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Revision 373 - (show annotations) (download)
Fri Sep 5 10:25:46 2008 UTC (6 years, 1 month ago) by ph10
File size: 159729 byte(s)
Update the Virtual Pascal + BCC files for current versions.

1 ChangeLog for PCRE
2 ------------------
3
4 Version 7.8 25-Aug-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 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
39 and a #define of that name to empty if it is not externally set. This is to
40 allow users of MSVC to set it if necessary.
41
42 10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
43 the convenience functions in the pcre_get.c source file.
44
45 11. An option change at the start of a pattern that had top-level alternatives
46 could cause overwriting and/or a crash. This command provoked a crash in
47 some environments:
48
49 printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
50
51 This potential security problem was recorded as CVE-2008-2371.
52
53 12. For a pattern where the match had to start at the beginning or immediately
54 after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
55 pcre_dfa_exec() could read past the end of the passed subject if there was
56 no match. To help with detecting such bugs (e.g. with valgrind), I modified
57 pcretest so that it places the subject at the end of its malloc-ed buffer.
58
59 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
60 exec() might read past the end of the data buffer in UTF-8 mode.
61
62 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
63 the data contained the byte 0x85 as part of a UTF-8 character within its
64 first line. This applied both to normal and DFA matching.
65
66 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
67 /^[^d]*?$/8 failed to match "abc".
68
69 16. Added a missing copyright notice to pcrecpp_internal.h.
70
71 17. Make it more clear in the documentation that values returned from
72 pcre_exec() in ovector are byte offsets, not character counts.
73
74 18. Tidied a few places to stop certain compilers from issuing warnings.
75
76 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
77 supplied by Stefan Weber. I made a further small update for 7.8 because
78 there is a change of source arrangements: the pcre_searchfuncs.c module is
79 replaced by pcre_ucd.c.
80
81
82 Version 7.7 07-May-08
83 ---------------------
84
85 1. Applied Craig's patch to sort out a long long problem: "If we can't convert
86 a string to a long long, pretend we don't even have a long long." This is
87 done by checking for the strtoq, strtoll, and _strtoi64 functions.
88
89 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
90 pre-7.6 versions, which defined a global no_arg variable instead of putting
91 it in the RE class. (See also #8 below.)
92
93 3. Remove a line of dead code, identified by coverity and reported by Nuno
94 Lopes.
95
96 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
97
98 (1) The include/exclude patterns were being applied to the whole pathnames
99 of files, instead of just to the final components.
100
101 (2) If there was more than one level of directory, the subdirectories were
102 skipped unless they satisfied the include/exclude conditions. This is
103 inconsistent with GNU grep (and could even be seen as contrary to the
104 pcregrep specification - which I improved to make it absolutely clear).
105 The action now is always to scan all levels of directory, and just
106 apply the include/exclude patterns to regular files.
107
108 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
109 --exclude_dir in the tests to avoid scanning .svn directories.
110
111 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
112 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
113 doesn't support NULs in patterns.
114
115 7. Added some missing "const"s to declarations of static tables in
116 pcre_compile.c and pcre_dfa_exec.c.
117
118 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
119 caused by fix #2 above. (Subsequently also a second patch to fix the
120 first patch. And a third patch - this was a messy problem.)
121
122 9. Applied Craig's patch to remove the use of push_back().
123
124 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
125 matching function regexec().
126
127 11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
128 which, however, unlike Perl's \g{...}, are subroutine calls, not back
129 references. PCRE supports relative numbers with this syntax (I don't think
130 Oniguruma does).
131
132 12. Previously, a group with a zero repeat such as (...){0} was completely
133 omitted from the compiled regex. However, this means that if the group
134 was called as a subroutine from elsewhere in the pattern, things went wrong
135 (an internal error was given). Such groups are now left in the compiled
136 pattern, with a new opcode that causes them to be skipped at execution
137 time.
138
139 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
140 to the way PCRE behaves:
141
142 (a) A lone ] character is dis-allowed (Perl treats it as data).
143
144 (b) A back reference to an unmatched subpattern matches an empty string
145 (Perl fails the current match path).
146
147 (c) A data ] in a character class must be notated as \] because if the
148 first data character in a class is ], it defines an empty class. (In
149 Perl it is not possible to have an empty class.) The empty class []
150 never matches; it forces failure and is equivalent to (*FAIL) or (?!).
151 The negative empty class [^] matches any one character, independently
152 of the DOTALL setting.
153
154 14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
155 non-existent subpattern following a character class starting with ']' and
156 containing () gave an internal compiling error instead of "reference to
157 non-existent subpattern". Fortunately, when the pattern did exist, the
158 compiled code was correct. (When scanning forwards to check for the
159 existencd of the subpattern, it was treating the data ']' as terminating
160 the class, so got the count wrong. When actually compiling, the reference
161 was subsequently set up correctly.)
162
163 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
164 it was being rejected as not supported by pcre_dfa_exec(), even though
165 other assertions are supported. I have made pcre_dfa_exec() support
166 (*FAIL).
167
168 16. The implementation of 13c above involved the invention of a new opcode,
169 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
170 cannot be changed at match time, I realized I could make a small
171 improvement to matching performance by compiling OP_ALLANY instead of
172 OP_ANY for "." when DOTALL was set, and then removing the runtime tests
173 on the OP_ANY path.
174
175 17. Compiling pcretest on Windows with readline support failed without the
176 following two fixes: (1) Make the unistd.h include conditional on
177 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
178
179 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
180 ncurses library to be included for pcretest when ReadLine support is
181 requested, but also to allow for it to be overridden. This patch came from
182 Daniel Bergström.
183
184 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
185 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
186 any errors with the current Unicode tables. Thanks to Peter Kankowski for
187 spotting this.
188
189
190 Version 7.6 28-Jan-08
191 ---------------------
192
193 1. A character class containing a very large number of characters with
194 codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
195 overflow.
196
197 2. Patch to cut out the "long long" test in pcrecpp_unittest when
198 HAVE_LONG_LONG is not defined.
199
200 3. Applied Christian Ehrlicher's patch to update the CMake build files to
201 bring them up to date and include new features. This patch includes:
202
203 - Fixed PH's badly added libz and libbz2 support.
204 - Fixed a problem with static linking.
205 - Added pcredemo. [But later removed - see 7 below.]
206 - Fixed dftables problem and added an option.
207 - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
208 HAVE_LONG_LONG.
209 - Added readline support for pcretest.
210 - Added an listing of the option settings after cmake has run.
211
212 4. A user submitted a patch to Makefile that makes it easy to create
213 "pcre.dll" under mingw when using Configure/Make. I added stuff to
214 Makefile.am that cause it to include this special target, without
215 affecting anything else. Note that the same mingw target plus all
216 the other distribution libraries and programs are now supported
217 when configuring with CMake (see 6 below) instead of with
218 Configure/Make.
219
220 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
221 This is an attempt to solve the reported problem "pcrecpp::no_arg is not
222 exported in the Windows port". It has not yet been confirmed that the patch
223 solves the problem, but it does no harm.
224
225 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
226 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
227 with CMake, and also correct the comment about stack recursion.
228
229 7. Remove the automatic building of pcredemo from the ./configure system and
230 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
231 of a program that users should build themselves after PCRE is installed, so
232 building it automatically is not really right. What is more, it gave
233 trouble in some build environments.
234
235 8. Further tidies to CMakeLists.txt from Sheri and Christian.
236
237
238 Version 7.5 10-Jan-08
239 ---------------------
240
241 1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
242 values in parens when parsing an RE using the C++ wrapper."
243
244 2. Negative specials like \S did not work in character classes in UTF-8 mode.
245 Characters greater than 255 were excluded from the class instead of being
246 included.
247
248 3. The same bug as (2) above applied to negated POSIX classes such as
249 [:^space:].
250
251 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
252 defined or documented. It seems to have been a typo for PCRE_STATIC, so
253 I have changed it.
254
255 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
256 first named subpattern) and a construct such as (?&a) would reference the
257 first named subpattern whose name started with "a" (in other words, the
258 length check was missing). Both these problems are fixed. "Subpattern name
259 expected" is now given for (?&) (a zero-length name), and this patch also
260 makes it give the same error for \k'' (previously it complained that that
261 was a reference to a non-existent subpattern).
262
263 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
264 this is right because (?- can be followed by option settings as well as by
265 digits. I have, however, made the messages clearer.
266
267 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
268 than the number used in the conditional) now cause a compile-time error.
269 This is actually not compatible with Perl, which accepts such patterns, but
270 treats the conditional as always being FALSE (as PCRE used to), but it
271 seems to me that giving a diagnostic is better.
272
273 8. Change "alphameric" to the more common word "alphanumeric" in comments
274 and messages.
275
276 9. Fix two occurrences of "backslash" in comments that should have been
277 "backspace".
278
279 10. Remove two redundant lines of code that can never be obeyed (their function
280 was moved elsewhere).
281
282 11. The program that makes PCRE's Unicode character property table had a bug
283 which caused it to generate incorrect table entries for sequences of
284 characters that have the same character type, but are in different scripts.
285 It amalgamated them into a single range, with the script of the first of
286 them. In other words, some characters were in the wrong script. There were
287 thirteen such cases, affecting characters in the following ranges:
288
289 U+002b0 - U+002c1
290 U+0060c - U+0060d
291 U+0061e - U+00612
292 U+0064b - U+0065e
293 U+0074d - U+0076d
294 U+01800 - U+01805
295 U+01d00 - U+01d77
296 U+01d9b - U+01dbf
297 U+0200b - U+0200f
298 U+030fc - U+030fe
299 U+03260 - U+0327f
300 U+0fb46 - U+0fbb1
301 U+10450 - U+1049d
302
303 12. The -o option (show only the matching part of a line) for pcregrep was not
304 compatible with GNU grep in that, if there was more than one match in a
305 line, it showed only the first of them. It now behaves in the same way as
306 GNU grep.
307
308 13. If the -o and -v options were combined for pcregrep, it printed a blank
309 line for every non-matching line. GNU grep prints nothing, and pcregrep now
310 does the same. The return code can be used to tell if there were any
311 non-matching lines.
312
313 14. Added --file-offsets and --line-offsets to pcregrep.
314
315 15. The pattern (?=something)(?R) was not being diagnosed as a potentially
316 infinitely looping recursion. The bug was that positive lookaheads were not
317 being skipped when checking for a possible empty match (negative lookaheads
318 and both kinds of lookbehind were skipped).
319
320 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
321 inclusion of <windows.h> to before rather than after the definition of
322 INVALID_FILE_ATTRIBUTES (patch from David Byron).
323
324 17. Specifying a possessive quantifier with a specific limit for a Unicode
325 character property caused pcre_compile() to compile bad code, which led at
326 runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
327 are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
328 caused the error; without that there was no problem.
329
330 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
331
332 19. Added --enable-pcretest-libreadline.
333
334 20. In pcrecpp.cc, the variable 'count' was incremented twice in
335 RE::GlobalReplace(). As a result, the number of replacements returned was
336 double what it should be. I removed one of the increments, but Craig sent a
337 later patch that removed the other one (the right fix) and added unit tests
338 that check the return values (which was not done before).
339
340 21. Several CMake things:
341
342 (1) Arranged that, when cmake is used on Unix, the libraries end up with
343 the names libpcre and libpcreposix, not just pcre and pcreposix.
344
345 (2) The above change means that pcretest and pcregrep are now correctly
346 linked with the newly-built libraries, not previously installed ones.
347
348 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
349
350 22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
351 crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
352 UTF-8 newline character). The key issue is that the pattern starts .*;
353 this means that the match must be either at the beginning, or after a
354 newline. The bug was in the code for advancing after a failed match and
355 checking that the new position followed a newline. It was not taking
356 account of UTF-8 characters correctly.
357
358 23. PCRE was behaving differently from Perl in the way it recognized POSIX
359 character classes. PCRE was not treating the sequence [:...:] as a
360 character class unless the ... were all letters. Perl, however, seems to
361 allow any characters between [: and :], though of course it rejects as
362 unknown any "names" that contain non-letters, because all the known class
363 names consist only of letters. Thus, Perl gives an error for [[:1234:]],
364 for example, whereas PCRE did not - it did not recognize a POSIX character
365 class. This seemed a bit dangerous, so the code has been changed to be
366 closer to Perl. The behaviour is not identical to Perl, because PCRE will
367 diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
368 treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
369 Perl does, and where it didn't before.
370
371 24. Rewrite so as to remove the single use of %n from pcregrep because in some
372 Windows environments %n is disabled by default.
373
374
375 Version 7.4 21-Sep-07
376 ---------------------
377
378 1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
379 means that a class such as [\s] counted as "explicit reference to CR or
380 LF". That isn't really right - the whole point of the change was to try to
381 help when there was an actual mention of one of the two characters. So now
382 the change happens only if \r or \n (or a literal CR or LF) character is
383 encountered.
384
385 2. The 32-bit options word was also used for 6 internal flags, but the numbers
386 of both had grown to the point where there were only 3 bits left.
387 Fortunately, there was spare space in the data structure, and so I have
388 moved the internal flags into a new 16-bit field to free up more option
389 bits.
390
391 3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
392 but did not set the internal JCHANGED flag - either of these is enough to
393 control the way the "get" function works - but the PCRE_INFO_JCHANGED
394 facility is supposed to tell if (?J) was ever used, so now (?J) at the
395 start sets both bits.
396
397 4. Added options (at build time, compile time, exec time) to change \R from
398 matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
399
400 5. doc/pcresyntax.html was missing from the distribution.
401
402 6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
403 compatibility, even though it is no longer used.
404
405 7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
406 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
407 windows.h file is present (where different names are used). [This was
408 reversed later after testing - see 16 below.]
409
410 8. Changed all #include <config.h> to #include "config.h". There were also
411 some further <pcre.h> cases that I changed to "pcre.h".
412
413 9. When pcregrep was used with the --colour option, it missed the line ending
414 sequence off the lines that it output.
415
416 10. It was pointed out to me that arrays of string pointers cause lots of
417 relocations when a shared library is dynamically loaded. A technique of
418 using a single long string with a table of offsets can drastically reduce
419 these. I have refactored PCRE in four places to do this. The result is
420 dramatic:
421
422 Originally: 290
423 After changing UCP table: 187
424 After changing error message table: 43
425 After changing table of "verbs" 36
426 After changing table of Posix names 22
427
428 Thanks to the folks working on Gregex for glib for this insight.
429
430 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
431 unicode-properties was also set.
432
433 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
434
435 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
436 checked only for CRLF.
437
438 14. Added casts to pcretest.c to avoid compiler warnings.
439
440 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
441
442 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
443 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
444 entirely. This removes changes made in 7 above.
445
446 17. The CMake files have been updated, and there is now more information about
447 building with CMake in the NON-UNIX-USE document.
448
449
450 Version 7.3 28-Aug-07
451 ---------------------
452
453 1. In the rejigging of the build system that eventually resulted in 7.1, the
454 line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
455 brackets there is not right, since it causes compilers to look for an
456 installed pcre.h, not the version that is in the source that is being
457 compiled (which of course may be different). I have changed it back to:
458
459 #include "pcre.h"
460
461 I have a vague recollection that the change was concerned with compiling in
462 different directories, but in the new build system, that is taken care of
463 by the VPATH setting the Makefile.
