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Revision 311 - (show annotations) (download)
Wed Jan 23 17:34:58 2008 UTC (6 years, 3 months ago) by ph10
File size: 150002 byte(s)
Applied Sheri's patch to CMakeLists.txt to add library name options and correct 
the recursion comment.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.6 21-Jan-08
5 ---------------------
6
7 1. A character class containing a very large number of characters with
8 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
9 overflow.
10
11 2. Patch to cut out the "long long" test in pcrecpp_unittest when
12 HAVE_LONG_LONG is not defined.
13
14 3. Applied Christian Ehrlicher's patch to update the CMake build files to
15 bring them up to date and include new features. This patch includes:
16
17 - Fixed PH's badly added libz and libbz2 support.
18 - Fixed a problem with static linking.
19 - Added pcredemo.
20 - Fixed dftables problem and added an option.
21 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
22 HAVE_LONG_LONG.
23 - Added readline support for pcretest.
24 - Added an listing of the option settings after cmake has run.
25
26 4. A user submitted a patch to Makefile that makes it easy to created a dll
27 under mingw. I added stuff to Makefile.am that cause it to include this
28 special target, without affecting anything else.
29
30 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
31 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
32 exported in the Windows port". It has not yet been confirmed that the patch
33 solves the problem, but it does no harm.
34
35 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
36 NON_STANDARD_LIB_SUFFIX and correct the comment about stack recursion.
37
38
39 Version 7.5 10-Jan-08
40 ---------------------
41
42 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
43 values in parens when parsing an RE using the C++ wrapper."
44
45 2. Negative specials like \S did not work in character classes in UTF-8 mode.
46 Characters greater than 255 were excluded from the class instead of being
47 included.
48
49 3. The same bug as (2) above applied to negated POSIX classes such as
50 [:^space:].
51
52 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
53 defined or documented. It seems to have been a typo for PCRE_STATIC, so
54 I have changed it.
55
56 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
57 first named subpattern) and a construct such as (?&a) would reference the
58 first named subpattern whose name started with "a" (in other words, the
59 length check was missing). Both these problems are fixed. "Subpattern name
60 expected" is now given for (?&) (a zero-length name), and this patch also
61 makes it give the same error for \k'' (previously it complained that that
62 was a reference to a non-existent subpattern).
63
64 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
65 this is right because (?- can be followed by option settings as well as by
66 digits. I have, however, made the messages clearer.
67
68 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
69 than the number used in the conditional) now cause a compile-time error.
70 This is actually not compatible with Perl, which accepts such patterns, but
71 treats the conditional as always being FALSE (as PCRE used to), but it
72 seems to me that giving a diagnostic is better.
73
74 8. Change "alphameric" to the more common word "alphanumeric" in comments
75 and messages.
76
77 9. Fix two occurrences of "backslash" in comments that should have been
78 "backspace".
79
80 10. Remove two redundant lines of code that can never be obeyed (their function
81 was moved elsewhere).
82
83 11. The program that makes PCRE's Unicode character property table had a bug
84 which caused it to generate incorrect table entries for sequences of
85 characters that have the same character type, but are in different scripts.
86 It amalgamated them into a single range, with the script of the first of
87 them. In other words, some characters were in the wrong script. There were
88 thirteen such cases, affecting characters in the following ranges:
89
90 U+002b0 - U+002c1
91 U+0060c - U+0060d
92 U+0061e - U+00612
93 U+0064b - U+0065e
94 U+0074d - U+0076d
95 U+01800 - U+01805
96 U+01d00 - U+01d77
97 U+01d9b - U+01dbf
98 U+0200b - U+0200f
99 U+030fc - U+030fe
100 U+03260 - U+0327f
101 U+0fb46 - U+0fbb1
102 U+10450 - U+1049d
103
104 12. The -o option (show only the matching part of a line) for pcregrep was not
105 compatible with GNU grep in that, if there was more than one match in a
106 line, it showed only the first of them. It now behaves in the same way as
107 GNU grep.
108
109 13. If the -o and -v options were combined for pcregrep, it printed a blank
110 line for every non-matching line. GNU grep prints nothing, and pcregrep now
111 does the same. The return code can be used to tell if there were any
112 non-matching lines.
113
114 14. Added --file-offsets and --line-offsets to pcregrep.
115
116 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
117 infinitely looping recursion. The bug was that positive lookaheads were not
118 being skipped when checking for a possible empty match (negative lookaheads
119 and both kinds of lookbehind were skipped).
120
121 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
122 inclusion of <windows.h> to before rather than after the definition of
123 INVALID_FILE_ATTRIBUTES (patch from David Byron).
124
125 17. Specifying a possessive quantifier with a specific limit for a Unicode
126 character property caused pcre_compile() to compile bad code, which led at
127 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
128 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
129 caused the error; without that there was no problem.
130
131 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
132
133 19. Added --enable-pcretest-libreadline.
134
135 20. In pcrecpp.cc, the variable 'count' was incremented twice in
136 RE::GlobalReplace(). As a result, the number of replacements returned was
137 double what it should be. I removed one of the increments, but Craig sent a
138 later patch that removed the other one (the right fix) and added unit tests
139 that check the return values (which was not done before).
140
141 21. Several CMake things:
142
143 (1) Arranged that, when cmake is used on Unix, the libraries end up with
144 the names libpcre and libpcreposix, not just pcre and pcreposix.
145
146 (2) The above change means that pcretest and pcregrep are now correctly
147 linked with the newly-built libraries, not previously installed ones.
148
149 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
150
151 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
152 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
153 UTF-8 newline character). The key issue is that the pattern starts .*;
154 this means that the match must be either at the beginning, or after a
155 newline. The bug was in the code for advancing after a failed match and
156 checking that the new position followed a newline. It was not taking
157 account of UTF-8 characters correctly.
158
159 23. PCRE was behaving differently from Perl in the way it recognized POSIX
160 character classes. PCRE was not treating the sequence [:...:] as a
161 character class unless the ... were all letters. Perl, however, seems to
162 allow any characters between [: and :], though of course it rejects as
163 unknown any "names" that contain non-letters, because all the known class
164 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
165 for example, whereas PCRE did not - it did not recognize a POSIX character
166 class. This seemed a bit dangerous, so the code has been changed to be
167 closer to Perl. The behaviour is not identical to Perl, because PCRE will
168 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
169 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
170 Perl does, and where it didn't before.
171
172 24. Rewrite so as to remove the single use of %n from pcregrep because in some
173 Windows environments %n is disabled by default.
174
175
176 Version 7.4 21-Sep-07
177 ---------------------
178
179 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
180 means that a class such as [\s] counted as "explicit reference to CR or
181 LF". That isn't really right - the whole point of the change was to try to
182 help when there was an actual mention of one of the two characters. So now
183 the change happens only if \r or \n (or a literal CR or LF) character is
184 encountered.
185
186 2. The 32-bit options word was also used for 6 internal flags, but the numbers
187 of both had grown to the point where there were only 3 bits left.
188 Fortunately, there was spare space in the data structure, and so I have
189 moved the internal flags into a new 16-bit field to free up more option
190 bits.
191
192 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
193 but did not set the internal JCHANGED flag - either of these is enough to
194 control the way the "get" function works - but the PCRE_INFO_JCHANGED
195 facility is supposed to tell if (?J) was ever used, so now (?J) at the
196 start sets both bits.
197
198 4. Added options (at build time, compile time, exec time) to change \R from
199 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
200
201 5. doc/pcresyntax.html was missing from the distribution.
202
203 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
204 compatibility, even though it is no longer used.
205
206 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
207 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
208 windows.h file is present (where different names are used). [This was
209 reversed later after testing - see 16 below.]
210
211 8. Changed all #include <config.h> to #include "config.h". There were also
212 some further <pcre.h> cases that I changed to "pcre.h".
213
214 9. When pcregrep was used with the --colour option, it missed the line ending
215 sequence off the lines that it output.
216
217 10. It was pointed out to me that arrays of string pointers cause lots of
218 relocations when a shared library is dynamically loaded. A technique of
219 using a single long string with a table of offsets can drastically reduce
220 these. I have refactored PCRE in four places to do this. The result is
221 dramatic:
222
223 Originally: 290
224 After changing UCP table: 187
225 After changing error message table: 43
226 After changing table of "verbs" 36
227 After changing table of Posix names 22
228
229 Thanks to the folks working on Gregex for glib for this insight.
230
231 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
232 unicode-properties was also set.
233
234 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
235
236 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
237 checked only for CRLF.
238
239 14. Added casts to pcretest.c to avoid compiler warnings.
240
241 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
242
243 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
244 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
245 entirely. This removes changes made in 7 above.
246
247 17. The CMake files have been updated, and there is now more information about
248 building with CMake in the NON-UNIX-USE document.
249
250
251 Version 7.3 28-Aug-07
252 ---------------------
253
254 1. In the rejigging of the build system that eventually resulted in 7.1, the
255 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
256 brackets there is not right, since it causes compilers to look for an
257 installed pcre.h, not the version that is in the source that is being
258 compiled (which of course may be different). I have changed it back to:
259
260 #include "pcre.h"
261
262 I have a vague recollection that the change was concerned with compiling in
263 different directories, but in the new build system, that is taken care of
264 by the VPATH setting the Makefile.
265
266 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
267 when the subject happened to end in the byte 0x85 (e.g. if the last
268 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
269 characters but of course it shouldn't be taken as a newline when it is part
270 of another character. The bug was that, for an unlimited repeat of . in
271 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
272 characters when looking for a newline.
273
274 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
275
276 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
277 in debug output.
278
279 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
280 long printing in the pcrecpp unittest when running under MinGW.
281
282 6. ESC_K was left out of the EBCDIC table.
283
284 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
285 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
286 limit also applies to "virtual nesting" when a pattern is recursive, and in
287 this case 1000 isn't so big. I have been able to remove this limit at the
288 expense of backing off one optimization in certain circumstances. Normally,
289 when pcre_exec() would call its internal match() function recursively and
290 immediately return the result unconditionally, it uses a "tail recursion"
291 feature to save stack. However, when a subpattern that can match an empty
292 string has an unlimited repetition quantifier, it no longer makes this
293 optimization. That gives it a stack frame in which to save the data for
294 checking that an empty string has been matched. Previously this was taken
295 from the 1000-entry workspace that had been reserved. So now there is no
296 explicit limit, but more stack is used.
297
298 8. Applied Daniel's patches to solve problems with the import/export magic
299 syntax that is required for Windows, and which was going wrong for the
300 pcreposix and pcrecpp parts of the library. These were overlooked when this
301 problem was solved for the main library.
302
303 9. There were some crude static tests to avoid integer overflow when computing
304 the size of patterns that contain repeated groups with explicit upper
305 limits. As the maximum quantifier is 65535, the maximum group length was
306 set at 30,000 so that the product of these two numbers did not overflow a
307 32-bit integer. However, it turns out that people want to use groups that
308 are longer than 30,000 bytes (though not repeat them that many times).
309 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
310 made it possible to implement the integer overflow checks in a much more
311 dynamic way, which I have now done. The artificial limitation on group
312 length has been removed - we now have only the limit on the total length of
313 the compiled pattern, which depends on the LINK_SIZE setting.
314
315 10. Fixed a bug in the documentation for get/copy named substring when
316 duplicate names are permitted. If none of the named substrings are set, the
317 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
318 empty string.
319
320 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
321 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
322 because the ] is interpreted as the first data character and the
323 terminating ] is not found. PCRE has been made compatible with Perl in this
324 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
325 cause memory overwriting.
326
327 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
328 string has been matched (to stop an infinite loop). It was not recognizing
329 a conditional subpattern that could match an empty string if that
330 subpattern was within another subpattern. For example, it looped when
331 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
332 condition was not nested. This bug has been fixed.
333
334 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
335 past the start of the subject in the presence of bytes with the top bit
336 set, for example "\x8aBCD".
337
338 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
339 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
340
341 14. Optimized (?!) to (*FAIL).
342
343 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
344 This restricts code points to be within the range 0 to 0x10FFFF, excluding
345 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
346 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
347 does: it's just the validity check that is more restrictive.
348
349 16. Inserted checks for integer overflows during escape sequence (backslash)
350 processing, and also fixed erroneous offset values for syntax errors during
351 backslash processing.
352
353 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
354 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
355
356 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
357 caused an overrun.
358
359 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
360 something other than just ASCII characters) inside a group that had an
361 unlimited repeat caused a loop at compile time (while checking to see
362 whether the group could match an empty string).
363
364 20. Debugging a pattern containing \p or \P could cause a crash. For example,
365 [\P{Any}] did so. (Error in the code for printing property names.)
366
367 21. An orphan \E inside a character class could cause a crash.
368
369 22. A repeated capturing bracket such as (A)? could cause a wild memory
370 reference during compilation.
371
372 23. There are several functions in pcre_compile() that scan along a compiled
373 expression for various reasons (e.g. to see if it's fixed length for look
374 behind). There were bugs in these functions when a repeated \p or \P was
375 present in the pattern. These operators have additional parameters compared
376 with \d, etc, and these were not being taken into account when moving along
377 the compiled data. Specifically:
378
379 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
380 length.
381
382 (b) An item such as \pL+ within a repeated group could cause crashes or
383 loops.
384
385 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
386 "reference to non-existent subpattern" error.
387
388 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
389
390 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
391 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
392
393 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
394
395 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
396 character were causing crashes (broken optimization).
397
398 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
399 \p or \P) caused a compile-time loop.
