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Revision 358 - (show annotations)
Wed Jul 9 11:03:07 2008 UTC (7 years ago) by ph10
File size: 157645 byte(s)
Error occurred while calculating annotation data.
Comments about stack usage added.
1 ChangeLog for PCRE
2 ------------------
3
4 Version 8.0 02 Jul-08
5 ---------------------
6
7 1. Replaced UCP searching code with optimized version as implemented for Ad
8 Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
9 stage table and inline lookup instead of a function, giving speed ups of 2
10 to 5 times on some simple patterns that I tested. Permission was given to
11 distribute the MultiStage2.py script that generates the tables (it's not in
12 the tarball, but is in the Subversion repository).
13
14 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
15 scripts.
16
17 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
18 a group with a zero qualifier. The result of the study could be incorrect,
19 or the function might crash, depending on the pattern.
20
21 4. Caseless matching was not working for non-ASCII characters in back
22 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23 It now works when Unicode Property Support is available.
24
25 5. In pcretest, an escape such as \x{de} in the data was always generating
26 a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
27 non-UTF-8 mode. If the value is greater than 255, it gives a warning about
28 truncation.
29
30 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
31
32 7. Added two (int) casts to pcregrep when printing the difference of two
33 pointers, in case they are 64-bit values.
34
35 8. Added comments about Mac OS X stack usage to the pcrestack man page and to
36 test 2 if it fails.
37
38
39 Version 7.7 07-May-08
40 ---------------------
41
42 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
43 a string to a long long, pretend we don't even have a long long." This is
44 done by checking for the strtoq, strtoll, and _strtoi64 functions.
45
46 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
47 pre-7.6 versions, which defined a global no_arg variable instead of putting
48 it in the RE class. (See also #8 below.)
49
50 3. Remove a line of dead code, identified by coverity and reported by Nuno
51 Lopes.
52
53 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
54
55 (1) The include/exclude patterns were being applied to the whole pathnames
56 of files, instead of just to the final components.
57
58 (2) If there was more than one level of directory, the subdirectories were
59 skipped unless they satisfied the include/exclude conditions. This is
60 inconsistent with GNU grep (and could even be seen as contrary to the
61 pcregrep specification - which I improved to make it absolutely clear).
62 The action now is always to scan all levels of directory, and just
63 apply the include/exclude patterns to regular files.
64
65 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
66 --exclude_dir in the tests to avoid scanning .svn directories.
67
68 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
69 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
70 doesn't support NULs in patterns.
71
72 7. Added some missing "const"s to declarations of static tables in
73 pcre_compile.c and pcre_dfa_exec.c.
74
75 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
76 caused by fix #2 above. (Subsequently also a second patch to fix the
77 first patch. And a third patch - this was a messy problem.)
78
79 9. Applied Craig's patch to remove the use of push_back().
80
81 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
82 matching function regexec().
83
84 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
85 which, however, unlike Perl's \g{...}, are subroutine calls, not back
86 references. PCRE supports relative numbers with this syntax (I don't think
87 Oniguruma does).
88
89 12. Previously, a group with a zero repeat such as (...){0} was completely
90 omitted from the compiled regex. However, this means that if the group
91 was called as a subroutine from elsewhere in the pattern, things went wrong
92 (an internal error was given). Such groups are now left in the compiled
93 pattern, with a new opcode that causes them to be skipped at execution
94 time.
95
96 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
97 to the way PCRE behaves:
98
99 (a) A lone ] character is dis-allowed (Perl treats it as data).
100
101 (b) A back reference to an unmatched subpattern matches an empty string
102 (Perl fails the current match path).
103
104 (c) A data ] in a character class must be notated as \] because if the
105 first data character in a class is ], it defines an empty class. (In
106 Perl it is not possible to have an empty class.) The empty class []
107 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
108 The negative empty class [^] matches any one character, independently
109 of the DOTALL setting.
110
111 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
112 non-existent subpattern following a character class starting with ']' and
113 containing () gave an internal compiling error instead of "reference to
114 non-existent subpattern". Fortunately, when the pattern did exist, the
115 compiled code was correct. (When scanning forwards to check for the
116 existencd of the subpattern, it was treating the data ']' as terminating
117 the class, so got the count wrong. When actually compiling, the reference
118 was subsequently set up correctly.)
119
120 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
121 it was being rejected as not supported by pcre_dfa_exec(), even though
122 other assertions are supported. I have made pcre_dfa_exec() support
123 (*FAIL).
124
125 16. The implementation of 13c above involved the invention of a new opcode,
126 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
127 cannot be changed at match time, I realized I could make a small
128 improvement to matching performance by compiling OP_ALLANY instead of
129 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
130 on the OP_ANY path.
131
132 17. Compiling pcretest on Windows with readline support failed without the
133 following two fixes: (1) Make the unistd.h include conditional on
134 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
135
136 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
137 ncurses library to be included for pcretest when ReadLine support is
138 requested, but also to allow for it to be overridden. This patch came from
139 Daniel Bergström.
140
141 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
142 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
143 any errors with the current Unicode tables. Thanks to Peter Kankowski for
144 spotting this.
145
146
147 Version 7.6 28-Jan-08
148 ---------------------
149
150 1. A character class containing a very large number of characters with
151 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
152 overflow.
153
154 2. Patch to cut out the "long long" test in pcrecpp_unittest when
155 HAVE_LONG_LONG is not defined.
156
157 3. Applied Christian Ehrlicher's patch to update the CMake build files to
158 bring them up to date and include new features. This patch includes:
159
160 - Fixed PH's badly added libz and libbz2 support.
161 - Fixed a problem with static linking.
162 - Added pcredemo. [But later removed - see 7 below.]
163 - Fixed dftables problem and added an option.
164 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
165 HAVE_LONG_LONG.
166 - Added readline support for pcretest.
167 - Added an listing of the option settings after cmake has run.
168
169 4. A user submitted a patch to Makefile that makes it easy to create
170 "pcre.dll" under mingw when using Configure/Make. I added stuff to
171 Makefile.am that cause it to include this special target, without
172 affecting anything else. Note that the same mingw target plus all
173 the other distribution libraries and programs are now supported
174 when configuring with CMake (see 6 below) instead of with
175 Configure/Make.
176
177 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
178 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
179 exported in the Windows port". It has not yet been confirmed that the patch
180 solves the problem, but it does no harm.
181
182 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
183 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
184 with CMake, and also correct the comment about stack recursion.
185
186 7. Remove the automatic building of pcredemo from the ./configure system and
187 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
188 of a program that users should build themselves after PCRE is installed, so
189 building it automatically is not really right. What is more, it gave
190 trouble in some build environments.
191
192 8. Further tidies to CMakeLists.txt from Sheri and Christian.
193
194
195 Version 7.5 10-Jan-08
196 ---------------------
197
198 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
199 values in parens when parsing an RE using the C++ wrapper."
200
201 2. Negative specials like \S did not work in character classes in UTF-8 mode.
202 Characters greater than 255 were excluded from the class instead of being
203 included.
204
205 3. The same bug as (2) above applied to negated POSIX classes such as
206 [:^space:].
207
208 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
209 defined or documented. It seems to have been a typo for PCRE_STATIC, so
210 I have changed it.
211
212 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
213 first named subpattern) and a construct such as (?&a) would reference the
214 first named subpattern whose name started with "a" (in other words, the
215 length check was missing). Both these problems are fixed. "Subpattern name
216 expected" is now given for (?&) (a zero-length name), and this patch also
217 makes it give the same error for \k'' (previously it complained that that
218 was a reference to a non-existent subpattern).
219
220 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
221 this is right because (?- can be followed by option settings as well as by
222 digits. I have, however, made the messages clearer.
223
224 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
225 than the number used in the conditional) now cause a compile-time error.
226 This is actually not compatible with Perl, which accepts such patterns, but
227 treats the conditional as always being FALSE (as PCRE used to), but it
228 seems to me that giving a diagnostic is better.
229
230 8. Change "alphameric" to the more common word "alphanumeric" in comments
231 and messages.
232
233 9. Fix two occurrences of "backslash" in comments that should have been
234 "backspace".
235
236 10. Remove two redundant lines of code that can never be obeyed (their function
237 was moved elsewhere).
238
239 11. The program that makes PCRE's Unicode character property table had a bug
240 which caused it to generate incorrect table entries for sequences of
241 characters that have the same character type, but are in different scripts.
242 It amalgamated them into a single range, with the script of the first of
243 them. In other words, some characters were in the wrong script. There were
244 thirteen such cases, affecting characters in the following ranges:
245
246 U+002b0 - U+002c1
247 U+0060c - U+0060d
248 U+0061e - U+00612
249 U+0064b - U+0065e
250 U+0074d - U+0076d
251 U+01800 - U+01805
252 U+01d00 - U+01d77
253 U+01d9b - U+01dbf
254 U+0200b - U+0200f
255 U+030fc - U+030fe
256 U+03260 - U+0327f
257 U+0fb46 - U+0fbb1
258 U+10450 - U+1049d
259
260 12. The -o option (show only the matching part of a line) for pcregrep was not
261 compatible with GNU grep in that, if there was more than one match in a
262 line, it showed only the first of them. It now behaves in the same way as
263 GNU grep.
264
265 13. If the -o and -v options were combined for pcregrep, it printed a blank
266 line for every non-matching line. GNU grep prints nothing, and pcregrep now
267 does the same. The return code can be used to tell if there were any
268 non-matching lines.
269
270 14. Added --file-offsets and --line-offsets to pcregrep.
271
272 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
273 infinitely looping recursion. The bug was that positive lookaheads were not
274 being skipped when checking for a possible empty match (negative lookaheads
275 and both kinds of lookbehind were skipped).
276
277 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
278 inclusion of <windows.h> to before rather than after the definition of
279 INVALID_FILE_ATTRIBUTES (patch from David Byron).
280
281 17. Specifying a possessive quantifier with a specific limit for a Unicode
282 character property caused pcre_compile() to compile bad code, which led at
283 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
284 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
285 caused the error; without that there was no problem.
286
287 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
288
289 19. Added --enable-pcretest-libreadline.
290
291 20. In pcrecpp.cc, the variable 'count' was incremented twice in
292 RE::GlobalReplace(). As a result, the number of replacements returned was
293 double what it should be. I removed one of the increments, but Craig sent a
294 later patch that removed the other one (the right fix) and added unit tests
295 that check the return values (which was not done before).
296
297 21. Several CMake things:
298
299 (1) Arranged that, when cmake is used on Unix, the libraries end up with
300 the names libpcre and libpcreposix, not just pcre and pcreposix.
301
302 (2) The above change means that pcretest and pcregrep are now correctly
303 linked with the newly-built libraries, not previously installed ones.
304
305 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
306
307 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
308 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
309 UTF-8 newline character). The key issue is that the pattern starts .*;
310 this means that the match must be either at the beginning, or after a
311 newline. The bug was in the code for advancing after a failed match and
312 checking that the new position followed a newline. It was not taking
313 account of UTF-8 characters correctly.
314
315 23. PCRE was behaving differently from Perl in the way it recognized POSIX
316 character classes. PCRE was not treating the sequence [:...:] as a
317 character class unless the ... were all letters. Perl, however, seems to
318 allow any characters between [: and :], though of course it rejects as
319 unknown any "names" that contain non-letters, because all the known class
320 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
321 for example, whereas PCRE did not - it did not recognize a POSIX character
322 class. This seemed a bit dangerous, so the code has been changed to be
323 closer to Perl. The behaviour is not identical to Perl, because PCRE will
324 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
325 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
326 Perl does, and where it didn't before.
327
328 24. Rewrite so as to remove the single use of %n from pcregrep because in some
329 Windows environments %n is disabled by default.
330
331
332 Version 7.4 21-Sep-07
333 ---------------------
334
335 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
336 means that a class such as [\s] counted as "explicit reference to CR or
337 LF". That isn't really right - the whole point of the change was to try to
338 help when there was an actual mention of one of the two characters. So now
339 the change happens only if \r or \n (or a literal CR or LF) character is
340 encountered.
341
342 2. The 32-bit options word was also used for 6 internal flags, but the numbers
343 of both had grown to the point where there were only 3 bits left.
344 Fortunately, there was spare space in the data structure, and so I have
345 moved the internal flags into a new 16-bit field to free up more option
346 bits.
347
348 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
349 but did not set the internal JCHANGED flag - either of these is enough to
350 control the way the "get" function works - but the PCRE_INFO_JCHANGED
351 facility is supposed to tell if (?J) was ever used, so now (?J) at the
352 start sets both bits.
353
354 4. Added options (at build time, compile time, exec time) to change \R from
355 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
356
357 5. doc/pcresyntax.html was missing from the distribution.
358
359 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
360 compatibility, even though it is no longer used.
361
362 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
363 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
364 windows.h file is present (where different names are used). [This was
365 reversed later after testing - see 16 below.]
366
367 8. Changed all #include <config.h> to #include "config.h". There were also
368 some further <pcre.h> cases that I changed to "pcre.h".
369
370 9. When pcregrep was used with the --colour option, it missed the line ending
371 sequence off the lines that it output.
372
373 10. It was pointed out to me that arrays of string pointers cause lots of
374 relocations when a shared library is dynamically loaded. A technique of
375 using a single long string with a table of offsets can drastically reduce
376 these. I have refactored PCRE in four places to do this. The result is
377 dramatic:
378
379 Originally: 290
380 After changing UCP table: 187
381 After changing error message table: 43
382 After changing table of "verbs" 36
383 After changing table of Posix names 22
384
385 Thanks to the folks working on Gregex for glib for this insight.
386
387 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
388 unicode-properties was also set.
389
390 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
391
392 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
393 checked only for CRLF.
394
395 14. Added casts to pcretest.c to avoid compiler warnings.
396
397 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
398
399 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
400 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
401 entirely. This removes changes made in 7 above.
402
403 17. The CMake files have been updated, and there is now more information about
404 building with CMake in the NON-UNIX-USE document.
405
406
407 Version 7.3 28-Aug-07
408 ---------------------
409
410 1. In the rejigging of the build system that eventually resulted in 7.1, the
411 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
412 brackets there is not right, since it causes compilers to look for an
413 installed pcre.h, not the version that is in the source that is being
414 compiled (which of course may be different). I have changed it back to:
415
416 #include "pcre.h"
417
418 I have a vague recollection that the change was concerned with compiling in
419 different directories, but in the new build system, that is taken care of
420 by the VPATH setting the Makefile.
