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Revision 328 - (hide annotations) (download)
Wed Mar 26 17:39:06 2008 UTC (7 years, 1 month ago) by ph10
File size: 152547 byte(s)
Patch to pcrecpp.cc to fix an OS X linking problem.

1 nigel 3 ChangeLog for PCRE
2     ------------------
4 ph10 321 Version 7.7 05-Mar-08
5     ---------------------
7     1. Applied Craig's patch to sort out a long long problem: "If we can't convert
8     a string to a long long, pretend we don't even have a long long." This is
9     done by checking for the strtoq, strtoll, and _strtoi64 functions.
10 ph10 322
11     2. Applied Craig's patch to pcrecpp.cc to restore ABI compatibility with
12     pre-7.6 versions, which defined a global no_arg variable instead of putting
13     it in the RE class.
14 ph10 323
15     3. Remove a line of dead code, identified by coverity and reported by Nuno
16     Lopes.
17 ph10 324
18     4. Fixed two related pcregrep bugs involving -r with --include or --exclude:
19 ph10 321
20 ph10 324 (1) The include/exclude patterns were being applied to the whole pathnames
21     of files, instead of just to the final components.
23     (2) If there was more than one level of directory, the subdirectories were
24     skipped unless they satisfied the include/exclude conditions. This is
25     inconsistent with GNU grep (and could even be seen as contrary to the
26     pcregrep specification - which I improved to make it absolutely clear).
27     The action now is always to scan all levels of directory, and just
28     apply the include/exclude patterns to regular files.
29 ph10 325
30     5. Added the --include_dir and --exclude_dir patterns to pcregrep, and used
31     --exclude_dir in the tests to avoid scanning .svn directories.
32 ph10 326
33     6. Applied Craig's patch to the QuoteMeta function so that it escapes the
34     NUL character as backslash + 0 rather than backslash + NUL, because PCRE
35     doesn't support NULs in patterns.
36 ph10 327
37     7. Added some missing "const"s to declarations of static tables in
38     pcre_compile.c and pcre_dfa_exec.c.
39 ph10 328
40     8. Applied Craig's patch to pcrecpp.cc to fix a problem in OS X that was
41     caused by fix #2 above.
42 ph10 321
43 ph10 324
44 ph10 319 Version 7.6 28-Jan-08
45 ph10 300 ---------------------
47 ph10 302 1. A character class containing a very large number of characters with
48     codepoints greater than 255 (in UTF-8 mode, of course) caused a buffer
49     overflow.
50 ph10 309
51     2. Patch to cut out the "long long" test in pcrecpp_unittest when
52     HAVE_LONG_LONG is not defined.
54 ph10 303 3. Applied Christian Ehrlicher's patch to update the CMake build files to
55 ph10 304 bring them up to date and include new features. This patch includes:
56 ph10 309
57 ph10 304 - Fixed PH's badly added libz and libbz2 support.
58     - Fixed a problem with static linking.
59 ph10 312 - Added pcredemo. [But later removed - see 7 below.]
60 ph10 304 - Fixed dftables problem and added an option.
61     - Added a number of HAVE_XXX tests, including HAVE_WINDOWS_H and
63     - Added readline support for pcretest.
64 ph10 309 - Added an listing of the option settings after cmake has run.
66 ph10 314 4. A user submitted a patch to Makefile that makes it easy to create
67     "pcre.dll" under mingw when using Configure/Make. I added stuff to
68     Makefile.am that cause it to include this special target, without
69     affecting anything else. Note that the same mingw target plus all
70     the other distribution libraries and programs are now supported
71     when configuring with CMake (see 6 below) instead of with
72     Configure/Make.
73 ph10 309
74 ph10 308 5. Applied Craig's patch that moves no_arg into the RE class in the C++ code.
75     This is an attempt to solve the reported problem "pcrecpp::no_arg is not
76 ph10 309 exported in the Windows port". It has not yet been confirmed that the patch
77     solves the problem, but it does no harm.
78 ph10 313
79 ph10 311 6. Applied Sheri's patch to CMakeLists.txt to add NON_STANDARD_LIB_PREFIX and
80 ph10 319 NON_STANDARD_LIB_SUFFIX for dll names built with mingw when configured
81 ph10 314 with CMake, and also correct the comment about stack recursion.
82 ph10 313
83 ph10 312 7. Remove the automatic building of pcredemo from the ./configure system and
84 ph10 313 from CMakeLists.txt. The whole idea of pcredemo.c is that it is an example
85     of a program that users should build themselves after PCRE is installed, so
86     building it automatically is not really right. What is more, it gave
87 ph10 312 trouble in some build environments.
88 ph10 300
89 ph10 319 8. Further tidies to CMakeLists.txt from Sheri and Christian.
90 ph10 308
91 ph10 319
92 ph10 298 Version 7.5 10-Jan-08
93 ph10 263 ---------------------
95     1. Applied a patch from Craig: "This patch makes it possible to 'ignore'
96     values in parens when parsing an RE using the C++ wrapper."
97 ph10 286
98 ph10 264 2. Negative specials like \S did not work in character classes in UTF-8 mode.
99     Characters greater than 255 were excluded from the class instead of being
100     included.
101 ph10 286
102     3. The same bug as (2) above applied to negated POSIX classes such as
103 ph10 265 [:^space:].
104 ph10 286
105 ph10 267 4. PCRECPP_STATIC was referenced in pcrecpp_internal.h, but nowhere was it
106     defined or documented. It seems to have been a typo for PCRE_STATIC, so
107 ph10 286 I have changed it.
109 ph10 268 5. The construct (?&) was not diagnosed as a syntax error (it referenced the
110 ph10 286 first named subpattern) and a construct such as (?&a) would reference the
111     first named subpattern whose name started with "a" (in other words, the
112 ph10 272 length check was missing). Both these problems are fixed. "Subpattern name
113     expected" is now given for (?&) (a zero-length name), and this patch also
114     makes it give the same error for \k'' (previously it complained that that
115     was a reference to a non-existent subpattern).
116 ph10 286
117 ph10 269 6. The erroneous patterns (?+-a) and (?-+a) give different error messages;
118 ph10 286 this is right because (?- can be followed by option settings as well as by
119 ph10 269 digits. I have, however, made the messages clearer.
120 ph10 286
121 ph10 270 7. Patterns such as (?(1)a|b) (a pattern that contains fewer subpatterns
122     than the number used in the conditional) now cause a compile-time error.
123     This is actually not compatible with Perl, which accepts such patterns, but
124     treats the conditional as always being FALSE (as PCRE used to), but it
125     seems to me that giving a diagnostic is better.
126 ph10 286
127 ph10 274 8. Change "alphameric" to the more common word "alphanumeric" in comments
128 ph10 275 and messages.
129 ph10 286
130     9. Fix two occurrences of "backslash" in comments that should have been
131     "backspace".
133     10. Remove two redundant lines of code that can never be obeyed (their function
134     was moved elsewhere).
136     11. The program that makes PCRE's Unicode character property table had a bug
137     which caused it to generate incorrect table entries for sequences of
138 ph10 277 characters that have the same character type, but are in different scripts.
139 ph10 286 It amalgamated them into a single range, with the script of the first of
140 ph10 277 them. In other words, some characters were in the wrong script. There were
141     thirteen such cases, affecting characters in the following ranges:
142 ph10 286
143 ph10 277 U+002b0 - U+002c1
144     U+0060c - U+0060d
145 ph10 286 U+0061e - U+00612
146 ph10 277 U+0064b - U+0065e
147     U+0074d - U+0076d
148     U+01800 - U+01805
149     U+01d00 - U+01d77
150     U+01d9b - U+01dbf
151     U+0200b - U+0200f
152     U+030fc - U+030fe
153     U+03260 - U+0327f
154     U+0fb46 - U+0fbb1
155     U+10450 - U+1049d
156 ph10 286
157 ph10 279 12. The -o option (show only the matching part of a line) for pcregrep was not
158     compatible with GNU grep in that, if there was more than one match in a
159     line, it showed only the first of them. It now behaves in the same way as
160     GNU grep.
161 ph10 286
162     13. If the -o and -v options were combined for pcregrep, it printed a blank
163     line for every non-matching line. GNU grep prints nothing, and pcregrep now
164     does the same. The return code can be used to tell if there were any
165     non-matching lines.
167 ph10 289 14. Added --file-offsets and --line-offsets to pcregrep.
169     15. The pattern (?=something)(?R) was not being diagnosed as a potentially
170 ph10 282 infinitely looping recursion. The bug was that positive lookaheads were not
171 ph10 286 being skipped when checking for a possible empty match (negative lookaheads
172     and both kinds of lookbehind were skipped).
174 ph10 289 16. Fixed two typos in the Windows-only code in pcregrep.c, and moved the
175 ph10 284 inclusion of <windows.h> to before rather than after the definition of
176     INVALID_FILE_ATTRIBUTES (patch from David Byron).
177 ph10 263
178 ph10 289 17. Specifying a possessive quantifier with a specific limit for a Unicode
179 ph10 286 character property caused pcre_compile() to compile bad code, which led at
180     runtime to PCRE_ERROR_INTERNAL (-14). Examples of patterns that caused this
181     are: /\p{Zl}{2,3}+/8 and /\p{Cc}{2}+/8. It was the possessive "+" that
182     caused the error; without that there was no problem.
183 ph10 263
184 ph10 289 18. Added --enable-pcregrep-libz and --enable-pcregrep-libbz2.
185 ph10 286
186 ph10 289 19. Added --enable-pcretest-libreadline.
187 ph10 286
188 ph10 289 20. In pcrecpp.cc, the variable 'count' was incremented twice in
189 ph10 288 RE::GlobalReplace(). As a result, the number of replacements returned was
190 ph10 298 double what it should be. I removed one of the increments, but Craig sent a
191     later patch that removed the other one (the right fix) and added unit tests
192     that check the return values (which was not done before).
193 ph10 292
194 ph10 291 21. Several CMake things:
195 ph10 287
196 ph10 291 (1) Arranged that, when cmake is used on Unix, the libraries end up with
197 ph10 292 the names libpcre and libpcreposix, not just pcre and pcreposix.
198 ph10 288
199 ph10 292 (2) The above change means that pcretest and pcregrep are now correctly
200     linked with the newly-built libraries, not previously installed ones.
201 ph10 291
203 ph10 298
204     22. In UTF-8 mode, with newline set to "any", a pattern such as .*a.*=.b.*
205     crashed when matching a string such as a\x{2029}b (note that \x{2029} is a
206     UTF-8 newline character). The key issue is that the pattern starts .*;
207     this means that the match must be either at the beginning, or after a
208     newline. The bug was in the code for advancing after a failed match and
209     checking that the new position followed a newline. It was not taking
210 ph10 294 account of UTF-8 characters correctly.
211 ph10 298
212     23. PCRE was behaving differently from Perl in the way it recognized POSIX
213     character classes. PCRE was not treating the sequence [:...:] as a
214     character class unless the ... were all letters. Perl, however, seems to
215     allow any characters between [: and :], though of course it rejects as
216     unknown any "names" that contain non-letters, because all the known class
217     names consist only of letters. Thus, Perl gives an error for [[:1234:]],
218     for example, whereas PCRE did not - it did not recognize a POSIX character
219     class. This seemed a bit dangerous, so the code has been changed to be
220     closer to Perl. The behaviour is not identical to Perl, because PCRE will
221     diagnose an unknown class for, for example, [[:l\ower:]] where Perl will
222     treat it as [[:lower:]]. However, PCRE does now give "unknown" errors where
223     Perl does, and where it didn't before.
225 ph10 296 24. Rewrite so as to remove the single use of %n from pcregrep because in some
226     Windows environments %n is disabled by default.
227 ph10 292
229 ph10 260 Version 7.4 21-Sep-07
230 ph10 230 ---------------------
232     1. Change 7.3/28 was implemented for classes by looking at the bitmap. This
233 ph10 231 means that a class such as [\s] counted as "explicit reference to CR or
234     LF". That isn't really right - the whole point of the change was to try to
235     help when there was an actual mention of one of the two characters. So now
236     the change happens only if \r or \n (or a literal CR or LF) character is
237 ph10 230 encountered.
238 ph10 231
239     2. The 32-bit options word was also used for 6 internal flags, but the numbers
240     of both had grown to the point where there were only 3 bits left.
241     Fortunately, there was spare space in the data structure, and so I have
242     moved the internal flags into a new 16-bit field to free up more option
243 ph10 230 bits.
244 ph10 231
245     3. The appearance of (?J) at the start of a pattern set the DUPNAMES option,
246     but did not set the internal JCHANGED flag - either of these is enough to
247     control the way the "get" function works - but the PCRE_INFO_JCHANGED
248     facility is supposed to tell if (?J) was ever used, so now (?J) at the
249 ph10 230 start sets both bits.
251 ph10 231 4. Added options (at build time, compile time, exec time) to change \R from
252     matching any Unicode line ending sequence to just matching CR, LF, or CRLF.
253 ph10 230
254 ph10 243 5. doc/pcresyntax.html was missing from the distribution.
256     6. Put back the definition of PCRE_ERROR_NULLWSLIMIT, for backward
257 ph10 233 compatibility, even though it is no longer used.
258 ph10 243
259     7. Added macro for snprintf to pcrecpp_unittest.cc and also for strtoll and
260 ph10 254 strtoull to pcrecpp.cc to select the available functions in WIN32 when the
261 ph10 259 windows.h file is present (where different names are used). [This was
262 ph10 257 reversed later after testing - see 16 below.]
263 ph10 243
264     8. Changed all #include <config.h> to #include "config.h". There were also
265 ph10 236 some further <pcre.h> cases that I changed to "pcre.h".
266 ph10 243
267 ph10 239 9. When pcregrep was used with the --colour option, it missed the line ending
268 ph10 243 sequence off the lines that it output.
270     10. It was pointed out to me that arrays of string pointers cause lots of
271     relocations when a shared library is dynamically loaded. A technique of
272     using a single long string with a table of offsets can drastically reduce
273     these. I have refactored PCRE in four places to do this. The result is
274 ph10 240 dramatic:
275 ph10 243
276 ph10 240 Originally: 290
277     After changing UCP table: 187
278 ph10 243 After changing error message table: 43
279 ph10 240 After changing table of "verbs" 36
280     After changing table of Posix names 22
281 ph10 243
282 ph10 240 Thanks to the folks working on Gregex for glib for this insight.
283 ph10 247
284 ph10 244 11. --disable-stack-for-recursion caused compiling to fail unless -enable-
285 ph10 247 unicode-properties was also set.
287 ph10 248 12. Updated the tests so that they work when \R is defaulted to ANYCRLF.
288 ph10 231
289 ph10 253 13. Added checks for ANY and ANYCRLF to pcrecpp.cc where it previously
290     checked only for CRLF.
291 ph10 233
292 ph10 259 14. Added casts to pcretest.c to avoid compiler warnings.
294 ph10 256 15. Added Craig's patch to various pcrecpp modules to avoid compiler warnings.
295 ph10 253
296 ph10 257 16. Added Craig's patch to remove the WINDOWS_H tests, that were not working,
297 ph10 259 and instead check for _strtoi64 explicitly, and avoid the use of snprintf()
298     entirely. This removes changes made in 7 above.
299 ph10 256
300 ph10 261 17. The CMake files have been updated, and there is now more information about
301     building with CMake in the NON-UNIX-USE document.
302 ph10 257
303 ph10 261
304 ph10 228 Version 7.3 28-Aug-07
305 ph10 157 ---------------------
307 ph10 189 1. In the rejigging of the build system that eventually resulted in 7.1, the
308     line "#include <pcre.h>" was included in pcre_internal.h. The use of angle
309     brackets there is not right, since it causes compilers to look for an
310     installed pcre.h, not the version that is in the source that is being
311     compiled (which of course may be different). I have changed it back to:
312 ph10 197
313 ph10 189 #include "pcre.h"
314 ph10 197
315     I have a vague recollection that the change was concerned with compiling in
316     different directories, but in the new build system, that is taken care of
317     by the VPATH setting the Makefile.
319 ph10 190 2. The pattern .*$ when run in not-DOTALL UTF-8 mode with newline=any failed
320     when the subject happened to end in the byte 0x85 (e.g. if the last
321     character was \x{1ec5}). *Character* 0x85 is one of the "any" newline
322     characters but of course it shouldn't be taken as a newline when it is part
323     of another character. The bug was that, for an unlimited repeat of . in
324     not-DOTALL UTF-8 mode, PCRE was advancing by bytes rather than by
325     characters when looking for a newline.
326 ph10 197
327     3. A small performance improvement in the DOTALL UTF-8 mode .* case.
329     4. Debugging: adjusted the names of opcodes for different kinds of parentheses
330     in debug output.
332 ph10 201 5. Arrange to use "%I64d" instead of "%lld" and "%I64u" instead of "%llu" for
333     long printing in the pcrecpp unittest when running under MinGW.
334 ph10 189
335 ph10 197 6. ESC_K was left out of the EBCDIC table.
336 ph10 189
337 ph10 197 7. Change 7.0/38 introduced a new limit on the number of nested non-capturing
338     parentheses; I made it 1000, which seemed large enough. Unfortunately, the
339     limit also applies to "virtual nesting" when a pattern is recursive, and in
340     this case 1000 isn't so big. I have been able to remove this limit at the
341     expense of backing off one optimization in certain circumstances. Normally,
342     when pcre_exec() would call its internal match() function recursively and
343     immediately return the result unconditionally, it uses a "tail recursion"
344     feature to save stack. However, when a subpattern that can match an empty
345     string has an unlimited repetition quantifier, it no longer makes this
346     optimization. That gives it a stack frame in which to save the data for
347     checking that an empty string has been matched. Previously this was taken
348     from the 1000-entry workspace that had been reserved. So now there is no
349     explicit limit, but more stack is used.
350 ph10 189
351 ph10 200 8. Applied Daniel's patches to solve problems with the import/export magic
352     syntax that is required for Windows, and which was going wrong for the
353     pcreposix and pcrecpp parts of the library. These were overlooked when this
354     problem was solved for the main library.
355 ph10 197
356 ph10 202 9. There were some crude static tests to avoid integer overflow when computing
357     the size of patterns that contain repeated groups with explicit upper
358     limits. As the maximum quantifier is 65535, the maximum group length was
359     set at 30,000 so that the product of these two numbers did not overflow a
360     32-bit integer. However, it turns out that people want to use groups that
361     are longer than 30,000 bytes (though not repeat them that many times).
362     Change 7.0/17 (the refactoring of the way the pattern size is computed) has
363     made it possible to implement the integer overflow checks in a much more
364     dynamic way, which I have now done. The artificial limitation on group
365     length has been removed - we now have only the limit on the total length of
366     the compiled pattern, which depends on the LINK_SIZE setting.
