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Revision 420 - (hide annotations) (download)
Wed Aug 12 17:32:27 2009 UTC (5 years, 8 months ago) by ph10
File size: 166599 byte(s)
Fix infelicities to do with --count in pcregrep.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 418 Version 8.00 ??-???-??
5     ----------------------
7     1. The table for translating pcre_compile() error codes into POSIX error codes
8     was out-of-date, and there was no check on the pcre_compile() error code
9     being within the table. This could lead to an OK return being given in
10     error.
11 ph10 419
12     2. Changed the call to open a subject file in pcregrep from fopen(pathname,
13     "r") to fopen(pathname, "rb"), which fixed a problem with some of the tests
14     in a Windows environment.
15 ph10 420
16     3. The pcregrep --count option prints the count for each file even when it is
17     zero, as does GNU grep. However, pcregrep was also printing all files when
18     --files-with-matches was added. Now, when both options are given, it prints
19     counts only for those files that have at least one match. (GNU grep just
20     prints the file name in this circumstance, but including the count seems
21     more useful - otherwise, why use --count?) Also ensured that the
22     combination -clh just lists non-zero counts, with no names.
24 ph10 418
25 ph10 412 Version 7.9 11-Apr-09
26 ph10 376 ---------------------
28 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
29 ph10 376 (pcretest), all targets were linked against these libraries. This included
30     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
31     libraries. This caused unwanted dependencies to be created. This problem
32 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
33 ph10 376 pcretest is linked with readline.
34 ph10 392
35 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
36     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
37     moved outside it again, because FALSE and TRUE are already defined in AIX,
38     but BOOL is not.
39 ph10 392
40     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
41 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
42 ph10 392
43 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
44     hyphens) following file names and line numbers when outputting matching
45 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
46 ph10 376 wording for the --colour (or --color) option.
47 ph10 392
48 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
49     was not coloured; this is different to GNU grep, so I have changed it to be
50     the same.
51 ph10 392
52 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
53 ph10 392 each matching line was coloured. Now it goes on to look for further matches
54     of any of the test patterns, which is the same behaviour as GNU grep.
56     7. A pattern that could match an empty string could cause pcregrep to loop; it
57     doesn't make sense to accept an empty string match in pcregrep, so I have
58 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
59     seems to be how GNU grep behaves.
60 ph10 392
61 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
62 ph10 392 start or after a newline", because the conditional assertion was not being
63     correctly handled. The rule now is that both the assertion and what follows
64     in the first alternative must satisfy the test.
66 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
67 ph10 399 condition was an assertion, PCRE could crash during matching, both with
68     pcre_exec() and pcre_dfa_exec().
69 ph10 392
70     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
71     used for matching.
73     11. Unicode property support in character classes was not working for
74 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
75 ph10 388
76 ph10 392 12. Added the -M command line option to pcretest.
78 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
79 ph10 389
80     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
81 ph10 390
82 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
83 ph10 390 wrapper.
84 ph10 392
85 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
86 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
87 ph10 391 string constants.
88 ph10 405
89 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
90     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
91 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
92     these, but not everybody uses configure.
94     19. A conditional group that had only one branch was not being correctly
95     recognized as an item that could match an empty string. This meant that an
96     enclosing group might also not be so recognized, causing infinite looping
97     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
98     with the subject "ab", where knowledge that the repeated group can match
99 ph10 396 nothing is needed in order to break the loop.
100 ph10 405
101 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
102 ph10 405 exec(), but without supplying a callout function, matching went wrong.
104     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
105     leak if the size of the offset vector was greater than 30. When the vector
106     is smaller, the saved offsets during recursion go onto a local stack
107     vector, but for larger vectors malloc() is used. It was failing to free
108     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
109 ph10 400 error, in fact).
110 ph10 405
111 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
112 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
113     problem, but was untidy.
114 ph10 376
115 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
116     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
117     included within another project.
118 ph10 411
119 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
120     slightly modified by me:
121 ph10 411
122     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
123     not building pcregrep.
125 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
126 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
128 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
129     duplicate group numbers, could behave incorrectly or give incorrect errors,
130     because when scanning forward to find the reference group, PCRE was not
131     taking into account the duplicate group numbers. A pattern such as
132     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
133 ph10 411
134     26. Changed a few more instances of "const unsigned char *" to USPTR, making
135     the feature of a custom pointer more persuasive (as requested by a user).
136 ph10 416
137 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
138 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
139     pre-defined.
140 ph10 392
141 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
143 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
144     in the configuration summary.
145 ph10 405
146 ph10 411
147 ph10 374 Version 7.8 05-Sep-08
148 ph10 349 ---------------------
150     1. Replaced UCP searching code with optimized version as implemented for Ad
151     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
152 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
153     to 5 times on some simple patterns that I tested. Permission was given to
154     distribute the MultiStage2.py script that generates the tables (it's not in
155     the tarball, but is in the Subversion repository).
156 ph10 349
157 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
158     scripts.
159 ph10 358
160 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
161     a group with a zero qualifier. The result of the study could be incorrect,
162 ph10 358 or the function might crash, depending on the pattern.
164     4. Caseless matching was not working for non-ASCII characters in back
165 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
166 ph10 358 It now works when Unicode Property Support is available.
168 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
169     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
170     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
171 ph10 358 truncation.
172 ph10 349
173 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
175 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
176     pointers, in case they are 64-bit values.
177 ph10 371
178     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
179     test 2 if it fails.
181 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
182 ph10 371 and a #define of that name to empty if it is not externally set. This is to
183     allow users of MSVC to set it if necessary.
185     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
186 ph10 359 the convenience functions in the pcre_get.c source file.
187 ph10 371
188 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
189     could cause overwriting and/or a crash. This command provoked a crash in
190 ph10 371 some environments:
192     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
194 ph10 360 This potential security problem was recorded as CVE-2008-2371.
195 ph10 371
196 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
197     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
198 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
199 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
200     pcretest so that it places the subject at the end of its malloc-ed buffer.
201 ph10 371
202 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
203 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
205 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
206 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
207     first line. This applied both to normal and DFA matching.
209 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
210 ph10 371 /^[^d]*?$/8 failed to match "abc".
211 ph10 351
212 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
214     17. Make it more clear in the documentation that values returned from
215 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
216 ph10 357
217 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
218 ph10 368
219 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
220     supplied by Stefan Weber. I made a further small update for 7.8 because
221 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
222     replaced by pcre_ucd.c.
223 ph10 371
224 ph10 373
225 ph10 347 Version 7.7 07-May-08
226 ph10 321 ---------------------
228     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
229 ph10 345 a string to a long long, pretend we don't even have a long long." This is
230 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
231 ph10 345
232 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
233     pre-7.6 versions, which defined a global no_arg variable instead of putting
234 ph10 332 it in the RE class. (See also #8 below.)
235 ph10 345
236     3. Remove a line of dead code, identified by coverity and reported by Nuno
237     Lopes.
239 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
240 ph10 321
241 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
242 ph10 345 of files, instead of just to the final components.
244 ph10 324 (2) If there was more than one level of directory, the subdirectories were
245     skipped unless they satisfied the include/exclude conditions. This is
246     inconsistent with GNU grep (and could even be seen as contrary to the
247     pcregrep specification - which I improved to make it absolutely clear).
248     The action now is always to scan all levels of directory, and just
249     apply the include/exclude patterns to regular files.
250 ph10 345
251 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
252 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
254 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
255 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
256 ph10 326 doesn't support NULs in patterns.
257 ph10 345
258     7. Added some missing "const"s to declarations of static tables in
259     pcre_compile.c and pcre_dfa_exec.c.
261 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
262 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
263 ph10 345 first patch. And a third patch - this was a messy problem.)
264 ph10 321
265 ph10 345 9. Applied Craig's patch to remove the use of push_back().
267 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
268     matching function regexec().
269 ph10 345
270     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
271     which, however, unlike Perl's \g{...}, are subroutine calls, not back
272 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
273     Oniguruma does).
274 ph10 345
275     12. Previously, a group with a zero repeat such as (...){0} was completely
276 ph10 335 omitted from the compiled regex. However, this means that if the group
277     was called as a subroutine from elsewhere in the pattern, things went wrong
278 ph10 345 (an internal error was given). Such groups are now left in the compiled
279     pattern, with a new opcode that causes them to be skipped at execution
280 ph10 335 time.
281 ph10 345
282 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
283     to the way PCRE behaves:
284 ph10 345
285 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
286 ph10 345
287     (b) A back reference to an unmatched subpattern matches an empty string
288 ph10 336 (Perl fails the current match path).
289 ph10 345
290 ph10 341 (c) A data ] in a character class must be notated as \] because if the
291 ph10 345 first data character in a class is ], it defines an empty class. (In
292 ph10 341 Perl it is not possible to have an empty class.) The empty class []
293     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
294     The negative empty class [^] matches any one character, independently
295     of the DOTALL setting.
296 ph10 345
297     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
298 ph10 340 non-existent subpattern following a character class starting with ']' and
299     containing () gave an internal compiling error instead of "reference to
300     non-existent subpattern". Fortunately, when the pattern did exist, the
301 ph10 345 compiled code was correct. (When scanning forwards to check for the
302 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
303 ph10 345 the class, so got the count wrong. When actually compiling, the reference
304 ph10 340 was subsequently set up correctly.)
305 ph10 345
306 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
307 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
308     other assertions are supported. I have made pcre_dfa_exec() support
309     (*FAIL).
311 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
312 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
313     cannot be changed at match time, I realized I could make a small
314     improvement to matching performance by compiling OP_ALLANY instead of
315     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
316     on the OP_ANY path.
318     17. Compiling pcretest on Windows with readline support failed without the
319 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
320 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
322 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
323 ph10 345 ncurses library to be included for pcretest when ReadLine support is
324     requested, but also to allow for it to be overridden. This patch came from
325     Daniel Bergström.
326 ph10 347
327 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
328 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
329     any errors with the current Unicode tables. Thanks to Peter Kankowski for
330     spotting this.
331 ph10 324
332 ph10 332
333 ph10 319 Version 7.6 28-Jan-08
334 ph10 300 ---------------------
336 ph10 302 1. A character class containing a very large number of characters with
337     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
338     overflow.
339 ph10 309
340     2. Patch to cut out the "long long" test in pcrecpp_unittest when
341     HAVE_LONG_LONG is not defined.
343 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
344 ph10 304 bring them up to date and include new features. This patch includes:
345 ph10 309
346 ph10 304 - Fixed PH's badly added libz and libbz2 support.
347     - Fixed a problem with static linking.
348 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
349 ph10 304 - Fixed dftables problem and added an option.
350     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
352     - Added readline support for pcretest.
353 ph10 309 - Added an listing of the option settings after cmake has run.
355 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
356     "pcre.dll" under mingw when using Configure/Make. I added stuff to
357     Makefile.am that cause it to include this special target, without
358     affecting anything else. Note that the same mingw target plus all
359     the other distribution libraries and programs are now supported
360     when configuring with CMake (see 6 below) instead of with
361     Configure/Make.
362 ph10 309
363 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
364     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
365 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
366     solves the problem, but it does no harm.
367 ph10 313
368 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
369 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
370 ph10 314 with CMake, and also correct the comment about stack recursion.
371 ph10 313
372 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
373 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
374     of a program that users should build themselves after PCRE is installed, so
375     building it automatically is not really right. What is more, it gave
376 ph10 312 trouble in some build environments.
377 ph10 300
378 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
379 ph10 308
380 ph10 319
381 ph10 298 Version 7.5 10-Jan-08
382 ph10 263 ---------------------
384     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
385     values in parens when parsing an RE using the C++ wrapper."
386 ph10 286
387 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
388     Characters greater than 255 were excluded from the class instead of being
389     included.
390 ph10 286
391     3. The same bug as (2) above applied to negated POSIX classes such as
392 ph10 265 [:^space:].
393 ph10 286
394 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
395     defined or documented. It seems to have been a typo for PCRE_STATIC, so
396 ph10 286 I have changed it.
398 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
399 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
400     first named subpattern whose name started with "a" (in other words, the
401 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
402     expected" is now given for (?&) (a zero-length name), and this patch also
403     makes it give the same error for \k'' (previously it complained that that
404     was a reference to a non-existent subpattern).
405 ph10 286
406 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
407 ph10 286 this is right because (?- can be followed by option settings as well as by
408 ph10 269 digits. I have, however, made the messages clearer.
409 ph10 286
410 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
411     than the number used in the conditional) now cause a compile-time error.
412     This is actually not compatible with Perl, which accepts such patterns, but
413     treats the conditional as always being FALSE (as PCRE used to), but it
414     seems to me that giving a diagnostic is better.
415 ph10 286
416 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
417 ph10 275 and messages.
418 ph10 286
419     9. Fix two occurrences of "backslash" in comments that should have been
420     "backspace".
422     10. Remove two redundant lines of code that can never be obeyed (their function
423     was moved elsewhere).
425     11. The program that makes PCRE's Unicode character property table had a bug
426     which caused it to generate incorrect table entries for sequences of
427 ph10 277 characters that have the same character type, but are in different scripts.
428 ph10 286 It amalgamated them into a single range, with the script of the first of
429 ph10 277 them. In other words, some characters were in the wrong script. There were
430     thirteen such cases, affecting characters in the following ranges:
431 ph10 286
432 ph10 277 U+002b0 - U+002c1
433     U+0060c - U+0060d
434 ph10 286 U+0061e - U+00612
435 ph10 277 U+0064b - U+0065e
436     U+0074d - U+0076d
437     U+01800 - U+01805
438     U+01d00 - U+01d77
439     U+01d9b - U+01dbf
440     U+0200b - U+0200f
441     U+030fc - U+030fe
442     U+03260 - U+0327f
443     U+0fb46 - U+0fbb1
444     U+10450 - U+1049d
445 ph10 286
446 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
447     compatible with GNU grep in that, if there was more than one match in a
448     line, it showed only the first of them. It now behaves in the same way as
449     GNU grep.
450 ph10 286
451     13. If the -o and -v options were combined for pcregrep, it printed a blank
452     line for every non-matching line. GNU grep prints nothing, and pcregrep now
453     does the same. The return code can be used to tell if there were any
454     non-matching lines.
