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Revision 118 - (show annotations) (download)
Fri Mar 9 16:17:46 2007 UTC (7 years, 7 months ago) by ph10
File size: 125025 byte(s)
Fix bug in emulated memmove() for downward moves.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.1 05-Mar-07
5 ---------------------
6
7 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
8 that is more "standard", making use of automake and other autotools. There
9 is some re-arrangement of the files and adjustment of comments consequent
10 on this.
11
12 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
13 for recursive directory scanning broke on some systems because the files
14 are not scanned in any specific order and on different systems the order
15 was different. A call to "sort" has been inserted into RunGrepTest for the
16 approprate test as a short-term fix. In the longer term there may be an
17 alternative.
18
19 3. I had an email from Eric Raymond about problems translating some of PCRE's
20 man pages to HTML (despite the fact that I distribute HTML pages, some
21 people do their own conversions for various reasons). The problems
22 concerned the use of low-level troff macros .br and .in. I have therefore
23 removed all such uses from the man pages (some were redundant, some could
24 be replaced by .nf/.fi pairs). The 132html script that I use to generate
25 HTML has been updated to handle .nf/.fi and to complain if it encounters
26 .br or .in.
27
28 4. Updated comments in configure.ac that get placed in config.h.in and also
29 arranged for config.h to be included in the distribution, with the name
30 config.h.generic, for the benefit of those who have to compile without
31 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
32
33 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
34 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
35 makevp.bat for the current PCRE, using the additional files !compile.txt,
36 !linklib.txt, and pcregexp.pas.
37
38 6. A Windows user reported a minor discrepancy with test 2, which turned out
39 to be caused by a trailing space on an input line that had got lost in his
40 copy. The trailing space was an accident, so I've just removed it.
41
42 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
43 that is needed.
44
45 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
46 as "const" (a) because they are and (b) because it helps the PHP
47 maintainers who have recently made a script to detect big data structures
48 in the php code that should be moved to the .rodata section. I remembered
49 to update Builducptable as well, so it won't revert if ucptable.h is ever
50 re-created.
51
52 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
53 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
54 order to be able to cut out the UTF-8 tables in the latter when UTF-8
55 support is not required. This saves 1.5-2K of code, which is important in
56 some applications.
57
58 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
59 so as not to refer to the tables, even though these functions will never be
60 called when UTF-8 support is disabled. Otherwise there are problems with a
61 shared library.
62
63 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
64
65 (a) It was defining its arguments as char * instead of void *.
66
67 (b) It was assuming that all moves were upwards in memory; this was true
68 a long time ago when I wrote it, but is no longer the case.
69
70 The emulated memove() is provided for those environments that have neither
71 memmove() nor bcopy(). I didn't think anyone used it these days, but that
72 is clearly not the case, as these two bugs were recently reported.
73
74 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
75 and Detrail to create the HTML documentation, the .txt form of the man
76 pages, and it removes trailing spaces from listed files. It also creates
77 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
78 case, it wraps all the #defines with #ifndefs. This script should be run
79 before "make dist".
80
81 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
82 with Unicode property support.
83
84 (a) For a maximizing quantifier, if the two different cases of the
85 character were of different lengths in their UTF-8 codings (there are
86 some cases like this - I found 11), and the matching function had to
87 back up over a mixture of the two cases, it incorrectly assumed they
88 were both the same length.
89
90 (b) When PCRE was configured to use the heap rather than the stack for
91 recursion during matching, it was not correctly preserving the data for
92 the other case of a UTF-8 character when checking ahead for a match
93 while processing a minimizing repeat. If the check also involved
94 matching a wide character, but failed, corruption could cause an
95 erroneous result when trying to check for a repeat of the original
96 character.
97
98 13. Some tidying changes to the testing mechanism:
99
100 (a) The RunTest script now detects the internal link size and whether there
101 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
102 values substituted by "configure". (The RunGrepTest script already did
103 this for UTF-8.) The configure.ac script no longer substitutes the
104 relevant variables.
105
106 (b) The debugging options /B and /D in pcretest show the compiled bytecode
107 with length and offset values. This means that the output is different
108 for different internal link sizes. Test 2 is skipped for link sizes
109 other than 2 because of this, bypassing the problem. Unfortunately,
110 there was also a test in test 3 (the locale tests) that used /B and
111 failed for link sizes other than 2. Rather than cut the whole test out,
112 I have added a new /Z option to pcretest that replaces the length and
113 offset values with spaces. This is now used to make test 3 independent
114 of link size.
115
116
117 Version 7.0 19-Dec-06
118 ---------------------
119
120 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
121 moving to gcc 4.1.1.
122
123 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
124 sys/time.h, which is documented as needed for this function. It doesn't
125 seem to matter on Linux, but it showed up on some releases of OS X.
126
127 3. It seems that there are systems where bytes whose values are greater than
128 127 match isprint() in the "C" locale. The "C" locale should be the
129 default when a C program starts up. In most systems, only ASCII printing
130 characters match isprint(). This difference caused the output from pcretest
131 to vary, making some of the tests fail. I have changed pcretest so that:
132
133 (a) When it is outputting text in the compiled version of a pattern, bytes
134 other than 32-126 are always shown as hex escapes.
135
136 (b) When it is outputting text that is a matched part of a subject string,
137 it does the same, unless a different locale has been set for the match
138 (using the /L modifier). In this case, it uses isprint() to decide.
139
140 4. Fixed a major bug that caused incorrect computation of the amount of memory
141 required for a compiled pattern when options that changed within the
142 pattern affected the logic of the preliminary scan that determines the
143 length. The relevant options are -x, and -i in UTF-8 mode. The result was
144 that the computed length was too small. The symptoms of this bug were
145 either the PCRE error "internal error: code overflow" from pcre_compile(),
146 or a glibc crash with a message such as "pcretest: free(): invalid next
147 size (fast)". Examples of patterns that provoked this bug (shown in
148 pcretest format) are:
149
150 /(?-x: )/x
151 /(?x)(?-x: \s*#\s*)/
152 /((?i)[\x{c0}])/8
153 /(?i:[\x{c0}])/8
154
155 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
156 is now done differently.
157
158 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
159 wrapper classes; (b) implement a new function in the C++ scanner that is
160 more efficient than the old way of doing things because it avoids levels of
161 recursion in the regex matching; (c) add a paragraph to the documentation
162 for the FullMatch() function.
163
164 6. The escape sequence \n was being treated as whatever was defined as
165 "newline". Not only was this contrary to the documentation, which states
166 that \n is character 10 (hex 0A), but it also went horribly wrong when
167 "newline" was defined as CRLF. This has been fixed.
168
169 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
170 was being set to -1 for the "end of line" case (supposedly a value that no
171 character can have). Though this value is never used (the check for end of
172 line is "zero bytes in current character"), it caused compiler complaints.
173 I've changed it to 0xffffffff.
174
175 8. In pcre_version.c, the version string was being built by a sequence of
176 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
177 string (as it is for production releases) called a macro with an empty
178 argument. The C standard says the result of this is undefined. The gcc
179 compiler treats it as an empty string (which was what was wanted) but it is
180 reported that Visual C gives an error. The source has been hacked around to
181 avoid this problem.
182
183 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
184 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
185 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
186 of them did).
187
188 10. Originally, pcretest opened its input and output without "b"; then I was
189 told that "b" was needed in some environments, so it was added for release
190 5.0 to both the input and output. (It makes no difference on Unix-like
191 systems.) Later I was told that it is wrong for the input on Windows. I've
192 now abstracted the modes into two macros, to make it easier to fiddle with
193 them, and removed "b" from the input mode under Windows.
194
195 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
196
197 12. Added -help and --help to pcretest as an official way of being reminded
198 of the options.
199
200 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
201 and pcrecpp.cc because they annoy compilers at high warning levels.
202
203 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
204
205 15. Fixed an occurrence of == in configure.ac that should have been = (shell
206 scripts are not C programs :-) and which was not noticed because it works
207 on Linux.
208
209 16. pcretest is supposed to handle any length of pattern and data line (as one
210 line or as a continued sequence of lines) by extending its input buffer if
211 necessary. This feature was broken for very long pattern lines, leading to
212 a string of junk being passed to pcre_compile() if the pattern was longer
213 than about 50K.
214
215 17. I have done a major re-factoring of the way pcre_compile() computes the
216 amount of memory needed for a compiled pattern. Previously, there was code
217 that made a preliminary scan of the pattern in order to do this. That was
218 OK when PCRE was new, but as the facilities have expanded, it has become
219 harder and harder to keep it in step with the real compile phase, and there
220 have been a number of bugs (see for example, 4 above). I have now found a
221 cunning way of running the real compile function in a "fake" mode that
222 enables it to compute how much memory it would need, while actually only
223 ever using a few hundred bytes of working memory and without too many
224 tests of the mode. This should make future maintenance and development
225 easier. A side effect of this work is that the limit of 200 on the nesting
226 depth of parentheses has been removed (though this was never a serious
227 limitation, I suspect). However, there is a downside: pcre_compile() now
228 runs more slowly than before (30% or more, depending on the pattern). I
229 hope this isn't a big issue. There is no effect on runtime performance.
230
231 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
232 newline (only possible for the last line of a file) and it was a
233 pattern that set a locale (followed by /Lsomething), pcretest crashed.
234
235 19. Added additional timing features to pcretest. (1) The -tm option now times
236 matching only, not compiling. (2) Both -t and -tm can be followed, as a
237 separate command line item, by a number that specifies the number of
238 repeats to use when timing. The default is 50000; this gives better
239 precision, but takes uncomfortably long for very large patterns.
240
241 20. Extended pcre_study() to be more clever in cases where a branch of a
242 subpattern has no definite first character. For example, (a*|b*)[cd] would
243 previously give no result from pcre_study(). Now it recognizes that the
244 first character must be a, b, c, or d.
245
246 21. There was an incorrect error "recursive call could loop indefinitely" if
247 a subpattern (or the entire pattern) that was being tested for matching an
248 empty string contained only one non-empty item after a nested subpattern.
249 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
250 incorrectly, because the \d was being skipped in the check.
251
252 22. The pcretest program now has a new pattern option /B and a command line
253 option -b, which is equivalent to adding /B to every pattern. This causes
254 it to show the compiled bytecode, without the additional information that
255 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
256 is the same as /B/I).
257
258 23. A new optimization is now able automatically to treat some sequences such
259 as a*b as a*+b. More specifically, if something simple (such as a character
260 or a simple class like \d) has an unlimited quantifier, and is followed by
261 something that cannot possibly match the quantified thing, the quantifier
262 is automatically "possessified".
263
264 24. A recursive reference to a subpattern whose number was greater than 39
265 went wrong under certain circumstances in UTF-8 mode. This bug could also
266 have affected the operation of pcre_study().
267
268 25. Realized that a little bit of performance could be had by replacing
269 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
270
271 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
272
273 27. Possessive quantifiers such as a++ were previously implemented by turning
274 them into atomic groups such as ($>a+). Now they have their own opcodes,
275 which improves performance. This includes the automatically created ones
276 from 23 above.
277
278 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
279 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
280 the first matched character to be a colon. This applied both to named and
281 numbered groups.
282
283 29. The ucpinternal.h header file was missing its idempotency #ifdef.
284
285 30. I was sent a "project" file called libpcre.a.dev which I understand makes
286 building PCRE on Windows easier, so I have included it in the distribution.
287
288 31. There is now a check in pcretest against a ridiculously large number being
289 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
290 loop, the loop is abandoned.
291
292 32. Forward references to subpatterns in conditions such as (?(2)...) where
293 subpattern 2 is defined later cause pcre_compile() to search forwards in
294 the pattern for the relevant set of parentheses. This search went wrong
295 when there were unescaped parentheses in a character class, parentheses
296 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
297
298 33. "Subroutine" calls and backreferences were previously restricted to
299 referencing subpatterns earlier in the regex. This restriction has now
300 been removed.
