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Revision 1594 - (show annotations)
Fri Aug 21 16:08:33 2015 UTC (4 years, 5 months ago) by ph10
File size: 283862 byte(s)
Hack in yet other patch for a bug in size computation that is fixed "properly" 
in PCRE2.
1 ChangeLog for PCRE
2 ------------------
3
4 Note that the PCRE 8.xx series (PCRE1) is now in a bugfix-only state. All
5 development is happening in the PCRE2 10.xx series.
6
7 Version 8.38 xx-xxx-xxxx
8 ------------------------
9
10 1. If a group that contained a recursive back reference also contained a
11 forward reference subroutine call followed by a non-forward-reference
12 subroutine call, for example /.((?2)(?R)\1)()/, pcre2_compile() failed to
13 compile correct code, leading to undefined behaviour or an internally
14 detected error. This bug was discovered by the LLVM fuzzer.
15
16 2. Quantification of certain items (e.g. atomic back references) could cause
17 incorrect code to be compiled when recursive forward references were
18 involved. For example, in this pattern: /(?1)()((((((\1++))\x85)+)|))/.
19 This bug was discovered by the LLVM fuzzer.
20
21 3. A repeated conditional group whose condition was a reference by name caused
22 a buffer overflow if there was more than one group with the given name.
23 This bug was discovered by the LLVM fuzzer.
24
25 4. A recursive back reference by name within a group that had the same name as
26 another group caused a buffer overflow. For example:
27 /(?J)(?'d'(?'d'\g{d}))/. This bug was discovered by the LLVM fuzzer.
28
29 5. A forward reference by name to a group whose number is the same as the
30 current group, for example in this pattern: /(?|(\k'Pm')|(?'Pm'))/, caused
31 a buffer overflow at compile time. This bug was discovered by the LLVM
32 fuzzer.
33
34 6. A lookbehind assertion within a set of mutually recursive subpatterns could
35 provoke a buffer overflow. This bug was discovered by the LLVM fuzzer.
36
37 7. Another buffer overflow bug involved duplicate named groups with a
38 reference between their definition, with a group that reset capture
39 numbers, for example: /(?J:(?|(?'R')(\k'R')|((?'R'))))/. This has been
40 fixed by always allowing for more memory, even if not needed. (A proper fix
41 is implemented in PCRE2, but it involves more refactoring.)
42
43 8. There was no check for integer overflow in subroutine calls such as (?123).
44
45 9. The table entry for \l in EBCDIC environments was incorrect, leading to its
46 being treated as a literal 'l' instead of causing an error.
47
48 10. There was a buffer overflow if pcre_exec() was called with an ovector of
49 size 1. This bug was found by american fuzzy lop.
50
51 11. If a non-capturing group containing a conditional group that could match
52 an empty string was repeated, it was not identified as matching an empty
53 string itself. For example: /^(?:(?(1)x|)+)+$()/.
54
55 12. In an EBCDIC environment, pcretest was mishandling the escape sequences
56 \a and \e in test subject lines.
57
58 13. In an EBCDIC environment, \a in a pattern was converted to the ASCII
59 instead of the EBCDIC value.
60
61 14. The handling of \c in an EBCDIC environment has been revised so that it is
62 now compatible with the specification in Perl's perlebcdic page.
63
64 15. The EBCDIC character 0x41 is a non-breaking space, equivalent to 0xa0 in
65 ASCII/Unicode. This has now been added to the list of characters that are
66 recognized as white space in EBCDIC.
67
68 16. When PCRE was compiled without UCP support, the use of \p and \P gave an
69 error (correctly) when used outside a class, but did not give an error
70 within a class.
71
72 17. \h within a class was incorrectly compiled in EBCDIC environments.
73
74 18. A pattern with an unmatched closing parenthesis that contained a backward
75 assertion which itself contained a forward reference caused buffer
76 overflow. And example pattern is: /(?=di(?<=(?1))|(?=(.))))/.
77
78 19. JIT should return with error when the compiled pattern requires more stack
79 space than the maximum.
80
81 20. A possessively repeated conditional group that could match an empty string,
82 for example, /(?(R))*+/, was incorrectly compiled.
83
84 21. Fix infinite recursion in the JIT compiler when certain patterns such as
85 /(?:|a|){100}x/ are analysed.
86
87 22. Some patterns with character classes involving [: and \\ were incorrectly
88 compiled and could cause reading from uninitialized memory or an incorrect
89 error diagnosis.
90
91 23. Pathological patterns containing many nested occurrences of [: caused
92 pcre_compile() to run for a very long time.
93
94 24. A conditional group with only one branch has an implicit empty alternative
95 branch and must therefore be treated as potentially matching an empty
96 string.
97
98 25. If (?R was followed by - or + incorrect behaviour happened instead of a
99 diagnostic.
100
101 26. Arrange to give up on finding the minimum matching length for overly
102 complex patterns.
103
104 27. Similar to (4) above: in a pattern with duplicated named groups and an
105 occurrence of (?| it is possible for an apparently non-recursive back
106 reference to become recursive if a later named group with the relevant
107 number is encountered. This could lead to a buffer overflow. Wen Guanxing
108 from Venustech ADLAB discovered this bug.
109
110 28. If pcregrep was given the -q option with -c or -l, or when handling a
111 binary file, it incorrectly wrote output to stdout.
112
113 29. The JIT compiler did not restore the control verb head in case of *THEN
114 control verbs. This issue was found by Karl Skomski with a custom LLVM
115 fuzzer.
116
117 30. Error messages for syntax errors following \g and \k were giving inaccurate
118 offsets in the pattern.
119
120 31. Added a check for integer overflow in conditions (?(<digits>) and
121 (?(R<digits>). This omission was discovered by Karl Skomski with the LLVM
122 fuzzer.
123
124 32. Handling recursive references such as (?2) when the reference is to a group
125 later in the pattern uses code that is very hacked about and error-prone.
126 It has been re-written for PCRE2. Here in PCRE1, a check has been added to
127 give an internal error if it is obvious that compiling has gone wrong.
128
129 33. The JIT compiler should not check repeats after a {0,1} repeat byte code.
130 This issue was found by Karl Skomski with a custom LLVM fuzzer.
131
132 34. The JIT compiler should restore the control chain for empty possessive
133 repeats. This issue was found by Karl Skomski with a custom LLVM fuzzer.
134
135 35. Match limit check added to JIT recursion. This issue was found by Karl
136 Skomski with a custom LLVM fuzzer.
137
138 36. Yet another case similar to 27 above has been circumvented by an
139 unconditional allocation of extra memory. This issue is fixed "properly" in
140 PCRE2 by refactoring the way references are handled. Wen Guanxing
141 from Venustech ADLAB discovered this bug.
142
143
144 Version 8.37 28-April-2015
145 --------------------------
146
147 1. When an (*ACCEPT) is triggered inside capturing parentheses, it arranges
148 for those parentheses to be closed with whatever has been captured so far.
149 However, it was failing to mark any other groups between the hightest
150 capture so far and the currrent group as "unset". Thus, the ovector for
151 those groups contained whatever was previously there. An example is the
152 pattern /(x)|((*ACCEPT))/ when matched against "abcd".
153
154 2. If an assertion condition was quantified with a minimum of zero (an odd
155 thing to do, but it happened), SIGSEGV or other misbehaviour could occur.
156
157 3. If a pattern in pcretest input had the P (POSIX) modifier followed by an
158 unrecognized modifier, a crash could occur.
159
160 4. An attempt to do global matching in pcretest with a zero-length ovector
161 caused a crash.
162
163 5. Fixed a memory leak during matching that could occur for a subpattern
164 subroutine call (recursive or otherwise) if the number of captured groups
165 that had to be saved was greater than ten.
166
167 6. Catch a bad opcode during auto-possessification after compiling a bad UTF
168 string with NO_UTF_CHECK. This is a tidyup, not a bug fix, as passing bad
169 UTF with NO_UTF_CHECK is documented as having an undefined outcome.
170
171 7. A UTF pattern containing a "not" match of a non-ASCII character and a
172 subroutine reference could loop at compile time. Example: /[^\xff]((?1))/.
173
174 8. When a pattern is compiled, it remembers the highest back reference so that
175 when matching, if the ovector is too small, extra memory can be obtained to
176 use instead. A conditional subpattern whose condition is a check on a
177 capture having happened, such as, for example in the pattern
178 /^(?:(a)|b)(?(1)A|B)/, is another kind of back reference, but it was not
179 setting the highest backreference number. This mattered only if pcre_exec()
180 was called with an ovector that was too small to hold the capture, and there
181 was no other kind of back reference (a situation which is probably quite
182 rare). The effect of the bug was that the condition was always treated as
183 FALSE when the capture could not be consulted, leading to a incorrect
184 behaviour by pcre_exec(). This bug has been fixed.
185
186 9. A reference to a duplicated named group (either a back reference or a test
187 for being set in a conditional) that occurred in a part of the pattern where
188 PCRE_DUPNAMES was not set caused the amount of memory needed for the pattern
189 to be incorrectly calculated, leading to overwriting.
190
191 10. A mutually recursive set of back references such as (\2)(\1) caused a
192 segfault at study time (while trying to find the minimum matching length).
193 The infinite loop is now broken (with the minimum length unset, that is,
194 zero).
195
196 11. If an assertion that was used as a condition was quantified with a minimum
197 of zero, matching went wrong. In particular, if the whole group had
198 unlimited repetition and could match an empty string, a segfault was
199 likely. The pattern (?(?=0)?)+ is an example that caused this. Perl allows
200 assertions to be quantified, but not if they are being used as conditions,
201 so the above pattern is faulted by Perl. PCRE has now been changed so that
202 it also rejects such patterns.
203
204 12. A possessive capturing group such as (a)*+ with a minimum repeat of zero
205 failed to allow the zero-repeat case if pcre2_exec() was called with an
206 ovector too small to capture the group.
207
208 13. Fixed two bugs in pcretest that were discovered by fuzzing and reported by
209 Red Hat Product Security:
210
211 (a) A crash if /K and /F were both set with the option to save the compiled
212 pattern.
213
214 (b) Another crash if the option to print captured substrings in a callout
215 was combined with setting a null ovector, for example \O\C+ as a subject
216 string.
217
218 14. A pattern such as "((?2){0,1999}())?", which has a group containing a
219 forward reference repeated a large (but limited) number of times within a
220 repeated outer group that has a zero minimum quantifier, caused incorrect
221 code to be compiled, leading to the error "internal error:
222 previously-checked referenced subpattern not found" when an incorrect
223 memory address was read. This bug was reported as "heap overflow",
224 discovered by Kai Lu of Fortinet's FortiGuard Labs and given the CVE number
225 CVE-2015-2325.
226
227 23. A pattern such as "((?+1)(\1))/" containing a forward reference subroutine
228 call within a group that also contained a recursive back reference caused
229 incorrect code to be compiled. This bug was reported as "heap overflow",
230 discovered by Kai Lu of Fortinet's FortiGuard Labs, and given the CVE
231 number CVE-2015-2326.
232
233 24. Computing the size of the JIT read-only data in advance has been a source
234 of various issues, and new ones are still appear unfortunately. To fix
235 existing and future issues, size computation is eliminated from the code,
236 and replaced by on-demand memory allocation.
237
238 25. A pattern such as /(?i)[A-`]/, where characters in the other case are
239 adjacent to the end of the range, and the range contained characters with
240 more than one other case, caused incorrect behaviour when compiled in UTF
241 mode. In that example, the range a-j was left out of the class.
242
243 26. Fix JIT compilation of conditional blocks, which assertion
244 is converted to (*FAIL). E.g: /(?(?!))/.
245
246 27. The pattern /(?(?!)^)/ caused references to random memory. This bug was
247 discovered by the LLVM fuzzer.
248
249 28. The assertion (?!) is optimized to (*FAIL). This was not handled correctly
250 when this assertion was used as a condition, for example (?(?!)a|b). In
251 pcre2_match() it worked by luck; in pcre2_dfa_match() it gave an incorrect
252 error about an unsupported item.
253
254 29. For some types of pattern, for example /Z*(|d*){216}/, the auto-
255 possessification code could take exponential time to complete. A recursion
256 depth limit of 1000 has been imposed to limit the resources used by this
257 optimization.
258
259 30. A pattern such as /(*UTF)[\S\V\H]/, which contains a negated special class
260 such as \S in non-UCP mode, explicit wide characters (> 255) can be ignored
261 because \S ensures they are all in the class. The code for doing this was
262 interacting badly with the code for computing the amount of space needed to
263 compile the pattern, leading to a buffer overflow. This bug was discovered
264 by the LLVM fuzzer.
265
266 31. A pattern such as /((?2)+)((?1))/ which has mutual recursion nested inside
267 other kinds of group caused stack overflow at compile time. This bug was
268 discovered by the LLVM fuzzer.
269
270 32. A pattern such as /(?1)(?#?'){8}(a)/ which had a parenthesized comment
271 between a subroutine call and its quantifier was incorrectly compiled,
272 leading to buffer overflow or other errors. This bug was discovered by the
273 LLVM fuzzer.
274
275 33. The illegal pattern /(?(?<E>.*!.*)?)/ was not being diagnosed as missing an
276 assertion after (?(. The code was failing to check the character after
277 (?(?< for the ! or = that would indicate a lookbehind assertion. This bug
278 was discovered by the LLVM fuzzer.
279
280 34. A pattern such as /X((?2)()*+){2}+/ which has a possessive quantifier with
281 a fixed maximum following a group that contains a subroutine reference was
282 incorrectly compiled and could trigger buffer overflow. This bug was
283 discovered by the LLVM fuzzer.
284
285 35. A mutual recursion within a lookbehind assertion such as (?<=((?2))((?1)))
286 caused a stack overflow instead of the diagnosis of a non-fixed length
287 lookbehind assertion. This bug was discovered by the LLVM fuzzer.
288
289 36. The use of \K in a positive lookbehind assertion in a non-anchored pattern
290 (e.g. /(?<=\Ka)/) could make pcregrep loop.
291
292 37. There was a similar problem to 36 in pcretest for global matches.
293
294 38. If a greedy quantified \X was preceded by \C in UTF mode (e.g. \C\X*),
295 and a subsequent item in the pattern caused a non-match, backtracking over
296 the repeated \X did not stop, but carried on past the start of the subject,
297 causing reference to random memory and/or a segfault. There were also some
298 other cases where backtracking after \C could crash. This set of bugs was
299 discovered by the LLVM fuzzer.
300
301 39. The function for finding the minimum length of a matching string could take
302 a very long time if mutual recursion was present many times in a pattern,
303 for example, /((?2){73}(?2))((?1))/. A better mutual recursion detection
304 method has been implemented. This infelicity was discovered by the LLVM
305 fuzzer.
306
307 40. Static linking against the PCRE library using the pkg-config module was
308 failing on missing pthread symbols.
309
310
311 Version 8.36 26-September-2014
312 ------------------------------
313
314 1. Got rid of some compiler warnings in the C++ modules that were shown up by
315 -Wmissing-field-initializers and -Wunused-parameter.
316
317 2. The tests for quantifiers being too big (greater than 65535) were being
318 applied after reading the number, and stupidly assuming that integer
319 overflow would give a negative number. The tests are now applied as the
320 numbers are read.
321
322 3. Tidy code in pcre_exec.c where two branches that used to be different are
323 now the same.
324
325 4. The JIT compiler did not generate match limit checks for certain
326 bracketed expressions with quantifiers. This may lead to exponential
327 backtracking, instead of returning with PCRE_ERROR_MATCHLIMIT. This
328 issue should be resolved now.
329
330 5. Fixed an issue, which occures when nested alternatives are optimized
331 with table jumps.
332
333 6. Inserted two casts and changed some ints to size_t in the light of some
334 reported 64-bit compiler warnings (Bugzilla 1477).
335
336 7. Fixed a bug concerned with zero-minimum possessive groups that could match
337 an empty string, which sometimes were behaving incorrectly in the
338 interpreter (though correctly in the JIT matcher). This pcretest input is
339 an example:
340
341 '\A(?:[^"]++|"(?:[^"]*+|"")*+")++'
342 NON QUOTED "QUOT""ED" AFTER "NOT MATCHED
343
344 the interpreter was reporting a match of 'NON QUOTED ' only, whereas the
345 JIT matcher and Perl both matched 'NON QUOTED "QUOT""ED" AFTER '. The test
346 for an empty string was breaking the inner loop and carrying on at a lower
347 level, when possessive repeated groups should always return to a higher
348 level as they have no backtrack points in them. The empty string test now
349 occurs at the outer level.
350
351 8. Fixed a bug that was incorrectly auto-possessifying \w+ in the pattern
352 ^\w+(?>\s*)(?<=\w) which caused it not to match "test test".
353
354 9. Give a compile-time error for \o{} (as Perl does) and for \x{} (which Perl
355 doesn't).
356
357 10. Change 8.34/15 introduced a bug that caused the amount of memory needed
358 to hold a pattern to be incorrectly computed (too small) when there were
359 named back references to duplicated names. This could cause "internal
360 error: code overflow" or "double free or corruption" or other memory
361 handling errors.
362
363 11. When named subpatterns had the same prefixes, back references could be
364 confused. For example, in this pattern:
365
366 /(?P<Name>a)?(?P<Name2>b)?(?(<Name>)c|d)*l/
367
368 the reference to 'Name' was incorrectly treated as a reference to a
369 duplicate name.
370
371 12. A pattern such as /^s?c/mi8 where the optional character has more than
372 one "other case" was incorrectly compiled such that it would only try to
373 match starting at "c".
374
375 13. When a pattern starting with \s was studied, VT was not included in the
376 list of possible starting characters; this should have been part of the
377 8.34/18 patch.
378
379 14. If a character class started [\Qx]... where x is any character, the class
380 was incorrectly terminated at the ].
381
382 15. If a pattern that started with a caseless match for a character with more
383 than one "other case" was studied, PCRE did not set up the starting code
384 unit bit map for the list of possible characters. Now it does. This is an
385 optimization improvement, not a bug fix.
386
387 16. The Unicode data tables have been updated to Unicode 7.0.0.
388
389 17. Fixed a number of memory leaks in pcregrep.
390
391 18. Avoid a compiler warning (from some compilers) for a function call with
392 a cast that removes "const" from an lvalue by using an intermediate
393 variable (to which the compiler does not object).
394
395 19. Incorrect code was compiled if a group that contained an internal recursive
396 back reference was optional (had quantifier with a minimum of zero). This
397 example compiled incorrect code: /(((a\2)|(a*)\g<-1>))*/ and other examples
398 caused segmentation faults because of stack overflows at compile time.
399
400 20. A pattern such as /((?(R)a|(?1)))+/, which contains a recursion within a
401 group that is quantified with an indefinite repeat, caused a compile-time
402 loop which used up all the system stack and provoked a segmentation fault.
403 This was not the same bug as 19 above.
404
405 21. Add PCRECPP_EXP_DECL declaration to operator<< in pcre_stringpiece.h.
406 Patch by Mike Frysinger.
407
408
409 Version 8.35 04-April-2014
410 --------------------------
411
412 1. A new flag is set, when property checks are present in an XCLASS.
413 When this flag is not set, PCRE can perform certain optimizations
414 such as studying these XCLASS-es.
415
416 2. The auto-possessification of character sets were improved: a normal
417 and an extended character set can be compared now. Furthermore
418 the JIT compiler optimizes more character set checks.
419
420 3. Got rid of some compiler warnings for potentially uninitialized variables
421 that show up only when compiled with -O2.
422
423 4. A pattern such as (?=ab\K) that uses \K in an assertion can set the start
424 of a match later then the end of the match. The pcretest program was not
425 handling the case sensibly - it was outputting from the start to the next
426 binary zero. It now reports this situation in a message, and outputs the
427 text from the end to the start.
428
429 5. Fast forward search is improved in JIT. Instead of the first three
430 characters, any three characters with fixed position can be searched.
431 Search order: first, last, middle.
432
433 6. Improve character range checks in JIT. Characters are read by an inprecise
434 function now, which returns with an unknown value if the character code is
435 above a certain threshold (e.g: 256). The only limitation is that the value
436 must be bigger than the threshold as well. This function is useful when
437 the characters above the threshold are handled in the same way.
438
439 7. The macros whose names start with RAWUCHAR are placeholders for a future
440 mode in which only the bottom 21 bits of 32-bit data items are used. To
441 make this more memorable for those maintaining the code, the names have
442 been changed to start with UCHAR21, and an extensive comment has been added
443 to their definition.
444
445 8. Add missing (new) files sljitNativeTILEGX.c and sljitNativeTILEGX-encoder.c
446 to the export list in Makefile.am (they were accidentally omitted from the
447 8.34 tarball).
448
449 9. The informational output from pcretest used the phrase "starting byte set"
450 which is inappropriate for the 16-bit and 32-bit libraries. As the output
451 for "first char" and "need char" really means "non-UTF-char", I've changed
452 "byte" to "char", and slightly reworded the output. The documentation about
453 these values has also been (I hope) clarified.
454
455 10. Another JIT related optimization: use table jumps for selecting the correct
456 backtracking path, when more than four alternatives are present inside a
457 bracket.
458
459 11. Empty match is not possible, when the minimum length is greater than zero,
460 and there is no \K in the pattern. JIT should avoid empty match checks in
461 such cases.
462
463 12. In a caseless character class with UCP support, when a character with more
464 than one alternative case was not the first character of a range, not all
465 the alternative cases were added to the class. For example, s and \x{17f}
466 are both alternative cases for S: the class [RST] was handled correctly,
467 but [R-T] was not.
468
469 13. The configure.ac file always checked for pthread support when JIT was
470 enabled. This is not used in Windows, so I have put this test inside a
471 check for the presence of windows.h (which was already tested for).
472
473 14. Improve pattern prefix search by a simplified Boyer-Moore algorithm in JIT.
474 The algorithm provides a way to skip certain starting offsets, and usually
475 faster than linear prefix searches.
476
477 15. Change 13 for 8.20 updated RunTest to check for the 'fr' locale as well
478 as for 'fr_FR' and 'french'. For some reason, however, it then used the
479 Windows-specific input and output files, which have 'french' screwed in.
480 So this could never have worked. One of the problems with locales is that
481 they aren't always the same. I have now updated RunTest so that it checks
482 the output of the locale test (test 3) against three different output
483 files, and it allows the test to pass if any one of them matches. With luck
484 this should make the test pass on some versions of Solaris where it was
485 failing. Because of the uncertainty, the script did not used to stop if
486 test 3 failed; it now does. If further versions of a French locale ever
487 come to light, they can now easily be added.
488
489 16. If --with-pcregrep-bufsize was given a non-integer value such as "50K",
490 there was a message during ./configure, but it did not stop. This now
491 provokes an error. The invalid example in README has been corrected.
492 If a value less than the minimum is given, the minimum value has always
493 been used, but now a warning is given.
494
495 17. If --enable-bsr-anycrlf was set, the special 16/32-bit test failed. This
496 was a bug in the test system, which is now fixed. Also, the list of various
497 configurations that are tested for each release did not have one with both
498 16/32 bits and --enable-bar-anycrlf. It now does.
499
500 18. pcretest was missing "-C bsr" for displaying the \R default setting.
501
502 19. Little endian PowerPC systems are supported now by the JIT compiler.
503
504 20. The fast forward newline mechanism could enter to an infinite loop on
505 certain invalid UTF-8 input. Although we don't support these cases
506 this issue can be fixed by a performance optimization.
507
508 21. Change 33 of 8.34 is not sufficient to ensure stack safety because it does
509 not take account if existing stack usage. There is now a new global
510 variable called pcre_stack_guard that can be set to point to an external
511 function to check stack availability. It is called at the start of
512 processing every parenthesized group.
513
514 22. A typo in the code meant that in ungreedy mode the max/min qualifier
515 behaved like a min-possessive qualifier, and, for example, /a{1,3}b/U did
516 not match "ab".
517
518 23. When UTF was disabled, the JIT program reported some incorrect compile
519 errors. These messages are silenced now.
520
521 24. Experimental support for ARM-64 and MIPS-64 has been added to the JIT
522 compiler.
523
524 25. Change all the temporary files used in RunGrepTest to be different to those
525 used by RunTest so that the tests can be run simultaneously, for example by
526 "make -j check".
527
528
529 Version 8.34 15-December-2013
530 -----------------------------
531
532 1. Add pcre[16|32]_jit_free_unused_memory to forcibly free unused JIT
533 executable memory. Patch inspired by Carsten Klein.
534
535 2. ./configure --enable-coverage defined SUPPORT_GCOV in config.h, although
536 this macro is never tested and has no effect, because the work to support
537 coverage involves only compiling and linking options and special targets in
538 the Makefile. The comment in config.h implied that defining the macro would
539 enable coverage support, which is totally false. There was also support for
540 setting this macro in the CMake files (my fault, I just copied it from
541 configure). SUPPORT_GCOV has now been removed.
542
543 3. Make a small performance improvement in strlen16() and strlen32() in
544 pcretest.
545
546 4. Change 36 for 8.33 left some unreachable statements in pcre_exec.c,
547 detected by the Solaris compiler (gcc doesn't seem to be able to diagnose
548 these cases). There was also one in pcretest.c.
549
550 5. Cleaned up a "may be uninitialized" compiler warning in pcre_exec.c.
551
552 6. In UTF mode, the code for checking whether a group could match an empty
553 string (which is used for indefinitely repeated groups to allow for
554 breaking an infinite loop) was broken when the group contained a repeated
555 negated single-character class with a character that occupied more than one
556 data item and had a minimum repetition of zero (for example, [^\x{100}]* in
557 UTF-8 mode). The effect was undefined: the group might or might not be
558 deemed as matching an empty string, or the program might have crashed.
559
560 7. The code for checking whether a group could match an empty string was not
561 recognizing that \h, \H, \v, \V, and \R must match a character.
562
563 8. Implemented PCRE_INFO_MATCH_EMPTY, which yields 1 if the pattern can match
564 an empty string. If it can, pcretest shows this in its information output.
565
566 9. Fixed two related bugs that applied to Unicode extended grapheme clusters
567 that were repeated with a maximizing qualifier (e.g. \X* or \X{2,5}) when
568 matched by pcre_exec() without using JIT:
569
570 (a) If the rest of the pattern did not match after a maximal run of
571 grapheme clusters, the code for backing up to try with fewer of them
572 did not always back up over a full grapheme when characters that do not
573 have the modifier quality were involved, e.g. Hangul syllables.
574
575 (b) If the match point in a subject started with modifier character, and
576 there was no match, the code could incorrectly back up beyond the match
577 point, and potentially beyond the first character in the subject,
578 leading to a segfault or an incorrect match result.
579
580 10. A conditional group with an assertion condition could lead to PCRE
581 recording an incorrect first data item for a match if no other first data
582 item was recorded. For example, the pattern (?(?=ab)ab) recorded "a" as a
583 first data item, and therefore matched "ca" after "c" instead of at the
584 start.
585
586 11. Change 40 for 8.33 (allowing pcregrep to find empty strings) showed up a
587 bug that caused the command "echo a | ./pcregrep -M '|a'" to loop.
588
589 12. The source of pcregrep now includes z/OS-specific code so that it can be
590 compiled for z/OS as part of the special z/OS distribution.
591
592 13. Added the -T and -TM options to pcretest.
593
594 14. The code in pcre_compile.c for creating the table of named capturing groups
595 has been refactored. Instead of creating the table dynamically during the
596 actual compiling pass, the information is remembered during the pre-compile
597 pass (on the stack unless there are more than 20 named groups, in which
598 case malloc() is used) and the whole table is created before the actual
599 compile happens. This has simplified the code (it is now nearly 150 lines
600 shorter) and prepared the way for better handling of references to groups
601 with duplicate names.
602
603 15. A back reference to a named subpattern when there is more than one of the
604 same name now checks them in the order in which they appear in the pattern.
605 The first one that is set is used for the reference. Previously only the
606 first one was inspected. This change makes PCRE more compatible with Perl.
607
608 16. Unicode character properties were updated from Unicode 6.3.0.
609
610 17. The compile-time code for auto-possessification has been refactored, based
611 on a patch by Zoltan Herczeg. It now happens after instead of during
612 compilation. The code is cleaner, and more cases are handled. The option
613 PCRE_NO_AUTO_POSSESS is added for testing purposes, and the -O and /O
614 options in pcretest are provided to set it. It can also be set by
615 (*NO_AUTO_POSSESS) at the start of a pattern.
616
617 18. The character VT has been added to the default ("C" locale) set of
618 characters that match \s and are generally treated as white space,
619 following this same change in Perl 5.18. There is now no difference between
620 "Perl space" and "POSIX space". Whether VT is treated as white space in
621 other locales depends on the locale.
622
623 19. The code for checking named groups as conditions, either for being set or
624 for being recursed, has been refactored (this is related to 14 and 15
625 above). Processing unduplicated named groups should now be as fast at
626 numerical groups, and processing duplicated groups should be faster than
627 before.
628
629 20. Two patches to the CMake build system, by Alexander Barkov:
630
631 (1) Replace the "source" command by "." in CMakeLists.txt because
632 "source" is a bash-ism.
633
634 (2) Add missing HAVE_STDINT_H and HAVE_INTTYPES_H to config-cmake.h.in;
635 without these the CMake build does not work on Solaris.
636
637 21. Perl has changed its handling of \8 and \9. If there is no previously
638 encountered capturing group of those numbers, they are treated as the
639 literal characters 8 and 9 instead of a binary zero followed by the
640 literals. PCRE now does the same.
641
642 22. Following Perl, added \o{} to specify codepoints in octal, making it
643 possible to specify values greater than 0777 and also making them
644 unambiguous.
645
646 23. Perl now gives an error for missing closing braces after \x{... instead of
647 treating the string as literal. PCRE now does the same.
648
649 24. RunTest used to grumble if an inappropriate test was selected explicitly,
650 but just skip it when running all tests. This make it awkward to run ranges
651 of tests when one of them was inappropriate. Now it just skips any
652 inappropriate tests, as it always did when running all tests.
