 376 ---------------------
328    
329 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
330 ph10 376 (pcretest), all targets were linked against these libraries. This included
331     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
332     libraries. This caused unwanted dependencies to be created. This problem
333 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
334 ph10 376 pcretest is linked with readline.
335 ph10 392
336 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
337     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
338     moved outside it again, because FALSE and TRUE are already defined in AIX,
339     but BOOL is not.
340 ph10 392
341     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
342 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
343 ph10 392
344 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
345     hyphens) following file names and line numbers when outputting matching
346 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
347 ph10 376 wording for the --colour (or --color) option.
348 ph10 392
349 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
350     was not coloured; this is different to GNU grep, so I have changed it to be
351     the same.
352 ph10 392
353 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
354 ph10 392 each matching line was coloured. Now it goes on to look for further matches
355     of any of the test patterns, which is the same behaviour as GNU grep.
356    
357     7. A pattern that could match an empty string could cause pcregrep to loop; it
358     doesn't make sense to accept an empty string match in pcregrep, so I have
359 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
360     seems to be how GNU grep behaves.
361 ph10 392
362 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
363 ph10 392 start or after a newline", because the conditional assertion was not being
364     correctly handled. The rule now is that both the assertion and what follows
365     in the first alternative must satisfy the test.
366    
367 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
368 ph10 399 condition was an assertion, PCRE could crash during matching, both with
369     pcre_exec() and pcre_dfa_exec().
370 ph10 392
371     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
372     used for matching.
373    
374     11. Unicode property support in character classes was not working for
375 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
376 ph10 388
377 ph10 392 12. Added the -M command line option to pcretest.
378    
379 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
380 ph10 389
381     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
382 ph10 390
383 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
384 ph10 390 wrapper.
385 ph10 392
386 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
387 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
388 ph10 391 string constants.
389 ph10 405
390 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
391     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
392 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
393     these, but not everybody uses configure.
394    
395     19. A conditional group that had only one branch was not being correctly
396     recognized as an item that could match an empty string. This meant that an
397     enclosing group might also not be so recognized, causing infinite looping
398     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
399     with the subject "ab", where knowledge that the repeated group can match
400 ph10 396 nothing is needed in order to break the loop.
401 ph10 405
402 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
403 ph10 405 exec(), but without supplying a callout function, matching went wrong.
404    
405     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
406     leak if the size of the offset vector was greater than 30. When the vector
407     is smaller, the saved offsets during recursion go onto a local stack
408     vector, but for larger vectors malloc() is used. It was failing to free
409     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
410 ph10 400 error, in fact).
411 ph10 405
412 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
413 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
414     problem, but was untidy.
415 ph10 376
416 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
417     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
418     included within another project.
419 ph10 411
420 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
421     slightly modified by me:
422 ph10 411
423     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
424     not building pcregrep.
425    
426 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
427 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
428    
429 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
430     duplicate group numbers, could behave incorrectly or give incorrect errors,
431     because when scanning forward to find the reference group, PCRE was not
432     taking into account the duplicate group numbers. A pattern such as
433     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
434 ph10 411
435     26. Changed a few more instances of "const unsigned char *" to USPTR, making
436     the feature of a custom pointer more persuasive (as requested by a user).
437 ph10 416
438 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
439 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
440     pre-defined.
441 ph10 392
442 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
443    
444 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
445     in the configuration summary.
446 ph10 405
447 ph10 411
448 ph10 374 Version 7.8 05-Sep-08
449 ph10 349 ---------------------
450    
451     1. Replaced UCP searching code with optimized version as implemented for Ad
452     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
453 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
454     to 5 times on some simple patterns that I tested. Permission was given to
455     distribute the MultiStage2.py script that generates the tables (it's not in
456     the tarball, but is in the Subversion repository).
457 ph10 349
458 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
459     scripts.
460 ph10 358
461 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
462     a group with a zero qualifier. The result of the study could be incorrect,
463 ph10 358 or the function might crash, depending on the pattern.
464    
465     4. Caseless matching was not working for non-ASCII characters in back
466 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
467 ph10 358 It now works when Unicode Property Support is available.
468    
469 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
470     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
471     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
472 ph10 358 truncation.
473 ph10 349
474 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
475    
476 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
477     pointers, in case they are 64-bit values.
478 ph10 371
479     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
480     test 2 if it fails.
481    
482 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
483 ph10 371 and a #define of that name to empty if it is not externally set. This is to
484     allow users of MSVC to set it if necessary.
485    
486     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
487 ph10 359 the convenience functions in the pcre_get.c source file.
488 ph10 371
489 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
490     could cause overwriting and/or a crash. This command provoked a crash in
491 ph10 371 some environments:
492    
493     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
494    
495 ph10 360 This potential security problem was recorded as CVE-2008-2371.
496 ph10 371
497 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
498     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
499 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
500 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
501     pcretest so that it places the subject at the end of its malloc-ed buffer.
502 ph10 371
503 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
504 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
505    
506 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
507 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
508     first line. This applied both to normal and DFA matching.
509    
510 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
511 ph10 371 /^[^d]*?$/8 failed to match "abc".
512 ph10 351
513 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
514    
515     17. Make it more clear in the documentation that values returned from
516 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
517 ph10 357
518 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
519 ph10 368
520 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
521     supplied by Stefan Weber. I made a further small update for 7.8 because
522 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
523     replaced by pcre_ucd.c.
524 ph10 371
525 ph10 373
526 ph10 347 Version 7.7 07-May-08
527 ph10 321 ---------------------
528    
529     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
530 ph10 345 a string to a long long, pretend we don't even have a long long." This is
531 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
532 ph10 345
533 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
534     pre-7.6 versions, which defined a global no_arg variable instead of putting
535 ph10 332 it in the RE class. (See also #8 below.)
536 ph10 345
537     3. Remove a line of dead code, identified by coverity and reported by Nuno
538     Lopes.
539    
540 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
541 ph10 321
542 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
543 ph10 345 of files, instead of just to the final components.
544    
545 ph10 324 (2) If there was more than one level of directory, the subdirectories were
546     skipped unless they satisfied the include/exclude conditions. This is
547     inconsistent with GNU grep (and could even be seen as contrary to the
548     pcregrep specification - which I improved to make it absolutely clear).
549     The action now is always to scan all levels of directory, and just
550     apply the include/exclude patterns to regular files.
551 ph10 345
552 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
553 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
554    
555 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
556 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
557 ph10 326 doesn't support NULs in patterns.
558 ph10 345
559     7. Added some missing "const"s to declarations of static tables in
560     pcre_compile.c and pcre_dfa_exec.c.
561    
562 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
563 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
564 ph10 345 first patch. And a third patch - this was a messy problem.)
565 ph10 321
566 ph10 345 9. Applied Craig's patch to remove the use of push_back().
567    
568 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
569     matching function regexec().
570 ph10 345
571     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
572     which, however, unlike Perl's \g{...}, are subroutine calls, not back
573 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
574     Oniguruma does).
575 ph10 345
576     12. Previously, a group with a zero repeat such as (...){0} was completely
577 ph10 335 omitted from the compiled regex. However, this means that if the group
578     was called as a subroutine from elsewhere in the pattern, things went wrong
579 ph10 345 (an internal error was given). Such groups are now left in the compiled
580     pattern, with a new opcode that causes them to be skipped at execution
581 ph10 335 time.
582 ph10 345
583 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
584     to the way PCRE behaves:
585 ph10 345
586 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
587 ph10 345
588     (b) A back reference to an unmatched subpattern matches an empty string
589 ph10 336 (Perl fails the current match path).
590 ph10 345
591 ph10 341 (c) A data ] in a character class must be notated as \] because if the
592 ph10 345 first data character in a class is ], it defines an empty class. (In
593 ph10 341 Perl it is not possible to have an empty class.) The empty class []
594     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
595     The negative empty class [^] matches any one character, independently
596     of the DOTALL setting.
597 ph10 345
598     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
599 ph10 340 non-existent subpattern following a character class starting with ']' and
600     containing () gave an internal compiling error instead of "reference to
601     non-existent subpattern". Fortunately, when the pattern did exist, the
602 ph10 345 compiled code was correct. (When scanning forwards to check for the
603 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
604 ph10 345 the class, so got the count wrong. When actually compiling, the reference
605 ph10 340 was subsequently set up correctly.)
606 ph10 345
607 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
608 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
609     other assertions are supported. I have made pcre_dfa_exec() support
610     (*FAIL).
611    
612 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
613 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
614     cannot be changed at match time, I realized I could make a small
615     improvement to matching performance by compiling OP_ALLANY instead of
616     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
617     on the OP_ANY path.
618    
619     17. Compiling pcretest on Windows with readline support failed without the
620 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
621 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
622    
623 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
624 ph10 345 ncurses library to be included for pcretest when ReadLine support is
625     requested, but also to allow for it to be overridden. This patch came from
626     Daniel Bergström.
627 ph10 347
628 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
629 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
630     any errors with the current Unicode tables. Thanks to Peter Kankowski for
631     spotting this.
632 ph10 324
633 ph10 332
634 ph10 319 Version 7.6 28-Jan-08
635 ph10 300 ---------------------
636    
637 ph10 302 1. A character class containing a very large number of characters with
638     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
639     overflow.
640 ph10 309
641     2. Patch to cut out the "long long" test in pcrecpp_unittest when
642     HAVE_LONG_LONG is not defined.
643    
644 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
645 ph10 304 bring them up to date and include new features. This patch includes:
646 ph10 309
647 ph10 304 - Fixed PH's badly added libz and libbz2 support.
648     - Fixed a problem with static linking.
649 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
650 ph10 304 - Fixed dftables problem and added an option.
651     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
652     HAVE_LONG_LONG.
653     - Added readline support for pcretest.
654 ph10 309 - Added an listing of the option settings after cmake has run.
655    
656 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
657     "pcre.dll" under mingw when using Configure/Make. I added stuff to
658     Makefile.am that cause it to include this special target, without
659     affecting anything else. Note that the same mingw target plus all
660     the other distribution libraries and programs are now supported
661     when configuring with CMake (see 6 below) instead of with
662     Configure/Make.
663 ph10 309
664 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
665     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
666 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
667     solves the problem, but it does no harm.
668 ph10 313
669 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
670 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
671 ph10 314 with CMake, and also correct the comment about stack recursion.
672 ph10 313
673 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
674 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
675     of a program that users should build themselves after PCRE is installed, so
676     building it automatically is not really right. What is more, it gave
677 ph10 312 trouble in some build environments.
678 ph10 300
679 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
680 ph10 308
681 ph10 319
682 ph10 298 Version 7.5 10-Jan-08
683 ph10 263 ---------------------
684    
685     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
686     values in parens when parsing an RE using the C++ wrapper."
687 ph10 286
688 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
689     Characters greater than 255 were excluded from the class instead of being
690     included.
691 ph10 286
692     3. The same bug as (2) above applied to negated POSIX classes such as
693 ph10 265 [:^space:].
694 ph10 286
695 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
696     defined or documented. It seems to have been a typo for PCRE_STATIC, so
697 ph10 286 I have changed it.
698    
699 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
700 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
701     first named subpattern whose name started with "a" (in other words, the
702 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
703     expected" is now given for (?&) (a zero-length name), and this patch also
704     makes it give the same error for \k'' (previously it complained that that
705     was a reference to a non-existent subpattern).
706 ph10 286
707 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
708 ph10 286 this is right because (?- can be followed by option settings as well as by
709 ph10 269 digits. I have, however, made the messages clearer.
710 ph10 286
711 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
712     than the number used in the conditional) now cause a compile-time error.
713     This is actually not compatible with Perl, which accepts such patterns, but
714     treats the conditional as always being FALSE (as PCRE used to), but it
715     seems to me that giving a diagnostic is better.
716 ph10 286
717 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
718 ph10 275 and messages.
719 ph10 286
720     9. Fix two occurrences of "backslash" in comments that should have been
721     "backspace".
722    
723     10. Remove two redundant lines of code that can never be obeyed (their function
724     was moved elsewhere).
725    
726     11. The program that makes PCRE's Unicode character property table had a bug
727     which caused it to generate incorrect table entries for sequences of
728 ph10 277 characters that have the same character type, but are in different scripts.
729 ph10 286 It amalgamated them into a single range, with the script of the first of
730 ph10 277 them. In other words, some characters were in the wrong script. There were
731     thirteen such cases, affecting characters in the following ranges:
732 ph10 286
733 ph10 277 U+002b0 - U+002c1
734     U+0060c - U+0060d
735 ph10 286 U+0061e - U+00612
736 ph10 277 U+0064b - U+0065e
737     U+0074d - U+0076d
738     U+01800 - U+01805
739     U+01d00 - U+01d77
740     U+01d9b - U+01dbf
741     U+0200b - U+0200f
742     U+030fc - U+030fe
743     U+03260 - U+0327f
744     U+0fb46 - U+0fbb1
745     U+10450 - U+1049d
746 ph10 286
747 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
748     compatible with GNU grep in that, if there was more than one match in a
749     line, it showed only the first of them. It now behaves in the same way as
750     GNU grep.
751 ph10 286
752     13. If the -o and -v options were combined for pcregrep, it printed a blank
753     line for every non-matching line. GNU grep prints nothing, and pcregrep now
754     does the same. The return code can be used to tell if there were any
755     non-matching lines.
756    
757 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
758    
759     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
760 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
761 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
762     and both kinds of lookbehind were skipped).
763    
764 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
765 ph10 284 inclusion of <windows.h> to before rather than after the definition of
766     INVALID_FILE_ATTRIBUTES (patch from David Byron).
767 ph10 263
768 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
769 ph10 286 character property caused pcre_compile() to compile bad code, which led at
770     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
771     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
772     caused the error; without that there was no problem.
773 ph10 263
774 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
775 ph10 286
776 ph10 289 19. Added --enable-pcretest-libreadline.
777 ph10 286
778 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
779 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
780 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
781     later patch that removed the other one (the right fix) and added unit tests
782     that check the return values (which was not done before).
783 ph10 292
784 ph10 291 21. Several CMake things:
785 ph10 287
786 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
787 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
788 ph10 288
789 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
790     linked with the newly-built libraries, not previously installed ones.
791 ph10 291
792 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
793 ph10 298
794     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
795     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
796     UTF-8 newline character). The key issue is that the pattern starts .*;
797     this means that the match must be either at the beginning, or after a
798     newline. The bug was in the code for advancing after a failed match and
799     checking that the new position followed a newline. It was not taking
800 ph10 294 account of UTF-8 characters correctly.