456 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
458     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
459 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
460 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
461     and both kinds of lookbehind were skipped).
463 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
464 ph10 284 inclusion of <windows.h> to before rather than after the definition of
465     INVALID_FILE_ATTRIBUTES (patch from David Byron).
466 ph10 263
467 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
468 ph10 286 character property caused pcre_compile() to compile bad code, which led at
469     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
470     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
471     caused the error; without that there was no problem.
472 ph10 263
473 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
474 ph10 286
475 ph10 289 19. Added --enable-pcretest-libreadline.
476 ph10 286
477 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
478 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
479 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
480     later patch that removed the other one (the right fix) and added unit tests
481     that check the return values (which was not done before).
482 ph10 292
483 ph10 291 21. Several CMake things:
484 ph10 287
485 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
486 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
487 ph10 288
488 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
489     linked with the newly-built libraries, not previously installed ones.
490 ph10 291
492 ph10 298
493     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
494     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
495     UTF-8 newline character). The key issue is that the pattern starts .*;
496     this means that the match must be either at the beginning, or after a
497     newline. The bug was in the code for advancing after a failed match and
498     checking that the new position followed a newline. It was not taking
499 ph10 294 account of UTF-8 characters correctly.
500 ph10 298
501     23. PCRE was behaving differently from Perl in the way it recognized POSIX
502     character classes. PCRE was not treating the sequence [:...:] as a
503     character class unless the ... were all letters. Perl, however, seems to
504     allow any characters between [: and :], though of course it rejects as
505     unknown any "names" that contain non-letters, because all the known class
506     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
507     for example, whereas PCRE did not - it did not recognize a POSIX character
508     class. This seemed a bit dangerous, so the code has been changed to be
509     closer to Perl. The behaviour is not identical to Perl, because PCRE will
510     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
511     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
512     Perl does, and where it didn't before.
514 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
515     Windows environments %n is disabled by default.
516 ph10 292
518 ph10 260 Version 7.4 21-Sep-07
519 ph10 230 ---------------------
521     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
522 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
523     LF". That isn't really right - the whole point of the change was to try to
524     help when there was an actual mention of one of the two characters. So now
525     the change happens only if \r or \n (or a literal CR or LF) character is
526 ph10 230 encountered.
527 ph10 231
528     2. The 32-bit options word was also used for 6 internal flags, but the numbers
529     of both had grown to the point where there were only 3 bits left.
530     Fortunately, there was spare space in the data structure, and so I have
531     moved the internal flags into a new 16-bit field to free up more option
532 ph10 230 bits.
533 ph10 231
534     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
535     but did not set the internal JCHANGED flag - either of these is enough to
536     control the way the "get" function works - but the PCRE_INFO_JCHANGED
537     facility is supposed to tell if (?J) was ever used, so now (?J) at the
538 ph10 230 start sets both bits.
540 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
541     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
542 ph10 230
543 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
545     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
546 ph10 233 compatibility, even though it is no longer used.
547 ph10 243
548     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
549 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
550 ph10 259 windows.h file is present (where different names are used). [This was
551 ph10 257 reversed later after testing - see 16 below.]
552 ph10 243
553     8. Changed all #include <config.h> to #include "config.h". There were also
554 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
555 ph10 243
556 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
557 ph10 243 sequence off the lines that it output.
559     10. It was pointed out to me that arrays of string pointers cause lots of
560     relocations when a shared library is dynamically loaded. A technique of
561     using a single long string with a table of offsets can drastically reduce
562     these. I have refactored PCRE in four places to do this. The result is
563 ph10 240 dramatic:
564 ph10 243
565 ph10 240 Originally: 290
566     After changing UCP table: 187
567 ph10 243 After changing error message table: 43
568 ph10 240 After changing table of "verbs" 36
569     After changing table of Posix names 22
570 ph10 243
571 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
572 ph10 247
573 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
574 ph10 247 unicode-properties was also set.
576 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
577 ph10 231
578 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
579     checked only for CRLF.
580 ph10 233
581 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
583 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
584 ph10 253
585 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
586 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
587     entirely. This removes changes made in 7 above.
588 ph10 256
589 ph10 261 17. The CMake files have been updated, and there is now more information about
590     building with CMake in the NON-UNIX-USE document.
591 ph10 257
592 ph10 261
593 ph10 228 Version 7.3 28-Aug-07
594 ph10 157 ---------------------
596 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
597     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
598     brackets there is not right, since it causes compilers to look for an
599     installed pcre.h, not the version that is in the source that is being
600     compiled (which of course may be different). I have changed it back to:
601 ph10 197
602 ph10 189 #include "pcre.h"
603 ph10 197
604     I have a vague recollection that the change was concerned with compiling in
605     different directories, but in the new build system, that is taken care of
606     by the VPATH setting the Makefile.
608 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
609     when the subject happened to end in the byte 0x85 (e.g. if the last
610     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
611     characters but of course it shouldn't be taken as a newline when it is part
612     of another character. The bug was that, for an unlimited repeat of . in
613     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
614     characters when looking for a newline.
615 ph10 197
616     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
618     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
619     in debug output.
621 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
622     long printing in the pcrecpp unittest when running under MinGW.
623 ph10 189
624 ph10 197 6. ESC_K was left out of the EBCDIC table.
625 ph10 189
626 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
627     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
628     limit also applies to "virtual nesting" when a pattern is recursive, and in
629     this case 1000 isn't so big. I have been able to remove this limit at the
630     expense of backing off one optimization in certain circumstances. Normally,
631     when pcre_exec() would call its internal match() function recursively and
632     immediately return the result unconditionally, it uses a "tail recursion"
633     feature to save stack. However, when a subpattern that can match an empty
634     string has an unlimited repetition quantifier, it no longer makes this
635     optimization. That gives it a stack frame in which to save the data for
636     checking that an empty string has been matched. Previously this was taken
637     from the 1000-entry workspace that had been reserved. So now there is no
638     explicit limit, but more stack is used.
639 ph10 189
640 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
641     syntax that is required for Windows, and which was going wrong for the
642     pcreposix and pcrecpp parts of the library. These were overlooked when this
643     problem was solved for the main library.
644 ph10 197
645 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
646     the size of patterns that contain repeated groups with explicit upper
647     limits. As the maximum quantifier is 65535, the maximum group length was
648     set at 30,000 so that the product of these two numbers did not overflow a
649     32-bit integer. However, it turns out that people want to use groups that
650     are longer than 30,000 bytes (though not repeat them that many times).
651     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
652     made it possible to implement the integer overflow checks in a much more
653     dynamic way, which I have now done. The artificial limitation on group
654     length has been removed - we now have only the limit on the total length of
655     the compiled pattern, which depends on the LINK_SIZE setting.
656 ph10 208
657     10. Fixed a bug in the documentation for get/copy named substring when
658     duplicate names are permitted. If none of the named substrings are set, the
659     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
660     empty string.
662     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
663     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
664     because the ] is interpreted as the first data character and the
665     terminating ] is not found. PCRE has been made compatible with Perl in this
666     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
667     cause memory overwriting.
669 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
670     string has been matched (to stop an infinite loop). It was not recognizing
671 ph10 208 a conditional subpattern that could match an empty string if that
672 ph10 206 subpattern was within another subpattern. For example, it looped when
673 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
674 ph10 206 condition was not nested. This bug has been fixed.
675 ph10 208
676 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
677     past the start of the subject in the presence of bytes with the top bit
678     set, for example "\x8aBCD".
679 ph10 211
680 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
681     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
682 ph10 200
683 ph10 211 14. Optimized (?!) to (*FAIL).
684 ph10 202
685 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
686     This restricts code points to be within the range 0 to 0x10FFFF, excluding
687     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
688     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
689     does: it's just the validity check that is more restrictive.
690 ph10 220
691     16. Inserted checks for integer overflows during escape sequence (backslash)
692     processing, and also fixed erroneous offset values for syntax errors during
693     backslash processing.
695 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
696 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
698 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
699     caused an overrun.
700 ph10 220
701     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
702     something other than just ASCII characters) inside a group that had an
703     unlimited repeat caused a loop at compile time (while checking to see
704     whether the group could match an empty string).
706 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
707     [\P{Any}] did so. (Error in the code for printing property names.)
708 ph10 210
709 ph10 220 21. An orphan \E inside a character class could cause a crash.
711     22. A repeated capturing bracket such as (A)? could cause a wild memory
712 ph10 218 reference during compilation.
713 ph10 220
714     23. There are several functions in pcre_compile() that scan along a compiled
715     expression for various reasons (e.g. to see if it's fixed length for look
716 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
717 ph10 220 present in the pattern. These operators have additional parameters compared
718     with \d, etc, and these were not being taken into account when moving along
719 ph10 218 the compiled data. Specifically:
720 ph10 220
721     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
722     length.
724     (b) An item such as \pL+ within a repeated group could cause crashes or
725 ph10 218 loops.
726 ph10 220
727 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
728 ph10 220 "reference to non-existent subpattern" error.
730 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
732 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
733 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
734 ph10 211
735 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
736 ph10 218
737 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
738 ph10 223 character were causing crashes (broken optimization).
739 ph10 227
740 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
741 ph10 227 \p or \P) caused a compile-time loop.
743 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
744     break. For example, the unstudied pattern [\r\n]A does not match the string
745     "\r\nA" because change 7.0/46 below moves the current point on by two
746     characters after failing to match at the start. However, the pattern \nA
747 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
748     the same is true. There doesn't seem any very clean way out of this, but
749     what I have chosen to do makes the common cases work: PCRE now takes note
750     of whether there can be an explicit match for \r or \n anywhere in the
751     pattern, and if so, 7.0/46 no longer applies. As part of this change,
752     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
753     pattern has explicit CR or LF references.
754 ph10 222
755 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
756 ph10 223
757 ph10 227
758 ph10 189 Version 7.2 19-Jun-07
759     ---------------------
761 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
762     which is apparently normally available under Windows.
763 ph10 159
764     2. Re-jig the pcregrep tests with different newline settings in an attempt
765     to make them independent of the local environment's newline setting.
766 ph10 157
767 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
768 ph10 165
769 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
770     was not 2, because the output contained actual offsets. The recent new
771 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
772     usable with all link sizes.
774 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
775     stack recursion. This gives a massive performance boost under BSD, but just
776 ph10 165 a small improvement under Linux. However, it saves one field in the frame
777 ph10 164 in all cases.
778 ph10 172
779 ph10 166 6. Added more features from the forthcoming Perl 5.10:
780 ph10 172
781 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
782     recursion call. It refers to the nth most recently opened parentheses.
783 ph10 172
784 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
785 ph10 172 to be opened parentheses.
787     (c) Conditions that refer to capturing parentheses can be specified
788 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
789 ph10 172
790 ph10 168 (d) \K resets the start of the current match so that everything before
791 ph10 172 is not part of it.
793 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
794 ph10 172
795 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
796 ph10 172 reference syntax.
797 ph10 182
798 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
799 ph10 182 alternative starts with the same number.
800 ph10 172
801 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
803 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
806     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
807     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
808 ph10 170 for detecting groups that can match an empty string.
809 ph10 159
810 ph10 172 9. A pattern with a very large number of alternatives (more than several
811     hundred) was running out of internal workspace during the pre-compile
812     phase, where pcre_compile() figures out how much memory will be needed. A
813     bit of new cunning has reduced the workspace needed for groups with
814     alternatives. The 1000-alternative test pattern now uses 12 bytes of
815     workspace instead of running out of the 4096 that are available.
816 ph10 182
817 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
818 ph10 172
819 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
820     The report of the bug said:
821 ph10 182
822 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
823     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
824 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
825 ph10 185
826 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
827 ph10 185 it matched the wrong number of bytes.
828 ph10 172
829 ph10 179
830 ph10 155 Version 7.1 24-Apr-07
831 ph10 98 ---------------------
833 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
834 ph10 122 that is more "standard", making use of automake and other Autotools. There
835 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
836     on this.
837 ph10 111
838     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
839     for recursive directory scanning broke on some systems because the files
840     are not scanned in any specific order and on different systems the order
841     was different. A call to "sort" has been inserted into RunGrepTest for the
842     approprate test as a short-term fix. In the longer term there may be an
843 ph10 100 alternative.
844 ph10 111
845 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
846 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
847     people do their own conversions for various reasons). The problems
848     concerned the use of low-level troff macros .br and .in. I have therefore
849     removed all such uses from the man pages (some were redundant, some could
850 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
851     HTML has been updated to handle .nf/.fi and to complain if it encounters
852     .br or .in.
853 ph10 111
854 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
855 ph10 123 arranged for config.h to be included in the distribution, with the name
856 ph10 111 config.h.generic, for the benefit of those who have to compile without
857     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
859     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
860     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
861 ph10 127 makevp.bat for the current PCRE, using the additional files
862 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
863 ph10 111
864     6. A Windows user reported a minor discrepancy with test 2, which turned out
865     to be caused by a trailing space on an input line that had got lost in his
866 ph10 102 copy. The trailing space was an accident, so I've just removed it.
867 ph10 111
868 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
869 ph10 111 that is needed.
871 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
872     as "const" (a) because they are and (b) because it helps the PHP
873     maintainers who have recently made a script to detect big data structures
874 ph10 111 in the php code that should be moved to the .rodata section. I remembered
875     to update Builducptable as well, so it won't revert if ucptable.h is ever
876 ph10 105 re-created.
877 ph10 111
878     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
879 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
880 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
881     support is not required. This saves 1.5-2K of code, which is important in
882 ph10 107 some applications.
883 ph10 111
884 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
885 ph10 111 so as not to refer to the tables, even though these functions will never be
886     called when UTF-8 support is disabled. Otherwise there are problems with a
887     shared library.
889 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
891     (a) It was defining its arguments as char * instead of void *.
893 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
894     a long time ago when I wrote it, but is no longer the case.
896 ph10 118 The emulated memove() is provided for those environments that have neither
897 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
898 ph10 118 is clearly not the case, as these two bugs were recently reported.
899 ph10 123
900 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
901 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
902     pages, and it removes trailing spaces from listed files. It also creates
903     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
904     case, it wraps all the #defines with #ifndefs. This script should be run
905 ph10 111 before "make dist".
906 ph10 123
907 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
908     with Unicode property support.