301
302 34. Added a number of extra features that are going to be in Perl 5.10. On the
303 whole, these are just syntactic alternatives for features that PCRE had
304 previously implemented using the Python syntax or my own invention. The
305 other formats are all retained for compatibility.
306
307 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
308 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
309 also .NET compatible.
310
311 (b) A recursion or subroutine call to a named group can now be defined as
312 (?&name) as well as (?P>name).
313
314 (c) A backreference to a named group can now be defined as \k<name> or
315 \k'name' as well as (?P=name). The new forms, as well as being in Perl
316 5.10, are also .NET compatible.
317
318 (d) A conditional reference to a named group can now use the syntax
319 (?(<name>) or (?('name') as well as (?(name).
320
321 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
322 groups (named and numbered) that are never evaluated inline, but can be
323 called as "subroutines" from elsewhere. In effect, the DEFINE condition
324 is always false. There may be only one alternative in such a group.
325
326 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
327 as the simple (?(R). The condition is true only if the most recent
328 recursion is that of the given number or name. It does not search out
329 through the entire recursion stack.
330
331 (g) The escape \gN or \g{N} has been added, where N is a positive or
332 negative number, specifying an absolute or relative reference.
333
334 35. Tidied to get rid of some further signed/unsigned compiler warnings and
335 some "unreachable code" warnings.
336
337 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
338 things, this adds five new scripts.
339
340 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
341 There were also incompatibilities regarding the handling of \Q..\E inside
342 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
343 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
344
345 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
346 matches an empty string, and forcibly breaks the loop. There were bugs in
347 this code in non-simple cases. For a pattern such as ^(a()*)* matched
348 against aaaa the result was just "a" rather than "aaaa", for example. Two
349 separate and independent bugs (that affected different cases) have been
350 fixed.
351
352 39. Refactored the code to abolish the use of different opcodes for small
353 capturing bracket numbers. This is a tidy that I avoided doing when I
354 removed the limit on the number of capturing brackets for 3.5 back in 2001.
355 The new approach is not only tidier, it makes it possible to reduce the
356 memory needed to fix the previous bug (38).
357
358 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
359 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
360 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
361 mode.
362
363 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
364 report.
365
366 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
367 copy construction and assignment in the C++ wrapper.
368
369 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
370 couple of bugs that could have given wrong results in the "--newline=crlf"
371 case.
372
373 44. Added a number of casts and did some reorganization of signed/unsigned int
374 variables following suggestions from Dair Grant. Also renamed the variable
375 "this" as "item" because it is a C++ keyword.
376
377 45. Arranged for dftables to add
378
379 #include "pcre_internal.h"
380
381 to pcre_chartables.c because without it, gcc 4.x may remove the array
382 definition from the final binary if PCRE is built into a static library and
383 dead code stripping is activated.
384
385 46. For an unanchored pattern, if a match attempt fails at the start of a
386 newline sequence, and the newline setting is CRLF or ANY, and the next two
387 characters are CRLF, advance by two characters instead of one.
388
389
390 Version 6.7 04-Jul-06
391 ---------------------
392
393 1. In order to handle tests when input lines are enormously long, pcretest has
394 been re-factored so that it automatically extends its buffers when
395 necessary. The code is crude, but this _is_ just a test program. The
396 default size has been increased from 32K to 50K.
397
398 2. The code in pcre_study() was using the value of the re argument before
399 testing it for NULL. (Of course, in any sensible call of the function, it
400 won't be NULL.)
401
402 3. The memmove() emulation function in pcre_internal.h, which is used on
403 systems that lack both memmove() and bcopy() - that is, hardly ever -
404 was missing a "static" storage class specifier.
405
406 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
407 containing an extended class (one that cannot be represented by a bitmap
408 because it contains high-valued characters or Unicode property items, e.g.
409 [\pZ]). Almost always one would set UTF-8 mode when processing such a
410 pattern, but PCRE should not loop if you do not (it no longer does).
411 [Detail: two cases were found: (a) a repeated subpattern containing an
412 extended class; (b) a recursive reference to a subpattern that followed a
413 previous extended class. It wasn't skipping over the extended class
414 correctly when UTF-8 mode was not set.]
415
416 5. A negated single-character class was not being recognized as fixed-length
417 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
418 compile error "lookbehind assertion is not fixed length".
419
420 6. The RunPerlTest auxiliary script was showing an unexpected difference
421 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
422 write a Perl script that can interpret lines of an input file either as
423 byte characters or as UTF-8, which is what "perltest" was being required to
424 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
425 can't do is switch easily at run time between having the "use utf8;" pragma
426 or not. In the end, I fudged it by using the RunPerlTest script to insert
427 "use utf8;" explicitly for the UTF-8 tests.
428
429 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
430 the end of the subject string, contrary to the documentation and to what
431 Perl does. This was true of both matching functions. Now it matches only at
432 the start of the subject and immediately after *internal* newlines.
433
434 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
435 a pointer to an int instead of a pointer to an unsigned long int. This
436 caused problems on 64-bit systems.
437
438 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
439 instance of the 'standard' template library not being so standard".
440
441 10. There was no check on the number of named subpatterns nor the maximum
442 length of a subpattern name. The product of these values is used to compute
443 the size of the memory block for a compiled pattern. By supplying a very
444 long subpattern name and a large number of named subpatterns, the size
445 computation could be caused to overflow. This is now prevented by limiting
446 the length of names to 32 characters, and the number of named subpatterns
447 to 10,000.
448
449 11. Subpatterns that are repeated with specific counts have to be replicated in
450 the compiled pattern. The size of memory for this was computed from the
451 length of the subpattern and the repeat count. The latter is limited to
452 65535, but there was no limit on the former, meaning that integer overflow
453 could in principle occur. The compiled length of a repeated subpattern is
454 now limited to 30,000 bytes in order to prevent this.
455
456 12. Added the optional facility to have named substrings with the same name.
457
458 13. Added the ability to use a named substring as a condition, using the
459 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
460 are numbers (not recommended). Forward references are permitted.
461
462 14. Added forward references in named backreferences (if you see what I mean).
463
464 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
465 pattern could run off the end of the subject. For example, the pattern
466 "(?s)(.{1,5})"8 did this with the subject "ab".
467
468 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
469 PCRE_CASELESS was set when matching characters that were quantified with ?
470 or *.
471
472 17. A character class other than a single negated character that had a minimum
473 but no maximum quantifier - for example [ab]{6,} - was not handled
474 correctly by pce_dfa_exec(). It would match only one character.
475
476 18. A valid (though odd) pattern that looked like a POSIX character
477 class but used an invalid character after [ (for example [[,abc,]]) caused
478 pcre_compile() to give the error "Failed: internal error: code overflow" or
479 in some cases to crash with a glibc free() error. This could even happen if
480 the pattern terminated after [[ but there just happened to be a sequence of
481 letters, a binary zero, and a closing ] in the memory that followed.
482
483 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
484 over the years. Originally (before any Unicode support), just the bottom 8
485 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
486 output from "man perlunicode" includes this:
487
488 The regular expression compiler produces polymorphic opcodes. That
489 is, the pattern adapts to the data and automatically switches to
490 the Unicode character scheme when presented with Unicode data--or
491 instead uses a traditional byte scheme when presented with byte
492 data.
493
494 Sadly, a wide octal escape does not cause a switch, and in a string with
495 no other multibyte characters, these octal escapes are treated as before.
496 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
497 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
498 Unicode string.
499
500 I have not perpetrated such confusion in PCRE. Up till now, it took just
501 the bottom 8 bits, as in old Perl. I have now made octal escapes with
502 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
503 translate to the appropriate multibyte character.
504
505 29. Applied some refactoring to reduce the number of warnings from Microsoft
506 and Borland compilers. This has included removing the fudge introduced
507 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
508 a warning about an unused variable.
509
510 21. PCRE has not included VT (character 0x0b) in the set of whitespace
511 characters since release 4.0, because Perl (from release 5.004) does not.
512 [Or at least, is documented not to: some releases seem to be in conflict
513 with the documentation.] However, when a pattern was studied with
514 pcre_study() and all its branches started with \s, PCRE still included VT
515 as a possible starting character. Of course, this did no harm; it just
516 caused an unnecessary match attempt.
517
518 22. Removed a now-redundant internal flag bit that recorded the fact that case
519 dependency changed within the pattern. This was once needed for "required
520 byte" processing, but is no longer used. This recovers a now-scarce options
521 bit. Also moved the least significant internal flag bit to the most-
522 significant bit of the word, which was not previously used (hangover from
523 the days when it was an int rather than a uint) to free up another bit for
524 the future.
525
526 23. Added support for CRLF line endings as well as CR and LF. As well as the
527 default being selectable at build time, it can now be changed at runtime
528 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
529 specify that it is scanning data with non-default line endings.
530
531 24. Changed the definition of CXXLINK to make it agree with the definition of
532 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
533
534 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
535 recursions. This makes a big different to stack usage for some patterns.
536
537 26. If a subpattern containing a named recursion or subroutine reference such
538 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
539 the space required for the compiled pattern went wrong and gave too small a
540 value. Depending on the environment, this could lead to "Failed: internal
541 error: code overflow at offset 49" or "glibc detected double free or
542 corruption" errors.
543
544 27. Applied patches from Google (a) to support the new newline modes and (b) to
545 advance over multibyte UTF-8 characters in GlobalReplace.
546
547 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
548 difference for some implementation of PCRE in some Windows version.
549
550 29. Added some extra testing facilities to pcretest:
551
552 \q<number> in a data line sets the "match limit" value
553 \Q<number> in a data line sets the "match recursion limt" value
554 -S <number> sets the stack size, where <number> is in megabytes
555
556 The -S option isn't available for Windows.
557
558
559 Version 6.6 06-Feb-06
560 ---------------------
561
562 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
563 in pcreposix.h. I have copied the definition from pcre.h.
564
565 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
566 because pcre.h is no longer a built file.
567
568 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
569 not normally included in the compiled code.
570
571
572 Version 6.5 01-Feb-06
573 ---------------------
574
575 1. When using the partial match feature with pcre_dfa_exec(), it was not
576 anchoring the second and subsequent partial matches at the new starting
577 point. This could lead to incorrect results. For example, with the pattern
578 /1234/, partially matching against "123" and then "a4" gave a match.
579
580 2. Changes to pcregrep:
581
582 (a) All non-match returns from pcre_exec() were being treated as failures
583 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
584 error message is output. Some extra information is given for the
585 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
586 probably the only errors that are likely to be caused by users (by
587 specifying a regex that has nested indefinite repeats, for instance).
588 If there are more than 20 of these errors, pcregrep is abandoned.
589
590 (b) A binary zero was treated as data while matching, but terminated the
591 output line if it was written out. This has been fixed: binary zeroes
592 are now no different to any other data bytes.
593
594 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
595 used to set a locale for matching. The --locale=xxxx long option has
596 been added (no short equivalent) to specify a locale explicitly on the
597 pcregrep command, overriding the environment variables.
598
599 (d) When -B was used with -n, some line numbers in the output were one less
600 than they should have been.
601
602 (e) Added the -o (--only-matching) option.
603
604 (f) If -A or -C was used with -c (count only), some lines of context were
605 accidentally printed for the final match.
606
607 (g) Added the -H (--with-filename) option.
608
609 (h) The combination of options -rh failed to suppress file names for files
610 that were found from directory arguments.
611
612 (i) Added the -D (--devices) and -d (--directories) options.
613
614 (j) Added the -F (--fixed-strings) option.