801 ph10 298
802     23. PCRE was behaving differently from Perl in the way it recognized POSIX
803     character classes. PCRE was not treating the sequence [:...:] as a
804     character class unless the ... were all letters. Perl, however, seems to
805     allow any characters between [: and :], though of course it rejects as
806     unknown any "names" that contain non-letters, because all the known class
807     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
808     for example, whereas PCRE did not - it did not recognize a POSIX character
809     class. This seemed a bit dangerous, so the code has been changed to be
810     closer to Perl. The behaviour is not identical to Perl, because PCRE will
811     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
812     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
813     Perl does, and where it didn't before.
814    
815 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
816     Windows environments %n is disabled by default.
817 ph10 292
818    
819 ph10 260 Version 7.4 21-Sep-07
820 ph10 230 ---------------------
821    
822     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
823 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
824     LF". That isn't really right - the whole point of the change was to try to
825     help when there was an actual mention of one of the two characters. So now
826     the change happens only if \r or \n (or a literal CR or LF) character is
827 ph10 230 encountered.
828 ph10 231
829     2. The 32-bit options word was also used for 6 internal flags, but the numbers
830     of both had grown to the point where there were only 3 bits left.
831     Fortunately, there was spare space in the data structure, and so I have
832     moved the internal flags into a new 16-bit field to free up more option
833 ph10 230 bits.
834 ph10 231
835     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
836     but did not set the internal JCHANGED flag - either of these is enough to
837     control the way the "get" function works - but the PCRE_INFO_JCHANGED
838     facility is supposed to tell if (?J) was ever used, so now (?J) at the
839 ph10 230 start sets both bits.
840    
841 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
842     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
843 ph10 230
844 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
845    
846     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
847 ph10 233 compatibility, even though it is no longer used.
848 ph10 243
849     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
850 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
851 ph10 259 windows.h file is present (where different names are used). [This was
852 ph10 257 reversed later after testing - see 16 below.]
853 ph10 243
854     8. Changed all #include <config.h> to #include "config.h". There were also
855 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
856 ph10 243
857 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
858 ph10 243 sequence off the lines that it output.
859    
860     10. It was pointed out to me that arrays of string pointers cause lots of
861     relocations when a shared library is dynamically loaded. A technique of
862     using a single long string with a table of offsets can drastically reduce
863     these. I have refactored PCRE in four places to do this. The result is
864 ph10 240 dramatic:
865 ph10 243
866 ph10 240 Originally: 290
867     After changing UCP table: 187
868 ph10 243 After changing error message table: 43
869 ph10 240 After changing table of "verbs" 36
870     After changing table of Posix names 22
871 ph10 243
872 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
873 ph10 247
874 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
875 ph10 247 unicode-properties was also set.
876    
877 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
878 ph10 231
879 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
880     checked only for CRLF.
881 ph10 233
882 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
883    
884 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
885 ph10 253
886 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
887 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
888     entirely. This removes changes made in 7 above.
889 ph10 256
890 ph10 261 17. The CMake files have been updated, and there is now more information about
891     building with CMake in the NON-UNIX-USE document.
892 ph10 257
893 ph10 261
894 ph10 228 Version 7.3 28-Aug-07
895 ph10 157 ---------------------
896    
897 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
898     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
899     brackets there is not right, since it causes compilers to look for an
900     installed pcre.h, not the version that is in the source that is being
901     compiled (which of course may be different). I have changed it back to:
902 ph10 197
903 ph10 189 #include "pcre.h"
904 ph10 197
905     I have a vague recollection that the change was concerned with compiling in
906     different directories, but in the new build system, that is taken care of
907     by the VPATH setting the Makefile.
908    
909 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
910     when the subject happened to end in the byte 0x85 (e.g. if the last
911     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
912     characters but of course it shouldn't be taken as a newline when it is part
913     of another character. The bug was that, for an unlimited repeat of . in
914     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
915     characters when looking for a newline.
916 ph10 197
917     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
918    
919     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
920     in debug output.
921    
922 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
923     long printing in the pcrecpp unittest when running under MinGW.
924 ph10 189
925 ph10 197 6. ESC_K was left out of the EBCDIC table.
926 ph10 189
927 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
928     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
929     limit also applies to "virtual nesting" when a pattern is recursive, and in
930     this case 1000 isn't so big. I have been able to remove this limit at the
931     expense of backing off one optimization in certain circumstances. Normally,
932     when pcre_exec() would call its internal match() function recursively and
933     immediately return the result unconditionally, it uses a "tail recursion"
934     feature to save stack. However, when a subpattern that can match an empty
935     string has an unlimited repetition quantifier, it no longer makes this
936     optimization. That gives it a stack frame in which to save the data for
937     checking that an empty string has been matched. Previously this was taken
938     from the 1000-entry workspace that had been reserved. So now there is no
939     explicit limit, but more stack is used.
940 ph10 189
941 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
942     syntax that is required for Windows, and which was going wrong for the
943     pcreposix and pcrecpp parts of the library. These were overlooked when this
944     problem was solved for the main library.
945 ph10 197
946 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
947     the size of patterns that contain repeated groups with explicit upper
948     limits. As the maximum quantifier is 65535, the maximum group length was
949     set at 30,000 so that the product of these two numbers did not overflow a
950     32-bit integer. However, it turns out that people want to use groups that
951     are longer than 30,000 bytes (though not repeat them that many times).
952     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
953     made it possible to implement the integer overflow checks in a much more
954     dynamic way, which I have now done. The artificial limitation on group
955     length has been removed - we now have only the limit on the total length of
956     the compiled pattern, which depends on the LINK_SIZE setting.
957 ph10 208
958     10. Fixed a bug in the documentation for get/copy named substring when
959     duplicate names are permitted. If none of the named substrings are set, the
960     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
961     empty string.
962    
963     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
964     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
965     because the ] is interpreted as the first data character and the
966     terminating ] is not found. PCRE has been made compatible with Perl in this
967     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
968     cause memory overwriting.
969    
970 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
971     string has been matched (to stop an infinite loop). It was not recognizing
972 ph10 208 a conditional subpattern that could match an empty string if that
973 ph10 206 subpattern was within another subpattern. For example, it looped when
974 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
975 ph10 206 condition was not nested. This bug has been fixed.
976 ph10 208
977 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
978     past the start of the subject in the presence of bytes with the top bit
979     set, for example "\x8aBCD".
980 ph10 211
981 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
982     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
983 ph10 200
984 ph10 211 14. Optimized (?!) to (*FAIL).
985 ph10 202
986 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
987     This restricts code points to be within the range 0 to 0x10FFFF, excluding
988     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
989     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
990     does: it's just the validity check that is more restrictive.
991 ph10 220
992     16. Inserted checks for integer overflows during escape sequence (backslash)
993     processing, and also fixed erroneous offset values for syntax errors during
994     backslash processing.
995    
996 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
997 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
998    
999 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1000     caused an overrun.
1001 ph10 220
1002     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1003     something other than just ASCII characters) inside a group that had an
1004     unlimited repeat caused a loop at compile time (while checking to see
1005     whether the group could match an empty string).
1006    
1007 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1008     [\P{Any}] did so. (Error in the code for printing property names.)
1009 ph10 210
1010 ph10 220 21. An orphan \E inside a character class could cause a crash.
1011    
1012     22. A repeated capturing bracket such as (A)? could cause a wild memory
1013 ph10 218 reference during compilation.
1014 ph10 220
1015     23. There are several functions in pcre_compile() that scan along a compiled
1016     expression for various reasons (e.g. to see if it's fixed length for look
1017 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
1018 ph10 220 present in the pattern. These operators have additional parameters compared
1019     with \d, etc, and these were not being taken into account when moving along
1020 ph10 218 the compiled data. Specifically:
1021 ph10 220
1022     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1023     length.
1024    
1025     (b) An item such as \pL+ within a repeated group could cause crashes or
1026 ph10 218 loops.
1027 ph10 220
1028 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1029 ph10 220 "reference to non-existent subpattern" error.
1030    
1031 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1032    
1033 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1034 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1035 ph10 211
1036 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1037 ph10 218
1038 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1039 ph10 223 character were causing crashes (broken optimization).
1040 ph10 227
1041 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1042 ph10 227 \p or \P) caused a compile-time loop.
1043    
1044 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1045     break. For example, the unstudied pattern [\r\n]A does not match the string
1046     "\r\nA" because change 7.0/46 below moves the current point on by two
1047     characters after failing to match at the start. However, the pattern \nA
1048 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1049     the same is true. There doesn't seem any very clean way out of this, but
1050     what I have chosen to do makes the common cases work: PCRE now takes note
1051     of whether there can be an explicit match for \r or \n anywhere in the
1052     pattern, and if so, 7.0/46 no longer applies. As part of this change,
1053     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1054     pattern has explicit CR or LF references.
1055 ph10 222
1056 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
1057 ph10 223
1058 ph10 227
1059 ph10 189 Version 7.2 19-Jun-07
1060     ---------------------
1061    
1062 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1063     which is apparently normally available under Windows.
1064 ph10 159
1065     2. Re-jig the pcregrep tests with different newline settings in an attempt
1066     to make them independent of the local environment's newline setting.
1067 ph10 157
1068 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1069 ph10 165
1070 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
1071     was not 2, because the output contained actual offsets. The recent new
1072 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
1073     usable with all link sizes.
1074    
1075 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1076     stack recursion. This gives a massive performance boost under BSD, but just
1077 ph10 165 a small improvement under Linux. However, it saves one field in the frame
1078 ph10 164 in all cases.
1079 ph10 172
1080 ph10 166 6. Added more features from the forthcoming Perl 5.10:
1081 ph10 172
1082 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1083     recursion call. It refers to the nth most recently opened parentheses.
1084 ph10 172
1085 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1086 ph10 172 to be opened parentheses.
1087    
1088     (c) Conditions that refer to capturing parentheses can be specified
1089 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
1090 ph10 172
1091 ph10 168 (d) \K resets the start of the current match so that everything before
1092 ph10 172 is not part of it.
1093    
1094 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1095 ph10 172
1096 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1097 ph10 172 reference syntax.
1098 ph10 182
1099 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
1100 ph10 182 alternative starts with the same number.
1101 ph10 172
1102 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1103    
1104 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1105     PCRE_INFO_JCHANGED.
1106    
1107     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1108     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1109 ph10 170 for detecting groups that can match an empty string.
1110 ph10 159
1111 ph10 172 9. A pattern with a very large number of alternatives (more than several
1112     hundred) was running out of internal workspace during the pre-compile
1113     phase, where pcre_compile() figures out how much memory will be needed. A
1114     bit of new cunning has reduced the workspace needed for groups with
1115     alternatives. The 1000-alternative test pattern now uses 12 bytes of
1116     workspace instead of running out of the 4096 that are available.
1117 ph10 182
1118 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1119 ph10 172
1120 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
1121     The report of the bug said:
1122 ph10 182
1123 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1124     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1125 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1126 ph10 185
1127 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1128 ph10 185 it matched the wrong number of bytes.
1129 ph10 172
1130 ph10 179
1131 ph10 155 Version 7.1 24-Apr-07
1132 ph10 98 ---------------------
1133    
1134 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1135 ph10 122 that is more "standard", making use of automake and other Autotools. There
1136 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
1137     on this.
1138 ph10 111
1139     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1140     for recursive directory scanning broke on some systems because the files
1141     are not scanned in any specific order and on different systems the order
1142     was different. A call to "sort" has been inserted into RunGrepTest for the
1143     approprate test as a short-term fix. In the longer term there may be an
1144 ph10 100 alternative.
1145 ph10 111
1146 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
1147 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
1148     people do their own conversions for various reasons). The problems
1149     concerned the use of low-level troff macros .br and .in. I have therefore
1150     removed all such uses from the man pages (some were redundant, some could
1151 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1152     HTML has been updated to handle .nf/.fi and to complain if it encounters
1153     .br or .in.
1154 ph10 111
1155 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
1156 ph10 123 arranged for config.h to be included in the distribution, with the name
1157 ph10 111 config.h.generic, for the benefit of those who have to compile without
1158     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1159    
1160     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1161     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1162 ph10 127 makevp.bat for the current PCRE, using the additional files
1163 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1164 ph10 111
1165     6. A Windows user reported a minor discrepancy with test 2, which turned out
1166     to be caused by a trailing space on an input line that had got lost in his
1167 ph10 102 copy. The trailing space was an accident, so I've just removed it.
1168 ph10 111
1169 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1170 ph10 111 that is needed.
1171    
1172 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1173     as "const" (a) because they are and (b) because it helps the PHP
1174     maintainers who have recently made a script to detect big data structures
1175 ph10 111 in the php code that should be moved to the .rodata section. I remembered
1176     to update Builducptable as well, so it won't revert if ucptable.h is ever
1177 ph10 105 re-created.
1178 ph10 111
1179     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1180 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1181 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1182     support is not required. This saves 1.5-2K of code, which is important in
1183 ph10 107 some applications.
1184 ph10 111
1185 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1186 ph10 111 so as not to refer to the tables, even though these functions will never be
1187     called when UTF-8 support is disabled. Otherwise there are problems with a
1188     shared library.
1189    
1190 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1191    
1192     (a) It was defining its arguments as char * instead of void *.
1193    
1194 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
1195     a long time ago when I wrote it, but is no longer the case.
1196    
1197 ph10 118 The emulated memove() is provided for those environments that have neither
1198 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1199 ph10 118 is clearly not the case, as these two bugs were recently reported.
1200 ph10 123
1201 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1202 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
1203     pages, and it removes trailing spaces from listed files. It also creates
1204     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1205     case, it wraps all the #defines with #ifndefs. This script should be run
1206 ph10 111 before "make dist".
1207 ph10 123
1208 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1209     with Unicode property support.
1210 ph10 123
1211     (a) For a maximizing quantifier, if the two different cases of the
1212     character were of different lengths in their UTF-8 codings (there are
1213     some cases like this - I found 11), and the matching function had to
1214 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
1215     were both the same length.
1216 ph10 123
1217     (b) When PCRE was configured to use the heap rather than the stack for
1218     recursion during matching, it was not correctly preserving the data for
1219     the other case of a UTF-8 character when checking ahead for a match
1220     while processing a minimizing repeat. If the check also involved
1221 ph10 115 matching a wide character, but failed, corruption could cause an
1222     erroneous result when trying to check for a repeat of the original
1223     character.
1224 ph10 123
1225 ph10 116 13. Some tidying changes to the testing mechanism:
1226 ph10 98
1227 ph10 116 (a) The RunTest script now detects the internal link size and whether there
1228     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1229 ph10 123 values substituted by "configure". (The RunGrepTest script already did
1230     this for UTF-8.) The configure.ac script no longer substitutes the
1231     relevant variables.
1232    
1233 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1234     with length and offset values. This means that the output is different
1235     for different internal link sizes. Test 2 is skipped for link sizes
1236     other than 2 because of this, bypassing the problem. Unfortunately,
1237     there was also a test in test 3 (the locale tests) that used /B and
1238 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
1239     I have added a new /Z option to pcretest that replaces the length and
1240     offset values with spaces. This is now used to make test 3 independent
1241 ph10 122 of link size. (Test 2 will be tidied up later.)
1242 ph10 123
1243     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1244 ph10 122 segmentation fault instead of returning the appropriate error message.
1245 ph10 134
1246 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
1247 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1248     This doesn't seem right; it now treats the CRLF combination as the line
1249     ending, and so does not match in that case. It's only a pattern such as ^$
1250     that would hit this one: something like ^ABC$ would have failed after \r
1251     and then tried again after \r\n.