909 ph10 123
910     (a) For a maximizing quantifier, if the two different cases of the
911     character were of different lengths in their UTF-8 codings (there are
912     some cases like this - I found 11), and the matching function had to
913 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
914     were both the same length.
915 ph10 123
916     (b) When PCRE was configured to use the heap rather than the stack for
917     recursion during matching, it was not correctly preserving the data for
918     the other case of a UTF-8 character when checking ahead for a match
919     while processing a minimizing repeat. If the check also involved
920 ph10 115 matching a wide character, but failed, corruption could cause an
921     erroneous result when trying to check for a repeat of the original
922     character.
923 ph10 123
924 ph10 116 13. Some tidying changes to the testing mechanism:
925 ph10 98
926 ph10 116 (a) The RunTest script now detects the internal link size and whether there
927     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
928 ph10 123 values substituted by "configure". (The RunGrepTest script already did
929     this for UTF-8.) The configure.ac script no longer substitutes the
930     relevant variables.
932 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
933     with length and offset values. This means that the output is different
934     for different internal link sizes. Test 2 is skipped for link sizes
935     other than 2 because of this, bypassing the problem. Unfortunately,
936     there was also a test in test 3 (the locale tests) that used /B and
937 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
938     I have added a new /Z option to pcretest that replaces the length and
939     offset values with spaces. This is now used to make test 3 independent
940 ph10 122 of link size. (Test 2 will be tidied up later.)
941 ph10 123
942     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
943 ph10 122 segmentation fault instead of returning the appropriate error message.
944 ph10 134
945 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
946 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
947     This doesn't seem right; it now treats the CRLF combination as the line
948     ending, and so does not match in that case. It's only a pattern such as ^$
949     that would hit this one: something like ^ABC$ would have failed after \r
950     and then tried again after \r\n.
952 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
953 ph10 134 in an attempt to make files that differ only in their line terminators
954     compare equal. This works on Linux.
955 ph10 142
956 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
957     as it exited. This is now fixed, thanks to valgrind.
958 ph10 142
959 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
960 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
961     was because its rules for how to advance for /g after matching an empty
962 ph10 143 string at the end of a line did not allow for this case. They now check for
963     it specially.
964 ph10 150
965     20. pcretest is supposed to handle patterns and data of any length, by
966     extending its buffers when necessary. It was getting this wrong when the
967 ph10 147 buffer for a data line had to be extended.
968 ph10 150
969 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
970 ph10 150 CRLF as a newline sequence.
971 ph10 152
972 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
973 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
974     I have nevertheless tidied it up.
975 ph10 111
976 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
977 ph10 123
978 ph10 153 24. Added a man page for pcre-config.
979 ph10 152
980 ph10 153
981 nigel 93 Version 7.0 19-Dec-06
982     ---------------------
984     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
985     moving to gcc 4.1.1.
987     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
988     sys/time.h, which is documented as needed for this function. It doesn't
989     seem to matter on Linux, but it showed up on some releases of OS X.
991     3. It seems that there are systems where bytes whose values are greater than
992     127 match isprint() in the "C" locale. The "C" locale should be the
993     default when a C program starts up. In most systems, only ASCII printing
994     characters match isprint(). This difference caused the output from pcretest
995     to vary, making some of the tests fail. I have changed pcretest so that:
997     (a) When it is outputting text in the compiled version of a pattern, bytes
998     other than 32-126 are always shown as hex escapes.
1000     (b) When it is outputting text that is a matched part of a subject string,
1001     it does the same, unless a different locale has been set for the match
1002     (using the /L modifier). In this case, it uses isprint() to decide.
1004     4. Fixed a major bug that caused incorrect computation of the amount of memory
1005     required for a compiled pattern when options that changed within the
1006     pattern affected the logic of the preliminary scan that determines the
1007     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1008     that the computed length was too small. The symptoms of this bug were
1009     either the PCRE error "internal error: code overflow" from pcre_compile(),
1010     or a glibc crash with a message such as "pcretest: free(): invalid next
1011     size (fast)". Examples of patterns that provoked this bug (shown in
1012     pcretest format) are:
1014     /(?-x: )/x
1015     /(?x)(?-x: \s*#\s*)/
1016     /((?i)[\x{c0}])/8
1017     /(?i:[\x{c0}])/8
1019     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1020     is now done differently.
1022     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1023     wrapper classes; (b) implement a new function in the C++ scanner that is
1024     more efficient than the old way of doing things because it avoids levels of
1025     recursion in the regex matching; (c) add a paragraph to the documentation
1026     for the FullMatch() function.
1028     6. The escape sequence \n was being treated as whatever was defined as
1029     "newline". Not only was this contrary to the documentation, which states
1030     that \n is character 10 (hex 0A), but it also went horribly wrong when
1031     "newline" was defined as CRLF. This has been fixed.
1033     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1034     was being set to -1 for the "end of line" case (supposedly a value that no
1035     character can have). Though this value is never used (the check for end of
1036     line is "zero bytes in current character"), it caused compiler complaints.
1037     I've changed it to 0xffffffff.
1039     8. In pcre_version.c, the version string was being built by a sequence of
1040     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1041     string (as it is for production releases) called a macro with an empty
1042     argument. The C standard says the result of this is undefined. The gcc
1043     compiler treats it as an empty string (which was what was wanted) but it is
1044     reported that Visual C gives an error. The source has been hacked around to
1045     avoid this problem.
1047     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1048     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1049     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1050     of them did).
1052     10. Originally, pcretest opened its input and output without "b"; then I was
1053     told that "b" was needed in some environments, so it was added for release
1054     5.0 to both the input and output. (It makes no difference on Unix-like
1055     systems.) Later I was told that it is wrong for the input on Windows. I've
1056     now abstracted the modes into two macros, to make it easier to fiddle with
1057     them, and removed "b" from the input mode under Windows.
1059     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1061     12. Added -help and --help to pcretest as an official way of being reminded
1062     of the options.
1064     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1065     and pcrecpp.cc because they annoy compilers at high warning levels.
1067     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1069     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1070     scripts are not C programs :-) and which was not noticed because it works
1071     on Linux.
1073     16. pcretest is supposed to handle any length of pattern and data line (as one
1074     line or as a continued sequence of lines) by extending its input buffer if
1075     necessary. This feature was broken for very long pattern lines, leading to
1076     a string of junk being passed to pcre_compile() if the pattern was longer
1077     than about 50K.
1079     17. I have done a major re-factoring of the way pcre_compile() computes the
1080     amount of memory needed for a compiled pattern. Previously, there was code
1081     that made a preliminary scan of the pattern in order to do this. That was
1082     OK when PCRE was new, but as the facilities have expanded, it has become
1083     harder and harder to keep it in step with the real compile phase, and there
1084     have been a number of bugs (see for example, 4 above). I have now found a
1085     cunning way of running the real compile function in a "fake" mode that
1086     enables it to compute how much memory it would need, while actually only
1087     ever using a few hundred bytes of working memory and without too many
1088     tests of the mode. This should make future maintenance and development
1089     easier. A side effect of this work is that the limit of 200 on the nesting
1090     depth of parentheses has been removed (though this was never a serious
1091     limitation, I suspect). However, there is a downside: pcre_compile() now
1092     runs more slowly than before (30% or more, depending on the pattern). I
1093     hope this isn't a big issue. There is no effect on runtime performance.
1095     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1096     newline (only possible for the last line of a file) and it was a
1097     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1099     19. Added additional timing features to pcretest. (1) The -tm option now times
1100     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1101     separate command line item, by a number that specifies the number of
1102     repeats to use when timing. The default is 50000; this gives better
1103     precision, but takes uncomfortably long for very large patterns.
1105     20. Extended pcre_study() to be more clever in cases where a branch of a
1106     subpattern has no definite first character. For example, (a*|b*)[cd] would
1107     previously give no result from pcre_study(). Now it recognizes that the
1108     first character must be a, b, c, or d.
1110     21. There was an incorrect error "recursive call could loop indefinitely" if
1111     a subpattern (or the entire pattern) that was being tested for matching an
1112     empty string contained only one non-empty item after a nested subpattern.
1113     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1114     incorrectly, because the \d was being skipped in the check.
1116     22. The pcretest program now has a new pattern option /B and a command line
1117     option -b, which is equivalent to adding /B to every pattern. This causes
1118     it to show the compiled bytecode, without the additional information that
1119     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1120     is the same as /B/I).
1122     23. A new optimization is now able automatically to treat some sequences such
1123     as a*b as a*+b. More specifically, if something simple (such as a character
1124     or a simple class like \d) has an unlimited quantifier, and is followed by
1125     something that cannot possibly match the quantified thing, the quantifier
1126     is automatically "possessified".
1128     24. A recursive reference to a subpattern whose number was greater than 39
1129     went wrong under certain circumstances in UTF-8 mode. This bug could also
1130     have affected the operation of pcre_study().
1132     25. Realized that a little bit of performance could be had by replacing
1133     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1135     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1137     27. Possessive quantifiers such as a++ were previously implemented by turning
1138     them into atomic groups such as ($>a+). Now they have their own opcodes,
1139     which improves performance. This includes the automatically created ones
1140     from 23 above.
1142     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1143     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1144     the first matched character to be a colon. This applied both to named and
1145     numbered groups.
1147     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1149     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1150     building PCRE on Windows easier, so I have included it in the distribution.
1152     31. There is now a check in pcretest against a ridiculously large number being
1153     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1154     loop, the loop is abandoned.
1156     32. Forward references to subpatterns in conditions such as (?(2)...) where
1157     subpattern 2 is defined later cause pcre_compile() to search forwards in
1158     the pattern for the relevant set of parentheses. This search went wrong
1159     when there were unescaped parentheses in a character class, parentheses
1160     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1162     33. "Subroutine" calls and backreferences were previously restricted to
1163     referencing subpatterns earlier in the regex. This restriction has now
1164     been removed.
1166     34. Added a number of extra features that are going to be in Perl 5.10. On the
1167     whole, these are just syntactic alternatives for features that PCRE had
1168     previously implemented using the Python syntax or my own invention. The
1169     other formats are all retained for compatibility.
1171     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1172     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1173     also .NET compatible.
1175     (b) A recursion or subroutine call to a named group can now be defined as
1176     (?&name) as well as (?P>name).
1178     (c) A backreference to a named group can now be defined as \k<name> or
1179     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1180     5.10, are also .NET compatible.
1182     (d) A conditional reference to a named group can now use the syntax
1183     (?(<name>) or (?('name') as well as (?(name).
1185     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1186     groups (named and numbered) that are never evaluated inline, but can be
1187     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1188     is always false. There may be only one alternative in such a group.
1190     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1191     as the simple (?(R). The condition is true only if the most recent
1192     recursion is that of the given number or name. It does not search out
1193     through the entire recursion stack.
1195     (g) The escape \gN or \g{N} has been added, where N is a positive or
1196     negative number, specifying an absolute or relative reference.
1198     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1199     some "unreachable code" warnings.
1201     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1202     things, this adds five new scripts.
1204     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1205     There were also incompatibilities regarding the handling of \Q..\E inside
1206     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1207     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1209     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1210     matches an empty string, and forcibly breaks the loop. There were bugs in
1211     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1212     against aaaa the result was just "a" rather than "aaaa", for example. Two
1213     separate and independent bugs (that affected different cases) have been
1214     fixed.
1216     39. Refactored the code to abolish the use of different opcodes for small
1217     capturing bracket numbers. This is a tidy that I avoided doing when I
1218     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1219     The new approach is not only tidier, it makes it possible to reduce the
1220     memory needed to fix the previous bug (38).
1222     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1223     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1224     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1225     mode.
1227     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1228     report.
1230     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1231     copy construction and assignment in the C++ wrapper.
1233     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1234     couple of bugs that could have given wrong results in the "--newline=crlf"
1235     case.
1237     44. Added a number of casts and did some reorganization of signed/unsigned int
1238     variables following suggestions from Dair Grant. Also renamed the variable
1239     "this" as "item" because it is a C++ keyword.
1241     45. Arranged for dftables to add
1243     #include "pcre_internal.h"
1245     to pcre_chartables.c because without it, gcc 4.x may remove the array
1246     definition from the final binary if PCRE is built into a static library and
1247     dead code stripping is activated.
1249     46. For an unanchored pattern, if a match attempt fails at the start of a
1250     newline sequence, and the newline setting is CRLF or ANY, and the next two
1251     characters are CRLF, advance by two characters instead of one.
1254 nigel 91 Version 6.7 04-Jul-06
1255     ---------------------
1257     1. In order to handle tests when input lines are enormously long, pcretest has
1258     been re-factored so that it automatically extends its buffers when
1259     necessary. The code is crude, but this _is_ just a test program. The
1260     default size has been increased from 32K to 50K.
1262     2. The code in pcre_study() was using the value of the re argument before
1263     testing it for NULL. (Of course, in any sensible call of the function, it
1264     won't be NULL.)
1266     3. The memmove() emulation function in pcre_internal.h, which is used on
1267     systems that lack both memmove() and bcopy() - that is, hardly ever -
1268     was missing a "static" storage class specifier.
1270     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1271     containing an extended class (one that cannot be represented by a bitmap
1272     because it contains high-valued characters or Unicode property items, e.g.
1273     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1274     pattern, but PCRE should not loop if you do not (it no longer does).
1275     [Detail: two cases were found: (a) a repeated subpattern containing an
1276     extended class; (b) a recursive reference to a subpattern that followed a
1277     previous extended class. It wasn't skipping over the extended class
1278     correctly when UTF-8 mode was not set.]
1280     5. A negated single-character class was not being recognized as fixed-length
1281     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1282     compile error "lookbehind assertion is not fixed length".
1284     6. The RunPerlTest auxiliary script was showing an unexpected difference
1285     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1286     write a Perl script that can interpret lines of an input file either as
1287     byte characters or as UTF-8, which is what "perltest" was being required to
1288     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1289     can't do is switch easily at run time between having the "use utf8;" pragma
1290     or not. In the end, I fudged it by using the RunPerlTest script to insert
1291     "use utf8;" explicitly for the UTF-8 tests.
1293     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1294     the end of the subject string, contrary to the documentation and to what
1295     Perl does. This was true of both matching functions. Now it matches only at
1296     the start of the subject and immediately after *internal* newlines.