421
422 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
423 when the subject happened to end in the byte 0x85 (e.g. if the last
424 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
425 characters but of course it shouldn't be taken as a newline when it is part
426 of another character. The bug was that, for an unlimited repeat of . in
427 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
428 characters when looking for a newline.
429
430 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
431
432 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
433 in debug output.
434
435 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
436 long printing in the pcrecpp unittest when running under MinGW.
437
438 6. ESC_K was left out of the EBCDIC table.
439
440 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
441 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
442 limit also applies to "virtual nesting" when a pattern is recursive, and in
443 this case 1000 isn't so big. I have been able to remove this limit at the
444 expense of backing off one optimization in certain circumstances. Normally,
445 when pcre_exec() would call its internal match() function recursively and
446 immediately return the result unconditionally, it uses a "tail recursion"
447 feature to save stack. However, when a subpattern that can match an empty
448 string has an unlimited repetition quantifier, it no longer makes this
449 optimization. That gives it a stack frame in which to save the data for
450 checking that an empty string has been matched. Previously this was taken
451 from the 1000-entry workspace that had been reserved. So now there is no
452 explicit limit, but more stack is used.
453
454 8. Applied Daniel's patches to solve problems with the import/export magic
455 syntax that is required for Windows, and which was going wrong for the
456 pcreposix and pcrecpp parts of the library. These were overlooked when this
457 problem was solved for the main library.
458
459 9. There were some crude static tests to avoid integer overflow when computing
460 the size of patterns that contain repeated groups with explicit upper
461 limits. As the maximum quantifier is 65535, the maximum group length was
462 set at 30,000 so that the product of these two numbers did not overflow a
463 32-bit integer. However, it turns out that people want to use groups that
464 are longer than 30,000 bytes (though not repeat them that many times).
465 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
466 made it possible to implement the integer overflow checks in a much more
467 dynamic way, which I have now done. The artificial limitation on group
468 length has been removed - we now have only the limit on the total length of
469 the compiled pattern, which depends on the LINK_SIZE setting.
470
471 10. Fixed a bug in the documentation for get/copy named substring when
472 duplicate names are permitted. If none of the named substrings are set, the
473 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
474 empty string.
475
476 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
477 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
478 because the ] is interpreted as the first data character and the
479 terminating ] is not found. PCRE has been made compatible with Perl in this
480 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
481 cause memory overwriting.
482
483 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
484 string has been matched (to stop an infinite loop). It was not recognizing
485 a conditional subpattern that could match an empty string if that
486 subpattern was within another subpattern. For example, it looped when
487 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
488 condition was not nested. This bug has been fixed.
489
490 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
491 past the start of the subject in the presence of bytes with the top bit
492 set, for example "\x8aBCD".
493
494 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
495 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
496
497 14. Optimized (?!) to (*FAIL).
498
499 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
500 This restricts code points to be within the range 0 to 0x10FFFF, excluding
501 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
502 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
503 does: it's just the validity check that is more restrictive.
504
505 16. Inserted checks for integer overflows during escape sequence (backslash)
506 processing, and also fixed erroneous offset values for syntax errors during
507 backslash processing.
508
509 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
510 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
511
512 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
513 caused an overrun.
514
515 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
516 something other than just ASCII characters) inside a group that had an
517 unlimited repeat caused a loop at compile time (while checking to see
518 whether the group could match an empty string).
519
520 20. Debugging a pattern containing \p or \P could cause a crash. For example,
521 [\P{Any}] did so. (Error in the code for printing property names.)
522
523 21. An orphan \E inside a character class could cause a crash.
524
525 22. A repeated capturing bracket such as (A)? could cause a wild memory
526 reference during compilation.
527
528 23. There are several functions in pcre_compile() that scan along a compiled
529 expression for various reasons (e.g. to see if it's fixed length for look
530 behind). There were bugs in these functions when a repeated \p or \P was
531 present in the pattern. These operators have additional parameters compared
532 with \d, etc, and these were not being taken into account when moving along
533 the compiled data. Specifically:
534
535 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
536 length.
537
538 (b) An item such as \pL+ within a repeated group could cause crashes or
539 loops.
540
541 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
542 "reference to non-existent subpattern" error.
543
544 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
545
546 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
547 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
548
549 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
550
551 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
552 character were causing crashes (broken optimization).
553
554 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
555 \p or \P) caused a compile-time loop.
556
557 28. More problems have arisen in unanchored patterns when CRLF is a valid line
558 break. For example, the unstudied pattern [\r\n]A does not match the string
559 "\r\nA" because change 7.0/46 below moves the current point on by two
560 characters after failing to match at the start. However, the pattern \nA
561 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
562 the same is true. There doesn't seem any very clean way out of this, but
563 what I have chosen to do makes the common cases work: PCRE now takes note
564 of whether there can be an explicit match for \r or \n anywhere in the
565 pattern, and if so, 7.0/46 no longer applies. As part of this change,
566 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
567 pattern has explicit CR or LF references.
568
569 29. Added (*CR) etc for changing newline setting at start of pattern.
570
571
572 Version 7.2 19-Jun-07
573 ---------------------
574
575 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
576 which is apparently normally available under Windows.
577
578 2. Re-jig the pcregrep tests with different newline settings in an attempt
579 to make them independent of the local environment's newline setting.
580
581 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
582
583 4. Some of the "internals" tests were previously cut out when the link size
584 was not 2, because the output contained actual offsets. The recent new
585 "Z" feature of pcretest means that these can be cut out, making the tests
586 usable with all link sizes.
587
588 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
589 stack recursion. This gives a massive performance boost under BSD, but just
590 a small improvement under Linux. However, it saves one field in the frame
591 in all cases.
592
593 6. Added more features from the forthcoming Perl 5.10:
594
595 (a) (?-n) (where n is a string of digits) is a relative subroutine or
596 recursion call. It refers to the nth most recently opened parentheses.
597
598 (b) (?+n) is also a relative subroutine call; it refers to the nth next
599 to be opened parentheses.
600
601 (c) Conditions that refer to capturing parentheses can be specified
602 relatively, for example, (?(-2)... or (?(+3)...
603
604 (d) \K resets the start of the current match so that everything before
605 is not part of it.
606
607 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
608
609 (f) \g{name} is another synonym - part of Perl 5.10's unification of
610 reference syntax.
611
612 (g) (?| introduces a group in which the numbering of parentheses in each
613 alternative starts with the same number.
614
615 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
616
617 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
618 PCRE_INFO_JCHANGED.
619
620 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
621 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
622 for detecting groups that can match an empty string.
623
624 9. A pattern with a very large number of alternatives (more than several
625 hundred) was running out of internal workspace during the pre-compile
626 phase, where pcre_compile() figures out how much memory will be needed. A
627 bit of new cunning has reduced the workspace needed for groups with
628 alternatives. The 1000-alternative test pattern now uses 12 bytes of
629 workspace instead of running out of the 4096 that are available.
630
631 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
632
633 11. Applied patch from Google to remove an optimization that didn't quite work.
634 The report of the bug said:
635
636 pcrecpp::RE("a*").FullMatch("aaa") matches, while
637 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
638 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
639
640 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
641 it matched the wrong number of bytes.
642
643
644 Version 7.1 24-Apr-07
645 ---------------------
646
647 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
648 that is more "standard", making use of automake and other Autotools. There
649 is some re-arrangement of the files and adjustment of comments consequent
650 on this.
651
652 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
653 for recursive directory scanning broke on some systems because the files
654 are not scanned in any specific order and on different systems the order
655 was different. A call to "sort" has been inserted into RunGrepTest for the
656 approprate test as a short-term fix. In the longer term there may be an
657 alternative.
658
659 3. I had an email from Eric Raymond about problems translating some of PCRE's
660 man pages to HTML (despite the fact that I distribute HTML pages, some
661 people do their own conversions for various reasons). The problems
662 concerned the use of low-level troff macros .br and .in. I have therefore
663 removed all such uses from the man pages (some were redundant, some could
664 be replaced by .nf/.fi pairs). The 132html script that I use to generate
665 HTML has been updated to handle .nf/.fi and to complain if it encounters
666 .br or .in.
667
668 4. Updated comments in configure.ac that get placed in config.h.in and also
669 arranged for config.h to be included in the distribution, with the name
670 config.h.generic, for the benefit of those who have to compile without
671 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
672
673 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
674 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
675 makevp.bat for the current PCRE, using the additional files
676 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
677
678 6. A Windows user reported a minor discrepancy with test 2, which turned out
679 to be caused by a trailing space on an input line that had got lost in his
680 copy. The trailing space was an accident, so I've just removed it.
681
682 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
683 that is needed.
684
685 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
686 as "const" (a) because they are and (b) because it helps the PHP
687 maintainers who have recently made a script to detect big data structures
688 in the php code that should be moved to the .rodata section. I remembered
689 to update Builducptable as well, so it won't revert if ucptable.h is ever
690 re-created.
691
692 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
693 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
694 order to be able to cut out the UTF-8 tables in the latter when UTF-8
695 support is not required. This saves 1.5-2K of code, which is important in
696 some applications.
697
698 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
699 so as not to refer to the tables, even though these functions will never be
700 called when UTF-8 support is disabled. Otherwise there are problems with a
701 shared library.
702
703 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
704
705 (a) It was defining its arguments as char * instead of void *.
706
707 (b) It was assuming that all moves were upwards in memory; this was true
708 a long time ago when I wrote it, but is no longer the case.
709
710 The emulated memove() is provided for those environments that have neither
711 memmove() nor bcopy(). I didn't think anyone used it these days, but that
712 is clearly not the case, as these two bugs were recently reported.
713
714 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
715 and Detrail to create the HTML documentation, the .txt form of the man
716 pages, and it removes trailing spaces from listed files. It also creates
717 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
718 case, it wraps all the #defines with #ifndefs. This script should be run
719 before "make dist".
720
721 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
722 with Unicode property support.
723
724 (a) For a maximizing quantifier, if the two different cases of the
725 character were of different lengths in their UTF-8 codings (there are
726 some cases like this - I found 11), and the matching function had to
727 back up over a mixture of the two cases, it incorrectly assumed they
728 were both the same length.
729
730 (b) When PCRE was configured to use the heap rather than the stack for
731 recursion during matching, it was not correctly preserving the data for
732 the other case of a UTF-8 character when checking ahead for a match
733 while processing a minimizing repeat. If the check also involved
734 matching a wide character, but failed, corruption could cause an
735 erroneous result when trying to check for a repeat of the original
736 character.
737
738 13. Some tidying changes to the testing mechanism:
739
740 (a) The RunTest script now detects the internal link size and whether there
741 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
742 values substituted by "configure". (The RunGrepTest script already did
743 this for UTF-8.) The configure.ac script no longer substitutes the
744 relevant variables.
745
746 (b) The debugging options /B and /D in pcretest show the compiled bytecode
747 with length and offset values. This means that the output is different
748 for different internal link sizes. Test 2 is skipped for link sizes
749 other than 2 because of this, bypassing the problem. Unfortunately,
750 there was also a test in test 3 (the locale tests) that used /B and
751 failed for link sizes other than 2. Rather than cut the whole test out,
752 I have added a new /Z option to pcretest that replaces the length and
753 offset values with spaces. This is now used to make test 3 independent
754 of link size. (Test 2 will be tidied up later.)
755
756 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
757 segmentation fault instead of returning the appropriate error message.
758
759 15. In multiline mode when the newline sequence was set to "any", the pattern
760 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
761 This doesn't seem right; it now treats the CRLF combination as the line
762 ending, and so does not match in that case. It's only a pattern such as ^$
763 that would hit this one: something like ^ABC$ would have failed after \r
764 and then tried again after \r\n.
765
766 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
767 in an attempt to make files that differ only in their line terminators
768 compare equal. This works on Linux.
769
770 17. Under certain error circumstances pcregrep might try to free random memory
771 as it exited. This is now fixed, thanks to valgrind.
772
773 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
774 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
775 was because its rules for how to advance for /g after matching an empty
776 string at the end of a line did not allow for this case. They now check for
777 it specially.
778
779 20. pcretest is supposed to handle patterns and data of any length, by
780 extending its buffers when necessary. It was getting this wrong when the
781 buffer for a data line had to be extended.
782
783 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
784 CRLF as a newline sequence.
785
786 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
787 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
788 I have nevertheless tidied it up.
789
790 23. Added some casts to kill warnings from HP-UX ia64 compiler.
791
792 24. Added a man page for pcre-config.
793
794
795 Version 7.0 19-Dec-06
796 ---------------------
797
798 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
799 moving to gcc 4.1.1.
800
801 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
802 sys/time.h, which is documented as needed for this function. It doesn't
803 seem to matter on Linux, but it showed up on some releases of OS X.
804
805 3. It seems that there are systems where bytes whose values are greater than
806 127 match isprint() in the "C" locale. The "C" locale should be the
807 default when a C program starts up. In most systems, only ASCII printing
808 characters match isprint(). This difference caused the output from pcretest
809 to vary, making some of the tests fail. I have changed pcretest so that:
810
811 (a) When it is outputting text in the compiled version of a pattern, bytes
812 other than 32-126 are always shown as hex escapes.
813
814 (b) When it is outputting text that is a matched part of a subject string,
815 it does the same, unless a different locale has been set for the match
816 (using the /L modifier). In this case, it uses isprint() to decide.
817
818 4. Fixed a major bug that caused incorrect computation of the amount of memory
819 required for a compiled pattern when options that changed within the
820 pattern affected the logic of the preliminary scan that determines the
821 length. The relevant options are -x, and -i in UTF-8 mode. The result was
822 that the computed length was too small. The symptoms of this bug were
823 either the PCRE error "internal error: code overflow" from pcre_compile(),
824 or a glibc crash with a message such as "pcretest: free(): invalid next
825 size (fast)". Examples of patterns that provoked this bug (shown in
826 pcretest format) are:
827
828 /(?-x: )/x
829 /(?x)(?-x: \s*#\s*)/
830 /((?i)[\x{c0}])/8
831 /(?i:[\x{c0}])/8
832
833 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
834 is now done differently.
835
836 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
837 wrapper classes; (b) implement a new function in the C++ scanner that is
838 more efficient than the old way of doing things because it avoids levels of
839 recursion in the regex matching; (c) add a paragraph to the documentation
840 for the FullMatch() function.