1252    
1253 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1254 ph10 134 in an attempt to make files that differ only in their line terminators
1255     compare equal. This works on Linux.
1256 ph10 142
1257 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
1258     as it exited. This is now fixed, thanks to valgrind.
1259 ph10 142
1260 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1261 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1262     was because its rules for how to advance for /g after matching an empty
1263 ph10 143 string at the end of a line did not allow for this case. They now check for
1264     it specially.
1265 ph10 150
1266     20. pcretest is supposed to handle patterns and data of any length, by
1267     extending its buffers when necessary. It was getting this wrong when the
1268 ph10 147 buffer for a data line had to be extended.
1269 ph10 150
1270 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1271 ph10 150 CRLF as a newline sequence.
1272 ph10 152
1273 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1274 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1275     I have nevertheless tidied it up.
1276 ph10 111
1277 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1278 ph10 123
1279 ph10 153 24. Added a man page for pcre-config.
1280 ph10 152
1281 ph10 153
1282 nigel 93 Version 7.0 19-Dec-06
1283     ---------------------
1284    
1285     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1286     moving to gcc 4.1.1.
1287    
1288     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1289     sys/time.h, which is documented as needed for this function. It doesn't
1290     seem to matter on Linux, but it showed up on some releases of OS X.
1291    
1292     3. It seems that there are systems where bytes whose values are greater than
1293     127 match isprint() in the "C" locale. The "C" locale should be the
1294     default when a C program starts up. In most systems, only ASCII printing
1295     characters match isprint(). This difference caused the output from pcretest
1296     to vary, making some of the tests fail. I have changed pcretest so that:
1297    
1298     (a) When it is outputting text in the compiled version of a pattern, bytes
1299     other than 32-126 are always shown as hex escapes.
1300    
1301     (b) When it is outputting text that is a matched part of a subject string,
1302     it does the same, unless a different locale has been set for the match
1303     (using the /L modifier). In this case, it uses isprint() to decide.
1304    
1305     4. Fixed a major bug that caused incorrect computation of the amount of memory
1306     required for a compiled pattern when options that changed within the
1307     pattern affected the logic of the preliminary scan that determines the
1308     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1309     that the computed length was too small. The symptoms of this bug were
1310     either the PCRE error "internal error: code overflow" from pcre_compile(),
1311     or a glibc crash with a message such as "pcretest: free(): invalid next
1312     size (fast)". Examples of patterns that provoked this bug (shown in
1313     pcretest format) are:
1314    
1315     /(?-x: )/x
1316     /(?x)(?-x: \s*#\s*)/
1317     /((?i)[\x{c0}])/8
1318     /(?i:[\x{c0}])/8
1319    
1320     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1321     is now done differently.
1322    
1323     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1324     wrapper classes; (b) implement a new function in the C++ scanner that is
1325     more efficient than the old way of doing things because it avoids levels of
1326     recursion in the regex matching; (c) add a paragraph to the documentation
1327     for the FullMatch() function.
1328    
1329     6. The escape sequence \n was being treated as whatever was defined as
1330     "newline". Not only was this contrary to the documentation, which states
1331     that \n is character 10 (hex 0A), but it also went horribly wrong when
1332     "newline" was defined as CRLF. This has been fixed.
1333    
1334     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1335     was being set to -1 for the "end of line" case (supposedly a value that no
1336     character can have). Though this value is never used (the check for end of
1337     line is "zero bytes in current character"), it caused compiler complaints.
1338     I've changed it to 0xffffffff.
1339    
1340     8. In pcre_version.c, the version string was being built by a sequence of
1341     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1342     string (as it is for production releases) called a macro with an empty
1343     argument. The C standard says the result of this is undefined. The gcc
1344     compiler treats it as an empty string (which was what was wanted) but it is
1345     reported that Visual C gives an error. The source has been hacked around to
1346     avoid this problem.
1347    
1348     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1349     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1350     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1351     of them did).
1352    
1353     10. Originally, pcretest opened its input and output without "b"; then I was
1354     told that "b" was needed in some environments, so it was added for release
1355     5.0 to both the input and output. (It makes no difference on Unix-like
1356     systems.) Later I was told that it is wrong for the input on Windows. I've
1357     now abstracted the modes into two macros, to make it easier to fiddle with
1358     them, and removed "b" from the input mode under Windows.
1359    
1360     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1361    
1362     12. Added -help and --help to pcretest as an official way of being reminded
1363     of the options.
1364    
1365     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1366     and pcrecpp.cc because they annoy compilers at high warning levels.
1367    
1368     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1369    
1370     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1371     scripts are not C programs :-) and which was not noticed because it works
1372     on Linux.
1373    
1374     16. pcretest is supposed to handle any length of pattern and data line (as one
1375     line or as a continued sequence of lines) by extending its input buffer if
1376     necessary. This feature was broken for very long pattern lines, leading to
1377     a string of junk being passed to pcre_compile() if the pattern was longer
1378     than about 50K.
1379    
1380     17. I have done a major re-factoring of the way pcre_compile() computes the
1381     amount of memory needed for a compiled pattern. Previously, there was code
1382     that made a preliminary scan of the pattern in order to do this. That was
1383     OK when PCRE was new, but as the facilities have expanded, it has become
1384     harder and harder to keep it in step with the real compile phase, and there
1385     have been a number of bugs (see for example, 4 above). I have now found a
1386     cunning way of running the real compile function in a "fake" mode that
1387     enables it to compute how much memory it would need, while actually only
1388     ever using a few hundred bytes of working memory and without too many
1389     tests of the mode. This should make future maintenance and development
1390     easier. A side effect of this work is that the limit of 200 on the nesting
1391     depth of parentheses has been removed (though this was never a serious
1392     limitation, I suspect). However, there is a downside: pcre_compile() now
1393     runs more slowly than before (30% or more, depending on the pattern). I
1394     hope this isn't a big issue. There is no effect on runtime performance.
1395    
1396     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1397     newline (only possible for the last line of a file) and it was a
1398     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1399    
1400     19. Added additional timing features to pcretest. (1) The -tm option now times
1401     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1402     separate command line item, by a number that specifies the number of
1403     repeats to use when timing. The default is 50000; this gives better
1404     precision, but takes uncomfortably long for very large patterns.
1405    
1406     20. Extended pcre_study() to be more clever in cases where a branch of a
1407     subpattern has no definite first character. For example, (a*|b*)[cd] would
1408     previously give no result from pcre_study(). Now it recognizes that the
1409     first character must be a, b, c, or d.
1410    
1411     21. There was an incorrect error "recursive call could loop indefinitely" if
1412     a subpattern (or the entire pattern) that was being tested for matching an
1413     empty string contained only one non-empty item after a nested subpattern.
1414     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1415     incorrectly, because the \d was being skipped in the check.
1416    
1417     22. The pcretest program now has a new pattern option /B and a command line
1418     option -b, which is equivalent to adding /B to every pattern. This causes
1419     it to show the compiled bytecode, without the additional information that
1420     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1421     is the same as /B/I).
1422    
1423     23. A new optimization is now able automatically to treat some sequences such
1424     as a*b as a*+b. More specifically, if something simple (such as a character
1425     or a simple class like \d) has an unlimited quantifier, and is followed by
1426     something that cannot possibly match the quantified thing, the quantifier
1427     is automatically "possessified".
1428    
1429     24. A recursive reference to a subpattern whose number was greater than 39
1430     went wrong under certain circumstances in UTF-8 mode. This bug could also
1431     have affected the operation of pcre_study().
1432    
1433     25. Realized that a little bit of performance could be had by replacing
1434     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1435    
1436     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1437    
1438     27. Possessive quantifiers such as a++ were previously implemented by turning
1439     them into atomic groups such as ($>a+). Now they have their own opcodes,
1440     which improves performance. This includes the automatically created ones
1441     from 23 above.
1442    
1443     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1444     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1445     the first matched character to be a colon. This applied both to named and
1446     numbered groups.
1447    
1448     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1449    
1450     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1451     building PCRE on Windows easier, so I have included it in the distribution.
1452    
1453     31. There is now a check in pcretest against a ridiculously large number being
1454     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1455     loop, the loop is abandoned.
1456    
1457     32. Forward references to subpatterns in conditions such as (?(2)...) where
1458     subpattern 2 is defined later cause pcre_compile() to search forwards in
1459     the pattern for the relevant set of parentheses. This search went wrong
1460     when there were unescaped parentheses in a character class, parentheses
1461     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1462    
1463     33. "Subroutine" calls and backreferences were previously restricted to
1464     referencing subpatterns earlier in the regex. This restriction has now
1465     been removed.
1466    
1467     34. Added a number of extra features that are going to be in Perl 5.10. On the
1468     whole, these are just syntactic alternatives for features that PCRE had
1469     previously implemented using the Python syntax or my own invention. The
1470     other formats are all retained for compatibility.
1471    
1472     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1473     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1474     also .NET compatible.
1475    
1476     (b) A recursion or subroutine call to a named group can now be defined as
1477     (?&name) as well as (?P>name).
1478    
1479     (c) A backreference to a named group can now be defined as \k<name> or
1480     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1481     5.10, are also .NET compatible.
1482    
1483     (d) A conditional reference to a named group can now use the syntax
1484     (?(<name>) or (?('name') as well as (?(name).
1485    
1486     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1487     groups (named and numbered) that are never evaluated inline, but can be
1488     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1489     is always false. There may be only one alternative in such a group.
1490    
1491     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1492     as the simple (?(R). The condition is true only if the most recent
1493     recursion is that of the given number or name. It does not search out
1494     through the entire recursion stack.
1495    
1496     (g) The escape \gN or \g{N} has been added, where N is a positive or
1497     negative number, specifying an absolute or relative reference.
1498    
1499     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1500     some "unreachable code" warnings.
1501    
1502     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1503     things, this adds five new scripts.
1504    
1505     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1506     There were also incompatibilities regarding the handling of \Q..\E inside
1507     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1508     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1509    
1510     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1511     matches an empty string, and forcibly breaks the loop. There were bugs in
1512     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1513     against aaaa the result was just "a" rather than "aaaa", for example. Two
1514     separate and independent bugs (that affected different cases) have been
1515     fixed.
1516    
1517     39. Refactored the code to abolish the use of different opcodes for small
1518     capturing bracket numbers. This is a tidy that I avoided doing when I
1519     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1520     The new approach is not only tidier, it makes it possible to reduce the
1521     memory needed to fix the previous bug (38).
1522    
1523     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1524     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1525     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1526     mode.
1527    
1528     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1529     report.
1530    
1531     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1532     copy construction and assignment in the C++ wrapper.
1533    
1534     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1535     couple of bugs that could have given wrong results in the "--newline=crlf"
1536     case.
1537    
1538     44. Added a number of casts and did some reorganization of signed/unsigned int
1539     variables following suggestions from Dair Grant. Also renamed the variable
1540     "this" as "item" because it is a C++ keyword.
1541    
1542     45. Arranged for dftables to add
1543    
1544     #include "pcre_internal.h"
1545    
1546     to pcre_chartables.c because without it, gcc 4.x may remove the array
1547     definition from the final binary if PCRE is built into a static library and
1548     dead code stripping is activated.
1549    
1550     46. For an unanchored pattern, if a match attempt fails at the start of a
1551     newline sequence, and the newline setting is CRLF or ANY, and the next two
1552     characters are CRLF, advance by two characters instead of one.
1553    
1554    
1555 nigel 91 Version 6.7 04-Jul-06
1556     ---------------------
1557    
1558     1. In order to handle tests when input lines are enormously long, pcretest has
1559     been re-factored so that it automatically extends its buffers when
1560     necessary. The code is crude, but this _is_ just a test program. The
1561     default size has been increased from 32K to 50K.
1562    
1563     2. The code in pcre_study() was using the value of the re argument before
1564     testing it for NULL. (Of course, in any sensible call of the function, it
1565     won't be NULL.)
1566    
1567     3. The memmove() emulation function in pcre_internal.h, which is used on
1568     systems that lack both memmove() and bcopy() - that is, hardly ever -
1569     was missing a "static" storage class specifier.
1570    
1571     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1572     containing an extended class (one that cannot be represented by a bitmap
1573     because it contains high-valued characters or Unicode property items, e.g.
1574     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1575     pattern, but PCRE should not loop if you do not (it no longer does).
1576     [Detail: two cases were found: (a) a repeated subpattern containing an
1577     extended class; (b) a recursive reference to a subpattern that followed a
1578     previous extended class. It wasn't skipping over the extended class
1579     correctly when UTF-8 mode was not set.]
1580    
1581     5. A negated single-character class was not being recognized as fixed-length
1582     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1583     compile error "lookbehind assertion is not fixed length".
1584    
1585     6. The RunPerlTest auxiliary script was showing an unexpected difference
1586     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1587     write a Perl script that can interpret lines of an input file either as
1588     byte characters or as UTF-8, which is what "perltest" was being required to
1589     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1590     can't do is switch easily at run time between having the "use utf8;" pragma
1591     or not. In the end, I fudged it by using the RunPerlTest script to insert
1592     "use utf8;" explicitly for the UTF-8 tests.
1593    
1594     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1595     the end of the subject string, contrary to the documentation and to what
1596     Perl does. This was true of both matching functions. Now it matches only at
1597     the start of the subject and immediately after *internal* newlines.
1598    
1599     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1600     a pointer to an int instead of a pointer to an unsigned long int. This
1601     caused problems on 64-bit systems.
1602    
1603     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1604     instance of the 'standard' template library not being so standard".
1605    
1606     10. There was no check on the number of named subpatterns nor the maximum
1607     length of a subpattern name. The product of these values is used to compute
1608     the size of the memory block for a compiled pattern. By supplying a very
1609     long subpattern name and a large number of named subpatterns, the size
1610     computation could be caused to overflow. This is now prevented by limiting
1611     the length of names to 32 characters, and the number of named subpatterns
1612     to 10,000.
1613    
1614     11. Subpatterns that are repeated with specific counts have to be replicated in
1615     the compiled pattern. The size of memory for this was computed from the
1616     length of the subpattern and the repeat count. The latter is limited to
1617     65535, but there was no limit on the former, meaning that integer overflow
1618     could in principle occur. The compiled length of a repeated subpattern is
1619     now limited to 30,000 bytes in order to prevent this.
1620    
1621     12. Added the optional facility to have named substrings with the same name.
1622    
1623     13. Added the ability to use a named substring as a condition, using the
1624     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1625     are numbers (not recommended). Forward references are permitted.
1626    
1627     14. Added forward references in named backreferences (if you see what I mean).
1628    
1629     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1630     pattern could run off the end of the subject. For example, the pattern
1631     "(?s)(.{1,5})"8 did this with the subject "ab".
1632    
1633     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1634     PCRE_CASELESS was set when matching characters that were quantified with ?
1635     or *.