615
616 (k) Allow "-" to be used as a file name for -f as well as for a data file.
617
618 (l) Added the --colo(u)r option.
619
620 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
621 is not present by default.
622
623 3. A nasty bug was discovered in the handling of recursive patterns, that is,
624 items such as (?R) or (?1), when the recursion could match a number of
625 alternatives. If it matched one of the alternatives, but subsequently,
626 outside the recursion, there was a failure, the code tried to back up into
627 the recursion. However, because of the way PCRE is implemented, this is not
628 possible, and the result was an incorrect result from the match.
629
630 In order to prevent this happening, the specification of recursion has
631 been changed so that all such subpatterns are automatically treated as
632 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
633
634 4. I had overlooked the fact that, in some locales, there are characters for
635 which isalpha() is true but neither isupper() nor islower() are true. In
636 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
637 and ordfeminine) are like this. This affected the treatment of \w and \W
638 when they appeared in character classes, but not when they appeared outside
639 a character class. The bit map for "word" characters is now created
640 separately from the results of isalnum() instead of just taking it from the
641 upper, lower, and digit maps. (Plus the underscore character, of course.)
642
643 5. The above bug also affected the handling of POSIX character classes such as
644 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
645 permanent tables. Instead, the bit maps for such a class were previously
646 created as the appropriate unions of the upper, lower, and digit bitmaps.
647 Now they are created by subtraction from the [[:word:]] class, which has
648 its own bitmap.
649
650 6. The [[:blank:]] character class matches horizontal, but not vertical space.
651 It is created by subtracting the vertical space characters (\x09, \x0a,
652 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
653 subtraction was done in the overall bitmap for a character class, meaning
654 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
655 be recognized. This bug has been fixed.
656
657 7. Patches from the folks at Google:
658
659 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
660 real life, but is still worth protecting against".
661
662 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
663 regular expressions".
664
665 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
666 have it.
667
668 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
669 "configure" and the latter not, in order to fix a problem somebody had
670 with compiling the Arg class on HP-UX.
671
672 (e) Improve the error-handling of the C++ wrapper a little bit.
673
674 (f) New tests for checking recursion limiting.
675
676 8. The pcre_memmove() function, which is used only if the environment does not
677 have a standard memmove() function (and is therefore rarely compiled),
678 contained two bugs: (a) use of int instead of size_t, and (b) it was not
679 returning a result (though PCRE never actually uses the result).
680
681 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
682 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
683 returned instead of calling malloc() with an overflowing number that would
684 most likely cause subsequent chaos.
685
686 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
687
688 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
689 with this option is matched, the nmatch and pmatch options of regexec() are
690 ignored.
691
692 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
693 provided in case anyone wants to the the POSIX interface with UTF-8
694 strings.
695
696 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
697 C++ linking (needed for some HP-UX environments).
698
699 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
700 (unused parameter) and in the pcre_printint() function (omitted "default"
701 switch label when the default is to do nothing).
702
703 15. Added some code to make it possible, when PCRE is compiled as a C++
704 library, to replace subject pointers for pcre_exec() with a smart pointer
705 class, thus making it possible to process discontinuous strings.
706
707 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
708 much the same function. They were added by different people who were trying
709 to make PCRE easy to compile on non-Unix systems. It has been suggested
710 that PCRE_EXPORT be abolished now that there is more automatic apparatus
711 for compiling on Windows systems. I have therefore replaced it with
712 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
713 defaults to "extern" for C or "extern C" for C++, which works fine on
714 Unix-like systems. It is now possible to override the value of PCRE_DATA_
715 SCOPE with something explicit in config.h. In addition:
716
717 (a) pcreposix.h still had just "extern" instead of either of these macros;
718 I have replaced it with PCRE_DATA_SCOPE.
719
720 (b) Functions such as _pcre_xclass(), which are internal to the library,
721 but external in the C sense, all had PCRE_EXPORT in their definitions.
722 This is apparently wrong for the Windows case, so I have removed it.
723 (It makes no difference on Unix-like systems.)
724
725 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
726 of recursive calls to match(). This is different to MATCH_LIMIT because
727 that limits the total number of calls to match(), not all of which increase
728 the depth of recursion. Limiting the recursion depth limits the amount of
729 stack (or heap if NO_RECURSE is set) that is used. The default can be set
730 when PCRE is compiled, and changed at run time. A patch from Google adds
731 this functionality to the C++ interface.
732
733 18. Changes to the handling of Unicode character properties:
734
735 (a) Updated the table to Unicode 4.1.0.
736
737 (b) Recognize characters that are not in the table as "Cn" (undefined).
738
739 (c) I revised the way the table is implemented to a much improved format
740 which includes recognition of ranges. It now supports the ranges that
741 are defined in UnicodeData.txt, and it also amalgamates other
742 characters into ranges. This has reduced the number of entries in the
743 table from around 16,000 to around 3,000, thus reducing its size
744 considerably. I realized I did not need to use a tree structure after
745 all - a binary chop search is just as efficient. Having reduced the
746 number of entries, I extended their size from 6 bytes to 8 bytes to
747 allow for more data.
748
749 (d) Added support for Unicode script names via properties such as \p{Han}.
750
751 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
752 matching that character.
753
754 20. When matching a repeated Unicode property with a minimum greater than zero,
755 (for example \pL{2,}), PCRE could look past the end of the subject if it
756 reached it while seeking the minimum number of characters. This could
757 happen only if some of the characters were more than one byte long, because
758 there is a check for at least the minimum number of bytes.
759
760 21. Refactored the implementation of \p and \P so as to be more general, to
761 allow for more different types of property in future. This has changed the
762 compiled form incompatibly. Anybody with saved compiled patterns that use
763 \p or \P will have to recompile them.
764
765 22. Added "Any" and "L&" to the supported property types.
766
767 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
768 but give a compile time error if the value is greater than 0xff.
769
770 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
771 accidentally not being installed or uninstalled.
772
773 25. The pcre.h file was built from pcre.h.in, but the only changes that were
774 made were to insert the current release number. This seemed silly, because
775 it made things harder for people building PCRE on systems that don't run
776 "configure". I have turned pcre.h into a distributed file, no longer built
777 by "configure", with the version identification directly included. There is
778 no longer a pcre.h.in file.
779
780 However, this change necessitated a change to the pcre-config script as
781 well. It is built from pcre-config.in, and one of the substitutions was the
782 release number. I have updated configure.ac so that ./configure now finds
783 the release number by grepping pcre.h.
784
785 26. Added the ability to run the tests under valgrind.
786
787
788 Version 6.4 05-Sep-05
789 ---------------------
790
791 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
792 "--" to be printed when multiple files were scanned, even when none of the
793 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
794 consider it to be a bug, and have restored the previous behaviour.
795
796 2. A couple of code tidies to get rid of compiler warnings.
797
798 3. The pcretest program used to cheat by referring to symbols in the library
799 whose names begin with _pcre_. These are internal symbols that are not
800 really supposed to be visible externally, and in some environments it is
801 possible to suppress them. The cheating is now confined to including
802 certain files from the library's source, which is a bit cleaner.
803
804 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
805 file's purpose clearer.
806
807 5. Reorganized pcre_ucp_findchar().
808
809
810 Version 6.3 15-Aug-05
811 ---------------------
812
813 1. The file libpcre.pc.in did not have general read permission in the tarball.
814
815 2. There were some problems when building without C++ support:
816
817 (a) If C++ support was not built, "make install" and "make test" still
818 tried to test it.
819
820 (b) There were problems when the value of CXX was explicitly set. Some
821 changes have been made to try to fix these, and ...
822
823 (c) --disable-cpp can now be used to explicitly disable C++ support.
824
825 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
826 backslash in a target when C++ was disabled. This confuses some
827 versions of "make", apparently. Using an intermediate variable solves
828 this. (Same for CPP_LOBJ.)
829
830 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
831 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
832 necessary on certain architectures.
833
834 4. Added a setting of -export-symbols-regex to the link command to remove
835 those symbols that are exported in the C sense, but actually are local
836 within the library, and not documented. Their names all begin with
837 "_pcre_". This is not a perfect job, because (a) we have to except some
838 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
839 available (and never for static libraries). I have made a note to try to
840 find a way round (a) in the future.
841
842
843 Version 6.2 01-Aug-05
844 ---------------------
845
846 1. There was no test for integer overflow of quantifier values. A construction
847 such as {1111111111111111} would give undefined results. What is worse, if
848 a minimum quantifier for a parenthesized subpattern overflowed and became
849 negative, the calculation of the memory size went wrong. This could have
850 led to memory overwriting.
851
852 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
853
854 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
855 operating environments where this matters.
856
857 4. Applied Giuseppe Maxia's patch to add additional features for controlling
858 PCRE options from within the C++ wrapper.
859
860 5. Named capturing subpatterns were not being correctly counted when a pattern
861 was compiled. This caused two problems: (a) If there were more than 100
862 such subpatterns, the calculation of the memory needed for the whole
863 compiled pattern went wrong, leading to an overflow error. (b) Numerical
864 back references of the form \12, where the number was greater than 9, were
865 not recognized as back references, even though there were sufficient
866 previous subpatterns.
867
868 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
869 versions of gcc, e.g. 2.95.4.
870
871
872 Version 6.1 21-Jun-05
873 ---------------------
874
875 1. There was one reference to the variable "posix" in pcretest.c that was not
876 surrounded by "#if !defined NOPOSIX".
877
878 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
879 the cross-check on the old pcre_info() function, for the benefit of the
880 cut-down version of PCRE that is currently imported into Exim.
881
882 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
883 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
884 patterns that start (?i) but I don't think that matters. The use of (?i) is
885 just an example; this all applies to the other options as well.
886
887 4. Since libtool seems to echo the compile commands it is issuing, the output
888 from "make" can be reduced a bit by putting "@" in front of each libtool
889 compile command.
890
891 5. Patch from the folks at Google for configure.in to be a bit more thorough
892 in checking for a suitable C++ installation before trying to compile the
893 C++ stuff. This should fix a reported problem when a compiler was present,
894 but no suitable headers.
895
896 6. The man pages all had just "PCRE" as their title. I have changed them to
897 be the relevant file name. I have also arranged that these names are
898 retained in the file doc/pcre.txt, which is a concatenation in text format
899 of all the man pages except the little individual ones for each function.
900
901 7. The NON-UNIX-USE file had not been updated for the different set of source
902 files that come with release 6. I also added a few comments about the C++
903 wrapper.
904
905
906 Version 6.0 07-Jun-05
907 ---------------------
908
909 1. Some minor internal re-organization to help with my DFA experiments.
910
911 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
912 didn't matter for the library itself when fully configured, but did matter
913 when compiling without UCP support, or within Exim, where the ucp files are
914 not imported.
915
916 3. Refactoring of the library code to split up the various functions into
917 different source modules. The addition of the new DFA matching code (see
918 below) to a single monolithic source would have made it really too
919 unwieldy, quite apart from causing all the code to be include in a
920 statically linked application, when only some functions are used. This is
921 relevant even without the DFA addition now that patterns can be compiled in
922 one application and matched in another.
923
924 The downside of splitting up is that there have to be some external
925 functions and data tables that are used internally in different modules of
926 the library but which are not part of the API. These have all had their
927 names changed to start with "_pcre_" so that they are unlikely to clash
928 with other external names.
929
930 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
931 a different (DFA) algorithm. Although it is slower than the original
932 function, it does have some advantages for certain types of matching
933 problem.
934
935 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
936 including restarting after a partial match.
937
938 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
939 defined when compiling for Windows was sent to me. I have put it into the
940 code, though I have no means of testing or verifying it.
941
942 7. Added the pcre_refcount() auxiliary function.