400
401 28. More problems have arisen in unanchored patterns when CRLF is a valid line
402 break. For example, the unstudied pattern [\r\n]A does not match the string
403 "\r\nA" because change 7.0/46 below moves the current point on by two
404 characters after failing to match at the start. However, the pattern \nA
405 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
406 the same is true. There doesn't seem any very clean way out of this, but
407 what I have chosen to do makes the common cases work: PCRE now takes note
408 of whether there can be an explicit match for \r or \n anywhere in the
409 pattern, and if so, 7.0/46 no longer applies. As part of this change,
410 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
411 pattern has explicit CR or LF references.
412
413 29. Added (*CR) etc for changing newline setting at start of pattern.
414
415
416 Version 7.2 19-Jun-07
417 ---------------------
418
419 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
420 which is apparently normally available under Windows.
421
422 2. Re-jig the pcregrep tests with different newline settings in an attempt
423 to make them independent of the local environment's newline setting.
424
425 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
426
427 4. Some of the "internals" tests were previously cut out when the link size
428 was not 2, because the output contained actual offsets. The recent new
429 "Z" feature of pcretest means that these can be cut out, making the tests
430 usable with all link sizes.
431
432 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
433 stack recursion. This gives a massive performance boost under BSD, but just
434 a small improvement under Linux. However, it saves one field in the frame
435 in all cases.
436
437 6. Added more features from the forthcoming Perl 5.10:
438
439 (a) (?-n) (where n is a string of digits) is a relative subroutine or
440 recursion call. It refers to the nth most recently opened parentheses.
441
442 (b) (?+n) is also a relative subroutine call; it refers to the nth next
443 to be opened parentheses.
444
445 (c) Conditions that refer to capturing parentheses can be specified
446 relatively, for example, (?(-2)... or (?(+3)...
447
448 (d) \K resets the start of the current match so that everything before
449 is not part of it.
450
451 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
452
453 (f) \g{name} is another synonym - part of Perl 5.10's unification of
454 reference syntax.
455
456 (g) (?| introduces a group in which the numbering of parentheses in each
457 alternative starts with the same number.
458
459 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
460
461 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
462 PCRE_INFO_JCHANGED.
463
464 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
465 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
466 for detecting groups that can match an empty string.
467
468 9. A pattern with a very large number of alternatives (more than several
469 hundred) was running out of internal workspace during the pre-compile
470 phase, where pcre_compile() figures out how much memory will be needed. A
471 bit of new cunning has reduced the workspace needed for groups with
472 alternatives. The 1000-alternative test pattern now uses 12 bytes of
473 workspace instead of running out of the 4096 that are available.
474
475 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
476
477 11. Applied patch from Google to remove an optimization that didn't quite work.
478 The report of the bug said:
479
480 pcrecpp::RE("a*").FullMatch("aaa") matches, while
481 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
482 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
483
484 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
485 it matched the wrong number of bytes.
486
487
488 Version 7.1 24-Apr-07
489 ---------------------
490
491 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
492 that is more "standard", making use of automake and other Autotools. There
493 is some re-arrangement of the files and adjustment of comments consequent
494 on this.
495
496 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
497 for recursive directory scanning broke on some systems because the files
498 are not scanned in any specific order and on different systems the order
499 was different. A call to "sort" has been inserted into RunGrepTest for the
500 approprate test as a short-term fix. In the longer term there may be an
501 alternative.
502
503 3. I had an email from Eric Raymond about problems translating some of PCRE's
504 man pages to HTML (despite the fact that I distribute HTML pages, some
505 people do their own conversions for various reasons). The problems
506 concerned the use of low-level troff macros .br and .in. I have therefore
507 removed all such uses from the man pages (some were redundant, some could
508 be replaced by .nf/.fi pairs). The 132html script that I use to generate
509 HTML has been updated to handle .nf/.fi and to complain if it encounters
510 .br or .in.
511
512 4. Updated comments in configure.ac that get placed in config.h.in and also
513 arranged for config.h to be included in the distribution, with the name
514 config.h.generic, for the benefit of those who have to compile without
515 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
516
517 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
518 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
519 makevp.bat for the current PCRE, using the additional files
520 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
521
522 6. A Windows user reported a minor discrepancy with test 2, which turned out
523 to be caused by a trailing space on an input line that had got lost in his
524 copy. The trailing space was an accident, so I've just removed it.
525
526 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
527 that is needed.
528
529 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
530 as "const" (a) because they are and (b) because it helps the PHP
531 maintainers who have recently made a script to detect big data structures
532 in the php code that should be moved to the .rodata section. I remembered
533 to update Builducptable as well, so it won't revert if ucptable.h is ever
534 re-created.
535
536 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
537 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
538 order to be able to cut out the UTF-8 tables in the latter when UTF-8
539 support is not required. This saves 1.5-2K of code, which is important in
540 some applications.
541
542 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
543 so as not to refer to the tables, even though these functions will never be
544 called when UTF-8 support is disabled. Otherwise there are problems with a
545 shared library.
546
547 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
548
549 (a) It was defining its arguments as char * instead of void *.
550
551 (b) It was assuming that all moves were upwards in memory; this was true
552 a long time ago when I wrote it, but is no longer the case.
553
554 The emulated memove() is provided for those environments that have neither
555 memmove() nor bcopy(). I didn't think anyone used it these days, but that
556 is clearly not the case, as these two bugs were recently reported.
557
558 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
559 and Detrail to create the HTML documentation, the .txt form of the man
560 pages, and it removes trailing spaces from listed files. It also creates
561 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
562 case, it wraps all the #defines with #ifndefs. This script should be run
563 before "make dist".
564
565 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
566 with Unicode property support.
567
568 (a) For a maximizing quantifier, if the two different cases of the
569 character were of different lengths in their UTF-8 codings (there are
570 some cases like this - I found 11), and the matching function had to
571 back up over a mixture of the two cases, it incorrectly assumed they
572 were both the same length.
573
574 (b) When PCRE was configured to use the heap rather than the stack for
575 recursion during matching, it was not correctly preserving the data for
576 the other case of a UTF-8 character when checking ahead for a match
577 while processing a minimizing repeat. If the check also involved
578 matching a wide character, but failed, corruption could cause an
579 erroneous result when trying to check for a repeat of the original
580 character.
581
582 13. Some tidying changes to the testing mechanism:
583
584 (a) The RunTest script now detects the internal link size and whether there
585 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
586 values substituted by "configure". (The RunGrepTest script already did
587 this for UTF-8.) The configure.ac script no longer substitutes the
588 relevant variables.
589
590 (b) The debugging options /B and /D in pcretest show the compiled bytecode
591 with length and offset values. This means that the output is different
592 for different internal link sizes. Test 2 is skipped for link sizes
593 other than 2 because of this, bypassing the problem. Unfortunately,
594 there was also a test in test 3 (the locale tests) that used /B and
595 failed for link sizes other than 2. Rather than cut the whole test out,
596 I have added a new /Z option to pcretest that replaces the length and
597 offset values with spaces. This is now used to make test 3 independent
598 of link size. (Test 2 will be tidied up later.)
599
600 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
601 segmentation fault instead of returning the appropriate error message.
602
603 15. In multiline mode when the newline sequence was set to "any", the pattern
604 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
605 This doesn't seem right; it now treats the CRLF combination as the line
606 ending, and so does not match in that case. It's only a pattern such as ^$
607 that would hit this one: something like ^ABC$ would have failed after \r
608 and then tried again after \r\n.
609
610 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
611 in an attempt to make files that differ only in their line terminators
612 compare equal. This works on Linux.
613
614 17. Under certain error circumstances pcregrep might try to free random memory
615 as it exited. This is now fixed, thanks to valgrind.
616
617 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
618 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
619 was because its rules for how to advance for /g after matching an empty
620 string at the end of a line did not allow for this case. They now check for
621 it specially.
622
623 20. pcretest is supposed to handle patterns and data of any length, by
624 extending its buffers when necessary. It was getting this wrong when the
625 buffer for a data line had to be extended.
626
627 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
628 CRLF as a newline sequence.
629
630 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
631 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
632 I have nevertheless tidied it up.
633
634 23. Added some casts to kill warnings from HP-UX ia64 compiler.
635
636 24. Added a man page for pcre-config.
637
638
639 Version 7.0 19-Dec-06
640 ---------------------
641
642 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
643 moving to gcc 4.1.1.
644
645 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
646 sys/time.h, which is documented as needed for this function. It doesn't
647 seem to matter on Linux, but it showed up on some releases of OS X.
648
649 3. It seems that there are systems where bytes whose values are greater than
650 127 match isprint() in the "C" locale. The "C" locale should be the
651 default when a C program starts up. In most systems, only ASCII printing
652 characters match isprint(). This difference caused the output from pcretest
653 to vary, making some of the tests fail. I have changed pcretest so that:
654
655 (a) When it is outputting text in the compiled version of a pattern, bytes
656 other than 32-126 are always shown as hex escapes.
657
658 (b) When it is outputting text that is a matched part of a subject string,
659 it does the same, unless a different locale has been set for the match
660 (using the /L modifier). In this case, it uses isprint() to decide.
661
662 4. Fixed a major bug that caused incorrect computation of the amount of memory
663 required for a compiled pattern when options that changed within the
664 pattern affected the logic of the preliminary scan that determines the
665 length. The relevant options are -x, and -i in UTF-8 mode. The result was
666 that the computed length was too small. The symptoms of this bug were
667 either the PCRE error "internal error: code overflow" from pcre_compile(),
668 or a glibc crash with a message such as "pcretest: free(): invalid next
669 size (fast)". Examples of patterns that provoked this bug (shown in
670 pcretest format) are:
671
672 /(?-x: )/x
673 /(?x)(?-x: \s*#\s*)/
674 /((?i)[\x{c0}])/8
675 /(?i:[\x{c0}])/8
676
677 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
678 is now done differently.
679
680 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
681 wrapper classes; (b) implement a new function in the C++ scanner that is
682 more efficient than the old way of doing things because it avoids levels of
683 recursion in the regex matching; (c) add a paragraph to the documentation
684 for the FullMatch() function.
685
686 6. The escape sequence \n was being treated as whatever was defined as
687 "newline". Not only was this contrary to the documentation, which states
688 that \n is character 10 (hex 0A), but it also went horribly wrong when
689 "newline" was defined as CRLF. This has been fixed.
690
691 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
692 was being set to -1 for the "end of line" case (supposedly a value that no
693 character can have). Though this value is never used (the check for end of
694 line is "zero bytes in current character"), it caused compiler complaints.
695 I've changed it to 0xffffffff.
696
697 8. In pcre_version.c, the version string was being built by a sequence of
698 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
699 string (as it is for production releases) called a macro with an empty
700 argument. The C standard says the result of this is undefined. The gcc
701 compiler treats it as an empty string (which was what was wanted) but it is
702 reported that Visual C gives an error. The source has been hacked around to
703 avoid this problem.
704
705 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
706 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
707 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
708 of them did).
709
710 10. Originally, pcretest opened its input and output without "b"; then I was
711 told that "b" was needed in some environments, so it was added for release
712 5.0 to both the input and output. (It makes no difference on Unix-like
713 systems.) Later I was told that it is wrong for the input on Windows. I've
714 now abstracted the modes into two macros, to make it easier to fiddle with
715 them, and removed "b" from the input mode under Windows.
716
717 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
718
719 12. Added -help and --help to pcretest as an official way of being reminded
720 of the options.
721
722 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
723 and pcrecpp.cc because they annoy compilers at high warning levels.
724
725 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
726
727 15. Fixed an occurrence of == in configure.ac that should have been = (shell
728 scripts are not C programs :-) and which was not noticed because it works
729 on Linux.
730
731 16. pcretest is supposed to handle any length of pattern and data line (as one
732 line or as a continued sequence of lines) by extending its input buffer if
733 necessary. This feature was broken for very long pattern lines, leading to
734 a string of junk being passed to pcre_compile() if the pattern was longer
735 than about 50K.
736
737 17. I have done a major re-factoring of the way pcre_compile() computes the
738 amount of memory needed for a compiled pattern. Previously, there was code
739 that made a preliminary scan of the pattern in order to do this. That was
740 OK when PCRE was new, but as the facilities have expanded, it has become
741 harder and harder to keep it in step with the real compile phase, and there
742 have been a number of bugs (see for example, 4 above). I have now found a
743 cunning way of running the real compile function in a "fake" mode that
744 enables it to compute how much memory it would need, while actually only
745 ever using a few hundred bytes of working memory and without too many
746 tests of the mode. This should make future maintenance and development
747 easier. A side effect of this work is that the limit of 200 on the nesting
748 depth of parentheses has been removed (though this was never a serious
749 limitation, I suspect). However, there is a downside: pcre_compile() now
750 runs more slowly than before (30% or more, depending on the pattern). I
751 hope this isn't a big issue. There is no effect on runtime performance.
752
753 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
754 newline (only possible for the last line of a file) and it was a
755 pattern that set a locale (followed by /Lsomething), pcretest crashed.
756
757 19. Added additional timing features to pcretest. (1) The -tm option now times
758 matching only, not compiling. (2) Both -t and -tm can be followed, as a
759 separate command line item, by a number that specifies the number of
760 repeats to use when timing. The default is 50000; this gives better
761 precision, but takes uncomfortably long for very large patterns.
762
763 20. Extended pcre_study() to be more clever in cases where a branch of a
764 subpattern has no definite first character. For example, (a*|b*)[cd] would
765 previously give no result from pcre_study(). Now it recognizes that the
766 first character must be a, b, c, or d.
767
768 21. There was an incorrect error "recursive call could loop indefinitely" if
769 a subpattern (or the entire pattern) that was being tested for matching an
770 empty string contained only one non-empty item after a nested subpattern.
771 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
772 incorrectly, because the \d was being skipped in the check.
773
774 22. The pcretest program now has a new pattern option /B and a command line
775 option -b, which is equivalent to adding /B to every pattern. This causes
776 it to show the compiled bytecode, without the additional information that
777 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
778 is the same as /B/I).
