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Revision 723 - (show annotations)
Sat Oct 8 15:55:23 2011 UTC (8 years, 7 months ago) by ph10
File size: 216825 byte(s)
Error occurred while calculating annotation data.
Revert handling of atomic groups that do not include captures to the old way of 
handling, thus reducing stack usage.
1 ChangeLog for PCRE
2 ------------------
4 Version 8.20 23-Sep-2011
5 ------------------------
7 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
8 a POSIX class. After further experiments with Perl, which convinced me that
9 Perl has bugs and confusions, a closing square bracket is no longer allowed
10 in a POSIX name. This bug also affected patterns with classes that started
11 with full stops.
13 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
14 captured substring, but while checking the failing first alternative,
15 substring 1 is temporarily captured. If the output vector supplied to
16 pcre_exec() was not big enough for this capture, the yield of the function
17 was still zero ("insufficient space for captured substrings"). This cannot
18 be totally fixed without adding another stack variable, which seems a lot
19 of expense for a edge case. However, I have improved the situation in cases
20 such as /(a)(b)x|abc/ matched against "abc", where the return code
21 indicates that fewer than the maximum number of slots in the ovector have
22 been set.
24 3. Related to (2) above: when there are more back references in a pattern than
25 slots in the output vector, pcre_exec() uses temporary memory during
26 matching, and copies in the captures as far as possible afterwards. It was
27 using the entire output vector, but this conflicts with the specification
28 that only 2/3 is used for passing back captured substrings. Now it uses
29 only the first 2/3, for compatibility. This is, of course, another edge
30 case.
32 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
33 main code base, and can be used by building with --enable-jit. When this is
34 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
35 runtime --no-jit option is given.
37 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
38 ovector, the return from the function was zero, implying that there were
39 other matches that did not fit. The correct "exactly full" value is now
40 returned.
42 6. If a subpattern that was called recursively or as a subroutine contained
43 (*PRUNE) or any other control that caused it to give a non-standard return,
44 invalid errors such as "Error -26 (nested recursion at the same subject
45 position)" or even infinite loops could occur.
47 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
48 computing the minimum length on reaching *ACCEPT, and so ended up with the
49 wrong value of 1 rather than 0. Further investigation indicates that
50 computing a minimum subject length in the presence of *ACCEPT is difficult
51 (think back references, subroutine calls), and so I have changed the code
52 so that no minimum is registered for a pattern that contains *ACCEPT.
54 8. If (*THEN) was present in the first (true) branch of a conditional group,
55 it was not handled as intended. [But see 16 below.]
57 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
58 Sheri Pierce.
60 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
61 the first byte in a match must be "a".
63 11. Change 17 for 8.13 increased the recursion depth for patterns like
64 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
65 pattern contains any instances of (*THEN). If it does not, the old
66 optimizations are restored. It would be nice to do this on a per-group
67 basis, but at the moment that is not feasible.
69 12. In some environments, the output of pcretest -C is CRLF terminated. This
70 broke RunTest's code that checks for the link size. A single white space
71 after the value is now allowed for.
73 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
74 For "fr", it uses the Windows-specific input and output files.
76 14. If (*THEN) appeared in a group that was called recursively or as a
77 subroutine, it did not work as intended. [But see next item.]
79 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
80 pattern fragments (but not containing any | characters). If A and B are
81 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
82 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
83 D. In other words, Perl considers parentheses that do not contain any |
84 characters to be part of a surrounding alternative, whereas PCRE was
85 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
86 differently. PCRE now behaves in the same way as Perl, except in the case
87 of subroutine/recursion calls such as (?1) which have in any case always
88 been different (but PCRE had them first :-).
90 16. Related to 15 above: Perl does not treat the | in a conditional group as
91 creating alternatives. Such a group is treated in the same way as an
92 ordinary group without any | characters when processing (*THEN). PCRE has
93 been changed to match Perl's behaviour.
95 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
96 RunGrepTest script failed.
98 18. Change 22 for version 13 caused atomic groups to use more stack. This is
99 inevitable for groups that contain captures, but it can lead to a lot of
100 stack use in large patterns. The old behaviour has been restored for atomic
101 groups that do not contain any capturing parentheses.
104 Version 8.13 16-Aug-2011
105 ------------------------
107 1. The Unicode data tables have been updated to Unicode 6.0.0.
109 2. Two minor typos in pcre_internal.h have been fixed.
111 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
112 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
113 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
115 4. There were a number of related bugs in the code for matching backrefences
116 caselessly in UTF-8 mode when codes for the characters concerned were
117 different numbers of bytes. For example, U+023A and U+2C65 are an upper
118 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
119 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
120 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
121 2-byte code at the end of the subject (it thought there wasn't enough data
122 left).
124 5. Comprehensive information about what went wrong is now returned by
125 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
126 as the output vector has at least 2 elements. The offset of the start of
127 the failing character and a reason code are placed in the vector.
129 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
130 now returned is for the first byte of the failing character, instead of the
131 last byte inspected. This is an incompatible change, but I hope it is small
132 enough not to be a problem. It makes the returned offset consistent with
133 pcre_exec() and pcre_dfa_exec().
135 7. pcretest now gives a text phrase as well as the error number when
136 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
137 failure, the offset and reason code are output.
139 8. When \R was used with a maximizing quantifier it failed to skip backwards
140 over a \r\n pair if the subsequent match failed. Instead, it just skipped
141 back over a single character (\n). This seems wrong (because it treated the
142 two characters as a single entity when going forwards), conflicts with the
143 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
144 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
145 has been changed.
147 9. Some internal refactoring has changed the processing so that the handling
148 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
149 time (the PCRE_DOTALL option was changed this way some time ago: version
150 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
151 which was always a bit of a fudge. It also means that there is one less
152 argument for the match() function, which reduces its stack requirements
153 slightly. This change also fixes an incompatibility with Perl: the pattern
154 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
156 10. More internal refactoring has drastically reduced the number of recursive
157 calls to match() for possessively repeated groups such as (abc)++ when
158 using pcre_exec().
160 11. While implementing 10, a number of bugs in the handling of groups were
161 discovered and fixed:
163 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
164 (a|)*(?1) gave a compile-time internal error.
165 ((a|)+)+ did not notice that the outer group could match an empty string.
166 (^a|^)+ was not marked as anchored.
167 (.*a|.*)+ was not marked as matching at start or after a newline.
169 12. Yet more internal refactoring has removed another argument from the match()
170 function. Special calls to this function are now indicated by setting a
171 value in a variable in the "match data" data block.
173 13. Be more explicit in pcre_study() instead of relying on "default" for
174 opcodes that mean there is no starting character; this means that when new
175 ones are added and accidentally left out of pcre_study(), testing should
176 pick them up.
178 14. The -s option of pcretest has been documented for ages as being an old
179 synonym of -m (show memory usage). I have changed it to mean "force study
180 for every regex", that is, assume /S for every regex. This is similar to -i
181 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
182 using it. It makes it easier to run collections of tests with and without
183 study enabled, and thereby test pcre_study() more easily. All the standard
184 tests are now run with and without -s (but some patterns can be marked as
185 "never study" - see 20 below).
187 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
188 restoration of the capturing data to the outer values was not happening
189 correctly.
191 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
192 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
193 pattern had matched an empty string, and so incorrectly returned a no
194 match.
196 17. There was optimizing code for the last branch of non-capturing parentheses,
197 and also for the obeyed branch of a conditional subexpression, which used
198 tail recursion to cut down on stack usage. Unfortunately, now that there is
199 the possibility of (*THEN) occurring in these branches, tail recursion is
200 no longer possible because the return has to be checked for (*THEN). These
201 two optimizations have therefore been removed. [But see 8.20/11 above.]
203 18. If a pattern containing \R was studied, it was assumed that \R always
204 matched two bytes, thus causing the minimum subject length to be
205 incorrectly computed because \R can also match just one byte.
207 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
208 was incorrectly computed.
210 20. If /S is present twice on a test pattern in pcretest input, it now
211 *disables* studying, thereby overriding the use of -s on the command line
212 (see 14 above). This is necessary for one or two tests to keep the output
213 identical in both cases.
215 21. When (*ACCEPT) was used in an assertion that matched an empty string and
216 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
218 22. When an atomic group that contained a capturing parenthesis was
219 successfully matched, but the branch in which it appeared failed, the
220 capturing was not being forgotten if a higher numbered group was later
221 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
222 group 1 to "a", when in fact it should be unset. This applied to multi-
223 branched capturing and non-capturing groups, repeated or not, and also to
224 positive assertions (capturing in negative assertions does not happen
225 in PCRE) and also to nested atomic groups.
227 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
228 subject after a captured substring, to make it easier to tell which of a
229 number of identical substrings has been captured.
231 24. The way atomic groups are processed by pcre_exec() has been changed so that
232 if they are repeated, backtracking one repetition now resets captured
233 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
234 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
235 "aaa". Previously, it would have been "a". As part of this code
236 refactoring, the way recursive calls are handled has also been changed.
238 25. If an assertion condition captured any substrings, they were not passed
239 back unless some other capturing happened later. For example, if
240 (?(?=(a))a) was matched against "a", no capturing was returned.
242 26. When studying a pattern that contained subroutine calls or assertions,
243 the code for finding the minimum length of a possible match was handling
244 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
245 group 1 called group 2 while simultaneously a separate group 2 called group
246 1). A stack overflow occurred in this case. I have fixed this by limiting
247 the recursion depth to 10.
249 27. Updated RunTest.bat in the distribution to the version supplied by Tom
250 Fortmann. This supports explicit test numbers on the command line, and has
251 argument validation and error reporting.
253 28. An instance of \X with an unlimited repeat could fail if at any point the
254 first character it looked at was a mark character.
256 29. Some minor code refactoring concerning Unicode properties and scripts
257 should reduce the stack requirement of match() slightly.
259 30. Added the '=' option to pcretest to check the setting of unused capturing
260 slots at the end of the pattern, which are documented as being -1, but are
261 not included in the return count.
263 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
264 compiled something random. Now it gives a compile-time error (as does
265 Perl).
267 32. A *MARK encountered during the processing of a positive assertion is now
268 recorded and passed back (compatible with Perl).
270 33. If --only-matching or --colour was set on a pcregrep call whose pattern
271 had alternative anchored branches, the search for a second match in a line
272 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
273 matched the line "0102" twice. The same bug affected patterns that started
274 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
275 twice.
277 34. Previously, PCRE did not allow quantification of assertions. However, Perl
278 does, and because of capturing effects, quantifying parenthesized
279 assertions may at times be useful. Quantifiers are now allowed for
280 parenthesized assertions.
282 35. A minor code tidy in pcre_compile() when checking options for \R usage.
284 36. \g was being checked for fancy things in a character class, when it should
285 just be a literal "g".
287 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
288 appearance of a nested POSIX class supersedes an apparent external class.
289 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
290 unescaped square brackets may also appear as part of class names. For
291 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
292 more like Perl. (But see 8.20/1 above.)
294 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
295 was because it thought it was \N{name}, which is not supported).
297 39. Add minix to OS list not supporting the -S option in pcretest.
299 40. PCRE tries to detect cases of infinite recursion at compile time, but it
300 cannot analyze patterns in sufficient detail to catch mutual recursions
301 such as ((?1))((?2)). There is now a runtime test that gives an error if a
302 subgroup is called recursively as a subpattern for a second time at the
303 same position in the subject string. In previous releases this might have
304 been caught by the recursion limit, or it might have run out of stack.
306 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
307 happen only once. PCRE was, however incorrectly giving a compile time error
308 "recursive call could loop indefinitely" because it cannot analyze the
309 pattern in sufficient detail. The compile time test no longer happens when
310 PCRE is compiling a conditional subpattern, but actual runaway loops are
311 now caught at runtime (see 40 above).
313 42. It seems that Perl allows any characters other than a closing parenthesis
314 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
315 has been changed to be the same.
317 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
318 as not to get warnings when autogen.sh is called. Also changed
319 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
321 44. To help people who use pcregrep to scan files containing exceedingly long
322 lines, the following changes have been made:
324 (a) The default value of the buffer size parameter has been increased from
325 8K to 20K. (The actual buffer used is three times this size.)
327 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
328 PCRE is built.
330 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
331 to be set at run time.
333 (d) Numerical values in pcregrep options can be followed by K or M, for
334 example --buffer-size=50K.
336 (e) If a line being scanned overflows pcregrep's buffer, an error is now
337 given and the return code is set to 2.
339 45. Add a pointer to the latest mark to the callout data block.
341 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
342 partial match of an empty string instead of no match. This was specific to
343 the use of ".".
345 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
346 complete match instead of a partial match. This bug was dependent on both
347 the PCRE_UTF8 and PCRE_DOTALL options being set.
349 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
350 starting byte set, because \b was not being ignored.
353 Version 8.12 15-Jan-2011
354 ------------------------
356 1. Fixed some typos in the markup of the man pages, and wrote a script that
357 checks for such things as part of the documentation building process.
359 2. On a big-endian 64-bit system, pcregrep did not correctly process the
360 --match-limit and --recursion-limit options (added for 8.11). In
361 particular, this made one of the standard tests fail. (The integer value
362 went into the wrong half of a long int.)
364 3. If the --colour option was given to pcregrep with -v (invert match), it
365 did strange things, either producing crazy output, or crashing. It should,
366 of course, ignore a request for colour when reporting lines that do not
367 match.
369 4. Another pcregrep bug caused similar problems if --colour was specified with
370 -M (multiline) and the pattern match finished with a line ending.
372 5. In pcregrep, when a pattern that ended with a literal newline sequence was
373 matched in multiline mode, the following line was shown as part of the
374 match. This seems wrong, so I have changed it.
376 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
377 the check for further matches in the same line (so they could be coloured)
378 to overrun the end of the current line. If another match was found, it was
379 incorrectly shown (and then shown again when found in the next line).
381 7. If pcregrep was compiled under Windows, there was a reference to the
382 function pcregrep_exit() before it was defined. I am assuming this was
383 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
384 reported by a user. I've moved the definition above the reference.
387 Version 8.11 10-Dec-2010
388 ------------------------
390 1. (*THEN) was not working properly if there were untried alternatives prior
391 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
392 backtracked to try for "b" instead of moving to the next alternative branch
393 at the same level (in this case, to look for "c"). The Perl documentation
394 is clear that when (*THEN) is backtracked onto, it goes to the "next
395 alternative in the innermost enclosing group".
397 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
398 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
399 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
400 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
401 (*THEN).
403 3. If \s appeared in a character class, it removed the VT character from
404 the class, even if it had been included by some previous item, for example
405 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
406 of \s, but is part of the POSIX "space" class.)
408 4. A partial match never returns an empty string (because you can always
409 match an empty string at the end of the subject); however the checking for
410 an empty string was starting at the "start of match" point. This has been
411 changed to the "earliest inspected character" point, because the returned
412 data for a partial match starts at this character. This means that, for
413 example, /(?<=abc)def/ gives a partial match for the subject "abc"
414 (previously it gave "no match").
416 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
417 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
418 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
419 has an implication that the given string is incomplete (because a partial
420 match is preferred over a full match). For this reason, these items now
421 give a partial match in this situation. [Aside: previously, the one case
422 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
423 match rather than a full match, which was wrong by the old rules, but is
424 now correct.]
426 6. There was a bug in the handling of #-introduced comments, recognized when
427 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
428 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
429 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
430 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
431 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
432 places in pcre_compile().
434 7. Related to (6) above, when pcre_compile() was skipping #-introduced
435 comments when looking ahead for named forward references to subpatterns,
436 the only newline sequence it recognized was NL. It now handles newlines
437 according to the set newline convention.
439 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
440 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
441 cater for a lack of strerror(). These oversights have been fixed.
443 9. Added --match-limit and --recursion-limit to pcregrep.
445 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
447 11. When the -o option was used, pcregrep was setting a return code of 1, even
448 when matches were found, and --line-buffered was not being honoured.
450 12. Added an optional parentheses number to the -o and --only-matching options
451 of pcregrep.
453 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
454 can match an empty string. The code to do it in pcretest and pcredemo
455 needed fixing:
457 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
458 only one byte after an empty string match just before CRLF (this case
459 just got forgotten; "any" and "anycrlf" were OK).
461 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
462 mode when an empty string match preceded an ASCII character followed by
463 a non-ASCII character. (The code for advancing by one character rather
464 than one byte was nonsense.)
466 (c) The pcredemo.c sample program did not have any code at all to handle
467 the cases when CRLF is a valid newline sequence.
469 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
470 as a starting offset was within the subject string. There is now a new
471 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
472 negative or greater than the length of the string. In order to test this,
473 pcretest is extended to allow the setting of negative starting offsets.
475 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
476 starting offset points to the beginning of a UTF-8 character was
477 unnecessarily clumsy. I tidied it up.
479 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
480 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
482 17. Nobody had reported that the --include_dir option, which was added in
483 release 7.7 should have been called --include-dir (hyphen, not underscore)
484 for compatibility with GNU grep. I have changed it to --include-dir, but
485 left --include_dir as an undocumented synonym, and the same for
486 --exclude-dir, though that is not available in GNU grep, at least as of
487 release 2.5.4.
489 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
490 characters from a string of bytes) have been redefined so as not to use
491 loops, in order to improve performance in some environments. At the same
492 time, I abstracted some of the common code into auxiliary macros to save
493 repetition (this should not affect the compiled code).
495 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
496 compile-time error is now given if \c is not followed by an ASCII
497 character, that is, a byte less than 128. (In EBCDIC mode, the code is
498 different, and any byte value is allowed.)
500 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
501 START_OPTIMIZE option, which is now allowed at compile time - but just
502 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
503 to pcregrep and other applications that have no direct access to PCRE
504 options. The new /Y option in pcretest sets this option when calling
505 pcre_compile().
507 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
508 back references. Groups containing recursive back references were forced to
509 be atomic by that change, but in the case of named groups, the amount of
510 memory required was incorrectly computed, leading to "Failed: internal
511 error: code overflow". This has been fixed.
513 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
514 pcretest.c, to avoid build problems in some Borland environments.
517 Version 8.10 25-Jun-2010
518 ------------------------
520 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
521 THEN.
523 2. (*ACCEPT) was not working when inside an atomic group.