367 ph10 208
368     10. Fixed a bug in the documentation for get/copy named substring when
369     duplicate names are permitted. If none of the named substrings are set, the
370     functions return PCRE_ERROR_NOSUBSTRING (7); the doc said they returned an
371     empty string.
373     11. Because Perl interprets \Q...\E at a high level, and ignores orphan \E
374     instances, patterns such as [\Q\E] or [\E] or even [^\E] cause an error,
375     because the ] is interpreted as the first data character and the
376     terminating ] is not found. PCRE has been made compatible with Perl in this
377     regard. Previously, it interpreted [\Q\E] as an empty class, and [\E] could
378     cause memory overwriting.
380 ph10 206 10. Like Perl, PCRE automatically breaks an unlimited repeat after an empty
381     string has been matched (to stop an infinite loop). It was not recognizing
382 ph10 208 a conditional subpattern that could match an empty string if that
383 ph10 206 subpattern was within another subpattern. For example, it looped when
384 ph10 208 trying to match (((?(1)X|))*) but it was OK with ((?(1)X|)*) where the
385 ph10 206 condition was not nested. This bug has been fixed.
386 ph10 208
387 ph10 207 12. A pattern like \X?\d or \P{L}?\d in non-UTF-8 mode could cause a backtrack
388     past the start of the subject in the presence of bytes with the top bit
389     set, for example "\x8aBCD".
390 ph10 211
391 ph10 210 13. Added Perl 5.10 experimental backtracking controls (*FAIL), (*F), (*PRUNE),
392     (*SKIP), (*THEN), (*COMMIT), and (*ACCEPT).
393 ph10 200
394 ph10 211 14. Optimized (?!) to (*FAIL).
395 ph10 202
396 ph10 212 15. Updated the test for a valid UTF-8 string to conform to the later RFC 3629.
397     This restricts code points to be within the range 0 to 0x10FFFF, excluding
398     the "low surrogate" sequence 0xD800 to 0xDFFF. Previously, PCRE allowed the
399     full range 0 to 0x7FFFFFFF, as defined by RFC 2279. Internally, it still
400     does: it's just the validity check that is more restrictive.
401 ph10 220
402     16. Inserted checks for integer overflows during escape sequence (backslash)
403     processing, and also fixed erroneous offset values for syntax errors during
404     backslash processing.
406 ph10 214 17. Fixed another case of looking too far back in non-UTF-8 mode (cf 12 above)
407 ph10 220 for patterns like [\PPP\x8a]{1,}\x80 with the subject "A\x80".
409 ph10 215 18. An unterminated class in a pattern like (?1)\c[ with a "forward reference"
410     caused an overrun.
411 ph10 220
412     19. A pattern like (?:[\PPa*]*){8,} which had an "extended class" (one with
413     something other than just ASCII characters) inside a group that had an
414     unlimited repeat caused a loop at compile time (while checking to see
415     whether the group could match an empty string).
417 ph10 217 20. Debugging a pattern containing \p or \P could cause a crash. For example,
418     [\P{Any}] did so. (Error in the code for printing property names.)
419 ph10 210
420 ph10 220 21. An orphan \E inside a character class could cause a crash.
422     22. A repeated capturing bracket such as (A)? could cause a wild memory
423 ph10 218 reference during compilation.
424 ph10 220
425     23. There are several functions in pcre_compile() that scan along a compiled
426     expression for various reasons (e.g. to see if it's fixed length for look
427 ph10 218 behind). There were bugs in these functions when a repeated \p or \P was
428 ph10 220 present in the pattern. These operators have additional parameters compared
429     with \d, etc, and these were not being taken into account when moving along
430 ph10 218 the compiled data. Specifically:
431 ph10 220
432     (a) A item such as \p{Yi}{3} in a lookbehind was not treated as fixed
433     length.
435     (b) An item such as \pL+ within a repeated group could cause crashes or
436 ph10 218 loops.
437 ph10 220
438 ph10 218 (c) A pattern such as \p{Yi}+(\P{Yi}+)(?1) could give an incorrect
439 ph10 220 "reference to non-existent subpattern" error.
441 ph10 221 (d) A pattern like (\P{Yi}{2}\277)? could loop at compile time.
443 ph10 219 24. A repeated \S or \W in UTF-8 mode could give wrong answers when multibyte
444 ph10 220 characters were involved (for example /\S{2}/8g with "A\x{a3}BC").
445 ph10 211
446 ph10 222 25. Using pcregrep in multiline, inverted mode (-Mv) caused it to loop.
447 ph10 218
448 ph10 227 26. Patterns such as [\P{Yi}A] which include \p or \P and just one other
449 ph10 223 character were causing crashes (broken optimization).
450 ph10 227
451 ph10 224 27. Patterns such as (\P{Yi}*\277)* (group with possible zero repeat containing
452 ph10 227 \p or \P) caused a compile-time loop.
454 ph10 226 28. More problems have arisen in unanchored patterns when CRLF is a valid line
455     break. For example, the unstudied pattern [\r\n]A does not match the string
456     "\r\nA" because change 7.0/46 below moves the current point on by two
457     characters after failing to match at the start. However, the pattern \nA
458 ph10 227 *does* match, because it doesn't start till \n, and if [\r\n]A is studied,
459     the same is true. There doesn't seem any very clean way out of this, but
460     what I have chosen to do makes the common cases work: PCRE now takes note
461     of whether there can be an explicit match for \r or \n anywhere in the
462     pattern, and if so, 7.0/46 no longer applies. As part of this change,
463     there's a new PCRE_INFO_HASCRORLF option for finding out whether a compiled
464     pattern has explicit CR or LF references.
465 ph10 222
466 ph10 227 29. Added (*CR) etc for changing newline setting at start of pattern.
467 ph10 223
468 ph10 227
469 ph10 189 Version 7.2 19-Jun-07
470     ---------------------
472 ph10 157 1. If the fr_FR locale cannot be found for test 3, try the "french" locale,
473     which is apparently normally available under Windows.
474 ph10 159
475     2. Re-jig the pcregrep tests with different newline settings in an attempt
476     to make them independent of the local environment's newline setting.
477 ph10 157
478 ph10 160 3. Add code to configure.ac to remove -g from the CFLAGS default settings.
479 ph10 165
480 ph10 161 4. Some of the "internals" tests were previously cut out when the link size
481     was not 2, because the output contained actual offsets. The recent new
482 ph10 165 "Z" feature of pcretest means that these can be cut out, making the tests
483     usable with all link sizes.
485 ph10 164 5. Implemented Stan Switzer's goto replacement for longjmp() when not using
486     stack recursion. This gives a massive performance boost under BSD, but just
487 ph10 165 a small improvement under Linux. However, it saves one field in the frame
488 ph10 164 in all cases.
489 ph10 172
490 ph10 166 6. Added more features from the forthcoming Perl 5.10:
491 ph10 172
492 ph10 166 (a) (?-n) (where n is a string of digits) is a relative subroutine or
493     recursion call. It refers to the nth most recently opened parentheses.
494 ph10 172
495 ph10 166 (b) (?+n) is also a relative subroutine call; it refers to the nth next
496 ph10 172 to be opened parentheses.
498     (c) Conditions that refer to capturing parentheses can be specified
499 ph10 167 relatively, for example, (?(-2)... or (?(+3)...
500 ph10 172
501 ph10 168 (d) \K resets the start of the current match so that everything before
502 ph10 172 is not part of it.
504 ph10 171 (e) \k{name} is synonymous with \k<name> and \k'name' (.NET compatible).
505 ph10 172
506 ph10 171 (f) \g{name} is another synonym - part of Perl 5.10's unification of
507 ph10 172 reference syntax.
508 ph10 182
509 ph10 175 (g) (?| introduces a group in which the numbering of parentheses in each
510 ph10 182 alternative starts with the same number.
511 ph10 172
512 ph10 182 (h) \h, \H, \v, and \V match horizontal and vertical whitespace.
514 ph10 172 7. Added two new calls to pcre_fullinfo(): PCRE_INFO_OKPARTIAL and
517     8. A pattern such as (.*(.)?)* caused pcre_exec() to fail by either not
518     terminating or by crashing. Diagnosed by Viktor Griph; it was in the code
519 ph10 170 for detecting groups that can match an empty string.
520 ph10 159
521 ph10 172 9. A pattern with a very large number of alternatives (more than several
522     hundred) was running out of internal workspace during the pre-compile
523     phase, where pcre_compile() figures out how much memory will be needed. A
524     bit of new cunning has reduced the workspace needed for groups with
525     alternatives. The 1000-alternative test pattern now uses 12 bytes of
526     workspace instead of running out of the 4096 that are available.
527 ph10 182
528 ph10 176 10. Inserted some missing (unsigned int) casts to get rid of compiler warnings.
529 ph10 172
530 ph10 179 11. Applied patch from Google to remove an optimization that didn't quite work.
531     The report of the bug said:
532 ph10 182
533 ph10 179 pcrecpp::RE("a*").FullMatch("aaa") matches, while
534     pcrecpp::RE("a*?").FullMatch("aaa") does not, and
535 ph10 182 pcrecpp::RE("a*?\\z").FullMatch("aaa") does again.
536 ph10 185
537 ph10 184 12. If \p or \P was used in non-UTF-8 mode on a character greater than 127
538 ph10 185 it matched the wrong number of bytes.
539 ph10 172
540 ph10 179
541 ph10 155 Version 7.1 24-Apr-07
542 ph10 98 ---------------------
544 ph10 111 1. Applied Bob Rossi and Daniel G's patches to convert the build system to one
545 ph10 122 that is more "standard", making use of automake and other Autotools. There
546 ph10 99 is some re-arrangement of the files and adjustment of comments consequent
547     on this.
548 ph10 111
549     2. Part of the patch fixed a problem with the pcregrep tests. The test of -r
550     for recursive directory scanning broke on some systems because the files
551     are not scanned in any specific order and on different systems the order
552     was different. A call to "sort" has been inserted into RunGrepTest for the
553     approprate test as a short-term fix. In the longer term there may be an
554 ph10 100 alternative.
555 ph10 111
556 ph10 100 3. I had an email from Eric Raymond about problems translating some of PCRE's
557 ph10 111 man pages to HTML (despite the fact that I distribute HTML pages, some
558     people do their own conversions for various reasons). The problems
559     concerned the use of low-level troff macros .br and .in. I have therefore
560     removed all such uses from the man pages (some were redundant, some could
561 ph10 113 be replaced by .nf/.fi pairs). The 132html script that I use to generate
562     HTML has been updated to handle .nf/.fi and to complain if it encounters
563     .br or .in.
564 ph10 111
565 ph10 100 4. Updated comments in configure.ac that get placed in config.h.in and also
566 ph10 123 arranged for config.h to be included in the distribution, with the name
567 ph10 111 config.h.generic, for the benefit of those who have to compile without
568     Autotools (compare pcre.h, which is now distributed as pcre.h.generic).
570     5. Updated the support (such as it is) for Virtual Pascal, thanks to Stefan
571     Weber: (1) pcre_internal.h was missing some function renames; (2) updated
572 ph10 127 makevp.bat for the current PCRE, using the additional files
573 ph10 135 makevp_c.txt, makevp_l.txt, and pcregexp.pas.
574 ph10 111
575     6. A Windows user reported a minor discrepancy with test 2, which turned out
576     to be caused by a trailing space on an input line that had got lost in his
577 ph10 102 copy. The trailing space was an accident, so I've just removed it.
578 ph10 111
579 ph10 104 7. Add -Wl,-R... flags in pcre-config.in for *BSD* systems, as I'm told
580 ph10 111 that is needed.
582 ph10 105 8. Mark ucp_table (in ucptable.h) and ucp_gentype (in pcre_ucp_searchfuncs.c)
583     as "const" (a) because they are and (b) because it helps the PHP
584     maintainers who have recently made a script to detect big data structures
585 ph10 111 in the php code that should be moved to the .rodata section. I remembered
586     to update Builducptable as well, so it won't revert if ucptable.h is ever
587 ph10 105 re-created.
588 ph10 111
589     9. Added some extra #ifdef SUPPORT_UTF8 conditionals into pcretest.c,
590 ph10 107 pcre_printint.src, pcre_compile.c, pcre_study.c, and pcre_tables.c, in
591 ph10 111 order to be able to cut out the UTF-8 tables in the latter when UTF-8
592     support is not required. This saves 1.5-2K of code, which is important in
593 ph10 107 some applications.
594 ph10 111
595 ph10 110 Later: more #ifdefs are needed in pcre_ord2utf8.c and pcre_valid_utf8.c
596 ph10 111 so as not to refer to the tables, even though these functions will never be
597     called when UTF-8 support is disabled. Otherwise there are problems with a
598     shared library.
600 ph10 118 10. Fixed two bugs in the emulated memmove() function in pcre_internal.h:
602     (a) It was defining its arguments as char * instead of void *.
604 ph10 123 (b) It was assuming that all moves were upwards in memory; this was true
605     a long time ago when I wrote it, but is no longer the case.
607 ph10 118 The emulated memove() is provided for those environments that have neither
608 ph10 123 memmove() nor bcopy(). I didn't think anyone used it these days, but that
609 ph10 118 is clearly not the case, as these two bugs were recently reported.
610 ph10 123
611 ph10 111 11. The script PrepareRelease is now distributed: it calls 132html, CleanTxt,
612 ph10 123 and Detrail to create the HTML documentation, the .txt form of the man
613     pages, and it removes trailing spaces from listed files. It also creates
614     pcre.h.generic and config.h.generic from pcre.h and config.h. In the latter
615     case, it wraps all the #defines with #ifndefs. This script should be run
616 ph10 111 before "make dist".
617 ph10 123
618 ph10 115 12. Fixed two fairly obscure bugs concerned with quantified caseless matching
619     with Unicode property support.
620 ph10 123
621     (a) For a maximizing quantifier, if the two different cases of the
622     character were of different lengths in their UTF-8 codings (there are
623     some cases like this - I found 11), and the matching function had to
624 ph10 115 back up over a mixture of the two cases, it incorrectly assumed they
625     were both the same length.
626 ph10 123
627     (b) When PCRE was configured to use the heap rather than the stack for
628     recursion during matching, it was not correctly preserving the data for
629     the other case of a UTF-8 character when checking ahead for a match
630     while processing a minimizing repeat. If the check also involved
631 ph10 115 matching a wide character, but failed, corruption could cause an
632     erroneous result when trying to check for a repeat of the original
633     character.
634 ph10 123
635 ph10 116 13. Some tidying changes to the testing mechanism:
636 ph10 98
637 ph10 116 (a) The RunTest script now detects the internal link size and whether there
638     is UTF-8 and UCP support by running ./pcretest -C instead of relying on
639 ph10 123 values substituted by "configure". (The RunGrepTest script already did
640     this for UTF-8.) The configure.ac script no longer substitutes the
641     relevant variables.
643 ph10 116 (b) The debugging options /B and /D in pcretest show the compiled bytecode
644     with length and offset values. This means that the output is different
645     for different internal link sizes. Test 2 is skipped for link sizes
646     other than 2 because of this, bypassing the problem. Unfortunately,
647     there was also a test in test 3 (the locale tests) that used /B and
648 ph10 123 failed for link sizes other than 2. Rather than cut the whole test out,
649     I have added a new /Z option to pcretest that replaces the length and
650     offset values with spaces. This is now used to make test 3 independent
651 ph10 122 of link size. (Test 2 will be tidied up later.)
652 ph10 123
653     14. If erroroffset was passed as NULL to pcre_compile, it provoked a
654 ph10 122 segmentation fault instead of returning the appropriate error message.
655 ph10 134
656 ph10 131 15. In multiline mode when the newline sequence was set to "any", the pattern
657 ph10 134 ^$ would give a match between the \r and \n of a subject such as "A\r\nB".
658     This doesn't seem right; it now treats the CRLF combination as the line
659     ending, and so does not match in that case. It's only a pattern such as ^$
660     that would hit this one: something like ^ABC$ would have failed after \r
661     and then tried again after \r\n.
663 ph10 131 16. Changed the comparison command for RunGrepTest from "diff -u" to "diff -ub"
664 ph10 134 in an attempt to make files that differ only in their line terminators
665     compare equal. This works on Linux.
666 ph10 142
667 ph10 141 17. Under certain error circumstances pcregrep might try to free random memory
668     as it exited. This is now fixed, thanks to valgrind.
669 ph10 142
670 ph10 141 19. In pcretest, if the pattern /(?m)^$/g<any> was matched against the string
671 ph10 142 "abc\r\n\r\n", it found an unwanted second match after the second \r. This
672     was because its rules for how to advance for /g after matching an empty
673 ph10 143 string at the end of a line did not allow for this case. They now check for
674     it specially.
675 ph10 150
676     20. pcretest is supposed to handle patterns and data of any length, by
677     extending its buffers when necessary. It was getting this wrong when the
678 ph10 147 buffer for a data line had to be extended.
679 ph10 150
680 ph10 149 21. Added PCRE_NEWLINE_ANYCRLF which is like ANY, but matches only CR, LF, or
681 ph10 150 CRLF as a newline sequence.
682 ph10 152
683 ph10 151 22. Code for handling Unicode properties in pcre_dfa_exec() wasn't being cut
684 ph10 152 out by #ifdef SUPPORT_UCP. This did no harm, as it could never be used, but
685     I have nevertheless tidied it up.
686 ph10 111
687 ph10 152 23. Added some casts to kill warnings from HP-UX ia64 compiler.
688 ph10 123
689 ph10 153 24. Added a man page for pcre-config.
690 ph10 152
691 ph10 153
692 nigel 93 Version 7.0 19-Dec-06
693     ---------------------
695     1. Fixed a signed/unsigned compiler warning in pcre_compile.c, shown up by
696     moving to gcc 4.1.1.
698     2. The -S option for pcretest uses setrlimit(); I had omitted to #include
699     sys/time.h, which is documented as needed for this function. It doesn't
700     seem to matter on Linux, but it showed up on some releases of OS X.
702     3. It seems that there are systems where bytes whose values are greater than
703     127 match isprint() in the "C" locale. The "C" locale should be the
704     default when a C program starts up. In most systems, only ASCII printing
705     characters match isprint(). This difference caused the output from pcretest
706     to vary, making some of the tests fail. I have changed pcretest so that:
708     (a) When it is outputting text in the compiled version of a pattern, bytes
709     other than 32-126 are always shown as hex escapes.
711     (b) When it is outputting text that is a matched part of a subject string,
712     it does the same, unless a different locale has been set for the match
713     (using the /L modifier). In this case, it uses isprint() to decide.