464
465 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
466 when the subject happened to end in the byte 0x85 (e.g. if the last
467 character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
468 characters but of course it shouldn't be taken as a newline when it is part
469 of another character. The bug was that, for an unlimited repeat of . in
470 not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
471 characters when looking for a newline.
472
473 3. A small performance improvement in the DOTALL UTF-8 mode .* case.
474
475 4. Debugging: adjusted the names of opcodes for different kinds of parentheses
476 in debug output.
477
478 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
479 long printing in the pcrecpp unittest when running under MinGW.
480
481 6. ESC_K was left out of the EBCDIC table.
482
483 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
484 parentheses; I made it 1000, which seemed large enough. Unfortunately, the
485 limit also applies to "virtual nesting" when a pattern is recursive, and in
486 this case 1000 isn't so big. I have been able to remove this limit at the
487 expense of backing off one optimization in certain circumstances. Normally,
488 when pcre_exec() would call its internal match() function recursively and
489 immediately return the result unconditionally, it uses a "tail recursion"
490 feature to save stack. However, when a subpattern that can match an empty
491 string has an unlimited repetition quantifier, it no longer makes this
492 optimization. That gives it a stack frame in which to save the data for
493 checking that an empty string has been matched. Previously this was taken
494 from the 1000-entry workspace that had been reserved. So now there is no
495 explicit limit, but more stack is used.
496
497 8. Applied Daniel's patches to solve problems with the import/export magic
498 syntax that is required for Windows, and which was going wrong for the
499 pcreposix and pcrecpp parts of the library. These were overlooked when this
500 problem was solved for the main library.
501
502 9. There were some crude static tests to avoid integer overflow when computing
503 the size of patterns that contain repeated groups with explicit upper
504 limits. As the maximum quantifier is 65535, the maximum group length was
505 set at 30,000 so that the product of these two numbers did not overflow a
506 32-bit integer. However, it turns out that people want to use groups that
507 are longer than 30,000 bytes (though not repeat them that many times).
508 Change 7.0/17 (the refactoring of the way the pattern size is computed) has
509 made it possible to implement the integer overflow checks in a much more
510 dynamic way, which I have now done. The artificial limitation on group
511 length has been removed - we now have only the limit on the total length of
512 the compiled pattern, which depends on the LINK_SIZE setting.
513
514 10. Fixed a bug in the documentation for get/copy named substring when
515 duplicate names are permitted. If none of the named substrings are set, the
516 functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
517 empty string.
518
519 11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
520 instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
521 because the ] is interpreted as the first data character and the
522 terminating ] is not found. PCRE has been made compatible with Perl in this
523 regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
524 cause memory overwriting.
525
526 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
527 string has been matched (to stop an infinite loop). It was not recognizing
528 a conditional subpattern that could match an empty string if that
529 subpattern was within another subpattern. For example, it looped when
530 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
531 condition was not nested. This bug has been fixed.
532
533 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
534 past the start of the subject in the presence of bytes with the top bit
535 set, for example "\x8aBCD".
536
537 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
538 (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
539
540 14. Optimized (?!) to (*FAIL).
541
542 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
543 This restricts code points to be within the range 0 to 0x10FFFF, excluding
544 the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
545 full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
546 does: it's just the validity check that is more restrictive.
547
548 16. Inserted checks for integer overflows during escape sequence (backslash)
549 processing, and also fixed erroneous offset values for syntax errors during
550 backslash processing.
551
552 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
553 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
554
555 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
556 caused an overrun.
557
558 19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
559 something other than just ASCII characters) inside a group that had an
560 unlimited repeat caused a loop at compile time (while checking to see
561 whether the group could match an empty string).
562
563 20. Debugging a pattern containing \p or \P could cause a crash. For example,
564 [\P{Any}] did so. (Error in the code for printing property names.)
565
566 21. An orphan \E inside a character class could cause a crash.
567
568 22. A repeated capturing bracket such as (A)? could cause a wild memory
569 reference during compilation.
570
571 23. There are several functions in pcre_compile() that scan along a compiled
572 expression for various reasons (e.g. to see if it's fixed length for look
573 behind). There were bugs in these functions when a repeated \p or \P was
574 present in the pattern. These operators have additional parameters compared
575 with \d, etc, and these were not being taken into account when moving along
576 the compiled data. Specifically:
577
578 (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
579 length.
580
581 (b) An item such as \pL+ within a repeated group could cause crashes or
582 loops.
583
584 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
585 "reference to non-existent subpattern" error.
586
587 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
588
589 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
590 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
591
592 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
593
594 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
595 character were causing crashes (broken optimization).
596
597 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
598 \p or \P) caused a compile-time loop.
599
600 28. More problems have arisen in unanchored patterns when CRLF is a valid line
601 break. For example, the unstudied pattern [\r\n]A does not match the string
602 "\r\nA" because change 7.0/46 below moves the current point on by two
603 characters after failing to match at the start. However, the pattern \nA
604 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
605 the same is true. There doesn't seem any very clean way out of this, but
606 what I have chosen to do makes the common cases work: PCRE now takes note
607 of whether there can be an explicit match for \r or \n anywhere in the
608 pattern, and if so, 7.0/46 no longer applies. As part of this change,
609 there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
610 pattern has explicit CR or LF references.
611
612 29. Added (*CR) etc for changing newline setting at start of pattern.
613
614
615 Version 7.2 19-Jun-07
616 ---------------------
617
618 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
619 which is apparently normally available under Windows.
620
621 2. Re-jig the pcregrep tests with different newline settings in an attempt
622 to make them independent of the local environment's newline setting.
623
624 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
625
626 4. Some of the "internals" tests were previously cut out when the link size
627 was not 2, because the output contained actual offsets. The recent new
628 "Z" feature of pcretest means that these can be cut out, making the tests
629 usable with all link sizes.
630
631 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
632 stack recursion. This gives a massive performance boost under BSD, but just
633 a small improvement under Linux. However, it saves one field in the frame
634 in all cases.
635
636 6. Added more features from the forthcoming Perl 5.10:
637
638 (a) (?-n) (where n is a string of digits) is a relative subroutine or
639 recursion call. It refers to the nth most recently opened parentheses.
640
641 (b) (?+n) is also a relative subroutine call; it refers to the nth next
642 to be opened parentheses.
643
644 (c) Conditions that refer to capturing parentheses can be specified
645 relatively, for example, (?(-2)... or (?(+3)...
646
647 (d) \K resets the start of the current match so that everything before
648 is not part of it.
649
650 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
651
652 (f) \g{name} is another synonym - part of Perl 5.10's unification of
653 reference syntax.
654
655 (g) (?| introduces a group in which the numbering of parentheses in each
656 alternative starts with the same number.
657
658 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
659
660 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
661 PCRE_INFO_JCHANGED.
662
663 8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
664 terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
665 for detecting groups that can match an empty string.
666
667 9. A pattern with a very large number of alternatives (more than several
668 hundred) was running out of internal workspace during the pre-compile
669 phase, where pcre_compile() figures out how much memory will be needed. A
670 bit of new cunning has reduced the workspace needed for groups with
671 alternatives. The 1000-alternative test pattern now uses 12 bytes of
672 workspace instead of running out of the 4096 that are available.
673
674 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
675
676 11. Applied patch from Google to remove an optimization that didn't quite work.
677 The report of the bug said:
678
679 pcrecpp::RE("a*").FullMatch("aaa") matches, while
680 pcrecpp::RE("a*?").FullMatch("aaa") does not, and
681 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
682
683 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
684 it matched the wrong number of bytes.
685
686
687 Version 7.1 24-Apr-07
688 ---------------------
689
690 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
691 that is more "standard", making use of automake and other Autotools. There
692 is some re-arrangement of the files and adjustment of comments consequent
693 on this.
694
695 2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
696 for recursive directory scanning broke on some systems because the files
697 are not scanned in any specific order and on different systems the order
698 was different. A call to "sort" has been inserted into RunGrepTest for the
699 approprate test as a short-term fix. In the longer term there may be an
700 alternative.
701
702 3. I had an email from Eric Raymond about problems translating some of PCRE's
703 man pages to HTML (despite the fact that I distribute HTML pages, some
704 people do their own conversions for various reasons). The problems
705 concerned the use of low-level troff macros .br and .in. I have therefore
706 removed all such uses from the man pages (some were redundant, some could
707 be replaced by .nf/.fi pairs). The 132html script that I use to generate
708 HTML has been updated to handle .nf/.fi and to complain if it encounters
709 .br or .in.
710
711 4. Updated comments in configure.ac that get placed in config.h.in and also
712 arranged for config.h to be included in the distribution, with the name
713 config.h.generic, for the benefit of those who have to compile without
714 Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
715
716 5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
717 Weber: (1) pcre_internal.h was missing some function renames; (2) updated
718 makevp.bat for the current PCRE, using the additional files
719 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
720
721 6. A Windows user reported a minor discrepancy with test 2, which turned out
722 to be caused by a trailing space on an input line that had got lost in his
723 copy. The trailing space was an accident, so I've just removed it.
724
725 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
726 that is needed.
727
728 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
729 as "const" (a) because they are and (b) because it helps the PHP
730 maintainers who have recently made a script to detect big data structures
731 in the php code that should be moved to the .rodata section. I remembered
732 to update Builducptable as well, so it won't revert if ucptable.h is ever
733 re-created.
734
735 9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
736 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
737 order to be able to cut out the UTF-8 tables in the latter when UTF-8
738 support is not required. This saves 1.5-2K of code, which is important in
739 some applications.
740
741 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
742 so as not to refer to the tables, even though these functions will never be
743 called when UTF-8 support is disabled. Otherwise there are problems with a
744 shared library.
745
746 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
747
748 (a) It was defining its arguments as char * instead of void *.
749
750 (b) It was assuming that all moves were upwards in memory; this was true
751 a long time ago when I wrote it, but is no longer the case.
752
753 The emulated memove() is provided for those environments that have neither
754 memmove() nor bcopy(). I didn't think anyone used it these days, but that
755 is clearly not the case, as these two bugs were recently reported.
756
757 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
758 and Detrail to create the HTML documentation, the .txt form of the man
759 pages, and it removes trailing spaces from listed files. It also creates
760 pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
761 case, it wraps all the #defines with #ifndefs. This script should be run
762 before "make dist".
763
764 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
765 with Unicode property support.
766
767 (a) For a maximizing quantifier, if the two different cases of the
768 character were of different lengths in their UTF-8 codings (there are
769 some cases like this - I found 11), and the matching function had to
770 back up over a mixture of the two cases, it incorrectly assumed they
771 were both the same length.
772
773 (b) When PCRE was configured to use the heap rather than the stack for
774 recursion during matching, it was not correctly preserving the data for
775 the other case of a UTF-8 character when checking ahead for a match
776 while processing a minimizing repeat. If the check also involved
777 matching a wide character, but failed, corruption could cause an
778 erroneous result when trying to check for a repeat of the original
779 character.
780
781 13. Some tidying changes to the testing mechanism:
782
783 (a) The RunTest script now detects the internal link size and whether there
784 is UTF-8 and UCP support by running ./pcretest -C instead of relying on
785 values substituted by "configure". (The RunGrepTest script already did
786 this for UTF-8.) The configure.ac script no longer substitutes the
787 relevant variables.
788
789 (b) The debugging options /B and /D in pcretest show the compiled bytecode
790 with length and offset values. This means that the output is different
791 for different internal link sizes. Test 2 is skipped for link sizes
792 other than 2 because of this, bypassing the problem. Unfortunately,
793 there was also a test in test 3 (the locale tests) that used /B and
794 failed for link sizes other than 2. Rather than cut the whole test out,
795 I have added a new /Z option to pcretest that replaces the length and
796 offset values with spaces. This is now used to make test 3 independent
797 of link size. (Test 2 will be tidied up later.)
798
799 14. If erroroffset was passed as NULL to pcre_compile, it provoked a
800 segmentation fault instead of returning the appropriate error message.
801
802 15. In multiline mode when the newline sequence was set to "any", the pattern
803 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
804 This doesn't seem right; it now treats the CRLF combination as the line
805 ending, and so does not match in that case. It's only a pattern such as ^$
806 that would hit this one: something like ^ABC$ would have failed after \r
807 and then tried again after \r\n.
808
809 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
810 in an attempt to make files that differ only in their line terminators
811 compare equal. This works on Linux.
812
813 17. Under certain error circumstances pcregrep might try to free random memory
814 as it exited. This is now fixed, thanks to valgrind.
815
816 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
817 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
818 was because its rules for how to advance for /g after matching an empty
819 string at the end of a line did not allow for this case. They now check for
820 it specially.
821
822 20. pcretest is supposed to handle patterns and data of any length, by
823 extending its buffers when necessary. It was getting this wrong when the
824 buffer for a data line had to be extended.
825
826 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
827 CRLF as a newline sequence.
828
829 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
830 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
831 I have nevertheless tidied it up.
832
833 23. Added some casts to kill warnings from HP-UX ia64 compiler.
834
835 24. Added a man page for pcre-config.
836
837
838 Version 7.0 19-Dec-06
839 ---------------------
840
841 1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
842 moving to gcc 4.1.1.
843
844 2. The -S option for pcretest uses setrlimit(); I had omitted to #include
845 sys/time.h, which is documented as needed for this function. It doesn't
846 seem to matter on Linux, but it showed up on some releases of OS X.
847
848 3. It seems that there are systems where bytes whose values are greater than
849 127 match isprint() in the "C" locale. The "C" locale should be the
850 default when a C program starts up. In most systems, only ASCII printing
851 characters match isprint(). This difference caused the output from pcretest
852 to vary, making some of the tests fail. I have changed pcretest so that:
853
854 (a) When it is outputting text in the compiled version of a pattern, bytes
855 other than 32-126 are always shown as hex escapes.
856
857 (b) When it is outputting text that is a matched part of a subject string,
858 it does the same, unless a different locale has been set for the match
859 (using the /L modifier). In this case, it uses isprint() to decide.
860
861 4. Fixed a major bug that caused incorrect computation of the amount of memory
862 required for a compiled pattern when options that changed within the
863 pattern affected the logic of the preliminary scan that determines the
864 length. The relevant options are -x, and -i in UTF-8 mode. The result was
865 that the computed length was too small. The symptoms of this bug were
866 either the PCRE error "internal error: code overflow" from pcre_compile(),
867 or a glibc crash with a message such as "pcretest: free(): invalid next
868 size (fast)". Examples of patterns that provoked this bug (shown in
869 pcretest format) are:
870
871 /(?-x: )/x
872 /(?x)(?-x: \s*#\s*)/
873 /((?i)[\x{c0}])/8
874 /(?i:[\x{c0}])/8
875
876 HOWEVER: Change 17 below makes this fix obsolete as the memory computation
877 is now done differently.
878
879 5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
880 wrapper classes; (b) implement a new function in the C++ scanner that is
881 more efficient than the old way of doing things because it avoids levels of
882 recursion in the regex matching; (c) add a paragraph to the documentation
883 for the FullMatch() function.