525 3. Inside a character class, \B is treated as a literal by default, but
526 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
527 causes the error). The code is unchanged, but I tidied the documentation.
529 4. Inside a character class, PCRE always treated \R and \X as literals,
530 whereas Perl faults them if its -w option is set. I have changed PCRE so
531 that it faults them when PCRE_EXTRA is set.
533 5. Added support for \N, which always matches any character other than
534 newline. (It is the same as "." when PCRE_DOTALL is not set.)
536 6. When compiling pcregrep with newer versions of gcc which may have
537 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
538 declared with attribute warn_unused_result" were given. Just casting the
539 result to (void) does not stop the warnings; a more elaborate fudge is
540 needed. I've used a macro to implement this.
542 7. Minor change to pcretest.c to avoid a compiler warning.
544 8. Added four artifical Unicode properties to help with an option to make
545 \s etc use properties (see next item). The new properties are: Xan
546 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
548 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
549 use Unicode properties. (*UCP) at the start of a pattern can be used to set
550 this option. Modified pcretest to add /W to test this facility. Added
551 REG_UCP to make it available via the POSIX interface.
553 10. Added --line-buffered to pcregrep.
555 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
556 studied, and the match started with a letter with a code point greater than
557 127 whose first byte was different to the first byte of the other case of
558 the letter, the other case of this starting letter was not recognized
559 (#976).
561 12. If a pattern that was studied started with a repeated Unicode property
562 test, for example, \p{Nd}+, there was the theoretical possibility of
563 setting up an incorrect bitmap of starting bytes, but fortunately it could
564 not have actually happened in practice until change 8 above was made (it
565 added property types that matched character-matching opcodes).
567 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
568 possible starting bytes for non-anchored patterns.
570 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
571 \R, and also a number of cases that involve Unicode properties, both
572 explicit and implicit when PCRE_UCP is set.
574 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
575 input, it could crash or give wrong results if characters with values
576 greater than 0xc0 were present in the subject string. (Detail: it assumed
577 UTF-8 input when processing these items.)
579 16. Added a lot of (int) casts to avoid compiler warnings in systems where
580 size_t is 64-bit (#991).
582 17. Added a check for running out of memory when PCRE is compiled with
583 --disable-stack-for-recursion (#990).
585 18. If the last data line in a file for pcretest does not have a newline on
586 the end, a newline was missing in the output.
588 19. The default pcre_chartables.c file recognizes only ASCII characters (values
589 less than 128) in its various bitmaps. However, there is a facility for
590 generating tables according to the current locale when PCRE is compiled. It
591 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
592 characters, are recognized by isspace() and therefore were getting set in
593 these tables, and indeed these tables seem to approximate to ISO 8859. This
594 caused a problem in UTF-8 mode when pcre_study() was used to create a list
595 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
596 which of course cannot start UTF-8 characters. I have changed the code so
597 that only real ASCII characters (less than 128) and the correct starting
598 bytes for UTF-8 encodings are set for characters greater than 127 when in
599 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
600 altogether.)
602 20. Added the /T option to pcretest so as to be able to run tests with non-
603 standard character tables, thus making it possible to include the tests
604 used for 19 above in the standard set of tests.
606 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
607 reference to a subpattern the other side of a comment that contains an
608 opening parenthesis caused either an internal compiling error, or a
609 reference to the wrong subpattern.
612 Version 8.02 19-Mar-2010
613 ------------------------
615 1. The Unicode data tables have been updated to Unicode 5.2.0.
617 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
618 configured.
620 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
621 original author of that file, following a query about its status.
623 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
624 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
626 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
627 quantifier applied to a forward-referencing subroutine call, could compile
628 incorrect code or give the error "internal error: previously-checked
629 referenced subpattern not found".
631 6. Both MS Visual Studio and Symbian OS have problems with initializing
632 variables to point to external functions. For these systems, therefore,
633 pcre_malloc etc. are now initialized to local functions that call the
634 relevant global functions.
636 7. There were two entries missing in the vectors called coptable and poptable
637 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
638 I've fixed the data, and added a kludgy way of testing at compile time that
639 the lengths are correct (equal to the number of opcodes).
641 8. Following on from 7, I added a similar kludge to check the length of the
642 eint vector in pcreposix.c.
644 9. Error texts for pcre_compile() are held as one long string to avoid too
645 much relocation at load time. To find a text, the string is searched,
646 counting zeros. There was no check for running off the end of the string,
647 which could happen if a new error number was added without updating the
648 string.
650 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
652 11. \K was not working if it appeared in an atomic group or in a group that
653 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
654 \K is "not well defined" if used in an assertion. PCRE now accepts it if
655 the assertion is positive, but not if it is negative.
657 12. Change 11 fortuitously reduced the size of the stack frame used in the
658 "match()" function of pcre_exec.c by one pointer. Forthcoming
659 implementation of support for (*MARK) will need an extra pointer on the
660 stack; I have reserved it now, so that the stack frame size does not
661 decrease.
663 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
664 item in branch that calls a recursion is a subroutine call - as in the
665 second branch in the above example - was incorrectly given the compile-
666 time error "recursive call could loop indefinitely" because pcre_compile()
667 was not correctly checking the subroutine for matching a non-empty string.
669 14. The checks for overrunning compiling workspace could trigger after an
670 overrun had occurred. This is a "should never occur" error, but it can be
671 triggered by pathological patterns such as hundreds of nested parentheses.
672 The checks now trigger 100 bytes before the end of the workspace.
674 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
677 Version 8.01 19-Jan-2010
678 ------------------------
680 1. If a pattern contained a conditional subpattern with only one branch (in
681 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
682 computed the wrong minimum data length (which is of course zero for such
683 subpatterns). This could cause incorrect "no match" results.
685 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
686 the pattern is reset in the first branch, pcre_compile() failed with
687 "internal error: code overflow at offset...". This happened only when
688 the reset was to the original external option setting. (An optimization
689 abstracts leading options settings into an external setting, which was the
690 cause of this.)
692 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
693 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
694 assertion pattern did not match (meaning that the assertion was true), it
695 was incorrectly treated as false if the SKIP had been reached during the
696 matching. This also applied to assertions used as conditions.
698 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
699 assertion subpattern, including such a pattern used as a condition,
700 unpredictable results occurred, instead of the error return
703 5. The C++ GlobalReplace function was not working like Perl for the special
704 situation when an empty string is matched. It now does the fancy magic
705 stuff that is necessary.
707 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
708 removed. (These were left over from very, very early versions of PCRE.)
710 7. Some cosmetic changes to the code to make life easier when compiling it
711 as part of something else:
713 (a) Change DEBUG to PCRE_DEBUG.
715 (b) In pcre_compile(), rename the member of the "branch_chain" structure
716 called "current" as "current_branch", to prevent a collision with the
717 Linux macro when compiled as a kernel module.
719 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
720 prevent a collision with the Linux macro when compiled as a kernel
721 module.
723 8. In pcre_compile() there are some checks for integer overflows that used to
724 cast potentially large values to (double). This has been changed to that
725 when building, a check for int64_t is made, and if it is found, it is used
726 instead, thus avoiding the use of floating point arithmetic. (There is no
727 other use of FP in PCRE.) If int64_t is not found, the fallback is to
728 double.
730 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
731 2005 (difference between two addresses compared to an unsigned value).
733 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
734 custom one, because of the following reported problem in Windows:
736 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
737 under Win32.
738 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
739 therefore missing the function definition.
740 - The compiler thus generates a "C" signature for the test function.
741 - The linker fails to find the "C" function.
742 - PCRE fails to configure if asked to do so against libbz2.
744 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
745 messages were output:
747 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
748 rerunning libtoolize, to keep the correct libtool macros in-tree.
749 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
751 I have done both of these things.
753 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
754 most of the time, it *can* run out if it is given a pattern that contains a
755 runaway infinite recursion. I updated the discussion in the pcrestack man
756 page.
758 13. Now that we have gone to the x.xx style of version numbers, the minor
759 version may start with zero. Using 08 or 09 is a bad idea because users
760 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
761 interpreted as invalid octal numbers. I've updated the previous comment in
762 configure.ac, and also added a check that gives an error if 08 or 09 are
763 used.
765 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
766 causing partial matching to fail when the end of the subject matched \W
767 in a UTF-8 pattern where \W was quantified with a minimum of 3.
769 15. There were some discrepancies between the declarations in pcre_internal.h
770 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
771 their definitions. The declarations used "const uschar *" and the
772 definitions used USPTR. Even though USPTR is normally defined as "const
773 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
774 reported that: "This difference in casting confuses some C++ compilers, for
775 example, SunCC recognizes above declarations as different functions and
776 generates broken code for hbpcre." I have changed the declarations to use
777 USPTR.
779 16. GNU libtool is named differently on some systems. The autogen.sh script now
780 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
781 (FreeBSD).
783 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
784 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
785 comment: "Figure out how to create a longlong from a string: strtoll and
786 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
787 instance, but it only takes 2 args instead of 3!"
789 18. A subtle bug concerned with back references has been fixed by a change of
790 specification, with a corresponding code fix. A pattern such as
791 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
792 refers, was giving matches when it shouldn't. For example, xa=xaaa would
793 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
794 same bug. Such groups have to be quantified to be useful, or contained
795 inside another quantified group. (If there's no repetition, the reference
796 can never match.) The problem arises because, having left the group and
797 moved on to the rest of the pattern, a later failure that backtracks into
798 the group uses the captured value from the final iteration of the group
799 rather than the correct earlier one. I have fixed this in PCRE by forcing
800 any group that contains a reference to itself to be an atomic group; that
801 is, there cannot be any backtracking into it once it has completed. This is
802 similar to recursive and subroutine calls.
805 Version 8.00 19-Oct-09
806 ----------------------
808 1. The table for translating pcre_compile() error codes into POSIX error codes
809 was out-of-date, and there was no check on the pcre_compile() error code
810 being within the table. This could lead to an OK return being given in
811 error.
813 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
814 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
815 in a Windows environment.
817 3. The pcregrep --count option prints the count for each file even when it is
818 zero, as does GNU grep. However, pcregrep was also printing all files when
819 --files-with-matches was added. Now, when both options are given, it prints
820 counts only for those files that have at least one match. (GNU grep just
821 prints the file name in this circumstance, but including the count seems
822 more useful - otherwise, why use --count?) Also ensured that the
823 combination -clh just lists non-zero counts, with no names.
825 4. The long form of the pcregrep -F option was incorrectly implemented as
826 --fixed_strings instead of --fixed-strings. This is an incompatible change,
827 but it seems right to fix it, and I didn't think it was worth preserving
828 the old behaviour.
830 5. The command line items --regex=pattern and --regexp=pattern were not
831 recognized by pcregrep, which required --regex pattern or --regexp pattern
832 (with a space rather than an '='). The man page documented the '=' forms,
833 which are compatible with GNU grep; these now work.
835 6. No libpcreposix.pc file was created for pkg-config; there was just
836 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
838 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
839 when UCP support is not needed, by modifying the Python script that
840 generates it from Unicode data files. This should not matter if the module
841 is correctly used as a library, but I received one complaint about 50K of
842 unwanted data. My guess is that the person linked everything into his
843 program rather than using a library. Anyway, it does no harm.
845 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
846 was a minimum greater than 1 for a wide character in a possessive
847 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
848 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
849 character. Chaos in the form of incorrect output or a compiling loop could
850 result.
852 9. The restrictions on what a pattern can contain when partial matching is
853 requested for pcre_exec() have been removed. All patterns can now be
854 partially matched by this function. In addition, if there are at least two
855 slots in the offset vector, the offset of the earliest inspected character
856 for the match and the offset of the end of the subject are set in them when
857 PCRE_ERROR_PARTIAL is returned.
859 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
860 synonymous with PCRE_PARTIAL, for backwards compatibility, and
861 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
862 and may be more useful for multi-segment matching.
864 11. Partial matching with pcre_exec() is now more intuitive. A partial match
865 used to be given if ever the end of the subject was reached; now it is
866 given only if matching could not proceed because another character was
867 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
868 string "Z", which now yields "no match" instead of "partial match". In the
869 case of pcre_dfa_exec(), "no match" is given if every matching path for the
870 final character ended with (*FAIL).
872 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
873 if the pattern had a "must contain" character that was already found in the
874 earlier partial match, unless partial matching was again requested. For
875 example, with the pattern /dog.(body)?/, the "must contain" character is
876 "g". If the first part-match was for the string "dog", restarting with
877 "sbody" failed. This bug has been fixed.
879 13. The string returned by pcre_dfa_exec() after a partial match has been
880 changed so that it starts at the first inspected character rather than the
881 first character of the match. This makes a difference only if the pattern
882 starts with a lookbehind assertion or \b or \B (\K is not supported by
883 pcre_dfa_exec()). It's an incompatible change, but it makes the two
884 matching functions compatible, and I think it's the right thing to do.
886 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
887 so that the demonstration program is easily available in environments where
888 PCRE has not been installed from source.
890 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
891 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
892 library.
894 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
895 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
896 is not the first non-POSIX option to be added. Clearly some people find
897 these options useful.
899 17. If a caller to the POSIX matching function regexec() passes a non-zero
900 value for nmatch with a NULL value for pmatch, the value of
901 nmatch is forced to zero.
903 18. RunGrepTest did not have a test for the availability of the -u option of
904 the diff command, as RunTest does. It now checks in the same way as
905 RunTest, and also checks for the -b option.
907 19. If an odd number of negated classes containing just a single character
908 interposed, within parentheses, between a forward reference to a named
909 subpattern and the definition of the subpattern, compilation crashed with
910 an internal error, complaining that it could not find the referenced
911 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
912 [The bug was that it was starting one character too far in when skipping
913 over the character class, thus treating the ] as data rather than
914 terminating the class. This meant it could skip too much.]
916 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
917 /g option in pcretest when the pattern contains \K, which makes it possible
918 to have an empty string match not at the start, even when the pattern is
919 anchored. Updated pcretest and pcredemo to use this option.
921 21. If the maximum number of capturing subpatterns in a recursion was greater
922 than the maximum at the outer level, the higher number was returned, but
923 with unset values at the outer level. The correct (outer level) value is
924 now given.
926 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
927 PCRE did not set those parentheses (unlike Perl). I have now found a way to
928 make it do so. The string so far is captured, making this feature
929 compatible with Perl.
931 23. The tests have been re-organized, adding tests 11 and 12, to make it
932 possible to check the Perl 5.10 features against Perl 5.10.
934 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
935 pattern matches a fixed length string. PCRE did not allow this; now it
936 does. Neither allows recursion.
938 25. I finally figured out how to implement a request to provide the minimum
939 length of subject string that was needed in order to match a given pattern.
940 (It was back references and recursion that I had previously got hung up
941 on.) This code has now been added to pcre_study(); it finds a lower bound
942 to the length of subject needed. It is not necessarily the greatest lower
943 bound, but using it to avoid searching strings that are too short does give
944 some useful speed-ups. The value is available to calling programs via
945 pcre_fullinfo().
947 26. While implementing 25, I discovered to my embarrassment that pcretest had
948 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
949 study optimizations had never been tested with that matching function.
950 Oops. What is worse, even when it was passed study data, there was a bug in
951 pcre_dfa_exec() that meant it never actually used it. Double oops. There
952 were also very few tests of studied patterns with pcre_dfa_exec().
954 27. If (?| is used to create subpatterns with duplicate numbers, they are now
955 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
956 on the other side of the coin, they are no longer allowed to have different
957 names, because these cannot be distinguished in PCRE, and this has caused
958 confusion. (This is a difference from Perl.)
960 28. When duplicate subpattern names are present (necessarily with different
961 numbers, as required by 27 above), and a test is made by name in a
962 conditional pattern, either for a subpattern having been matched, or for
963 recursion in such a pattern, all the associated numbered subpatterns are
964 tested, and the overall condition is true if the condition is true for any
965 one of them. This is the way Perl works, and is also more like the way
966 testing by number works.
969 Version 7.9 11-Apr-09
970 ---------------------
972 1. When building with support for bzlib/zlib (pcregrep) and/or readline
973 (pcretest), all targets were linked against these libraries. This included
974 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
975 libraries. This caused unwanted dependencies to be created. This problem
976 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
977 pcretest is linked with readline.
979 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
980 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
981 moved outside it again, because FALSE and TRUE are already defined in AIX,
982 but BOOL is not.
984 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
985 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
987 4. The pcregrep documentation said spaces were inserted as well as colons (or
988 hyphens) following file names and line numbers when outputting matching
989 lines. This is not true; no spaces are inserted. I have also clarified the
990 wording for the --colour (or --color) option.
992 5. In pcregrep, when --colour was used with -o, the list of matching strings
993 was not coloured; this is different to GNU grep, so I have changed it to be
994 the same.
996 6. When --colo(u)r was used in pcregrep, only the first matching substring in
997 each matching line was coloured. Now it goes on to look for further matches
998 of any of the test patterns, which is the same behaviour as GNU grep.
1000 7. A pattern that could match an empty string could cause pcregrep to loop; it
1001 doesn't make sense to accept an empty string match in pcregrep, so I have
1002 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1003 seems to be how GNU grep behaves.
1005 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1006 start or after a newline", because the conditional assertion was not being
1007 correctly handled. The rule now is that both the assertion and what follows
1008 in the first alternative must satisfy the test.
1010 9. If auto-callout was enabled in a pattern with a conditional group whose
1011 condition was an assertion, PCRE could crash during matching, both with
1012 pcre_exec() and pcre_dfa_exec().
1014 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1015 used for matching.
1017 11. Unicode property support in character classes was not working for
1018 characters (bytes) greater than 127 when not in UTF-8 mode.
1020 12. Added the -M command line option to pcretest.
1022 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1024 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1026 16. Added comments and documentation about mis-use of no_arg in the C++
1027 wrapper.
1029 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1030 from Martin Jerabek that uses macro names for all relevant character and
1031 string constants.
1033 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1034 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1035 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1036 these, but not everybody uses configure.
1038 19. A conditional group that had only one branch was not being correctly
1039 recognized as an item that could match an empty string. This meant that an
1040 enclosing group might also not be so recognized, causing infinite looping
1041 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1042 with the subject "ab", where knowledge that the repeated group can match
1043 nothing is needed in order to break the loop.
1045 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1046 exec(), but without supplying a callout function, matching went wrong.
