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Revision 226 - (show annotations) (download)
Tue Aug 21 11:46:08 2007 UTC (7 years, 1 month ago) by ph10
File size: 138505 byte(s)
Don't advance by 2 if explicit \r or \n in the pattern. Add 
PCRE_INFO_HASCRORLF.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.3 20-Aug-07
5 ---------------------
6
7 1. In the rejigging of the build system that eventually resulted in 7.1, the
8 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
9 brackets there is not right, since it causes compilers to look for an
10 installed pcre.h, not the version that is in the source that is being
11 compiled (which of course may be different). I have changed it back to:
12
13 #include "pcre.h"
14
15 I have a vague recollection that the change was concerned with compiling in
16 different directories, but in the new build system, that is taken care of
17 by the VPATH setting the Makefile.
18
19 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
20 when the subject happened to end in the byte 0x85 (e.g. if the last
21 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
22 characters but of course it shouldn't be taken as a newline when it is part
23 of another character. The bug was that, for an unlimited repeat of . in
24 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
25 characters when looking for a newline.
26
27 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
28
29 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
30 in debug output.
31
32 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
33 long printing in the pcrecpp unittest when running under MinGW.
34
35 6. ESC_K was left out of the EBCDIC table.
36
37 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
38 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
39 limit also applies to "virtual nesting" when a pattern is recursive, and in
40 this case 1000 isn't so big. I have been able to remove this limit at the
41 expense of backing off one optimization in certain circumstances. Normally,
42 when pcre_exec() would call its internal match() function recursively and
43 immediately return the result unconditionally, it uses a "tail recursion"
44 feature to save stack. However, when a subpattern that can match an empty
45 string has an unlimited repetition quantifier, it no longer makes this
46 optimization. That gives it a stack frame in which to save the data for
47 checking that an empty string has been matched. Previously this was taken
48 from the 1000-entry workspace that had been reserved. So now there is no
49 explicit limit, but more stack is used.
50
51 8. Applied Daniel's patches to solve problems with the import/export magic
52 syntax that is required for Windows, and which was going wrong for the
53 pcreposix and pcrecpp parts of the library. These were overlooked when this
54 problem was solved for the main library.
55
56 9. There were some crude static tests to avoid integer overflow when computing
57 the size of patterns that contain repeated groups with explicit upper
58 limits. As the maximum quantifier is 65535, the maximum group length was
59 set at 30,000 so that the product of these two numbers did not overflow a
60 32-bit integer. However, it turns out that people want to use groups that
61 are longer than 30,000 bytes (though not repeat them that many times).
62 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
63 made it possible to implement the integer overflow checks in a much more
64 dynamic way, which I have now done. The artificial limitation on group
65 length has been removed - we now have only the limit on the total length of
66 the compiled pattern, which depends on the LINK_SIZE setting.
67
68 10. Fixed a bug in the documentation for get/copy named substring when
69 duplicate names are permitted. If none of the named substrings are set, the
70 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
71 empty string.
72
73 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
74 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
75 because the ] is interpreted as the first data character and the
76 terminating ] is not found. PCRE has been made compatible with Perl in this
77 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
78 cause memory overwriting.
79
80 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
81 string has been matched (to stop an infinite loop). It was not recognizing
82 a conditional subpattern that could match an empty string if that
83 subpattern was within another subpattern. For example, it looped when
84 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
85 condition was not nested. This bug has been fixed.
86
87 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
88 past the start of the subject in the presence of bytes with the top bit
89 set, for example "\x8aBCD".
90
91 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
92 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
93
94 14. Optimized (?!) to (*FAIL).
95
96 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
97 This restricts code points to be within the range 0 to 0x10FFFF, excluding
98 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
99 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
100 does: it's just the validity check that is more restrictive.
101
102 16. Inserted checks for integer overflows during escape sequence (backslash)
103 processing, and also fixed erroneous offset values for syntax errors during
104 backslash processing.
105
106 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
107 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
108
109 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
110 caused an overrun.
111
112 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
113 something other than just ASCII characters) inside a group that had an
114 unlimited repeat caused a loop at compile time (while checking to see
115 whether the group could match an empty string).
116
117 20. Debugging a pattern containing \p or \P could cause a crash. For example,
118 [\P{Any}] did so. (Error in the code for printing property names.)
119
120 21. An orphan \E inside a character class could cause a crash.
121
122 22. A repeated capturing bracket such as (A)? could cause a wild memory
123 reference during compilation.
124
125 23. There are several functions in pcre_compile() that scan along a compiled
126 expression for various reasons (e.g. to see if it's fixed length for look
127 behind). There were bugs in these functions when a repeated \p or \P was
128 present in the pattern. These operators have additional parameters compared
129 with \d, etc, and these were not being taken into account when moving along
130 the compiled data. Specifically:
131
132 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
133 length.
134
135 (b) An item such as \pL+ within a repeated group could cause crashes or
136 loops.
137
138 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
139 "reference to non-existent subpattern" error.
140
141 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
142
143 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
144 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
145
146 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
147
148 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
149 character were causing crashes (broken optimization).
150
151 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
152 \p or \P) caused a compile-time loop.
153
154 28. More problems have arisen in unanchored patterns when CRLF is a valid line
155 break. For example, the unstudied pattern [\r\n]A does not match the string
156 "\r\nA" because change 7.0/46 below moves the current point on by two
157 characters after failing to match at the start. However, the pattern \nA
158 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
159 the same is true. There doesn't seem any very clean way out of this, but
160 what I have chosen to do makes the common cases work: PCRE now takes note
161 of whether there can be an explicit match for \r or \n anywhere in the
162 pattern, and if so, 7.0/46 no longer applies. As part of this change,
163 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
164 pattern has explicit CR or LF references.
165
166
167 Version 7.2 19-Jun-07
168 ---------------------
169
170 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
171 which is apparently normally available under Windows.
172
173 2. Re-jig the pcregrep tests with different newline settings in an attempt
174 to make them independent of the local environment's newline setting.
175
176 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
177
178 4. Some of the "internals" tests were previously cut out when the link size
179 was not 2, because the output contained actual offsets. The recent new
180 "Z" feature of pcretest means that these can be cut out, making the tests
181 usable with all link sizes.
182
183 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
184 stack recursion. This gives a massive performance boost under BSD, but just
185 a small improvement under Linux. However, it saves one field in the frame
186 in all cases.
187
188 6. Added more features from the forthcoming Perl 5.10:
189
190 (a) (?-n) (where n is a string of digits) is a relative subroutine or
191 recursion call. It refers to the nth most recently opened parentheses.
192
193 (b) (?+n) is also a relative subroutine call; it refers to the nth next
194 to be opened parentheses.
195
196 (c) Conditions that refer to capturing parentheses can be specified
197 relatively, for example, (?(-2)... or (?(+3)...
198
199 (d) \K resets the start of the current match so that everything before
200 is not part of it.
201
202 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
203
204 (f) \g{name} is another synonym - part of Perl 5.10's unification of
205 reference syntax.
206
207 (g) (?| introduces a group in which the numbering of parentheses in each
208 alternative starts with the same number.
209
210 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
211
212 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
213 PCRE_INFO_JCHANGED.
214
215 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
216 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
217 for detecting groups that can match an empty string.
218
219 9. A pattern with a very large number of alternatives (more than several
220 hundred) was running out of internal workspace during the pre-compile
221 phase, where pcre_compile() figures out how much memory will be needed. A
222 bit of new cunning has reduced the workspace needed for groups with
223 alternatives. The 1000-alternative test pattern now uses 12 bytes of
224 workspace instead of running out of the 4096 that are available.
225
226 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
227
228 11. Applied patch from Google to remove an optimization that didn't quite work.
229 The report of the bug said:
230
231 pcrecpp::RE("a*").FullMatch("aaa") matches, while
232 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
233 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
234
235 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
236 it matched the wrong number of bytes.
237
238
239 Version 7.1 24-Apr-07
240 ---------------------
241
242 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
243 that is more "standard", making use of automake and other Autotools. There
244 is some re-arrangement of the files and adjustment of comments consequent
245 on this.
246
247 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
248 for recursive directory scanning broke on some systems because the files
249 are not scanned in any specific order and on different systems the order
250 was different. A call to "sort" has been inserted into RunGrepTest for the
251 approprate test as a short-term fix. In the longer term there may be an
252 alternative.
253
254 3. I had an email from Eric Raymond about problems translating some of PCRE's
255 man pages to HTML (despite the fact that I distribute HTML pages, some
256 people do their own conversions for various reasons). The problems
257 concerned the use of low-level troff macros .br and .in. I have therefore
258 removed all such uses from the man pages (some were redundant, some could
259 be replaced by .nf/.fi pairs). The 132html script that I use to generate
260 HTML has been updated to handle .nf/.fi and to complain if it encounters
261 .br or .in.
262
263 4. Updated comments in configure.ac that get placed in config.h.in and also
264 arranged for config.h to be included in the distribution, with the name
265 config.h.generic, for the benefit of those who have to compile without
266 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
267
268 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
269 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
270 makevp.bat for the current PCRE, using the additional files
271 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
272
273 6. A Windows user reported a minor discrepancy with test 2, which turned out
274 to be caused by a trailing space on an input line that had got lost in his
275 copy. The trailing space was an accident, so I've just removed it.
276
277 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
278 that is needed.
279
280 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
281 as "const" (a) because they are and (b) because it helps the PHP
282 maintainers who have recently made a script to detect big data structures
283 in the php code that should be moved to the .rodata section. I remembered
284 to update Builducptable as well, so it won't revert if ucptable.h is ever
285 re-created.
286
287 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
288 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
289 order to be able to cut out the UTF-8 tables in the latter when UTF-8
290 support is not required. This saves 1.5-2K of code, which is important in
291 some applications.
292
293 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
294 so as not to refer to the tables, even though these functions will never be
295 called when UTF-8 support is disabled. Otherwise there are problems with a
296 shared library.
297
298 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
299
300 (a) It was defining its arguments as char * instead of void *.
301
302 (b) It was assuming that all moves were upwards in memory; this was true
303 a long time ago when I wrote it, but is no longer the case.
304
305 The emulated memove() is provided for those environments that have neither
306 memmove() nor bcopy(). I didn't think anyone used it these days, but that
307 is clearly not the case, as these two bugs were recently reported.
308
309 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
310 and Detrail to create the HTML documentation, the .txt form of the man
311 pages, and it removes trailing spaces from listed files. It also creates
312 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
313 case, it wraps all the #defines with #ifndefs. This script should be run
314 before "make dist".
315
316 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
317 with Unicode property support.
318
319 (a) For a maximizing quantifier, if the two different cases of the
320 character were of different lengths in their UTF-8 codings (there are
321 some cases like this - I found 11), and the matching function had to
322 back up over a mixture of the two cases, it incorrectly assumed they
323 were both the same length.
324
325 (b) When PCRE was configured to use the heap rather than the stack for
326 recursion during matching, it was not correctly preserving the data for
327 the other case of a UTF-8 character when checking ahead for a match
328 while processing a minimizing repeat. If the check also involved
329 matching a wide character, but failed, corruption could cause an
330 erroneous result when trying to check for a repeat of the original
331 character.
332
333 13. Some tidying changes to the testing mechanism:
334
335 (a) The RunTest script now detects the internal link size and whether there
336 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
337 values substituted by "configure". (The RunGrepTest script already did
338 this for UTF-8.) The configure.ac script no longer substitutes the
339 relevant variables.
340
341 (b) The debugging options /B and /D in pcretest show the compiled bytecode
342 with length and offset values. This means that the output is different
343 for different internal link sizes. Test 2 is skipped for link sizes
344 other than 2 because of this, bypassing the problem. Unfortunately,
345 there was also a test in test 3 (the locale tests) that used /B and
346 failed for link sizes other than 2. Rather than cut the whole test out,
347 I have added a new /Z option to pcretest that replaces the length and
348 offset values with spaces. This is now used to make test 3 independent
349 of link size. (Test 2 will be tidied up later.)
350
351 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
352 segmentation fault instead of returning the appropriate error message.
353
354 15. In multiline mode when the newline sequence was set to "any", the pattern
355 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
356 This doesn't seem right; it now treats the CRLF combination as the line
357 ending, and so does not match in that case. It's only a pattern such as ^$
358 that would hit this one: something like ^ABC$ would have failed after \r
359 and then tried again after \r\n.
360
361 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
362 in an attempt to make files that differ only in their line terminators
363 compare equal. This works on Linux.
364
365 17. Under certain error circumstances pcregrep might try to free random memory
366 as it exited. This is now fixed, thanks to valgrind.
367
368 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
369 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
370 was because its rules for how to advance for /g after matching an empty
371 string at the end of a line did not allow for this case. They now check for
372 it specially.