1298     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1299     a pointer to an int instead of a pointer to an unsigned long int. This
1300     caused problems on 64-bit systems.
1302     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1303     instance of the 'standard' template library not being so standard".
1305     10. There was no check on the number of named subpatterns nor the maximum
1306     length of a subpattern name. The product of these values is used to compute
1307     the size of the memory block for a compiled pattern. By supplying a very
1308     long subpattern name and a large number of named subpatterns, the size
1309     computation could be caused to overflow. This is now prevented by limiting
1310     the length of names to 32 characters, and the number of named subpatterns
1311     to 10,000.
1313     11. Subpatterns that are repeated with specific counts have to be replicated in
1314     the compiled pattern. The size of memory for this was computed from the
1315     length of the subpattern and the repeat count. The latter is limited to
1316     65535, but there was no limit on the former, meaning that integer overflow
1317     could in principle occur. The compiled length of a repeated subpattern is
1318     now limited to 30,000 bytes in order to prevent this.
1320     12. Added the optional facility to have named substrings with the same name.
1322     13. Added the ability to use a named substring as a condition, using the
1323     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1324     are numbers (not recommended). Forward references are permitted.
1326     14. Added forward references in named backreferences (if you see what I mean).
1328     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1329     pattern could run off the end of the subject. For example, the pattern
1330     "(?s)(.{1,5})"8 did this with the subject "ab".
1332     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1333     PCRE_CASELESS was set when matching characters that were quantified with ?
1334     or *.
1336     17. A character class other than a single negated character that had a minimum
1337     but no maximum quantifier - for example [ab]{6,} - was not handled
1338     correctly by pce_dfa_exec(). It would match only one character.
1340     18. A valid (though odd) pattern that looked like a POSIX character
1341     class but used an invalid character after [ (for example [[,abc,]]) caused
1342     pcre_compile() to give the error "Failed: internal error: code overflow" or
1343     in some cases to crash with a glibc free() error. This could even happen if
1344     the pattern terminated after [[ but there just happened to be a sequence of
1345     letters, a binary zero, and a closing ] in the memory that followed.
1347     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1348     over the years. Originally (before any Unicode support), just the bottom 8
1349     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1350     output from "man perlunicode" includes this:
1352     The regular expression compiler produces polymorphic opcodes. That
1353     is, the pattern adapts to the data and automatically switches to
1354     the Unicode character scheme when presented with Unicode data--or
1355     instead uses a traditional byte scheme when presented with byte
1356     data.
1358     Sadly, a wide octal escape does not cause a switch, and in a string with
1359     no other multibyte characters, these octal escapes are treated as before.
1360     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1361     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1362     Unicode string.
1364     I have not perpetrated such confusion in PCRE. Up till now, it took just
1365     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1366     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1367     translate to the appropriate multibyte character.
1369     29. Applied some refactoring to reduce the number of warnings from Microsoft
1370     and Borland compilers. This has included removing the fudge introduced
1371     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1372     a warning about an unused variable.
1374     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1375     characters since release 4.0, because Perl (from release 5.004) does not.
1376     [Or at least, is documented not to: some releases seem to be in conflict
1377     with the documentation.] However, when a pattern was studied with
1378     pcre_study() and all its branches started with \s, PCRE still included VT
1379     as a possible starting character. Of course, this did no harm; it just
1380     caused an unnecessary match attempt.
1382     22. Removed a now-redundant internal flag bit that recorded the fact that case
1383     dependency changed within the pattern. This was once needed for "required
1384     byte" processing, but is no longer used. This recovers a now-scarce options
1385     bit. Also moved the least significant internal flag bit to the most-
1386     significant bit of the word, which was not previously used (hangover from
1387     the days when it was an int rather than a uint) to free up another bit for
1388     the future.
1390     23. Added support for CRLF line endings as well as CR and LF. As well as the
1391     default being selectable at build time, it can now be changed at runtime
1392     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1393     specify that it is scanning data with non-default line endings.
1395     24. Changed the definition of CXXLINK to make it agree with the definition of
1396     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1398     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1399     recursions. This makes a big different to stack usage for some patterns.
1401     26. If a subpattern containing a named recursion or subroutine reference such
1402     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1403     the space required for the compiled pattern went wrong and gave too small a
1404     value. Depending on the environment, this could lead to "Failed: internal
1405     error: code overflow at offset 49" or "glibc detected double free or
1406     corruption" errors.
1408     27. Applied patches from Google (a) to support the new newline modes and (b) to
1409     advance over multibyte UTF-8 characters in GlobalReplace.
1411     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1412     difference for some implementation of PCRE in some Windows version.
1414     29. Added some extra testing facilities to pcretest:
1416     \q<number> in a data line sets the "match limit" value
1417     \Q<number> in a data line sets the "match recursion limt" value
1418     -S <number> sets the stack size, where <number> is in megabytes
1420     The -S option isn't available for Windows.
1423 nigel 89 Version 6.6 06-Feb-06
1424     ---------------------
1426     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1427     in pcreposix.h. I have copied the definition from pcre.h.
1429     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1430     because pcre.h is no longer a built file.
1432     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1433     not normally included in the compiled code.
1436 nigel 87 Version 6.5 01-Feb-06
1437     ---------------------
1439     1. When using the partial match feature with pcre_dfa_exec(), it was not
1440     anchoring the second and subsequent partial matches at the new starting
1441     point. This could lead to incorrect results. For example, with the pattern
1442     /1234/, partially matching against "123" and then "a4" gave a match.
1444     2. Changes to pcregrep:
1446     (a) All non-match returns from pcre_exec() were being treated as failures
1447     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1448     error message is output. Some extra information is given for the
1450     probably the only errors that are likely to be caused by users (by
1451     specifying a regex that has nested indefinite repeats, for instance).
1452     If there are more than 20 of these errors, pcregrep is abandoned.
1454     (b) A binary zero was treated as data while matching, but terminated the
1455     output line if it was written out. This has been fixed: binary zeroes
1456     are now no different to any other data bytes.
1458     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1459     used to set a locale for matching. The --locale=xxxx long option has
1460     been added (no short equivalent) to specify a locale explicitly on the
1461     pcregrep command, overriding the environment variables.
1463     (d) When -B was used with -n, some line numbers in the output were one less
1464     than they should have been.
1466     (e) Added the -o (--only-matching) option.
1468     (f) If -A or -C was used with -c (count only), some lines of context were
1469     accidentally printed for the final match.
1471     (g) Added the -H (--with-filename) option.
1473     (h) The combination of options -rh failed to suppress file names for files
1474     that were found from directory arguments.
1476     (i) Added the -D (--devices) and -d (--directories) options.
1478     (j) Added the -F (--fixed-strings) option.
1480     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1482     (l) Added the --colo(u)r option.
1484     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1485     is not present by default.
1487     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1488     items such as (?R) or (?1), when the recursion could match a number of
1489     alternatives. If it matched one of the alternatives, but subsequently,
1490     outside the recursion, there was a failure, the code tried to back up into
1491     the recursion. However, because of the way PCRE is implemented, this is not
1492     possible, and the result was an incorrect result from the match.
1494     In order to prevent this happening, the specification of recursion has
1495     been changed so that all such subpatterns are automatically treated as
1496     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1498     4. I had overlooked the fact that, in some locales, there are characters for
1499     which isalpha() is true but neither isupper() nor islower() are true. In
1500     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1501     and ordfeminine) are like this. This affected the treatment of \w and \W
1502     when they appeared in character classes, but not when they appeared outside
1503     a character class. The bit map for "word" characters is now created
1504     separately from the results of isalnum() instead of just taking it from the
1505     upper, lower, and digit maps. (Plus the underscore character, of course.)
1507     5. The above bug also affected the handling of POSIX character classes such as
1508     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1509     permanent tables. Instead, the bit maps for such a class were previously
1510     created as the appropriate unions of the upper, lower, and digit bitmaps.
1511     Now they are created by subtraction from the [[:word:]] class, which has
1512     its own bitmap.
1514     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1515     It is created by subtracting the vertical space characters (\x09, \x0a,
1516     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1517     subtraction was done in the overall bitmap for a character class, meaning
1518     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1519     be recognized. This bug has been fixed.
1521     7. Patches from the folks at Google:
1523     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1524     real life, but is still worth protecting against".
1526     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1527     regular expressions".
1529     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1530     have it.
1532     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1533     "configure" and the latter not, in order to fix a problem somebody had
1534     with compiling the Arg class on HP-UX.
1536     (e) Improve the error-handling of the C++ wrapper a little bit.
1538     (f) New tests for checking recursion limiting.
1540     8. The pcre_memmove() function, which is used only if the environment does not
1541     have a standard memmove() function (and is therefore rarely compiled),
1542     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1543     returning a result (though PCRE never actually uses the result).
1545     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1546     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1547     returned instead of calling malloc() with an overflowing number that would
1548     most likely cause subsequent chaos.
1550     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1552     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1553     with this option is matched, the nmatch and pmatch options of regexec() are
1554     ignored.
1556     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1557     provided in case anyone wants to the the POSIX interface with UTF-8
1558     strings.
1560     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1561     C++ linking (needed for some HP-UX environments).
1563     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1564     (unused parameter) and in the pcre_printint() function (omitted "default"
1565     switch label when the default is to do nothing).
1567     15. Added some code to make it possible, when PCRE is compiled as a C++
1568     library, to replace subject pointers for pcre_exec() with a smart pointer
1569     class, thus making it possible to process discontinuous strings.
1571     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1572     much the same function. They were added by different people who were trying
1573     to make PCRE easy to compile on non-Unix systems. It has been suggested
1574     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1575     for compiling on Windows systems. I have therefore replaced it with
1576     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1577     defaults to "extern" for C or "extern C" for C++, which works fine on
1578     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1579     SCOPE with something explicit in config.h. In addition:
1581     (a) pcreposix.h still had just "extern" instead of either of these macros;
1582     I have replaced it with PCRE_DATA_SCOPE.
1584     (b) Functions such as _pcre_xclass(), which are internal to the library,
1585     but external in the C sense, all had PCRE_EXPORT in their definitions.
1586     This is apparently wrong for the Windows case, so I have removed it.
1587     (It makes no difference on Unix-like systems.)
1589     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1590     of recursive calls to match(). This is different to MATCH_LIMIT because
1591     that limits the total number of calls to match(), not all of which increase
1592     the depth of recursion. Limiting the recursion depth limits the amount of
1593     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1594     when PCRE is compiled, and changed at run time. A patch from Google adds
1595     this functionality to the C++ interface.
1597     18. Changes to the handling of Unicode character properties:
1599     (a) Updated the table to Unicode 4.1.0.
1601     (b) Recognize characters that are not in the table as "Cn" (undefined).
1603     (c) I revised the way the table is implemented to a much improved format
1604     which includes recognition of ranges. It now supports the ranges that
1605     are defined in UnicodeData.txt, and it also amalgamates other
1606     characters into ranges. This has reduced the number of entries in the
1607     table from around 16,000 to around 3,000, thus reducing its size
1608     considerably. I realized I did not need to use a tree structure after
1609     all - a binary chop search is just as efficient. Having reduced the
1610     number of entries, I extended their size from 6 bytes to 8 bytes to
1611     allow for more data.
1613     (d) Added support for Unicode script names via properties such as \p{Han}.
1615     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1616     matching that character.
1618     20. When matching a repeated Unicode property with a minimum greater than zero,
1619     (for example \pL{2,}), PCRE could look past the end of the subject if it
1620     reached it while seeking the minimum number of characters. This could
1621     happen only if some of the characters were more than one byte long, because
1622     there is a check for at least the minimum number of bytes.
1624     21. Refactored the implementation of \p and \P so as to be more general, to
1625     allow for more different types of property in future. This has changed the
1626     compiled form incompatibly. Anybody with saved compiled patterns that use
1627     \p or \P will have to recompile them.
1629     22. Added "Any" and "L&" to the supported property types.
1631     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1632     but give a compile time error if the value is greater than 0xff.
1634     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1635     accidentally not being installed or uninstalled.
1637     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1638     made were to insert the current release number. This seemed silly, because
1639     it made things harder for people building PCRE on systems that don't run
1640     "configure". I have turned pcre.h into a distributed file, no longer built
1641     by "configure", with the version identification directly included. There is
1642     no longer a pcre.h.in file.
1644     However, this change necessitated a change to the pcre-config script as
1645     well. It is built from pcre-config.in, and one of the substitutions was the
1646     release number. I have updated configure.ac so that ./configure now finds
1647     the release number by grepping pcre.h.
1649     26. Added the ability to run the tests under valgrind.
1652 nigel 85 Version 6.4 05-Sep-05
1653     ---------------------
1655     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1656     "--" to be printed when multiple files were scanned, even when none of the
1657     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1658     consider it to be a bug, and have restored the previous behaviour.
1660     2. A couple of code tidies to get rid of compiler warnings.
1662     3. The pcretest program used to cheat by referring to symbols in the library
1663     whose names begin with _pcre_. These are internal symbols that are not
1664     really supposed to be visible externally, and in some environments it is
1665     possible to suppress them. The cheating is now confined to including
1666     certain files from the library's source, which is a bit cleaner.
1668     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1669     file's purpose clearer.
1671     5. Reorganized pcre_ucp_findchar().
1674 nigel 83 Version 6.3 15-Aug-05
1675     ---------------------
1677     1. The file libpcre.pc.in did not have general read permission in the tarball.
1679     2. There were some problems when building without C++ support:
1681     (a) If C++ support was not built, "make install" and "make test" still
1682     tried to test it.
1684     (b) There were problems when the value of CXX was explicitly set. Some
1685     changes have been made to try to fix these, and ...
1687     (c) --disable-cpp can now be used to explicitly disable C++ support.
1689     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1690     backslash in a target when C++ was disabled. This confuses some
1691     versions of "make", apparently. Using an intermediate variable solves
1692     this. (Same for CPP_LOBJ.)
1694     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1695     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1696     necessary on certain architectures.
1698     4. Added a setting of -export-symbols-regex to the link command to remove
1699     those symbols that are exported in the C sense, but actually are local
1700     within the library, and not documented. Their names all begin with
1701     "_pcre_". This is not a perfect job, because (a) we have to except some
1702     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1703     available (and never for static libraries). I have made a note to try to
1704     find a way round (a) in the future.