715     4. Fixed a major bug that caused incorrect computation of the amount of memory
716     required for a compiled pattern when options that changed within the
717     pattern affected the logic of the preliminary scan that determines the
718     length. The relevant options are -x, and -i in UTF-8 mode. The result was
719     that the computed length was too small. The symptoms of this bug were
720     either the PCRE error "internal error: code overflow" from pcre_compile(),
721     or a glibc crash with a message such as "pcretest: free(): invalid next
722     size (fast)". Examples of patterns that provoked this bug (shown in
723     pcretest format) are:
725     /(?-x: )/x
726     /(?x)(?-x: \s*#\s*)/
727     /((?i)[\x{c0}])/8
728     /(?i:[\x{c0}])/8
730     HOWEVER: Change 17 below makes this fix obsolete as the memory computation
731     is now done differently.
733     5. Applied patches from Google to: (a) add a QuoteMeta function to the C++
734     wrapper classes; (b) implement a new function in the C++ scanner that is
735     more efficient than the old way of doing things because it avoids levels of
736     recursion in the regex matching; (c) add a paragraph to the documentation
737     for the FullMatch() function.
739     6. The escape sequence \n was being treated as whatever was defined as
740     "newline". Not only was this contrary to the documentation, which states
741     that \n is character 10 (hex 0A), but it also went horribly wrong when
742     "newline" was defined as CRLF. This has been fixed.
744     7. In pcre_dfa_exec.c the value of an unsigned integer (the variable called c)
745     was being set to -1 for the "end of line" case (supposedly a value that no
746     character can have). Though this value is never used (the check for end of
747     line is "zero bytes in current character"), it caused compiler complaints.
748     I've changed it to 0xffffffff.
750     8. In pcre_version.c, the version string was being built by a sequence of
751     C macros that, in the event of PCRE_PRERELEASE being defined as an empty
752     string (as it is for production releases) called a macro with an empty
753     argument. The C standard says the result of this is undefined. The gcc
754     compiler treats it as an empty string (which was what was wanted) but it is
755     reported that Visual C gives an error. The source has been hacked around to
756     avoid this problem.
758     9. On the advice of a Windows user, included <io.h> and <fcntl.h> in Windows
759     builds of pcretest, and changed the call to _setmode() to use _O_BINARY
760     instead of 0x8000. Made all the #ifdefs test both _WIN32 and WIN32 (not all
761     of them did).
763     10. Originally, pcretest opened its input and output without "b"; then I was
764     told that "b" was needed in some environments, so it was added for release
765     5.0 to both the input and output. (It makes no difference on Unix-like
766     systems.) Later I was told that it is wrong for the input on Windows. I've
767     now abstracted the modes into two macros, to make it easier to fiddle with
768     them, and removed "b" from the input mode under Windows.
770     11. Added pkgconfig support for the C++ wrapper library, libpcrecpp.
772     12. Added -help and --help to pcretest as an official way of being reminded
773     of the options.
775     13. Removed some redundant semicolons after macro calls in pcrecpparg.h.in
776     and pcrecpp.cc because they annoy compilers at high warning levels.
778     14. A bit of tidying/refactoring in pcre_exec.c in the main bumpalong loop.
780     15. Fixed an occurrence of == in configure.ac that should have been = (shell
781     scripts are not C programs :-) and which was not noticed because it works
782     on Linux.
784     16. pcretest is supposed to handle any length of pattern and data line (as one
785     line or as a continued sequence of lines) by extending its input buffer if
786     necessary. This feature was broken for very long pattern lines, leading to
787     a string of junk being passed to pcre_compile() if the pattern was longer
788     than about 50K.
790     17. I have done a major re-factoring of the way pcre_compile() computes the
791     amount of memory needed for a compiled pattern. Previously, there was code
792     that made a preliminary scan of the pattern in order to do this. That was
793     OK when PCRE was new, but as the facilities have expanded, it has become
794     harder and harder to keep it in step with the real compile phase, and there
795     have been a number of bugs (see for example, 4 above). I have now found a
796     cunning way of running the real compile function in a "fake" mode that
797     enables it to compute how much memory it would need, while actually only
798     ever using a few hundred bytes of working memory and without too many
799     tests of the mode. This should make future maintenance and development
800     easier. A side effect of this work is that the limit of 200 on the nesting
801     depth of parentheses has been removed (though this was never a serious
802     limitation, I suspect). However, there is a downside: pcre_compile() now
803     runs more slowly than before (30% or more, depending on the pattern). I
804     hope this isn't a big issue. There is no effect on runtime performance.
806     18. Fixed a minor bug in pcretest: if a pattern line was not terminated by a
807     newline (only possible for the last line of a file) and it was a
808     pattern that set a locale (followed by /Lsomething), pcretest crashed.
810     19. Added additional timing features to pcretest. (1) The -tm option now times
811     matching only, not compiling. (2) Both -t and -tm can be followed, as a
812     separate command line item, by a number that specifies the number of
813     repeats to use when timing. The default is 50000; this gives better
814     precision, but takes uncomfortably long for very large patterns.
816     20. Extended pcre_study() to be more clever in cases where a branch of a
817     subpattern has no definite first character. For example, (a*|b*)[cd] would
818     previously give no result from pcre_study(). Now it recognizes that the
819     first character must be a, b, c, or d.
821     21. There was an incorrect error "recursive call could loop indefinitely" if
822     a subpattern (or the entire pattern) that was being tested for matching an
823     empty string contained only one non-empty item after a nested subpattern.
824     For example, the pattern (?>\x{100}*)\d(?R) provoked this error
825     incorrectly, because the \d was being skipped in the check.
827     22. The pcretest program now has a new pattern option /B and a command line
828     option -b, which is equivalent to adding /B to every pattern. This causes
829     it to show the compiled bytecode, without the additional information that
830     -d shows. The effect of -d is now the same as -b with -i (and similarly, /D
831     is the same as /B/I).
833     23. A new optimization is now able automatically to treat some sequences such
834     as a*b as a*+b. More specifically, if something simple (such as a character
835     or a simple class like \d) has an unlimited quantifier, and is followed by
836     something that cannot possibly match the quantified thing, the quantifier
837     is automatically "possessified".
839     24. A recursive reference to a subpattern whose number was greater than 39
840     went wrong under certain circumstances in UTF-8 mode. This bug could also
841     have affected the operation of pcre_study().
843     25. Realized that a little bit of performance could be had by replacing
844     (c & 0xc0) == 0xc0 with c >= 0xc0 when processing UTF-8 characters.
846     26. Timing data from pcretest is now shown to 4 decimal places instead of 3.
848     27. Possessive quantifiers such as a++ were previously implemented by turning
849     them into atomic groups such as ($>a+). Now they have their own opcodes,
850     which improves performance. This includes the automatically created ones
851     from 23 above.
853     28. A pattern such as (?=(\w+))\1: which simulates an atomic group using a
854     lookahead was broken if it was not anchored. PCRE was mistakenly expecting
855     the first matched character to be a colon. This applied both to named and
856     numbered groups.
858     29. The ucpinternal.h header file was missing its idempotency #ifdef.
860     30. I was sent a "project" file called libpcre.a.dev which I understand makes
861     building PCRE on Windows easier, so I have included it in the distribution.
863     31. There is now a check in pcretest against a ridiculously large number being
864     returned by pcre_exec() or pcre_dfa_exec(). If this happens in a /g or /G
865     loop, the loop is abandoned.
867     32. Forward references to subpatterns in conditions such as (?(2)...) where
868     subpattern 2 is defined later cause pcre_compile() to search forwards in
869     the pattern for the relevant set of parentheses. This search went wrong
870     when there were unescaped parentheses in a character class, parentheses
871     escaped with \Q...\E, or parentheses in a #-comment in /x mode.
873     33. "Subroutine" calls and backreferences were previously restricted to
874     referencing subpatterns earlier in the regex. This restriction has now
875     been removed.
877     34. Added a number of extra features that are going to be in Perl 5.10. On the
878     whole, these are just syntactic alternatives for features that PCRE had
879     previously implemented using the Python syntax or my own invention. The
880     other formats are all retained for compatibility.
882     (a) Named groups can now be defined as (?<name>...) or (?'name'...) as well
883     as (?P<name>...). The new forms, as well as being in Perl 5.10, are
884     also .NET compatible.
886     (b) A recursion or subroutine call to a named group can now be defined as
887     (?&name) as well as (?P>name).
889     (c) A backreference to a named group can now be defined as \k<name> or
890     \k'name' as well as (?P=name). The new forms, as well as being in Perl
891     5.10, are also .NET compatible.
893     (d) A conditional reference to a named group can now use the syntax
894     (?(<name>) or (?('name') as well as (?(name).
896     (e) A "conditional group" of the form (?(DEFINE)...) can be used to define
897     groups (named and numbered) that are never evaluated inline, but can be
898     called as "subroutines" from elsewhere. In effect, the DEFINE condition
899     is always false. There may be only one alternative in such a group.
901     (f) A test for recursion can be given as (?(R1).. or (?(R&name)... as well
902     as the simple (?(R). The condition is true only if the most recent
903     recursion is that of the given number or name. It does not search out
904     through the entire recursion stack.
906     (g) The escape \gN or \g{N} has been added, where N is a positive or
907     negative number, specifying an absolute or relative reference.
909     35. Tidied to get rid of some further signed/unsigned compiler warnings and
910     some "unreachable code" warnings.
912     36. Updated the Unicode property tables to Unicode version 5.0.0. Amongst other
913     things, this adds five new scripts.
915     37. Perl ignores orphaned \E escapes completely. PCRE now does the same.
916     There were also incompatibilities regarding the handling of \Q..\E inside
917     character classes, for example with patterns like [\Qa\E-\Qz\E] where the
918     hyphen was adjacent to \Q or \E. I hope I've cleared all this up now.
920     38. Like Perl, PCRE detects when an indefinitely repeated parenthesized group
921     matches an empty string, and forcibly breaks the loop. There were bugs in
922     this code in non-simple cases. For a pattern such as ^(a()*)* matched
923     against aaaa the result was just "a" rather than "aaaa", for example. Two
924     separate and independent bugs (that affected different cases) have been
925     fixed.
927     39. Refactored the code to abolish the use of different opcodes for small
928     capturing bracket numbers. This is a tidy that I avoided doing when I
929     removed the limit on the number of capturing brackets for 3.5 back in 2001.
930     The new approach is not only tidier, it makes it possible to reduce the
931     memory needed to fix the previous bug (38).
933     40. Implemented PCRE_NEWLINE_ANY to recognize any of the Unicode newline
934     sequences (http://unicode.org/unicode/reports/tr18/) as "newline" when
935     processing dot, circumflex, or dollar metacharacters, or #-comments in /x
936     mode.
938     41. Add \R to match any Unicode newline sequence, as suggested in the Unicode
939     report.
941     42. Applied patch, originally from Ari Pollak, modified by Google, to allow
942     copy construction and assignment in the C++ wrapper.
944     43. Updated pcregrep to support "--newline=any". In the process, I fixed a
945     couple of bugs that could have given wrong results in the "--newline=crlf"
946     case.
948     44. Added a number of casts and did some reorganization of signed/unsigned int
949     variables following suggestions from Dair Grant. Also renamed the variable
950     "this" as "item" because it is a C++ keyword.
952     45. Arranged for dftables to add
954     #include "pcre_internal.h"
956     to pcre_chartables.c because without it, gcc 4.x may remove the array
957     definition from the final binary if PCRE is built into a static library and
958     dead code stripping is activated.
960     46. For an unanchored pattern, if a match attempt fails at the start of a
961     newline sequence, and the newline setting is CRLF or ANY, and the next two
962     characters are CRLF, advance by two characters instead of one.
965 nigel 91 Version 6.7 04-Jul-06
966     ---------------------
968     1. In order to handle tests when input lines are enormously long, pcretest has
969     been re-factored so that it automatically extends its buffers when
970     necessary. The code is crude, but this _is_ just a test program. The
971     default size has been increased from 32K to 50K.
973     2. The code in pcre_study() was using the value of the re argument before
974     testing it for NULL. (Of course, in any sensible call of the function, it
975     won't be NULL.)
977     3. The memmove() emulation function in pcre_internal.h, which is used on
978     systems that lack both memmove() and bcopy() - that is, hardly ever -
979     was missing a "static" storage class specifier.
981     4. When UTF-8 mode was not set, PCRE looped when compiling certain patterns
982     containing an extended class (one that cannot be represented by a bitmap
983     because it contains high-valued characters or Unicode property items, e.g.
984     [\pZ]). Almost always one would set UTF-8 mode when processing such a
985     pattern, but PCRE should not loop if you do not (it no longer does).
986     [Detail: two cases were found: (a) a repeated subpattern containing an
987     extended class; (b) a recursive reference to a subpattern that followed a
988     previous extended class. It wasn't skipping over the extended class
989     correctly when UTF-8 mode was not set.]
991     5. A negated single-character class was not being recognized as fixed-length
992     in lookbehind assertions such as (?<=[^f]), leading to an incorrect
993     compile error "lookbehind assertion is not fixed length".
995     6. The RunPerlTest auxiliary script was showing an unexpected difference
996     between PCRE and Perl for UTF-8 tests. It turns out that it is hard to
997     write a Perl script that can interpret lines of an input file either as
998     byte characters or as UTF-8, which is what "perltest" was being required to
999     do for the non-UTF-8 and UTF-8 tests, respectively. Essentially what you
1000     can't do is switch easily at run time between having the "use utf8;" pragma
1001     or not. In the end, I fudged it by using the RunPerlTest script to insert
1002     "use utf8;" explicitly for the UTF-8 tests.
1004     7. In multiline (/m) mode, PCRE was matching ^ after a terminating newline at
1005     the end of the subject string, contrary to the documentation and to what
1006     Perl does. This was true of both matching functions. Now it matches only at
1007     the start of the subject and immediately after *internal* newlines.
1009     8. A call of pcre_fullinfo() from pcretest to get the option bits was passing
1010     a pointer to an int instead of a pointer to an unsigned long int. This
1011     caused problems on 64-bit systems.
1013     9. Applied a patch from the folks at Google to pcrecpp.cc, to fix "another
1014     instance of the 'standard' template library not being so standard".
1016     10. There was no check on the number of named subpatterns nor the maximum
1017     length of a subpattern name. The product of these values is used to compute
1018     the size of the memory block for a compiled pattern. By supplying a very
1019     long subpattern name and a large number of named subpatterns, the size
1020     computation could be caused to overflow. This is now prevented by limiting
1021     the length of names to 32 characters, and the number of named subpatterns
1022     to 10,000.
1024     11. Subpatterns that are repeated with specific counts have to be replicated in
1025     the compiled pattern. The size of memory for this was computed from the
1026     length of the subpattern and the repeat count. The latter is limited to
1027     65535, but there was no limit on the former, meaning that integer overflow
1028     could in principle occur. The compiled length of a repeated subpattern is
1029     now limited to 30,000 bytes in order to prevent this.
1031     12. Added the optional facility to have named substrings with the same name.
1033     13. Added the ability to use a named substring as a condition, using the
1034     Python syntax: (?(name)yes|no). This overloads (?(R)... and names that
1035     are numbers (not recommended). Forward references are permitted.
1037     14. Added forward references in named backreferences (if you see what I mean).
1039     15. In UTF-8 mode, with the PCRE_DOTALL option set, a quantified dot in the
1040     pattern could run off the end of the subject. For example, the pattern
1041     "(?s)(.{1,5})"8 did this with the subject "ab".
1043     16. If PCRE_DOTALL or PCRE_MULTILINE were set, pcre_dfa_exec() behaved as if
1044     PCRE_CASELESS was set when matching characters that were quantified with ?
1045     or *.
1047     17. A character class other than a single negated character that had a minimum
1048     but no maximum quantifier - for example [ab]{6,} - was not handled
1049     correctly by pce_dfa_exec(). It would match only one character.
1051     18. A valid (though odd) pattern that looked like a POSIX character
1052     class but used an invalid character after [ (for example [[,abc,]]) caused
1053     pcre_compile() to give the error "Failed: internal error: code overflow" or
1054     in some cases to crash with a glibc free() error. This could even happen if
1055     the pattern terminated after [[ but there just happened to be a sequence of
1056     letters, a binary zero, and a closing ] in the memory that followed.
1058     19. Perl's treatment of octal escapes in the range \400 to \777 has changed
1059     over the years. Originally (before any Unicode support), just the bottom 8
1060     bits were taken. Thus, for example, \500 really meant \100. Nowadays the
1061     output from "man perlunicode" includes this:
1063     The regular expression compiler produces polymorphic opcodes. That
1064     is, the pattern adapts to the data and automatically switches to
1065     the Unicode character scheme when presented with Unicode data--or
1066     instead uses a traditional byte scheme when presented with byte
1067     data.
1069     Sadly, a wide octal escape does not cause a switch, and in a string with
1070     no other multibyte characters, these octal escapes are treated as before.
1071     Thus, in Perl, the pattern /\500/ actually matches \100 but the pattern
1072     /\500|\x{1ff}/ matches \500 or \777 because the whole thing is treated as a
1073     Unicode string.
1075     I have not perpetrated such confusion in PCRE. Up till now, it took just
1076     the bottom 8 bits, as in old Perl. I have now made octal escapes with
1077     values greater than \377 illegal in non-UTF-8 mode. In UTF-8 mode they
1078     translate to the appropriate multibyte character.
1080     29. Applied some refactoring to reduce the number of warnings from Microsoft
1081     and Borland compilers. This has included removing the fudge introduced
1082     seven years ago for the OS/2 compiler (see 2.02/2 below) because it caused
1083     a warning about an unused variable.
1085     21. PCRE has not included VT (character 0x0b) in the set of whitespace
1086     characters since release 4.0, because Perl (from release 5.004) does not.
1087     [Or at least, is documented not to: some releases seem to be in conflict
1088     with the documentation.] However, when a pattern was studied with
1089     pcre_study() and all its branches started with \s, PCRE still included VT
1090     as a possible starting character. Of course, this did no harm; it just
1091     caused an unnecessary match attempt.
1093     22. Removed a now-redundant internal flag bit that recorded the fact that case
1094     dependency changed within the pattern. This was once needed for "required
1095     byte" processing, but is no longer used. This recovers a now-scarce options
1096     bit. Also moved the least significant internal flag bit to the most-
1097     significant bit of the word, which was not previously used (hangover from
1098     the days when it was an int rather than a uint) to free up another bit for
1099     the future.