943
944 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
945 match before or at the first newline in the subject string. In pcretest,
946 the /f option on a pattern can be used to set this.
947
948 9. A repeated \w when used in UTF-8 mode with characters greater than 256
949 would behave wrongly. This has been present in PCRE since release 4.0.
950
951 10. A number of changes to the pcregrep command:
952
953 (a) Refactored how -x works; insert ^(...)$ instead of setting
954 PCRE_ANCHORED and checking the length, in preparation for adding
955 something similar for -w.
956
957 (b) Added the -w (match as a word) option.
958
959 (c) Refactored the way lines are read and buffered so as to have more
960 than one at a time available.
961
962 (d) Implemented a pcregrep test script.
963
964 (e) Added the -M (multiline match) option. This allows patterns to match
965 over several lines of the subject. The buffering ensures that at least
966 8K, or the rest of the document (whichever is the shorter) is available
967 for matching (and similarly the previous 8K for lookbehind assertions).
968
969 (f) Changed the --help output so that it now says
970
971 -w, --word-regex(p)
972
973 instead of two lines, one with "regex" and the other with "regexp"
974 because that confused at least one person since the short forms are the
975 same. (This required a bit of code, as the output is generated
976 automatically from a table. It wasn't just a text change.)
977
978 (g) -- can be used to terminate pcregrep options if the next thing isn't an
979 option but starts with a hyphen. Could be a pattern or a path name
980 starting with a hyphen, for instance.
981
982 (h) "-" can be given as a file name to represent stdin.
983
984 (i) When file names are being printed, "(standard input)" is used for
985 the standard input, for compatibility with GNU grep. Previously
986 "<stdin>" was used.
987
988 (j) The option --label=xxx can be used to supply a name to be used for
989 stdin when file names are being printed. There is no short form.
990
991 (k) Re-factored the options decoding logic because we are going to add
992 two more options that take data. Such options can now be given in four
993 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
994
995 (l) Added the -A, -B, and -C options for requesting that lines of context
996 around matches be printed.
997
998 (m) Added the -L option to print the names of files that do not contain
999 any matching lines, that is, the complement of -l.
1000
1001 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1002 continue to scan other files.
1003
1004 (o) The -s option was incorrectly implemented. For compatibility with other
1005 greps, it now suppresses the error message for a non-existent or non-
1006 accessible file (but not the return code). There is a new option called
1007 -q that suppresses the output of matching lines, which was what -s was
1008 previously doing.
1009
1010 (p) Added --include and --exclude options to specify files for inclusion
1011 and exclusion when recursing.
1012
1013 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1014 Hopefully, it now does.
1015
1016 12. Missing cast in pcre_study().
1017
1018 13. Added an "uninstall" target to the makefile.
1019
1020 14. Replaced "extern" in the function prototypes in Makefile.in with
1021 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1022 world, but is set differently for Windows.
1023
1024 15. Added a second compiling function called pcre_compile2(). The only
1025 difference is that it has an extra argument, which is a pointer to an
1026 integer error code. When there is a compile-time failure, this is set
1027 non-zero, in addition to the error test pointer being set to point to an
1028 error message. The new argument may be NULL if no error number is required
1029 (but then you may as well call pcre_compile(), which is now just a
1030 wrapper). This facility is provided because some applications need a
1031 numeric error indication, but it has also enabled me to tidy up the way
1032 compile-time errors are handled in the POSIX wrapper.
1033
1034 16. Added VPATH=.libs to the makefile; this should help when building with one
1035 prefix path and installing with another. (Or so I'm told by someone who
1036 knows more about this stuff than I do.)
1037
1038 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1039 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1040 match everything, including newlines. This is not POSIX-compatible, but
1041 somebody wanted the feature. From pcretest it can be activated by using
1042 both the P and the s flags.
1043
1044 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1045
1046 19. libpcre.pc was being incorrectly installed as executable.
1047
1048 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1049 it now also looks for '\r' so that it will work unmodified on Windows.
1050
1051 21. Added Google's contributed C++ wrapper to the distribution.
1052
1053 22. Added some untidy missing memory free() calls in pcretest, to keep
1054 Electric Fence happy when testing.
1055
1056
1057
1058 Version 5.0 13-Sep-04
1059 ---------------------
1060
1061 1. Internal change: literal characters are no longer packed up into items
1062 containing multiple characters in a single byte-string. Each character
1063 is now matched using a separate opcode. However, there may be more than one
1064 byte in the character in UTF-8 mode.
1065
1066 2. The pcre_callout_block structure has two new fields: pattern_position and
1067 next_item_length. These contain the offset in the pattern to the next match
1068 item, and its length, respectively.
1069
1070 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1071 insertion of callouts before each pattern item. Added the /C option to
1072 pcretest to make use of this.
1073
1074 4. On the advice of a Windows user, the lines
1075
1076 #if defined(_WIN32) || defined(WIN32)
1077 _setmode( _fileno( stdout ), 0x8000 );
1078 #endif /* defined(_WIN32) || defined(WIN32) */
1079
1080 have been added to the source of pcretest. This apparently does useful
1081 magic in relation to line terminators.
1082
1083 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1084 for the benefit of those environments where the "b" makes a difference.
1085
1086 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1087 to know about it. I have put a hack into configure.in that adds in code
1088 to set GCC=yes if CC=icc. This seems to end up at a point in the
1089 generated configure script that is early enough to affect the setting of
1090 compiler options, which is what is needed, but I have no means of testing
1091 whether it really works. (The user who reported this had patched the
1092 generated configure script, which of course I cannot do.)
1093
1094 LATER: After change 22 below (new libtool files), the configure script
1095 seems to know about icc (and also ecc). Therefore, I have commented out
1096 this hack in configure.in.
1097
1098 7. Added support for pkg-config (2 patches were sent in).
1099
1100 8. Negated POSIX character classes that used a combination of internal tables
1101 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1102 [[:^ascii]]. Typically, they would match almost any characters. The other
1103 POSIX classes were not broken in this way.
1104
1105 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1106 to find the match, as PCRE was deluded into thinking that the match had to
1107 start at the start point or following a newline. The same bug applied to
1108 patterns with negative forward assertions or any backward assertions
1109 preceding ".*" at the start, unless the pattern required a fixed first
1110 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1111
1112 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1113 starting at the last subject character, bytes beyond the end of the subject
1114 string were read.
1115
1116 11. Renamed the variable "class" as "classbits" to make life easier for C++
1117 users. (Previously there was a macro definition, but it apparently wasn't
1118 enough.)
1119
1120 12. Added the new field "tables" to the extra data so that tables can be passed
1121 in at exec time, or the internal tables can be re-selected. This allows
1122 a compiled regex to be saved and re-used at a later time by a different
1123 program that might have everything at different addresses.
1124
1125 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1126 -R library as well as a -L library.
1127
1128 14. The debugging options of pcretest (-d on the command line or D on a
1129 pattern) showed incorrect output for anything following an extended class
1130 that contained multibyte characters and which was followed by a quantifier.
1131
1132 15. Added optional support for general category Unicode character properties
1133 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1134 support. It adds about 90K to the size of the library. The meanings of the
1135 inbuilt class escapes such as \d and \s have NOT been changed.
1136
1137 16. Updated pcredemo.c to include calls to free() to release the memory for the
1138 compiled pattern.
1139
1140 17. The generated file chartables.c was being created in the source directory
1141 instead of in the building directory. This caused the build to fail if the
1142 source directory was different from the building directory, and was
1143 read-only.
1144
1145 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1146 file. No doubt somebody will tell me if they don't make sense... Also added
1147 Dan Mooney's comments about building on OpenVMS.
1148
1149 19. Added support for partial matching via the PCRE_PARTIAL option for
1150 pcre_exec() and the \P data escape in pcretest.
1151
1152 20. Extended pcretest with 3 new pattern features:
1153
1154 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1155 write the compiled pattern to the file whose name is "rest-of-line".
1156 This is a straight binary dump of the data, with the saved pointer to
1157 the character tables forced to be NULL. The study data, if any, is
1158 written too. After writing, pcretest reads a new pattern.
1159
1160 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1161 compiled pattern from the given file. There must not be any
1162 occurrences of "<" in the file name (pretty unlikely); if there are,
1163 pcretest will instead treat the initial "<" as a pattern delimiter.
1164 After reading in the pattern, pcretest goes on to read data lines as
1165 usual.
1166
1167 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1168 and 16-bit fields in a compiled pattern, to simulate a pattern that
1169 was compiled on a host of opposite endianness.
1170
1171 21. The pcre-exec() function can now cope with patterns that were compiled on
1172 hosts of opposite endianness, with this restriction:
1173
1174 As for any compiled expression that is saved and used later, the tables
1175 pointer field cannot be preserved; the extra_data field in the arguments
1176 to pcre_exec() should be used to pass in a tables address if a value
1177 other than the default internal tables were used at compile time.
1178
1179 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1180 now diagnosed as an error. Previously, most of the time, a negative number
1181 would have been treated as zero, but if in addition "ovector" was passed as
1182 NULL, a crash could occur.
1183
1184 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1185 new versions from the libtool 1.5 distribution (the last one is a copy of
1186 a file called libtool.m4). This seems to have fixed the need to patch
1187 "configure" to support Darwin 1.3 (which I used to do). However, I still
1188 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1189 workstation).
1190
1191 24. Changed the PCRE licence to be the more standard "BSD" licence.
1192
1193
1194 Version 4.5 01-Dec-03
1195 ---------------------
1196
1197 1. There has been some re-arrangement of the code for the match() function so
1198 that it can be compiled in a version that does not call itself recursively.
1199 Instead, it keeps those local variables that need separate instances for
1200 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1201 needs to "recurse". Keeping track of where control must go is done by means
1202 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1203 hide most of the details from the main code, and operates only if
1204 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1205 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1206 operating.
1207
1208 To make it easier for callers to provide specially tailored get/free
1209 functions for this usage, two new functions, pcre_stack_malloc, and
1210 pcre_stack_free, are used. They are always called in strict stacking order,
1211 and the size of block requested is always the same.
1212
1213 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1214 PCRE has been compiled to use the stack or the heap for recursion. The
1215 -C option of pcretest uses this to show which version is compiled.
1216
1217 A new data escape \S, is added to pcretest; it causes the amounts of store
1218 obtained and freed by both kinds of malloc/free at match time to be added
1219 to the output.
1220
1221 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1222 what's available on my current Linux desktop machine.
1223
1224 3. When matching a UTF-8 string, the test for a valid string at the start has
1225 been extended. If start_offset is not zero, PCRE now checks that it points
1226 to a byte that is the start of a UTF-8 character. If not, it returns
1227 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1228 this is necessary because there may be backward assertions in the pattern.
1229 When matching the same subject several times, it may save resources to use
1230 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1231
1232 4. The code for checking the validity of UTF-8 strings has been tightened so
1233 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1234 containing "overlong sequences".
1235
1236 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1237 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1238 should have been "&", but it just so happened that all the cases this let
1239 through by mistake were picked up later in the function.
1240
1241 6. I had used a variable called "isblank" - this is a C99 function, causing
1242 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1243
1244 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1245 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1246 so the version is shown; (c) stop "make test" echoing "./RunTest".
1247
1248 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1249
1250 9. The prototype for memmove() for systems that don't have it was using
1251 size_t, but the inclusion of the header that defines size_t was later. I've
1252 moved the #includes for the C headers earlier to avoid this.
1253
1254 10. Added some adjustments to the code to make it easier to compiler on certain
1255 special systems:
1256
1257 (a) Some "const" qualifiers were missing.
1258 (b) Added the macro EXPORT before all exported functions; by default this
1259 is defined to be empty.
1260 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1261 that it reads its output file name as an argument instead of writing
1262 to the standard output and assuming this can be redirected.