841
842 6. The escape sequence \n was being treated as whatever was defined as
843 "newline". Not only was this contrary to the documentation, which states
844 that \n is character 10 (hex 0A), but it also went horribly wrong when
845 "newline" was defined as CRLF. This has been fixed.
846
847 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
848 was being set to -1 for the "end of line" case (supposedly a value that no
849 character can have). Though this value is never used (the check for end of
850 line is "zero bytes in current character"), it caused compiler complaints.
851 I've changed it to 0xffffffff.
852
853 8. In pcre_version.c, the version string was being built by a sequence of
854 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
855 string (as it is for production releases) called a macro with an empty
856 argument. The C standard says the result of this is undefined. The gcc
857 compiler treats it as an empty string (which was what was wanted) but it is
858 reported that Visual C gives an error. The source has been hacked around to
859 avoid this problem.
860
861 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
862 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
863 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
864 of them did).
865
866 10. Originally, pcretest opened its input and output without "b"; then I was
867 told that "b" was needed in some environments, so it was added for release
868 5.0 to both the input and output. (It makes no difference on Unix-like
869 systems.) Later I was told that it is wrong for the input on Windows. I've
870 now abstracted the modes into two macros, to make it easier to fiddle with
871 them, and removed "b" from the input mode under Windows.
872
873 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
874
875 12. Added -help and --help to pcretest as an official way of being reminded
876 of the options.
877
878 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
879 and pcrecpp.cc because they annoy compilers at high warning levels.
880
881 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
882
883 15. Fixed an occurrence of == in configure.ac that should have been = (shell
884 scripts are not C programs :-) and which was not noticed because it works
885 on Linux.
886
887 16. pcretest is supposed to handle any length of pattern and data line (as one
888 line or as a continued sequence of lines) by extending its input buffer if
889 necessary. This feature was broken for very long pattern lines, leading to
890 a string of junk being passed to pcre_compile() if the pattern was longer
891 than about 50K.
892
893 17. I have done a major re-factoring of the way pcre_compile() computes the
894 amount of memory needed for a compiled pattern. Previously, there was code
895 that made a preliminary scan of the pattern in order to do this. That was
896 OK when PCRE was new, but as the facilities have expanded, it has become
897 harder and harder to keep it in step with the real compile phase, and there
898 have been a number of bugs (see for example, 4 above). I have now found a
899 cunning way of running the real compile function in a "fake" mode that
900 enables it to compute how much memory it would need, while actually only
901 ever using a few hundred bytes of working memory and without too many
902 tests of the mode. This should make future maintenance and development
903 easier. A side effect of this work is that the limit of 200 on the nesting
904 depth of parentheses has been removed (though this was never a serious
905 limitation, I suspect). However, there is a downside: pcre_compile() now
906 runs more slowly than before (30% or more, depending on the pattern). I
907 hope this isn't a big issue. There is no effect on runtime performance.
908
909 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
910 newline (only possible for the last line of a file) and it was a
911 pattern that set a locale (followed by /Lsomething), pcretest crashed.
912
913 19. Added additional timing features to pcretest. (1) The -tm option now times
914 matching only, not compiling. (2) Both -t and -tm can be followed, as a
915 separate command line item, by a number that specifies the number of
916 repeats to use when timing. The default is 50000; this gives better
917 precision, but takes uncomfortably long for very large patterns.
918
919 20. Extended pcre_study() to be more clever in cases where a branch of a
920 subpattern has no definite first character. For example, (a*|b*)[cd] would
921 previously give no result from pcre_study(). Now it recognizes that the
922 first character must be a, b, c, or d.
923
924 21. There was an incorrect error "recursive call could loop indefinitely" if
925 a subpattern (or the entire pattern) that was being tested for matching an
926 empty string contained only one non-empty item after a nested subpattern.
927 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
928 incorrectly, because the \d was being skipped in the check.
929
930 22. The pcretest program now has a new pattern option /B and a command line
931 option -b, which is equivalent to adding /B to every pattern. This causes
932 it to show the compiled bytecode, without the additional information that
933 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
934 is the same as /B/I).
935
936 23. A new optimization is now able automatically to treat some sequences such
937 as a*b as a*+b. More specifically, if something simple (such as a character
938 or a simple class like \d) has an unlimited quantifier, and is followed by
939 something that cannot possibly match the quantified thing, the quantifier
940 is automatically "possessified".
941
942 24. A recursive reference to a subpattern whose number was greater than 39
943 went wrong under certain circumstances in UTF-8 mode. This bug could also
944 have affected the operation of pcre_study().
945
946 25. Realized that a little bit of performance could be had by replacing
947 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
948
949 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
950
951 27. Possessive quantifiers such as a++ were previously implemented by turning
952 them into atomic groups such as ($>a+). Now they have their own opcodes,
953 which improves performance. This includes the automatically created ones
954 from 23 above.
955
956 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
957 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
958 the first matched character to be a colon. This applied both to named and
959 numbered groups.
960
961 29. The ucpinternal.h header file was missing its idempotency #ifdef.
962
963 30. I was sent a "project" file called libpcre.a.dev which I understand makes
964 building PCRE on Windows easier, so I have included it in the distribution.
965
966 31. There is now a check in pcretest against a ridiculously large number being
967 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
968 loop, the loop is abandoned.
969
970 32. Forward references to subpatterns in conditions such as (?(2)...) where
971 subpattern 2 is defined later cause pcre_compile() to search forwards in
972 the pattern for the relevant set of parentheses. This search went wrong
973 when there were unescaped parentheses in a character class, parentheses
974 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
975
976 33. "Subroutine" calls and backreferences were previously restricted to
977 referencing subpatterns earlier in the regex. This restriction has now
978 been removed.
979
980 34. Added a number of extra features that are going to be in Perl 5.10. On the
981 whole, these are just syntactic alternatives for features that PCRE had
982 previously implemented using the Python syntax or my own invention. The
983 other formats are all retained for compatibility.
984
985 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
986 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
987 also .NET compatible.
988
989 (b) A recursion or subroutine call to a named group can now be defined as
990 (?&name) as well as (?P>name).
991
992 (c) A backreference to a named group can now be defined as \k<name> or
993 \k'name' as well as (?P=name). The new forms, as well as being in Perl
994 5.10, are also .NET compatible.
995
996 (d) A conditional reference to a named group can now use the syntax
997 (?(<name>) or (?('name') as well as (?(name).
998
999 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1000 groups (named and numbered) that are never evaluated inline, but can be
1001 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1002 is always false. There may be only one alternative in such a group.
1003
1004 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1005 as the simple (?(R). The condition is true only if the most recent
1006 recursion is that of the given number or name. It does not search out
1007 through the entire recursion stack.
1008
1009 (g) The escape \gN or \g{N} has been added, where N is a positive or
1010 negative number, specifying an absolute or relative reference.
1011
1012 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1013 some "unreachable code" warnings.
1014
1015 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1016 things, this adds five new scripts.
1017
1018 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1019 There were also incompatibilities regarding the handling of \Q..\E inside
1020 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1021 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1022
1023 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1024 matches an empty string, and forcibly breaks the loop. There were bugs in
1025 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1026 against aaaa the result was just "a" rather than "aaaa", for example. Two
1027 separate and independent bugs (that affected different cases) have been
1028 fixed.
1029
1030 39. Refactored the code to abolish the use of different opcodes for small
1031 capturing bracket numbers. This is a tidy that I avoided doing when I
1032 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1033 The new approach is not only tidier, it makes it possible to reduce the
1034 memory needed to fix the previous bug (38).
1035
1036 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1037 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1038 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1039 mode.
1040
1041 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1042 report.
1043
1044 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1045 copy construction and assignment in the C++ wrapper.
1046
1047 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1048 couple of bugs that could have given wrong results in the "--newline=crlf"
1049 case.
1050
1051 44. Added a number of casts and did some reorganization of signed/unsigned int
1052 variables following suggestions from Dair Grant. Also renamed the variable
1053 "this" as "item" because it is a C++ keyword.
1054
1055 45. Arranged for dftables to add
1056
1057 #include "pcre_internal.h"
1058
1059 to pcre_chartables.c because without it, gcc 4.x may remove the array
1060 definition from the final binary if PCRE is built into a static library and
1061 dead code stripping is activated.
1062
1063 46. For an unanchored pattern, if a match attempt fails at the start of a
1064 newline sequence, and the newline setting is CRLF or ANY, and the next two
1065 characters are CRLF, advance by two characters instead of one.
1066
1067
1068 Version 6.7 04-Jul-06
1069 ---------------------
1070
1071 1. In order to handle tests when input lines are enormously long, pcretest has
1072 been re-factored so that it automatically extends its buffers when
1073 necessary. The code is crude, but this _is_ just a test program. The
1074 default size has been increased from 32K to 50K.
1075
1076 2. The code in pcre_study() was using the value of the re argument before
1077 testing it for NULL. (Of course, in any sensible call of the function, it
1078 won't be NULL.)
1079
1080 3. The memmove() emulation function in pcre_internal.h, which is used on
1081 systems that lack both memmove() and bcopy() - that is, hardly ever -
1082 was missing a "static" storage class specifier.
1083
1084 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1085 containing an extended class (one that cannot be represented by a bitmap
1086 because it contains high-valued characters or Unicode property items, e.g.
1087 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1088 pattern, but PCRE should not loop if you do not (it no longer does).
1089 [Detail: two cases were found: (a) a repeated subpattern containing an
1090 extended class; (b) a recursive reference to a subpattern that followed a
1091 previous extended class. It wasn't skipping over the extended class
1092 correctly when UTF-8 mode was not set.]
1093
1094 5. A negated single-character class was not being recognized as fixed-length
1095 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1096 compile error "lookbehind assertion is not fixed length".
1097
1098 6. The RunPerlTest auxiliary script was showing an unexpected difference
1099 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1100 write a Perl script that can interpret lines of an input file either as
1101 byte characters or as UTF-8, which is what "perltest" was being required to
1102 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1103 can't do is switch easily at run time between having the "use utf8;" pragma
1104 or not. In the end, I fudged it by using the RunPerlTest script to insert
1105 "use utf8;" explicitly for the UTF-8 tests.
1106
1107 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1108 the end of the subject string, contrary to the documentation and to what
1109 Perl does. This was true of both matching functions. Now it matches only at
1110 the start of the subject and immediately after *internal* newlines.
1111
1112 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1113 a pointer to an int instead of a pointer to an unsigned long int. This
1114 caused problems on 64-bit systems.
1115
1116 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1117 instance of the 'standard' template library not being so standard".
1118
1119 10. There was no check on the number of named subpatterns nor the maximum
1120 length of a subpattern name. The product of these values is used to compute
1121 the size of the memory block for a compiled pattern. By supplying a very
1122 long subpattern name and a large number of named subpatterns, the size
1123 computation could be caused to overflow. This is now prevented by limiting
1124 the length of names to 32 characters, and the number of named subpatterns
1125 to 10,000.
1126
1127 11. Subpatterns that are repeated with specific counts have to be replicated in
1128 the compiled pattern. The size of memory for this was computed from the
1129 length of the subpattern and the repeat count. The latter is limited to
1130 65535, but there was no limit on the former, meaning that integer overflow
1131 could in principle occur. The compiled length of a repeated subpattern is
1132 now limited to 30,000 bytes in order to prevent this.
1133
1134 12. Added the optional facility to have named substrings with the same name.
1135
1136 13. Added the ability to use a named substring as a condition, using the
1137 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1138 are numbers (not recommended). Forward references are permitted.
1139
1140 14. Added forward references in named backreferences (if you see what I mean).
1141
1142 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1143 pattern could run off the end of the subject. For example, the pattern
1144 "(?s)(.{1,5})"8 did this with the subject "ab".
1145
1146 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1147 PCRE_CASELESS was set when matching characters that were quantified with ?
1148 or *.
1149
1150 17. A character class other than a single negated character that had a minimum
1151 but no maximum quantifier - for example [ab]{6,} - was not handled
1152 correctly by pce_dfa_exec(). It would match only one character.
1153
1154 18. A valid (though odd) pattern that looked like a POSIX character
1155 class but used an invalid character after [ (for example [[,abc,]]) caused
1156 pcre_compile() to give the error "Failed: internal error: code overflow" or
1157 in some cases to crash with a glibc free() error. This could even happen if
1158 the pattern terminated after [[ but there just happened to be a sequence of
1159 letters, a binary zero, and a closing ] in the memory that followed.
1160
1161 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1162 over the years. Originally (before any Unicode support), just the bottom 8
1163 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1164 output from "man perlunicode" includes this:
1165
1166 The regular expression compiler produces polymorphic opcodes. That
1167 is, the pattern adapts to the data and automatically switches to
1168 the Unicode character scheme when presented with Unicode data--or
1169 instead uses a traditional byte scheme when presented with byte
1170 data.
1171
1172 Sadly, a wide octal escape does not cause a switch, and in a string with
1173 no other multibyte characters, these octal escapes are treated as before.
1174 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1175 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1176 Unicode string.
1177
1178 I have not perpetrated such confusion in PCRE. Up till now, it took just
1179 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1180 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1181 translate to the appropriate multibyte character.
1182
1183 29. Applied some refactoring to reduce the number of warnings from Microsoft
1184 and Borland compilers. This has included removing the fudge introduced
1185 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1186 a warning about an unused variable.
1187
1188 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1189 characters since release 4.0, because Perl (from release 5.004) does not.
1190 [Or at least, is documented not to: some releases seem to be in conflict
1191 with the documentation.] However, when a pattern was studied with
1192 pcre_study() and all its branches started with \s, PCRE still included VT
1193 as a possible starting character. Of course, this did no harm; it just
1194 caused an unnecessary match attempt.
1195
1196 22. Removed a now-redundant internal flag bit that recorded the fact that case
1197 dependency changed within the pattern. This was once needed for "required
1198 byte" processing, but is no longer used. This recovers a now-scarce options
1199 bit. Also moved the least significant internal flag bit to the most-
1200 significant bit of the word, which was not previously used (hangover from
1201 the days when it was an int rather than a uint) to free up another bit for
1202 the future.
1203
1204 23. Added support for CRLF line endings as well as CR and LF. As well as the
1205 default being selectable at build time, it can now be changed at runtime
1206 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1207 specify that it is scanning data with non-default line endings.
