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Revision 355 - (hide annotations) (download)
Mon Jul 7 17:45:23 2008 UTC (5 years, 9 months ago) by ph10
File size: 157365 byte(s)
Make pcretest generate a single byte for \x{} escapes in non-UTF-8 mode.

1 nigel 3 ChangeLog for PCRE
2     ------------------
3    
4 ph10 349 Version 8.0 02 Jul-08
5     ---------------------
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 353
17     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     or the function might crash, depending on the pattern.
20 ph10 354
21     4. Caseless matching was not working for non-ASCII characters in back
22     references. For example, /(\x{de})\1/8i was not matching \x{de}\x{fe}.
23     It now works when Unicode Property Support is available.
24 ph10 355
25     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     truncation.
29 ph10 349
30 ph10 351
31 ph10 347 Version 7.7 07-May-08
32 ph10 321 ---------------------
33    
34     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
35 ph10 345 a string to a long long, pretend we don't even have a long long." This is
36 ph10 321 done by checking for the strtoq, strtoll, and _strtoi64 functions.
37 ph10 345
38 ph10 322 2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
39     pre-7.6 versions, which defined a global no_arg variable instead of putting
40 ph10 332 it in the RE class. (See also #8 below.)
41 ph10 345
42     3. Remove a line of dead code, identified by coverity and reported by Nuno
43     Lopes.
44    
45 ph10 324 4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
46 ph10 321
47 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
48 ph10 345 of files, instead of just to the final components.
49    
50 ph10 324 (2) If there was more than one level of directory, the subdirectories were
51     skipped unless they satisfied the include/exclude conditions. This is
52     inconsistent with GNU grep (and could even be seen as contrary to the
53     pcregrep specification - which I improved to make it absolutely clear).
54     The action now is always to scan all levels of directory, and just
55     apply the include/exclude patterns to regular files.
56 ph10 345
57 ph10 325 5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
58 ph10 345 --exclude_dir in the tests to avoid scanning .svn directories.
59    
60 ph10 326 6. Applied Craig's patch to the QuoteMeta function so that it escapes the
61 ph10 345 NUL character as backslash + 0 rather than backslash + NUL, because PCRE
62 ph10 326 doesn't support NULs in patterns.
63 ph10 345
64     7. Added some missing "const"s to declarations of static tables in
65     pcre_compile.c and pcre_dfa_exec.c.
66    
67 ph10 328 8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
68 ph10 329 caused by fix #2 above. (Subsequently also a second patch to fix the
69 ph10 345 first patch. And a third patch - this was a messy problem.)
70 ph10 321
71 ph10 345 9. Applied Craig's patch to remove the use of push_back().
72    
73 ph10 332 10. Applied Alan Lehotsky's patch to add REG_STARTEND support to the POSIX
74     matching function regexec().
75 ph10 345
76     11. Added support for the Oniguruma syntax \g<name>, \g<n>, \g'name', \g'n',
77     which, however, unlike Perl's \g{...}, are subroutine calls, not back
78 ph10 333 references. PCRE supports relative numbers with this syntax (I don't think
79     Oniguruma does).
80 ph10 345
81     12. Previously, a group with a zero repeat such as (...){0} was completely
82 ph10 335 omitted from the compiled regex. However, this means that if the group
83     was called as a subroutine from elsewhere in the pattern, things went wrong
84 ph10 345 (an internal error was given). Such groups are now left in the compiled
85     pattern, with a new opcode that causes them to be skipped at execution
86 ph10 335 time.
87 ph10 345
88 ph10 341 13. Added the PCRE_JAVASCRIPT_COMPAT option. This makes the following changes
89     to the way PCRE behaves:
90 ph10 345
91 ph10 336 (a) A lone ] character is dis-allowed (Perl treats it as data).
92 ph10 345
93     (b) A back reference to an unmatched subpattern matches an empty string
94 ph10 336 (Perl fails the current match path).
95 ph10 345
96 ph10 341 (c) A data ] in a character class must be notated as \] because if the
97 ph10 345 first data character in a class is ], it defines an empty class. (In
98 ph10 341 Perl it is not possible to have an empty class.) The empty class []
99     never matches; it forces failure and is equivalent to (*FAIL) or (?!).
100     The negative empty class [^] matches any one character, independently
101     of the DOTALL setting.
102 ph10 345
103     14. A pattern such as /(?2)[]a()b](abc)/ which had a forward reference to a
104 ph10 340 non-existent subpattern following a character class starting with ']' and
105     containing () gave an internal compiling error instead of "reference to
106     non-existent subpattern". Fortunately, when the pattern did exist, the
107 ph10 345 compiled code was correct. (When scanning forwards to check for the
108 ph10 340 existencd of the subpattern, it was treating the data ']' as terminating
109 ph10 345 the class, so got the count wrong. When actually compiling, the reference
110 ph10 340 was subsequently set up correctly.)
111 ph10 345
112 ph10 341 15. The "always fail" assertion (?!) is optimzed to (*FAIL) by pcre_compile;
113 ph10 345 it was being rejected as not supported by pcre_dfa_exec(), even though
114     other assertions are supported. I have made pcre_dfa_exec() support
115     (*FAIL).
116    
117 ph10 342 16. The implementation of 13c above involved the invention of a new opcode,
118 ph10 345 OP_ALLANY, which is like OP_ANY but doesn't check the /s flag. Since /s
119     cannot be changed at match time, I realized I could make a small
120     improvement to matching performance by compiling OP_ALLANY instead of
121     OP_ANY for "." when DOTALL was set, and then removing the runtime tests
122     on the OP_ANY path.
123    
124     17. Compiling pcretest on Windows with readline support failed without the
125 ph10 343 following two fixes: (1) Make the unistd.h include conditional on
126 ph10 345 HAVE_UNISTD_H; (2) #define isatty and fileno as _isatty and _fileno.
127    
128 ph10 344 18. Changed CMakeLists.txt and cmake/FindReadline.cmake to arrange for the
129 ph10 345 ncurses library to be included for pcretest when ReadLine support is
130     requested, but also to allow for it to be overridden. This patch came from
131     Daniel Bergström.
132 ph10 347
133 ph10 346 19. There was a typo in the file ucpinternal.h where f0_rangeflag was defined
134 ph10 347 as 0x00f00000 instead of 0x00800000. Luckily, this would not have caused
135     any errors with the current Unicode tables. Thanks to Peter Kankowski for
136     spotting this.
137 ph10 324
138 ph10 332
139 ph10 319 Version 7.6 28-Jan-08
140 ph10 300 ---------------------
141    
142 ph10 302 1. A character class containing a very large number of characters with
143     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
144     overflow.
145 ph10 309
146     2. Patch to cut out the "long long" test in pcrecpp_unittest when
147     HAVE_LONG_LONG is not defined.
148    
149 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
150 ph10 304 bring them up to date and include new features. This patch includes:
151 ph10 309
152 ph10 304 - Fixed PH's badly added libz and libbz2 support.
153     - Fixed a problem with static linking.
154 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
155 ph10 304 - Fixed dftables problem and added an option.
156     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
157     HAVE_LONG_LONG.
158     - Added readline support for pcretest.
159 ph10 309 - Added an listing of the option settings after cmake has run.
160    
161 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
162     "pcre.dll" under mingw when using Configure/Make. I added stuff to
163     Makefile.am that cause it to include this special target, without
164     affecting anything else. Note that the same mingw target plus all
165     the other distribution libraries and programs are now supported
166     when configuring with CMake (see 6 below) instead of with
167     Configure/Make.
168 ph10 309
169 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
170     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
171 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
172     solves the problem, but it does no harm.
173 ph10 313
174 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
175 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
176 ph10 314 with CMake, and also correct the comment about stack recursion.
177 ph10 313
178 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
179 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
180     of a program that users should build themselves after PCRE is installed, so
181     building it automatically is not really right. What is more, it gave
182 ph10 312 trouble in some build environments.
183 ph10 300
184 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
185 ph10 308
186 ph10 319
187 ph10 298 Version 7.5 10-Jan-08
188 ph10 263 ---------------------
189    
190     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
191     values in parens when parsing an RE using the C++ wrapper."
192 ph10 286
193 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
194     Characters greater than 255 were excluded from the class instead of being
195     included.
196 ph10 286
197     3. The same bug as (2) above applied to negated POSIX classes such as
198 ph10 265 [:^space:].
199 ph10 286
200 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
201     defined or documented. It seems to have been a typo for PCRE_STATIC, so
202 ph10 286 I have changed it.
203    
204 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
205 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
206     first named subpattern whose name started with "a" (in other words, the
207 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
208     expected" is now given for (?&) (a zero-length name), and this patch also
209     makes it give the same error for \k'' (previously it complained that that
210     was a reference to a non-existent subpattern).
211 ph10 286
212 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
213 ph10 286 this is right because (?- can be followed by option settings as well as by
214 ph10 269 digits. I have, however, made the messages clearer.
215 ph10 286
216 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
217     than the number used in the conditional) now cause a compile-time error.
218     This is actually not compatible with Perl, which accepts such patterns, but
219     treats the conditional as always being FALSE (as PCRE used to), but it
220     seems to me that giving a diagnostic is better.
221 ph10 286
222 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
223 ph10 275 and messages.
224 ph10 286
225     9. Fix two occurrences of "backslash" in comments that should have been
226     "backspace".
227    
228     10. Remove two redundant lines of code that can never be obeyed (their function
229     was moved elsewhere).
230    
231     11. The program that makes PCRE's Unicode character property table had a bug
232     which caused it to generate incorrect table entries for sequences of
233 ph10 277 characters that have the same character type, but are in different scripts.
234 ph10 286 It amalgamated them into a single range, with the script of the first of
235 ph10 277 them. In other words, some characters were in the wrong script. There were
236     thirteen such cases, affecting characters in the following ranges:
237 ph10 286
238 ph10 277 U+002b0 - U+002c1
239     U+0060c - U+0060d
240 ph10 286 U+0061e - U+00612
241 ph10 277 U+0064b - U+0065e
242     U+0074d - U+0076d
243     U+01800 - U+01805
244     U+01d00 - U+01d77
245     U+01d9b - U+01dbf
246     U+0200b - U+0200f
247     U+030fc - U+030fe
248     U+03260 - U+0327f
249     U+0fb46 - U+0fbb1
250     U+10450 - U+1049d
251 ph10 286
252 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
253     compatible with GNU grep in that, if there was more than one match in a
254     line, it showed only the first of them. It now behaves in the same way as
255     GNU grep.
256 ph10 286
257     13. If the -o and -v options were combined for pcregrep, it printed a blank
258     line for every non-matching line. GNU grep prints nothing, and pcregrep now
259     does the same. The return code can be used to tell if there were any
260     non-matching lines.
261    
262 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
263    
264     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
265 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
266 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
267     and both kinds of lookbehind were skipped).
268    
269 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
270 ph10 284 inclusion of <windows.h> to before rather than after the definition of
271     INVALID_FILE_ATTRIBUTES (patch from David Byron).
272 ph10 263
273 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
274 ph10 286 character property caused pcre_compile() to compile bad code, which led at
275     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
276     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
277     caused the error; without that there was no problem.
278 ph10 263
279 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
280 ph10 286
281 ph10 289 19. Added --enable-pcretest-libreadline.
282 ph10 286
283 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
284 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
285 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
286     later patch that removed the other one (the right fix) and added unit tests
287     that check the return values (which was not done before).
288 ph10 292
289 ph10 291 21. Several CMake things:
290 ph10 287
291 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
292 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
293 ph10 288
294 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
295     linked with the newly-built libraries, not previously installed ones.
296 ph10 291
297 ph10 292 (3) Added PCRE_SUPPORT_LIBREADLINE, PCRE_SUPPORT_LIBZ, PCRE_SUPPORT_LIBBZ2.
298 ph10 298
299     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
300     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
301     UTF-8 newline character). The key issue is that the pattern starts .*;
302     this means that the match must be either at the beginning, or after a
303     newline. The bug was in the code for advancing after a failed match and
304     checking that the new position followed a newline. It was not taking
305 ph10 294 account of UTF-8 characters correctly.
306 ph10 298
307     23. PCRE was behaving differently from Perl in the way it recognized POSIX
308     character classes. PCRE was not treating the sequence [:...:] as a
309     character class unless the ... were all letters. Perl, however, seems to
310     allow any characters between [: and :], though of course it rejects as
311     unknown any "names" that contain non-letters, because all the known class
312     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
313     for example, whereas PCRE did not - it did not recognize a POSIX character
314     class. This seemed a bit dangerous, so the code has been changed to be
315     closer to Perl. The behaviour is not identical to Perl, because PCRE will
316     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
317     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
318     Perl does, and where it didn't before.
319    
320 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
321     Windows environments %n is disabled by default.
322 ph10 292
323    
324 ph10 260 Version 7.4 21-Sep-07
325 ph10 230 ---------------------
326    
327     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
328 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
329     LF". That isn't really right - the whole point of the change was to try to
330     help when there was an actual mention of one of the two characters. So now
331     the change happens only if \r or \n (or a literal CR or LF) character is
332 ph10 230 encountered.
333 ph10 231
334     2. The 32-bit options word was also used for 6 internal flags, but the numbers
335     of both had grown to the point where there were only 3 bits left.
336     Fortunately, there was spare space in the data structure, and so I have
337     moved the internal flags into a new 16-bit field to free up more option
338 ph10 230 bits.
339 ph10 231
340     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
341     but did not set the internal JCHANGED flag - either of these is enough to
342     control the way the "get" function works - but the PCRE_INFO_JCHANGED
343     facility is supposed to tell if (?J) was ever used, so now (?J) at the
344 ph10 230 start sets both bits.
345    
346 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
347     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
348 ph10 230
349 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
350    
351     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
352 ph10 233 compatibility, even though it is no longer used.
353 ph10 243
354     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
355 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
356 ph10 259 windows.h file is present (where different names are used). [This was
357 ph10 257 reversed later after testing - see 16 below.]
358 ph10 243
359     8. Changed all #include <config.h> to #include "config.h". There were also
360 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
361 ph10 243
362 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
363 ph10 243 sequence off the lines that it output.
364    
365     10. It was pointed out to me that arrays of string pointers cause lots of
366     relocations when a shared library is dynamically loaded. A technique of
367     using a single long string with a table of offsets can drastically reduce
368     these. I have refactored PCRE in four places to do this. The result is
369 ph10 240 dramatic:
370 ph10 243
371 ph10 240 Originally: 290
372     After changing UCP table: 187
373 ph10 243 After changing error message table: 43
374 ph10 240 After changing table of "verbs" 36
375     After changing table of Posix names 22
376 ph10 243
377 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
378 ph10 247
379 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
380 ph10 247 unicode-properties was also set.
381    
382 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
383 ph10 231
384 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
385     checked only for CRLF.
