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Revision 421 - (hide annotations) (download)
Fri Aug 14 15:43:27 2009 UTC (5 years, 8 months ago) by ph10
File size: 166863 byte(s)
Fix --fixed-strings.

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8     was out-of-date, and there was no check on the pcre_compile() error code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 421 4. The long form of the pcregrep -F option was incorrectly implemented as
25     --fixed_strings instead of --fixed-strings. This is an incompatible change,
26     but it seems right to fix it, and I didn't think it was worth preserving
27     the old behaviour.
29 ph10 418
30 ph10 412 Version 7.9 11-Apr-09
31 ph10 376 ---------------------
33 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
34 ph10 376 (pcretest), all targets were linked against these libraries. This included
35     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
36     libraries. This caused unwanted dependencies to be created. This problem
37 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
38 ph10 376 pcretest is linked with readline.
39 ph10 392
40 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
41     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
42     moved outside it again, because FALSE and TRUE are already defined in AIX,
43     but BOOL is not.
44 ph10 392
45     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
46 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
47 ph10 392
48 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
49     hyphens) following file names and line numbers when outputting matching
50 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
51 ph10 376 wording for the --colour (or --color) option.
52 ph10 392
53 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
54     was not coloured; this is different to GNU grep, so I have changed it to be
55     the same.
56 ph10 392
57 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
58 ph10 392 each matching line was coloured. Now it goes on to look for further matches
59     of any of the test patterns, which is the same behaviour as GNU grep.
61     7. A pattern that could match an empty string could cause pcregrep to loop; it
62     doesn't make sense to accept an empty string match in pcregrep, so I have
63 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
64     seems to be how GNU grep behaves.
65 ph10 392
66 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
67 ph10 392 start or after a newline", because the conditional assertion was not being
68     correctly handled. The rule now is that both the assertion and what follows
69     in the first alternative must satisfy the test.
71 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
72 ph10 399 condition was an assertion, PCRE could crash during matching, both with
73     pcre_exec() and pcre_dfa_exec().
74 ph10 392
75     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
76     used for matching.
78     11. Unicode property support in character classes was not working for
79 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
80 ph10 388
81 ph10 392 12. Added the -M command line option to pcretest.
83 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
84 ph10 389
85     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
86 ph10 390
87 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
88 ph10 390 wrapper.
89 ph10 392
90 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
91 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
92 ph10 391 string constants.
93 ph10 405
94 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
95     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
96 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
97     these, but not everybody uses configure.
99     19. A conditional group that had only one branch was not being correctly
100     recognized as an item that could match an empty string. This meant that an
101     enclosing group might also not be so recognized, causing infinite looping
102     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
103     with the subject "ab", where knowledge that the repeated group can match
104 ph10 396 nothing is needed in order to break the loop.
105 ph10 405
106 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
107 ph10 405 exec(), but without supplying a callout function, matching went wrong.
109     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
110     leak if the size of the offset vector was greater than 30. When the vector
111     is smaller, the saved offsets during recursion go onto a local stack
112     vector, but for larger vectors malloc() is used. It was failing to free
113     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
114 ph10 400 error, in fact).
115 ph10 405
116 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
117 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
118     problem, but was untidy.
119 ph10 376
120 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
121     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
122     included within another project.
123 ph10 411
124 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
125     slightly modified by me:
126 ph10 411
127     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
128     not building pcregrep.
130 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
131 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
133 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
134     duplicate group numbers, could behave incorrectly or give incorrect errors,
135     because when scanning forward to find the reference group, PCRE was not
136     taking into account the duplicate group numbers. A pattern such as
137     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
138 ph10 411
139     26. Changed a few more instances of "const unsigned char *" to USPTR, making
140     the feature of a custom pointer more persuasive (as requested by a user).
141 ph10 416
142 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
143 ph10 416 pcretest.c, inside #ifndefs, because it seems they are sometimes already
144     pre-defined.
145 ph10 392
146 ph10 416 28. Added support for (*UTF8) at the start of a pattern.
148 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
149     in the configuration summary.
150 ph10 405
151 ph10 411
152 ph10 374 Version 7.8 05-Sep-08
153 ph10 349 ---------------------
155     1. Replaced UCP searching code with optimized version as implemented for Ad
156     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
157 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
158     to 5 times on some simple patterns that I tested. Permission was given to
159     distribute the MultiStage2.py script that generates the tables (it's not in
160     the tarball, but is in the Subversion repository).
161 ph10 349
162 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
163     scripts.
164 ph10 358
165 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
166     a group with a zero qualifier. The result of the study could be incorrect,
167 ph10 358 or the function might crash, depending on the pattern.
169     4. Caseless matching was not working for non-ASCII characters in back
170 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
171 ph10 358 It now works when Unicode Property Support is available.
173 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
174     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
175     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
176 ph10 358 truncation.
177 ph10 349
178 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
180 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
181     pointers, in case they are 64-bit values.
182 ph10 371
183     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
184     test 2 if it fails.
186 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
187 ph10 371 and a #define of that name to empty if it is not externally set. This is to
188     allow users of MSVC to set it if necessary.
190     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
191 ph10 359 the convenience functions in the pcre_get.c source file.
192 ph10 371
193 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
194     could cause overwriting and/or a crash. This command provoked a crash in
195 ph10 371 some environments:
197     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
199 ph10 360 This potential security problem was recorded as CVE-2008-2371.
200 ph10 371
201 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
202     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
203 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
204 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
205     pcretest so that it places the subject at the end of its malloc-ed buffer.
206 ph10 371
207 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
208 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
210 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
211 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
212     first line. This applied both to normal and DFA matching.
214 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
215 ph10 371 /^[^d]*?$/8 failed to match "abc".
216 ph10 351
217 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
219     17. Make it more clear in the documentation that values returned from
220 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
221 ph10 357
222 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
223 ph10 368
224 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
225     supplied by Stefan Weber. I made a further small update for 7.8 because
226 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
227     replaced by pcre_ucd.c.
228 ph10 371
229 ph10 373
230 ph10 347 Version 7.7 07-May-08
231 ph10 321 ---------------------
233     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
234 ph10 345 a string to a long long, pretend we don't even have a long long." This is
235 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
236 ph10 345
237 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
238     pre-7.6 versions, which defined a global no_arg variable instead of putting
239 ph10 332 it in the RE class. (See also #8 below.)
240 ph10 345
241     3. Remove a line of dead code, identified by coverity and reported by Nuno
242     Lopes.
244 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
245 ph10 321
246 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
247 ph10 345 of files, instead of just to the final components.
249 ph10 324 (2) If there was more than one level of directory, the subdirectories were
250     skipped unless they satisfied the include/exclude conditions. This is
251     inconsistent with GNU grep (and could even be seen as contrary to the
252     pcregrep specification - which I improved to make it absolutely clear).
253     The action now is always to scan all levels of directory, and just
254     apply the include/exclude patterns to regular files.
255 ph10 345
256 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
257 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
259 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
260 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
261 ph10 326 doesn't support NULs in patterns.
262 ph10 345
263     7. Added some missing "const"s to declarations of static tables in
264     pcre_compile.c and pcre_dfa_exec.c.
266 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
267 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
268 ph10 345 first patch. And a third patch - this was a messy problem.)
269 ph10 321
270 ph10 345 9. Applied Craig's patch to remove the use of push_back().
272 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
273     matching function regexec().
274 ph10 345
275     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
276     which, however, unlike Perl's \g{...}, are subroutine calls, not back
277 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
278     Oniguruma does).
279 ph10 345
280     12. Previously, a group with a zero repeat such as (...){0} was completely
281 ph10 335 omitted from the compiled regex. However, this means that if the group
282     was called as a subroutine from elsewhere in the pattern, things went wrong
283 ph10 345 (an internal error was given). Such groups are now left in the compiled
284     pattern, with a new opcode that causes them to be skipped at execution
285 ph10 335 time.
286 ph10 345
287 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
288     to the way PCRE behaves:
289 ph10 345
290 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
291 ph10 345
292     (b) A back reference to an unmatched subpattern matches an empty string
293 ph10 336 (Perl fails the current match path).
294 ph10 345
295 ph10 341 (c) A data ] in a character class must be notated as \] because if the
296 ph10 345 first data character in a class is ], it defines an empty class. (In
297 ph10 341 Perl it is not possible to have an empty class.) The empty class []
298     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
299     The negative empty class [^] matches any one character, independently
300     of the DOTALL setting.
301 ph10 345
302     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
303 ph10 340 non-existent subpattern following a character class starting with ']' and
304     containing () gave an internal compiling error instead of "reference to
305     non-existent subpattern". Fortunately, when the pattern did exist, the
306 ph10 345 compiled code was correct. (When scanning forwards to check for the
307 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
308 ph10 345 the class, so got the count wrong. When actually compiling, the reference
309 ph10 340 was subsequently set up correctly.)
310 ph10 345
311 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
312 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
313     other assertions are supported. I have made pcre_dfa_exec() support
314     (*FAIL).
316 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
317 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
318     cannot be changed at match time, I realized I could make a small
319     improvement to matching performance by compiling OP_ALLANY instead of
320     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
321     on the OP_ANY path.
323     17. Compiling pcretest on Windows with readline support failed without the
324 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
325 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
327 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
328 ph10 345 ncurses library to be included for pcretest when ReadLine support is
329     requested, but also to allow for it to be overridden. This patch came from
330     Daniel Bergström.
331 ph10 347
332 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
333 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
334     any errors with the current Unicode tables. Thanks to Peter Kankowski for
335     spotting this.
336 ph10 324
337 ph10 332
338 ph10 319 Version 7.6 28-Jan-08
339 ph10 300 ---------------------
341 ph10 302 1. A character class containing a very large number of characters with
342     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
343     overflow.
344 ph10 309
345     2. Patch to cut out the "long long" test in pcrecpp_unittest when
346     HAVE_LONG_LONG is not defined.
348 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
349 ph10 304 bring them up to date and include new features. This patch includes:
350 ph10 309
351 ph10 304 - Fixed PH's badly added libz and libbz2 support.
352     - Fixed a problem with static linking.
353 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
354 ph10 304 - Fixed dftables problem and added an option.
355     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
357     - Added readline support for pcretest.
358 ph10 309 - Added an listing of the option settings after cmake has run.
360 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
361     "pcre.dll" under mingw when using Configure/Make. I added stuff to
362     Makefile.am that cause it to include this special target, without
363     affecting anything else. Note that the same mingw target plus all
364     the other distribution libraries and programs are now supported
365     when configuring with CMake (see 6 below) instead of with
366     Configure/Make.
367 ph10 309
368 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
369     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
370 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
371     solves the problem, but it does no harm.
372 ph10 313
373 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
374 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
375 ph10 314 with CMake, and also correct the comment about stack recursion.
376 ph10 313
377 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
378 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
379     of a program that users should build themselves after PCRE is installed, so
380     building it automatically is not really right. What is more, it gave
381 ph10 312 trouble in some build environments.
382 ph10 300
383 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
384 ph10 308
385 ph10 319
386 ph10 298 Version 7.5 10-Jan-08
387 ph10 263 ---------------------
389     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
390     values in parens when parsing an RE using the C++ wrapper."
391 ph10 286
392 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
393     Characters greater than 255 were excluded from the class instead of being
394     included.
395 ph10 286
396     3. The same bug as (2) above applied to negated POSIX classes such as
397 ph10 265 [:^space:].
398 ph10 286
399 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
400     defined or documented. It seems to have been a typo for PCRE_STATIC, so
401 ph10 286 I have changed it.
403 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
404 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
405     first named subpattern whose name started with "a" (in other words, the
406 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
407     expected" is now given for (?&) (a zero-length name), and this patch also
408     makes it give the same error for \k'' (previously it complained that that
409     was a reference to a non-existent subpattern).
410 ph10 286
411 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
412 ph10 286 this is right because (?- can be followed by option settings as well as by
413 ph10 269 digits. I have, however, made the messages clearer.
414 ph10 286
415 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
416     than the number used in the conditional) now cause a compile-time error.
417     This is actually not compatible with Perl, which accepts such patterns, but
418     treats the conditional as always being FALSE (as PCRE used to), but it
419     seems to me that giving a diagnostic is better.
420 ph10 286
421 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
422 ph10 275 and messages.
423 ph10 286
424     9. Fix two occurrences of "backslash" in comments that should have been
425     "backspace".
427     10. Remove two redundant lines of code that can never be obeyed (their function
428     was moved elsewhere).
430     11. The program that makes PCRE's Unicode character property table had a bug
431     which caused it to generate incorrect table entries for sequences of
432 ph10 277 characters that have the same character type, but are in different scripts.
433 ph10 286 It amalgamated them into a single range, with the script of the first of
434 ph10 277 them. In other words, some characters were in the wrong script. There were
435     thirteen such cases, affecting characters in the following ranges:
436 ph10 286
437 ph10 277 U+002b0 - U+002c1
438     U+0060c - U+0060d
439 ph10 286 U+0061e - U+00612
440 ph10 277 U+0064b - U+0065e
441     U+0074d - U+0076d
442     U+01800 - U+01805
443     U+01d00 - U+01d77
444     U+01d9b - U+01dbf
445     U+0200b - U+0200f
446     U+030fc - U+030fe
447     U+03260 - U+0327f
448     U+0fb46 - U+0fbb1
449     U+10450 - U+1049d
450 ph10 286
451 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
452     compatible with GNU grep in that, if there was more than one match in a
453     line, it showed only the first of them. It now behaves in the same way as
454     GNU grep.
455 ph10 286
456     13. If the -o and -v options were combined for pcregrep, it printed a blank
457     line for every non-matching line. GNU grep prints nothing, and pcregrep now
458     does the same. The return code can be used to tell if there were any
459     non-matching lines.
461 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
463     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
464 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
465 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
466     and both kinds of lookbehind were skipped).
468 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
469 ph10 284 inclusion of <windows.h> to before rather than after the definition of
470     INVALID_FILE_ATTRIBUTES (patch from David Byron).
471 ph10 263
472 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
473 ph10 286 character property caused pcre_compile() to compile bad code, which led at
474     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
475     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
476     caused the error; without that there was no problem.