884
885 6. The escape sequence \n was being treated as whatever was defined as
886 "newline". Not only was this contrary to the documentation, which states
887 that \n is character 10 (hex 0A), but it also went horribly wrong when
888 "newline" was defined as CRLF. This has been fixed.
889
890 7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
891 was being set to -1 for the "end of line" case (supposedly a value that no
892 character can have). Though this value is never used (the check for end of
893 line is "zero bytes in current character"), it caused compiler complaints.
894 I've changed it to 0xffffffff.
895
896 8. In pcre_version.c, the version string was being built by a sequence of
897 C macros that, in the event of PCRE_PRERELEASE being defined as an empty
898 string (as it is for production releases) called a macro with an empty
899 argument. The C standard says the result of this is undefined. The gcc
900 compiler treats it as an empty string (which was what was wanted) but it is
901 reported that Visual C gives an error. The source has been hacked around to
902 avoid this problem.
903
904 9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
905 builds of pcretest, and changed the call to _setmode() to use _O_BINARY
906 instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
907 of them did).
908
909 10. Originally, pcretest opened its input and output without "b"; then I was
910 told that "b" was needed in some environments, so it was added for release
911 5.0 to both the input and output. (It makes no difference on Unix-like
912 systems.) Later I was told that it is wrong for the input on Windows. I've
913 now abstracted the modes into two macros, to make it easier to fiddle with
914 them, and removed "b" from the input mode under Windows.
915
916 11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
917
918 12. Added -help and --help to pcretest as an official way of being reminded
919 of the options.
920
921 13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
922 and pcrecpp.cc because they annoy compilers at high warning levels.
923
924 14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
925
926 15. Fixed an occurrence of == in configure.ac that should have been = (shell
927 scripts are not C programs :-) and which was not noticed because it works
928 on Linux.
929
930 16. pcretest is supposed to handle any length of pattern and data line (as one
931 line or as a continued sequence of lines) by extending its input buffer if
932 necessary. This feature was broken for very long pattern lines, leading to
933 a string of junk being passed to pcre_compile() if the pattern was longer
934 than about 50K.
935
936 17. I have done a major re-factoring of the way pcre_compile() computes the
937 amount of memory needed for a compiled pattern. Previously, there was code
938 that made a preliminary scan of the pattern in order to do this. That was
939 OK when PCRE was new, but as the facilities have expanded, it has become
940 harder and harder to keep it in step with the real compile phase, and there
941 have been a number of bugs (see for example, 4 above). I have now found a
942 cunning way of running the real compile function in a "fake" mode that
943 enables it to compute how much memory it would need, while actually only
944 ever using a few hundred bytes of working memory and without too many
945 tests of the mode. This should make future maintenance and development
946 easier. A side effect of this work is that the limit of 200 on the nesting
947 depth of parentheses has been removed (though this was never a serious
948 limitation, I suspect). However, there is a downside: pcre_compile() now
949 runs more slowly than before (30% or more, depending on the pattern). I
950 hope this isn't a big issue. There is no effect on runtime performance.
951
952 18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
953 newline (only possible for the last line of a file) and it was a
954 pattern that set a locale (followed by /Lsomething), pcretest crashed.
955
956 19. Added additional timing features to pcretest. (1) The -tm option now times
957 matching only, not compiling. (2) Both -t and -tm can be followed, as a
958 separate command line item, by a number that specifies the number of
959 repeats to use when timing. The default is 50000; this gives better
960 precision, but takes uncomfortably long for very large patterns.
961
962 20. Extended pcre_study() to be more clever in cases where a branch of a
963 subpattern has no definite first character. For example, (a*|b*)[cd] would
964 previously give no result from pcre_study(). Now it recognizes that the
965 first character must be a, b, c, or d.
966
967 21. There was an incorrect error "recursive call could loop indefinitely" if
968 a subpattern (or the entire pattern) that was being tested for matching an
969 empty string contained only one non-empty item after a nested subpattern.
970 For example, the pattern (?>\x{100}*)\d(?R) provoked this error
971 incorrectly, because the \d was being skipped in the check.
972
973 22. The pcretest program now has a new pattern option /B and a command line
974 option -b, which is equivalent to adding /B to every pattern. This causes
975 it to show the compiled bytecode, without the additional information that
976 -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
977 is the same as /B/I).
978
979 23. A new optimization is now able automatically to treat some sequences such
980 as a*b as a*+b. More specifically, if something simple (such as a character
981 or a simple class like \d) has an unlimited quantifier, and is followed by
982 something that cannot possibly match the quantified thing, the quantifier
983 is automatically "possessified".
984
985 24. A recursive reference to a subpattern whose number was greater than 39
986 went wrong under certain circumstances in UTF-8 mode. This bug could also
987 have affected the operation of pcre_study().
988
989 25. Realized that a little bit of performance could be had by replacing
990 (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
991
992 26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
993
994 27. Possessive quantifiers such as a++ were previously implemented by turning
995 them into atomic groups such as ($>a+). Now they have their own opcodes,
996 which improves performance. This includes the automatically created ones
997 from 23 above.
998
999 28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1000 lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1001 the first matched character to be a colon. This applied both to named and
1002 numbered groups.
1003
1004 29. The ucpinternal.h header file was missing its idempotency #ifdef.
1005
1006 30. I was sent a "project" file called libpcre.a.dev which I understand makes
1007 building PCRE on Windows easier, so I have included it in the distribution.
1008
1009 31. There is now a check in pcretest against a ridiculously large number being
1010 returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1011 loop, the loop is abandoned.
1012
1013 32. Forward references to subpatterns in conditions such as (?(2)...) where
1014 subpattern 2 is defined later cause pcre_compile() to search forwards in
1015 the pattern for the relevant set of parentheses. This search went wrong
1016 when there were unescaped parentheses in a character class, parentheses
1017 escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1018
1019 33. "Subroutine" calls and backreferences were previously restricted to
1020 referencing subpatterns earlier in the regex. This restriction has now
1021 been removed.
1022
1023 34. Added a number of extra features that are going to be in Perl 5.10. On the
1024 whole, these are just syntactic alternatives for features that PCRE had
1025 previously implemented using the Python syntax or my own invention. The
1026 other formats are all retained for compatibility.
1027
1028 (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1029 as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1030 also .NET compatible.
1031
1032 (b) A recursion or subroutine call to a named group can now be defined as
1033 (?&name) as well as (?P>name).
1034
1035 (c) A backreference to a named group can now be defined as \k<name> or
1036 \k'name' as well as (?P=name). The new forms, as well as being in Perl
1037 5.10, are also .NET compatible.
1038
1039 (d) A conditional reference to a named group can now use the syntax
1040 (?(<name>) or (?('name') as well as (?(name).
1041
1042 (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1043 groups (named and numbered) that are never evaluated inline, but can be
1044 called as "subroutines" from elsewhere. In effect, the DEFINE condition
1045 is always false. There may be only one alternative in such a group.
1046
1047 (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1048 as the simple (?(R). The condition is true only if the most recent
1049 recursion is that of the given number or name. It does not search out
1050 through the entire recursion stack.
1051
1052 (g) The escape \gN or \g{N} has been added, where N is a positive or
1053 negative number, specifying an absolute or relative reference.
1054
1055 35. Tidied to get rid of some further signed/unsigned compiler warnings and
1056 some "unreachable code" warnings.
1057
1058 36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1059 things, this adds five new scripts.
1060
1061 37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1062 There were also incompatibilities regarding the handling of \Q..\E inside
1063 character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1064 hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1065
1066 38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1067 matches an empty string, and forcibly breaks the loop. There were bugs in
1068 this code in non-simple cases. For a pattern such as ^(a()*)* matched
1069 against aaaa the result was just "a" rather than "aaaa", for example. Two
1070 separate and independent bugs (that affected different cases) have been
1071 fixed.
1072
1073 39. Refactored the code to abolish the use of different opcodes for small
1074 capturing bracket numbers. This is a tidy that I avoided doing when I
1075 removed the limit on the number of capturing brackets for 3.5 back in 2001.
1076 The new approach is not only tidier, it makes it possible to reduce the
1077 memory needed to fix the previous bug (38).
1078
1079 40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1080 sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1081 processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1082 mode.
1083
1084 41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1085 report.
1086
1087 42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1088 copy construction and assignment in the C++ wrapper.
1089
1090 43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1091 couple of bugs that could have given wrong results in the "--newline=crlf"
1092 case.
1093
1094 44. Added a number of casts and did some reorganization of signed/unsigned int
1095 variables following suggestions from Dair Grant. Also renamed the variable
1096 "this" as "item" because it is a C++ keyword.
1097
1098 45. Arranged for dftables to add
1099
1100 #include "pcre_internal.h"
1101
1102 to pcre_chartables.c because without it, gcc 4.x may remove the array
1103 definition from the final binary if PCRE is built into a static library and
1104 dead code stripping is activated.
1105
1106 46. For an unanchored pattern, if a match attempt fails at the start of a
1107 newline sequence, and the newline setting is CRLF or ANY, and the next two
1108 characters are CRLF, advance by two characters instead of one.
1109
1110
1111 Version 6.7 04-Jul-06
1112 ---------------------
1113
1114 1. In order to handle tests when input lines are enormously long, pcretest has
1115 been re-factored so that it automatically extends its buffers when
1116 necessary. The code is crude, but this _is_ just a test program. The
1117 default size has been increased from 32K to 50K.
1118
1119 2. The code in pcre_study() was using the value of the re argument before
1120 testing it for NULL. (Of course, in any sensible call of the function, it
1121 won't be NULL.)
1122
1123 3. The memmove() emulation function in pcre_internal.h, which is used on
1124 systems that lack both memmove() and bcopy() - that is, hardly ever -
1125 was missing a "static" storage class specifier.
1126
1127 4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1128 containing an extended class (one that cannot be represented by a bitmap
1129 because it contains high-valued characters or Unicode property items, e.g.
1130 [\pZ]). Almost always one would set UTF-8 mode when processing such a
1131 pattern, but PCRE should not loop if you do not (it no longer does).
1132 [Detail: two cases were found: (a) a repeated subpattern containing an
1133 extended class; (b) a recursive reference to a subpattern that followed a
1134 previous extended class. It wasn't skipping over the extended class
1135 correctly when UTF-8 mode was not set.]
1136
1137 5. A negated single-character class was not being recognized as fixed-length
1138 in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1139 compile error "lookbehind assertion is not fixed length".
1140
1141 6. The RunPerlTest auxiliary script was showing an unexpected difference
1142 between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1143 write a Perl script that can interpret lines of an input file either as
1144 byte characters or as UTF-8, which is what "perltest" was being required to
1145 do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1146 can't do is switch easily at run time between having the "use utf8;" pragma
1147 or not. In the end, I fudged it by using the RunPerlTest script to insert
1148 "use utf8;" explicitly for the UTF-8 tests.
1149
1150 7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1151 the end of the subject string, contrary to the documentation and to what
1152 Perl does. This was true of both matching functions. Now it matches only at
1153 the start of the subject and immediately after *internal* newlines.
1154
1155 8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1156 a pointer to an int instead of a pointer to an unsigned long int. This
1157 caused problems on 64-bit systems.
1158
1159 9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1160 instance of the 'standard' template library not being so standard".
1161
1162 10. There was no check on the number of named subpatterns nor the maximum
1163 length of a subpattern name. The product of these values is used to compute
1164 the size of the memory block for a compiled pattern. By supplying a very
1165 long subpattern name and a large number of named subpatterns, the size
1166 computation could be caused to overflow. This is now prevented by limiting
1167 the length of names to 32 characters, and the number of named subpatterns
1168 to 10,000.
1169
1170 11. Subpatterns that are repeated with specific counts have to be replicated in
1171 the compiled pattern. The size of memory for this was computed from the
1172 length of the subpattern and the repeat count. The latter is limited to
1173 65535, but there was no limit on the former, meaning that integer overflow
1174 could in principle occur. The compiled length of a repeated subpattern is
1175 now limited to 30,000 bytes in order to prevent this.
1176
1177 12. Added the optional facility to have named substrings with the same name.
1178
1179 13. Added the ability to use a named substring as a condition, using the
1180 Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1181 are numbers (not recommended). Forward references are permitted.
1182
1183 14. Added forward references in named backreferences (if you see what I mean).
1184
1185 15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1186 pattern could run off the end of the subject. For example, the pattern
1187 "(?s)(.{1,5})"8 did this with the subject "ab".
1188
1189 16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1190 PCRE_CASELESS was set when matching characters that were quantified with ?
1191 or *.
1192
1193 17. A character class other than a single negated character that had a minimum
1194 but no maximum quantifier - for example [ab]{6,} - was not handled
1195 correctly by pce_dfa_exec(). It would match only one character.
1196
1197 18. A valid (though odd) pattern that looked like a POSIX character
1198 class but used an invalid character after [ (for example [[,abc,]]) caused
1199 pcre_compile() to give the error "Failed: internal error: code overflow" or
1200 in some cases to crash with a glibc free() error. This could even happen if
1201 the pattern terminated after [[ but there just happened to be a sequence of
1202 letters, a binary zero, and a closing ] in the memory that followed.
1203
1204 19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1205 over the years. Originally (before any Unicode support), just the bottom 8
1206 bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1207 output from "man perlunicode" includes this:
1208
1209 The regular expression compiler produces polymorphic opcodes. That
1210 is, the pattern adapts to the data and automatically switches to
1211 the Unicode character scheme when presented with Unicode data--or
1212 instead uses a traditional byte scheme when presented with byte
1213 data.
1214
1215 Sadly, a wide octal escape does not cause a switch, and in a string with
1216 no other multibyte characters, these octal escapes are treated as before.
1217 Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1218 /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1219 Unicode string.
1220
1221 I have not perpetrated such confusion in PCRE. Up till now, it took just
1222 the bottom 8 bits, as in old Perl. I have now made octal escapes with
1223 values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1224 translate to the appropriate multibyte character.
1225
1226 29. Applied some refactoring to reduce the number of warnings from Microsoft
1227 and Borland compilers. This has included removing the fudge introduced
1228 seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1229 a warning about an unused variable.
1230
1231 21. PCRE has not included VT (character 0x0b) in the set of whitespace
1232 characters since release 4.0, because Perl (from release 5.004) does not.
1233 [Or at least, is documented not to: some releases seem to be in conflict
1234 with the documentation.] However, when a pattern was studied with
1235 pcre_study() and all its branches started with \s, PCRE still included VT
1236 as a possible starting character. Of course, this did no harm; it just
1237 caused an unnecessary match attempt.
1238
1239 22. Removed a now-redundant internal flag bit that recorded the fact that case
1240 dependency changed within the pattern. This was once needed for "required
1241 byte" processing, but is no longer used. This recovers a now-scarce options
1242 bit. Also moved the least significant internal flag bit to the most-
1243 significant bit of the word, which was not previously used (hangover from
1244 the days when it was an int rather than a uint) to free up another bit for
1245 the future.
1246
1247 23. Added support for CRLF line endings as well as CR and LF. As well as the
1248 default being selectable at build time, it can now be changed at runtime
1249 via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1250 specify that it is scanning data with non-default line endings.
