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Experimental stack size determination.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.30
5 ------------
6
7 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
8 name is defined in ctype.h.
9
10 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
11 only in quite long subpatterns.
12
13 3. Removed the function pcre_info(), which has been obsolete and deprecated
14 since it was replaced by pcre_fullinfo() in February 2000.
15
16 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
17 match a (*MARK), and the match failed at the start of the subject, a
18 reference to memory before the start of the subject could occur. This bug
19 was introduced by fix 17 of release 8.21.
20
21 5. A reference to an unset group with zero minimum repetition was giving
22 totally wrong answers (in non-JavaScript-compatibility mode). For example,
23 /(another)?(\1?)test/ matched against "hello world test". This bug was
24 introduced in release 8.13.
25
26 6. Add support for 16-bit character strings (a large amount of work involving
27 many changes and refactorings).
28
29 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
30 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
31 from a file.
32
33 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
34 rounding is not applied in this particular case).
35
36 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
37 if they appear, or are escaped, in patterns.
38
39 10. Get rid of a number of -Wunused-but-set-variable warnings.
40
41 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
42 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
43 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
44 also returns the mark "x". This bug applied to capturing parentheses,
45 non-capturing parentheses, and atomic parentheses. It also applied to some
46 assertions.
47
48 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
49 information out of configure.ac instead of relying on pcre.h.generic, which
50 is not stored in the repository.
51
52 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
53 -lreadline.
54
55 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
56
57 15. Applied Graycode's patch to put the top-level frame on the stack rather
58 than the heap when not using the stack for recursion. This gives a
59 performance improvement in many cases when recursion is not deep.
60
61 16. Experimental code added to "pcretest -C" to output the stack frame size.
62
63
64 Version 8.21 12-Dec-2011
65 ------------------------
66
67 1. Updating the JIT compiler.
68
69 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
70 are added as well.
71
72 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
73 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
74 calling _pcre_jit_exec. Some extra comments are added.
75
76 4. (*MARK) settings inside atomic groups that do not contain any capturing
77 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
78 was introduced by change 18 for 8.20.
79
80 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
81 ECMA-262 standard.
82
83 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
84 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
85 This bug was probably introduced by change 9 of 8.13.
86
87 7. While fixing 6 above, I noticed that a number of other items were being
88 incorrectly rejected as "not fixed length". This arose partly because newer
89 opcodes had not been added to the fixed-length checking code. I have (a)
90 corrected the bug and added tests for these items, and (b) arranged for an
91 error to occur if an unknown opcode is encountered while checking for fixed
92 length instead of just assuming "not fixed length". The items that were
93 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
94 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
95 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
96
97 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
98 being incorrectly compiled and would have given unpredicatble results.
99
100 9. A possessively repeated subpattern with minimum repeat count greater than
101 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
102 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
103 the first (A) could occur when it should not.
104
105 10. Add a cast and remove a redundant test from the code.
106
107 11. JIT should use pcre_malloc/pcre_free for allocation.
108
109 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
110 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
111 is anything other than /usr, -L is still shown).
112
113 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
114
115 14. Perl does not support \N without a following name in a [] class; PCRE now
116 also gives an error.
117
118 15. If a forward reference was repeated with an upper limit of around 2000,
119 it caused the error "internal error: overran compiling workspace". The
120 maximum number of forward references (including repeats) was limited by the
121 internal workspace, and dependent on the LINK_SIZE. The code has been
122 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
123 the default depends on LINK_SIZE. There is a new upper limit (for safety)
124 of around 200,000 forward references. While doing this, I also speeded up
125 the filling in of repeated forward references.
126
127 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
128 incorrectly expecting the subject to contain another "a" after the start.
129
130 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
131 in the match, the SKIP should be ignored. This was not happening; instead
132 the SKIP was being treated as NOMATCH. For patterns such as
133 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
134 tested.
135
136 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
137 now much more compatible with Perl, in particular in cases where the result
138 is a non-match for a non-anchored pattern. For example, if
139 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
140 "m", where previously it did not return a name. A side effect of this
141 change is that for partial matches, the last encountered mark name is
142 returned, as for non matches. A number of tests that were previously not
143 Perl-compatible have been moved into the Perl-compatible test files. The
144 refactoring has had the pleasing side effect of removing one argument from
145 the match() function, thus reducing its stack requirements.
146
147 19. If the /S+ option was used in pcretest to study a pattern using JIT,
148 subsequent uses of /S (without +) incorrectly behaved like /S+.
149
150 21. Retrieve executable code size support for the JIT compiler and fixing
151 some warnings.
152
153 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
154 not work when the shorter character appeared right at the end of the
155 subject string.
156
157 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
158 systems.
159
160 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
161 output it when the /M option is used in pcretest.
162
163 25. The CheckMan script was not being included in the distribution. Also, added
164 an explicit "perl" to run Perl scripts from the PrepareRelease script
165 because this is reportedly needed in Windows.
166
167 26. If study data was being save in a file and studying had not found a set of
168 "starts with" bytes for the pattern, the data written to the file (though
169 never used) was taken from uninitialized memory and so caused valgrind to
170 complain.
171
172 27. Updated RunTest.bat as provided by Sheri Pierce.
173
174 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
175
176 29. Computation of memory usage for the table of capturing group names was
177 giving an unnecessarily large value.
178
179
180 Version 8.20 21-Oct-2011
181 ------------------------
182
183 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
184 a POSIX class. After further experiments with Perl, which convinced me that
185 Perl has bugs and confusions, a closing square bracket is no longer allowed
186 in a POSIX name. This bug also affected patterns with classes that started
187 with full stops.
188
189 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
190 captured substring, but while checking the failing first alternative,
191 substring 1 is temporarily captured. If the output vector supplied to
192 pcre_exec() was not big enough for this capture, the yield of the function
193 was still zero ("insufficient space for captured substrings"). This cannot
194 be totally fixed without adding another stack variable, which seems a lot
195 of expense for a edge case. However, I have improved the situation in cases
196 such as /(a)(b)x|abc/ matched against "abc", where the return code
197 indicates that fewer than the maximum number of slots in the ovector have
198 been set.
199
200 3. Related to (2) above: when there are more back references in a pattern than
201 slots in the output vector, pcre_exec() uses temporary memory during
202 matching, and copies in the captures as far as possible afterwards. It was
203 using the entire output vector, but this conflicts with the specification
204 that only 2/3 is used for passing back captured substrings. Now it uses
205 only the first 2/3, for compatibility. This is, of course, another edge
206 case.
207
208 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
209 main code base, and can be used by building with --enable-jit. When this is
210 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
211 runtime --no-jit option is given.
212
213 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
214 ovector, the return from the function was zero, implying that there were
215 other matches that did not fit. The correct "exactly full" value is now
216 returned.
217
218 6. If a subpattern that was called recursively or as a subroutine contained
219 (*PRUNE) or any other control that caused it to give a non-standard return,
220 invalid errors such as "Error -26 (nested recursion at the same subject
221 position)" or even infinite loops could occur.
222
223 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
224 computing the minimum length on reaching *ACCEPT, and so ended up with the
225 wrong value of 1 rather than 0. Further investigation indicates that
226 computing a minimum subject length in the presence of *ACCEPT is difficult
227 (think back references, subroutine calls), and so I have changed the code
228 so that no minimum is registered for a pattern that contains *ACCEPT.
229
230 8. If (*THEN) was present in the first (true) branch of a conditional group,
231 it was not handled as intended. [But see 16 below.]
232
233 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
234 Sheri Pierce.
235
236 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
237 the first byte in a match must be "a".
238
239 11. Change 17 for 8.13 increased the recursion depth for patterns like
240 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
241 pattern contains any instances of (*THEN). If it does not, the old
242 optimizations are restored. It would be nice to do this on a per-group
243 basis, but at the moment that is not feasible.
244
245 12. In some environments, the output of pcretest -C is CRLF terminated. This
246 broke RunTest's code that checks for the link size. A single white space
247 character after the value is now allowed for.
248
249 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
250 For "fr", it uses the Windows-specific input and output files.
251
252 14. If (*THEN) appeared in a group that was called recursively or as a
253 subroutine, it did not work as intended. [But see next item.]
254
255 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
256 pattern fragments (but not containing any | characters). If A and B are
257 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
258 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
259 D. In other words, Perl considers parentheses that do not contain any |
260 characters to be part of a surrounding alternative, whereas PCRE was
261 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
262 differently. PCRE now behaves in the same way as Perl, except in the case
263 of subroutine/recursion calls such as (?1) which have in any case always
264 been different (but PCRE had them first :-).
265
266 16. Related to 15 above: Perl does not treat the | in a conditional group as
267 creating alternatives. Such a group is treated in the same way as an
268 ordinary group without any | characters when processing (*THEN). PCRE has
269 been changed to match Perl's behaviour.
270
271 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
272 RunGrepTest script failed.
273
274 18. Change 22 for version 13 caused atomic groups to use more stack. This is
275 inevitable for groups that contain captures, but it can lead to a lot of
276 stack use in large patterns. The old behaviour has been restored for atomic
277 groups that do not contain any capturing parentheses.
278
279 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
280 suppress the check for a minimum subject length at run time. (If it was
281 given to pcre_exec() or pcre_dfa_exec() it did work.)
282
283 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
284 fail to work when decoding hex characters in data strings in EBCDIC
285 environments.
286
287 21. It appears that in at least one Mac OS environment, the isxdigit() function
288 is implemented as a macro that evaluates to its argument more than once,
289 contravening the C 90 Standard (I haven't checked a later standard). There
290 was an instance in pcretest which caused it to go wrong when processing
291 \x{...} escapes in subject strings. The has been rewritten to avoid using
292 things like p++ in the argument of isxdigit().
293
294
295 Version 8.13 16-Aug-2011
296 ------------------------
297
298 1. The Unicode data tables have been updated to Unicode 6.0.0.
299
300 2. Two minor typos in pcre_internal.h have been fixed.
301
302 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
303 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
304 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
305
306 4. There were a number of related bugs in the code for matching backrefences
307 caselessly in UTF-8 mode when codes for the characters concerned were
308 different numbers of bytes. For example, U+023A and U+2C65 are an upper
309 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
310 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
311 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
312 2-byte code at the end of the subject (it thought there wasn't enough data
313 left).
314
315 5. Comprehensive information about what went wrong is now returned by
316 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
317 as the output vector has at least 2 elements. The offset of the start of
318 the failing character and a reason code are placed in the vector.
319
320 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
321 now returned is for the first byte of the failing character, instead of the
322 last byte inspected. This is an incompatible change, but I hope it is small
323 enough not to be a problem. It makes the returned offset consistent with
324 pcre_exec() and pcre_dfa_exec().
325
326 7. pcretest now gives a text phrase as well as the error number when
327 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
328 failure, the offset and reason code are output.
329
330 8. When \R was used with a maximizing quantifier it failed to skip backwards
331 over a \r\n pair if the subsequent match failed. Instead, it just skipped
332 back over a single character (\n). This seems wrong (because it treated the
333 two characters as a single entity when going forwards), conflicts with the
334 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
335 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
336 has been changed.
337
338 9. Some internal refactoring has changed the processing so that the handling
339 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
340 time (the PCRE_DOTALL option was changed this way some time ago: version
341 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
342 which was always a bit of a fudge. It also means that there is one less
343 argument for the match() function, which reduces its stack requirements
344 slightly. This change also fixes an incompatibility with Perl: the pattern
345 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
346
347 10. More internal refactoring has drastically reduced the number of recursive
348 calls to match() for possessively repeated groups such as (abc)++ when
349 using pcre_exec().
350
351 11. While implementing 10, a number of bugs in the handling of groups were
352 discovered and fixed:
353
354 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
355 (a|)*(?1) gave a compile-time internal error.
356 ((a|)+)+ did not notice that the outer group could match an empty string.
357 (^a|^)+ was not marked as anchored.
358 (.*a|.*)+ was not marked as matching at start or after a newline.
359
360 12. Yet more internal refactoring has removed another argument from the match()
361 function. Special calls to this function are now indicated by setting a
362 value in a variable in the "match data" data block.
363
364 13. Be more explicit in pcre_study() instead of relying on "default" for
365 opcodes that mean there is no starting character; this means that when new
366 ones are added and accidentally left out of pcre_study(), testing should
367 pick them up.
368
369 14. The -s option of pcretest has been documented for ages as being an old
370 synonym of -m (show memory usage). I have changed it to mean "force study
371 for every regex", that is, assume /S for every regex. This is similar to -i
372 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
373 using it. It makes it easier to run collections of tests with and without
374 study enabled, and thereby test pcre_study() more easily. All the standard
375 tests are now run with and without -s (but some patterns can be marked as
376 "never study" - see 20 below).
377
378 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
379 restoration of the capturing data to the outer values was not happening
380 correctly.
381
382 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
383 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
384 pattern had matched an empty string, and so incorrectly returned a no
385 match.
386
387 17. There was optimizing code for the last branch of non-capturing parentheses,
388 and also for the obeyed branch of a conditional subexpression, which used
389 tail recursion to cut down on stack usage. Unfortunately, now that there is
390 the possibility of (*THEN) occurring in these branches, tail recursion is
391 no longer possible because the return has to be checked for (*THEN). These
392 two optimizations have therefore been removed. [But see 8.20/11 above.]
393
394 18. If a pattern containing \R was studied, it was assumed that \R always
395 matched two bytes, thus causing the minimum subject length to be
396 incorrectly computed because \R can also match just one byte.
397
398 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
399 was incorrectly computed.
400
401 20. If /S is present twice on a test pattern in pcretest input, it now
402 *disables* studying, thereby overriding the use of -s on the command line
403 (see 14 above). This is necessary for one or two tests to keep the output
404 identical in both cases.
405
406 21. When (*ACCEPT) was used in an assertion that matched an empty string and
407 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
408
409 22. When an atomic group that contained a capturing parenthesis was
410 successfully matched, but the branch in which it appeared failed, the
411 capturing was not being forgotten if a higher numbered group was later
412 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
413 group 1 to "a", when in fact it should be unset. This applied to multi-
414 branched capturing and non-capturing groups, repeated or not, and also to
415 positive assertions (capturing in negative assertions does not happen
416 in PCRE) and also to nested atomic groups.
417
418 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
419 subject after a captured substring, to make it easier to tell which of a
420 number of identical substrings has been captured.
421
422 24. The way atomic groups are processed by pcre_exec() has been changed so that
423 if they are repeated, backtracking one repetition now resets captured
424 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
425 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
426 "aaa". Previously, it would have been "a". As part of this code
427 refactoring, the way recursive calls are handled has also been changed.
428
429 25. If an assertion condition captured any substrings, they were not passed
430 back unless some other capturing happened later. For example, if
431 (?(?=(a))a) was matched against "a", no capturing was returned.
432
433 26. When studying a pattern that contained subroutine calls or assertions,
434 the code for finding the minimum length of a possible match was handling
435 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
436 group 1 called group 2 while simultaneously a separate group 2 called group
437 1). A stack overflow occurred in this case. I have fixed this by limiting
438 the recursion depth to 10.
439
440 27. Updated RunTest.bat in the distribution to the version supplied by Tom
441 Fortmann. This supports explicit test numbers on the command line, and has
442 argument validation and error reporting.
443
444 28. An instance of \X with an unlimited repeat could fail if at any point the
445 first character it looked at was a mark character.
446
447 29. Some minor code refactoring concerning Unicode properties and scripts
448 should reduce the stack requirement of match() slightly.
449
450 30. Added the '=' option to pcretest to check the setting of unused capturing
451 slots at the end of the pattern, which are documented as being -1, but are
452 not included in the return count.
453
454 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
455 compiled something random. Now it gives a compile-time error (as does
456 Perl).
457
458 32. A *MARK encountered during the processing of a positive assertion is now
459 recorded and passed back (compatible with Perl).
460
461 33. If --only-matching or --colour was set on a pcregrep call whose pattern
462 had alternative anchored branches, the search for a second match in a line
463 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
464 matched the line "0102" twice. The same bug affected patterns that started
465 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
466 twice.
467
468 34. Previously, PCRE did not allow quantification of assertions. However, Perl
469 does, and because of capturing effects, quantifying parenthesized
470 assertions may at times be useful. Quantifiers are now allowed for
471 parenthesized assertions.
472
473 35. A minor code tidy in pcre_compile() when checking options for \R usage.
474
475 36. \g was being checked for fancy things in a character class, when it should
476 just be a literal "g".
477
478 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
479 appearance of a nested POSIX class supersedes an apparent external class.
480 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
481 unescaped square brackets may also appear as part of class names. For
482 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
483 more like Perl. (But see 8.20/1 above.)
484
485 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
486 was because it thought it was \N{name}, which is not supported).
487
488 39. Add minix to OS list not supporting the -S option in pcretest.
489
490 40. PCRE tries to detect cases of infinite recursion at compile time, but it
491 cannot analyze patterns in sufficient detail to catch mutual recursions
492 such as ((?1))((?2)). There is now a runtime test that gives an error if a
493 subgroup is called recursively as a subpattern for a second time at the
494 same position in the subject string. In previous releases this might have
495 been caught by the recursion limit, or it might have run out of stack.
496
497 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
498 happen only once. PCRE was, however incorrectly giving a compile time error
499 "recursive call could loop indefinitely" because it cannot analyze the
500 pattern in sufficient detail. The compile time test no longer happens when
501 PCRE is compiling a conditional subpattern, but actual runaway loops are
502 now caught at runtime (see 40 above).
503
504 42. It seems that Perl allows any characters other than a closing parenthesis
505 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
506 has been changed to be the same.
507
508 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
509 as not to get warnings when autogen.sh is called. Also changed
510 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
511
512 44. To help people who use pcregrep to scan files containing exceedingly long
513 lines, the following changes have been made:
514
515 (a) The default value of the buffer size parameter has been increased from
516 8K to 20K. (The actual buffer used is three times this size.)
517
518 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
519 PCRE is built.
520
521 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
522 to be set at run time.
523
524 (d) Numerical values in pcregrep options can be followed by K or M, for
525 example --buffer-size=50K.
526
527 (e) If a line being scanned overflows pcregrep's buffer, an error is now
528 given and the return code is set to 2.
529
530 45. Add a pointer to the latest mark to the callout data block.
531
532 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
533 partial match of an empty string instead of no match. This was specific to
534 the use of ".".
535
536 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
537 complete match instead of a partial match. This bug was dependent on both
538 the PCRE_UTF8 and PCRE_DOTALL options being set.
539
540 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
541 starting byte set, because \b was not being ignored.
542
543
544 Version 8.12 15-Jan-2011
545 ------------------------
546
547 1. Fixed some typos in the markup of the man pages, and wrote a script that
548 checks for such things as part of the documentation building process.
549
550 2. On a big-endian 64-bit system, pcregrep did not correctly process the
551 --match-limit and --recursion-limit options (added for 8.11). In
552 particular, this made one of the standard tests fail. (The integer value
553 went into the wrong half of a long int.)
554
555 3. If the --colour option was given to pcregrep with -v (invert match), it
556 did strange things, either producing crazy output, or crashing. It should,
557 of course, ignore a request for colour when reporting lines that do not
558 match.
559
560 4. Another pcregrep bug caused similar problems if --colour was specified with
561 -M (multiline) and the pattern match finished with a line ending.
562
563 5. In pcregrep, when a pattern that ended with a literal newline sequence was
564 matched in multiline mode, the following line was shown as part of the
565 match. This seems wrong, so I have changed it.
566
567 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
568 the check for further matches in the same line (so they could be coloured)
569 to overrun the end of the current line. If another match was found, it was
570 incorrectly shown (and then shown again when found in the next line).
571
572 7. If pcregrep was compiled under Windows, there was a reference to the
573 function pcregrep_exit() before it was defined. I am assuming this was
574 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
575 reported by a user. I've moved the definition above the reference.
576
577
578 Version 8.11 10-Dec-2010
579 ------------------------
580
581 1. (*THEN) was not working properly if there were untried alternatives prior
582 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
583 backtracked to try for "b" instead of moving to the next alternative branch
584 at the same level (in this case, to look for "c"). The Perl documentation
585 is clear that when (*THEN) is backtracked onto, it goes to the "next
586 alternative in the innermost enclosing group".
587
588 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
589 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
590 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
591 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
592 (*THEN).
593
594 3. If \s appeared in a character class, it removed the VT character from
595 the class, even if it had been included by some previous item, for example
596 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
597 of \s, but is part of the POSIX "space" class.)
598
599 4. A partial match never returns an empty string (because you can always
600 match an empty string at the end of the subject); however the checking for
601 an empty string was starting at the "start of match" point. This has been
602 changed to the "earliest inspected character" point, because the returned
603 data for a partial match starts at this character. This means that, for
604 example, /(?<=abc)def/ gives a partial match for the subject "abc"
605 (previously it gave "no match").
