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Revision 413 - (hide annotations) (download)
Sat Apr 11 11:41:52 2009 UTC (5 years, 4 months ago) by ph10
File size: 165585 byte(s)
CMake: arrange for release type compiler flags to be shown in the summary.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 412 Version 7.9 11-Apr-09
5 ph10 376 ---------------------
6    
7 ph10 392 1. When building with support for bzlib/zlib (pcregrep) and/or readline
8 ph10 376 (pcretest), all targets were linked against these libraries. This included
9     libpcre, libpcreposix, and libpcrecpp, even though they do not use these
10     libraries. This caused unwanted dependencies to be created. This problem
11 ph10 392 has been fixed, and now only pcregrep is linked with bzlib/zlib and only
12 ph10 376 pcretest is linked with readline.
13 ph10 392
14 ph10 376 2. The "typedef int BOOL" in pcre_internal.h that was included inside the
15     "#ifndef FALSE" condition by an earlier change (probably 7.8/18) has been
16     moved outside it again, because FALSE and TRUE are already defined in AIX,
17     but BOOL is not.
18 ph10 392
19     3. The pcre_config() function was treating the PCRE_MATCH_LIMIT and
20 ph10 409 PCRE_MATCH_LIMIT_RECURSION values as ints, when they should be long ints.
21 ph10 392
22 ph10 376 4. The pcregrep documentation said spaces were inserted as well as colons (or
23     hyphens) following file names and line numbers when outputting matching
24 ph10 392 lines. This is not true; no spaces are inserted. I have also clarified the
25 ph10 376 wording for the --colour (or --color) option.
26 ph10 392
27 ph10 378 5. In pcregrep, when --colour was used with -o, the list of matching strings
28     was not coloured; this is different to GNU grep, so I have changed it to be
29     the same.
30 ph10 392
31 ph10 378 6. When --colo(u)r was used in pcregrep, only the first matching substring in
32 ph10 392 each matching line was coloured. Now it goes on to look for further matches
33     of any of the test patterns, which is the same behaviour as GNU grep.
34    
35     7. A pattern that could match an empty string could cause pcregrep to loop; it
36     doesn't make sense to accept an empty string match in pcregrep, so I have
37 ph10 379 locked it out (using PCRE's PCRE_NOTEMPTY option). By experiment, this
38     seems to be how GNU grep behaves.
39 ph10 392
40 ph10 380 8. The pattern (?(?=.*b)b|^) was incorrectly compiled as "match must be at
41 ph10 392 start or after a newline", because the conditional assertion was not being
42     correctly handled. The rule now is that both the assertion and what follows
43     in the first alternative must satisfy the test.
44    
45 ph10 405 9. If auto-callout was enabled in a pattern with a conditional group whose
46 ph10 399 condition was an assertion, PCRE could crash during matching, both with
47     pcre_exec() and pcre_dfa_exec().
48 ph10 392
49     10. The PCRE_DOLLAR_ENDONLY option was not working when pcre_dfa_exec() was
50     used for matching.
51    
52     11. Unicode property support in character classes was not working for
53 ph10 385 characters (bytes) greater than 127 when not in UTF-8 mode.
54 ph10 388
55 ph10 392 12. Added the -M command line option to pcretest.
56    
57 ph10 388 14. Added the non-standard REG_NOTEMPTY option to the POSIX interface.
58 ph10 389
59     15. Added the PCRE_NO_START_OPTIMIZE match-time option.
60 ph10 390
61 ph10 392 16. Added comments and documentation about mis-use of no_arg in the C++
62 ph10 390 wrapper.
63 ph10 392
64 ph10 391 17. Implemented support for UTF-8 encoding in EBCDIC environments, a patch
65 ph10 392 from Martin Jerabek that uses macro names for all relevant character and
66 ph10 391 string constants.
67 ph10 405
68 ph10 393 18. Added to pcre_internal.h two configuration checks: (a) If both EBCDIC and
69     SUPPORT_UTF8 are set, give an error; (b) If SUPPORT_UCP is set without
70 ph10 405 SUPPORT_UTF8, define SUPPORT_UTF8. The "configure" script handles both of
71     these, but not everybody uses configure.
72    
73     19. A conditional group that had only one branch was not being correctly
74     recognized as an item that could match an empty string. This meant that an
75     enclosing group might also not be so recognized, causing infinite looping
76     (and probably a segfault) for patterns such as ^"((?(?=[a])[^"])|b)*"$
77     with the subject "ab", where knowledge that the repeated group can match
78 ph10 396 nothing is needed in order to break the loop.
79 ph10 405
80 ph10 397 20. If a pattern that was compiled with callouts was matched using pcre_dfa_
81 ph10 405 exec(), but without supplying a callout function, matching went wrong.
82    
83     21. If PCRE_ERROR_MATCHLIMIT occurred during a recursion, there was a memory
84     leak if the size of the offset vector was greater than 30. When the vector
85     is smaller, the saved offsets during recursion go onto a local stack
86     vector, but for larger vectors malloc() is used. It was failing to free
87     when the recursion yielded PCRE_ERROR_MATCH_LIMIT (or any other "abnormal"
88 ph10 400 error, in fact).
89 ph10 405
90 ph10 402 22. There was a missing #ifdef SUPPORT_UTF8 round one of the variables in the
91 ph10 405 heapframe that is used only when UTF-8 support is enabled. This caused no
92     problem, but was untidy.
93 ph10 376
94 ph10 405 23. Steven Van Ingelgem's patch to CMakeLists.txt to change the name
95     CMAKE_BINARY_DIR to PROJECT_BINARY_DIR so that it works when PCRE is
96     included within another project.
97 ph10 411
98 ph10 407 24. Steven Van Ingelgem's patches to add more options to the CMake support,
99     slightly modified by me:
100 ph10 411
101     (a) PCRE_BUILD_TESTS can be set OFF not to build the tests, including
102     not building pcregrep.
103    
104 ph10 407 (b) PCRE_BUILD_PCREGREP can be see OFF not to build pcregrep, but only
105 ph10 411 if PCRE_BUILD_TESTS is also set OFF, because the tests use pcregrep.
106    
107 ph10 408 25. Forward references, both numeric and by name, in patterns that made use of
108     duplicate group numbers, could behave incorrectly or give incorrect errors,
109     because when scanning forward to find the reference group, PCRE was not
110     taking into account the duplicate group numbers. A pattern such as
111     ^X(?3)(a)(?|(b)|(q))(Y) is an example.
112 ph10 411
113     26. Changed a few more instances of "const unsigned char *" to USPTR, making
114     the feature of a custom pointer more persuasive (as requested by a user).
115 ph10 409
116 ph10 411 27. Wrapped the definitions of fileno and isatty for Windows, which appear in
117     pcretest.c, inside #ifndefs, because it seems they are sometimes already
118     pre-defined.
119 ph10 412
120     28. Added support for (*UTF8) at the start of a pattern.
121 ph10 392
122 ph10 413 29. Arrange for flags added by the "release type" setting in CMake to be shown
123     in the configuration summary.
124 ph10 405
125 ph10 411
126 ph10 374 Version 7.8 05-Sep-08
127 ph10 349 ---------------------
128    
129     1. Replaced UCP searching code with optimized version as implemented for Ad
130     Muncher (http://www.admuncher.com/) by Peter Kankowski. This uses a two-
131 ph10 351 stage table and inline lookup instead of a function, giving speed ups of 2
132     to 5 times on some simple patterns that I tested. Permission was given to
133     distribute the MultiStage2.py script that generates the tables (it's not in
134     the tarball, but is in the Subversion repository).
135 ph10 349
136 ph10 351 2. Updated the Unicode datatables to Unicode 5.1.0. This adds yet more
137     scripts.
138 ph10 358
139 ph10 353 3. Change 12 for 7.7 introduced a bug in pcre_study() when a pattern contained
140     a group with a zero qualifier. The result of the study could be incorrect,
141 ph10 358 or the function might crash, depending on the pattern.
142    
143     4. Caseless matching was not working for non-ASCII characters in back
144 ph10 354 references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
145 ph10 358 It now works when Unicode Property Support is available.
146    
147 ph10 355 5. In pcretest, an escape such as \x{de} in the data was always generating
148     a UTF-8 string, even in non-UTF-8 mode. Now it generates a single byte in
149     non-UTF-8 mode. If the value is greater than 255, it gives a warning about
150 ph10 358 truncation.
151 ph10 349
152 ph10 358 6. Minor bugfix in pcrecpp.cc (change "" == ... to NULL == ...).
153    
154 ph10 357 7. Added two (int) casts to pcregrep when printing the difference of two
155     pointers, in case they are 64-bit values.
156 ph10 371
157     8. Added comments about Mac OS X stack usage to the pcrestack man page and to
158     test 2 if it fails.
159    
160 ph10 359 9. Added PCRE_CALL_CONVENTION just before the names of all exported functions,
161 ph10 371 and a #define of that name to empty if it is not externally set. This is to
162     allow users of MSVC to set it if necessary.
163    
164     10. The PCRE_EXP_DEFN macro which precedes exported functions was missing from
165 ph10 359 the convenience functions in the pcre_get.c source file.
166 ph10 371
167 ph10 360 11. An option change at the start of a pattern that had top-level alternatives
168     could cause overwriting and/or a crash. This command provoked a crash in
169 ph10 371 some environments:
170    
171     printf "/(?i)[\xc3\xa9\xc3\xbd]|[\xc3\xa9\xc3\xbdA]/8\n" | pcretest
172    
173 ph10 360 This potential security problem was recorded as CVE-2008-2371.
174 ph10 371
175 ph10 361 12. For a pattern where the match had to start at the beginning or immediately
176     after a newline (e.g /.*anything/ without the DOTALL flag), pcre_exec() and
177 ph10 371 pcre_dfa_exec() could read past the end of the passed subject if there was
178 ph10 361 no match. To help with detecting such bugs (e.g. with valgrind), I modified
179     pcretest so that it places the subject at the end of its malloc-ed buffer.
180 ph10 371
181 ph10 364 13. The change to pcretest in 12 above threw up a couple more cases when pcre_
182 ph10 371 exec() might read past the end of the data buffer in UTF-8 mode.
183    
184 ph10 364 14. A similar bug to 7.3/2 existed when the PCRE_FIRSTLINE option was set and
185 ph10 371 the data contained the byte 0x85 as part of a UTF-8 character within its
186     first line. This applied both to normal and DFA matching.
187    
188 ph10 366 15. Lazy qualifiers were not working in some cases in UTF-8 mode. For example,
189 ph10 371 /^[^d]*?$/8 failed to match "abc".
190 ph10 351
191 ph10 371 16. Added a missing copyright notice to pcrecpp_internal.h.
192    
193     17. Make it more clear in the documentation that values returned from
194 ph10 368 pcre_exec() in ovector are byte offsets, not character counts.
195 ph10 357
196 ph10 371 18. Tidied a few places to stop certain compilers from issuing warnings.
197 ph10 368
198 ph10 373 19. Updated the Virtual Pascal + BCC files to compile the latest v7.7, as
199     supplied by Stefan Weber. I made a further small update for 7.8 because
200 ph10 374 there is a change of source arrangements: the pcre_searchfuncs.c module is
201     replaced by pcre_ucd.c.
202 ph10 371
203 ph10 373
204 ph10 347 Version 7.7 07-May-08
205 ph10 321 ---------------------
206    
207     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
208 ph10 345 a string to a long long, pretend we don't even have a long long." This is
209 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
210 ph10 345
211 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
212     pre-7.6 versions, which defined a global no_arg variable instead of putting
213 ph10 332 it in the RE class. (See also #8 below.)
214 ph10 345
215     3. Remove a line of dead code, identified by coverity and reported by Nuno
216     Lopes.
217    
218 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
219 ph10 321
220 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
221 ph10 345 of files, instead of just to the final components.
222    
223 ph10 324 (2) If there was more than one level of directory, the subdirectories were
224     skipped unless they satisfied the include/exclude conditions. This is
225     inconsistent with GNU grep (and could even be seen as contrary to the
226     pcregrep specification - which I improved to make it absolutely clear).
227     The action now is always to scan all levels of directory, and just
228     apply the include/exclude patterns to regular files.
229 ph10 345
230 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
231 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
232    
233 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
234 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
235 ph10 326 doesn't support NULs in patterns.
236 ph10 345
237     7. Added some missing "const"s to declarations of static tables in
238     pcre_compile.c and pcre_dfa_exec.c.
239    
240 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
241 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
242 ph10 345 first patch. And a third patch - this was a messy problem.)
243 ph10 321
244 ph10 345 9. Applied Craig's patch to remove the use of push_back().
245    
246 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
247     matching function regexec().
248 ph10 345
249     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
250     which, however, unlike Perl's \g{...}, are subroutine calls, not back
251 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
252     Oniguruma does).
253 ph10 345
254     12. Previously, a group with a zero repeat such as (...){0} was completely
255 ph10 335 omitted from the compiled regex. However, this means that if the group
256     was called as a subroutine from elsewhere in the pattern, things went wrong
257 ph10 345 (an internal error was given). Such groups are now left in the compiled
258     pattern, with a new opcode that causes them to be skipped at execution
259 ph10 335 time.
260 ph10 345
261 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
262     to the way PCRE behaves:
263 ph10 345
264 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
265 ph10 345
266     (b) A back reference to an unmatched subpattern matches an empty string
267 ph10 336 (Perl fails the current match path).
268 ph10 345
269 ph10 341 (c) A data ] in a character class must be notated as \] because if the
270 ph10 345 first data character in a class is ], it defines an empty class. (In
271 ph10 341 Perl it is not possible to have an empty class.) The empty class []
272     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
273     The negative empty class [^] matches any one character, independently
274     of the DOTALL setting.
275 ph10 345
276     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
277 ph10 340 non-existent subpattern following a character class starting with ']' and
278     containing () gave an internal compiling error instead of "reference to
279     non-existent subpattern". Fortunately, when the pattern did exist, the
280 ph10 345 compiled code was correct. (When scanning forwards to check for the
281 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
282 ph10 345 the class, so got the count wrong. When actually compiling, the reference
283 ph10 340 was subsequently set up correctly.)
284 ph10 345
285 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
286 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
287     other assertions are supported. I have made pcre_dfa_exec() support
288     (*FAIL).
289    
290 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
291 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
292     cannot be changed at match time, I realized I could make a small
293     improvement to matching performance by compiling OP_ALLANY instead of
294     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
295     on the OP_ANY path.
296    
297     17. Compiling pcretest on Windows with readline support failed without the
298 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
299 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
300    
301 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
302 ph10 345 ncurses library to be included for pcretest when ReadLine support is
303     requested, but also to allow for it to be overridden. This patch came from
304     Daniel Bergström.
305 ph10 347
306 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
307 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
308     any errors with the current Unicode tables. Thanks to Peter Kankowski for
309     spotting this.
310 ph10 324
311 ph10 332
312 ph10 319 Version 7.6 28-Jan-08
313 ph10 300 ---------------------
314    
315 ph10 302 1. A character class containing a very large number of characters with
316     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
317     overflow.
318 ph10 309
319     2. Patch to cut out the "long long" test in pcrecpp_unittest when
320     HAVE_LONG_LONG is not defined.
321    
322 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
323 ph10 304 bring them up to date and include new features. This patch includes:
324 ph10 309
325 ph10 304 - Fixed PH's badly added libz and libbz2 support.
326     - Fixed a problem with static linking.
327 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
328 ph10 304 - Fixed dftables problem and added an option.
329     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
330     HAVE_LONG_LONG.
331     - Added readline support for pcretest.
332 ph10 309 - Added an listing of the option settings after cmake has run.
333    
334 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
335     "pcre.dll" under mingw when using Configure/Make. I added stuff to
336     Makefile.am that cause it to include this special target, without
337     affecting anything else. Note that the same mingw target plus all
338     the other distribution libraries and programs are now supported
339     when configuring with CMake (see 6 below) instead of with
340     Configure/Make.
341 ph10 309
342 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
343     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
344 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
345     solves the problem, but it does no harm.
