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Revision 356 - (hide annotations) (download)
Tue Jul 8 14:14:34 2008 UTC (6 years, 1 month ago) by ph10
File size: 157437 byte(s)
Minor bugfix in pcrecpp.cc.

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

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