606
607 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
608 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
609 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
610 has an implication that the given string is incomplete (because a partial
611 match is preferred over a full match). For this reason, these items now
612 give a partial match in this situation. [Aside: previously, the one case
613 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
614 match rather than a full match, which was wrong by the old rules, but is
615 now correct.]
616
617 6. There was a bug in the handling of #-introduced comments, recognized when
618 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
619 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
620 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
621 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
622 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
623 places in pcre_compile().
624
625 7. Related to (6) above, when pcre_compile() was skipping #-introduced
626 comments when looking ahead for named forward references to subpatterns,
627 the only newline sequence it recognized was NL. It now handles newlines
628 according to the set newline convention.
629
630 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
631 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
632 cater for a lack of strerror(). These oversights have been fixed.
633
634 9. Added --match-limit and --recursion-limit to pcregrep.
635
636 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
637
638 11. When the -o option was used, pcregrep was setting a return code of 1, even
639 when matches were found, and --line-buffered was not being honoured.
640
641 12. Added an optional parentheses number to the -o and --only-matching options
642 of pcregrep.
643
644 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
645 can match an empty string. The code to do it in pcretest and pcredemo
646 needed fixing:
647
648 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
649 only one byte after an empty string match just before CRLF (this case
650 just got forgotten; "any" and "anycrlf" were OK).
651
652 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
653 mode when an empty string match preceded an ASCII character followed by
654 a non-ASCII character. (The code for advancing by one character rather
655 than one byte was nonsense.)
656
657 (c) The pcredemo.c sample program did not have any code at all to handle
658 the cases when CRLF is a valid newline sequence.
659
660 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
661 as a starting offset was within the subject string. There is now a new
662 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
663 negative or greater than the length of the string. In order to test this,
664 pcretest is extended to allow the setting of negative starting offsets.
665
666 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
667 starting offset points to the beginning of a UTF-8 character was
668 unnecessarily clumsy. I tidied it up.
669
670 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
671 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
672
673 17. Nobody had reported that the --include_dir option, which was added in
674 release 7.7 should have been called --include-dir (hyphen, not underscore)
675 for compatibility with GNU grep. I have changed it to --include-dir, but
676 left --include_dir as an undocumented synonym, and the same for
677 --exclude-dir, though that is not available in GNU grep, at least as of
678 release 2.5.4.
679
680 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
681 characters from a string of bytes) have been redefined so as not to use
682 loops, in order to improve performance in some environments. At the same
683 time, I abstracted some of the common code into auxiliary macros to save
684 repetition (this should not affect the compiled code).
685
686 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
687 compile-time error is now given if \c is not followed by an ASCII
688 character, that is, a byte less than 128. (In EBCDIC mode, the code is
689 different, and any byte value is allowed.)
690
691 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
692 START_OPTIMIZE option, which is now allowed at compile time - but just
693 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
694 to pcregrep and other applications that have no direct access to PCRE
695 options. The new /Y option in pcretest sets this option when calling
696 pcre_compile().
697
698 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
699 back references. Groups containing recursive back references were forced to
700 be atomic by that change, but in the case of named groups, the amount of
701 memory required was incorrectly computed, leading to "Failed: internal
702 error: code overflow". This has been fixed.
703
704 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
705 pcretest.c, to avoid build problems in some Borland environments.
706
707
708 Version 8.10 25-Jun-2010
709 ------------------------
710
711 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
712 THEN.
713
714 2. (*ACCEPT) was not working when inside an atomic group.
715
716 3. Inside a character class, \B is treated as a literal by default, but
717 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
718 causes the error). The code is unchanged, but I tidied the documentation.
719
720 4. Inside a character class, PCRE always treated \R and \X as literals,
721 whereas Perl faults them if its -w option is set. I have changed PCRE so
722 that it faults them when PCRE_EXTRA is set.
723
724 5. Added support for \N, which always matches any character other than
725 newline. (It is the same as "." when PCRE_DOTALL is not set.)
726
727 6. When compiling pcregrep with newer versions of gcc which may have
728 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
729 declared with attribute warn_unused_result" were given. Just casting the
730 result to (void) does not stop the warnings; a more elaborate fudge is
731 needed. I've used a macro to implement this.
732
733 7. Minor change to pcretest.c to avoid a compiler warning.
734
735 8. Added four artifical Unicode properties to help with an option to make
736 \s etc use properties (see next item). The new properties are: Xan
737 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
738
739 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
740 use Unicode properties. (*UCP) at the start of a pattern can be used to set
741 this option. Modified pcretest to add /W to test this facility. Added
742 REG_UCP to make it available via the POSIX interface.
743
744 10. Added --line-buffered to pcregrep.
745
746 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
747 studied, and the match started with a letter with a code point greater than
748 127 whose first byte was different to the first byte of the other case of
749 the letter, the other case of this starting letter was not recognized
750 (#976).
751
752 12. If a pattern that was studied started with a repeated Unicode property
753 test, for example, \p{Nd}+, there was the theoretical possibility of
754 setting up an incorrect bitmap of starting bytes, but fortunately it could
755 not have actually happened in practice until change 8 above was made (it
756 added property types that matched character-matching opcodes).
757
758 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
759 possible starting bytes for non-anchored patterns.
760
761 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
762 \R, and also a number of cases that involve Unicode properties, both
763 explicit and implicit when PCRE_UCP is set.
764
765 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
766 input, it could crash or give wrong results if characters with values
767 greater than 0xc0 were present in the subject string. (Detail: it assumed
768 UTF-8 input when processing these items.)
769
770 16. Added a lot of (int) casts to avoid compiler warnings in systems where
771 size_t is 64-bit (#991).
772
773 17. Added a check for running out of memory when PCRE is compiled with
774 --disable-stack-for-recursion (#990).
775
776 18. If the last data line in a file for pcretest does not have a newline on
777 the end, a newline was missing in the output.
778
779 19. The default pcre_chartables.c file recognizes only ASCII characters (values
780 less than 128) in its various bitmaps. However, there is a facility for
781 generating tables according to the current locale when PCRE is compiled. It
782 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
783 characters, are recognized by isspace() and therefore were getting set in
784 these tables, and indeed these tables seem to approximate to ISO 8859. This
785 caused a problem in UTF-8 mode when pcre_study() was used to create a list
786 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
787 which of course cannot start UTF-8 characters. I have changed the code so
788 that only real ASCII characters (less than 128) and the correct starting
789 bytes for UTF-8 encodings are set for characters greater than 127 when in
790 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
791 altogether.)
792
793 20. Added the /T option to pcretest so as to be able to run tests with non-
794 standard character tables, thus making it possible to include the tests
795 used for 19 above in the standard set of tests.
796
797 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
798 reference to a subpattern the other side of a comment that contains an
799 opening parenthesis caused either an internal compiling error, or a
800 reference to the wrong subpattern.
801
802
803 Version 8.02 19-Mar-2010
804 ------------------------
805
806 1. The Unicode data tables have been updated to Unicode 5.2.0.
807
808 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
809 configured.
810
811 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
812 original author of that file, following a query about its status.
813
814 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
815 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
816
817 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
818 quantifier applied to a forward-referencing subroutine call, could compile
819 incorrect code or give the error "internal error: previously-checked
820 referenced subpattern not found".
821
822 6. Both MS Visual Studio and Symbian OS have problems with initializing
823 variables to point to external functions. For these systems, therefore,
824 pcre_malloc etc. are now initialized to local functions that call the
825 relevant global functions.
826
827 7. There were two entries missing in the vectors called coptable and poptable
828 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
829 I've fixed the data, and added a kludgy way of testing at compile time that
830 the lengths are correct (equal to the number of opcodes).
831
832 8. Following on from 7, I added a similar kludge to check the length of the
833 eint vector in pcreposix.c.
834
835 9. Error texts for pcre_compile() are held as one long string to avoid too
836 much relocation at load time. To find a text, the string is searched,
837 counting zeros. There was no check for running off the end of the string,
838 which could happen if a new error number was added without updating the
839 string.
840
841 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
842
843 11. \K was not working if it appeared in an atomic group or in a group that
844 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
845 \K is "not well defined" if used in an assertion. PCRE now accepts it if
846 the assertion is positive, but not if it is negative.
847
848 12. Change 11 fortuitously reduced the size of the stack frame used in the
849 "match()" function of pcre_exec.c by one pointer. Forthcoming
850 implementation of support for (*MARK) will need an extra pointer on the
851 stack; I have reserved it now, so that the stack frame size does not
852 decrease.
853
854 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
855 item in branch that calls a recursion is a subroutine call - as in the
856 second branch in the above example - was incorrectly given the compile-
857 time error "recursive call could loop indefinitely" because pcre_compile()
858 was not correctly checking the subroutine for matching a non-empty string.
859
860 14. The checks for overrunning compiling workspace could trigger after an
861 overrun had occurred. This is a "should never occur" error, but it can be
862 triggered by pathological patterns such as hundreds of nested parentheses.
863 The checks now trigger 100 bytes before the end of the workspace.
864
865 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
866
867
868 Version 8.01 19-Jan-2010
869 ------------------------
870
871 1. If a pattern contained a conditional subpattern with only one branch (in
872 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
873 computed the wrong minimum data length (which is of course zero for such
874 subpatterns). This could cause incorrect "no match" results.
875
876 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
877 the pattern is reset in the first branch, pcre_compile() failed with
878 "internal error: code overflow at offset...". This happened only when
879 the reset was to the original external option setting. (An optimization
880 abstracts leading options settings into an external setting, which was the
881 cause of this.)
882
883 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
884 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
885 assertion pattern did not match (meaning that the assertion was true), it
886 was incorrectly treated as false if the SKIP had been reached during the
887 matching. This also applied to assertions used as conditions.
888
889 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
890 assertion subpattern, including such a pattern used as a condition,
891 unpredictable results occurred, instead of the error return
892 PCRE_ERROR_DFA_UITEM.
893
894 5. The C++ GlobalReplace function was not working like Perl for the special
895 situation when an empty string is matched. It now does the fancy magic
896 stuff that is necessary.
897
898 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
899 removed. (These were left over from very, very early versions of PCRE.)
900
901 7. Some cosmetic changes to the code to make life easier when compiling it
902 as part of something else:
903
904 (a) Change DEBUG to PCRE_DEBUG.
905
906 (b) In pcre_compile(), rename the member of the "branch_chain" structure
907 called "current" as "current_branch", to prevent a collision with the
908 Linux macro when compiled as a kernel module.
909
910 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
911 prevent a collision with the Linux macro when compiled as a kernel
912 module.
913
914 8. In pcre_compile() there are some checks for integer overflows that used to
915 cast potentially large values to (double). This has been changed to that
916 when building, a check for int64_t is made, and if it is found, it is used
917 instead, thus avoiding the use of floating point arithmetic. (There is no
918 other use of FP in PCRE.) If int64_t is not found, the fallback is to
919 double.
920
921 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
922 2005 (difference between two addresses compared to an unsigned value).
923
924 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
925 custom one, because of the following reported problem in Windows:
926
927 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
928 under Win32.
929 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
930 therefore missing the function definition.
931 - The compiler thus generates a "C" signature for the test function.
932 - The linker fails to find the "C" function.
933 - PCRE fails to configure if asked to do so against libbz2.
934
935 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
936 messages were output:
937
938 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
939 rerunning libtoolize, to keep the correct libtool macros in-tree.
940 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
941
942 I have done both of these things.
943
944 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
945 most of the time, it *can* run out if it is given a pattern that contains a
946 runaway infinite recursion. I updated the discussion in the pcrestack man
947 page.
948
949 13. Now that we have gone to the x.xx style of version numbers, the minor
950 version may start with zero. Using 08 or 09 is a bad idea because users
951 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
952 interpreted as invalid octal numbers. I've updated the previous comment in
953 configure.ac, and also added a check that gives an error if 08 or 09 are
954 used.
955
956 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
957 causing partial matching to fail when the end of the subject matched \W
958 in a UTF-8 pattern where \W was quantified with a minimum of 3.
959
960 15. There were some discrepancies between the declarations in pcre_internal.h
961 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
962 their definitions. The declarations used "const uschar *" and the
963 definitions used USPTR. Even though USPTR is normally defined as "const
964 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
965 reported that: "This difference in casting confuses some C++ compilers, for
966 example, SunCC recognizes above declarations as different functions and
967 generates broken code for hbpcre." I have changed the declarations to use
968 USPTR.
969
970 16. GNU libtool is named differently on some systems. The autogen.sh script now
971 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
972 (FreeBSD).
973
974 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
975 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
976 comment: "Figure out how to create a longlong from a string: strtoll and
977 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
978 instance, but it only takes 2 args instead of 3!"
979
980 18. A subtle bug concerned with back references has been fixed by a change of
981 specification, with a corresponding code fix. A pattern such as
982 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
983 refers, was giving matches when it shouldn't. For example, xa=xaaa would
984 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
985 same bug. Such groups have to be quantified to be useful, or contained
986 inside another quantified group. (If there's no repetition, the reference
987 can never match.) The problem arises because, having left the group and
988 moved on to the rest of the pattern, a later failure that backtracks into
989 the group uses the captured value from the final iteration of the group
990 rather than the correct earlier one. I have fixed this in PCRE by forcing
991 any group that contains a reference to itself to be an atomic group; that
992 is, there cannot be any backtracking into it once it has completed. This is
993 similar to recursive and subroutine calls.
994
995
996 Version 8.00 19-Oct-09
997 ----------------------
998
999 1. The table for translating pcre_compile() error codes into POSIX error codes
1000 was out-of-date, and there was no check on the pcre_compile() error code
1001 being within the table. This could lead to an OK return being given in
1002 error.
1003
1004 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
1005 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
1006 in a Windows environment.
1007
1008 3. The pcregrep --count option prints the count for each file even when it is
1009 zero, as does GNU grep. However, pcregrep was also printing all files when
1010 --files-with-matches was added. Now, when both options are given, it prints
1011 counts only for those files that have at least one match. (GNU grep just
1012 prints the file name in this circumstance, but including the count seems
1013 more useful - otherwise, why use --count?) Also ensured that the
1014 combination -clh just lists non-zero counts, with no names.
1015
1016 4. The long form of the pcregrep -F option was incorrectly implemented as
1017 --fixed_strings instead of --fixed-strings. This is an incompatible change,
1018 but it seems right to fix it, and I didn't think it was worth preserving
1019 the old behaviour.
1020
1021 5. The command line items --regex=pattern and --regexp=pattern were not
1022 recognized by pcregrep, which required --regex pattern or --regexp pattern
1023 (with a space rather than an '='). The man page documented the '=' forms,
1024 which are compatible with GNU grep; these now work.
1025
1026 6. No libpcreposix.pc file was created for pkg-config; there was just
1027 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
1028
1029 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
1030 when UCP support is not needed, by modifying the Python script that
1031 generates it from Unicode data files. This should not matter if the module
1032 is correctly used as a library, but I received one complaint about 50K of
1033 unwanted data. My guess is that the person linked everything into his
1034 program rather than using a library. Anyway, it does no harm.
1035
1036 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
1037 was a minimum greater than 1 for a wide character in a possessive
1038 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
1039 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
1040 character. Chaos in the form of incorrect output or a compiling loop could
1041 result.
1042
1043 9. The restrictions on what a pattern can contain when partial matching is
1044 requested for pcre_exec() have been removed. All patterns can now be
1045 partially matched by this function. In addition, if there are at least two
1046 slots in the offset vector, the offset of the earliest inspected character
1047 for the match and the offset of the end of the subject are set in them when
1048 PCRE_ERROR_PARTIAL is returned.
1049
1050 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
1051 synonymous with PCRE_PARTIAL, for backwards compatibility, and
1052 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
1053 and may be more useful for multi-segment matching.
1054
1055 11. Partial matching with pcre_exec() is now more intuitive. A partial match
1056 used to be given if ever the end of the subject was reached; now it is
1057 given only if matching could not proceed because another character was
1058 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
1059 string "Z", which now yields "no match" instead of "partial match". In the
1060 case of pcre_dfa_exec(), "no match" is given if every matching path for the
1061 final character ended with (*FAIL).
1062
1063 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
1064 if the pattern had a "must contain" character that was already found in the
1065 earlier partial match, unless partial matching was again requested. For
1066 example, with the pattern /dog.(body)?/, the "must contain" character is
1067 "g". If the first part-match was for the string "dog", restarting with
1068 "sbody" failed. This bug has been fixed.
1069
1070 13. The string returned by pcre_dfa_exec() after a partial match has been
1071 changed so that it starts at the first inspected character rather than the
1072 first character of the match. This makes a difference only if the pattern
1073 starts with a lookbehind assertion or \b or \B (\K is not supported by
1074 pcre_dfa_exec()). It's an incompatible change, but it makes the two
1075 matching functions compatible, and I think it's the right thing to do.
1076
1077 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
1078 so that the demonstration program is easily available in environments where
1079 PCRE has not been installed from source.
1080
1081 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
1082 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
1083 library.
1084
1085 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
1086 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
1087 is not the first non-POSIX option to be added. Clearly some people find
1088 these options useful.
1089
1090 17. If a caller to the POSIX matching function regexec() passes a non-zero
1091 value for nmatch with a NULL value for pmatch, the value of
1092 nmatch is forced to zero.
1093
1094 18. RunGrepTest did not have a test for the availability of the -u option of
1095 the diff command, as RunTest does. It now checks in the same way as
1096 RunTest, and also checks for the -b option.
1097
1098 19. If an odd number of negated classes containing just a single character
1099 interposed, within parentheses, between a forward reference to a named
1100 subpattern and the definition of the subpattern, compilation crashed with
1101 an internal error, complaining that it could not find the referenced
1102 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
1103 [The bug was that it was starting one character too far in when skipping
1104 over the character class, thus treating the ] as data rather than
1105 terminating the class. This meant it could skip too much.]
1106
1107 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
1108 /g option in pcretest when the pattern contains \K, which makes it possible
1109 to have an empty string match not at the start, even when the pattern is
1110 anchored. Updated pcretest and pcredemo to use this option.
1111
1112 21. If the maximum number of capturing subpatterns in a recursion was greater
1113 than the maximum at the outer level, the higher number was returned, but
1114 with unset values at the outer level. The correct (outer level) value is
1115 now given.
1116
1117 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
1118 PCRE did not set those parentheses (unlike Perl). I have now found a way to
1119 make it do so. The string so far is captured, making this feature
1120 compatible with Perl.
1121
1122 23. The tests have been re-organized, adding tests 11 and 12, to make it
1123 possible to check the Perl 5.10 features against Perl 5.10.
1124
1125 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
1126 pattern matches a fixed length string. PCRE did not allow this; now it
1127 does. Neither allows recursion.
1128
1129 25. I finally figured out how to implement a request to provide the minimum
1130 length of subject string that was needed in order to match a given pattern.
1131 (It was back references and recursion that I had previously got hung up
1132 on.) This code has now been added to pcre_study(); it finds a lower bound
1133 to the length of subject needed. It is not necessarily the greatest lower
1134 bound, but using it to avoid searching strings that are too short does give
1135 some useful speed-ups. The value is available to calling programs via
1136 pcre_fullinfo().
1137
1138 26. While implementing 25, I discovered to my embarrassment that pcretest had
1139 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
1140 study optimizations had never been tested with that matching function.
1141 Oops. What is worse, even when it was passed study data, there was a bug in
1142 pcre_dfa_exec() that meant it never actually used it. Double oops. There
1143 were also very few tests of studied patterns with pcre_dfa_exec().
1144
1145 27. If (?| is used to create subpatterns with duplicate numbers, they are now
1146 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
1147 on the other side of the coin, they are no longer allowed to have different
1148 names, because these cannot be distinguished in PCRE, and this has caused
1149 confusion. (This is a difference from Perl.)
1150
1151 28. When duplicate subpattern names are present (necessarily with different
1152 numbers, as required by 27 above), and a test is made by name in a
1153 conditional pattern, either for a subpattern having been matched, or for
1154 recursion in such a pattern, all the associated numbered subpatterns are
1155 tested, and the overall condition is true if the condition is true for any
1156 one of them. This is the way Perl works, and is also more like the way
1157 testing by number works.
1158
1159
1160 Version 7.9 11-Apr-09
1161 ---------------------
1162
1163 1. When building with support for bzlib/zlib (pcregrep) and/or readline
1164 (pcretest), all targets were linked against these libraries. This included
1165 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
1166 libraries. This caused unwanted dependencies to be created. This problem
1167 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
1168 pcretest is linked with readline.
1169
1170 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
1171 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
1172 moved outside it again, because FALSE and TRUE are already defined in AIX,
1173 but BOOL is not.
1174
1175 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
1176 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
1177
1178 4. The pcregrep documentation said spaces were inserted as well as colons (or
1179 hyphens) following file names and line numbers when outputting matching
1180 lines. This is not true; no spaces are inserted. I have also clarified the
1181 wording for the --colour (or --color) option.
1182
1183 5. In pcregrep, when --colour was used with -o, the list of matching strings
1184 was not coloured; this is different to GNU grep, so I have changed it to be
1185 the same.