346 ph10 313
347 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
348 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
349 ph10 314 with CMake, and also correct the comment about stack recursion.
350 ph10 313
351 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
352 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
353     of a program that users should build themselves after PCRE is installed, so
354     building it automatically is not really right. What is more, it gave
355 ph10 312 trouble in some build environments.
356 ph10 300
357 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
358 ph10 308
359 ph10 319
360 ph10 298 Version 7.5 10-Jan-08
361 ph10 263 ---------------------
362    
363     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
364     values in parens when parsing an RE using the C++ wrapper."
365 ph10 286
366 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
367     Characters greater than 255 were excluded from the class instead of being
368     included.
369 ph10 286
370     3. The same bug as (2) above applied to negated POSIX classes such as
371 ph10 265 [:^space:].
372 ph10 286
373 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
374     defined or documented. It seems to have been a typo for PCRE_STATIC, so
375 ph10 286 I have changed it.
376    
377 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
378 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
379     first named subpattern whose name started with "a" (in other words, the
380 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
381     expected" is now given for (?&) (a zero-length name), and this patch also
382     makes it give the same error for \k'' (previously it complained that that
383     was a reference to a non-existent subpattern).
384 ph10 286
385 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
386 ph10 286 this is right because (?- can be followed by option settings as well as by
387 ph10 269 digits. I have, however, made the messages clearer.
388 ph10 286
389 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
390     than the number used in the conditional) now cause a compile-time error.
391     This is actually not compatible with Perl, which accepts such patterns, but
392     treats the conditional as always being FALSE (as PCRE used to), but it
393     seems to me that giving a diagnostic is better.
394 ph10 286
395 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
396 ph10 275 and messages.
397 ph10 286
398     9. Fix two occurrences of "backslash" in comments that should have been
399     "backspace".
400    
401     10. Remove two redundant lines of code that can never be obeyed (their function
402     was moved elsewhere).
403    
404     11. The program that makes PCRE's Unicode character property table had a bug
405     which caused it to generate incorrect table entries for sequences of
406 ph10 277 characters that have the same character type, but are in different scripts.
407 ph10 286 It amalgamated them into a single range, with the script of the first of
408 ph10 277 them. In other words, some characters were in the wrong script. There were
409     thirteen such cases, affecting characters in the following ranges:
410 ph10 286
411 ph10 277 U+002b0 - U+002c1
412     U+0060c - U+0060d
413 ph10 286 U+0061e - U+00612
414 ph10 277 U+0064b - U+0065e
415     U+0074d - U+0076d
416     U+01800 - U+01805
417     U+01d00 - U+01d77
418     U+01d9b - U+01dbf
419     U+0200b - U+0200f
420     U+030fc - U+030fe
421     U+03260 - U+0327f
422     U+0fb46 - U+0fbb1
423     U+10450 - U+1049d
424 ph10 286
425 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
426     compatible with GNU grep in that, if there was more than one match in a
427     line, it showed only the first of them. It now behaves in the same way as
428     GNU grep.
429 ph10 286
430     13. If the -o and -v options were combined for pcregrep, it printed a blank
431     line for every non-matching line. GNU grep prints nothing, and pcregrep now
432     does the same. The return code can be used to tell if there were any
433     non-matching lines.
434    
435 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
436    
437     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
438 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
439 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
440     and both kinds of lookbehind were skipped).
441    
442 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
443 ph10 284 inclusion of <windows.h> to before rather than after the definition of
444     INVALID_FILE_ATTRIBUTES (patch from David Byron).
445 ph10 263
446 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
447 ph10 286 character property caused pcre_compile() to compile bad code, which led at
448     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
449     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
450     caused the error; without that there was no problem.
451 ph10 263
452 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
453 ph10 286
454 ph10 289 19. Added --enable-pcretest-libreadline.
455 ph10 286
456 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
457 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
458 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
459     later patch that removed the other one (the right fix) and added unit tests
460     that check the return values (which was not done before).
461 ph10 292
462 ph10 291 21. Several CMake things:
463 ph10 287
464 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
465 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
466 ph10 288
467 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
468     linked with the newly-built libraries, not previously installed ones.
469 ph10 291
470 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
471 ph10 298
472     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
473     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
474     UTF-8 newline character). The key issue is that the pattern starts .*;
475     this means that the match must be either at the beginning, or after a
476     newline. The bug was in the code for advancing after a failed match and
477     checking that the new position followed a newline. It was not taking
478 ph10 294 account of UTF-8 characters correctly.
479 ph10 298
480     23. PCRE was behaving differently from Perl in the way it recognized POSIX
481     character classes. PCRE was not treating the sequence [:...:] as a
482     character class unless the ... were all letters. Perl, however, seems to
483     allow any characters between [: and :], though of course it rejects as
484     unknown any "names" that contain non-letters, because all the known class
485     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
486     for example, whereas PCRE did not - it did not recognize a POSIX character
487     class. This seemed a bit dangerous, so the code has been changed to be
488     closer to Perl. The behaviour is not identical to Perl, because PCRE will
489     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
490     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
491     Perl does, and where it didn't before.
492    
493 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
494     Windows environments %n is disabled by default.
495 ph10 292
496    
497 ph10 260 Version 7.4 21-Sep-07
498 ph10 230 ---------------------
499    
500     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
501 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
502     LF". That isn't really right - the whole point of the change was to try to
503     help when there was an actual mention of one of the two characters. So now
504     the change happens only if \r or \n (or a literal CR or LF) character is
505 ph10 230 encountered.
506 ph10 231
507     2. The 32-bit options word was also used for 6 internal flags, but the numbers
508     of both had grown to the point where there were only 3 bits left.
509     Fortunately, there was spare space in the data structure, and so I have
510     moved the internal flags into a new 16-bit field to free up more option
511 ph10 230 bits.
512 ph10 231
513     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
514     but did not set the internal JCHANGED flag - either of these is enough to
515     control the way the "get" function works - but the PCRE_INFO_JCHANGED
516     facility is supposed to tell if (?J) was ever used, so now (?J) at the
517 ph10 230 start sets both bits.
518    
519 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
520     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
521 ph10 230
522 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
523    
524     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
525 ph10 233 compatibility, even though it is no longer used.
526 ph10 243
527     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
528 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
529 ph10 259 windows.h file is present (where different names are used). [This was
530 ph10 257 reversed later after testing - see 16 below.]
531 ph10 243
532     8. Changed all #include <config.h> to #include "config.h". There were also
533 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
534 ph10 243
535 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
536 ph10 243 sequence off the lines that it output.
537    
538     10. It was pointed out to me that arrays of string pointers cause lots of
539     relocations when a shared library is dynamically loaded. A technique of
540     using a single long string with a table of offsets can drastically reduce
541     these. I have refactored PCRE in four places to do this. The result is
542 ph10 240 dramatic:
543 ph10 243
544 ph10 240 Originally: 290
545     After changing UCP table: 187
546 ph10 243 After changing error message table: 43
547 ph10 240 After changing table of "verbs" 36
548     After changing table of Posix names 22
549 ph10 243
550 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
551 ph10 247
552 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
553 ph10 247 unicode-properties was also set.
554    
555 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
556 ph10 231
557 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
558     checked only for CRLF.
559 ph10 233
560 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
561    
562 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
563 ph10 253
564 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
565 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
566     entirely. This removes changes made in 7 above.
567 ph10 256
568 ph10 261 17. The CMake files have been updated, and there is now more information about
569     building with CMake in the NON-UNIX-USE document.
570 ph10 257
571 ph10 261
572 ph10 228 Version 7.3 28-Aug-07
573 ph10 157 ---------------------
574    
575 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
576     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
577     brackets there is not right, since it causes compilers to look for an
578     installed pcre.h, not the version that is in the source that is being
579     compiled (which of course may be different). I have changed it back to:
580 ph10 197
581 ph10 189 #include "pcre.h"
582 ph10 197
583     I have a vague recollection that the change was concerned with compiling in
584     different directories, but in the new build system, that is taken care of
585     by the VPATH setting the Makefile.
586    
587 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
588     when the subject happened to end in the byte 0x85 (e.g. if the last
589     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
590     characters but of course it shouldn't be taken as a newline when it is part
591     of another character. The bug was that, for an unlimited repeat of . in
592     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
593     characters when looking for a newline.
594 ph10 197
595     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
596    
597     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
598     in debug output.
599    
600 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
601     long printing in the pcrecpp unittest when running under MinGW.
602 ph10 189
603 ph10 197 6. ESC_K was left out of the EBCDIC table.
604 ph10 189
605 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
606     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
607     limit also applies to "virtual nesting" when a pattern is recursive, and in
608     this case 1000 isn't so big. I have been able to remove this limit at the
609     expense of backing off one optimization in certain circumstances. Normally,
610     when pcre_exec() would call its internal match() function recursively and
611     immediately return the result unconditionally, it uses a "tail recursion"
612     feature to save stack. However, when a subpattern that can match an empty
613     string has an unlimited repetition quantifier, it no longer makes this
614     optimization. That gives it a stack frame in which to save the data for
615     checking that an empty string has been matched. Previously this was taken
616     from the 1000-entry workspace that had been reserved. So now there is no
617     explicit limit, but more stack is used.
618 ph10 189
619 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
620     syntax that is required for Windows, and which was going wrong for the
621     pcreposix and pcrecpp parts of the library. These were overlooked when this
622     problem was solved for the main library.
623 ph10 197
624 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
625     the size of patterns that contain repeated groups with explicit upper
626     limits. As the maximum quantifier is 65535, the maximum group length was
627     set at 30,000 so that the product of these two numbers did not overflow a
628     32-bit integer. However, it turns out that people want to use groups that
629     are longer than 30,000 bytes (though not repeat them that many times).
630     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
631     made it possible to implement the integer overflow checks in a much more
632     dynamic way, which I have now done. The artificial limitation on group
633     length has been removed - we now have only the limit on the total length of
634     the compiled pattern, which depends on the LINK_SIZE setting.
635 ph10 208
636     10. Fixed a bug in the documentation for get/copy named substring when
637     duplicate names are permitted. If none of the named substrings are set, the
638     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
639     empty string.
640    
641     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
642     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
643     because the ] is interpreted as the first data character and the
644     terminating ] is not found. PCRE has been made compatible with Perl in this
645     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
646     cause memory overwriting.
647    
648 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
649     string has been matched (to stop an infinite loop). It was not recognizing
650 ph10 208 a conditional subpattern that could match an empty string if that
651 ph10 206 subpattern was within another subpattern. For example, it looped when
652 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
653 ph10 206 condition was not nested. This bug has been fixed.
654 ph10 208
655 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
656     past the start of the subject in the presence of bytes with the top bit
657     set, for example "\x8aBCD".
658 ph10 211
659 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
660     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
661 ph10 200
662 ph10 211 14. Optimized (?!) to (*FAIL).
663 ph10 202
664 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
665     This restricts code points to be within the range 0 to 0x10FFFF, excluding
666     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
667     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
668     does: it's just the validity check that is more restrictive.
669 ph10 220
670     16. Inserted checks for integer overflows during escape sequence (backslash)
671     processing, and also fixed erroneous offset values for syntax errors during
672     backslash processing.
673    
674 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
675 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
676    
677 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
678     caused an overrun.
679 ph10 220
680     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
681     something other than just ASCII characters) inside a group that had an
682     unlimited repeat caused a loop at compile time (while checking to see
683     whether the group could match an empty string).
684    
685 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
686     [\P{Any}] did so. (Error in the code for printing property names.)
687 ph10 210
688 ph10 220 21. An orphan \E inside a character class could cause a crash.
689    
690     22. A repeated capturing bracket such as (A)? could cause a wild memory
691 ph10 218 reference during compilation.
692 ph10 220
693     23. There are several functions in pcre_compile() that scan along a compiled
694     expression for various reasons (e.g. to see if it's fixed length for look
695 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
696 ph10 220 present in the pattern. These operators have additional parameters compared
697     with \d, etc, and these were not being taken into account when moving along
698 ph10 218 the compiled data. Specifically:
699 ph10 220
700     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
701     length.
702    
703     (b) An item such as \pL+ within a repeated group could cause crashes or
704 ph10 218 loops.
705 ph10 220
706 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
707 ph10 220 "reference to non-existent subpattern" error.
708    
709 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
710    
711 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
712 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
713 ph10 211
714 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
715 ph10 218
716 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
717 ph10 223 character were causing crashes (broken optimization).
718 ph10 227
719 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
720 ph10 227 \p or \P) caused a compile-time loop.
721    
722 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
723     break. For example, the unstudied pattern [\r\n]A does not match the string
724     "\r\nA" because change 7.0/46 below moves the current point on by two
725     characters after failing to match at the start. However, the pattern \nA
726 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
727     the same is true. There doesn't seem any very clean way out of this, but
728     what I have chosen to do makes the common cases work: PCRE now takes note
729     of whether there can be an explicit match for \r or \n anywhere in the
730     pattern, and if so, 7.0/46 no longer applies. As part of this change,
731     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
732     pattern has explicit CR or LF references.
733 ph10 222
734 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
735 ph10 223
736 ph10 227
737 ph10 189 Version 7.2 19-Jun-07
738     ---------------------
739    
740 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
741     which is apparently normally available under Windows.
742 ph10 159
743     2. Re-jig the pcregrep tests with different newline settings in an attempt
744     to make them independent of the local environment's newline setting.
745 ph10 157
746 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
747 ph10 165
748 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
749     was not 2, because the output contained actual offsets. The recent new
750 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
751     usable with all link sizes.
752    
753 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
754     stack recursion. This gives a massive performance boost under BSD, but just
755 ph10 165 a small improvement under Linux. However, it saves one field in the frame
756 ph10 164 in all cases.
757 ph10 172
758 ph10 166 6. Added more features from the forthcoming Perl 5.10:
759 ph10 172
760 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
761     recursion call. It refers to the nth most recently opened parentheses.
762 ph10 172
763 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
764 ph10 172 to be opened parentheses.
765    
766     (c) Conditions that refer to capturing parentheses can be specified
767 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
768 ph10 172
769 ph10 168 (d) \K resets the start of the current match so that everything before
770 ph10 172 is not part of it.
771    
772 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
773 ph10 172
774 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
775 ph10 172 reference syntax.
776 ph10 182
777 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
778 ph10 182 alternative starts with the same number.
779 ph10 172
780 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
781    
782 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
783     PCRE_INFO_JCHANGED.
784    
785     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
786     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
787 ph10 170 for detecting groups that can match an empty string.
788 ph10 159
789 ph10 172 9. A pattern with a very large number of alternatives (more than several
790     hundred) was running out of internal workspace during the pre-compile
791     phase, where pcre_compile() figures out how much memory will be needed. A
792     bit of new cunning has reduced the workspace needed for groups with
793     alternatives. The 1000-alternative test pattern now uses 12 bytes of
794     workspace instead of running out of the 4096 that are available.
795 ph10 182
796 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
797 ph10 172
798 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
799     The report of the bug said:
800 ph10 182
801 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
802     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
803 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
804 ph10 185
805 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
806 ph10 185 it matched the wrong number of bytes.
807 ph10 172
808 ph10 179
809 ph10 155 Version 7.1 24-Apr-07
810 ph10 98 ---------------------
811    
812 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
813 ph10 122 that is more "standard", making use of automake and other Autotools. There
814 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
815     on this.
816 ph10 111
817     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
818     for recursive directory scanning broke on some systems because the files
819     are not scanned in any specific order and on different systems the order
820     was different. A call to "sort" has been inserted into RunGrepTest for the
821     approprate test as a short-term fix. In the longer term there may be an
822 ph10 100 alternative.
823 ph10 111
824 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
825 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
826     people do their own conversions for various reasons). The problems
827     concerned the use of low-level troff macros .br and .in. I have therefore
828     removed all such uses from the man pages (some were redundant, some could
829 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
830     HTML has been updated to handle .nf/.fi and to complain if it encounters
831     .br or .in.
