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Revision 332 - (hide annotations) (download)
Sat Apr 5 16:11:05 2008 UTC (7 years ago) by ph10
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Alan Lehotsky's patch for REG_STARTEND.

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


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