1186
1187 6. When --colo(u)r was used in pcregrep, only the first matching substring in
1188 each matching line was coloured. Now it goes on to look for further matches
1189 of any of the test patterns, which is the same behaviour as GNU grep.
1190
1191 7. A pattern that could match an empty string could cause pcregrep to loop; it
1192 doesn't make sense to accept an empty string match in pcregrep, so I have
1193 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
1194 seems to be how GNU grep behaves.
1195
1196 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
1197 start or after a newline", because the conditional assertion was not being
1198 correctly handled. The rule now is that both the assertion and what follows
1199 in the first alternative must satisfy the test.
1200
1201 9. If auto-callout was enabled in a pattern with a conditional group whose
1202 condition was an assertion, PCRE could crash during matching, both with
1203 pcre_exec() and pcre_dfa_exec().
1204
1205 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
1206 used for matching.
1207
1208 11. Unicode property support in character classes was not working for
1209 characters (bytes) greater than 127 when not in UTF-8 mode.
1210
1211 12. Added the -M command line option to pcretest.
1212
1213 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
1214
1215 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
1216
1217 16. Added comments and documentation about mis-use of no_arg in the C++
1218 wrapper.
1219
1220 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
1221 from Martin Jerabek that uses macro names for all relevant character and
1222 string constants.
1223
1224 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
1225 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
1226 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
1227 these, but not everybody uses configure.
1228
1229 19. A conditional group that had only one branch was not being correctly
1230 recognized as an item that could match an empty string. This meant that an
1231 enclosing group might also not be so recognized, causing infinite looping
1232 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
1233 with the subject "ab", where knowledge that the repeated group can match
1234 nothing is needed in order to break the loop.
1235
1236 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
1237 exec(), but without supplying a callout function, matching went wrong.
1238
1239 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
1240 leak if the size of the offset vector was greater than 30. When the vector
1241 is smaller, the saved offsets during recursion go onto a local stack
1242 vector, but for larger vectors malloc() is used. It was failing to free
1243 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
1244 error, in fact).
1245
1246 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
1247 heapframe that is used only when UTF-8 support is enabled. This caused no
1248 problem, but was untidy.
1249
1250 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
1251 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
1252 included within another project.
1253
1254 24. Steven Van Ingelgem's patches to add more options to the CMake support,
1255 slightly modified by me:
1256
1257 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
1258 not building pcregrep.
1259
1260 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
1261 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
1262
1263 25. Forward references, both numeric and by name, in patterns that made use of
1264 duplicate group numbers, could behave incorrectly or give incorrect errors,
1265 because when scanning forward to find the reference group, PCRE was not
1266 taking into account the duplicate group numbers. A pattern such as
1267 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
1268
1269 26. Changed a few more instances of "const unsigned char *" to USPTR, making
1270 the feature of a custom pointer more persuasive (as requested by a user).
1271
1272 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
1273 pcretest.c, inside #ifndefs, because it seems they are sometimes already
1274 pre-defined.
1275
1276 28. Added support for (*UTF8) at the start of a pattern.
1277
1278 29. Arrange for flags added by the "release type" setting in CMake to be shown
1279 in the configuration summary.
1280
1281
1282 Version 7.8 05-Sep-08
1283 ---------------------
1284
1285 1. Replaced UCP searching code with optimized version as implemented for Ad
1286 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
1287 stage table and inline lookup instead of a function, giving speed ups of 2
1288 to 5 times on some simple patterns that I tested. Permission was given to
1289 distribute the MultiStage2.py script that generates the tables (it's not in
1290 the tarball, but is in the Subversion repository).
1291
1292 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
1293 scripts.
1294
1295 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
1296 a group with a zero qualifier. The result of the study could be incorrect,
1297 or the function might crash, depending on the pattern.
1298
1299 4. Caseless matching was not working for non-ASCII characters in back
1300 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
1301 It now works when Unicode Property Support is available.
1302
1303 5. In pcretest, an escape such as \x{de} in the data was always generating
1304 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
1305 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
1306 truncation.
1307
1308 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
1309
1310 7. Added two (int) casts to pcregrep when printing the difference of two
1311 pointers, in case they are 64-bit values.
1312
1313 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
1314 test 2 if it fails.
1315
1316 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
1317 and a #define of that name to empty if it is not externally set. This is to
1318 allow users of MSVC to set it if necessary.
1319
1320 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
1321 the convenience functions in the pcre_get.c source file.
1322
1323 11. An option change at the start of a pattern that had top-level alternatives
1324 could cause overwriting and/or a crash. This command provoked a crash in
1325 some environments:
1326
1327 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
1328
1329 This potential security problem was recorded as CVE-2008-2371.
1330
1331 12. For a pattern where the match had to start at the beginning or immediately
1332 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
1333 pcre_dfa_exec() could read past the end of the passed subject if there was
1334 no match. To help with detecting such bugs (e.g. with valgrind), I modified
1335 pcretest so that it places the subject at the end of its malloc-ed buffer.
1336
1337 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
1338 exec() might read past the end of the data buffer in UTF-8 mode.
1339
1340 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
1341 the data contained the byte 0x85 as part of a UTF-8 character within its
1342 first line. This applied both to normal and DFA matching.
1343
1344 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
1345 /^[^d]*?$/8 failed to match "abc".
1346
1347 16. Added a missing copyright notice to pcrecpp_internal.h.
1348
1349 17. Make it more clear in the documentation that values returned from
1350 pcre_exec() in ovector are byte offsets, not character counts.
1351
1352 18. Tidied a few places to stop certain compilers from issuing warnings.
1353
1354 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
1355 supplied by Stefan Weber. I made a further small update for 7.8 because
1356 there is a change of source arrangements: the pcre_searchfuncs.c module is
1357 replaced by pcre_ucd.c.
1358
1359
1360 Version 7.7 07-May-08
1361 ---------------------
1362
1363 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
1364 a string to a long long, pretend we don't even have a long long." This is
1365 done by checking for the strtoq, strtoll, and _strtoi64 functions.
1366
1367 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
1368 pre-7.6 versions, which defined a global no_arg variable instead of putting
1369 it in the RE class. (See also #8 below.)
1370
1371 3. Remove a line of dead code, identified by coverity and reported by Nuno
1372 Lopes.
1373
1374 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
1375
1376 (1) The include/exclude patterns were being applied to the whole pathnames
1377 of files, instead of just to the final components.
1378
1379 (2) If there was more than one level of directory, the subdirectories were
1380 skipped unless they satisfied the include/exclude conditions. This is
1381 inconsistent with GNU grep (and could even be seen as contrary to the
1382 pcregrep specification - which I improved to make it absolutely clear).
1383 The action now is always to scan all levels of directory, and just
1384 apply the include/exclude patterns to regular files.
1385
1386 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
1387 --exclude_dir in the tests to avoid scanning .svn directories.
1388
1389 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
1390 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
1391 doesn't support NULs in patterns.
1392
1393 7. Added some missing "const"s to declarations of static tables in
1394 pcre_compile.c and pcre_dfa_exec.c.
1395
1396 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
1397 caused by fix #2 above. (Subsequently also a second patch to fix the
1398 first patch. And a third patch - this was a messy problem.)
1399
1400 9. Applied Craig's patch to remove the use of push_back().
1401
1402 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
1403 matching function regexec().
1404
1405 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
1406 which, however, unlike Perl's \g{...}, are subroutine calls, not back
1407 references. PCRE supports relative numbers with this syntax (I don't think
1408 Oniguruma does).
1409
1410 12. Previously, a group with a zero repeat such as (...){0} was completely
1411 omitted from the compiled regex. However, this means that if the group
1412 was called as a subroutine from elsewhere in the pattern, things went wrong
1413 (an internal error was given). Such groups are now left in the compiled
1414 pattern, with a new opcode that causes them to be skipped at execution
1415 time.
1416
1417 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
1418 to the way PCRE behaves:
1419
1420 (a) A lone ] character is dis-allowed (Perl treats it as data).
1421
1422 (b) A back reference to an unmatched subpattern matches an empty string
1423 (Perl fails the current match path).
1424
1425 (c) A data ] in a character class must be notated as \] because if the
1426 first data character in a class is ], it defines an empty class. (In
1427 Perl it is not possible to have an empty class.) The empty class []
1428 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
1429 The negative empty class [^] matches any one character, independently
1430 of the DOTALL setting.
1431
1432 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
1433 non-existent subpattern following a character class starting with ']' and
1434 containing () gave an internal compiling error instead of "reference to
1435 non-existent subpattern". Fortunately, when the pattern did exist, the
1436 compiled code was correct. (When scanning forwards to check for the
1437 existencd of the subpattern, it was treating the data ']' as terminating
1438 the class, so got the count wrong. When actually compiling, the reference
1439 was subsequently set up correctly.)
1440
1441 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
1442 it was being rejected as not supported by pcre_dfa_exec(), even though
1443 other assertions are supported. I have made pcre_dfa_exec() support
1444 (*FAIL).
1445
1446 16. The implementation of 13c above involved the invention of a new opcode,
1447 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
1448 cannot be changed at match time, I realized I could make a small
1449 improvement to matching performance by compiling OP_ALLANY instead of
1450 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
1451 on the OP_ANY path.
1452
1453 17. Compiling pcretest on Windows with readline support failed without the
1454 following two fixes: (1) Make the unistd.h include conditional on
1455 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
1456
1457 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
1458 ncurses library to be included for pcretest when ReadLine support is
1459 requested, but also to allow for it to be overridden. This patch came from
1460 Daniel Bergström.
1461
1462 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
1463 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
1464 any errors with the current Unicode tables. Thanks to Peter Kankowski for
1465 spotting this.
1466
1467
1468 Version 7.6 28-Jan-08
1469 ---------------------
1470
1471 1. A character class containing a very large number of characters with
1472 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
1473 overflow.
1474
1475 2. Patch to cut out the "long long" test in pcrecpp_unittest when
1476 HAVE_LONG_LONG is not defined.
1477
1478 3. Applied Christian Ehrlicher's patch to update the CMake build files to
1479 bring them up to date and include new features. This patch includes:
1480
1481 - Fixed PH's badly added libz and libbz2 support.
1482 - Fixed a problem with static linking.
1483 - Added pcredemo. [But later removed - see 7 below.]
1484 - Fixed dftables problem and added an option.
1485 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
1486 HAVE_LONG_LONG.
1487 - Added readline support for pcretest.
1488 - Added an listing of the option settings after cmake has run.
1489
1490 4. A user submitted a patch to Makefile that makes it easy to create
1491 "pcre.dll" under mingw when using Configure/Make. I added stuff to
1492 Makefile.am that cause it to include this special target, without
1493 affecting anything else. Note that the same mingw target plus all
1494 the other distribution libraries and programs are now supported
1495 when configuring with CMake (see 6 below) instead of with
1496 Configure/Make.
1497
1498 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
1499 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
1500 exported in the Windows port". It has not yet been confirmed that the patch
1501 solves the problem, but it does no harm.
1502
1503 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
1504 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
1505 with CMake, and also correct the comment about stack recursion.
1506
1507 7. Remove the automatic building of pcredemo from the ./configure system and
1508 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
1509 of a program that users should build themselves after PCRE is installed, so
1510 building it automatically is not really right. What is more, it gave
1511 trouble in some build environments.
1512
1513 8. Further tidies to CMakeLists.txt from Sheri and Christian.
1514
1515
1516 Version 7.5 10-Jan-08
1517 ---------------------
1518
1519 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
1520 values in parens when parsing an RE using the C++ wrapper."
1521
1522 2. Negative specials like \S did not work in character classes in UTF-8 mode.
1523 Characters greater than 255 were excluded from the class instead of being
1524 included.
1525
1526 3. The same bug as (2) above applied to negated POSIX classes such as
1527 [:^space:].
1528
1529 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
1530 defined or documented. It seems to have been a typo for PCRE_STATIC, so
1531 I have changed it.
1532
1533 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
1534 first named subpattern) and a construct such as (?&a) would reference the
1535 first named subpattern whose name started with "a" (in other words, the
1536 length check was missing). Both these problems are fixed. "Subpattern name
1537 expected" is now given for (?&) (a zero-length name), and this patch also
1538 makes it give the same error for \k'' (previously it complained that that
1539 was a reference to a non-existent subpattern).
1540
1541 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
1542 this is right because (?- can be followed by option settings as well as by
1543 digits. I have, however, made the messages clearer.
1544
1545 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
1546 than the number used in the conditional) now cause a compile-time error.
1547 This is actually not compatible with Perl, which accepts such patterns, but
1548 treats the conditional as always being FALSE (as PCRE used to), but it
1549 seems to me that giving a diagnostic is better.
1550
1551 8. Change "alphameric" to the more common word "alphanumeric" in comments
1552 and messages.
1553
1554 9. Fix two occurrences of "backslash" in comments that should have been
1555 "backspace".
1556
1557 10. Remove two redundant lines of code that can never be obeyed (their function
1558 was moved elsewhere).
1559
1560 11. The program that makes PCRE's Unicode character property table had a bug
1561 which caused it to generate incorrect table entries for sequences of
1562 characters that have the same character type, but are in different scripts.
1563 It amalgamated them into a single range, with the script of the first of
1564 them. In other words, some characters were in the wrong script. There were
1565 thirteen such cases, affecting characters in the following ranges:
1566
1567 U+002b0 - U+002c1
1568 U+0060c - U+0060d
1569 U+0061e - U+00612
1570 U+0064b - U+0065e
1571 U+0074d - U+0076d
1572 U+01800 - U+01805
1573 U+01d00 - U+01d77
1574 U+01d9b - U+01dbf
1575 U+0200b - U+0200f
1576 U+030fc - U+030fe
1577 U+03260 - U+0327f
1578 U+0fb46 - U+0fbb1
1579 U+10450 - U+1049d
1580
1581 12. The -o option (show only the matching part of a line) for pcregrep was not
1582 compatible with GNU grep in that, if there was more than one match in a
1583 line, it showed only the first of them. It now behaves in the same way as
1584 GNU grep.
1585
1586 13. If the -o and -v options were combined for pcregrep, it printed a blank
1587 line for every non-matching line. GNU grep prints nothing, and pcregrep now
1588 does the same. The return code can be used to tell if there were any
1589 non-matching lines.
1590
1591 14. Added --file-offsets and --line-offsets to pcregrep.
1592
1593 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
1594 infinitely looping recursion. The bug was that positive lookaheads were not
1595 being skipped when checking for a possible empty match (negative lookaheads
1596 and both kinds of lookbehind were skipped).
1597
1598 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
1599 inclusion of <windows.h> to before rather than after the definition of
1600 INVALID_FILE_ATTRIBUTES (patch from David Byron).
1601
1602 17. Specifying a possessive quantifier with a specific limit for a Unicode
1603 character property caused pcre_compile() to compile bad code, which led at
1604 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
1605 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
1606 caused the error; without that there was no problem.
1607
1608 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
1609
1610 19. Added --enable-pcretest-libreadline.
1611
1612 20. In pcrecpp.cc, the variable 'count' was incremented twice in
1613 RE::GlobalReplace(). As a result, the number of replacements returned was
1614 double what it should be. I removed one of the increments, but Craig sent a
1615 later patch that removed the other one (the right fix) and added unit tests
1616 that check the return values (which was not done before).
1617
1618 21. Several CMake things:
1619
1620 (1) Arranged that, when cmake is used on Unix, the libraries end up with
1621 the names libpcre and libpcreposix, not just pcre and pcreposix.
1622
1623 (2) The above change means that pcretest and pcregrep are now correctly
1624 linked with the newly-built libraries, not previously installed ones.
1625
1626 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
1627
1628 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
1629 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
1630 UTF-8 newline character). The key issue is that the pattern starts .*;
1631 this means that the match must be either at the beginning, or after a
1632 newline. The bug was in the code for advancing after a failed match and
1633 checking that the new position followed a newline. It was not taking
1634 account of UTF-8 characters correctly.
1635
1636 23. PCRE was behaving differently from Perl in the way it recognized POSIX
1637 character classes. PCRE was not treating the sequence [:...:] as a
1638 character class unless the ... were all letters. Perl, however, seems to
1639 allow any characters between [: and :], though of course it rejects as
1640 unknown any "names" that contain non-letters, because all the known class
1641 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
1642 for example, whereas PCRE did not - it did not recognize a POSIX character
1643 class. This seemed a bit dangerous, so the code has been changed to be
1644 closer to Perl. The behaviour is not identical to Perl, because PCRE will
1645 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
1646 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
1647 Perl does, and where it didn't before.
1648
1649 24. Rewrite so as to remove the single use of %n from pcregrep because in some
1650 Windows environments %n is disabled by default.
1651
1652
1653 Version 7.4 21-Sep-07
1654 ---------------------
1655
1656 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
1657 means that a class such as [\s] counted as "explicit reference to CR or
1658 LF". That isn't really right - the whole point of the change was to try to
1659 help when there was an actual mention of one of the two characters. So now
1660 the change happens only if \r or \n (or a literal CR or LF) character is
1661 encountered.
1662
1663 2. The 32-bit options word was also used for 6 internal flags, but the numbers
1664 of both had grown to the point where there were only 3 bits left.
1665 Fortunately, there was spare space in the data structure, and so I have
1666 moved the internal flags into a new 16-bit field to free up more option
1667 bits.
1668
1669 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
1670 but did not set the internal JCHANGED flag - either of these is enough to
1671 control the way the "get" function works - but the PCRE_INFO_JCHANGED
1672 facility is supposed to tell if (?J) was ever used, so now (?J) at the
1673 start sets both bits.
1674
1675 4. Added options (at build time, compile time, exec time) to change \R from
1676 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
1677
1678 5. doc/pcresyntax.html was missing from the distribution.
1679
1680 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
1681 compatibility, even though it is no longer used.
1682
1683 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
1684 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
1685 windows.h file is present (where different names are used). [This was
1686 reversed later after testing - see 16 below.]
1687
1688 8. Changed all #include <config.h> to #include "config.h". There were also
1689 some further <pcre.h> cases that I changed to "pcre.h".
1690
1691 9. When pcregrep was used with the --colour option, it missed the line ending
1692 sequence off the lines that it output.
1693
1694 10. It was pointed out to me that arrays of string pointers cause lots of
1695 relocations when a shared library is dynamically loaded. A technique of
1696 using a single long string with a table of offsets can drastically reduce
1697 these. I have refactored PCRE in four places to do this. The result is
1698 dramatic:
1699
1700 Originally: 290
1701 After changing UCP table: 187
1702 After changing error message table: 43
1703 After changing table of "verbs" 36
1704 After changing table of Posix names 22
1705
1706 Thanks to the folks working on Gregex for glib for this insight.
1707
1708 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
1709 unicode-properties was also set.
1710
1711 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
1712
1713 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
1714 checked only for CRLF.
1715
1716 14. Added casts to pcretest.c to avoid compiler warnings.
1717
1718 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
1719
1720 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
1721 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
1722 entirely. This removes changes made in 7 above.
1723
1724 17. The CMake files have been updated, and there is now more information about
1725 building with CMake in the NON-UNIX-USE document.
1726
1727
1728 Version 7.3 28-Aug-07
1729 ---------------------
1730
1731 1. In the rejigging of the build system that eventually resulted in 7.1, the
1732 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
1733 brackets there is not right, since it causes compilers to look for an
1734 installed pcre.h, not the version that is in the source that is being
1735 compiled (which of course may be different). I have changed it back to:
1736
1737 #include "pcre.h"
1738
1739 I have a vague recollection that the change was concerned with compiling in
1740 different directories, but in the new build system, that is taken care of
1741 by the VPATH setting the Makefile.
1742
1743 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
1744 when the subject happened to end in the byte 0x85 (e.g. if the last
1745 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
1746 characters but of course it shouldn't be taken as a newline when it is part
1747 of another character. The bug was that, for an unlimited repeat of . in
1748 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
1749 characters when looking for a newline.
1750
1751 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
1752
1753 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
1754 in debug output.
1755
1756 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
1757 long printing in the pcrecpp unittest when running under MinGW.
1758
1759 6. ESC_K was left out of the EBCDIC table.
1760
1761 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
1762 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
1763 limit also applies to "virtual nesting" when a pattern is recursive, and in
1764 this case 1000 isn't so big. I have been able to remove this limit at the
1765 expense of backing off one optimization in certain circumstances. Normally,
1766 when pcre_exec() would call its internal match() function recursively and
1767 immediately return the result unconditionally, it uses a "tail recursion"
1768 feature to save stack. However, when a subpattern that can match an empty
1769 string has an unlimited repetition quantifier, it no longer makes this
1770 optimization. That gives it a stack frame in which to save the data for
1771 checking that an empty string has been matched. Previously this was taken
1772 from the 1000-entry workspace that had been reserved. So now there is no
1773 explicit limit, but more stack is used.