832 ph10 111
833 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
834 ph10 123 arranged for config.h to be included in the distribution, with the name
835 ph10 111 config.h.generic, for the benefit of those who have to compile without
836     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
837    
838     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
839     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
840 ph10 127 makevp.bat for the current PCRE, using the additional files
841 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
842 ph10 111
843     6. A Windows user reported a minor discrepancy with test 2, which turned out
844     to be caused by a trailing space on an input line that had got lost in his
845 ph10 102 copy. The trailing space was an accident, so I've just removed it.
846 ph10 111
847 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
848 ph10 111 that is needed.
849    
850 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
851     as "const" (a) because they are and (b) because it helps the PHP
852     maintainers who have recently made a script to detect big data structures
853 ph10 111 in the php code that should be moved to the .rodata section. I remembered
854     to update Builducptable as well, so it won't revert if ucptable.h is ever
855 ph10 105 re-created.
856 ph10 111
857     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
858 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
859 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
860     support is not required. This saves 1.5-2K of code, which is important in
861 ph10 107 some applications.
862 ph10 111
863 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
864 ph10 111 so as not to refer to the tables, even though these functions will never be
865     called when UTF-8 support is disabled. Otherwise there are problems with a
866     shared library.
867    
868 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
869    
870     (a) It was defining its arguments as char * instead of void *.
871    
872 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
873     a long time ago when I wrote it, but is no longer the case.
874    
875 ph10 118 The emulated memove() is provided for those environments that have neither
876 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
877 ph10 118 is clearly not the case, as these two bugs were recently reported.
878 ph10 123
879 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
880 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
881     pages, and it removes trailing spaces from listed files. It also creates
882     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
883     case, it wraps all the #defines with #ifndefs. This script should be run
884 ph10 111 before "make dist".
885 ph10 123
886 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
887     with Unicode property support.
888 ph10 123
889     (a) For a maximizing quantifier, if the two different cases of the
890     character were of different lengths in their UTF-8 codings (there are
891     some cases like this - I found 11), and the matching function had to
892 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
893     were both the same length.
894 ph10 123
895     (b) When PCRE was configured to use the heap rather than the stack for
896     recursion during matching, it was not correctly preserving the data for
897     the other case of a UTF-8 character when checking ahead for a match
898     while processing a minimizing repeat. If the check also involved
899 ph10 115 matching a wide character, but failed, corruption could cause an
900     erroneous result when trying to check for a repeat of the original
901     character.
902 ph10 123
903 ph10 116 13. Some tidying changes to the testing mechanism:
904 ph10 98
905 ph10 116 (a) The RunTest script now detects the internal link size and whether there
906     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
907 ph10 123 values substituted by "configure". (The RunGrepTest script already did
908     this for UTF-8.) The configure.ac script no longer substitutes the
909     relevant variables.
910    
911 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
912     with length and offset values. This means that the output is different
913     for different internal link sizes. Test 2 is skipped for link sizes
914     other than 2 because of this, bypassing the problem. Unfortunately,
915     there was also a test in test 3 (the locale tests) that used /B and
916 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
917     I have added a new /Z option to pcretest that replaces the length and
918     offset values with spaces. This is now used to make test 3 independent
919 ph10 122 of link size. (Test 2 will be tidied up later.)
920 ph10 123
921     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
922 ph10 122 segmentation fault instead of returning the appropriate error message.
923 ph10 134
924 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
925 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
926     This doesn't seem right; it now treats the CRLF combination as the line
927     ending, and so does not match in that case. It's only a pattern such as ^$
928     that would hit this one: something like ^ABC$ would have failed after \r
929     and then tried again after \r\n.
930    
931 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
932 ph10 134 in an attempt to make files that differ only in their line terminators
933     compare equal. This works on Linux.
934 ph10 142
935 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
936     as it exited. This is now fixed, thanks to valgrind.
937 ph10 142
938 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
939 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
940     was because its rules for how to advance for /g after matching an empty
941 ph10 143 string at the end of a line did not allow for this case. They now check for
942     it specially.
943 ph10 150
944     20. pcretest is supposed to handle patterns and data of any length, by
945     extending its buffers when necessary. It was getting this wrong when the
946 ph10 147 buffer for a data line had to be extended.
947 ph10 150
948 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
949 ph10 150 CRLF as a newline sequence.
950 ph10 152
951 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
952 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
953     I have nevertheless tidied it up.
954 ph10 111
955 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
956 ph10 123
957 ph10 153 24. Added a man page for pcre-config.
958 ph10 152
959 ph10 153
960 nigel 93 Version 7.0 19-Dec-06
961     ---------------------
962    
963     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
964     moving to gcc 4.1.1.
965    
966     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
967     sys/time.h, which is documented as needed for this function. It doesn't
968     seem to matter on Linux, but it showed up on some releases of OS X.
969    
970     3. It seems that there are systems where bytes whose values are greater than
971     127 match isprint() in the "C" locale. The "C" locale should be the
972     default when a C program starts up. In most systems, only ASCII printing
973     characters match isprint(). This difference caused the output from pcretest
974     to vary, making some of the tests fail. I have changed pcretest so that:
975    
976     (a) When it is outputting text in the compiled version of a pattern, bytes
977     other than 32-126 are always shown as hex escapes.
978    
979     (b) When it is outputting text that is a matched part of a subject string,
980     it does the same, unless a different locale has been set for the match
981     (using the /L modifier). In this case, it uses isprint() to decide.
982    
983     4. Fixed a major bug that caused incorrect computation of the amount of memory
984     required for a compiled pattern when options that changed within the
985     pattern affected the logic of the preliminary scan that determines the
986     length. The relevant options are -x, and -i in UTF-8 mode. The result was
987     that the computed length was too small. The symptoms of this bug were
988     either the PCRE error "internal error: code overflow" from pcre_compile(),
989     or a glibc crash with a message such as "pcretest: free(): invalid next
990     size (fast)". Examples of patterns that provoked this bug (shown in
991     pcretest format) are:
992    
993     /(?-x: )/x
994     /(?x)(?-x: \s*#\s*)/
995     /((?i)[\x{c0}])/8
996     /(?i:[\x{c0}])/8
997    
998     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
999     is now done differently.
1000    
1001     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
1002     wrapper classes; (b) implement a new function in the C++ scanner that is
1003     more efficient than the old way of doing things because it avoids levels of
1004     recursion in the regex matching; (c) add a paragraph to the documentation
1005     for the FullMatch() function.
1006    
1007     6. The escape sequence \n was being treated as whatever was defined as
1008     "newline". Not only was this contrary to the documentation, which states
1009     that \n is character 10 (hex 0A), but it also went horribly wrong when
1010     "newline" was defined as CRLF. This has been fixed.
1011    
1012     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
1013     was being set to -1 for the "end of line" case (supposedly a value that no
1014     character can have). Though this value is never used (the check for end of
1015     line is "zero bytes in current character"), it caused compiler complaints.
1016     I've changed it to 0xffffffff.
1017    
1018     8. In pcre_version.c, the version string was being built by a sequence of
1019     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
1020     string (as it is for production releases) called a macro with an empty
1021     argument. The C standard says the result of this is undefined. The gcc
1022     compiler treats it as an empty string (which was what was wanted) but it is
1023     reported that Visual C gives an error. The source has been hacked around to
1024     avoid this problem.
1025    
1026     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
1027     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
1028     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
1029     of them did).
1030    
1031     10. Originally, pcretest opened its input and output without "b"; then I was
1032     told that "b" was needed in some environments, so it was added for release
1033     5.0 to both the input and output. (It makes no difference on Unix-like
1034     systems.) Later I was told that it is wrong for the input on Windows. I've
1035     now abstracted the modes into two macros, to make it easier to fiddle with
1036     them, and removed "b" from the input mode under Windows.
1037    
1038     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
1039    
1040     12. Added -help and --help to pcretest as an official way of being reminded
1041     of the options.
1042    
1043     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
1044     and pcrecpp.cc because they annoy compilers at high warning levels.
1045    
1046     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
1047    
1048     15. Fixed an occurrence of == in configure.ac that should have been = (shell
1049     scripts are not C programs :-) and which was not noticed because it works
1050     on Linux.
1051    
1052     16. pcretest is supposed to handle any length of pattern and data line (as one
1053     line or as a continued sequence of lines) by extending its input buffer if
1054     necessary. This feature was broken for very long pattern lines, leading to
1055     a string of junk being passed to pcre_compile() if the pattern was longer
1056     than about 50K.
1057    
1058     17. I have done a major re-factoring of the way pcre_compile() computes the
1059     amount of memory needed for a compiled pattern. Previously, there was code
1060     that made a preliminary scan of the pattern in order to do this. That was
1061     OK when PCRE was new, but as the facilities have expanded, it has become
1062     harder and harder to keep it in step with the real compile phase, and there
1063     have been a number of bugs (see for example, 4 above). I have now found a
1064     cunning way of running the real compile function in a "fake" mode that
1065     enables it to compute how much memory it would need, while actually only
1066     ever using a few hundred bytes of working memory and without too many
1067     tests of the mode. This should make future maintenance and development
1068     easier. A side effect of this work is that the limit of 200 on the nesting
1069     depth of parentheses has been removed (though this was never a serious
1070     limitation, I suspect). However, there is a downside: pcre_compile() now
1071     runs more slowly than before (30% or more, depending on the pattern). I
1072     hope this isn't a big issue. There is no effect on runtime performance.
1073    
1074     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
1075     newline (only possible for the last line of a file) and it was a
1076     pattern that set a locale (followed by /Lsomething), pcretest crashed.
1077    
1078     19. Added additional timing features to pcretest. (1) The -tm option now times
1079     matching only, not compiling. (2) Both -t and -tm can be followed, as a
1080     separate command line item, by a number that specifies the number of
1081     repeats to use when timing. The default is 50000; this gives better
1082     precision, but takes uncomfortably long for very large patterns.
1083    
1084     20. Extended pcre_study() to be more clever in cases where a branch of a
1085     subpattern has no definite first character. For example, (a*|b*)[cd] would
1086     previously give no result from pcre_study(). Now it recognizes that the
1087     first character must be a, b, c, or d.
1088    
1089     21. There was an incorrect error "recursive call could loop indefinitely" if
1090     a subpattern (or the entire pattern) that was being tested for matching an
1091     empty string contained only one non-empty item after a nested subpattern.
1092     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
1093     incorrectly, because the \d was being skipped in the check.
1094    
1095     22. The pcretest program now has a new pattern option /B and a command line
1096     option -b, which is equivalent to adding /B to every pattern. This causes
1097     it to show the compiled bytecode, without the additional information that
1098     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
1099     is the same as /B/I).
1100    
1101     23. A new optimization is now able automatically to treat some sequences such
1102     as a*b as a*+b. More specifically, if something simple (such as a character
1103     or a simple class like \d) has an unlimited quantifier, and is followed by
1104     something that cannot possibly match the quantified thing, the quantifier
1105     is automatically "possessified".
1106    
1107     24. A recursive reference to a subpattern whose number was greater than 39
1108     went wrong under certain circumstances in UTF-8 mode. This bug could also
1109     have affected the operation of pcre_study().
1110    
1111     25. Realized that a little bit of performance could be had by replacing
1112     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
1113    
1114     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
1115    
1116     27. Possessive quantifiers such as a++ were previously implemented by turning
1117     them into atomic groups such as ($>a+). Now they have their own opcodes,
1118     which improves performance. This includes the automatically created ones
1119     from 23 above.
1120    
1121     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
1122     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
1123     the first matched character to be a colon. This applied both to named and
1124     numbered groups.
1125    
1126     29. The ucpinternal.h header file was missing its idempotency #ifdef.
1127    
1128     30. I was sent a "project" file called libpcre.a.dev which I understand makes
1129     building PCRE on Windows easier, so I have included it in the distribution.
1130    
1131     31. There is now a check in pcretest against a ridiculously large number being
1132     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
1133     loop, the loop is abandoned.
1134    
1135     32. Forward references to subpatterns in conditions such as (?(2)...) where
1136     subpattern 2 is defined later cause pcre_compile() to search forwards in
1137     the pattern for the relevant set of parentheses. This search went wrong
1138     when there were unescaped parentheses in a character class, parentheses
1139     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
1140    
1141     33. "Subroutine" calls and backreferences were previously restricted to
1142     referencing subpatterns earlier in the regex. This restriction has now
1143     been removed.
1144    
1145     34. Added a number of extra features that are going to be in Perl 5.10. On the
1146     whole, these are just syntactic alternatives for features that PCRE had
1147     previously implemented using the Python syntax or my own invention. The
1148     other formats are all retained for compatibility.
1149    
1150     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
1151     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
1152     also .NET compatible.
1153    
1154     (b) A recursion or subroutine call to a named group can now be defined as
1155     (?&name) as well as (?P>name).
1156    
1157     (c) A backreference to a named group can now be defined as \k<name> or
1158     \k'name' as well as (?P=name). The new forms, as well as being in Perl
1159     5.10, are also .NET compatible.
1160    
1161     (d) A conditional reference to a named group can now use the syntax
1162     (?(<name>) or (?('name') as well as (?(name).
1163    
1164     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
1165     groups (named and numbered) that are never evaluated inline, but can be
1166     called as "subroutines" from elsewhere. In effect, the DEFINE condition
1167     is always false. There may be only one alternative in such a group.
1168    
1169     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
1170     as the simple (?(R). The condition is true only if the most recent
1171     recursion is that of the given number or name. It does not search out
1172     through the entire recursion stack.
1173    
1174     (g) The escape \gN or \g{N} has been added, where N is a positive or
1175     negative number, specifying an absolute or relative reference.
1176    
1177     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1178     some "unreachable code" warnings.
1179    
1180     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1181     things, this adds five new scripts.
1182    
1183     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1184     There were also incompatibilities regarding the handling of \Q..\E inside
1185     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1186     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1187    
1188     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1189     matches an empty string, and forcibly breaks the loop. There were bugs in
1190     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1191     against aaaa the result was just "a" rather than "aaaa", for example. Two
1192     separate and independent bugs (that affected different cases) have been
1193     fixed.
1194    
1195     39. Refactored the code to abolish the use of different opcodes for small
1196     capturing bracket numbers. This is a tidy that I avoided doing when I
1197     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1198     The new approach is not only tidier, it makes it possible to reduce the
1199     memory needed to fix the previous bug (38).
1200    
1201     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1202     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1203     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1204     mode.
1205    
1206     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1207     report.
1208    
1209     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1210     copy construction and assignment in the C++ wrapper.
1211    
1212     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1213     couple of bugs that could have given wrong results in the "--newline=crlf"
1214     case.
1215    
1216     44. Added a number of casts and did some reorganization of signed/unsigned int
1217     variables following suggestions from Dair Grant. Also renamed the variable
1218     "this" as "item" because it is a C++ keyword.
1219    
1220     45. Arranged for dftables to add
1221    
1222     #include "pcre_internal.h"
1223    
1224     to pcre_chartables.c because without it, gcc 4.x may remove the array
1225     definition from the final binary if PCRE is built into a static library and
1226     dead code stripping is activated.
1227    
1228     46. For an unanchored pattern, if a match attempt fails at the start of a
1229     newline sequence, and the newline setting is CRLF or ANY, and the next two
1230     characters are CRLF, advance by two characters instead of one.
1231    
1232    
1233 nigel 91 Version 6.7 04-Jul-06
1234     ---------------------
1235    
1236     1. In order to handle tests when input lines are enormously long, pcretest has
1237     been re-factored so that it automatically extends its buffers when
1238     necessary. The code is crude, but this _is_ just a test program. The
1239     default size has been increased from 32K to 50K.
1240    
1241     2. The code in pcre_study() was using the value of the re argument before
1242     testing it for NULL. (Of course, in any sensible call of the function, it
1243     won't be NULL.)