1263
1264 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1265 class containing characters with values greater than 255, PCRE compilation
1266 went into a loop.
1267
1268 12. A recursive reference to a subpattern that was within another subpattern
1269 that had a minimum quantifier of zero caused PCRE to crash. For example,
1270 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1271 recursion. If the recursively-called subpattern itself had a zero repeat,
1272 that was OK.
1273
1274 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1275 buffer into which it was copied (for escape processing) was still set at
1276 1024, so long lines caused crashes.
1277
1278 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1279 "internal error: code overflow...". This applied to any character class
1280 that was followed by a possessive quantifier.
1281
1282 15. Modified the Makefile to add libpcre.la as a prerequisite for
1283 libpcreposix.la because I was told this is needed for a parallel build to
1284 work.
1285
1286 16. If a pattern that contained .* following optional items at the start was
1287 studied, the wrong optimizing data was generated, leading to matching
1288 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1289 matching string must start with a or b or c. The correct conclusion for
1290 this pattern is that a match can start with any character.
1291
1292
1293 Version 4.4 13-Aug-03
1294 ---------------------
1295
1296 1. In UTF-8 mode, a character class containing characters with values between
1297 127 and 255 was not handled correctly if the compiled pattern was studied.
1298 In fixing this, I have also improved the studying algorithm for such
1299 classes (slightly).
1300
1301 2. Three internal functions had redundant arguments passed to them. Removal
1302 might give a very teeny performance improvement.
1303
1304 3. Documentation bug: the value of the capture_top field in a callout is *one
1305 more than* the number of the hightest numbered captured substring.
1306
1307 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1308 in incorrectly linking with a previously installed version. They now link
1309 explicitly with libpcre.la.
1310
1311 5. configure.in no longer needs to recognize Cygwin specially.
1312
1313 6. A problem in pcre.in for Windows platforms is fixed.
1314
1315 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1316 pcretest, it used to include the size of the study block as part of its
1317 output. Unfortunately, the structure contains a field that has a different
1318 size on different hardware architectures. This meant that the tests that
1319 showed this size failed. As the block is currently always of a fixed size,
1320 this information isn't actually particularly useful in pcretest output, so
1321 I have just removed it.
1322
1323 8. Three pre-processor statements accidentally did not start in column 1.
1324 Sadly, there are *still* compilers around that complain, even though
1325 standard C has not required this for well over a decade. Sigh.
1326
1327 9. In pcretest, the code for checking callouts passed small integers in the
1328 callout_data field, which is a void * field. However, some picky compilers
1329 complained about the casts involved for this on 64-bit systems. Now
1330 pcretest passes the address of the small integer instead, which should get
1331 rid of the warnings.
1332
1333 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1334 both compile and run time, and gives an error if an invalid UTF-8 sequence
1335 is found. There is a option for disabling this check in cases where the
1336 string is known to be correct and/or the maximum performance is wanted.
1337
1338 11. In response to a bug report, I changed one line in Makefile.in from
1339
1340 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1341 to
1342 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1343
1344 to look similar to other lines, but I have no way of telling whether this
1345 is the right thing to do, as I do not use Windows. No doubt I'll get told
1346 if it's wrong...
1347
1348
1349 Version 4.3 21-May-03
1350 ---------------------
1351
1352 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1353 Makefile.
1354
1355 2. Some refactoring to improve the quality of the code:
1356
1357 (i) The utf8_table... variables are now declared "const".
1358
1359 (ii) The code for \cx, which used the "case flipping" table to upper case
1360 lower case letters, now just substracts 32. This is ASCII-specific,
1361 but the whole concept of \cx is ASCII-specific, so it seems
1362 reasonable.
1363
1364 (iii) PCRE was using its character types table to recognize decimal and
1365 hexadecimal digits in the pattern. This is silly, because it handles
1366 only 0-9, a-f, and A-F, but the character types table is locale-
1367 specific, which means strange things might happen. A private
1368 table is now used for this - though it costs 256 bytes, a table is
1369 much faster than multiple explicit tests. Of course, the standard
1370 character types table is still used for matching digits in subject
1371 strings against \d.
1372
1373 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1374 ending in _t are). So I've renamed it as ESC_tee.
1375
1376 3. The first argument for regexec() in the POSIX wrapper should have been
1377 defined as "const".
1378
1379 4. Changed pcretest to use malloc() for its buffers so that they can be
1380 Electric Fenced for debugging.
1381
1382 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1383 to read one or more bytes before the start of the subject string. Often this
1384 had no effect on PCRE's behaviour, but in some circumstances it could
1385 provoke a segmentation fault.
1386
1387 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1388 to try to read one or more bytes before the start of the subject string.
1389
1390 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1391 UTF-8 support could misbehave in various ways if the subject string
1392 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1393 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1394 back over UTF-8 characters.)
1395
1396
1397 Version 4.2 14-Apr-03
1398 ---------------------
1399
1400 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1401
1402 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1403 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1404 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1405 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1406 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1407 and BUILD_EXEEXT
1408 Note: automatic setting of the BUILD variables is not yet working
1409 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1410 compile-time but not at link-time
1411 [LINK]: use for linking executables only
1412 make different versions for Windows and non-Windows
1413 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1414 libraries
1415 [LINK_FOR_BUILD]: new variable
1416 [OBJEXT]: use throughout
1417 [EXEEXT]: use throughout
1418 <winshared>: new target
1419 <wininstall>: new target
1420 <dftables.o>: use native compiler
1421 <dftables>: use native linker
1422 <install>: handle Windows platform correctly
1423 <clean>: ditto
1424 <check>: ditto
1425 copy DLL to top builddir before testing
1426
1427 As part of these changes, -no-undefined was removed again. This was reported
1428 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1429 in any case.
1430
1431 3. Some tidies to get rid of compiler warnings:
1432
1433 . In the match_data structure, match_limit was an unsigned long int, whereas
1434 match_call_count was an int. I've made them both unsigned long ints.
1435
1436 . In pcretest the fact that a const uschar * doesn't automatically cast to
1437 a void * provoked a warning.
1438
1439 . Turning on some more compiler warnings threw up some "shadow" variables
1440 and a few more missing casts.
1441
1442 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1443 option, a class that contained a single character with a value between 128
1444 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1445
1446 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1447 option, a class that contained several characters, but with at least one
1448 whose value was between 128 and 255 caused PCRE to crash.
1449
1450
1451 Version 4.1 12-Mar-03
1452 ---------------------
1453
1454 1. Compiling with gcc -pedantic found a couple of places where casts were
1455 needed, and a string in dftables.c that was longer than standard compilers are
1456 required to support.
1457
1458 2. Compiling with Sun's compiler found a few more places where the code could
1459 be tidied up in order to avoid warnings.
1460
1461 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1462 first of these names is deprecated in the latest Autoconf in favour of the name
1463 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1464 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1465 analogy I have changed it to CFLAGS_FOR_BUILD.
1466
1467 4. Added -no-undefined to the linking command in the Makefile, because this is
1468 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1469 linking step for the pcreposix library.
1470
1471 5. PCRE was failing to diagnose the case of two named groups with the same
1472 name.
1473
1474 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1475 literal character that is needed in the subject for a match, and scans along to
1476 ensure that it is present before embarking on the full matching process. This
1477 saves time in cases of nested unlimited repeats that are never going to match.
1478 Problem: the scan can take a lot of time if the subject is very long (e.g.
1479 megabytes), thus penalizing straightforward matches. It is now done only if the
1480 amount of subject to be scanned is less than 1000 bytes.
1481
1482 7. A lesser problem with the same optimization is that it was recording the
1483 first character of an anchored pattern as "needed", thus provoking a search
1484 right along the subject, even when the first match of the pattern was going to
1485 fail. The "needed" character is now not set for anchored patterns, unless it
1486 follows something in the pattern that is of non-fixed length. Thus, it still
1487 fulfils its original purpose of finding quick non-matches in cases of nested
1488 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1489
1490
1491 Version 4.0 17-Feb-03
1492 ---------------------
1493
1494 1. If a comment in an extended regex that started immediately after a meta-item
1495 extended to the end of string, PCRE compiled incorrect data. This could lead to
1496 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1497
1498 2. Moved to autoconf 2.53 and libtool 1.4.2.
1499
1500 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1501 the special perltest8 script is no longer needed - all the tests can be run
1502 from a single perltest script.
1503
1504 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1505 by \s. It has now been removed in PCRE. This means it isn't recognized as
1506 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1507 class [:space:] *does* include VT, thereby creating a mess.
1508
1509 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1510 space and tab.
1511
1512 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1513 its new features into the main test script, reducing the number of scripts.
1514
1515 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1516 were backward compatible, and made the (?i) apply to the whole pattern, as if
1517 /i were given. Now it behaves more logically, and applies the option setting
1518 only to what follows. PCRE has been changed to follow suit. However, if it
1519 finds options settings right at the start of the pattern, it extracts them into
1520 the global options, as before. Thus, they show up in the info data.
1521
1522 8. Added support for the \Q...\E escape sequence. Characters in between are
1523 treated as literals. This is slightly different from Perl in that $ and @ are
1524 also handled as literals inside the quotes. In Perl, they will cause variable
1525 interpolation. Note the following examples:
1526
1527 Pattern PCRE matches Perl matches
1528
1529 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1530 \Qabc\$xyz\E abc\$xyz abc\$xyz
1531 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1532
1533 For compatibility with Perl, \Q...\E sequences are recognized inside character
1534 classes as well as outside them.
1535
1536 9. Re-organized 3 code statements in pcretest to avoid "overflow in
1537 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1538 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1539 signed/unsigned warnings.
1540
1541 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1542 option for pcretest, so I've replaced it by a simple function that does just
1543 that job.
1544
1545 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1546 "pcregrep -".
1547
1548 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1549 Java package. This provides some syntactic sugar for simple cases of what my
1550 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1551 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1552 item, you can use this simplified notation. Note that only makes sense with
1553 greedy quantifiers. Consequently, the use of the possessive quantifier forces
1554 greediness, whatever the setting of the PCRE_UNGREEDY option.
1555
1556 13. A change of greediness default within a pattern was not taking effect at
1557 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1558 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1559 was abstracted outside.
1560
1561 14. PCRE now supports the \G assertion. It is true when the current matching
1562 position is at the start point of the match. This differs from \A when the
1563 starting offset is non-zero. Used with the /g option of pcretest (or similar
1564 code), it works in the same way as it does for Perl's /g option. If all
1565 alternatives of a regex begin with \G, the expression is anchored to the start
1566 match position, and the "anchored" flag is set in the compiled expression.
1567
1568 15. Some bugs concerning the handling of certain option changes within patterns
1569 have been fixed. These applied to options other than (?ims). For example,
1570 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1571 been the other way round. Some of this was related to change 7 above.
1572
1573 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1574 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1575 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1576 POSIX classes only within a class (e.g. /[[:alpha:]]/).
1577
1578 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1579 mode. Unlike ".", it always matches newline, whatever the setting of
1580 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1581 assertions. Perl allows it, but it doesn't (in general) work because it can't
1582 calculate the length of the lookbehind. At least, that's the case for Perl
1583 5.8.0 - I've been told they are going to document that it doesn't work in
1584 future.
1585
1586 18. Added an error diagnosis for escapes that PCRE does not support: these are
1587 \L, \l, \N, \P, \p, \U, \u, and \X.
1588
1589 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1590 reading past the end of the pattern in cases such as /[abcd/.
1591
1592 20. PCRE was getting more memory than necessary for patterns with classes that
1593 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1594
1595 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1596 compiling PCRE for use with Virtual Pascal.
1597
1598 22. Small fix to the Makefile to make it work properly if the build is done
1599 outside the source tree.