1774
1775 8. Applied Daniel's patches to solve problems with the import/export magic
1776 syntax that is required for Windows, and which was going wrong for the
1777 pcreposix and pcrecpp parts of the library. These were overlooked when this
1778 problem was solved for the main library.
1779
1780 9. There were some crude static tests to avoid integer overflow when computing
1781 the size of patterns that contain repeated groups with explicit upper
1782 limits. As the maximum quantifier is 65535, the maximum group length was
1783 set at 30,000 so that the product of these two numbers did not overflow a
1784 32-bit integer. However, it turns out that people want to use groups that
1785 are longer than 30,000 bytes (though not repeat them that many times).
1786 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
1787 made it possible to implement the integer overflow checks in a much more
1788 dynamic way, which I have now done. The artificial limitation on group
1789 length has been removed - we now have only the limit on the total length of
1790 the compiled pattern, which depends on the LINK_SIZE setting.
1791
1792 10. Fixed a bug in the documentation for get/copy named substring when
1793 duplicate names are permitted. If none of the named substrings are set, the
1794 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
1795 empty string.
1796
1797 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
1798 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
1799 because the ] is interpreted as the first data character and the
1800 terminating ] is not found. PCRE has been made compatible with Perl in this
1801 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
1802 cause memory overwriting.
1803
1804 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
1805 string has been matched (to stop an infinite loop). It was not recognizing
1806 a conditional subpattern that could match an empty string if that
1807 subpattern was within another subpattern. For example, it looped when
1808 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
1809 condition was not nested. This bug has been fixed.
1810
1811 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
1812 past the start of the subject in the presence of bytes with the top bit
1813 set, for example "\x8aBCD".
1814
1815 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
1816 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
1817
1818 14. Optimized (?!) to (*FAIL).
1819
1820 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
1821 This restricts code points to be within the range 0 to 0x10FFFF, excluding
1822 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
1823 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
1824 does: it's just the validity check that is more restrictive.
1825
1826 16. Inserted checks for integer overflows during escape sequence (backslash)
1827 processing, and also fixed erroneous offset values for syntax errors during
1828 backslash processing.
1829
1830 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
1831 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
1832
1833 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
1834 caused an overrun.
1835
1836 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
1837 something other than just ASCII characters) inside a group that had an
1838 unlimited repeat caused a loop at compile time (while checking to see
1839 whether the group could match an empty string).
1840
1841 20. Debugging a pattern containing \p or \P could cause a crash. For example,
1842 [\P{Any}] did so. (Error in the code for printing property names.)
1843
1844 21. An orphan \E inside a character class could cause a crash.
1845
1846 22. A repeated capturing bracket such as (A)? could cause a wild memory
1847 reference during compilation.
1848
1849 23. There are several functions in pcre_compile() that scan along a compiled
1850 expression for various reasons (e.g. to see if it's fixed length for look
1851 behind). There were bugs in these functions when a repeated \p or \P was
1852 present in the pattern. These operators have additional parameters compared
1853 with \d, etc, and these were not being taken into account when moving along
1854 the compiled data. Specifically:
1855
1856 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
1857 length.
1858
1859 (b) An item such as \pL+ within a repeated group could cause crashes or
1860 loops.
1861
1862 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
1863 "reference to non-existent subpattern" error.
1864
1865 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
1866
1867 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
1868 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
1869
1870 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
1871
1872 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
1873 character were causing crashes (broken optimization).
1874
1875 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
1876 \p or \P) caused a compile-time loop.
1877
1878 28. More problems have arisen in unanchored patterns when CRLF is a valid line
1879 break. For example, the unstudied pattern [\r\n]A does not match the string
1880 "\r\nA" because change 7.0/46 below moves the current point on by two
1881 characters after failing to match at the start. However, the pattern \nA
1882 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
1883 the same is true. There doesn't seem any very clean way out of this, but
1884 what I have chosen to do makes the common cases work: PCRE now takes note
1885 of whether there can be an explicit match for \r or \n anywhere in the
1886 pattern, and if so, 7.0/46 no longer applies. As part of this change,
1887 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
1888 pattern has explicit CR or LF references.
1889
1890 29. Added (*CR) etc for changing newline setting at start of pattern.
1891
1892
1893 Version 7.2 19-Jun-07
1894 ---------------------
1895
1896 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
1897 which is apparently normally available under Windows.
1898
1899 2. Re-jig the pcregrep tests with different newline settings in an attempt
1900 to make them independent of the local environment's newline setting.
1901
1902 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
1903
1904 4. Some of the "internals" tests were previously cut out when the link size
1905 was not 2, because the output contained actual offsets. The recent new
1906 "Z" feature of pcretest means that these can be cut out, making the tests
1907 usable with all link sizes.
1908
1909 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
1910 stack recursion. This gives a massive performance boost under BSD, but just
1911 a small improvement under Linux. However, it saves one field in the frame
1912 in all cases.
1913
1914 6. Added more features from the forthcoming Perl 5.10:
1915
1916 (a) (?-n) (where n is a string of digits) is a relative subroutine or
1917 recursion call. It refers to the nth most recently opened parentheses.
1918
1919 (b) (?+n) is also a relative subroutine call; it refers to the nth next
1920 to be opened parentheses.
1921
1922 (c) Conditions that refer to capturing parentheses can be specified
1923 relatively, for example, (?(-2)... or (?(+3)...
1924
1925 (d) \K resets the start of the current match so that everything before
1926 is not part of it.
1927
1928 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
1929
1930 (f) \g{name} is another synonym - part of Perl 5.10's unification of
1931 reference syntax.
1932
1933 (g) (?| introduces a group in which the numbering of parentheses in each
1934 alternative starts with the same number.
1935
1936 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
1937
1938 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
1939 PCRE_INFO_JCHANGED.
1940
1941 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
1942 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
1943 for detecting groups that can match an empty string.
1944
1945 9. A pattern with a very large number of alternatives (more than several
1946 hundred) was running out of internal workspace during the pre-compile
1947 phase, where pcre_compile() figures out how much memory will be needed. A
1948 bit of new cunning has reduced the workspace needed for groups with
1949 alternatives. The 1000-alternative test pattern now uses 12 bytes of
1950 workspace instead of running out of the 4096 that are available.
1951
1952 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
1953
1954 11. Applied patch from Google to remove an optimization that didn't quite work.
1955 The report of the bug said:
1956
1957 pcrecpp::RE("a*").FullMatch("aaa") matches, while
1958 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
1959 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
1960
1961 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
1962 it matched the wrong number of bytes.
1963
1964
1965 Version 7.1 24-Apr-07
1966 ---------------------
1967
1968 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
1969 that is more "standard", making use of automake and other Autotools. There
1970 is some re-arrangement of the files and adjustment of comments consequent
1971 on this.
1972
1973 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
1974 for recursive directory scanning broke on some systems because the files
1975 are not scanned in any specific order and on different systems the order
1976 was different. A call to "sort" has been inserted into RunGrepTest for the
1977 approprate test as a short-term fix. In the longer term there may be an
1978 alternative.
1979
1980 3. I had an email from Eric Raymond about problems translating some of PCRE's
1981 man pages to HTML (despite the fact that I distribute HTML pages, some
1982 people do their own conversions for various reasons). The problems
1983 concerned the use of low-level troff macros .br and .in. I have therefore
1984 removed all such uses from the man pages (some were redundant, some could
1985 be replaced by .nf/.fi pairs). The 132html script that I use to generate
1986 HTML has been updated to handle .nf/.fi and to complain if it encounters
1987 .br or .in.
1988
1989 4. Updated comments in configure.ac that get placed in config.h.in and also
1990 arranged for config.h to be included in the distribution, with the name
1991 config.h.generic, for the benefit of those who have to compile without
1992 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
1993
1994 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
1995 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
1996 makevp.bat for the current PCRE, using the additional files
1997 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
1998
1999 6. A Windows user reported a minor discrepancy with test 2, which turned out
2000 to be caused by a trailing space on an input line that had got lost in his
2001 copy. The trailing space was an accident, so I've just removed it.
2002
2003 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
2004 that is needed.
2005
2006 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
2007 as "const" (a) because they are and (b) because it helps the PHP
2008 maintainers who have recently made a script to detect big data structures
2009 in the php code that should be moved to the .rodata section. I remembered
2010 to update Builducptable as well, so it won't revert if ucptable.h is ever
2011 re-created.
2012
2013 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
2014 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
2015 order to be able to cut out the UTF-8 tables in the latter when UTF-8
2016 support is not required. This saves 1.5-2K of code, which is important in
2017 some applications.
2018
2019 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
2020 so as not to refer to the tables, even though these functions will never be
2021 called when UTF-8 support is disabled. Otherwise there are problems with a
2022 shared library.
2023
2024 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
2025
2026 (a) It was defining its arguments as char * instead of void *.
2027
2028 (b) It was assuming that all moves were upwards in memory; this was true
2029 a long time ago when I wrote it, but is no longer the case.
2030
2031 The emulated memove() is provided for those environments that have neither
2032 memmove() nor bcopy(). I didn't think anyone used it these days, but that
2033 is clearly not the case, as these two bugs were recently reported.
2034
2035 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
2036 and Detrail to create the HTML documentation, the .txt form of the man
2037 pages, and it removes trailing spaces from listed files. It also creates
2038 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
2039 case, it wraps all the #defines with #ifndefs. This script should be run
2040 before "make dist".
2041
2042 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
2043 with Unicode property support.
2044
2045 (a) For a maximizing quantifier, if the two different cases of the
2046 character were of different lengths in their UTF-8 codings (there are
2047 some cases like this - I found 11), and the matching function had to
2048 back up over a mixture of the two cases, it incorrectly assumed they
2049 were both the same length.
2050
2051 (b) When PCRE was configured to use the heap rather than the stack for
2052 recursion during matching, it was not correctly preserving the data for
2053 the other case of a UTF-8 character when checking ahead for a match
2054 while processing a minimizing repeat. If the check also involved
2055 matching a wide character, but failed, corruption could cause an
2056 erroneous result when trying to check for a repeat of the original
2057 character.
2058
2059 13. Some tidying changes to the testing mechanism:
2060
2061 (a) The RunTest script now detects the internal link size and whether there
2062 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
2063 values substituted by "configure". (The RunGrepTest script already did
2064 this for UTF-8.) The configure.ac script no longer substitutes the
2065 relevant variables.
2066
2067 (b) The debugging options /B and /D in pcretest show the compiled bytecode
2068 with length and offset values. This means that the output is different
2069 for different internal link sizes. Test 2 is skipped for link sizes
2070 other than 2 because of this, bypassing the problem. Unfortunately,
2071 there was also a test in test 3 (the locale tests) that used /B and
2072 failed for link sizes other than 2. Rather than cut the whole test out,
2073 I have added a new /Z option to pcretest that replaces the length and
2074 offset values with spaces. This is now used to make test 3 independent
2075 of link size. (Test 2 will be tidied up later.)
2076
2077 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
2078 segmentation fault instead of returning the appropriate error message.
2079
2080 15. In multiline mode when the newline sequence was set to "any", the pattern
2081 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
2082 This doesn't seem right; it now treats the CRLF combination as the line
2083 ending, and so does not match in that case. It's only a pattern such as ^$
2084 that would hit this one: something like ^ABC$ would have failed after \r
2085 and then tried again after \r\n.
2086
2087 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
2088 in an attempt to make files that differ only in their line terminators
2089 compare equal. This works on Linux.
2090
2091 17. Under certain error circumstances pcregrep might try to free random memory
2092 as it exited. This is now fixed, thanks to valgrind.
2093
2094 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
2095 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
2096 was because its rules for how to advance for /g after matching an empty
2097 string at the end of a line did not allow for this case. They now check for
2098 it specially.
2099
2100 20. pcretest is supposed to handle patterns and data of any length, by
2101 extending its buffers when necessary. It was getting this wrong when the
2102 buffer for a data line had to be extended.
2103
2104 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
2105 CRLF as a newline sequence.
2106
2107 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
2108 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
2109 I have nevertheless tidied it up.
2110
2111 23. Added some casts to kill warnings from HP-UX ia64 compiler.
2112
2113 24. Added a man page for pcre-config.
2114
2115
2116 Version 7.0 19-Dec-06
2117 ---------------------
2118
2119 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
2120 moving to gcc 4.1.1.
2121
2122 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
2123 sys/time.h, which is documented as needed for this function. It doesn't
2124 seem to matter on Linux, but it showed up on some releases of OS X.
2125
2126 3. It seems that there are systems where bytes whose values are greater than
2127 127 match isprint() in the "C" locale. The "C" locale should be the
2128 default when a C program starts up. In most systems, only ASCII printing
2129 characters match isprint(). This difference caused the output from pcretest
2130 to vary, making some of the tests fail. I have changed pcretest so that:
2131
2132 (a) When it is outputting text in the compiled version of a pattern, bytes
2133 other than 32-126 are always shown as hex escapes.
2134
2135 (b) When it is outputting text that is a matched part of a subject string,
2136 it does the same, unless a different locale has been set for the match
2137 (using the /L modifier). In this case, it uses isprint() to decide.
2138
2139 4. Fixed a major bug that caused incorrect computation of the amount of memory
2140 required for a compiled pattern when options that changed within the
2141 pattern affected the logic of the preliminary scan that determines the
2142 length. The relevant options are -x, and -i in UTF-8 mode. The result was
2143 that the computed length was too small. The symptoms of this bug were
2144 either the PCRE error "internal error: code overflow" from pcre_compile(),
2145 or a glibc crash with a message such as "pcretest: free(): invalid next
2146 size (fast)". Examples of patterns that provoked this bug (shown in
2147 pcretest format) are:
2148
2149 /(?-x: )/x
2150 /(?x)(?-x: \s*#\s*)/
2151 /((?i)[\x{c0}])/8
2152 /(?i:[\x{c0}])/8
2153
2154 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
2155 is now done differently.
2156
2157 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
2158 wrapper classes; (b) implement a new function in the C++ scanner that is
2159 more efficient than the old way of doing things because it avoids levels of
2160 recursion in the regex matching; (c) add a paragraph to the documentation
2161 for the FullMatch() function.
2162
2163 6. The escape sequence \n was being treated as whatever was defined as
2164 "newline". Not only was this contrary to the documentation, which states
2165 that \n is character 10 (hex 0A), but it also went horribly wrong when
2166 "newline" was defined as CRLF. This has been fixed.
2167
2168 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
2169 was being set to -1 for the "end of line" case (supposedly a value that no
2170 character can have). Though this value is never used (the check for end of
2171 line is "zero bytes in current character"), it caused compiler complaints.
2172 I've changed it to 0xffffffff.
2173
2174 8. In pcre_version.c, the version string was being built by a sequence of
2175 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
2176 string (as it is for production releases) called a macro with an empty
2177 argument. The C standard says the result of this is undefined. The gcc
2178 compiler treats it as an empty string (which was what was wanted) but it is
2179 reported that Visual C gives an error. The source has been hacked around to
2180 avoid this problem.
2181
2182 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
2183 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
2184 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
2185 of them did).
2186
2187 10. Originally, pcretest opened its input and output without "b"; then I was
2188 told that "b" was needed in some environments, so it was added for release
2189 5.0 to both the input and output. (It makes no difference on Unix-like
2190 systems.) Later I was told that it is wrong for the input on Windows. I've
2191 now abstracted the modes into two macros, to make it easier to fiddle with
2192 them, and removed "b" from the input mode under Windows.
2193
2194 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
2195
2196 12. Added -help and --help to pcretest as an official way of being reminded
2197 of the options.
2198
2199 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
2200 and pcrecpp.cc because they annoy compilers at high warning levels.
2201
2202 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
2203
2204 15. Fixed an occurrence of == in configure.ac that should have been = (shell
2205 scripts are not C programs :-) and which was not noticed because it works
2206 on Linux.
2207
2208 16. pcretest is supposed to handle any length of pattern and data line (as one
2209 line or as a continued sequence of lines) by extending its input buffer if
2210 necessary. This feature was broken for very long pattern lines, leading to
2211 a string of junk being passed to pcre_compile() if the pattern was longer
2212 than about 50K.
2213
2214 17. I have done a major re-factoring of the way pcre_compile() computes the
2215 amount of memory needed for a compiled pattern. Previously, there was code
2216 that made a preliminary scan of the pattern in order to do this. That was
2217 OK when PCRE was new, but as the facilities have expanded, it has become
2218 harder and harder to keep it in step with the real compile phase, and there
2219 have been a number of bugs (see for example, 4 above). I have now found a
2220 cunning way of running the real compile function in a "fake" mode that
2221 enables it to compute how much memory it would need, while actually only
2222 ever using a few hundred bytes of working memory and without too many
2223 tests of the mode. This should make future maintenance and development
2224 easier. A side effect of this work is that the limit of 200 on the nesting
2225 depth of parentheses has been removed (though this was never a serious
2226 limitation, I suspect). However, there is a downside: pcre_compile() now
2227 runs more slowly than before (30% or more, depending on the pattern). I
2228 hope this isn't a big issue. There is no effect on runtime performance.
2229
2230 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
2231 newline (only possible for the last line of a file) and it was a
2232 pattern that set a locale (followed by /Lsomething), pcretest crashed.
2233
2234 19. Added additional timing features to pcretest. (1) The -tm option now times
2235 matching only, not compiling. (2) Both -t and -tm can be followed, as a
2236 separate command line item, by a number that specifies the number of
2237 repeats to use when timing. The default is 50000; this gives better
2238 precision, but takes uncomfortably long for very large patterns.
2239
2240 20. Extended pcre_study() to be more clever in cases where a branch of a
2241 subpattern has no definite first character. For example, (a*|b*)[cd] would
2242 previously give no result from pcre_study(). Now it recognizes that the
2243 first character must be a, b, c, or d.
2244
2245 21. There was an incorrect error "recursive call could loop indefinitely" if
2246 a subpattern (or the entire pattern) that was being tested for matching an
2247 empty string contained only one non-empty item after a nested subpattern.
2248 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
2249 incorrectly, because the \d was being skipped in the check.
2250
2251 22. The pcretest program now has a new pattern option /B and a command line
2252 option -b, which is equivalent to adding /B to every pattern. This causes
2253 it to show the compiled bytecode, without the additional information that
2254 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
2255 is the same as /B/I).
2256
2257 23. A new optimization is now able automatically to treat some sequences such
2258 as a*b as a*+b. More specifically, if something simple (such as a character
2259 or a simple class like \d) has an unlimited quantifier, and is followed by
2260 something that cannot possibly match the quantified thing, the quantifier
2261 is automatically "possessified".
2262
2263 24. A recursive reference to a subpattern whose number was greater than 39
2264 went wrong under certain circumstances in UTF-8 mode. This bug could also
2265 have affected the operation of pcre_study().
2266
2267 25. Realized that a little bit of performance could be had by replacing
2268 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
2269
2270 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
2271
2272 27. Possessive quantifiers such as a++ were previously implemented by turning
2273 them into atomic groups such as ($>a+). Now they have their own opcodes,
2274 which improves performance. This includes the automatically created ones
2275 from 23 above.
2276
2277 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
2278 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
2279 the first matched character to be a colon. This applied both to named and
2280 numbered groups.
2281
2282 29. The ucpinternal.h header file was missing its idempotency #ifdef.
2283
2284 30. I was sent a "project" file called libpcre.a.dev which I understand makes
2285 building PCRE on Windows easier, so I have included it in the distribution.
2286
2287 31. There is now a check in pcretest against a ridiculously large number being
2288 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
2289 loop, the loop is abandoned.
2290
2291 32. Forward references to subpatterns in conditions such as (?(2)...) where
2292 subpattern 2 is defined later cause pcre_compile() to search forwards in
2293 the pattern for the relevant set of parentheses. This search went wrong
2294 when there were unescaped parentheses in a character class, parentheses
2295 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
2296
2297 33. "Subroutine" calls and backreferences were previously restricted to
2298 referencing subpatterns earlier in the regex. This restriction has now
2299 been removed.
2300
2301 34. Added a number of extra features that are going to be in Perl 5.10. On the
2302 whole, these are just syntactic alternatives for features that PCRE had
2303 previously implemented using the Python syntax or my own invention. The
2304 other formats are all retained for compatibility.
2305
2306 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
2307 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
2308 also .NET compatible.
2309
2310 (b) A recursion or subroutine call to a named group can now be defined as
2311 (?&name) as well as (?P>name).
2312
2313 (c) A backreference to a named group can now be defined as \k<name> or
2314 \k'name' as well as (?P=name). The new forms, as well as being in Perl
2315 5.10, are also .NET compatible.
2316
2317 (d) A conditional reference to a named group can now use the syntax
2318 (?(<name>) or (?('name') as well as (?(name).
2319
2320 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
2321 groups (named and numbered) that are never evaluated inline, but can be
2322 called as "subroutines" from elsewhere. In effect, the DEFINE condition
2323 is always false. There may be only one alternative in such a group.