1244    
1245     3. The memmove() emulation function in pcre_internal.h, which is used on
1246     systems that lack both memmove() and bcopy() - that is, hardly ever -
1247     was missing a "static" storage class specifier.
1248    
1249     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1250     containing an extended class (one that cannot be represented by a bitmap
1251     because it contains high-valued characters or Unicode property items, e.g.
1252     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1253     pattern, but PCRE should not loop if you do not (it no longer does).
1254     [Detail: two cases were found: (a) a repeated subpattern containing an
1255     extended class; (b) a recursive reference to a subpattern that followed a
1256     previous extended class. It wasn't skipping over the extended class
1257     correctly when UTF-8 mode was not set.]
1258    
1259     5. A negated single-character class was not being recognized as fixed-length
1260     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1261     compile error "lookbehind assertion is not fixed length".
1262    
1263     6. The RunPerlTest auxiliary script was showing an unexpected difference
1264     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1265     write a Perl script that can interpret lines of an input file either as
1266     byte characters or as UTF-8, which is what "perltest" was being required to
1267     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1268     can't do is switch easily at run time between having the "use utf8;" pragma
1269     or not. In the end, I fudged it by using the RunPerlTest script to insert
1270     "use utf8;" explicitly for the UTF-8 tests.
1271    
1272     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1273     the end of the subject string, contrary to the documentation and to what
1274     Perl does. This was true of both matching functions. Now it matches only at
1275     the start of the subject and immediately after *internal* newlines.
1276    
1277     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1278     a pointer to an int instead of a pointer to an unsigned long int. This
1279     caused problems on 64-bit systems.
1280    
1281     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1282     instance of the 'standard' template library not being so standard".
1283    
1284     10. There was no check on the number of named subpatterns nor the maximum
1285     length of a subpattern name. The product of these values is used to compute
1286     the size of the memory block for a compiled pattern. By supplying a very
1287     long subpattern name and a large number of named subpatterns, the size
1288     computation could be caused to overflow. This is now prevented by limiting
1289     the length of names to 32 characters, and the number of named subpatterns
1290     to 10,000.
1291    
1292     11. Subpatterns that are repeated with specific counts have to be replicated in
1293     the compiled pattern. The size of memory for this was computed from the
1294     length of the subpattern and the repeat count. The latter is limited to
1295     65535, but there was no limit on the former, meaning that integer overflow
1296     could in principle occur. The compiled length of a repeated subpattern is
1297     now limited to 30,000 bytes in order to prevent this.
1298    
1299     12. Added the optional facility to have named substrings with the same name.
1300    
1301     13. Added the ability to use a named substring as a condition, using the
1302     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1303     are numbers (not recommended). Forward references are permitted.
1304    
1305     14. Added forward references in named backreferences (if you see what I mean).
1306    
1307     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1308     pattern could run off the end of the subject. For example, the pattern
1309     "(?s)(.{1,5})"8 did this with the subject "ab".
1310    
1311     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1312     PCRE_CASELESS was set when matching characters that were quantified with ?
1313     or *.
1314    
1315     17. A character class other than a single negated character that had a minimum
1316     but no maximum quantifier - for example [ab]{6,} - was not handled
1317     correctly by pce_dfa_exec(). It would match only one character.
1318    
1319     18. A valid (though odd) pattern that looked like a POSIX character
1320     class but used an invalid character after [ (for example [[,abc,]]) caused
1321     pcre_compile() to give the error "Failed: internal error: code overflow" or
1322     in some cases to crash with a glibc free() error. This could even happen if
1323     the pattern terminated after [[ but there just happened to be a sequence of
1324     letters, a binary zero, and a closing ] in the memory that followed.
1325    
1326     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1327     over the years. Originally (before any Unicode support), just the bottom 8
1328     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1329     output from "man perlunicode" includes this:
1330    
1331     The regular expression compiler produces polymorphic opcodes. That
1332     is, the pattern adapts to the data and automatically switches to
1333     the Unicode character scheme when presented with Unicode data--or
1334     instead uses a traditional byte scheme when presented with byte
1335     data.
1336    
1337     Sadly, a wide octal escape does not cause a switch, and in a string with
1338     no other multibyte characters, these octal escapes are treated as before.
1339     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1340     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1341     Unicode string.
1342    
1343     I have not perpetrated such confusion in PCRE. Up till now, it took just
1344     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1345     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1346     translate to the appropriate multibyte character.
1347    
1348     29. Applied some refactoring to reduce the number of warnings from Microsoft
1349     and Borland compilers. This has included removing the fudge introduced
1350     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1351     a warning about an unused variable.
1352    
1353     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1354     characters since release 4.0, because Perl (from release 5.004) does not.
1355     [Or at least, is documented not to: some releases seem to be in conflict
1356     with the documentation.] However, when a pattern was studied with
1357     pcre_study() and all its branches started with \s, PCRE still included VT
1358     as a possible starting character. Of course, this did no harm; it just
1359     caused an unnecessary match attempt.
1360    
1361     22. Removed a now-redundant internal flag bit that recorded the fact that case
1362     dependency changed within the pattern. This was once needed for "required
1363     byte" processing, but is no longer used. This recovers a now-scarce options
1364     bit. Also moved the least significant internal flag bit to the most-
1365     significant bit of the word, which was not previously used (hangover from
1366     the days when it was an int rather than a uint) to free up another bit for
1367     the future.
1368    
1369     23. Added support for CRLF line endings as well as CR and LF. As well as the
1370     default being selectable at build time, it can now be changed at runtime
1371     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1372     specify that it is scanning data with non-default line endings.
1373    
1374     24. Changed the definition of CXXLINK to make it agree with the definition of
1375     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1376    
1377     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1378     recursions. This makes a big different to stack usage for some patterns.
1379    
1380     26. If a subpattern containing a named recursion or subroutine reference such
1381     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1382     the space required for the compiled pattern went wrong and gave too small a
1383     value. Depending on the environment, this could lead to "Failed: internal
1384     error: code overflow at offset 49" or "glibc detected double free or
1385     corruption" errors.
1386    
1387     27. Applied patches from Google (a) to support the new newline modes and (b) to
1388     advance over multibyte UTF-8 characters in GlobalReplace.
1389    
1390     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1391     difference for some implementation of PCRE in some Windows version.
1392    
1393     29. Added some extra testing facilities to pcretest:
1394    
1395     \q<number> in a data line sets the "match limit" value
1396     \Q<number> in a data line sets the "match recursion limt" value
1397     -S <number> sets the stack size, where <number> is in megabytes
1398    
1399     The -S option isn't available for Windows.
1400    
1401    
1402 nigel 89 Version 6.6 06-Feb-06
1403     ---------------------
1404    
1405     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1406     in pcreposix.h. I have copied the definition from pcre.h.
1407    
1408     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1409     because pcre.h is no longer a built file.
1410    
1411     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1412     not normally included in the compiled code.
1413    
1414    
1415 nigel 87 Version 6.5 01-Feb-06
1416     ---------------------
1417    
1418     1. When using the partial match feature with pcre_dfa_exec(), it was not
1419     anchoring the second and subsequent partial matches at the new starting
1420     point. This could lead to incorrect results. For example, with the pattern
1421     /1234/, partially matching against "123" and then "a4" gave a match.
1422    
1423     2. Changes to pcregrep:
1424    
1425     (a) All non-match returns from pcre_exec() were being treated as failures
1426     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1427     error message is output. Some extra information is given for the
1428     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1429     probably the only errors that are likely to be caused by users (by
1430     specifying a regex that has nested indefinite repeats, for instance).
1431     If there are more than 20 of these errors, pcregrep is abandoned.
1432    
1433     (b) A binary zero was treated as data while matching, but terminated the
1434     output line if it was written out. This has been fixed: binary zeroes
1435     are now no different to any other data bytes.
1436    
1437     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1438     used to set a locale for matching. The --locale=xxxx long option has
1439     been added (no short equivalent) to specify a locale explicitly on the
1440     pcregrep command, overriding the environment variables.
1441    
1442     (d) When -B was used with -n, some line numbers in the output were one less
1443     than they should have been.
1444    
1445     (e) Added the -o (--only-matching) option.
1446    
1447     (f) If -A or -C was used with -c (count only), some lines of context were
1448     accidentally printed for the final match.
1449    
1450     (g) Added the -H (--with-filename) option.
1451    
1452     (h) The combination of options -rh failed to suppress file names for files
1453     that were found from directory arguments.
1454    
1455     (i) Added the -D (--devices) and -d (--directories) options.
1456    
1457     (j) Added the -F (--fixed-strings) option.
1458    
1459     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1460    
1461     (l) Added the --colo(u)r option.
1462    
1463     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1464     is not present by default.
1465    
1466     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1467     items such as (?R) or (?1), when the recursion could match a number of
1468     alternatives. If it matched one of the alternatives, but subsequently,
1469     outside the recursion, there was a failure, the code tried to back up into
1470     the recursion. However, because of the way PCRE is implemented, this is not
1471     possible, and the result was an incorrect result from the match.
1472    
1473     In order to prevent this happening, the specification of recursion has
1474     been changed so that all such subpatterns are automatically treated as
1475     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1476    
1477     4. I had overlooked the fact that, in some locales, there are characters for
1478     which isalpha() is true but neither isupper() nor islower() are true. In
1479     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1480     and ordfeminine) are like this. This affected the treatment of \w and \W
1481     when they appeared in character classes, but not when they appeared outside
1482     a character class. The bit map for "word" characters is now created
1483     separately from the results of isalnum() instead of just taking it from the
1484     upper, lower, and digit maps. (Plus the underscore character, of course.)
1485    
1486     5. The above bug also affected the handling of POSIX character classes such as
1487     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1488     permanent tables. Instead, the bit maps for such a class were previously
1489     created as the appropriate unions of the upper, lower, and digit bitmaps.
1490     Now they are created by subtraction from the [[:word:]] class, which has
1491     its own bitmap.
1492    
1493     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1494     It is created by subtracting the vertical space characters (\x09, \x0a,
1495     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1496     subtraction was done in the overall bitmap for a character class, meaning
1497     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1498     be recognized. This bug has been fixed.
1499    
1500     7. Patches from the folks at Google:
1501    
1502     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1503     real life, but is still worth protecting against".
1504    
1505     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1506     regular expressions".
1507    
1508     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1509     have it.
1510    
1511     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1512     "configure" and the latter not, in order to fix a problem somebody had
1513     with compiling the Arg class on HP-UX.
1514    
1515     (e) Improve the error-handling of the C++ wrapper a little bit.
1516    
1517     (f) New tests for checking recursion limiting.
1518    
1519     8. The pcre_memmove() function, which is used only if the environment does not
1520     have a standard memmove() function (and is therefore rarely compiled),
1521     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1522     returning a result (though PCRE never actually uses the result).
1523    
1524     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1525     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1526     returned instead of calling malloc() with an overflowing number that would
1527     most likely cause subsequent chaos.
1528    
1529     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1530    
1531     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1532     with this option is matched, the nmatch and pmatch options of regexec() are
1533     ignored.
1534    
1535     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1536     provided in case anyone wants to the the POSIX interface with UTF-8
1537     strings.
1538    
1539     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1540     C++ linking (needed for some HP-UX environments).
1541    
1542     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1543     (unused parameter) and in the pcre_printint() function (omitted "default"
1544     switch label when the default is to do nothing).
1545    
1546     15. Added some code to make it possible, when PCRE is compiled as a C++
1547     library, to replace subject pointers for pcre_exec() with a smart pointer
1548     class, thus making it possible to process discontinuous strings.
1549    
1550     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1551     much the same function. They were added by different people who were trying
1552     to make PCRE easy to compile on non-Unix systems. It has been suggested
1553     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1554     for compiling on Windows systems. I have therefore replaced it with
1555     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1556     defaults to "extern" for C or "extern C" for C++, which works fine on
1557     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1558     SCOPE with something explicit in config.h. In addition:
1559    
1560     (a) pcreposix.h still had just "extern" instead of either of these macros;
1561     I have replaced it with PCRE_DATA_SCOPE.
1562    
1563     (b) Functions such as _pcre_xclass(), which are internal to the library,
1564     but external in the C sense, all had PCRE_EXPORT in their definitions.
1565     This is apparently wrong for the Windows case, so I have removed it.
1566     (It makes no difference on Unix-like systems.)
1567    
1568     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1569     of recursive calls to match(). This is different to MATCH_LIMIT because
1570     that limits the total number of calls to match(), not all of which increase
1571     the depth of recursion. Limiting the recursion depth limits the amount of
1572     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1573     when PCRE is compiled, and changed at run time. A patch from Google adds
1574     this functionality to the C++ interface.
1575    
1576     18. Changes to the handling of Unicode character properties:
1577    
1578     (a) Updated the table to Unicode 4.1.0.
1579    
1580     (b) Recognize characters that are not in the table as "Cn" (undefined).
1581    
1582     (c) I revised the way the table is implemented to a much improved format
1583     which includes recognition of ranges. It now supports the ranges that
1584     are defined in UnicodeData.txt, and it also amalgamates other
1585     characters into ranges. This has reduced the number of entries in the
1586     table from around 16,000 to around 3,000, thus reducing its size
1587     considerably. I realized I did not need to use a tree structure after
1588     all - a binary chop search is just as efficient. Having reduced the
1589     number of entries, I extended their size from 6 bytes to 8 bytes to
1590     allow for more data.
1591    
1592     (d) Added support for Unicode script names via properties such as \p{Han}.
1593    
1594     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1595     matching that character.
1596    
1597     20. When matching a repeated Unicode property with a minimum greater than zero,
1598     (for example \pL{2,}), PCRE could look past the end of the subject if it
1599     reached it while seeking the minimum number of characters. This could
1600     happen only if some of the characters were more than one byte long, because
1601     there is a check for at least the minimum number of bytes.
1602    
1603     21. Refactored the implementation of \p and \P so as to be more general, to
1604     allow for more different types of property in future. This has changed the
1605     compiled form incompatibly. Anybody with saved compiled patterns that use
1606     \p or \P will have to recompile them.
1607    
1608     22. Added "Any" and "L&" to the supported property types.
1609    
1610     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1611     but give a compile time error if the value is greater than 0xff.
1612    
1613     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1614     accidentally not being installed or uninstalled.
1615    
1616     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1617     made were to insert the current release number. This seemed silly, because
1618     it made things harder for people building PCRE on systems that don't run
1619     "configure". I have turned pcre.h into a distributed file, no longer built
1620     by "configure", with the version identification directly included. There is
1621     no longer a pcre.h.in file.
1622    
1623     However, this change necessitated a change to the pcre-config script as
1624     well. It is built from pcre-config.in, and one of the substitutions was the
1625     release number. I have updated configure.ac so that ./configure now finds
1626     the release number by grepping pcre.h.
1627    
1628     26. Added the ability to run the tests under valgrind.
1629    
1630    
1631 nigel 85 Version 6.4 05-Sep-05
1632     ---------------------
1633    
1634     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1635     "--" to be printed when multiple files were scanned, even when none of the
1636     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1637     consider it to be a bug, and have restored the previous behaviour.
1638    
1639     2. A couple of code tidies to get rid of compiler warnings.
1640    
1641     3. The pcretest program used to cheat by referring to symbols in the library
1642     whose names begin with _pcre_. These are internal symbols that are not
1643     really supposed to be visible externally, and in some environments it is
1644     possible to suppress them. The cheating is now confined to including
1645     certain files from the library's source, which is a bit cleaner.
1646    
1647     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1648     file's purpose clearer.
1649    
1650     5. Reorganized pcre_ucp_findchar().
1651    
1652    
1653 nigel 83 Version 6.3 15-Aug-05
1654     ---------------------
1655    
1656     1. The file libpcre.pc.in did not have general read permission in the tarball.
1657    
1658     2. There were some problems when building without C++ support:
1659    
1660     (a) If C++ support was not built, "make install" and "make test" still
1661     tried to test it.