1251
1252 24. Changed the definition of CXXLINK to make it agree with the definition of
1253 LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1254
1255 25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1256 recursions. This makes a big different to stack usage for some patterns.
1257
1258 26. If a subpattern containing a named recursion or subroutine reference such
1259 as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1260 the space required for the compiled pattern went wrong and gave too small a
1261 value. Depending on the environment, this could lead to "Failed: internal
1262 error: code overflow at offset 49" or "glibc detected double free or
1263 corruption" errors.
1264
1265 27. Applied patches from Google (a) to support the new newline modes and (b) to
1266 advance over multibyte UTF-8 characters in GlobalReplace.
1267
1268 28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1269 difference for some implementation of PCRE in some Windows version.
1270
1271 29. Added some extra testing facilities to pcretest:
1272
1273 \q<number> in a data line sets the "match limit" value
1274 \Q<number> in a data line sets the "match recursion limt" value
1275 -S <number> sets the stack size, where <number> is in megabytes
1276
1277 The -S option isn't available for Windows.
1278
1279
1280 Version 6.6 06-Feb-06
1281 ---------------------
1282
1283 1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1284 in pcreposix.h. I have copied the definition from pcre.h.
1285
1286 2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1287 because pcre.h is no longer a built file.
1288
1289 3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1290 not normally included in the compiled code.
1291
1292
1293 Version 6.5 01-Feb-06
1294 ---------------------
1295
1296 1. When using the partial match feature with pcre_dfa_exec(), it was not
1297 anchoring the second and subsequent partial matches at the new starting
1298 point. This could lead to incorrect results. For example, with the pattern
1299 /1234/, partially matching against "123" and then "a4" gave a match.
1300
1301 2. Changes to pcregrep:
1302
1303 (a) All non-match returns from pcre_exec() were being treated as failures
1304 to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1305 error message is output. Some extra information is given for the
1306 PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1307 probably the only errors that are likely to be caused by users (by
1308 specifying a regex that has nested indefinite repeats, for instance).
1309 If there are more than 20 of these errors, pcregrep is abandoned.
1310
1311 (b) A binary zero was treated as data while matching, but terminated the
1312 output line if it was written out. This has been fixed: binary zeroes
1313 are now no different to any other data bytes.
1314
1315 (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1316 used to set a locale for matching. The --locale=xxxx long option has
1317 been added (no short equivalent) to specify a locale explicitly on the
1318 pcregrep command, overriding the environment variables.
1319
1320 (d) When -B was used with -n, some line numbers in the output were one less
1321 than they should have been.
1322
1323 (e) Added the -o (--only-matching) option.
1324
1325 (f) If -A or -C was used with -c (count only), some lines of context were
1326 accidentally printed for the final match.
1327
1328 (g) Added the -H (--with-filename) option.
1329
1330 (h) The combination of options -rh failed to suppress file names for files
1331 that were found from directory arguments.
1332
1333 (i) Added the -D (--devices) and -d (--directories) options.
1334
1335 (j) Added the -F (--fixed-strings) option.
1336
1337 (k) Allow "-" to be used as a file name for -f as well as for a data file.
1338
1339 (l) Added the --colo(u)r option.
1340
1341 (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1342 is not present by default.
1343
1344 3. A nasty bug was discovered in the handling of recursive patterns, that is,
1345 items such as (?R) or (?1), when the recursion could match a number of
1346 alternatives. If it matched one of the alternatives, but subsequently,
1347 outside the recursion, there was a failure, the code tried to back up into
1348 the recursion. However, because of the way PCRE is implemented, this is not
1349 possible, and the result was an incorrect result from the match.
1350
1351 In order to prevent this happening, the specification of recursion has
1352 been changed so that all such subpatterns are automatically treated as
1353 atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1354
1355 4. I had overlooked the fact that, in some locales, there are characters for
1356 which isalpha() is true but neither isupper() nor islower() are true. In
1357 the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1358 and ordfeminine) are like this. This affected the treatment of \w and \W
1359 when they appeared in character classes, but not when they appeared outside
1360 a character class. The bit map for "word" characters is now created
1361 separately from the results of isalnum() instead of just taking it from the
1362 upper, lower, and digit maps. (Plus the underscore character, of course.)
1363
1364 5. The above bug also affected the handling of POSIX character classes such as
1365 [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1366 permanent tables. Instead, the bit maps for such a class were previously
1367 created as the appropriate unions of the upper, lower, and digit bitmaps.
1368 Now they are created by subtraction from the [[:word:]] class, which has
1369 its own bitmap.
1370
1371 6. The [[:blank:]] character class matches horizontal, but not vertical space.
1372 It is created by subtracting the vertical space characters (\x09, \x0a,
1373 \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1374 subtraction was done in the overall bitmap for a character class, meaning
1375 that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1376 be recognized. This bug has been fixed.
1377
1378 7. Patches from the folks at Google:
1379
1380 (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1381 real life, but is still worth protecting against".
1382
1383 (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1384 regular expressions".
1385
1386 (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1387 have it.
1388
1389 (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1390 "configure" and the latter not, in order to fix a problem somebody had
1391 with compiling the Arg class on HP-UX.
1392
1393 (e) Improve the error-handling of the C++ wrapper a little bit.
1394
1395 (f) New tests for checking recursion limiting.
1396
1397 8. The pcre_memmove() function, which is used only if the environment does not
1398 have a standard memmove() function (and is therefore rarely compiled),
1399 contained two bugs: (a) use of int instead of size_t, and (b) it was not
1400 returning a result (though PCRE never actually uses the result).
1401
1402 9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1403 large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1404 returned instead of calling malloc() with an overflowing number that would
1405 most likely cause subsequent chaos.
1406
1407 10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1408
1409 11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1410 with this option is matched, the nmatch and pmatch options of regexec() are
1411 ignored.
1412
1413 12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1414 provided in case anyone wants to the the POSIX interface with UTF-8
1415 strings.
1416
1417 13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1418 C++ linking (needed for some HP-UX environments).
1419
1420 14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1421 (unused parameter) and in the pcre_printint() function (omitted "default"
1422 switch label when the default is to do nothing).
1423
1424 15. Added some code to make it possible, when PCRE is compiled as a C++
1425 library, to replace subject pointers for pcre_exec() with a smart pointer
1426 class, thus making it possible to process discontinuous strings.
1427
1428 16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1429 much the same function. They were added by different people who were trying
1430 to make PCRE easy to compile on non-Unix systems. It has been suggested
1431 that PCRE_EXPORT be abolished now that there is more automatic apparatus
1432 for compiling on Windows systems. I have therefore replaced it with
1433 PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1434 defaults to "extern" for C or "extern C" for C++, which works fine on
1435 Unix-like systems. It is now possible to override the value of PCRE_DATA_
1436 SCOPE with something explicit in config.h. In addition:
1437
1438 (a) pcreposix.h still had just "extern" instead of either of these macros;
1439 I have replaced it with PCRE_DATA_SCOPE.
1440
1441 (b) Functions such as _pcre_xclass(), which are internal to the library,
1442 but external in the C sense, all had PCRE_EXPORT in their definitions.
1443 This is apparently wrong for the Windows case, so I have removed it.
1444 (It makes no difference on Unix-like systems.)
1445
1446 17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1447 of recursive calls to match(). This is different to MATCH_LIMIT because
1448 that limits the total number of calls to match(), not all of which increase
1449 the depth of recursion. Limiting the recursion depth limits the amount of
1450 stack (or heap if NO_RECURSE is set) that is used. The default can be set
1451 when PCRE is compiled, and changed at run time. A patch from Google adds
1452 this functionality to the C++ interface.
1453
1454 18. Changes to the handling of Unicode character properties:
1455
1456 (a) Updated the table to Unicode 4.1.0.
1457
1458 (b) Recognize characters that are not in the table as "Cn" (undefined).
1459
1460 (c) I revised the way the table is implemented to a much improved format
1461 which includes recognition of ranges. It now supports the ranges that
1462 are defined in UnicodeData.txt, and it also amalgamates other
1463 characters into ranges. This has reduced the number of entries in the
1464 table from around 16,000 to around 3,000, thus reducing its size
1465 considerably. I realized I did not need to use a tree structure after
1466 all - a binary chop search is just as efficient. Having reduced the
1467 number of entries, I extended their size from 6 bytes to 8 bytes to
1468 allow for more data.
1469
1470 (d) Added support for Unicode script names via properties such as \p{Han}.
1471
1472 19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1473 matching that character.
1474
1475 20. When matching a repeated Unicode property with a minimum greater than zero,
1476 (for example \pL{2,}), PCRE could look past the end of the subject if it
1477 reached it while seeking the minimum number of characters. This could
1478 happen only if some of the characters were more than one byte long, because
1479 there is a check for at least the minimum number of bytes.
1480
1481 21. Refactored the implementation of \p and \P so as to be more general, to
1482 allow for more different types of property in future. This has changed the
1483 compiled form incompatibly. Anybody with saved compiled patterns that use
1484 \p or \P will have to recompile them.
1485
1486 22. Added "Any" and "L&" to the supported property types.
1487
1488 23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1489 but give a compile time error if the value is greater than 0xff.
1490
1491 24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1492 accidentally not being installed or uninstalled.
1493
1494 25. The pcre.h file was built from pcre.h.in, but the only changes that were
1495 made were to insert the current release number. This seemed silly, because
1496 it made things harder for people building PCRE on systems that don't run
1497 "configure". I have turned pcre.h into a distributed file, no longer built
1498 by "configure", with the version identification directly included. There is
1499 no longer a pcre.h.in file.
1500
1501 However, this change necessitated a change to the pcre-config script as
1502 well. It is built from pcre-config.in, and one of the substitutions was the
1503 release number. I have updated configure.ac so that ./configure now finds
1504 the release number by grepping pcre.h.
1505
1506 26. Added the ability to run the tests under valgrind.
1507
1508
1509 Version 6.4 05-Sep-05
1510 ---------------------
1511
1512 1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1513 "--" to be printed when multiple files were scanned, even when none of the
1514 -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1515 consider it to be a bug, and have restored the previous behaviour.
1516
1517 2. A couple of code tidies to get rid of compiler warnings.
1518
1519 3. The pcretest program used to cheat by referring to symbols in the library
1520 whose names begin with _pcre_. These are internal symbols that are not
1521 really supposed to be visible externally, and in some environments it is
1522 possible to suppress them. The cheating is now confined to including
1523 certain files from the library's source, which is a bit cleaner.
1524
1525 4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1526 file's purpose clearer.
1527
1528 5. Reorganized pcre_ucp_findchar().
1529
1530
1531 Version 6.3 15-Aug-05
1532 ---------------------
1533
1534 1. The file libpcre.pc.in did not have general read permission in the tarball.
1535
1536 2. There were some problems when building without C++ support:
1537
1538 (a) If C++ support was not built, "make install" and "make test" still
1539 tried to test it.
1540
1541 (b) There were problems when the value of CXX was explicitly set. Some
1542 changes have been made to try to fix these, and ...
1543
1544 (c) --disable-cpp can now be used to explicitly disable C++ support.
1545
1546 (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1547 backslash in a target when C++ was disabled. This confuses some
1548 versions of "make", apparently. Using an intermediate variable solves
1549 this. (Same for CPP_LOBJ.)
1550
1551 3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1552 (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1553 necessary on certain architectures.
1554
1555 4. Added a setting of -export-symbols-regex to the link command to remove
1556 those symbols that are exported in the C sense, but actually are local
1557 within the library, and not documented. Their names all begin with
1558 "_pcre_". This is not a perfect job, because (a) we have to except some
1559 symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1560 available (and never for static libraries). I have made a note to try to
1561 find a way round (a) in the future.
1562
1563
1564 Version 6.2 01-Aug-05
1565 ---------------------
1566
1567 1. There was no test for integer overflow of quantifier values. A construction
1568 such as {1111111111111111} would give undefined results. What is worse, if
1569 a minimum quantifier for a parenthesized subpattern overflowed and became
1570 negative, the calculation of the memory size went wrong. This could have
1571 led to memory overwriting.
1572
1573 2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1574
1575 3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1576 operating environments where this matters.
1577
1578 4. Applied Giuseppe Maxia's patch to add additional features for controlling
1579 PCRE options from within the C++ wrapper.
1580
1581 5. Named capturing subpatterns were not being correctly counted when a pattern
1582 was compiled. This caused two problems: (a) If there were more than 100
1583 such subpatterns, the calculation of the memory needed for the whole
1584 compiled pattern went wrong, leading to an overflow error. (b) Numerical
1585 back references of the form \12, where the number was greater than 9, were
1586 not recognized as back references, even though there were sufficient
1587 previous subpatterns.
1588
1589 6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1590 versions of gcc, e.g. 2.95.4.
1591
1592
1593 Version 6.1 21-Jun-05
1594 ---------------------
1595
1596 1. There was one reference to the variable "posix" in pcretest.c that was not
1597 surrounded by "#if !defined NOPOSIX".
1598
1599 2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1600 the cross-check on the old pcre_info() function, for the benefit of the
1601 cut-down version of PCRE that is currently imported into Exim.
1602
1603 3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1604 allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1605 patterns that start (?i) but I don't think that matters. The use of (?i) is
1606 just an example; this all applies to the other options as well.
1607
1608 4. Since libtool seems to echo the compile commands it is issuing, the output
1609 from "make" can be reduced a bit by putting "@" in front of each libtool
1610 compile command.
1611
1612 5. Patch from the folks at Google for configure.in to be a bit more thorough
1613 in checking for a suitable C++ installation before trying to compile the
1614 C++ stuff. This should fix a reported problem when a compiler was present,
1615 but no suitable headers.
1616
1617 6. The man pages all had just "PCRE" as their title. I have changed them to
1618 be the relevant file name. I have also arranged that these names are
1619 retained in the file doc/pcre.txt, which is a concatenation in text format
1620 of all the man pages except the little individual ones for each function.
1621
1622 7. The NON-UNIX-USE file had not been updated for the different set of source
1623 files that come with release 6. I also added a few comments about the C++
1624 wrapper.
1625
1626
1627 Version 6.0 07-Jun-05
1628 ---------------------
1629
1630 1. Some minor internal re-organization to help with my DFA experiments.
1631
1632 2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1633 didn't matter for the library itself when fully configured, but did matter
1634 when compiling without UCP support, or within Exim, where the ucp files are
1635 not imported.
1636
1637 3. Refactoring of the library code to split up the various functions into
1638 different source modules. The addition of the new DFA matching code (see
1639 below) to a single monolithic source would have made it really too
1640 unwieldy, quite apart from causing all the code to be include in a
1641 statically linked application, when only some functions are used. This is
1642 relevant even without the DFA addition now that patterns can be compiled in
1643 one application and matched in another.
1644
1645 The downside of splitting up is that there have to be some external
1646 functions and data tables that are used internally in different modules of
1647 the library but which are not part of the API. These have all had their
1648 names changed to start with "_pcre_" so that they are unlikely to clash
1649 with other external names.
1650
1651 4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1652 a different (DFA) algorithm. Although it is slower than the original
1653 function, it does have some advantages for certain types of matching
1654 problem.
1655
1656 5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1657 including restarting after a partial match.