1208
1209 24. Changed the definition of CXXLINK to make it agree with the definition of
1210 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1211
1212 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1213 recursions. This makes a big different to stack usage for some patterns.
1214
1215 26. If a subpattern containing a named recursion or subroutine reference such
1216 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1217 the space required for the compiled pattern went wrong and gave too small a
1218 value. Depending on the environment, this could lead to "Failed: internal
1219 error: code overflow at offset 49" or "glibc detected double free or
1220 corruption" errors.
1221
1222 27. Applied patches from Google (a) to support the new newline modes and (b) to
1223 advance over multibyte UTF-8 characters in GlobalReplace.
1224
1225 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1226 difference for some implementation of PCRE in some Windows version.
1227
1228 29. Added some extra testing facilities to pcretest:
1229
1230 \q<number> in a data line sets the "match limit" value
1231 \Q<number> in a data line sets the "match recursion limt" value
1232 -S <number> sets the stack size, where <number> is in megabytes
1233
1234 The -S option isn't available for Windows.
1235
1236
1237 Version 6.6 06-Feb-06
1238 ---------------------
1239
1240 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1241 in pcreposix.h. I have copied the definition from pcre.h.
1242
1243 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1244 because pcre.h is no longer a built file.
1245
1246 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1247 not normally included in the compiled code.
1248
1249
1250 Version 6.5 01-Feb-06
1251 ---------------------
1252
1253 1. When using the partial match feature with pcre_dfa_exec(), it was not
1254 anchoring the second and subsequent partial matches at the new starting
1255 point. This could lead to incorrect results. For example, with the pattern
1256 /1234/, partially matching against "123" and then "a4" gave a match.
1257
1258 2. Changes to pcregrep:
1259
1260 (a) All non-match returns from pcre_exec() were being treated as failures
1261 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1262 error message is output. Some extra information is given for the
1263 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1264 probably the only errors that are likely to be caused by users (by
1265 specifying a regex that has nested indefinite repeats, for instance).
1266 If there are more than 20 of these errors, pcregrep is abandoned.
1267
1268 (b) A binary zero was treated as data while matching, but terminated the
1269 output line if it was written out. This has been fixed: binary zeroes
1270 are now no different to any other data bytes.
1271
1272 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1273 used to set a locale for matching. The --locale=xxxx long option has
1274 been added (no short equivalent) to specify a locale explicitly on the
1275 pcregrep command, overriding the environment variables.
1276
1277 (d) When -B was used with -n, some line numbers in the output were one less
1278 than they should have been.
1279
1280 (e) Added the -o (--only-matching) option.
1281
1282 (f) If -A or -C was used with -c (count only), some lines of context were
1283 accidentally printed for the final match.
1284
1285 (g) Added the -H (--with-filename) option.
1286
1287 (h) The combination of options -rh failed to suppress file names for files
1288 that were found from directory arguments.
1289
1290 (i) Added the -D (--devices) and -d (--directories) options.
1291
1292 (j) Added the -F (--fixed-strings) option.
1293
1294 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1295
1296 (l) Added the --colo(u)r option.
1297
1298 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1299 is not present by default.
1300
1301 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1302 items such as (?R) or (?1), when the recursion could match a number of
1303 alternatives. If it matched one of the alternatives, but subsequently,
1304 outside the recursion, there was a failure, the code tried to back up into
1305 the recursion. However, because of the way PCRE is implemented, this is not
1306 possible, and the result was an incorrect result from the match.
1307
1308 In order to prevent this happening, the specification of recursion has
1309 been changed so that all such subpatterns are automatically treated as
1310 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1311
1312 4. I had overlooked the fact that, in some locales, there are characters for
1313 which isalpha() is true but neither isupper() nor islower() are true. In
1314 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1315 and ordfeminine) are like this. This affected the treatment of \w and \W
1316 when they appeared in character classes, but not when they appeared outside
1317 a character class. The bit map for "word" characters is now created
1318 separately from the results of isalnum() instead of just taking it from the
1319 upper, lower, and digit maps. (Plus the underscore character, of course.)
1320
1321 5. The above bug also affected the handling of POSIX character classes such as
1322 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1323 permanent tables. Instead, the bit maps for such a class were previously
1324 created as the appropriate unions of the upper, lower, and digit bitmaps.
1325 Now they are created by subtraction from the [[:word:]] class, which has
1326 its own bitmap.
1327
1328 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1329 It is created by subtracting the vertical space characters (\x09, \x0a,
1330 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1331 subtraction was done in the overall bitmap for a character class, meaning
1332 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1333 be recognized. This bug has been fixed.
1334
1335 7. Patches from the folks at Google:
1336
1337 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1338 real life, but is still worth protecting against".
1339
1340 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1341 regular expressions".
1342
1343 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1344 have it.
1345
1346 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1347 "configure" and the latter not, in order to fix a problem somebody had
1348 with compiling the Arg class on HP-UX.
1349
1350 (e) Improve the error-handling of the C++ wrapper a little bit.
1351
1352 (f) New tests for checking recursion limiting.
1353
1354 8. The pcre_memmove() function, which is used only if the environment does not
1355 have a standard memmove() function (and is therefore rarely compiled),
1356 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1357 returning a result (though PCRE never actually uses the result).
1358
1359 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1360 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1361 returned instead of calling malloc() with an overflowing number that would
1362 most likely cause subsequent chaos.
1363
1364 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1365
1366 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1367 with this option is matched, the nmatch and pmatch options of regexec() are
1368 ignored.
1369
1370 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1371 provided in case anyone wants to the the POSIX interface with UTF-8
1372 strings.
1373
1374 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1375 C++ linking (needed for some HP-UX environments).
1376
1377 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1378 (unused parameter) and in the pcre_printint() function (omitted "default"
1379 switch label when the default is to do nothing).
1380
1381 15. Added some code to make it possible, when PCRE is compiled as a C++
1382 library, to replace subject pointers for pcre_exec() with a smart pointer
1383 class, thus making it possible to process discontinuous strings.
1384
1385 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1386 much the same function. They were added by different people who were trying
1387 to make PCRE easy to compile on non-Unix systems. It has been suggested
1388 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1389 for compiling on Windows systems. I have therefore replaced it with
1390 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1391 defaults to "extern" for C or "extern C" for C++, which works fine on
1392 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1393 SCOPE with something explicit in config.h. In addition:
1394
1395 (a) pcreposix.h still had just "extern" instead of either of these macros;
1396 I have replaced it with PCRE_DATA_SCOPE.
1397
1398 (b) Functions such as _pcre_xclass(), which are internal to the library,
1399 but external in the C sense, all had PCRE_EXPORT in their definitions.
1400 This is apparently wrong for the Windows case, so I have removed it.
1401 (It makes no difference on Unix-like systems.)
1402
1403 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1404 of recursive calls to match(). This is different to MATCH_LIMIT because
1405 that limits the total number of calls to match(), not all of which increase
1406 the depth of recursion. Limiting the recursion depth limits the amount of
1407 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1408 when PCRE is compiled, and changed at run time. A patch from Google adds
1409 this functionality to the C++ interface.
1410
1411 18. Changes to the handling of Unicode character properties:
1412
1413 (a) Updated the table to Unicode 4.1.0.
1414
1415 (b) Recognize characters that are not in the table as "Cn" (undefined).
1416
1417 (c) I revised the way the table is implemented to a much improved format
1418 which includes recognition of ranges. It now supports the ranges that
1419 are defined in UnicodeData.txt, and it also amalgamates other
1420 characters into ranges. This has reduced the number of entries in the
1421 table from around 16,000 to around 3,000, thus reducing its size
1422 considerably. I realized I did not need to use a tree structure after
1423 all - a binary chop search is just as efficient. Having reduced the
1424 number of entries, I extended their size from 6 bytes to 8 bytes to
1425 allow for more data.
1426
1427 (d) Added support for Unicode script names via properties such as \p{Han}.
1428
1429 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1430 matching that character.
1431
1432 20. When matching a repeated Unicode property with a minimum greater than zero,
1433 (for example \pL{2,}), PCRE could look past the end of the subject if it
1434 reached it while seeking the minimum number of characters. This could
1435 happen only if some of the characters were more than one byte long, because
1436 there is a check for at least the minimum number of bytes.
1437
1438 21. Refactored the implementation of \p and \P so as to be more general, to
1439 allow for more different types of property in future. This has changed the
1440 compiled form incompatibly. Anybody with saved compiled patterns that use
1441 \p or \P will have to recompile them.
1442
1443 22. Added "Any" and "L&" to the supported property types.
1444
1445 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1446 but give a compile time error if the value is greater than 0xff.
1447
1448 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1449 accidentally not being installed or uninstalled.
1450
1451 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1452 made were to insert the current release number. This seemed silly, because
1453 it made things harder for people building PCRE on systems that don't run
1454 "configure". I have turned pcre.h into a distributed file, no longer built
1455 by "configure", with the version identification directly included. There is
1456 no longer a pcre.h.in file.
1457
1458 However, this change necessitated a change to the pcre-config script as
1459 well. It is built from pcre-config.in, and one of the substitutions was the
1460 release number. I have updated configure.ac so that ./configure now finds
1461 the release number by grepping pcre.h.
1462
1463 26. Added the ability to run the tests under valgrind.
1464
1465
1466 Version 6.4 05-Sep-05
1467 ---------------------
1468
1469 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1470 "--" to be printed when multiple files were scanned, even when none of the
1471 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1472 consider it to be a bug, and have restored the previous behaviour.
1473
1474 2. A couple of code tidies to get rid of compiler warnings.
1475
1476 3. The pcretest program used to cheat by referring to symbols in the library
1477 whose names begin with _pcre_. These are internal symbols that are not
1478 really supposed to be visible externally, and in some environments it is
1479 possible to suppress them. The cheating is now confined to including
1480 certain files from the library's source, which is a bit cleaner.
1481
1482 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1483 file's purpose clearer.
1484
1485 5. Reorganized pcre_ucp_findchar().
1486
1487
1488 Version 6.3 15-Aug-05
1489 ---------------------
1490
1491 1. The file libpcre.pc.in did not have general read permission in the tarball.
1492
1493 2. There were some problems when building without C++ support:
1494
1495 (a) If C++ support was not built, "make install" and "make test" still
1496 tried to test it.
1497
1498 (b) There were problems when the value of CXX was explicitly set. Some
1499 changes have been made to try to fix these, and ...
1500
1501 (c) --disable-cpp can now be used to explicitly disable C++ support.
1502
1503 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1504 backslash in a target when C++ was disabled. This confuses some
1505 versions of "make", apparently. Using an intermediate variable solves
1506 this. (Same for CPP_LOBJ.)
1507
1508 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1509 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1510 necessary on certain architectures.
1511
1512 4. Added a setting of -export-symbols-regex to the link command to remove
1513 those symbols that are exported in the C sense, but actually are local
1514 within the library, and not documented. Their names all begin with
1515 "_pcre_". This is not a perfect job, because (a) we have to except some
1516 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1517 available (and never for static libraries). I have made a note to try to
1518 find a way round (a) in the future.
1519
1520
1521 Version 6.2 01-Aug-05
1522 ---------------------
1523
1524 1. There was no test for integer overflow of quantifier values. A construction
1525 such as {1111111111111111} would give undefined results. What is worse, if
1526 a minimum quantifier for a parenthesized subpattern overflowed and became
1527 negative, the calculation of the memory size went wrong. This could have
1528 led to memory overwriting.
1529
1530 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1531
1532 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1533 operating environments where this matters.
1534
1535 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1536 PCRE options from within the C++ wrapper.
1537
1538 5. Named capturing subpatterns were not being correctly counted when a pattern
1539 was compiled. This caused two problems: (a) If there were more than 100
1540 such subpatterns, the calculation of the memory needed for the whole
1541 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1542 back references of the form \12, where the number was greater than 9, were
1543 not recognized as back references, even though there were sufficient
1544 previous subpatterns.
1545
1546 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1547 versions of gcc, e.g. 2.95.4.
1548
1549
1550 Version 6.1 21-Jun-05
1551 ---------------------
1552
1553 1. There was one reference to the variable "posix" in pcretest.c that was not
1554 surrounded by "#if !defined NOPOSIX".
1555
1556 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1557 the cross-check on the old pcre_info() function, for the benefit of the
1558 cut-down version of PCRE that is currently imported into Exim.
1559
1560 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1561 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1562 patterns that start (?i) but I don't think that matters. The use of (?i) is
1563 just an example; this all applies to the other options as well.
1564
1565 4. Since libtool seems to echo the compile commands it is issuing, the output
1566 from "make" can be reduced a bit by putting "@" in front of each libtool
1567 compile command.
1568
1569 5. Patch from the folks at Google for configure.in to be a bit more thorough
1570 in checking for a suitable C++ installation before trying to compile the
1571 C++ stuff. This should fix a reported problem when a compiler was present,
1572 but no suitable headers.
1573
1574 6. The man pages all had just "PCRE" as their title. I have changed them to
1575 be the relevant file name. I have also arranged that these names are
1576 retained in the file doc/pcre.txt, which is a concatenation in text format
1577 of all the man pages except the little individual ones for each function.
1578
1579 7. The NON-UNIX-USE file had not been updated for the different set of source
1580 files that come with release 6. I also added a few comments about the C++
1581 wrapper.
1582
1583
1584 Version 6.0 07-Jun-05
1585 ---------------------
1586
1587 1. Some minor internal re-organization to help with my DFA experiments.
1588
1589 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1590 didn't matter for the library itself when fully configured, but did matter
1591 when compiling without UCP support, or within Exim, where the ucp files are
1592 not imported.
1593
1594 3. Refactoring of the library code to split up the various functions into
1595 different source modules. The addition of the new DFA matching code (see
1596 below) to a single monolithic source would have made it really too
1597 unwieldy, quite apart from causing all the code to be include in a
1598 statically linked application, when only some functions are used. This is
1599 relevant even without the DFA addition now that patterns can be compiled in
1600 one application and matched in another.
1601
1602 The downside of splitting up is that there have to be some external
1603 functions and data tables that are used internally in different modules of
1604 the library but which are not part of the API. These have all had their
1605 names changed to start with "_pcre_" so that they are unlikely to clash
1606 with other external names.