1101     23. Added support for CRLF line endings as well as CR and LF. As well as the
1102     default being selectable at build time, it can now be changed at runtime
1103     via the PCRE_NEWLINE_xxx flags. There are now options for pcregrep to
1104     specify that it is scanning data with non-default line endings.
1106     24. Changed the definition of CXXLINK to make it agree with the definition of
1107     LINK in the Makefile, by replacing LDFLAGS to CXXFLAGS.
1109     25. Applied Ian Taylor's patches to avoid using another stack frame for tail
1110     recursions. This makes a big different to stack usage for some patterns.
1112     26. If a subpattern containing a named recursion or subroutine reference such
1113     as (?P>B) was quantified, for example (xxx(?P>B)){3}, the calculation of
1114     the space required for the compiled pattern went wrong and gave too small a
1115     value. Depending on the environment, this could lead to "Failed: internal
1116     error: code overflow at offset 49" or "glibc detected double free or
1117     corruption" errors.
1119     27. Applied patches from Google (a) to support the new newline modes and (b) to
1120     advance over multibyte UTF-8 characters in GlobalReplace.
1122     28. Change free() to pcre_free() in pcredemo.c. Apparently this makes a
1123     difference for some implementation of PCRE in some Windows version.
1125     29. Added some extra testing facilities to pcretest:
1127     \q<number> in a data line sets the "match limit" value
1128     \Q<number> in a data line sets the "match recursion limt" value
1129     -S <number> sets the stack size, where <number> is in megabytes
1131     The -S option isn't available for Windows.
1134 nigel 89 Version 6.6 06-Feb-06
1135     ---------------------
1137     1. Change 16(a) for 6.5 broke things, because PCRE_DATA_SCOPE was not defined
1138     in pcreposix.h. I have copied the definition from pcre.h.
1140     2. Change 25 for 6.5 broke compilation in a build directory out-of-tree
1141     because pcre.h is no longer a built file.
1143     3. Added Jeff Friedl's additional debugging patches to pcregrep. These are
1144     not normally included in the compiled code.
1147 nigel 87 Version 6.5 01-Feb-06
1148     ---------------------
1150     1. When using the partial match feature with pcre_dfa_exec(), it was not
1151     anchoring the second and subsequent partial matches at the new starting
1152     point. This could lead to incorrect results. For example, with the pattern
1153     /1234/, partially matching against "123" and then "a4" gave a match.
1155     2. Changes to pcregrep:
1157     (a) All non-match returns from pcre_exec() were being treated as failures
1158     to match the line. Now, unless the error is PCRE_ERROR_NOMATCH, an
1159     error message is output. Some extra information is given for the
1161     probably the only errors that are likely to be caused by users (by
1162     specifying a regex that has nested indefinite repeats, for instance).
1163     If there are more than 20 of these errors, pcregrep is abandoned.
1165     (b) A binary zero was treated as data while matching, but terminated the
1166     output line if it was written out. This has been fixed: binary zeroes
1167     are now no different to any other data bytes.
1169     (c) Whichever of the LC_ALL or LC_CTYPE environment variables is set is
1170     used to set a locale for matching. The --locale=xxxx long option has
1171     been added (no short equivalent) to specify a locale explicitly on the
1172     pcregrep command, overriding the environment variables.
1174     (d) When -B was used with -n, some line numbers in the output were one less
1175     than they should have been.
1177     (e) Added the -o (--only-matching) option.
1179     (f) If -A or -C was used with -c (count only), some lines of context were
1180     accidentally printed for the final match.
1182     (g) Added the -H (--with-filename) option.
1184     (h) The combination of options -rh failed to suppress file names for files
1185     that were found from directory arguments.
1187     (i) Added the -D (--devices) and -d (--directories) options.
1189     (j) Added the -F (--fixed-strings) option.
1191     (k) Allow "-" to be used as a file name for -f as well as for a data file.
1193     (l) Added the --colo(u)r option.
1195     (m) Added Jeffrey Friedl's -S testing option, but within #ifdefs so that it
1196     is not present by default.
1198     3. A nasty bug was discovered in the handling of recursive patterns, that is,
1199     items such as (?R) or (?1), when the recursion could match a number of
1200     alternatives. If it matched one of the alternatives, but subsequently,
1201     outside the recursion, there was a failure, the code tried to back up into
1202     the recursion. However, because of the way PCRE is implemented, this is not
1203     possible, and the result was an incorrect result from the match.
1205     In order to prevent this happening, the specification of recursion has
1206     been changed so that all such subpatterns are automatically treated as
1207     atomic groups. Thus, for example, (?R) is treated as if it were (?>(?R)).
1209     4. I had overlooked the fact that, in some locales, there are characters for
1210     which isalpha() is true but neither isupper() nor islower() are true. In
1211     the fr_FR locale, for instance, the \xAA and \xBA characters (ordmasculine
1212     and ordfeminine) are like this. This affected the treatment of \w and \W
1213     when they appeared in character classes, but not when they appeared outside
1214     a character class. The bit map for "word" characters is now created
1215     separately from the results of isalnum() instead of just taking it from the
1216     upper, lower, and digit maps. (Plus the underscore character, of course.)
1218     5. The above bug also affected the handling of POSIX character classes such as
1219     [[:alpha:]] and [[:alnum:]]. These do not have their own bit maps in PCRE's
1220     permanent tables. Instead, the bit maps for such a class were previously
1221     created as the appropriate unions of the upper, lower, and digit bitmaps.
1222     Now they are created by subtraction from the [[:word:]] class, which has
1223     its own bitmap.
1225     6. The [[:blank:]] character class matches horizontal, but not vertical space.
1226     It is created by subtracting the vertical space characters (\x09, \x0a,
1227     \x0b, \x0c) from the [[:space:]] bitmap. Previously, however, the
1228     subtraction was done in the overall bitmap for a character class, meaning
1229     that a class such as [\x0c[:blank:]] was incorrect because \x0c would not
1230     be recognized. This bug has been fixed.
1232     7. Patches from the folks at Google:
1234     (a) pcrecpp.cc: "to handle a corner case that may or may not happen in
1235     real life, but is still worth protecting against".
1237     (b) pcrecpp.cc: "corrects a bug when negative radixes are used with
1238     regular expressions".
1240     (c) pcre_scanner.cc: avoid use of std::count() because not all systems
1241     have it.
1243     (d) Split off pcrecpparg.h from pcrecpp.h and had the former built by
1244     "configure" and the latter not, in order to fix a problem somebody had
1245     with compiling the Arg class on HP-UX.
1247     (e) Improve the error-handling of the C++ wrapper a little bit.
1249     (f) New tests for checking recursion limiting.
1251     8. The pcre_memmove() function, which is used only if the environment does not
1252     have a standard memmove() function (and is therefore rarely compiled),
1253     contained two bugs: (a) use of int instead of size_t, and (b) it was not
1254     returning a result (though PCRE never actually uses the result).
1256     9. In the POSIX regexec() interface, if nmatch is specified as a ridiculously
1257     large number - greater than INT_MAX/(3*sizeof(int)) - REG_ESPACE is
1258     returned instead of calling malloc() with an overflowing number that would
1259     most likely cause subsequent chaos.
1261     10. The debugging option of pcretest was not showing the NO_AUTO_CAPTURE flag.
1263     11. The POSIX flag REG_NOSUB is now supported. When a pattern that was compiled
1264     with this option is matched, the nmatch and pmatch options of regexec() are
1265     ignored.
1267     12. Added REG_UTF8 to the POSIX interface. This is not defined by POSIX, but is
1268     provided in case anyone wants to the the POSIX interface with UTF-8
1269     strings.
1271     13. Added CXXLDFLAGS to the Makefile parameters to provide settings only on the
1272     C++ linking (needed for some HP-UX environments).
1274     14. Avoid compiler warnings in get_ucpname() when compiled without UCP support
1275     (unused parameter) and in the pcre_printint() function (omitted "default"
1276     switch label when the default is to do nothing).
1278     15. Added some code to make it possible, when PCRE is compiled as a C++
1279     library, to replace subject pointers for pcre_exec() with a smart pointer
1280     class, thus making it possible to process discontinuous strings.
1282     16. The two macros PCRE_EXPORT and PCRE_DATA_SCOPE are confusing, and perform
1283     much the same function. They were added by different people who were trying
1284     to make PCRE easy to compile on non-Unix systems. It has been suggested
1285     that PCRE_EXPORT be abolished now that there is more automatic apparatus
1286     for compiling on Windows systems. I have therefore replaced it with
1287     PCRE_DATA_SCOPE. This is set automatically for Windows; if not set it
1288     defaults to "extern" for C or "extern C" for C++, which works fine on
1289     Unix-like systems. It is now possible to override the value of PCRE_DATA_
1290     SCOPE with something explicit in config.h. In addition:
1292     (a) pcreposix.h still had just "extern" instead of either of these macros;
1293     I have replaced it with PCRE_DATA_SCOPE.
1295     (b) Functions such as _pcre_xclass(), which are internal to the library,
1296     but external in the C sense, all had PCRE_EXPORT in their definitions.
1297     This is apparently wrong for the Windows case, so I have removed it.
1298     (It makes no difference on Unix-like systems.)
1300     17. Added a new limit, MATCH_LIMIT_RECURSION, which limits the depth of nesting
1301     of recursive calls to match(). This is different to MATCH_LIMIT because
1302     that limits the total number of calls to match(), not all of which increase
1303     the depth of recursion. Limiting the recursion depth limits the amount of
1304     stack (or heap if NO_RECURSE is set) that is used. The default can be set
1305     when PCRE is compiled, and changed at run time. A patch from Google adds
1306     this functionality to the C++ interface.
1308     18. Changes to the handling of Unicode character properties:
1310     (a) Updated the table to Unicode 4.1.0.
1312     (b) Recognize characters that are not in the table as "Cn" (undefined).
1314     (c) I revised the way the table is implemented to a much improved format
1315     which includes recognition of ranges. It now supports the ranges that
1316     are defined in UnicodeData.txt, and it also amalgamates other
1317     characters into ranges. This has reduced the number of entries in the
1318     table from around 16,000 to around 3,000, thus reducing its size
1319     considerably. I realized I did not need to use a tree structure after
1320     all - a binary chop search is just as efficient. Having reduced the
1321     number of entries, I extended their size from 6 bytes to 8 bytes to
1322     allow for more data.
1324     (d) Added support for Unicode script names via properties such as \p{Han}.
1326     19. In UTF-8 mode, a backslash followed by a non-Ascii character was not
1327     matching that character.
1329     20. When matching a repeated Unicode property with a minimum greater than zero,
1330     (for example \pL{2,}), PCRE could look past the end of the subject if it
1331     reached it while seeking the minimum number of characters. This could
1332     happen only if some of the characters were more than one byte long, because
1333     there is a check for at least the minimum number of bytes.
1335     21. Refactored the implementation of \p and \P so as to be more general, to
1336     allow for more different types of property in future. This has changed the
1337     compiled form incompatibly. Anybody with saved compiled patterns that use
1338     \p or \P will have to recompile them.
1340     22. Added "Any" and "L&" to the supported property types.
1342     23. Recognize \x{...} as a code point specifier, even when not in UTF-8 mode,
1343     but give a compile time error if the value is greater than 0xff.
1345     24. The man pages for pcrepartial, pcreprecompile, and pcre_compile2 were
1346     accidentally not being installed or uninstalled.
1348     25. The pcre.h file was built from pcre.h.in, but the only changes that were
1349     made were to insert the current release number. This seemed silly, because
1350     it made things harder for people building PCRE on systems that don't run
1351     "configure". I have turned pcre.h into a distributed file, no longer built
1352     by "configure", with the version identification directly included. There is
1353     no longer a pcre.h.in file.
1355     However, this change necessitated a change to the pcre-config script as
1356     well. It is built from pcre-config.in, and one of the substitutions was the
1357     release number. I have updated configure.ac so that ./configure now finds
1358     the release number by grepping pcre.h.
1360     26. Added the ability to run the tests under valgrind.
1363 nigel 85 Version 6.4 05-Sep-05
1364     ---------------------
1366     1. Change 6.0/10/(l) to pcregrep introduced a bug that caused separator lines
1367     "--" to be printed when multiple files were scanned, even when none of the
1368     -A, -B, or -C options were used. This is not compatible with Gnu grep, so I
1369     consider it to be a bug, and have restored the previous behaviour.
1371     2. A couple of code tidies to get rid of compiler warnings.
1373     3. The pcretest program used to cheat by referring to symbols in the library
1374     whose names begin with _pcre_. These are internal symbols that are not
1375     really supposed to be visible externally, and in some environments it is
1376     possible to suppress them. The cheating is now confined to including
1377     certain files from the library's source, which is a bit cleaner.
1379     4. Renamed pcre.in as pcre.h.in to go with pcrecpp.h.in; it also makes the
1380     file's purpose clearer.
1382     5. Reorganized pcre_ucp_findchar().
1385 nigel 83 Version 6.3 15-Aug-05
1386     ---------------------
1388     1. The file libpcre.pc.in did not have general read permission in the tarball.
1390     2. There were some problems when building without C++ support:
1392     (a) If C++ support was not built, "make install" and "make test" still
1393     tried to test it.
1395     (b) There were problems when the value of CXX was explicitly set. Some
1396     changes have been made to try to fix these, and ...
1398     (c) --disable-cpp can now be used to explicitly disable C++ support.
1400     (d) The use of @CPP_OBJ@ directly caused a blank line preceded by a
1401     backslash in a target when C++ was disabled. This confuses some
1402     versions of "make", apparently. Using an intermediate variable solves
1403     this. (Same for CPP_LOBJ.)
1405     3. $(LINK_FOR_BUILD) now includes $(CFLAGS_FOR_BUILD) and $(LINK)
1406     (non-Windows) now includes $(CFLAGS) because these flags are sometimes
1407     necessary on certain architectures.
1409     4. Added a setting of -export-symbols-regex to the link command to remove
1410     those symbols that are exported in the C sense, but actually are local
1411     within the library, and not documented. Their names all begin with
1412     "_pcre_". This is not a perfect job, because (a) we have to except some
1413     symbols that pcretest ("illegally") uses, and (b) the facility isn't always
1414     available (and never for static libraries). I have made a note to try to
1415     find a way round (a) in the future.
1418 nigel 81 Version 6.2 01-Aug-05
1419     ---------------------
1421     1. There was no test for integer overflow of quantifier values. A construction
1422     such as {1111111111111111} would give undefined results. What is worse, if
1423     a minimum quantifier for a parenthesized subpattern overflowed and became
1424     negative, the calculation of the memory size went wrong. This could have
1425     led to memory overwriting.
1427     2. Building PCRE using VPATH was broken. Hopefully it is now fixed.
1429     3. Added "b" to the 2nd argument of fopen() in dftables.c, for non-Unix-like
1430     operating environments where this matters.
1432     4. Applied Giuseppe Maxia's patch to add additional features for controlling
1433     PCRE options from within the C++ wrapper.
1435     5. Named capturing subpatterns were not being correctly counted when a pattern
1436     was compiled. This caused two problems: (a) If there were more than 100
1437     such subpatterns, the calculation of the memory needed for the whole
1438     compiled pattern went wrong, leading to an overflow error. (b) Numerical
1439     back references of the form \12, where the number was greater than 9, were
1440     not recognized as back references, even though there were sufficient
1441     previous subpatterns.
1443     6. Two minor patches to pcrecpp.cc in order to allow it to compile on older
1444     versions of gcc, e.g. 2.95.4.
1447 nigel 79 Version 6.1 21-Jun-05
1448     ---------------------
1450     1. There was one reference to the variable "posix" in pcretest.c that was not
1451     surrounded by "#if !defined NOPOSIX".
1453     2. Make it possible to compile pcretest without DFA support, UTF8 support, or
1454     the cross-check on the old pcre_info() function, for the benefit of the
1455     cut-down version of PCRE that is currently imported into Exim.
1457     3. A (silly) pattern starting with (?i)(?-i) caused an internal space
1458     allocation error. I've done the easy fix, which wastes 2 bytes for sensible
1459     patterns that start (?i) but I don't think that matters. The use of (?i) is
1460     just an example; this all applies to the other options as well.
1462     4. Since libtool seems to echo the compile commands it is issuing, the output
1463     from "make" can be reduced a bit by putting "@" in front of each libtool
1464     compile command.
1466     5. Patch from the folks at Google for configure.in to be a bit more thorough
1467     in checking for a suitable C++ installation before trying to compile the
1468     C++ stuff. This should fix a reported problem when a compiler was present,
1469     but no suitable headers.
1471     6. The man pages all had just "PCRE" as their title. I have changed them to
1472     be the relevant file name. I have also arranged that these names are
1473     retained in the file doc/pcre.txt, which is a concatenation in text format
1474     of all the man pages except the little individual ones for each function.
1476     7. The NON-UNIX-USE file had not been updated for the different set of source
1477     files that come with release 6. I also added a few comments about the C++
1478     wrapper.
1481 nigel 77 Version 6.0 07-Jun-05
1482     ---------------------
1484     1. Some minor internal re-organization to help with my DFA experiments.
1486     2. Some missing #ifdef SUPPORT_UCP conditionals in pcretest and printint that
1487     didn't matter for the library itself when fully configured, but did matter
1488     when compiling without UCP support, or within Exim, where the ucp files are
1489     not imported.
1491     3. Refactoring of the library code to split up the various functions into
1492     different source modules. The addition of the new DFA matching code (see
1493     below) to a single monolithic source would have made it really too
1494     unwieldy, quite apart from causing all the code to be include in a
1495     statically linked application, when only some functions are used. This is
1496     relevant even without the DFA addition now that patterns can be compiled in
1497     one application and matched in another.
1499     The downside of splitting up is that there have to be some external
1500     functions and data tables that are used internally in different modules of
1501     the library but which are not part of the API. These have all had their
1502     names changed to start with "_pcre_" so that they are unlikely to clash
1503     with other external names.
1505     4. Added an alternate matching function, pcre_dfa_exec(), which matches using
1506     a different (DFA) algorithm. Although it is slower than the original
1507     function, it does have some advantages for certain types of matching
1508     problem.
1510     5. Upgrades to pcretest in order to test the features of pcre_dfa_exec(),
1511     including restarting after a partial match.
1513     6. A patch for pcregrep that defines INVALID_FILE_ATTRIBUTES if it is not
1514     defined when compiling for Windows was sent to me. I have put it into the
1515     code, though I have no means of testing or verifying it.
1517     7. Added the pcre_refcount() auxiliary function.
1519     8. Added the PCRE_FIRSTLINE option. This constrains an unanchored pattern to
1520     match before or at the first newline in the subject string. In pcretest,
1521     the /f option on a pattern can be used to set this.