779
780 23. A new optimization is now able automatically to treat some sequences such
781 as a*b as a*+b. More specifically, if something simple (such as a character
782 or a simple class like \d) has an unlimited quantifier, and is followed by
783 something that cannot possibly match the quantified thing, the quantifier
784 is automatically "possessified".
785
786 24. A recursive reference to a subpattern whose number was greater than 39
787 went wrong under certain circumstances in UTF-8 mode. This bug could also
788 have affected the operation of pcre_study().
789
790 25. Realized that a little bit of performance could be had by replacing
791 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
792
793 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
794
795 27. Possessive quantifiers such as a++ were previously implemented by turning
796 them into atomic groups such as ($>a+). Now they have their own opcodes,
797 which improves performance. This includes the automatically created ones
798 from 23 above.
799
800 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
801 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
802 the first matched character to be a colon. This applied both to named and
803 numbered groups.
804
805 29. The ucpinternal.h header file was missing its idempotency #ifdef.
806
807 30. I was sent a "project" file called libpcre.a.dev which I understand makes
808 building PCRE on Windows easier, so I have included it in the distribution.
809
810 31. There is now a check in pcretest against a ridiculously large number being
811 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
812 loop, the loop is abandoned.
813
814 32. Forward references to subpatterns in conditions such as (?(2)...) where
815 subpattern 2 is defined later cause pcre_compile() to search forwards in
816 the pattern for the relevant set of parentheses. This search went wrong
817 when there were unescaped parentheses in a character class, parentheses
818 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
819
820 33. "Subroutine" calls and backreferences were previously restricted to
821 referencing subpatterns earlier in the regex. This restriction has now
822 been removed.
823
824 34. Added a number of extra features that are going to be in Perl 5.10. On the
825 whole, these are just syntactic alternatives for features that PCRE had
826 previously implemented using the Python syntax or my own invention. The
827 other formats are all retained for compatibility.
828
829 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
830 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
831 also .NET compatible.
832
833 (b) A recursion or subroutine call to a named group can now be defined as
834 (?&name) as well as (?P>name).
835
836 (c) A backreference to a named group can now be defined as \k<name> or
837 \k'name' as well as (?P=name). The new forms, as well as being in Perl
838 5.10, are also .NET compatible.
839
840 (d) A conditional reference to a named group can now use the syntax
841 (?(<name>) or (?('name') as well as (?(name).
842
843 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
844 groups (named and numbered) that are never evaluated inline, but can be
845 called as "subroutines" from elsewhere. In effect, the DEFINE condition
846 is always false. There may be only one alternative in such a group.
847
848 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
849 as the simple (?(R). The condition is true only if the most recent
850 recursion is that of the given number or name. It does not search out
851 through the entire recursion stack.
852
853 (g) The escape \gN or \g{N} has been added, where N is a positive or
854 negative number, specifying an absolute or relative reference.
855
856 35. Tidied to get rid of some further signed/unsigned compiler warnings and
857 some "unreachable code" warnings.
858
859 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
860 things, this adds five new scripts.
861
862 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
863 There were also incompatibilities regarding the handling of \Q..\E inside
864 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
865 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
866
867 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
868 matches an empty string, and forcibly breaks the loop. There were bugs in
869 this code in non-simple cases. For a pattern such as ^(a()*)* matched
870 against aaaa the result was just "a" rather than "aaaa", for example. Two
871 separate and independent bugs (that affected different cases) have been
872 fixed.
873
874 39. Refactored the code to abolish the use of different opcodes for small
875 capturing bracket numbers. This is a tidy that I avoided doing when I
876 removed the limit on the number of capturing brackets for 3.5 back in 2001.
877 The new approach is not only tidier, it makes it possible to reduce the
878 memory needed to fix the previous bug (38).
879
880 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
881 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
882 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
883 mode.
884
885 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
886 report.
887
888 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
889 copy construction and assignment in the C++ wrapper.
890
891 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
892 couple of bugs that could have given wrong results in the "--newline=crlf"
893 case.
894
895 44. Added a number of casts and did some reorganization of signed/unsigned int
896 variables following suggestions from Dair Grant. Also renamed the variable
897 "this" as "item" because it is a C++ keyword.
898
899 45. Arranged for dftables to add
900
901 #include "pcre_internal.h"
902
903 to pcre_chartables.c because without it, gcc 4.x may remove the array
904 definition from the final binary if PCRE is built into a static library and
905 dead code stripping is activated.
906
907 46. For an unanchored pattern, if a match attempt fails at the start of a
908 newline sequence, and the newline setting is CRLF or ANY, and the next two
909 characters are CRLF, advance by two characters instead of one.
910
911
912 Version 6.7 04-Jul-06
913 ---------------------
914
915 1. In order to handle tests when input lines are enormously long, pcretest has
916 been re-factored so that it automatically extends its buffers when
917 necessary. The code is crude, but this _is_ just a test program. The
918 default size has been increased from 32K to 50K.
919
920 2. The code in pcre_study() was using the value of the re argument before
921 testing it for NULL. (Of course, in any sensible call of the function, it
922 won't be NULL.)
923
924 3. The memmove() emulation function in pcre_internal.h, which is used on
925 systems that lack both memmove() and bcopy() - that is, hardly ever -
926 was missing a "static" storage class specifier.
927
928 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
929 containing an extended class (one that cannot be represented by a bitmap
930 because it contains high-valued characters or Unicode property items, e.g.
931 [\pZ]). Almost always one would set UTF-8 mode when processing such a
932 pattern, but PCRE should not loop if you do not (it no longer does).
933 [Detail: two cases were found: (a) a repeated subpattern containing an
934 extended class; (b) a recursive reference to a subpattern that followed a
935 previous extended class. It wasn't skipping over the extended class
936 correctly when UTF-8 mode was not set.]
937
938 5. A negated single-character class was not being recognized as fixed-length
939 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
940 compile error "lookbehind assertion is not fixed length".
941
942 6. The RunPerlTest auxiliary script was showing an unexpected difference
943 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
944 write a Perl script that can interpret lines of an input file either as
945 byte characters or as UTF-8, which is what "perltest" was being required to
946 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
947 can't do is switch easily at run time between having the "use utf8;" pragma
948 or not. In the end, I fudged it by using the RunPerlTest script to insert
949 "use utf8;" explicitly for the UTF-8 tests.
950
951 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
952 the end of the subject string, contrary to the documentation and to what
953 Perl does. This was true of both matching functions. Now it matches only at
954 the start of the subject and immediately after *internal* newlines.
955
956 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
957 a pointer to an int instead of a pointer to an unsigned long int. This
958 caused problems on 64-bit systems.
959
960 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
961 instance of the 'standard' template library not being so standard".
962
963 10. There was no check on the number of named subpatterns nor the maximum
964 length of a subpattern name. The product of these values is used to compute
965 the size of the memory block for a compiled pattern. By supplying a very
966 long subpattern name and a large number of named subpatterns, the size
967 computation could be caused to overflow. This is now prevented by limiting
968 the length of names to 32 characters, and the number of named subpatterns
969 to 10,000.
970
971 11. Subpatterns that are repeated with specific counts have to be replicated in
972 the compiled pattern. The size of memory for this was computed from the
973 length of the subpattern and the repeat count. The latter is limited to
974 65535, but there was no limit on the former, meaning that integer overflow
975 could in principle occur. The compiled length of a repeated subpattern is
976 now limited to 30,000 bytes in order to prevent this.
977
978 12. Added the optional facility to have named substrings with the same name.
979
980 13. Added the ability to use a named substring as a condition, using the
981 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
982 are numbers (not recommended). Forward references are permitted.
983
984 14. Added forward references in named backreferences (if you see what I mean).
985
986 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
987 pattern could run off the end of the subject. For example, the pattern
988 "(?s)(.{1,5})"8 did this with the subject "ab".
989
990 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
991 PCRE_CASELESS was set when matching characters that were quantified with ?
992 or *.
993
994 17. A character class other than a single negated character that had a minimum
995 but no maximum quantifier - for example [ab]{6,} - was not handled
996 correctly by pce_dfa_exec(). It would match only one character.
997
998 18. A valid (though odd) pattern that looked like a POSIX character
999 class but used an invalid character after [ (for example [[,abc,]]) caused
1000 pcre_compile() to give the error "Failed: internal error: code overflow" or
1001 in some cases to crash with a glibc free() error. This could even happen if
1002 the pattern terminated after [[ but there just happened to be a sequence of
1003 letters, a binary zero, and a closing ] in the memory that followed.
1004
1005 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1006 over the years. Originally (before any Unicode support), just the bottom 8
1007 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1008 output from "man perlunicode" includes this:
1009
1010 The regular expression compiler produces polymorphic opcodes. That
1011 is, the pattern adapts to the data and automatically switches to
1012 the Unicode character scheme when presented with Unicode data--or
1013 instead uses a traditional byte scheme when presented with byte
1014 data.
1015
1016 Sadly, a wide octal escape does not cause a switch, and in a string with
1017 no other multibyte characters, these octal escapes are treated as before.
1018 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1019 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1020 Unicode string.
1021
1022 I have not perpetrated such confusion in PCRE. Up till now, it took just
1023 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1024 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1025 translate to the appropriate multibyte character.
1026
1027 29. Applied some refactoring to reduce the number of warnings from Microsoft
1028 and Borland compilers. This has included removing the fudge introduced
1029 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1030 a warning about an unused variable.
1031
1032 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1033 characters since release 4.0, because Perl (from release 5.004) does not.
1034 [Or at least, is documented not to: some releases seem to be in conflict
1035 with the documentation.] However, when a pattern was studied with
1036 pcre_study() and all its branches started with \s, PCRE still included VT
1037 as a possible starting character. Of course, this did no harm; it just
1038 caused an unnecessary match attempt.
1039
1040 22. Removed a now-redundant internal flag bit that recorded the fact that case
1041 dependency changed within the pattern. This was once needed for "required
1042 byte" processing, but is no longer used. This recovers a now-scarce options
1043 bit. Also moved the least significant internal flag bit to the most-
1044 significant bit of the word, which was not previously used (hangover from
1045 the days when it was an int rather than a uint) to free up another bit for
1046 the future.
1047
1048 23. Added support for CRLF line endings as well as CR and LF. As well as the
1049 default being selectable at build time, it can now be changed at runtime
1050 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1051 specify that it is scanning data with non-default line endings.
1052
1053 24. Changed the definition of CXXLINK to make it agree with the definition of
1054 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1055
1056 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1057 recursions. This makes a big different to stack usage for some patterns.
1058
1059 26. If a subpattern containing a named recursion or subroutine reference such
1060 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1061 the space required for the compiled pattern went wrong and gave too small a
1062 value. Depending on the environment, this could lead to "Failed: internal
1063 error: code overflow at offset 49" or "glibc detected double free or
1064 corruption" errors.
1065
1066 27. Applied patches from Google (a) to support the new newline modes and (b) to
1067 advance over multibyte UTF-8 characters in GlobalReplace.
1068
1069 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1070 difference for some implementation of PCRE in some Windows version.
1071
1072 29. Added some extra testing facilities to pcretest:
1073
1074 \q<number> in a data line sets the "match limit" value
1075 \Q<number> in a data line sets the "match recursion limt" value
1076 -S <number> sets the stack size, where <number> is in megabytes
1077
1078 The -S option isn't available for Windows.
1079
1080
1081 Version 6.6 06-Feb-06
1082 ---------------------
1083
1084 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1085 in pcreposix.h. I have copied the definition from pcre.h.
1086
1087 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1088 because pcre.h is no longer a built file.
1089
1090 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1091 not normally included in the compiled code.
1092
1093
1094 Version 6.5 01-Feb-06
1095 ---------------------
1096
1097 1. When using the partial match feature with pcre_dfa_exec(), it was not
1098 anchoring the second and subsequent partial matches at the new starting
1099 point. This could lead to incorrect results. For example, with the pattern
1100 /1234/, partially matching against "123" and then "a4" gave a match.
1101
1102 2. Changes to pcregrep:
1103
1104 (a) All non-match returns from pcre_exec() were being treated as failures
1105 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1106 error message is output. Some extra information is given for the
1107 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1108 probably the only errors that are likely to be caused by users (by
1109 specifying a regex that has nested indefinite repeats, for instance).
1110 If there are more than 20 of these errors, pcregrep is abandoned.
1111
1112 (b) A binary zero was treated as data while matching, but terminated the
1113 output line if it was written out. This has been fixed: binary zeroes
1114 are now no different to any other data bytes.
1115
1116 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1117 used to set a locale for matching. The --locale=xxxx long option has
1118 been added (no short equivalent) to specify a locale explicitly on the
1119 pcregrep command, overriding the environment variables.
1120
1121 (d) When -B was used with -n, some line numbers in the output were one less
1122 than they should have been.
1123
1124 (e) Added the -o (--only-matching) option.
1125
1126 (f) If -A or -C was used with -c (count only), some lines of context were
1127 accidentally printed for the final match.
1128
1129 (g) Added the -H (--with-filename) option.
1130
1131 (h) The combination of options -rh failed to suppress file names for files
1132 that were found from directory arguments.
1133
1134 (i) Added the -D (--devices) and -d (--directories) options.
1135
1136 (j) Added the -F (--fixed-strings) option.
1137
1138 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1139
1140 (l) Added the --colo(u)r option.
1141
1142 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1143 is not present by default.
1144
1145 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1146 items such as (?R) or (?1), when the recursion could match a number of
1147 alternatives. If it matched one of the alternatives, but subsequently,
1148 outside the recursion, there was a failure, the code tried to back up into
1149 the recursion. However, because of the way PCRE is implemented, this is not
1150 possible, and the result was an incorrect result from the match.