477 ph10 263
478 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
479 ph10 286
480 ph10 289 19. Added --enable-pcretest-libreadline.
481 ph10 286
482 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
483 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
484 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
485     later patch that removed the other one (the right fix) and added unit tests
486     that check the return values (which was not done before).
487 ph10 292
488 ph10 291 21. Several CMake things:
489 ph10 287
490 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
491 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
492 ph10 288
493 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
494     linked with the newly-built libraries, not previously installed ones.
495 ph10 291
497 ph10 298
498     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
499     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
500     UTF-8 newline character). The key issue is that the pattern starts .*;
501     this means that the match must be either at the beginning, or after a
502     newline. The bug was in the code for advancing after a failed match and
503     checking that the new position followed a newline. It was not taking
504 ph10 294 account of UTF-8 characters correctly.
505 ph10 298
506     23. PCRE was behaving differently from Perl in the way it recognized POSIX
507     character classes. PCRE was not treating the sequence [:...:] as a
508     character class unless the ... were all letters. Perl, however, seems to
509     allow any characters between [: and :], though of course it rejects as
510     unknown any "names" that contain non-letters, because all the known class
511     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
512     for example, whereas PCRE did not - it did not recognize a POSIX character
513     class. This seemed a bit dangerous, so the code has been changed to be
514     closer to Perl. The behaviour is not identical to Perl, because PCRE will
515     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
516     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
517     Perl does, and where it didn't before.
519 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
520     Windows environments %n is disabled by default.
521 ph10 292
523 ph10 260 Version 7.4 21-Sep-07
524 ph10 230 ---------------------
526     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
527 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
528     LF". That isn't really right - the whole point of the change was to try to
529     help when there was an actual mention of one of the two characters. So now
530     the change happens only if \r or \n (or a literal CR or LF) character is
531 ph10 230 encountered.
532 ph10 231
533     2. The 32-bit options word was also used for 6 internal flags, but the numbers
534     of both had grown to the point where there were only 3 bits left.
535     Fortunately, there was spare space in the data structure, and so I have
536     moved the internal flags into a new 16-bit field to free up more option
537 ph10 230 bits.
538 ph10 231
539     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
540     but did not set the internal JCHANGED flag - either of these is enough to
541     control the way the "get" function works - but the PCRE_INFO_JCHANGED
542     facility is supposed to tell if (?J) was ever used, so now (?J) at the
543 ph10 230 start sets both bits.
545 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
546     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
547 ph10 230
548 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
550     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
551 ph10 233 compatibility, even though it is no longer used.
552 ph10 243
553     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
554 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
555 ph10 259 windows.h file is present (where different names are used). [This was
556 ph10 257 reversed later after testing - see 16 below.]
557 ph10 243
558     8. Changed all #include <config.h> to #include "config.h". There were also
559 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
560 ph10 243
561 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
562 ph10 243 sequence off the lines that it output.
564     10. It was pointed out to me that arrays of string pointers cause lots of
565     relocations when a shared library is dynamically loaded. A technique of
566     using a single long string with a table of offsets can drastically reduce
567     these. I have refactored PCRE in four places to do this. The result is
568 ph10 240 dramatic:
569 ph10 243
570 ph10 240 Originally: 290
571     After changing UCP table: 187
572 ph10 243 After changing error message table: 43
573 ph10 240 After changing table of "verbs" 36
574     After changing table of Posix names 22
575 ph10 243
576 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
577 ph10 247
578 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
579 ph10 247 unicode-properties was also set.
581 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
582 ph10 231
583 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
584     checked only for CRLF.
585 ph10 233
586 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
588 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
589 ph10 253
590 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
591 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
592     entirely. This removes changes made in 7 above.
593 ph10 256
594 ph10 261 17. The CMake files have been updated, and there is now more information about
595     building with CMake in the NON-UNIX-USE document.
596 ph10 257
597 ph10 261
598 ph10 228 Version 7.3 28-Aug-07
599 ph10 157 ---------------------
601 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
602     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
603     brackets there is not right, since it causes compilers to look for an
604     installed pcre.h, not the version that is in the source that is being
605     compiled (which of course may be different). I have changed it back to:
606 ph10 197
607 ph10 189 #include "pcre.h"
608 ph10 197
609     I have a vague recollection that the change was concerned with compiling in
610     different directories, but in the new build system, that is taken care of
611     by the VPATH setting the Makefile.
613 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
614     when the subject happened to end in the byte 0x85 (e.g. if the last
615     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
616     characters but of course it shouldn't be taken as a newline when it is part
617     of another character. The bug was that, for an unlimited repeat of . in
618     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
619     characters when looking for a newline.
620 ph10 197
621     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
623     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
624     in debug output.
626 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
627     long printing in the pcrecpp unittest when running under MinGW.
628 ph10 189
629 ph10 197 6. ESC_K was left out of the EBCDIC table.
630 ph10 189
631 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
632     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
633     limit also applies to "virtual nesting" when a pattern is recursive, and in
634     this case 1000 isn't so big. I have been able to remove this limit at the
635     expense of backing off one optimization in certain circumstances. Normally,
636     when pcre_exec() would call its internal match() function recursively and
637     immediately return the result unconditionally, it uses a "tail recursion"
638     feature to save stack. However, when a subpattern that can match an empty
639     string has an unlimited repetition quantifier, it no longer makes this
640     optimization. That gives it a stack frame in which to save the data for
641     checking that an empty string has been matched. Previously this was taken
642     from the 1000-entry workspace that had been reserved. So now there is no
643     explicit limit, but more stack is used.
644 ph10 189
645 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
646     syntax that is required for Windows, and which was going wrong for the
647     pcreposix and pcrecpp parts of the library. These were overlooked when this
648     problem was solved for the main library.
649 ph10 197
650 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
651     the size of patterns that contain repeated groups with explicit upper
652     limits. As the maximum quantifier is 65535, the maximum group length was
653     set at 30,000 so that the product of these two numbers did not overflow a
654     32-bit integer. However, it turns out that people want to use groups that
655     are longer than 30,000 bytes (though not repeat them that many times).
656     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
657     made it possible to implement the integer overflow checks in a much more
658     dynamic way, which I have now done. The artificial limitation on group
659     length has been removed - we now have only the limit on the total length of
660     the compiled pattern, which depends on the LINK_SIZE setting.
661 ph10 208
662     10. Fixed a bug in the documentation for get/copy named substring when
663     duplicate names are permitted. If none of the named substrings are set, the
664     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
665     empty string.
667     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
668     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
669     because the ] is interpreted as the first data character and the
670     terminating ] is not found. PCRE has been made compatible with Perl in this
671     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
672     cause memory overwriting.
674 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
675     string has been matched (to stop an infinite loop). It was not recognizing
676 ph10 208 a conditional subpattern that could match an empty string if that
677 ph10 206 subpattern was within another subpattern. For example, it looped when
678 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
679 ph10 206 condition was not nested. This bug has been fixed.
680 ph10 208
681 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
682     past the start of the subject in the presence of bytes with the top bit
683     set, for example "\x8aBCD".
684 ph10 211
685 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
686     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
687 ph10 200
688 ph10 211 14. Optimized (?!) to (*FAIL).
689 ph10 202
690 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
691     This restricts code points to be within the range 0 to 0x10FFFF, excluding
692     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
693     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
694     does: it's just the validity check that is more restrictive.
695 ph10 220
696     16. Inserted checks for integer overflows during escape sequence (backslash)
697     processing, and also fixed erroneous offset values for syntax errors during
698     backslash processing.
700 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
701 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
703 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
704     caused an overrun.
705 ph10 220
706     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
707     something other than just ASCII characters) inside a group that had an
708     unlimited repeat caused a loop at compile time (while checking to see
709     whether the group could match an empty string).
711 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
712     [\P{Any}] did so. (Error in the code for printing property names.)
713 ph10 210
714 ph10 220 21. An orphan \E inside a character class could cause a crash.
716     22. A repeated capturing bracket such as (A)? could cause a wild memory
717 ph10 218 reference during compilation.
718 ph10 220
719     23. There are several functions in pcre_compile() that scan along a compiled
720     expression for various reasons (e.g. to see if it's fixed length for look
721 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
722 ph10 220 present in the pattern. These operators have additional parameters compared
723     with \d, etc, and these were not being taken into account when moving along
724 ph10 218 the compiled data. Specifically:
725 ph10 220
726     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
727     length.
729     (b) An item such as \pL+ within a repeated group could cause crashes or
730 ph10 218 loops.
731 ph10 220
732 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
733 ph10 220 "reference to non-existent subpattern" error.
735 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
737 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
738 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
739 ph10 211
740 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
741 ph10 218
742 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
743 ph10 223 character were causing crashes (broken optimization).
744 ph10 227
745 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
746 ph10 227 \p or \P) caused a compile-time loop.
748 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
749     break. For example, the unstudied pattern [\r\n]A does not match the string
750     "\r\nA" because change 7.0/46 below moves the current point on by two
751     characters after failing to match at the start. However, the pattern \nA
752 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
753     the same is true. There doesn't seem any very clean way out of this, but
754     what I have chosen to do makes the common cases work: PCRE now takes note
755     of whether there can be an explicit match for \r or \n anywhere in the
756     pattern, and if so, 7.0/46 no longer applies. As part of this change,
757     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
758     pattern has explicit CR or LF references.
759 ph10 222
760 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
761 ph10 223
762 ph10 227
763 ph10 189 Version 7.2 19-Jun-07
764     ---------------------
766 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
767     which is apparently normally available under Windows.
768 ph10 159
769     2. Re-jig the pcregrep tests with different newline settings in an attempt
770     to make them independent of the local environment's newline setting.
771 ph10 157
772 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
773 ph10 165
774 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
775     was not 2, because the output contained actual offsets. The recent new
776 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
777     usable with all link sizes.
779 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
780     stack recursion. This gives a massive performance boost under BSD, but just
781 ph10 165 a small improvement under Linux. However, it saves one field in the frame
782 ph10 164 in all cases.
783 ph10 172
784 ph10 166 6. Added more features from the forthcoming Perl 5.10:
785 ph10 172
786 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
787     recursion call. It refers to the nth most recently opened parentheses.
788 ph10 172
789 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
790 ph10 172 to be opened parentheses.
792     (c) Conditions that refer to capturing parentheses can be specified
793 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
794 ph10 172
795 ph10 168 (d) \K resets the start of the current match so that everything before
796 ph10 172 is not part of it.
798 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
799 ph10 172
800 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
801 ph10 172 reference syntax.
802 ph10 182
803 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
804 ph10 182 alternative starts with the same number.
805 ph10 172
806 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
808 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
811     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
812     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
813 ph10 170 for detecting groups that can match an empty string.
814 ph10 159
815 ph10 172 9. A pattern with a very large number of alternatives (more than several
816     hundred) was running out of internal workspace during the pre-compile
817     phase, where pcre_compile() figures out how much memory will be needed. A
818     bit of new cunning has reduced the workspace needed for groups with
819     alternatives. The 1000-alternative test pattern now uses 12 bytes of
820     workspace instead of running out of the 4096 that are available.
821 ph10 182
822 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
823 ph10 172
824 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
825     The report of the bug said:
826 ph10 182
827 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
828     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
829 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
830 ph10 185
831 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
832 ph10 185 it matched the wrong number of bytes.
833 ph10 172
834 ph10 179
835 ph10 155 Version 7.1 24-Apr-07
836 ph10 98 ---------------------
838 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
839 ph10 122 that is more "standard", making use of automake and other Autotools. There
840 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
841     on this.
842 ph10 111
843     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
844     for recursive directory scanning broke on some systems because the files
845     are not scanned in any specific order and on different systems the order
846     was different. A call to "sort" has been inserted into RunGrepTest for the
847     approprate test as a short-term fix. In the longer term there may be an
848 ph10 100 alternative.
849 ph10 111
850 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
851 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
852     people do their own conversions for various reasons). The problems
853     concerned the use of low-level troff macros .br and .in. I have therefore
854     removed all such uses from the man pages (some were redundant, some could
855 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
856     HTML has been updated to handle .nf/.fi and to complain if it encounters
857     .br or .in.
858 ph10 111
859 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
860 ph10 123 arranged for config.h to be included in the distribution, with the name
861 ph10 111 config.h.generic, for the benefit of those who have to compile without
862     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
864     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
865     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
866 ph10 127 makevp.bat for the current PCRE, using the additional files
867 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
868 ph10 111
869     6. A Windows user reported a minor discrepancy with test 2, which turned out
870     to be caused by a trailing space on an input line that had got lost in his
871 ph10 102 copy. The trailing space was an accident, so I've just removed it.
872 ph10 111
873 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
874 ph10 111 that is needed.
876 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
877     as "const" (a) because they are and (b) because it helps the PHP
878     maintainers who have recently made a script to detect big data structures
879 ph10 111 in the php code that should be moved to the .rodata section. I remembered
880     to update Builducptable as well, so it won't revert if ucptable.h is ever
881 ph10 105 re-created.
882 ph10 111
883     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
884 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
885 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
886     support is not required. This saves 1.5-2K of code, which is important in
887 ph10 107 some applications.
888 ph10 111
889 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
890 ph10 111 so as not to refer to the tables, even though these functions will never be
891     called when UTF-8 support is disabled. Otherwise there are problems with a
892     shared library.
894 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
896     (a) It was defining its arguments as char * instead of void *.
898 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
899     a long time ago when I wrote it, but is no longer the case.
901 ph10 118 The emulated memove() is provided for those environments that have neither
902 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
903 ph10 118 is clearly not the case, as these two bugs were recently reported.
904 ph10 123
905 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
906 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
907     pages, and it removes trailing spaces from listed files. It also creates
908     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
909     case, it wraps all the #defines with #ifndefs. This script should be run
910 ph10 111 before "make dist".
911 ph10 123
912 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
913     with Unicode property support.
914 ph10 123
915     (a) For a maximizing quantifier, if the two different cases of the
916     character were of different lengths in their UTF-8 codings (there are
917     some cases like this - I found 11), and the matching function had to
918 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
919     were both the same length.