653
654 25. If PCRE_AUTO_CALLOUT and PCRE_UCP were set for a pattern that contained
655 character types such as \d or \w, too many callouts were inserted, and the
656 data that they returned was rubbish.
657
658 26. In UCP mode, \s was not matching two of the characters that Perl matches,
659 namely NEL (U+0085) and MONGOLIAN VOWEL SEPARATOR (U+180E), though they
660 were matched by \h. The code has now been refactored so that the lists of
661 the horizontal and vertical whitespace characters used for \h and \v (which
662 are defined only in one place) are now also used for \s.
663
664 27. Add JIT support for the 64 bit TileGX architecture.
665 Patch by Jiong Wang (Tilera Corporation).
666
667 28. Possessive quantifiers for classes (both explicit and automatically
668 generated) now use special opcodes instead of wrapping in ONCE brackets.
669
670 29. Whereas an item such as A{4}+ ignored the possessivenes of the quantifier
671 (because it's meaningless), this was not happening when PCRE_CASELESS was
672 set. Not wrong, but inefficient.
673
674 30. Updated perltest.pl to add /u (force Unicode mode) when /W (use Unicode
675 properties for \w, \d, etc) is present in a test regex. Otherwise if the
676 test contains no characters greater than 255, Perl doesn't realise it
677 should be using Unicode semantics.
678
679 31. Upgraded the handling of the POSIX classes [:graph:], [:print:], and
680 [:punct:] when PCRE_UCP is set so as to include the same characters as Perl
681 does in Unicode mode.
682
683 32. Added the "forbid" facility to pcretest so that putting tests into the
684 wrong test files can sometimes be quickly detected.
685
686 33. There is now a limit (default 250) on the depth of nesting of parentheses.
687 This limit is imposed to control the amount of system stack used at compile
688 time. It can be changed at build time by --with-parens-nest-limit=xxx or
689 the equivalent in CMake.
690
691 34. Character classes such as [A-\d] or [a-[:digit:]] now cause compile-time
692 errors. Perl warns for these when in warning mode, but PCRE has no facility
693 for giving warnings.
694
695 35. Change 34 for 8.13 allowed quantifiers on assertions, because Perl does.
696 However, this was not working for (?!) because it is optimized to (*FAIL),
697 for which PCRE does not allow quantifiers. The optimization is now disabled
698 when a quantifier follows (?!). I can't see any use for this, but it makes
699 things uniform.
700
701 36. Perl no longer allows group names to start with digits, so I have made this
702 change also in PCRE. It simplifies the code a bit.
703
704 37. In extended mode, Perl ignores spaces before a + that indicates a
705 possessive quantifier. PCRE allowed a space before the quantifier, but not
706 before the possessive +. It now does.
707
708 38. The use of \K (reset reported match start) within a repeated possessive
709 group such as (a\Kb)*+ was not working.
710
711 40. Document that the same character tables must be used at compile time and
712 run time, and that the facility to pass tables to pcre_exec() and
713 pcre_dfa_exec() is for use only with saved/restored patterns.
714
715 41. Applied Jeff Trawick's patch CMakeLists.txt, which "provides two new
716 features for Builds with MSVC:
717
718 1. Support pcre.rc and/or pcreposix.rc (as is already done for MinGW
719 builds). The .rc files can be used to set FileDescription and many other
720 attributes.
721
722 2. Add an option (-DINSTALL_MSVC_PDB) to enable installation of .pdb files.
723 This allows higher-level build scripts which want .pdb files to avoid
724 hard-coding the exact files needed."
725
726 42. Added support for [[:<:]] and [[:>:]] as used in the BSD POSIX library to
727 mean "start of word" and "end of word", respectively, as a transition aid.
728
729 43. A minimizing repeat of a class containing codepoints greater than 255 in
730 non-UTF 16-bit or 32-bit modes caused an internal error when PCRE was
731 compiled to use the heap for recursion.
732
733 44. Got rid of some compiler warnings for unused variables when UTF but not UCP
734 is configured.
735
736
737 Version 8.33 28-May-2013
738 ------------------------
739
740 1. Added 'U' to some constants that are compared to unsigned integers, to
741 avoid compiler signed/unsigned warnings. Added (int) casts to unsigned
742 variables that are added to signed variables, to ensure the result is
743 signed and can be negated.
744
745 2. Applied patch by Daniel Richard G for quashing MSVC warnings to the
746 CMake config files.
747
748 3. Revise the creation of config.h.generic so that all boolean macros are
749 #undefined, whereas non-boolean macros are #ifndef/#endif-ed. This makes
750 overriding via -D on the command line possible.
751
752 4. Changing the definition of the variable "op" in pcre_exec.c from pcre_uchar
753 to unsigned int is reported to make a quite noticeable speed difference in
754 a specific Windows environment. Testing on Linux did also appear to show
755 some benefit (and it is clearly not harmful). Also fixed the definition of
756 Xop which should be unsigned.
757
758 5. Related to (4), changing the definition of the intermediate variable cc
759 in repeated character loops from pcre_uchar to pcre_uint32 also gave speed
760 improvements.
761
762 6. Fix forward search in JIT when link size is 3 or greater. Also removed some
763 unnecessary spaces.
764
765 7. Adjust autogen.sh and configure.ac to lose warnings given by automake 1.12
766 and later.
767
768 8. Fix two buffer over read issues in 16 and 32 bit modes. Affects JIT only.
769
770 9. Optimizing fast_forward_start_bits in JIT.
771
772 10. Adding support for callouts in JIT, and fixing some issues revealed
773 during this work. Namely:
774
775 (a) Unoptimized capturing brackets incorrectly reset on backtrack.
776
777 (b) Minimum length was not checked before the matching is started.
778
779 11. The value of capture_last that is passed to callouts was incorrect in some
780 cases when there was a capture on one path that was subsequently abandoned
781 after a backtrack. Also, the capture_last value is now reset after a
782 recursion, since all captures are also reset in this case.
783
784 12. The interpreter no longer returns the "too many substrings" error in the
785 case when an overflowing capture is in a branch that is subsequently
786 abandoned after a backtrack.
787
788 13. In the pathological case when an offset vector of size 2 is used, pcretest
789 now prints out the matched string after a yield of 0 or 1.
790
791 14. Inlining subpatterns in recursions, when certain conditions are fulfilled.
792 Only supported by the JIT compiler at the moment.
793
794 15. JIT compiler now supports 32 bit Macs thanks to Lawrence Velazquez.
795
796 16. Partial matches now set offsets[2] to the "bumpalong" value, that is, the
797 offset of the starting point of the matching process, provided the offsets
798 vector is large enough.
799
800 17. The \A escape now records a lookbehind value of 1, though its execution
801 does not actually inspect the previous character. This is to ensure that,
802 in partial multi-segment matching, at least one character from the old
803 segment is retained when a new segment is processed. Otherwise, if there
804 are no lookbehinds in the pattern, \A might match incorrectly at the start
805 of a new segment.
806
807 18. Added some #ifdef __VMS code into pcretest.c to help VMS implementations.
808
809 19. Redefined some pcre_uchar variables in pcre_exec.c as pcre_uint32; this
810 gives some modest performance improvement in 8-bit mode.
811
812 20. Added the PCRE-specific property \p{Xuc} for matching characters that can
813 be expressed in certain programming languages using Universal Character
814 Names.
815
816 21. Unicode validation has been updated in the light of Unicode Corrigendum #9,
817 which points out that "non characters" are not "characters that may not
818 appear in Unicode strings" but rather "characters that are reserved for
819 internal use and have only local meaning".
820
821 22. When a pattern was compiled with automatic callouts (PCRE_AUTO_CALLOUT) and
822 there was a conditional group that depended on an assertion, if the
823 assertion was false, the callout that immediately followed the alternation
824 in the condition was skipped when pcre_exec() was used for matching.
825
826 23. Allow an explicit callout to be inserted before an assertion that is the
827 condition for a conditional group, for compatibility with automatic
828 callouts, which always insert a callout at this point.
829
830 24. In 8.31, (*COMMIT) was confined to within a recursive subpattern. Perl also
831 confines (*SKIP) and (*PRUNE) in the same way, and this has now been done.
832
833 25. (*PRUNE) is now supported by the JIT compiler.
834
835 26. Fix infinite loop when /(?<=(*SKIP)ac)a/ is matched against aa.
836
837 27. Fix the case where there are two or more SKIPs with arguments that may be
838 ignored.
839
840 28. (*SKIP) is now supported by the JIT compiler.
841
842 29. (*THEN) is now supported by the JIT compiler.
843
844 30. Update RunTest with additional test selector options.
845
846 31. The way PCRE handles backtracking verbs has been changed in two ways.
847
848 (1) Previously, in something like (*COMMIT)(*SKIP), COMMIT would override
849 SKIP. Now, PCRE acts on whichever backtracking verb is reached first by
850 backtracking. In some cases this makes it more Perl-compatible, but Perl's
851 rather obscure rules do not always do the same thing.
852
853 (2) Previously, backtracking verbs were confined within assertions. This is
854 no longer the case for positive assertions, except for (*ACCEPT). Again,
855 this sometimes improves Perl compatibility, and sometimes does not.
856
857 32. A number of tests that were in test 2 because Perl did things differently
858 have been moved to test 1, because either Perl or PCRE has changed, and
859 these tests are now compatible.
860
861 32. Backtracking control verbs are now handled in the same way in JIT and
862 interpreter.
863
864 33. An opening parenthesis in a MARK/PRUNE/SKIP/THEN name in a pattern that
865 contained a forward subroutine reference caused a compile error.
866
867 34. Auto-detect and optimize limited repetitions in JIT.
868
869 35. Implement PCRE_NEVER_UTF to lock out the use of UTF, in particular,
870 blocking (*UTF) etc.
871
872 36. In the interpreter, maximizing pattern repetitions for characters and
873 character types now use tail recursion, which reduces stack usage.
874
875 37. The value of the max lookbehind was not correctly preserved if a compiled
876 and saved regex was reloaded on a host of different endianness.
877
878 38. Implemented (*LIMIT_MATCH) and (*LIMIT_RECURSION). As part of the extension
879 of the compiled pattern block, expand the flags field from 16 to 32 bits
880 because it was almost full.
881
882 39. Try madvise first before posix_madvise.
883
884 40. Change 7 for PCRE 7.9 made it impossible for pcregrep to find empty lines
885 with a pattern such as ^$. It has taken 4 years for anybody to notice! The
886 original change locked out all matches of empty strings. This has been
887 changed so that one match of an empty string per line is recognized.
888 Subsequent searches on the same line (for colouring or for --only-matching,
889 for example) do not recognize empty strings.
890
891 41. Applied a user patch to fix a number of spelling mistakes in comments.
892
893 42. Data lines longer than 65536 caused pcretest to crash.
894
895 43. Clarified the data type for length and startoffset arguments for pcre_exec
896 and pcre_dfa_exec in the function-specific man pages, where they were
897 explicitly stated to be in bytes, never having been updated. I also added
898 some clarification to the pcreapi man page.
899
900 44. A call to pcre_dfa_exec() with an output vector size less than 2 caused
901 a segmentation fault.
902
903
904 Version 8.32 30-November-2012
905 -----------------------------
906
907 1. Improved JIT compiler optimizations for first character search and single
908 character iterators.
909
910 2. Supporting IBM XL C compilers for PPC architectures in the JIT compiler.
911 Patch by Daniel Richard G.
912
913 3. Single character iterator optimizations in the JIT compiler.
914
915 4. Improved JIT compiler optimizations for character ranges.
916
917 5. Rename the "leave" variable names to "quit" to improve WinCE compatibility.
918 Reported by Giuseppe D'Angelo.
919
920 6. The PCRE_STARTLINE bit, indicating that a match can occur only at the start
921 of a line, was being set incorrectly in cases where .* appeared inside
922 atomic brackets at the start of a pattern, or where there was a subsequent
923 *PRUNE or *SKIP.
924
925 7. Improved instruction cache flush for POWER/PowerPC.
926 Patch by Daniel Richard G.
927
928 8. Fixed a number of issues in pcregrep, making it more compatible with GNU
929 grep:
930
931 (a) There is now no limit to the number of patterns to be matched.
932
933 (b) An error is given if a pattern is too long.
934
935 (c) Multiple uses of --exclude, --exclude-dir, --include, and --include-dir
936 are now supported.
937
938 (d) --exclude-from and --include-from (multiple use) have been added.
939
940 (e) Exclusions and inclusions now apply to all files and directories, not
941 just to those obtained from scanning a directory recursively.
942
943 (f) Multiple uses of -f and --file-list are now supported.
944
945 (g) In a Windows environment, the default for -d has been changed from
946 "read" (the GNU grep default) to "skip", because otherwise the presence
947 of a directory in the file list provokes an error.
948
949 (h) The documentation has been revised and clarified in places.
950
951 9. Improve the matching speed of capturing brackets.
952
953 10. Changed the meaning of \X so that it now matches a Unicode extended
954 grapheme cluster.
955
956 11. Patch by Daniel Richard G to the autoconf files to add a macro for sorting
957 out POSIX threads when JIT support is configured.
958
959 12. Added support for PCRE_STUDY_EXTRA_NEEDED.
960
961 13. In the POSIX wrapper regcomp() function, setting re_nsub field in the preg
962 structure could go wrong in environments where size_t is not the same size
963 as int.
964
965 14. Applied user-supplied patch to pcrecpp.cc to allow PCRE_NO_UTF8_CHECK to be
966 set.
967
968 15. The EBCDIC support had decayed; later updates to the code had included
969 explicit references to (e.g.) \x0a instead of CHAR_LF. There has been a
970 general tidy up of EBCDIC-related issues, and the documentation was also
971 not quite right. There is now a test that can be run on ASCII systems to
972 check some of the EBCDIC-related things (but is it not a full test).
973
974 16. The new PCRE_STUDY_EXTRA_NEEDED option is now used by pcregrep, resulting
975 in a small tidy to the code.
976
977 17. Fix JIT tests when UTF is disabled and both 8 and 16 bit mode are enabled.
978
979 18. If the --only-matching (-o) option in pcregrep is specified multiple
980 times, each one causes appropriate output. For example, -o1 -o2 outputs the
981 substrings matched by the 1st and 2nd capturing parentheses. A separating
982 string can be specified by --om-separator (default empty).
983
984 19. Improving the first n character searches.
985
986 20. Turn case lists for horizontal and vertical white space into macros so that
987 they are defined only once.
988
989 21. This set of changes together give more compatible Unicode case-folding
990 behaviour for characters that have more than one other case when UCP
991 support is available.
992
993 (a) The Unicode property table now has offsets into a new table of sets of
994 three or more characters that are case-equivalent. The MultiStage2.py
995 script that generates these tables (the pcre_ucd.c file) now scans
996 CaseFolding.txt instead of UnicodeData.txt for character case
997 information.
998
999 (b) The code for adding characters or ranges of characters to a character
1000 class has been abstracted into a generalized function that also handles
1001 case-independence. In UTF-mode with UCP support, this uses the new data
1002 to handle characters with more than one other case.
1003
1004 (c) A bug that is fixed as a result of (b) is that codepoints less than 256
1005 whose other case is greater than 256 are now correctly matched
1006 caselessly. Previously, the high codepoint matched the low one, but not
1007 vice versa.
1008
1009 (d) The processing of \h, \H, \v, and \ in character classes now makes use
1010 of the new class addition function, using character lists defined as
1011 macros alongside the case definitions of 20 above.
1012
1013 (e) Caseless back references now work with characters that have more than
1014 one other case.
1015
1016 (f) General caseless matching of characters with more than one other case
1017 is supported.
1018
1019 22. Unicode character properties were updated from Unicode 6.2.0
1020
1021 23. Improved CMake support under Windows. Patch by Daniel Richard G.
1022
1023 24. Add support for 32-bit character strings, and UTF-32
1024
1025 25. Major JIT compiler update (code refactoring and bugfixing).
1026 Experimental Sparc 32 support is added.
1027
1028 26. Applied a modified version of Daniel Richard G's patch to create
1029 pcre.h.generic and config.h.generic by "make" instead of in the
1030 PrepareRelease script.
1031
1032 27. Added a definition for CHAR_NULL (helpful for the z/OS port), and use it in
1033 pcre_compile.c when checking for a zero character.
1034
1035 28. Introducing a native interface for JIT. Through this interface, the compiled
1036 machine code can be directly executed. The purpose of this interface is to
1037 provide fast pattern matching, so several sanity checks are not performed.
1038 However, feature tests are still performed. The new interface provides
1039 1.4x speedup compared to the old one.
1040
1041 29. If pcre_exec() or pcre_dfa_exec() was called with a negative value for
1042 the subject string length, the error given was PCRE_ERROR_BADOFFSET, which
1043 was confusing. There is now a new error PCRE_ERROR_BADLENGTH for this case.
1044
1045 30. In 8-bit UTF-8 mode, pcretest failed to give an error for data codepoints
1046 greater than 0x7fffffff (which cannot be represented in UTF-8, even under
1047 the "old" RFC 2279). Instead, it ended up passing a negative length to
1048 pcre_exec().
1049
1050 31. Add support for GCC's visibility feature to hide internal functions.
1051
1052 32. Running "pcretest -C pcre8" or "pcretest -C pcre16" gave a spurious error
1053 "unknown -C option" after outputting 0 or 1.
1054
1055 33. There is now support for generating a code coverage report for the test
1056 suite in environments where gcc is the compiler and lcov is installed. This
1057 is mainly for the benefit of the developers.
1058
1059 34. If PCRE is built with --enable-valgrind, certain memory regions are marked
1060 unaddressable using valgrind annotations, allowing valgrind to detect
1061 invalid memory accesses. This is mainly for the benefit of the developers.
1062
1063 25. (*UTF) can now be used to start a pattern in any of the three libraries.
1064
1065 26. Give configure error if --enable-cpp but no C++ compiler found.
1066
1067
1068 Version 8.31 06-July-2012
1069 -------------------------
1070
1071 1. Fixing a wrong JIT test case and some compiler warnings.
1072
1073 2. Removed a bashism from the RunTest script.
1074
1075 3. Add a cast to pcre_exec.c to fix the warning "unary minus operator applied
1076 to unsigned type, result still unsigned" that was given by an MS compiler
1077 on encountering the code "-sizeof(xxx)".
1078
1079 4. Partial matching support is added to the JIT compiler.
1080
1081 5. Fixed several bugs concerned with partial matching of items that consist
1082 of more than one character:
1083
1084 (a) /^(..)\1/ did not partially match "aba" because checking references was
1085 done on an "all or nothing" basis. This also applied to repeated
1086 references.
1087
1088 (b) \R did not give a hard partial match if \r was found at the end of the
1089 subject.
1090
1091 (c) \X did not give a hard partial match after matching one or more
1092 characters at the end of the subject.
1093
1094 (d) When newline was set to CRLF, a pattern such as /a$/ did not recognize
1095 a partial match for the string "\r".
1096
1097 (e) When newline was set to CRLF, the metacharacter "." did not recognize
1098 a partial match for a CR character at the end of the subject string.
1099
1100 6. If JIT is requested using /S++ or -s++ (instead of just /S+ or -s+) when
1101 running pcretest, the text "(JIT)" added to the output whenever JIT is
1102 actually used to run the match.
1103
1104 7. Individual JIT compile options can be set in pcretest by following -s+[+]
1105 or /S+[+] with a digit between 1 and 7.
1106
1107 8. OP_NOT now supports any UTF character not just single-byte ones.
1108
1109 9. (*MARK) control verb is now supported by the JIT compiler.
1110
1111 10. The command "./RunTest list" lists the available tests without actually
1112 running any of them. (Because I keep forgetting what they all are.)
1113
1114 11. Add PCRE_INFO_MAXLOOKBEHIND.
1115
1116 12. Applied a (slightly modified) user-supplied patch that improves performance
1117 when the heap is used for recursion (compiled with --disable-stack-for-
1118 recursion). Instead of malloc and free for each heap frame each time a
1119 logical recursion happens, frames are retained on a chain and re-used where
1120 possible. This sometimes gives as much as 30% improvement.
1121
1122 13. As documented, (*COMMIT) is now confined to within a recursive subpattern
1123 call.
1124
1125 14. As documented, (*COMMIT) is now confined to within a positive assertion.
1126
1127 15. It is now possible to link pcretest with libedit as an alternative to
1128 libreadline.
1129
1130 16. (*COMMIT) control verb is now supported by the JIT compiler.
1131
1132 17. The Unicode data tables have been updated to Unicode 6.1.0.
1133
1134 18. Added --file-list option to pcregrep.
1135
1136 19. Added binary file support to pcregrep, including the -a, --binary-files,
1137 -I, and --text options.
1138
1139 20. The madvise function is renamed for posix_madvise for QNX compatibility
1140 reasons. Fixed by Giuseppe D'Angelo.
1141
1142 21. Fixed a bug for backward assertions with REVERSE 0 in the JIT compiler.
1143
1144 22. Changed the option for creating symbolic links for 16-bit man pages from
1145 -s to -sf so that re-installing does not cause issues.
1146
1147 23. Support PCRE_NO_START_OPTIMIZE in JIT as (*MARK) support requires it.
1148
1149 24. Fixed a very old bug in pcretest that caused errors with restarted DFA
1150 matches in certain environments (the workspace was not being correctly
1151 retained). Also added to pcre_dfa_exec() a simple plausibility check on
1152 some of the workspace data at the beginning of a restart.
1153
1154 25. \s*\R was auto-possessifying the \s* when it should not, whereas \S*\R
1155 was not doing so when it should - probably a typo introduced by SVN 528
1156 (change 8.10/14).
1157
1158 26. When PCRE_UCP was not set, \w+\x{c4} was incorrectly auto-possessifying the
1159 \w+ when the character tables indicated that \x{c4} was a word character.
1160 There were several related cases, all because the tests for doing a table
1161 lookup were testing for characters less than 127 instead of 255.
1162
1163 27. If a pattern contains capturing parentheses that are not used in a match,
1164 their slots in the ovector are set to -1. For those that are higher than
1165 any matched groups, this happens at the end of processing. In the case when
1166 there were back references that the ovector was too small to contain
1167 (causing temporary malloc'd memory to be used during matching), and the
1168 highest capturing number was not used, memory off the end of the ovector
1169 was incorrectly being set to -1. (It was using the size of the temporary
1170 memory instead of the true size.)
1171
1172 28. To catch bugs like 27 using valgrind, when pcretest is asked to specify an
1173 ovector size, it uses memory at the end of the block that it has got.
1174
1175 29. Check for an overlong MARK name and give an error at compile time. The
1176 limit is 255 for the 8-bit library and 65535 for the 16-bit library.
1177
1178 30. JIT compiler update.
1179
1180 31. JIT is now supported on jailbroken iOS devices. Thanks for Ruiger
1181 Rill for the patch.
1182
1183 32. Put spaces around SLJIT_PRINT_D in the JIT compiler. Required by CXX11.
1184
1185 33. Variable renamings in the PCRE-JIT compiler. No functionality change.
1186
1187 34. Fixed typos in pcregrep: in two places there was SUPPORT_LIBZ2 instead of
1188 SUPPORT_LIBBZ2. This caused a build problem when bzip2 but not gzip (zlib)
1189 was enabled.
1190
1191 35. Improve JIT code generation for greedy plus quantifier.
1192
1193 36. When /((?:a?)*)*c/ or /((?>a?)*)*c/ was matched against "aac", it set group
1194 1 to "aa" instead of to an empty string. The bug affected repeated groups
1195 that could potentially match an empty string.
1196
1197 37. Optimizing single character iterators in JIT.
1198
1199 38. Wide characters specified with \uxxxx in JavaScript mode are now subject to
1200 the same checks as \x{...} characters in non-JavaScript mode. Specifically,
1201 codepoints that are too big for the mode are faulted, and in a UTF mode,
1202 disallowed codepoints are also faulted.
1203
1204 39. If PCRE was compiled with UTF support, in three places in the DFA
1205 matcher there was code that should only have been obeyed in UTF mode, but
1206 was being obeyed unconditionally. In 8-bit mode this could cause incorrect
1207 processing when bytes with values greater than 127 were present. In 16-bit
1208 mode the bug would be provoked by values in the range 0xfc00 to 0xdc00. In
1209 both cases the values are those that cannot be the first data item in a UTF
1210 character. The three items that might have provoked this were recursions,
1211 possessively repeated groups, and atomic groups.
1212
1213 40. Ensure that libpcre is explicitly listed in the link commands for pcretest
1214 and pcregrep, because some OS require shared objects to be explicitly
1215 passed to ld, causing the link step to fail if they are not.
1216
1217 41. There were two incorrect #ifdefs in pcre_study.c, meaning that, in 16-bit
1218 mode, patterns that started with \h* or \R* might be incorrectly matched.
1219
1220
1221 Version 8.30 04-February-2012
1222 -----------------------------
1223
1224 1. Renamed "isnumber" as "is_a_number" because in some Mac environments this
1225 name is defined in ctype.h.
1226
1227 2. Fixed a bug in fixed-length calculation for lookbehinds that would show up
1228 only in quite long subpatterns.
1229
1230 3. Removed the function pcre_info(), which has been obsolete and deprecated
1231 since it was replaced by pcre_fullinfo() in February 2000.
1232
1233 4. For a non-anchored pattern, if (*SKIP) was given with a name that did not
1234 match a (*MARK), and the match failed at the start of the subject, a
1235 reference to memory before the start of the subject could occur. This bug
1236 was introduced by fix 17 of release 8.21.
1237
1238 5. A reference to an unset group with zero minimum repetition was giving
1239 totally wrong answers (in non-JavaScript-compatibility mode). For example,
1240 /(another)?(\1?)test/ matched against "hello world test". This bug was
1241 introduced in release 8.13.
1242
1243 6. Add support for 16-bit character strings (a large amount of work involving
1244 many changes and refactorings).
1245
1246 7. RunGrepTest failed on msys because \r\n was replaced by whitespace when the
1247 command "pattern=`printf 'xxx\r\njkl'`" was run. The pattern is now taken
1248 from a file.
1249
1250 8. Ovector size of 2 is also supported by JIT based pcre_exec (the ovector size
1251 rounding is not applied in this particular case).
1252
1253 9. The invalid Unicode surrogate codepoints U+D800 to U+DFFF are now rejected
1254 if they appear, or are escaped, in patterns.
1255
1256 10. Get rid of a number of -Wunused-but-set-variable warnings.
1257
1258 11. The pattern /(?=(*:x))(q|)/ matches an empty string, and returns the mark
1259 "x". The similar pattern /(?=(*:x))((*:y)q|)/ did not return a mark at all.
1260 Oddly, Perl behaves the same way. PCRE has been fixed so that this pattern
1261 also returns the mark "x". This bug applied to capturing parentheses,
1262 non-capturing parentheses, and atomic parentheses. It also applied to some
1263 assertions.
1264
1265 12. Stephen Kelly's patch to CMakeLists.txt allows it to parse the version
1266 information out of configure.ac instead of relying on pcre.h.generic, which
1267 is not stored in the repository.
1268
1269 13. Applied Dmitry V. Levin's patch for a more portable method for linking with
1270 -lreadline.
1271
1272 14. ZH added PCRE_CONFIG_JITTARGET; added its output to pcretest -C.
1273
1274 15. Applied Graycode's patch to put the top-level frame on the stack rather
1275 than the heap when not using the stack for recursion. This gives a
1276 performance improvement in many cases when recursion is not deep.
1277
1278 16. Experimental code added to "pcretest -C" to output the stack frame size.
1279
1280
1281 Version 8.21 12-Dec-2011
1282 ------------------------
1283
1284 1. Updating the JIT compiler.
1285
1286 2. JIT compiler now supports OP_NCREF, OP_RREF and OP_NRREF. New test cases
1287 are added as well.
1288
1289 3. Fix cache-flush issue on PowerPC (It is still an experimental JIT port).
1290 PCRE_EXTRA_TABLES is not suported by JIT, and should be checked before
1291 calling _pcre_jit_exec. Some extra comments are added.
1292
1293 4. (*MARK) settings inside atomic groups that do not contain any capturing
1294 parentheses, for example, (?>a(*:m)), were not being passed out. This bug
1295 was introduced by change 18 for 8.20.
1296
1297 5. Supporting of \x, \U and \u in JavaScript compatibility mode based on the
1298 ECMA-262 standard.
1299
1300 6. Lookbehinds such as (?<=a{2}b) that contained a fixed repetition were
1301 erroneously being rejected as "not fixed length" if PCRE_CASELESS was set.
1302 This bug was probably introduced by change 9 of 8.13.
1303
1304 7. While fixing 6 above, I noticed that a number of other items were being
1305 incorrectly rejected as "not fixed length". This arose partly because newer
1306 opcodes had not been added to the fixed-length checking code. I have (a)
1307 corrected the bug and added tests for these items, and (b) arranged for an
1308 error to occur if an unknown opcode is encountered while checking for fixed
1309 length instead of just assuming "not fixed length". The items that were
1310 rejected were: (*ACCEPT), (*COMMIT), (*FAIL), (*MARK), (*PRUNE), (*SKIP),
1311 (*THEN), \h, \H, \v, \V, and single character negative classes with fixed
1312 repetitions, e.g. [^a]{3}, with and without PCRE_CASELESS.
1313
1314 8. A possessively repeated conditional subpattern such as (?(?=c)c|d)++ was
1315 being incorrectly compiled and would have given unpredicatble results.
1316
1317 9. A possessively repeated subpattern with minimum repeat count greater than
1318 one behaved incorrectly. For example, (A){2,}+ behaved as if it was
1319 (A)(A)++ which meant that, after a subsequent mismatch, backtracking into
1320 the first (A) could occur when it should not.
1321
1322 10. Add a cast and remove a redundant test from the code.
1323
1324 11. JIT should use pcre_malloc/pcre_free for allocation.