1607
1608 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1609 a different (DFA) algorithm. Although it is slower than the original
1610 function, it does have some advantages for certain types of matching
1611 problem.
1612
1613 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1614 including restarting after a partial match.
1615
1616 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1617 defined when compiling for Windows was sent to me. I have put it into the
1618 code, though I have no means of testing or verifying it.
1619
1620 7. Added the pcre_refcount() auxiliary function.
1621
1622 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1623 match before or at the first newline in the subject string. In pcretest,
1624 the /f option on a pattern can be used to set this.
1625
1626 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1627 would behave wrongly. This has been present in PCRE since release 4.0.
1628
1629 10. A number of changes to the pcregrep command:
1630
1631 (a) Refactored how -x works; insert ^(...)$ instead of setting
1632 PCRE_ANCHORED and checking the length, in preparation for adding
1633 something similar for -w.
1634
1635 (b) Added the -w (match as a word) option.
1636
1637 (c) Refactored the way lines are read and buffered so as to have more
1638 than one at a time available.
1639
1640 (d) Implemented a pcregrep test script.
1641
1642 (e) Added the -M (multiline match) option. This allows patterns to match
1643 over several lines of the subject. The buffering ensures that at least
1644 8K, or the rest of the document (whichever is the shorter) is available
1645 for matching (and similarly the previous 8K for lookbehind assertions).
1646
1647 (f) Changed the --help output so that it now says
1648
1649 -w, --word-regex(p)
1650
1651 instead of two lines, one with "regex" and the other with "regexp"
1652 because that confused at least one person since the short forms are the
1653 same. (This required a bit of code, as the output is generated
1654 automatically from a table. It wasn't just a text change.)
1655
1656 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1657 option but starts with a hyphen. Could be a pattern or a path name
1658 starting with a hyphen, for instance.
1659
1660 (h) "-" can be given as a file name to represent stdin.
1661
1662 (i) When file names are being printed, "(standard input)" is used for
1663 the standard input, for compatibility with GNU grep. Previously
1664 "<stdin>" was used.
1665
1666 (j) The option --label=xxx can be used to supply a name to be used for
1667 stdin when file names are being printed. There is no short form.
1668
1669 (k) Re-factored the options decoding logic because we are going to add
1670 two more options that take data. Such options can now be given in four
1671 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1672
1673 (l) Added the -A, -B, and -C options for requesting that lines of context
1674 around matches be printed.
1675
1676 (m) Added the -L option to print the names of files that do not contain
1677 any matching lines, that is, the complement of -l.
1678
1679 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1680 continue to scan other files.
1681
1682 (o) The -s option was incorrectly implemented. For compatibility with other
1683 greps, it now suppresses the error message for a non-existent or non-
1684 accessible file (but not the return code). There is a new option called
1685 -q that suppresses the output of matching lines, which was what -s was
1686 previously doing.
1687
1688 (p) Added --include and --exclude options to specify files for inclusion
1689 and exclusion when recursing.
1690
1691 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1692 Hopefully, it now does.
1693
1694 12. Missing cast in pcre_study().
1695
1696 13. Added an "uninstall" target to the makefile.
1697
1698 14. Replaced "extern" in the function prototypes in Makefile.in with
1699 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1700 world, but is set differently for Windows.
1701
1702 15. Added a second compiling function called pcre_compile2(). The only
1703 difference is that it has an extra argument, which is a pointer to an
1704 integer error code. When there is a compile-time failure, this is set
1705 non-zero, in addition to the error test pointer being set to point to an
1706 error message. The new argument may be NULL if no error number is required
1707 (but then you may as well call pcre_compile(), which is now just a
1708 wrapper). This facility is provided because some applications need a
1709 numeric error indication, but it has also enabled me to tidy up the way
1710 compile-time errors are handled in the POSIX wrapper.
1711
1712 16. Added VPATH=.libs to the makefile; this should help when building with one
1713 prefix path and installing with another. (Or so I'm told by someone who
1714 knows more about this stuff than I do.)
1715
1716 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1717 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1718 match everything, including newlines. This is not POSIX-compatible, but
1719 somebody wanted the feature. From pcretest it can be activated by using
1720 both the P and the s flags.
1721
1722 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1723
1724 19. libpcre.pc was being incorrectly installed as executable.
1725
1726 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1727 it now also looks for '\r' so that it will work unmodified on Windows.
1728
1729 21. Added Google's contributed C++ wrapper to the distribution.
1730
1731 22. Added some untidy missing memory free() calls in pcretest, to keep
1732 Electric Fence happy when testing.
1733
1734
1735
1736 Version 5.0 13-Sep-04
1737 ---------------------
1738
1739 1. Internal change: literal characters are no longer packed up into items
1740 containing multiple characters in a single byte-string. Each character
1741 is now matched using a separate opcode. However, there may be more than one
1742 byte in the character in UTF-8 mode.
1743
1744 2. The pcre_callout_block structure has two new fields: pattern_position and
1745 next_item_length. These contain the offset in the pattern to the next match
1746 item, and its length, respectively.
1747
1748 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1749 insertion of callouts before each pattern item. Added the /C option to
1750 pcretest to make use of this.
1751
1752 4. On the advice of a Windows user, the lines
1753
1754 #if defined(_WIN32) || defined(WIN32)
1755 _setmode( _fileno( stdout ), 0x8000 );
1756 #endif /* defined(_WIN32) || defined(WIN32) */
1757
1758 have been added to the source of pcretest. This apparently does useful
1759 magic in relation to line terminators.
1760
1761 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1762 for the benefit of those environments where the "b" makes a difference.
1763
1764 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1765 to know about it. I have put a hack into configure.in that adds in code
1766 to set GCC=yes if CC=icc. This seems to end up at a point in the
1767 generated configure script that is early enough to affect the setting of
1768 compiler options, which is what is needed, but I have no means of testing
1769 whether it really works. (The user who reported this had patched the
1770 generated configure script, which of course I cannot do.)
1771
1772 LATER: After change 22 below (new libtool files), the configure script
1773 seems to know about icc (and also ecc). Therefore, I have commented out
1774 this hack in configure.in.
1775
1776 7. Added support for pkg-config (2 patches were sent in).
1777
1778 8. Negated POSIX character classes that used a combination of internal tables
1779 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1780 [[:^ascii]]. Typically, they would match almost any characters. The other
1781 POSIX classes were not broken in this way.
1782
1783 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1784 to find the match, as PCRE was deluded into thinking that the match had to
1785 start at the start point or following a newline. The same bug applied to
1786 patterns with negative forward assertions or any backward assertions
1787 preceding ".*" at the start, unless the pattern required a fixed first
1788 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1789
1790 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1791 starting at the last subject character, bytes beyond the end of the subject
1792 string were read.
1793
1794 11. Renamed the variable "class" as "classbits" to make life easier for C++
1795 users. (Previously there was a macro definition, but it apparently wasn't
1796 enough.)
1797
1798 12. Added the new field "tables" to the extra data so that tables can be passed
1799 in at exec time, or the internal tables can be re-selected. This allows
1800 a compiled regex to be saved and re-used at a later time by a different
1801 program that might have everything at different addresses.
1802
1803 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1804 -R library as well as a -L library.
1805
1806 14. The debugging options of pcretest (-d on the command line or D on a
1807 pattern) showed incorrect output for anything following an extended class
1808 that contained multibyte characters and which was followed by a quantifier.
1809
1810 15. Added optional support for general category Unicode character properties
1811 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1812 support. It adds about 90K to the size of the library. The meanings of the
1813 inbuilt class escapes such as \d and \s have NOT been changed.
1814
1815 16. Updated pcredemo.c to include calls to free() to release the memory for the
1816 compiled pattern.
1817
1818 17. The generated file chartables.c was being created in the source directory
1819 instead of in the building directory. This caused the build to fail if the
1820 source directory was different from the building directory, and was
1821 read-only.
1822
1823 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1824 file. No doubt somebody will tell me if they don't make sense... Also added
1825 Dan Mooney's comments about building on OpenVMS.
1826
1827 19. Added support for partial matching via the PCRE_PARTIAL option for
1828 pcre_exec() and the \P data escape in pcretest.
1829
1830 20. Extended pcretest with 3 new pattern features:
1831
1832 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1833 write the compiled pattern to the file whose name is "rest-of-line".
1834 This is a straight binary dump of the data, with the saved pointer to
1835 the character tables forced to be NULL. The study data, if any, is
1836 written too. After writing, pcretest reads a new pattern.
1837
1838 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1839 compiled pattern from the given file. There must not be any
1840 occurrences of "<" in the file name (pretty unlikely); if there are,
1841 pcretest will instead treat the initial "<" as a pattern delimiter.
1842 After reading in the pattern, pcretest goes on to read data lines as
1843 usual.
1844
1845 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1846 and 16-bit fields in a compiled pattern, to simulate a pattern that
1847 was compiled on a host of opposite endianness.
1848
1849 21. The pcre-exec() function can now cope with patterns that were compiled on
1850 hosts of opposite endianness, with this restriction:
1851
1852 As for any compiled expression that is saved and used later, the tables
1853 pointer field cannot be preserved; the extra_data field in the arguments
1854 to pcre_exec() should be used to pass in a tables address if a value
1855 other than the default internal tables were used at compile time.
1856
1857 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1858 now diagnosed as an error. Previously, most of the time, a negative number
1859 would have been treated as zero, but if in addition "ovector" was passed as
1860 NULL, a crash could occur.
1861
1862 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1863 new versions from the libtool 1.5 distribution (the last one is a copy of
1864 a file called libtool.m4). This seems to have fixed the need to patch
1865 "configure" to support Darwin 1.3 (which I used to do). However, I still
1866 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1867 workstation).
1868
1869 24. Changed the PCRE licence to be the more standard "BSD" licence.
1870
1871
1872 Version 4.5 01-Dec-03
1873 ---------------------
1874
1875 1. There has been some re-arrangement of the code for the match() function so
1876 that it can be compiled in a version that does not call itself recursively.
1877 Instead, it keeps those local variables that need separate instances for
1878 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1879 needs to "recurse". Keeping track of where control must go is done by means
1880 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1881 hide most of the details from the main code, and operates only if
1882 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1883 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1884 operating.
1885
1886 To make it easier for callers to provide specially tailored get/free
1887 functions for this usage, two new functions, pcre_stack_malloc, and
1888 pcre_stack_free, are used. They are always called in strict stacking order,
1889 and the size of block requested is always the same.
1890
1891 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1892 PCRE has been compiled to use the stack or the heap for recursion. The
1893 -C option of pcretest uses this to show which version is compiled.
1894
1895 A new data escape \S, is added to pcretest; it causes the amounts of store
1896 obtained and freed by both kinds of malloc/free at match time to be added
1897 to the output.
1898
1899 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1900 what's available on my current Linux desktop machine.
1901
1902 3. When matching a UTF-8 string, the test for a valid string at the start has
1903 been extended. If start_offset is not zero, PCRE now checks that it points
1904 to a byte that is the start of a UTF-8 character. If not, it returns
1905 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1906 this is necessary because there may be backward assertions in the pattern.
1907 When matching the same subject several times, it may save resources to use
1908 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1909
1910 4. The code for checking the validity of UTF-8 strings has been tightened so
1911 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1912 containing "overlong sequences".
1913
1914 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1915 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1916 should have been "&", but it just so happened that all the cases this let
1917 through by mistake were picked up later in the function.
1918
1919 6. I had used a variable called "isblank" - this is a C99 function, causing
1920 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1921
1922 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1923 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1924 so the version is shown; (c) stop "make test" echoing "./RunTest".
1925
1926 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1927
1928 9. The prototype for memmove() for systems that don't have it was using
1929 size_t, but the inclusion of the header that defines size_t was later. I've
1930 moved the #includes for the C headers earlier to avoid this.
1931
1932 10. Added some adjustments to the code to make it easier to compiler on certain
1933 special systems:
1934
1935 (a) Some "const" qualifiers were missing.
1936 (b) Added the macro EXPORT before all exported functions; by default this
1937 is defined to be empty.
1938 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1939 that it reads its output file name as an argument instead of writing
1940 to the standard output and assuming this can be redirected.
1941
1942 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1943 class containing characters with values greater than 255, PCRE compilation
1944 went into a loop.
1945
1946 12. A recursive reference to a subpattern that was within another subpattern
1947 that had a minimum quantifier of zero caused PCRE to crash. For example,
1948 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1949 recursion. If the recursively-called subpattern itself had a zero repeat,
1950 that was OK.
1951
1952 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1953 buffer into which it was copied (for escape processing) was still set at
1954 1024, so long lines caused crashes.
1955
1956 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1957 "internal error: code overflow...". This applied to any character class
1958 that was followed by a possessive quantifier.
1959
1960 15. Modified the Makefile to add libpcre.la as a prerequisite for
1961 libpcreposix.la because I was told this is needed for a parallel build to
1962 work.
1963
1964 16. If a pattern that contained .* following optional items at the start was
1965 studied, the wrong optimizing data was generated, leading to matching
1966 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1967 matching string must start with a or b or c. The correct conclusion for
1968 this pattern is that a match can start with any character.
1969
1970
1971 Version 4.4 13-Aug-03
1972 ---------------------
1973
1974 1. In UTF-8 mode, a character class containing characters with values between
1975 127 and 255 was not handled correctly if the compiled pattern was studied.
1976 In fixing this, I have also improved the studying algorithm for such
1977 classes (slightly).
1978
1979 2. Three internal functions had redundant arguments passed to them. Removal
1980 might give a very teeny performance improvement.
1981
1982 3. Documentation bug: the value of the capture_top field in a callout is *one
1983 more than* the number of the hightest numbered captured substring.
1984
1985 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1986 in incorrectly linking with a previously installed version. They now link
1987 explicitly with libpcre.la.
1988
1989 5. configure.in no longer needs to recognize Cygwin specially.
1990
1991 6. A problem in pcre.in for Windows platforms is fixed.
1992
1993 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1994 pcretest, it used to include the size of the study block as part of its
1995 output. Unfortunately, the structure contains a field that has a different
1996 size on different hardware architectures. This meant that the tests that
1997 showed this size failed. As the block is currently always of a fixed size,
1998 this information isn't actually particularly useful in pcretest output, so
1999 I have just removed it.
2000
2001 8. Three pre-processor statements accidentally did not start in column 1.
2002 Sadly, there are *still* compilers around that complain, even though
2003 standard C has not required this for well over a decade. Sigh.