1662    
1663     (b) There were problems when the value of CXX was explicitly set. Some
1664     changes have been made to try to fix these, and ...
1665    
1666     (c) --disable-cpp can now be used to explicitly disable C++ support.
1667    
1668     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1669     backslash in a target when C++ was disabled. This confuses some
1670     versions of "make", apparently. Using an intermediate variable solves
1671     this. (Same for CPP_LOBJ.)
1672    
1673     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1674     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1675     necessary on certain architectures.
1676    
1677     4. Added a setting of -export-symbols-regex to the link command to remove
1678     those symbols that are exported in the C sense, but actually are local
1679     within the library, and not documented. Their names all begin with
1680     "_pcre_". This is not a perfect job, because (a) we have to except some
1681     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1682     available (and never for static libraries). I have made a note to try to
1683     find a way round (a) in the future.
1684    
1685    
1686 nigel 81 Version 6.2 01-Aug-05
1687     ---------------------
1688    
1689     1. There was no test for integer overflow of quantifier values. A construction
1690     such as {1111111111111111} would give undefined results. What is worse, if
1691     a minimum quantifier for a parenthesized subpattern overflowed and became
1692     negative, the calculation of the memory size went wrong. This could have
1693     led to memory overwriting.
1694    
1695     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1696    
1697     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1698     operating environments where this matters.
1699    
1700     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1701     PCRE options from within the C++ wrapper.
1702    
1703     5. Named capturing subpatterns were not being correctly counted when a pattern
1704     was compiled. This caused two problems: (a) If there were more than 100
1705     such subpatterns, the calculation of the memory needed for the whole
1706     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1707     back references of the form \12, where the number was greater than 9, were
1708     not recognized as back references, even though there were sufficient
1709     previous subpatterns.
1710    
1711     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1712     versions of gcc, e.g. 2.95.4.
1713    
1714    
1715 nigel 79 Version 6.1 21-Jun-05
1716     ---------------------
1717    
1718     1. There was one reference to the variable "posix" in pcretest.c that was not
1719     surrounded by "#if !defined NOPOSIX".
1720    
1721     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1722     the cross-check on the old pcre_info() function, for the benefit of the
1723     cut-down version of PCRE that is currently imported into Exim.
1724    
1725     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1726     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1727     patterns that start (?i) but I don't think that matters. The use of (?i) is
1728     just an example; this all applies to the other options as well.
1729    
1730     4. Since libtool seems to echo the compile commands it is issuing, the output
1731     from "make" can be reduced a bit by putting "@" in front of each libtool
1732     compile command.
1733    
1734     5. Patch from the folks at Google for configure.in to be a bit more thorough
1735     in checking for a suitable C++ installation before trying to compile the
1736     C++ stuff. This should fix a reported problem when a compiler was present,
1737     but no suitable headers.
1738    
1739     6. The man pages all had just "PCRE" as their title. I have changed them to
1740     be the relevant file name. I have also arranged that these names are
1741     retained in the file doc/pcre.txt, which is a concatenation in text format
1742     of all the man pages except the little individual ones for each function.
1743    
1744     7. The NON-UNIX-USE file had not been updated for the different set of source
1745     files that come with release 6. I also added a few comments about the C++
1746     wrapper.
1747    
1748    
1749 nigel 77 Version 6.0 07-Jun-05
1750     ---------------------
1751    
1752     1. Some minor internal re-organization to help with my DFA experiments.
1753    
1754     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1755     didn't matter for the library itself when fully configured, but did matter
1756     when compiling without UCP support, or within Exim, where the ucp files are
1757     not imported.
1758    
1759     3. Refactoring of the library code to split up the various functions into
1760     different source modules. The addition of the new DFA matching code (see
1761     below) to a single monolithic source would have made it really too
1762     unwieldy, quite apart from causing all the code to be include in a
1763     statically linked application, when only some functions are used. This is
1764     relevant even without the DFA addition now that patterns can be compiled in
1765     one application and matched in another.
1766    
1767     The downside of splitting up is that there have to be some external
1768     functions and data tables that are used internally in different modules of
1769     the library but which are not part of the API. These have all had their
1770     names changed to start with "_pcre_" so that they are unlikely to clash
1771     with other external names.
1772    
1773     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1774     a different (DFA) algorithm. Although it is slower than the original
1775     function, it does have some advantages for certain types of matching
1776     problem.
1777    
1778     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1779     including restarting after a partial match.
1780    
1781     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1782     defined when compiling for Windows was sent to me. I have put it into the
1783     code, though I have no means of testing or verifying it.
1784    
1785     7. Added the pcre_refcount() auxiliary function.
1786    
1787     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1788     match before or at the first newline in the subject string. In pcretest,
1789     the /f option on a pattern can be used to set this.
1790    
1791     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1792     would behave wrongly. This has been present in PCRE since release 4.0.
1793    
1794     10. A number of changes to the pcregrep command:
1795    
1796     (a) Refactored how -x works; insert ^(...)$ instead of setting
1797     PCRE_ANCHORED and checking the length, in preparation for adding
1798     something similar for -w.
1799    
1800     (b) Added the -w (match as a word) option.
1801    
1802     (c) Refactored the way lines are read and buffered so as to have more
1803     than one at a time available.
1804    
1805     (d) Implemented a pcregrep test script.
1806    
1807     (e) Added the -M (multiline match) option. This allows patterns to match
1808     over several lines of the subject. The buffering ensures that at least
1809     8K, or the rest of the document (whichever is the shorter) is available
1810     for matching (and similarly the previous 8K for lookbehind assertions).
1811    
1812     (f) Changed the --help output so that it now says
1813    
1814     -w, --word-regex(p)
1815    
1816     instead of two lines, one with "regex" and the other with "regexp"
1817     because that confused at least one person since the short forms are the
1818     same. (This required a bit of code, as the output is generated
1819     automatically from a table. It wasn't just a text change.)
1820    
1821     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1822     option but starts with a hyphen. Could be a pattern or a path name
1823     starting with a hyphen, for instance.
1824    
1825     (h) "-" can be given as a file name to represent stdin.
1826    
1827     (i) When file names are being printed, "(standard input)" is used for
1828     the standard input, for compatibility with GNU grep. Previously
1829     "<stdin>" was used.
1830    
1831     (j) The option --label=xxx can be used to supply a name to be used for
1832     stdin when file names are being printed. There is no short form.
1833    
1834     (k) Re-factored the options decoding logic because we are going to add
1835     two more options that take data. Such options can now be given in four
1836     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1837    
1838     (l) Added the -A, -B, and -C options for requesting that lines of context
1839     around matches be printed.
1840    
1841     (m) Added the -L option to print the names of files that do not contain
1842     any matching lines, that is, the complement of -l.
1843    
1844     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1845     continue to scan other files.
1846    
1847     (o) The -s option was incorrectly implemented. For compatibility with other
1848     greps, it now suppresses the error message for a non-existent or non-
1849     accessible file (but not the return code). There is a new option called
1850     -q that suppresses the output of matching lines, which was what -s was
1851     previously doing.
1852    
1853     (p) Added --include and --exclude options to specify files for inclusion
1854     and exclusion when recursing.
1855    
1856     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1857     Hopefully, it now does.
1858    
1859     12. Missing cast in pcre_study().
1860    
1861     13. Added an "uninstall" target to the makefile.
1862    
1863     14. Replaced "extern" in the function prototypes in Makefile.in with
1864     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1865     world, but is set differently for Windows.
1866    
1867     15. Added a second compiling function called pcre_compile2(). The only
1868     difference is that it has an extra argument, which is a pointer to an
1869     integer error code. When there is a compile-time failure, this is set
1870     non-zero, in addition to the error test pointer being set to point to an
1871     error message. The new argument may be NULL if no error number is required
1872     (but then you may as well call pcre_compile(), which is now just a
1873     wrapper). This facility is provided because some applications need a
1874     numeric error indication, but it has also enabled me to tidy up the way
1875     compile-time errors are handled in the POSIX wrapper.
1876    
1877     16. Added VPATH=.libs to the makefile; this should help when building with one
1878     prefix path and installing with another. (Or so I'm told by someone who
1879     knows more about this stuff than I do.)
1880    
1881     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1882     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1883     match everything, including newlines. This is not POSIX-compatible, but
1884     somebody wanted the feature. From pcretest it can be activated by using
1885     both the P and the s flags.
1886    
1887     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1888    
1889     19. libpcre.pc was being incorrectly installed as executable.
1890    
1891     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1892     it now also looks for '\r' so that it will work unmodified on Windows.
1893    
1894     21. Added Google's contributed C++ wrapper to the distribution.
1895    
1896     22. Added some untidy missing memory free() calls in pcretest, to keep
1897     Electric Fence happy when testing.
1898    
1899    
1900    
1901 nigel 75 Version 5.0 13-Sep-04
1902     ---------------------
1903    
1904     1. Internal change: literal characters are no longer packed up into items
1905     containing multiple characters in a single byte-string. Each character
1906     is now matched using a separate opcode. However, there may be more than one
1907     byte in the character in UTF-8 mode.
1908    
1909     2. The pcre_callout_block structure has two new fields: pattern_position and
1910     next_item_length. These contain the offset in the pattern to the next match
1911     item, and its length, respectively.
1912    
1913     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1914     insertion of callouts before each pattern item. Added the /C option to
1915     pcretest to make use of this.
1916    
1917     4. On the advice of a Windows user, the lines
1918    
1919     #if defined(_WIN32) || defined(WIN32)
1920     _setmode( _fileno( stdout ), 0x8000 );
1921     #endif /* defined(_WIN32) || defined(WIN32) */
1922    
1923     have been added to the source of pcretest. This apparently does useful
1924     magic in relation to line terminators.
1925    
1926     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1927     for the benefit of those environments where the "b" makes a difference.
1928    
1929     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1930     to know about it. I have put a hack into configure.in that adds in code
1931     to set GCC=yes if CC=icc. This seems to end up at a point in the
1932     generated configure script that is early enough to affect the setting of
1933     compiler options, which is what is needed, but I have no means of testing
1934     whether it really works. (The user who reported this had patched the
1935     generated configure script, which of course I cannot do.)
1936    
1937     LATER: After change 22 below (new libtool files), the configure script
1938     seems to know about icc (and also ecc). Therefore, I have commented out
1939     this hack in configure.in.
1940    
1941     7. Added support for pkg-config (2 patches were sent in).
1942    
1943     8. Negated POSIX character classes that used a combination of internal tables
1944     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1945     [[:^ascii]]. Typically, they would match almost any characters. The other
1946     POSIX classes were not broken in this way.
1947    
1948     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1949     to find the match, as PCRE was deluded into thinking that the match had to
1950     start at the start point or following a newline. The same bug applied to
1951     patterns with negative forward assertions or any backward assertions
1952     preceding ".*" at the start, unless the pattern required a fixed first
1953     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1954    
1955     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1956     starting at the last subject character, bytes beyond the end of the subject
1957     string were read.
1958    
1959     11. Renamed the variable "class" as "classbits" to make life easier for C++
1960     users. (Previously there was a macro definition, but it apparently wasn't
1961     enough.)
1962    
1963     12. Added the new field "tables" to the extra data so that tables can be passed
1964     in at exec time, or the internal tables can be re-selected. This allows
1965     a compiled regex to be saved and re-used at a later time by a different
1966     program that might have everything at different addresses.
1967    
1968     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1969     -R library as well as a -L library.
1970    
1971     14. The debugging options of pcretest (-d on the command line or D on a
1972     pattern) showed incorrect output for anything following an extended class
1973     that contained multibyte characters and which was followed by a quantifier.
1974    
1975     15. Added optional support for general category Unicode character properties
1976     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1977     support. It adds about 90K to the size of the library. The meanings of the
1978     inbuilt class escapes such as \d and \s have NOT been changed.
1979    
1980     16. Updated pcredemo.c to include calls to free() to release the memory for the
1981     compiled pattern.
1982    
1983     17. The generated file chartables.c was being created in the source directory
1984     instead of in the building directory. This caused the build to fail if the
1985     source directory was different from the building directory, and was
1986     read-only.
1987    
1988     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1989     file. No doubt somebody will tell me if they don't make sense... Also added
1990     Dan Mooney's comments about building on OpenVMS.
1991    
1992     19. Added support for partial matching via the PCRE_PARTIAL option for
1993     pcre_exec() and the \P data escape in pcretest.
1994    
1995     20. Extended pcretest with 3 new pattern features:
1996    
1997     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1998     write the compiled pattern to the file whose name is "rest-of-line".
1999     This is a straight binary dump of the data, with the saved pointer to
2000     the character tables forced to be NULL. The study data, if any, is
2001     written too. After writing, pcretest reads a new pattern.
2002    
2003     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
2004     compiled pattern from the given file. There must not be any
2005     occurrences of "<" in the file name (pretty unlikely); if there are,
2006     pcretest will instead treat the initial "<" as a pattern delimiter.
2007     After reading in the pattern, pcretest goes on to read data lines as
2008     usual.
2009    
2010     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
2011     and 16-bit fields in a compiled pattern, to simulate a pattern that
2012     was compiled on a host of opposite endianness.
2013    
2014     21. The pcre-exec() function can now cope with patterns that were compiled on
2015     hosts of opposite endianness, with this restriction:
2016    
2017     As for any compiled expression that is saved and used later, the tables
2018     pointer field cannot be preserved; the extra_data field in the arguments
2019     to pcre_exec() should be used to pass in a tables address if a value
2020     other than the default internal tables were used at compile time.
2021    
2022     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
2023     now diagnosed as an error. Previously, most of the time, a negative number
2024     would have been treated as zero, but if in addition "ovector" was passed as
2025     NULL, a crash could occur.
2026    
2027     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
2028     new versions from the libtool 1.5 distribution (the last one is a copy of
2029     a file called libtool.m4). This seems to have fixed the need to patch
2030     "configure" to support Darwin 1.3 (which I used to do). However, I still
2031     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
2032     workstation).
2033    
2034     24. Changed the PCRE licence to be the more standard "BSD" licence.
2035    
2036    
2037 nigel 73 Version 4.5 01-Dec-03
2038     ---------------------
2039    
2040     1. There has been some re-arrangement of the code for the match() function so
2041     that it can be compiled in a version that does not call itself recursively.
2042     Instead, it keeps those local variables that need separate instances for
2043     each "recursion" in a frame on the heap, and gets/frees frames whenever it
2044     needs to "recurse". Keeping track of where control must go is done by means
2045     of setjmp/longjmp. The whole thing is implemented by a set of macros that
2046     hide most of the details from the main code, and operates only if
2047     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
2048     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
2049     operating.
2050    
2051     To make it easier for callers to provide specially tailored get/free
2052     functions for this usage, two new functions, pcre_stack_malloc, and
2053     pcre_stack_free, are used. They are always called in strict stacking order,
2054     and the size of block requested is always the same.
2055    
2056     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
2057     PCRE has been compiled to use the stack or the heap for recursion. The
2058     -C option of pcretest uses this to show which version is compiled.
2059    
2060     A new data escape \S, is added to pcretest; it causes the amounts of store
2061     obtained and freed by both kinds of malloc/free at match time to be added
2062     to the output.
2063    
2064     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
2065     what's available on my current Linux desktop machine.
2066    
2067     3. When matching a UTF-8 string, the test for a valid string at the start has
2068     been extended. If start_offset is not zero, PCRE now checks that it points
2069     to a byte that is the start of a UTF-8 character. If not, it returns
2070     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
2071     this is necessary because there may be backward assertions in the pattern.
2072     When matching the same subject several times, it may save resources to use
2073     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
2074    
2075     4. The code for checking the validity of UTF-8 strings has been tightened so
2076     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
2077     containing "overlong sequences".
2078    
2079     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
2080     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
2081     should have been "&", but it just so happened that all the cases this let
2082     through by mistake were picked up later in the function.
2083    
2084     6. I had used a variable called "isblank" - this is a C99 function, causing
2085     some compilers to warn. To avoid this, I renamed it (as "blankclass").