1151
1152 In order to prevent this happening, the specification of recursion has
1153 been changed so that all such subpatterns are automatically treated as
1154 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1155
1156 4. I had overlooked the fact that, in some locales, there are characters for
1157 which isalpha() is true but neither isupper() nor islower() are true. In
1158 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1159 and ordfeminine) are like this. This affected the treatment of \w and \W
1160 when they appeared in character classes, but not when they appeared outside
1161 a character class. The bit map for "word" characters is now created
1162 separately from the results of isalnum() instead of just taking it from the
1163 upper, lower, and digit maps. (Plus the underscore character, of course.)
1164
1165 5. The above bug also affected the handling of POSIX character classes such as
1166 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1167 permanent tables. Instead, the bit maps for such a class were previously
1168 created as the appropriate unions of the upper, lower, and digit bitmaps.
1169 Now they are created by subtraction from the [[:word:]] class, which has
1170 its own bitmap.
1171
1172 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1173 It is created by subtracting the vertical space characters (\x09, \x0a,
1174 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1175 subtraction was done in the overall bitmap for a character class, meaning
1176 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1177 be recognized. This bug has been fixed.
1178
1179 7. Patches from the folks at Google:
1180
1181 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1182 real life, but is still worth protecting against".
1183
1184 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1185 regular expressions".
1186
1187 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1188 have it.
1189
1190 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1191 "configure" and the latter not, in order to fix a problem somebody had
1192 with compiling the Arg class on HP-UX.
1193
1194 (e) Improve the error-handling of the C++ wrapper a little bit.
1195
1196 (f) New tests for checking recursion limiting.
1197
1198 8. The pcre_memmove() function, which is used only if the environment does not
1199 have a standard memmove() function (and is therefore rarely compiled),
1200 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1201 returning a result (though PCRE never actually uses the result).
1202
1203 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1204 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1205 returned instead of calling malloc() with an overflowing number that would
1206 most likely cause subsequent chaos.
1207
1208 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1209
1210 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1211 with this option is matched, the nmatch and pmatch options of regexec() are
1212 ignored.
1213
1214 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1215 provided in case anyone wants to the the POSIX interface with UTF-8
1216 strings.
1217
1218 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1219 C++ linking (needed for some HP-UX environments).
1220
1221 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1222 (unused parameter) and in the pcre_printint() function (omitted "default"
1223 switch label when the default is to do nothing).
1224
1225 15. Added some code to make it possible, when PCRE is compiled as a C++
1226 library, to replace subject pointers for pcre_exec() with a smart pointer
1227 class, thus making it possible to process discontinuous strings.
1228
1229 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1230 much the same function. They were added by different people who were trying
1231 to make PCRE easy to compile on non-Unix systems. It has been suggested
1232 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1233 for compiling on Windows systems. I have therefore replaced it with
1234 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1235 defaults to "extern" for C or "extern C" for C++, which works fine on
1236 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1237 SCOPE with something explicit in config.h. In addition:
1238
1239 (a) pcreposix.h still had just "extern" instead of either of these macros;
1240 I have replaced it with PCRE_DATA_SCOPE.
1241
1242 (b) Functions such as _pcre_xclass(), which are internal to the library,
1243 but external in the C sense, all had PCRE_EXPORT in their definitions.
1244 This is apparently wrong for the Windows case, so I have removed it.
1245 (It makes no difference on Unix-like systems.)
1246
1247 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1248 of recursive calls to match(). This is different to MATCH_LIMIT because
1249 that limits the total number of calls to match(), not all of which increase
1250 the depth of recursion. Limiting the recursion depth limits the amount of
1251 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1252 when PCRE is compiled, and changed at run time. A patch from Google adds
1253 this functionality to the C++ interface.
1254
1255 18. Changes to the handling of Unicode character properties:
1256
1257 (a) Updated the table to Unicode 4.1.0.
1258
1259 (b) Recognize characters that are not in the table as "Cn" (undefined).
1260
1261 (c) I revised the way the table is implemented to a much improved format
1262 which includes recognition of ranges. It now supports the ranges that
1263 are defined in UnicodeData.txt, and it also amalgamates other
1264 characters into ranges. This has reduced the number of entries in the
1265 table from around 16,000 to around 3,000, thus reducing its size
1266 considerably. I realized I did not need to use a tree structure after
1267 all - a binary chop search is just as efficient. Having reduced the
1268 number of entries, I extended their size from 6 bytes to 8 bytes to
1269 allow for more data.
1270
1271 (d) Added support for Unicode script names via properties such as \p{Han}.
1272
1273 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1274 matching that character.
1275
1276 20. When matching a repeated Unicode property with a minimum greater than zero,
1277 (for example \pL{2,}), PCRE could look past the end of the subject if it
1278 reached it while seeking the minimum number of characters. This could
1279 happen only if some of the characters were more than one byte long, because
1280 there is a check for at least the minimum number of bytes.
1281
1282 21. Refactored the implementation of \p and \P so as to be more general, to
1283 allow for more different types of property in future. This has changed the
1284 compiled form incompatibly. Anybody with saved compiled patterns that use
1285 \p or \P will have to recompile them.
1286
1287 22. Added "Any" and "L&" to the supported property types.
1288
1289 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1290 but give a compile time error if the value is greater than 0xff.
1291
1292 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1293 accidentally not being installed or uninstalled.
1294
1295 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1296 made were to insert the current release number. This seemed silly, because
1297 it made things harder for people building PCRE on systems that don't run
1298 "configure". I have turned pcre.h into a distributed file, no longer built
1299 by "configure", with the version identification directly included. There is
1300 no longer a pcre.h.in file.
1301
1302 However, this change necessitated a change to the pcre-config script as
1303 well. It is built from pcre-config.in, and one of the substitutions was the
1304 release number. I have updated configure.ac so that ./configure now finds
1305 the release number by grepping pcre.h.
1306
1307 26. Added the ability to run the tests under valgrind.
1308
1309
1310 Version 6.4 05-Sep-05
1311 ---------------------
1312
1313 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1314 "--" to be printed when multiple files were scanned, even when none of the
1315 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1316 consider it to be a bug, and have restored the previous behaviour.
1317
1318 2. A couple of code tidies to get rid of compiler warnings.
1319
1320 3. The pcretest program used to cheat by referring to symbols in the library
1321 whose names begin with _pcre_. These are internal symbols that are not
1322 really supposed to be visible externally, and in some environments it is
1323 possible to suppress them. The cheating is now confined to including
1324 certain files from the library's source, which is a bit cleaner.
1325
1326 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1327 file's purpose clearer.
1328
1329 5. Reorganized pcre_ucp_findchar().
1330
1331
1332 Version 6.3 15-Aug-05
1333 ---------------------
1334
1335 1. The file libpcre.pc.in did not have general read permission in the tarball.
1336
1337 2. There were some problems when building without C++ support:
1338
1339 (a) If C++ support was not built, "make install" and "make test" still
1340 tried to test it.
1341
1342 (b) There were problems when the value of CXX was explicitly set. Some
1343 changes have been made to try to fix these, and ...
1344
1345 (c) --disable-cpp can now be used to explicitly disable C++ support.
1346
1347 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1348 backslash in a target when C++ was disabled. This confuses some
1349 versions of "make", apparently. Using an intermediate variable solves
1350 this. (Same for CPP_LOBJ.)
1351
1352 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1353 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1354 necessary on certain architectures.
1355
1356 4. Added a setting of -export-symbols-regex to the link command to remove
1357 those symbols that are exported in the C sense, but actually are local
1358 within the library, and not documented. Their names all begin with
1359 "_pcre_". This is not a perfect job, because (a) we have to except some
1360 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1361 available (and never for static libraries). I have made a note to try to
1362 find a way round (a) in the future.
1363
1364
1365 Version 6.2 01-Aug-05
1366 ---------------------
1367
1368 1. There was no test for integer overflow of quantifier values. A construction
1369 such as {1111111111111111} would give undefined results. What is worse, if
1370 a minimum quantifier for a parenthesized subpattern overflowed and became
1371 negative, the calculation of the memory size went wrong. This could have
1372 led to memory overwriting.
1373
1374 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1375
1376 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1377 operating environments where this matters.
1378
1379 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1380 PCRE options from within the C++ wrapper.
1381
1382 5. Named capturing subpatterns were not being correctly counted when a pattern
1383 was compiled. This caused two problems: (a) If there were more than 100
1384 such subpatterns, the calculation of the memory needed for the whole
1385 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1386 back references of the form \12, where the number was greater than 9, were
1387 not recognized as back references, even though there were sufficient
1388 previous subpatterns.
1389
1390 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1391 versions of gcc, e.g. 2.95.4.
1392
1393
1394 Version 6.1 21-Jun-05
1395 ---------------------
1396
1397 1. There was one reference to the variable "posix" in pcretest.c that was not
1398 surrounded by "#if !defined NOPOSIX".
1399
1400 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1401 the cross-check on the old pcre_info() function, for the benefit of the
1402 cut-down version of PCRE that is currently imported into Exim.
1403
1404 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1405 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1406 patterns that start (?i) but I don't think that matters. The use of (?i) is
1407 just an example; this all applies to the other options as well.
1408
1409 4. Since libtool seems to echo the compile commands it is issuing, the output
1410 from "make" can be reduced a bit by putting "@" in front of each libtool
1411 compile command.
1412
1413 5. Patch from the folks at Google for configure.in to be a bit more thorough
1414 in checking for a suitable C++ installation before trying to compile the
1415 C++ stuff. This should fix a reported problem when a compiler was present,
1416 but no suitable headers.
1417
1418 6. The man pages all had just "PCRE" as their title. I have changed them to
1419 be the relevant file name. I have also arranged that these names are
1420 retained in the file doc/pcre.txt, which is a concatenation in text format
1421 of all the man pages except the little individual ones for each function.
1422
1423 7. The NON-UNIX-USE file had not been updated for the different set of source
1424 files that come with release 6. I also added a few comments about the C++
1425 wrapper.
1426
1427
1428 Version 6.0 07-Jun-05
1429 ---------------------
1430
1431 1. Some minor internal re-organization to help with my DFA experiments.
1432
1433 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1434 didn't matter for the library itself when fully configured, but did matter
1435 when compiling without UCP support, or within Exim, where the ucp files are
1436 not imported.
1437
1438 3. Refactoring of the library code to split up the various functions into
1439 different source modules. The addition of the new DFA matching code (see
1440 below) to a single monolithic source would have made it really too
1441 unwieldy, quite apart from causing all the code to be include in a
1442 statically linked application, when only some functions are used. This is
1443 relevant even without the DFA addition now that patterns can be compiled in
1444 one application and matched in another.
1445
1446 The downside of splitting up is that there have to be some external
1447 functions and data tables that are used internally in different modules of
1448 the library but which are not part of the API. These have all had their
1449 names changed to start with "_pcre_" so that they are unlikely to clash
1450 with other external names.
1451
1452 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1453 a different (DFA) algorithm. Although it is slower than the original
1454 function, it does have some advantages for certain types of matching
1455 problem.
1456
1457 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1458 including restarting after a partial match.
1459
1460 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1461 defined when compiling for Windows was sent to me. I have put it into the
1462 code, though I have no means of testing or verifying it.
1463
1464 7. Added the pcre_refcount() auxiliary function.
1465
1466 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1467 match before or at the first newline in the subject string. In pcretest,
1468 the /f option on a pattern can be used to set this.
1469
1470 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1471 would behave wrongly. This has been present in PCRE since release 4.0.
1472
1473 10. A number of changes to the pcregrep command:
1474
1475 (a) Refactored how -x works; insert ^(...)$ instead of setting
1476 PCRE_ANCHORED and checking the length, in preparation for adding
1477 something similar for -w.
1478
1479 (b) Added the -w (match as a word) option.
1480
1481 (c) Refactored the way lines are read and buffered so as to have more
1482 than one at a time available.
1483
1484 (d) Implemented a pcregrep test script.
1485
1486 (e) Added the -M (multiline match) option. This allows patterns to match
1487 over several lines of the subject. The buffering ensures that at least
1488 8K, or the rest of the document (whichever is the shorter) is available
1489 for matching (and similarly the previous 8K for lookbehind assertions).
1490
1491 (f) Changed the --help output so that it now says
1492
1493 -w, --word-regex(p)
1494
1495 instead of two lines, one with "regex" and the other with "regexp"
1496 because that confused at least one person since the short forms are the
1497 same. (This required a bit of code, as the output is generated
1498 automatically from a table. It wasn't just a text change.)
1499
1500 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1501 option but starts with a hyphen. Could be a pattern or a path name
1502 starting with a hyphen, for instance.
1503
1504 (h) "-" can be given as a file name to represent stdin.
1505
1506 (i) When file names are being printed, "(standard input)" is used for
1507 the standard input, for compatibility with GNU grep. Previously
1508 "<stdin>" was used.
1509
1510 (j) The option --label=xxx can be used to supply a name to be used for
1511 stdin when file names are being printed. There is no short form.
1512
1513 (k) Re-factored the options decoding logic because we are going to add
1514 two more options that take data. Such options can now be given in four
1515 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1516
1517 (l) Added the -A, -B, and -C options for requesting that lines of context
1518 around matches be printed.
1519
1520 (m) Added the -L option to print the names of files that do not contain
1521 any matching lines, that is, the complement of -l.
1522
1523 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1524 continue to scan other files.
1525
1526 (o) The -s option was incorrectly implemented. For compatibility with other
1527 greps, it now suppresses the error message for a non-existent or non-
1528 accessible file (but not the return code). There is a new option called
1529 -q that suppresses the output of matching lines, which was what -s was
1530 previously doing.