1636    
1637     17. A character class other than a single negated character that had a minimum
1638     but no maximum quantifier - for example [ab]{6,} - was not handled
1639     correctly by pce_dfa_exec(). It would match only one character.
1640    
1641     18. A valid (though odd) pattern that looked like a POSIX character
1642     class but used an invalid character after [ (for example [[,abc,]]) caused
1643     pcre_compile() to give the error "Failed: internal error: code overflow" or
1644     in some cases to crash with a glibc free() error. This could even happen if
1645     the pattern terminated after [[ but there just happened to be a sequence of
1646     letters, a binary zero, and a closing ] in the memory that followed.
1647    
1648     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1649     over the years. Originally (before any Unicode support), just the bottom 8
1650     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1651     output from "man perlunicode" includes this:
1652    
1653     The regular expression compiler produces polymorphic opcodes. That
1654     is, the pattern adapts to the data and automatically switches to
1655     the Unicode character scheme when presented with Unicode data--or
1656     instead uses a traditional byte scheme when presented with byte
1657     data.
1658    
1659     Sadly, a wide octal escape does not cause a switch, and in a string with
1660     no other multibyte characters, these octal escapes are treated as before.
1661     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1662     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1663     Unicode string.
1664    
1665     I have not perpetrated such confusion in PCRE. Up till now, it took just
1666     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1667     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1668     translate to the appropriate multibyte character.
1669    
1670     29. Applied some refactoring to reduce the number of warnings from Microsoft
1671     and Borland compilers. This has included removing the fudge introduced
1672     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1673     a warning about an unused variable.
1674    
1675     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1676     characters since release 4.0, because Perl (from release 5.004) does not.
1677     [Or at least, is documented not to: some releases seem to be in conflict
1678     with the documentation.] However, when a pattern was studied with
1679     pcre_study() and all its branches started with \s, PCRE still included VT
1680     as a possible starting character. Of course, this did no harm; it just
1681     caused an unnecessary match attempt.
1682    
1683     22. Removed a now-redundant internal flag bit that recorded the fact that case
1684     dependency changed within the pattern. This was once needed for "required
1685     byte" processing, but is no longer used. This recovers a now-scarce options
1686     bit. Also moved the least significant internal flag bit to the most-
1687     significant bit of the word, which was not previously used (hangover from
1688     the days when it was an int rather than a uint) to free up another bit for
1689     the future.
1690    
1691     23. Added support for CRLF line endings as well as CR and LF. As well as the
1692     default being selectable at build time, it can now be changed at runtime
1693     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1694     specify that it is scanning data with non-default line endings.
1695    
1696     24. Changed the definition of CXXLINK to make it agree with the definition of
1697     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1698    
1699     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1700     recursions. This makes a big different to stack usage for some patterns.
1701    
1702     26. If a subpattern containing a named recursion or subroutine reference such
1703     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1704     the space required for the compiled pattern went wrong and gave too small a
1705     value. Depending on the environment, this could lead to "Failed: internal
1706     error: code overflow at offset 49" or "glibc detected double free or
1707     corruption" errors.
1708    
1709     27. Applied patches from Google (a) to support the new newline modes and (b) to
1710     advance over multibyte UTF-8 characters in GlobalReplace.
1711    
1712     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1713     difference for some implementation of PCRE in some Windows version.
1714    
1715     29. Added some extra testing facilities to pcretest:
1716    
1717     \q<number> in a data line sets the "match limit" value
1718     \Q<number> in a data line sets the "match recursion limt" value
1719     -S <number> sets the stack size, where <number> is in megabytes
1720    
1721     The -S option isn't available for Windows.
1722    
1723    
1724 nigel 89 Version 6.6 06-Feb-06
1725     ---------------------
1726    
1727     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1728     in pcreposix.h. I have copied the definition from pcre.h.
1729    
1730     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1731     because pcre.h is no longer a built file.
1732    
1733     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1734     not normally included in the compiled code.
1735    
1736    
1737 nigel 87 Version 6.5 01-Feb-06
1738     ---------------------
1739    
1740     1. When using the partial match feature with pcre_dfa_exec(), it was not
1741     anchoring the second and subsequent partial matches at the new starting
1742     point. This could lead to incorrect results. For example, with the pattern
1743     /1234/, partially matching against "123" and then "a4" gave a match.
1744    
1745     2. Changes to pcregrep:
1746    
1747     (a) All non-match returns from pcre_exec() were being treated as failures
1748     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1749     error message is output. Some extra information is given for the
1750     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1751     probably the only errors that are likely to be caused by users (by
1752     specifying a regex that has nested indefinite repeats, for instance).
1753     If there are more than 20 of these errors, pcregrep is abandoned.
1754    
1755     (b) A binary zero was treated as data while matching, but terminated the
1756     output line if it was written out. This has been fixed: binary zeroes
1757     are now no different to any other data bytes.
1758    
1759     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1760     used to set a locale for matching. The --locale=xxxx long option has
1761     been added (no short equivalent) to specify a locale explicitly on the
1762     pcregrep command, overriding the environment variables.
1763    
1764     (d) When -B was used with -n, some line numbers in the output were one less
1765     than they should have been.
1766    
1767     (e) Added the -o (--only-matching) option.
1768    
1769     (f) If -A or -C was used with -c (count only), some lines of context were
1770     accidentally printed for the final match.
1771    
1772     (g) Added the -H (--with-filename) option.
1773    
1774     (h) The combination of options -rh failed to suppress file names for files
1775     that were found from directory arguments.
1776    
1777     (i) Added the -D (--devices) and -d (--directories) options.
1778    
1779     (j) Added the -F (--fixed-strings) option.
1780    
1781     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1782    
1783     (l) Added the --colo(u)r option.
1784    
1785     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1786     is not present by default.
1787    
1788     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1789     items such as (?R) or (?1), when the recursion could match a number of
1790     alternatives. If it matched one of the alternatives, but subsequently,
1791     outside the recursion, there was a failure, the code tried to back up into
1792     the recursion. However, because of the way PCRE is implemented, this is not
1793     possible, and the result was an incorrect result from the match.
1794    
1795     In order to prevent this happening, the specification of recursion has
1796     been changed so that all such subpatterns are automatically treated as
1797     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1798    
1799     4. I had overlooked the fact that, in some locales, there are characters for
1800     which isalpha() is true but neither isupper() nor islower() are true. In
1801     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1802     and ordfeminine) are like this. This affected the treatment of \w and \W
1803     when they appeared in character classes, but not when they appeared outside
1804     a character class. The bit map for "word" characters is now created
1805     separately from the results of isalnum() instead of just taking it from the
1806     upper, lower, and digit maps. (Plus the underscore character, of course.)
1807    
1808     5. The above bug also affected the handling of POSIX character classes such as
1809     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1810     permanent tables. Instead, the bit maps for such a class were previously
1811     created as the appropriate unions of the upper, lower, and digit bitmaps.
1812     Now they are created by subtraction from the [[:word:]] class, which has
1813     its own bitmap.
1814    
1815     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1816     It is created by subtracting the vertical space characters (\x09, \x0a,
1817     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1818     subtraction was done in the overall bitmap for a character class, meaning
1819     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1820     be recognized. This bug has been fixed.
1821    
1822     7. Patches from the folks at Google:
1823    
1824     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1825     real life, but is still worth protecting against".
1826    
1827     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1828     regular expressions".
1829    
1830     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1831     have it.
1832    
1833     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1834     "configure" and the latter not, in order to fix a problem somebody had
1835     with compiling the Arg class on HP-UX.
1836    
1837     (e) Improve the error-handling of the C++ wrapper a little bit.
1838    
1839     (f) New tests for checking recursion limiting.
1840    
1841     8. The pcre_memmove() function, which is used only if the environment does not
1842     have a standard memmove() function (and is therefore rarely compiled),
1843     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1844     returning a result (though PCRE never actually uses the result).
1845    
1846     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1847     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1848     returned instead of calling malloc() with an overflowing number that would
1849     most likely cause subsequent chaos.
1850    
1851     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1852    
1853     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1854     with this option is matched, the nmatch and pmatch options of regexec() are
1855     ignored.
1856    
1857     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1858     provided in case anyone wants to the the POSIX interface with UTF-8
1859     strings.
1860    
1861     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1862     C++ linking (needed for some HP-UX environments).
1863    
1864     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1865     (unused parameter) and in the pcre_printint() function (omitted "default"
1866     switch label when the default is to do nothing).
1867    
1868     15. Added some code to make it possible, when PCRE is compiled as a C++
1869     library, to replace subject pointers for pcre_exec() with a smart pointer
1870     class, thus making it possible to process discontinuous strings.
1871    
1872     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1873     much the same function. They were added by different people who were trying
1874     to make PCRE easy to compile on non-Unix systems. It has been suggested
1875     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1876     for compiling on Windows systems. I have therefore replaced it with
1877     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1878     defaults to "extern" for C or "extern C" for C++, which works fine on
1879     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1880     SCOPE with something explicit in config.h. In addition:
1881    
1882     (a) pcreposix.h still had just "extern" instead of either of these macros;
1883     I have replaced it with PCRE_DATA_SCOPE.
1884    
1885     (b) Functions such as _pcre_xclass(), which are internal to the library,
1886     but external in the C sense, all had PCRE_EXPORT in their definitions.
1887     This is apparently wrong for the Windows case, so I have removed it.
1888     (It makes no difference on Unix-like systems.)
1889    
1890     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1891     of recursive calls to match(). This is different to MATCH_LIMIT because
1892     that limits the total number of calls to match(), not all of which increase
1893     the depth of recursion. Limiting the recursion depth limits the amount of
1894     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1895     when PCRE is compiled, and changed at run time. A patch from Google adds
1896     this functionality to the C++ interface.
1897    
1898     18. Changes to the handling of Unicode character properties:
1899    
1900     (a) Updated the table to Unicode 4.1.0.
1901    
1902     (b) Recognize characters that are not in the table as "Cn" (undefined).
1903    
1904     (c) I revised the way the table is implemented to a much improved format
1905     which includes recognition of ranges. It now supports the ranges that
1906     are defined in UnicodeData.txt, and it also amalgamates other
1907     characters into ranges. This has reduced the number of entries in the
1908     table from around 16,000 to around 3,000, thus reducing its size
1909     considerably. I realized I did not need to use a tree structure after
1910     all - a binary chop search is just as efficient. Having reduced the
1911     number of entries, I extended their size from 6 bytes to 8 bytes to
1912     allow for more data.
1913    
1914     (d) Added support for Unicode script names via properties such as \p{Han}.
1915    
1916     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1917     matching that character.
1918    
1919     20. When matching a repeated Unicode property with a minimum greater than zero,
1920     (for example \pL{2,}), PCRE could look past the end of the subject if it
1921     reached it while seeking the minimum number of characters. This could
1922     happen only if some of the characters were more than one byte long, because
1923     there is a check for at least the minimum number of bytes.
1924    
1925     21. Refactored the implementation of \p and \P so as to be more general, to
1926     allow for more different types of property in future. This has changed the
1927     compiled form incompatibly. Anybody with saved compiled patterns that use
1928     \p or \P will have to recompile them.
1929    
1930     22. Added "Any" and "L&" to the supported property types.
1931    
1932     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1933     but give a compile time error if the value is greater than 0xff.
1934    
1935     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1936     accidentally not being installed or uninstalled.
1937    
1938     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1939     made were to insert the current release number. This seemed silly, because
1940     it made things harder for people building PCRE on systems that don't run
1941     "configure". I have turned pcre.h into a distributed file, no longer built
1942     by "configure", with the version identification directly included. There is
1943     no longer a pcre.h.in file.
1944    
1945     However, this change necessitated a change to the pcre-config script as
1946     well. It is built from pcre-config.in, and one of the substitutions was the
1947     release number. I have updated configure.ac so that ./configure now finds
1948     the release number by grepping pcre.h.
1949    
1950     26. Added the ability to run the tests under valgrind.
1951    
1952    
1953 nigel 85 Version 6.4 05-Sep-05
1954     ---------------------
1955    
1956     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1957     "--" to be printed when multiple files were scanned, even when none of the
1958     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1959     consider it to be a bug, and have restored the previous behaviour.
1960    
1961     2. A couple of code tidies to get rid of compiler warnings.
1962    
1963     3. The pcretest program used to cheat by referring to symbols in the library
1964     whose names begin with _pcre_. These are internal symbols that are not
1965     really supposed to be visible externally, and in some environments it is
1966     possible to suppress them. The cheating is now confined to including
1967     certain files from the library's source, which is a bit cleaner.
1968    
1969     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1970     file's purpose clearer.
1971    
1972     5. Reorganized pcre_ucp_findchar().
1973    
1974    
1975 nigel 83 Version 6.3 15-Aug-05
1976     ---------------------
1977    
1978     1. The file libpcre.pc.in did not have general read permission in the tarball.
1979    
1980     2. There were some problems when building without C++ support:
1981    
1982     (a) If C++ support was not built, "make install" and "make test" still
1983     tried to test it.
1984    
1985     (b) There were problems when the value of CXX was explicitly set. Some
1986     changes have been made to try to fix these, and ...
1987    
1988     (c) --disable-cpp can now be used to explicitly disable C++ support.
1989    
1990     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1991     backslash in a target when C++ was disabled. This confuses some
1992     versions of "make", apparently. Using an intermediate variable solves
1993     this. (Same for CPP_LOBJ.)
1994    
1995     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1996     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1997     necessary on certain architectures.
1998    
1999     4. Added a setting of -export-symbols-regex to the link command to remove
2000     those symbols that are exported in the C sense, but actually are local
2001     within the library, and not documented. Their names all begin with
2002     "_pcre_". This is not a perfect job, because (a) we have to except some
2003     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2004     available (and never for static libraries). I have made a note to try to
2005     find a way round (a) in the future.
2006    
2007    
2008 nigel 81 Version 6.2 01-Aug-05
2009     ---------------------
2010    
2011     1. There was no test for integer overflow of quantifier values. A construction
2012     such as {1111111111111111} would give undefined results. What is worse, if
2013     a minimum quantifier for a parenthesized subpattern overflowed and became
2014     negative, the calculation of the memory size went wrong. This could have
2015     led to memory overwriting.
2016    
2017     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2018    
2019     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2020     operating environments where this matters.
2021    
2022     4. Applied Giuseppe Maxia's patch to add additional features for controlling
2023     PCRE options from within the C++ wrapper.
2024    
2025     5. Named capturing subpatterns were not being correctly counted when a pattern
2026     was compiled. This caused two problems: (a) If there were more than 100
2027     such subpatterns, the calculation of the memory needed for the whole
2028     compiled pattern went wrong, leading to an overflow error. (b) Numerical
2029     back references of the form \12, where the number was greater than 9, were
2030     not recognized as back references, even though there were sufficient
2031     previous subpatterns.
2032    
2033     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2034     versions of gcc, e.g. 2.95.4.
2035    
2036    
2037 nigel 79 Version 6.1 21-Jun-05
2038     ---------------------
2039    
2040     1. There was one reference to the variable "posix" in pcretest.c that was not
2041     surrounded by "#if !defined NOPOSIX".