920 ph10 123
921     (b) When PCRE was configured to use the heap rather than the stack for
922     recursion during matching, it was not correctly preserving the data for
923     the other case of a UTF-8 character when checking ahead for a match
924     while processing a minimizing repeat. If the check also involved
925 ph10 115 matching a wide character, but failed, corruption could cause an
926     erroneous result when trying to check for a repeat of the original
927     character.
928 ph10 123
929 ph10 116 13. Some tidying changes to the testing mechanism:
930 ph10 98
931 ph10 116 (a) The RunTest script now detects the internal link size and whether there
932     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
933 ph10 123 values substituted by "configure". (The RunGrepTest script already did
934     this for UTF-8.) The configure.ac script no longer substitutes the
935     relevant variables.
937 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
938     with length and offset values. This means that the output is different
939     for different internal link sizes. Test 2 is skipped for link sizes
940     other than 2 because of this, bypassing the problem. Unfortunately,
941     there was also a test in test 3 (the locale tests) that used /B and
942 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
943     I have added a new /Z option to pcretest that replaces the length and
944     offset values with spaces. This is now used to make test 3 independent
945 ph10 122 of link size. (Test 2 will be tidied up later.)
946 ph10 123
947     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
948 ph10 122 segmentation fault instead of returning the appropriate error message.
949 ph10 134
950 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
951 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
952     This doesn't seem right; it now treats the CRLF combination as the line
953     ending, and so does not match in that case. It's only a pattern such as ^$
954     that would hit this one: something like ^ABC$ would have failed after \r
955     and then tried again after \r\n.
957 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
958 ph10 134 in an attempt to make files that differ only in their line terminators
959     compare equal. This works on Linux.
960 ph10 142
961 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
962     as it exited. This is now fixed, thanks to valgrind.
963 ph10 142
964 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
965 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
966     was because its rules for how to advance for /g after matching an empty
967 ph10 143 string at the end of a line did not allow for this case. They now check for
968     it specially.
969 ph10 150
970     20. pcretest is supposed to handle patterns and data of any length, by
971     extending its buffers when necessary. It was getting this wrong when the
972 ph10 147 buffer for a data line had to be extended.
973 ph10 150
974 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
975 ph10 150 CRLF as a newline sequence.
976 ph10 152
977 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
978 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
979     I have nevertheless tidied it up.
980 ph10 111
981 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
982 ph10 123
983 ph10 153 24. Added a man page for pcre-config.
984 ph10 152
985 ph10 153
986 nigel 93 Version 7.0 19-Dec-06
987     ---------------------
989     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
990     moving to gcc 4.1.1.
992     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
993     sys/time.h, which is documented as needed for this function. It doesn't
994     seem to matter on Linux, but it showed up on some releases of OS X.
996     3. It seems that there are systems where bytes whose values are greater than
997     127 match isprint() in the "C" locale. The "C" locale should be the
998     default when a C program starts up. In most systems, only ASCII printing
999     characters match isprint(). This difference caused the output from pcretest
1000     to vary, making some of the tests fail. I have changed pcretest so that:
1002     (a) When it is outputting text in the compiled version of a pattern, bytes
1003     other than 32-126 are always shown as hex escapes.
1005     (b) When it is outputting text that is a matched part of a subject string,
1006     it does the same, unless a different locale has been set for the match
1007     (using the /L modifier). In this case, it uses isprint() to decide.
1009     4. Fixed a major bug that caused incorrect computation of the amount of memory
1010     required for a compiled pattern when options that changed within the
1011     pattern affected the logic of the preliminary scan that determines the
1012     length. The relevant options are -x, and -i in UTF-8 mode. The result was
1013     that the computed length was too small. The symptoms of this bug were
1014     either the PCRE error "internal error: code overflow" from pcre_compile(),
1015     or a glibc crash with a message such as "pcretest: free(): invalid next
1016     size (fast)". Examples of patterns that provoked this bug (shown in
1017     pcretest format) are:
1019     /(?-x: )/x
1020     /(?x)(?-x: \s*#\s*)/
1021     /((?i)[\x{c0}])/8
1022     /(?i:[\x{c0}])/8
1024     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
1025     is now done differently.
1027     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1028     wrapper classes; (b) implement a new function in the C++ scanner that is
1029     more efficient than the old way of doing things because it avoids levels of
1030     recursion in the regex matching; (c) add a paragraph to the documentation
1031     for the FullMatch() function.
1033     6. The escape sequence \n was being treated as whatever was defined as
1034     "newline". Not only was this contrary to the documentation, which states
1035     that \n is character 10 (hex 0A), but it also went horribly wrong when
1036     "newline" was defined as CRLF. This has been fixed.
1038     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1039     was being set to -1 for the "end of line" case (supposedly a value that no
1040     character can have). Though this value is never used (the check for end of
1041     line is "zero bytes in current character"), it caused compiler complaints.
1042     I've changed it to 0xffffffff.
1044     8. In pcre_version.c, the version string was being built by a sequence of
1045     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1046     string (as it is for production releases) called a macro with an empty
1047     argument. The C standard says the result of this is undefined. The gcc
1048     compiler treats it as an empty string (which was what was wanted) but it is
1049     reported that Visual C gives an error. The source has been hacked around to
1050     avoid this problem.
1052     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1053     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1054     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1055     of them did).
1057     10. Originally, pcretest opened its input and output without "b"; then I was
1058     told that "b" was needed in some environments, so it was added for release
1059     5.0 to both the input and output. (It makes no difference on Unix-like
1060     systems.) Later I was told that it is wrong for the input on Windows. I've
1061     now abstracted the modes into two macros, to make it easier to fiddle with
1062     them, and removed "b" from the input mode under Windows.
1064     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1066     12. Added -help and --help to pcretest as an official way of being reminded
1067     of the options.
1069     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1070     and pcrecpp.cc because they annoy compilers at high warning levels.
1072     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1074     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1075     scripts are not C programs :-) and which was not noticed because it works
1076     on Linux.
1078     16. pcretest is supposed to handle any length of pattern and data line (as one
1079     line or as a continued sequence of lines) by extending its input buffer if
1080     necessary. This feature was broken for very long pattern lines, leading to
1081     a string of junk being passed to pcre_compile() if the pattern was longer
1082     than about 50K.
1084     17. I have done a major re-factoring of the way pcre_compile() computes the
1085     amount of memory needed for a compiled pattern. Previously, there was code
1086     that made a preliminary scan of the pattern in order to do this. That was
1087     OK when PCRE was new, but as the facilities have expanded, it has become
1088     harder and harder to keep it in step with the real compile phase, and there
1089     have been a number of bugs (see for example, 4 above). I have now found a
1090     cunning way of running the real compile function in a "fake" mode that
1091     enables it to compute how much memory it would need, while actually only
1092     ever using a few hundred bytes of working memory and without too many
1093     tests of the mode. This should make future maintenance and development
1094     easier. A side effect of this work is that the limit of 200 on the nesting
1095     depth of parentheses has been removed (though this was never a serious
1096     limitation, I suspect). However, there is a downside: pcre_compile() now
1097     runs more slowly than before (30% or more, depending on the pattern). I
1098     hope this isn't a big issue. There is no effect on runtime performance.
1100     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1101     newline (only possible for the last line of a file) and it was a
1102     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1104     19. Added additional timing features to pcretest. (1) The -tm option now times
1105     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1106     separate command line item, by a number that specifies the number of
1107     repeats to use when timing. The default is 50000; this gives better
1108     precision, but takes uncomfortably long for very large patterns.
1110     20. Extended pcre_study() to be more clever in cases where a branch of a
1111     subpattern has no definite first character. For example, (a*|b*)[cd] would
1112     previously give no result from pcre_study(). Now it recognizes that the
1113     first character must be a, b, c, or d.
1115     21. There was an incorrect error "recursive call could loop indefinitely" if
1116     a subpattern (or the entire pattern) that was being tested for matching an
1117     empty string contained only one non-empty item after a nested subpattern.
1118     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1119     incorrectly, because the \d was being skipped in the check.
1121     22. The pcretest program now has a new pattern option /B and a command line
1122     option -b, which is equivalent to adding /B to every pattern. This causes
1123     it to show the compiled bytecode, without the additional information that
1124     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1125     is the same as /B/I).
1127     23. A new optimization is now able automatically to treat some sequences such
1128     as a*b as a*+b. More specifically, if something simple (such as a character
1129     or a simple class like \d) has an unlimited quantifier, and is followed by
1130     something that cannot possibly match the quantified thing, the quantifier
1131     is automatically "possessified".
1133     24. A recursive reference to a subpattern whose number was greater than 39
1134     went wrong under certain circumstances in UTF-8 mode. This bug could also
1135     have affected the operation of pcre_study().
1137     25. Realized that a little bit of performance could be had by replacing
1138     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1140     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1142     27. Possessive quantifiers such as a++ were previously implemented by turning
1143     them into atomic groups such as ($>a+). Now they have their own opcodes,
1144     which improves performance. This includes the automatically created ones
1145     from 23 above.
1147     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1148     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1149     the first matched character to be a colon. This applied both to named and
1150     numbered groups.
1152     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1154     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1155     building PCRE on Windows easier, so I have included it in the distribution.
1157     31. There is now a check in pcretest against a ridiculously large number being
1158     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1159     loop, the loop is abandoned.
1161     32. Forward references to subpatterns in conditions such as (?(2)...) where
1162     subpattern 2 is defined later cause pcre_compile() to search forwards in
1163     the pattern for the relevant set of parentheses. This search went wrong
1164     when there were unescaped parentheses in a character class, parentheses
1165     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1167     33. "Subroutine" calls and backreferences were previously restricted to
1168     referencing subpatterns earlier in the regex. This restriction has now
1169     been removed.
1171     34. Added a number of extra features that are going to be in Perl 5.10. On the
1172     whole, these are just syntactic alternatives for features that PCRE had
1173     previously implemented using the Python syntax or my own invention. The
1174     other formats are all retained for compatibility.
1176     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1177     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1178     also .NET compatible.
1180     (b) A recursion or subroutine call to a named group can now be defined as
1181     (?&name) as well as (?P>name).
1183     (c) A backreference to a named group can now be defined as \k<name> or
1184     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1185     5.10, are also .NET compatible.
1187     (d) A conditional reference to a named group can now use the syntax
1188     (?(<name>) or (?('name') as well as (?(name).
1190     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1191     groups (named and numbered) that are never evaluated inline, but can be
1192     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1193     is always false. There may be only one alternative in such a group.
1195     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1196     as the simple (?(R). The condition is true only if the most recent
1197     recursion is that of the given number or name. It does not search out
1198     through the entire recursion stack.
1200     (g) The escape \gN or \g{N} has been added, where N is a positive or
1201     negative number, specifying an absolute or relative reference.
1203     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1204     some "unreachable code" warnings.
1206     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1207     things, this adds five new scripts.
1209     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1210     There were also incompatibilities regarding the handling of \Q..\E inside
1211     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1212     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1214     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1215     matches an empty string, and forcibly breaks the loop. There were bugs in
1216     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1217     against aaaa the result was just "a" rather than "aaaa", for example. Two
1218     separate and independent bugs (that affected different cases) have been
1219     fixed.
1221     39. Refactored the code to abolish the use of different opcodes for small
1222     capturing bracket numbers. This is a tidy that I avoided doing when I
1223     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1224     The new approach is not only tidier, it makes it possible to reduce the
1225     memory needed to fix the previous bug (38).
1227     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1228     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1229     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1230     mode.
1232     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1233     report.
1235     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1236     copy construction and assignment in the C++ wrapper.
1238     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1239     couple of bugs that could have given wrong results in the "--newline=crlf"
1240     case.
1242     44. Added a number of casts and did some reorganization of signed/unsigned int
1243     variables following suggestions from Dair Grant. Also renamed the variable
1244     "this" as "item" because it is a C++ keyword.
1246     45. Arranged for dftables to add
1248     #include "pcre_internal.h"
1250     to pcre_chartables.c because without it, gcc 4.x may remove the array
1251     definition from the final binary if PCRE is built into a static library and
1252     dead code stripping is activated.
1254     46. For an unanchored pattern, if a match attempt fails at the start of a
1255     newline sequence, and the newline setting is CRLF or ANY, and the next two
1256     characters are CRLF, advance by two characters instead of one.
1259 nigel 91 Version 6.7 04-Jul-06
1260     ---------------------
1262     1. In order to handle tests when input lines are enormously long, pcretest has
1263     been re-factored so that it automatically extends its buffers when
1264     necessary. The code is crude, but this _is_ just a test program. The
1265     default size has been increased from 32K to 50K.
1267     2. The code in pcre_study() was using the value of the re argument before
1268     testing it for NULL. (Of course, in any sensible call of the function, it
1269     won't be NULL.)
1271     3. The memmove() emulation function in pcre_internal.h, which is used on
1272     systems that lack both memmove() and bcopy() - that is, hardly ever -
1273     was missing a "static" storage class specifier.
1275     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1276     containing an extended class (one that cannot be represented by a bitmap
1277     because it contains high-valued characters or Unicode property items, e.g.
1278     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1279     pattern, but PCRE should not loop if you do not (it no longer does).
1280     [Detail: two cases were found: (a) a repeated subpattern containing an
1281     extended class; (b) a recursive reference to a subpattern that followed a
1282     previous extended class. It wasn't skipping over the extended class
1283     correctly when UTF-8 mode was not set.]
1285     5. A negated single-character class was not being recognized as fixed-length
1286     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1287     compile error "lookbehind assertion is not fixed length".
1289     6. The RunPerlTest auxiliary script was showing an unexpected difference
1290     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1291     write a Perl script that can interpret lines of an input file either as
1292     byte characters or as UTF-8, which is what "perltest" was being required to
1293     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1294     can't do is switch easily at run time between having the "use utf8;" pragma
1295     or not. In the end, I fudged it by using the RunPerlTest script to insert
1296     "use utf8;" explicitly for the UTF-8 tests.
1298     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1299     the end of the subject string, contrary to the documentation and to what
1300     Perl does. This was true of both matching functions. Now it matches only at
1301     the start of the subject and immediately after *internal* newlines.
1303     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1304     a pointer to an int instead of a pointer to an unsigned long int. This
1305     caused problems on 64-bit systems.
1307     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1308     instance of the 'standard' template library not being so standard".