1531
1532 (p) Added --include and --exclude options to specify files for inclusion
1533 and exclusion when recursing.
1534
1535 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1536 Hopefully, it now does.
1537
1538 12. Missing cast in pcre_study().
1539
1540 13. Added an "uninstall" target to the makefile.
1541
1542 14. Replaced "extern" in the function prototypes in Makefile.in with
1543 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1544 world, but is set differently for Windows.
1545
1546 15. Added a second compiling function called pcre_compile2(). The only
1547 difference is that it has an extra argument, which is a pointer to an
1548 integer error code. When there is a compile-time failure, this is set
1549 non-zero, in addition to the error test pointer being set to point to an
1550 error message. The new argument may be NULL if no error number is required
1551 (but then you may as well call pcre_compile(), which is now just a
1552 wrapper). This facility is provided because some applications need a
1553 numeric error indication, but it has also enabled me to tidy up the way
1554 compile-time errors are handled in the POSIX wrapper.
1555
1556 16. Added VPATH=.libs to the makefile; this should help when building with one
1557 prefix path and installing with another. (Or so I'm told by someone who
1558 knows more about this stuff than I do.)
1559
1560 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1561 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1562 match everything, including newlines. This is not POSIX-compatible, but
1563 somebody wanted the feature. From pcretest it can be activated by using
1564 both the P and the s flags.
1565
1566 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1567
1568 19. libpcre.pc was being incorrectly installed as executable.
1569
1570 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1571 it now also looks for '\r' so that it will work unmodified on Windows.
1572
1573 21. Added Google's contributed C++ wrapper to the distribution.
1574
1575 22. Added some untidy missing memory free() calls in pcretest, to keep
1576 Electric Fence happy when testing.
1577
1578
1579
1580 Version 5.0 13-Sep-04
1581 ---------------------
1582
1583 1. Internal change: literal characters are no longer packed up into items
1584 containing multiple characters in a single byte-string. Each character
1585 is now matched using a separate opcode. However, there may be more than one
1586 byte in the character in UTF-8 mode.
1587
1588 2. The pcre_callout_block structure has two new fields: pattern_position and
1589 next_item_length. These contain the offset in the pattern to the next match
1590 item, and its length, respectively.
1591
1592 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1593 insertion of callouts before each pattern item. Added the /C option to
1594 pcretest to make use of this.
1595
1596 4. On the advice of a Windows user, the lines
1597
1598 #if defined(_WIN32) || defined(WIN32)
1599 _setmode( _fileno( stdout ), 0x8000 );
1600 #endif /* defined(_WIN32) || defined(WIN32) */
1601
1602 have been added to the source of pcretest. This apparently does useful
1603 magic in relation to line terminators.
1604
1605 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1606 for the benefit of those environments where the "b" makes a difference.
1607
1608 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1609 to know about it. I have put a hack into configure.in that adds in code
1610 to set GCC=yes if CC=icc. This seems to end up at a point in the
1611 generated configure script that is early enough to affect the setting of
1612 compiler options, which is what is needed, but I have no means of testing
1613 whether it really works. (The user who reported this had patched the
1614 generated configure script, which of course I cannot do.)
1615
1616 LATER: After change 22 below (new libtool files), the configure script
1617 seems to know about icc (and also ecc). Therefore, I have commented out
1618 this hack in configure.in.
1619
1620 7. Added support for pkg-config (2 patches were sent in).
1621
1622 8. Negated POSIX character classes that used a combination of internal tables
1623 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1624 [[:^ascii]]. Typically, they would match almost any characters. The other
1625 POSIX classes were not broken in this way.
1626
1627 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1628 to find the match, as PCRE was deluded into thinking that the match had to
1629 start at the start point or following a newline. The same bug applied to
1630 patterns with negative forward assertions or any backward assertions
1631 preceding ".*" at the start, unless the pattern required a fixed first
1632 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1633
1634 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1635 starting at the last subject character, bytes beyond the end of the subject
1636 string were read.
1637
1638 11. Renamed the variable "class" as "classbits" to make life easier for C++
1639 users. (Previously there was a macro definition, but it apparently wasn't
1640 enough.)
1641
1642 12. Added the new field "tables" to the extra data so that tables can be passed
1643 in at exec time, or the internal tables can be re-selected. This allows
1644 a compiled regex to be saved and re-used at a later time by a different
1645 program that might have everything at different addresses.
1646
1647 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1648 -R library as well as a -L library.
1649
1650 14. The debugging options of pcretest (-d on the command line or D on a
1651 pattern) showed incorrect output for anything following an extended class
1652 that contained multibyte characters and which was followed by a quantifier.
1653
1654 15. Added optional support for general category Unicode character properties
1655 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1656 support. It adds about 90K to the size of the library. The meanings of the
1657 inbuilt class escapes such as \d and \s have NOT been changed.
1658
1659 16. Updated pcredemo.c to include calls to free() to release the memory for the
1660 compiled pattern.
1661
1662 17. The generated file chartables.c was being created in the source directory
1663 instead of in the building directory. This caused the build to fail if the
1664 source directory was different from the building directory, and was
1665 read-only.
1666
1667 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1668 file. No doubt somebody will tell me if they don't make sense... Also added
1669 Dan Mooney's comments about building on OpenVMS.
1670
1671 19. Added support for partial matching via the PCRE_PARTIAL option for
1672 pcre_exec() and the \P data escape in pcretest.
1673
1674 20. Extended pcretest with 3 new pattern features:
1675
1676 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1677 write the compiled pattern to the file whose name is "rest-of-line".
1678 This is a straight binary dump of the data, with the saved pointer to
1679 the character tables forced to be NULL. The study data, if any, is
1680 written too. After writing, pcretest reads a new pattern.
1681
1682 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1683 compiled pattern from the given file. There must not be any
1684 occurrences of "<" in the file name (pretty unlikely); if there are,
1685 pcretest will instead treat the initial "<" as a pattern delimiter.
1686 After reading in the pattern, pcretest goes on to read data lines as
1687 usual.
1688
1689 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1690 and 16-bit fields in a compiled pattern, to simulate a pattern that
1691 was compiled on a host of opposite endianness.
1692
1693 21. The pcre-exec() function can now cope with patterns that were compiled on
1694 hosts of opposite endianness, with this restriction:
1695
1696 As for any compiled expression that is saved and used later, the tables
1697 pointer field cannot be preserved; the extra_data field in the arguments
1698 to pcre_exec() should be used to pass in a tables address if a value
1699 other than the default internal tables were used at compile time.
1700
1701 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1702 now diagnosed as an error. Previously, most of the time, a negative number
1703 would have been treated as zero, but if in addition "ovector" was passed as
1704 NULL, a crash could occur.
1705
1706 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1707 new versions from the libtool 1.5 distribution (the last one is a copy of
1708 a file called libtool.m4). This seems to have fixed the need to patch
1709 "configure" to support Darwin 1.3 (which I used to do). However, I still
1710 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1711 workstation).
1712
1713 24. Changed the PCRE licence to be the more standard "BSD" licence.
1714
1715
1716 Version 4.5 01-Dec-03
1717 ---------------------
1718
1719 1. There has been some re-arrangement of the code for the match() function so
1720 that it can be compiled in a version that does not call itself recursively.
1721 Instead, it keeps those local variables that need separate instances for
1722 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1723 needs to "recurse". Keeping track of where control must go is done by means
1724 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1725 hide most of the details from the main code, and operates only if
1726 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1727 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1728 operating.
1729
1730 To make it easier for callers to provide specially tailored get/free
1731 functions for this usage, two new functions, pcre_stack_malloc, and
1732 pcre_stack_free, are used. They are always called in strict stacking order,
1733 and the size of block requested is always the same.
1734
1735 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1736 PCRE has been compiled to use the stack or the heap for recursion. The
1737 -C option of pcretest uses this to show which version is compiled.
1738
1739 A new data escape \S, is added to pcretest; it causes the amounts of store
1740 obtained and freed by both kinds of malloc/free at match time to be added
1741 to the output.
1742
1743 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1744 what's available on my current Linux desktop machine.
1745
1746 3. When matching a UTF-8 string, the test for a valid string at the start has
1747 been extended. If start_offset is not zero, PCRE now checks that it points
1748 to a byte that is the start of a UTF-8 character. If not, it returns
1749 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1750 this is necessary because there may be backward assertions in the pattern.
1751 When matching the same subject several times, it may save resources to use
1752 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1753
1754 4. The code for checking the validity of UTF-8 strings has been tightened so
1755 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1756 containing "overlong sequences".
1757
1758 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1759 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1760 should have been "&", but it just so happened that all the cases this let
1761 through by mistake were picked up later in the function.
1762
1763 6. I had used a variable called "isblank" - this is a C99 function, causing
1764 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1765
1766 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1767 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1768 so the version is shown; (c) stop "make test" echoing "./RunTest".
1769
1770 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1771
1772 9. The prototype for memmove() for systems that don't have it was using
1773 size_t, but the inclusion of the header that defines size_t was later. I've
1774 moved the #includes for the C headers earlier to avoid this.
1775
1776 10. Added some adjustments to the code to make it easier to compiler on certain
1777 special systems:
1778
1779 (a) Some "const" qualifiers were missing.
1780 (b) Added the macro EXPORT before all exported functions; by default this
1781 is defined to be empty.
1782 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1783 that it reads its output file name as an argument instead of writing
1784 to the standard output and assuming this can be redirected.
1785
1786 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1787 class containing characters with values greater than 255, PCRE compilation
1788 went into a loop.
1789
1790 12. A recursive reference to a subpattern that was within another subpattern
1791 that had a minimum quantifier of zero caused PCRE to crash. For example,
1792 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1793 recursion. If the recursively-called subpattern itself had a zero repeat,
1794 that was OK.
1795
1796 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1797 buffer into which it was copied (for escape processing) was still set at
1798 1024, so long lines caused crashes.
1799
1800 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1801 "internal error: code overflow...". This applied to any character class
1802 that was followed by a possessive quantifier.
1803
1804 15. Modified the Makefile to add libpcre.la as a prerequisite for
1805 libpcreposix.la because I was told this is needed for a parallel build to
1806 work.
1807
1808 16. If a pattern that contained .* following optional items at the start was
1809 studied, the wrong optimizing data was generated, leading to matching
1810 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1811 matching string must start with a or b or c. The correct conclusion for
1812 this pattern is that a match can start with any character.
1813
1814
1815 Version 4.4 13-Aug-03
1816 ---------------------
1817
1818 1. In UTF-8 mode, a character class containing characters with values between
1819 127 and 255 was not handled correctly if the compiled pattern was studied.
1820 In fixing this, I have also improved the studying algorithm for such
1821 classes (slightly).
1822
1823 2. Three internal functions had redundant arguments passed to them. Removal
1824 might give a very teeny performance improvement.
1825
1826 3. Documentation bug: the value of the capture_top field in a callout is *one
1827 more than* the number of the hightest numbered captured substring.
1828
1829 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1830 in incorrectly linking with a previously installed version. They now link
1831 explicitly with libpcre.la.
1832
1833 5. configure.in no longer needs to recognize Cygwin specially.
1834
1835 6. A problem in pcre.in for Windows platforms is fixed.
1836
1837 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1838 pcretest, it used to include the size of the study block as part of its
1839 output. Unfortunately, the structure contains a field that has a different
1840 size on different hardware architectures. This meant that the tests that
1841 showed this size failed. As the block is currently always of a fixed size,
1842 this information isn't actually particularly useful in pcretest output, so
1843 I have just removed it.
1844
1845 8. Three pre-processor statements accidentally did not start in column 1.
1846 Sadly, there are *still* compilers around that complain, even though
1847 standard C has not required this for well over a decade. Sigh.
1848
1849 9. In pcretest, the code for checking callouts passed small integers in the
1850 callout_data field, which is a void * field. However, some picky compilers
1851 complained about the casts involved for this on 64-bit systems. Now
1852 pcretest passes the address of the small integer instead, which should get
1853 rid of the warnings.
1854
1855 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1856 both compile and run time, and gives an error if an invalid UTF-8 sequence
1857 is found. There is a option for disabling this check in cases where the
1858 string is known to be correct and/or the maximum performance is wanted.
1859
1860 11. In response to a bug report, I changed one line in Makefile.in from
1861
1862 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1863 to
1864 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1865
1866 to look similar to other lines, but I have no way of telling whether this
1867 is the right thing to do, as I do not use Windows. No doubt I'll get told
1868 if it's wrong...
1869
1870
1871 Version 4.3 21-May-03
1872 ---------------------
1873
1874 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1875 Makefile.
1876
1877 2. Some refactoring to improve the quality of the code:
1878
1879 (i) The utf8_table... variables are now declared "const".
1880
1881 (ii) The code for \cx, which used the "case flipping" table to upper case
1882 lower case letters, now just substracts 32. This is ASCII-specific,
1883 but the whole concept of \cx is ASCII-specific, so it seems
1884 reasonable.
1885
1886 (iii) PCRE was using its character types table to recognize decimal and
1887 hexadecimal digits in the pattern. This is silly, because it handles
1888 only 0-9, a-f, and A-F, but the character types table is locale-
1889 specific, which means strange things might happen. A private
1890 table is now used for this - though it costs 256 bytes, a table is
1891 much faster than multiple explicit tests. Of course, the standard
1892 character types table is still used for matching digits in subject
1893 strings against \d.
1894
1895 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1896 ending in _t are). So I've renamed it as ESC_tee.
1897
1898 3. The first argument for regexec() in the POSIX wrapper should have been
1899 defined as "const".