1048 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1049 leak if the size of the offset vector was greater than 30. When the vector
1050 is smaller, the saved offsets during recursion go onto a local stack
1051 vector, but for larger vectors malloc() is used. It was failing to free
1052 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1053 error, in fact).
1055 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1056 heapframe that is used only when UTF-8 support is enabled. This caused no
1057 problem, but was untidy.
1059 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1060 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1061 included within another project.
1063 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1064 slightly modified by me:
1066 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1067 not building pcregrep.
1069 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1070 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1072 25. Forward references, both numeric and by name, in patterns that made use of
1073 duplicate group numbers, could behave incorrectly or give incorrect errors,
1074 because when scanning forward to find the reference group, PCRE was not
1075 taking into account the duplicate group numbers. A pattern such as
1076 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1078 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1079 the feature of a custom pointer more persuasive (as requested by a user).
1081 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1082 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1083 pre-defined.
1085 28. Added support for (*UTF8) at the start of a pattern.
1087 29. Arrange for flags added by the "release type" setting in CMake to be shown
1088 in the configuration summary.
1091 Version 7.8 05-Sep-08
1092 ---------------------
1094 1. Replaced UCP searching code with optimized version as implemented for Ad
1095 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1096 stage table and inline lookup instead of a function, giving speed ups of 2
1097 to 5 times on some simple patterns that I tested. Permission was given to
1098 distribute the MultiStage2.py script that generates the tables (it's not in
1099 the tarball, but is in the Subversion repository).
1101 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1102 scripts.
1104 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1105 a group with a zero qualifier. The result of the study could be incorrect,
1106 or the function might crash, depending on the pattern.
1108 4. Caseless matching was not working for non-ASCII characters in back
1109 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1110 It now works when Unicode Property Support is available.
1112 5. In pcretest, an escape such as \x{de} in the data was always generating
1113 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1114 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1115 truncation.
1117 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1119 7. Added two (int) casts to pcregrep when printing the difference of two
1120 pointers, in case they are 64-bit values.
1122 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1123 test 2 if it fails.
1125 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1126 and a #define of that name to empty if it is not externally set. This is to
1127 allow users of MSVC to set it if necessary.
1129 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1130 the convenience functions in the pcre_get.c source file.
1132 11. An option change at the start of a pattern that had top-level alternatives
1133 could cause overwriting and/or a crash. This command provoked a crash in
1134 some environments:
1136 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1138 This potential security problem was recorded as CVE-2008-2371.
1140 12. For a pattern where the match had to start at the beginning or immediately
1141 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1142 pcre_dfa_exec() could read past the end of the passed subject if there was
1143 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1144 pcretest so that it places the subject at the end of its malloc-ed buffer.
1146 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1147 exec() might read past the end of the data buffer in UTF-8 mode.
1149 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1150 the data contained the byte 0x85 as part of a UTF-8 character within its
1151 first line. This applied both to normal and DFA matching.
1153 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1154 /^[^d]*?$/8 failed to match "abc".
1156 16. Added a missing copyright notice to pcrecpp_internal.h.
1158 17. Make it more clear in the documentation that values returned from
1159 pcre_exec() in ovector are byte offsets, not character counts.
1161 18. Tidied a few places to stop certain compilers from issuing warnings.
1163 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1164 supplied by Stefan Weber. I made a further small update for 7.8 because
1165 there is a change of source arrangements: the pcre_searchfuncs.c module is
1166 replaced by pcre_ucd.c.
1169 Version 7.7 07-May-08
1170 ---------------------
1172 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1173 a string to a long long, pretend we don't even have a long long." This is
1174 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1176 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1177 pre-7.6 versions, which defined a global no_arg variable instead of putting
1178 it in the RE class. (See also #8 below.)
1180 3. Remove a line of dead code, identified by coverity and reported by Nuno
1181 Lopes.
1183 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1185 (1) The include/exclude patterns were being applied to the whole pathnames
1186 of files, instead of just to the final components.
1188 (2) If there was more than one level of directory, the subdirectories were
1189 skipped unless they satisfied the include/exclude conditions. This is
1190 inconsistent with GNU grep (and could even be seen as contrary to the
1191 pcregrep specification - which I improved to make it absolutely clear).
1192 The action now is always to scan all levels of directory, and just
1193 apply the include/exclude patterns to regular files.
1195 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1196 --exclude_dir in the tests to avoid scanning .svn directories.
1198 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1199 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1200 doesn't support NULs in patterns.
1202 7. Added some missing "const"s to declarations of static tables in
1203 pcre_compile.c and pcre_dfa_exec.c.
1205 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1206 caused by fix #2 above. (Subsequently also a second patch to fix the
1207 first patch. And a third patch - this was a messy problem.)
1209 9. Applied Craig's patch to remove the use of push_back().
1211 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1212 matching function regexec().
1214 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1215 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1216 references. PCRE supports relative numbers with this syntax (I don't think
1217 Oniguruma does).
1219 12. Previously, a group with a zero repeat such as (...){0} was completely
1220 omitted from the compiled regex. However, this means that if the group
1221 was called as a subroutine from elsewhere in the pattern, things went wrong
1222 (an internal error was given). Such groups are now left in the compiled
1223 pattern, with a new opcode that causes them to be skipped at execution
1224 time.
1226 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1227 to the way PCRE behaves:
1229 (a) A lone ] character is dis-allowed (Perl treats it as data).
1231 (b) A back reference to an unmatched subpattern matches an empty string
1232 (Perl fails the current match path).
1234 (c) A data ] in a character class must be notated as \] because if the
1235 first data character in a class is ], it defines an empty class. (In
1236 Perl it is not possible to have an empty class.) The empty class []
1237 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1238 The negative empty class [^] matches any one character, independently
1239 of the DOTALL setting.
1241 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1242 non-existent subpattern following a character class starting with ']' and
1243 containing () gave an internal compiling error instead of "reference to
1244 non-existent subpattern". Fortunately, when the pattern did exist, the
1245 compiled code was correct. (When scanning forwards to check for the
1246 existencd of the subpattern, it was treating the data ']' as terminating
1247 the class, so got the count wrong. When actually compiling, the reference
1248 was subsequently set up correctly.)
1250 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1251 it was being rejected as not supported by pcre_dfa_exec(), even though
1252 other assertions are supported. I have made pcre_dfa_exec() support
1253 (*FAIL).
1255 16. The implementation of 13c above involved the invention of a new opcode,
1256 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1257 cannot be changed at match time, I realized I could make a small
1258 improvement to matching performance by compiling OP_ALLANY instead of
1259 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1260 on the OP_ANY path.
1262 17. Compiling pcretest on Windows with readline support failed without the
1263 following two fixes: (1) Make the unistd.h include conditional on
1264 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1266 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1267 ncurses library to be included for pcretest when ReadLine support is
1268 requested, but also to allow for it to be overridden. This patch came from
1269 Daniel Bergström.
1271 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1272 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1273 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1274 spotting this.
1277 Version 7.6 28-Jan-08
1278 ---------------------
1280 1. A character class containing a very large number of characters with
1281 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1282 overflow.
1284 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1285 HAVE_LONG_LONG is not defined.
1287 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1288 bring them up to date and include new features. This patch includes:
1290 - Fixed PH's badly added libz and libbz2 support.
1291 - Fixed a problem with static linking.
1292 - Added pcredemo. [But later removed - see 7 below.]
1293 - Fixed dftables problem and added an option.
1294 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1296 - Added readline support for pcretest.
1297 - Added an listing of the option settings after cmake has run.
1299 4. A user submitted a patch to Makefile that makes it easy to create
1300 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1301 Makefile.am that cause it to include this special target, without
1302 affecting anything else. Note that the same mingw target plus all
1303 the other distribution libraries and programs are now supported
1304 when configuring with CMake (see 6 below) instead of with
1305 Configure/Make.
1307 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1308 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1309 exported in the Windows port". It has not yet been confirmed that the patch
1310 solves the problem, but it does no harm.
1312 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1313 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1314 with CMake, and also correct the comment about stack recursion.
1316 7. Remove the automatic building of pcredemo from the ./configure system and
1317 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1318 of a program that users should build themselves after PCRE is installed, so
1319 building it automatically is not really right. What is more, it gave
1320 trouble in some build environments.
1322 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1325 Version 7.5 10-Jan-08
1326 ---------------------
1328 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1329 values in parens when parsing an RE using the C++ wrapper."
1331 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1332 Characters greater than 255 were excluded from the class instead of being
1333 included.
1335 3. The same bug as (2) above applied to negated POSIX classes such as
1336 [:^space:].
1338 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1339 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1340 I have changed it.
1342 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1343 first named subpattern) and a construct such as (?&a) would reference the
1344 first named subpattern whose name started with "a" (in other words, the
1345 length check was missing). Both these problems are fixed. "Subpattern name
1346 expected" is now given for (?&) (a zero-length name), and this patch also
1347 makes it give the same error for \k'' (previously it complained that that
1348 was a reference to a non-existent subpattern).
1350 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1351 this is right because (?- can be followed by option settings as well as by
1352 digits. I have, however, made the messages clearer.
1354 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1355 than the number used in the conditional) now cause a compile-time error.
1356 This is actually not compatible with Perl, which accepts such patterns, but
1357 treats the conditional as always being FALSE (as PCRE used to), but it
1358 seems to me that giving a diagnostic is better.
1360 8. Change "alphameric" to the more common word "alphanumeric" in comments
1361 and messages.
1363 9. Fix two occurrences of "backslash" in comments that should have been
1364 "backspace".
1366 10. Remove two redundant lines of code that can never be obeyed (their function
1367 was moved elsewhere).
1369 11. The program that makes PCRE's Unicode character property table had a bug
1370 which caused it to generate incorrect table entries for sequences of
1371 characters that have the same character type, but are in different scripts.
1372 It amalgamated them into a single range, with the script of the first of
1373 them. In other words, some characters were in the wrong script. There were
1374 thirteen such cases, affecting characters in the following ranges:
1376 U+002b0 - U+002c1
1377 U+0060c - U+0060d
1378 U+0061e - U+00612
1379 U+0064b - U+0065e
1380 U+0074d - U+0076d
1381 U+01800 - U+01805
1382 U+01d00 - U+01d77
1383 U+01d9b - U+01dbf
1384 U+0200b - U+0200f
1385 U+030fc - U+030fe
1386 U+03260 - U+0327f
1387 U+0fb46 - U+0fbb1
1388 U+10450 - U+1049d
1390 12. The -o option (show only the matching part of a line) for pcregrep was not
1391 compatible with GNU grep in that, if there was more than one match in a
1392 line, it showed only the first of them. It now behaves in the same way as
1393 GNU grep.
1395 13. If the -o and -v options were combined for pcregrep, it printed a blank
1396 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1397 does the same. The return code can be used to tell if there were any
1398 non-matching lines.
1400 14. Added --file-offsets and --line-offsets to pcregrep.
1402 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1403 infinitely looping recursion. The bug was that positive lookaheads were not
1404 being skipped when checking for a possible empty match (negative lookaheads
1405 and both kinds of lookbehind were skipped).
1407 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1408 inclusion of <windows.h> to before rather than after the definition of
1409 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1411 17. Specifying a possessive quantifier with a specific limit for a Unicode
1412 character property caused pcre_compile() to compile bad code, which led at
1413 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1414 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1415 caused the error; without that there was no problem.
1417 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1419 19. Added --enable-pcretest-libreadline.
1421 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1422 RE::GlobalReplace(). As a result, the number of replacements returned was
1423 double what it should be. I removed one of the increments, but Craig sent a
1424 later patch that removed the other one (the right fix) and added unit tests
1425 that check the return values (which was not done before).
1427 21. Several CMake things:
1429 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1430 the names libpcre and libpcreposix, not just pcre and pcreposix.
1432 (2) The above change means that pcretest and pcregrep are now correctly
1433 linked with the newly-built libraries, not previously installed ones.
1437 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1438 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1439 UTF-8 newline character). The key issue is that the pattern starts .*;
1440 this means that the match must be either at the beginning, or after a
1441 newline. The bug was in the code for advancing after a failed match and
1442 checking that the new position followed a newline. It was not taking
1443 account of UTF-8 characters correctly.
1445 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1446 character classes. PCRE was not treating the sequence [:...:] as a
1447 character class unless the ... were all letters. Perl, however, seems to
1448 allow any characters between [: and :], though of course it rejects as
1449 unknown any "names" that contain non-letters, because all the known class
1450 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1451 for example, whereas PCRE did not - it did not recognize a POSIX character
1452 class. This seemed a bit dangerous, so the code has been changed to be
1453 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1454 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1455 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1456 Perl does, and where it didn't before.
1458 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1459 Windows environments %n is disabled by default.
1462 Version 7.4 21-Sep-07
1463 ---------------------
1465 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1466 means that a class such as [\s] counted as "explicit reference to CR or
1467 LF". That isn't really right - the whole point of the change was to try to
1468 help when there was an actual mention of one of the two characters. So now
1469 the change happens only if \r or \n (or a literal CR or LF) character is
1470 encountered.
1472 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1473 of both had grown to the point where there were only 3 bits left.
1474 Fortunately, there was spare space in the data structure, and so I have
1475 moved the internal flags into a new 16-bit field to free up more option
1476 bits.
1478 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1479 but did not set the internal JCHANGED flag - either of these is enough to
1480 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1481 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1482 start sets both bits.
1484 4. Added options (at build time, compile time, exec time) to change \R from
1485 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1487 5. doc/pcresyntax.html was missing from the distribution.
1489 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1490 compatibility, even though it is no longer used.
1492 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1493 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1494 windows.h file is present (where different names are used). [This was
1495 reversed later after testing - see 16 below.]
1497 8. Changed all #include <config.h> to #include "config.h". There were also
1498 some further <pcre.h> cases that I changed to "pcre.h".
1500 9. When pcregrep was used with the --colour option, it missed the line ending
1501 sequence off the lines that it output.
1503 10. It was pointed out to me that arrays of string pointers cause lots of
1504 relocations when a shared library is dynamically loaded. A technique of
1505 using a single long string with a table of offsets can drastically reduce
1506 these. I have refactored PCRE in four places to do this. The result is
1507 dramatic:
1509 Originally: 290
1510 After changing UCP table: 187
1511 After changing error message table: 43
1512 After changing table of "verbs" 36
1513 After changing table of Posix names 22
1515 Thanks to the folks working on Gregex for glib for this insight.
1517 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1518 unicode-properties was also set.
1520 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1522 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1523 checked only for CRLF.
1525 14. Added casts to pcretest.c to avoid compiler warnings.
1527 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1529 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1530 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1531 entirely. This removes changes made in 7 above.
1533 17. The CMake files have been updated, and there is now more information about
1534 building with CMake in the NON-UNIX-USE document.
1537 Version 7.3 28-Aug-07
1538 ---------------------
1540 1. In the rejigging of the build system that eventually resulted in 7.1, the
1541 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1542 brackets there is not right, since it causes compilers to look for an
1543 installed pcre.h, not the version that is in the source that is being
1544 compiled (which of course may be different). I have changed it back to:
1546 #include "pcre.h"
1548 I have a vague recollection that the change was concerned with compiling in
1549 different directories, but in the new build system, that is taken care of
1550 by the VPATH setting the Makefile.
1552 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1553 when the subject happened to end in the byte 0x85 (e.g. if the last
1554 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1555 characters but of course it shouldn't be taken as a newline when it is part
1556 of another character. The bug was that, for an unlimited repeat of . in
1557 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1558 characters when looking for a newline.
1560 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1562 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1563 in debug output.
1565 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1566 long printing in the pcrecpp unittest when running under MinGW.
1568 6. ESC_K was left out of the EBCDIC table.
1570 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1571 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1572 limit also applies to "virtual nesting" when a pattern is recursive, and in
1573 this case 1000 isn't so big. I have been able to remove this limit at the
1574 expense of backing off one optimization in certain circumstances. Normally,
1575 when pcre_exec() would call its internal match() function recursively and
1576 immediately return the result unconditionally, it uses a "tail recursion"
1577 feature to save stack. However, when a subpattern that can match an empty
1578 string has an unlimited repetition quantifier, it no longer makes this
1579 optimization. That gives it a stack frame in which to save the data for
1580 checking that an empty string has been matched. Previously this was taken
1581 from the 1000-entry workspace that had been reserved. So now there is no
1582 explicit limit, but more stack is used.
1584 8. Applied Daniel's patches to solve problems with the import/export magic
1585 syntax that is required for Windows, and which was going wrong for the
1586 pcreposix and pcrecpp parts of the library. These were overlooked when this
1587 problem was solved for the main library.
1589 9. There were some crude static tests to avoid integer overflow when computing
1590 the size of patterns that contain repeated groups with explicit upper
1591 limits. As the maximum quantifier is 65535, the maximum group length was
1592 set at 30,000 so that the product of these two numbers did not overflow a
1593 32-bit integer. However, it turns out that people want to use groups that
1594 are longer than 30,000 bytes (though not repeat them that many times).
1595 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1596 made it possible to implement the integer overflow checks in a much more
1597 dynamic way, which I have now done. The artificial limitation on group
1598 length has been removed - we now have only the limit on the total length of
1599 the compiled pattern, which depends on the LINK_SIZE setting.
1601 10. Fixed a bug in the documentation for get/copy named substring when
1602 duplicate names are permitted. If none of the named substrings are set, the
1603 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1604 empty string.
1606 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1607 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1608 because the ] is interpreted as the first data character and the
1609 terminating ] is not found. PCRE has been made compatible with Perl in this
1610 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1611 cause memory overwriting.
1613 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1614 string has been matched (to stop an infinite loop). It was not recognizing
1615 a conditional subpattern that could match an empty string if that
1616 subpattern was within another subpattern. For example, it looped when
1617 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1618 condition was not nested. This bug has been fixed.
1620 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1621 past the start of the subject in the presence of bytes with the top bit
1622 set, for example "\x8aBCD".
1624 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1625 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1627 14. Optimized (?!) to (*FAIL).
1629 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1630 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1631 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1632 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1633 does: it's just the validity check that is more restrictive.
1635 16. Inserted checks for integer overflows during escape sequence (backslash)
1636 processing, and also fixed erroneous offset values for syntax errors during
1637 backslash processing.