1310     10. There was no check on the number of named subpatterns nor the maximum
1311     length of a subpattern name. The product of these values is used to compute
1312     the size of the memory block for a compiled pattern. By supplying a very
1313     long subpattern name and a large number of named subpatterns, the size
1314     computation could be caused to overflow. This is now prevented by limiting
1315     the length of names to 32 characters, and the number of named subpatterns
1316     to 10,000.
1318     11. Subpatterns that are repeated with specific counts have to be replicated in
1319     the compiled pattern. The size of memory for this was computed from the
1320     length of the subpattern and the repeat count. The latter is limited to
1321     65535, but there was no limit on the former, meaning that integer overflow
1322     could in principle occur. The compiled length of a repeated subpattern is
1323     now limited to 30,000 bytes in order to prevent this.
1325     12. Added the optional facility to have named substrings with the same name.
1327     13. Added the ability to use a named substring as a condition, using the
1328     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1329     are numbers (not recommended). Forward references are permitted.
1331     14. Added forward references in named backreferences (if you see what I mean).
1333     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1334     pattern could run off the end of the subject. For example, the pattern
1335     "(?s)(.{1,5})"8 did this with the subject "ab".
1337     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1338     PCRE_CASELESS was set when matching characters that were quantified with ?
1339     or *.
1341     17. A character class other than a single negated character that had a minimum
1342     but no maximum quantifier - for example [ab]{6,} - was not handled
1343     correctly by pce_dfa_exec(). It would match only one character.
1345     18. A valid (though odd) pattern that looked like a POSIX character
1346     class but used an invalid character after [ (for example [[,abc,]]) caused
1347     pcre_compile() to give the error "Failed: internal error: code overflow" or
1348     in some cases to crash with a glibc free() error. This could even happen if
1349     the pattern terminated after [[ but there just happened to be a sequence of
1350     letters, a binary zero, and a closing ] in the memory that followed.
1352     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1353     over the years. Originally (before any Unicode support), just the bottom 8
1354     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1355     output from "man perlunicode" includes this:
1357     The regular expression compiler produces polymorphic opcodes. That
1358     is, the pattern adapts to the data and automatically switches to
1359     the Unicode character scheme when presented with Unicode data--or
1360     instead uses a traditional byte scheme when presented with byte
1361     data.
1363     Sadly, a wide octal escape does not cause a switch, and in a string with
1364     no other multibyte characters, these octal escapes are treated as before.
1365     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1366     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1367     Unicode string.
1369     I have not perpetrated such confusion in PCRE. Up till now, it took just
1370     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1371     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1372     translate to the appropriate multibyte character.
1374     29. Applied some refactoring to reduce the number of warnings from Microsoft
1375     and Borland compilers. This has included removing the fudge introduced
1376     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1377     a warning about an unused variable.
1379     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1380     characters since release 4.0, because Perl (from release 5.004) does not.
1381     [Or at least, is documented not to: some releases seem to be in conflict
1382     with the documentation.] However, when a pattern was studied with
1383     pcre_study() and all its branches started with \s, PCRE still included VT
1384     as a possible starting character. Of course, this did no harm; it just
1385     caused an unnecessary match attempt.
1387     22. Removed a now-redundant internal flag bit that recorded the fact that case
1388     dependency changed within the pattern. This was once needed for "required
1389     byte" processing, but is no longer used. This recovers a now-scarce options
1390     bit. Also moved the least significant internal flag bit to the most-
1391     significant bit of the word, which was not previously used (hangover from
1392     the days when it was an int rather than a uint) to free up another bit for
1393     the future.
1395     23. Added support for CRLF line endings as well as CR and LF. As well as the
1396     default being selectable at build time, it can now be changed at runtime
1397     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1398     specify that it is scanning data with non-default line endings.
1400     24. Changed the definition of CXXLINK to make it agree with the definition of
1401     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1403     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1404     recursions. This makes a big different to stack usage for some patterns.
1406     26. If a subpattern containing a named recursion or subroutine reference such
1407     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1408     the space required for the compiled pattern went wrong and gave too small a
1409     value. Depending on the environment, this could lead to "Failed: internal
1410     error: code overflow at offset 49" or "glibc detected double free or
1411     corruption" errors.
1413     27. Applied patches from Google (a) to support the new newline modes and (b) to
1414     advance over multibyte UTF-8 characters in GlobalReplace.
1416     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1417     difference for some implementation of PCRE in some Windows version.
1419     29. Added some extra testing facilities to pcretest:
1421     \q<number> in a data line sets the "match limit" value
1422     \Q<number> in a data line sets the "match recursion limt" value
1423     -S <number> sets the stack size, where <number> is in megabytes
1425     The -S option isn't available for Windows.
1428 nigel 89 Version 6.6 06-Feb-06
1429     ---------------------
1431     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1432     in pcreposix.h. I have copied the definition from pcre.h.
1434     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1435     because pcre.h is no longer a built file.
1437     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1438     not normally included in the compiled code.
1441 nigel 87 Version 6.5 01-Feb-06
1442     ---------------------
1444     1. When using the partial match feature with pcre_dfa_exec(), it was not
1445     anchoring the second and subsequent partial matches at the new starting
1446     point. This could lead to incorrect results. For example, with the pattern
1447     /1234/, partially matching against "123" and then "a4" gave a match.
1449     2. Changes to pcregrep:
1451     (a) All non-match returns from pcre_exec() were being treated as failures
1452     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1453     error message is output. Some extra information is given for the
1455     probably the only errors that are likely to be caused by users (by
1456     specifying a regex that has nested indefinite repeats, for instance).
1457     If there are more than 20 of these errors, pcregrep is abandoned.
1459     (b) A binary zero was treated as data while matching, but terminated the
1460     output line if it was written out. This has been fixed: binary zeroes
1461     are now no different to any other data bytes.
1463     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1464     used to set a locale for matching. The --locale=xxxx long option has
1465     been added (no short equivalent) to specify a locale explicitly on the
1466     pcregrep command, overriding the environment variables.
1468     (d) When -B was used with -n, some line numbers in the output were one less
1469     than they should have been.
1471     (e) Added the -o (--only-matching) option.
1473     (f) If -A or -C was used with -c (count only), some lines of context were
1474     accidentally printed for the final match.
1476     (g) Added the -H (--with-filename) option.
1478     (h) The combination of options -rh failed to suppress file names for files
1479     that were found from directory arguments.
1481     (i) Added the -D (--devices) and -d (--directories) options.
1483     (j) Added the -F (--fixed-strings) option.
1485     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1487     (l) Added the --colo(u)r option.
1489     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1490     is not present by default.
1492     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1493     items such as (?R) or (?1), when the recursion could match a number of
1494     alternatives. If it matched one of the alternatives, but subsequently,
1495     outside the recursion, there was a failure, the code tried to back up into
1496     the recursion. However, because of the way PCRE is implemented, this is not
1497     possible, and the result was an incorrect result from the match.
1499     In order to prevent this happening, the specification of recursion has
1500     been changed so that all such subpatterns are automatically treated as
1501     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1503     4. I had overlooked the fact that, in some locales, there are characters for
1504     which isalpha() is true but neither isupper() nor islower() are true. In
1505     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1506     and ordfeminine) are like this. This affected the treatment of \w and \W
1507     when they appeared in character classes, but not when they appeared outside
1508     a character class. The bit map for "word" characters is now created
1509     separately from the results of isalnum() instead of just taking it from the
1510     upper, lower, and digit maps. (Plus the underscore character, of course.)
1512     5. The above bug also affected the handling of POSIX character classes such as
1513     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1514     permanent tables. Instead, the bit maps for such a class were previously
1515     created as the appropriate unions of the upper, lower, and digit bitmaps.
1516     Now they are created by subtraction from the [[:word:]] class, which has
1517     its own bitmap.
1519     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1520     It is created by subtracting the vertical space characters (\x09, \x0a,
1521     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1522     subtraction was done in the overall bitmap for a character class, meaning
1523     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1524     be recognized. This bug has been fixed.
1526     7. Patches from the folks at Google:
1528     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1529     real life, but is still worth protecting against".
1531     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1532     regular expressions".
1534     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1535     have it.
1537     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1538     "configure" and the latter not, in order to fix a problem somebody had
1539     with compiling the Arg class on HP-UX.
1541     (e) Improve the error-handling of the C++ wrapper a little bit.
1543     (f) New tests for checking recursion limiting.
1545     8. The pcre_memmove() function, which is used only if the environment does not
1546     have a standard memmove() function (and is therefore rarely compiled),
1547     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1548     returning a result (though PCRE never actually uses the result).
1550     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1551     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1552     returned instead of calling malloc() with an overflowing number that would
1553     most likely cause subsequent chaos.
1555     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1557     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1558     with this option is matched, the nmatch and pmatch options of regexec() are
1559     ignored.
1561     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1562     provided in case anyone wants to the the POSIX interface with UTF-8
1563     strings.
1565     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1566     C++ linking (needed for some HP-UX environments).
1568     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1569     (unused parameter) and in the pcre_printint() function (omitted "default"
1570     switch label when the default is to do nothing).
1572     15. Added some code to make it possible, when PCRE is compiled as a C++
1573     library, to replace subject pointers for pcre_exec() with a smart pointer
1574     class, thus making it possible to process discontinuous strings.
1576     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1577     much the same function. They were added by different people who were trying
1578     to make PCRE easy to compile on non-Unix systems. It has been suggested
1579     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1580     for compiling on Windows systems. I have therefore replaced it with
1581     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1582     defaults to "extern" for C or "extern C" for C++, which works fine on
1583     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1584     SCOPE with something explicit in config.h. In addition:
1586     (a) pcreposix.h still had just "extern" instead of either of these macros;
1587     I have replaced it with PCRE_DATA_SCOPE.
1589     (b) Functions such as _pcre_xclass(), which are internal to the library,
1590     but external in the C sense, all had PCRE_EXPORT in their definitions.
1591     This is apparently wrong for the Windows case, so I have removed it.
1592     (It makes no difference on Unix-like systems.)
1594     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1595     of recursive calls to match(). This is different to MATCH_LIMIT because
1596     that limits the total number of calls to match(), not all of which increase
1597     the depth of recursion. Limiting the recursion depth limits the amount of
1598     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1599     when PCRE is compiled, and changed at run time. A patch from Google adds
1600     this functionality to the C++ interface.
1602     18. Changes to the handling of Unicode character properties:
1604     (a) Updated the table to Unicode 4.1.0.
1606     (b) Recognize characters that are not in the table as "Cn" (undefined).
1608     (c) I revised the way the table is implemented to a much improved format
1609     which includes recognition of ranges. It now supports the ranges that
1610     are defined in UnicodeData.txt, and it also amalgamates other
1611     characters into ranges. This has reduced the number of entries in the
1612     table from around 16,000 to around 3,000, thus reducing its size
1613     considerably. I realized I did not need to use a tree structure after
1614     all - a binary chop search is just as efficient. Having reduced the
1615     number of entries, I extended their size from 6 bytes to 8 bytes to
1616     allow for more data.
1618     (d) Added support for Unicode script names via properties such as \p{Han}.
1620     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1621     matching that character.
1623     20. When matching a repeated Unicode property with a minimum greater than zero,
1624     (for example \pL{2,}), PCRE could look past the end of the subject if it
1625     reached it while seeking the minimum number of characters. This could
1626     happen only if some of the characters were more than one byte long, because
1627     there is a check for at least the minimum number of bytes.
1629     21. Refactored the implementation of \p and \P so as to be more general, to
1630     allow for more different types of property in future. This has changed the
1631     compiled form incompatibly. Anybody with saved compiled patterns that use
1632     \p or \P will have to recompile them.
1634     22. Added "Any" and "L&" to the supported property types.
1636     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1637     but give a compile time error if the value is greater than 0xff.
1639     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1640     accidentally not being installed or uninstalled.
1642     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1643     made were to insert the current release number. This seemed silly, because
1644     it made things harder for people building PCRE on systems that don't run
1645     "configure". I have turned pcre.h into a distributed file, no longer built
1646     by "configure", with the version identification directly included. There is
1647     no longer a pcre.h.in file.
1649     However, this change necessitated a change to the pcre-config script as
1650     well. It is built from pcre-config.in, and one of the substitutions was the
1651     release number. I have updated configure.ac so that ./configure now finds
1652     the release number by grepping pcre.h.
1654     26. Added the ability to run the tests under valgrind.
1657 nigel 85 Version 6.4 05-Sep-05
1658     ---------------------
1660     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1661     "--" to be printed when multiple files were scanned, even when none of the
1662     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1663     consider it to be a bug, and have restored the previous behaviour.
1665     2. A couple of code tidies to get rid of compiler warnings.
1667     3. The pcretest program used to cheat by referring to symbols in the library
1668     whose names begin with _pcre_. These are internal symbols that are not
1669     really supposed to be visible externally, and in some environments it is
1670     possible to suppress them. The cheating is now confined to including
1671     certain files from the library's source, which is a bit cleaner.
1673     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1674     file's purpose clearer.
1676     5. Reorganized pcre_ucp_findchar().
1679 nigel 83 Version 6.3 15-Aug-05
1680     ---------------------
1682     1. The file libpcre.pc.in did not have general read permission in the tarball.
1684     2. There were some problems when building without C++ support:
1686     (a) If C++ support was not built, "make install" and "make test" still
1687     tried to test it.
1689     (b) There were problems when the value of CXX was explicitly set. Some
1690     changes have been made to try to fix these, and ...
1692     (c) --disable-cpp can now be used to explicitly disable C++ support.
1694     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1695     backslash in a target when C++ was disabled. This confuses some
1696     versions of "make", apparently. Using an intermediate variable solves
1697     this. (Same for CPP_LOBJ.)
1699     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1700     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1701     necessary on certain architectures.
1703     4. Added a setting of -export-symbols-regex to the link command to remove
1704     those symbols that are exported in the C sense, but actually are local
1705     within the library, and not documented. Their names all begin with
1706     "_pcre_". This is not a perfect job, because (a) we have to except some
1707     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1708     available (and never for static libraries). I have made a note to try to
1709     find a way round (a) in the future.