1707 nigel 81 Version 6.2 01-Aug-05
1708     ---------------------
1710     1. There was no test for integer overflow of quantifier values. A construction
1711     such as {1111111111111111} would give undefined results. What is worse, if
1712     a minimum quantifier for a parenthesized subpattern overflowed and became
1713     negative, the calculation of the memory size went wrong. This could have
1714     led to memory overwriting.
1716     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1718     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1719     operating environments where this matters.
1721     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1722     PCRE options from within the C++ wrapper.
1724     5. Named capturing subpatterns were not being correctly counted when a pattern
1725     was compiled. This caused two problems: (a) If there were more than 100
1726     such subpatterns, the calculation of the memory needed for the whole
1727     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1728     back references of the form \12, where the number was greater than 9, were
1729     not recognized as back references, even though there were sufficient
1730     previous subpatterns.
1732     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1733     versions of gcc, e.g. 2.95.4.
1736 nigel 79 Version 6.1 21-Jun-05
1737     ---------------------
1739     1. There was one reference to the variable "posix" in pcretest.c that was not
1740     surrounded by "#if !defined NOPOSIX".
1742     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1743     the cross-check on the old pcre_info() function, for the benefit of the
1744     cut-down version of PCRE that is currently imported into Exim.
1746     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1747     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1748     patterns that start (?i) but I don't think that matters. The use of (?i) is
1749     just an example; this all applies to the other options as well.
1751     4. Since libtool seems to echo the compile commands it is issuing, the output
1752     from "make" can be reduced a bit by putting "@" in front of each libtool
1753     compile command.
1755     5. Patch from the folks at Google for configure.in to be a bit more thorough
1756     in checking for a suitable C++ installation before trying to compile the
1757     C++ stuff. This should fix a reported problem when a compiler was present,
1758     but no suitable headers.
1760     6. The man pages all had just "PCRE" as their title. I have changed them to
1761     be the relevant file name. I have also arranged that these names are
1762     retained in the file doc/pcre.txt, which is a concatenation in text format
1763     of all the man pages except the little individual ones for each function.
1765     7. The NON-UNIX-USE file had not been updated for the different set of source
1766     files that come with release 6. I also added a few comments about the C++
1767     wrapper.
1770 nigel 77 Version 6.0 07-Jun-05
1771     ---------------------
1773     1. Some minor internal re-organization to help with my DFA experiments.
1775     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1776     didn't matter for the library itself when fully configured, but did matter
1777     when compiling without UCP support, or within Exim, where the ucp files are
1778     not imported.
1780     3. Refactoring of the library code to split up the various functions into
1781     different source modules. The addition of the new DFA matching code (see
1782     below) to a single monolithic source would have made it really too
1783     unwieldy, quite apart from causing all the code to be include in a
1784     statically linked application, when only some functions are used. This is
1785     relevant even without the DFA addition now that patterns can be compiled in
1786     one application and matched in another.
1788     The downside of splitting up is that there have to be some external
1789     functions and data tables that are used internally in different modules of
1790     the library but which are not part of the API. These have all had their
1791     names changed to start with "_pcre_" so that they are unlikely to clash
1792     with other external names.
1794     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1795     a different (DFA) algorithm. Although it is slower than the original
1796     function, it does have some advantages for certain types of matching
1797     problem.
1799     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1800     including restarting after a partial match.
1802     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1803     defined when compiling for Windows was sent to me. I have put it into the
1804     code, though I have no means of testing or verifying it.
1806     7. Added the pcre_refcount() auxiliary function.
1808     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1809     match before or at the first newline in the subject string. In pcretest,
1810     the /f option on a pattern can be used to set this.
1812     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1813     would behave wrongly. This has been present in PCRE since release 4.0.
1815     10. A number of changes to the pcregrep command:
1817     (a) Refactored how -x works; insert ^(...)$ instead of setting
1818     PCRE_ANCHORED and checking the length, in preparation for adding
1819     something similar for -w.
1821     (b) Added the -w (match as a word) option.
1823     (c) Refactored the way lines are read and buffered so as to have more
1824     than one at a time available.
1826     (d) Implemented a pcregrep test script.
1828     (e) Added the -M (multiline match) option. This allows patterns to match
1829     over several lines of the subject. The buffering ensures that at least
1830     8K, or the rest of the document (whichever is the shorter) is available
1831     for matching (and similarly the previous 8K for lookbehind assertions).
1833     (f) Changed the --help output so that it now says
1835     -w, --word-regex(p)
1837     instead of two lines, one with "regex" and the other with "regexp"
1838     because that confused at least one person since the short forms are the
1839     same. (This required a bit of code, as the output is generated
1840     automatically from a table. It wasn't just a text change.)
1842     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1843     option but starts with a hyphen. Could be a pattern or a path name
1844     starting with a hyphen, for instance.
1846     (h) "-" can be given as a file name to represent stdin.
1848     (i) When file names are being printed, "(standard input)" is used for
1849     the standard input, for compatibility with GNU grep. Previously
1850     "<stdin>" was used.
1852     (j) The option --label=xxx can be used to supply a name to be used for
1853     stdin when file names are being printed. There is no short form.
1855     (k) Re-factored the options decoding logic because we are going to add
1856     two more options that take data. Such options can now be given in four
1857     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1859     (l) Added the -A, -B, and -C options for requesting that lines of context
1860     around matches be printed.
1862     (m) Added the -L option to print the names of files that do not contain
1863     any matching lines, that is, the complement of -l.
1865     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1866     continue to scan other files.
1868     (o) The -s option was incorrectly implemented. For compatibility with other
1869     greps, it now suppresses the error message for a non-existent or non-
1870     accessible file (but not the return code). There is a new option called
1871     -q that suppresses the output of matching lines, which was what -s was
1872     previously doing.
1874     (p) Added --include and --exclude options to specify files for inclusion
1875     and exclusion when recursing.
1877     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1878     Hopefully, it now does.
1880     12. Missing cast in pcre_study().
1882     13. Added an "uninstall" target to the makefile.
1884     14. Replaced "extern" in the function prototypes in Makefile.in with
1885     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1886     world, but is set differently for Windows.
1888     15. Added a second compiling function called pcre_compile2(). The only
1889     difference is that it has an extra argument, which is a pointer to an
1890     integer error code. When there is a compile-time failure, this is set
1891     non-zero, in addition to the error test pointer being set to point to an
1892     error message. The new argument may be NULL if no error number is required
1893     (but then you may as well call pcre_compile(), which is now just a
1894     wrapper). This facility is provided because some applications need a
1895     numeric error indication, but it has also enabled me to tidy up the way
1896     compile-time errors are handled in the POSIX wrapper.
1898     16. Added VPATH=.libs to the makefile; this should help when building with one
1899     prefix path and installing with another. (Or so I'm told by someone who
1900     knows more about this stuff than I do.)
1902     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1903     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1904     match everything, including newlines. This is not POSIX-compatible, but
1905     somebody wanted the feature. From pcretest it can be activated by using
1906     both the P and the s flags.
1908     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1910     19. libpcre.pc was being incorrectly installed as executable.
1912     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1913     it now also looks for '\r' so that it will work unmodified on Windows.
1915     21. Added Google's contributed C++ wrapper to the distribution.
1917     22. Added some untidy missing memory free() calls in pcretest, to keep
1918     Electric Fence happy when testing.
1922 nigel 75 Version 5.0 13-Sep-04
1923     ---------------------
1925     1. Internal change: literal characters are no longer packed up into items
1926     containing multiple characters in a single byte-string. Each character
1927     is now matched using a separate opcode. However, there may be more than one
1928     byte in the character in UTF-8 mode.
1930     2. The pcre_callout_block structure has two new fields: pattern_position and
1931     next_item_length. These contain the offset in the pattern to the next match
1932     item, and its length, respectively.
1934     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1935     insertion of callouts before each pattern item. Added the /C option to
1936     pcretest to make use of this.
1938     4. On the advice of a Windows user, the lines
1940     #if defined(_WIN32) || defined(WIN32)
1941     _setmode( _fileno( stdout ), 0x8000 );
1942     #endif /* defined(_WIN32) || defined(WIN32) */
1944     have been added to the source of pcretest. This apparently does useful
1945     magic in relation to line terminators.
1947     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1948     for the benefit of those environments where the "b" makes a difference.
1950     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1951     to know about it. I have put a hack into configure.in that adds in code
1952     to set GCC=yes if CC=icc. This seems to end up at a point in the
1953     generated configure script that is early enough to affect the setting of
1954     compiler options, which is what is needed, but I have no means of testing
1955     whether it really works. (The user who reported this had patched the
1956     generated configure script, which of course I cannot do.)
1958     LATER: After change 22 below (new libtool files), the configure script
1959     seems to know about icc (and also ecc). Therefore, I have commented out
1960     this hack in configure.in.
1962     7. Added support for pkg-config (2 patches were sent in).
1964     8. Negated POSIX character classes that used a combination of internal tables
1965     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1966     [[:^ascii]]. Typically, they would match almost any characters. The other
1967     POSIX classes were not broken in this way.
1969     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1970     to find the match, as PCRE was deluded into thinking that the match had to
1971     start at the start point or following a newline. The same bug applied to
1972     patterns with negative forward assertions or any backward assertions
1973     preceding ".*" at the start, unless the pattern required a fixed first
1974     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1976     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1977     starting at the last subject character, bytes beyond the end of the subject
1978     string were read.
1980     11. Renamed the variable "class" as "classbits" to make life easier for C++
1981     users. (Previously there was a macro definition, but it apparently wasn't
1982     enough.)
1984     12. Added the new field "tables" to the extra data so that tables can be passed
1985     in at exec time, or the internal tables can be re-selected. This allows
1986     a compiled regex to be saved and re-used at a later time by a different
1987     program that might have everything at different addresses.
1989     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1990     -R library as well as a -L library.
1992     14. The debugging options of pcretest (-d on the command line or D on a
1993     pattern) showed incorrect output for anything following an extended class
1994     that contained multibyte characters and which was followed by a quantifier.
1996     15. Added optional support for general category Unicode character properties
1997     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1998     support. It adds about 90K to the size of the library. The meanings of the
1999     inbuilt class escapes such as \d and \s have NOT been changed.
2001     16. Updated pcredemo.c to include calls to free() to release the memory for the
2002     compiled pattern.
2004     17. The generated file chartables.c was being created in the source directory
2005     instead of in the building directory. This caused the build to fail if the
2006     source directory was different from the building directory, and was
2007     read-only.
2009     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2010     file. No doubt somebody will tell me if they don't make sense... Also added
2011     Dan Mooney's comments about building on OpenVMS.
2013     19. Added support for partial matching via the PCRE_PARTIAL option for
2014     pcre_exec() and the \P data escape in pcretest.
2016     20. Extended pcretest with 3 new pattern features:
2018     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2019     write the compiled pattern to the file whose name is "rest-of-line".
2020     This is a straight binary dump of the data, with the saved pointer to
2021     the character tables forced to be NULL. The study data, if any, is
2022     written too. After writing, pcretest reads a new pattern.
2024     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2025     compiled pattern from the given file. There must not be any
2026     occurrences of "<" in the file name (pretty unlikely); if there are,
2027     pcretest will instead treat the initial "<" as a pattern delimiter.
2028     After reading in the pattern, pcretest goes on to read data lines as
2029     usual.
2031     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2032     and 16-bit fields in a compiled pattern, to simulate a pattern that
2033     was compiled on a host of opposite endianness.
2035     21. The pcre-exec() function can now cope with patterns that were compiled on
2036     hosts of opposite endianness, with this restriction:
2038     As for any compiled expression that is saved and used later, the tables
2039     pointer field cannot be preserved; the extra_data field in the arguments
2040     to pcre_exec() should be used to pass in a tables address if a value
2041     other than the default internal tables were used at compile time.
2043     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2044     now diagnosed as an error. Previously, most of the time, a negative number
2045     would have been treated as zero, but if in addition "ovector" was passed as
2046     NULL, a crash could occur.
2048     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2049     new versions from the libtool 1.5 distribution (the last one is a copy of
2050     a file called libtool.m4). This seems to have fixed the need to patch
2051     "configure" to support Darwin 1.3 (which I used to do). However, I still
2052     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2053     workstation).
2055     24. Changed the PCRE licence to be the more standard "BSD" licence.
2058 nigel 73 Version 4.5 01-Dec-03
2059     ---------------------
2061     1. There has been some re-arrangement of the code for the match() function so
2062     that it can be compiled in a version that does not call itself recursively.
2063     Instead, it keeps those local variables that need separate instances for
2064     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2065     needs to "recurse". Keeping track of where control must go is done by means
2066     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2067     hide most of the details from the main code, and operates only if
2068     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2069     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2070     operating.
2072     To make it easier for callers to provide specially tailored get/free
2073     functions for this usage, two new functions, pcre_stack_malloc, and
2074     pcre_stack_free, are used. They are always called in strict stacking order,
2075     and the size of block requested is always the same.
2077     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2078     PCRE has been compiled to use the stack or the heap for recursion. The
2079     -C option of pcretest uses this to show which version is compiled.
2081     A new data escape \S, is added to pcretest; it causes the amounts of store
2082     obtained and freed by both kinds of malloc/free at match time to be added
2083     to the output.
2085     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2086     what's available on my current Linux desktop machine.
2088     3. When matching a UTF-8 string, the test for a valid string at the start has
2089     been extended. If start_offset is not zero, PCRE now checks that it points
2090     to a byte that is the start of a UTF-8 character. If not, it returns
2091     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2092     this is necessary because there may be backward assertions in the pattern.
2093     When matching the same subject several times, it may save resources to use
2094     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2096     4. The code for checking the validity of UTF-8 strings has been tightened so
2097     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2098     containing "overlong sequences".
2100     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2101     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2102     should have been "&", but it just so happened that all the cases this let
2103     through by mistake were picked up later in the function.
2105     6. I had used a variable called "isblank" - this is a C99 function, causing
2106     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2108     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2109     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2110     so the version is shown; (c) stop "make test" echoing "./RunTest".