373
374 20. pcretest is supposed to handle patterns and data of any length, by
375 extending its buffers when necessary. It was getting this wrong when the
376 buffer for a data line had to be extended.
377
378 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
379 CRLF as a newline sequence.
380
381 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
382 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
383 I have nevertheless tidied it up.
384
385 23. Added some casts to kill warnings from HP-UX ia64 compiler.
386
387 24. Added a man page for pcre-config.
388
389
390 Version 7.0 19-Dec-06
391 ---------------------
392
393 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
394 moving to gcc 4.1.1.
395
396 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
397 sys/time.h, which is documented as needed for this function. It doesn't
398 seem to matter on Linux, but it showed up on some releases of OS X.
399
400 3. It seems that there are systems where bytes whose values are greater than
401 127 match isprint() in the "C" locale. The "C" locale should be the
402 default when a C program starts up. In most systems, only ASCII printing
403 characters match isprint(). This difference caused the output from pcretest
404 to vary, making some of the tests fail. I have changed pcretest so that:
405
406 (a) When it is outputting text in the compiled version of a pattern, bytes
407 other than 32-126 are always shown as hex escapes.
408
409 (b) When it is outputting text that is a matched part of a subject string,
410 it does the same, unless a different locale has been set for the match
411 (using the /L modifier). In this case, it uses isprint() to decide.
412
413 4. Fixed a major bug that caused incorrect computation of the amount of memory
414 required for a compiled pattern when options that changed within the
415 pattern affected the logic of the preliminary scan that determines the
416 length. The relevant options are -x, and -i in UTF-8 mode. The result was
417 that the computed length was too small. The symptoms of this bug were
418 either the PCRE error "internal error: code overflow" from pcre_compile(),
419 or a glibc crash with a message such as "pcretest: free(): invalid next
420 size (fast)". Examples of patterns that provoked this bug (shown in
421 pcretest format) are:
422
423 /(?-x: )/x
424 /(?x)(?-x: \s*#\s*)/
425 /((?i)[\x{c0}])/8
426 /(?i:[\x{c0}])/8
427
428 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
429 is now done differently.
430
431 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
432 wrapper classes; (b) implement a new function in the C++ scanner that is
433 more efficient than the old way of doing things because it avoids levels of
434 recursion in the regex matching; (c) add a paragraph to the documentation
435 for the FullMatch() function.
436
437 6. The escape sequence \n was being treated as whatever was defined as
438 "newline". Not only was this contrary to the documentation, which states
439 that \n is character 10 (hex 0A), but it also went horribly wrong when
440 "newline" was defined as CRLF. This has been fixed.
441
442 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
443 was being set to -1 for the "end of line" case (supposedly a value that no
444 character can have). Though this value is never used (the check for end of
445 line is "zero bytes in current character"), it caused compiler complaints.
446 I've changed it to 0xffffffff.
447
448 8. In pcre_version.c, the version string was being built by a sequence of
449 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
450 string (as it is for production releases) called a macro with an empty
451 argument. The C standard says the result of this is undefined. The gcc
452 compiler treats it as an empty string (which was what was wanted) but it is
453 reported that Visual C gives an error. The source has been hacked around to
454 avoid this problem.
455
456 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
457 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
458 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
459 of them did).
460
461 10. Originally, pcretest opened its input and output without "b"; then I was
462 told that "b" was needed in some environments, so it was added for release
463 5.0 to both the input and output. (It makes no difference on Unix-like
464 systems.) Later I was told that it is wrong for the input on Windows. I've
465 now abstracted the modes into two macros, to make it easier to fiddle with
466 them, and removed "b" from the input mode under Windows.
467
468 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
469
470 12. Added -help and --help to pcretest as an official way of being reminded
471 of the options.
472
473 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
474 and pcrecpp.cc because they annoy compilers at high warning levels.
475
476 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
477
478 15. Fixed an occurrence of == in configure.ac that should have been = (shell
479 scripts are not C programs :-) and which was not noticed because it works
480 on Linux.
481
482 16. pcretest is supposed to handle any length of pattern and data line (as one
483 line or as a continued sequence of lines) by extending its input buffer if
484 necessary. This feature was broken for very long pattern lines, leading to
485 a string of junk being passed to pcre_compile() if the pattern was longer
486 than about 50K.
487
488 17. I have done a major re-factoring of the way pcre_compile() computes the
489 amount of memory needed for a compiled pattern. Previously, there was code
490 that made a preliminary scan of the pattern in order to do this. That was
491 OK when PCRE was new, but as the facilities have expanded, it has become
492 harder and harder to keep it in step with the real compile phase, and there
493 have been a number of bugs (see for example, 4 above). I have now found a
494 cunning way of running the real compile function in a "fake" mode that
495 enables it to compute how much memory it would need, while actually only
496 ever using a few hundred bytes of working memory and without too many
497 tests of the mode. This should make future maintenance and development
498 easier. A side effect of this work is that the limit of 200 on the nesting
499 depth of parentheses has been removed (though this was never a serious
500 limitation, I suspect). However, there is a downside: pcre_compile() now
501 runs more slowly than before (30% or more, depending on the pattern). I
502 hope this isn't a big issue. There is no effect on runtime performance.
503
504 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
505 newline (only possible for the last line of a file) and it was a
506 pattern that set a locale (followed by /Lsomething), pcretest crashed.
507
508 19. Added additional timing features to pcretest. (1) The -tm option now times
509 matching only, not compiling. (2) Both -t and -tm can be followed, as a
510 separate command line item, by a number that specifies the number of
511 repeats to use when timing. The default is 50000; this gives better
512 precision, but takes uncomfortably long for very large patterns.
513
514 20. Extended pcre_study() to be more clever in cases where a branch of a
515 subpattern has no definite first character. For example, (a*|b*)[cd] would
516 previously give no result from pcre_study(). Now it recognizes that the
517 first character must be a, b, c, or d.
518
519 21. There was an incorrect error "recursive call could loop indefinitely" if
520 a subpattern (or the entire pattern) that was being tested for matching an
521 empty string contained only one non-empty item after a nested subpattern.
522 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
523 incorrectly, because the \d was being skipped in the check.
524
525 22. The pcretest program now has a new pattern option /B and a command line
526 option -b, which is equivalent to adding /B to every pattern. This causes
527 it to show the compiled bytecode, without the additional information that
528 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
529 is the same as /B/I).
530
531 23. A new optimization is now able automatically to treat some sequences such
532 as a*b as a*+b. More specifically, if something simple (such as a character
533 or a simple class like \d) has an unlimited quantifier, and is followed by
534 something that cannot possibly match the quantified thing, the quantifier
535 is automatically "possessified".
536
537 24. A recursive reference to a subpattern whose number was greater than 39
538 went wrong under certain circumstances in UTF-8 mode. This bug could also
539 have affected the operation of pcre_study().
540
541 25. Realized that a little bit of performance could be had by replacing
542 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
543
544 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
545
546 27. Possessive quantifiers such as a++ were previously implemented by turning
547 them into atomic groups such as ($>a+). Now they have their own opcodes,
548 which improves performance. This includes the automatically created ones
549 from 23 above.
550
551 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
552 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
553 the first matched character to be a colon. This applied both to named and
554 numbered groups.
555
556 29. The ucpinternal.h header file was missing its idempotency #ifdef.
557
558 30. I was sent a "project" file called libpcre.a.dev which I understand makes
559 building PCRE on Windows easier, so I have included it in the distribution.
560
561 31. There is now a check in pcretest against a ridiculously large number being
562 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
563 loop, the loop is abandoned.
564
565 32. Forward references to subpatterns in conditions such as (?(2)...) where
566 subpattern 2 is defined later cause pcre_compile() to search forwards in
567 the pattern for the relevant set of parentheses. This search went wrong
568 when there were unescaped parentheses in a character class, parentheses
569 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
570
571 33. "Subroutine" calls and backreferences were previously restricted to
572 referencing subpatterns earlier in the regex. This restriction has now
573 been removed.
574
575 34. Added a number of extra features that are going to be in Perl 5.10. On the
576 whole, these are just syntactic alternatives for features that PCRE had
577 previously implemented using the Python syntax or my own invention. The
578 other formats are all retained for compatibility.
579
580 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
581 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
582 also .NET compatible.
583
584 (b) A recursion or subroutine call to a named group can now be defined as
585 (?&name) as well as (?P>name).
586
587 (c) A backreference to a named group can now be defined as \k<name> or
588 \k'name' as well as (?P=name). The new forms, as well as being in Perl
589 5.10, are also .NET compatible.
590
591 (d) A conditional reference to a named group can now use the syntax
592 (?(<name>) or (?('name') as well as (?(name).
593
594 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
595 groups (named and numbered) that are never evaluated inline, but can be
596 called as "subroutines" from elsewhere. In effect, the DEFINE condition
597 is always false. There may be only one alternative in such a group.
598
599 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
600 as the simple (?(R). The condition is true only if the most recent
601 recursion is that of the given number or name. It does not search out
602 through the entire recursion stack.
603
604 (g) The escape \gN or \g{N} has been added, where N is a positive or
605 negative number, specifying an absolute or relative reference.
606
607 35. Tidied to get rid of some further signed/unsigned compiler warnings and
608 some "unreachable code" warnings.
609
610 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
611 things, this adds five new scripts.
612
613 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
614 There were also incompatibilities regarding the handling of \Q..\E inside
615 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
616 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
617
618 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
619 matches an empty string, and forcibly breaks the loop. There were bugs in
620 this code in non-simple cases. For a pattern such as ^(a()*)* matched
621 against aaaa the result was just "a" rather than "aaaa", for example. Two
622 separate and independent bugs (that affected different cases) have been
623 fixed.
624
625 39. Refactored the code to abolish the use of different opcodes for small
626 capturing bracket numbers. This is a tidy that I avoided doing when I
627 removed the limit on the number of capturing brackets for 3.5 back in 2001.
628 The new approach is not only tidier, it makes it possible to reduce the
629 memory needed to fix the previous bug (38).
630
631 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
632 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
633 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
634 mode.
635
636 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
637 report.
638
639 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
640 copy construction and assignment in the C++ wrapper.
641
642 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
643 couple of bugs that could have given wrong results in the "--newline=crlf"
644 case.
645
646 44. Added a number of casts and did some reorganization of signed/unsigned int
647 variables following suggestions from Dair Grant. Also renamed the variable
648 "this" as "item" because it is a C++ keyword.
649
650 45. Arranged for dftables to add
651
652 #include "pcre_internal.h"
653
654 to pcre_chartables.c because without it, gcc 4.x may remove the array
655 definition from the final binary if PCRE is built into a static library and
656 dead code stripping is activated.
657
658 46. For an unanchored pattern, if a match attempt fails at the start of a
659 newline sequence, and the newline setting is CRLF or ANY, and the next two
660 characters are CRLF, advance by two characters instead of one.
661
662
663 Version 6.7 04-Jul-06
664 ---------------------
665
666 1. In order to handle tests when input lines are enormously long, pcretest has
667 been re-factored so that it automatically extends its buffers when
668 necessary. The code is crude, but this _is_ just a test program. The
669 default size has been increased from 32K to 50K.
670
671 2. The code in pcre_study() was using the value of the re argument before
672 testing it for NULL. (Of course, in any sensible call of the function, it
673 won't be NULL.)
674
675 3. The memmove() emulation function in pcre_internal.h, which is used on
676 systems that lack both memmove() and bcopy() - that is, hardly ever -
677 was missing a "static" storage class specifier.
678
679 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
680 containing an extended class (one that cannot be represented by a bitmap
681 because it contains high-valued characters or Unicode property items, e.g.
682 [\pZ]). Almost always one would set UTF-8 mode when processing such a
683 pattern, but PCRE should not loop if you do not (it no longer does).
684 [Detail: two cases were found: (a) a repeated subpattern containing an
685 extended class; (b) a recursive reference to a subpattern that followed a
686 previous extended class. It wasn't skipping over the extended class
687 correctly when UTF-8 mode was not set.]
688
689 5. A negated single-character class was not being recognized as fixed-length
690 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
691 compile error "lookbehind assertion is not fixed length".
692
693 6. The RunPerlTest auxiliary script was showing an unexpected difference
694 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
695 write a Perl script that can interpret lines of an input file either as
696 byte characters or as UTF-8, which is what "perltest" was being required to
697 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
698 can't do is switch easily at run time between having the "use utf8;" pragma
699 or not. In the end, I fudged it by using the RunPerlTest script to insert
700 "use utf8;" explicitly for the UTF-8 tests.
701
702 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
703 the end of the subject string, contrary to the documentation and to what
704 Perl does. This was true of both matching functions. Now it matches only at
705 the start of the subject and immediately after *internal* newlines.