2042    
2043     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2044     the cross-check on the old pcre_info() function, for the benefit of the
2045     cut-down version of PCRE that is currently imported into Exim.
2046    
2047     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2048     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2049     patterns that start (?i) but I don't think that matters. The use of (?i) is
2050     just an example; this all applies to the other options as well.
2051    
2052     4. Since libtool seems to echo the compile commands it is issuing, the output
2053     from "make" can be reduced a bit by putting "@" in front of each libtool
2054     compile command.
2055    
2056     5. Patch from the folks at Google for configure.in to be a bit more thorough
2057     in checking for a suitable C++ installation before trying to compile the
2058     C++ stuff. This should fix a reported problem when a compiler was present,
2059     but no suitable headers.
2060    
2061     6. The man pages all had just "PCRE" as their title. I have changed them to
2062     be the relevant file name. I have also arranged that these names are
2063     retained in the file doc/pcre.txt, which is a concatenation in text format
2064     of all the man pages except the little individual ones for each function.
2065    
2066     7. The NON-UNIX-USE file had not been updated for the different set of source
2067     files that come with release 6. I also added a few comments about the C++
2068     wrapper.
2069    
2070    
2071 nigel 77 Version 6.0 07-Jun-05
2072     ---------------------
2073    
2074     1. Some minor internal re-organization to help with my DFA experiments.
2075    
2076     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2077     didn't matter for the library itself when fully configured, but did matter
2078     when compiling without UCP support, or within Exim, where the ucp files are
2079     not imported.
2080    
2081     3. Refactoring of the library code to split up the various functions into
2082     different source modules. The addition of the new DFA matching code (see
2083     below) to a single monolithic source would have made it really too
2084     unwieldy, quite apart from causing all the code to be include in a
2085     statically linked application, when only some functions are used. This is
2086     relevant even without the DFA addition now that patterns can be compiled in
2087     one application and matched in another.
2088    
2089     The downside of splitting up is that there have to be some external
2090     functions and data tables that are used internally in different modules of
2091     the library but which are not part of the API. These have all had their
2092     names changed to start with "_pcre_" so that they are unlikely to clash
2093     with other external names.
2094    
2095     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2096     a different (DFA) algorithm. Although it is slower than the original
2097     function, it does have some advantages for certain types of matching
2098     problem.
2099    
2100     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2101     including restarting after a partial match.
2102    
2103     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2104     defined when compiling for Windows was sent to me. I have put it into the
2105     code, though I have no means of testing or verifying it.
2106    
2107     7. Added the pcre_refcount() auxiliary function.
2108    
2109     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2110     match before or at the first newline in the subject string. In pcretest,
2111     the /f option on a pattern can be used to set this.
2112    
2113     9. A repeated \w when used in UTF-8 mode with characters greater than 256
2114     would behave wrongly. This has been present in PCRE since release 4.0.
2115    
2116     10. A number of changes to the pcregrep command:
2117    
2118     (a) Refactored how -x works; insert ^(...)$ instead of setting
2119     PCRE_ANCHORED and checking the length, in preparation for adding
2120     something similar for -w.
2121    
2122     (b) Added the -w (match as a word) option.
2123    
2124     (c) Refactored the way lines are read and buffered so as to have more
2125     than one at a time available.
2126    
2127     (d) Implemented a pcregrep test script.
2128    
2129     (e) Added the -M (multiline match) option. This allows patterns to match
2130     over several lines of the subject. The buffering ensures that at least
2131     8K, or the rest of the document (whichever is the shorter) is available
2132     for matching (and similarly the previous 8K for lookbehind assertions).
2133    
2134     (f) Changed the --help output so that it now says
2135    
2136     -w, --word-regex(p)
2137    
2138     instead of two lines, one with "regex" and the other with "regexp"
2139     because that confused at least one person since the short forms are the
2140     same. (This required a bit of code, as the output is generated
2141     automatically from a table. It wasn't just a text change.)
2142    
2143     (g) -- can be used to terminate pcregrep options if the next thing isn't an
2144     option but starts with a hyphen. Could be a pattern or a path name
2145     starting with a hyphen, for instance.
2146    
2147     (h) "-" can be given as a file name to represent stdin.
2148    
2149     (i) When file names are being printed, "(standard input)" is used for
2150     the standard input, for compatibility with GNU grep. Previously
2151     "<stdin>" was used.
2152    
2153     (j) The option --label=xxx can be used to supply a name to be used for
2154     stdin when file names are being printed. There is no short form.
2155    
2156     (k) Re-factored the options decoding logic because we are going to add
2157     two more options that take data. Such options can now be given in four
2158     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2159    
2160     (l) Added the -A, -B, and -C options for requesting that lines of context
2161     around matches be printed.
2162    
2163     (m) Added the -L option to print the names of files that do not contain
2164     any matching lines, that is, the complement of -l.
2165    
2166     (n) The return code is 2 if any file cannot be opened, but pcregrep does
2167     continue to scan other files.
2168    
2169     (o) The -s option was incorrectly implemented. For compatibility with other
2170     greps, it now suppresses the error message for a non-existent or non-
2171     accessible file (but not the return code). There is a new option called
2172     -q that suppresses the output of matching lines, which was what -s was
2173     previously doing.
2174    
2175     (p) Added --include and --exclude options to specify files for inclusion
2176     and exclusion when recursing.
2177    
2178     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2179     Hopefully, it now does.
2180    
2181     12. Missing cast in pcre_study().
2182    
2183     13. Added an "uninstall" target to the makefile.
2184    
2185     14. Replaced "extern" in the function prototypes in Makefile.in with
2186     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2187     world, but is set differently for Windows.
2188    
2189     15. Added a second compiling function called pcre_compile2(). The only
2190     difference is that it has an extra argument, which is a pointer to an
2191     integer error code. When there is a compile-time failure, this is set
2192     non-zero, in addition to the error test pointer being set to point to an
2193     error message. The new argument may be NULL if no error number is required
2194     (but then you may as well call pcre_compile(), which is now just a
2195     wrapper). This facility is provided because some applications need a
2196     numeric error indication, but it has also enabled me to tidy up the way
2197     compile-time errors are handled in the POSIX wrapper.
2198    
2199     16. Added VPATH=.libs to the makefile; this should help when building with one
2200     prefix path and installing with another. (Or so I'm told by someone who
2201     knows more about this stuff than I do.)
2202    
2203     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2204     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2205     match everything, including newlines. This is not POSIX-compatible, but
2206     somebody wanted the feature. From pcretest it can be activated by using
2207     both the P and the s flags.
2208    
2209     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2210    
2211     19. libpcre.pc was being incorrectly installed as executable.
2212    
2213     20. A couple of places in pcretest check for end-of-line by looking for '\n';
2214     it now also looks for '\r' so that it will work unmodified on Windows.
2215    
2216     21. Added Google's contributed C++ wrapper to the distribution.
2217    
2218     22. Added some untidy missing memory free() calls in pcretest, to keep
2219     Electric Fence happy when testing.
2220    
2221    
2222    
2223 nigel 75 Version 5.0 13-Sep-04
2224     ---------------------
2225    
2226     1. Internal change: literal characters are no longer packed up into items
2227     containing multiple characters in a single byte-string. Each character
2228     is now matched using a separate opcode. However, there may be more than one
2229     byte in the character in UTF-8 mode.
2230    
2231     2. The pcre_callout_block structure has two new fields: pattern_position and
2232     next_item_length. These contain the offset in the pattern to the next match
2233     item, and its length, respectively.
2234    
2235     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2236     insertion of callouts before each pattern item. Added the /C option to
2237     pcretest to make use of this.
2238    
2239     4. On the advice of a Windows user, the lines
2240    
2241     #if defined(_WIN32) || defined(WIN32)
2242     _setmode( _fileno( stdout ), 0x8000 );
2243     #endif /* defined(_WIN32) || defined(WIN32) */
2244    
2245     have been added to the source of pcretest. This apparently does useful
2246     magic in relation to line terminators.
2247    
2248     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2249     for the benefit of those environments where the "b" makes a difference.
2250    
2251     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2252     to know about it. I have put a hack into configure.in that adds in code
2253     to set GCC=yes if CC=icc. This seems to end up at a point in the
2254     generated configure script that is early enough to affect the setting of
2255     compiler options, which is what is needed, but I have no means of testing
2256     whether it really works. (The user who reported this had patched the
2257     generated configure script, which of course I cannot do.)
2258    
2259     LATER: After change 22 below (new libtool files), the configure script
2260     seems to know about icc (and also ecc). Therefore, I have commented out
2261     this hack in configure.in.
2262    
2263     7. Added support for pkg-config (2 patches were sent in).
2264    
2265     8. Negated POSIX character classes that used a combination of internal tables
2266     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2267     [[:^ascii]]. Typically, they would match almost any characters. The other
2268     POSIX classes were not broken in this way.
2269    
2270     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2271     to find the match, as PCRE was deluded into thinking that the match had to
2272     start at the start point or following a newline. The same bug applied to
2273     patterns with negative forward assertions or any backward assertions
2274     preceding ".*" at the start, unless the pattern required a fixed first
2275     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2276    
2277     10. In UTF-8 mode, when moving forwards in the subject after a failed match
2278     starting at the last subject character, bytes beyond the end of the subject
2279     string were read.
2280    
2281     11. Renamed the variable "class" as "classbits" to make life easier for C++
2282     users. (Previously there was a macro definition, but it apparently wasn't
2283     enough.)
2284    
2285     12. Added the new field "tables" to the extra data so that tables can be passed
2286     in at exec time, or the internal tables can be re-selected. This allows
2287     a compiled regex to be saved and re-used at a later time by a different
2288     program that might have everything at different addresses.
2289    
2290     13. Modified the pcre-config script so that, when run on Solaris, it shows a
2291     -R library as well as a -L library.
2292    
2293     14. The debugging options of pcretest (-d on the command line or D on a
2294     pattern) showed incorrect output for anything following an extended class
2295     that contained multibyte characters and which was followed by a quantifier.
2296    
2297     15. Added optional support for general category Unicode character properties
2298     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2299     support. It adds about 90K to the size of the library. The meanings of the
2300     inbuilt class escapes such as \d and \s have NOT been changed.
2301    
2302     16. Updated pcredemo.c to include calls to free() to release the memory for the
2303     compiled pattern.
2304    
2305     17. The generated file chartables.c was being created in the source directory
2306     instead of in the building directory. This caused the build to fail if the
2307     source directory was different from the building directory, and was
2308     read-only.
2309    
2310     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2311     file. No doubt somebody will tell me if they don't make sense... Also added
2312     Dan Mooney's comments about building on OpenVMS.
2313    
2314     19. Added support for partial matching via the PCRE_PARTIAL option for
2315     pcre_exec() and the \P data escape in pcretest.
2316    
2317     20. Extended pcretest with 3 new pattern features:
2318    
2319     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2320     write the compiled pattern to the file whose name is "rest-of-line".
2321     This is a straight binary dump of the data, with the saved pointer to
2322     the character tables forced to be NULL. The study data, if any, is
2323     written too. After writing, pcretest reads a new pattern.
2324    
2325     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2326     compiled pattern from the given file. There must not be any
2327     occurrences of "<" in the file name (pretty unlikely); if there are,
2328     pcretest will instead treat the initial "<" as a pattern delimiter.
2329     After reading in the pattern, pcretest goes on to read data lines as
2330     usual.
2331    
2332     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2333     and 16-bit fields in a compiled pattern, to simulate a pattern that
2334     was compiled on a host of opposite endianness.
2335    
2336     21. The pcre-exec() function can now cope with patterns that were compiled on
2337     hosts of opposite endianness, with this restriction:
2338    
2339     As for any compiled expression that is saved and used later, the tables
2340     pointer field cannot be preserved; the extra_data field in the arguments
2341     to pcre_exec() should be used to pass in a tables address if a value
2342     other than the default internal tables were used at compile time.
2343    
2344     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2345     now diagnosed as an error. Previously, most of the time, a negative number
2346     would have been treated as zero, but if in addition "ovector" was passed as
2347     NULL, a crash could occur.
2348    
2349     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2350     new versions from the libtool 1.5 distribution (the last one is a copy of
2351     a file called libtool.m4). This seems to have fixed the need to patch
2352     "configure" to support Darwin 1.3 (which I used to do). However, I still
2353     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2354     workstation).
2355    
2356     24. Changed the PCRE licence to be the more standard "BSD" licence.
2357    
2358    
2359 nigel 73 Version 4.5 01-Dec-03
2360     ---------------------
2361    
2362     1. There has been some re-arrangement of the code for the match() function so
2363     that it can be compiled in a version that does not call itself recursively.
2364     Instead, it keeps those local variables that need separate instances for
2365     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2366     needs to "recurse". Keeping track of where control must go is done by means
2367     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2368     hide most of the details from the main code, and operates only if
2369     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2370     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2371     operating.
2372    
2373     To make it easier for callers to provide specially tailored get/free
2374     functions for this usage, two new functions, pcre_stack_malloc, and
2375     pcre_stack_free, are used. They are always called in strict stacking order,
2376     and the size of block requested is always the same.
2377    
2378     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2379     PCRE has been compiled to use the stack or the heap for recursion. The
2380     -C option of pcretest uses this to show which version is compiled.
2381    
2382     A new data escape \S, is added to pcretest; it causes the amounts of store
2383     obtained and freed by both kinds of malloc/free at match time to be added
2384     to the output.
2385    
2386     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2387     what's available on my current Linux desktop machine.
2388    
2389     3. When matching a UTF-8 string, the test for a valid string at the start has
2390     been extended. If start_offset is not zero, PCRE now checks that it points
2391     to a byte that is the start of a UTF-8 character. If not, it returns
2392     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2393     this is necessary because there may be backward assertions in the pattern.
2394     When matching the same subject several times, it may save resources to use
2395     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2396    
2397     4. The code for checking the validity of UTF-8 strings has been tightened so
2398     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2399     containing "overlong sequences".
2400    
2401     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2402     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2403     should have been "&", but it just so happened that all the cases this let
2404     through by mistake were picked up later in the function.
2405    
2406     6. I had used a variable called "isblank" - this is a C99 function, causing
2407     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2408    
2409     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2410     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2411     so the version is shown; (c) stop "make test" echoing "./RunTest".
2412    
2413     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2414    
2415     9. The prototype for memmove() for systems that don't have it was using
2416     size_t, but the inclusion of the header that defines size_t was later. I've
2417     moved the #includes for the C headers earlier to avoid this.
2418    
2419     10. Added some adjustments to the code to make it easier to compiler on certain
2420     special systems:
2421    
2422     (a) Some "const" qualifiers were missing.
2423     (b) Added the macro EXPORT before all exported functions; by default this
2424     is defined to be empty.
2425     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2426     that it reads its output file name as an argument instead of writing
2427     to the standard output and assuming this can be redirected.
2428    
2429     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2430     class containing characters with values greater than 255, PCRE compilation
2431     went into a loop.
