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Revision 311 - (hide annotations) (download)
Wed Jan 23 17:34:58 2008 UTC (6 years, 6 months ago) by ph10
File size: 150002 byte(s)
Applied Sheri's patch to CMakeLists.txt to add library name options and correct 
the recursion comment.

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

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