706
707 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
708 a pointer to an int instead of a pointer to an unsigned long int. This
709 caused problems on 64-bit systems.
710
711 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
712 instance of the 'standard' template library not being so standard".
713
714 10. There was no check on the number of named subpatterns nor the maximum
715 length of a subpattern name. The product of these values is used to compute
716 the size of the memory block for a compiled pattern. By supplying a very
717 long subpattern name and a large number of named subpatterns, the size
718 computation could be caused to overflow. This is now prevented by limiting
719 the length of names to 32 characters, and the number of named subpatterns
720 to 10,000.
721
722 11. Subpatterns that are repeated with specific counts have to be replicated in
723 the compiled pattern. The size of memory for this was computed from the
724 length of the subpattern and the repeat count. The latter is limited to
725 65535, but there was no limit on the former, meaning that integer overflow
726 could in principle occur. The compiled length of a repeated subpattern is
727 now limited to 30,000 bytes in order to prevent this.
728
729 12. Added the optional facility to have named substrings with the same name.
730
731 13. Added the ability to use a named substring as a condition, using the
732 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
733 are numbers (not recommended). Forward references are permitted.
734
735 14. Added forward references in named backreferences (if you see what I mean).
736
737 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
738 pattern could run off the end of the subject. For example, the pattern
739 "(?s)(.{1,5})"8 did this with the subject "ab".
740
741 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
742 PCRE_CASELESS was set when matching characters that were quantified with ?
743 or *.
744
745 17. A character class other than a single negated character that had a minimum
746 but no maximum quantifier - for example [ab]{6,} - was not handled
747 correctly by pce_dfa_exec(). It would match only one character.
748
749 18. A valid (though odd) pattern that looked like a POSIX character
750 class but used an invalid character after [ (for example [[,abc,]]) caused
751 pcre_compile() to give the error "Failed: internal error: code overflow" or
752 in some cases to crash with a glibc free() error. This could even happen if
753 the pattern terminated after [[ but there just happened to be a sequence of
754 letters, a binary zero, and a closing ] in the memory that followed.
755
756 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
757 over the years. Originally (before any Unicode support), just the bottom 8
758 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
759 output from "man perlunicode" includes this:
760
761 The regular expression compiler produces polymorphic opcodes. That
762 is, the pattern adapts to the data and automatically switches to
763 the Unicode character scheme when presented with Unicode data--or
764 instead uses a traditional byte scheme when presented with byte
765 data.
766
767 Sadly, a wide octal escape does not cause a switch, and in a string with
768 no other multibyte characters, these octal escapes are treated as before.
769 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
770 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
771 Unicode string.
772
773 I have not perpetrated such confusion in PCRE. Up till now, it took just
774 the bottom 8 bits, as in old Perl. I have now made octal escapes with
775 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
776 translate to the appropriate multibyte character.
777
778 29. Applied some refactoring to reduce the number of warnings from Microsoft
779 and Borland compilers. This has included removing the fudge introduced
780 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
781 a warning about an unused variable.
782
783 21. PCRE has not included VT (character 0x0b) in the set of whitespace
784 characters since release 4.0, because Perl (from release 5.004) does not.
785 [Or at least, is documented not to: some releases seem to be in conflict
786 with the documentation.] However, when a pattern was studied with
787 pcre_study() and all its branches started with \s, PCRE still included VT
788 as a possible starting character. Of course, this did no harm; it just
789 caused an unnecessary match attempt.
790
791 22. Removed a now-redundant internal flag bit that recorded the fact that case
792 dependency changed within the pattern. This was once needed for "required
793 byte" processing, but is no longer used. This recovers a now-scarce options
794 bit. Also moved the least significant internal flag bit to the most-
795 significant bit of the word, which was not previously used (hangover from
796 the days when it was an int rather than a uint) to free up another bit for
797 the future.
798
799 23. Added support for CRLF line endings as well as CR and LF. As well as the
800 default being selectable at build time, it can now be changed at runtime
801 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
802 specify that it is scanning data with non-default line endings.
803
804 24. Changed the definition of CXXLINK to make it agree with the definition of
805 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
806
807 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
808 recursions. This makes a big different to stack usage for some patterns.
809
810 26. If a subpattern containing a named recursion or subroutine reference such
811 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
812 the space required for the compiled pattern went wrong and gave too small a
813 value. Depending on the environment, this could lead to "Failed: internal
814 error: code overflow at offset 49" or "glibc detected double free or
815 corruption" errors.
816
817 27. Applied patches from Google (a) to support the new newline modes and (b) to
818 advance over multibyte UTF-8 characters in GlobalReplace.
819
820 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
821 difference for some implementation of PCRE in some Windows version.
822
823 29. Added some extra testing facilities to pcretest:
824
825 \q<number> in a data line sets the "match limit" value
826 \Q<number> in a data line sets the "match recursion limt" value
827 -S <number> sets the stack size, where <number> is in megabytes
828
829 The -S option isn't available for Windows.
830
831
832 Version 6.6 06-Feb-06
833 ---------------------
834
835 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
836 in pcreposix.h. I have copied the definition from pcre.h.
837
838 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
839 because pcre.h is no longer a built file.
840
841 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
842 not normally included in the compiled code.
843
844
845 Version 6.5 01-Feb-06
846 ---------------------
847
848 1. When using the partial match feature with pcre_dfa_exec(), it was not
849 anchoring the second and subsequent partial matches at the new starting
850 point. This could lead to incorrect results. For example, with the pattern
851 /1234/, partially matching against "123" and then "a4" gave a match.
852
853 2. Changes to pcregrep:
854
855 (a) All non-match returns from pcre_exec() were being treated as failures
856 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
857 error message is output. Some extra information is given for the
858 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
859 probably the only errors that are likely to be caused by users (by
860 specifying a regex that has nested indefinite repeats, for instance).
861 If there are more than 20 of these errors, pcregrep is abandoned.
862
863 (b) A binary zero was treated as data while matching, but terminated the
864 output line if it was written out. This has been fixed: binary zeroes
865 are now no different to any other data bytes.
866
867 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
868 used to set a locale for matching. The --locale=xxxx long option has
869 been added (no short equivalent) to specify a locale explicitly on the
870 pcregrep command, overriding the environment variables.
871
872 (d) When -B was used with -n, some line numbers in the output were one less
873 than they should have been.
874
875 (e) Added the -o (--only-matching) option.
876
877 (f) If -A or -C was used with -c (count only), some lines of context were
878 accidentally printed for the final match.
879
880 (g) Added the -H (--with-filename) option.
881
882 (h) The combination of options -rh failed to suppress file names for files
883 that were found from directory arguments.
884
885 (i) Added the -D (--devices) and -d (--directories) options.
886
887 (j) Added the -F (--fixed-strings) option.
888
889 (k) Allow "-" to be used as a file name for -f as well as for a data file.
890
891 (l) Added the --colo(u)r option.
892
893 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
894 is not present by default.
895
896 3. A nasty bug was discovered in the handling of recursive patterns, that is,
897 items such as (?R) or (?1), when the recursion could match a number of
898 alternatives. If it matched one of the alternatives, but subsequently,
899 outside the recursion, there was a failure, the code tried to back up into
900 the recursion. However, because of the way PCRE is implemented, this is not
901 possible, and the result was an incorrect result from the match.
902
903 In order to prevent this happening, the specification of recursion has
904 been changed so that all such subpatterns are automatically treated as
905 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
906
907 4. I had overlooked the fact that, in some locales, there are characters for
908 which isalpha() is true but neither isupper() nor islower() are true. In
909 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
910 and ordfeminine) are like this. This affected the treatment of \w and \W
911 when they appeared in character classes, but not when they appeared outside
912 a character class. The bit map for "word" characters is now created
913 separately from the results of isalnum() instead of just taking it from the
914 upper, lower, and digit maps. (Plus the underscore character, of course.)
915
916 5. The above bug also affected the handling of POSIX character classes such as
917 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
918 permanent tables. Instead, the bit maps for such a class were previously
919 created as the appropriate unions of the upper, lower, and digit bitmaps.
920 Now they are created by subtraction from the [[:word:]] class, which has
921 its own bitmap.
922
923 6. The [[:blank:]] character class matches horizontal, but not vertical space.
924 It is created by subtracting the vertical space characters (\x09, \x0a,
925 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
926 subtraction was done in the overall bitmap for a character class, meaning
927 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
928 be recognized. This bug has been fixed.
929
930 7. Patches from the folks at Google:
931
932 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
933 real life, but is still worth protecting against".
934
935 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
936 regular expressions".
937
938 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
939 have it.
940
941 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
942 "configure" and the latter not, in order to fix a problem somebody had
943 with compiling the Arg class on HP-UX.
944
945 (e) Improve the error-handling of the C++ wrapper a little bit.
946
947 (f) New tests for checking recursion limiting.
948
949 8. The pcre_memmove() function, which is used only if the environment does not
950 have a standard memmove() function (and is therefore rarely compiled),
951 contained two bugs: (a) use of int instead of size_t, and (b) it was not
952 returning a result (though PCRE never actually uses the result).
953
954 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
955 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
956 returned instead of calling malloc() with an overflowing number that would
957 most likely cause subsequent chaos.
958
959 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
960
961 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
962 with this option is matched, the nmatch and pmatch options of regexec() are
963 ignored.
964
965 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
966 provided in case anyone wants to the the POSIX interface with UTF-8
967 strings.
968
969 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
970 C++ linking (needed for some HP-UX environments).
971
972 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
973 (unused parameter) and in the pcre_printint() function (omitted "default"
974 switch label when the default is to do nothing).
975
976 15. Added some code to make it possible, when PCRE is compiled as a C++
977 library, to replace subject pointers for pcre_exec() with a smart pointer
978 class, thus making it possible to process discontinuous strings.
979
980 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
981 much the same function. They were added by different people who were trying
982 to make PCRE easy to compile on non-Unix systems. It has been suggested
983 that PCRE_EXPORT be abolished now that there is more automatic apparatus
984 for compiling on Windows systems. I have therefore replaced it with
985 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
986 defaults to "extern" for C or "extern C" for C++, which works fine on
987 Unix-like systems. It is now possible to override the value of PCRE_DATA_
988 SCOPE with something explicit in config.h. In addition:
989
990 (a) pcreposix.h still had just "extern" instead of either of these macros;
991 I have replaced it with PCRE_DATA_SCOPE.
992
993 (b) Functions such as _pcre_xclass(), which are internal to the library,
994 but external in the C sense, all had PCRE_EXPORT in their definitions.
995 This is apparently wrong for the Windows case, so I have removed it.
996 (It makes no difference on Unix-like systems.)
997
998 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
999 of recursive calls to match(). This is different to MATCH_LIMIT because
1000 that limits the total number of calls to match(), not all of which increase
1001 the depth of recursion. Limiting the recursion depth limits the amount of
1002 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1003 when PCRE is compiled, and changed at run time. A patch from Google adds
1004 this functionality to the C++ interface.
1005
1006 18. Changes to the handling of Unicode character properties:
1007
1008 (a) Updated the table to Unicode 4.1.0.
1009
1010 (b) Recognize characters that are not in the table as "Cn" (undefined).
1011
1012 (c) I revised the way the table is implemented to a much improved format
1013 which includes recognition of ranges. It now supports the ranges that
1014 are defined in UnicodeData.txt, and it also amalgamates other
1015 characters into ranges. This has reduced the number of entries in the
1016 table from around 16,000 to around 3,000, thus reducing its size
1017 considerably. I realized I did not need to use a tree structure after
1018 all - a binary chop search is just as efficient. Having reduced the
1019 number of entries, I extended their size from 6 bytes to 8 bytes to
1020 allow for more data.
1021
1022 (d) Added support for Unicode script names via properties such as \p{Han}.
1023
1024 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1025 matching that character.
1026
1027 20. When matching a repeated Unicode property with a minimum greater than zero,
1028 (for example \pL{2,}), PCRE could look past the end of the subject if it
1029 reached it while seeking the minimum number of characters. This could
1030 happen only if some of the characters were more than one byte long, because
1031 there is a check for at least the minimum number of bytes.
1032
1033 21. Refactored the implementation of \p and \P so as to be more general, to
1034 allow for more different types of property in future. This has changed the
1035 compiled form incompatibly. Anybody with saved compiled patterns that use
1036 \p or \P will have to recompile them.
1037
1038 22. Added "Any" and "L&" to the supported property types.
1039
1040 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1041 but give a compile time error if the value is greater than 0xff.
1042
1043 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1044 accidentally not being installed or uninstalled.
1045
1046 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1047 made were to insert the current release number. This seemed silly, because
1048 it made things harder for people building PCRE on systems that don't run
1049 "configure". I have turned pcre.h into a distributed file, no longer built
1050 by "configure", with the version identification directly included. There is
1051 no longer a pcre.h.in file.