1658
1659 6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1660 defined when compiling for Windows was sent to me. I have put it into the
1661 code, though I have no means of testing or verifying it.
1662
1663 7. Added the pcre_refcount() auxiliary function.
1664
1665 8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1666 match before or at the first newline in the subject string. In pcretest,
1667 the /f option on a pattern can be used to set this.
1668
1669 9. A repeated \w when used in UTF-8 mode with characters greater than 256
1670 would behave wrongly. This has been present in PCRE since release 4.0.
1671
1672 10. A number of changes to the pcregrep command:
1673
1674 (a) Refactored how -x works; insert ^(...)$ instead of setting
1675 PCRE_ANCHORED and checking the length, in preparation for adding
1676 something similar for -w.
1677
1678 (b) Added the -w (match as a word) option.
1679
1680 (c) Refactored the way lines are read and buffered so as to have more
1681 than one at a time available.
1682
1683 (d) Implemented a pcregrep test script.
1684
1685 (e) Added the -M (multiline match) option. This allows patterns to match
1686 over several lines of the subject. The buffering ensures that at least
1687 8K, or the rest of the document (whichever is the shorter) is available
1688 for matching (and similarly the previous 8K for lookbehind assertions).
1689
1690 (f) Changed the --help output so that it now says
1691
1692 -w, --word-regex(p)
1693
1694 instead of two lines, one with "regex" and the other with "regexp"
1695 because that confused at least one person since the short forms are the
1696 same. (This required a bit of code, as the output is generated
1697 automatically from a table. It wasn't just a text change.)
1698
1699 (g) -- can be used to terminate pcregrep options if the next thing isn't an
1700 option but starts with a hyphen. Could be a pattern or a path name
1701 starting with a hyphen, for instance.
1702
1703 (h) "-" can be given as a file name to represent stdin.
1704
1705 (i) When file names are being printed, "(standard input)" is used for
1706 the standard input, for compatibility with GNU grep. Previously
1707 "<stdin>" was used.
1708
1709 (j) The option --label=xxx can be used to supply a name to be used for
1710 stdin when file names are being printed. There is no short form.
1711
1712 (k) Re-factored the options decoding logic because we are going to add
1713 two more options that take data. Such options can now be given in four
1714 different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1715
1716 (l) Added the -A, -B, and -C options for requesting that lines of context
1717 around matches be printed.
1718
1719 (m) Added the -L option to print the names of files that do not contain
1720 any matching lines, that is, the complement of -l.
1721
1722 (n) The return code is 2 if any file cannot be opened, but pcregrep does
1723 continue to scan other files.
1724
1725 (o) The -s option was incorrectly implemented. For compatibility with other
1726 greps, it now suppresses the error message for a non-existent or non-
1727 accessible file (but not the return code). There is a new option called
1728 -q that suppresses the output of matching lines, which was what -s was
1729 previously doing.
1730
1731 (p) Added --include and --exclude options to specify files for inclusion
1732 and exclusion when recursing.
1733
1734 11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1735 Hopefully, it now does.
1736
1737 12. Missing cast in pcre_study().
1738
1739 13. Added an "uninstall" target to the makefile.
1740
1741 14. Replaced "extern" in the function prototypes in Makefile.in with
1742 "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1743 world, but is set differently for Windows.
1744
1745 15. Added a second compiling function called pcre_compile2(). The only
1746 difference is that it has an extra argument, which is a pointer to an
1747 integer error code. When there is a compile-time failure, this is set
1748 non-zero, in addition to the error test pointer being set to point to an
1749 error message. The new argument may be NULL if no error number is required
1750 (but then you may as well call pcre_compile(), which is now just a
1751 wrapper). This facility is provided because some applications need a
1752 numeric error indication, but it has also enabled me to tidy up the way
1753 compile-time errors are handled in the POSIX wrapper.
1754
1755 16. Added VPATH=.libs to the makefile; this should help when building with one
1756 prefix path and installing with another. (Or so I'm told by someone who
1757 knows more about this stuff than I do.)
1758
1759 17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1760 passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1761 match everything, including newlines. This is not POSIX-compatible, but
1762 somebody wanted the feature. From pcretest it can be activated by using
1763 both the P and the s flags.
1764
1765 18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1766
1767 19. libpcre.pc was being incorrectly installed as executable.
1768
1769 20. A couple of places in pcretest check for end-of-line by looking for '\n';
1770 it now also looks for '\r' so that it will work unmodified on Windows.
1771
1772 21. Added Google's contributed C++ wrapper to the distribution.
1773
1774 22. Added some untidy missing memory free() calls in pcretest, to keep
1775 Electric Fence happy when testing.
1776
1777
1778
1779 Version 5.0 13-Sep-04
1780 ---------------------
1781
1782 1. Internal change: literal characters are no longer packed up into items
1783 containing multiple characters in a single byte-string. Each character
1784 is now matched using a separate opcode. However, there may be more than one
1785 byte in the character in UTF-8 mode.
1786
1787 2. The pcre_callout_block structure has two new fields: pattern_position and
1788 next_item_length. These contain the offset in the pattern to the next match
1789 item, and its length, respectively.
1790
1791 3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1792 insertion of callouts before each pattern item. Added the /C option to
1793 pcretest to make use of this.
1794
1795 4. On the advice of a Windows user, the lines
1796
1797 #if defined(_WIN32) || defined(WIN32)
1798 _setmode( _fileno( stdout ), 0x8000 );
1799 #endif /* defined(_WIN32) || defined(WIN32) */
1800
1801 have been added to the source of pcretest. This apparently does useful
1802 magic in relation to line terminators.
1803
1804 5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1805 for the benefit of those environments where the "b" makes a difference.
1806
1807 6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1808 to know about it. I have put a hack into configure.in that adds in code
1809 to set GCC=yes if CC=icc. This seems to end up at a point in the
1810 generated configure script that is early enough to affect the setting of
1811 compiler options, which is what is needed, but I have no means of testing
1812 whether it really works. (The user who reported this had patched the
1813 generated configure script, which of course I cannot do.)
1814
1815 LATER: After change 22 below (new libtool files), the configure script
1816 seems to know about icc (and also ecc). Therefore, I have commented out
1817 this hack in configure.in.
1818
1819 7. Added support for pkg-config (2 patches were sent in).
1820
1821 8. Negated POSIX character classes that used a combination of internal tables
1822 were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1823 [[:^ascii]]. Typically, they would match almost any characters. The other
1824 POSIX classes were not broken in this way.
1825
1826 9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1827 to find the match, as PCRE was deluded into thinking that the match had to
1828 start at the start point or following a newline. The same bug applied to
1829 patterns with negative forward assertions or any backward assertions
1830 preceding ".*" at the start, unless the pattern required a fixed first
1831 character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1832
1833 10. In UTF-8 mode, when moving forwards in the subject after a failed match
1834 starting at the last subject character, bytes beyond the end of the subject
1835 string were read.
1836
1837 11. Renamed the variable "class" as "classbits" to make life easier for C++
1838 users. (Previously there was a macro definition, but it apparently wasn't
1839 enough.)
1840
1841 12. Added the new field "tables" to the extra data so that tables can be passed
1842 in at exec time, or the internal tables can be re-selected. This allows
1843 a compiled regex to be saved and re-used at a later time by a different
1844 program that might have everything at different addresses.
1845
1846 13. Modified the pcre-config script so that, when run on Solaris, it shows a
1847 -R library as well as a -L library.
1848
1849 14. The debugging options of pcretest (-d on the command line or D on a
1850 pattern) showed incorrect output for anything following an extended class
1851 that contained multibyte characters and which was followed by a quantifier.
1852
1853 15. Added optional support for general category Unicode character properties
1854 via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1855 support. It adds about 90K to the size of the library. The meanings of the
1856 inbuilt class escapes such as \d and \s have NOT been changed.
1857
1858 16. Updated pcredemo.c to include calls to free() to release the memory for the
1859 compiled pattern.
1860
1861 17. The generated file chartables.c was being created in the source directory
1862 instead of in the building directory. This caused the build to fail if the
1863 source directory was different from the building directory, and was
1864 read-only.
1865
1866 18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1867 file. No doubt somebody will tell me if they don't make sense... Also added
1868 Dan Mooney's comments about building on OpenVMS.
1869
1870 19. Added support for partial matching via the PCRE_PARTIAL option for
1871 pcre_exec() and the \P data escape in pcretest.
1872
1873 20. Extended pcretest with 3 new pattern features:
1874
1875 (i) A pattern option of the form ">rest-of-line" causes pcretest to
1876 write the compiled pattern to the file whose name is "rest-of-line".
1877 This is a straight binary dump of the data, with the saved pointer to
1878 the character tables forced to be NULL. The study data, if any, is
1879 written too. After writing, pcretest reads a new pattern.
1880
1881 (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1882 compiled pattern from the given file. There must not be any
1883 occurrences of "<" in the file name (pretty unlikely); if there are,
1884 pcretest will instead treat the initial "<" as a pattern delimiter.
1885 After reading in the pattern, pcretest goes on to read data lines as
1886 usual.
1887
1888 (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1889 and 16-bit fields in a compiled pattern, to simulate a pattern that
1890 was compiled on a host of opposite endianness.
1891
1892 21. The pcre-exec() function can now cope with patterns that were compiled on
1893 hosts of opposite endianness, with this restriction:
1894
1895 As for any compiled expression that is saved and used later, the tables
1896 pointer field cannot be preserved; the extra_data field in the arguments
1897 to pcre_exec() should be used to pass in a tables address if a value
1898 other than the default internal tables were used at compile time.
1899
1900 22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1901 now diagnosed as an error. Previously, most of the time, a negative number
1902 would have been treated as zero, but if in addition "ovector" was passed as
1903 NULL, a crash could occur.
1904
1905 23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1906 new versions from the libtool 1.5 distribution (the last one is a copy of
1907 a file called libtool.m4). This seems to have fixed the need to patch
1908 "configure" to support Darwin 1.3 (which I used to do). However, I still
1909 had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1910 workstation).
1911
1912 24. Changed the PCRE licence to be the more standard "BSD" licence.
1913
1914
1915 Version 4.5 01-Dec-03
1916 ---------------------
1917
1918 1. There has been some re-arrangement of the code for the match() function so
1919 that it can be compiled in a version that does not call itself recursively.
1920 Instead, it keeps those local variables that need separate instances for
1921 each "recursion" in a frame on the heap, and gets/frees frames whenever it
1922 needs to "recurse". Keeping track of where control must go is done by means
1923 of setjmp/longjmp. The whole thing is implemented by a set of macros that
1924 hide most of the details from the main code, and operates only if
1925 NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1926 "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1927 operating.
1928
1929 To make it easier for callers to provide specially tailored get/free
1930 functions for this usage, two new functions, pcre_stack_malloc, and
1931 pcre_stack_free, are used. They are always called in strict stacking order,
1932 and the size of block requested is always the same.
1933
1934 The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1935 PCRE has been compiled to use the stack or the heap for recursion. The
1936 -C option of pcretest uses this to show which version is compiled.
1937
1938 A new data escape \S, is added to pcretest; it causes the amounts of store
1939 obtained and freed by both kinds of malloc/free at match time to be added
1940 to the output.
1941
1942 2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1943 what's available on my current Linux desktop machine.
1944
1945 3. When matching a UTF-8 string, the test for a valid string at the start has
1946 been extended. If start_offset is not zero, PCRE now checks that it points
1947 to a byte that is the start of a UTF-8 character. If not, it returns
1948 PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1949 this is necessary because there may be backward assertions in the pattern.
1950 When matching the same subject several times, it may save resources to use
1951 PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1952
1953 4. The code for checking the validity of UTF-8 strings has been tightened so
1954 that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1955 containing "overlong sequences".
1956
1957 5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1958 I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1959 should have been "&", but it just so happened that all the cases this let
1960 through by mistake were picked up later in the function.
1961
1962 6. I had used a variable called "isblank" - this is a C99 function, causing
1963 some compilers to warn. To avoid this, I renamed it (as "blankclass").
1964
1965 7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1966 prompting; (b) run "./pcretest /dev/null" at the start of the test script
1967 so the version is shown; (c) stop "make test" echoing "./RunTest".
1968
1969 8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1970
1971 9. The prototype for memmove() for systems that don't have it was using
1972 size_t, but the inclusion of the header that defines size_t was later. I've
1973 moved the #includes for the C headers earlier to avoid this.
1974
1975 10. Added some adjustments to the code to make it easier to compiler on certain
1976 special systems:
1977
1978 (a) Some "const" qualifiers were missing.
1979 (b) Added the macro EXPORT before all exported functions; by default this
1980 is defined to be empty.
1981 (c) Changed the dftables auxiliary program (that builds chartables.c) so
1982 that it reads its output file name as an argument instead of writing
1983 to the standard output and assuming this can be redirected.
1984
1985 11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1986 class containing characters with values greater than 255, PCRE compilation
1987 went into a loop.
1988
1989 12. A recursive reference to a subpattern that was within another subpattern
1990 that had a minimum quantifier of zero caused PCRE to crash. For example,
1991 (x(y(?2))z)? provoked this bug with a subject that got as far as the
1992 recursion. If the recursively-called subpattern itself had a zero repeat,
1993 that was OK.
1994
1995 13. In pcretest, the buffer for reading a data line was set at 30K, but the
1996 buffer into which it was copied (for escape processing) was still set at
1997 1024, so long lines caused crashes.
1998
1999 14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2000 "internal error: code overflow...". This applied to any character class
2001 that was followed by a possessive quantifier.
2002
2003 15. Modified the Makefile to add libpcre.la as a prerequisite for
2004 libpcreposix.la because I was told this is needed for a parallel build to
2005 work.
2006
2007 16. If a pattern that contained .* following optional items at the start was
2008 studied, the wrong optimizing data was generated, leading to matching
2009 errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2010 matching string must start with a or b or c. The correct conclusion for
2011 this pattern is that a match can start with any character.
2012
2013
2014 Version 4.4 13-Aug-03
2015 ---------------------
2016
2017 1. In UTF-8 mode, a character class containing characters with values between
2018 127 and 255 was not handled correctly if the compiled pattern was studied.
2019 In fixing this, I have also improved the studying algorithm for such
2020 classes (slightly).
2021
2022 2. Three internal functions had redundant arguments passed to them. Removal
2023 might give a very teeny performance improvement.
2024
2025 3. Documentation bug: the value of the capture_top field in a callout is *one
2026 more than* the number of the hightest numbered captured substring.
2027
2028 4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2029 in incorrectly linking with a previously installed version. They now link
2030 explicitly with libpcre.la.
2031
2032 5. configure.in no longer needs to recognize Cygwin specially.
2033
2034 6. A problem in pcre.in for Windows platforms is fixed.
2035
2036 7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2037 pcretest, it used to include the size of the study block as part of its
2038 output. Unfortunately, the structure contains a field that has a different
2039 size on different hardware architectures. This meant that the tests that
2040 showed this size failed. As the block is currently always of a fixed size,
2041 this information isn't actually particularly useful in pcretest output, so
2042 I have just removed it.
2043
2044 8. Three pre-processor statements accidentally did not start in column 1.