1325
1326 12. Updated pcre-config so that it no longer shows -L/usr/lib, which seems
1327 best practice nowadays, and helps with cross-compiling. (If the exec_prefix
1328 is anything other than /usr, -L is still shown).
1329
1330 13. In non-UTF-8 mode, \C is now supported in lookbehinds and DFA matching.
1331
1332 14. Perl does not support \N without a following name in a [] class; PCRE now
1333 also gives an error.
1334
1335 15. If a forward reference was repeated with an upper limit of around 2000,
1336 it caused the error "internal error: overran compiling workspace". The
1337 maximum number of forward references (including repeats) was limited by the
1338 internal workspace, and dependent on the LINK_SIZE. The code has been
1339 rewritten so that the workspace expands (via pcre_malloc) if necessary, and
1340 the default depends on LINK_SIZE. There is a new upper limit (for safety)
1341 of around 200,000 forward references. While doing this, I also speeded up
1342 the filling in of repeated forward references.
1343
1344 16. A repeated forward reference in a pattern such as (a)(?2){2}(.) was
1345 incorrectly expecting the subject to contain another "a" after the start.
1346
1347 17. When (*SKIP:name) is activated without a corresponding (*MARK:name) earlier
1348 in the match, the SKIP should be ignored. This was not happening; instead
1349 the SKIP was being treated as NOMATCH. For patterns such as
1350 /A(*MARK:A)A+(*SKIP:B)Z|AAC/ this meant that the AAC branch was never
1351 tested.
1352
1353 18. The behaviour of (*MARK), (*PRUNE), and (*THEN) has been reworked and is
1354 now much more compatible with Perl, in particular in cases where the result
1355 is a non-match for a non-anchored pattern. For example, if
1356 /b(*:m)f|a(*:n)w/ is matched against "abc", the non-match returns the name
1357 "m", where previously it did not return a name. A side effect of this
1358 change is that for partial matches, the last encountered mark name is
1359 returned, as for non matches. A number of tests that were previously not
1360 Perl-compatible have been moved into the Perl-compatible test files. The
1361 refactoring has had the pleasing side effect of removing one argument from
1362 the match() function, thus reducing its stack requirements.
1363
1364 19. If the /S+ option was used in pcretest to study a pattern using JIT,
1365 subsequent uses of /S (without +) incorrectly behaved like /S+.
1366
1367 21. Retrieve executable code size support for the JIT compiler and fixing
1368 some warnings.
1369
1370 22. A caseless match of a UTF-8 character whose other case uses fewer bytes did
1371 not work when the shorter character appeared right at the end of the
1372 subject string.
1373
1374 23. Added some (int) casts to non-JIT modules to reduce warnings on 64-bit
1375 systems.
1376
1377 24. Added PCRE_INFO_JITSIZE to pass on the value from (21) above, and also
1378 output it when the /M option is used in pcretest.
1379
1380 25. The CheckMan script was not being included in the distribution. Also, added
1381 an explicit "perl" to run Perl scripts from the PrepareRelease script
1382 because this is reportedly needed in Windows.
1383
1384 26. If study data was being save in a file and studying had not found a set of
1385 "starts with" bytes for the pattern, the data written to the file (though
1386 never used) was taken from uninitialized memory and so caused valgrind to
1387 complain.
1388
1389 27. Updated RunTest.bat as provided by Sheri Pierce.
1390
1391 28. Fixed a possible uninitialized memory bug in pcre_jit_compile.c.
1392
1393 29. Computation of memory usage for the table of capturing group names was
1394 giving an unnecessarily large value.
1395
1396
1397 Version 8.20 21-Oct-2011
1398 ------------------------
1399
1400 1. Change 37 of 8.13 broke patterns like [:a]...[b:] because it thought it had
1401 a POSIX class. After further experiments with Perl, which convinced me that
1402 Perl has bugs and confusions, a closing square bracket is no longer allowed
1403 in a POSIX name. This bug also affected patterns with classes that started
1404 with full stops.
1405
1406 2. If a pattern such as /(a)b|ac/ is matched against "ac", there is no
1407 captured substring, but while checking the failing first alternative,
1408 substring 1 is temporarily captured. If the output vector supplied to
1409 pcre_exec() was not big enough for this capture, the yield of the function
1410 was still zero ("insufficient space for captured substrings"). This cannot
1411 be totally fixed without adding another stack variable, which seems a lot
1412 of expense for a edge case. However, I have improved the situation in cases
1413 such as /(a)(b)x|abc/ matched against "abc", where the return code
1414 indicates that fewer than the maximum number of slots in the ovector have
1415 been set.
1416
1417 3. Related to (2) above: when there are more back references in a pattern than
1418 slots in the output vector, pcre_exec() uses temporary memory during
1419 matching, and copies in the captures as far as possible afterwards. It was
1420 using the entire output vector, but this conflicts with the specification
1421 that only 2/3 is used for passing back captured substrings. Now it uses
1422 only the first 2/3, for compatibility. This is, of course, another edge
1423 case.
1424
1425 4. Zoltan Herczeg's just-in-time compiler support has been integrated into the
1426 main code base, and can be used by building with --enable-jit. When this is
1427 done, pcregrep automatically uses it unless --disable-pcregrep-jit or the
1428 runtime --no-jit option is given.
1429
1430 5. When the number of matches in a pcre_dfa_exec() run exactly filled the
1431 ovector, the return from the function was zero, implying that there were
1432 other matches that did not fit. The correct "exactly full" value is now
1433 returned.
1434
1435 6. If a subpattern that was called recursively or as a subroutine contained
1436 (*PRUNE) or any other control that caused it to give a non-standard return,
1437 invalid errors such as "Error -26 (nested recursion at the same subject
1438 position)" or even infinite loops could occur.
1439
1440 7. If a pattern such as /a(*SKIP)c|b(*ACCEPT)|/ was studied, it stopped
1441 computing the minimum length on reaching *ACCEPT, and so ended up with the
1442 wrong value of 1 rather than 0. Further investigation indicates that
1443 computing a minimum subject length in the presence of *ACCEPT is difficult
1444 (think back references, subroutine calls), and so I have changed the code
1445 so that no minimum is registered for a pattern that contains *ACCEPT.
1446
1447 8. If (*THEN) was present in the first (true) branch of a conditional group,
1448 it was not handled as intended. [But see 16 below.]
1449
1450 9. Replaced RunTest.bat and CMakeLists.txt with improved versions provided by
1451 Sheri Pierce.
1452
1453 10. A pathological pattern such as /(*ACCEPT)a/ was miscompiled, thinking that
1454 the first byte in a match must be "a".
1455
1456 11. Change 17 for 8.13 increased the recursion depth for patterns like
1457 /a(?:.)*?a/ drastically. I've improved things by remembering whether a
1458 pattern contains any instances of (*THEN). If it does not, the old
1459 optimizations are restored. It would be nice to do this on a per-group
1460 basis, but at the moment that is not feasible.
1461
1462 12. In some environments, the output of pcretest -C is CRLF terminated. This
1463 broke RunTest's code that checks for the link size. A single white space
1464 character after the value is now allowed for.
1465
1466 13. RunTest now checks for the "fr" locale as well as for "fr_FR" and "french".
1467 For "fr", it uses the Windows-specific input and output files.
1468
1469 14. If (*THEN) appeared in a group that was called recursively or as a
1470 subroutine, it did not work as intended. [But see next item.]
1471
1472 15. Consider the pattern /A (B(*THEN)C) | D/ where A, B, C, and D are complex
1473 pattern fragments (but not containing any | characters). If A and B are
1474 matched, but there is a failure in C so that it backtracks to (*THEN), PCRE
1475 was behaving differently to Perl. PCRE backtracked into A, but Perl goes to
1476 D. In other words, Perl considers parentheses that do not contain any |
1477 characters to be part of a surrounding alternative, whereas PCRE was
1478 treading (B(*THEN)C) the same as (B(*THEN)C|(*FAIL)) -- which Perl handles
1479 differently. PCRE now behaves in the same way as Perl, except in the case
1480 of subroutine/recursion calls such as (?1) which have in any case always
1481 been different (but PCRE had them first :-).
1482
1483 16. Related to 15 above: Perl does not treat the | in a conditional group as
1484 creating alternatives. Such a group is treated in the same way as an
1485 ordinary group without any | characters when processing (*THEN). PCRE has
1486 been changed to match Perl's behaviour.
1487
1488 17. If a user had set PCREGREP_COLO(U)R to something other than 1:31, the
1489 RunGrepTest script failed.
1490
1491 18. Change 22 for version 13 caused atomic groups to use more stack. This is
1492 inevitable for groups that contain captures, but it can lead to a lot of
1493 stack use in large patterns. The old behaviour has been restored for atomic
1494 groups that do not contain any capturing parentheses.
1495
1496 19. If the PCRE_NO_START_OPTIMIZE option was set for pcre_compile(), it did not
1497 suppress the check for a minimum subject length at run time. (If it was
1498 given to pcre_exec() or pcre_dfa_exec() it did work.)
1499
1500 20. Fixed an ASCII-dependent infelicity in pcretest that would have made it
1501 fail to work when decoding hex characters in data strings in EBCDIC
1502 environments.
1503
1504 21. It appears that in at least one Mac OS environment, the isxdigit() function
1505 is implemented as a macro that evaluates to its argument more than once,
1506 contravening the C 90 Standard (I haven't checked a later standard). There
1507 was an instance in pcretest which caused it to go wrong when processing
1508 \x{...} escapes in subject strings. The has been rewritten to avoid using
1509 things like p++ in the argument of isxdigit().
1510
1511
1512 Version 8.13 16-Aug-2011
1513 ------------------------
1514
1515 1. The Unicode data tables have been updated to Unicode 6.0.0.
1516
1517 2. Two minor typos in pcre_internal.h have been fixed.
1518
1519 3. Added #include <string.h> to pcre_scanner_unittest.cc, pcrecpp.cc, and
1520 pcrecpp_unittest.cc. They are needed for strcmp(), memset(), and strchr()
1521 in some environments (e.g. Solaris 10/SPARC using Sun Studio 12U2).
1522
1523 4. There were a number of related bugs in the code for matching backrefences
1524 caselessly in UTF-8 mode when codes for the characters concerned were
1525 different numbers of bytes. For example, U+023A and U+2C65 are an upper
1526 and lower case pair, using 2 and 3 bytes, respectively. The main bugs were:
1527 (a) A reference to 3 copies of a 2-byte code matched only 2 of a 3-byte
1528 code. (b) A reference to 2 copies of a 3-byte code would not match 2 of a
1529 2-byte code at the end of the subject (it thought there wasn't enough data
1530 left).
1531
1532 5. Comprehensive information about what went wrong is now returned by
1533 pcre_exec() and pcre_dfa_exec() when the UTF-8 string check fails, as long
1534 as the output vector has at least 2 elements. The offset of the start of
1535 the failing character and a reason code are placed in the vector.
1536
1537 6. When the UTF-8 string check fails for pcre_compile(), the offset that is
1538 now returned is for the first byte of the failing character, instead of the
1539 last byte inspected. This is an incompatible change, but I hope it is small
1540 enough not to be a problem. It makes the returned offset consistent with
1541 pcre_exec() and pcre_dfa_exec().
1542
1543 7. pcretest now gives a text phrase as well as the error number when
1544 pcre_exec() or pcre_dfa_exec() fails; if the error is a UTF-8 check
1545 failure, the offset and reason code are output.
1546
1547 8. When \R was used with a maximizing quantifier it failed to skip backwards
1548 over a \r\n pair if the subsequent match failed. Instead, it just skipped
1549 back over a single character (\n). This seems wrong (because it treated the
1550 two characters as a single entity when going forwards), conflicts with the
1551 documentation that \R is equivalent to (?>\r\n|\n|...etc), and makes the
1552 behaviour of \R* different to (\R)*, which also seems wrong. The behaviour
1553 has been changed.
1554
1555 9. Some internal refactoring has changed the processing so that the handling
1556 of the PCRE_CASELESS and PCRE_MULTILINE options is done entirely at compile
1557 time (the PCRE_DOTALL option was changed this way some time ago: version
1558 7.7 change 16). This has made it possible to abolish the OP_OPT op code,
1559 which was always a bit of a fudge. It also means that there is one less
1560 argument for the match() function, which reduces its stack requirements
1561 slightly. This change also fixes an incompatibility with Perl: the pattern
1562 (?i:([^b]))(?1) should not match "ab", but previously PCRE gave a match.
1563
1564 10. More internal refactoring has drastically reduced the number of recursive
1565 calls to match() for possessively repeated groups such as (abc)++ when
1566 using pcre_exec().
1567
1568 11. While implementing 10, a number of bugs in the handling of groups were
1569 discovered and fixed:
1570
1571 (?<=(a)+) was not diagnosed as invalid (non-fixed-length lookbehind).
1572 (a|)*(?1) gave a compile-time internal error.
1573 ((a|)+)+ did not notice that the outer group could match an empty string.
1574 (^a|^)+ was not marked as anchored.
1575 (.*a|.*)+ was not marked as matching at start or after a newline.
1576
1577 12. Yet more internal refactoring has removed another argument from the match()
1578 function. Special calls to this function are now indicated by setting a
1579 value in a variable in the "match data" data block.
1580
1581 13. Be more explicit in pcre_study() instead of relying on "default" for
1582 opcodes that mean there is no starting character; this means that when new
1583 ones are added and accidentally left out of pcre_study(), testing should
1584 pick them up.
1585
1586 14. The -s option of pcretest has been documented for ages as being an old
1587 synonym of -m (show memory usage). I have changed it to mean "force study
1588 for every regex", that is, assume /S for every regex. This is similar to -i
1589 and -d etc. It's slightly incompatible, but I'm hoping nobody is still
1590 using it. It makes it easier to run collections of tests with and without
1591 study enabled, and thereby test pcre_study() more easily. All the standard
1592 tests are now run with and without -s (but some patterns can be marked as
1593 "never study" - see 20 below).
1594
1595 15. When (*ACCEPT) was used in a subpattern that was called recursively, the
1596 restoration of the capturing data to the outer values was not happening
1597 correctly.
1598
1599 16. If a recursively called subpattern ended with (*ACCEPT) and matched an
1600 empty string, and PCRE_NOTEMPTY was set, pcre_exec() thought the whole
1601 pattern had matched an empty string, and so incorrectly returned a no
1602 match.
1603
1604 17. There was optimizing code for the last branch of non-capturing parentheses,
1605 and also for the obeyed branch of a conditional subexpression, which used
1606 tail recursion to cut down on stack usage. Unfortunately, now that there is
1607 the possibility of (*THEN) occurring in these branches, tail recursion is
1608 no longer possible because the return has to be checked for (*THEN). These
1609 two optimizations have therefore been removed. [But see 8.20/11 above.]
1610
1611 18. If a pattern containing \R was studied, it was assumed that \R always
1612 matched two bytes, thus causing the minimum subject length to be
1613 incorrectly computed because \R can also match just one byte.
1614
1615 19. If a pattern containing (*ACCEPT) was studied, the minimum subject length
1616 was incorrectly computed.
1617
1618 20. If /S is present twice on a test pattern in pcretest input, it now
1619 *disables* studying, thereby overriding the use of -s on the command line
1620 (see 14 above). This is necessary for one or two tests to keep the output
1621 identical in both cases.
1622
1623 21. When (*ACCEPT) was used in an assertion that matched an empty string and
1624 PCRE_NOTEMPTY was set, PCRE applied the non-empty test to the assertion.
1625
1626 22. When an atomic group that contained a capturing parenthesis was
1627 successfully matched, but the branch in which it appeared failed, the
1628 capturing was not being forgotten if a higher numbered group was later
1629 captured. For example, /(?>(a))b|(a)c/ when matching "ac" set capturing
1630 group 1 to "a", when in fact it should be unset. This applied to multi-
1631 branched capturing and non-capturing groups, repeated or not, and also to
1632 positive assertions (capturing in negative assertions does not happen
1633 in PCRE) and also to nested atomic groups.
1634
1635 23. Add the ++ qualifier feature to pcretest, to show the remainder of the
1636 subject after a captured substring, to make it easier to tell which of a
1637 number of identical substrings has been captured.
1638
1639 24. The way atomic groups are processed by pcre_exec() has been changed so that
1640 if they are repeated, backtracking one repetition now resets captured
1641 values correctly. For example, if ((?>(a+)b)+aabab) is matched against
1642 "aaaabaaabaabab" the value of captured group 2 is now correctly recorded as
1643 "aaa". Previously, it would have been "a". As part of this code
1644 refactoring, the way recursive calls are handled has also been changed.
1645
1646 25. If an assertion condition captured any substrings, they were not passed
1647 back unless some other capturing happened later. For example, if
1648 (?(?=(a))a) was matched against "a", no capturing was returned.
1649
1650 26. When studying a pattern that contained subroutine calls or assertions,
1651 the code for finding the minimum length of a possible match was handling
1652 direct recursions such as (xxx(?1)|yyy) but not mutual recursions (where
1653 group 1 called group 2 while simultaneously a separate group 2 called group
1654 1). A stack overflow occurred in this case. I have fixed this by limiting
1655 the recursion depth to 10.
1656
1657 27. Updated RunTest.bat in the distribution to the version supplied by Tom
1658 Fortmann. This supports explicit test numbers on the command line, and has
1659 argument validation and error reporting.
1660
1661 28. An instance of \X with an unlimited repeat could fail if at any point the
1662 first character it looked at was a mark character.
1663
1664 29. Some minor code refactoring concerning Unicode properties and scripts
1665 should reduce the stack requirement of match() slightly.
1666
1667 30. Added the '=' option to pcretest to check the setting of unused capturing
1668 slots at the end of the pattern, which are documented as being -1, but are
1669 not included in the return count.
1670
1671 31. If \k was not followed by a braced, angle-bracketed, or quoted name, PCRE
1672 compiled something random. Now it gives a compile-time error (as does
1673 Perl).
1674
1675 32. A *MARK encountered during the processing of a positive assertion is now
1676 recorded and passed back (compatible with Perl).
1677
1678 33. If --only-matching or --colour was set on a pcregrep call whose pattern
1679 had alternative anchored branches, the search for a second match in a line
1680 was done as if at the line start. Thus, for example, /^01|^02/ incorrectly
1681 matched the line "0102" twice. The same bug affected patterns that started
1682 with a backwards assertion. For example /\b01|\b02/ also matched "0102"
1683 twice.
1684
1685 34. Previously, PCRE did not allow quantification of assertions. However, Perl
1686 does, and because of capturing effects, quantifying parenthesized
1687 assertions may at times be useful. Quantifiers are now allowed for
1688 parenthesized assertions.
1689
1690 35. A minor code tidy in pcre_compile() when checking options for \R usage.
1691
1692 36. \g was being checked for fancy things in a character class, when it should
1693 just be a literal "g".
1694
1695 37. PCRE was rejecting [:a[:digit:]] whereas Perl was not. It seems that the
1696 appearance of a nested POSIX class supersedes an apparent external class.
1697 For example, [:a[:digit:]b:] matches "a", "b", ":", or a digit. Also,
1698 unescaped square brackets may also appear as part of class names. For
1699 example, [:a[:abc]b:] gives unknown class "[:abc]b:]". PCRE now behaves
1700 more like Perl. (But see 8.20/1 above.)
1701
1702 38. PCRE was giving an error for \N with a braced quantifier such as {1,} (this
1703 was because it thought it was \N{name}, which is not supported).
1704
1705 39. Add minix to OS list not supporting the -S option in pcretest.
1706
1707 40. PCRE tries to detect cases of infinite recursion at compile time, but it
1708 cannot analyze patterns in sufficient detail to catch mutual recursions
1709 such as ((?1))((?2)). There is now a runtime test that gives an error if a
1710 subgroup is called recursively as a subpattern for a second time at the
1711 same position in the subject string. In previous releases this might have
1712 been caught by the recursion limit, or it might have run out of stack.
1713
1714 41. A pattern such as /(?(R)a+|(?R)b)/ is quite safe, as the recursion can
1715 happen only once. PCRE was, however incorrectly giving a compile time error
1716 "recursive call could loop indefinitely" because it cannot analyze the
1717 pattern in sufficient detail. The compile time test no longer happens when
1718 PCRE is compiling a conditional subpattern, but actual runaway loops are
1719 now caught at runtime (see 40 above).
1720
1721 42. It seems that Perl allows any characters other than a closing parenthesis
1722 to be part of the NAME in (*MARK:NAME) and other backtracking verbs. PCRE
1723 has been changed to be the same.
1724
1725 43. Updated configure.ac to put in more quoting round AC_LANG_PROGRAM etc. so
1726 as not to get warnings when autogen.sh is called. Also changed
1727 AC_PROG_LIBTOOL (deprecated) to LT_INIT (the current macro).
1728
1729 44. To help people who use pcregrep to scan files containing exceedingly long
1730 lines, the following changes have been made:
1731
1732 (a) The default value of the buffer size parameter has been increased from
1733 8K to 20K. (The actual buffer used is three times this size.)
1734
1735 (b) The default can be changed by ./configure --with-pcregrep-bufsize when
1736 PCRE is built.
1737
1738 (c) A --buffer-size=n option has been added to pcregrep, to allow the size
1739 to be set at run time.
1740
1741 (d) Numerical values in pcregrep options can be followed by K or M, for
1742 example --buffer-size=50K.
1743
1744 (e) If a line being scanned overflows pcregrep's buffer, an error is now
1745 given and the return code is set to 2.
1746
1747 45. Add a pointer to the latest mark to the callout data block.
1748
1749 46. The pattern /.(*F)/, when applied to "abc" with PCRE_PARTIAL_HARD, gave a
1750 partial match of an empty string instead of no match. This was specific to
1751 the use of ".".
1752
1753 47. The pattern /f.*/8s, when applied to "for" with PCRE_PARTIAL_HARD, gave a
1754 complete match instead of a partial match. This bug was dependent on both
1755 the PCRE_UTF8 and PCRE_DOTALL options being set.
1756
1757 48. For a pattern such as /\babc|\bdef/ pcre_study() was failing to set up the
1758 starting byte set, because \b was not being ignored.
1759
1760
1761 Version 8.12 15-Jan-2011
1762 ------------------------
1763
1764 1. Fixed some typos in the markup of the man pages, and wrote a script that
1765 checks for such things as part of the documentation building process.
1766
1767 2. On a big-endian 64-bit system, pcregrep did not correctly process the
1768 --match-limit and --recursion-limit options (added for 8.11). In
1769 particular, this made one of the standard tests fail. (The integer value
1770 went into the wrong half of a long int.)
1771
1772 3. If the --colour option was given to pcregrep with -v (invert match), it
1773 did strange things, either producing crazy output, or crashing. It should,
1774 of course, ignore a request for colour when reporting lines that do not
1775 match.
1776
1777 4. Another pcregrep bug caused similar problems if --colour was specified with
1778 -M (multiline) and the pattern match finished with a line ending.
1779
1780 5. In pcregrep, when a pattern that ended with a literal newline sequence was
1781 matched in multiline mode, the following line was shown as part of the
1782 match. This seems wrong, so I have changed it.
1783
1784 6. Another pcregrep bug in multiline mode, when --colour was specified, caused
1785 the check for further matches in the same line (so they could be coloured)
1786 to overrun the end of the current line. If another match was found, it was
1787 incorrectly shown (and then shown again when found in the next line).
1788
1789 7. If pcregrep was compiled under Windows, there was a reference to the
1790 function pcregrep_exit() before it was defined. I am assuming this was
1791 the cause of the "error C2371: 'pcregrep_exit' : redefinition;" that was
1792 reported by a user. I've moved the definition above the reference.
1793
1794
1795 Version 8.11 10-Dec-2010
1796 ------------------------
1797
1798 1. (*THEN) was not working properly if there were untried alternatives prior
1799 to it in the current branch. For example, in ((a|b)(*THEN)(*F)|c..) it
1800 backtracked to try for "b" instead of moving to the next alternative branch
1801 at the same level (in this case, to look for "c"). The Perl documentation
1802 is clear that when (*THEN) is backtracked onto, it goes to the "next
1803 alternative in the innermost enclosing group".
1804
1805 2. (*COMMIT) was not overriding (*THEN), as it does in Perl. In a pattern
1806 such as (A(*COMMIT)B(*THEN)C|D) any failure after matching A should
1807 result in overall failure. Similarly, (*COMMIT) now overrides (*PRUNE) and
1808 (*SKIP), (*SKIP) overrides (*PRUNE) and (*THEN), and (*PRUNE) overrides
1809 (*THEN).
1810
1811 3. If \s appeared in a character class, it removed the VT character from
1812 the class, even if it had been included by some previous item, for example
1813 in [\x00-\xff\s]. (This was a bug related to the fact that VT is not part
1814 of \s, but is part of the POSIX "space" class.)
1815
1816 4. A partial match never returns an empty string (because you can always
1817 match an empty string at the end of the subject); however the checking for
1818 an empty string was starting at the "start of match" point. This has been
1819 changed to the "earliest inspected character" point, because the returned
1820 data for a partial match starts at this character. This means that, for
1821 example, /(?<=abc)def/ gives a partial match for the subject "abc"
1822 (previously it gave "no match").
1823
1824 5. Changes have been made to the way PCRE_PARTIAL_HARD affects the matching
1825 of $, \z, \Z, \b, and \B. If the match point is at the end of the string,
1826 previously a full match would be given. However, setting PCRE_PARTIAL_HARD
1827 has an implication that the given string is incomplete (because a partial
1828 match is preferred over a full match). For this reason, these items now
1829 give a partial match in this situation. [Aside: previously, the one case
1830 /t\b/ matched against "cat" with PCRE_PARTIAL_HARD set did return a partial
1831 match rather than a full match, which was wrong by the old rules, but is
1832 now correct.]
1833
1834 6. There was a bug in the handling of #-introduced comments, recognized when
1835 PCRE_EXTENDED is set, when PCRE_NEWLINE_ANY and PCRE_UTF8 were also set.
1836 If a UTF-8 multi-byte character included the byte 0x85 (e.g. +U0445, whose
1837 UTF-8 encoding is 0xd1,0x85), this was misinterpreted as a newline when
1838 scanning for the end of the comment. (*Character* 0x85 is an "any" newline,
1839 but *byte* 0x85 is not, in UTF-8 mode). This bug was present in several
1840 places in pcre_compile().
1841
1842 7. Related to (6) above, when pcre_compile() was skipping #-introduced
1843 comments when looking ahead for named forward references to subpatterns,
1844 the only newline sequence it recognized was NL. It now handles newlines
1845 according to the set newline convention.
1846
1847 8. SunOS4 doesn't have strerror() or strtoul(); pcregrep dealt with the
1848 former, but used strtoul(), whereas pcretest avoided strtoul() but did not
1849 cater for a lack of strerror(). These oversights have been fixed.
1850
1851 9. Added --match-limit and --recursion-limit to pcregrep.
1852
1853 10. Added two casts needed to build with Visual Studio when NO_RECURSE is set.
1854
1855 11. When the -o option was used, pcregrep was setting a return code of 1, even
1856 when matches were found, and --line-buffered was not being honoured.
1857
1858 12. Added an optional parentheses number to the -o and --only-matching options
1859 of pcregrep.
1860
1861 13. Imitating Perl's /g action for multiple matches is tricky when the pattern
1862 can match an empty string. The code to do it in pcretest and pcredemo
1863 needed fixing:
1864
1865 (a) When the newline convention was "crlf", pcretest got it wrong, skipping
1866 only one byte after an empty string match just before CRLF (this case
1867 just got forgotten; "any" and "anycrlf" were OK).
1868
1869 (b) The pcretest code also had a bug, causing it to loop forever in UTF-8
1870 mode when an empty string match preceded an ASCII character followed by
1871 a non-ASCII character. (The code for advancing by one character rather
1872 than one byte was nonsense.)
1873
1874 (c) The pcredemo.c sample program did not have any code at all to handle
1875 the cases when CRLF is a valid newline sequence.
1876
1877 14. Neither pcre_exec() nor pcre_dfa_exec() was checking that the value given
1878 as a starting offset was within the subject string. There is now a new
1879 error, PCRE_ERROR_BADOFFSET, which is returned if the starting offset is
1880 negative or greater than the length of the string. In order to test this,
1881 pcretest is extended to allow the setting of negative starting offsets.
1882
1883 15. In both pcre_exec() and pcre_dfa_exec() the code for checking that the
1884 starting offset points to the beginning of a UTF-8 character was
1885 unnecessarily clumsy. I tidied it up.
1886
1887 16. Added PCRE_ERROR_SHORTUTF8 to make it possible to distinguish between a
1888 bad UTF-8 sequence and one that is incomplete when using PCRE_PARTIAL_HARD.
1889
1890 17. Nobody had reported that the --include_dir option, which was added in
1891 release 7.7 should have been called --include-dir (hyphen, not underscore)
1892 for compatibility with GNU grep. I have changed it to --include-dir, but
1893 left --include_dir as an undocumented synonym, and the same for
1894 --exclude-dir, though that is not available in GNU grep, at least as of
1895 release 2.5.4.
1896
1897 18. At a user's suggestion, the macros GETCHAR and friends (which pick up UTF-8
1898 characters from a string of bytes) have been redefined so as not to use
1899 loops, in order to improve performance in some environments. At the same
1900 time, I abstracted some of the common code into auxiliary macros to save
1901 repetition (this should not affect the compiled code).
1902
1903 19. If \c was followed by a multibyte UTF-8 character, bad things happened. A
1904 compile-time error is now given if \c is not followed by an ASCII
1905 character, that is, a byte less than 128. (In EBCDIC mode, the code is
1906 different, and any byte value is allowed.)
1907
1908 20. Recognize (*NO_START_OPT) at the start of a pattern to set the PCRE_NO_
1909 START_OPTIMIZE option, which is now allowed at compile time - but just
1910 passed through to pcre_exec() or pcre_dfa_exec(). This makes it available
1911 to pcregrep and other applications that have no direct access to PCRE
1912 options. The new /Y option in pcretest sets this option when calling
1913 pcre_compile().