1052
1053 However, this change necessitated a change to the pcre-config script as
1054 well. It is built from pcre-config.in, and one of the substitutions was the
1055 release number. I have updated configure.ac so that ./configure now finds
1056 the release number by grepping pcre.h.
1057
1058 26. Added the ability to run the tests under valgrind.
1059
1060
1061 Version 6.4 05-Sep-05
1062 ---------------------
1063
1064 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1065 "--" to be printed when multiple files were scanned, even when none of the
1066 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1067 consider it to be a bug, and have restored the previous behaviour.
1068
1069 2. A couple of code tidies to get rid of compiler warnings.
1070
1071 3. The pcretest program used to cheat by referring to symbols in the library
1072 whose names begin with _pcre_. These are internal symbols that are not
1073 really supposed to be visible externally, and in some environments it is
1074 possible to suppress them. The cheating is now confined to including
1075 certain files from the library's source, which is a bit cleaner.
1076
1077 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1078 file's purpose clearer.
1079
1080 5. Reorganized pcre_ucp_findchar().
1081
1082
1083 Version 6.3 15-Aug-05
1084 ---------------------
1085
1086 1. The file libpcre.pc.in did not have general read permission in the tarball.
1087
1088 2. There were some problems when building without C++ support:
1089
1090 (a) If C++ support was not built, "make install" and "make test" still
1091 tried to test it.
1092
1093 (b) There were problems when the value of CXX was explicitly set. Some
1094 changes have been made to try to fix these, and ...
1095
1096 (c) --disable-cpp can now be used to explicitly disable C++ support.
1097
1098 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1099 backslash in a target when C++ was disabled. This confuses some
1100 versions of "make", apparently. Using an intermediate variable solves
1101 this. (Same for CPP_LOBJ.)
1102
1103 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1104 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1105 necessary on certain architectures.
1106
1107 4. Added a setting of -export-symbols-regex to the link command to remove
1108 those symbols that are exported in the C sense, but actually are local
1109 within the library, and not documented. Their names all begin with
1110 "_pcre_". This is not a perfect job, because (a) we have to except some
1111 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1112 available (and never for static libraries). I have made a note to try to
1113 find a way round (a) in the future.
1114
1115
1116 Version 6.2 01-Aug-05
1117 ---------------------
1118
1119 1. There was no test for integer overflow of quantifier values. A construction
1120 such as {1111111111111111} would give undefined results. What is worse, if
1121 a minimum quantifier for a parenthesized subpattern overflowed and became
1122 negative, the calculation of the memory size went wrong. This could have
1123 led to memory overwriting.
1124
1125 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1126
1127 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1128 operating environments where this matters.
1129
1130 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1131 PCRE options from within the C++ wrapper.
1132
1133 5. Named capturing subpatterns were not being correctly counted when a pattern
1134 was compiled. This caused two problems: (a) If there were more than 100
1135 such subpatterns, the calculation of the memory needed for the whole
1136 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1137 back references of the form \12, where the number was greater than 9, were
1138 not recognized as back references, even though there were sufficient
1139 previous subpatterns.
1140
1141 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1142 versions of gcc, e.g. 2.95.4.
1143
1144
1145 Version 6.1 21-Jun-05
1146 ---------------------
1147
1148 1. There was one reference to the variable "posix" in pcretest.c that was not
1149 surrounded by "#if !defined NOPOSIX".
1150
1151 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1152 the cross-check on the old pcre_info() function, for the benefit of the
1153 cut-down version of PCRE that is currently imported into Exim.
1154
1155 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1156 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1157 patterns that start (?i) but I don't think that matters. The use of (?i) is
1158 just an example; this all applies to the other options as well.
1159
1160 4. Since libtool seems to echo the compile commands it is issuing, the output
1161 from "make" can be reduced a bit by putting "@" in front of each libtool
1162 compile command.
1163
1164 5. Patch from the folks at Google for configure.in to be a bit more thorough
1165 in checking for a suitable C++ installation before trying to compile the
1166 C++ stuff. This should fix a reported problem when a compiler was present,
1167 but no suitable headers.
1168
1169 6. The man pages all had just "PCRE" as their title. I have changed them to
1170 be the relevant file name. I have also arranged that these names are
1171 retained in the file doc/pcre.txt, which is a concatenation in text format
1172 of all the man pages except the little individual ones for each function.
1173
1174 7. The NON-UNIX-USE file had not been updated for the different set of source
1175 files that come with release 6. I also added a few comments about the C++
1176 wrapper.
1177
1178
1179 Version 6.0 07-Jun-05
1180 ---------------------
1181
1182 1. Some minor internal re-organization to help with my DFA experiments.
1183
1184 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1185 didn't matter for the library itself when fully configured, but did matter
1186 when compiling without UCP support, or within Exim, where the ucp files are
1187 not imported.
1188
1189 3. Refactoring of the library code to split up the various functions into
1190 different source modules. The addition of the new DFA matching code (see
1191 below) to a single monolithic source would have made it really too
1192 unwieldy, quite apart from causing all the code to be include in a
1193 statically linked application, when only some functions are used. This is
1194 relevant even without the DFA addition now that patterns can be compiled in
1195 one application and matched in another.
1196
1197 The downside of splitting up is that there have to be some external
1198 functions and data tables that are used internally in different modules of
1199 the library but which are not part of the API. These have all had their
1200 names changed to start with "_pcre_" so that they are unlikely to clash
1201 with other external names.
1202
1203 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1204 a different (DFA) algorithm. Although it is slower than the original
1205 function, it does have some advantages for certain types of matching
1206 problem.
1207
1208 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1209 including restarting after a partial match.
1210
1211 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1212 defined when compiling for Windows was sent to me. I have put it into the
1213 code, though I have no means of testing or verifying it.
1214
1215 7. Added the pcre_refcount() auxiliary function.
1216
1217 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1218 match before or at the first newline in the subject string. In pcretest,
1219 the /f option on a pattern can be used to set this.
1220
1221 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1222 would behave wrongly. This has been present in PCRE since release 4.0.
1223
1224 10. A number of changes to the pcregrep command:
1225
1226 (a) Refactored how -x works; insert ^(...)$ instead of setting
1227 PCRE_ANCHORED and checking the length, in preparation for adding
1228 something similar for -w.
1229
1230 (b) Added the -w (match as a word) option.
1231
1232 (c) Refactored the way lines are read and buffered so as to have more
1233 than one at a time available.
1234
1235 (d) Implemented a pcregrep test script.
1236
1237 (e) Added the -M (multiline match) option. This allows patterns to match
1238 over several lines of the subject. The buffering ensures that at least
1239 8K, or the rest of the document (whichever is the shorter) is available
1240 for matching (and similarly the previous 8K for lookbehind assertions).
1241
1242 (f) Changed the --help output so that it now says
1243
1244 -w, --word-regex(p)
1245
1246 instead of two lines, one with "regex" and the other with "regexp"
1247 because that confused at least one person since the short forms are the
1248 same. (This required a bit of code, as the output is generated
1249 automatically from a table. It wasn't just a text change.)
1250
1251 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1252 option but starts with a hyphen. Could be a pattern or a path name
1253 starting with a hyphen, for instance.
1254
1255 (h) "-" can be given as a file name to represent stdin.
1256
1257 (i) When file names are being printed, "(standard input)" is used for
1258 the standard input, for compatibility with GNU grep. Previously
1259 "<stdin>" was used.
1260
1261 (j) The option --label=xxx can be used to supply a name to be used for
1262 stdin when file names are being printed. There is no short form.
1263
1264 (k) Re-factored the options decoding logic because we are going to add
1265 two more options that take data. Such options can now be given in four
1266 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1267
1268 (l) Added the -A, -B, and -C options for requesting that lines of context
1269 around matches be printed.
1270
1271 (m) Added the -L option to print the names of files that do not contain
1272 any matching lines, that is, the complement of -l.
1273
1274 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1275 continue to scan other files.
1276
1277 (o) The -s option was incorrectly implemented. For compatibility with other
1278 greps, it now suppresses the error message for a non-existent or non-
1279 accessible file (but not the return code). There is a new option called
1280 -q that suppresses the output of matching lines, which was what -s was
1281 previously doing.
1282
1283 (p) Added --include and --exclude options to specify files for inclusion
1284 and exclusion when recursing.
1285
1286 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1287 Hopefully, it now does.
1288
1289 12. Missing cast in pcre_study().
1290
1291 13. Added an "uninstall" target to the makefile.
1292
1293 14. Replaced "extern" in the function prototypes in Makefile.in with
1294 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1295 world, but is set differently for Windows.
1296
1297 15. Added a second compiling function called pcre_compile2(). The only
1298 difference is that it has an extra argument, which is a pointer to an
1299 integer error code. When there is a compile-time failure, this is set
1300 non-zero, in addition to the error test pointer being set to point to an
1301 error message. The new argument may be NULL if no error number is required
1302 (but then you may as well call pcre_compile(), which is now just a
1303 wrapper). This facility is provided because some applications need a
1304 numeric error indication, but it has also enabled me to tidy up the way
1305 compile-time errors are handled in the POSIX wrapper.
1306
1307 16. Added VPATH=.libs to the makefile; this should help when building with one
1308 prefix path and installing with another. (Or so I'm told by someone who
1309 knows more about this stuff than I do.)
1310
1311 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1312 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1313 match everything, including newlines. This is not POSIX-compatible, but
1314 somebody wanted the feature. From pcretest it can be activated by using
1315 both the P and the s flags.
1316
1317 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1318
1319 19. libpcre.pc was being incorrectly installed as executable.
1320
1321 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1322 it now also looks for '\r' so that it will work unmodified on Windows.
1323
1324 21. Added Google's contributed C++ wrapper to the distribution.
1325
1326 22. Added some untidy missing memory free() calls in pcretest, to keep
1327 Electric Fence happy when testing.
1328
1329
1330
1331 Version 5.0 13-Sep-04
1332 ---------------------
1333
1334 1. Internal change: literal characters are no longer packed up into items
1335 containing multiple characters in a single byte-string. Each character
1336 is now matched using a separate opcode. However, there may be more than one
1337 byte in the character in UTF-8 mode.
1338
1339 2. The pcre_callout_block structure has two new fields: pattern_position and
1340 next_item_length. These contain the offset in the pattern to the next match
1341 item, and its length, respectively.
1342
1343 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1344 insertion of callouts before each pattern item. Added the /C option to
1345 pcretest to make use of this.
1346
1347 4. On the advice of a Windows user, the lines
1348
1349 #if defined(_WIN32) || defined(WIN32)
1350 _setmode( _fileno( stdout ), 0x8000 );
1351 #endif /* defined(_WIN32) || defined(WIN32) */
1352
1353 have been added to the source of pcretest. This apparently does useful
1354 magic in relation to line terminators.
1355
1356 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1357 for the benefit of those environments where the "b" makes a difference.
1358
1359 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1360 to know about it. I have put a hack into configure.in that adds in code
1361 to set GCC=yes if CC=icc. This seems to end up at a point in the
1362 generated configure script that is early enough to affect the setting of
1363 compiler options, which is what is needed, but I have no means of testing
1364 whether it really works. (The user who reported this had patched the
1365 generated configure script, which of course I cannot do.)
1366
1367 LATER: After change 22 below (new libtool files), the configure script
1368 seems to know about icc (and also ecc). Therefore, I have commented out
1369 this hack in configure.in.
1370
1371 7. Added support for pkg-config (2 patches were sent in).
1372
1373 8. Negated POSIX character classes that used a combination of internal tables
1374 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1375 [[:^ascii]]. Typically, they would match almost any characters. The other
1376 POSIX classes were not broken in this way.
1377
1378 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1379 to find the match, as PCRE was deluded into thinking that the match had to
1380 start at the start point or following a newline. The same bug applied to
1381 patterns with negative forward assertions or any backward assertions
1382 preceding ".*" at the start, unless the pattern required a fixed first
1383 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1384
1385 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1386 starting at the last subject character, bytes beyond the end of the subject
1387 string were read.
1388
1389 11. Renamed the variable "class" as "classbits" to make life easier for C++
1390 users. (Previously there was a macro definition, but it apparently wasn't
1391 enough.)
1392
1393 12. Added the new field "tables" to the extra data so that tables can be passed
1394 in at exec time, or the internal tables can be re-selected. This allows
1395 a compiled regex to be saved and re-used at a later time by a different
1396 program that might have everything at different addresses.
1397
1398 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1399 -R library as well as a -L library.
1400
1401 14. The debugging options of pcretest (-d on the command line or D on a
1402 pattern) showed incorrect output for anything following an extended class
1403 that contained multibyte characters and which was followed by a quantifier.