2432    
2433     12. A recursive reference to a subpattern that was within another subpattern
2434     that had a minimum quantifier of zero caused PCRE to crash. For example,
2435     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2436     recursion. If the recursively-called subpattern itself had a zero repeat,
2437     that was OK.
2438    
2439     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2440     buffer into which it was copied (for escape processing) was still set at
2441     1024, so long lines caused crashes.
2442    
2443     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2444     "internal error: code overflow...". This applied to any character class
2445     that was followed by a possessive quantifier.
2446    
2447     15. Modified the Makefile to add libpcre.la as a prerequisite for
2448     libpcreposix.la because I was told this is needed for a parallel build to
2449     work.
2450    
2451     16. If a pattern that contained .* following optional items at the start was
2452     studied, the wrong optimizing data was generated, leading to matching
2453     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2454     matching string must start with a or b or c. The correct conclusion for
2455     this pattern is that a match can start with any character.
2456    
2457    
2458 nigel 71 Version 4.4 13-Aug-03
2459     ---------------------
2460    
2461     1. In UTF-8 mode, a character class containing characters with values between
2462     127 and 255 was not handled correctly if the compiled pattern was studied.
2463     In fixing this, I have also improved the studying algorithm for such
2464     classes (slightly).
2465    
2466     2. Three internal functions had redundant arguments passed to them. Removal
2467     might give a very teeny performance improvement.
2468    
2469     3. Documentation bug: the value of the capture_top field in a callout is *one
2470     more than* the number of the hightest numbered captured substring.
2471    
2472     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2473     in incorrectly linking with a previously installed version. They now link
2474     explicitly with libpcre.la.
2475    
2476     5. configure.in no longer needs to recognize Cygwin specially.
2477    
2478     6. A problem in pcre.in for Windows platforms is fixed.
2479    
2480     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2481     pcretest, it used to include the size of the study block as part of its
2482     output. Unfortunately, the structure contains a field that has a different
2483     size on different hardware architectures. This meant that the tests that
2484     showed this size failed. As the block is currently always of a fixed size,
2485     this information isn't actually particularly useful in pcretest output, so
2486     I have just removed it.
2487    
2488     8. Three pre-processor statements accidentally did not start in column 1.
2489     Sadly, there are *still* compilers around that complain, even though
2490     standard C has not required this for well over a decade. Sigh.
2491    
2492     9. In pcretest, the code for checking callouts passed small integers in the
2493     callout_data field, which is a void * field. However, some picky compilers
2494     complained about the casts involved for this on 64-bit systems. Now
2495     pcretest passes the address of the small integer instead, which should get
2496     rid of the warnings.
2497    
2498     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2499     both compile and run time, and gives an error if an invalid UTF-8 sequence
2500     is found. There is a option for disabling this check in cases where the
2501     string is known to be correct and/or the maximum performance is wanted.
2502    
2503     11. In response to a bug report, I changed one line in Makefile.in from
2504    
2505     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2506     to
2507     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2508    
2509     to look similar to other lines, but I have no way of telling whether this
2510     is the right thing to do, as I do not use Windows. No doubt I'll get told
2511     if it's wrong...
2512    
2513    
2514 nigel 69 Version 4.3 21-May-03
2515     ---------------------
2516    
2517     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2518     Makefile.
2519    
2520     2. Some refactoring to improve the quality of the code:
2521    
2522     (i) The utf8_table... variables are now declared "const".
2523    
2524     (ii) The code for \cx, which used the "case flipping" table to upper case
2525     lower case letters, now just substracts 32. This is ASCII-specific,
2526     but the whole concept of \cx is ASCII-specific, so it seems
2527     reasonable.
2528    
2529     (iii) PCRE was using its character types table to recognize decimal and
2530     hexadecimal digits in the pattern. This is silly, because it handles
2531     only 0-9, a-f, and A-F, but the character types table is locale-
2532     specific, which means strange things might happen. A private
2533     table is now used for this - though it costs 256 bytes, a table is
2534     much faster than multiple explicit tests. Of course, the standard
2535     character types table is still used for matching digits in subject
2536     strings against \d.
2537    
2538     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2539     ending in _t are). So I've renamed it as ESC_tee.
2540    
2541     3. The first argument for regexec() in the POSIX wrapper should have been
2542     defined as "const".
2543    
2544     4. Changed pcretest to use malloc() for its buffers so that they can be
2545     Electric Fenced for debugging.
2546    
2547     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2548     to read one or more bytes before the start of the subject string. Often this
2549     had no effect on PCRE's behaviour, but in some circumstances it could
2550     provoke a segmentation fault.
2551    
2552     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2553     to try to read one or more bytes before the start of the subject string.
2554    
2555     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2556     UTF-8 support could misbehave in various ways if the subject string
2557     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2558     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2559     back over UTF-8 characters.)
2560    
2561    
2562 nigel 67 Version 4.2 14-Apr-03
2563     ---------------------
2564    
2565     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2566    
2567     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2568     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2569     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2570     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2571     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2572     and BUILD_EXEEXT
2573     Note: automatic setting of the BUILD variables is not yet working
2574     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2575     compile-time but not at link-time
2576     [LINK]: use for linking executables only
2577     make different versions for Windows and non-Windows
2578     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2579     libraries
2580     [LINK_FOR_BUILD]: new variable
2581     [OBJEXT]: use throughout
2582     [EXEEXT]: use throughout
2583     <winshared>: new target
2584     <wininstall>: new target
2585     <dftables.o>: use native compiler
2586     <dftables>: use native linker
2587     <install>: handle Windows platform correctly
2588     <clean>: ditto
2589     <check>: ditto
2590     copy DLL to top builddir before testing
2591    
2592     As part of these changes, -no-undefined was removed again. This was reported
2593     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2594     in any case.
2595    
2596     3. Some tidies to get rid of compiler warnings:
2597    
2598     . In the match_data structure, match_limit was an unsigned long int, whereas
2599     match_call_count was an int. I've made them both unsigned long ints.
2600    
2601     . In pcretest the fact that a const uschar * doesn't automatically cast to
2602     a void * provoked a warning.
2603    
2604     . Turning on some more compiler warnings threw up some "shadow" variables
2605     and a few more missing casts.
2606    
2607     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2608     option, a class that contained a single character with a value between 128
2609     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2610    
2611     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2612     option, a class that contained several characters, but with at least one
2613     whose value was between 128 and 255 caused PCRE to crash.
2614    
2615    
2616 nigel 65 Version 4.1 12-Mar-03
2617     ---------------------
2618 nigel 63
2619 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2620     needed, and a string in dftables.c that was longer than standard compilers are
2621     required to support.
2622    
2623     2. Compiling with Sun's compiler found a few more places where the code could
2624     be tidied up in order to avoid warnings.
2625    
2626     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2627     first of these names is deprecated in the latest Autoconf in favour of the name
2628     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2629     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2630     analogy I have changed it to CFLAGS_FOR_BUILD.
2631    
2632     4. Added -no-undefined to the linking command in the Makefile, because this is
2633     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2634     linking step for the pcreposix library.
2635    
2636     5. PCRE was failing to diagnose the case of two named groups with the same
2637     name.
2638    
2639     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2640     literal character that is needed in the subject for a match, and scans along to
2641     ensure that it is present before embarking on the full matching process. This
2642     saves time in cases of nested unlimited repeats that are never going to match.
2643     Problem: the scan can take a lot of time if the subject is very long (e.g.
2644     megabytes), thus penalizing straightforward matches. It is now done only if the
2645     amount of subject to be scanned is less than 1000 bytes.
2646    
2647     7. A lesser problem with the same optimization is that it was recording the
2648     first character of an anchored pattern as "needed", thus provoking a search
2649     right along the subject, even when the first match of the pattern was going to
2650     fail. The "needed" character is now not set for anchored patterns, unless it
2651     follows something in the pattern that is of non-fixed length. Thus, it still
2652     fulfils its original purpose of finding quick non-matches in cases of nested
2653     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2654    
2655    
2656     Version 4.0 17-Feb-03
2657     ---------------------
2658    
2659 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2660     extended to the end of string, PCRE compiled incorrect data. This could lead to
2661     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2662    
2663     2. Moved to autoconf 2.53 and libtool 1.4.2.
2664    
2665     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2666     the special perltest8 script is no longer needed - all the tests can be run
2667     from a single perltest script.
2668    
2669     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2670     by \s. It has now been removed in PCRE. This means it isn't recognized as
2671     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2672     class [:space:] *does* include VT, thereby creating a mess.
2673    
2674     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2675     space and tab.
2676    
2677     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2678     its new features into the main test script, reducing the number of scripts.
2679    
2680     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2681     were backward compatible, and made the (?i) apply to the whole pattern, as if
2682     /i were given. Now it behaves more logically, and applies the option setting
2683     only to what follows. PCRE has been changed to follow suit. However, if it
2684     finds options settings right at the start of the pattern, it extracts them into
2685     the global options, as before. Thus, they show up in the info data.
2686    
2687     8. Added support for the \Q...\E escape sequence. Characters in between are
2688     treated as literals. This is slightly different from Perl in that $ and @ are
2689     also handled as literals inside the quotes. In Perl, they will cause variable
2690     interpolation. Note the following examples:
2691    
2692     Pattern PCRE matches Perl matches
2693    
2694     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2695     \Qabc\$xyz\E abc\$xyz abc\$xyz
2696     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2697    
2698     For compatibility with Perl, \Q...\E sequences are recognized inside character
2699     classes as well as outside them.
2700    
2701     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2702     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2703     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2704     signed/unsigned warnings.
2705    
2706     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2707     option for pcretest, so I've replaced it by a simple function that does just
2708     that job.
2709    
2710     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2711     "pcregrep -".
2712    
2713     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2714     Java package. This provides some syntactic sugar for simple cases of what my
2715     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2716     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2717     item, you can use this simplified notation. Note that only makes sense with
2718     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2719     greediness, whatever the setting of the PCRE_UNGREEDY option.
2720    
2721     13. A change of greediness default within a pattern was not taking effect at
2722     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2723     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2724     was abstracted outside.
2725    
2726     14. PCRE now supports the \G assertion. It is true when the current matching
2727     position is at the start point of the match. This differs from \A when the
2728     starting offset is non-zero. Used with the /g option of pcretest (or similar
2729     code), it works in the same way as it does for Perl's /g option. If all
2730     alternatives of a regex begin with \G, the expression is anchored to the start
2731     match position, and the "anchored" flag is set in the compiled expression.
2732    
2733     15. Some bugs concerning the handling of certain option changes within patterns
2734     have been fixed. These applied to options other than (?ims). For example,
2735     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2736     been the other way round. Some of this was related to change 7 above.
2737    
2738     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2739     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2740     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2741     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2742    
2743     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2744     mode. Unlike ".", it always matches newline, whatever the setting of
2745     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2746     assertions. Perl allows it, but it doesn't (in general) work because it can't
2747     calculate the length of the lookbehind. At least, that's the case for Perl
2748     5.8.0 - I've been told they are going to document that it doesn't work in
2749     future.
2750    
2751     18. Added an error diagnosis for escapes that PCRE does not support: these are
2752     \L, \l, \N, \P, \p, \U, \u, and \X.
2753    
2754     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2755     reading past the end of the pattern in cases such as /[abcd/.
2756    
2757     20. PCRE was getting more memory than necessary for patterns with classes that
2758     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2759    
2760     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2761     compiling PCRE for use with Virtual Pascal.
2762    
2763     22. Small fix to the Makefile to make it work properly if the build is done
2764     outside the source tree.
2765    
2766     23. Added a new extension: a condition to go with recursion. If a conditional
2767     subpattern starts with (?(R) the "true" branch is used if recursion has
2768     happened, whereas the "false" branch is used only at the top level.
2769    
2770     24. When there was a very long string of literal characters (over 255 bytes
2771     without UTF support, over 250 bytes with UTF support), the computation of how
2772     much memory was required could be incorrect, leading to segfaults or other
2773     strange effects.
2774    
2775     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2776     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2777     there was a subsequent back reference to those brackets. This meant that, for
2778     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2779     possible to check for precisely this case. All we can do is abandon the
2780     optimization if .* occurs inside capturing brackets when there are any back
2781     references whatsoever. (See below for a better fix that came later.)
2782    
2783     26. The handling of the optimization for finding the first character of a
2784     non-anchored pattern, and for finding a character that is required later in the
2785     match were failing in some cases. This didn't break the matching; it just
2786     failed to optimize when it could. The way this is done has been re-implemented.
2787    
2788     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2789    
2790     28. Added a new feature that provides some of the functionality that Perl
2791     provides with (?{...}). The facility is termed a "callout". The way it is done
2792     in PCRE is for the caller to provide an optional function, by setting
2793     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2794     global variable. By default it is unset, which disables all calling out. To get
2795     the function called, the regex must include (?C) at appropriate points. This
2796     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2797     This provides a means of identifying different callout points. When PCRE
2798     reaches such a point in the regex, if pcre_callout has been set, the external
2799     function is called. It is provided with data in a structure called
2800     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2801     matching continues; if it returns a non-zero value, the match at the current
2802     point fails. However, backtracking will occur if possible. [This was changed
2803     later and other features added - see item 49 below.]
2804    
2805     29. pcretest is upgraded to test the callout functionality. It provides a
2806     callout function that displays information. By default, it shows the start of
2807     the match and the current position in the text. There are some new data escapes
2808     to vary what happens:
2809    
2810     \C+ in addition, show current contents of captured substrings
2811     \C- do not supply a callout function
2812     \C!n return 1 when callout number n is reached
2813     \C!n!m return 1 when callout number n is reached for the mth time
2814    
2815     30. If pcregrep was called with the -l option and just a single file name, it
2816     output "<stdin>" if a match was found, instead of the file name.
2817    
2818     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2819     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2820     pcre_exec(). This saves a malloc/free per call. The default value of
2821     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2822     when configuring.
2823    
2824     32. The default maximum size of a compiled pattern is 64K. There have been a
2825     few cases of people hitting this limit. The code now uses macros to handle the
2826     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2827     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2828     configuring. Tests 2 and 5 work only with 2-byte links because they output
2829     debugging information about compiled patterns.
2830    
2831     33. Internal code re-arrangements:
2832    
2833     (a) Moved the debugging function for printing out a compiled regex into
2834     its own source file (printint.c) and used #include to pull it into
2835     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2836     separate copies.
2837    
2838     (b) Defined the list of op-code names for debugging as a macro in
2839     internal.h so that it is next to the definition of the opcodes.
2840    
2841     (c) Defined a table of op-code lengths for simpler skipping along compiled
2842     code. This is again a macro in internal.h so that it is next to the
2843     definition of the opcodes.
2844    
2845     34. Added support for recursive calls to individual subpatterns, along the
2846     lines of Robin Houston's patch (but implemented somewhat differently).
2847    
2848     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2849     allow it to read and process whole directories in Win32. This code was
2850     contributed by Lionel Fourquaux; it has not been tested by me.
