/[pcre]/code/trunk/ChangeLog
ViewVC logotype

Contents of /code/trunk/ChangeLog

Parent Directory Parent Directory | Revision Log Revision Log


Revision 351 - (hide annotations) (download)
Fri Jul 4 18:27:16 2008 UTC (6 years, 2 months ago) by ph10
File size: 156670 byte(s)
Final tidies for new Unicode property code; upgrade to Unicode 5.1.0.

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

Properties

Name Value
svn:eol-style native
svn:keywords "Author Date Id Revision Url"

webmaster@exim.org
ViewVC Help
Powered by ViewVC 1.1.12