1404
1405 15. Added optional support for general category Unicode character properties
1406 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1407 support. It adds about 90K to the size of the library. The meanings of the
1408 inbuilt class escapes such as \d and \s have NOT been changed.
1409
1410 16. Updated pcredemo.c to include calls to free() to release the memory for the
1411 compiled pattern.
1412
1413 17. The generated file chartables.c was being created in the source directory
1414 instead of in the building directory. This caused the build to fail if the
1415 source directory was different from the building directory, and was
1416 read-only.
1417
1418 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1419 file. No doubt somebody will tell me if they don't make sense... Also added
1420 Dan Mooney's comments about building on OpenVMS.
1421
1422 19. Added support for partial matching via the PCRE_PARTIAL option for
1423 pcre_exec() and the \P data escape in pcretest.
1424
1425 20. Extended pcretest with 3 new pattern features:
1426
1427 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1428 write the compiled pattern to the file whose name is "rest-of-line".
1429 This is a straight binary dump of the data, with the saved pointer to
1430 the character tables forced to be NULL. The study data, if any, is
1431 written too. After writing, pcretest reads a new pattern.
1432
1433 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1434 compiled pattern from the given file. There must not be any
1435 occurrences of "<" in the file name (pretty unlikely); if there are,
1436 pcretest will instead treat the initial "<" as a pattern delimiter.
1437 After reading in the pattern, pcretest goes on to read data lines as
1438 usual.
1439
1440 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1441 and 16-bit fields in a compiled pattern, to simulate a pattern that
1442 was compiled on a host of opposite endianness.
1443
1444 21. The pcre-exec() function can now cope with patterns that were compiled on
1445 hosts of opposite endianness, with this restriction:
1446
1447 As for any compiled expression that is saved and used later, the tables
1448 pointer field cannot be preserved; the extra_data field in the arguments
1449 to pcre_exec() should be used to pass in a tables address if a value
1450 other than the default internal tables were used at compile time.
1451
1452 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1453 now diagnosed as an error. Previously, most of the time, a negative number
1454 would have been treated as zero, but if in addition "ovector" was passed as
1455 NULL, a crash could occur.
1456
1457 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1458 new versions from the libtool 1.5 distribution (the last one is a copy of
1459 a file called libtool.m4). This seems to have fixed the need to patch
1460 "configure" to support Darwin 1.3 (which I used to do). However, I still
1461 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1462 workstation).
1463
1464 24. Changed the PCRE licence to be the more standard "BSD" licence.
1465
1466
1467 Version 4.5 01-Dec-03
1468 ---------------------
1469
1470 1. There has been some re-arrangement of the code for the match() function so
1471 that it can be compiled in a version that does not call itself recursively.
1472 Instead, it keeps those local variables that need separate instances for
1473 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1474 needs to "recurse". Keeping track of where control must go is done by means
1475 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1476 hide most of the details from the main code, and operates only if
1477 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1478 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1479 operating.
1480
1481 To make it easier for callers to provide specially tailored get/free
1482 functions for this usage, two new functions, pcre_stack_malloc, and
1483 pcre_stack_free, are used. They are always called in strict stacking order,
1484 and the size of block requested is always the same.
1485
1486 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1487 PCRE has been compiled to use the stack or the heap for recursion. The
1488 -C option of pcretest uses this to show which version is compiled.
1489
1490 A new data escape \S, is added to pcretest; it causes the amounts of store
1491 obtained and freed by both kinds of malloc/free at match time to be added
1492 to the output.
1493
1494 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1495 what's available on my current Linux desktop machine.
1496
1497 3. When matching a UTF-8 string, the test for a valid string at the start has
1498 been extended. If start_offset is not zero, PCRE now checks that it points
1499 to a byte that is the start of a UTF-8 character. If not, it returns
1500 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1501 this is necessary because there may be backward assertions in the pattern.
1502 When matching the same subject several times, it may save resources to use
1503 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1504
1505 4. The code for checking the validity of UTF-8 strings has been tightened so
1506 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1507 containing "overlong sequences".
1508
1509 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1510 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1511 should have been "&", but it just so happened that all the cases this let
1512 through by mistake were picked up later in the function.
1513
1514 6. I had used a variable called "isblank" - this is a C99 function, causing
1515 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1516
1517 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1518 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1519 so the version is shown; (c) stop "make test" echoing "./RunTest".
1520
1521 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1522
1523 9. The prototype for memmove() for systems that don't have it was using
1524 size_t, but the inclusion of the header that defines size_t was later. I've
1525 moved the #includes for the C headers earlier to avoid this.
1526
1527 10. Added some adjustments to the code to make it easier to compiler on certain
1528 special systems:
1529
1530 (a) Some "const" qualifiers were missing.
1531 (b) Added the macro EXPORT before all exported functions; by default this
1532 is defined to be empty.
1533 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1534 that it reads its output file name as an argument instead of writing
1535 to the standard output and assuming this can be redirected.
1536
1537 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1538 class containing characters with values greater than 255, PCRE compilation
1539 went into a loop.
1540
1541 12. A recursive reference to a subpattern that was within another subpattern
1542 that had a minimum quantifier of zero caused PCRE to crash. For example,
1543 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1544 recursion. If the recursively-called subpattern itself had a zero repeat,
1545 that was OK.
1546
1547 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1548 buffer into which it was copied (for escape processing) was still set at
1549 1024, so long lines caused crashes.
1550
1551 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1552 "internal error: code overflow...". This applied to any character class
1553 that was followed by a possessive quantifier.
1554
1555 15. Modified the Makefile to add libpcre.la as a prerequisite for
1556 libpcreposix.la because I was told this is needed for a parallel build to
1557 work.
1558
1559 16. If a pattern that contained .* following optional items at the start was
1560 studied, the wrong optimizing data was generated, leading to matching
1561 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1562 matching string must start with a or b or c. The correct conclusion for
1563 this pattern is that a match can start with any character.
1564
1565
1566 Version 4.4 13-Aug-03
1567 ---------------------
1568
1569 1. In UTF-8 mode, a character class containing characters with values between
1570 127 and 255 was not handled correctly if the compiled pattern was studied.
1571 In fixing this, I have also improved the studying algorithm for such
1572 classes (slightly).
1573
1574 2. Three internal functions had redundant arguments passed to them. Removal
1575 might give a very teeny performance improvement.
1576
1577 3. Documentation bug: the value of the capture_top field in a callout is *one
1578 more than* the number of the hightest numbered captured substring.
1579
1580 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1581 in incorrectly linking with a previously installed version. They now link
1582 explicitly with libpcre.la.
1583
1584 5. configure.in no longer needs to recognize Cygwin specially.
1585
1586 6. A problem in pcre.in for Windows platforms is fixed.
1587
1588 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1589 pcretest, it used to include the size of the study block as part of its
1590 output. Unfortunately, the structure contains a field that has a different
1591 size on different hardware architectures. This meant that the tests that
1592 showed this size failed. As the block is currently always of a fixed size,
1593 this information isn't actually particularly useful in pcretest output, so
1594 I have just removed it.
1595
1596 8. Three pre-processor statements accidentally did not start in column 1.
1597 Sadly, there are *still* compilers around that complain, even though
1598 standard C has not required this for well over a decade. Sigh.
1599
1600 9. In pcretest, the code for checking callouts passed small integers in the
1601 callout_data field, which is a void * field. However, some picky compilers
1602 complained about the casts involved for this on 64-bit systems. Now
1603 pcretest passes the address of the small integer instead, which should get
1604 rid of the warnings.
1605
1606 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1607 both compile and run time, and gives an error if an invalid UTF-8 sequence
1608 is found. There is a option for disabling this check in cases where the
1609 string is known to be correct and/or the maximum performance is wanted.
1610
1611 11. In response to a bug report, I changed one line in Makefile.in from
1612
1613 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1614 to
1615 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1616
1617 to look similar to other lines, but I have no way of telling whether this
1618 is the right thing to do, as I do not use Windows. No doubt I'll get told
1619 if it's wrong...
1620
1621
1622 Version 4.3 21-May-03
1623 ---------------------
1624
1625 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1626 Makefile.
1627
1628 2. Some refactoring to improve the quality of the code:
1629
1630 (i) The utf8_table... variables are now declared "const".
1631
1632 (ii) The code for \cx, which used the "case flipping" table to upper case
1633 lower case letters, now just substracts 32. This is ASCII-specific,
1634 but the whole concept of \cx is ASCII-specific, so it seems
1635 reasonable.
1636
1637 (iii) PCRE was using its character types table to recognize decimal and
1638 hexadecimal digits in the pattern. This is silly, because it handles
1639 only 0-9, a-f, and A-F, but the character types table is locale-
1640 specific, which means strange things might happen. A private
1641 table is now used for this - though it costs 256 bytes, a table is
1642 much faster than multiple explicit tests. Of course, the standard
1643 character types table is still used for matching digits in subject
1644 strings against \d.
1645
1646 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1647 ending in _t are). So I've renamed it as ESC_tee.
1648
1649 3. The first argument for regexec() in the POSIX wrapper should have been
1650 defined as "const".
1651
1652 4. Changed pcretest to use malloc() for its buffers so that they can be
1653 Electric Fenced for debugging.
1654
1655 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1656 to read one or more bytes before the start of the subject string. Often this
1657 had no effect on PCRE's behaviour, but in some circumstances it could
1658 provoke a segmentation fault.
1659
1660 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1661 to try to read one or more bytes before the start of the subject string.
1662
1663 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1664 UTF-8 support could misbehave in various ways if the subject string
1665 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1666 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1667 back over UTF-8 characters.)
1668
1669
1670 Version 4.2 14-Apr-03
1671 ---------------------
1672
1673 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1674
1675 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1676 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1677 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1678 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1679 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1680 and BUILD_EXEEXT
1681 Note: automatic setting of the BUILD variables is not yet working
1682 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1683 compile-time but not at link-time
1684 [LINK]: use for linking executables only
1685 make different versions for Windows and non-Windows
1686 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1687 libraries
1688 [LINK_FOR_BUILD]: new variable
1689 [OBJEXT]: use throughout
1690 [EXEEXT]: use throughout
1691 <winshared>: new target
1692 <wininstall>: new target
1693 <dftables.o>: use native compiler
1694 <dftables>: use native linker
1695 <install>: handle Windows platform correctly
1696 <clean>: ditto
1697 <check>: ditto
1698 copy DLL to top builddir before testing
1699
1700 As part of these changes, -no-undefined was removed again. This was reported
1701 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1702 in any case.
1703
1704 3. Some tidies to get rid of compiler warnings:
1705
1706 . In the match_data structure, match_limit was an unsigned long int, whereas
1707 match_call_count was an int. I've made them both unsigned long ints.
1708
1709 . In pcretest the fact that a const uschar * doesn't automatically cast to
1710 a void * provoked a warning.
1711
1712 . Turning on some more compiler warnings threw up some "shadow" variables
1713 and a few more missing casts.
1714
1715 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1716 option, a class that contained a single character with a value between 128
1717 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1718
1719 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1720 option, a class that contained several characters, but with at least one
1721 whose value was between 128 and 255 caused PCRE to crash.
1722
1723
1724 Version 4.1 12-Mar-03
1725 ---------------------
1726
1727 1. Compiling with gcc -pedantic found a couple of places where casts were
1728 needed, and a string in dftables.c that was longer than standard compilers are
1729 required to support.
1730
1731 2. Compiling with Sun's compiler found a few more places where the code could
1732 be tidied up in order to avoid warnings.
1733
1734 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1735 first of these names is deprecated in the latest Autoconf in favour of the name
1736 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1737 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1738 analogy I have changed it to CFLAGS_FOR_BUILD.
1739
1740 4. Added -no-undefined to the linking command in the Makefile, because this is
1741 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1742 linking step for the pcreposix library.
1743
1744 5. PCRE was failing to diagnose the case of two named groups with the same
1745 name.
1746
1747 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1748 literal character that is needed in the subject for a match, and scans along to
1749 ensure that it is present before embarking on the full matching process. This
1750 saves time in cases of nested unlimited repeats that are never going to match.
1751 Problem: the scan can take a lot of time if the subject is very long (e.g.
1752 megabytes), thus penalizing straightforward matches. It is now done only if the
1753 amount of subject to be scanned is less than 1000 bytes.
1754
1755 7. A lesser problem with the same optimization is that it was recording the
1756 first character of an anchored pattern as "needed", thus provoking a search
1757 right along the subject, even when the first match of the pattern was going to
1758 fail. The "needed" character is now not set for anchored patterns, unless it
1759 follows something in the pattern that is of non-fixed length. Thus, it still
1760 fulfils its original purpose of finding quick non-matches in cases of nested
1761 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
1762
1763
1764 Version 4.0 17-Feb-03
1765 ---------------------
1766
1767 1. If a comment in an extended regex that started immediately after a meta-item
1768 extended to the end of string, PCRE compiled incorrect data. This could lead to
1769 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
1770
1771 2. Moved to autoconf 2.53 and libtool 1.4.2.