1639 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1640 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1642 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1643 caused an overrun.
1645 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1646 something other than just ASCII characters) inside a group that had an
1647 unlimited repeat caused a loop at compile time (while checking to see
1648 whether the group could match an empty string).
1650 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1651 [\P{Any}] did so. (Error in the code for printing property names.)
1653 21. An orphan \E inside a character class could cause a crash.
1655 22. A repeated capturing bracket such as (A)? could cause a wild memory
1656 reference during compilation.
1658 23. There are several functions in pcre_compile() that scan along a compiled
1659 expression for various reasons (e.g. to see if it's fixed length for look
1660 behind). There were bugs in these functions when a repeated \p or \P was
1661 present in the pattern. These operators have additional parameters compared
1662 with \d, etc, and these were not being taken into account when moving along
1663 the compiled data. Specifically:
1665 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1666 length.
1668 (b) An item such as \pL+ within a repeated group could cause crashes or
1669 loops.
1671 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1672 "reference to non-existent subpattern" error.
1674 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1676 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1677 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1679 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1681 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1682 character were causing crashes (broken optimization).
1684 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1685 \p or \P) caused a compile-time loop.
1687 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1688 break. For example, the unstudied pattern [\r\n]A does not match the string
1689 "\r\nA" because change 7.0/46 below moves the current point on by two
1690 characters after failing to match at the start. However, the pattern \nA
1691 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1692 the same is true. There doesn't seem any very clean way out of this, but
1693 what I have chosen to do makes the common cases work: PCRE now takes note
1694 of whether there can be an explicit match for \r or \n anywhere in the
1695 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1696 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1697 pattern has explicit CR or LF references.
1699 29. Added (*CR) etc for changing newline setting at start of pattern.
1702 Version 7.2 19-Jun-07
1703 ---------------------
1705 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1706 which is apparently normally available under Windows.
1708 2. Re-jig the pcregrep tests with different newline settings in an attempt
1709 to make them independent of the local environment's newline setting.
1711 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1713 4. Some of the "internals" tests were previously cut out when the link size
1714 was not 2, because the output contained actual offsets. The recent new
1715 "Z" feature of pcretest means that these can be cut out, making the tests
1716 usable with all link sizes.
1718 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1719 stack recursion. This gives a massive performance boost under BSD, but just
1720 a small improvement under Linux. However, it saves one field in the frame
1721 in all cases.
1723 6. Added more features from the forthcoming Perl 5.10:
1725 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1726 recursion call. It refers to the nth most recently opened parentheses.
1728 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1729 to be opened parentheses.
1731 (c) Conditions that refer to capturing parentheses can be specified
1732 relatively, for example, (?(-2)... or (?(+3)...
1734 (d) \K resets the start of the current match so that everything before
1735 is not part of it.
1737 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1739 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1740 reference syntax.
1742 (g) (?| introduces a group in which the numbering of parentheses in each
1743 alternative starts with the same number.
1745 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1747 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1750 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1751 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1752 for detecting groups that can match an empty string.
1754 9. A pattern with a very large number of alternatives (more than several
1755 hundred) was running out of internal workspace during the pre-compile
1756 phase, where pcre_compile() figures out how much memory will be needed. A
1757 bit of new cunning has reduced the workspace needed for groups with
1758 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1759 workspace instead of running out of the 4096 that are available.
1761 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1763 11. Applied patch from Google to remove an optimization that didn't quite work.
1764 The report of the bug said:
1766 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1767 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1768 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1770 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1771 it matched the wrong number of bytes.
1774 Version 7.1 24-Apr-07
1775 ---------------------
1777 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1778 that is more "standard", making use of automake and other Autotools. There
1779 is some re-arrangement of the files and adjustment of comments consequent
1780 on this.
1782 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1783 for recursive directory scanning broke on some systems because the files
1784 are not scanned in any specific order and on different systems the order
1785 was different. A call to "sort" has been inserted into RunGrepTest for the
1786 approprate test as a short-term fix. In the longer term there may be an
1787 alternative.
1789 3. I had an email from Eric Raymond about problems translating some of PCRE's
1790 man pages to HTML (despite the fact that I distribute HTML pages, some
1791 people do their own conversions for various reasons). The problems
1792 concerned the use of low-level troff macros .br and .in. I have therefore
1793 removed all such uses from the man pages (some were redundant, some could
1794 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1795 HTML has been updated to handle .nf/.fi and to complain if it encounters
1796 .br or .in.
1798 4. Updated comments in configure.ac that get placed in config.h.in and also
1799 arranged for config.h to be included in the distribution, with the name
1800 config.h.generic, for the benefit of those who have to compile without
1801 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1803 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1804 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1805 makevp.bat for the current PCRE, using the additional files
1806 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1808 6. A Windows user reported a minor discrepancy with test 2, which turned out
1809 to be caused by a trailing space on an input line that had got lost in his
1810 copy. The trailing space was an accident, so I've just removed it.
1812 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
1813 that is needed.
1815 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
1816 as "const" (a) because they are and (b) because it helps the PHP
1817 maintainers who have recently made a script to detect big data structures
1818 in the php code that should be moved to the .rodata section. I remembered
1819 to update Builducptable as well, so it won't revert if ucptable.h is ever
1820 re-created.
1822 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
1823 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
1824 order to be able to cut out the UTF-8 tables in the latter when UTF-8
1825 support is not required. This saves 1.5-2K of code, which is important in
1826 some applications.
1828 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
1829 so as not to refer to the tables, even though these functions will never be
1830 called when UTF-8 support is disabled. Otherwise there are problems with a
1831 shared library.
1833 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
1835 (a) It was defining its arguments as char * instead of void *.
1837 (b) It was assuming that all moves were upwards in memory; this was true
1838 a long time ago when I wrote it, but is no longer the case.
1840 The emulated memove() is provided for those environments that have neither
1841 memmove() nor bcopy(). I didn't think anyone used it these days, but that
1842 is clearly not the case, as these two bugs were recently reported.
1844 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
1845 and Detrail to create the HTML documentation, the .txt form of the man
1846 pages, and it removes trailing spaces from listed files. It also creates
1847 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
1848 case, it wraps all the #defines with #ifndefs. This script should be run
1849 before "make dist".
1851 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
1852 with Unicode property support.
1854 (a) For a maximizing quantifier, if the two different cases of the
1855 character were of different lengths in their UTF-8 codings (there are
1856 some cases like this - I found 11), and the matching function had to
1857 back up over a mixture of the two cases, it incorrectly assumed they
1858 were both the same length.
1860 (b) When PCRE was configured to use the heap rather than the stack for
1861 recursion during matching, it was not correctly preserving the data for
1862 the other case of a UTF-8 character when checking ahead for a match
1863 while processing a minimizing repeat. If the check also involved
1864 matching a wide character, but failed, corruption could cause an
1865 erroneous result when trying to check for a repeat of the original
1866 character.
1868 13. Some tidying changes to the testing mechanism:
1870 (a) The RunTest script now detects the internal link size and whether there
1871 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
1872 values substituted by "configure". (The RunGrepTest script already did
1873 this for UTF-8.) The configure.ac script no longer substitutes the
1874 relevant variables.
1876 (b) The debugging options /B and /D in pcretest show the compiled bytecode
1877 with length and offset values. This means that the output is different
1878 for different internal link sizes. Test 2 is skipped for link sizes
1879 other than 2 because of this, bypassing the problem. Unfortunately,
1880 there was also a test in test 3 (the locale tests) that used /B and
1881 failed for link sizes other than 2. Rather than cut the whole test out,
1882 I have added a new /Z option to pcretest that replaces the length and
1883 offset values with spaces. This is now used to make test 3 independent
1884 of link size. (Test 2 will be tidied up later.)
1886 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
1887 segmentation fault instead of returning the appropriate error message.
1889 15. In multiline mode when the newline sequence was set to "any", the pattern
1890 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
1891 This doesn't seem right; it now treats the CRLF combination as the line
1892 ending, and so does not match in that case. It's only a pattern such as ^$
1893 that would hit this one: something like ^ABC$ would have failed after \r
1894 and then tried again after \r\n.
1896 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
1897 in an attempt to make files that differ only in their line terminators
1898 compare equal. This works on Linux.
1900 17. Under certain error circumstances pcregrep might try to free random memory
1901 as it exited. This is now fixed, thanks to valgrind.
1903 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
1904 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
1905 was because its rules for how to advance for /g after matching an empty
1906 string at the end of a line did not allow for this case. They now check for
1907 it specially.
1909 20. pcretest is supposed to handle patterns and data of any length, by
1910 extending its buffers when necessary. It was getting this wrong when the
1911 buffer for a data line had to be extended.
1913 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
1914 CRLF as a newline sequence.
1916 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
1917 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
1918 I have nevertheless tidied it up.
1920 23. Added some casts to kill warnings from HP-UX ia64 compiler.
1922 24. Added a man page for pcre-config.
1925 Version 7.0 19-Dec-06
1926 ---------------------
1928 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
1929 moving to gcc 4.1.1.
1931 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
1932 sys/time.h, which is documented as needed for this function. It doesn't
1933 seem to matter on Linux, but it showed up on some releases of OS X.
1935 3. It seems that there are systems where bytes whose values are greater than
1936 127 match isprint() in the "C" locale. The "C" locale should be the
1937 default when a C program starts up. In most systems, only ASCII printing
1938 characters match isprint(). This difference caused the output from pcretest
1939 to vary, making some of the tests fail. I have changed pcretest so that:
1941 (a) When it is outputting text in the compiled version of a pattern, bytes
1942 other than 32-126 are always shown as hex escapes.
1944 (b) When it is outputting text that is a matched part of a subject string,
1945 it does the same, unless a different locale has been set for the match
1946 (using the /L modifier). In this case, it uses isprint() to decide.
1948 4. Fixed a major bug that caused incorrect computation of the amount of memory
1949 required for a compiled pattern when options that changed within the
1950 pattern affected the logic of the preliminary scan that determines the
1951 length. The relevant options are -x, and -i in UTF-8 mode. The result was
1952 that the computed length was too small. The symptoms of this bug were
1953 either the PCRE error "internal error: code overflow" from pcre_compile(),
1954 or a glibc crash with a message such as "pcretest: free(): invalid next
1955 size (fast)". Examples of patterns that provoked this bug (shown in
1956 pcretest format) are:
1958 /(?-x: )/x
1959 /(?x)(?-x: \s*#\s*)/
1960 /((?i)[\x{c0}])/8
1961 /(?i:[\x{c0}])/8
1963 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1964 is now done differently.
1966 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1967 wrapper classes; (b) implement a new function in the C++ scanner that is
1968 more efficient than the old way of doing things because it avoids levels of
1969 recursion in the regex matching; (c) add a paragraph to the documentation
1970 for the FullMatch() function.
1972 6. The escape sequence \n was being treated as whatever was defined as
1973 "newline". Not only was this contrary to the documentation, which states
1974 that \n is character 10 (hex 0A), but it also went horribly wrong when
1975 "newline" was defined as CRLF. This has been fixed.
1977 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1978 was being set to -1 for the "end of line" case (supposedly a value that no
1979 character can have). Though this value is never used (the check for end of
1980 line is "zero bytes in current character"), it caused compiler complaints.
1981 I've changed it to 0xffffffff.
1983 8. In pcre_version.c, the version string was being built by a sequence of
1984 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1985 string (as it is for production releases) called a macro with an empty
1986 argument. The C standard says the result of this is undefined. The gcc
1987 compiler treats it as an empty string (which was what was wanted) but it is
1988 reported that Visual C gives an error. The source has been hacked around to
1989 avoid this problem.
1991 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1992 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1993 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1994 of them did).
1996 10. Originally, pcretest opened its input and output without "b"; then I was
1997 told that "b" was needed in some environments, so it was added for release
1998 5.0 to both the input and output. (It makes no difference on Unix-like
1999 systems.) Later I was told that it is wrong for the input on Windows. I've
2000 now abstracted the modes into two macros, to make it easier to fiddle with
2001 them, and removed "b" from the input mode under Windows.
2003 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2005 12. Added -help and --help to pcretest as an official way of being reminded
2006 of the options.
2008 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2009 and pcrecpp.cc because they annoy compilers at high warning levels.
2011 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2013 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2014 scripts are not C programs :-) and which was not noticed because it works
2015 on Linux.
2017 16. pcretest is supposed to handle any length of pattern and data line (as one
2018 line or as a continued sequence of lines) by extending its input buffer if
2019 necessary. This feature was broken for very long pattern lines, leading to
2020 a string of junk being passed to pcre_compile() if the pattern was longer
2021 than about 50K.
2023 17. I have done a major re-factoring of the way pcre_compile() computes the
2024 amount of memory needed for a compiled pattern. Previously, there was code
2025 that made a preliminary scan of the pattern in order to do this. That was
2026 OK when PCRE was new, but as the facilities have expanded, it has become
2027 harder and harder to keep it in step with the real compile phase, and there
2028 have been a number of bugs (see for example, 4 above). I have now found a
2029 cunning way of running the real compile function in a "fake" mode that
2030 enables it to compute how much memory it would need, while actually only
2031 ever using a few hundred bytes of working memory and without too many
2032 tests of the mode. This should make future maintenance and development
2033 easier. A side effect of this work is that the limit of 200 on the nesting
2034 depth of parentheses has been removed (though this was never a serious
2035 limitation, I suspect). However, there is a downside: pcre_compile() now
2036 runs more slowly than before (30% or more, depending on the pattern). I
2037 hope this isn't a big issue. There is no effect on runtime performance.
2039 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2040 newline (only possible for the last line of a file) and it was a
2041 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2043 19. Added additional timing features to pcretest. (1) The -tm option now times
2044 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2045 separate command line item, by a number that specifies the number of
2046 repeats to use when timing. The default is 50000; this gives better
2047 precision, but takes uncomfortably long for very large patterns.
2049 20. Extended pcre_study() to be more clever in cases where a branch of a
2050 subpattern has no definite first character. For example, (a*|b*)[cd] would
2051 previously give no result from pcre_study(). Now it recognizes that the
2052 first character must be a, b, c, or d.
2054 21. There was an incorrect error "recursive call could loop indefinitely" if
2055 a subpattern (or the entire pattern) that was being tested for matching an
2056 empty string contained only one non-empty item after a nested subpattern.
2057 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2058 incorrectly, because the \d was being skipped in the check.
2060 22. The pcretest program now has a new pattern option /B and a command line
2061 option -b, which is equivalent to adding /B to every pattern. This causes
2062 it to show the compiled bytecode, without the additional information that
2063 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2064 is the same as /B/I).
2066 23. A new optimization is now able automatically to treat some sequences such
2067 as a*b as a*+b. More specifically, if something simple (such as a character
2068 or a simple class like \d) has an unlimited quantifier, and is followed by
2069 something that cannot possibly match the quantified thing, the quantifier
2070 is automatically "possessified".
2072 24. A recursive reference to a subpattern whose number was greater than 39
2073 went wrong under certain circumstances in UTF-8 mode. This bug could also
2074 have affected the operation of pcre_study().
2076 25. Realized that a little bit of performance could be had by replacing
2077 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2079 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2081 27. Possessive quantifiers such as a++ were previously implemented by turning
2082 them into atomic groups such as ($>a+). Now they have their own opcodes,
2083 which improves performance. This includes the automatically created ones
2084 from 23 above.
2086 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2087 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2088 the first matched character to be a colon. This applied both to named and
2089 numbered groups.
2091 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2093 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2094 building PCRE on Windows easier, so I have included it in the distribution.
2096 31. There is now a check in pcretest against a ridiculously large number being
2097 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2098 loop, the loop is abandoned.
2100 32. Forward references to subpatterns in conditions such as (?(2)...) where
2101 subpattern 2 is defined later cause pcre_compile() to search forwards in
2102 the pattern for the relevant set of parentheses. This search went wrong
2103 when there were unescaped parentheses in a character class, parentheses
2104 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2106 33. "Subroutine" calls and backreferences were previously restricted to
2107 referencing subpatterns earlier in the regex. This restriction has now
2108 been removed.
2110 34. Added a number of extra features that are going to be in Perl 5.10. On the
2111 whole, these are just syntactic alternatives for features that PCRE had
2112 previously implemented using the Python syntax or my own invention. The
2113 other formats are all retained for compatibility.
2115 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2116 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2117 also .NET compatible.
2119 (b) A recursion or subroutine call to a named group can now be defined as
2120 (?&name) as well as (?P>name).
2122 (c) A backreference to a named group can now be defined as \k<name> or
2123 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2124 5.10, are also .NET compatible.
2126 (d) A conditional reference to a named group can now use the syntax
2127 (?(<name>) or (?('name') as well as (?(name).
2129 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2130 groups (named and numbered) that are never evaluated inline, but can be
2131 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2132 is always false. There may be only one alternative in such a group.
2134 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2135 as the simple (?(R). The condition is true only if the most recent
2136 recursion is that of the given number or name. It does not search out
2137 through the entire recursion stack.
2139 (g) The escape \gN or \g{N} has been added, where N is a positive or
2140 negative number, specifying an absolute or relative reference.
2142 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2143 some "unreachable code" warnings.
2145 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2146 things, this adds five new scripts.
2148 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2149 There were also incompatibilities regarding the handling of \Q..\E inside
2150 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2151 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2153 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2154 matches an empty string, and forcibly breaks the loop. There were bugs in
2155 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2156 against aaaa the result was just "a" rather than "aaaa", for example. Two
2157 separate and independent bugs (that affected different cases) have been
2158 fixed.
2160 39. Refactored the code to abolish the use of different opcodes for small
2161 capturing bracket numbers. This is a tidy that I avoided doing when I
2162 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2163 The new approach is not only tidier, it makes it possible to reduce the
2164 memory needed to fix the previous bug (38).
2166 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2167 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2168 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2169 mode.
2171 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2172 report.
2174 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2175 copy construction and assignment in the C++ wrapper.
2177 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2178 couple of bugs that could have given wrong results in the "--newline=crlf"
2179 case.
2181 44. Added a number of casts and did some reorganization of signed/unsigned int
2182 variables following suggestions from Dair Grant. Also renamed the variable
2183 "this" as "item" because it is a C++ keyword.