386 ph10 233
387 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
388    
389 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
390 ph10 253
391 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
392 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
393     entirely. This removes changes made in 7 above.
394 ph10 256
395 ph10 261 17. The CMake files have been updated, and there is now more information about
396     building with CMake in the NON-UNIX-USE document.
397 ph10 257
398 ph10 261
399 ph10 228 Version 7.3 28-Aug-07
400 ph10 157 ---------------------
401    
402 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
403     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
404     brackets there is not right, since it causes compilers to look for an
405     installed pcre.h, not the version that is in the source that is being
406     compiled (which of course may be different). I have changed it back to:
407 ph10 197
408 ph10 189 #include "pcre.h"
409 ph10 197
410     I have a vague recollection that the change was concerned with compiling in
411     different directories, but in the new build system, that is taken care of
412     by the VPATH setting the Makefile.
413    
414 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
415     when the subject happened to end in the byte 0x85 (e.g. if the last
416     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
417     characters but of course it shouldn't be taken as a newline when it is part
418     of another character. The bug was that, for an unlimited repeat of . in
419     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
420     characters when looking for a newline.
421 ph10 197
422     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
423    
424     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
425     in debug output.
426    
427 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
428     long printing in the pcrecpp unittest when running under MinGW.
429 ph10 189
430 ph10 197 6. ESC_K was left out of the EBCDIC table.
431 ph10 189
432 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
433     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
434     limit also applies to "virtual nesting" when a pattern is recursive, and in
435     this case 1000 isn't so big. I have been able to remove this limit at the
436     expense of backing off one optimization in certain circumstances. Normally,
437     when pcre_exec() would call its internal match() function recursively and
438     immediately return the result unconditionally, it uses a "tail recursion"
439     feature to save stack. However, when a subpattern that can match an empty
440     string has an unlimited repetition quantifier, it no longer makes this
441     optimization. That gives it a stack frame in which to save the data for
442     checking that an empty string has been matched. Previously this was taken
443     from the 1000-entry workspace that had been reserved. So now there is no
444     explicit limit, but more stack is used.
445 ph10 189
446 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
447     syntax that is required for Windows, and which was going wrong for the
448     pcreposix and pcrecpp parts of the library. These were overlooked when this
449     problem was solved for the main library.
450 ph10 197
451 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
452     the size of patterns that contain repeated groups with explicit upper
453     limits. As the maximum quantifier is 65535, the maximum group length was
454     set at 30,000 so that the product of these two numbers did not overflow a
455     32-bit integer. However, it turns out that people want to use groups that
456     are longer than 30,000 bytes (though not repeat them that many times).
457     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
458     made it possible to implement the integer overflow checks in a much more
459     dynamic way, which I have now done. The artificial limitation on group
460     length has been removed - we now have only the limit on the total length of
461     the compiled pattern, which depends on the LINK_SIZE setting.
462 ph10 208
463     10. Fixed a bug in the documentation for get/copy named substring when
464     duplicate names are permitted. If none of the named substrings are set, the
465     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
466     empty string.
467    
468     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
469     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
470     because the ] is interpreted as the first data character and the
471     terminating ] is not found. PCRE has been made compatible with Perl in this
472     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
473     cause memory overwriting.
474    
475 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
476     string has been matched (to stop an infinite loop). It was not recognizing
477 ph10 208 a conditional subpattern that could match an empty string if that
478 ph10 206 subpattern was within another subpattern. For example, it looped when
479 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
480 ph10 206 condition was not nested. This bug has been fixed.
481 ph10 208
482 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
483     past the start of the subject in the presence of bytes with the top bit
484     set, for example "\x8aBCD".
485 ph10 211
486 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
487     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
488 ph10 200
489 ph10 211 14. Optimized (?!) to (*FAIL).
490 ph10 202
491 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
492     This restricts code points to be within the range 0 to 0x10FFFF, excluding
493     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
494     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
495     does: it's just the validity check that is more restrictive.
496 ph10 220
497     16. Inserted checks for integer overflows during escape sequence (backslash)
498     processing, and also fixed erroneous offset values for syntax errors during
499     backslash processing.
500    
501 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
502 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
503    
504 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
505     caused an overrun.
506 ph10 220
507     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
508     something other than just ASCII characters) inside a group that had an
509     unlimited repeat caused a loop at compile time (while checking to see
510     whether the group could match an empty string).
511    
512 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
513     [\P{Any}] did so. (Error in the code for printing property names.)
514 ph10 210
515 ph10 220 21. An orphan \E inside a character class could cause a crash.
516    
517     22. A repeated capturing bracket such as (A)? could cause a wild memory
518 ph10 218 reference during compilation.
519 ph10 220
520     23. There are several functions in pcre_compile() that scan along a compiled
521     expression for various reasons (e.g. to see if it's fixed length for look
522 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
523 ph10 220 present in the pattern. These operators have additional parameters compared
524     with \d, etc, and these were not being taken into account when moving along
525 ph10 218 the compiled data. Specifically:
526 ph10 220
527     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
528     length.
529    
530     (b) An item such as \pL+ within a repeated group could cause crashes or
531 ph10 218 loops.
532 ph10 220
533 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
534 ph10 220 "reference to non-existent subpattern" error.
535    
536 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
537    
538 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
539 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
540 ph10 211
541 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
542 ph10 218
543 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
544 ph10 223 character were causing crashes (broken optimization).
545 ph10 227
546 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
547 ph10 227 \p or \P) caused a compile-time loop.
548    
549 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
550     break. For example, the unstudied pattern [\r\n]A does not match the string
551     "\r\nA" because change 7.0/46 below moves the current point on by two
552     characters after failing to match at the start. However, the pattern \nA
553 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
554     the same is true. There doesn't seem any very clean way out of this, but
555     what I have chosen to do makes the common cases work: PCRE now takes note
556     of whether there can be an explicit match for \r or \n anywhere in the
557     pattern, and if so, 7.0/46 no longer applies. As part of this change,
558     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
559     pattern has explicit CR or LF references.
560 ph10 222
561 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
562 ph10 223
563 ph10 227
564 ph10 189 Version 7.2 19-Jun-07
565     ---------------------
566    
567 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
568     which is apparently normally available under Windows.
569 ph10 159
570     2. Re-jig the pcregrep tests with different newline settings in an attempt
571     to make them independent of the local environment's newline setting.
572 ph10 157
573 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
574 ph10 165
575 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
576     was not 2, because the output contained actual offsets. The recent new
577 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
578     usable with all link sizes.
579    
580 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
581     stack recursion. This gives a massive performance boost under BSD, but just
582 ph10 165 a small improvement under Linux. However, it saves one field in the frame
583 ph10 164 in all cases.
584 ph10 172
585 ph10 166 6. Added more features from the forthcoming Perl 5.10:
586 ph10 172
587 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
588     recursion call. It refers to the nth most recently opened parentheses.
589 ph10 172
590 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
591 ph10 172 to be opened parentheses.
592    
593     (c) Conditions that refer to capturing parentheses can be specified
594 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
595 ph10 172
596 ph10 168 (d) \K resets the start of the current match so that everything before
597 ph10 172 is not part of it.
598    
599 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
600 ph10 172
601 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
602 ph10 172 reference syntax.
603 ph10 182
604 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
605 ph10 182 alternative starts with the same number.
606 ph10 172
607 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
608    
609 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
610     PCRE_INFO_JCHANGED.
611    
612     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
613     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
614 ph10 170 for detecting groups that can match an empty string.
615 ph10 159
616 ph10 172 9. A pattern with a very large number of alternatives (more than several
617     hundred) was running out of internal workspace during the pre-compile
618     phase, where pcre_compile() figures out how much memory will be needed. A
619     bit of new cunning has reduced the workspace needed for groups with
620     alternatives. The 1000-alternative test pattern now uses 12 bytes of
621     workspace instead of running out of the 4096 that are available.
622 ph10 182
623 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
624 ph10 172
625 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
626     The report of the bug said:
627 ph10 182
628 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
629     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
630 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
631 ph10 185
632 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
633 ph10 185 it matched the wrong number of bytes.
634 ph10 172
635 ph10 179
636 ph10 155 Version 7.1 24-Apr-07
637 ph10 98 ---------------------
638    
639 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
640 ph10 122 that is more "standard", making use of automake and other Autotools. There
641 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
642     on this.
643 ph10 111
644     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
645     for recursive directory scanning broke on some systems because the files
646     are not scanned in any specific order and on different systems the order
647     was different. A call to "sort" has been inserted into RunGrepTest for the
648     approprate test as a short-term fix. In the longer term there may be an
649 ph10 100 alternative.
650 ph10 111
651 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
652 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
653     people do their own conversions for various reasons). The problems
654     concerned the use of low-level troff macros .br and .in. I have therefore
655     removed all such uses from the man pages (some were redundant, some could
656 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
657     HTML has been updated to handle .nf/.fi and to complain if it encounters
658     .br or .in.
659 ph10 111
660 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
661 ph10 123 arranged for config.h to be included in the distribution, with the name
662 ph10 111 config.h.generic, for the benefit of those who have to compile without
663     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
664    
665     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
666     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
667 ph10 127 makevp.bat for the current PCRE, using the additional files
668 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
669 ph10 111
670     6. A Windows user reported a minor discrepancy with test 2, which turned out
671     to be caused by a trailing space on an input line that had got lost in his
672 ph10 102 copy. The trailing space was an accident, so I've just removed it.
673 ph10 111
674 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
675 ph10 111 that is needed.
676    
677 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
678     as "const" (a) because they are and (b) because it helps the PHP
679     maintainers who have recently made a script to detect big data structures
680 ph10 111 in the php code that should be moved to the .rodata section. I remembered
681     to update Builducptable as well, so it won't revert if ucptable.h is ever
682 ph10 105 re-created.
683 ph10 111
684     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
685 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
686 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
687     support is not required. This saves 1.5-2K of code, which is important in
688 ph10 107 some applications.
689 ph10 111
690 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
691 ph10 111 so as not to refer to the tables, even though these functions will never be
692     called when UTF-8 support is disabled. Otherwise there are problems with a
693     shared library.
694    
695 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
696    
697     (a) It was defining its arguments as char * instead of void *.
698    
699 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
700     a long time ago when I wrote it, but is no longer the case.
701    
702 ph10 118 The emulated memove() is provided for those environments that have neither
703 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
704 ph10 118 is clearly not the case, as these two bugs were recently reported.
705 ph10 123
706 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
707 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
708     pages, and it removes trailing spaces from listed files. It also creates
709     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
710     case, it wraps all the #defines with #ifndefs. This script should be run
711 ph10 111 before "make dist".
712 ph10 123
713 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
714     with Unicode property support.
715 ph10 123
716     (a) For a maximizing quantifier, if the two different cases of the
717     character were of different lengths in their UTF-8 codings (there are
718     some cases like this - I found 11), and the matching function had to
719 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
720     were both the same length.
721 ph10 123
722     (b) When PCRE was configured to use the heap rather than the stack for
723     recursion during matching, it was not correctly preserving the data for
724     the other case of a UTF-8 character when checking ahead for a match
725     while processing a minimizing repeat. If the check also involved
726 ph10 115 matching a wide character, but failed, corruption could cause an
727     erroneous result when trying to check for a repeat of the original
728     character.
729 ph10 123
730 ph10 116 13. Some tidying changes to the testing mechanism:
731 ph10 98
732 ph10 116 (a) The RunTest script now detects the internal link size and whether there
733     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
734 ph10 123 values substituted by "configure". (The RunGrepTest script already did
735     this for UTF-8.) The configure.ac script no longer substitutes the
736     relevant variables.
737    
738 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
739     with length and offset values. This means that the output is different
740     for different internal link sizes. Test 2 is skipped for link sizes
741     other than 2 because of this, bypassing the problem. Unfortunately,
742     there was also a test in test 3 (the locale tests) that used /B and
743 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
744     I have added a new /Z option to pcretest that replaces the length and
745     offset values with spaces. This is now used to make test 3 independent
746 ph10 122 of link size. (Test 2 will be tidied up later.)
747 ph10 123
748     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
749 ph10 122 segmentation fault instead of returning the appropriate error message.
750 ph10 134
751 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
752 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
753     This doesn't seem right; it now treats the CRLF combination as the line
754     ending, and so does not match in that case. It's only a pattern such as ^$
755     that would hit this one: something like ^ABC$ would have failed after \r
756     and then tried again after \r\n.
757    
758 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
759 ph10 134 in an attempt to make files that differ only in their line terminators
760     compare equal. This works on Linux.
761 ph10 142
762 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
763     as it exited. This is now fixed, thanks to valgrind.
764 ph10 142
765 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
766 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
767     was because its rules for how to advance for /g after matching an empty
768 ph10 143 string at the end of a line did not allow for this case. They now check for
769     it specially.
770 ph10 150
771     20. pcretest is supposed to handle patterns and data of any length, by
772     extending its buffers when necessary. It was getting this wrong when the
773 ph10 147 buffer for a data line had to be extended.
774 ph10 150
775 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
776 ph10 150 CRLF as a newline sequence.
777 ph10 152
778 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
779 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
780     I have nevertheless tidied it up.
781 ph10 111
782 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
783 ph10 123
784 ph10 153 24. Added a man page for pcre-config.
785 ph10 152
786 ph10 153
787 nigel 93 Version 7.0 19-Dec-06
788     ---------------------
789    
790     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
791     moving to gcc 4.1.1.
792    
793     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
794     sys/time.h, which is documented as needed for this function. It doesn't
795     seem to matter on Linux, but it showed up on some releases of OS X.
796    
797     3. It seems that there are systems where bytes whose values are greater than
798     127 match isprint() in the "C" locale. The "C" locale should be the
799     default when a C program starts up. In most systems, only ASCII printing
800     characters match isprint(). This difference caused the output from pcretest
801     to vary, making some of the tests fail. I have changed pcretest so that:
802    
803     (a) When it is outputting text in the compiled version of a pattern, bytes
804     other than 32-126 are always shown as hex escapes.
805    
806     (b) When it is outputting text that is a matched part of a subject string,
807     it does the same, unless a different locale has been set for the match
808     (using the /L modifier). In this case, it uses isprint() to decide.
809    
810     4. Fixed a major bug that caused incorrect computation of the amount of memory
811     required for a compiled pattern when options that changed within the
812     pattern affected the logic of the preliminary scan that determines the
813     length. The relevant options are -x, and -i in UTF-8 mode. The result was
814     that the computed length was too small. The symptoms of this bug were
815     either the PCRE error "internal error: code overflow" from pcre_compile(),
816     or a glibc crash with a message such as "pcretest: free(): invalid next
817     size (fast)". Examples of patterns that provoked this bug (shown in
818     pcretest format) are:
819    
820     /(?-x: )/x
821     /(?x)(?-x: \s*#\s*)/
822     /((?i)[\x{c0}])/8
823     /(?i:[\x{c0}])/8
824    
825     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
826     is now done differently.