1772
1773 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
1774 the special perltest8 script is no longer needed - all the tests can be run
1775 from a single perltest script.
1776
1777 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
1778 by \s. It has now been removed in PCRE. This means it isn't recognized as
1779 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
1780 class [:space:] *does* include VT, thereby creating a mess.
1781
1782 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
1783 space and tab.
1784
1785 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
1786 its new features into the main test script, reducing the number of scripts.
1787
1788 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
1789 were backward compatible, and made the (?i) apply to the whole pattern, as if
1790 /i were given. Now it behaves more logically, and applies the option setting
1791 only to what follows. PCRE has been changed to follow suit. However, if it
1792 finds options settings right at the start of the pattern, it extracts them into
1793 the global options, as before. Thus, they show up in the info data.
1794
1795 8. Added support for the \Q...\E escape sequence. Characters in between are
1796 treated as literals. This is slightly different from Perl in that $ and @ are
1797 also handled as literals inside the quotes. In Perl, they will cause variable
1798 interpolation. Note the following examples:
1799
1800 Pattern PCRE matches Perl matches
1801
1802 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
1803 \Qabc\$xyz\E abc\$xyz abc\$xyz
1804 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
1805
1806 For compatibility with Perl, \Q...\E sequences are recognized inside character
1807 classes as well as outside them.
1808
1809 9. Re-organized 3 code statements in pcretest to avoid "overflow in
1810 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
1811 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
1812 signed/unsigned warnings.
1813
1814 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
1815 option for pcretest, so I've replaced it by a simple function that does just
1816 that job.
1817
1818 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
1819 "pcregrep -".
1820
1821 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
1822 Java package. This provides some syntactic sugar for simple cases of what my
1823 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
1824 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
1825 item, you can use this simplified notation. Note that only makes sense with
1826 greedy quantifiers. Consequently, the use of the possessive quantifier forces
1827 greediness, whatever the setting of the PCRE_UNGREEDY option.
1828
1829 13. A change of greediness default within a pattern was not taking effect at
1830 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
1831 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
1832 was abstracted outside.
1833
1834 14. PCRE now supports the \G assertion. It is true when the current matching
1835 position is at the start point of the match. This differs from \A when the
1836 starting offset is non-zero. Used with the /g option of pcretest (or similar
1837 code), it works in the same way as it does for Perl's /g option. If all
1838 alternatives of a regex begin with \G, the expression is anchored to the start
1839 match position, and the "anchored" flag is set in the compiled expression.
1840
1841 15. Some bugs concerning the handling of certain option changes within patterns
1842 have been fixed. These applied to options other than (?ims). For example,
1843 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
1844 been the other way round. Some of this was related to change 7 above.
1845
1846 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
1847 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
1848 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
1849 POSIX classes only within a class (e.g. /[[:alpha:]]/).
1850
1851 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
1852 mode. Unlike ".", it always matches newline, whatever the setting of
1853 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
1854 assertions. Perl allows it, but it doesn't (in general) work because it can't
1855 calculate the length of the lookbehind. At least, that's the case for Perl
1856 5.8.0 - I've been told they are going to document that it doesn't work in
1857 future.
1858
1859 18. Added an error diagnosis for escapes that PCRE does not support: these are
1860 \L, \l, \N, \P, \p, \U, \u, and \X.
1861
1862 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
1863 reading past the end of the pattern in cases such as /[abcd/.
1864
1865 20. PCRE was getting more memory than necessary for patterns with classes that
1866 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
1867
1868 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
1869 compiling PCRE for use with Virtual Pascal.
1870
1871 22. Small fix to the Makefile to make it work properly if the build is done
1872 outside the source tree.
1873
1874 23. Added a new extension: a condition to go with recursion. If a conditional
1875 subpattern starts with (?(R) the "true" branch is used if recursion has
1876 happened, whereas the "false" branch is used only at the top level.
1877
1878 24. When there was a very long string of literal characters (over 255 bytes
1879 without UTF support, over 250 bytes with UTF support), the computation of how
1880 much memory was required could be incorrect, leading to segfaults or other
1881 strange effects.
1882
1883 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
1884 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
1885 there was a subsequent back reference to those brackets. This meant that, for
1886 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
1887 possible to check for precisely this case. All we can do is abandon the
1888 optimization if .* occurs inside capturing brackets when there are any back
1889 references whatsoever. (See below for a better fix that came later.)
1890
1891 26. The handling of the optimization for finding the first character of a
1892 non-anchored pattern, and for finding a character that is required later in the
1893 match were failing in some cases. This didn't break the matching; it just
1894 failed to optimize when it could. The way this is done has been re-implemented.
1895
1896 27. Fixed typo in error message for invalid (?R item (it said "(?p").
1897
1898 28. Added a new feature that provides some of the functionality that Perl
1899 provides with (?{...}). The facility is termed a "callout". The way it is done
1900 in PCRE is for the caller to provide an optional function, by setting
1901 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
1902 global variable. By default it is unset, which disables all calling out. To get
1903 the function called, the regex must include (?C) at appropriate points. This
1904 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
1905 This provides a means of identifying different callout points. When PCRE
1906 reaches such a point in the regex, if pcre_callout has been set, the external
1907 function is called. It is provided with data in a structure called
1908 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
1909 matching continues; if it returns a non-zero value, the match at the current
1910 point fails. However, backtracking will occur if possible. [This was changed
1911 later and other features added - see item 49 below.]
1912
1913 29. pcretest is upgraded to test the callout functionality. It provides a
1914 callout function that displays information. By default, it shows the start of
1915 the match and the current position in the text. There are some new data escapes
1916 to vary what happens:
1917
1918 \C+ in addition, show current contents of captured substrings
1919 \C- do not supply a callout function
1920 \C!n return 1 when callout number n is reached
1921 \C!n!m return 1 when callout number n is reached for the mth time
1922
1923 30. If pcregrep was called with the -l option and just a single file name, it
1924 output "<stdin>" if a match was found, instead of the file name.
1925
1926 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
1927 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
1928 pcre_exec(). This saves a malloc/free per call. The default value of
1929 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
1930 when configuring.
1931
1932 32. The default maximum size of a compiled pattern is 64K. There have been a
1933 few cases of people hitting this limit. The code now uses macros to handle the
1934 storing of links as offsets within the compiled pattern. It defaults to 2-byte
1935 links, but this can be changed to 3 or 4 bytes by --with-link-size when
1936 configuring. Tests 2 and 5 work only with 2-byte links because they output
1937 debugging information about compiled patterns.
1938
1939 33. Internal code re-arrangements:
1940
1941 (a) Moved the debugging function for printing out a compiled regex into
1942 its own source file (printint.c) and used #include to pull it into
1943 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
1944 separate copies.
1945
1946 (b) Defined the list of op-code names for debugging as a macro in
1947 internal.h so that it is next to the definition of the opcodes.
1948
1949 (c) Defined a table of op-code lengths for simpler skipping along compiled
1950 code. This is again a macro in internal.h so that it is next to the
1951 definition of the opcodes.
1952
1953 34. Added support for recursive calls to individual subpatterns, along the
1954 lines of Robin Houston's patch (but implemented somewhat differently).
1955
1956 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
1957 allow it to read and process whole directories in Win32. This code was
1958 contributed by Lionel Fourquaux; it has not been tested by me.
1959
1960 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
1961 used to name a group. Names consist of alphanumerics and underscores, and must
1962 be unique. Back references use the syntax (?P=name) and recursive calls use
1963 (?P>name) which is a PCRE extension to the Python extension. Groups still have
1964 numbers. The function pcre_fullinfo() can be used after compilation to extract
1965 a name/number map. There are three relevant calls:
1966
1967 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
1968 PCRE_INFO_NAMECOUNT yields the number of entries
1969 PCRE_INFO_NAMETABLE yields a pointer to the map.
1970
1971 The map is a vector of fixed-size entries. The size of each entry depends on
1972 the length of the longest name used. The first two bytes of each entry are the
1973 group number, most significant byte first. There follows the corresponding
1974 name, zero terminated. The names are in alphabetical order.
1975
1976 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
1977 case instead of 255. Making it the same both with and without UTF-8 support
1978 means that the same test output works with both.
1979
1980 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
1981 calling malloc() with a zero argument.
1982
1983 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
1984 optimization. I've improved things by keeping a bitmap of backreferences with
1985 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
1986 fact referenced, the optimization can be applied. It is unlikely that a
1987 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
1988 the match to follow \n) will appear inside brackets with a number greater than
1989 31, but if it does, any back reference > 31 suppresses the optimization.
1990
1991 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
1992 of disabling numbered capturing parentheses. Any opening parenthesis that is
1993 not followed by ? behaves as if it were followed by ?: but named parentheses
1994 can still be used for capturing (and they will acquire numbers in the usual
1995 way).
1996
1997 41. Redesigned the return codes from the match() function into yes/no/error so
1998 that errors can be passed back from deep inside the nested calls. A malloc
1999 failure while inside a recursive subpattern call now causes the
2000 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2001
2002 42. It is now possible to set a limit on the number of times the match()
2003 function is called in a call to pcre_exec(). This facility makes it possible to
2004 limit the amount of recursion and backtracking, though not in a directly
2005 obvious way, because the match() function is used in a number of different
2006 circumstances. The count starts from zero for each position in the subject
2007 string (for non-anchored patterns). The default limit is, for compatibility, a
2008 large number, namely 10 000 000. You can change this in two ways:
2009
2010 (a) When configuring PCRE before making, you can use --with-match-limit=n
2011 to set a default value for the compiled library.
2012
2013 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2014 a different value is set. See 45 below.
2015
2016 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2017
2018 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2019 of things that can be changed at compile time. The first argument specifies
2020 what is wanted and the second points to where the information is to be placed.
2021 The current list of available information is:
2022
2023 PCRE_CONFIG_UTF8
2024
2025 The output is an integer that is set to one if UTF-8 support is available;
2026 otherwise it is set to zero.
2027
2028 PCRE_CONFIG_NEWLINE
2029
2030 The output is an integer that it set to the value of the code that is used for
2031 newline. It is either LF (10) or CR (13).
2032
2033 PCRE_CONFIG_LINK_SIZE
2034
2035 The output is an integer that contains the number of bytes used for internal
2036 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2037
2038 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2039
2040 The output is an integer that contains the threshold above which the POSIX
2041 interface uses malloc() for output vectors. See item 31 above.
2042
2043 PCRE_CONFIG_MATCH_LIMIT
2044
2045 The output is an unsigned integer that contains the default limit of the number
2046 of match() calls in a pcre_exec() execution. See 42 above.
2047
2048 44. pcretest has been upgraded by the addition of the -C option. This causes it
2049 to extract all the available output from the new pcre_config() function, and to
2050 output it. The program then exits immediately.
2051
2052 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2053 order to support additional features. One way would have been to define
2054 pcre_exec2() (for example) with extra arguments, but this would not have been
2055 extensible, and would also have required all calls to the original function to
2056 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2057 is used for passing in "extra" data from pcre_study().
2058
2059 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2060 contains the following fields:
2061
2062 flags a bitmap indicating which of the following fields are set
2063 study_data opaque data from pcre_study()
2064 match_limit a way of specifying a limit on match() calls for a specific
2065 call to pcre_exec()
2066 callout_data data for callouts (see 49 below)
2067
2068 The flag bits are also defined in pcre.h, and are
2069
2070 PCRE_EXTRA_STUDY_DATA
2071 PCRE_EXTRA_MATCH_LIMIT
2072 PCRE_EXTRA_CALLOUT_DATA
2073
2074 The pcre_study() function now returns one of these new pcre_extra blocks, with
2075 the actual study data pointed to by the study_data field, and the
2076 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2077 before. That is, this change is entirely upwards-compatible and requires no
2078 change to existing code.
2079
2080 If you want to pass in additional data to pcre_exec(), you can either place it
2081 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2082 block.
2083
2084 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2085 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2086 times with different match limits, until it finds the minimum value needed for
2087 pcre_exec() to complete. The value is then output. This can be instructive; for
2088 most simple matches the number is quite small, but for pathological cases it
2089 gets very large very quickly.
2090
2091 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2092 returns the size of the data block pointed to by the study_data field in a
2093 pcre_extra block, that is, the value that was passed as the argument to
2094 pcre_malloc() when PCRE was getting memory in which to place the information
2095 created by pcre_study(). The fourth argument should point to a size_t variable.
2096 pcretest has been extended so that this information is shown after a successful
2097 pcre_study() call when information about the compiled regex is being displayed.