1712 nigel 81 Version 6.2 01-Aug-05
1713     ---------------------
1715     1. There was no test for integer overflow of quantifier values. A construction
1716     such as {1111111111111111} would give undefined results. What is worse, if
1717     a minimum quantifier for a parenthesized subpattern overflowed and became
1718     negative, the calculation of the memory size went wrong. This could have
1719     led to memory overwriting.
1721     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1723     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1724     operating environments where this matters.
1726     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1727     PCRE options from within the C++ wrapper.
1729     5. Named capturing subpatterns were not being correctly counted when a pattern
1730     was compiled. This caused two problems: (a) If there were more than 100
1731     such subpatterns, the calculation of the memory needed for the whole
1732     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1733     back references of the form \12, where the number was greater than 9, were
1734     not recognized as back references, even though there were sufficient
1735     previous subpatterns.
1737     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1738     versions of gcc, e.g. 2.95.4.
1741 nigel 79 Version 6.1 21-Jun-05
1742     ---------------------
1744     1. There was one reference to the variable "posix" in pcretest.c that was not
1745     surrounded by "#if !defined NOPOSIX".
1747     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1748     the cross-check on the old pcre_info() function, for the benefit of the
1749     cut-down version of PCRE that is currently imported into Exim.
1751     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1752     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1753     patterns that start (?i) but I don't think that matters. The use of (?i) is
1754     just an example; this all applies to the other options as well.
1756     4. Since libtool seems to echo the compile commands it is issuing, the output
1757     from "make" can be reduced a bit by putting "@" in front of each libtool
1758     compile command.
1760     5. Patch from the folks at Google for configure.in to be a bit more thorough
1761     in checking for a suitable C++ installation before trying to compile the
1762     C++ stuff. This should fix a reported problem when a compiler was present,
1763     but no suitable headers.
1765     6. The man pages all had just "PCRE" as their title. I have changed them to
1766     be the relevant file name. I have also arranged that these names are
1767     retained in the file doc/pcre.txt, which is a concatenation in text format
1768     of all the man pages except the little individual ones for each function.
1770     7. The NON-UNIX-USE file had not been updated for the different set of source
1771     files that come with release 6. I also added a few comments about the C++
1772     wrapper.
1775 nigel 77 Version 6.0 07-Jun-05
1776     ---------------------
1778     1. Some minor internal re-organization to help with my DFA experiments.
1780     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1781     didn't matter for the library itself when fully configured, but did matter
1782     when compiling without UCP support, or within Exim, where the ucp files are
1783     not imported.
1785     3. Refactoring of the library code to split up the various functions into
1786     different source modules. The addition of the new DFA matching code (see
1787     below) to a single monolithic source would have made it really too
1788     unwieldy, quite apart from causing all the code to be include in a
1789     statically linked application, when only some functions are used. This is
1790     relevant even without the DFA addition now that patterns can be compiled in
1791     one application and matched in another.
1793     The downside of splitting up is that there have to be some external
1794     functions and data tables that are used internally in different modules of
1795     the library but which are not part of the API. These have all had their
1796     names changed to start with "_pcre_" so that they are unlikely to clash
1797     with other external names.
1799     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1800     a different (DFA) algorithm. Although it is slower than the original
1801     function, it does have some advantages for certain types of matching
1802     problem.
1804     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1805     including restarting after a partial match.
1807     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1808     defined when compiling for Windows was sent to me. I have put it into the
1809     code, though I have no means of testing or verifying it.
1811     7. Added the pcre_refcount() auxiliary function.
1813     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1814     match before or at the first newline in the subject string. In pcretest,
1815     the /f option on a pattern can be used to set this.
1817     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1818     would behave wrongly. This has been present in PCRE since release 4.0.
1820     10. A number of changes to the pcregrep command:
1822     (a) Refactored how -x works; insert ^(...)$ instead of setting
1823     PCRE_ANCHORED and checking the length, in preparation for adding
1824     something similar for -w.
1826     (b) Added the -w (match as a word) option.
1828     (c) Refactored the way lines are read and buffered so as to have more
1829     than one at a time available.
1831     (d) Implemented a pcregrep test script.
1833     (e) Added the -M (multiline match) option. This allows patterns to match
1834     over several lines of the subject. The buffering ensures that at least
1835     8K, or the rest of the document (whichever is the shorter) is available
1836     for matching (and similarly the previous 8K for lookbehind assertions).
1838     (f) Changed the --help output so that it now says
1840     -w, --word-regex(p)
1842     instead of two lines, one with "regex" and the other with "regexp"
1843     because that confused at least one person since the short forms are the
1844     same. (This required a bit of code, as the output is generated
1845     automatically from a table. It wasn't just a text change.)
1847     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1848     option but starts with a hyphen. Could be a pattern or a path name
1849     starting with a hyphen, for instance.
1851     (h) "-" can be given as a file name to represent stdin.
1853     (i) When file names are being printed, "(standard input)" is used for
1854     the standard input, for compatibility with GNU grep. Previously
1855     "<stdin>" was used.
1857     (j) The option --label=xxx can be used to supply a name to be used for
1858     stdin when file names are being printed. There is no short form.
1860     (k) Re-factored the options decoding logic because we are going to add
1861     two more options that take data. Such options can now be given in four
1862     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1864     (l) Added the -A, -B, and -C options for requesting that lines of context
1865     around matches be printed.
1867     (m) Added the -L option to print the names of files that do not contain
1868     any matching lines, that is, the complement of -l.
1870     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1871     continue to scan other files.
1873     (o) The -s option was incorrectly implemented. For compatibility with other
1874     greps, it now suppresses the error message for a non-existent or non-
1875     accessible file (but not the return code). There is a new option called
1876     -q that suppresses the output of matching lines, which was what -s was
1877     previously doing.
1879     (p) Added --include and --exclude options to specify files for inclusion
1880     and exclusion when recursing.
1882     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1883     Hopefully, it now does.
1885     12. Missing cast in pcre_study().
1887     13. Added an "uninstall" target to the makefile.
1889     14. Replaced "extern" in the function prototypes in Makefile.in with
1890     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1891     world, but is set differently for Windows.
1893     15. Added a second compiling function called pcre_compile2(). The only
1894     difference is that it has an extra argument, which is a pointer to an
1895     integer error code. When there is a compile-time failure, this is set
1896     non-zero, in addition to the error test pointer being set to point to an
1897     error message. The new argument may be NULL if no error number is required
1898     (but then you may as well call pcre_compile(), which is now just a
1899     wrapper). This facility is provided because some applications need a
1900     numeric error indication, but it has also enabled me to tidy up the way
1901     compile-time errors are handled in the POSIX wrapper.
1903     16. Added VPATH=.libs to the makefile; this should help when building with one
1904     prefix path and installing with another. (Or so I'm told by someone who
1905     knows more about this stuff than I do.)
1907     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1908     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1909     match everything, including newlines. This is not POSIX-compatible, but
1910     somebody wanted the feature. From pcretest it can be activated by using
1911     both the P and the s flags.
1913     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1915     19. libpcre.pc was being incorrectly installed as executable.
1917     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1918     it now also looks for '\r' so that it will work unmodified on Windows.
1920     21. Added Google's contributed C++ wrapper to the distribution.
1922     22. Added some untidy missing memory free() calls in pcretest, to keep
1923     Electric Fence happy when testing.
1927 nigel 75 Version 5.0 13-Sep-04
1928     ---------------------
1930     1. Internal change: literal characters are no longer packed up into items
1931     containing multiple characters in a single byte-string. Each character
1932     is now matched using a separate opcode. However, there may be more than one
1933     byte in the character in UTF-8 mode.
1935     2. The pcre_callout_block structure has two new fields: pattern_position and
1936     next_item_length. These contain the offset in the pattern to the next match
1937     item, and its length, respectively.
1939     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1940     insertion of callouts before each pattern item. Added the /C option to
1941     pcretest to make use of this.
1943     4. On the advice of a Windows user, the lines
1945     #if defined(_WIN32) || defined(WIN32)
1946     _setmode( _fileno( stdout ), 0x8000 );
1947     #endif /* defined(_WIN32) || defined(WIN32) */
1949     have been added to the source of pcretest. This apparently does useful
1950     magic in relation to line terminators.
1952     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1953     for the benefit of those environments where the "b" makes a difference.
1955     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1956     to know about it. I have put a hack into configure.in that adds in code
1957     to set GCC=yes if CC=icc. This seems to end up at a point in the
1958     generated configure script that is early enough to affect the setting of
1959     compiler options, which is what is needed, but I have no means of testing
1960     whether it really works. (The user who reported this had patched the
1961     generated configure script, which of course I cannot do.)
1963     LATER: After change 22 below (new libtool files), the configure script
1964     seems to know about icc (and also ecc). Therefore, I have commented out
1965     this hack in configure.in.
1967     7. Added support for pkg-config (2 patches were sent in).
1969     8. Negated POSIX character classes that used a combination of internal tables
1970     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1971     [[:^ascii]]. Typically, they would match almost any characters. The other
1972     POSIX classes were not broken in this way.
1974     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1975     to find the match, as PCRE was deluded into thinking that the match had to
1976     start at the start point or following a newline. The same bug applied to
1977     patterns with negative forward assertions or any backward assertions
1978     preceding ".*" at the start, unless the pattern required a fixed first
1979     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1981     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1982     starting at the last subject character, bytes beyond the end of the subject
1983     string were read.
1985     11. Renamed the variable "class" as "classbits" to make life easier for C++
1986     users. (Previously there was a macro definition, but it apparently wasn't
1987     enough.)
1989     12. Added the new field "tables" to the extra data so that tables can be passed
1990     in at exec time, or the internal tables can be re-selected. This allows
1991     a compiled regex to be saved and re-used at a later time by a different
1992     program that might have everything at different addresses.
1994     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1995     -R library as well as a -L library.
1997     14. The debugging options of pcretest (-d on the command line or D on a
1998     pattern) showed incorrect output for anything following an extended class
1999     that contained multibyte characters and which was followed by a quantifier.
2001     15. Added optional support for general category Unicode character properties
2002     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
2003     support. It adds about 90K to the size of the library. The meanings of the
2004     inbuilt class escapes such as \d and \s have NOT been changed.
2006     16. Updated pcredemo.c to include calls to free() to release the memory for the
2007     compiled pattern.
2009     17. The generated file chartables.c was being created in the source directory
2010     instead of in the building directory. This caused the build to fail if the
2011     source directory was different from the building directory, and was
2012     read-only.
2014     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
2015     file. No doubt somebody will tell me if they don't make sense... Also added
2016     Dan Mooney's comments about building on OpenVMS.
2018     19. Added support for partial matching via the PCRE_PARTIAL option for
2019     pcre_exec() and the \P data escape in pcretest.
2021     20. Extended pcretest with 3 new pattern features:
2023     (i) A pattern option of the form ">rest-of-line" causes pcretest to
2024     write the compiled pattern to the file whose name is "rest-of-line".
2025     This is a straight binary dump of the data, with the saved pointer to
2026     the character tables forced to be NULL. The study data, if any, is
2027     written too. After writing, pcretest reads a new pattern.
2029     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2030     compiled pattern from the given file. There must not be any
2031     occurrences of "<" in the file name (pretty unlikely); if there are,
2032     pcretest will instead treat the initial "<" as a pattern delimiter.
2033     After reading in the pattern, pcretest goes on to read data lines as
2034     usual.
2036     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2037     and 16-bit fields in a compiled pattern, to simulate a pattern that
2038     was compiled on a host of opposite endianness.
2040     21. The pcre-exec() function can now cope with patterns that were compiled on
2041     hosts of opposite endianness, with this restriction:
2043     As for any compiled expression that is saved and used later, the tables
2044     pointer field cannot be preserved; the extra_data field in the arguments
2045     to pcre_exec() should be used to pass in a tables address if a value
2046     other than the default internal tables were used at compile time.
2048     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2049     now diagnosed as an error. Previously, most of the time, a negative number
2050     would have been treated as zero, but if in addition "ovector" was passed as
2051     NULL, a crash could occur.
2053     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2054     new versions from the libtool 1.5 distribution (the last one is a copy of
2055     a file called libtool.m4). This seems to have fixed the need to patch
2056     "configure" to support Darwin 1.3 (which I used to do). However, I still
2057     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2058     workstation).
2060     24. Changed the PCRE licence to be the more standard "BSD" licence.
2063 nigel 73 Version 4.5 01-Dec-03
2064     ---------------------
2066     1. There has been some re-arrangement of the code for the match() function so
2067     that it can be compiled in a version that does not call itself recursively.
2068     Instead, it keeps those local variables that need separate instances for
2069     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2070     needs to "recurse". Keeping track of where control must go is done by means
2071     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2072     hide most of the details from the main code, and operates only if
2073     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2074     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2075     operating.
2077     To make it easier for callers to provide specially tailored get/free
2078     functions for this usage, two new functions, pcre_stack_malloc, and
2079     pcre_stack_free, are used. They are always called in strict stacking order,
2080     and the size of block requested is always the same.
2082     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2083     PCRE has been compiled to use the stack or the heap for recursion. The
2084     -C option of pcretest uses this to show which version is compiled.
2086     A new data escape \S, is added to pcretest; it causes the amounts of store
2087     obtained and freed by both kinds of malloc/free at match time to be added
2088     to the output.
2090     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2091     what's available on my current Linux desktop machine.
2093     3. When matching a UTF-8 string, the test for a valid string at the start has
2094     been extended. If start_offset is not zero, PCRE now checks that it points
2095     to a byte that is the start of a UTF-8 character. If not, it returns
2096     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2097     this is necessary because there may be backward assertions in the pattern.
2098     When matching the same subject several times, it may save resources to use
2099     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2101     4. The code for checking the validity of UTF-8 strings has been tightened so
2102     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2103     containing "overlong sequences".
2105     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2106     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2107     should have been "&", but it just so happened that all the cases this let
2108     through by mistake were picked up later in the function.
2110     6. I had used a variable called "isblank" - this is a C99 function, causing
2111     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2113     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2114     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2115     so the version is shown; (c) stop "make test" echoing "./RunTest".
2117     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2119     9. The prototype for memmove() for systems that don't have it was using
2120     size_t, but the inclusion of the header that defines size_t was later. I've
2121     moved the #includes for the C headers earlier to avoid this.