2045 Sadly, there are *still* compilers around that complain, even though
2046 standard C has not required this for well over a decade. Sigh.
2047
2048 9. In pcretest, the code for checking callouts passed small integers in the
2049 callout_data field, which is a void * field. However, some picky compilers
2050 complained about the casts involved for this on 64-bit systems. Now
2051 pcretest passes the address of the small integer instead, which should get
2052 rid of the warnings.
2053
2054 10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2055 both compile and run time, and gives an error if an invalid UTF-8 sequence
2056 is found. There is a option for disabling this check in cases where the
2057 string is known to be correct and/or the maximum performance is wanted.
2058
2059 11. In response to a bug report, I changed one line in Makefile.in from
2060
2061 -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2062 to
2063 -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2064
2065 to look similar to other lines, but I have no way of telling whether this
2066 is the right thing to do, as I do not use Windows. No doubt I'll get told
2067 if it's wrong...
2068
2069
2070 Version 4.3 21-May-03
2071 ---------------------
2072
2073 1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2074 Makefile.
2075
2076 2. Some refactoring to improve the quality of the code:
2077
2078 (i) The utf8_table... variables are now declared "const".
2079
2080 (ii) The code for \cx, which used the "case flipping" table to upper case
2081 lower case letters, now just substracts 32. This is ASCII-specific,
2082 but the whole concept of \cx is ASCII-specific, so it seems
2083 reasonable.
2084
2085 (iii) PCRE was using its character types table to recognize decimal and
2086 hexadecimal digits in the pattern. This is silly, because it handles
2087 only 0-9, a-f, and A-F, but the character types table is locale-
2088 specific, which means strange things might happen. A private
2089 table is now used for this - though it costs 256 bytes, a table is
2090 much faster than multiple explicit tests. Of course, the standard
2091 character types table is still used for matching digits in subject
2092 strings against \d.
2093
2094 (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2095 ending in _t are). So I've renamed it as ESC_tee.
2096
2097 3. The first argument for regexec() in the POSIX wrapper should have been
2098 defined as "const".
2099
2100 4. Changed pcretest to use malloc() for its buffers so that they can be
2101 Electric Fenced for debugging.
2102
2103 5. There were several places in the code where, in UTF-8 mode, PCRE would try
2104 to read one or more bytes before the start of the subject string. Often this
2105 had no effect on PCRE's behaviour, but in some circumstances it could
2106 provoke a segmentation fault.
2107
2108 6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2109 to try to read one or more bytes before the start of the subject string.
2110
2111 7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2112 UTF-8 support could misbehave in various ways if the subject string
2113 contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2114 area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2115 back over UTF-8 characters.)
2116
2117
2118 Version 4.2 14-Apr-03
2119 ---------------------
2120
2121 1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2122
2123 2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2124 [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2125 [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2126 [WIN_PREFIX]: new variable, "cyg" for Cygwin
2127 * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2128 and BUILD_EXEEXT
2129 Note: automatic setting of the BUILD variables is not yet working
2130 set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2131 compile-time but not at link-time
2132 [LINK]: use for linking executables only
2133 make different versions for Windows and non-Windows
2134 [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2135 libraries
2136 [LINK_FOR_BUILD]: new variable
2137 [OBJEXT]: use throughout
2138 [EXEEXT]: use throughout
2139 <winshared>: new target
2140 <wininstall>: new target
2141 <dftables.o>: use native compiler
2142 <dftables>: use native linker
2143 <install>: handle Windows platform correctly
2144 <clean>: ditto
2145 <check>: ditto
2146 copy DLL to top builddir before testing
2147
2148 As part of these changes, -no-undefined was removed again. This was reported
2149 to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2150 in any case.
2151
2152 3. Some tidies to get rid of compiler warnings:
2153
2154 . In the match_data structure, match_limit was an unsigned long int, whereas
2155 match_call_count was an int. I've made them both unsigned long ints.
2156
2157 . In pcretest the fact that a const uschar * doesn't automatically cast to
2158 a void * provoked a warning.
2159
2160 . Turning on some more compiler warnings threw up some "shadow" variables
2161 and a few more missing casts.
2162
2163 4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2164 option, a class that contained a single character with a value between 128
2165 and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2166
2167 5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2168 option, a class that contained several characters, but with at least one
2169 whose value was between 128 and 255 caused PCRE to crash.
2170
2171
2172 Version 4.1 12-Mar-03
2173 ---------------------
2174
2175 1. Compiling with gcc -pedantic found a couple of places where casts were
2176 needed, and a string in dftables.c that was longer than standard compilers are
2177 required to support.
2178
2179 2. Compiling with Sun's compiler found a few more places where the code could
2180 be tidied up in order to avoid warnings.
2181
2182 3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2183 first of these names is deprecated in the latest Autoconf in favour of the name
2184 CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2185 compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2186 analogy I have changed it to CFLAGS_FOR_BUILD.
2187
2188 4. Added -no-undefined to the linking command in the Makefile, because this is
2189 apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2190 linking step for the pcreposix library.
2191
2192 5. PCRE was failing to diagnose the case of two named groups with the same
2193 name.
2194
2195 6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2196 literal character that is needed in the subject for a match, and scans along to
2197 ensure that it is present before embarking on the full matching process. This
2198 saves time in cases of nested unlimited repeats that are never going to match.
2199 Problem: the scan can take a lot of time if the subject is very long (e.g.
2200 megabytes), thus penalizing straightforward matches. It is now done only if the
2201 amount of subject to be scanned is less than 1000 bytes.
2202
2203 7. A lesser problem with the same optimization is that it was recording the
2204 first character of an anchored pattern as "needed", thus provoking a search
2205 right along the subject, even when the first match of the pattern was going to
2206 fail. The "needed" character is now not set for anchored patterns, unless it
2207 follows something in the pattern that is of non-fixed length. Thus, it still
2208 fulfils its original purpose of finding quick non-matches in cases of nested
2209 unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2210
2211
2212 Version 4.0 17-Feb-03
2213 ---------------------
2214
2215 1. If a comment in an extended regex that started immediately after a meta-item
2216 extended to the end of string, PCRE compiled incorrect data. This could lead to
2217 all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2218
2219 2. Moved to autoconf 2.53 and libtool 1.4.2.
2220
2221 3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2222 the special perltest8 script is no longer needed - all the tests can be run
2223 from a single perltest script.
2224
2225 4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2226 by \s. It has now been removed in PCRE. This means it isn't recognized as
2227 whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2228 class [:space:] *does* include VT, thereby creating a mess.
2229
2230 5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2231 space and tab.
2232
2233 6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2234 its new features into the main test script, reducing the number of scripts.
2235
2236 7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2237 were backward compatible, and made the (?i) apply to the whole pattern, as if
2238 /i were given. Now it behaves more logically, and applies the option setting
2239 only to what follows. PCRE has been changed to follow suit. However, if it
2240 finds options settings right at the start of the pattern, it extracts them into
2241 the global options, as before. Thus, they show up in the info data.
2242
2243 8. Added support for the \Q...\E escape sequence. Characters in between are
2244 treated as literals. This is slightly different from Perl in that $ and @ are
2245 also handled as literals inside the quotes. In Perl, they will cause variable
2246 interpolation. Note the following examples:
2247
2248 Pattern PCRE matches Perl matches
2249
2250 \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2251 \Qabc\$xyz\E abc\$xyz abc\$xyz
2252 \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2253
2254 For compatibility with Perl, \Q...\E sequences are recognized inside character
2255 classes as well as outside them.
2256
2257 9. Re-organized 3 code statements in pcretest to avoid "overflow in
2258 floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2259 (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2260 signed/unsigned warnings.
2261
2262 10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2263 option for pcretest, so I've replaced it by a simple function that does just
2264 that job.
2265
2266 11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2267 "pcregrep -".
2268
2269 12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2270 Java package. This provides some syntactic sugar for simple cases of what my
2271 documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2272 as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2273 item, you can use this simplified notation. Note that only makes sense with
2274 greedy quantifiers. Consequently, the use of the possessive quantifier forces
2275 greediness, whatever the setting of the PCRE_UNGREEDY option.
2276
2277 13. A change of greediness default within a pattern was not taking effect at
2278 the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2279 subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2280 was abstracted outside.
2281
2282 14. PCRE now supports the \G assertion. It is true when the current matching
2283 position is at the start point of the match. This differs from \A when the
2284 starting offset is non-zero. Used with the /g option of pcretest (or similar
2285 code), it works in the same way as it does for Perl's /g option. If all
2286 alternatives of a regex begin with \G, the expression is anchored to the start
2287 match position, and the "anchored" flag is set in the compiled expression.
2288
2289 15. Some bugs concerning the handling of certain option changes within patterns
2290 have been fixed. These applied to options other than (?ims). For example,
2291 "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2292 been the other way round. Some of this was related to change 7 above.
2293
2294 16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2295 features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2296 and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2297 POSIX classes only within a class (e.g. /[[:alpha:]]/).
2298
2299 17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2300 mode. Unlike ".", it always matches newline, whatever the setting of
2301 PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2302 assertions. Perl allows it, but it doesn't (in general) work because it can't
2303 calculate the length of the lookbehind. At least, that's the case for Perl
2304 5.8.0 - I've been told they are going to document that it doesn't work in
2305 future.
2306
2307 18. Added an error diagnosis for escapes that PCRE does not support: these are
2308 \L, \l, \N, \P, \p, \U, \u, and \X.
2309
2310 19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2311 reading past the end of the pattern in cases such as /[abcd/.
2312
2313 20. PCRE was getting more memory than necessary for patterns with classes that
2314 contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2315
2316 21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2317 compiling PCRE for use with Virtual Pascal.
2318
2319 22. Small fix to the Makefile to make it work properly if the build is done
2320 outside the source tree.
2321
2322 23. Added a new extension: a condition to go with recursion. If a conditional
2323 subpattern starts with (?(R) the "true" branch is used if recursion has
2324 happened, whereas the "false" branch is used only at the top level.
2325
2326 24. When there was a very long string of literal characters (over 255 bytes
2327 without UTF support, over 250 bytes with UTF support), the computation of how
2328 much memory was required could be incorrect, leading to segfaults or other
2329 strange effects.
2330
2331 25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2332 start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2333 there was a subsequent back reference to those brackets. This meant that, for
2334 example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2335 possible to check for precisely this case. All we can do is abandon the
2336 optimization if .* occurs inside capturing brackets when there are any back
2337 references whatsoever. (See below for a better fix that came later.)
2338
2339 26. The handling of the optimization for finding the first character of a
2340 non-anchored pattern, and for finding a character that is required later in the
2341 match were failing in some cases. This didn't break the matching; it just
2342 failed to optimize when it could. The way this is done has been re-implemented.
2343
2344 27. Fixed typo in error message for invalid (?R item (it said "(?p").
2345
2346 28. Added a new feature that provides some of the functionality that Perl
2347 provides with (?{...}). The facility is termed a "callout". The way it is done
2348 in PCRE is for the caller to provide an optional function, by setting
2349 pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2350 global variable. By default it is unset, which disables all calling out. To get
2351 the function called, the regex must include (?C) at appropriate points. This
2352 is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2353 This provides a means of identifying different callout points. When PCRE
2354 reaches such a point in the regex, if pcre_callout has been set, the external
2355 function is called. It is provided with data in a structure called
2356 pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2357 matching continues; if it returns a non-zero value, the match at the current
2358 point fails. However, backtracking will occur if possible. [This was changed
2359 later and other features added - see item 49 below.]
2360
2361 29. pcretest is upgraded to test the callout functionality. It provides a
2362 callout function that displays information. By default, it shows the start of
2363 the match and the current position in the text. There are some new data escapes
2364 to vary what happens:
2365
2366 \C+ in addition, show current contents of captured substrings
2367 \C- do not supply a callout function
2368 \C!n return 1 when callout number n is reached
2369 \C!n!m return 1 when callout number n is reached for the mth time
2370
2371 30. If pcregrep was called with the -l option and just a single file name, it
2372 output "<stdin>" if a match was found, instead of the file name.
2373
2374 31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2375 slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2376 pcre_exec(). This saves a malloc/free per call. The default value of
2377 POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2378 when configuring.
2379
2380 32. The default maximum size of a compiled pattern is 64K. There have been a
2381 few cases of people hitting this limit. The code now uses macros to handle the
2382 storing of links as offsets within the compiled pattern. It defaults to 2-byte
2383 links, but this can be changed to 3 or 4 bytes by --with-link-size when
2384 configuring. Tests 2 and 5 work only with 2-byte links because they output
2385 debugging information about compiled patterns.
2386
2387 33. Internal code re-arrangements:
2388
2389 (a) Moved the debugging function for printing out a compiled regex into
2390 its own source file (printint.c) and used #include to pull it into
2391 pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2392 separate copies.
2393
2394 (b) Defined the list of op-code names for debugging as a macro in
2395 internal.h so that it is next to the definition of the opcodes.
2396
2397 (c) Defined a table of op-code lengths for simpler skipping along compiled
2398 code. This is again a macro in internal.h so that it is next to the
2399 definition of the opcodes.
2400
2401 34. Added support for recursive calls to individual subpatterns, along the
2402 lines of Robin Houston's patch (but implemented somewhat differently).
2403
2404 35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2405 allow it to read and process whole directories in Win32. This code was
2406 contributed by Lionel Fourquaux; it has not been tested by me.
2407
2408 36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2409 used to name a group. Names consist of alphanumerics and underscores, and must
2410 be unique. Back references use the syntax (?P=name) and recursive calls use
2411 (?P>name) which is a PCRE extension to the Python extension. Groups still have
2412 numbers. The function pcre_fullinfo() can be used after compilation to extract
2413 a name/number map. There are three relevant calls:
2414
2415 PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2416 PCRE_INFO_NAMECOUNT yields the number of entries
2417 PCRE_INFO_NAMETABLE yields a pointer to the map.
2418
2419 The map is a vector of fixed-size entries. The size of each entry depends on
2420 the length of the longest name used. The first two bytes of each entry are the
2421 group number, most significant byte first. There follows the corresponding
2422 name, zero terminated. The names are in alphabetical order.
2423
2424 37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2425 case instead of 255. Making it the same both with and without UTF-8 support
2426 means that the same test output works with both.
2427
2428 38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2429 calling malloc() with a zero argument.
2430
2431 39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2432 optimization. I've improved things by keeping a bitmap of backreferences with
2433 numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2434 fact referenced, the optimization can be applied. It is unlikely that a
2435 relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2436 the match to follow \n) will appear inside brackets with a number greater than
2437 31, but if it does, any back reference > 31 suppresses the optimization.
2438
2439 40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2440 of disabling numbered capturing parentheses. Any opening parenthesis that is
2441 not followed by ? behaves as if it were followed by ?: but named parentheses
2442 can still be used for capturing (and they will acquire numbers in the usual
2443 way).