1523     9. A repeated \w when used in UTF-8 mode with characters greater than 256
1524     would behave wrongly. This has been present in PCRE since release 4.0.
1526     10. A number of changes to the pcregrep command:
1528     (a) Refactored how -x works; insert ^(...)$ instead of setting
1529     PCRE_ANCHORED and checking the length, in preparation for adding
1530     something similar for -w.
1532     (b) Added the -w (match as a word) option.
1534     (c) Refactored the way lines are read and buffered so as to have more
1535     than one at a time available.
1537     (d) Implemented a pcregrep test script.
1539     (e) Added the -M (multiline match) option. This allows patterns to match
1540     over several lines of the subject. The buffering ensures that at least
1541     8K, or the rest of the document (whichever is the shorter) is available
1542     for matching (and similarly the previous 8K for lookbehind assertions).
1544     (f) Changed the --help output so that it now says
1546     -w, --word-regex(p)
1548     instead of two lines, one with "regex" and the other with "regexp"
1549     because that confused at least one person since the short forms are the
1550     same. (This required a bit of code, as the output is generated
1551     automatically from a table. It wasn't just a text change.)
1553     (g) -- can be used to terminate pcregrep options if the next thing isn't an
1554     option but starts with a hyphen. Could be a pattern or a path name
1555     starting with a hyphen, for instance.
1557     (h) "-" can be given as a file name to represent stdin.
1559     (i) When file names are being printed, "(standard input)" is used for
1560     the standard input, for compatibility with GNU grep. Previously
1561     "<stdin>" was used.
1563     (j) The option --label=xxx can be used to supply a name to be used for
1564     stdin when file names are being printed. There is no short form.
1566     (k) Re-factored the options decoding logic because we are going to add
1567     two more options that take data. Such options can now be given in four
1568     different ways, e.g. "-fname", "-f name", "--file=name", "--file name".
1570     (l) Added the -A, -B, and -C options for requesting that lines of context
1571     around matches be printed.
1573     (m) Added the -L option to print the names of files that do not contain
1574     any matching lines, that is, the complement of -l.
1576     (n) The return code is 2 if any file cannot be opened, but pcregrep does
1577     continue to scan other files.
1579     (o) The -s option was incorrectly implemented. For compatibility with other
1580     greps, it now suppresses the error message for a non-existent or non-
1581     accessible file (but not the return code). There is a new option called
1582     -q that suppresses the output of matching lines, which was what -s was
1583     previously doing.
1585     (p) Added --include and --exclude options to specify files for inclusion
1586     and exclusion when recursing.
1588     11. The Makefile was not using the Autoconf-supported LDFLAGS macro properly.
1589     Hopefully, it now does.
1591     12. Missing cast in pcre_study().
1593     13. Added an "uninstall" target to the makefile.
1595     14. Replaced "extern" in the function prototypes in Makefile.in with
1596     "PCRE_DATA_SCOPE", which defaults to 'extern' or 'extern "C"' in the Unix
1597     world, but is set differently for Windows.
1599     15. Added a second compiling function called pcre_compile2(). The only
1600     difference is that it has an extra argument, which is a pointer to an
1601     integer error code. When there is a compile-time failure, this is set
1602     non-zero, in addition to the error test pointer being set to point to an
1603     error message. The new argument may be NULL if no error number is required
1604     (but then you may as well call pcre_compile(), which is now just a
1605     wrapper). This facility is provided because some applications need a
1606     numeric error indication, but it has also enabled me to tidy up the way
1607     compile-time errors are handled in the POSIX wrapper.
1609     16. Added VPATH=.libs to the makefile; this should help when building with one
1610     prefix path and installing with another. (Or so I'm told by someone who
1611     knows more about this stuff than I do.)
1613     17. Added a new option, REG_DOTALL, to the POSIX function regcomp(). This
1614     passes PCRE_DOTALL to the pcre_compile() function, making the "." character
1615     match everything, including newlines. This is not POSIX-compatible, but
1616     somebody wanted the feature. From pcretest it can be activated by using
1617     both the P and the s flags.
1619     18. AC_PROG_LIBTOOL appeared twice in Makefile.in. Removed one.
1621     19. libpcre.pc was being incorrectly installed as executable.
1623     20. A couple of places in pcretest check for end-of-line by looking for '\n';
1624     it now also looks for '\r' so that it will work unmodified on Windows.
1626     21. Added Google's contributed C++ wrapper to the distribution.
1628     22. Added some untidy missing memory free() calls in pcretest, to keep
1629     Electric Fence happy when testing.
1633 nigel 75 Version 5.0 13-Sep-04
1634     ---------------------
1636     1. Internal change: literal characters are no longer packed up into items
1637     containing multiple characters in a single byte-string. Each character
1638     is now matched using a separate opcode. However, there may be more than one
1639     byte in the character in UTF-8 mode.
1641     2. The pcre_callout_block structure has two new fields: pattern_position and
1642     next_item_length. These contain the offset in the pattern to the next match
1643     item, and its length, respectively.
1645     3. The PCRE_AUTO_CALLOUT option for pcre_compile() requests the automatic
1646     insertion of callouts before each pattern item. Added the /C option to
1647     pcretest to make use of this.
1649     4. On the advice of a Windows user, the lines
1651     #if defined(_WIN32) || defined(WIN32)
1652     _setmode( _fileno( stdout ), 0x8000 );
1653     #endif /* defined(_WIN32) || defined(WIN32) */
1655     have been added to the source of pcretest. This apparently does useful
1656     magic in relation to line terminators.
1658     5. Changed "r" and "w" in the calls to fopen() in pcretest to "rb" and "wb"
1659     for the benefit of those environments where the "b" makes a difference.
1661     6. The icc compiler has the same options as gcc, but "configure" doesn't seem
1662     to know about it. I have put a hack into configure.in that adds in code
1663     to set GCC=yes if CC=icc. This seems to end up at a point in the
1664     generated configure script that is early enough to affect the setting of
1665     compiler options, which is what is needed, but I have no means of testing
1666     whether it really works. (The user who reported this had patched the
1667     generated configure script, which of course I cannot do.)
1669     LATER: After change 22 below (new libtool files), the configure script
1670     seems to know about icc (and also ecc). Therefore, I have commented out
1671     this hack in configure.in.
1673     7. Added support for pkg-config (2 patches were sent in).
1675     8. Negated POSIX character classes that used a combination of internal tables
1676     were completely broken. These were [[:^alpha:]], [[:^alnum:]], and
1677     [[:^ascii]]. Typically, they would match almost any characters. The other
1678     POSIX classes were not broken in this way.
1680     9. Matching the pattern "\b.*?" against "ab cd", starting at offset 1, failed
1681     to find the match, as PCRE was deluded into thinking that the match had to
1682     start at the start point or following a newline. The same bug applied to
1683     patterns with negative forward assertions or any backward assertions
1684     preceding ".*" at the start, unless the pattern required a fixed first
1685     character. This was a failing pattern: "(?!.bcd).*". The bug is now fixed.
1687     10. In UTF-8 mode, when moving forwards in the subject after a failed match
1688     starting at the last subject character, bytes beyond the end of the subject
1689     string were read.
1691     11. Renamed the variable "class" as "classbits" to make life easier for C++
1692     users. (Previously there was a macro definition, but it apparently wasn't
1693     enough.)
1695     12. Added the new field "tables" to the extra data so that tables can be passed
1696     in at exec time, or the internal tables can be re-selected. This allows
1697     a compiled regex to be saved and re-used at a later time by a different
1698     program that might have everything at different addresses.
1700     13. Modified the pcre-config script so that, when run on Solaris, it shows a
1701     -R library as well as a -L library.
1703     14. The debugging options of pcretest (-d on the command line or D on a
1704     pattern) showed incorrect output for anything following an extended class
1705     that contained multibyte characters and which was followed by a quantifier.
1707     15. Added optional support for general category Unicode character properties
1708     via the \p, \P, and \X escapes. Unicode property support implies UTF-8
1709     support. It adds about 90K to the size of the library. The meanings of the
1710     inbuilt class escapes such as \d and \s have NOT been changed.
1712     16. Updated pcredemo.c to include calls to free() to release the memory for the
1713     compiled pattern.
1715     17. The generated file chartables.c was being created in the source directory
1716     instead of in the building directory. This caused the build to fail if the
1717     source directory was different from the building directory, and was
1718     read-only.
1720     18. Added some sample Win commands from Mark Tetrode into the NON-UNIX-USE
1721     file. No doubt somebody will tell me if they don't make sense... Also added
1722     Dan Mooney's comments about building on OpenVMS.
1724     19. Added support for partial matching via the PCRE_PARTIAL option for
1725     pcre_exec() and the \P data escape in pcretest.
1727     20. Extended pcretest with 3 new pattern features:
1729     (i) A pattern option of the form ">rest-of-line" causes pcretest to
1730     write the compiled pattern to the file whose name is "rest-of-line".
1731     This is a straight binary dump of the data, with the saved pointer to
1732     the character tables forced to be NULL. The study data, if any, is
1733     written too. After writing, pcretest reads a new pattern.
1735     (ii) If, instead of a pattern, "<rest-of-line" is given, pcretest reads a
1736     compiled pattern from the given file. There must not be any
1737     occurrences of "<" in the file name (pretty unlikely); if there are,
1738     pcretest will instead treat the initial "<" as a pattern delimiter.
1739     After reading in the pattern, pcretest goes on to read data lines as
1740     usual.
1742     (iii) The F pattern option causes pcretest to flip the bytes in the 32-bit
1743     and 16-bit fields in a compiled pattern, to simulate a pattern that
1744     was compiled on a host of opposite endianness.
1746     21. The pcre-exec() function can now cope with patterns that were compiled on
1747     hosts of opposite endianness, with this restriction:
1749     As for any compiled expression that is saved and used later, the tables
1750     pointer field cannot be preserved; the extra_data field in the arguments
1751     to pcre_exec() should be used to pass in a tables address if a value
1752     other than the default internal tables were used at compile time.
1754     22. Calling pcre_exec() with a negative value of the "ovecsize" parameter is
1755     now diagnosed as an error. Previously, most of the time, a negative number
1756     would have been treated as zero, but if in addition "ovector" was passed as
1757     NULL, a crash could occur.
1759     23. Updated the files ltmain.sh, config.sub, config.guess, and aclocal.m4 with
1760     new versions from the libtool 1.5 distribution (the last one is a copy of
1761     a file called libtool.m4). This seems to have fixed the need to patch
1762     "configure" to support Darwin 1.3 (which I used to do). However, I still
1763     had to patch ltmain.sh to ensure that ${SED} is set (it isn't on my
1764     workstation).
1766     24. Changed the PCRE licence to be the more standard "BSD" licence.
1769 nigel 73 Version 4.5 01-Dec-03
1770     ---------------------
1772     1. There has been some re-arrangement of the code for the match() function so
1773     that it can be compiled in a version that does not call itself recursively.
1774     Instead, it keeps those local variables that need separate instances for
1775     each "recursion" in a frame on the heap, and gets/frees frames whenever it
1776     needs to "recurse". Keeping track of where control must go is done by means
1777     of setjmp/longjmp. The whole thing is implemented by a set of macros that
1778     hide most of the details from the main code, and operates only if
1779     NO_RECURSE is defined while compiling pcre.c. If PCRE is built using the
1780     "configure" mechanism, "--disable-stack-for-recursion" turns on this way of
1781     operating.
1783     To make it easier for callers to provide specially tailored get/free
1784     functions for this usage, two new functions, pcre_stack_malloc, and
1785     pcre_stack_free, are used. They are always called in strict stacking order,
1786     and the size of block requested is always the same.
1788     The PCRE_CONFIG_STACKRECURSE info parameter can be used to find out whether
1789     PCRE has been compiled to use the stack or the heap for recursion. The
1790     -C option of pcretest uses this to show which version is compiled.
1792     A new data escape \S, is added to pcretest; it causes the amounts of store
1793     obtained and freed by both kinds of malloc/free at match time to be added
1794     to the output.
1796     2. Changed the locale test to use "fr_FR" instead of "fr" because that's
1797     what's available on my current Linux desktop machine.
1799     3. When matching a UTF-8 string, the test for a valid string at the start has
1800     been extended. If start_offset is not zero, PCRE now checks that it points
1801     to a byte that is the start of a UTF-8 character. If not, it returns
1802     PCRE_ERROR_BADUTF8_OFFSET (-11). Note: the whole string is still checked;
1803     this is necessary because there may be backward assertions in the pattern.
1804     When matching the same subject several times, it may save resources to use
1805     PCRE_NO_UTF8_CHECK on all but the first call if the string is long.
1807     4. The code for checking the validity of UTF-8 strings has been tightened so
1808     that it rejects (a) strings containing 0xfe or 0xff bytes and (b) strings
1809     containing "overlong sequences".
1811     5. Fixed a bug (appearing twice) that I could not find any way of exploiting!
1812     I had written "if ((digitab[*p++] && chtab_digit) == 0)" where the "&&"
1813     should have been "&", but it just so happened that all the cases this let
1814     through by mistake were picked up later in the function.
1816     6. I had used a variable called "isblank" - this is a C99 function, causing
1817     some compilers to warn. To avoid this, I renamed it (as "blankclass").
1819     7. Cosmetic: (a) only output another newline at the end of pcretest if it is
1820     prompting; (b) run "./pcretest /dev/null" at the start of the test script
1821     so the version is shown; (c) stop "make test" echoing "./RunTest".
1823     8. Added patches from David Burgess to enable PCRE to run on EBCDIC systems.
1825     9. The prototype for memmove() for systems that don't have it was using
1826     size_t, but the inclusion of the header that defines size_t was later. I've
1827     moved the #includes for the C headers earlier to avoid this.
1829     10. Added some adjustments to the code to make it easier to compiler on certain
1830     special systems:
1832     (a) Some "const" qualifiers were missing.
1833     (b) Added the macro EXPORT before all exported functions; by default this
1834     is defined to be empty.
1835     (c) Changed the dftables auxiliary program (that builds chartables.c) so
1836     that it reads its output file name as an argument instead of writing
1837     to the standard output and assuming this can be redirected.
1839     11. In UTF-8 mode, if a recursive reference (e.g. (?1)) followed a character
1840     class containing characters with values greater than 255, PCRE compilation
1841     went into a loop.
1843     12. A recursive reference to a subpattern that was within another subpattern
1844     that had a minimum quantifier of zero caused PCRE to crash. For example,
1845     (x(y(?2))z)? provoked this bug with a subject that got as far as the
1846     recursion. If the recursively-called subpattern itself had a zero repeat,
1847     that was OK.
1849     13. In pcretest, the buffer for reading a data line was set at 30K, but the
1850     buffer into which it was copied (for escape processing) was still set at
1851     1024, so long lines caused crashes.
1853     14. A pattern such as /[ab]{1,3}+/ failed to compile, giving the error
1854     "internal error: code overflow...". This applied to any character class
1855     that was followed by a possessive quantifier.
1857     15. Modified the Makefile to add libpcre.la as a prerequisite for
1858     libpcreposix.la because I was told this is needed for a parallel build to
1859     work.
1861     16. If a pattern that contained .* following optional items at the start was
1862     studied, the wrong optimizing data was generated, leading to matching
1863     errors. For example, studying /[ab]*.*c/ concluded, erroneously, that any
1864     matching string must start with a or b or c. The correct conclusion for
1865     this pattern is that a match can start with any character.
1868 nigel 71 Version 4.4 13-Aug-03
1869     ---------------------
1871     1. In UTF-8 mode, a character class containing characters with values between
1872     127 and 255 was not handled correctly if the compiled pattern was studied.
1873     In fixing this, I have also improved the studying algorithm for such
1874     classes (slightly).
1876     2. Three internal functions had redundant arguments passed to them. Removal
1877     might give a very teeny performance improvement.
1879     3. Documentation bug: the value of the capture_top field in a callout is *one
1880     more than* the number of the hightest numbered captured substring.
1882     4. The Makefile linked pcretest and pcregrep with -lpcre, which could result
1883     in incorrectly linking with a previously installed version. They now link
1884     explicitly with libpcre.la.
1886     5. configure.in no longer needs to recognize Cygwin specially.
1888     6. A problem in pcre.in for Windows platforms is fixed.
1890     7. If a pattern was successfully studied, and the -d (or /D) flag was given to
1891     pcretest, it used to include the size of the study block as part of its
1892     output. Unfortunately, the structure contains a field that has a different
1893     size on different hardware architectures. This meant that the tests that
1894     showed this size failed. As the block is currently always of a fixed size,
1895     this information isn't actually particularly useful in pcretest output, so
1896     I have just removed it.
1898     8. Three pre-processor statements accidentally did not start in column 1.
1899     Sadly, there are *still* compilers around that complain, even though
1900     standard C has not required this for well over a decade. Sigh.
1902     9. In pcretest, the code for checking callouts passed small integers in the
1903     callout_data field, which is a void * field. However, some picky compilers
1904     complained about the casts involved for this on 64-bit systems. Now
1905     pcretest passes the address of the small integer instead, which should get
1906     rid of the warnings.
1908     10. By default, when in UTF-8 mode, PCRE now checks for valid UTF-8 strings at
1909     both compile and run time, and gives an error if an invalid UTF-8 sequence
1910     is found. There is a option for disabling this check in cases where the
1911     string is known to be correct and/or the maximum performance is wanted.
1913     11. In response to a bug report, I changed one line in Makefile.in from
1915     -Wl,--out-implib,.libs/lib@WIN_PREFIX@pcreposix.dll.a \
1916     to
1917     -Wl,--out-implib,.libs/@WIN_PREFIX@libpcreposix.dll.a \
1919     to look similar to other lines, but I have no way of telling whether this
1920     is the right thing to do, as I do not use Windows. No doubt I'll get told
1921     if it's wrong...
1924 nigel 69 Version 4.3 21-May-03
1925     ---------------------
1927     1. Two instances of @WIN_PREFIX@ omitted from the Windows targets in the
1928     Makefile.
1930     2. Some refactoring to improve the quality of the code:
1932     (i) The utf8_table... variables are now declared "const".
1934     (ii) The code for \cx, which used the "case flipping" table to upper case
1935     lower case letters, now just substracts 32. This is ASCII-specific,
1936     but the whole concept of \cx is ASCII-specific, so it seems
1937     reasonable.
1939     (iii) PCRE was using its character types table to recognize decimal and
1940     hexadecimal digits in the pattern. This is silly, because it handles
1941     only 0-9, a-f, and A-F, but the character types table is locale-
1942     specific, which means strange things might happen. A private
1943     table is now used for this - though it costs 256 bytes, a table is
1944     much faster than multiple explicit tests. Of course, the standard
1945     character types table is still used for matching digits in subject
1946     strings against \d.
