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Revision 378 - (hide annotations) (download)
Sun Mar 1 14:13:34 2009 UTC (5 years, 6 months ago) by ph10
File size: 161322 byte(s)
Make pcregrep with --colour show all matches in a line in colour.

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

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