827    
828     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
829     wrapper classes; (b) implement a new function in the C++ scanner that is
830     more efficient than the old way of doing things because it avoids levels of
831     recursion in the regex matching; (c) add a paragraph to the documentation
832     for the FullMatch() function.
833    
834     6. The escape sequence \n was being treated as whatever was defined as
835     "newline". Not only was this contrary to the documentation, which states
836     that \n is character 10 (hex 0A), but it also went horribly wrong when
837     "newline" was defined as CRLF. This has been fixed.
838    
839     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
840     was being set to -1 for the "end of line" case (supposedly a value that no
841     character can have). Though this value is never used (the check for end of
842     line is "zero bytes in current character"), it caused compiler complaints.
843     I've changed it to 0xffffffff.
844    
845     8. In pcre_version.c, the version string was being built by a sequence of
846     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
847     string (as it is for production releases) called a macro with an empty
848     argument. The C standard says the result of this is undefined. The gcc
849     compiler treats it as an empty string (which was what was wanted) but it is
850     reported that Visual C gives an error. The source has been hacked around to
851     avoid this problem.
852    
853     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
854     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
855     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
856     of them did).
857    
858     10. Originally, pcretest opened its input and output without "b"; then I was
859     told that "b" was needed in some environments, so it was added for release
860     5.0 to both the input and output. (It makes no difference on Unix-like
861     systems.) Later I was told that it is wrong for the input on Windows. I've
862     now abstracted the modes into two macros, to make it easier to fiddle with
863     them, and removed "b" from the input mode under Windows.
864    
865     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
866    
867     12. Added -help and --help to pcretest as an official way of being reminded
868     of the options.
869    
870     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
871     and pcrecpp.cc because they annoy compilers at high warning levels.
872    
873     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
874    
875     15. Fixed an occurrence of == in configure.ac that should have been = (shell
876     scripts are not C programs :-) and which was not noticed because it works
877     on Linux.
878    
879     16. pcretest is supposed to handle any length of pattern and data line (as one
880     line or as a continued sequence of lines) by extending its input buffer if
881     necessary. This feature was broken for very long pattern lines, leading to
882     a string of junk being passed to pcre_compile() if the pattern was longer
883     than about 50K.
884    
885     17. I have done a major re-factoring of the way pcre_compile() computes the
886     amount of memory needed for a compiled pattern. Previously, there was code
887     that made a preliminary scan of the pattern in order to do this. That was
888     OK when PCRE was new, but as the facilities have expanded, it has become
889     harder and harder to keep it in step with the real compile phase, and there
890     have been a number of bugs (see for example, 4 above). I have now found a
891     cunning way of running the real compile function in a "fake" mode that
892     enables it to compute how much memory it would need, while actually only
893     ever using a few hundred bytes of working memory and without too many
894     tests of the mode. This should make future maintenance and development
895     easier. A side effect of this work is that the limit of 200 on the nesting
896     depth of parentheses has been removed (though this was never a serious
897     limitation, I suspect). However, there is a downside: pcre_compile() now
898     runs more slowly than before (30% or more, depending on the pattern). I
899     hope this isn't a big issue. There is no effect on runtime performance.
900    
901     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
902     newline (only possible for the last line of a file) and it was a
903     pattern that set a locale (followed by /Lsomething), pcretest crashed.
904    
905     19. Added additional timing features to pcretest. (1) The -tm option now times
906     matching only, not compiling. (2) Both -t and -tm can be followed, as a
907     separate command line item, by a number that specifies the number of
908     repeats to use when timing. The default is 50000; this gives better
909     precision, but takes uncomfortably long for very large patterns.
910    
911     20. Extended pcre_study() to be more clever in cases where a branch of a
912     subpattern has no definite first character. For example, (a*|b*)[cd] would
913     previously give no result from pcre_study(). Now it recognizes that the
914     first character must be a, b, c, or d.
915    
916     21. There was an incorrect error "recursive call could loop indefinitely" if
917     a subpattern (or the entire pattern) that was being tested for matching an
918     empty string contained only one non-empty item after a nested subpattern.
919     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
920     incorrectly, because the \d was being skipped in the check.
921    
922     22. The pcretest program now has a new pattern option /B and a command line
923     option -b, which is equivalent to adding /B to every pattern. This causes
924     it to show the compiled bytecode, without the additional information that
925     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
926     is the same as /B/I).
927    
928     23. A new optimization is now able automatically to treat some sequences such
929     as a*b as a*+b. More specifically, if something simple (such as a character
930     or a simple class like \d) has an unlimited quantifier, and is followed by
931     something that cannot possibly match the quantified thing, the quantifier
932     is automatically "possessified".
933    
934     24. A recursive reference to a subpattern whose number was greater than 39
935     went wrong under certain circumstances in UTF-8 mode. This bug could also
936     have affected the operation of pcre_study().
937    
938     25. Realized that a little bit of performance could be had by replacing
939     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
940    
941     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
942    
943     27. Possessive quantifiers such as a++ were previously implemented by turning
944     them into atomic groups such as ($>a+). Now they have their own opcodes,
945     which improves performance. This includes the automatically created ones
946     from 23 above.
947    
948     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
949     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
950     the first matched character to be a colon. This applied both to named and
951     numbered groups.
952    
953     29. The ucpinternal.h header file was missing its idempotency #ifdef.
954    
955     30. I was sent a "project" file called libpcre.a.dev which I understand makes
956     building PCRE on Windows easier, so I have included it in the distribution.
957    
958     31. There is now a check in pcretest against a ridiculously large number being
959     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
960     loop, the loop is abandoned.
961    
962     32. Forward references to subpatterns in conditions such as (?(2)...) where
963     subpattern 2 is defined later cause pcre_compile() to search forwards in
964     the pattern for the relevant set of parentheses. This search went wrong
965     when there were unescaped parentheses in a character class, parentheses
966     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
967    
968     33. "Subroutine" calls and backreferences were previously restricted to
969     referencing subpatterns earlier in the regex. This restriction has now
970     been removed.
971    
972     34. Added a number of extra features that are going to be in Perl 5.10. On the
973     whole, these are just syntactic alternatives for features that PCRE had
974     previously implemented using the Python syntax or my own invention. The
975     other formats are all retained for compatibility.
976    
977     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
978     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
979     also .NET compatible.
980    
981     (b) A recursion or subroutine call to a named group can now be defined as
982     (?&name) as well as (?P>name).
983    
984     (c) A backreference to a named group can now be defined as \k<name> or
985     \k'name' as well as (?P=name). The new forms, as well as being in Perl
986     5.10, are also .NET compatible.
987    
988     (d) A conditional reference to a named group can now use the syntax
989     (?(<name>) or (?('name') as well as (?(name).
990    
991     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
992     groups (named and numbered) that are never evaluated inline, but can be
993     called as "subroutines" from elsewhere. In effect, the DEFINE condition
994     is always false. There may be only one alternative in such a group.
995    
996     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
997     as the simple (?(R). The condition is true only if the most recent
998     recursion is that of the given number or name. It does not search out
999     through the entire recursion stack.
1000    
1001     (g) The escape \gN or \g{N} has been added, where N is a positive or
1002     negative number, specifying an absolute or relative reference.
1003    
1004     35. Tidied to get rid of some further signed/unsigned compiler warnings and
1005     some "unreachable code" warnings.
1006    
1007     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
1008     things, this adds five new scripts.
1009    
1010     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
1011     There were also incompatibilities regarding the handling of \Q..\E inside
1012     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
1013     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
1014    
1015     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
1016     matches an empty string, and forcibly breaks the loop. There were bugs in
1017     this code in non-simple cases. For a pattern such as ^(a()*)* matched
1018     against aaaa the result was just "a" rather than "aaaa", for example. Two
1019     separate and independent bugs (that affected different cases) have been
1020     fixed.
1021    
1022     39. Refactored the code to abolish the use of different opcodes for small
1023     capturing bracket numbers. This is a tidy that I avoided doing when I
1024     removed the limit on the number of capturing brackets for 3.5 back in 2001.
1025     The new approach is not only tidier, it makes it possible to reduce the
1026     memory needed to fix the previous bug (38).
1027    
1028     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
1029     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
1030     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
1031     mode.
1032    
1033     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
1034     report.
1035    
1036     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
1037     copy construction and assignment in the C++ wrapper.
1038    
1039     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
1040     couple of bugs that could have given wrong results in the "--newline=crlf"
1041     case.
1042    
1043     44. Added a number of casts and did some reorganization of signed/unsigned int
1044     variables following suggestions from Dair Grant. Also renamed the variable
1045     "this" as "item" because it is a C++ keyword.
1046    
1047     45. Arranged for dftables to add
1048    
1049     #include "pcre_internal.h"
1050    
1051     to pcre_chartables.c because without it, gcc 4.x may remove the array
1052     definition from the final binary if PCRE is built into a static library and
1053     dead code stripping is activated.
1054    
1055     46. For an unanchored pattern, if a match attempt fails at the start of a
1056     newline sequence, and the newline setting is CRLF or ANY, and the next two
1057     characters are CRLF, advance by two characters instead of one.
1058    
1059    
1060 nigel 91 Version 6.7 04-Jul-06
1061     ---------------------
1062    
1063     1. In order to handle tests when input lines are enormously long, pcretest has
1064     been re-factored so that it automatically extends its buffers when
1065     necessary. The code is crude, but this _is_ just a test program. The
1066     default size has been increased from 32K to 50K.
1067    
1068     2. The code in pcre_study() was using the value of the re argument before
1069     testing it for NULL. (Of course, in any sensible call of the function, it
1070     won't be NULL.)
1071    
1072     3. The memmove() emulation function in pcre_internal.h, which is used on
1073     systems that lack both memmove() and bcopy() - that is, hardly ever -
1074     was missing a "static" storage class specifier.
1075    
1076     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
1077     containing an extended class (one that cannot be represented by a bitmap
1078     because it contains high-valued characters or Unicode property items, e.g.
1079     [\pZ]). Almost always one would set UTF-8 mode when processing such a
1080     pattern, but PCRE should not loop if you do not (it no longer does).
1081     [Detail: two cases were found: (a) a repeated subpattern containing an
1082     extended class; (b) a recursive reference to a subpattern that followed a
1083     previous extended class. It wasn't skipping over the extended class
1084     correctly when UTF-8 mode was not set.]
1085    
1086     5. A negated single-character class was not being recognized as fixed-length
1087     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
1088     compile error "lookbehind assertion is not fixed length".
1089    
1090     6. The RunPerlTest auxiliary script was showing an unexpected difference
1091     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
1092     write a Perl script that can interpret lines of an input file either as
1093     byte characters or as UTF-8, which is what "perltest" was being required to
1094     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1095     can't do is switch easily at run time between having the "use utf8;" pragma
1096     or not. In the end, I fudged it by using the RunPerlTest script to insert
1097     "use utf8;" explicitly for the UTF-8 tests.
1098    
1099     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1100     the end of the subject string, contrary to the documentation and to what
1101     Perl does. This was true of both matching functions. Now it matches only at
1102     the start of the subject and immediately after *internal* newlines.
1103    
1104     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1105     a pointer to an int instead of a pointer to an unsigned long int. This
1106     caused problems on 64-bit systems.
1107    
1108     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1109     instance of the 'standard' template library not being so standard".
1110    
1111     10. There was no check on the number of named subpatterns nor the maximum
1112     length of a subpattern name. The product of these values is used to compute
1113     the size of the memory block for a compiled pattern. By supplying a very
1114     long subpattern name and a large number of named subpatterns, the size
1115     computation could be caused to overflow. This is now prevented by limiting
1116     the length of names to 32 characters, and the number of named subpatterns
1117     to 10,000.
1118    
1119     11. Subpatterns that are repeated with specific counts have to be replicated in
1120     the compiled pattern. The size of memory for this was computed from the
1121     length of the subpattern and the repeat count. The latter is limited to
1122     65535, but there was no limit on the former, meaning that integer overflow
1123     could in principle occur. The compiled length of a repeated subpattern is
1124     now limited to 30,000 bytes in order to prevent this.
1125    
1126     12. Added the optional facility to have named substrings with the same name.
1127    
1128     13. Added the ability to use a named substring as a condition, using the
1129     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1130     are numbers (not recommended). Forward references are permitted.
1131    
1132     14. Added forward references in named backreferences (if you see what I mean).
1133    
1134     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1135     pattern could run off the end of the subject. For example, the pattern
1136     "(?s)(.{1,5})"8 did this with the subject "ab".
1137    
1138     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1139     PCRE_CASELESS was set when matching characters that were quantified with ?
1140     or *.
1141    
1142     17. A character class other than a single negated character that had a minimum
1143     but no maximum quantifier - for example [ab]{6,} - was not handled
1144     correctly by pce_dfa_exec(). It would match only one character.
1145    
1146     18. A valid (though odd) pattern that looked like a POSIX character
1147     class but used an invalid character after [ (for example [[,abc,]]) caused
1148     pcre_compile() to give the error "Failed: internal error: code overflow" or
1149     in some cases to crash with a glibc free() error. This could even happen if
1150     the pattern terminated after [[ but there just happened to be a sequence of
1151     letters, a binary zero, and a closing ] in the memory that followed.
1152    
1153     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1154     over the years. Originally (before any Unicode support), just the bottom 8
1155     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1156     output from "man perlunicode" includes this:
1157    
1158     The regular expression compiler produces polymorphic opcodes. That
1159     is, the pattern adapts to the data and automatically switches to
1160     the Unicode character scheme when presented with Unicode data--or
1161     instead uses a traditional byte scheme when presented with byte
1162     data.
1163    
1164     Sadly, a wide octal escape does not cause a switch, and in a string with
1165     no other multibyte characters, these octal escapes are treated as before.
1166     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1167     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1168     Unicode string.
1169    
1170     I have not perpetrated such confusion in PCRE. Up till now, it took just
1171     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1172     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1173     translate to the appropriate multibyte character.
1174    
1175     29. Applied some refactoring to reduce the number of warnings from Microsoft
1176     and Borland compilers. This has included removing the fudge introduced
1177     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1178     a warning about an unused variable.
1179    
1180     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1181     characters since release 4.0, because Perl (from release 5.004) does not.
1182     [Or at least, is documented not to: some releases seem to be in conflict
1183     with the documentation.] However, when a pattern was studied with
1184     pcre_study() and all its branches started with \s, PCRE still included VT
1185     as a possible starting character. Of course, this did no harm; it just
1186     caused an unnecessary match attempt.
1187    
1188     22. Removed a now-redundant internal flag bit that recorded the fact that case
1189     dependency changed within the pattern. This was once needed for "required
1190     byte" processing, but is no longer used. This recovers a now-scarce options
1191     bit. Also moved the least significant internal flag bit to the most-
1192     significant bit of the word, which was not previously used (hangover from
1193     the days when it was an int rather than a uint) to free up another bit for
1194     the future.