2851    
2852     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2853     used to name a group. Names consist of alphanumerics and underscores, and must
2854     be unique. Back references use the syntax (?P=name) and recursive calls use
2855     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2856     numbers. The function pcre_fullinfo() can be used after compilation to extract
2857     a name/number map. There are three relevant calls:
2858    
2859     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2860     PCRE_INFO_NAMECOUNT yields the number of entries
2861     PCRE_INFO_NAMETABLE yields a pointer to the map.
2862    
2863     The map is a vector of fixed-size entries. The size of each entry depends on
2864     the length of the longest name used. The first two bytes of each entry are the
2865     group number, most significant byte first. There follows the corresponding
2866     name, zero terminated. The names are in alphabetical order.
2867    
2868     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2869     case instead of 255. Making it the same both with and without UTF-8 support
2870     means that the same test output works with both.
2871    
2872     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2873     calling malloc() with a zero argument.
2874    
2875     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2876     optimization. I've improved things by keeping a bitmap of backreferences with
2877     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2878     fact referenced, the optimization can be applied. It is unlikely that a
2879     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2880     the match to follow \n) will appear inside brackets with a number greater than
2881     31, but if it does, any back reference > 31 suppresses the optimization.
2882    
2883     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2884     of disabling numbered capturing parentheses. Any opening parenthesis that is
2885     not followed by ? behaves as if it were followed by ?: but named parentheses
2886     can still be used for capturing (and they will acquire numbers in the usual
2887     way).
2888    
2889     41. Redesigned the return codes from the match() function into yes/no/error so
2890     that errors can be passed back from deep inside the nested calls. A malloc
2891     failure while inside a recursive subpattern call now causes the
2892     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2893    
2894     42. It is now possible to set a limit on the number of times the match()
2895     function is called in a call to pcre_exec(). This facility makes it possible to
2896     limit the amount of recursion and backtracking, though not in a directly
2897     obvious way, because the match() function is used in a number of different
2898     circumstances. The count starts from zero for each position in the subject
2899     string (for non-anchored patterns). The default limit is, for compatibility, a
2900     large number, namely 10 000 000. You can change this in two ways:
2901    
2902     (a) When configuring PCRE before making, you can use --with-match-limit=n
2903     to set a default value for the compiled library.
2904    
2905     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2906     a different value is set. See 45 below.
2907    
2908     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2909    
2910     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2911     of things that can be changed at compile time. The first argument specifies
2912     what is wanted and the second points to where the information is to be placed.
2913     The current list of available information is:
2914    
2915     PCRE_CONFIG_UTF8
2916    
2917     The output is an integer that is set to one if UTF-8 support is available;
2918     otherwise it is set to zero.
2919    
2920     PCRE_CONFIG_NEWLINE
2921    
2922     The output is an integer that it set to the value of the code that is used for
2923     newline. It is either LF (10) or CR (13).
2924    
2925     PCRE_CONFIG_LINK_SIZE
2926    
2927     The output is an integer that contains the number of bytes used for internal
2928     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2929    
2930     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2931    
2932     The output is an integer that contains the threshold above which the POSIX
2933     interface uses malloc() for output vectors. See item 31 above.
2934    
2935     PCRE_CONFIG_MATCH_LIMIT
2936    
2937     The output is an unsigned integer that contains the default limit of the number
2938     of match() calls in a pcre_exec() execution. See 42 above.
2939    
2940     44. pcretest has been upgraded by the addition of the -C option. This causes it
2941     to extract all the available output from the new pcre_config() function, and to
2942     output it. The program then exits immediately.
2943    
2944     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2945     order to support additional features. One way would have been to define
2946     pcre_exec2() (for example) with extra arguments, but this would not have been
2947     extensible, and would also have required all calls to the original function to
2948     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2949     is used for passing in "extra" data from pcre_study().
2950    
2951     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2952     contains the following fields:
2953    
2954     flags a bitmap indicating which of the following fields are set
2955     study_data opaque data from pcre_study()
2956     match_limit a way of specifying a limit on match() calls for a specific
2957     call to pcre_exec()
2958     callout_data data for callouts (see 49 below)
2959    
2960     The flag bits are also defined in pcre.h, and are
2961    
2962     PCRE_EXTRA_STUDY_DATA
2963     PCRE_EXTRA_MATCH_LIMIT
2964     PCRE_EXTRA_CALLOUT_DATA
2965    
2966     The pcre_study() function now returns one of these new pcre_extra blocks, with
2967     the actual study data pointed to by the study_data field, and the
2968     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2969     before. That is, this change is entirely upwards-compatible and requires no
2970     change to existing code.
2971    
2972     If you want to pass in additional data to pcre_exec(), you can either place it
2973     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2974     block.
2975    
2976     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2977     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2978     times with different match limits, until it finds the minimum value needed for
2979     pcre_exec() to complete. The value is then output. This can be instructive; for
2980     most simple matches the number is quite small, but for pathological cases it
2981     gets very large very quickly.
2982    
2983     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2984     returns the size of the data block pointed to by the study_data field in a
2985     pcre_extra block, that is, the value that was passed as the argument to
2986     pcre_malloc() when PCRE was getting memory in which to place the information
2987     created by pcre_study(). The fourth argument should point to a size_t variable.
2988     pcretest has been extended so that this information is shown after a successful
2989     pcre_study() call when information about the compiled regex is being displayed.
2990    
2991     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2992     because what follows is always an absolute path. (Later: it turns out that this
2993     is more than cosmetic for MinGW, because it doesn't like empty path
2994     components.)
2995    
2996     49. Some changes have been made to the callout feature (see 28 above):
2997    
2998     (i) A callout function now has three choices for what it returns:
2999    
3000     0 => success, carry on matching
3001     > 0 => failure at this point, but backtrack if possible
3002     < 0 => serious error, return this value from pcre_exec()
3003    
3004     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3005     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3006     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3007     use by callout functions. It will never be used by PCRE itself.
3008    
3009     (ii) The pcre_extra structure (see 45 above) has a void * field called
3010     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3011     pcre_callout_block structure has a field of the same name. The contents of
3012     the field passed in the pcre_extra structure are passed to the callout
3013     function in the corresponding field in the callout block. This makes it
3014     easier to use the same callout-containing regex from multiple threads. For
3015     testing, the pcretest program has a new data escape
3016    
3017     \C*n pass the number n (may be negative) as callout_data
3018    
3019     If the callout function in pcretest receives a non-zero value as
3020     callout_data, it returns that value.
3021    
3022     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3023     there were some redundant $(CFLAGS) in commands that are now specified as
3024     $(LINK), which already includes $(CFLAGS).
3025    
3026     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3027     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3028     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3029     one-byte characters throughout. Note that case-insensitive matching applies
3030     only to characters whose values are less than 256. PCRE doesn't support the
3031     notion of cases for higher-valued characters.
3032    
3033     (i) A character class whose characters are all within 0-255 is handled as
3034     a bit map, and the map is inverted for negative classes. Previously, a
3035     character > 255 always failed to match such a class; however it should
3036     match if the class was a negative one (e.g. [^ab]). This has been fixed.
3037    
3038     (ii) A negated character class with a single character < 255 is coded as
3039     "not this character" (OP_NOT). This wasn't working properly when the test
3040     character was multibyte, either singly or repeated.
3041    
3042     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3043     mode, for example: \x{100}{2,3}.
3044    
3045     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3046     singly or repeated) now correctly test multibyte characters. However,
3047     PCRE doesn't recognize any characters with values greater than 255 as
3048     digits, spaces, or word characters. Such characters always match \D, \S,
3049     and \W, and never match \d, \s, or \w.
3050    
3051     (v) Classes may now contain characters and character ranges with values
3052     greater than 255. For example: [ab\x{100}-\x{400}].
3053    
3054     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3055     PCRE in UTF-8 mode.
3056    
3057     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3058     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3059     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3060     value.)
3061    
3062     53. The single man page has become too large. I have therefore split it up into
3063     a number of separate man pages. These also give rise to individual HTML pages;
3064     these are now put in a separate directory, and there is an index.html page that
3065     lists them all. Some hyperlinking between the pages has been installed.
3066    
3067     54. Added convenience functions for handling named capturing parentheses.
3068    
3069     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3070     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3071     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3072     are faulted.
3073    
3074     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3075     calling configure. These values are used when compiling the dftables.c program
3076     which is run to generate the source of the default character tables. They
3077     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3078     you will need to set these values.
3079    
3080     57. Updated the building process for Windows DLL, as provided by Fred Cox.
3081    
3082    
3083     Version 3.9 02-Jan-02
3084 nigel 61 ---------------------
3085    
3086     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3087    
3088     2. If --disable-static was given, the building process failed when trying to
3089     build pcretest and pcregrep. (For some reason it was using libtool to compile
3090     them, which is not right, as they aren't part of the library.)
3091    
3092    
3093 nigel 59 Version 3.8 18-Dec-01
3094     ---------------------
3095    
3096     1. The experimental UTF-8 code was completely screwed up. It was packing the
3097     bytes in the wrong order. How dumb can you get?
3098    
3099    
3100 nigel 57 Version 3.7 29-Oct-01
3101     ---------------------
3102    
3103     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3104     This caused pcretest, when used on the test data, to segfault. Unfortunately,
3105     this didn't happen under Solaris 8, where I normally test things.
3106    
3107 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3108     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3109     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3110     this fix an hour or so after the initial 3.7 release.)
3111 nigel 57
3112 nigel 59
3113 nigel 55 Version 3.6 23-Oct-01
3114     ---------------------
3115    
3116     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3117     offsets passed as NULL with zero offset count.
3118    
3119     2. The config.guess and config.sub files had not been updated when I moved to
3120     the latest autoconf.
3121    
3122    
3123 nigel 53 Version 3.5 15-Aug-01
3124     ---------------------
3125 nigel 5
3126 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3127     had been forgotten.
3128    
3129     2. By using declared but undefined structures, we can avoid using "void"
3130     definitions in pcre.h while keeping the internal definitions of the structures
3131     private.
3132    
3133     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3134     user point of view, this means that both static and shared libraries are built
3135     by default, but this can be individually controlled. More of the work of
3136     handling this static/shared cases is now inside libtool instead of PCRE's make
3137     file.
3138    
3139     4. The pcretest utility is now installed along with pcregrep because it is
3140     useful for users (to test regexs) and by doing this, it automatically gets
3141     relinked by libtool. The documentation has been turned into a man page, so
3142     there are now .1, .txt, and .html versions in /doc.
3143    
3144     5. Upgrades to pcregrep:
3145     (i) Added long-form option names like gnu grep.
3146     (ii) Added --help to list all options with an explanatory phrase.
3147     (iii) Added -r, --recursive to recurse into sub-directories.
3148     (iv) Added -f, --file to read patterns from a file.
3149    
3150     6. pcre_exec() was referring to its "code" argument before testing that
3151     argument for NULL (and giving an error if it was NULL).
3152    
3153     7. Upgraded Makefile.in to allow for compiling in a different directory from
3154     the source directory.
3155    
3156     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3157     options bits, the pointer it was passed was to an int instead of to an unsigned
3158     long int. This mattered only on 64-bit systems.
3159    
3160     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3161     generated) instead of pcre.in, which it its source. Also made the same change
3162     in several of the .c files.
3163    
3164     10. A new release of gcc defines printf() as a macro, which broke pcretest
3165     because it had an ifdef in the middle of a string argument for printf(). Fixed
3166     by using separate calls to printf().
3167    
3168     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3169     script, to force use of CR or LF instead of \n in the source. On non-Unix
3170     systems, the value can be set in config.h.
3171    
3172     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3173     absolute limit. Changed the text of the error message to make this clear, and
3174     likewise updated the man page.
3175    
3176     13. The limit of 99 on the number of capturing subpatterns has been removed.
3177     The new limit is 65535, which I hope will not be a "real" limit.
3178    
3179    
3180 nigel 51 Version 3.4 22-Aug-00
3181     ---------------------
3182    
3183     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3184    
3185     2. Diagnose condition (?(0) as an error instead of crashing on matching.
3186    
3187    
3188 nigel 49 Version 3.3 01-Aug-00
3189     ---------------------
3190    
3191     1. If an octal character was given, but the value was greater than \377, it
3192     was not getting masked to the least significant bits, as documented. This could
3193     lead to crashes in some systems.
3194    
3195     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3196     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3197    
3198     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3199     These just pass their arguments on to (pcre_free)(), but they are provided
3200     because some uses of PCRE bind it to non-C systems that can call its functions,
3201     but cannot call free() or pcre_free() directly.
3202    
3203     4. Add "make test" as a synonym for "make check". Corrected some comments in
3204     the Makefile.
3205    
3206     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3207     Makefile.
3208    
3209     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3210     command called pgrep for grepping around the active processes.
3211    
3212     7. Added the beginnings of support for UTF-8 character strings.
3213    
3214     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3215     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3216     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3217     out for the ar command.)
3218    
3219    
3220 nigel 47 Version 3.2 12-May-00
3221     ---------------------
3222    
3223     This is purely a bug fixing release.
3224    
3225     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3226     of ZA. This was just one example of several cases that could provoke this bug,
3227     which was introduced by change 9 of version 2.00. The code for breaking
3228     infinite loops after an iteration that matches an empty string was't working
3229     correctly.
3230    
3231     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3232     when matched against abbab (for example). After matching an empty string, it
3233     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3234     caused it to match further down the string than it should.
3235    
3236     3. The code contained an inclusion of sys/types.h. It isn't clear why this
3237     was there because it doesn't seem to be needed, and it causes trouble on some
3238     systems, as it is not a Standard C header. It has been removed.
3239    
3240     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3241     were reported on the Macintosh. The changes were from
3242    
3243     while ((c = *(++ptr)) != 0 && c != '\n');
3244     to
3245     while ((c = *(++ptr)) != 0 && c != '\n') ;
3246    
3247     Totally extraordinary, but if that's what it takes...
3248    
3249     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3250     available. Added HAVE_BCOPY and an autoconf test for it; if neither
3251     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3252     assumes the way PCRE uses memmove() (always moving upwards).
3253    
3254     6. PCRE is being used in one environment where strchr() is not available. There
3255     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3256     faster code anyway.
3257    
3258    
3259 nigel 45 Version 3.1 09-Feb-00
3260     ---------------------
3261    
3262     The only change in this release is the fixing of some bugs in Makefile.in for
3263     the "install" target:
3264    
3265     (1) It was failing to install pcreposix.h.
3266    
3267     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3268    
3269    
3270 nigel 43 Version 3.0 01-Feb-00
3271     ---------------------
3272 nigel 41
3273     1. Add support for the /+ modifier to perltest (to output $` like it does in
3274     pcretest).
3275    
3276     2. Add support for the /g modifier to perltest.
3277    
3278     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3279     matches null strings.
3280    
3281     4. Fix perltest so that it doesn't do unwanted things when fed an empty
3282     pattern. Perl treats empty patterns specially - it reuses the most recent
3283     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3284     effect.
3285    
3286     5. The POSIX interface was broken in that it was just handing over the POSIX
3287     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3288     required a bigger vector, with some working space on the end. This means that
3289     the POSIX wrapper now has to get and free some memory, and copy the results.