2185 45. Arranged for dftables to add
2187 #include "pcre_internal.h"
2189 to pcre_chartables.c because without it, gcc 4.x may remove the array
2190 definition from the final binary if PCRE is built into a static library and
2191 dead code stripping is activated.
2193 46. For an unanchored pattern, if a match attempt fails at the start of a
2194 newline sequence, and the newline setting is CRLF or ANY, and the next two
2195 characters are CRLF, advance by two characters instead of one.
2198 Version 6.7 04-Jul-06
2199 ---------------------
2201 1. In order to handle tests when input lines are enormously long, pcretest has
2202 been re-factored so that it automatically extends its buffers when
2203 necessary. The code is crude, but this _is_ just a test program. The
2204 default size has been increased from 32K to 50K.
2206 2. The code in pcre_study() was using the value of the re argument before
2207 testing it for NULL. (Of course, in any sensible call of the function, it
2208 won't be NULL.)
2210 3. The memmove() emulation function in pcre_internal.h, which is used on
2211 systems that lack both memmove() and bcopy() - that is, hardly ever -
2212 was missing a "static" storage class specifier.
2214 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2215 containing an extended class (one that cannot be represented by a bitmap
2216 because it contains high-valued characters or Unicode property items, e.g.
2217 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2218 pattern, but PCRE should not loop if you do not (it no longer does).
2219 [Detail: two cases were found: (a) a repeated subpattern containing an
2220 extended class; (b) a recursive reference to a subpattern that followed a
2221 previous extended class. It wasn't skipping over the extended class
2222 correctly when UTF-8 mode was not set.]
2224 5. A negated single-character class was not being recognized as fixed-length
2225 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2226 compile error "lookbehind assertion is not fixed length".
2228 6. The RunPerlTest auxiliary script was showing an unexpected difference
2229 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2230 write a Perl script that can interpret lines of an input file either as
2231 byte characters or as UTF-8, which is what "perltest" was being required to
2232 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2233 can't do is switch easily at run time between having the "use utf8;" pragma
2234 or not. In the end, I fudged it by using the RunPerlTest script to insert
2235 "use utf8;" explicitly for the UTF-8 tests.
2237 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2238 the end of the subject string, contrary to the documentation and to what
2239 Perl does. This was true of both matching functions. Now it matches only at
2240 the start of the subject and immediately after *internal* newlines.
2242 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2243 a pointer to an int instead of a pointer to an unsigned long int. This
2244 caused problems on 64-bit systems.
2246 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2247 instance of the 'standard' template library not being so standard".
2249 10. There was no check on the number of named subpatterns nor the maximum
2250 length of a subpattern name. The product of these values is used to compute
2251 the size of the memory block for a compiled pattern. By supplying a very
2252 long subpattern name and a large number of named subpatterns, the size
2253 computation could be caused to overflow. This is now prevented by limiting
2254 the length of names to 32 characters, and the number of named subpatterns
2255 to 10,000.
2257 11. Subpatterns that are repeated with specific counts have to be replicated in
2258 the compiled pattern. The size of memory for this was computed from the
2259 length of the subpattern and the repeat count. The latter is limited to
2260 65535, but there was no limit on the former, meaning that integer overflow
2261 could in principle occur. The compiled length of a repeated subpattern is
2262 now limited to 30,000 bytes in order to prevent this.
2264 12. Added the optional facility to have named substrings with the same name.
2266 13. Added the ability to use a named substring as a condition, using the
2267 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2268 are numbers (not recommended). Forward references are permitted.
2270 14. Added forward references in named backreferences (if you see what I mean).
2272 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2273 pattern could run off the end of the subject. For example, the pattern
2274 "(?s)(.{1,5})"8 did this with the subject "ab".
2276 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2277 PCRE_CASELESS was set when matching characters that were quantified with ?
2278 or *.
2280 17. A character class other than a single negated character that had a minimum
2281 but no maximum quantifier - for example [ab]{6,} - was not handled
2282 correctly by pce_dfa_exec(). It would match only one character.
2284 18. A valid (though odd) pattern that looked like a POSIX character
2285 class but used an invalid character after [ (for example [[,abc,]]) caused
2286 pcre_compile() to give the error "Failed: internal error: code overflow" or
2287 in some cases to crash with a glibc free() error. This could even happen if
2288 the pattern terminated after [[ but there just happened to be a sequence of
2289 letters, a binary zero, and a closing ] in the memory that followed.
2291 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2292 over the years. Originally (before any Unicode support), just the bottom 8
2293 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2294 output from "man perlunicode" includes this:
2296 The regular expression compiler produces polymorphic opcodes. That
2297 is, the pattern adapts to the data and automatically switches to
2298 the Unicode character scheme when presented with Unicode data--or
2299 instead uses a traditional byte scheme when presented with byte
2300 data.
2302 Sadly, a wide octal escape does not cause a switch, and in a string with
2303 no other multibyte characters, these octal escapes are treated as before.
2304 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2305 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2306 Unicode string.
2308 I have not perpetrated such confusion in PCRE. Up till now, it took just
2309 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2310 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2311 translate to the appropriate multibyte character.
2313 29. Applied some refactoring to reduce the number of warnings from Microsoft
2314 and Borland compilers. This has included removing the fudge introduced
2315 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2316 a warning about an unused variable.
2318 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2319 characters since release 4.0, because Perl (from release 5.004) does not.
2320 [Or at least, is documented not to: some releases seem to be in conflict
2321 with the documentation.] However, when a pattern was studied with
2322 pcre_study() and all its branches started with \s, PCRE still included VT
2323 as a possible starting character. Of course, this did no harm; it just
2324 caused an unnecessary match attempt.
2326 22. Removed a now-redundant internal flag bit that recorded the fact that case
2327 dependency changed within the pattern. This was once needed for "required
2328 byte" processing, but is no longer used. This recovers a now-scarce options
2329 bit. Also moved the least significant internal flag bit to the most-
2330 significant bit of the word, which was not previously used (hangover from
2331 the days when it was an int rather than a uint) to free up another bit for
2332 the future.
2334 23. Added support for CRLF line endings as well as CR and LF. As well as the
2335 default being selectable at build time, it can now be changed at runtime
2336 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2337 specify that it is scanning data with non-default line endings.
2339 24. Changed the definition of CXXLINK to make it agree with the definition of
2340 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2342 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2343 recursions. This makes a big different to stack usage for some patterns.
2345 26. If a subpattern containing a named recursion or subroutine reference such
2346 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2347 the space required for the compiled pattern went wrong and gave too small a
2348 value. Depending on the environment, this could lead to "Failed: internal
2349 error: code overflow at offset 49" or "glibc detected double free or
2350 corruption" errors.
2352 27. Applied patches from Google (a) to support the new newline modes and (b) to
2353 advance over multibyte UTF-8 characters in GlobalReplace.
2355 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2356 difference for some implementation of PCRE in some Windows version.
2358 29. Added some extra testing facilities to pcretest:
2360 \q<number> in a data line sets the "match limit" value
2361 \Q<number> in a data line sets the "match recursion limt" value
2362 -S <number> sets the stack size, where <number> is in megabytes
2364 The -S option isn't available for Windows.
2367 Version 6.6 06-Feb-06
2368 ---------------------
2370 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2371 in pcreposix.h. I have copied the definition from pcre.h.
2373 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2374 because pcre.h is no longer a built file.
2376 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2377 not normally included in the compiled code.
2380 Version 6.5 01-Feb-06
2381 ---------------------
2383 1. When using the partial match feature with pcre_dfa_exec(), it was not
2384 anchoring the second and subsequent partial matches at the new starting
2385 point. This could lead to incorrect results. For example, with the pattern
2386 /1234/, partially matching against "123" and then "a4" gave a match.
2388 2. Changes to pcregrep:
2390 (a) All non-match returns from pcre_exec() were being treated as failures
2391 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2392 error message is output. Some extra information is given for the
2394 probably the only errors that are likely to be caused by users (by
2395 specifying a regex that has nested indefinite repeats, for instance).
2396 If there are more than 20 of these errors, pcregrep is abandoned.
2398 (b) A binary zero was treated as data while matching, but terminated the
2399 output line if it was written out. This has been fixed: binary zeroes
2400 are now no different to any other data bytes.
2402 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2403 used to set a locale for matching. The --locale=xxxx long option has
2404 been added (no short equivalent) to specify a locale explicitly on the
2405 pcregrep command, overriding the environment variables.
2407 (d) When -B was used with -n, some line numbers in the output were one less
2408 than they should have been.
2410 (e) Added the -o (--only-matching) option.
2412 (f) If -A or -C was used with -c (count only), some lines of context were
2413 accidentally printed for the final match.
2415 (g) Added the -H (--with-filename) option.
2417 (h) The combination of options -rh failed to suppress file names for files
2418 that were found from directory arguments.
2420 (i) Added the -D (--devices) and -d (--directories) options.
2422 (j) Added the -F (--fixed-strings) option.
2424 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2426 (l) Added the --colo(u)r option.
2428 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2429 is not present by default.
2431 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2432 items such as (?R) or (?1), when the recursion could match a number of
2433 alternatives. If it matched one of the alternatives, but subsequently,
2434 outside the recursion, there was a failure, the code tried to back up into
2435 the recursion. However, because of the way PCRE is implemented, this is not
2436 possible, and the result was an incorrect result from the match.
2438 In order to prevent this happening, the specification of recursion has
2439 been changed so that all such subpatterns are automatically treated as
2440 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2442 4. I had overlooked the fact that, in some locales, there are characters for
2443 which isalpha() is true but neither isupper() nor islower() are true. In
2444 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2445 and ordfeminine) are like this. This affected the treatment of \w and \W
2446 when they appeared in character classes, but not when they appeared outside
2447 a character class. The bit map for "word" characters is now created
2448 separately from the results of isalnum() instead of just taking it from the
2449 upper, lower, and digit maps. (Plus the underscore character, of course.)
2451 5. The above bug also affected the handling of POSIX character classes such as
2452 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2453 permanent tables. Instead, the bit maps for such a class were previously
2454 created as the appropriate unions of the upper, lower, and digit bitmaps.
2455 Now they are created by subtraction from the [[:word:]] class, which has
2456 its own bitmap.
2458 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2459 It is created by subtracting the vertical space characters (\x09, \x0a,
2460 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2461 subtraction was done in the overall bitmap for a character class, meaning
2462 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2463 be recognized. This bug has been fixed.
2465 7. Patches from the folks at Google:
2467 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2468 real life, but is still worth protecting against".
2470 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2471 regular expressions".
2473 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2474 have it.
2476 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2477 "configure" and the latter not, in order to fix a problem somebody had
2478 with compiling the Arg class on HP-UX.
2480 (e) Improve the error-handling of the C++ wrapper a little bit.
2482 (f) New tests for checking recursion limiting.
2484 8. The pcre_memmove() function, which is used only if the environment does not
2485 have a standard memmove() function (and is therefore rarely compiled),
2486 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2487 returning a result (though PCRE never actually uses the result).
2489 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2490 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2491 returned instead of calling malloc() with an overflowing number that would
2492 most likely cause subsequent chaos.
2494 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2496 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2497 with this option is matched, the nmatch and pmatch options of regexec() are
2498 ignored.
2500 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2501 provided in case anyone wants to the the POSIX interface with UTF-8
2502 strings.
2504 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2505 C++ linking (needed for some HP-UX environments).
2507 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2508 (unused parameter) and in the pcre_printint() function (omitted "default"
2509 switch label when the default is to do nothing).
2511 15. Added some code to make it possible, when PCRE is compiled as a C++
2512 library, to replace subject pointers for pcre_exec() with a smart pointer
2513 class, thus making it possible to process discontinuous strings.
2515 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2516 much the same function. They were added by different people who were trying
2517 to make PCRE easy to compile on non-Unix systems. It has been suggested
2518 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2519 for compiling on Windows systems. I have therefore replaced it with
2520 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2521 defaults to "extern" for C or "extern C" for C++, which works fine on
2522 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2523 SCOPE with something explicit in config.h. In addition:
2525 (a) pcreposix.h still had just "extern" instead of either of these macros;
2526 I have replaced it with PCRE_DATA_SCOPE.
2528 (b) Functions such as _pcre_xclass(), which are internal to the library,
2529 but external in the C sense, all had PCRE_EXPORT in their definitions.
2530 This is apparently wrong for the Windows case, so I have removed it.
2531 (It makes no difference on Unix-like systems.)
2533 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2534 of recursive calls to match(). This is different to MATCH_LIMIT because
2535 that limits the total number of calls to match(), not all of which increase
2536 the depth of recursion. Limiting the recursion depth limits the amount of
2537 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2538 when PCRE is compiled, and changed at run time. A patch from Google adds
2539 this functionality to the C++ interface.
2541 18. Changes to the handling of Unicode character properties:
2543 (a) Updated the table to Unicode 4.1.0.
2545 (b) Recognize characters that are not in the table as "Cn" (undefined).
2547 (c) I revised the way the table is implemented to a much improved format
2548 which includes recognition of ranges. It now supports the ranges that
2549 are defined in UnicodeData.txt, and it also amalgamates other
2550 characters into ranges. This has reduced the number of entries in the
2551 table from around 16,000 to around 3,000, thus reducing its size
2552 considerably. I realized I did not need to use a tree structure after
2553 all - a binary chop search is just as efficient. Having reduced the
2554 number of entries, I extended their size from 6 bytes to 8 bytes to
2555 allow for more data.
2557 (d) Added support for Unicode script names via properties such as \p{Han}.
2559 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2560 matching that character.
2562 20. When matching a repeated Unicode property with a minimum greater than zero,
2563 (for example \pL{2,}), PCRE could look past the end of the subject if it
2564 reached it while seeking the minimum number of characters. This could
2565 happen only if some of the characters were more than one byte long, because
2566 there is a check for at least the minimum number of bytes.
2568 21. Refactored the implementation of \p and \P so as to be more general, to
2569 allow for more different types of property in future. This has changed the
2570 compiled form incompatibly. Anybody with saved compiled patterns that use
2571 \p or \P will have to recompile them.
2573 22. Added "Any" and "L&" to the supported property types.
2575 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2576 but give a compile time error if the value is greater than 0xff.
2578 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2579 accidentally not being installed or uninstalled.
2581 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2582 made were to insert the current release number. This seemed silly, because
2583 it made things harder for people building PCRE on systems that don't run
2584 "configure". I have turned pcre.h into a distributed file, no longer built
2585 by "configure", with the version identification directly included. There is
2586 no longer a pcre.h.in file.
2588 However, this change necessitated a change to the pcre-config script as
2589 well. It is built from pcre-config.in, and one of the substitutions was the
2590 release number. I have updated configure.ac so that ./configure now finds
2591 the release number by grepping pcre.h.
2593 26. Added the ability to run the tests under valgrind.
2596 Version 6.4 05-Sep-05
2597 ---------------------
2599 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2600 "--" to be printed when multiple files were scanned, even when none of the
2601 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2602 consider it to be a bug, and have restored the previous behaviour.
2604 2. A couple of code tidies to get rid of compiler warnings.
2606 3. The pcretest program used to cheat by referring to symbols in the library
2607 whose names begin with _pcre_. These are internal symbols that are not
2608 really supposed to be visible externally, and in some environments it is
2609 possible to suppress them. The cheating is now confined to including
2610 certain files from the library's source, which is a bit cleaner.
2612 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2613 file's purpose clearer.
2615 5. Reorganized pcre_ucp_findchar().
2618 Version 6.3 15-Aug-05
2619 ---------------------
2621 1. The file libpcre.pc.in did not have general read permission in the tarball.
2623 2. There were some problems when building without C++ support:
2625 (a) If C++ support was not built, "make install" and "make test" still
2626 tried to test it.
2628 (b) There were problems when the value of CXX was explicitly set. Some
2629 changes have been made to try to fix these, and ...
2631 (c) --disable-cpp can now be used to explicitly disable C++ support.
2633 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2634 backslash in a target when C++ was disabled. This confuses some
2635 versions of "make", apparently. Using an intermediate variable solves
2636 this. (Same for CPP_LOBJ.)
2638 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2639 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2640 necessary on certain architectures.
2642 4. Added a setting of -export-symbols-regex to the link command to remove
2643 those symbols that are exported in the C sense, but actually are local
2644 within the library, and not documented. Their names all begin with
2645 "_pcre_". This is not a perfect job, because (a) we have to except some
2646 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2647 available (and never for static libraries). I have made a note to try to
2648 find a way round (a) in the future.
2651 Version 6.2 01-Aug-05
2652 ---------------------
2654 1. There was no test for integer overflow of quantifier values. A construction
2655 such as {1111111111111111} would give undefined results. What is worse, if
2656 a minimum quantifier for a parenthesized subpattern overflowed and became
2657 negative, the calculation of the memory size went wrong. This could have
2658 led to memory overwriting.
2660 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2662 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2663 operating environments where this matters.
2665 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2666 PCRE options from within the C++ wrapper.
2668 5. Named capturing subpatterns were not being correctly counted when a pattern
2669 was compiled. This caused two problems: (a) If there were more than 100
2670 such subpatterns, the calculation of the memory needed for the whole
2671 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2672 back references of the form \12, where the number was greater than 9, were
2673 not recognized as back references, even though there were sufficient
2674 previous subpatterns.
2676 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2677 versions of gcc, e.g. 2.95.4.
2680 Version 6.1 21-Jun-05
2681 ---------------------
2683 1. There was one reference to the variable "posix" in pcretest.c that was not
2684 surrounded by "#if !defined NOPOSIX".
2686 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2687 the cross-check on the old pcre_info() function, for the benefit of the
2688 cut-down version of PCRE that is currently imported into Exim.
2690 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2691 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2692 patterns that start (?i) but I don't think that matters. The use of (?i) is
2693 just an example; this all applies to the other options as well.
2695 4. Since libtool seems to echo the compile commands it is issuing, the output
2696 from "make" can be reduced a bit by putting "@" in front of each libtool
2697 compile command.
2699 5. Patch from the folks at Google for configure.in to be a bit more thorough
2700 in checking for a suitable C++ installation before trying to compile the
2701 C++ stuff. This should fix a reported problem when a compiler was present,
2702 but no suitable headers.
2704 6. The man pages all had just "PCRE" as their title. I have changed them to
2705 be the relevant file name. I have also arranged that these names are
2706 retained in the file doc/pcre.txt, which is a concatenation in text format
2707 of all the man pages except the little individual ones for each function.