2098
2099 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2100 because what follows is always an absolute path. (Later: it turns out that this
2101 is more than cosmetic for MinGW, because it doesn't like empty path
2102 components.)
2103
2104 49. Some changes have been made to the callout feature (see 28 above):
2105
2106 (i) A callout function now has three choices for what it returns:
2107
2108 0 => success, carry on matching
2109 > 0 => failure at this point, but backtrack if possible
2110 < 0 => serious error, return this value from pcre_exec()
2111
2112 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2113 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2114 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2115 use by callout functions. It will never be used by PCRE itself.
2116
2117 (ii) The pcre_extra structure (see 45 above) has a void * field called
2118 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2119 pcre_callout_block structure has a field of the same name. The contents of
2120 the field passed in the pcre_extra structure are passed to the callout
2121 function in the corresponding field in the callout block. This makes it
2122 easier to use the same callout-containing regex from multiple threads. For
2123 testing, the pcretest program has a new data escape
2124
2125 \C*n pass the number n (may be negative) as callout_data
2126
2127 If the callout function in pcretest receives a non-zero value as
2128 callout_data, it returns that value.
2129
2130 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2131 there were some redundant $(CFLAGS) in commands that are now specified as
2132 $(LINK), which already includes $(CFLAGS).
2133
2134 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2135 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2136 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2137 one-byte characters throughout. Note that case-insensitive matching applies
2138 only to characters whose values are less than 256. PCRE doesn't support the
2139 notion of cases for higher-valued characters.
2140
2141 (i) A character class whose characters are all within 0-255 is handled as
2142 a bit map, and the map is inverted for negative classes. Previously, a
2143 character > 255 always failed to match such a class; however it should
2144 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2145
2146 (ii) A negated character class with a single character < 255 is coded as
2147 "not this character" (OP_NOT). This wasn't working properly when the test
2148 character was multibyte, either singly or repeated.
2149
2150 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2151 mode, for example: \x{100}{2,3}.
2152
2153 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2154 singly or repeated) now correctly test multibyte characters. However,
2155 PCRE doesn't recognize any characters with values greater than 255 as
2156 digits, spaces, or word characters. Such characters always match \D, \S,
2157 and \W, and never match \d, \s, or \w.
2158
2159 (v) Classes may now contain characters and character ranges with values
2160 greater than 255. For example: [ab\x{100}-\x{400}].
2161
2162 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2163 PCRE in UTF-8 mode.
2164
2165 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2166 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2167 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2168 value.)
2169
2170 53. The single man page has become too large. I have therefore split it up into
2171 a number of separate man pages. These also give rise to individual HTML pages;
2172 these are now put in a separate directory, and there is an index.html page that
2173 lists them all. Some hyperlinking between the pages has been installed.
2174
2175 54. Added convenience functions for handling named capturing parentheses.
2176
2177 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2178 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2179 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2180 are faulted.
2181
2182 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2183 calling configure. These values are used when compiling the dftables.c program
2184 which is run to generate the source of the default character tables. They
2185 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2186 you will need to set these values.
2187
2188 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2189
2190
2191 Version 3.9 02-Jan-02
2192 ---------------------
2193
2194 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2195
2196 2. If --disable-static was given, the building process failed when trying to
2197 build pcretest and pcregrep. (For some reason it was using libtool to compile
2198 them, which is not right, as they aren't part of the library.)
2199
2200
2201 Version 3.8 18-Dec-01
2202 ---------------------
2203
2204 1. The experimental UTF-8 code was completely screwed up. It was packing the
2205 bytes in the wrong order. How dumb can you get?
2206
2207
2208 Version 3.7 29-Oct-01
2209 ---------------------
2210
2211 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2212 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2213 this didn't happen under Solaris 8, where I normally test things.
2214
2215 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2216 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2217 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2218 this fix an hour or so after the initial 3.7 release.)
2219
2220
2221 Version 3.6 23-Oct-01
2222 ---------------------
2223
2224 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2225 offsets passed as NULL with zero offset count.
2226
2227 2. The config.guess and config.sub files had not been updated when I moved to
2228 the latest autoconf.
2229
2230
2231 Version 3.5 15-Aug-01
2232 ---------------------
2233
2234 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2235 had been forgotten.
2236
2237 2. By using declared but undefined structures, we can avoid using "void"
2238 definitions in pcre.h while keeping the internal definitions of the structures
2239 private.
2240
2241 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2242 user point of view, this means that both static and shared libraries are built
2243 by default, but this can be individually controlled. More of the work of
2244 handling this static/shared cases is now inside libtool instead of PCRE's make
2245 file.
2246
2247 4. The pcretest utility is now installed along with pcregrep because it is
2248 useful for users (to test regexs) and by doing this, it automatically gets
2249 relinked by libtool. The documentation has been turned into a man page, so
2250 there are now .1, .txt, and .html versions in /doc.
2251
2252 5. Upgrades to pcregrep:
2253 (i) Added long-form option names like gnu grep.
2254 (ii) Added --help to list all options with an explanatory phrase.
2255 (iii) Added -r, --recursive to recurse into sub-directories.
2256 (iv) Added -f, --file to read patterns from a file.
2257
2258 6. pcre_exec() was referring to its "code" argument before testing that
2259 argument for NULL (and giving an error if it was NULL).
2260
2261 7. Upgraded Makefile.in to allow for compiling in a different directory from
2262 the source directory.
2263
2264 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2265 options bits, the pointer it was passed was to an int instead of to an unsigned
2266 long int. This mattered only on 64-bit systems.
2267
2268 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2269 generated) instead of pcre.in, which it its source. Also made the same change
2270 in several of the .c files.
2271
2272 10. A new release of gcc defines printf() as a macro, which broke pcretest
2273 because it had an ifdef in the middle of a string argument for printf(). Fixed
2274 by using separate calls to printf().
2275
2276 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2277 script, to force use of CR or LF instead of \n in the source. On non-Unix
2278 systems, the value can be set in config.h.
2279
2280 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2281 absolute limit. Changed the text of the error message to make this clear, and
2282 likewise updated the man page.
2283
2284 13. The limit of 99 on the number of capturing subpatterns has been removed.
2285 The new limit is 65535, which I hope will not be a "real" limit.
2286
2287
2288 Version 3.4 22-Aug-00
2289 ---------------------
2290
2291 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2292
2293 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2294
2295
2296 Version 3.3 01-Aug-00
2297 ---------------------
2298
2299 1. If an octal character was given, but the value was greater than \377, it
2300 was not getting masked to the least significant bits, as documented. This could
2301 lead to crashes in some systems.
2302
2303 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2304 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2305
2306 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2307 These just pass their arguments on to (pcre_free)(), but they are provided
2308 because some uses of PCRE bind it to non-C systems that can call its functions,
2309 but cannot call free() or pcre_free() directly.
2310
2311 4. Add "make test" as a synonym for "make check". Corrected some comments in
2312 the Makefile.
2313
2314 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2315 Makefile.
2316
2317 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2318 command called pgrep for grepping around the active processes.
2319
2320 7. Added the beginnings of support for UTF-8 character strings.
2321
2322 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2323 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2324 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2325 out for the ar command.)
2326
2327
2328 Version 3.2 12-May-00
2329 ---------------------
2330
2331 This is purely a bug fixing release.
2332
2333 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2334 of ZA. This was just one example of several cases that could provoke this bug,
2335 which was introduced by change 9 of version 2.00. The code for breaking
2336 infinite loops after an iteration that matches an empty string was't working
2337 correctly.
2338
2339 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2340 when matched against abbab (for example). After matching an empty string, it
2341 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2342 caused it to match further down the string than it should.
2343
2344 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2345 was there because it doesn't seem to be needed, and it causes trouble on some
2346 systems, as it is not a Standard C header. It has been removed.
2347
2348 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2349 were reported on the Macintosh. The changes were from
2350
2351 while ((c = *(++ptr)) != 0 && c != '\n');
2352 to
2353 while ((c = *(++ptr)) != 0 && c != '\n') ;
2354
2355 Totally extraordinary, but if that's what it takes...
2356
2357 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2358 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2359 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2360 assumes the way PCRE uses memmove() (always moving upwards).
2361
2362 6. PCRE is being used in one environment where strchr() is not available. There
2363 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2364 faster code anyway.
2365
2366
2367 Version 3.1 09-Feb-00
2368 ---------------------
2369
2370 The only change in this release is the fixing of some bugs in Makefile.in for
2371 the "install" target:
2372
2373 (1) It was failing to install pcreposix.h.
2374
2375 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2376
2377
2378 Version 3.0 01-Feb-00
2379 ---------------------
2380
2381 1. Add support for the /+ modifier to perltest (to output $` like it does in
2382 pcretest).
2383
2384 2. Add support for the /g modifier to perltest.
2385
2386 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2387 matches null strings.
2388
2389 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2390 pattern. Perl treats empty patterns specially - it reuses the most recent
2391 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2392 effect.
2393
2394 5. The POSIX interface was broken in that it was just handing over the POSIX
2395 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2396 required a bigger vector, with some working space on the end. This means that
2397 the POSIX wrapper now has to get and free some memory, and copy the results.
2398
2399 6. Added some simple autoconf support, placing the test data and the
2400 documentation in separate directories, re-organizing some of the
2401 information files, and making it build pcre-config (a GNU standard). Also added
2402 libtool support for building PCRE as a shared library, which is now the
2403 default.
2404
2405 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2406 09 are not valid octal constants. Single digits will be used for minor values
2407 less than 10.
2408
2409 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2410 existing programs that set these in the POSIX interface can use PCRE without
2411 modification.
2412
2413 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2414 return all that pcre_info() returns, plus additional data. The pcre_info()
2415 function is retained for compatibility, but is considered to be obsolete.
2416
2417 10. Added experimental recursion feature (?R) to handle one common case that
2418 Perl 5.6 will be able to do with (?p{...}).
2419
2420 11. Added support for POSIX character classes like [:alpha:], which Perl is
2421 adopting.
2422
2423
2424 Version 2.08 31-Aug-99
2425 ----------------------
2426
2427 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2428 trying to match at the startoffset position, but instead was moving forward to
2429 the next newline as if a previous match had failed.
2430
2431 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2432 and could get into a loop if a null string was matched other than at the start
2433 of the subject.
2434
2435 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2436 be distinguished at compile time, and for completeness also added PCRE_DATE.
2437
2438 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2439 in GnuWin32 environments.
2440
2441
2442 Version 2.07 29-Jul-99
2443 ----------------------
2444
2445 1. The documentation is now supplied in plain text form and HTML as well as in
2446 the form of man page sources.
2447
2448 2. C++ compilers don't like assigning (void *) values to other pointer types.
2449 In particular this affects malloc(). Although there is no problem in Standard
2450 C, I've put in casts to keep C++ compilers happy.
2451
2452 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2453 should be (const char *).
2454
2455 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2456 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2457 However, I haven't made this a standard facility. The documentation doesn't
2458 mention it, and the Makefile doesn't support it.
2459
2460 5. The Makefile now contains an "install" target, with editable destinations at
2461 the top of the file. The pcretest program is not installed.
2462
2463 6. pgrep -V now gives the PCRE version number and date.
2464
2465 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2466 causing the entire string to be ignored, instead of just the last character.
2467
2468 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2469 non-matching string, it can take a very, very long time, even for strings of
2470 quite modest length, because of the nested recursion. PCRE now does better in
2471 some of these cases. It does this by remembering the last required literal
2472 character in the pattern, and pre-searching the subject to ensure it is present
2473 before running the real match. In other words, it applies a heuristic to detect
2474 some types of certain failure quickly, and in the above example, if presented
2475 with a string that has no trailing " it gives "no match" very quickly.
2476
2477 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2478 other alternatives are tried instead.
2479
2480
2481 Version 2.06 09-Jun-99
2482 ----------------------
2483
2484 1. Change pcretest's output for amount of store used to show just the code
2485 space, because the remainder (the data block) varies in size between 32-bit and
2486 64-bit systems.
2487
2488 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2489 start matching at. This allows lookbehinds to work when searching for multiple
2490 occurrences in a string.
2491
2492 3. Added additional options to pcretest for testing multiple occurrences:
2493
2494 /+ outputs the rest of the string that follows a match
2495 /g loops for multiple occurrences, using the new startoffset argument
2496 /G loops for multiple occurrences by passing an incremented pointer
2497
2498 4. PCRE wasn't doing the "first character" optimization for patterns starting
2499 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2500 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2501 the letter 'x'. On long subject strings, this gives a significant speed-up.
2502
2503
2504 Version 2.05 21-Apr-99
2505 ----------------------
2506
2507 1. Changed the type of magic_number from int to long int so that it works
2508 properly on 16-bit systems.
