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Revision 329 - (hide annotations) (download)
Fri Mar 28 12:06:36 2008 UTC (7 years, 1 month ago) by ph10
File size: 152610 byte(s)
Craig's second patch to fix the previous one.

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


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