2444
2445 41. Redesigned the return codes from the match() function into yes/no/error so
2446 that errors can be passed back from deep inside the nested calls. A malloc
2447 failure while inside a recursive subpattern call now causes the
2448 PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2449
2450 42. It is now possible to set a limit on the number of times the match()
2451 function is called in a call to pcre_exec(). This facility makes it possible to
2452 limit the amount of recursion and backtracking, though not in a directly
2453 obvious way, because the match() function is used in a number of different
2454 circumstances. The count starts from zero for each position in the subject
2455 string (for non-anchored patterns). The default limit is, for compatibility, a
2456 large number, namely 10 000 000. You can change this in two ways:
2457
2458 (a) When configuring PCRE before making, you can use --with-match-limit=n
2459 to set a default value for the compiled library.
2460
2461 (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2462 a different value is set. See 45 below.
2463
2464 If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2465
2466 43. Added a new function pcre_config(int, void *) to enable run-time extraction
2467 of things that can be changed at compile time. The first argument specifies
2468 what is wanted and the second points to where the information is to be placed.
2469 The current list of available information is:
2470
2471 PCRE_CONFIG_UTF8
2472
2473 The output is an integer that is set to one if UTF-8 support is available;
2474 otherwise it is set to zero.
2475
2476 PCRE_CONFIG_NEWLINE
2477
2478 The output is an integer that it set to the value of the code that is used for
2479 newline. It is either LF (10) or CR (13).
2480
2481 PCRE_CONFIG_LINK_SIZE
2482
2483 The output is an integer that contains the number of bytes used for internal
2484 linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2485
2486 PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2487
2488 The output is an integer that contains the threshold above which the POSIX
2489 interface uses malloc() for output vectors. See item 31 above.
2490
2491 PCRE_CONFIG_MATCH_LIMIT
2492
2493 The output is an unsigned integer that contains the default limit of the number
2494 of match() calls in a pcre_exec() execution. See 42 above.
2495
2496 44. pcretest has been upgraded by the addition of the -C option. This causes it
2497 to extract all the available output from the new pcre_config() function, and to
2498 output it. The program then exits immediately.
2499
2500 45. A need has arisen to pass over additional data with calls to pcre_exec() in
2501 order to support additional features. One way would have been to define
2502 pcre_exec2() (for example) with extra arguments, but this would not have been
2503 extensible, and would also have required all calls to the original function to
2504 be mapped to the new one. Instead, I have chosen to extend the mechanism that
2505 is used for passing in "extra" data from pcre_study().
2506
2507 The pcre_extra structure is now exposed and defined in pcre.h. It currently
2508 contains the following fields:
2509
2510 flags a bitmap indicating which of the following fields are set
2511 study_data opaque data from pcre_study()
2512 match_limit a way of specifying a limit on match() calls for a specific
2513 call to pcre_exec()
2514 callout_data data for callouts (see 49 below)
2515
2516 The flag bits are also defined in pcre.h, and are
2517
2518 PCRE_EXTRA_STUDY_DATA
2519 PCRE_EXTRA_MATCH_LIMIT
2520 PCRE_EXTRA_CALLOUT_DATA
2521
2522 The pcre_study() function now returns one of these new pcre_extra blocks, with
2523 the actual study data pointed to by the study_data field, and the
2524 PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2525 before. That is, this change is entirely upwards-compatible and requires no
2526 change to existing code.
2527
2528 If you want to pass in additional data to pcre_exec(), you can either place it
2529 in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2530 block.
2531
2532 46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2533 data string contains the escape sequence \M, pcretest calls pcre_exec() several
2534 times with different match limits, until it finds the minimum value needed for
2535 pcre_exec() to complete. The value is then output. This can be instructive; for
2536 most simple matches the number is quite small, but for pathological cases it
2537 gets very large very quickly.
2538
2539 47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2540 returns the size of the data block pointed to by the study_data field in a
2541 pcre_extra block, that is, the value that was passed as the argument to
2542 pcre_malloc() when PCRE was getting memory in which to place the information
2543 created by pcre_study(). The fourth argument should point to a size_t variable.
2544 pcretest has been extended so that this information is shown after a successful
2545 pcre_study() call when information about the compiled regex is being displayed.
2546
2547 48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2548 because what follows is always an absolute path. (Later: it turns out that this
2549 is more than cosmetic for MinGW, because it doesn't like empty path
2550 components.)
2551
2552 49. Some changes have been made to the callout feature (see 28 above):
2553
2554 (i) A callout function now has three choices for what it returns:
2555
2556 0 => success, carry on matching
2557 > 0 => failure at this point, but backtrack if possible
2558 < 0 => serious error, return this value from pcre_exec()
2559
2560 Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2561 values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2562 "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2563 use by callout functions. It will never be used by PCRE itself.
2564
2565 (ii) The pcre_extra structure (see 45 above) has a void * field called
2566 callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2567 pcre_callout_block structure has a field of the same name. The contents of
2568 the field passed in the pcre_extra structure are passed to the callout
2569 function in the corresponding field in the callout block. This makes it
2570 easier to use the same callout-containing regex from multiple threads. For
2571 testing, the pcretest program has a new data escape
2572
2573 \C*n pass the number n (may be negative) as callout_data
2574
2575 If the callout function in pcretest receives a non-zero value as
2576 callout_data, it returns that value.
2577
2578 50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2579 there were some redundant $(CFLAGS) in commands that are now specified as
2580 $(LINK), which already includes $(CFLAGS).
2581
2582 51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2583 has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2584 with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2585 one-byte characters throughout. Note that case-insensitive matching applies
2586 only to characters whose values are less than 256. PCRE doesn't support the
2587 notion of cases for higher-valued characters.
2588
2589 (i) A character class whose characters are all within 0-255 is handled as
2590 a bit map, and the map is inverted for negative classes. Previously, a
2591 character > 255 always failed to match such a class; however it should
2592 match if the class was a negative one (e.g. [^ab]). This has been fixed.
2593
2594 (ii) A negated character class with a single character < 255 is coded as
2595 "not this character" (OP_NOT). This wasn't working properly when the test
2596 character was multibyte, either singly or repeated.
2597
2598 (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2599 mode, for example: \x{100}{2,3}.
2600
2601 (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2602 singly or repeated) now correctly test multibyte characters. However,
2603 PCRE doesn't recognize any characters with values greater than 255 as
2604 digits, spaces, or word characters. Such characters always match \D, \S,
2605 and \W, and never match \d, \s, or \w.
2606
2607 (v) Classes may now contain characters and character ranges with values
2608 greater than 255. For example: [ab\x{100}-\x{400}].
2609
2610 (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2611 PCRE in UTF-8 mode.
2612
2613 52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2614 PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2615 retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2616 value.)
2617
2618 53. The single man page has become too large. I have therefore split it up into
2619 a number of separate man pages. These also give rise to individual HTML pages;
2620 these are now put in a separate directory, and there is an index.html page that
2621 lists them all. Some hyperlinking between the pages has been installed.
2622
2623 54. Added convenience functions for handling named capturing parentheses.
2624
2625 55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2626 aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2627 true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2628 are faulted.
2629
2630 56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2631 calling configure. These values are used when compiling the dftables.c program
2632 which is run to generate the source of the default character tables. They
2633 default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2634 you will need to set these values.
2635
2636 57. Updated the building process for Windows DLL, as provided by Fred Cox.
2637
2638
2639 Version 3.9 02-Jan-02
2640 ---------------------
2641
2642 1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2643
2644 2. If --disable-static was given, the building process failed when trying to
2645 build pcretest and pcregrep. (For some reason it was using libtool to compile
2646 them, which is not right, as they aren't part of the library.)
2647
2648
2649 Version 3.8 18-Dec-01
2650 ---------------------
2651
2652 1. The experimental UTF-8 code was completely screwed up. It was packing the
2653 bytes in the wrong order. How dumb can you get?
2654
2655
2656 Version 3.7 29-Oct-01
2657 ---------------------
2658
2659 1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2660 This caused pcretest, when used on the test data, to segfault. Unfortunately,
2661 this didn't happen under Solaris 8, where I normally test things.
2662
2663 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2664 doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2665 isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2666 this fix an hour or so after the initial 3.7 release.)
2667
2668
2669 Version 3.6 23-Oct-01
2670 ---------------------
2671
2672 1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2673 offsets passed as NULL with zero offset count.
2674
2675 2. The config.guess and config.sub files had not been updated when I moved to
2676 the latest autoconf.
2677
2678
2679 Version 3.5 15-Aug-01
2680 ---------------------
2681
2682 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2683 had been forgotten.
2684
2685 2. By using declared but undefined structures, we can avoid using "void"
2686 definitions in pcre.h while keeping the internal definitions of the structures
2687 private.
2688
2689 3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2690 user point of view, this means that both static and shared libraries are built
2691 by default, but this can be individually controlled. More of the work of
2692 handling this static/shared cases is now inside libtool instead of PCRE's make
2693 file.
2694
2695 4. The pcretest utility is now installed along with pcregrep because it is
2696 useful for users (to test regexs) and by doing this, it automatically gets
2697 relinked by libtool. The documentation has been turned into a man page, so
2698 there are now .1, .txt, and .html versions in /doc.
2699
2700 5. Upgrades to pcregrep:
2701 (i) Added long-form option names like gnu grep.
2702 (ii) Added --help to list all options with an explanatory phrase.
2703 (iii) Added -r, --recursive to recurse into sub-directories.
2704 (iv) Added -f, --file to read patterns from a file.
2705
2706 6. pcre_exec() was referring to its "code" argument before testing that
2707 argument for NULL (and giving an error if it was NULL).
2708
2709 7. Upgraded Makefile.in to allow for compiling in a different directory from
2710 the source directory.
2711
2712 8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2713 options bits, the pointer it was passed was to an int instead of to an unsigned
2714 long int. This mattered only on 64-bit systems.
2715
2716 9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2717 generated) instead of pcre.in, which it its source. Also made the same change
2718 in several of the .c files.
2719
2720 10. A new release of gcc defines printf() as a macro, which broke pcretest
2721 because it had an ifdef in the middle of a string argument for printf(). Fixed
2722 by using separate calls to printf().
2723
2724 11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2725 script, to force use of CR or LF instead of \n in the source. On non-Unix
2726 systems, the value can be set in config.h.
2727
2728 12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2729 absolute limit. Changed the text of the error message to make this clear, and
2730 likewise updated the man page.
2731
2732 13. The limit of 99 on the number of capturing subpatterns has been removed.
2733 The new limit is 65535, which I hope will not be a "real" limit.
2734
2735
2736 Version 3.4 22-Aug-00
2737 ---------------------
2738
2739 1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2740
2741 2. Diagnose condition (?(0) as an error instead of crashing on matching.
2742
2743
2744 Version 3.3 01-Aug-00
2745 ---------------------
2746
2747 1. If an octal character was given, but the value was greater than \377, it
2748 was not getting masked to the least significant bits, as documented. This could
2749 lead to crashes in some systems.
2750
2751 2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2752 the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2753
2754 3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2755 These just pass their arguments on to (pcre_free)(), but they are provided
2756 because some uses of PCRE bind it to non-C systems that can call its functions,
2757 but cannot call free() or pcre_free() directly.
2758
2759 4. Add "make test" as a synonym for "make check". Corrected some comments in
2760 the Makefile.
2761
2762 5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2763 Makefile.
2764
2765 6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2766 command called pgrep for grepping around the active processes.
2767
2768 7. Added the beginnings of support for UTF-8 character strings.
2769
2770 8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2771 RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2772 the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2773 out for the ar command.)
2774
2775
2776 Version 3.2 12-May-00
2777 ---------------------
2778
2779 This is purely a bug fixing release.
2780
2781 1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2782 of ZA. This was just one example of several cases that could provoke this bug,
2783 which was introduced by change 9 of version 2.00. The code for breaking
2784 infinite loops after an iteration that matches an empty string was't working
2785 correctly.
2786
2787 2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2788 when matched against abbab (for example). After matching an empty string, it
2789 wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2790 caused it to match further down the string than it should.
2791
2792 3. The code contained an inclusion of sys/types.h. It isn't clear why this
2793 was there because it doesn't seem to be needed, and it causes trouble on some
2794 systems, as it is not a Standard C header. It has been removed.
2795
2796 4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2797 were reported on the Macintosh. The changes were from
2798
2799 while ((c = *(++ptr)) != 0 && c != '\n');
2800 to
2801 while ((c = *(++ptr)) != 0 && c != '\n') ;
2802
2803 Totally extraordinary, but if that's what it takes...
2804
2805 5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2806 available. Added HAVE_BCOPY and an autoconf test for it; if neither
2807 HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2808 assumes the way PCRE uses memmove() (always moving upwards).
2809
2810 6. PCRE is being used in one environment where strchr() is not available. There
2811 was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2812 faster code anyway.
2813
2814
2815 Version 3.1 09-Feb-00
2816 ---------------------
2817
2818 The only change in this release is the fixing of some bugs in Makefile.in for
2819 the "install" target:
2820
2821 (1) It was failing to install pcreposix.h.
2822
2823 (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2824
2825
2826 Version 3.0 01-Feb-00
2827 ---------------------
2828
2829 1. Add support for the /+ modifier to perltest (to output $` like it does in
2830 pcretest).
2831
2832 2. Add support for the /g modifier to perltest.
2833
2834 3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2835 matches null strings.
2836
2837 4. Fix perltest so that it doesn't do unwanted things when fed an empty
2838 pattern. Perl treats empty patterns specially - it reuses the most recent
2839 pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2840 effect.
2841
2842 5. The POSIX interface was broken in that it was just handing over the POSIX
2843 captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2844 required a bigger vector, with some working space on the end. This means that
2845 the POSIX wrapper now has to get and free some memory, and copy the results.
2846
2847 6. Added some simple autoconf support, placing the test data and the
2848 documentation in separate directories, re-organizing some of the
2849 information files, and making it build pcre-config (a GNU standard). Also added
2850 libtool support for building PCRE as a shared library, which is now the
2851 default.
2852
2853 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2854 09 are not valid octal constants. Single digits will be used for minor values
2855 less than 10.
2856
2857 8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2858 existing programs that set these in the POSIX interface can use PCRE without
2859 modification.
2860
2861 9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2862 return all that pcre_info() returns, plus additional data. The pcre_info()
2863 function is retained for compatibility, but is considered to be obsolete.
2864
2865 10. Added experimental recursion feature (?R) to handle one common case that
2866 Perl 5.6 will be able to do with (?p{...}).
2867
2868 11. Added support for POSIX character classes like [:alpha:], which Perl is
2869 adopting.
2870
2871
2872 Version 2.08 31-Aug-99
2873 ----------------------
2874
2875 1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2876 trying to match at the startoffset position, but instead was moving forward to
2877 the next newline as if a previous match had failed.
2878
2879 2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2880 and could get into a loop if a null string was matched other than at the start
2881 of the subject.
2882
2883 3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2884 be distinguished at compile time, and for completeness also added PCRE_DATE.
2885
2886 5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2887 in GnuWin32 environments.
2888
2889
2890 Version 2.07 29-Jul-99
2891 ----------------------
2892
2893 1. The documentation is now supplied in plain text form and HTML as well as in
2894 the form of man page sources.
2895
2896 2. C++ compilers don't like assigning (void *) values to other pointer types.
2897 In particular this affects malloc(). Although there is no problem in Standard
2898 C, I've put in casts to keep C++ compilers happy.
2899
2900 3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2901 should be (const char *).