1195    
1196     23. Added support for CRLF line endings as well as CR and LF. As well as the
1197     default being selectable at build time, it can now be changed at runtime
1198     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1199     specify that it is scanning data with non-default line endings.
1200    
1201     24. Changed the definition of CXXLINK to make it agree with the definition of
1202     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1203    
1204     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1205     recursions. This makes a big different to stack usage for some patterns.
1206    
1207     26. If a subpattern containing a named recursion or subroutine reference such
1208     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1209     the space required for the compiled pattern went wrong and gave too small a
1210     value. Depending on the environment, this could lead to "Failed: internal
1211     error: code overflow at offset 49" or "glibc detected double free or
1212     corruption" errors.
1213    
1214     27. Applied patches from Google (a) to support the new newline modes and (b) to
1215     advance over multibyte UTF-8 characters in GlobalReplace.
1216    
1217     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1218     difference for some implementation of PCRE in some Windows version.
1219    
1220     29. Added some extra testing facilities to pcretest:
1221    
1222     \q<number> in a data line sets the "match limit" value
1223     \Q<number> in a data line sets the "match recursion limt" value
1224     -S <number> sets the stack size, where <number> is in megabytes
1225    
1226     The -S option isn't available for Windows.
1227    
1228    
1229 nigel 89 Version 6.6 06-Feb-06
1230     ---------------------
1231    
1232     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1233     in pcreposix.h. I have copied the definition from pcre.h.
1234    
1235     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1236     because pcre.h is no longer a built file.
1237    
1238     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1239     not normally included in the compiled code.
1240    
1241    
1242 nigel 87 Version 6.5 01-Feb-06
1243     ---------------------
1244    
1245     1. When using the partial match feature with pcre_dfa_exec(), it was not
1246     anchoring the second and subsequent partial matches at the new starting
1247     point. This could lead to incorrect results. For example, with the pattern
1248     /1234/, partially matching against "123" and then "a4" gave a match.
1249    
1250     2. Changes to pcregrep:
1251    
1252     (a) All non-match returns from pcre_exec() were being treated as failures
1253     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1254     error message is output. Some extra information is given for the
1255     PCRE_ERROR_MATCHLIMIT and PCRE_ERROR_RECURSIONLIMIT errors, which are
1256     probably the only errors that are likely to be caused by users (by
1257     specifying a regex that has nested indefinite repeats, for instance).
1258     If there are more than 20 of these errors, pcregrep is abandoned.
1259    
1260     (b) A binary zero was treated as data while matching, but terminated the
1261     output line if it was written out. This has been fixed: binary zeroes
1262     are now no different to any other data bytes.
1263    
1264     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1265     used to set a locale for matching. The --locale=xxxx long option has
1266     been added (no short equivalent) to specify a locale explicitly on the
1267     pcregrep command, overriding the environment variables.
1268    
1269     (d) When -B was used with -n, some line numbers in the output were one less
1270     than they should have been.
1271    
1272     (e) Added the -o (--only-matching) option.
1273    
1274     (f) If -A or -C was used with -c (count only), some lines of context were
1275     accidentally printed for the final match.
1276    
1277     (g) Added the -H (--with-filename) option.
1278    
1279     (h) The combination of options -rh failed to suppress file names for files
1280     that were found from directory arguments.
1281    
1282     (i) Added the -D (--devices) and -d (--directories) options.
1283    
1284     (j) Added the -F (--fixed-strings) option.
1285    
1286     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1287    
1288     (l) Added the --colo(u)r option.
1289    
1290     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1291     is not present by default.
1292    
1293     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1294     items such as (?R) or (?1), when the recursion could match a number of
1295     alternatives. If it matched one of the alternatives, but subsequently,
1296     outside the recursion, there was a failure, the code tried to back up into
1297     the recursion. However, because of the way PCRE is implemented, this is not
1298     possible, and the result was an incorrect result from the match.
1299    
1300     In order to prevent this happening, the specification of recursion has
1301     been changed so that all such subpatterns are automatically treated as
1302     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1303    
1304     4. I had overlooked the fact that, in some locales, there are characters for
1305     which isalpha() is true but neither isupper() nor islower() are true. In
1306     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1307     and ordfeminine) are like this. This affected the treatment of \w and \W
1308     when they appeared in character classes, but not when they appeared outside
1309     a character class. The bit map for "word" characters is now created
1310     separately from the results of isalnum() instead of just taking it from the
1311     upper, lower, and digit maps. (Plus the underscore character, of course.)
1312    
1313     5. The above bug also affected the handling of POSIX character classes such as
1314     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1315     permanent tables. Instead, the bit maps for such a class were previously
1316     created as the appropriate unions of the upper, lower, and digit bitmaps.
1317     Now they are created by subtraction from the [[:word:]] class, which has
1318     its own bitmap.
1319    
1320     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1321     It is created by subtracting the vertical space characters (\x09, \x0a,
1322     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1323     subtraction was done in the overall bitmap for a character class, meaning
1324     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1325     be recognized. This bug has been fixed.
1326    
1327     7. Patches from the folks at Google:
1328    
1329     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1330     real life, but is still worth protecting against".
1331    
1332     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1333     regular expressions".
1334    
1335     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1336     have it.
1337    
1338     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1339     "configure" and the latter not, in order to fix a problem somebody had
1340     with compiling the Arg class on HP-UX.
1341    
1342     (e) Improve the error-handling of the C++ wrapper a little bit.
1343    
1344     (f) New tests for checking recursion limiting.
1345    
1346     8. The pcre_memmove() function, which is used only if the environment does not
1347     have a standard memmove() function (and is therefore rarely compiled),
1348     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1349     returning a result (though PCRE never actually uses the result).
1350    
1351     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1352     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1353     returned instead of calling malloc() with an overflowing number that would
1354     most likely cause subsequent chaos.
1355    
1356     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1357    
1358     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1359     with this option is matched, the nmatch and pmatch options of regexec() are
1360     ignored.
1361    
1362     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1363     provided in case anyone wants to the the POSIX interface with UTF-8
1364     strings.
1365    
1366     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1367     C++ linking (needed for some HP-UX environments).
1368    
1369     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1370     (unused parameter) and in the pcre_printint() function (omitted "default"
1371     switch label when the default is to do nothing).
1372    
1373     15. Added some code to make it possible, when PCRE is compiled as a C++
1374     library, to replace subject pointers for pcre_exec() with a smart pointer
1375     class, thus making it possible to process discontinuous strings.
1376    
1377     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1378     much the same function. They were added by different people who were trying
1379     to make PCRE easy to compile on non-Unix systems. It has been suggested
1380     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1381     for compiling on Windows systems. I have therefore replaced it with
1382     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1383     defaults to "extern" for C or "extern C" for C++, which works fine on
1384     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1385     SCOPE with something explicit in config.h. In addition:
1386    
1387     (a) pcreposix.h still had just "extern" instead of either of these macros;
1388     I have replaced it with PCRE_DATA_SCOPE.
1389    
1390     (b) Functions such as _pcre_xclass(), which are internal to the library,
1391     but external in the C sense, all had PCRE_EXPORT in their definitions.
1392     This is apparently wrong for the Windows case, so I have removed it.
1393     (It makes no difference on Unix-like systems.)
1394    
1395     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1396     of recursive calls to match(). This is different to MATCH_LIMIT because
1397     that limits the total number of calls to match(), not all of which increase
1398     the depth of recursion. Limiting the recursion depth limits the amount of
1399     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1400     when PCRE is compiled, and changed at run time. A patch from Google adds
1401     this functionality to the C++ interface.
1402    
1403     18. Changes to the handling of Unicode character properties:
1404    
1405     (a) Updated the table to Unicode 4.1.0.
1406    
1407     (b) Recognize characters that are not in the table as "Cn" (undefined).
1408    
1409     (c) I revised the way the table is implemented to a much improved format
1410     which includes recognition of ranges. It now supports the ranges that
1411     are defined in UnicodeData.txt, and it also amalgamates other
1412     characters into ranges. This has reduced the number of entries in the
1413     table from around 16,000 to around 3,000, thus reducing its size
1414     considerably. I realized I did not need to use a tree structure after
1415     all - a binary chop search is just as efficient. Having reduced the
1416     number of entries, I extended their size from 6 bytes to 8 bytes to
1417     allow for more data.
1418    
1419     (d) Added support for Unicode script names via properties such as \p{Han}.
1420    
1421     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1422     matching that character.
1423    
1424     20. When matching a repeated Unicode property with a minimum greater than zero,
1425     (for example \pL{2,}), PCRE could look past the end of the subject if it
1426     reached it while seeking the minimum number of characters. This could
1427     happen only if some of the characters were more than one byte long, because
1428     there is a check for at least the minimum number of bytes.
1429    
1430     21. Refactored the implementation of \p and \P so as to be more general, to
1431     allow for more different types of property in future. This has changed the
1432     compiled form incompatibly. Anybody with saved compiled patterns that use
1433     \p or \P will have to recompile them.
1434    
1435     22. Added "Any" and "L&" to the supported property types.
1436    
1437     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1438     but give a compile time error if the value is greater than 0xff.
1439    
1440     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1441     accidentally not being installed or uninstalled.
1442    
1443     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1444     made were to insert the current release number. This seemed silly, because
1445     it made things harder for people building PCRE on systems that don't run
1446     "configure". I have turned pcre.h into a distributed file, no longer built
1447     by "configure", with the version identification directly included. There is
1448     no longer a pcre.h.in file.
1449    
1450     However, this change necessitated a change to the pcre-config script as
1451     well. It is built from pcre-config.in, and one of the substitutions was the
1452     release number. I have updated configure.ac so that ./configure now finds
1453     the release number by grepping pcre.h.
1454    
1455     26. Added the ability to run the tests under valgrind.
1456    
1457    
1458 nigel 85 Version 6.4 05-Sep-05
1459     ---------------------
1460    
1461     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1462     "--" to be printed when multiple files were scanned, even when none of the
1463     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1464     consider it to be a bug, and have restored the previous behaviour.
1465    
1466     2. A couple of code tidies to get rid of compiler warnings.
1467    
1468     3. The pcretest program used to cheat by referring to symbols in the library
1469     whose names begin with _pcre_. These are internal symbols that are not
1470     really supposed to be visible externally, and in some environments it is
1471     possible to suppress them. The cheating is now confined to including
1472     certain files from the library's source, which is a bit cleaner.
1473    
1474     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1475     file's purpose clearer.
1476    
1477     5. Reorganized pcre_ucp_findchar().
1478    
1479    
1480 nigel 83 Version 6.3 15-Aug-05
1481     ---------------------
1482    
1483     1. The file libpcre.pc.in did not have general read permission in the tarball.
1484    
1485     2. There were some problems when building without C++ support:
1486    
1487     (a) If C++ support was not built, "make install" and "make test" still
1488     tried to test it.
1489    
1490     (b) There were problems when the value of CXX was explicitly set. Some
1491     changes have been made to try to fix these, and ...
1492    
1493     (c) --disable-cpp can now be used to explicitly disable C++ support.
1494    
1495     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1496     backslash in a target when C++ was disabled. This confuses some
1497     versions of "make", apparently. Using an intermediate variable solves
1498     this. (Same for CPP_LOBJ.)
1499    
1500     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1501     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1502     necessary on certain architectures.
1503    
1504     4. Added a setting of -export-symbols-regex to the link command to remove
1505     those symbols that are exported in the C sense, but actually are local
1506     within the library, and not documented. Their names all begin with
1507     "_pcre_". This is not a perfect job, because (a) we have to except some
1508     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1509     available (and never for static libraries). I have made a note to try to
1510     find a way round (a) in the future.
1511    
1512    
1513 nigel 81 Version 6.2 01-Aug-05
1514     ---------------------
1515    
1516     1. There was no test for integer overflow of quantifier values. A construction
1517     such as {1111111111111111} would give undefined results. What is worse, if
1518     a minimum quantifier for a parenthesized subpattern overflowed and became
1519     negative, the calculation of the memory size went wrong. This could have
1520     led to memory overwriting.
1521    
1522     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1523    
1524     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1525     operating environments where this matters.
1526    
1527     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1528     PCRE options from within the C++ wrapper.
1529    
1530     5. Named capturing subpatterns were not being correctly counted when a pattern
1531     was compiled. This caused two problems: (a) If there were more than 100
1532     such subpatterns, the calculation of the memory needed for the whole
1533     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1534     back references of the form \12, where the number was greater than 9, were
1535     not recognized as back references, even though there were sufficient
1536     previous subpatterns.
1537    
1538     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1539     versions of gcc, e.g. 2.95.4.
1540    
1541    
1542 nigel 79 Version 6.1 21-Jun-05
1543     ---------------------
1544    
1545     1. There was one reference to the variable "posix" in pcretest.c that was not
1546     surrounded by "#if !defined NOPOSIX".
1547    
1548     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1549     the cross-check on the old pcre_info() function, for the benefit of the
1550     cut-down version of PCRE that is currently imported into Exim.
1551    
1552     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1553     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1554     patterns that start (?i) but I don't think that matters. The use of (?i) is
1555     just an example; this all applies to the other options as well.
1556    
1557     4. Since libtool seems to echo the compile commands it is issuing, the output
1558     from "make" can be reduced a bit by putting "@" in front of each libtool
1559     compile command.
1560    
1561     5. Patch from the folks at Google for configure.in to be a bit more thorough
1562     in checking for a suitable C++ installation before trying to compile the
1563     C++ stuff. This should fix a reported problem when a compiler was present,
1564     but no suitable headers.
1565    
1566     6. The man pages all had just "PCRE" as their title. I have changed them to
1567     be the relevant file name. I have also arranged that these names are
1568     retained in the file doc/pcre.txt, which is a concatenation in text format
1569     of all the man pages except the little individual ones for each function.
1570    
1571     7. The NON-UNIX-USE file had not been updated for the different set of source
1572     files that come with release 6. I also added a few comments about the C++
1573     wrapper.
1574    
1575    
1576 nigel 77 Version 6.0 07-Jun-05
1577     ---------------------
1578    
1579     1. Some minor internal re-organization to help with my DFA experiments.
1580    
1581     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1582     didn't matter for the library itself when fully configured, but did matter
1583     when compiling without UCP support, or within Exim, where the ucp files are
1584     not imported.
1585    
1586     3. Refactoring of the library code to split up the various functions into
1587     different source modules. The addition of the new DFA matching code (see
1588     below) to a single monolithic source would have made it really too
1589     unwieldy, quite apart from causing all the code to be include in a
1590     statically linked application, when only some functions are used. This is
1591     relevant even without the DFA addition now that patterns can be compiled in
1592     one application and matched in another.