1948     (iv) Strictly, the identifier ESC_t is reserved by POSIX (all identifiers
1949     ending in _t are). So I've renamed it as ESC_tee.
1951     3. The first argument for regexec() in the POSIX wrapper should have been
1952     defined as "const".
1954     4. Changed pcretest to use malloc() for its buffers so that they can be
1955     Electric Fenced for debugging.
1957     5. There were several places in the code where, in UTF-8 mode, PCRE would try
1958     to read one or more bytes before the start of the subject string. Often this
1959     had no effect on PCRE's behaviour, but in some circumstances it could
1960     provoke a segmentation fault.
1962     6. A lookbehind at the start of a pattern in UTF-8 mode could also cause PCRE
1963     to try to read one or more bytes before the start of the subject string.
1965     7. A lookbehind in a pattern matched in non-UTF-8 mode on a PCRE compiled with
1966     UTF-8 support could misbehave in various ways if the subject string
1967     contained bytes with the 0x80 bit set and the 0x40 bit unset in a lookbehind
1968     area. (PCRE was not checking for the UTF-8 mode flag, and trying to move
1969     back over UTF-8 characters.)
1972 nigel 67 Version 4.2 14-Apr-03
1973     ---------------------
1975     1. Typo "#if SUPPORT_UTF8" instead of "#ifdef SUPPORT_UTF8" fixed.
1977     2. Changes to the building process, supplied by Ronald Landheer-Cieslak
1978     [ON_WINDOWS]: new variable, "#" on non-Windows platforms
1979     [NOT_ON_WINDOWS]: new variable, "#" on Windows platforms
1980     [WIN_PREFIX]: new variable, "cyg" for Cygwin
1981     * Makefile.in: use autoconf substitution for OBJEXT, EXEEXT, BUILD_OBJEXT
1982     and BUILD_EXEEXT
1983     Note: automatic setting of the BUILD variables is not yet working
1984     set CPPFLAGS and BUILD_CPPFLAGS (but don't use yet) - should be used at
1985     compile-time but not at link-time
1986     [LINK]: use for linking executables only
1987     make different versions for Windows and non-Windows
1988     [LINKLIB]: new variable, copy of UNIX-style LINK, used for linking
1989     libraries
1990     [LINK_FOR_BUILD]: new variable
1991     [OBJEXT]: use throughout
1992     [EXEEXT]: use throughout
1993     <winshared>: new target
1994     <wininstall>: new target
1995     <dftables.o>: use native compiler
1996     <dftables>: use native linker
1997     <install>: handle Windows platform correctly
1998     <clean>: ditto
1999     <check>: ditto
2000     copy DLL to top builddir before testing
2002     As part of these changes, -no-undefined was removed again. This was reported
2003     to give trouble on HP-UX 11.0, so getting rid of it seems like a good idea
2004     in any case.
2006     3. Some tidies to get rid of compiler warnings:
2008     . In the match_data structure, match_limit was an unsigned long int, whereas
2009     match_call_count was an int. I've made them both unsigned long ints.
2011     . In pcretest the fact that a const uschar * doesn't automatically cast to
2012     a void * provoked a warning.
2014     . Turning on some more compiler warnings threw up some "shadow" variables
2015     and a few more missing casts.
2017     4. If PCRE was complied with UTF-8 support, but called without the PCRE_UTF8
2018     option, a class that contained a single character with a value between 128
2019     and 255 (e.g. /[\xFF]/) caused PCRE to crash.
2021     5. If PCRE was compiled with UTF-8 support, but called without the PCRE_UTF8
2022     option, a class that contained several characters, but with at least one
2023     whose value was between 128 and 255 caused PCRE to crash.
2026 nigel 65 Version 4.1 12-Mar-03
2027     ---------------------
2028 nigel 63
2029 nigel 65 1. Compiling with gcc -pedantic found a couple of places where casts were
2030     needed, and a string in dftables.c that was longer than standard compilers are
2031     required to support.
2033     2. Compiling with Sun's compiler found a few more places where the code could
2034     be tidied up in order to avoid warnings.
2036     3. The variables for cross-compiling were called HOST_CC and HOST_CFLAGS; the
2037     first of these names is deprecated in the latest Autoconf in favour of the name
2038     CC_FOR_BUILD, because "host" is typically used to mean the system on which the
2039     compiled code will be run. I can't find a reference for HOST_CFLAGS, but by
2040     analogy I have changed it to CFLAGS_FOR_BUILD.
2042     4. Added -no-undefined to the linking command in the Makefile, because this is
2043     apparently helpful for Windows. To make it work, also added "-L. -lpcre" to the
2044     linking step for the pcreposix library.
2046     5. PCRE was failing to diagnose the case of two named groups with the same
2047     name.
2049     6. A problem with one of PCRE's optimizations was discovered. PCRE remembers a
2050     literal character that is needed in the subject for a match, and scans along to
2051     ensure that it is present before embarking on the full matching process. This
2052     saves time in cases of nested unlimited repeats that are never going to match.
2053     Problem: the scan can take a lot of time if the subject is very long (e.g.
2054     megabytes), thus penalizing straightforward matches. It is now done only if the
2055     amount of subject to be scanned is less than 1000 bytes.
2057     7. A lesser problem with the same optimization is that it was recording the
2058     first character of an anchored pattern as "needed", thus provoking a search
2059     right along the subject, even when the first match of the pattern was going to
2060     fail. The "needed" character is now not set for anchored patterns, unless it
2061     follows something in the pattern that is of non-fixed length. Thus, it still
2062     fulfils its original purpose of finding quick non-matches in cases of nested
2063     unlimited repeats, but isn't used for simple anchored patterns such as /^abc/.
2066     Version 4.0 17-Feb-03
2067     ---------------------
2069 nigel 63 1. If a comment in an extended regex that started immediately after a meta-item
2070     extended to the end of string, PCRE compiled incorrect data. This could lead to
2071     all kinds of weird effects. Example: /#/ was bad; /()#/ was bad; /a#/ was not.
2073     2. Moved to autoconf 2.53 and libtool 1.4.2.
2075     3. Perl 5.8 no longer needs "use utf8" for doing UTF-8 things. Consequently,
2076     the special perltest8 script is no longer needed - all the tests can be run
2077     from a single perltest script.
2079     4. From 5.004, Perl has not included the VT character (0x0b) in the set defined
2080     by \s. It has now been removed in PCRE. This means it isn't recognized as
2081     whitespace in /x regexes too, which is the same as Perl. Note that the POSIX
2082     class [:space:] *does* include VT, thereby creating a mess.
2084     5. Added the class [:blank:] (a GNU extension from Perl 5.8) to match only
2085     space and tab.
2087     6. Perl 5.005 was a long time ago. It's time to amalgamate the tests that use
2088     its new features into the main test script, reducing the number of scripts.
2090     7. Perl 5.8 has changed the meaning of patterns like /a(?i)b/. Earlier versions
2091     were backward compatible, and made the (?i) apply to the whole pattern, as if
2092     /i were given. Now it behaves more logically, and applies the option setting
2093     only to what follows. PCRE has been changed to follow suit. However, if it
2094     finds options settings right at the start of the pattern, it extracts them into
2095     the global options, as before. Thus, they show up in the info data.
2097     8. Added support for the \Q...\E escape sequence. Characters in between are
2098     treated as literals. This is slightly different from Perl in that $ and @ are
2099     also handled as literals inside the quotes. In Perl, they will cause variable
2100     interpolation. Note the following examples:
2102     Pattern PCRE matches Perl matches
2104     \Qabc$xyz\E abc$xyz abc followed by the contents of $xyz
2105     \Qabc\$xyz\E abc\$xyz abc\$xyz
2106     \Qabc\E\$\Qxyz\E abc$xyz abc$xyz
2108     For compatibility with Perl, \Q...\E sequences are recognized inside character
2109     classes as well as outside them.
2111     9. Re-organized 3 code statements in pcretest to avoid "overflow in
2112     floating-point constant arithmetic" warnings from a Microsoft compiler. Added a
2113     (size_t) cast to one statement in pcretest and one in pcreposix to avoid
2114     signed/unsigned warnings.
2116     10. SunOS4 doesn't have strtoul(). This was used only for unpicking the -o
2117     option for pcretest, so I've replaced it by a simple function that does just
2118     that job.
2120     11. pcregrep was ending with code 0 instead of 2 for the commands "pcregrep" or
2121     "pcregrep -".
2123     12. Added "possessive quantifiers" ?+, *+, ++, and {,}+ which come from Sun's
2124     Java package. This provides some syntactic sugar for simple cases of what my
2125     documentation calls "once-only subpatterns". A pattern such as x*+ is the same
2126     as (?>x*). In other words, if what is inside (?>...) is just a single repeated
2127     item, you can use this simplified notation. Note that only makes sense with
2128     greedy quantifiers. Consequently, the use of the possessive quantifier forces
2129     greediness, whatever the setting of the PCRE_UNGREEDY option.
2131     13. A change of greediness default within a pattern was not taking effect at
2132     the current level for patterns like /(b+(?U)a+)/. It did apply to parenthesized
2133     subpatterns that followed. Patterns like /b+(?U)a+/ worked because the option
2134     was abstracted outside.
2136     14. PCRE now supports the \G assertion. It is true when the current matching
2137     position is at the start point of the match. This differs from \A when the
2138     starting offset is non-zero. Used with the /g option of pcretest (or similar
2139     code), it works in the same way as it does for Perl's /g option. If all
2140     alternatives of a regex begin with \G, the expression is anchored to the start
2141     match position, and the "anchored" flag is set in the compiled expression.
2143     15. Some bugs concerning the handling of certain option changes within patterns
2144     have been fixed. These applied to options other than (?ims). For example,
2145     "a(?x: b c )d" did not match "XabcdY" but did match "Xa b c dY". It should have
2146     been the other way round. Some of this was related to change 7 above.
2148     16. PCRE now gives errors for /[.x.]/ and /[=x=]/ as unsupported POSIX
2149     features, as Perl does. Previously, PCRE gave the warnings only for /[[.x.]]/
2150     and /[[=x=]]/. PCRE now also gives an error for /[:name:]/ because it supports
2151     POSIX classes only within a class (e.g. /[[:alpha:]]/).
2153     17. Added support for Perl's \C escape. This matches one byte, even in UTF8
2154     mode. Unlike ".", it always matches newline, whatever the setting of
2155     PCRE_DOTALL. However, PCRE does not permit \C to appear in lookbehind
2156     assertions. Perl allows it, but it doesn't (in general) work because it can't
2157     calculate the length of the lookbehind. At least, that's the case for Perl
2158     5.8.0 - I've been told they are going to document that it doesn't work in
2159     future.
2161     18. Added an error diagnosis for escapes that PCRE does not support: these are
2162     \L, \l, \N, \P, \p, \U, \u, and \X.
2164     19. Although correctly diagnosing a missing ']' in a character class, PCRE was
2165     reading past the end of the pattern in cases such as /[abcd/.
2167     20. PCRE was getting more memory than necessary for patterns with classes that
2168     contained both POSIX named classes and other characters, e.g. /[[:space:]abc/.
2170     21. Added some code, conditional on #ifdef VPCOMPAT, to make life easier for
2171     compiling PCRE for use with Virtual Pascal.
2173     22. Small fix to the Makefile to make it work properly if the build is done
2174     outside the source tree.
2176     23. Added a new extension: a condition to go with recursion. If a conditional
2177     subpattern starts with (?(R) the "true" branch is used if recursion has
2178     happened, whereas the "false" branch is used only at the top level.
2180     24. When there was a very long string of literal characters (over 255 bytes
2181     without UTF support, over 250 bytes with UTF support), the computation of how
2182     much memory was required could be incorrect, leading to segfaults or other
2183     strange effects.
2185     25. PCRE was incorrectly assuming anchoring (either to start of subject or to
2186     start of line for a non-DOTALL pattern) when a pattern started with (.*) and
2187     there was a subsequent back reference to those brackets. This meant that, for
2188     example, /(.*)\d+\1/ failed to match "abc123bc". Unfortunately, it isn't
2189     possible to check for precisely this case. All we can do is abandon the
2190     optimization if .* occurs inside capturing brackets when there are any back
2191     references whatsoever. (See below for a better fix that came later.)
2193     26. The handling of the optimization for finding the first character of a
2194     non-anchored pattern, and for finding a character that is required later in the
2195     match were failing in some cases. This didn't break the matching; it just
2196     failed to optimize when it could. The way this is done has been re-implemented.
2198     27. Fixed typo in error message for invalid (?R item (it said "(?p").
2200     28. Added a new feature that provides some of the functionality that Perl
2201     provides with (?{...}). The facility is termed a "callout". The way it is done
2202     in PCRE is for the caller to provide an optional function, by setting
2203     pcre_callout to its entry point. Like pcre_malloc and pcre_free, this is a
2204     global variable. By default it is unset, which disables all calling out. To get
2205     the function called, the regex must include (?C) at appropriate points. This
2206     is, in fact, equivalent to (?C0), and any number <= 255 may be given with (?C).
2207     This provides a means of identifying different callout points. When PCRE
2208     reaches such a point in the regex, if pcre_callout has been set, the external
2209     function is called. It is provided with data in a structure called
2210     pcre_callout_block, which is defined in pcre.h. If the function returns 0,
2211     matching continues; if it returns a non-zero value, the match at the current
2212     point fails. However, backtracking will occur if possible. [This was changed
2213     later and other features added - see item 49 below.]
2215     29. pcretest is upgraded to test the callout functionality. It provides a
2216     callout function that displays information. By default, it shows the start of
2217     the match and the current position in the text. There are some new data escapes
2218     to vary what happens:
2220     \C+ in addition, show current contents of captured substrings
2221     \C- do not supply a callout function
2222     \C!n return 1 when callout number n is reached
2223     \C!n!m return 1 when callout number n is reached for the mth time
2225     30. If pcregrep was called with the -l option and just a single file name, it
2226     output "<stdin>" if a match was found, instead of the file name.
2228     31. Improve the efficiency of the POSIX API to PCRE. If the number of capturing
2229     slots is less than POSIX_MALLOC_THRESHOLD, use a block on the stack to pass to
2230     pcre_exec(). This saves a malloc/free per call. The default value of
2231     POSIX_MALLOC_THRESHOLD is 10; it can be changed by --with-posix-malloc-threshold
2232     when configuring.
2234     32. The default maximum size of a compiled pattern is 64K. There have been a
2235     few cases of people hitting this limit. The code now uses macros to handle the
2236     storing of links as offsets within the compiled pattern. It defaults to 2-byte
2237     links, but this can be changed to 3 or 4 bytes by --with-link-size when
2238     configuring. Tests 2 and 5 work only with 2-byte links because they output
2239     debugging information about compiled patterns.
2241     33. Internal code re-arrangements:
2243     (a) Moved the debugging function for printing out a compiled regex into
2244     its own source file (printint.c) and used #include to pull it into
2245     pcretest.c and, when DEBUG is defined, into pcre.c, instead of having two
2246     separate copies.
2248     (b) Defined the list of op-code names for debugging as a macro in
2249     internal.h so that it is next to the definition of the opcodes.
2251     (c) Defined a table of op-code lengths for simpler skipping along compiled
2252     code. This is again a macro in internal.h so that it is next to the
2253     definition of the opcodes.
2255     34. Added support for recursive calls to individual subpatterns, along the
2256     lines of Robin Houston's patch (but implemented somewhat differently).
2258     35. Further mods to the Makefile to help Win32. Also, added code to pcregrep to
2259     allow it to read and process whole directories in Win32. This code was
2260     contributed by Lionel Fourquaux; it has not been tested by me.
2262     36. Added support for named subpatterns. The Python syntax (?P<name>...) is
2263     used to name a group. Names consist of alphanumerics and underscores, and must
2264     be unique. Back references use the syntax (?P=name) and recursive calls use
2265     (?P>name) which is a PCRE extension to the Python extension. Groups still have
2266     numbers. The function pcre_fullinfo() can be used after compilation to extract
2267     a name/number map. There are three relevant calls:
2269     PCRE_INFO_NAMEENTRYSIZE yields the size of each entry in the map
2270     PCRE_INFO_NAMECOUNT yields the number of entries
2271     PCRE_INFO_NAMETABLE yields a pointer to the map.
2273     The map is a vector of fixed-size entries. The size of each entry depends on
2274     the length of the longest name used. The first two bytes of each entry are the
2275     group number, most significant byte first. There follows the corresponding
2276     name, zero terminated. The names are in alphabetical order.
2278     37. Make the maximum literal string in the compiled code 250 for the non-UTF-8
2279     case instead of 255. Making it the same both with and without UTF-8 support
2280     means that the same test output works with both.
2282     38. There was a case of malloc(0) in the POSIX testing code in pcretest. Avoid
2283     calling malloc() with a zero argument.
2285     39. Change 25 above had to resort to a heavy-handed test for the .* anchoring
2286     optimization. I've improved things by keeping a bitmap of backreferences with
2287     numbers 1-31 so that if .* occurs inside capturing brackets that are not in
2288     fact referenced, the optimization can be applied. It is unlikely that a
2289     relevant occurrence of .* (i.e. one which might indicate anchoring or forcing
2290     the match to follow \n) will appear inside brackets with a number greater than
2291     31, but if it does, any back reference > 31 suppresses the optimization.
2293     40. Added a new compile-time option PCRE_NO_AUTO_CAPTURE. This has the effect
2294     of disabling numbered capturing parentheses. Any opening parenthesis that is
2295     not followed by ? behaves as if it were followed by ?: but named parentheses
2296     can still be used for capturing (and they will acquire numbers in the usual
2297     way).
2299     41. Redesigned the return codes from the match() function into yes/no/error so
2300     that errors can be passed back from deep inside the nested calls. A malloc
2301     failure while inside a recursive subpattern call now causes the
2302     PCRE_ERROR_NOMEMORY return instead of quietly going wrong.
2304     42. It is now possible to set a limit on the number of times the match()
2305     function is called in a call to pcre_exec(). This facility makes it possible to
2306     limit the amount of recursion and backtracking, though not in a directly
2307     obvious way, because the match() function is used in a number of different
2308     circumstances. The count starts from zero for each position in the subject
2309     string (for non-anchored patterns). The default limit is, for compatibility, a
2310     large number, namely 10 000 000. You can change this in two ways:
2312     (a) When configuring PCRE before making, you can use --with-match-limit=n
2313     to set a default value for the compiled library.
2315     (b) For each call to pcre_exec(), you can pass a pcre_extra block in which
2316     a different value is set. See 45 below.