1914
1915 21. Change 18 of release 8.01 broke the use of named subpatterns for recursive
1916 back references. Groups containing recursive back references were forced to
1917 be atomic by that change, but in the case of named groups, the amount of
1918 memory required was incorrectly computed, leading to "Failed: internal
1919 error: code overflow". This has been fixed.
1920
1921 22. Some patches to pcre_stringpiece.h, pcre_stringpiece_unittest.cc, and
1922 pcretest.c, to avoid build problems in some Borland environments.
1923
1924
1925 Version 8.10 25-Jun-2010
1926 ------------------------
1927
1928 1. Added support for (*MARK:ARG) and for ARG additions to PRUNE, SKIP, and
1929 THEN.
1930
1931 2. (*ACCEPT) was not working when inside an atomic group.
1932
1933 3. Inside a character class, \B is treated as a literal by default, but
1934 faulted if PCRE_EXTRA is set. This mimics Perl's behaviour (the -w option
1935 causes the error). The code is unchanged, but I tidied the documentation.
1936
1937 4. Inside a character class, PCRE always treated \R and \X as literals,
1938 whereas Perl faults them if its -w option is set. I have changed PCRE so
1939 that it faults them when PCRE_EXTRA is set.
1940
1941 5. Added support for \N, which always matches any character other than
1942 newline. (It is the same as "." when PCRE_DOTALL is not set.)
1943
1944 6. When compiling pcregrep with newer versions of gcc which may have
1945 FORTIFY_SOURCE set, several warnings "ignoring return value of 'fwrite',
1946 declared with attribute warn_unused_result" were given. Just casting the
1947 result to (void) does not stop the warnings; a more elaborate fudge is
1948 needed. I've used a macro to implement this.
1949
1950 7. Minor change to pcretest.c to avoid a compiler warning.
1951
1952 8. Added four artifical Unicode properties to help with an option to make
1953 \s etc use properties (see next item). The new properties are: Xan
1954 (alphanumeric), Xsp (Perl space), Xps (POSIX space), and Xwd (word).
1955
1956 9. Added PCRE_UCP to make \b, \d, \s, \w, and certain POSIX character classes
1957 use Unicode properties. (*UCP) at the start of a pattern can be used to set
1958 this option. Modified pcretest to add /W to test this facility. Added
1959 REG_UCP to make it available via the POSIX interface.
1960
1961 10. Added --line-buffered to pcregrep.
1962
1963 11. In UTF-8 mode, if a pattern that was compiled with PCRE_CASELESS was
1964 studied, and the match started with a letter with a code point greater than
1965 127 whose first byte was different to the first byte of the other case of
1966 the letter, the other case of this starting letter was not recognized
1967 (#976).
1968
1969 12. If a pattern that was studied started with a repeated Unicode property
1970 test, for example, \p{Nd}+, there was the theoretical possibility of
1971 setting up an incorrect bitmap of starting bytes, but fortunately it could
1972 not have actually happened in practice until change 8 above was made (it
1973 added property types that matched character-matching opcodes).
1974
1975 13. pcre_study() now recognizes \h, \v, and \R when constructing a bit map of
1976 possible starting bytes for non-anchored patterns.
1977
1978 14. Extended the "auto-possessify" feature of pcre_compile(). It now recognizes
1979 \R, and also a number of cases that involve Unicode properties, both
1980 explicit and implicit when PCRE_UCP is set.
1981
1982 15. If a repeated Unicode property match (e.g. \p{Lu}*) was used with non-UTF-8
1983 input, it could crash or give wrong results if characters with values
1984 greater than 0xc0 were present in the subject string. (Detail: it assumed
1985 UTF-8 input when processing these items.)
1986
1987 16. Added a lot of (int) casts to avoid compiler warnings in systems where
1988 size_t is 64-bit (#991).
1989
1990 17. Added a check for running out of memory when PCRE is compiled with
1991 --disable-stack-for-recursion (#990).
1992
1993 18. If the last data line in a file for pcretest does not have a newline on
1994 the end, a newline was missing in the output.
1995
1996 19. The default pcre_chartables.c file recognizes only ASCII characters (values
1997 less than 128) in its various bitmaps. However, there is a facility for
1998 generating tables according to the current locale when PCRE is compiled. It
1999 turns out that in some environments, 0x85 and 0xa0, which are Unicode space
2000 characters, are recognized by isspace() and therefore were getting set in
2001 these tables, and indeed these tables seem to approximate to ISO 8859. This
2002 caused a problem in UTF-8 mode when pcre_study() was used to create a list
2003 of bytes that can start a match. For \s, it was including 0x85 and 0xa0,
2004 which of course cannot start UTF-8 characters. I have changed the code so
2005 that only real ASCII characters (less than 128) and the correct starting
2006 bytes for UTF-8 encodings are set for characters greater than 127 when in
2007 UTF-8 mode. (When PCRE_UCP is set - see 9 above - the code is different
2008 altogether.)
2009
2010 20. Added the /T option to pcretest so as to be able to run tests with non-
2011 standard character tables, thus making it possible to include the tests
2012 used for 19 above in the standard set of tests.
2013
2014 21. A pattern such as (?&t)(?#()(?(DEFINE)(?<t>a)) which has a forward
2015 reference to a subpattern the other side of a comment that contains an
2016 opening parenthesis caused either an internal compiling error, or a
2017 reference to the wrong subpattern.
2018
2019
2020 Version 8.02 19-Mar-2010
2021 ------------------------
2022
2023 1. The Unicode data tables have been updated to Unicode 5.2.0.
2024
2025 2. Added the option --libs-cpp to pcre-config, but only when C++ support is
2026 configured.
2027
2028 3. Updated the licensing terms in the pcregexp.pas file, as agreed with the
2029 original author of that file, following a query about its status.
2030
2031 4. On systems that do not have stdint.h (e.g. Solaris), check for and include
2032 inttypes.h instead. This fixes a bug that was introduced by change 8.01/8.
2033
2034 5. A pattern such as (?&t)*+(?(DEFINE)(?<t>.)) which has a possessive
2035 quantifier applied to a forward-referencing subroutine call, could compile
2036 incorrect code or give the error "internal error: previously-checked
2037 referenced subpattern not found".
2038
2039 6. Both MS Visual Studio and Symbian OS have problems with initializing
2040 variables to point to external functions. For these systems, therefore,
2041 pcre_malloc etc. are now initialized to local functions that call the
2042 relevant global functions.
2043
2044 7. There were two entries missing in the vectors called coptable and poptable
2045 in pcre_dfa_exec.c. This could lead to memory accesses outsize the vectors.
2046 I've fixed the data, and added a kludgy way of testing at compile time that
2047 the lengths are correct (equal to the number of opcodes).
2048
2049 8. Following on from 7, I added a similar kludge to check the length of the
2050 eint vector in pcreposix.c.
2051
2052 9. Error texts for pcre_compile() are held as one long string to avoid too
2053 much relocation at load time. To find a text, the string is searched,
2054 counting zeros. There was no check for running off the end of the string,
2055 which could happen if a new error number was added without updating the
2056 string.
2057
2058 10. \K gave a compile-time error if it appeared in a lookbehind assersion.
2059
2060 11. \K was not working if it appeared in an atomic group or in a group that
2061 was called as a "subroutine", or in an assertion. Perl 5.11 documents that
2062 \K is "not well defined" if used in an assertion. PCRE now accepts it if
2063 the assertion is positive, but not if it is negative.
2064
2065 12. Change 11 fortuitously reduced the size of the stack frame used in the
2066 "match()" function of pcre_exec.c by one pointer. Forthcoming
2067 implementation of support for (*MARK) will need an extra pointer on the
2068 stack; I have reserved it now, so that the stack frame size does not
2069 decrease.
2070
2071 13. A pattern such as (?P<L1>(?P<L2>0)|(?P>L2)(?P>L1)) in which the only other
2072 item in branch that calls a recursion is a subroutine call - as in the
2073 second branch in the above example - was incorrectly given the compile-
2074 time error "recursive call could loop indefinitely" because pcre_compile()
2075 was not correctly checking the subroutine for matching a non-empty string.
2076
2077 14. The checks for overrunning compiling workspace could trigger after an
2078 overrun had occurred. This is a "should never occur" error, but it can be
2079 triggered by pathological patterns such as hundreds of nested parentheses.
2080 The checks now trigger 100 bytes before the end of the workspace.
2081
2082 15. Fix typo in configure.ac: "srtoq" should be "strtoq".
2083
2084
2085 Version 8.01 19-Jan-2010
2086 ------------------------
2087
2088 1. If a pattern contained a conditional subpattern with only one branch (in
2089 particular, this includes all (*DEFINE) patterns), a call to pcre_study()
2090 computed the wrong minimum data length (which is of course zero for such
2091 subpatterns). This could cause incorrect "no match" results.
2092
2093 2. For patterns such as (?i)a(?-i)b|c where an option setting at the start of
2094 the pattern is reset in the first branch, pcre_compile() failed with
2095 "internal error: code overflow at offset...". This happened only when
2096 the reset was to the original external option setting. (An optimization
2097 abstracts leading options settings into an external setting, which was the
2098 cause of this.)
2099
2100 3. A pattern such as ^(?!a(*SKIP)b) where a negative assertion contained one
2101 of the verbs SKIP, PRUNE, or COMMIT, did not work correctly. When the
2102 assertion pattern did not match (meaning that the assertion was true), it
2103 was incorrectly treated as false if the SKIP had been reached during the
2104 matching. This also applied to assertions used as conditions.
2105
2106 4. If an item that is not supported by pcre_dfa_exec() was encountered in an
2107 assertion subpattern, including such a pattern used as a condition,
2108 unpredictable results occurred, instead of the error return
2109 PCRE_ERROR_DFA_UITEM.
2110
2111 5. The C++ GlobalReplace function was not working like Perl for the special
2112 situation when an empty string is matched. It now does the fancy magic
2113 stuff that is necessary.
2114
2115 6. In pcre_internal.h, obsolete includes to setjmp.h and stdarg.h have been
2116 removed. (These were left over from very, very early versions of PCRE.)
2117
2118 7. Some cosmetic changes to the code to make life easier when compiling it
2119 as part of something else:
2120
2121 (a) Change DEBUG to PCRE_DEBUG.
2122
2123 (b) In pcre_compile(), rename the member of the "branch_chain" structure
2124 called "current" as "current_branch", to prevent a collision with the
2125 Linux macro when compiled as a kernel module.
2126
2127 (c) In pcre_study(), rename the function set_bit() as set_table_bit(), to
2128 prevent a collision with the Linux macro when compiled as a kernel
2129 module.
2130
2131 8. In pcre_compile() there are some checks for integer overflows that used to
2132 cast potentially large values to (double). This has been changed to that
2133 when building, a check for int64_t is made, and if it is found, it is used
2134 instead, thus avoiding the use of floating point arithmetic. (There is no
2135 other use of FP in PCRE.) If int64_t is not found, the fallback is to
2136 double.
2137
2138 9. Added two casts to avoid signed/unsigned warnings from VS Studio Express
2139 2005 (difference between two addresses compared to an unsigned value).
2140
2141 10. Change the standard AC_CHECK_LIB test for libbz2 in configure.ac to a
2142 custom one, because of the following reported problem in Windows:
2143
2144 - libbz2 uses the Pascal calling convention (WINAPI) for the functions
2145 under Win32.
2146 - The standard autoconf AC_CHECK_LIB fails to include "bzlib.h",
2147 therefore missing the function definition.
2148 - The compiler thus generates a "C" signature for the test function.
2149 - The linker fails to find the "C" function.
2150 - PCRE fails to configure if asked to do so against libbz2.
2151
2152 11. When running libtoolize from libtool-2.2.6b as part of autogen.sh, these
2153 messages were output:
2154
2155 Consider adding `AC_CONFIG_MACRO_DIR([m4])' to configure.ac and
2156 rerunning libtoolize, to keep the correct libtool macros in-tree.
2157 Consider adding `-I m4' to ACLOCAL_AMFLAGS in Makefile.am.
2158
2159 I have done both of these things.
2160
2161 12. Although pcre_dfa_exec() does not use nearly as much stack as pcre_exec()
2162 most of the time, it *can* run out if it is given a pattern that contains a
2163 runaway infinite recursion. I updated the discussion in the pcrestack man
2164 page.
2165
2166 13. Now that we have gone to the x.xx style of version numbers, the minor
2167 version may start with zero. Using 08 or 09 is a bad idea because users
2168 might check the value of PCRE_MINOR in their code, and 08 or 09 may be
2169 interpreted as invalid octal numbers. I've updated the previous comment in
2170 configure.ac, and also added a check that gives an error if 08 or 09 are
2171 used.
2172
2173 14. Change 8.00/11 was not quite complete: code had been accidentally omitted,
2174 causing partial matching to fail when the end of the subject matched \W
2175 in a UTF-8 pattern where \W was quantified with a minimum of 3.
2176
2177 15. There were some discrepancies between the declarations in pcre_internal.h
2178 of _pcre_is_newline(), _pcre_was_newline(), and _pcre_valid_utf8() and
2179 their definitions. The declarations used "const uschar *" and the
2180 definitions used USPTR. Even though USPTR is normally defined as "const
2181 unsigned char *" (and uschar is typedeffed as "unsigned char"), it was
2182 reported that: "This difference in casting confuses some C++ compilers, for
2183 example, SunCC recognizes above declarations as different functions and
2184 generates broken code for hbpcre." I have changed the declarations to use
2185 USPTR.
2186
2187 16. GNU libtool is named differently on some systems. The autogen.sh script now
2188 tries several variants such as glibtoolize (MacOSX) and libtoolize1x
2189 (FreeBSD).
2190
2191 17. Applied Craig's patch that fixes an HP aCC compile error in pcre 8.00
2192 (strtoXX undefined when compiling pcrecpp.cc). The patch contains this
2193 comment: "Figure out how to create a longlong from a string: strtoll and
2194 equivalent. It's not enough to call AC_CHECK_FUNCS: hpux has a strtoll, for
2195 instance, but it only takes 2 args instead of 3!"
2196
2197 18. A subtle bug concerned with back references has been fixed by a change of
2198 specification, with a corresponding code fix. A pattern such as
2199 ^(xa|=?\1a)+$ which contains a back reference inside the group to which it
2200 refers, was giving matches when it shouldn't. For example, xa=xaaa would
2201 match that pattern. Interestingly, Perl (at least up to 5.11.3) has the
2202 same bug. Such groups have to be quantified to be useful, or contained
2203 inside another quantified group. (If there's no repetition, the reference
2204 can never match.) The problem arises because, having left the group and
2205 moved on to the rest of the pattern, a later failure that backtracks into
2206 the group uses the captured value from the final iteration of the group
2207 rather than the correct earlier one. I have fixed this in PCRE by forcing
2208 any group that contains a reference to itself to be an atomic group; that
2209 is, there cannot be any backtracking into it once it has completed. This is
2210 similar to recursive and subroutine calls.
2211
2212
2213 Version 8.00 19-Oct-09
2214 ----------------------
2215
2216 1. The table for translating pcre_compile() error codes into POSIX error codes
2217 was out-of-date, and there was no check on the pcre_compile() error code
2218 being within the table. This could lead to an OK return being given in
2219 error.
2220
2221 2. Changed the call to open a subject file in pcregrep from fopen(pathname,
2222 "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
2223 in a Windows environment.
2224
2225 3. The pcregrep --count option prints the count for each file even when it is
2226 zero, as does GNU grep. However, pcregrep was also printing all files when
2227 --files-with-matches was added. Now, when both options are given, it prints
2228 counts only for those files that have at least one match. (GNU grep just
2229 prints the file name in this circumstance, but including the count seems
2230 more useful - otherwise, why use --count?) Also ensured that the
2231 combination -clh just lists non-zero counts, with no names.
2232
2233 4. The long form of the pcregrep -F option was incorrectly implemented as
2234 --fixed_strings instead of --fixed-strings. This is an incompatible change,
2235 but it seems right to fix it, and I didn't think it was worth preserving
2236 the old behaviour.
2237
2238 5. The command line items --regex=pattern and --regexp=pattern were not
2239 recognized by pcregrep, which required --regex pattern or --regexp pattern
2240 (with a space rather than an '='). The man page documented the '=' forms,
2241 which are compatible with GNU grep; these now work.
2242
2243 6. No libpcreposix.pc file was created for pkg-config; there was just
2244 libpcre.pc and libpcrecpp.pc. The omission has been rectified.
2245
2246 7. Added #ifndef SUPPORT_UCP into the pcre_ucd.c module, to reduce its size
2247 when UCP support is not needed, by modifying the Python script that
2248 generates it from Unicode data files. This should not matter if the module
2249 is correctly used as a library, but I received one complaint about 50K of
2250 unwanted data. My guess is that the person linked everything into his
2251 program rather than using a library. Anyway, it does no harm.
2252
2253 8. A pattern such as /\x{123}{2,2}+/8 was incorrectly compiled; the trigger
2254 was a minimum greater than 1 for a wide character in a possessive
2255 repetition. The same bug could also affect patterns like /(\x{ff}{0,2})*/8
2256 which had an unlimited repeat of a nested, fixed maximum repeat of a wide
2257 character. Chaos in the form of incorrect output or a compiling loop could
2258 result.
2259
2260 9. The restrictions on what a pattern can contain when partial matching is
2261 requested for pcre_exec() have been removed. All patterns can now be
2262 partially matched by this function. In addition, if there are at least two
2263 slots in the offset vector, the offset of the earliest inspected character
2264 for the match and the offset of the end of the subject are set in them when
2265 PCRE_ERROR_PARTIAL is returned.
2266
2267 10. Partial matching has been split into two forms: PCRE_PARTIAL_SOFT, which is
2268 synonymous with PCRE_PARTIAL, for backwards compatibility, and
2269 PCRE_PARTIAL_HARD, which causes a partial match to supersede a full match,
2270 and may be more useful for multi-segment matching.
2271
2272 11. Partial matching with pcre_exec() is now more intuitive. A partial match
2273 used to be given if ever the end of the subject was reached; now it is
2274 given only if matching could not proceed because another character was
2275 needed. This makes a difference in some odd cases such as Z(*FAIL) with the
2276 string "Z", which now yields "no match" instead of "partial match". In the
2277 case of pcre_dfa_exec(), "no match" is given if every matching path for the
2278 final character ended with (*FAIL).
2279
2280 12. Restarting a match using pcre_dfa_exec() after a partial match did not work
2281 if the pattern had a "must contain" character that was already found in the
2282 earlier partial match, unless partial matching was again requested. For
2283 example, with the pattern /dog.(body)?/, the "must contain" character is
2284 "g". If the first part-match was for the string "dog", restarting with
2285 "sbody" failed. This bug has been fixed.
2286
2287 13. The string returned by pcre_dfa_exec() after a partial match has been
2288 changed so that it starts at the first inspected character rather than the
2289 first character of the match. This makes a difference only if the pattern
2290 starts with a lookbehind assertion or \b or \B (\K is not supported by
2291 pcre_dfa_exec()). It's an incompatible change, but it makes the two
2292 matching functions compatible, and I think it's the right thing to do.
2293
2294 14. Added a pcredemo man page, created automatically from the pcredemo.c file,
2295 so that the demonstration program is easily available in environments where
2296 PCRE has not been installed from source.
2297
2298 15. Arranged to add -DPCRE_STATIC to cflags in libpcre.pc, libpcreposix.cp,
2299 libpcrecpp.pc and pcre-config when PCRE is not compiled as a shared
2300 library.
2301
2302 16. Added REG_UNGREEDY to the pcreposix interface, at the request of a user.
2303 It maps to PCRE_UNGREEDY. It is not, of course, POSIX-compatible, but it
2304 is not the first non-POSIX option to be added. Clearly some people find
2305 these options useful.
2306
2307 17. If a caller to the POSIX matching function regexec() passes a non-zero
2308 value for nmatch with a NULL value for pmatch, the value of
2309 nmatch is forced to zero.
2310
2311 18. RunGrepTest did not have a test for the availability of the -u option of
2312 the diff command, as RunTest does. It now checks in the same way as
2313 RunTest, and also checks for the -b option.
2314
2315 19. If an odd number of negated classes containing just a single character
2316 interposed, within parentheses, between a forward reference to a named
2317 subpattern and the definition of the subpattern, compilation crashed with
2318 an internal error, complaining that it could not find the referenced
2319 subpattern. An example of a crashing pattern is /(?&A)(([^m])(?<A>))/.
2320 [The bug was that it was starting one character too far in when skipping
2321 over the character class, thus treating the ] as data rather than
2322 terminating the class. This meant it could skip too much.]
2323
2324 20. Added PCRE_NOTEMPTY_ATSTART in order to be able to correctly implement the
2325 /g option in pcretest when the pattern contains \K, which makes it possible
2326 to have an empty string match not at the start, even when the pattern is
2327 anchored. Updated pcretest and pcredemo to use this option.
2328
2329 21. If the maximum number of capturing subpatterns in a recursion was greater
2330 than the maximum at the outer level, the higher number was returned, but
2331 with unset values at the outer level. The correct (outer level) value is
2332 now given.
2333
2334 22. If (*ACCEPT) appeared inside capturing parentheses, previous releases of
2335 PCRE did not set those parentheses (unlike Perl). I have now found a way to
2336 make it do so. The string so far is captured, making this feature
2337 compatible with Perl.
2338
2339 23. The tests have been re-organized, adding tests 11 and 12, to make it
2340 possible to check the Perl 5.10 features against Perl 5.10.
2341
2342 24. Perl 5.10 allows subroutine calls in lookbehinds, as long as the subroutine
2343 pattern matches a fixed length string. PCRE did not allow this; now it
2344 does. Neither allows recursion.
2345
2346 25. I finally figured out how to implement a request to provide the minimum
2347 length of subject string that was needed in order to match a given pattern.
2348 (It was back references and recursion that I had previously got hung up
2349 on.) This code has now been added to pcre_study(); it finds a lower bound
2350 to the length of subject needed. It is not necessarily the greatest lower
2351 bound, but using it to avoid searching strings that are too short does give
2352 some useful speed-ups. The value is available to calling programs via
2353 pcre_fullinfo().
2354
2355 26. While implementing 25, I discovered to my embarrassment that pcretest had
2356 not been passing the result of pcre_study() to pcre_dfa_exec(), so the
2357 study optimizations had never been tested with that matching function.
2358 Oops. What is worse, even when it was passed study data, there was a bug in
2359 pcre_dfa_exec() that meant it never actually used it. Double oops. There
2360 were also very few tests of studied patterns with pcre_dfa_exec().
2361
2362 27. If (?| is used to create subpatterns with duplicate numbers, they are now
2363 allowed to have the same name, even if PCRE_DUPNAMES is not set. However,
2364 on the other side of the coin, they are no longer allowed to have different
2365 names, because these cannot be distinguished in PCRE, and this has caused
2366 confusion. (This is a difference from Perl.)
2367
2368 28. When duplicate subpattern names are present (necessarily with different
2369 numbers, as required by 27 above), and a test is made by name in a
2370 conditional pattern, either for a subpattern having been matched, or for
2371 recursion in such a pattern, all the associated numbered subpatterns are
2372 tested, and the overall condition is true if the condition is true for any
2373 one of them. This is the way Perl works, and is also more like the way
2374 testing by number works.
2375
2376
2377 Version 7.9 11-Apr-09
2378 ---------------------
2379
2380 1. When building with support for bzlib/zlib (pcregrep) and/or readline
2381 (pcretest), all targets were linked against these libraries. This included
2382 libpcre, libpcreposix, and libpcrecpp, even though they do not use these
2383 libraries. This caused unwanted dependencies to be created. This problem
2384 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
2385 pcretest is linked with readline.
2386
2387 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
2388 "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
2389 moved outside it again, because FALSE and TRUE are already defined in AIX,
2390 but BOOL is not.
2391
2392 3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
2393 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
2394
2395 4. The pcregrep documentation said spaces were inserted as well as colons (or
2396 hyphens) following file names and line numbers when outputting matching
2397 lines. This is not true; no spaces are inserted. I have also clarified the
2398 wording for the --colour (or --color) option.
2399
2400 5. In pcregrep, when --colour was used with -o, the list of matching strings
2401 was not coloured; this is different to GNU grep, so I have changed it to be
2402 the same.
2403
2404 6. When --colo(u)r was used in pcregrep, only the first matching substring in
2405 each matching line was coloured. Now it goes on to look for further matches
2406 of any of the test patterns, which is the same behaviour as GNU grep.
2407
2408 7. A pattern that could match an empty string could cause pcregrep to loop; it
2409 doesn't make sense to accept an empty string match in pcregrep, so I have
2410 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
2411 seems to be how GNU grep behaves. [But see later change 40 for release
2412 8.33.]
2413
2414 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
2415 start or after a newline", because the conditional assertion was not being
2416 correctly handled. The rule now is that both the assertion and what follows
2417 in the first alternative must satisfy the test.
2418
2419 9. If auto-callout was enabled in a pattern with a conditional group whose
2420 condition was an assertion, PCRE could crash during matching, both with
2421 pcre_exec() and pcre_dfa_exec().
2422
2423 10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
2424 used for matching.
2425
2426 11. Unicode property support in character classes was not working for
2427 characters (bytes) greater than 127 when not in UTF-8 mode.
2428
2429 12. Added the -M command line option to pcretest.
2430
2431 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
2432
2433 15. Added the PCRE_NO_START_OPTIMIZE match-time option.
2434
2435 16. Added comments and documentation about mis-use of no_arg in the C++
2436 wrapper.
2437
2438 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
2439 from Martin Jerabek that uses macro names for all relevant character and
2440 string constants.
2441
2442 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
2443 SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
2444 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
2445 these, but not everybody uses configure.
2446
2447 19. A conditional group that had only one branch was not being correctly
2448 recognized as an item that could match an empty string. This meant that an
2449 enclosing group might also not be so recognized, causing infinite looping
2450 (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
2451 with the subject "ab", where knowledge that the repeated group can match
2452 nothing is needed in order to break the loop.
2453
2454 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
2455 exec(), but without supplying a callout function, matching went wrong.
2456
2457 21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
2458 leak if the size of the offset vector was greater than 30. When the vector
2459 is smaller, the saved offsets during recursion go onto a local stack
2460 vector, but for larger vectors malloc() is used. It was failing to free
2461 when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
2462 error, in fact).
2463
2464 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
2465 heapframe that is used only when UTF-8 support is enabled. This caused no
2466 problem, but was untidy.
2467
2468 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
2469 CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
2470 included within another project.
2471
2472 24. Steven Van Ingelgem's patches to add more options to the CMake support,
2473 slightly modified by me:
2474
2475 (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
2476 not building pcregrep.
2477
2478 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
2479 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
2480
2481 25. Forward references, both numeric and by name, in patterns that made use of
2482 duplicate group numbers, could behave incorrectly or give incorrect errors,
2483 because when scanning forward to find the reference group, PCRE was not
2484 taking into account the duplicate group numbers. A pattern such as
2485 ^X(?3)(a)(?|(b)|(q))(Y) is an example.
2486
2487 26. Changed a few more instances of "const unsigned char *" to USPTR, making
2488 the feature of a custom pointer more persuasive (as requested by a user).
2489
2490 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
2491 pcretest.c, inside #ifndefs, because it seems they are sometimes already
2492 pre-defined.
2493
2494 28. Added support for (*UTF8) at the start of a pattern.
2495
2496 29. Arrange for flags added by the "release type" setting in CMake to be shown
2497 in the configuration summary.
2498
2499
2500 Version 7.8 05-Sep-08
2501 ---------------------
2502
2503 1. Replaced UCP searching code with optimized version as implemented for Ad
2504 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
2505 stage table and inline lookup instead of a function, giving speed ups of 2
2506 to 5 times on some simple patterns that I tested. Permission was given to
2507 distribute the MultiStage2.py script that generates the tables (it's not in
2508 the tarball, but is in the Subversion repository).
2509
2510 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
2511 scripts.
2512
2513 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
2514 a group with a zero qualifier. The result of the study could be incorrect,
2515 or the function might crash, depending on the pattern.
2516
2517 4. Caseless matching was not working for non-ASCII characters in back
2518 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
2519 It now works when Unicode Property Support is available.
2520
2521 5. In pcretest, an escape such as \x{de} in the data was always generating
2522 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
2523 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
2524 truncation.
2525
2526 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
2527
2528 7. Added two (int) casts to pcregrep when printing the difference of two
2529 pointers, in case they are 64-bit values.
2530
2531 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
2532 test 2 if it fails.
2533
2534 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
2535 and a #define of that name to empty if it is not externally set. This is to
2536 allow users of MSVC to set it if necessary.
2537
2538 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
2539 the convenience functions in the pcre_get.c source file.
2540
2541 11. An option change at the start of a pattern that had top-level alternatives
2542 could cause overwriting and/or a crash. This command provoked a crash in
2543 some environments:
2544
2545 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
2546
2547 This potential security problem was recorded as CVE-2008-2371.
2548
2549 12. For a pattern where the match had to start at the beginning or immediately
2550 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
2551 pcre_dfa_exec() could read past the end of the passed subject if there was
2552 no match. To help with detecting such bugs (e.g. with valgrind), I modified
2553 pcretest so that it places the subject at the end of its malloc-ed buffer.
2554
2555 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
2556 exec() might read past the end of the data buffer in UTF-8 mode.
2557
2558 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
2559 the data contained the byte 0x85 as part of a UTF-8 character within its
2560 first line. This applied both to normal and DFA matching.
2561
2562 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
2563 /^[^d]*?$/8 failed to match "abc".
2564
2565 16. Added a missing copyright notice to pcrecpp_internal.h.
2566
2567 17. Make it more clear in the documentation that values returned from
2568 pcre_exec() in ovector are byte offsets, not character counts.