1593    
1594     The downside of splitting up is that there have to be some external
1595     functions and data tables that are used internally in different modules of
1596     the library but which are not part of the API. These have all had their
1597     names changed to start with "_pcre_" so that they are unlikely to clash
1598     with other external names.
1599    
1600     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1601     a different (DFA) algorithm. Although it is slower than the original
1602     function, it does have some advantages for certain types of matching
1603     problem.
1604    
1605     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1606     including restarting after a partial match.
1607    
1608     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1609     defined when compiling for Windows was sent to me. I have put it into the
1610     code, though I have no means of testing or verifying it.
1611    
1612     7. Added the pcre_refcount() auxiliary function.
1613    
1614     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1615     match before or at the first newline in the subject string. In pcretest,
1616     the /f option on a pattern can be used to set this.
1617    
1618     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1619     would behave wrongly. This has been present in PCRE since release 4.0.
1620    
1621     10. A number of changes to the pcregrep command:
1622    
1623     (a) Refactored how -x works; insert ^(...)$ instead of setting
1624     PCRE_ANCHORED and checking the length, in preparation for adding
1625     something similar for -w.
1626    
1627     (b) Added the -w (match as a word) option.
1628    
1629     (c) Refactored the way lines are read and buffered so as to have more
1630     than one at a time available.
1631    
1632     (d) Implemented a pcregrep test script.
1633    
1634     (e) Added the -M (multiline match) option. This allows patterns to match
1635     over several lines of the subject. The buffering ensures that at least
1636     8K, or the rest of the document (whichever is the shorter) is available
1637     for matching (and similarly the previous 8K for lookbehind assertions).
1638    
1639     (f) Changed the --help output so that it now says
1640    
1641     -w, --word-regex(p)
1642    
1643     instead of two lines, one with "regex" and the other with "regexp"
1644     because that confused at least one person since the short forms are the
1645     same. (This required a bit of code, as the output is generated
1646     automatically from a table. It wasn't just a text change.)
1647    
1648     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1649     option but starts with a hyphen. Could be a pattern or a path name
1650     starting with a hyphen, for instance.
1651    
1652     (h) "-" can be given as a file name to represent stdin.
1653    
1654     (i) When file names are being printed, "(standard input)" is used for
1655     the standard input, for compatibility with GNU grep. Previously
1656     "<stdin>" was used.
1657    
1658     (j) The option --label=xxx can be used to supply a name to be used for
1659     stdin when file names are being printed. There is no short form.
1660    
1661     (k) Re-factored the options decoding logic because we are going to add
1662     two more options that take data. Such options can now be given in four
1663     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1664    
1665     (l) Added the -A, -B, and -C options for requesting that lines of context
1666     around matches be printed.
1667    
1668     (m) Added the -L option to print the names of files that do not contain
1669     any matching lines, that is, the complement of -l.
1670    
1671     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1672     continue to scan other files.
1673    
1674     (o) The -s option was incorrectly implemented. For compatibility with other
1675     greps, it now suppresses the error message for a non-existent or non-
1676     accessible file (but not the return code). There is a new option called
1677     -q that suppresses the output of matching lines, which was what -s was
1678     previously doing.
1679    
1680     (p) Added --include and --exclude options to specify files for inclusion
1681     and exclusion when recursing.
1682    
1683     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1684     Hopefully, it now does.
1685    
1686     12. Missing cast in pcre_study().
1687    
1688     13. Added an "uninstall" target to the makefile.
1689    
1690     14. Replaced "extern" in the function prototypes in Makefile.in with
1691     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1692     world, but is set differently for Windows.
1693    
1694     15. Added a second compiling function called pcre_compile2(). The only
1695     difference is that it has an extra argument, which is a pointer to an
1696     integer error code. When there is a compile-time failure, this is set
1697     non-zero, in addition to the error test pointer being set to point to an
1698     error message. The new argument may be NULL if no error number is required
1699     (but then you may as well call pcre_compile(), which is now just a
1700     wrapper). This facility is provided because some applications need a
1701     numeric error indication, but it has also enabled me to tidy up the way
1702     compile-time errors are handled in the POSIX wrapper.
1703    
1704     16. Added VPATH=.libs to the makefile; this should help when building with one
1705     prefix path and installing with another. (Or so I'm told by someone who
1706     knows more about this stuff than I do.)
1707    
1708     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1709     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1710     match everything, including newlines. This is not POSIX-compatible, but
1711     somebody wanted the feature. From pcretest it can be activated by using
1712     both the P and the s flags.
1713    
1714     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1715    
1716     19. libpcre.pc was being incorrectly installed as executable.
1717    
1718     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1719     it now also looks for '\r' so that it will work unmodified on Windows.
1720    
1721     21. Added Google's contributed C++ wrapper to the distribution.
1722    
1723     22. Added some untidy missing memory free() calls in pcretest, to keep
1724     Electric Fence happy when testing.
1725    
1726    
1727    
1728 nigel 75 Version 5.0 13-Sep-04
1729     ---------------------
1730    
1731     1. Internal change: literal characters are no longer packed up into items
1732     containing multiple characters in a single byte-string. Each character
1733     is now matched using a separate opcode. However, there may be more than one
1734     byte in the character in UTF-8 mode.
1735    
1736     2. The pcre_callout_block structure has two new fields: pattern_position and
1737     next_item_length. These contain the offset in the pattern to the next match
1738     item, and its length, respectively.
1739    
1740     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1741     insertion of callouts before each pattern item. Added the /C option to
1742     pcretest to make use of this.
1743    
1744     4. On the advice of a Windows user, the lines
1745    
1746     #if defined(_WIN32) || defined(WIN32)
1747     _setmode( _fileno( stdout ), 0x8000 );
1748     #endif /* defined(_WIN32) || defined(WIN32) */
1749    
1750     have been added to the source of pcretest. This apparently does useful
1751     magic in relation to line terminators.
1752    
1753     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1754     for the benefit of those environments where the "b" makes a difference.
1755    
1756     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1757     to know about it. I have put a hack into configure.in that adds in code
1758     to set GCC=yes if CC=icc. This seems to end up at a point in the
1759     generated configure script that is early enough to affect the setting of
1760     compiler options, which is what is needed, but I have no means of testing
1761     whether it really works. (The user who reported this had patched the
1762     generated configure script, which of course I cannot do.)
1763    
1764     LATER: After change 22 below (new libtool files), the configure script
1765     seems to know about icc (and also ecc). Therefore, I have commented out
1766     this hack in configure.in.
1767    
1768     7. Added support for pkg-config (2 patches were sent in).
1769    
1770     8. Negated POSIX character classes that used a combination of internal tables
1771     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1772     [[:^ascii]]. Typically, they would match almost any characters. The other
1773     POSIX classes were not broken in this way.
1774    
1775     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1776     to find the match, as PCRE was deluded into thinking that the match had to
1777     start at the start point or following a newline. The same bug applied to
1778     patterns with negative forward assertions or any backward assertions
1779     preceding ".*" at the start, unless the pattern required a fixed first
1780     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1781    
1782     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1783     starting at the last subject character, bytes beyond the end of the subject
1784     string were read.
1785    
1786     11. Renamed the variable "class" as "classbits" to make life easier for C++
1787     users. (Previously there was a macro definition, but it apparently wasn't
1788     enough.)
1789    
1790     12. Added the new field "tables" to the extra data so that tables can be passed
1791     in at exec time, or the internal tables can be re-selected. This allows
1792     a compiled regex to be saved and re-used at a later time by a different
1793     program that might have everything at different addresses.
1794    
1795     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1796     -R library as well as a -L library.
1797    
1798     14. The debugging options of pcretest (-d on the command line or D on a
1799     pattern) showed incorrect output for anything following an extended class
1800     that contained multibyte characters and which was followed by a quantifier.
1801    
1802     15. Added optional support for general category Unicode character properties
1803     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1804     support. It adds about 90K to the size of the library. The meanings of the
1805     inbuilt class escapes such as \d and \s have NOT been changed.
1806    
1807     16. Updated pcredemo.c to include calls to free() to release the memory for the
1808     compiled pattern.
1809    
1810     17. The generated file chartables.c was being created in the source directory
1811     instead of in the building directory. This caused the build to fail if the
1812     source directory was different from the building directory, and was
1813     read-only.
1814    
1815     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1816     file. No doubt somebody will tell me if they don't make sense... Also added
1817     Dan Mooney's comments about building on OpenVMS.
1818    
1819     19. Added support for partial matching via the PCRE_PARTIAL option for
1820     pcre_exec() and the \P data escape in pcretest.
1821    
1822     20. Extended pcretest with 3 new pattern features:
1823    
1824     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1825     write the compiled pattern to the file whose name is "rest-of-line".
1826     This is a straight binary dump of the data, with the saved pointer to
1827     the character tables forced to be NULL. The study data, if any, is
1828     written too. After writing, pcretest reads a new pattern.
1829    
1830     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1831     compiled pattern from the given file. There must not be any
1832     occurrences of "<" in the file name (pretty unlikely); if there are,
1833     pcretest will instead treat the initial "<" as a pattern delimiter.
1834     After reading in the pattern, pcretest goes on to read data lines as
1835     usual.
1836    
1837     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1838     and 16-bit fields in a compiled pattern, to simulate a pattern that
1839     was compiled on a host of opposite endianness.
1840    
1841     21. The pcre-exec() function can now cope with patterns that were compiled on
1842     hosts of opposite endianness, with this restriction:
1843    
1844     As for any compiled expression that is saved and used later, the tables
1845     pointer field cannot be preserved; the extra_data field in the arguments
1846     to pcre_exec() should be used to pass in a tables address if a value
1847     other than the default internal tables were used at compile time.
1848    
1849     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1850     now diagnosed as an error. Previously, most of the time, a negative number
1851     would have been treated as zero, but if in addition "ovector" was passed as
1852     NULL, a crash could occur.
1853    
1854     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1855     new versions from the libtool 1.5 distribution (the last one is a copy of
1856     a file called libtool.m4). This seems to have fixed the need to patch
1857     "configure" to support Darwin 1.3 (which I used to do). However, I still
1858     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1859     workstation).
1860    
1861     24. Changed the PCRE licence to be the more standard "BSD" licence.
1862    
1863    
1864 nigel 73 Version 4.5 01-Dec-03
1865     ---------------------
1866    
1867     1. There has been some re-arrangement of the code for the match() function so
1868     that it can be compiled in a version that does not call itself recursively.
1869     Instead, it keeps those local variables that need separate instances for
1870     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1871     needs to "recurse". Keeping track of where control must go is done by means
1872     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1873     hide most of the details from the main code, and operates only if
1874     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1875     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1876     operating.
1877    
1878     To make it easier for callers to provide specially tailored get/free
1879     functions for this usage, two new functions, pcre_stack_malloc, and
1880     pcre_stack_free, are used. They are always called in strict stacking order,
1881     and the size of block requested is always the same.
1882    
1883     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1884     PCRE has been compiled to use the stack or the heap for recursion. The
1885     -C option of pcretest uses this to show which version is compiled.
1886    
1887     A new data escape \S, is added to pcretest; it causes the amounts of store
1888     obtained and freed by both kinds of malloc/free at match time to be added
1889     to the output.
1890    
1891     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1892     what's available on my current Linux desktop machine.
1893    
1894     3. When matching a UTF-8 string, the test for a valid string at the start has
1895     been extended. If start_offset is not zero, PCRE now checks that it points
1896     to a byte that is the start of a UTF-8 character. If not, it returns
1897     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1898     this is necessary because there may be backward assertions in the pattern.
1899     When matching the same subject several times, it may save resources to use
1900     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1901    
1902     4. The code for checking the validity of UTF-8 strings has been tightened so
1903     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1904     containing "overlong sequences".
1905    
1906     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1907     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1908     should have been "&", but it just so happened that all the cases this let
1909     through by mistake were picked up later in the function.
1910    
1911     6. I had used a variable called "isblank" - this is a C99 function, causing
1912     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1913    
1914     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1915     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1916     so the version is shown; (c) stop "make test" echoing "./RunTest".
1917    
1918     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1919    
1920     9. The prototype for memmove() for systems that don't have it was using
1921     size_t, but the inclusion of the header that defines size_t was later. I've
1922     moved the #includes for the C headers earlier to avoid this.
1923    
1924     10. Added some adjustments to the code to make it easier to compiler on certain
1925     special systems:
1926    
1927     (a) Some "const" qualifiers were missing.
1928     (b) Added the macro EXPORT before all exported functions; by default this
1929     is defined to be empty.
1930     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1931     that it reads its output file name as an argument instead of writing
1932     to the standard output and assuming this can be redirected.
1933    
1934     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1935     class containing characters with values greater than 255, PCRE compilation
1936     went into a loop.
1937    
1938     12. A recursive reference to a subpattern that was within another subpattern
1939     that had a minimum quantifier of zero caused PCRE to crash. For example,
1940     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1941     recursion. If the recursively-called subpattern itself had a zero repeat,
1942     that was OK.
1943    
1944     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1945     buffer into which it was copied (for escape processing) was still set at
1946     1024, so long lines caused crashes.
1947    
1948     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1949     "internal error: code overflow...". This applied to any character class
1950     that was followed by a possessive quantifier.
1951    
1952     15. Modified the Makefile to add libpcre.la as a prerequisite for
1953     libpcreposix.la because I was told this is needed for a parallel build to
1954     work.
1955    
1956     16. If a pattern that contained .* following optional items at the start was
1957     studied, the wrong optimizing data was generated, leading to matching
1958     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1959     matching string must start with a or b or c. The correct conclusion for
1960     this pattern is that a match can start with any character.
1961    
1962    
1963 nigel 71 Version 4.4 13-Aug-03
1964     ---------------------
1965    
1966     1. In UTF-8 mode, a character class containing characters with values between
1967     127 and 255 was not handled correctly if the compiled pattern was studied.
1968     In fixing this, I have also improved the studying algorithm for such
1969     classes (slightly).
1970    
1971     2. Three internal functions had redundant arguments passed to them. Removal
1972     might give a very teeny performance improvement.
1973    
1974     3. Documentation bug: the value of the capture_top field in a callout is *one
1975     more than* the number of the hightest numbered captured substring.
1976    
1977     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1978     in incorrectly linking with a previously installed version. They now link
1979     explicitly with libpcre.la.
1980    
1981     5. configure.in no longer needs to recognize Cygwin specially.
1982    
1983     6. A problem in pcre.in for Windows platforms is fixed.
1984    
1985     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1986     pcretest, it used to include the size of the study block as part of its
1987     output. Unfortunately, the structure contains a field that has a different
1988     size on different hardware architectures. This meant that the tests that
1989     showed this size failed. As the block is currently always of a fixed size,
1990     this information isn't actually particularly useful in pcretest output, so
1991     I have just removed it.
1992    
1993     8. Three pre-processor statements accidentally did not start in column 1.
1994     Sadly, there are *still* compilers around that complain, even though
1995     standard C has not required this for well over a decade. Sigh.