2709 7. The NON-UNIX-USE file had not been updated for the different set of source
2710 files that come with release 6. I also added a few comments about the C++
2711 wrapper.
2714 Version 6.0 07-Jun-05
2715 ---------------------
2717 1. Some minor internal re-organization to help with my DFA experiments.
2719 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2720 didn't matter for the library itself when fully configured, but did matter
2721 when compiling without UCP support, or within Exim, where the ucp files are
2722 not imported.
2724 3. Refactoring of the library code to split up the various functions into
2725 different source modules. The addition of the new DFA matching code (see
2726 below) to a single monolithic source would have made it really too
2727 unwieldy, quite apart from causing all the code to be include in a
2728 statically linked application, when only some functions are used. This is
2729 relevant even without the DFA addition now that patterns can be compiled in
2730 one application and matched in another.
2732 The downside of splitting up is that there have to be some external
2733 functions and data tables that are used internally in different modules of
2734 the library but which are not part of the API. These have all had their
2735 names changed to start with "_pcre_" so that they are unlikely to clash
2736 with other external names.
2738 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2739 a different (DFA) algorithm. Although it is slower than the original
2740 function, it does have some advantages for certain types of matching
2741 problem.
2743 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2744 including restarting after a partial match.
2746 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2747 defined when compiling for Windows was sent to me. I have put it into the
2748 code, though I have no means of testing or verifying it.
2750 7. Added the pcre_refcount() auxiliary function.
2752 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2753 match before or at the first newline in the subject string. In pcretest,
2754 the /f option on a pattern can be used to set this.
2756 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2757 would behave wrongly. This has been present in PCRE since release 4.0.
2759 10. A number of changes to the pcregrep command:
2761 (a) Refactored how -x works; insert ^(...)$ instead of setting
2762 PCRE_ANCHORED and checking the length, in preparation for adding
2763 something similar for -w.
2765 (b) Added the -w (match as a word) option.
2767 (c) Refactored the way lines are read and buffered so as to have more
2768 than one at a time available.
2770 (d) Implemented a pcregrep test script.
2772 (e) Added the -M (multiline match) option. This allows patterns to match
2773 over several lines of the subject. The buffering ensures that at least
2774 8K, or the rest of the document (whichever is the shorter) is available
2775 for matching (and similarly the previous 8K for lookbehind assertions).
2777 (f) Changed the --help output so that it now says
2779 -w, --word-regex(p)
2781 instead of two lines, one with "regex" and the other with "regexp"
2782 because that confused at least one person since the short forms are the
2783 same. (This required a bit of code, as the output is generated
2784 automatically from a table. It wasn't just a text change.)
2786 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2787 option but starts with a hyphen. Could be a pattern or a path name
2788 starting with a hyphen, for instance.
2790 (h) "-" can be given as a file name to represent stdin.
2792 (i) When file names are being printed, "(standard input)" is used for
2793 the standard input, for compatibility with GNU grep. Previously
2794 "<stdin>" was used.
2796 (j) The option --label=xxx can be used to supply a name to be used for
2797 stdin when file names are being printed. There is no short form.
2799 (k) Re-factored the options decoding logic because we are going to add
2800 two more options that take data. Such options can now be given in four
2801 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2803 (l) Added the -A, -B, and -C options for requesting that lines of context
2804 around matches be printed.
2806 (m) Added the -L option to print the names of files that do not contain
2807 any matching lines, that is, the complement of -l.
2809 (n) The return code is 2 if any file cannot be opened, but pcregrep does
2810 continue to scan other files.
2812 (o) The -s option was incorrectly implemented. For compatibility with other
2813 greps, it now suppresses the error message for a non-existent or non-
2814 accessible file (but not the return code). There is a new option called
2815 -q that suppresses the output of matching lines, which was what -s was
2816 previously doing.
2818 (p) Added --include and --exclude options to specify files for inclusion
2819 and exclusion when recursing.
2821 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
2822 Hopefully, it now does.
2824 12. Missing cast in pcre_study().
2826 13. Added an "uninstall" target to the makefile.
2828 14. Replaced "extern" in the function prototypes in Makefile.in with
2829 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
2830 world, but is set differently for Windows.
2832 15. Added a second compiling function called pcre_compile2(). The only
2833 difference is that it has an extra argument, which is a pointer to an
2834 integer error code. When there is a compile-time failure, this is set
2835 non-zero, in addition to the error test pointer being set to point to an
2836 error message. The new argument may be NULL if no error number is required
2837 (but then you may as well call pcre_compile(), which is now just a
2838 wrapper). This facility is provided because some applications need a
2839 numeric error indication, but it has also enabled me to tidy up the way
2840 compile-time errors are handled in the POSIX wrapper.
2842 16. Added VPATH=.libs to the makefile; this should help when building with one
2843 prefix path and installing with another. (Or so I'm told by someone who
2844 knows more about this stuff than I do.)
2846 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
2847 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
2848 match everything, including newlines. This is not POSIX-compatible, but
2849 somebody wanted the feature. From pcretest it can be activated by using
2850 both the P and the s flags.
2852 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
2854 19. libpcre.pc was being incorrectly installed as executable.
2856 20. A couple of places in pcretest check for end-of-line by looking for '\n';
2857 it now also looks for '\r' so that it will work unmodified on Windows.
2859 21. Added Google's contributed C++ wrapper to the distribution.
2861 22. Added some untidy missing memory free() calls in pcretest, to keep
2862 Electric Fence happy when testing.
2866 Version 5.0 13-Sep-04
2867 ---------------------
2869 1. Internal change: literal characters are no longer packed up into items
2870 containing multiple characters in a single byte-string. Each character
2871 is now matched using a separate opcode. However, there may be more than one
2872 byte in the character in UTF-8 mode.
2874 2. The pcre_callout_block structure has two new fields: pattern_position and
2875 next_item_length. These contain the offset in the pattern to the next match
2876 item, and its length, respectively.
2878 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
2879 insertion of callouts before each pattern item. Added the /C option to
2880 pcretest to make use of this.
2882 4. On the advice of a Windows user, the lines
2884 #if defined(_WIN32) || defined(WIN32)
2885 _setmode( _fileno( stdout ), 0x8000 );
2886 #endif /* defined(_WIN32) || defined(WIN32) */
2888 have been added to the source of pcretest. This apparently does useful
2889 magic in relation to line terminators.
2891 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
2892 for the benefit of those environments where the "b" makes a difference.
2894 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
2895 to know about it. I have put a hack into configure.in that adds in code
2896 to set GCC=yes if CC=icc. This seems to end up at a point in the
2897 generated configure script that is early enough to affect the setting of
2898 compiler options, which is what is needed, but I have no means of testing
2899 whether it really works. (The user who reported this had patched the
2900 generated configure script, which of course I cannot do.)
2902 LATER: After change 22 below (new libtool files), the configure script
2903 seems to know about icc (and also ecc). Therefore, I have commented out
2904 this hack in configure.in.
2906 7. Added support for pkg-config (2 patches were sent in).
2908 8. Negated POSIX character classes that used a combination of internal tables
2909 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
2910 [[:^ascii]]. Typically, they would match almost any characters. The other
2911 POSIX classes were not broken in this way.
2913 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
2914 to find the match, as PCRE was deluded into thinking that the match had to
2915 start at the start point or following a newline. The same bug applied to
2916 patterns with negative forward assertions or any backward assertions
2917 preceding ".*" at the start, unless the pattern required a fixed first
2918 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
2920 10. In UTF-8 mode, when moving forwards in the subject after a failed match
2921 starting at the last subject character, bytes beyond the end of the subject
2922 string were read.
2924 11. Renamed the variable "class" as "classbits" to make life easier for C++
2925 users. (Previously there was a macro definition, but it apparently wasn't
2926 enough.)
2928 12. Added the new field "tables" to the extra data so that tables can be passed
2929 in at exec time, or the internal tables can be re-selected. This allows
2930 a compiled regex to be saved and re-used at a later time by a different
2931 program that might have everything at different addresses.
2933 13. Modified the pcre-config script so that, when run on Solaris, it shows a
2934 -R library as well as a -L library.
2936 14. The debugging options of pcretest (-d on the command line or D on a
2937 pattern) showed incorrect output for anything following an extended class
2938 that contained multibyte characters and which was followed by a quantifier.
2940 15. Added optional support for general category Unicode character properties
2941 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2942 support. It adds about 90K to the size of the library. The meanings of the
2943 inbuilt class escapes such as \d and \s have NOT been changed.
2945 16. Updated pcredemo.c to include calls to free() to release the memory for the
2946 compiled pattern.
2948 17. The generated file chartables.c was being created in the source directory
2949 instead of in the building directory. This caused the build to fail if the
2950 source directory was different from the building directory, and was
2951 read-only.
2953 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2954 file. No doubt somebody will tell me if they don't make sense... Also added
2955 Dan Mooney's comments about building on OpenVMS.
2957 19. Added support for partial matching via the PCRE_PARTIAL option for
2958 pcre_exec() and the \P data escape in pcretest.
2960 20. Extended pcretest with 3 new pattern features:
2962 (i) A pattern option of the form ">rest-of-line" causes pcretest to
2963 write the compiled pattern to the file whose name is "rest-of-line".
2964 This is a straight binary dump of the data, with the saved pointer to
2965 the character tables forced to be NULL. The study data, if any, is
2966 written too. After writing, pcretest reads a new pattern.
2968 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2969 compiled pattern from the given file. There must not be any
2970 occurrences of "<" in the file name (pretty unlikely); if there are,
2971 pcretest will instead treat the initial "<" as a pattern delimiter.
2972 After reading in the pattern, pcretest goes on to read data lines as
2973 usual.
2975 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2976 and 16-bit fields in a compiled pattern, to simulate a pattern that
2977 was compiled on a host of opposite endianness.
2979 21. The pcre-exec() function can now cope with patterns that were compiled on
2980 hosts of opposite endianness, with this restriction:
2982 As for any compiled expression that is saved and used later, the tables
2983 pointer field cannot be preserved; the extra_data field in the arguments
2984 to pcre_exec() should be used to pass in a tables address if a value
2985 other than the default internal tables were used at compile time.
2987 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2988 now diagnosed as an error. Previously, most of the time, a negative number
2989 would have been treated as zero, but if in addition "ovector" was passed as
2990 NULL, a crash could occur.
2992 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2993 new versions from the libtool 1.5 distribution (the last one is a copy of
2994 a file called libtool.m4). This seems to have fixed the need to patch
2995 "configure" to support Darwin 1.3 (which I used to do). However, I still
2996 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2997 workstation).
2999 24. Changed the PCRE licence to be the more standard "BSD" licence.
3002 Version 4.5 01-Dec-03
3003 ---------------------
3005 1. There has been some re-arrangement of the code for the match() function so
3006 that it can be compiled in a version that does not call itself recursively.
3007 Instead, it keeps those local variables that need separate instances for
3008 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3009 needs to "recurse". Keeping track of where control must go is done by means
3010 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3011 hide most of the details from the main code, and operates only if
3012 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3013 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3014 operating.
3016 To make it easier for callers to provide specially tailored get/free
3017 functions for this usage, two new functions, pcre_stack_malloc, and
3018 pcre_stack_free, are used. They are always called in strict stacking order,
3019 and the size of block requested is always the same.
3021 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3022 PCRE has been compiled to use the stack or the heap for recursion. The
3023 -C option of pcretest uses this to show which version is compiled.
3025 A new data escape \S, is added to pcretest; it causes the amounts of store
3026 obtained and freed by both kinds of malloc/free at match time to be added
3027 to the output.
3029 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3030 what's available on my current Linux desktop machine.
3032 3. When matching a UTF-8 string, the test for a valid string at the start has
3033 been extended. If start_offset is not zero, PCRE now checks that it points
3034 to a byte that is the start of a UTF-8 character. If not, it returns
3035 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3036 this is necessary because there may be backward assertions in the pattern.
3037 When matching the same subject several times, it may save resources to use
3038 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3040 4. The code for checking the validity of UTF-8 strings has been tightened so
3041 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3042 containing "overlong sequences".
3044 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3045 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3046 should have been "&", but it just so happened that all the cases this let
3047 through by mistake were picked up later in the function.
3049 6. I had used a variable called "isblank" - this is a C99 function, causing
3050 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3052 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3053 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3054 so the version is shown; (c) stop "make test" echoing "./RunTest".
3056 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3058 9. The prototype for memmove() for systems that don't have it was using
3059 size_t, but the inclusion of the header that defines size_t was later. I've
3060 moved the #includes for the C headers earlier to avoid this.
3062 10. Added some adjustments to the code to make it easier to compiler on certain
3063 special systems:
3065 (a) Some "const" qualifiers were missing.
3066 (b) Added the macro EXPORT before all exported functions; by default this
3067 is defined to be empty.
3068 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3069 that it reads its output file name as an argument instead of writing
3070 to the standard output and assuming this can be redirected.
3072 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3073 class containing characters with values greater than 255, PCRE compilation
3074 went into a loop.
3076 12. A recursive reference to a subpattern that was within another subpattern
3077 that had a minimum quantifier of zero caused PCRE to crash. For example,
3078 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3079 recursion. If the recursively-called subpattern itself had a zero repeat,
3080 that was OK.
3082 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3083 buffer into which it was copied (for escape processing) was still set at
3084 1024, so long lines caused crashes.
3086 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3087 "internal error: code overflow...". This applied to any character class
3088 that was followed by a possessive quantifier.
3090 15. Modified the Makefile to add libpcre.la as a prerequisite for
3091 libpcreposix.la because I was told this is needed for a parallel build to
3092 work.
3094 16. If a pattern that contained .* following optional items at the start was
3095 studied, the wrong optimizing data was generated, leading to matching
3096 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3097 matching string must start with a or b or c. The correct conclusion for
3098 this pattern is that a match can start with any character.
3101 Version 4.4 13-Aug-03
3102 ---------------------
3104 1. In UTF-8 mode, a character class containing characters with values between
3105 127 and 255 was not handled correctly if the compiled pattern was studied.
3106 In fixing this, I have also improved the studying algorithm for such
3107 classes (slightly).
3109 2. Three internal functions had redundant arguments passed to them. Removal
3110 might give a very teeny performance improvement.
3112 3. Documentation bug: the value of the capture_top field in a callout is *one
3113 more than* the number of the hightest numbered captured substring.
3115 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3116 in incorrectly linking with a previously installed version. They now link
3117 explicitly with libpcre.la.
3119 5. configure.in no longer needs to recognize Cygwin specially.
3121 6. A problem in pcre.in for Windows platforms is fixed.
3123 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3124 pcretest, it used to include the size of the study block as part of its
3125 output. Unfortunately, the structure contains a field that has a different
3126 size on different hardware architectures. This meant that the tests that
3127 showed this size failed. As the block is currently always of a fixed size,
3128 this information isn't actually particularly useful in pcretest output, so
3129 I have just removed it.
3131 8. Three pre-processor statements accidentally did not start in column 1.
3132 Sadly, there are *still* compilers around that complain, even though
3133 standard C has not required this for well over a decade. Sigh.
3135 9. In pcretest, the code for checking callouts passed small integers in the
3136 callout_data field, which is a void * field. However, some picky compilers
3137 complained about the casts involved for this on 64-bit systems. Now
3138 pcretest passes the address of the small integer instead, which should get
3139 rid of the warnings.
3141 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3142 both compile and run time, and gives an error if an invalid UTF-8 sequence
3143 is found. There is a option for disabling this check in cases where the
3144 string is known to be correct and/or the maximum performance is wanted.
3146 11. In response to a bug report, I changed one line in Makefile.in from
3148 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3149 to
3150 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3152 to look similar to other lines, but I have no way of telling whether this
3153 is the right thing to do, as I do not use Windows. No doubt I'll get told
3154 if it's wrong...
3157 Version 4.3 21-May-03
3158 ---------------------
3160 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3161 Makefile.
3163 2. Some refactoring to improve the quality of the code:
3165 (i) The utf8_table... variables are now declared "const".
3167 (ii) The code for \cx, which used the "case flipping" table to upper case
3168 lower case letters, now just substracts 32. This is ASCII-specific,
3169 but the whole concept of \cx is ASCII-specific, so it seems
3170 reasonable.
3172 (iii) PCRE was using its character types table to recognize decimal and
3173 hexadecimal digits in the pattern. This is silly, because it handles
3174 only 0-9, a-f, and A-F, but the character types table is locale-
3175 specific, which means strange things might happen. A private
3176 table is now used for this - though it costs 256 bytes, a table is
3177 much faster than multiple explicit tests. Of course, the standard
3178 character types table is still used for matching digits in subject
3179 strings against \d.
3181 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3182 ending in _t are). So I've renamed it as ESC_tee.
3184 3. The first argument for regexec() in the POSIX wrapper should have been
3185 defined as "const".
3187 4. Changed pcretest to use malloc() for its buffers so that they can be
3188 Electric Fenced for debugging.
3190 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3191 to read one or more bytes before the start of the subject string. Often this
3192 had no effect on PCRE's behaviour, but in some circumstances it could
3193 provoke a segmentation fault.
3195 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3196 to try to read one or more bytes before the start of the subject string.
3198 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3199 UTF-8 support could misbehave in various ways if the subject string
3200 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3201 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3202 back over UTF-8 characters.)
3205 Version 4.2 14-Apr-03
3206 ---------------------
3208 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3210 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3211 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3212 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3213 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3214 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3216 Note: automatic setting of the BUILD variables is not yet working
3217 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3218 compile-time but not at link-time
3219 [LINK]: use for linking executables only
3220 make different versions for Windows and non-Windows
3221 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3222 libraries
3223 [LINK_FOR_BUILD]: new variable
3224 [OBJEXT]: use throughout
3225 [EXEEXT]: use throughout
3226 <winshared>: new target
3227 <wininstall>: new target
3228 <dftables.o>: use native compiler
3229 <dftables>: use native linker
3230 <install>: handle Windows platform correctly
3231 <clean>: ditto
3232 <check>: ditto
3233 copy DLL to top builddir before testing
3235 As part of these changes, -no-undefined was removed again. This was reported
3236 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3237 in any case.