2902
2903 4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2904 be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2905 However, I haven't made this a standard facility. The documentation doesn't
2906 mention it, and the Makefile doesn't support it.
2907
2908 5. The Makefile now contains an "install" target, with editable destinations at
2909 the top of the file. The pcretest program is not installed.
2910
2911 6. pgrep -V now gives the PCRE version number and date.
2912
2913 7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2914 causing the entire string to be ignored, instead of just the last character.
2915
2916 8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2917 non-matching string, it can take a very, very long time, even for strings of
2918 quite modest length, because of the nested recursion. PCRE now does better in
2919 some of these cases. It does this by remembering the last required literal
2920 character in the pattern, and pre-searching the subject to ensure it is present
2921 before running the real match. In other words, it applies a heuristic to detect
2922 some types of certain failure quickly, and in the above example, if presented
2923 with a string that has no trailing " it gives "no match" very quickly.
2924
2925 9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2926 other alternatives are tried instead.
2927
2928
2929 Version 2.06 09-Jun-99
2930 ----------------------
2931
2932 1. Change pcretest's output for amount of store used to show just the code
2933 space, because the remainder (the data block) varies in size between 32-bit and
2934 64-bit systems.
2935
2936 2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2937 start matching at. This allows lookbehinds to work when searching for multiple
2938 occurrences in a string.
2939
2940 3. Added additional options to pcretest for testing multiple occurrences:
2941
2942 /+ outputs the rest of the string that follows a match
2943 /g loops for multiple occurrences, using the new startoffset argument
2944 /G loops for multiple occurrences by passing an incremented pointer
2945
2946 4. PCRE wasn't doing the "first character" optimization for patterns starting
2947 with \b or \B, though it was doing it for other lookbehind assertions. That is,
2948 it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2949 the letter 'x'. On long subject strings, this gives a significant speed-up.
2950
2951
2952 Version 2.05 21-Apr-99
2953 ----------------------
2954
2955 1. Changed the type of magic_number from int to long int so that it works
2956 properly on 16-bit systems.
2957
2958 2. Fixed a bug which caused patterns starting with .* not to work correctly
2959 when the subject string contained newline characters. PCRE was assuming
2960 anchoring for such patterns in all cases, which is not correct because .* will
2961 not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2962 DOTALL is set at top level; otherwise it knows that patterns starting with .*
2963 must be retried after every newline in the subject.
2964
2965
2966 Version 2.04 18-Feb-99
2967 ----------------------
2968
2969 1. For parenthesized subpatterns with repeats whose minimum was zero, the
2970 computation of the store needed to hold the pattern was incorrect (too large).
2971 If such patterns were nested a few deep, this could multiply and become a real
2972 problem.
2973
2974 2. Added /M option to pcretest to show the memory requirement of a specific
2975 pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2976
2977 3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2978 compiled in such a way that the backtracking after subsequent failure was
2979 pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2980 ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2981
2982
2983 Version 2.03 02-Feb-99
2984 ----------------------
2985
2986 1. Fixed typo and small mistake in man page.
2987
2988 2. Added 4th condition (GPL supersedes if conflict) and created separate
2989 LICENCE file containing the conditions.
2990
2991 3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2992 Perl, that is the internal \ allows the delimiter to be included in the
2993 pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2994 the final delimiter, add \ to the end of the pattern (to test the error).
2995
2996 4. Added the convenience functions for extracting substrings after a successful
2997 match. Updated pcretest to make it able to test these functions.
2998
2999
3000 Version 2.02 14-Jan-99
3001 ----------------------
3002
3003 1. Initialized the working variables associated with each extraction so that
3004 their saving and restoring doesn't refer to uninitialized store.
3005
3006 2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3007 compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3008 fix the problem.
3009
3010 3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3011 calls, and wasn't printing the correct value for compiling calls. Increased the
3012 default value of LOOPREPEAT, and the number of significant figures in the
3013 times.
3014
3015 4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3016
3017 5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3018 a building problem on Windows NT with a FAT file system.
3019
3020
3021 Version 2.01 21-Oct-98
3022 ----------------------
3023
3024 1. Changed the API for pcre_compile() to allow for the provision of a pointer
3025 to character tables built by pcre_maketables() in the current locale. If NULL
3026 is passed, the default tables are used.
3027
3028
3029 Version 2.00 24-Sep-98
3030 ----------------------
3031
3032 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3033 it any more.
3034
3035 2. Allow quantification of (?>) groups, and make it work correctly.
3036
3037 3. The first character computation wasn't working for (?>) groups.
3038
3039 4. Correct the implementation of \Z (it is permitted to match on the \n at the
3040 end of the subject) and add 5.005's \z, which really does match only at the
3041 very end of the subject.
3042
3043 5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3044
3045 6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3046 DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3047 localized options. All options to pcre_study() were also removed.
3048
3049 7. Add other new features from 5.005:
3050
3051 $(?<= positive lookbehind
3052 $(?<! negative lookbehind
3053 (?imsx-imsx) added the unsetting capability
3054 such a setting is global if at outer level; local otherwise
3055 (?imsx-imsx:) non-capturing groups with option setting
3056 (?(cond)re|re) conditional pattern matching
3057
3058 A backreference to itself in a repeated group matches the previous
3059 captured string.
3060
3061 8. General tidying up of studying (both automatic and via "study")
3062 consequential on the addition of new assertions.
3063
3064 9. As in 5.005, unlimited repeated groups that could match an empty substring
3065 are no longer faulted at compile time. Instead, the loop is forcibly broken at
3066 runtime if any iteration does actually match an empty substring.
3067
3068 10. Include the RunTest script in the distribution.
3069
3070 11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3071 discrepancies, some of which were old and were also with respect to 5.004. They
3072 have now been fixed.
3073
3074
3075 Version 1.09 28-Apr-98
3076 ----------------------
3077
3078 1. A negated single character class followed by a quantifier with a minimum
3079 value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3080 program crashes, or just wrong answers. This did not apply to negated classes
3081 containing more than one character, or to minima other than one.
3082
3083
3084 Version 1.08 27-Mar-98
3085 ----------------------
3086
3087 1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3088
3089 2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3090 latter must appear before anything that relies on it in the pattern.
3091
3092
3093 Version 1.07 16-Feb-98
3094 ----------------------
3095
3096 1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3097 repeat of a potentially empty string).
3098
3099
3100 Version 1.06 23-Jan-98
3101 ----------------------
3102
3103 1. Added Markus Oberhumer's little patches for C++.
3104
3105 2. Literal strings longer than 255 characters were broken.
3106
3107
3108 Version 1.05 23-Dec-97
3109 ----------------------
3110
3111 1. Negated character classes containing more than one character were failing if
3112 PCRE_CASELESS was set at run time.
3113
3114
3115 Version 1.04 19-Dec-97
3116 ----------------------
3117
3118 1. Corrected the man page, where some "const" qualifiers had been omitted.
3119
3120 2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3121 input syntax.
3122
3123 3. Fixed memory leak which occurred when a regex with back references was
3124 matched with an offsets vector that wasn't big enough. The temporary memory
3125 that is used in this case wasn't being freed if the match failed.
3126
3127 4. Tidied pcretest to ensure it frees memory that it gets.
3128
3129 5. Temporary memory was being obtained in the case where the passed offsets
3130 vector was exactly big enough.
3131
3132 6. Corrected definition of offsetof() from change 5 below.
3133
3134 7. I had screwed up change 6 below and broken the rules for the use of
3135 setjmp(). Now fixed.
3136
3137
3138 Version 1.03 18-Dec-97
3139 ----------------------
3140
3141 1. A erroneous regex with a missing opening parenthesis was correctly
3142 diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3143 on some systems.
3144
3145 2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3146 it was reported that one broken compiler failed on the former because "code" is
3147 also an independent variable.
3148
3149 3. The erroneous regex a[]b caused an array overrun reference.
3150
3151 4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3152 fail on data ending with that character. (It was going on too far, and checking
3153 the next character, typically a binary zero.) This was specific to the
3154 optimized code for single-character negative classes.
3155
3156 5. Added a contributed patch from the TIN world which does the following:
3157
3158 + Add an undef for memmove, in case the the system defines a macro for it.
3159
3160 + Add a definition of offsetof(), in case there isn't one. (I don't know
3161 the reason behind this - offsetof() is part of the ANSI standard - but
3162 it does no harm).
3163
3164 + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3165 most of the places where whitespace preceded '#'. I have given up and
3166 allowed the remaining 2 cases to be at the margin.
3167
3168 + Rename some variables in pcre to eliminate shadowing. This seems very
3169 pedantic, but does no harm, of course.
3170
3171 6. Moved the call to setjmp() into its own function, to get rid of warnings
3172 from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3173
3174 7. Constructs such as \d{8,} were compiling into the equivalent of
3175 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3176 outcome, but in this particular case used more store than had been allocated,
3177 which caused the bug to be discovered because it threw up an internal error.
3178
3179 8. The debugging code in both pcre and pcretest for outputting the compiled
3180 form of a regex was going wrong in the case of back references followed by
3181 curly-bracketed repeats.
3182
3183
3184 Version 1.02 12-Dec-97
3185 ----------------------
3186
3187 1. Typos in pcre.3 and comments in the source fixed.
3188
3189 2. Applied a contributed patch to get rid of places where it used to remove
3190 'const' from variables, and fixed some signed/unsigned and uninitialized
3191 variable warnings.
3192
3193 3. Added the "runtest" target to Makefile.
3194
3195 4. Set default compiler flag to -O2 rather than just -O.
3196
3197
3198 Version 1.01 19-Nov-97
3199 ----------------------
3200
3201 1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3202 like /([ab]*)*/, that is, for classes with more than one character in them.
3203
3204 2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3205 as /((?>a*))*/ (a PCRE_EXTRA facility).
3206
3207
3208 Version 1.00 18-Nov-97
3209 ----------------------
3210
3211 1. Added compile-time macros to support systems such as SunOS4 which don't have
3212 memmove() or strerror() but have other things that can be used instead.
3213
3214 2. Arranged that "make clean" removes the executables.
3215
3216
3217 Version 0.99 27-Oct-97
3218 ----------------------
3219
3220 1. Fixed bug in code for optimizing classes with only one character. It was
3221 initializing a 32-byte map regardless, which could cause it to run off the end
3222 of the memory it had got.
3223
3224 2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3225
3226
3227 Version 0.98 22-Oct-97
3228 ----------------------
3229
3230 1. Fixed bug in code for handling temporary memory usage when there are more
3231 back references than supplied space in the ovector. This could cause segfaults.
3232
3233
3234 Version 0.97 21-Oct-97
3235 ----------------------
3236
3237 1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3238
3239 2. Optimized negated single characters not to use a bit map.
3240
3241 3. Brought error texts together as macro definitions; clarified some of them;
3242 fixed one that was wrong - it said "range out of order" when it meant "invalid
3243 escape sequence".
3244
3245 4. Changed some char * arguments to const char *.
3246
3247 5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3248
3249 6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3250 pcretest.
3251
3252
3253 Version 0.96 16-Oct-97
3254 ----------------------
3255
3256 1. Added a simple "pgrep" utility to the distribution.
3257
3258 2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3259 unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3260 where "ddd" means "one or more decimal digits".
3261
3262 3. Fixed serious bug. If a pattern had a back reference, but the call to
3263 pcre_exec() didn't supply a large enough ovector to record the related
3264 identifying subpattern, the match always failed. PCRE now remembers the number
3265 of the largest back reference, and gets some temporary memory in which to save
3266 the offsets during matching if necessary, in order to ensure that
3267 backreferences always work.
3268
3269 4. Increased the compatibility with Perl in a number of ways:
3270
3271 (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3272 to request this handling. The option can be set at compile or exec time.
3273
3274 (b) $ matches before a terminating newline by default; an option
3275 PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3276 mode). The option can be set at compile or exec time.
3277
3278 (c) The handling of \ followed by a digit other than 0 is now supposed to be
3279 the same as Perl's. If the decimal number it represents is less than 10
3280 or there aren't that many previous left capturing parentheses, an octal
3281 escape is read. Inside a character class, it's always an octal escape,
3282 even if it is a single digit.
3283
3284 (d) An escaped but undefined alphabetic character is taken as a literal,
3285 unless PCRE_EXTRA is set. Currently this just reserves the remaining
3286 escapes.
3287
3288 (e) {0} is now permitted. (The previous item is removed from the compiled
3289 pattern).
3290
3291 5. Changed all the names of code files so that the basic parts are no longer
3292 than 10 characters, and abolished the teeny "globals.c" file.
3293
3294 6. Changed the handling of character classes; they are now done with a 32-byte
3295 bit map always.
3296
3297 7. Added the -d and /D options to pcretest to make it possible to look at the
3298 internals of compilation without having to recompile pcre.
3299
3300
3301 Version 0.95 23-Sep-97
3302 ----------------------
3303
3304 1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3305 \x20 at the start of a run of normal characters. These were being treated as
3306 real characters, instead of the source characters being re-checked.
3307
3308
3309 Version 0.94 18-Sep-97
3310 ----------------------
3311
3312 1. The functions are now thread-safe, with the caveat that the global variables
3313 containing pointers to malloc() and free() or alternative functions are the
3314 same for all threads.
3315
3316 2. Get pcre_study() to generate a bitmap of initial characters for non-
3317 anchored patterns when this is possible, and use it if passed to pcre_exec().
3318
3319
3320 Version 0.93 15-Sep-97
3321 ----------------------
3322
3323 1. /(b)|(:+)/ was computing an incorrect first character.
3324
3325 2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3326 but not actually doing anything yet.
3327
3328 3. Treat "-" characters in classes that cannot be part of ranges as literals,
3329 as Perl does (e.g. [-az] or [az-]).
3330
3331 4. Set the anchored flag if a branch starts with .* or .*? because that tests
3332 all possible positions.
3333
3334 5. Split up into different modules to avoid including unneeded functions in a
3335 compiled binary. However, compile and exec are still in one module. The "study"
3336 function is split off.
3337
3338 6. The character tables are now in a separate module whose source is generated
3339 by an auxiliary program - but can then be edited by hand if required. There are
3340 now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3341 toupper() in the code.
3342
3343 7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3344 make them global. Abolish the function for setting them, as the caller can now
3345 set them directly.
3346
3347
3348 Version 0.92 11-Sep-97
3349 ----------------------
3350
3351 1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3352 (e.g. /a{1,3}/) was broken (I mis-optimized it).
3353
3354 2. Caseless matching was not working in character classes if the characters in
3355 the pattern were in upper case.
3356
3357 3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3358
3359 4. Make PCRE_ANCHORED public and accept as a compile option.
3360
3361 5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3362 PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3363 pass them.
3364
3365 6. Give an error if bad option bits passed at compile or run time.
3366
3367 7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3368 pcretest to cause it to pass that flag.
3369
3370 8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3371 options, and the first character, if set.
3372
3373 9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3374
3375
3376 Version 0.91 10-Sep-97
3377 ----------------------
3378
3379 1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3380 match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3381
3382 2. PCRE was looping on encountering an indefinitely repeated back reference to
3383 a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3384 Perl does - treats the match as successful.
3385
3386 ****

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