2004
2005 9. In pcretest, the code for checking callouts passed small integers in the
2006 callout_data field, which is a void * field. However, some picky compilers
2007 complained about the casts involved for this on 64-bit systems. Now
2008 pcretest passes the address of the small integer instead, which should get
2009 rid of the warnings.
2010
2011 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2012 both compile and run time, and gives an error if an invalid UTF-8 sequence
2013 is found. There is a option for disabling this check in cases where the
2014 string is known to be correct and/or the maximum performance is wanted.
2015
2016 11. In response to a bug report, I changed one line in Makefile.in from
2017
2018 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2019 to
2020 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2021
2022 to look similar to other lines, but I have no way of telling whether this
2023 is the right thing to do, as I do not use Windows. No doubt I'll get told
2024 if it's wrong...
2025
2026
2027 Version 4.3 21-May-03
2028 ---------------------
2029
2030 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2031 Makefile.
2032
2033 2. Some refactoring to improve the quality of the code:
2034
2035 (i) The utf8_table... variables are now declared "const".
2036
2037 (ii) The code for \cx, which used the "case flipping" table to upper case
2038 lower case letters, now just substracts 32. This is ASCII-specific,
2039 but the whole concept of \cx is ASCII-specific, so it seems
2040 reasonable.
2041
2042 (iii) PCRE was using its character types table to recognize decimal and
2043 hexadecimal digits in the pattern. This is silly, because it handles
2044 only 0-9, a-f, and A-F, but the character types table is locale-
2045 specific, which means strange things might happen. A private
2046 table is now used for this - though it costs 256 bytes, a table is
2047 much faster than multiple explicit tests. Of course, the standard
2048 character types table is still used for matching digits in subject
2049 strings against \d.
2050
2051 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2052 ending in _t are). So I've renamed it as ESC_tee.
2053
2054 3. The first argument for regexec() in the POSIX wrapper should have been
2055 defined as "const".
2056
2057 4. Changed pcretest to use malloc() for its buffers so that they can be
2058 Electric Fenced for debugging.
2059
2060 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2061 to read one or more bytes before the start of the subject string. Often this
2062 had no effect on PCRE's behaviour, but in some circumstances it could
2063 provoke a segmentation fault.
2064
2065 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2066 to try to read one or more bytes before the start of the subject string.
2067
2068 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2069 UTF-8 support could misbehave in various ways if the subject string
2070 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2071 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2072 back over UTF-8 characters.)
2073
2074
2075 Version 4.2 14-Apr-03
2076 ---------------------
2077
2078 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2079
2080 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2081 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2082 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2083 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2084 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2085 and BUILD_EXEEXT
2086 Note: automatic setting of the BUILD variables is not yet working
2087 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2088 compile-time but not at link-time
2089 [LINK]: use for linking executables only
2090 make different versions for Windows and non-Windows
2091 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2092 libraries
2093 [LINK_FOR_BUILD]: new variable
2094 [OBJEXT]: use throughout
2095 [EXEEXT]: use throughout
2096 <winshared>: new target
2097 <wininstall>: new target
2098 <dftables.o>: use native compiler
2099 <dftables>: use native linker
2100 <install>: handle Windows platform correctly
2101 <clean>: ditto
2102 <check>: ditto
2103 copy DLL to top builddir before testing
2104
2105 As part of these changes, -no-undefined was removed again. This was reported
2106 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2107 in any case.
2108
2109 3. Some tidies to get rid of compiler warnings:
2110
2111 . In the match_data structure, match_limit was an unsigned long int, whereas
2112 match_call_count was an int. I've made them both unsigned long ints.
2113
2114 . In pcretest the fact that a const uschar * doesn't automatically cast to
2115 a void * provoked a warning.
2116
2117 . Turning on some more compiler warnings threw up some "shadow" variables
2118 and a few more missing casts.
2119
2120 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2121 option, a class that contained a single character with a value between 128
2122 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2123
2124 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2125 option, a class that contained several characters, but with at least one
2126 whose value was between 128 and 255 caused PCRE to crash.
2127
2128
2129 Version 4.1 12-Mar-03
2130 ---------------------
2131
2132 1. Compiling with gcc -pedantic found a couple of places where casts were
2133 needed, and a string in dftables.c that was longer than standard compilers are
2134 required to support.
2135
2136 2. Compiling with Sun's compiler found a few more places where the code could
2137 be tidied up in order to avoid warnings.
2138
2139 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2140 first of these names is deprecated in the latest Autoconf in favour of the name
2141 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2142 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2143 analogy I have changed it to CFLAGS_FOR_BUILD.
2144
2145 4. Added -no-undefined to the linking command in the Makefile, because this is
2146 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2147 linking step for the pcreposix library.
2148
2149 5. PCRE was failing to diagnose the case of two named groups with the same
2150 name.
2151
2152 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2153 literal character that is needed in the subject for a match, and scans along to
2154 ensure that it is present before embarking on the full matching process. This
2155 saves time in cases of nested unlimited repeats that are never going to match.
2156 Problem: the scan can take a lot of time if the subject is very long (e.g.
2157 megabytes), thus penalizing straightforward matches. It is now done only if the
2158 amount of subject to be scanned is less than 1000 bytes.
2159
2160 7. A lesser problem with the same optimization is that it was recording the
2161 first character of an anchored pattern as "needed", thus provoking a search
2162 right along the subject, even when the first match of the pattern was going to
2163 fail. The "needed" character is now not set for anchored patterns, unless it
2164 follows something in the pattern that is of non-fixed length. Thus, it still
2165 fulfils its original purpose of finding quick non-matches in cases of nested
2166 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2167
2168
2169 Version 4.0 17-Feb-03
2170 ---------------------
2171
2172 1. If a comment in an extended regex that started immediately after a meta-item
2173 extended to the end of string, PCRE compiled incorrect data. This could lead to
2174 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2175
2176 2. Moved to autoconf 2.53 and libtool 1.4.2.
2177
2178 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2179 the special perltest8 script is no longer needed - all the tests can be run
2180 from a single perltest script.
2181
2182 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2183 by \s. It has now been removed in PCRE. This means it isn't recognized as
2184 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2185 class [:space:] *does* include VT, thereby creating a mess.
2186
2187 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2188 space and tab.
2189
2190 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2191 its new features into the main test script, reducing the number of scripts.
2192
2193 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2194 were backward compatible, and made the (?i) apply to the whole pattern, as if
2195 /i were given. Now it behaves more logically, and applies the option setting
2196 only to what follows. PCRE has been changed to follow suit. However, if it
2197 finds options settings right at the start of the pattern, it extracts them into
2198 the global options, as before. Thus, they show up in the info data.
2199
2200 8. Added support for the \Q...\E escape sequence. Characters in between are
2201 treated as literals. This is slightly different from Perl in that $ and @ are
2202 also handled as literals inside the quotes. In Perl, they will cause variable
2203 interpolation. Note the following examples:
2204
2205 Pattern PCRE matches Perl matches
2206
2207 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2208 \Qabc\$xyz\E abc\$xyz abc\$xyz
2209 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2210
2211 For compatibility with Perl, \Q...\E sequences are recognized inside character
2212 classes as well as outside them.
2213
2214 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2215 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2216 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2217 signed/unsigned warnings.
2218
2219 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2220 option for pcretest, so I've replaced it by a simple function that does just
2221 that job.
2222
2223 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2224 "pcregrep -".
2225
2226 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2227 Java package. This provides some syntactic sugar for simple cases of what my
2228 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2229 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2230 item, you can use this simplified notation. Note that only makes sense with
2231 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2232 greediness, whatever the setting of the PCRE_UNGREEDY option.
2233
2234 13. A change of greediness default within a pattern was not taking effect at
2235 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2236 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2237 was abstracted outside.
2238
2239 14. PCRE now supports the \G assertion. It is true when the current matching
2240 position is at the start point of the match. This differs from \A when the
2241 starting offset is non-zero. Used with the /g option of pcretest (or similar
2242 code), it works in the same way as it does for Perl's /g option. If all
2243 alternatives of a regex begin with \G, the expression is anchored to the start
2244 match position, and the "anchored" flag is set in the compiled expression.
2245
2246 15. Some bugs concerning the handling of certain option changes within patterns
2247 have been fixed. These applied to options other than (?ims). For example,
2248 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2249 been the other way round. Some of this was related to change 7 above.
2250
2251 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2252 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2253 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2254 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2255
2256 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2257 mode. Unlike ".", it always matches newline, whatever the setting of
2258 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2259 assertions. Perl allows it, but it doesn't (in general) work because it can't
2260 calculate the length of the lookbehind. At least, that's the case for Perl
2261 5.8.0 - I've been told they are going to document that it doesn't work in
2262 future.
2263
2264 18. Added an error diagnosis for escapes that PCRE does not support: these are
2265 \L, \l, \N, \P, \p, \U, \u, and \X.
2266
2267 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2268 reading past the end of the pattern in cases such as /[abcd/.
2269
2270 20. PCRE was getting more memory than necessary for patterns with classes that
2271 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2272
2273 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2274 compiling PCRE for use with Virtual Pascal.
2275
2276 22. Small fix to the Makefile to make it work properly if the build is done
2277 outside the source tree.
2278
2279 23. Added a new extension: a condition to go with recursion. If a conditional
2280 subpattern starts with (?(R) the "true" branch is used if recursion has
2281 happened, whereas the "false" branch is used only at the top level.
2282
2283 24. When there was a very long string of literal characters (over 255 bytes
2284 without UTF support, over 250 bytes with UTF support), the computation of how
2285 much memory was required could be incorrect, leading to segfaults or other
2286 strange effects.
2287
2288 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2289 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2290 there was a subsequent back reference to those brackets. This meant that, for
2291 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2292 possible to check for precisely this case. All we can do is abandon the
2293 optimization if .* occurs inside capturing brackets when there are any back
2294 references whatsoever. (See below for a better fix that came later.)
2295
2296 26. The handling of the optimization for finding the first character of a
2297 non-anchored pattern, and for finding a character that is required later in the
2298 match were failing in some cases. This didn't break the matching; it just
2299 failed to optimize when it could. The way this is done has been re-implemented.
2300
2301 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2302
2303 28. Added a new feature that provides some of the functionality that Perl
2304 provides with (?{...}). The facility is termed a "callout". The way it is done
2305 in PCRE is for the caller to provide an optional function, by setting
2306 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2307 global variable. By default it is unset, which disables all calling out. To get
2308 the function called, the regex must include (?C) at appropriate points. This
2309 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2310 This provides a means of identifying different callout points. When PCRE
2311 reaches such a point in the regex, if pcre_callout has been set, the external
2312 function is called. It is provided with data in a structure called
2313 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2314 matching continues; if it returns a non-zero value, the match at the current
2315 point fails. However, backtracking will occur if possible. [This was changed
2316 later and other features added - see item 49 below.]
2317
2318 29. pcretest is upgraded to test the callout functionality. It provides a
2319 callout function that displays information. By default, it shows the start of
2320 the match and the current position in the text. There are some new data escapes
2321 to vary what happens:
2322
2323 \C+ in addition, show current contents of captured substrings
2324 \C- do not supply a callout function
2325 \C!n return 1 when callout number n is reached
2326 \C!n!m return 1 when callout number n is reached for the mth time
2327
2328 30. If pcregrep was called with the -l option and just a single file name, it
2329 output "<stdin>" if a match was found, instead of the file name.
2330
2331 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2332 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2333 pcre_exec(). This saves a malloc/free per call. The default value of
2334 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2335 when configuring.
2336
2337 32. The default maximum size of a compiled pattern is 64K. There have been a
2338 few cases of people hitting this limit. The code now uses macros to handle the
2339 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2340 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2341 configuring. Tests 2 and 5 work only with 2-byte links because they output
2342 debugging information about compiled patterns.
2343
2344 33. Internal code re-arrangements:
2345
2346 (a) Moved the debugging function for printing out a compiled regex into
2347 its own source file (printint.c) and used #include to pull it into
2348 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2349 separate copies.
2350
2351 (b) Defined the list of op-code names for debugging as a macro in
2352 internal.h so that it is next to the definition of the opcodes.
2353
2354 (c) Defined a table of op-code lengths for simpler skipping along compiled
2355 code. This is again a macro in internal.h so that it is next to the
2356 definition of the opcodes.
2357
2358 34. Added support for recursive calls to individual subpatterns, along the
2359 lines of Robin Houston's patch (but implemented somewhat differently).
2360
2361 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2362 allow it to read and process whole directories in Win32. This code was
2363 contributed by Lionel Fourquaux; it has not been tested by me.
2364
2365 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2366 used to name a group. Names consist of alphanumerics and underscores, and must
2367 be unique. Back references use the syntax (?P=name) and recursive calls use
2368 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2369 numbers. The function pcre_fullinfo() can be used after compilation to extract
2370 a name/number map. There are three relevant calls:
2371
2372 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2373 PCRE_INFO_NAMECOUNT yields the number of entries
2374 PCRE_INFO_NAMETABLE yields a pointer to the map.
2375
2376 The map is a vector of fixed-size entries. The size of each entry depends on
2377 the length of the longest name used. The first two bytes of each entry are the
2378 group number, most significant byte first. There follows the corresponding
2379 name, zero terminated. The names are in alphabetical order.
2380
2381 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2382 case instead of 255. Making it the same both with and without UTF-8 support
2383 means that the same test output works with both.
2384
2385 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2386 calling malloc() with a zero argument.
2387
2388 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2389 optimization. I've improved things by keeping a bitmap of backreferences with
2390 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2391 fact referenced, the optimization can be applied. It is unlikely that a
2392 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2393 the match to follow \n) will appear inside brackets with a number greater than
2394 31, but if it does, any back reference > 31 suppresses the optimization.
2395
2396 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2397 of disabling numbered capturing parentheses. Any opening parenthesis that is
2398 not followed by ? behaves as if it were followed by ?: but named parentheses
2399 can still be used for capturing (and they will acquire numbers in the usual
2400 way).