2123     10. Added some adjustments to the code to make it easier to compiler on certain
2124     special systems:
2126     (a) Some "const" qualifiers were missing.
2127     (b) Added the macro EXPORT before all exported functions; by default this
2128     is defined to be empty.
2129     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2130     that it reads its output file name as an argument instead of writing
2131     to the standard output and assuming this can be redirected.
2133     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2134     class containing characters with values greater than 255, PCRE compilation
2135     went into a loop.
2137     12. A recursive reference to a subpattern that was within another subpattern
2138     that had a minimum quantifier of zero caused PCRE to crash. For example,
2139     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2140     recursion. If the recursively-called subpattern itself had a zero repeat,
2141     that was OK.
2143     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2144     buffer into which it was copied (for escape processing) was still set at
2145     1024, so long lines caused crashes.
2147     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2148     "internal error: code overflow...". This applied to any character class
2149     that was followed by a possessive quantifier.
2151     15. Modified the Makefile to add libpcre.la as a prerequisite for
2152     libpcreposix.la because I was told this is needed for a parallel build to
2153     work.
2155     16. If a pattern that contained .* following optional items at the start was
2156     studied, the wrong optimizing data was generated, leading to matching
2157     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2158     matching string must start with a or b or c. The correct conclusion for
2159     this pattern is that a match can start with any character.
2162 nigel 71 Version 4.4 13-Aug-03
2163     ---------------------
2165     1. In UTF-8 mode, a character class containing characters with values between
2166     127 and 255 was not handled correctly if the compiled pattern was studied.
2167     In fixing this, I have also improved the studying algorithm for such
2168     classes (slightly).
2170     2. Three internal functions had redundant arguments passed to them. Removal
2171     might give a very teeny performance improvement.
2173     3. Documentation bug: the value of the capture_top field in a callout is *one
2174     more than* the number of the hightest numbered captured substring.
2176     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2177     in incorrectly linking with a previously installed version. They now link
2178     explicitly with libpcre.la.
2180     5. configure.in no longer needs to recognize Cygwin specially.
2182     6. A problem in pcre.in for Windows platforms is fixed.
2184     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2185     pcretest, it used to include the size of the study block as part of its
2186     output. Unfortunately, the structure contains a field that has a different
2187     size on different hardware architectures. This meant that the tests that
2188     showed this size failed. As the block is currently always of a fixed size,
2189     this information isn't actually particularly useful in pcretest output, so
2190     I have just removed it.
2192     8. Three pre-processor statements accidentally did not start in column 1.
2193     Sadly, there are *still* compilers around that complain, even though
2194     standard C has not required this for well over a decade. Sigh.
2196     9. In pcretest, the code for checking callouts passed small integers in the
2197     callout_data field, which is a void * field. However, some picky compilers
2198     complained about the casts involved for this on 64-bit systems. Now
2199     pcretest passes the address of the small integer instead, which should get
2200     rid of the warnings.
2202     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2203     both compile and run time, and gives an error if an invalid UTF-8 sequence
2204     is found. There is a option for disabling this check in cases where the
2205     string is known to be correct and/or the maximum performance is wanted.
2207     11. In response to a bug report, I changed one line in Makefile.in from
2209     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2210     to
2211     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2213     to look similar to other lines, but I have no way of telling whether this
2214     is the right thing to do, as I do not use Windows. No doubt I'll get told
2215     if it's wrong...
2218 nigel 69 Version 4.3 21-May-03
2219     ---------------------
2221     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2222     Makefile.
2224     2. Some refactoring to improve the quality of the code:
2226     (i) The utf8_table... variables are now declared "const".
2228     (ii) The code for \cx, which used the "case flipping" table to upper case
2229     lower case letters, now just substracts 32. This is ASCII-specific,
2230     but the whole concept of \cx is ASCII-specific, so it seems
2231     reasonable.
2233     (iii) PCRE was using its character types table to recognize decimal and
2234     hexadecimal digits in the pattern. This is silly, because it handles
2235     only 0-9, a-f, and A-F, but the character types table is locale-
2236     specific, which means strange things might happen. A private
2237     table is now used for this - though it costs 256 bytes, a table is
2238     much faster than multiple explicit tests. Of course, the standard
2239     character types table is still used for matching digits in subject
2240     strings against \d.
2242     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2243     ending in _t are). So I've renamed it as ESC_tee.
2245     3. The first argument for regexec() in the POSIX wrapper should have been
2246     defined as "const".
2248     4. Changed pcretest to use malloc() for its buffers so that they can be
2249     Electric Fenced for debugging.
2251     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2252     to read one or more bytes before the start of the subject string. Often this
2253     had no effect on PCRE's behaviour, but in some circumstances it could
2254     provoke a segmentation fault.
2256     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2257     to try to read one or more bytes before the start of the subject string.
2259     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2260     UTF-8 support could misbehave in various ways if the subject string
2261     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2262     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2263     back over UTF-8 characters.)
2266 nigel 67 Version 4.2 14-Apr-03
2267     ---------------------
2269     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2271     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2272     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2273     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2274     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2275     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2276     and BUILD_EXEEXT
2277     Note: automatic setting of the BUILD variables is not yet working
2278     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2279     compile-time but not at link-time
2280     [LINK]: use for linking executables only
2281     make different versions for Windows and non-Windows
2282     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2283     libraries
2284     [LINK_FOR_BUILD]: new variable
2285     [OBJEXT]: use throughout
2286     [EXEEXT]: use throughout
2287     <winshared>: new target
2288     <wininstall>: new target
2289     <dftables.o>: use native compiler
2290     <dftables>: use native linker
2291     <install>: handle Windows platform correctly
2292     <clean>: ditto
2293     <check>: ditto
2294     copy DLL to top builddir before testing
2296     As part of these changes, -no-undefined was removed again. This was reported
2297     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2298     in any case.
2300     3. Some tidies to get rid of compiler warnings:
2302     . In the match_data structure, match_limit was an unsigned long int, whereas
2303     match_call_count was an int. I've made them both unsigned long ints.
2305     . In pcretest the fact that a const uschar * doesn't automatically cast to
2306     a void * provoked a warning.
2308     . Turning on some more compiler warnings threw up some "shadow" variables
2309     and a few more missing casts.
2311     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2312     option, a class that contained a single character with a value between 128
2313     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2315     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2316     option, a class that contained several characters, but with at least one
2317     whose value was between 128 and 255 caused PCRE to crash.
2320 nigel 65 Version 4.1 12-Mar-03
2321     ---------------------
2322 nigel 63
2323 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2324     needed, and a string in dftables.c that was longer than standard compilers are
2325     required to support.
2327     2. Compiling with Sun's compiler found a few more places where the code could
2328     be tidied up in order to avoid warnings.
2330     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2331     first of these names is deprecated in the latest Autoconf in favour of the name
2332     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2333     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2334     analogy I have changed it to CFLAGS_FOR_BUILD.
2336     4. Added -no-undefined to the linking command in the Makefile, because this is
2337     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2338     linking step for the pcreposix library.
2340     5. PCRE was failing to diagnose the case of two named groups with the same
2341     name.
2343     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2344     literal character that is needed in the subject for a match, and scans along to
2345     ensure that it is present before embarking on the full matching process. This
2346     saves time in cases of nested unlimited repeats that are never going to match.
2347     Problem: the scan can take a lot of time if the subject is very long (e.g.
2348     megabytes), thus penalizing straightforward matches. It is now done only if the
2349     amount of subject to be scanned is less than 1000 bytes.
2351     7. A lesser problem with the same optimization is that it was recording the
2352     first character of an anchored pattern as "needed", thus provoking a search
2353     right along the subject, even when the first match of the pattern was going to
2354     fail. The "needed" character is now not set for anchored patterns, unless it
2355     follows something in the pattern that is of non-fixed length. Thus, it still
2356     fulfils its original purpose of finding quick non-matches in cases of nested
2357     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2360     Version 4.0 17-Feb-03
2361     ---------------------
2363 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2364     extended to the end of string, PCRE compiled incorrect data. This could lead to
2365     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2367     2. Moved to autoconf 2.53 and libtool 1.4.2.
2369     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2370     the special perltest8 script is no longer needed - all the tests can be run
2371     from a single perltest script.
2373     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2374     by \s. It has now been removed in PCRE. This means it isn't recognized as
2375     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2376     class [:space:] *does* include VT, thereby creating a mess.
2378     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2379     space and tab.
2381     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2382     its new features into the main test script, reducing the number of scripts.
2384     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2385     were backward compatible, and made the (?i) apply to the whole pattern, as if
2386     /i were given. Now it behaves more logically, and applies the option setting
2387     only to what follows. PCRE has been changed to follow suit. However, if it
2388     finds options settings right at the start of the pattern, it extracts them into
2389     the global options, as before. Thus, they show up in the info data.
2391     8. Added support for the \Q...\E escape sequence. Characters in between are
2392     treated as literals. This is slightly different from Perl in that $ and @ are
2393     also handled as literals inside the quotes. In Perl, they will cause variable
2394     interpolation. Note the following examples:
2396     Pattern PCRE matches Perl matches
2398     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2399     \Qabc\$xyz\E abc\$xyz abc\$xyz
2400     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2402     For compatibility with Perl, \Q...\E sequences are recognized inside character
2403     classes as well as outside them.
2405     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2406     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2407     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2408     signed/unsigned warnings.
2410     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2411     option for pcretest, so I've replaced it by a simple function that does just
2412     that job.
2414     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2415     "pcregrep -".
2417     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2418     Java package. This provides some syntactic sugar for simple cases of what my
2419     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2420     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2421     item, you can use this simplified notation. Note that only makes sense with
2422     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2423     greediness, whatever the setting of the PCRE_UNGREEDY option.
2425     13. A change of greediness default within a pattern was not taking effect at
2426     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2427     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2428     was abstracted outside.
2430     14. PCRE now supports the \G assertion. It is true when the current matching
2431     position is at the start point of the match. This differs from \A when the
2432     starting offset is non-zero. Used with the /g option of pcretest (or similar
2433     code), it works in the same way as it does for Perl's /g option. If all
2434     alternatives of a regex begin with \G, the expression is anchored to the start
2435     match position, and the "anchored" flag is set in the compiled expression.
2437     15. Some bugs concerning the handling of certain option changes within patterns
2438     have been fixed. These applied to options other than (?ims). For example,
2439     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2440     been the other way round. Some of this was related to change 7 above.
2442     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2443     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2444     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2445     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2447     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2448     mode. Unlike ".", it always matches newline, whatever the setting of
2449     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2450     assertions. Perl allows it, but it doesn't (in general) work because it can't
2451     calculate the length of the lookbehind. At least, that's the case for Perl
2452     5.8.0 - I've been told they are going to document that it doesn't work in
2453     future.
2455     18. Added an error diagnosis for escapes that PCRE does not support: these are
2456     \L, \l, \N, \P, \p, \U, \u, and \X.
2458     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2459     reading past the end of the pattern in cases such as /[abcd/.
2461     20. PCRE was getting more memory than necessary for patterns with classes that
2462     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2464     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2465     compiling PCRE for use with Virtual Pascal.
2467     22. Small fix to the Makefile to make it work properly if the build is done
2468     outside the source tree.
2470     23. Added a new extension: a condition to go with recursion. If a conditional
2471     subpattern starts with (?(R) the "true" branch is used if recursion has
2472     happened, whereas the "false" branch is used only at the top level.
2474     24. When there was a very long string of literal characters (over 255 bytes
2475     without UTF support, over 250 bytes with UTF support), the computation of how
2476     much memory was required could be incorrect, leading to segfaults or other
2477     strange effects.
2479     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2480     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2481     there was a subsequent back reference to those brackets. This meant that, for
2482     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2483     possible to check for precisely this case. All we can do is abandon the
2484     optimization if .* occurs inside capturing brackets when there are any back
2485     references whatsoever. (See below for a better fix that came later.)
2487     26. The handling of the optimization for finding the first character of a
2488     non-anchored pattern, and for finding a character that is required later in the
2489     match were failing in some cases. This didn't break the matching; it just
2490     failed to optimize when it could. The way this is done has been re-implemented.
2492     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2494     28. Added a new feature that provides some of the functionality that Perl
2495     provides with (?{...}). The facility is termed a "callout". The way it is done
2496     in PCRE is for the caller to provide an optional function, by setting
2497     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2498     global variable. By default it is unset, which disables all calling out. To get
2499     the function called, the regex must include (?C) at appropriate points. This
2500     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2501     This provides a means of identifying different callout points. When PCRE
2502     reaches such a point in the regex, if pcre_callout has been set, the external
2503     function is called. It is provided with data in a structure called
2504     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2505     matching continues; if it returns a non-zero value, the match at the current
2506     point fails. However, backtracking will occur if possible. [This was changed
2507     later and other features added - see item 49 below.]
2509     29. pcretest is upgraded to test the callout functionality. It provides a
2510     callout function that displays information. By default, it shows the start of
2511     the match and the current position in the text. There are some new data escapes
2512     to vary what happens:
2514     \C+ in addition, show current contents of captured substrings
2515     \C- do not supply a callout function
2516     \C!n return 1 when callout number n is reached
2517     \C!n!m return 1 when callout number n is reached for the mth time
2519     30. If pcregrep was called with the -l option and just a single file name, it
2520     output "<stdin>" if a match was found, instead of the file name.
2522     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2523     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2524     pcre_exec(). This saves a malloc/free per call. The default value of
2525     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2526     when configuring.
2528     32. The default maximum size of a compiled pattern is 64K. There have been a
2529     few cases of people hitting this limit. The code now uses macros to handle the
2530     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2531     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2532     configuring. Tests 2 and 5 work only with 2-byte links because they output
2533     debugging information about compiled patterns.
2535     33. Internal code re-arrangements:
2537     (a) Moved the debugging function for printing out a compiled regex into
2538     its own source file (printint.c) and used #include to pull it into
2539     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2540     separate copies.
2542     (b) Defined the list of op-code names for debugging as a macro in
2543     internal.h so that it is next to the definition of the opcodes.
2545     (c) Defined a table of op-code lengths for simpler skipping along compiled
2546     code. This is again a macro in internal.h so that it is next to the
2547     definition of the opcodes.