2086    
2087     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
2088     prompting; (b) run "./pcretest /dev/null" at the start of the test script
2089     so the version is shown; (c) stop "make test" echoing "./RunTest".
2090    
2091     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
2092    
2093     9. The prototype for memmove() for systems that don't have it was using
2094     size_t, but the inclusion of the header that defines size_t was later. I've
2095     moved the #includes for the C headers earlier to avoid this.
2096    
2097     10. Added some adjustments to the code to make it easier to compiler on certain
2098     special systems:
2099    
2100     (a) Some "const" qualifiers were missing.
2101     (b) Added the macro EXPORT before all exported functions; by default this
2102     is defined to be empty.
2103     (c) Changed the dftables auxiliary program (that builds chartables.c) so
2104     that it reads its output file name as an argument instead of writing
2105     to the standard output and assuming this can be redirected.
2106    
2107     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
2108     class containing characters with values greater than 255, PCRE compilation
2109     went into a loop.
2110    
2111     12. A recursive reference to a subpattern that was within another subpattern
2112     that had a minimum quantifier of zero caused PCRE to crash. For example,
2113     (x(y(?2))z)? provoked this bug with a subject that got as far as the
2114     recursion. If the recursively-called subpattern itself had a zero repeat,
2115     that was OK.
2116    
2117     13. In pcretest, the buffer for reading a data line was set at 30K, but the
2118     buffer into which it was copied (for escape processing) was still set at
2119     1024, so long lines caused crashes.
2120    
2121     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
2122     "internal error: code overflow...". This applied to any character class
2123     that was followed by a possessive quantifier.
2124    
2125     15. Modified the Makefile to add libpcre.la as a prerequisite for
2126     libpcreposix.la because I was told this is needed for a parallel build to
2127     work.
2128    
2129     16. If a pattern that contained .* following optional items at the start was
2130     studied, the wrong optimizing data was generated, leading to matching
2131     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
2132     matching string must start with a or b or c. The correct conclusion for
2133     this pattern is that a match can start with any character.
2134    
2135    
2136 nigel 71 Version 4.4 13-Aug-03
2137     ---------------------
2138    
2139     1. In UTF-8 mode, a character class containing characters with values between
2140     127 and 255 was not handled correctly if the compiled pattern was studied.
2141     In fixing this, I have also improved the studying algorithm for such
2142     classes (slightly).
2143    
2144     2. Three internal functions had redundant arguments passed to them. Removal
2145     might give a very teeny performance improvement.
2146    
2147     3. Documentation bug: the value of the capture_top field in a callout is *one
2148     more than* the number of the hightest numbered captured substring.
2149    
2150     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
2151     in incorrectly linking with a previously installed version. They now link
2152     explicitly with libpcre.la.
2153    
2154     5. configure.in no longer needs to recognize Cygwin specially.
2155    
2156     6. A problem in pcre.in for Windows platforms is fixed.
2157    
2158     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
2159     pcretest, it used to include the size of the study block as part of its
2160     output. Unfortunately, the structure contains a field that has a different
2161     size on different hardware architectures. This meant that the tests that
2162     showed this size failed. As the block is currently always of a fixed size,
2163     this information isn't actually particularly useful in pcretest output, so
2164     I have just removed it.
2165    
2166     8. Three pre-processor statements accidentally did not start in column 1.
2167     Sadly, there are *still* compilers around that complain, even though
2168     standard C has not required this for well over a decade. Sigh.
2169    
2170     9. In pcretest, the code for checking callouts passed small integers in the
2171     callout_data field, which is a void * field. However, some picky compilers
2172     complained about the casts involved for this on 64-bit systems. Now
2173     pcretest passes the address of the small integer instead, which should get
2174     rid of the warnings.
2175    
2176     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2177     both compile and run time, and gives an error if an invalid UTF-8 sequence
2178     is found. There is a option for disabling this check in cases where the
2179     string is known to be correct and/or the maximum performance is wanted.
2180    
2181     11. In response to a bug report, I changed one line in Makefile.in from
2182    
2183     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2184     to
2185     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2186    
2187     to look similar to other lines, but I have no way of telling whether this
2188     is the right thing to do, as I do not use Windows. No doubt I'll get told
2189     if it's wrong...
2190    
2191    
2192 nigel 69 Version 4.3 21-May-03
2193     ---------------------
2194    
2195     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2196     Makefile.
2197    
2198     2. Some refactoring to improve the quality of the code:
2199    
2200     (i) The utf8_table... variables are now declared "const".
2201    
2202     (ii) The code for \cx, which used the "case flipping" table to upper case
2203     lower case letters, now just substracts 32. This is ASCII-specific,
2204     but the whole concept of \cx is ASCII-specific, so it seems
2205     reasonable.
2206    
2207     (iii) PCRE was using its character types table to recognize decimal and
2208     hexadecimal digits in the pattern. This is silly, because it handles
2209     only 0-9, a-f, and A-F, but the character types table is locale-
2210     specific, which means strange things might happen. A private
2211     table is now used for this - though it costs 256 bytes, a table is
2212     much faster than multiple explicit tests. Of course, the standard
2213     character types table is still used for matching digits in subject
2214     strings against \d.
2215    
2216     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2217     ending in _t are). So I've renamed it as ESC_tee.
2218    
2219     3. The first argument for regexec() in the POSIX wrapper should have been
2220     defined as "const".
2221    
2222     4. Changed pcretest to use malloc() for its buffers so that they can be
2223     Electric Fenced for debugging.
2224    
2225     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2226     to read one or more bytes before the start of the subject string. Often this
2227     had no effect on PCRE's behaviour, but in some circumstances it could
2228     provoke a segmentation fault.
2229    
2230     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2231     to try to read one or more bytes before the start of the subject string.
2232    
2233     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2234     UTF-8 support could misbehave in various ways if the subject string
2235     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2236     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2237     back over UTF-8 characters.)
2238    
2239    
2240 nigel 67 Version 4.2 14-Apr-03
2241     ---------------------
2242    
2243     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2244    
2245     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2246     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2247     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2248     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2249     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2250     and BUILD_EXEEXT
2251     Note: automatic setting of the BUILD variables is not yet working
2252     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2253     compile-time but not at link-time
2254     [LINK]: use for linking executables only
2255     make different versions for Windows and non-Windows
2256     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2257     libraries
2258     [LINK_FOR_BUILD]: new variable
2259     [OBJEXT]: use throughout
2260     [EXEEXT]: use throughout
2261     <winshared>: new target
2262     <wininstall>: new target
2263     <dftables.o>: use native compiler
2264     <dftables>: use native linker
2265     <install>: handle Windows platform correctly
2266     <clean>: ditto
2267     <check>: ditto
2268     copy DLL to top builddir before testing
2269    
2270     As part of these changes, -no-undefined was removed again. This was reported
2271     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2272     in any case.
2273    
2274     3. Some tidies to get rid of compiler warnings:
2275    
2276     . In the match_data structure, match_limit was an unsigned long int, whereas
2277     match_call_count was an int. I've made them both unsigned long ints.
2278    
2279     . In pcretest the fact that a const uschar * doesn't automatically cast to
2280     a void * provoked a warning.
2281    
2282     . Turning on some more compiler warnings threw up some "shadow" variables
2283     and a few more missing casts.
2284    
2285     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2286     option, a class that contained a single character with a value between 128
2287     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2288    
2289     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2290     option, a class that contained several characters, but with at least one
2291     whose value was between 128 and 255 caused PCRE to crash.
2292    
2293    
2294 nigel 65 Version 4.1 12-Mar-03
2295     ---------------------
2296 nigel 63
2297 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2298     needed, and a string in dftables.c that was longer than standard compilers are
2299     required to support.
2300    
2301     2. Compiling with Sun's compiler found a few more places where the code could
2302     be tidied up in order to avoid warnings.
2303    
2304     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2305     first of these names is deprecated in the latest Autoconf in favour of the name
2306     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2307     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2308     analogy I have changed it to CFLAGS_FOR_BUILD.
2309    
2310     4. Added -no-undefined to the linking command in the Makefile, because this is
2311     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2312     linking step for the pcreposix library.
2313    
2314     5. PCRE was failing to diagnose the case of two named groups with the same
2315     name.
2316    
2317     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2318     literal character that is needed in the subject for a match, and scans along to
2319     ensure that it is present before embarking on the full matching process. This
2320     saves time in cases of nested unlimited repeats that are never going to match.
2321     Problem: the scan can take a lot of time if the subject is very long (e.g.
2322     megabytes), thus penalizing straightforward matches. It is now done only if the
2323     amount of subject to be scanned is less than 1000 bytes.
2324    
2325     7. A lesser problem with the same optimization is that it was recording the
2326     first character of an anchored pattern as "needed", thus provoking a search
2327     right along the subject, even when the first match of the pattern was going to
2328     fail. The "needed" character is now not set for anchored patterns, unless it
2329     follows something in the pattern that is of non-fixed length. Thus, it still
2330     fulfils its original purpose of finding quick non-matches in cases of nested
2331     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2332    
2333    
2334     Version 4.0 17-Feb-03
2335     ---------------------
2336    
2337 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2338     extended to the end of string, PCRE compiled incorrect data. This could lead to
2339     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2340    
2341     2. Moved to autoconf 2.53 and libtool 1.4.2.
2342    
2343     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2344     the special perltest8 script is no longer needed - all the tests can be run
2345     from a single perltest script.
2346    
2347     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2348     by \s. It has now been removed in PCRE. This means it isn't recognized as
2349     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2350     class [:space:] *does* include VT, thereby creating a mess.
2351    
2352     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2353     space and tab.
2354    
2355     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2356     its new features into the main test script, reducing the number of scripts.
2357    
2358     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2359     were backward compatible, and made the (?i) apply to the whole pattern, as if
2360     /i were given. Now it behaves more logically, and applies the option setting
2361     only to what follows. PCRE has been changed to follow suit. However, if it
2362     finds options settings right at the start of the pattern, it extracts them into
2363     the global options, as before. Thus, they show up in the info data.
2364    
2365     8. Added support for the \Q...\E escape sequence. Characters in between are
2366     treated as literals. This is slightly different from Perl in that $ and @ are
2367     also handled as literals inside the quotes. In Perl, they will cause variable
2368     interpolation. Note the following examples:
2369    
2370     Pattern PCRE matches Perl matches
2371    
2372     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2373     \Qabc\$xyz\E abc\$xyz abc\$xyz
2374     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2375    
2376     For compatibility with Perl, \Q...\E sequences are recognized inside character
2377     classes as well as outside them.
2378    
2379     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2380     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2381     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2382     signed/unsigned warnings.
2383    
2384     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2385     option for pcretest, so I've replaced it by a simple function that does just
2386     that job.
2387    
2388     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2389     "pcregrep -".
2390    
2391     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2392     Java package. This provides some syntactic sugar for simple cases of what my
2393     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2394     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2395     item, you can use this simplified notation. Note that only makes sense with
2396     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2397     greediness, whatever the setting of the PCRE_UNGREEDY option.
2398    
2399     13. A change of greediness default within a pattern was not taking effect at
2400     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2401     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2402     was abstracted outside.
2403    
2404     14. PCRE now supports the \G assertion. It is true when the current matching
2405     position is at the start point of the match. This differs from \A when the
2406     starting offset is non-zero. Used with the /g option of pcretest (or similar
2407     code), it works in the same way as it does for Perl's /g option. If all
2408     alternatives of a regex begin with \G, the expression is anchored to the start
2409     match position, and the "anchored" flag is set in the compiled expression.
2410    
2411     15. Some bugs concerning the handling of certain option changes within patterns
2412     have been fixed. These applied to options other than (?ims). For example,
2413     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2414     been the other way round. Some of this was related to change 7 above.
2415    
2416     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2417     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2418     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2419     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2420    
2421     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2422     mode. Unlike ".", it always matches newline, whatever the setting of
2423     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2424     assertions. Perl allows it, but it doesn't (in general) work because it can't
2425     calculate the length of the lookbehind. At least, that's the case for Perl
2426     5.8.0 - I've been told they are going to document that it doesn't work in
2427     future.
2428    
2429     18. Added an error diagnosis for escapes that PCRE does not support: these are
2430     \L, \l, \N, \P, \p, \U, \u, and \X.
2431    
2432     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2433     reading past the end of the pattern in cases such as /[abcd/.
2434    
2435     20. PCRE was getting more memory than necessary for patterns with classes that
2436     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2437    
2438     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2439     compiling PCRE for use with Virtual Pascal.
2440    
2441     22. Small fix to the Makefile to make it work properly if the build is done
2442     outside the source tree.
2443    
2444     23. Added a new extension: a condition to go with recursion. If a conditional
2445     subpattern starts with (?(R) the "true" branch is used if recursion has
2446     happened, whereas the "false" branch is used only at the top level.
2447    
2448     24. When there was a very long string of literal characters (over 255 bytes
2449     without UTF support, over 250 bytes with UTF support), the computation of how
2450     much memory was required could be incorrect, leading to segfaults or other
2451     strange effects.
2452    
2453     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2454     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2455     there was a subsequent back reference to those brackets. This meant that, for
2456     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2457     possible to check for precisely this case. All we can do is abandon the
2458     optimization if .* occurs inside capturing brackets when there are any back
2459     references whatsoever. (See below for a better fix that came later.)
2460    
2461     26. The handling of the optimization for finding the first character of a
2462     non-anchored pattern, and for finding a character that is required later in the
2463     match were failing in some cases. This didn't break the matching; it just
2464     failed to optimize when it could. The way this is done has been re-implemented.
2465    
2466     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2467    
2468     28. Added a new feature that provides some of the functionality that Perl
2469     provides with (?{...}). The facility is termed a "callout". The way it is done
2470     in PCRE is for the caller to provide an optional function, by setting
2471     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2472     global variable. By default it is unset, which disables all calling out. To get
2473     the function called, the regex must include (?C) at appropriate points. This
2474     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2475     This provides a means of identifying different callout points. When PCRE
2476     reaches such a point in the regex, if pcre_callout has been set, the external
2477     function is called. It is provided with data in a structure called
2478     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2479     matching continues; if it returns a non-zero value, the match at the current
2480     point fails. However, backtracking will occur if possible. [This was changed
2481     later and other features added - see item 49 below.]
2482    
2483     29. pcretest is upgraded to test the callout functionality. It provides a
2484     callout function that displays information. By default, it shows the start of
2485     the match and the current position in the text. There are some new data escapes
2486     to vary what happens:
2487    
2488     \C+ in addition, show current contents of captured substrings
2489     \C- do not supply a callout function
2490     \C!n return 1 when callout number n is reached
2491     \C!n!m return 1 when callout number n is reached for the mth time
2492    
2493     30. If pcregrep was called with the -l option and just a single file name, it
2494     output "<stdin>" if a match was found, instead of the file name.
2495    
2496     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2497     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2498     pcre_exec(). This saves a malloc/free per call. The default value of
2499     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2500     when configuring.
2501    
2502     32. The default maximum size of a compiled pattern is 64K. There have been a
2503     few cases of people hitting this limit. The code now uses macros to handle the
2504     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2505     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2506     configuring. Tests 2 and 5 work only with 2-byte links because they output
2507     debugging information about compiled patterns.
2508    
2509     33. Internal code re-arrangements:
2510    
2511     (a) Moved the debugging function for printing out a compiled regex into
2512     its own source file (printint.c) and used #include to pull it into
2513     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2514     separate copies.
2515    
2516     (b) Defined the list of op-code names for debugging as a macro in
2517     internal.h so that it is next to the definition of the opcodes.
2518    
2519     (c) Defined a table of op-code lengths for simpler skipping along compiled
2520     code. This is again a macro in internal.h so that it is next to the
2521     definition of the opcodes.
2522    
2523     34. Added support for recursive calls to individual subpatterns, along the
2524     lines of Robin Houston's patch (but implemented somewhat differently).