1996    
1997     9. In pcretest, the code for checking callouts passed small integers in the
1998     callout_data field, which is a void * field. However, some picky compilers
1999     complained about the casts involved for this on 64-bit systems. Now
2000     pcretest passes the address of the small integer instead, which should get
2001     rid of the warnings.
2002    
2003     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
2004     both compile and run time, and gives an error if an invalid UTF-8 sequence
2005     is found. There is a option for disabling this check in cases where the
2006     string is known to be correct and/or the maximum performance is wanted.
2007    
2008     11. In response to a bug report, I changed one line in Makefile.in from
2009    
2010     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
2011     to
2012     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
2013    
2014     to look similar to other lines, but I have no way of telling whether this
2015     is the right thing to do, as I do not use Windows. No doubt I'll get told
2016     if it's wrong...
2017    
2018    
2019 nigel 69 Version 4.3 21-May-03
2020     ---------------------
2021    
2022     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
2023     Makefile.
2024    
2025     2. Some refactoring to improve the quality of the code:
2026    
2027     (i) The utf8_table... variables are now declared "const".
2028    
2029     (ii) The code for \cx, which used the "case flipping" table to upper case
2030     lower case letters, now just substracts 32. This is ASCII-specific,
2031     but the whole concept of \cx is ASCII-specific, so it seems
2032     reasonable.
2033    
2034     (iii) PCRE was using its character types table to recognize decimal and
2035     hexadecimal digits in the pattern. This is silly, because it handles
2036     only 0-9, a-f, and A-F, but the character types table is locale-
2037     specific, which means strange things might happen. A private
2038     table is now used for this - though it costs 256 bytes, a table is
2039     much faster than multiple explicit tests. Of course, the standard
2040     character types table is still used for matching digits in subject
2041     strings against \d.
2042    
2043     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
2044     ending in _t are). So I've renamed it as ESC_tee.
2045    
2046     3. The first argument for regexec() in the POSIX wrapper should have been
2047     defined as "const".
2048    
2049     4. Changed pcretest to use malloc() for its buffers so that they can be
2050     Electric Fenced for debugging.
2051    
2052     5. There were several places in the code where, in UTF-8 mode, PCRE would try
2053     to read one or more bytes before the start of the subject string. Often this
2054     had no effect on PCRE's behaviour, but in some circumstances it could
2055     provoke a segmentation fault.
2056    
2057     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
2058     to try to read one or more bytes before the start of the subject string.
2059    
2060     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
2061     UTF-8 support could misbehave in various ways if the subject string
2062     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
2063     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
2064     back over UTF-8 characters.)
2065    
2066    
2067 nigel 67 Version 4.2 14-Apr-03
2068     ---------------------
2069    
2070     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
2071    
2072     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
2073     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
2074     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
2075     [WIN_PREFIX]: new variable, "cyg" for Cygwin
2076     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
2077     and BUILD_EXEEXT
2078     Note: automatic setting of the BUILD variables is not yet working
2079     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
2080     compile-time but not at link-time
2081     [LINK]: use for linking executables only
2082     make different versions for Windows and non-Windows
2083     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
2084     libraries
2085     [LINK_FOR_BUILD]: new variable
2086     [OBJEXT]: use throughout
2087     [EXEEXT]: use throughout
2088     <winshared>: new target
2089     <wininstall>: new target
2090     <dftables.o>: use native compiler
2091     <dftables>: use native linker
2092     <install>: handle Windows platform correctly
2093     <clean>: ditto
2094     <check>: ditto
2095     copy DLL to top builddir before testing
2096    
2097     As part of these changes, -no-undefined was removed again. This was reported
2098     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2099     in any case.
2100    
2101     3. Some tidies to get rid of compiler warnings:
2102    
2103     . In the match_data structure, match_limit was an unsigned long int, whereas
2104     match_call_count was an int. I've made them both unsigned long ints.
2105    
2106     . In pcretest the fact that a const uschar * doesn't automatically cast to
2107     a void * provoked a warning.
2108    
2109     . Turning on some more compiler warnings threw up some "shadow" variables
2110     and a few more missing casts.
2111    
2112     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2113     option, a class that contained a single character with a value between 128
2114     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2115    
2116     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2117     option, a class that contained several characters, but with at least one
2118     whose value was between 128 and 255 caused PCRE to crash.
2119    
2120    
2121 nigel 65 Version 4.1 12-Mar-03
2122     ---------------------
2123 nigel 63
2124 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2125     needed, and a string in dftables.c that was longer than standard compilers are
2126     required to support.
2127    
2128     2. Compiling with Sun's compiler found a few more places where the code could
2129     be tidied up in order to avoid warnings.
2130    
2131     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2132     first of these names is deprecated in the latest Autoconf in favour of the name
2133     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2134     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2135     analogy I have changed it to CFLAGS_FOR_BUILD.
2136    
2137     4. Added -no-undefined to the linking command in the Makefile, because this is
2138     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2139     linking step for the pcreposix library.
2140    
2141     5. PCRE was failing to diagnose the case of two named groups with the same
2142     name.
2143    
2144     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2145     literal character that is needed in the subject for a match, and scans along to
2146     ensure that it is present before embarking on the full matching process. This
2147     saves time in cases of nested unlimited repeats that are never going to match.
2148     Problem: the scan can take a lot of time if the subject is very long (e.g.
2149     megabytes), thus penalizing straightforward matches. It is now done only if the
2150     amount of subject to be scanned is less than 1000 bytes.
2151    
2152     7. A lesser problem with the same optimization is that it was recording the
2153     first character of an anchored pattern as "needed", thus provoking a search
2154     right along the subject, even when the first match of the pattern was going to
2155     fail. The "needed" character is now not set for anchored patterns, unless it
2156     follows something in the pattern that is of non-fixed length. Thus, it still
2157     fulfils its original purpose of finding quick non-matches in cases of nested
2158     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2159    
2160    
2161     Version 4.0 17-Feb-03
2162     ---------------------
2163    
2164 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2165     extended to the end of string, PCRE compiled incorrect data. This could lead to
2166     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2167    
2168     2. Moved to autoconf 2.53 and libtool 1.4.2.
2169    
2170     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2171     the special perltest8 script is no longer needed - all the tests can be run
2172     from a single perltest script.
2173    
2174     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2175     by \s. It has now been removed in PCRE. This means it isn't recognized as
2176     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2177     class [:space:] *does* include VT, thereby creating a mess.
2178    
2179     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2180     space and tab.
2181    
2182     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2183     its new features into the main test script, reducing the number of scripts.
2184    
2185     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2186     were backward compatible, and made the (?i) apply to the whole pattern, as if
2187     /i were given. Now it behaves more logically, and applies the option setting
2188     only to what follows. PCRE has been changed to follow suit. However, if it
2189     finds options settings right at the start of the pattern, it extracts them into
2190     the global options, as before. Thus, they show up in the info data.
2191    
2192     8. Added support for the \Q...\E escape sequence. Characters in between are
2193     treated as literals. This is slightly different from Perl in that $ and @ are
2194     also handled as literals inside the quotes. In Perl, they will cause variable
2195     interpolation. Note the following examples:
2196    
2197     Pattern PCRE matches Perl matches
2198    
2199     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2200     \Qabc\$xyz\E abc\$xyz abc\$xyz
2201     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2202    
2203     For compatibility with Perl, \Q...\E sequences are recognized inside character
2204     classes as well as outside them.
2205    
2206     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2207     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2208     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2209     signed/unsigned warnings.
2210    
2211     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2212     option for pcretest, so I've replaced it by a simple function that does just
2213     that job.
2214    
2215     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2216     "pcregrep -".
2217    
2218     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2219     Java package. This provides some syntactic sugar for simple cases of what my
2220     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2221     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2222     item, you can use this simplified notation. Note that only makes sense with
2223     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2224     greediness, whatever the setting of the PCRE_UNGREEDY option.
2225    
2226     13. A change of greediness default within a pattern was not taking effect at
2227     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2228     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2229     was abstracted outside.
2230    
2231     14. PCRE now supports the \G assertion. It is true when the current matching
2232     position is at the start point of the match. This differs from \A when the
2233     starting offset is non-zero. Used with the /g option of pcretest (or similar
2234     code), it works in the same way as it does for Perl's /g option. If all
2235     alternatives of a regex begin with \G, the expression is anchored to the start
2236     match position, and the "anchored" flag is set in the compiled expression.
2237    
2238     15. Some bugs concerning the handling of certain option changes within patterns
2239     have been fixed. These applied to options other than (?ims). For example,
2240     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2241     been the other way round. Some of this was related to change 7 above.
2242    
2243     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2244     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2245     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2246     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2247    
2248     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2249     mode. Unlike ".", it always matches newline, whatever the setting of
2250     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2251     assertions. Perl allows it, but it doesn't (in general) work because it can't
2252     calculate the length of the lookbehind. At least, that's the case for Perl
2253     5.8.0 - I've been told they are going to document that it doesn't work in
2254     future.
2255    
2256     18. Added an error diagnosis for escapes that PCRE does not support: these are
2257     \L, \l, \N, \P, \p, \U, \u, and \X.
2258    
2259     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2260     reading past the end of the pattern in cases such as /[abcd/.
2261    
2262     20. PCRE was getting more memory than necessary for patterns with classes that
2263     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2264    
2265     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2266     compiling PCRE for use with Virtual Pascal.
2267    
2268     22. Small fix to the Makefile to make it work properly if the build is done
2269     outside the source tree.
2270    
2271     23. Added a new extension: a condition to go with recursion. If a conditional
2272     subpattern starts with (?(R) the "true" branch is used if recursion has
2273     happened, whereas the "false" branch is used only at the top level.
2274    
2275     24. When there was a very long string of literal characters (over 255 bytes
2276     without UTF support, over 250 bytes with UTF support), the computation of how
2277     much memory was required could be incorrect, leading to segfaults or other
2278     strange effects.
2279    
2280     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2281     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2282     there was a subsequent back reference to those brackets. This meant that, for
2283     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2284     possible to check for precisely this case. All we can do is abandon the
2285     optimization if .* occurs inside capturing brackets when there are any back
2286     references whatsoever. (See below for a better fix that came later.)
2287    
2288     26. The handling of the optimization for finding the first character of a
2289     non-anchored pattern, and for finding a character that is required later in the
2290     match were failing in some cases. This didn't break the matching; it just
2291     failed to optimize when it could. The way this is done has been re-implemented.
2292    
2293     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2294    
2295     28. Added a new feature that provides some of the functionality that Perl
2296     provides with (?{...}). The facility is termed a "callout". The way it is done
2297     in PCRE is for the caller to provide an optional function, by setting
2298     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2299     global variable. By default it is unset, which disables all calling out. To get
2300     the function called, the regex must include (?C) at appropriate points. This
2301     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2302     This provides a means of identifying different callout points. When PCRE
2303     reaches such a point in the regex, if pcre_callout has been set, the external
2304     function is called. It is provided with data in a structure called
2305     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2306     matching continues; if it returns a non-zero value, the match at the current
2307     point fails. However, backtracking will occur if possible. [This was changed
2308     later and other features added - see item 49 below.]
2309    
2310     29. pcretest is upgraded to test the callout functionality. It provides a
2311     callout function that displays information. By default, it shows the start of
2312     the match and the current position in the text. There are some new data escapes
2313     to vary what happens:
2314    
2315     \C+ in addition, show current contents of captured substrings
2316     \C- do not supply a callout function
2317     \C!n return 1 when callout number n is reached
2318     \C!n!m return 1 when callout number n is reached for the mth time
2319    
2320     30. If pcregrep was called with the -l option and just a single file name, it
2321     output "<stdin>" if a match was found, instead of the file name.
2322    
2323     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2324     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2325     pcre_exec(). This saves a malloc/free per call. The default value of
2326     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2327     when configuring.
2328    
2329     32. The default maximum size of a compiled pattern is 64K. There have been a
2330     few cases of people hitting this limit. The code now uses macros to handle the
2331     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2332     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2333     configuring. Tests 2 and 5 work only with 2-byte links because they output
2334     debugging information about compiled patterns.
2335    
2336     33. Internal code re-arrangements:
2337    
2338     (a) Moved the debugging function for printing out a compiled regex into
2339     its own source file (printint.c) and used #include to pull it into
2340     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2341     separate copies.
2342    
2343     (b) Defined the list of op-code names for debugging as a macro in
2344     internal.h so that it is next to the definition of the opcodes.
2345    
2346     (c) Defined a table of op-code lengths for simpler skipping along compiled
2347     code. This is again a macro in internal.h so that it is next to the
2348     definition of the opcodes.
2349    
2350     34. Added support for recursive calls to individual subpatterns, along the
2351     lines of Robin Houston's patch (but implemented somewhat differently).
2352    
2353     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2354     allow it to read and process whole directories in Win32. This code was
2355     contributed by Lionel Fourquaux; it has not been tested by me.
2356    
2357     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2358     used to name a group. Names consist of alphanumerics and underscores, and must
2359     be unique. Back references use the syntax (?P=name) and recursive calls use
2360     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2361     numbers. The function pcre_fullinfo() can be used after compilation to extract
2362     a name/number map. There are three relevant calls:
2363    
2364     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2365     PCRE_INFO_NAMECOUNT yields the number of entries
2366     PCRE_INFO_NAMETABLE yields a pointer to the map.
2367    
2368     The map is a vector of fixed-size entries. The size of each entry depends on
2369     the length of the longest name used. The first two bytes of each entry are the
2370     group number, most significant byte first. There follows the corresponding
2371     name, zero terminated. The names are in alphabetical order.
2372    
2373     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2374     case instead of 255. Making it the same both with and without UTF-8 support
2375     means that the same test output works with both.
2376    
2377     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2378     calling malloc() with a zero argument.
2379    
2380     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2381     optimization. I've improved things by keeping a bitmap of backreferences with
2382     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2383     fact referenced, the optimization can be applied. It is unlikely that a
2384     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2385     the match to follow \n) will appear inside brackets with a number greater than
2386     31, but if it does, any back reference > 31 suppresses the optimization.
2387    
2388     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2389     of disabling numbered capturing parentheses. Any opening parenthesis that is
2390     not followed by ? behaves as if it were followed by ?: but named parentheses
2391     can still be used for capturing (and they will acquire numbers in the usual
2392     way).
2393    
2394     41. Redesigned the return codes from the match() function into yes/no/error so
2395     that errors can be passed back from deep inside the nested calls. A malloc
2396     failure while inside a recursive subpattern call now causes the
2397     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2398    
2399     42. It is now possible to set a limit on the number of times the match()
2400     function is called in a call to pcre_exec(). This facility makes it possible to
2401     limit the amount of recursion and backtracking, though not in a directly
2402     obvious way, because the match() function is used in a number of different
2403     circumstances. The count starts from zero for each position in the subject
2404     string (for non-anchored patterns). The default limit is, for compatibility, a
2405     large number, namely 10 000 000. You can change this in two ways:
2406    
2407     (a) When configuring PCRE before making, you can use --with-match-limit=n
2408     to set a default value for the compiled library.