2401
2402 41. Redesigned the return codes from the match() function into yes/no/error so
2403 that errors can be passed back from deep inside the nested calls. A malloc
2404 failure while inside a recursive subpattern call now causes the
2405 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2406
2407 42. It is now possible to set a limit on the number of times the match()
2408 function is called in a call to pcre_exec(). This facility makes it possible to
2409 limit the amount of recursion and backtracking, though not in a directly
2410 obvious way, because the match() function is used in a number of different
2411 circumstances. The count starts from zero for each position in the subject
2412 string (for non-anchored patterns). The default limit is, for compatibility, a
2413 large number, namely 10 000 000. You can change this in two ways:
2414
2415 (a) When configuring PCRE before making, you can use --with-match-limit=n
2416 to set a default value for the compiled library.
2417
2418 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2419 a different value is set. See 45 below.
2420
2421 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2422
2423 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2424 of things that can be changed at compile time. The first argument specifies
2425 what is wanted and the second points to where the information is to be placed.
2426 The current list of available information is:
2427
2428 PCRE_CONFIG_UTF8
2429
2430 The output is an integer that is set to one if UTF-8 support is available;
2431 otherwise it is set to zero.
2432
2433 PCRE_CONFIG_NEWLINE
2434
2435 The output is an integer that it set to the value of the code that is used for
2436 newline. It is either LF (10) or CR (13).
2437
2438 PCRE_CONFIG_LINK_SIZE
2439
2440 The output is an integer that contains the number of bytes used for internal
2441 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2442
2443 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2444
2445 The output is an integer that contains the threshold above which the POSIX
2446 interface uses malloc() for output vectors. See item 31 above.
2447
2448 PCRE_CONFIG_MATCH_LIMIT
2449
2450 The output is an unsigned integer that contains the default limit of the number
2451 of match() calls in a pcre_exec() execution. See 42 above.
2452
2453 44. pcretest has been upgraded by the addition of the -C option. This causes it
2454 to extract all the available output from the new pcre_config() function, and to
2455 output it. The program then exits immediately.
2456
2457 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2458 order to support additional features. One way would have been to define
2459 pcre_exec2() (for example) with extra arguments, but this would not have been
2460 extensible, and would also have required all calls to the original function to
2461 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2462 is used for passing in "extra" data from pcre_study().
2463
2464 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2465 contains the following fields:
2466
2467 flags a bitmap indicating which of the following fields are set
2468 study_data opaque data from pcre_study()
2469 match_limit a way of specifying a limit on match() calls for a specific
2470 call to pcre_exec()
2471 callout_data data for callouts (see 49 below)
2472
2473 The flag bits are also defined in pcre.h, and are
2474
2475 PCRE_EXTRA_STUDY_DATA
2476 PCRE_EXTRA_MATCH_LIMIT
2477 PCRE_EXTRA_CALLOUT_DATA
2478
2479 The pcre_study() function now returns one of these new pcre_extra blocks, with
2480 the actual study data pointed to by the study_data field, and the
2481 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2482 before. That is, this change is entirely upwards-compatible and requires no
2483 change to existing code.
2484
2485 If you want to pass in additional data to pcre_exec(), you can either place it
2486 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2487 block.
2488
2489 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2490 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2491 times with different match limits, until it finds the minimum value needed for
2492 pcre_exec() to complete. The value is then output. This can be instructive; for
2493 most simple matches the number is quite small, but for pathological cases it
2494 gets very large very quickly.
2495
2496 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2497 returns the size of the data block pointed to by the study_data field in a
2498 pcre_extra block, that is, the value that was passed as the argument to
2499 pcre_malloc() when PCRE was getting memory in which to place the information
2500 created by pcre_study(). The fourth argument should point to a size_t variable.
2501 pcretest has been extended so that this information is shown after a successful
2502 pcre_study() call when information about the compiled regex is being displayed.
2503
2504 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2505 because what follows is always an absolute path. (Later: it turns out that this
2506 is more than cosmetic for MinGW, because it doesn't like empty path
2507 components.)
2508
2509 49. Some changes have been made to the callout feature (see 28 above):
2510
2511 (i) A callout function now has three choices for what it returns:
2512
2513 0 => success, carry on matching
2514 > 0 => failure at this point, but backtrack if possible
2515 < 0 => serious error, return this value from pcre_exec()
2516
2517 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2518 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2519 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2520 use by callout functions. It will never be used by PCRE itself.
2521
2522 (ii) The pcre_extra structure (see 45 above) has a void * field called
2523 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2524 pcre_callout_block structure has a field of the same name. The contents of
2525 the field passed in the pcre_extra structure are passed to the callout
2526 function in the corresponding field in the callout block. This makes it
2527 easier to use the same callout-containing regex from multiple threads. For
2528 testing, the pcretest program has a new data escape
2529
2530 \C*n pass the number n (may be negative) as callout_data
2531
2532 If the callout function in pcretest receives a non-zero value as
2533 callout_data, it returns that value.
2534
2535 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2536 there were some redundant $(CFLAGS) in commands that are now specified as
2537 $(LINK), which already includes $(CFLAGS).
2538
2539 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2540 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2541 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2542 one-byte characters throughout. Note that case-insensitive matching applies
2543 only to characters whose values are less than 256. PCRE doesn't support the
2544 notion of cases for higher-valued characters.
2545
2546 (i) A character class whose characters are all within 0-255 is handled as
2547 a bit map, and the map is inverted for negative classes. Previously, a
2548 character > 255 always failed to match such a class; however it should
2549 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2550
2551 (ii) A negated character class with a single character < 255 is coded as
2552 "not this character" (OP_NOT). This wasn't working properly when the test
2553 character was multibyte, either singly or repeated.
2554
2555 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2556 mode, for example: \x{100}{2,3}.
2557
2558 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2559 singly or repeated) now correctly test multibyte characters. However,
2560 PCRE doesn't recognize any characters with values greater than 255 as
2561 digits, spaces, or word characters. Such characters always match \D, \S,
2562 and \W, and never match \d, \s, or \w.
2563
2564 (v) Classes may now contain characters and character ranges with values
2565 greater than 255. For example: [ab\x{100}-\x{400}].
2566
2567 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2568 PCRE in UTF-8 mode.
2569
2570 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2571 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2572 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2573 value.)
2574
2575 53. The single man page has become too large. I have therefore split it up into
2576 a number of separate man pages. These also give rise to individual HTML pages;
2577 these are now put in a separate directory, and there is an index.html page that
2578 lists them all. Some hyperlinking between the pages has been installed.
2579
2580 54. Added convenience functions for handling named capturing parentheses.
2581
2582 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2583 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2584 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2585 are faulted.
2586
2587 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2588 calling configure. These values are used when compiling the dftables.c program
2589 which is run to generate the source of the default character tables. They
2590 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2591 you will need to set these values.
2592
2593 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2594
2595
2596 Version 3.9 02-Jan-02
2597 ---------------------
2598
2599 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2600
2601 2. If --disable-static was given, the building process failed when trying to
2602 build pcretest and pcregrep. (For some reason it was using libtool to compile
2603 them, which is not right, as they aren't part of the library.)
2604
2605
2606 Version 3.8 18-Dec-01
2607 ---------------------
2608
2609 1. The experimental UTF-8 code was completely screwed up. It was packing the
2610 bytes in the wrong order. How dumb can you get?
2611
2612
2613 Version 3.7 29-Oct-01
2614 ---------------------
2615
2616 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2617 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2618 this didn't happen under Solaris 8, where I normally test things.
2619
2620 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2621 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2622 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2623 this fix an hour or so after the initial 3.7 release.)
2624
2625
2626 Version 3.6 23-Oct-01
2627 ---------------------
2628
2629 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2630 offsets passed as NULL with zero offset count.
2631
2632 2. The config.guess and config.sub files had not been updated when I moved to
2633 the latest autoconf.
2634
2635
2636 Version 3.5 15-Aug-01
2637 ---------------------
2638
2639 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2640 had been forgotten.
2641
2642 2. By using declared but undefined structures, we can avoid using "void"
2643 definitions in pcre.h while keeping the internal definitions of the structures
2644 private.
2645
2646 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2647 user point of view, this means that both static and shared libraries are built
2648 by default, but this can be individually controlled. More of the work of
2649 handling this static/shared cases is now inside libtool instead of PCRE's make
2650 file.
2651
2652 4. The pcretest utility is now installed along with pcregrep because it is
2653 useful for users (to test regexs) and by doing this, it automatically gets
2654 relinked by libtool. The documentation has been turned into a man page, so
2655 there are now .1, .txt, and .html versions in /doc.
2656
2657 5. Upgrades to pcregrep:
2658 (i) Added long-form option names like gnu grep.
2659 (ii) Added --help to list all options with an explanatory phrase.
2660 (iii) Added -r, --recursive to recurse into sub-directories.
2661 (iv) Added -f, --file to read patterns from a file.
2662
2663 6. pcre_exec() was referring to its "code" argument before testing that
2664 argument for NULL (and giving an error if it was NULL).
2665
2666 7. Upgraded Makefile.in to allow for compiling in a different directory from
2667 the source directory.
2668
2669 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2670 options bits, the pointer it was passed was to an int instead of to an unsigned
2671 long int. This mattered only on 64-bit systems.
2672
2673 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2674 generated) instead of pcre.in, which it its source. Also made the same change
2675 in several of the .c files.
2676
2677 10. A new release of gcc defines printf() as a macro, which broke pcretest
2678 because it had an ifdef in the middle of a string argument for printf(). Fixed
2679 by using separate calls to printf().
2680
2681 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2682 script, to force use of CR or LF instead of \n in the source. On non-Unix
2683 systems, the value can be set in config.h.
2684
2685 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2686 absolute limit. Changed the text of the error message to make this clear, and
2687 likewise updated the man page.
2688
2689 13. The limit of 99 on the number of capturing subpatterns has been removed.
2690 The new limit is 65535, which I hope will not be a "real" limit.
2691
2692
2693 Version 3.4 22-Aug-00
2694 ---------------------
2695
2696 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2697
2698 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2699
2700
2701 Version 3.3 01-Aug-00
2702 ---------------------
2703
2704 1. If an octal character was given, but the value was greater than \377, it
2705 was not getting masked to the least significant bits, as documented. This could
2706 lead to crashes in some systems.
2707
2708 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2709 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2710
2711 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2712 These just pass their arguments on to (pcre_free)(), but they are provided
2713 because some uses of PCRE bind it to non-C systems that can call its functions,
2714 but cannot call free() or pcre_free() directly.
2715
2716 4. Add "make test" as a synonym for "make check". Corrected some comments in
2717 the Makefile.
2718
2719 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2720 Makefile.
2721
2722 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2723 command called pgrep for grepping around the active processes.
2724
2725 7. Added the beginnings of support for UTF-8 character strings.
2726
2727 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2728 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2729 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2730 out for the ar command.)
2731
2732
2733 Version 3.2 12-May-00
2734 ---------------------
2735
2736 This is purely a bug fixing release.
2737
2738 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2739 of ZA. This was just one example of several cases that could provoke this bug,
2740 which was introduced by change 9 of version 2.00. The code for breaking
2741 infinite loops after an iteration that matches an empty string was't working
2742 correctly.
2743
2744 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2745 when matched against abbab (for example). After matching an empty string, it
2746 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2747 caused it to match further down the string than it should.
2748
2749 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2750 was there because it doesn't seem to be needed, and it causes trouble on some
2751 systems, as it is not a Standard C header. It has been removed.
2752
2753 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2754 were reported on the Macintosh. The changes were from
2755
2756 while ((c = *(++ptr)) != 0 && c != '\n');
2757 to
2758 while ((c = *(++ptr)) != 0 && c != '\n') ;
2759
2760 Totally extraordinary, but if that's what it takes...
2761
2762 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2763 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2764 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2765 assumes the way PCRE uses memmove() (always moving upwards).
2766
2767 6. PCRE is being used in one environment where strchr() is not available. There
2768 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2769 faster code anyway.
2770
2771
2772 Version 3.1 09-Feb-00
2773 ---------------------
2774
2775 The only change in this release is the fixing of some bugs in Makefile.in for
2776 the "install" target:
2777
2778 (1) It was failing to install pcreposix.h.
2779
2780 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2781
2782
2783 Version 3.0 01-Feb-00
2784 ---------------------
2785
2786 1. Add support for the /+ modifier to perltest (to output $` like it does in
2787 pcretest).
2788
2789 2. Add support for the /g modifier to perltest.
2790
2791 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2792 matches null strings.
2793
2794 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2795 pattern. Perl treats empty patterns specially - it reuses the most recent
2796 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2797 effect.
2798
2799 5. The POSIX interface was broken in that it was just handing over the POSIX
2800 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2801 required a bigger vector, with some working space on the end. This means that
2802 the POSIX wrapper now has to get and free some memory, and copy the results.
2803
2804 6. Added some simple autoconf support, placing the test data and the
2805 documentation in separate directories, re-organizing some of the
2806 information files, and making it build pcre-config (a GNU standard). Also added
2807 libtool support for building PCRE as a shared library, which is now the
2808 default.
2809
2810 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2811 09 are not valid octal constants. Single digits will be used for minor values
2812 less than 10.
2813
2814 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2815 existing programs that set these in the POSIX interface can use PCRE without
2816 modification.
2817
2818 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2819 return all that pcre_info() returns, plus additional data. The pcre_info()
2820 function is retained for compatibility, but is considered to be obsolete.
2821
2822 10. Added experimental recursion feature (?R) to handle one common case that
2823 Perl 5.6 will be able to do with (?p{...}).
2824
2825 11. Added support for POSIX character classes like [:alpha:], which Perl is
2826 adopting.
2827
2828
2829 Version 2.08 31-Aug-99
2830 ----------------------
2831
2832 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2833 trying to match at the startoffset position, but instead was moving forward to
2834 the next newline as if a previous match had failed.
2835
2836 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2837 and could get into a loop if a null string was matched other than at the start
2838 of the subject.
2839
2840 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2841 be distinguished at compile time, and for completeness also added PCRE_DATE.
2842
2843 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2844 in GnuWin32 environments.
2845
2846
2847 Version 2.07 29-Jul-99
2848 ----------------------
2849
2850 1. The documentation is now supplied in plain text form and HTML as well as in
2851 the form of man page sources.
2852
2853 2. C++ compilers don't like assigning (void *) values to other pointer types.
2854 In particular this affects malloc(). Although there is no problem in Standard
2855 C, I've put in casts to keep C++ compilers happy.
2856
2857 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2858 should be (const char *).
2859
2860 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2861 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2862 However, I haven't made this a standard facility. The documentation doesn't
2863 mention it, and the Makefile doesn't support it.