2112     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2114     9. The prototype for memmove() for systems that don't have it was using
2115     size_t, but the inclusion of the header that defines size_t was later. I've
2116     moved the #includes for the C headers earlier to avoid this.
2118     10. Added some adjustments to the code to make it easier to compiler on certain
2119     special systems:
2121     (a) Some "const" qualifiers were missing.
2122     (b) Added the macro EXPORT before all exported functions; by default this
2123     is defined to be empty.
2124     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2125     that it reads its output file name as an argument instead of writing
2126     to the standard output and assuming this can be redirected.
2128     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2129     class containing characters with values greater than 255, PCRE compilation
2130     went into a loop.
2132     12. A recursive reference to a subpattern that was within another subpattern
2133     that had a minimum quantifier of zero caused PCRE to crash. For example,
2134     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2135     recursion. If the recursively-called subpattern itself had a zero repeat,
2136     that was OK.
2138     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2139     buffer into which it was copied (for escape processing) was still set at
2140     1024, so long lines caused crashes.
2142     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2143     "internal error: code overflow...". This applied to any character class
2144     that was followed by a possessive quantifier.
2146     15. Modified the Makefile to add libpcre.la as a prerequisite for
2147     libpcreposix.la because I was told this is needed for a parallel build to
2148     work.
2150     16. If a pattern that contained .* following optional items at the start was
2151     studied, the wrong optimizing data was generated, leading to matching
2152     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2153     matching string must start with a or b or c. The correct conclusion for
2154     this pattern is that a match can start with any character.
2157 nigel 71 Version 4.4 13-Aug-03
2158     ---------------------
2160     1. In UTF-8 mode, a character class containing characters with values between
2161     127 and 255 was not handled correctly if the compiled pattern was studied.
2162     In fixing this, I have also improved the studying algorithm for such
2163     classes (slightly).
2165     2. Three internal functions had redundant arguments passed to them. Removal
2166     might give a very teeny performance improvement.
2168     3. Documentation bug: the value of the capture_top field in a callout is *one
2169     more than* the number of the hightest numbered captured substring.
2171     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2172     in incorrectly linking with a previously installed version. They now link
2173     explicitly with libpcre.la.
2175     5. configure.in no longer needs to recognize Cygwin specially.
2177     6. A problem in pcre.in for Windows platforms is fixed.
2179     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2180     pcretest, it used to include the size of the study block as part of its
2181     output. Unfortunately, the structure contains a field that has a different
2182     size on different hardware architectures. This meant that the tests that
2183     showed this size failed. As the block is currently always of a fixed size,
2184     this information isn't actually particularly useful in pcretest output, so
2185     I have just removed it.
2187     8. Three pre-processor statements accidentally did not start in column 1.
2188     Sadly, there are *still* compilers around that complain, even though
2189     standard C has not required this for well over a decade. Sigh.
2191     9. In pcretest, the code for checking callouts passed small integers in the
2192     callout_data field, which is a void * field. However, some picky compilers
2193     complained about the casts involved for this on 64-bit systems. Now
2194     pcretest passes the address of the small integer instead, which should get
2195     rid of the warnings.
2197     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2198     both compile and run time, and gives an error if an invalid UTF-8 sequence
2199     is found. There is a option for disabling this check in cases where the
2200     string is known to be correct and/or the maximum performance is wanted.
2202     11. In response to a bug report, I changed one line in Makefile.in from
2204     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2205     to
2206     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2208     to look similar to other lines, but I have no way of telling whether this
2209     is the right thing to do, as I do not use Windows. No doubt I'll get told
2210     if it's wrong...
2213 nigel 69 Version 4.3 21-May-03
2214     ---------------------
2216     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2217     Makefile.
2219     2. Some refactoring to improve the quality of the code:
2221     (i) The utf8_table... variables are now declared "const".
2223     (ii) The code for \cx, which used the "case flipping" table to upper case
2224     lower case letters, now just substracts 32. This is ASCII-specific,
2225     but the whole concept of \cx is ASCII-specific, so it seems
2226     reasonable.
2228     (iii) PCRE was using its character types table to recognize decimal and
2229     hexadecimal digits in the pattern. This is silly, because it handles
2230     only 0-9, a-f, and A-F, but the character types table is locale-
2231     specific, which means strange things might happen. A private
2232     table is now used for this - though it costs 256 bytes, a table is
2233     much faster than multiple explicit tests. Of course, the standard
2234     character types table is still used for matching digits in subject
2235     strings against \d.
2237     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2238     ending in _t are). So I've renamed it as ESC_tee.
2240     3. The first argument for regexec() in the POSIX wrapper should have been
2241     defined as "const".
2243     4. Changed pcretest to use malloc() for its buffers so that they can be
2244     Electric Fenced for debugging.
2246     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2247     to read one or more bytes before the start of the subject string. Often this
2248     had no effect on PCRE's behaviour, but in some circumstances it could
2249     provoke a segmentation fault.
2251     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2252     to try to read one or more bytes before the start of the subject string.
2254     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2255     UTF-8 support could misbehave in various ways if the subject string
2256     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2257     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2258     back over UTF-8 characters.)
2261 nigel 67 Version 4.2 14-Apr-03
2262     ---------------------
2264     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2266     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2267     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2268     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2269     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2270     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2271     and BUILD_EXEEXT
2272     Note: automatic setting of the BUILD variables is not yet working
2273     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2274     compile-time but not at link-time
2275     [LINK]: use for linking executables only
2276     make different versions for Windows and non-Windows
2277     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2278     libraries
2279     [LINK_FOR_BUILD]: new variable
2280     [OBJEXT]: use throughout
2281     [EXEEXT]: use throughout
2282     <winshared>: new target
2283     <wininstall>: new target
2284     <dftables.o>: use native compiler
2285     <dftables>: use native linker
2286     <install>: handle Windows platform correctly
2287     <clean>: ditto
2288     <check>: ditto
2289     copy DLL to top builddir before testing
2291     As part of these changes, -no-undefined was removed again. This was reported
2292     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2293     in any case.
2295     3. Some tidies to get rid of compiler warnings:
2297     . In the match_data structure, match_limit was an unsigned long int, whereas
2298     match_call_count was an int. I've made them both unsigned long ints.
2300     . In pcretest the fact that a const uschar * doesn't automatically cast to
2301     a void * provoked a warning.
2303     . Turning on some more compiler warnings threw up some "shadow" variables
2304     and a few more missing casts.
2306     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2307     option, a class that contained a single character with a value between 128
2308     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2310     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2311     option, a class that contained several characters, but with at least one
2312     whose value was between 128 and 255 caused PCRE to crash.
2315 nigel 65 Version 4.1 12-Mar-03
2316     ---------------------
2317 nigel 63
2318 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2319     needed, and a string in dftables.c that was longer than standard compilers are
2320     required to support.
2322     2. Compiling with Sun's compiler found a few more places where the code could
2323     be tidied up in order to avoid warnings.
2325     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2326     first of these names is deprecated in the latest Autoconf in favour of the name
2327     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2328     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2329     analogy I have changed it to CFLAGS_FOR_BUILD.
2331     4. Added -no-undefined to the linking command in the Makefile, because this is
2332     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2333     linking step for the pcreposix library.
2335     5. PCRE was failing to diagnose the case of two named groups with the same
2336     name.
2338     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2339     literal character that is needed in the subject for a match, and scans along to
2340     ensure that it is present before embarking on the full matching process. This
2341     saves time in cases of nested unlimited repeats that are never going to match.
2342     Problem: the scan can take a lot of time if the subject is very long (e.g.
2343     megabytes), thus penalizing straightforward matches. It is now done only if the
2344     amount of subject to be scanned is less than 1000 bytes.
2346     7. A lesser problem with the same optimization is that it was recording the
2347     first character of an anchored pattern as "needed", thus provoking a search
2348     right along the subject, even when the first match of the pattern was going to
2349     fail. The "needed" character is now not set for anchored patterns, unless it
2350     follows something in the pattern that is of non-fixed length. Thus, it still
2351     fulfils its original purpose of finding quick non-matches in cases of nested
2352     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2355     Version 4.0 17-Feb-03
2356     ---------------------
2358 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2359     extended to the end of string, PCRE compiled incorrect data. This could lead to
2360     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2362     2. Moved to autoconf 2.53 and libtool 1.4.2.
2364     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2365     the special perltest8 script is no longer needed - all the tests can be run
2366     from a single perltest script.
2368     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2369     by \s. It has now been removed in PCRE. This means it isn't recognized as
2370     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2371     class [:space:] *does* include VT, thereby creating a mess.
2373     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2374     space and tab.
2376     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2377     its new features into the main test script, reducing the number of scripts.
2379     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2380     were backward compatible, and made the (?i) apply to the whole pattern, as if
2381     /i were given. Now it behaves more logically, and applies the option setting
2382     only to what follows. PCRE has been changed to follow suit. However, if it
2383     finds options settings right at the start of the pattern, it extracts them into
2384     the global options, as before. Thus, they show up in the info data.
2386     8. Added support for the \Q...\E escape sequence. Characters in between are
2387     treated as literals. This is slightly different from Perl in that $ and @ are
2388     also handled as literals inside the quotes. In Perl, they will cause variable
2389     interpolation. Note the following examples:
2391     Pattern PCRE matches Perl matches
2393     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2394     \Qabc\$xyz\E abc\$xyz abc\$xyz
2395     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2397     For compatibility with Perl, \Q...\E sequences are recognized inside character
2398     classes as well as outside them.
2400     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2401     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2402     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2403     signed/unsigned warnings.
2405     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2406     option for pcretest, so I've replaced it by a simple function that does just
2407     that job.
2409     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2410     "pcregrep -".
2412     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2413     Java package. This provides some syntactic sugar for simple cases of what my
2414     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2415     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2416     item, you can use this simplified notation. Note that only makes sense with
2417     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2418     greediness, whatever the setting of the PCRE_UNGREEDY option.
2420     13. A change of greediness default within a pattern was not taking effect at
2421     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2422     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2423     was abstracted outside.
2425     14. PCRE now supports the \G assertion. It is true when the current matching
2426     position is at the start point of the match. This differs from \A when the
2427     starting offset is non-zero. Used with the /g option of pcretest (or similar
2428     code), it works in the same way as it does for Perl's /g option. If all
2429     alternatives of a regex begin with \G, the expression is anchored to the start
2430     match position, and the "anchored" flag is set in the compiled expression.
2432     15. Some bugs concerning the handling of certain option changes within patterns
2433     have been fixed. These applied to options other than (?ims). For example,
2434     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2435     been the other way round. Some of this was related to change 7 above.
2437     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2438     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2439     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2440     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2442     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2443     mode. Unlike ".", it always matches newline, whatever the setting of
2444     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2445     assertions. Perl allows it, but it doesn't (in general) work because it can't
2446     calculate the length of the lookbehind. At least, that's the case for Perl
2447     5.8.0 - I've been told they are going to document that it doesn't work in
2448     future.
2450     18. Added an error diagnosis for escapes that PCRE does not support: these are
2451     \L, \l, \N, \P, \p, \U, \u, and \X.
2453     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2454     reading past the end of the pattern in cases such as /[abcd/.
2456     20. PCRE was getting more memory than necessary for patterns with classes that
2457     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2459     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2460     compiling PCRE for use with Virtual Pascal.
2462     22. Small fix to the Makefile to make it work properly if the build is done
2463     outside the source tree.
2465     23. Added a new extension: a condition to go with recursion. If a conditional
2466     subpattern starts with (?(R) the "true" branch is used if recursion has
2467     happened, whereas the "false" branch is used only at the top level.
2469     24. When there was a very long string of literal characters (over 255 bytes
2470     without UTF support, over 250 bytes with UTF support), the computation of how
2471     much memory was required could be incorrect, leading to segfaults or other
2472     strange effects.
2474     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2475     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2476     there was a subsequent back reference to those brackets. This meant that, for
2477     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2478     possible to check for precisely this case. All we can do is abandon the
2479     optimization if .* occurs inside capturing brackets when there are any back
2480     references whatsoever. (See below for a better fix that came later.)
2482     26. The handling of the optimization for finding the first character of a
2483     non-anchored pattern, and for finding a character that is required later in the
2484     match were failing in some cases. This didn't break the matching; it just
2485     failed to optimize when it could. The way this is done has been re-implemented.
2487     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2489     28. Added a new feature that provides some of the functionality that Perl
2490     provides with (?{...}). The facility is termed a "callout". The way it is done
2491     in PCRE is for the caller to provide an optional function, by setting
2492     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2493     global variable. By default it is unset, which disables all calling out. To get
2494     the function called, the regex must include (?C) at appropriate points. This
2495     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2496     This provides a means of identifying different callout points. When PCRE
2497     reaches such a point in the regex, if pcre_callout has been set, the external
2498     function is called. It is provided with data in a structure called
2499     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2500     matching continues; if it returns a non-zero value, the match at the current
2501     point fails. However, backtracking will occur if possible. [This was changed
2502     later and other features added - see item 49 below.]
2504     29. pcretest is upgraded to test the callout functionality. It provides a
2505     callout function that displays information. By default, it shows the start of
2506     the match and the current position in the text. There are some new data escapes
2507     to vary what happens:
2509     \C+ in addition, show current contents of captured substrings
2510     \C- do not supply a callout function
2511     \C!n return 1 when callout number n is reached
2512     \C!n!m return 1 when callout number n is reached for the mth time
2514     30. If pcregrep was called with the -l option and just a single file name, it
2515     output "<stdin>" if a match was found, instead of the file name.
2517     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2518     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2519     pcre_exec(). This saves a malloc/free per call. The default value of
2520     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2521     when configuring.
2523     32. The default maximum size of a compiled pattern is 64K. There have been a
2524     few cases of people hitting this limit. The code now uses macros to handle the
2525     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2526     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2527     configuring. Tests 2 and 5 work only with 2-byte links because they output
2528     debugging information about compiled patterns.
2530     33. Internal code re-arrangements:
2532     (a) Moved the debugging function for printing out a compiled regex into
2533     its own source file (printint.c) and used #include to pull it into
2534     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2535     separate copies.
2537     (b) Defined the list of op-code names for debugging as a macro in
2538     internal.h so that it is next to the definition of the opcodes.