2549     34. Added support for recursive calls to individual subpatterns, along the
2550     lines of Robin Houston's patch (but implemented somewhat differently).
2552     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2553     allow it to read and process whole directories in Win32. This code was
2554     contributed by Lionel Fourquaux; it has not been tested by me.
2556     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2557     used to name a group. Names consist of alphanumerics and underscores, and must
2558     be unique. Back references use the syntax (?P=name) and recursive calls use
2559     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2560     numbers. The function pcre_fullinfo() can be used after compilation to extract
2561     a name/number map. There are three relevant calls:
2563     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2564     PCRE_INFO_NAMECOUNT yields the number of entries
2565     PCRE_INFO_NAMETABLE yields a pointer to the map.
2567     The map is a vector of fixed-size entries. The size of each entry depends on
2568     the length of the longest name used. The first two bytes of each entry are the
2569     group number, most significant byte first. There follows the corresponding
2570     name, zero terminated. The names are in alphabetical order.
2572     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2573     case instead of 255. Making it the same both with and without UTF-8 support
2574     means that the same test output works with both.
2576     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2577     calling malloc() with a zero argument.
2579     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2580     optimization. I've improved things by keeping a bitmap of backreferences with
2581     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2582     fact referenced, the optimization can be applied. It is unlikely that a
2583     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2584     the match to follow \n) will appear inside brackets with a number greater than
2585     31, but if it does, any back reference > 31 suppresses the optimization.
2587     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2588     of disabling numbered capturing parentheses. Any opening parenthesis that is
2589     not followed by ? behaves as if it were followed by ?: but named parentheses
2590     can still be used for capturing (and they will acquire numbers in the usual
2591     way).
2593     41. Redesigned the return codes from the match() function into yes/no/error so
2594     that errors can be passed back from deep inside the nested calls. A malloc
2595     failure while inside a recursive subpattern call now causes the
2596     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2598     42. It is now possible to set a limit on the number of times the match()
2599     function is called in a call to pcre_exec(). This facility makes it possible to
2600     limit the amount of recursion and backtracking, though not in a directly
2601     obvious way, because the match() function is used in a number of different
2602     circumstances. The count starts from zero for each position in the subject
2603     string (for non-anchored patterns). The default limit is, for compatibility, a
2604     large number, namely 10 000 000. You can change this in two ways:
2606     (a) When configuring PCRE before making, you can use --with-match-limit=n
2607     to set a default value for the compiled library.
2609     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2610     a different value is set. See 45 below.
2612     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2614     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2615     of things that can be changed at compile time. The first argument specifies
2616     what is wanted and the second points to where the information is to be placed.
2617     The current list of available information is:
2621     The output is an integer that is set to one if UTF-8 support is available;
2622     otherwise it is set to zero.
2626     The output is an integer that it set to the value of the code that is used for
2627     newline. It is either LF (10) or CR (13).
2631     The output is an integer that contains the number of bytes used for internal
2632     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2636     The output is an integer that contains the threshold above which the POSIX
2637     interface uses malloc() for output vectors. See item 31 above.
2641     The output is an unsigned integer that contains the default limit of the number
2642     of match() calls in a pcre_exec() execution. See 42 above.
2644     44. pcretest has been upgraded by the addition of the -C option. This causes it
2645     to extract all the available output from the new pcre_config() function, and to
2646     output it. The program then exits immediately.
2648     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2649     order to support additional features. One way would have been to define
2650     pcre_exec2() (for example) with extra arguments, but this would not have been
2651     extensible, and would also have required all calls to the original function to
2652     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2653     is used for passing in "extra" data from pcre_study().
2655     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2656     contains the following fields:
2658     flags a bitmap indicating which of the following fields are set
2659     study_data opaque data from pcre_study()
2660     match_limit a way of specifying a limit on match() calls for a specific
2661     call to pcre_exec()
2662     callout_data data for callouts (see 49 below)
2664     The flag bits are also defined in pcre.h, and are
2670     The pcre_study() function now returns one of these new pcre_extra blocks, with
2671     the actual study data pointed to by the study_data field, and the
2672     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2673     before. That is, this change is entirely upwards-compatible and requires no
2674     change to existing code.
2676     If you want to pass in additional data to pcre_exec(), you can either place it
2677     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2678     block.
2680     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2681     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2682     times with different match limits, until it finds the minimum value needed for
2683     pcre_exec() to complete. The value is then output. This can be instructive; for
2684     most simple matches the number is quite small, but for pathological cases it
2685     gets very large very quickly.
2687     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2688     returns the size of the data block pointed to by the study_data field in a
2689     pcre_extra block, that is, the value that was passed as the argument to
2690     pcre_malloc() when PCRE was getting memory in which to place the information
2691     created by pcre_study(). The fourth argument should point to a size_t variable.
2692     pcretest has been extended so that this information is shown after a successful
2693     pcre_study() call when information about the compiled regex is being displayed.
2695     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2696     because what follows is always an absolute path. (Later: it turns out that this
2697     is more than cosmetic for MinGW, because it doesn't like empty path
2698     components.)
2700     49. Some changes have been made to the callout feature (see 28 above):
2702     (i) A callout function now has three choices for what it returns:
2704     0 => success, carry on matching
2705     > 0 => failure at this point, but backtrack if possible
2706     < 0 => serious error, return this value from pcre_exec()
2708     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2709     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2710     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2711     use by callout functions. It will never be used by PCRE itself.
2713     (ii) The pcre_extra structure (see 45 above) has a void * field called
2714     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2715     pcre_callout_block structure has a field of the same name. The contents of
2716     the field passed in the pcre_extra structure are passed to the callout
2717     function in the corresponding field in the callout block. This makes it
2718     easier to use the same callout-containing regex from multiple threads. For
2719     testing, the pcretest program has a new data escape
2721     \C*n pass the number n (may be negative) as callout_data
2723     If the callout function in pcretest receives a non-zero value as
2724     callout_data, it returns that value.
2726     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2727     there were some redundant $(CFLAGS) in commands that are now specified as
2728     $(LINK), which already includes $(CFLAGS).
2730     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2731     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2732     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2733     one-byte characters throughout. Note that case-insensitive matching applies
2734     only to characters whose values are less than 256. PCRE doesn't support the
2735     notion of cases for higher-valued characters.
2737     (i) A character class whose characters are all within 0-255 is handled as
2738     a bit map, and the map is inverted for negative classes. Previously, a
2739     character > 255 always failed to match such a class; however it should
2740     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2742     (ii) A negated character class with a single character < 255 is coded as
2743     "not this character" (OP_NOT). This wasn't working properly when the test
2744     character was multibyte, either singly or repeated.
2746     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2747     mode, for example: \x{100}{2,3}.
2749     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2750     singly or repeated) now correctly test multibyte characters. However,
2751     PCRE doesn't recognize any characters with values greater than 255 as
2752     digits, spaces, or word characters. Such characters always match \D, \S,
2753     and \W, and never match \d, \s, or \w.
2755     (v) Classes may now contain characters and character ranges with values
2756     greater than 255. For example: [ab\x{100}-\x{400}].
2758     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2759     PCRE in UTF-8 mode.
2761     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2762     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2763     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2764     value.)
2766     53. The single man page has become too large. I have therefore split it up into
2767     a number of separate man pages. These also give rise to individual HTML pages;
2768     these are now put in a separate directory, and there is an index.html page that
2769     lists them all. Some hyperlinking between the pages has been installed.
2771     54. Added convenience functions for handling named capturing parentheses.
2773     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2774     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2775     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2776     are faulted.
2778     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2779     calling configure. These values are used when compiling the dftables.c program
2780     which is run to generate the source of the default character tables. They
2781     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2782     you will need to set these values.
2784     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2787     Version 3.9 02-Jan-02
2788 nigel 61 ---------------------
2790     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2792     2. If --disable-static was given, the building process failed when trying to
2793     build pcretest and pcregrep. (For some reason it was using libtool to compile
2794     them, which is not right, as they aren't part of the library.)
2797 nigel 59 Version 3.8 18-Dec-01
2798     ---------------------
2800     1. The experimental UTF-8 code was completely screwed up. It was packing the
2801     bytes in the wrong order. How dumb can you get?
2804 nigel 57 Version 3.7 29-Oct-01
2805     ---------------------
2807     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2808     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2809     this didn't happen under Solaris 8, where I normally test things.
2811 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2812     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2813     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2814     this fix an hour or so after the initial 3.7 release.)
2815 nigel 57
2816 nigel 59
2817 nigel 55 Version 3.6 23-Oct-01
2818     ---------------------
2820     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2821     offsets passed as NULL with zero offset count.
2823     2. The config.guess and config.sub files had not been updated when I moved to
2824     the latest autoconf.
2827 nigel 53 Version 3.5 15-Aug-01
2828     ---------------------
2829 nigel 5
2830 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2831     had been forgotten.
2833     2. By using declared but undefined structures, we can avoid using "void"
2834     definitions in pcre.h while keeping the internal definitions of the structures
2835     private.
2837     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2838     user point of view, this means that both static and shared libraries are built
2839     by default, but this can be individually controlled. More of the work of
2840     handling this static/shared cases is now inside libtool instead of PCRE's make
2841     file.
2843     4. The pcretest utility is now installed along with pcregrep because it is
2844     useful for users (to test regexs) and by doing this, it automatically gets
2845     relinked by libtool. The documentation has been turned into a man page, so
2846     there are now .1, .txt, and .html versions in /doc.
2848     5. Upgrades to pcregrep:
2849     (i) Added long-form option names like gnu grep.
2850     (ii) Added --help to list all options with an explanatory phrase.
2851     (iii) Added -r, --recursive to recurse into sub-directories.
2852     (iv) Added -f, --file to read patterns from a file.
2854     6. pcre_exec() was referring to its "code" argument before testing that
2855     argument for NULL (and giving an error if it was NULL).
2857     7. Upgraded Makefile.in to allow for compiling in a different directory from
2858     the source directory.
2860     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2861     options bits, the pointer it was passed was to an int instead of to an unsigned
2862     long int. This mattered only on 64-bit systems.
2864     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2865     generated) instead of pcre.in, which it its source. Also made the same change
2866     in several of the .c files.
2868     10. A new release of gcc defines printf() as a macro, which broke pcretest
2869     because it had an ifdef in the middle of a string argument for printf(). Fixed
2870     by using separate calls to printf().
2872     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2873     script, to force use of CR or LF instead of \n in the source. On non-Unix
2874     systems, the value can be set in config.h.
2876     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2877     absolute limit. Changed the text of the error message to make this clear, and
2878     likewise updated the man page.
2880     13. The limit of 99 on the number of capturing subpatterns has been removed.
2881     The new limit is 65535, which I hope will not be a "real" limit.
2884 nigel 51 Version 3.4 22-Aug-00
2885     ---------------------
2887     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2889     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2892 nigel 49 Version 3.3 01-Aug-00
2893     ---------------------
2895     1. If an octal character was given, but the value was greater than \377, it
2896     was not getting masked to the least significant bits, as documented. This could
2897     lead to crashes in some systems.
2899     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2900     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2902     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2903     These just pass their arguments on to (pcre_free)(), but they are provided
2904     because some uses of PCRE bind it to non-C systems that can call its functions,
2905     but cannot call free() or pcre_free() directly.
2907     4. Add "make test" as a synonym for "make check". Corrected some comments in
2908     the Makefile.
2910     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2911     Makefile.
2913     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2914     command called pgrep for grepping around the active processes.
2916     7. Added the beginnings of support for UTF-8 character strings.
2918     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2919     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2920     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2921     out for the ar command.)
2924 nigel 47 Version 3.2 12-May-00
2925     ---------------------
2927     This is purely a bug fixing release.
2929     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2930     of ZA. This was just one example of several cases that could provoke this bug,
2931     which was introduced by change 9 of version 2.00. The code for breaking
2932     infinite loops after an iteration that matches an empty string was't working
2933     correctly.
2935     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2936     when matched against abbab (for example). After matching an empty string, it
2937     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2938     caused it to match further down the string than it should.
2940     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2941     was there because it doesn't seem to be needed, and it causes trouble on some
2942     systems, as it is not a Standard C header. It has been removed.
2944     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2945     were reported on the Macintosh. The changes were from
2947     while ((c = *(++ptr)) != 0 && c != '\n');
2948     to
2949     while ((c = *(++ptr)) != 0 && c != '\n') ;
2951     Totally extraordinary, but if that's what it takes...
2953     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2954     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2955     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2956     assumes the way PCRE uses memmove() (always moving upwards).
2958     6. PCRE is being used in one environment where strchr() is not available. There
2959     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2960     faster code anyway.
2963 nigel 45 Version 3.1 09-Feb-00
2964     ---------------------
2966     The only change in this release is the fixing of some bugs in Makefile.in for
2967     the "install" target:
2969     (1) It was failing to install pcreposix.h.
2971     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2974 nigel 43 Version 3.0 01-Feb-00
2975     ---------------------
2976 nigel 41
2977     1. Add support for the /+ modifier to perltest (to output $` like it does in
2978     pcretest).
2980     2. Add support for the /g modifier to perltest.
2982     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2983     matches null strings.
2985     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2986     pattern. Perl treats empty patterns specially - it reuses the most recent
2987     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2988     effect.
2990     5. The POSIX interface was broken in that it was just handing over the POSIX
2991     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2992     required a bigger vector, with some working space on the end. This means that
2993     the POSIX wrapper now has to get and free some memory, and copy the results.
2995 nigel 43 6. Added some simple autoconf support, placing the test data and the
2996     documentation in separate directories, re-organizing some of the
2997     information files, and making it build pcre-config (a GNU standard). Also added
2998     libtool support for building PCRE as a shared library, which is now the
2999     default.
3000 nigel 41
3001 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
3002     09 are not valid octal constants. Single digits will be used for minor values
3003     less than 10.
3005     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
3006     existing programs that set these in the POSIX interface can use PCRE without
3007     modification.
3009     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
3010     return all that pcre_info() returns, plus additional data. The pcre_info()
3011     function is retained for compatibility, but is considered to be obsolete.