2525    
2526     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2527     allow it to read and process whole directories in Win32. This code was
2528     contributed by Lionel Fourquaux; it has not been tested by me.
2529    
2530     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2531     used to name a group. Names consist of alphanumerics and underscores, and must
2532     be unique. Back references use the syntax (?P=name) and recursive calls use
2533     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2534     numbers. The function pcre_fullinfo() can be used after compilation to extract
2535     a name/number map. There are three relevant calls:
2536    
2537     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2538     PCRE_INFO_NAMECOUNT yields the number of entries
2539     PCRE_INFO_NAMETABLE yields a pointer to the map.
2540    
2541     The map is a vector of fixed-size entries. The size of each entry depends on
2542     the length of the longest name used. The first two bytes of each entry are the
2543     group number, most significant byte first. There follows the corresponding
2544     name, zero terminated. The names are in alphabetical order.
2545    
2546     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2547     case instead of 255. Making it the same both with and without UTF-8 support
2548     means that the same test output works with both.
2549    
2550     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2551     calling malloc() with a zero argument.
2552    
2553     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2554     optimization. I've improved things by keeping a bitmap of backreferences with
2555     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2556     fact referenced, the optimization can be applied. It is unlikely that a
2557     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2558     the match to follow \n) will appear inside brackets with a number greater than
2559     31, but if it does, any back reference > 31 suppresses the optimization.
2560    
2561     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2562     of disabling numbered capturing parentheses. Any opening parenthesis that is
2563     not followed by ? behaves as if it were followed by ?: but named parentheses
2564     can still be used for capturing (and they will acquire numbers in the usual
2565     way).
2566    
2567     41. Redesigned the return codes from the match() function into yes/no/error so
2568     that errors can be passed back from deep inside the nested calls. A malloc
2569     failure while inside a recursive subpattern call now causes the
2570     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2571    
2572     42. It is now possible to set a limit on the number of times the match()
2573     function is called in a call to pcre_exec(). This facility makes it possible to
2574     limit the amount of recursion and backtracking, though not in a directly
2575     obvious way, because the match() function is used in a number of different
2576     circumstances. The count starts from zero for each position in the subject
2577     string (for non-anchored patterns). The default limit is, for compatibility, a
2578     large number, namely 10 000 000. You can change this in two ways:
2579    
2580     (a) When configuring PCRE before making, you can use --with-match-limit=n
2581     to set a default value for the compiled library.
2582    
2583     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2584     a different value is set. See 45 below.
2585    
2586     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2587    
2588     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2589     of things that can be changed at compile time. The first argument specifies
2590     what is wanted and the second points to where the information is to be placed.
2591     The current list of available information is:
2592    
2593     PCRE_CONFIG_UTF8
2594    
2595     The output is an integer that is set to one if UTF-8 support is available;
2596     otherwise it is set to zero.
2597    
2598     PCRE_CONFIG_NEWLINE
2599    
2600     The output is an integer that it set to the value of the code that is used for
2601     newline. It is either LF (10) or CR (13).
2602    
2603     PCRE_CONFIG_LINK_SIZE
2604    
2605     The output is an integer that contains the number of bytes used for internal
2606     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2607    
2608     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2609    
2610     The output is an integer that contains the threshold above which the POSIX
2611     interface uses malloc() for output vectors. See item 31 above.
2612    
2613     PCRE_CONFIG_MATCH_LIMIT
2614    
2615     The output is an unsigned integer that contains the default limit of the number
2616     of match() calls in a pcre_exec() execution. See 42 above.
2617    
2618     44. pcretest has been upgraded by the addition of the -C option. This causes it
2619     to extract all the available output from the new pcre_config() function, and to
2620     output it. The program then exits immediately.
2621    
2622     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2623     order to support additional features. One way would have been to define
2624     pcre_exec2() (for example) with extra arguments, but this would not have been
2625     extensible, and would also have required all calls to the original function to
2626     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2627     is used for passing in "extra" data from pcre_study().
2628    
2629     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2630     contains the following fields:
2631    
2632     flags a bitmap indicating which of the following fields are set
2633     study_data opaque data from pcre_study()
2634     match_limit a way of specifying a limit on match() calls for a specific
2635     call to pcre_exec()
2636     callout_data data for callouts (see 49 below)
2637    
2638     The flag bits are also defined in pcre.h, and are
2639    
2640     PCRE_EXTRA_STUDY_DATA
2641     PCRE_EXTRA_MATCH_LIMIT
2642     PCRE_EXTRA_CALLOUT_DATA
2643    
2644     The pcre_study() function now returns one of these new pcre_extra blocks, with
2645     the actual study data pointed to by the study_data field, and the
2646     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2647     before. That is, this change is entirely upwards-compatible and requires no
2648     change to existing code.
2649    
2650     If you want to pass in additional data to pcre_exec(), you can either place it
2651     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2652     block.
2653    
2654     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2655     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2656     times with different match limits, until it finds the minimum value needed for
2657     pcre_exec() to complete. The value is then output. This can be instructive; for
2658     most simple matches the number is quite small, but for pathological cases it
2659     gets very large very quickly.
2660    
2661     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2662     returns the size of the data block pointed to by the study_data field in a
2663     pcre_extra block, that is, the value that was passed as the argument to
2664     pcre_malloc() when PCRE was getting memory in which to place the information
2665     created by pcre_study(). The fourth argument should point to a size_t variable.
2666     pcretest has been extended so that this information is shown after a successful
2667     pcre_study() call when information about the compiled regex is being displayed.
2668    
2669     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2670     because what follows is always an absolute path. (Later: it turns out that this
2671     is more than cosmetic for MinGW, because it doesn't like empty path
2672     components.)
2673    
2674     49. Some changes have been made to the callout feature (see 28 above):
2675    
2676     (i) A callout function now has three choices for what it returns:
2677    
2678     0 => success, carry on matching
2679     > 0 => failure at this point, but backtrack if possible
2680     < 0 => serious error, return this value from pcre_exec()
2681    
2682     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2683     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2684     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2685     use by callout functions. It will never be used by PCRE itself.
2686    
2687     (ii) The pcre_extra structure (see 45 above) has a void * field called
2688     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2689     pcre_callout_block structure has a field of the same name. The contents of
2690     the field passed in the pcre_extra structure are passed to the callout
2691     function in the corresponding field in the callout block. This makes it
2692     easier to use the same callout-containing regex from multiple threads. For
2693     testing, the pcretest program has a new data escape
2694    
2695     \C*n pass the number n (may be negative) as callout_data
2696    
2697     If the callout function in pcretest receives a non-zero value as
2698     callout_data, it returns that value.
2699    
2700     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2701     there were some redundant $(CFLAGS) in commands that are now specified as
2702     $(LINK), which already includes $(CFLAGS).
2703    
2704     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2705     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2706     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2707     one-byte characters throughout. Note that case-insensitive matching applies
2708     only to characters whose values are less than 256. PCRE doesn't support the
2709     notion of cases for higher-valued characters.
2710    
2711     (i) A character class whose characters are all within 0-255 is handled as
2712     a bit map, and the map is inverted for negative classes. Previously, a
2713     character > 255 always failed to match such a class; however it should
2714     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2715    
2716     (ii) A negated character class with a single character < 255 is coded as
2717     "not this character" (OP_NOT). This wasn't working properly when the test
2718     character was multibyte, either singly or repeated.
2719    
2720     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2721     mode, for example: \x{100}{2,3}.
2722    
2723     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2724     singly or repeated) now correctly test multibyte characters. However,
2725     PCRE doesn't recognize any characters with values greater than 255 as
2726     digits, spaces, or word characters. Such characters always match \D, \S,
2727     and \W, and never match \d, \s, or \w.
2728    
2729     (v) Classes may now contain characters and character ranges with values
2730     greater than 255. For example: [ab\x{100}-\x{400}].
2731    
2732     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2733     PCRE in UTF-8 mode.
2734    
2735     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2736     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2737     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2738     value.)
2739    
2740     53. The single man page has become too large. I have therefore split it up into
2741     a number of separate man pages. These also give rise to individual HTML pages;
2742     these are now put in a separate directory, and there is an index.html page that
2743     lists them all. Some hyperlinking between the pages has been installed.
2744    
2745     54. Added convenience functions for handling named capturing parentheses.
2746    
2747     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2748     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2749     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2750     are faulted.
2751    
2752     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2753     calling configure. These values are used when compiling the dftables.c program
2754     which is run to generate the source of the default character tables. They
2755     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2756     you will need to set these values.
2757    
2758     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2759    
2760    
2761     Version 3.9 02-Jan-02
2762 nigel 61 ---------------------
2763    
2764     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2765    
2766     2. If --disable-static was given, the building process failed when trying to
2767     build pcretest and pcregrep. (For some reason it was using libtool to compile
2768     them, which is not right, as they aren't part of the library.)
2769    
2770    
2771 nigel 59 Version 3.8 18-Dec-01
2772     ---------------------
2773    
2774     1. The experimental UTF-8 code was completely screwed up. It was packing the
2775     bytes in the wrong order. How dumb can you get?
2776    
2777    
2778 nigel 57 Version 3.7 29-Oct-01
2779     ---------------------
2780    
2781     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2782     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2783     this didn't happen under Solaris 8, where I normally test things.
2784    
2785 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2786     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2787     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2788     this fix an hour or so after the initial 3.7 release.)
2789 nigel 57
2790 nigel 59
2791 nigel 55 Version 3.6 23-Oct-01
2792     ---------------------
2793    
2794     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2795     offsets passed as NULL with zero offset count.
2796    
2797     2. The config.guess and config.sub files had not been updated when I moved to
2798     the latest autoconf.
2799    
2800    
2801 nigel 53 Version 3.5 15-Aug-01
2802     ---------------------
2803 nigel 5
2804 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2805     had been forgotten.
2806    
2807     2. By using declared but undefined structures, we can avoid using "void"
2808     definitions in pcre.h while keeping the internal definitions of the structures
2809     private.
2810    
2811     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2812     user point of view, this means that both static and shared libraries are built
2813     by default, but this can be individually controlled. More of the work of
2814     handling this static/shared cases is now inside libtool instead of PCRE's make
2815     file.
2816    
2817     4. The pcretest utility is now installed along with pcregrep because it is
2818     useful for users (to test regexs) and by doing this, it automatically gets
2819     relinked by libtool. The documentation has been turned into a man page, so
2820     there are now .1, .txt, and .html versions in /doc.
2821    
2822     5. Upgrades to pcregrep:
2823     (i) Added long-form option names like gnu grep.
2824     (ii) Added --help to list all options with an explanatory phrase.
2825     (iii) Added -r, --recursive to recurse into sub-directories.
2826     (iv) Added -f, --file to read patterns from a file.
2827    
2828     6. pcre_exec() was referring to its "code" argument before testing that
2829     argument for NULL (and giving an error if it was NULL).
2830    
2831     7. Upgraded Makefile.in to allow for compiling in a different directory from
2832     the source directory.
2833    
2834     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2835     options bits, the pointer it was passed was to an int instead of to an unsigned
2836     long int. This mattered only on 64-bit systems.
2837    
2838     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2839     generated) instead of pcre.in, which it its source. Also made the same change
2840     in several of the .c files.
2841    
2842     10. A new release of gcc defines printf() as a macro, which broke pcretest
2843     because it had an ifdef in the middle of a string argument for printf(). Fixed
2844     by using separate calls to printf().
2845    
2846     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2847     script, to force use of CR or LF instead of \n in the source. On non-Unix
2848     systems, the value can be set in config.h.
2849    
2850     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2851     absolute limit. Changed the text of the error message to make this clear, and
2852     likewise updated the man page.
2853    
2854     13. The limit of 99 on the number of capturing subpatterns has been removed.
2855     The new limit is 65535, which I hope will not be a "real" limit.
2856    
2857    
2858 nigel 51 Version 3.4 22-Aug-00
2859     ---------------------
2860    
2861     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2862    
2863     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2864    
2865    
2866 nigel 49 Version 3.3 01-Aug-00
2867     ---------------------
2868    
2869     1. If an octal character was given, but the value was greater than \377, it
2870     was not getting masked to the least significant bits, as documented. This could
2871     lead to crashes in some systems.
2872    
2873     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2874     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2875    
2876     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2877     These just pass their arguments on to (pcre_free)(), but they are provided
2878     because some uses of PCRE bind it to non-C systems that can call its functions,
2879     but cannot call free() or pcre_free() directly.
2880    
2881     4. Add "make test" as a synonym for "make check". Corrected some comments in
2882     the Makefile.
2883    
2884     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2885     Makefile.
2886    
2887     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2888     command called pgrep for grepping around the active processes.
2889    
2890     7. Added the beginnings of support for UTF-8 character strings.
2891    
2892     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2893     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2894     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2895     out for the ar command.)
2896    
2897    
2898 nigel 47 Version 3.2 12-May-00
2899     ---------------------
2900    
2901     This is purely a bug fixing release.
2902    
2903     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2904     of ZA. This was just one example of several cases that could provoke this bug,
2905     which was introduced by change 9 of version 2.00. The code for breaking
2906     infinite loops after an iteration that matches an empty string was't working
2907     correctly.
2908    
2909     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2910     when matched against abbab (for example). After matching an empty string, it
2911     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2912     caused it to match further down the string than it should.
2913    
2914     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2915     was there because it doesn't seem to be needed, and it causes trouble on some
2916     systems, as it is not a Standard C header. It has been removed.
2917    
2918     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2919     were reported on the Macintosh. The changes were from
2920    
2921     while ((c = *(++ptr)) != 0 && c != '\n');
2922     to
2923     while ((c = *(++ptr)) != 0 && c != '\n') ;
2924    
2925     Totally extraordinary, but if that's what it takes...
2926    
2927     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2928     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2929     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2930     assumes the way PCRE uses memmove() (always moving upwards).
2931    
2932     6. PCRE is being used in one environment where strchr() is not available. There
2933     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2934     faster code anyway.
2935    
2936    
2937 nigel 45 Version 3.1 09-Feb-00
2938     ---------------------
2939    
2940     The only change in this release is the fixing of some bugs in Makefile.in for
2941     the "install" target:
2942    
2943     (1) It was failing to install pcreposix.h.
2944    
2945     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2946    
2947    
2948 nigel 43 Version 3.0 01-Feb-00
2949     ---------------------
2950 nigel 41
2951     1. Add support for the /+ modifier to perltest (to output $` like it does in
2952     pcretest).
2953    
2954     2. Add support for the /g modifier to perltest.
2955    
2956     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2957     matches null strings.
2958    
2959     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2960     pattern. Perl treats empty patterns specially - it reuses the most recent
2961     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2962     effect.
2963    
2964     5. The POSIX interface was broken in that it was just handing over the POSIX
2965     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2966     required a bigger vector, with some working space on the end. This means that
2967     the POSIX wrapper now has to get and free some memory, and copy the results.
2968    
2969 nigel 43 6. Added some simple autoconf support, placing the test data and the
2970     documentation in separate directories, re-organizing some of the
2971     information files, and making it build pcre-config (a GNU standard). Also added
2972     libtool support for building PCRE as a shared library, which is now the
2973     default.
2974 nigel 41
2975 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2976     09 are not valid octal constants. Single digits will be used for minor values
2977     less than 10.
2978    
2979     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2980     existing programs that set these in the POSIX interface can use PCRE without
2981     modification.
2982    
2983     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2984     return all that pcre_info() returns, plus additional data. The pcre_info()
2985     function is retained for compatibility, but is considered to be obsolete.
2986    
2987     10. Added experimental recursion feature (?R) to handle one common case that
2988     Perl 5.6 will be able to do with (?p{...}).
2989    
2990     11. Added support for POSIX character classes like [:alpha:], which Perl is
2991     adopting.
2992    
2993    
2994 nigel 39 Version 2.08 31-Aug-99
2995     ----------------------
2996    
2997     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2998     trying to match at the startoffset position, but instead was moving forward to
2999     the next newline as if a previous match had failed.