2318     If the limit is exceeded, pcre_exec() returns PCRE_ERROR_MATCHLIMIT.
2320     43. Added a new function pcre_config(int, void *) to enable run-time extraction
2321     of things that can be changed at compile time. The first argument specifies
2322     what is wanted and the second points to where the information is to be placed.
2323     The current list of available information is:
2327     The output is an integer that is set to one if UTF-8 support is available;
2328     otherwise it is set to zero.
2332     The output is an integer that it set to the value of the code that is used for
2333     newline. It is either LF (10) or CR (13).
2337     The output is an integer that contains the number of bytes used for internal
2338     linkage in compiled expressions. The value is 2, 3, or 4. See item 32 above.
2342     The output is an integer that contains the threshold above which the POSIX
2343     interface uses malloc() for output vectors. See item 31 above.
2347     The output is an unsigned integer that contains the default limit of the number
2348     of match() calls in a pcre_exec() execution. See 42 above.
2350     44. pcretest has been upgraded by the addition of the -C option. This causes it
2351     to extract all the available output from the new pcre_config() function, and to
2352     output it. The program then exits immediately.
2354     45. A need has arisen to pass over additional data with calls to pcre_exec() in
2355     order to support additional features. One way would have been to define
2356     pcre_exec2() (for example) with extra arguments, but this would not have been
2357     extensible, and would also have required all calls to the original function to
2358     be mapped to the new one. Instead, I have chosen to extend the mechanism that
2359     is used for passing in "extra" data from pcre_study().
2361     The pcre_extra structure is now exposed and defined in pcre.h. It currently
2362     contains the following fields:
2364     flags a bitmap indicating which of the following fields are set
2365     study_data opaque data from pcre_study()
2366     match_limit a way of specifying a limit on match() calls for a specific
2367     call to pcre_exec()
2368     callout_data data for callouts (see 49 below)
2370     The flag bits are also defined in pcre.h, and are
2376     The pcre_study() function now returns one of these new pcre_extra blocks, with
2377     the actual study data pointed to by the study_data field, and the
2378     PCRE_EXTRA_STUDY_DATA flag set. This can be passed directly to pcre_exec() as
2379     before. That is, this change is entirely upwards-compatible and requires no
2380     change to existing code.
2382     If you want to pass in additional data to pcre_exec(), you can either place it
2383     in a pcre_extra block provided by pcre_study(), or create your own pcre_extra
2384     block.
2386     46. pcretest has been extended to test the PCRE_EXTRA_MATCH_LIMIT feature. If a
2387     data string contains the escape sequence \M, pcretest calls pcre_exec() several
2388     times with different match limits, until it finds the minimum value needed for
2389     pcre_exec() to complete. The value is then output. This can be instructive; for
2390     most simple matches the number is quite small, but for pathological cases it
2391     gets very large very quickly.
2393     47. There's a new option for pcre_fullinfo() called PCRE_INFO_STUDYSIZE. It
2394     returns the size of the data block pointed to by the study_data field in a
2395     pcre_extra block, that is, the value that was passed as the argument to
2396     pcre_malloc() when PCRE was getting memory in which to place the information
2397     created by pcre_study(). The fourth argument should point to a size_t variable.
2398     pcretest has been extended so that this information is shown after a successful
2399     pcre_study() call when information about the compiled regex is being displayed.
2401     48. Cosmetic change to Makefile: there's no need to have / after $(DESTDIR)
2402     because what follows is always an absolute path. (Later: it turns out that this
2403     is more than cosmetic for MinGW, because it doesn't like empty path
2404     components.)
2406     49. Some changes have been made to the callout feature (see 28 above):
2408     (i) A callout function now has three choices for what it returns:
2410     0 => success, carry on matching
2411     > 0 => failure at this point, but backtrack if possible
2412     < 0 => serious error, return this value from pcre_exec()
2414     Negative values should normally be chosen from the set of PCRE_ERROR_xxx
2415     values. In particular, returning PCRE_ERROR_NOMATCH forces a standard
2416     "match failed" error. The error number PCRE_ERROR_CALLOUT is reserved for
2417     use by callout functions. It will never be used by PCRE itself.
2419     (ii) The pcre_extra structure (see 45 above) has a void * field called
2420     callout_data, with corresponding flag bit PCRE_EXTRA_CALLOUT_DATA. The
2421     pcre_callout_block structure has a field of the same name. The contents of
2422     the field passed in the pcre_extra structure are passed to the callout
2423     function in the corresponding field in the callout block. This makes it
2424     easier to use the same callout-containing regex from multiple threads. For
2425     testing, the pcretest program has a new data escape
2427     \C*n pass the number n (may be negative) as callout_data
2429     If the callout function in pcretest receives a non-zero value as
2430     callout_data, it returns that value.
2432     50. Makefile wasn't handling CFLAGS properly when compiling dftables. Also,
2433     there were some redundant $(CFLAGS) in commands that are now specified as
2434     $(LINK), which already includes $(CFLAGS).
2436     51. Extensions to UTF-8 support are listed below. These all apply when (a) PCRE
2437     has been compiled with UTF-8 support *and* pcre_compile() has been compiled
2438     with the PCRE_UTF8 flag. Patterns that are compiled without that flag assume
2439     one-byte characters throughout. Note that case-insensitive matching applies
2440     only to characters whose values are less than 256. PCRE doesn't support the
2441     notion of cases for higher-valued characters.
2443     (i) A character class whose characters are all within 0-255 is handled as
2444     a bit map, and the map is inverted for negative classes. Previously, a
2445     character > 255 always failed to match such a class; however it should
2446     match if the class was a negative one (e.g. [^ab]). This has been fixed.
2448     (ii) A negated character class with a single character < 255 is coded as
2449     "not this character" (OP_NOT). This wasn't working properly when the test
2450     character was multibyte, either singly or repeated.
2452     (iii) Repeats of multibyte characters are now handled correctly in UTF-8
2453     mode, for example: \x{100}{2,3}.
2455     (iv) The character escapes \b, \B, \d, \D, \s, \S, \w, and \W (either
2456     singly or repeated) now correctly test multibyte characters. However,
2457     PCRE doesn't recognize any characters with values greater than 255 as
2458     digits, spaces, or word characters. Such characters always match \D, \S,
2459     and \W, and never match \d, \s, or \w.
2461     (v) Classes may now contain characters and character ranges with values
2462     greater than 255. For example: [ab\x{100}-\x{400}].
2464     (vi) pcregrep now has a --utf-8 option (synonym -u) which makes it call
2465     PCRE in UTF-8 mode.
2467     52. The info request value PCRE_INFO_FIRSTCHAR has been renamed
2468     PCRE_INFO_FIRSTBYTE because it is a byte value. However, the old name is
2469     retained for backwards compatibility. (Note that LASTLITERAL is also a byte
2470     value.)
2472     53. The single man page has become too large. I have therefore split it up into
2473     a number of separate man pages. These also give rise to individual HTML pages;
2474     these are now put in a separate directory, and there is an index.html page that
2475     lists them all. Some hyperlinking between the pages has been installed.
2477     54. Added convenience functions for handling named capturing parentheses.
2479     55. Unknown escapes inside character classes (e.g. [\M]) and escapes that
2480     aren't interpreted therein (e.g. [\C]) are literals in Perl. This is now also
2481     true in PCRE, except when the PCRE_EXTENDED option is set, in which case they
2482     are faulted.
2484     56. Introduced HOST_CC and HOST_CFLAGS which can be set in the environment when
2485     calling configure. These values are used when compiling the dftables.c program
2486     which is run to generate the source of the default character tables. They
2487     default to the values of CC and CFLAGS. If you are cross-compiling PCRE,
2488     you will need to set these values.
2490     57. Updated the building process for Windows DLL, as provided by Fred Cox.
2493     Version 3.9 02-Jan-02
2494 nigel 61 ---------------------
2496     1. A bit of extraneous text had somehow crept into the pcregrep documentation.
2498     2. If --disable-static was given, the building process failed when trying to
2499     build pcretest and pcregrep. (For some reason it was using libtool to compile
2500     them, which is not right, as they aren't part of the library.)
2503 nigel 59 Version 3.8 18-Dec-01
2504     ---------------------
2506     1. The experimental UTF-8 code was completely screwed up. It was packing the
2507     bytes in the wrong order. How dumb can you get?
2510 nigel 57 Version 3.7 29-Oct-01
2511     ---------------------
2513     1. In updating pcretest to check change 1 of version 3.6, I screwed up.
2514     This caused pcretest, when used on the test data, to segfault. Unfortunately,
2515     this didn't happen under Solaris 8, where I normally test things.
2517 nigel 59 2. The Makefile had to be changed to make it work on BSD systems, where 'make'
2518     doesn't seem to recognize that ./xxx and xxx are the same file. (This entry
2519     isn't in ChangeLog distributed with 3.7 because I forgot when I hastily made
2520     this fix an hour or so after the initial 3.7 release.)
2521 nigel 57
2522 nigel 59
2523 nigel 55 Version 3.6 23-Oct-01
2524     ---------------------
2526     1. Crashed with /(sens|respons)e and \1ibility/ and "sense and sensibility" if
2527     offsets passed as NULL with zero offset count.
2529     2. The config.guess and config.sub files had not been updated when I moved to
2530     the latest autoconf.
2533 nigel 53 Version 3.5 15-Aug-01
2534     ---------------------
2535 nigel 5
2536 nigel 53 1. Added some missing #if !defined NOPOSIX conditionals in pcretest.c that
2537     had been forgotten.
2539     2. By using declared but undefined structures, we can avoid using "void"
2540     definitions in pcre.h while keeping the internal definitions of the structures
2541     private.
2543     3. The distribution is now built using autoconf 2.50 and libtool 1.4. From a
2544     user point of view, this means that both static and shared libraries are built
2545     by default, but this can be individually controlled. More of the work of
2546     handling this static/shared cases is now inside libtool instead of PCRE's make
2547     file.
2549     4. The pcretest utility is now installed along with pcregrep because it is
2550     useful for users (to test regexs) and by doing this, it automatically gets
2551     relinked by libtool. The documentation has been turned into a man page, so
2552     there are now .1, .txt, and .html versions in /doc.
2554     5. Upgrades to pcregrep:
2555     (i) Added long-form option names like gnu grep.
2556     (ii) Added --help to list all options with an explanatory phrase.
2557     (iii) Added -r, --recursive to recurse into sub-directories.
2558     (iv) Added -f, --file to read patterns from a file.
2560     6. pcre_exec() was referring to its "code" argument before testing that
2561     argument for NULL (and giving an error if it was NULL).
2563     7. Upgraded Makefile.in to allow for compiling in a different directory from
2564     the source directory.
2566     8. Tiny buglet in pcretest: when pcre_fullinfo() was called to retrieve the
2567     options bits, the pointer it was passed was to an int instead of to an unsigned
2568     long int. This mattered only on 64-bit systems.
2570     9. Fixed typo (3.4/1) in pcre.h again. Sigh. I had changed pcre.h (which is
2571     generated) instead of pcre.in, which it its source. Also made the same change
2572     in several of the .c files.
2574     10. A new release of gcc defines printf() as a macro, which broke pcretest
2575     because it had an ifdef in the middle of a string argument for printf(). Fixed
2576     by using separate calls to printf().
2578     11. Added --enable-newline-is-cr and --enable-newline-is-lf to the configure
2579     script, to force use of CR or LF instead of \n in the source. On non-Unix
2580     systems, the value can be set in config.h.
2582     12. The limit of 200 on non-capturing parentheses is a _nesting_ limit, not an
2583     absolute limit. Changed the text of the error message to make this clear, and
2584     likewise updated the man page.
2586     13. The limit of 99 on the number of capturing subpatterns has been removed.
2587     The new limit is 65535, which I hope will not be a "real" limit.
2590 nigel 51 Version 3.4 22-Aug-00
2591     ---------------------
2593     1. Fixed typo in pcre.h: unsigned const char * changed to const unsigned char *.
2595     2. Diagnose condition (?(0) as an error instead of crashing on matching.
2598 nigel 49 Version 3.3 01-Aug-00
2599     ---------------------
2601     1. If an octal character was given, but the value was greater than \377, it
2602     was not getting masked to the least significant bits, as documented. This could
2603     lead to crashes in some systems.
2605     2. Perl 5.6 (if not earlier versions) accepts classes like [a-\d] and treats
2606     the hyphen as a literal. PCRE used to give an error; it now behaves like Perl.
2608     3. Added the functions pcre_free_substring() and pcre_free_substring_list().
2609     These just pass their arguments on to (pcre_free)(), but they are provided
2610     because some uses of PCRE bind it to non-C systems that can call its functions,
2611     but cannot call free() or pcre_free() directly.
2613     4. Add "make test" as a synonym for "make check". Corrected some comments in
2614     the Makefile.
2616     5. Add $(DESTDIR)/ in front of all the paths in the "install" target in the
2617     Makefile.
2619     6. Changed the name of pgrep to pcregrep, because Solaris has introduced a
2620     command called pgrep for grepping around the active processes.
2622     7. Added the beginnings of support for UTF-8 character strings.
2624     8. Arranged for the Makefile to pass over the settings of CC, CFLAGS, and
2625     RANLIB to ./ltconfig so that they are used by libtool. I think these are all
2626     the relevant ones. (AR is not passed because ./ltconfig does its own figuring
2627     out for the ar command.)
2630 nigel 47 Version 3.2 12-May-00
2631     ---------------------
2633     This is purely a bug fixing release.
2635     1. If the pattern /((Z)+|A)*/ was matched agained ZABCDEFG it matched Z instead
2636     of ZA. This was just one example of several cases that could provoke this bug,
2637     which was introduced by change 9 of version 2.00. The code for breaking
2638     infinite loops after an iteration that matches an empty string was't working
2639     correctly.
2641     2. The pcretest program was not imitating Perl correctly for the pattern /a*/g
2642     when matched against abbab (for example). After matching an empty string, it
2643     wasn't forcing anchoring when setting PCRE_NOTEMPTY for the next attempt; this
2644     caused it to match further down the string than it should.
2646     3. The code contained an inclusion of sys/types.h. It isn't clear why this
2647     was there because it doesn't seem to be needed, and it causes trouble on some
2648     systems, as it is not a Standard C header. It has been removed.
2650     4. Made 4 silly changes to the source to avoid stupid compiler warnings that
2651     were reported on the Macintosh. The changes were from
2653     while ((c = *(++ptr)) != 0 && c != '\n');
2654     to
2655     while ((c = *(++ptr)) != 0 && c != '\n') ;
2657     Totally extraordinary, but if that's what it takes...
2659     5. PCRE is being used in one environment where neither memmove() nor bcopy() is
2660     available. Added HAVE_BCOPY and an autoconf test for it; if neither
2661     HAVE_MEMMOVE nor HAVE_BCOPY is set, use a built-in emulation function which
2662     assumes the way PCRE uses memmove() (always moving upwards).
2664     6. PCRE is being used in one environment where strchr() is not available. There
2665     was only one use in pcre.c, and writing it out to avoid strchr() probably gives
2666     faster code anyway.
2669 nigel 45 Version 3.1 09-Feb-00
2670     ---------------------
2672     The only change in this release is the fixing of some bugs in Makefile.in for
2673     the "install" target:
2675     (1) It was failing to install pcreposix.h.
2677     (2) It was overwriting the pcre.3 man page with the pcreposix.3 man page.
2680 nigel 43 Version 3.0 01-Feb-00
2681     ---------------------
2682 nigel 41
2683     1. Add support for the /+ modifier to perltest (to output $` like it does in
2684     pcretest).
2686     2. Add support for the /g modifier to perltest.
2688     3. Fix pcretest so that it behaves even more like Perl for /g when the pattern
2689     matches null strings.
2691     4. Fix perltest so that it doesn't do unwanted things when fed an empty
2692     pattern. Perl treats empty patterns specially - it reuses the most recent
2693     pattern, which is not what we want. Replace // by /(?#)/ in order to avoid this
2694     effect.
2696     5. The POSIX interface was broken in that it was just handing over the POSIX
2697     captured string vector to pcre_exec(), but (since release 2.00) PCRE has
2698     required a bigger vector, with some working space on the end. This means that
2699     the POSIX wrapper now has to get and free some memory, and copy the results.
2701 nigel 43 6. Added some simple autoconf support, placing the test data and the
2702     documentation in separate directories, re-organizing some of the
2703     information files, and making it build pcre-config (a GNU standard). Also added
2704     libtool support for building PCRE as a shared library, which is now the
2705     default.
2706 nigel 41
2707 nigel 43 7. Got rid of the leading zero in the definition of PCRE_MINOR because 08 and
2708     09 are not valid octal constants. Single digits will be used for minor values
2709     less than 10.
2711     8. Defined REG_EXTENDED and REG_NOSUB as zero in the POSIX header, so that
2712     existing programs that set these in the POSIX interface can use PCRE without
2713     modification.
2715     9. Added a new function, pcre_fullinfo() with an extensible interface. It can
2716     return all that pcre_info() returns, plus additional data. The pcre_info()
2717     function is retained for compatibility, but is considered to be obsolete.
2719     10. Added experimental recursion feature (?R) to handle one common case that
2720     Perl 5.6 will be able to do with (?p{...}).
2722     11. Added support for POSIX character classes like [:alpha:], which Perl is
2723     adopting.
2726 nigel 39 Version 2.08 31-Aug-99
2727     ----------------------
2729     1. When startoffset was not zero and the pattern began with ".*", PCRE was not
2730     trying to match at the startoffset position, but instead was moving forward to
2731     the next newline as if a previous match had failed.
2733     2. pcretest was not making use of PCRE_NOTEMPTY when repeating for /g and /G,
2734     and could get into a loop if a null string was matched other than at the start
2735     of the subject.
2737     3. Added definitions of PCRE_MAJOR and PCRE_MINOR to pcre.h so the version can
2738     be distinguished at compile time, and for completeness also added PCRE_DATE.
2740     5. Added Paul Sokolovsky's minor changes to make it easy to compile a Win32 DLL
2741     in GnuWin32 environments.
2744 nigel 37 Version 2.07 29-Jul-99
2745     ----------------------
2747     1. The documentation is now supplied in plain text form and HTML as well as in
2748     the form of man page sources.
2750     2. C++ compilers don't like assigning (void *) values to other pointer types.
2751     In particular this affects malloc(). Although there is no problem in Standard
2752     C, I've put in casts to keep C++ compilers happy.
2754     3. Typo on pcretest.c; a cast of (unsigned char *) in the POSIX regexec() call
2755     should be (const char *).