1900
1901 4. Changed pcretest to use malloc() for its buffers so that they can be
1902 Electric Fenced for debugging.
1903
1904 5. There were several places in the code where, in UTF-8 mode, PCRE would try
1905 to read one or more bytes before the start of the subject string. Often this
1906 had no effect on PCRE's behaviour, but in some circumstances it could
1907 provoke a segmentation fault.
1908
1909 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1910 to try to read one or more bytes before the start of the subject string.
1911
1912 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1913 UTF-8 support could misbehave in various ways if the subject string
1914 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1915 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1916 back over UTF-8 characters.)
1917
1918
1919 Version 4.2 14-Apr-03
1920 ---------------------
1921
1922 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1923
1924 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1925 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1926 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1927 [WIN_PREFIX]: new variable, "cyg" for Cygwin
1928 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1929 and BUILD_EXEEXT
1930 Note: automatic setting of the BUILD variables is not yet working
1931 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1932 compile-time but not at link-time
1933 [LINK]: use for linking executables only
1934 make different versions for Windows and non-Windows
1935 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1936 libraries
1937 [LINK_FOR_BUILD]: new variable
1938 [OBJEXT]: use throughout
1939 [EXEEXT]: use throughout
1940 <winshared>: new target
1941 <wininstall>: new target
1942 <dftables.o>: use native compiler
1943 <dftables>: use native linker
1944 <install>: handle Windows platform correctly
1945 <clean>: ditto
1946 <check>: ditto
1947 copy DLL to top builddir before testing
1948
1949 As part of these changes, -no-undefined was removed again. This was reported
1950 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
1951 in any case.
1952
1953 3. Some tidies to get rid of compiler warnings:
1954
1955 . In the match_data structure, match_limit was an unsigned long int, whereas
1956 match_call_count was an int. I've made them both unsigned long ints.
1957
1958 . In pcretest the fact that a const uschar * doesn't automatically cast to
1959 a void * provoked a warning.
1960
1961 . Turning on some more compiler warnings threw up some "shadow" variables
1962 and a few more missing casts.
1963
1964 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
1965 option, a class that contained a single character with a value between 128
1966 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
1967
1968 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
1969 option, a class that contained several characters, but with at least one
1970 whose value was between 128 and 255 caused PCRE to crash.
1971
1972
1973 Version 4.1 12-Mar-03
1974 ---------------------
1975
1976 1. Compiling with gcc -pedantic found a couple of places where casts were
1977 needed, and a string in dftables.c that was longer than standard compilers are
1978 required to support.
1979
1980 2. Compiling with Sun's compiler found a few more places where the code could
1981 be tidied up in order to avoid warnings.
1982
1983 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
1984 first of these names is deprecated in the latest Autoconf in favour of the name
1985 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
1986 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
1987 analogy I have changed it to CFLAGS_FOR_BUILD.
1988
1989 4. Added -no-undefined to the linking command in the Makefile, because this is
1990 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
1991 linking step for the pcreposix library.
1992
1993 5. PCRE was failing to diagnose the case of two named groups with the same
1994 name.
1995
1996 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
1997 literal character that is needed in the subject for a match, and scans along to
1998 ensure that it is present before embarking on the full matching process. This
1999 saves time in cases of nested unlimited repeats that are never going to match.
2000 Problem: the scan can take a lot of time if the subject is very long (e.g.
2001 megabytes), thus penalizing straightforward matches. It is now done only if the
2002 amount of subject to be scanned is less than 1000 bytes.
2003
2004 7. A lesser problem with the same optimization is that it was recording the
2005 first character of an anchored pattern as "needed", thus provoking a search
2006 right along the subject, even when the first match of the pattern was going to
2007 fail. The "needed" character is now not set for anchored patterns, unless it
2008 follows something in the pattern that is of non-fixed length. Thus, it still
2009 fulfils its original purpose of finding quick non-matches in cases of nested
2010 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2011
2012
2013 Version 4.0 17-Feb-03
2014 ---------------------
2015
2016 1. If a comment in an extended regex that started immediately after a meta-item
2017 extended to the end of string, PCRE compiled incorrect data. This could lead to
2018 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2019
2020 2. Moved to autoconf 2.53 and libtool 1.4.2.
2021
2022 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2023 the special perltest8 script is no longer needed - all the tests can be run
2024 from a single perltest script.
2025
2026 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2027 by \s. It has now been removed in PCRE. This means it isn't recognized as
2028 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2029 class [:space:] *does* include VT, thereby creating a mess.
2030
2031 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2032 space and tab.
2033
2034 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2035 its new features into the main test script, reducing the number of scripts.
2036
2037 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2038 were backward compatible, and made the (?i) apply to the whole pattern, as if
2039 /i were given. Now it behaves more logically, and applies the option setting
2040 only to what follows. PCRE has been changed to follow suit. However, if it
2041 finds options settings right at the start of the pattern, it extracts them into
2042 the global options, as before. Thus, they show up in the info data.
2043
2044 8. Added support for the \Q...\E escape sequence. Characters in between are
2045 treated as literals. This is slightly different from Perl in that $ and @ are
2046 also handled as literals inside the quotes. In Perl, they will cause variable
2047 interpolation. Note the following examples:
2048
2049 Pattern PCRE matches Perl matches
2050
2051 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2052 \Qabc\$xyz\E abc\$xyz abc\$xyz
2053 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2054
2055 For compatibility with Perl, \Q...\E sequences are recognized inside character
2056 classes as well as outside them.
2057
2058 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2059 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2060 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2061 signed/unsigned warnings.
2062
2063 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2064 option for pcretest, so I've replaced it by a simple function that does just
2065 that job.
2066
2067 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2068 "pcregrep -".
2069
2070 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2071 Java package. This provides some syntactic sugar for simple cases of what my
2072 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2073 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2074 item, you can use this simplified notation. Note that only makes sense with
2075 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2076 greediness, whatever the setting of the PCRE_UNGREEDY option.
2077
2078 13. A change of greediness default within a pattern was not taking effect at
2079 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2080 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2081 was abstracted outside.
2082
2083 14. PCRE now supports the \G assertion. It is true when the current matching
2084 position is at the start point of the match. This differs from \A when the
2085 starting offset is non-zero. Used with the /g option of pcretest (or similar
2086 code), it works in the same way as it does for Perl's /g option. If all
2087 alternatives of a regex begin with \G, the expression is anchored to the start
2088 match position, and the "anchored" flag is set in the compiled expression.
2089
2090 15. Some bugs concerning the handling of certain option changes within patterns
2091 have been fixed. These applied to options other than (?ims). For example,
2092 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2093 been the other way round. Some of this was related to change 7 above.
2094
2095 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2096 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2097 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2098 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2099
2100 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2101 mode. Unlike ".", it always matches newline, whatever the setting of
2102 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2103 assertions. Perl allows it, but it doesn't (in general) work because it can't
2104 calculate the length of the lookbehind. At least, that's the case for Perl
2105 5.8.0 - I've been told they are going to document that it doesn't work in
2106 future.
2107
2108 18. Added an error diagnosis for escapes that PCRE does not support: these are
2109 \L, \l, \N, \P, \p, \U, \u, and \X.
2110
2111 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2112 reading past the end of the pattern in cases such as /[abcd/.
2113
2114 20. PCRE was getting more memory than necessary for patterns with classes that
2115 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2116
2117 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2118 compiling PCRE for use with Virtual Pascal.
2119
2120 22. Small fix to the Makefile to make it work properly if the build is done
2121 outside the source tree.
2122
2123 23. Added a new extension: a condition to go with recursion. If a conditional
2124 subpattern starts with (?(R) the "true" branch is used if recursion has
2125 happened, whereas the "false" branch is used only at the top level.
2126
2127 24. When there was a very long string of literal characters (over 255 bytes
2128 without UTF support, over 250 bytes with UTF support), the computation of how
2129 much memory was required could be incorrect, leading to segfaults or other
2130 strange effects.
2131
2132 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2133 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2134 there was a subsequent back reference to those brackets. This meant that, for
2135 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2136 possible to check for precisely this case. All we can do is abandon the
2137 optimization if .* occurs inside capturing brackets when there are any back
2138 references whatsoever. (See below for a better fix that came later.)
2139
2140 26. The handling of the optimization for finding the first character of a
2141 non-anchored pattern, and for finding a character that is required later in the
2142 match were failing in some cases. This didn't break the matching; it just
2143 failed to optimize when it could. The way this is done has been re-implemented.
2144
2145 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2146
2147 28. Added a new feature that provides some of the functionality that Perl
2148 provides with (?{...}). The facility is termed a "callout". The way it is done
2149 in PCRE is for the caller to provide an optional function, by setting
2150 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2151 global variable. By default it is unset, which disables all calling out. To get
2152 the function called, the regex must include (?C) at appropriate points. This
2153 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2154 This provides a means of identifying different callout points. When PCRE
2155 reaches such a point in the regex, if pcre_callout has been set, the external
2156 function is called. It is provided with data in a structure called
2157 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2158 matching continues; if it returns a non-zero value, the match at the current
2159 point fails. However, backtracking will occur if possible. [This was changed
2160 later and other features added - see item 49 below.]
2161
2162 29. pcretest is upgraded to test the callout functionality. It provides a
2163 callout function that displays information. By default, it shows the start of
2164 the match and the current position in the text. There are some new data escapes
2165 to vary what happens:
2166
2167 \C+ in addition, show current contents of captured substrings
2168 \C- do not supply a callout function
2169 \C!n return 1 when callout number n is reached
2170 \C!n!m return 1 when callout number n is reached for the mth time
2171
2172 30. If pcregrep was called with the -l option and just a single file name, it
2173 output "<stdin>" if a match was found, instead of the file name.
2174
2175 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2176 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2177 pcre_exec(). This saves a malloc/free per call. The default value of
2178 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2179 when configuring.
2180
2181 32. The default maximum size of a compiled pattern is 64K. There have been a
2182 few cases of people hitting this limit. The code now uses macros to handle the
2183 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2184 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2185 configuring. Tests 2 and 5 work only with 2-byte links because they output
2186 debugging information about compiled patterns.
2187
2188 33. Internal code re-arrangements:
2189
2190 (a) Moved the debugging function for printing out a compiled regex into
2191 its own source file (printint.c) and used #include to pull it into
2192 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2193 separate copies.
2194
2195 (b) Defined the list of op-code names for debugging as a macro in
2196 internal.h so that it is next to the definition of the opcodes.
2197
2198 (c) Defined a table of op-code lengths for simpler skipping along compiled
2199 code. This is again a macro in internal.h so that it is next to the
2200 definition of the opcodes.
2201
2202 34. Added support for recursive calls to individual subpatterns, along the
2203 lines of Robin Houston's patch (but implemented somewhat differently).
2204
2205 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2206 allow it to read and process whole directories in Win32. This code was
2207 contributed by Lionel Fourquaux; it has not been tested by me.
2208
2209 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2210 used to name a group. Names consist of alphanumerics and underscores, and must
2211 be unique. Back references use the syntax (?P=name) and recursive calls use
2212 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2213 numbers. The function pcre_fullinfo() can be used after compilation to extract
2214 a name/number map. There are three relevant calls:
2215
2216 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2217 PCRE_INFO_NAMECOUNT yields the number of entries
2218 PCRE_INFO_NAMETABLE yields a pointer to the map.
2219
2220 The map is a vector of fixed-size entries. The size of each entry depends on
2221 the length of the longest name used. The first two bytes of each entry are the
2222 group number, most significant byte first. There follows the corresponding
2223 name, zero terminated. The names are in alphabetical order.
2224
2225 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2226 case instead of 255. Making it the same both with and without UTF-8 support
2227 means that the same test output works with both.
2228
2229 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2230 calling malloc() with a zero argument.
2231
2232 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2233 optimization. I've improved things by keeping a bitmap of backreferences with
2234 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2235 fact referenced, the optimization can be applied. It is unlikely that a
2236 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2237 the match to follow \n) will appear inside brackets with a number greater than
2238 31, but if it does, any back reference > 31 suppresses the optimization.
2239
2240 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2241 of disabling numbered capturing parentheses. Any opening parenthesis that is
2242 not followed by ? behaves as if it were followed by ?: but named parentheses
2243 can still be used for capturing (and they will acquire numbers in the usual
2244 way).
2245
2246 41. Redesigned the return codes from the match() function into yes/no/error so
2247 that errors can be passed back from deep inside the nested calls. A malloc
2248 failure while inside a recursive subpattern call now causes the
2249 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2250
2251 42. It is now possible to set a limit on the number of times the match()
2252 function is called in a call to pcre_exec(). This facility makes it possible to
2253 limit the amount of recursion and backtracking, though not in a directly
2254 obvious way, because the match() function is used in a number of different
2255 circumstances. The count starts from zero for each position in the subject
2256 string (for non-anchored patterns). The default limit is, for compatibility, a
2257 large number, namely 10 000 000. You can change this in two ways:
2258
2259 (a) When configuring PCRE before making, you can use --with-match-limit=n
2260 to set a default value for the compiled library.
2261
2262 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2263 a different value is set. See 45 below.
2264
2265 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2266
2267 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2268 of things that can be changed at compile time. The first argument specifies
2269 what is wanted and the second points to where the information is to be placed.
2270 The current list of available information is:
2271
2272 PCRE_CONFIG_UTF8
2273
2274 The output is an integer that is set to one if UTF-8 support is available;
2275 otherwise it is set to zero.
2276
2277 PCRE_CONFIG_NEWLINE
2278
2279 The output is an integer that it set to the value of the code that is used for
2280 newline. It is either LF (10) or CR (13).
2281
2282 PCRE_CONFIG_LINK_SIZE
2283
2284 The output is an integer that contains the number of bytes used for internal
2285 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2286
2287 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2288
2289 The output is an integer that contains the threshold above which the POSIX
2290 interface uses malloc() for output vectors. See item 31 above.