2324
2325 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
2326 as the simple (?(R). The condition is true only if the most recent
2327 recursion is that of the given number or name. It does not search out
2328 through the entire recursion stack.
2329
2330 (g) The escape \gN or \g{N} has been added, where N is a positive or
2331 negative number, specifying an absolute or relative reference.
2332
2333 35. Tidied to get rid of some further signed/unsigned compiler warnings and
2334 some "unreachable code" warnings.
2335
2336 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
2337 things, this adds five new scripts.
2338
2339 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
2340 There were also incompatibilities regarding the handling of \Q..\E inside
2341 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
2342 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
2343
2344 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
2345 matches an empty string, and forcibly breaks the loop. There were bugs in
2346 this code in non-simple cases. For a pattern such as ^(a()*)* matched
2347 against aaaa the result was just "a" rather than "aaaa", for example. Two
2348 separate and independent bugs (that affected different cases) have been
2349 fixed.
2350
2351 39. Refactored the code to abolish the use of different opcodes for small
2352 capturing bracket numbers. This is a tidy that I avoided doing when I
2353 removed the limit on the number of capturing brackets for 3.5 back in 2001.
2354 The new approach is not only tidier, it makes it possible to reduce the
2355 memory needed to fix the previous bug (38).
2356
2357 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
2358 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
2359 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
2360 mode.
2361
2362 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
2363 report.
2364
2365 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
2366 copy construction and assignment in the C++ wrapper.
2367
2368 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
2369 couple of bugs that could have given wrong results in the "--newline=crlf"
2370 case.
2371
2372 44. Added a number of casts and did some reorganization of signed/unsigned int
2373 variables following suggestions from Dair Grant. Also renamed the variable
2374 "this" as "item" because it is a C++ keyword.
2375
2376 45. Arranged for dftables to add
2377
2378 #include "pcre_internal.h"
2379
2380 to pcre_chartables.c because without it, gcc 4.x may remove the array
2381 definition from the final binary if PCRE is built into a static library and
2382 dead code stripping is activated.
2383
2384 46. For an unanchored pattern, if a match attempt fails at the start of a
2385 newline sequence, and the newline setting is CRLF or ANY, and the next two
2386 characters are CRLF, advance by two characters instead of one.
2387
2388
2389 Version 6.7 04-Jul-06
2390 ---------------------
2391
2392 1. In order to handle tests when input lines are enormously long, pcretest has
2393 been re-factored so that it automatically extends its buffers when
2394 necessary. The code is crude, but this _is_ just a test program. The
2395 default size has been increased from 32K to 50K.
2396
2397 2. The code in pcre_study() was using the value of the re argument before
2398 testing it for NULL. (Of course, in any sensible call of the function, it
2399 won't be NULL.)
2400
2401 3. The memmove() emulation function in pcre_internal.h, which is used on
2402 systems that lack both memmove() and bcopy() - that is, hardly ever -
2403 was missing a "static" storage class specifier.
2404
2405 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
2406 containing an extended class (one that cannot be represented by a bitmap
2407 because it contains high-valued characters or Unicode property items, e.g.
2408 [\pZ]). Almost always one would set UTF-8 mode when processing such a
2409 pattern, but PCRE should not loop if you do not (it no longer does).
2410 [Detail: two cases were found: (a) a repeated subpattern containing an
2411 extended class; (b) a recursive reference to a subpattern that followed a
2412 previous extended class. It wasn't skipping over the extended class
2413 correctly when UTF-8 mode was not set.]
2414
2415 5. A negated single-character class was not being recognized as fixed-length
2416 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
2417 compile error "lookbehind assertion is not fixed length".
2418
2419 6. The RunPerlTest auxiliary script was showing an unexpected difference
2420 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
2421 write a Perl script that can interpret lines of an input file either as
2422 byte characters or as UTF-8, which is what "perltest" was being required to
2423 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
2424 can't do is switch easily at run time between having the "use utf8;" pragma
2425 or not. In the end, I fudged it by using the RunPerlTest script to insert
2426 "use utf8;" explicitly for the UTF-8 tests.
2427
2428 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
2429 the end of the subject string, contrary to the documentation and to what
2430 Perl does. This was true of both matching functions. Now it matches only at
2431 the start of the subject and immediately after *internal* newlines.
2432
2433 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
2434 a pointer to an int instead of a pointer to an unsigned long int. This
2435 caused problems on 64-bit systems.
2436
2437 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
2438 instance of the 'standard' template library not being so standard".
2439
2440 10. There was no check on the number of named subpatterns nor the maximum
2441 length of a subpattern name. The product of these values is used to compute
2442 the size of the memory block for a compiled pattern. By supplying a very
2443 long subpattern name and a large number of named subpatterns, the size
2444 computation could be caused to overflow. This is now prevented by limiting
2445 the length of names to 32 characters, and the number of named subpatterns
2446 to 10,000.
2447
2448 11. Subpatterns that are repeated with specific counts have to be replicated in
2449 the compiled pattern. The size of memory for this was computed from the
2450 length of the subpattern and the repeat count. The latter is limited to
2451 65535, but there was no limit on the former, meaning that integer overflow
2452 could in principle occur. The compiled length of a repeated subpattern is
2453 now limited to 30,000 bytes in order to prevent this.
2454
2455 12. Added the optional facility to have named substrings with the same name.
2456
2457 13. Added the ability to use a named substring as a condition, using the
2458 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
2459 are numbers (not recommended). Forward references are permitted.
2460
2461 14. Added forward references in named backreferences (if you see what I mean).
2462
2463 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
2464 pattern could run off the end of the subject. For example, the pattern
2465 "(?s)(.{1,5})"8 did this with the subject "ab".
2466
2467 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
2468 PCRE_CASELESS was set when matching characters that were quantified with ?
2469 or *.
2470
2471 17. A character class other than a single negated character that had a minimum
2472 but no maximum quantifier - for example [ab]{6,} - was not handled
2473 correctly by pce_dfa_exec(). It would match only one character.
2474
2475 18. A valid (though odd) pattern that looked like a POSIX character
2476 class but used an invalid character after [ (for example [[,abc,]]) caused
2477 pcre_compile() to give the error "Failed: internal error: code overflow" or
2478 in some cases to crash with a glibc free() error. This could even happen if
2479 the pattern terminated after [[ but there just happened to be a sequence of
2480 letters, a binary zero, and a closing ] in the memory that followed.
2481
2482 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
2483 over the years. Originally (before any Unicode support), just the bottom 8
2484 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
2485 output from "man perlunicode" includes this:
2486
2487 The regular expression compiler produces polymorphic opcodes. That
2488 is, the pattern adapts to the data and automatically switches to
2489 the Unicode character scheme when presented with Unicode data--or
2490 instead uses a traditional byte scheme when presented with byte
2491 data.
2492
2493 Sadly, a wide octal escape does not cause a switch, and in a string with
2494 no other multibyte characters, these octal escapes are treated as before.
2495 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
2496 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
2497 Unicode string.
2498
2499 I have not perpetrated such confusion in PCRE. Up till now, it took just
2500 the bottom 8 bits, as in old Perl. I have now made octal escapes with
2501 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
2502 translate to the appropriate multibyte character.
2503
2504 29. Applied some refactoring to reduce the number of warnings from Microsoft
2505 and Borland compilers. This has included removing the fudge introduced
2506 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
2507 a warning about an unused variable.
2508
2509 21. PCRE has not included VT (character 0x0b) in the set of whitespace
2510 characters since release 4.0, because Perl (from release 5.004) does not.
2511 [Or at least, is documented not to: some releases seem to be in conflict
2512 with the documentation.] However, when a pattern was studied with
2513 pcre_study() and all its branches started with \s, PCRE still included VT
2514 as a possible starting character. Of course, this did no harm; it just
2515 caused an unnecessary match attempt.
2516
2517 22. Removed a now-redundant internal flag bit that recorded the fact that case
2518 dependency changed within the pattern. This was once needed for "required
2519 byte" processing, but is no longer used. This recovers a now-scarce options
2520 bit. Also moved the least significant internal flag bit to the most-
2521 significant bit of the word, which was not previously used (hangover from
2522 the days when it was an int rather than a uint) to free up another bit for
2523 the future.
2524
2525 23. Added support for CRLF line endings as well as CR and LF. As well as the
2526 default being selectable at build time, it can now be changed at runtime
2527 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
2528 specify that it is scanning data with non-default line endings.
2529
2530 24. Changed the definition of CXXLINK to make it agree with the definition of
2531 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
2532
2533 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
2534 recursions. This makes a big different to stack usage for some patterns.
2535
2536 26. If a subpattern containing a named recursion or subroutine reference such
2537 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
2538 the space required for the compiled pattern went wrong and gave too small a
2539 value. Depending on the environment, this could lead to "Failed: internal
2540 error: code overflow at offset 49" or "glibc detected double free or
2541 corruption" errors.
2542
2543 27. Applied patches from Google (a) to support the new newline modes and (b) to
2544 advance over multibyte UTF-8 characters in GlobalReplace.
2545
2546 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
2547 difference for some implementation of PCRE in some Windows version.
2548
2549 29. Added some extra testing facilities to pcretest:
2550
2551 \q<number> in a data line sets the "match limit" value
2552 \Q<number> in a data line sets the "match recursion limt" value
2553 -S <number> sets the stack size, where <number> is in megabytes
2554
2555 The -S option isn't available for Windows.
2556
2557
2558 Version 6.6 06-Feb-06
2559 ---------------------
2560
2561 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
2562 in pcreposix.h. I have copied the definition from pcre.h.
2563
2564 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
2565 because pcre.h is no longer a built file.
2566
2567 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
2568 not normally included in the compiled code.
2569
2570
2571 Version 6.5 01-Feb-06
2572 ---------------------
2573
2574 1. When using the partial match feature with pcre_dfa_exec(), it was not
2575 anchoring the second and subsequent partial matches at the new starting
2576 point. This could lead to incorrect results. For example, with the pattern
2577 /1234/, partially matching against "123" and then "a4" gave a match.
2578
2579 2. Changes to pcregrep:
2580
2581 (a) All non-match returns from pcre_exec() were being treated as failures
2582 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
2583 error message is output. Some extra information is given for the
2584 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
2585 probably the only errors that are likely to be caused by users (by
2586 specifying a regex that has nested indefinite repeats, for instance).
2587 If there are more than 20 of these errors, pcregrep is abandoned.
2588
2589 (b) A binary zero was treated as data while matching, but terminated the
2590 output line if it was written out. This has been fixed: binary zeroes
2591 are now no different to any other data bytes.
2592
2593 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
2594 used to set a locale for matching. The --locale=xxxx long option has
2595 been added (no short equivalent) to specify a locale explicitly on the
2596 pcregrep command, overriding the environment variables.
2597
2598 (d) When -B was used with -n, some line numbers in the output were one less
2599 than they should have been.
2600
2601 (e) Added the -o (--only-matching) option.
2602
2603 (f) If -A or -C was used with -c (count only), some lines of context were
2604 accidentally printed for the final match.
2605
2606 (g) Added the -H (--with-filename) option.
2607
2608 (h) The combination of options -rh failed to suppress file names for files
2609 that were found from directory arguments.
2610
2611 (i) Added the -D (--devices) and -d (--directories) options.
2612
2613 (j) Added the -F (--fixed-strings) option.
2614
2615 (k) Allow "-" to be used as a file name for -f as well as for a data file.
2616
2617 (l) Added the --colo(u)r option.
2618
2619 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
2620 is not present by default.
2621
2622 3. A nasty bug was discovered in the handling of recursive patterns, that is,
2623 items such as (?R) or (?1), when the recursion could match a number of
2624 alternatives. If it matched one of the alternatives, but subsequently,
2625 outside the recursion, there was a failure, the code tried to back up into
2626 the recursion. However, because of the way PCRE is implemented, this is not
2627 possible, and the result was an incorrect result from the match.
2628
2629 In order to prevent this happening, the specification of recursion has
2630 been changed so that all such subpatterns are automatically treated as
2631 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
2632
2633 4. I had overlooked the fact that, in some locales, there are characters for
2634 which isalpha() is true but neither isupper() nor islower() are true. In
2635 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
2636 and ordfeminine) are like this. This affected the treatment of \w and \W
2637 when they appeared in character classes, but not when they appeared outside
2638 a character class. The bit map for "word" characters is now created
2639 separately from the results of isalnum() instead of just taking it from the
2640 upper, lower, and digit maps. (Plus the underscore character, of course.)
2641
2642 5. The above bug also affected the handling of POSIX character classes such as
2643 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
2644 permanent tables. Instead, the bit maps for such a class were previously
2645 created as the appropriate unions of the upper, lower, and digit bitmaps.
2646 Now they are created by subtraction from the [[:word:]] class, which has
2647 its own bitmap.
2648
2649 6. The [[:blank:]] character class matches horizontal, but not vertical space.
2650 It is created by subtracting the vertical space characters (\x09, \x0a,
2651 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
2652 subtraction was done in the overall bitmap for a character class, meaning
2653 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
2654 be recognized. This bug has been fixed.
2655
2656 7. Patches from the folks at Google:
2657
2658 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
2659 real life, but is still worth protecting against".
2660
2661 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
2662 regular expressions".
2663
2664 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
2665 have it.
2666
2667 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
2668 "configure" and the latter not, in order to fix a problem somebody had
2669 with compiling the Arg class on HP-UX.
2670
2671 (e) Improve the error-handling of the C++ wrapper a little bit.
2672
2673 (f) New tests for checking recursion limiting.
2674
2675 8. The pcre_memmove() function, which is used only if the environment does not
2676 have a standard memmove() function (and is therefore rarely compiled),
2677 contained two bugs: (a) use of int instead of size_t, and (b) it was not
2678 returning a result (though PCRE never actually uses the result).
2679
2680 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
2681 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
2682 returned instead of calling malloc() with an overflowing number that would
2683 most likely cause subsequent chaos.
2684
2685 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
2686
2687 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
2688 with this option is matched, the nmatch and pmatch options of regexec() are
2689 ignored.
2690
2691 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
2692 provided in case anyone wants to the the POSIX interface with UTF-8
2693 strings.
2694
2695 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
2696 C++ linking (needed for some HP-UX environments).
2697
2698 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
2699 (unused parameter) and in the pcre_printint() function (omitted "default"
2700 switch label when the default is to do nothing).
2701
2702 15. Added some code to make it possible, when PCRE is compiled as a C++
2703 library, to replace subject pointers for pcre_exec() with a smart pointer
2704 class, thus making it possible to process discontinuous strings.
2705
2706 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
2707 much the same function. They were added by different people who were trying
2708 to make PCRE easy to compile on non-Unix systems. It has been suggested
2709 that PCRE_EXPORT be abolished now that there is more automatic apparatus
2710 for compiling on Windows systems. I have therefore replaced it with
2711 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
2712 defaults to "extern" for C or "extern C" for C++, which works fine on
2713 Unix-like systems. It is now possible to override the value of PCRE_DATA_
2714 SCOPE with something explicit in config.h. In addition:
2715
2716 (a) pcreposix.h still had just "extern" instead of either of these macros;
2717 I have replaced it with PCRE_DATA_SCOPE.
2718
2719 (b) Functions such as _pcre_xclass(), which are internal to the library,
2720 but external in the C sense, all had PCRE_EXPORT in their definitions.
2721 This is apparently wrong for the Windows case, so I have removed it.
2722 (It makes no difference on Unix-like systems.)
2723
2724 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
2725 of recursive calls to match(). This is different to MATCH_LIMIT because
2726 that limits the total number of calls to match(), not all of which increase
2727 the depth of recursion. Limiting the recursion depth limits the amount of
2728 stack (or heap if NO_RECURSE is set) that is used. The default can be set
2729 when PCRE is compiled, and changed at run time. A patch from Google adds
2730 this functionality to the C++ interface.
2731
2732 18. Changes to the handling of Unicode character properties:
2733
2734 (a) Updated the table to Unicode 4.1.0.
2735
2736 (b) Recognize characters that are not in the table as "Cn" (undefined).
2737
2738 (c) I revised the way the table is implemented to a much improved format
2739 which includes recognition of ranges. It now supports the ranges that
2740 are defined in UnicodeData.txt, and it also amalgamates other
2741 characters into ranges. This has reduced the number of entries in the
2742 table from around 16,000 to around 3,000, thus reducing its size
2743 considerably. I realized I did not need to use a tree structure after
2744 all - a binary chop search is just as efficient. Having reduced the
2745 number of entries, I extended their size from 6 bytes to 8 bytes to
2746 allow for more data.
2747
2748 (d) Added support for Unicode script names via properties such as \p{Han}.
2749
2750 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
2751 matching that character.
2752
2753 20. When matching a repeated Unicode property with a minimum greater than zero,
2754 (for example \pL{2,}), PCRE could look past the end of the subject if it
2755 reached it while seeking the minimum number of characters. This could
2756 happen only if some of the characters were more than one byte long, because
2757 there is a check for at least the minimum number of bytes.
2758
2759 21. Refactored the implementation of \p and \P so as to be more general, to
2760 allow for more different types of property in future. This has changed the
2761 compiled form incompatibly. Anybody with saved compiled patterns that use
2762 \p or \P will have to recompile them.
2763
2764 22. Added "Any" and "L&" to the supported property types.
2765
2766 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
2767 but give a compile time error if the value is greater than 0xff.
2768
2769 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
2770 accidentally not being installed or uninstalled.
2771
2772 25. The pcre.h file was built from pcre.h.in, but the only changes that were
2773 made were to insert the current release number. This seemed silly, because
2774 it made things harder for people building PCRE on systems that don't run
2775 "configure". I have turned pcre.h into a distributed file, no longer built
2776 by "configure", with the version identification directly included. There is
2777 no longer a pcre.h.in file.
2778
2779 However, this change necessitated a change to the pcre-config script as
2780 well. It is built from pcre-config.in, and one of the substitutions was the
2781 release number. I have updated configure.ac so that ./configure now finds
2782 the release number by grepping pcre.h.
2783
2784 26. Added the ability to run the tests under valgrind.
2785
2786
2787 Version 6.4 05-Sep-05
2788 ---------------------
2789
2790 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
2791 "--" to be printed when multiple files were scanned, even when none of the
2792 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
2793 consider it to be a bug, and have restored the previous behaviour.
2794
2795 2. A couple of code tidies to get rid of compiler warnings.
2796
2797 3. The pcretest program used to cheat by referring to symbols in the library
2798 whose names begin with _pcre_. These are internal symbols that are not
2799 really supposed to be visible externally, and in some environments it is
2800 possible to suppress them. The cheating is now confined to including
2801 certain files from the library's source, which is a bit cleaner.
2802
2803 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
2804 file's purpose clearer.
2805
2806 5. Reorganized pcre_ucp_findchar().
2807
2808
2809 Version 6.3 15-Aug-05
2810 ---------------------
2811
2812 1. The file libpcre.pc.in did not have general read permission in the tarball.
2813
2814 2. There were some problems when building without C++ support:
2815
2816 (a) If C++ support was not built, "make install" and "make test" still
2817 tried to test it.
2818
2819 (b) There were problems when the value of CXX was explicitly set. Some
2820 changes have been made to try to fix these, and ...
2821
2822 (c) --disable-cpp can now be used to explicitly disable C++ support.
2823
2824 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
2825 backslash in a target when C++ was disabled. This confuses some
2826 versions of "make", apparently. Using an intermediate variable solves
2827 this. (Same for CPP_LOBJ.)
2828
2829 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
2830 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
2831 necessary on certain architectures.
2832
2833 4. Added a setting of -export-symbols-regex to the link command to remove
2834 those symbols that are exported in the C sense, but actually are local
2835 within the library, and not documented. Their names all begin with
2836 "_pcre_". This is not a perfect job, because (a) we have to except some
2837 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
2838 available (and never for static libraries). I have made a note to try to
2839 find a way round (a) in the future.
2840
2841
2842 Version 6.2 01-Aug-05
2843 ---------------------
2844
2845 1. There was no test for integer overflow of quantifier values. A construction
2846 such as {1111111111111111} would give undefined results. What is worse, if
2847 a minimum quantifier for a parenthesized subpattern overflowed and became
2848 negative, the calculation of the memory size went wrong. This could have
2849 led to memory overwriting.
2850
2851 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
2852
2853 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
2854 operating environments where this matters.
2855
2856 4. Applied Giuseppe Maxia's patch to add additional features for controlling
2857 PCRE options from within the C++ wrapper.
2858
2859 5. Named capturing subpatterns were not being correctly counted when a pattern
2860 was compiled. This caused two problems: (a) If there were more than 100
2861 such subpatterns, the calculation of the memory needed for the whole
2862 compiled pattern went wrong, leading to an overflow error. (b) Numerical
2863 back references of the form \12, where the number was greater than 9, were
2864 not recognized as back references, even though there were sufficient
2865 previous subpatterns.
2866
2867 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
2868 versions of gcc, e.g. 2.95.4.