2569
2570 18. Tidied a few places to stop certain compilers from issuing warnings.
2571
2572 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
2573 supplied by Stefan Weber. I made a further small update for 7.8 because
2574 there is a change of source arrangements: the pcre_searchfuncs.c module is
2575 replaced by pcre_ucd.c.
2576
2577
2578 Version 7.7 07-May-08
2579 ---------------------
2580
2581 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
2582 a string to a long long, pretend we don't even have a long long." This is
2583 done by checking for the strtoq, strtoll, and _strtoi64 functions.
2584
2585 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
2586 pre-7.6 versions, which defined a global no_arg variable instead of putting
2587 it in the RE class. (See also #8 below.)
2588
2589 3. Remove a line of dead code, identified by coverity and reported by Nuno
2590 Lopes.
2591
2592 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
2593
2594 (1) The include/exclude patterns were being applied to the whole pathnames
2595 of files, instead of just to the final components.
2596
2597 (2) If there was more than one level of directory, the subdirectories were
2598 skipped unless they satisfied the include/exclude conditions. This is
2599 inconsistent with GNU grep (and could even be seen as contrary to the
2600 pcregrep specification - which I improved to make it absolutely clear).
2601 The action now is always to scan all levels of directory, and just
2602 apply the include/exclude patterns to regular files.
2603
2604 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
2605 --exclude_dir in the tests to avoid scanning .svn directories.
2606
2607 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
2608 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
2609 doesn't support NULs in patterns.
2610
2611 7. Added some missing "const"s to declarations of static tables in
2612 pcre_compile.c and pcre_dfa_exec.c.
2613
2614 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
2615 caused by fix #2 above. (Subsequently also a second patch to fix the
2616 first patch. And a third patch - this was a messy problem.)
2617
2618 9. Applied Craig's patch to remove the use of push_back().
2619
2620 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
2621 matching function regexec().
2622
2623 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
2624 which, however, unlike Perl's \g{...}, are subroutine calls, not back
2625 references. PCRE supports relative numbers with this syntax (I don't think
2626 Oniguruma does).
2627
2628 12. Previously, a group with a zero repeat such as (...){0} was completely
2629 omitted from the compiled regex. However, this means that if the group
2630 was called as a subroutine from elsewhere in the pattern, things went wrong
2631 (an internal error was given). Such groups are now left in the compiled
2632 pattern, with a new opcode that causes them to be skipped at execution
2633 time.
2634
2635 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
2636 to the way PCRE behaves:
2637
2638 (a) A lone ] character is dis-allowed (Perl treats it as data).
2639
2640 (b) A back reference to an unmatched subpattern matches an empty string
2641 (Perl fails the current match path).
2642
2643 (c) A data ] in a character class must be notated as \] because if the
2644 first data character in a class is ], it defines an empty class. (In
2645 Perl it is not possible to have an empty class.) The empty class []
2646 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
2647 The negative empty class [^] matches any one character, independently
2648 of the DOTALL setting.
2649
2650 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
2651 non-existent subpattern following a character class starting with ']' and
2652 containing () gave an internal compiling error instead of "reference to
2653 non-existent subpattern". Fortunately, when the pattern did exist, the
2654 compiled code was correct. (When scanning forwards to check for the
2655 existence of the subpattern, it was treating the data ']' as terminating
2656 the class, so got the count wrong. When actually compiling, the reference
2657 was subsequently set up correctly.)
2658
2659 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
2660 it was being rejected as not supported by pcre_dfa_exec(), even though
2661 other assertions are supported. I have made pcre_dfa_exec() support
2662 (*FAIL).
2663
2664 16. The implementation of 13c above involved the invention of a new opcode,
2665 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
2666 cannot be changed at match time, I realized I could make a small
2667 improvement to matching performance by compiling OP_ALLANY instead of
2668 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
2669 on the OP_ANY path.
2670
2671 17. Compiling pcretest on Windows with readline support failed without the
2672 following two fixes: (1) Make the unistd.h include conditional on
2673 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
2674
2675 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
2676 ncurses library to be included for pcretest when ReadLine support is
2677 requested, but also to allow for it to be overridden. This patch came from
2678 Daniel Bergström.
2679
2680 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
2681 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
2682 any errors with the current Unicode tables. Thanks to Peter Kankowski for
2683 spotting this.
2684
2685
2686 Version 7.6 28-Jan-08
2687 ---------------------
2688
2689 1. A character class containing a very large number of characters with
2690 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
2691 overflow.
2692
2693 2. Patch to cut out the "long long" test in pcrecpp_unittest when
2694 HAVE_LONG_LONG is not defined.
2695
2696 3. Applied Christian Ehrlicher's patch to update the CMake build files to
2697 bring them up to date and include new features. This patch includes:
2698
2699 - Fixed PH's badly added libz and libbz2 support.
2700 - Fixed a problem with static linking.
2701 - Added pcredemo. [But later removed - see 7 below.]
2702 - Fixed dftables problem and added an option.
2703 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
2704 HAVE_LONG_LONG.
2705 - Added readline support for pcretest.
2706 - Added an listing of the option settings after cmake has run.
2707
2708 4. A user submitted a patch to Makefile that makes it easy to create
2709 "pcre.dll" under mingw when using Configure/Make. I added stuff to
2710 Makefile.am that cause it to include this special target, without
2711 affecting anything else. Note that the same mingw target plus all
2712 the other distribution libraries and programs are now supported
2713 when configuring with CMake (see 6 below) instead of with
2714 Configure/Make.
2715
2716 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
2717 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
2718 exported in the Windows port". It has not yet been confirmed that the patch
2719 solves the problem, but it does no harm.
2720
2721 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
2722 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
2723 with CMake, and also correct the comment about stack recursion.
2724
2725 7. Remove the automatic building of pcredemo from the ./configure system and
2726 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
2727 of a program that users should build themselves after PCRE is installed, so
2728 building it automatically is not really right. What is more, it gave
2729 trouble in some build environments.
2730
2731 8. Further tidies to CMakeLists.txt from Sheri and Christian.
2732
2733
2734 Version 7.5 10-Jan-08
2735 ---------------------
2736
2737 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
2738 values in parens when parsing an RE using the C++ wrapper."
2739
2740 2. Negative specials like \S did not work in character classes in UTF-8 mode.
2741 Characters greater than 255 were excluded from the class instead of being
2742 included.
2743
2744 3. The same bug as (2) above applied to negated POSIX classes such as
2745 [:^space:].
2746
2747 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
2748 defined or documented. It seems to have been a typo for PCRE_STATIC, so
2749 I have changed it.
2750
2751 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
2752 first named subpattern) and a construct such as (?&a) would reference the
2753 first named subpattern whose name started with "a" (in other words, the
2754 length check was missing). Both these problems are fixed. "Subpattern name
2755 expected" is now given for (?&) (a zero-length name), and this patch also
2756 makes it give the same error for \k'' (previously it complained that that
2757 was a reference to a non-existent subpattern).
2758
2759 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
2760 this is right because (?- can be followed by option settings as well as by
2761 digits. I have, however, made the messages clearer.
2762
2763 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
2764 than the number used in the conditional) now cause a compile-time error.
2765 This is actually not compatible with Perl, which accepts such patterns, but
2766 treats the conditional as always being FALSE (as PCRE used to), but it
2767 seems to me that giving a diagnostic is better.
2768
2769 8. Change "alphameric" to the more common word "alphanumeric" in comments
2770 and messages.
2771
2772 9. Fix two occurrences of "backslash" in comments that should have been
2773 "backspace".
2774
2775 10. Remove two redundant lines of code that can never be obeyed (their function
2776 was moved elsewhere).
2777
2778 11. The program that makes PCRE's Unicode character property table had a bug
2779 which caused it to generate incorrect table entries for sequences of
2780 characters that have the same character type, but are in different scripts.
2781 It amalgamated them into a single range, with the script of the first of
2782 them. In other words, some characters were in the wrong script. There were
2783 thirteen such cases, affecting characters in the following ranges:
2784
2785 U+002b0 - U+002c1
2786 U+0060c - U+0060d
2787 U+0061e - U+00612
2788 U+0064b - U+0065e
2789 U+0074d - U+0076d
2790 U+01800 - U+01805
2791 U+01d00 - U+01d77
2792 U+01d9b - U+01dbf
2793 U+0200b - U+0200f
2794 U+030fc - U+030fe
2795 U+03260 - U+0327f
2796 U+0fb46 - U+0fbb1
2797 U+10450 - U+1049d
2798
2799 12. The -o option (show only the matching part of a line) for pcregrep was not
2800 compatible with GNU grep in that, if there was more than one match in a
2801 line, it showed only the first of them. It now behaves in the same way as
2802 GNU grep.
2803
2804 13. If the -o and -v options were combined for pcregrep, it printed a blank
2805 line for every non-matching line. GNU grep prints nothing, and pcregrep now
2806 does the same. The return code can be used to tell if there were any
2807 non-matching lines.
2808
2809 14. Added --file-offsets and --line-offsets to pcregrep.
2810
2811 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
2812 infinitely looping recursion. The bug was that positive lookaheads were not
2813 being skipped when checking for a possible empty match (negative lookaheads
2814 and both kinds of lookbehind were skipped).
2815
2816 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
2817 inclusion of <windows.h> to before rather than after the definition of
2818 INVALID_FILE_ATTRIBUTES (patch from David Byron).
2819
2820 17. Specifying a possessive quantifier with a specific limit for a Unicode
2821 character property caused pcre_compile() to compile bad code, which led at
2822 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
2823 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
2824 caused the error; without that there was no problem.
2825
2826 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
2827
2828 19. Added --enable-pcretest-libreadline.
2829
2830 20. In pcrecpp.cc, the variable 'count' was incremented twice in
2831 RE::GlobalReplace(). As a result, the number of replacements returned was
2832 double what it should be. I removed one of the increments, but Craig sent a
2833 later patch that removed the other one (the right fix) and added unit tests
2834 that check the return values (which was not done before).
2835
2836 21. Several CMake things:
2837
2838 (1) Arranged that, when cmake is used on Unix, the libraries end up with
2839 the names libpcre and libpcreposix, not just pcre and pcreposix.
2840
2841 (2) The above change means that pcretest and pcregrep are now correctly
2842 linked with the newly-built libraries, not previously installed ones.
2843
2844 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
2845
2846 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
2847 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
2848 UTF-8 newline character). The key issue is that the pattern starts .*;
2849 this means that the match must be either at the beginning, or after a
2850 newline. The bug was in the code for advancing after a failed match and
2851 checking that the new position followed a newline. It was not taking
2852 account of UTF-8 characters correctly.
2853
2854 23. PCRE was behaving differently from Perl in the way it recognized POSIX
2855 character classes. PCRE was not treating the sequence [:...:] as a
2856 character class unless the ... were all letters. Perl, however, seems to
2857 allow any characters between [: and :], though of course it rejects as
2858 unknown any "names" that contain non-letters, because all the known class
2859 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
2860 for example, whereas PCRE did not - it did not recognize a POSIX character
2861 class. This seemed a bit dangerous, so the code has been changed to be
2862 closer to Perl. The behaviour is not identical to Perl, because PCRE will
2863 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
2864 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
2865 Perl does, and where it didn't before.
2866
2867 24. Rewrite so as to remove the single use of %n from pcregrep because in some
2868 Windows environments %n is disabled by default.
2869
2870
2871 Version 7.4 21-Sep-07
2872 ---------------------
2873
2874 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
2875 means that a class such as [\s] counted as "explicit reference to CR or
2876 LF". That isn't really right - the whole point of the change was to try to
2877 help when there was an actual mention of one of the two characters. So now
2878 the change happens only if \r or \n (or a literal CR or LF) character is
2879 encountered.
2880
2881 2. The 32-bit options word was also used for 6 internal flags, but the numbers
2882 of both had grown to the point where there were only 3 bits left.
2883 Fortunately, there was spare space in the data structure, and so I have
2884 moved the internal flags into a new 16-bit field to free up more option
2885 bits.
2886
2887 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
2888 but did not set the internal JCHANGED flag - either of these is enough to
2889 control the way the "get" function works - but the PCRE_INFO_JCHANGED
2890 facility is supposed to tell if (?J) was ever used, so now (?J) at the
2891 start sets both bits.
2892
2893 4. Added options (at build time, compile time, exec time) to change \R from
2894 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
2895
2896 5. doc/pcresyntax.html was missing from the distribution.
2897
2898 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
2899 compatibility, even though it is no longer used.
2900
2901 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
2902 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
2903 windows.h file is present (where different names are used). [This was
2904 reversed later after testing - see 16 below.]
2905
2906 8. Changed all #include <config.h> to #include "config.h". There were also
2907 some further <pcre.h> cases that I changed to "pcre.h".
2908
2909 9. When pcregrep was used with the --colour option, it missed the line ending
2910 sequence off the lines that it output.
2911
2912 10. It was pointed out to me that arrays of string pointers cause lots of
2913 relocations when a shared library is dynamically loaded. A technique of
2914 using a single long string with a table of offsets can drastically reduce
2915 these. I have refactored PCRE in four places to do this. The result is
2916 dramatic:
2917
2918 Originally: 290
2919 After changing UCP table: 187
2920 After changing error message table: 43
2921 After changing table of "verbs" 36
2922 After changing table of Posix names 22
2923
2924 Thanks to the folks working on Gregex for glib for this insight.
2925
2926 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
2927 unicode-properties was also set.
2928
2929 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
2930
2931 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
2932 checked only for CRLF.
2933
2934 14. Added casts to pcretest.c to avoid compiler warnings.
2935
2936 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
2937
2938 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
2939 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
2940 entirely. This removes changes made in 7 above.
2941
2942 17. The CMake files have been updated, and there is now more information about
2943 building with CMake in the NON-UNIX-USE document.
2944
2945
2946 Version 7.3 28-Aug-07
2947 ---------------------
2948
2949 1. In the rejigging of the build system that eventually resulted in 7.1, the
2950 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
2951 brackets there is not right, since it causes compilers to look for an
2952 installed pcre.h, not the version that is in the source that is being
2953 compiled (which of course may be different). I have changed it back to:
2954
2955 #include "pcre.h"
2956
2957 I have a vague recollection that the change was concerned with compiling in
2958 different directories, but in the new build system, that is taken care of
2959 by the VPATH setting the Makefile.
2960
2961 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
2962 when the subject happened to end in the byte 0x85 (e.g. if the last
2963 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
2964 characters but of course it shouldn't be taken as a newline when it is part
2965 of another character. The bug was that, for an unlimited repeat of . in
2966 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
2967 characters when looking for a newline.
2968
2969 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
2970
2971 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
2972 in debug output.
2973
2974 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
2975 long printing in the pcrecpp unittest when running under MinGW.
2976
2977 6. ESC_K was left out of the EBCDIC table.
2978
2979 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
2980 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
2981 limit also applies to "virtual nesting" when a pattern is recursive, and in
2982 this case 1000 isn't so big. I have been able to remove this limit at the
2983 expense of backing off one optimization in certain circumstances. Normally,
2984 when pcre_exec() would call its internal match() function recursively and
2985 immediately return the result unconditionally, it uses a "tail recursion"
2986 feature to save stack. However, when a subpattern that can match an empty
2987 string has an unlimited repetition quantifier, it no longer makes this
2988 optimization. That gives it a stack frame in which to save the data for
2989 checking that an empty string has been matched. Previously this was taken
2990 from the 1000-entry workspace that had been reserved. So now there is no
2991 explicit limit, but more stack is used.
2992
2993 8. Applied Daniel's patches to solve problems with the import/export magic
2994 syntax that is required for Windows, and which was going wrong for the
2995 pcreposix and pcrecpp parts of the library. These were overlooked when this
2996 problem was solved for the main library.
2997
2998 9. There were some crude static tests to avoid integer overflow when computing
2999 the size of patterns that contain repeated groups with explicit upper
3000 limits. As the maximum quantifier is 65535, the maximum group length was
3001 set at 30,000 so that the product of these two numbers did not overflow a
3002 32-bit integer. However, it turns out that people want to use groups that
3003 are longer than 30,000 bytes (though not repeat them that many times).
3004 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
3005 made it possible to implement the integer overflow checks in a much more
3006 dynamic way, which I have now done. The artificial limitation on group
3007 length has been removed - we now have only the limit on the total length of
3008 the compiled pattern, which depends on the LINK_SIZE setting.
3009
3010 10. Fixed a bug in the documentation for get/copy named substring when
3011 duplicate names are permitted. If none of the named substrings are set, the
3012 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
3013 empty string.
3014
3015 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
3016 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
3017 because the ] is interpreted as the first data character and the
3018 terminating ] is not found. PCRE has been made compatible with Perl in this
3019 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
3020 cause memory overwriting.
3021
3022 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
3023 string has been matched (to stop an infinite loop). It was not recognizing
3024 a conditional subpattern that could match an empty string if that
3025 subpattern was within another subpattern. For example, it looped when
3026 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
3027 condition was not nested. This bug has been fixed.
3028
3029 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
3030 past the start of the subject in the presence of bytes with the top bit
3031 set, for example "\x8aBCD".
3032
3033 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
3034 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
3035
3036 14. Optimized (?!) to (*FAIL).
3037
3038 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
3039 This restricts code points to be within the range 0 to 0x10FFFF, excluding
3040 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
3041 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
3042 does: it's just the validity check that is more restrictive.
3043
3044 16. Inserted checks for integer overflows during escape sequence (backslash)
3045 processing, and also fixed erroneous offset values for syntax errors during
3046 backslash processing.
3047
3048 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
3049 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
3050
3051 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
3052 caused an overrun.
3053
3054 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
3055 something other than just ASCII characters) inside a group that had an
3056 unlimited repeat caused a loop at compile time (while checking to see
3057 whether the group could match an empty string).
3058
3059 20. Debugging a pattern containing \p or \P could cause a crash. For example,
3060 [\P{Any}] did so. (Error in the code for printing property names.)
3061
3062 21. An orphan \E inside a character class could cause a crash.
3063
3064 22. A repeated capturing bracket such as (A)? could cause a wild memory
3065 reference during compilation.
3066
3067 23. There are several functions in pcre_compile() that scan along a compiled
3068 expression for various reasons (e.g. to see if it's fixed length for look
3069 behind). There were bugs in these functions when a repeated \p or \P was
3070 present in the pattern. These operators have additional parameters compared
3071 with \d, etc, and these were not being taken into account when moving along
3072 the compiled data. Specifically:
3073
3074 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
3075 length.
3076
3077 (b) An item such as \pL+ within a repeated group could cause crashes or
3078 loops.
3079
3080 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
3081 "reference to non-existent subpattern" error.
3082
3083 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
3084
3085 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
3086 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
3087
3088 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
3089
3090 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
3091 character were causing crashes (broken optimization).
3092
3093 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
3094 \p or \P) caused a compile-time loop.
3095
3096 28. More problems have arisen in unanchored patterns when CRLF is a valid line
3097 break. For example, the unstudied pattern [\r\n]A does not match the string
3098 "\r\nA" because change 7.0/46 below moves the current point on by two
3099 characters after failing to match at the start. However, the pattern \nA
3100 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
3101 the same is true. There doesn't seem any very clean way out of this, but
3102 what I have chosen to do makes the common cases work: PCRE now takes note
3103 of whether there can be an explicit match for \r or \n anywhere in the
3104 pattern, and if so, 7.0/46 no longer applies. As part of this change,
3105 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
3106 pattern has explicit CR or LF references.
3107
3108 29. Added (*CR) etc for changing newline setting at start of pattern.
3109
3110
3111 Version 7.2 19-Jun-07
3112 ---------------------
3113
3114 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
3115 which is apparently normally available under Windows.
3116
3117 2. Re-jig the pcregrep tests with different newline settings in an attempt
3118 to make them independent of the local environment's newline setting.
3119
3120 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
3121
3122 4. Some of the "internals" tests were previously cut out when the link size
3123 was not 2, because the output contained actual offsets. The recent new
3124 "Z" feature of pcretest means that these can be cut out, making the tests
3125 usable with all link sizes.
3126
3127 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
3128 stack recursion. This gives a massive performance boost under BSD, but just
3129 a small improvement under Linux. However, it saves one field in the frame
3130 in all cases.
3131
3132 6. Added more features from the forthcoming Perl 5.10:
3133
3134 (a) (?-n) (where n is a string of digits) is a relative subroutine or
3135 recursion call. It refers to the nth most recently opened parentheses.
3136
3137 (b) (?+n) is also a relative subroutine call; it refers to the nth next
3138 to be opened parentheses.
3139
3140 (c) Conditions that refer to capturing parentheses can be specified
3141 relatively, for example, (?(-2)... or (?(+3)...
3142
3143 (d) \K resets the start of the current match so that everything before
3144 is not part of it.
3145
3146 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
3147
3148 (f) \g{name} is another synonym - part of Perl 5.10's unification of
3149 reference syntax.
3150
3151 (g) (?| introduces a group in which the numbering of parentheses in each
3152 alternative starts with the same number.
3153
3154 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
3155
3156 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
3157 PCRE_INFO_JCHANGED.
3158
3159 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
3160 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
3161 for detecting groups that can match an empty string.
3162
3163 9. A pattern with a very large number of alternatives (more than several
3164 hundred) was running out of internal workspace during the pre-compile
3165 phase, where pcre_compile() figures out how much memory will be needed. A
3166 bit of new cunning has reduced the workspace needed for groups with
3167 alternatives. The 1000-alternative test pattern now uses 12 bytes of
3168 workspace instead of running out of the 4096 that are available.
3169
3170 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
3171
3172 11. Applied patch from Google to remove an optimization that didn't quite work.
3173 The report of the bug said:
3174
3175 pcrecpp::RE("a*").FullMatch("aaa") matches, while
3176 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
3177 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
3178
3179 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
3180 it matched the wrong number of bytes.
3181
3182
3183 Version 7.1 24-Apr-07
3184 ---------------------
3185
3186 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
3187 that is more "standard", making use of automake and other Autotools. There
3188 is some re-arrangement of the files and adjustment of comments consequent
3189 on this.
3190
3191 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
3192 for recursive directory scanning broke on some systems because the files
3193 are not scanned in any specific order and on different systems the order
3194 was different. A call to "sort" has been inserted into RunGrepTest for the
3195 approprate test as a short-term fix. In the longer term there may be an
3196 alternative.
3197
3198 3. I had an email from Eric Raymond about problems translating some of PCRE's
3199 man pages to HTML (despite the fact that I distribute HTML pages, some
3200 people do their own conversions for various reasons). The problems
3201 concerned the use of low-level troff macros .br and .in. I have therefore
3202 removed all such uses from the man pages (some were redundant, some could
3203 be replaced by .nf/.fi pairs). The 132html script that I use to generate
3204 HTML has been updated to handle .nf/.fi and to complain if it encounters
3205 .br or .in.
3206
3207 4. Updated comments in configure.ac that get placed in config.h.in and also
3208 arranged for config.h to be included in the distribution, with the name
3209 config.h.generic, for the benefit of those who have to compile without
3210 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
3211
3212 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
3213 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
3214 makevp.bat for the current PCRE, using the additional files
3215 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
3216
3217 6. A Windows user reported a minor discrepancy with test 2, which turned out
3218 to be caused by a trailing space on an input line that had got lost in his
3219 copy. The trailing space was an accident, so I've just removed it.
3220
3221 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
3222 that is needed.
3223
3224 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
3225 as "const" (a) because they are and (b) because it helps the PHP
3226 maintainers who have recently made a script to detect big data structures
3227 in the php code that should be moved to the .rodata section. I remembered
3228 to update Builducptable as well, so it won't revert if ucptable.h is ever
3229 re-created.
3230
3231 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
3232 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
3233 order to be able to cut out the UTF-8 tables in the latter when UTF-8
3234 support is not required. This saves 1.5-2K of code, which is important in
3235 some applications.
3236
3237 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
3238 so as not to refer to the tables, even though these functions will never be
3239 called when UTF-8 support is disabled. Otherwise there are problems with a
3240 shared library.
3241
3242 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
3243
3244 (a) It was defining its arguments as char * instead of void *.
3245
3246 (b) It was assuming that all moves were upwards in memory; this was true
3247 a long time ago when I wrote it, but is no longer the case.
3248
3249 The emulated memove() is provided for those environments that have neither
3250 memmove() nor bcopy(). I didn't think anyone used it these days, but that
3251 is clearly not the case, as these two bugs were recently reported.
3252
3253 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
3254 and Detrail to create the HTML documentation, the .txt form of the man
3255 pages, and it removes trailing spaces from listed files. It also creates
3256 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
3257 case, it wraps all the #defines with #ifndefs. This script should be run
3258 before "make dist".
3259
3260 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
3261 with Unicode property support.
3262
3263 (a) For a maximizing quantifier, if the two different cases of the
3264 character were of different lengths in their UTF-8 codings (there are
3265 some cases like this - I found 11), and the matching function had to
3266 back up over a mixture of the two cases, it incorrectly assumed they
3267 were both the same length.
3268
3269 (b) When PCRE was configured to use the heap rather than the stack for
3270 recursion during matching, it was not correctly preserving the data for
3271 the other case of a UTF-8 character when checking ahead for a match
3272 while processing a minimizing repeat. If the check also involved
3273 matching a wide character, but failed, corruption could cause an
3274 erroneous result when trying to check for a repeat of the original
3275 character.
3276
3277 13. Some tidying changes to the testing mechanism:
3278
3279 (a) The RunTest script now detects the internal link size and whether there
3280 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
3281 values substituted by "configure". (The RunGrepTest script already did
3282 this for UTF-8.) The configure.ac script no longer substitutes the
3283 relevant variables.
3284
3285 (b) The debugging options /B and /D in pcretest show the compiled bytecode
3286 with length and offset values. This means that the output is different
3287 for different internal link sizes. Test 2 is skipped for link sizes
3288 other than 2 because of this, bypassing the problem. Unfortunately,
3289 there was also a test in test 3 (the locale tests) that used /B and
3290 failed for link sizes other than 2. Rather than cut the whole test out,
3291 I have added a new /Z option to pcretest that replaces the length and
3292 offset values with spaces. This is now used to make test 3 independent
3293 of link size. (Test 2 will be tidied up later.)
3294
3295 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
3296 segmentation fault instead of returning the appropriate error message.
3297
3298 15. In multiline mode when the newline sequence was set to "any", the pattern
3299 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
3300 This doesn't seem right; it now treats the CRLF combination as the line
3301 ending, and so does not match in that case. It's only a pattern such as ^$
3302 that would hit this one: something like ^ABC$ would have failed after \r
3303 and then tried again after \r\n.
3304
3305 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
3306 in an attempt to make files that differ only in their line terminators
3307 compare equal. This works on Linux.
3308
3309 17. Under certain error circumstances pcregrep might try to free random memory
3310 as it exited. This is now fixed, thanks to valgrind.
3311
3312 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
3313 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
3314 was because its rules for how to advance for /g after matching an empty
3315 string at the end of a line did not allow for this case. They now check for
3316 it specially.
3317
3318 20. pcretest is supposed to handle patterns and data of any length, by
3319 extending its buffers when necessary. It was getting this wrong when the
3320 buffer for a data line had to be extended.
3321
3322 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
3323 CRLF as a newline sequence.
3324
3325 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
3326 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
3327 I have nevertheless tidied it up.
3328
3329 23. Added some casts to kill warnings from HP-UX ia64 compiler.
3330
3331 24. Added a man page for pcre-config.
3332
3333
3334 Version 7.0 19-Dec-06
3335 ---------------------
3336
3337 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
3338 moving to gcc 4.1.1.
3339
3340 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
3341 sys/time.h, which is documented as needed for this function. It doesn't
3342 seem to matter on Linux, but it showed up on some releases of OS X.
3343
3344 3. It seems that there are systems where bytes whose values are greater than
3345 127 match isprint() in the "C" locale. The "C" locale should be the
3346 default when a C program starts up. In most systems, only ASCII printing
3347 characters match isprint(). This difference caused the output from pcretest
3348 to vary, making some of the tests fail. I have changed pcretest so that:
3349
3350 (a) When it is outputting text in the compiled version of a pattern, bytes
3351 other than 32-126 are always shown as hex escapes.
3352
3353 (b) When it is outputting text that is a matched part of a subject string,
3354 it does the same, unless a different locale has been set for the match
3355 (using the /L modifier). In this case, it uses isprint() to decide.
3356
3357 4. Fixed a major bug that caused incorrect computation of the amount of memory
3358 required for a compiled pattern when options that changed within the
3359 pattern affected the logic of the preliminary scan that determines the
3360 length. The relevant options are -x, and -i in UTF-8 mode. The result was
3361 that the computed length was too small. The symptoms of this bug were
3362 either the PCRE error "internal error: code overflow" from pcre_compile(),
3363 or a glibc crash with a message such as "pcretest: free(): invalid next
3364 size (fast)". Examples of patterns that provoked this bug (shown in
3365 pcretest format) are:
3366
3367 /(?-x: )/x
3368 /(?x)(?-x: \s*#\s*)/
3369 /((?i)[\x{c0}])/8
3370 /(?i:[\x{c0}])/8
3371
3372 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
3373 is now done differently.
3374
3375 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
3376 wrapper classes; (b) implement a new function in the C++ scanner that is
3377 more efficient than the old way of doing things because it avoids levels of
3378 recursion in the regex matching; (c) add a paragraph to the documentation
3379 for the FullMatch() function.
3380
3381 6. The escape sequence \n was being treated as whatever was defined as
3382 "newline". Not only was this contrary to the documentation, which states
3383 that \n is character 10 (hex 0A), but it also went horribly wrong when
3384 "newline" was defined as CRLF. This has been fixed.
3385
3386 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
3387 was being set to -1 for the "end of line" case (supposedly a value that no
3388 character can have). Though this value is never used (the check for end of
3389 line is "zero bytes in current character"), it caused compiler complaints.