1600
1601 23. Added a new extension: a condition to go with recursion. If a conditional
1602 subpattern starts with (?(R) the "true" branch is used if recursion has
1603 happened, whereas the "false" branch is used only at the top level.
1604
1605 24. When there was a very long string of literal characters (over 255 bytes
1606 without UTF support, over 250 bytes with UTF support), the computation of how
1607 much memory was required could be incorrect, leading to segfaults or other
1608 strange effects.
1609
1610 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1611 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1612 there was a subsequent back reference to those brackets. This meant that, for
1613 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1614 possible to check for precisely this case. All we can do is abandon the
1615 optimization if .* occurs inside capturing brackets when there are any back
1616 references whatsoever. (See below for a better fix that came later.)
1617
1618 26. The handling of the optimization for finding the first character of a
1619 non-anchored pattern, and for finding a character that is required later in the
1620 match were failing in some cases. This didn't break the matching; it just
1621 failed to optimize when it could. The way this is done has been re-implemented.
1622
1623 27. Fixed typo in error message for invalid (?R item (it said "(?p").
1624
1625 28. Added a new feature that provides some of the functionality that Perl
1626 provides with (?{...}). The facility is termed a "callout". The way it is done
1627 in PCRE is for the caller to provide an optional function, by setting
1628 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1629 global variable. By default it is unset, which disables all calling out. To get
1630 the function called, the regex must include (?C) at appropriate points. This
1631 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1632 This provides a means of identifying different callout points. When PCRE
1633 reaches such a point in the regex, if pcre_callout has been set, the external
1634 function is called. It is provided with data in a structure called
1635 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1636 matching continues; if it returns a non-zero value, the match at the current
1637 point fails. However, backtracking will occur if possible. [This was changed
1638 later and other features added - see item 49 below.]
1639
1640 29. pcretest is upgraded to test the callout functionality. It provides a
1641 callout function that displays information. By default, it shows the start of
1642 the match and the current position in the text. There are some new data escapes
1643 to vary what happens:
1644
1645 \C+ in addition, show current contents of captured substrings
1646 \C- do not supply a callout function
1647 \C!n return 1 when callout number n is reached
1648 \C!n!m return 1 when callout number n is reached for the mth time
1649
1650 30. If pcregrep was called with the -l option and just a single file name, it
1651 output "<stdin>" if a match was found, instead of the file name.
1652
1653 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1654 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1655 pcre_exec(). This saves a malloc/free per call. The default value of
1656 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1657 when configuring.
1658
1659 32. The default maximum size of a compiled pattern is 64K. There have been a
1660 few cases of people hitting this limit. The code now uses macros to handle the
1661 storing of links as offsets within the compiled pattern. It defaults to 2-byte
1662 links, but this can be changed to 3 or 4 bytes by --with-link-size when
1663 configuring. Tests 2 and 5 work only with 2-byte links because they output
1664 debugging information about compiled patterns.
1665
1666 33. Internal code re-arrangements:
1667
1668 (a) Moved the debugging function for printing out a compiled regex into
1669 its own source file (printint.c) and used #include to pull it into
1670 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1671 separate copies.
1672
1673 (b) Defined the list of op-code names for debugging as a macro in
1674 internal.h so that it is next to the definition of the opcodes.
1675
1676 (c) Defined a table of op-code lengths for simpler skipping along compiled
1677 code. This is again a macro in internal.h so that it is next to the
1678 definition of the opcodes.
1679
1680 34. Added support for recursive calls to individual subpatterns, along the
1681 lines of Robin Houston's patch (but implemented somewhat differently).
1682
1683 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1684 allow it to read and process whole directories in Win32. This code was
1685 contributed by Lionel Fourquaux; it has not been tested by me.
1686
1687 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1688 used to name a group. Names consist of alphanumerics and underscores, and must
1689 be unique. Back references use the syntax (?P=name) and recursive calls use
1690 (?P>name) which is a PCRE extension to the Python extension. Groups still have
1691 numbers. The function pcre_fullinfo() can be used after compilation to extract
1692 a name/number map. There are three relevant calls:
1693
1694 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
1695 PCRE_INFO_NAMECOUNT yields the number of entries
1696 PCRE_INFO_NAMETABLE yields a pointer to the map.
1697
1698 The map is a vector of fixed-size entries. The size of each entry depends on
1699 the length of the longest name used. The first two bytes of each entry are the
1700 group number, most significant byte first. There follows the corresponding
1701 name, zero terminated. The names are in alphabetical order.
1702
1703 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1704 case instead of 255. Making it the same both with and without UTF-8 support
1705 means that the same test output works with both.
1706
1707 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1708 calling malloc() with a zero argument.
1709
1710 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1711 optimization. I've improved things by keeping a bitmap of backreferences with
1712 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1713 fact referenced, the optimization can be applied. It is unlikely that a
1714 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1715 the match to follow \n) will appear inside brackets with a number greater than
1716 31, but if it does, any back reference > 31 suppresses the optimization.
1717
1718 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1719 of disabling numbered capturing parentheses. Any opening parenthesis that is
1720 not followed by ? behaves as if it were followed by ?: but named parentheses
1721 can still be used for capturing (and they will acquire numbers in the usual
1722 way).
1723
1724 41. Redesigned the return codes from the match() function into yes/no/error so
1725 that errors can be passed back from deep inside the nested calls. A malloc
1726 failure while inside a recursive subpattern call now causes the
1727 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
1728
1729 42. It is now possible to set a limit on the number of times the match()
1730 function is called in a call to pcre_exec(). This facility makes it possible to
1731 limit the amount of recursion and backtracking, though not in a directly
1732 obvious way, because the match() function is used in a number of different
1733 circumstances. The count starts from zero for each position in the subject
1734 string (for non-anchored patterns). The default limit is, for compatibility, a
1735 large number, namely 10 000 000. You can change this in two ways:
1736
1737 (a) When configuring PCRE before making, you can use --with-match-limit=n
1738 to set a default value for the compiled library.
1739
1740 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
1741 a different value is set. See 45 below.
1742
1743 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
1744
1745 43. Added a new function pcre_config(int, void *) to enable run-time extraction
1746 of things that can be changed at compile time. The first argument specifies
1747 what is wanted and the second points to where the information is to be placed.
1748 The current list of available information is:
1749
1750 PCRE_CONFIG_UTF8
1751
1752 The output is an integer that is set to one if UTF-8 support is available;
1753 otherwise it is set to zero.
1754
1755 PCRE_CONFIG_NEWLINE
1756
1757 The output is an integer that it set to the value of the code that is used for
1758 newline. It is either LF (10) or CR (13).
1759
1760 PCRE_CONFIG_LINK_SIZE
1761
1762 The output is an integer that contains the number of bytes used for internal
1763 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
1764
1765 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
1766
1767 The output is an integer that contains the threshold above which the POSIX
1768 interface uses malloc() for output vectors. See item 31 above.
1769
1770 PCRE_CONFIG_MATCH_LIMIT
1771
1772 The output is an unsigned integer that contains the default limit of the number
1773 of match() calls in a pcre_exec() execution. See 42 above.
1774
1775 44. pcretest has been upgraded by the addition of the -C option. This causes it
1776 to extract all the available output from the new pcre_config() function, and to
1777 output it. The program then exits immediately.
1778
1779 45. A need has arisen to pass over additional data with calls to pcre_exec() in
1780 order to support additional features. One way would have been to define
1781 pcre_exec2() (for example) with extra arguments, but this would not have been
1782 extensible, and would also have required all calls to the original function to
1783 be mapped to the new one. Instead, I have chosen to extend the mechanism that
1784 is used for passing in "extra" data from pcre_study().
1785
1786 The pcre_extra structure is now exposed and defined in pcre.h. It currently
1787 contains the following fields:
1788
1789 flags a bitmap indicating which of the following fields are set
1790 study_data opaque data from pcre_study()
1791 match_limit a way of specifying a limit on match() calls for a specific
1792 call to pcre_exec()
1793 callout_data data for callouts (see 49 below)
1794
1795 The flag bits are also defined in pcre.h, and are
1796
1797 PCRE_EXTRA_STUDY_DATA
1798 PCRE_EXTRA_MATCH_LIMIT
1799 PCRE_EXTRA_CALLOUT_DATA
1800
1801 The pcre_study() function now returns one of these new pcre_extra blocks, with
1802 the actual study data pointed to by the study_data field, and the
1803 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
1804 before. That is, this change is entirely upwards-compatible and requires no
1805 change to existing code.
1806
1807 If you want to pass in additional data to pcre_exec(), you can either place it
1808 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
1809 block.
1810
1811 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
1812 data string contains the escape sequence \M, pcretest calls pcre_exec() several
1813 times with different match limits, until it finds the minimum value needed for
1814 pcre_exec() to complete. The value is then output. This can be instructive; for
1815 most simple matches the number is quite small, but for pathological cases it
1816 gets very large very quickly.
1817
1818 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
1819 returns the size of the data block pointed to by the study_data field in a
1820 pcre_extra block, that is, the value that was passed as the argument to
1821 pcre_malloc() when PCRE was getting memory in which to place the information
1822 created by pcre_study(). The fourth argument should point to a size_t variable.
1823 pcretest has been extended so that this information is shown after a successful
1824 pcre_study() call when information about the compiled regex is being displayed.
1825
1826 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
1827 because what follows is always an absolute path. (Later: it turns out that this
1828 is more than cosmetic for MinGW, because it doesn't like empty path
1829 components.)
1830
1831 49. Some changes have been made to the callout feature (see 28 above):
1832
1833 (i) A callout function now has three choices for what it returns:
1834
1835 0 => success, carry on matching
1836 > 0 => failure at this point, but backtrack if possible
1837 < 0 => serious error, return this value from pcre_exec()
1838
1839 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
1840 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
1841 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
1842 use by callout functions. It will never be used by PCRE itself.
1843
1844 (ii) The pcre_extra structure (see 45 above) has a void * field called
1845 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
1846 pcre_callout_block structure has a field of the same name. The contents of
1847 the field passed in the pcre_extra structure are passed to the callout
1848 function in the corresponding field in the callout block. This makes it
1849 easier to use the same callout-containing regex from multiple threads. For
1850 testing, the pcretest program has a new data escape
1851
1852 \C*n pass the number n (may be negative) as callout_data
1853
1854 If the callout function in pcretest receives a non-zero value as
1855 callout_data, it returns that value.
1856
1857 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
1858 there were some redundant $(CFLAGS) in commands that are now specified as
1859 $(LINK), which already includes $(CFLAGS).
1860
1861 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
1862 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
1863 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
1864 one-byte characters throughout. Note that case-insensitive matching applies
1865 only to characters whose values are less than 256. PCRE doesn't support the
1866 notion of cases for higher-valued characters.
1867
1868 (i) A character class whose characters are all within 0-255 is handled as
1869 a bit map, and the map is inverted for negative classes. Previously, a
1870 character > 255 always failed to match such a class; however it should
1871 match if the class was a negative one (e.g. [^ab]). This has been fixed.
1872
1873 (ii) A negated character class with a single character < 255 is coded as
1874 "not this character" (OP_NOT). This wasn't working properly when the test
1875 character was multibyte, either singly or repeated.
1876
1877 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
1878 mode, for example: \x{100}{2,3}.
1879
1880 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
1881 singly or repeated) now correctly test multibyte characters. However,
1882 PCRE doesn't recognize any characters with values greater than 255 as
1883 digits, spaces, or word characters. Such characters always match \D, \S,
1884 and \W, and never match \d, \s, or \w.
1885
1886 (v) Classes may now contain characters and character ranges with values
1887 greater than 255. For example: [ab\x{100}-\x{400}].