2869
2870
2871 Version 6.1 21-Jun-05
2872 ---------------------
2873
2874 1. There was one reference to the variable "posix" in pcretest.c that was not
2875 surrounded by "#if !defined NOPOSIX".
2876
2877 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
2878 the cross-check on the old pcre_info() function, for the benefit of the
2879 cut-down version of PCRE that is currently imported into Exim.
2880
2881 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
2882 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
2883 patterns that start (?i) but I don't think that matters. The use of (?i) is
2884 just an example; this all applies to the other options as well.
2885
2886 4. Since libtool seems to echo the compile commands it is issuing, the output
2887 from "make" can be reduced a bit by putting "@" in front of each libtool
2888 compile command.
2889
2890 5. Patch from the folks at Google for configure.in to be a bit more thorough
2891 in checking for a suitable C++ installation before trying to compile the
2892 C++ stuff. This should fix a reported problem when a compiler was present,
2893 but no suitable headers.
2894
2895 6. The man pages all had just "PCRE" as their title. I have changed them to
2896 be the relevant file name. I have also arranged that these names are
2897 retained in the file doc/pcre.txt, which is a concatenation in text format
2898 of all the man pages except the little individual ones for each function.
2899
2900 7. The NON-UNIX-USE file had not been updated for the different set of source
2901 files that come with release 6. I also added a few comments about the C++
2902 wrapper.
2903
2904
2905 Version 6.0 07-Jun-05
2906 ---------------------
2907
2908 1. Some minor internal re-organization to help with my DFA experiments.
2909
2910 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
2911 didn't matter for the library itself when fully configured, but did matter
2912 when compiling without UCP support, or within Exim, where the ucp files are
2913 not imported.
2914
2915 3. Refactoring of the library code to split up the various functions into
2916 different source modules. The addition of the new DFA matching code (see
2917 below) to a single monolithic source would have made it really too
2918 unwieldy, quite apart from causing all the code to be include in a
2919 statically linked application, when only some functions are used. This is
2920 relevant even without the DFA addition now that patterns can be compiled in
2921 one application and matched in another.
2922
2923 The downside of splitting up is that there have to be some external
2924 functions and data tables that are used internally in different modules of
2925 the library but which are not part of the API. These have all had their
2926 names changed to start with "_pcre_" so that they are unlikely to clash
2927 with other external names.
2928
2929 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
2930 a different (DFA) algorithm. Although it is slower than the original
2931 function, it does have some advantages for certain types of matching
2932 problem.
2933
2934 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
2935 including restarting after a partial match.
2936
2937 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
2938 defined when compiling for Windows was sent to me. I have put it into the
2939 code, though I have no means of testing or verifying it.
2940
2941 7. Added the pcre_refcount() auxiliary function.
2942
2943 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
2944 match before or at the first newline in the subject string. In pcretest,
2945 the /f option on a pattern can be used to set this.
2946
2947 9. A repeated \w when used in UTF-8 mode with characters greater than 256
2948 would behave wrongly. This has been present in PCRE since release 4.0.
2949
2950 10. A number of changes to the pcregrep command:
2951
2952 (a) Refactored how -x works; insert ^(...)$ instead of setting
2953 PCRE_ANCHORED and checking the length, in preparation for adding
2954 something similar for -w.
2955
2956 (b) Added the -w (match as a word) option.
2957
2958 (c) Refactored the way lines are read and buffered so as to have more
2959 than one at a time available.
2960
2961 (d) Implemented a pcregrep test script.
2962
2963 (e) Added the -M (multiline match) option. This allows patterns to match
2964 over several lines of the subject. The buffering ensures that at least
2965 8K, or the rest of the document (whichever is the shorter) is available
2966 for matching (and similarly the previous 8K for lookbehind assertions).
2967
2968 (f) Changed the --help output so that it now says
2969
2970 -w, --word-regex(p)
2971
2972 instead of two lines, one with "regex" and the other with "regexp"
2973 because that confused at least one person since the short forms are the
2974 same. (This required a bit of code, as the output is generated
2975 automatically from a table. It wasn't just a text change.)
2976
2977 (g) -- can be used to terminate pcregrep options if the next thing isn't an
2978 option but starts with a hyphen. Could be a pattern or a path name
2979 starting with a hyphen, for instance.
2980
2981 (h) "-" can be given as a file name to represent stdin.
2982
2983 (i) When file names are being printed, "(standard input)" is used for
2984 the standard input, for compatibility with GNU grep. Previously
2985 "<stdin>" was used.
2986
2987 (j) The option --label=xxx can be used to supply a name to be used for
2988 stdin when file names are being printed. There is no short form.
2989
2990 (k) Re-factored the options decoding logic because we are going to add
2991 two more options that take data. Such options can now be given in four
2992 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
2993
2994 (l) Added the -A, -B, and -C options for requesting that lines of context
2995 around matches be printed.
2996
2997 (m) Added the -L option to print the names of files that do not contain
2998 any matching lines, that is, the complement of -l.
2999
3000 (n) The return code is 2 if any file cannot be opened, but pcregrep does
3001 continue to scan other files.
3002
3003 (o) The -s option was incorrectly implemented. For compatibility with other
3004 greps, it now suppresses the error message for a non-existent or non-
3005 accessible file (but not the return code). There is a new option called
3006 -q that suppresses the output of matching lines, which was what -s was
3007 previously doing.
3008
3009 (p) Added --include and --exclude options to specify files for inclusion
3010 and exclusion when recursing.
3011
3012 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
3013 Hopefully, it now does.
3014
3015 12. Missing cast in pcre_study().
3016
3017 13. Added an "uninstall" target to the makefile.
3018
3019 14. Replaced "extern" in the function prototypes in Makefile.in with
3020 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
3021 world, but is set differently for Windows.
3022
3023 15. Added a second compiling function called pcre_compile2(). The only
3024 difference is that it has an extra argument, which is a pointer to an
3025 integer error code. When there is a compile-time failure, this is set
3026 non-zero, in addition to the error test pointer being set to point to an
3027 error message. The new argument may be NULL if no error number is required
3028 (but then you may as well call pcre_compile(), which is now just a
3029 wrapper). This facility is provided because some applications need a
3030 numeric error indication, but it has also enabled me to tidy up the way
3031 compile-time errors are handled in the POSIX wrapper.
3032
3033 16. Added VPATH=.libs to the makefile; this should help when building with one
3034 prefix path and installing with another. (Or so I'm told by someone who
3035 knows more about this stuff than I do.)
3036
3037 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
3038 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
3039 match everything, including newlines. This is not POSIX-compatible, but
3040 somebody wanted the feature. From pcretest it can be activated by using
3041 both the P and the s flags.
3042
3043 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
3044
3045 19. libpcre.pc was being incorrectly installed as executable.
3046
3047 20. A couple of places in pcretest check for end-of-line by looking for '\n';
3048 it now also looks for '\r' so that it will work unmodified on Windows.
3049
3050 21. Added Google's contributed C++ wrapper to the distribution.
3051
3052 22. Added some untidy missing memory free() calls in pcretest, to keep
3053 Electric Fence happy when testing.
3054
3055
3056
3057 Version 5.0 13-Sep-04
3058 ---------------------
3059
3060 1. Internal change: literal characters are no longer packed up into items
3061 containing multiple characters in a single byte-string. Each character
3062 is now matched using a separate opcode. However, there may be more than one
3063 byte in the character in UTF-8 mode.
3064
3065 2. The pcre_callout_block structure has two new fields: pattern_position and
3066 next_item_length. These contain the offset in the pattern to the next match
3067 item, and its length, respectively.
3068
3069 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
3070 insertion of callouts before each pattern item. Added the /C option to
3071 pcretest to make use of this.
3072
3073 4. On the advice of a Windows user, the lines
3074
3075 #if defined(_WIN32) || defined(WIN32)
3076 _setmode( _fileno( stdout ), 0x8000 );
3077 #endif /* defined(_WIN32) || defined(WIN32) */
3078
3079 have been added to the source of pcretest. This apparently does useful
3080 magic in relation to line terminators.
3081
3082 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
3083 for the benefit of those environments where the "b" makes a difference.
3084
3085 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
3086 to know about it. I have put a hack into configure.in that adds in code
3087 to set GCC=yes if CC=icc. This seems to end up at a point in the
3088 generated configure script that is early enough to affect the setting of
3089 compiler options, which is what is needed, but I have no means of testing
3090 whether it really works. (The user who reported this had patched the
3091 generated configure script, which of course I cannot do.)
3092
3093 LATER: After change 22 below (new libtool files), the configure script
3094 seems to know about icc (and also ecc). Therefore, I have commented out
3095 this hack in configure.in.
3096
3097 7. Added support for pkg-config (2 patches were sent in).
3098
3099 8. Negated POSIX character classes that used a combination of internal tables
3100 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
3101 [[:^ascii]]. Typically, they would match almost any characters. The other
3102 POSIX classes were not broken in this way.
3103
3104 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
3105 to find the match, as PCRE was deluded into thinking that the match had to
3106 start at the start point or following a newline. The same bug applied to
3107 patterns with negative forward assertions or any backward assertions
3108 preceding ".*" at the start, unless the pattern required a fixed first
3109 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
3110
3111 10. In UTF-8 mode, when moving forwards in the subject after a failed match
3112 starting at the last subject character, bytes beyond the end of the subject
3113 string were read.
3114
3115 11. Renamed the variable "class" as "classbits" to make life easier for C++
3116 users. (Previously there was a macro definition, but it apparently wasn't
3117 enough.)
3118
3119 12. Added the new field "tables" to the extra data so that tables can be passed
3120 in at exec time, or the internal tables can be re-selected. This allows
3121 a compiled regex to be saved and re-used at a later time by a different
3122 program that might have everything at different addresses.
3123
3124 13. Modified the pcre-config script so that, when run on Solaris, it shows a
3125 -R library as well as a -L library.
3126
3127 14. The debugging options of pcretest (-d on the command line or D on a
3128 pattern) showed incorrect output for anything following an extended class
3129 that contained multibyte characters and which was followed by a quantifier.
3130
3131 15. Added optional support for general category Unicode character properties
3132 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
3133 support. It adds about 90K to the size of the library. The meanings of the
3134 inbuilt class escapes such as \d and \s have NOT been changed.
3135
3136 16. Updated pcredemo.c to include calls to free() to release the memory for the
3137 compiled pattern.
3138
3139 17. The generated file chartables.c was being created in the source directory
3140 instead of in the building directory. This caused the build to fail if the
3141 source directory was different from the building directory, and was
3142 read-only.
3143
3144 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
3145 file. No doubt somebody will tell me if they don't make sense... Also added
3146 Dan Mooney's comments about building on OpenVMS.
3147
3148 19. Added support for partial matching via the PCRE_PARTIAL option for
3149 pcre_exec() and the \P data escape in pcretest.
3150
3151 20. Extended pcretest with 3 new pattern features:
3152
3153 (i) A pattern option of the form ">rest-of-line" causes pcretest to
3154 write the compiled pattern to the file whose name is "rest-of-line".
3155 This is a straight binary dump of the data, with the saved pointer to
3156 the character tables forced to be NULL. The study data, if any, is
3157 written too. After writing, pcretest reads a new pattern.
3158
3159 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
3160 compiled pattern from the given file. There must not be any
3161 occurrences of "<" in the file name (pretty unlikely); if there are,
3162 pcretest will instead treat the initial "<" as a pattern delimiter.
3163 After reading in the pattern, pcretest goes on to read data lines as
3164 usual.
3165
3166 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
3167 and 16-bit fields in a compiled pattern, to simulate a pattern that
3168 was compiled on a host of opposite endianness.
3169
3170 21. The pcre-exec() function can now cope with patterns that were compiled on
3171 hosts of opposite endianness, with this restriction:
3172
3173 As for any compiled expression that is saved and used later, the tables
3174 pointer field cannot be preserved; the extra_data field in the arguments
3175 to pcre_exec() should be used to pass in a tables address if a value
3176 other than the default internal tables were used at compile time.
3177
3178 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
3179 now diagnosed as an error. Previously, most of the time, a negative number
3180 would have been treated as zero, but if in addition "ovector" was passed as
3181 NULL, a crash could occur.
3182
3183 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
3184 new versions from the libtool 1.5 distribution (the last one is a copy of
3185 a file called libtool.m4). This seems to have fixed the need to patch
3186 "configure" to support Darwin 1.3 (which I used to do). However, I still
3187 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
3188 workstation).
3189
3190 24. Changed the PCRE licence to be the more standard "BSD" licence.
3191
3192
3193 Version 4.5 01-Dec-03
3194 ---------------------
3195
3196 1. There has been some re-arrangement of the code for the match() function so
3197 that it can be compiled in a version that does not call itself recursively.
3198 Instead, it keeps those local variables that need separate instances for
3199 each "recursion" in a frame on the heap, and gets/frees frames whenever it
3200 needs to "recurse". Keeping track of where control must go is done by means
3201 of setjmp/longjmp. The whole thing is implemented by a set of macros that
3202 hide most of the details from the main code, and operates only if
3203 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
3204 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
3205 operating.
3206
3207 To make it easier for callers to provide specially tailored get/free
3208 functions for this usage, two new functions, pcre_stack_malloc, and
3209 pcre_stack_free, are used. They are always called in strict stacking order,
3210 and the size of block requested is always the same.
3211
3212 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
3213 PCRE has been compiled to use the stack or the heap for recursion. The
3214 -C option of pcretest uses this to show which version is compiled.
3215
3216 A new data escape \S, is added to pcretest; it causes the amounts of store
3217 obtained and freed by both kinds of malloc/free at match time to be added
3218 to the output.
3219
3220 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
3221 what's available on my current Linux desktop machine.
3222
3223 3. When matching a UTF-8 string, the test for a valid string at the start has
3224 been extended. If start_offset is not zero, PCRE now checks that it points
3225 to a byte that is the start of a UTF-8 character. If not, it returns
3226 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
3227 this is necessary because there may be backward assertions in the pattern.
3228 When matching the same subject several times, it may save resources to use
3229 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
3230
3231 4. The code for checking the validity of UTF-8 strings has been tightened so
3232 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
3233 containing "overlong sequences".
3234
3235 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
3236 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
3237 should have been "&", but it just so happened that all the cases this let
3238 through by mistake were picked up later in the function.
3239
3240 6. I had used a variable called "isblank" - this is a C99 function, causing
3241 some compilers to warn. To avoid this, I renamed it (as "blankclass").
3242
3243 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
3244 prompting; (b) run "./pcretest /dev/null" at the start of the test script
3245 so the version is shown; (c) stop "make test" echoing "./RunTest".
3246
3247 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
3248
3249 9. The prototype for memmove() for systems that don't have it was using
3250 size_t, but the inclusion of the header that defines size_t was later. I've
3251 moved the #includes for the C headers earlier to avoid this.
3252
3253 10. Added some adjustments to the code to make it easier to compiler on certain
3254 special systems:
3255
3256 (a) Some "const" qualifiers were missing.
3257 (b) Added the macro EXPORT before all exported functions; by default this
3258 is defined to be empty.
3259 (c) Changed the dftables auxiliary program (that builds chartables.c) so
3260 that it reads its output file name as an argument instead of writing
3261 to the standard output and assuming this can be redirected.
3262
3263 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
3264 class containing characters with values greater than 255, PCRE compilation
3265 went into a loop.
3266
3267 12. A recursive reference to a subpattern that was within another subpattern
3268 that had a minimum quantifier of zero caused PCRE to crash. For example,
3269 (x(y(?2))z)? provoked this bug with a subject that got as far as the
3270 recursion. If the recursively-called subpattern itself had a zero repeat,
3271 that was OK.
3272
3273 13. In pcretest, the buffer for reading a data line was set at 30K, but the
3274 buffer into which it was copied (for escape processing) was still set at
3275 1024, so long lines caused crashes.
3276
3277 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
3278 "internal error: code overflow...". This applied to any character class
3279 that was followed by a possessive quantifier.
3280
3281 15. Modified the Makefile to add libpcre.la as a prerequisite for
3282 libpcreposix.la because I was told this is needed for a parallel build to
3283 work.
3284
3285 16. If a pattern that contained .* following optional items at the start was
3286 studied, the wrong optimizing data was generated, leading to matching
3287 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
3288 matching string must start with a or b or c. The correct conclusion for
3289 this pattern is that a match can start with any character.
3290
3291
3292 Version 4.4 13-Aug-03
3293 ---------------------
3294
3295 1. In UTF-8 mode, a character class containing characters with values between
3296 127 and 255 was not handled correctly if the compiled pattern was studied.
3297 In fixing this, I have also improved the studying algorithm for such
3298 classes (slightly).
3299
3300 2. Three internal functions had redundant arguments passed to them. Removal
3301 might give a very teeny performance improvement.
3302
3303 3. Documentation bug: the value of the capture_top field in a callout is *one
3304 more than* the number of the hightest numbered captured substring.
3305
3306 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
3307 in incorrectly linking with a previously installed version. They now link
3308 explicitly with libpcre.la.
3309
3310 5. configure.in no longer needs to recognize Cygwin specially.
3311
3312 6. A problem in pcre.in for Windows platforms is fixed.
3313
3314 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
3315 pcretest, it used to include the size of the study block as part of its
3316 output. Unfortunately, the structure contains a field that has a different
3317 size on different hardware architectures. This meant that the tests that
3318 showed this size failed. As the block is currently always of a fixed size,
3319 this information isn't actually particularly useful in pcretest output, so
3320 I have just removed it.
3321
3322 8. Three pre-processor statements accidentally did not start in column 1.
3323 Sadly, there are *still* compilers around that complain, even though
3324 standard C has not required this for well over a decade. Sigh.
3325
3326 9. In pcretest, the code for checking callouts passed small integers in the
3327 callout_data field, which is a void * field. However, some picky compilers
3328 complained about the casts involved for this on 64-bit systems. Now
3329 pcretest passes the address of the small integer instead, which should get
3330 rid of the warnings.
3331
3332 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
3333 both compile and run time, and gives an error if an invalid UTF-8 sequence
3334 is found. There is a option for disabling this check in cases where the
3335 string is known to be correct and/or the maximum performance is wanted.
3336
3337 11. In response to a bug report, I changed one line in Makefile.in from
3338
3339 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
3340 to
3341 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
3342
3343 to look similar to other lines, but I have no way of telling whether this
3344 is the right thing to do, as I do not use Windows. No doubt I'll get told
3345 if it's wrong...
3346
3347
3348 Version 4.3 21-May-03
3349 ---------------------
3350
3351 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
3352 Makefile.
3353
3354 2. Some refactoring to improve the quality of the code:
3355
3356 (i) The utf8_table... variables are now declared "const".
3357
3358 (ii) The code for \cx, which used the "case flipping" table to upper case
3359 lower case letters, now just substracts 32. This is ASCII-specific,
3360 but the whole concept of \cx is ASCII-specific, so it seems
3361 reasonable.
3362
3363 (iii) PCRE was using its character types table to recognize decimal and
3364 hexadecimal digits in the pattern. This is silly, because it handles
3365 only 0-9, a-f, and A-F, but the character types table is locale-
3366 specific, which means strange things might happen. A private
3367 table is now used for this - though it costs 256 bytes, a table is
3368 much faster than multiple explicit tests. Of course, the standard
3369 character types table is still used for matching digits in subject
3370 strings against \d.
3371
3372 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
3373 ending in _t are). So I've renamed it as ESC_tee.
3374
3375 3. The first argument for regexec() in the POSIX wrapper should have been
3376 defined as "const".
3377
3378 4. Changed pcretest to use malloc() for its buffers so that they can be
3379 Electric Fenced for debugging.
3380
3381 5. There were several places in the code where, in UTF-8 mode, PCRE would try
3382 to read one or more bytes before the start of the subject string. Often this
3383 had no effect on PCRE's behaviour, but in some circumstances it could
3384 provoke a segmentation fault.
3385
3386 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
3387 to try to read one or more bytes before the start of the subject string.
3388
3389 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
3390 UTF-8 support could misbehave in various ways if the subject string
3391 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
3392 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
3393 back over UTF-8 characters.)
3394
3395
3396 Version 4.2 14-Apr-03
3397 ---------------------
3398
3399 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
3400
3401 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
3402 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
3403 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
3404 [WIN_PREFIX]: new variable, "cyg" for Cygwin
3405 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
3406 and BUILD_EXEEXT
3407 Note: automatic setting of the BUILD variables is not yet working
3408 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
3409 compile-time but not at link-time
3410 [LINK]: use for linking executables only
3411 make different versions for Windows and non-Windows
3412 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
3413 libraries
3414 [LINK_FOR_BUILD]: new variable
3415 [OBJEXT]: use throughout
3416 [EXEEXT]: use throughout
3417 <winshared>: new target
3418 <wininstall>: new target
3419 <dftables.o>: use native compiler
3420 <dftables>: use native linker
3421 <install>: handle Windows platform correctly
3422 <clean>: ditto
3423 <check>: ditto
3424 copy DLL to top builddir before testing
3425
3426 As part of these changes, -no-undefined was removed again. This was reported
3427 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
3428 in any case.
