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Revision 369 - (hide annotations) (download)
Sun Aug 24 16:53:47 2008 UTC (6 years ago) by ph10
File size: 159537 byte(s)
Patch to reduce warnings from certain compilers.

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

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