3000    
3001     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
3002     and could get into a loop if a null string was matched other than at the start
3003     of the subject.
3004    
3005     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
3006     be distinguished at compile time, and for completeness also added PCRE_DATE.
3007    
3008     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
3009     in GnuWin32 environments.
3010    
3011    
3012 nigel 37 Version 2.07 29-Jul-99
3013     ----------------------
3014    
3015     1. The documentation is now supplied in plain text form and HTML as well as in
3016     the form of man page sources.
3017    
3018     2. C++ compilers don't like assigning (void *) values to other pointer types.
3019     In particular this affects malloc(). Although there is no problem in Standard
3020     C, I've put in casts to keep C++ compilers happy.
3021    
3022     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
3023     should be (const char *).
3024    
3025     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
3026     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
3027     However, I haven't made this a standard facility. The documentation doesn't
3028     mention it, and the Makefile doesn't support it.
3029    
3030     5. The Makefile now contains an "install" target, with editable destinations at
3031     the top of the file. The pcretest program is not installed.
3032    
3033     6. pgrep -V now gives the PCRE version number and date.
3034    
3035     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
3036     causing the entire string to be ignored, instead of just the last character.
3037    
3038     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
3039     non-matching string, it can take a very, very long time, even for strings of
3040     quite modest length, because of the nested recursion. PCRE now does better in
3041     some of these cases. It does this by remembering the last required literal
3042     character in the pattern, and pre-searching the subject to ensure it is present
3043     before running the real match. In other words, it applies a heuristic to detect
3044     some types of certain failure quickly, and in the above example, if presented
3045     with a string that has no trailing " it gives "no match" very quickly.
3046    
3047     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
3048     other alternatives are tried instead.
3049    
3050    
3051 nigel 35 Version 2.06 09-Jun-99
3052     ----------------------
3053    
3054     1. Change pcretest's output for amount of store used to show just the code
3055     space, because the remainder (the data block) varies in size between 32-bit and
3056     64-bit systems.
3057    
3058     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
3059     start matching at. This allows lookbehinds to work when searching for multiple
3060     occurrences in a string.
3061    
3062     3. Added additional options to pcretest for testing multiple occurrences:
3063    
3064     /+ outputs the rest of the string that follows a match
3065     /g loops for multiple occurrences, using the new startoffset argument
3066     /G loops for multiple occurrences by passing an incremented pointer
3067    
3068     4. PCRE wasn't doing the "first character" optimization for patterns starting
3069     with \b or \B, though it was doing it for other lookbehind assertions. That is,
3070     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
3071     the letter 'x'. On long subject strings, this gives a significant speed-up.
3072    
3073    
3074 nigel 33 Version 2.05 21-Apr-99
3075     ----------------------
3076    
3077     1. Changed the type of magic_number from int to long int so that it works
3078     properly on 16-bit systems.
3079    
3080     2. Fixed a bug which caused patterns starting with .* not to work correctly
3081     when the subject string contained newline characters. PCRE was assuming
3082     anchoring for such patterns in all cases, which is not correct because .* will
3083     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
3084     DOTALL is set at top level; otherwise it knows that patterns starting with .*
3085     must be retried after every newline in the subject.
3086    
3087    
3088 nigel 31 Version 2.04 18-Feb-99
3089     ----------------------
3090    
3091     1. For parenthesized subpatterns with repeats whose minimum was zero, the
3092     computation of the store needed to hold the pattern was incorrect (too large).
3093     If such patterns were nested a few deep, this could multiply and become a real
3094     problem.
3095    
3096     2. Added /M option to pcretest to show the memory requirement of a specific
3097     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
3098    
3099     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
3100     compiled in such a way that the backtracking after subsequent failure was
3101     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
3102     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
3103    
3104    
3105 nigel 29 Version 2.03 02-Feb-99
3106     ----------------------
3107    
3108     1. Fixed typo and small mistake in man page.
3109    
3110 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
3111     LICENCE file containing the conditions.
3112 nigel 29
3113     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
3114     Perl, that is the internal \ allows the delimiter to be included in the
3115     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
3116     the final delimiter, add \ to the end of the pattern (to test the error).
3117    
3118     4. Added the convenience functions for extracting substrings after a successful
3119     match. Updated pcretest to make it able to test these functions.
3120    
3121    
3122 nigel 27 Version 2.02 14-Jan-99
3123     ----------------------
3124    
3125     1. Initialized the working variables associated with each extraction so that
3126     their saving and restoring doesn't refer to uninitialized store.
3127    
3128     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
3129     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
3130     fix the problem.
3131    
3132     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
3133     calls, and wasn't printing the correct value for compiling calls. Increased the
3134     default value of LOOPREPEAT, and the number of significant figures in the
3135     times.
3136    
3137     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
3138    
3139     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
3140     a building problem on Windows NT with a FAT file system.
3141    
3142    
3143 nigel 25 Version 2.01 21-Oct-98
3144     ----------------------
3145    
3146     1. Changed the API for pcre_compile() to allow for the provision of a pointer
3147     to character tables built by pcre_maketables() in the current locale. If NULL
3148     is passed, the default tables are used.
3149    
3150    
3151 nigel 23 Version 2.00 24-Sep-98
3152 nigel 21 ----------------------
3153    
3154 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
3155     it any more.
3156    
3157     2. Allow quantification of (?>) groups, and make it work correctly.
3158    
3159     3. The first character computation wasn't working for (?>) groups.
3160    
3161     4. Correct the implementation of \Z (it is permitted to match on the \n at the
3162     end of the subject) and add 5.005's \z, which really does match only at the
3163     very end of the subject.
3164    
3165     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
3166    
3167     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
3168     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
3169     localized options. All options to pcre_study() were also removed.
3170    
3171     7. Add other new features from 5.005:
3172    
3173     $(?<= positive lookbehind
3174     $(?<! negative lookbehind
3175     (?imsx-imsx) added the unsetting capability
3176     such a setting is global if at outer level; local otherwise
3177     (?imsx-imsx:) non-capturing groups with option setting
3178     (?(cond)re|re) conditional pattern matching
3179    
3180     A backreference to itself in a repeated group matches the previous
3181     captured string.
3182    
3183     8. General tidying up of studying (both automatic and via "study")
3184     consequential on the addition of new assertions.
3185    
3186     9. As in 5.005, unlimited repeated groups that could match an empty substring
3187     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3188     runtime if any iteration does actually match an empty substring.
3189    
3190     10. Include the RunTest script in the distribution.
3191    
3192     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3193     discrepancies, some of which were old and were also with respect to 5.004. They
3194     have now been fixed.
3195    
3196    
3197     Version 1.09 28-Apr-98
3198     ----------------------
3199    
3200 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3201     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3202     program crashes, or just wrong answers. This did not apply to negated classes
3203     containing more than one character, or to minima other than one.
3204    
3205    
3206 nigel 19 Version 1.08 27-Mar-98
3207     ----------------------
3208    
3209     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3210    
3211     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3212     latter must appear before anything that relies on it in the pattern.
3213    
3214    
3215 nigel 17 Version 1.07 16-Feb-98
3216     ----------------------
3217    
3218     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3219     repeat of a potentially empty string).
3220    
3221    
3222 nigel 15 Version 1.06 23-Jan-98
3223     ----------------------
3224    
3225     1. Added Markus Oberhumer's little patches for C++.
3226    
3227     2. Literal strings longer than 255 characters were broken.
3228    
3229    
3230 nigel 13 Version 1.05 23-Dec-97
3231     ----------------------
3232    
3233     1. Negated character classes containing more than one character were failing if
3234     PCRE_CASELESS was set at run time.
3235    
3236    
3237 nigel 11 Version 1.04 19-Dec-97
3238     ----------------------
3239    
3240     1. Corrected the man page, where some "const" qualifiers had been omitted.
3241    
3242     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3243     input syntax.
3244    
3245     3. Fixed memory leak which occurred when a regex with back references was
3246     matched with an offsets vector that wasn't big enough. The temporary memory
3247     that is used in this case wasn't being freed if the match failed.
3248    
3249     4. Tidied pcretest to ensure it frees memory that it gets.
3250    
3251     5. Temporary memory was being obtained in the case where the passed offsets
3252     vector was exactly big enough.
3253    
3254     6. Corrected definition of offsetof() from change 5 below.
3255    
3256     7. I had screwed up change 6 below and broken the rules for the use of
3257     setjmp(). Now fixed.
3258    
3259    
3260 nigel 9 Version 1.03 18-Dec-97
3261     ----------------------
3262    
3263     1. A erroneous regex with a missing opening parenthesis was correctly
3264     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3265     on some systems.
3266    
3267     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3268     it was reported that one broken compiler failed on the former because "code" is
3269     also an independent variable.
3270    
3271     3. The erroneous regex a[]b caused an array overrun reference.
3272    
3273     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3274     fail on data ending with that character. (It was going on too far, and checking
3275     the next character, typically a binary zero.) This was specific to the
3276     optimized code for single-character negative classes.
3277    
3278     5. Added a contributed patch from the TIN world which does the following:
3279    
3280     + Add an undef for memmove, in case the the system defines a macro for it.
3281    
3282     + Add a definition of offsetof(), in case there isn't one. (I don't know
3283     the reason behind this - offsetof() is part of the ANSI standard - but
3284     it does no harm).
3285    
3286     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3287     most of the places where whitespace preceded '#'. I have given up and
3288     allowed the remaining 2 cases to be at the margin.
3289    
3290     + Rename some variables in pcre to eliminate shadowing. This seems very
3291     pedantic, but does no harm, of course.
3292    
3293     6. Moved the call to setjmp() into its own function, to get rid of warnings
3294     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3295    
3296     7. Constructs such as \d{8,} were compiling into the equivalent of
3297 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3298 nigel 9 outcome, but in this particular case used more store than had been allocated,
3299     which caused the bug to be discovered because it threw up an internal error.
3300    
3301     8. The debugging code in both pcre and pcretest for outputting the compiled
3302     form of a regex was going wrong in the case of back references followed by
3303     curly-bracketed repeats.
3304    
3305    
3306 nigel 7 Version 1.02 12-Dec-97
3307     ----------------------
3308    
3309     1. Typos in pcre.3 and comments in the source fixed.
3310    
3311     2. Applied a contributed patch to get rid of places where it used to remove
3312     'const' from variables, and fixed some signed/unsigned and uninitialized
3313     variable warnings.
3314    
3315     3. Added the "runtest" target to Makefile.
3316    
3317     4. Set default compiler flag to -O2 rather than just -O.
3318    
3319    
3320 nigel 5 Version 1.01 19-Nov-97
3321     ----------------------
3322    
3323     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3324     like /([ab]*)*/, that is, for classes with more than one character in them.
3325    
3326     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3327     as /((?>a*))*/ (a PCRE_EXTRA facility).
3328    
3329    
3330     Version 1.00 18-Nov-97
3331     ----------------------
3332    
3333     1. Added compile-time macros to support systems such as SunOS4 which don't have
3334     memmove() or strerror() but have other things that can be used instead.
3335    
3336     2. Arranged that "make clean" removes the executables.
3337    
3338    
3339 nigel 3 Version 0.99 27-Oct-97
3340     ----------------------
3341    
3342     1. Fixed bug in code for optimizing classes with only one character. It was
3343     initializing a 32-byte map regardless, which could cause it to run off the end
3344     of the memory it had got.
3345    
3346     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3347    
3348    
3349     Version 0.98 22-Oct-97
3350     ----------------------
3351    
3352     1. Fixed bug in code for handling temporary memory usage when there are more
3353     back references than supplied space in the ovector. This could cause segfaults.
3354    
3355    
3356     Version 0.97 21-Oct-97
3357     ----------------------
3358    
3359     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3360    
3361     2. Optimized negated single characters not to use a bit map.
3362    
3363     3. Brought error texts together as macro definitions; clarified some of them;
3364     fixed one that was wrong - it said "range out of order" when it meant "invalid
3365     escape sequence".
3366    
3367     4. Changed some char * arguments to const char *.
3368    
3369     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3370    
3371     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3372     pcretest.
3373    
3374    
3375     Version 0.96 16-Oct-97
3376     ----------------------
3377    
3378     1. Added a simple "pgrep" utility to the distribution.
3379    
3380     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3381     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3382     where "ddd" means "one or more decimal digits".
3383    
3384     3. Fixed serious bug. If a pattern had a back reference, but the call to
3385     pcre_exec() didn't supply a large enough ovector to record the related
3386     identifying subpattern, the match always failed. PCRE now remembers the number
3387     of the largest back reference, and gets some temporary memory in which to save
3388     the offsets during matching if necessary, in order to ensure that
3389     backreferences always work.
3390    
3391     4. Increased the compatibility with Perl in a number of ways:
3392    
3393     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3394     to request this handling. The option can be set at compile or exec time.
3395    
3396     (b) $ matches before a terminating newline by default; an option
3397     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3398     mode). The option can be set at compile or exec time.
3399    
3400     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3401     the same as Perl's. If the decimal number it represents is less than 10
3402     or there aren't that many previous left capturing parentheses, an octal
3403     escape is read. Inside a character class, it's always an octal escape,
3404     even if it is a single digit.
3405    
3406     (d) An escaped but undefined alphabetic character is taken as a literal,
3407     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3408     escapes.
3409    
3410     (e) {0} is now permitted. (The previous item is removed from the compiled
3411     pattern).
3412    
3413     5. Changed all the names of code files so that the basic parts are no longer
3414     than 10 characters, and abolished the teeny "globals.c" file.
3415    
3416     6. Changed the handling of character classes; they are now done with a 32-byte
3417     bit map always.
3418    
3419     7. Added the -d and /D options to pcretest to make it possible to look at the
3420     internals of compilation without having to recompile pcre.
3421    
3422    
3423     Version 0.95 23-Sep-97
3424     ----------------------
3425    
3426     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3427     \x20 at the start of a run of normal characters. These were being treated as
3428     real characters, instead of the source characters being re-checked.
3429    
3430    
3431     Version 0.94 18-Sep-97
3432     ----------------------
3433    
3434     1. The functions are now thread-safe, with the caveat that the global variables
3435     containing pointers to malloc() and free() or alternative functions are the
3436     same for all threads.
3437    
3438     2. Get pcre_study() to generate a bitmap of initial characters for non-
3439     anchored patterns when this is possible, and use it if passed to pcre_exec().
3440    
3441    
3442     Version 0.93 15-Sep-97
3443     ----------------------
3444    
3445     1. /(b)|(:+)/ was computing an incorrect first character.
3446    
3447     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3448     but not actually doing anything yet.
3449    
3450     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3451     as Perl does (e.g. [-az] or [az-]).
3452    
3453     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3454     all possible positions.
3455    
3456     5. Split up into different modules to avoid including unneeded functions in a
3457     compiled binary. However, compile and exec are still in one module. The "study"
3458     function is split off.
3459    
3460     6. The character tables are now in a separate module whose source is generated
3461     by an auxiliary program - but can then be edited by hand if required. There are
3462     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3463     toupper() in the code.
3464    
3465     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3466     make them global. Abolish the function for setting them, as the caller can now
3467     set them directly.
3468    
3469    
3470     Version 0.92 11-Sep-97
3471     ----------------------
3472    
3473     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3474     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3475    
3476     2. Caseless matching was not working in character classes if the characters in
3477     the pattern were in upper case.
3478    
3479     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3480    
3481     4. Make PCRE_ANCHORED public and accept as a compile option.
3482    
3483     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3484     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3485     pass them.
3486    
3487     6. Give an error if bad option bits passed at compile or run time.
3488    
3489     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3490     pcretest to cause it to pass that flag.
3491    
3492     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3493     options, and the first character, if set.
3494    
3495     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3496    
3497    
3498     Version 0.91 10-Sep-97
3499     ----------------------
3500    
3501     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3502     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3503    
3504     2. PCRE was looping on encountering an indefinitely repeated back reference to
3505     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3506     Perl does - treats the match as successful.
3507    
3508     ****

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