3239 3. Some tidies to get rid of compiler warnings:
3241 . In the match_data structure, match_limit was an unsigned long int, whereas
3242 match_call_count was an int. I've made them both unsigned long ints.
3244 . In pcretest the fact that a const uschar * doesn't automatically cast to
3245 a void * provoked a warning.
3247 . Turning on some more compiler warnings threw up some "shadow" variables
3248 and a few more missing casts.
3250 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3251 option, a class that contained a single character with a value between 128
3252 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3254 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3255 option, a class that contained several characters, but with at least one
3256 whose value was between 128 and 255 caused PCRE to crash.
3259 Version 4.1 12-Mar-03
3260 ---------------------
3262 1. Compiling with gcc -pedantic found a couple of places where casts were
3263 needed, and a string in dftables.c that was longer than standard compilers are
3264 required to support.
3266 2. Compiling with Sun's compiler found a few more places where the code could
3267 be tidied up in order to avoid warnings.
3269 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3270 first of these names is deprecated in the latest Autoconf in favour of the name
3271 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3272 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3273 analogy I have changed it to CFLAGS_FOR_BUILD.
3275 4. Added -no-undefined to the linking command in the Makefile, because this is
3276 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3277 linking step for the pcreposix library.
3279 5. PCRE was failing to diagnose the case of two named groups with the same
3280 name.
3282 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3283 literal character that is needed in the subject for a match, and scans along to
3284 ensure that it is present before embarking on the full matching process. This
3285 saves time in cases of nested unlimited repeats that are never going to match.
3286 Problem: the scan can take a lot of time if the subject is very long (e.g.
3287 megabytes), thus penalizing straightforward matches. It is now done only if the
3288 amount of subject to be scanned is less than 1000 bytes.
3290 7. A lesser problem with the same optimization is that it was recording the
3291 first character of an anchored pattern as "needed", thus provoking a search
3292 right along the subject, even when the first match of the pattern was going to
3293 fail. The "needed" character is now not set for anchored patterns, unless it
3294 follows something in the pattern that is of non-fixed length. Thus, it still
3295 fulfils its original purpose of finding quick non-matches in cases of nested
3296 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3299 Version 4.0 17-Feb-03
3300 ---------------------
3302 1. If a comment in an extended regex that started immediately after a meta-item
3303 extended to the end of string, PCRE compiled incorrect data. This could lead to
3304 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3306 2. Moved to autoconf 2.53 and libtool 1.4.2.
3308 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3309 the special perltest8 script is no longer needed - all the tests can be run
3310 from a single perltest script.
3312 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3313 by \s. It has now been removed in PCRE. This means it isn't recognized as
3314 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3315 class [:space:] *does* include VT, thereby creating a mess.
3317 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3318 space and tab.
3320 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3321 its new features into the main test script, reducing the number of scripts.
3323 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3324 were backward compatible, and made the (?i) apply to the whole pattern, as if
3325 /i were given. Now it behaves more logically, and applies the option setting
3326 only to what follows. PCRE has been changed to follow suit. However, if it
3327 finds options settings right at the start of the pattern, it extracts them into
3328 the global options, as before. Thus, they show up in the info data.
3330 8. Added support for the \Q...\E escape sequence. Characters in between are
3331 treated as literals. This is slightly different from Perl in that $ and @ are
3332 also handled as literals inside the quotes. In Perl, they will cause variable
3333 interpolation. Note the following examples:
3335 Pattern PCRE matches Perl matches
3337 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3338 \Qabc\$xyz\E abc\$xyz abc\$xyz
3339 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3341 For compatibility with Perl, \Q...\E sequences are recognized inside character
3342 classes as well as outside them.
3344 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3345 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3346 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3347 signed/unsigned warnings.
3349 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3350 option for pcretest, so I've replaced it by a simple function that does just
3351 that job.
3353 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3354 "pcregrep -".
3356 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3357 Java package. This provides some syntactic sugar for simple cases of what my
3358 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3359 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3360 item, you can use this simplified notation. Note that only makes sense with
3361 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3362 greediness, whatever the setting of the PCRE_UNGREEDY option.
3364 13. A change of greediness default within a pattern was not taking effect at
3365 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3366 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3367 was abstracted outside.
3369 14. PCRE now supports the \G assertion. It is true when the current matching
3370 position is at the start point of the match. This differs from \A when the
3371 starting offset is non-zero. Used with the /g option of pcretest (or similar
3372 code), it works in the same way as it does for Perl's /g option. If all
3373 alternatives of a regex begin with \G, the expression is anchored to the start
3374 match position, and the "anchored" flag is set in the compiled expression.
3376 15. Some bugs concerning the handling of certain option changes within patterns
3377 have been fixed. These applied to options other than (?ims). For example,
3378 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3379 been the other way round. Some of this was related to change 7 above.
3381 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3382 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3383 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3384 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3386 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3387 mode. Unlike ".", it always matches newline, whatever the setting of
3388 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3389 assertions. Perl allows it, but it doesn't (in general) work because it can't
3390 calculate the length of the lookbehind. At least, that's the case for Perl
3391 5.8.0 - I've been told they are going to document that it doesn't work in
3392 future.
3394 18. Added an error diagnosis for escapes that PCRE does not support: these are
3395 \L, \l, \N, \P, \p, \U, \u, and \X.
3397 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3398 reading past the end of the pattern in cases such as /[abcd/.
3400 20. PCRE was getting more memory than necessary for patterns with classes that
3401 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3403 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3404 compiling PCRE for use with Virtual Pascal.
3406 22. Small fix to the Makefile to make it work properly if the build is done
3407 outside the source tree.
3409 23. Added a new extension: a condition to go with recursion. If a conditional
3410 subpattern starts with (?(R) the "true" branch is used if recursion has
3411 happened, whereas the "false" branch is used only at the top level.
3413 24. When there was a very long string of literal characters (over 255 bytes
3414 without UTF support, over 250 bytes with UTF support), the computation of how
3415 much memory was required could be incorrect, leading to segfaults or other
3416 strange effects.
3418 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3419 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3420 there was a subsequent back reference to those brackets. This meant that, for
3421 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3422 possible to check for precisely this case. All we can do is abandon the
3423 optimization if .* occurs inside capturing brackets when there are any back
3424 references whatsoever. (See below for a better fix that came later.)
3426 26. The handling of the optimization for finding the first character of a
3427 non-anchored pattern, and for finding a character that is required later in the
3428 match were failing in some cases. This didn't break the matching; it just
3429 failed to optimize when it could. The way this is done has been re-implemented.
3431 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3433 28. Added a new feature that provides some of the functionality that Perl
3434 provides with (?{...}). The facility is termed a "callout". The way it is done
3435 in PCRE is for the caller to provide an optional function, by setting
3436 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3437 global variable. By default it is unset, which disables all calling out. To get
3438 the function called, the regex must include (?C) at appropriate points. This
3439 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3440 This provides a means of identifying different callout points. When PCRE
3441 reaches such a point in the regex, if pcre_callout has been set, the external
3442 function is called. It is provided with data in a structure called
3443 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3444 matching continues; if it returns a non-zero value, the match at the current
3445 point fails. However, backtracking will occur if possible. [This was changed
3446 later and other features added - see item 49 below.]
3448 29. pcretest is upgraded to test the callout functionality. It provides a
3449 callout function that displays information. By default, it shows the start of
3450 the match and the current position in the text. There are some new data escapes
3451 to vary what happens:
3453 \C+ in addition, show current contents of captured substrings
3454 \C- do not supply a callout function
3455 \C!n return 1 when callout number n is reached
3456 \C!n!m return 1 when callout number n is reached for the mth time
3458 30. If pcregrep was called with the -l option and just a single file name, it
3459 output "<stdin>" if a match was found, instead of the file name.
3461 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3462 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3463 pcre_exec(). This saves a malloc/free per call. The default value of
3464 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3465 when configuring.
3467 32. The default maximum size of a compiled pattern is 64K. There have been a
3468 few cases of people hitting this limit. The code now uses macros to handle the
3469 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3470 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3471 configuring. Tests 2 and 5 work only with 2-byte links because they output
3472 debugging information about compiled patterns.
3474 33. Internal code re-arrangements:
3476 (a) Moved the debugging function for printing out a compiled regex into
3477 its own source file (printint.c) and used #include to pull it into
3478 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3479 separate copies.
3481 (b) Defined the list of op-code names for debugging as a macro in
3482 internal.h so that it is next to the definition of the opcodes.
3484 (c) Defined a table of op-code lengths for simpler skipping along compiled
3485 code. This is again a macro in internal.h so that it is next to the
3486 definition of the opcodes.
3488 34. Added support for recursive calls to individual subpatterns, along the
3489 lines of Robin Houston's patch (but implemented somewhat differently).
3491 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3492 allow it to read and process whole directories in Win32. This code was
3493 contributed by Lionel Fourquaux; it has not been tested by me.
3495 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3496 used to name a group. Names consist of alphanumerics and underscores, and must
3497 be unique. Back references use the syntax (?P=name) and recursive calls use
3498 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3499 numbers. The function pcre_fullinfo() can be used after compilation to extract
3500 a name/number map. There are three relevant calls:
3502 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3503 PCRE_INFO_NAMECOUNT yields the number of entries
3504 PCRE_INFO_NAMETABLE yields a pointer to the map.
3506 The map is a vector of fixed-size entries. The size of each entry depends on
3507 the length of the longest name used. The first two bytes of each entry are the
3508 group number, most significant byte first. There follows the corresponding
3509 name, zero terminated. The names are in alphabetical order.
3511 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3512 case instead of 255. Making it the same both with and without UTF-8 support
3513 means that the same test output works with both.
3515 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3516 calling malloc() with a zero argument.
3518 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3519 optimization. I've improved things by keeping a bitmap of backreferences with
3520 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3521 fact referenced, the optimization can be applied. It is unlikely that a
3522 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3523 the match to follow \n) will appear inside brackets with a number greater than
3524 31, but if it does, any back reference > 31 suppresses the optimization.
3526 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3527 of disabling numbered capturing parentheses. Any opening parenthesis that is
3528 not followed by ? behaves as if it were followed by ?: but named parentheses
3529 can still be used for capturing (and they will acquire numbers in the usual
3530 way).
3532 41. Redesigned the return codes from the match() function into yes/no/error so
3533 that errors can be passed back from deep inside the nested calls. A malloc
3534 failure while inside a recursive subpattern call now causes the
3535 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3537 42. It is now possible to set a limit on the number of times the match()
3538 function is called in a call to pcre_exec(). This facility makes it possible to
3539 limit the amount of recursion and backtracking, though not in a directly
3540 obvious way, because the match() function is used in a number of different
3541 circumstances. The count starts from zero for each position in the subject
3542 string (for non-anchored patterns). The default limit is, for compatibility, a
3543 large number, namely 10 000 000. You can change this in two ways:
3545 (a) When configuring PCRE before making, you can use --with-match-limit=n
3546 to set a default value for the compiled library.
3548 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3549 a different value is set. See 45 below.
3551 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3553 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3554 of things that can be changed at compile time. The first argument specifies
3555 what is wanted and the second points to where the information is to be placed.
3556 The current list of available information is:
3560 The output is an integer that is set to one if UTF-8 support is available;
3561 otherwise it is set to zero.
3565 The output is an integer that it set to the value of the code that is used for
3566 newline. It is either LF (10) or CR (13).
3570 The output is an integer that contains the number of bytes used for internal
3571 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3575 The output is an integer that contains the threshold above which the POSIX
3576 interface uses malloc() for output vectors. See item 31 above.
3580 The output is an unsigned integer that contains the default limit of the number
3581 of match() calls in a pcre_exec() execution. See 42 above.
3583 44. pcretest has been upgraded by the addition of the -C option. This causes it
3584 to extract all the available output from the new pcre_config() function, and to
3585 output it. The program then exits immediately.
3587 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3588 order to support additional features. One way would have been to define
3589 pcre_exec2() (for example) with extra arguments, but this would not have been
3590 extensible, and would also have required all calls to the original function to
3591 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3592 is used for passing in "extra" data from pcre_study().
3594 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3595 contains the following fields:
3597 flags a bitmap indicating which of the following fields are set
3598 study_data opaque data from pcre_study()
3599 match_limit a way of specifying a limit on match() calls for a specific
3600 call to pcre_exec()
3601 callout_data data for callouts (see 49 below)
3603 The flag bits are also defined in pcre.h, and are
3609 The pcre_study() function now returns one of these new pcre_extra blocks, with
3610 the actual study data pointed to by the study_data field, and the
3611 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3612 before. That is, this change is entirely upwards-compatible and requires no
3613 change to existing code.
3615 If you want to pass in additional data to pcre_exec(), you can either place it
3616 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3617 block.
3619 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3620 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3621 times with different match limits, until it finds the minimum value needed for
3622 pcre_exec() to complete. The value is then output. This can be instructive; for
3623 most simple matches the number is quite small, but for pathological cases it
3624 gets very large very quickly.
3626 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3627 returns the size of the data block pointed to by the study_data field in a
3628 pcre_extra block, that is, the value that was passed as the argument to
3629 pcre_malloc() when PCRE was getting memory in which to place the information
3630 created by pcre_study(). The fourth argument should point to a size_t variable.
3631 pcretest has been extended so that this information is shown after a successful
3632 pcre_study() call when information about the compiled regex is being displayed.
3634 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3635 because what follows is always an absolute path. (Later: it turns out that this
3636 is more than cosmetic for MinGW, because it doesn't like empty path
3637 components.)
3639 49. Some changes have been made to the callout feature (see 28 above):
3641 (i) A callout function now has three choices for what it returns:
3643 0 => success, carry on matching
3644 > 0 => failure at this point, but backtrack if possible
3645 < 0 => serious error, return this value from pcre_exec()
3647 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3648 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3649 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3650 use by callout functions. It will never be used by PCRE itself.
3652 (ii) The pcre_extra structure (see 45 above) has a void * field called
3653 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3654 pcre_callout_block structure has a field of the same name. The contents of
3655 the field passed in the pcre_extra structure are passed to the callout
3656 function in the corresponding field in the callout block. This makes it
3657 easier to use the same callout-containing regex from multiple threads. For
3658 testing, the pcretest program has a new data escape
3660 \C*n pass the number n (may be negative) as callout_data
3662 If the callout function in pcretest receives a non-zero value as
3663 callout_data, it returns that value.
3665 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3666 there were some redundant $(CFLAGS) in commands that are now specified as
3667 $(LINK), which already includes $(CFLAGS).
3669 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3670 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3671 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3672 one-byte characters throughout. Note that case-insensitive matching applies
3673 only to characters whose values are less than 256. PCRE doesn't support the
3674 notion of cases for higher-valued characters.
3676 (i) A character class whose characters are all within 0-255 is handled as
3677 a bit map, and the map is inverted for negative classes. Previously, a
3678 character > 255 always failed to match such a class; however it should
3679 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3681 (ii) A negated character class with a single character < 255 is coded as
3682 "not this character" (OP_NOT). This wasn't working properly when the test
3683 character was multibyte, either singly or repeated.
3685 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3686 mode, for example: \x{100}{2,3}.
3688 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3689 singly or repeated) now correctly test multibyte characters. However,
3690 PCRE doesn't recognize any characters with values greater than 255 as
3691 digits, spaces, or word characters. Such characters always match \D, \S,
3692 and \W, and never match \d, \s, or \w.
3694 (v) Classes may now contain characters and character ranges with values
3695 greater than 255. For example: [ab\x{100}-\x{400}].
3697 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3698 PCRE in UTF-8 mode.
3700 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3701 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3702 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3703 value.)
3705 53. The single man page has become too large. I have therefore split it up into
3706 a number of separate man pages. These also give rise to individual HTML pages;
3707 these are now put in a separate directory, and there is an index.html page that
3708 lists them all. Some hyperlinking between the pages has been installed.
3710 54. Added convenience functions for handling named capturing parentheses.
3712 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3713 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3714 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3715 are faulted.
3717 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3718 calling configure. These values are used when compiling the dftables.c program
3719 which is run to generate the source of the default character tables. They
3720 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3721 you will need to set these values.
3723 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3726 Version 3.9 02-Jan-02
3727 ---------------------
3729 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3731 2. If --disable-static was given, the building process failed when trying to
3732 build pcretest and pcregrep. (For some reason it was using libtool to compile
3733 them, which is not right, as they aren't part of the library.)
3736 Version 3.8 18-Dec-01
3737 ---------------------
3739 1. The experimental UTF-8 code was completely screwed up. It was packing the
3740 bytes in the wrong order. How dumb can you get?
3743 Version 3.7 29-Oct-01
3744 ---------------------
3746 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3747 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3748 this didn't happen under Solaris 8, where I normally test things.
3750 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3751 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3752 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3753 this fix an hour or so after the initial 3.7 release.)
3756 Version 3.6 23-Oct-01
3757 ---------------------
3759 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3760 offsets passed as NULL with zero offset count.
3762 2. The config.guess and config.sub files had not been updated when I moved to
3763 the latest autoconf.
3766 Version 3.5 15-Aug-01
3767 ---------------------
3769 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3770 had been forgotten.
3772 2. By using declared but undefined structures, we can avoid using "void"
3773 definitions in pcre.h while keeping the internal definitions of the structures
3774 private.
3776 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3777 user point of view, this means that both static and shared libraries are built
3778 by default, but this can be individually controlled. More of the work of
3779 handling this static/shared cases is now inside libtool instead of PCRE's make
3780 file.
3782 4. The pcretest utility is now installed along with pcregrep because it is
3783 useful for users (to test regexs) and by doing this, it automatically gets
3784 relinked by libtool. The documentation has been turned into a man page, so
3785 there are now .1, .txt, and .html versions in /doc.
3787 5. Upgrades to pcregrep:
3788 (i) Added long-form option names like gnu grep.
3789 (ii) Added --help to list all options with an explanatory phrase.
3790 (iii) Added -r, --recursive to recurse into sub-directories.
3791 (iv) Added -f, --file to read patterns from a file.
3793 6. pcre_exec() was referring to its "code" argument before testing that
3794 argument for NULL (and giving an error if it was NULL).
3796 7. Upgraded Makefile.in to allow for compiling in a different directory from
3797 the source directory.
3799 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3800 options bits, the pointer it was passed was to an int instead of to an unsigned
3801 long int. This mattered only on 64-bit systems.