2409    
2410     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2411     a different value is set. See 45 below.
2412    
2413     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2414    
2415     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2416     of things that can be changed at compile time. The first argument specifies
2417     what is wanted and the second points to where the information is to be placed.
2418     The current list of available information is:
2419    
2420     PCRE_CONFIG_UTF8
2421    
2422     The output is an integer that is set to one if UTF-8 support is available;
2423     otherwise it is set to zero.
2424    
2425     PCRE_CONFIG_NEWLINE
2426    
2427     The output is an integer that it set to the value of the code that is used for
2428     newline. It is either LF (10) or CR (13).
2429    
2430     PCRE_CONFIG_LINK_SIZE
2431    
2432     The output is an integer that contains the number of bytes used for internal
2433     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2434    
2435     PCRE_CONFIG_POSIX_MALLOC_THRESHOLD
2436    
2437     The output is an integer that contains the threshold above which the POSIX
2438     interface uses malloc() for output vectors. See item 31 above.
2439    
2440     PCRE_CONFIG_MATCH_LIMIT
2441    
2442     The output is an unsigned integer that contains the default limit of the number
2443     of match() calls in a pcre_exec() execution. See 42 above.
2444    
2445     44. pcretest has been upgraded by the addition of the -C option. This causes it
2446     to extract all the available output from the new pcre_config() function, and to
2447     output it. The program then exits immediately.
2448    
2449     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2450     order to support additional features. One way would have been to define
2451     pcre_exec2() (for example) with extra arguments, but this would not have been
2452     extensible, and would also have required all calls to the original function to
2453     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2454     is used for passing in "extra" data from pcre_study().
2455    
2456     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2457     contains the following fields:
2458    
2459     flags a bitmap indicating which of the following fields are set
2460     study_data opaque data from pcre_study()
2461     match_limit a way of specifying a limit on match() calls for a specific
2462     call to pcre_exec()
2463     callout_data data for callouts (see 49 below)
2464    
2465     The flag bits are also defined in pcre.h, and are
2466    
2467     PCRE_EXTRA_STUDY_DATA
2468     PCRE_EXTRA_MATCH_LIMIT
2469     PCRE_EXTRA_CALLOUT_DATA
2470    
2471     The pcre_study() function now returns one of these new pcre_extra blocks, with
2472     the actual study data pointed to by the study_data field, and the
2473     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2474     before. That is, this change is entirely upwards-compatible and requires no
2475     change to existing code.
2476    
2477     If you want to pass in additional data to pcre_exec(), you can either place it
2478     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2479     block.
2480    
2481     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2482     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2483     times with different match limits, until it finds the minimum value needed for
2484     pcre_exec() to complete. The value is then output. This can be instructive; for
2485     most simple matches the number is quite small, but for pathological cases it
2486     gets very large very quickly.
2487    
2488     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2489     returns the size of the data block pointed to by the study_data field in a
2490     pcre_extra block, that is, the value that was passed as the argument to
2491     pcre_malloc() when PCRE was getting memory in which to place the information
2492     created by pcre_study(). The fourth argument should point to a size_t variable.
2493     pcretest has been extended so that this information is shown after a successful
2494     pcre_study() call when information about the compiled regex is being displayed.
2495    
2496     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2497     because what follows is always an absolute path. (Later: it turns out that this
2498     is more than cosmetic for MinGW, because it doesn't like empty path
2499     components.)
2500    
2501     49. Some changes have been made to the callout feature (see 28 above):
2502    
2503     (i) A callout function now has three choices for what it returns:
2504    
2505     0 => success, carry on matching
2506     > 0 => failure at this point, but backtrack if possible
2507     < 0 => serious error, return this value from pcre_exec()
2508    
2509     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2510     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2511     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2512     use by callout functions. It will never be used by PCRE itself.
2513    
2514     (ii) The pcre_extra structure (see 45 above) has a void * field called
2515     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2516     pcre_callout_block structure has a field of the same name. The contents of
2517     the field passed in the pcre_extra structure are passed to the callout
2518     function in the corresponding field in the callout block. This makes it
2519     easier to use the same callout-containing regex from multiple threads. For
2520     testing, the pcretest program has a new data escape
2521    
2522     \C*n pass the number n (may be negative) as callout_data
2523    
2524     If the callout function in pcretest receives a non-zero value as
2525     callout_data, it returns that value.
2526    
2527     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2528     there were some redundant $(CFLAGS) in commands that are now specified as
2529     $(LINK), which already includes $(CFLAGS).
2530    
2531     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2532     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2533     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2534     one-byte characters throughout. Note that case-insensitive matching applies
2535     only to characters whose values are less than 256. PCRE doesn't support the
2536     notion of cases for higher-valued characters.
2537    
2538     (i) A character class whose characters are all within 0-255 is handled as
2539     a bit map, and the map is inverted for negative classes. Previously, a
2540     character > 255 always failed to match such a class; however it should
2541     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2542    
2543     (ii) A negated character class with a single character < 255 is coded as
2544     "not this character" (OP_NOT). This wasn't working properly when the test
2545     character was multibyte, either singly or repeated.
2546    
2547     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2548     mode, for example: \x{100}{2,3}.
2549    
2550     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2551     singly or repeated) now correctly test multibyte characters. However,
2552     PCRE doesn't recognize any characters with values greater than 255 as
2553     digits, spaces, or word characters. Such characters always match \D, \S,
2554     and \W, and never match \d, \s, or \w.
2555    
2556     (v) Classes may now contain characters and character ranges with values
2557     greater than 255. For example: [ab\x{100}-\x{400}].
2558    
2559     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2560     PCRE in UTF-8 mode.
2561    
2562     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2563     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2564     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2565     value.)
2566    
2567     53. The single man page has become too large. I have therefore split it up into
2568     a number of separate man pages. These also give rise to individual HTML pages;
2569     these are now put in a separate directory, and there is an index.html page that
2570     lists them all. Some hyperlinking between the pages has been installed.
2571    
2572     54. Added convenience functions for handling named capturing parentheses.
2573    
2574     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2575     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2576     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2577     are faulted.
2578    
2579     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2580     calling configure. These values are used when compiling the dftables.c program
2581     which is run to generate the source of the default character tables. They
2582     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2583     you will need to set these values.
2584    
2585     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2586    
2587    
2588     Version 3.9 02-Jan-02
2589 nigel 61 ---------------------
2590    
2591     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2592    
2593     2. If --disable-static was given, the building process failed when trying to
2594     build pcretest and pcregrep. (For some reason it was using libtool to compile
2595     them, which is not right, as they aren't part of the library.)
2596    
2597    
2598 nigel 59 Version 3.8 18-Dec-01
2599     ---------------------
2600    
2601     1. The experimental UTF-8 code was completely screwed up. It was packing the
2602     bytes in the wrong order. How dumb can you get?
2603    
2604    
2605 nigel 57 Version 3.7 29-Oct-01
2606     ---------------------
2607    
2608     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2609     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2610     this didn't happen under Solaris 8, where I normally test things.
2611    
2612 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2613     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2614     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2615     this fix an hour or so after the initial 3.7 release.)
2616 nigel 57
2617 nigel 59
2618 nigel 55 Version 3.6 23-Oct-01
2619     ---------------------
2620    
2621     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2622     offsets passed as NULL with zero offset count.
2623    
2624     2. The config.guess and config.sub files had not been updated when I moved to
2625     the latest autoconf.
2626    
2627    
2628 nigel 53 Version 3.5 15-Aug-01
2629     ---------------------
2630 nigel 5
2631 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2632     had been forgotten.
2633    
2634     2. By using declared but undefined structures, we can avoid using "void"
2635     definitions in pcre.h while keeping the internal definitions of the structures
2636     private.
2637    
2638     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2639     user point of view, this means that both static and shared libraries are built
2640     by default, but this can be individually controlled. More of the work of
2641     handling this static/shared cases is now inside libtool instead of PCRE's make
2642     file.
2643    
2644     4. The pcretest utility is now installed along with pcregrep because it is
2645     useful for users (to test regexs) and by doing this, it automatically gets
2646     relinked by libtool. The documentation has been turned into a man page, so
2647     there are now .1, .txt, and .html versions in /doc.
2648    
2649     5. Upgrades to pcregrep:
2650     (i) Added long-form option names like gnu grep.
2651     (ii) Added --help to list all options with an explanatory phrase.
2652     (iii) Added -r, --recursive to recurse into sub-directories.
2653     (iv) Added -f, --file to read patterns from a file.
2654    
2655     6. pcre_exec() was referring to its "code" argument before testing that
2656     argument for NULL (and giving an error if it was NULL).
2657    
2658     7. Upgraded Makefile.in to allow for compiling in a different directory from
2659     the source directory.
2660    
2661     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2662     options bits, the pointer it was passed was to an int instead of to an unsigned
2663     long int. This mattered only on 64-bit systems.
2664    
2665     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2666     generated) instead of pcre.in, which it its source. Also made the same change
2667     in several of the .c files.
2668    
2669     10. A new release of gcc defines printf() as a macro, which broke pcretest
2670     because it had an ifdef in the middle of a string argument for printf(). Fixed
2671     by using separate calls to printf().
2672    
2673     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2674     script, to force use of CR or LF instead of \n in the source. On non-Unix
2675     systems, the value can be set in config.h.
2676    
2677     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2678     absolute limit. Changed the text of the error message to make this clear, and
2679     likewise updated the man page.
2680    
2681     13. The limit of 99 on the number of capturing subpatterns has been removed.
2682     The new limit is 65535, which I hope will not be a "real" limit.
2683    
2684    
2685 nigel 51 Version 3.4 22-Aug-00
2686     ---------------------
2687    
2688     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2689    
2690     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2691    
2692    
2693 nigel 49 Version 3.3 01-Aug-00
2694     ---------------------
2695    
2696     1. If an octal character was given, but the value was greater than \377, it
2697     was not getting masked to the least significant bits, as documented. This could
2698     lead to crashes in some systems.
2699    
2700     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2701     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2702    
2703     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2704     These just pass their arguments on to (pcre_free)(), but they are provided
2705     because some uses of PCRE bind it to non-C systems that can call its functions,
2706     but cannot call free() or pcre_free() directly.
2707    
2708     4. Add "make test" as a synonym for "make check". Corrected some comments in
2709     the Makefile.
2710    
2711     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2712     Makefile.
2713    
2714     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2715     command called pgrep for grepping around the active processes.
2716    
2717     7. Added the beginnings of support for UTF-8 character strings.
2718    
2719     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2720     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2721     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2722     out for the ar command.)
2723    
2724    
2725 nigel 47 Version 3.2 12-May-00
2726     ---------------------
2727    
2728     This is purely a bug fixing release.
2729    
2730     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2731     of ZA. This was just one example of several cases that could provoke this bug,
2732     which was introduced by change 9 of version 2.00. The code for breaking
2733     infinite loops after an iteration that matches an empty string was't working
2734     correctly.
2735    
2736     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2737     when matched against abbab (for example). After matching an empty string, it
2738     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2739     caused it to match further down the string than it should.
2740    
2741     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2742     was there because it doesn't seem to be needed, and it causes trouble on some
2743     systems, as it is not a Standard C header. It has been removed.
2744    
2745     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2746     were reported on the Macintosh. The changes were from
2747    
2748     while ((c = *(++ptr)) != 0 && c != '\n');
2749     to
2750     while ((c = *(++ptr)) != 0 && c != '\n') ;
2751    
2752     Totally extraordinary, but if that's what it takes...
2753    
2754     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2755     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2756     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2757     assumes the way PCRE uses memmove() (always moving upwards).
2758    
2759     6. PCRE is being used in one environment where strchr() is not available. There
2760     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2761     faster code anyway.
2762    
2763    
2764 nigel 45 Version 3.1 09-Feb-00
2765     ---------------------
2766    
2767     The only change in this release is the fixing of some bugs in Makefile.in for
2768     the "install" target:
2769    
2770     (1) It was failing to install pcreposix.h.
2771    
2772     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2773    
2774    
2775 nigel 43 Version 3.0 01-Feb-00
2776     ---------------------
2777 nigel 41
2778     1. Add support for the /+ modifier to perltest (to output $` like it does in
2779     pcretest).
2780    
2781     2. Add support for the /g modifier to perltest.
2782    
2783     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2784     matches null strings.
2785    
2786     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2787     pattern. Perl treats empty patterns specially - it reuses the most recent
2788     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2789     effect.
2790    
2791     5. The POSIX interface was broken in that it was just handing over the POSIX
2792     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2793     required a bigger vector, with some working space on the end. This means that
2794     the POSIX wrapper now has to get and free some memory, and copy the results.
2795    
2796 nigel 43 6. Added some simple autoconf support, placing the test data and the
2797     documentation in separate directories, re-organizing some of the
2798     information files, and making it build pcre-config (a GNU standard). Also added
2799     libtool support for building PCRE as a shared library, which is now the
2800     default.
2801 nigel 41
2802 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2803     09 are not valid octal constants. Single digits will be used for minor values
2804     less than 10.
2805    
2806     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2807     existing programs that set these in the POSIX interface can use PCRE without
2808     modification.
2809    
2810     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2811     return all that pcre_info() returns, plus additional data. The pcre_info()
2812     function is retained for compatibility, but is considered to be obsolete.
2813    
2814     10. Added experimental recursion feature (?R) to handle one common case that
2815     Perl 5.6 will be able to do with (?p{...}).
2816    
2817     11. Added support for POSIX character classes like [:alpha:], which Perl is
2818     adopting.
2819    
2820    
2821 nigel 39 Version 2.08 31-Aug-99
2822     ----------------------
2823    
2824     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2825     trying to match at the startoffset position, but instead was moving forward to
2826     the next newline as if a previous match had failed.
2827    
2828     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2829     and could get into a loop if a null string was matched other than at the start
2830     of the subject.
2831    
2832     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2833     be distinguished at compile time, and for completeness also added PCRE_DATE.
2834    
2835     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2836     in GnuWin32 environments.
2837    
2838    
2839 nigel 37 Version 2.07 29-Jul-99
2840     ----------------------
2841    
2842     1. The documentation is now supplied in plain text form and HTML as well as in
2843     the form of man page sources.
2844    
2845     2. C++ compilers don't like assigning (void *) values to other pointer types.
2846     In particular this affects malloc(). Although there is no problem in Standard
2847     C, I've put in casts to keep C++ compilers happy.
2848    
2849     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2850     should be (const char *).
2851    
2852     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2853     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2854     However, I haven't made this a standard facility. The documentation doesn't
2855     mention it, and the Makefile doesn't support it.