2864
2865 5. The Makefile now contains an "install" target, with editable destinations at
2866 the top of the file. The pcretest program is not installed.
2867
2868 6. pgrep -V now gives the PCRE version number and date.
2869
2870 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2871 causing the entire string to be ignored, instead of just the last character.
2872
2873 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2874 non-matching string, it can take a very, very long time, even for strings of
2875 quite modest length, because of the nested recursion. PCRE now does better in
2876 some of these cases. It does this by remembering the last required literal
2877 character in the pattern, and pre-searching the subject to ensure it is present
2878 before running the real match. In other words, it applies a heuristic to detect
2879 some types of certain failure quickly, and in the above example, if presented
2880 with a string that has no trailing " it gives "no match" very quickly.
2881
2882 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2883 other alternatives are tried instead.
2884
2885
2886 Version 2.06 09-Jun-99
2887 ----------------------
2888
2889 1. Change pcretest's output for amount of store used to show just the code
2890 space, because the remainder (the data block) varies in size between 32-bit and
2891 64-bit systems.
2892
2893 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2894 start matching at. This allows lookbehinds to work when searching for multiple
2895 occurrences in a string.
2896
2897 3. Added additional options to pcretest for testing multiple occurrences:
2898
2899 /+ outputs the rest of the string that follows a match
2900 /g loops for multiple occurrences, using the new startoffset argument
2901 /G loops for multiple occurrences by passing an incremented pointer
2902
2903 4. PCRE wasn't doing the "first character" optimization for patterns starting
2904 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2905 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2906 the letter 'x'. On long subject strings, this gives a significant speed-up.
2907
2908
2909 Version 2.05 21-Apr-99
2910 ----------------------
2911
2912 1. Changed the type of magic_number from int to long int so that it works
2913 properly on 16-bit systems.
2914
2915 2. Fixed a bug which caused patterns starting with .* not to work correctly
2916 when the subject string contained newline characters. PCRE was assuming
2917 anchoring for such patterns in all cases, which is not correct because .* will
2918 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2919 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2920 must be retried after every newline in the subject.
2921
2922
2923 Version 2.04 18-Feb-99
2924 ----------------------
2925
2926 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2927 computation of the store needed to hold the pattern was incorrect (too large).
2928 If such patterns were nested a few deep, this could multiply and become a real
2929 problem.
2930
2931 2. Added /M option to pcretest to show the memory requirement of a specific
2932 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2933
2934 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2935 compiled in such a way that the backtracking after subsequent failure was
2936 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2937 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2938
2939
2940 Version 2.03 02-Feb-99
2941 ----------------------
2942
2943 1. Fixed typo and small mistake in man page.
2944
2945 2. Added 4th condition (GPL supersedes if conflict) and created separate
2946 LICENCE file containing the conditions.
2947
2948 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2949 Perl, that is the internal \ allows the delimiter to be included in the
2950 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2951 the final delimiter, add \ to the end of the pattern (to test the error).
2952
2953 4. Added the convenience functions for extracting substrings after a successful
2954 match. Updated pcretest to make it able to test these functions.
2955
2956
2957 Version 2.02 14-Jan-99
2958 ----------------------
2959
2960 1. Initialized the working variables associated with each extraction so that
2961 their saving and restoring doesn't refer to uninitialized store.
2962
2963 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2964 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2965 fix the problem.
2966
2967 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2968 calls, and wasn't printing the correct value for compiling calls. Increased the
2969 default value of LOOPREPEAT, and the number of significant figures in the
2970 times.
2971
2972 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2973
2974 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2975 a building problem on Windows NT with a FAT file system.
2976
2977
2978 Version 2.01 21-Oct-98
2979 ----------------------
2980
2981 1. Changed the API for pcre_compile() to allow for the provision of a pointer
2982 to character tables built by pcre_maketables() in the current locale. If NULL
2983 is passed, the default tables are used.
2984
2985
2986 Version 2.00 24-Sep-98
2987 ----------------------
2988
2989 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2990 it any more.
2991
2992 2. Allow quantification of (?>) groups, and make it work correctly.
2993
2994 3. The first character computation wasn't working for (?>) groups.
2995
2996 4. Correct the implementation of \Z (it is permitted to match on the \n at the
2997 end of the subject) and add 5.005's \z, which really does match only at the
2998 very end of the subject.
2999
3000 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3001
3002 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3003 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3004 localized options. All options to pcre_study() were also removed.
3005
3006 7. Add other new features from 5.005:
3007
3008 $(?<= positive lookbehind
3009 $(?<! negative lookbehind
3010 (?imsx-imsx) added the unsetting capability
3011 such a setting is global if at outer level; local otherwise
3012 (?imsx-imsx:) non-capturing groups with option setting
3013 (?(cond)re|re) conditional pattern matching
3014
3015 A backreference to itself in a repeated group matches the previous
3016 captured string.
3017
3018 8. General tidying up of studying (both automatic and via "study")
3019 consequential on the addition of new assertions.
3020
3021 9. As in 5.005, unlimited repeated groups that could match an empty substring
3022 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3023 runtime if any iteration does actually match an empty substring.
3024
3025 10. Include the RunTest script in the distribution.
3026
3027 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3028 discrepancies, some of which were old and were also with respect to 5.004. They
3029 have now been fixed.
3030
3031
3032 Version 1.09 28-Apr-98
3033 ----------------------
3034
3035 1. A negated single character class followed by a quantifier with a minimum
3036 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3037 program crashes, or just wrong answers. This did not apply to negated classes
3038 containing more than one character, or to minima other than one.
3039
3040
3041 Version 1.08 27-Mar-98
3042 ----------------------
3043
3044 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3045
3046 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3047 latter must appear before anything that relies on it in the pattern.
3048
3049
3050 Version 1.07 16-Feb-98
3051 ----------------------
3052
3053 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3054 repeat of a potentially empty string).
3055
3056
3057 Version 1.06 23-Jan-98
3058 ----------------------
3059
3060 1. Added Markus Oberhumer's little patches for C++.
3061
3062 2. Literal strings longer than 255 characters were broken.
3063
3064
3065 Version 1.05 23-Dec-97
3066 ----------------------
3067
3068 1. Negated character classes containing more than one character were failing if
3069 PCRE_CASELESS was set at run time.
3070
3071
3072 Version 1.04 19-Dec-97
3073 ----------------------
3074
3075 1. Corrected the man page, where some "const" qualifiers had been omitted.
3076
3077 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3078 input syntax.
3079
3080 3. Fixed memory leak which occurred when a regex with back references was
3081 matched with an offsets vector that wasn't big enough. The temporary memory
3082 that is used in this case wasn't being freed if the match failed.
3083
3084 4. Tidied pcretest to ensure it frees memory that it gets.
3085
3086 5. Temporary memory was being obtained in the case where the passed offsets
3087 vector was exactly big enough.
3088
3089 6. Corrected definition of offsetof() from change 5 below.
3090
3091 7. I had screwed up change 6 below and broken the rules for the use of
3092 setjmp(). Now fixed.
3093
3094
3095 Version 1.03 18-Dec-97
3096 ----------------------
3097
3098 1. A erroneous regex with a missing opening parenthesis was correctly
3099 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3100 on some systems.
3101
3102 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3103 it was reported that one broken compiler failed on the former because "code" is
3104 also an independent variable.
3105
3106 3. The erroneous regex a[]b caused an array overrun reference.
3107
3108 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3109 fail on data ending with that character. (It was going on too far, and checking
3110 the next character, typically a binary zero.) This was specific to the
3111 optimized code for single-character negative classes.
3112
3113 5. Added a contributed patch from the TIN world which does the following:
3114
3115 + Add an undef for memmove, in case the the system defines a macro for it.
3116
3117 + Add a definition of offsetof(), in case there isn't one. (I don't know
3118 the reason behind this - offsetof() is part of the ANSI standard - but
3119 it does no harm).
3120
3121 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3122 most of the places where whitespace preceded '#'. I have given up and
3123 allowed the remaining 2 cases to be at the margin.
3124
3125 + Rename some variables in pcre to eliminate shadowing. This seems very
3126 pedantic, but does no harm, of course.
3127
3128 6. Moved the call to setjmp() into its own function, to get rid of warnings
3129 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3130
3131 7. Constructs such as \d{8,} were compiling into the equivalent of
3132 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3133 outcome, but in this particular case used more store than had been allocated,
3134 which caused the bug to be discovered because it threw up an internal error.
3135
3136 8. The debugging code in both pcre and pcretest for outputting the compiled
3137 form of a regex was going wrong in the case of back references followed by
3138 curly-bracketed repeats.
3139
3140
3141 Version 1.02 12-Dec-97
3142 ----------------------
3143
3144 1. Typos in pcre.3 and comments in the source fixed.
3145
3146 2. Applied a contributed patch to get rid of places where it used to remove
3147 'const' from variables, and fixed some signed/unsigned and uninitialized
3148 variable warnings.
3149
3150 3. Added the "runtest" target to Makefile.
3151
3152 4. Set default compiler flag to -O2 rather than just -O.
3153
3154
3155 Version 1.01 19-Nov-97
3156 ----------------------
3157
3158 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3159 like /([ab]*)*/, that is, for classes with more than one character in them.
3160
3161 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3162 as /((?>a*))*/ (a PCRE_EXTRA facility).
3163
3164
3165 Version 1.00 18-Nov-97
3166 ----------------------
3167
3168 1. Added compile-time macros to support systems such as SunOS4 which don't have
3169 memmove() or strerror() but have other things that can be used instead.
3170
3171 2. Arranged that "make clean" removes the executables.
3172
3173
3174 Version 0.99 27-Oct-97
3175 ----------------------
3176
3177 1. Fixed bug in code for optimizing classes with only one character. It was
3178 initializing a 32-byte map regardless, which could cause it to run off the end
3179 of the memory it had got.
3180
3181 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3182
3183
3184 Version 0.98 22-Oct-97
3185 ----------------------
3186
3187 1. Fixed bug in code for handling temporary memory usage when there are more
3188 back references than supplied space in the ovector. This could cause segfaults.
3189
3190
3191 Version 0.97 21-Oct-97
3192 ----------------------
3193
3194 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3195
3196 2. Optimized negated single characters not to use a bit map.
3197
3198 3. Brought error texts together as macro definitions; clarified some of them;
3199 fixed one that was wrong - it said "range out of order" when it meant "invalid
3200 escape sequence".
3201
3202 4. Changed some char * arguments to const char *.
3203
3204 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3205
3206 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3207 pcretest.
3208
3209
3210 Version 0.96 16-Oct-97
3211 ----------------------
3212
3213 1. Added a simple "pgrep" utility to the distribution.
3214
3215 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3216 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3217 where "ddd" means "one or more decimal digits".
3218
3219 3. Fixed serious bug. If a pattern had a back reference, but the call to
3220 pcre_exec() didn't supply a large enough ovector to record the related
3221 identifying subpattern, the match always failed. PCRE now remembers the number
3222 of the largest back reference, and gets some temporary memory in which to save
3223 the offsets during matching if necessary, in order to ensure that
3224 backreferences always work.
3225
3226 4. Increased the compatibility with Perl in a number of ways:
3227
3228 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3229 to request this handling. The option can be set at compile or exec time.
3230
3231 (b) $ matches before a terminating newline by default; an option
3232 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3233 mode). The option can be set at compile or exec time.
3234
3235 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3236 the same as Perl's. If the decimal number it represents is less than 10
3237 or there aren't that many previous left capturing parentheses, an octal
3238 escape is read. Inside a character class, it's always an octal escape,
3239 even if it is a single digit.
3240
3241 (d) An escaped but undefined alphabetic character is taken as a literal,
3242 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3243 escapes.
3244
3245 (e) {0} is now permitted. (The previous item is removed from the compiled
3246 pattern).
3247
3248 5. Changed all the names of code files so that the basic parts are no longer
3249 than 10 characters, and abolished the teeny "globals.c" file.
3250
3251 6. Changed the handling of character classes; they are now done with a 32-byte
3252 bit map always.
3253
3254 7. Added the -d and /D options to pcretest to make it possible to look at the
3255 internals of compilation without having to recompile pcre.
3256
3257
3258 Version 0.95 23-Sep-97
3259 ----------------------
3260
3261 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3262 \x20 at the start of a run of normal characters. These were being treated as
3263 real characters, instead of the source characters being re-checked.
3264
3265
3266 Version 0.94 18-Sep-97
3267 ----------------------
3268
3269 1. The functions are now thread-safe, with the caveat that the global variables
3270 containing pointers to malloc() and free() or alternative functions are the
3271 same for all threads.
3272
3273 2. Get pcre_study() to generate a bitmap of initial characters for non-
3274 anchored patterns when this is possible, and use it if passed to pcre_exec().
3275
3276
3277 Version 0.93 15-Sep-97
3278 ----------------------
3279
3280 1. /(b)|(:+)/ was computing an incorrect first character.
3281
3282 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3283 but not actually doing anything yet.
3284
3285 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3286 as Perl does (e.g. [-az] or [az-]).
3287
3288 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3289 all possible positions.
3290
3291 5. Split up into different modules to avoid including unneeded functions in a
3292 compiled binary. However, compile and exec are still in one module. The "study"
3293 function is split off.
3294
3295 6. The character tables are now in a separate module whose source is generated
3296 by an auxiliary program - but can then be edited by hand if required. There are
3297 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3298 toupper() in the code.
3299
3300 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3301 make them global. Abolish the function for setting them, as the caller can now
3302 set them directly.
3303
3304
3305 Version 0.92 11-Sep-97
3306 ----------------------
3307
3308 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3309 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3310
3311 2. Caseless matching was not working in character classes if the characters in
3312 the pattern were in upper case.
3313
3314 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3315
3316 4. Make PCRE_ANCHORED public and accept as a compile option.
3317
3318 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3319 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3320 pass them.
3321
3322 6. Give an error if bad option bits passed at compile or run time.
3323
3324 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3325 pcretest to cause it to pass that flag.
3326
3327 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3328 options, and the first character, if set.
3329
3330 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3331
3332
3333 Version 0.91 10-Sep-97
3334 ----------------------
3335
3336 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3337 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3338
3339 2. PCRE was looping on encountering an indefinitely repeated back reference to
3340 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3341 Perl does - treats the match as successful.
3342
3343 ****

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