2291
2292 PCRE_CONFIG_MATCH_LIMIT
2293
2294 The output is an unsigned integer that contains the default limit of the number
2295 of match() calls in a pcre_exec() execution. See 42 above.
2296
2297 44. pcretest has been upgraded by the addition of the -C option. This causes it
2298 to extract all the available output from the new pcre_config() function, and to
2299 output it. The program then exits immediately.
2300
2301 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2302 order to support additional features. One way would have been to define
2303 pcre_exec2() (for example) with extra arguments, but this would not have been
2304 extensible, and would also have required all calls to the original function to
2305 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2306 is used for passing in "extra" data from pcre_study().
2307
2308 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2309 contains the following fields:
2310
2311 flags a bitmap indicating which of the following fields are set
2312 study_data opaque data from pcre_study()
2313 match_limit a way of specifying a limit on match() calls for a specific
2314 call to pcre_exec()
2315 callout_data data for callouts (see 49 below)
2316
2317 The flag bits are also defined in pcre.h, and are
2318
2319 PCRE_EXTRA_STUDY_DATA
2320 PCRE_EXTRA_MATCH_LIMIT
2321 PCRE_EXTRA_CALLOUT_DATA
2322
2323 The pcre_study() function now returns one of these new pcre_extra blocks, with
2324 the actual study data pointed to by the study_data field, and the
2325 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2326 before. That is, this change is entirely upwards-compatible and requires no
2327 change to existing code.
2328
2329 If you want to pass in additional data to pcre_exec(), you can either place it
2330 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2331 block.
2332
2333 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2334 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2335 times with different match limits, until it finds the minimum value needed for
2336 pcre_exec() to complete. The value is then output. This can be instructive; for
2337 most simple matches the number is quite small, but for pathological cases it
2338 gets very large very quickly.
2339
2340 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2341 returns the size of the data block pointed to by the study_data field in a
2342 pcre_extra block, that is, the value that was passed as the argument to
2343 pcre_malloc() when PCRE was getting memory in which to place the information
2344 created by pcre_study(). The fourth argument should point to a size_t variable.
2345 pcretest has been extended so that this information is shown after a successful
2346 pcre_study() call when information about the compiled regex is being displayed.
2347
2348 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2349 because what follows is always an absolute path. (Later: it turns out that this
2350 is more than cosmetic for MinGW, because it doesn't like empty path
2351 components.)
2352
2353 49. Some changes have been made to the callout feature (see 28 above):
2354
2355 (i) A callout function now has three choices for what it returns:
2356
2357 0 => success, carry on matching
2358 > 0 => failure at this point, but backtrack if possible
2359 < 0 => serious error, return this value from pcre_exec()
2360
2361 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2362 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2363 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2364 use by callout functions. It will never be used by PCRE itself.
2365
2366 (ii) The pcre_extra structure (see 45 above) has a void * field called
2367 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2368 pcre_callout_block structure has a field of the same name. The contents of
2369 the field passed in the pcre_extra structure are passed to the callout
2370 function in the corresponding field in the callout block. This makes it
2371 easier to use the same callout-containing regex from multiple threads. For
2372 testing, the pcretest program has a new data escape
2373
2374 \C*n pass the number n (may be negative) as callout_data
2375
2376 If the callout function in pcretest receives a non-zero value as
2377 callout_data, it returns that value.
2378
2379 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2380 there were some redundant $(CFLAGS) in commands that are now specified as
2381 $(LINK), which already includes $(CFLAGS).
2382
2383 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2384 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2385 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2386 one-byte characters throughout. Note that case-insensitive matching applies
2387 only to characters whose values are less than 256. PCRE doesn't support the
2388 notion of cases for higher-valued characters.
2389
2390 (i) A character class whose characters are all within 0-255 is handled as
2391 a bit map, and the map is inverted for negative classes. Previously, a
2392 character > 255 always failed to match such a class; however it should
2393 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2394
2395 (ii) A negated character class with a single character < 255 is coded as
2396 "not this character" (OP_NOT). This wasn't working properly when the test
2397 character was multibyte, either singly or repeated.
2398
2399 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2400 mode, for example: \x{100}{2,3}.
2401
2402 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2403 singly or repeated) now correctly test multibyte characters. However,
2404 PCRE doesn't recognize any characters with values greater than 255 as
2405 digits, spaces, or word characters. Such characters always match \D, \S,
2406 and \W, and never match \d, \s, or \w.
2407
2408 (v) Classes may now contain characters and character ranges with values
2409 greater than 255. For example: [ab\x{100}-\x{400}].
2410
2411 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2412 PCRE in UTF-8 mode.
2413
2414 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2415 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2416 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2417 value.)
2418
2419 53. The single man page has become too large. I have therefore split it up into
2420 a number of separate man pages. These also give rise to individual HTML pages;
2421 these are now put in a separate directory, and there is an index.html page that
2422 lists them all. Some hyperlinking between the pages has been installed.
2423
2424 54. Added convenience functions for handling named capturing parentheses.
2425
2426 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2427 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2428 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2429 are faulted.
2430
2431 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2432 calling configure. These values are used when compiling the dftables.c program
2433 which is run to generate the source of the default character tables. They
2434 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2435 you will need to set these values.
2436
2437 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2438
2439
2440 Version 3.9 02-Jan-02
2441 ---------------------
2442
2443 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2444
2445 2. If --disable-static was given, the building process failed when trying to
2446 build pcretest and pcregrep. (For some reason it was using libtool to compile
2447 them, which is not right, as they aren't part of the library.)
2448
2449
2450 Version 3.8 18-Dec-01
2451 ---------------------
2452
2453 1. The experimental UTF-8 code was completely screwed up. It was packing the
2454 bytes in the wrong order. How dumb can you get?
2455
2456
2457 Version 3.7 29-Oct-01
2458 ---------------------
2459
2460 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2461 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2462 this didn't happen under Solaris 8, where I normally test things.
2463
2464 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2465 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2466 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2467 this fix an hour or so after the initial 3.7 release.)
2468
2469
2470 Version 3.6 23-Oct-01
2471 ---------------------
2472
2473 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2474 offsets passed as NULL with zero offset count.
2475
2476 2. The config.guess and config.sub files had not been updated when I moved to
2477 the latest autoconf.
2478
2479
2480 Version 3.5 15-Aug-01
2481 ---------------------
2482
2483 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2484 had been forgotten.
2485
2486 2. By using declared but undefined structures, we can avoid using "void"
2487 definitions in pcre.h while keeping the internal definitions of the structures
2488 private.
2489
2490 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2491 user point of view, this means that both static and shared libraries are built
2492 by default, but this can be individually controlled. More of the work of
2493 handling this static/shared cases is now inside libtool instead of PCRE's make
2494 file.
2495
2496 4. The pcretest utility is now installed along with pcregrep because it is
2497 useful for users (to test regexs) and by doing this, it automatically gets
2498 relinked by libtool. The documentation has been turned into a man page, so
2499 there are now .1, .txt, and .html versions in /doc.
2500
2501 5. Upgrades to pcregrep:
2502 (i) Added long-form option names like gnu grep.
2503 (ii) Added --help to list all options with an explanatory phrase.
2504 (iii) Added -r, --recursive to recurse into sub-directories.
2505 (iv) Added -f, --file to read patterns from a file.
2506
2507 6. pcre_exec() was referring to its "code" argument before testing that
2508 argument for NULL (and giving an error if it was NULL).
2509
2510 7. Upgraded Makefile.in to allow for compiling in a different directory from
2511 the source directory.
2512
2513 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2514 options bits, the pointer it was passed was to an int instead of to an unsigned
2515 long int. This mattered only on 64-bit systems.
2516
2517 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2518 generated) instead of pcre.in, which it its source. Also made the same change
2519 in several of the .c files.
2520
2521 10. A new release of gcc defines printf() as a macro, which broke pcretest
2522 because it had an ifdef in the middle of a string argument for printf(). Fixed
2523 by using separate calls to printf().
2524
2525 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2526 script, to force use of CR or LF instead of \n in the source. On non-Unix
2527 systems, the value can be set in config.h.
2528
2529 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2530 absolute limit. Changed the text of the error message to make this clear, and
2531 likewise updated the man page.
2532
2533 13. The limit of 99 on the number of capturing subpatterns has been removed.
2534 The new limit is 65535, which I hope will not be a "real" limit.
2535
2536
2537 Version 3.4 22-Aug-00
2538 ---------------------
2539
2540 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2541
2542 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2543
2544
2545 Version 3.3 01-Aug-00
2546 ---------------------
2547
2548 1. If an octal character was given, but the value was greater than \377, it
2549 was not getting masked to the least significant bits, as documented. This could
2550 lead to crashes in some systems.
2551
2552 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2553 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2554
2555 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2556 These just pass their arguments on to (pcre_free)(), but they are provided
2557 because some uses of PCRE bind it to non-C systems that can call its functions,
2558 but cannot call free() or pcre_free() directly.
2559
2560 4. Add "make test" as a synonym for "make check". Corrected some comments in
2561 the Makefile.
2562
2563 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2564 Makefile.
2565
2566 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2567 command called pgrep for grepping around the active processes.
2568
2569 7. Added the beginnings of support for UTF-8 character strings.
2570
2571 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2572 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2573 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2574 out for the ar command.)
2575
2576
2577 Version 3.2 12-May-00
2578 ---------------------
2579
2580 This is purely a bug fixing release.
2581
2582 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2583 of ZA. This was just one example of several cases that could provoke this bug,
2584 which was introduced by change 9 of version 2.00. The code for breaking
2585 infinite loops after an iteration that matches an empty string was't working
2586 correctly.
2587
2588 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2589 when matched against abbab (for example). After matching an empty string, it
2590 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2591 caused it to match further down the string than it should.
2592
2593 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2594 was there because it doesn't seem to be needed, and it causes trouble on some
2595 systems, as it is not a Standard C header. It has been removed.
2596
2597 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2598 were reported on the Macintosh. The changes were from
2599
2600 while ((c = *(++ptr)) != 0 && c != '\n');
2601 to
2602 while ((c = *(++ptr)) != 0 && c != '\n') ;
2603
2604 Totally extraordinary, but if that's what it takes...
2605
2606 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2607 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2608 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2609 assumes the way PCRE uses memmove() (always moving upwards).
2610
2611 6. PCRE is being used in one environment where strchr() is not available. There
2612 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2613 faster code anyway.
2614
2615
2616 Version 3.1 09-Feb-00
2617 ---------------------
2618
2619 The only change in this release is the fixing of some bugs in Makefile.in for
2620 the "install" target:
2621
2622 (1) It was failing to install pcreposix.h.
2623
2624 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2625
2626
2627 Version 3.0 01-Feb-00
2628 ---------------------
2629
2630 1. Add support for the /+ modifier to perltest (to output $` like it does in
2631 pcretest).
2632
2633 2. Add support for the /g modifier to perltest.
2634
2635 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2636 matches null strings.
2637
2638 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2639 pattern. Perl treats empty patterns specially - it reuses the most recent
2640 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2641 effect.
2642
2643 5. The POSIX interface was broken in that it was just handing over the POSIX
2644 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2645 required a bigger vector, with some working space on the end. This means that
2646 the POSIX wrapper now has to get and free some memory, and copy the results.
2647
2648 6. Added some simple autoconf support, placing the test data and the
2649 documentation in separate directories, re-organizing some of the
2650 information files, and making it build pcre-config (a GNU standard). Also added
2651 libtool support for building PCRE as a shared library, which is now the
2652 default.
2653
2654 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2655 09 are not valid octal constants. Single digits will be used for minor values
2656 less than 10.
2657
2658 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2659 existing programs that set these in the POSIX interface can use PCRE without
2660 modification.
2661
2662 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2663 return all that pcre_info() returns, plus additional data. The pcre_info()
2664 function is retained for compatibility, but is considered to be obsolete.
2665
2666 10. Added experimental recursion feature (?R) to handle one common case that
2667 Perl 5.6 will be able to do with (?p{...}).
2668
2669 11. Added support for POSIX character classes like [:alpha:], which Perl is
2670 adopting.
2671
2672
2673 Version 2.08 31-Aug-99
2674 ----------------------
2675
2676 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2677 trying to match at the startoffset position, but instead was moving forward to
2678 the next newline as if a previous match had failed.
2679
2680 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2681 and could get into a loop if a null string was matched other than at the start
2682 of the subject.
2683
2684 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2685 be distinguished at compile time, and for completeness also added PCRE_DATE.
2686
2687 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2688 in GnuWin32 environments.
2689
2690
2691 Version 2.07 29-Jul-99
2692 ----------------------
2693
2694 1. The documentation is now supplied in plain text form and HTML as well as in
2695 the form of man page sources.
2696
2697 2. C++ compilers don't like assigning (void *) values to other pointer types.
2698 In particular this affects malloc(). Although there is no problem in Standard
2699 C, I've put in casts to keep C++ compilers happy.
2700
2701 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2702 should be (const char *).
2703
2704 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2705 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2706 However, I haven't made this a standard facility. The documentation doesn't
2707 mention it, and the Makefile doesn't support it.
2708
2709 5. The Makefile now contains an "install" target, with editable destinations at
2710 the top of the file. The pcretest program is not installed.
2711
2712 6. pgrep -V now gives the PCRE version number and date.
2713
2714 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2715 causing the entire string to be ignored, instead of just the last character.
2716
2717 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2718 non-matching string, it can take a very, very long time, even for strings of
2719 quite modest length, because of the nested recursion. PCRE now does better in
2720 some of these cases. It does this by remembering the last required literal
2721 character in the pattern, and pre-searching the subject to ensure it is present
2722 before running the real match. In other words, it applies a heuristic to detect
2723 some types of certain failure quickly, and in the above example, if presented
2724 with a string that has no trailing " it gives "no match" very quickly.