2856    
2857     5. The Makefile now contains an "install" target, with editable destinations at
2858     the top of the file. The pcretest program is not installed.
2859    
2860     6. pgrep -V now gives the PCRE version number and date.
2861    
2862     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2863     causing the entire string to be ignored, instead of just the last character.
2864    
2865     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2866     non-matching string, it can take a very, very long time, even for strings of
2867     quite modest length, because of the nested recursion. PCRE now does better in
2868     some of these cases. It does this by remembering the last required literal
2869     character in the pattern, and pre-searching the subject to ensure it is present
2870     before running the real match. In other words, it applies a heuristic to detect
2871     some types of certain failure quickly, and in the above example, if presented
2872     with a string that has no trailing " it gives "no match" very quickly.
2873    
2874     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2875     other alternatives are tried instead.
2876    
2877    
2878 nigel 35 Version 2.06 09-Jun-99
2879     ----------------------
2880    
2881     1. Change pcretest's output for amount of store used to show just the code
2882     space, because the remainder (the data block) varies in size between 32-bit and
2883     64-bit systems.
2884    
2885     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2886     start matching at. This allows lookbehinds to work when searching for multiple
2887     occurrences in a string.
2888    
2889     3. Added additional options to pcretest for testing multiple occurrences:
2890    
2891     /+ outputs the rest of the string that follows a match
2892     /g loops for multiple occurrences, using the new startoffset argument
2893     /G loops for multiple occurrences by passing an incremented pointer
2894    
2895     4. PCRE wasn't doing the "first character" optimization for patterns starting
2896     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2897     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2898     the letter 'x'. On long subject strings, this gives a significant speed-up.
2899    
2900    
2901 nigel 33 Version 2.05 21-Apr-99
2902     ----------------------
2903    
2904     1. Changed the type of magic_number from int to long int so that it works
2905     properly on 16-bit systems.
2906    
2907     2. Fixed a bug which caused patterns starting with .* not to work correctly
2908     when the subject string contained newline characters. PCRE was assuming
2909     anchoring for such patterns in all cases, which is not correct because .* will
2910     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2911     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2912     must be retried after every newline in the subject.
2913    
2914    
2915 nigel 31 Version 2.04 18-Feb-99
2916     ----------------------
2917    
2918     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2919     computation of the store needed to hold the pattern was incorrect (too large).
2920     If such patterns were nested a few deep, this could multiply and become a real
2921     problem.
2922    
2923     2. Added /M option to pcretest to show the memory requirement of a specific
2924     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2925    
2926     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2927     compiled in such a way that the backtracking after subsequent failure was
2928     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2929     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2930    
2931    
2932 nigel 29 Version 2.03 02-Feb-99
2933     ----------------------
2934    
2935     1. Fixed typo and small mistake in man page.
2936    
2937 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2938     LICENCE file containing the conditions.
2939 nigel 29
2940     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2941     Perl, that is the internal \ allows the delimiter to be included in the
2942     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2943     the final delimiter, add \ to the end of the pattern (to test the error).
2944    
2945     4. Added the convenience functions for extracting substrings after a successful
2946     match. Updated pcretest to make it able to test these functions.
2947    
2948    
2949 nigel 27 Version 2.02 14-Jan-99
2950     ----------------------
2951    
2952     1. Initialized the working variables associated with each extraction so that
2953     their saving and restoring doesn't refer to uninitialized store.
2954    
2955     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2956     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2957     fix the problem.
2958    
2959     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2960     calls, and wasn't printing the correct value for compiling calls. Increased the
2961     default value of LOOPREPEAT, and the number of significant figures in the
2962     times.
2963    
2964     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2965    
2966     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2967     a building problem on Windows NT with a FAT file system.
2968    
2969    
2970 nigel 25 Version 2.01 21-Oct-98
2971     ----------------------
2972    
2973     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2974     to character tables built by pcre_maketables() in the current locale. If NULL
2975     is passed, the default tables are used.
2976    
2977    
2978 nigel 23 Version 2.00 24-Sep-98
2979 nigel 21 ----------------------
2980    
2981 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2982     it any more.
2983    
2984     2. Allow quantification of (?>) groups, and make it work correctly.
2985    
2986     3. The first character computation wasn't working for (?>) groups.
2987    
2988     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2989     end of the subject) and add 5.005's \z, which really does match only at the
2990     very end of the subject.
2991    
2992     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2993    
2994     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2995     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2996     localized options. All options to pcre_study() were also removed.
2997    
2998     7. Add other new features from 5.005:
2999    
3000     $(?<= positive lookbehind
3001     $(?<! negative lookbehind
3002     (?imsx-imsx) added the unsetting capability
3003     such a setting is global if at outer level; local otherwise
3004     (?imsx-imsx:) non-capturing groups with option setting
3005     (?(cond)re|re) conditional pattern matching
3006    
3007     A backreference to itself in a repeated group matches the previous
3008     captured string.
3009    
3010     8. General tidying up of studying (both automatic and via "study")
3011     consequential on the addition of new assertions.
3012    
3013     9. As in 5.005, unlimited repeated groups that could match an empty substring
3014     are no longer faulted at compile time. Instead, the loop is forcibly broken at
3015     runtime if any iteration does actually match an empty substring.
3016    
3017     10. Include the RunTest script in the distribution.
3018    
3019     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
3020     discrepancies, some of which were old and were also with respect to 5.004. They
3021     have now been fixed.
3022    
3023    
3024     Version 1.09 28-Apr-98
3025     ----------------------
3026    
3027 nigel 21 1. A negated single character class followed by a quantifier with a minimum
3028     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
3029     program crashes, or just wrong answers. This did not apply to negated classes
3030     containing more than one character, or to minima other than one.
3031    
3032    
3033 nigel 19 Version 1.08 27-Mar-98
3034     ----------------------
3035    
3036     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
3037    
3038     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
3039     latter must appear before anything that relies on it in the pattern.
3040    
3041    
3042 nigel 17 Version 1.07 16-Feb-98
3043     ----------------------
3044    
3045     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
3046     repeat of a potentially empty string).
3047    
3048    
3049 nigel 15 Version 1.06 23-Jan-98
3050     ----------------------
3051    
3052     1. Added Markus Oberhumer's little patches for C++.
3053    
3054     2. Literal strings longer than 255 characters were broken.
3055    
3056    
3057 nigel 13 Version 1.05 23-Dec-97
3058     ----------------------
3059    
3060     1. Negated character classes containing more than one character were failing if
3061     PCRE_CASELESS was set at run time.
3062    
3063    
3064 nigel 11 Version 1.04 19-Dec-97
3065     ----------------------
3066    
3067     1. Corrected the man page, where some "const" qualifiers had been omitted.
3068    
3069     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
3070     input syntax.
3071    
3072     3. Fixed memory leak which occurred when a regex with back references was
3073     matched with an offsets vector that wasn't big enough. The temporary memory
3074     that is used in this case wasn't being freed if the match failed.
3075    
3076     4. Tidied pcretest to ensure it frees memory that it gets.
3077    
3078     5. Temporary memory was being obtained in the case where the passed offsets
3079     vector was exactly big enough.
3080    
3081     6. Corrected definition of offsetof() from change 5 below.
3082    
3083     7. I had screwed up change 6 below and broken the rules for the use of
3084     setjmp(). Now fixed.
3085    
3086    
3087 nigel 9 Version 1.03 18-Dec-97
3088     ----------------------
3089    
3090     1. A erroneous regex with a missing opening parenthesis was correctly
3091     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
3092     on some systems.
3093    
3094     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3095     it was reported that one broken compiler failed on the former because "code" is
3096     also an independent variable.
3097    
3098     3. The erroneous regex a[]b caused an array overrun reference.
3099    
3100     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3101     fail on data ending with that character. (It was going on too far, and checking
3102     the next character, typically a binary zero.) This was specific to the
3103     optimized code for single-character negative classes.
3104    
3105     5. Added a contributed patch from the TIN world which does the following:
3106    
3107     + Add an undef for memmove, in case the the system defines a macro for it.
3108    
3109     + Add a definition of offsetof(), in case there isn't one. (I don't know
3110     the reason behind this - offsetof() is part of the ANSI standard - but
3111     it does no harm).
3112    
3113     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3114     most of the places where whitespace preceded '#'. I have given up and
3115     allowed the remaining 2 cases to be at the margin.
3116    
3117     + Rename some variables in pcre to eliminate shadowing. This seems very
3118     pedantic, but does no harm, of course.
3119    
3120     6. Moved the call to setjmp() into its own function, to get rid of warnings
3121     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3122    
3123     7. Constructs such as \d{8,} were compiling into the equivalent of
3124 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3125 nigel 9 outcome, but in this particular case used more store than had been allocated,
3126     which caused the bug to be discovered because it threw up an internal error.
3127    
3128     8. The debugging code in both pcre and pcretest for outputting the compiled
3129     form of a regex was going wrong in the case of back references followed by
3130     curly-bracketed repeats.
3131    
3132    
3133 nigel 7 Version 1.02 12-Dec-97
3134     ----------------------
3135    
3136     1. Typos in pcre.3 and comments in the source fixed.
3137    
3138     2. Applied a contributed patch to get rid of places where it used to remove
3139     'const' from variables, and fixed some signed/unsigned and uninitialized
3140     variable warnings.
3141    
3142     3. Added the "runtest" target to Makefile.
3143    
3144     4. Set default compiler flag to -O2 rather than just -O.
3145    
3146    
3147 nigel 5 Version 1.01 19-Nov-97
3148     ----------------------
3149    
3150     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3151     like /([ab]*)*/, that is, for classes with more than one character in them.
3152    
3153     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3154     as /((?>a*))*/ (a PCRE_EXTRA facility).
3155    
3156    
3157     Version 1.00 18-Nov-97
3158     ----------------------
3159    
3160     1. Added compile-time macros to support systems such as SunOS4 which don't have
3161     memmove() or strerror() but have other things that can be used instead.
3162    
3163     2. Arranged that "make clean" removes the executables.
3164    
3165    
3166 nigel 3 Version 0.99 27-Oct-97
3167     ----------------------
3168    
3169     1. Fixed bug in code for optimizing classes with only one character. It was
3170     initializing a 32-byte map regardless, which could cause it to run off the end
3171     of the memory it had got.
3172    
3173     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3174    
3175    
3176     Version 0.98 22-Oct-97
3177     ----------------------
3178    
3179     1. Fixed bug in code for handling temporary memory usage when there are more
3180     back references than supplied space in the ovector. This could cause segfaults.
3181    
3182    
3183     Version 0.97 21-Oct-97
3184     ----------------------
3185    
3186     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3187    
3188     2. Optimized negated single characters not to use a bit map.
3189    
3190     3. Brought error texts together as macro definitions; clarified some of them;
3191     fixed one that was wrong - it said "range out of order" when it meant "invalid
3192     escape sequence".
3193    
3194     4. Changed some char * arguments to const char *.
3195    
3196     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3197    
3198     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3199     pcretest.
3200    
3201    
3202     Version 0.96 16-Oct-97
3203     ----------------------
3204    
3205     1. Added a simple "pgrep" utility to the distribution.
3206    
3207     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3208     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3209     where "ddd" means "one or more decimal digits".
3210    
3211     3. Fixed serious bug. If a pattern had a back reference, but the call to
3212     pcre_exec() didn't supply a large enough ovector to record the related
3213     identifying subpattern, the match always failed. PCRE now remembers the number
3214     of the largest back reference, and gets some temporary memory in which to save
3215     the offsets during matching if necessary, in order to ensure that
3216     backreferences always work.
3217    
3218     4. Increased the compatibility with Perl in a number of ways:
3219    
3220     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3221     to request this handling. The option can be set at compile or exec time.
3222    
3223     (b) $ matches before a terminating newline by default; an option
3224     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3225     mode). The option can be set at compile or exec time.
3226    
3227     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3228     the same as Perl's. If the decimal number it represents is less than 10
3229     or there aren't that many previous left capturing parentheses, an octal
3230     escape is read. Inside a character class, it's always an octal escape,
3231     even if it is a single digit.
3232    
3233     (d) An escaped but undefined alphabetic character is taken as a literal,
3234     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3235     escapes.
3236    
3237     (e) {0} is now permitted. (The previous item is removed from the compiled
3238     pattern).
3239    
3240     5. Changed all the names of code files so that the basic parts are no longer
3241     than 10 characters, and abolished the teeny "globals.c" file.
3242    
3243     6. Changed the handling of character classes; they are now done with a 32-byte
3244     bit map always.
3245    
3246     7. Added the -d and /D options to pcretest to make it possible to look at the
3247     internals of compilation without having to recompile pcre.
3248    
3249    
3250     Version 0.95 23-Sep-97
3251     ----------------------
3252    
3253     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3254     \x20 at the start of a run of normal characters. These were being treated as
3255     real characters, instead of the source characters being re-checked.
3256    
3257    
3258     Version 0.94 18-Sep-97
3259     ----------------------
3260    
3261     1. The functions are now thread-safe, with the caveat that the global variables
3262     containing pointers to malloc() and free() or alternative functions are the
3263     same for all threads.
3264    
3265     2. Get pcre_study() to generate a bitmap of initial characters for non-
3266     anchored patterns when this is possible, and use it if passed to pcre_exec().
3267    
3268    
3269     Version 0.93 15-Sep-97
3270     ----------------------
3271    
3272     1. /(b)|(:+)/ was computing an incorrect first character.
3273    
3274     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3275     but not actually doing anything yet.
3276    
3277     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3278     as Perl does (e.g. [-az] or [az-]).
3279    
3280     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3281     all possible positions.
3282    
3283     5. Split up into different modules to avoid including unneeded functions in a
3284     compiled binary. However, compile and exec are still in one module. The "study"
3285     function is split off.
3286    
3287     6. The character tables are now in a separate module whose source is generated
3288     by an auxiliary program - but can then be edited by hand if required. There are
3289     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3290     toupper() in the code.
3291    
3292     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3293     make them global. Abolish the function for setting them, as the caller can now
3294     set them directly.
3295    
3296    
3297     Version 0.92 11-Sep-97
3298     ----------------------
3299    
3300     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3301     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3302    
3303     2. Caseless matching was not working in character classes if the characters in
3304     the pattern were in upper case.
3305    
3306     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3307    
3308     4. Make PCRE_ANCHORED public and accept as a compile option.
3309    
3310     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3311     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3312     pass them.
3313    
3314     6. Give an error if bad option bits passed at compile or run time.
3315    
3316     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3317     pcretest to cause it to pass that flag.
3318    
3319     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3320     options, and the first character, if set.
3321    
3322     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3323    
3324    
3325     Version 0.91 10-Sep-97
3326     ----------------------
3327    
3328     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3329     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3330    
3331     2. PCRE was looping on encountering an indefinitely repeated back reference to
3332     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3333     Perl does - treats the match as successful.
3334    
3335     ****

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