1888
1889 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
1890 PCRE in UTF-8 mode.
1891
1892 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
1893 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
1894 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
1895 value.)
1896
1897 53. The single man page has become too large. I have therefore split it up into
1898 a number of separate man pages. These also give rise to individual HTML pages;
1899 these are now put in a separate directory, and there is an index.html page that
1900 lists them all. Some hyperlinking between the pages has been installed.
1901
1902 54. Added convenience functions for handling named capturing parentheses.
1903
1904 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
1905 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
1906 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
1907 are faulted.
1908
1909 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
1910 calling configure. These values are used when compiling the dftables.c program
1911 which is run to generate the source of the default character tables. They
1912 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
1913 you will need to set these values.
1914
1915 57. Updated the building process for Windows DLL, as provided by Fred Cox.
1916
1917
1918 Version 3.9 02-Jan-02
1919 ---------------------
1920
1921 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
1922
1923 2. If --disable-static was given, the building process failed when trying to
1924 build pcretest and pcregrep. (For some reason it was using libtool to compile
1925 them, which is not right, as they aren't part of the library.)
1926
1927
1928 Version 3.8 18-Dec-01
1929 ---------------------
1930
1931 1. The experimental UTF-8 code was completely screwed up. It was packing the
1932 bytes in the wrong order. How dumb can you get?
1933
1934
1935 Version 3.7 29-Oct-01
1936 ---------------------
1937
1938 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
1939 This caused pcretest, when used on the test data, to segfault. Unfortunately,
1940 this didn't happen under Solaris 8, where I normally test things.
1941
1942 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
1943 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
1944 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
1945 this fix an hour or so after the initial 3.7 release.)
1946
1947
1948 Version 3.6 23-Oct-01
1949 ---------------------
1950
1951 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
1952 offsets passed as NULL with zero offset count.
1953
1954 2. The config.guess and config.sub files had not been updated when I moved to
1955 the latest autoconf.
1956
1957
1958 Version 3.5 15-Aug-01
1959 ---------------------
1960
1961 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
1962 had been forgotten.
1963
1964 2. By using declared but undefined structures, we can avoid using "void"
1965 definitions in pcre.h while keeping the internal definitions of the structures
1966 private.
1967
1968 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
1969 user point of view, this means that both static and shared libraries are built
1970 by default, but this can be individually controlled. More of the work of
1971 handling this static/shared cases is now inside libtool instead of PCRE's make
1972 file.
1973
1974 4. The pcretest utility is now installed along with pcregrep because it is
1975 useful for users (to test regexs) and by doing this, it automatically gets
1976 relinked by libtool. The documentation has been turned into a man page, so
1977 there are now .1, .txt, and .html versions in /doc.
1978
1979 5. Upgrades to pcregrep:
1980 (i) Added long-form option names like gnu grep.
1981 (ii) Added --help to list all options with an explanatory phrase.
1982 (iii) Added -r, --recursive to recurse into sub-directories.
1983 (iv) Added -f, --file to read patterns from a file.
1984
1985 6. pcre_exec() was referring to its "code" argument before testing that
1986 argument for NULL (and giving an error if it was NULL).
1987
1988 7. Upgraded Makefile.in to allow for compiling in a different directory from
1989 the source directory.
1990
1991 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
1992 options bits, the pointer it was passed was to an int instead of to an unsigned
1993 long int. This mattered only on 64-bit systems.
1994
1995 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
1996 generated) instead of pcre.in, which it its source. Also made the same change
1997 in several of the .c files.
1998
1999 10. A new release of gcc defines printf() as a macro, which broke pcretest
2000 because it had an ifdef in the middle of a string argument for printf(). Fixed
2001 by using separate calls to printf().
2002
2003 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2004 script, to force use of CR or LF instead of \n in the source. On non-Unix
2005 systems, the value can be set in config.h.
2006
2007 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2008 absolute limit. Changed the text of the error message to make this clear, and
2009 likewise updated the man page.
2010
2011 13. The limit of 99 on the number of capturing subpatterns has been removed.
2012 The new limit is 65535, which I hope will not be a "real" limit.
2013
2014
2015 Version 3.4 22-Aug-00
2016 ---------------------
2017
2018 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2019
2020 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2021
2022
2023 Version 3.3 01-Aug-00
2024 ---------------------
2025
2026 1. If an octal character was given, but the value was greater than \377, it
2027 was not getting masked to the least significant bits, as documented. This could
2028 lead to crashes in some systems.
2029
2030 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2031 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2032
2033 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2034 These just pass their arguments on to (pcre_free)(), but they are provided
2035 because some uses of PCRE bind it to non-C systems that can call its functions,
2036 but cannot call free() or pcre_free() directly.
2037
2038 4. Add "make test" as a synonym for "make check". Corrected some comments in
2039 the Makefile.
2040
2041 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2042 Makefile.
2043
2044 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2045 command called pgrep for grepping around the active processes.
2046
2047 7. Added the beginnings of support for UTF-8 character strings.
2048
2049 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2050 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2051 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2052 out for the ar command.)
2053
2054
2055 Version 3.2 12-May-00
2056 ---------------------
2057
2058 This is purely a bug fixing release.
2059
2060 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2061 of ZA. This was just one example of several cases that could provoke this bug,
2062 which was introduced by change 9 of version 2.00. The code for breaking
2063 infinite loops after an iteration that matches an empty string was't working
2064 correctly.
2065
2066 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2067 when matched against abbab (for example). After matching an empty string, it
2068 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2069 caused it to match further down the string than it should.
2070
2071 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2072 was there because it doesn't seem to be needed, and it causes trouble on some
2073 systems, as it is not a Standard C header. It has been removed.
2074
2075 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2076 were reported on the Macintosh. The changes were from
2077
2078 while ((c = *(++ptr)) != 0 && c != '\n');
2079 to
2080 while ((c = *(++ptr)) != 0 && c != '\n') ;
2081
2082 Totally extraordinary, but if that's what it takes...
2083
2084 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2085 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2086 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2087 assumes the way PCRE uses memmove() (always moving upwards).
2088
2089 6. PCRE is being used in one environment where strchr() is not available. There
2090 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2091 faster code anyway.
2092
2093
2094 Version 3.1 09-Feb-00
2095 ---------------------
2096
2097 The only change in this release is the fixing of some bugs in Makefile.in for
2098 the "install" target:
2099
2100 (1) It was failing to install pcreposix.h.
2101
2102 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2103
2104
2105 Version 3.0 01-Feb-00
2106 ---------------------
2107
2108 1. Add support for the /+ modifier to perltest (to output $` like it does in
2109 pcretest).
2110
2111 2. Add support for the /g modifier to perltest.
2112
2113 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2114 matches null strings.
2115
2116 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2117 pattern. Perl treats empty patterns specially - it reuses the most recent
2118 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2119 effect.
2120
2121 5. The POSIX interface was broken in that it was just handing over the POSIX
2122 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2123 required a bigger vector, with some working space on the end. This means that
2124 the POSIX wrapper now has to get and free some memory, and copy the results.
2125
2126 6. Added some simple autoconf support, placing the test data and the
2127 documentation in separate directories, re-organizing some of the
2128 information files, and making it build pcre-config (a GNU standard). Also added
2129 libtool support for building PCRE as a shared library, which is now the
2130 default.
2131
2132 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2133 09 are not valid octal constants. Single digits will be used for minor values
2134 less than 10.
2135
2136 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2137 existing programs that set these in the POSIX interface can use PCRE without
2138 modification.
2139
2140 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2141 return all that pcre_info() returns, plus additional data. The pcre_info()
2142 function is retained for compatibility, but is considered to be obsolete.
2143
2144 10. Added experimental recursion feature (?R) to handle one common case that
2145 Perl 5.6 will be able to do with (?p{...}).
2146
2147 11. Added support for POSIX character classes like [:alpha:], which Perl is
2148 adopting.
2149
2150
2151 Version 2.08 31-Aug-99
2152 ----------------------
2153
2154 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2155 trying to match at the startoffset position, but instead was moving forward to
2156 the next newline as if a previous match had failed.
2157
2158 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2159 and could get into a loop if a null string was matched other than at the start
2160 of the subject.
2161
2162 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2163 be distinguished at compile time, and for completeness also added PCRE_DATE.
2164
2165 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2166 in GnuWin32 environments.
2167
2168
2169 Version 2.07 29-Jul-99
2170 ----------------------
2171
2172 1. The documentation is now supplied in plain text form and HTML as well as in
2173 the form of man page sources.
2174
2175 2. C++ compilers don't like assigning (void *) values to other pointer types.
2176 In particular this affects malloc(). Although there is no problem in Standard
2177 C, I've put in casts to keep C++ compilers happy.
2178
2179 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2180 should be (const char *).
2181
2182 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2183 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2184 However, I haven't made this a standard facility. The documentation doesn't
2185 mention it, and the Makefile doesn't support it.
2186
2187 5. The Makefile now contains an "install" target, with editable destinations at
2188 the top of the file. The pcretest program is not installed.
2189
2190 6. pgrep -V now gives the PCRE version number and date.
2191
2192 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2193 causing the entire string to be ignored, instead of just the last character.
2194
2195 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2196 non-matching string, it can take a very, very long time, even for strings of
2197 quite modest length, because of the nested recursion. PCRE now does better in
2198 some of these cases. It does this by remembering the last required literal
2199 character in the pattern, and pre-searching the subject to ensure it is present
2200 before running the real match. In other words, it applies a heuristic to detect
2201 some types of certain failure quickly, and in the above example, if presented
2202 with a string that has no trailing " it gives "no match" very quickly.
2203
2204 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2205 other alternatives are tried instead.
2206
2207
2208 Version 2.06 09-Jun-99
2209 ----------------------
2210
2211 1. Change pcretest's output for amount of store used to show just the code
2212 space, because the remainder (the data block) varies in size between 32-bit and
2213 64-bit systems.
2214
2215 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2216 start matching at. This allows lookbehinds to work when searching for multiple
2217 occurrences in a string.
2218
2219 3. Added additional options to pcretest for testing multiple occurrences:
2220
2221 /+ outputs the rest of the string that follows a match
2222 /g loops for multiple occurrences, using the new startoffset argument
2223 /G loops for multiple occurrences by passing an incremented pointer
2224
2225 4. PCRE wasn't doing the "first character" optimization for patterns starting
2226 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2227 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2228 the letter 'x'. On long subject strings, this gives a significant speed-up.
2229
2230
2231 Version 2.05 21-Apr-99
2232 ----------------------
2233
2234 1. Changed the type of magic_number from int to long int so that it works
2235 properly on 16-bit systems.
2236
2237 2. Fixed a bug which caused patterns starting with .* not to work correctly
2238 when the subject string contained newline characters. PCRE was assuming
2239 anchoring for such patterns in all cases, which is not correct because .* will
2240 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2241 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2242 must be retried after every newline in the subject.
2243
2244
2245 Version 2.04 18-Feb-99
2246 ----------------------
2247
2248 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2249 computation of the store needed to hold the pattern was incorrect (too large).
2250 If such patterns were nested a few deep, this could multiply and become a real
2251 problem.
2252
2253 2. Added /M option to pcretest to show the memory requirement of a specific
2254 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2255
2256 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2257 compiled in such a way that the backtracking after subsequent failure was
2258 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2259 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2260
2261
2262 Version 2.03 02-Feb-99
2263 ----------------------
2264
2265 1. Fixed typo and small mistake in man page.
2266
2267 2. Added 4th condition (GPL supersedes if conflict) and created separate
2268 LICENCE file containing the conditions.
2269
2270 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2271 Perl, that is the internal \ allows the delimiter to be included in the
2272 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2273 the final delimiter, add \ to the end of the pattern (to test the error).
