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Revision 374 - (hide annotations) (download)
Fri Sep 5 16:42:28 2008 UTC (5 years, 11 months ago) by ph10
File size: 159727 byte(s)
Updates for 7.8 release

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

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