2509
2510 2. Fixed a bug which caused patterns starting with .* not to work correctly
2511 when the subject string contained newline characters. PCRE was assuming
2512 anchoring for such patterns in all cases, which is not correct because .* will
2513 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2514 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2515 must be retried after every newline in the subject.
2516
2517
2518 Version 2.04 18-Feb-99
2519 ----------------------
2520
2521 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2522 computation of the store needed to hold the pattern was incorrect (too large).
2523 If such patterns were nested a few deep, this could multiply and become a real
2524 problem.
2525
2526 2. Added /M option to pcretest to show the memory requirement of a specific
2527 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2528
2529 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2530 compiled in such a way that the backtracking after subsequent failure was
2531 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2532 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2533
2534
2535 Version 2.03 02-Feb-99
2536 ----------------------
2537
2538 1. Fixed typo and small mistake in man page.
2539
2540 2. Added 4th condition (GPL supersedes if conflict) and created separate
2541 LICENCE file containing the conditions.
2542
2543 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2544 Perl, that is the internal \ allows the delimiter to be included in the
2545 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2546 the final delimiter, add \ to the end of the pattern (to test the error).
2547
2548 4. Added the convenience functions for extracting substrings after a successful
2549 match. Updated pcretest to make it able to test these functions.
2550
2551
2552 Version 2.02 14-Jan-99
2553 ----------------------
2554
2555 1. Initialized the working variables associated with each extraction so that
2556 their saving and restoring doesn't refer to uninitialized store.
2557
2558 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2559 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2560 fix the problem.
2561
2562 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2563 calls, and wasn't printing the correct value for compiling calls. Increased the
2564 default value of LOOPREPEAT, and the number of significant figures in the
2565 times.
2566
2567 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2568
2569 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2570 a building problem on Windows NT with a FAT file system.
2571
2572
2573 Version 2.01 21-Oct-98
2574 ----------------------
2575
2576 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2577 to character tables built by pcre_maketables() in the current locale. If NULL
2578 is passed, the default tables are used.
2579
2580
2581 Version 2.00 24-Sep-98
2582 ----------------------
2583
2584 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2585 it any more.
2586
2587 2. Allow quantification of (?>) groups, and make it work correctly.
2588
2589 3. The first character computation wasn't working for (?>) groups.
2590
2591 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2592 end of the subject) and add 5.005's \z, which really does match only at the
2593 very end of the subject.
2594
2595 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2596
2597 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2598 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2599 localized options. All options to pcre_study() were also removed.
2600
2601 7. Add other new features from 5.005:
2602
2603 $(?<= positive lookbehind
2604 $(?<! negative lookbehind
2605 (?imsx-imsx) added the unsetting capability
2606 such a setting is global if at outer level; local otherwise
2607 (?imsx-imsx:) non-capturing groups with option setting
2608 (?(cond)re|re) conditional pattern matching
2609
2610 A backreference to itself in a repeated group matches the previous
2611 captured string.
2612
2613 8. General tidying up of studying (both automatic and via "study")
2614 consequential on the addition of new assertions.
2615
2616 9. As in 5.005, unlimited repeated groups that could match an empty substring
2617 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2618 runtime if any iteration does actually match an empty substring.
2619
2620 10. Include the RunTest script in the distribution.
2621
2622 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2623 discrepancies, some of which were old and were also with respect to 5.004. They
2624 have now been fixed.
2625
2626
2627 Version 1.09 28-Apr-98
2628 ----------------------
2629
2630 1. A negated single character class followed by a quantifier with a minimum
2631 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2632 program crashes, or just wrong answers. This did not apply to negated classes
2633 containing more than one character, or to minima other than one.
2634
2635
2636 Version 1.08 27-Mar-98
2637 ----------------------
2638
2639 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2640
2641 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2642 latter must appear before anything that relies on it in the pattern.
2643
2644
2645 Version 1.07 16-Feb-98
2646 ----------------------
2647
2648 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2649 repeat of a potentially empty string).
2650
2651
2652 Version 1.06 23-Jan-98
2653 ----------------------
2654
2655 1. Added Markus Oberhumer's little patches for C++.
2656
2657 2. Literal strings longer than 255 characters were broken.
2658
2659
2660 Version 1.05 23-Dec-97
2661 ----------------------
2662
2663 1. Negated character classes containing more than one character were failing if
2664 PCRE_CASELESS was set at run time.
2665
2666
2667 Version 1.04 19-Dec-97
2668 ----------------------
2669
2670 1. Corrected the man page, where some "const" qualifiers had been omitted.
2671
2672 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2673 input syntax.
2674
2675 3. Fixed memory leak which occurred when a regex with back references was
2676 matched with an offsets vector that wasn't big enough. The temporary memory
2677 that is used in this case wasn't being freed if the match failed.
2678
2679 4. Tidied pcretest to ensure it frees memory that it gets.
2680
2681 5. Temporary memory was being obtained in the case where the passed offsets
2682 vector was exactly big enough.
2683
2684 6. Corrected definition of offsetof() from change 5 below.
2685
2686 7. I had screwed up change 6 below and broken the rules for the use of
2687 setjmp(). Now fixed.
2688
2689
2690 Version 1.03 18-Dec-97
2691 ----------------------
2692
2693 1. A erroneous regex with a missing opening parenthesis was correctly
2694 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2695 on some systems.
2696
2697 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2698 it was reported that one broken compiler failed on the former because "code" is
2699 also an independent variable.
2700
2701 3. The erroneous regex a[]b caused an array overrun reference.
2702
2703 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2704 fail on data ending with that character. (It was going on too far, and checking
2705 the next character, typically a binary zero.) This was specific to the
2706 optimized code for single-character negative classes.
2707
2708 5. Added a contributed patch from the TIN world which does the following:
2709
2710 + Add an undef for memmove, in case the the system defines a macro for it.
2711
2712 + Add a definition of offsetof(), in case there isn't one. (I don't know
2713 the reason behind this - offsetof() is part of the ANSI standard - but
2714 it does no harm).
2715
2716 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2717 most of the places where whitespace preceded '#'. I have given up and
2718 allowed the remaining 2 cases to be at the margin.
2719
2720 + Rename some variables in pcre to eliminate shadowing. This seems very
2721 pedantic, but does no harm, of course.
2722
2723 6. Moved the call to setjmp() into its own function, to get rid of warnings
2724 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2725
2726 7. Constructs such as \d{8,} were compiling into the equivalent of
2727 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2728 outcome, but in this particular case used more store than had been allocated,
2729 which caused the bug to be discovered because it threw up an internal error.
2730
2731 8. The debugging code in both pcre and pcretest for outputting the compiled
2732 form of a regex was going wrong in the case of back references followed by
2733 curly-bracketed repeats.
2734
2735
2736 Version 1.02 12-Dec-97
2737 ----------------------
2738
2739 1. Typos in pcre.3 and comments in the source fixed.
2740
2741 2. Applied a contributed patch to get rid of places where it used to remove
2742 'const' from variables, and fixed some signed/unsigned and uninitialized
2743 variable warnings.
2744
2745 3. Added the "runtest" target to Makefile.
2746
2747 4. Set default compiler flag to -O2 rather than just -O.
2748
2749
2750 Version 1.01 19-Nov-97
2751 ----------------------
2752
2753 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
2754 like /([ab]*)*/, that is, for classes with more than one character in them.
2755
2756 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
2757 as /((?>a*))*/ (a PCRE_EXTRA facility).
2758
2759
2760 Version 1.00 18-Nov-97
2761 ----------------------
2762
2763 1. Added compile-time macros to support systems such as SunOS4 which don't have
2764 memmove() or strerror() but have other things that can be used instead.
2765
2766 2. Arranged that "make clean" removes the executables.
2767
2768
2769 Version 0.99 27-Oct-97
2770 ----------------------
2771
2772 1. Fixed bug in code for optimizing classes with only one character. It was
2773 initializing a 32-byte map regardless, which could cause it to run off the end
2774 of the memory it had got.
2775
2776 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
2777
2778
2779 Version 0.98 22-Oct-97
2780 ----------------------
2781
2782 1. Fixed bug in code for handling temporary memory usage when there are more
2783 back references than supplied space in the ovector. This could cause segfaults.
2784
2785
2786 Version 0.97 21-Oct-97
2787 ----------------------
2788
2789 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
2790
2791 2. Optimized negated single characters not to use a bit map.
2792
2793 3. Brought error texts together as macro definitions; clarified some of them;
2794 fixed one that was wrong - it said "range out of order" when it meant "invalid
2795 escape sequence".
2796
2797 4. Changed some char * arguments to const char *.
2798
2799 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
2800
2801 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
2802 pcretest.
2803
2804
2805 Version 0.96 16-Oct-97
2806 ----------------------
2807
2808 1. Added a simple "pgrep" utility to the distribution.
2809
2810 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
2811 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
2812 where "ddd" means "one or more decimal digits".
2813
2814 3. Fixed serious bug. If a pattern had a back reference, but the call to
2815 pcre_exec() didn't supply a large enough ovector to record the related
2816 identifying subpattern, the match always failed. PCRE now remembers the number
2817 of the largest back reference, and gets some temporary memory in which to save
2818 the offsets during matching if necessary, in order to ensure that
2819 backreferences always work.
2820
2821 4. Increased the compatibility with Perl in a number of ways:
2822
2823 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
2824 to request this handling. The option can be set at compile or exec time.
2825
2826 (b) $ matches before a terminating newline by default; an option
2827 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
2828 mode). The option can be set at compile or exec time.
2829
2830 (c) The handling of \ followed by a digit other than 0 is now supposed to be
2831 the same as Perl's. If the decimal number it represents is less than 10
2832 or there aren't that many previous left capturing parentheses, an octal
2833 escape is read. Inside a character class, it's always an octal escape,
2834 even if it is a single digit.
2835
2836 (d) An escaped but undefined alphabetic character is taken as a literal,
2837 unless PCRE_EXTRA is set. Currently this just reserves the remaining
2838 escapes.
2839
2840 (e) {0} is now permitted. (The previous item is removed from the compiled
2841 pattern).
2842
2843 5. Changed all the names of code files so that the basic parts are no longer
2844 than 10 characters, and abolished the teeny "globals.c" file.
2845
2846 6. Changed the handling of character classes; they are now done with a 32-byte
2847 bit map always.
2848
2849 7. Added the -d and /D options to pcretest to make it possible to look at the
2850 internals of compilation without having to recompile pcre.
2851
2852
2853 Version 0.95 23-Sep-97
2854 ----------------------
2855
2856 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
2857 \x20 at the start of a run of normal characters. These were being treated as
2858 real characters, instead of the source characters being re-checked.
2859
2860
2861 Version 0.94 18-Sep-97
2862 ----------------------
2863
2864 1. The functions are now thread-safe, with the caveat that the global variables
2865 containing pointers to malloc() and free() or alternative functions are the
2866 same for all threads.
2867
2868 2. Get pcre_study() to generate a bitmap of initial characters for non-
2869 anchored patterns when this is possible, and use it if passed to pcre_exec().
2870
2871
2872 Version 0.93 15-Sep-97
2873 ----------------------
2874
2875 1. /(b)|(:+)/ was computing an incorrect first character.
2876
2877 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
2878 but not actually doing anything yet.
2879
2880 3. Treat "-" characters in classes that cannot be part of ranges as literals,
2881 as Perl does (e.g. [-az] or [az-]).
2882
2883 4. Set the anchored flag if a branch starts with .* or .*? because that tests
2884 all possible positions.
2885
2886 5. Split up into different modules to avoid including unneeded functions in a
2887 compiled binary. However, compile and exec are still in one module. The "study"
2888 function is split off.
2889
2890 6. The character tables are now in a separate module whose source is generated
2891 by an auxiliary program - but can then be edited by hand if required. There are
2892 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
2893 toupper() in the code.
2894
2895 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
2896 make them global. Abolish the function for setting them, as the caller can now
2897 set them directly.
2898
2899
2900 Version 0.92 11-Sep-97
2901 ----------------------
2902
2903 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
2904 (e.g. /a{1,3}/) was broken (I mis-optimized it).
2905
2906 2. Caseless matching was not working in character classes if the characters in
2907 the pattern were in upper case.
2908
2909 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
2910
2911 4. Make PCRE_ANCHORED public and accept as a compile option.
2912
2913 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
2914 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
2915 pass them.
2916
2917 6. Give an error if bad option bits passed at compile or run time.
2918
2919 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
2920 pcretest to cause it to pass that flag.
2921
2922 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
2923 options, and the first character, if set.
2924
2925 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
2926
2927
2928 Version 0.91 10-Sep-97
2929 ----------------------
2930
2931 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
2932 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
2933
2934 2. PCRE was looping on encountering an indefinitely repeated back reference to
2935 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
2936 Perl does - treats the match as successful.
2937
2938 ****

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