3803 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3804 generated) instead of pcre.in, which it its source. Also made the same change
3805 in several of the .c files.
3807 10. A new release of gcc defines printf() as a macro, which broke pcretest
3808 because it had an ifdef in the middle of a string argument for printf(). Fixed
3809 by using separate calls to printf().
3811 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
3812 script, to force use of CR or LF instead of \n in the source. On non-Unix
3813 systems, the value can be set in config.h.
3815 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
3816 absolute limit. Changed the text of the error message to make this clear, and
3817 likewise updated the man page.
3819 13. The limit of 99 on the number of capturing subpatterns has been removed.
3820 The new limit is 65535, which I hope will not be a "real" limit.
3823 Version 3.4 22-Aug-00
3824 ---------------------
3826 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
3828 2. Diagnose condition (?(0) as an error instead of crashing on matching.
3831 Version 3.3 01-Aug-00
3832 ---------------------
3834 1. If an octal character was given, but the value was greater than \377, it
3835 was not getting masked to the least significant bits, as documented. This could
3836 lead to crashes in some systems.
3838 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
3839 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
3841 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
3842 These just pass their arguments on to (pcre_free)(), but they are provided
3843 because some uses of PCRE bind it to non-C systems that can call its functions,
3844 but cannot call free() or pcre_free() directly.
3846 4. Add "make test" as a synonym for "make check". Corrected some comments in
3847 the Makefile.
3849 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
3850 Makefile.
3852 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
3853 command called pgrep for grepping around the active processes.
3855 7. Added the beginnings of support for UTF-8 character strings.
3857 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
3858 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
3859 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
3860 out for the ar command.)
3863 Version 3.2 12-May-00
3864 ---------------------
3866 This is purely a bug fixing release.
3868 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
3869 of ZA. This was just one example of several cases that could provoke this bug,
3870 which was introduced by change 9 of version 2.00. The code for breaking
3871 infinite loops after an iteration that matches an empty string was't working
3872 correctly.
3874 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
3875 when matched against abbab (for example). After matching an empty string, it
3876 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
3877 caused it to match further down the string than it should.
3879 3. The code contained an inclusion of sys/types.h. It isn't clear why this
3880 was there because it doesn't seem to be needed, and it causes trouble on some
3881 systems, as it is not a Standard C header. It has been removed.
3883 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
3884 were reported on the Macintosh. The changes were from
3886 while ((c = *(++ptr)) != 0 && c != '\n');
3887 to
3888 while ((c = *(++ptr)) != 0 && c != '\n') ;
3890 Totally extraordinary, but if that's what it takes...
3892 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
3893 available. Added HAVE_BCOPY and an autoconf test for it; if neither
3894 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
3895 assumes the way PCRE uses memmove() (always moving upwards).
3897 6. PCRE is being used in one environment where strchr() is not available. There
3898 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
3899 faster code anyway.
3902 Version 3.1 09-Feb-00
3903 ---------------------
3905 The only change in this release is the fixing of some bugs in Makefile.in for
3906 the "install" target:
3908 (1) It was failing to install pcreposix.h.
3910 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
3913 Version 3.0 01-Feb-00
3914 ---------------------
3916 1. Add support for the /+ modifier to perltest (to output $` like it does in
3917 pcretest).
3919 2. Add support for the /g modifier to perltest.
3921 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
3922 matches null strings.
3924 4. Fix perltest so that it doesn't do unwanted things when fed an empty
3925 pattern. Perl treats empty patterns specially - it reuses the most recent
3926 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
3927 effect.
3929 5. The POSIX interface was broken in that it was just handing over the POSIX
3930 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
3931 required a bigger vector, with some working space on the end. This means that
3932 the POSIX wrapper now has to get and free some memory, and copy the results.
3934 6. Added some simple autoconf support, placing the test data and the
3935 documentation in separate directories, re-organizing some of the
3936 information files, and making it build pcre-config (a GNU standard). Also added
3937 libtool support for building PCRE as a shared library, which is now the
3938 default.
3940 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3941 09 are not valid octal constants. Single digits will be used for minor values
3942 less than 10.
3944 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3945 existing programs that set these in the POSIX interface can use PCRE without
3946 modification.
3948 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3949 return all that pcre_info() returns, plus additional data. The pcre_info()
3950 function is retained for compatibility, but is considered to be obsolete.
3952 10. Added experimental recursion feature (?R) to handle one common case that
3953 Perl 5.6 will be able to do with (?p{...}).
3955 11. Added support for POSIX character classes like [:alpha:], which Perl is
3956 adopting.
3959 Version 2.08 31-Aug-99
3960 ----------------------
3962 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3963 trying to match at the startoffset position, but instead was moving forward to
3964 the next newline as if a previous match had failed.
3966 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3967 and could get into a loop if a null string was matched other than at the start
3968 of the subject.
3970 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3971 be distinguished at compile time, and for completeness also added PCRE_DATE.
3973 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3974 in GnuWin32 environments.
3977 Version 2.07 29-Jul-99
3978 ----------------------
3980 1. The documentation is now supplied in plain text form and HTML as well as in
3981 the form of man page sources.
3983 2. C++ compilers don't like assigning (void *) values to other pointer types.
3984 In particular this affects malloc(). Although there is no problem in Standard
3985 C, I've put in casts to keep C++ compilers happy.
3987 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3988 should be (const char *).
3990 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3991 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3992 However, I haven't made this a standard facility. The documentation doesn't
3993 mention it, and the Makefile doesn't support it.
3995 5. The Makefile now contains an "install" target, with editable destinations at
3996 the top of the file. The pcretest program is not installed.
3998 6. pgrep -V now gives the PCRE version number and date.
4000 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4001 causing the entire string to be ignored, instead of just the last character.
4003 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4004 non-matching string, it can take a very, very long time, even for strings of
4005 quite modest length, because of the nested recursion. PCRE now does better in
4006 some of these cases. It does this by remembering the last required literal
4007 character in the pattern, and pre-searching the subject to ensure it is present
4008 before running the real match. In other words, it applies a heuristic to detect
4009 some types of certain failure quickly, and in the above example, if presented
4010 with a string that has no trailing " it gives "no match" very quickly.
4012 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4013 other alternatives are tried instead.
4016 Version 2.06 09-Jun-99
4017 ----------------------
4019 1. Change pcretest's output for amount of store used to show just the code
4020 space, because the remainder (the data block) varies in size between 32-bit and
4021 64-bit systems.
4023 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4024 start matching at. This allows lookbehinds to work when searching for multiple
4025 occurrences in a string.
4027 3. Added additional options to pcretest for testing multiple occurrences:
4029 /+ outputs the rest of the string that follows a match
4030 /g loops for multiple occurrences, using the new startoffset argument
4031 /G loops for multiple occurrences by passing an incremented pointer
4033 4. PCRE wasn't doing the "first character" optimization for patterns starting
4034 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4035 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4036 the letter 'x'. On long subject strings, this gives a significant speed-up.
4039 Version 2.05 21-Apr-99
4040 ----------------------
4042 1. Changed the type of magic_number from int to long int so that it works
4043 properly on 16-bit systems.
4045 2. Fixed a bug which caused patterns starting with .* not to work correctly
4046 when the subject string contained newline characters. PCRE was assuming
4047 anchoring for such patterns in all cases, which is not correct because .* will
4048 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4049 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4050 must be retried after every newline in the subject.
4053 Version 2.04 18-Feb-99
4054 ----------------------
4056 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4057 computation of the store needed to hold the pattern was incorrect (too large).
4058 If such patterns were nested a few deep, this could multiply and become a real
4059 problem.
4061 2. Added /M option to pcretest to show the memory requirement of a specific
4062 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4064 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4065 compiled in such a way that the backtracking after subsequent failure was
4066 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4067 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4070 Version 2.03 02-Feb-99
4071 ----------------------
4073 1. Fixed typo and small mistake in man page.
4075 2. Added 4th condition (GPL supersedes if conflict) and created separate
4076 LICENCE file containing the conditions.
4078 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4079 Perl, that is the internal \ allows the delimiter to be included in the
4080 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4081 the final delimiter, add \ to the end of the pattern (to test the error).
4083 4. Added the convenience functions for extracting substrings after a successful
4084 match. Updated pcretest to make it able to test these functions.
4087 Version 2.02 14-Jan-99
4088 ----------------------
4090 1. Initialized the working variables associated with each extraction so that
4091 their saving and restoring doesn't refer to uninitialized store.
4093 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4094 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4095 fix the problem.
4097 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4098 calls, and wasn't printing the correct value for compiling calls. Increased the
4099 default value of LOOPREPEAT, and the number of significant figures in the
4100 times.
4102 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4104 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4105 a building problem on Windows NT with a FAT file system.
4108 Version 2.01 21-Oct-98
4109 ----------------------
4111 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4112 to character tables built by pcre_maketables() in the current locale. If NULL
4113 is passed, the default tables are used.
4116 Version 2.00 24-Sep-98
4117 ----------------------
4119 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4120 it any more.
4122 2. Allow quantification of (?>) groups, and make it work correctly.
4124 3. The first character computation wasn't working for (?>) groups.
4126 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4127 end of the subject) and add 5.005's \z, which really does match only at the
4128 very end of the subject.
4130 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4132 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4133 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4134 localized options. All options to pcre_study() were also removed.
4136 7. Add other new features from 5.005:
4138 $(?<= positive lookbehind
4139 $(?<! negative lookbehind
4140 (?imsx-imsx) added the unsetting capability
4141 such a setting is global if at outer level; local otherwise
4142 (?imsx-imsx:) non-capturing groups with option setting
4143 (?(cond)re|re) conditional pattern matching
4145 A backreference to itself in a repeated group matches the previous
4146 captured string.
4148 8. General tidying up of studying (both automatic and via "study")
4149 consequential on the addition of new assertions.
4151 9. As in 5.005, unlimited repeated groups that could match an empty substring
4152 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4153 runtime if any iteration does actually match an empty substring.
4155 10. Include the RunTest script in the distribution.
4157 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4158 discrepancies, some of which were old and were also with respect to 5.004. They
4159 have now been fixed.
4162 Version 1.09 28-Apr-98
4163 ----------------------
4165 1. A negated single character class followed by a quantifier with a minimum
4166 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4167 program crashes, or just wrong answers. This did not apply to negated classes
4168 containing more than one character, or to minima other than one.
4171 Version 1.08 27-Mar-98
4172 ----------------------
4174 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4176 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4177 latter must appear before anything that relies on it in the pattern.
4180 Version 1.07 16-Feb-98
4181 ----------------------
4183 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4184 repeat of a potentially empty string).
4187 Version 1.06 23-Jan-98
4188 ----------------------
4190 1. Added Markus Oberhumer's little patches for C++.
4192 2. Literal strings longer than 255 characters were broken.
4195 Version 1.05 23-Dec-97
4196 ----------------------
4198 1. Negated character classes containing more than one character were failing if
4199 PCRE_CASELESS was set at run time.
4202 Version 1.04 19-Dec-97
4203 ----------------------
4205 1. Corrected the man page, where some "const" qualifiers had been omitted.
4207 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4208 input syntax.
4210 3. Fixed memory leak which occurred when a regex with back references was
4211 matched with an offsets vector that wasn't big enough. The temporary memory
4212 that is used in this case wasn't being freed if the match failed.
4214 4. Tidied pcretest to ensure it frees memory that it gets.
4216 5. Temporary memory was being obtained in the case where the passed offsets
4217 vector was exactly big enough.
4219 6. Corrected definition of offsetof() from change 5 below.
4221 7. I had screwed up change 6 below and broken the rules for the use of
4222 setjmp(). Now fixed.
4225 Version 1.03 18-Dec-97
4226 ----------------------
4228 1. A erroneous regex with a missing opening parenthesis was correctly
4229 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4230 on some systems.
4232 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4233 it was reported that one broken compiler failed on the former because "code" is
4234 also an independent variable.
4236 3. The erroneous regex a[]b caused an array overrun reference.
4238 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4239 fail on data ending with that character. (It was going on too far, and checking
4240 the next character, typically a binary zero.) This was specific to the
4241 optimized code for single-character negative classes.
4243 5. Added a contributed patch from the TIN world which does the following:
4245 + Add an undef for memmove, in case the the system defines a macro for it.
4247 + Add a definition of offsetof(), in case there isn't one. (I don't know
4248 the reason behind this - offsetof() is part of the ANSI standard - but
4249 it does no harm).
4251 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4252 most of the places where whitespace preceded '#'. I have given up and
4253 allowed the remaining 2 cases to be at the margin.
4255 + Rename some variables in pcre to eliminate shadowing. This seems very
4256 pedantic, but does no harm, of course.
4258 6. Moved the call to setjmp() into its own function, to get rid of warnings
4259 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4261 7. Constructs such as \d{8,} were compiling into the equivalent of
4262 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4263 outcome, but in this particular case used more store than had been allocated,
4264 which caused the bug to be discovered because it threw up an internal error.
4266 8. The debugging code in both pcre and pcretest for outputting the compiled
4267 form of a regex was going wrong in the case of back references followed by
4268 curly-bracketed repeats.
4271 Version 1.02 12-Dec-97
4272 ----------------------
4274 1. Typos in pcre.3 and comments in the source fixed.
4276 2. Applied a contributed patch to get rid of places where it used to remove
4277 'const' from variables, and fixed some signed/unsigned and uninitialized
4278 variable warnings.
4280 3. Added the "runtest" target to Makefile.
4282 4. Set default compiler flag to -O2 rather than just -O.
4285 Version 1.01 19-Nov-97
4286 ----------------------
4288 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4289 like /([ab]*)*/, that is, for classes with more than one character in them.
4291 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4292 as /((?>a*))*/ (a PCRE_EXTRA facility).
4295 Version 1.00 18-Nov-97
4296 ----------------------
4298 1. Added compile-time macros to support systems such as SunOS4 which don't have
4299 memmove() or strerror() but have other things that can be used instead.
4301 2. Arranged that "make clean" removes the executables.
4304 Version 0.99 27-Oct-97
4305 ----------------------
4307 1. Fixed bug in code for optimizing classes with only one character. It was
4308 initializing a 32-byte map regardless, which could cause it to run off the end
4309 of the memory it had got.
4311 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4314 Version 0.98 22-Oct-97
4315 ----------------------
4317 1. Fixed bug in code for handling temporary memory usage when there are more
4318 back references than supplied space in the ovector. This could cause segfaults.
4321 Version 0.97 21-Oct-97
4322 ----------------------
4324 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4326 2. Optimized negated single characters not to use a bit map.
4328 3. Brought error texts together as macro definitions; clarified some of them;
4329 fixed one that was wrong - it said "range out of order" when it meant "invalid
4330 escape sequence".
4332 4. Changed some char * arguments to const char *.
4334 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4336 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4337 pcretest.
4340 Version 0.96 16-Oct-97
4341 ----------------------
4343 1. Added a simple "pgrep" utility to the distribution.
4345 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4346 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4347 where "ddd" means "one or more decimal digits".
4349 3. Fixed serious bug. If a pattern had a back reference, but the call to
4350 pcre_exec() didn't supply a large enough ovector to record the related
4351 identifying subpattern, the match always failed. PCRE now remembers the number
4352 of the largest back reference, and gets some temporary memory in which to save
4353 the offsets during matching if necessary, in order to ensure that
4354 backreferences always work.
4356 4. Increased the compatibility with Perl in a number of ways:
4358 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4359 to request this handling. The option can be set at compile or exec time.
4361 (b) $ matches before a terminating newline by default; an option
4362 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4363 mode). The option can be set at compile or exec time.
4365 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4366 the same as Perl's. If the decimal number it represents is less than 10
4367 or there aren't that many previous left capturing parentheses, an octal
4368 escape is read. Inside a character class, it's always an octal escape,
4369 even if it is a single digit.
4371 (d) An escaped but undefined alphabetic character is taken as a literal,
4372 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4373 escapes.
4375 (e) {0} is now permitted. (The previous item is removed from the compiled
4376 pattern).
4378 5. Changed all the names of code files so that the basic parts are no longer
4379 than 10 characters, and abolished the teeny "globals.c" file.
4381 6. Changed the handling of character classes; they are now done with a 32-byte
4382 bit map always.
4384 7. Added the -d and /D options to pcretest to make it possible to look at the
4385 internals of compilation without having to recompile pcre.
4388 Version 0.95 23-Sep-97
4389 ----------------------
4391 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4392 \x20 at the start of a run of normal characters. These were being treated as
4393 real characters, instead of the source characters being re-checked.
4396 Version 0.94 18-Sep-97
4397 ----------------------
4399 1. The functions are now thread-safe, with the caveat that the global variables
4400 containing pointers to malloc() and free() or alternative functions are the
4401 same for all threads.
4403 2. Get pcre_study() to generate a bitmap of initial characters for non-
4404 anchored patterns when this is possible, and use it if passed to pcre_exec().
4407 Version 0.93 15-Sep-97
4408 ----------------------
4410 1. /(b)|(:+)/ was computing an incorrect first character.
4412 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4413 but not actually doing anything yet.
4415 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4416 as Perl does (e.g. [-az] or [az-]).
4418 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4419 all possible positions.
4421 5. Split up into different modules to avoid including unneeded functions in a
4422 compiled binary. However, compile and exec are still in one module. The "study"
4423 function is split off.
4425 6. The character tables are now in a separate module whose source is generated
4426 by an auxiliary program - but can then be edited by hand if required. There are
4427 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4428 toupper() in the code.
4430 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4431 make them global. Abolish the function for setting them, as the caller can now
4432 set them directly.
4435 Version 0.92 11-Sep-97
4436 ----------------------
4438 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4439 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4441 2. Caseless matching was not working in character classes if the characters in
4442 the pattern were in upper case.
4444 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4446 4. Make PCRE_ANCHORED public and accept as a compile option.
4448 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4449 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4450 pass them.
4452 6. Give an error if bad option bits passed at compile or run time.
4454 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4455 pcretest to cause it to pass that flag.
4457 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4458 options, and the first character, if set.
4460 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4463 Version 0.91 10-Sep-97
4464 ----------------------
4466 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4467 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4469 2. PCRE was looping on encountering an indefinitely repeated back reference to
4470 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4471 Perl does - treats the match as successful.
4473 ****


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