3390 I've changed it to 0xffffffff.
3391
3392 8. In pcre_version.c, the version string was being built by a sequence of
3393 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
3394 string (as it is for production releases) called a macro with an empty
3395 argument. The C standard says the result of this is undefined. The gcc
3396 compiler treats it as an empty string (which was what was wanted) but it is
3397 reported that Visual C gives an error. The source has been hacked around to
3398 avoid this problem.
3399
3400 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
3401 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
3402 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
3403 of them did).
3404
3405 10. Originally, pcretest opened its input and output without "b"; then I was
3406 told that "b" was needed in some environments, so it was added for release
3407 5.0 to both the input and output. (It makes no difference on Unix-like
3408 systems.) Later I was told that it is wrong for the input on Windows. I've
3409 now abstracted the modes into two macros, to make it easier to fiddle with
3410 them, and removed "b" from the input mode under Windows.
3411
3412 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
3413
3414 12. Added -help and --help to pcretest as an official way of being reminded
3415 of the options.
3416
3417 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
3418 and pcrecpp.cc because they annoy compilers at high warning levels.
3419
3420 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
3421
3422 15. Fixed an occurrence of == in configure.ac that should have been = (shell
3423 scripts are not C programs :-) and which was not noticed because it works
3424 on Linux.
3425
3426 16. pcretest is supposed to handle any length of pattern and data line (as one
3427 line or as a continued sequence of lines) by extending its input buffer if
3428 necessary. This feature was broken for very long pattern lines, leading to
3429 a string of junk being passed to pcre_compile() if the pattern was longer
3430 than about 50K.
3431
3432 17. I have done a major re-factoring of the way pcre_compile() computes the
3433 amount of memory needed for a compiled pattern. Previously, there was code
3434 that made a preliminary scan of the pattern in order to do this. That was
3435 OK when PCRE was new, but as the facilities have expanded, it has become
3436 harder and harder to keep it in step with the real compile phase, and there
3437 have been a number of bugs (see for example, 4 above). I have now found a
3438 cunning way of running the real compile function in a "fake" mode that
3439 enables it to compute how much memory it would need, while actually only
3440 ever using a few hundred bytes of working memory and without too many
3441 tests of the mode. This should make future maintenance and development
3442 easier. A side effect of this work is that the limit of 200 on the nesting
3443 depth of parentheses has been removed (though this was never a serious
3444 limitation, I suspect). However, there is a downside: pcre_compile() now
3445 runs more slowly than before (30% or more, depending on the pattern). I
3446 hope this isn't a big issue. There is no effect on runtime performance.
3447
3448 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
3449 newline (only possible for the last line of a file) and it was a
3450 pattern that set a locale (followed by /Lsomething), pcretest crashed.
3451
3452 19. Added additional timing features to pcretest. (1) The -tm option now times
3453 matching only, not compiling. (2) Both -t and -tm can be followed, as a
3454 separate command line item, by a number that specifies the number of
3455 repeats to use when timing. The default is 50000; this gives better
3456 precision, but takes uncomfortably long for very large patterns.
3457
3458 20. Extended pcre_study() to be more clever in cases where a branch of a
3459 subpattern has no definite first character. For example, (a*|b*)[cd] would
3460 previously give no result from pcre_study(). Now it recognizes that the
3461 first character must be a, b, c, or d.
3462
3463 21. There was an incorrect error "recursive call could loop indefinitely" if
3464 a subpattern (or the entire pattern) that was being tested for matching an
3465 empty string contained only one non-empty item after a nested subpattern.
3466 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
3467 incorrectly, because the \d was being skipped in the check.
3468
3469 22. The pcretest program now has a new pattern option /B and a command line
3470 option -b, which is equivalent to adding /B to every pattern. This causes
3471 it to show the compiled bytecode, without the additional information that
3472 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
3473 is the same as /B/I).
3474
3475 23. A new optimization is now able automatically to treat some sequences such
3476 as a*b as a*+b. More specifically, if something simple (such as a character
3477 or a simple class like \d) has an unlimited quantifier, and is followed by
3478 something that cannot possibly match the quantified thing, the quantifier
3479 is automatically "possessified".
3480
3481 24. A recursive reference to a subpattern whose number was greater than 39
3482 went wrong under certain circumstances in UTF-8 mode. This bug could also
3483 have affected the operation of pcre_study().
3484
3485 25. Realized that a little bit of performance could be had by replacing
3486 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
3487
3488 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
3489
3490 27. Possessive quantifiers such as a++ were previously implemented by turning
3491 them into atomic groups such as ($>a+). Now they have their own opcodes,
3492 which improves performance. This includes the automatically created ones
3493 from 23 above.
3494
3495 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
3496 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
3497 the first matched character to be a colon. This applied both to named and
3498 numbered groups.
3499
3500 29. The ucpinternal.h header file was missing its idempotency #ifdef.
3501
3502 30. I was sent a "project" file called libpcre.a.dev which I understand makes
3503 building PCRE on Windows easier, so I have included it in the distribution.
3504
3505 31. There is now a check in pcretest against a ridiculously large number being
3506 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
3507 loop, the loop is abandoned.
3508
3509 32. Forward references to subpatterns in conditions such as (?(2)...) where
3510 subpattern 2 is defined later cause pcre_compile() to search forwards in
3511 the pattern for the relevant set of parentheses. This search went wrong
3512 when there were unescaped parentheses in a character class, parentheses
3513 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
3514
3515 33. "Subroutine" calls and backreferences were previously restricted to
3516 referencing subpatterns earlier in the regex. This restriction has now
3517 been removed.
3518
3519 34. Added a number of extra features that are going to be in Perl 5.10. On the
3520 whole, these are just syntactic alternatives for features that PCRE had
3521 previously implemented using the Python syntax or my own invention. The
3522 other formats are all retained for compatibility.
3523
3524 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
3525 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
3526 also .NET compatible.
3527
3528 (b) A recursion or subroutine call to a named group can now be defined as
3529 (?&name) as well as (?P>name).
3530
3531 (c) A backreference to a named group can now be defined as \k<name> or
3532 \k'name' as well as (?P=name). The new forms, as well as being in Perl
3533 5.10, are also .NET compatible.
3534
3535 (d) A conditional reference to a named group can now use the syntax
3536 (?(<name>) or (?('name') as well as (?(name).
3537
3538 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
3539 groups (named and numbered) that are never evaluated inline, but can be
3540 called as "subroutines" from elsewhere. In effect, the DEFINE condition
3541 is always false. There may be only one alternative in such a group.
3542
3543 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
3544 as the simple (?(R). The condition is true only if the most recent
3545 recursion is that of the given number or name. It does not search out
3546 through the entire recursion stack.
3547
3548 (g) The escape \gN or \g{N} has been added, where N is a positive or
3549 negative number, specifying an absolute or relative reference.
3550
3551 35. Tidied to get rid of some further signed/unsigned compiler warnings and
3552 some "unreachable code" warnings.
3553
3554 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
3555 things, this adds five new scripts.
3556
3557 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
3558 There were also incompatibilities regarding the handling of \Q..\E inside
3559 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
3560 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
3561
3562 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
3563 matches an empty string, and forcibly breaks the loop. There were bugs in
3564 this code in non-simple cases. For a pattern such as ^(a()*)* matched
3565 against aaaa the result was just "a" rather than "aaaa", for example. Two
3566 separate and independent bugs (that affected different cases) have been
3567 fixed.
3568
3569 39. Refactored the code to abolish the use of different opcodes for small
3570 capturing bracket numbers. This is a tidy that I avoided doing when I
3571 removed the limit on the number of capturing brackets for 3.5 back in 2001.
3572 The new approach is not only tidier, it makes it possible to reduce the
3573 memory needed to fix the previous bug (38).
3574
3575 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
3576 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
3577 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
3578 mode.
3579
3580 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
3581 report.
3582
3583 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
3584 copy construction and assignment in the C++ wrapper.
3585
3586 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
3587 couple of bugs that could have given wrong results in the "--newline=crlf"
3588 case.
3589
3590 44. Added a number of casts and did some reorganization of signed/unsigned int
3591 variables following suggestions from Dair Grant. Also renamed the variable
3592 "this" as "item" because it is a C++ keyword.
3593
3594 45. Arranged for dftables to add
3595
3596 #include "pcre_internal.h"
3597
3598 to pcre_chartables.c because without it, gcc 4.x may remove the array
3599 definition from the final binary if PCRE is built into a static library and
3600 dead code stripping is activated.
3601
3602 46. For an unanchored pattern, if a match attempt fails at the start of a
3603 newline sequence, and the newline setting is CRLF or ANY, and the next two
3604 characters are CRLF, advance by two characters instead of one.
3605
3606
3607 Version 6.7 04-Jul-06
3608 ---------------------
3609
3610 1. In order to handle tests when input lines are enormously long, pcretest has
3611 been re-factored so that it automatically extends its buffers when
3612 necessary. The code is crude, but this _is_ just a test program. The
3613 default size has been increased from 32K to 50K.
3614
3615 2. The code in pcre_study() was using the value of the re argument before
3616 testing it for NULL. (Of course, in any sensible call of the function, it
3617 won't be NULL.)
3618
3619 3. The memmove() emulation function in pcre_internal.h, which is used on
3620 systems that lack both memmove() and bcopy() - that is, hardly ever -
3621 was missing a "static" storage class specifier.
3622
3623 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
3624 containing an extended class (one that cannot be represented by a bitmap
3625 because it contains high-valued characters or Unicode property items, e.g.
3626 [\pZ]). Almost always one would set UTF-8 mode when processing such a
3627 pattern, but PCRE should not loop if you do not (it no longer does).
3628 [Detail: two cases were found: (a) a repeated subpattern containing an
3629 extended class; (b) a recursive reference to a subpattern that followed a
3630 previous extended class. It wasn't skipping over the extended class
3631 correctly when UTF-8 mode was not set.]
3632
3633 5. A negated single-character class was not being recognized as fixed-length
3634 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
3635 compile error "lookbehind assertion is not fixed length".
3636
3637 6. The RunPerlTest auxiliary script was showing an unexpected difference
3638 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
3639 write a Perl script that can interpret lines of an input file either as
3640 byte characters or as UTF-8, which is what "perltest" was being required to
3641 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
3642 can't do is switch easily at run time between having the "use utf8;" pragma
3643 or not. In the end, I fudged it by using the RunPerlTest script to insert
3644 "use utf8;" explicitly for the UTF-8 tests.
3645
3646 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
3647 the end of the subject string, contrary to the documentation and to what
3648 Perl does. This was true of both matching functions. Now it matches only at
3649 the start of the subject and immediately after *internal* newlines.
3650
3651 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
3652 a pointer to an int instead of a pointer to an unsigned long int. This
3653 caused problems on 64-bit systems.
3654
3655 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
3656 instance of the 'standard' template library not being so standard".
3657
3658 10. There was no check on the number of named subpatterns nor the maximum
3659 length of a subpattern name. The product of these values is used to compute
3660 the size of the memory block for a compiled pattern. By supplying a very
3661 long subpattern name and a large number of named subpatterns, the size
3662 computation could be caused to overflow. This is now prevented by limiting
3663 the length of names to 32 characters, and the number of named subpatterns
3664 to 10,000.
3665
3666 11. Subpatterns that are repeated with specific counts have to be replicated in
3667 the compiled pattern. The size of memory for this was computed from the
3668 length of the subpattern and the repeat count. The latter is limited to
3669 65535, but there was no limit on the former, meaning that integer overflow
3670 could in principle occur. The compiled length of a repeated subpattern is
3671 now limited to 30,000 bytes in order to prevent this.
3672
3673 12. Added the optional facility to have named substrings with the same name.
3674
3675 13. Added the ability to use a named substring as a condition, using the
3676 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
3677 are numbers (not recommended). Forward references are permitted.
3678
3679 14. Added forward references in named backreferences (if you see what I mean).
3680
3681 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
3682 pattern could run off the end of the subject. For example, the pattern
3683 "(?s)(.{1,5})"8 did this with the subject "ab".
3684
3685 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
3686 PCRE_CASELESS was set when matching characters that were quantified with ?
3687 or *.
3688
3689 17. A character class other than a single negated character that had a minimum
3690 but no maximum quantifier - for example [ab]{6,} - was not handled
3691 correctly by pce_dfa_exec(). It would match only one character.
3692
3693 18. A valid (though odd) pattern that looked like a POSIX character
3694 class but used an invalid character after [ (for example [[,abc,]]) caused
3695 pcre_compile() to give the error "Failed: internal error: code overflow" or
3696 in some cases to crash with a glibc free() error. This could even happen if
3697 the pattern terminated after [[ but there just happened to be a sequence of
3698 letters, a binary zero, and a closing ] in the memory that followed.
3699
3700 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
3701 over the years. Originally (before any Unicode support), just the bottom 8
3702 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
3703 output from "man perlunicode" includes this:
3704
3705 The regular expression compiler produces polymorphic opcodes. That
3706 is, the pattern adapts to the data and automatically switches to
3707 the Unicode character scheme when presented with Unicode data--or
3708 instead uses a traditional byte scheme when presented with byte
3709 data.
3710
3711 Sadly, a wide octal escape does not cause a switch, and in a string with
3712 no other multibyte characters, these octal escapes are treated as before.
3713 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
3714 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
3715 Unicode string.
3716
3717 I have not perpetrated such confusion in PCRE. Up till now, it took just
3718 the bottom 8 bits, as in old Perl. I have now made octal escapes with
3719 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
3720 translate to the appropriate multibyte character.
3721
3722 29. Applied some refactoring to reduce the number of warnings from Microsoft
3723 and Borland compilers. This has included removing the fudge introduced
3724 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
3725 a warning about an unused variable.
3726
3727 21. PCRE has not included VT (character 0x0b) in the set of whitespace
3728 characters since release 4.0, because Perl (from release 5.004) does not.
3729 [Or at least, is documented not to: some releases seem to be in conflict
3730 with the documentation.] However, when a pattern was studied with
3731 pcre_study() and all its branches started with \s, PCRE still included VT
3732 as a possible starting character. Of course, this did no harm; it just
3733 caused an unnecessary match attempt.
3734
3735 22. Removed a now-redundant internal flag bit that recorded the fact that case
3736 dependency changed within the pattern. This was once needed for "required
3737 byte" processing, but is no longer used. This recovers a now-scarce options
3738 bit. Also moved the least significant internal flag bit to the most-
3739 significant bit of the word, which was not previously used (hangover from
3740 the days when it was an int rather than a uint) to free up another bit for
3741 the future.
3742
3743 23. Added support for CRLF line endings as well as CR and LF. As well as the
3744 default being selectable at build time, it can now be changed at runtime
3745 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
3746 specify that it is scanning data with non-default line endings.
3747
3748 24. Changed the definition of CXXLINK to make it agree with the definition of
3749 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
3750
3751 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
3752 recursions. This makes a big different to stack usage for some patterns.
3753
3754 26. If a subpattern containing a named recursion or subroutine reference such
3755 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
3756 the space required for the compiled pattern went wrong and gave too small a
3757 value. Depending on the environment, this could lead to "Failed: internal
3758 error: code overflow at offset 49" or "glibc detected double free or
3759 corruption" errors.
3760
3761 27. Applied patches from Google (a) to support the new newline modes and (b) to
3762 advance over multibyte UTF-8 characters in GlobalReplace.
3763
3764 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
3765 difference for some implementation of PCRE in some Windows version.
3766
3767 29. Added some extra testing facilities to pcretest:
3768
3769 \q<number> in a data line sets the "match limit" value
3770 \Q<number> in a data line sets the "match recursion limt" value
3771 -S <number> sets the stack size, where <number> is in megabytes
3772
3773 The -S option isn't available for Windows.
3774
3775
3776 Version 6.6 06-Feb-06
3777 ---------------------
3778
3779 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
3780 in pcreposix.h. I have copied the definition from pcre.h.
3781
3782 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
3783 because pcre.h is no longer a built file.
3784
3785 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
3786 not normally included in the compiled code.
3787
3788
3789 Version 6.5 01-Feb-06
3790 ---------------------
3791
3792 1. When using the partial match feature with pcre_dfa_exec(), it was not
3793 anchoring the second and subsequent partial matches at the new starting
3794 point. This could lead to incorrect results. For example, with the pattern
3795 /1234/, partially matching against "123" and then "a4" gave a match.
3796
3797 2. Changes to pcregrep:
3798
3799 (a) All non-match returns from pcre_exec() were being treated as failures
3800 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
3801 error message is output. Some extra information is given for the
3802 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
3803 probably the only errors that are likely to be caused by users (by
3804 specifying a regex that has nested indefinite repeats, for instance).
3805 If there are more than 20 of these errors, pcregrep is abandoned.
3806
3807 (b) A binary zero was treated as data while matching, but terminated the
3808 output line if it was written out. This has been fixed: binary zeroes
3809 are now no different to any other data bytes.
3810
3811 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
3812 used to set a locale for matching. The --locale=xxxx long option has
3813 been added (no short equivalent) to specify a locale explicitly on the
3814 pcregrep command, overriding the environment variables.
3815
3816 (d) When -B was used with -n, some line numbers in the output were one less
3817 than they should have been.
3818
3819 (e) Added the -o (--only-matching) option.
3820
3821 (f) If -A or -C was used with -c (count only), some lines of context were
3822 accidentally printed for the final match.
3823
3824 (g) Added the -H (--with-filename) option.
3825
3826 (h) The combination of options -rh failed to suppress file names for files
3827 that were found from directory arguments.
3828
3829 (i) Added the -D (--devices) and -d (--directories) options.
3830
3831 (j) Added the -F (--fixed-strings) option.
3832
3833 (k) Allow "-" to be used as a file name for -f as well as for a data file.
3834
3835 (l) Added the --colo(u)r option.
3836
3837 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
3838 is not present by default.
3839
3840 3. A nasty bug was discovered in the handling of recursive patterns, that is,
3841 items such as (?R) or (?1), when the recursion could match a number of
3842 alternatives. If it matched one of the alternatives, but subsequently,
3843 outside the recursion, there was a failure, the code tried to back up into
3844 the recursion. However, because of the way PCRE is implemented, this is not
3845 possible, and the result was an incorrect result from the match.
3846
3847 In order to prevent this happening, the specification of recursion has
3848 been changed so that all such subpatterns are automatically treated as
3849 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
3850
3851 4. I had overlooked the fact that, in some locales, there are characters for
3852 which isalpha() is true but neither isupper() nor islower() are true. In
3853 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
3854 and ordfeminine) are like this. This affected the treatment of \w and \W
3855 when they appeared in character classes, but not when they appeared outside
3856 a character class. The bit map for "word" characters is now created
3857 separately from the results of isalnum() instead of just taking it from the
3858 upper, lower, and digit maps. (Plus the underscore character, of course.)
3859
3860 5. The above bug also affected the handling of POSIX character classes such as
3861 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
3862 permanent tables. Instead, the bit maps for such a class were previously
3863 created as the appropriate unions of the upper, lower, and digit bitmaps.
3864 Now they are created by subtraction from the [[:word:]] class, which has
3865 its own bitmap.
3866
3867 6. The [[:blank:]] character class matches horizontal, but not vertical space.
3868 It is created by subtracting the vertical space characters (\x09, \x0a,
3869 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
3870 subtraction was done in the overall bitmap for a character class, meaning
3871 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
3872 be recognized. This bug has been fixed.
3873
3874 7. Patches from the folks at Google:
3875
3876 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
3877 real life, but is still worth protecting against".
3878
3879 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
3880 regular expressions".
3881
3882 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
3883 have it.
3884
3885 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
3886 "configure" and the latter not, in order to fix a problem somebody had
3887 with compiling the Arg class on HP-UX.
3888
3889 (e) Improve the error-handling of the C++ wrapper a little bit.
3890
3891 (f) New tests for checking recursion limiting.
3892
3893 8. The pcre_memmove() function, which is used only if the environment does not
3894 have a standard memmove() function (and is therefore rarely compiled),
3895 contained two bugs: (a) use of int instead of size_t, and (b) it was not
3896 returning a result (though PCRE never actually uses the result).
3897
3898 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
3899 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
3900 returned instead of calling malloc() with an overflowing number that would
3901 most likely cause subsequent chaos.
3902
3903 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
3904
3905 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
3906 with this option is matched, the nmatch and pmatch options of regexec() are
3907 ignored.
3908
3909 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
3910 provided in case anyone wants to the the POSIX interface with UTF-8
3911 strings.
3912
3913 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
3914 C++ linking (needed for some HP-UX environments).
3915
3916 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
3917 (unused parameter) and in the pcre_printint() function (omitted "default"
3918 switch label when the default is to do nothing).
3919
3920 15. Added some code to make it possible, when PCRE is compiled as a C++
3921 library, to replace subject pointers for pcre_exec() with a smart pointer
3922 class, thus making it possible to process discontinuous strings.
3923
3924 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
3925 much the same function. They were added by different people who were trying
3926 to make PCRE easy to compile on non-Unix systems. It has been suggested
3927 that PCRE_EXPORT be abolished now that there is more automatic apparatus
3928 for compiling on Windows systems. I have therefore replaced it with
3929 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
3930 defaults to "extern" for C or "extern C" for C++, which works fine on
3931 Unix-like systems. It is now possible to override the value of PCRE_DATA_
3932 SCOPE with something explicit in config.h. In addition:
3933
3934 (a) pcreposix.h still had just "extern" instead of either of these macros;
3935 I have replaced it with PCRE_DATA_SCOPE.
3936
3937 (b) Functions such as _pcre_xclass(), which are internal to the library,
3938 but external in the C sense, all had PCRE_EXPORT in their definitions.
3939 This is apparently wrong for the Windows case, so I have removed it.
3940 (It makes no difference on Unix-like systems.)
3941
3942 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
3943 of recursive calls to match(). This is different to MATCH_LIMIT because
3944 that limits the total number of calls to match(), not all of which increase
3945 the depth of recursion. Limiting the recursion depth limits the amount of
3946 stack (or heap if NO_RECURSE is set) that is used. The default can be set
3947 when PCRE is compiled, and changed at run time. A patch from Google adds
3948 this functionality to the C++ interface.
3949
3950 18. Changes to the handling of Unicode character properties:
3951
3952 (a) Updated the table to Unicode 4.1.0.
3953
3954 (b) Recognize characters that are not in the table as "Cn" (undefined).
3955
3956 (c) I revised the way the table is implemented to a much improved format
3957 which includes recognition of ranges. It now supports the ranges that
3958 are defined in UnicodeData.txt, and it also amalgamates other
3959 characters into ranges. This has reduced the number of entries in the
3960 table from around 16,000 to around 3,000, thus reducing its size
3961 considerably. I realized I did not need to use a tree structure after
3962 all - a binary chop search is just as efficient. Having reduced the
3963 number of entries, I extended their size from 6 bytes to 8 bytes to
3964 allow for more data.
3965
3966 (d) Added support for Unicode script names via properties such as \p{Han}.
3967
3968 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
3969 matching that character.
3970
3971 20. When matching a repeated Unicode property with a minimum greater than zero,
3972 (for example \pL{2,}), PCRE could look past the end of the subject if it
3973 reached it while seeking the minimum number of characters. This could
3974 happen only if some of the characters were more than one byte long, because
3975 there is a check for at least the minimum number of bytes.
3976
3977 21. Refactored the implementation of \p and \P so as to be more general, to
3978 allow for more different types of property in future. This has changed the
3979 compiled form incompatibly. Anybody with saved compiled patterns that use
3980 \p or \P will have to recompile them.
3981
3982 22. Added "Any" and "L&" to the supported property types.
3983
3984 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
3985 but give a compile time error if the value is greater than 0xff.
3986
3987 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
3988 accidentally not being installed or uninstalled.
3989
3990 25. The pcre.h file was built from pcre.h.in, but the only changes that were
3991 made were to insert the current release number. This seemed silly, because
3992 it made things harder for people building PCRE on systems that don't run
3993 "configure". I have turned pcre.h into a distributed file, no longer built
3994 by "configure", with the version identification directly included. There is
3995 no longer a pcre.h.in file.
3996
3997 However, this change necessitated a change to the pcre-config script as
3998 well. It is built from pcre-config.in, and one of the substitutions was the
3999 release number. I have updated configure.ac so that ./configure now finds
4000 the release number by grepping pcre.h.
4001
4002 26. Added the ability to run the tests under valgrind.
4003
4004
4005 Version 6.4 05-Sep-05
4006 ---------------------
4007
4008 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
4009 "--" to be printed when multiple files were scanned, even when none of the
4010 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
4011 consider it to be a bug, and have restored the previous behaviour.
4012
4013 2. A couple of code tidies to get rid of compiler warnings.
4014
4015 3. The pcretest program used to cheat by referring to symbols in the library
4016 whose names begin with _pcre_. These are internal symbols that are not
4017 really supposed to be visible externally, and in some environments it is
4018 possible to suppress them. The cheating is now confined to including
4019 certain files from the library's source, which is a bit cleaner.
4020
4021 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
4022 file's purpose clearer.
4023
4024 5. Reorganized pcre_ucp_findchar().
4025
4026
4027 Version 6.3 15-Aug-05
4028 ---------------------
4029
4030 1. The file libpcre.pc.in did not have general read permission in the tarball.
4031
4032 2. There were some problems when building without C++ support:
4033
4034 (a) If C++ support was not built, "make install" and "make test" still
4035 tried to test it.
4036
4037 (b) There were problems when the value of CXX was explicitly set. Some
4038 changes have been made to try to fix these, and ...
4039
4040 (c) --disable-cpp can now be used to explicitly disable C++ support.
4041
4042 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
4043 backslash in a target when C++ was disabled. This confuses some
4044 versions of "make", apparently. Using an intermediate variable solves
4045 this. (Same for CPP_LOBJ.)
4046
4047 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
4048 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
4049 necessary on certain architectures.
4050
4051 4. Added a setting of -export-symbols-regex to the link command to remove
4052 those symbols that are exported in the C sense, but actually are local
4053 within the library, and not documented. Their names all begin with
4054 "_pcre_". This is not a perfect job, because (a) we have to except some
4055 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
4056 available (and never for static libraries). I have made a note to try to
4057 find a way round (a) in the future.
4058
4059
4060 Version 6.2 01-Aug-05
4061 ---------------------
4062
4063 1. There was no test for integer overflow of quantifier values. A construction
4064 such as {1111111111111111} would give undefined results. What is worse, if
4065 a minimum quantifier for a parenthesized subpattern overflowed and became
4066 negative, the calculation of the memory size went wrong. This could have
4067 led to memory overwriting.
4068
4069 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
4070
4071 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
4072 operating environments where this matters.
4073
4074 4. Applied Giuseppe Maxia's patch to add additional features for controlling
4075 PCRE options from within the C++ wrapper.
4076
4077 5. Named capturing subpatterns were not being correctly counted when a pattern
4078 was compiled. This caused two problems: (a) If there were more than 100
4079 such subpatterns, the calculation of the memory needed for the whole
4080 compiled pattern went wrong, leading to an overflow error. (b) Numerical
4081 back references of the form \12, where the number was greater than 9, were
4082 not recognized as back references, even though there were sufficient
4083 previous subpatterns.
4084
4085 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
4086 versions of gcc, e.g. 2.95.4.
4087
4088
4089 Version 6.1 21-Jun-05
4090 ---------------------
4091
4092 1. There was one reference to the variable "posix" in pcretest.c that was not
4093 surrounded by "#if !defined NOPOSIX".
4094
4095 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
4096 the cross-check on the old pcre_info() function, for the benefit of the
4097 cut-down version of PCRE that is currently imported into Exim.
4098
4099 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
4100 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
4101 patterns that start (?i) but I don't think that matters. The use of (?i) is
4102 just an example; this all applies to the other options as well.
4103
4104 4. Since libtool seems to echo the compile commands it is issuing, the output
4105 from "make" can be reduced a bit by putting "@" in front of each libtool
4106 compile command.
4107
4108 5. Patch from the folks at Google for configure.in to be a bit more thorough
4109 in checking for a suitable C++ installation before trying to compile the
4110 C++ stuff. This should fix a reported problem when a compiler was present,
4111 but no suitable headers.
4112
4113 6. The man pages all had just "PCRE" as their title. I have changed them to
4114 be the relevant file name. I have also arranged that these names are
4115 retained in the file doc/pcre.txt, which is a concatenation in text format
4116 of all the man pages except the little individual ones for each function.
4117
4118 7. The NON-UNIX-USE file had not been updated for the different set of source
4119 files that come with release 6. I also added a few comments about the C++
4120 wrapper.
4121
4122
4123 Version 6.0 07-Jun-05
4124 ---------------------
4125
4126 1. Some minor internal re-organization to help with my DFA experiments.
4127
4128 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
4129 didn't matter for the library itself when fully configured, but did matter
4130 when compiling without UCP support, or within Exim, where the ucp files are
4131 not imported.
4132
4133 3. Refactoring of the library code to split up the various functions into
4134 different source modules. The addition of the new DFA matching code (see
4135 below) to a single monolithic source would have made it really too
4136 unwieldy, quite apart from causing all the code to be include in a
4137 statically linked application, when only some functions are used. This is
4138 relevant even without the DFA addition now that patterns can be compiled in
4139 one application and matched in another.
4140
4141 The downside of splitting up is that there have to be some external
4142 functions and data tables that are used internally in different modules of
4143 the library but which are not part of the API. These have all had their
4144 names changed to start with "_pcre_" so that they are unlikely to clash
4145 with other external names.
4146
4147 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
4148 a different (DFA) algorithm. Although it is slower than the original
4149 function, it does have some advantages for certain types of matching
4150 problem.
4151
4152 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
4153 including restarting after a partial match.
4154
4155 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
4156 defined when compiling for Windows was sent to me. I have put it into the
4157 code, though I have no means of testing or verifying it.
4158
4159 7. Added the pcre_refcount() auxiliary function.
4160
4161 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
4162 match before or at the first newline in the subject string. In pcretest,
4163 the /f option on a pattern can be used to set this.
