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Revision 400 - (hide annotations) (download)
Sat Mar 21 16:59:40 2009 UTC (5 years ago) by ph10
File size: 164014 byte(s)
Fix memory leak for -8 error during recursion.

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

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