2540     (c) Defined a table of op-code lengths for simpler skipping along compiled
2541     code. This is again a macro in internal.h so that it is next to the
2542     definition of the opcodes.
2544     34. Added support for recursive calls to individual subpatterns, along the
2545     lines of Robin Houston's patch (but implemented somewhat differently).
2547     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2548     allow it to read and process whole directories in Win32. This code was
2549     contributed by Lionel Fourquaux; it has not been tested by me.
2551     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2552     used to name a group. Names consist of alphanumerics and underscores, and must
2553     be unique. Back references use the syntax (?P=name) and recursive calls use
2554     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2555     numbers. The function pcre_fullinfo() can be used after compilation to extract
2556     a name/number map. There are three relevant calls:
2558     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2559     PCRE_INFO_NAMECOUNT yields the number of entries
2560     PCRE_INFO_NAMETABLE yields a pointer to the map.
2562     The map is a vector of fixed-size entries. The size of each entry depends on
2563     the length of the longest name used. The first two bytes of each entry are the
2564     group number, most significant byte first. There follows the corresponding
2565     name, zero terminated. The names are in alphabetical order.
2567     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2568     case instead of 255. Making it the same both with and without UTF-8 support
2569     means that the same test output works with both.
2571     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2572     calling malloc() with a zero argument.
2574     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2575     optimization. I've improved things by keeping a bitmap of backreferences with
2576     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2577     fact referenced, the optimization can be applied. It is unlikely that a
2578     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2579     the match to follow \n) will appear inside brackets with a number greater than
2580     31, but if it does, any back reference > 31 suppresses the optimization.
2582     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2583     of disabling numbered capturing parentheses. Any opening parenthesis that is
2584     not followed by ? behaves as if it were followed by ?: but named parentheses
2585     can still be used for capturing (and they will acquire numbers in the usual
2586     way).
2588     41. Redesigned the return codes from the match() function into yes/no/error so
2589     that errors can be passed back from deep inside the nested calls. A malloc
2590     failure while inside a recursive subpattern call now causes the
2591     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2593     42. It is now possible to set a limit on the number of times the match()
2594     function is called in a call to pcre_exec(). This facility makes it possible to
2595     limit the amount of recursion and backtracking, though not in a directly
2596     obvious way, because the match() function is used in a number of different
2597     circumstances. The count starts from zero for each position in the subject
2598     string (for non-anchored patterns). The default limit is, for compatibility, a
2599     large number, namely 10 000 000. You can change this in two ways:
2601     (a) When configuring PCRE before making, you can use --with-match-limit=n
2602     to set a default value for the compiled library.
2604     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2605     a different value is set. See 45 below.
2607     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2609     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2610     of things that can be changed at compile time. The first argument specifies
2611     what is wanted and the second points to where the information is to be placed.
2612     The current list of available information is:
2616     The output is an integer that is set to one if UTF-8 support is available;
2617     otherwise it is set to zero.
2621     The output is an integer that it set to the value of the code that is used for
2622     newline. It is either LF (10) or CR (13).
2626     The output is an integer that contains the number of bytes used for internal
2627     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2631     The output is an integer that contains the threshold above which the POSIX
2632     interface uses malloc() for output vectors. See item 31 above.
2636     The output is an unsigned integer that contains the default limit of the number
2637     of match() calls in a pcre_exec() execution. See 42 above.
2639     44. pcretest has been upgraded by the addition of the -C option. This causes it
2640     to extract all the available output from the new pcre_config() function, and to
2641     output it. The program then exits immediately.
2643     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2644     order to support additional features. One way would have been to define
2645     pcre_exec2() (for example) with extra arguments, but this would not have been
2646     extensible, and would also have required all calls to the original function to
2647     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2648     is used for passing in "extra" data from pcre_study().
2650     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2651     contains the following fields:
2653     flags a bitmap indicating which of the following fields are set
2654     study_data opaque data from pcre_study()
2655     match_limit a way of specifying a limit on match() calls for a specific
2656     call to pcre_exec()
2657     callout_data data for callouts (see 49 below)
2659     The flag bits are also defined in pcre.h, and are
2665     The pcre_study() function now returns one of these new pcre_extra blocks, with
2666     the actual study data pointed to by the study_data field, and the
2667     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2668     before. That is, this change is entirely upwards-compatible and requires no
2669     change to existing code.
2671     If you want to pass in additional data to pcre_exec(), you can either place it
2672     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2673     block.
2675     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2676     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2677     times with different match limits, until it finds the minimum value needed for
2678     pcre_exec() to complete. The value is then output. This can be instructive; for
2679     most simple matches the number is quite small, but for pathological cases it
2680     gets very large very quickly.
2682     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2683     returns the size of the data block pointed to by the study_data field in a
2684     pcre_extra block, that is, the value that was passed as the argument to
2685     pcre_malloc() when PCRE was getting memory in which to place the information
2686     created by pcre_study(). The fourth argument should point to a size_t variable.
2687     pcretest has been extended so that this information is shown after a successful
2688     pcre_study() call when information about the compiled regex is being displayed.
2690     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2691     because what follows is always an absolute path. (Later: it turns out that this
2692     is more than cosmetic for MinGW, because it doesn't like empty path
2693     components.)
2695     49. Some changes have been made to the callout feature (see 28 above):
2697     (i) A callout function now has three choices for what it returns:
2699     0 => success, carry on matching
2700     > 0 => failure at this point, but backtrack if possible
2701     < 0 => serious error, return this value from pcre_exec()
2703     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2704     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2705     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2706     use by callout functions. It will never be used by PCRE itself.
2708     (ii) The pcre_extra structure (see 45 above) has a void * field called
2709     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2710     pcre_callout_block structure has a field of the same name. The contents of
2711     the field passed in the pcre_extra structure are passed to the callout
2712     function in the corresponding field in the callout block. This makes it
2713     easier to use the same callout-containing regex from multiple threads. For
2714     testing, the pcretest program has a new data escape
2716     \C*n pass the number n (may be negative) as callout_data
2718     If the callout function in pcretest receives a non-zero value as
2719     callout_data, it returns that value.
2721     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2722     there were some redundant $(CFLAGS) in commands that are now specified as
2723     $(LINK), which already includes $(CFLAGS).
2725     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2726     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2727     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2728     one-byte characters throughout. Note that case-insensitive matching applies
2729     only to characters whose values are less than 256. PCRE doesn't support the
2730     notion of cases for higher-valued characters.
2732     (i) A character class whose characters are all within 0-255 is handled as
2733     a bit map, and the map is inverted for negative classes. Previously, a
2734     character > 255 always failed to match such a class; however it should
2735     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2737     (ii) A negated character class with a single character < 255 is coded as
2738     "not this character" (OP_NOT). This wasn't working properly when the test
2739     character was multibyte, either singly or repeated.
2741     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2742     mode, for example: \x{100}{2,3}.
2744     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2745     singly or repeated) now correctly test multibyte characters. However,
2746     PCRE doesn't recognize any characters with values greater than 255 as
2747     digits, spaces, or word characters. Such characters always match \D, \S,
2748     and \W, and never match \d, \s, or \w.
2750     (v) Classes may now contain characters and character ranges with values
2751     greater than 255. For example: [ab\x{100}-\x{400}].
2753     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2754     PCRE in UTF-8 mode.
2756     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2757     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2758     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2759     value.)
2761     53. The single man page has become too large. I have therefore split it up into
2762     a number of separate man pages. These also give rise to individual HTML pages;
2763     these are now put in a separate directory, and there is an index.html page that
2764     lists them all. Some hyperlinking between the pages has been installed.
2766     54. Added convenience functions for handling named capturing parentheses.
2768     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2769     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2770     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2771     are faulted.
2773     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2774     calling configure. These values are used when compiling the dftables.c program
2775     which is run to generate the source of the default character tables. They
2776     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2777     you will need to set these values.
2779     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2782     Version 3.9 02-Jan-02
2783 nigel 61 ---------------------
2785     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2787     2. If --disable-static was given, the building process failed when trying to
2788     build pcretest and pcregrep. (For some reason it was using libtool to compile
2789     them, which is not right, as they aren't part of the library.)
2792 nigel 59 Version 3.8 18-Dec-01
2793     ---------------------
2795     1. The experimental UTF-8 code was completely screwed up. It was packing the
2796     bytes in the wrong order. How dumb can you get?
2799 nigel 57 Version 3.7 29-Oct-01
2800     ---------------------
2802     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2803     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2804     this didn't happen under Solaris 8, where I normally test things.
2806 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2807     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2808     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2809     this fix an hour or so after the initial 3.7 release.)
2810 nigel 57
2811 nigel 59
2812 nigel 55 Version 3.6 23-Oct-01
2813     ---------------------
2815     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2816     offsets passed as NULL with zero offset count.
2818     2. The config.guess and config.sub files had not been updated when I moved to
2819     the latest autoconf.
2822 nigel 53 Version 3.5 15-Aug-01
2823     ---------------------
2824 nigel 5
2825 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2826     had been forgotten.
2828     2. By using declared but undefined structures, we can avoid using "void"
2829     definitions in pcre.h while keeping the internal definitions of the structures
2830     private.
2832     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2833     user point of view, this means that both static and shared libraries are built
2834     by default, but this can be individually controlled. More of the work of
2835     handling this static/shared cases is now inside libtool instead of PCRE's make
2836     file.
2838     4. The pcretest utility is now installed along with pcregrep because it is
2839     useful for users (to test regexs) and by doing this, it automatically gets
2840     relinked by libtool. The documentation has been turned into a man page, so
2841     there are now .1, .txt, and .html versions in /doc.
2843     5. Upgrades to pcregrep:
2844     (i) Added long-form option names like gnu grep.
2845     (ii) Added --help to list all options with an explanatory phrase.
2846     (iii) Added -r, --recursive to recurse into sub-directories.
2847     (iv) Added -f, --file to read patterns from a file.
2849     6. pcre_exec() was referring to its "code" argument before testing that
2850     argument for NULL (and giving an error if it was NULL).
2852     7. Upgraded Makefile.in to allow for compiling in a different directory from
2853     the source directory.
2855     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2856     options bits, the pointer it was passed was to an int instead of to an unsigned
2857     long int. This mattered only on 64-bit systems.
2859     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2860     generated) instead of pcre.in, which it its source. Also made the same change
2861     in several of the .c files.
2863     10. A new release of gcc defines printf() as a macro, which broke pcretest
2864     because it had an ifdef in the middle of a string argument for printf(). Fixed
2865     by using separate calls to printf().
2867     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2868     script, to force use of CR or LF instead of \n in the source. On non-Unix
2869     systems, the value can be set in config.h.
2871     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2872     absolute limit. Changed the text of the error message to make this clear, and
2873     likewise updated the man page.
2875     13. The limit of 99 on the number of capturing subpatterns has been removed.
2876     The new limit is 65535, which I hope will not be a "real" limit.
2879 nigel 51 Version 3.4 22-Aug-00
2880     ---------------------
2882     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2884     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2887 nigel 49 Version 3.3 01-Aug-00
2888     ---------------------
2890     1. If an octal character was given, but the value was greater than \377, it
2891     was not getting masked to the least significant bits, as documented. This could
2892     lead to crashes in some systems.
2894     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2895     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2897     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2898     These just pass their arguments on to (pcre_free)(), but they are provided
2899     because some uses of PCRE bind it to non-C systems that can call its functions,
2900     but cannot call free() or pcre_free() directly.
2902     4. Add "make test" as a synonym for "make check". Corrected some comments in
2903     the Makefile.
2905     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2906     Makefile.
2908     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2909     command called pgrep for grepping around the active processes.
2911     7. Added the beginnings of support for UTF-8 character strings.
2913     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2914     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2915     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2916     out for the ar command.)
2919 nigel 47 Version 3.2 12-May-00
2920     ---------------------
2922     This is purely a bug fixing release.
2924     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2925     of ZA. This was just one example of several cases that could provoke this bug,
2926     which was introduced by change 9 of version 2.00. The code for breaking
2927     infinite loops after an iteration that matches an empty string was't working
2928     correctly.
2930     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2931     when matched against abbab (for example). After matching an empty string, it
2932     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2933     caused it to match further down the string than it should.
2935     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2936     was there because it doesn't seem to be needed, and it causes trouble on some
2937     systems, as it is not a Standard C header. It has been removed.
2939     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2940     were reported on the Macintosh. The changes were from
2942     while ((c = *(++ptr)) != 0 && c != '\n');
2943     to
2944     while ((c = *(++ptr)) != 0 && c != '\n') ;
2946     Totally extraordinary, but if that's what it takes...
2948     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2949     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2950     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2951     assumes the way PCRE uses memmove() (always moving upwards).
2953     6. PCRE is being used in one environment where strchr() is not available. There
2954     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2955     faster code anyway.
2958 nigel 45 Version 3.1 09-Feb-00
2959     ---------------------
2961     The only change in this release is the fixing of some bugs in Makefile.in for
2962     the "install" target:
2964     (1) It was failing to install pcreposix.h.
2966     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2969 nigel 43 Version 3.0 01-Feb-00
2970     ---------------------
2971 nigel 41
2972     1. Add support for the /+ modifier to perltest (to output $` like it does in
2973     pcretest).
2975     2. Add support for the /g modifier to perltest.
2977     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2978     matches null strings.
2980     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2981     pattern. Perl treats empty patterns specially - it reuses the most recent
2982     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2983     effect.
2985     5. The POSIX interface was broken in that it was just handing over the POSIX
2986     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2987     required a bigger vector, with some working space on the end. This means that
2988     the POSIX wrapper now has to get and free some memory, and copy the results.
2990 nigel 43 6. Added some simple autoconf support, placing the test data and the
2991     documentation in separate directories, re-organizing some of the
2992     information files, and making it build pcre-config (a GNU standard). Also added
2993     libtool support for building PCRE as a shared library, which is now the
2994     default.
2995 nigel 41
2996 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2997     09 are not valid octal constants. Single digits will be used for minor values
2998     less than 10.
3000     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3001     existing programs that set these in the POSIX interface can use PCRE without
3002     modification.
3004     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3005     return all that pcre_info() returns, plus additional data. The pcre_info()
3006     function is retained for compatibility, but is considered to be obsolete.
