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Revision 353 - (hide annotations) (download)
Mon Jul 7 15:44:24 2008 UTC (6 years ago) by ph10
File size: 156894 byte(s)
Fix SKIPZERO bug in pcre_study().

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

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