3429
3430 3. Some tidies to get rid of compiler warnings:
3431
3432 . In the match_data structure, match_limit was an unsigned long int, whereas
3433 match_call_count was an int. I've made them both unsigned long ints.
3434
3435 . In pcretest the fact that a const uschar * doesn't automatically cast to
3436 a void * provoked a warning.
3437
3438 . Turning on some more compiler warnings threw up some "shadow" variables
3439 and a few more missing casts.
3440
3441 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
3442 option, a class that contained a single character with a value between 128
3443 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
3444
3445 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
3446 option, a class that contained several characters, but with at least one
3447 whose value was between 128 and 255 caused PCRE to crash.
3448
3449
3450 Version 4.1 12-Mar-03
3451 ---------------------
3452
3453 1. Compiling with gcc -pedantic found a couple of places where casts were
3454 needed, and a string in dftables.c that was longer than standard compilers are
3455 required to support.
3456
3457 2. Compiling with Sun's compiler found a few more places where the code could
3458 be tidied up in order to avoid warnings.
3459
3460 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
3461 first of these names is deprecated in the latest Autoconf in favour of the name
3462 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
3463 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
3464 analogy I have changed it to CFLAGS_FOR_BUILD.
3465
3466 4. Added -no-undefined to the linking command in the Makefile, because this is
3467 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
3468 linking step for the pcreposix library.
3469
3470 5. PCRE was failing to diagnose the case of two named groups with the same
3471 name.
3472
3473 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
3474 literal character that is needed in the subject for a match, and scans along to
3475 ensure that it is present before embarking on the full matching process. This
3476 saves time in cases of nested unlimited repeats that are never going to match.
3477 Problem: the scan can take a lot of time if the subject is very long (e.g.
3478 megabytes), thus penalizing straightforward matches. It is now done only if the
3479 amount of subject to be scanned is less than 1000 bytes.
3480
3481 7. A lesser problem with the same optimization is that it was recording the
3482 first character of an anchored pattern as "needed", thus provoking a search
3483 right along the subject, even when the first match of the pattern was going to
3484 fail. The "needed" character is now not set for anchored patterns, unless it
3485 follows something in the pattern that is of non-fixed length. Thus, it still
3486 fulfils its original purpose of finding quick non-matches in cases of nested
3487 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
3488
3489
3490 Version 4.0 17-Feb-03
3491 ---------------------
3492
3493 1. If a comment in an extended regex that started immediately after a meta-item
3494 extended to the end of string, PCRE compiled incorrect data. This could lead to
3495 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
3496
3497 2. Moved to autoconf 2.53 and libtool 1.4.2.
3498
3499 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
3500 the special perltest8 script is no longer needed - all the tests can be run
3501 from a single perltest script.
3502
3503 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
3504 by \s. It has now been removed in PCRE. This means it isn't recognized as
3505 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
3506 class [:space:] *does* include VT, thereby creating a mess.
3507
3508 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
3509 space and tab.
3510
3511 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
3512 its new features into the main test script, reducing the number of scripts.
3513
3514 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
3515 were backward compatible, and made the (?i) apply to the whole pattern, as if
3516 /i were given. Now it behaves more logically, and applies the option setting
3517 only to what follows. PCRE has been changed to follow suit. However, if it
3518 finds options settings right at the start of the pattern, it extracts them into
3519 the global options, as before. Thus, they show up in the info data.
3520
3521 8. Added support for the \Q...\E escape sequence. Characters in between are
3522 treated as literals. This is slightly different from Perl in that $ and @ are
3523 also handled as literals inside the quotes. In Perl, they will cause variable
3524 interpolation. Note the following examples:
3525
3526 Pattern PCRE matches Perl matches
3527
3528 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
3529 \Qabc\$xyz\E abc\$xyz abc\$xyz
3530 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
3531
3532 For compatibility with Perl, \Q...\E sequences are recognized inside character
3533 classes as well as outside them.
3534
3535 9. Re-organized 3 code statements in pcretest to avoid "overflow in
3536 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
3537 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
3538 signed/unsigned warnings.
3539
3540 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
3541 option for pcretest, so I've replaced it by a simple function that does just
3542 that job.
3543
3544 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
3545 "pcregrep -".
3546
3547 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
3548 Java package. This provides some syntactic sugar for simple cases of what my
3549 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
3550 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
3551 item, you can use this simplified notation. Note that only makes sense with
3552 greedy quantifiers. Consequently, the use of the possessive quantifier forces
3553 greediness, whatever the setting of the PCRE_UNGREEDY option.
3554
3555 13. A change of greediness default within a pattern was not taking effect at
3556 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
3557 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
3558 was abstracted outside.
3559
3560 14. PCRE now supports the \G assertion. It is true when the current matching
3561 position is at the start point of the match. This differs from \A when the
3562 starting offset is non-zero. Used with the /g option of pcretest (or similar
3563 code), it works in the same way as it does for Perl's /g option. If all
3564 alternatives of a regex begin with \G, the expression is anchored to the start
3565 match position, and the "anchored" flag is set in the compiled expression.
3566
3567 15. Some bugs concerning the handling of certain option changes within patterns
3568 have been fixed. These applied to options other than (?ims). For example,
3569 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
3570 been the other way round. Some of this was related to change 7 above.
3571
3572 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
3573 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
3574 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
3575 POSIX classes only within a class (e.g. /[[:alpha:]]/).
3576
3577 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
3578 mode. Unlike ".", it always matches newline, whatever the setting of
3579 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
3580 assertions. Perl allows it, but it doesn't (in general) work because it can't
3581 calculate the length of the lookbehind. At least, that's the case for Perl
3582 5.8.0 - I've been told they are going to document that it doesn't work in
3583 future.
3584
3585 18. Added an error diagnosis for escapes that PCRE does not support: these are
3586 \L, \l, \N, \P, \p, \U, \u, and \X.
3587
3588 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
3589 reading past the end of the pattern in cases such as /[abcd/.
3590
3591 20. PCRE was getting more memory than necessary for patterns with classes that
3592 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
3593
3594 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
3595 compiling PCRE for use with Virtual Pascal.
3596
3597 22. Small fix to the Makefile to make it work properly if the build is done
3598 outside the source tree.
3599
3600 23. Added a new extension: a condition to go with recursion. If a conditional
3601 subpattern starts with (?(R) the "true" branch is used if recursion has
3602 happened, whereas the "false" branch is used only at the top level.
3603
3604 24. When there was a very long string of literal characters (over 255 bytes
3605 without UTF support, over 250 bytes with UTF support), the computation of how
3606 much memory was required could be incorrect, leading to segfaults or other
3607 strange effects.
3608
3609 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
3610 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
3611 there was a subsequent back reference to those brackets. This meant that, for
3612 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
3613 possible to check for precisely this case. All we can do is abandon the
3614 optimization if .* occurs inside capturing brackets when there are any back
3615 references whatsoever. (See below for a better fix that came later.)
3616
3617 26. The handling of the optimization for finding the first character of a
3618 non-anchored pattern, and for finding a character that is required later in the
3619 match were failing in some cases. This didn't break the matching; it just
3620 failed to optimize when it could. The way this is done has been re-implemented.
3621
3622 27. Fixed typo in error message for invalid (?R item (it said "(?p").
3623
3624 28. Added a new feature that provides some of the functionality that Perl
3625 provides with (?{...}). The facility is termed a "callout". The way it is done
3626 in PCRE is for the caller to provide an optional function, by setting
3627 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
3628 global variable. By default it is unset, which disables all calling out. To get
3629 the function called, the regex must include (?C) at appropriate points. This
3630 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
3631 This provides a means of identifying different callout points. When PCRE
3632 reaches such a point in the regex, if pcre_callout has been set, the external
3633 function is called. It is provided with data in a structure called
3634 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
3635 matching continues; if it returns a non-zero value, the match at the current
3636 point fails. However, backtracking will occur if possible. [This was changed
3637 later and other features added - see item 49 below.]
3638
3639 29. pcretest is upgraded to test the callout functionality. It provides a
3640 callout function that displays information. By default, it shows the start of
3641 the match and the current position in the text. There are some new data escapes
3642 to vary what happens:
3643
3644 \C+ in addition, show current contents of captured substrings
3645 \C- do not supply a callout function
3646 \C!n return 1 when callout number n is reached
3647 \C!n!m return 1 when callout number n is reached for the mth time
3648
3649 30. If pcregrep was called with the -l option and just a single file name, it
3650 output "<stdin>" if a match was found, instead of the file name.
3651
3652 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
3653 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
3654 pcre_exec(). This saves a malloc/free per call. The default value of
3655 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
3656 when configuring.
3657
3658 32. The default maximum size of a compiled pattern is 64K. There have been a
3659 few cases of people hitting this limit. The code now uses macros to handle the
3660 storing of links as offsets within the compiled pattern. It defaults to 2-byte
3661 links, but this can be changed to 3 or 4 bytes by --with-link-size when
3662 configuring. Tests 2 and 5 work only with 2-byte links because they output
3663 debugging information about compiled patterns.
3664
3665 33. Internal code re-arrangements:
3666
3667 (a) Moved the debugging function for printing out a compiled regex into
3668 its own source file (printint.c) and used #include to pull it into
3669 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
3670 separate copies.
3671
3672 (b) Defined the list of op-code names for debugging as a macro in
3673 internal.h so that it is next to the definition of the opcodes.
3674
3675 (c) Defined a table of op-code lengths for simpler skipping along compiled
3676 code. This is again a macro in internal.h so that it is next to the
3677 definition of the opcodes.
3678
3679 34. Added support for recursive calls to individual subpatterns, along the
3680 lines of Robin Houston's patch (but implemented somewhat differently).
3681
3682 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
3683 allow it to read and process whole directories in Win32. This code was
3684 contributed by Lionel Fourquaux; it has not been tested by me.
3685
3686 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
3687 used to name a group. Names consist of alphanumerics and underscores, and must
3688 be unique. Back references use the syntax (?P=name) and recursive calls use
3689 (?P>name) which is a PCRE extension to the Python extension. Groups still have
3690 numbers. The function pcre_fullinfo() can be used after compilation to extract
3691 a name/number map. There are three relevant calls:
3692
3693 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
3694 PCRE_INFO_NAMECOUNT yields the number of entries
3695 PCRE_INFO_NAMETABLE yields a pointer to the map.
3696
3697 The map is a vector of fixed-size entries. The size of each entry depends on
3698 the length of the longest name used. The first two bytes of each entry are the
3699 group number, most significant byte first. There follows the corresponding
3700 name, zero terminated. The names are in alphabetical order.
3701
3702 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
3703 case instead of 255. Making it the same both with and without UTF-8 support
3704 means that the same test output works with both.
3705
3706 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
3707 calling malloc() with a zero argument.
3708
3709 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
3710 optimization. I've improved things by keeping a bitmap of backreferences with
3711 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
3712 fact referenced, the optimization can be applied. It is unlikely that a
3713 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
3714 the match to follow \n) will appear inside brackets with a number greater than
3715 31, but if it does, any back reference > 31 suppresses the optimization.
3716
3717 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
3718 of disabling numbered capturing parentheses. Any opening parenthesis that is
3719 not followed by ? behaves as if it were followed by ?: but named parentheses
3720 can still be used for capturing (and they will acquire numbers in the usual
3721 way).
3722
3723 41. Redesigned the return codes from the match() function into yes/no/error so
3724 that errors can be passed back from deep inside the nested calls. A malloc
3725 failure while inside a recursive subpattern call now causes the
3726 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
3727
3728 42. It is now possible to set a limit on the number of times the match()
3729 function is called in a call to pcre_exec(). This facility makes it possible to
3730 limit the amount of recursion and backtracking, though not in a directly
3731 obvious way, because the match() function is used in a number of different
3732 circumstances. The count starts from zero for each position in the subject
3733 string (for non-anchored patterns). The default limit is, for compatibility, a
3734 large number, namely 10 000 000. You can change this in two ways:
3735
3736 (a) When configuring PCRE before making, you can use --with-match-limit=n
3737 to set a default value for the compiled library.
3738
3739 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
3740 a different value is set. See 45 below.
3741
3742 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
3743
3744 43. Added a new function pcre_config(int, void *) to enable run-time extraction
3745 of things that can be changed at compile time. The first argument specifies
3746 what is wanted and the second points to where the information is to be placed.
3747 The current list of available information is:
3748
3749 PCRE_CONFIG_UTF8
3750
3751 The output is an integer that is set to one if UTF-8 support is available;
3752 otherwise it is set to zero.
3753
3754 PCRE_CONFIG_NEWLINE
3755
3756 The output is an integer that it set to the value of the code that is used for
3757 newline. It is either LF (10) or CR (13).
3758
3759 PCRE_CONFIG_LINK_SIZE
3760
3761 The output is an integer that contains the number of bytes used for internal
3762 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
3763
3764 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
3765
3766 The output is an integer that contains the threshold above which the POSIX
3767 interface uses malloc() for output vectors. See item 31 above.
3768
3769 PCRE_CONFIG_MATCH_LIMIT
3770
3771 The output is an unsigned integer that contains the default limit of the number
3772 of match() calls in a pcre_exec() execution. See 42 above.
3773
3774 44. pcretest has been upgraded by the addition of the -C option. This causes it
3775 to extract all the available output from the new pcre_config() function, and to
3776 output it. The program then exits immediately.
3777
3778 45. A need has arisen to pass over additional data with calls to pcre_exec() in
3779 order to support additional features. One way would have been to define
3780 pcre_exec2() (for example) with extra arguments, but this would not have been
3781 extensible, and would also have required all calls to the original function to
3782 be mapped to the new one. Instead, I have chosen to extend the mechanism that
3783 is used for passing in "extra" data from pcre_study().
3784
3785 The pcre_extra structure is now exposed and defined in pcre.h. It currently
3786 contains the following fields:
3787
3788 flags a bitmap indicating which of the following fields are set
3789 study_data opaque data from pcre_study()
3790 match_limit a way of specifying a limit on match() calls for a specific
3791 call to pcre_exec()
3792 callout_data data for callouts (see 49 below)
3793
3794 The flag bits are also defined in pcre.h, and are
3795
3796 PCRE_EXTRA_STUDY_DATA
3797 PCRE_EXTRA_MATCH_LIMIT
3798 PCRE_EXTRA_CALLOUT_DATA
3799
3800 The pcre_study() function now returns one of these new pcre_extra blocks, with
3801 the actual study data pointed to by the study_data field, and the
3802 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
3803 before. That is, this change is entirely upwards-compatible and requires no
3804 change to existing code.
3805
3806 If you want to pass in additional data to pcre_exec(), you can either place it
3807 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
3808 block.
3809
3810 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
3811 data string contains the escape sequence \M, pcretest calls pcre_exec() several
3812 times with different match limits, until it finds the minimum value needed for
3813 pcre_exec() to complete. The value is then output. This can be instructive; for
3814 most simple matches the number is quite small, but for pathological cases it
3815 gets very large very quickly.
3816
3817 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
3818 returns the size of the data block pointed to by the study_data field in a
3819 pcre_extra block, that is, the value that was passed as the argument to
3820 pcre_malloc() when PCRE was getting memory in which to place the information
3821 created by pcre_study(). The fourth argument should point to a size_t variable.
3822 pcretest has been extended so that this information is shown after a successful
3823 pcre_study() call when information about the compiled regex is being displayed.
3824
3825 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
3826 because what follows is always an absolute path. (Later: it turns out that this
3827 is more than cosmetic for MinGW, because it doesn't like empty path
3828 components.)
3829
3830 49. Some changes have been made to the callout feature (see 28 above):
3831
3832 (i) A callout function now has three choices for what it returns:
3833
3834 0 => success, carry on matching
3835 > 0 => failure at this point, but backtrack if possible
3836 < 0 => serious error, return this value from pcre_exec()
3837
3838 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
3839 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
3840 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
3841 use by callout functions. It will never be used by PCRE itself.
3842
3843 (ii) The pcre_extra structure (see 45 above) has a void * field called
3844 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
3845 pcre_callout_block structure has a field of the same name. The contents of
3846 the field passed in the pcre_extra structure are passed to the callout
3847 function in the corresponding field in the callout block. This makes it
3848 easier to use the same callout-containing regex from multiple threads. For
3849 testing, the pcretest program has a new data escape
3850
3851 \C*n pass the number n (may be negative) as callout_data
3852
3853 If the callout function in pcretest receives a non-zero value as
3854 callout_data, it returns that value.
3855
3856 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
3857 there were some redundant $(CFLAGS) in commands that are now specified as
3858 $(LINK), which already includes $(CFLAGS).
3859
3860 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
3861 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
3862 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
3863 one-byte characters throughout. Note that case-insensitive matching applies
3864 only to characters whose values are less than 256. PCRE doesn't support the
3865 notion of cases for higher-valued characters.
3866
3867 (i) A character class whose characters are all within 0-255 is handled as
3868 a bit map, and the map is inverted for negative classes. Previously, a
3869 character > 255 always failed to match such a class; however it should
3870 match if the class was a negative one (e.g. [^ab]). This has been fixed.
3871
3872 (ii) A negated character class with a single character < 255 is coded as
3873 "not this character" (OP_NOT). This wasn't working properly when the test
3874 character was multibyte, either singly or repeated.
3875
3876 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
3877 mode, for example: \x{100}{2,3}.
3878
3879 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
3880 singly or repeated) now correctly test multibyte characters. However,
3881 PCRE doesn't recognize any characters with values greater than 255 as
3882 digits, spaces, or word characters. Such characters always match \D, \S,
3883 and \W, and never match \d, \s, or \w.
3884
3885 (v) Classes may now contain characters and character ranges with values
3886 greater than 255. For example: [ab\x{100}-\x{400}].
3887
3888 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
3889 PCRE in UTF-8 mode.
3890
3891 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
3892 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
3893 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
3894 value.)
3895
3896 53. The single man page has become too large. I have therefore split it up into
3897 a number of separate man pages. These also give rise to individual HTML pages;
3898 these are now put in a separate directory, and there is an index.html page that
3899 lists them all. Some hyperlinking between the pages has been installed.
3900
3901 54. Added convenience functions for handling named capturing parentheses.
3902
3903 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
3904 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
3905 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
3906 are faulted.
3907
3908 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
3909 calling configure. These values are used when compiling the dftables.c program
3910 which is run to generate the source of the default character tables. They
3911 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
3912 you will need to set these values.
3913
3914 57. Updated the building process for Windows DLL, as provided by Fred Cox.
3915
3916
3917 Version 3.9 02-Jan-02
3918 ---------------------
3919
3920 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
3921
3922 2. If --disable-static was given, the building process failed when trying to
3923 build pcretest and pcregrep. (For some reason it was using libtool to compile
3924 them, which is not right, as they aren't part of the library.)
3925
3926
3927 Version 3.8 18-Dec-01
3928 ---------------------
3929
3930 1. The experimental UTF-8 code was completely screwed up. It was packing the
3931 bytes in the wrong order. How dumb can you get?
3932
3933
3934 Version 3.7 29-Oct-01
3935 ---------------------
3936
3937 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
3938 This caused pcretest, when used on the test data, to segfault. Unfortunately,
3939 this didn't happen under Solaris 8, where I normally test things.
3940
3941 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
3942 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
3943 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
3944 this fix an hour or so after the initial 3.7 release.)
3945
3946
3947 Version 3.6 23-Oct-01
3948 ---------------------
3949
3950 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
3951 offsets passed as NULL with zero offset count.
3952
3953 2. The config.guess and config.sub files had not been updated when I moved to
3954 the latest autoconf.
3955
3956
3957 Version 3.5 15-Aug-01
3958 ---------------------
3959
3960 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
3961 had been forgotten.
3962
3963 2. By using declared but undefined structures, we can avoid using "void"
3964 definitions in pcre.h while keeping the internal definitions of the structures
3965 private.
3966
3967 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
3968 user point of view, this means that both static and shared libraries are built
3969 by default, but this can be individually controlled. More of the work of
3970 handling this static/shared cases is now inside libtool instead of PCRE's make
3971 file.
3972
3973 4. The pcretest utility is now installed along with pcregrep because it is
3974 useful for users (to test regexs) and by doing this, it automatically gets
3975 relinked by libtool. The documentation has been turned into a man page, so
3976 there are now .1, .txt, and .html versions in /doc.
3977
3978 5. Upgrades to pcregrep:
3979 (i) Added long-form option names like gnu grep.
3980 (ii) Added --help to list all options with an explanatory phrase.
3981 (iii) Added -r, --recursive to recurse into sub-directories.
3982 (iv) Added -f, --file to read patterns from a file.
3983
3984 6. pcre_exec() was referring to its "code" argument before testing that
3985 argument for NULL (and giving an error if it was NULL).
3986
3987 7. Upgraded Makefile.in to allow for compiling in a different directory from
3988 the source directory.
