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Revision 322 - (hide annotations) (download)
Wed Mar 5 17:14:08 2008 UTC (6 years, 1 month ago) by ph10
File size: 151200 byte(s)
Craig's patch to pcrecpp.cc to restore ABI compatibility with pre-7.6 versions,
which defined a global no_arg variable instead of putting it in the RE class.

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

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