3290    
3291 nigel 43 6. Added some simple autoconf support, placing the test data and the
3292     documentation in separate directories, re-organizing some of the
3293     information files, and making it build pcre-config (a GNU standard). Also added
3294     libtool support for building PCRE as a shared library, which is now the
3295     default.
3296 nigel 41
3297 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3298     09 are not valid octal constants. Single digits will be used for minor values
3299     less than 10.
3300    
3301     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3302     existing programs that set these in the POSIX interface can use PCRE without
3303     modification.
3304    
3305     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3306     return all that pcre_info() returns, plus additional data. The pcre_info()
3307     function is retained for compatibility, but is considered to be obsolete.
3308    
3309     10. Added experimental recursion feature (?R) to handle one common case that
3310     Perl 5.6 will be able to do with (?p{...}).
3311    
3312     11. Added support for POSIX character classes like [:alpha:], which Perl is
3313     adopting.
3314    
3315    
3316 nigel 39 Version 2.08 31-Aug-99
3317     ----------------------
3318    
3319     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3320     trying to match at the startoffset position, but instead was moving forward to
3321     the next newline as if a previous match had failed.
3322    
3323     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3324     and could get into a loop if a null string was matched other than at the start
3325     of the subject.
3326    
3327     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3328     be distinguished at compile time, and for completeness also added PCRE_DATE.
3329    
3330     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3331     in GnuWin32 environments.
3332    
3333    
3334 nigel 37 Version 2.07 29-Jul-99
3335     ----------------------
3336    
3337     1. The documentation is now supplied in plain text form and HTML as well as in
3338     the form of man page sources.
3339    
3340     2. C++ compilers don't like assigning (void *) values to other pointer types.
3341     In particular this affects malloc(). Although there is no problem in Standard
3342     C, I've put in casts to keep C++ compilers happy.
3343    
3344     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3345     should be (const char *).
3346    
3347     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3348     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3349     However, I haven't made this a standard facility. The documentation doesn't
3350     mention it, and the Makefile doesn't support it.
3351    
3352     5. The Makefile now contains an "install" target, with editable destinations at
3353     the top of the file. The pcretest program is not installed.
3354    
3355     6. pgrep -V now gives the PCRE version number and date.
3356    
3357     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3358     causing the entire string to be ignored, instead of just the last character.
3359    
3360     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3361     non-matching string, it can take a very, very long time, even for strings of
3362     quite modest length, because of the nested recursion. PCRE now does better in
3363     some of these cases. It does this by remembering the last required literal
3364     character in the pattern, and pre-searching the subject to ensure it is present
3365     before running the real match. In other words, it applies a heuristic to detect
3366     some types of certain failure quickly, and in the above example, if presented
3367     with a string that has no trailing " it gives "no match" very quickly.
3368    
3369     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3370     other alternatives are tried instead.
3371    
3372    
3373 nigel 35 Version 2.06 09-Jun-99
3374     ----------------------
3375    
3376     1. Change pcretest's output for amount of store used to show just the code
3377     space, because the remainder (the data block) varies in size between 32-bit and
3378     64-bit systems.
3379    
3380     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3381     start matching at. This allows lookbehinds to work when searching for multiple
3382     occurrences in a string.
3383    
3384     3. Added additional options to pcretest for testing multiple occurrences:
3385    
3386     /+ outputs the rest of the string that follows a match
3387     /g loops for multiple occurrences, using the new startoffset argument
3388     /G loops for multiple occurrences by passing an incremented pointer
3389    
3390     4. PCRE wasn't doing the "first character" optimization for patterns starting
3391     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3392     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3393     the letter 'x'. On long subject strings, this gives a significant speed-up.
3394    
3395    
3396 nigel 33 Version 2.05 21-Apr-99
3397     ----------------------
3398    
3399     1. Changed the type of magic_number from int to long int so that it works
3400     properly on 16-bit systems.
3401    
3402     2. Fixed a bug which caused patterns starting with .* not to work correctly
3403     when the subject string contained newline characters. PCRE was assuming
3404     anchoring for such patterns in all cases, which is not correct because .* will
3405     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3406     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3407     must be retried after every newline in the subject.
3408    
3409    
3410 nigel 31 Version 2.04 18-Feb-99
3411     ----------------------
3412    
3413     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3414     computation of the store needed to hold the pattern was incorrect (too large).
3415     If such patterns were nested a few deep, this could multiply and become a real
3416     problem.
3417    
3418     2. Added /M option to pcretest to show the memory requirement of a specific
3419     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3420    
3421     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3422     compiled in such a way that the backtracking after subsequent failure was
3423     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3424     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3425    
3426    
3427 nigel 29 Version 2.03 02-Feb-99
3428     ----------------------
3429    
3430     1. Fixed typo and small mistake in man page.
3431    
3432 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3433     LICENCE file containing the conditions.
3434 nigel 29
3435     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3436     Perl, that is the internal \ allows the delimiter to be included in the
3437     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3438     the final delimiter, add \ to the end of the pattern (to test the error).
3439    
3440     4. Added the convenience functions for extracting substrings after a successful
3441     match. Updated pcretest to make it able to test these functions.
3442    
3443    
3444 nigel 27 Version 2.02 14-Jan-99
3445     ----------------------
3446    
3447     1. Initialized the working variables associated with each extraction so that
3448     their saving and restoring doesn't refer to uninitialized store.
3449    
3450     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3451     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3452     fix the problem.
3453    
3454     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3455     calls, and wasn't printing the correct value for compiling calls. Increased the
3456     default value of LOOPREPEAT, and the number of significant figures in the
3457     times.
3458    
3459     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3460    
3461     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3462     a building problem on Windows NT with a FAT file system.
3463    
3464    
3465 nigel 25 Version 2.01 21-Oct-98
3466     ----------------------
3467    
3468     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3469     to character tables built by pcre_maketables() in the current locale. If NULL
3470     is passed, the default tables are used.
3471    
3472    
3473 nigel 23 Version 2.00 24-Sep-98
3474 nigel 21 ----------------------
3475    
3476 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3477     it any more.
3478    
3479     2. Allow quantification of (?>) groups, and make it work correctly.
3480    
3481     3. The first character computation wasn't working for (?>) groups.
3482    
3483     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3484     end of the subject) and add 5.005's \z, which really does match only at the
3485     very end of the subject.
3486    
3487     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3488    
3489     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3490     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3491     localized options. All options to pcre_study() were also removed.
3492    
3493     7. Add other new features from 5.005:
3494    
3495     $(?<= positive lookbehind
3496     $(?<! negative lookbehind
3497     (?imsx-imsx) added the unsetting capability
3498     such a setting is global if at outer level; local otherwise
3499     (?imsx-imsx:) non-capturing groups with option setting
3500     (?(cond)re|re) conditional pattern matching
3501    
3502     A backreference to itself in a repeated group matches the previous
3503     captured string.
3504    
3505     8. General tidying up of studying (both automatic and via "study")
3506     consequential on the addition of new assertions.
3507    
3508     9. As in 5.005, unlimited repeated groups that could match an empty substring
3509     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3510     runtime if any iteration does actually match an empty substring.
3511    
3512     10. Include the RunTest script in the distribution.
3513    
3514     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3515     discrepancies, some of which were old and were also with respect to 5.004. They
3516     have now been fixed.
3517    
3518    
3519     Version 1.09 28-Apr-98
3520     ----------------------
3521    
3522 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3523     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3524     program crashes, or just wrong answers. This did not apply to negated classes
3525     containing more than one character, or to minima other than one.
3526    
3527    
3528 nigel 19 Version 1.08 27-Mar-98
3529     ----------------------
3530    
3531     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3532    
3533     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3534     latter must appear before anything that relies on it in the pattern.
3535    
3536    
3537 nigel 17 Version 1.07 16-Feb-98
3538     ----------------------
3539    
3540     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3541     repeat of a potentially empty string).
3542    
3543    
3544 nigel 15 Version 1.06 23-Jan-98
3545     ----------------------
3546    
3547     1. Added Markus Oberhumer's little patches for C++.
3548    
3549     2. Literal strings longer than 255 characters were broken.
3550    
3551    
3552 nigel 13 Version 1.05 23-Dec-97
3553     ----------------------
3554    
3555     1. Negated character classes containing more than one character were failing if
3556     PCRE_CASELESS was set at run time.
3557    
3558    
3559 nigel 11 Version 1.04 19-Dec-97
3560     ----------------------
3561    
3562     1. Corrected the man page, where some "const" qualifiers had been omitted.
3563    
3564     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3565     input syntax.
3566    
3567     3. Fixed memory leak which occurred when a regex with back references was
3568     matched with an offsets vector that wasn't big enough. The temporary memory
3569     that is used in this case wasn't being freed if the match failed.
3570    
3571     4. Tidied pcretest to ensure it frees memory that it gets.
3572    
3573     5. Temporary memory was being obtained in the case where the passed offsets
3574     vector was exactly big enough.
3575    
3576     6. Corrected definition of offsetof() from change 5 below.
3577    
3578     7. I had screwed up change 6 below and broken the rules for the use of
3579     setjmp(). Now fixed.
3580    
3581    
3582 nigel 9 Version 1.03 18-Dec-97
3583     ----------------------
3584    
3585     1. A erroneous regex with a missing opening parenthesis was correctly
3586     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3587     on some systems.
3588    
3589     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3590     it was reported that one broken compiler failed on the former because "code" is
3591     also an independent variable.
3592    
3593     3. The erroneous regex a[]b caused an array overrun reference.
3594    
3595     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3596     fail on data ending with that character. (It was going on too far, and checking
3597     the next character, typically a binary zero.) This was specific to the
3598     optimized code for single-character negative classes.
3599    
3600     5. Added a contributed patch from the TIN world which does the following:
3601    
3602     + Add an undef for memmove, in case the the system defines a macro for it.
3603    
3604     + Add a definition of offsetof(), in case there isn't one. (I don't know
3605     the reason behind this - offsetof() is part of the ANSI standard - but
3606     it does no harm).
3607    
3608     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3609     most of the places where whitespace preceded '#'. I have given up and
3610     allowed the remaining 2 cases to be at the margin.
3611    
3612     + Rename some variables in pcre to eliminate shadowing. This seems very
3613     pedantic, but does no harm, of course.
3614    
3615     6. Moved the call to setjmp() into its own function, to get rid of warnings
3616     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3617    
3618     7. Constructs such as \d{8,} were compiling into the equivalent of
3619 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3620 nigel 9 outcome, but in this particular case used more store than had been allocated,
3621     which caused the bug to be discovered because it threw up an internal error.
3622    
3623     8. The debugging code in both pcre and pcretest for outputting the compiled
3624     form of a regex was going wrong in the case of back references followed by
3625     curly-bracketed repeats.
3626    
3627    
3628 nigel 7 Version 1.02 12-Dec-97
3629     ----------------------
3630    
3631     1. Typos in pcre.3 and comments in the source fixed.
3632    
3633     2. Applied a contributed patch to get rid of places where it used to remove
3634     'const' from variables, and fixed some signed/unsigned and uninitialized
3635     variable warnings.
3636    
3637     3. Added the "runtest" target to Makefile.
3638    
3639     4. Set default compiler flag to -O2 rather than just -O.
3640    
3641    
3642 nigel 5 Version 1.01 19-Nov-97
3643     ----------------------
3644    
3645     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3646     like /([ab]*)*/, that is, for classes with more than one character in them.
3647    
3648     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3649     as /((?>a*))*/ (a PCRE_EXTRA facility).
3650    
3651    
3652     Version 1.00 18-Nov-97
3653     ----------------------
3654    
3655     1. Added compile-time macros to support systems such as SunOS4 which don't have
3656     memmove() or strerror() but have other things that can be used instead.
3657    
3658     2. Arranged that "make clean" removes the executables.
3659    
3660    
3661 nigel 3 Version 0.99 27-Oct-97
3662     ----------------------
3663    
3664     1. Fixed bug in code for optimizing classes with only one character. It was
3665     initializing a 32-byte map regardless, which could cause it to run off the end
3666     of the memory it had got.
3667    
3668     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3669    
3670    
3671     Version 0.98 22-Oct-97
3672     ----------------------
3673    
3674     1. Fixed bug in code for handling temporary memory usage when there are more
3675     back references than supplied space in the ovector. This could cause segfaults.
3676    
3677    
3678     Version 0.97 21-Oct-97
3679     ----------------------
3680    
3681     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3682    
3683     2. Optimized negated single characters not to use a bit map.
3684    
3685     3. Brought error texts together as macro definitions; clarified some of them;
3686     fixed one that was wrong - it said "range out of order" when it meant "invalid
3687     escape sequence".
3688    
3689     4. Changed some char * arguments to const char *.
3690    
3691     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3692    
3693     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3694     pcretest.
3695    
3696    
3697     Version 0.96 16-Oct-97
3698     ----------------------
3699    
3700     1. Added a simple "pgrep" utility to the distribution.
3701    
3702     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3703     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3704     where "ddd" means "one or more decimal digits".
3705    
3706     3. Fixed serious bug. If a pattern had a back reference, but the call to
3707     pcre_exec() didn't supply a large enough ovector to record the related
3708     identifying subpattern, the match always failed. PCRE now remembers the number
3709     of the largest back reference, and gets some temporary memory in which to save
3710     the offsets during matching if necessary, in order to ensure that
3711     backreferences always work.
3712    
3713     4. Increased the compatibility with Perl in a number of ways:
3714    
3715     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3716     to request this handling. The option can be set at compile or exec time.
3717    
3718     (b) $ matches before a terminating newline by default; an option
3719     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3720     mode). The option can be set at compile or exec time.
3721    
3722     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3723     the same as Perl's. If the decimal number it represents is less than 10
3724     or there aren't that many previous left capturing parentheses, an octal
3725     escape is read. Inside a character class, it's always an octal escape,
3726     even if it is a single digit.
3727    
3728     (d) An escaped but undefined alphabetic character is taken as a literal,
3729     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3730     escapes.
3731    
3732     (e) {0} is now permitted. (The previous item is removed from the compiled
3733     pattern).
3734    
3735     5. Changed all the names of code files so that the basic parts are no longer
3736     than 10 characters, and abolished the teeny "globals.c" file.
3737    
3738     6. Changed the handling of character classes; they are now done with a 32-byte
3739     bit map always.
3740    
3741     7. Added the -d and /D options to pcretest to make it possible to look at the
3742     internals of compilation without having to recompile pcre.
3743    
3744    
3745     Version 0.95 23-Sep-97
3746     ----------------------
3747    
3748     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3749     \x20 at the start of a run of normal characters. These were being treated as
3750     real characters, instead of the source characters being re-checked.
3751    
3752    
3753     Version 0.94 18-Sep-97
3754     ----------------------
3755    
3756     1. The functions are now thread-safe, with the caveat that the global variables
3757     containing pointers to malloc() and free() or alternative functions are the
3758     same for all threads.
3759