2725
2726 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2727 other alternatives are tried instead.
2728
2729
2730 Version 2.06 09-Jun-99
2731 ----------------------
2732
2733 1. Change pcretest's output for amount of store used to show just the code
2734 space, because the remainder (the data block) varies in size between 32-bit and
2735 64-bit systems.
2736
2737 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2738 start matching at. This allows lookbehinds to work when searching for multiple
2739 occurrences in a string.
2740
2741 3. Added additional options to pcretest for testing multiple occurrences:
2742
2743 /+ outputs the rest of the string that follows a match
2744 /g loops for multiple occurrences, using the new startoffset argument
2745 /G loops for multiple occurrences by passing an incremented pointer
2746
2747 4. PCRE wasn't doing the "first character" optimization for patterns starting
2748 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2749 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2750 the letter 'x'. On long subject strings, this gives a significant speed-up.
2751
2752
2753 Version 2.05 21-Apr-99
2754 ----------------------
2755
2756 1. Changed the type of magic_number from int to long int so that it works
2757 properly on 16-bit systems.
2758
2759 2. Fixed a bug which caused patterns starting with .* not to work correctly
2760 when the subject string contained newline characters. PCRE was assuming
2761 anchoring for such patterns in all cases, which is not correct because .* will
2762 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2763 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2764 must be retried after every newline in the subject.
2765
2766
2767 Version 2.04 18-Feb-99
2768 ----------------------
2769
2770 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2771 computation of the store needed to hold the pattern was incorrect (too large).
2772 If such patterns were nested a few deep, this could multiply and become a real
2773 problem.
2774
2775 2. Added /M option to pcretest to show the memory requirement of a specific
2776 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2777
2778 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2779 compiled in such a way that the backtracking after subsequent failure was
2780 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2781 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2782
2783
2784 Version 2.03 02-Feb-99
2785 ----------------------
2786
2787 1. Fixed typo and small mistake in man page.
2788
2789 2. Added 4th condition (GPL supersedes if conflict) and created separate
2790 LICENCE file containing the conditions.
2791
2792 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2793 Perl, that is the internal \ allows the delimiter to be included in the
2794 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2795 the final delimiter, add \ to the end of the pattern (to test the error).
2796
2797 4. Added the convenience functions for extracting substrings after a successful
2798 match. Updated pcretest to make it able to test these functions.
2799
2800
2801 Version 2.02 14-Jan-99
2802 ----------------------
2803
2804 1. Initialized the working variables associated with each extraction so that
2805 their saving and restoring doesn't refer to uninitialized store.
2806
2807 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2808 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2809 fix the problem.
2810
2811 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2812 calls, and wasn't printing the correct value for compiling calls. Increased the
2813 default value of LOOPREPEAT, and the number of significant figures in the
2814 times.
2815
2816 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2817
2818 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2819 a building problem on Windows NT with a FAT file system.
2820
2821
2822 Version 2.01 21-Oct-98
2823 ----------------------
2824
2825 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2826 to character tables built by pcre_maketables() in the current locale. If NULL
2827 is passed, the default tables are used.
2828
2829
2830 Version 2.00 24-Sep-98
2831 ----------------------
2832
2833 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2834 it any more.
2835
2836 2. Allow quantification of (?>) groups, and make it work correctly.
2837
2838 3. The first character computation wasn't working for (?>) groups.
2839
2840 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2841 end of the subject) and add 5.005's \z, which really does match only at the
2842 very end of the subject.
2843
2844 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2845
2846 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2847 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2848 localized options. All options to pcre_study() were also removed.
2849
2850 7. Add other new features from 5.005:
2851
2852 $(?<= positive lookbehind
2853 $(?<! negative lookbehind
2854 (?imsx-imsx) added the unsetting capability
2855 such a setting is global if at outer level; local otherwise
2856 (?imsx-imsx:) non-capturing groups with option setting
2857 (?(cond)re|re) conditional pattern matching
2858
2859 A backreference to itself in a repeated group matches the previous
2860 captured string.
2861
2862 8. General tidying up of studying (both automatic and via "study")
2863 consequential on the addition of new assertions.
2864
2865 9. As in 5.005, unlimited repeated groups that could match an empty substring
2866 are no longer faulted at compile time. Instead, the loop is forcibly broken at
2867 runtime if any iteration does actually match an empty substring.
2868
2869 10. Include the RunTest script in the distribution.
2870
2871 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2872 discrepancies, some of which were old and were also with respect to 5.004. They
2873 have now been fixed.
2874
2875
2876 Version 1.09 28-Apr-98
2877 ----------------------
2878
2879 1. A negated single character class followed by a quantifier with a minimum
2880 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2881 program crashes, or just wrong answers. This did not apply to negated classes
2882 containing more than one character, or to minima other than one.
2883
2884
2885 Version 1.08 27-Mar-98
2886 ----------------------
2887
2888 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2889
2890 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2891 latter must appear before anything that relies on it in the pattern.
2892
2893
2894 Version 1.07 16-Feb-98
2895 ----------------------
2896
2897 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2898 repeat of a potentially empty string).
2899
2900
2901 Version 1.06 23-Jan-98
2902 ----------------------
2903
2904 1. Added Markus Oberhumer's little patches for C++.
2905
2906 2. Literal strings longer than 255 characters were broken.
2907
2908
2909 Version 1.05 23-Dec-97
2910 ----------------------
2911
2912 1. Negated character classes containing more than one character were failing if
2913 PCRE_CASELESS was set at run time.
2914
2915
2916 Version 1.04 19-Dec-97
2917 ----------------------
2918
2919 1. Corrected the man page, where some "const" qualifiers had been omitted.
2920
2921 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2922 input syntax.
2923
2924 3. Fixed memory leak which occurred when a regex with back references was
2925 matched with an offsets vector that wasn't big enough. The temporary memory
2926 that is used in this case wasn't being freed if the match failed.
2927
2928 4. Tidied pcretest to ensure it frees memory that it gets.
2929
2930 5. Temporary memory was being obtained in the case where the passed offsets
2931 vector was exactly big enough.
2932
2933 6. Corrected definition of offsetof() from change 5 below.
2934
2935 7. I had screwed up change 6 below and broken the rules for the use of
2936 setjmp(). Now fixed.
2937
2938
2939 Version 1.03 18-Dec-97
2940 ----------------------
2941
2942 1. A erroneous regex with a missing opening parenthesis was correctly
2943 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2944 on some systems.
2945
2946 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
2947 it was reported that one broken compiler failed on the former because "code" is
2948 also an independent variable.
2949
2950 3. The erroneous regex a[]b caused an array overrun reference.
2951
2952 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
2953 fail on data ending with that character. (It was going on too far, and checking
2954 the next character, typically a binary zero.) This was specific to the
2955 optimized code for single-character negative classes.
2956
2957 5. Added a contributed patch from the TIN world which does the following:
2958
2959 + Add an undef for memmove, in case the the system defines a macro for it.
2960
2961 + Add a definition of offsetof(), in case there isn't one. (I don't know
2962 the reason behind this - offsetof() is part of the ANSI standard - but
2963 it does no harm).
2964
2965 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
2966 most of the places where whitespace preceded '#'. I have given up and
2967 allowed the remaining 2 cases to be at the margin.
2968
2969 + Rename some variables in pcre to eliminate shadowing. This seems very
2970 pedantic, but does no harm, of course.
2971
2972 6. Moved the call to setjmp() into its own function, to get rid of warnings
2973 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
2974
2975 7. Constructs such as \d{8,} were compiling into the equivalent of
2976 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
2977 outcome, but in this particular case used more store than had been allocated,
2978 which caused the bug to be discovered because it threw up an internal error.
2979
2980 8. The debugging code in both pcre and pcretest for outputting the compiled
2981 form of a regex was going wrong in the case of back references followed by
2982 curly-bracketed repeats.
2983
2984
2985 Version 1.02 12-Dec-97
2986 ----------------------
2987
2988 1. Typos in pcre.3 and comments in the source fixed.
2989
2990 2. Applied a contributed patch to get rid of places where it used to remove
2991 'const' from variables, and fixed some signed/unsigned and uninitialized
2992 variable warnings.
2993
2994 3. Added the "runtest" target to Makefile.
2995
2996 4. Set default compiler flag to -O2 rather than just -O.
2997
2998
2999 Version 1.01 19-Nov-97
3000 ----------------------
3001
3002 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3003 like /([ab]*)*/, that is, for classes with more than one character in them.
3004
3005 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3006 as /((?>a*))*/ (a PCRE_EXTRA facility).
3007
3008
3009 Version 1.00 18-Nov-97
3010 ----------------------
3011
3012 1. Added compile-time macros to support systems such as SunOS4 which don't have
3013 memmove() or strerror() but have other things that can be used instead.
3014
3015 2. Arranged that "make clean" removes the executables.
3016
3017
3018 Version 0.99 27-Oct-97
3019 ----------------------
3020
3021 1. Fixed bug in code for optimizing classes with only one character. It was
3022 initializing a 32-byte map regardless, which could cause it to run off the end
3023 of the memory it had got.
3024
3025 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3026
3027
3028 Version 0.98 22-Oct-97
3029 ----------------------
3030
3031 1. Fixed bug in code for handling temporary memory usage when there are more
3032 back references than supplied space in the ovector. This could cause segfaults.
3033
3034
3035 Version 0.97 21-Oct-97
3036 ----------------------
3037
3038 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3039
3040 2. Optimized negated single characters not to use a bit map.
3041
3042 3. Brought error texts together as macro definitions; clarified some of them;
3043 fixed one that was wrong - it said "range out of order" when it meant "invalid
3044 escape sequence".
3045
3046 4. Changed some char * arguments to const char *.
3047
3048 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3049
3050 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3051 pcretest.
3052
3053
3054 Version 0.96 16-Oct-97
3055 ----------------------
3056
3057 1. Added a simple "pgrep" utility to the distribution.
3058
3059 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3060 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3061 where "ddd" means "one or more decimal digits".
3062
3063 3. Fixed serious bug. If a pattern had a back reference, but the call to
3064 pcre_exec() didn't supply a large enough ovector to record the related
3065 identifying subpattern, the match always failed. PCRE now remembers the number
3066 of the largest back reference, and gets some temporary memory in which to save
3067 the offsets during matching if necessary, in order to ensure that
3068 backreferences always work.
3069
3070 4. Increased the compatibility with Perl in a number of ways:
3071
3072 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3073 to request this handling. The option can be set at compile or exec time.
3074
3075 (b) $ matches before a terminating newline by default; an option
3076 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3077 mode). The option can be set at compile or exec time.
3078
3079 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3080 the same as Perl's. If the decimal number it represents is less than 10
3081 or there aren't that many previous left capturing parentheses, an octal
3082 escape is read. Inside a character class, it's always an octal escape,
3083 even if it is a single digit.
3084
3085 (d) An escaped but undefined alphabetic character is taken as a literal,
3086 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3087 escapes.
3088
3089 (e) {0} is now permitted. (The previous item is removed from the compiled
3090 pattern).
3091
3092 5. Changed all the names of code files so that the basic parts are no longer
3093 than 10 characters, and abolished the teeny "globals.c" file.
3094
3095 6. Changed the handling of character classes; they are now done with a 32-byte
3096 bit map always.
3097
3098 7. Added the -d and /D options to pcretest to make it possible to look at the
3099 internals of compilation without having to recompile pcre.
3100
3101
3102 Version 0.95 23-Sep-97
3103 ----------------------
3104
3105 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3106 \x20 at the start of a run of normal characters. These were being treated as
3107 real characters, instead of the source characters being re-checked.
3108
3109
3110 Version 0.94 18-Sep-97
3111 ----------------------
3112
3113 1. The functions are now thread-safe, with the caveat that the global variables
3114 containing pointers to malloc() and free() or alternative functions are the
3115 same for all threads.
3116
3117 2. Get pcre_study() to generate a bitmap of initial characters for non-
3118 anchored patterns when this is possible, and use it if passed to pcre_exec().
3119
3120
3121 Version 0.93 15-Sep-97
3122 ----------------------
3123
3124 1. /(b)|(:+)/ was computing an incorrect first character.
3125
3126 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3127 but not actually doing anything yet.
3128
3129 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3130 as Perl does (e.g. [-az] or [az-]).
3131
3132 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3133 all possible positions.
3134
3135 5. Split up into different modules to avoid including unneeded functions in a
3136 compiled binary. However, compile and exec are still in one module. The "study"
3137 function is split off.
3138
3139 6. The character tables are now in a separate module whose source is generated
3140 by an auxiliary program - but can then be edited by hand if required. There are
3141 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3142 toupper() in the code.
3143
3144 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3145 make them global. Abolish the function for setting them, as the caller can now
3146 set them directly.
3147
3148
3149 Version 0.92 11-Sep-97
3150 ----------------------
3151
3152 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3153 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3154
3155 2. Caseless matching was not working in character classes if the characters in
3156 the pattern were in upper case.
3157
3158 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3159
3160 4. Make PCRE_ANCHORED public and accept as a compile option.
3161
3162 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3163 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3164 pass them.
3165
3166 6. Give an error if bad option bits passed at compile or run time.
3167
3168 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3169 pcretest to cause it to pass that flag.
3170
3171 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3172 options, and the first character, if set.
3173
3174 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3175
3176
3177 Version 0.91 10-Sep-97
3178 ----------------------
3179
3180 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3181 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3182
3183 2. PCRE was looping on encountering an indefinitely repeated back reference to
3184 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3185 Perl does - treats the match as successful.
3186
3187 ****

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