3989
3990 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
3991 options bits, the pointer it was passed was to an int instead of to an unsigned
3992 long int. This mattered only on 64-bit systems.
3993
3994 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
3995 generated) instead of pcre.in, which it its source. Also made the same change
3996 in several of the .c files.
3997
3998 10. A new release of gcc defines printf() as a macro, which broke pcretest
3999 because it had an ifdef in the middle of a string argument for printf(). Fixed
4000 by using separate calls to printf().
4001
4002 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
4003 script, to force use of CR or LF instead of \n in the source. On non-Unix
4004 systems, the value can be set in config.h.
4005
4006 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
4007 absolute limit. Changed the text of the error message to make this clear, and
4008 likewise updated the man page.
4009
4010 13. The limit of 99 on the number of capturing subpatterns has been removed.
4011 The new limit is 65535, which I hope will not be a "real" limit.
4012
4013
4014 Version 3.4 22-Aug-00
4015 ---------------------
4016
4017 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
4018
4019 2. Diagnose condition (?(0) as an error instead of crashing on matching.
4020
4021
4022 Version 3.3 01-Aug-00
4023 ---------------------
4024
4025 1. If an octal character was given, but the value was greater than \377, it
4026 was not getting masked to the least significant bits, as documented. This could
4027 lead to crashes in some systems.
4028
4029 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
4030 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
4031
4032 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
4033 These just pass their arguments on to (pcre_free)(), but they are provided
4034 because some uses of PCRE bind it to non-C systems that can call its functions,
4035 but cannot call free() or pcre_free() directly.
4036
4037 4. Add "make test" as a synonym for "make check". Corrected some comments in
4038 the Makefile.
4039
4040 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
4041 Makefile.
4042
4043 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
4044 command called pgrep for grepping around the active processes.
4045
4046 7. Added the beginnings of support for UTF-8 character strings.
4047
4048 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
4049 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
4050 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
4051 out for the ar command.)
4052
4053
4054 Version 3.2 12-May-00
4055 ---------------------
4056
4057 This is purely a bug fixing release.
4058
4059 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
4060 of ZA. This was just one example of several cases that could provoke this bug,
4061 which was introduced by change 9 of version 2.00. The code for breaking
4062 infinite loops after an iteration that matches an empty string was't working
4063 correctly.
4064
4065 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
4066 when matched against abbab (for example). After matching an empty string, it
4067 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
4068 caused it to match further down the string than it should.
4069
4070 3. The code contained an inclusion of sys/types.h. It isn't clear why this
4071 was there because it doesn't seem to be needed, and it causes trouble on some
4072 systems, as it is not a Standard C header. It has been removed.
4073
4074 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
4075 were reported on the Macintosh. The changes were from
4076
4077 while ((c = *(++ptr)) != 0 && c != '\n');
4078 to
4079 while ((c = *(++ptr)) != 0 && c != '\n') ;
4080
4081 Totally extraordinary, but if that's what it takes...
4082
4083 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
4084 available. Added HAVE_BCOPY and an autoconf test for it; if neither
4085 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
4086 assumes the way PCRE uses memmove() (always moving upwards).
4087
4088 6. PCRE is being used in one environment where strchr() is not available. There
4089 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
4090 faster code anyway.
4091
4092
4093 Version 3.1 09-Feb-00
4094 ---------------------
4095
4096 The only change in this release is the fixing of some bugs in Makefile.in for
4097 the "install" target:
4098
4099 (1) It was failing to install pcreposix.h.
4100
4101 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
4102
4103
4104 Version 3.0 01-Feb-00
4105 ---------------------
4106
4107 1. Add support for the /+ modifier to perltest (to output $` like it does in
4108 pcretest).
4109
4110 2. Add support for the /g modifier to perltest.
4111
4112 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
4113 matches null strings.
4114
4115 4. Fix perltest so that it doesn't do unwanted things when fed an empty
4116 pattern. Perl treats empty patterns specially - it reuses the most recent
4117 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
4118 effect.
4119
4120 5. The POSIX interface was broken in that it was just handing over the POSIX
4121 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
4122 required a bigger vector, with some working space on the end. This means that
4123 the POSIX wrapper now has to get and free some memory, and copy the results.
4124
4125 6. Added some simple autoconf support, placing the test data and the
4126 documentation in separate directories, re-organizing some of the
4127 information files, and making it build pcre-config (a GNU standard). Also added
4128 libtool support for building PCRE as a shared library, which is now the
4129 default.
4130
4131 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
4132 09 are not valid octal constants. Single digits will be used for minor values
4133 less than 10.
4134
4135 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
4136 existing programs that set these in the POSIX interface can use PCRE without
4137 modification.
4138
4139 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
4140 return all that pcre_info() returns, plus additional data. The pcre_info()
4141 function is retained for compatibility, but is considered to be obsolete.
4142
4143 10. Added experimental recursion feature (?R) to handle one common case that
4144 Perl 5.6 will be able to do with (?p{...}).
4145
4146 11. Added support for POSIX character classes like [:alpha:], which Perl is
4147 adopting.
4148
4149
4150 Version 2.08 31-Aug-99
4151 ----------------------
4152
4153 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
4154 trying to match at the startoffset position, but instead was moving forward to
4155 the next newline as if a previous match had failed.
4156
4157 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
4158 and could get into a loop if a null string was matched other than at the start
4159 of the subject.
4160
4161 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
4162 be distinguished at compile time, and for completeness also added PCRE_DATE.
4163
4164 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
4165 in GnuWin32 environments.
4166
4167
4168 Version 2.07 29-Jul-99
4169 ----------------------
4170
4171 1. The documentation is now supplied in plain text form and HTML as well as in
4172 the form of man page sources.
4173
4174 2. C++ compilers don't like assigning (void *) values to other pointer types.
4175 In particular this affects malloc(). Although there is no problem in Standard
4176 C, I've put in casts to keep C++ compilers happy.
4177
4178 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
4179 should be (const char *).
4180
4181 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
4182 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
4183 However, I haven't made this a standard facility. The documentation doesn't
4184 mention it, and the Makefile doesn't support it.
4185
4186 5. The Makefile now contains an "install" target, with editable destinations at
4187 the top of the file. The pcretest program is not installed.
4188
4189 6. pgrep -V now gives the PCRE version number and date.
4190
4191 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
4192 causing the entire string to be ignored, instead of just the last character.
4193
4194 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
4195 non-matching string, it can take a very, very long time, even for strings of
4196 quite modest length, because of the nested recursion. PCRE now does better in
4197 some of these cases. It does this by remembering the last required literal
4198 character in the pattern, and pre-searching the subject to ensure it is present
4199 before running the real match. In other words, it applies a heuristic to detect
4200 some types of certain failure quickly, and in the above example, if presented
4201 with a string that has no trailing " it gives "no match" very quickly.
4202
4203 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
4204 other alternatives are tried instead.
4205
4206
4207 Version 2.06 09-Jun-99
4208 ----------------------
4209
4210 1. Change pcretest's output for amount of store used to show just the code
4211 space, because the remainder (the data block) varies in size between 32-bit and
4212 64-bit systems.
4213
4214 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
4215 start matching at. This allows lookbehinds to work when searching for multiple
4216 occurrences in a string.
4217
4218 3. Added additional options to pcretest for testing multiple occurrences:
4219
4220 /+ outputs the rest of the string that follows a match
4221 /g loops for multiple occurrences, using the new startoffset argument
4222 /G loops for multiple occurrences by passing an incremented pointer
4223
4224 4. PCRE wasn't doing the "first character" optimization for patterns starting
4225 with \b or \B, though it was doing it for other lookbehind assertions. That is,
4226 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
4227 the letter 'x'. On long subject strings, this gives a significant speed-up.
4228
4229
4230 Version 2.05 21-Apr-99
4231 ----------------------
4232
4233 1. Changed the type of magic_number from int to long int so that it works
4234 properly on 16-bit systems.
4235
4236 2. Fixed a bug which caused patterns starting with .* not to work correctly
4237 when the subject string contained newline characters. PCRE was assuming
4238 anchoring for such patterns in all cases, which is not correct because .* will
4239 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
4240 DOTALL is set at top level; otherwise it knows that patterns starting with .*
4241 must be retried after every newline in the subject.
4242
4243
4244 Version 2.04 18-Feb-99
4245 ----------------------
4246
4247 1. For parenthesized subpatterns with repeats whose minimum was zero, the
4248 computation of the store needed to hold the pattern was incorrect (too large).
4249 If such patterns were nested a few deep, this could multiply and become a real
4250 problem.
4251
4252 2. Added /M option to pcretest to show the memory requirement of a specific
4253 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
4254
4255 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
4256 compiled in such a way that the backtracking after subsequent failure was
4257 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
4258 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
4259
4260
4261 Version 2.03 02-Feb-99
4262 ----------------------
4263
4264 1. Fixed typo and small mistake in man page.
4265
4266 2. Added 4th condition (GPL supersedes if conflict) and created separate
4267 LICENCE file containing the conditions.
4268
4269 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
4270 Perl, that is the internal \ allows the delimiter to be included in the
4271 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
4272 the final delimiter, add \ to the end of the pattern (to test the error).
4273
4274 4. Added the convenience functions for extracting substrings after a successful
4275 match. Updated pcretest to make it able to test these functions.
4276
4277
4278 Version 2.02 14-Jan-99
4279 ----------------------
4280
4281 1. Initialized the working variables associated with each extraction so that
4282 their saving and restoring doesn't refer to uninitialized store.
4283
4284 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
4285 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
4286 fix the problem.
4287
4288 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
4289 calls, and wasn't printing the correct value for compiling calls. Increased the
4290 default value of LOOPREPEAT, and the number of significant figures in the
4291 times.
4292
4293 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
4294
4295 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
4296 a building problem on Windows NT with a FAT file system.
4297
4298
4299 Version 2.01 21-Oct-98
4300 ----------------------
4301
4302 1. Changed the API for pcre_compile() to allow for the provision of a pointer
4303 to character tables built by pcre_maketables() in the current locale. If NULL
4304 is passed, the default tables are used.
4305
4306
4307 Version 2.00 24-Sep-98
4308 ----------------------
4309
4310 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
4311 it any more.
4312
4313 2. Allow quantification of (?>) groups, and make it work correctly.
4314
4315 3. The first character computation wasn't working for (?>) groups.
4316
4317 4. Correct the implementation of \Z (it is permitted to match on the \n at the
4318 end of the subject) and add 5.005's \z, which really does match only at the
4319 very end of the subject.
4320
4321 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
4322
4323 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
4324 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
4325 localized options. All options to pcre_study() were also removed.
4326
4327 7. Add other new features from 5.005:
4328
4329 $(?<= positive lookbehind
4330 $(?<! negative lookbehind
4331 (?imsx-imsx) added the unsetting capability
4332 such a setting is global if at outer level; local otherwise
4333 (?imsx-imsx:) non-capturing groups with option setting
4334 (?(cond)re|re) conditional pattern matching
4335
4336 A backreference to itself in a repeated group matches the previous
4337 captured string.
4338
4339 8. General tidying up of studying (both automatic and via "study")
4340 consequential on the addition of new assertions.
4341
4342 9. As in 5.005, unlimited repeated groups that could match an empty substring
4343 are no longer faulted at compile time. Instead, the loop is forcibly broken at
4344 runtime if any iteration does actually match an empty substring.
4345
4346 10. Include the RunTest script in the distribution.
4347
4348 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
4349 discrepancies, some of which were old and were also with respect to 5.004. They
4350 have now been fixed.
4351
4352
4353 Version 1.09 28-Apr-98
4354 ----------------------
4355
4356 1. A negated single character class followed by a quantifier with a minimum
4357 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
4358 program crashes, or just wrong answers. This did not apply to negated classes
4359 containing more than one character, or to minima other than one.
4360
4361
4362 Version 1.08 27-Mar-98
4363 ----------------------
4364
4365 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
4366
4367 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
4368 latter must appear before anything that relies on it in the pattern.
4369
4370
4371 Version 1.07 16-Feb-98
4372 ----------------------
4373
4374 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
4375 repeat of a potentially empty string).
4376
4377
4378 Version 1.06 23-Jan-98
4379 ----------------------
4380
4381 1. Added Markus Oberhumer's little patches for C++.
4382
4383 2. Literal strings longer than 255 characters were broken.
4384
4385
4386 Version 1.05 23-Dec-97
4387 ----------------------
4388
4389 1. Negated character classes containing more than one character were failing if
4390 PCRE_CASELESS was set at run time.
4391
4392
4393 Version 1.04 19-Dec-97
4394 ----------------------
4395
4396 1. Corrected the man page, where some "const" qualifiers had been omitted.
4397
4398 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
4399 input syntax.
4400
4401 3. Fixed memory leak which occurred when a regex with back references was
4402 matched with an offsets vector that wasn't big enough. The temporary memory
4403 that is used in this case wasn't being freed if the match failed.
4404
4405 4. Tidied pcretest to ensure it frees memory that it gets.
4406
4407 5. Temporary memory was being obtained in the case where the passed offsets
4408 vector was exactly big enough.
4409
4410 6. Corrected definition of offsetof() from change 5 below.
4411
4412 7. I had screwed up change 6 below and broken the rules for the use of
4413 setjmp(). Now fixed.
4414
4415
4416 Version 1.03 18-Dec-97
4417 ----------------------
4418
4419 1. A erroneous regex with a missing opening parenthesis was correctly
4420 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
4421 on some systems.
4422
4423 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
4424 it was reported that one broken compiler failed on the former because "code" is
4425 also an independent variable.
4426
4427 3. The erroneous regex a[]b caused an array overrun reference.
4428
4429 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
4430 fail on data ending with that character. (It was going on too far, and checking
4431 the next character, typically a binary zero.) This was specific to the
4432 optimized code for single-character negative classes.
4433
4434 5. Added a contributed patch from the TIN world which does the following:
4435
4436 + Add an undef for memmove, in case the the system defines a macro for it.
4437
4438 + Add a definition of offsetof(), in case there isn't one. (I don't know
4439 the reason behind this - offsetof() is part of the ANSI standard - but
4440 it does no harm).
4441
4442 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
4443 most of the places where whitespace preceded '#'. I have given up and
4444 allowed the remaining 2 cases to be at the margin.
4445
4446 + Rename some variables in pcre to eliminate shadowing. This seems very
4447 pedantic, but does no harm, of course.
4448
4449 6. Moved the call to setjmp() into its own function, to get rid of warnings
4450 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
4451
4452 7. Constructs such as \d{8,} were compiling into the equivalent of
4453 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
4454 outcome, but in this particular case used more store than had been allocated,
4455 which caused the bug to be discovered because it threw up an internal error.
4456
4457 8. The debugging code in both pcre and pcretest for outputting the compiled
4458 form of a regex was going wrong in the case of back references followed by
4459 curly-bracketed repeats.
4460
4461
4462 Version 1.02 12-Dec-97
4463 ----------------------
4464
4465 1. Typos in pcre.3 and comments in the source fixed.
4466
4467 2. Applied a contributed patch to get rid of places where it used to remove
4468 'const' from variables, and fixed some signed/unsigned and uninitialized
4469 variable warnings.
4470
4471 3. Added the "runtest" target to Makefile.
4472
4473 4. Set default compiler flag to -O2 rather than just -O.
4474
4475
4476 Version 1.01 19-Nov-97
4477 ----------------------
4478
4479 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
4480 like /([ab]*)*/, that is, for classes with more than one character in them.
4481
4482 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
4483 as /((?>a*))*/ (a PCRE_EXTRA facility).
4484
4485
4486 Version 1.00 18-Nov-97
4487 ----------------------
4488
4489 1. Added compile-time macros to support systems such as SunOS4 which don't have
4490 memmove() or strerror() but have other things that can be used instead.
4491
4492 2. Arranged that "make clean" removes the executables.
4493
4494
4495 Version 0.99 27-Oct-97
4496 ----------------------
4497
4498 1. Fixed bug in code for optimizing classes with only one character. It was
4499 initializing a 32-byte map regardless, which could cause it to run off the end
4500 of the memory it had got.
4501
4502 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
4503
4504
4505 Version 0.98 22-Oct-97
4506 ----------------------
4507
4508 1. Fixed bug in code for handling temporary memory usage when there are more
4509 back references than supplied space in the ovector. This could cause segfaults.
4510
4511
4512 Version 0.97 21-Oct-97
4513 ----------------------
4514
4515 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
4516
4517 2. Optimized negated single characters not to use a bit map.
4518
4519 3. Brought error texts together as macro definitions; clarified some of them;
4520 fixed one that was wrong - it said "range out of order" when it meant "invalid
4521 escape sequence".
4522
4523 4. Changed some char * arguments to const char *.
4524
4525 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
4526
4527 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
4528 pcretest.
4529
4530
4531 Version 0.96 16-Oct-97
4532 ----------------------
4533
4534 1. Added a simple "pgrep" utility to the distribution.
4535
4536 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
4537 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
4538 where "ddd" means "one or more decimal digits".
4539
4540 3. Fixed serious bug. If a pattern had a back reference, but the call to
4541 pcre_exec() didn't supply a large enough ovector to record the related
4542 identifying subpattern, the match always failed. PCRE now remembers the number
4543 of the largest back reference, and gets some temporary memory in which to save
4544 the offsets during matching if necessary, in order to ensure that
4545 backreferences always work.
4546
4547 4. Increased the compatibility with Perl in a number of ways:
4548
4549 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
4550 to request this handling. The option can be set at compile or exec time.
4551
4552 (b) $ matches before a terminating newline by default; an option
4553 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
4554 mode). The option can be set at compile or exec time.
4555
4556 (c) The handling of \ followed by a digit other than 0 is now supposed to be
4557 the same as Perl's. If the decimal number it represents is less than 10
4558 or there aren't that many previous left capturing parentheses, an octal
4559 escape is read. Inside a character class, it's always an octal escape,
4560 even if it is a single digit.
4561
4562 (d) An escaped but undefined alphabetic character is taken as a literal,
4563 unless PCRE_EXTRA is set. Currently this just reserves the remaining
4564 escapes.
4565
4566 (e) {0} is now permitted. (The previous item is removed from the compiled
4567 pattern).
4568
4569 5. Changed all the names of code files so that the basic parts are no longer
4570 than 10 characters, and abolished the teeny "globals.c" file.
4571
4572 6. Changed the handling of character classes; they are now done with a 32-byte
4573 bit map always.
4574
4575 7. Added the -d and /D options to pcretest to make it possible to look at the
4576 internals of compilation without having to recompile pcre.
4577
4578
4579 Version 0.95 23-Sep-97
4580 ----------------------
4581
4582 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
4583 \x20 at the start of a run of normal characters. These were being treated as
4584 real characters, instead of the source characters being re-checked.
4585
4586
4587 Version 0.94 18-Sep-97
4588 ----------------------
4589
4590 1. The functions are now thread-safe, with the caveat that the global variables
4591 containing pointers to malloc() and free() or alternative functions are the
4592 same for all threads.
4593
4594 2. Get pcre_study() to generate a bitmap of initial characters for non-
4595 anchored patterns when this is possible, and use it if passed to pcre_exec().
4596
4597
4598 Version 0.93 15-Sep-97
4599 ----------------------
4600
4601 1. /(b)|(:+)/ was computing an incorrect first character.
4602
4603 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
4604 but not actually doing anything yet.
4605
4606 3. Treat "-" characters in classes that cannot be part of ranges as literals,
4607 as Perl does (e.g. [-az] or [az-]).
4608
4609 4. Set the anchored flag if a branch starts with .* or .*? because that tests
4610 all possible positions.
4611
4612 5. Split up into different modules to avoid including unneeded functions in a
4613 compiled binary. However, compile and exec are still in one module. The "study"
4614 function is split off.
4615
4616 6. The character tables are now in a separate module whose source is generated
4617 by an auxiliary program - but can then be edited by hand if required. There are
4618 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
4619 toupper() in the code.
4620
4621 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
4622 make them global. Abolish the function for setting them, as the caller can now
4623 set them directly.
4624
4625
4626 Version 0.92 11-Sep-97
4627 ----------------------
4628
4629 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
4630 (e.g. /a{1,3}/) was broken (I mis-optimized it).
4631
4632 2. Caseless matching was not working in character classes if the characters in
4633 the pattern were in upper case.
4634
4635 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
4636
4637 4. Make PCRE_ANCHORED public and accept as a compile option.
4638
4639 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
4640 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
4641 pass them.
4642
4643 6. Give an error if bad option bits passed at compile or run time.
4644
4645 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
4646 pcretest to cause it to pass that flag.
4647
4648 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
4649 options, and the first character, if set.
4650
4651 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
4652
4653
4654 Version 0.91 10-Sep-97
4655 ----------------------
4656
4657 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
4658 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
4659
4660 2. PCRE was looping on encountering an indefinitely repeated back reference to
4661 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
4662 Perl does - treats the match as successful.
4663
4664 ****

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