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Revision 402 - (hide annotations) (download)
Sat Mar 21 17:26:03 2009 UTC (5 years, 7 months ago) by ph10
File size: 164206 byte(s)
Add missing #ifdef SUPPORT_UTF8 round heapframe::Xcharptr.

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

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