4164
4165 9. A repeated \w when used in UTF-8 mode with characters greater than 256
4166 would behave wrongly. This has been present in PCRE since release 4.0.
4167
4168 10. A number of changes to the pcregrep command:
4169
4170 (a) Refactored how -x works; insert ^(...)$ instead of setting
4171 PCRE_ANCHORED and checking the length, in preparation for adding
4172 something similar for -w.
4173
4174 (b) Added the -w (match as a word) option.
4175
4176 (c) Refactored the way lines are read and buffered so as to have more
4177 than one at a time available.
4178
4179 (d) Implemented a pcregrep test script.
4180
4181 (e) Added the -M (multiline match) option. This allows patterns to match
4182 over several lines of the subject. The buffering ensures that at least
4183 8K, or the rest of the document (whichever is the shorter) is available
4184 for matching (and similarly the previous 8K for lookbehind assertions).
4185
4186 (f) Changed the --help output so that it now says
4187
4188 -w, --word-regex(p)
4189
4190 instead of two lines, one with "regex" and the other with "regexp"
4191 because that confused at least one person since the short forms are the
4192 same. (This required a bit of code, as the output is generated
4193 automatically from a table. It wasn't just a text change.)
4194
4195 (g) -- can be used to terminate pcregrep options if the next thing isn't an
4196 option but starts with a hyphen. Could be a pattern or a path name
4197 starting with a hyphen, for instance.
4198
4199 (h) "-" can be given as a file name to represent stdin.
4200
4201 (i) When file names are being printed, "(standard input)" is used for
4202 the standard input, for compatibility with GNU grep. Previously
4203 "<stdin>" was used.
4204
4205 (j) The option --label=xxx can be used to supply a name to be used for
4206 stdin when file names are being printed. There is no short form.
4207
4208 (k) Re-factored the options decoding logic because we are going to add
4209 two more options that take data. Such options can now be given in four
4210 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
4211
4212 (l) Added the -A, -B, and -C options for requesting that lines of context
4213 around matches be printed.
4214
4215 (m) Added the -L option to print the names of files that do not contain
4216 any matching lines, that is, the complement of -l.
4217
4218 (n) The return code is 2 if any file cannot be opened, but pcregrep does
4219 continue to scan other files.
4220
4221 (o) The -s option was incorrectly implemented. For compatibility with other
4222 greps, it now suppresses the error message for a non-existent or non-
4223 accessible file (but not the return code). There is a new option called
4224 -q that suppresses the output of matching lines, which was what -s was
4225 previously doing.
4226
4227 (p) Added --include and --exclude options to specify files for inclusion
4228 and exclusion when recursing.
4229
4230 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
4231 Hopefully, it now does.
4232
4233 12. Missing cast in pcre_study().
4234
4235 13. Added an "uninstall" target to the makefile.
4236
4237 14. Replaced "extern" in the function prototypes in Makefile.in with
4238 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
4239 world, but is set differently for Windows.
4240
4241 15. Added a second compiling function called pcre_compile2(). The only
4242 difference is that it has an extra argument, which is a pointer to an
4243 integer error code. When there is a compile-time failure, this is set
4244 non-zero, in addition to the error test pointer being set to point to an
4245 error message. The new argument may be NULL if no error number is required
4246 (but then you may as well call pcre_compile(), which is now just a
4247 wrapper). This facility is provided because some applications need a
4248 numeric error indication, but it has also enabled me to tidy up the way
4249 compile-time errors are handled in the POSIX wrapper.
4250
4251 16. Added VPATH=.libs to the makefile; this should help when building with one
4252 prefix path and installing with another. (Or so I'm told by someone who
4253 knows more about this stuff than I do.)
4254
4255 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
4256 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
4257 match everything, including newlines. This is not POSIX-compatible, but
4258 somebody wanted the feature. From pcretest it can be activated by using
4259 both the P and the s flags.
4260
4261 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
4262
4263 19. libpcre.pc was being incorrectly installed as executable.
4264
4265 20. A couple of places in pcretest check for end-of-line by looking for '\n';
4266 it now also looks for '\r' so that it will work unmodified on Windows.
4267
4268 21. Added Google's contributed C++ wrapper to the distribution.
4269
4270 22. Added some untidy missing memory free() calls in pcretest, to keep
4271 Electric Fence happy when testing.
4272
4273
4274
4275 Version 5.0 13-Sep-04
4276 ---------------------
4277
4278 1. Internal change: literal characters are no longer packed up into items
4279 containing multiple characters in a single byte-string. Each character
4280 is now matched using a separate opcode. However, there may be more than one
4281 byte in the character in UTF-8 mode.
4282
4283 2. The pcre_callout_block structure has two new fields: pattern_position and
4284 next_item_length. These contain the offset in the pattern to the next match
4285 item, and its length, respectively.
4286
4287 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
4288 insertion of callouts before each pattern item. Added the /C option to
4289 pcretest to make use of this.
4290
4291 4. On the advice of a Windows user, the lines
4292
4293 #if defined(_WIN32) || defined(WIN32)
4294 _setmode( _fileno( stdout ), 0x8000 );
4295 #endif /* defined(_WIN32) || defined(WIN32) */
4296
4297 have been added to the source of pcretest. This apparently does useful
4298 magic in relation to line terminators.
4299
4300 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
4301 for the benefit of those environments where the "b" makes a difference.
4302
4303 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
4304 to know about it. I have put a hack into configure.in that adds in code
4305 to set GCC=yes if CC=icc. This seems to end up at a point in the
4306 generated configure script that is early enough to affect the setting of
4307 compiler options, which is what is needed, but I have no means of testing
4308 whether it really works. (The user who reported this had patched the
4309 generated configure script, which of course I cannot do.)
4310
4311 LATER: After change 22 below (new libtool files), the configure script
4312 seems to know about icc (and also ecc). Therefore, I have commented out
4313 this hack in configure.in.
4314
4315 7. Added support for pkg-config (2 patches were sent in).
4316
4317 8. Negated POSIX character classes that used a combination of internal tables
4318 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
4319 [[:^ascii]]. Typically, they would match almost any characters. The other
4320 POSIX classes were not broken in this way.
4321
4322 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
4323 to find the match, as PCRE was deluded into thinking that the match had to
4324 start at the start point or following a newline. The same bug applied to
4325 patterns with negative forward assertions or any backward assertions
4326 preceding ".*" at the start, unless the pattern required a fixed first
4327 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
4328
4329 10. In UTF-8 mode, when moving forwards in the subject after a failed match
4330 starting at the last subject character, bytes beyond the end of the subject
4331 string were read.
4332
4333 11. Renamed the variable "class" as "classbits" to make life easier for C++
4334 users. (Previously there was a macro definition, but it apparently wasn't
4335 enough.)
4336
4337 12. Added the new field "tables" to the extra data so that tables can be passed
4338 in at exec time, or the internal tables can be re-selected. This allows
4339 a compiled regex to be saved and re-used at a later time by a different
4340 program that might have everything at different addresses.
4341
4342 13. Modified the pcre-config script so that, when run on Solaris, it shows a
4343 -R library as well as a -L library.
4344
4345 14. The debugging options of pcretest (-d on the command line or D on a
4346 pattern) showed incorrect output for anything following an extended class
4347 that contained multibyte characters and which was followed by a quantifier.
4348
4349 15. Added optional support for general category Unicode character properties
4350 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
4351 support. It adds about 90K to the size of the library. The meanings of the
4352 inbuilt class escapes such as \d and \s have NOT been changed.
4353
4354 16. Updated pcredemo.c to include calls to free() to release the memory for the
4355 compiled pattern.
4356
4357 17. The generated file chartables.c was being created in the source directory
4358 instead of in the building directory. This caused the build to fail if the
4359 source directory was different from the building directory, and was
4360 read-only.
4361
4362 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
4363 file. No doubt somebody will tell me if they don't make sense... Also added
4364 Dan Mooney's comments about building on OpenVMS.
4365
4366 19. Added support for partial matching via the PCRE_PARTIAL option for
4367 pcre_exec() and the \P data escape in pcretest.
4368
4369 20. Extended pcretest with 3 new pattern features:
4370
4371 (i) A pattern option of the form ">rest-of-line" causes pcretest to
4372 write the compiled pattern to the file whose name is "rest-of-line".
4373 This is a straight binary dump of the data, with the saved pointer to
4374 the character tables forced to be NULL. The study data, if any, is
4375 written too. After writing, pcretest reads a new pattern.
4376
4377 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
4378 compiled pattern from the given file. There must not be any
4379 occurrences of "<" in the file name (pretty unlikely); if there are,
4380 pcretest will instead treat the initial "<" as a pattern delimiter.
4381 After reading in the pattern, pcretest goes on to read data lines as
4382 usual.
4383
4384 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
4385 and 16-bit fields in a compiled pattern, to simulate a pattern that
4386 was compiled on a host of opposite endianness.
4387
4388 21. The pcre-exec() function can now cope with patterns that were compiled on
4389 hosts of opposite endianness, with this restriction:
4390
4391 As for any compiled expression that is saved and used later, the tables
4392 pointer field cannot be preserved; the extra_data field in the arguments
4393 to pcre_exec() should be used to pass in a tables address if a value
4394 other than the default internal tables were used at compile time.
4395
4396 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
4397 now diagnosed as an error. Previously, most of the time, a negative number
4398 would have been treated as zero, but if in addition "ovector" was passed as
4399 NULL, a crash could occur.
4400
4401 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
4402 new versions from the libtool 1.5 distribution (the last one is a copy of
4403 a file called libtool.m4). This seems to have fixed the need to patch
4404 "configure" to support Darwin 1.3 (which I used to do). However, I still
4405 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
4406 workstation).
4407
4408 24. Changed the PCRE licence to be the more standard "BSD" licence.
4409
4410
4411 Version 4.5 01-Dec-03
4412 ---------------------
4413
4414 1. There has been some re-arrangement of the code for the match() function so
4415 that it can be compiled in a version that does not call itself recursively.
4416 Instead, it keeps those local variables that need separate instances for
4417 each "recursion" in a frame on the heap, and gets/frees frames whenever it
4418 needs to "recurse". Keeping track of where control must go is done by means
4419 of setjmp/longjmp. The whole thing is implemented by a set of macros that
4420 hide most of the details from the main code, and operates only if
4421 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
4422 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
4423 operating.
4424
4425 To make it easier for callers to provide specially tailored get/free
4426 functions for this usage, two new functions, pcre_stack_malloc, and
4427 pcre_stack_free, are used. They are always called in strict stacking order,
4428 and the size of block requested is always the same.
4429
4430 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
4431 PCRE has been compiled to use the stack or the heap for recursion. The
4432 -C option of pcretest uses this to show which version is compiled.
4433
4434 A new data escape \S, is added to pcretest; it causes the amounts of store
4435 obtained and freed by both kinds of malloc/free at match time to be added
4436 to the output.
4437
4438 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
4439 what's available on my current Linux desktop machine.
4440
4441 3. When matching a UTF-8 string, the test for a valid string at the start has
4442 been extended. If start_offset is not zero, PCRE now checks that it points
4443 to a byte that is the start of a UTF-8 character. If not, it returns
4444 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
4445 this is necessary because there may be backward assertions in the pattern.
4446 When matching the same subject several times, it may save resources to use
4447 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
4448
4449 4. The code for checking the validity of UTF-8 strings has been tightened so
4450 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
4451 containing "overlong sequences".
4452
4453 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
4454 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
4455 should have been "&", but it just so happened that all the cases this let
4456 through by mistake were picked up later in the function.
4457
4458 6. I had used a variable called "isblank" - this is a C99 function, causing
4459 some compilers to warn. To avoid this, I renamed it (as "blankclass").
4460
4461 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
4462 prompting; (b) run "./pcretest /dev/null" at the start of the test script
4463 so the version is shown; (c) stop "make test" echoing "./RunTest".
4464
4465 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
4466
4467 9. The prototype for memmove() for systems that don't have it was using
4468 size_t, but the inclusion of the header that defines size_t was later. I've
4469 moved the #includes for the C headers earlier to avoid this.
4470
4471 10. Added some adjustments to the code to make it easier to compiler on certain
4472 special systems:
4473
4474 (a) Some "const" qualifiers were missing.
4475 (b) Added the macro EXPORT before all exported functions; by default this
4476 is defined to be empty.
4477 (c) Changed the dftables auxiliary program (that builds chartables.c) so
4478 that it reads its output file name as an argument instead of writing
4479 to the standard output and assuming this can be redirected.
4480
4481 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
4482 class containing characters with values greater than 255, PCRE compilation
4483 went into a loop.
4484
4485 12. A recursive reference to a subpattern that was within another subpattern
4486 that had a minimum quantifier of zero caused PCRE to crash. For example,
4487 (x(y(?2))z)? provoked this bug with a subject that got as far as the
4488 recursion. If the recursively-called subpattern itself had a zero repeat,
4489 that was OK.
4490
4491 13. In pcretest, the buffer for reading a data line was set at 30K, but the
4492 buffer into which it was copied (for escape processing) was still set at
4493 1024, so long lines caused crashes.
4494
4495 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
4496 "internal error: code overflow...". This applied to any character class
4497 that was followed by a possessive quantifier.
4498
4499 15. Modified the Makefile to add libpcre.la as a prerequisite for
4500 libpcreposix.la because I was told this is needed for a parallel build to
4501 work.
4502
4503 16. If a pattern that contained .* following optional items at the start was
4504 studied, the wrong optimizing data was generated, leading to matching
4505 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
4506 matching string must start with a or b or c. The correct conclusion for
4507 this pattern is that a match can start with any character.
4508
4509
4510 Version 4.4 13-Aug-03
4511 ---------------------
4512
4513 1. In UTF-8 mode, a character class containing characters with values between
4514 127 and 255 was not handled correctly if the compiled pattern was studied.
4515 In fixing this, I have also improved the studying algorithm for such
4516 classes (slightly).
4517
4518 2. Three internal functions had redundant arguments passed to them. Removal
4519 might give a very teeny performance improvement.
4520
4521 3. Documentation bug: the value of the capture_top field in a callout is *one
4522 more than* the number of the hightest numbered captured substring.
4523
4524 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
4525 in incorrectly linking with a previously installed version. They now link
4526 explicitly with libpcre.la.
4527
4528 5. configure.in no longer needs to recognize Cygwin specially.
4529
4530 6. A problem in pcre.in for Windows platforms is fixed.
4531
4532 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
4533 pcretest, it used to include the size of the study block as part of its
4534 output. Unfortunately, the structure contains a field that has a different
4535 size on different hardware architectures. This meant that the tests that
4536 showed this size failed. As the block is currently always of a fixed size,
4537 this information isn't actually particularly useful in pcretest output, so
4538 I have just removed it.
4539
4540 8. Three pre-processor statements accidentally did not start in column 1.
4541 Sadly, there are *still* compilers around that complain, even though
4542 standard C has not required this for well over a decade. Sigh.
4543
4544 9. In pcretest, the code for checking callouts passed small integers in the
4545 callout_data field, which is a void * field. However, some picky compilers
4546 complained about the casts involved for this on 64-bit systems. Now
4547 pcretest passes the address of the small integer instead, which should get
4548 rid of the warnings.
4549
4550 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
4551 both compile and run time, and gives an error if an invalid UTF-8 sequence
4552 is found. There is a option for disabling this check in cases where the
4553 string is known to be correct and/or the maximum performance is wanted.
4554
4555 11. In response to a bug report, I changed one line in Makefile.in from
4556
4557 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
4558 to
4559 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
4560
4561 to look similar to other lines, but I have no way of telling whether this
4562 is the right thing to do, as I do not use Windows. No doubt I'll get told
4563 if it's wrong...
4564
4565
4566 Version 4.3 21-May-03
4567 ---------------------
4568
4569 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
4570 Makefile.
4571
4572 2. Some refactoring to improve the quality of the code:
4573
4574 (i) The utf8_table... variables are now declared "const".
4575
4576 (ii) The code for \cx, which used the "case flipping" table to upper case
4577 lower case letters, now just substracts 32. This is ASCII-specific,
4578 but the whole concept of \cx is ASCII-specific, so it seems
4579 reasonable.
4580
4581 (iii) PCRE was using its character types table to recognize decimal and
4582 hexadecimal digits in the pattern. This is silly, because it handles
4583 only 0-9, a-f, and A-F, but the character types table is locale-
4584 specific, which means strange things might happen. A private
4585 table is now used for this - though it costs 256 bytes, a table is
4586 much faster than multiple explicit tests. Of course, the standard
4587 character types table is still used for matching digits in subject
4588 strings against \d.
4589
4590 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
4591 ending in _t are). So I've renamed it as ESC_tee.
4592
4593 3. The first argument for regexec() in the POSIX wrapper should have been
4594 defined as "const".
4595
4596 4. Changed pcretest to use malloc() for its buffers so that they can be
4597 Electric Fenced for debugging.
4598
4599 5. There were several places in the code where, in UTF-8 mode, PCRE would try
4600 to read one or more bytes before the start of the subject string. Often this
4601 had no effect on PCRE's behaviour, but in some circumstances it could
4602 provoke a segmentation fault.
4603
4604 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
4605 to try to read one or more bytes before the start of the subject string.
4606
4607 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
4608 UTF-8 support could misbehave in various ways if the subject string
4609 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
4610 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
4611 back over UTF-8 characters.)
4612
4613
4614 Version 4.2 14-Apr-03
4615 ---------------------
4616
4617 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
4618
4619 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
4620 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
4621 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
4622 [WIN_PREFIX]: new variable, "cyg" for Cygwin
4623 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
4624 and BUILD_EXEEXT
4625 Note: automatic setting of the BUILD variables is not yet working
4626 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
4627 compile-time but not at link-time
4628 [LINK]: use for linking executables only
4629 make different versions for Windows and non-Windows
4630 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
4631 libraries
4632 [LINK_FOR_BUILD]: new variable
4633 [OBJEXT]: use throughout
4634 [EXEEXT]: use throughout
4635 <winshared>: new target
4636 <wininstall>: new target
4637 <dftables.o>: use native compiler
4638 <dftables>: use native linker
4639 <install>: handle Windows platform correctly
4640 <clean>: ditto
4641 <check>: ditto
4642 copy DLL to top builddir before testing
4643
4644 As part of these changes, -no-undefined was removed again. This was reported
4645 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
4646 in any case.
4647
4648 3. Some tidies to get rid of compiler warnings:
4649
4650 . In the match_data structure, match_limit was an unsigned long int, whereas
4651 match_call_count was an int. I've made them both unsigned long ints.
4652
4653 . In pcretest the fact that a const uschar * doesn't automatically cast to
4654 a void * provoked a warning.
4655
4656 . Turning on some more compiler warnings threw up some "shadow" variables
4657 and a few more missing casts.
4658
4659 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
4660 option, a class that contained a single character with a value between 128
4661 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
4662
4663 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
4664 option, a class that contained several characters, but with at least one
4665 whose value was between 128 and 255 caused PCRE to crash.
4666
4667
4668 Version 4.1 12-Mar-03
4669 ---------------------
4670
4671 1. Compiling with gcc -pedantic found a couple of places where casts were
4672 needed, and a string in dftables.c that was longer than standard compilers are
4673 required to support.
4674
4675 2. Compiling with Sun's compiler found a few more places where the code could
4676 be tidied up in order to avoid warnings.
4677
4678 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
4679 first of these names is deprecated in the latest Autoconf in favour of the name
4680 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
4681 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
4682 analogy I have changed it to CFLAGS_FOR_BUILD.
4683
4684 4. Added -no-undefined to the linking command in the Makefile, because this is
4685 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
4686 linking step for the pcreposix library.
4687
4688 5. PCRE was failing to diagnose the case of two named groups with the same
4689 name.
4690
4691 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
4692 literal character that is needed in the subject for a match, and scans along to
4693 ensure that it is present before embarking on the full matching process. This
4694 saves time in cases of nested unlimited repeats that are never going to match.
4695 Problem: the scan can take a lot of time if the subject is very long (e.g.
4696 megabytes), thus penalizing straightforward matches. It is now done only if the
4697 amount of subject to be scanned is less than 1000 bytes.
4698
4699 7. A lesser problem with the same optimization is that it was recording the
4700 first character of an anchored pattern as "needed", thus provoking a search
4701 right along the subject, even when the first match of the pattern was going to
4702 fail. The "needed" character is now not set for anchored patterns, unless it
4703 follows something in the pattern that is of non-fixed length. Thus, it still
4704 fulfils its original purpose of finding quick non-matches in cases of nested
4705 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
4706
4707
4708 Version 4.0 17-Feb-03
4709 ---------------------
4710
4711 1. If a comment in an extended regex that started immediately after a meta-item
4712 extended to the end of string, PCRE compiled incorrect data. This could lead to
4713 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
4714
4715 2. Moved to autoconf 2.53 and libtool 1.4.2.
4716
4717 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
4718 the special perltest8 script is no longer needed - all the tests can be run
4719 from a single perltest script.
4720
4721 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
4722 by \s. It has now been removed in PCRE. This means it isn't recognized as
4723 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
4724 class [:space:] *does* include VT, thereby creating a mess.
4725
4726 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
4727 space and tab.
4728
4729 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
4730 its new features into the main test script, reducing the number of scripts.
4731
4732 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
4733 were backward compatible, and made the (?i) apply to the whole pattern, as if
4734 /i were given. Now it behaves more logically, and applies the option setting
4735 only to what follows. PCRE has been changed to follow suit. However, if it
4736 finds options settings right at the start of the pattern, it extracts them into
4737 the global options, as before. Thus, they show up in the info data.
4738
4739 8. Added support for the \Q...\E escape sequence. Characters in between are
4740 treated as literals. This is slightly different from Perl in that $ and @ are
4741 also handled as literals inside the quotes. In Perl, they will cause variable
4742 interpolation. Note the following examples:
4743
4744 Pattern PCRE matches Perl matches
4745
4746 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
4747 \Qabc\$xyz\E abc\$xyz abc\$xyz
4748 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
4749
4750 For compatibility with Perl, \Q...\E sequences are recognized inside character
4751 classes as well as outside them.
4752
4753 9. Re-organized 3 code statements in pcretest to avoid "overflow in
4754 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
4755 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
4756 signed/unsigned warnings.
4757
4758 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
4759 option for pcretest, so I've replaced it by a simple function that does just
4760 that job.
4761
4762 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
4763 "pcregrep -".
4764
4765 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
4766 Java package. This provides some syntactic sugar for simple cases of what my
4767 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
4768 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
4769 item, you can use this simplified notation. Note that only makes sense with
4770 greedy quantifiers. Consequently, the use of the possessive quantifier forces
4771 greediness, whatever the setting of the PCRE_UNGREEDY option.
4772
4773 13. A change of greediness default within a pattern was not taking effect at
4774 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
4775 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
4776 was abstracted outside.
4777
4778 14. PCRE now supports the \G assertion. It is true when the current matching
4779 position is at the start point of the match. This differs from \A when the
4780 starting offset is non-zero. Used with the /g option of pcretest (or similar
4781 code), it works in the same way as it does for Perl's /g option. If all
4782 alternatives of a regex begin with \G, the expression is anchored to the start
4783 match position, and the "anchored" flag is set in the compiled expression.
4784
4785 15. Some bugs concerning the handling of certain option changes within patterns
4786 have been fixed. These applied to options other than (?ims). For example,
4787 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
4788 been the other way round. Some of this was related to change 7 above.
4789
4790 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
4791 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
4792 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
4793 POSIX classes only within a class (e.g. /[[:alpha:]]/).
4794
4795 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
4796 mode. Unlike ".", it always matches newline, whatever the setting of
4797 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
4798 assertions. Perl allows it, but it doesn't (in general) work because it can't
4799 calculate the length of the lookbehind. At least, that's the case for Perl
4800 5.8.0 - I've been told they are going to document that it doesn't work in
4801 future.
4802
4803 18. Added an error diagnosis for escapes that PCRE does not support: these are
4804 \L, \l, \N, \P, \p, \U, \u, and \X.
4805
4806 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
4807 reading past the end of the pattern in cases such as /[abcd/.
4808
4809 20. PCRE was getting more memory than necessary for patterns with classes that
4810 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
4811
4812 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
4813 compiling PCRE for use with Virtual Pascal.
4814
4815 22. Small fix to the Makefile to make it work properly if the build is done
4816 outside the source tree.
4817
4818 23. Added a new extension: a condition to go with recursion. If a conditional
4819 subpattern starts with (?(R) the "true" branch is used if recursion has
4820 happened, whereas the "false" branch is used only at the top level.
4821
4822 24. When there was a very long string of literal characters (over 255 bytes
4823 without UTF support, over 250 bytes with UTF support), the computation of how
4824 much memory was required could be incorrect, leading to segfaults or other
4825 strange effects.
4826
4827 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
4828 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
4829 there was a subsequent back reference to those brackets. This meant that, for
4830 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
4831 possible to check for precisely this case. All we can do is abandon the
4832 optimization if .* occurs inside capturing brackets when there are any back
4833 references whatsoever. (See below for a better fix that came later.)
4834
4835 26. The handling of the optimization for finding the first character of a
4836 non-anchored pattern, and for finding a character that is required later in the
4837 match were failing in some cases. This didn't break the matching; it just
4838 failed to optimize when it could. The way this is done has been re-implemented.
4839
4840 27. Fixed typo in error message for invalid (?R item (it said "(?p").
4841
4842 28. Added a new feature that provides some of the functionality that Perl
4843 provides with (?{...}). The facility is termed a "callout". The way it is done
4844 in PCRE is for the caller to provide an optional function, by setting
4845 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
4846 global variable. By default it is unset, which disables all calling out. To get
4847 the function called, the regex must include (?C) at appropriate points. This
4848 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
4849 This provides a means of identifying different callout points. When PCRE
4850 reaches such a point in the regex, if pcre_callout has been set, the external
4851 function is called. It is provided with data in a structure called
4852 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
4853 matching continues; if it returns a non-zero value, the match at the current
4854 point fails. However, backtracking will occur if possible. [This was changed
4855 later and other features added - see item 49 below.]
4856
4857 29. pcretest is upgraded to test the callout functionality. It provides a
4858 callout function that displays information. By default, it shows the start of
4859 the match and the current position in the text. There are some new data escapes
4860 to vary what happens:
4861
4862 \C+ in addition, show current contents of captured substrings
4863 \C- do not supply a callout function
4864 \C!n return 1 when callout number n is reached
4865 \C!n!m return 1 when callout number n is reached for the mth time
4866
4867 30. If pcregrep was called with the -l option and just a single file name, it
4868 output "<stdin>" if a match was found, instead of the file name.
4869
4870 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
4871 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
4872 pcre_exec(). This saves a malloc/free per call. The default value of
4873 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
4874 when configuring.
4875
4876 32. The default maximum size of a compiled pattern is 64K. There have been a
4877 few cases of people hitting this limit. The code now uses macros to handle the
4878 storing of links as offsets within the compiled pattern. It defaults to 2-byte
4879 links, but this can be changed to 3 or 4 bytes by --with-link-size when
4880 configuring. Tests 2 and 5 work only with 2-byte links because they output
4881 debugging information about compiled patterns.
4882
4883 33. Internal code re-arrangements:
4884
4885 (a) Moved the debugging function for printing out a compiled regex into
4886 its own source file (printint.c) and used #include to pull it into
4887 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
4888 separate copies.
4889
4890 (b) Defined the list of op-code names for debugging as a macro in
4891 internal.h so that it is next to the definition of the opcodes.
4892
4893 (c) Defined a table of op-code lengths for simpler skipping along compiled
4894 code. This is again a macro in internal.h so that it is next to the
4895 definition of the opcodes.
4896
4897 34. Added support for recursive calls to individual subpatterns, along the
4898 lines of Robin Houston's patch (but implemented somewhat differently).
4899
4900 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
4901 allow it to read and process whole directories in Win32. This code was
4902 contributed by Lionel Fourquaux; it has not been tested by me.
4903
4904 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
4905 used to name a group. Names consist of alphanumerics and underscores, and must
4906 be unique. Back references use the syntax (?P=name) and recursive calls use
4907 (?P>name) which is a PCRE extension to the Python extension. Groups still have
4908 numbers. The function pcre_fullinfo() can be used after compilation to extract
4909 a name/number map. There are three relevant calls:
4910
4911 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
4912 PCRE_INFO_NAMECOUNT yields the number of entries
4913 PCRE_INFO_NAMETABLE yields a pointer to the map.
4914
4915 The map is a vector of fixed-size entries. The size of each entry depends on
4916 the length of the longest name used. The first two bytes of each entry are the
4917 group number, most significant byte first. There follows the corresponding
4918 name, zero terminated. The names are in alphabetical order.
4919
4920 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
4921 case instead of 255. Making it the same both with and without UTF-8 support
4922 means that the same test output works with both.
4923
4924 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
4925 calling malloc() with a zero argument.
4926
4927 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
4928 optimization. I've improved things by keeping a bitmap of backreferences with
4929 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
4930 fact referenced, the optimization can be applied. It is unlikely that a
4931 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
4932 the match to follow \n) will appear inside brackets with a number greater than
4933 31, but if it does, any back reference > 31 suppresses the optimization.
4934
4935 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
4936 of disabling numbered capturing parentheses. Any opening parenthesis that is
4937 not followed by ? behaves as if it were followed by ?: but named parentheses
4938 can still be used for capturing (and they will acquire numbers in the usual
4939 way).
4940
4941 41. Redesigned the return codes from the match() function into yes/no/error so
4942 that errors can be passed back from deep inside the nested calls. A malloc
4943 failure while inside a recursive subpattern call now causes the
4944 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
4945
4946 42. It is now possible to set a limit on the number of times the match()
4947 function is called in a call to pcre_exec(). This facility makes it possible to
4948 limit the amount of recursion and backtracking, though not in a directly
4949 obvious way, because the match() function is used in a number of different
4950 circumstances. The count starts from zero for each position in the subject
4951 string (for non-anchored patterns). The default limit is, for compatibility, a
4952 large number, namely 10 000 000. You can change this in two ways:
4953
4954 (a) When configuring PCRE before making, you can use --with-match-limit=n
4955 to set a default value for the compiled library.