3008     10. Added experimental recursion feature (?R) to handle one common case that
3009     Perl 5.6 will be able to do with (?p{...}).
3011     11. Added support for POSIX character classes like [:alpha:], which Perl is
3012     adopting.
3015 nigel 39 Version 2.08 31-Aug-99
3016     ----------------------
3018     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3019     trying to match at the startoffset position, but instead was moving forward to
3020     the next newline as if a previous match had failed.
3022     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3023     and could get into a loop if a null string was matched other than at the start
3024     of the subject.
3026     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3027     be distinguished at compile time, and for completeness also added PCRE_DATE.
3029     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3030     in GnuWin32 environments.
3033 nigel 37 Version 2.07 29-Jul-99
3034     ----------------------
3036     1. The documentation is now supplied in plain text form and HTML as well as in
3037     the form of man page sources.
3039     2. C++ compilers don't like assigning (void *) values to other pointer types.
3040     In particular this affects malloc(). Although there is no problem in Standard
3041     C, I've put in casts to keep C++ compilers happy.
3043     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3044     should be (const char *).
3046     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3047     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3048     However, I haven't made this a standard facility. The documentation doesn't
3049     mention it, and the Makefile doesn't support it.
3051     5. The Makefile now contains an "install" target, with editable destinations at
3052     the top of the file. The pcretest program is not installed.
3054     6. pgrep -V now gives the PCRE version number and date.
3056     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3057     causing the entire string to be ignored, instead of just the last character.
3059     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3060     non-matching string, it can take a very, very long time, even for strings of
3061     quite modest length, because of the nested recursion. PCRE now does better in
3062     some of these cases. It does this by remembering the last required literal
3063     character in the pattern, and pre-searching the subject to ensure it is present
3064     before running the real match. In other words, it applies a heuristic to detect
3065     some types of certain failure quickly, and in the above example, if presented
3066     with a string that has no trailing " it gives "no match" very quickly.
3068     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3069     other alternatives are tried instead.
3072 nigel 35 Version 2.06 09-Jun-99
3073     ----------------------
3075     1. Change pcretest's output for amount of store used to show just the code
3076     space, because the remainder (the data block) varies in size between 32-bit and
3077     64-bit systems.
3079     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3080     start matching at. This allows lookbehinds to work when searching for multiple
3081     occurrences in a string.
3083     3. Added additional options to pcretest for testing multiple occurrences:
3085     /+ outputs the rest of the string that follows a match
3086     /g loops for multiple occurrences, using the new startoffset argument
3087     /G loops for multiple occurrences by passing an incremented pointer
3089     4. PCRE wasn't doing the "first character" optimization for patterns starting
3090     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3091     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3092     the letter 'x'. On long subject strings, this gives a significant speed-up.
3095 nigel 33 Version 2.05 21-Apr-99
3096     ----------------------
3098     1. Changed the type of magic_number from int to long int so that it works
3099     properly on 16-bit systems.
3101     2. Fixed a bug which caused patterns starting with .* not to work correctly
3102     when the subject string contained newline characters. PCRE was assuming
3103     anchoring for such patterns in all cases, which is not correct because .* will
3104     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3105     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3106     must be retried after every newline in the subject.
3109 nigel 31 Version 2.04 18-Feb-99
3110     ----------------------
3112     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3113     computation of the store needed to hold the pattern was incorrect (too large).
3114     If such patterns were nested a few deep, this could multiply and become a real
3115     problem.
3117     2. Added /M option to pcretest to show the memory requirement of a specific
3118     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3120     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3121     compiled in such a way that the backtracking after subsequent failure was
3122     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3123     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3126 nigel 29 Version 2.03 02-Feb-99
3127     ----------------------
3129     1. Fixed typo and small mistake in man page.
3131 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3132     LICENCE file containing the conditions.
3133 nigel 29
3134     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3135     Perl, that is the internal \ allows the delimiter to be included in the
3136     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3137     the final delimiter, add \ to the end of the pattern (to test the error).
3139     4. Added the convenience functions for extracting substrings after a successful
3140     match. Updated pcretest to make it able to test these functions.
3143 nigel 27 Version 2.02 14-Jan-99
3144     ----------------------
3146     1. Initialized the working variables associated with each extraction so that
3147     their saving and restoring doesn't refer to uninitialized store.
3149     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3150     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3151     fix the problem.
3153     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3154     calls, and wasn't printing the correct value for compiling calls. Increased the
3155     default value of LOOPREPEAT, and the number of significant figures in the
3156     times.
3158     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3160     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3161     a building problem on Windows NT with a FAT file system.
3164 nigel 25 Version 2.01 21-Oct-98
3165     ----------------------
3167     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3168     to character tables built by pcre_maketables() in the current locale. If NULL
3169     is passed, the default tables are used.
3172 nigel 23 Version 2.00 24-Sep-98
3173 nigel 21 ----------------------
3175 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3176     it any more.
3178     2. Allow quantification of (?>) groups, and make it work correctly.
3180     3. The first character computation wasn't working for (?>) groups.
3182     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3183     end of the subject) and add 5.005's \z, which really does match only at the
3184     very end of the subject.
3186     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3188     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3189     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3190     localized options. All options to pcre_study() were also removed.
3192     7. Add other new features from 5.005:
3194     $(?<= positive lookbehind
3195     $(?<! negative lookbehind
3196     (?imsx-imsx) added the unsetting capability
3197     such a setting is global if at outer level; local otherwise
3198     (?imsx-imsx:) non-capturing groups with option setting
3199     (?(cond)re|re) conditional pattern matching
3201     A backreference to itself in a repeated group matches the previous
3202     captured string.
3204     8. General tidying up of studying (both automatic and via "study")
3205     consequential on the addition of new assertions.
3207     9. As in 5.005, unlimited repeated groups that could match an empty substring
3208     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3209     runtime if any iteration does actually match an empty substring.
3211     10. Include the RunTest script in the distribution.
3213     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3214     discrepancies, some of which were old and were also with respect to 5.004. They
3215     have now been fixed.
3218     Version 1.09 28-Apr-98
3219     ----------------------
3221 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3222     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3223     program crashes, or just wrong answers. This did not apply to negated classes
3224     containing more than one character, or to minima other than one.
3227 nigel 19 Version 1.08 27-Mar-98
3228     ----------------------
3230     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3232     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3233     latter must appear before anything that relies on it in the pattern.
3236 nigel 17 Version 1.07 16-Feb-98
3237     ----------------------
3239     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3240     repeat of a potentially empty string).
3243 nigel 15 Version 1.06 23-Jan-98
3244     ----------------------
3246     1. Added Markus Oberhumer's little patches for C++.
3248     2. Literal strings longer than 255 characters were broken.
3251 nigel 13 Version 1.05 23-Dec-97
3252     ----------------------
3254     1. Negated character classes containing more than one character were failing if
3255     PCRE_CASELESS was set at run time.
3258 nigel 11 Version 1.04 19-Dec-97
3259     ----------------------
3261     1. Corrected the man page, where some "const" qualifiers had been omitted.
3263     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3264     input syntax.
3266     3. Fixed memory leak which occurred when a regex with back references was
3267     matched with an offsets vector that wasn't big enough. The temporary memory
3268     that is used in this case wasn't being freed if the match failed.
3270     4. Tidied pcretest to ensure it frees memory that it gets.
3272     5. Temporary memory was being obtained in the case where the passed offsets
3273     vector was exactly big enough.
3275     6. Corrected definition of offsetof() from change 5 below.
3277     7. I had screwed up change 6 below and broken the rules for the use of
3278     setjmp(). Now fixed.
3281 nigel 9 Version 1.03 18-Dec-97
3282     ----------------------
3284     1. A erroneous regex with a missing opening parenthesis was correctly
3285     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3286     on some systems.
3288     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3289     it was reported that one broken compiler failed on the former because "code" is
3290     also an independent variable.
3292     3. The erroneous regex a[]b caused an array overrun reference.
3294     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3295     fail on data ending with that character. (It was going on too far, and checking
3296     the next character, typically a binary zero.) This was specific to the
3297     optimized code for single-character negative classes.
3299     5. Added a contributed patch from the TIN world which does the following:
3301     + Add an undef for memmove, in case the the system defines a macro for it.
3303     + Add a definition of offsetof(), in case there isn't one. (I don't know
3304     the reason behind this - offsetof() is part of the ANSI standard - but
3305     it does no harm).
3307     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3308     most of the places where whitespace preceded '#'. I have given up and
3309     allowed the remaining 2 cases to be at the margin.
3311     + Rename some variables in pcre to eliminate shadowing. This seems very
3312     pedantic, but does no harm, of course.
3314     6. Moved the call to setjmp() into its own function, to get rid of warnings
3315     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3317     7. Constructs such as \d{8,} were compiling into the equivalent of
3318 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3319 nigel 9 outcome, but in this particular case used more store than had been allocated,
3320     which caused the bug to be discovered because it threw up an internal error.
3322     8. The debugging code in both pcre and pcretest for outputting the compiled
3323     form of a regex was going wrong in the case of back references followed by
3324     curly-bracketed repeats.
3327 nigel 7 Version 1.02 12-Dec-97
3328     ----------------------
3330     1. Typos in pcre.3 and comments in the source fixed.
3332     2. Applied a contributed patch to get rid of places where it used to remove
3333     'const' from variables, and fixed some signed/unsigned and uninitialized
3334     variable warnings.
3336     3. Added the "runtest" target to Makefile.
3338     4. Set default compiler flag to -O2 rather than just -O.
3341 nigel 5 Version 1.01 19-Nov-97
3342     ----------------------
3344     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3345     like /([ab]*)*/, that is, for classes with more than one character in them.
3347     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3348     as /((?>a*))*/ (a PCRE_EXTRA facility).
3351     Version 1.00 18-Nov-97
3352     ----------------------
3354     1. Added compile-time macros to support systems such as SunOS4 which don't have
3355     memmove() or strerror() but have other things that can be used instead.
3357     2. Arranged that "make clean" removes the executables.
3360 nigel 3 Version 0.99 27-Oct-97
3361     ----------------------
3363     1. Fixed bug in code for optimizing classes with only one character. It was
3364     initializing a 32-byte map regardless, which could cause it to run off the end
3365     of the memory it had got.
3367     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3370     Version 0.98 22-Oct-97
3371     ----------------------
3373     1. Fixed bug in code for handling temporary memory usage when there are more
3374     back references than supplied space in the ovector. This could cause segfaults.
3377     Version 0.97 21-Oct-97
3378     ----------------------
3380     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3382     2. Optimized negated single characters not to use a bit map.
3384     3. Brought error texts together as macro definitions; clarified some of them;
3385     fixed one that was wrong - it said "range out of order" when it meant "invalid
3386     escape sequence".
3388     4. Changed some char * arguments to const char *.
3390     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3392     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3393     pcretest.
3396     Version 0.96 16-Oct-97
3397     ----------------------
3399     1. Added a simple "pgrep" utility to the distribution.
3401     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3402     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3403     where "ddd" means "one or more decimal digits".
3405     3. Fixed serious bug. If a pattern had a back reference, but the call to
3406     pcre_exec() didn't supply a large enough ovector to record the related
3407     identifying subpattern, the match always failed. PCRE now remembers the number
3408     of the largest back reference, and gets some temporary memory in which to save
3409     the offsets during matching if necessary, in order to ensure that
3410     backreferences always work.
3412     4. Increased the compatibility with Perl in a number of ways:
3414     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3415     to request this handling. The option can be set at compile or exec time.
3417     (b) $ matches before a terminating newline by default; an option
3418     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3419     mode). The option can be set at compile or exec time.
3421     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3422     the same as Perl's. If the decimal number it represents is less than 10
3423     or there aren't that many previous left capturing parentheses, an octal
3424     escape is read. Inside a character class, it's always an octal escape,
3425     even if it is a single digit.
3427     (d) An escaped but undefined alphabetic character is taken as a literal,
3428     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3429     escapes.
3431     (e) {0} is now permitted. (The previous item is removed from the compiled
3432     pattern).
3434     5. Changed all the names of code files so that the basic parts are no longer
3435     than 10 characters, and abolished the teeny "globals.c" file.
3437     6. Changed the handling of character classes; they are now done with a 32-byte
3438     bit map always.
3440     7. Added the -d and /D options to pcretest to make it possible to look at the
3441     internals of compilation without having to recompile pcre.
3444     Version 0.95 23-Sep-97
3445     ----------------------
3447     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3448     \x20 at the start of a run of normal characters. These were being treated as
3449     real characters, instead of the source characters being re-checked.
3452     Version 0.94 18-Sep-97
3453     ----------------------
3455     1. The functions are now thread-safe, with the caveat that the global variables
3456     containing pointers to malloc() and free() or alternative functions are the
3457     same for all threads.
3459     2. Get pcre_study() to generate a bitmap of initial characters for non-
3460     anchored patterns when this is possible, and use it if passed to pcre_exec().
3463     Version 0.93 15-Sep-97
3464     ----------------------
3466     1. /(b)|(:+)/ was computing an incorrect first character.
3468     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3469     but not actually doing anything yet.
3471     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3472     as Perl does (e.g. [-az] or [az-]).
3474     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3475     all possible positions.
3477     5. Split up into different modules to avoid including unneeded functions in a
3478     compiled binary. However, compile and exec are still in one module. The "study"
3479     function is split off.
3481     6. The character tables are now in a separate module whose source is generated
3482     by an auxiliary program - but can then be edited by hand if required. There are
3483     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3484     toupper() in the code.
3486     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3487     make them global. Abolish the function for setting them, as the caller can now
3488     set them directly.
3491     Version 0.92 11-Sep-97
3492     ----------------------
3494     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3495     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3497     2. Caseless matching was not working in character classes if the characters in
3498     the pattern were in upper case.
3500     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3502     4. Make PCRE_ANCHORED public and accept as a compile option.
3504     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3505     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3506     pass them.
3508     6. Give an error if bad option bits passed at compile or run time.
3510     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3511     pcretest to cause it to pass that flag.
3513     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3514     options, and the first character, if set.
3516     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3519     Version 0.91 10-Sep-97
3520     ----------------------
3522     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3523     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3525     2. PCRE was looping on encountering an indefinitely repeated back reference to
3526     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3527     Perl does - treats the match as successful.
3529     ****


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