3013     10. Added experimental recursion feature (?R) to handle one common case that
3014     Perl 5.6 will be able to do with (?p{...}).
3016     11. Added support for POSIX character classes like [:alpha:], which Perl is
3017     adopting.
3020 nigel 39 Version 2.08 31-Aug-99
3021     ----------------------
3023     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
3024     trying to match at the startoffset position, but instead was moving forward to
3025     the next newline as if a previous match had failed.
3027     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3028     and could get into a loop if a null string was matched other than at the start
3029     of the subject.
3031     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3032     be distinguished at compile time, and for completeness also added PCRE_DATE.
3034     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3035     in GnuWin32 environments.
3038 nigel 37 Version 2.07 29-Jul-99
3039     ----------------------
3041     1. The documentation is now supplied in plain text form and HTML as well as in
3042     the form of man page sources.
3044     2. C++ compilers don't like assigning (void *) values to other pointer types.
3045     In particular this affects malloc(). Although there is no problem in Standard
3046     C, I've put in casts to keep C++ compilers happy.
3048     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3049     should be (const char *).
3051     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3052     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3053     However, I haven't made this a standard facility. The documentation doesn't
3054     mention it, and the Makefile doesn't support it.
3056     5. The Makefile now contains an "install" target, with editable destinations at
3057     the top of the file. The pcretest program is not installed.
3059     6. pgrep -V now gives the PCRE version number and date.
3061     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3062     causing the entire string to be ignored, instead of just the last character.
3064     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3065     non-matching string, it can take a very, very long time, even for strings of
3066     quite modest length, because of the nested recursion. PCRE now does better in
3067     some of these cases. It does this by remembering the last required literal
3068     character in the pattern, and pre-searching the subject to ensure it is present
3069     before running the real match. In other words, it applies a heuristic to detect
3070     some types of certain failure quickly, and in the above example, if presented
3071     with a string that has no trailing " it gives "no match" very quickly.
3073     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3074     other alternatives are tried instead.
3077 nigel 35 Version 2.06 09-Jun-99
3078     ----------------------
3080     1. Change pcretest's output for amount of store used to show just the code
3081     space, because the remainder (the data block) varies in size between 32-bit and
3082     64-bit systems.
3084     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3085     start matching at. This allows lookbehinds to work when searching for multiple
3086     occurrences in a string.
3088     3. Added additional options to pcretest for testing multiple occurrences:
3090     /+ outputs the rest of the string that follows a match
3091     /g loops for multiple occurrences, using the new startoffset argument
3092     /G loops for multiple occurrences by passing an incremented pointer
3094     4. PCRE wasn't doing the "first character" optimization for patterns starting
3095     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3096     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3097     the letter 'x'. On long subject strings, this gives a significant speed-up.
3100 nigel 33 Version 2.05 21-Apr-99
3101     ----------------------
3103     1. Changed the type of magic_number from int to long int so that it works
3104     properly on 16-bit systems.
3106     2. Fixed a bug which caused patterns starting with .* not to work correctly
3107     when the subject string contained newline characters. PCRE was assuming
3108     anchoring for such patterns in all cases, which is not correct because .* will
3109     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3110     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3111     must be retried after every newline in the subject.
3114 nigel 31 Version 2.04 18-Feb-99
3115     ----------------------
3117     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3118     computation of the store needed to hold the pattern was incorrect (too large).
3119     If such patterns were nested a few deep, this could multiply and become a real
3120     problem.
3122     2. Added /M option to pcretest to show the memory requirement of a specific
3123     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3125     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3126     compiled in such a way that the backtracking after subsequent failure was
3127     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3128     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3131 nigel 29 Version 2.03 02-Feb-99
3132     ----------------------
3134     1. Fixed typo and small mistake in man page.
3136 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3137     LICENCE file containing the conditions.
3138 nigel 29
3139     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3140     Perl, that is the internal \ allows the delimiter to be included in the
3141     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3142     the final delimiter, add \ to the end of the pattern (to test the error).
3144     4. Added the convenience functions for extracting substrings after a successful
3145     match. Updated pcretest to make it able to test these functions.
3148 nigel 27 Version 2.02 14-Jan-99
3149     ----------------------
3151     1. Initialized the working variables associated with each extraction so that
3152     their saving and restoring doesn't refer to uninitialized store.
3154     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3155     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3156     fix the problem.
3158     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3159     calls, and wasn't printing the correct value for compiling calls. Increased the
3160     default value of LOOPREPEAT, and the number of significant figures in the
3161     times.
3163     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3165     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3166     a building problem on Windows NT with a FAT file system.
3169 nigel 25 Version 2.01 21-Oct-98
3170     ----------------------
3172     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3173     to character tables built by pcre_maketables() in the current locale. If NULL
3174     is passed, the default tables are used.
3177 nigel 23 Version 2.00 24-Sep-98
3178 nigel 21 ----------------------
3180 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3181     it any more.
3183     2. Allow quantification of (?>) groups, and make it work correctly.
3185     3. The first character computation wasn't working for (?>) groups.
3187     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3188     end of the subject) and add 5.005's \z, which really does match only at the
3189     very end of the subject.
3191     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3193     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3194     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3195     localized options. All options to pcre_study() were also removed.
3197     7. Add other new features from 5.005:
3199     $(?<= positive lookbehind
3200     $(?<! negative lookbehind
3201     (?imsx-imsx) added the unsetting capability
3202     such a setting is global if at outer level; local otherwise
3203     (?imsx-imsx:) non-capturing groups with option setting
3204     (?(cond)re|re) conditional pattern matching
3206     A backreference to itself in a repeated group matches the previous
3207     captured string.
3209     8. General tidying up of studying (both automatic and via "study")
3210     consequential on the addition of new assertions.
3212     9. As in 5.005, unlimited repeated groups that could match an empty substring
3213     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3214     runtime if any iteration does actually match an empty substring.
3216     10. Include the RunTest script in the distribution.
3218     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3219     discrepancies, some of which were old and were also with respect to 5.004. They
3220     have now been fixed.
3223     Version 1.09 28-Apr-98
3224     ----------------------
3226 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3227     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3228     program crashes, or just wrong answers. This did not apply to negated classes
3229     containing more than one character, or to minima other than one.
3232 nigel 19 Version 1.08 27-Mar-98
3233     ----------------------
3235     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3237     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3238     latter must appear before anything that relies on it in the pattern.
3241 nigel 17 Version 1.07 16-Feb-98
3242     ----------------------
3244     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3245     repeat of a potentially empty string).
3248 nigel 15 Version 1.06 23-Jan-98
3249     ----------------------
3251     1. Added Markus Oberhumer's little patches for C++.
3253     2. Literal strings longer than 255 characters were broken.
3256 nigel 13 Version 1.05 23-Dec-97
3257     ----------------------
3259     1. Negated character classes containing more than one character were failing if
3260     PCRE_CASELESS was set at run time.
3263 nigel 11 Version 1.04 19-Dec-97
3264     ----------------------
3266     1. Corrected the man page, where some "const" qualifiers had been omitted.
3268     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3269     input syntax.
3271     3. Fixed memory leak which occurred when a regex with back references was
3272     matched with an offsets vector that wasn't big enough. The temporary memory
3273     that is used in this case wasn't being freed if the match failed.
3275     4. Tidied pcretest to ensure it frees memory that it gets.
3277     5. Temporary memory was being obtained in the case where the passed offsets
3278     vector was exactly big enough.
3280     6. Corrected definition of offsetof() from change 5 below.
3282     7. I had screwed up change 6 below and broken the rules for the use of
3283     setjmp(). Now fixed.
3286 nigel 9 Version 1.03 18-Dec-97
3287     ----------------------
3289     1. A erroneous regex with a missing opening parenthesis was correctly
3290     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3291     on some systems.
3293     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3294     it was reported that one broken compiler failed on the former because "code" is
3295     also an independent variable.
3297     3. The erroneous regex a[]b caused an array overrun reference.
3299     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3300     fail on data ending with that character. (It was going on too far, and checking
3301     the next character, typically a binary zero.) This was specific to the
3302     optimized code for single-character negative classes.
3304     5. Added a contributed patch from the TIN world which does the following:
3306     + Add an undef for memmove, in case the the system defines a macro for it.
3308     + Add a definition of offsetof(), in case there isn't one. (I don't know
3309     the reason behind this - offsetof() is part of the ANSI standard - but
3310     it does no harm).
3312     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3313     most of the places where whitespace preceded '#'. I have given up and
3314     allowed the remaining 2 cases to be at the margin.
3316     + Rename some variables in pcre to eliminate shadowing. This seems very
3317     pedantic, but does no harm, of course.
3319     6. Moved the call to setjmp() into its own function, to get rid of warnings
3320     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3322     7. Constructs such as \d{8,} were compiling into the equivalent of
3323 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3324 nigel 9 outcome, but in this particular case used more store than had been allocated,
3325     which caused the bug to be discovered because it threw up an internal error.
3327     8. The debugging code in both pcre and pcretest for outputting the compiled
3328     form of a regex was going wrong in the case of back references followed by
3329     curly-bracketed repeats.
3332 nigel 7 Version 1.02 12-Dec-97
3333     ----------------------
3335     1. Typos in pcre.3 and comments in the source fixed.
3337     2. Applied a contributed patch to get rid of places where it used to remove
3338     'const' from variables, and fixed some signed/unsigned and uninitialized
3339     variable warnings.
3341     3. Added the "runtest" target to Makefile.
3343     4. Set default compiler flag to -O2 rather than just -O.
3346 nigel 5 Version 1.01 19-Nov-97
3347     ----------------------
3349     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3350     like /([ab]*)*/, that is, for classes with more than one character in them.
3352     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3353     as /((?>a*))*/ (a PCRE_EXTRA facility).
3356     Version 1.00 18-Nov-97
3357     ----------------------
3359     1. Added compile-time macros to support systems such as SunOS4 which don't have
3360     memmove() or strerror() but have other things that can be used instead.
3362     2. Arranged that "make clean" removes the executables.
3365 nigel 3 Version 0.99 27-Oct-97
3366     ----------------------
3368     1. Fixed bug in code for optimizing classes with only one character. It was
3369     initializing a 32-byte map regardless, which could cause it to run off the end
3370     of the memory it had got.
3372     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3375     Version 0.98 22-Oct-97
3376     ----------------------
3378     1. Fixed bug in code for handling temporary memory usage when there are more
3379     back references than supplied space in the ovector. This could cause segfaults.
3382     Version 0.97 21-Oct-97
3383     ----------------------
3385     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3387     2. Optimized negated single characters not to use a bit map.
3389     3. Brought error texts together as macro definitions; clarified some of them;
3390     fixed one that was wrong - it said "range out of order" when it meant "invalid
3391     escape sequence".
3393     4. Changed some char * arguments to const char *.
3395     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3397     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3398     pcretest.
3401     Version 0.96 16-Oct-97
3402     ----------------------
3404     1. Added a simple "pgrep" utility to the distribution.
3406     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3407     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3408     where "ddd" means "one or more decimal digits".
3410     3. Fixed serious bug. If a pattern had a back reference, but the call to
3411     pcre_exec() didn't supply a large enough ovector to record the related
3412     identifying subpattern, the match always failed. PCRE now remembers the number
3413     of the largest back reference, and gets some temporary memory in which to save
3414     the offsets during matching if necessary, in order to ensure that
3415     backreferences always work.
3417     4. Increased the compatibility with Perl in a number of ways:
3419     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3420     to request this handling. The option can be set at compile or exec time.
3422     (b) $ matches before a terminating newline by default; an option
3423     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3424     mode). The option can be set at compile or exec time.
3426     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3427     the same as Perl's. If the decimal number it represents is less than 10
3428     or there aren't that many previous left capturing parentheses, an octal
3429     escape is read. Inside a character class, it's always an octal escape,
3430     even if it is a single digit.
3432     (d) An escaped but undefined alphabetic character is taken as a literal,
3433     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3434     escapes.
3436     (e) {0} is now permitted. (The previous item is removed from the compiled
3437     pattern).
3439     5. Changed all the names of code files so that the basic parts are no longer
3440     than 10 characters, and abolished the teeny "globals.c" file.
3442     6. Changed the handling of character classes; they are now done with a 32-byte
3443     bit map always.
3445     7. Added the -d and /D options to pcretest to make it possible to look at the
3446     internals of compilation without having to recompile pcre.
3449     Version 0.95 23-Sep-97
3450     ----------------------
3452     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3453     \x20 at the start of a run of normal characters. These were being treated as
3454     real characters, instead of the source characters being re-checked.
3457     Version 0.94 18-Sep-97
3458     ----------------------
3460     1. The functions are now thread-safe, with the caveat that the global variables
3461     containing pointers to malloc() and free() or alternative functions are the
3462     same for all threads.
3464     2. Get pcre_study() to generate a bitmap of initial characters for non-
3465     anchored patterns when this is possible, and use it if passed to pcre_exec().
3468     Version 0.93 15-Sep-97
3469     ----------------------
3471     1. /(b)|(:+)/ was computing an incorrect first character.
3473     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3474     but not actually doing anything yet.
3476     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3477     as Perl does (e.g. [-az] or [az-]).
3479     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3480     all possible positions.
3482     5. Split up into different modules to avoid including unneeded functions in a
3483     compiled binary. However, compile and exec are still in one module. The "study"
3484     function is split off.
3486     6. The character tables are now in a separate module whose source is generated
3487     by an auxiliary program - but can then be edited by hand if required. There are
3488     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3489     toupper() in the code.
3491     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3492     make them global. Abolish the function for setting them, as the caller can now
3493     set them directly.
3496     Version 0.92 11-Sep-97
3497     ----------------------
3499     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3500     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3502     2. Caseless matching was not working in character classes if the characters in
3503     the pattern were in upper case.
3505     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3507     4. Make PCRE_ANCHORED public and accept as a compile option.
3509     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3510     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3511     pass them.
3513     6. Give an error if bad option bits passed at compile or run time.
3515     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3516     pcretest to cause it to pass that flag.
3518     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3519     options, and the first character, if set.
3521     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3524     Version 0.91 10-Sep-97
3525     ----------------------
3527     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3528     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3530     2. PCRE was looping on encountering an indefinitely repeated back reference to
3531     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3532     Perl does - treats the match as successful.
3534     ****


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