2274
2275 4. Added the convenience functions for extracting substrings after a successful
2276 match. Updated pcretest to make it able to test these functions.
2277
2278
2279 Version 2.02 14-Jan-99
2280 ----------------------
2281
2282 1. Initialized the working variables associated with each extraction so that
2283 their saving and restoring doesn't refer to uninitialized store.
2284
2285 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2286 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2287 fix the problem.
2288
2289 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2290 calls, and wasn't printing the correct value for compiling calls. Increased the
2291 default value of LOOPREPEAT, and the number of significant figures in the
2292 times.
2293
2294 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2295
2296 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2297 a building problem on Windows NT with a FAT file system.
2298
2299
2300 Version 2.01 21-Oct-98
2301 ----------------------
2302
2303 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2304 to character tables built by pcre_maketables() in the current locale. If NULL
2305 is passed, the default tables are used.
2306
2307
2308 Version 2.00 24-Sep-98
2309 ----------------------
2310
2311 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2312 it any more.
2313
2314 2. Allow quantification of (?>) groups, and make it work correctly.
2315
2316 3. The first character computation wasn't working for (?>) groups.
2317
2318 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2319 end of the subject) and add 5.005's \z, which really does match only at the
2320 very end of the subject.
2321
2322 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2323
2324 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2325 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2326 localized options. All options to pcre_study() were also removed.
2327
2328 7. Add other new features from 5.005:
2329
2330 $(?<= positive lookbehind
2331 $(?<! negative lookbehind
2332 (?imsx-imsx) added the unsetting capability
2333 such a setting is global if at outer level; local otherwise
2334 (?imsx-imsx:) non-capturing groups with option setting
2335 (?(cond)re|re) conditional pattern matching
2336
2337 A backreference to itself in a repeated group matches the previous
2338 captured string.
2339
2340 8. General tidying up of studying (both automatic and via "study")
2341 consequential on the addition of new assertions.
2342
2343 9. As in 5.005, unlimited repeated groups that could match an empty substring
2344 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2345 runtime if any iteration does actually match an empty substring.
2346
2347 10. Include the RunTest script in the distribution.
2348
2349 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2350 discrepancies, some of which were old and were also with respect to 5.004. They
2351 have now been fixed.
2352
2353
2354 Version 1.09 28-Apr-98
2355 ----------------------
2356
2357 1. A negated single character class followed by a quantifier with a minimum
2358 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2359 program crashes, or just wrong answers. This did not apply to negated classes
2360 containing more than one character, or to minima other than one.
2361
2362
2363 Version 1.08 27-Mar-98
2364 ----------------------
2365
2366 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2367
2368 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2369 latter must appear before anything that relies on it in the pattern.
2370
2371
2372 Version 1.07 16-Feb-98
2373 ----------------------
2374
2375 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2376 repeat of a potentially empty string).
2377
2378
2379 Version 1.06 23-Jan-98
2380 ----------------------
2381
2382 1. Added Markus Oberhumer's little patches for C++.
2383
2384 2. Literal strings longer than 255 characters were broken.
2385
2386
2387 Version 1.05 23-Dec-97
2388 ----------------------
2389
2390 1. Negated character classes containing more than one character were failing if
2391 PCRE_CASELESS was set at run time.
2392
2393
2394 Version 1.04 19-Dec-97
2395 ----------------------
2396
2397 1. Corrected the man page, where some "const" qualifiers had been omitted.
2398
2399 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2400 input syntax.
2401
2402 3. Fixed memory leak which occurred when a regex with back references was
2403 matched with an offsets vector that wasn't big enough. The temporary memory
2404 that is used in this case wasn't being freed if the match failed.
2405
2406 4. Tidied pcretest to ensure it frees memory that it gets.
2407
2408 5. Temporary memory was being obtained in the case where the passed offsets
2409 vector was exactly big enough.
2410
2411 6. Corrected definition of offsetof() from change 5 below.
2412
2413 7. I had screwed up change 6 below and broken the rules for the use of
2414 setjmp(). Now fixed.
2415
2416
2417 Version 1.03 18-Dec-97
2418 ----------------------
2419
2420 1. A erroneous regex with a missing opening parenthesis was correctly
2421 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2422 on some systems.
2423
2424 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2425 it was reported that one broken compiler failed on the former because "code" is
2426 also an independent variable.
2427
2428 3. The erroneous regex a[]b caused an array overrun reference.
2429
2430 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2431 fail on data ending with that character. (It was going on too far, and checking
2432 the next character, typically a binary zero.) This was specific to the
2433 optimized code for single-character negative classes.
2434
2435 5. Added a contributed patch from the TIN world which does the following:
2436
2437 + Add an undef for memmove, in case the the system defines a macro for it.
2438
2439 + Add a definition of offsetof(), in case there isn't one. (I don't know
2440 the reason behind this - offsetof() is part of the ANSI standard - but
2441 it does no harm).
2442
2443 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2444 most of the places where whitespace preceded '#'. I have given up and
2445 allowed the remaining 2 cases to be at the margin.
2446
2447 + Rename some variables in pcre to eliminate shadowing. This seems very
2448 pedantic, but does no harm, of course.
2449
2450 6. Moved the call to setjmp() into its own function, to get rid of warnings
2451 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2452
2453 7. Constructs such as \d{8,} were compiling into the equivalent of
2454 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2455 outcome, but in this particular case used more store than had been allocated,
2456 which caused the bug to be discovered because it threw up an internal error.
2457
2458 8. The debugging code in both pcre and pcretest for outputting the compiled
2459 form of a regex was going wrong in the case of back references followed by
2460 curly-bracketed repeats.
2461
2462
2463 Version 1.02 12-Dec-97
2464 ----------------------
2465
2466 1. Typos in pcre.3 and comments in the source fixed.
2467
2468 2. Applied a contributed patch to get rid of places where it used to remove
2469 'const' from variables, and fixed some signed/unsigned and uninitialized
2470 variable warnings.
2471
2472 3. Added the "runtest" target to Makefile.
2473
2474 4. Set default compiler flag to -O2 rather than just -O.
2475
2476
2477 Version 1.01 19-Nov-97
2478 ----------------------
2479
2480 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2481 like /([ab]*)*/, that is, for classes with more than one character in them.
2482
2483 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2484 as /((?>a*))*/ (a PCRE_EXTRA facility).
2485
2486
2487 Version 1.00 18-Nov-97
2488 ----------------------
2489
2490 1. Added compile-time macros to support systems such as SunOS4 which don't have
2491 memmove() or strerror() but have other things that can be used instead.
2492
2493 2. Arranged that "make clean" removes the executables.
2494
2495
2496 Version 0.99 27-Oct-97
2497 ----------------------
2498
2499 1. Fixed bug in code for optimizing classes with only one character. It was
2500 initializing a 32-byte map regardless, which could cause it to run off the end
2501 of the memory it had got.
2502
2503 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2504
2505
2506 Version 0.98 22-Oct-97
2507 ----------------------
2508
2509 1. Fixed bug in code for handling temporary memory usage when there are more
2510 back references than supplied space in the ovector. This could cause segfaults.
2511
2512
2513 Version 0.97 21-Oct-97
2514 ----------------------
2515
2516 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2517
2518 2. Optimized negated single characters not to use a bit map.
2519
2520 3. Brought error texts together as macro definitions; clarified some of them;
2521 fixed one that was wrong - it said "range out of order" when it meant "invalid
2522 escape sequence".
2523
2524 4. Changed some char * arguments to const char *.
2525
2526 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2527
2528 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2529 pcretest.
2530
2531
2532 Version 0.96 16-Oct-97
2533 ----------------------
2534
2535 1. Added a simple "pgrep" utility to the distribution.
2536
2537 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2538 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2539 where "ddd" means "one or more decimal digits".
2540
2541 3. Fixed serious bug. If a pattern had a back reference, but the call to
2542 pcre_exec() didn't supply a large enough ovector to record the related
2543 identifying subpattern, the match always failed. PCRE now remembers the number
2544 of the largest back reference, and gets some temporary memory in which to save
2545 the offsets during matching if necessary, in order to ensure that
2546 backreferences always work.
2547
2548 4. Increased the compatibility with Perl in a number of ways:
2549
2550 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2551 to request this handling. The option can be set at compile or exec time.
2552
2553 (b) $ matches before a terminating newline by default; an option
2554 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2555 mode). The option can be set at compile or exec time.
2556
2557 (c) The handling of \ followed by a digit other than 0 is now supposed to be
2558 the same as Perl's. If the decimal number it represents is less than 10
2559 or there aren't that many previous left capturing parentheses, an octal
2560 escape is read. Inside a character class, it's always an octal escape,
2561 even if it is a single digit.
2562
2563 (d) An escaped but undefined alphabetic character is taken as a literal,
2564 unless PCRE_EXTRA is set. Currently this just reserves the remaining
2565 escapes.
2566
2567 (e) {0} is now permitted. (The previous item is removed from the compiled
2568 pattern).
2569
2570 5. Changed all the names of code files so that the basic parts are no longer
2571 than 10 characters, and abolished the teeny "globals.c" file.
2572
2573 6. Changed the handling of character classes; they are now done with a 32-byte
2574 bit map always.
2575
2576 7. Added the -d and /D options to pcretest to make it possible to look at the
2577 internals of compilation without having to recompile pcre.
2578
2579
2580 Version 0.95 23-Sep-97
2581 ----------------------
2582
2583 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
2584 \x20 at the start of a run of normal characters. These were being treated as
2585 real characters, instead of the source characters being re-checked.
2586
2587
2588 Version 0.94 18-Sep-97
2589 ----------------------
2590
2591 1. The functions are now thread-safe, with the caveat that the global variables
2592 containing pointers to malloc() and free() or alternative functions are the
2593 same for all threads.
2594
2595 2. Get pcre_study() to generate a bitmap of initial characters for non-
2596 anchored patterns when this is possible, and use it if passed to pcre_exec().
2597
2598
2599 Version 0.93 15-Sep-97
2600 ----------------------
2601
2602 1. /(b)|(:+)/ was computing an incorrect first character.
2603
2604 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
2605 but not actually doing anything yet.
2606
2607 3. Treat "-" characters in classes that cannot be part of ranges as literals,
2608 as Perl does (e.g. [-az] or [az-]).
2609
2610 4. Set the anchored flag if a branch starts with .* or .*? because that tests
2611 all possible positions.
2612
2613 5. Split up into different modules to avoid including unneeded functions in a
2614 compiled binary. However, compile and exec are still in one module. The "study"
2615 function is split off.
2616
2617 6. The character tables are now in a separate module whose source is generated
2618 by an auxiliary program - but can then be edited by hand if required. There are
2619 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
2620 toupper() in the code.
2621
2622 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
2623 make them global. Abolish the function for setting them, as the caller can now
2624 set them directly.
2625
2626
2627 Version 0.92 11-Sep-97
2628 ----------------------
2629
2630 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
2631 (e.g. /a{1,3}/) was broken (I mis-optimized it).
2632
2633 2. Caseless matching was not working in character classes if the characters in
2634 the pattern were in upper case.
2635
2636 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
2637
2638 4. Make PCRE_ANCHORED public and accept as a compile option.
2639
2640 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
2641 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
2642 pass them.
2643
2644 6. Give an error if bad option bits passed at compile or run time.
2645
2646 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
2647 pcretest to cause it to pass that flag.
2648
2649 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
2650 options, and the first character, if set.
2651
2652 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
2653
2654
2655 Version 0.91 10-Sep-97
2656 ----------------------
2657
2658 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
2659 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
2660
2661 2. PCRE was looping on encountering an indefinitely repeated back reference to
2662 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
2663 Perl does - treats the match as successful.
2664
2665 ****

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