4956
4957 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
4958 a different value is set. See 45 below.
4959
4960 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
4961
4962 43. Added a new function pcre_config(int, void *) to enable run-time extraction
4963 of things that can be changed at compile time. The first argument specifies
4964 what is wanted and the second points to where the information is to be placed.
4965 The current list of available information is:
4966
4967 PCRE_CONFIG_UTF8
4968
4969 The output is an integer that is set to one if UTF-8 support is available;
4970 otherwise it is set to zero.
4971
4972 PCRE_CONFIG_NEWLINE
4973
4974 The output is an integer that it set to the value of the code that is used for
4975 newline. It is either LF (10) or CR (13).
4976
4977 PCRE_CONFIG_LINK_SIZE
4978
4979 The output is an integer that contains the number of bytes used for internal
4980 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
4981
4982 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
4983
4984 The output is an integer that contains the threshold above which the POSIX
4985 interface uses malloc() for output vectors. See item 31 above.
4986
4987 PCRE_CONFIG_MATCH_LIMIT
4988
4989 The output is an unsigned integer that contains the default limit of the number
4990 of match() calls in a pcre_exec() execution. See 42 above.
4991
4992 44. pcretest has been upgraded by the addition of the -C option. This causes it
4993 to extract all the available output from the new pcre_config() function, and to
4994 output it. The program then exits immediately.
4995
4996 45. A need has arisen to pass over additional data with calls to pcre_exec() in
4997 order to support additional features. One way would have been to define
4998 pcre_exec2() (for example) with extra arguments, but this would not have been
4999 extensible, and would also have required all calls to the original function to
5000 be mapped to the new one. Instead, I have chosen to extend the mechanism that
5001 is used for passing in "extra" data from pcre_study().
5002
5003 The pcre_extra structure is now exposed and defined in pcre.h. It currently
5004 contains the following fields:
5005
5006 flags a bitmap indicating which of the following fields are set
5007 study_data opaque data from pcre_study()
5008 match_limit a way of specifying a limit on match() calls for a specific
5009 call to pcre_exec()
5010 callout_data data for callouts (see 49 below)
5011
5012 The flag bits are also defined in pcre.h, and are
5013
5014 PCRE_EXTRA_STUDY_DATA
5015 PCRE_EXTRA_MATCH_LIMIT
5016 PCRE_EXTRA_CALLOUT_DATA
5017
5018 The pcre_study() function now returns one of these new pcre_extra blocks, with
5019 the actual study data pointed to by the study_data field, and the
5020 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
5021 before. That is, this change is entirely upwards-compatible and requires no
5022 change to existing code.
5023
5024 If you want to pass in additional data to pcre_exec(), you can either place it
5025 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
5026 block.
5027
5028 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
5029 data string contains the escape sequence \M, pcretest calls pcre_exec() several
5030 times with different match limits, until it finds the minimum value needed for
5031 pcre_exec() to complete. The value is then output. This can be instructive; for
5032 most simple matches the number is quite small, but for pathological cases it
5033 gets very large very quickly.
5034
5035 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
5036 returns the size of the data block pointed to by the study_data field in a
5037 pcre_extra block, that is, the value that was passed as the argument to
5038 pcre_malloc() when PCRE was getting memory in which to place the information
5039 created by pcre_study(). The fourth argument should point to a size_t variable.
5040 pcretest has been extended so that this information is shown after a successful
5041 pcre_study() call when information about the compiled regex is being displayed.
5042
5043 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
5044 because what follows is always an absolute path. (Later: it turns out that this
5045 is more than cosmetic for MinGW, because it doesn't like empty path
5046 components.)
5047
5048 49. Some changes have been made to the callout feature (see 28 above):
5049
5050 (i) A callout function now has three choices for what it returns:
5051
5052 0 => success, carry on matching
5053 > 0 => failure at this point, but backtrack if possible
5054 < 0 => serious error, return this value from pcre_exec()
5055
5056 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
5057 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
5058 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
5059 use by callout functions. It will never be used by PCRE itself.
5060
5061 (ii) The pcre_extra structure (see 45 above) has a void * field called
5062 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
5063 pcre_callout_block structure has a field of the same name. The contents of
5064 the field passed in the pcre_extra structure are passed to the callout
5065 function in the corresponding field in the callout block. This makes it
5066 easier to use the same callout-containing regex from multiple threads. For
5067 testing, the pcretest program has a new data escape
5068
5069 \C*n pass the number n (may be negative) as callout_data
5070
5071 If the callout function in pcretest receives a non-zero value as
5072 callout_data, it returns that value.
5073
5074 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
5075 there were some redundant $(CFLAGS) in commands that are now specified as
5076 $(LINK), which already includes $(CFLAGS).
5077
5078 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
5079 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
5080 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
5081 one-byte characters throughout. Note that case-insensitive matching applies
5082 only to characters whose values are less than 256. PCRE doesn't support the
5083 notion of cases for higher-valued characters.
5084
5085 (i) A character class whose characters are all within 0-255 is handled as
5086 a bit map, and the map is inverted for negative classes. Previously, a
5087 character > 255 always failed to match such a class; however it should
5088 match if the class was a negative one (e.g. [^ab]). This has been fixed.
5089
5090 (ii) A negated character class with a single character < 255 is coded as
5091 "not this character" (OP_NOT). This wasn't working properly when the test
5092 character was multibyte, either singly or repeated.
5093
5094 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
5095 mode, for example: \x{100}{2,3}.
5096
5097 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
5098 singly or repeated) now correctly test multibyte characters. However,
5099 PCRE doesn't recognize any characters with values greater than 255 as
5100 digits, spaces, or word characters. Such characters always match \D, \S,
5101 and \W, and never match \d, \s, or \w.
5102
5103 (v) Classes may now contain characters and character ranges with values
5104 greater than 255. For example: [ab\x{100}-\x{400}].
5105
5106 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
5107 PCRE in UTF-8 mode.
5108
5109 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
5110 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
5111 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
5112 value.)
5113
5114 53. The single man page has become too large. I have therefore split it up into
5115 a number of separate man pages. These also give rise to individual HTML pages;
5116 these are now put in a separate directory, and there is an index.html page that
5117 lists them all. Some hyperlinking between the pages has been installed.
5118
5119 54. Added convenience functions for handling named capturing parentheses.
5120
5121 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
5122 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
5123 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
5124 are faulted.
5125
5126 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
5127 calling configure. These values are used when compiling the dftables.c program
5128 which is run to generate the source of the default character tables. They
5129 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
5130 you will need to set these values.
5131
5132 57. Updated the building process for Windows DLL, as provided by Fred Cox.
5133
5134
5135 Version 3.9 02-Jan-02
5136 ---------------------
5137
5138 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
5139
5140 2. If --disable-static was given, the building process failed when trying to
5141 build pcretest and pcregrep. (For some reason it was using libtool to compile
5142 them, which is not right, as they aren't part of the library.)
5143
5144
5145 Version 3.8 18-Dec-01
5146 ---------------------
5147
5148 1. The experimental UTF-8 code was completely screwed up. It was packing the
5149 bytes in the wrong order. How dumb can you get?
5150
5151
5152 Version 3.7 29-Oct-01
5153 ---------------------
5154
5155 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
5156 This caused pcretest, when used on the test data, to segfault. Unfortunately,
5157 this didn't happen under Solaris 8, where I normally test things.
5158
5159 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
5160 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
5161 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
5162 this fix an hour or so after the initial 3.7 release.)
5163
5164
5165 Version 3.6 23-Oct-01
5166 ---------------------
5167
5168 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
5169 offsets passed as NULL with zero offset count.
5170
5171 2. The config.guess and config.sub files had not been updated when I moved to
5172 the latest autoconf.
5173
5174
5175 Version 3.5 15-Aug-01
5176 ---------------------
5177
5178 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
5179 had been forgotten.
5180
5181 2. By using declared but undefined structures, we can avoid using "void"
5182 definitions in pcre.h while keeping the internal definitions of the structures
5183 private.
5184
5185 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
5186 user point of view, this means that both static and shared libraries are built
5187 by default, but this can be individually controlled. More of the work of
5188 handling this static/shared cases is now inside libtool instead of PCRE's make
5189 file.
5190
5191 4. The pcretest utility is now installed along with pcregrep because it is
5192 useful for users (to test regexs) and by doing this, it automatically gets
5193 relinked by libtool. The documentation has been turned into a man page, so
5194 there are now .1, .txt, and .html versions in /doc.
5195
5196 5. Upgrades to pcregrep:
5197 (i) Added long-form option names like gnu grep.
5198 (ii) Added --help to list all options with an explanatory phrase.
5199 (iii) Added -r, --recursive to recurse into sub-directories.
5200 (iv) Added -f, --file to read patterns from a file.
5201
5202 6. pcre_exec() was referring to its "code" argument before testing that
5203 argument for NULL (and giving an error if it was NULL).
5204
5205 7. Upgraded Makefile.in to allow for compiling in a different directory from
5206 the source directory.
5207
5208 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
5209 options bits, the pointer it was passed was to an int instead of to an unsigned
5210 long int. This mattered only on 64-bit systems.
5211
5212 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
5213 generated) instead of pcre.in, which it its source. Also made the same change
5214 in several of the .c files.
5215
5216 10. A new release of gcc defines printf() as a macro, which broke pcretest
5217 because it had an ifdef in the middle of a string argument for printf(). Fixed
5218 by using separate calls to printf().
5219
5220 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
5221 script, to force use of CR or LF instead of \n in the source. On non-Unix
5222 systems, the value can be set in config.h.
5223
5224 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
5225 absolute limit. Changed the text of the error message to make this clear, and
5226 likewise updated the man page.
5227
5228 13. The limit of 99 on the number of capturing subpatterns has been removed.
5229 The new limit is 65535, which I hope will not be a "real" limit.
5230
5231
5232 Version 3.4 22-Aug-00
5233 ---------------------
5234
5235 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
5236
5237 2. Diagnose condition (?(0) as an error instead of crashing on matching.
5238
5239
5240 Version 3.3 01-Aug-00
5241 ---------------------
5242
5243 1. If an octal character was given, but the value was greater than \377, it
5244 was not getting masked to the least significant bits, as documented. This could
5245 lead to crashes in some systems.
5246
5247 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
5248 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
5249
5250 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
5251 These just pass their arguments on to (pcre_free)(), but they are provided
5252 because some uses of PCRE bind it to non-C systems that can call its functions,
5253 but cannot call free() or pcre_free() directly.
5254
5255 4. Add "make test" as a synonym for "make check". Corrected some comments in
5256 the Makefile.
5257
5258 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
5259 Makefile.
5260
5261 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
5262 command called pgrep for grepping around the active processes.
5263
5264 7. Added the beginnings of support for UTF-8 character strings.
5265
5266 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
5267 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
5268 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
5269 out for the ar command.)
5270
5271
5272 Version 3.2 12-May-00
5273 ---------------------
5274
5275 This is purely a bug fixing release.
5276
5277 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
5278 of ZA. This was just one example of several cases that could provoke this bug,
5279 which was introduced by change 9 of version 2.00. The code for breaking
5280 infinite loops after an iteration that matches an empty string was't working
5281 correctly.
5282
5283 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
5284 when matched against abbab (for example). After matching an empty string, it
5285 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
5286 caused it to match further down the string than it should.
5287
5288 3. The code contained an inclusion of sys/types.h. It isn't clear why this
5289 was there because it doesn't seem to be needed, and it causes trouble on some
5290 systems, as it is not a Standard C header. It has been removed.
5291
5292 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
5293 were reported on the Macintosh. The changes were from
5294
5295 while ((c = *(++ptr)) != 0 && c != '\n');
5296 to
5297 while ((c = *(++ptr)) != 0 && c != '\n') ;
5298
5299 Totally extraordinary, but if that's what it takes...
5300
5301 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
5302 available. Added HAVE_BCOPY and an autoconf test for it; if neither
5303 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
5304 assumes the way PCRE uses memmove() (always moving upwards).
5305
5306 6. PCRE is being used in one environment where strchr() is not available. There
5307 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
5308 faster code anyway.
5309
5310
5311 Version 3.1 09-Feb-00
5312 ---------------------
5313
5314 The only change in this release is the fixing of some bugs in Makefile.in for
5315 the "install" target:
5316
5317 (1) It was failing to install pcreposix.h.
5318
5319 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
5320
5321
5322 Version 3.0 01-Feb-00
5323 ---------------------
5324
5325 1. Add support for the /+ modifier to perltest (to output $` like it does in
5326 pcretest).
5327
5328 2. Add support for the /g modifier to perltest.
5329
5330 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
5331 matches null strings.
5332
5333 4. Fix perltest so that it doesn't do unwanted things when fed an empty
5334 pattern. Perl treats empty patterns specially - it reuses the most recent
5335 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
5336 effect.
5337
5338 5. The POSIX interface was broken in that it was just handing over the POSIX
5339 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
5340 required a bigger vector, with some working space on the end. This means that
5341 the POSIX wrapper now has to get and free some memory, and copy the results.
5342
5343 6. Added some simple autoconf support, placing the test data and the
5344 documentation in separate directories, re-organizing some of the
5345 information files, and making it build pcre-config (a GNU standard). Also added
5346 libtool support for building PCRE as a shared library, which is now the
5347 default.
5348
5349 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
5350 09 are not valid octal constants. Single digits will be used for minor values
5351 less than 10.
5352
5353 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
5354 existing programs that set these in the POSIX interface can use PCRE without
5355 modification.
5356
5357 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
5358 return all that pcre_info() returns, plus additional data. The pcre_info()
5359 function is retained for compatibility, but is considered to be obsolete.
5360
5361 10. Added experimental recursion feature (?R) to handle one common case that
5362 Perl 5.6 will be able to do with (?p{...}).
5363
5364 11. Added support for POSIX character classes like [:alpha:], which Perl is
5365 adopting.
5366
5367
5368 Version 2.08 31-Aug-99
5369 ----------------------
5370
5371 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
5372 trying to match at the startoffset position, but instead was moving forward to
5373 the next newline as if a previous match had failed.
5374
5375 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
5376 and could get into a loop if a null string was matched other than at the start
5377 of the subject.
5378
5379 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
5380 be distinguished at compile time, and for completeness also added PCRE_DATE.
5381
5382 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
5383 in GnuWin32 environments.
5384
5385
5386 Version 2.07 29-Jul-99
5387 ----------------------
5388
5389 1. The documentation is now supplied in plain text form and HTML as well as in
5390 the form of man page sources.
5391
5392 2. C++ compilers don't like assigning (void *) values to other pointer types.
5393 In particular this affects malloc(). Although there is no problem in Standard
5394 C, I've put in casts to keep C++ compilers happy.
5395
5396 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
5397 should be (const char *).
5398
5399 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
5400 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
5401 However, I haven't made this a standard facility. The documentation doesn't
5402 mention it, and the Makefile doesn't support it.
5403
5404 5. The Makefile now contains an "install" target, with editable destinations at
5405 the top of the file. The pcretest program is not installed.
5406
5407 6. pgrep -V now gives the PCRE version number and date.
5408
5409 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
5410 causing the entire string to be ignored, instead of just the last character.
5411
5412 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
5413 non-matching string, it can take a very, very long time, even for strings of
5414 quite modest length, because of the nested recursion. PCRE now does better in
5415 some of these cases. It does this by remembering the last required literal
5416 character in the pattern, and pre-searching the subject to ensure it is present
5417 before running the real match. In other words, it applies a heuristic to detect
5418 some types of certain failure quickly, and in the above example, if presented
5419 with a string that has no trailing " it gives "no match" very quickly.
5420
5421 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
5422 other alternatives are tried instead.
5423
5424
5425 Version 2.06 09-Jun-99
5426 ----------------------
5427
5428 1. Change pcretest's output for amount of store used to show just the code
5429 space, because the remainder (the data block) varies in size between 32-bit and
5430 64-bit systems.
5431
5432 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
5433 start matching at. This allows lookbehinds to work when searching for multiple
5434 occurrences in a string.
5435
5436 3. Added additional options to pcretest for testing multiple occurrences:
5437
5438 /+ outputs the rest of the string that follows a match
5439 /g loops for multiple occurrences, using the new startoffset argument
5440 /G loops for multiple occurrences by passing an incremented pointer
5441
5442 4. PCRE wasn't doing the "first character" optimization for patterns starting
5443 with \b or \B, though it was doing it for other lookbehind assertions. That is,
5444 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
5445 the letter 'x'. On long subject strings, this gives a significant speed-up.
5446
5447
5448 Version 2.05 21-Apr-99
5449 ----------------------
5450
5451 1. Changed the type of magic_number from int to long int so that it works
5452 properly on 16-bit systems.
5453
5454 2. Fixed a bug which caused patterns starting with .* not to work correctly
5455 when the subject string contained newline characters. PCRE was assuming
5456 anchoring for such patterns in all cases, which is not correct because .* will
5457 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
5458 DOTALL is set at top level; otherwise it knows that patterns starting with .*
5459 must be retried after every newline in the subject.
5460
5461
5462 Version 2.04 18-Feb-99
5463 ----------------------
5464
5465 1. For parenthesized subpatterns with repeats whose minimum was zero, the
5466 computation of the store needed to hold the pattern was incorrect (too large).
5467 If such patterns were nested a few deep, this could multiply and become a real
5468 problem.
5469
5470 2. Added /M option to pcretest to show the memory requirement of a specific
5471 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
5472
5473 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
5474 compiled in such a way that the backtracking after subsequent failure was
5475 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
5476 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
5477
5478
5479 Version 2.03 02-Feb-99
5480 ----------------------
5481
5482 1. Fixed typo and small mistake in man page.
5483
5484 2. Added 4th condition (GPL supersedes if conflict) and created separate
5485 LICENCE file containing the conditions.
5486
5487 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
5488 Perl, that is the internal \ allows the delimiter to be included in the
5489 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
5490 the final delimiter, add \ to the end of the pattern (to test the error).
5491
5492 4. Added the convenience functions for extracting substrings after a successful
5493 match. Updated pcretest to make it able to test these functions.
5494
5495
5496 Version 2.02 14-Jan-99
5497 ----------------------
5498
5499 1. Initialized the working variables associated with each extraction so that
5500 their saving and restoring doesn't refer to uninitialized store.
5501
5502 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
5503 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
5504 fix the problem.
5505
5506 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
5507 calls, and wasn't printing the correct value for compiling calls. Increased the
5508 default value of LOOPREPEAT, and the number of significant figures in the
5509 times.
5510
5511 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
5512
5513 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
5514 a building problem on Windows NT with a FAT file system.
5515
5516
5517 Version 2.01 21-Oct-98
5518 ----------------------
5519
5520 1. Changed the API for pcre_compile() to allow for the provision of a pointer
5521 to character tables built by pcre_maketables() in the current locale. If NULL
5522 is passed, the default tables are used.
5523
5524
5525 Version 2.00 24-Sep-98
5526 ----------------------
5527
5528 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
5529 it any more.
5530
5531 2. Allow quantification of (?>) groups, and make it work correctly.
5532
5533 3. The first character computation wasn't working for (?>) groups.
5534
5535 4. Correct the implementation of \Z (it is permitted to match on the \n at the
5536 end of the subject) and add 5.005's \z, which really does match only at the
5537 very end of the subject.
5538
5539 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
5540
5541 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
5542 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
5543 localized options. All options to pcre_study() were also removed.
5544
5545 7. Add other new features from 5.005:
5546
5547 $(?<= positive lookbehind
5548 $(?<! negative lookbehind
5549 (?imsx-imsx) added the unsetting capability
5550 such a setting is global if at outer level; local otherwise
5551 (?imsx-imsx:) non-capturing groups with option setting
5552 (?(cond)re|re) conditional pattern matching
5553
5554 A backreference to itself in a repeated group matches the previous
5555 captured string.
5556
5557 8. General tidying up of studying (both automatic and via "study")
5558 consequential on the addition of new assertions.
5559
5560 9. As in 5.005, unlimited repeated groups that could match an empty substring
5561 are no longer faulted at compile time. Instead, the loop is forcibly broken at
5562 runtime if any iteration does actually match an empty substring.
5563
5564 10. Include the RunTest script in the distribution.
5565
5566 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
5567 discrepancies, some of which were old and were also with respect to 5.004. They
5568 have now been fixed.
5569
5570
5571 Version 1.09 28-Apr-98
5572 ----------------------
5573
5574 1. A negated single character class followed by a quantifier with a minimum
5575 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
5576 program crashes, or just wrong answers. This did not apply to negated classes
5577 containing more than one character, or to minima other than one.
5578
5579
5580 Version 1.08 27-Mar-98
5581 ----------------------
5582
5583 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
5584
5585 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
5586 latter must appear before anything that relies on it in the pattern.
5587
5588
5589 Version 1.07 16-Feb-98
5590 ----------------------
5591
5592 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
5593 repeat of a potentially empty string).
5594
5595
5596 Version 1.06 23-Jan-98
5597 ----------------------
5598
5599 1. Added Markus Oberhumer's little patches for C++.
5600
5601 2. Literal strings longer than 255 characters were broken.
5602
5603
5604 Version 1.05 23-Dec-97
5605 ----------------------
5606
5607 1. Negated character classes containing more than one character were failing if
5608 PCRE_CASELESS was set at run time.
5609
5610
5611 Version 1.04 19-Dec-97
5612 ----------------------
5613
5614 1. Corrected the man page, where some "const" qualifiers had been omitted.
5615
5616 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
5617 input syntax.
5618
5619 3. Fixed memory leak which occurred when a regex with back references was
5620 matched with an offsets vector that wasn't big enough. The temporary memory
5621 that is used in this case wasn't being freed if the match failed.
5622
5623 4. Tidied pcretest to ensure it frees memory that it gets.
5624
5625 5. Temporary memory was being obtained in the case where the passed offsets
5626 vector was exactly big enough.
5627
5628 6. Corrected definition of offsetof() from change 5 below.
5629
5630 7. I had screwed up change 6 below and broken the rules for the use of
5631 setjmp(). Now fixed.
5632
5633
5634 Version 1.03 18-Dec-97
5635 ----------------------
5636
5637 1. A erroneous regex with a missing opening parenthesis was correctly
5638 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
5639 on some systems.
5640
5641 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
5642 it was reported that one broken compiler failed on the former because "code" is
5643 also an independent variable.
5644
5645 3. The erroneous regex a[]b caused an array overrun reference.
5646
5647 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
5648 fail on data ending with that character. (It was going on too far, and checking
5649 the next character, typically a binary zero.) This was specific to the
5650 optimized code for single-character negative classes.
5651
5652 5. Added a contributed patch from the TIN world which does the following:
5653
5654 + Add an undef for memmove, in case the the system defines a macro for it.
5655
5656 + Add a definition of offsetof(), in case there isn't one. (I don't know
5657 the reason behind this - offsetof() is part of the ANSI standard - but
5658 it does no harm).
5659
5660 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
5661 most of the places where whitespace preceded '#'. I have given up and
5662 allowed the remaining 2 cases to be at the margin.
5663
5664 + Rename some variables in pcre to eliminate shadowing. This seems very
5665 pedantic, but does no harm, of course.
5666
5667 6. Moved the call to setjmp() into its own function, to get rid of warnings
5668 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
5669
5670 7. Constructs such as \d{8,} were compiling into the equivalent of
5671 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
5672 outcome, but in this particular case used more store than had been allocated,
5673 which caused the bug to be discovered because it threw up an internal error.
5674
5675 8. The debugging code in both pcre and pcretest for outputting the compiled
5676 form of a regex was going wrong in the case of back references followed by
5677 curly-bracketed repeats.
5678
5679
5680 Version 1.02 12-Dec-97
5681 ----------------------
5682
5683 1. Typos in pcre.3 and comments in the source fixed.
5684
5685 2. Applied a contributed patch to get rid of places where it used to remove
5686 'const' from variables, and fixed some signed/unsigned and uninitialized
5687 variable warnings.
5688
5689 3. Added the "runtest" target to Makefile.
5690
5691 4. Set default compiler flag to -O2 rather than just -O.
5692
5693
5694 Version 1.01 19-Nov-97
5695 ----------------------
5696
5697 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
5698 like /([ab]*)*/, that is, for classes with more than one character in them.
5699
5700 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
5701 as /((?>a*))*/ (a PCRE_EXTRA facility).
5702
5703
5704 Version 1.00 18-Nov-97
5705 ----------------------
5706
5707 1. Added compile-time macros to support systems such as SunOS4 which don't have
5708 memmove() or strerror() but have other things that can be used instead.
5709
5710 2. Arranged that "make clean" removes the executables.
5711
5712
5713 Version 0.99 27-Oct-97
5714 ----------------------
5715
5716 1. Fixed bug in code for optimizing classes with only one character. It was
5717 initializing a 32-byte map regardless, which could cause it to run off the end
5718 of the memory it had got.
5719
5720 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
5721
5722
5723 Version 0.98 22-Oct-97
5724 ----------------------
5725
5726 1. Fixed bug in code for handling temporary memory usage when there are more
5727 back references than supplied space in the ovector. This could cause segfaults.
5728
5729
5730 Version 0.97 21-Oct-97
5731 ----------------------
5732
5733 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
5734
5735 2. Optimized negated single characters not to use a bit map.
5736
5737 3. Brought error texts together as macro definitions; clarified some of them;
5738 fixed one that was wrong - it said "range out of order" when it meant "invalid
5739 escape sequence".
5740
5741 4. Changed some char * arguments to const char *.
5742
5743 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
5744
5745 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
5746 pcretest.
5747
5748
5749 Version 0.96 16-Oct-97
5750 ----------------------
5751
5752 1. Added a simple "pgrep" utility to the distribution.
5753
5754 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
5755 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
5756 where "ddd" means "one or more decimal digits".
5757
5758 3. Fixed serious bug. If a pattern had a back reference, but the call to
5759 pcre_exec() didn't supply a large enough ovector to record the related
5760 identifying subpattern, the match always failed. PCRE now remembers the number
5761 of the largest back reference, and gets some temporary memory in which to save
5762 the offsets during matching if necessary, in order to ensure that
5763 backreferences always work.
5764
5765 4. Increased the compatibility with Perl in a number of ways:
5766
5767 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
5768 to request this handling. The option can be set at compile or exec time.
5769
5770 (b) $ matches before a terminating newline by default; an option
5771 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
5772 mode). The option can be set at compile or exec time.
5773
5774 (c) The handling of \ followed by a digit other than 0 is now supposed to be
5775 the same as Perl's. If the decimal number it represents is less than 10
5776 or there aren't that many previous left capturing parentheses, an octal
5777 escape is read. Inside a character class, it's always an octal escape,
5778 even if it is a single digit.
5779
5780 (d) An escaped but undefined alphabetic character is taken as a literal,
5781 unless PCRE_EXTRA is set. Currently this just reserves the remaining
5782 escapes.
5783
5784 (e) {0} is now permitted. (The previous item is removed from the compiled
5785 pattern).
5786
5787 5. Changed all the names of code files so that the basic parts are no longer
5788 than 10 characters, and abolished the teeny "globals.c" file.
5789
5790 6. Changed the handling of character classes; they are now done with a 32-byte
5791 bit map always.
5792
5793 7. Added the -d and /D options to pcretest to make it possible to look at the
5794 internals of compilation without having to recompile pcre.
5795
5796
5797 Version 0.95 23-Sep-97
5798 ----------------------
5799
5800 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
5801 \x20 at the start of a run of normal characters. These were being treated as
5802 real characters, instead of the source characters being re-checked.
5803
5804
5805 Version 0.94 18-Sep-97
5806 ----------------------
5807
5808 1. The functions are now thread-safe, with the caveat that the global variables
5809 containing pointers to malloc() and free() or alternative functions are the
5810 same for all threads.
5811
5812 2. Get pcre_study() to generate a bitmap of initial characters for non-
5813 anchored patterns when this is possible, and use it if passed to pcre_exec().
5814
5815
5816 Version 0.93 15-Sep-97
5817 ----------------------
5818
5819 1. /(b)|(:+)/ was computing an incorrect first character.
5820
5821 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
5822 but not actually doing anything yet.
5823
5824 3. Treat "-" characters in classes that cannot be part of ranges as literals,
5825 as Perl does (e.g. [-az] or [az-]).
5826
5827 4. Set the anchored flag if a branch starts with .* or .*? because that tests
5828 all possible positions.
5829
5830 5. Split up into different modules to avoid including unneeded functions in a
5831 compiled binary. However, compile and exec are still in one module. The "study"
5832 function is split off.
5833
5834 6. The character tables are now in a separate module whose source is generated
5835 by an auxiliary program - but can then be edited by hand if required. There are
5836 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
5837 toupper() in the code.
5838
5839 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
5840 make them global. Abolish the function for setting them, as the caller can now
5841 set them directly.
5842
5843
5844 Version 0.92 11-Sep-97
5845 ----------------------
5846
5847 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
5848 (e.g. /a{1,3}/) was broken (I mis-optimized it).
5849
5850 2. Caseless matching was not working in character classes if the characters in
5851 the pattern were in upper case.
5852
5853 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
5854
5855 4. Make PCRE_ANCHORED public and accept as a compile option.
5856
5857 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
5858 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
5859 pass them.
5860
5861 6. Give an error if bad option bits passed at compile or run time.
5862
5863 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
5864 pcretest to cause it to pass that flag.
5865
5866 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
5867 options, and the first character, if set.
5868
5869 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
5870
5871
5872 Version 0.91 10-Sep-97
5873 ----------------------
5874
5875 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
5876 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
5877
5878 2. PCRE was looping on encountering an indefinitely repeated back reference to
5879 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
5880 Perl does - treats the match as successful.
5881
5882 ****

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