2757     4. If NOPOSIX is defined, pcretest.c compiles without POSIX support. This may
2758     be useful for non-Unix systems who don't want to bother with the POSIX stuff.
2759     However, I haven't made this a standard facility. The documentation doesn't
2760     mention it, and the Makefile doesn't support it.
2762     5. The Makefile now contains an "install" target, with editable destinations at
2763     the top of the file. The pcretest program is not installed.
2765     6. pgrep -V now gives the PCRE version number and date.
2767     7. Fixed bug: a zero repetition after a literal string (e.g. /abcde{0}/) was
2768     causing the entire string to be ignored, instead of just the last character.
2770     8. If a pattern like /"([^\\"]+|\\.)*"/ is applied in the normal way to a
2771     non-matching string, it can take a very, very long time, even for strings of
2772     quite modest length, because of the nested recursion. PCRE now does better in
2773     some of these cases. It does this by remembering the last required literal
2774     character in the pattern, and pre-searching the subject to ensure it is present
2775     before running the real match. In other words, it applies a heuristic to detect
2776     some types of certain failure quickly, and in the above example, if presented
2777     with a string that has no trailing " it gives "no match" very quickly.
2779     9. A new runtime option PCRE_NOTEMPTY causes null string matches to be ignored;
2780     other alternatives are tried instead.
2783 nigel 35 Version 2.06 09-Jun-99
2784     ----------------------
2786     1. Change pcretest's output for amount of store used to show just the code
2787     space, because the remainder (the data block) varies in size between 32-bit and
2788     64-bit systems.
2790     2. Added an extra argument to pcre_exec() to supply an offset in the subject to
2791     start matching at. This allows lookbehinds to work when searching for multiple
2792     occurrences in a string.
2794     3. Added additional options to pcretest for testing multiple occurrences:
2796     /+ outputs the rest of the string that follows a match
2797     /g loops for multiple occurrences, using the new startoffset argument
2798     /G loops for multiple occurrences by passing an incremented pointer
2800     4. PCRE wasn't doing the "first character" optimization for patterns starting
2801     with \b or \B, though it was doing it for other lookbehind assertions. That is,
2802     it wasn't noticing that a match for a pattern such as /\bxyz/ has to start with
2803     the letter 'x'. On long subject strings, this gives a significant speed-up.
2806 nigel 33 Version 2.05 21-Apr-99
2807     ----------------------
2809     1. Changed the type of magic_number from int to long int so that it works
2810     properly on 16-bit systems.
2812     2. Fixed a bug which caused patterns starting with .* not to work correctly
2813     when the subject string contained newline characters. PCRE was assuming
2814     anchoring for such patterns in all cases, which is not correct because .* will
2815     not pass a newline unless PCRE_DOTALL is set. It now assumes anchoring only if
2816     DOTALL is set at top level; otherwise it knows that patterns starting with .*
2817     must be retried after every newline in the subject.
2820 nigel 31 Version 2.04 18-Feb-99
2821     ----------------------
2823     1. For parenthesized subpatterns with repeats whose minimum was zero, the
2824     computation of the store needed to hold the pattern was incorrect (too large).
2825     If such patterns were nested a few deep, this could multiply and become a real
2826     problem.
2828     2. Added /M option to pcretest to show the memory requirement of a specific
2829     pattern. Made -m a synonym of -s (which does this globally) for compatibility.
2831     3. Subpatterns of the form (regex){n,m} (i.e. limited maximum) were being
2832     compiled in such a way that the backtracking after subsequent failure was
2833     pessimal. Something like (a){0,3} was compiled as (a)?(a)?(a)? instead of
2834     ((a)((a)(a)?)?)? with disastrous performance if the maximum was of any size.
2837 nigel 29 Version 2.03 02-Feb-99
2838     ----------------------
2840     1. Fixed typo and small mistake in man page.
2842 nigel 31 2. Added 4th condition (GPL supersedes if conflict) and created separate
2843     LICENCE file containing the conditions.
2844 nigel 29
2845     3. Updated pcretest so that patterns such as /abc\/def/ work like they do in
2846     Perl, that is the internal \ allows the delimiter to be included in the
2847     pattern. Locked out the use of \ as a delimiter. If \ immediately follows
2848     the final delimiter, add \ to the end of the pattern (to test the error).
2850     4. Added the convenience functions for extracting substrings after a successful
2851     match. Updated pcretest to make it able to test these functions.
2854 nigel 27 Version 2.02 14-Jan-99
2855     ----------------------
2857     1. Initialized the working variables associated with each extraction so that
2858     their saving and restoring doesn't refer to uninitialized store.
2860     2. Put dummy code into study.c in order to trick the optimizer of the IBM C
2861     compiler for OS/2 into generating correct code. Apparently IBM isn't going to
2862     fix the problem.
2864     3. Pcretest: the timing code wasn't using LOOPREPEAT for timing execution
2865     calls, and wasn't printing the correct value for compiling calls. Increased the
2866     default value of LOOPREPEAT, and the number of significant figures in the
2867     times.
2869     4. Changed "/bin/rm" in the Makefile to "-rm" so it works on Windows NT.
2871     5. Renamed "deftables" as "dftables" to get it down to 8 characters, to avoid
2872     a building problem on Windows NT with a FAT file system.
2875 nigel 25 Version 2.01 21-Oct-98
2876     ----------------------
2878     1. Changed the API for pcre_compile() to allow for the provision of a pointer
2879     to character tables built by pcre_maketables() in the current locale. If NULL
2880     is passed, the default tables are used.
2883 nigel 23 Version 2.00 24-Sep-98
2884 nigel 21 ----------------------
2886 nigel 23 1. Since the (>?) facility is in Perl 5.005, don't require PCRE_EXTRA to enable
2887     it any more.
2889     2. Allow quantification of (?>) groups, and make it work correctly.
2891     3. The first character computation wasn't working for (?>) groups.
2893     4. Correct the implementation of \Z (it is permitted to match on the \n at the
2894     end of the subject) and add 5.005's \z, which really does match only at the
2895     very end of the subject.
2897     5. Remove the \X "cut" facility; Perl doesn't have it, and (?> is neater.
2899     6. Remove the ability to specify CASELESS, MULTILINE, DOTALL, and
2900     DOLLAR_END_ONLY at runtime, to make it possible to implement the Perl 5.005
2901     localized options. All options to pcre_study() were also removed.
2903     7. Add other new features from 5.005:
2905     $(?<= positive lookbehind
2906     $(?<! negative lookbehind
2907     (?imsx-imsx) added the unsetting capability
2908     such a setting is global if at outer level; local otherwise
2909     (?imsx-imsx:) non-capturing groups with option setting
2910     (?(cond)re|re) conditional pattern matching
2912     A backreference to itself in a repeated group matches the previous
2913     captured string.
2915     8. General tidying up of studying (both automatic and via "study")
2916     consequential on the addition of new assertions.
2918     9. As in 5.005, unlimited repeated groups that could match an empty substring
2919     are no longer faulted at compile time. Instead, the loop is forcibly broken at
2920     runtime if any iteration does actually match an empty substring.
2922     10. Include the RunTest script in the distribution.
2924     11. Added tests from the Perl 5.005_02 distribution. This showed up a few
2925     discrepancies, some of which were old and were also with respect to 5.004. They
2926     have now been fixed.
2929     Version 1.09 28-Apr-98
2930     ----------------------
2932 nigel 21 1. A negated single character class followed by a quantifier with a minimum
2933     value of one (e.g. [^x]{1,6} ) was not compiled correctly. This could lead to
2934     program crashes, or just wrong answers. This did not apply to negated classes
2935     containing more than one character, or to minima other than one.
2938 nigel 19 Version 1.08 27-Mar-98
2939     ----------------------
2941     1. Add PCRE_UNGREEDY to invert the greediness of quantifiers.
2943     2. Add (?U) and (?X) to set PCRE_UNGREEDY and PCRE_EXTRA respectively. The
2944     latter must appear before anything that relies on it in the pattern.
2947 nigel 17 Version 1.07 16-Feb-98
2948     ----------------------
2950     1. A pattern such as /((a)*)*/ was not being diagnosed as in error (unlimited
2951     repeat of a potentially empty string).
2954 nigel 15 Version 1.06 23-Jan-98
2955     ----------------------
2957     1. Added Markus Oberhumer's little patches for C++.
2959     2. Literal strings longer than 255 characters were broken.
2962 nigel 13 Version 1.05 23-Dec-97
2963     ----------------------
2965     1. Negated character classes containing more than one character were failing if
2966     PCRE_CASELESS was set at run time.
2969 nigel 11 Version 1.04 19-Dec-97
2970     ----------------------
2972     1. Corrected the man page, where some "const" qualifiers had been omitted.
2974     2. Made debugging output print "{0,xxx}" instead of just "{,xxx}" to agree with
2975     input syntax.
2977     3. Fixed memory leak which occurred when a regex with back references was
2978     matched with an offsets vector that wasn't big enough. The temporary memory
2979     that is used in this case wasn't being freed if the match failed.
2981     4. Tidied pcretest to ensure it frees memory that it gets.
2983     5. Temporary memory was being obtained in the case where the passed offsets
2984     vector was exactly big enough.
2986     6. Corrected definition of offsetof() from change 5 below.
2988     7. I had screwed up change 6 below and broken the rules for the use of
2989     setjmp(). Now fixed.
2992 nigel 9 Version 1.03 18-Dec-97
2993     ----------------------
2995     1. A erroneous regex with a missing opening parenthesis was correctly
2996     diagnosed, but PCRE attempted to access brastack[-1], which could cause crashes
2997     on some systems.
2999     2. Replaced offsetof(real_pcre, code) by offsetof(real_pcre, code[0]) because
3000     it was reported that one broken compiler failed on the former because "code" is
3001     also an independent variable.
3003     3. The erroneous regex a[]b caused an array overrun reference.
3005     4. A regex ending with a one-character negative class (e.g. /[^k]$/) did not
3006     fail on data ending with that character. (It was going on too far, and checking
3007     the next character, typically a binary zero.) This was specific to the
3008     optimized code for single-character negative classes.
3010     5. Added a contributed patch from the TIN world which does the following:
3012     + Add an undef for memmove, in case the the system defines a macro for it.
3014     + Add a definition of offsetof(), in case there isn't one. (I don't know
3015     the reason behind this - offsetof() is part of the ANSI standard - but
3016     it does no harm).
3018     + Reduce the ifdef's in pcre.c using macro DPRINTF, thereby eliminating
3019     most of the places where whitespace preceded '#'. I have given up and
3020     allowed the remaining 2 cases to be at the margin.
3022     + Rename some variables in pcre to eliminate shadowing. This seems very
3023     pedantic, but does no harm, of course.
3025     6. Moved the call to setjmp() into its own function, to get rid of warnings
3026     from gcc -Wall, and avoided calling it at all unless PCRE_EXTRA is used.
3028     7. Constructs such as \d{8,} were compiling into the equivalent of
3029 nigel 11 \d{8}\d{0,65527} instead of \d{8}\d* which didn't make much difference to the
3030 nigel 9 outcome, but in this particular case used more store than had been allocated,
3031     which caused the bug to be discovered because it threw up an internal error.
3033     8. The debugging code in both pcre and pcretest for outputting the compiled
3034     form of a regex was going wrong in the case of back references followed by
3035     curly-bracketed repeats.
3038 nigel 7 Version 1.02 12-Dec-97
3039     ----------------------
3041     1. Typos in pcre.3 and comments in the source fixed.
3043     2. Applied a contributed patch to get rid of places where it used to remove
3044     'const' from variables, and fixed some signed/unsigned and uninitialized
3045     variable warnings.
3047     3. Added the "runtest" target to Makefile.
3049     4. Set default compiler flag to -O2 rather than just -O.
3052 nigel 5 Version 1.01 19-Nov-97
3053     ----------------------
3055     1. PCRE was failing to diagnose unlimited repeat of empty string for patterns
3056     like /([ab]*)*/, that is, for classes with more than one character in them.
3058     2. Likewise, it wasn't diagnosing patterns with "once-only" subpatterns, such
3059     as /((?>a*))*/ (a PCRE_EXTRA facility).
3062     Version 1.00 18-Nov-97
3063     ----------------------
3065     1. Added compile-time macros to support systems such as SunOS4 which don't have
3066     memmove() or strerror() but have other things that can be used instead.
3068     2. Arranged that "make clean" removes the executables.
3071 nigel 3 Version 0.99 27-Oct-97
3072     ----------------------
3074     1. Fixed bug in code for optimizing classes with only one character. It was
3075     initializing a 32-byte map regardless, which could cause it to run off the end
3076     of the memory it had got.
3078     2. Added, conditional on PCRE_EXTRA, the proposed (?>REGEX) construction.
3081     Version 0.98 22-Oct-97
3082     ----------------------
3084     1. Fixed bug in code for handling temporary memory usage when there are more
3085     back references than supplied space in the ovector. This could cause segfaults.
3088     Version 0.97 21-Oct-97
3089     ----------------------
3091     1. Added the \X "cut" facility, conditional on PCRE_EXTRA.
3093     2. Optimized negated single characters not to use a bit map.
3095     3. Brought error texts together as macro definitions; clarified some of them;
3096     fixed one that was wrong - it said "range out of order" when it meant "invalid
3097     escape sequence".
3099     4. Changed some char * arguments to const char *.
3101     5. Added PCRE_NOTBOL and PCRE_NOTEOL (from POSIX).
3103     6. Added the POSIX-style API wrapper in pcreposix.a and testing facilities in
3104     pcretest.
3107     Version 0.96 16-Oct-97
3108     ----------------------
3110     1. Added a simple "pgrep" utility to the distribution.
3112     2. Fixed an incompatibility with Perl: "{" is now treated as a normal character
3113     unless it appears in one of the precise forms "{ddd}", "{ddd,}", or "{ddd,ddd}"
3114     where "ddd" means "one or more decimal digits".
3116     3. Fixed serious bug. If a pattern had a back reference, but the call to
3117     pcre_exec() didn't supply a large enough ovector to record the related
3118     identifying subpattern, the match always failed. PCRE now remembers the number
3119     of the largest back reference, and gets some temporary memory in which to save
3120     the offsets during matching if necessary, in order to ensure that
3121     backreferences always work.
3123     4. Increased the compatibility with Perl in a number of ways:
3125     (a) . no longer matches \n by default; an option PCRE_DOTALL is provided
3126     to request this handling. The option can be set at compile or exec time.
3128     (b) $ matches before a terminating newline by default; an option
3129     PCRE_DOLLAR_ENDONLY is provided to override this (but not in multiline
3130     mode). The option can be set at compile or exec time.
3132     (c) The handling of \ followed by a digit other than 0 is now supposed to be
3133     the same as Perl's. If the decimal number it represents is less than 10
3134     or there aren't that many previous left capturing parentheses, an octal
3135     escape is read. Inside a character class, it's always an octal escape,
3136     even if it is a single digit.
3138     (d) An escaped but undefined alphabetic character is taken as a literal,
3139     unless PCRE_EXTRA is set. Currently this just reserves the remaining
3140     escapes.
3142     (e) {0} is now permitted. (The previous item is removed from the compiled
3143     pattern).
3145     5. Changed all the names of code files so that the basic parts are no longer
3146     than 10 characters, and abolished the teeny "globals.c" file.
3148     6. Changed the handling of character classes; they are now done with a 32-byte
3149     bit map always.
3151     7. Added the -d and /D options to pcretest to make it possible to look at the
3152     internals of compilation without having to recompile pcre.
3155     Version 0.95 23-Sep-97
3156     ----------------------
3158     1. Fixed bug in pre-pass concerning escaped "normal" characters such as \x5c or
3159     \x20 at the start of a run of normal characters. These were being treated as
3160     real characters, instead of the source characters being re-checked.
3163     Version 0.94 18-Sep-97
3164     ----------------------
3166     1. The functions are now thread-safe, with the caveat that the global variables
3167     containing pointers to malloc() and free() or alternative functions are the
3168     same for all threads.
3170     2. Get pcre_study() to generate a bitmap of initial characters for non-
3171     anchored patterns when this is possible, and use it if passed to pcre_exec().
3174     Version 0.93 15-Sep-97
3175     ----------------------
3177     1. /(b)|(:+)/ was computing an incorrect first character.
3179     2. Add pcre_study() to the API and the passing of pcre_extra to pcre_exec(),
3180     but not actually doing anything yet.
3182     3. Treat "-" characters in classes that cannot be part of ranges as literals,
3183     as Perl does (e.g. [-az] or [az-]).
3185     4. Set the anchored flag if a branch starts with .* or .*? because that tests
3186     all possible positions.
3188     5. Split up into different modules to avoid including unneeded functions in a
3189     compiled binary. However, compile and exec are still in one module. The "study"
3190     function is split off.
3192     6. The character tables are now in a separate module whose source is generated
3193     by an auxiliary program - but can then be edited by hand if required. There are
3194     now no calls to isalnum(), isspace(), isdigit(), isxdigit(), tolower() or
3195     toupper() in the code.
3197     7. Turn the malloc/free funtions variables into pcre_malloc and pcre_free and
3198     make them global. Abolish the function for setting them, as the caller can now
3199     set them directly.
3202     Version 0.92 11-Sep-97
3203     ----------------------
3205     1. A repeat with a fixed maximum and a minimum of 1 for an ordinary character
3206     (e.g. /a{1,3}/) was broken (I mis-optimized it).
3208     2. Caseless matching was not working in character classes if the characters in
3209     the pattern were in upper case.
3211     3. Make ranges like [W-c] work in the same way as Perl for caseless matching.
3213     4. Make PCRE_ANCHORED public and accept as a compile option.
3215     5. Add an options word to pcre_exec() and accept PCRE_ANCHORED and
3216     PCRE_CASELESS at run time. Add escapes \A and \I to pcretest to cause it to
3217     pass them.
3219     6. Give an error if bad option bits passed at compile or run time.
3221     7. Add PCRE_MULTILINE at compile and exec time, and (?m) as well. Add \M to
3222     pcretest to cause it to pass that flag.
3224     8. Add pcre_info(), to get the number of identifying subpatterns, the stored
3225     options, and the first character, if set.
3227     9. Recognize C+ or C{n,m} where n >= 1 as providing a fixed starting character.
3230     Version 0.91 10-Sep-97
3231     ----------------------
3233     1. PCRE was failing to diagnose unlimited repeats of subpatterns that could
3234     match the empty string as in /(a*)*/. It was looping and ultimately crashing.
3236     2. PCRE was looping on encountering an indefinitely repeated back reference to
3237     a subpattern that had matched an empty string, e.g. /(a|)\1*/. It now does what
3238     Perl does - treats the match as successful.
3240     ****


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