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Revision 323 - (hide annotations) (download)
Wed Mar 5 17:23:42 2008 UTC (7 years, 1 month ago) by ph10
File size: 151294 byte(s)
Remove a line of dead code, identified by coverity and reported by Nuno Lopes.

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


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